Micro-mesh fabric pollination bags for switchgrass

Science.gov (United States)

Pollination bags for making controlled crosses between switchgrass plants were made from a polyester micro-mesh fabric with a mesh size of 41 µm which is smaller than the mean reported 43 µm diameter of switchgrass pollen. When used in paired plant crosses between switchgrass plants, the mean amoun...

Hybridization of downregulated-COMT transgenic switchgrass lines with field selected switchgrass for improved biomass traits

Science.gov (United States)

Transgenic switchgrass (Panicum virgatum L.) has been produced for improved cell walls for biofuels. Downregulated caffeic acid 3-O-methyltransferase (COMT) switchgrass produced significantly more biomass and biofuel than the non-transgenic progenitor line. In the present study we sought to further...

Accuracy of Genomic Prediction in Switchgrass (Panicum virgatum L. Improved by Accounting for Linkage Disequilibrium

Directory of Open Access Journals (Sweden)

Guillaume P. Ramstein

2016-04-01

Full Text Available Switchgrass is a relatively high-yielding and environmentally sustainable biomass crop, but further genetic gains in biomass yield must be achieved to make it an economically viable bioenergy feedstock. Genomic selection (GS is an attractive technology to generate rapid genetic gains in switchgrass, and meet the goals of a substantial displacement of petroleum use with biofuels in the near future. In this study, we empirically assessed prediction procedures for genomic selection in two different populations, consisting of 137 and 110 half-sib families of switchgrass, tested in two locations in the United States for three agronomic traits: dry matter yield, plant height, and heading date. Marker data were produced for the families’ parents by exome capture sequencing, generating up to 141,030 polymorphic markers with available genomic-location and annotation information. We evaluated prediction procedures that varied not only by learning schemes and prediction models, but also by the way the data were preprocessed to account for redundancy in marker information. More complex genomic prediction procedures were generally not significantly more accurate than the simplest procedure, likely due to limited population sizes. Nevertheless, a highly significant gain in prediction accuracy was achieved by transforming the marker data through a marker correlation matrix. Our results suggest that marker-data transformations and, more generally, the account of linkage disequilibrium among markers, offer valuable opportunities for improving prediction procedures in GS. Some of the achieved prediction accuracies should motivate implementation of GS in switchgrass breeding programs.

Evaluating the Potential of Marginal Land for Cellulosic Feedstock Production and Carbon Sequestration in the United States.

Science.gov (United States)

Emery, Isaac; Mueller, Steffen; Qin, Zhangcai; Dunn, Jennifer B

2017-01-03

Land availability for growing feedstocks at scale is a crucial concern for the bioenergy industry. Feedstock production on land not well-suited to growing conventional crops, or marginal land, is often promoted as ideal, although there is a poor understanding of the qualities, quantity, and distribution of marginal lands in the United States. We examine the spatial distribution of land complying with several key marginal land definitions at the United States county, agro-ecological zone, and national scales, and compare the ability of both marginal land and land cover data sets to identify regions for feedstock production. We conclude that very few land parcels comply with multiple definitions of marginal land. Furthermore, to examine possible carbon-flow implications of feedstock production on land that could be considered marginal per multiple definitions, we model soil carbon changes upon transitions from marginal cropland, grassland, and cropland-pastureland to switchgrass production for three marginal land-rich counties. Our findings suggest that total soil organic carbon changes per county are small, and generally positive, and can influence life-cycle greenhouse gas emissions of switchgrass ethanol.

Biofuel, land and water: maize, switchgrass or Miscanthus?

International Nuclear Information System (INIS)

Zhuang Qianlai; Qin Zhangcai; Chen Min

2013-01-01

The productive cellulosic crops switchgrass and Miscanthus are considered as viable biofuel sources. To meet the 2022 national biofuel target mandate, actions must be taken, e.g., maize cultivation must be intensified and expanded, and other biofuel crops (switchgrass and Miscanthus) must be cultivated. This raises questions on the use efficiencies of land and water; to date, the demand on these resources to meet the national biofuel target has rarely been analyzed. Here, we present a data-model assimilation analysis, assuming that maize, switchgrass and Miscanthus will be grown on currently available croplands in the US. Model simulations suggest that maize can produce 3.0–5.4 kiloliters (kl) of ethanol for every hectare of land, depending on the feedstock to ethanol conversion efficiency; Miscanthus has more than twice the biofuel production capacity relative to maize, and switchgrass is the least productive of the three potential sources of ethanol. To meet the biofuel target, about 26.5 million hectares of land and over 90 km 3 of water (of evapotranspiration) are needed if maize grain alone is used. If Miscanthus was substituted for maize, the process would save half of the land and one third of the water. With more advanced biofuel conversion technology for Miscanthus, only nine million hectares of land and 45 km 3 of water would probably meet the national target. Miscanthus could be a good alternative biofuel crop to maize due to its significantly lower demand for land and water on a per unit of ethanol basis. (letter)

Evaluation of Switchgrass as a co-firing fuel in the Southeast

Energy Technology Data Exchange (ETDEWEB)

Southern Research Institute

2001-11-01

The ''Evaluation of Switchgrass as a Co-Firing Fuel in the Southeast'' is a comprehensive project incorporating the highest yielding variety of switchgrass, unique harvesting methods, detailed parametric evaluations in a state-of-the-art combustion research facility, and a full-scale demonstration in a tangentially-fired Alabama Power Company power boiler. These features were incorporated into the project to reduce the technical and economic risk of yielding a practical renewable energy option for the southeastern US. There are particular incentives for proving the feasibility of switchgrass as a biomass fuel in the southeastern US. Even though agriculture is a predominant industry much of the land in this region is under-utilized, marginal farmland. As a result, some of the poorest counties in the nation are located in this region. The yields of switchgrass are substantially higher in the southeastern US than in other regions. Yield, or productivity, is a critical factor in determining the feasibility of biomass fuel. Yields in small research plots in the region averaged 25.8 Mg/ha (11.5 tons/acre) over the period 1990-1994. Achievable commercial yield in the southeastern US will likely be about 15.7 Mg/ha (7 tons/acre) with currently available varieties. Use of switchgrass as a supplemental fuel for coal-fired utility boilers could create an enormous market for growers. The Southern Company has 23,000 MW of coal-fired capacity in the southeast. If only 1% of this capacity was provided by switchgrass instead of coal, 74,500 ha (184,000 acres) of production would be needed. This would generate 1,288,000 tons of switchgrass which, if valued at $35/ton, would amount to over $45 million.

Microwave pretreatment of switchgrass for bioethanol production

Science.gov (United States)

Keshwani, Deepak Radhakrishin

Lignocellulosic materials are promising alternative feedstocks for bioethanol production. These materials include agricultural residues, cellulosic waste such as newsprint and office paper, logging residues, and herbaceous and woody crops. However, the recalcitrant nature of lignocellulosic biomass necessitates a pretreatment step to improve the yield of fermentable sugars. The overall goal of this dissertation is to expand the current state of knowledge on microwave-based pretreatment of lignocellulosic biomass. Existing research on bioenergy and value-added applications of switchgrass is reviewed in Chapter 2. Switchgrass is an herbaceous energy crop native to North America and has high biomass productivity, potentially low requirements for agricultural inputs and positive environmental impacts. Based on results from test plots, yields in excess of 20 Mg/ha have been reported. Environmental benefits associated with switchgrass include the potential for carbon sequestration, nutrient recovery from run-off, soil remediation and provision of habitats for grassland birds. Published research on pretreatment of switchgrass reported glucose yields ranging from 70-90% and xylose yields ranging from 70-100% after hydrolysis and ethanol yields ranging from 72-92% after fermentation. Other potential value-added uses of switchgrass include gasification, bio-oil production, newsprint production and fiber reinforcement in thermoplastic composites. Research on microwave-based pretreatment of switchgrass and coastal bermudagrass is presented in Chapter 3. Pretreatments were carried out by immersing the biomass in dilute chemical reagents and exposing the slurry to microwave radiation at 250 watts for residence times ranging from 5 to 20 minutes. Preliminary experiments identified alkalis as suitable chemical reagents for microwave-based pretreatment. An evaluation of different alkalis identified sodium hydroxide as the most effective alkali reagent. Under optimum pretreatment

Production of polyhydroxybutyrate in switchgrass

Energy Technology Data Exchange (ETDEWEB)

Somleva, Mariya N.; Snell, Kristi D.; Beaulieu, Julie; Peoples, Oliver P.; Garrison, Bradley; Patterson, Nii

2013-07-16

Transgenic plants, plant material, and plant cells for synthesis of polyhydroxyalkanoates, preferably poly(3-hydroxybutyrate) (also referred to a as PHB) are provided. Preferred plants that can be genetically engineered to produce PHB include plants that do not normally produce storage products such as oils and carbohydrates, and plants that have a C.sub.4 NAD-malic enzyme photosynthetic pathway. Such plants also advantageously produce lignocellulosic biomass that can be converted into biofuels. An exemplary plant that can be genetically engineered to produce PHB and produce lignocellulosic biomass is switchgrass, Panicum virgatum L. A preferred cultivar of switchgrass is Alamo. Other suitable cultivars of switchgrass include but are not limited to Blackwell, Kanlow, Nebraska 28, Pathfinder, Cave-in-Rock, Shelter and Trailblazer.

Structural Characterization of Lignin in Wild-Type versus COMT Down-Regulated Switchgrass

Energy Technology Data Exchange (ETDEWEB)

Samuel, Reichel [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA (United States); BioEnergy Science Center, Oak Ridge, TN (United States); Pu, Yunqiao, E-mail: yunqiao.pu@ipst.gatech.edu [BioEnergy Science Center, Oak Ridge, TN (United States); Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA (United States); Jiang, Nan [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA (United States); BioEnergy Science Center, Oak Ridge, TN (United States); Fu, Chunxiang [Forage Improvement Division, The Samuel Roberts Noble Foundation, Ardmore, OK (United States); Wang, Zeng-Yu [BioEnergy Science Center, Oak Ridge, TN (United States); Forage Improvement Division, The Samuel Roberts Noble Foundation, Ardmore, OK (United States); Ragauskas, Arthur, E-mail: yunqiao.pu@ipst.gatech.edu [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA (United States); BioEnergy Science Center, Oak Ridge, TN (United States)

2014-01-20

This study examined the chemical structural characteristics of cellulolytic enzyme lignin isolated from switchgrass focusing on comparisons between wild-type control and caffeic acid 3-O-methyltransferase (COMT) down-regulated transgenic line. Nuclear magnetic resonance techniques including {sup 13}C, {sup 31}P, and two-dimensional {sup 13}C-{sup 1}H heteronuclear single quantum coherence as well as gel permeation chromatography were employed. Compared to the wild-type, the COMT down-regulated transgenic switchgrass lignin demonstrated a decrease in syringyl (S):guaiacyl (G) ratio and p-coumarate:ferulate ratio, an increase in relative abundance of phenylcoumaran unit, and a comparable content of total free phenolic OH groups along with formation of benzodioxane unit. In addition, COMT down-regulation had no significant effects on the lignin molecular weights during its biosynthesis process.

ESTABLISHMENT AND EVALUATION OF SWITCHGRASS ON RECLAIMED MINE SOIL [English

Energy Technology Data Exchange (ETDEWEB)

Lang, David; Shankle, Brandon; Oswalt, Ernest; Duckworth, Jeremy; Sanborn, Judd; Buell, Rebecca; Roberson, Bill

2010-06-30

Switchgrass (Panicum virgatum L.) is a native warm season perennial grass that has productive potential of up to 20 Mg ha-1 of biomass and it persists for decades when harvested once per year. Switchgrass provides excellent ground cover and soil stabilization once established and contributes to soil sequestration of new carbon. Slow establishment on newly reclaimed soil, however, provides for significant erosive opportunities thereby requiring initial soil stabilization with a cover crop. Several planting options were evaluated on two topsoil substitute soils. The planting options included: 1) an existing stand of bermudagrass (Cynodon dactylon L.) that was killed with glyphosate followed by disking in red oxidized topsoil substitute and prime farmland topsoil respread in 2007, 2) red oxidized topsoil substitute was seeded directly with switchgrass, 3) browntop millet (Panicum ramosum) was established with switchgrass, 4) or switchgrass was established in senescing browntop millet or wheat without tillage. Switchgrass was successfully established into a bermudagrass sod that had been killed with herbicides and disked as well as into a senescing stand of browntop millet or wheat. Significant soil erosion occurred on the disked area in 2008 leading to considerable repair work followed by planting wheat. Disked areas that did not erode had an excellent stand of switchgrass with 23.3 plants m-2 in November, 2008. Eroded areas replanted in April, 2009 into senescing wheat had 46 plants m-2 by July, 2009. The area planted directly into newly respread soil in May, 2009 was eroded severely by a 75 mm thunderstorm and was repaired, disked and replanted to switchgrass and browntop millet. Switchgrass seeded with browntop millet had a sparse switchgrass stand and was replanted to switchgrass in August, 2009. Rainfall volumes from August, 2009 to October, 2009 totaled 750 mm, but new erosion damage in areas successfully planted to switchgrass has been minimal.

Seasonality and Management Affect Land Surface Temperature Differences Between Loblolly Pine and Switchgrass Ecosystems in Central Virginia

Science.gov (United States)

Ahlswede, B.; Thomas, R. Q.; O'Halloran, T. L.; Rady, J.; LeMoine, J.

2017-12-01

Changes in land-use and land management can have biogeochemical and biophysical effects on local and global climate. While managed ecosystems provide known food and fiber benefits, their influence on climate is less well quantified. In the southeastern United States, there are numerous types of intensely managed ecosystems but pine plantations and switchgrass fields represent two biogeochemical and biophysical extremes; a tall, low albedo forest with trees harvested after multiple decades vs. a short, higher albedo C4 grass field that is harvested annually. Despite the wide spread use of these ecosystems for timber and bioenergy, a quantitative, empirical evaluation of the net influence of these ecosystems on climate is lacking because it requires measuring both the greenhouse gas and energy balance of the ecosystems while controlling for the background weather and soil environment. To address this need, we established a pair of eddy flux towers in these ecosystems that are co-located (1.5 km apart) in Central Virginia and measured the radiative energy, non-radiative energy and carbon fluxes, along with associated biometeorology variables; the paired site has run since April 2016. During the first 1.5 years (two growing seasons), we found strong seasonality in the difference in surface temperature between the two ecosystems. In the growing seasons, both sites had similar surface temperature despite higher net radiation in pine. Following harvest of the switchgrass in September, the switchgrass temperatures increased relative to pine. In the winter, the pine ecosystem was warmer. We evaluate the drivers of these intra-annual dynamics and compare the climate influence of these biophysical differences to the differences in carbon fluxes between the sites using a suite of established climate regulation services metrics. Overall, our results show tradeoffs exist between the biogeochemical and biophysical climate services in managed ecosystems in the southeastern United

A Probabilistic Analysis of the Switchgrass Ethanol Cycle

Directory of Open Access Journals (Sweden)

Tadeusz W. Patzek

2010-09-01

Full Text Available The switchgrass-driven process for producing ethanol has received much popular attention. However, a realistic analysis of this process indicates three serious limitations: (a If switchgrass planted on 140 million hectares (the entire area of active U.S. cropland were used as feedstock and energy source for ethanol production, the net ethanol yield would replace on average about 20% of today’s gasoline consumption in the U.S. (b Because nonrenewable resources are required to produce ethanol from switchgrass, the incremental gas emissions would be on average 55 million tons of equivalent carbon dioxide per year to replace just 10% of U.S. automotive gasoline. (c In terms of delivering electrical or mechanical power, ethanol from 1 hectare (10,000 m2 of switchgrass is equivalent, on average, to 30 m2 of low-efficiency photovoltaic cells. This analysis suggests that investing toward more efficient and durable solar cells, and batteries, may be more promising than investing in a process to convert switchgrass to ethanol.

Switchgrass a valuable biomass crop for energy

CERN Document Server

2012-01-01

The demand of renewable energies is growing steadily both from policy and from industry which seeks environmentally friendly feed stocks. The recent policies enacted by the EU, USA and other industrialized countries foresee an increased interest in the cultivation of energy crops; there is clear evidence that switchgrass is one of the most promising biomass crop for energy production and bio-based economy and compounds. Switchgrass: A Valuable Biomass Crop for Energy provides a comprehensive guide to  switchgrass in terms of agricultural practices, potential use and markets, and environmental and social benefits. Considering this potential energy source from its biology, breed and crop physiology to its growth and management to the economical, social and environmental impacts, Switchgrass: A Valuable Biomass Crop for Energy brings together chapters from a range of experts in the field, including a foreword from Kenneth P. Vogel, to collect and present the environmental benefits and characteristics of this a ...

Sustainable Production of Switchgrass for Biomass Energy

Science.gov (United States)

Switchgrass (Panicum virgatum L.) is a C4 grass native to the North American tallgrass prairies, which historically extended from Mexico to Canada. It is the model perennial warm-season grass for biomass energy. USDA-ARS in Lincoln, NE has studied switchgrass continuously since 1936. Plot-scale rese...

Economic and Environmental Assessment of Switchgrass Production on High-Fertility Soil and an Assessment of Anaerobic Digests as an Intermediate Market for Switchgrass

Energy Technology Data Exchange (ETDEWEB)

Rhykerd, Robert [Illinois State Univ., Normal, IL (United States); Bierma, Thomas [Illinois State Univ., Normal, IL (United States); Jin, Guang [Illinois State Univ., Normal, IL (United States); Walker, Paul [Illinois State Univ., Normal, IL (United States)

2014-03-31

This project had two parts. Part 1 was an economic and environmental assessment of switchgrass production on high-fertility soil, and included an assessment of the effects of field irrigation with treated municipal wastewater (Studies A,C, and E in Final Agreement). Part 2 was an assessment of methods to enhance anaerobic digestion of switchgrass, and included evaluation of several other potential biomass feedstocks (Studies B and D in Final Agreement). Results from Part 1 demonstrated that switchgrass does not compete economically against a corn and soybean rotation on highly productive soils. All four varieties of switchgrass lost money while corn and soybeans were profitable in all four years of this study. Breakeven prices for the four switchgrass varieties were calculated using production costs. The installation of a center pivot irrigation system had minimal impact on crop production and corn and soybean production remained profitable in the year the irrigator was installed. Because of drought and delays in installing the wastewater treatment plant, the irrigation system was not used until year 4 of this study. Therefore, longer term studies evaluating multiple year studies on the impact of irrigation on switchgrass are warranted. Results from irrigating with treated municipal wastewater showed no negative impact on soil quality. Results from Part 2 demonstrated that anaerobic digestion (AD) of switchgrass could be significantly enhanced using low heat (100oC) and mild caustic pretreatment without fine-grinding. Heat for pretreatment could be available from biogas-based combined heat and power (CHP) systems. In bench-top digesters simulating municipal wastewater treatment AD, methane production of coarse-ground switchgrass increased over 20-fold with pretreatment compared to untreated switchgrass. Bench-top studies simulating dairy-based AD also found high specific methane yield, but even untreated switchgrass digested reasonably well, indicating the value of

Production and supply logistics of switchgrass as an energy feedstock

Science.gov (United States)

Switchgrass (Panicum virgatum L.) is a warm-season (C4), perennial grass that is native to the tallgrass ecoregion of North America (Figure 1). Historically, switchgrass has been used for summer forage, hay, ensiling, or in conservation plantings. At the end of the 20th century, switchgrass was de...

Non-targeted Colonization by the Endomycorrhizal Fungus, Serendipita vermifera, in Three Weeds Typically Co-occurring with Switchgrass

Directory of Open Access Journals (Sweden)

Prasun Ray

2018-01-01

Full Text Available Serendipita vermifera (=Sebacina vermifera; isolate MAFF305830 is a mycorrhizal fungus originally isolated from the roots of an Australian orchid that we have previously shown to be beneficial in enhancing biomass yield and drought tolerance in switchgrass, an important bioenergy crop for cellulosic ethanol production in the United States. However, almost nothing is known about how this root-associated fungus proliferates and grows through the soil matrix. Such information is critical to evaluate the possibility of non-target effects, such as unintended spread to weedy plants growing near a colonized switchgrass plant in a field environment. A microcosm experiment was conducted to study movement of vegetative mycelia of S. vermifera between intentionally inoculated switchgrass (Panicum virgatum L. and nearby weeds. We constructed size-exclusion microcosms to test three different common weeds, large crabgrass (Digitaria sanguinalis L., Texas panicum (Panicum texanum L., and Broadleaf signalgrass (Brachiaria platyphylla L., all species that typically co-occur in Southern Oklahoma and potentially compete with switchgrass. We report that such colonization of non-target plants by S. vermifera can indeed occur, seemingly via co-mingled root systems. As a consequence of colonization, significant enhancement of growth was noted in signalgrass, while a mild increase (albeit not significant was evident in crabgrass. Migration of the fungus seems unlikely in root-free bulk soil, as we failed to see transmission when the roots were kept separate. This research is the first documentation of non-targeted colonization of this unique root symbiotic fungus and highlights the need for such assessments prior to deployment of biological organisms in the field.

Switchgrass growth and pine–switchgrass interactions in established intercropping systems

Czech Academy of Sciences Publication Activity Database

Tian, S.; Cacho, J. F.; Youssef, M. A.; Chescheir, G. M.; Fischer, Milan; Nettles, J. E.; King, J. S.

2017-01-01

Roč. 9, č. 5 (2017), s. 845-857 ISSN 1757-1693 Institutional support: RVO:67179843 Keywords : agroforestry * competition * grass growth * interspecific interactions * loblolly pine * switchgrass Subject RIV: GC - Agronomy OBOR OECD: Agronomy, plant breeding and plant protection Impact factor: 4.655, year: 2016

Transmission of Switchgrass mosaic virus by Graminella aureovitatta

Science.gov (United States)

Switchgrass mosaic virus (SwMV) was identified in switchgrass (Panicum virgatum) and was proposed as a new marafivirus based on its genome sequence and comparison with its closest relative, Maize rayado fino virus (MRFV), a type member of the genus, Marafivirus. MRFV only infects maize (Zea mays) an...

The WRKY transcription factor family and senescence in switchgrass.

Science.gov (United States)

Rinerson, Charles I; Scully, Erin D; Palmer, Nathan A; Donze-Reiner, Teresa; Rabara, Roel C; Tripathi, Prateek; Shen, Qingxi J; Sattler, Scott E; Rohila, Jai S; Sarath, Gautam; Rushton, Paul J

2015-11-09

Early aerial senescence in switchgrass (Panicum virgatum) can significantly limit biomass yields. WRKY transcription factors that can regulate senescence could be used to reprogram senescence and enhance biomass yields. All potential WRKY genes present in the version 1.0 of the switchgrass genome were identified and curated using manual and bioinformatic methods. Expression profiles of WRKY genes in switchgrass flag leaf RNA-Seq datasets were analyzed using clustering and network analyses tools to identify both WRKY and WRKY-associated gene co-expression networks during leaf development and senescence onset. We identified 240 switchgrass WRKY genes including members of the RW5 and RW6 families of resistance proteins. Weighted gene co-expression network analysis of the flag leaf transcriptomes across development readily separated clusters of co-expressed genes into thirteen modules. A visualization highlighted separation of modules associated with the early and senescence-onset phases of flag leaf growth. The senescence-associated module contained 3000 genes including 23 WRKYs. Putative promoter regions of senescence-associated WRKY genes contained several cis-element-like sequences suggestive of responsiveness to both senescence and stress signaling pathways. A phylogenetic comparison of senescence-associated WRKY genes from switchgrass flag leaf with senescence-associated WRKY genes from other plants revealed notable hotspots in Group I, IIb, and IIe of the phylogenetic tree. We have identified and named 240 WRKY genes in the switchgrass genome. Twenty three of these genes show elevated mRNA levels during the onset of flag leaf senescence. Eleven of the WRKY genes were found in hotspots of related senescence-associated genes from multiple species and thus represent promising targets for future switchgrass genetic improvement. Overall, individual WRKY gene expression profiles could be readily linked to developmental stages of flag leaves.

Mapping grasslands suitable for cellulosic biofuels in the Greater Platte River Basin, United States

Science.gov (United States)

Wylie, Bruce K.; Gu, Yingxin

2012-01-01

Biofuels are an important component in the development of alternative energy supplies, which is needed to achieve national energy independence and security in the United States. The most common biofuel product today in the United States is corn-based ethanol; however, its development is limited because of concerns about global food shortages, livestock and food price increases, and water demand increases for irrigation and ethanol production. Corn-based ethanol also potentially contributes to soil erosion, and pesticides and fertilizers affect water quality. Studies indicate that future potential production of cellulosic ethanol is likely to be much greater than grain- or starch-based ethanol. As a result, economics and policy incentives could, in the near future, encourage expansion of cellulosic biofuels production from grasses, forest woody biomass, and agricultural and municipal wastes. If production expands, cultivation of cellulosic feedstock crops, such as switchgrass (Panicum virgatum L.) and miscanthus (Miscanthus species), is expected to increase dramatically. The main objective of this study is to identify grasslands in the Great Plains that are potentially suitable for cellulosic feedstock (such as switchgrass) production. Producing ethanol from noncropland holdings (such as grassland) will minimize the effects of biofuel developments on global food supplies. Our pilot study area is the Greater Platte River Basin, which includes a broad range of plant productivity from semiarid grasslands in the west to the fertile corn belt in the east. The Greater Platte River Basin was the subject of related U.S. Geological Survey (USGS) integrated research projects.

Production of deuterated switchgrass by hydroponic cultivation.

Science.gov (United States)

Evans, Barbara R; Bali, Garima; Foston, Marcus; Ragauskas, Arthur J; O'Neill, Hugh M; Shah, Riddhi; McGaughey, Joseph; Reeves, David; Rempe, Caroline S; Davison, Brian H

2015-07-01

The bioenergy crop switchgrass was grown hydroponically from tiller cuttings in 50 % D 2 O to obtain biomass with 34 % deuterium substitution and physicochemical properties similar to those of H 2 O-grown switchgrass controls. Deuterium enrichment of biological materials can potentially enable expanded experimental use of small angle neutron scattering (SANS) to investigate molecular structural transitions of complex systems such as plant cell walls. Two key advances have been made that facilitate cultivation of switchgrass, an important forage and biofuel crop, for controlled isotopic enrichment: (1) perfusion system with individual chambers and (2) hydroponic growth from tiller cuttings. Plants were grown and maintained for several months with periodic harvest. Photosynthetic activity was monitored by measurement of CO2 in outflow from the growth chambers. Plant morphology and composition appeared normal compared to matched controls grown with H2O. Using this improved method, gram quantities of switchgrass leaves and stems were produced by continuous hydroponic cultivation using growth medium consisting of basal mineral salts in 50 % D2O. Deuterium incorporation was confirmed by detection of the O-D and C-D stretching peaks with FTIR and quantified by (1)H- and (2)H-NMR. This capability to produce deuterated lignocellulosic biomass under controlled conditions will enhance investigation of cell wall structure and its deconstruction by neutron scattering and NMR techniques.

An empirical model to predict infield thin layer drying rate of cut switchgrass

International Nuclear Information System (INIS)

Khanchi, A.; Jones, C.L.; Sharma, B.; Huhnke, R.L.; Weckler, P.; Maness, N.O.

2013-01-01

A series of 62 thin layer drying experiments were conducted to evaluate the effect of solar radiation, vapor pressure deficit and wind speed on drying rate of switchgrass. An environmental chamber was fabricated that can simulate field drying conditions. An empirical drying model based on maturity stage of switchgrass was also developed during the study. It was observed that solar radiation was the most significant factor in improving the drying rate of switchgrass at seed shattering and seed shattered maturity stage. Therefore, drying switchgrass in wide swath to intercept the maximum amount of radiation at these stages of maturity is recommended. Moreover, it was observed that under low radiation intensity conditions, wind speed helps to improve the drying rate of switchgrass. Field operations such as raking or turning of the windrows are recommended to improve air circulation within a swath on cloudy days. Additionally, it was found that the effect of individual weather parameters on the drying rate of switchgrass was dependent on maturity stage. Vapor pressure deficit was strongly correlated with the drying rate during seed development stage whereas, vapor pressure deficit was weakly correlated during seed shattering and seed shattered stage. These findings suggest the importance of using separate drying rate models for each maturity stage of switchgrass. The empirical models developed in this study can predict the drying time of switchgrass based on the forecasted weather conditions so that the appropriate decisions can be made. -- Highlights: • An environmental chamber was developed in the present study to simulate field drying conditions. • An empirical model was developed that can estimate drying rate of switchgrass based on forecasted weather conditions. • Separate equations were developed based on maturity stage of switchgrass. • Designed environmental chamber can be used to evaluate the effect of other parameters that affect drying of crops

Compatibility of switchgrass as an energy crop in farming systems of the southeastern USA

Energy Technology Data Exchange (ETDEWEB)

Bransby, D.I.; Rodriguez-Kabana, R.; Sladden, S.E. [Auburn Univ., AL (United States)

1993-12-31

The objective of this paper is to examine the compatibility of switchgrass as an energy crop in farming systems in the southeastern USA, relative to other regions. In particular, the issues addressed are (1) competition between switchgrass as an energy crop and existing farm enterprises, based primarily on economic returns, (2) complementarity between switchgrass and existing farm enterprises, and (3) environmental benefits. Because projected economic returns for switchgrass as an energy crop are highest in the Southeast, and returns from forestry and beef pastures (the major existing enterprises) are low, there is a very strong economic incentive in this region. In contrast, based on current information, economic viability of switchgrass as an energy crop in other regions appears doubtful. In addition, switchgrass in the southeastern USA would complement forage-livestock production, row crop production and wildlife and would provide several additional environmental benefits. It is concluded that the southeastern USA offers the greatest opportunity for developing switchgrass as an economically viable energy crop.

Characteristics of Lignin Fractions from Dilute Acid Pretreated Switchgrass and Their Effect on Cellobiohydrolase from Trichoderma longibrachiatum

Directory of Open Access Journals (Sweden)

Lan Yao

2018-02-01

Full Text Available To investigate the interactions between acid pretreated switchgrass lignin and cellobiohydrolase (CBH, three different lignin fractions were isolated from dilute acid pretreated switchgrass by (i ethanol extraction, followed by (ii dioxane/H2O extraction, and (iii cellulase treatment, respectively. Structural properties of each lignin fraction were elucidated by GPC, 13C-NMR, and 2D-HSQC NMR analyses. The adsorptions of CBH to the isolated lignin fractions were also studied by Langmuir adsorption isotherms. Ethanol-extractable lignin fraction, mainly composed of syringyl (S and guaiacyl (G units, had the lowest molecular weight, while dioxane/H2O-extracted lignin fraction had the lowest S/G ratio with higher content of p-coumaric acid (pCA unit. The residual lignin fraction after enzymatic treatment had the highest S/G ratio without hydroxyphenyl (H unit. Strong associations were found between lignin properties such as lignin composition and S/G ratio and its non-productive enzyme adsorption factors including the maximum adsorption capacity and binding strength.

Association Mapping of Cell Wall Synthesis Regulatory Genes and Cell Wall Quality in Switchgrass

Energy Technology Data Exchange (ETDEWEB)

Bartley, Laura [Univ. of Oklahoma, Norman, OK (United States). Dept. of Microbiology and Plant Biology; Wu, Y. [Oklahoma State Univ., Stillwater, OK (United States); Zhu, L. [Oklahoma State Univ., Stillwater, OK (United States); Brummer, E. C. [Noble Foundation, Ardmore, OK (United States); Saha, M. [Noble Foundation, Ardmore, OK (United States)

2016-05-31

Inefficient conversion of biomass to biofuels is one of the main barriers for biofuel production from such materials. Approximately half of polysaccharides in biomass remain unused by typical biochemical conversion methods. Conversion efficiency is influenced by the composition and structure of cell walls of biomass. Grasses such as wheat, maize, and rice, as well as dedicated perennial bioenergy crops, like switchgrass, make up ~55% of biomass that can be produced in the United States. Grass cell walls have a different composition and patterning compared with dicotyledonous plants, including the well-studied model plant, Arabidopsis. This project identified genetic determinants of cell wall composition in grasses using both naturally occurring genetic variation of switchgrass and gene network reconstruction and functional assays in rice. In addition, the project linked functional data in rice and other species to switchgrass improvement efforts through curation of the most abundant class of regulators in the switchgrass genome. Characterizing natural diversity of switchgrass for variation in cell wall composition and properties, also known as quality, provides an unbiased avenue for identifying biologically viable diversity in switchgrass cell walls. To characterizing natural diversity, this project generated cell wall composition and enzymatic deconstruction data for ~450 genotypes of the Switchgrass Southern Association Collection (SSAC), a diverse collection composed of 36 switchgrass accessions from the southern U.S. distribution of switchgrass. Comparing these data with other measures of cell wall quality for the same samples demonstrated the complementary nature of the diverse characterization platforms now being used for biomass characterization. Association of the composition data with ~3.2K single nucleotide variant markers identified six significant single nucleotide variant markers co-associated with digestibility and another compositional trait. These

Evaluation of biogas production potential by dry anaerobic digestion of switchgrass--animal manure mixtures.

Science.gov (United States)

Ahn, H K; Smith, M C; Kondrad, S L; White, J W

2010-02-01

Anaerobic digestion is a biological method used to convert organic wastes into a stable product for land application with reduced environmental impacts. The biogas produced can be used as an alternative renewable energy source. Dry anaerobic digestion [>15% total solid (TS)] has an advantage over wet digestion (anaerobic digestion of animal manure-switchgrass mixture was evaluated under dry (15% TS) and thermophilic conditions (55 degrees C). Three different mixtures of animal manure (swine, poultry, and dairy) and switchgrass were digested using batch-operated 1-L reactors. The swine manure test units showed 52.9% volatile solids (VS) removal during the 62-day trial, while dairy and poultry manure test units showed 9.3% and 20.2%, respectively. Over the 62 day digestion, the swine manure test units yielded the highest amount of methane 0.337 L CH4/g VS, while the dairy and poultry manure test units showed very poor methane yield 0.028 L CH4/g VS and 0.002 L CH4/g VS, respectively. Although dairy and poultry manure performed poorly, they may still have high potential as biomass for dry anaerobic digestion if appropriate designs are developed to prevent significant volatile fatty acid (VFA) accumulation and pH drop.

A geospatial suitability model for drought-tolerant switchgrass

Science.gov (United States)

Lewis, S. M.; Kelly, M.

2011-12-01

A perennial grass native to the North America, switchgrass (Panicum virgatum) has been targeted by the USDA as a model mass bioenergy crop to replace petroleum energy products and meet policy demands. Although highly water use efficient, as a warm-season crop, switchgrass requires a significant amount of water during the growing season (April -September). However, locations that have highly reliable water availability are also ideal for profitable food crops (e.g. corn and soy growing regions) and food competition is a significant concern in regards to biofuel crops being grown on productive agricultural lands. Drier, marginal lands (lands on which normal agricultural crops are difficult to cultivate) are therefore potentially ideal locations to grow biofuel crops to ensure that food competition is not an issue. Genetics scientists at UC Davis are in the process of developing a modified variety of switchgrass that can withstand extended periods of drought while not substantially affecting overall yield. As this product is being developed, it is important to identify the potential geographical niche for this new drought-tolerant variety of switchgrass. This project introduces a geospatial approach that utilizes both physical and economic variables to identify ideal geographic locations for this innovative crop.

Effects of nitrogen fertilization on biomass yield and quality in large fields of established switchgrass in southern Iowa, USA

Energy Technology Data Exchange (ETDEWEB)

Lemus, Roque [Department of Agricultural Sciences, Texas A and M University, Commerce, TX 75429 (United States); Charles Brummer, E. [Center for Applied Genetic Technologies, University of Georgia, Athens, GA 30602 (United States); Lee Burras, C.; Moore, Kenneth J.; Barker, Michael F. [Department of Agronomy, Iowa State University, Ames, IA 50011 (United States); Molstad, Neil E. [USDA-NRCS Hawaii Resource Office, 101 Aupuni Street Suite 229, Hilo, HI 96720 (United States)

2008-12-15

Switchgrass (Panicum virgatum L.) is a potential biofuel crop in the midwestern United States. The objective of this experiment was to test the effect of nitrogen application on biomass dry matter yield and fiber and mineral concentrations in large field plots in Lucas and Wayne counties in southern Iowa. Two established switchgrass fields with a previous history of limited management were evaluated from 1998 through 2002. Nitrogen was applied in the spring at rates of 0, 56, 112, and 224 kg N ha{sup -1}, and a single biomass harvest was made in autumn. Biomass production averaged across locations and N levels increased by 3.6 mg ha{sup -1} between 1998 and 2002 to 6.5 mg ha{sup -1}. Nitrogen improved yields, with the response declining as N levels increased. The highest yield throughout the experiment was 8.5 mg ha{sup -1} at the Lucas location in 2002. Changes in fiber and mineral concentrations did not follow any trend over years but were likely due to differences in harvest date among years. Nitrogen fertilization had no meaningful effect on the quality of the biofuel produced. This study clearly shows that nitrogen application and proper agronomic management can substantially increase the yield of established switchgrass fields over time without affecting the quality of the feedstock. As this experiment was conducted in large plots using commercial farm machinery, the results should be broadly applicable to real world situations. (author)

Investigation of Pleurotus ostreatus pretreatment on switchgrass for ethanol production

Science.gov (United States)

Slavens, Shelyn Gehle

Fungal pretreatment using the white-rot fungus Pleurotus ostreatus on switchgrass for ethanol production was studied. In a small-scale storage study, small switchgrass bales were inoculated with fungal spawn and automatically watered to maintain moisture. Sampled at 25, 53, and 81 d, the switchgrass composition was determined and liquid hot water (LHW) pretreatment was conducted. Fungal pretreatment significantly decreased the xylan and lignin content; glucan was not significantly affected by fungal loading. The glucan, xylan, and lignin contents significantly decreased with increased fungal pretreatment time. The effects of the fungal pretreatment were not highly evident after the LHW pretreatment, showing only changes based on sampling time. Although other biological activity within the bales increased cellulose degradation, the fungal pretreatment successfully reduced the switchgrass lignin and hemicellulose contents. In a laboratory-scale nutrient supplementation study, copper, manganese, glucose, or water was added to switchgrass to induce production of ligninolytic enzymes by P. ostreatus. After 40 d, ligninolytic enzyme activities and biomass composition were determined and simultaneous saccharification and fermentation (SSF) was conducted to determine ethanol yield. Laccase activity was similar for all supplements and manganese peroxidase (MnP) activity was significantly less in copper-treated samples than in the other fungal-inoculated samples. The fungal pretreatment reduced glucan, xylan, and lignin content, while increasing extractable sugars content. The lowest lignin contents occurred in the water-fungal treated samples and produced the greatest ethanol yields. The greatest lignin contents occurred in the copper-fungal treated samples and produced the lowest ethanol yields. Manganese-fungal and glucose-fungal treated samples had similar, intermediate lignin contents and produced similar, intermediate ethanol yields. Ethanol yields from switchgrass

Historical Perspective on How and Why Switchgrass was Selected as a "Model" High-Potential Energy Crop

Energy Technology Data Exchange (ETDEWEB)

Wright, Lynn L [ORNL

2007-11-01

A review of several publications of the Biofuels Feedstock Development Program, and final reports from the herbaceous crop screening trials suggests that there were several technical and non-technical factors that influenced the decision to focus on one herbaceous "model" crop species. The screening trials funded by the U.S. Department of Energy in the late 1980's to early 1990's assessed a wide range of about 34 species with trials being conducted on a wide range of soil types in 31 different sites spread over seven states in crop producing regions of the U.S. While several species, including sorghums, reed canarygrass and other crops, were identified as having merit for further development, the majority of institutions involved in the herbaceous species screening studies identified switchgrass as having high priority for further development. Six of the seven institutions included switchgrass among the species recommended for further development in their region and all institutions recommended that perennial grasses be given high research priority. Reasons for the selection of switchgrass included the demonstration of relatively high, reliable productivity across a wide geographical range, suitability for marginal quality land, low water and nutrient requirements, and positive environmental attributes. Economic and environmental assessments by Oak Ridge National Laboratory's Biofuels Feedstock Development Program staff together with the screening project results, and funding limitations lead to making the decision to further develop only switchgrass as a "model" or "prototype" species in about 1990. This paper describes the conditions under which the herbaceous species were screened, summarizes results from those trials, discusses the various factors which influenced the selection of switchgrass, and provides a brief evaluation of switchgrass with respect to criteria that should be considered when selecting and developing a crop for biofuels and

Policy incentives for switchgrass production using valuation of non-market ecosystem services

International Nuclear Information System (INIS)

Chamberlain, Jim F.; Miller, Shelie A.

2012-01-01

This study presents a linear profit model with combined economic and environmental factors for a switchgrass-for-biofuels agricultural system in the southeastern U.S. The objectives are to establish conversion-to-switchgrass thresholds for various market prices and identify policy incentives that would ensure economic profit while also maximizing environmental benefits (carbon sequestration, displacement of fossil fuels) and minimizing negative impacts (global warming potential, nitrate loss). Weighting factors are chosen to represent incentives and penalties by assigning value to the impacts. With no other incentives, switchgrass market prices of at least $51 and $58/dton would be needed in order to make a profitable switch from corn/Conservation Reserve Program (CRP) lands and cotton, respectively. At a mid-range offering of $50/dton, feasible carbon credit prices of $3/ $8/ $23 per metric tonne CO 2 e would incentivize conversion from corn, CRP, or cotton, respectively. Similarly, a water quality penalty of $0.20/ $3/ $2 per kilogram NO 3 –N leached would incentivize the same conversions with resultant watershed improvement. At a lower price of $30/dton switchgrass, incentives based on valuation of ecosystem services begin to exceed feasible ranges of these valuations. - Highlights: ► A linear effective profit model predicts conversion thresholds to switchgrass. ► Carbon and nitrogen fluxes can be valued and incorporated into producer choices. ► Farmgate prices alone of $51 and $58/dton switchgrass will entice conversion. ► Reasonable ecosystem service valuations will encourage adoption of switchgrass.

Switchgrass harvest time management can impact biomass yield and nutrient content

Science.gov (United States)

Switchgrass (Panicum virgatum L.) is a dedicated energy crop native to much of North America. While high-biomass yield is of significant importance for the development of switchgrass as a bioenergy crop, nutrient content in the biomass as it relates to biofuel conversion efficiency is also critical...

Environmental and economic analysis of switchgrass production for water quality improvement in northeast Kansas.

Science.gov (United States)

Nelson, Richard G; Ascough, James C; Langemeier, Michael R

2006-06-01

The primary objectives of this research were to determine SWAT model predicted reductions in four water quality indicators (sediment yield, surface runoff, nitrate nitrogen (NO(3)-N) in surface runoff, and edge-of-field erosion) associated with producing switchgrass (Panicum virgatum) on cropland in the Delaware basin in northeast Kansas, and evaluate switchgrass break-even prices. The magnitude of potential switchgrass water quality payments based on using switchgrass as an alternative energy source was also estimated. SWAT model simulations showed that between 527,000 and 1.27 million metric tons (Mg) of switchgrass could be produced annually across the basin depending upon nitrogen (N) fertilizer application levels (0-224 kg N ha(-1)). The predicted reductions in sediment yield, surface runoff, NO(3)-N in surface runoff, and edge-of-field erosion as a result of switchgrass plantings were 99, 55, 34, and 98%, respectively. The average annual cost per hectare for switchgrass ranged from about 190 US dollars with no N applied to around 345 US dollars at 224 kg N ha(-1) applied. Edge-of-field break-even price per Mg ranged from around 41 US dollars with no N applied to slightly less than 25 US dollars at 224 kg N ha(-1) applied. A majority of the switchgrass produced had an edge-of-field break-even price of 30 Mg(-1) US dollars or less. Savings of at least 50% in each of the four water quality indicators could be attained for an edge-of-field break-even price of 22-27.49 US dollars Mg(-1).

Mapping marginal croplands suitable for cellulosic feedstock crops in the Great Plains, United States

Science.gov (United States)

Gu, Yingxin; Wylie, Bruce K.

2016-01-01

Growing cellulosic feedstock crops (e.g., switchgrass) for biofuel is more environmentally sustainable than corn-based ethanol. Specifically, this practice can reduce soil erosion and water quality impairment from pesticides and fertilizer, improve ecosystem services and sustainability (e.g., serve as carbon sinks), and minimize impacts on global food supplies. The main goal of this study was to identify high-risk marginal croplands that are potentially suitable for growing cellulosic feedstock crops (e.g., switchgrass) in the US Great Plains (GP). Satellite-derived growing season Normalized Difference Vegetation Index, a switchgrass biomass productivity map obtained from a previous study, US Geological Survey (USGS) irrigation and crop masks, and US Department of Agriculture (USDA) crop indemnity maps for the GP were used in this study. Our hypothesis was that croplands with relatively low crop yield but high productivity potential for switchgrass may be suitable for converting to switchgrass. Areas with relatively low crop indemnity (crop indemnity marginal croplands in the GP are potentially suitable for switchgrass development. The total estimated switchgrass biomass productivity gain from these suitable areas is about 5.9 million metric tons. Switchgrass can be cultivated in either lowland or upland regions in the GP depending on the local soil and environmental conditions. This study improves our understanding of ecosystem services and the sustainability of cropland systems in the GP. Results from this study provide useful information to land managers for making informed decisions regarding switchgrass development in the GP.

Low-heat, mild alkaline pretreatment of switchgrass for anaerobic digestion.

Science.gov (United States)

Jin, Guang; Bierma, Tom; Walker, Paul M

2014-01-01

This study examines the effectiveness of alkaline pretreatment under mild heat conditions (100°C or 212°F) on the anaerobic co-digestion of switchgrass. The effects of alkaline concentration, types of alkaline, heating time and rinsing were evaluated. In addition to batch studies, continuous-feed studies were performed in triplicate to identify potential digester operational problems caused by switchgrass co-digestion while accounting for uncertainty due to digester variability. Few studies have examined anaerobic digestion of switchgrass or the effects of mild heating to enhance alkaline pretreatment prior to biomass digestion. Results indicate that pretreatment can significantly enhance digestion of coarse-ground (≤ 0.78 cm particle size) switchgrass. Energy conversion efficiency as high as 63% was observed, and was comparable or superior to fine-grinding as a pretreatment method. The optimal NaOH concentration was found to be 5.5% (wt/wt alkaline/biomass) with a 91.7% moisture level. No evidence of operational problems such as solids build-up, poor mixing, or floating materials were observed. These results suggest the use of waste heat from a generator could reduce the concentration of alkaline required to adequately pretreat lignocellulosic feedstock prior to anaerobic digestion.

Towards uncovering the roles of switchgrass peroxidases in plant processes

Directory of Open Access Journals (Sweden)

Aaron eSaathoff

2013-06-01

Full Text Available Herbaceous perennial plants selected as potential biofuel feedstocks had been understudied at the genomic and functional genomic levels. Recent investments, primarily by the U.S. Department of Energy, have led to the development of a number of molecular resources for bioenergy grasses, such as the partially annotated genome for switchgrass (Panicum virgatum L., and some related diploid species. In its current version, the switchgrass genome contains 65,878 gene models arising from the A and B genomes of this tetraploid grass. The availability of these gene sequences provides a framework to exploit transcriptomic data obtained from next generation sequencing platforms to address questions of biological importance. One such question pertains to discovery of genes and proteins important for biotic and abiotic stress responses, and how these components might affect biomass quality and stress response in plants engineered for a specific end purpose. It can be expected that production of switchgrass on marginal lands will expose plants to diverse stresses, including herbivory by insects. Class III plant peroxidases have been implicated in many developmental responses such as lignification and in the adaptive responses of plants to insect feeding. Here, we have analyzed the class III peroxidases encoded by the switchgrass genome, and have mined available transcriptomic datasets to develop a first understanding of the expression profiles of the class III peroxidases in different plant tissues. Lastly, we have identified switchgrass peroxidases that appear to be orthologs of enzymes shown to play key roles in lignification and plant defense responses to hemipterans.

Developing Switchgrass as a Bioenergy Crop

Energy Technology Data Exchange (ETDEWEB)

Bouton, J.; Bransby, D.; Conger, B.; McLaughlin, S.; Ocumpaugh, W.; Parrish, D.; Taliaferro, C.; Vogel, K.; Wullschleger, S.

1998-11-08

The utilization of energy crops produced on American farms as a source of renewable fuels is a concept with great relevance to current ecological and economic issues at both national and global scales. Development of a significant national capacity to utilize perennial forage crops, such as switchgrass (Panicum virgatum, L.) as biofuels could benefit our agricultural economy by providing an important new source of income for farmers. In addition energy production from perennial cropping systems, which are compatible with conventional fining practices, would help reduce degradation of agricultural soils, lower national dependence on foreign oil supplies, and reduce emissions of greenhouse gases and toxic pollutants to the atmosphere (McLaughlin 1998). Interestingly, on-farm energy production is a very old concept, extending back to 19th century America when both transpofiation and work on the farm were powered by approximately 27 million draft animals and fueled by 34 million hectares of grasslands (Vogel 1996). Today a new form of energy production is envisioned for some of this same acreage. The method of energy production is exactly the same - solar energy captured in photosynthesis, but the subsequent modes of energy conversion are vastly different, leading to the production of electricity, transportation fuels, and chemicals from the renewable feedstocks. While energy prices in the United States are among the cheapest in the world, the issues of high dependency on imported oil, the uncertainties of maintaining stable supplies of imported oil from finite reserves, and the environmental costs associated with mining, processing, and combusting fossil fuels have been important drivers in the search for cleaner burning fuels that can be produced and renewed from the landscape. At present biomass and bioenergy combine provide only about 4% of the total primary energy used in the U.S. (Overend 1997). By contrast, imported oil accounts for approximately 44% of the

Preference by horses for bedding pellets made from switchgrass (Panicum virgatum) straw

Science.gov (United States)

The bedding system used for stalled horses can impact their health and well-being. This study examined the saponin concentration in switchgrass (Panicum virgatum) straw, and bedding pellets made from switchgrass straw. Further, this study determined the palatability of bedding pellets made from sw...

Isolation, Characterization, and Quantification of Steroidal Saponins in Switchgrass (Panicum virgatum L.)

Science.gov (United States)

Switchgrass (Panicum virgatum L.) has been identified for development into an efficient and environment friendly biomass energy crop. A recent five-year study demonstrated that switchgrass grown for biofuel production produced 540 percent more energy than what is needed to grow, harvest and process...

Depolymerization and hydrodeoxygenation of switchgrass lignin with formic acid.

Science.gov (United States)

Xu, Weiyin; Miller, Stephen J; Agrawal, Pradeep K; Jones, Christopher W

2012-04-01

Organosolv switchgrass lignin is depolymerized and hydrodeoxygenated with a formic acid hydrogen source, 20 wt % Pt/C catalyst, and ethanol solvent. The combination of formic acid and Pt/C is found to promote production of higher fractions of lower molecular weight compounds in the liquid products. After 4 h of reaction, all of the switchgrass lignin is solubilized and 21 wt % of the biomass is shown to be converted into seven prominent molecular species that are identified and quantified. Reaction time is shown to be an important variable in affecting changes in product distributions and bulk liquid product properties. At 20 h of reaction, the lignin is significantly depolymerized to form liquid products with a 76 % reduction in the weighted average molecular weight. Elemental analysis also shows that the resultant liquid products have a 50 % reduction in O/C and 10 % increase in H/C molar ratios compared to the switchgrass lignin after 20 h. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A review of carbon and nitrogen balances in switchgrass grown for energy

International Nuclear Information System (INIS)

Bransby, D.I.; McLaughlin, S.B.; Parrish, D.J.

1998-01-01

Increased atmospheric CO 2 caused partly by burning fossil fuels, is assumed to elevate the risk of global warming, while nitrate contamination of surface runoff and groundwater from fertilizer and agricultural wastes constitutes a serious environmental hazard on a regional scale. Switchgrass (Panicum virgatum L.) grown as an energy crop could reduce atmospheric CO 2 accumulation by replacing fossil fuels and sequestering C. It could also improve soil productivity by C sequestration, and reduce NO 3 -1 contamination of water by absorbing N lost from fertilizer and agricultural waste if planted in filter strips on adjacent land. The objective of this study was to assess potential impacts of switchgrass on C and N balances by reviewing and synthesizing information from current literature, unpublished data and on-going research. Replacing fossil fuels with switchgrass, or any other biomass, will have a much greater effect on atmospheric CO 2 than C sequestration. This is because replacing fossil fuels provides a cumulative effect, while C sequestration offers only a one-time benefit. Furthermore, switchgrass will provide net gains in C sequestration only if it replaces annual row crops, but not if it replaces grazed pasture. Nitrogen recovery by switchgrass in an Alabama study was 65.6%, which compares favorably with the 50% recovery frequently quoted as the norm for wheat (Triticum aestivum L.) and corn (Zea mays L.). (Author)

Switchgrass, Bermudagrass, Flaccidgrass, and Lovegrass biomass yield response to nitrogen for single and double harvest

International Nuclear Information System (INIS)

Aravindhakshan, Sijesh C.; Epplin, Francis M.; Taliaferro, Charles M.

2011-01-01

Switchgrass (Panicum virgatum) has been identified as a model dedicated energy crop species. After a perennial grass is established, the major variable costs are for nitrogen (N) fertilizer and harvest. Prior to establishing switchgrass on millions of ha in a particular agro-climatic region, it would be useful to determine switchgrass yield response to N and its response to harvest frequency relative to alternative grass species. The objective of this research is to determine biomass yield response to N for four perennial grass species and to determine the species, N level, and harvest frequency that will maximize expected net returns, given the climate and soils of the U.S.A. Southern Plains. Yield data were produced in an experiment that includes four species (switchgrass, bermudagrass (Cynodon dactylon), weeping lovegrass (Eragrostis curvula), and carostan flaccidgrass (Pennisetum flaccidum)), four N levels, and two harvest levels. Linear response plateau (LRP), linear response stochastic plateau (LRSP), and quadratic response (QR) functions are estimated. For all combinations of biomass and N prices considered, the optimal species is switchgrass. For most price situations, it is economically optimal to fertilize established stands of switchgrass with 69 kg N ha -1 yr -1 and to harvest once yr -1 after senescence.

Switchgrass, Bermudagrass, Flaccidgrass, and Lovegrass biomass yield response to nitrogen for single and double harvest

Energy Technology Data Exchange (ETDEWEB)

Aravindhakshan, Sijesh C.; Epplin, Francis M. [Department of Agricultural Economics, Oklahoma State University, Stillwater, OK 74078-6026 (United States); Taliaferro, Charles M. [Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078 (United States)

2011-01-15

Switchgrass (Panicum virgatum) has been identified as a model dedicated energy crop species. After a perennial grass is established, the major variable costs are for nitrogen (N) fertilizer and harvest. Prior to establishing switchgrass on millions of ha in a particular agro-climatic region, it would be useful to determine switchgrass yield response to N and its response to harvest frequency relative to alternative grass species. The objective of this research is to determine biomass yield response to N for four perennial grass species and to determine the species, N level, and harvest frequency that will maximize expected net returns, given the climate and soils of the U.S.A. Southern Plains. Yield data were produced in an experiment that includes four species (switchgrass, bermudagrass (Cynodon dactylon), weeping lovegrass (Eragrostis curvula), and carostan flaccidgrass (Pennisetum flaccidum)), four N levels, and two harvest levels. Linear response plateau (LRP), linear response stochastic plateau (LRSP), and quadratic response (QR) functions are estimated. For all combinations of biomass and N prices considered, the optimal species is switchgrass. For most price situations, it is economically optimal to fertilize established stands of switchgrass with 69 kg N ha{sup -1} yr{sup -1} and to harvest once yr{sup -1} after senescence. (author)

Co-processing of agricultural plastic waste and switchgrass via tail gas reactive pyrolysis

Science.gov (United States)

Mixtures of agricultural plastic waste in the form of polyethylene hay bale covers (PE) (4-37%) and switchgrass were investigated using the US Department of Agriculture’s tail gas reactive pyrolysis (TGRP) at different temperatures (400-570 deg C). TGRP of switchgrass and plastic mixtures significan...

Integrating future scenario‐based crop expansion and crop conditions to map switchgrass biofuel potential in eastern Nebraska, USA

Science.gov (United States)

Gu, Yingxin; Wylie, Bruce K.

2018-01-01

Switchgrass (Panicum virgatum) has been evaluated as one potential source for cellulosic biofuel feedstocks. Planting switchgrass in marginal croplands and waterway buffers can reduce soil erosion, improve water quality, and improve regional ecosystem services (i.e. it serves as a potential carbon sink). In previous studies, we mapped high risk marginal croplands and highly erodible cropland buffers that are potentially suitable for switchgrass development, which would improve ecosystem services and minimally impact food production. In this study, we advance our previous study results and integrate future crop expansion information to develop a switchgrass biofuel potential ensemble map for current and future croplands in eastern Nebraska. The switchgrass biomass productivity and carbon benefits (i.e. NEP: net ecosystem production) for the identified biofuel potential ensemble areas were quantified. The future scenario‐based (‘A1B’) land use and land cover map for 2050, the US Geological Survey crop type and Compound Topographic Index (CTI) maps, and long‐term (1981–2010) averaged annual precipitation data were used to identify future crop expansion regions that are suitable for switchgrass development. Results show that 2528 km2 of future crop expansion regions (~3.6% of the study area) are potentially suitable for switchgrass development. The total estimated biofuel potential ensemble area (including cropland buffers, marginal croplands, and future crop expansion regions) is 4232 km2 (~6% of the study area), potentially producing 3.52 million metric tons of switchgrass biomass per year. Converting biofuel ensemble regions to switchgrass leads to potential carbon sinks (the total NEP for biofuel potential areas is 0.45 million metric tons C) and is environmentally sustainable. Results from this study improve our understanding of environmental conditions and ecosystem services of current and future cropland systems in eastern Nebraska and provide

Analysis of environmental and economic tradeoffs in switchgrass supply chains for biofuel production

International Nuclear Information System (INIS)

Zhong, Jia; Yu, T. Edward; Larson, James A.; English, Burton C.; Fu, Joshua S.; Calcagno, James

2016-01-01

This study considered the environmental advantages of switchgrass, along with the economic challenges in its logistics, in the design of a sustainable switchgrass supply chain in Tennessee. Applying a multi-objective optimization model to high-resolution spatial data, potential tradeoffs among the objectives of minimizing feedstock costs, GHG (greenhouse gas) emissions, and soil erosion were identified for a set of conversion facilities on an efficient frontier. The tradeoff relationship was primarily driven by the type of agricultural land converted to switchgrass. Hay and pasture lands were more cost effective but resulted in higher soil carbon losses and soil erosion after being converted to switchgrass. Converting crop lands reduced GHG emissions and soil erosion but caused higher feedstock cost primarily due to the higher opportunity cost of land use. The respective average costs of abating GHG emissions and soil erosion on the efficient frontier were $2378 Mg"−"1 and $10 Mg"−"1. The compromise solution conversion facility site generated 63% higher feedstock cost compared to the cost minimizing location, while reducing soil erosion by 70 fold and diminishing GHG emissions by 27%. Reducing soil erosion may be a more cost effective environmental criterion than reducing GHG emissions in developing a sustainable switchgrass supply chain in Tennessee. - Highlights: • Multi-objective optimization is applied to a switchgrass supply chain in Tennessee. • Tradeoffs are identified among costs, greenhouse gas, and soil erosion in supply chain. • The type of agricultural land converted to feedstock is a key factor to the tradeoffs. • Abating soil erosion rather than greenhouse gas is more cost effective in Tennessee.

Allelopathic Potential of Switchgrass ( Panicum virgatum L.) on Perennial Ryegrass ( Lolium perenne L.) and Alfalfa ( Medicago sativa L.)

Science.gov (United States)

Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

2010-10-01

This study investigated allelopathy and its chemical basis in nine switchgrass ( Panicum virgatum L.) accessions. Perennial ryegrass ( Lolium perenne L.) and alfalfa ( Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China’s Loess Plateau.

Generation of Transcript Assemblies and Identification of Single Nucleotide Polymorphisms from Seven Lowland and Upland Cultivars of Switchgrass

Directory of Open Access Journals (Sweden)

Kevin L. Childs

2014-07-01

Full Text Available Switchgrass is a North American perennial prairie species that has been used as a rangeland and forage crop and has recently been targeted as a potential biofuel feedstock species. Switchgrass, which occurs as tetraploid and octoploid forms, is classified into lowland or upland ecotypes that differ in growth phenotypes and adaptation to distinct habitats. Using RNA-sequencing (RNA-seq reads derived from crown, young shoot, and leaf tissues, we generated sequence data from seven switchgrass cultivars, three lowland and four upland, to enable comparative analyses between switchgrass cultivars and to identify single nucleotide polymorphisms (SNPs for use in breeding and genetic analysis. We also generated individual transcript assemblies for each of the cultivars. Transcript data indicate that subgenomes of octoploid switchgrass are not substantially different from subgenomes of tetraploids as expected for an autopolyploid origin of switchgrass octoploids. Using RNA-seq reads aligned to the switchgrass Release 0 AP13 reference genome, we identified 1,305,976 high-confidence SNPs. Of these SNPs, 438,464 were unique to lowland cultivars, but only 12,002 were found in all lowlands. Conversely, 723,678 SNPs were unique to upland cultivars, with only 34,665 observed in all uplands. Comparison of our high-confidence transcriptome-derived SNPs with SNPs previously identified in a genotyping-by-sequencing (GBS study of an association panel revealed limited overlap between the two methods, highlighting the utility of transcriptome-based SNP discovery in augmenting genome diversity polymorphism datasets. The transcript and SNP data described here provide a useful resource for switchgrass gene annotation and marker-based analyses of the switchgrass genome.

Research and Technology Development for Genetic Improvement of Switchgrass

Energy Technology Data Exchange (ETDEWEB)

Kausch, Albert [Univ. of Rhode Island, Kingston, RI (United States); Rhodes, Richard [Univ. of Rhode Island, Kingston, RI (United States)

2017-05-02

This research adds to the understanding of switchgrass genetics and the increasing of biomass relevant to production of bioenergy. Switchgrass, Panicum virgatum L., and its related species are well known as potential bioenergy crops since the early 1990s. There are global economic, political, US national security and environmental pressures to increase renewable biofuel production and utilization to offset gasoline and diesel fuel use and climate change, especially in the liquid fuel transportation sector. To realize the potential of bioenergy crops, rapid genetic improvement of the most promising perennial grass feedstocks, such as switchgrass, are anticipated by current genomics, association genetics, marker assisted breeding, hybrid plant development, advanced tissue culture, conventional genetics and other approaches to increase yield, processability, and regional adaptation. The technical effectiveness and economic feasibility of the methods or techniques investigated are demonstrated by several publications, presentations and patents produced as an outcome and deliverable of this research. This project is of a broad benefit to the public not only through the dissemination of this information but also to the development of new methods which will be applied to future bioenergy crop improvement as well as other crops.

Genome-size variation in switchgrass (Panicum virgatum): flow cytometry and cytology reveal rampant aneuploidy

Science.gov (United States)

Switchgrass (Panicum virgatum L.), a native perennial dominant of the prairies of North America, has been targeted as a model herbaceous species for biofeedstock development. A flow-cytometric survey of a core set of 11 primarily upland polyploid switchgrass accessions indicated that there was con...

Investigating the impact of biomass quality on near-infrared models for switchgrass feedstocks

Directory of Open Access Journals (Sweden)

Lindsey M. Kline

2015-12-01

Full Text Available The aim of this study was to determine the impact of incorporating switchgrass samples that have been in long term storage on the development of near-infrared (NIR multivariate calibration models and their predictive capabilities. Stored material contains more variation in their respective spectral signatures due to chemical changes in the bales with storage time. Partial least squares (PLS regression models constructed using NIR spectra of stored switchgrass possessed an instability that interfered with the correlation between the spectral data and measured chemical composition. The models were improved using calibration sample sets of equal parts stored and fresh switchgrass to more accurately predict the chemical composition of stored switchgrass. Acceptable correlation values (rcalibration were obtained using a calibration sample set composed of 25 stored samples and 25 samples of fresh switchgrass for cellulose (0.91, hemicellulose (0.74, total carbohydrates (0.76, lignin (0.98, extractives (0.92, and ash (0.87. Increasing the calibration sample set to 100 samples of equal parts stored to senesced material resulted in statistically increased (p = 0.05 correlations for total carbohydrates (0.89 and ash (0.96. When these models were applied to a separate validation set (equal to 10% of the calibration sample set, high correlation coefficients (r for predicted versus measured constituent content were observed for cellulose (0.94, total carbohydrates (0.98, lignin (0.91, extractives (0.97, and ash (0.90. For optimization of processing economics, the impact of feedstock storage must be investigated for implementation in conversion processes. While NIR is a well-known high-throughput technique for characterization of senesced switchgrass, the selection of appropriate calibration samples and consequent multivariate models must be taken into careful consideration for NIR application in a biomass storage facility for rapid chemical compositional

Impact of harvesting time on ultimate methane yield of switchgrass grown in eastern Canada

Energy Technology Data Exchange (ETDEWEB)

Gilbert, Y.; Masse, D. [Agriculture and Agri-Food Canada, Sherbrooke, PQ (Canada). Dairy and Swine Research and Development Centre; Savoie, P.; Belanger, G.; Parent, G. [Agriculture and Agri-Food Canada, Quebec City, PQ (Canada). Soils and Crops Research and Development Centre; Babineau, D.L. [Groupe EBI, Berthierville, PQ (Canada)

2010-07-01

European research in green energy production from crops has resulted in the development of full scale bioreactors that use energy crops as feedstock. Switchgrass has been touted as one of the most promising crops for energy production among several perennial grass species grown under moderate to hot climates. However, few studies have been conducted in colder climate conditions. This study examined the mesophilic methane yield of switchgrass grown under the cooler growing conditions that exist in northeastern North America. In 2007, switchgrass was harvested in late July, August and September and conserved as silage. The regrowth of plots harvested in late July was also harvested in late September as a two-cut strategy. A 30 L small-scale laboratory digester was used to anaerobically digest the switchgrass silage samples. Specific methane yield decreased considerably with advancing plant development, but was similar between the first harvest in late July and the regrowth in late September. Nearly 25 per cent more methane could be produced by hectare for the two-cut strategy compared to harvesting once in late August. It was concluded that additional studies are needed to determine the effect of cutting times and strategies on the long term yield of switchgrass and to establish the production cost of this renewable energy.

New genomic resources for switchgrass: a BAC library and comparative analysis of homoeologous genomic regions harboring bioenergy traits

Directory of Open Access Journals (Sweden)

Feltus Frank A

2011-07-01

Full Text Available Abstract Background Switchgrass, a C4 species and a warm-season grass native to the prairies of North America, has been targeted for development into an herbaceous biomass fuel crop. Genetic improvement of switchgrass feedstock traits through marker-assisted breeding and biotechnology approaches calls for genomic tools development. Establishment of integrated physical and genetic maps for switchgrass will accelerate mapping of value added traits useful to breeding programs and to isolate important target genes using map based cloning. The reported polyploidy series in switchgrass ranges from diploid (2X = 18 to duodecaploid (12X = 108. Like in other large, repeat-rich plant genomes, this genomic complexity will hinder whole genome sequencing efforts. An extensive physical map providing enough information to resolve the homoeologous genomes would provide the necessary framework for accurate assembly of the switchgrass genome. Results A switchgrass BAC library constructed by partial digestion of nuclear DNA with EcoRI contains 147,456 clones covering the effective genome approximately 10 times based on a genome size of 3.2 Gigabases (~1.6 Gb effective. Restriction digestion and PFGE analysis of 234 randomly chosen BACs indicated that 95% of the clones contained inserts, ranging from 60 to 180 kb with an average of 120 kb. Comparative sequence analysis of two homoeologous genomic regions harboring orthologs of the rice OsBRI1 locus, a low-copy gene encoding a putative protein kinase and associated with biomass, revealed that orthologous clones from homoeologous chromosomes can be unambiguously distinguished from each other and correctly assembled to respective fingerprint contigs. Thus, the data obtained not only provide genomic resources for further analysis of switchgrass genome, but also improve efforts for an accurate genome sequencing strategy. Conclusions The construction of the first switchgrass BAC library and comparative analysis of

Development of a Low Input and sustainable Switchgrass Feedstock Production System Utilizing Beneficial Bacterial Endophytes

Energy Technology Data Exchange (ETDEWEB)

Mei, Chuansheng [IALR; Nowak, Jerzy [VPISU; Seiler, John [VPISU

2014-10-24

regenerated, and their gene expression levels determined using qPCR. Consequently high, medium and low expression lines were propagated in vitro for gene function study. When adequate numbers of individual transgenic lines were obtained, they were challenged with PsJN to see if PsJN promotes or inhibits growth of transgenic plants. Our results demonstrated that EF-622 overexpression, ZF-371, GST, H-221 and CAM RNAi transgenic lines lost responses to PsJN, i.e. PsJN had no growth promotive effects on these transgenic plants. Further study needs to be done to characterize this loss of responsiveness to PsJN. During this funding period, we have done more work related to this funded project and established collaborations with other institutions and obtained some interesting results, building a foundation for further research projects. For example, we isolated a naturally-occurring bacterium from surface-sterilized switchgrass seeds, identified as a unique Panteoa agglomerans species, and named strain PaKM. PaKM has been proved to be an efficient growth promoter of switchgrass over a broad spectrum of genotypes and has potential in applications with low input and sustainable production systems on marginal lands. In collaboration with Dr. Shuijin Hu (North Carolina State University), we conducted experiments on how endophyte-inoculated switchgrass affects soil N and P availability and the number of AMF in roots. Our preliminary results showed that PsJN increased AMF infection of switchgrass roots, and enhanced soil N availability and soil N mineralization on a low nutrient field. Further study of this phenomenon on different soils, over longer time periods, is needed to assess its potential impact on the productivity and longevity of switchgrass stands.

Targeted discovery of glycoside hydrolases from a switchgrass-adapted compost community

Energy Technology Data Exchange (ETDEWEB)

Allgaier, M.; Reddy, A.; Park, J. I.; Ivanova, N.; D' haeseleer, P.; Lowry, S.; Sapra, R.; Hazen, T.C.; Simmons, B.A.; VanderGheynst, J. S.; Hugenholtz, P.

2009-11-15

Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Small-subunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, {approx}10% were putative cellulases mostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50 C and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.

Targeted Discovery of Glycoside Hydrolases from a Switchgrass-Adapted Compost Community

Energy Technology Data Exchange (ETDEWEB)

Reddy, Amitha; Allgaier, Martin; Park, Joshua I.; Ivanoval, Natalia; Dhaeseleer, Patrik; Lowry, Steve; Sapra, Rajat; Hazen, Terry C.; Simmons, Blake A.; VanderGheynst, Jean S.; Hugenholtz, Philip

2011-05-11

Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Smallsubunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, ,10percent were putative cellulasesmostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50uC and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.

Global Simulation of Bioenergy Crop Productivity: Analytical Framework and Case Study for Switchgrass

Energy Technology Data Exchange (ETDEWEB)

Kang, Shujiang [ORNL; Kline, Keith L [ORNL; Nair, S. Surendran [University of Tennessee, Knoxville (UTK); Nichols, Dr Jeff A [ORNL; Post, Wilfred M [ORNL; Brandt, Craig C [ORNL; Wullschleger, Stan D [ORNL; Wei, Yaxing [ORNL; Singh, Nagendra [ORNL

2013-01-01

A global energy crop productivity model that provides geospatially explicit quantitative details on biomass potential and factors affecting sustainability would be useful, but does not exist now. This study describes a modeling platform capable of meeting many challenges associated with global-scale agro-ecosystem modeling. We designed an analytical framework for bioenergy crops consisting of six major components: (i) standardized natural resources datasets, (ii) global field-trial data and crop management practices, (iii) simulation units and management scenarios, (iv) model calibration and validation, (v) high-performance computing (HPC) simulation, and (vi) simulation output processing and analysis. The HPC-Environmental Policy Integrated Climate (HPC-EPIC) model simulated a perennial bioenergy crop, switchgrass (Panicum virgatum L.), estimating feedstock production potentials and effects across the globe. This modeling platform can assess soil C sequestration, net greenhouse gas (GHG) emissions, nonpoint source pollution (e.g., nutrient and pesticide loss), and energy exchange with the atmosphere. It can be expanded to include additional bioenergy crops (e.g., miscanthus, energy cane, and agave) and food crops under different management scenarios. The platform and switchgrass field-trial dataset are available to support global analysis of biomass feedstock production potential and corresponding metrics of sustainability.

MicroRNA expression analysis in the cellulosic biofuel crop switchgrass (Panicum virgatum under abiotic stress.

Directory of Open Access Journals (Sweden)

Guiling Sun

Full Text Available Switchgrass has increasingly been recognized as a dedicated biofuel crop for its broad adaptation to marginal lands and high biomass. However, little is known about the basic biology and the regulatory mechanisms of gene expression in switchgrass, particularly under stress conditions. In this study, we investigated the effect of salt and drought stress on switchgrass germination, growth and the expression of small regulatory RNAs. The results indicate that salt stress had a gradual but significant negative effect on switchgrass growth and development. The germination rate was significantly decreased from 82% for control to 36% under 1% NaCl treatment. However, drought stress had little effect on the germination rate but had a significant effect on the growth of switchgrass under the severest salinity stress. Both salt and drought stresses altered the expression pattern of miRNAs in a dose-dependent manner. However, each miRNA responded to drought stress in a different pattern. Salt and drought stress changed the expression level of miRNAs mainly from 0.9-fold up-regulation to 0.7-fold down-regulation. miRNAs were less sensitive to drought treatment than salinity treatment, as evidenced by the narrow fold change in expression levels. Although the range of change in expression level of miRNAs was similar under salt and drought stress, no miRNAs displayed significant change in expression level under all tested salt conditions. Two miRNAs, miR156 and miR162, showed significantly change in expression level under high drought stress. This suggests that miR156 and miR162 may attribute to the adaption of switchgrass to drought stress and are good candidates for improving switchgrass as a biofuel crop by transgenic technology.

31 CFR 515.321 - United States; continental United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory of...

31 CFR 500.321 - United States; continental United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 500.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including U.S. trust territories...

31 CFR 535.321 - United States; continental United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory of...

Impact of switching production to bioenergy crops: the switchgrass example

Energy Technology Data Exchange (ETDEWEB)

McDonald, S. [Sheffield Univ. (United Kingdom); Robinson, S. [Sussex Univ., Brighton (United Kingdom); Thierfelder, K. [U.S. Naval Academy (United States)

2006-03-15

This paper reports the results from simulations that evaluate the general equilibrium effects of substituting switchgrass, a biomass, for crude oil in USA petroleum production. The new production process is less efficient and USA GDP declines slightly. As switchgrass production expands, USA agriculture contracts and the world price of cereals increases. The world price of crude oil falls as USA import demand declines. The net effect of the price and income changes is a general decline in economic welfare. Moreover, the declines in welfare are proportionately greater for developing countries who produce small quantities of agricultural commodities whose prices increase. (author)

Model evaluation of plant metal content and biomass yield for the phytoextraction of heavy metals by switchgrass.

Science.gov (United States)

Chen, Bo-Ching; Lai, Hung-Yu; Juang, Kai-Wei

2012-06-01

To better understand the ability of switchgrass (Panicum virgatum L.), a perennial grass often relegated to marginal agricultural areas with minimal inputs, to remove cadmium, chromium, and zinc by phytoextraction from contaminated sites, the relationship between plant metal content and biomass yield is expressed in different models to predict the amount of metals switchgrass can extract. These models are reliable in assessing the use of switchgrass for phytoremediation of heavy-metal-contaminated sites. In the present study, linear and exponential decay models are more suitable for presenting the relationship between plant cadmium and dry weight. The maximum extractions of cadmium using switchgrass, as predicted by the linear and exponential decay models, approached 40 and 34 μg pot(-1), respectively. The log normal model was superior in predicting the relationship between plant chromium and dry weight. The predicted maximum extraction of chromium by switchgrass was about 56 μg pot(-1). In addition, the exponential decay and log normal models were better than the linear model in predicting the relationship between plant zinc and dry weight. The maximum extractions of zinc by switchgrass, as predicted by the exponential decay and log normal models, were about 358 and 254 μg pot(-1), respectively. To meet the maximum removal of Cd, Cr, and Zn, one can adopt the optimal timing of harvest as plant Cd, Cr, and Zn approach 450 and 526 mg kg(-1), 266 mg kg(-1), and 3022 and 5000 mg kg(-1), respectively. Due to the well-known agronomic characteristics of cultivation and the high biomass production of switchgrass, it is practicable to use switchgrass for the phytoextraction of heavy metals in situ. Copyright © 2012 Elsevier Inc. All rights reserved.

Switchgrass (Panicum virgatum L. Genotypes Differ between Coastal Sites and Inland Road Corridors in the Northeastern US.

Directory of Open Access Journals (Sweden)

Geoffrey Ecker

Full Text Available Switchgrass (Panicum virgatum L. is a North American grass that exhibits vast genetic diversity across its geographic range. In the Northeastern US, local switchgrass populations were restricted to a narrow coastal zone before European settlement, but current populations inhabit inland road verges raising questions about their origin and genetics. These questions are important because switchgrass lines with novel traits are being cultivated as a biofuel feedstock, and gene flow could impact the genetic integrity and distribution of local populations. This study was designed to determine if: 1 switchgrass plants collected in the Long Island Sound Coastal Lowland coastal Level IV ecoregion represented local populations, and 2 switchgrass plants collected from road verges in the adjacent inland regions were most closely related to local coastal populations or switchgrass from other geographic regions. The study used 18 microsatellite markers to infer the genetic relationships between 122 collected switchgrass plants and a reference dataset consisting of 28 cultivars representing ecotypes, ploidy levels, and lineages from North America. Results showed that 84% of 88 plants collected in the coastal plants were most closely aligned with the Lowland tetraploid genetic pool. Among this group, 61 coastal plants were similar to, but distinct from, all Lowland tetraploid cultivars in the reference dataset leading to the designation of a genetic sub-population called the Southern New England Lowland Tetraploids. In contrast, 67% of 34 plants collected in road verges in the inland ecoregions were most similar to two Upland octoploid cultivars; only 24% of roadside plants were Lowland tetraploid. These results suggest that cryptic, non-local genotypes exist in road verges and that gene flow from biofuels plantations could contribute to further changes in switchgrass population genetics in the Northeast.

Determining switchgrass biomass supplies for cellulosic biorefineries

Science.gov (United States)

Switchgrass (Panicum virgatum L.) is being developed into a bioenergy crop for use in temperate regions of the USA. Information on spatial and temporial variation for stands and biomass yield among and within fields in large agroecoregions is not available. A reliable feedstock supply will be essent...

Simulated biomass, environmental impacts and best management practices for long-term switchgrass systems in a semi-arid region

International Nuclear Information System (INIS)

Wang, Limei; Qian, Yaling; Brummer, Joe E.; Zheng, Jiyong; Wilhelm, Sarah; Parton, William J.

2015-01-01

Long-term information on switchgrass (Panicum virgatum L.) as a biomass energy crop grown on marginally saline soil and the associated impacts on soil carbon (C) and nitrogen (N) dynamics, greenhouse gas (GHG) emissions, and best management practices (BMPs) are limited. In this study, we employed the DAYCENT model, based on a 4-year switchgrass field experiment, to evaluate the long-term biomass yield potential and environmental impacts, and further to develop BMPs for switchgrass in a semi-arid region. The model showed that long-term (14-year) annual mean biomass yields were 9.6 and 5.2 Mg ha −1 for irrigated and rainfed switchgrass systems, respectively. The simulated biomass yields correlated well with field-measured biomass with r 2 values of 0.99 and 0.89 for irrigated and rainfed systems, respectively. Soil organic carbon (SOC) and soil total nitrogen (STN) accumulated rapidly after switchgrass establishment, with mean accrual rates of 0.99–1.13 Mg C ha −1  yr −1 and 0.04–0.08 Mg N ha −1  yr −1 , respectively. Based on the outputs of numerous long-term model simulations with variable irrigation water supplies and N rates, the irrigation regime and N rate with the highest yield to input ratio were chosen as BMPs. The DAYCENT model predicted-BMP was irrigating every 14 days at 70% potential evapotranspiration combined with an N rate of 67 kg ha −1  yr −1 . Switchgrass established and produced biomass reasonably well in this semi-arid region; however, appropriate irrigation and N fertilization were needed for optimal biomass yield. Switchgrass had a great potential to sequester C into soils with low N 2 O emissions while supplying significant quantities of biomass for biofuel synthesis. - Highlights: • The DAYCENT model reliably simulated the growth of switchgrass on marginal land. • Long-term biomass and environmental impacts were simulated using the DAYCENT model. • Switchgrass produced biomass well on marginal land, but

Targeted discovery of glycoside hydrolases from a switchgrass-adapted compost community.

Directory of Open Access Journals (Sweden)

Martin Allgaier

Full Text Available Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Small-subunit (SSU rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, approximately 10% were putative cellulases mostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50 degrees C and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.

Transcriptional and physiological data reveal the dehydration memory behavior in switchgrass (Panicum virgatum L.).

Science.gov (United States)

Zhang, Chao; Peng, Xi; Guo, Xiaofeng; Tang, Gaijuan; Sun, Fengli; Liu, Shudong; Xi, Yajun

2018-01-01

Switchgrass ( Panicum virgatum L.) is a model biofuel plant because of its high biomass, cellulose-richness, easy degradation to ethanol, and the availability of extensive genomic information. However, a little is currently known about the molecular responses of switchgrass plants to dehydration stress, especially multiple dehydration stresses. Studies on the transcriptional profiles of 35-day-old tissue culture plants revealed 741 dehydration memory genes. Gene Ontology and pathway analysis showed that these genes were enriched in phenylpropanoid biosynthesis, starch and sucrose metabolism, and plant hormone signal transduction. Further analysis of specific pathways combined with physiological data suggested that switchgrass improved its dehydration resistance by changing various aspects of its responses to secondary dehydration stress (D2), including the regulation of abscisic acid (ABA) and jasmonic acid (JA) biosynthesis and signal transduction, the biosynthesis of osmolytes (l-proline, stachyose and trehalose), energy metabolism (i.e., metabolic process relating to photosynthetic systems, glycolysis, and the TCA cycle), and lignin biosynthesis. The transcriptional data and chemical substance assays showed that ABA was significantly accumulated during both primary (D1) and secondary (D2) dehydration stresses, whereas JA accumulated during D1 but became significantly less abundant during D2. This suggests the existence of a complicated signaling network of plant hormones in response to repeated dehydration stresses. A homology analysis focusing on switchgrass, maize, and Arabidopsis revealed the conservation and species-specific distribution of dehydration memory genes. The molecular responses of switchgrass plants to successive dehydration stresses have been systematically characterized, revealing a previously unknown transcriptional memory behavior. These results provide new insights into the mechanisms of dehydration stress responses in plants. The genes and

Comparison of Chemical Composition and Energy Property of Torrefied Switchgrass and Corn Stover

Energy Technology Data Exchange (ETDEWEB)

Tumuluru, Jaya Shankar, E-mail: jayashankar.tumuluru@inl.gov [Idaho National Laboratory, Idaho Falls, ID (United States)

2015-11-30

In the present study, 6-mm ground corn stover and switchgrass were torrefied in temperatures ranging from 180 to 270°C for 15- to 120-min residence time. Thermogravimetric analyzer was used to do the torrefaction studies. At a torrefaction temperature of 270°C and a 30-min residence time, the weight loss increased to >45%. At 180°C and 120 min, there was about 56 and 73% of moisture loss in the corn stover and switchgrass; further increasing the temperature to 270°C and 120 min resulted in about 78.8–88.18% moisture loss in both the feedstock. Additionally, at these temperatures, there was a significant decrease in the volatile content and increase in the fixed carbon content, and the ash content for both the biomasses tested. The ultimate composition like carbon content increased and hydrogen content decreased with increase in the torrefaction temperature and time. At 270°C and 120-min residence time, the carbon content observed was 56.63 and 58.04% and hydrogen content observed was 2.74 and 3.14%. Nitrogen and sulfur content measured at 270°C and 120 min were 0.98, 0.8, 0.076, and 0.07% for both the corn stover and switchgrass. The hydrogen/carbon and oxygen/carbon ratios calculated decreased to the lowest values of 0.59 and 0.64, and 0.71 and 0.76 for both biomasses. The van Krevelen diagram drawn for corn stover and switchgrass torrefied at 270°C indicated that H/C and O/C values are closer to coals like Illinois Basis and Powder River Basin. In the present study, the maximum higher heating value that was observed by corn stover and switchgrass was 21.51 and 21.53 MJ/kg at 270°C and a 120-min residence time. From these results, it can be concluded that corn stover and switchgrass, after torrefaction, shows consistent proximate, ultimate, and energy properties.

Comparison of Chemical Composition and Energy Property of Torrefied Switchgrass and Corn Stover

International Nuclear Information System (INIS)

Tumuluru, Jaya Shankar

2015-01-01

In the present study, 6-mm ground corn stover and switchgrass were torrefied in temperatures ranging from 180 to 270°C for 15- to 120-min residence time. Thermogravimetric analyzer was used to do the torrefaction studies. At a torrefaction temperature of 270°C and a 30-min residence time, the weight loss increased to >45%. At 180°C and 120 min, there was about 56 and 73% of moisture loss in the corn stover and switchgrass; further increasing the temperature to 270°C and 120 min resulted in about 78.8–88.18% moisture loss in both the feedstock. Additionally, at these temperatures, there was a significant decrease in the volatile content and increase in the fixed carbon content, and the ash content for both the biomasses tested. The ultimate composition like carbon content increased and hydrogen content decreased with increase in the torrefaction temperature and time. At 270°C and 120-min residence time, the carbon content observed was 56.63 and 58.04% and hydrogen content observed was 2.74 and 3.14%. Nitrogen and sulfur content measured at 270°C and 120 min were 0.98, 0.8, 0.076, and 0.07% for both the corn stover and switchgrass. The hydrogen/carbon and oxygen/carbon ratios calculated decreased to the lowest values of 0.59 and 0.64, and 0.71 and 0.76 for both biomasses. The van Krevelen diagram drawn for corn stover and switchgrass torrefied at 270°C indicated that H/C and O/C values are closer to coals like Illinois Basis and Powder River Basin. In the present study, the maximum higher heating value that was observed by corn stover and switchgrass was 21.51 and 21.53 MJ/kg at 270°C and a 120-min residence time. From these results, it can be concluded that corn stover and switchgrass, after torrefaction, shows consistent proximate, ultimate, and energy properties.

Rapanos v. United States & Carabell v. United States

Science.gov (United States)

Documents associated with guidance for implementing the definition of waters of the United States under the Clean Water Act following the Rapanos v. United States, and Carabell v. United States Supreme Court decision.

Impact of mechanical, chemical and enzymatic pre-treatments on the methane yield from the anaerobic digestion of switchgrass

International Nuclear Information System (INIS)

Frigon, Jean-Claude; Mehta, Punita; Guiot, Serge R.

2012-01-01

The conversion of cellulosic crops into biofuels, including methane, is receiving a lot of attention lately. Panicum vergatum, or switchgrass, is a warm season perennial grass well adapted to grow in North America. Different pre-treatments were tested in 0.5 l batch reactors, at 35 °C, in order to enhance the methane production from switchgrass, including temperature, sonication, alkalinization and autoclaving. The methane production on the basis of volatile solids (VS) added to the fermentation were 112.4 ± 8.4, 132.5 ± 9.7 and 139.8 ml g −1 after 38 days of incubation for winter harvested switchgrass (WHS) after grinding, grinding with alkalinization, and grinding with alkalinization and autoclaving, respectively. The methane production was higher for fresh summer harvested switchgrass (SHS), with a production of 256.6 ± 8.2 ml g −1 VS after mulching, alkalinization and autoclaving. The methane production from SHS was improved by 29 and 42% when applying lignin (LiP) or manganese peroxidase (MnP), at 202.1 ± 9.8 and 222.9 ± 22.5 ml g −1 VS, respectively. The combination of an alkali pre-treatment with the MnP increased the methane production furthermore at 297.7 ml g −1 VS. The use of pectinases without chemical pre-treatment showed promising yields at 287.4 and 239.5 ml g −1 VS for pectate-lyase and poly-galacturonase, respectively. An estimation of the methane yield per hectare of crop harvested resulted in net energy production of 29.8, 49.7 and 78.1 GJ for winter harvested switchgrass, mulched and pretreated summer harvested switchgrass, respectively. Switchgrass represents an interesting candidate as a lignocellulosic crop for methane production. -- Highlights: ► Switchgrass is a model energy crops for biofuels production. ► This study evaluated different pre-treatments to enhance methane production. ► Pre-treatments increase significantly the methane produced from switchgrass. ► Enzymatic pre-treatments were superior to physical and

Physiological Evaluation of Alkali-Salt Tolerance of Thirty Switchgrass (Panicum virgatum Lines.

Directory of Open Access Journals (Sweden)

Guofu Hu

Full Text Available Soil salt-alkalization is a major limiting factor for crop production in many regions. Switchgrass (Panicum virgatum L. is a warm-season C4 perennial rhizomatous bunchgrass and a target lignocellulosic biofuel species. The objective of this study was to evaluate relative alkali-salt tolerance among 30 switchgrass lines. Tillers of each switchgrass line were transplanted into pots filled with fine sand. Two months after transplanting, plants at E5 developmental stage were grown in either half strength Hoagland's nutrient solution with 0 mM Na+ (control or half strength Hoagland's nutrient solution with 150 mM Na+ and pH of 9.5 (alkali-salt stress treatment for 20 d. Alkali-salt stress damaged cell membranes [higher electrolyte leakage (EL], reduced leaf relative water content (RWC, net photosynthetic rate (Pn, stomatal conductance (gs, and transpiration rate (Tr. An alkali-salt stress tolerance trait index (ASTTI for each parameter was calculated based on the ratio of the value under alkali-salt stress and the value under non-stress conditions for each parameter of each line. Relative alkali-salt tolerance was determined based on principal components analysis and cluster analysis of the physiological parameters and their ASTTI values. Significant differences in alkali-salt stress tolerance were found among the 30 lines. Lowland lines TEM-SEC, Alamo, TEM-SLC and Kanlow were classified as alkali-salt tolerant. In contrast, three lowland lines (AM-314/MS-155, BN-13645-64 and two upland lines (Caddo and Blackwell-1 were classified as alkali-salt sensitive. The results suggest wide variations exist in alkali-salt stress tolerance among the 30 switchgrass lines. The approach of using a combination of principal components and cluster analysis of the physiological parameters and related ASTTI is feasible for evaluating alkali-salt tolerance in switchgrass.

Physiological Evaluation of Alkali-Salt Tolerance of Thirty Switchgrass (Panicum virgatum) Lines.

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Hu, Guofu; Liu, Yiming; Zhang, Xunzhong; Yao, Fengjiao; Huang, Yan; Ervin, Erik H; Zhao, Bingyu

2015-01-01

Soil salt-alkalization is a major limiting factor for crop production in many regions. Switchgrass (Panicum virgatum L.) is a warm-season C4 perennial rhizomatous bunchgrass and a target lignocellulosic biofuel species. The objective of this study was to evaluate relative alkali-salt tolerance among 30 switchgrass lines. Tillers of each switchgrass line were transplanted into pots filled with fine sand. Two months after transplanting, plants at E5 developmental stage were grown in either half strength Hoagland's nutrient solution with 0 mM Na+ (control) or half strength Hoagland's nutrient solution with 150 mM Na+ and pH of 9.5 (alkali-salt stress treatment) for 20 d. Alkali-salt stress damaged cell membranes [higher electrolyte leakage (EL)], reduced leaf relative water content (RWC), net photosynthetic rate (Pn), stomatal conductance (gs), and transpiration rate (Tr). An alkali-salt stress tolerance trait index (ASTTI) for each parameter was calculated based on the ratio of the value under alkali-salt stress and the value under non-stress conditions for each parameter of each line. Relative alkali-salt tolerance was determined based on principal components analysis and cluster analysis of the physiological parameters and their ASTTI values. Significant differences in alkali-salt stress tolerance were found among the 30 lines. Lowland lines TEM-SEC, Alamo, TEM-SLC and Kanlow were classified as alkali-salt tolerant. In contrast, three lowland lines (AM-314/MS-155, BN-13645-64) and two upland lines (Caddo and Blackwell-1) were classified as alkali-salt sensitive. The results suggest wide variations exist in alkali-salt stress tolerance among the 30 switchgrass lines. The approach of using a combination of principal components and cluster analysis of the physiological parameters and related ASTTI is feasible for evaluating alkali-salt tolerance in switchgrass.

Extended light exposure increases stem digestibility and biomass production of switchgrass

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Zhao, Chunqiao; Hou, Xincun; Zhu, Yi; Yue, Yuesen; Wu, Juying

2017-01-01

Switchgrass is a photoperiod-sensitive energy grass suitable for growing in the marginal lands of China. We explored the effects of extended photoperiods of low-irradiance light (7 μmol·m-2·s-1, no effective photosynthesis) on the growth, the biomass dry weight, the biomass allocation, and, especially, the stem digestibility and cell wall characteristics of switchgrass. Two extended photoperiods (i.e., 18 and 24 h) were applied over Alamo. Extended light exposure (18 and 24 h) resulted in delayed heading and higher dry weights of vegetative organs (by 32.87 and 35.94%, respectively) at the expense of reducing the amount of sexual organs (by 40.05 and 50.87%, respectively). Compared to the control group (i.e., natural photoperiod), the yield of hexoses (% dry matter) in the stems after a direct enzymatic hydrolysis (DEH) treatment significantly increased (by 44.02 and 46.10%) for those groups irradiated during 18 and 24 h, respectively. Moreover, the yield of hexoses obtained via enzymatic hydrolysis increased after both basic (1% NaOH) and acid (1% H2SO4) pretreatments for the groups irradiated during 18 and 24 h. Additionally, low-irradiance light extension (LILE) significantly increased the content of non-structural carbohydrates (NSCs) while notably reducing the lignin content and the syringyl to guaiacyl (S/G) ratio. These structural changes were in part responsible for the observed improved stem digestibility. Remarkably, LILE significantly decreased the cellulose crystallinity index (CrI) of switchgrass by significantly increasing both the arabinose substitution degree in xylan and the content of ammonium oxalate-extractable uronic acids, both favoring cellulose digestibility. Despite this LILE technology is not applied to the cultivation of switchgrass on a large scale yet, we believe that the present work is important in that it reveals important relationships between extended day length irradiations and biomass production and quality. Additionally, this

Economics of switchgrass and miscanthus relative to coal as feedstock for generating electricity

International Nuclear Information System (INIS)

Aravindhakshan, Sijesh C.; Epplin, Francis M.; Taliaferro, Charles M.

2010-01-01

Switchgrass (Panicum virgatum) serves as a model dedicated energy crop in the U.S.A. Miscanthus (Miscanthus x giganteus) has served a similar role in Europe. This study was conducted to determine the most economical species, harvest frequency, and carbon tax required for either of the two candidate feedstocks to be an economically viable alternative for cofiring with coal for electricity generation. Biomass yield and energy content data were obtained from a field experiment conducted near Stillwater, Oklahoma, U.S.A., in which both grasses were established in 2002. Plots were split to enable two harvest treatments (once and twice yr -1 ). The switchgrass variety 'Alamo', with a single annual post-senescence harvest, produced more biomass (15.87 Mg ha -1 yr -1 ) than miscanthus (12.39 Mg ha -1 yr -1 ) and more energy (249.6 million kJ ha -1 yr -1 versus 199.7 million kJ ha -1 yr -1 for miscanthus). For the average yields obtained, the estimated cost to produce and deliver biomass an average distance of 50 km was $43.9 Mg -1 for switchgrass and $51.7 Mg -1 for miscanthus. Given a delivered coal price of $39.76 Mg -1 and average energy content, a carbon tax of $7 Mg -1 CO 2 would be required for switchgrass to be economically competitive. For the location and the environmental conditions that prevailed during the experiment, switchgrass with one harvest per year produced greater yields at a lower cost than miscanthus. In the absence of government intervention such as requiring biomass use or instituting a carbon tax, biomass is not an economically competitive feedstock for electricity generation in the region studied. (author)

Global Simulation of Bioenergy Crop Productivity: Analytical framework and Case Study for Switchgrass

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Nair, S. Surendran [University of Tennessee, Knoxville (UTK); Nichols, Jeff A. {Cyber Sciences} [ORNL; Post, Wilfred M [ORNL; Wang, Dali [ORNL; Wullschleger, Stan D [ORNL; Kline, Keith L [ORNL; Wei, Yaxing [ORNL; Singh, Nagendra [ORNL; Kang, Shujiang [ORNL

2014-01-01

Contemporary global assessments of the deployment potential and sustainability aspects of biofuel crops lack quantitative details. This paper describes an analytical framework capable of meeting the challenges associated with global scale agro-ecosystem modeling. We designed a modeling platform for bioenergy crops, consisting of five major components: (i) standardized global natural resources and management data sets, (ii) global simulation unit and management scenarios, (iii) model calibration and validation, (iv) high-performance computing (HPC) modeling, and (v) simulation output processing and analysis. A case study with the HPC- Environmental Policy Integrated Climate model (HPC-EPIC) to simulate a perennial bioenergy crop, switchgrass (Panicum virgatum L.) and global biomass feedstock analysis on grassland demonstrates the application of this platform. The results illustrate biomass feedstock variability of switchgrass and provide insights on how the modeling platform can be expanded to better assess sustainable production criteria and other biomass crops. Feedstock potentials on global grasslands and within different countries are also shown. Future efforts involve developing databases of productivity, implementing global simulations for other bioenergy crops (e.g. miscanthus, energycane and agave), and assessing environmental impacts under various management regimes. We anticipated this platform will provide an exemplary tool and assessment data for international communities to conduct global analysis of biofuel biomass feedstocks and sustainability.

RNA-seq analysis of overexpressing ovine AANAT gene of melatonin biosynthesis in switchgrass

Directory of Open Access Journals (Sweden)

Shan Yuan

2016-08-01

Full Text Available Melatonin serves important functions in the promotion of growth and anti-stress regulation by efficient radical scavenging and regulation of antioxidant enzyme activity in various plants. To investigate its regulatory roles and metabolism pathways, the transcriptomic profile of overexpressing the ovine arylalkylamine N-acetyltransferase (oAANAT gene, encoding the penultimate enzyme in melatonin biosynthesis, was compared with empty vector (EV control using RNA-seq in switchgrass, a model plant of cellulosic ethanol conversion. The 85.22 million high quality reads that were assembled into 135,684 unigenes were generated by Illumina sequencing for transgenic oAANAT switchgrass with an average sequence length of 716 bp. A total of 946 differential expression genes (DEGs in transgenic line comparing to control switchgrass, including 737 up-regulated and 209 down-regulated genes, were mainly enriched with two main functional patterns of melatonin identifying by gene ontology analysis: the growth regulator and stress tolerance. Furthermore, KEGG maps indicated that the biosynthetic pathways of secondary metabolite (phenylpropanoids, flavonoids, steroids, stilbenoid, diarylheptanoid and gingerol and signaling pathways (MAPK signaling pathway, estrogen signaling pathway were involved in melatonin metabolism. This study substantially expands the transcriptome information for switchgrass and provides valuable clues for identifying candidate genes involved in melatonin biosynthesis and elucidating the mechanism of melatonin metabolism.

ASSESSING OF HERBIVOROUS AND BENEFICIAL INSECTS ON SWITCHGRASS IN UKRAINE.

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Stefanovska, T; Kucherovska, S; Pisdlisnyuk, V

2014-01-01

A perennial switchgrass, (Panicum virgatum L.), (C4) that is native to North America has good potential for biomass production because of its wide geographic distribution and adaptability to diverse environmental conditions. Insects can significantly impact the yield and quality of biofuel crops. If switchgrass are to be grown on marginally arable land or in monoculture, it are likely to be plagued with herbivore pests and plant diseases at a rate that exceeds what would be expected if the plants were not stressed in this manner. This biofuel crop has been under evaluation for commercial growing in Ukraine for eight years. However, insect diversity and the potential impact of pests on biomass production of this feedstock have not been accessed yet. The objective of our study, started in 2011, is a survey of switch grass insects by trophic groups and determine species that have pest status at two sites in the Central part of Ukraine (Kiev and Poltava regions). In Poltava site we investigated the effect of nine varieties of switchgrass (lowland and upland) to insects' diversity. We assessed changes over time in the densities of major insects' trophic groups, identifying potential pests and natural enemies. Obtained results indicates that different life stages of herbivorous insects from Hymenoptera, Homoptera, Diptera and Coleoptera orders were present on switchgrass during the growing season. Our study results suggests that choice of variety has an impact on trophic groups' structure and number of insects from different orders on swicthgrass. Herbivores and beneficial insects were the only groups that showed significant differences across sampling dates. The highest population of herbivores insects we recorded on 'Alamo' variety for studied years, although herbivore diversity tended to increase on 'Shelter', 'Alamo' and 'Cave-in-Rock' during 2012 and 2013. 'Dacotah', 'Nebraska', 'Sunburst', 'Forestburg' and 'Carthage' showed the highest level of beneficial insects

Historical Perspective on How and Why Switchgrass was Seleced as a "Model" High-Potential Energy Crop

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Wright, Lynn [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2007-07-01

Economic and environmental assessments by Oak Ridge National Laboratory’s Biofuels Feedstock Development Program staff together with the screening project results, and funding limitations lead to making the decision to further develop only switchgrass as a “model” or “prototype” species in about 1990. This paper describes the conditions under which the herbaceous species were screened, summarizes results from those trials, discusses the various factors which influenced the selection of switchgrass, and provides a brief evaluation of switchgrass with respect to criteria that should be considered when selecting and developing a crop for biofuels and bioproducts.

In-field direct combustion fuel property changes of switchgrass harvested from summer to fall

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Ogden, C.A.; Ileleji, K.E. [Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN (United States); Johnson, K.D. [Department of Agronomy, Purdue University, West Lafayette, IN (United States); Wang, Q. [State Key Laboratory for Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 (China)

2010-03-15

Switchgrass, a perennial warm-season grass and potential energy crop, is usually harvested during the time between full maturity in the fall to the following spring. During this wide harvest window, the changes in fuel properties that could occur are important for making appropriate decisions with respect to the optimum harvest time for maximum fuel quality. A field plot study was carried out to investigate the quantitative fuel properties (proximate, ultimate and mineral analyses) of switchgrass over a harvest period from crop maturity in July through November. Harvest moisture decreased from July to November and moisture was uniformly distributed in the switchgrass plant at all times in the harvest period. There were significant differences in ash, volatiles, fixed carbon and nitrogen among months of harvest. Nitrogen, ash and fixed carbon contents decreased while oxygen and volatiles increased through the harvest period. Also, there were significant differences in oxides of silicon, calcium, potassium, phosphorus and sulfur among harvest times. The concentration of oxides of potassium and sulfur decreased at the end of the harvesting period. Fouling and slagging indices decreased as harvest was delayed but remained low throughout harvest. However, the decreases are small and might not dramatically impact fouling and slagging. Overall, the results appear to favor a later harvest for switchgrass used for direct combustion. This study will benefit feedstock producers as well as biomass feedstock facility operators by providing a better understanding of how the properties of switchgrass vary over a typical harvest period and their potential effect on boiler equipment. (author)

Glycoside hydrolase activities of thermophilic bacterial consortia adapted to switchgrass.

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Gladden, John M; Allgaier, Martin; Miller, Christopher S; Hazen, Terry C; VanderGheynst, Jean S; Hugenholtz, Philip; Simmons, Blake A; Singer, Steven W

2011-08-15

Industrial-scale biofuel production requires robust enzymatic cocktails to produce fermentable sugars from lignocellulosic biomass. Thermophilic bacterial consortia are a potential source of cellulases and hemicellulases adapted to harsher reaction conditions than commercial fungal enzymes. Compost-derived microbial consortia were adapted to switchgrass at 60°C to develop thermophilic biomass-degrading consortia for detailed studies. Microbial community analysis using small-subunit rRNA gene amplicon pyrosequencing and short-read metagenomic sequencing demonstrated that thermophilic adaptation to switchgrass resulted in low-diversity bacterial consortia with a high abundance of bacteria related to thermophilic paenibacilli, Rhodothermus marinus, and Thermus thermophilus. At lower abundance, thermophilic Chloroflexi and an uncultivated lineage of the Gemmatimonadetes phylum were observed. Supernatants isolated from these consortia had high levels of xylanase and endoglucanase activities. Compared to commercial enzyme preparations, the endoglucanase enzymes had a higher thermotolerance and were more stable in the presence of 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), an ionic liquid used for biomass pretreatment. The supernatants were used to saccharify [C2mim][OAc]-pretreated switchgrass at elevated temperatures (up to 80°C), demonstrating that these consortia are an excellent source of enzymes for the development of enzymatic cocktails tailored to more extreme reaction conditions.

Responses of switchgrass to precipitation changes: Nonlinear and asymmetric?

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Background/Question/Methods: Climate changes, including chronic changes in precipitation amounts, will influence plant physiology, biomass and productivity, and soil respiration. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. Two preci...

Extraction and characterization of triglycerides from coffeeweed and switchgrass seeds as potential feedstocks for biodiesel production.

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Armah-Agyeman, Grace; Gyamerah, Michael; Biney, Paul O; Woldesenbet, Selamawit

2016-10-01

Although switchgrass has been developed as a biofuel feedstock and its potential for bioethanol and bio-oil from fast pyrolysis reported in the literature, the use of the seeds of switchgrass as a source of triglycerides for biodiesel production has not been reported. Similarly, the potential for extracting triglycerides from coffeeweed (an invasive plant of no current economic value) needs to be investigated to ascertain its potential economic use for biodiesel production. The results show that coffeeweed and switchgrass seeds contain known triglycerides which are 983 and 1000 g kg(-1) respectively of the fatty acids found in edible vegetable oils such as sunflower, corn and soybean oils. In addition, the triglyceride yields of 53-67 g kg(-1) of the seed samples are in the range of commercial oil-producing seeds such as corn (42 g kg(-1) ). The results also indicate that the two non-edible oils could be used as substitutes for edible oil for biodiesel production. In addition, the use of seeds of switchgrass for non-edible oil production (as a feedstock for the production of biodiesel) further increases the total biofuel yield when switchgrass is cultivated for use as energy feedstock for pyrolysis oil and biodiesel production. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Fiber length and pulping characteristics of switchgrass, alfalfa stems, hybrid poplar and willow biomasses.

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Ai, Jun; Tschirner, Ulrike

2010-01-01

Switchgrass (Panicum virgatum), alfalfa stems (Medicago sativa), second year growth hybrid poplar (Populus) and willow (Salix spp.) were examined to determine fiber characteristics, pulping behavior and paper properties. Alfalfa stems and switchgrass both showed length weighted average fiber length (LWW) of 0.78 mm, a very narrow fiber length distribution and high fines content. Willow and hybrid poplar have lower fines content but a very low average fiber length (0.42 and 0.48 mm LWW). In addition, the four biomass species showed distinctly different chemical compositions. Switchgrass was defibered successfully using Soda and Soda Anthraquinone (AQ) pulping and demonstrated good paper properties. Both fast-growing wood species pulped well using the Kraft process, and showed acceptable tensile strength, but low tear strength. Alfalfa stems reacted very poorly to Soda and Soda AQ pulping but responded well to Kraft and Kraft AQ. Pulps with tensile and tear strength considerably higher than those found for commercial aspen pulps were observed for alfalfa. All four biomass species examined demonstrated low pulp yield. The highest yields were obtained with poplar and switchgrass (around 43%). Considering the short fibers and low yields, all four biomass types will likely only be used in paper manufacturing if they offer considerable economic advantage over traditional pulp wood.

Comparison of corn and switchgrass on marginal soils for bioenergy

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Varvel, G.E.; Vogel, K.P.; Mitchell, R.B. [USDA-ARS, 344 Keim Hall, University of Nebraska-Lincoln, P.O. Box 830937, Lincoln, NE 68583-0937 (United States); Follett, R.F. [USDA-ARS, Room S-100, 2150 Centre Avenue Building D, Ft. Collins, CO 80526-8119 (United States); Kimble, J.M. [USDA-NRCS, National Soil Survey Center, 100 Centennial Mall North, Lincoln, NE 68508-3866 (United States)

2008-01-15

Crop residues such as corn (Zea mays L.) stover are viewed as an abundant and inexpensive source of biomass that can be removed from fields to produce bioenergy. Assumptions include that with minimum or no-tillage farming methods, there will be no deleterious production or environmental effects. A long-term field study was established in eastern Nebraska, USA, to compare the switchgrass managed as a biomass energy crop versus no-till corn on a non-irrigated site, marginal for row-crop production, in the western Corn Belt. Our objective in this paper is to report on corn stover removal effects on corn grain yields and potential ethanol production in both cropping systems. Corn, under no-till management, and switchgrass were grown at three N fertilizer levels. In the first 5 years (2001-2005), removal of half the available stover significantly reduced corn yields. During that same time period, the potential ethanol yield for switchgrass was equal to or greater than the potential total ethanol yield of corn grain and harvested stover fertilized at the same optimum N rate. The effect of crop residue removal on crop productivity needs to be investigated in other agro-ecosystems and the potential use of dedicated perennial biomass energy crops should remain a viable renewable energy option on non-irrigated marginal croplands. (author)

Nitrogen fertilization of switchgrass increases biomass yield and improves net greenhouse gas balance in northern Michigan, U.S.A

International Nuclear Information System (INIS)

Nikiema, Paligwende; Rothstein, David E.; Min, Doo-Hong; Kapp, Christian J.

2011-01-01

Nitrogen (N) fertilization can increase bioenergy crop production; however, fertilizer production and application can contribute to greenhouse gas (GHG) emissions, potentially undermining the GHG benefits of bioenergy crops. The objective of this study was to evaluate the effects of N fertilization on GHG emissions and biomass production of switchgrass bioenergy crop, in northern Michigan. Nitrogen fertilization treatments included 0 kg ha -1 (control), 56 kg ha -1 (low) and 112 kg ha -1 (high) of N applied as urea. Soil fluxes of CO 2 , N 2 O and CH 4 were measured every two weeks using static chambers. Indirect GHG emissions associated with field activities, manufacturing and transport of fertilizer and pesticides were derived from the literature. Switchgrass aboveground biomass yield was evaluated at the end of the growing season. Nitrogen fertilization contributed little to soil GHG emissions; relative to the control, there were additional global warming potential of 0.7 Mg ha -1 y -1 and 1.5 Mg ha -1 y -1 as CO 2 equivalents (CO 2 eq), calculated using the IPCC values, in the low and high N fertilization treatments, respectively. However, N fertilization greatly stimulated CO 2 uptake by switchgrass, resulting in 1.5- and 2.5-fold increases in biomass yield in the low and high N fertilization treatments, respectively. Nitrogen amendments improved the net GHG benefits by 2.6 Mg ha -1 y -1 and 9.4 Mg ha -1 y -1 as CO 2 eq relative to the control. Results suggest that N fertilization of switchgrass in this region could reduce (15-50%) the land base needed for bioenergy production and decrease pressure on land for food and forage crop production. -- Highlights: → We examine the effects of N fertilization of switchgrass on GHG emissions. → Effects of N fertilization on biomass production of switchgrass bioenergy crop. → N fertilization contributed little to greenhouse gas emissions. → N fertilization greatly stimulated CO 2 uptake by the switchgrass. → N

Switchgrass as a biofuels crop for the upper Southeast

Energy Technology Data Exchange (ETDEWEB)

Parrish, D.J.; Wolf, D.D. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)

1993-12-31

Switchgrass (Panicum virgatum) has been identified in DOE-sponsored studies as a widely adapted, productive herbaceous candidate for biofuels cropping. It is a perennial that has been planted using no-till procedures, and it appears to have positive effects on the soils in which it grows. We have been looking at this species as a potential fuelcrop (as well as a valuable forage) for several years. In this presentation, we note several {open_quotes}lessons learned{close_quotes} about switchgrass establishment and management as an energy crop. Data include results from recent plantings in the upper Southeast USA and from cutting management studies. Six varieties of switchgrass (Alamo, Cave-in-Rock, Kanlow, Shelter, and two breeder`s lines) varied markedly in the success of their no-till establishment at eight locations across the upper Southeast. Better weed control, which was achieved at later planting dates, seemed to be the key. Yields obtained in the establishment stands revealed that two harvests per season are more productive (by 2 to 3 Mg/ha) than one, but the date of first cutting is crucial. First cutting should be from late-June to mid-July. A two-cut system may not be economically advantageous, however. Another cutting-management study detected losses of standing biomass at the end of the growing season. As much as 15% of the above-ground biomass present in early-September was no longer harvestable in early-November. We think this loss results from translocation of dry matter to below-ground parts.

Bioclimatic predictions of habitat suitability for the biofuel switchgrass in North America under current and future climate scenarios

International Nuclear Information System (INIS)

Barney, Jacob N.; DiTomaso, Joseph M.

2010-01-01

Dedicated biofuel crops, while providing economic and other benefits, may adversely impact biodiversity directly via land use conversion, or indirectly via creation of novel invasive species. To mitigate negative impacts bioclimatic envelope models (BEM) can be used to estimate the potential distribution and suitable habitat based on the climate and distribution in the native range. We used CLIMEX to evaluate the regions of North America suitable for agronomic production, as well as regions potentially susceptible to an invasion of switchgrass (Panicum virgatum) under both current and future climate scenarios. Model results show that >8.7 million km 2 of North America has suitable to very favorable habitat, most of which occurs east of the Rocky Mountains. The non-native range of western North America is largely unsuitable to switchgrass as a crop or potential weed unless irrigation or permanent water is available. Under both the CGCM2 and HadCM3 climate models and A2 and B2 emissions scenarios, an overall increase in suitable habitat is predicted over the coming century, although the western US remains unsuitable. Our results suggest that much of North America is suitable for switchgrass cultivation, although this is likely to shift north in the coming century. Our results also agree with field collections of switchgrass outside its native range, which indicate that switchgrass is unlikely to establish unless it has access to water throughout the year (e.g., along a stream). Thus, it is the potential invasion of switchgrass into riparian habitats in the West that requires further investigation. (author)

Drought-Induced Leaf Proteome Changes in Switchgrass Seedlings

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Zhujia Ye

2016-08-01

Full Text Available Switchgrass (Panicum virgatum is a perennial crop producing deep roots and thus highly tolerant to soil water deficit conditions. However, seedling establishment in the field is very susceptible to prolonged and periodic drought stress. In this study, a “sandwich” system simulating a gradual water deletion process was developed. Switchgrass seedlings were subjected to a 20-day gradual drought treatment process when soil water tension was increased to 0.05 MPa (moderate drought stress and leaf physiological properties had expressed significant alteration. Drought-induced changes in leaf proteomes were identified using the isobaric tags for relative and absolute quantitation (iTRAQ labeling method followed by nano-scale liquid chromatography mass spectrometry (nano-LC-MS/MS analysis. Additionally, total leaf proteins were processed using a combinatorial library of peptide ligands to enrich for lower abundance proteins. Both total proteins and those enriched samples were analyzed to increase the coverage of the quantitative proteomics analysis. A total of 7006 leaf proteins were identified, and 257 (4% of the leaf proteome expressed a significant difference (p < 0.05, fold change <0.6 or >1.7 from the non-treated control to drought-treated conditions. These proteins are involved in the regulation of transcription and translation, cell division, cell wall modification, phyto-hormone metabolism and signaling transduction pathways, and metabolic pathways of carbohydrates, amino acids, and fatty acids. A scheme of abscisic acid (ABA-biosynthesis and ABA responsive signal transduction pathway was reconstructed using these drought-induced significant proteins, showing systemic regulation at protein level to deploy the respective mechanism. Results from this study, in addition to revealing molecular responses to drought stress, provide a large number of proteins (candidate genes that can be employed to improve switchgrass seedling growth and

Accelerating the Switchgrass (Panicum virgatum L.) Breeding Cycle Using Genomic Selection Approaches

Science.gov (United States)

Lipka, Alexander E.; Lu, Fei; Cherney, Jerome H.; Buckler, Edward S.; Casler, Michael D.; Costich, Denise E.

2014-01-01

Switchgrass (Panicum virgatum L.) is a perennial grass undergoing development as a biofuel feedstock. One of the most important factors hindering breeding efforts in this species is the need for accurate measurement of biomass yield on a per-hectare basis. Genomic selection on simple-to-measure traits that approximate biomass yield has the potential to significantly speed up the breeding cycle. Recent advances in switchgrass genomic and phenotypic resources are now making it possible to evaluate the potential of genomic selection of such traits. We leveraged these resources to study the ability of three widely-used genomic selection models to predict phenotypic values of morphological and biomass quality traits in an association panel consisting of predominantly northern adapted upland germplasm. High prediction accuracies were obtained for most of the traits, with standability having the highest ten-fold cross validation prediction accuracy (0.52). Moreover, the morphological traits generally had higher prediction accuracies than the biomass quality traits. Nevertheless, our results suggest that the quality of current genomic and phenotypic resources available for switchgrass is sufficiently high for genomic selection to significantly impact breeding efforts for biomass yield. PMID:25390940

Effect of Removal of Woody Biomass after Clearcutting and Intercropping Switchgrass (Panicum virgatum with Loblolly Pine (Pinus taeda on Rodent Diversity and Populations

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Matthew M. Marshall

2012-01-01

Full Text Available Plant-based feedstocks have long been considered viable, potential sources for biofuels. However, concerns regarding production effects may outweigh gains like carbon savings. Additional information is needed to understand environmental effects of growing feedstocks, including effects on wildlife communities and populations. We used a randomized and replicated experimental design to examine initial effects of biofuel feedstock treatment options, including removal of woody biomass after clearcutting and intercropping switchgrass (Panicum virgatum, on rodents to 2 years post-treatment in regenerating pine plantations in North Carolina, USA. Rodent community composition did not change with switchgrass production or residual biomass removal treatments. Further, residual biomass removal had no influence on rodent population abundances. However, Peromyscus leucopus was found in the greatest abundance and had the greatest survival in treatments without switchgrass. In contrast, abundance of invasive Mus musculus was greatest in switchgrass treatments. Other native species, such as Sigmodon hispidus, were not influenced by the presence of switchgrass. Our results suggest that planting of switchgrass, but not biomass removal, had species-specific effects on rodents at least 2 years post-planting in an intensively managed southern pine system. Determining ecological mechanisms underlying our observed species associations with switchgrass will be integral for understanding long-term sustainability of biofuels production in southern pine forest.

Impact of an innovated storage technology on the quality of preprocessed switchgrass bales

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Christopher N. Boyer

2016-03-01

Full Text Available The purpose of this study was to determine the effects of three particle sizes of feedstock and two types of novel bale wraps on the quality of switchgrass by monitoring the chemical changes in cellulose, hemicellulose, lignin, extractives, and ash over a 225-day period. Using NIR (Near-infrared modeling to predict the chemical composition of the treated biomass, differences were found in cellulose, lignin, and ash content across switchgrass bales with different particle sizes. Enclosing bales in a net and film impacted the cellulose, lignin, and ash content. Cellulose, hemicellulose, lignin, extractives, and ash were different across the 225-day storage period. A quadratic response function made better prediction about cellulose, lignin, and ash response to storage, and a linear response function best described hemicellulose and extractives response to storage. This study yields valuable information regarding the quality of switchgrass at different intervals between the start and end date of storage, which is important to conversion facilities when determining optimal storage strategies to improve quality of the biomass feedstock, based on potential output yield of a bale over time.

Microbial community analysis of switchgrass planted and unplanted soil microcosms displaying PCB dechlorination.

Science.gov (United States)

Liang, Yi; Meggo, Richard; Hu, Dingfei; Schnoor, Jerald L; Mattes, Timothy E

2015-08-01

Polychlorinated biphenyls (PCBs) pose potential risks to human and environmental health because they are carcinogenic, persistent, and bioaccumulative. In this study, we investigated bacterial communities in soil microcosms spiked with PCB 52, 77, and 153. Switchgrass (Panicum virgatum) was employed to improve overall PCB removal, and redox cycling (i.e., sequential periods of flooding followed by periods of no flooding) was performed in an effort to promote PCB dechlorination. Lesser chlorinated PCB transformation products were detected in all microcosms, indicating the occurrence of PCB dechlorination. Terminal restriction fragment length polymorphism (T-RFLP) and clone library analysis showed that PCB spiking, switchgrass planting, and redox cycling affected the microbial community structure. Putative organohalide-respiring Chloroflexi populations, which were not found in unflooded microcosms, were enriched after 2 weeks of flooding in the redox-cycled microcosms. Sequences classified as Geobacter sp. were detected in all microcosms and were most abundant in the switchgrass-planted microcosm spiked with PCB congeners. The presence of possible organohalide-respiring bacteria in these soil microcosms suggests that they play a role in PCB dechlorination therein.

Switchgrass as a fuel stock for electric power generation in Tennessee

International Nuclear Information System (INIS)

Hewitt, W.J.; English, B.C.; Daly, M.; Graham, R.

1997-01-01

This study examined the economic feasibility of switchgrass production and utilization for electric power production in Tennessee. Economic feasibility of switchgrass utilization as a feedstock for electric power generation is related to location of production area, electric facility location, production and transport costs, and harvesting method. Analysis of the feasibility of biomass includes the internalizing of environmental costs of SO 2 and CO 2 into the coal price. A final comparison of the costs of using biomass plus a 12.5 cent/kilowatt hour subsidy is also examined. Finally, the cost savings of a reorganization of harvesting methods is evaluated and the impacts this reorganization might have on the breakeven cost of biomass is compared to the current harvesting methods. (author)

Switchgrass-Based Bioethanol Productivity and Potential Environmental Impact from Marginal Lands in China

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Xun Zhang

2017-02-01

Full Text Available Switchgrass displays an excellent potential to serve as a non-food bioenergy feedstock for bioethanol production in China due to its high potential yield on marginal lands. However, few studies have been conducted on the spatial distribution of switchgrass-based bioethanol production potential in China. This study created a land surface process model (Environmental Policy Integrated Climate GIS (Geographic Information System-based (GEPIC model coupled with a life cycle analysis (LCA to explore the spatial distribution of potential bioethanol production and present a comprehensive analysis of energy efficiency and environmental impacts throughout its whole life cycle. It provides a new approach to study the bioethanol productivity and potential environmental impact from marginal lands based on the high spatial resolution GIS data, and this applies not only to China, but also to other regions and to other types of energy plant. The results indicate that approximately 59 million ha of marginal land in China are suitable for planting switchgrass, and 22 million tons of ethanol can be produced from this land. Additionally, a potential net energy gain (NEG of 1.75 x 106 million MJ will be achieved if all of the marginal land can be used in China, and Yunnan Province offers the most significant one that accounts for 35% of the total. Finally, this study obtained that the total environmental effect index of switchgrass-based bioethanol is the equivalent of a population of approximately 20,300, and a reduction in the global warming potential (GWP is the most significant environmental impact.

Direct measures of mechanical energy for knife mill size reduction of switchgrass, wheat straw, and corn stover.

Science.gov (United States)

Bitra, Venkata S P; Womac, Alvin R; Igathinathane, C; Miu, Petre I; Yang, Yuechuan T; Smith, David R; Chevanan, Nehru; Sokhansanj, Shahab

2009-12-01

Lengthy straw/stalk of biomass may not be directly fed into grinders such as hammer mills and disc refiners. Hence, biomass needs to be preprocessed using coarse grinders like a knife mill to allow for efficient feeding in refiner mills without bridging and choking. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented knife mill. Direct power inputs were determined for different knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. Overall accuracy of power measurement was calculated to be +/-0.003 kW. Total specific energy (kWh/Mg) was defined as size reduction energy to operate mill with biomass. Effective specific energy was defined as the energy that can be assumed to reach the biomass. The difference is parasitic or no-load energy of mill. Total specific energy for switchgrass, wheat straw, and corn stover chopping increased with knife mill speed, whereas, effective specific energy decreased marginally for switchgrass and increased for wheat straw and corn stover. Total and effective specific energy decreased with an increase in screen size for all the crops studied. Total specific energy decreased with increase in mass feed rate, but effective specific energy increased for switchgrass and wheat straw, and decreased for corn stover at increased feed rate. For knife mill screen size of 25.4 mm and optimum speed of 250 rpm, optimum feed rates were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively, and the corresponding total specific energies were 7.57, 10.53, and 8.87 kWh/Mg and effective specific energies were 1.27, 1.50, and 0.24 kWh/Mg for switchgrass, wheat straw, and corn stover, respectively. Energy utilization ratios were calculated as 16.8%, 14.3%, and 2.8% for switchgrass, wheat straw, and corn stover, respectively. These

Identifying potential areas for biofuel production and evaluating the environmental effects: a case study of the James River Basin in the Midwestern United States

Science.gov (United States)

Wu, Yiping; Liu, Shu-Guang; Li, Zhengpeng

2012-01-01

Biofuels are now an important resource in the United States because of the Energy Independence and Security Act of 2007. Both increased corn growth for ethanol production and perennial dedicated energy crop growth for cellulosic feedstocks are potential sources to meet the rising demand for biofuels. However, these measures may cause adverse environmental consequences that are not yet fully understood. This study 1) evaluates the long-term impacts of increased frequency of corn in the crop rotation system on water quantity and quality as well as soil fertility in the James River Basin and 2) identifies potential grasslands for cultivating bioenergy crops (e.g. switchgrass), estimating the water quality impacts. We selected the soil and water assessment tool, a physically based multidisciplinary model, as the modeling approach to simulate a series of biofuel production scenarios involving crop rotation and land cover changes. The model simulations with different crop rotation scenarios indicate that decreases in water yield and soil nitrate nitrogen (NO3-N) concentration along with an increase in NO3-N load to stream water could justify serious concerns regarding increased corn rotations in this basin. Simulations with land cover change scenarios helped us spatially classify the grasslands in terms of biomass productivity and nitrogen loads, and we further derived the relationship of biomass production targets and the resulting nitrogen loads against switchgrass planting acreages. The suggested economically efficient (planting acreage) and environmentally friendly (water quality) planting locations and acreages can be a valuable guide for cultivating switchgrass in this basin. This information, along with the projected environmental costs (i.e. reduced water yield and increased nitrogen load), can contribute to decision support tools for land managers to seek the sustainability of biofuel development in this region.

Global changes in mineral transporters in tetraploid switchgrasses (Panicum virgatum L.

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Nathan A. Palmer

2014-01-01

Full Text Available Switchgrass (Panicum virgatum L is perennial, C4 grass with great potential as a biofuel crop. An in-depth understanding of the mechanisms that control mineral uptake, distribution and remobilization will benefit sustainable production. Nutrients are mobilized from aerial portions to below-ground crowns and rhizomes as a natural accompaniment to above-ground senescence post seed-set. Mineral uptake and remobilization is dependent on transporters, however, little if any information is available about the specific transporters that are needed and how their relative expression changes over a growing season. Using well-defined classes of mineral transporters, we identified 520 genes belonging to 40 different transporter classes in the tetraploid switchgrass genome. Expression patterns were determined for many of these genes using publically available transcriptomic datasets obtained from both greenhouse and field grown plants. Certain transporters showed strong temporal patterns of expression in distinct developmental stages of the plant. Gene-expression was verified for selected transporters using qRT-PCR. By and large these analyses confirmed the developmental stage-specific expression of these genes. Mineral analyses indicated that K, Fe, Mg, Co and As had a similar pattern of accumulation with apparent limited remobilization at the end of the growing season. These initial analyses will serve as a foundation for more detailed examination of the nutrient biology of switchgrass.

Model optimization of cadmium and accumulation in switchgrass (Panicum virgatum L.): potential use for ecological phytoremediation in Cd-contaminated soils.

Science.gov (United States)

Wang, Quanzhen; Gu, Muyu; Ma, Xiaomin; Zhang, Hongjuan; Wang, Yafang; Cui, Jian; Gao, Wei; Gui, Jing

2015-11-01

Soil pollution with heavy metals is an increasingly serious threat to the environment, food security, and human health. Therefore, it is urgent to develop economic and highly efficient soil restoration technology for environmental improvement; phytoremediation is an option that is safe, has low cost, and is environmentally friendly. However, in selecting hyperaccumulators or tolerant plants, theories and operation technologies for optimal restoration should be satisfied. In this study, the switchgrass growth response and performance of phytoextraction under the coupling effect of Cd and pH were investigated by evaluating seed germination, seedling growth, and the Cd content in the plant to evaluate the potential use of switchgrass as a phytoremediation plant in cadmium contaminated soil. This study conducted three sets of independent experiments with five levels of Cd concentrations, including two orthogonal matrix designs of combining Cd with pH values. The results showed that switchgrass was germinated well under all treatments (Cd concentration of 0-500 μM), but the seedling growth was significantly affected by Cd and pH, as shown by multivariate regression analyses. Hormesis was found during the growth of switchgrass plants exposed to low Cd concentrations under hydroponic conditions, and switchgrass plants were capable of developing with a Cd concentration of 100-175 μM and pH of 4.1-5.9. Mild acidic conditions can enhance the ability of Cd to accumulate in switchgrass. Switchgrass was moderately tolerant to Cd and may be used as a phytoremediation plant for Cd-contaminated soils in the future. Our results also suggest that hormetic effects should be taken into consideration in the phytoremediation of Cd-contaminated soils. We discuss the physiological and biochemical mechanisms contributing to the effective application of the plant for the phytoremediation of Cd-contaminated soils.

Willingness to pay for E85 from corn, switchgrass, and wood residues

Energy Technology Data Exchange (ETDEWEB)

Jensen, Kimberly L.; Clark, Christopher D.; English, Burton C.; Menard, R. Jamey; Skahan, Denise K.; Marra, Adrienne C. [Department of Agricultural Economics, The University of Tennessee, 302 Morgan Hall, Knoxville, TN, 37996 (United States)

2010-11-15

Willingness to pay (WTP) for E85 (automotive fuel blend of 85% ethanol and 15% gasoline) was estimated from a contingent choice exercise contained in a national survey of consumers. The choice exercise included E85 blends from three different feedstock sources (corn grain, switchgrass, and wood wastes) and an E10 blend (10% ethanol and 90% gasoline) with corn grain as the ethanol feedstock. Results from the study indicate willingness to pay a premium for E85 from switchgrass compared with E10 from corn. Concerns about land use for ''food versus fuel'' had a negative impact on WTP for E85 from corn grain, while greater concerns about fuel security relative to the environment had a positive impact. (author)

Willingness to pay for E85 from corn, switchgrass, and wood residues

International Nuclear Information System (INIS)

Jensen, Kimberly L.; Clark, Christopher D.; English, Burton C.; Menard, R. Jamey; Skahan, Denise K.; Marra, Adrienne C.

2010-01-01

Willingness to pay (WTP) for E85 (automotive fuel blend of 85% ethanol and 15% gasoline) was estimated from a contingent choice exercise contained in a national survey of consumers. The choice exercise included E85 blends from three different feedstock sources (corn grain, switchgrass, and wood wastes) and an E10 blend (10% ethanol and 90% gasoline) with corn grain as the ethanol feedstock. Results from the study indicate willingness to pay a premium for E85 from switchgrass compared with E10 from corn. Concerns about land use for ''food versus fuel'' had a negative impact on WTP for E85 from corn grain, while greater concerns about fuel security relative to the environment had a positive impact. (author)

Topsoil thickness and harvest management influence switchgrass production and profitability

Science.gov (United States)

Switchgrass (Panicum virgatum L.) is an attractive dual use forage and/or biomass crop option for eroded or marginal soils where corn (Zea mays L.) grain production often is not profitable. Topsoil thickness, especially above soils with a claypan, relates to crop productivity and nutrient removal an...

Simultaneous Downregulation of MTHFR and COMT in Switchgrass Affects Plant Performance and Induces Lesion-Mimic Cell Death

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Sijia Liu

2017-06-01

Full Text Available Switchgrass (Panicum virgatum has been developed into a model lignocellulosic bioenergy crop. Downregulation of caffeic acid O-methyltransferase (COMT, a key enzyme in lignin biosynthesis, has been shown to alter lignification and increase biofuel yield in switchgrass. Methylenetetrahydrofolate reductase (MTHFR mediates C1 metabolism and provides methyl units consumed by COMT. It was predicted that co-silencing of MTHFR and COMT would impact lignification even more than either of the single genes. However, our results showed that strong downregulation of MTHFR in a COMT-deficient background led to altered plant growth and development, but no significant change in lignin content or composition was found when compared with COMT plants. Another unexpected finding was that the double MTHFR/COMT downregulated plants showed a novel lesion-mimic leaf phenotype. Molecular analyses revealed that the lesion-mimic phenotype was caused by the synergistic effect of MTHFR and COMT genes, with MTHFR playing a predominant role. Microarray analysis showed significant induction of genes related to oxidative and defense responses. The results demonstrated the lack of additive effects of MTHFR and COMT on lignification. Furthermore, this research revealed an unexpected role of the two genes in the modulation of lesion-mimic cell death as well as their synergistic effects on agronomic performance.

Simultaneous Downregulation of MTHFR and COMT in Switchgrass Affects Plant Performance and Induces Lesion-Mimic Cell Death.

Science.gov (United States)

Liu, Sijia; Fu, Chunxiang; Gou, Jiqing; Sun, Liang; Huhman, David; Zhang, Yunwei; Wang, Zeng-Yu

2017-01-01

Switchgrass ( Panicum virgatum ) has been developed into a model lignocellulosic bioenergy crop. Downregulation of caffeic acid O -methyltransferase (COMT), a key enzyme in lignin biosynthesis, has been shown to alter lignification and increase biofuel yield in switchgrass. Methylenetetrahydrofolate reductase (MTHFR) mediates C1 metabolism and provides methyl units consumed by COMT. It was predicted that co-silencing of MTHFR and COMT would impact lignification even more than either of the single genes. However, our results showed that strong downregulation of MTHFR in a COMT -deficient background led to altered plant growth and development, but no significant change in lignin content or composition was found when compared with COMT plants. Another unexpected finding was that the double MTHFR/COMT downregulated plants showed a novel lesion-mimic leaf phenotype. Molecular analyses revealed that the lesion-mimic phenotype was caused by the synergistic effect of MTHFR and COMT genes, with MTHFR playing a predominant role. Microarray analysis showed significant induction of genes related to oxidative and defense responses. The results demonstrated the lack of additive effects of MTHFR and COMT on lignification. Furthermore, this research revealed an unexpected role of the two genes in the modulation of lesion-mimic cell death as well as their synergistic effects on agronomic performance.

Genetic variation, population structure and linkage disequilibrium in Switchgrass with ISSR, SCoT and EST-SSR markers.

Science.gov (United States)

Zhang, Yu; Yan, Haidong; Jiang, Xiaomei; Wang, Xiaoli; Huang, Linkai; Xu, Bin; Zhang, Xinquan; Zhang, Lexin

2016-01-01

To evaluate genetic variation, population structure, and the extent of linkage disequilibrium (LD), 134 switchgrass ( Panicum virgatum L.) samples were analyzed with 51 markers, including 16 ISSRs, 20 SCoTs, and 15 EST-SSRs. In this study, a high level of genetic variation was observed in the switchgrass samples and they had an average Nei's gene diversity index (H) of 0.311. A total of 793 bands were obtained, of which 708 (89.28 %) were polymorphic. Using a parameter marker index (MI), the efficiency of the three types of markers (ISSR, SCoT, and EST-SSR) in the study were compared and we found that SCoT had a higher marker efficiency than the other two markers. The 134 switchgrass samples could be divided into two sub-populations based on STRUCTURE, UPGMA clustering, and principal coordinate analyses (PCA), and upland and lowland ecotypes could be separated by UPGMA clustering and PCA analyses. Linkage disequilibrium analysis revealed an average r 2 of 0.035 across all 51 markers, indicating a trend of higher LD in sub-population 2 than that in sub-population 1 ( P  < 0.01). The population structure revealed in this study will guide the design of future association studies using these switchgrass samples.

Community dynamics and glycoside hydrolase activities of thermophilic bacterial consortia adapted to switchgrass

Energy Technology Data Exchange (ETDEWEB)

Gladden, J.M.; Allgaier, M.; Miller, C.S.; Hazen, T.C.; VanderGheynst, J.S.; Hugenholtz, P.; Simmons, B.A.; Singer, S.W.

2011-05-01

Industrial-scale biofuel production requires robust enzymatic cocktails to produce fermentable sugars from lignocellulosic biomass. Thermophilic bacterial consortia are a potential source of cellulases and hemicellulases adapted to harsher reaction conditions than commercial fungal enzymes. Compost-derived microbial consortia were adapted to switchgrass at 60 C to develop thermophilic biomass-degrading consortia for detailed studies. Microbial community analysis using small-subunit rRNA gene amplicon pyrosequencing and short-read metagenomic sequencing demonstrated that thermophilic adaptation to switchgrass resulted in low-diversity bacterial consortia with a high abundance of bacteria related to thermophilic paenibacilli, Rhodothermus marinus, and Thermus thermophilus. At lower abundance, thermophilic Chloroflexi and an uncultivated lineage of the Gemmatimonadetes phylum were observed. Supernatants isolated from these consortia had high levels of xylanase and endoglucanase activities. Compared to commercial enzyme preparations, the endoglucanase enzymes had a higher thermotolerance and were more stable in the presence of 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), an ionic liquid used for biomass pretreatment. The supernatants were used to saccharify [C2mim][OAc]-pretreated switchgrass at elevated temperatures (up to 80 C), demonstrating that these consortia are an excellent source of enzymes for the development of enzymatic cocktails tailored to more extreme reaction conditions.

7 CFR 1220.615 - State and United States.

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2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false State and United States. 1220.615 Section 1220.615... CONSUMER INFORMATION Procedures To Request a Referendum Definitions § 1220.615 State and United States. State and United States include the 50 States of the United States of America, the District of Columbia...

7 CFR 1220.129 - State and United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false State and United States. 1220.129 Section 1220.129... CONSUMER INFORMATION Soybean Promotion and Research Order Definitions § 1220.129 State and United States. The terms State and United States include the 50 States of the United States of America, the District...

Ethanol yields and cell wall properties in divergently bred switchgrass genotypes

Science.gov (United States)

Genetic modification of herbaceous plant cell walls to increase biofuels yields from harvested biomass is a primary bioenergy research goal. The focus of much of this research has been on cell wall lignin concentration. Using switchgrass genotypes developed by divergent breeding for ruminant diges...

Soil respiration, microbial biomass and exoenzyme activity in switchgrass stands under nitrogen fertilization management and climate warming.

Science.gov (United States)

Jian, S.; Li, J.; de Koff, J.; Celada, S.; Mayes, M. A.; Wang, G.; Guo, C.

2016-12-01

Switchgrass (Panicum virgatum L.), as a model bioenergy crop, received nitrogen fertilizers for increasing its biomass yields. Studies rarely investigate the interactive effects of nitrogen fertilization and climate warming on soil microbial activity and carbon cycling in switchgrass cropping systems. Enhanced nitrogen availability under fertilization can alter rates of soil organic matter decomposition and soil carbon emissions to the atmosphere and thus have an effect on climate change. Here, we assess soil CO2 emission, microbial biomass and exoenzyme activities in two switchgrass stands with no fertilizer and 60 lbs N / acre. Soils were incubated at 15 ºC and 20 ºC for 180-day. Dry switchgrass plant materials were added to incubation jars and the 13C stable isotopic probing technique was used to monitor soil CO2 respiration derived from relatively labile litter and indigenous soil. Measurements of respiration, δ13C of respiration, microbial biomass carbon and exoenzyme activity were performed on days 1, 5, 10, 15, 30, 60, 90, 120, 150 and 180. Soil respiration rate was greater in the samples incubated at 20 ºC as compared to those incubated at 15 ºC. Exoenzyme activities were significantly altered by warming, litter addition and nitrogen fertilization. There was a significant interactive effect of nitrogen fertilization and warming on the proportion of CO2 respired from soils such that nitrogen fertilization enhanced warming-induced increase by 12.0% (Pmineralization. Fertilization increased soil microbial biomass carbon at both temperatures (9.0% at 15 ºC and 14.5% at 20 ºC). Our preliminary analysis suggested that warming effects on enhanced soil respiration can be further increased with elevated fertilizer input via greater microbial biomass and exoenzyme activity. In addition to greater biomass yield under N fertilization, this study informs potential soil carbon loss from stimulated soil respiration under nitrogen fertilization and warming in

Inside out: high-efficiency plant regeneration and Agrobacterium-mediated transformation of upland and lowland switchgrass cultivars.

Science.gov (United States)

Liu, Yan-Rong; Cen, Hui-Fang; Yan, Jian-Ping; Zhang, Yun-Wei; Zhang, Wan-Jun

2015-07-01

Selection of pre-embryogenic callus from a core structure from mature seed-derived callus is the key for high-efficiency plant regeneration and transformation of switchgrass different cultivars. Switchgrass (Panicum virgatum L.) has been identified as a dedicated biofuel crop. For its trait improvement through biotechnological approaches, we have developed a highly efficient plant regeneration and genetic transformation protocol for both lowland and upland cultivars. We identified and separated a pre-embryogenic "core" structure from the seed-derived callus, which often leads to development of highly regenerative type II calluses. From the type II callus, plant regeneration rate of lowland cultivars Alamo and Performer reaches 95%, and upland cultivars Blackwell and Dacotah, 50 and 76%, respectively. The type II callus was also amenable for Agrobacterium-mediated transformation. Transformation efficiency of 72.8% was achieved for lowland cultivar Alamo, and 8.0% for upland cultivar Dacotah. PCR, Southern blot and GUS staining assays were performed to verify the transgenic events. High regenerative callus lines could be established in 3 months, and transgenic plants could be obtained in 2 months after Agrobacterium infection. To our knowledge, this is the first report on successful plant regeneration and recovery of transgenic plants from upland switchgrass cultivars by Agrobacterium-mediated transformation. The method presented here could be helpful in breaking through the bottleneck of regeneration and transformation of lowland and upland switchgrass cultivars and probably other recalcitrant grass crops.

Genome-Wide Identification, Phylogeny, and Expression Analysis of ARF Genes Involved in Vegetative Organs Development in Switchgrass

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Jianli Wang

2018-01-01

Full Text Available Auxin response factors (ARFs have been reported to play vital roles during plant growth and development. In order to reveal specific functions related to vegetative organs in grasses, an in-depth study of the ARF gene family was carried out in switchgrass (Panicum virgatum L., a warm-season C4 perennial grass that is mostly used as bioenergy and animal feedstock. A total of 47 putative ARF genes (PvARFs were identified in the switchgrass genome (2n = 4x = 36, 42 of which were anchored to the seven pairs of chromosomes and found to be unevenly distributed. Sixteen PvARFs were predicted to be potential targets of small RNAs (microRNA160 and 167. Phylogenetically speaking, PvARFs were divided into seven distinct subgroups based on the phylogeny, exon/intron arrangement, and conserved motif distribution. Moreover, 15 pairs of PvARFs have different temporal-spatial expression profiles in vegetative organs (2nd, 3rd, and 4th internode and leaves, which implies that different PvARFs have specific functions in switchgrass growth and development. In addition, at least 14 pairs of PvARFs respond to naphthylacetic acid (NAA treatment, which might be helpful for us to study on auxin response in switchgrass. The comprehensive analysis, described here, will facilitate the future functional analysis of ARF genes in grasses.

Toxicity of coal fly ash (CFA) and toxicological response of switchgrass in mycorrhiza-mediated CFA-soil admixtures.

Science.gov (United States)

Awoyemi, Olushola M; Dzantor, E Kudjo

2017-10-01

Increasing support for the use of Coal fly ash (CFA) in agriculture has necessitated a better understanding of the effects of the CFA in various cropping schemes. Experiments were conducted to assess mutagenic response of a mutant strain of Salmonella enterica serovar Typhimurium (TA100) to varying concentrations of CFA-water extracts, determine oxidative stress in switchgrass (Panicum virgatum L.) at varying levels of CFA-soil admixtures, and evaluate mycorrhiza-mediated modulation of oxidative stress responses of CFA-grown switchgrass. The TA100 exposed to 0%, 5%, 10%, 15%, 20% and 25% (w/v) CFA-water extracts elicited significant (p CFA-soil admixtures at 7.5% and 15% (w/w) significantly (p CFA/soil). Under the same conditions, activities of glutathione peroxidase (GPx) decreased by 75.9% and 66.9%. In contrast to the antioxidant enzyme activities, levels of malondialdehyde (MDA) an indicator of lipid peroxidation increased significantly (p CFA-soil admixtures with arbuscular mycorrhizal fungi (AMF), Rhizophaga clarus enhanced the activities of both SOD and GPx in the switchgrass, while it significantly (p CFA (at concentrations considered to be non-mutagenic against TA100) as soil amendment produced concentration-dependent oxidative stress responses in switchgrass; however, inoculation of the CFA-soil admixtures with AMF significantly modulated the oxidative stress responses. Copyright © 2017 Elsevier Inc. All rights reserved.

Functional Characterization of NAC and MYB Transcription Factors Involved in Regulation of Biomass Production in Switchgrass (Panicum virgatum.

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Ruiqin Zhong

Full Text Available Switchgrass is a promising biofuel feedstock due to its high biomass production and low agronomic input requirements. Because the bulk of switchgrass biomass used for biofuel production is lignocellulosic secondary walls, studies on secondary wall biosynthesis and its transcriptional regulation are imperative for designing strategies for genetic improvement of biomass production in switchgrass. Here, we report the identification and functional characterization of a group of switchgrass transcription factors, including several NACs (PvSWNs and a MYB (PvMYB46A, for their involvement in regulating secondary wall biosynthesis. PvSWNs and PvMYB46A were found to be highly expressed in stems and their expression was closely associated with sclerenchyma cells. Overexpression of PvSWNs and PvMYB46A in Arabidopsis was shown to result in activation of the biosynthetic genes for cellulose, xylan and lignin and ectopic deposition of secondary walls in normally parenchymatous cells. Transactivation and complementation studies demonstrated that PvSWNs were able to activate the SNBE-driven GUS reporter gene and effectively rescue the secondary wall defects in the Arabidopsis snd1 nst1 double mutant, indicating that they are functional orthologs of Arabidopsis SWNs. Furthermore, we showed that PvMYB46A could activate the SMRE-driven GUS reporter gene and complement the Arabidopsis myb46 myb83 double mutant, suggesting that it is a functional ortholog of Arabidopsis MYB46/MYB83. Together, these results indicate that PvSWNs and PvMYB46A are transcriptional switches involved in regulating secondary wall biosynthesis, which provides molecular tools for genetic manipulation of biomass production in switchgrass.

Switchgrass (Panicum virgatum L.) as a reinforcing fibre in polypropylene composites

NARCIS (Netherlands)

Oever, van den M.J.A.; Elbersen, H.W.; Keijsers, E.R.P.; Gosselink, R.J.A.; Klerk-Engels, de B.

2003-01-01

In this study the switchgrass (Panicum virgatum L.), a biomass crop being developed in North America and Europe, was tested as a stiffening and reinforcing agent in polypropylene (PP) composites with and without maleic anhydride grafted PP (MAPP) as a compatibiliser and to evaluate the effect of

Five nuclear loci resolve the polyploid history of switchgrass (Panicum virgatum L. and relatives.

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Jimmy K Triplett

Full Text Available Polyploidy poses challenges for phylogenetic reconstruction because of the need to identify and distinguish between homoeologous loci. This can be addressed by use of low copy nuclear markers. Panicum s.s. is a genus of about 100 species in the grass tribe Paniceae, subfamily Panicoideae, and is divided into five sections. Many of the species are known to be polyploids. The most well-known of the Panicum polyploids are switchgrass (Panicum virgatum and common or Proso millet (P. miliaceum. Switchgrass is in section Virgata, along with P. tricholaenoides, P. amarum, and P. amarulum, whereas P. miliaceum is in sect. Panicum. We have generated sequence data from five low copy nuclear loci and two chloroplast loci and have clarified the origin of P. virgatum. We find that all members of sects. Virgata and Urvilleana are the result of diversification after a single allopolyploidy event. The closest diploid relatives of switchgrass are in sect. Rudgeana, native to Central and South America. Within sections Virgata and Urvilleana, P. tricholaenoides is sister to the remaining species. Panicum racemosum and P. urvilleanum form a clade, which may be sister to P. chloroleucum. Panicum amarum, P. amarulum, and the lowland and upland ecotypes of P. virgatum together form a clade, within which relationships are complex. Hexaploid and octoploid plants are likely allopolyploids, with P. amarum and P. amarulum sharing genomes with P. virgatum. Octoploid P. virgatum plants are formed via hybridization between disparate tetraploids. We show that polyploidy precedes diversification in a complex set of polyploids; our data thus suggest that polyploidy could provide the raw material for diversification. In addition, we show two rounds of allopolyploidization in the ancestry of switchgrass, and identify additional species that may be part of its broader gene pool. This may be relevant for development of the crop for biofuels.

Switchgrass Cultivar/Ecotype Selection and Management for Biofuels in the Upper Southeast USA

Science.gov (United States)

Parrish, David J.; Wolf, Dale D.

2014-01-01

Switchgrass (Panicum virgatum L.), a perennial warm-season grass indigenous to the eastern USA, has potential as a biofuels feedstock. The objective of this study was to investigate the performance of upland and lowland switchgrass cultivars under different environments and management treatments. Four cultivars of switchgrass were evaluated from 2000 to 2001 under two management regimes in plots established in 1992 at eight locations in the upper southeastern USA. Two management treatments included 1) a single annual harvest (in late October to early November) and a single application of 50 kg N/ha/yr and 2) two annual harvests (in midsummer and November) and a split application of 100 kg N/ha/yr. Biomass yields averaged 15 Mg/ha/yr and ranged from 10 to 22 Mg/ha/yr across cultivars, managements, locations, and years. There was no yield advantage in taking two harvests of the lowland cultivars (Alamo and Kanlow). When harvested twice, upland cultivars (Cave-in-Rock and Shelter) provided yields equivalent to the lowland ecotypes. Tiller density was 36% lower in stands cutting only once per year, but the stands appeared vigorous after nine years of such management. Lowland cultivars and a one-cutting management (after the tops have senesced) using low rates of applied N (50 kg/ha) are recommended. PMID:25105170

7 CFR 1209.21 - State and United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false State and United States. 1209.21 Section 1209.21... Definitions § 1209.21 State and United States. (a) State means any of the several States, the District of Columbia, and the Commonwealth of Puerto Rico. (b) United States means collectively the several States of...

Comparison of ethanol production from corn cobs and switchgrass following a pyrolysis-based biorefinery approach.

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Luque, Luis; Oudenhoven, Stijn; Westerhof, Roel; van Rossum, Guus; Berruti, Franco; Kersten, Sascha; Rehmann, Lars

2016-01-01

One of the main obstacles in lignocellulosic ethanol production is the necessity of pretreatment and fractionation of the biomass feedstocks to produce sufficiently pure fermentable carbohydrates. In addition, the by-products (hemicellulose and lignin fraction) are of low value, when compared to dried distillers grains (DDG), the main by-product of corn ethanol. Fast pyrolysis is an alternative thermal conversion technology for processing biomass. It has recently been optimized to produce a stream rich in levoglucosan, a fermentable glucose precursor for biofuel production. Additional product streams might be of value to the petrochemical industry. However, biomass heterogeneity is known to impact the composition of pyrolytic product streams, as a complex mixture of aromatic compounds is recovered with the sugars, interfering with subsequent fermentation. The present study investigates the feasibility of fast pyrolysis to produce fermentable pyrolytic glucose from two abundant lignocellulosic biomass sources in Ontario, switchgrass (potential energy crop) and corn cobs (by-product of corn industry). Demineralization of biomass removes catalytic centers and increases the levoglucosan yield during pyrolysis. The ash content of biomass was significantly decreased by 82-90% in corn cobs when demineralized with acetic or nitric acid, respectively. In switchgrass, a reduction of only 50% for both acids could be achieved. Conversely, levoglucosan production increased 9- and 14-fold in corn cobs when rinsed with acetic and nitric acid, respectively, and increased 11-fold in switchgrass regardless of the acid used. After pyrolysis, different configurations for upgrading the pyrolytic sugars were assessed and the presence of potentially inhibitory compounds was approximated at each step as double integral of the UV spectrum signal of an HPLC assay. The results showed that water extraction followed by acid hydrolysis and solvent extraction was the best upgrading strategy

Switchgrass (Panicum virgatum Intercropping within Managed Loblolly Pine (Pinus taeda Does Not Affect Wild Bee Communities

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Joshua W. Campbell

2016-11-01

Full Text Available Intensively-managed pine (Pinus spp. have been shown to support diverse vertebrate communities, but their ability to support invertebrate communities, such as wild bees, has not been well-studied. Recently, researchers have examined intercropping switchgrass (Panicum virgatum, a native perennial, within intensively managed loblolly pine (P. taeda plantations as a potential source for cellulosic biofuels. To better understand potential effects of intercropping on bee communities, we investigated visitation of bees within three replicates of four treatments of loblolly pine in Mississippi, U.S.A.: 3–4 year old pine plantations and 9–10 year old pine plantations with and without intercropped switchgrass. We used colored pan traps to capture bees during the growing seasons of 2013 and 2014. We captured 2507 bees comprised of 18 different genera during the two-year study, with Lasioglossum and Ceratina being the most common genera captured. Overall, bee abundances were dependent on plantation age and not presence of intercropping. Our data suggests that switchgrass does not negatively impact or promote bee communities within intensively-managed loblolly pine plantations.

Switchgrass (Panicum virgatum) Intercropping within Managed Loblolly Pine (Pinus taeda) Does Not Affect Wild Bee Communities.

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Campbell, Joshua W; Miller, Darren A; Martin, James A

2016-11-04

Intensively-managed pine ( Pinus spp.) have been shown to support diverse vertebrate communities, but their ability to support invertebrate communities, such as wild bees, has not been well-studied. Recently, researchers have examined intercropping switchgrass ( Panicum virgatum ), a native perennial, within intensively managed loblolly pine ( P. taeda ) plantations as a potential source for cellulosic biofuels. To better understand potential effects of intercropping on bee communities, we investigated visitation of bees within three replicates of four treatments of loblolly pine in Mississippi, U.S.A.: 3-4 year old pine plantations and 9-10 year old pine plantations with and without intercropped switchgrass. We used colored pan traps to capture bees during the growing seasons of 2013 and 2014. We captured 2507 bees comprised of 18 different genera during the two-year study, with Lasioglossum and Ceratina being the most common genera captured. Overall, bee abundances were dependent on plantation age and not presence of intercropping. Our data suggests that switchgrass does not negatively impact or promote bee communities within intensively-managed loblolly pine plantations.

Utility of remote sensing-based surface energy balance models to track water stress in rain-fed switchgrass under dry and wet conditions

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The ability of remote sensing-based surface energy balance (SEB) models to track water stress in rain-fed switchgrass has not been explored yet. In this paper, the theoretical framework of crop water stress index (CWSI) was utilized to estimate CWSI in rain-fed switchgrass (Panicum virgatum L.) usin...

Plant mortality and natural selection may increase biomass yield in switchgrass swards

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Switchgrass (Panicum virgatum L.) is an important candidate for bioenergy feedstock production, prompting significant efforts to increase the number of breeding programs and the output of those programs. The objective of this experiment was to determine the potential utility of natural selection for...

An evaluation of biomass yield stability of switchgrass (Panicum virgatum L.) cultivars

International Nuclear Information System (INIS)

Sharma, N.; Piscioneri, I.; Pignatelli, V.

2003-01-01

The present work deals with evaluation of the adaptation and biomass production of various switchgrass cultivars (upland and lowland type) in Southern Italy. A field trial was established in 1998 with 15 switchgrass varieties in ENEA Trisaia (Matera). The experiment was conducted for four years (1998-2001). During each growing period, a series of measurements were taken. At the end of each growing season, a final harvest was made in order to estimate the fresh and dry matter yields of the different varieties. The mean dry matter yield was recorded at a maximum (12.36 t/ha) in the third year, and it fluctuated from 5.63 (9005439) to 26.08 (SL 93-3) t/ha. The crop yields tend to stabilize from the fourth year of its cultivation. In fact, the yield recorded for this year was reduced to 10.27 t/ha, averaged over all the varieties

7 CFR 1160.104 - United States.

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2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true United States. 1160.104 Section 1160.104 Agriculture... Definitions § 1160.104 United States. United States means the 48 contiguous states in the continental United States and the District of Columbia, except that United States means the 50 states of the United States...

Deciphering Natural Allelic Variation in Switchgrass for Biomass Yield and Quality Using a Nested Association Mapping Population

Energy Technology Data Exchange (ETDEWEB)

Saha, Malay C. [The Samuel Roberts Noble Foundation, Inc., Ardmore, OK (United States). Forage Improvement Division (FID); Brummer, E. Charles [The Samuel Roberts Noble Foundation, Inc., Ardmore, OK (United States); Kaeppler, Shawn [Univ. of Wisconsin, Madison, WI (United States); Bhandari, Hem S. [Univ. of Tennessee, Knoxville, TN (United States)

2016-10-28

Switchgrass (Panicum virgatum L.) is a C4 grass with high biomass yield potential and a model species for bioenergy feedstock development. Understanding the genetic basis of quantitative traits is essential to facilitate genome-enabled breeding programs. The nested association mapping (NAM) analysis combines the best features of both bi-parental and association analyses and can provide high power and high resolution in QTL detection and will ensure significant improvements in biomass yield and quality. To develop a NAM population of switchgrass, 15 highly diverse genotypes with specific characteristics were selected from a diversity panel and crossed to a recurrent parent, AP13, a genotype selected for whole genome sequencing and parent of a mapping population. Ten genotypes from each of the 15 F1 families were then chain crossed. Progenies form each family were randomly selected to develop the NAM population. The switchgrass NAM population consists of a total of 2000 genotypes from 15 families. All the progenies, founder parents, F1 parents (n=2350) were evaluated in replicated field trials at Ardmore, OK and Knoxville, TN. Phenotypic data on plant height, tillering ability, regrowth, flowering time, and biomass yield were collected. Dried biomass samples were also analyzed using prediction equations of NIRS at the Noble Foundation and for lignin content, S/G ratio, and sugar release characteristics at the NREL. Genomic shotgun sequencing of 15 switchgrass NAM founder parental genomes at JGI produced 28-66 Gb high-quality sequence data. Alignment of these sequences with the reference genome, AP13 (v3.0), revealed that up to 99% of the genomic sequences mapped to the reference genome. A total of 2,149 individuals from NAM populations were sequenced by exome capture and two sets of 15 SNP matrices (one for each family) were generated. QTL associated with important traits have been identified and verified in breeding populations. The QTL detected and their associated

Effects of precipitation changes on switchgrass photosynthesis, growth, and biomass: A mesocosm experiment.

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Hui, Dafeng; Yu, Chih-Li; Deng, Qi; Dzantor, E Kudjo; Zhou, Suping; Dennis, Sam; Sauve, Roger; Johnson, Terrance L; Fay, Philip A; Shen, Weijun; Luo, Yiqi

2018-01-01

Climate changes, including chronic changes in precipitation amounts, will influence plant physiology and growth. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. We conducted a two-year precipitation simulation experiment using large pots (95 L) in an environmentally controlled greenhouse in Nashville, TN. Five precipitation treatments (ambient precipitation, and -50%, -33%, +33%, and +50% of ambient) were applied in a randomized complete block design with lowland "Alamo" switchgrass plants one year after they were established from tillers. The growing season progression of leaf physiology, tiller number, height, and aboveground biomass were determined each growing season. Precipitation treatments significantly affected leaf physiology, growth, and aboveground biomass. The photosynthetic rates in the wet (+50% and +33%) treatments were significantly enhanced by 15.9% and 8.1%, respectively, than the ambient treatment. Both leaf biomass and plant height were largely increased, resulting in dramatically increases in aboveground biomass by 56.5% and 49.6% in the +50% and +33% treatments, respectively. Compared to the ambient treatment, the drought (-33% and -50%) treatments did not influence leaf physiology, but the -50% treatment significantly reduced leaf biomass by 37.8%, plant height by 16.3%, and aboveground biomass by 38.9%. This study demonstrated that while switchgrass in general is a drought tolerant grass, severe drought significantly reduces Alamo's growth and biomass, and that high precipitation stimulates its photosynthesis and growth.

Dechlorination of PCBs in the rhizosphere of switchgrass and poplar

International Nuclear Information System (INIS)

Meggo, Richard E.; Schnoor, Jerald L.; Hu, Dingfei

2013-01-01

Polychlorinated biphenyl (PCB) congeners (PCB 52, 77, and 153) singly and in mixture were spiked and aged in soil microcosms and subsequently planted with switchgrass (Panicum virgatum) or poplar (Populus deltoids x nigra DN34). The planted reactors showed significantly greater reductions in PCB parent compounds when compared to unplanted systems after 32 weeks. There was evidence of reductive dechlorination in both planted and unplanted systems, but the planted microcosms with fully developed roots and rhizospheres showed greater biotransformation than the unplanted reactors. These dechlorination products accounted for approximately all of the molar mass of parent compound lost. Based on the transformation products, reductive dechlorination pathways are proposed for rhizospheric biotransformation of PCB 52, 77, and 153. This is the first report of rhizosphere biotransformation pathways for reductive dechlorination in marginally aerobic, intermittently flooded soil as evidenced by a mass balance on transformation products. -- Highlights: •Soil was spiked and aged and then planted with poplar and switchgrass. •Planted microcosms showed significant reductive dechlorination and greater biotransformation than unplanted reactor. •Rhizospheric reductive dechlorination pathways are proposed. -- This study provides insight into rhizospheric transformation of PCBs

Evaluating the impacts of landscape positions and nitrogen fertilizer rates on dissolved organic carbon on switchgrass land seeded on marginally yielding cropland.

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Lai, Liming; Kumar, Sandeep; Mbonimpa, Eric G; Hong, Chang Oh; Owens, Vance N; Neupane, Ram P

2016-04-15

Dissolved organic carbon (DOC) through leaching into the soils is another mechanism of net C loss. It plays an important role in impacting the environment and impacted by soil and crop management practices. However, little is known about the impacts of landscape positions and nitrogen (N) fertilizer rates on DOC leaching in switchgrass (Panicum virgatum L.). This experimental design included three N fertilizer rates [0 (low); 56 (medium); 112 (high) kg N ha(-1)] and three landscape positions (shoulder, backslope and footslope). Daily average DOC contents at backslope were significantly lower than that at shoulder and footslope. The DOC contents from the plots that received medium N rate were also significantly lower than the plots that received low N rates. The interactions of landscape and N rates on DOC contents were different in every year from 2009 to 2014, however, no significant consistent trend of DOC contents was observed over time. Annual average DOC contents from the plots managed with low N rate were higher than those with high N rate. These contents at the footslope were higher than that at the shoulder position. Data show that there is a moderate positive relationship between the total average DOC contents and the total average switchgrass biomass yields. Overall, the DOC contents from leachate in the switchgrass land were significantly influenced by landscape positions and N rates. The N fertilization reduced DOC leaching contents in switchgrass field. The switchgrass could retain soil and environment sustainability to some extent. These findings will assist in understanding the mechanism of changes in DOC contents with various parameters in the natural environment and crop management systems. However, use of long-term data might help to better assess the effects of above factors on DOC leaching contents and loss in the switchgrass field in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

Towards the Development of a Molecular Map in Switchgrass: I. Microsatellite Marker Development; ANNUAL

International Nuclear Information System (INIS)

Gunter, L.E.

2001-01-01

The long-term goal of the switchgrass breeding program is to improve regionally adapted varieties and increase biomass yield and feedstock quality. Although, to some extent, biomass yields are dependent on environmental constraints, increased yield can be achieved through the development of genotypes with improved seasonal adaptation, tolerance to unfavorable environmental conditions, and improved resistance to pest and disease. To date, improvement in switchgrass has relied on recurrent breeding strategies based on phenotypic or genotypic selection. Yield improvements have been modest by this method. If we expect to make significant increase in yields, we need tools that will allow us to map complex traits and uncover the genes that influence them. A genetic linkage map could be a powerful tool for accelerating switchgrass development through marker-assisted selection, breeding and recombination. This type of mapping requires the development of markers that can be associated with phenotypic traits in a population of known pedigree. The most commonly used markers for mapping include restriction fragment length polymorphisms (RFLP) and simple sequence repeats (SSR). At ORNL, we have been concentrating on the development of SSR markers, while our colleagues at the University of Georgia are developing RFLP markers in order to select parents to produce a mapping population and from there to create a framework map from(approx)100 F1 progeny

Identification and overexpression of a Knotted1-like transcription factor in switchgrass (Panicum virgatum L. for lignocellulosic feedstock improvement

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Wegi eWuddineh

2016-04-01

Full Text Available High biomass production and wide adaptation has made switchgrass (Panicum virgatum L. an important candidate lignocellulosic bioenergy crop. One major limitation of this and other lignocellulosic feedstocks is the recalcitrance of complex carbohydrates to hydrolysis for conversion to biofuels. Lignin is the major contributor to recalcitrance as it limits the accessibility of cell wall carbohydrates to enzymatic breakdown into fermentable sugars. Therefore, genetic manipulation of the lignin biosynthesis pathway is one strategy to reduce recalcitrance. Here, we identified a switchgrass Knotted1 transcription factor, PvKN1, with the aim of genetically engineering switchgrass for reduced biomass recalcitrance for biofuel production. Gene expression of the endogenous PvKN1 gene was observed to be highest in young inflorescences and stems. Ectopic overexpression of PvKN1 in switchgrass altered growth, especially in early developmental stages. Transgenic lines had reduced expression of most lignin biosynthetic genes accompanied by a reduction in lignin content suggesting the involvement of PvKN1 in the broad regulation of the lignin biosynthesis pathway. Moreover, the reduced expression of the Gibberellin 20-oxidase (GA20ox gene in tandem with the increased expression of Gibberellin 2-oxidase (GA2ox genes in transgenic PvKN1 lines suggest that PvKN1 may exert regulatory effects via modulation of GA signalling. Furthermore, overexpression of PvKN1 altered the expression of cellulose and hemicellulose biosynthetic genes and increased sugar release efficiency in transgenic lines. Our results demonstrated that switchgrass PvKN1 is a putative ortholog of maize KN1 that is linked to plant lignification and cell wall and development traits as a major regulatory gene. Therefore, targeted overexpression of PvKN1 in bioenergy feedstocks may provide one feasible strategy for reducing biomass recalcitrance and simultaneously improving plant growth characteristics.

Effects of precipitation changes on switchgrass photosynthesis, growth, and biomass: A mesocosm experiment

Science.gov (United States)

Climate changes, including chronic changes in precipitation amounts, will influence plant physiology and growth. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. We conducted a two-year precipitation simulation experiment using large pots...

Bio-butanol vs. bio-ethanol: A technical and economic assessment for corn and switchgrass fermented by yeast or Clostridium acetobutylicum

International Nuclear Information System (INIS)

Pfromm, Peter H.; Amanor-Boadu, Vincent; Nelson, Richard; Vadlani, Praveen; Madl, Ronald

2010-01-01

Fermentation-derived butanol is a possible alternative to ethanol as a fungible biomass-based liquid transportation fuel. We compare the fermentation-based production of n-butanol vs. ethanol from corn or switchgrass through the liquid fuel yield in terms of the lower heating value (LHV). Industrial scale data on fermentation to n-butanol (ABE fermentation) or ethanol (yeast) establishes a baseline at this time, and puts recent advances in fermentation to butanol in perspective. A dynamic simulation demonstrates the technical, economic and policy implications. The energy yield of n-butanol is about half that of ethanol from corn or switchgrass using current ABE technology. This is a serious disadvantage for n-butanol since feedstock costs are a significant portion of the fuel price. Low yield increases n-butanol's life-cycle greenhouse gas emission for the same amount of LHV compared to ethanol. A given fermenter volume can produce only about one quarter of the LHV as n-butanol per unit time compared to ethanol. This increases capital costs. The sometimes touted advantage of n-butanol being more compatible with existing pipelines is, according to our techno-economic simulations insufficient to alter the conclusion because of the capital costs to connect plants via pipeline.

Modeling the impacts of temperature and precipitation changes on soil CO2 fluxes from a Switchgrass stand recently converted from cropland.

Science.gov (United States)

Lai, Liming; Kumar, Sandeep; Chintala, Rajesh; Owens, Vance N; Clay, David; Schumacher, Joseph; Nizami, Abdul-Sattar; Lee, Sang Soo; Rafique, Rashad

2016-05-01

Switchgrass (Panicum virgatum L.) is a perennial C4 grass native to North America and successfully adapted to diverse environmental conditions. It offers the potential to reduce soil surface carbon dioxide (CO2) fluxes and mitigate climate change. However, information on how these CO2 fluxes respond to changing climate is still lacking. In this study, CO2 fluxes were monitored continuously from 2011 through 2014 using high frequency measurements from Switchgrass land seeded in 2008 on an experimental site that has been previously used for soybean (Glycine max L.) in South Dakota, USA. DAYCENT, a process-based model, was used to simulate CO2 fluxes. An improved methodology CPTE [Combining Parameter estimation (PEST) with "Trial and Error" method] was used to calibrate DAYCENT. The calibrated DAYCENT model was used for simulating future CO2 emissions based on different climate change scenarios. This study showed that: (i) the measured soil CO2 fluxes from Switchgrass land were higher for 2012 which was a drought year, and these fluxes when simulated using DAYCENT for long-term (2015-2070) provided a pattern of polynomial curve; (ii) the simulated CO2 fluxes provided different patterns with temperature and precipitation changes in a long-term, (iii) the future CO2 fluxes from Switchgrass land under different changing climate scenarios were not significantly different, therefore, it can be concluded that Switchgrass grown for longer durations could reduce changes in CO2 fluxes from soil as a result of temperature and precipitation changes to some extent. Copyright © 2015. Published by Elsevier B.V.

31 CFR 800.225 - United States.

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2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 800.225 Section 800... TAKEOVERS BY FOREIGN PERSONS Definitions § 800.225 United States. The term United States or U.S. means the United States of America, the States of the United States, the District of Columbia, and any commonwealth...

7 CFR 1150.106 - United States.

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2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true United States. 1150.106 Section 1150.106 Agriculture... Order Definitions § 1150.106 United States. United States means the 48 contiguous States in the continental United States. ...

Malaria Treatment (United States)

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... Providers, Emergency Consultations, and General Public. Contact Us Malaria Treatment (United States) Recommend on Facebook Tweet Share Compartir Treatment of Malaria: Guidelines For Clinicians (United States) Download PDF version ...

7 CFR 65.255 - United States.

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2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false United States. 65.255 Section 65.255 Agriculture..., PEANUTS, AND GINSENG General Provisions Definitions § 65.255 United States. United States means the 50... United States. ...

7 CFR 1250.308 - United States.

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2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1250.308 Section 1250.308 Agriculture... Research and Promotion Order Definitions § 1250.308 United States. United States means the 48 contiguous States of the United States of America and the District of Columbia. ...

7 CFR 1205.23 - United States.

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2010-01-01

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31 CFR 597.318 - United States.

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2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 597.318 Section 597... General Definitions § 597.318 United States. The term United States means the United States, its territories, states, commonwealths, districts, and possessions, and all areas under the jurisdiction or...

7 CFR 1219.26 - United States.

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2010-01-01

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7 CFR 1212.31 - United States.

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2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1212.31 Section 1212.31 Agriculture..., Consumer Education, and Industry Information Order Definitions § 1212.31 United States. “United States... territories and possessions of the United States. ...

22 CFR 120.13 - United States.

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2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false United States. 120.13 Section 120.13 Foreign... United States. United States, when used in the geographical sense, includes the several states, the Commonwealth of Puerto Rico, the insular possessions of the United States, the District of Columbia, the...

Soil and variety effects on energy use and carbon emissions associated with switchgrass-based ethanol production in Mississippi

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Woli, Prem; Paz, Joel O.; Baldwin, Brian S.; Lang, David J.; Kiniry, James R.

2012-06-29

High biomass production potential, wide adaptability, low input requirement, and low environmental risk make switchgrass an economically and ecologically viable energy crop.The inherent variablity in switchgrass productivity due to variations in soil and variety could affect the sustainability and eco-friendliness of switchgrass-based ethanol production. This study examined the soil and variety effects on these variables. Three locations in Mississippi were selected based on latitude and potential acreage. Using ALMANAC, switchgrass biomass yields were simulated for several scenarios of soils and varities. The simulated yields were fed to IBSAL to compute energy use and CO2 emissions in various operations in the biomass supply From the energy and emissions values, the sustainability and eco-friendliness of ethanol production were determined using net energy value (NEV) and carbon credit balance (CCB) as indicators, respectively. Soil and variety effects on NEV and CCB were analyzed using the Kruskal-Wallis test. Results showed significant differences in NEV and CCB across soils and varieties. Both NEV and CCB increased in the direction of heavier to lighter soils and on the order of north-upland , south-upland, north-lowland, and south-lowland varieties. Only north-upland and south-lowland varieties were significantly significantly different because they were different in both cytotype and ecotype. Gaps between lowland and upland varieties were smaller in a dry year than in a wet year. The NEV and CCB increased in the direction of dry to wet year. From south to north, they decreased for lowland cytotypes but increased for upland cytotypes. Thus, the differences among varieties decreased northwards.

31 CFR 592.311 - United States.

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2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 592.311 Section 592... § 592.311 United States. The term United States, when used in the geographic sense, means the several States, the District of Columbia, and any commonwealth, territory, or possession of the United States. ...

Targeted mutagenesis in tetraploid switchgrass (Panicum virgatum L.) using CRISPR/Cas9.

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Liu, Yang; Merrick, Paul; Zhang, Zhengzhi; Ji, Chonghui; Yang, Bing; Fei, Shui-Zhang

2018-02-01

The CRISPR/Cas9 system has become a powerful tool for targeted mutagenesis. Switchgrass (Panicum virgatum L.) is a high yielding perennial grass species that has been designated as a model biomass crop by the U.S. Department of Energy. The self-infertility and high ploidy level make it difficult to study gene function or improve germplasm. To overcome these constraints, we explored the feasibility of using CRISPR/Cas9 for targeted mutagenesis in a tetraploid cultivar 'Alamo' switchgrass. We first developed a transient assay by which a non-functional green-fluorescent protein gene containing a 1-bp frameshift insertion in its 5' coding region was successfully mutated by a Cas9/sgRNA complex resulting in its restored function. Agrobacterium-mediated stable transformation of embryogenic calli derived from mature caryopses averaged a 3.0% transformation efficiency targeting the genes of teosinte branched 1(tb1)a and b and phosphoglycerate mutase (PGM). With a single construct containing two sgRNAs targeting different regions of tb1a and tb1b genes, primary transformants (T0) containing CRISPR/Cas9-induced mutations were obtained at frequencies of 95.5% (tb1a) and 11% (tb1b), respectively, with T0 mutants exhibiting increased tiller production. Meanwhile, a mutation frequency of 13.7% was obtained for the PGM gene with a CRISPR/Cas9 construct containing a single sgRNA. Among the PGM T0 mutants, six are heterozygous and one is homozygous for a 1-bp deletion in the target region with no apparent phenotypical alterations. We show that CRISPR/Cas9 system can generate targeted mutagenesis effectively and obtain targeted homozygous mutants in T0 generation in switchgrass, circumventing the need of inbreeding. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

7 CFR 1205.313 - United States.

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2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1205.313 Section 1205.313 Agriculture... Research and Promotion Order Definitions § 1205.313 United States. United States means the 50 States of the United States of America. [31 FR 16758, Dec. 31, 1966. Redesignated at 56 FR 64472, Dec. 10, 1991] ...

31 CFR 542.310 - United States.

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2010-07-01

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31 CFR 548.310 - United States.

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2010-07-01

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31 CFR 546.310 - United States.

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2010-07-01

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31 CFR 586.318 - United States.

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2010-07-01

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31 CFR 537.318 - United States.

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2010-07-01

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31 CFR 585.316 - United States.

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2010-07-01

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31 CFR 575.319 - United States.

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2010-07-01

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31 CFR 539.312 - United States.

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2010-07-01

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31 CFR 551.309 - United States.

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2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 551.309 Section 551.309 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF....309 United States. The term United States means the United States, its territories and possessions...

31 CFR 587.310 - United States.

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2010-07-01

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31 CFR 547.310 - United States.

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2010-07-01

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31 CFR 598.317 - United States.

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2010-07-01

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31 CFR 596.312 - United States.

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2010-07-01

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31 CFR 538.314 - United States.

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2010-07-01

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31 CFR 543.310 - United States.

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2010-07-01

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31 CFR 594.313 - United States.

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2010-07-01

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31 CFR 588.310 - United States.

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2010-07-01

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31 CFR 536.315 - United States.

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2010-07-01

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31 CFR 544.310 - United States.

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2010-07-01

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31 CFR 545.313 - United States.

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2010-07-01

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31 CFR 595.314 - United States.

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2010-07-01

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31 CFR 560.307 - United States.

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2010-07-01

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31 CFR 593.311 - United States.

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2010-07-01

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31 CFR 541.310 - United States.

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2010-07-01

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31 CFR 540.313 - United States.

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2010-07-01

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Gas exchange and stand-level estimates of water use and gross primary productivity in an experimental pine and switchgrass intercrop forestry system on the Lower Coastal Plain of North Carolina, U.S.A

Science.gov (United States)

Janine M. Albaugha; Jean-Christophe Domeca; Chris A. Maier; Eric B. Sucre; Zakiya H. Leggett; John S. King

2014-01-01

Despite growing interest in using switchgrass (Panicum virgatum L.) as a biofuel, there are limiteddata on the physiology of this species and its effect on stand water use and carbon (C) assimilationwhen grown as a forest intercrop for bioenergy. Therefore, we quantified gas exchange rates of switch-grass within intercropped plots and in pure switchgrass plots during...

Predicted harvest time effects on switchgrass moisture content, nutrient concentration, yield, and profitability

Science.gov (United States)

Production costs change with harvest date of switchgrass (Panicum virgatum L.) as a result of nutrient recycling and changes in yield of this perennial crop. This study examines the range of cost of production from an early, yield-maximizing harvest date to a late winter harvest date at low moisture...

7 CFR 1206.23 - United States.

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2010-01-01

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7 CFR 1215.20 - United States.

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2010-01-01

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7 CFR 1280.127 - United States.

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2010-01-01

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7 CFR 1260.108 - United States.

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2010-01-01

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7 CFR 1221.32 - United States.

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2010-01-01

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7 CFR 1216.30 - United States.

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2010-01-01

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7 CFR 1218.22 - United States.

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2010-01-01

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7 CFR 1210.315 - United States.

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2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1210.315 Section 1210.315 Agriculture... PLAN Watermelon Research and Promotion Plan Definitions § 1210.315 United States. United States means each of the several States and the District of Columbia. [60 FR 10797, Feb. 28, 1995] National...

Temporal dynamics of fibrolytic and methanogenic rumen microorganisms during in situ incubation of switchgrass determined by 16S rRNA gene profiling

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Hailan ePiao

2014-07-01

Full Text Available The rumen is known for its biomass-degrading and methane-producing phenotype. Fermentation of recalcitrant plant material necessitates the synergistic activity of diverse microbial taxonomic groups that inhabit this anaerobic environment. Although interspecies hydrogen (H2 transfer, a process during which bacterially generated H2 is transferred to methanogenic Archaea, has obtained significant attention over the last decades, the temporal variation of the different taxa involved in in situ biomass-degradation, H2 transfer and methanogenesis process remains to be established. We investigated the temporal succession of microbial taxa and its effect on fiber composition during rumen incubation using 16S rRNA amplicon sequencing. Switchgrass filled nylon bags were placed in the rumen of a cannulated cow and collected at nine time points for DNA extraction and 16S pyrotag profiling. The microbial community colonizing the air-dried and non-incubated switchgrass was dominated by members of the Bacilli. During in situ incubation of the switchgrass, two major shifts in the community composition were observed: Bacilli were replaced within 30 min by members belonging to the Bacteroidia and Clostridia. A second significant shift was observed after 16 h of rumen incubation, when members of the Spirochaetes and Fibrobacteria classes became more abundant in the fiber-adherent community. During the first 30 min of rumen incubation ~13% of the switchgrass dry matter was degraded, whereas little biomass degradation appeared to have occurred between 30 min and 4 h after the switchgrass was placed in the rumen. Interestingly, methanogenic members of the Euryarchaeota increased up to 3-fold during this period of reduced biomass-degradation, with peak abundance just before rates of dry matter degradation increased again. We hypothesize that during this period microbial-mediated fibrolysis was temporarily inhibited until H2 was metabolized into CH4 by methanogens.

The Hunt for Green Every April: Factors Affecting Fitness in Switchgrass

Energy Technology Data Exchange (ETDEWEB)

Sarath, Gautam [US Dept. of Agriculture (USDA), Lincoln, NE (United States). Agricultural Research Service (ARS). Wheat, Sorghum and Forage Research

2014-12-10

This grant funded work was undertaken to develop fundamental biological knowledge of the factors affecting the complex plant trait “fitness” in switchgrass (Panicum virgatum L.), a plant being developed as a biomass crop. Using a diverse range of latitudinally-adapted switchgrass plants, genomic, molecular and physiological studies were performed to track a number of different aspects of plant genetics and physiology over the course of the growing season. Work was performed on both genetically unrelated and genetically related plants. Plants were established in the field from seedlings raised in a greenhouse, or from clones present in other field nurseries. Field grown plants were used as the source of all tissues. The three objectives of this proposal were:(1) Transcript Profiling, Metabolomics, and C and N Partitioning and Recycling in Crowns and Rhizomes of Switchgrass over two growing seasons; (2) Gene Profiling During Regreening and Dormancy of Bulked Segregants; (3) Extent of Linkage Disequilibrium in Populations for Adaptation and Fitness Traits Being Developed for Central and Northern USA, that Show Significant Heterosis. Objective 1 results: Plants were labeled using ¹³CO2 (a stable isotope) using an acrylic chamber constructed specifically for this purpose. Plants became labeled with ¹³C and label decayed in aerial tissues over the course of the growing season. Varying amounts of ¹³C were recovered in the rhizomes. These data are being analyzed. Plants were also labeled with ¹⁵N-urea. Plants absorbed significant amounts of label that was remobilized to the growing shoots. N-dynamics would suggest that a portion of the ¹⁵N absorbed into the crowns and rhizomes is sequestered below ground. Variable amounts of ¹⁵N were translocated from the shoots to the roots over the course of the growing season. Polar metabolites extracted from a diverse array of rhizomes were analyzed using GCMS. Data

The adoption of switchgrass and miscanthus by farmers: Impact of liquidity constraints and risk preferences

International Nuclear Information System (INIS)

Bocqueho, G.; Jacquet, F.

2010-01-01

Lignocellulosic biomass is expected to become a key feedstock for renewable energy production. However, the potential supply strongly depends on farmers' willingness to grow the new perennial energy crops. Many economic assessments have been led at the farm level, all based on the standard net present value approach. This paper looks into the effect of farmers' liquidity constraints and risk preferences on switchgrass and miscanthus adoption by farmers. We study the problem of the land allocation between a traditional cropping system and an innovative one in a static framework, using four intertemporal choice models. We find that, in central France agronomic and economic conditions, switchgrass and miscanthus result to be less profitable in terms of annualised net margin than the usual rape/wheat/barley rotation. Nevertheless, they can be highly competitive as diversification crops when appropriate contracts are offered to farmers, despite the additional liquidity they require.

Projecting the land cover change and its environmental impacts in the Cedar River Basin in the Midwestern United States

Science.gov (United States)

Wu, Yiping; Liu, Shuguang; Sohl, Terry L.; Young, Claudia

2013-01-01

The physical surface of the Earth is in constant change due to climate forcing and human activities. In the Midwestern United States, urban area, farmland, and dedicated energy crop (e.g., switchgrass) cultivation are predicted to expand in the coming decades, which will lead to changes in hydrological processes. This study is designed to (1) project the land use and land cover (LULC) by mid-century using the FORecasting SCEnarios of future land-use (FORE-SCE) model under the A1B greenhouse gas emission scenario (future condition) and (2) assess its potential impacts on the water cycle and water quality against the 2001 baseline condition in the Cedar River Basin using the physically based soil and water assessment tool (SWAT). We compared the baseline LULC (National Land Cover data 2001) and 2050 projection, indicating substantial expansions of urban area and pastureland (including the cultivation of bioenergy crops) and a decrease in rangeland. We then used the above two LULC maps as the input data to drive the SWAT model, keeping other input data (e.g., climate) unchanged to isolate the LULC change impacts. The modeling results indicate that quick-response surface runoff would increase significantly (about 10.5%) due to the projected urban expansion (i.e., increase in impervious areas), and the baseflow would decrease substantially (about 7.3%) because of the reduced infiltration. Although the net effect may cause an increase in water yield, the increased variability may impede its use for public supply. Additionally, the cultivation of bioenergy crops such as switchgrass in the newly added pasture lands may further reduce the soil water content and lead to an increase in nitrogen loading (about 2.5% increase) due to intensified fertilizer application. These study results will be informative to decision makers for sustainable water resource management when facing LULC change and an increasing demand for biofuel production in this area.

Projecting the land cover change and its environmental impacts in the Cedar River Basin in the Midwestern United States

International Nuclear Information System (INIS)

Wu Yiping; Liu Shuguang; Sohl, Terry L; Young, Claudia J

2013-01-01

The physical surface of the Earth is in constant change due to climate forcing and human activities. In the Midwestern United States, urban area, farmland, and dedicated energy crop (e.g., switchgrass) cultivation are predicted to expand in the coming decades, which will lead to changes in hydrological processes. This study is designed to (1) project the land use and land cover (LULC) by mid-century using the FORecasting SCEnarios of future land-use (FORE-SCE) model under the A1B greenhouse gas emission scenario (future condition) and (2) assess its potential impacts on the water cycle and water quality against the 2001 baseline condition in the Cedar River Basin using the physically based soil and water assessment tool (SWAT). We compared the baseline LULC (National Land Cover data 2001) and 2050 projection, indicating substantial expansions of urban area and pastureland (including the cultivation of bioenergy crops) and a decrease in rangeland. We then used the above two LULC maps as the input data to drive the SWAT model, keeping other input data (e.g., climate) unchanged to isolate the LULC change impacts. The modeling results indicate that quick-response surface runoff would increase significantly (about 10.5%) due to the projected urban expansion (i.e., increase in impervious areas), and the baseflow would decrease substantially (about 7.3%) because of the reduced infiltration. Although the net effect may cause an increase in water yield, the increased variability may impede its use for public supply. Additionally, the cultivation of bioenergy crops such as switchgrass in the newly added pasture lands may further reduce the soil water content and lead to an increase in nitrogen loading (about 2.5% increase) due to intensified fertilizer application. These study results will be informative to decision makers for sustainable water resource management when facing LULC change and an increasing demand for biofuel production in this area. (letter)

Comparative transcriptomic analyses of differentially expressed genes in transgenic melatonin biosynthesis ovine HIOMT gene in switchgrass

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Shan Yuan

2016-11-01

Full Text Available Melatonin serves pleiotropic functions in prompting plant growth and resistance to various stresses. The accurate biosynthetic pathway of melatonin remains elusive in plant species, while the N-acetyltransferase and O-methyltransferase were considered to be the last two key enzymes during its biosynthesis. To investigate the biosynthesis and metabolic pathway of melatonin in plants, the RNA-seq profile of overexpression of the ovine HIOMT was analyzed and compared with the previous transcriptome of transgenic oAANAT gene in switchgrass, a model plant for cellulosic ethanol production. A total of 946, 405 and 807 differentially expressed unigenes were observed in AANAT vs. control, HIOMT vs. control, and AANAT vs. HIOMT, respectively. The significantly upregulated (F-box/kelch-repeat protein, zinc finger BED domain-containing protein-3 genes were consistent with enhanced phenotypes of shoot, stem and root growth in transgenic oHIOMT switchgrass. Early flowering in overexpression of oHIOMT switchgrass involved in the regulation of flowering-time genes (APETALA2. Several stress resistant related genes (SPX domain-containing membrane protein, copper transporter 1, late blight resistance protein homolog R1A-6 OS etc. were specifically and significantly upregulated in transgenic oHIOMT only, while metabolism-related genes (phenylalanine-4-hydroxylase, tyrosine decarboxylase 1, protein disulfide-isomerase and galactinol synthase 2 etc. were significantly upregulated in transgenic oAANAT only. These results provide new sights into the biosynthetic and physiological functional networks of melatonin in plants.

Responses of switchgrass soil respiration and its components to precipitation gradient in a mescocosm study

Science.gov (United States)

The objectives of this study were to investigate the effects of the precipitation changes on soil, microbial and root respirations of switchgrass soils, and the relationships between soil respiration and plant growth, soil moisture and temperature. A mesocosm experiment was conducted with five prec...

Toll Facilities in the United States - Toll Facilities in the United States

Data.gov (United States)

Department of Transportation — Biennial report containing selected information on toll facilities in the United States that has been provided to FHWA by the States and/or various toll authorities...

Comparison of Dilute Acid and Ionic Liquid Pretreatment of Switchgrass: Biomass Recalcitrance, Delignification and Enzymatic Saccharification

Science.gov (United States)

The efficiency of two biomass pretreatment technologies, dilute acid hydrolysis and dissolution in an ionic liquid, are compared in terms of delignification, saccharification efficiency and saccharide yields with switchgrass serving as a model bioenergy crop. When subject to ionic liquid pretreatme...

Industrial hemp as a potential bioenergy crop in comparison with kenaf, switchgrass and biomass sorghum.

Science.gov (United States)

Das, Lalitendu; Liu, Enshi; Saeed, Areej; Williams, David W; Hu, Hongqiang; Li, Chenlin; Ray, Allison E; Shi, Jian

2017-11-01

This study takes combined field trial, lab experiment, and economic analysis approaches to evaluate the potential of industrial hemp in comparison with kenaf, switchgrass and biomass sorghum. Agronomy data suggest that the per hectare yield (5437kg) of industrial hemp stem alone was at a similar level with switchgrass and sorghum; while the hemp plants require reduced inputs. Field trial also showed that ∼1230kg/ha hemp grain can be harvested in addition to stems. Results show a predicted ethanol yield of ∼82gallons/dry ton hemp stems, which is comparable to the other three tested feedstocks. A comparative cost analysis indicates that industrial hemp could generate higher per hectare gross profit than the other crops if both hemp grains and biofuels from hemp stem were counted. These combined evaluation results demonstrate that industrial hemp has great potential to become a promising regional commodity crop for producing both biofuels and value-added products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Oil Vulnerabilities and United States Strategy

Science.gov (United States)

2007-02-08

Mazda, Mercedes - Benz , Ford, Mercury, and Nissan offer flexible fuel vehicles in the United States. Ethanol is currently produced in the United States...USAWC STRATEGY RESEARCH PROJECT OIL VULNERABILITIES AND UNITED STATES STRATEGY by Colonel Shawn P. Walsh...Colleges and Schools, 3624 Market Street, Philadelphia, PA 19104, (215) 662-5606. The Commission on Higher Education is an institutional accrediting

Runoff, sediment, nitrogen, and phosphorus losses from agricultural land converted to sweetgum and switchgrass bioenergy feedstock production in north Alabama

Energy Technology Data Exchange (ETDEWEB)

Nyakatawa, E.Z.; Mays, D.A. [Alabama A and M University, Normal (United States). Department of Plant and Soil Science; Tolbert, V.R. [Oak Ridge National Laboratory, Oak Ridge, TN (United States). Bionergy Feedstock Development Project; Green, T.H.; Bingham, L. [Alabama A and M University, Normal (United States). Center for Forestry and Ecology

2006-07-15

Renewable energy sources such as bioenergy crops have significant potential as alternatives to fossil fuels. Potential environmental problems arising from soil sediment and nutrient losses in runoff water from bioenergy crops need to be evaluated in order to determine the sustainability and overall feasibility of implementing bioenergy development strategies. This paper discusses runoff, sediment, N, and total P losses from agricultural land (continuous cotton (Gossypium hirsutum L.)) converted to short-rotation sweetgum (Liquidamber styraciflua L.) plantations with and without fescue (Festuca elatior L.) and switchgrass (Panicum virgatum L.) bioenergy crops, compared to corn (Zea mays L.), on a Decatur silt loam soil in north Alabama, from 1995 to 1999. Runoff volume was significantly correlated to total rainfall and sediment yield in each year, but treatment differences were not significant. Sweetgum plots produced the highest mean sediment yield of up to 800kgha{sup -1}compared to corn and switchgrass plots, which averaged less than 200kgha{sup -1}. Runoff NH{sub 4}{sup +} N losses averaged over treatments and years for spring season (3.1kgha{sup -1}) were three to five times those for summer, fall, and winter seasons. Runoff NO{sub 3}{sup -} N for no-till corn and switchgrass plots in spring and summer were five to ten times that for sweetgum plots. No-till corn and switchgrass treatments had 2.4 and 2.1kgha{sup -1} average runoff total P, respectively, which were two to three times that for sweetgum treatments. Growing sweetgum with a fescue cover crop provides significantly lower risk of water pollution from sediment, runoff NH{sub 4}{sup +} N, and NO{sub 3}{sup -} N. (author)

Genome-size Variation in Switchgrass (Panicum virgatum: Flow Cytometry and Cytology Reveal Rampant Aneuploidy

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Denise E. Costich

2010-11-01

Full Text Available Switchgrass ( L., a native perennial dominant of the prairies of North America, has been targeted as a model herbaceous species for biofeedstock development. A flow-cytometric survey of a core set of 11 primarily upland polyploid switchgrass accessions indicated that there was considerable variation in genome size within each accession, particularly at the octoploid (2 = 8 = 72 chromosome ploidy level. Highly variable chromosome counts in mitotic cell preparations indicated that aneuploidy was more common in octoploids (86.3% than tetraploids (23.2%. Furthermore, the incidence of hyper- versus hypoaneuploidy is equivalent in tetraploids. This is clearly not the case in octoploids, where close to 90% of the aneuploid counts are lower than the euploid number. Cytogenetic investigation using fluorescent in situ hybridization (FISH revealed an unexpected degree of variation in chromosome structure underlying the apparent genomic instability of this species. These results indicate that rapid advances in the breeding of polyploid biofuel feedstocks, based on the molecular-genetic dissection of biomass characteristics and yield, will be predicated on the continual improvement of our understanding of the cytogenetics of these species.

Pyrolysis and Combustion Kinetics of Raw and Carbonized Cottonwood and Switchgrass Agroforests

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Sammy Sadaka

2015-06-01

Full Text Available Raw biomass is not commonly suitable as feedstock for existing power plants, mainly because of the substantial required infrastructural changes. As a result, most raw feedstock requires pre-treatment to improve its physical and thermal characteristics. Biomass carbonization is one of the pre-treatments that produces charcoal-like feedstock. This paper explores the effects of the carbonization process on the physiochemical characteristics of biomass produced from two cottonwood clones, S7C20 and ST66, and switchgrass (var. Alamo. Additionally, it studies the thermal degradation kinetics of raw and carbonized agroforestry products in nitrogen and air environments. Feedstock samples were carbonized in a batch reactor at 400 °C in an oxygen-free environment for 2 hours. Carbonization decreased biomass bulk density, moisture content, and volatile solids while increasing fixed carbon, ash content, pH, and heating values. The heating value of S7C20, ST66, and switchgrass increased by 58.6%, 60.3%, and 69.7%, respectively. Carbonization increased the activation energy values under the condition of pyrolysis and decreased these values under the condition of combustion. The carbonization process produced a charcoal-like feedstock that may be processed with coal or even replace it.

Integrated energy, environmental and financial analysis of ethanol production from cellulosic switchgrass

International Nuclear Information System (INIS)

Felix, Erika; Tilley, David R.

2009-01-01

Ethanol production from cellulosic sources such as switchgrass (Panicum virgatum L.) requires the use of natural resources, fossil fuels, electricity, and human-derived goods and services. We used emergy accounting to integrate the ultimate amount of environmental, fossil fuel, and human-derived energy required to produce ethanol from switchgrass. Emergy is the total amount of energy of one form required directly and indirectly to make another form of energy. Forty-four percent of required emergy came from the environment either directly or embodied in purchased goods, 30% came from fossil fuels either directly or embodied in purchased goods, and 25% came from human-derived services indirectly. Ethanol production per petroleum use (emergy/emergy) was 4.0-to-1 under our Baseline Scenario, but dropped to 0.5-to-1 under a scenario that assumed higher input prices, lower conversion efficiencies and less waste recycling. At least 75% of total emergy was from non-renewable sources. Energy 'hidden' in indirect paths such as goods and services was 65% of the total. Cellulosic-ethanol is not a primary fuel source that substitutes for petroleum because its production relies heavily on non-renewable energy and purchased inputs. It is a means for converting natural resources to liquid fuel. (author)

31 CFR 596.313 - United States person.

Science.gov (United States)

2010-07-01

... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY TERRORISM LIST GOVERNMENTS SANCTIONS REGULATIONS General Definitions § 596.313 United States person. The term United States person means any United States...

Nuclear development in the United States

International Nuclear Information System (INIS)

Brewer, S.

1983-01-01

The history of the nuclear development in the United States has been one of international cooperation relations so far. The United States is to offer the technical information on atomic energy utilization to foreign countries in exchange for the guarantee that they never attempt to have or develop nuclear weapons. Actually, the United States has supplied the technologies on nuclear fuel cycle and other related fields to enable other countries to achieve economical and social progress. The Department of Energy clarified the public promise of the United States regarding the idea of international energy community. The ratio of nuclear power generation to total electric power supply in the United States exceeded 12%, and will exceed 20% by 1990. Since 1978, new nuclear power station has not been ordered, and some of the contracted power stations were canceled. The atomic energy industry in the United States prospered at the beginning of 1970s, but lost the spirit now, mainly due to the institutional problems rather than the technical ones. As the policy of the government to eliminate the obstacles, the improvement of the procedure for the permission and approval, the establishment of waste disposal capability, the verification of fast breeder reactor technology and the promotion of commercial fuel reprocessing were proposed. The re-establishment of the United States as the reliable supplier of atomic energy service is the final aim. (Kako, I.)

A trial of the suitability of switchgrass and reed canary grass as biofuel crops under UK conditions. 5th interim report March 2005

Energy Technology Data Exchange (ETDEWEB)

Richie, A.B.

2005-07-01

The Topgrass Project, established in 2002, investigated the potential of miscanthus, switchgrass and reed canary grass as biofuel crops at various sites in the UK. This interim report covers the period from the harvesting in winter 2003/04 to the harvesting in winter 2004/05. The report gives details on (i) pest and weed control and (ii) yields and associated costs per species per unit area. It was concluded that maximum potential yield has not been reached at some sites. The study was funded by the DTI and carried out by IACR Rothamstead with ADAS Consulting, Duchy College Cornwall and SCRI Invergowrie as collaborators. The project has now terminated.

78 FR 70274 - United States Travel and Tourism Advisory Board: Meeting of the United States Travel and Tourism...

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2013-11-25

... DEPARTMENT OF COMMERCE International Trade Administration United States Travel and Tourism Advisory Board: Meeting of the United States Travel and Tourism Advisory Board AGENCY: International Trade... the schedule and agenda for an open meeting of the United States Travel and Tourism Advisory Board...

78 FR 3398 - United States Travel and Tourism Advisory Board: Meeting of the United States Travel and Tourism...

Science.gov (United States)

2013-01-16

... DEPARTMENT OF COMMERCE International Trade Administration United States Travel and Tourism Advisory Board: Meeting of the United States Travel and Tourism Advisory Board AGENCY: International Trade... the schedule and agenda for an open meeting of the United States Travel and Tourism Advisory Board...

The PIN1 family gene PvPIN1 is involved in auxin-dependent root emergence and tillering in switchgrass

Directory of Open Access Journals (Sweden)

Kaijie Xu

2016-03-01

Full Text Available Abstract Switchgrass (Panicum virgatum L.; family Poaceae is a warm-season C4 perennial grass. Tillering plays an important role in determining the morphology of aboveground parts and the final biomass yield of switchgrass. Auxin distribution in plants can affect a variety of important growth and developmental processes, including the regulation of shoot and root branching, plant resistance and biological yield. Auxin transport and gradients in plants are mediated by influx and efflux carriers. PvPIN1, a switchgrass PIN1-like gene that is involved in regulating polar transport, is a putative auxin efflux carrier. Neighbor-joining analysis using sequences deposited in NCBI databases showed that the PvPIN1gene belongs to the PIN1 family and is evolutionarily closer to the Oryza sativa japonica group. Tiller emergence and development was significantly promoted in plants subjected toPvPIN1 RNA interference (RNAi, which yielded a phenotype similar to that of wild-type plants treated with the auxin transport inhibitor TIBA (2,3,5-triiodobenzoic acid. A transgenic approach that inducedPvPIN1 gene overexpression or suppression altered tiller number and the shoot/root ratio. These data suggest that PvPIN1plays an important role in auxin-dependent adventitious root emergence and tillering.

Effect of acid, steam explosion, and size reduction pretreatments on bio-oil production from sweetgum, switchgrass, and corn stover.

Science.gov (United States)

Wang, Hui; Srinivasan, Radhakrishnan; Yu, Fei; Steele, Philip; Li, Qi; Mitchell, Brian; Samala, Aditya

2012-05-01

Bio-oil produced from biomass by fast pyrolysis has the potential to be a valuable substitute for fossil fuels. In a recent work on pinewood, we found that pretreatment alters the structure and chemical composition of biomass, which influence fast pyrolysis. In this study, we evaluated dilute acid, steam explosion, and size reduction pretreatments on sweetgum, switchgrass, and corn stover feedstocks. Bio-oils were produced from untreated and pretreated feedstocks in an auger reactor at 450 °C. The bio-oil's physical properties of pH, water content, acid value, density, and viscosity were measured. The chemical characteristics of the bio-oils were determined by gas chromatography-mass spectrometry. The results showed that bio-oil yield and composition were influenced by the pretreatment method and feedstock type. Bio-oil yields of 52, 33, and 35 wt% were obtained from medium-sized (0.68-1.532 mm) untreated sweetgum, switchgrass, and corn stover, respectively, which were higher than the yields from other sizes. Bio-oil yields of 56, 46, and 51 wt% were obtained from 1% H(2)SO(4)-treated medium-sized sweetgum, switchgrass, and corn stover, respectively, which were higher than the yields from untreated and steam explosion treatments.

United States housing, 2012

Science.gov (United States)

Delton Alderman

2013-01-01

Provides current and historical information on housing market in the United States. Information includes trends for housing permits and starts, housing completions for single and multifamily units, and sales and construction. This report will be updated annually.

Economic potential for switchgrass production in the U.S. Northern Plains: A minimum-data analysis

Science.gov (United States)

There is a demand for timely information to support policy decision making. There is also interest in the potential for alternative crops such as switchgrass to be used for ethanol production and which would have a positive impact on net greenhouse gas emission. This paper uses a new minimum-data mo...

A management guide for planting and production of switchgrass as a biomass crop in Europe

NARCIS (Netherlands)

Elbersen, H.W.; Christian, D.G.; Bassam, N.E.; Sauerbeck, G.; Alexopoulou, E.; Sharma, N.; Piscioneri, I.

2004-01-01

Switchgrass is a perennial C4 grass native to North America, where it occurs naturally from 55º N latitude to deep into Mexico. It is used for soil conservation, forage production, as an ornamental grass and more recently as a biomass crop for ethanol, fibre, electricity and heat production. As

Are Agrofuels a conservation threat or opportunity for grassland birds in the United States?

Science.gov (United States)

Robertson, Bruce A.; Rice, Robert A.; Ribic, Christine; Babcock, Bruce A.; Landis, Douglas A.; Herkert, James R.; Fletcher, Robert J.; Fontaine, Joseph J; Doran, Patrick J.; Schemske, Douglas W.

2012-01-01

In the United States, government-mandated growth in the production of crops dedicated to biofuel (agrofuels) is predicted to increase the demands on existing agricultural lands, potentially threatening the persistence of populations of grassland birds they support. We review recently published literature and datasets to (1) examine the ability of alternative agrofuel crops and their management regimes to provide habitat for grassland birds, (2) determine how crop placement in agricultural landscapes and agrofuel-related land-use change will affect grassland birds, and (3) identify critical research and policy-development needs associated with agrofuel production. We find that native perennial plants proposed as feedstock for agrofuel (switchgrass, Panicum virgatum, and mixed grass—forb prairie) have considerable potential to provide new habitat to a wide range of grassland birds, including rare and threatened species. However, industrialization of agrofuel production that maximizes biomass, homogenizes vegetation structure, and results in the cultivation of small fields within largely forested landscapes is likely to reduce species richness and/or abundance of grassland-dependent birds. Realizing the potential benefits of agrofuel production for grassland birds' conservation will require the development of new policies that encourage agricultural practices specifically targeting the needs of grassland specialists. The broad array of grower-incentive programs in existence may deliver new agrofuel policies effectively but will require coordination at a spatial scale broader than currently practiced, preferably within an adaptive-management framework.

Rheology of transgenic switchgrass reveals practical aspects of biomass processing.

Science.gov (United States)

Wan, Guigui; Frazier, Taylor; Jorgensen, Julianne; Zhao, Bingyu; Frazier, Charles E

2018-01-01

Mechanical properties of transgenic switchgrass have practical implications for biorefinery technologies. Presented are fundamentals for simple (thermo)mechanical measurements of genetically transformed switchgrass. Experimental basics are provided for the novice, where the intention is to promote collaboration between plant biologists and materials scientists. Stem sections were subjected to two stress modes: (1) torsional oscillation in the linear response region, and (2) unidirectional torsion to failure. Specimens were analyzed while submerged/saturated in ethylene glycol, simulating natural hydration and allowing experimental temperatures above 100 °C for an improved view of the lignin glass transition. Down-regulation of the 4-Coumarate:coenzyme A ligase gene (reduced lignin content and altered monomer composition) generally resulted in less stiff and weaker stems. These observations were associated with a reduction in the temperature and activation energy of the lignin glass transition, but surprisingly with no difference in the breadth and intensity of the tan  δ signal. The results showed promise in further investigations of how rheological methods relate to stem lignin content, composition, and functional properties in the field and in bioprocessing. Measurements such as these are complicated by small specimen size; however, torsional rheometers (relatively common in polymer laboratories) are well suited for this task. As opposed to the expense and complication of relative humidity control, solvent-submersion rheological methods effectively reveal fundamental structure/property relationships in plant tissues. Demonstrated are low-strain linear methods, and also nonlinear yield and failure analysis; the latter is very uncommon for typical rheological equipment.

31 CFR 500.520 - Payments from accounts of United States citizens in employ of United States in foreign countries...

Science.gov (United States)

2010-07-01

... States citizens in employ of United States in foreign countries and certain other persons. 500.520..., Authorizations and Statements of Licensing Policy § 500.520 Payments from accounts of United States citizens in employ of United States in foreign countries and certain other persons. (a) Banking institutions within...

31 CFR 515.520 - Payments from accounts of United States citizens in employ of United States in foreign countries...

Science.gov (United States)

2010-07-01

... States citizens in employ of United States in foreign countries and certain other persons. 515.520..., Authorizations, and Statements of Licensing Policy § 515.520 Payments from accounts of United States citizens in employ of United States in foreign countries and certain other persons. (a) Banking institutions within...

The trade-off between bioenergy and emissions with land constraints

International Nuclear Information System (INIS)

Kauffman, Nathan S.; Hayes, Dermot J.

2013-01-01

Agricultural biofuels require the use of scarce land, and this land has opportunity cost. We explore the objective function of a social planner who includes a land constraint in the optimization decision to minimize environmental cost. The inclusion of this land constraint in our optimization model motivates the measurement of emissions on a per-hectare basis. Switchgrass and corn are modeled as competing alternatives to show how the inclusion of a land constraint can influence life cycle rankings and alter policy conclusions. With land use unconstrained, ethanol produced from switchgrass is always an optimal feedstock relative to ethanol produced from corn. With land use constrained, however, our results show that it is unlikely that switchgrass would be optimal in the midwestern United States, but may be optimal in southern states if carbon is priced relatively high. Whether biofuel policy advocates for one feedstock over another should consider these contrasting results. - Highlights: ► Biofuel pathway rankings differ depending on the functional unit of measure. ► Conventional life cycle analysis overlooks the opportunity cost of land. ► Including a land constraint, a model is developed to determine pathway optimality. ► The optimization model suggests emissions be measured per hectare. ► Switchgrass and corn are modeled as competing alternatives for biofuel production

TRAINING OF THE STATE PRESIDENT'S UNIT

African Journals Online (AJOL)

The primary function of the State President's Unit is to protect the head of state - not his person as is generally believed, but his authority over the state. Ironically, the ceremonial performances of the State President's Unit lead people to believe that they are only capable of doing drill exer- cises. However, upon investigating.

Effect of topsoil thickness on soil water infiltration in corn-soybean rotation and switchgrass production systems

Science.gov (United States)

Switchgrass and corn are sometimes used as a resource for biofuel production. The effect of production management systems on water infiltration is very critical in claypan landscape to increase production as well as minimize economic and environmental risks. The objective of this study was to evalua...

Effects of precipitation changes on aboveground net primary production and soil respiration in a switchgrass field

Science.gov (United States)

This study attempted to test whether switchgrass aboveground net primary production (ANPP) responds to precipitation (PPT) changes in a double asymmetry pattern as framed by Knapp et al. (2016), and whether it is held true for other ecosystem processes such as soil respiration (SR). Data were colle...

Switchgrass storage effects on the recovery of carbohydrates after liquid hot water pretreatment and enzymatic hydrolysis

Directory of Open Access Journals (Sweden)

Danielle Julie Carrier

2016-08-01

Full Text Available Perennial grasses that would be used for bioenergy and bioproducts production will need to be stored for various periods of time to ensure a continual feedstock supply to a bioprocessing facility. The effects of storage practices on grass composition and the response of grasses to subsequent bioprocesses such as pretreatment and enzymatic hydrolysis needs to be understood to develop the most efficient storage protocols. This study examined the effect of outdoor storage of round switchgrass bales on composition before and after liquid hot water pretreatment (LHW and enzymatic hydrolysis. This study also examined the effect of washing LHW pretreated biomass prior to enzymatic hydrolysis. It was determined that switchgrass composition after baling was stable. As expected, glucan and lignin contents increased after LHW due to decreases in xylan and galactan. Washing biomass prior to enzymatic hydrolysis reduced saccharification, especially in samples from the interior of the bale, by at least 5%.

Phytoremediation of biosolids from an end-of-life municipal lagoon using cattail (Typha latifolia L.) and switchgrass (Panicum virgatum L.).

Science.gov (United States)

Jeke, Nicholson N; Hassan, Adenike O; Zvomuya, Francis

2017-03-04

Land spreading of biosolids as a disposal option is expensive and can disperse pathogens and contaminants in the environment. This growth room study examined phytoremediation using switchgrass (Panicum virgatum L.) and cattail (Typha latifolia L.) as an alternative to land spreading of biosolids. Seedlings were transplanted into pots containing 3.9 kg of biosolids (dry wt.). Aboveground biomass (AGB) was harvested either once or twice during each 90-day growth period. Switchgrass AGB yield was greater with two harvests than with one harvest during the first 90-day growth period, whereas cattail yield was not affected by harvest frequency. In the second growth period, harvesting frequency did not affect the yield of either plant species. However, repeated harvesting significantly improved nitrogen (N) and phosphorus (P) uptake by both plants in the first period. Phytoextraction of P was significantly greater for switchgrass (3.9% of initial biosolids P content) than for cattail (2.8%), while plant species did not have a significant effect on N phytoextraction. The trace element accumulation in the AGB of both plant species was negligible. Phytoextraction rates attained in this study suggest that phytoremediation can effectively remove P from biosolids and offers a potentially viable alternative to the disposal of biosolids on agricultural land.

Survival of Salmonella, Escherichia coli 0157:H7, non-0157 shiga toxin producing E.coli, and potential surrogate bacteria in crop soil as affected by the addition of fast pyrolysis-generated switchgrass biochar

Science.gov (United States)

Fast pyrolysis of switchgrass (and resultant biochar) can be used for bio-fuel production, soil amendments for fertilizing crops, binding heavy metals, and sequestering environmental biocarbon. To determine the influence of fast pyrolysis-generated switchgrass biochar on survival of foodborne path...

Selection signatures in four lignin genes from switchgrass populations divergently selected for in vitro dry matter digestibility

Science.gov (United States)

Switchgrass is undergoing development as a dedicated cellulosic bioenergy crop. Fermentation of lignocellulosic biomass to ethanol in a bioenergy system, or to volatile fatty acids in a livestock production system, is strongly and negatively influenced by lignification of cell walls. This study dete...

Greenhouse gas fluxes and root productivity in a switchgrass and loblolly pine intercropping system for bioenergy production

Science.gov (United States)

Paliza Shrestha; John R. Seiler; Brian D. Strahm; Eric B. Sucre; Zakiya H. Leggett

2015-01-01

This study is part of a larger collaborative effort to determine the overall environmental sustainability of intercropping pine (Pinus taeda L.) and switchgrass (Panicum virgatum L.), both of which are promising feedstock for bioenergy production in the Lower Coastal Plain in North Carolina.

31 CFR 515.334 - United States national.

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2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States national. 515.334 Section 515.334 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... of the United States, and which has its principal place of business in the United States. [61 FR...

7 CFR 1212.32 - United States Customs Service.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States Customs Service. 1212.32 Section 1212... § 1212.32 United States Customs Service. “United States Customs Service” or “Customs” means the United States Customs and Border Protection, an agency of the Department of Homeland Security. Honey Packers and...

Temporal dynamics of fibrolytic and methanogenic rumen microorganisms during in situ incubation of switchgrass determined by 16S rRNA gene profiling.

Science.gov (United States)

Piao, Hailan; Lachman, Medora; Malfatti, Stephanie; Sczyrba, Alexander; Knierim, Bernhard; Auer, Manfred; Tringe, Susannah G; Mackie, Roderick I; Yeoman, Carl J; Hess, Matthias

2014-01-01

The rumen microbial ecosystem is known for its biomass-degrading and methane-producing phenotype. Fermentation of recalcitrant plant material, comprised of a multitude of interwoven fibers, necessitates the synergistic activity of diverse microbial taxonomic groups that inhabit the anaerobic rumen ecosystem. Although interspecies hydrogen (H2) transfer, a process during which bacterially generated H2 is transferred to methanogenic Archaea, has obtained significant attention over the last decades, the temporal variation of the different taxa involved in in situ biomass-degradation, H2 transfer and the methanogenesis process remains to be established. Here we investigated the temporal succession of microbial taxa and its effect on fiber composition during rumen incubation using 16S rRNA amplicon sequencing. Switchgrass filled nylon bags were placed in the rumen of a cannulated cow and collected at nine time points for DNA extraction and 16S pyrotag profiling. The microbial community colonizing the air-dried and non-incubated (0 h) switchgrass was dominated by members of the Bacilli (recruiting 63% of the pyrotag reads). During in situ incubation of the switchgrass, two major shifts in the community composition were observed: Bacilli were replaced within 30 min by members belonging to the Bacteroidia and Clostridia, which recruited 34 and 25% of the 16S rRNA reads generated, respectively. A second significant shift was observed after 16 h of rumen incubation, when members of the Spirochaetes and Fibrobacteria classes became more abundant in the fiber-adherent community. During the first 30 min of rumen incubation ~13% of the switchgrass dry matter was degraded, whereas little biomass degradation appeared to have occurred between 30 min and 4 h after the switchgrass was placed in the rumen. Interestingly, methanogenic members of the Euryarchaeota (i.e., Methanobacteria) increased up to 3-fold during this period of reduced biomass-degradation, with peak abundance just

Nuclear power in the United States

International Nuclear Information System (INIS)

Johnston, J.B.

1985-01-01

All over the world except in the United States, nuclear energy is a low cost, secure, environmentally acceptable form of energy. In the United States, civilian nuclear power is dead. 112 nuclear power plants have been abandoned or cancelled in the last decade, and there has been no new order for nuclear plants since 1978. It will be fortunate to have 125 operating nuclear plants in the United States in the year 2000. There are almost 90 completed nuclear power plants and about 45 under construction in the United States, but several of those under construction will eventually be abandoned. About 20 % of the electricity in the United States will be generated by nuclear plants in 2000 as compared with 13 % supplied in the last year. Under the present regulatory and institutional arrangement, American electric utilities would not consider to order a new nuclear power plant. Post-TMI nuclear plants became very expensive, and there is also ideological opposition to nuclear power. Coal-firing plants are also in the similar situation. The uncertainty about electric power demand, the cost of money, the inflation of construction cost and regulation caused the situation. (Kako, I.)

Bioenergy Crop Production in the United States. Potential Quantities, Land Use Changes, and Economic Impacts on the Agricultural Sector

International Nuclear Information System (INIS)

Walsh, Marie E.; Torre Ugarte, D.G. de la; Shapouri, H.; Slinsky, S.P.

2003-01-01

The U.S. Departments of Agriculture and Energy jointly analyzed the economic potential for, and impacts of, large-scale bioenergy crop production in the United States. An agricultural sector model (POLYSYS) was modified to include three potential bioenergy crops (switchgrass, hybrid poplar, and willow). At farmgate prices of US $2.44/GJ, an estimated 17 million hectares of bioenergy crops, annually yielding 171 million dry Mg of biomass, could potentially be produced at a profit greater than existing agricultural uses for the land. The estimate assumes high productivity management practices are permitted on Conservation Reserve Program lands. Traditional crops prices are estimated to increase 9 to 14 percent above baseline prices and farm income increases annually by US $6.0 billion above baseline. At farmgate prices of US $1.83/GJ, an estimated 7.9 million hectares of bioenergy crops, annually yielding 55 million dry Mg of biomass, could potentially be produced at a profit greater than existing agricultural uses for the land. The estimate assumes management practices intended to achieve high environmental benefits on Conservation Reserve Program lands. Traditional crops prices are estimated to increase 4 to 9 percent above baseline prices and farm income increases annually by US $2.8 billion above baseline

Teen Pregnancy in the United States

Science.gov (United States)

... United States: the contribution of abstinence and improved contraceptive use. Am J Public Health. 2007;97(1):150-6. Lindberg LD, Santelli JS, Desai, S. Understanding the Decline in Adolescent Fertility in the United States, 2007–2012. J ...

The economical and environmental performance of miscanthus and switchgrass production and supply chains in a European setting

NARCIS (Netherlands)

Smeets, E.M.W.; Lewandowski, I.M.; Faaij, A.P.C.

2009-01-01

The purpose of this study is to analyse the economical and environmental performance of switchgrass and miscanthus production and supply chains in the European Union (EU25), for the years 2004 and 2030. The environmental performance refers to the greenhouse gas (GHG) emissions, the primary fossil

Immigration Enforcement Within the United States

Science.gov (United States)

2006-04-06

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Policy Issues...Remained in the United States, (Washington: Center for Immigration Studies, May 2002). Immigration Enforcement Within the United States Introduction ...interior enforcement lack a border component. For example, fugitive taskforces, investigations of alien slavery and sweatshops , and employer sanctions do

Factors affecting polyhydroxybutyrate accumulation in mesophyll cells of sugarcane and switchgrass

Science.gov (United States)

2014-01-01

Background Polyhydroxyalkanoates are linear biodegradable polyesters produced by bacteria as a carbon store and used to produce a range of bioplastics. Widespread polyhydroxyalkanoate production in C4 crops would decrease petroleum dependency by producing a renewable supply of biodegradable plastics along with residual biomass that could be converted into biofuels or energy. Increasing yields to commercial levels in biomass crops however remains a challenge. Previously, lower accumulation levels of the short side chain polyhydroxyalkanoate, polyhydroxybutyrate (PHB), were observed in the chloroplasts of mesophyll (M) cells compared to bundle sheath (BS) cells in transgenic maize (Zea mays), sugarcane (Saccharum sp.), and switchgrass (Panicum virgatum L.) leading to a significant decrease in the theoretical yield potential. Here we explore various factors which might affect polymer accumulation in mesophyll cells, including targeting of the PHB pathway enzymes to the mesophyll plastid and their access to substrate. Results The small subunit of Rubisco from pea effectively targeted the PHB biosynthesis enzymes to both M and BS chloroplasts of sugarcane and switchgrass. PHB enzyme activity was retained following targeting to M plastids and was equivalent to that found in the BS plastids. Leaf total fatty acid content was not affected by PHB production. However, when fatty acid synthesis was chemically inhibited, polymer accumulated in M cells. Conclusions In this study, we provide evidence that access to substrate and neither poor targeting nor insufficient activity of the PHB biosynthetic enzymes may be the limiting factor for polymer production in mesophyll chloroplasts of C4 plants. PMID:25209261

Modeling state-level soil carbon emission factors under various scenarios for direct land use change associated with United States biofuel feedstock production

International Nuclear Information System (INIS)

Kwon, Ho-Young; Mueller, Steffen; Dunn, Jennifer B.; Wander, Michelle M.

2013-01-01

Current estimates of life cycle greenhouse gas emissions of biofuels produced in the US can be improved by refining soil C emission factors (EF; C emissions per land area per year) for direct land use change associated with different biofuel feedstock scenarios. We developed a modeling framework to estimate these EFs at the state-level by utilizing remote sensing data, national statistics databases, and a surrogate model for CENTURY's soil organic C dynamics submodel (SCSOC). We estimated the forward change in soil C concentration within the 0–30 cm depth and computed the associated EFs for the 2011 to 2040 period for croplands, grasslands or pasture/hay, croplands/conservation reserve, and forests that were suited to produce any of four possible biofuel feedstock systems [corn (Zea Mays L)-corn, corn–corn with stover harvest, switchgrass (Panicum virgatum L), and miscanthus (Miscanthus × giganteus Greef et Deuter)]. Our results predict smaller losses or even modest gains in sequestration for corn based systems, particularly on existing croplands, than previous efforts and support assertions that production of perennial grasses will lead to negative emissions in most situations and that conversion of forest or established grasslands to biofuel production would likely produce net emissions. The proposed framework and use of the SCSOC provide transparency and relative simplicity that permit users to easily modify model inputs to inform biofuel feedstock production targets set forth by policy. -- Highlights: ► We model regionalized feedstock-specific United States soil C emission factors. ► We simulate soil C changes from direct land use change associated with biofuel feedstock production. ► Corn, corn-stover, and perennial grass biofuel feedstocks grown in croplands maintain soil C levels. ► Converting grasslands to bioenergy crops risks soil C loss. ► This modeling framework yields more refined soil C emissions than national-level emissions

Comparative relationships and chromosome evolution in switchgrass (Panicum virgatum) and its genomic model, foxtail millet (Setaria italica)

Science.gov (United States)

A switchgrass (Panicum virgatum L.) consensus map was developed that combined data from two mapping populations and integrated recombination data from both parents of this largely obligate outcrossing species. The consensus map consisted of 1,321 loci and spanned 2,122 cM. An analysis of the distri...

United States advanced technologies

International Nuclear Information System (INIS)

Longenecker, J.R.

1985-01-01

In the United States, the advanced technologies have been applied to uranium enrichment as a means by which it can be assured that nuclear fuel cost will remain competitive in the future. The United States is strongly committed to the development of advanced enrichment technology, and has brought both advanced gas centrifuge (AGC) and atomic vapor laser isotope separation (AVLIS) programs to a point of significant technical refinement. The ability to deploy advanced technologies is the basis for the confidence in competitive future price. Unfortunately, the development of advanced technologies is capital intensive. The year 1985 is the key year for advanced technology development in the United States, since the decision on the primary enrichment technology for the future, AGC or AVLIS, will be made shortly. The background on the technology selection process, the highlights of AGC and AVLIS programs and the way to proceed after the process selection are described. The key objective is to maximize the sales volume and minimize the operating cost. This will help the utilities in other countries supply low cost energy on a reliable, long term basis. (Kako, I.)

Anaerobic decomposition of switchgrass by tropical soil-derived feedstock-adapted consortia.

Science.gov (United States)

DeAngelis, Kristen M; Fortney, Julian L; Borglin, Sharon; Silver, Whendee L; Simmons, Blake A; Hazen, Terry C

2012-01-01

Tropical forest soils decompose litter rapidly with frequent episodes of anoxic conditions, making it likely that bacteria using alternate terminal electron acceptors (TEAs) play a large role in decomposition. This makes these soils useful templates for improving biofuel production. To investigate how TEAs affect decomposition, we cultivated feedstock-adapted consortia (FACs) derived from two tropical forest soils collected from the ends of a rainfall gradient: organic matter-rich tropical cloud forest (CF) soils, which experience sustained low redox, and iron-rich tropical rain forest (RF) soils, which experience rapidly fluctuating redox. Communities were anaerobically passed through three transfers of 10 weeks each with switchgrass as a sole carbon (C) source; FACs were then amended with nitrate, sulfate, or iron oxide. C mineralization and cellulase activities were higher in CF-FACs than in RF-FACs. Pyrosequencing of the small-subunit rRNA revealed members of the Firmicutes, Bacteroidetes, and Alphaproteobacteria as dominant. RF- and CF-FAC communities were not different in microbial diversity or biomass. The RF-FACs, derived from fluctuating redox soils, were the most responsive to the addition of TEAs, while the CF-FACs were overall more efficient and productive, both on a per-gram switchgrass and a per-cell biomass basis. These results suggest that decomposing microbial communities in fluctuating redox environments are adapted to the presence of a diversity of TEAs and ready to take advantage of them. More importantly, these data highlight the role of local environmental conditions in shaping microbial community function that may be separate from phylogenetic structure. After multiple transfers, we established microbial consortia derived from two tropical forest soils with different native redox conditions. Communities derived from the rapidly fluctuating redox environment maintained a capacity to use added terminal electron acceptors (TEAs) after multiple

The United States and the Arab Gulf Monarchies

International Nuclear Information System (INIS)

Kechichian, J.A.

1999-01-01

The United States has enduring strategic interests in the Persian Gulf region. To understand these interests and the Usa policy towards the Arab Gulf Monarchies, the french institute of international relations (IFRI) proposes this document. The following chapters are detailed: the United States and the Arab Gulf Monarchies, overview, Chief Unites States Objective: Access to oil, re-evaluating United States Foreign Policy in the Gulf, the second term (Usa strategy). (A.L.B.)

Bio-remediation of Pb and Cd polluted soils by switchgrass: A case study in India.

Science.gov (United States)

Arora, Kalpana; Sharma, Satyawati; Monti, Andrea

2016-01-01

In the present study bioremediation potential of a high biomass yielding grass, Panicum virgatum (switchgrass), along with plant associated microbes (AM fungi and Azospirillum), was tested against lead and cadmium in pot trials. A pot trial was set up in order to evaluate bioremediation efficiency of P. virgatum in association with PAMs (Plant Associated Microbes). Growth parameters and bioremediation potential of endomycorrhizal fungi (AMF) and Azospirillum against different concentrations of Pb and Cd were compared. AM fungi and Azospirillum increased the root length, branches, surface area, and root and shoot biomass. The soil pH was found towards neutral with AMF and Azospirillum inoculations. The bioconcentration factor (BCF) for Pb (12 mg kg(-1)) and Cd (10 mg kg(-1)) were found to be 0.25 and 0.23 respectively and translocation index (Ti) was 17.8 and 16.7 respectively (approx 45% higher than control). The lower values of BCF and Ti, even at highest concentration of Pb and Cd, revealed the capability of switchgrass of accumulating high concentration of Pb and Cd in the roots, while preventing the translocation of Pb and Cd to aerial biomass.

78 FR 46686 - Privacy Act of 1974; Treasury/United States Mint .013-United States Mint National Electronic...

Science.gov (United States)

2013-08-01

... available publicly. FOR FURTHER INFORMATION CONTACT: For general questions and privacy issues, please... DEPARTMENT OF THE TREASURY Privacy Act of 1974; Treasury/United States Mint .013--United States... Privacy Act of 1974, as amended, 5 U.S.C. 552a, the Department of the Treasury (``Treasury'') and the...

39 CFR 221.1 - The United States Postal Service.

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2010-07-01

... 39 Postal Service 1 2010-07-01 2010-07-01 false The United States Postal Service. 221.1 Section 221.1 Postal Service UNITED STATES POSTAL SERVICE ORGANIZATION AND ADMINISTRATION GENERAL ORGANIZATION § 221.1 The United States Postal Service. The United States Postal Service was established as an...

UNITED STATES DURING THE COLD WAR 1945-1990

Directory of Open Access Journals (Sweden)

Novita Mujiyati

2016-02-01

Full Text Available United States and the Soviet Union is a country on the part of allies who emerged as the winner during World War II. However, after reaching the Allied victory in the situation soon changed, man has become an opponent. United States and the Soviet Union are competing to expand the influence and power. To compete the United States strive continuously strengthen itself both in the economic and military by establishing a defense pact and aid agencies in the field of economy. During the Cold War the two are not fighting directly in one of the countries of the former Soviet Union and the United States. However, if understood, teradinya the Korean War and the Vietnam War is a result of tensions between the two countries and is a direct warfare conducted by the United States and the Soviet Union. Cold War ended in conflict with the collapse of the Soviet Union and the United States emerged as the winner of the country.

78 FR 27857 - United States Standards for Wheat

Science.gov (United States)

2013-05-13

... RIN 0580-AB12 United States Standards for Wheat AGENCY: Grain Inspection, Packers and Stockyards... (GIPSA) is revising the United States Standards for Wheat under the United States Grain Standards Act (USGSA) to change the definition of Contrasting classes (CCL) in the class Hard White wheat. This change...

Tuberculosis along the United States-Mexico border, 1993-2001.

Science.gov (United States)

Schneider, Eileen; Laserson, Kayla F; Wells, Charles D; Moore, Marisa

2004-07-01

Tuberculosis (TB) is a leading public health problem and a recognized priority for the federal Governments of both Mexico and the United States of America. The objectives of this research, primarily for the four states in the United States that are along the border with Mexico, were to: (1) describe the epidemiological situation of TB, (2) identify TB risk factors, and (3) discuss tuberculosis program strategies. We analyzed tuberculosis case reports collected from 1993 through 2001 by the tuberculosis surveillance system of the United States. We used those data to compare TB cases mainly among three groups: (1) Mexican-born persons in the four United States border states (Arizona, California, New Mexico, and Texas), (2) persons in those four border states who had been born in the United States, and (3) Mexican-born persons in the 46 other states of the United States, which do not border Mexico. For the period from 1993 through 2001, of the 16 223 TB cases reported for Mexican-born persons in the United States, 12 450 of them (76.7%) were reported by Arizona, California, New Mexico, and Texas. In those four border states overall in 2001, tuberculosis case rates for Mexican-born persons were 5.0 times as high as the rates for persons born in the United States; those four states have 23 counties that directly border on Mexico, and the ratio in those counties was 5.8. HIV seropositivity, drug and alcohol use, unemployment, and incarceration were significantly less likely to be reported in Mexican-born TB patients from the four border states and the nonborder states than in patients born in the United States from the four border states (P pulmonary tuberculosis patients who were 18-64 years of age and residing in the four border states, the Mexican-born patients were 3.6 times as likely as the United States-born patients were to have resistance to at least isoniazid and rifampin (i. e., to have multidrug-resistant TB) and twice as likely to have isoniazid resistance

Global Entrepreneurship and the United States

Science.gov (United States)

2010-09-01

Global Entrepreneurship and the United States by Zoltan J. Acs Laszlo Szerb Ruxton, MD 21204 for under contract number SBAHQ-09...SUBTITLE Global Entrepreneurship and the United States 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...3 2.1. Assessing Entrepreneurship ..................................................................................4 2.2. Stages of Development

75 FR 25925 - United States Mint

Science.gov (United States)

2010-05-10

... Committee May 25, 2010 Public Meeting. SUMMARY: Pursuant to United States Code, Title 31, section 5135(b)(8... scheduled for May 25, 2010. Date: May 25, 2010. Time: 9 a.m. to 12 p.m. Location: 8th Floor Board Room, United States Mint, 801 9th Street, NW., Washington, DC 20220. Subject: Review and discuss obverse and...

31 CFR 515.330 - Person within the United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Person within the United States. 515... Definitions § 515.330 Person within the United States. (a) The term person within the United States, includes: (1) Any person, wheresoever located, who is a resident of the United States; (2) Any person actually...

45 CFR 212.7 - Repayment to the United States.

Science.gov (United States)

2010-10-01

... 45 Public Welfare 2 2010-10-01 2010-10-01 false Repayment to the United States. 212.7 Section 212... UNITED STATES CITIZENS RETURNED FROM FOREIGN COUNTRIES § 212.7 Repayment to the United States. (a) An..., any or all of the cost of such assistance to the United States, except insofar as it is determined...

20 CFR 416.215 - You leave the United States.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false You leave the United States. 416.215 Section... Eligible § 416.215 You leave the United States. You lose your eligibility for SSI benefits for any month during all of which you are outside of the United States. If you are outside of the United States for 30...

37 CFR 1.412 - The United States Receiving Office.

Science.gov (United States)

2010-07-01

... Information § 1.412 The United States Receiving Office. (a) The United States Patent and Trademark Office is a Receiving Office only for applicants who are residents or nationals of the United States of America. (b) The... “United States Receiving Office” or by the abbreviation “RO/US.” (c) The major functions of the Receiving...

Comparative Genomics in Switchgrass Using 61,585 High-Quality Expressed Sequence Tags

Directory of Open Access Journals (Sweden)

Christian M. Tobias

2008-11-01

Full Text Available The development of genomic resources for switchgrass ( L., a perennial NAD-malic enzyme type C grass, is required to enable molecular breeding and biotechnological approaches for improving its value as a forage and bioenergy crop. Expressed sequence tag (EST sequencing is one method that can quickly sample gene inventories and produce data suitable for marker development or analysis of tissue-specific patterns of expression. Toward this goal, three cDNA libraries from callus, crown, and seedling tissues of ‘Kanlow’ switchgrass were end-sequenced to generate a total of 61,585 high-quality ESTs from 36,565 separate clones. Seventy-three percent of the assembled consensus sequences could be aligned with the sorghum [ (L. Moench] genome at a -value of <1 × 10, indicating a high degree of similarity. Sixty-five percent of the ESTs matched with gene ontology molecular terms, and 3.3% of the sequences were matched with genes that play potential roles in cell-wall biogenesis. The representation in the three libraries of gene families known to be associated with C photosynthesis, cellulose and β-glucan synthesis, phenylpropanoid biosynthesis, and peroxidase activity indicated likely roles for individual family members. Pairwise comparisons of synonymous codon substitutions were used to assess genome sequence diversity and indicated an overall similarity between the two genome copies present in the tetraploid. Identification of EST–simple sequence repeat markers and amplification on two individual parents of a mapping population yielded an average of 2.18 amplicons per individual, and 35% of the markers produced fragment length polymorphisms.

The United States and the Kurds: Case Studies in United States Engagement

National Research Council Canada - National Science Library

Lambert, Peter

1997-01-01

..., between 1969- 1975, and 1990-1996. Both eras saw the United States able to influence events relating to the Kurds in support of a larger regional policy, only to find no easy solution to the Kurdish quest for autonomy...

Effect of alfalfa (medicago sativa) on fermentation profile and nutritive value of switchgrass (panicum virgatum) and bermudagrass (cynodon dactylon) silages

Science.gov (United States)

An experiment was conducted at the University of Kentucky Spindletop Farm in Lexington, Kentucky between October and November, 2009 to evaluate the effect of different percentages of alfalfa (Medicago sativa) as mixtures in switchgrass (Panicum virgatus) and bermudagrass (Cynodon dactylon) silages. ...

United States rejoin ITER

International Nuclear Information System (INIS)

Roberts, M.

2003-01-01

Upon pressure from the United States Congress, the US Department of Energy had to withdraw from further American participation in the ITER Engineering Design Activities after the end of its commitment to the EDA in July 1998. In the years since that time, changes have taken place in both the ITER activity and the US fusion community's position on burning plasma physics. Reflecting the interest in the United States in pursuing burning plasma physics, the DOE's Office of Science commissioned three studies as part of its examination of the option of entering the Negotiations on the Agreement on the Establishment of the International Fusion Energy Organization for the Joint Implementation of the ITER Project. These were a National Academy Review Panel Report supporting the burning plasma mission; a Fusion Energy Sciences Advisory Committee (FESAC) report confirming the role of ITER in achieving fusion power production, and The Lehman Review of the ITER project costing and project management processes (for the latter one, see ITER CTA Newsletter, no. 15, December 2002). All three studies have endorsed the US return to the ITER activities. This historical decision was announced by DOE Secretary Abraham during his remarks to employees of the Department's Princeton Plasma Physics Laboratory. The United States will be working with the other Participants in the ITER Negotiations on the Agreement and is preparing to participate in the ITA

United States Stateplane Zones - NAD83

Data.gov (United States)

Earth Data Analysis Center, University of New Mexico — U.S. State Plane Zones (NAD 1983) represents the State Plane Coordinate System (SPCS) Zones for the 1983 North American Datum within United States.

United States Stateplane Zones - NAD27

Data.gov (United States)

Earth Data Analysis Center, University of New Mexico — U.S. State Plane Zones (NAD 1927) represents the State Plane Coordinate System (SPCS) Zones for the 1927 North American Datum within United States.

Present state of electric power business in United States and Europe

International Nuclear Information System (INIS)

Onishi, Kenichi

2011-01-01

This article reported present state of nuclear power and electric power business in United States and Europe after Fukushima Daiichi Accident. As for the trend of demand and supply of electric power and policy, the accident forced Germany possibly to proceed with phase-out of nuclear power, but France and United States to sustain nuclear power with no great change of energy policy at this moment. As for the trend of electric power market, there was not state in United States with liberalized retail market of electric power after rolling blackouts occurred in California State in the early 2000s. In Germany proceeding with renewable energy introduction, renewable electricity fed into the grid was paid for by the network operators at fixed tariffs and the costs passed on to electricity consumers were increasing. Renewable Portfolio Standards (RPS) in United States forced the state to introduction of renewable energy to some ratio, and Feed-in Tariff (FIT) introduced in EU in 1990s lead to introduction of a large amount of renewable electricity targeted in 2020. Huge amount of wind power introduction brought about several problems to solve such that excess electric power above domestic demand had bad effects on grids in neighboring region. Enforcement of power transmission lines was also needed with increase of maximum electric power as well as introduction of a large amount of renewable electricity. (T. Tanaka)

Death in the United States, 2011

Science.gov (United States)

... Order from the National Technical Information Service NCHS Death in the United States, 2011 Recommend on Facebook ... 2011 SOURCE: National Vital Statistics System, Mortality. Do death rates vary by state? States experience different mortality ...

31 CFR 103.39 - Person outside the United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Person outside the United States. 103... Person outside the United States. For the purposes of this subpart, a remittance or transfer of funds, or... the United States, shall be deemed to be a remittance or transfer to a person outside the United...

Energy problems of the United States

International Nuclear Information System (INIS)

Pertuzio, A.

2006-01-01

The united states are the third world producer of oil which accounts for 440% of world production and 20 million barrels/day of which 60% are imported. That dependence on imports is likely to increase in the next decades. Such supplies and their security are therefore a fundamental factor of the United States foreign policy in combination with their political, economic and strategic objectives in a world both unsure and dangerous

Household pesticide usage in the United States.

Science.gov (United States)

Savage, E P; Keefe, T J; Wheeler, H W; Mounce, L; Helwic, L; Applehans, F; Goes, E; Goes, T; Mihlan, G; Rench, J; Taylor, D K

1981-01-01

A total of 10,000 U.S. households in 25 standard metropolitan statistical areas and 25 counties were included in the United States. More than 8,200 households granted an interview. Nine of every ten households in the United States used some types of pesticide in their house, garden, or yard. Households in the southeastern United States used the most pesticides. Although more than 500 different pesticide formulations were used by the sampled households, 15 pesticides accounted for 65.5% of all pesticides reported in this study. Thirteen of these 15 pesticides were insecticides, one was a herbicide, and one was a rodenticide.

75 FR 13345 - Pricing for Certain United States Mint Products

Science.gov (United States)

2010-03-19

... DEPARTMENT OF THE TREASURY United States Mint Pricing for Certain United States Mint Products AGENCY: United States Mint, Department of the Treasury. ACTION: Notice. SUMMARY: The United States Mint is announcing the price of First Spouse Bronze Medals and 2010 First Spouse Bronze Medal Series: Four...

22 CFR 22.3 - Remittances in the United States.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Remittances in the United States. 22.3 Section...-DEPARTMENT OF STATE AND FOREIGN SERVICE § 22.3 Remittances in the United States. (a) Type of remittance. Remittances shall be in the form of: (1) Check or bank draft drawn on a bank in the United States; (2) money...

The United Kingdom: Issues for the United States

National Research Council Canada - National Science Library

Archick, Kristin

2007-01-01

...; and more recently, from the UK's strong support in countering terrorism and confronting Iraq. The United States and Britain also share a mutually beneficial trade and economic relationship, and are each other's biggest foreign direct investors...

Radiation therapy facilities in the United States

International Nuclear Information System (INIS)

Ballas, Leslie K.; Elkin, Elena B.; Schrag, Deborah; Minsky, Bruce D.; Bach, Peter B.

2006-01-01

Purpose: About half of all cancer patients in the United States receive radiation therapy as a part of their cancer treatment. Little is known, however, about the facilities that currently deliver external beam radiation. Our goal was to construct a comprehensive database of all radiation therapy facilities in the United States that can be used for future health services research in radiation oncology. Methods and Materials: From each state's health department we obtained a list of all facilities that have a linear accelerator or provide radiation therapy. We merged these state lists with information from the American Hospital Association (AHA), as well as 2 organizations that audit the accuracy of radiation machines: the Radiologic Physics Center (RPC) and Radiation Dosimetry Services (RDS). The comprehensive database included all unique facilities listed in 1 or more of the 4 sources. Results: We identified 2,246 radiation therapy facilities operating in the United States as of 2004-2005. Of these, 448 (20%) facilities were identified through state health department records alone and were not listed in any other data source. Conclusions: Determining the location of the 2,246 radiation facilities in the United States is a first step in providing important information to radiation oncologists and policymakers concerned with access to radiation therapy services, the distribution of health care resources, and the quality of cancer care

75 FR 13345 - Pricing for Certain 2010 United States Mint Products

Science.gov (United States)

2010-03-19

... DEPARTMENT OF THE TREASURY United States Mint Pricing for Certain 2010 United States Mint Products AGENCY: United States Mint, Department of the Treasury. ACTION: Notice. SUMMARY: The United States Mint is announcing the price of the 2010 United States Mint Presidential $1 Coin and First Spouse Medal...

Intergenerational educational mobility in Denmark and the United States

DEFF Research Database (Denmark)

Andrade, Stefan Bastholm; Thomsen, Jens-Peter

2018-01-01

An overall finding in comparative mobility studies is that intergenerational mobility is greater in Scandinavia than in liberal welfare-state countries like the United States and United Kingdom. However, in a recent study, Landersø and Heckman (L & H) (2017) argue that intergenerational educational...... mobility in Denmark and the United States is remarkably similar. L & H’s findings run contrary to widespread beliefs and have been echoed in academia and mass media on both sides of the Atlantic Ocean. In this article, we reanalyze educational mobility in Denmark and the United States using the same data...... sources as L & H. We apply several different methodological approaches from economics and sociology, and we consistently find that educational mobility is higher in Denmark than in the United States....

Toll Facilities in the United States

Data.gov (United States)

Department of Transportation — Biennial report containing selected information on toll facilities in the United States that has been provided to FHWA by the States and/or various toll authorities...

State nuclear initiatives in the United States

International Nuclear Information System (INIS)

Strauss, P.L.; Stoiber, C.R.

1977-01-01

The paper deals with State nuclear initiatives regarding the role of nuclear power in the energy future of the United States. The question of whether and under what circumstances nuclear facilities should be used to generate electricity was put to the popular vote in several States in 1976. Some general principles of Federal-State relations are discussed with specific reference to nuclear regulations. The initiative mechanism itself is described as well as its legal form and background. The parallel developments in the State and Federal legislative consideration of nuclear issues is reviewed and the suggested reasons for the defeat of the proposals in the seven States concerned are discussed. Finally, the author draws some conclusions on the effects of the 1976 initiatives on future decision-making in the US on energy policy in general and nuclear power in particular. (NEA) [fr

Phosphoric acid based pretreatment of switchgrass and fermentation of entire slurry to ethanol using a simplified process.

Science.gov (United States)

Wu, Wei; Rondon, Vanessa; Weeks, Kalvin; Pullammanappallil, Pratap; Ingram, Lonnie O; Shanmugam, K T

2018-03-01

Switchgrass (Alamo) was pretreated with phosphoric acid (0.75 and 1%, w/w) at three temperatures (160, 175 and 190 °C) and time (5, 7.5 and 10 min) using a steam gun. The slurry after pretreatment was liquefied by enzymes and the released sugars were fermented in a simultaneous saccharification and co-fermentation process to ethanol using ethanologenic Escherichia coli strain SL100. Among the three variables in pretreatment, temperature and time were critical in supporting ethanol titer and yield. Enzyme hydrolysis significantly increased the concentration of furans in slurries, apparently due to release of furans bound to the solids. The highest ethanol titer of 21.2 ± 0.3 g/L ethanol obtained at the pretreatment condition of 190-1-7.5 (temperature-acid concentration-time) and 10% solids loading accounted for 190 ± 2.9 g ethanol/kg of raw switch grass. This converts to 61.7 gallons of ethanol per ton of dry switchgrass, a value that is comparable to other published pretreatment conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

27 CFR 479.89 - Transfers to the United States.

Science.gov (United States)

2010-04-01

... Transfers to the United States. A firearm may be transferred to the United States or any department... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Transfers to the United States. 479.89 Section 479.89 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO...

Nitrous oxide emission and soil carbon sequestration from herbaceous perennial biofuel feedstocks

Science.gov (United States)

Greenhouse gas (GHG) mitigation and renewable, domestic fuels are needed in the United States. Switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman) are potential bioenergy feedstocks that may meet this need. However, managing perennial grasses for feedstock requires nitro...

32 CFR 516.54 - Witnesses for the United States.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Witnesses for the United States. 516.54 Section..., Travel, and Expenses of Witnesses § 516.54 Witnesses for the United States. (a) Status of witness. A military member authorized to appear as a witness for the United States, including those authorized to...

32 CFR 150.21 - Appeals by the United States.

Science.gov (United States)

2010-07-01

... 32 National Defense 1 2010-07-01 2010-07-01 false Appeals by the United States. 150.21 Section 150... the United States. (a) Restricted filing. Only a representative of the government designated by the Judge Advocate General of the respective service may file an appeal by the United States under Article...

Dynamic changes in transcriptome and cell wall composition underlying brassinosteroid-mediated lignification of switchgrass suspension cells.

Science.gov (United States)

Rao, Xiaolan; Shen, Hui; Pattathil, Sivakumar; Hahn, Michael G; Gelineo-Albersheim, Ivana; Mohnen, Debra; Pu, Yunqiao; Ragauskas, Arthur J; Chen, Xin; Chen, Fang; Dixon, Richard A

2017-01-01

Plant cell walls contribute the majority of plant biomass that can be used to produce transportation fuels. However, the complexity and variability in composition and structure of cell walls, particularly the presence of lignin, negatively impacts their deconstruction for bioenergy. Metabolic and genetic changes associated with secondary wall development in the biofuel crop switchgrass ( Panicum virgatum ) have yet to be reported. Our previous studies have established a cell suspension system for switchgrass, in which cell wall lignification can be induced by application of brassinolide (BL). We have now collected cell wall composition and microarray-based transcriptome profiles for BL-induced and non-induced suspension cultures to provide an overview of the dynamic changes in transcriptional reprogramming during BL-induced cell wall modification. From this analysis, we have identified changes in candidate genes involved in cell wall precursor synthesis, cellulose, hemicellulose, and pectin formation and ester-linkage generation. We have also identified a large number of transcription factors with expression correlated with lignin biosynthesis genes, among which are candidates for control of syringyl (S) lignin accumulation. Together, this work provides an overview of the dynamic compositional changes during brassinosteroid-induced cell wall remodeling, and identifies candidate genes for future plant genetic engineering to overcome cell wall recalcitrance.

United States housing, first quarter 2013

Science.gov (United States)

Delton Alderman

2014-01-01

Provides current and historical information on housing market in the United States. Information includes trends for housing permits and starts, housing under construction, and housing completions for single and multifamily units, and sales and construction. This report will be updated regularly.

Induced Phytoextraction of Lead Through Chemical Manipulation of Switchgrass and Corn; Role of Iron Supplement.

Science.gov (United States)

Johnson, Deayne M; Deocampo, Daniel M; El-Mayas, Hanan; Greipsson, Sigurdur

2015-01-01

The effects of combined chemical application of benomyl, ethylenedianinetetraacetate (EDTA), and iron (Fe) (foliar and root) on lead (Pb) phytoextraction by switchgrass (Panicum virgatum) and corn (Zea mays) was examined. Switchgrass was grown in Pb-contaminated urban topsoil with the following treatments: (C) Control, (B) benomyl, (E) EDTA, (F) foliar-Fe, (BE) benomyl + EDTA, (BF) benomyl + foliar-Fe, (FE) foliar-Fe + EDTA, (BFE) benomyl + foliar-Fe + EDTA. Corn was grown in sand-culture supplemented with Pb (500 mg kg(-1)) with the following treatments: (C) control, (B) benomyl, (E) EDTA, (F) root-Fe, (BE) benomyl + EDTA, (BF) benomyl + root-Fe, (FE) root-iron + EDTA, and, (BFE) benomyl + root-Fe + EDTA. All treatments were replicated three times and pots were arranged in a completely randomized design. Plants were analyzed for element concentration (Fe, Zn, P, and Pb) using either inductively coupled plasma (argon) atomic emission spectroscopy (ICP-AES) or graphite furnace atomic absorption spectrometer. Iron supplementation (foliar and root) affected Pb-translocation in plants. Foliar-Fe treatment increased translocation ratio of Pb (TF-Pb) significantly compared to other treatments with the exception of plants treated with benomyl and BF. Root-Fe treatment in combination with EDTA (FE) increased TF-Pb significantly compared to other treatments. Phytoextraction was improved by the combined chemical application; plants treated with BFE treatment increased Pb-total-phytoextraction by 424% compared to Control plants.

Substrate-Specific Development of Thermophilic Bacterial Consortia by Using Chemically Pretreated Switchgrass.

Science.gov (United States)

Eichorst, Stephanie A; Joshua, Chijioke; Sathitsuksanoh, Noppadon; Singh, Seema; Simmons, Blake A; Singer, Steven W

2014-12-01

Microbial communities that deconstruct plant biomass have broad relevance in biofuel production and global carbon cycling. Biomass pretreatments reduce plant biomass recalcitrance for increased efficiency of enzymatic hydrolysis. We exploited these chemical pretreatments to study how thermophilic bacterial consortia adapt to deconstruct switchgrass (SG) biomass of various compositions. Microbial communities were adapted to untreated, ammonium fiber expansion (AFEX)-pretreated, and ionic-liquid (IL)-pretreated SG under aerobic, thermophilic conditions using green waste compost as the inoculum to study biomass deconstruction by microbial consortia. After microbial cultivation, gravimetric analysis of the residual biomass demonstrated that both AFEX and IL pretreatment enhanced the deconstruction of the SG biomass approximately 2-fold. Two-dimensional nuclear magnetic resonance (2D-NMR) experiments and acetyl bromide-reactive-lignin analysis indicated that polysaccharide hydrolysis was the dominant process occurring during microbial biomass deconstruction, and lignin remaining in the residual biomass was largely unmodified. Small-subunit (SSU) rRNA gene amplicon libraries revealed that although the dominant taxa across these chemical pretreatments were consistently represented by members of the Firmicutes, the Bacteroidetes, and Deinococcus-Thermus, the abundance of selected operational taxonomic units (OTUs) varied, suggesting adaptations to the different substrates. Combining the observations of differences in the community structure and the chemical and physical structure of the biomass, we hypothesize specific roles for individual community members in biomass deconstruction. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Arsenic in Ground Water of the United States

Science.gov (United States)

... Team More Information Arsenic in groundwater of the United States Arsenic in groundwater is largely the result of ... Gronberg (2011) for updated arsenic map. Featured publications United States Effects of human-induced alteration of groundwater flow ...

Enrichment situation outside the United States

International Nuclear Information System (INIS)

Anon.

1979-01-01

Different enrichment technologies are briefly characterized which include gaseous diffusion, which is presently the production mainstay of the United States and France; the gaseous centrifuge which is the production plant for Urenco and the technology for future United States enrichment expansion; the aero-dynamic processes which include the jet nozzle (also known as the Becker process) and the fixed-wall centrifuge (also known as the Helikon process); chemical processes; laser isotope separation processes (also referred to in the literature as LIS); and plasma technology

Leading Causes of Death in Females United States

Science.gov (United States)

... and Health Issues at Work Health Equity Leading Causes of Death in Females, United States Recommend on Facebook Tweet ... to current and previous listings for the leading causes of death in females in the United States. Please note ...

33 CFR 2.38 - Waters subject to the jurisdiction of the United States; waters over which the United States has...

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Waters subject to the jurisdiction of the United States; waters over which the United States has jurisdiction. 2.38 Section 2.38 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL JURISDICTION...

Unites States and the oil of the Middle-East

International Nuclear Information System (INIS)

Noel, P.

2005-08-01

The author discusses different aspects of the United States intervention and behavior in the Middle-East petroleum management. The Iraq and Iran potentials are largely under used. The Saudi Arabia defines its own oil policy, but benefits of the Unites States military help. The United States intervention is in the domain of the security of flux on the world market. (A.L.B.)

Measurement of steroidal saponins in Panicum and Brachiaria grasses in the USA and Brazil

Science.gov (United States)

Several grasses in the Panicum genus have been reported to cause hepatogenous photosensitization in animals throughout the world. In the United States, switchgrass (Panicum virgatum L.) has been reported to cause hepatogenous photosensitization in lambs and horses. In Brazil, cultivars of Panicum ...

Biomass Feedstocks | Bioenergy | NREL

Science.gov (United States)

Feedstocks Biomass Feedstocks Our mission is to enable the coordinated development of biomass generic biomass thermochemical conversion process (over a screened-back map of the United States) showing U.S. Biomass Resources, represented by photos of timber, corn stover, switchgrass, and poplar. All

Food irradiation in the United States

International Nuclear Information System (INIS)

Pauli, G.H.

1991-01-01

Since 1963, some irradiated foods have been permitted for sale in the United States. Yet, at this time, commercial application has been limited to irradiation of a relatively small fraction of the spices and seasonings used as ingredients in other foods. The current situation regarding irradiated foods in the United States and how it developed is discussed. The author writes from experience gained as a Government regulator concerned primarily with ensuring safety of food and therefore this is stressed together with the crucial role played by consumers and industry. (author)

Large-scale bioenergy production from soybeans and switchgrass in Argentina: Part A: Potential and economic feasibility for national and international markets

NARCIS (Netherlands)

van Dam, J.; Faaij, A.P.C.; Hilbert, J.; Petruzzi, H.; Turkenburg, W.C.

2009-01-01

This study focuses on the economic feasibility for large-scale biomass production from soybeans or switchgrass from a region in Argentina. This is determined, firstly, by estimating whether the potential supply of biomass, when food and feed demand are met, is sufficient under different scenarios to

The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States

Science.gov (United States)

Horton, John D.; San Juan, Carma A.; Stoeser, Douglas B.

2017-06-30

The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States (https://doi. org/10.5066/F7WH2N65) represents a seamless, spatial database of 48 State geologic maps that range from 1:50,000 to 1:1,000,000 scale. A national digital geologic map database is essential in interpreting other datasets that support numerous types of national-scale studies and assessments, such as those that provide geochemistry, remote sensing, or geophysical data. The SGMC is a compilation of the individual U.S. Geological Survey releases of the Preliminary Integrated Geologic Map Databases for the United States. The SGMC geodatabase also contains updated data for seven States and seven entirely new State geologic maps that have been added since the preliminary databases were published. Numerous errors have been corrected and enhancements added to the preliminary datasets using thorough quality assurance/quality control procedures. The SGMC is not a truly integrated geologic map database because geologic units have not been reconciled across State boundaries. However, the geologic data contained in each State geologic map have been standardized to allow spatial analyses of lithology, age, and stratigraphy at a national scale.

Complete genome sequence of switchgrass mosaic virus, a member of a proposed new species in the genus Marafivirus.

Science.gov (United States)

Agindotan, Bright O; Gray, Michael E; Hammond, Rosemarie W; Bradley, Carl A

2012-09-01

The complete genome sequence of a virus recently detected in switchgrass (Panicum virgatum) was determined and found to be closely related to that of maize rayado fino virus (MRFV), genus Marafivirus, family Tymoviridae. The genomic RNA is 6408 nucleotides long. It contains three predicted open reading frames (ORFs 1-3), encoding proteins of 227 kDa, 43.9 kDa, and 31.5 kDa, compared to two ORFs (1 and 2) for MRFV. The complete genome shares 76 % sequence identity with MRFV. The nucleotide sequence of ORF2 of this virus and the amino acid sequence of its encoded protein are 49 % and 77 % identical, respectively, to those of MRFV. The virus-encoded polyprotein and capsid protein aa sequences are 83 % and 74-80 % identical, respectively, to those of MRFV. Although closely related to MRFV, the amino acid sequence of its capsid protein (CP) forms a clade that is separate from that of MRFV. Based on the International Committee on Taxonomy of Viruses (ICTV) sequence-related criteria for delineation of species within the genus Marafivirus, the virus qualifies as a member of a new species, and the name Switchgrass mosaic virus (SwMV) is proposed.

Exporting Rambutan to United States: One Reality?

International Nuclear Information System (INIS)

Ahmad Zainuri Mohd Dzomir; Zainon Othman; Mohd Sidek Othman

2011-01-01

Rambutan is a one of commodity that are passed by United States of America authority to be market in that states. The main condition for the approval is the exporter must use irradiation technology as quarantine treatment to monitor the insects in there. United States of America's Agriculture Department (USDA-APHIS) has make early survey to the facilities involved in exporting process chain to overview Malaysia preparedness for this purpose. This paper work will discussed the possibility of this exporting implemented based on conditions rule by the USDA. (author)

Wheat rusts in the United States in 2016

Science.gov (United States)

In 2016, wheat stripe rust caused by Puccinia striiformis f. sp. graminis was widespread throughout the United States. Cool temperatures and abundant rainfall in the southern Great Plains allowed stripe rust to become widely established and spread throughout the Great Plains and eastern United State...

United States National Seismographic Network

International Nuclear Information System (INIS)

Buland, R.

1993-09-01

The concept of a United States National Seismograph Network (USNSN) dates back nearly 30 years. The idea was revived several times over the decades. but never funded. For, example, a national network was proposed and discussed at great length in the so called Bolt Report (U. S. Earthquake Observatories: Recommendations for a New National Network, National Academy Press, Washington, D.C., 1980, 122 pp). From the beginning, a national network was viewed as augmenting and complementing the relatively dense, predominantly short-period vertical coverage of selected areas provided by the Regional Seismograph Networks (RSN's) with a sparse, well-distributed network of three-component, observatory quality, permanent stations. The opportunity finally to begin developing a national network arose in 1986 with discussions between the US Geological Survey (USGS) and the Nuclear Regulatory Commission (NRC). Under the agreement signed in 1987, the NRC has provided $5 M in new funding for capital equipment (over the period 1987-1992) and the USGS has provided personnel and facilities to develop. deploy, and operate the network. Because the NRC funding was earmarked for the eastern United States, new USNSN station deployments are mostly east of 105 degree W longitude while the network in the western United States is mostly made up of cooperating stations (stations meeting USNSN design goals, but deployed and operated by other institutions which provide a logical extension to the USNSN)

37 CFR 1.413 - The United States International Searching Authority.

Science.gov (United States)

2010-07-01

... Processing Provisions General Information § 1.413 The United States International Searching Authority. (a... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false The United States International Searching Authority. 1.413 Section 1.413 Patents, Trademarks, and Copyrights UNITED STATES PATENT...

United States Attorney Prosecutions

Science.gov (United States)

1993-10-01

property of CocaCola Bottling Company, Fayetteville, North Carolina, of a value in excess of $100.00, in violation of Title 18 United States Code, Section...another, to-wit: a Cocacola soft drink machine, the amount of damage to said personal property being more than $200.00, in violation of North Carolina

77 FR 48542 - United States

Science.gov (United States)

2012-08-14

... litigation.'' United States v. Armour and Co., 402 U.S. 673, 681 (1971). Section 5 of the Clayton Act... relief in consent judgment that contained recitals in which defendants asserted their innocence); Armour...

United States Strategy for Mexico

National Research Council Canada - National Science Library

Centner, Robert C

2005-01-01

The security and stability of Mexico is of national interest to the United States, and a strong, effective alliance between the two countries is pivotal to our national defense strategy and economic prosperity...

NCHS - Injury Mortality: United States

Data.gov (United States)

U.S. Department of Health & Human Services — This dataset describes injury mortality in the United States beginning in 1999. Two concepts are included in the circumstances of an injury death: intent of injury...

Both Europe's and the United States' electrification

International Nuclear Information System (INIS)

Matly, M.

2006-01-01

While the United States quickly had the largest electrical indus in the world, electrification in rural areas ended about thirty years after most European countries. Public intervention is a deciding factor in completing electrification, and the late involvement by the American authorities explains the gap. However it would be wrong to oppose in Europe and in the United States a motivated public sector and little involved private companies. In both continents indeed, major private and public urban distributors were almost not involved in rural electrification processes, where local players prevailed: local communities around Europe, small and medium size business in some European countries such as France, co-operative companies in the United States. Additionally, there is an essential difference between electrification in Europe and in the United States. The former does not provide much more than lighting and its success leaves few traces in popular memories; the latter includes many facilities and services, changes the lives of rural populations and is celebrated a such. Whereas the colonial venture keep European economies away from their domestic markets, while in the United States the urban market growth contents large companies, the American co-operative movement is right to believe in the existence of a large electrical equipment market among farmers then considered poor and behind. It even uses the market to complete a more profitable and less costly electrification. Electricity stories that offer food for the thoughts of Third World decision makers and power companies, when they entrust most rural electrification to their large urban companies and deny the existence of a real equipment market in their own rural world. (author)

Asian Immigration: The View from the United States.

Science.gov (United States)

Gardner, Robert W.

1992-01-01

Examines contemporary Asian immigration to the United States from a U.S. perspective. Analyzes immigration policies and data on recent immigration from Asia. Discusses impacts concerning the United States and the immigrants themselves and speculates on future immigration. The composition of Asian immigration might change, and the number might…

26 CFR 1.956-2 - Definition of United States property.

Science.gov (United States)

2010-04-01

..., which is— (i) Tangible property (real or personal) located in the United States; (ii) Stock of a... year ending June 30, 1964, R Corporation's increase in earnings invested in United States property for... United States property during its taxable year 1965, S Corporation's increase in earnings invested in...

Licensed pertussis vaccines in the United States: History and current state

OpenAIRE

Klein, Nicola P

2014-01-01

The United States switched from whole cell to acellular pertussis vaccines in the 1990s following global concerns with the safety of the whole cell vaccines. Despite high levels of acellular pertussis vaccine coverage, the United States and other countries are experiencing large pertussis outbreaks. The aim of this article is to describe the historical context which led to acellular pertussis vaccine development, focusing on vaccines currently licensed in the US, and to review evidence that w...

Nations United: The United Nations, the United States, and the Global Campaign Against Terrorism. A Curriculum Unit & Video for Secondary Schools.

Science.gov (United States)

Houlihan, Christina; McLeod, Shannon

This curriculum unit and 1-hour videotape are designed to help students understand the purpose and functions of the United Nations (UN) and explore the relationship between the United Nations and the United States. The UN's role in the global counterterrorism campaign serves as a case study for the unit. The students are asked to develop a basic…

Estimated United States Transportation Energy Use 2005

Energy Technology Data Exchange (ETDEWEB)

Smith, C A; Simon, A J; Belles, R D

2011-11-09

A flow chart depicting energy flow in the transportation sector of the United States economy in 2005 has been constructed from publicly available data and estimates of national energy use patterns. Approximately 31,000 trillion British Thermal Units (trBTUs) of energy were used throughout the United States in transportation activities. Vehicles used in these activities include automobiles, motorcycles, trucks, buses, airplanes, rail, and ships. The transportation sector is powered primarily by petroleum-derived fuels (gasoline, diesel and jet fuel). Biomass-derived fuels, electricity and natural gas-derived fuels are also used. The flow patterns represent a comprehensive systems view of energy used within the transportation sector.

United States of America National Report

International Nuclear Information System (INIS)

1992-01-01

The United States has produced this report as part of the preparations for the United Nations Conference on Environment and Development (UNCED) to be held in Brazil in June 1992. It summarizes this nation's efforts to protect and enhance the quality of the human environment in concert with its efforts to provide economic well-being during the two decades since the United Nations Conference on the Human Environment was held in Stockholm. The information presented in this report is primarily and deliberately retrospective. It is an attempt to portray the many human, economic and natural resources of the United States, to describe resource use and the principal national laws and programs established to protect these resources, and to analyze key issues on the agenda of UNCED. This analysis is presented in terms of past and present conditions and trends, measures of progress made in responding to the key issues, and a summary of government activities, underway or pending, to address ongoing or newly emerging national environmental and resource management problems

African Journals Online: United States Minor Outlying Islands

African Journals Online (AJOL)

African Journals Online: United States Minor Outlying Islands. Home > African Journals Online: United States Minor Outlying Islands. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles ...

Refugee Status Required for Resettlement in the United States

Science.gov (United States)

2017-06-09

STATES REFUGEE ADMISSIONS PROGRAM FLOWCHART ...the American public’s concerns. 50 APPENDIX A UNITED STATES REFUGEE ADMISSIONS PROGRAM FLOWCHART Source: US Citizenship and Immigration...TITLE AND SUBTITLE Refugee Status Required for Resettlement in the United States 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

Latin America and the United States: What Do United States History Textbooks Tell Us?

Science.gov (United States)

Fleming, Dan B.

1982-01-01

Evaluates how U.S.-Latin American relations are presented in high school U.S. history textbooks. An examination of 10 textbooks published between 1977-81 revealed inadequate coverage of Latin American cultural diversity and United States foreign policy from the Latin American perspective. (AM)

Preparation of School Psychologists in the United States

Science.gov (United States)

Joyce-Beaulieu, Diana; Rossen, Eric

2014-01-01

School psychology in the United States continues to evolve in response to shifts in the country's demographic characteristics, an increasing focus on the importance of child mental health, together with health and education reforms. The landscape of school psychological services in the United States also is shaped through the changing roles and…

Lignocellulose fermentation and residual solids characterization for senescent switchgrass fermentation by Clostridium thermocellum in the presence and absence of continuous in situ ball-milling

Energy Technology Data Exchange (ETDEWEB)

Balch, Michael L.; Holwerda, Evert K.; Davis, Mark F.; Sykes, Robert W.; Happs, Renee M.; Kumar, Rajeev; Wyman, Charles E.; Lynd, Lee R.

2017-04-12

Milling during lignocellulosic fermentation, henceforth referred to as cotreatment, is investigated as an alternative to thermochemical pretreatment as a means of enhancing biological solubilization of lignocellulose. We investigate the impact of milling on soluble substrate fermentation by Clostridium thermocellum with comparison to yeast, document solubilization for fermentation of senescent switchgrass with and without ball milling, and characterize residual solids. Soluble substrate fermentation by C. thermocellum proceeded readily in the presence of continuous ball milling but was completely arrested for yeast. Total fractional carbohydrate solubilization achieved after fermentation of senescent switchgrass by C. thermocellum for 5 days was 0.45 without cotreatment or pretreatment, 0.81 with hydrothermal pretreatment (200 degrees C, 15 minutes, severity 4.2), and 0.88 with cotreatment. Acetate and ethanol were the main fermentation products, and were produced at similar ratios with and without cotreatment. Analysis of solid residues was undertaken using molecular beam mass spectrometry (PyMBMS) and solid-state nuclear magnetic resonance spectroscopy (NMR) in order to provide insight into changes in plant cell walls during processing via various modes. The structure of lignin present in residual solids remaining after fermentation with cotreatment appeared to change little, with substantially greater changes observed for hydrothermal pretreatment - particularly with respect to formation of C-C bonds. The observation of high solubilization with little apparent modification of the residue is consistent with cotreatment enhancing solubilization primarily by increasing the access of saccharolytic enzymes to the feedstock, and C. thermocellum being able to attack all the major linkages in cellulosic biomass provided that these linkages are accessible.

United States position on severe accidents

International Nuclear Information System (INIS)

Ross, D.F.

1988-01-01

The United States policy on severe accidents was published in 1985 for both new plant applications and for existing plants. Implementation of this policy is in progress. This policy, aided by a related safety goal policy and by analysis capabilities emerging from improved understanding of accident phenomenology, is viewed as a logical development from the pioneering work in the WASH-1400 Reactor Safety Study published by the United States Nuclear Regulatory Commission (NRC) in 1975. This work provided an estimate of the probability and consequences of severe accidents which, prior to that time, had been mostly evaluated by somewhat arbitrary assumptions dating back 30 years. The early history of severe accident evaluation is briefly summarized for the period 1957-1979. Then, the galvanizing action of Three Mile Island Unit 2 (TMI-2) on severe accident analysis, experimentation and regulation is reviewed. Expressions of US policy in the form of rulemaking, severe accident policy, safety research, safety goal policy and court decisions (on adequacy of safety) are discussed. Finally, the NRC policy as of March 1988 is stated, along with a prospective look at the next few years. (author). 19 refs

Understanding human trafficking in the United States.

Science.gov (United States)

Logan, T K; Walker, Robert; Hunt, Gretchen

2009-01-01

The topic of modern-day slavery or human trafficking has received increased media and national attention. However, to date there has been limited research on the nature and scope of human trafficking in the United States. This article describes and synthesizes nine reports that assess the U.S. service organizations' legal representative knowledge of, and experience with, human trafficking cases, as well as information from actual cases and media reports. This article has five main goals: (a) to define what human trafficking is, and is not; (b) to describe factors identified as contributing to vulnerability to being trafficked and keeping a person entrapped in the situation; (c) to examine how the crime of human trafficking differs from other kinds of crimes in the United States; (d) to explore how human trafficking victims are identified; and, (e) to provide recommendations to better address human trafficking in the United States.

42 CFR 410.175 - Alien absent from the United States.

Science.gov (United States)

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Alien absent from the United States. 410.175... Alien absent from the United States. (a) Medicare does not pay Part B benefits for services furnished to... during the first full calendar month the alien is back in the United States. [53 FR 6634, Mar. 2, 1988] ...

Inventory of power plants in the United States. [By state within standard Federal Regions, using county codes

Energy Technology Data Exchange (ETDEWEB)

None

1977-12-01

The purpose of this inventory of power plants is to provide a ready reference for planners whose focus is on the state, standard Federal region, and/or national level. Thus the inventory is compiled alphabetically by state within standard Federal regions. The units are listed alphabetically within electric utility systems which in turn are listed alphabetically within states. The locations are identified to county level according to the Federal Information Processing Standards Publication Counties and County Equivalents of the States of the United States. Data compiled include existing and projected electrical generation units, jointly owned units, and projected construction units.

Norovirus in the United States

Centers for Disease Control (CDC) Podcasts

2013-09-09

Dr. Aron Hall, a CDC epidemiologist specializing in norovirus, discusses the impact of norovirus in the United States.  Created: 9/9/2013 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 9/17/2013.

Fragmentation of Continental United States Forests

Science.gov (United States)

Kurt H. Riitters; James D. Wickham; Robert V. O' Neill; K. Bruce Jones; Elizabeth R. Smith; John W. Coulston; Timothy G. Wade; Jonathan H. Smith

2002-01-01

We report a multiple-scale analysis of forest fragmentation based on 30-m (0.09 ha pixel-1) land- cover maps for the conterminous United States. Each 0.09-ha unit of forest was classified according to fragmentation indexes measured within the surrounding landscape, for five landscape sizes including 2.25, 7.29, 65.61, 590.49, and 5314.41 ha....

Microplate-Based Evaluation of the Sugar Yield from Giant Reed, Giant Miscanthus and Switchgrass after Mild Chemical Pre-Treatments and Hydrolysis with Tailored Trichoderma Enzymatic Blends.

Science.gov (United States)

Cianchetta, Stefano; Bregoli, Luca; Galletti, Stefania

2017-11-01

Giant reed, miscanthus, and switchgrass are considered prominent lignocellulosic feedstocks to obtain fermentable sugars for biofuel production. The bioconversion into sugars requires a delignifying pre-treatment step followed by hydrolysis with cellulase and other accessory enzymes like xylanase, especially in the case of alkali pre-treatments, which retain the hemicellulose fraction. Blends richer in accessory enzymes than commercial mix can be obtained growing fungi on feedstock-based substrates, thus ten selected Trichoderma isolates, including the hypercellulolytic strain Trichoderma reesei Rut-C30, were grown on giant reed, miscanthus, or switchgrass-based substrates. The produced enzymes were used to saccharify the corresponding feedstocks, compared to a commercial enzymatic mix (6 FPU/g). Feedstocks were acid (H 2 SO 4 0.2-2%, w/v) or alkali (NaOH 0.02-0.2%, w/v) pre-treated. A microplate-based approach was chosen for most of the experimental steps due to the large number of samples. The highest bioconversion was generally obtained with Trichoderma harzianum Or4/99 enzymes (78, 89, and 94% final sugar yields at 48 h for giant reed, miscanthus, and switchgrass, respectively), with significant increases compared to the commercial mix, especially with alkaline pre-treatments. The differences in bioconversion yields were only partially caused by xylanases (maximum R 2  = 0.5), indicating a role for other accessory enzymes.

Trial by jury in the United States

Directory of Open Access Journals (Sweden)

Lochhead Robert

2015-10-01

Full Text Available Th e Republic of Moldova is considering the adoption of trial by jury in select criminal cases. Th e following article is intended to contribute to the discussion of that proposal. Th e article will briefl y describe the history of juries under the English common law and as adopted by the United States. It will then outline some of the basic procedures in trials by jury as currently practiced in the United States federal court system.

CEDAW in the Eyes of the United States

Directory of Open Access Journals (Sweden)

Al Shraideh Saleh

2017-12-01

Full Text Available Despite the large number of reservations registered by Member countries, making it one of the, if not the, most heavily reserved human rights treaties; the Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW has managed to achieve a very high rate of states’ membership [1]. Currently, 187 countries out of the 193 United Nations Members are parties to CEDAW [2]. What is strange to digest, however, is the fact that the United States is one of the seven countries that are yet to ratify the Convention [3]. This article provides an insight into the position of the United States from the ratification of CEDAW. It examines the merits of arguments made for and against the ratification and their rationale to provide a better understanding that explains what is considered by many as a buzzling stand of the United States from the Convention.

Global context for the United States Forest Sector in 2030

Science.gov (United States)

James Turner; Joseph Buongiorno; Shushuai Zhu; Jeffrey P. Prestemon

2005-01-01

The purpose of this study was to identify markets for, and competitors to, the United States forest industries in the next 30 years. The Global Forest Products Model was used to make predictions of international demand, supply, trade, and prices, conditional on the last RPA Timber Assessment projections for the United States. It was found that the United States, Japan...

A functional intranet for the United States Coast Guard Unit

OpenAIRE

Hannah, Robert Todd.

1998-01-01

Approved for public release; distribution in unlimited. This thesis describes the complete development process of a friendly functional Intranet for an operational United States Coast Guard (USCG) electronic Support Unit (ESU) in Alameda, California. The final product is suitable for immediate use. It may also be used as a prototype for future Intranet development efforts. The methodology used to develop a finished, working product provides the core subject matter for this thesis. The disc...

Residency training in the United States: What foreign medical ...

African Journals Online (AJOL)

FMGs) planning to pursue post-graduate residency training in the United States of America (USA). While the number of residency training positions is shrinking, and the number of United States graduates has steadily declined over the past ...

The state of amphibians in the United States

Science.gov (United States)

Muths, E.; Adams, M.J.; Grant, E.H.C.; Miller, D.; Corn, P.S.; Ball, L.C.

2012-01-01

More than 25 years ago, scientists began to identify unexplained declines in amphibian populations around the world. Much has been learned since then, but amphibian declines have not abated and the interactions among the various threats to amphibians are not clear. Amphibian decline is a problem of local, national, and international scope that can affect ecosystem function, biodiversity, and commerce. This fact sheet provides a snapshot of the state of the amphibians and introduces examples to illustrate the range of issues in the United States.

Inventory of power plants in the United States, 1993

International Nuclear Information System (INIS)

1994-12-01

The Inventory of Power Plants in the United States is prepared annually by the Survey Management Division, Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), U.S. Department of Energy (DOE). The purpose of this publication is to provide year-end statistics about electric generating units operated by electric utilities in the United States (the 50 States and the District of Columbia). The publication also provides a 10-year outlook of future generating unit additions. Data summarized in this report are useful to a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. Data presented in this report were assembled and published by the EIA to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended

Inventory of power plants in the United States, 1993

Energy Technology Data Exchange (ETDEWEB)

1994-12-01

The Inventory of Power Plants in the United States is prepared annually by the Survey Management Division, Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), U.S. Department of Energy (DOE). The purpose of this publication is to provide year-end statistics about electric generating units operated by electric utilities in the United States (the 50 States and the District of Columbia). The publication also provides a 10-year outlook of future generating unit additions. Data summarized in this report are useful to a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. Data presented in this report were assembled and published by the EIA to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended.

Use of Internet Search Data to Monitor Rotavirus Vaccine Impact in the United States, United Kingdom, and Mexico.

Science.gov (United States)

Shah, Minesh P; Lopman, Benjamin A; Tate, Jacqueline E; Harris, John; Esparza-Aguilar, Marcelino; Sanchez-Uribe, Edgar; Richardson, Vesta; Steiner, Claudia A; Parashar, Umesh D

2018-02-19

Previous studies have found a strong correlation between internet search and public health surveillance data. Less is known about how search data respond to public health interventions, such as vaccination, and the consistency of responses in different countries. In this study, we aimed to study the correlation between internet searches for "rotavirus" and rotavirus disease activity in the United States, United Kingdom, and Mexico before and after introduction of rotavirus vaccine. We compared time series of internet searches for "rotavirus" from Google Trends with rotavirus laboratory reports from the United States and United Kingdom and with hospitalizations for acute gastroenteritis in the United States and Mexico. Using time and location parameters, Google quantifies an internet query share (IQS) to measure the relative search volume for specific terms. We analyzed the correlation between IQS and laboratory and hospitalization data before and after national vaccine introductions. There was a strong positive correlation between the rotavirus IQS and laboratory reports in the United States (R2 = 0.79) and United Kingdom (R2 = 0.60) and between the rotavirus IQS and acute gastroenteritis hospitalizations in the United States (R2 = 0.87) and Mexico (R2 = 0.69) (P United States and by 70% (95% CI, 55%-86%) in Mexico. In the United Kingdom, there was a loss of seasonal variation after vaccine introduction. Rotavirus internet search data trends mirrored national rotavirus laboratory trends in the United States and United Kingdom and gastroenteritis-hospitalization data in the United States and Mexico; lower correlations were found after rotavirus vaccine introduction. Published by Oxford University Press on behalf of The Journal of the Pediatric Infectious Diseases Society 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Licensed pertussis vaccines in the United States. History and current state.

Science.gov (United States)

Klein, Nicola P

2014-01-01

The United States switched from whole cell to acellular pertussis vaccines in the 1990s following global concerns with the safety of the whole cell vaccines. Despite high levels of acellular pertussis vaccine coverage, the United States and other countries are experiencing large pertussis outbreaks. The aim of this article is to describe the historical context which led to acellular pertussis vaccine development, focusing on vaccines currently licensed in the US, and to review evidence that waning protection following licensed acellular pertussis vaccines have been significant factors in the widespread reappearance of pertussis.

The United States initiative for international radioactive source management (ISRM)

International Nuclear Information System (INIS)

Naraine, N.; Karhnak, J.

1999-01-01

The United States takes seriously the potential problems from uncontrolled radioactive sources. To address these problems, the United States Department of State is leading the development of an initiative for International Radioactive Source Management (ISRM). The Department of State, through a number of Federal and state agencies, regulatory bodies and private industry, will endeavor to provide coordinated support to the international community, particularly through IAEA, to assist in the development and implementation of risk-based clearance levels to support import/export of radioactive contaminated metals and the tracking, management, identification, remediation, and disposition of 'lost sources' entering nation states and targeted industries. The United States believes that the international control of radioactive sources is critical in avoiding wide-spread contamination of the world metal supply. Thus the initiative has four objectives: (1) Protect sources from becoming lost (Tracking management); (2) Identify primary locations where sources have been lost (Stop future losses); (3) Locate lost sources (monitor and retrieve); and (4) Educate and train (deploy knowledge and technology). A number of efforts already underway in the United States support the overall initiative. The EPA has provided a grant to the Conference of Radiation Program Control Directors (CRCPD) to develop a nation-wide program for the disposition of orphaned radioactive sources. This program now has internet visibility and a toll-free telephone number to call for assistance in the disposal of sources. The Nuclear Regulatory Commission (NRC), the Department of Energy (DOE), and other government agencies as well as private companies are assisting CRCPD in this program. The NRC has begun a program to improve control of radioactive sources in the United States, and also intends to promulgate a regulation defining conditions for the release of materials from licensed facilities. The DOE is

Antiabortion violence in the United States.

Science.gov (United States)

Russo, Jennefer A; Schumacher, Kristin L; Creinin, Mitchell D

2012-11-01

This study was conducted to determine if an association exists between the amount of harassment and violence directed against abortion providers and the restrictiveness of state laws relating to family planning. We used responses from a July 2010 survey of 357 abortion providers in 50 states to determine their experience of antiabortion harassment and violence. Their responses were grouped and analyzed in relation to a published grading of state laws in the United States (A, B, C, D and F) as they relate to restrictions on family planning services. Group by group comparison of respondents illustrates that the difference in the number of reported incidents of minor vandalism by group is statistically significant (A vs. C, p=.07; A vs. D, p=.017; A vs. F, p=.0002). Incidents of harassment follow a similar pattern. There were no differences noted overall for violence or major vandalism. Major violence, including eight murders, is a new occurrence in the last two decades. Harassment of abortion providers in the United States has an association with the restrictiveness of state abortion laws. In the last two decades, murder of abortion providers has become an unfortunate part of the violence. Copyright © 2012 Elsevier Inc. All rights reserved.

Masturbation in the United States.

Science.gov (United States)

Das, Aniruddha

2007-01-01

Using data from the nationally representative National Health and Social Life Survey, this study queried the correlates of masturbation in the United States in 1992. Among those aged 18-60, 38% (CI, 35-41) of women and 61% (CI, 57-65) of men reported any masturbation over the preceding year. The system of factors underlying masturbation was similar for both genders, consistent with a convergence in gender patterns of sexual expression in the United States. Among both women and men, masturbation responded to a stable sexualized personality pattern, catalyzed by early-life factors and manifested in current sexual traits. Strikingly, the masturbation-partnered sex linkage, often conceptualized either as compensating for unsatisfying sex or complementing a satisfactory sex life, appeared to be bimodal for both genders. For some, masturbation complemented an active and pleasurable sex life, while among others, it compensated for a lack of partnered sex or satisfaction in sex.

Research on Anoplophora glabripennis in the United States

Science.gov (United States)

Robert A. Haack

2003-01-01

In the mid-1990s it was estimated that more than 400 exotic (non-native) forest insects had already become established in the United States (HAACK and BYLER, 1993; MATTSON et al., 1994; NIEMELA and MATTSON, 1996). This number has continued to grow with new exotics discovered annually in the United States (HAACK, 2002; HAACK and POLAND, 2001; HAACK et al., 2002). One...

Leading Causes of Death in Males United States, 2010

Science.gov (United States)

... What’s this? Submit What’s this? Submit Button Leading Causes of Death in Males and Females, United States Recommend on ... to current and previous listings for the leading causes of death for males and females in the United States. ...

76 FR 18198 - European Union-United States Atlantis Program

Science.gov (United States)

2011-04-01

... DEPARTMENT OF EDUCATION European Union-United States Atlantis Program AGENCY: Office of...)--Special Focus Competition: European Union-(EU) United States (U.S.) Atlantis Program Notice inviting... and Culture, European Commission for funding under a separate but parallel EU competition. Within this...

Development of Water Quality Modeling in the United States

Science.gov (United States)

This presentation describes historical trends in water quality model development in the United States, reviews current efforts, and projects promising future directions. Water quality modeling has a relatively long history in the United States. While its origins lie in the work...

Solar energy in the United States

International Nuclear Information System (INIS)

Ochoa, D.; Slaoui, A.; Soler, R.; Bermudez, V.

2009-01-01

Written by a group of five French experts who visited several research centres, innovating companies and solar power stations in the United States, this report first proposes an overview of solar energy in the United States, indicating and commenting the respective shares of different renewable energies in the production, focusing on the photovoltaic energy production and its RD sector. The second part presents industrial and research activities in the solar sector, and more specifically photovoltaic technologies (silicon and thin layer technology) and solar concentrators (thermal solar concentrators, photovoltaic concentrators). The last chapter presents the academic research activities in different universities (California Tech Beckman Institute, Stanford, National Renewable Energy Laboratory, Colorado School of Mines)

Production of butanol (a biofuel) from agricultural residues: Part II - Use of corn stover and switchgrass hydrolysates

Energy Technology Data Exchange (ETDEWEB)

Qureshi, Nasib; Saha, Badal C.; Hector, Ronald E.; Dien, Bruce; Iten, Loren; Bowman, Michael J.; Cotta, Michael A. [United States Department of Agriculture (USDA), Agricultural Research Service (ARS), National Center for Agricultural Utilization Research (NCAUR), Bioenergy Research, 1815 N. University Street, Peoria, IL 61604 (United States); Hughes, Stephen; Liu, Siqing [USDA-ARS-NCAUR, Renewable Product Technology, 1815 N. University Street, Peoria, IL 61604 (United States); Sarath, Gautam [USDA-ARS, Grain, Forage, and Bioenergy Research Unit, University of Nebraska, 314 Biochemistry Hall, East Campus, Lincoln, NE 68583 (United States)

2010-04-15

Acetone butanol ethanol (ABE) was produced from hydrolysed corn stover and switchgrass using Clostridium beijerinckii P260. A control experiment using glucose resulted in the production of 21.06 g L{sup -1} total ABE. In this experiment an ABE yield and productivity of 0.41 and 0.31 g L{sup -1} h{sup -1} was achieved, respectively. Fermentation of untreated corn stover hydrolysate (CSH) exhibited no growth and no ABE production; however, upon dilution with water (two fold) and wheat straw hydrolysate (WSH, ratio 1:1), 16.00 and 18.04 g L{sup -1} ABE was produced, respectively. These experiments resulted in ABE productivity of 0.17-0.21 g L{sup -1} h{sup -1}. Inhibitors present in CSH were removed by treating the hydrolysate with Ca(OH){sub 2} (overliming). The culture was able to produce 26.27 g L{sup -1} ABE after inhibitor removal. Untreated switchgrass hydrolysate (SGH) was poorly fermented and the culture did not produce more than 1.48 g L{sup -1} ABE which was improved to 14.61 g L{sup -1}. It is suggested that biomass pretreatment methods that do not generate inhibitors be investigated. Alternately, cultures resistant to inhibitors and able to produce butanol at high concentrations may be another approach to improve the current process. (author)

75 FR 22551 - United States Standards for Grades of Frozen Blueberries

Science.gov (United States)

2010-04-29

...] United States Standards for Grades of Frozen Blueberries AGENCY: Agricultural Marketing Service, USDA... United States Standards for Grades of Frozen Blueberries. After considering the comments received... . The United States Standards for Grades of Frozen Blueberries are available by accessing the AMS Web...

Diurnal Patterns of Heterotrophic and Autotrophic Soil Respiration in Maize and Switchgrass Bioenergy Cropping Systems

Science.gov (United States)

von Haden, A.; Marin-Spiotta, E.; Jackson, R. D.; Kucharik, C. J.

2016-12-01

A high proportion of carbon lost from terrestrial ecosystems occurs via soil CO2 respiration. Soil respiration is comprised of two contrasting sources: heterotrophic respiration (RH) from the decomposition of organic matter and autotrophic respiration (RA) from plant root metabolism. Since the two sources of soil respiration vary widely in their origin, the controls of each source are also likely to differ. However, the challenge of partitioning soil respiration sources in situ has limited our mechanistic understanding of RH and RA. Our objective was to evaluate the in situ diurnal controls of RH and RA in maize (Zea mays L.) and switchgrass (Panicum virgatum L.) bioenergy cropping systems. We hypothesized that both RH and RA would follow diurnal soil temperature trends, but that RA would also respond to diel patterns of photosynthetically active radiation (PAR). We also expected that diurnal soil respiration patterns would vary significantly within the growing season. We evaluated our hypothesis with six diurnal soil respiration campaigns during the 2015 and 2016 growing seasons at Arlington, WI, USA. RH showed clear oscillating diel trends, typically peaking in the mid-afternoon when near-surface soil temperatures were highest. Diurnal RA patterns were more nuanced than RH, but were generally highest in the late afternoon and showed the most pronounced diel trends during peak growing season in July. RA also tended to spike in concert with PAR, but this effect was much more prominent in maize than switchgrass. Continuing efforts will attempt to quantitatively separate the effects of soil temperature and PAR on RA.

77 FR 64031 - United States-Peru Trade Promotion Agreement

Science.gov (United States)

2012-10-18

... Trade Promotion Agreement AGENCIES: U.S. Customs and Border Protection, Department of Homeland Security... tariff treatment and other customs-related provisions of the United States-Peru Trade Promotion Agreement... other customs-related provisions of the United States-Peru Trade Promotion Agreement (PTPA). Please...

Inching toward incrementalism: federalism, devolution, and health policy in the United States and the United Kingdom.

Science.gov (United States)

Sparer, Michael S; France, George; Clinton, Chelsea

2011-02-01

In the United States, the recently enacted Patient Protection and Affordable Care Act of 2010 envisions a significant increase in federal oversight over the nation's health care system. At the same time, however, the legislation requires the states to play key roles in every aspect of the reform agenda (such as expanding Medicaid programs, creating insurance exchanges, and working with providers on delivery system reforms). The complicated intergovernmental partnerships that govern the nation's fragmented and decentralized system are likely to continue, albeit with greater federal oversight and control. But what about intergovernmental relations in the United Kingdom? What impact did the formal devolution of power in 1999 to Scotland, Wales, and Northern Ireland have on health policy in those nations, and in the United Kingdom more generally? Has devolution begun a political process in which health policy in the United Kingdom will, over time, become increasingly decentralized and fragmented, or will this "state of unions" retain its long-standing reputation as perhaps the most centralized of the European nations? In this article, we explore the federalist and intergovernmental implications of recent reforms in the United States and the United Kingdom, and we put forward the argument that political fragmentation (long-standing in the United States and just emerging in the United Kingdom) produces new intergovernmental partnerships that, in turn, produce incremental growth in overall government involvement in the health care arena. This is the impact of what can be called catalytic federalism.

THE UNITED STATES EDUCATIONAL SYSTEM

OpenAIRE

David Suriñach Fernández

2017-01-01

The United States educational system is very complex. Due to the fact a big number of agents take play of its regulation, the differences between the education from one State compared to the education from another, or even between school districts, might be considerable. The last two largest federal education initiatives, No Child Left Behind and Race to the Top, have had a huge impact on the American education system. The escalation of the standardized test throughout the whole country as a ...

Inventory of Power Plants in the United States, October 1992

Energy Technology Data Exchange (ETDEWEB)

1993-10-27

The Inventory of Power Plants in the United States is prepared annually by the Survey Management Division, Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), US Department of Energy (DOE). The purpose of this publication is to provide year-end statistics about electric generating units operated by electric utilities in the United States (the 50 States and the District of Columbia). The publication also provides a 10-year outlook of future generating unit additions. Data summarized in this report are useful to a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. Data presented in this report were assembled and published by the EIA to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended. The report is organized into the following chapters: Year in Review, Operable Electric Generating Units, and Projected Electric Generating Unit Additions. Statistics presented in these chapters reflect the status of electric generating units as of December 31, 1992.

78 FR 63052 - United States-Panama Trade Promotion Agreement

Science.gov (United States)

2013-10-23

...-Panama Trade Promotion Agreement AGENCY: U.S. Customs and Border Protection, Department of Homeland... Trade Promotion Agreement entered into by the United States and the Republic of Panama. DATES: Interim... and the Republic of Panama (the ``Parties'') signed the United States-Panama Trade Promotion Agreement...

United States Military in Central Asia: Beyond Operation Enduring Freedom

Science.gov (United States)

2009-10-23

Malinowski , advocacy director for Human Rights Watch, stated, “the United States is most effective in promoting liberty around the world when people...26 U.S. President, The National Security Strategy of the United States of America, page? 27 Thomas Malinowski , “Testimony

Impacts of managing perennial grasses in the northern Midwest United States for bioenergy on soil organic C and nitrous oxide emission

Science.gov (United States)

In the USA perennial grasses [e.g., switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman)] are proposed as cellulosic feedstock. Perennial grasses are often touted as being low input and as having a C-neutral foot print, but managing them as bioenergy feedstock means addin...

31 CFR Appendix D to Subpart A of... - United States Secret Service

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false United States Secret Service D...—United States Secret Service 1. In general. This appendix applies to the United States Secret Service. 2. Public reading room. The United States Secret Service will provide a room on an ad hoc basis when...

76 FR 68271 - To Modify the Harmonized Tariff Schedule of the United States

Science.gov (United States)

2011-11-03

... the Convention and do not run counter to the national economic interest of the United States. I have... United States obligations under the Convention and do not run counter to the national economic interest of the United States. 7. On June 6, 2003, the United States and Chile entered into the United States...

Human prion diseases in the United States.

Directory of Open Access Journals (Sweden)

Robert C Holman

Full Text Available BACKGROUND: Prion diseases are a family of rare, progressive, neurodegenerative disorders that affect humans and animals. The most common form of human prion disease, Creutzfeldt-Jakob disease (CJD, occurs worldwide. Variant CJD (vCJD, a recently emerged human prion disease, is a zoonotic foodborne disorder that occurs almost exclusively in countries with outbreaks of bovine spongiform encephalopathy. This study describes the occurrence and epidemiology of CJD and vCJD in the United States. METHODOLOGY/PRINCIPAL FINDINGS: Analysis of CJD and vCJD deaths using death certificates of US residents for 1979-2006, and those identified through other surveillance mechanisms during 1996-2008. Since CJD is invariably fatal and illness duration is usually less than one year, the CJD incidence is estimated as the death rate. During 1979 through 2006, an estimated 6,917 deaths with CJD as a cause of death were reported in the United States, an annual average of approximately 247 deaths (range 172-304 deaths. The average annual age-adjusted incidence for CJD was 0.97 per 1,000,000 persons. Most (61.8% of the CJD deaths occurred among persons >or=65 years of age for an average annual incidence of 4.8 per 1,000,000 persons in this population. Most deaths were among whites (94.6%; the age-adjusted incidence for whites was 2.7 times higher than that for blacks (1.04 and 0.40, respectively. Three patients who died since 2004 were reported with vCJD; epidemiologic evidence indicated that their infection was acquired outside of the United States. CONCLUSION/SIGNIFICANCE: Surveillance continues to show an annual CJD incidence rate of about 1 case per 1,000,000 persons and marked differences in CJD rates by age and race in the United States. Ongoing surveillance remains important for monitoring the stability of the CJD incidence rates, and detecting occurrences of vCJD and possibly other novel prion diseases in the United States.

Competitive Electricity Market Regulation in the United States: A Primer

Energy Technology Data Exchange (ETDEWEB)

Flores-Espino, Francisco [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chernyakhovskiy, Ilya [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chernyakhovskiy, Ilya [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, Mackay [National Grid, Warwick (United Kingdom)

2016-12-01

The electricity system in the United States is a complex mechanism where different technologies, jurisdictions and regulatory designs interact. Today, two major models for electricity commercialization operate in the United States. One is the regulated monopoly model, in which vertically integrated electricity providers are regulated by state commissions. The other is the competitive model, in which power producers can openly access transmission infrastructure and participate in wholesale electricity markets. This paper describes the origins, evolution, and current status of the regulations that enable competitive markets in the United States.

Health, United States, 2012: Men's Health

Science.gov (United States)

... Mailing List Previous Reports Suggested Citation Related Sites Purchase Health, United States Behavioral Health Report Children’s ... with Internet Explorer may experience difficulties in directly accessing links to Excel files ...

Dengue Fever in the United States

Centers for Disease Control (CDC) Podcasts

Dr. Amesh Adalja, an associate at the Center for Biosecurity and clinical assistant professor at the University of Pittsburgh School, of Medicine, discusses dengue fever outbreaks in the United States.

15 CFR 971.209 - Processing outside the United States.

Science.gov (United States)

2010-01-01

... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Processing outside the United States... THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR COMMERCIAL RECOVERY PERMITS Applications Contents § 971.209 Processing outside the United States. (a) Except as provided in this section...

Obesity: A United States Strategic Imperative

Science.gov (United States)

2013-04-01

States Department of Veterans Affairs 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) Dr. Thomas ...Army Ms. Karen Malebranche United States Department of Veterans Affairs Project Adviser Dr. Thomas Williams U.S. Army War...per American has increased by 57 pounds per year ( poultry representing 46 pounds).86 Surprisingly however, the percentage of calories from meat

Cholera in the United States

Centers for Disease Control (CDC) Podcasts

2011-11-08

Anna Newton, Surveillance Epidemiologist at CDC, discusses cholera that was brought to the United States during an outbreak in Haiti and the Dominican Republic (Hispaniola).  Created: 11/8/2011 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/8/2011.

The United States

International Nuclear Information System (INIS)

Art, R.J.

1991-01-01

This paper reports that at least in the national security arena, the outcomes of bureaucratic infighting and domestic political struggles are not determined wholly by what goes on with the state. Rather struggles among contending groups are greatly affected by what is perceived to be happening outside the nation. Because external conditions give greater potency to some domestic forces over other, the external environment is never neutral in its domestic impact. The decisions of the period 1950-53 discussed above illustrate the point. But so too do the decisions of 1947, 1960-61 and 1969-72. In the 1947 case, Soviet intransigence provoked US nuclear rearmament. In the 1960-61 case, extended deterrent considerations pushed the United States to preserve its again newly discovered nuclear superiority. In the 1969-72 case, a Soviet determination to remain equal forced US acceptance of nuclear equality. And perhaps the best evidence of all, the perpetuation of parity ended the US inclination to resort to nuclear brinkmanship. In each instance, concerns about relative position heavily affected nuclear choice. Finally, the events of the past three years testify to the effects of international events on domestic choice. Under the terms of the 1987 INF Treaty, the two superpowers decided to dismantle and destroy an entire class of missiles of intermediate range (500-3000 kilometers) that both had deployed in Europe in the 1970s and 1980s, and in their June 1990 joint statement on strategic nuclear weapons, President Gorbachev and Brush agreed to cut the number of Soviet and US long range nuclear forces by 30 per cent. This agreement marks a watershed in US-Soviet strategic arm negotiations because for the first time the United States and the Soviet Union agreed in principals to reduce the number of weapons aimed at one another. Between 1985 and 1990 the cold war was brought to a close

Malaria Surveillance - United States, 2015.

Science.gov (United States)

Mace, Kimberly E; Arguin, Paul M; Tan, Kathrine R

2018-05-04

Malaria in humans is caused by intraerythrocytic protozoa of the genus Plasmodium. These parasites are transmitted by the bite of an infective female Anopheles species mosquito. The majority of malaria infections in the United States occur among persons who have traveled to regions with ongoing malaria transmission. However, malaria is occasionally acquired by persons who have not traveled out of the country through exposure to infected blood products, congenital transmission, laboratory exposure, or local mosquitoborne transmission. Malaria surveillance in the United States is conducted to provide information on its occurrence (e.g., temporal, geographic, and demographic), guide prevention and treatment recommendations for travelers and patients, and facilitate transmission control measures if locally acquired cases are identified. This report summarizes confirmed malaria cases in persons with onset of illness in 2015 and summarizes trends in previous years. Malaria cases diagnosed by blood film microscopy, polymerase chain reaction, or rapid diagnostic tests are reported to local and state health departments by health care providers or laboratory staff members. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS), the National Notifiable Diseases Surveillance System (NNDSS), or direct CDC consultations. CDC reference laboratories provide diagnostic assistance and conduct antimalarial drug resistance marker testing on blood samples submitted by health care providers or local or state health departments. This report summarizes data from the integration of all NMSS and NNDSS cases, CDC reference laboratory reports, and CDC clinical consultations. CDC received reports of 1,517 confirmed malaria cases, including one congenital case, with an onset of symptoms in 2015 among persons who received their diagnoses in the United States. Although the number of

Malaria Surveillance - United States, 2014.

Science.gov (United States)

Mace, Kimberly E; Arguin, Paul M

2017-05-26

Malaria in humans is caused by intraerythrocytic protozoa of the genus Plasmodium. These parasites are transmitted by the bite of an infective female Anopheles mosquito. The majority of malaria infections in the United States occur among persons who have traveled to regions with ongoing malaria transmission. However, malaria is occasionally acquired by persons who have not traveled out of the country through exposure to infected blood products, congenital transmission, laboratory exposure, or local mosquitoborne transmission. Malaria surveillance in the United States is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers. This report summarizes cases in persons with onset of illness in 2014 and trends during previous years. Malaria cases diagnosed by blood film, polymerase chain reaction, or rapid diagnostic tests are reported to local and state health departments by health care providers or laboratory staff. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System, National Notifiable Diseases Surveillance System, or direct CDC consultations. CDC conducts antimalarial drug resistance marker testing on blood samples submitted by health care providers or local or state health departments. Data from these reporting systems serve as the basis for this report. CDC received reports of 1,724 confirmed malaria cases, including one congenital case and two cryptic cases, with onset of symptoms in 2014 among persons in the United States. The number of confirmed cases in 2014 is consistent with the number of confirmed cases reported in 2013 (n = 1,741; this number has been updated from a previous publication to account for delayed reporting for persons with symptom onset occurring in late 2013). Plasmodium falciparum, P. vivax, P. ovale, and P. malariae were identified in 66.1%, 13.3%, 5.2%, and 2.7% of cases, respectively

26 CFR 1.993-7 - Definition of United States.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 10 2010-04-01 2010-04-01 false Definition of United States. 1.993-7 Section 1.993-7 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Domestic International Sales Corporations § 1.993-7 Definition of United States...

26 CFR 49.4261-5 - Payments made outside the United States.

Science.gov (United States)

2010-04-01

... travel under section 4262(b), the tax imposed by section 4261(b), shall not apply unless the... made outside the United States for one-way or round-trip transportation between a point within the United States and a point outside the United States. (b) Transportation between two or more points in the...

42 CFR 455.21 - Cooperation with State Medicaid fraud control units.

Science.gov (United States)

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Cooperation with State Medicaid fraud control units... Detection and Investigation Program § 455.21 Cooperation with State Medicaid fraud control units. In a State with a Medicaid fraud control unit established and certified under subpart C of this part, (a) The...

Low birth weight in the United States.

Science.gov (United States)

Goldenberg, Robert L; Culhane, Jennifer F

2007-02-01

Pregnancy outcomes in the United States and other developed countries are considerably better than those in many developing countries. However, adverse pregnancy outcomes are generally more common in the United States than in other developed countries. Low-birth-weight infants, born after a preterm birth or secondary to intrauterine growth restriction, account for much of the increased morbidity, mortality, and cost. Wide disparities exist in both preterm birth and growth restriction among different population groups. Poor and black women, for example, have twice the preterm birth rate and higher rates of growth restriction than do most other women. Low birth weight in general is thought to place the infant at greater risk of later adult chronic medical conditions, such as diabetes, hypertension, and heart disease. Of interest, maternal thinness is a strong predictor of both preterm birth and fetal growth restriction. However, in the United States, several nutritional interventions, including high-protein diets, caloric supplementation, calcium and iron supplementation, and various other vitamin and mineral supplementations, have not generally reduced preterm birth or growth restriction. Bacterial intrauterine infections play an important role in the etiology of the earliest preterm births, but, at least to date, antibiotic treatment either before labor for risk factors such as bacterial vaginosis or during preterm labor have not consistently reduced the preterm birth rate. Most interventions have failed to reduce preterm birth or growth restriction. The substantial improvement in newborn survival in the United States over the past several decades is mostly due to better access to improved neonatal care for low-birth-weight infants.

31 CFR 594.315 - United States person; U.S. person.

Science.gov (United States)

2010-07-01

... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY GLOBAL TERRORISM SANCTIONS REGULATIONS General Definitions § 594.315 United States person; U.S. person. The term United States person or...

Stigma and abortion complications in the United States.

Science.gov (United States)

Harris, Lisa H

2012-12-01

Abortion is highly stigmatized in the United States and elsewhere. As a result, many women who seek or undergo abortion keep their decision a secret. In many regions of the world, stigma is a recognized contributor to maternal morbidity and mortality from unsafe abortion, even when abortion is legal. Women may self-induce abortion in ways that are dangerous, or seek unsafe clandestine abortion from inadequately trained health care providers out of fear that their sexual activity, pregnancy, or abortion will be exposed if they present to a safe, licensed facility. However, unsafe abortion rarely occurs in the United States, and accordingly, stigma as a cause of unsafe abortion in the United States context has not been described. I consider the relationship of stigma to two serious abortion complications experienced by U.S. patients. Both patients wished to keep their abortion decision a secret from family and friends, and in both cases, their inability to disclose their abortion contributed to life-threatening complications. The experiences of these patients suggest that availability of legal abortion services in the United States may not be enough to keep all women safe. The cases also challenge the rhetoric that "abortion hurts women," suggesting instead that abortion stigma hurts women.

Vanadium recycling in the United States in 2004

Science.gov (United States)

Goonan, Thomas G.

2011-01-01

As one of a series of reports that describe the recycling of metal commodities in the United States, this report discusses the flow of vanadium in the U.S. economy in 2004. This report includes a description of vanadium supply and demand in the United States and illustrates the extent of vanadium recycling and recycling trends. In 2004, apparent vanadium consumption, by end use, in the United States was 3,820 metric tons (t) in steelmaking and 232 t in manufacturing, of which 17 t was for the production of superalloys and 215 t was for the production of other alloys, cast iron, catalysts, and chemicals. Vanadium use in steel is almost entirely dissipative because recovery of vanadium from steel scrap is chemically impeded under the oxidizing conditions in steelmaking furnaces. The greatest amount of vanadium recycling is in the superalloy, other-alloy, and catalyst sectors of the vanadium market. Vanadium-bearing catalysts are associated with hydrocarbon recovery and refining in the oil industry. In 2004, 2,850 t of vanadium contained in alloy scrap and spent catalysts was recycled, which amounted to about 44 percent of U.S. domestic production. About 94 percent of vanadium use in the United States was dissipative (3,820 t in steel/4,050 t in steel+fabricated products).

The voluntary safeguards offer of the United States

International Nuclear Information System (INIS)

Houck, F.S.

1985-01-01

During negotiations of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) concerns were expressed by non-nuclear-weapon States that their acceptance of Agency safeguards would put them at a disadvantage vis-a-vis the nuclear-weapon States. To allay these concerns, the United States and the United Kingdom in December 1967 made voluntary offers to accept Agency safeguards on their peaceful nuclear activities. Subsequently, France made a voluntary offer, the safeguards agreement for which was approved by the IAEA Board of Governors in February 1978, with a view to encouraging acceptance of Agency safeguards by additional States. More recently, in February 1985 the Board approved the safeguards agreement for the voluntary offer of the USSR, made inter alia to encourage further acceptance of Agency safeguards. These safeguards agreements with nuclear-weapon-States have two important features in common: Namely, they result from voluntary offers to accept safeguards rather than from multilateral or bilateral undertakings, and they give the Agency the right but generally not an obligation to apply its safeguards. The agreements differ in certain respects, the most noteworthy of which is the scope of the nuclear activities covered by each offer. The agreements of the United States and United Kingdom are the broadest, covering all peaceful nuclear activities in each country. The safeguards agreement for the US voluntary offer has been in force since December 1980. Now is an appropriate time to review the experience with the agreement's implementation during its first four years, as well as its history and salient features

United States Navy DL Perspective

Science.gov (United States)

2010-08-10

United States Navy DL Perspective CAPT Hank Reeves Navy eLearning Project Director 10 August 2010 Report Documentation Page Form ApprovedOMB No...Marine Corps (USMC) Navy eLearning Ongoing Shared with USMC, Coast Guard 9 NeL Help Site https://ile-help.nko.navy.mil/ile/ https://s-ile

26 CFR 1.953-2 - Actual United States risks.

Science.gov (United States)

2010-04-01

... being the promotion of such sales to United States retail outlets by advertising in trade publications... 26 Internal Revenue 10 2010-04-01 2010-04-01 false Actual United States risks. 1.953-2 Section 1.953-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX...

31 CFR 595.315 - United States person; U.S. person.

Science.gov (United States)

2010-07-01

... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY TERRORISM SANCTIONS REGULATIONS General Definitions § 595.315 United States person; U.S. person. The term United States person or U.S...

United States Interagency Elevation Inventory (USIEI)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Interagency Elevation Inventory displays high-accuracy topographic and bathymetric data for the United States and its territories. The project is a...

China's international trade and air pollution in the United States.

Science.gov (United States)

Lin, Jintai; Pan, Da; Davis, Steven J; Zhang, Qiang; He, Kebin; Wang, Can; Streets, David G; Wuebbles, Donald J; Guan, Dabo

2014-02-04

China is the world's largest emitter of anthropogenic air pollutants, and measurable amounts of Chinese pollution are transported via the atmosphere to other countries, including the United States. However, a large fraction of Chinese emissions is due to manufacture of goods for foreign consumption. Here, we analyze the impacts of trade-related Chinese air pollutant emissions on the global atmospheric environment, linking an economic-emission analysis and atmospheric chemical transport modeling. We find that in 2006, 36% of anthropogenic sulfur dioxide, 27% of nitrogen oxides, 22% of carbon monoxide, and 17% of black carbon emitted in China were associated with production of goods for export. For each of these pollutants, about 21% of export-related Chinese emissions were attributed to China-to-US export. Atmospheric modeling shows that transport of the export-related Chinese pollution contributed 3-10% of annual mean surface sulfate concentrations and 0.5-1.5% of ozone over the western United States in 2006. This Chinese pollution also resulted in one extra day or more of noncompliance with the US ozone standard in 2006 over the Los Angeles area and many regions in the eastern United States. On a daily basis, the export-related Chinese pollution contributed, at a maximum, 12-24% of sulfate concentrations over the western United States. As the United States outsourced manufacturing to China, sulfate pollution in 2006 increased in the western United States but decreased in the eastern United States, reflecting the competing effect between enhanced transport of Chinese pollution and reduced US emissions. Our findings are relevant to international efforts to reduce transboundary air pollution.

Comparison of Plastic Surgery Residency Training in United States and China.

Science.gov (United States)

Zheng, Jianmin; Zhang, Boheng; Yin, Yiqing; Fang, Taolin; Wei, Ning; Lineaweaver, William C; Zhang, Feng

2015-12-01

Residency training is internationally recognized as the only way for the physicians to be qualified to practice independently. China has instituted a new residency training program for the specialty of plastic surgery. Meanwhile, plastic surgery residency training programs in the United States are presently in a transition because of restricted work hours. The purpose of this study is to compare the current characteristics of plastic surgery residency training in 2 countries. Flow path, structure, curriculum, operative experience, research, and evaluation of training in 2 countries were measured. The number of required cases was compared quantitatively whereas other aspects were compared qualitatively. Plastic surgery residency training programs in 2 countries differ regarding specific characteristics. Requirements to become a plastic surgery resident in the United States are more rigorous. Ownership structure of the regulatory agency for residency training in 2 countries is diverse. Training duration in the United States is more flexible. Clinical and research training is more practical and the method of evaluation of residency training is more reasonable in the United States. The job opportunities after residency differ substantially between 2 countries. Not every resident has a chance to be an independent surgeon and would require much more training time in China than it does in the United States. Plastic surgery residency training programs in the United States and China have their unique characteristics. The training programs in the United States are more standardized. Both the United States and China may complement each other to create training programs that will ultimately provide high-quality care for all people.

19 CFR 10.46 - Articles for the United States.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Articles for the United States. 10.46 Section 10... THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. General Provisions Articles for Institutions § 10.46 Articles for the United States. Pursuant to subheadings 9808.00.10 and 9808...

26 CFR 1.864-2 - Trade or business within the United States.

Science.gov (United States)

2010-04-01

... States, as his agent to effect transactions in the United States in stocks and securities for the account... A ordinarily effects transactions in the United States in stocks or securities. Under the agency..., effects transactions in the United States in stocks or securities for the partnership's own account or...

Taxation of United States general aviation

Science.gov (United States)

Sobieralski, Joseph Bernard

General aviation in the United States has been an important part of the economy and American life. General aviation is defined as all flying excluding military and scheduled airline operations, and is utilized in many areas of our society. The majority of aircraft operations and airports in the United States are categorized as general aviation, and general aviation contributes more than one percent to the United States gross domestic product each year. Despite the many benefits of general aviation, the lead emissions from aviation gasoline consumption are of great concern. General aviation emits over half the lead emissions in the United States or over 630 tons in 2005. The other significant negative externality attributed to general aviation usage is aircraft accidents. General aviation accidents have caused over 8000 fatalities over the period 1994-2006. A recent Federal Aviation Administration proposed increase in the aviation gasoline tax from 19.4 to 70.1 cents per gallon has renewed interest in better understanding the implications of such a tax increase as well as the possible optimal rate of taxation. Few studies have examined aviation fuel elasticities and all have failed to study general aviation fuel elasticities. Chapter one fills that gap and examines the elasticity of aviation gasoline consumption in United States general aviation. Utilizing aggregate time series and dynamic panel data, the price and income elasticities of demand are estimated. The price elasticity of demand for aviation gasoline is estimated to range from -0.093 to -0.185 in the short-run and from -0.132 to -0.303 in the long-run. These results prove to be similar in magnitude to automobile gasoline elasticities and therefore tax policies could more closely mirror those of automobile tax policies. The second chapter examines the costs associated with general aviation accidents. Given the large number of general aviation operations as well as the large number of fatalities and

Analysis of United States' Broadband Policy

National Research Council Canada - National Science Library

Uzarski, Joel S

2007-01-01

.... With every month that passes, the United States fails to close the gap in the digital divide both inside its borders as well as among the other countries that lead the world in broadband penetration...

Anti-Terrorism Authority Under the Laws of the United Kingdom and the United States

National Research Council Canada - National Science Library

Feikert, Clare; Doyle, Charles

2006-01-01

This is a comparison of the laws of the United Kingdom and of the United States that govern criminal and intelligence investigations of terrorist activities Both systems rely upon a series of statutory authorizations...

76 FR 38700 - United States, et al.

Science.gov (United States)

2011-07-01

... prices in advertisements, in-store displays, and online. Consumer World believes these rules should be... has ruled on that motion. I. Procedural History The United States and seven Plaintiff States filed the... Restraints result in higher merchant costs, and merchants generally pass costs on to consumers, retail prices...

75 FR 10561 - Pricing for 2010 United States Mint America the Beautiful QuartersTM

Science.gov (United States)

2010-03-08

... DEPARTMENT OF THE TREASURY United States Mint Pricing for 2010 United States Mint America the Beautiful Quarters\\TM\\ Two-Roll Set, etc. AGENCY: United States Mint, Department of the Treasury. ACTION: Notice. SUMMARY: The United States Mint is announcing the price of the 2010 United States Mint America...

Microbial nitrogen cycling response to forest-based bioenergy production.

Science.gov (United States)

Minick, Kevan J; Strahm, Brian D; Fox, Thomas R; Sucre, Eric B; Leggett, Zakiya H

2015-12-01

Concern over rising atmospheric CO2 and other greenhouse gases due to fossil fuel combustion has intensified research into carbon-neutral energy production. Approximately 15.8 million ha of pine plantations exist across the southeastern United States, representing a vast land area advantageous for bioenergy production without significant landuse change or diversion of agricultural resources from food production. Furthermore, intercropping of pine with bioenergy grasses could provide annually harvestable, lignocellulosic biomass feedstocks along with production of traditional wood products. Viability of such a system hinges in part on soil nitrogen (N) availability and effects of N competition between pines and grasses on ecosystem productivity. We investigated effects of intercropping loblolly pine (Pinus taeda) with switchgrass (Panicum virgatum) on microbial N cycling processes in the Lower Coastal Plain of North Carolina, USA. Soil samples were collected from bedded rows of pine and interbed space of two treatments, composed of either volunteer native woody and herbaceous vegetation (pine-native) or pure switchgrass (pine-switchgrass) in interbeds. An in vitro 15N pool-dilution technique was employed to quantify gross N transformations at two soil depths (0-5 and 5-15 cm) on four dates in 2012-2013. At the 0-5 cm depth in beds of the pine-switchgrass treatment, gross N mineralization was two to three times higher in November and February compared to the pine-native treatment, resulting in increased NH4(+) availability. Gross and net nitrification were also significantly higher in February in the same pine beds. In interbeds of the pine-switchgrass treatment, gross N mineralization was lower from April to November, but higher in February, potentially reflecting positive effects of switchgrass root-derived C inputs during dormancy on microbial activity. These findings indicate soil N cycling and availability has increased in pine beds of the pine-switchgrass

78 FR 77103 - United States Travel and Tourism Advisory Board

Science.gov (United States)

2013-12-20

... DEPARTMENT OF COMMERCE International Trade Administration United States Travel and Tourism... extended deadline for application for membership on the United States Travel and Tourism Advisory Board... Travel and Tourism Advisory Board (Board). The November 25, 2013 notice provided that all applications...

State of pine decline in the southeastern United States

Science.gov (United States)

Lori Eckhardt; Mary Anne Sword Sayer; Don Imm

2010-01-01

Pine decline is an emerging forest health issue in the southeastern United States. Observations suggest pine decline is caused by environmental stress arising from competition, weather, insects and fungi, anthropogenic disturbances, and previous management. The problem is most severe for loblolly pine on sites that historically supported longleaf pine, are highly...

78 FR 53426 - United States Travel and Tourism Advisory Board Charter Renewal

Science.gov (United States)

2013-08-29

... DEPARTMENT OF COMMERCE International Trade Administration United States Travel and Tourism... for the United States Travel and Tourism Advisory Board on August 19, 2013. DATES: The Charter for the United States Travel and Tourism Advisory Board was renewed on August 19, 2013. FOR FURTHER INFORMATION...

Summary of Notifiable Diseases, United States. Volume 45, Number 53.

Science.gov (United States)

1997-10-31

Trichinosis Tuberculosis Typhoid fever Yellow fever NOTE: Although varicella is not a nationally notifiable disease, the Council of State and...plague among humans, two of which were fatal, were re- ported in the United States (two cases in Arizona, one in Colorado, and two in New Mexico ). Both...13 cases per year) were reported in the United States. Of these cases, 80% occurred in the southwestern states of New Mexico , Arizona, and

Forest carbon management in the United States: 1600-2100

Science.gov (United States)

Richard A. Birdsey; Kurt Pregitzer; Alan Lucier

2006-01-01

This paper reviews the effects of past forest management on carbon stocks in the United States, and the challenges for managing forest carbon resources in the 21st century. Forests in the United States were in approximate carbon balance with the atmosphere from 1600-1800. Utilization and land clearing caused a large pulse of forest carbon emissions during the 19th...

NCHS - Births and General Fertility Rates: United States

Data.gov (United States)

U.S. Department of Health & Human Services — This dataset includes crude birth rates and general fertility rates in the United States since 1909. The number of states in the reporting area differ historically....

Green electricity policies in the United States: case study

International Nuclear Information System (INIS)

Menz, Fredric C.

2005-01-01

While there has been interest in promoting the use of renewable energy in electricity production for a number of years in the United States, the market share of non-hydro renewable energy sources in electricity production has remained at about 2 percent over the past decade. The paper reviews the principal energy resources used for electricity production, considers the changing regulatory environment for the electricity industry, and describes government policies that have been used to promote green electricity in the United States, with an emphasis on measures adopted by state governments. Factors influencing the development of green power markets are also discussed, including underlying economic issues, public policy measures, the regulatory environment, external costs, and subsidies. Without significant increases in fossil fuel prices, much more stringent environmental regulations, or significant changes in electricity customer preferences, green electricity markets are likely to develop slowly in the United States

78 FR 70275 - United States Travel and Tourism Advisory Board

Science.gov (United States)

2013-11-25

... DEPARTMENT OF COMMERCE International Trade Administration United States Travel and Tourism... an opportunity to apply for membership on the United States Travel and Tourism Advisory Board... Travel and Tourism Advisory Board (Board). The purpose of the Board is to advise the Secretary of...

Veterinary Fusarioses within the United States

Science.gov (United States)

Multilocus DNA sequence data was used to retrospectively assess the genetic diversity and evolutionary relationships of 67 Fusarium strains from veterinary sources, most of which were from the United States. Molecular phylogenetic analyses revealed that the strains comprised 23 phylogenetically dist...

Low-level radioactive waste disposal technologies used outside the United States

International Nuclear Information System (INIS)

Templeton, K.J.; Mitchell, S.J.; Molton, P.M.; Leigh, I.W.

1994-01-01

Low-level radioactive waste (LLW) disposal technologies are an integral part of the waste management process. In the United States, commercial LLW disposal is the responsibility of the State or groups of States (compact regions). The United States defines LLW as all radioactive waste that is not classified as spent nuclear fuel, high- level radioactive waste, transuranic waste, or by-product material as defined in Section II(e)(2) of the Atomic Energy Act. LLW may contain some long-lived components in very low concentrations. Countries outside the United States, however, may define LLW differently and may use different disposal technologies. This paper outlines the LLW disposal technologies that are planned or being used in Canada, China, Finland, France, Germany, Japan, Sweden, Taiwan, and the United Kingdom (UK)

Pakistan: Can the United States Secure an Insecure State?

Science.gov (United States)

2010-01-01

do not have female staff; the male-to-female staff ratio in the health field is 7 to 1.130 More nurses and female staff are needed, especially to...exercise was rescheduled for 2009. 9 Interview with Ninth Air Force personnel, September 12, 2008. 200 Pakistan: Can the United States Secure an Insecure

The hydroelectric power market in the United States

International Nuclear Information System (INIS)

2002-01-01

The second-largest producer of hydroelectric power in the world is the United States, right after Canada. In the United States, 7.1 per cent of net electricity generation was attributed to hydroelectric power in 2000, which totalled 269 terawatt hours (TWh). Aging facilities, outdated technology in some facilities, a cumbersome licensing process, and increasing environmental demands from interest groups for the preservation of river systems and surrounding wildlife challenge the industry. Pacific Coast states, especially California, were faced with electric power shortages during the summer of 2001, due to low market prices, high power usage among consumers and drought. The problems with the deregulation of the electricity market were brought to light by these shortages. Legislation to restructure the electric power industry in 25 states had not been enacted as of January 2002. The purchase of more power from both Canada and the Mexico is being considered by the government of the United States, as is the creation of a national power grid to allow for power transmission throughout the country. The Canada-United States energy trade might be affected by such a move, and result in project construction opportunities for Canadian companies. Renewable energy sources must be responsible for the generation of 10 per cent of power generation levels by 2020, on a gradual basis as mandated by law. By 2005, New York City must purchase 10 per cent of its power from renewable energy sources, reaching 20 per cent by 2010. The repair and replacement of aging dam equipment, the development of advanced turbine technology to protect fish stocks and water quality, dam removal, the construction of power lines are all opportunities open to Canadian companies. 60 refs., 5 tabs

Research and photovoltaic industry at the United States

International Nuclear Information System (INIS)

Lerouge, Ch.; Herino, R.; Delville, R.; Allegre, R.

2006-06-01

For a big country as the United States, the solar energy can be a solution for the air quality improvement, the greenhouse gases fight and the reduction of the dependence to the imported petroleum and also for the economic growth by the increase of the employment in the solar industry sector. This document takes stock on the photovoltaic in the United States in the industrial and research domains. The american photovoltaic industry is the third behind the Japan and the Germany. (A.L.B.)

State cigarette minimum price laws - United States, 2009.

Science.gov (United States)

2010-04-09

Cigarette price increases reduce the demand for cigarettes and thereby reduce smoking prevalence, cigarette consumption, and youth initiation of smoking. Excise tax increases are the most effective government intervention to increase the price of cigarettes, but cigarette manufacturers use trade discounts, coupons, and other promotions to counteract the effects of these tax increases and appeal to price-sensitive smokers. State cigarette minimum price laws, initiated by states in the 1940s and 1950s to protect tobacco retailers from predatory business practices, typically require a minimum percentage markup to be added to the wholesale and/or retail price. If a statute prohibits trade discounts from the minimum price calculation, these laws have the potential to counteract discounting by cigarette manufacturers. To assess the status of cigarette minimum price laws in the United States, CDC surveyed state statutes and identified those states with minimum price laws in effect as of December 31, 2009. This report summarizes the results of that survey, which determined that 25 states had minimum price laws for cigarettes (median wholesale markup: 4.00%; median retail markup: 8.00%), and seven of those states also expressly prohibited the use of trade discounts in the minimum retail price calculation. Minimum price laws can help prevent trade discounting from eroding the positive effects of state excise tax increases and higher cigarette prices on public health.

75 FR 78338 - Meeting of the United States-Oman Joint Forum on Environmental Cooperation Pursuant to the United...

Science.gov (United States)

2010-12-15

... DEPARTMENT OF STATE [Public Notice 7261] Meeting of the United States-Oman Joint Forum on Environmental Cooperation Pursuant to the United States-Oman Memorandum of Understanding on Environmental Cooperation ACTION: Notice of the meeting of the U.S.-Oman Joint Forum on Environmental Cooperation and...

77 FR 27669 - Modifications to Definition of United States Property

Science.gov (United States)

2012-05-11

... contracts. The temporary regulations provide that certain obligations of United States persons arising from upfront payments made by controlled foreign corporations pursuant to contracts that are cleared by a... the meaning of section 956(c)) for obligations of United States persons arising from certain upfront...

Contemporary United States Foreign Policy Towards Indonesia

National Research Council Canada - National Science Library

McAslan, Hugh

2004-01-01

United States national interests in Indonesia have traditionally being based on strategic security requirements given Indonesia's geographic location between the Indian and Pacific Oceans, and strong...

Employers mexican migrants in the United States

Directory of Open Access Journals (Sweden)

Eduardo Fernández Guzmán

2013-09-01

Full Text Available You might think that by definition the migrant labor plays in less profitable niches and meager social mobility. However, a large group of migrants in different economically developed countries have successfully launched businesses of diverse nature and volume. This is why entrepreneurship of migrants is an issue that has received increasing attention in recent years. Compared to other immigrant groups in the United States, Mexicans show low levels of entrepreneurial activity. The aim of this paper is to, through a general literature review of official statistical data, a preliminary analysis of mexican migrant entrepreneurship in the United States, that is to say in recent years has been growing in importance.

Motorcycle trends in the United States

Science.gov (United States)

2009-05-01

During the last decade there has been a significant increase in the number of motorcycle sales and registrations in the United States. At the same time there has been a shift in the demographics of motorcycle users and increased focus on motorcycle s...

THE UNITED STATES AND NIGERIAN RELATIONS:

African Journals Online (AJOL)

Mrs. I.D

2009-12-25

Dec 25, 2009 ... response from the Nigerian government. ... domestic crises that negatively impacts state stability, the US government ... Harrison C. Ajebon, Department of Political Science, University of Calabar, ..... Sweden. United Kingdom. Switzerland. Asia & far East. Japan ..... case Study of Nigeria, in Ikonnechidi and.

37 CFR 1.416 - The United States International Preliminary Examining Authority.

Science.gov (United States)

2010-07-01

... STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES International Processing Provisions General Information § 1.416 The United States International Preliminary... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false The United States...

31 CFR Appendix C to Subpart C of... - United States Customs Service

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false United States Customs Service C... Customs Service 1. In general. This appendix applies to the United States Customs Service. It sets forth... records and accounting of disclosures. (a) For records which are maintained at the United States Customs...

The State of Homeless Children in the United States

Science.gov (United States)

Kabler, Brenda; Weinstein, Elana

2009-01-01

Across America, the numbers of homeless children and families are growing as a result of many factors including the recent economic crisis, home foreclosures, and natural disasters. Because of an increase in the number of homeless children throughout the United States, this population has unmet needs that can be targeted in school settings under…

78 FR 53478 - Proposed Information Collection; United States Park Police Personal History Statement

Science.gov (United States)

2013-08-29

...] Proposed Information Collection; United States Park Police Personal History Statement AGENCY: National Park... about this IC, contact Major Scott Fear, United States Park Police, 1100 Ohio Drive SW., Washington, DC... INFORMATION: I. Abstract The United States Park Police (USPP) is a unit of the National Park Service...

44 CFR 351.26 - The United States Department of Agriculture.

Science.gov (United States)

2010-10-01

... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false The United States Department of Agriculture. 351.26 Section 351.26 Emergency Management and Assistance FEDERAL EMERGENCY... PREPAREDNESS Interagency Assignments § 351.26 The United States Department of Agriculture. (a) Assist FEMA in...

Fragmented patterns of flood change across the United States

Science.gov (United States)

Archfield, Stacey A.; Hirsch, Robert M.; Viglione, A.; Blöschl, G.

2016-01-01

Trends in the peak magnitude, frequency, duration, and volume of frequent floods (floods occurring at an average of two events per year relative to a base period) across the United States show large changes; however, few trends are found to be statistically significant. The multidimensional behavior of flood change across the United States can be described by four distinct groups, with streamgages experiencing (1) minimal change, (2) increasing frequency, (3) decreasing frequency, or (4) increases in all flood properties. Yet group membership shows only weak geographic cohesion. Lack of geographic cohesion is further demonstrated by weak correlations between the temporal patterns of flood change and large-scale climate indices. These findings reveal a complex, fragmented pattern of flood change that, therefore, clouds the ability to make meaningful generalizations about flood change across the United States.

Media Education in the United States: A Check under the "Gestalt" Hood.

Science.gov (United States)

Phillips, Melissa

1998-01-01

Examines four commonalities of media education in the United States. Outlines the four ideological perspectives that in fact guide media education in the United States: celebration, protectionism, cultural criticism, and educated consumerism. Suggests what all of this means for the future of media education in the United States and what will be…

7 CFR 58.2825 - United States Standard for ice cream.

Science.gov (United States)

2010-01-01

... AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT... DAIRY PRODUCTS 1 United States Department of Agriculture Standard for Ice Cream § 58.2825 United States... from the use of bulky optional ingredients, chocolate and cocoa solids used shall be considered the...

22 CFR 61.8 - Coordination with United States Customs Service.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Coordination with United States Customs Service... FREE FLOW OF AUDIO-VISUAL MATERIALS § 61.8 Coordination with United States Customs Service. (a) Nothing in this part shall preclude examination of imported materials pursuant to the Customs laws and...

49 CFR 24.208 - Aliens not lawfully present in the United States.

Science.gov (United States)

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Aliens not lawfully present in the United States... Requirements § 24.208 Aliens not lawfully present in the United States. (a) Each person seeking relocation... of an individual, that he or she is either a citizen or national of the United States, or an alien...

Environmental performance reviews: United States

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-01-15

This book presents OECD assessments and recommendations regarding the United States' effort to manage its environment including air, water nature, and biodiversity to do this in a sustainable manner; and to do this in co-operation with its global neighbours. In particular, it assesses progress made since 1996, when OECD's previous review on the US was done. 40 figs., 21 tabs.

Consumer bankruptcy law for Ethiopia: Lessons from United States ...

African Journals Online (AJOL)

After deregulation of consumer credit and resultant availability, ... Germany, United States, United Kingdom and France are some of the countries ... social insurance, development policy and rehabilitative function of discharge and fresh start.

United States - Japanese nuclear relations: implications for the pacific region

International Nuclear Information System (INIS)

Suttmeier, R.P.

1980-01-01

The initiation of a new approach to non-proliferation policy by the United States in 1977 was the most upsetting development in the history of US-Japanese nuclear relations. The policy has seemingly altered Japanese views of its own nuclear future very little, yet it has altered the tone of the nuclear relationship with the United States. Recent Japanese nuclear power developments, both technical and administrative, are outlined and the prospects for the future of the United States-Japanese nuclear relationship and for Pacific regional cooperation assessed. Issues of importance in the relationship include reprocessing - enrichment, plutonium management, spent fuel and waste management and uranium supplies

46 CFR 153.12 - IMO Certificates for United States Ships.

Science.gov (United States)

2010-10-01

... 8, or the Officer in Charge, Marine Inspection, issues a United States ship an IMO Certificate... 46 Shipping 5 2010-10-01 2010-10-01 false IMO Certificates for United States Ships. 153.12 Section... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS General § 153.12...

China’s international trade and air pollution in the United States

Science.gov (United States)

Lin, Jintai; Pan, Da; Davis, Steven J.; Zhang, Qiang; He, Kebin; Wang, Can; Streets, David G.; Wuebbles, Donald J.; Guan, Dabo

2014-01-01

China is the world’s largest emitter of anthropogenic air pollutants, and measurable amounts of Chinese pollution are transported via the atmosphere to other countries, including the United States. However, a large fraction of Chinese emissions is due to manufacture of goods for foreign consumption. Here, we analyze the impacts of trade-related Chinese air pollutant emissions on the global atmospheric environment, linking an economic-emission analysis and atmospheric chemical transport modeling. We find that in 2006, 36% of anthropogenic sulfur dioxide, 27% of nitrogen oxides, 22% of carbon monoxide, and 17% of black carbon emitted in China were associated with production of goods for export. For each of these pollutants, about 21% of export-related Chinese emissions were attributed to China-to-US export. Atmospheric modeling shows that transport of the export-related Chinese pollution contributed 3–10% of annual mean surface sulfate concentrations and 0.5–1.5% of ozone over the western United States in 2006. This Chinese pollution also resulted in one extra day or more of noncompliance with the US ozone standard in 2006 over the Los Angeles area and many regions in the eastern United States. On a daily basis, the export-related Chinese pollution contributed, at a maximum, 12–24% of sulfate concentrations over the western United States. As the United States outsourced manufacturing to China, sulfate pollution in 2006 increased in the western United States but decreased in the eastern United States, reflecting the competing effect between enhanced transport of Chinese pollution and reduced US emissions. Our findings are relevant to international efforts to reduce transboundary air pollution. PMID:24449863

The United States and world energy markets

International Nuclear Information System (INIS)

Ramsay, W.C.

1992-01-01

The United States, dominating the world's energy markets as a producer and consumer, is sensitive to changes in this market and intends to influence the development of global energy policy. Supply will be increased by nations such as Venezuela, Indonesia and perhaps in the future a United Yemen and the Commonwealth of Independent States, moving to freer market economies which will allow investment opportunities previously inaccessible to foreign companies. Although world energy demand will grow, little of this will be in the US where, under the National Energy Strategy, comprehensive measures are being introduced to improve energy efficiency. The US energy security will be further improved by such measures as diversification of supply, larger domestic production and increasing interdependence between suppliers, traders and consumers. (author)

The financial burden of out-of-pocket expenses in the United States and Canada: How different is the United States?

Directory of Open Access Journals (Sweden)

Katherine E Baird

2016-01-01

Full Text Available Background: This article compares the burden that medical cost-sharing requirements place on households in the United States and Canada. It estimates the probability that individuals with similar demographic features in the two countries have large medical expenses relative to income. Method: The study uses 2010 nationally representative household survey data harmonized for cross-national comparisons to identify individuals with high medical expenses relative to income. Using logistic regression, it estimates the probability of high expenses occurring among 10 different demographic groups in the two countries. Results: The results show the risk of large medical expenses in the United States is 1.5–4 times higher than it is in Canada, depending on the demographic group and spending threshold used. The United States compares least favorably when evaluating poorer citizens and when using a higher spending threshold. Conclusion: Recent health care reforms can be expected to reduce Americans’ catastrophic health expenses, but it will take very large reductions in out-of-pocket expenditures—larger than can be expected—if poorer and middle-class families are to have the financial protection from high health care costs that their counterparts in Canada have.

GEOPOLITICS AND TRANSPORTATION. UNITED STATES AND PANAMA CANAL

Directory of Open Access Journals (Sweden)

Benea Ciprian Beniamin

2009-05-01

Full Text Available This article presents the great connection which exists between the realization of Panama Canal and the rising power on United States; and how this state, after the construction of this canal, could promote efficiently at global level its interests.

Improving the United States' Strategic Communication Strategy

National Research Council Canada - National Science Library

Risberg, Robert H

2008-01-01

...? Much of the answer to this question is the failure of the United States Government to effectively use strategic communication to inform and influence populations to recognize the value of American...

Nickel recycling in the United States in 2004

Science.gov (United States)

Goonan, Thomas G.

2009-01-01

As one of a series of reports that describe the recycling of metal commodities in the United States, this report discusses the flow of nickel from production through distribution and use, with particular emphasis on the recycling of industrial scrap (new scrap) and used products (old scrap) in 2004. This materials flow study includes a description of nickel supply and demand for the United States to illustrate the extent of nickel recycling and to identify recycling trends. Understanding how materials flow from a source through disposition can aid in improving the management of natural resource delivery systems. In 2004, the old scrap recycling efficiency for nickel was estimated to be 56.2 percent. In 2004, nickel scrap consumption in the United States was as follows: new scrap containing 13,000 metric tons (t) of nickel (produced during the manufacture of products), 12 percent; and old scrap containing 95,000 t of nickel (articles discarded after serving a useful purpose), 88 percent. The recycling rate for nickel in 2004 was 40.9 percent, and the percentage of nickel in products attributed to nickel recovered from nickel-containing scrap was 51.6 percent. Furthermore, U.S. nickel scrap theoretically generated in 2004 had the following distribution: scrap to landfills, 24 percent; recovered and used scrap, 50 percent; and unaccounted for scrap, 26 percent. Of the 50 percent of old scrap generated in the United States that was recovered and then used in 2004, about one-third was exported and two-thirds was consumed in the domestic production of nickel-containing products.

School Autonomy: A Comparison between China and the United States

Science.gov (United States)

Xia, Jiangang; Gao, Xingyuan; Shen, Jianping

2017-01-01

This study examined and compared school autonomy in China and the United States. Based on the international PISA 2012 school data, the authors examined three aspects of school autonomy. We found that in comparison with the United States, (1) principals from China were less likely to have responsibility over eleven school decisions (hiring…

6 CFR 13.45 - Deposit in Treasury of United States.

Science.gov (United States)

2010-01-01

... 6 Domestic Security 1 2010-01-01 2010-01-01 false Deposit in Treasury of United States. 13.45 Section 13.45 Domestic Security DEPARTMENT OF HOMELAND SECURITY, OFFICE OF THE SECRETARY PROGRAM FRAUD CIVIL REMEDIES § 13.45 Deposit in Treasury of United States. All amounts collected pursuant to this part...

14 CFR 47.7 - United States citizens and resident aliens.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false United States citizens and resident aliens... AIRCRAFT AIRCRAFT REGISTRATION General § 47.7 United States citizens and resident aliens. (a) U.S. citizens... the application. (b) Resident aliens. An applicant for aircraft registration under 49 U.S.C. 44102 who...