Headwater fish population responses to planting grass filter strips adjacent to channelized agricultural headwater streams

USDA-ARS?s Scientific Manuscript database

Grass filter strips are a widely used conservation practice in the Midwestern United States for reducing nutrient, pesticide, and sediment inputs into agricultural streams. Only a limited amount of information is available on the ecological effects of planting grass filter strips adjacent to channe...

An assessment of buffer strips for improving damage tolerance

NASA Technical Reports Server (NTRS)

Poe, C. C., Jr.; Kennedy, J. M.

1981-01-01

Graphite/epoxy panels with buffer strips were tested in tension to measure their residual strength with crack-like damage. Panels were made with 45/0/-45/90(2S) and 45/0/450(2S) layups. The buffer strips were parallel to the loading directions. They were made by replacing narrow strips of the 0 deg graphite plies with strips of either 0 deg S-Glass/epoxy or Kevlar-49/epoxy on either a one for one or a two for one basis. In a third case, O deg graphite/epoxy was used as the buffer material and thin, perforated Mylar strips were placed between the 0 deg piles and the cross-plies to weaken the interfaces and thus to isolate the 0 deg plies. Some panels were made with buffer strips of different widths and spacings. The buffer strips arrested the cracks and increased the residual strengths significantly over those plain laminates without buffer strips. A shear-lag type stress analysis correctly predicted the effects of layups, buffer material, buffer strip width and spacing, and the number of plies of buffer material.

An assessment of buffer strips for improving damage tolerance of composite laminates

NASA Technical Reports Server (NTRS)

Poe, C. C., Jr.; Kennedy, J. M.

1980-01-01

Graphite/epoxy panels with buffer strips were tested in tension to measure their residual strength with crack-like damage. Panels were made with (45/0/-45/90)2S and (45/0/-45/0)2S layups. The buffer strips were parallel to the loading direction. They were made by replacing narrow strips of the 0 deg graphite plies with strips of either 0 deg S-Glass/epoxy or Kevlar-90/epoxy on either a one-for-one or a two-for-one basis. In a third case, 0 deg graphite/epoxy was used as the buffer material and thin, perforated Mylar strips were placed between the 0 deg plies and the cross-plies to weaken the interfaces and thus to isolate the 0 deg plies. Some panels were made with buffer strips of different width and spacings. The buffer strips arrested the cracks and increased the residual strengths significantly over those of plain laminates without buffer strips. A shear-lag type stress analysis correctly predicted the effects of layup, buffer material, buffer strip width and spacing, and the number of plies of buffer material

An assessment of buffer strips for improving damage tolerance of composite laminates at elevated temperature

NASA Technical Reports Server (NTRS)

Bigelow, C. A.

1981-01-01

Buffer strips greatly improve the damage tolerance of graphite/epoxy laminates loaded in tension. Graphite/polyimide buffer strip panels were made and tested to determine their residual strength at ambient and elevated (177 C) temperature. Each panel was cut in the center to represent damage. Panels were radiographed and crack-opening displacements were recorded to indicate fracture, fracture arrest, and the extent of damage in the buffer strip after arrest. All panels had the same buffer strip spacing and width. The buffer strip material was 0 deg S-glass/PMR-15. The buffer strips were made by replacing narrow strips of the 0 deg graphite plies with strips of the 0 deg S-glass on either a one-for-one or a two-for-one basis. Half of the panels were heated to 177 + or - 3 C before and during the testing. Elevated temperature did not alter the fracture behavior of the buffer configuration.

Buffer strips in composites at elevated temperature

NASA Technical Reports Server (NTRS)

Bigelow, C. A.

1983-01-01

The composite material 'buffer strip' concept is presently investigated at elevated temperatures for the case of graphite/polyimide buffer strip panels using a (45/0/45/90)2S layup, where the buffer strip material was 0-deg S-glass/polyimide. Each panel was loaded in tension until it failed, and radiographs and crack opening displacements were recorded during the tests to determine fracture onset, fracture arrest, and the extent of damage in the buffer strip after crack arrest. At 177 + or - 3 C, the buffer strips increased the panel strength by at least 40 percent in comparison with panels without buffer strips. Compared to similar panels tested at room temperature, those tested at elevated temperature had lower residual strengths, but higher failure strains.

Sulfamethazine Sorption to Soil: Vegetative Management, pH, and Dissolved Organic Matter Effects.

PubMed

Chu, Bei; Goyne, Keith W; Anderson, Stephen H; Lin, Chung-Ho; Lerch, Robert N

2013-01-01

Elucidating veterinary antibiotic interactions with soil is important for assessing and mitigating possible environmental hazards. The objectives of this study were to investigate the effects of vegetative management, soil properties, and >1000 Da dissolved organic matter (DOM) on sulfamethazine (SMZ) behavior in soil. Sorption experiments were performed over a range of SMZ concentrations (2.5-50 μmol L) using samples from three soils (Armstrong, Huntington, and Menfro), each planted to one of three vegetation treatments: agroforestry buffers strips (ABS), grass buffer strips (GBS), and row crops (RC). Our results show that SMZ sorption isotherms are well fitted by the Freundlich isotherm model (log = 0.44-0.93; Freundlich nonlinearity parameter = 0.59-0.79). Further investigation of solid-to-solution distribution coefficients () demonstrated that vegetative management significantly ( < 0.05) influences SMZ sorption (ABS > GBS > RC). Multiple linear regression analyses indicated that organic carbon (OC) content, pH, and initial SMZ concentration were important properties controlling SMZ sorption. Study of the two most contrasting soils in our sample set revealed that increasing solution pH (pH 6.0-7.5) reduced SMZ sorption to the Armstrong GBS soil, but little pH effect was observed for the Huntington GBS soil containing 50% kaolinite in the clay fraction. The presence of DOM (150 mg L OC) had little significant effect on the Freundlich nonlinearity parameter; however, DOM slightly reduced SMZ values overall. Our results support the use of vegetative buffers to mitigate veterinary antibiotic loss from agroecosystems, provide guidance for properly managing vegetative buffer strips to increase SMZ sorption, and enhance understanding of SMZ sorption to soil. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Fracture and crack growth in orthotropic laminates

NASA Technical Reports Server (NTRS)

Goree, James G.; Kaw, Autar K.

1985-01-01

A mathematical model based on the classical shear-lag assumptions is used to study the residual strength and fracture behavior of composite laminates with symmetrically placed buffer strips. The laminate is loaded by a uniform remote longitudinal tensile strain and has initial damage in the form of a transverse crack in the parent laminate between buffer strips. The crack growth behavior as a function of material properties, number of buffer-strip plies, spacing, width of buffer strips, longitudinal matrix splitting, and debonding at the interface is studied. Buffer-strip laminates are shown to arrest fracture and increase the residual strengths significantly over those of one material laminates, with S-glass being a more effective buffer strip material than Kevlar in increasing the damage tolerance of graphite/epoxy panels. For a typical graphite/epoxy laminate with S-glass buffer-strips, the residual strength is about 2.4 times the residual strength of an all graphite/epoxy panel with the same crack length. Approximately 50% of this increase is due to the S-glass/epoxy buffer-strips, 40% due to longitudinal splitting of the buffer strip interface and 10% due to bonding.

Buffer strip design for protecting water quality and fish habitat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belt, G.H.; O'Laughlin, J.

1994-04-01

Buffer strips are protective areas adjacent to streams or lakes. Among other functions, they protect water quality and fish habitat. A typical buffer strip is found in western Oregon, where they are called Riparian Management Areas (RMAs). The authors use the term buffer strip to include functional descriptions such as filter, stabilization, or leave strips, and administrative designations such as Idaho's Stream Protection Zone (SPZ), Washington's Riparian Management Zone (RMZ), and the USDA Forest Service's Streamside Management Zone (SMZ). They address water quality and fishery protective functions of buffer strips on forestlands, pointing out improvements in buffer strip design possiblemore » through research or administrative changes. Buffer strip design requirements found in some western Forest Practices Act (FPA) regulations are also compared and related to findings in the scientific literature.« less

Analysis of a hybrid, unidirectional buffer strip laminate

NASA Technical Reports Server (NTRS)

Dharani, L. R.; Goree, J. G.

1983-01-01

A method of analysis capable of predicting accurately the fracture behavior of a unidirectional composite laminate containing symmetrically placed buffer strips is presented. As an example, for a damaged graphite/epoxy laminate, the results demonstrate the manner in which to select the most efficient combination of buffer strip properties necessary to inhibit crack growth. Ultimate failure of the laminate after crack arrest can occur under increasing load either by continued crack extension through the buffer strips or the crack can jump the buffer strips. For some typical hybrid materials it is found that a buffer strip spacing-to-width ratio of about four to one is the most efficient.

Analysis of a hybrid-undirectional buffer strip laminate

NASA Technical Reports Server (NTRS)

Dharani, L. R.; Goree, J. G.

1983-01-01

A method of analysis capable of predicting accurately the fracture behavior of a unidirectional composite laminate containing symmetrically placed buffer strips is presented. As an example, for a damaged graphite/epoxy laminate, the results demonstrate the manner in which to select the most efficient combination of buffer strip properties necessary to inhibit crack growth. Ultimate failure of the laminate after the arrest can occur under increasing load either by continued crack extension through the buffer strips or the crack can jump the buffer strips. For some typical hybrid materials it is found that a buffer strip spacing to width ratio of about four to one is the most efficient.

Effects of fatigue and environment on residual strengths of center-cracked graphite/epoxy buffer strip panels

NASA Technical Reports Server (NTRS)

Bigelow, Catherine A.

1989-01-01

The effects of fatigue, moisture conditioning, and heating on the residual tension strengths of center-cracked graphite/epoxy buffer strip panels were evaluated using specimens made with T300/5208 graphite epoxy in a 16-ply quasi-isotropic layup, with two different buffer strip materials, Kevlar-49 or S-glass. It was found that, for panels subjected to fatigue loading, the residual strengths were not significantly affected by the fatigue loading, the number of repetitions of the loading spectrum, or the maximum strain level. The moisture conditioning reduced the residual strengths of the S-glass buffer strip panels by 10 to 15 percent below the ambient results, but increased the residual strengths of the Kevlar-49 buffer strip panels slightly. For both buffer strip materials, the heat increased the residual strengths of the buffer strip panels slightly over the ambient results.

[Quantification study on the runoff and seepage distribution and N, P pollutants removal of the vegetated buffer strips].

PubMed

Wang, Min; Huang, Yu-Chi; Wu, Jian-Qiang

2010-11-01

By using the constructed buffer strips test base and the runoff hydrometric devices, a research on stagnant runoff and nitrogen (N), phosphorous (P) pollutants removal capacity of the vegetated buffer strips was conducted. The results show that the vegetated buffer strips might reduce the speed of runoff significantly and improve the hydraulic permeability of soil. The runoff water output time of 19 m buffer strips planted with Cynodon dactylon, Festuca arundinacea and Trifolium repens are 2.46, 1.72 and 2.03 times higher than the control (no vegetation) respectively; The seepage water quantity of three vegetation buffer strips are 3.01, 2.16 and 2.45 times higher than the control respectively as well. Total removal efficiency of the three buffer strips increase about 237%, 268% and 274% comparing with the control respectively. The N, P removal capacity of seepage is significantly higher than that of the runoff, the larger seepage water quantity will cause higher N, P total removal efficiency and removal loads of unit area. With different vegetated buffer strips, the TN, NH4(+) -N, TP removal ratio of seepage and runoff are 2.79, 2.02 and 2.83 respectively.

Imidacloprid sorption and transport in cropland, grass buffer and riparian buffer soils

USGS Publications Warehouse

Satkowski, Laura E.; Goyne, Keith W.; Anderson, Stephen H.; Lerch, Robert N.; Allen, Craig R.; Snow, Daniel D.

2018-01-01

An understanding of neonicotinoid sorption and transport in soil is critical for determining and mitigating environmental risk associated with the most widely used class of insecticides. The objective of this study was to evaluate mobility and transport of the neonicotinoid imidacloprid (ICD) in soils collected from cropland, grass vegetative buffer strip (VBS), and riparian VBS soils. Soils were collected at six randomly chosen sites within grids that encompassed all three land uses. Single-point equilibrium batch sorption experiments were conducted using radio-labeled (14C) ICD to determine solid–solution partition coefficients (Kd). Column experiments were conducted using soils collected from the three vegetation treatments at one site by packing soil into glass columns. Water flow was characterized by applying Br− as a nonreactive tracer. A single pulse of 14C-ICD was then applied, and ICD leaching was monitored for up to 45 d. Bromide and ICD breakthrough curves for each column were simulated using CXTFIT and HYDRUS-1D models. Sorption results indicated that ICD sorbs more strongly to riparian VBS (Kd = 22.6 L kg−1) than crop (Kd = 11.3 L kg−1) soils. Soil organic C was the strongest predictor of ICD sorption (p < 0.0001). The column transport study found mean peak concentrations of ICD at 5.83, 10.84, and 23.8 pore volumes for crop, grass VBS, and riparian VBS soils, respectively. HYDRUS-1D results indicated that the two-site, one-rate linear reversible model best described results of the breakthrough curves, indicating the complexity of ICD sorption and demonstrating its mobility in soil. Greater sorption and longer retention by the grass and riparian VBS soils than the cropland soil suggests that VBS may be a viable means to mitigate ICD loss from agroecosystems, thereby preventing ICD transport into surface water, groundwater, or drinking water resources.

Erosion rills offset the efficacy of vegetated buffer strips to mitigate pesticide exposure in surface waters.

PubMed

Stehle, Sebastian; Dabrowski, James Michael; Bangert, Uli; Schulz, Ralf

2016-03-01

Regulatory risk assessment considers vegetated buffer strips as effective risk mitigation measures for the reduction of runoff-related pesticide exposure of surface waters. However, apart from buffer strip widths, further characteristics such as vegetation density or the presence of erosion rills are generally neglected in the determination of buffer strip mitigation efficacies. This study conducted a field survey of fruit orchards (average slope 3.1-12.2%) of the Lourens River catchment, South Africa, which specifically focused on the characteristics and attributes of buffer strips separating orchard areas from tributary streams. In addition, in-stream and erosion rill water samples were collected during three runoff events and GIS-based modeling was employed to predict losses of pesticides associated with runoff. The results show that erosion rills are common in buffer strips (on average 13 to 24 m wide) of the tributaries (up to 6.5 erosion rills per km flow length) and that erosion rills represent concentrated entry pathways of pesticide runoff into the tributaries during rainfall events. Exposure modeling shows that measured pesticide surface water concentrations correlated significantly (R(2)=0.626; p<0.001) with runoff losses predicted by the modeling approach in which buffer strip width was set to zero at sites with erosion rills; in contrast, no relationship between predicted runoff losses and in-stream pesticide concentrations were detected in the modeling approach that neglected erosion rills and thus assumed efficient buffer strips. Overall, the results of our study show that erosion rills may substantially reduce buffer strip pesticide retention efficacies during runoff events and suggest that the capability of buffer strips as a risk mitigation tool for runoff is largely overestimated in current regulatory risk assessment procedures conducted for pesticide authorization. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of vegetated filter strips on transport and deposition rates of Escherichia coli in overland flow in the eastern escarpments of the Mau Forest, Njoro River Watershed, Kenya

PubMed Central

Onyando, J. O.; Moturi, W. N.; Muia, A. W.; Ombui, P.; Shivoga, W. A.; Roegner, A. F.

2016-01-01

The fate and transport of Escherichia coli (E. coli) in lotic waters through vegetated filter strips (VFSs) was evaluated in a field model pasture, utilizing VFSMOD Windows along with direct pathogen testing. This study assessed effects of VFS on transport and deposition rates of E. coli in lotic overland flow waters. The VFS measured 44 m long by 40 m wide, covering an area of 1584 m2 and land slope of 15 %. Cowpat was applied onto the model pasture and washed by overland flow into the VFS. The 4-methylumbelliferyl β-D-glucuronide substrate confirmed the identity of E. coli prior to cowpat application and after isolating them from soil using centrifugation and membrane filtration techniques. Napier grass root system recorded the highest recovery rates of E. coli at 99.9 % along the length of VFS III. This efficiency reduced significantly (p < 0.05; df = 29) to 95 % in Kikuyu grass and 75 % in Couch grass–Buffer grass. The data demonstrated similarity in transport of manure-borne E. coli and organic carbon (OC) through all the simulated VFS. These results indicated that OC could be used as a true natural tracer of manure-borne E. coli, a pollution indicator organism of lentic and lotic surface waters provided the OC release kinetics from cowpat were similar to that of E. coli kinetics. Thus, efficient filtering to reduce E. coli concentrations and load in overland flows requires managing combined grass species, agro-pastoral systems models and dispersed or preferential flows to enhance surface water quality standards. PMID:28393102

Prairie and turf buffer strips for controlling runoff from paved surfaces.

PubMed

Steinke, K; Stier, J C; Kussow, W R; Thompson, A

2007-01-01

Eutrophication of surface waters due to nonpoint source pollution from urban environments has raised awareness of the need to decrease runoff from roads and other impervious surfaces. These concerns have led to precautionary P application restrictions on turf and requirements for vegetative buffer strips. The impacts of two plant communities and three impervious/pervious surface ratios were assessed on runoff water quality and quantity. A mixed forb/grass prairie and a Kentucky bluegrass (Poa pratensis L.) blend were seeded and runoff was monitored and analyzed for total volume, total P, soluble P, soluble organic P, bioavailable P, total suspended solids, and total organic suspended solids. Mean annual runoff volumes, all types of mean annual P nutrient losses, and sediment loads were not significantly affected by treatments because over 80% of runoff occurred during frozen soil conditions. Total P losses from prairie and turf were similar, averaging 1.96 and 2.12 kg ha(-1) yr(-1), respectively. Vegetation appeared to be a likely contributor of nutrients, particularly from prairie during winter dormancy. When runoff occurred during non-frozen soil conditions turf allowed significantly (P < or = 0.10) lower runoff volumes compared with prairie vegetation and the 1:2 and 1:4 impervious/pervious surface ratios had less runoff than the 1:1 ratio (P < or = 0.05). In climates where the majority of runoff occurs during frozen ground conditions, vegetative buffers strips alone are unlikely to dramatically reduce runoff and nutrient loading into surface waters. Regardless of vegetation type or size, natural nutrient biogeochemical cycling will cause nutrient loss in surface runoff waters, and these values may represent baseline thresholds below which values cannot be obtained.

Analysis of a unidirectional, symmetric buffer strip laminate with damage

NASA Technical Reports Server (NTRS)

Dharani, L. R.; Goree, J. G.

1984-01-01

A method for predicting the fracture behavior of hybrid buffer strip laminates is presented in which the classical shear-lag model is used to represent the shear stress distribution between adjacent fibers. The method is demonstrated by applying it to a notched graphite/epoxy laminate, and the results show clearly the manner in which the most efficient combination of buffer strip properties can be selected in order to arrest the crack. The ultimate failure stress of the laminate is plotted vs the buffer strip width. It is shown that in the case of graphite-epoxy and S-glass epoxy laminates, the optimum buffer strip spacing to width ratio should be about four to one.

Modelling the effectiveness of grass buffer strips in managing muddy floods under a changing climate

NASA Astrophysics Data System (ADS)

Mullan, Donal; Vandaele, Karel; Boardman, John; Meneely, John; Crossley, Laura H.

2016-10-01

Muddy floods occur when rainfall generates runoff on agricultural land, detaching and transporting sediment into the surrounding natural and built environment. In the Belgian Loess Belt, muddy floods occur regularly and lead to considerable economic costs associated with damage to property and infrastructure. Mitigation measures designed to manage the problem have been tested in a pilot area within Flanders and were found to be cost-effective within three years. This study assesses whether these mitigation measures will remain effective under a changing climate. To test this, the Water Erosion Prediction Project (WEPP) model was used to examine muddy flooding diagnostics (precipitation, runoff, soil loss and sediment yield) for a case study hillslope in Flanders where grass buffer strips are currently used as a mitigation measure. The model was run for present day conditions and then under 33 future site-specific climate scenarios. These future scenarios were generated from three earth system models driven by four representative concentration pathways and downscaled using quantile mapping and the weather generator CLIGEN. Results reveal that under the majority of future scenarios, muddy flooding diagnostics are projected to increase, mostly as a consequence of large scale precipitation events rather than mean changes. The magnitude of muddy flood events for a given return period is also generally projected to increase. These findings indicate that present day mitigation measures may have a reduced capacity to manage muddy flooding given the changes imposed by a warming climate with an enhanced hydrological cycle. Revisions to the design of existing mitigation measures within existing policy frameworks are considered the most effective way to account for the impacts of climate change in future mitigation planning.

Fatigue of graphite/epoxy buffer strip panels with center cracks

NASA Technical Reports Server (NTRS)

Bigelow, C. A.

1985-01-01

The effects of fatigue loading on the behavior of graphite/epoxy panels with either S-Glass or Kevlar-49 buffer strips is studied. Buffer strip panels are fatigued and tested in tension to measure their residual strength with crack-like damage. Panels are made with 45/0/-45/90 sub 2s layup with either S-Glass or Kevlar-49 buffer strip material. The buffer strips are parallel to the loading direction and made by replacing narrow strips of the 0-degree graphite plies with strips of either 0-degree S-Glass/epoxy or Kevlar-49/epoxy on a one-for-one basis. The panels are subjected to a fatigue loading spectrum MINITWIST, the shortened version of the standardized load program for the wing lower surface of a transport aircraft. Two levels of maximum strain are used in the spectrum with three durations of the fatigue spectrum. One group of panels is preloaded prior to the application of the fatigue cycling. The preload consists of statistically loading the spectrum in tension until the crack-tip damage zone reaches the ajacent buffer strips. After fatigue loading, all specimens are statistically loaded in tension to failure to determine their residual strengths.

Attenuation of runoff and chemical loads in grass filter strips at two cattle feedlots, Minnesota, 1995-98

USGS Publications Warehouse

Komor, Stephen Charles; Hansen, Donald S.

2003-01-01

Attenuation of cattle feedlot runoff in two grass-covered filter strips in Minnesota was estimated by measuring chemical loads into and out of the strips. Filter strips of the Bock and Sanborn sites were 60-m long and 20-m wide and received runoff from cattle feedlots that supported 35 and 225 cattle, respectively. Feedlot and filter-strip runoff were measured using flumes with stage sensors. Water samples were collected using automated samplers. Attenuation values were calculated from four storm-runoff events. Ground water sampled beneath and outside the filter strips indicated some infiltration losses of sulfate, chloride, and nitrogen at the Bock site where soil permeability was greater than at the Sanborn site. Chemical constituents in filter-strip runoff, and their corresponding ranges of attenuation were as follows: chemical oxygen demand, 30–81 percent; dissolved chloride, 6–79 percent; dissolved sulfate, -3–82 percent; dissolved ammonia nitrogen, 33–80 percent; suspended ammonia plus organic nitrogen, 29–85 percent; dissolved organic nitrogen, 14–75 percent; suspended phosphorus, 24–82 percent; dissolved phosphorus, 14–72 percent; and fecal coliform bacteria, 18–79 percent. The ranges seem to be affected by barriers of direct contact of the runoff water with the soil. This varies seasonally by coverage of the soil by ice in winter and vegetation in summer months. Greater attenuation values occurred in October and May when mats of wilted, flat-lying grass covered the filter strips; attenuation values were less during the summer when tall growing grass covered the filter strips.

Effects of grazing management and buffer strips on metal runoff from pastures fertilized with poultry litter

USDA-ARS?s Scientific Manuscript database

Metal runoff from fields fertilized with poultry litter may pose a threat to aquatic systems. Buffer strips have been added to fields to reduce nutrients and solids runoff. However, scant information exists on the effects of buffer strips combined with grazing management strategies on metal runoff f...

Effects of AN Alfalfa (medicago Sativa) Buffer Strip on Leached δ15NNITRATE Values: Implications for Management of Hydrologic N Losses

NASA Astrophysics Data System (ADS)

Kelley, C. J.; Keller, C. K.; Smith, J. L.; Evans, R. D.; Harlow, B.

2011-12-01

Buffer strips are commonly used to decrease agricultural runoff with the objective of limiting sediment and agrochemicals fluxes to surface waters. The objective of this study was to determine the effects of an alfalfa buffer strip on the magnitude and source(s) of leached nitrate from a dryland agricultural field. Previous research at the Cook Agronomy Farm has inferred two sources of nitrate in tile drain discharge, a high-discharge-season (January through May) synthetic fertilizer source, and a low-discharge-season (June through December) soil organic nitrogen source. This study examines how a change in management strategy and crop species alters the low discharge season nitrate source. In the spring of 2006 an alfalfa buffer strip approximately 20 m wide was planted running approximately north-south in the lowland portion of a 12 ha tile-drained field bordering a ditch that drains into Missouri Flat Creek. Three-year (2003 through 2005) average NO3--N flux prior to the planting of the alfalfa buffer strip was ~0.40 kg ha-1 year-1. After planting, the three-year (2006 through 2008) average NO3--N flux was ~0.38 kg ha-1 year-1. The lack of evident buffer-strip influence on the fluxes may be due in part to the large variation in precipitation amounts and timing that control water flows through the system. Three-year average δ15Nnitrate values for the tile drain pre and post planting of the alfalfa buffer strip were 6.9 ± 1.1 % and 4.2 ± 0.9 % respectively. We hypothesize that the significant difference indicates that the alfalfa strip affects the source of leached nitrate. Before planting the alfalfa buffer strip, the interpreted source of nitrate was mineralization of soil organic nitrogen from non-N2 fixing crops (spring and summer wheat varieties). After planting the alfalfa buffer strip, the source of nitrate was interpreted to be a mixture of mineralized soil organic nitrogen from N2 fixing alfalfa and non-N2 fixing crops. Further work is needed to test alternative explanations for the observed isotopic shift. This study suggests that the effects of leguminous buffer strips on nutrient fluxes are not simple, and may depend on combinations of hydrologic and pedo-geologic factors.

Dynamics and mitigation of six pesticides in a "Wet" forest buffer zone.

PubMed

Passeport, Elodie; Richard, Benjamin; Chaumont, Cédric; Margoum, Christelle; Liger, Lucie; Gril, Jean-Joël; Tournebize, Julien

2014-04-01

Pesticide pollution is one of the main current threats on water quality. This paper presents the potential and functioning principles of a "Wet" forest buffer zone for reducing concentrations and loads of glyphosate, isoproturon, metazachlor, azoxystrobin, epoxiconazole, and cyproconazole. A tracer injection experiment was conducted in the field in a forest buffer zone at Bray (France). A fine time-scale sampling enabled to illustrate that interactions between pesticides and forest buffer substrates (soil and organic-rich litter layer), had a retarding effect on molecule transfer. Low concentrations were observed for all pesticides at the forest buffer outlet thus demonstrating the efficiency of "Wet" forest buffer zone for pesticide dissipation. Pesticide masses injected in the forest buffer inlet directly determined concentration peaks observed at the outlet. Rapid and partially reversible adsorption was likely the major process affecting pesticide transfer for short retention times (a few hours to a few days). Remobilization of metazachlor, isoproturon, desmethylisoproturon, and AMPA was observed when non-contaminated water flows passed through the forest buffer. Our data suggest that pesticide sorption properties alone could not explain the complex reaction mechanisms that affected pesticide transfer in the forest buffer. Nevertheless, the thick layer of organic matter litter on the top of the forest soil was a key parameter, which enhanced partially reversible sorption of pesticide, thus retarded their transfer, decreased concentration peaks, and likely increased degradation of the pesticides. Consequently, to limit pesticide pollution transported by surface water, the use of already existing forest areas as buffer zones should be equally considered as the most commonly implemented grass buffer strips.

Buffering the buffer

Treesearch

Leslie M. Reid; Sue Hilton

1998-01-01

Riparian buffer strips are a widely accepted tool for helping to sustain aquatic ecosystems and to protect downstream resources and values in forested areas, but controversy persists over how wide a buffer strip is necessary. The physical integrity of stream channels is expected to be sustained if the characteristics and rates of tree fall along buffered reaches are...

Impact of buffer type on streamside nutrient concentrations in Upper Big Walnut Creek, Ohio

USDA-ARS?s Scientific Manuscript database

The identification and assessment of conservation practices continues to be important for the protection of natural resources. Buffers, also referred to as filter strips, buffer strips, riparian buffers, or vegetative filters are one of the most common types of conservation practice installed in the...

The combined effect of glass buffer strips and stitching on the damage tolerance of composites

NASA Technical Reports Server (NTRS)

Kullerd, Susan M.

1993-01-01

Recent research has demonstrated that through-the-thickness stitching provides major improvements in the damage tolerance of composite laminates loaded in compression. However, the brittle nature of polymer matrix composites makes them susceptible to damage propagation, requiring special material applications and designs to limit damage growth. Glass buffer strips, embedded within laminates, have shown the potential for improving the damage tolerance of unstitched composite laminates loaded in tension. The glass buffer strips, less stiff than the surrounding carbon fibers, arrest crack growth in composites under tensile loads. The present study investigates the damage tolerance characteristics of laminates that contain both stitching and glass buffer strips.

Designing bioenergy crop buffers to mitigate nitrous oxide emissions and water quality impacts from agriculture

NASA Astrophysics Data System (ADS)

Gopalakrishnan, G.; Negri, C. M.

2010-12-01

There is a strong societal need to evaluate and understand the environmental aspects of bioenergy production, especially due to the significant increases in production mandated by many countries, including the United States. Bioenergy is a land-based renewable resource and increases in production are likely to result in large-scale conversion of land from current uses to bioenergy crop production; potentially causing increases in the prices of food, land and agricultural commodities as well as disruption of ecosystems. Current research on the environmental sustainability of bioenergy has largely focused on the potential of bioenergy crops to sequester carbon and mitigate greenhouse gas (GHG) emissions and possible impacts on water quality and quantity. A key assumption in these studies is that bioenergy crops will be grown in a manner similar to current agricultural crops such as corn and hence would affect the environment similarly. This study presents a systems approach where the agricultural, energy and environmental sectors are considered as components of a single system, and bioenergy crops are used to design multi-functional agricultural landscapes that meet society’s requirements for food, energy and environmental protection. We evaluate the production of bioenergy crop buffers on marginal land and using degraded water and discuss the potential for growing cellulosic bioenergy crops such as miscanthus and switchgrass in optimized systems such that (1) marginal land is brought into productive use; (2) impaired water is used to boost yields (3); clean freshwater is left for other uses that require higher water quality; and (4) feedstock diversification is achieved that helps ecological sustainability, biodiversity, and economic opportunities for farmers. The process-based biogeochemical model DNDC was used to simulate crop yield, nitrous oxide production and nitrate concentrations in groundwater when bioenergy crops were grown in buffer strips adjacent to corn fields. The bioenergy crops used in this study were miscanthus, switchgrass and native prairie grasses. Results indicated that growing bioenergy crops in buffer strips mitigated nutrient runoff and reduced nitrate concentrations in groundwater to below EPA’s mandated drinking water limit (10 mg/l). Additionally, nitrous oxide emissions in these systems were reduced by 50-90% when compared to corn fields without the bioenergy buffer strips. While all the bioenergy crop buffers had significant positive environmental benefits, switchgrass performed the best with respect to minimizing nutrient runoff and nitrous oxide emissions. The findings of this research have important implications with respect to land management for agriculture and bioenergy.

Establishing native warm season grasses on Eastern Kentucky strip mines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnes, T.G.; Larkin, J.L.; Arnett, M.B.

1998-12-31

The authors evaluated various methods of establishing native warm season grasses on two reclaimed Eastern Kentucky mines from 1994--1997. Most current reclamation practices incorporate the use of tall fescue (Festuca arundinacea) and other cool-season grasses/legumes that provide little wildlife habitats. The use of native warm season grasses will likely improve wildlife habitat on reclaimed strip mines. Objectives of this study were to compare the feasibility of establishing these grasses during fall, winter, or spring using a native rangeland seeder or hydroseeding; a fertilizer application at planting; or cold-moist stratification prior to hydroseeding. Vegetative cover, bare ground, species richness, and biomassmore » samples were collected at the end of each growing season. Native warm season grass plantings had higher plant species richness compared to cool-season reclamation mixtures. There was no difference in establishment of native warm season grasses as a result of fertilization or seeding technique. Winter native warm season grass plantings were failures and cold-moist stratification did not increase plant establishment during any season. As a result of a drought during 1997, both cool-season and warm season plantings were failures. Cool-season reclamation mixtures had significantly more vegetative cover and biomass compared to native warm season grass mixtures and the native warm season grass plantings did not meet vegetative cover requirements for bond release. Forbs and legumes that established well included pale purple coneflower (Echinacea pallida), lance-leaf coreopsis (Coreopsis lanceolata), round-headed lespedeza (Lespedeza capitata), partridge pea (Cassia fasiculata), black-eyed susan (Rudbeckia hirta), butterfly milkweed (Asclepias tuberosa), and bergamot (Monarda fistulosa). Results from two demonstration plots next to research plots indicate it is possible to establish native warm season grasses on Eastern Kentucky strip mines for wildlife habitat.« less

Effects of moisture, elevated temperature, and fatigue loading on the behavior of graphite/epoxy buffer strip panels with center cracks

NASA Technical Reports Server (NTRS)

Bigelow, C. A.

1988-01-01

The effects of fatigue loading combined with moisture and heat on the behavior of graphite epoxy panels with either Kevlar-49 or S-glass buffer strips were studied. Buffer strip panels, that had a slit in the center to represent damage, were moisture conditioned or heated, fatigue loaded, and then tested in tension to measure their residual strength. The buffer strips were parallel to the loading direction and were made by replacing narrow strips of the 0 deg graphite plies with Kevlar-49 epoxy or S-glass epoxy on a 1-for-1 basis. The panels were subjected to a fatigue loading spectrum. One group of panels was preconditioned by soaking in 60 C water to produce a 1 percent weight gain then tested at room temperature. One group was heated to 82 C during the fatigue loading. Another group was moisture conditioned and then tested at 82 C. The residual strengths of the buffer panels were not highly affected by the fatigue loading, the number of repetitions of the loading spectrum, or the maximum strain level. The moisture conditioning reduced the residual strengths of the S-glass buffer strip panel by 10 to 15 percent below the ambient results. The moisture conditioning did not have a large effect on the Kevlar-49 panels.

Effect of buffer strips and soil texture on runoff losses of flufenacet and isoxaflutole from maize fields.

PubMed

Milan, Marco; Ferrero, Aldo; Letey, Marilisa; De Palo, Fernando; Vidotto, Francesco

2013-01-01

The influence of buffer strips and soil texture on runoff of flufenacet and isoxaflutole was studied for two years in Northern Italy. The efficacy of buffer strips was evaluated on six plots characterized by different soil textures; two plots had Riva soil (18.6% sand, 63.1% silt, 18.3% clay) while the remaining four plots had Tetto Frati (TF) soil (37.1% sand, 57% silt, 5.9% clay). Additionally, the width of the buffer strips, constituted of spontaneous vegetation grown after crop sowing, was also compared for their ability to abate runoff waters. Chemical residues in water following runoff events were investigated, as well as their dissipation in the soil. After the first runoff events, concentrations of herbicides in water samples collected from Riva plots were as much as four times lower in waters from TF plots. On average of two growing seasons, the field half-life of flufenacet in the upper soil layer (5 cm) ranged between 8.1 and 12.8 days in Riva soil, 8.5 and 9.3 days in TF soil. Isoxaflutole field half-life was less than 1 day. The buffer strip was very affective by the uniformity of the vegetative cover, particularly, at the beginning of the season. In TF plots, concentration differences were generally due to the presence or absence of the buffer strip, regardless of its width.

Buffers and vegetative filter strips

Treesearch

Matthew J. Helmers; Thomas M. Isenhart; Michael G. Dosskey; Seth M. Dabney

2008-01-01

This chapter describes the use of buffers and vegetative filter strips relative to water quality. In particular, we primarily discuss the herbaceous components of the following NRCS Conservation Practice Standards.

Grass buffers for playas in agricultural landscapes: A literature synthesis

USGS Publications Warehouse

Melcher, Cynthia P.; Skagen, Susan K.

2005-01-01

Future research should entail multiple-scale approaches at regional, wetland-complex, and individual watershed scales. Information needs include direct measures of buffer effectiveness in ‘real-world’ systems, refinement and field tests of buffer-effectiveness models, how buffers may affect floral and faunal communities of playas, and basic ecological information on playa function and playa wildlife ecology. Understanding how wildlife communities respond to patch size and habitat fragmentation is crucial for addressing questions regarding habitat quality of grass buffers in playa systems.

Composition and design of vegetative filter strips instrumental in improving water quality by mass reduction of suspended sediment, nutrients and Escherichia coli in overland flows in eastern escarpment of Mau Forest, Njoro River Watershed, Kenya

PubMed Central

Olilo, C. O.; Onyando, J. O.; Moturi, W. N.; Muia, A. W.; Roegner, Amber F.; Ogari, Z.; Ombui, P. N.; Shivoga, W. A.

2016-01-01

This study assessed the effect of vegetative filter strip (VFS) in removal of suspended sediment (SS), total nitrogen, total phosphorus and Escherichia coli (E. coli) in overland flow to improve receiving water quality standards. Four and half kilograms of cowpat manure was applied to the model pasture 14 m beyond the edge of vegetated filter strip (VFS) comprising 10-m Napier grass draining into 20-m Kikuyu grass (VFS II), 10-m Kikuyu grass draining into 20-m Napier grass (VFS III) and native grass mixture of Couch–Buffel (VFS I-control). Overland flow water samples were collected from the sites at positions 0, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25 and 30 m along the length of VFSs. E. coli removal by Napier grass VFS was on the order of log unit, which provided an important level of protection and reduced surface-flow concentrations of E. coli to below the 200 (CFU 100 mL−1) recommended water quality standards, but not for nutrients and SS. The Napier grass showed highest efficiency (99.6 %), thus outperforming both Kikuyu grass (85.8 %) and Couch–Buffel grasses VFS (67.9 ± 4.2 %) in removing E. coli from overland flow. The low-level efficiency of native Couch–Buffel grasses in reducing E. coli in overland flow was because of preferential flow. Composition and design of VFS was instrumental and could be applied with a high potential of contracting the uncertainty in improving water quality standards through mass reduction of SS, nutrients and E. coli load in watersheds. PMID:28133624

Purification effect of two typical water source vegetation buffer zones on land-sourced pollutants

NASA Astrophysics Data System (ADS)

Li, Gang

2017-03-01

Two vegetation buffer zones (tree-shrub-grass pattern and tree-grass pattern) were selected as test objects around Siming reservoir in Yuyao City of China. The effect of the storm runoff intensity (low and high intensity) and the buffer zone width (1 m, 3 m, 5 m, 7 m, 9 m, 12 m, 16 m) on pollutants (suspended solids, ammonium nitrogen and total phosphorus) was studied by the artificial simulation runoff. The results showed that with the increase of the width of buffer zone, the pollutant concentration was decreased. The purification effect of the two buffer zones on suspended solids and total phosphorus was basically stable at 52-55% and 34-37%, respectively. But the purification effect on ammonium nitrogen was the tree-shrub-grass pattern (69.7%) significantly better than that of tree-grass pattern (52.1%). The purification rate at the low runoff intensity was 1.8-2.0 times that at the high runoff intensity. The relationship between the purification rate and buffer zone width can be expressed by the natural logarithm equation, and the model adjustment coefficient was greater than 0.92.

The impact of buffer strips and stream-side grazing on small mammals in southwestern Wisconsin

USGS Publications Warehouse

Chapman, Erik W.; Ribic, C.A.

2002-01-01

The practice of continuously grazing cattle along streams has caused extensive degradation of riparian habitats. Buffer strips and managed intensive rotational grazing (MIRG) have been proposed to protect and restore stream ecosystems in Wisconsin. However, the ecological implications of a switch from traditional livestock management to MIRG or buffer strip establishment have not been investigated. Differences in small mammal communities associated with riparian areas on continuously grazed and MIRG pastures, as well as vegetative buffer strips adjacent to row crops, were investigated in southwestern Wisconsin during May-September 1997 and 1998. More species (mean of 6-7) were found on the buffer sites than on the pasture sites (mean of 2-5). Total small mammal abundance on buffer sites was greater than on the pastures as well: there were 3-5 times as many animals on the buffer sites compared to the pasture sites, depending on year. There were no differences in species richness or total abundance between MIRG and continuously grazed pastures in either year. Total small mammal abundance was greater near the stream than away from the stream, regardless of farm management practice but there were no differences in species richness. Buffer strips appear to support a particularly rich and abundant small mammal community. Although results did not detect a difference in small mammal use between pasture types, farm-wide implications of a conversion from continuous to MIRG styles of grazing may benefit small mammals indirectly by causing an increase in the prevalence of pasture in the agricultural landscape.

Effects of Grazing Management and Buffer Strips on Metal Runoff from Pastures Fertilized with Poultry Litter.

PubMed

Pilon, C; Moore, P A; Pote, D H; Martin, J W; DeLaune, P B

2017-03-01

Metal runoff from fields fertilized with poultry litter may pose a threat to aquatic systems. Buffer strips located adjacent to fields may reduce nutrients and solids in runoff. However, scant information exists on the long-term effects of buffer strips combined with grazing management on metal runoff from pastures. The objective of this study was to assess the 12-yr impact of grazing management and buffer strips on metal runoff from pastures receiving poultry litter. The research was conducted using 15 watersheds (25 m wide and 57 m long) with five treatments: hayed (H), continuously grazed (CG), rotationally grazed (R), rotationally grazed with a buffer strip (RB), and rotationally grazed with a fenced riparian buffer strip (RBR). Poultry litter was applied annually in spring at 5.6 Mg ha. Runoff samples were collected after every rainfall event. Aluminum (Al) and iron (Fe) concentrations were strongly and positively correlated with total suspended solids, indicating soil erosion was the primary source. Soluble Al and Fe were not related to total Al and Fe. However, there was a strong positive correlation between soluble and total copper (Cu) concentrations. The majority of total Cu and zinc was in water-soluble form. The CG treatment had the highest metal concentrations and loads of all treatments. The RBR and H treatments resulted in lower concentrations of total Al, Cu, Fe, potassium, manganese, and total organic carbon in the runoff. Rotational grazing with a fenced riparian buffer and converting pastures to hayfields appear to be effective management systems for decreasing concentrations and loads of metals in surface runoff from pastures fertilized with poultry litter. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Vegetative buffer strips for reducing herbicide transport in runoff: effects of buffer width, vegetation, and season

USDA-ARS?s Scientific Manuscript database

The effect of vegetative buffer strip (VBS) width, vegetation, and season of the year on herbicide transport in runoff has not been well documented for runoff prone soils. A multi-year replicated plot-scale study was conducted on an eroded claypan soil with the following objectives: 1) assess the ef...

Water body and riparian buffer strip characteristics in a vineyard area to support aquatic pesticide exposure assessment.

PubMed

Ohliger, Renja; Schulz, Ralf

2010-10-15

The implementation of a geodata-based probabilistic pesticide exposure assessment for surface waters in Germany offers the opportunity to base the exposure estimation on more differentiated assumptions including detailed landscape characteristics. Since these characteristics can only be estimated using field surveys, water body width and depth, hydrology, riparian buffer strip width, ground vegetation cover, existence of concentrated flow paths, and riparian vegetation were characterised at 104 water body segments in the vineyard region Palatinate (south-west Germany). Water body segments classified as permanent (n=43) had median values of water body width and depth of 0.9m and 0.06m, respectively, and the determined median width:depth ratio was 15. Thus, the deterministic water body model (width=1m; depth=0.3m) assumed in regulatory exposure assessment seems unsuitable for small water bodies in the study area. Only 25% of investigated buffer strips had a dense vegetation cover (>70%) and allow a laminar sheet flow as required to include them as an effective pesticide runoff reduction landscape characteristic. At 77 buffer strips, bordering field paths and erosion rills leading into the water body were present, concentrating pesticide runoff and consequently decreasing buffer strip efficiency. The vegetation type shrubbery (height>1.5m) was present at 57 (29%) investigated riparian buffer strips. According to their median optical vegetation density of 75%, shrubberies may provide a spray drift reduction of 72±29%. Implementing detailed knowledge in an overall assessment revealed that exposure via drift might be 2.4 and via runoff up to 1.6 fold higher than assumed by the deterministic approach. Furthermore, considering vegetated buffer strips only by their width leads to an underestimation of exposure by a factor of as much as four. Our data highlight that the deterministic model assumptions neither represent worst-case nor median values and therefore cannot simply be adopted in a probabilistic approach. Copyright © 2010 Elsevier B.V. All rights reserved.

Method for manufacturing electrical contacts for a thin-film semiconductor device

DOEpatents

Carlson, David E.; Dickson, Charles R.; D'Aiello, Robert V.

1988-11-08

A method of fabricating spaced-apart back contacts on a thin film of semiconductor material by forming strips of buffer material on top of the semiconductor material in locations corresponding to the desired dividing lines between back contacts, forming a film of metal substantially covering the semiconductor material and buffer strips, and scribing portions of the metal film overlying the buffer strips with a laser without contacting the underlying semiconductor material to separate the metal layer into a plurality of back contacts. The buffer material serves to protect the underlying semiconductor material from being damaged during the laser scribing. Back contacts and multi-cell photovoltaic modules incorporating such back contacts also are disclosed.

Electrical contacts for a thin-film semiconductor device

DOEpatents

Carlson, David E.; Dickson, Charles R.; D'Aiello, Robert V.

1989-08-08

A method of fabricating spaced-apart back contacts on a thin film of semiconductor material by forming strips of buffer material on top of the semiconductor material in locations corresponding to the desired dividing lines between back contacts, forming a film of metal substantially covering the semiconductor material and buffer strips, and scribing portions of the metal film overlying the buffer strips with a laser without contacting the underlying semiconductor material to separate the metal layer into a plurality of back contacts. The buffer material serves to protect the underlying semiconductor material from being damaged during the laser scribing. Back contacts and multi-cell photovoltaic modules incorporating such back contacts also are disclosed.

Pollution Swapping in Agricultural Systems: deciding between mitigation measures with conflicting outcomes

NASA Astrophysics Data System (ADS)

Quinton, John; Stevens, Carly

2010-05-01

Pollution swapping occurs when a mitigation option introduced to reduce one pollutant results in an increase in a different pollutant. Although the concept of pollution swapping is widely understood it has received little attention in research and policy design. This study investigated diffuse pollution mitigation options applied in combinable crop systems. They are: cover crops, residue management, no-tillage, riparian buffer zones, contour grass strips and constructed wetlands. A wide range of water and atmospheric pollutants were considered, including nitrogen, phosphorus, carbon and sulphur. It is clear from this investigation that there is no single mitigation option that will reduce all pollutants and in this poster we consider how choices may be made between mitigation measures which may have a positive effect on one pollutant but a negative effect on another.

Preliminary investigation of crack arrest in composite laminates containing buffer strips

NASA Technical Reports Server (NTRS)

Goree, J. G.

1978-01-01

The mechanical properties of some hybrid buffer strip laminates and the crack arrest potential of laminates containing buffer strips were determined. The hybrid laminates consisted of graphite with either S-glass, E-glass, or Kevlar. Unnotched tensile coupons and center-cracked fracture coupons were tested. Elastic properties, complete stress/strain curves, and critical stress intensity values are given. The measured elastic properties compare well with those calculated by classical lamination theory for laminates with linear stress/strain behavior. The glass hybrids had more delamination and higher fracture toughness than the all-graphite or the Kevlar hybrid.

Impact of cornstalk buffer strip on hillslope soil erosion and its hydrodynamic understanding

USDA-ARS?s Scientific Manuscript database

Soil erosion is still a serious concern on the Loess Plateau despite extensive soil conservation measures. Cornstalk buffer strip is not well utilized on the Loess Plateau, and there is little information on the hydrodynamic understanding of this soil erosion control practice. A simulated rainfall e...

Woven graphite epoxy composite test specimens with glass buffer strips

NASA Technical Reports Server (NTRS)

Bonnar, G. R.; Palmer, R. J.

1982-01-01

Woven unidirectional graphite cloth with bands of fiberglass replacing the graphite in discrete lengthwise locations was impregnated with epoxy resin and used to fabricate a series of composite tensile and shear specimens. The finished panels, with the fiberglass buffer strips, were tested. Details of the fabrication process are reported.

Effects of buffer strips and grazing management on soil loss from pastures

USDA-ARS?s Scientific Manuscript database

Intensive grazing pressure can cause soil erosion from pastures causing increased sediment loading to aquatic systems. The objectives of this work were to determine the long-term effects of grazing management and buffer strips on soil erosion from pastures fertilized with broiler litter. Field stud...

Responses to riparian restoration in the Spring Creek watershed, Central Pennsylvania

USGS Publications Warehouse

Carline, R.F.; Walsh, M.C.

2007-01-01

Riparian treatments, consisting of 3- to 4-m buffer strips, stream bank stabilization, and rock-lined stream crossings, were installed in two streams with livestock grazing to reduce sediment loading and stream bank erosion. Cedar Run and Slab Cabin Run, the treatment streams, and Spring Creek, an adjacent reference stream without riparian grazing, were monitored prior to (1991-1992) and 3-5 years after (2001-2003) riparian buffer installation to assess channel morphology, stream substrate composition, suspended sediments, and macroinvertebrate communities. Few changes were found in channel widths and depths, but channel-structuring flow events were rare in the drought period after restoration. Stream bank vegetation increased from 50% or less to 100% in nearly all formerly grazed riparian buffers. The proportion of fine sediments in stream substrates decreased in Cedar Run but not in Slab Cabin Run. After riparian treatments, suspended sediments during base flow and storm flow decreased 47-87% in both streams. Macroinvertebrate diversity did not improve after restoration in either treated stream. Relative to Spring Creek, macroinvertebrate densities increased in both treated streams by the end of the posttreatment sampling period. Despite drought conditions that may have altered physical and biological effects of riparian treatments, goals of the riparian restoration to minimize erosion and sedimentation were met. A relatively narrow grass buffer along 2.4 km of each stream was effective in improving water quality, stream substrates, and some biological metrics. ?? 2007 Society for Ecological Restoration International.

Streambank Erosion from Grazed Pastures, Grass Filters and Forest Buffers Over a Six-Year Period

USDA-ARS?s Scientific Manuscript database

In agricultural landscapes, streambank erosion, as a source of non-point water pollution, is one of the major contributors to stream habitat degradation. Streambank erosion rates from riparian forest buffers, grass filters and grazed pastures (stocking rates ranged from 0.23 to 1.15 cow-days ha-1 m-...

Riparian buffer strips as a multifunctional management tool in agricultural landscapes: introduction.

PubMed

Stutter, Marc I; Chardon, Wim J; Kronvang, Brian

2012-01-01

Catchment riparian areas are considered key zones to target mitigation measures aimed at interrupting the movement of diffuse substances from agricultural land to surface waters. Hence, unfertilized buffer strips have become a widely studied and implemented "edge of field" mitigation measure assumed to provide an effective physical barrier against nitrogen (N), phosphorus (P), and sediment transfer. To ease the legislative process, these buffers are often narrow mandatory strips along streams and rivers, across different riparian soil water conditions, between bordering land uses of differing pollution burdens, and without prescribed buffer management. It would be easy to criticize such regulation for not providing the opportunity for riparian ecosystems to maximize their provision for a wider range of ecosystem goods and services. The scientific basis for judging the best course of action in designing and placing buffers to enhance their multifunctionality has slowly increased over the last five years. This collection of papers aims to add to this body of knowledge by giving examples of studies related to riparian buffer management and assessment throughout Europe. This introductory paper summarizes discussion sessions and 13 selected papers from a workshop held in Ballater, UK, highlighting research on riparian buffers brought together under the EU COST Action 869 knowledge exchange program. The themes addressed are (i) evidence of catchment- to national-scale effectiveness, (ii) ecological functioning linking terrestrial and aquatic habitats, (iii) modeling tools for assessment of effectiveness and costs, and (iv) process understanding enabling management and manipulation to enhance pollutant retention in buffers. The combined understanding led us to consider four principle key questions to challenge buffer strip research and policy. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Long-term effects of grazing management and buffer strips on soil erosion from pastures

USDA-ARS?s Scientific Manuscript database

High grazing pressure can lead to soil erosion in pastures by compacting soil and increasing runoff and sediment delivery to waterways. Limited information exists on the effects of grazing management and best management practices (BMPs), such as buffer strips, on soil erosion from pastures. The obje...

Fracture and crack growth in orthotropic laminates. Part 1: Analysis of a hybrid, unidirectional laminate with damage

NASA Technical Reports Server (NTRS)

Goree, J. G.

1982-01-01

The fracture behavior of unifirectional hybrid (buffer strip) composite laminates is studied. Three particular solutions are discussed: (1) broken fibers in a unidirectional half plane; (2) adjoined half planes of different fiber and matrix properties and (3) the solution of two half planes bounding a third distinct region of finite width. This finite width region represents a buffer strip and the potential of this strip to arrest a crack that originates in one of the half planes is investigated. The analysis is based on a materials modeling approach using the classical shear lag assumption to described the stress transfer between fibers. Explicit fiber and matrix properties of the three regions are retained and changes in the laminate behavior as a function of the relative material properties, buffer strip width and initial crack length are discussed.

Evaluation of a mechanistic algorithm to calculate the influence of a shallow water table on hydrology sediment and pesticide transport through vegetative filter strips

NASA Astrophysics Data System (ADS)

Lauvernet, C.; Munoz-Carpena, R.; Carluer, N.

2012-04-01

Natural or introduced areas of vegetation, also known as vegetative filter strips (VFS), are a common environmental control practice to protect surface water bodies from human influence. In Europe, VFS are placed along the water network to protect from agrochemical drift during applications, in addition to runoff control. Their bottomland placement next to the streams often implies the presence of a seasonal shallow water table which can have a profound impact on the efficiency of the buffer zone (Lacas et al. 2005). A physically-based algorithm describing ponded infiltration into soils bounded by a water table, proposed by Salvucci and Enthekabi (1995), was further developed to simulate VFS dynamics by making it explicit in time, account for unsteady rainfall conditions, and by coupling to a numerical overland flow and transport model (VFSMOD) (Munoz-Carpena et al., submitted). In this study, we evaluate the importance of the presence of a shallow water table on filter efficiency (reductions in runoff, sediment and pesticide mass), in the context of all other input factors used to describe the system. Global sensitivity analysis (GSA) was used to rank the important input factors and the presence of interactions, as well as the contribution of the important factors to the output variance. GSA of VSFMOD modified for shallow water table was implemented on 2 sites selected in France because they represent different agro-pedo-climatic conditions for which we can compare the role of the factors influencing the performance of grassed buffer strips for surface runoff, sediment and pesticide removal. The first site at Morcille watershed in the Beaujolais wineyard (Rhône-Alpes) contains a very permeable sandy-clay with water table depth varying with the season (very deep in summer and shallow in winter), with a high slope (20 to 30%), and subject to strong seasonal storms (semi-continental, Mediterranean climate). The second site at La Jailliere (Loire-Atlantique, ARVALIS-Institut du Végétal, mainly wheat and maize) is a poorly permeable medium loamy over clay soil, with possible local shallow water tables, slopes around 3% and mild and rainy winter while summer is cool and wet (temperate, oceanic climate). GSA allowed us to interpret the results from the multivariate Monte-Carlo uncertainty analysis and gain insights on the management and placement of the buffer systems.

Buffer$--An Economic Analysis Tool

Treesearch

Gary Bentrup

2007-01-01

Buffer$ is an economic spreadsheet tool for analyzing the cost-benefits of conservation buffers by resource professionals. Conservation buffers are linear strips of vegetation managed for multiple landowner and societal objectives. The Microsoft Excel based spreadsheet can calculate potential income derived from a buffer, including income from cost-share/incentive...

Microbial community diversity in agroforestry and grass vegetative filter strips

USDA-ARS?s Scientific Manuscript database

Vegetative filter strips (VFS) have long been promoted as a soil conservation practice that yields many additional environmental benefits. Most previous studies have focused primarily on the role of vegetation and/or soil physical properties in these ecosystem services. Few studies have investigated...

Low Herbicide Concentration Found in Streamflow After a Grass Cover is Killed

Treesearch

J.E. Douglass; D.R. Cochrane; G.W. Bailey; J.I. Teasley; D.W. Hill

1969-01-01

The grass cover on a steep Appalachian watershed was sprayed in 1966 with herbicides-first with atrazine and paraquat and later with atrazine and 2,4-D. Although grass growing in the stream channel was sprayed during the first treatment, atrazine and paraquat levels in water samples were low. For the second treatment, a 10-foot strip on either side of the channel was...

Establishing conservation buffers using precision information

Treesearch

Mike G. Dosskey; Dean E. Eisenhauer; Matthew J. Helmers

2005-01-01

Conservation buffers, such as filter strips and riparian forest buffers, are widely prescribed to improve and protect water quality in agricultural landscapes. These buffers intercept field runoff and retain some of its pollutant load before it reaches a waterway. A buffer typically is designed to have uniform width along a field margin and to intercept runoff that...

Riparian buffer zones on selected rivers in Lower Silesia - an important conservation practice and the management strategy in urban planning

NASA Astrophysics Data System (ADS)

Adamska, Maryna

2013-09-01

Buffer zones are narrow strips of land lying along the surface water, covered with appropriately selected vegetation. They separate aquatic ecosystems from the direct impact of agricultural land and reduce the movement of nutrients in the environment. In 2008 the European Commission established requirements for the implementation of buffer strips along water courses. Poland committed to the enforcement of these requirements until 1 January 2012. This was one of the reasons of this study. The subject of the analysis included the following rivers in Lower Silesia: Smortawa, Krynka, Czarna Woda and the selected transects of Ślęza and Nysa Łużycka. Detailed studies were designed to estimate the buffer zones occurring on these watercourses and assess these zones’ structure. This will be used to develop clear criteria for the selection of the width of these zones based on land use land management. It can be used in the implementation of executive acts at different levels of space management. Field research consisted of inventory the extent of riparian buffer strips on selected water courses and photographic documentation. Species composition of the vegetation forming a buffer zone was identified by using Braun-Blanquet method. There was lack of continuity of the riparian buffer zones on investigated rivers. Buffer zones should have carefully formulated definition and width because they are element of the significant ecological value, they perform important environmental protective functions and they are also the subject of Community law.

Reversing land degradation through grasses: a systematic meta-analysis in the Indian tropics

NASA Astrophysics Data System (ADS)

Mandal, Debashis; Srivastava, Pankaj; Giri, Nishita; Kaushal, Rajesh; Cerda, Artemi; Meherul Alam, Nurnabi

2017-02-01

Although intensive agriculture is necessary to sustain the world's growing population, accelerated soil erosion contributes to a decrease in the environmental health of ecosystems at local, regional and global scales. Reversing the process of land degradation using vegetative measures is of utmost importance in such ecosystems. The present study critically analyzes the effect of grasses in reversing the process of land degradation using a systematic review. The collected information was segregated under three different land use and land management situations. Meta-analysis was applied to test the hypothesis that the use of grasses reduces runoff and soil erosion. The effect of grasses was deduced for grass strip and in combination with physical structures. Similarly, the effects of grasses were analyzed in degraded pasture lands. The overall result of the meta-analysis showed that infiltration capacity increased approximately 2-fold after planting grasses across the slopes in agricultural fields. Grazing land management through a cut-and-carry system increased conservation efficiencies by 42 and 63 % with respect to reduction in runoff and erosion, respectively. Considering the comprehensive performance index (CPI), it has been observed that hybrid Napier (Pennisetum purpureum) and sambuta (Saccharum munja) grass seem to posses the most desirable attributes as an effective grass barrier for the western Himalayas and Eastern Ghats, while natural grass (Dichanthium annulatum) and broom grass (Thysanolaena maxima) are found to be most promising grass species for the Konkan region of the Western Ghats and the northeastern Himalayan region, respectively. In addition to these benefits, it was also observed that soil carbon loss can be reduced by 83 % with the use of grasses. Overall, efficacy for erosion control of various grasses was more than 60 %; hence, their selection should be based on the production potential of these grasses under given edaphic and agro-ecological conditions. The present analysis also indicated that grass must be used as a vegetative strip to maintain soil quality in sloppy arable areas (8.5 Mha) of Indian hilly regions. Similarly, due attention should be paid for establishing grasses in 3 Mha of degraded pasture lands and 3.5 Mha of shifting cultivation areas in India to reverse the land degradation.

The Strip-of-Grass Challenge

ERIC Educational Resources Information Center

Roman, Harry T.

2016-01-01

This brief article discusses various ways to use the grassy strip of land extending about three feet between the sidewalk and the street curb in many cities and neighborhoods. Next, it discusses the potential impact of different uses of this space on things like: people disembarking from their cars, clearance to existing fire hydrants, and town…

Environmental Assessment for the General Plan and Maintenance of Patrick Air Force Base, Florida

DTIC Science & Technology

2005-05-01

established potential to invade and disrupt native plant communities. Brazilian pepper, Australian pine, Melaleuca, cogon grass (Imperata cylindrical...other areas on base. Cogon grass is a hardy, invasive that has not been identified on PAFB, but has been observed in several Brevard County locations...narrow strip of vegetation bordered by the Atlantic Ocean, State Route A1A, Base Housing, or areas of mowed grass . Erosion has affected these dunes

A design aid for sizing filter strips using buffer area ratio

Treesearch

M.G. Dosskey; M.J. Helmers; D.E. Eisenhauer

2011-01-01

Nonuniform field runoff can reduce the effectiveness of filter strips that are a uniform size along a field margin. Effectiveness can be improved by placing more filter strip where the runoff load is greater and less where the load is smaller. A modeling analysis was conducted of the relationship between pollutant trapping efficiency and the ratio of filter strip area...

Watershed scale impacts of buffers and upland conservation practices on agrochemical delivery to streams

Treesearch

T.G. Franti; D.E. Eisenhauer; M.C. McCullough; L.M. Stahr; Mike G. Dosskey; D.D. Snow; R.F. Spalding; A.L. Boldt

2004-01-01

Conservation buffers are designed to reduce sediment and agrichemical runoff to surface water. Much is known about plot and field scale effectiveness of buffers; but little is known about their - watershed scale impact. Our objective was to estimate the watershed scale impact of grass buffers by comparing sediment and agrichemical losses from two adjacent 141 - 165...

Perennial grasses reduce woody plant seedlings...on mixed conifer fuel-break

Treesearch

Harry E. Schimke Lisle R. Green Danny Heavilin

1970-01-01

After initial clearing, parts of a fuelbreak on the Stanislaus Nationd Forest, central California, were planted to perennial grasses; other parts were not. After 5 years, a comparison between adjacent seeded sand unseeded strips shows that the perernnials had reduced the number of woody plant seedlings by a factor of 8, height of seedlings by 50 percent, and amount of...

Agroforestry buffers for nonpoint source pollution reductions from agricultural watersheds.

PubMed

Udawatta, Ranjith P; Garrett, Harold E; Kallenbach, Robert

2011-01-01

Despite increased attention and demand for the adoption of agroforestry practices throughout the world, rigorous long-term scientific studies confirming environmental benefits from the use of agroforestry practices are limited. The objective was to examine nonpoint-source pollution (NPSP) reduction as influenced by agroforestry buffers in watersheds under grazing and row crop management. The grazing study consists of six watersheds in the Central Mississippi Valley wooded slopes and the row crop study site consists of three watersheds in a paired watershed design in Central Claypan areas. Runoff water samples were analyzed for sediment, total nitrogen (TN), and total phosphorus (TP) for the 2004 to 2008 period. Results indicate that agroforestry and grass buffers on grazed and row crop management sites significantly reduce runoff, sediment, TN, and TP losses to streams. Buffers in association with grazing and row crop management reduced runoff by 49 and 19%, respectively, during the study period as compared with respective control treatments. Average sediment loss for grazing and row crop management systems was 13.8 and 17.9 kg ha yr, respectively. On average, grass and agroforestry buffers reduced sediment, TN, and TP losses by 32, 42, and 46% compared with the control treatments. Buffers were more effective in the grazing management practice than row crop management practice. These differences could in part be attributed to the differences in soils, management, and landscape features. Results from this study strongly indicate that agroforestry and grass buffers can be designed to improve water quality while minimizing the amount of land taken out of production. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

A review of vegetated buffers and a meta-analysis of their mitigation efficacy in reducing nonpoint source pollution.

PubMed

Zhang, Xuyang; Liu, Xingmei; Zhang, Minghua; Dahlgren, Randy A; Eitzel, Melissa

2010-01-01

Vegetated buffers are a well-studied and widely used agricultural management practice for reducing nonpoint-source pollution. A wealth of literature provides experimental data on their mitigation efficacy. This paper aggregated many of these results and performed a meta-analysis to quantify the relationships between pollutant removal efficacy and buffer width, buffer slope, soil type, and vegetation type. Theoretical models for removal efficacy (Y) vs. buffer width (w) were derived and tested against data from the surveyed literature using statistical analyses. A model of the form Y = K x (1-e(-bxw)), (0 < K < or = 100) successfully captured the relationship between buffer width and pollutant removal, where K reflects the maximum removal efficacy of the buffer and b reflects its probability to remove any single particle of pollutant in a unit distance. Buffer width alone explains 37, 60, 44, and 35% of the total variance in removal efficacy for sediment, pesticides, N, and P, respectively. Buffer slope was linearly associated with sediment removal efficacy either positively (when slope < or = 10%) or negatively (when slope > 10%). Buffers composed of trees have higher N and P removal efficacy than buffers composed of grasses or mixtures of grasses and trees. Soil drainage type did not show a significant effect on pollutant removal efficacy. Based on our analysis, a 30-m buffer under favorable slope conditions (approximately 10%) removes more than 85% of all the studied pollutants. These models predicting optimal buffer width/slope can be instrumental in the design, implementation, and modeling of vegetated buffers for treating agricultural runoff.

Is All Urban Green Space the Same? A Comparison of the Health Benefits of Trees and Grass in New York City.

PubMed

Reid, Colleen E; Clougherty, Jane E; Shmool, Jessie L C; Kubzansky, Laura D

2017-11-18

Living near vegetation, often called "green space" or "greenness", has been associated with numerous health benefits. We hypothesized that the two key components of urban vegetation, trees and grass, may differentially affect health. We estimated the association between near-residence trees, grass, and total vegetation (from the 2010 High Resolution Land Cover dataset for New York City (NYC)) with self-reported health from a survey of NYC adults (n = 1281). We found higher reporting of "very good" or "excellent" health for respondents with the highest, compared to the lowest, quartiles of tree (RR = 1.23, 95% CI = 1.06-1.44) but not grass density (relative risk (RR) = 1.00, 95% CI = 0.86-1.17) within 1000 m buffers, adjusting for pertinent confounders. Significant positive associations between trees and self-reported health remained after adjustment for grass, whereas associations with grass remained non-significant. Adjustment for air pollutants increased beneficial associations between trees and self-reported health; adjustment for parks only partially attenuated these effects. Results were null or negative using a 300 m buffer. Findings imply that higher exposure to vegetation, particularly trees outside of parks, may be associated with better health. If replicated, this may suggest that urban street tree planting may improve population health.

Effect of pH Test-Strip Characteristics on Accuracy of Readings.

PubMed

Metheny, Norma A; Gunn, Emily M; Rubbelke, Cynthia S; Quillen, Terrilynn Fox; Ezekiel, Uthayashanker R; Meert, Kathleen L

2017-06-01

Little is known about characteristics of colorimetric pH test strips that are most likely to be associated with accurate interpretations in clinical situations. To compare the accuracy of 4 pH test strips with varying characteristics (ie, multiple vs single colorimetric squares per calibration, and differing calibration units [1.0 vs 0.5]). A convenience sample of 100 upper-level nursing students with normal color vision was recruited to evaluate the accuracy of the test strips. Six buffer solutions (pH range, 3.0 to 6.0) were used during the testing procedure. Each of the 100 participants performed 20 pH tests in random order, providing a total of 2000 readings. The sensitivity and specificity of each test strip was computed. In addition, the degree to which the test strips under- or overestimated the pH values was analyzed using descriptive statistics. Our criterion for correct readings was an exact match with the pH buffer solution being evaluated. Although none of the test strips evaluated in our study was 100% accurate at all of the measured pH values, those with multiple squares per pH calibration were clearly superior overall to those with a single test square. Test strips with multiple squares per calibration were associated with greater overall accuracy than test strips with a single square per calibration. However, because variable degrees of error were observed in all of the test strips, use of a pH meter is recommended when precise readings are crucial. ©2017 American Association of Critical-Care Nurses.

7 CFR 1410.32 - CRP contract.

Code of Federal Regulations, 2011 CFR

2011-01-01

... conservation plan: (A) Grass waterways; (B) Filter strips; (C) Shallow water areas for wildlife; (D) Bottom... conservation compliance requirements of part 12 of this title to the extent applicable to other land. (h...

7 CFR 1410.32 - CRP contract.

Code of Federal Regulations, 2010 CFR

2010-01-01

... conservation plan: (A) Grass waterways; (B) Filter strips; (C) Shallow water areas for wildlife; (D) Bottom... conservation compliance requirements of part 12 of this title to the extent applicable to other land. (h...

Vegetative environmental buffers for reducing downwind odor and VOCs from tunnel-ventilated swine barn

USDA-ARS?s Scientific Manuscript database

Scientists have investigated methods for reducing odor emissions from livestock buildings for decades, yet few technologies have proven effective. Vegetative Environmental Buffers (VEBs), which are specially designed combinations of trees, shrubs and grasses, have shown promise in recent years for ...

Veterinary antibiotic sorption and transport through agroforestry buffer, grass buffer and cropland soils

USDA-ARS?s Scientific Manuscript database

Veterinary antibiotics (VAs), such as sulfamethazine (SMZ) are released into the environment by application of manure to agricultural fields. Understanding the fate and transport of VAs is important for assessing and mitigating possible environmental hazards. To study the effects of dissolved organi...

Soil quality indicator responses to row crop, grazed pasture, and agroforestry buffer management

USDA-ARS?s Scientific Manuscript database

Incorporation of trees and establishment of grass buffers within agroecosystems are management practices shown to enhance soil quality. Soil enzyme activities and water stable aggregates (WSA) have been identified as sensitive soil quality indicators to evaluate early responses to soil management. ...

APEX Model Simulation for Row Crop Watersheds with Agroforestry and Grass Buffers

USDA-ARS?s Scientific Manuscript database

Watershed model simulation has become an important tool in studying ways and means to reduce transport of agricultural pollutants. Conducting field experiments to assess buffer influences on water quality are constrained by the large-scale nature of watersheds, high experimental costs, private owner...

Area Strip Mine Reclamation Using Dredged Material: A Field Demonstration.

DTIC Science & Technology

1980-07-01

cut grass, barnyard grass, and nodding burr marigold . 43. All the plants are ubiquitous in their Chicago region distri- bution; i.e., they have a very... marigold (Figures 15, 16, and 18 in the main text). The open mudflat areas are inhabited almost solely by rud rooted sedge, sprangletop, oak-leaved...nigra BLUE VERVAIN Verbena hastata BOX ELDER Acer negundo BROAD-LEAVED CATTAIL Tyh latifolia BURR MARIGOLD Bidens polylepis BURNING BUSH Kochia scoparia

Mechanistic modeling & effectiveness of buffer strips for pesticide regulatory frameworks

USDA-ARS?s Scientific Manuscript database

Vegetative Filter Strips (VFS) have been used as an effective conservation practice in agricultural areas for controlling and mitigate the effect of sediment, nutrients and pesticides loads into water bodies. In addition to the agricultural sector, another important use of VFS for controlling plague...

Is All Urban Green Space the Same? A Comparison of the Health Benefits of Trees and Grass in New York City

PubMed Central

Clougherty, Jane E.; Shmool, Jessie L.C.; Kubzansky, Laura D.

2017-01-01

Living near vegetation, often called “green space” or “greenness”, has been associated with numerous health benefits. We hypothesized that the two key components of urban vegetation, trees and grass, may differentially affect health. We estimated the association between near-residence trees, grass, and total vegetation (from the 2010 High Resolution Land Cover dataset for New York City (NYC)) with self-reported health from a survey of NYC adults (n = 1281). We found higher reporting of “very good” or “excellent” health for respondents with the highest, compared to the lowest, quartiles of tree (RR = 1.23, 95% CI = 1.06–1.44) but not grass density (relative risk (RR) = 1.00, 95% CI = 0.86–1.17) within 1000 m buffers, adjusting for pertinent confounders. Significant positive associations between trees and self-reported health remained after adjustment for grass, whereas associations with grass remained non-significant. Adjustment for air pollutants increased beneficial associations between trees and self-reported health; adjustment for parks only partially attenuated these effects. Results were null or negative using a 300 m buffer. Findings imply that higher exposure to vegetation, particularly trees outside of parks, may be associated with better health. If replicated, this may suggest that urban street tree planting may improve population health. PMID:29156551

Utilizing vegetative environmental buffers to mitigate ammonia and particulate matter emissions from poultry houses

USDA-ARS?s Scientific Manuscript database

Vegetative Environmental Buffers (VEBs) are vegetation designed as a visual screen, which usually consist of trees, shrubs, grass and other potential plants. VEBs are placed around the poultry houses for the purpose of minimizing the air pollutant emissions. The expansion of the poultry industry due...

Vegetative environmental buffers and exhaust fan deflectors for reducing downwind odor and VOCs from tunnel-ventilated swine barns

USDA-ARS?s Scientific Manuscript database

Scientists have investigated methods for reducing odor emissions from livestock buildings for decades, yet few technologies have proven effective. Vegetative Environmental Buffers (VEB), which are specially designed combinations of trees, shrubs and grasses, have shown promise in recent years for r...

Nitrous Oxide Emissions from Riparian Forest Buffers, Warm-Season and Cool-Season Grass Filters, and Crop Fields

USDA-ARS?s Scientific Manuscript database

Increasing denitrification rates in riparian buffers may be trading the problem of nonpoint source (NPS) pollution of surface waters for atmospheric deterioration and increased global warming potential because denitrification produces nitrous oxide (N2O), a greenhouse gas also involved in stratosphe...

Effects of Terrestrial Buffer Zones on Amphibians on Golf Courses

PubMed Central

Puglis, Holly J.; Boone, Michelle D.

2012-01-01

A major cause of amphibian declines worldwide is habitat destruction or alteration. Public green spaces, such as golf courses and parks, could serve as safe havens to curb the effects of habitat loss if managed in ways to bolster local amphibian communities. We reared larval Blanchard's cricket frogs (Acris blanchardi) and green frogs (Rana clamitans) in golf course ponds with and without 1 m terrestrial buffer zones, and released marked cricket frog metamorphs at the golf course ponds they were reared in. Larval survival of both species was affected by the presence of a buffer zone, with increased survival for cricket frogs and decreased survival for green frogs when reared in ponds with buffer zones. No marked cricket frog juveniles were recovered at any golf course pond in the following year, suggesting that most animals died or migrated. In a separate study, we released cricket frogs in a terrestrial pen and allowed them to choose between mown and unmown grass. Cricket frogs had a greater probability of using unmown versus mown grass. Our results suggest that incorporating buffer zones around ponds can offer suitable habitat for some amphibian species and can improve the quality of the aquatic environment for some sensitive local amphibians. PMID:22761833

Introduction of biological agents into vegetative buffer to enhance rhizodegradation of atrazine

USDA-ARS?s Scientific Manuscript database

Introducing atrazine (ATR) degraders into riparian vegetative buffer strips (VBS) can be a promising bioremediation approach to accelerate the degradation of ATR and its degradation products deposited into VBS by surface runoff. A growth chamber study was conducted to investigated the synergistic ef...

Vehicle influence on permeation through intact and compromised skin.

PubMed

Gujjar, Meera; Banga, Ajay K

2014-09-10

The purpose of this study was to compare the transdermal permeation of a model compound, diclofenac diethylamine, from a hydrophilic and lipophilic vehicle across in vitro models simulating compromised skin. Mineral oil served as a lipophilic vehicle while 10mM phosphate buffered saline served as a hydrophilic vehicle. Compromised skin was simulated by tape stripping, delipidization, or microneedle application and compared with intact skin as a control. Transepidermal water loss was measured to assess barrier function. Skin compromised with tape stripping and delipidization significantly (p<0.05) increased permeation of diclofenac diethylamine compared to intact and microneedle treated skin with phosphate buffered saline vehicle. A similar trend in permeation was observed with mineral oil as the vehicle. For both vehicles, permeation across skin increased in the same order and correlated with degree of barrier impairment as indicated by transepidermal water loss values: intact

Enhanced dispersion and removal of ammonia emitted from a poultry house with a vegetative environmental buffer

USDA-ARS?s Scientific Manuscript database

Vegetative environmental buffers (VEBs), composed of tolerant trees, shrubs, and tall grasses, can be used to control and reduce the transport of ammonia (NH3) emissions from animal feeding operations (AFOs). However, the effectiveness of VEBs has not been quantitated. Here, we measure the dispersio...

AgBufferBuilder: A geographic information system (GIS) tool for precision design and performance assessment of filter strips

Treesearch

M. G. Dosskey; S. Neelakantan; T. G. Mueller; T. Kellerman; M. J. Helmers; E. Rienzi

2015-01-01

Spatially nonuniform runoif reduces the water qua1iry perfortnance of constant- width filter strips. A geographic inlormation system (Gls)-based tool was developed and tested that ernploys terrain analysis to account lor spatially nonuniform runoffand produce more ellbctive filter strip designs.The computer program,AgBufTerBuilder, runs with ATcGIS versions 10.0 and 10...

A review of vegetated buffers and a meta-analysis of their mitigation efficacy in reducing non-point source pollution

NASA Astrophysics Data System (ADS)

Zhang, X.; Liu, X.; Zhang, M.; Dahlgren, R. A.; Eitzel, M.

2009-12-01

Vegetated buffers are a well-studied and widely used agricultural management practice for reducing non-point source pollution. A wealth of literature provides experimental data on their mitigation efficacy. This paper aggregated many of these results and performed a meta-analysis to quantify the relationships between pollutant removal efficacy and buffer width, buffer slope, soil type, and vegetation type. Theoretical models for removal efficacy (Y) vs. buffer width (w) were derived and tested against data from the surveyed literature using statistical analyses. A model of the form Y = K x (1-exp(-b x w) , (0< K <= 100) successfully captured the relationship between buffer width and pollutant removal, where K reflects the maximum removal efficacy of the buffer and b reflects its probability to remove any single particle of pollutant in a unit distance. The estimates of K were 90.9, 93.2, 92.0, and 89.5 for sediment, pesticides, nitrogen (N) and phosphorus (P), respectively. Buffer width alone explains 37, 60, 44 and 35% of the total variance in removal efficacy for sediment, pesticides, N and P, respectively. Buffer slope was linearly associated with sediment removal efficacy either positively (when slope ≤ 10%) or negatively (when slope > 10%). Buffers composed of trees have higher N and P removal efficacy than buffers composed of grasses or mixtures of grasses and trees. Soil drainage type did not show a significant effect on pollutant removal efficacy. Models for all the studied pollutants were statistically significant with P-values < 0.001. Based on our analysis, a 30 m buffer under favorable slope conditions (≈ 10%) removes over 85% of all the studied pollutants. These models predicting optimal buffer width/slope can be instrumental in the design, implementation and modeling of vegetated buffers for treating agricultural runoff.

How did fixed-width buffers become standard practice for protecting freshwaters and their riparian areas from forest harvest practices?

Treesearch

John S. Richardson; Robert J. Naiman; Peter A. Bisson

2012-01-01

Riparian buffers provide improved protection for water quality and biota, and narrow, fixed-width buffers of native vegetation along streams have been used to mitigate the effects of forest harvest at least since the 1960s. The practice of leaving unmanaged strips of vegetation along water courses in agricultural lands had been used before the 1960s in southern Europe...

Reducing sedimentation of depressional wetlands in agricultural landscapes

USGS Publications Warehouse

Skagen, S.K.; Melcher, Cynthia; Haukos, D.A.

2008-01-01

Depressional wetlands in agricultural landscapes are easily degraded by sediments and contaminants accumulated from their watersheds. Several best management practices can reduce transport of sediments into wetlands, including the establishment of vegetative buffers. We summarize the sources, transport dynamics, and effect of sediments, nutrients, and contaminants that threaten wetlands and the current knowledge of design and usefulness of grass buffers for protecting isolated wetlands. Buffer effectiveness is dependent on several factors, including vegetation structure, buffer width, attributes of the surrounding watershed (i.e., area, vegetative cover, slope and topography, soil type and structure, soil moisture, amount of herbicides and pesticides applied), and intensity and duration of rain events. To reduce dissolved contaminants from runoff, the water must infiltrate the soil where microbes or other processes can break down or sequester contaminants. But increasing infiltration also diminishes total water volume entering a wetland, which presents threats to wetland hydrology in semi-arid regions. Buffer effectiveness may be enhanced significantly by implementing other best management practices (e.g., conservation tillage, balancing input with nutrient requirements for livestock and crops, precision application of chemicals) in the surrounding watershed to diminish soil erosion and associated contaminant runoff. Buffers require regular maintenance to remove sediment build-up and replace damaged or over-mature vegetation. Further research is needed to establish guidelines for effective buffer width and structure, and such efforts should entail a coordinated, regional, multi-scale, multidisciplinary approach to evaluate buffer effectiveness and impacts. Direct measures in "real-world" systems and field validations of buffer-effectiveness models are crucial next steps in evaluating how grass buffers will impact the abiotic and biotic variables attributes that characterize small, isolated wetlands. ?? 2008 The Society of Wetland Scientists.

Perennial Grass and Native Wildflowers: A Synergistic Approach to Habitat Management.

PubMed

Xavier, Shereen S; Olson, Dawn M; Coffin, Alisa W; Strickland, Timothy C; Schmidt, Jason M

2017-09-22

Marginal agricultural land provides opportunities to diversify landscapes by producing biomass for biofuel, and through floral provisioning that enhances arthropod-mediated ecosystem service delivery. We examined the effects of local spatial context (adjacent to woodland or agriculture) and irrigation (irrigation or no irrigation) on wildflower bloom and visitation by arthropods in a biofeedstocks-wildflower habitat buffer design. Twenty habitat buffer plots were established containing a subplot of Napier grass ( Pennisetum perpureum Schumach) for biofeedstock, three commercial wildflower mix subplots, and a control subplot containing spontaneous weeds. Arthropods and flowers were visually observed in quadrats throughout the season. At the end of the season we measured soil nutrients and harvested Napier biomass. We found irrespective of buffer location or irrigation, pollinators were observed more frequently early in the season and on experimental plots with wildflowers than on weeds in the control plots. Natural enemies showed a tendency for being more common on plots adjacent to a wooded border, and were also more commonly observed early in the season. Herbivore visits were infrequent and not significantly influenced by experimental treatments. Napier grass yields were high and typical of first-year yields reported regionally, and were not affected by location context or irrigation. Our results suggest habitat management designs integrating bioenergy crop and floral resources provide marketable biomass and habitat for beneficial arthropods.

Perennial grass and native wildflowers: a synergistic approach to habitat management

USDA-ARS?s Scientific Manuscript database

A total of 19 buffer plots were established on University of Georgia experimental farms and lands near Tifton, GA in 2015. The buffer plots were assigned to a 2 x 2 design of local spatial context and irrigation. For local spatial context, ten plots were located adjacent to woodland (“T”) and ten in...

Effectiveness of vegetation buffers surrounding playa wetlands at contaminant and sediment amelioration

USGS Publications Warehouse

Haukos, David A.; Johnson, Lacrecia A.; Smith, Loren M.; McMurry, Scott T.

2016-01-01

Playa wetlands, the dominant hydrological feature of the semi-arid U.S. High Plains providing critical ecosystem services, are being lost and degraded due to anthropogenic alterations of the short-grass prairie landscape. The primary process contributing to the loss of playas is filling of the wetland through accumulation of soil eroded and transported by precipitation from surrounding cultivated watersheds. We evaluated effectiveness of vegetative buffers surrounding playas in removing metals, nutrients, and dissolved/suspended sediments from precipitation runoff. Storm water runoff was collected at 10-m intervals in three buffer types (native grass, fallow cropland, and Conservation Reserve Program). Buffer type differed in plant composition, but not in maximum percent removal of contaminants. Within the initial 60 m from a cultivated field, vegetation buffers of all types removed >50% of all measured contaminants, including 83% of total suspended solids (TSS) and 58% of total dissolved solids (TDS). Buffers removed an average of 70% of P and 78% of N to reduce nutrients entering the playa. Mean maximum percent removal for metals ranged from 56% of Na to 87% of Cr. Maximum removal was typically at 50 m of buffer width. Measures of TSS were correlated with all measures of metals and nutrients except for N, which was correlated with TDS. Any buffer type with >80% vegetation cover and 30–60 m in width would maximize contaminant removal from precipitation runoff while ensuring that playas would continue to function hydrologically to provide ecosystem services. Watershed management to minimize erosion and creations of vegetation buffers could be economical and effective conservation tools for playa wetlands.

Interplanting Annual Ryegrass, Wheat, Oat, and Corn to Mitigate Iron Deficiency in Dry Beans

PubMed Central

Omondi, Emmanuel Chiwo; Kniss, Andrew R.

2014-01-01

This study evaluated whether grass intercropping can be used to alleviate Fe deficiency chlorosis in dry beans (Phaseolus vulgaris L.) grown in high pH, calcareous soils with low organic matter. Field studies were conducted at the University of Wyoming Sustainable Agriculture Research and Extension Center in 2009 and 2010. Black- and navy beans were grown alone or intercropped with annual ryegrass (Lolium multiflorum Lam.), oat (Avena sativa L.), corn (Zea mays L.), or spring wheat (Triticum aestivum L.) in a two-factor factorial strip-plot randomized complete block design. All four grass species increased chlorophyll intensity in dry beans. However, grass species did not increase iron (Fe) concentration in dry bean tissues suggesting inefficient utilization of Fe present in the dry bean tissues. In 2009, nitrate-nitrogen (NO3-N) and manganese (Mn) concentration in bean tissue were greater in bean monoculture than in grass intercropped beans. Bean monoculture also had greater soil NO3-N concentrations than grass intercropped treatments. In 2009, grass intercrops reduced dry bean yield >25% compared to bean monoculture. Annual ryegrass was the least competitive of the four annual grass species. This suggests that competition from grasses for nutrients, water, or light may have outweighed benefits accruing from grass intercropping. Additional studies are required to determine the appropriate grass and dry bean densities, as well as the optimum time of grass removal. PMID:25536084

Interplanting annual ryegrass, wheat, oat, and corn to mitigate iron deficiency in dry beans.

PubMed

Omondi, Emmanuel Chiwo; Kniss, Andrew R

2014-01-01

This study evaluated whether grass intercropping can be used to alleviate Fe deficiency chlorosis in dry beans (Phaseolus vulgaris L.) grown in high pH, calcareous soils with low organic matter. Field studies were conducted at the University of Wyoming Sustainable Agriculture Research and Extension Center in 2009 and 2010. Black- and navy beans were grown alone or intercropped with annual ryegrass (Lolium multiflorum Lam.), oat (Avena sativa L.), corn (Zea mays L.), or spring wheat (Triticum aestivum L.) in a two-factor factorial strip-plot randomized complete block design. All four grass species increased chlorophyll intensity in dry beans. However, grass species did not increase iron (Fe) concentration in dry bean tissues suggesting inefficient utilization of Fe present in the dry bean tissues. In 2009, nitrate-nitrogen (NO3-N) and manganese (Mn) concentration in bean tissue were greater in bean monoculture than in grass intercropped beans. Bean monoculture also had greater soil NO3-N concentrations than grass intercropped treatments. In 2009, grass intercrops reduced dry bean yield >25% compared to bean monoculture. Annual ryegrass was the least competitive of the four annual grass species. This suggests that competition from grasses for nutrients, water, or light may have outweighed benefits accruing from grass intercropping. Additional studies are required to determine the appropriate grass and dry bean densities, as well as the optimum time of grass removal.

Hydroseeding on anthracite coal-mine spoils

Treesearch

Miroslaw M. Czapowskyj; Ross Writer

1970-01-01

A study was made of the performance of selected species of legumes, grasses, and trees hydroseeded on anthracite coal-mine spoils in a slurry of lime, fertilizer, and mulch. Hydroseeding failed on coal-breaker refuse, but was partially successful on strip-mine spoils.

Effects of native perennial vegetation buffer strips on dissolved organic carbon in surface runoff from an agricultural landscape

Treesearch

Tomorra E. Smith; Randall K. Kolka; Xiaobo Zhou; Matthew J. Helmers; Richard M. Cruse; Mark D. Tomer

2014-01-01

Dissolved organic carbon (DOC) constitutes a small yet important part of a watershed's carbon budget because it is mobile and biologically active. Agricultural conservation practices such as native perennial vegetation (NPV) strips will influence carbon cycling of an upland agroecosystem, and could affect how much DOC enters streams in runoff, potentially...

Effects of vegetation on runoff generation, sediment yield and soil shear strength on road-side slopes under a simulation rainfall test in the Three Gorges Reservoir Area, China.

PubMed

Liu, Yao-Jun; Wang, Tian-Wei; Cai, Chong-Fa; Li, Zhao-Xia; Cheng, Dong-Bing

2014-07-01

Vegetation recolonization has often been used to control roadside slope erosion, and in this paper, four restoration models - Natural Restoration, Grass, Grass & Shrub, Sodded Strip - were chosen to recolonize the plants on a newly built unpaved roadside slope in the Three Gorges Reservoir Area. After eight months growth, eight rainfall simulations (intensity of 90 mm h(-1) for 60 min) and in-situ soil shear strength test were then carried out to identify the impacts of vegetation on roadside slope erosion and soil shear strength. The erosion on cutslopes was higher than that on fillslopes. The runoff coefficient and soil detachment rate were significantly lower on the Grass & Shrub model (4.3% and 1.99 g m(-2) min(-1), respectively) compared with the other three, which had the highest surface cover (91.4%), aboveground biomass (1.44 kg m(-2)) and root weight density (3.94 kg m(-3)). The runoff coefficient and soil detachment rate on roadside slopes showed a logarithmic decrease with the root weight density, root length density and aboveground biomass. The soil shear strength measured before and after the rainfall was higher on Grass & Shrub (59.29 and 53.73 kPa) and decreased on Grass (46.93 and 40.48 kPa), Sodded Strip (31.20 and 18.87 kPa) and Natural Restoration (25.31 and 9.36 kPa). Negative linear correlations were found between the soil shear strength reduction and aboveground biomass, root weight density and root length density. The variation of soil shear strength reduction was closely related to the roadside slope erosion, a positive linear correlation was found between runoff coefficient and soil shear strength reduction, and a power function was shown between soil detachment rate and soil shear strength reduction. This study demonstrated that Grass and Grass & Shrub were more suitable and highly cost-effective in controlling initial period erosion of newly built low-volume unpaved road. Copyright © 2014 Elsevier B.V. All rights reserved.

Perennial Grass and Native Wildflowers: A Synergistic Approach to Habitat Management

PubMed Central

Xavier, Shereen S.; Olson, Dawn M.; Coffin, Alisa W.; Strickland, Timothy C.; Schmidt, Jason M.

2017-01-01

Marginal agricultural land provides opportunities to diversify landscapes by producing biomass for biofuel, and through floral provisioning that enhances arthropod-mediated ecosystem service delivery. We examined the effects of local spatial context (adjacent to woodland or agriculture) and irrigation (irrigation or no irrigation) on wildflower bloom and visitation by arthropods in a biofeedstocks-wildflower habitat buffer design. Twenty habitat buffer plots were established containing a subplot of Napier grass (Pennisetum perpureum Schumach) for biofeedstock, three commercial wildflower mix subplots, and a control subplot containing spontaneous weeds. Arthropods and flowers were visually observed in quadrats throughout the season. At the end of the season we measured soil nutrients and harvested Napier biomass. We found irrespective of buffer location or irrigation, pollinators were observed more frequently early in the season and on experimental plots with wildflowers than on weeds in the control plots. Natural enemies showed a tendency for being more common on plots adjacent to a wooded border, and were also more commonly observed early in the season. Herbivore visits were infrequent and not significantly influenced by experimental treatments. Napier grass yields were high and typical of first-year yields reported regionally, and were not affected by location context or irrigation. Our results suggest habitat management designs integrating bioenergy crop and floral resources provide marketable biomass and habitat for beneficial arthropods. PMID:28937651

Long-term effects of drinking-water treatment residuals on dissolved phosphorus export from vegetated buffer strips.

PubMed

Habibiandehkordi, Reza; Quinton, John N; Surridge, Ben W J

2015-04-01

The export of dissolved phosphorus (P) in surface runoff from agricultural land can lead to water quality degradation. Surface application of aluminium (Al)-based water treatment residuals (Al-WTRs) to vegetated buffer strip (VBS) soils can enhance P removal from surface runoff during single runoff events. However, the longer-term effects on P removal in VBSs following application of products such as Al-WTR remain uncertain. We used field experimental plots to examine the long-term effects of applying a freshly generated Al-WTR to VBSs on dissolved P export during multiple runoff events, occurring between 1 day and 42 weeks after the application of Al-WTR. Vegetated buffer strip plots amended with Al-WTR significantly reduced soluble reactive P and total dissolved P concentrations in surface runoff compared to both unamended VBS plots and control plots. However, the effectiveness of Al-WTR decreased over time, by approximately 70% after 42 weeks compared to a day following Al-WTR application. Reduced performance did not appear to be due to drying of Al-WTR in the field. Instead, the development of preferential flow paths as well as burying of Al-WTR with freshly deposited sediments may explain these observations. Better understanding of the processes controlling long-term P removal by Al-WTR is required for effective management of VBSs.

Soil conservation through sediment trapping: A review

NASA Astrophysics Data System (ADS)

Mekonnen, Mulatie; Keesstra, Saskia; Baartman, Jantiene; Maroulis, Jerry; Stroosnijder, Leo

2014-05-01

Preventing the off-site effects of soil erosion is an essential part of good catchment management. Most efforts are in the form of on-site soil and water conservation measures. However, sediment trapping (ST) can be an alternative (or additional) measure to prevent the negative off-site effects of soil erosion. Therefore, not all efforts should focus solely on on-site soil conservation, but also on the safe routing of sediment-laden flows and on creating sites and conditions where sediment can be trapped, preferably in a cost effective or even profitable way. ST can be applied on-site (in-field) and off-site and involves both vegetative and structural measures. The main vegetative measures include grass strips, tree or bush buffers, grassed waterways and restoration of the waterways and their riparian zone; while structural measures include terraces, ponds and check dams. This paper provides a review of studies that have assessed the sediment trapping efficacy (STE) of such vegetative and structural measures. Vegetation type and integration of two or more measures (vegetative as well as structural) are important factors influencing STE. In this review, the STE of most measures was evaluated either individually or in such combinations. In real landscape situations, it is not only important to select the most efficient erosion control measures, but also to determine their optimum location in the catchment. Hence, there is a need for research that shows a more integrated determination of STE at the catchment scale. If integrated measures are implemented at the most appropriate spatial locations within a catchment where they can disconnect landscape units from each other, they will decrease runoff velocity and sediment transport and, subsequently, reduce downstream flooding and sedimentation problems. KEY WORDS: Integrated sediment trapping, sediment trapping efficacy, vegetative, structural, on-site and off-site measures.

Experiences gained from implementing mandatory buffer strips in Denmark: how can we enhance their ecosystem services?

NASA Astrophysics Data System (ADS)

Kronvang, Brian; Hoffmann, Carl Christian; Baattrup-Pedersen, Annette; Hille, Sandra; Rubæk, Gitte; Heckrath, Goswin; Gertz, Flemming; Jensen, Henning; Feuerback, Peter; Strand, John; Stutter, Marc

2015-04-01

The Danish Parliament adopted in June 2012 a Buffer Strip Act that required 10 m mandatory buffer strips (BSs) to be established along all watercourses and lakes with a surface area greater than 100 m2 from 1st September 2012. The main reasons for deploying BSs was to reduce nitrate-N leaching and phosphorus (P) loss via surface runoff from adjoining fields from the approximately 50,000 ha of BSs as no farming activities were allowed in the BS concerning use of fertilizer, spreading of manure, spraying with pesticides, etc. Reductions in nutrient losses to watercourses are needed for minimizing the eutrophication effects in lakes and coastal waters. Buffer strips are among the most well studied and frequently adapted mitigation measure for reducing sediment and P losses to surface waters via surface runoff. It has, however, been questioned if BSs can also reduce N losses. The international literature gives an overwhelming support to their functioning for reduction in sediment and especially particulate P losses. However, their functioning for dissolved P and nitrogen is more questionable when comparing studies from the international literature. In Denmark, many farmers were against the introduction of BSs as a general mitigation measure for several reasons. The most used argument in the public debate was that BSs in general are not very efficient for reducing N and P losses to surface waters which was originally the argument behind the BS Act from the Ministries of Environment and Food and Agriculture. A desk study had been made prior to the adaptation of the law that showed 10 m BSs to be able to reduce the N loading with 40-50 kg N ha-1 of BS and 0.04-0.4 kg P ha-1 BS. The total reduction from the BSs established in Denmark in 2012 would then amount to 2,000-2,500 tonnes N and 2-20 tonnes P. The intense public debate in Denmark made the Parliament to adopt a new BS law in June 2014 to be implemented in August 2014 that reduced the total areas with mandatory BSs along watercourses from ca. 50,000 ha to ca. 25,000 ha and at the same time they reduced the width of the mandatory BSs from 10 m to 9 m. The aim of this presentation is to share the experience gained in Denmark on establishing mandatory BSs. Furthermore, we will show some preliminary results from two newly initiated research projects (BUFFERTECH and BALTICSEA2020) that studies how to enhance the ecosystem services provided by buffer strips. We will show how intelligently to guide managers when establishing BSs along watercourses at catchment scale utilizing a combined P-index model for soil erosion and a statistical model for P retention in BSs as well as results obtained from new 'Engineered' or 'Constructed' BSs that delays tile drainage flow from field to streams thereby increasing nutrient retention. Acknowledgement The work is supported by the Strategic Research Foundation/Innovation Fund Denmark project 'BUFFERTECH - Optimization of Ecosystem Services Provided by Buffer Strips Using Novel Technological Methods' (Grant No. 1305-00017B) and the BalticSea2020 project 'Integrerade skyddszoner (IBZ)'.

Helium: lifting high-performance stencil kernels from stripped x86 binaries to halide DSL code

DOE PAGES

Mendis, Charith; Bosboom, Jeffrey; Wu, Kevin; ...

2015-06-03

Highly optimized programs are prone to bit rot, where performance quickly becomes suboptimal in the face of new hardware and compiler techniques. In this paper we show how to automatically lift performance-critical stencil kernels from a stripped x86 binary and generate the corresponding code in the high-level domain-specific language Halide. Using Halide's state-of-the-art optimizations targeting current hardware, we show that new optimized versions of these kernels can replace the originals to rejuvenate the application for newer hardware. The original optimized code for kernels in stripped binaries is nearly impossible to analyze statically. Instead, we rely on dynamic traces to regeneratemore » the kernels. We perform buffer structure reconstruction to identify input, intermediate and output buffer shapes. Here, we abstract from a forest of concrete dependency trees which contain absolute memory addresses to symbolic trees suitable for high-level code generation. This is done by canonicalizing trees, clustering them based on structure, inferring higher-dimensional buffer accesses and finally by solving a set of linear equations based on buffer accesses to lift them up to simple, high-level expressions. Helium can handle highly optimized, complex stencil kernels with input-dependent conditionals. We lift seven kernels from Adobe Photoshop giving a 75 % performance improvement, four kernels from Irfan View, leading to 4.97 x performance, and one stencil from the mini GMG multigrid benchmark netting a 4.25 x improvement in performance. We manually rejuvenated Photoshop by replacing eleven of Photoshop's filters with our lifted implementations, giving 1.12 x speedup without affecting the user experience.« less

Buffer substitution in malaria rapid diagnostic tests causes false-positive results

PubMed Central

2010-01-01

Background Malaria rapid diagnostic tests (RDTs) are kits that generally include 20 to 25 test strips or cassettes, but only a single buffer vial. In field settings, laboratory staff occasionally uses saline, distilled water (liquids for parenteral drugs dilution) or tap water as substitutes for the RDT kit's buffer to compensate for the loss of a diluent bottle. The present study assessed the effect of buffer substitution on the RDT results. Methods Twenty-seven RDT brands were run with EDTA-blood samples of five malaria-free subjects, who were negative for rheumatoid factor and antinuclear antibodies. Saline, distilled water and tap water were used as substitute liquids. RDTs were also run with distilled water, without adding blood. Results were compared to those obtained with the RDT kit's buffer and Plasmodium positive samples. Results Only eight cassettes (in four RDT brands) showed no control line and were considered invalid. Visible test lines occurred for at least one malaria-free sample and one of the substitutes in 20/27 (74%) RDT brands (saline: n = 16; distilled water: n = 17; and tap water: n = 20), and in 15 RDTs which were run with distilled water only. They occurred for all Plasmodium antigens and RDT formats (two-, three- and four-band RDTs). Clearance of the background of the strip was excellent except for saline. The aspects (colour, intensity and crispness) of the control and the false-positive test lines were similar to those obtained with the RDT kits' buffer and Plasmodium positive samples. Conclusion Replacement of the RDT kit's dedicated buffer by saline, distilled water and tap water can cause false-positive test results. PMID:20650003

Integrating economic and biophysical data in assessing cost-effectiveness of buffer strip placement.

PubMed

Balana, Bedru Babulo; Lago, Manuel; Baggaley, Nikki; Castellazzi, Marie; Sample, James; Stutter, Marc; Slee, Bill; Vinten, Andy

2012-01-01

The European Union Water Framework Directive (WFD) requires Member States to set water quality objectives and identify cost-effective mitigation measures to achieve "good status" in all waters. However, costs and effectiveness of measures vary both within and between catchments, depending on factors such as land use and topography. The aim of this study was to develop a cost-effectiveness analysis framework for integrating estimates of phosphorus (P) losses from land-based sources, potential abatement using riparian buffers, and the economic implications of buffers. Estimates of field-by-field P exports and routing were based on crop risk and field slope classes. Buffer P trapping efficiencies were based on literature metadata analysis. Costs of placing buffers were based on foregone farm gross margins. An integrated optimization model of cost minimization was developed and solved for different P reduction targets to the Rescobie Loch catchment in eastern Scotland. A target mean annual P load reduction of 376 kg to the loch to achieve good status was identified. Assuming all the riparian fields initially have the 2-m buffer strip required by the General Binding Rules (part of the WFD in Scotland), the model gave good predictions of P loads (345-481 kg P). The modeling results show that riparian buffers alone cannot achieve the required P load reduction (up to 54% P can be removed). In the medium P input scenario, average costs vary from £38 to £176 kg P at 10% and 54% P reduction, respectively. The framework demonstrates a useful tool for exploring cost-effective targeting of environmental measures. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Developing NanoFoil-Heated Thin-Film Thermal Battery

DTIC Science & Technology

2013-09-01

buffer discs (in gray) sandwiching the NanoFoil disc (in yellow). Two Microtherm discs (in dark gray) bracketed the sandwich to prevent excessive heat...of the fuse strip with a Microtherm disc. Cathode Electrolyte Anode Microtherm Heat paper NanoFoil Buffer Agilent 34970A 606.5 Nichrome wire Maccor...gray) sandwiching the NanoFoil disc (in yellow). Two Microtherm discs (in dark gray) bracketed the sandwich to prevent excessive heat loss

Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion.

PubMed

Zhou, Xiaobo; Helmers, Matthew J; Asbjornsen, Heidi; Kolka, Randy; Tomer, Mark D

2010-01-01

Many croplands planted to perennial grasses under the Conservation Reserve Program are being returned to crop production, and with potential consequences for water quality. The objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (NO3-N) concentrations in soil and shallow groundwater and to assess the potential for perennial filter strips (PFS) to mitigate increases in NO3-N levels. The study, conducted at the Neal Smith National Wildlife Refuge (NSNWR) in central Iowa, consisted of a balanced incomplete block design with 12 watersheds and four watershed-scale treatments having different proportions and topographic positions of PFS planted in native prairie grasses: 100% rowcrop, 10% PFS (toeslope position), 10% PFS (distributed on toe and as contour strips), and 20 PFS (distributed on toe and as contour strips). All treatments were established in fall 2006 on watersheds that were under bromegrass (Bromus L.) cover for at least 10 yr. Nonperennial areas were maintained under a no-till 2-yr corn (Zea mays L.)--soybean [Glycine max. (L.) Merr.] rotation since spring 2007. Suction lysimeter and shallow groundwater wells located at upslope and toeslope positions were sampled monthly during the growing season to determine NO3-N concentration from 2005 to 2008. The results indicated significant increases in NO3-N concentration in soil and groundwater following grassland-to-cropland conversion. Nitrate-nitrogen levels in the vadose zone and groundwater under PFS were lower compared with 100% cropland, with the most significant differences occurring at the toeslope position. During the years following conversion, PFS mitigated increases in subsurface nitrate, but long-term monitoring is needed to observe and understand the full response to land-use conversion.

Current-use pesticides in stream water and suspended particles following runoff: exposure, effects, and mitigation requirements.

PubMed

Bereswill, Renja; Streloke, Martin; Schulz, Ralf

2013-06-01

The European Union's directive for sustainable use of pesticides requires implementing risk mitigation measures at streams threatened by pesticide entries. The need for mitigation measures was investigated at 10 stream sites within an intensively used arable region in central Germany by characterizing pesticide exposure following edge-of-field runoff and effects on the aquatic macroinvertebrates. Moreover, the influence of riparian buffer strip width (as a mitigation measure) at the sampling sites was considered. Generally, invertebrate fauna was dominated by pesticide-tolerant species, suggesting a high pesticide exposure at almost all sites. This result is also reflected by the elevated levels of suspended particle contamination in terms of toxic units (logTUMax  > -2), corresponding to one-hundredth of the median lethal concentration (LC50) to Daphnia magna. At two sites that received high aqueous-phase entries of the pyrethroid lambda-cyhalothrin (logTUMax  > -0.6), the abundance and number of sensitive species in terms of the species at risk index decreased during the pesticide application period. In contrast, no acute significant negative effects on macroinvertebrates were observed at sites characterised by low water-phase toxicity (logTUMax  < -3.5). An influence of riparian buffer strip width on pesticide exposure was not observed, supposedly because of the presence of erosion rills and ephemeral ditches. In conclusion, results show that mitigation measures (such as the improvement of currently present riparian buffer strips) are needed in the study area. Copyright © 2013 SETAC.

Determination of carmine food dye (E120) in foodstuffs by stripping voltammetry.

PubMed

Alghamdi, Ahmad H; Alshammery, Hamed M; Abdalla, Mohamed A; Alghamdi, Ali F

2009-01-01

The behavior of the food colorant agent carmine (E120) was studied by square-wave adsorptive stripping voltammetry (SW-AdSV) at the hanging mercury drop electrode. It was observed that carmine gave a sensitive stripping voltammetric peak at -350 mV in pH 3 acetate buffer. The cyclic voltammetric technique was also used to characterize the electrochemical reduction process of carmine. The adsorptive voltammetric signal was evaluated with respect to various experimental conditions, and the optimized values were supporting electrolyte, acetate buffer; buffer acidity, pH 3; dye concentration, 3 x 10(-7) M; accumulation time, 150 s; accumulation potential, -0.2 V; scan rate, 300 mV/s; pulse amplitude, 185 mV; SW frequency, 20 Hz; working electrode area, 0.6 mm2; and convection rate, 2600 rpm. The SW-AdSV peak currents depended linearly on the concentration of carmine from 5 x 10(-8) to 1.25 x 10(-7) mol/L (r = 0.99). A detection limit of 1.43 x 10(-9) mol/L with an RSD of 2.2% and a mean recovery of 97.9% were obtained. Possible interferences by several substances usually present in food products such as food additive dyes (E102, E100, E123, E127, and E129), artificial sweeteners, preservatives, and antioxidants were also evaluated. The proposed electrochemical procedure was successfully applied to the determination of carmine food dye in spiked commercially available ice cream and soft drinks.

Age-Related Alterations in Regeneration of the Urinary Bladder after Subtotal Cystectomy

DTIC Science & Technology

2013-11-01

buffer. The bladders were cut into approximately equally sized strips along the longitudinal axis. The strips were denuded of the urothelium and sub... urothelium and then were attached to tissue holds at one end and to force transducers at the other end in an organ bath system (Danish Myo Technology...of the urothelium and the bladder wall to reseal immediately after STC in old animals. This suppo- sition is consistent with the decreased PCNA

Wintering bird response to fall mowing of herbaceous buffers

USGS Publications Warehouse

Blank, P.J.; Parks, J.R.; Dively, G.P.

2011-01-01

Herbaceous buffers are strips of herbaceous vegetation planted between working agricultural land and streams or wetlands. Mowing is a common maintenance practice to control woody plants and noxious weeds in herbaceous buffers. Buffers enrolled in Maryland's Conservation Reserve Enhancement Program (CREP) cannot be mowed during the primary bird nesting season between 15 April and 15 August. Most mowing of buffers in Maryland occurs in late summer or fall, leaving the vegetation short until the following spring. We studied the response of wintering birds to fall mowing of buffers. We mowed one section to 10-15 cm in 13 buffers and kept another section unmowed. Ninety-two percent of birds detected in buffers were grassland or scrub-shrub species, and 98% of all birds detected were in unmowed buffers. Total bird abundance, species richness, and total avian conservation value were significantly greater in unmowed buffers, and Savannah Sparrows (Passerculus sandwichensis), Song Sparrows (Melospiza melodia), and White-throated Sparrows (Zonotrichia albicollis) were significantly more abundant in unmowed buffers. Wintering bird use of mowed buffers was less than in unmowed buffers. Leaving herbaceous buffers unmowed through winter will likely provide better habitat for wintering birds. ?? 2011 by the Wilson Ornithological Society.

Use of Fuzzy rainfall-runoff predictions for claypan watersheds with conservation buffers in Northeast Missouri

NASA Astrophysics Data System (ADS)

Anomaa Senaviratne, G. M. M. M.; Udawatta, Ranjith P.; Anderson, Stephen H.; Baffaut, Claire; Thompson, Allen

2014-09-01

Fuzzy rainfall-runoff models are often used to forecast flood or water supply in large catchments and applications at small/field scale agricultural watersheds are limited. The study objectives were to develop, calibrate, and validate a fuzzy rainfall-runoff model using long-term data of three adjacent field scale row crop watersheds (1.65-4.44 ha) with intermittent discharge in the claypan soils of Northeast Missouri. The watersheds were monitored for a six-year calibration period starting 1991 (pre-buffer period). Thereafter, two of them were treated with upland contour grass and agroforestry (tree + grass) buffers (4.5 m wide, 36.5 m apart) to study water quality benefits. The fuzzy system was based on Mamdani method using MATLAB 7.10.0. The model predicted event-based runoff with model performance coefficients of r2 and Nash-Sutcliffe Coefficient (NSC) values greater than 0.65 for calibration and validation. The pre-buffer fuzzy system predicted event-based runoff for 30-50 times larger corn/soybean watersheds with r2 values of 0.82 and 0.68 and NSC values of 0.77 and 0.53, respectively. The runoff predicted by the fuzzy system closely agreed with values predicted by physically-based Agricultural Policy Environmental eXtender model (APEX) for the pre-buffer watersheds. The fuzzy rainfall-runoff model has the potential for runoff predictions at field-scale watersheds with minimum input. It also could up-scale the predictions for large-scale watersheds to evaluate the benefits of conservation practices.

Green strips or vegetative fuel breaks

Treesearch

Loren St. John; Dan Ogle

2009-01-01

According to the National Interagency Fire Center, between 1998 and 2008 there were on average 65,581 fires per year and an average of 6,114,135 acres burned each year in the United States. Rangelands in the western United States have been invaded by many annual weed species including cheatgrass, an introduced winter annual grass that produces large quantities of...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foltyn, Stephen R; Jia, Quanxi; Arendt, Paul N

A superconducting tape having reduced AC losses. The tape has a high temperature superconductor layer that is segmented. Disruptive strips, formed in one of the tape substrate, a buffer layer, and the superconducting layer create parallel discontinuities in the superconducting layer that separate the current-carrying elements of the superconducting layer into strips or filament-like structures. Segmentation of the current-carrying elements has the effect of reducing AC current losses. Methods of making such a superconducting tape and reducing AC losses in such tapes are also disclosed.

High Efficiency Photovoltaic and Plasmonic Devices

DTIC Science & Technology

2011-07-01

on Si or SOI substrate along with its band alignment. This elongated mesa forms a strip channel aveguide……………………………….…4 Figure 3 Radiative and...lattice matched GeSn relaxed buffer on Si or SOI substrate along with its band alignment. This elongated mesa forms a strip channel waveguide...Appl. Phys. Lett. 90, 251105 (2007). 8. R. A. Soref and C. H. Perry, J. Appl. Phys. 69, 539 (1991). 9. H. P. L. de Guevara, A. G. Rodriguez , H

GENERAL DESIGN CONSIDERATIONS IN BMP DESIGN

EPA Science Inventory

Today, many municipalities are implementing best management practices (BMPs). The most commonly used structural treatment BMPs that will be discussed in the presentation are ponds (detention/retention) and vegetated biofilters (swales and filter/buffer strips).

Historical...

A Comparison of Buffer Strip and Non-Buffer Strip Joint Designs

DTIC Science & Technology

1976-06-01

Oil — +• i£ < Uj^ * «H aiLWUJZf—*a-JJ«oou • z ><<QI 1— 2+ 2: uj»-<oo<»-«_Ja:’-,z...a O 1- O <r £ • r\\l (N00 *X m 00 -^ CUJ — 3 Ol-Z — 1 2 1- u_ ^ X OIL —X 1 QO« r\\J* O O H- — -3 a —00 -ZZ— r— 1 1— X 3— —» • 00 •—< «o Z< 1 Z(NJ...2:<r< z< 2: lls: 1— o<oa lu —• 1— —1 1 .-. +— >-— — < < uizZsq zz x a lulu 1 oo(\\j+ 00+ 00 t— cc z o —**-* h- oil — x •>* in •n-oom <- — . #

Evaluation of sources of variation on in vitro fermentation kinetics of feedstuffs in a gas production system.

PubMed

Keim, Juan P; Alvarado-Gilis, Christian; Arias, Rodrigo A; Gandarillas, Mónica; Cabanilla, Jaime

2017-10-01

The aim of this study was to evaluate the effect of different sources of variation in gas production technique on the in vitro gas production kinetics of feedstuffs. Triplicates of commercial concentrate, grass silage, grass hay and grass pasture were incubated in three experiments: experiment 1 assessed two agitation methods; experiment 2 evaluated different rumen inocula (pooled or different donor cows for each incubation run); and experiment 3 used Goering-Van Soest or Mould buffers for media preparation. Gas production data were fitted into the Michaelis-Menten model and then subjected to analysis of variance. Gas production (GP) at 48 h and asymptote gas production (A) were lower when bottles were continuously under horizontal movement. Time to produce half and 75% of A, and A were affected by rumen inocula, while buffer type affected time to produce half and 25% of A and GP. No interactions between substrates and sources of variation were observed, suggesting that the effects of substrates on GP parameters were not modified. It is concluded that comparison of numerical data from in vitro experiments that follow different protocols must be done carefully. However, the ranking of different substrates is more robust and less affected by the sources of variation. © 2017 Japanese Society of Animal Science.

Dry reagent dipstick test combined with 23S rRNA PCR for molecular diagnosis of bacterial infection in arthroplasty.

PubMed

Kalogianni, Despina P; Goura, Sophia; Aletras, Alexios J; Christopoulos, Theodore K; Chanos, Michalis G; Christofidou, Myrto; Skoutelis, Athanasios; Ioannou, Penelope C; Panagiotopoulos, Elias

2007-02-15

Periprosthetic joint infections present a challenging problem in orthopaedics. Conventional methods for detection of arthroplasty infections rely on bacterial culture of synovial fluid aspirates. During recent years, however, molecular tests that are based on DNA amplification by the polymerase chain reaction (PCR), followed by electrophoretic analysis of the products, have been introduced. We report a simple and inexpensive assay that allows visual detection and confirmation of the PCR-amplified sequences by hybridization within minutes. The assay is performed in a dry reagent dipstick format (strip) and does not require special instrumentation. Universal primers are used for PCR of the 23S ribosomal RNA (rRNA) gene. The biotinylated amplification product is hybridized with dA-tailed probes that are specific for six pathogens commonly involved in periprosthetic joint infections. The mixture is applied to the strip, which is then immersed in the appropriate buffer. The buffer migrates along the strip by capillary action and rehydrates gold nanoparticles with oligo(dT) strands attached to their surface. The nanoparticles bind to the target DNA through hybridization, and the hybrids are captured by immobilized streptavidin at the test zone of the strip, producing a characteristic red line. Unbound nanoparticles are captured by immobilized oligo(dT) strands at the control zone of the strip, generating a second line. The dipstick test was applied to the detection of Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Enterococcus faesium, and Haemophilus influenza. Twelve samples of synovial fluids from patients were analyzed for the detection and identification of the infection caused by the six pathogens. The results were compared with bacterial cultures.

Grass buffers for playas in agricultural landscapes: An annotated bibliography

USGS Publications Warehouse

Melcher, Cynthia P.; Skagen, Susan K.

2005-01-01

References on best management practices (BMPs) for agricultural lands were included because certain BMPs are crucial for informing decisions about buffer design/ effectiveness and overall playa ecology. We also included various papers that increase the spectrum of time over which buffer theories and practices have evolved. An unannotated section lists references that we did not prioritize for annotation and references that may be helpful but were beyond the scope of this document. Finally, we provide notes on conversations we had with scientists, land managers, and other buffer experts whom we consulted, and their contact information. We conclude the bibliography with appendices of common and scientific names of birds and plants and acronyms used in both the bibliography. In the annotations, italicized text signifies our own editorial remarks. Readers should also note that much of the work on buffers has been designed using English units of measure rather than metrics; in most cases, their results have been converted to metrics for publication, explaining the seemingly odd or irregular buffer widths and other parameters reported.

Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion

Treesearch

Xiaobo Zhou; Matthew J. Helmers; Heidi Asbjornsen; Randy Kolka; Mark D. Tomer

2010-01-01

Many croplands planted to perennial grasses under the Conservation Reserve Program are being returned to crop production, and with potential consequences for water quality. The objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (NO3-N) concentrations in soil and shallow groundwater and to...

ANALYTICAL TOOLS FOR GROUNDWATER POLLUTION ASSESSMENT

EPA Science Inventory

This paper deals with the development of analytical screening-exposure models (indices) and their potential application to regulate the use of hazardous chemicals and the design of groundwater buffer strips. The indices describe the leaching of solutes below the root zone (mass f...

75 FR 4057 - Exelon Generation Company, LLC; PPL Holtwood, LLC; Notice of Application for Amendment of License...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-26

... no project purpose and adding a shoreline buffer strip and a small area inundated by Conowingo Pond... Projects' Boundaries: (1) Exelon and PPL propose removing areas within their projects' boundaries that...

Non-structural carbohydrate partitioning in grass stems: a target to increase yield stability, stress tolerance, and biofuel production.

PubMed

Slewinski, Thomas L

2012-08-01

A dramatic change in agricultural crops is needed in order to keep pace with the demands of an increasing human population, exponential need for renewable fuels, and uncertain climatic changes. Grasses make up the vast majority of agricultural commodities. How these grasses capture, transport, and store carbohydrates underpins all aspects of crop productivity. Sink-source dynamics within the plant direct how much, where, and when carbohydrates are allocated, as well as determine the harvestable tissue. Carbohydrate partitioning can limit the yield capacity of these plants, thus offering a potential target for crop improvement. Grasses have the ability to buffer this sink-source interaction by transiently storing carbohydrates in stem tissue when production from the source is greater than whole-plant demand. These reserves improve yield stability in grain crops by providing an alternative source when photosynthetic capacity is reduced during the later phases of grain filling, or during periods of environmental and biotic stresses. Domesticated grasses such as sugarcane and sweet sorghum have undergone selection for high accumulation of stem carbohydrates, which serve as the primary sources of sugars for human and animal consumption, as well as ethanol production for fuel. With the enormous expectations placed on agricultural production in the near future, research into carbohydrate partitioning in grasses is essential for maintaining and increasing yields in grass crops. This review highlights the current knowledge of non-structural carbohydrate dynamics in grass stems and discusses the impacts of stem reserves in essential agronomic grasses.

Investigating the impact of land cover change on peak river flow in UK upland peat catchments, based on modelled scenarios

NASA Astrophysics Data System (ADS)

Gao, Jihui; Holden, Joseph; Kirkby, Mike

2014-05-01

Changes to land cover can influence the velocity of overland flow. In headwater peatlands, saturation means that overland flow is a dominant source of runoff, particularly during heavy rainfall events. Human modifications in headwater peatlands may include removal of vegetation (e.g. by erosion processes, fire, pollution, overgrazing) or pro-active revegetation of peat with sedges such as Eriophorum or mosses such as Sphagnum. How these modifications affect the river flow, and in particular the flood peak, in headwater peatlands is a key problem for land management. In particular, the impact of the spatial distribution of land cover change (e.g. different locations and sizes of land cover change area) on river flow is not clear. In this presentation a new fully distributed version of TOPMODEL, which represents the effects of distributed land cover change on river discharge, was employed to investigate land cover change impacts in three UK upland peat catchments (Trout Beck in the North Pennines, the Wye in mid-Wales and the East Dart in southwest England). Land cover scenarios with three typical land covers (i.e. Eriophorum, Sphagnum and bare peat) having different surface roughness in upland peatlands were designed for these catchments to investigate land cover impacts on river flow through simulation runs of the distributed model. As a result of hypothesis testing three land cover principles emerged from the work as follows: Principle (1): Well vegetated buffer strips are important for reducing flow peaks. A wider bare peat strip nearer to the river channel gives a higher flow peak and reduces the delay to peak; conversely, a wider buffer strip with higher density vegetation (e.g. Sphagnum) leads to a lower peak and postpones the peak. In both cases, a narrower buffer strip surrounding upstream and downstream channels has a greater effect than a thicker buffer strip just based around the downstream river network. Principle (2): When the area of change is equal, the size of land cover change patches has no effect on river flow for patch sizes up to 40000m2. Principle (3): Bare peat on gentle slopes gives a faster flow response and higher peak value at the catchment outlet, while high density vegetation or re-vegetation on a gentle slope area has larger positive impact on peak river flow delay when compared with the same practices on steeper slopes. These simple principles should be useful to planners who wish to determine resource efficiency and optimisation for peatland protection and restoration works in headwater systems. If practitioners require further detail on impacts of specific spatial changes to land cover in a catchment then this modelling approach can be applied to new catchments of concern.

Provisioning of nestling Dickcissels in native warm-season grass field buffers

USGS Publications Warehouse

Mitchell, K.L.; Riffell, Samuel K.; Burger, L. Wes; Vilella, Francisco

2012-01-01

We used video cameras in 2008–2009 to record provisioning activities at Dickcissel (Spiza americana) nests in and around Conservation Reserve Program field buffers in north-central Mississippi, USA. We simultaneously observed foraging flight distances of parents. Provisioning rate (P  =  0.412), biomass (P  =  0.161), and foraging distance (P  =  0.159) did not increase with nestling age. Parents delivered larger items to meet demand associated with older nestlings (P  =  0.010–0.001). This suggests energetic costs of changes in prey selection were less than costs of increasing the number or distance of provisioning trips. Presence of male helpers increased provisioning rate (P < 0.001) but not biomass (P  =  0.992) because males brought smaller prey items (P  =  0.001–0.021). Presence of observers 30 m from the nest reduced provisioning rates (P  =  0.005) and biomass delivered (P  =  0.066). Lack of habitat effects for any aspect of provisioning suggests grass field buffers provided nestling food resources similar to surrounding habitats. Use of continuous video monitoring of nest activity allows well-concealed activities including provisioning and male helping to be directly observed and better quantified.

7 CFR 1410.6 - Eligible land.

Code of Federal Regulations, 2014 CFR

2014-01-01

... riparian buffer only if, as determined by CCC, it: (A) Is located adjacent to permanent stream corridors excluding corridors that are considered gullies or sod waterways; and (B) Is capable, when permanent grass... vegetation suitable for wetland restoration or wildlife habitat, as determined appropriate by the CCC, of...

7 CFR 1410.6 - Eligible land.

Code of Federal Regulations, 2012 CFR

2012-01-01

... riparian buffer only if, as determined by CCC, it: (A) Is located adjacent to permanent stream corridors excluding corridors that are considered gullies or sod waterways; and (B) Is capable, when permanent grass... vegetation suitable for wetland restoration or wildlife habitat, as determined appropriate by the CCC, of...

7 CFR 1410.6 - Eligible land.

Code of Federal Regulations, 2013 CFR

2013-01-01

... riparian buffer only if, as determined by CCC, it: (A) Is located adjacent to permanent stream corridors excluding corridors that are considered gullies or sod waterways; and (B) Is capable, when permanent grass... vegetation suitable for wetland restoration or wildlife habitat, as determined appropriate by the CCC, of...

Riparian Sediment Delivery Ratio: Stiff Diagrams and Artifical Neural Networks

EPA Science Inventory

Various methods are used to estimate sediment transport through riparian buffers and grass jilters with the sediment delivery ratio having been the most widely applied. The U.S. Forest Service developed a sediment delivery ratio using the stiff diagram and a logistic curve to int...

Water quality impact assessment of agricultural Beneficial Management Practices (BMPs) simulated for a regional catchment in Quebec, Eastern Canada

NASA Astrophysics Data System (ADS)

Rousseau, Alain N.; Hallema, Dennis W.; Gumiere, Silvio J.; Savary, Stéphane; Hould Gosselin, Gabriel

2014-05-01

Water quality has become a matter of increasing concern over the past four decades as a result of the intensification of agriculture, and more particularly so in Canada where agriculture has evolved into the largest non-point source of surface water pollution. The Canadian WEBs project (Watershed Evaluation of Beneficial Management Practices, BMPs) was initiated in order to determine the efficiency of BMPs in improving the surface water quality of rural catchments, and the economic aspects related to their implementation on the same scale. In this contribution we use the integrated watershed modelling platform GIBSI (Gestion Intégrée des Bassins versants à l'aide d'un Système Informatisé) to evaluate the effects of various BMPs on sediment and nutrient yields and, in close relation to this, the surface water quality for the Beaurivage River catchment (718 km2) in Quebec, eastern Canada. A base scenario of the catchment is developed by calibrating the different models of the GIBSI platform, namely HYDROTEL for hydrology, the Revised Universal Soil Loss Equation (RUSLE) for soil erosion, the Erosion-Productivity Impact Calculator (EPIC) of the Soil and Water Assessment Tool (SWAT) for contaminant transport and fate, and QUAL2E for stream water quality. Four BMPs were analysed: (1) vegetated riparian buffer strips, (2) precision slurry application, (3) transition of all cereal and corn fields to grassland (grassland conversion), and (4) no-tillage on corn fields. Simulations suggest that riparian buffer strips and grassland conversion are more effective in terms of phosphorus, nitrogen and sediment load reduction than precision slurry application and no-tillage on corn fields. The results furthermore indicate the need for a more profound understanding of sediment dynamics in streams and on riparian buffer strips.

Phosphorus mitigation during springtime runoff by amendments applied to grassed soil.

PubMed

Uusi-Kämppä, J; Turtola, E; Närvänen, A; Jauhiainen, L; Uusitalo, R

2012-01-01

Permanent grass vegetation on sloping soils is an option to protect fields from erosion, but decaying grass may liberate considerable amounts of dissolved reactive P (DRP) in springtime runoff. We studied the effects of freezing and thawing of grassed soil on surface runoff P concentrations by indoor rainfall simulations and tested whether the peak P concentrations could be reduced by amending the soil with P-binding materials containing Ca or Fe. Forty grass-vegetated soil blocks (surface area 0.045 m, depth 0.07 m) were retrieved from two permanent buffer zones on a clay and loam soil in southwest Finland. Four replicates were amended with either: (i) gypsum from phosphoric acid processing (CaSO × 2HO, 6 t ha), (ii) chalk powder (CaCO, 3.3 t ha), (iii) Fe-gypsum (6 t ha) from TiO processing, or (iv) granulated ferric sulfate (Fe[SO], 0.7 t ha), with four replicates serving as untreated controls. Rainfall (3.3 h × 5 mm h) was applied on presaturated samples set at a slope of 5% and the surface runoff was analyzed for DRP, total dissolved P (TDP), total P (TP), and suspended solids. Rainfall simulation was repeated twice after the samples were frozen. Freezing and thawing of the samples increased the surface runoff DRP concentration of the control treatment from 0.19 to 0.46 mg L, up to 2.6-3.7 mg L, with DRP being the main P form in surface runoff. Compared with the controls, surface runoff from soils amended with Fe compounds had 57 to 80% and 47 to 72% lower concentrations of DRP and TP, respectively, but the gypsum and chalk powder did not affect the P concentrations. Thus, amendments containing Fe might be an option to improve DRP retention in, e.g., buffer zones. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Microhabitats and canopy cover moderate high summer temperatures in a fragmented Mediterranean landscape.

PubMed

Keppel, Gunnar; Anderson, Sharolyn; Williams, Craig; Kleindorfer, Sonia; O'Connell, Christopher

2017-01-01

Extreme heat events will become more frequent under anthropogenic climate change, especially in Mediterranean ecosystems. Microhabitats can considerably moderate (buffer) the effects of extreme weather events and hence facilitate the persistence of some components of the biodiversity. We investigate the microclimatic moderation provided by two important microhabitats (cavities formed by the leaves of the grass-tree Xanthorrhoea semiplana F.Muell., Xanthorrhoeaceae; and inside the leaf-litter) during the summer of 2015/16 on the Fleurieu Peninsula of South Australia. We placed microsensors inside and outside these microhabitats, as well as above the ground below the forest canopy. Grass-tree and leaf-litter microhabitats significantly buffered against high temperatures and low relative humidity, compared to ground-below-canopy sensors. There was no significant difference between grass-tree and leaf-litter temperatures: in both microhabitats, daily temperature variation was reduced, day temperatures were 1-5°C cooler, night temperatures were 0.5-3°C warmer, and maximum temperatures were up to 14.4°C lower, compared to ground-below-canopy sensors. Grass-tree and leaf-litter microhabitats moderated heat increase at an average rate of 0.24°C temperature per 1°C increase of ambient temperature in the ground-below-canopy microhabitat. The average daily variation in temperature was determined by the type (grass-tree and leaf-litter versus ground-below-canopy) of microhabitat (explaining 67%), the amount of canopy cover and the area of the vegetation fragment (together explaining almost 10% of the variation). Greater canopy cover increased the amount of microclimatic moderation provided, especially in the leaf-litter. Our study highlights the importance of microhabitats in moderating macroclimatic conditions. However, this moderating effect is currently not considered in species distribution modelling under anthropogenic climate change nor in the management of vegetation. This shortcoming will have to be addressed to obtain realistic forecasts of future species distributions and to achieve effective management of biodiversity.

IMPROVING HYDROLOGIC SUSTAINABILITY OF TEXAS A&M UNIVERSITY CAMPUS

EPA Science Inventory

For small to mid-sized rain events, LID scenarios, including permeable pavements, rainwater harvesting, green roofs, and riparian buffer strips perform similarly to a conventional Best Management Practice, a detention pond, with respect to peak flows and HFR. For large rain ev...

EVALUATION OF MEASURES FOR CONTROLLING SEDIMENT AND NUTRIENT LOSSES FROM IRRIGATED AREAS

EPA Science Inventory

Field studies were conducted in two southern Idaho areas to determine the effects of different management practices on the quality and quantity of the runoff from surface-irrigated fields. Pollutant removal systems (primarily mini-basins, vegetated buffer strips and sediment rete...

Introduction of atrazine degrader to enhance rhizodegradation of atrazine

USDA-ARS?s Scientific Manuscript database

Introducing atrazine (ATR) degraders into riparian vegetative buffer strips (VBS) can be a promising bioremediation approach to accelerate the degradation of ATR and its degradation products deposited into VBS by surface runoff. A growth chamber study was conducted to investigated the synergistic ef...

Assessment and placement of living snow fences to reduce highway maintenance costs and improve safety (living snow fences).

DOT National Transportation Integrated Search

2015-05-01

Living snow fences (LSF) are designed plantings of trees and/or shrubs and native grasses along highways, roads : and ditches that create a vegetative buffer that traps and controls blowing and drifting snow. These strategically : placed fences have ...

Plant Growth and Phosphorus Uptake of Three Riparian Grass Species

USDA-ARS?s Scientific Manuscript database

Riparian buffers can significantly reduce sediment-bound phosphorus (P) entering surface water, but control of dissolved P inputs is more challenging. Because plant roots remove P from soil solution, it follows that plant uptake will reduce dissolved P losses. We evaluated P uptake of smooth bromegr...

Sidewalk Landscape Structure and Thermal Conditions for Child and Adult Pedestrians

PubMed Central

Kim, Young-Jae; Lee, Chanam; Kim, Jun-Hyun

2018-01-01

Walking is being promoted for health and transportation purposes across all climatic regions in the US and beyond. Despite this, an uncomfortable microclimate condition along sidewalks is one of the major deterrents of walking, and more empirical research is needed to determine the risks of heat exposure to pedestrians while walking. This study examined the effect of street trees and grass along sidewalks on air temperatures. A series of thermal images were taken at the average heights of adults and children in the US to objectively measure the air temperatures of 10 sidewalk segments in College Station, TX, USA. After controlling the other key physical environmental conditions, sidewalks with more trees or wider grass buffer areas had lower air temperatures than those with less vegetation. Children were exposed to higher temperatures due to the greater exposure or proximity to the pavement surface, which tends to have higher radiant heat. Multivariate regression analysis suggested that the configuration of trees and grass buffers along the sidewalks helped to promote pleasant thermal conditions and reduced the differences in ambient air temperatures measured at child and adult heights. This study suggests that street trees and vegetated ground help reduce the air temperatures, leading to more thermally comfortable environments for both child and adult pedestrians in warm climates. The thermal implications of street landscape require further attention by researchers and policy makers that are interested in promoting outdoor walking. PMID:29346312

Evaluating agricultural nonpoint-source pollution using integrated geographic information systems and hydrologic/water quality model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tim, U.S.; Jolly, R.

1994-01-01

Considerable progress has been made in developing physically based, distributed parameter, hydrologic/water quality (HIWQ) models for planning and control of nonpoint-source pollution. The widespread use of these models is often constrained by the excessive and time-consuming input data demands and the lack of computing efficiencies necessary for iterative simulation of alternative management strategies. Recent developments in geographic information systems (GIS) provide techniques for handling large amounts of spatial data for modeling nonpoint-source pollution problems. Because a GIS can be used to combine information from several sources to form an array of model input data and to examine any combinations ofmore » spatial input/output data, it represents a highly effective tool for HiWQ modeling. This paper describes the integration of a distributed-parameter model (AGNPS) with a GIS (ARC/INFO) to examine nonpoint sources of pollution in an agricultural watershed. The ARC/INFO GIS provided the tools to generate and spatially organize the disparate data to support modeling, while the AGNPS model was used to predict several water quality variables including soil erosion and sedimentation within a watershed. The integrated system was used to evaluate the effectiveness of several alternative management strategies in reducing sediment pollution in a 417-ha watershed located in southern Iowa. The implementation of vegetative filter strips and contour buffer (grass) strips resulted in a 41 and 47% reduction in sediment yield at the watershed outlet, respectively. In addition, when the integrated system was used, the combination of the above management strategies resulted in a 71% reduction in sediment yield. In general, the study demonstrated the utility of integrating a simulation model with GIS for nonpoini-source pollution control and planning. Such techniques can help characterize the diffuse sources of pollution at the landscape level. 52 refs., 6 figs., 1 tab.« less

Analysis of the efficacy and cost-effectiveness of best management practices for controlling sediment yield: A case study of the Joumine watershed, Tunisia.

PubMed

Mtibaa, Slim; Hotta, Norifumi; Irie, Mitsuteru

2018-03-01

Soil erosion can be reduced through the strategic selection and placement of best management practices (BMPs) in critical source areas (CSAs). In the present study, the Soil Water Assessment Tool (SWAT) model was used to identify CSAs and investigate the effectiveness of different BMPs in reducing sediment yield in the Joumine watershed, an agricultural river catchment located in northern Tunisia. A cost-benefit analysis (CBA) was used to evaluate the cost-effectiveness of different BMP scenarios. The objective of the present study was to determine the most cost-effective management scenario for controlling sediment yield. The model performance for the simulation of streamflow and sediment yield at the outlet of the Joumine watershed was good and satisfactory, respectively. The model indicated that most of the sediment was originated from the cultivated upland area. About 34% of the catchment area consisted of CSAs that were affected by high to very high soil erosion risk (sediment yield >10t/ha/year). Contour ridges were found to be the most effective individual BMP in terms of sediment yield reduction. At the watershed level, implementing contour ridges in the CSAs reduced sediment yield by 59%. Combinations of BMP scenarios were more cost-effective than the contour ridges alone. Combining buffer strips (5-m width) with other BMPs depending on land slope (> 20% slope: conversion to olive orchards; 10-20% slope: contour ridges; 5-10% slope: grass strip cropping) was the most effective approach in terms of sediment yield reduction and economic benefits. This approach reduced sediment yield by 61.84% with a benefit/cost ratio of 1.61. Compared with the cost of dredging, BMPs were more cost-effective for reducing sediment loads to the Joumine reservoir, located downstream of the catchment. Our findings may contribute to ensure the sustainability of future conservation programs in Tunisian regions. Copyright © 2017 Elsevier B.V. All rights reserved.

Ecotype-specific improvement of nitrogen status in European grasses after drought combined with rewetting

NASA Astrophysics Data System (ADS)

Arfin Khan, Mohammed A. S.; Kreyling, Juergen; Beierkuhnlein, Carl; Jentsch, Anke

2016-11-01

Drought stress and associated low soil moisture can decrease N status of forage plants by reducing nitrogen (N) uptake. Conversely, rainfall and associated favorable soil moisture can improve plant N status. Yet, it is unclear to which degree drought combined with rewetting can buffer negative effects of drought on N status of forage plants and their populations. Here, we compared shoot N status (N concentration, total N uptake and C/N ratio) of four temperate grass species. Particularly, we investigated ecotypes (populations) grown from seeds from four to six European provenances/species after a drought treatment combined with rewetting (10 day harvest delay) versus continuously watered conditions for control. The experimental combination of drought and rewetting significantly increased shoot N concentration (+96%), N uptake (+31%); and decreased C/N ratio (-46%), biomass production (-29%) and C concentration (-1.4%) compared to control. Shoot N status was found to be different between target grass species and also within their populations under drought combined with rewetting treatment. Presumably drought-adapted populations did not perform better than populations from moist sites indicating no evidence of local adaptation. The drought combined with rewetting event could buffer the negative effects of drought. Shoot N status of grasses after drought and rewetting even exceeded control plants. This surprising finding can potentially be explained by higher N uptake, lack of growth dilution effects or delayed plant maturation. Furthermore, within-species shoot N status responses to drought combined with rewetting event were ecotype-specific, hinting at diverse responses of different population. For rangeland management, we recommend that if a drought event occurs during the growing season, harvesting should be delayed beyond a following rain event.

Improving Water Quality With Conservation Buffers

NASA Astrophysics Data System (ADS)

Lowrance, R.; Dabney, S.; Schultz, R.

2003-12-01

Conservation buffer technologies are new approaches that need wider application. In-field buffer practices work best when used in combination with other buffer types and other conservation practices. Vegetative barriers may be used in combination with edge-of-field buffers to protect and improve their function and longevity by dispersing runoff and encouraging sediment deposition upslope of the buffer. It's important to understand how buffers can be managed to help reduce nutrient transport potential for high loading of nutrients from manure land application sites, A restored riparian wetland buffer retained or removed at least 59 percent of the nitrogen and 66 percent of the phosphorus that entered from an adjacent manure land application site. The Bear Creek National Restoration Demonstration Watershed project in Iowa has been the site of riparian forest buffers and filter strips creation; constructed wetlands to capture tile flow; stream-bank bioengineering; in-stream structures; and controlling livestock grazing. We need field studies that test various widths of buffers of different plant community compositions for their efficacy in trapping surface runoff, reducing nonpoint source pollutants in subsurface waters, and enhancing the aquatic ecosystem. Research is needed to evaluate the impact of different riparian grazing strategies on channel morphology, water quality, and the fate of livestock-associated pathogens and antibiotics. Integrating riparian buffers and other conservation buffers into these models is a key objective in future model development.

Airphoto analysis of erosion control practices

NASA Technical Reports Server (NTRS)

Morgan, K. M.; Morris-Jones, D. R.; Lee, G. B.; Kiefer, R. W.

1980-01-01

The Universal Soil Loss Equation (USLE) is a widely accepted tool for erosion prediction and conservation planning. In this study, airphoto analysis of color and color infrared 70 mm photography at a scale of 1:60,000 was used to determine the erosion control practice factor in the USLE. Information about contour tillage, contour strip cropping, and grass waterways was obtained from aerial photography for Pheasant Branch Creek watershed in Dane County, Wisconsin.

Co-digestion of manure with grass silage and pulp and paper mill sludge using nutrient additions.

PubMed

Hagelqvist, Alina; Granström, Karin

2016-08-01

There is an increasing worldwide demand for biogas. Anaerobic co-digestion involves the treatment of different substrates with the aim of improving the production of biogas and the stability of the process. This study evaluates how methane production is affected by the co-digestion of pig and dairy manure with grass silage and pulp and paper mill sludge and assesses whether methane production is affected by factors other than nutrient deficiency, low buffering capacity, inadequate dilution, and an insufficient activity and amount of microorganism culture. Anaerobic digestion was performed in batch reactors under mesophilic conditions for 20 days. The season of grass silage and manure collection proved to be an important factor affecting methane production. Spring grass silage produced a maximum of 250 mL/VSadded and spring manure 150 mL/VSadded, whereas autumn grass silage produced at most 140 ml/VSadded and autumn manure 45 mL/VSadded. The pulp mill sludge used is comprised of both primary and secondary sludge and produced at most 50 mL/VSadded regardless of season; this substrate benefitted most from co-digestion.

Allelopathic cover crop prior to seeding is more important than subsequent grazing/mowing in grassland establishment

USGS Publications Warehouse

Milchunas, Daniel G.; Vandever, Mark W.; Ball, Leonard O.; Hyberg, Skip

2011-01-01

The effects of grazing, mowing, and type of cover crop were evaluated in a previous winter wheat–fallow cropland seeded to grassland under the Conservation Reserve Program in eastern Colorado. Prior to seeding, the fallow strips were planted to forage sorghum or wheat in alternating strips (cover crops), with no grazing, moderate to heavy grazing, and mowing (grazing treatments) superimposed 4 yr after planting and studied for 3 yr. Plots previously in wheat had more annual and exotic species than sorghum plots. Concomitantly, there were much greater abundances of perennial native grass and all native species in sorghum than wheat cropped areas. The competitive advantage gained by seeded species in sorghum plots resulted in large increases in rhizomatous western wheatgrass. Sorghum is known to be allelopathic and is used in crop agriculture rotations to suppress weeds and increase crop yields, consistent with the responses of weed and desired native species in this study. Grazing treatment had relatively minor effects on basal and canopy cover composition of annual or exotic species versus perennial native grass or native species. Although grazing treatment never was a significant main effect, it occasionally modified cover crop or year effects. Opportunistic grazing reduced exotic cheatgrass by year 3 but also decreased the native palatable western wheatgrass. Mowing was a less effective weed control practice than grazing. Vegetative basal cover and aboveground primary production varied primarily with year. Common management practices for revegetation/restoration currently use herbicides and mowing as weed control practices and restrict grazing in all stages of development. Results suggest that allelopathic cover crop selection and opportunistic grazing can be effective alternative grass establishment and weed control practices. Susceptibility, resistance, and interactions of weed and seeded species to allelopathic cover species/cultivars may be a fruitful area of research.

Isolation and partial purification of cadmium-binding protein from roots of the grass Agrostis gigantea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rauser, W.E.

1984-04-01

A cadmium-binding protein was isolated from roots of the grass Agrostis gigantea Roth. Heat-stable proteins were chromatographed on the anion exchanger QAE-Sephadex A-25. The major cadmium fraction was purified further by gel filtration of Sephadex G-75 in 1 molar KCI buffer. The resulting protein preparation was light brown, had an apparent molecular weight of 3700, contained 29% cysteine and close to 4 gram atoms cadmium/mole. The cadmium:cysteine ratio was l:2.7. Spectroscopic measurments indicated cadmium-thiolate coordination. The roots produced the metallothionein-like protein when they were exposed to cadmium for 7 days.

CONSTRUCTED WETLANDS IN SUPPORT OF RIPARIAN RESTORATION: WATER QUALITY BENEFITS AND HABITAT RESTORATION IN DELAWARE AGRICULTURAL AREAS

EPA Science Inventory

Surface water runoff from agricultural landscapes is one of the major sources of water quality impairment in the United States. With the advent of buffer strips and conservation minded tilling practices the agricultural community has made significant reductions in overland runof...

7 CFR 1410.7 - Duration of contracts.

Code of Federal Regulations, 2014 CFR

2014-01-01

... of contracts. (a) Except as provided in paragraphs (b) or (c) of this section, contracts under this part shall be for a term of 10 years. (b) In the case of land devoted to riparian buffers, filter strips, restoration of wetlands, hardwood trees, shelterbelts, windbreaks, wildlife corridors, or other...

7 CFR 1410.7 - Duration of contracts.

Code of Federal Regulations, 2011 CFR

2011-01-01

... of contracts. (a) Except as provided in paragraphs (b) or (c) of this section, contracts under this part shall be for a term of 10 years. (b) In the case of land devoted to riparian buffers, filter strips, restoration of wetlands, hardwood trees, shelterbelts, windbreaks, wildlife corridors, or other...

7 CFR 1410.7 - Duration of contracts.

Code of Federal Regulations, 2012 CFR

2012-01-01

... of contracts. (a) Except as provided in paragraphs (b) or (c) of this section, contracts under this part shall be for a term of 10 years. (b) In the case of land devoted to riparian buffers, filter strips, restoration of wetlands, hardwood trees, shelterbelts, windbreaks, wildlife corridors, or other...

7 CFR 1410.7 - Duration of contracts.

Code of Federal Regulations, 2013 CFR

2013-01-01

... of contracts. (a) Except as provided in paragraphs (b) or (c) of this section, contracts under this part shall be for a term of 10 years. (b) In the case of land devoted to riparian buffers, filter strips, restoration of wetlands, hardwood trees, shelterbelts, windbreaks, wildlife corridors, or other...

MEDUSA-32: A low noise, low power silicon strip detector front-end electronics, for space applications

NASA Astrophysics Data System (ADS)

Cicuttin, Andres; Colavita, Alberto; Cerdeira, Alberto; Fratnik, Fabio; Vacchi, Andrea

1997-02-01

In this report we describe a mixed analog-digital integrated circuit (IC) designed as the front-end electronics for silicon strip-detectors for space applications. In space power consumption, compactness and robustness become critical constraints for a pre-amplifier design. The IC is a prototype with 32 complete channels, and it is intended for a large area particle tracker of a new generation of gamma ray telescopes. Each channel contains a charge sensitive amplifier, a pulse shaper, a discriminator and two digital buffers. The reference trip point of the discriminator is adjustable. This chip also has a custom PMOSFET transistor per channel, included in order to provide the high dynamic resistance needed to reverse-bias the strip diode. The digital part of the chip is used to store and serially shift out the state of the channels. There is also a storage buffer that allows the disabling of non-functioning channels if it is required by the data acquisition system. An input capacitance of 30 pF introduced at the input of the front-end produces less than 1000 electrons of RMS equivalent noise charge (ENC), for a total power dissipation of only 60 μW per channel. The chip was made using Orbit's 1.2 μm double poly, double metal n-well low noise CMOS process. The dimensions of the IC are 2400 μm × 8840 μm.

Multiplexed displacement fiber sensor using thin core fiber exciter.

PubMed

Chen, Zhen; Hefferman, Gerald; Wei, Tao

2015-06-01

This letter reports a multiplexed optical displacement sensor using a thin core fiber (TCF) exciter. The TCF exciter is followed by a stripped single mode optical fiber. A small section of buffer is used as the movable component along the single mode fiber. Ultra-weak cladding mode reflection (< - 75 dB) was employed to probe the refractive index discontinuity between the air and buffer coating boundary. The position change of the movable buffer segment results in a delay change of the cladding mode reflection. Thus, it is a measure of the displacement of the buffer segment with respect to the glass fiber. The insertion loss of one sensor was measured to be less than 3 dB. A linear relationship was evaluated between the measurement position and absolute position of the moving actuator. Multiplexed capability was demonstrated and no cross talk was found between the sensors.

An evaluation of the use of individual grass species in retaining polluted soil and dust particulates in vegetated sustainable drainage devices.

PubMed

Charlesworth, S M; Bennett, J; Waite, A

2016-08-01

A sustainable means of preventing polluted particulates carried in urban storm water entering rivers, groundwater and lakes is by employing vegetated sustainable drainage system (SUDS) devices, or best management practices to trap or biodegrade them. In the UK, a mixture of grass species is recommended for use in devices such as swales or filter strips. However, there is little evidence in support of the efficiency of the individual grasses or mixtures to deal with such contaminated material. A pot-based pollutant retention study was conducted using processed street dust from central Coventry, UK, as a simulated pollutant to be applied in different quantities to a variety of recommended grasses for vegetated SUDS devices. Analysis was conducted on compost cores, roots and shoots for heavy metals (Cd, Cu, Ni, Pb and Zn). Street dust mainly concentrated in the top compost layer for all grasses with only the finer material migrating down the profile. Analysis of roots indicated little accumulation, with ANOVA statistical tests indicating significant differences in heavy metal concentrations, with less in the compost and more in the shoots. Development of root systems on or near the surface possibly explains increased uptake of heavy metals by some species. Overall Agrostis canina and Poa pratensis showed the greatest accumulations compared to their controls although Agrostis capillaris syn.tenuis and Agrostis stolonifera also demonstrated accumulation potential. On ranking, Agrostis canina and Poa pratensis were highest overall. These rankings will assist in selecting the best grasses to address pollution of the urban environment by contaminated particulates.

Monitoring Liverworts to Evaluate the Effectiveness of Hydroriparian Buffers

NASA Astrophysics Data System (ADS)

Higgins, Kellina L.; Yasué, Maï

2014-01-01

In the coastal temperate rainforest of British Columbia (BC) in western Canada, government policies stipulate that foresters leave unlogged hydroriparian buffer strips up to 25 m on each side of streams to protect wildlife habitat. At present, studies on the effectiveness of these buffers focus on mammals, birds, and amphibians while there is comparably little information on smaller organisms such as liverworts in these hydroriparian buffers. To address this gap of knowledge, we conducted field surveys of liverworts comparing the percent cover and community composition in hydroriparian forested areas ( n = 4 sites, n = 32 plots with nested design) to hydroriparian buffer zones ( n = 4 sites, n = 32 plots). We also examined how substrate type affected the cover of liverworts. Liverwort communities in buffers were similar to those in riparian forest areas and most liverworts were found on downed wood. Thus, hydroriparian buffers of 25-35 m on each side in a coastal temperate rainforest effectively provide habitat for liverworts as long as downed wood is left intact in the landscape. Because liverworts are particularly sensitive to changes in humidity, these results may indicate that hydroriparian buffers are an effective management strategy for bryophytes and possibly for a range of other riparian species that are particularly sensitive to forestry-related changes in microclimate.

EnviroAtlas - Paterson, NJ - 51m Riparian Buffer Vegetated Cover

EPA Pesticide Factsheets

This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. EnviroAtlas defines vegetated buffer for this community as trees and forest and grass and herbaceous. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

Long-term assessment of runoff and sediment transport from grass and agroforestry buffers in corn/soybean watersheds using APEX

USDA-ARS?s Scientific Manuscript database

Existence of a claypan layer in soils at depths ranging from 4 to 37 cm restricts water movement and has contributed significantly to high rates of runoff, sediment transport, and other non-point source loadings from croplands in watersheds. The deposition of these pollutants in rivers, streams and...

Circular buffer strips in center pivot irrigation for multiple benefits in the Southern Great Plains

USDA-ARS?s Scientific Manuscript database

The Ogallala Aquifer has converted the Southern Great Plains from a dust bowl to a highly productive agricultural region in the US. However, over exploitation of the aquifer is threatening sustainability of irrigated agriculture in the region. Partial pivots, where high water using conventional crop...

Linked in: connecting riparian areas to support forest biodiversity

Treesearch

Marie Oliver; Kelly Burnett; Deanna Olson

2010-01-01

Many forest-dwelling species rely on both terrestrial and aquatic habitat for their survival. These species, including rare and little-understood amphibians and arthropods, live in and around headwater streams and disperse overland to neighboring headwater streams. Forest management policies that rely on riparian buffer strips and structurebased management—practices...

Utiliizing Vegetative Buffer Strips to Remove Dissolved and Sediment-Bound Herbicides from Surface Water Runoff

USDA-ARS?s Scientific Manuscript database

Current federal and state soil and water conservation programs consist primarily of cost-sharing or compensating farmers for implementing a set of pre-defined best management practices which do not consider specific environmental outcomes or cost-effectiveness of the program at the farm or watershed...

Stress intensity factors of composite orthotropic plates containing periodic buffer strips

NASA Technical Reports Server (NTRS)

Delale, F.; Erdogan, F.

1978-01-01

The fracture problem of laminated plates which consist of bonded orthotropic layers is studied. The fields equations for an elastic orthotropic body are transformed to give the displacement and stress expressions for each layer or strip. The unknown functions in these expressions are found by satisfying the remaining boundary and continuity conditions. A system of singular integral equations is obtained from the mixed boundary conditions. The singular behavior around the crack tip and at the bimaterial interface is studied. The stress intensity factors are computed for various material combinations and various crack geometries. The results are discussed and are compared with those for isotropic materials.

Anodic stripping voltammetry of nickel ions and nickel hydroxide nanoparticles at boron-doped diamond electrodes

NASA Astrophysics Data System (ADS)

Musyarofah, N. R. R.; Gunlazuardi, J.; Einaga, Y.; Ivandini, T. A.

2017-04-01

Anodic stripping voltammetry (ASV) of nickel ions in phosphate buffer solution (PBS) have been investigated at boron-doped diamond (BDD) electrodes. The deposition potential at 0.1 V (vs. Ag/AgCl) for 300 s in 0.1 M PBS pH 3 was found as the optimum condition. The condition was applied for the determination of nickel contained in nickel hydroxide nanoparticles. A linear calibration curve can be achieved of Ni(OH)2-NPs in the concentration range of x to x mM with an estimated limit of detection (LOD) of 5.73 × 10-6 mol/L.

Use of black soldier fly larvae (Hermetia illucens) to substitute soybean meal in ruminant diet: An in vitro rumen fermentation study

PubMed Central

Jayanegara, Anuraga; Novandri, Briliannanda; Yantina, Nover; Ridla, Muhammad

2017-01-01

Aim: This experiment aimed to evaluate substitution of soybean meal (SBM) by black soldier fly (BSF) larvae meal in a napier grass diet as performed by an in vitro rumen fermentation system. Materials and Methods: Samples of napier grass, SBM, and BSF larvae age 1 week (BSF1) and 2 weeks (BSF2) were arranged according to the following dietary treatments (dry matter [DM] basis): T1, 100% napier grass; T2, 60% napier grass + 40% SBM; T3, 60% napier grass + 40% BSF1; T4, 60% napier grass + 40% BSF2; T5, 60% napier grass + 20% SBM + 20% BSF1; and T6, 60% napier grass + 20% SBM + 20% BSF2. The samples were determined for their chemical composition and were incubated in vitro using buffered rumen fluid for 48 h at 39°C. In vitro incubation was carried out in three runs and represented by two incubation bottles per run. Results: Supplementation of BSF, both BSF1 and BSF2, increased ether extract, neutral- and acid-detergent insoluble crude protein contents of T3-T6 diets. The T3 or T4 diet resulted in lower ruminal ammonia concentration, in vitro DM digestibility, and in vitro organic matter (OM) digestibility as compared to those in T2 (p<0.05). Diet supplemented with BSF produced lower methane emission in comparison to that of supplemented with SBM (p<0.05). Diet containing BSF2 produced lower methane and methane per digestible OM than that containing BSF1 (p<0.05). Conclusion: Substitution of SBM by BSF in ruminant diet results in a lower nutritional value in vitro but with an advantage of lowering ruminal methane emission. PMID:29391684

EnviroAtlas - New York, NY - One Meter Resolution Urban Land Cover Data (2008)

EPA Pesticide Factsheets

The New York, NY EnviroAtlas Meter-scale Urban Land Cover (MULC) Data were generated by the University of Vermont Spatial Analysis Laboratory (SAL) under the direction of Jarlath O'Neil-Dunne as part of the United States Forest Service Urban Tree Canopy (UTC) assessment program. Seven classes were mapped using LiDAR and high resolution orthophotography: Tree Canopy, Grass/Shrub, Bare Soil, Water, Buildings, Roads/Railroads, and Other Paved Surfaces. These data were subsequently merged to fit with the EPA classification. The SAL project covered the five boroughs within the NYC city limits. However the EPA study area encompassed that area plus a 1 kilometer buffer. Additional land cover for the buffer area was generated from United States Department of Agriculture (USDA) National Agricultural Imagery Program (NAIP) four band (red, green, blue, and near infrared) aerial photography at 1 m spatial resolution from July, 2011 and LiDAR from 2010. Six land cover classes were mapped: water, impervious surfaces, soil and barren land, trees, grass-herbaceous non-woody vegetation, and agriculture. An accuracy assessment of 600 completely random and 55 stratified random photo interpreted reference points yielded an overall User's fuzzy accuracy of 87 percent. The area mapped is the US Census Bureau's 2010 Urban Statistical Area for New York City plus a 1 km buffer. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAt

Impact of rainfall intensity on the transport of two herbicides in undisturbed grassed filter strip soil cores

NASA Astrophysics Data System (ADS)

Pot, V.; Šimůnek, J.; Benoit, P.; Coquet, Y.; Yra, A.; Martínez-Cordón, M.-J.

2005-12-01

Two series of displacement experiments with isoproturon and metribuzin herbicides were performed on two undisturbed grassed filter strip soil cores, under unsaturated steady-state flow conditions. Several rainfall intensities (0.070, 0.147, 0.161, 0.308 and 0.326 cm h - 1 ) were used. A water tracer (bromide) was simultaneously injected in each displacement experiment. A descriptive analysis of experimental breakthrough curves of bromide and herbicides combined with a modeling analysis showed an impact of rainfall intensity on the solute transport. Two contrasting physical non-equilibrium transport processes occurred. Multiple (three) porosity domains contributed to flow at the highest rainfall intensities, including preferential flow through macropore pathways. Macropores were not active any longer at intermediate and lowest velocities, and the observed preferential transport was described using dual-porosity-type models with a zero or low flow in the matrix domain. Chemical non-equilibrium transport of herbicides was found at all rainfall intensities. Significantly higher estimated values of degradation rate parameters as compared to batch data were correlated with the degree of non-equilibrium sorption. Experimental breakthrough curves were analyzed using different physical and chemical equilibrium and non-equilibrium transport models: convective-dispersive model (CDE), dual-porosity model (MIM), dual-permeability model (DP), triple-porosity, dual permeability model (DP-MIM); each combined with both chemical instantaneous and kinetic sorption.

Voltammetric determination of In3+ based on the bifunctionality of a multi-walled carbon nanotubes-nafion modified electrode.

PubMed

Li, Junhua; Zhang, Fuxing; Wang, Jianqiu; Xu, Zhifeng; Zeng, Rongying

2009-05-01

Due to the strong cation-exchange ability of Nafion and the excellent properties of multi-walled carbon nanotubes (MWCNTs), a highly sensitive and mercury-free method of determining trace levels of In(3+) has been established based on the bifunctionality of a MWCNTs/Nafion modified glassy carbon electrode (GCE). The MWCNTs/Nafion modified GCE detects In(3+) in a 0.01 M HAc-NaAc buffer solution at pH 5.0 using anodic stripping voltammetry (ASV). The experimental results suggest that a sensitive anodic stripping peak appears at -0.58 V on anodic stripping voltammograms, which can be used as an analytical signal for the determination of In(3+). A good linear relationship between the stripping peak currents and the In(3+) concentration is obtained, covering the concentration range from 5.0 x 10(-10) to 2.0 x 10(-7) M, with a correlation coefficient of 0.999; the detection limit is 1.0 x 10(-11) M. This proposed method has been applied to detect In(3+) as a new way.

Assessing benefits and risk of using flue gas desulfurized gypsum (FGDG) as soil amendment in a Coastal Plain soil

USDA-ARS?s Scientific Manuscript database

The influence of FGDG and grass buffers on runoff water quality and corn production following poultry litter (PL) application is being evaluated as part of a regional USDA-ARS project (Auburn-AL, Oxford-MS, and Tifton-GA). Treatments at Tifton were laid out in a randomized complete block design wit...

ArcAPEX modeling of optimum widths and placement of grass and agroforestry buffers to reduce runoff and sediment transport in claypan watersheds

USDA-ARS?s Scientific Manuscript database

Existence of a claypan layer in soils at depths ranging from 4 to 37 cm restricts vertical water movement and has contributed significantly to high rates of runoff, sediment transport, and other non-point source loadings from croplands in watersheds. The deposition of these pollutants in rivers, st...

Watershed scale assessment of the impact of forested riparian zones on stream water quality

Treesearch

J. A. Webber; K. W. J. Williard; M. R. Whiles; M. L. Stone; J. J. Zaczek; D. K. Davie

2003-01-01

Federal and state land management agencies have been promoting forest and grass riparian zones to combat non-point source nutrient and sediment pollution of our nations' waters. The majority of research examining the effectiveness of riparian buffers at reducing nutrient and sediment inputs to streams has been conducted at the field scale. This study took a...

Circles of live buffer strips in a center pivot to improve multiple ecosystem services and sustainability of irrigated agriculture in the southern great plains

USDA-ARS?s Scientific Manuscript database

Declining Ogallala Aquifer has threatened sustainability of highly productive irrigated agriculture in the region. The region, known for the dust bowl of thirties, is scared of its return. Lower well outputs and increasing pumping costs have compelled farmers to adapt alternative conservation strate...

Simulating and evaluating best management practices for integrated landscape management scenarios in biofuel feedstock production: Evaluating Best Management Practices for Biofuel Feedstock Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ha, Miae; Wu, May

Sound crop and land management strategies can maintain land productivity and improve the environmental sustainability of agricultural crop and feedstock production. This study evaluates the improvement of water sustainability through an integrated landscaping management strategy, where landscaping design, land management operations, crop systems, and agricultural best management practices (BMPs) play equal roles. The strategy was applied to the watershed of the South Fork Iowa River in Iowa, with a focus on implementing riparian buffers and converting low productivity land to provide cellulosic biomass while benefiting soil and water quality. The Soil and Water Assessment Tool (SWAT) was employed to simulatemore » the impact of integrated landscape design on nutrients, suspended sediments, and flow on the watershed and subbasin scales. First, the study evaluated the representation of buffer strip as a vegetative barrier and as a riparian buffer using trapping efficiency and area ratio methods in SWAT. For the riparian buffer, the area ratio method tends to be more conservative, especially in nitrate loadings, while the trapping efficiency method generates more optimistic results. The differences between the two methods increase with buffer width. The two methods may not be comparable for the field-scale vegetative barrier simulation because of limitations in model spatial resolution. Landscape scenarios were developed to quantify water quality under (1) current land use, (2) partial land conversion to switchgrass, and (3) riparian buffer implementation. Results show that when low productivity land (15.2% of total watershed land area) is converted to grow switchgrass, suspended sediment, total nitrogen, total phosphorus, and nitrate loadings are reduced by 69.3%, 55.5%, 46.1%, and 13.4%, respectively, in the watershed surface streams. The reduction was less extensive when riparian buffer strips (30 m or 50 m) were applied to the stream network at 1.4% of total land area in the watershed. At the subbasin level, the degree of nutrient and suspended sediment reduction varies extensively, ranging from a few percent up to 55%. Results indicate that effective landscape design on current agricultural land can potentially bring marked improvements in water quality and soil erosion control while producing food and fuel feedstock in the South Fork Iowa River watershed. The concept can be integrated with other watershed management programs to improve sustainability of land, water, and the ecosystem.« less

Allelopathic cover crop prior to seeding is more important than subsequent grazing/mowing in Grassland establishment

USGS Publications Warehouse

Milchunas, D.G.; Vandever, M.W.; Ball, L.O.; Hyberg, S.

2011-01-01

The effects of grazing, mowing, and type of cover crop were evaluated in a previous winter wheat-fallow cropland seeded to grassland under the Conservation Reserve Program in eastern Colorado. Prior to seeding, the fallow strips were planted to forage sorghum or wheat in alternating strips (cover crops), with no grazing, moderate to heavy grazing, and mowing (grazing treatments) superimposed 4 yr after planting and studied for 3 yr. Plots previously in wheat had more annual and exotic species than sorghum plots. Concomitantly, there were much greater abundances of perennial native grass and all native species in sorghum than wheat cropped areas. The competitive advantage gained by seeded species in sorghum plots resulted in large increases in rhizomatous western wheatgrass. Sorghum is known to be allelopathic and is used in crop agriculture rotations to suppress weeds and increase crop yields, consistent with the responses of weed and desired native species in this study. Grazing treatment had relatively minor effects on basal and canopy cover composition of annual or exotic species versus perennial native grass or native species. Although grazing treatment never was a significant main effect, it occasionally modified cover crop or year effects. Opportunistic grazing reduced exotic cheatgrass by year 3 but also decreased the native palatable western wheatgrass. Mowing was a less effective weed control practice than grazing. Vegetative basal cover and aboveground primary production varied primarily with year. Common management practices for revegetation/restoration currently use herbicides and mowing as weed control practices and restrict grazing in all stages of development. Results suggest that allelopathic cover crop selection and opportunistic grazing can be effective alternative grass establishment and weed control practices. Susceptibility, resistance, and interactions of weed and seeded species to allelopathic cover species/cultivars may be a fruitful area of research. ?? 2011 Society for Range Management.

Weed Dynamics during Transition to Conservation Agriculture in Western Kenya Maize Production

PubMed Central

Odhiambo, Judith A.; Norton, Urszula; Ashilenje, Dennis; Omondi, Emmanuel C.; Norton, Jay B.

2015-01-01

Weed competition is a significant problem in maize (Zea mays, L.) production in Sub-Saharan Africa. Better understanding of weed management and costs in maize intercropped with beans (Phaseolus vulgaris, L.) during transition to conservation agricultural systems is needed. Changes in weed population and maize growth were assessed for a period of three years at Bungoma where crops are grown twice per year and at Trans-Nzoia where crops are grown once per year. Treatments included three tillage practices: minimum (MT), no-till (NT) and conventional (CT) applied to three cropping systems: continuous maize/bean intercropping (TYPICAL), maize/bean intercropping with relayed mucuna after bean harvest (RELAY) and maize, bean and mucuna planted in a strip intercropping arrangement (STRIP). Herbicides were used in NT, shallow hand hoeing and herbicides were used in MT and deep hoeing with no herbicides were used in CT. Weed and maize performance in the maize phase of each cropping system were assessed at both locations and costs of weed control were estimated at Manor House only. Weed density of grass and forb species declined significantly under MT and NT at Manor House and of grass species only at Mabanga. The greatest declines of more than 50% were observed as early as within one year of the transition to MT and NT in STRIP and TYPICAL cropping systems at Manor House. Transitioning to conservation based systems resulted in a decline of four out of five most dominant weed species. At the same time, no negative impact of MT or NT on maize growth was observed. Corresponding costs of weed management were reduced by $148.40 ha-1 in MT and $149.60 ha-1 in NT compared with CT. In conclusion, farmers can benefit from effective and less expensive weed management alternatives early in the process of transitioning to reduced tillage operations. PMID:26237404

Weed Dynamics during Transition to Conservation Agriculture in Western Kenya Maize Production.

PubMed

Odhiambo, Judith A; Norton, Urszula; Ashilenje, Dennis; Omondi, Emmanuel C; Norton, Jay B

2015-01-01

Weed competition is a significant problem in maize (Zea mays, L.) production in Sub-Saharan Africa. Better understanding of weed management and costs in maize intercropped with beans (Phaseolus vulgaris, L.) during transition to conservation agricultural systems is needed. Changes in weed population and maize growth were assessed for a period of three years at Bungoma where crops are grown twice per year and at Trans-Nzoia where crops are grown once per year. Treatments included three tillage practices: minimum (MT), no-till (NT) and conventional (CT) applied to three cropping systems: continuous maize/bean intercropping (TYPICAL), maize/bean intercropping with relayed mucuna after bean harvest (RELAY) and maize, bean and mucuna planted in a strip intercropping arrangement (STRIP). Herbicides were used in NT, shallow hand hoeing and herbicides were used in MT and deep hoeing with no herbicides were used in CT. Weed and maize performance in the maize phase of each cropping system were assessed at both locations and costs of weed control were estimated at Manor House only. Weed density of grass and forb species declined significantly under MT and NT at Manor House and of grass species only at Mabanga. The greatest declines of more than 50% were observed as early as within one year of the transition to MT and NT in STRIP and TYPICAL cropping systems at Manor House. Transitioning to conservation based systems resulted in a decline of four out of five most dominant weed species. At the same time, no negative impact of MT or NT on maize growth was observed. Corresponding costs of weed management were reduced by $148.40 ha(-1) in MT and $149.60 ha(-1) in NT compared with CT. In conclusion, farmers can benefit from effective and less expensive weed management alternatives early in the process of transitioning to reduced tillage operations.

Length and area equivalents for interpreting wildland resource maps

Treesearch

Elliot L. Amidon; Marilyn S. Whitfield

1969-01-01

Map users must refer to an appropriate scale in interpreting wildland resource maps. Length and area equivalents for nine map scales commonly used have been computed. For each scale a 1-page table consists of map-to-ground equivalents, buffer strip or road widths, and cell dimensions required for a specified acreage. The conversion factors are stored in a Fortran...

What are we hiding behind the visual buffer strip?: forest aesthetics reconsidered

Treesearch

Bruce R. Hull; David P. Robertson; Gregory J. Buhyoff; Angelina Kendra

2000-01-01

The forestry profession has no offical policy on forest aesthetics: Neither foresters nor the public have clear guidelines as to what a socially acceptable, actively managed forest should lookl ike. Hints of an impplicit policy can be found in the Society of American Foresters (SAF) position statements on timber harvesting and in various recommendations for best...

EnviroAtlas - Austin, TX - 15m Riparian Buffer Vegetated Cover

EPA Pesticide Factsheets

This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is vegetated. Vegetated cover is defined as Trees & Forest and Grass & Herbaceous. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Des Moines, IA - 51m Riparian Buffer Vegetated Cover

EPA Pesticide Factsheets

This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. Vegetated cover is defined as Trees & Forest and Grass & Herbaceous. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://enviroatlas.epa.gov/EnviroAtlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets)

EnviroAtlas - New York, NY - 51m Riparian Buffer Vegetated Cover

EPA Pesticide Factsheets

This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. In this community, vegetated cover is defined as Trees & Forest and Grass & Herbaceous. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets)

EnviroAtlas - Austin, TX - 51m Riparian Buffer Vegetated Cover

EPA Pesticide Factsheets

This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. Vegetated cover is defined as Trees & Forest and Grass & Herbaceous. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Memphis, TN - 51m Riparian Buffer Vegetated Cover

EPA Pesticide Factsheets

This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. Vegetated cover is defined as Trees & Forest, Grass & Herbaceous, Woody Wetlands, and Emergent Wetlands. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

EnviroAtlas - Cleveland, OH - 51m Riparian Buffer Vegetated Cover

EPA Pesticide Factsheets

This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. In this community, vegetated cover is defined as Trees & Forest, Grass & Herbaceous, Woody Wetlands, and Emergent Wetlands. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas ) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets)

Avoiding social traps in the ecosystem stewardship: The Italian Fontanile lowland spring.

PubMed

Balderacchi, Matteo; Perego, Alessia; Lazzari, Giovanni; Muñoz-Carpena, Rafael; Acutis, Marco; Laini, Alex; Giussani, Andrea; Sanna, Mattia; Kane, David; Trevisan, Marco

2016-01-01

Fontanile is a Po Valley (Italy) quasi-natural lowland spring built in the middle age. This paper identifies options for the conservation of the Fontanile water dependent ecosystem, using scenarios and simulations, and exploring different policy options. Three modeling analysis have been performed: the first was carried out for estimating groundwater contamination and recharge from above, the second for evaluating the function of vegetative filter strip on the surface water quality and the last one for testing pesticide drift reduction due to the vegetative filter strip. Uncertainty characterization included climate change projections. Despite the nitrate concentration in water could favorite the eutrophication phenomena, this not occurs because of the low phosphate concentration in water and of the presence of arboreal shade. Therefore, the protection strategies must focus on sustaining desirable water quantity conditions. Water saving and conservation technologies that improve the agricultural productivity but reduce the Fontanile water flow and large buffer strips that have a limited efficacy due to the Fontanile hydrological settings can be judged as ecological traps. Inefficient irrigation systems, good agricultural practices, integrated pest management and arboreal filter strip can preserve the quality of those ecosystems. Copyright © 2015 Elsevier B.V. All rights reserved.

Enzyme potentiated desensitisation in treatment of seasonal allergic rhinitis: double blind randomised controlled study.

PubMed

Radcliffe, Michael J; Lewith, George T; Turner, Richard G; Prescott, Philip; Church, Martin K; Holgate, Stephen T

2003-08-02

To assess the efficacy of enzyme potentiated desensitisation in the treatment of severe summer hay fever poorly controlled by pharmacotherapy. Double blind randomised placebo controlled parallel group study. Hospital in Hampshire. 183 participants aged between 18 and 64 with a history of severe summer hay fever for at least two years; all were skin prick test positive to timothy grass pollen. 90 randomised to active treatment; 93 randomised to placebo. Active treatment: two injections of enzyme potentiated desensitisation, given between eight and 11 weeks apart, each comprising 200 Fishman units of beta glucuronidase, 50 pg 1,3-cyclohexanediol, 50 ng protamine sulphate, and a mixed inhaled allergen extract (pollen mixes for trees, grasses, and weeds; allergenic fungal spores; cat and dog danders; dust and storage mites) in a total volume of 0.05 ml of buffered saline. Placebo: two injections of 0.05 ml buffered saline solution. Proportion of problem-free days; global rhinoconjunctivitis quality of life scores assessed weekly during pollen season. The active treatment group and the placebo group did not differ in the proportion of problem-free days, quality of life scores, symptom severity scores, change in quantitative skin prick provocation threshold, or change in conjunctival provocation threshold. No clinically significant adverse reactions occurred. Enzyme potentiated desensitisation showed no treatment effect in this study.

Femtosecond laser direct-write of optofluidics in polymer-coated optical fiber

NASA Astrophysics Data System (ADS)

Joseph, Kevin A. J.; Haque, Moez; Ho, Stephen; Aitchison, J. Stewart; Herman, Peter R.

2017-03-01

Multifunctional lab in fiber technology seeks to translate the accomplishments of optofluidic, lab on chip devices into silica fibers. a robust, flexible, and ubiquitous optical communication platform that can underpin the `Internet of Things' with distributed sensors, or enable lab on chip functions deep inside our bodies. Femtosecond lasers have driven significant advances in three-dimensional processing, enabling optical circuits, microfluidics, and micro-mechanical structures to be formed around the core of the fiber. However, such processing typically requires the stripping and recoating of the polymer buffer or jacket, increasing processing time and mechanically weakening the device. This paper reports on a comprehensive assessment of laser damage in urethane-acrylate-coated fiber. The results show a sufficient processing window is available for femtosecond laser processing of the fiber without damaging the polymer jacket. The fiber core, cladding, and buffer could be simultaneously processed without removal of the buffer jacket. Three-dimensional lab in fiber devices were successfully fabricated by distortion-free immersionlens focusing, presenting fiber-cladding optical circuits and progress towards chemically-etched channels, microfluidic cavities, and MEMS structure inside buffer-coated fiber.

National Program for Inspection of Non-Federal Dams. Somersville Pond Dam (CT 00273), Connecticut River Basin, Somers, Connecticut. Phase I Inspection Report.

DTIC Science & Technology

1980-08-01

dam. . 2.2 Construction Data. No record of original construction is avail- ’.. able for this dam. A general location plan prepared by Reino E. low Hyypa...and S"’: overuse. The slopes of the shoreline are flat and generally well covered with grass and vegetation to preclude sloughing Pp. and shoreline...roadways. It is estimated that the water depths would average 9.8 feet and that velocities of flow could cause erosion, stripping of vegetation and

Sensitivity analysis and metamodeling of a toolchain of models to help sizing vetetative filter strips in a watershed.

NASA Astrophysics Data System (ADS)

Lauvernet, Claire; Noll, Dorothea; Muñoz-Carpena, Rafael; Carluer, Nadia

2014-05-01

In Europe, environmental agencies do the finding a significant presence of contaminants in surface water, which is partly due to pesticide applications. Vegetative filter strips (VFS), often located along rivers, are a common tool among other buffer zones to reduce non point source pollution of water by reducing surface runoff. However, they need to be adapted to the agro-pedo-climatic conditions, both in terms of position and size, in order to be efficient. This is one of the roles of TOPPS-PROWADIS project which involves European experts and stakeholders to develop and recommend Best Management Practices (BMPs) to reduce pesticide transfer by drift or runoff in several European countries. In this context, Irstea developed a guide accompanying the use of different tools, which allows designing VFS by simulating their efficiency to limit transfers. It needs the user to define both a scenario of incoming surface runoff and the buffer zone characteristics. First, the contributive zone (surface, length, slope) is derived from the topography by a GIS tool, HydroDem. ; 2nd, the runoff hydrograph coming in the buffer zone is generated from a rainfall hyetogram typical of the area, using Curve Number theory, taking into account soil characteristics. The VFS's optimal width is then deduced for a given desired efficiency (for example 70% of runoff reduction), by using VFSMOD model, which simulates water, suspended matters (and pesticides) transfer inside a vegetative filter strip. Results also indicate if this kind of buffer zone is relevant in that situation (if too high, another type of buffer zone may be more relevant, for example constructed wetland). This method assumes that the user supplies quite a lot of field knowledge and data, which are not always easily available. In order to fill in the lack of real data, a set of virtual scenarios was tested, which is supposed to cover a large range of agro-pedo-climatic conditions in Europe, considering both the upslope agricultural field and the VFS characteristics. These scenarios are based on: 2 types of climates (North and South-west of France), different rainfall intensities and durations, different lengths and slopes of hillslope, different humidity conditions, 4 soil types (silt loam, sandy loam, clay loam, sandy clay loam), 2 crops (wheat and corn) for the contributive area, 2 water table depths (1m and 2.5m) and 4 soil types for the VFS. The sizing method was applied for all these scenarios, and a sensitivity analysis of the VFS optimal length was performed for all the input parameters in order to understand their influence, and to identify for which a special care has to be given. Based on that sensitivity analysis, a metamodel has been developed. The idea is to simplify the whole toolchain and to make it possible to perform the buffer sizing by using a unique tool and a smaller set of parameters, given the available information from the end users. We first compared several mathematical methods to compute the metamodel, and then validated them on an agricultural watershed with real data in the North-West of France.

Modeling framework for representing long-term effectiveness of best management practices in addressing hydrology and water quality problems: Framework development and demonstration using a Bayesian method

NASA Astrophysics Data System (ADS)

Liu, Yaoze; Engel, Bernard A.; Flanagan, Dennis C.; Gitau, Margaret W.; McMillan, Sara K.; Chaubey, Indrajeet; Singh, Shweta

2018-05-01

Best management practices (BMPs) are popular approaches used to improve hydrology and water quality. Uncertainties in BMP effectiveness over time may result in overestimating long-term efficiency in watershed planning strategies. To represent varying long-term BMP effectiveness in hydrologic/water quality models, a high level and forward-looking modeling framework was developed. The components in the framework consist of establishment period efficiency, starting efficiency, efficiency for each storm event, efficiency between maintenance, and efficiency over the life cycle. Combined, they represent long-term efficiency for a specific type of practice and specific environmental concern (runoff/pollutant). An approach for possible implementation of the framework was discussed. The long-term impacts of grass buffer strips (agricultural BMP) and bioretention systems (urban BMP) in reducing total phosphorus were simulated to demonstrate the framework. Data gaps were captured in estimating the long-term performance of the BMPs. A Bayesian method was used to match the simulated distribution of long-term BMP efficiencies with the observed distribution with the assumption that the observed data represented long-term BMP efficiencies. The simulated distribution matched the observed distribution well with only small total predictive uncertainties. With additional data, the same method can be used to further improve the simulation results. The modeling framework and results of this study, which can be adopted in hydrologic/water quality models to better represent long-term BMP effectiveness, can help improve decision support systems for creating long-term stormwater management strategies for watershed management projects.

Estimating the financial risks of Andropogon gayanus to greenhouse gas abatement projects in northern Australia

NASA Astrophysics Data System (ADS)

Adams, Vanessa M.; Setterfield, Samantha A.

2013-06-01

Financial mechanisms such as offsets are one strategy to abate greenhouse gas emissions, and the carbon market is expanding with a growing demand for offset products. However, in the case of carbon offsets, if the carbon is released due to intentional or unintentional reversal through environmental events such as fire, the financial liability to replace lost offsets will likely fall on the provider. This liability may have implications for future participation in programmes, but common strategies such as buffer pool and insurance products can be used to minimize this liability. In order for these strategies to be effective, an understanding of the spatial and temporal distributions of expected reversals is needed. We use the case study of savanna burning, an approved greenhouse gas abatement methodology under the Carbon Farming Initiative in Australia, to examine potential risks to carbon markets in northern Australia and quantify the financial risks. We focus our analysis on the threat of Andropogon gayanus (gamba grass) to savanna burning due to its documented impacts of increased fuel loads and altered fire regimes. We assess the spatial and financial extent to which gamba grass poses a risk to savanna burning programmes in northern Australia. We find that 75% of the eligible area for savanna burning is spatially coincident with the high suitability range for gamba grass. Our analysis demonstrates that the presence of gamba grass seriously impacts the financial viability of savanna burning projects. For example, in order to recuperate the annual costs of controlling 1 ha of gamba grass infestation, 290 ha of land must be enrolled in annual carbon abatement credits. Our results show an immediate need to contain gamba grass to its current extent to avoid future spread into large expanses of land, which are currently profitable for savanna burning.

Concentrations of disinfection by-products in swimming pool following modifications of the water treatment process: An exploratory study.

PubMed

Tardif, Robert; Rodriguez, Manuel; Catto, Cyril; Charest-Tardif, Ginette; Simard, Sabrina

2017-08-01

The formation and concentration of disinfection by-products (DBPs) in pool water and the ambient air vary according to the type of water treatment process used. This exploratory study was aimed at investigating the short-term impact of modifications of the water treatment process on traditional DBP levels (e.g., trihalomethanes (THMs), chloramines) and emerging DBPs (e.g., Halonitromethanes, Haloketones, NDMA) in swimming pool water and/or air. A sampling program was carried to understand the impact of the following changes made successively to the standard water treatment process: activation of ultraviolet (UV) photoreactor, halt of air stripping with continuation of air extraction from the buffer tank, halt of air stripping and suppression of air extraction from the buffer tank, suppression of the polyaluminium silicate sulfate (PASS) coagulant. UV caused a high increase of Halonitromethanes (8.4 fold), Haloketones (2.1 fold), and THMs in the water (1.7 fold) and, of THMs in the air (1.6 fold) and contributed to reducing the level of chloramines in the air (1.6 fold) and NDMA in the water (2.1 fold). The results highlight the positive impact of air stripping in reducing volatile contaminants. The PASS did not change the presence of DBPs, except for the THMs, which decrease slightly with the use of this coagulant. This study shows that modifications affecting the water treatment process can rapidly produce important and variable impacts on DBP levels in water and air and suggests that implementation of any water treatment process to reduce DBP levels should take into account the specific context of each swimming pool. Copyright © 2017. Published by Elsevier B.V.

A Simple Challenge to Assist in the Understanding of Friction. Science Notes

ERIC Educational Resources Information Center

Jheeta, Sohan

2013-01-01

What is friction? Like gravity, friction is a type of force. In simple terms, friction is, by and large, resistance to movement when two or more objects slide past one another. In this task young people are challenged to build a "buffer" to stop a moving ball using only a piece of ordinary A4 paper or a strip cut from it; that is,…

Tree communities of lowland warm-temperate old-growth and neighboring shelterbelt forests in the Shikoku region of southwestern Japan

Treesearch

Shigeo Kuramoto; Shigenori Oshioka; Takahisa Hirayama; Kaori Sato; Yasumasa Hirata

2007-01-01

We characterized the tree species composition of a 30 ha old-growth and neighboring shelterbelt (reserved buffer strips among conifer plantations) in warm-temperate forests in the Shikoku region of southwestern Japan. Using a two-way indicator species analysis of data from 28 plots, we identified four structural groups in terms of relative basal area. These structural...

Mixed monofunctional extractants for trivalent actinide/lanthanide separations: TALSPEAK-MME

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Aaron T.; Nash, Kenneth L.

The basic features of an f-element extraction process based on a solvent composed of equimolar mixtures of Cyanex-923 (a mixed trialkyl phosphine oxide) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) extractants in n-dodecane are investigated in this report. This system, which combines features of the TRPO and TALSPEAK processes, is based on co-extraction of trivalent lanthanides and actinides from 0.1 to 1.0 M HNO 3 followed by application of a buffered aminopolycarboxylate solution strip to accomplish a Reverse TALSPEAK selective removal of actinides. This mixed-extractant medium could enable a simplified approach to selective trivalent f-element extraction and actinide partitioning in amore » single process. As compared with other combined process applications in development for more compact actinide partitioning processes (DIAMEX-SANEX, GANEX, TRUSPEAK, ALSEP), this combination features only monofunctional extractants with high solubility limits and comparatively low molar mass. Selective actinide stripping from the loaded extractant phase is done using a glycine-buffered solution containing N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA) or triethylenetetramine-N,N,N',N'',N''',N'''-hexaacetic acid (TTHA). Lastly, the results reported provide evidence for simplified interactions between the two extractants and demonstrate a pathway toward using mixed monofunctional extractants to separate trivalent actinides (An) from fission product lanthanides (Ln).« less

Mixed monofunctional extractants for trivalent actinide/lanthanide separations: TALSPEAK-MME

DOE PAGES

Johnson, Aaron T.; Nash, Kenneth L.

2015-08-20

The basic features of an f-element extraction process based on a solvent composed of equimolar mixtures of Cyanex-923 (a mixed trialkyl phosphine oxide) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) extractants in n-dodecane are investigated in this report. This system, which combines features of the TRPO and TALSPEAK processes, is based on co-extraction of trivalent lanthanides and actinides from 0.1 to 1.0 M HNO 3 followed by application of a buffered aminopolycarboxylate solution strip to accomplish a Reverse TALSPEAK selective removal of actinides. This mixed-extractant medium could enable a simplified approach to selective trivalent f-element extraction and actinide partitioning in amore » single process. As compared with other combined process applications in development for more compact actinide partitioning processes (DIAMEX-SANEX, GANEX, TRUSPEAK, ALSEP), this combination features only monofunctional extractants with high solubility limits and comparatively low molar mass. Selective actinide stripping from the loaded extractant phase is done using a glycine-buffered solution containing N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA) or triethylenetetramine-N,N,N',N'',N''',N'''-hexaacetic acid (TTHA). Lastly, the results reported provide evidence for simplified interactions between the two extractants and demonstrate a pathway toward using mixed monofunctional extractants to separate trivalent actinides (An) from fission product lanthanides (Ln).« less

Interactive communication channel

NASA Astrophysics Data System (ADS)

Chan, R. H.; Mann, M. R.; Ciarrocchi, J. A.

1985-10-01

Discussed is an interactive communications channel (ICC) for providing a digital computer with high-performance multi-channel interfaces. Sixteen full duplex channels can be serviced in the ICC with the sequence or scan pattern being programmable and dependent upon the number or channels and their speed. A channel buffer system is used for line interface, and character exchange. The channel buffer system is on a byte basis. The ICC performs frame start and frame end functions, bit stripping and bit stuffing. Data is stored in a memory in block format (256 bytes maximum) by a program control and the ICC maintains byte address information and a block byte count. Data exchange with a memory is made by cycle steals. Error detection is also provided for using a cyclic redundancy check technique.

Sealed head access area enclosure

DOEpatents

Golden, Martin P.; Govi, Aldo R.

1978-01-01

A liquid-metal-cooled fast breeder power reactor is provided with a sealed head access area enclosure disposed above the reactor vessel head consisting of a plurality of prefabricated structural panels including a center panel removably sealed into position with inflatable seals, and outer panels sealed into position with semipermanent sealant joints. The sealant joints are located in the joint between the edge of the panels and the reactor containment structure and include from bottom to top an inverted U-shaped strip, a lower layer of a room temperature vulcanizing material, a separator strip defining a test space therewithin, and an upper layer of a room temperature vulcanizing material. The test space is tapped by a normally plugged passage extending to the top of the enclosure for testing the seal or introducing a buffer gas thereinto.

EnviroAtlas - Minneapolis/St. Paul, MN - 51m Riparian Buffer Vegetated Cover

EPA Pesticide Factsheets

This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. In this community, vegetated cover is defined as Trees and Forest, Grass and Herbaceous, Woody Wetlands, and Emergent Wetlands. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

Sensory evaluation of tender beef strip loin steaks of varying marbling levels and quality treatments.

PubMed

Corbin, C H; O'Quinn, T G; Garmyn, A J; Legako, J F; Hunt, M R; Dinh, T T N; Rathmann, R J; Brooks, J C; Miller, M F

2015-02-01

The palatability of tender [Warner-Bratzler shear force values <33.34N (3.4kg)] beef strip loins of 10 different treatments [USDA Prime, High Choice (upper 1/3 Choice), Low Choice (lower 1/3 Choice), Select, Standard, Australian Wagyu, American Wagyu, Holstein Select, Holstein Top Choice (upper 2/3 Choice) and Grass-finished] was evaluated by consumers and a trained flavor panel. In general, tenderness, juiciness, flavor, and overall liking ratings as well as acceptability percentage for each trait, increased with increased fat levels. Moreover, overall liking was highly correlated (P<0.01) with flavor liking (r=0.96) as well as fat percentage (r=0.79). Beef flavor scores were positively associated (P<0.01) with fat-like (r=0.67) and umami (r=0.59) flavors. Fat level was the primary driver of beef flavor acceptability in all samples when no undesirable off-flavors were present. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sediment measurement and transport modeling: impact of riparian and filter strip buffers.

PubMed

Moriasi, Daniel N; Steiner, Jean L; Arnold, Jeffrey G

2011-01-01

Well-calibrated models are cost-effective tools to quantify environmental benefits of conservation practices, but lack of data for parameterization and evaluation remains a weakness to modeling. Research was conducted in southwestern Oklahoma within the Cobb Creek subwatershed (CCSW) to develop cost-effective methods to collect stream channel parameterization and evaluation data for modeling in watersheds with sparse data. Specifically, (i) simple stream channel observations obtained by rapid geomorphic assessment (RGA) were used to parameterize the Soil and Water Assessment Tool (SWAT) model stream channel variables before calibrating SWAT for streamflow and sediment, and (ii) average annual reservoir sedimentation rate, measured at the Crowder Lake using the acoustic profiling system (APS), was used to cross-check Crowder Lake sediment accumulation rate simulated by SWAT. Additionally, the calibrated and cross-checked SWAT model was used to simulate impacts of riparian forest buffer (RF) and bermudagrass [ (L.) Pers.] filter strip buffer (BFS) on sediment yield and concentration in the CCSW. The measured average annual sedimentation rate was between 1.7 and 3.5 t ha yr compared with simulated sediment rate of 2.4 t ha yr Application of BFS across cropped fields resulted in a 72% reduction of sediment delivery to the stream, while the RF and the combined RF and BFS reduced the suspended sediment concentration at the CCSW outlet by 68 and 73%, respectively. Effective riparian practices have potential to increase reservoir life. These results indicate promise for using the RGA and APS methods to obtain data to improve water quality simulations in ungauged watersheds. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Hydrological heterogeneity in agricultural riparian buffer strips

NASA Astrophysics Data System (ADS)

Hénault-Ethier, Louise; Larocque, Marie; Perron, Rachel; Wiseman, Natalie; Labrecque, Michel

2017-03-01

Riparian buffer strips (RBS) may protect surface water and groundwater in agricultural settings, although their effectiveness, observed in field-scale studies, may not extend to a watershed scale. Hydrologically-controlled leaching plots have often shown RBS to be effective at buffering nutrients and pesticides, but uncontrolled field studies have sometimes suggested limited effectiveness. The limited RBS effectiveness may be explained by the spatiotemporal hydrological heterogeneity near non-irrigated fields. This hypothesis was tested in conventional corn and soy fields in the St. Lawrence Lowlands of southern Quebec (Canada), where spring melt brings heavy and rapid runoff, while summer months are hot and dry. One field with a mineral soil (Saint-Roch-de-l'Achigan) and another with an organic-rich soil (Boisbriand) were equipped with passive runoff collectors, suction cup lysimeters, and piezometers placed before and after a 3 m-wide RBS, and monitored from 2011 to 2014. Soil topography of the RBS was mapped to a 1 cm vertical precision and a 50 cm sampling grid. On average, surface runoff intersects the RBS perpendicularly, but is subject to substantial local heterogeneity. Groundwater saturates the root zones, but flows little at the time of snowmelt. Groundwater flow is not consistently perpendicular to the RBS, and may reverse, flowing from stream to field under low water flow regimes with stream-aquifer connectivity, thus affecting RBS effectiveness calculations. Groundwater flow direction can be influenced by stratigraphy, local soil hydraulic properties, and historical modification of the agricultural stream beds. Understanding the spatiotemporal heterogeneity of surface and groundwater flows is essential to correctly assess the effectiveness of RBS in intercepting agro-chemical pollution. The implicit assumption that water flows across vegetated RBS, from the field to the stream, should always be verified.

Climate and on-farm risk factors associated with Giardia duodenalis cysts in storm runoff from California coastal dairies.

PubMed

Miller, Woutrina A; Lewis, David J; Lennox, Michael; Pereira, Maria G C; Tate, Kenneth W; Conrad, Patricia A; Atwill, Edward R

2007-11-01

Climatic factors and on-farm management practices were evaluated for their association with the concentrations (cyst/liter) and instantaneous loads (cysts/second) of Giardia duodenalis in storm-based runoff from dairy lots and other high-cattle-use areas on five coastal California farms over two storm seasons. Direct fluorescent antibody analysis was used to quantitate cysts in 350 storm runoff samples. G. duodenalis was detected on all five dairy farms, with fluxes of 1 to 14,000 cysts/liter observed in 16% of samples. Cysts were detected in 41% of runoff samples collected near cattle less than 2 months old, compared to 10% of runoff samples collected near cattle over 6 months old. Furthermore, the concentrations and instantaneous loads of cysts were > or =65 and > or =79 times greater, respectively, in runoff from sites housing young calves than in sites housing other age classes of animals. Factors associated with environmental loading of G. duodenalis included cattle age, cattle stocking number, and precipitation but not lot area, land slope, or cattle density. Vegetated buffer strips were found to significantly reduce waterborne cysts in storm runoff: each additional meter of vegetated buffer placed below high-cattle-use areas was associated with reductions in the concentration and instantaneous load of cysts by factors of 0.86 and 0.79 (-0.07 and -0.10 log(10)/m), respectively. Straw mulch, seed application, scraping of manure, and cattle exclusion did not significantly affect the concentration or load of G. duodenalis cysts. The study findings suggest that vegetated buffer strips, especially when placed near dairy calf areas, should help reduce the environmental loading of these fecal protozoa discharging from dairy farms.

Evaluating the effectiveness of management practices on hydrology and water quality at watershed scale with a rainfall-runoff model.

PubMed

Liu, Yaoze; Bralts, Vincent F; Engel, Bernard A

2015-04-01

The adverse influence of urban development on hydrology and water quality can be reduced by applying best management practices (BMPs) and low impact development (LID) practices. This study applied green roof, rain barrel/cistern, bioretention system, porous pavement, permeable patio, grass strip, grassed swale, wetland channel, retention pond, detention basin, and wetland basin, on Crooked Creek watershed. The model was calibrated and validated for annual runoff volume. A framework for simulating BMPs and LID practices at watershed scales was created, and the impacts of BMPs and LID practices on water quantity and water quality were evaluated with the Long-Term Hydrologic Impact Assessment-Low Impact Development 2.1 (L-THIA-LID 2.1) model for 16 scenarios. The various levels and combinations of BMPs/LID practices reduced runoff volume by 0 to 26.47%, Total Nitrogen (TN) by 0.30 to 34.20%, Total Phosphorus (TP) by 0.27 to 47.41%, Total Suspended Solids (TSS) by 0.33 to 53.59%, Lead (Pb) by 0.30 to 60.98%, Biochemical Oxygen Demand (BOD) by 0 to 26.70%, and Chemical Oxygen Demand (COD) by 0 to 27.52%. The implementation of grass strips in 25% of the watershed where this practice could be applied was the most cost-efficient scenario, with cost per unit reduction of $1m3/yr for runoff, while cost for reductions of two pollutants of concern was $445 kg/yr for Total Nitrogen (TN) and $4871 kg/yr for Total Phosphorous (TP). The scenario with very high levels of BMP and LID practice adoption (scenario 15) reduced runoff volume and pollutant loads from 26.47% to 60.98%, and provided the greatest reduction in runoff volume and pollutant loads among all scenarios. However, this scenario was not as cost-efficient as most other scenarios. The L-THIA-LID 2.1 model is a valid tool that can be applied to various locations to help identify cost effective BMP/LID practice plans at watershed scales. Copyright © 2014 Elsevier B.V. All rights reserved.

Agricultural conservation practices can help mitigate the impact of climate change.

PubMed

Wagena, Moges B; Easton, Zachary M

2018-09-01

Agricultural conservation practices (CPs) are commonly implemented to reduce diffuse nutrient pollution. Climate change can complicate the development, implementation, and efficiency of agricultural CPs by altering hydrology, nutrient cycling, and erosion. This research quantifies the impact of climate change on hydrology, nutrient cycling, erosion, and the effectiveness of agricultural CP in the Susquehanna River Basin in the Chesapeake Bay Watershed, USA. We develop, calibrate, and test the Soil and Water Assessment Tool-Variable Source Area (SWAT-VSA) model and select four CPs; buffer strips, strip-cropping, no-till, and tile drainage, to test their effectiveness in reducing climate change impacts on water quality. We force the model with six downscaled global climate models (GCMs) for a historic period (1990-2014) and two future scenario periods (2041-2065 and 2075-2099) and quantify the impact of climate change on hydrology, nitrate-N (NO 3 -N), total N (TN), dissolved phosphorus (DP), total phosphorus (TP), and sediment export with and without CPs. We also test prioritizing CP installation on the 30% of agricultural lands that generate the most runoff (e.g., critical source areas-CSAs). Compared against the historical baseline and with no CPs, the ensemble model predictions indicate that climate change results in annual increases in flow (4.5±7.3%), surface runoff (3.5±6.1%), sediment export (28.5±18.2%) and TN export (9.5±5.1%), but decreases in NO 3 -N (12±12.8%), DP (14±11.5), and TP (2.5±7.4%) export. When agricultural CPs are simulated most do not appreciably change the water balance, however, tile drainage and strip-cropping decrease surface runoff, sediment export, and DP/TP, while buffer strips reduce N export. Installing CPs on CSAs results in nearly the same level of performance for most practices and most pollutants. These results suggest that climate change will influence the performance of agricultural CPs and that targeting agricultural CPs to CSAs can provide nearly the same level of water quality effects as more widespread adoption. Copyright © 2018 Elsevier B.V. All rights reserved.

EnviroAtlas - New York, NY - One Meter Resolution Urban Land Cover Data (2008) Web Service

EPA Pesticide Factsheets

This EnviroAtlas web service supports research and online mapping activities related to EnviroAtlas (https://www.epa.gov/enviroatlas ). The New York, NY EnviroAtlas Meter-scale Urban Land Cover (MULC) Data were generated by the University of Vermont Spatial Analysis Laboratory (SAL) under the direction of Jarlath O'Neil-Dunne as part of the United States Forest Service Urban Tree Canopy (UTC) assessment program. Seven classes were mapped using LiDAR and high resolution orthophotography: Tree Canopy, Grass/Shrub, Bare Soil, Water, Buildings, Roads/Railroads, and Other Paved Surfaces. These data were subsequently merged to fit with the EPA classification. The SAL project covered the five boroughs within the NYC city limits. However the EPA study area encompassed that area plus a 1 kilometer buffer. Additional land cover for the buffer area was generated from United States Department of Agriculture (USDA) National Agricultural Imagery Program (NAIP) four band (red, green, blue, and near infrared) aerial photography at 1 m spatial resolution from July, 2011 and LiDAR from 2010. Six land cover classes were mapped: water, impervious surfaces, soil and barren land, trees, grass-herbaceous non-woody vegetation, and agriculture. An accuracy assessment of 600 completely random and 55 stratified random photo interpreted reference points yielded an overall User's fuzzy accuracy of 87 percent. The area mapped is the US Census Bureau's 2010 Urban Statistical Area for New Yor

Enzyme potentiated desensitisation in treatment of seasonal allergic rhinitis: double blind randomised controlled study

PubMed Central

Radcliffe, Michael J; Lewith, George T; Turner, Richard G; Prescott, Philip; Church, Martin K; Holgate, Stephen T

2003-01-01

Objective To assess the efficacy of enzyme potentiated desensitisation in the treatment of severe summer hay fever poorly controlled by pharmacotherapy. Design Double blind randomised placebo controlled parallel group study. Setting Hospital in Hampshire. Participants 183 participants aged between 18 and 64 with a history of severe summer hay fever for at least two years; all were skin prick test positive to timothy grass pollen. 90 randomised to active treatment; 93 randomised to placebo. Interventions Active treatment: two injections of enzyme potentiated desensitisation, given between eight and 11 weeks apart, each comprising 200 Fishman units of β glucuronidase, 50 pg 1,3-cyclohexanediol, 50 ng protamine sulphate, and a mixed inhaled allergen extract (pollen mixes for trees, grasses, and weeds; allergenic fungal spores; cat and dog danders; dust and storage mites) in a total volume of 0.05 ml of buffered saline. Placebo: two injections of 0.05 ml buffered saline solution. Main outcome measures Proportion of problem-free days; global rhinoconjunctivitis quality of life scores assessed weekly during pollen season. Results The active treatment group and the placebo group did not differ in the proportion of problem-free days, quality of life scores, symptom severity scores, change in quantitative skin prick provocation threshold, or change in conjunctival provocation threshold. No clinically significant adverse reactions occurred. Conclusions Enzyme potentiated desensitisation showed no treatment effect in this study. PMID:12896934

Slow Light Semiconductor Laser

DTIC Science & Technology

2015-02-02

semi- conductor lasers, demonstrated here with a spectral linewidth of 18 kHz. Our approach circumvents historical limitations of laser design and it...Oxford 380). To turn the passive resonator into a high-Q hybrid laser, we smooth the waveguide sidewalls to improve Qsc by growing 15 nm of dry thermal ...oxide (oxidation times calculated using the Massoud model). We strip the oxide with HF (Transene Buffer HF- Improved), and regrow 20 nm of dry oxide

Conversion of native terrestrial ecosystems in Hawai‘i to novel grazing systems: a review

USGS Publications Warehouse

Leopold, Christina R.; Hess, Steven C.

2017-01-01

The remote oceanic islands of Hawai‘i exemplify the transformative effects that non-native herbivorous mammals can bring to isolated terrestrial ecosystems. We reviewed published literature containing systematically collected, analyzed, and peer-reviewed original data specifically addressing direct effects of non-native hoofed mammals (ungulates) on terrestrial ecosystems, and indirect effects and interactions on ecosystem processes in Hawai‘i. The effects of ungulates on native vegetation and ecosystems were addressed in 58 original studies and mostly showed strong short-term regeneration of dominant native trees and understory ferns after ungulate removal, but unassisted recovery was dependent on the extent of previous degradation. Ungulates were associated with herbivory, bark-stripping, disturbance by hoof action, soil erosion, enhanced nutrient cycling from the interaction of herbivory and grasses, and increased pyrogenicity and competition between native plants and pasture grasses. No studies demonstrated that ungulates benefitted native ecosystems except in short-term fire-risk reduction. However, non-native plants became problematic and continued to proliferate after release from herbivory, including at least 11 species of non-native pasture grasses that had become established prior to ungulate removal. Competition from non-native grasses inhibited native species regeneration where degradation was extensive. These processes have created novel grazing systems which, in some cases, have irreversibly altered Hawaii’s terrestrial ecology. Non-native plant control and outplanting of rarer native species will be necessary for recovery where degradation has been extensive. Lack of unassisted recovery in some locations should not be construed as a reason to not attempt restoration of other ecosystems.

The Corps of Engineers and Prairie Restoration: Synopsis of the First Corps Prairie Workshop, Follow-up Actions, and Thoughts on the Future of Prairie Restoration and Management on Operational Projects

DTIC Science & Technology

2009-06-01

Corps super- vision regarding management practices such as cropping systems and cattle grazing. Also, the Corps’ focus at the time was on tree planting...on crop rotation and removal of grazing. Changes included the installation of 100-ft-wide warm-season native grass strips between each agricultural...brood-rearing habitat, but it was not always possible to put that much land aside. Idle fields consisted of 5- to 15-acre blocks centered in row crop

How field monitoring of green infrastructure stormwater practices has led to changes in North Carolina's Stormwater BMP design manual

NASA Astrophysics Data System (ADS)

Hunt, W. F.; Winston, R. J.

2011-12-01

Green Infrastructure stormwater management is comprised of many biologically-based stormwater treatment practices. Two of which, bioretention and level spreader- vegetative filter strips, have been extensively studied at over 10 different field locations across North Carolina by NC State University. The result of this research has been dramatic changes to the state of North Carolina's stormwater BMP Design Manual, which now allows a greater amount of flexibility for the design of each practice than most other design manuals. The purpose of this presentation is to present a summary of research conducted in North Carolina and associate that research with specific changes made in the state's design guidance for both bioretention (Table 1) and level spreader- vegetated filter strip systems (Table 2). Among the changes are type of vegetation, ratio of hydraulic loading, underdrainage configuration, and fill media selection. References (in print) associated with the tables are listed below: Hathaway, J.M. and W.F. Hunt. 2008. Field Evaluation of Level Spreaders in the Piedmont of North Carolina. Journal of Irrigation and Drainage Engineering, 134(4):538-542. Hunt, W.F., A.R. Jarrett, J.T. Smith, L.J. Sharkey. 2006. Evaluating Bioretention Hydrology and Nutrient Removal at Three Field Sites in North Carolina. Journal of Irrigation and Drainage Engineering, 132 (6): 600-608. Hunt, W.F., J.M. Hathaway, R.J. Winston, and S.J. Jadlocki. 2010. Runoff Volume Reduction by a Level Spreader - Vegetated Filter Strip System in Suburban Charlotte, NC. Journal of Hydrologic Engineering, 15(6): 399-503. Jones, M.P. and W.F. Hunt. 2009. Bioretention Impact on Runoff Temperature in Trout Sensitive Waters. Journal of Environmental Engineering, 135(8): 577-585. Li, H., L.J. Sharkey, W.F. Hunt, A.P. Davis. 2009. Mitigation of Impervious Surface Hydrology using Bioretention in North Carolina and Maryland. Journal of Hydrologic Engineering, 14(4): 407-415. Line, D.E. and W.F. Hunt. 2009. Performance of a Bioretention Area and a Level Spreader-Grass Filter Strip at Two Highway Sites in North Carolina. Journal of Irrigation and Drainage Engineering, 135(2): 217-224. Passeport, E., W.F. Hunt, D.E. Line, R.A. Smith, and R.A. Brown. 2009. Field Study of the Ability of Two Grassed Bioretention Cells to Reduce Stormwater Runoff Pollution. Journal of Irrigation and Drainage Engineering, 135(4): 505-510. Winston, R.J., W.F. Hunt, D.L. Osmond, W.G. Lord, and M.D. Woodward. 2011. Field Evaluation of Four Level Spreader - Vegetative Filter Strips to Improve Urban Stormwater Quality. Journal of Irrigation and Drainage Engineering. 137(3): 170-182.
Table 1 - Research-Based Design Changes for Bioretention in North Carolina Table 2 - Level Spreader - Vegetated Filter Strip Design Evolution in North Carolina

Possible mechanism of the potent vasoconstrictor actions of ryanodine on femoral arteries from spontaneously hypertensive rats.

PubMed Central

Asano, M.; Kuwako, M.; Nomura, Y.; Ito, K. M.; Ito, K.; Uyama, Y.; Imaizumi, Y.; Watanabe, M.

1996-01-01

1. The Ca2+ buffering function of sarcoplasmic reticulum (SR) in the resting state of arteries from spontaneously hypertensive rats (SHR) was examined. Differences in the effects of ryanodine that removes the function of SR, on tension and cellular Ca2+ level were assessed in endothelium-denuded strips of femoral arteries from 13-week-old SHR and normotensive Wistar-Kyoto rats (WKY). 2. The addition of ryanodine to the resting strips caused a concentration-dependent contraction in SHR. This contraction was extremely small in WKY. In the presence of 10(-5) M ryanodine, caffeine (20 mM) failed to cause a further contraction in SHR, but it caused a small contraction in WKY. After washout of the strips with a Krebs solution, the resting tone was greatly elevated in SHR when compared with WKY. 3. The elevated resting tone in SHR strips was abolished by 10(-7) M nifedipine. The ryanodine-induced contraction was also abolished by 10(-7) M nifedipine. Nifedipine itself caused a relaxation from the resting tone of SHR strips, suggesting the maintenance of myogenic tone. 4. In strips preloaded with fura-PE3, the addition of 10(-5) M ryanodine caused a large and moderate elevation of cytosolic Ca2+ level ([Ca2+]i) in SHR and WKY, respectively. After washout, the resting [Ca2+]i was greatly elevated in SHR. The ryanodine-induced elevation of [Ca2+]i was decreased by 5 x 10(-6) M verapamil in SHR. Verapamil itself caused a decrease in resting [Ca2+]i which was significantly greater in SHR than in WKY, and caused a relaxation only in SHR. 5. The resting Ca2+ influx in arteries measured by a 5 min incubation with 45Ca was significantly increased in SHR when compared with WKY. The resting Ca2+ influx was not increased by 10(-5) M ryanodine in both SHR and WKY. The net cellular Ca2+ uptake in arteries measured by a 30 min incubation with 45Ca was decreased by 10(-5) M ryanodine in both strains. 6. The resting Ca2+ influx was decreased by 10(-7) M nifedipine in the SHR artery, but it was unchanged in the WKY artery. 7. These results suggest that (1) the Ca2+ influx via L-type voltage-dependent Ca2+ channels was increased in the resting state of the SHR femoral artery, (2) the greater part of the increased Ca2+ influx was buffered by Ca2+ uptake into the SR and some Ca2+ reached the myofilaments resulting in the maintenance of the myogenic tone, and (3) therefore the functional removal of SR by ryanodine caused a potent contraction in this artery. PMID:8799577

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacobsen, A. J.

In a method of the type where petrol is recovered from a mixture of petrol vapor and air by absorption of the petrol in a cooled petroleum distillate, a petroleum distillate having a boiling point range higher than that of the petrol is used, and this petroleum distillate is in sequence cooled by heat exchange with a cold reservoir, brought into direct contact with the petrol/air mixture to absorb petrol, transferred to a buffer tank and transferred from the buffer tank to a stripping means which may be a distillation column. By combining cooling condensation and absorption of the petrolmore » vapor and controlling the amount of cooled petroleum distillate brought into contact with the petrol/air mixture so that the petrol concentration in the petroleum distillate transferred to the buffer tank is substantially constant, an unprecedented optimum control of the petrol absorbing process can be obtained both in peak load and in average load operations. A system for carrying out the method is advantageous in that only the absorption means need be dimensioned for peak load operation, while the other components, such as the distillation column or a heat exchanger with associated conduits can be dimensioned for average loads, a buffer tank being provided to temporarily receive the petroleum distillate which owing to the above-mentioned control has a substantially constant, maximum petrol concentration so that the system can cope with peak loads with a surprisingly small buffer tank.« less

Farm factors associated with reducing Cryptosporidium loading in storm runoff from dairies.

PubMed

Miller, W A; Lewis, D J; Pereira, M D G; Lennox, M; Conrad, P A; Tate, K W; Atwill, E R

2008-01-01

A systems approach was used to evaluate environmental loading of Cryptosporidium oocysts on five coastal dairies in California. One aspect of the study was to determine Cryptosporidium oocyst concentrations and loads for 350 storm runoff samples from dairy high use areas collected over two storm seasons. Selected farm factors and beneficial management practices (BMPs) associated with reducing the Cryptosporidium load in storm runoff were assessed. Using immunomagnetic separation (IMS) with direct fluorescent antibody (DFA) analysis, Cryptosporidium oocysts were detected on four of the five farms and in 21% of storm runoff samples overall. Oocysts were detected in 59% of runoff samples collected near cattle less than 2 mo old, while 10% of runoff samples collected near cattle over 6 mo old were positive. Factors associated with environmental loading of Cryptosporidium oocysts included cattle age class, 24 h precipitation, and cumulative seasonal precipitation, but not percent slope, lot acreage, cattle stocking number, or cattle density. Vegetated buffer strips and straw mulch application significantly reduced the protozoal concentrations and loads in storm runoff, while cattle exclusion and removal of manure did not. The study findings suggest that BMPs such as vegetated buffer strips and straw mulch application, especially when placed near calf areas, will reduce environmental loading of fecal protozoa and improve stormwater quality. These findings are assisting working dairies in their efforts to improve farm and ecosystem health along the California coast.

Effects of winter manure application in Ohio on the quality of surface runoff.

PubMed

Owens, L B; Bonta, J V; Shipitalo, M J; Rogers, S

2011-01-01

Winter application of manure poses environmental risks. Seven continuous corn, instrumented watersheds (approximately 1 ha each) at the USDA-ARS North Appalachian Experimental Watershed research station near Coshocton, Ohio were used to evaluate the environmental impacts of winter manure application when using some of the Ohio Natural Resources Conservation Service recommendations. For 3 yr on frozen, sometimes snow-covered, ground in January or February, two watersheds received turkey litter, two received liquid swine manure, and three were control plots that received N fertilizer at planting (not manure). Manure was applied at an N rate for corn; the target level was 180 kg N ha(-1) with a 30-m setback from the application area to the bottom of each watershed. Four grassed plots (61 x 12 m) were used for beef slurry application (9.1 Mg ha(-1) wet weight); two plots had 61 x 12 m grassed filter areas below them, and two plots had 30 x 12 m filter areas. There were two control plots. Nutrient concentrations were sometimes high, especially in runoff soon after application. However, most events with high concentrations occurred with low flow volumes; therefore, transport was minimal. Applying manure at the N rate for crop needs resulted in excess application of P. Elevated P losses contributed to a greater potential of detrimental environmental impacts with P than with N. Filter strips reduced nutrient concentrations and transport, but the data were too limited to compare the effectiveness of the 30- and 61-m filter strips. Winter application of manure is not ideal, but by following prescribed guidelines, detrimental environmental impacts can be reduced.

Development of Lateral Flow Immunochromatographic Strips for Micropollutants Screening Using Colorants of Aptamer Functionalized Nanogold Particles Part I: Methodology and Optimization.

PubMed

Zhao, Shuai; Zhang, Shan; Wang, Sai; Liu, Jiahui; Dong, Yiyang

2018-05-03

A methodology of lateral flow immunochromatographic strip based on aptamer was developed for on-site detectionof the small molecule micropollutants. In the present study, we try for the first time to investigate the feasibility of developing a strip assay for the analysis of micropollutants as methodological prototypes by combining the high selectivity and affinity of aptamers with the unique optical properties of nanogolds. This quantitative method was based on the competition for the aptamer between targets and DNA probes. Crucial parameters that might influence the sensitivity, such as the size of nanogolds, amount of aptamer, type and pH of streptavidin, type of nitrocellulose (NC) membrane, blocking procedure, and reading time, were systematically investigated to obtain the optimum assay performance. With the optimized conditions [nanogolds 25 nm, 50 μM aptamer, pH 8 of GSA (a type of streptavidin named "SA Gold," which is a sulfhydrylization streptavidin), Millipore HFC 135 NC membrane, 1% bovine serum albumin as the blocking agent and added in the running buffer and sample pad soakage agents, and 20 min reading time] the aptamer-based lateral flow assay will show a low visual limit of detection and scanning reader LOD. The strip for on-site screening using colorants of aptamer functionalized nanogold particles did not require any complicated equipment and was a potential portable tool for rapid identification of micropollutants.

Transport of oxytetracycline, chlortetracycline, and ivermectin in surface runoff from irrigated pasture.

PubMed

Bair, Daniel A; Popova, Ina E; Tate, Kenneth W; Parikh, Sanjai J

2017-09-02

The transport of oxytetracycline, chlortetracycline, and ivermectin from manure was assessed via surface runoff on irrigated pasture. Surface runoff plots in the Sierra Foothills of Northern California were used to evaluate the effects of irrigation water application rates, pharmaceutical application conditions, vegetative cover, and vegetative filter strip length on the pharmaceutical discharge in surface runoff. Experiments were designed to permit the maximum potential transport of pharmaceuticals to surface runoff water, which included pre-irrigation to saturate soil, trimming grass where manure was applied, and laying a continuous manure strip perpendicular to the flow of water. However, due to high sorption of the pharmaceuticals to manure and soil, less than 0.1% of applied pharmaceuticals were detected in runoff water. Results demonstrated an increase of pharmaceutical transport in surface runoff with increased pharmaceutical concentration in manure, the concentration of pharmaceuticals in runoff water remained constant with increased irrigation flow rate, and no appreciable decrease in pharmaceutical runoff was produced with the vegetative filter strip length increased from 30.5 to 91.5 cm. Most of the applied pharmaceuticals were retained in the manure or within the upper 5 cm of soil directly beneath the manure application sites. As this study evaluated conditions for high transport potential, the data suggest that the risk for significant chlortetracycline, oxytetracycline, and ivermectin transport to surface water from cattle manure on irrigated pasture is low.

Distinct Contributory Factors Determine Basophil-Allergen Sensitivity in Grass Pollen Rhinitis and in Anaphylactic Wasp Venom Allergy.

PubMed

Korošec, Peter; Šilar, Mira; Kopač, Peter; Eržen, Renato; Zidarn, Mihaela; Košnik, Mitja

2016-01-01

We sought to determine whether basophil-allergen sensitivity could be transferred to donor basophils by passive IgE sensitisation in allergic rhinitis and anaphylactic Hymenoptera venom hypersensitivity. We studied 15 wasp venom-, 19 grass pollen- and 2 house dust mite-allergic patients, 2 healthy donors, and 8 wasp venom-allergic donors. In all subjects, we first evaluated the initial basophil response to wasp venom, grass pollen, or house dust mite allergen. Donor basophils were then stripped, sensitised with the different patients' serum IgE, and challenged with the corresponding allergen. The CD63 response of donor basophils was then compared with initial basophil responses. In wasp venom-allergic subjects, the IgE transfer did not reflect the initial basophil-allergen sensitivity, because the venom IgE of subjects with high or low basophil sensitivity induced comparable responsiveness in healthy donor basophils. Furthermore, vice versa, when we sensitised the donor basophils of wasp venom-allergic individuals with different wasp venom or house dust mite IgE, we demonstrated that their response was predictable by their initial basophil allergen sensitivity. In the rhinitis allergy model, the IgE transfer correlated with the patients' initial basophil responsiveness because the grass pollen IgE of the subjects with high basophil allergen sensitivity induced significantly higher responsiveness of donor basophils than the IgE of subjects with initially low basophil allergen sensitivity. Our results suggest that basophil allergen sensitivity evaluated by flow-cytometric CD63 analysis depends on two distinct contribution factors. In anaphylactic Hymenoptera allergy, the major factor was intrinsic cellular sensitivity, whereas in pollen allergy, the major factor was allergen-specific IgE on the cell surface. © 2016 S. Karger AG, Basel.

Linking Microbial Community Structure and Function During the Acidified Anaerobic Digestion of Grass

PubMed Central

Joyce, Aoife; Ijaz, Umer Z.; Nzeteu, Corine; Vaughan, Aoife; Shirran, Sally L.; Botting, Catherine H.; Quince, Christopher; O’Flaherty, Vincent; Abram, Florence

2018-01-01

Harvesting valuable bioproducts from various renewable feedstocks is necessary for the critical development of a sustainable bioeconomy. Anaerobic digestion is a well-established technology for the conversion of wastewater and solid feedstocks to energy with the additional potential for production of process intermediates of high market values (e.g., carboxylates). In recent years, first-generation biofuels typically derived from food crops have been widely utilized as a renewable source of energy. The environmental and socioeconomic limitations of such strategy, however, have led to the development of second-generation biofuels utilizing, amongst other feedstocks, lignocellulosic biomass. In this context, the anaerobic digestion of perennial grass holds great promise for the conversion of sustainable renewable feedstock to energy and other process intermediates. The advancement of this technology however, and its implementation for industrial applications, relies on a greater understanding of the microbiome underpinning the process. To this end, microbial communities recovered from replicated anaerobic bioreactors digesting grass were analyzed. The bioreactors leachates were not buffered and acidic pH (between 5.5 and 6.3) prevailed at the time of sampling as a result of microbial activities. Community composition and transcriptionally active taxa were examined using 16S rRNA sequencing and microbial functions were investigated using metaproteomics. Bioreactor fraction, i.e., grass or leachate, was found to be the main discriminator of community analysis across the three molecular level of investigation (DNA, RNA, and proteins). Six taxa, namely Bacteroidia, Betaproteobacteria, Clostridia, Gammaproteobacteria, Methanomicrobia, and Negativicutes accounted for the large majority of the three datasets. The initial stages of grass hydrolysis were carried out by Bacteroidia, Gammaproteobacteria, and Negativicutes in the grass biofilms, in addition to Clostridia in the bioreactor leachates. Numerous glycolytic enzymes and carbohydrate transporters were detected throughout the bioreactors in addition to proteins involved in butanol and lactate production. Finally, evidence of the prevalence of stressful conditions within the bioreactors and particularly impacting Clostridia was observed in the metaproteomes. Taken together, this study highlights the functional importance of Clostridia during the anaerobic digestion of grass and thus research avenues allowing members of this taxon to thrive should be explored. PMID:29619022

Perceived family social support buffers against the effects of exposure to rocket attacks on adolescent depression, aggression, and severe violence.

PubMed

Shahar, Golan; Henrich, Christopher C

2016-02-01

The authors compared the protective effects of 3 sources of perceived social support-from family members, friends, and school personnel-on internalizing and externalizing symptoms in adolescents exposed to rocket attacks. Data were based on 362 Israeli adolescents (median age = 14), chronically exposed to rockets from the Gaza Strip, for whom robust effects of exposure on internalizing and externalizing symptoms were reported during the 2009-2010 period (Henrich & Shahar, 2013). New analyses revealed that perceived family social support assessed in 2009 buffered against the effect of exposure to rocket attacks on depression, aggression, and severe violence during 2009-2010. Findings are consistent with a human-ecological perspective exposure to political violence and encourage the employment of family-based preventive interventions in afflicted areas. (c) 2016 APA, all rights reserved).

Determination of trace mercury in water based on N-octylpyridinium ionic liquids preconcentration and stripping voltammetry.

PubMed

Li, Zhenhan; Xia, Shanhong; Wang, Jinfen; Bian, Chao; Tong, Jianhua

2016-01-15

A novel method for determination of trace mercury in water is developed. The method is performed by extracting mercury firstly with ionic liquids (ILs) and then detecting the concentration of mercury in organic media with anodic stripping voltammetry. Liquid-liquid extraction of mercury(II) ions by four ionic liquids with N-octylpyridinium cations ([OPy](+)) was studied. N-octylpyridinium tetrafluoroborate and N-octylpyridinium trifluoromethylsulfonate were found to be efficient and selective extractant for mercury. Temperature controlled dispersive liquid phase microextraction (TC-DLPME) technique was utilized to improve the performance of preconcentration. After extraction, precipitated IL was diluted by acetonitrile buffer and mercury was detected by differential pulse stripping voltammetry (DPSV) with gold disc electrode. Mercury was enriched by 17 times while interfering ions were reduced by two orders of magnitude in the organic media under optimum condition. Sensitivity and selectivity for electrochemical determination of mercury were improved by using the proposed method. Tap, pond and waste water samples were analyzed with recoveries ranging from 81% to 107% and detection limit of 0.05 μg/L. Copyright © 2015 Elsevier B.V. All rights reserved.

Copper-Based Electrochemical Sensor with Palladium Electrode for Cathodic Stripping Voltammetry of Manganese

PubMed Central

2015-01-01

In this work, we report on the development of a palladium-based, microfabricated point-of-care electrochemical sensor for the determination of manganese using square wave cathodic stripping voltammetry. Heavy metals require careful monitoring, yet current methods are too complex for a point-of-care system. Voltammetry offers an attractive approach to metal detection on the microscale, but traditional carbon, gold, or platinum electrodes are difficult or expensive to microfabricate, preventing widespread use. Our sensor uses palladium working and auxiliary electrodes and integrates them with a copper-based reference electrode for simple fabrication and compatibility with microfabrication and printed circuit board processing, while maintaining competitive performance in electrochemical detection. Copper electrodes were prepared on glass substrate using a combination of microfabrication procedures followed by electrodeposition of palladium. The disposable sensor system was formed by bonding a poly(dimethylsiloxane) (PDMS) well to the glass substrate. Cathodic stripping voltammetry of manganese using our new disposable palladium-based sensors exhibited 334 nM (18.3 ppb) limit of detection in borate buffer. The sensor was used to demonstrate manganese determination in natural water samples from a pond in Burnet Woods, located in Cincinnati, OH, and the Ohio River. PMID:25476591

Copper-based electrochemical sensor with palladium electrode for cathodic stripping voltammetry of manganese.

PubMed

Kang, Wenjing; Pei, Xing; Bange, Adam; Haynes, Erin N; Heineman, William R; Papautsky, Ian

2014-12-16

In this work, we report on the development of a palladium-based, microfabricated point-of-care electrochemical sensor for the determination of manganese using square wave cathodic stripping voltammetry. Heavy metals require careful monitoring, yet current methods are too complex for a point-of-care system. Voltammetry offers an attractive approach to metal detection on the microscale, but traditional carbon, gold, or platinum electrodes are difficult or expensive to microfabricate, preventing widespread use. Our sensor uses palladium working and auxiliary electrodes and integrates them with a copper-based reference electrode for simple fabrication and compatibility with microfabrication and printed circuit board processing, while maintaining competitive performance in electrochemical detection. Copper electrodes were prepared on glass substrate using a combination of microfabrication procedures followed by electrodeposition of palladium. The disposable sensor system was formed by bonding a poly(dimethylsiloxane) (PDMS) well to the glass substrate. Cathodic stripping voltammetry of manganese using our new disposable palladium-based sensors exhibited 334 nM (18.3 ppb) limit of detection in borate buffer. The sensor was used to demonstrate manganese determination in natural water samples from a pond in Burnet Woods, located in Cincinnati, OH, and the Ohio River.

Neotropical migratory breeding bird communities in riparian forests of different widths along the Altamaha River, Georgia

USGS Publications Warehouse

Hodges, M.F.; Krementz, D.G.

1996-01-01

-We surveyed riparian forest corridors of different widths along the lower Altamaha River in Georgia in 1993 and 1994 to investigate the relationship between forest corridor width and Neotropical breeding bird community diversity and abundance. Species richness and abundance of three of six focal species increased with increasing forest corridor width. We suggest if Neotropical breeding bird communities are a target group, that land managers should consider leaving a 100 m buffer strip along riparian zones.

Seawater intrusion in the Salalah plain aquifer, Oman

NASA Astrophysics Data System (ADS)

Shammas, M. I.; Jacks, G.

2007-11-01

Salalah is situated on a fresh water aquifer that is replenished during the annual monsoon season. The aquifer is the only source of water in Salalah city. The rainfall and mist precipitation in the Jabal AlQara recharges the plain with significant renewable fresh groundwater that has allowed agricultural and industrial development to occur. In Salalah city where groundwater has been used extensively since the early 1980s for agricultural, industrial and municipal purposes, the groundwater has been withdrawn from the aquifer more rapidly than it can be replenished by natural recharge. The heavy withdrawal of large quantities of the groundwater from the aquifer has led to the intrusion of seawater. Agricultural activities utilize over 70% of the groundwater. For the study of the saltwater intrusion, the area has been divided into four strips, A, B, C and D, on the basis of land-use in the area. Water samples were collected from 18 water wells. Chemical analysis of major ions and pollution parameters in the groundwater was carried out and compared to the previous observed values. The electrical conductivity and chloride concentrations were highest in the agricultural and residential strips and Garziz grass farm. Before 1992 the aquifer was in a steady state, but presently (2005) the groundwater quality in most of the agricultural and residential strips does not meet drinking water standards. In addition, model simulations were developed with the computer code MODFLOW and MT3DMS for solute transport to determine the movement of the freshwater/saltwater interface. The study proposes the protection of the groundwater in Salalah plain aquifer from further encroachment by artificial recharge with reclaimed water, preferably along the Salalah coastal agricultural strip. This scheme can also be applied to other regions with similar conditions.

Development and evaluation of a highly sensitive immunochromatographic strip test using gold nanoparticle for direct detection of Vibrio cholerae O139 in seafood samples.

PubMed

Pengsuk, Chalinan; Chaivisuthangkura, Parin; Longyant, Siwaporn; Sithigorngul, Paisarn

2013-04-15

A strip test for the detection of Vibrio cholerae O139 was developed using two monoclonal antibodies (MAbs), namely VC-273 and VC-812, which specifically bind to the lipopolysaccharide and capsular polysaccharide of V. cholerae O139. The MAb VC-273 gold nanoparticle conjugate was sprayed onto a glass fiber pad that was placed adjacent to a sample chamber. MAb VC-812 and the goat anti-mouse immunoglobulin G (GAM) antibody were sprayed onto a nitrocellulose membrane in strips at positions designated as T and C, respectively. The test strips were assessed for their ability to directly detect V. cholerae O139 using samples dispersed in application buffer, and a 100 μL aliquot of sample was applied to the sample chamber. The results were observable within 20 min after application of the sample. In samples containing V. cholerae O139, the antigen was bound to the colloidal gold-conjugated MAb to form an antibody-antigen complex. This complex was captured by the MAbs at the T test line, resulting in the appearance of a reddish-purple band at the T position. The sensitivity of the test was determined to be 10⁴ cfu mL⁻¹. Direct detection of V. cholerae O139 in various fresh seafood samples could be accomplished with similar sensitivities. The detection limit was substantially improved to 1 cfu mL⁻¹ of the original bacterial content after pre-incubation of the sample in alkaline peptone water for 12 h. The V. cholerae strip test provides several advantages over other methods, including the speed and simplicity of use because there is no requirement for sophisticated equipment. Copyright © 2012 Elsevier B.V. All rights reserved.

Soil carbon changes in a wetness-prone perennial grass bioenergy field of Northeastern United States.

NASA Astrophysics Data System (ADS)

Das, S.; Thomas, R. E.; Steenhuis, T. S.; Walter, M. F.; Richards, B. K.

2015-12-01

In Northeastern United States, fallow marginal lands are being cited as a resource base for the perennial bioenergy sector. Many soils in this region are unsuitable (hence marginal) for row crop agriculture due to seasonal water saturation or near-saturation. Potential carbon (C) sequestration is a key ecosystem service of perennial bioenergy systems. The research site is a 16 acre field (42N28.20', 76W25.94') with predominantly Canaseraga-Dalton-Madalin soils, which was fallow for more than 50 years before establishment in 2011. Quadruplicate treatments have been established on test strips (~1 acre) in which soil moisture conditions vary naturally from moderately well-drained to poorly drained. 16 strip plots consist of the treatments: switchgrass, switchgrass +fertilizer N, reed canarygrass +N, and pre-existing grass as control. The N fertilization rate is 66 lb/ac. 5 permanent sampling subplots were established along the natural moisture gradient of each plot, based on initial water content measurements at the soil surface (0-12 cm) by time-domain reflectometry (TDR). Thus, 80 permanent sampling points have been established, where soil C and health parameters viz soil aggregate stability, permanganate-oxidizable (POX) carbon etc and biomass yields are sampled yearly. Frequent TDR measurements have been normalized to determine relative wetness of all 80 subplots, which have been grouped under five wetness quintiles. The driest subplots are approximately 0.8 times the field mean, whereas the wettest subplots are 1.3 times of that. After four years of establishment, the yields, % SOC (combustion method) and C/N ratios have been plotted. The decrease in % organic matter (loss on ignition) over this time for control soils, wetness quintiles 1 through 5 ranged from 2.05 ( std dev 1.9) to 1.24 (0.39), for reed canary grass soils, from3.37(1.33) to 1.59 (1.03), for switchgrass soils, from 2.67 (0.43) to 1.28 (0.91) and for switchgrass+N soils, from 2.63(0.47) to 2.07(0.39) respectively. While the wet aggregate stability of soils of all treatments through all wetness quintiles decreased, the change in POX is variable. The statistical analyses are being done.

Spatial characterization of riparian buffer effects on sediment loads from watershed systems.

PubMed

Momm, Henrique G; Bingner, Ronald L; Yuan, Yongping; Locke, Martin A; Wells, Robert R

2014-09-01

Understanding all watershed systems and their interactions is a complex, but critical, undertaking when developing practices designed to reduce topsoil loss and chemical/nutrient transport from agricultural fields. The presence of riparian buffer vegetation in agricultural landscapes can modify the characteristics of overland flow, promoting sediment deposition and nutrient filtering. Watershed simulation tools, such as the USDA-Annualized Agricultural Non-Point Source (AnnAGNPS) pollution model, typically require detailed information for each riparian buffer zone throughout the watershed describing the location, width, vegetation type, topography, and possible presence of concentrated flow paths through the riparian buffer zone. Research was conducted to develop GIS-based technology designed to spatially characterize riparian buffers and to estimate buffer efficiency in reducing sediment loads in a semiautomated fashion at watershed scale. The methodology combines modeling technology at different scales, at individual concentrated flow paths passing through the riparian zone, and at watershed scales. At the concentrated flow path scale, vegetative filter strip models are applied to estimate the sediment-trapping efficiency for each individual flow path, which are aggregated based on the watershed subdivision and used in the determination of the overall impact of the riparian vegetation at the watershed scale. This GIS-based technology is combined with AnnAGNPS to demonstrate the effect of riparian vegetation on sediment loadings from sheet and rill and ephemeral gully sources. The effects of variability in basic input parameters used to characterize riparian buffers, onto generated outputs at field scale (sediment trapping efficiency) and at watershed scale (sediment loadings from different sources) were evaluated and quantified. The AnnAGNPS riparian buffer component represents an important step in understanding and accounting for the effect of riparian vegetation, existing and/or managed, in reducing sediment loads at the watershed scale. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Application of DNA Aptamers and Quantum Dots to Lateral Flow Test Strips for Detection of Foodborne Pathogens with Improved Sensitivity versus Colloidal Gold

PubMed Central

Bruno, John G.

2014-01-01

Preliminary studies aimed at improving the sensitivity of foodborne pathogen detection via lateral flow (LF) test strips by use of high affinity DNA aptamers for capture and reporter functions when coupled to red-emitting quantum dots (Qdot 655) are reported. A variety of DNA aptamers developed against Escherichia coli, Listeria monocytogenes, and Salmonella enterica were paired in capture and reporter combinations to determine which yielded the strongest detection of their cognate bacteria using a colloidal gold screening system. Several promising sandwich combinations were identified for each of the three bacterial LF strip systems. The best E. coli aptamer-LF system was further studied and yielded a visible limit of detection (LOD) of ~3,000 E. coli 8739 and ~6,000 E. coli O157:H7 in buffer. These LODs were reduced to ~300–600 bacterial cells per test respectively by switching to a Qdot 655 aptamer-LF system. Novel aspects of these assays such as the use of high levels of detergents to avoid quantum dot agglutination and enhance migration in analytical membranes, identification of optimal analytical membrane types, UV-immobilization of capture aptamers, and novel dual biotin/digoxigenin-end labeled aptamer streptavidin-colloidal gold or -Qdot 655 conjugates plus anti-digoxigenin antibody control lines are also discussed. In general, this work provides proof-of-principle for highly sensitive aptamer-Qdot LF strip assays for rapid foodborne pathogen detection. PMID:25437803

Using satellite vegetation and compound topographic indices to map highly erodible cropland buffers for cellulosic biofuel crop developments in eastern Nebraska, USA

USGS Publications Warehouse

Gu, Yingxin; Wylie, Bruce K.

2015-01-01

Cultivating annual row crops in high topographic relief waterway buffers has negative environmental effects and can be environmentally unsustainable. Growing perennial grasses such as switchgrass (Panicum virgatum L.) for biomass (e.g., cellulosic biofuel feedstocks) instead of annual row crops in these high relief waterway buffers can improve local environmental conditions (e.g., reduce soil erosion and improve water quality through lower use of fertilizers and pesticides) and ecosystem services (e.g., minimize drought and flood impacts on production; improve wildlife habitat, plant vigor, and nitrogen retention due to post-senescence harvest for cellulosic biofuels; and serve as carbon sinks). The main objectives of this study are to: (1) identify cropland areas with high topographic relief (high runoff potentials) and high switchgrass productivity potential in eastern Nebraska that may be suitable for growing switchgrass, and (2) estimate the total switchgrass production gain from the potential biofuel areas. Results indicate that about 140,000 hectares of waterway buffers in eastern Nebraska are suitable for switchgrass development and the total annual estimated switchgrass biomass production for these suitable areas is approximately 1.2 million metric tons. The resulting map delineates high topographic relief croplands and provides useful information to land managers and biofuel plant investors to make optimal land use decisions regarding biofuel crop development and ecosystem service optimization in eastern Nebraska.

In vivo evaluation of the effect of essential oil-containing oral strips on salivary bacteria using the checkerboard method.

PubMed

da Silva, Carina Maciel; Colombo, Andréa Vieira; do Souto, Renata Martins; Colombo, Ana Paula

2005-01-01

The aim of this study was to evaluate the antimicrobial effect of essential oil-containing oral strips on different species of the oral microbiota. Saliva samples were collected from 20 subjects with good oral health, diluted and plated onto blood agar medium. The subjects were asked to place the strip (Listerine PocketPaks) on the tongue allowing it to dissolve. After 30 minutes, new saliva samples were collected again and the plates with the samples were incubated under anaerobic conditions at 37 degrees C for seven days. Colony counts (CFU/mL) were determined for each sample. The colonies on the plates were washed with 1 mL of TE buffer, and the bacterial suspensions were processed for the identification of 24 species by DNA probes and the Checkerboard DNA-DNA hybridization method. Differences in total counts, prevalence, and levels of the species evaluated before and after placement of the strips were determined by Wilcoxon sign rank and Chi-square tests. A modest increase in the total bacterial number in saliva from 1.4 x 10(8) to 1.7 x 10(8) bacterial cells was observed 30 minutes after the strip placement, although this change was not significant (p = 0.632). Most of the species reduced in frequency and/or levels, including the pathogens A. actinomycetemcomitans, C. rectus, E. corrodens, Fusobacterium spp., P. intermedia, and S. noxia, as well as the beneficial species A. meyeri, A. georgia, A. gerencseriae, A. odontolyticus, and P. acnes after strip placement. In contrast, A. viscosus, P. melaninogenica, P. gingivalis, P. micros, Streptococcus spp., T. forsythensis, and V. parvula presented an increase in prevalence and/or levels. These changes were not statistically significant after adjusting for multiple comparisons (p > 0.0022). The use of the essential oil-containing oral strips resulted in a short-term small increase in the total number of salivary microorganisms. In addition, a not significant decrease of certain periodontopathogens, and an increase in species compatible with oral health were observed.

Voltammetric analysis of N-containing drugs using the hanging galinstan drop electrode (HGDE).

PubMed

Channaa, H; Surmann, P

2009-03-01

The electrochemical behaviour of several N-containing voltammetric active drugs such as 1,4-benzodiazepines (chlordiazepoxide, nitrazepam and diazepam) as well as one nitro-compound (nitrofurantoin) and one azo-compound (phenazopyridine) is described using a new kind of liquid electrode, the hanging galinstan drop electrode. Concentrations of 10(-5) - 10(-8) mol L(-1) are generally measurable. Differential pulse and adsorptive stripping voltammograms are recorded in different supporting electrolytes, like 0.1 M KNO3, acetate buffer solution pH = 4.6 and phosphate buffer solution pH = 7.0. The effects of varying the starting potentials, U(start) for DPV and accumulation times, t(acc) for AdSV are considered. Briefly, it is shown that the novel galinstan electrode is suitable for reducing several functional groups in organic substances, here presented for N-oxide-, azomethine-, nitro- and azo-groups.

Activation of inoculum microorganism from dairy cattle feces

NASA Astrophysics Data System (ADS)

Ayuningtyas, Widya D.; Ridwan, Roni; Joni, I. M.; Marlina, E. T.; Harlia, Ellin

2018-02-01

Coal produces Coal Bed Methane (CBM) which is formed both biogenically and thermogenically. Lignite is not utilized optimally because it has low heat content and productivity time limit that decreases CBM production. In order to utilize lignite waste, adding inoculum consortium microorganism from dairy cattle waste as starter for biogas process can be a solution. This study aimed to produce inoculum consortium microorganism as biogas starter from dairy cattle feces through in vitro activation process by Theoudorou modification method. The research used complete randomized design with 3 replications. The treatments were blank (R0), 100% concentrate (R1), 70% concentrate+30% grass (R2), 70% grass+30% concentrate (R3) and 100% grass (R4). All treatments were added by buffer solution and feces with ratio of 2:1 into 100 ml serum injection bottle with anaerobic conditions. The parameters observed were gas production, pH and gas kinetics (orskov's equation) for 2, 4, 6, 8, 10, 12, 24 and 48 hours. The results showed that the treatment had significant effect (P <0.05) on the observed parameters. The highest total gas production was for R2 and R3 treatments with total production of 91.17 ml and 101.17 ml, pH (6.62 and 6.57), maximum gas production (94.03 and 97.62 ml), speed of gas production (0.066 and 0.084 ml/hour). There is not a significant difference for both the treatments. The source of inoculum consortium microorganisms for biogas starter selected based on the observed parameters and potential availability of proteolytic and fibrocytic microorganisms is R2 (70% concentrate +30% grass).

Nitrous oxide emission from cropland and adjacent riparian buffers in contrasting hydrogeomorphic settings.

PubMed

Fisher, K; Jacinthe, P A; Vidon, P; Liu, X; Baker, M E

2014-01-01

Riparian buffers are important nitrate (NO) sinks in agricultural watersheds, but limited information is available regarding the intensity and control of nitrous oxide (NO) emission from these buffers. This study monitored (December 2009-May 2011) NO fluxes at two agricultural riparian buffers in the White River watershed in Indiana to assess the impact of land use and hydrogeomorphologic (HGM) attributes on emission. The study sites included a riparian forest in a glacial outwash/alluvium setting (White River [WR]) and a grassed riparian buffer in tile-drained till plains (Leary Weber Ditch [LWD]). Adjacent corn ( L.) fields were monitored for land use assessment. Analysis of variance identified season, land use (riparian buffer vs. crop field), and site geomorphology as major drivers of NO fluxes. Strong relationships between N mineralization and NO fluxes were found at both sites, but relationships with other nutrient cycling indicators (C/N ratio, dissolved organic C, microbial biomass C) were detected only at LWD. Nitrous oxide emission showed strong seasonal variability; the largest NO peaks occurred in late spring/early summer as a result of flooding at the WR riparian buffer (up to 27.8 mg NO-N m d) and N fertilizer application to crop fields. Annual NO emission (kg NO-N ha) was higher in the crop fields (WR: 7.82; LWD: 6.37) than in the riparian areas. A significant difference ( < 0.02) in annual NO emission between the riparian buffers was detected (4.32 vs. 1.03 kg NO-N ha at WR and LWD, respectively), and this difference was attributed to site geomorphology and flooding (WR is flood prone; no flooding occurred at tile-drained LWD). The study results demonstrate the significance of landscape geomorphology and land-stream connection (i.e., flood potential) as drivers of NO emission in riparian buffers and therefore argue that an HGM-based approach should be especially suitable for determination of regional NO budget in riparian ecosystems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Climate regulation, energy provisioning and water purification: Quantifying ecosystem service delivery of bioenergy willow grown on riparian buffer zones using life cycle assessment.

PubMed

Styles, David; Börjesson, Pål; D'Hertefeldt, Tina; Birkhofer, Klaus; Dauber, Jens; Adams, Paul; Patil, Sopan; Pagella, Tim; Pettersson, Lars B; Peck, Philip; Vaneeckhaute, Céline; Rosenqvist, Håkan

2016-12-01

Whilst life cycle assessment (LCA) boundaries are expanded to account for negative indirect consequences of bioenergy such as indirect land use change (ILUC), ecosystem services such as water purification sometimes delivered by perennial bioenergy crops are typically neglected in LCA studies. Consequential LCA was applied to evaluate the significance of nutrient interception and retention on the environmental balance of unfertilised energy willow planted on 50-m riparian buffer strips and drainage filtration zones in the Skåne region of Sweden. Excluding possible ILUC effects and considering oil heat substitution, strategically planted filter willow can achieve net global warming potential (GWP) and eutrophication potential (EP) savings of up to 11.9 Mg CO 2 e and 47 kg PO 4 e ha -1 year -1 , respectively, compared with a GWP saving of 14.8 Mg CO 2 e ha -1 year -1 and an EP increase of 7 kg PO 4 e ha -1 year -1 for fertilised willow. Planting willow on appropriate buffer and filter zones throughout Skåne could avoid 626 Mg year -1 PO 4 e nutrient loading to waters.

Comparison of fractionation methods for nitrogen and starch in maize and grass silages.

PubMed

Ali, M; de Jonge, L H; Cone, J W; van Duinkerken, G; Blok, M C; Bruinenberg, M H; Hendriks, W H

2016-06-01

In in situ nylon bag technique, many feed evaluation systems use a washing machine method (WMM) to determine the washout (W) fraction and to wash the rumen incubated nylon bags. As this method has some disadvantages, an alternate modified method (MM) was recently introduced. The aim of this study was to determine and compare the W and non-washout (D+U) fractions of nitrogen (N) and/or starch of maize and grass silages, using the WMM and the MM. Ninety-nine maize silage and 99 grass silage samples were selected with a broad range in chemical composition. The results showed a large range in the W, soluble (S) and D+U fractions of N of maize and grass silages and the W, insoluble washout (W-S) and D+U fractions of starch of maize silages, determined by both methods, due to variation in their chemical composition. The values for N fractions of maize and grass silages obtained with both methods were found different (p < 0.001). Large differences (p < 0.001) were found in the D+U fraction of starch of maize silages which might be due to different methodological approaches, such as different rinsing procedures (washing vs. shaking), duration of rinsing (40 min vs. 60 min) and different solvents (water vs. buffer solution). The large differences (p < 0.001) in the W-S and D+U fractions of starch determined with both methods can led to different predicted values for the effective rumen starch degradability. In conclusion, the MM with one recommended shaking procedure, performed under identical and controlled experimental conditions, can give more reliable results compared to the WMM, using different washing programs and procedures. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.

Voltammetric determination of mixtures of caffeine and chlorogenic acid in beverage samples using a boron-doped diamond electrode.

PubMed

Yardım, Yavuz; Keskin, Ertugrul; Şentürk, Zühre

2013-11-15

Herein, a boron-doped diamond (BDD) electrode that is anodically pretreated was used for the simultaneous determination of caffeine (CAF) and chlorogenic acid (CGA) by cyclic and adsorptive stripping voltammetry. The dependence of peak current and potential on pH, scan rate, accumulation parameters and other experimental variables were studied. By using square-wave stripping mode after 60 s accumulation under open-circuit voltage, the BDD electrode was able to separate the oxidation peak potentials of CAF and CGA present in binary mixtures by about 0.4V in Britton-Robinson buffer at pH 1.0. The limits of detection were 0.107 µg mL(-1) (5.51×10(-7) M) for CAF, and 0.448 µg mL(-1) (1.26×10(-6) M) for CGA. The practical applicability of this methodology was tested in commercially available beverage samples. © 2013 Elsevier B.V. All rights reserved.

Evaluating grass strips trapping efficiency of sediments and herbicides

NASA Astrophysics Data System (ADS)

Burguet, Maria; Guzmán, Gema; de Luna, Elena; Taguas, Encarnación V.; Gómez, José Alfonso

2016-04-01

Water erosion and associated offsite contamination are major environmental risks in many Mediterranean crops such as olives or vineyards (Beaufoy, 2001; Gómez et al., 2011). The use of cover crops has been prescribed as a mitigation measure for both problems because permanent cover crops have demonstrated to reduce sediment and agrochemical loads (e.g. Gómez, 2009a, b). However, large uncertainty remains about its effectiveness degree to reduce sediment and agrochemical contribution to streams due to the limited number of available studies, and the large variability observed under field conditions (Taguas et al., 2012). Furthermore, the determination of sediment and herbicide sources using suitable sediment tracing/fingerprinting properties has been noted as one tool to evaluate the effectiveness and functioning of vegetated filters at the catchment scale (Koiter et al., 2013). The objectives of the present study were twofold: [1] to explore the combined use of natural and simulated rainfall and magnetic iron oxide in understanding the performance of vegetation strips on runoff and soil and herbicide losses at plot scale and, [2] to evaluate the effectiveness degree of vegetation strips in buffering sediment and herbicide from bare soil areas under different conditions compared to a control situation with no strips. This study encompasses six rainfall simulations under four different soil managements combining the use of a magnetic iron oxide as a sediment tracer to obtain a better understanding of the vegetation strips trapping efficiency. Three runoff plots of 6 m × 14 m were established in a 20% hillslope under a Fluvisol alluvial terrace. Each of the plots contained three bare strips tagged with magnetic iron oxide and three strips with Lolium multiflorum L. The soil management simulated scenarios were: immediately after sowing the vegetation cover (June 2011cover crop), with settled vegetation cover (June 2012cover crop), after 5 cm of deep ploughing (October 2013freshly tilled) and after ploughing and mechanically compacting the soil with a sheet metal (November 2013 consolidated surface). Our results indicate that by using cover crop strips, runoff and sediment losses were approximately 50 % and 12 % respectively lower than the measured values in bare consolidated and freshly tilled soil. The formation of microrelief steps after the first simulation also helped to reduce soil losses and runoff. Ploughed and compacted soil management showed the highest cumulative runoff and soil losses values (28 mm and 15 kg). Evident tracer selectivity from small particle size soil textures (clays) was observed as there was an enrichment of these particles in the collected sediment. These features contribute to explain the effects of the management and the vegetation on the sediment distribution in the hillslopes and must be taken into account when performing tracing studies as well as when using cover crop strips to mitigate offsite contamination by agrochemicals. Acknowledgements: The authors would like to thank Clemente Trujillo, Manuel Redondo and Azahara Ramos for their full help and support during the fieldwork. This study was supported by the Project P08-AGR-03925 (Andalusian Government), AGL2009-12936-C03-01 (Ministry of Science and Innovation), RESEL (Ministry of Agriculture, Food and Environment) and FEDER fund. The program JAE of the National Spanish Research Centre which provided grant support for the PhD project of the corresponding author is also thanked. References: Beaufoy, G. 2001. EU policies for olive farming. Unsustainable on all counts. BirdLife Internacional-WWF, Brussels. Gómez, J.A., Sobrinho, T.A, Giráldez, J.V., Fereres, E. 2009a. Soil management effects on runoff, erosion and soil properties in an olive grove of Southern Spain. Soil & Tillage Research 102: 5-13. Gómez, J.A., Guzmán, M.G., Giráldez, J.V., Fereres, E. 2009b. The influence of cover crops and tillage on water and sediment yield, and on nutrient, and organic matter losses in an olive orchard on a sandy loam soil. Soil Till Res 106: 137-144. Gómez, J.A., Llewellyn, C., Basch, G., Sutton, P. B., Dyson, J. S., Jones, C. A. 2011. The effects of cover crops and conventional tillage on soil and runoff loss in vineyards and olive groves in several Mediterranean countries. Soil Use and Management 27: 502 - 514. Koiter, A.J., Owens, P.N., Petticrew, E.L., Lobb, D.A. 2013. The behavioural characteristics of sediment properties and their implications for sediment fingerprinting as an approach for identifying sediment sources in river basins. Earth-Science Reviews 125: 24-42. Taguas, E.V., Burguet, M., Pérez, R., Ayuso, J.L., Gómez, J.A., 2012. Interpretation of the impact of different managements and the rainfall variability on the soil erosion in a Mediterranean olive orchard microcatchment. Geophysical Research Abstracts 14, EGU2012-10966.

Fog, plant leaves and deposition of droplets

NASA Astrophysics Data System (ADS)

Konrad, W.; Ebner, M.; Traiser, C.; Roth-Nebelsick, A.

2010-07-01

For various plants and animals, the accumulation of fog or dew droplets constitutes an essential part of their water supply. Understanding how water droplets deposited by fog or dew events interact with plant or animal surfaces is essential for gaining insight into the functionality of these surfaces. Besides being interesting within the realm of biology, this knowledge is indispensable for technical applications. Frequently, it is advantageous to know (i) the growth rate of a droplet attached by surface tension to a surface which grows due to a given influx of fog particles, (ii) the maximum volume and (iii) the "lifespan" of a droplet before it detaches from the surface or starts to slide down along the plant surface, driven by gravity. Starting from principles of physics, we calculate quantitative expressions addressing questions (i) to (iii) for droplets which are attached to surfaces characterised by a high degree of symmetry, such as horizontally oriented or inclined planes, sections of spheres, cones and rotationally symmetric crevices. Furthermore, we treat the behaviour of droplets attached to a surface of non-constant contact angle. Although real surfaces never meet their geometric idealisations, results based on these often represent suitable and useful approximations to reality. Finally, we apply our results to Stipagrostis sabulicola, a dune grass of the Namib desert which satisfies its water demand solely by capturing fog and dew droplets. Pictures taken with a scanning electron microscope show that the stem of S. sabulicola is longitudinally built up by alternating elevated and countersunk strips. Filling gaps in the experimental observation with theoretical speculation, the following picture emerges: Assuming that the elevated strips exhibit a higher contact angle than the countersunk strips, water droplets being deposited on the elevated strips are drawn towards the latter. The lower contact angle which prevails there increases the droplets' contact area with the plant surface at the expense of their thickness, thus expediting coalescence with neighbouring droplets. Once the droplets have grown to the critical size at which surface tension is overcome by gravitational attraction, the countersunk strips act as drainlike channels guiding the sliding droplets towards the basis of the stem and the roots.

Reducing sediment inputs to Scottish streams: a review of the efficacy of soil conservation practices in upland forestry.

PubMed

Carling, P A; Irvine, B J; Hill, A; Wood, M

2001-01-29

The historical process by which a soil conservation strategy has evolved within the UK forestry industry is briefly reviewed. Particular attention is given to the development of practical and effective guidelines to prevent both soil damage and sediment entering water courses. It is concluded that the 'Forest and Water Guidelines', together with other forest industry manuals, largely provide adequate protection for aquatic habitats from pre-afforestation cultivation and from harvesting activities. The problem of soil erosion owing to ploughing of open furrows has largely been obviated by improved drainage network design coupled with the use of vegetated buffer strips and sediment catchpits. Alternative site preparation techniques, such as 'moling' or 'dolloping' of afforestation sites, are now preferred. However, the effects on slope hydrology and the improved soil conservation associated with these methods require quantifying. Additional understanding of effective buffer strip function, for example, on a variety of slope angles, soil types and vegetation associations would be beneficial. The design of forest roads and the associated network of drains, culverts and sediment catchpits is addressed in forestry guidelines. Future potential in this area may involve the use of Geographical Information Systems in the effective design of road networks which minimise adverse effects on slope hydrology. Similarly computer simulation of flow routing might aid in the design of road drain networks. At the more local scale there remains scope for further research aimed at minimising soil disturbance by machinery. Consideration should also be given to the long-term sustainability of the soil structure through second and subsequent crop rotations.

Spatial optimization of watershed management practices for nitrogen load reduction using a modeling-optimization framework.

PubMed

Yang, Guoxiang; Best, Elly P H

2015-09-15

Best management practices (BMPs) can be used effectively to reduce nutrient loads transported from non-point sources to receiving water bodies. However, methodologies of BMP selection and placement in a cost-effective way are needed to assist watershed management planners and stakeholders. We developed a novel modeling-optimization framework that can be used to find cost-effective solutions of BMP placement to attain nutrient load reduction targets. This was accomplished by integrating a GIS-based BMP siting method, a WQM-TMDL-N modeling approach to estimate total nitrogen (TN) loading, and a multi-objective optimization algorithm. Wetland restoration and buffer strip implementation were the two BMP categories used to explore the performance of this framework, both differing greatly in complexity of spatial analysis for site identification. Minimizing TN load and BMP cost were the two objective functions for the optimization process. The performance of this framework was demonstrated in the Tippecanoe River watershed, Indiana, USA. Optimized scenario-based load reduction indicated that the wetland subset selected by the minimum scenario had the greatest N removal efficiency. Buffer strips were more effective for load removal than wetlands. The optimized solutions provided a range of trade-offs between the two objective functions for both BMPs. This framework can be expanded conveniently to a regional scale because the NHDPlus catchment serves as its spatial computational unit. The present study demonstrated the potential of this framework to find cost-effective solutions to meet a water quality target, such as a 20% TN load reduction, under different conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

The impact of inter-annual rainfall variability on African savannas changes with mean rainfall.

PubMed

Synodinos, Alexis D; Tietjen, Britta; Lohmann, Dirk; Jeltsch, Florian

2018-01-21

Savannas are mixed tree-grass ecosystems whose dynamics are predominantly regulated by resource competition and the temporal variability in climatic and environmental factors such as rainfall and fire. Hence, increasing inter-annual rainfall variability due to climate change could have a significant impact on savannas. To investigate this, we used an ecohydrological model of stochastic differential equations and simulated African savanna dynamics along a gradient of mean annual rainfall (520-780 mm/year) for a range of inter-annual rainfall variabilities. Our simulations produced alternative states of grassland and savanna across the mean rainfall gradient. Increasing inter-annual variability had a negative effect on the savanna state under dry conditions (520 mm/year), and a positive effect under moister conditions (580-780 mm/year). The former resulted from the net negative effect of dry and wet extremes on trees. In semi-arid conditions (520 mm/year), dry extremes caused a loss of tree cover, which could not be recovered during wet extremes because of strong resource competition and the increased frequency of fires. At high mean rainfall (780 mm/year), increased variability enhanced savanna resilience. Here, resources were no longer limiting and the slow tree dynamics buffered against variability by maintaining a stable population during 'dry' extremes, providing the basis for growth during wet extremes. Simultaneously, high rainfall years had a weak marginal benefit on grass cover due to density-regulation and grazing. Our results suggest that the effects of the slow tree and fast grass dynamics on tree-grass interactions will become a major determinant of the savanna vegetation composition with increasing rainfall variability. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impacts of hydraulic redistribution on overstory-understory interactions in a semiarid savanna

NASA Astrophysics Data System (ADS)

Barron-Gafford, G.; Minor, R. L.; Hendryx, S.; Lee, E.; Sutter, L., Jr.; Colella, A.; Murphy, P.; Sanchez-Canete, E. P.; Hamerlynck, E. P.; Kumar, P.; Scott, R. L.

2016-12-01

Hydraulic redistribution (HR) is an important ecohydrological process in dryland environments by which plants preferentially move water from wet to dry soil layers. How does this water movement by the overstory influence physiological activity in the understory? Are there periods of facilitation when the tree is lifting water and periods of competition when the water is being moved deeper in the profile? We combined trunk, lateral root, and taproot sap flow data, and linked these measures with shallow and deep soil moisture data to show that soil moisture gradients control hydraulic redistribution in overstory mesquite trees. During prolonged inter-rain periods of drought and in response to periods of high vapor pressure deficits, mesquites drew upon this deeper, stored water to meet biological demands. We created plots under mesquite that experienced HR and plots where HR was physically prohibited to quantify the impacts of HR on understory performance. We measured carbon and water exchange at the leaf-level on mesquite and understory grass and for entire understory ecosystem using a large, portable chamber. We found that HR provided a drought-buffering capacity for the overstory mesquite and a significant decrease in mesquite photosynthesis in trees where the capacity for HR was reduced. While we had hypothesized that water lifted by the mesquite in periods of drought would facilitate understory grass function, we found no evidence for this. In fact, we found that grasses actually conducted higher rates of photosynthesis in plots where HR was eliminated. Ultimately, we found that HR in upland savannas, where there is little to no access to deep water, yields a competitive interaction between overstory mesquites and understory grasses at the scale of individual precipitation pulse events and across entire growing seasons.

/sup 45/Ca distribution and transport in saponin skinned vascular smooth muscle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stout, M.A.; Diecke, F.P.

1983-04-01

/sup 45/Ca distribution and transport were studied in chemically skinned strips of caudal artery from Kyoto Wistar rats. Sarcolemmal membranes were made hyperpermeable by exposure for 60 min to solutions containing 0.1 mg/ml of saponin. Skinned helical strips responded with graded contractions to changes in ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid buffered free Ca solutions (10(-7) to 10(-5) M) and were sensitive to the Mg-ATP concentration. Tissues loaded in the presence of 10(-7) M Ca contracted in response to 10 mM caffeine. These experiments indicate the strips are skinned and possess a functional regulatory and contractile system and an intact Camore » sequestering system. /sup 45/Ca distributes in three compartments in skinned caudal artery strips. The Ca contents of two components are linear functions of the Ca-ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid concentration and desaturate at rapid rates. They correspond to the extracellular and cytoplasmic spaces. A significantly smaller component releases Ca at comparatively slower rates. /sup 45/Ca uptake by the slow component consists of an ATP-dependent and an ATP-independent fraction. The /sup 45/Ca content of the ATP-dependent fraction is a function of the free Ca concentration and is independent of the Ca-ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid concentration. Its content was enhanced by oxalate and was abolished by Triton X-100 skinning solutions. The ATP-independent component was not affected by Triton X-100 skinning and may represent Ca binding to cytoplasmic molecules and structures. The sequestered Ca was released with caffeine or Ca but not by epinephrine. The observations indicate that the sarcoplasmic reticulum and mitochondria of vascular smooth muscle strips skinned with saponin retain their functional integrity after saponin skinning.« less

Contamination with ergot bodies (Claviceps purpurea sensu lato) of two horse pastures in Northern Germany.

PubMed

Aboling, S; Drotleff, A M; Cappai, M G; Kamphues, J

2016-11-01

Because the occurrence of Claviceps in European pastures may have been overlooked to cause serious health problem for grazing animals, we documented the degree of Claviceps contamination in two horse pastures and estimated whether the horses could have ingested a critical quantity of alkaloids. We counted the Claviceps sclerotia and determined alkaloid levels using high performance liquid chromatography with fluorescence detection. Depending on the location, the number of sclerotia varied from 0.09 to 0.19 per square meter (central area) and from 0.23 to 55.8 per square meter (border strips). Alkaloid levels in individual sclerotia also varied in different genera of grasses, ranging from 0.98 ± 0.17 μg/kg in Agrostis sp. to 25.82 ± 9.73 μg/kg in Dactylis sp., equivalent to 0.98 μg/kg and 7.26 mg/kg. Sclerotia from Dactylis contained high levels of ergosine (0.209 % ± 0.100 %) and ergocristine (0.374 % ± 0.070 %). Depending on the localization in pastures, alkaloid levels in forage (dry matter, DM) ranged from 16.1 to 45.4 μg/kg in central areas and from 23.9 to 722 μg/kg in border strips. The amount of alkaloids that a horse could have ingested depended on its daily DM uptake, which was higher in the central areas (5.85 kg/day) than in the border strips (2.73 or 0.78 kg/day). In the central areas, this amount of alkaloids ranged from 94.2 to 265.9 μg/day; and in the border strips, from 65.3 (in 2.73 kg DM/day) to as much as 563.8 μg/day (in 0.78 kg DM/day). All these amounts are higher than the European averages for alkaloids ingested by horses via feedstuffs.

Organic farming benefits local plant diversity in vineyard farms located in intensive agricultural landscapes.

PubMed

Nascimbene, Juri; Marini, Lorenzo; Paoletti, Maurizio G

2012-05-01

The majority of research on organic farming has considered arable and grassland farming systems in Central and Northern Europe, whilst only a few studies have been carried out in Mediterranean agro-systems, such as vineyards, despite their economic importance. The main aim of the study was to test whether organic farming enhances local plant species richness in both crop and non-crop areas of vineyard farms located in intensive conventional landscapes. Nine conventional and nine organic farms were selected in an intensively cultivated region (i.e. no gradient in landscape composition) in northern Italy. In each farm, vascular plants were sampled in one vineyard and in two non-crop linear habitats, grass strips and hedgerows, adjacent to vineyards and therefore potentially influenced by farming. We used linear mixed models to test the effect of farming, and species longevity (annual vs. perennial) separately for the three habitat types. In our intensive agricultural landscapes organic farming promoted local plant species richness in vineyard fields, and grassland strips while we found no effect for linear hedgerows. Differences in species richness were not associated to differences in species composition, indicating that similar plant communities were hosted in vineyard farms independently of the management type. This negative effect of conventional farming was probably due to the use of herbicides, while mechanical operations and mowing regime did not differ between organic and conventional farms. In grassland strips, and only marginally in vineyards, we found that the positive effect of organic farming was more pronounced for perennial than annual species.

Effects of buffers on milk fatty acids and mammary arteriovenous differences in dairy cows fed Ca salts of fatty acids.

PubMed

Thivierge, M C; Chouinard, P Y; Lévesque, J; Girard, V; Seoane, J R; Brisson, G J

1998-07-01

Ten Holstein cows in early lactation were used in a replicated 5 x 5 Latin square design to study the effects of MgO and three buffers added to diets containing Ca salts of canola oil fatty acids. Treatments were 1) control (basal diet; no buffer). 2) 1.1% NaHCO3 plus 1.1% KHCO3, 3) 1.9% NaHCO3, 4) 0.5% MgO, and 5) 2.0% Na sesquicarbonate (percentage of dry matter). The control diet contained 53% grass silage, 43% concentrate, and 4% Ca salts. Body weight, intake, milk yield, and percentages of milk fat, protein, and lactose were unaffected by treatments. Buffers and MgO tended to increase triacylglycerol extraction by the mammary gland and changed the proportions of some fatty acids in milk. Arterial concentrations of acetate and triacylglycerol were correlated with their respective arteriovenous differences. Extraction by the mammary gland was high for acetate (approximately equal to 58.2%), triacylglycerol (approximately equal to 47.3%) propionate (approximately equal to 34.6%), and glucose (approximately equal to 24.3%). Extraction of free fatty acids, phospholipids, or cholesterol was negligible. Mammary triacylglycerol arteriovenous difference tended to be higher than when MgO was fed than when NaHCO3 was fed. Sodium sesquicarbonate, NaHCO3, and the blend of bicarbonate buffers increased C18:2 in milk fat when compared with the control treatment. The concentration of C18:2 in milk fat decreased when MgO was fed, but the ratio of cis-C18:1 to trans-C18:1 increased compared with effects of dietary NaHCO3. Medium-chain fatty acids in milk fat tended to be higher than Na sesquicarbonate than with NaHCO3. Buffers and MgO modified the profiles of fatty acids in milk.

The buffering capacity of stems: genetic architecture of nonstructural carbohydrates in cultivated Asian rice, Oryza sativa.

PubMed

Wang, Diane R; Han, Rongkui; Wolfrum, Edward J; McCouch, Susan R

2017-07-01

Harnessing stem carbohydrate dynamics in grasses offers an opportunity to help meet future demands for plant-based food, fiber and fuel production, but requires a greater understanding of the genetic controls that govern the synthesis, interconversion and transport of such energy reserves. We map out a blueprint of the genetic architecture of rice (Oryza sativa) stem nonstructural carbohydrates (NSC) at two critical developmental time-points using a subpopulation-specific genome-wide association approach on two diverse germplasm panels followed by quantitative trait loci (QTL) mapping in a biparental population. Overall, 26 QTL are identified; three are detected in multiple panels and are associated with starch-at-maturity, sucrose-at-maturity and NSC-at-heading. They tag OsHXK6 (rice hexokinase), ISA2 (rice isoamylase) and a tandem array of sugar transporters. This study provides the foundation for more in-depth molecular investigation to validate candidate genes underlying rice stem NSC and informs future comparative studies in other agronomically vital grass species. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

The buffering capacity of stems: genetic architecture of nonstructural carbohydrates in cultivated Asian rice, Oryza sativa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Diane R.; Han, Rongkui; Wolfrum, Edward J.

Harnessing stem carbohydrate dynamics in grasses offers an opportunity to help meet future demands for plant-based food, fiber and fuel production, but requires a greater understanding of the genetic controls that govern the synthesis, interconversion and transport of such energy reserves. We map out a blueprint of the genetic architecture of rice ( Oryza sativa) stem nonstructural carbohydrates (NSC) at two critical developmental time-points using a subpopulation-specific genome-wide association approach on two diverse germplasm panels followed by quantitative trait loci (QTL) mapping in a biparental population. Overall, 26 QTL are identified; three are detected in multiple panels and are associatedmore » with starch-at-maturity, sucrose-at-maturity and NSC-at-heading. They tag OsHXK6 (rice hexokinase), ISA2 (rice isoamylase) and a tandem array of sugar transporters. Furthermore, this study provides the foundation for more in-depth molecular investigation to validate candidate genes underlying rice stem NSC and informs future comparative studies in other agronomically vital grass species.« less

The buffering capacity of stems: genetic architecture of nonstructural carbohydrates in cultivated Asian rice, Oryza sativa

DOE PAGES

Wang, Diane R.; Han, Rongkui; Wolfrum, Edward J.; ...

2017-05-30

Harnessing stem carbohydrate dynamics in grasses offers an opportunity to help meet future demands for plant-based food, fiber and fuel production, but requires a greater understanding of the genetic controls that govern the synthesis, interconversion and transport of such energy reserves. We map out a blueprint of the genetic architecture of rice ( Oryza sativa) stem nonstructural carbohydrates (NSC) at two critical developmental time-points using a subpopulation-specific genome-wide association approach on two diverse germplasm panels followed by quantitative trait loci (QTL) mapping in a biparental population. Overall, 26 QTL are identified; three are detected in multiple panels and are associatedmore » with starch-at-maturity, sucrose-at-maturity and NSC-at-heading. They tag OsHXK6 (rice hexokinase), ISA2 (rice isoamylase) and a tandem array of sugar transporters. Furthermore, this study provides the foundation for more in-depth molecular investigation to validate candidate genes underlying rice stem NSC and informs future comparative studies in other agronomically vital grass species.« less

Ultra-high-performance liquid chromatography-tandem mass spectrometry measurement of climbazole deposition from hair care products onto artificial skin and human scalp.

PubMed

Chen, Guoqiang; Hoptroff, Michael; Fei, Xiaoqing; Su, Ya; Janssen, Hans-Gerd

2013-11-22

A sensitive and specific ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the measurement of climbazole deposition from hair care products onto artificial skin and human scalp. Deuterated climbazole was used as the internal standard. Atmospheric pressure chemical ionization (APCI) in positive mode was applied for the detection of climbazole. For quantification, multiple reaction monitoring (MRM) transition 293.0>69.0 was monitored for climbazole, and MRM transition 296.0>225.1 for the deuterated climbazole. The linear range ran from 4 to 2000 ng mL(-1). The limit of detection (LOD) and the limit of quantification (LOQ) were 1 ng mL(-1) and 4 ng mL(-1), respectively, which enabled quantification of climbazole on artificial skin and human scalp at ppb level (corresponding to 16 ng cm(-2)). For the sampling of climbazole from human scalp the buffer scrub method using a surfactant-modified phosphate buffered saline (PBS) solution was selected based on a performance comparison of tape stripping, the buffer scrub method and solvent extraction in in vitro studies. Using this method, climbazole deposition in in vitro and in vivo studies was successfully quantified. Copyright © 2013 Elsevier B.V. All rights reserved.

Smart maintenance of riverbanks using a standard data layer and Augmented Reality

NASA Astrophysics Data System (ADS)

Pierdicca, Roberto; Frontoni, Emanuele; Zingaretti, Primo; Mancini, Adriano; Malinverni, Eva Savina; Tassetti, Anna Nora; Marcheggiani, Ernesto; Galli, Andrea

2016-10-01

Linear buffer strips (BS) along watercourses are commonly adopted to reduce run-off, accumulation of bank-top sediments and the leaking of pesticides into fresh-waters, which strongly increase water pollution. However, the monitoring of their conditions is a difficult task because they are scattered over wide rural areas. This work demonstrates the benefits of using a standard data layer and Augmented Reality (AR) in watershed control and outlines the guideline of a novel approach for the health-check of linear BS. We designed a mobile environmental monitoring system for smart maintenance of riverbanks by embedding the AR technology within a Geographical Information System (GIS). From the technological point of view, the system's architecture consists of a cloud-based service for data sharing, using a standard data layer, and of a mobile device provided with a GPS based AR engine for augmented data visualization. The proposed solution aims to ease the overall inspection process by reducing the time required to run a survey. Indeed, ordinary operational survey conditions are usually performed basing the fieldwork on just classical digitized maps. Our application proposes to enrich inspections by superimposing information on the device screen with the same point of view of the camera, providing an intuitive visualization of buffer strip location. This way, the inspection officer can quickly and dynamically access relevant information overlaying geographic features, comments and other contents in real time. The solution has been tested in fieldwork to prove at what extent this cutting-edge technology contributes to an effective monitoring over large territorial settings. The aim is to encourage officers, land managers and practitioners toward more effective monitoring and management practices.

Determination of allura red in some food samples by adsorptive stripping voltammetry.

PubMed

Alghamdi, Ahmad H

2005-01-01

Square wave (SW) voltammetry was used to explore the adsorption properties of the food additive dye Allura Red on a hanging mercury drop electrode (HMDE). By using the adsorptive stripping voltammetric approach, we developed a sensitive electroanalytical method for the determination of this azo dye. A well-developed voltammetric peak probably related to the cathodic reduction of the azo moiety was obtained in pH 9 Britton-Robinson (B-R) buffer at 613 mV. Cyclic voltammetric studies indicated that the reduction process was irreversible and primarily controlled by adsorption. The adsorptive voltammetric signal was evaluated with respect to various experimental conditions; the optimized values were supporting electrolyte, B-R buffer; pH 11; accumulation time, 180 s; accumulation potential, 0.0 V; scan rate, 900 mV/s; pulse amplitude, 75 mV; and SW frequency, 90 Hz. Adsorptive voltammetric peak current showed a linear response for Allura Red in the concentration range of 2.5 x 10(-8) to 2.0 x 10(-7) mol/L (r = 0.998). The limit of detection was 8.5 x 10(-9) mol/L (4.2 ng/mL), the precision in terms of relative standard deviation was 1.3%, and the mean recovery was 102%. Possible interferences by several substances usually present in food products such as food additive azo dyes (E110, E102), gelatin, natural and artificial sweeteners, preservatives, and antioxidants were also evaluated. The proposed electrochemical procedure was successfully applied to the determination of this food dye in commercially available candy and a soft drink. The results were compared by statistical evaluation with those obtained by a reference spectrophotometric method.

The effects of catchment and riparian forest quality on stream environmental conditions across a tropical rainforest and oil palm landscape in Malaysian Borneo.

PubMed

Luke, Sarah H; Barclay, Holly; Bidin, Kawi; Chey, Vun Khen; Ewers, Robert M; Foster, William A; Nainar, Anand; Pfeifer, Marion; Reynolds, Glen; Turner, Edgar C; Walsh, Rory P D; Aldridge, David C

2017-06-01

Freshwaters provide valuable habitat and important ecosystem services but are threatened worldwide by habitat loss and degradation. In Southeast Asia, rainforest streams are particularly threatened by logging and conversion to oil palm, but we lack information on the impacts of this on freshwater environmental conditions, and the relative importance of catchment versus riparian-scale disturbance. We studied 16 streams in Sabah, Borneo, including old-growth forest, logged forest, and oil palm sites. We assessed forest quality in riparian zones and across the whole catchment and compared it with stream environmental conditions including water quality, structural complexity, and organic inputs. We found that streams with the highest riparian forest quality were nearly 4 °C cooler, over 20 cm deeper, had over 40% less sand, greater canopy cover, more stored leaf litter, and wider channels than oil palm streams with the lowest riparian forest quality. Other variables were significantly related to catchment-scale forest quality, with streams in the highest quality forest catchments having 40% more bedrock and 20 times more dead wood, along with higher phosphorus, and lower nitrate-N levels compared to streams with the lowest catchment-scale forest quality. Although riparian buffer strips went some way to protecting waterways, they did not maintain fully forest-like stream conditions. In addition, logged forest streams still showed signs of disturbance 10-15 years after selective logging. Our results suggest that maintenance and restoration of buffer strips can help to protect healthy freshwater ecosystems but logging practices and catchment-scale forest management also need to be considered.

The effects of catchment and riparian forest quality on stream environmental conditions across a tropical rainforest and oil palm landscape in Malaysian Borneo

PubMed Central

Barclay, Holly; Bidin, Kawi; Chey, Vun Khen; Ewers, Robert M.; Foster, William A.; Nainar, Anand; Pfeifer, Marion; Reynolds, Glen; Turner, Edgar C.; Walsh, Rory P. D.; Aldridge, David C.

2017-01-01

Abstract Freshwaters provide valuable habitat and important ecosystem services but are threatened worldwide by habitat loss and degradation. In Southeast Asia, rainforest streams are particularly threatened by logging and conversion to oil palm, but we lack information on the impacts of this on freshwater environmental conditions, and the relative importance of catchment versus riparian‐scale disturbance. We studied 16 streams in Sabah, Borneo, including old‐growth forest, logged forest, and oil palm sites. We assessed forest quality in riparian zones and across the whole catchment and compared it with stream environmental conditions including water quality, structural complexity, and organic inputs. We found that streams with the highest riparian forest quality were nearly 4 °C cooler, over 20 cm deeper, had over 40% less sand, greater canopy cover, more stored leaf litter, and wider channels than oil palm streams with the lowest riparian forest quality. Other variables were significantly related to catchment‐scale forest quality, with streams in the highest quality forest catchments having 40% more bedrock and 20 times more dead wood, along with higher phosphorus, and lower nitrate‐N levels compared to streams with the lowest catchment‐scale forest quality. Although riparian buffer strips went some way to protecting waterways, they did not maintain fully forest‐like stream conditions. In addition, logged forest streams still showed signs of disturbance 10–15 years after selective logging. Our results suggest that maintenance and restoration of buffer strips can help to protect healthy freshwater ecosystems but logging practices and catchment‐scale forest management also need to be considered. PMID:28706573

Herbaceous or Salix miyabeana 'SX64' narrow buffer strips as a means to minimize glyphosate and aminomethylphosphonic acid leaching from row crop fields.

PubMed

Hénault-Ethier, Louise; Lucotte, Marc; Moingt, Matthieu; Paquet, Serge; Maccario, Sophie; Smedbol, Élise; Gomes, Marcelo Pedrosa; Lepage, Laurent; Juneau, Philippe; Labrecque, Michel

2017-11-15

Glyphosate is the most widely used herbicide worldwide and is now frequently detected in surface waters of agricultural regions, notably in Quebec (Canada). Numerous legislations require vegetated riparian buffer strips (RBS) along agricultural streams. Quebec policy requires 3-meter-wide RBS. The present study evaluates the efficiency of narrow herbaceous and low- or high-density (33,333 and 55,556stumps/ha) willow, Salix miyabeana 'SX64', RBS, to minimize leaching of glyphosate and its main degradation product (AMPA) from agricultural fields to streams. Our study compared triplicate treatments of herbaceous and willow-planted RBS located in an organic-rich soil at Boisbriand (BB) and in a mineral soil at Saint-Roch-de-l'Achigan (SR). Runoff water was sampled with surface collectors and interstitial water was collected with 35cm or 70cm tension lysimeters. Potential efficiency of the RBS is reported as the percent reduction between edge-of-field and edge-of-stream concentrations in runoff and interstitial waters. Neither glyphosate nor AMPA in runoff were significantly intercepted by the RBS. After field herbicide spraying, glyphosate measured in SR surface soils (0-20cm) was on average 210μg·kg -1 dw (range from undetected to ≤317μg·kg -1 dw). Glyphosate was found to be persistent and its infiltration towards groundwater may be enhanced by the RBS. Contrary to runoff trends, soil glyphosate was significantly less concentrated on the SR edge-of-stream compared to edge-of-field (27-54% potential efficiency). The potential efficiency of herbaceous, low- and high-density willow RBS were undifferentiated. Copyright © 2017 Elsevier B.V. All rights reserved.

Nitrogen removal and greenhouse gas emissions from constructed wetlands receiving tile drainage water.

PubMed

Groh, Tyler A; Gentry, Lowell E; David, Mark B

2015-05-01

Loss of nitrate from agricultural lands to surface waters is an important issue, especially in areas that are extensively tile drained. To reduce these losses, a wide range of in-field and edge-of-field practices have been proposed, including constructed wetlands. We re-evaluated constructed wetlands established in 1994 that were previously studied for their effectiveness in removing nitrate from tile drainage water. Along with this re-evaluation, we measured the production and flux of greenhouse gases (GHGs) (CO, NO, and CH). The tile inlets and outlets of two wetlands were monitored for flow and N during the 2012 and 2013 water years. In addition, seepage rates of water and nitrate under the berm and through the riparian buffer strip were measured. Greenhouse gas emissions from the wetlands were measured using floating chambers (inundated fluxes) or static chambers (terrestrial fluxes). During this 2-yr study, the wetlands removed 56% of the total inlet nitrate load, likely through denitrification in the wetland. Some additional removal of nitrate occurred in seepage water by the riparian buffer strip along each berm (6.1% of the total inlet load, for a total nitrate removal of 62%). The dominant GHG emitted from the wetlands was CO, which represented 75 and 96% of the total GHG emissions during the two water years. The flux of NO contributed between 3.7 and 13% of the total cumulative GHG flux. Emissions of NO were 3.2 and 1.3% of the total nitrate removed from wetlands A and B, respectively. These wetlands continue to remove nitrate at rates similar to those measured after construction, with relatively little GHG gas loss. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Simulation of targeted pollutant-mitigation-strategies to reduce nitrate and sediment hotspots in agricultural watershed.

PubMed

Teshager, Awoke Dagnew; Gassman, Philip W; Secchi, Silvia; Schoof, Justin T

2017-12-31

About 50% of U.S. water pollution problems are caused by non-point source (NPS) pollution, primarily sediment and nutrients from agricultural areas, despite the widespread implementation of agricultural Best Management Practices (BMPs). However, the effectiveness of implementation strategies and type of BMPs at watershed scale are still not well understood. In this study, the Soil and Water Assessment Tool (SWAT) ecohydrological model was used to assess the effectiveness of pollutant mitigation strategies in the Raccoon River watershed (RRW) in west-central Iowa, USA. We analyzed fourteen management scenarios based on systematic combinations of five strategies: fertilizer/manure management, changing row-crop land to perennial grass, vegetative filter strips, cover crops and shallower tile drainage systems, specifically aimed at reducing nitrate and total suspended sediment yields from hotspot areas in the RRW. Moreover, we assessed implications of climate change on management practices, and the impacts of management practices on water availability, row crop yield, and total agricultural production. Our results indicate that sufficient reduction of nitrate load may require either implementation of multiple management practices (38.5% with current setup) or conversion of extensive areas into perennial grass (up to 49.7%) to meet and maintain the drinking water standard. However, climate change may undermine the effectiveness of management practices, especially late in the 21st century, cutting the reduction by up to 65% for nitrate and more for sediment loads. Further, though our approach is targeted, it resulted in a slight decrease (~5%) in watershed average crop yield and hence an overall reduction in total crop production, mainly due to the conversion of row-crop lands to perennial grass. Such yield reductions could be quite spatially heterogeneously distributed (0 to 40%). Copyright © 2017 Elsevier B.V. All rights reserved.

Down-regulation of FcεRI-mediated CD63 basophil response during short-term VIT determined venom-nonspecific desensitization.

PubMed

Čelesnik Smodiš, Nina; Šilar, Mira; Eržen, Renato; Rijavec, Matija; Košnik, Mitja; Korošec, Peter

2014-01-01

We recently showed a desensitization of FcεRI-mediated basophil response after short-term VIT. Our aim was to evaluate the allergen specificity of this desensitization. In 11 Hymenoptera-venom double positive subjects, basophil threshold sensitivity (CD-sens) to anti-FcεRI, honeybee, and Vespula venom was assessed at the beginning and just before the first maintenance dose (MD) of single ultra-rush VIT. In some patients we also monitored CD-sens to rApi m 1 and/or rVes v 5 or other co-sensitizations (i.e., grass pollen). In additional 7 patients, basophils were stripped and sensitized with house dust mite (HDM) IgEs at the same time points. We demonstrated a marked reduction of CD-sens to anti-FcεRI and VIT-specific venom before the first MD in all 18 subjects included. Furthermore, in 10 out of 11 double positive subjects, a significant and comparable decrease before the first MD was also evident for non-VIT venom; this nonspecific decrease was further supported by the opposite recombinant species-specific major allergen. In one subject with additional grass pollen allergy, a decrease of CD-sens to grass allergen was also demonstrated. Similarly, in 7 cases of patients with passively HDM-sensitized basophils, a significant reduction of CD-sens was also evident to de novo sensitized HDM allergen. Short-term VIT induced basophil desensitization to VIT-specific as well as to VIT-nonspecific venom. As opposed to long-term VIT, which induces venom-specific changes, the effect of short-term VIT seems to be venom-nonspecific.

Down-Regulation of FcεRI-Mediated CD63 Basophil Response during Short-Term VIT Determined Venom-Nonspecific Desensitization

PubMed Central

Čelesnik Smodiš, Nina; Šilar, Mira; Eržen, Renato; Rijavec, Matija; Košnik, Mitja; Korošec, Peter

2014-01-01

Background We recently showed a desensitization of FcεRI-mediated basophil response after short-term VIT. Our aim was to evaluate the allergen specificity of this desensitization. Methods In 11 Hymenoptera-venom double positive subjects, basophil threshold sensitivity (CD-sens) to anti-FcεRI, honeybee, and Vespula venom was assessed at the beginning and just before the first maintenance dose (MD) of single ultra-rush VIT. In some patients we also monitored CD-sens to rApi m 1 and/or rVes v 5 or other co-sensitizations (i.e., grass pollen). In additional 7 patients, basophils were stripped and sensitized with house dust mite (HDM) IgEs at the same time points. Results We demonstrated a marked reduction of CD-sens to anti-FcεRI and VIT-specific venom before the first MD in all 18 subjects included. Furthermore, in 10 out of 11 double positive subjects, a significant and comparable decrease before the first MD was also evident for non-VIT venom; this nonspecific decrease was further supported by the opposite recombinant species-specific major allergen. In one subject with additional grass pollen allergy, a decrease of CD-sens to grass allergen was also demonstrated. Similarly, in 7 cases of patients with passively HDM-sensitized basophils, a significant reduction of CD-sens was also evident to de novo sensitized HDM allergen. Conclusions Short-term VIT induced basophil desensitization to VIT-specific as well as to VIT-nonspecific venom. As opposed to long-term VIT, which induces venom-specific changes, the effect of short-term VIT seems to be venom-nonspecific. PMID:24733549

Square-wave adsorptive stripping voltammetric determination of nanomolar levels of bezafibrate using a glassy carbon electrode modified with multi-walled carbon nanotubes within a dihexadecyl hydrogen phosphate film.

PubMed

Ardila, Jorge Armando; Oliveira, Geiser Gabriel; Medeiros, Roberta Antigo; Fatibello-Filho, Orlando

2014-04-07

A highly sensitive method for bezafibrate determination using a glassy carbon electrode (GCE) modified with multi-walled carbon nanotubes within a dihexadecyl hydrogen phosphate film based on square-wave adsorptive stripping voltammetry (SWAdSV) is proposed. The electrochemical behaviour of bezafibrate has been studied by cyclic voltammetry, showing an irreversible anodic peak at a potential of 1.09 V in 0.1 mol L(-1) phosphate buffer solution (pH 2.0). A study of the scan rate showed that the oxidation of bezafibrate is an adsorptive-controlled process, involving the transfer of two electrons and two protons per molecule. The analytical curve was linear over a bezafibrate concentration range from 50 to 910 nmol L(-1), with a detection limit of 16 nmol L(-1). This analytical method was successfully applied for benzafibrate determination in pharmaceutical formulations, with results showing good agreement with those obtained using a comparative spectrophotometric method, and has the potential for field application.

Effect of the Protein Corona on Antibody-Antigen Binding in Nanoparticle Sandwich Immunoassays.

PubMed

de Puig, Helena; Bosch, Irene; Carré-Camps, Marc; Hamad-Schifferli, Kimberly

2017-01-18

We investigated the effect of the protein corona on the function of nanoparticle (NP) antibody (Ab) conjugates in dipstick sandwich immunoassays. Ab specific for Zika virus nonstructural protein 1 (NS1) were conjugated to gold NPs, and another anti-NS1 Ab was immobilized onto the nitrocellulose membrane. Sandwich immunoassay formation was influenced by whether the strip was run in corona forming conditions, i.e., in human serum. Strips run in buffer or pure solutions of bovine serum albumin exhibited false positives, but those run in human serum did not. Serum pretreatment of the nitrocellulose also eliminated false positives. Corona formation around the NP-Ab in serum was faster than the immunoassay time scale. Langmuir binding analysis determined how the immobilized Ab affinity for the NP-Ab/NS1 was impacted by corona formation conditions, quantified as an effective dissociation constant, K D eff . Results show that corona formation mediates the specificity and sensitivity of the antibody-antigen interaction of Zika biomarkers in immunoassays, and plays a critical but beneficial role.

Nitrogen recovery from pig slurry in a two-chambered bioelectrochemical system.

PubMed

Sotres, A; Cerrillo, M; Viñas, M; Bonmatí, A

2015-10-01

Abiotic batch experiments showed that ammonia migration from anode to cathode was favored by an increase in voltage, from 39.9% to 44.6%, using synthetic media. A slight increase in ammonia migration was observed when using pig slurry, reaching a maximum of 49.9%. In a continuously MFC fed with pig slurry with a stripping/absorption unit coupled to the cathode chamber, the highest nitrogen flux (7.2 g N d(-1) m(-2)) was achieved using buffer as catholyte. Nitrogen flux increased to 10.3 g N d(-1) m(-2) when shifting to MEC mode. A clear improvement in nitrogen flux (25.5 g N d(-1) m(-2)) was observed when using NaCl as catholyte. Besides, ammonia stripping was favored, reaching a nitrogen recovery of 94.3% in the absorption column, due to the high pH reached in the cathode. The microbial community analysis revealed an enrichment of certain taxonomic Eubacterial and Archaeal groups when the system shifted from MFC to MEC mode. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electrochemical behavior of chlorogenic acid at a boron-doped diamond electrode and estimation of the antioxidant capacity in the coffee samples based on its oxidation peak.

PubMed

Yardım, Yavuz

2012-04-01

In this study, an electroanalytical methodology for the determination of chlorogenic acid (CGA) was achieved at a boron-doped diamond electrode under adsorptive transfer stripping voltammetric conditions. The values obtained for CGA were used to estimate the antioxidant properties of the coffee sample based on CGA oxidation. By using square-wave stripping mode, the compound yielded a well-defined voltammetric response at +0.49 V with respect to Ag/AgCl in Britton-Robinson buffer at pH 3.0 (after 120 s accumulations at a fixed potential of 0.40 V). At the optimum experimental conditions, linear calibration curve is obtained within the concentration range of 0.25 to 4.0 μg mL⁻¹ with the limit of detection 0.049 μg mL⁻¹ . The developed protocol was successfully applied for the analysis of antioxidant capacity in the coffee products such as Turkish coffee and instant coffee. © 2012 Institute of Food Technologists®

Development of flow-through and dip-stick immunoassays for screening of sulfonamide residues.

PubMed

Zhang, Hongyan; Zhang, Yan; Wang, Shuo

2008-08-20

Two formats of membrane-based competitive enzyme immunoassays (flow-through and dip-stick) have been developed for the screening of sulfonamide residues in pig muscle and milk. Membrane was coated with anti-sulfonamide antibody and a sulfonamide hapten D2-horseradish peroxidase (HRP) conjugant was used as the labeled antigen for competitive assay of sulfonamides. Visual detection limits of the flow-through or dip-stick assay were 1-5 microg L(-1) or 1-10 microg L(-1) in buffer for seven sulfonamides, respectively. Assay validation was performed using samples spiked with single sulfonamide, spiked samples were tested using the developed strip assays and results were compared with those obtained by a validated high-performance liquid chromatograph (HPLC) method. Results showed that the two strip assays were correlated well with HPLC, respectively. With assay times of 5 min (flow-through) and 15 min (dip-stick), these rapid tests could offer simple, rapid and cost-effective on-site screening tools to detect sulfonamides in pig muscle (flow-through or dip-stick) or milk (only dip-stick).

Inter-annual Variability of Evapotranspiration in a Semi-arid Oak-savanna Ecosystem: Measured and Modeled Buffering to Precipitation Changes

NASA Astrophysics Data System (ADS)

Raz-Yaseef, N.; Sonnentag, O.; Kobayashi, H.; Baldocchi, D. D.

2010-12-01

Precipitation (P) is the primary control on vegetation dynamics and productivity, implying that climate induced disturbances in frequency and timing of P are intimately coupled with fluxes of carbon, water and energy. Future climate change is expected to increase extreme rainfall events as well as droughts, suggesting linked vegetation changes to an unknown extent. Semi-arid climates experience large inter-annual variability (IAV) in P, creating natural conditions adequate to study how year-to-year changes in P affect atmosphere-biosphere fluxes. We used a 10-year flux database collected at a semi-arid savanna site in order to: (1) define IAV in P by means of frequency and timing; (2) investigate how changes in P affect the ecohydrology of the forest and its partitioning into the main vapor fluxes, and (3) evaluate model capability to predict IAV of carbon and water fluxes above and below the canopy. This is based on the perception that the capability of process-oriented models to construct the deviation, and not the average, is important in order to correctly predict ecosystem sensitivity to climate change. Our research site was a low density and low LAI (0.8) semi-arid (P=523±180 mm yr-1) savanna site, combined of oaks and grass, and located at Tonzi ranch, California. Measurements of carbon and water fluxes above and below the tree canopy using eddy covariance and supplementary measurements have been made since 2001. Measured fluxes were compared to modeled based on two bio-meteorological process-oriented ecosystem models: BEPS and 3D-CAONAK. Our results show that IAV in P was large, and standard deviation (STD) was 38% of the average. Accordingly, the wet soil period (measured volumetric water content > 8%) varied between 156 days in dry years to 301 days in wet years. IAV of the vapor fluxes were lower than that of P (STD was 17% for the trees and 23% for the floor components), suggesting on ecosystem buffering to changes in P. The timing of grass green up was correlated with the timing of first rains, emphasizing the higher dependence of the floor component on P, as reflected in higher IAV of the grasses compared to the trees. On average, models simulated annual fluxes well (R2>0.93), but IAV of the trees was higher than measured (24%), mostly due to model underestimation during dry years. A threshold at P~500 mm yr-1 was observed (both in measurements and modeled results), above which tree transpiration barely increased. The high IAV of the floor component was not replicated in the models (SDV=5%), although this flux accounted for 55% of total ET. Based on our study we conclude that trees in this semi-arid ecosystem have developed adaptive mechanisms that buffer themselves from the year-to-year variations in precipitation.

Voltammetry of naltrexone in commercial formulation and human body fluids: Quantification and pharmacokinetic studies.

PubMed

Ghoneim, Mohamed M; El-Desoky, Hanaa S; Abdel-Galeil, Mohamed M

2011-06-01

Naltrexone HCl (NAL.HCl) has been reduced at the mercury electrode in Britton-Robinson universal buffer of pH values 2-11 with a mechanism involving the quasi-reversible uptake of the first transferring electron followed by a rate-determining protonation step of its C=O double bond at position C-6. Simple, sensitive, selective and reliable linear-sweep and square-wave adsorptive cathodic stripping voltammetry methods have been described for trace quantitation of NAL.HCl in bulk form, commercial formulation and human body fluids without the necessity for sample pretreatment and/or time-consuming extraction steps prior to the analysis. Limits of quantitation of 6.0×10(-9)M and 8.0×10(-10)M NAL.HCl in bulk form or commercial formulation and of 9.0×10(-9) and 1.0×10(-9)M NAL.HCl in spiked human serum samples were achieved by the described linear and square-wave stripping voltammetry methods, respectively. Furthermore, pharmacokinetic parameters of the drug in human plasma samples of healthy volunteers following the administration of an oral single dose of 50mg NAL.HCl (one Revia(®) tablet) were estimated by means of the described square-wave stripping voltammetry method without interferences from the drug's metabolites and/or endogenous human plasma constituents. The estimated pharmacokinetic parameters were favorably compared with those reported in literature. Copyright © 2011 Elsevier B.V. All rights reserved.

Temporal variation in earthworm abundance and diversity along hedgerow-to-field transects in contrasting agricultural land uses

NASA Astrophysics Data System (ADS)

Prendergast-Miller, Miranda T.; Jones, David; Hodson, Mark E.

2017-04-01

Earthworms are regarded as ecosystem engineers, integral to soil processes such as aggregation, nutrient cycling, water infiltration, plant growth and microbial function. Earthworm surveys were conducted for one year on hedge-to-field transects in arable and pasture fields (Yorkshire, UK). The transects incorporated hedgerow and field margin habitats and extended 60 m into the arable or pasture field. At defined distances, earthworm abundance and biomass were recorded, and earthworms were identified to species and ecological group. Soil density, moisture and temperature were also measured. Additional transects were surveyed on experimental plots with arable-to-ley conversions in the arable fields (wheat crop to grass-clover ley), and tilled plots in the pasture fields (grass-clover ley to wheat crop). The conversion plots were established to determine the benefit of grass-clover leys on soil function; and the tilled pasture plots were established to compare the impact of conventional or minimum tillage practices on earthworm abundance and diversity. A baseline survey was conducted before establishment of the experimental ley and tillage plots. The results showed differences in earthworm abundance, with greater earthworm numbers in the pasture soils compared to arable soils. In both soils, abundance of ecological group was endogeic > epigeic > anecic, and each group was dominated by the same species: Allolobophora chlorotica, Lumbricus castaneus and Apporectodea longa. After one year of treatment, there was some indication of increased earthworm abundance in the arable-to-ley conversion strips. Conversely, tillage in the pasture plots tended to reduce earthworm abundance, and conventional tillage tended to have the greater impact. However, within these major changes, there was also evidence of spatial (distance along transect; field location) and temporal (seasonal) variation on earthworm abundance. Although conversion to ley or tillage did not alter the pattern of ecological grouping, there were changes in species diversity which will also be discussed. This earthworm study is part of a larger project which aims to (1) link soil biodiversity (microbes, soil fauna) with soil function (productivity, water infiltration, drought resilience), and (2) demonstrate the benefits of grass-clover leys and minimum tillage in boosting soil biodiversity, soil function, and hence, sustainable agricultural productivity.

Climate variability has a stabilizing effect on the coexistence of prairie grasses

PubMed Central

Adler, Peter B.; HilleRisLambers, Janneke; Kyriakidis, Phaedon C.; Guan, Qingfeng; Levine, Jonathan M.

2006-01-01

How expected increases in climate variability will affect species diversity depends on the role of such variability in regulating the coexistence of competing species. Despite theory linking temporal environmental fluctuations with the maintenance of diversity, the importance of climate variability for stabilizing coexistence remains unknown because of a lack of appropriate long-term observations. Here, we analyze three decades of demographic data from a Kansas prairie to demonstrate that interannual climate variability promotes the coexistence of three common grass species. Specifically, we show that (i) the dynamics of the three species satisfy all requirements of “storage effect” theory based on recruitment variability with overlapping generations, (ii) climate variables are correlated with interannual variation in species performance, and (iii) temporal variability increases low-density growth rates, buffering these species against competitive exclusion. Given that environmental fluctuations are ubiquitous in natural systems, our results suggest that coexistence based on the storage effect may be underappreciated and could provide an important alternative to recent neutral theories of diversity. Field evidence for positive effects of variability on coexistence also emphasizes the need to consider changes in both climate means and variances when forecasting the effects of global change on species diversity. PMID:16908862

Development of in-situ control diagnostics for application of epitaxial superconductor and buffer layers

DOE Office of Scientific and Technical Information (OSTI.GOV)

B.C. Winkleman; T.V. Giel; Jason Cunningham

1999-07-30

The recent achievements of critical currents in excess of 1 x 10{sup 6} amp/cm{sup 2} at 77 K in YBCO deposited over suitably textured buffer/substrate composites have stimulated interest in the potential fabrication of these coated conductors as wire. Numerous approaches and manufacturing schemes for producing coated conductor wire are currently being developed. Recently, under the US DOE's sponsorship, the University of Tennessee Space Institute performed an extensive evaluation of leading coated conductor processing options. In general, it is their feeling that the science and chemistry that are being developed in the coated conductor wire program now need proper engineeringmore » evaluation to define the most viable options for a commercial fabrication process. All fabrication processes will need process control measurements. This report provides a specific review of the needs and available technologies for process control for many of the coated conductor processing options. This report also addresses generic process monitoring areas in which additional research and development is needed. The concentration is on the two different approaches for obtaining the textured substrates that have been identified as viable candidates. These are the Los Alamos National Laboratory's ion-beam assisted deposition, called IBAD, to obtain a highly textured yttria-stabilized zirconia (YSZ) buffer on nickel alloy strips, and Oak Ridge National Laboratory's rolling assisted, bi-axially textured substrate option called RABiTS{trademark}.« less

Interpretation of Pennsylvania agricultural land use from ERTS-1 data

NASA Technical Reports Server (NTRS)

Mcmurtry, G. J.; Petersen, G. W. (Principal Investigator); Wilson, A. D.

1974-01-01

The author has identified the following significant results. To study the complex agricultural patterns in Pennsylvania, a portion of an ERTS scene was selected for detailed analysis. Various photographic products were made and were found to be only of limited value. This necessitated the digital processing of the ERTS data. Using an unsupervised classification procedure, it was possible to delineate the following categories: (1) forest land with a northern aspect, (2) forest land with a southern aspect, (3) valley trees, (4) wheat, (5) corn, (6) alfalfa, grass, pasture, (7) disturbed land, (8) builtup land, (9) strip mines, and (10) water. These land use categories were delineated at a scale of approximately 1:20,000 on the line printer output. Land use delineations were also made using the General Electric IMAGE 100 interactive analysis system.

Does tree harvesting in riparian areas increase stream sedimentation and turbidity - world-wide experience relative to Australia.

NASA Astrophysics Data System (ADS)

Neary, D.; Smethurst, P.; Petrone, K.

2009-04-01

A typical improved-pasture property in the high-rainfall zone of Australia contains 0.5-2.0 km of waterways per 100 ha. Nationwide, some 25-30 million ha of improved pasture contains about 100,000 km of streams, of which about 75% are currently un-buffered and contributing to soil and water degradation. Farmers and natural resource managers are considering ways to enhance environmental outcomes at farm and catchment scales using stream-side buffers of trees and other perennial vegetation. Benefits of buffers include improved water quality, biodiversity, carbon sequestration and aesthetics. Lack of sound information and funding for establishing and managing buffer zones is hindering wide-scale adoption of this practice. Stream-side areas of farms are generally highly productive (wet and nutrient-rich) and contain a high biodiversity, but they are also high-risk zones for soil and water values and stock safety. Development of options based on a balance between environmental and economic outcomes would potentially promote wider adoption. Australian codes of forest practice currently discourage or prevent harvesting of trees in streamside buffers. These codes were developed exclusively for large-scale native forests and industrial-scale plantations, and were applicable to farm forestry as now required. In countries including USA and Germany trees in stream-side buffers are harvested using Best Management Practices. Trees may grow at a faster rate in riparian zones and provide a commercial return, but the impacts of tree establishment and harvesting on water yield and quality must be evaluated. However, there have been few designed experiments investigating this problem. Australia has recently initiated studies to explore the use of high-value timber species and associated vegetation in riparian zones to improve water quality, particularly suspended sediment. Preliminary information from the Yan Yan Gurt Catchment in Victoria indicate that forested riparian strips can retain 98% of the sediment entrained in runoff from agricultural sections of the catchment. This paper examines the science background from North American and European experiences relative to Australia, with particular emphasis on sediment relationships after tree harvesting using Best Management Practices.

Deprotonation effect of tetrahydrofuran-2-carbonitrile buffer gas dopant in ion mobility spectrometry.

PubMed

Fernandez-Maestre, Roberto; Meza-Morelos, Dairo; Wu, Ching

2016-06-15

When dopants are introduced into the buffer gas of an ion mobility spectrometer, spectra are simplified due to charge competition. We used electrospray ionization to inject tetrahydrofuran-2-carbonitrile (F, 2-furonitrile or 2-furancarbonitrile) as a buffer gas dopant into an ion mobility spectrometer coupled to a quadrupole mass spectrometer. Density functional theory was used for theoretical calculations of dopant-ion interaction energies and proton affinities, using the hybrid functional X3LYP/6-311++(d,p) with the Gaussian 09 program that accounts for the basis set superposition error; analytes structures and theoretical calculations with Gaussian were used to explain the behavior of the analytes upon interaction with F. When F was used as a dopant at concentrations below 1.5 mmol m(-3) in the buffer gas, ions were not observed for α-amino acids due to charge competition with the dopant; this deprotonation capability arises from the production of a dimer with a high formation energy that stabilized the positive charge and created steric hindrance that deterred the equilibrium with analyte ions. F could not completely strip other compounds of their charge because they either showed steric hindrance at the charge site that deterred the approach of the dopant (2,4-lutidine, and DTBP), formed intramolecular bonds that stabilized the positive charge (atenolol), had high proton affinity (2,4-lutidine, DTBP, valinol and atenolol), or were inherently ionic (tetraalkylammonium ions). This selective deprotonation suggests the use of F to simplify spectra of complex mixtures in ion mobility and mass spectrometry in metabolomics, proteomics and other studies that generate complex spectra with thousands of peaks. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Oral manifestations of diabetes mellitus in complete denture wearers.

PubMed

Cristina de Lima, Danielle; Nakata, Gislaine Cristina; Balducci, Ivan; Almeida, Janete Dias

2008-01-01

The oral mucosa has been reported to show a variety of changes in subjects with diabetes mellitus. The purpose of this study was to compare diabetic and nondiabetic subjects wearing complete dentures with regard to salivary flow, salivary buffering capacity, denture retention, and oral mucosal lesions. Sixty subjects, 30 with and 30 without a diagnosis of diabetes, were matched for gender, race, and age. Salivary flow, salivary buffering capacity, glycemia, blood pressure, presence of mucosal lesions, denture retention, use of medications, and behavioral factors (controlled or uncontrolled diet, alcohol consumption, and smoking) reported by the subjects, were evaluated. For the salivary buffering capacity test, 1 mL of saliva was pipetted into a test tube containing 3 mL 0.005 N of hydrochloric acid, and the pH was measured with indicator strips. Group differences were statistically analyzed using the Student t test and the Mann-Whitney test for quantitative variables and the chi-square test for qualitative variables (alpha =.05). Mean (SD) salivary flow was 1.14 (0.87) mL/min in the nondiabetic subjects and 0.95 (0.61) mL/min in the diabetic subjects. Evaluation of self-reported denture retention revealed no significant difference between groups. Denture retention was observed in 66.7% (20/30) of the control group and in 50% (15/30) of the diabetic group. The prevalence of mucosal lesions was 90% (27/30) in the control group and 83.3% (25/30) in the diabetic group. Salivary buffering capacity was 5.80 (0.85) in the control group and 5.26 (0.83) in the diabetic group (P=.017). Within the limitations of this study, no significant differences were observed in salivary flow, denture retention, or oral lesions in diabetic and nondiabetic subjects.

Determination of trace levels of diosmin in a pharmaceutical preparation by adsorptive stripping voltammetry at a glassy carbon electrode.

PubMed

El-Shahawi, M S; Bashammakh, A S; El-Mogy, T

2006-10-01

A systematic study on the electrochemical behavior of diosmin in Britton-Robinson buffer (pH 2.0-10.0) at a glassy carbon electrode (GCE) was made. The oxidation process of the drug was found to be quasi-reversible with an adsorption-controlled step. The adsorption stripping response was evaluated with respect to various experimental conditions, such as the pH of the supporting electrolyte, the accumulation potential and the accumulation time. The observed anodic peak current at +0.73 V vs. Ag/AgCl reference electrode increased linearly over two orders of magnitude from 5.0x10(-8) M to 9.0x10(-6) M. A limit of detection down to 3.5x10(-8) M of diosmin at the GCE was achieved with a mean recovery of 97+/-2.1%. Based on the electrochemical data, an open-circuit accumulation step in a stirred sample solution of BR at pH 3.0 was developed. The proposed method was successfully applied to the determination of the drug in pharmaceutical formulations. The results compared favorably with the data obtained via spectrophotometric and HPLC methods.

Metallo-Graphene Nanocomposite Electrocatalytic Platform for the Determination of Toxic Metal Ions

PubMed Central

Willemse, Chandre M.; Tlhomelang, Khotso; Jahed, Nazeem; Baker, Priscilla G.; Iwuoha, Emmanuel I.

2011-01-01

A Nafion-Graphene (Nafion-G) nanocomposite solution in combination with an in situ plated mercury film electrode was used as a highly sensitive electrochemical platform for the determination of Zn2+, Cd2+, Pb2+ and Cu2+ in 0.1 M acetate buffer (pH 4.6) by square-wave anodic stripping voltammetry (SWASV). Various operational parameters such as deposition potential, deposition time and electrode rotation speed were optimized. The Nafion-G nanocomposite sensing platform exhibited improved sensitivity for metal ion detection, in addition to well defined, reproducible and sharp stripping signals. The linear calibration curves ranged from 1 μg L−1 to 7 μg L−1 for individual analysis. The detection limits (3σ blank/slope) obtained were 0.07 μg L−1 for Pb2+, Zn2+ and Cu2+ and 0.08 μg L−1 for Cd2+ at a deposition time of 120 s. For practical applications recovery studies was done by spiking test samples with known concentrations and comparing the results with inductively coupled plasma mass spectrometry (ICP-MS) analyses. This was followed by real sample analysis. PMID:22163831

Development of a quantum dot-based immunochromatography test strip for rapid screening of oxytetracycline and 4-epi-oxytetracycline in edible animal tissues.

PubMed

Xie, Yong; Zhang, Lei; Yang, Xian; Le, Tao

2017-03-01

A rapid and sensitive immunochromatographic test strip (ICTS) was developed in a competitive format with the quantum dot-conjugated monoclonal antibody specifically to determine the residues of oxytetracycline (OTC) and its metabolite 4-epi-oxytetracycline (4-epi-OTC). Using an ICTS reader, the 50% inhibition concentration (IC 50 ) was found to be 3.41 ± 0.29 ng ml - 1 of OTC in phosphate-buffered saline samples and the detection limit was 0.44 ± 0.05 ng ml - 1 . The visual cut-off level of the ICTS is 25 ng ml - 1 . The recoveries from tissue samples spiked with OTC of 50-600 μg kg - 1 were 74.2-107.2%, with coefficients of variation below 15%. The method was used to analyse incurred tissue samples, and there was good correlation (R 2  = 0.999) between the ICTS and high-performance liquid chromatography. These results indicate that ICTS is suitable for the rapid and quantitative detection of OTC and 4-epi-OTC residues in edible animal tissues.

Readout Electronics for the Forward Vertex Detector at PHENIX

NASA Astrophysics Data System (ADS)

Phillips, Michael

2010-11-01

The PHENIX experiment at RHIC at Brookhaven National Laboratory has been providing high quality physics data for over 10 years. The current PHENIX physics program will be significantly enhanced by addition of the Forward Silicon Vertex upgrade detector (FVTX) in the acceptance of existing muon arm detectors. The proposed tracker is planned to be put into operation in 2012. Each arm of the FVTX detector consist of 4 discs of silicon strip sensors combined with FPHX readout chips, designed at FNAL. The full detector consists of over 1 million active mini-strip channels with instantaneous bandwidth topping 3.4 Tb/s. The FPHX chip utilizes data push architecture with 2 serial output streams at 200 MHz. The readout electronics design consists of Read-Out Cards (ROC) located in the vicinity of the detector and Front End Modules (FEM) located in the Counting House. ROC boards combine the data from several chips, synchronizes data streams and send them to FEM over a Fiber Optics Link. The data are buffered in the FEM and then sent to a standard PHENIX DAQ interface upon Level-1 trigger request. We will present the current status of the readout electronics development and testing, including tests with data from production wedges.

Geologic Map of the Upper Parashant Canyon and Vicinity, Mohave County, Northwestern Arizona

USGS Publications Warehouse

Billingsley, George H.; Harr, Michelle L.; Wellmeyer, Jessica L.

2000-01-01

Introduction The geologic map of the upper Parashant Canyon area covers part of the Colorado Plateau and several large tributary canyons that make up the western part of Arizona's Grand Canyon. The map is part of a cooperative U.S. Geological Survey and National Park Service project to provide geologic information for areas within the newly established Grand Canyon/Parashant Canyon National Monument. Most of the Grand Canyon and parts of the adjacent plateaus have been geologically mapped; this map fills in one of the remaining areas where uniform quality geologic mapping was needed. The geologic information presented may be useful in future related studies as to land use management, range management, and flood control programs for federal and state agencies, and private concerns. The map area is in a remote region of the Arizona Strip, northwestern Arizona about 88 km south of the nearest settlement of St. George, Utah. Elevations range from about 1,097 m (3,600 ft) in Parashant Canyon (south edge of map area) to 2,145 m (7,037 ft) near the east-central edge of the map area. Primary vehicle access is by dirt road locally known as the Mount Trumbull road; unimproved dirt roads and jeep trails traverse various parts of the map area. Travel on the Mount Trumbull road is possible with 2-wheel-drive vehicles except during wet conditions. Extra fuel, two spare tires and extra food and water are highly recommended when traveling in this remote area. The map area includes about 26 sections of land belonging to the State of Arizona, about 40 sections of private land, and a small strip of the Lake Mead National Recreation Area (southeast edge of the map area). The private land is mainly clustered around the abandoned settlement of Mt. Trumbull, locally known as Bundyville, and a few sections are scattered in the upper Whitmore Canyon area just south of Bundyville. Lower elevations within the canyons support a sparse growth of sagebrush, cactus, grass, creosote bush, and a variety of desert shrubs. Sagebrush, grass, cactus, cliffrose bush, pinyon pine trees, juniper trees, and some ponderosa pines thrive at higher elevations. Surface runoff in the north half of the map area drains northward towards the Virgin River in Utah via Hurricane Wash. In the south half of the area, it drains towards the Colorado River in Grand Canyon via Parashant and Whitmore Canyons. Upper Parashant and Whitmore Canyons are part of the physiography of the western Grand Canyon, but are not included within Grand Canyon National Park. The entire map area is now within the newly established Grand Canyon/Parashant Canyon National Monument (as of January, 2000), and is jointly managed by the Lake Mead National Recreational Area, Boulder City, Nevada, and the Bureau of Land Management, Arizona Strip District, St. George, Utah. Surface runoff in the north half of the map area drains northward towards the Virgin River in Utah via Hurricane Wash. In the south half of the area, it drains towards the Colorado River in Grand Canyon via Parashant and Whitmore Canyons. Upper Parashant and Whitmore Canyons are part of the physiography of the western Grand Canyon, but are not included within Grand Canyon National Park. The entire map area is now within the newly established Grand Canyon/Parashant Canyon National Monument (January, 2000), and is jointly managed by the Lake Mead National Recreational Area, Boulder City, Nevada, and the Bureau of Land Management, Arizona Strip District, St. George, Utah.

Separation of dietary omega-3 and omega-6 fatty acids in food by capillary electrophoresis.

PubMed

Soliman, Laiel C; Donkor, Kingsley K; Church, John S; Cinel, Bruno; Prema, Dipesh; Dugan, Michael E R

2013-10-01

A lower dietary omega-6/omega-3 (n-6/n-3) fatty acid ratio (<4) has been shown to be beneficial in preventing a number of chronic illnesses. Interest exists in developing more rapid and sensitive analytical methods for profiling fatty acid levels in foods. An aqueous CE method was developed for the simultaneous determination of 15 n-3 and n-6 relevant fatty acids. The effect of pH and concentration of buffer, type and concentration of organic modifier, and additive on the separation was investigated in order to determine the best conditions for the analysis. Baseline separations of the 15 fatty acids were achieved using 40 mM borate buffer at pH 9.50 containing 50 mM SDS, 10 mM β-cyclodextrin, and 10% acetonitrile. The developed CE method has LODs of <5 mg/L and good linearity (R(2) > 0.980) for all fatty acids studied. The proposed method was successfully applied to the determination of n-3 and n-6 fatty acids in flax seed, Udo® oils and a selection of grass-fed and grain-fed beef muscle samples. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DEVELOPMENT OF IN-SITU CONTROL DIAGNOSTICS FOR APPLICATION OF EPITAXIAL SUPERCONDUCTOR AND BUFFER LAYERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

B.C. Winkleman; T.V. Giel, Jr.; J. Cunningham

1999-06-30

The recent achievements of critical currents in excess of 1x10{sup 6}amp/cm{sup 2} at 77K in YBCO deposited over suitably textured buffer/substrate composites have stimulated interest in the potential fabrication of these coated conductors as wire. Numerous approaches and manufacturing schemes for producing coated conductor wire are currently being developed. Recently, under the U. S. Department of Energy (DOE's) sponsorship, the University of Tennessee Space Institute (UTSI) performed an extensive evaluation of leading coated conductor processing options. In general, it is our feeling that the science and chemistry that are being developed in the coated conductor wire program now need propermore » engineering evaluation to define the most viable options for a commercial fabrication process. All fabrication processes will need process control measurements. This report provides a specific review of the needs and available technologies for process control for many of the coated conductor processing options. This report also addresses generic process monitoring areas in which additional research and development is needed. The concentration is on the two different approaches for obtaining the textured substrates that have been identified as viable candidates. These are the Los Alamos National Laboratory's (LANL) ion-beam assisted deposition, called IBAD, to obtain a highly textured yttria-stabilized zirconia (YSZ) buffer on nickel alloy strips, and Oak Ridge National Laboratory's (ORNL) rolling assisted, bi-axially textured substrate option called RABiTS{trademark}.« less

Water-Soluble 8-Hydroxyquinoline Conjugate of Amino-Glucose As Receptor for La(3+) in HEPES Buffer, on Whatman Cellulose Paper and in Living Cells.

PubMed

Areti, Sivaiah; Bandaru, Sateesh; Teotia, Rohit; Rao, Chebrolu P

2015-12-15

A water-soluble glucopyranosyl conjugate, L, has been synthesized and characterized by different analytical and spectral techniques. The L has been demonstrated to have switch-on fluorescence enhancement of ∼75 fold in the presence of La(3+) among the nine lanthanide ions studied in the HEPES buffer at pH 7.4. A minimum detection limit of 140 nM (16 ± 2 ppb) was shown by L for La(3+) in the buffer at physiological pH. The utility of L has been demonstrated by showing its sensitivity toward La(3+) on Whatman filter paper strips. The reversible and reusable action of L has been demonstrated by monitoring the fluorescence changes as a function of the addition of La(3+) followed by F(-) and HPO4(2-) ions. The complexation of L by La(3+) was shown by absorption spectra wherein isosbestic behavior was observed. The Job's plot suggests a 2:1 complex between L and La(3+), and the same was supported by ESI-MS. The control molecular study revealed the necessity of hydroxy quinoline and the amine group for La(3+) ion binding and the glyco-moiety to bring water solubility and biocompatibility. The structural features of the [2L+La(3+)] complex were established by DFT computational calculations. The chemo-ensemble, [2L+La(3+)], is shown responsible for providing intracellular fluorescence imaging in HepG2 cells.

Methane Production of Different Forages in In vitro Ruminal Fermentation

PubMed Central

Meale, S. J.; Chaves, A. V.; Baah, J.; McAllister, T. A.

2012-01-01

An in vitro rumen batch culture study was completed to compare effects of common grasses, leguminous shrubs and non-leguminous shrubs used for livestock grazing in Australia and Ghana on CH4 production and fermentation characteristics. Grass species included Andropodon gayanus, Brachiaria ruziziensis and Pennisetum purpureum. Leguminous shrub species included Cajanus cajan, Cratylia argentea, Gliricidia sepium, Leucaena leucocephala and Stylosanthes guianensis and non-leguminous shrub species included Annona senegalensis, Moringa oleifera, Securinega virosa and Vitellaria paradoxa. Leaves were harvested, dried at 55°C and ground through a 1 mm screen. Serum bottles containing 500 mg of forage, modified McDougall’s buffer and rumen fluid were incubated under anaerobic conditions at 39°C for 24 h. Samples of each forage type were removed after 0, 2, 6, 12 and 24 h of incubation for determination of cumulative gas production. Methane production, ammonia concentration and proportions of VFA were measured at 24 h. Concentration of aNDF (g/kg DM) ranged from 671 to 713 (grasses), 377 to 590 (leguminous shrubs) and 288 to 517 (non-leguminous shrubs). After 24 h of in vitro incubation, cumulative gas, CH4 production, ammonia concentration, proportion of propionate in VFA and IVDMD differed (p<0.05) within each forage type. B. ruziziensis and G. sepium produced the highest cumulative gas, IVDMD, total VFA, proportion of propionate in VFA and the lowest A:P ratios within their forage types. Consequently, these two species produced moderate CH4 emissions without compromising digestion. Grazing of these two species may be a strategy to reduce CH4 emissions however further assessment in in vivo trials and at different stages of maturity is recommended. PMID:25049482

Use of drinking water treatment residuals as a potential best management practice to reduce phosphorus risk index scores.

PubMed

Dayton, E A; Basta, N T

2005-01-01

The P risk index system has been developed to identify agricultural fields vulnerable to P loss as a step toward protecting surface water. Because of their high Langmuir phosphorus adsorption maxima (P(max)), use of drinking water treatment residuals (WTRs) should be considered as a best management practice (BMP) to lower P risk index scores. This work discusses three WTR application methods that can be used to reduce P risk scores: (i) enhanced buffer strip, (ii) incorporation into a high soil test phosphorus (STP) soil, and (iii) co-blending with manure or biosolids. The relationship between WTR P(max) and reduction in P extractability and runoff P was investigated. In a simulated rainfall experiment, using a buffer strip enhanced with 20 Mg WTR ha(-1), runoff P was reduced by from 66.8 to 86.2% and reductions were related to the WTR P(max). When 25 g kg(-1) WTR was incorporated into a high STP soil of 315 mg kg(-1) determined using Mehlich-3 extraction, 0.01 M calcium chloride-extractable phosphorus (CaCl(2)-P) reductions ranged from 60.9 to 96.0% and were strongly (P < 0.01) related to WTR P(max). At a 100 g kg(-1) WTR addition, Mehlich 3-extractable P reductions ranged from 41.1 to 86.7% and were strongly (P < 0.01) related to WTR P(max). Co-blending WTR at 250 g kg(-1) to manure or biosolids reduced CaCl(2)-P by >75%. The WTR P(max) normalized across WTR application rates (P(max) x WTR application) was significantly related to reductions in CaCl(2)-P or STP. Using WTR as a P risk index modifying factor will promote effective use of WTR as a BMP to reduce P loss from agricultural land.

Behaviour and quantification studies of terbacil and lenacil in environmental samples using cyclic and adsorptive stripping voltammetry at hanging mercury drop electrode.

PubMed

Thriveni, T; Rajesh Kumar, J; Sujatha, D; Sreedhar, N Y

2007-05-01

The cyclic voltammograms of terbacil and lenacil at the hanging mercury drop electrode showed a single well defined four electron irreversible peak in universal buffer of pH 4.0 for both compounds. The peak potentials were shifted to more negative values on the increase of pH of the medium, implying the involvement of protons in the electrode reaction and that the proton transfer reaction precedes the proper electrode process. The four electron single peak may be attributed to the simultaneous reduction of carbonyl groups present in 2 and 4 in pyrimidine ring of terbacil and lenacil to the corresponding hydroxy derivative. Based on the interfacial adsorptive character of the terbacil and lenacil onto the mercury electrode surface, a simple sensitive and low cost differential pulse adsorptive stripping voltammetric procedure was optimized for the analysis of terbacil and lenacil. The optimal operational conditions of the proposed procedure were accumulation potential E (acc) = -0.4 V, accumulation time t (acc) = 80 s, scan rate = 40 mV s(-1), pulse amplitude = 25 mV using a universal buffer pH 4.0 as a supporting electrolyte. The linear concentration range was found to be 1.5 x 10(-5) to 1.2 x 10(-9) mol/l and 1.5 x 10(-5) to 2.5 x 10(-8) mol/l with the lower detection limit of 1.22 x 10(-9) and 2.0 x 10(-8) mol/l. The correlation coefficient and relative standard deviation values are found to be 0.942, 0.996, 1.64% and 1.23%, respectively, for 10 replicants. The procedure was successfully applied for determination of terbacil and lenacil in formulations, mixed formulations, environmental samples such as fruit samples and spiked water samples.

Combining Natural Attenuation Capacity and use of Targeted Technological Mitigation Measures for Reducing Diffuse Nutrient Emissions to Surface Waters: The Danish Way

NASA Astrophysics Data System (ADS)

Kronvang, B.; Højberg, A. L.; Hoffmann, C. C.; Windolf, J.; Blicher-Mathiesen, G.

2015-12-01

Excess nitrogen (N) and phosphorus (P) emissions to surface waters are a high priority environmental problem worldwide for protection of water resources in times of population growth and climate change. As clean water is a scarce resource the struggle for reducing nutrient emissions are an ongoing issue for many countries and regions. Since the mid1980s a wide range of national regulatory general measures have been implemented to reduce land based nitrogen (N) and phosphorus (P) loadings of the Danish aquatic environment. These measures have addressed both point source emissions and emissions from diffuse sources especially from agricultural production. Following nearly 4 decades of combating nutrient pollution our surface waters such as lakes and estuaries are only slowly responding on the 50% reduction in N and 56% reduction in P. Therefore, the implementation of the EU Water Framework Directive in Danish surface waters still call for further reductions of N and P loadings. Therefore, a new era of targeted implemented measures was the outcome of a Commission on Nature and Agriculture established by the Danish Government in 2013. Their White Book points to the need of increased growth and better environment through more targeted and efficient regulation using advanced technological mitigation methods that are implemented intelligently according to the local natural attenuation capacity for nutrients in the landscape. As a follow up a national consensus model for N was established chaining existing leaching, 3D groundwater and surface water models that enable a calculation of the N dynamics and attenuation capacity within a scale of 15 km2. Moreover, several research projects have been conducted to investigate the effect of a suite of targeted mitigation measures such as restored natural wetlands, constructed wetlands, controlled drainage, buffer strips and constructed buffer strips. The results of these studies will be shared in this presentation.

Assessing the impacts of Best Management Practices on nitrate pollution in an agricultural dominated lowland catchment considering environmental protection versus economic development.

PubMed

Haas, Marcelo B; Guse, Björn; Fohrer, Nicola

2017-07-01

Water quality is strongly affected by nitrate inputs in agricultural catchments. Best Management Practices (BMPs) are alternative practices aiming to mitigate the impacts derived from agricultural activities and to improve water quality. Management activities are influenced by different governmental policies like the Water Framework Directive (WFD) and the Renewable Energy Sources Act (EEG). Their distinct goals can be contrasting and hamper an integrated sustainable development. Both need to be addressed in the actual conjuncture in rural areas. Ecohydrological models like the SWAT model are important tools for land cover and land use changes investigation and the assessment of BMPs implementation effects on water quality. Thus, in this study, buffer strip, fertilization reduction and alternative crops were considered as BMPs and were implemented in the SWAT model for the Treene catchment. Their efficiency in terms of nitrate loads reduction related to implementation costs at the catchment scale was investigated. The practices correspond to the catchment conditions and are based on small and mid areal changes. Furthermore, the BMPs were evaluated from the perspective of ecologic and economic policies. The results evidenced different responses of the BMPs. The critical periods in winter were addressed by most of the BMPs. However, some practices like pasture land increase need to be implemented in greater area for better results in comparison to current activities. Furthermore, there is a greater nitrate reduction potential by combining BMPs containing fertilization reduction, buffer strips and soil coverage in winter. The discussion about efficiency showed the complexity of costs stipulation and the relation with arable land and yield losses. Furthermore, as the government policies can be divergent an integrated approach considering all the involved actors is important and seeks a sustainable development. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative effects of vinpocetine and 8-Br-cyclic GMP on the contraction and /sup 45/Ca-fluxes in the rabbit aorta

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu, P.J.; Tetzloff, G.; Ahn, H.S.

1988-07-01

Vinpocetine is a highly specific inhibitor of calmodulin-dependent phosphodiesterase (CaM-PDE) with an IC50 of 19 microM and produces a significant accumulation of cyclic GMP but not cyclic AMP in rabbit aorta. In isolated rabbit aortic strips, vinpocetine (0.01 and 0.1 mM) inhibited the contraction and /sup 45/Ca uptake due to both phenylephrine (1 microM) and KCl (40 mM), whereas 8-Br-cyclic GMP (0.1-1mM) selectively impaired phenylephrine-induced responses. Furthermore, the KCl-stimulated /sup 45/Ca efflux in normal Ca2+ buffer, which reflects elevated cytosolic Ca2+, was greatly diminished by vinpocetine but not by 8-Br-cyclic GMP. However, phenylephrine-induced /sup 45/Ca efflux and contraction in Ca2+-freemore » buffer, which reflect Ca2+ release from intracellular sites, were similarly inhibited by both vinpocetine and 8-Br-cyclic GMP. The results suggest that vinpocetine may effect vasodilatation through blockade of the slow channel and selective inhibition of CaM-PDE in the vascular smooth muscle.« less

The role of Ag buffer layer in Fe islands growth on Ge (111) surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Tsu-Yi, E-mail: phtifu@phy.ntnu.edu.tw; Wu, Jia-Yuan; Jhou, Ming-Kuan

2015-05-07

Sub-monolayer iron atoms were deposited at room temperature on Ge (111)-c(2 × 8) substrates with and without Ag buffer layers. The behavior of Fe islands growth was investigated by using scanning tunneling microscope (STM) after different annealing temperatures. STM images show that iron atoms will cause defects and holes on substrates at room temperature. As the annealing temperature rises, iron atoms pull out germanium to form various kinds of alloyed islands. However, the silver layer can protect the Ag/Ge(111)-(√3×√3) reconstruction from forming defects. The phase diagram shows that ring, dot, and triangular defects were only found on Ge (111)-c(2 × 8) substrates. The kindsmore » of islands found in Fe/Ge system are similar to Fe/Ag/Ge system. It indicates that Ge atoms were pulled out to form islands at high annealing temperatures whether there was a Ag layer or not. But a few differences in big pyramidal or strip islands show that the silver layer affects the development of islands by changing the surface symmetry and diffusion coefficient. The structure characters of various islands are also discussed.« less

Tensile stress-strain behavior of hybrid composite laminates

NASA Technical Reports Server (NTRS)

Kennedy, J. M.

1983-01-01

A study was made of the stress-strain response of several hybrid laminates, and the damage was correlated with nonlinear stress-strain response and ultimate strength. The fibers used in the laminates were graphite, S-glass, and Kevlar. Some laminates with graphite fibers had perforated Mylar film between plies, which lowered the interlaminar bond strength. The laminate configurations were chosen to be like those of buffer strips in large panels and fracture coupons. Longitudinal and transverse specimens were loaded in tension to failure. Some specimens were radiographed to reveal damage due to edge effects. Stress-strain response is discussed in terms of damage shown by the radiographs. Ultimate strengths are compared with simple failure criteria, one of which account for damage.

Two rapid pigmentation tests for identification of Cryptococcus neoformans.

PubMed Central

Kaufmann, C S; Merz, W G

1982-01-01

Two tests were developed for the rapid identification of Cryptococcus neoformans based on pigment produced by the organism's phenoloxidase activity. Caffeic acid was incorporated into cornmeal agar, a medium used routinely for yeast identification. When tested on this medium, only C. neoformans isolates produced brown pigment. All other yeasts maintained their normal morphology and did not produce the reaction product. A non-medium-based test was developed for same-day identification of C. neoformans isolates. Paper strips saturated with a buffered L-beta-3,4-dihydroxyphenylalanine-ferric citrate solution were inoculated with isolates and incubated at 37 degrees C. Pigment production occurred only with C. neoformans isolates, many within 60 to 90 min. All other yeasts remained negative. PMID:7040452

Rough-to-smooth transition of an equilibrium neutral constant stress layer. [atmospheric flow over rough terrain

NASA Technical Reports Server (NTRS)

Logan, E., Jr.; Fichtl, G. H.

1975-01-01

A model is proposed for low-level atmospheric flows over terrains of changing roughness length, such as those found at the windward end of landing strips adjoining rough terrain. The proposed model is used to develop a prediction technique for calculating transition wind and shear-stress profiles in the region following surface roughness discontinuity. The model for the transition region comprises two layers: a logarithmic layer and a buffer layer. The flow is assumed to be steady, two-dimensional, and incompressible, with neutral hydrostatic stability. A diagram is presented for a typical wind profile in the transition region, obtained from the logarithmic and velocity defect profiles using shear stress calculated by relevant equations.

Optimal implementation of green infrastructure practices to reduce adverse impacts of urban areas on hydrology and water quality

NASA Astrophysics Data System (ADS)

Liu, Y.; Collingsworth, P.; Pijanowski, B. C.; Engel, B.

2016-12-01

Nutrient loading from Maumee River watershed is a significant reason for the harmful algal blooms (HABs) problem in Lake Erie. Although studies have explored strategies to reduce nutrient loading from agricultural areas in the Maumee River watershed, the nutrient loading in urban areas also needs to be reduced. Green infrastructure practices are popular approaches for stormwater management and useful for improving hydrology and water quality. In this study, the Long-Term Hydrologic Impact Assessment-Low Impact Development 2.1 (L-THIA-LID 2.1) model was used to determine how different strategies for implementing green infrastructure practices can be optimized to reduce impacts on hydrology and water quality in an urban watershed in the upper Maumee River system. Community inputs, such as the types of green infrastructure practices of greatest interest and environmental concerns for the community, were also considered during the study. Based on community input, the following environmental concerns were considered: runoff volume, Total Suspended Solids (TSS), Total Phosphorous (TP), Total Kjeldahl Nitrogen (TKN), and Nitrate+Nitrite (NOx); green infrastructure practices of interest included rain barrel, cistern, green roof, permeable patio, porous pavement, grassed swale, bioretention system, grass strip, wetland channel, detention basin, retention pond, and wetland basin. Spatial optimization of green infrastructure practice implementation was conducted to maximize environmental benefits while minimizing the cost of implementation. The green infrastructure practice optimization results can be used by the community to solve hydrology and water quality problems.

Effects of Rainfall-Induced Topsoil Structure Changes on Root-Zone Moisture Regime during the Dry Period

NASA Astrophysics Data System (ADS)

Wang, Feng; Chen, Jiazhou; Lin, Lirong

2018-01-01

Rainfall erosion and subsequent intermittent drought are serious barriers for agricultural production in the subtropical red soil region of China. Although it is widely recognized that rainfall-induced soil structure degradation reduced soil water storage and water-holding capacity, the effects of variation of the rainfall-induced topsoil structure on the subsequent soil water regime during the dry period is still rarely considered. The objective of this study was to ascertain the way of rainfall-induced topsoil structure changes on the subsequent soil water regime during the dry period. In a three-year-long experiment, six practices (CK, only crop; SM, straw mulching; PAM, polyacrylamide surface application; B, contour Bahia-grass strip; SPAM, straw mulching and polyacrylamide surface application; and BPAM, contour Bahia-grass strip and polyacrylamide surface application) were conducted at an 8° farmland with planting summer maize resulting in different topsoil structure and root-zone moisture, to establish and reveal the quantitatively relationship between the factors of topsoil structure and soil drought. Rainfall erosion significantly increased the soil crust coverage, and decreased the WSA 0.25, 0-30 mm soil porosity and mean pore size. There was no significant difference during the raining stage of root-zone water storage between CK and other practices. An index of soil drought intensity ( I) and degree ( D) was established using soil water loss rate and soil drought severity. The larger value of I means a higher rate of water loss. The larger value of D means more severe drought. During the dry period, I and D were significantly higher in CK than in other practices. I and D had significantly positively correlation with the crust size and crust coverage, and negatively with WSA 0.25, 15-30 mm soil porosity and mean pore size. Among of soil structure factors, the soil porosity had the largest effect on I and D. The rainfall-induced topsoil structure changes greatly deteriorated the root-zone regime during the dry period mainly due to significant increasing soil water loss but little improving the raining stage of soil water storage. Straw mulching had greater effects than other practices in alleviating rainfall-induced erosion and intermittent drought, and could be a better strategy applied for this region.

Study of Copper and Purine-Copper Complexes on Modified Carbon Electrodes by Cyclic and Elimination Voltammetry

PubMed Central

Trnkova, Libuse; Zerzankova, Lenka; Dycka, Filip; Mikelova, Radka; Jelen, Frantisek

2008-01-01

Using a paraffin impregnated graphite electrode (PIGE) and mercury-modified pyrolytic graphite electrode with basal orientation (Hg-PGEb) copper(II) and Cu(II)-DNA purine base solutions have been studied by cyclic (CV) and linear sweep voltammetry (LSV) in connection with elimination voltammetry with linear scan (EVLS). In chloride and bromide solutions (pH 6), the redox process of Cu(II) proceeded on PIGE with two cathodic and two anodic potentially separated signals. According to the elimination function E4, the first cathodic peak corresponds to the reduction Cu(II) + e- → Cu(I) with the possibility of fast disproportionation 2Cu(I) → Cu(II)+ Cu(0). The E4 of the second cathodic peak signalized an electrode process controlled by a surface reaction. The electrode system of Cu(II) on Hg-PGEb in borate buffer (pH 9.2) was characterized by one cathodic and one anodic peak. Anodic stripping voltammetry (ASV) on PIGE and cathodic stripping voltammetry (CSV) on Hg-PGEb were carried out at potentials where the reduction of copper ions took place and Cu(I)-purine complexes were formed. By using ASV and CSV in combination with EVLS, the sensitivity of Cu(I)-purine complex detection was enhanced relative to either ASV or CSV alone, resulting in higher peak currents of more than one order of magnitude. The statistical treatment of CE data was used to determine the reproducibility of measurements. Our results show that EVLS in connection with the stripping procedure is useful for both qualitative and quantitative microanalysis of purine derivatives and can also reveal details of studied electrode processes. PMID:27879715

Effects of xylitol chewing gum on salivary flow rate, pH, buffering capacity and presence of Streptococcus mutans in saliva.

PubMed

Ribelles Llop, M; Guinot Jimeno, F; Mayné Acién, R; Bellet Dalmau, L J

2010-03-01

The first studies on the use of chewing gum in dentistry were done in the 1970s. The Turku Sugar Studies, carried out between 1970 and 1973, showed the excellent anticaries properties of xylitol chewing gums. Since then, many dentists, particularly in Scandinavian countries, have studied the role of chewing xylitol-sweetened chewing gums as another preventive strategy in the control of dental caries. To compare variations in salivary flow rate, pH, buffering capacity, and levels of Streptococcus mutans in baseline conditions and after chewing paraffin pellets or xylitol chewing gum in children between the ages of 6 and 12 years who eat lunch in a school canteen. The study sample consisted of 90 children divided into 2 study groups, and a control group. The children ate lunch at the canteen of the Escultor Ortells state school in the town of Vila-real (Castellón, Spain). The baseline data recorded in the first phase of the study were compared with the data recorded in the second phase, after 15 minutes of chewing xylitol- sweetened chewing gums or paraffin pellets, depending on the study group. Salivary flow rate was measured by collecting the stimulated saliva in a graduated beaker. Levels of pH were measured using a Cyberscan pH 110 pH meter (Eutech Instruments). CRT buffer strips and the CRT bacteria test (Ivoclar-Vivadent) were used to measure buffering capacity and levels of S. mutans, respectively. The data obtained after sample collection were compared by means of a 1-way analysis of variance using the StatGraphics Plus statistical software package, version 5.0. Statistically significant differences were found (p<.05) when pH, buffering capacity and levels of S. mutans were compared between the 3 groups. Comparison of salivary flow rates revealed no statistically significant differences (p>.05), though salivary flow rates were higher in the groups where gum was chewed. The effect of chewing is essential to the stimulation of salivary flow and the resulting recovery of pH levels and reduction of levels of S. mutans in saliva.

Two simple techniques for the safe Sarcoptes collection and individual mite DNA extraction.

PubMed

Soglia, Dominga; Rambozzi, Luisa; Maione, Sandra; Spalenza, Veronica; Sartore, Stefano; Alasaad, Samer; Sacchi, Paola; Rossi, Luca

2009-10-01

Availability of mites is a recognized limiting factor of biological and genetic investigations of the genus Sarcoptes. Current methods of deoxyribonucleic acid (DNA) extraction from individual mites also need substantial improvement in efficiency and operator friendliness. We have first developed a technique for efficient and safe extraction of living mites from scabietic skin samples (crusts or deep skin scrapings). Its core device is a large plastic syringe connected with a 1.5-ml Eppendorf tube. The source material is introduced in the syringe and the device in a shoe box with the tip half of the tube emerging. Mites migrate towards a heat source during a minimum of 36 h. Then, the tube is detached and the mites utilized without risks for the operators. A second technique allows operator-friendly manipulation of individual mites for DNA extraction. Fixed mites are isolated by adhesion to a small strip of polyvinyl chloride (PVC) adhesive tape operated with tweezers. Then, mite and strip are plunged in the lyses buffer and the sample twice submitted to thermal shock for disruption of the chitinous exoskeleton. Data show that the tape does not interfere with successive DNA extraction with a commercial kit. The corresponding protocol, that we briefly name "PVC adhesive tape + thermal shock + kit DNA extraction," compares favorably with the available ones.

Voltammetric determination of Cd2+ based on the bifunctionality of single-walled carbon nanotubes-Nafion film.

PubMed

Sun, Dong; Xie, Xiafeng; Cai, Yuepiao; Zhang, Huajie; Wu, Kangbing

2007-01-02

In the presence of Nafion, single-walled carbon nanotubes (SWNTs) were easily dispersed into ethanol, resulting in a homogeneous SWNTs/Nafion suspension. After evaporating ethanol, a SWNTs/Nafion film with bifunctionality was constructed onto glassy carbon electrode (GCE) surface. Attributing to the strong cation-exchange ability of Nafion and excellent properties of SWNTs, the SWNTs/Nafion film-coated GCE remarkably enhances the sensitivity of determination of Cd(2+). Based on this, an electrochemical method was developed for the determination of trace levels of Cd(2+) by anodic stripping voltammetry (ASV). In pH 5.0 NaAc-HAc buffer, Cd(2+) was firstly exchanged and adsorbed onto SWNTs/Nafion film surface, and then reduce at -1.10 V. During the positive potential sweep, reduced cadmium was oxidized, and a well-defined stripping peak appeared at -0.84 V, which can be used as analytical signal for Cd(2+). The linear range is found to be from 4.0 x 10(-8) to 4.0 x 10(-6) mol L(-1), and the lowest detectable concentration is estimated to be 4.0 x 10(-9) mol L(-1). Finally, this method was successfully employed to detect Cd(2+) in water samples.

Immunochromatographic strip assay for the rapid and sensitive detection of Salmonella Typhimurium in artificially contaminated tomato samples.

PubMed

Shukla, Shruti; Leem, Hyerim; Lee, Jong-Suk; Kim, Myunghee

2014-06-01

This study was designed to confirm the applicability of a liposome-based immunochromatographic assay for the rapid detection of Salmonella enterica subsp. enterica serovar Typhimurium (Salmonella Typhimurium) in artificially contaminated tomato samples. To determine the detection limit and pre-enrichment incubation time (10, 12, and 18 h pre-enrichment in 1% buffered peptone water), the tests were performed with different cell numbers of Salmonella Typhimurium (3 × 10(0), 3 × 10(1), 3 × 10(2), and 3 × 10(3) CFU·mL(-1)) inoculated into 25 g of crushed tomato samples. The assay was able to detect as few as 30 Salmonella Typhimurium cells per 25 g of tomato samples (1.2 cells·g(-1)) after 12 h pre-enrichment incubation. Moreover, when the developed assay was compared with traditional morphological and biochemical culture-based methods as well as colloidal gold nanoparticle-based commercial test strips, the developed assay yielded positive results for the detection of Salmonella Typhimurium within a shorter period time. These findings confirm that the developed assay may have practical application for the sensitive detection of Salmonella Typhimurium in various food samples, including raw vegetables, with a relatively low detection limit and shorter analysis time.

Testing the suitability of some endemic and exotic species for eco-engineering applications to control slope processes

NASA Astrophysics Data System (ADS)

Cammeraat, L. H.; van Beek, L. P. H.

2009-04-01

Eco-engineering is a growing, but still under rated field at the interface of landscape ecology and civil engineering. Although the principles are already known for a long period, the attention for green remediation techniques is increasing, especially in slope stabilizing projects as well as in soil erosion protection. This study discusses tests carried out on the effectiveness of plants to stabilize steep slopes. Four different treatments were compared: A naturally vegetated terrace slope (Brachyopodum retusem grass dominated), a slope completely stripped from vegetation, a slope planted with Arrundo donax (Spanish cane) and a slope with vetiver grass (Vetiver zizanioides), the last one being an often successfully applied, but exotic tropical species for erosion and slope protection. The tests were carried out in double, on unarmored steep bench terrace slopes (30-60° slope angle) on homogeneous marl in E Spain (Rio Serpis Basin). Vegetation was planted in summer and irrigated during the first summer period. Precipitation and soil temperature were measured and runoff and erosion was measured at the installed ‘Gerlach troughs'. Soil physical properties were determined such as bulk density and shear strength. The uprooting resistance of the vetiver grass was also determined as well as root density, root depth and other root parameters. Above ground plant characteristic such as plant height and base diameter were also measured. Results showed that within one year the bare slope was completely covered again with natural Brachiopodum grass dominated vegetation and that the planted vetiver and Spanish cane vegetation seemed to develop successfully. However, investigations showed that especially the roots of the vetiver grasses were not as well and deeply developed as could be expected from literature, although their surface cover and above ground biomass were good. All tested species worked well with respect to retaining soil material under overland flow conditions including the vetiver grass slopes. In the second spring after the start of the experiment however, a large rainfall event occurred and one of the test slopes planted with vetiver grass, slumped downwards over a slide plane at 30-40 cm depth, whereas the other vetiver slope remained in position. The other test slopes did not show any downward movement or erosion phenomena. The disappointing effectiveness of vetiver might be attributed to 1) hot and dry summer conditions when root growth is reduced or stops, to 2) low winter temperature conditions, which also hampers biomass production or creating frost damage, 3) the relative dense subsoil, which is difficult to penetrate by roots. Although Spanish cane showed good effectiveness, it spreads very fast and uncontrolled to other places, and is then difficult to remove. The conclusion can be made that despite the wide application of vetiver, also in the Mediterranean, it is not suitable for Mediterranean areas with either too dry conditions or that are too cold in winter. Spanish cane is also not suitable for its uncontrolled expansion. The remaining conclusion is that endemic species that are adapted to the local conditions are more favorable for application in eco-engineering applications, given that the species selected have potential for capturing sediment and increasing infiltration under overland flow conditions, or have well developed deep root systems that increase slope stability.

Performance of vegetated swales for improving road runoff quality in a moderate traffic urban area.

PubMed

Leroy, Marie-Charlotte; Portet-Koltalo, Florence; Legras, Marc; Lederf, Franck; Moncond'huy, Vincent; Polaert, Isabelle; Marcotte, Stéphane

2016-10-01

In recent years, due to their economic and ecological advantages, green infrastructures for stormwater management have been widely implemented. The present study focused on vegetated swales and compared two vegetated covers, grassed or planted with macrophytes in order to evaluate their performance in terms of water quality improvement. These swales collected runoff of a moderately busy road (<2500vehday(-1)) in a commercial area. Twelve storm events were analyzed over a two year period with measurement of total suspended solids (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total hydrocarbons (THC), total phosphorous (TP), total Kjeldahl nitrogen (TKN), trace elements and 16 polycyclic aromatic hydrocarbons (PAHs). The grass cover led to poor results due to lower retention of soil particles on which trace elements and PAHs are bounded. The swales planted with macrophytes, with a deeper root system more capable of retaining soil particles, led to reductions of concentrations from 17 to 45% for trace elements such as lead, zinc and copper and 30% for the 16 PAHs in infiltrated waters. In addition, the macrophyte cover showed lower variability of pollutant concentrations in infiltrated waters compared to incoming waters. This buffering capacity is interesting to mitigate the impact of moderate peak pollution on surface water or ground water quality. Copyright © 2016 Elsevier B.V. All rights reserved.

A functional applied material on recognition of metal ion zinc based on the double azine compound.

PubMed

Wei, Taibao; Liang, Guoyan; Chen, Xiaopeng; Qi, Jin; Lin, Qi; Zhang, Youming; Yao, Hong

2017-05-18

A colorimetric and fluorescent probe L has been designed and synthesized, which bearing the double azine moiety and showing a detection limit of 2.725 × 10 -7  M towards Zn 2+ . Based on the basic recognition mechanism of ESIPT and CHEF effect, the L has high selectivity and sensitivity to only Zn 2+ (not Fe 3+ , Hg 2+ , Ag + , Ca 2+ , Co 2+ , Ni 2+ , Cd 2+ , Pb 2+ , Cr 3+ , and Mg 2+ ) within the physiological pH range (pH = 7.0-8.4) and showed a fluorescence switch. Moreover, this detection progress occured in the DMSO/H 2 O ∼ HEPES buffer (80/20, v/v; pH 7.23) solution which can conveniently used on test strip.

Sensitive Voltammetric Determination of Natural Flavonoid Quercetin on a Disposable Graphite Lead

PubMed Central

Vu, Dai Long; Žabčíková, Simona; Ertek, Bensu; Dilgin, Yusuf

2015-01-01

Summary In this paper, a pencil graphite electrode was pretreated using chronoamperometry technique in phosphate buffer solution (pH=7.0) for sensitive determination of quercetin. Oxidation of quercetin was investigated using pretreated pencil graphite electrode and anodic stripping differential pulse voltammetry. Under optimal conditions, the anodic current of quercetin exhibited linear response to its concentration in the range from 0.001 to 1.5 µmol/L with the limit of detection of 0.3·10–3 µmol/L. The proposed method was successfully applied for the determination of quercetin in cranberry and blackcurrant juices with recovery rate from 93.2 to 94.7%. Solid-phase extraction was found to be necessary prior to voltammetric determination of quercetin in fruit juice samples using pretreated pencil graphite electrode. PMID:27904372

Climate Change and Mountain Community Fire Management in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

All, J.; Medler, M.; Cole, R. J.; Arques, S.; Schmitt, C. G.

2014-12-01

In the central Andes of Peru, climate change is altering fire risk through changes in local meteorology and fuel loading. Greater moisture and favorable growing conditions are increasing vegetative productivity, which in turn increases fuel loads. This process is accentuated during El Nino events and potentially results in increased fire occurrence and frequency during relatively dry La Nina events. Park officials are concerned about the ramification of the changes on local ecology and tourist use of the resources. However, using a time-series of two different products from the MODIS Terra and Aqua platforms (Active Fire and Burned Area), TRMM 3B43 precipitation data, and Multivariate ENSO Index data we document fire occurrence and extent from 2000 to 2010 and our analysis indicates that fires are burning exclusively during winter months when there are no natural ignition sources. Globally, fire is used in conjunction with grazing to improve the regeneration and yield of grasses. During our interviews, locals claimed to only set fires in the buffer zone outside of the park, but our analysis indicates that the buffer zone rarely burns and that most fires begin within the park and only occasionally move into the buffer zones. Additionally, we determined that although this is small-scale fire activity every year, overall fire is having a very minor effect on local systems. The park service must develop programs to work with local grazing stakeholders to better limit the impacts of fire, while also address the negative perceptions from tourists in the future. In this instance, fire perception and fire reality are not the same and the challenge for resource managers is how to reconcile these two factors in order to more effectively manage the parklands.

Airborne soil dust and its importance in buffering of atmospheric acidity and critical load assessment, over the semi arid tract of northern India.

NASA Astrophysics Data System (ADS)

Sharma, Disha; Kulshrestha, Umesh

Airborne soil dust and its importance in buffering of atmospheric acidity and critical load assessment, over the semi arid tract of northern India. The Critical Load approach alongwith integrated assessment models has been used in the European nations for policy formations to reduce acidic emissions. This unique approach was applied to assess the of vulnerability of natural systems to the present day atmospheric pollution scenario. The calculated values of critical loads of sulphur ( 225 - 275 eq/ha/yr) and nitrogen (298 - 303 eq/ha/yr), for the soil system in Delhi, were calculated with respect to Anjan grass, Hibiscus and Black siris. The present loads of sulphur (PL(S) = 26.40 eq/ha/yr) and nitrogen (PL(N) = 36.51 eq/ha/yr) were found to be much lower than their critical loads without posing any danger of atmospheric acidic deposition on the soil systems. The study indicated that the system is still protective due to high pH of soil. The nature of buffering capability of calcium derived from soil dust can be considered as a natural tool to combat acidification in the Indian region. The results showed that the pollution status in Delhi is still within the safe limits. However, at the pace at which the city is growing, it is likely that in coming decades, it may exceed these critical values. In order to set deposition limits and avoid adverse effects of acidic deposition this approach can be applied in India too. Such approach is very useful, not only in abating pollution but also in devising means of cost optimal emission abatement strategies.

Beneficial Insect Borders Provide Northern Bobwhite Brood Habitat

PubMed Central

Moorman, Christopher E.; Plush, Charles J.; Orr, David B.; Reberg-Horton, Chris

2013-01-01

Strips of fallow vegetation along cropland borders are an effective strategy for providing brood habitat for declining populations of upland game birds (Order: Galliformes), including northern bobwhite (Colinus virginianus), but fallow borders lack nectar-producing vegetation needed to sustain many beneficial insect populations (e.g., crop pest predators, parasitoids, and pollinator species). Planted borders that contain mixes of prairie flowers and grasses are designed to harbor more diverse arthropod communities, but the relative value of these borders as brood habitat is unknown. We used groups of six human-imprinted northern bobwhite chicks as a bioassay for comparing four different border treatments (planted native grass and prairie flowers, planted prairie flowers only, fallow vegetation, or mowed vegetation) as northern bobwhite brood habitat from June-August 2009 and 2010. All field border treatments were established around nine organic crop fields. Groups of chicks were led through borders for 30-min foraging trials and immediately euthanized, and eaten arthropods in crops and gizzards were measured to calculate a foraging rate for each border treatment. We estimated arthropod prey availability within each border treatment using a modified blower-vac to sample arthropods at the vegetation strata where chicks foraged. Foraging rate did not differ among border treatments in 2009 or 2010. Total arthropod prey densities calculated from blower-vac samples did not differ among border treatments in 2009 or 2010. Our results showed plant communities established to attract beneficial insects should maximize the biodiversity potential of field border establishment by providing habitat for beneficial insects and young upland game birds. PMID:24376759

Stress state during fixation determines susceptibility to fatigue-linked biodegradation in bioprosthetic heart valve materials.

PubMed

Margueratt, Sean D; Lee, J Michael

2002-01-01

Mechanical loading contributes to the structural deterioration of bioprosthetic heart valves. The influence of stress state during fixation may play a substantial role in their failure, linking fatigue damage caused by buckling and tension and the enzymatic degradation of glutaraldehyde-crosslinked collagen. Bovine pericardia were obtained immediately postmortem and 100 mm x 15 mm samples were cut in the base-to-apex direction. Half the samples were subjected to a uniaxial tensile stress of 250 kPa and half remained unloaded during a crosslinking treatment in 0.5% glutaraldehyde. Tissue samples were rinsed and cut into 16 mm x 4 mm test strips. Half of these strips were exposed to cyclic compressive buckling and alternating tension at 30 Hz for 20 million cycles (approx. 7.5 days) using a custom-built multi-sample fatigue system. Fatigue-damaged and non-damaged samples were subsequently incubated at 37 C for 48 hrs in: (i) Type I bacterial collagenase (20 U/ml) buffered in 0.05 M Tris, 10 mM CaCl2 2H2O (pH 7.4) or (ii) 0.05 M Tris buffer (pH 7.4) only. In both cases, the samples were loaded sinusoidally between 40 and 80 g using a previously described microtensile culture system. Tissue removed from the bath was rinsed in 0.1 M EDTA solution and mounted in a servo-hydraulic mechanical testing system (MTS). Ultimate tensile strength (UTS), maximum tissue modulus, and fracture strain were determined. The percent collagen solubilized was assessed by a colourmetric hydroxyproline assay of the enzyme bath and tissue sample. All data were analyzed by analysis of variance (ANOVA). The results confirmed the synergy between fatigue damage and collagenase proteolysis in these materials; however, there were no significant differences in this effect between simple fixation and stress-fixation up to 20 million cycles. There were significant decreases in the mechanical properties and an increase in the amount of collagen solubilized with increased exposure to fatigue cycling.

Herbivore impacts to the moss layer determine tundra ecosystem response to grazing and warming.

PubMed

Gornall, Jemma L; Woodin, Sarah J; Jónsdóttir, Ingibjörg S; Van der Wal, Rene

2009-10-01

Herbivory and climate are key environmental drivers, shaping ecosystems at high latitudes. Here, we focus on how these two drivers act in concert, influencing the high arctic tundra. We aim to investigate mechanisms through which herbivory by geese influences vegetation and soil processes in tundra ecosystems under ambient and warmed conditions. To achieve this, two grazing treatments, clipping plus faecal additions and moss removal, were implemented in conjunction with passive warming. Our key finding was that, in many cases, the tundra ecosystem response was determined by treatment impacts on the moss layer. Moss removal reduced the remaining moss layer depth by 30% and increased peak grass biomass by 27%. These impacts were probably due to observed higher soil temperatures and decomposition rates associated with moss removal. The positive impact of moss removal on grass biomass was even greater with warming, further supporting this conclusion. In contrast, moss removal reduced dwarf shrub biomass possibly resulting from increased exposure to desiccating winds. An intact moss layer buffered the soil to increased air temperature and as a result there was no response of vascular plant productivity to warming over the course of this study. In fact, moss removal impacts on soil temperature were nearly double those of warming, suggesting that the moss layer is a key component in controlling soil conditions. The moss layer also absorbed nutrients from faeces, promoting moss growth. We conclude that both herbivory and warming influence this high arctic ecosystem but that herbivory is the stronger driver of the two. Disturbance to the moss layer resulted in a shift towards a more grass-dominated system with less abundant mosses and shrubs, a trend that was further enhanced by warming. Thus herbivore impacts to the moss layer are key to understanding arctic ecosystem response to grazing and warming.

KSC-07pd0867

NASA Image and Video Library

2007-04-11

KENNEDY SPACE CENTER, FLA. -- What may be a yellow rat snake slithers through the grass on Kennedy Space Center. Yellow rat snakes are found throughout most of Florida and the Keys. They also live in a narrow strip along the Atlantic coast through Georgia, South Carolina and North Carolina. They are often found in warm southern swamps, and are also common in abandoned buildings and barns. Besides rats, yellow rat snakes will eat a wide variety of small mammals, birds, and eggs. They are considered the best tree climbing snake in Florida. The scales on their bellies are squared off, which aids them tremendously with climbing. They are strong constrictors, and kill their prey by suffocation. KSC shares a boundary with the Merritt Island Wildlife Nature Refuge. The refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. In addition, the Refuge supports 19 endangered or threatened wildlife species on Federal or State lists, more than any other single refuge in the U.S. Photo credit: NASA/Dimitri Gerondidakis

Trace vanadium analysis by catalytic adsorptive stripping voltammetry using mercury-coated micro-wire and polystyrene-coated bismuth film electrodes

PubMed Central

Dansby-Sparks, Royce; Chambers, James Q.; Xue, Zi-Ling

2009-01-01

An electrochemical technique has been developed for ultra trace (ngL−1) vanadium (V) measurement. Catalytic adsorptive stripping voltammetry for V analysis was developed at mercury-coated gold micro-wire (MWE, 100 μm) electrodes in the presence of gallic acid (GA) and bromate ion. A potential of −0.275 V (vs Ag/AgCl) was used to accumulate the complex in acetate buffer (pH 5.0) at the electrode surface followed by a differential pulse voltammetric scan. Parameters affecting the electrochemical response, including pH, concentration of GA and bromate, deposition potential and time have been optimized. Linear response was obtained in the 0–1000 ngL−1 range (2 min deposition), with a detection limit of 0.88 ngL−1. The method was validated by comparison of results for an unknown solution of V by atomic absorption measurement. The protocol was evaluated in a real sample by measuring the amount of V in river water samples. Thick bismuth film electrodes with protective polystyrene films have also been made and evaluated as a mercury free alternative. However, ngL−1 level detection was only attainable with extended (10 min) deposition times. The proposed use of MWEs for the detection of V is sensitive enough for future use to test V concentration in biological fluids treated by the advanced oxidation process (AOP). PMID:19446059

Subtropical grass pollen allergens are important for allergic respiratory diseases in subtropical regions

PubMed Central

2012-01-01

Background Grass pollen allergens are a major cause of allergic respiratory disease but traditionally prescribing practice for grass pollen allergen-specific immunotherapy has favoured pollen extracts of temperate grasses. Here we aim to compare allergy to subtropical and temperate grass pollens in patients with allergic rhinitis from a subtropical region of Australia. Methods Sensitization to pollen extracts of the subtropical Bahia grass (Paspalum notatum), Johnson grass (Sorghum halepense) and Bermuda grass (Cynodon dactylon) as well as the temperate Ryegrass (Lolium perenne) were measured by skin prick in 233 subjects from Brisbane. Grass pollen-specific IgE reactivity was tested by ELISA and cross-inhibition ELISA. Results Patients with grass pollen allergy from a subtropical region showed higher skin prick diameters with subtropical Bahia grass and Bermuda grass pollens than with Johnson grass and Ryegrass pollens. IgE reactivity was higher with pollen of Bahia grass than Bermuda grass, Johnson grass and Ryegrass. Patients showed asymmetric cross-inhibition of IgE reactivity with subtropical grass pollens that was not blocked by temperate grass pollen allergens indicating the presence of species-specific IgE binding sites of subtropical grass pollen allergens that are not represented in temperate grass pollens. Conclusions Subtropical grass pollens are more important allergen sources than temperate grass pollens for patients from a subtropical region. Targeting allergen-specific immunotherapy to subtropical grass pollen allergens in patients with allergic rhinitis in subtropical regions could improve treatment efficacy thereby reducing the burden of allergic rhinitis and asthma. PMID:22409901

Concentrations of MUC16 and MUC5AC using three tear collection methods

PubMed Central

Nichols, Jason J.

2017-01-01

Purpose To determine the optimal tear collection method for analysis of ocular surface mucins MUC5AC and MUC16. Methods Fifteen subjects without ocular surface disease were recruited. Subjects presented for tear collection on three separate days for three different tear collection methods with the order of method randomized. Methods used to collect tears from right and left eyes included Schirmer’s strip, basal tear collection, and flush tear collection. All samples from the right eyes were individually analyzed for MUC5AC whereas the left eye samples were individually analyzed for MUC16. For each individual sample, 10 μg of protein were loaded per lane into a 1% (w/v) agarose gel and run in electrophoresis buffer for 2 h. After overnight capillary transfer, membranes were incubated with either MUC5AC antibody CLH2 or MUC16 antibody OC125 for western blot analysis. Blots were developed with enhanced chemiluminescence (ECL) and signals captured with the Odyssey Fc (LI-COR). The relative amounts of MUC5AC and MUC16 were quantified with densitometry using software and compared for statistically significant differences between tear collection methods using the Kruskal–Wallis test in SPSS 22 and GraphPad Prism 7.02. Dunn’s multiple comparisons test was used for pairwise post-hoc comparisons. Results Samples containing less than 10 μg of total protein were not used for analysis which left eight samples (out of 45) unusable. The calculated MUC5AC median signal intensities from Schirmer’s strip, basal tears, and flush tears were 2.86 (n = 15, the interquartile range [IQR] = 2.54–3.21), 1.65 (n = 14, IQR = 1.34–3.1), and 1.67 (n = 9, IQR = 1.42–1.72), respectively (H = 9.5, p = 0.009). Post-hoc pairwise comparisons showed a statistically significant difference between Schirmer’s strip and flush tears (p = 0.01). The calculated MUC16 median signal intensities from Schirmer’s strip, basal tears, and flush tears were 1.88 (n = 14, IQR = 1.43–2.61), 5.24 (n = 15, IQR = 4.16–6.21), and 2.45 (n = 7, IQR = 1.85–2.48), respectively (H = 18.1, p = 0.001). Post-hoc pairwise comparison showed statistically significant differences between basal tears and Schirmer’s strip (p = 0.0003) and between basal tears and flush tears (p = 0.006). Conclusions MUC5AC and MUC16 are present in human tear fluid and can be captured using various tear collection methods. Although basal tear collection yielded the highest relative concentration of MUC16, Schirmer’s strip tear collection yielded the highest MUC5AC concentration. Therefore, the tear collection method chosen depends on the mucin of interest. PMID:28761326

How does the connectivity index change through year in an agricultural catchment?

NASA Astrophysics Data System (ADS)

Cantreul, Vincent; Degré, Aurore

2017-04-01

The emerging concept of hydrological connectivity is difficult to quantify. Some indices have been proposed. The most cited is Borselli's one. It gives the advantage to visualize connectivity at watershed scale with very few inputs. But it is not a dynamic index and the resulting map is not time dependent. However, vegetation cover changes through year and possibly affects the connectivity dynamics. The objective of this poster is to show the evolution of the CI during the year looking at a few "strategic" times. Moreover, the study permits to identify a few "key locations" in the watershed, for example permanent disconnections or at the opposite constantly connected fields. The CI was calculated in a 124ha catchment (Hevillers), in the loess belt, in Belgium. Land use is agricultural with mostly cereals, sugar beets and potatoes, little area with wood, road, path or grass strip. Used weighting factor is soil loss ratio. It is between 0 and 1 and translates the protection offered to the soil by the crop. In winter (January), cereals have the most connected fields because of almost bare soils. Cover crops on sugar beets and potatoes fields decrease connectivity, except for one big field not far from the outlet. But rainfalls are generally not so erosive during this period. In spring (March and May), the cereals have a decreasing CI with plants growth covering the soil. On the opposite, sugar beets and potatoes are planted and bare soils in spring involve much higher connectivity index. The effect of grass strip is strong for sugar beet field situated uphill and underlines the importance of such mitigation measures. In summer (July), the whole watershed is much more disconnected and it does not represent the most risky part of the year in terms of erosion. The end of the year is related to harvesting and consequent bare soil in September for potatoes and November for the rest. In conclusion, the IC is an easy tool to estimate connectivity in a watershed. With the evolution during the year using soil loss ratio in the calculation, it permits to visualize dynamically the connectivity pattern and to localize erosive parts of the catchment for the crop rotation. With a global view on several years, it could be helpful to erosion managers to think about best long-term location of mitigation measures in the watershed. Key-words: hydrological connectivity index, soil loss ratio, erosion, dynamic

Distribution, densities, and ecology of Siberian cranes in the Khroma River region of northern Yakutia in northeastern Russia

USGS Publications Warehouse

Bysykatova, Inga P.; Krapu, Gary L.; Germogenov, Nicolai I.; Buhl, Deborah A.; Aborn, David

2014-01-01

The Siberian crane (Grus leucogeranus) is the third rarest crane species in the world with a breeding range now centered on 3 core areas and a buffer zone in the arctic of northern Yakutia in northeastern Russia. During 16 July-2 August 2009, we undertook ground surveys within the Khroma River core breeding area, surrounding buffer zone, and lands lying to the west of the known rbeeding range to estimate densities and determine habitat use and social status of Siberian cranes. A total of 142 Siberian cranes were sighted (including 55 pairs) at 54 locations with 32 cranes (including 13 pairs) sighted outside the currently known breeding range in the lower drainages of the Syalakh and Syuryuktyakh Rivers. After adjusting for a probability of detection of 0.484 (95% CI = 0.281-0.833), Siberian crane densities in the Khroma core area and the buffer zone averaged 0.0921 cranes/km2 and 0.0363 cranes/km2, respectively. A majority of cranes (n = 93 [65%]) occurred in complexes of large basin wetlands, with use centered in those having extensive beds of pendant grass (Arctophila fulva). Of the 142 cranes seen, 110 (77%) were paired, 21 (15%) were singles, and 11 (8%) were in groups of 3-5. The Khroma core supports 1 of 2 large concentrations of breeding Siberian cranes remaining in the wild; therefore, we recommend that consideration be given to designating a nature reserve that would encompass the Khroma core, adjacent buffer zone, and lands to the west (including coastal tundra areas along the lower drainages of the Syalah and Syuryuktyah Rivers). Further research is needed to gain additional insight into Siberian crane distribution and numbers on lands beyond the currently delineated western boundary of the Siberian crane breeding range in the Ust-Yana District of northern Yakutia. Important gaps remain in information needed to effectively guide conservation efforts for the Eastern Population, and recent advances in remote tracking technology offer potential opportunities to help address several key information needs.

Spatial-Temporal Variations of Water Quality and Its Relationship to Land Use and Land Cover in Beijing, China

PubMed Central

Chen, Xiang; Zhou, Weiqi; Pickett, Steward T. A.; Li, Weifeng; Han, Lijian

2016-01-01

Rapid urbanization with intense land use and land cover (LULC) change and explosive population growth has a great impact on water quality. The relationship between LULC characteristics and water quality provides important information for non-point sources (NPS) pollution management. In this study, we first quantified the spatial-temporal patterns of five water quality variables in four watersheds with different levels of urbanization in Beijing, China. We then examined the effects of LULC on water quality across different scales, using Pearson correlation analysis, redundancy analysis, and multiple regressions. The results showed that water quality was improved over the sampled years but with no significant difference (p > 0.05). However, water quality was significantly different among nonurban and both exurban and urban sites (p < 0.05). Forest land was positively correlated with water quality and affected water quality significantly (p < 0.05) within a 200 m buffer zone. Impervious surfaces, water, and crop land were negatively correlated with water quality. Crop land and impervious surfaces, however, affected water quality significantly (p < 0.05) for buffer sizes greater than 800 m. Grass land had different effects on water quality with the scales. The results provide important insights into the relationship between LULC and water quality, and thus for controlling NPS pollution in urban areas. PMID:27128934

EnviroAtlas -- Fresno, California -- One Meter Resolution Urban Land Cover Data (2010)

EPA Pesticide Factsheets

The Fresno, CA EnviroAtlas One-Meter-scale Urban Land Cover Data were generated via supervised classification of combined aerial photography and LiDAR data. The air photos were United States Department of Agriculture (USDA) National Agricultural Imagery Program (NAIP) four band (red, green, blue, and near infrared) aerial photography at 1-m spatial resolution. Aerial photography ('imagery') was collected on multiple dates in summer 2010. Seven land cover classes were mapped: Water, impervious surfaces (Impervious), soil and barren (Soil), trees and forest (Tree), and grass and herbaceous non-woody vegetation (Grass), agriculture (Ag), and Orchards. An accuracy assessment of 500 completely random and 103 stratified random points yielded an overall User's fuzzy accuracy of 81.1 percent (see below). The area mapped is defined by the US Census Bureau's 2010 Urban Statistical Area for Fresno, CA plus a 1-km buffer. Where imagery was available, additional areas outside the 1-km boundary were also mapped but not included in the accuracy assessment. We expect the accuracy of the areas outside of the 1-km boundary to be consistent with those within. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The da

EnviroAtlas -- Fresno, California -- One Meter Resolution Urban Land Cover Data (2010) Web Service

EPA Pesticide Factsheets

This EnviroAtlas web service supports research and online mapping activities related to EnviroAtlas (https://www.epa.gov/enviroatlas). The Fresno, CA EnviroAtlas One-Meter-scale Urban Land Cover Data were generated via supervised classification of combined aerial photography and LiDAR data. The air photos were United States Department of Agriculture (USDA) National Agricultural Imagery Program (NAIP) four band (red, green, blue, and near infrared) aerial photography at 1-m spatial resolution. Aerial photography ('imagery') was collected on multiple dates in summer 2010. Seven land cover classes were mapped: Water, impervious surfaces (Impervious), soil and barren (Soil), trees and forest (Tree), and grass and herbaceous non-woody vegetation (Grass), agriculture (Ag), and Orchards. An accuracy assessment of 500 completely random and 103 stratified random points yielded an overall User's fuzzy accuracy of 81.1 percent (see below). The area mapped is defined by the US Census Bureau's 2010 Urban Statistical Area for Fresno, CA plus a 1-km buffer. Where imagery was available, additional areas outside the 1-km boundary were also mapped but not included in the accuracy assessment. We expect the accuracy of the areas outside of the 1-km boundary to be consistent with those within. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with

Nutritive Value Response of Native Warm-Season Forage Grasses to Harvest Intervals and Durations in Mixed Stands

PubMed Central

Temu, Vitalis W.; Rude, Brian J.; Baldwin, Brian S.

2014-01-01

Interest in management of native warm-season grasses for multiple uses is growing in southeastern USA. Forage quality response of early-succession mixed stands of big bluestem (BB, Andropogon gerardii), indiangrass (IG, Sorghastrum nutans), and little bluestem (SG, Schizachyrium scoparium) to harvest intervals (30-, 40-, 60-, 90 or 120-d) and durations (one or two years) were assessed in crop-field buffers. Over three years, phased harvestings were initiated in May, on sets of randomized plots, ≥90 cm apart, in five replications (blocks) to produce one-, two-, and three-year-old stands, by the third year. Whole-plot regrowths were machine-harvested after collecting species (IG and LB) sample tillers for leafiness estimates. Species-specific leaf area (SLA) and leaf-to-stem ratio (LSR) were greater for early-season harvests and shorter intervals. In a similar pattern, whole-plot crude protein concentrations were greatest for the 30-d (74 g·kg−1 DM) and the least (40 g·kg−1 DM) for the 120-d interval. Corresponding neutral detergent fiber (NDF) values were the lowest (620 g·kg−1 DM) and highest (710 g·kg−1 DM), respectively. In vitro dry matter and NDF digestibility were greater for early-season harvests at shorter intervals (63 and 720 g·kg−1 DM). With strategic harvesting, similar stands may produce quality hay for beef cattle weight gain. PMID:27135504

EnviroAtlas - Austin, TX - Riparian Buffer Land Cover by Block Group

EPA Pesticide Factsheets

This EnviroAtlas dataset describes the percentage of forested, vegetated, and impervious land within 15- and 50-meters of hydrologically connected streams, rivers, and other water bodies within the EnviroAtlas community area. Forest is defined as Trees & Forest. Vegetated cover is defined as Trees & Forest and Grass & Herbaceous. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

Ultrasensitive and low-volume point-of-care diagnostics on flexible strips - a study with cardiac troponin biomarkers

NASA Astrophysics Data System (ADS)

Shanmugam, Nandhinee Radha; Muthukumar, Sriram; Prasad, Shalini

2016-09-01

We demonstrate a flexible, mechanically stable, and disposable electrochemical sensor platform for monitoring cardiac troponins through the detection and quantification of cardiac Troponin-T (cTnT). We designed and fabricated nanostructured zinc oxide (ZnO) sensing electrodes on flexible porous polyimide substrates. We demonstrate ultrasensitive detection is capable at very low sample volumes due to the confinement phenomenon of target species within the ZnO nanostructures leading to enhancement of biomolecular binding on the sensor electrode surface. The performance of the ZnO nanostructured sensor electrode was evaluated against gold and nanotextured ZnO electrodes. The electrochemical sensor functions on affinity based immunoassay principles whereby monoclonal antibodies for cTnT were immobilized on the sensor electrodes using thiol based chemistry. Detection of cTnT in phosphate buffered saline (PBS) and human serum (HS) buffers was achieved at low sample volumes of 20 μL using non-faradaic electrochemical impedance spectroscopy (EIS). Limit of detection (LOD) of 1E-4 ng/mL (i.e. 1 pg/mL) at 7% CV (coefficient of variation) for cTnT in HS was demonstrated on nanostructured ZnO electrodes. The mechanical integrity of the flexible biosensor platform was demonstrated with cyclic bending tests. The sensor performed within 12% CV after 100 bending cycles demonstrating the robustness of the nanostructured ZnO electrochemical sensor platform.

Grass pollen allergens globally: the contribution of subtropical grasses to burden of allergic respiratory diseases.

PubMed

Davies, J M

2014-06-01

Grass pollens of the temperate (Pooideae) subfamily and subtropical subfamilies of grasses are major aeroallergen sources worldwide. The subtropical Chloridoideae (e.g. Cynodon dactylon; Bermuda grass) and Panicoideae (e.g. Paspalum notatum; Bahia grass) species are abundant in parts of Africa, India, Asia, Australia and the Americas, where a large and increasing proportion of the world's population abide. These grasses are phylogenetically and ecologically distinct from temperate grasses. With the advent of global warming, it is conceivable that the geographic distribution of subtropical grasses and the contribution of their pollen to the burden of allergic rhinitis and asthma will increase. This review aims to provide a comprehensive synthesis of the current global knowledge of (i) regional variation in allergic sensitivity to subtropical grass pollens, (ii) molecular allergenic components of subtropical grass pollens and (iii) allergic responses to subtropical grass pollen allergens in relevant populations. Patients from subtropical regions of the world show higher allergic sensitivity to grass pollens of Chloridoideae and Panicoideae grasses, than to temperate grass pollens. The group 1 allergens are amongst the allergen components of subtropical grass pollens, but the group 5 allergens, by which temperate grass pollen extracts are standardized for allergen content, appear to be absent from both subfamilies of subtropical grasses. Whilst there are shared allergenic components and antigenic determinants, there are additional clinically relevant subfamily-specific differences, at T- and B-cell levels, between pollen allergens of subtropical and temperate grasses. Differential immune recognition of subtropical grass pollens is likely to impact upon the efficacy of allergen immunotherapy of patients who are primarily sensitized to subtropical grass pollens. The literature reviewed herein highlights the clinical need to standardize allergen preparations for both types of subtropical grass pollens to achieve optimal diagnosis and treatment of patients with allergic respiratory disease in subtropical regions of the world. © 2014 John Wiley & Sons Ltd.

50 CFR 21.49 - Control order for resident Canada geese at airports and military airfields.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., (F) Registered animal drugs, pesticides, and repellants, (G) Cervical dislocation, and (H) CO2..., fleshy owl's clover, Colusa grass, hairy Orcutt grass, Solano grass, Greene's tuctoria, Sacramento Valley Orcutt grass, San Joaquin Valley Orcutt grass, slender Orcutt grass, California Orcutt grass, spreading...

50 CFR 21.49 - Control order for resident Canada geese at airports and military airfields.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., (F) Registered animal drugs, pesticides, and repellants, (G) Cervical dislocation, and (H) CO2..., fleshy owl's clover, Colusa grass, hairy Orcutt grass, Solano grass, Greene's tuctoria, Sacramento Valley Orcutt grass, San Joaquin Valley Orcutt grass, slender Orcutt grass, California Orcutt grass, spreading...

50 CFR 21.50 - Depredation order for resident Canada geese nests and eggs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... goldfields, Hoover's spurge, fleshy owl's clover, Colusa grass, hairy Orcutt grass, Solano grass, Greene's tuctoria, Sacramento Valley Orcutt grass, San Joaquin Valley Orcutt grass, slender Orcutt grass, California Orcutt grass, spreading navarretia, and San Jacinto Valley crownscale. (e) Can the depredation order be...

50 CFR 21.50 - Depredation order for resident Canada geese nests and eggs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... goldfields, Hoover's spurge, fleshy owl's clover, Colusa grass, hairy Orcutt grass, Solano grass, Greene's tuctoria, Sacramento Valley Orcutt grass, San Joaquin Valley Orcutt grass, slender Orcutt grass, California Orcutt grass, spreading navarretia, and San Jacinto Valley crownscale. (e) Can the depredation order be...

Small mammal use of native warm-season and non-native cool-season grass forage fields

USGS Publications Warehouse

Ryan L Klimstra,; Christopher E Moorman,; Converse, Sarah J.; Royle, J. Andrew; Craig A Harper,

2015-01-01

Recent emphasis has been put on establishing native warm-season grasses for forage production because it is thought native warm-season grasses provide higher quality wildlife habitat than do non-native cool-season grasses. However, it is not clear whether native warm-season grass fields provide better resources for small mammals than currently are available in non-native cool-season grass forage production fields. We developed a hierarchical spatially explicit capture-recapture model to compare abundance of hispid cotton rats (Sigmodon hispidus), white-footed mice (Peromyscus leucopus), and house mice (Mus musculus) among 4 hayed non-native cool-season grass fields, 4 hayed native warm-season grass fields, and 4 native warm-season grass-forb ("wildlife") fields managed for wildlife during 2 summer trapping periods in 2009 and 2010 of the western piedmont of North Carolina, USA. Cotton rat abundance estimates were greater in wildlife fields than in native warm-season grass and non-native cool-season grass fields and greater in native warm-season grass fields than in non-native cool-season grass fields. Abundances of white-footed mouse and house mouse populations were lower in wildlife fields than in native warm-season grass and non-native cool-season grass fields, but the abundances were not different between the native warm-season grass and non-native cool-season grass fields. Lack of cover following haying in non-native cool-season grass and native warm-season grass fields likely was the key factor limiting small mammal abundance, especially cotton rats, in forage fields. Retention of vegetation structure in managed forage production systems, either by alternately resting cool-season and warm-season grass forage fields or by leaving unharvested field borders, should provide refugia for small mammals during haying events.

Pushbroom Hyperspectral Imaging from AN Unmanned Aircraft System (uas) - Geometric Processingworkflow and Accuracy Assessment

NASA Astrophysics Data System (ADS)

Turner, D.; Lucieer, A.; McCabe, M.; Parkes, S.; Clarke, I.

2017-08-01

In this study, we assess two push broom hyperspectral sensors as carried by small (10-15 kg) multi-rotor Unmanned Aircraft Systems (UAS). We used a Headwall Photonics micro-Hyperspec push broom sensor with 324 spectral bands (4-5 nm FWHM) and a Headwall Photonics nano-Hyperspec sensor with 270 spectral bands (6 nm FWHM) both in the VNIR spectral range (400-1000 nm). A gimbal was used to stabilise the sensors in relation to the aircraft flight dynamics, and for the micro-Hyperspec a tightly coupled dual frequency Global Navigation Satellite System (GNSS) receiver, an Inertial Measurement Unit (IMU), and Machine Vision Camera (MVC) were used for attitude and position determination. For the nano-Hyperspec, a navigation grade GNSS system and IMU provided position and attitude data. This study presents the geometric results of one flight over a grass oval on which a dense Ground Control Point (GCP) network was deployed. The aim being to ascertain the geometric accuracy achievable with the system. Using the PARGE software package (ReSe - Remote Sensing Applications) we ortho-rectify the push broom hyperspectral image strips and then quantify the accuracy of the ortho-rectification by using the GCPs as check points. The orientation (roll, pitch, and yaw) of the sensor is measured by the IMU. Alternatively imagery from a MVC running at 15 Hz, with accurate camera position data can be processed with Structure from Motion (SfM) software to obtain an estimated camera orientation. In this study, we look at which of these data sources will yield a flight strip with the highest geometric accuracy.

Development of a novel and cost-effective redox sensor for voltammetric determination of pantoprazole sodium during pharmacokinetic studies

PubMed Central

Khashaba, Pakinaz Y.; Ali, Hassan Refat H.

2017-01-01

A pencil graphite electrode modified with poly (bromocresol green (BCG)) was prepared by electro-polymerization process for the determination of pantoprazole sodium. The surface morphology and structure of poly (BCG) film were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The determination of pantoprazole sodium in Britton–Robinson buffer (pH 7.0) was carried out by square wave adsorptive stripping voltammetric technique. Under optimum conditions, the linear response of the peak with concentration of the cited drug was in the range of 6.6–360 × 10−8 M with limit of detection of 2.2 × 10−8 M. Moreover, the poly (BCG)-modified electrode has been successfully applied to determine pantoprazole sodium in tablets, vials and during pharmacokinetic studies. PMID:28878983

Evaluating the potential for watershed restoration to reduce nutrient loading to Upper Klamath Lake, Oregon

USGS Publications Warehouse

McCormick, Paul V.; Campbell, Sharon G.

2007-01-01

A literature review of best management practices to reduce nutrient loading was performed to provide information for resource managers in the Klamath Basin, Oregon. Although BMPs have already been implemented in the watershed, some sense of their effectiveness in reducing phosphorus loading and their cost for installation and maintenance is still lacking. This report discusses both causes of nutrient loading and a wide-variety of BMPs used to treat or reduce causal factors. We specifically focused on cattle grazing as the principal land-use and causal factor for nutrient loading in the Klamath Basin above Upper Klamath Lake, Oregon. Several BMP types, including stream corridor fencing, riparian buffer strips and constructed wetlands, seem to have potential for reducing phosphorus loading that may result from cattle grazing. However, no single BMP is likely to be the most effective in all locations or situations.

Vibrational spectra of individual millimeter-size membrane patches using miniature infrared waveguides.

PubMed Central

Plunkett, S E; Jonas, R E; Braiman, M S

1997-01-01

We have used miniature planar IR waveguides, consisting of Ge strips 30-50 microm thick and 2 mm wide, as evanescent-wave sensors to detect the mid-(IR) evanescent-wave absorbance spectra of small areas of biomolecular monolayers and multilayers. Examples include picomolar quantities of an integral transmembrane protein (bacteriorhodopsin) and lipid (dimyristoyl phosphatidylcholine). IR bands due to the protein and lipid components of the plasma membrane of individual 1.5-mm-diameter devitellinized Xenopus laevis oocytes, submerged in buffer and sticking to the waveguide surface, were also detected. A significant improvement in sensitivity was observed, as compared to previous sizes and geometries of evanescent-wave sensors (e.g., commercially available internal reflection elements or tapered optical fibers). These measurements suggest the feasibility of using such miniature supported planar IR waveguides to observe structural changes in transmembrane proteins functioning in vivo in single cells. PMID:9336219

Biomonitors of stream quality on agricultural areas: fish versus invertebrates

USGS Publications Warehouse

Berkman, Hilary E.; Rabeni, Charles F.; Boyle, Terence P.

1986-01-01

Although the utility of using either fish or benthic invertebrates as biomonitors of stream quality has been clearly shown, there is little comparative information on the usefulness of the groups in any particular situation. We compared fish to invertebrate assemblages in their ability to reflect habitat quality of sediment-impacted streams in agricultural regions of northeast Missouri, USA. Habitat quality was measured by a combination of substrate composition, riparian type, buffer strip width, and land use. Invertebrates were more sensitive to habitat differences when structural measurements, species diversity and ordination, were used. Incorporating ecological measurements, by using the Index of Biological Integrity, increased the information obtained from the fish assemblage. The differential response of the two groups was attributed to the more direct impact of sediments on invertebrate life requisites; the impact of sedimentation on fish is considered more indirect and complex, affecting feeding and reproductive mechanisms.

Microbial detection method based on sensing molecular hydrogen

NASA Technical Reports Server (NTRS)

Wilkins, J. R.; Stoner, G. E.; Boykin, E. H.

1974-01-01

A simple method for detecting bacteria, based on the time of hydrogen evolution, was developed and tested against various members of the Enterobacteriaceae group. The test system consisted of (1) two electrodes, platinum and a reference electrode, (2) a buffer amplifier, and (3) a strip-chart recorder. Hydrogen evolution was measured by an increase in voltage in the negative (cathodic) direction. A linear relationship was established between inoculum size and the time hydrogen was detected (lag period). Lag times ranged from 1 h for 1 million cells/ml to 7 h for 1 cell/ml. For each 10-fold decrease in inoculum, length of the lag period increased 60 to 70 min. Based on the linear relationship between inoculum and lag period, these results indicate the potential application of the hydrogen-sensing method for rapidly detecting coliforms and other gas-producing microorganisms in a variety of clinical, food, and other samples.

Post-breakdown secondary discharges at the electrode/dielectric interface of a cylindrical barrier discharge

NASA Astrophysics Data System (ADS)

Carman, Robert; Ward, Barry; Kane, Deborah

2011-10-01

The electrical breakdown characteristics of a double-walled cylindrical dielectric barrier discharge (DBD) lamp with a neon buffer gas under pulsed voltage excitation have been investigated. Following the formation of plasma in the main discharge gap, we have observed secondary breakdown phenomena at the inner and outer mesh electrode/dielectric interfaces under specific operating conditions. Plasma formation at these interfaces is investigated by monitoring the Ozone production rate in controlled flows of ultra high purity oxygen together with the overall electrical voltage-charge characteristics of the lamp. The results show that this secondary breakdown only occurs after the main discharge plasma has been established, and that significant electrical power may be dissipated in generating these spurious secondary plasmas. The results are important with regards to optimising the design and identifying efficient operating regimes of DBD based devices that employ mesh-type or wire/strip electrodes.

The TRUSPEAK Concept: Combining CMPO and HDEHP for Separating Trivalent Lanthanides from the Transuranic Elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lumetta, Gregg J.; Gelis, Artem V.; Braley, Jenifer C.

2013-04-08

Combining octyl(phenyl)-N,N-diisobutyl-carbamoylmethyl-phosphine oxide (CMPO) and bis-(2-ethylhexyl) phosphoric acid (HDEHP) into a single process solvent for separating transuranic elements from liquid high-level waste is explored. Co-extraction of americium and the lanthanide elements from nitric acid solution is possible with a solvent mixture consisting of 0.1-M CMPO plus 1-M HDEHP in n-dodecane. Switching the aqueous-phase chemistry to a citrate-buffered solution of diethylene triamine pentaacetic acid (DTPA) allows for selective stripping of americium, separating it from the lanthanide elements. Potential strategies for managing molybdenum and zirconium (both of which co-extract with americium and the lanthanides) have been developed. The work presented here demonstratesmore » the feasibility of combining CMPO and HDEHP into a single extraction solvent for recovering americium from high-level waste and its separation from the lanthanides.« less

Combining CMPO and HEH[EHP] for Separating Trivalent Lanthanides from the Transuranic Elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braley, Jenifer C.; Lumetta, Gregg J.; Carter, Jennifer C.

2013-09-05

Combining octyl(phenyl)-N,N-diisobutyl-carbamoylmethylphosphine oxide (CMPO) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) into a single process solvent for separating transuranic elements from liquid high-level waste is explored. The lanthanides and americium can be co-extracted from HNO3 into 0.2 mol/L CMPO + 1.0 mol/L HEH[EHP] in n-dodecane. The extraction is relatively insensitive to the HNO3 concentration within 0.1 to 5 mol/L HNO3. Americium can be selectively stripped from the CMPO/HEH[EHP] solvent into a citrate-buffered N-(2-hydroxyethyl)ethylenediaminetriacetic acid solution . Separation factors >14 can be achieved in the range pH 2.5 to 3.7, and the separation factors are relatively insensitive to pH, a major advantagemore » of this solvent formulation.« less

Role of nitric oxide in in vitro contractile activity of the third compartment of the stomach in llamas.

PubMed

Van Hoogmoed, L; Rakestraw, P C; Snyder, J R; Harmon, F A

1998-09-01

To determine the role of nitric oxide and an apamin-sensitive nonadrenergic-noncholinergic inhibitory transmitter in in vitro contractile activity of the third compartment in llamas. Isolated strips of third compartment of the stomach from 5 llamas. Strips were mounted in tissue baths containing oxygenated Kreb's buffer solution and connected to a polygraph chart recorder to measure contractile activity. Atropine, guanethidine, and indomethacin were added to tissue baths to inhibit muscarinic receptors, adrenoreceptors, and prostaglandin synthesis. Responses to electrical field stimulation following addition of the nitric oxide antagonist Nwo-nitro-L-arginine methyl ester (L-NAME) and apamin were evaluated. Electrical field stimulation (EFS) resulted in a reduction in the amplitude and frequency of contractile activity, followed by rebound contraction when EFS was stopped. Addition of L-NAME resulted in a significant reduction in inhibition of contractile activity. Addition of apamin also resulted in a significant reduction in inhibitory contractile activity at most stimulation frequencies. The combination of L-NAME and apamin resulted in a significant reduction in inhibition at all frequencies. Nitric oxide and a transmitter acting via an apamin-sensitive mechanism appear to be involved in inhibition of contractile activity of the third compartment in llamas. Results suggest that nitric oxide plays an important role in mediating contractile activity of the third compartment in llamas. Use of nitric oxide synthase inhibitors may have a role in the therapeutic management of llamas with lesions of the third compartment.

Evaluation of pulsed laser deposited SrNb0.1Co0.9O3-δ thin films as promising cathodes for intermediate-temperature solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Chen, Dengjie; Chen, Chi; Gao, Yang; Zhang, Zhenbao; Shao, Zongping; Ciucci, Francesco

2015-11-01

SrNb0.1Co0.9O3-δ (SNC) thin films prepared on single-crystal yttria-stabilized zirconia (YSZ) electrolytes are evaluated as promising cathodes for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Geometrically well-defined polycrystalline SNC thin films with low surface roughness and high surface oxygen vacancy concentration are successfully fabricated by pulsed laser deposition. The thin films are characterized by basic techniques, e.g., X-ray diffraction for phase structure identification, scanning electron microscopy and atomic force microscopy for microstructures measurement, and X-ray photoelectron spectroscopy for elements quantification. Electrochemical impedance spectroscopy (EIS) is used to investigate oxygen reduction reaction activities of SNC thin films in symmetric electrochemical cells. Current collectors (Ag paste, Ag strip, and Au strip) are found to have negligible impact on polarization resistances. A slight decrease of the electrode polarization resistances is observed after adding a samarium doped ceria (SDC) buffer layer between SNC and YSZ. SNC thin-film electrodes exhibit low electrode polarization resistances, e.g., 0.237 Ω cm2 (SNC/SDC/YSZ/SDC/SNC) and 0.274 Ω cm2 (SNC/YSZ/SNC) at 700 °C and 0.21 atm, demonstrating the promise of SNC materials for IT-SOFCs. An oxygen reduction reaction mechanism of SNC thin films is also derived by analyzing EIS at temperature of 550-700 °C under oxygen partial pressure range of 0.04-1 atm.

A novel bacterial type II l-asparaginase and evaluation of its enzymatic acrylamide reduction in French fries.

PubMed

Sun, Zhibin; Qin, Ran; Li, Ding; Ji, Kai; Wang, Ting; Cui, Zhongli; Huang, Yan

2016-11-01

This study reports the identification of a novel bacterial type II l-asparaginase, abASNase2, from Aquabacterium sp. A7-Y. The enzyme contains 319 amino acids and shared 35% identity with Escherichia coli type II l-asparaginase (EcAII), a commercial enzyme trademarked Elspar ® that is widely used for medical applications. abASNase2 had high specific activity (458.9U/mg) toward l-asparagine, very low activity toward l-glutamine and d-glutamine and no activity toward d-asparagine. The optimal enzymatic activity conditions for abASNase2 were found to be 50mM Tris-HCl buffer (pH 9.0) at 60°C. It was very stable in the pH range of 7.0-11.0 and exhibited up to 80% relative activity after 2h below 40°C. The K m and k cat of abASNase2 were 1.8×10 -3 M and 241.9s -1 , respectively. In addition, abASNase2's ability to remove acrylamide from fried potato strips was evaluated. Compared to untreated potato strips (acrylamide content: 0.823±0.0457mg/kg), 88.2% acrylamide was removed in the abASNase2-treated group (acrylamide content: 0.097±0.0157mg/kg). These results indicate that the novel l-asparaginase abASNase2 is a potential candidate for applications in the food processing industry. Copyright © 2016 Elsevier B.V. All rights reserved.

Simple and green synthesis of piperazine-grafted reduced graphene oxide and its application for the detection of Hg(II)

NASA Astrophysics Data System (ADS)

Zuo, Yinxiu; Xu, Jingkun; Xing, Huakun; Duan, Xuemin; Lu, Limin; Ye, Guo; Jia, Haiyan; Yu, Yongfang

2018-04-01

In this paper, piperazine-grafted reduced graphene oxide (NH-rGO) was synthesized via a simple and green two-step procedure: (i) opening of the resulting epoxides of graphene oxide (GO) with piperazine (NH) through nucleophilic substitution; (ii) reduction of GO with ascorbic acid. Its structure and morphology were characterized by scanning electron microscopy and x-ray photoelectron spectroscopy. The NH-rGO modified glassy carbon electrode was explored as an electrochemical sensor for the determination of Hg(II) using a differential pulse anodic stripping voltammetry technique. Hg(II) can be efficiently accumulated and deposited on the surface of a modified electrode by strong coordination chemical bonds formed between Hg(II) and NH. And then the anodic stripping current can be significantly enhanced by rGO with the merits of large specific surface area and high conductivity, which served as a signal amplifier, finally realizing the highly sensitive determination of Hg(II). The experimental parameters including the pH value of the acetate buffer, deposition potential and deposition time were optimized. Under optimal conditions, the developed sensor exhibited a wide linear range from 0.4-12 000 nM with a low limit of detection of 0.2 nM, which is well below the guideline value in drinking water set by the WHO. Moreover, the practical application of this method was confirmed by an assay of Hg(II) in tap water samples with acceptable results.

Simple and green synthesis of piperazine-grafted reduced graphene oxide and its application for the detection of Hg(II).

PubMed

Zuo, Yinxiu; Xu, Jingkun; Xing, Huakun; Duan, Xuemin; Lu, Limin; Ye, Guo; Jia, Haiyan; Yu, Yongfang

2018-04-20

In this paper, piperazine-grafted reduced graphene oxide (NH-rGO) was synthesized via a simple and green two-step procedure: (i) opening of the resulting epoxides of graphene oxide (GO) with piperazine (NH) through nucleophilic substitution; (ii) reduction of GO with ascorbic acid. Its structure and morphology were characterized by scanning electron microscopy and x-ray photoelectron spectroscopy. The NH-rGO modified glassy carbon electrode was explored as an electrochemical sensor for the determination of Hg(II) using a differential pulse anodic stripping voltammetry technique. Hg(II) can be efficiently accumulated and deposited on the surface of a modified electrode by strong coordination chemical bonds formed between Hg(II) and NH. And then the anodic stripping current can be significantly enhanced by rGO with the merits of large specific surface area and high conductivity, which served as a signal amplifier, finally realizing the highly sensitive determination of Hg(II). The experimental parameters including the pH value of the acetate buffer, deposition potential and deposition time were optimized. Under optimal conditions, the developed sensor exhibited a wide linear range from 0.4-12 000 nM with a low limit of detection of 0.2 nM, which is well below the guideline value in drinking water set by the WHO. Moreover, the practical application of this method was confirmed by an assay of Hg(II) in tap water samples with acceptable results.

Differential pulse adsorptive stripping voltammetric determination of nanomolar levels of atorvastatin calcium in pharmaceutical and biological samples using a vertically aligned carbon nanotube/graphene oxide electrode.

PubMed

Silva, Tiago Almeida; Zanin, Hudson; Vicentini, Fernando Campanhã; Corat, Evaldo José; Fatibello-Filho, Orlando

2014-06-07

A novel vertically aligned carbon nanotube/graphene oxide (VACNT-GO) electrode is proposed, and its ability to determine atorvastatin calcium (ATOR) in pharmaceutical and biological samples by differential pulse adsorptive stripping voltammetry (DPAdSV) is evaluated. VACNT films were prepared on a Ti substrate by a microwave plasma chemical vapour deposition method and then treated with oxygen plasma to produce the VACNT-GO electrode. The oxygen plasma treatment exfoliates the carbon nanotube tips exposing graphene foils and inserting oxygen functional groups, these effects improved the VACNT wettability (super-hydrophobic) which is crucial for its electrochemical application. The electrochemical behaviour of ATOR on the VACNT-GO electrode was studied by cyclic voltammetry, which showed that it underwent an irreversible oxidation process at a potential of +1.08 V in pHcond 2.0 (0.2 mol L(-1) buffer phosphate solution). By applying DPAdSV under optimized experimental conditions the analytical curve was found to be linear in the ATOR concentration range of 90 to 3.81 × 10(3) nmol L(-1) with a limit of detection of 9.4 nmol L(-1). The proposed DPAdSV method was successfully applied in the determination of ATOR in pharmaceutical and biological samples, and the results were in close agreement with those obtained by a comparative spectrophotometric method at a confidence level of 95%.

Lead detection using micro/nanocrystalline boron-doped diamond by square-wave anodic stripping voltammetry.

PubMed

Arantes, Tatiane M; Sardinha, André; Baldan, Mauricio R; Cristovan, Fernando H; Ferreira, Neidenei G

2014-10-01

Monitoring heavy metal ion levels in water is essential for human health and safety. Electroanalytical techniques have presented important features to detect toxic trace heavy metals in the environment due to their high sensitivity associated with their easy operational procedures. Square-wave voltammetry is a powerful electrochemical technique that may be applied to both electrokinetic and analytical measurements, and the analysis of the characteristic parameters of this technique also enables the mechanism and kinetic evaluation of the electrochemical process under study. In this work, we present a complete optimized study on the heavy metal detection using diamond electrodes. It was analyzed the influence of the morphology characteristics as well as the doping level on micro/nanocrystalline boron-doped diamond films by means of square-wave anodic stripping voltammetry (SWASV) technique. The SWASV parameters were optimized for all films, considering that their kinetic response is dependent on the morphology and/or doping level. The films presented reversible results for the Lead [Pb (II)] system studied. The Pb (II) analysis was performed in ammonium acetate buffer at pH 4.5, varying the lead concentration in the range from 1 to 10 μg L(-1). The analytical responses were obtained for the four electrodes. However, the best low limit detection and reproducibility was found for boron doped nanocrystalline diamond electrodes (BDND) doped with 2000 mg L(-1) in B/C ratio. Copyright © 2014 Elsevier B.V. All rights reserved.

25 CFR 309.12 - What are examples of basketry that are Indian products?

Code of Federal Regulations, 2011 CFR

2011-04-01

..., spruce root, rye grass, sweet grass, yucca, bear grass, beach grass, rabbit brush, fiber, maidenhair fern..., pine needle/raffia effigy baskets, oak splint and braided sweet grass fancy baskets, birchbark containers, baleen baskets, rye grass dance fans, brown ash strawberry baskets, sumac wedding baskets, cedar...

25 CFR 309.12 - What are examples of basketry that are Indian products?

Code of Federal Regulations, 2010 CFR

2010-04-01

..., spruce root, rye grass, sweet grass, yucca, bear grass, beach grass, rabbit brush, fiber, maidenhair fern..., pine needle/raffia effigy baskets, oak splint and braided sweet grass fancy baskets, birchbark containers, baleen baskets, rye grass dance fans, brown ash strawberry baskets, sumac wedding baskets, cedar...

Shallow water table effects on water, sediment, and pesticide transport in vegetative filter strips - Part 2: model coupling, application, factor importance, and uncertainty

NASA Astrophysics Data System (ADS)

Lauvernet, Claire; Muñoz-Carpena, Rafael

2018-01-01

Vegetative filter strips are often used for protecting surface waters from pollution transferred by surface runoff in agricultural watersheds. In Europe, they are often prescribed along the stream banks, where a seasonal shallow water table (WT) could decrease the buffer zone efficiency. In spite of this potentially important effect, there are no systematic experimental or theoretical studies on the effect of this soil boundary condition on the VFS efficiency. In the companion paper (Muñoz-Carpena et al., 2018), we developed a physically based numerical algorithm (SWINGO) that allows the representation of soil infiltration with a shallow water table. Here we present the dynamic coupling of SWINGO with VFSMOD, an overland flow and transport mathematical model to study the WT influence on VFS efficiency in terms of reductions of overland flow, sediment, and pesticide transport. This new version of VFSMOD was applied to two contrasted benchmark field studies in France (sandy-loam soil in a Mediterranean semicontinental climate, and silty clay in a temperate oceanic climate), where limited testing of the model with field data on one of the sites showed promising results. The application showed that for the conditions of the studies, VFS efficiency decreases markedly when the water table is 0 to 1.5 m from the surface. In order to evaluate the relative importance of WT among other input factors controlling VFS efficiency, global sensitivity and uncertainty analysis (GSA) was applied on the benchmark studies. The most important factors found for VFS overland flow reduction were saturated hydraulic conductivity and WT depth, added to sediment characteristics and VFS dimensions for sediment and pesticide reductions. The relative importance of WT varied as a function of soil type (most important at the silty-clay soil) and hydraulic loading (rainfall + incoming runoff) at each site. The presence of WT introduced more complex responses dominated by strong interactions in the modeled system response, reducing the typical predominance of saturated hydraulic conductivity on infiltration under deep water table conditions. This study demonstrates that when present, the WT should be considered as a key hydrologic factor in buffer design and evaluation as a water quality mitigation practice.

The economic efficiency of conservation measures for amphibians in organic farming--results from bio-economic modelling.

PubMed

Schuler, Johannes; Sattler, Claudia; Helmecke, Angela; Zander, Peter; Uthes, Sandra; Bachinger, Johann; Stein-Bachinger, Karin

2013-01-15

This paper presents a whole farm bio-economic modelling approach for the assessment and optimisation of amphibian conservation conditions applied at the example of a large scale organic farm in North-Eastern Germany. The assessment focuses mainly on the habitat quality as affected by conservation measures such as through specific adapted crop production activities (CPA) and in-field buffer strips for the European tree frog (Hyla arborea), considering also interrelations with other amphibian species (i.e. common spadefoot toad (Pelobates fuscus), fire-bellied toad (Bombina bombina)). The aim of the approach is to understand, analyse and optimize the relationships between the ecological and economic performance of an organic farming system, based on the expectation that amphibians are differently impacted by different CPAs. The modelling system consists of a set of different sub-models that generate a farm model on the basis of environmentally evaluated CPAs. A crop-rotation sub-model provides a set of agronomically sustainable crop rotations that ensures overall sufficient nitrogen supply and controls weed, pest and disease infestations. An economic sub-model calculates the gross margins for each possible CPA including costs of inputs such as labour and machinery. The conservation effects of the CPAs are assessed with an ecological sub-model evaluates the potential negative or positive effect that each work step of a CPA has on amphibians. A mathematical programming sub-model calculates the optimal farm organization taking into account the limited factors of the farm (e.g. labour, land) as well as ecological improvements. In sequential model runs, the habitat quality is to be improved by the model, while the highest possible gross margin is still to be achieved. The results indicate that the model can be used to show the scope of action that a farmer has to improve habitat quality by reducing damage to amphibian population on its land during agricultural activities. Thereby, depending on the level of habitat quality that is aimed at, different measures may provide the most efficient solution. Lower levels of conservation can be achieved with low-cost adapted CPAs, such as an increased cutting height, reduced sowing density and grubbing instead of ploughing. Higher levels of conservation require e.g. grassland-like managed buffer strips around ponds in sensible areas, which incur much higher on-farm conservation costs. Copyright © 2012 Elsevier Ltd. All rights reserved.

76 FR 26927 - National Organic Program; Notice on the Ruminant Slaughter Stock Provision of the Access to...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-10

... Received on Labeling and Grass-Fed Products Many commenters suggested that there is a place for both grass... labeling system: ``Organic--Grass Fed/Grain Finished,'' ``Organic--Grass Fed/Finished on Pasture with Supplemental Grain Feeding,'' ``Organic--100% Grass Fed/Grass Finished.'' Their recommendation suggested that...

Exotic Grass Yields Under Southern Pines

Treesearch

H.A. Pearson

1975-01-01

Kentucky 31 and Kenwell tall fescue, Pensacola bahia, and Brunswick grasses yielded nea,rly three times more forage under an established pine stand than native grasses 7 years after seeding. Introducing exotic grasses did not significantly increase total grass production but did enhance range quality since the cool-season grasses are green during winter and are higher...

VAM populations in relation to grass invasion associated with forest decline.

PubMed

Vosatka, M; Cudlin, P; Mejstrik, V

1991-01-01

Spruce stands in Northern Bohemia forests, damaged to various degrees by industrial pollution, have shown establishment of grass cover following tree defoliation. Populations of vesicular-arbuscular mycorrhizal (VAM) fungi were studied under this grass cover in four permanent plots with spruce under different levels of pollution stress. Soil and root samples were collected in April and June within each plot as follows: (1) sites without grass, (2) sites with initial stages of grass invasion, and (3) sites with fully developed grass cover. In all plots, the highest number of propagules were recovered from samples taken from sites having full grass cover. Mycorrhizal infection of grass was highest in the plot with the severest pollution damage and lowest in the least damaged plot. The development of grass cover and VAM infection of grass increased with tree defoliation caused by air pollution.

Greenhouse studies on the phyto-extraction capacity of Cynodon nlemfuensis for lead and cadmium under irrigation with treated wastewater

NASA Astrophysics Data System (ADS)

Madyiwa, S.; Chimbari, M. J.; Schutte, C. F.; Nyamangara, J.

For over 30 years, discharge of sewage effluent and sludge on pasturelands has been used in Zimbabwe as a cheap method for secondary treatment of wastewater without any monitoring of accumulation of heavy metals in soils and grasses, let alone in animals grazing on the pastures. Cynodon nlemfuensis (star grass) has been the main grass planted on the wastewater irrigated pasturelands. This study was conducted to assess the capacity of star grass to accumulate lead (Pb) and cadmium (Cd) and develop models incorporating grass yield, metal uptake and soil bio-available (EDTA extractable) metal content, that could be used to determine critical grass and soil concentrations at which grass productivity declines. Star grass was planted in 30 fertilized pots containing sandy soil within a greenhouse. The pots consisted of nine treatments of varying levels of added inorganic Pb and Cd subjected to treated wastewater application and one control that had no added metals and received water application only. The elements were applied to the soils once just after planting the grass. Chemical analyses showed that star grass had a relatively high phyto-extraction capacity of Pb and Cd, comparable to that of hyper-accumulating grasses such as Lolium perenne (rye grass). It accumulated Pb and Cd to levels far beyond the recommended maximum limits for pasture grass. Analysis of variance on log-normal transformed data showed that bio-available soil metal concentrations correlated strongly with grass metal content and grass metal content correlated strongly with the yield. There was however a weak correlation between the yield and bio-available soil levels. The yield versus grass metal content models that were developed for the first crop and re-growth predicted similar critical metal concentrations and yields. Using the critical grass metal concentrations in the soil bio-available metal concentration versus grass metal concentration models allowed for the prediction of the corresponding critical soil concentrations.

Use of eyeballs for establishing ploidy of Asian carp

USGS Publications Warehouse

Jenkins, J.A.; Thomas, R.G.

2007-01-01

Grass carp Ctenopharyngodon idella, silver carp Hypophthalmichthys molitrix, and bighead carp H. nobilis are now established and relatively common in the Mississippi and Atchafalaya rivers. Commercial fishers of Louisiana's large rivers report recurrent catches of grass carp, and the frequency of bighead carp and silver carp catch is increasing. Twelve black carp Mylopharyngodon piceus were recently captured from the Mississippi and Atchafalaya River system, and 10 were analyzed for ploidy. By using the methods described herein, all 10 fish were determined to be diploid. Such correct identifications of ploidy of feral Asian carp species, as well as other species, would provide science-based information constructive for meeting reporting requirements, tracking fish movements, and forecasting expansion of species distribution. To investigate the postmortem period for sample collection and to lessen demands on field operations for obtaining samples, a laboratory study was performed to determine the length of time for which eyeballs from postmortem black carp could be used for ploidy determinations. Acquiring eyes rather than blood is simpler and quicker and requires no special supplies. An internal DNA reference standard with a documented genome size, including erythrocytes from diploid black carp or Nile tilapia Oreochromis niloticus, was analyzed simultaneously with cells from seven known triploid black carp to assess ploidy through 12 d after extraction. Ploidy determinations were reliable through 8 d postmortem. The field process entails excision of an eyeball, storage in a physiological buffer, and shipment within 8 d at refrigeration temperatures (4??C) to the laboratory for analysis by flow cytometry. ?? Copyright by the American Fisheries Society 2007.

Grass fungal endophytes and uses thereof

DOEpatents

Craven, Kelly

2015-03-10

The invention provides isolated fungal endophytes and synthetic combinations thereof with host grass plants. Methods for inoculating grass plant with the endophytes, for propagating the grass-endophyte combinations, and for producing feeds and biofuels from grass-endophyte combinations are also provided.

Sensitivity improvement in hydrophilic interaction chromatography negative mode electrospray ionization mass spectrometry using 2-(2-methoxyethoxy)ethanol as a post-column modifier for non-targeted metabolomics.

PubMed

Koch, Wendelin; Forcisi, Sara; Lehmann, Rainer; Schmitt-Kopplin, Philippe

2014-09-26

The application of ammonia acetate buffered liquid chromatography (LC) eluents is known to concomitantly lead to ion suppression when electrospray ionization mass spectrometry (ESI-MS) detection is used. In negative ESI mode, post column infusion of 2-(2-methoxyethoxy)ethanol (2-MEE) was shown in the literature to help to compensate this adverse effect occurring in reversed phase liquid chromatography mass spectrometry (RP-LC-MS) analyses. Here a setup of direct infusion and hydrophilic interaction chromatography (HILIC) post-column infusion experiments was established in order to investigate systematically the beneficial effects of 2-MEE. We demonstrate that, 2-MEE can help to improve ESI-MS sensitivity in HILIC too and reveal analyte structure specific behaviors. Our study indicates that 2-MEE especially improves ESI response for small and polar molecules. The ESI response of stable isotope labeled amino acids spiked into biological matrices increases up to 50-fold (i.e. D5-l-glutamic acid) when post column infusion of 2-MEE is applied. A non-targeted analysis of a pooled urine sample via HILIC-ESI-QTOF-MS supports this hypothesis. In direct infusion, the combined application of an ammonia acetate buffered solution together with 2-MEE results in an improved ESI response compared to a non-buffered solution. We observed up to 60-fold increased ESI response of l-lysine. We propose this effect is putatively caused by the formation of smaller ESI droplets and stripping of positive charge from ESI droplets due to evaporation of acetic acid anions. In summary, post-column infusion of 2-MEE especially enhances ESI response of small and polar molecules. Therefore it can be regarded as a valuable add-on in targeted or non-targeted metabolomic HILIC-MS studies since this method sets a focus on this molecule category. Copyright © 2014 Elsevier B.V. All rights reserved.

Controlled laboratory experiments and modeling of vegetative filter strips with shallow water tables

NASA Astrophysics Data System (ADS)

Fox, Garey A.; Muñoz-Carpena, Rafael; Purvis, Rebecca A.

2018-01-01

Natural or planted vegetation at the edge of fields or adjacent to streams, also known as vegetative filter strips (VFS), are commonly used as an environmental mitigation practice for runoff pollution and agrochemical spray drift. The VFS position in lowlands near water bodies often implies the presence of a seasonal shallow water table (WT). In spite of its potential importance, there is limited experimental work that systematically studies the effect of shallow WTs on VFS efficacy. Previous research recently coupled a new physically based algorithm describing infiltration into soils bounded by a water table into the VFS numerical overland flow and transport model, VFSMOD, to simulate VFS dynamics under shallow WT conditions. In this study, we tested the performance of the model against laboratory mesoscale data under controlled conditions. A laboratory soil box (1.0 m wide, 2.0 m long, and 0.7 m deep) was used to simulate a VFS and quantify the influence of shallow WTs on runoff. Experiments included planted Bermuda grass on repacked silt loam and sandy loam soils. A series of experiments were performed including a free drainage case (no WT) and a static shallow water table (0.3-0.4 m below ground surface). For each soil type, this research first calibrated VFSMOD to the observed outflow hydrograph for the free drainage experiments to parameterize the soil hydraulic and vegetation parameters, and then evaluated the model based on outflow hydrographs for the shallow WT experiments. This research used several statistical metrics and a new approach based on hypothesis testing of the Nash-Sutcliffe model efficiency coefficient (NSE) to evaluate model performance. The new VFSMOD routines successfully simulated the outflow hydrographs under both free drainage and shallow WT conditions. Statistical metrics considered the model performance valid with greater than 99.5% probability across all scenarios. This research also simulated the shallow water table experiments with both free drainage and various water table depths to quantify the effect of assuming the former boundary condition. For these two soil types, shallow WTs within 1.0-1.2 m below the soil surface influenced infiltration. Existing models will suggest a more protective vegetative filter strip than what actually exists if shallow water table conditions are not considered.

76 FR 33337 - Endangered Species Recovery Permit Applications

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-08

... No. TE-036090 Applicant: Virginia S. Moran, Grass Valley, California. The applicant requests a permit... sunburst), Orcutttia pilosa (hairy Orcutt grass), Orcuttia viscida (Sacramento Orcutt grass), Tuctoria greenei (Green's awnless Orcutt grass), Tuctoria mucronata (Mucronata Orcutt grass), and Sidalcea keckii...

40 CFR 180.547 - Prohexadione calcium; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... byproducts, except kidney 0.05 Grass, forage 1 0.10 Grass, hay 1 0.10 Grass, seed screenings 1 3.5 Grass... kidney 0.05 1Registration is limited to grass grown for seed. (b) Section 18 emergency exemptions...

40 CFR 180.547 - Prohexadione calcium; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... byproducts, except kidney 0.05 Grass, forage 1 0.10 Grass, hay 1 0.10 Grass, seed screenings 1 3.5 Grass... kidney 0.05 1Registration is limited to grass grown for seed. (b) Section 18 emergency exemptions...

75 FR 69666 - Granting of Request for Early Termination of the Waiting Period Under the Premerger Notification...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-15

....P. G Technicolor S.A. G Thomson 000. G Grass Valley Spain SA. G Brazil GV Newco. G Thomson Licensing SAS. G Grass Valley Germany GmbH. G Grass Valley Australia PTY Limited. G Grass Valley Singapore PTE Ltd. G Canopus Asia Co. Limited. G Grass Valley Canada, Inc. G US GV Newco (to be formed). G Grass...

The stakeholder preference for best management practices in the Three Gorges Reservoir Region.

PubMed

Qiu, Jiali; Shen, Zhenyao; Chen, Lei; Xie, Hui; Sun, Chengchun; Huang, Qin

2014-11-01

A qualitative analysis of in-depth interviews with 92 farmers and 42 policy managers in Wuxi County, the Three Gorges Reservoir Region, was conducted to identify stakeholder preferences for alternative best management practices (BMPs) and to determine the factors that affect their acceptance. Policy manager support for most of the practices was relatively stronger than support by farmers, except for the grade stabilization structure (GSS), hillside ditch (HD) and constructed wetland alternative, owing to their perceptions of soil benefits, economic advantages and environmental advantages. Farmers opposed those practices that occupied cultivated lands or changed the conventional planting methods, such as field border, conservation tillage (CT) and contour buffer strips. They tended to accept the BMPs with off-farm pollution reduction, such as GSS, riparian forest buffer and HD, and the BMPs associated with soil benefits, such as nutrient management and Terrace. The result that almost all respondents did not accept CT differed from reports in the existing literature. There is a significant correlation between the acceptance of some BMPs and the townships where the farmers lived (P ≤ 0.05). The environmental conditions and social factors would affect farmer support for BMPs, including local soil conditions, farming methods, economic income, education level and age. The economic advantages of the BMPs were the main motivation for farmers to accept the practices. Furthermore, intensive education efforts, financial incentives or economic subsidies may promote the adoption of the BMPs in our study area.

Copper-complexing ligands produced by an intact estuarine microbial community in response to copper stress.

NASA Astrophysics Data System (ADS)

Bingham, J.; Dryden, C.; Gordon, A.

2002-12-01

Copper is both an important nutrient and a pollutant in the marine environment. By studying the interactions between microorganisms and copper in the Elizabeth River (VA), home to a major Naval Base, we field tested the hypothesis that picoplankton and/or bacterioplankton produce strong, copper-complexing ligands in response to elevated copper concentrations. A simple light/ dark test was used to distinguish between heterotrophic and phototrophic ligand production. Samples were bottled and moored, submerged one meter, for a week. Direct counts using DAPI stain and epiflourescence were conducted to find concentrations of picoplankton and bacterioplankton. Using cathodic stripping voltammetry, we found the total copper concentrations, and then from a titration of the ligands by copper, the ligand concentrations and conditional stability constants were obtained. The Elizabeth River naturally had between 10-20 nM total dissolved copper concentrations. However when copper complexation was considered we found that the levels of bio-available Cu(II) ions were much lower. In fact in the natural samples the levels were not high enough to affect the relative reproductive rates of several microorganisms. Naturally there was a 50 nM "buffer zone" of ligand to total dissolved copper concentration. Furthermore, when stressed with excess copper, healthy picoplankton produced enough ligand to alleviate toxicity, and rebuild the buffer zone. However bacterioplankton only produced enough ligand so that they were no longer affected. Therefore, intact estuarine communities regulate copper bioavailability and toxicity with ligand production.

Peptide surface modification of P(HEMA-co-MMA)-b-PIB-b-P(HEMA-co-MMA) block copolymers.

PubMed

Ojha, Umaprasana; Feng, Dingsong; Chandekar, Amol; Whitten, James E; Faust, Rudolf

2009-06-02

Peptide surface modification of poly[(methyl methacrylate-co-hydroxyethyl methacrylate)-b-isobutylene-b-(methyl methacrylate-co-hydroxyethyl methacrylate)] P(MMA-co-HEMA)-b-PIB-b-P(MMA-co-HEMA) triblock copolymers with different HEMA/MMA ratios has been accomplished using an efficient synthetic procedure. The triblock copolymers were reacted with 4-fluorobenzenesulfonyl chloride (fosyl chloride) in pyridine to obtain the activated polymers [poly{(methyl methacrylate-co-fosyloxyethyl methacrylate)-b-isobutylene-b-(methyl methacrylate-co-fosyloxyethyl methacrylate)}] P(MMA-co-FEMA)-b-PIB-b-P(MMA-co-FEMA), with an activating efficiency of 80-90%. The resulting polymers were soluble in chloroform, and their solutions were used to coat thin uniform films with a predetermined thickness on smooth steel surfaces. The presence of reactive activating groups on the film surface was confirmed by X-ray photoelectron spectroscopy (XPS), dye labeling, and confocal laser scanning microscopic studies. Activation of the triblock copolymer films was also achieved under heterogeneous conditions in polar (acetonitrile) and nonpolar (hexanes) media. The extent of activation was controlled by varying the dipping time and polarity of the medium. Peptide attachment was accomplished by immersing the coated steel strips into aqueous buffer solution of Gly-Gly or GYIGSR. XPS and solubility studies revealed successful attachment of peptides to the polymer surface. Virtually all remaining activating groups were successfully replaced in the subsequent step by a treatment with Tris(hydroxymethyl)amino methane in a buffered methanol/water mixture.

The Stakeholder Preference for Best Management Practices in the Three Gorges Reservoir Region

NASA Astrophysics Data System (ADS)

Qiu, Jiali; Shen, Zhenyao; Chen, Lei; Xie, Hui; Sun, Chengchun; Huang, Qin

2014-11-01

A qualitative analysis of in-depth interviews with 92 farmers and 42 policy managers in Wuxi County, the Three Gorges Reservoir Region, was conducted to identify stakeholder preferences for alternative best management practices (BMPs) and to determine the factors that affect their acceptance. Policy manager support for most of the practices was relatively stronger than support by farmers, except for the grade stabilization structure (GSS), hillside ditch (HD) and constructed wetland alternative, owing to their perceptions of soil benefits, economic advantages and environmental advantages. Farmers opposed those practices that occupied cultivated lands or changed the conventional planting methods, such as field border, conservation tillage (CT) and contour buffer strips. They tended to accept the BMPs with off-farm pollution reduction, such as GSS, riparian forest buffer and HD, and the BMPs associated with soil benefits, such as nutrient management and Terrace. The result that almost all respondents did not accept CT differed from reports in the existing literature. There is a significant correlation between the acceptance of some BMPs and the townships where the farmers lived ( P ≤ 0.05). The environmental conditions and social factors would affect farmer support for BMPs, including local soil conditions, farming methods, economic income, education level and age. The economic advantages of the BMPs were the main motivation for farmers to accept the practices. Furthermore, intensive education efforts, financial incentives or economic subsidies may promote the adoption of the BMPs in our study area.

Environmental Assessment for Military Family Housing Privatization Initiative

DTIC Science & Technology

2006-01-01

grass Bouteloua radicosa Grama grass Bouteloua parryi Grama grass Bouteloua barbata Grama grass Cathestecum erectum False grama grass Aristida...Leptonycteris curasoae yerbabuenae Lesser long- nosed bat LE WSC Desert scrub habitat with agave and columnar cacti present as food plants. May Occur

AmeriFlux CA-Let Alberta - Mixed Grass Prairie

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flanagan, Lawrence B.

This is the AmeriFlux version of the carbon flux data for the site CA-Let Alberta - Mixed Grass Prairie. Site Description - Latitude 49.43° N; Longitude 112.56° W, altitude 951 meters,Mixed Grass Prairie that includes the following major species: Agropyron spp. (Wheat Grasses), Tragopogon dubius (Goat’s Beard), Vicia americana (Wild Vetch), Koleria cristata (June Grass), Eurotia lanata (Winter Fat), Stipa comata (Spear Grass), Achillea millefolium (Yarrow); Artemisia frigida (Pasture Sage); Carex spp. (Sedges), Bouteloua gracilis (Blue Grama Grass). Maximum canopy height varies from year to year

Responses of tropical native and invader C4 grasses to water stress, clipping and increased atmospheric CO2 concentration.

PubMed

Baruch, Zdravko; Jackson, Robert B

2005-10-01

The invasion of African grasses into Neotropical savannas has altered savanna composition, structure and function. The projected increase in atmospheric CO(2) concentration has the potential to further alter the competitive relationship between native and invader grasses. The objective of this study was to quantify the responses of two populations of a widespread native C(4) grass (Trachypogon plumosus) and two African C(4) grass invaders (Hyparrhenia rufa and Melinis minutiflora) to high CO(2) concentration interacting with two primary savanna stressors: drought and herbivory. Elevated CO(2) increased the competitive potential of invader grasses in several ways. Germination and seedling size was promoted in introduced grasses. Under high CO(2), the relative growth rate of young introduced grasses was twice that of native grass (0.58 g g(-1) week(-1) vs 0.25 g g(-1) week(-1)). This initial growth advantage was maintained throughout the course of the study. Well-watered and unstressed African grasses also responded more to high CO(2) than did the native grass (biomass increases of 21-47% compared with decreases of 13-51%). Observed higher water and nitrogen use efficiency of invader grasses may aid their establishment and competitive strength in unfertile sites, specially if the climate becomes drier. In addition, high CO(2) promoted lower leaf N content more in the invader grasses. The more intensive land use, predicted to occur in this region, may interact with high CO(2) to favor the African grasses, as they generally recovered faster after simulated herbivory. The superiority of invader grasses under high CO(2) suggests further increases in their competitive strength and a potential increased rate of displacement of the native savannas in the future by grasslands dominated by introduced African species.

A Tensile Strength of Bermuda Grass and Vetiver Grass in Terms of Root Reinforcement Ability Toward Soil Slope Stabilization

NASA Astrophysics Data System (ADS)

Noorasyikin, M. N.; Zainab, M.

2016-07-01

An examination on root characteristics and root properties has been implemented in this study. Two types of bioengineering were chose which are Vetiver grass and Bermuda grass as these grasses were widely applied for slope stabilization. The root samples were taken to the laboratory to investigate its classification, characteristics and strength. The root of both grasses was found grow with fibrous root matrix system. In terms of root anchorage, the root matrix system of Vetiver grass was exhibits more strengthen than the Bermuda grass. However, observation on root image from Scanning Electron Microscope test reveals that the root of Vetiver grass becomes non-porous as the moisture content reduced. Meanwhile, the root tensile strength of Bermuda grass was obtained acquired low value with higher percentage of moisture content, root morphology and bonding strength. The results indicated that the root tensile strength is mainly influence by percentage of moisture content and root morphology.

Physical and vegetative characteristics of a relocated stream reach, constructed wetland, and riparian buffer, Upper Saucon Township, Lehigh County, Pennsylvania, 2000-04

USGS Publications Warehouse

Chaplin, Jeffrey J.; White, Kirk E.; Loper, Connie A.

2006-01-01

The U.S. Geological Survey, in cooperation with the Pennsylvania Department of Transportation, Engineering District 5-0, investigated physical and vegetative changes within a relocated stream reach, constructed wetland, and riparian buffer from September 2000 to October 2004. This report presents an evaluation of data collected using methods from multiple sources that have been adapted into a consistent approach. This approach is intended to satisfy a need for consistent collection of different types of data with the goal of transferring technology and findings to similar projects. Survey data indicate that adjustment of the upstream part of the relocated stream reach slowed over the monitoring period, but the downstream channel remains unstable as evidenced by excessive deposition. Upstream migration of a nick point has slowed or stopped altogether as of the 2003 assessment when this feature came in contact with the upstream-most part of the channel that is lined with riprap. Documented streambed erosion in the upstream cross sections, along with deposition downstream, has resulted in an overall decrease in slope of the stream channel over the monitoring period. Most streambed erosion took place prior to the 2002 assessment when annual mean streamflows were less than those in the final 2 years of monitoring. An abundance of fine sediment dominates the substrate of the relocated channel. Annual fluctuations of large particles within each cross section demonstrates the capacity of the relocated channel to transport the entire range of sediment. The substrate within the 0.28-acre constructed wetland (a mixture of soil from an off-site naturally occurring wetland and woodchips) supported a hydrophytic-vegetation community throughout the investigation. Eleocharis obtusa (spike rush), an obligate-wetland herb, was the most prevalent species, having a maximum areal cover of 90 percent in fall 2001 and a minimum of 23 percent in fall 2004. Drought-like conditions in water year 2002 (cumulative precipitation was 28.11 inches) allowed species like Panicum dichotomiflorum (witch grass), Salix sp. (willow), Leersia oryzoides (rice cutgrass), and Echinocloa crusgalli (barnyard grass) to become established by fall 2002. Above-average precipitation in water years 2003 and 2004 (58.55 and 53.17 inches, respectively) coincided with increased areal cover by E. obtusa in fall 2003 (56 percent) and decreased areal cover in fall 2004 (23 percent). Pond-like conditions that probably persisted throughout the 2004 growing season favored aquatic species like Alisma subcordatum (water plantain) to the detriment of many emergent species, including E. obtusa. Despite the pond-like conditions, L. oryzoides, an obligate-wetland grass, increased in areal cover (from 12 to 34 percent) between the 2003 and 2004 growing seasons because it was established in the higher elevations and the peripheral areas of the constructed wetland that were less prone to persistent inundation. Canopy development by trees and shrubs in the riparian buffer was initially (fall 2000) poor (39.7 percent), resulting in more available sunlight for the herbaceous understory than in any other growing season. As a result, areal cover of herbaceous species and trees and shrubs less than 1-meter tall was 108 percent in fall 2000 with Lolium perenne (perennial rye), Polygonum persicaria (lady's thumb), and Setaria faberi (foxtail) collectively contributing nearly half the cover (59.2 percent). Because of increases in canopy cover by trees and shrubs (39.7 percent in fall 2000 to 127 percent in fall 2004), herbaceous cover decreased to 76 percent by the fall of 2001 and varied between 72 and 77 percent for the rest of the study period. Tree density in the riparian buffer ranged from 3,078 and 4,130 plants per acre (fall 2000 and 2003, respectively) over the study period but essentially remained constant after fall 2001; computations reported each fall between fall 2001 and fall 2004 are within 10 percent of one another. When the study ended in fall 2004, Acer negundo (box elder) and Fraxinus pennsylvanica (green ash) were the most populous tree species (1,526 and 1,084 plants per acre, respectively) followed by Quercus bicolor (swamp white oak; 720 plants per acre). A. negundo, F. pennsylvanica, and Q. bicolor also contributed the greatest areal cover in fall 2004 (31.2, 24.0, and 18.5 percent,respectively). 

40 CFR 180.34 - Tests on the amount of residue remaining.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., barley, oats, rice, rye (each in grain form). (25) Alfalfa, Bermuda grass, bluegrass, brome grass, clovers, cowpea hay, fescue, lespedeza, lupines, orchard grass, peanut hay, peavine hay, rye grass, soybean hay, sudan grass, timothy, and vetch. (26) Corn forage, sorghum forage. (27) Sugarcane, cane...

40 CFR 180.34 - Tests on the amount of residue remaining.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., barley, oats, rice, rye (each in grain form). (25) Alfalfa, Bermuda grass, bluegrass, brome grass, clovers, cowpea hay, fescue, lespedeza, lupines, orchard grass, peanut hay, peavine hay, rye grass, soybean hay, sudan grass, timothy, and vetch. (26) Corn forage, sorghum forage. (27) Sugarcane, cane...

Approximate strip exchanging.

PubMed

Roy, Swapnoneel; Thakur, Ashok Kumar

2008-01-01

Genome rearrangements have been modelled by a variety of primitives such as reversals, transpositions, block moves and block interchanges. We consider such a genome rearrangement primitive Strip Exchanges. Given a permutation, the challenge is to sort it by using minimum number of strip exchanges. A strip exchanging move interchanges the positions of two chosen strips so that they merge with other strips. The strip exchange problem is to sort a permutation using minimum number of strip exchanges. We present here the first non-trivial 2-approximation algorithm to this problem. We also observe that sorting by strip-exchanges is fixed-parameter-tractable. Lastly we discuss the application of strip exchanges in a different area Optical Character Recognition (OCR) with an example.

Low night temperature effect on photosynthate translocation of two C4 grasses.

PubMed

Potvin, C; Strain, B R; Goeschl, J D

1985-10-01

Translocation of assimilates in plants of Echinochloa crus-galli, from Quebec and Mississippi, and of Eleusine indica from Mississippi was monitored, before and after night chilling, using radioactive tracing with the short-life isotope 11 C. Plants were grown at 28°/22°C (day/night temperatures) under either 350 or 675 μl·l -1 CO 2 . Low night temperature reduced translocation mainly by increasing the turn-over times of the export pool. E. crus-galli plants from Mississippi were the most susceptible to chilling; translocation being completely inhibited by exposure for one night to 7°C at 350 μl·l -1 CO 2 . Overall, plants from Quebec were the most tolerant to chilling-stress. For plants of all three populations, growth under CO 2 enrichment resulted in higher 11 C activity in the leaf phloem. High CO 2 concentrations also seemed to buffer the transport system against chilling injuries.

Final Environmental Assessment For Wing Infrastructure Development Outlook (WINDO) Davis-Monthan Air Force Base, Tucson, Arizona

DTIC Science & Technology

2005-06-01

rothrockii Grama grass Bouteloua californica Grama grass Bouteloua radicosa Grama grass Bouteloua parryi Grama grass Bouteloua barbata Grama grass...with agave and columnar cacti present as food plants. May Occur Mammal Myotis velifer Cave myotis SC Desertscrub of creosote, brittlebush

50 CFR 21.52 - Public health control order for resident Canada geese.

Code of Federal Regulations, 2011 CFR

2011-10-01

... repellants, (G) Cervical dislocation, and (H) CO2 asphyxiation. (ii) Birds caught live may be euthanized or... lomatium, Contra Costa goldfields, Hoover's spurge, fleshy owl's clover, Colusa grass, hairy Orcutt grass, Solano grass, Greene's tuctoria, Sacramento Valley Orcutt grass, San Joaquin Valley Orcutt grass, slender...

75 FR 35801 - Notice of Receipt of Several Pesticide Petitions Filed for Residues of Pesticide Chemicals in or...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-23

....05 ppm; grass, hay at 0.05 ppm; and grass, forage at 1.5 ppm. An enforcement method for plants has...; sorghum, stover at 0.35 ppm; grass, hay at 2.5 ppm; and grass, forage at 10 ppm. The analytical method is... on sorghum, grain at 0.2 ppm; grass, hay at 5.0 ppm; and grass, forage at 18 ppm. Since bromoxynil...

Native Grasses as a Management Alternative on Vegetated Closure Caps

NASA Astrophysics Data System (ADS)

Kwit, Charles; Collins, Beverly

2008-06-01

Capped waste sites often are vegetated with commercial turf grasses to increase evapotranspiration and prevent erosion and possible exposure of the barrier. Fertilizer, frequent watering, and mowing may be required to establish the turf grass and prevent invasion by trees and shrubs. Oldfield vegetation of grasses and forbs is a possible sustainable alternative to turf grass communities. To determine if oldfield vegetation can establish on caps, we (1) compared establishment of a dominant oldfield grass and a commercial turf grass under different combinations of new closure cap management: spring or summer planting and presence or absence of amendments to alleviate drought (watering, mulch) or increase soil fertility (fertilizer, lime, a nitrogen-fixing legume); (2) surveyed existing caps to determine if oldfield species establish naturally; and (3) performed a greenhouse experiment to compare growth of two native grasses under low and amended (added water, soil nutrients) conditions. Both the commercial grass and oldfield species established under new cap conditions; fertilizer, water, and mulch improved vegetation establishment in spring or summer, but legumes decreased grass cover. In the greenhouse, both native grasses grew best with amendments; however, substantial stem and root length were obtained with no fertilizer and only once-weekly watering. Existing vegetated caps supported planted grasses and naturally established oldfield species. Overall, the results indicate native grasses can establish on new caps and oldfields can serve as a management model; further work is needed to determine the management strategy to maintain herbaceous vegetation and slow woody species invasion.

Treatment with grass allergen peptides improves symptoms of grass pollen-induced allergic rhinoconjunctivitis.

PubMed

Ellis, Anne K; Frankish, Charles W; O'Hehir, Robyn E; Armstrong, Kristen; Steacy, Lisa; Larché, Mark; Hafner, Roderick P

2017-08-01

Synthetic peptide immunoregulatory epitopes are a new class of immunotherapy to treat allergic rhinoconjunctivitis (ARC). Grass allergen peptides, comprising 7 synthetic T-cell epitopes derived from Cyn d 1, Lol p 5, Dac g 5, Hol l 5, and Phl p 5, is investigated for treatment of grass pollen-induced ARC. We sought to evaluate the efficacy, safety, and tolerability of intradermally administered grass allergen peptides. A multicenter, randomized, double-blind, placebo-controlled study evaluated 3 regimens of grass allergen peptides versus placebo in patients with grass pollen-induced allergy (18-65 years). After a 4-day baseline challenge to rye grass in the environmental exposure unit (EEU), subjects were randomized to receive grass allergen peptides at 6 nmol at 2-week intervals for a total of 8 doses (8x6Q2W), grass allergen peptides at 12 nmol at 4-week intervals for a total of 4 doses (4x12Q4W), or grass allergen peptides at 12 nmol at 2-week intervals for a total of 8 doses (8x12Q2W) or placebo and treated before the grass pollen season. The primary efficacy end point was change from baseline in total rhinoconjunctivitis symptom score across days 2 to 4 of a 4-day posttreatment challenge (PTC) in the EEU after the grass pollen season. Secondary efficacy end points and safety were also assessed. Two hundred eighty-two subjects were randomized. Significantly greater improvement (reduction of total rhinoconjunctivitis symptom score from baseline to PTC) occurred across days 2 to 4 with grass allergen peptide 8x6Q2W versus placebo (-5.4 vs -3.8, respectively; P = .0346). Greater improvement at PTC also occurred for grass allergen peptide 8x6Q2W versus placebo (P = .0403) in patients with more symptomatic ARC. No safety signals were detected. Grass allergen peptide 8x6Q2W significantly improved ARC symptoms after rye grass allergen challenge in an EEU with an acceptable safety profile. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Electrochemical lateral flow immunosensor for detection and quantification of dengue NS1 protein.

PubMed

Sinawang, Prima Dewi; Rai, Varun; Ionescu, Rodica E; Marks, Robert S

2016-03-15

An Electrochemical Lateral Flow Immunosensor (ELFI) is developed combining screen-printed gold electrodes (SPGE) enabling quantification together with the convenience of a lateral flow test strip. A cellulose glassy fiber paper conjugate pad retains the marker immunoelectroactive nanobeads which will bind to the target analyte of interest. The specific immunorecognition event continues to occur along the lateral flow bed until reaching the SPGE-capture antibodies at the end of the cellulosic lateral flow strip. The rationale of the immunoassay consists in the analyte antigen NS1 protein being captured selectively and specifically by the dengue NS1 antibody conjugated onto the immunonanobeads thus forming an immunocomplex. With the aid of a running buffer, the immunocomplexes flow and reach the immuno-conjugated electrode surface and form specific sandwich-type detection due to specific, molecular recognition, while unbound beads move along past the electrodes. The successful sandwich immunocomplex formation is then recorded electrochemically. Specific detection of NS1 is translated into an electrochemical signal contributed by a redox label present on the bead-immobilized detection dengue NS1 antibody while a proportional increase of faradic current is observed with increase in analyte NS1 protein concentration. The first generation ELFI prototype is simply assembled in a cassette and successfully demonstrates wide linear range over a concentration range of 1-25 ng/mL with an ultrasensitive detection limit of 0.5 ng/mL for the qualitative and quantitative detection of analyte dengue NS1 protein. Copyright © 2015 Elsevier B.V. All rights reserved.

Determination of tryptamine in foods using square wave adsorptive stripping voltammetry.

PubMed

Costa, Daniel J E; Martínez, Ana M; Ribeiro, Williame F; Bichinho, Kátia M; Di Nezio, María Susana; Pistonesi, Marcelo F; Araujo, Mario C U

2016-07-01

Tryptamine, a biogenic amine, is an indole derivative with an electrophilic substituent at the C3 position of the pyrrole ring of the indole moiety. The electrochemical oxidation of tryptamine was investigated using glassy carbon electrode (GCE), and focusing on trace level determination in food products by square wave adsorptive stripping voltammetry (SWAdSV). The electrochemical responses of tryptamine were evaluated using differing voltammetric techniques over a wide pH range, a quasi-reversible electron-transfer to redox system represented by coupled peaks P1-P3, and an irreversible reaction for peak P2 were demonstrated. The proton and electron counts associated with the oxidation reactions were estimated. The nature of the mass transfer process was predominantly diffusion-limited for the oxidation process of P1, the most selective and sensitive analytical response (acetate buffer solution pH 5.3), being used for the development of SWAdSV method, under optimum conditions. The excellent response allowed the development of an electroanalytical method with a linear response range of from 4.7-54.5)×10(-)(8)molL(-1), low detection limit (0.8×10(-)(9)molL(-)(1)), and quantification limit (2.7×10(-9)molL(-1)), and acceptable levels of repeatability (3.6%), and reproducibility (3.8%). Tryptamine content was determined in bananas, tomatoes, cheese (mozzarella and gorgonzola), and cold meats (chicken sausage and pepperoni sausage), yielding recoveries above 90%, with excellent analytical performance using simple and low cost instrumentation. Copyright © 2016 Elsevier B.V. All rights reserved.

Early presymptomatic cholinergic dysfunction in a murine model of amyotrophic lateral sclerosis

PubMed Central

Casas, Caty; Herrando-Grabulosa, Mireia; Manzano, Raquel; Mancuso, Renzo; Osta, Rosario; Navarro, Xavier

2013-01-01

Sporadic and familiar amyotrophic lateral sclerosis (ALS) cases presented lower cholinergic activity than in healthy individuals in their still preserved spinal motoneurons (MNs) suggesting that cholinergic reduction might occur before MN death. To unravel how and when cholinergic function is compromised, we have analyzed the spatiotemporal expression of choline acetyltransferase (ChAT) from early presymptomatic stages of the SOD1G93A ALS mouse model by confocal immunohistochemistry. The analysis showed an early reduction in ChAT content in soma and presynaptic boutons apposed onto MNs (to 76%) as well as in cholinergic interneurons in the lumbar spinal cord of the 30-day-old SOD1G93A mice. Cholinergic synaptic stripping occurred simultaneously to the presence of abundant surrounding major histocompatibility complex II (MHC-II)-positive microglia and the accumulation of nuclear Tdp-43 and the appearance of mild oxidative stress within MNs. Besides, there was a loss of neuronal MHC-I expression, which is necessary for balanced synaptic stripping after axotomy. These events occurred before the selective raise of markers of denervation such as ATF3. By the same time, alterations in postsynaptic cholinergic-related structures were also revealed with a loss of the presence of sigma-1 receptor, a Ca2+ buffering chaperone in the postsynaptic cisternae. By 2 months of age, ChAT seemed to accumulate in the soma of MNs, and thus efferences toward Renshaw interneurons were drastically diminished. In conclusion, cholinergic dysfunction in the local circuitry of the spinal cord may be one of the earliest events in ALS etiopathogenesis. PMID:23531559

Enhancement of lateral flow immunoassay by alkaline phosphatase: a simple and highly sensitive test for potato virus X.

PubMed

Panferov, Vasily G; Safenkova, Irina V; Varitsev, Yury A; Zherdev, Anatoly V; Dzantiev, Boris B

2017-12-06

Alkaline phosphatase (ALP) was used as an amplification tool in lateral flow immunoassay (LFIA). Potato virus Х (PVX) was selected as a target analyte because of its high economic importance. Two conjugates of gold nanoparticles were applied, one with mouse monoclonal antibody against PVX and one with ALP-labeled antibody against mouse IgG. They were immobilized to two fiberglass membranes on the test strip for use in LFIA. After exposure to the sample, a substrate for ALP (5-bromo-4-chloro-3-indolyl phosphate/nitro blue tetrazolium) was dropped on the test strip. The insoluble dark-violet diformazan produced by ALP precipitated on the membrane and significantly increased the color intensity of the control and test zones. The limit of detection (0.3 ng mL -1 ) was 27 times lower than that of conventional LFIA for both buffer and potato leaf extracts. The ALP-enhanced LFIA does not require additional preparation procedures or washing steps and may be used by nontrained persons in resource-limited conditions. The new method of enhancement is highly promising and may lead to application for routine LFIA in different areas. Graphical abstract Two gold nanoparticles (GNP) conjugates were used - the first with monoclonal antibodies (mAb) (GNP-mAb); the second - alkaline phosphatase-labeled antibody against mAb (GNP-anti-mAb-ALP). The immuno complexes are captured by the polyclonal antibodies (pAb) in the test zone. Addition of the substrate solution (BCIP/NBT) results in the accumulation of the insoluble colored product and in a significance increase in color intensity.

Development of colloidal gold-based immunochromatographic assay for rapid detection of Mycoplasma suis in porcine plasma.

PubMed

Meng, Kai; Sun, Wenjing; Zhao, Peng; Zhang, Limei; Cai, Dongjie; Cheng, Ziqiang; Guo, Huijun; Liu, Jianzhu; Yang, Dubao; Wang, Shujing; Chai, Tongjie

2014-05-15

A one-step immunochromatographic assay using gold nanoparticles coated with polyclonal antibody (pAb) against Mycoplasma suis (M. suis) was developed in this study for the detection of M. suis in porcine plasma. The colloidal gold was prepared by the reduction of gold salt with sodium citrate coupled with pAb against M. suis. The pAb was produced by immunizing the BALB/c mice with recombinant MSG1 (rMSG1) protein from M. suis expressed in Escherichia coli. The optimal concentrations of the capture antibody and the coating antibody were 12 μg/ml and 1.5 mg/ml, respectively, and that of the blocking buffer was 1% bovine serum albumin. The lower detection limit of the immunochromatographic assay test was 100 ng/ml with visual detection under optimal conditions of analysis. Classical swine fever virus, porcine reproductive and respiratory syndrome virus, swine pneumonia mycoplasma, swine toxoplasma, and porcine parvovirus were used to evaluate the specificity of the immunochromatographic strips. No cross-reaction of the antibodies with other related swine pathogens was observed. This qualitative test based on the visual evaluation of the results did not require any equipment. The assay time for M. suis detection was less than 10 min, suitable for rapid detection at the grassroots level. The one-step colloidal gold immunochromatographic strips that we developed had high specificity and sensitivity. Therefore, this method would be feasible, convenient, rapid, and effective for detecting M. suis in porcine plasma. Copyright © 2013 Elsevier B.V. All rights reserved.

A square-wave adsorptive stripping voltammetric method for determination of fast green dye.

PubMed

Al-Ghamdi, Ali F

2009-01-01

Square-wave adsorptive stripping voltammetric (SW-AdSV) determinations of trace concentrations of the coloring agent fast green were described. The analytical methodology used was based on the adsorptive preconcentration of the dye on the hanging mercury drop electrode, and then a negative sweep was initiated. In pH 10 carbonate supporting electrolyte, fast green gave a well-defined and sensitive SW-AdSV peak at -1220 mV. The electroanalytical determination of this dye was found to be optimized in carbonate buffer (pH 10) with the following experimental conditions: accumulation time (120 s); accumulation potential (-0.8 V); scan rate (800 mV/s); pulse amplitude (90 mV); frequency (90 Hz); surface area of the working electrode (0.6 mm2); and the convection rate (2000 rpm). Under these optimized conditions, the AdSV peak current was proportional over the concentration range 2 x 10(-8) -6 x 10(-7) M (r = 0.999), with an LOD of 1.63 x 10(-10) M (0.132 ppb). This analytical approach possessed more enhanced sensitivity than conventional chromatography or spectrophotometry, and was simple and quick. The precision of the method in terms of RSD was 0.17%, whereas the accuracy was evaluated via the mean recovery of 99.6%. Possible interferences by several substances usually present as food additive azo dyes (E110, E102, E123, and E129), natural and artificial sweeteners, and antioxidants were also investigated. Applicability of the developed electroanalysis method was illustrated via the determination of fast green in ice cream and soft drink samples.

Mechanisms of neurokinin A- and substance P-induced contractions in rat detrusor smooth muscle in vitro.

PubMed

Quinn, Teresa; Collins, Colm; Baird, Alan W

2004-09-01

To investigate the mechanisms of neurokinin A- and substance P-induced contractions of rat urinary bladder smooth muscle, and to compare them with those of the muscarinic agonist carbachol. Rat urinary bladder strips were suspended under 1 g of tension in a physiological buffer at 37 degrees C, gassed with 95% O(2)/5% CO(2). Mechanical activity was recorded isometrically during exposure to neurokinin A and substance P. Both agents produced concentration-dependent contractions of smooth muscle strips which were unaffected by tetrodotoxin (1 micro mol/L), peptidase inhibitors (captopril, thiorphan and bestatin; 1 micro mol/L each) or piroxicam (10 micro mol/L). The rank order of potency of agonists was neurokinin A > substance P > carbachol. Contractile responses to neurokinin A and substance P, like the contractile responses to carbachol, were abolished in a nominally Ca(2+)-free medium and significantly reduced by nifedipine (1 micro mol/L). SKF-96365 (60 micro mol/L), an inhibitor of receptor-mediated Ca(2+) entry, abolished the nifedipine-resistant response to substance P and carbachol, and significantly attenuated the response to neurokinin A. Depleting intracellular Ca(2+) stores with thapsigargin (1 micro mol/L) significantly attenuated neurokinin A-induced contractions but had no effect on substance P- or carbachol- induced contractions. The Rho-kinase inhibitor, Y-27632 (10 micro mol/L), significantly reduced both phasic and tonic components of the contractile responses to neurokinin A, substance P and carbachol. The contractile responses induced by tachykinins in rat urinary bladder smooth muscle strips involve a direct action on smooth muscle and are not modulated by peptidases or prostanoids. Neurokinin A and substance P, like carbachol-induced contractions, depend on extracellular Ca(2+) influx largely through voltage-operated and partly through receptor-operated Ca(2+) channels. Intracellular Ca(2+) release contributes to the contractile response to neurokinin A but appears to have no involvement in substance P- and carbachol-induced contractions. Rho-kinase activation contributes to contractions induced by substance P, neurokinin A and carbachol.

Endothelium-independent relaxant effect of Rubus coreanus extracts in corpus cavernosum smooth muscle.

PubMed

Lee, Jun Ho; Chae, Mee Ree; Sung, Hyun Hwan; Ko, Mikyeong; Kang, Su Jeong; Lee, Sung Won

2013-07-01

Rubus coreanus is a perennial shrub native to the southern part of the Korean peninsula. Although it is known that R. coreanus has a dose-dependent relaxation effect on rabbit corpus cavernosum (CC), the exact mechanism of action by which R. coreanus work is not fully known. To elucidate the direct effects of unripe R. coreanus extract (RCE) on CC smooth muscle cells. Dried unripe R. coreanus fruits were pulverized and extracted with 95% ethanol. Isolated rabbit CC strips were mounted in an organ-bath system, and the effects of RCE were evaluated. To estimate [Ca(2+)]i , we used a Fura-2 fluorescent technique. The effects of unripe RCE on ion channels and the intracellular Ca(2+) concentration ([Ca(2+)]i ) of CC. RCE effectively relaxed phenylephrine (PE)-induced tone in rabbit CC, and removal of the endothelium did not completely abolish the relaxation effect of RCE. Tetraethylammonium (1 mM) did not inhibit RCE-induced relaxation in strips precontracted by PE in the organ bath. However, CaCl2 -induced constriction of CC strips, bathed in Ca(2+)-free buffer and primed with PE, was abolished by RCE. In addition, RCE decreased basal [Ca(2+)]i in corporal smooth muscle cells. The increases of [Ca(2+)]i evoked by 60 mM K(+)-containing solution in A7r5 cells were suppressed by RCE, and RCE relaxed KCl-induced tone in endothelium-free CC, which indicated that RCE blocked the voltage-dependent Ca(2+) channels (VDCCs). RCE decreased basal [Ca(2+)]i and the [Arg8]-vasopressin-induced [Ca(2+)]i increases in A7r5 cells, and RCE inhibited the contraction of endothelium-free CC induced by PE in Ca(2+)-free solution, which suggested that RCE might act as a modulator of corporal smooth muscle cell tone by inhibiting Ca(2+) release from sarcoplasmic reticulum. RCE acts through endothelium-independent and endothelium-dependent pathways to relax CC. RCE may inhibit VDCCs and Ca(2+) release from sarcoplasmic reticulum. © 2013 International Society for Sexual Medicine.

Grass competition suppresses savanna tree growth across multiple demographic stages.

PubMed

Riginos, Corinna

2009-02-01

Savanna ecosystems, defined by the codominance of trees and grasses, cover one-fifth of the world's land surface and are of great socioeconomic and biological importance. Yet, the fundamental question of how trees and grasses coexist to maintain the savanna state remains poorly understood. Many models have been put forward to explain tree-grass coexistence, but nearly all have assumed that grasses do not limit tree growth and demography beyond the sapling stage. This assumption, however, has rarely been tested. Here I show that grass can strongly suppress the growth of trees. I removed grass around trees of three size classes in an Acacia drepanolobium savanna in Laikipia, Kenya. For even the largest trees, grass removal led to a doubling in growth and a doubling in the probability of transitioning to the next size class over two years. These results suggest that grass competition in productive (nutrient-rich) savannas may limit tree growth as much as herbivory and fire (the main factors thought to determine tree demography within a rainfall region) and should be incorporated into savanna models if tree-grass coexistence and savanna dynamics are to be understood.

Breeding bird territory placement in riparian wet meadows in relation to invasive reed canary grass, Phalaris arundinacea

USGS Publications Warehouse

Kirsch, E.M.; Gray, B.R.; Fox, T.J.; Thogmartin, W.E.

2007-01-01

Invasive plants are a growing concern worldwide for conservation of native habitats. In endangered wet meadow habitat in the Upper Midwestern United States, reed canary grass (Phalaris arundinacea) is a recognized problem and its prevalence is more widespread than the better-known invasive wetland plant purple loosestrife (Lythrum salicaria). Although resource managers are concerned about the effect of reed canary grass on birds, this is the first study to report how common wet meadow birds use habitat in relation to reed canary grass cover and dominance. We examined three response variables: territory placement, size of territories, and numbers of territories per plot in relation to cover of reed canary grass. Territory locations for Sedge Wren (Cistothorus platensis) and Song Sparrow (Melospiza melodia) were positively associated with reed canary grass cover, while those for Common Yellowthroat (Geothlypis trichas) were not. Only Swamp Sparrow (M. georgiana) territory locations were negatively associated with reed canary grass cover and dominance (which indicated a tendency to place territories where there was no reed canary grass or where many plant species occurred with reed canary grass). Swamp Sparrow territories were positively associated with vegetation height density and litter depth. Common Yellowthroat territories were positively associated with vegetation height density and shrub cover. Song Sparrow territories were negatively associated with litter depth. Reed canary grass cover within territories was not associated with territory size for any of these four bird species. Territory density per plot was not associated with average reed canary grass cover of plots for all four species. Sedge Wrens and Song Sparrows may not respond negatively to reed canary grass because this grass is native to wet meadows of North America, and in the study area it merely replaces other tall lush plants. Avoidance of reed canary grass by Swamp Sparrows may be mediated through their preference for wet areas where reed canary grass typically does not dominate. ?? 2007, The Society of Wetland Scientists.

Remote sensing of St. Augustine Decline (SAD) disease. [spectral reflectance of healthy and diseased grass

NASA Technical Reports Server (NTRS)

Odle, W. C.

1976-01-01

Laboratory and field spectral reflectance measurements of healthy and infected St. Augustine grass were made using several different instruments. Spectral differences between healthy and infected grass occured in the visible and near infrared regions. Multiband and color infrared photographs were taken of healthy and diseased turf from ground-based platforms and low altitude aircraft. Qualitative (density slicing) and quantitative (transmission densitometry) analyses revealed distinct tonal differences between healthy and St. Augustine disease (SAD) infected grass. Similar experiments are described for determining if healthy and diseased grass can be distinguished from waterstressed grass and grass deficient in either nitrogen or iron.

Preference for C4 shade grasses increases hatchling performance in the butterfly, Bicyclus safitza.

PubMed

Nokelainen, Ossi; Ripley, Brad S; van Bergen, Erik; Osborne, Colin P; Brakefield, Paul M

2016-08-01

The Miocene radiation of C4 grasses under high-temperature and low ambient CO 2 levels occurred alongside the transformation of a largely forested landscape into savanna. This inevitably changed the host plant regime of herbivores, and the simultaneous diversification of many consumer lineages, including Bicyclus butterflies in Africa, suggests that the radiations of grasses and grazers may be evolutionary linked. We examined mechanisms for this plant-herbivore interaction with the grass-feeding Bicyclus safitza in South Africa. In a controlled environment, we tested oviposition preference and hatchling performance on local grasses with C3 or C4 photosynthetic pathways that grow either in open or shaded habitats. We predicted preference for C3 plants due to a hypothesized lower processing cost and higher palatability to herbivores. In contrast, we found that females preferred C4 shade grasses rather than either C4 grasses from open habitats or C3 grasses. The oviposition preference broadly followed hatchling performance, although hatchling survival was equally good on C4 or C3 shade grasses. This finding was explained by leaf toughness; shade grasses were softer than grasses from open habitats. Field monitoring revealed a preference of adults for shaded habitats, and stable isotope analysis of field-sampled individuals confirmed their preference for C4 grasses as host plants. Our findings suggest that plant-herbivore interactions can influence the direction of selection in a grass-feeding butterfly. Based on this work, we postulate future research to test whether these interactions more generally contribute to radiations in herbivorous insects via expansions into new, unexploited ecological niches.

Facilitation or Competition? Tree Effects on Grass Biomass across a Precipitation Gradient

PubMed Central

Moustakas, Aristides; Kunin, William E.; Cameron, Tom C.; Sankaran, Mahesh

2013-01-01

Savanna ecosystems are dominated by two distinct plant life forms, grasses and trees, but the interactions between them are poorly understood. Here, we quantified the effects of isolated savanna trees on grass biomass as a function of distance from the base of the tree and tree height, across a precipitation gradient in the Kruger National Park, South Africa. Our results suggest that mean annual precipitation (MAP) mediates the nature of tree-grass interactions in these ecosystems, with the impact of trees on grass biomass shifting qualitatively between 550 and 737 mm MAP. Tree effects on grass biomass were facilitative in drier sites (MAP≤550 mm), with higher grass biomass observed beneath tree canopies than outside. In contrast, at the wettest site (MAP = 737 mm), grass biomass did not differ significantly beneath and outside tree canopies. Within this overall precipitation-driven pattern, tree height had positive effect on sub-canopy grass biomass at some sites, but these effects were weak and not consistent across the rainfall gradient. For a more synthetic understanding of tree-grass interactions in savannas, future studies should focus on isolating the different mechanisms by which trees influence grass biomass, both positively and negatively, and elucidate how their relative strengths change over broad environmental gradients. PMID:23451137

Ecophysiological responses of native and invasive grasses to simulated warming and drought

NASA Astrophysics Data System (ADS)

Ravi, S.; Law, D. J.; Wiede, A.; Barron-Gafford, G. A.; Breshears, D. D.; Dontsova, K.; Huxman, T. E.

2011-12-01

Climate models predict that many arid regions around the world - including the North American deserts - may become affected more frequently by recurrent droughts. At the same time, these regions are experiencing rapid vegetation transformations such as invasion by exotic grasses. Thus, understanding the ecophysiological processes accompanying exotic grass invasion in the context of rising temperatures and recurrent droughts is fundamental to global change research. Under ambient and warmer (+ 4° C) conditions inside the Biosphere 2 facility, we compared the ecophysiological responses (e.g. photosynthesis, stomatal conductance, pre-dawn leaf water potential, light & CO2 response functions, biomass) of a native grass - Heteropogan contortus (Tangle head) and an invasive grass - Pennisetum ciliare (Buffel grass) growing in single and mixed communities. Further, we monitored the physiological responses and mortality of these plant communities under moisture stress conditions, simulating a global change-type-drought. The results indicate that the predicted warming scenarios may enhance the invasibility of desert landscapes by exotic grasses. In this study, buffel grass assimilated more CO2 per unit leaf area and out-competed native grasses more efficiently in a warmer environment. However, scenarios involving a combination of drought and warming proved disastrous to both the native and invasive grasses, with drought-induced grass mortality occurring at much shorter time scales under warmer conditions.

Fusarium graminearum: pathogen or endophyte of North American grasses?

PubMed

Lofgren, Lotus A; LeBlanc, Nicholas R; Certano, Amanda K; Nachtigall, Jonny; LaBine, Kathryn M; Riddle, Jakob; Broz, Karen; Dong, Yanhong; Bethan, Bianca; Kafer, Christopher W; Kistler, H Corby

2018-02-01

Mycotoxin-producing Fusarium graminearum and related species cause Fusarium head blight on cultivated grasses, such as wheat and barley. However, these Fusarium species may have had a longer evolutionary history with North American grasses than with cultivated crops and may interact with the ancestral hosts in ways which are biochemically distinct. We assayed 25 species of asymptomatic native grasses for the presence of Fusarium species and confirmed infected grasses as hosts using re-inoculation tests. We examined seed from native grasses for the presence of mycotoxin-producing Fusarium species and evaluated the ability of these fungi to produce mycotoxins in both native grass and wheat hosts using biochemical analysis. Mycotoxin-producing Fusarium species were shown to be prevalent in phylogenetically diverse native grasses, colonizing multiple tissue types, including seeds, leaves and inflorescence structures. Artificially inoculated grasses accumulated trichothecenes to a much lesser extent than wheat, and naturally infected grasses showed little to no accumulation. Native North American grasses are commonly inhabited by Fusarium species, but appear to accommodate these toxigenic fungi differently from cultivated crops. This finding highlights how host identity and evolutionary history may influence the outcome of plant-fungal interactions and may inform future efforts in crop improvement. No claim to original US Government works. New Phytologist © 2017 New Phytologist Trust.

78 FR 54658 - Allergenic Products Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-05

... Vernal Grass, Perennial Ryegrass, Timothy Grass, Orchard Grass, and Kentucky Bluegrass Mixed Pollens... Grastek, a Timothy Grass Pollen Allergen Extract tablet for sublingual use, manufactured by Merck. FDA...

Spatiotemporal Variation in the Environmental Controls of C4-Grass Origin and Ecology: Insights from Grass-Pollen δ13C Data

NASA Astrophysics Data System (ADS)

Nelson, D. M.; Urban, M.; Hu, F.

2014-12-01

Understanding the environmental factors controlling the origin and shifting abundance of C4 grasses in Earth's history is useful for projecting the response of C4-grass dominated grasslands to future environmental change. Unfortunately, grass pollen is typically morphologically indistinct, making palynological analysis a blunt tool for studying C4-grasses in the paleorecord. δ13C of individual grass-pollen grains using a spooling wire microcombustion device interfaced with an isotope ratio mass spectrometer (Single Pollen Isotope Ratio AnaLysis, SPIRAL) overcomes this challenge and the potential biases of δ13C data from other substrates (e.g. leaf waxes). To assess the presence and relative abundance of C3- and C4-grass pollen in samples of unknown composition, we developed a hierarchical Bayesian model, trained with ~1,900 δ13C values from pollen grains of 31 grass species. Surface-sediment data from Africa, Australia, and North America demonstrate the reliability of this technique for quantifying C4-grass abundance on the landscape. To investigate the timing and control of the origin of C4-grasses we analyzed samples from the Oligocene-Miocene from Europe and from the Eocene from North America. Results indicate that C4 grasses appeared on the landscape of southwest Europe no later than the early Oligocene, implying that low atmospheric pCO2 may not have been the main driver and/or precondition for the development of C4 photosynthesis in the grass family. In contrast, we found no evidence for C4 grasses in the southeast United States before pCO2 fell. In application of SPIRAL to the late Quaternary, we found that shifts in pCO2 and moisture balance exerted key controls on the relative abundance of C3 and C4 grasses in Africa and Australia. Overall, our results imply that as in the past, future changes in the C3/C4 composition of grass-dominated ecosystems will likely exhibit striking spatiotemporal variability as a result of differing combinations of environmental controls.

First report of crown rust (Puccinia coronata var. gibberosa) on blue oat grass (Helictotrichon sempervirens) in the United States

USDA-ARS?s Scientific Manuscript database

Ornamental grasses are popular decorative plants, with sales valued at $124 million in the U. S. in 2009. One common ornamental grass is blue oat grass, Helictotrichon sempervirens (Vill.) Pilg., a large blue-green grass native to Europe. In 2011, H. sempervirens plants in a commercial nursery in ...

75 FR 80343 - Extension of Tolerances for Emergency Exemptions (Multiple Chemicals)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-22

... Timothy grass for control of Banks grass mite in Nevada. This regulation extends time-limited tolerances... fenoxaprop-ethyl in or on grass grown for seed for control of noxious weed species in Oregon. This regulation... on grass forage and grass hay at 0.05 ppm for an additional 3-year period. These tolerances will...

Shade Tolerance of Festuca paradoxa Desv., a Cool-Season Grass Native to North America

Treesearch

Nadia Navarrete-Tindall; Larry Mechlin; J. W. Van Sambeek

2003-01-01

Paradox grass (Festuca paradoxa Desv.) is a native cool-season grass found in prairies and forest openings. Paradox grass has not been included in tree plantings. To determine paradox grass adaptation to shaded environmmts, we established a pot experiment in the shade laboratory at the University of Missouri Horticulture and Agroforestry Research...

75 FR 17573 - Nicosulfuron; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

..., meat byproducts; goat, fat; goat, meat; goat, meat byproducts; grass, forage; grass, hay; horse, fat... grass, forage at 9.0 parts per million (ppm); grass, hay at 25.0 ppm; fat (of cattle, goat, hog, horse... at 0.05 ppm; goat, fat at 0.01 ppm; goat, meat at 0.01 ppm; goat, meat byproducts at 0.05 ppm; grass...

77 FR 12740 - Trinexapac-ethyl; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-02

... CGA-179500, in or on grass, forage, grown for seed at 1.60 parts per million (ppm); grass, hay, grown for seed at 3.5 ppm; grass, seed screenings, grown for seed at 45.0 ppm; grass, straw, grown for seed..., Sugarcane, and Grasses Grown for Seed'' p. 48 in docket ID number EPA-HQ-OPP-2010-0524. B. Toxicological...

Rainfall interception by annual grass and chaparral . . . losses compared

Treesearch

Edward S. Corbett; Robert P. Crouse

1968-01-01

Loss of precipitation due to interception by annual grass and grass litter was measured during three rainy seasons on the San Dimas Experimental Forest, in southern California. Interception loss from annual grass averaged 7.9 percent; that from mature chaparral cover, 12.8 percent. If chaparral stands were converted to grass, an estimated 1.3 inches of gross...

Climate, phylogeny and the ecological distribution of C4 grasses.

PubMed

Edwards, Erika J; Still, Christopher J

2008-03-01

'C4 photosynthesis' refers to a suite of traits that increase photosynthesis in high light and high temperature environments. Most C4 plants are grasses, which dominate tropical and subtropical grasslands and savannas but are conspicuously absent from cold growing season climates. Physiological attributes of C4 photosynthesis have been invoked to explain C4 grass biogeography; however, the pathway evolved exclusively in grass lineages of tropical origin, suggesting that the prevalence of C4 grasses in warm climates could be due to other traits inherited from their non-C4 ancestors. Here we investigate the relative influences of phylogeny and photosynthetic pathway in determining the ecological distributions of C4 grasses in Hawaii. We find that the restriction of C4 grasses to warmer areas is due largely to their evolutionary history as members of a warm-climate grass clade, but that the pathway does appear to confer a competitive advantage to grasses in more arid environments.

The use of food waste-based diets and Napier grass to culture grass carp: growth performance and contaminants contained in cultured fish.

PubMed

Cheng, Zhang; Mo, Wing-Yin; Nie, Xiang-Ping; Li, Kai-Bing; Choi, Wai-Ming; Man, Yu-Bon; Wong, Ming-Hung

2016-04-01

The present study used commercial feeds, food waste feeds, Napier grass, and mixed feeds (food waste feed to Napier grass ratio, 1:10) to feed grass carp (Ctenopharyngodon idellus). The results indicated that grass carp fed with food waste feeds and mix feeds achieved growth performance (based on specific growth rate and feed conversion ratio) that was similar to commercial feeds (p > 0.05). Concentrations of metalloid/metals in food waste feeds and polycyclic aromatic hydrocarbons (PAHs) in Napier grass were relatively higher than other types of fish feeds (p < 0.05). However, most of the metalloid/metals and PAH levels in fish fed with four types of fish feeds were not significantly different (p > 0.05). These findings show that food waste feeds are suitable for using in the production of fish feed and Napier grass can be served as supplemental feeds for grass carp, and hence reducing the production cost.

Stable Carbon Isotope Ratios of Individual Pollen Grains as a Proxy for C3- Versus C4-Grass Abundance in Paleorecords: A Validation Study

NASA Astrophysics Data System (ADS)

Nelson, D. M.; Hu, F.; Pearson, A.

2007-12-01

C3 and C4 grasses have distinct influences on major biogeochemical processes and unique responses to important environmental controls. Difficulties in distinguishing between these two functional groups of grasses have hindered paleoecological studies of grass-dominated ecosystems. We recently developed a technique to analyze the stable carbon isotope composition of individual grass-pollen grains using a spooling- wire microcombustion device interfaced with an isotope-ratio mass spectrometer (Nelson et al. 2007). This technique holds promise for improving C3 and C4 grass reconstructions. It requires ~90% fewer grains than typical methods and avoids assumptions associated with mixing models. However, our previous work was based on known C3 and C4 grasses from herbarium specimens and field collections and the technique had not been test using geological samples. To test the ability of this technique to reproduce the abundance of C3 and C4 grasses on the landscape, we measured δ13C values of >1500 individual grains of grass pollen isolated from the surface sediments of 10 North American lakes that span a large gradient of C3 and C4 grass abundance. Results indicate a strong positive correlation (r=0.94) between % C4-grass pollen (derived from classifying δ13C values from single grains as C3 and C4) and the literature-reported abundance of C4 grasses on the landscape. However, the measured % C4-grass pollen shows some deviation from the actual abundance at sites with high proportions of C4 grasses. This is likely caused by uncertainty in the magnitude, composition, and variability of the analytical blank associated with these measurements. Correcting for this deviation using regression analysis improves the estimation of the abundance of C4 grasses on the landscape. Comparison of the % C4-grass pollen with C/N and δ13C measurements of total organic matter in the same lake-sediment samples illustrates the distinct advantage of grass-pollen δ13C as a proxy for distinguishing C3 and C4 shifts. At 9 of the 10 sites C/N values indicate that surface-sediment organic matter was derived primarily from aquatic production. At the one site where organic matter was produced primarily by vascular plants the δ13C value (-29.3°) suggests organic matter derived exclusively from C3 plants. However, ~80% of the grasses on the landscape at this site are C4 grasses. The C3- like bulk-sediment δ13C value likely represents woody species, which comprise >90% of the pollen spectra. Thus δ13C analysis of single grains of grass pollen offers a new tool to classify grass pollen into two major functional groups and promises to advance our understanding of grassland ecology and evolution. Reference Nelson, D.M., Hu, F.S., Mikucki, J., Tian, J., and Pearson, A., 2007, Carbon isotopic analysis of individual pollen grains from C3 and C4 grasses using a spooling wire microcombustion interface: Geochimica et Cosmochimica Acta, v. 71, p. 4005-4014.

Rooting depth varies differentially in trees and grasses as a function of mean annual rainfall in an African savanna.

PubMed

Holdo, Ricardo M; Nippert, Jesse B; Mack, Michelle C

2018-01-01

A significant fraction of the terrestrial biosphere comprises biomes containing tree-grass mixtures. Forecasting vegetation dynamics in these environments requires a thorough understanding of how trees and grasses use and compete for key belowground resources. There is disagreement about the extent to which tree-grass vertical root separation occurs in these ecosystems, how this overlap varies across large-scale environmental gradients, and what these rooting differences imply for water resource availability and tree-grass competition and coexistence. To assess the extent of tree-grass rooting overlap and how tree and grass rooting patterns vary across resource gradients, we examined landscape-level patterns of tree and grass functional rooting depth along a mean annual precipitation (MAP) gradient extending from ~ 450 to ~ 750 mm year -1 in Kruger National Park, South Africa. We used stable isotopes from soil and stem water to make inferences about relative differences in rooting depth between these two functional groups. We found clear differences in rooting depth between grasses and trees across the MAP gradient, with grasses generally exhibiting shallower rooting profiles than trees. We also found that trees tended to become more shallow-rooted as a function of MAP, to the point that trees and grasses largely overlapped in terms of rooting depth at the wettest sites. Our results reconcile previously conflicting evidence for rooting overlap in this system, and have important implications for understanding tree-grass dynamics under altered precipitation scenarios.

Carbon Nanotube Tape Vibrating Gyroscope

NASA Technical Reports Server (NTRS)

Tucker, Dennis Stephen (Inventor)

2016-01-01

A vibrating gyroscope includes a piezoelectric strip having length and width dimensions. The piezoelectric strip includes a piezoelectric material and carbon nanotubes (CNTs) substantially aligned and polled along the strip's length dimension. A spindle having an axis of rotation is coupled to the piezoelectric strip. The axis of rotation is parallel to the strip's width dimension. A first capacitance sensor is mechanically coupled to the spindle for rotation therewith. The first capacitance sensor is positioned at one of the strip's opposing ends and is spaced apart from one of the strip's opposing faces. A second capacitance sensor is mechanically coupled to the spindle for rotation therewith. The second capacitance sensor is positioned at another of the strip's opposing ends and is spaced apart from another of the strip's opposing faces. A voltage source applies an AC voltage to the piezoelectric strip.

Fiber Reinforced Composite Cores and Panels

NASA Technical Reports Server (NTRS)

Day, Stephen W. (Inventor); Campbell, G. Scott (Inventor); Tilton, Danny E. (Inventor); Stoll, Frederick (Inventor); Sheppard, Michael (Inventor); Banerjee, Robin (Inventor)

2013-01-01

A fiber reinforced core panel is formed from strips of plastics foam helically wound with layers of rovings to form webs which may extend in a wave pattern or may intersect transverse webs. Hollow tubes may replace foam strips. Axial rovings cooperate with overlying helically wound rovings to form a beam or a column. Wound roving patterns may vary along strips for structural efficiency. Wound strips may alternate with spaced strips, and spacers between the strips enhance web buckling strength. Continuously wound rovings between spaced strips permit folding to form panels with reinforced edges. Continuously wound strips are helically wrapped to form annular structures, and composite panels may combine both thermoset and thermoplastic resins. Continuously wound strips or strip sections may be continuously fed either longitudinally or laterally into molding apparatus which may receive skin materials to form reinforced composite panels.

78 FR 70864 - Metaldehyde; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-27

... plus cob with husks removed at 0.05 ppm; grass, forage at 1.5 ppm; grass, hay at 1.8 ppm; leaf petioles...: ``Metaldehyde; Human Health Risk Assessment for Proposed Uses on Grass Grown for Seed, Leaf Petioles [Crop....10 ppm; grass, forage from 1.5 ppm to 2.0 ppm; grass, hay from 1.8 ppm to 2.0 ppm; leaf petioles...

Evaluation of molecular basis of cross reactivity between rye and Bermuda grass pollen allergens.

PubMed

Tiwari, Ruby; Bhalla, Prem L; Singh, Mohan B

2009-12-01

Allergenic cross reactivity between the members of the Pooids (Lolium perenne, Phleum pratense, and Poa pratensis) and Chloridoids (Cynodon dactylon and Paspalum notatum) is well established. Studies using crude extracts in the past have demonstrated limited cross reactivity between the Pooids and the Chloridoids suggesting separate diagnosis and therapy. However, little is known regarding the molecular basis for the limited cross reactivity observed between the 2 groups of grasses. The present study was undertaken to gain insights into the molecular basis of cross allergenicity between the major allergens from rye and Bermuda grass pollens. Immunoblot inhibition tests were carried out to determine the specificity of the proteins involved in cross reactivity. Crude pollen extract and bacterially expressed and purified recombinant Lol p 1and Lol p 5 from rye grass were subjected to cross inhibition experiments with crude and purified recombinant Cyn d 1 from Bermuda grass using sera from patients allergic to rye grass pollen. The immunoblot inhibition studies revealed a high degree of cross inhibition between the group 1 allergens. In contrast, a complete lack of inhibition was observed between Bermuda grass group 1 allergen rCyn d 1, and rye grass group 5 allergen rLol p 5. Crude rye grass extract strongly inhibited IgE reactivity to Bermuda grass, whereas crude Bermuda grass pollen extract showed a weaker inhibition. Our data suggests that a possible explanation for the limited cross reactivity between the Pooids and Chloridoids may, in part, be due to the absence of group 5 allergen from Chloridoid grasses. This approach of using purified proteins may be applied to better characterize the cross allergenicity patterns between different grass pollen allergens.

Agricultural runoff pollution control by a grassed swales coupled with wetland detention ponds system: a case study in Taihu Basin, China.

PubMed

Zhao, Jinhui; Zhao, Yaqian; Zhao, Xiaoli; Jiang, Cheng

2016-05-01

The performance of a field grassed swales (GSs) coupled with wetland detention ponds (WDPs) system was monitored under four typical rainfall events to assess its effectiveness on agricultural runoff pollution control in Taihu Basin, China. The results indicated that suspended solids (SS) derived from the flush process has significant influence on pollution loads in agricultural runoff. Determination of first flush effect (FFE) indicated that total suspended solids (TSS) and total phosphorus (TP) exhibited moderate FFE, while chemical oxygen demand (COD) and total nitrogen (TN) showed weak FFE. Average removal efficiencies of 83.5 ± 4.5, 65.3 ± 6.8, 91.6 ± 3.8, and 81.3 ± 5.8 % for TSS, COD, TN, and TP were achieved, respectively. The GSs played an important role in removing TSS and TP and acted as a pre-treatment process to prevent clogging of the subsequent WDPs. Particle size distributions (PSDs) analysis indicated that coarse particles larger than 75 μm accounted for 80 % by weight of the total particles in the runoff. GSs can effectively reduce coarse particles (≥75 μm) in runoff, while its removal efficiency for fine particles (<75 μm) was low, even minus results being recorded, especially for particles smaller than 25 μm. The length of GSs is a key factor in its performance. The WDPs can remove particles of all sizes by sedimentation. In addition, WDPs can improve water quality due to their buffering and dilution capacity during rainfall as well as their water purification ability during dry periods. Overall, the ecological system of GSs coupled with WDPs is an effective system for agricultural runoff pollution control.

Adsorption stripping voltammetry of phenol at Nafion-modified glassy carbon electrode in the presence of surfactants.

PubMed

Yi, H; Wu, K; Hu, S; Cui, D

2001-12-24

In this paper, a new voltammetric method for the determination of phenol is described. In pH 8.00 phosphate buffer and in the presence of long-chain cationic surfactant-cetyltrimethylammonium bromide-phenol has a very sensitive oxidation peak at 0.47 V (vs. SCE) on the Nafion-modified glassy carbon electrode (GCE). The experimental parameters, such as supporting electrolyte and pH values, amounts of Nafion, varieties and concentration of surfactants, accumulation potential and time, as well as scan rate were optimized. The peak current is linear with the concentration of phenol in the range from 8x10(-9) to 1x10(-5) M, and the detection limit is 1x10(-9) M after being accumulated at -0.50 V (vs. SCE) for 3 min. Trace levels of phenol in water samples were determined by using this voltammetric method, the average recovery was calculated to be 99.56%.

Effects of best-management practices in Bower Creek in the East River priority watershed, Wisconsin, 1991-2009

USGS Publications Warehouse

Corsi, Steven R.; Horwatich, Judy A.; Rutter, Troy D.; Bannerman, Roger T.

2013-01-01

Hydrologic and water-quality data were collected at Bower Creek during the periods before best-management practices (BMPs), and after BMPs were installed for evaluation of water-quality improvements. The monitoring was done between 1990 and 2009 with the pre-BMP period ending in July 1994 and the post-BMP period beginning in October 2006. BMPs installed in this basin included streambank protection and fencing, stream crossings, grade stabilization, buffer strips, various barnyard-runoff controls, nutrient management, and a low degree of upland BMPs. Water-quality evaluations included base-flow concentrations and storm loads for total suspended solids, total phosphorus, and ammonia nitrogen. The only reductions detected between the base-flow samples of the pre- and post-BMP periods were in median concentrations of total phosphorus from base-flow samples, but not for total suspended solids or dissolved ammonia nitrogen. Differences in storm loads for the three water-quality constituents monitored were not observed during the study period.

Survivability characteristics of composite compression structure

NASA Technical Reports Server (NTRS)

Avery, John G.; Allen, M. R.; Sawdy, D.; Avery, S.

1990-01-01

Test and evaluation was performed to determine the compression residual capability of graphite reinforced composite panels following perforation by high-velocity fragments representative of combat threats. Assessments were made of the size of the ballistic damage, the effect of applied compression load at impact, damage growth during cyclic loading and residual static strength. Several fiber/matrix systems were investigated including high-strain fibers, tough epoxies, and APC-2 thermoplastic. Additionally, several laminate configurations were evaluated including hard and soft laminates and the incorporation of buffer strips and stitching for improved damage resistance of tolerance. Both panels (12 x 20-inches) and full scale box-beam components were tested to assure scalability of results. The evaluation generally showed small differences in the responses of the material systems tested. The soft laminate configurations with concentrated reinforcement exhibited the highest residual strength. Ballistic damage did not grow or increase in severity as a result of cyclic loading, and the effects of applied load at impact were not significant under the conditions tested.

Bacterial RNA isolation.

PubMed

Ares, Manuel

2012-09-01

In this bacterial RNA isolation protocol, an "RNA-protective" treatment is followed by lysozyme digestion of the peptidoglycan component of the cell wall. EDTA promotes the loss of the outer membrane of Gram-negative bacteria and allows the lysozyme better access to the peptidoglycan. Cells begin to lyse during digestion in hypotonic lysozyme buffer and lysis is completed by sodium dodecyl sulfate (SDS) and hot phenol:chloroform:isoamyl alcohol (PCA) extraction. SDS and hot phenol disrupt membranes, denature protein (including RNase), and strip proteins from RNA. The separation of the organic phase from the aqueous phase is achieved using Phase Lock Gel, an inert material with a density intermediate between the organic and aqueous samples. The sample is split into three phases: from bottom to top, these are phenol and chloroform (organic phase), the inert gel with the interface material, and the aqueous phase with the RNA. The gel acts as a physical barrier between the sample and the organic phase plus interface. Following organic extraction, the RNA is concentrated by ethanol precipitation.

Actinide and lanthanide separation process (ALSEP)

DOEpatents

Guelis, Artem V.

2013-01-15

The process of the invention is the separation of minor actinides from lanthanides in a fluid mixture comprising, fission products, lanthanides, minor actinides, rare earth elements, nitric acid and water by addition of an organic chelating aid to the fluid; extracting the fluid with a solvent comprising a first extractant, a second extractant and an organic diluent to form an organic extractant stream and an aqueous raffinate. Scrubbing the organic stream with a dicarboxylic acid and a chelating agent to form a scrubber discharge. The scrubber discharge is stripped with a simple buffering agent and a second chelating agent in the pH range of 2.5 to 6.1 to produce actinide and lanthanide streams and spent organic diluents. The first extractant is selected from bis(2-ethylhexyl)hydrogen phosphate (HDEHP) and mono(2-ethylhexyl)2-ethylhexyl phosphonate (HEH(EHP)) and the second extractant is selected from N,N,N,N-tetra-2-ethylhexyl diglycol amide (TEHDGA) and N,N,N',N'-tetraoctyl-3-oxapentanediamide (TODGA).

Comparison between different interdental stripping methods and evaluation of abrasive strips: SEM analysis.

PubMed

Grippaudo, Cristina; Cancellieri, Daniela; Grecolini, Maria E; Deli, Roberto

2010-01-01

The aim of this study was to evaluate the morphological effects and the surface irregularities produced by different methods of mechanical stripping (abrasive strips and burs) and chemical stripping (37% orthophosphoric acid) and the surface changes following the finishing procedures (polishing strips) or the subsequent application of sealants, in order to establish the right stripping method that can guarantee the smoothest surface. We have also analysed the level of wear on the different abrasive strips employed, according to their structure. 160 proximal surfaces of 80 sound molar teeth extracted for orthodontic and periodontal reasons, were divided into: 1 control group with non-treated enamel proximal surfaces and 5 different groups according to the stripping method used, were observed with scanning electron microscopy (SEM). Each one of the 5 treated groups was also divided into 3 different subgroups according to the finishing procedures or the subsequent application of sealants. The finishing stage following the manual reduction proves to be fundamental in reducing the number and depth of grooves created by the stripping. After the air rotor stripping method, the use of sealants is advised in order to obtain a smoother surface. The analysis of the combinations of mechanical and chemical stripping showed unsatisfactory results. Concerning the wear of the strips, we have highlighted a different abrasion degree for the different types of strips analysed with SEM. The enamel damages are limited only if the finishing procedure is applied, independently of the type of abrasive strip employed. It would be advisable, though clinically seldom possible, the use of sealants after the air rotor stripping technique. Copyright © 2010 Società Italiana di Ortodonzia SIDO. Published by Elsevier Srl. All rights reserved.

Effects of climate and water balance across grasslands of varying C3 and C4 grass cover

USGS Publications Warehouse

Witwicki, Dana L.; Munson, Seth M.; Thoma, David P.

2016-01-01

Climate change in grassland ecosystems may lead to divergent shifts in the abundance and distribution of C3 and C4 grasses. Many studies relate mean climate conditions over relatively long time periods to plant cover, but there is still much uncertainty about how the balance of C3and C4 species will be affected by climate at a finer temporal scale than season (individual events to months). We monitored cover at five grassland sites with co-dominant C3 and C4 grass species or only dominant C3 grass species for 6 yr in national parks across the Colorado Plateau region to assess the influence of specific months of climate and water balance on changes in grass cover. C4 grass cover increased and decreased to a larger degree than C3 grass cover with extremely dry and wet consecutive years, but this response varied by ecological site. Climate and water balance explained 10–49% of the inter-annual variability of cover of C3 and C4 grasses at all sites. High precipitation in the spring and in previous year monsoon storms influenced changes in cover of C4 grasses, with measures of water balance in the same months explaining additional variability. C3 grasses in grasslands where they were dominant were influenced primarily by longer periods of climate, while C3 grasses in grasslands where they were co-dominant with C4 grasses were influenced little by climate anomalies at either short or long periods of time. Our results suggest that future changes in spring and summer climate and water balance are likely to affect cover of both C3 and C4 grasses, but cover of C4 grasses may be affected more strongly, and the degree of change will depend on soils and topography where they are growing and the timing of the growing season.

Coherent Microwave Scattering Model of Marsh Grass

NASA Astrophysics Data System (ADS)

Duan, Xueyang; Jones, Cathleen E.

2017-12-01

In this work, we developed an electromagnetic scattering model to analyze radar scattering from tall-grass-covered lands such as wetlands and marshes. The model adopts the generalized iterative extended boundary condition method (GIEBCM) algorithm, previously developed for buried cylindrical media such as vegetation roots, to simulate the scattering from the grass layer. The major challenge of applying GIEBCM to tall grass is the extremely time-consuming iteration among the large number of short subcylinders building up the grass. To overcome this issue, we extended the GIEBCM to multilevel GIEBCM, or M-GIEBCM, in which we first use GIEBCM to calculate a T matrix (transition matrix) database of "straws" with various lengths, thicknesses, orientations, curvatures, and dielectric properties; we then construct the grass with a group of straws from the database and apply GIEBCM again to calculate the T matrix of the overall grass scene. The grass T matrix is transferred to S matrix (scattering matrix) and combined with the ground S matrix, which is computed using the stabilized extended boundary condition method, to obtain the total scattering. In this article, we will demonstrate the capability of the model by simulating scattering from scenes with different grass densities, different grass structures, different grass water contents, and different ground moisture contents. This model will help with radar experiment design and image interpretation for marshland and wetland observations.

7 CFR 201.51a - Special procedures for purity analysis.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Percent of single units of each kind Chewings fescue Red fescue Orchard-grass Crested wheat-grassb Pubes-cent wheat-grass Intermediate wheat-grass Tall wheat-grass c Western wheat-grassc Smooth brome 50 or...

7 CFR 201.51a - Special procedures for purity analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Percent of single units of each kind Chewings fescue Red fescue Orchard-grass Crested wheat-grassb Pubes-cent wheat-grass Intermediate wheat-grass Tall wheat-grass c Western wheat-grassc Smooth brome 50 or...

UV induced visual cues in grasses

PubMed Central

Baby, Sabulal; Johnson, Anil John; Govindan, Balaji; Lukose, Sujith; Gopakumar, Bhaskaran; Koshy, Konnath Chacko

2013-01-01

Grasses are traditionally considered as wind pollinated, however, field observations confirmed frequent insect visits to grass flowers, suggesting insect pollination. Fruit and seed predators inflict heavy losses to cereals and millets during their growth, maturation and storage. The actual factors guiding insects and predators to grass flowers, fruits and seeds are not clear. Here, we report attractive blue fluorescence emissions on grass floral parts such as glumes, lemma, palea, lodicules, staminal filaments, pollens and fruits in ultraviolet (UV) 366 nm, whereas the stigmatic portions were not blue, but red fluorescent. We characterized the blue fluorescent constituent in grass reproductive structures as ferulic acid (FA). Fluorescence spectra of blue-emitting grass floral, seed extracts and isolated FA on excitation at 366 nm showed their emissions at 420–460 nm. We propose these FA-based blue fluorescence emissions in grass reproductive structures as visual cues that attract pollinators, predators and even pests towards them. PMID:24061408

Research on screening of suitable forage grasses in coastal saline - alkaline soil

NASA Astrophysics Data System (ADS)

Yue, Xiaoyu; Han, Xin; Song, Qianhong; Yang, Xu; Zhou, Qingyun

2017-11-01

The screening of salt-tolerant plants can provide suitable tree species for the afforestation of coastal salinity and maintain biodiversity and ecological stability. The research was based on the study of seven grasses, such as high fescue, the bermuda grass, the thyme, the rye grass, the precocious grass, the third leaf, and the red three leaves. Each pasture was planted in three different kinds of soil, such as salt alkali soil, salt alkali soil + ecological bag and non-saline alkali soil. The effect of salt alkali soil on germinating time, germination rate and grass growth was analyzed. The effects of ecological bag on soil salt and the growth and germination of grass was also analyzed in order to provide the reference basis for the widespread and systematic selection of salt-tolerant plants, with the grass being selected for the suitable ecological bag.

[Mechanisms of grass in slope erosion control in Loess sandy soil region of Northwest China].

PubMed

Zhao, Chun-Hong; Gao, Jian-En; Xu, Zhen

2013-01-01

By adopting the method of simulated precipitation and from the viewpoint of slope hydrodynamics, in combining with the analysis of soil resistance to erosion, a quantitative study was made on the mechanisms of grass in controlling the slope erosion in the cross area of wind-water erosion in Loess Plateau of Northwest China under different combinations of rainfall intensity and slope gradient, aimed to provide basis to reveal the mechanisms of vegetation in controlling soil erosion and to select appropriate vegetation for the soil and water conservation in Loess Plateau. The grass Astragalus adsurgens with the coverage about 40% could effectively control the slope erosion. This grass had an efficiency of more than 70% in reducing sediment, and the grass root had a greater effect than grass canopy. On bare slope and on the slopes with the grass plant or only the grass root playing effect, there existed a functional relation between the flow velocity on the slopes and the rainfall intensity and slope gradient (V = DJ(0.33 i 0.5), where V is flow velocity, D is the comprehensive coefficient which varies with different underlying surfaces, i is rainfall intensity, and J is slope gradient). Both the grass root and the grass canopy could markedly decrease the flow velocity on the slopes, and increase the slope resistance, but the effect of grass root in decreasing flow velocity was greater while the effect in increasing resistance was smaller than that of grass canopy. The effect of grass root in increasing slope resistance was mainly achieved by increasing the sediment grain resistance, while the effect of canopy was mainly achieved by increasing the slope form resistance and wave resistance. The evaluation of the soil resistance to erosion by using a conceptual model of sediment generation by overland flow indicated that the critical shear stress value of bare slope and of the slopes with the grass plant or only the grass root playing effect was 0.533, 1.672 and 0.925 Pa, respectively.

Guidelines for the application of removeable rumble strips

DOT National Transportation Integrated Search

2006-08-01

This work was initiated to assess the viability of removable rumble strips as replacements for asphalt rumble strips, particularly in short term highway work zones. The two rumble strips tested were the Orange Rumble Strip from Advanced Traffic Marki...

Microplasma generator and methods therefor

DOEpatents

Hopwood, Jeffrey A

2015-04-14

A low-temperature, atmospheric-pressure microplasma generator comprises at least one strip of metal on a dielectric substrate. A first end of the strip is connected to a ground plane and the second end of the strip is adjacent to a grounded electrode, with a gap being defined between the second end of the strip and the grounded electrode. High frequency power is supplied to the strip. The frequency is selected so that the length of the strip is an odd integer multiple of 1/4 of the wavelength traveling on the strip. A microplasma forms in the gap between the second end of the strip and the grounded electrode due to electric fields in that region. A microplasma generator array comprises a plurality of strongly-coupled resonant strips in close proximity to one another. At least one of the strips has an input for high-frequency electrical power. The remaining strips resonate due to coupling from the at least one powered strip. The array can provide a continuous line or ring of plasma. The microplasma generator can be used to alter the surface of a substrate, such as by adding material (deposition), removal of material (etching), or modifying surface chemistry.

Catchment systems science and management: from evidence to resilient landscapes

NASA Astrophysics Data System (ADS)

Quinn, Paul

2014-05-01

There is an urgent need to reassess both the scientific understanding and the policy making approaches taken to manage flooding, water scarcity and pollution in intensively utilised catchments. Many European catchments have been heavily modified and natural systems have largely disappeared. However, working with natural processes must still be at the core of any future management strategy. Many catchments have greatly reduced infiltration rates and buffering capacity and this process needs to be reversed. An interventionist and holistic approach to managing water quantity and quality at the catchment scale is urgently required through the active manipulation of natural flow processes. Both quantitative (field experiments and modelling) and qualitative evidence (local knowledge) is required to demonstrate that catchment have become 'unhealthy'. For example, dense networks of low cost instrumentation could provide this multiscale evidence and, coupled with stakeholder knowledge, build a comprehensive understanding of whole system function. Proactive Catchment System Management is an interventionist approach to altering the catchment scale runoff regime through the manipulation of landscape scale hydrological flow pathways. Many of the changes to hydrological processes cannot be detected at the catchment scale as the primary causes of flooding and pollution. Evidence shows it is the land cover and the soil that are paramount to any change. Local evidence shows us that intense agricultural practices reduce the infiltration capacity through soil degradation. The intrinsic buffering capacity has also been lost across the landscape. The emerging hydrological process is one in which the whole system responds too quickly (driven by near surface and overland flow processes). The bulk of the soil matrix is bypassed during storm events and there is little or no buffering capacity in the riparian areas or in headwater catchments. The prospect of lower intensity farming rates is highly unlikely owing to a growing world population and future climates may be driven by more intense rainfall. Together these will increase runoff rates further, generating more erosion, water pollution and floods. A reduction in recharge to the deeper soil and aquifers also increases the chance of droughts as the natural groundwater reservoirs are not replenished. Hence the urgent need to put back the infiltration and buffering capacity for whole catchments. A strategic plan for where, what and how we grow crops and rear animals within catchments is the first step. Example case studies will be presented that provide evidence that intense farming activities can be offset by the creation of soft engineered wetlands, runoff attenuation ponds, buffer strips and high infiltration zones. A fresh look at how our catchments work and an assessment of what is a healthy food and water dynamic for that system is reviewed. Through gathering local evidence of problems and solutions we can demonstrate how healthy catchments should function for the long term.

Evaluation of six candidate DNA barcode loci for identification of five important invasive grasses in eastern Australia

PubMed Central

Wang, Aisuo; Gopurenko, David; Wu, Hanwen; Lepschi, Brendan

2017-01-01

Invasive grass weeds reduce farm productivity, threaten biodiversity, and increase weed control costs. Identification of invasive grasses from native grasses has generally relied on the morphological examination of grass floral material. DNA barcoding may provide an alternative means to identify co-occurring native and invasive grasses, particularly during early growth stages when floral characters are unavailable for analysis. However, there are no universal loci available for grass barcoding. We herein evaluated the utility of six candidate loci (atpF intron, matK, ndhK-ndhC, psbE—petL, ETS and ITS) for barcode identification of several economically important invasive grass species frequently found among native grasses in eastern Australia. We evaluated these loci in 66 specimens representing five invasive grass species (Chloris gayana, Eragrostis curvula, Hyparrhenia hirta, Nassella neesiana, Nassella trichotoma) and seven native grass species. Our results indicated that, while no single locus can be universally used as a DNA barcode for distinguishing the grass species examined in this study, two plastid loci (atpF and matK) showed good distinguishing power to separate most of the taxa examined, and could be used as a dual locus to distinguish several of the invasive from the native species. Low PCR success rates were evidenced among two nuclear loci (ETS and ITS), and few species were amplified at these loci, however ETS was able to genetically distinguish the two important invasive Nassella species. Multiple loci analyses also suggested that ETS played a crucial role in allowing identification of the two Nassella species in the multiple loci combinations. PMID:28399170

Spectral and spatial variability of undisturbed and disturbed grass under different view and illumination directions

NASA Astrophysics Data System (ADS)

Borel-Donohue, Christoph C.; Shivers, Sarah Wells; Conover, Damon

2017-05-01

It is well known that disturbed grass covered surfaces show variability with view and illumination conditions. A good example is a grass field in a soccer stadium that shows stripes indicating in which direction the grass was mowed. These spatial variations are due to a complex interplay of spectral characteristics of grass blades, density, their length and orientations. Viewing a grass surface from nadir or near horizontal directions results in observing different components. Views from a vertical direction show more variations due to reflections from the randomly oriented grass blades and their shadows. Views from near horizontal show a mixture of reflected and transmitted light from grass blades. An experiment was performed on a mowed grass surface which had paths of simulated heavy foot traffic laid down in different directions. High spatial resolution hyperspectral data cubes were taken by an imaging spectrometer covering the visible through near infrared over a period of time covering several hours. Ground truth grass reflectance spectra with a hand held spectrometer were obtained of undisturbed and disturbed areas. Close range images were taken of selected areas with a hand held camera which were then used to reconstruct the 3D geometry of the grass using structure-from-motion algorithms. Computer graphics rendering using raytracing of reconstructed and procedurally created grass surfaces were used to compute BRDF models. In this paper, we discuss differences between observed and simulated spectral and spatial variability. Based on the measurements and/or simulations, we derive simple spectral index methods to detect spatial disturbances and apply scattering models.

Evaluation of six candidate DNA barcode loci for identification of five important invasive grasses in eastern Australia.

PubMed

Wang, Aisuo; Gopurenko, David; Wu, Hanwen; Lepschi, Brendan

2017-01-01

Invasive grass weeds reduce farm productivity, threaten biodiversity, and increase weed control costs. Identification of invasive grasses from native grasses has generally relied on the morphological examination of grass floral material. DNA barcoding may provide an alternative means to identify co-occurring native and invasive grasses, particularly during early growth stages when floral characters are unavailable for analysis. However, there are no universal loci available for grass barcoding. We herein evaluated the utility of six candidate loci (atpF intron, matK, ndhK-ndhC, psbE-petL, ETS and ITS) for barcode identification of several economically important invasive grass species frequently found among native grasses in eastern Australia. We evaluated these loci in 66 specimens representing five invasive grass species (Chloris gayana, Eragrostis curvula, Hyparrhenia hirta, Nassella neesiana, Nassella trichotoma) and seven native grass species. Our results indicated that, while no single locus can be universally used as a DNA barcode for distinguishing the grass species examined in this study, two plastid loci (atpF and matK) showed good distinguishing power to separate most of the taxa examined, and could be used as a dual locus to distinguish several of the invasive from the native species. Low PCR success rates were evidenced among two nuclear loci (ETS and ITS), and few species were amplified at these loci, however ETS was able to genetically distinguish the two important invasive Nassella species. Multiple loci analyses also suggested that ETS played a crucial role in allowing identification of the two Nassella species in the multiple loci combinations.

Characteristics of laminates with delamination control strips

NASA Technical Reports Server (NTRS)

Sun, C. T.; Goering, J. C.; Alper, J. M.; Gause, L. W.

1992-01-01

Tough resin is needed to resist delamination crack propagation. However, modulus often has to be compromised because it is difficult to retain both high modulus and toughness in a matrix material. A potential solution is to use a hybrid system in which tough resin strips are included within a conventional matrix composite. By adjusting the spacing of the tough resin strips, maximum delamination size can be controlled. Experimental results for impact damage and subsequent damage propagation in laminates containing tough resin strips are reported. Plain adhesive strips and fiber-reinforced tough resin composite strips were used in constructing the hybrid laminates. Test results indicated that size of delamination inflicted by impact was confined between the tough resin strips. As a result, significantly increased residual compressive strength was obtained. Impacted laminates containing tough resin strips were also fatigue tested. It was found that these strips reduced the growth of the impact damage area relative to the growth seen in coupons with no tough resin strips. Damage growth from an open hole under tension fatigue was evaluated using both tough resin strips and glass fiber reinforced tough resin strips. Unreinforced tough resin strips retarded delamination growth from the open hole, but did not stop matrix cracks growing in the fiber direction. Fiber reinforced tough resin strips did not contain axial delamination growth from the open hole. However, they did act as crack arresters, stopping the through-the-thickness tension crack originating from the hole.

Fixture for multiple-FCC chemical stripping and plating

NASA Technical Reports Server (NTRS)

Angele, W.; Norton, W. E.

1971-01-01

For chemical stripping, lead tape applied near ends to be stripped protects insulation. Taped ends are submerged half way in stripping solution. For electroplating, both ends of FCC are stripped - top ends for electric contact, others for submersion in electroplating solution.

40 CFR 180.582 - Pyraclostrobin; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 2.5 Gold of pleasure, seed 0.45 Grain, aspirated fractions 2.5 Grape 2.0 Grape, raisin 7.0 Grass, forage 10 Grass, hay 4.5 Grass, seed screenings 27 Grass, straw grown for seed 14 Hare's ear mustard...

40 CFR 180.454 - Nicosulfuron; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... byproducts 0.05 Grass, forage 9.0 Grass, hay 25.0 Horse, fat 0.01 Horse, meat 0.01 Horse, meat byproducts 0... grass, forage 10 12/31/11 Bermuda grass, hay 25 12/31/11 (c) Tolerances with regional registrations...

40 CFR 180.454 - Nicosulfuron; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... byproducts 0.05 Grass, forage 9.0 Grass, hay 25.0 Horse, fat 0.01 Horse, meat 0.01 Horse, meat byproducts 0... grass, forage 10 12/31/11 Bermuda grass, hay 25 12/31/11 (c) Tolerances with regional registrations...

Overlap in nitrogen sources and redistribution of nitrogen between trees and grasses in a semi-arid savanna.

PubMed

Priyadarshini, K V R; Prins, Herbert H T; de Bie, Steven; Heitkönig, Ignas M A; Woodborne, Stephan; Gort, Gerrit; Kirkman, Kevin; Fry, Brian; de Kroon, Hans

2014-04-01

A key question in savanna ecology is how trees and grasses coexist under N limitation. We used N stable isotopes and N content to study N source partitioning across seasons from trees and associated grasses in a semi-arid savanna. We also used (15)N tracer additions to investigate possible redistribution of N by trees to grasses. Foliar stable N isotope ratio (δ(15)N) values were consistent with trees and grasses using mycorrhiza-supplied N in all seasons except in the wet season when they switched to microbially fixed N. The dependence of trees and grasses on mineralized soil N seemed highly unlikely based on seasonal variation in mineralization rates in the Kruger Park region. Remarkably, foliar δ(15)N values were similar for all three tree species differing in the potential for N fixation through nodulation. The tracer experiment showed that N was redistributed by trees to understory grasses in all seasons. Our results suggest that the redistribution of N from trees to grasses and uptake of N was independent of water redistribution. Although there is overlap of N sources between trees and grasses, dependence on biological sources of N coupled with redistribution of subsoil N by trees may contribute to the coexistence of trees and grasses in semi-arid savannas.

Experiment to evaluate feasibility of utilizing Skylab-EREP remote sensing data for tectonic analysis of the Bighorn Mountains region, Wyoming-Montana

NASA Technical Reports Server (NTRS)

Hoppin, R. A. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Excellent imagery has been obtained from SL-3 along track 5 across the Bighorn Mountains and track 19 across the northern Black Hills. The red band is by far the best of the four black and white films of S-190A. Excellent detail is visible of topography, structure, resistant lithologies, and culture with good resolution obtainable at high magnification (30X). The infrared bands do not have as good resolution and are grainy at high magnification. They are of use as a complement to the red band particularly for relief enhancement in areas of heavy green grass and forest cover. S-190B high definition black and white is comparable to the red band (S-190A) in detail. Its main advantage is larger initial scale and slightly better resolution. High resolution color transparencies along track 19 allow detailed delineation of cultivated land and strip mining. A group of folds northwest of Billings stand out clearly. Light colored units in northwestern Black Hills and in the badlands can be mapped in great detail.

Variation in Soil Microbial Community Structure Associated with Different Legume Species Is Greater than that Associated with Different Grass Species

PubMed Central

Zhou, Yang; Zhu, Honghui; Fu, Shenglei; Yao, Qing

2017-01-01

Plants are the essential factors shaping soil microbial community (SMC) structure. When most studies focus on the difference in the SMC structure associated different plant species, the variation in the SMC structure associated with phylogenetically close species is less investigated. Legume (Fabaceae) and grass (Poaceae) are functionally important plant groups; however, their influences on the SMC structure are seldom compared, and the variation in the SMC structure among legume or grass species is largely unknown. In this study, we grew three legume species vs. three grass species in mesocosms, and monitored the soil chemical property, quantified the abundance of bacteria and fungi. The SMC structure was also characterized using PCR-DGGE and Miseq sequencing. Results showed that legume and grass differentially affected soil pH, dissolved organic C, total N content, and available P content, and that legume enriched fungi more greatly than grass. Both DGGE profiling and Miseq-sequencing indicated that the bacterial diversity associated with legume was higher than that associated with grass. When legume increased the abundance of Verrucomicrobia, grass decreased it, and furthermore, linear discriminant analysis identified some group-specific microbial taxa as potential biomarkers of legume or grass. These data suggest that legume and grass differentially select for the SMC. More importantly, clustering analysis based on both DGGE profiling and Miseq-sequencing demonstrated that the variation in the SMC structure associated with three legume species was greater than that associated with three grass species. PMID:28620371

Analyzing rasters, vectors and time series using new Python interfaces in GRASS GIS 7

NASA Astrophysics Data System (ADS)

Petras, Vaclav; Petrasova, Anna; Chemin, Yann; Zambelli, Pietro; Landa, Martin; Gebbert, Sören; Neteler, Markus; Löwe, Peter

2015-04-01

GRASS GIS 7 is a free and open source GIS software developed and used by many scientists (Neteler et al., 2012). While some users of GRASS GIS prefer its graphical user interface, significant part of the scientific community takes advantage of various scripting and programing interfaces offered by GRASS GIS to develop new models and algorithms. Here we will present different interfaces added to GRASS GIS 7 and available in Python, a popular programming language and environment in geosciences. These Python interfaces are designed to satisfy the needs of scientists and programmers under various circumstances. PyGRASS (Zambelli et al., 2013) is a new object-oriented interface to GRASS GIS modules and libraries. The GRASS GIS libraries are implemented in C to ensure maximum performance and the PyGRASS interface provides an intuitive, pythonic access to their functionality. GRASS GIS Python scripting library is another way of accessing GRASS GIS modules. It combines the simplicity of Bash and the efficiency of the Python syntax. When full access to all low-level and advanced functions and structures from GRASS GIS library is required, Python programmers can use an interface based on the Python ctypes package. Ctypes interface provides complete, direct access to all functionality as it would be available to C programmers. GRASS GIS provides specialized Python library for managing and analyzing spatio-temporal data (Gebbert and Pebesma, 2014). The temporal library introduces space time datasets representing time series of raster, 3D raster or vector maps and allows users to combine various spatio-temporal operations including queries, aggregation, sampling or the analysis of spatio-temporal topology. We will also discuss the advantages of implementing scientific algorithm as a GRASS GIS module and we will show how to write such module in Python. To facilitate the development of the module, GRASS GIS provides a Python library for testing (Petras and Gebbert, 2014) which helps researchers to ensure the robustness of the algorithm, correctness of the results in edge cases as well as the detection of changes in results due to new development. For all modules GRASS GIS automatically creates standardized command line and graphical user interfaces and documentation. Finally, we will show how GRASS GIS can be used together with powerful Python tools such as the NumPy package and the IPython Notebook. References: Gebbert, S., Pebesma, E., 2014. A temporal GIS for field based environmental modeling. Environmental Modelling & Software 53, 1-12. Neteler, M., Bowman, M.H., Landa, M. and Metz, M., 2012. GRASS GIS: a multi-purpose Open Source GIS. Environmental Modelling & Software 31: 124-130. Petras, V., Gebbert, S., 2014. Testing framework for GRASS GIS: ensuring reproducibility of scientific geospatial computing. Poster presented at: AGU Fall Meeting, December 15-19, 2014, San Francisco, USA. Zambelli, P., Gebbert, S., Ciolli, M., 2013. Pygrass: An Object Oriented Python Application Programming Interface (API) for Geographic Resources Analysis Support System (GRASS) Geographic Information System (GIS). ISPRS International Journal of Geo-Information 2, 201-219.

Blue wild-rye grass competition increases the effect of ozone on ponderosa pine seedlings.

PubMed

Andersen, C P; Hogsett, W E; Plocher, M; Rodecap, K; Lee, E H

2001-03-01

Individual ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedlings were grown in mesocosms with three densities of blue wild-rye grass (Elymus glaucus Buckl.) (equivalent to 0, 32 or 88 plants m-2) to determine if the presence of a natural competitor alters the response of ponderosa pine seedlings to ozone. After 3 years of ozone exposure, grass presence reduced total ponderosa pine dry mass by nearly 50%, whereas ozone alone had no significant effect on ponderosa pine growth. The combination of ozone and grass further reduced needle, stem and branch dry mass significantly below that induced by grass competition alone. Root:shoot ratios increased in response to the combined grass and ozone treatments. Grass competition significantly reduced soluble sugar concentrations in all ponderosa pine tissue components examined. Starch concentrations were highly variable but did not differ significantly between treatments. Ozone significantly reduced soluble sugar concentrations in fine roots and stems. In the absence of grass, ozone-treated seedlings tended to have higher tissue N concentrations than controls. In the presence of grass, ozone-treated seedlings had lower N concentrations than controls, resulting in a significant interaction between these two stresses in 1- and 2-year-old needles. Needle C:N ratios decreased in response to grass competition, as a result of increased N concentration and no change in C concentration. The opposite response was observed in ozone-treated seedlings as a result of decreased N concentrations, indicating that ozone-treated seedlings were unable to take up or retain as much nitrogen when grown in the presence of grass. We conclude that ponderosa pine seedlings are more susceptible to ozone when grown in competition with blue wild-rye grass.

ironPhone: Mobile device-coupled point-of-care diagnostics for assessment of iron status by quantification of serum ferritin.

PubMed

Srinivasan, Balaji; O'Dell, Dakota; Finkelstein, Julia L; Lee, Seoho; Erickson, David; Mehta, Saurabh

2018-01-15

Iron deficiency (ID) is an urgent public health problem that has devastating effects on maternal and child health. However, due to poor access and affordability, screening and diagnosis for ID is often limited to proxy hemoglobin measurements alone. Here, we report the development and validation of ironPhone, a mobile-device coupled portable diagnostics for quantification of serum ferritin concentrations, an iron status biomarker, within a few minutes, from a drop of fingerprick blood. The ironPhone diagnostic platform comprises of a smartphone accessory, an app, and a disposable lateral flow immunoassay test strip to quantify serum ferritin. For initial validation in the lab, we optimized and evaluated the performance of ironPhone with known ferritin concentrations in spiked buffer and serum samples. Following lab validation, we performed a human validation by collecting fingerprick whole blood samples from 20 participants to assess iron status using ironPhone and compared the results with the laboratory standard IMMULITE 2000 analyzer. Findings from the ironPhone for the buffer and spiked serum samples provided a calibration curve with R 2 values of 0.97 (n=27) and 0.93 (n=12), respectively. On comparison with the laboratory standard IMMULITE analyzer in whole blood samples, a correlation of 0.92 (P<0.0001) was observed with a sensitivity of over 90% for predicting ID (ferritin<15.0µg/L) via the ironPhone, demonstrating its promise for iron status assessment at the point-of-care. Copyright © 2017 Elsevier B.V. All rights reserved.

Iridium Oxide-reduced Graphene Oxide Nanohybrid Thin Film Modified Screen-printed Electrodes as Disposable Electrochemical Paper Microfluidic pH Sensors.

PubMed

Yang, Jiang; Kwak, Tae-Joon; Zhang, Xiaodong; McClain, Robert; Chang, Woo-Jin; Gunasekaran, Sundaram

2016-11-22

A facile, controllable, inexpensive and green electrochemical synthesis of IrO2-graphene nanohybrid thin films is developed to fabricate an easy-to-use integrated paper microfluidic electrochemical pH sensor for resource-limited settings. Taking advantages from both pH meters and strips, the pH sensing platform is composed of hydrophobic barrier-patterned paper micropad (µPAD) using polydimethylsiloxane (PDMS), screen-printed electrode (SPE) modified with IrO2-graphene films and molded acrylonitrile butadiene styrene (ABS) plastic holder. Repetitive cathodic potential cycling was employed for graphene oxide (GO) reduction which can completely remove electrochemically unstable oxygenated groups and generate a 2D defect-free homogeneous graphene thin film with excellent stability and electronic properties. A uniform and smooth IrO2 film in nanoscale grain size is anodically electrodeposited onto the graphene film, without any observable cracks. The resulting IrO2-RGO electrode showed slightly super-Nernstian responses from pH 2-12 in Britton-Robinson (B-R) buffers with good linearity, small hysteresis, low response time and reproducibility in different buffers, as well as low sensitivities to different interfering ionic species and dissolved oxygen. A simple portable digital pH meter is fabricated, whose signal is measured with a multimeter, using high input-impedance operational amplifier and consumer batteries. The pH values measured with the portable electrochemical paper-microfluidic pH sensors were consistent with those measured using a commercial laboratory pH meter with a glass electrode.

The Dark Side of the Moebius Strip.

ERIC Educational Resources Information Center

Schwarz, Gideon E.

1990-01-01

Discussed are various models proposed for the Moebius strip. Included are a discussion of a smooth flat model and two smooth flat algebraic models, some results concerning the shortest Moebius strip, the Moebius strip of least elastic energy, and some observations on real-world Moebius strips. (KR)

26 CFR 1.1286-2 - Stripped inflation-protected debt instruments.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 26 Internal Revenue 11 2013-04-01 2013-04-01 false Stripped inflation-protected debt instruments... Losses § 1.1286-2 Stripped inflation-protected debt instruments. Stripped inflation-protected debt instruments. If a Treasury Inflation-Protected Security is stripped under the Department of the Treasury's...

26 CFR 1.1286-2 - Stripped inflation-protected debt instruments.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 11 2014-04-01 2014-04-01 false Stripped inflation-protected debt instruments... Losses § 1.1286-2 Stripped inflation-protected debt instruments. Stripped inflation-protected debt instruments. If a Treasury Inflation-Protected Security is stripped under the Department of the Treasury's...

Metamodeling as a tool to size vegetative filter strips for surface runoff pollution control in European watersheds.

NASA Astrophysics Data System (ADS)

Lauvernet, Claire; Muñoz-Carpena, Rafael; Carluer, Nadia

2015-04-01

In Europe, a significant presence of contaminants is found in surface water, partly due to pesticide applications. Vegetative filter strips or buffer zones (VFS), often located along rivers, are a common best management practice (BMP) to reduce non point source pollution of water by reducing surface runoff. However, they need to be adapted to the agro-ecological and climatic conditions, both in terms of position and size, in order to be efficient. The TOPPS-PROWADIS project involves European experts and stakeholders to develop and recommend BMPs to reduce pesticide transfer by drift or runoff in several European countries. In this context, IRSTEA developed a guide accompanying the use of different tools, which allows designing site-specific VFS by simulating their efficiency to limit transfers using the mechanistic model VFSMOD. This method which is very complete assumes that the user provides detailed field knowledge and data, which are not always easily available. The aim of this study is to assist the buffer sizing by using a unique tool with a reduced set of parameters, adapted to the available information from the end-users. In order to fill in the lack of real data in many practical applications, a set of virtual scenarios was selected to encompass a large range of agro-pedo-climatic conditions in Europe, considering both the upslope agricultural field and the VFS characteristics. As a first step first, in this work we present scenarios based on North-West of France climate consisting of different rainfall intensities and durations, hillslope lengths and slopes, humidity conditions, a large set of field rainfall/runoff characteristics for the contributing area, and several shallow water table depths and soil types for the VFS. The sizing method based on the mechanistic model VFSMOD was applied for all these scenarios, and a global sensitivity analysis (GSA) of the VFS optimal length was performed for all the input parameters in order to understand their influence and interactions, and set priorities for data collecting and management. Based on GSA results, we compared several mathematical methods to compute the metamodel, and then validated it on an agricultural watershed with real data in the North-West of France. The analysis procedure allows for a robust and validated metamodel, before extending it on other climatic conditions in order to make the application on a large range of european watersheds possible. The tool will allow comparison of field scenarios, and to validate/improve actual existing placements and VFS sizing.

40 CFR 60.3078 - What definitions must I know?

Code of Federal Regulations, 2010 CFR

2010-07-01

... shavings. Wood waste does not include: (1) Grass, grass clippings, bushes, shrubs, and clippings from bushes and shrubs from residential, commercial/retail, institutional, or industrial sources as part of..., flake board, and oriented strand board). Yard waste means grass, grass clippings, bushes, shrubs, and...

40 CFR 60.2977 - What definitions must I know?

Code of Federal Regulations, 2010 CFR

2010-07-01

... shavings. Wood waste does not include: (1) Grass, grass clippings, bushes, shrubs, and clippings from bushes and shrubs from residential, commercial/retail, institutional, or industrial sources as part of..., flake board, and oriented strand board). Yard waste means grass, grass clippings, bushes, shrubs, and...

40 CFR 180.464 - Dimethenamid; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... removed 0.01 Corn, sweet, stover 0.01 Garlic 0.01 Grass, forage 0.15 Grass, hay 2.5 Grass, seed screenings 0.01 Grass, straw 0.01 Hop, dried cones 0.05 Horseradish 0.01 Leek 0.01 Onion, bulb 0.01 Onion...

7 CFR 1436.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... security interest in personal property when properly filed or recorded. Hay means a grass or legume that has been cut and stored. Commonly used grass mixtures include rye grass, timothy, brome, fescue, coastal Bermuda, orchard grass, and other native species, depending on the region. Forage legumes include...

7 CFR 1436.3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... security interest in personal property when properly filed or recorded. Hay means a grass or legume that has been cut and stored. Commonly used grass mixtures include rye grass, timothy, brome, fescue, coastal Bermuda, orchard grass, and other native species, depending on the region. Forage legumes include...

40 CFR 180.464 - Dimethenamid; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... removed 0.01 Corn, sweet, stover 0.01 Garlic 0.01 Grass, forage 0.15 Grass, hay 2.5 Grass, seed screenings 0.01 Grass, straw 0.01 Hop, dried cones 0.05 Horseradish 0.01 Leek 0.01 Onion, bulb 0.01 Onion...

Best management practices for establishment of salt-tolerant grasses on roadsides : final report.

DOT National Transportation Integrated Search

2017-07-01

Roadsides are a unique growing environment for turf grasses and can be a challenge to establish and maintain. The University of Minnesota turf grass research program has been investigating low-input turf grasses that are better adapted for roadsides ...

Genome sequence analysis of the model grass Brachypodium distachyon: insights into grass genome evolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schulman, Al

2009-08-09

Three subfamilies of grasses, the Erhardtoideae (rice), the Panicoideae (maize, sorghum, sugar cane and millet), and the Pooideae (wheat, barley and cool season forage grasses) provide the basis of human nutrition and are poised to become major sources of renewable energy. Here we describe the complete genome sequence of the wild grass Brachypodium distachyon (Brachypodium), the first member of the Pooideae subfamily to be completely sequenced. Comparison of the Brachypodium, rice and sorghum genomes reveals a precise sequence- based history of genome evolution across a broad diversity of the grass family and identifies nested insertions of whole chromosomes into centromericmore » regions as a predominant mechanism driving chromosome evolution in the grasses. The relatively compact genome of Brachypodium is maintained by a balance of retroelement replication and loss. The complete genome sequence of Brachypodium, coupled to its exceptional promise as a model system for grass research, will support the development of new energy and food crops« less

Microbiological Quality of Panicum maximum Grass Silage with Addition of Lactobacillus sp. as Starter

NASA Astrophysics Data System (ADS)

Sumarsih, S.; Sulistiyanto, B.; Utama, C. S.

2018-02-01

The aim of the research was to evaluate microbiological quality of Panicum maximum grass silage with addition Lactobacillus sp as starter. The completely randomized design was been used on this research with 4 treaments and 3 replications. The treatments were P0 ( Panicum maximum grass silage without addition Lactobacillus sp ), P1 ( Panicum maximum grass silage with 2% addition Lactobacillus sp), P2 (Panicum maximum grass silage with 4% addition Lactobacillus sp) and P3 (Panicum maximum grass silage with 6% addition Lactobacillus sp).The parameters were microbial populations of Panicum maximum grass silage (total lactic acid bacteria, total bacteria, total fungi, and Coliform bacteria. The data obtained were analyzed variance (ANOVA) and further tests performed Duncan’s Multiple Areas. The population of lactic acid bacteria was higher (P<0.05) and the total bacteria, fungi and Coliform were lower (P<0.05) with addition Lactobacillus sp. Microbiological quality of Panicum maximum grass silage with addition Lactobacillus sp was better than no addition Lactobacillus sp.

Heat Shock Proteins in Association with Heat Tolerance in Grasses

PubMed Central

Xu, Yan; Zhan, Chenyang; Huang, Bingru

2011-01-01

The grass family Poaceae includes annual species cultivated as major grain crops and perennial species cultivated as forage or turf grasses. Heat stress is a primary factor limiting growth and productivity of cool-season grass species and is becoming a more significant problem in the context of global warming. Plants have developed various mechanisms in heat-stress adaptation, including changes in protein metabolism such as the induction of heat shock proteins (HSPs). This paper summarizes the structure and function of major HSPs, recent research progress on the association of HSPs with grass tolerance to heat stress, and incorporation of HSPs in heat-tolerant grass breeding. PMID:22084689

Estimation of the Botanical Composition of Clover-Grass Leys from RGB Images Using Data Simulation and Fully Convolutional Neural Networks

PubMed Central

Steen, Kim Arild; Green, Ole; Karstoft, Henrik

2017-01-01

Optimal fertilization of clover-grass fields relies on knowledge of the clover and grass fractions. This study shows how knowledge can be obtained by analyzing images collected in fields automatically. A fully convolutional neural network was trained to create a pixel-wise classification of clover, grass, and weeds in red, green, and blue (RGB) images of clover-grass mixtures. The estimated clover fractions of the dry matter from the images were found to be highly correlated with the real clover fractions of the dry matter, making this a cheap and non-destructive way of monitoring clover-grass fields. The network was trained solely on simulated top-down images of clover-grass fields. This enables the network to distinguish clover, grass, and weed pixels in real images. The use of simulated images for training reduces the manual labor to a few hours, as compared to more than 3000 h when all the real images are annotated for training. The network was tested on images with varied clover/grass ratios and achieved an overall pixel classification accuracy of 83.4%, while estimating the dry matter clover fraction with a standard deviation of 7.8%. PMID:29258215

26 CFR 1.1286-2 - Stripped inflation-indexed debt instruments.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Stripped inflation-indexed debt instruments. 1....1286-2 Stripped inflation-indexed debt instruments. Stripped inflation-indexed debt instruments. If a Treasury Inflation-Indexed Security is stripped under the Department of the Treasury's Separate Trading of...

Isotopic signatures of vegetation change on northern mixed grass prairie

USDA-ARS?s Scientific Manuscript database

National analyses have shown invasion of northern mixed-grass prairie by nonnative grasses such as Kentucky bluegrass (Poa pratensis L.). Invasion of native prairie by nonnative grasses may compromise ecosystem function and limit potential ecosystem services. Recent data from a long-term (100 year) ...

75 FR 66781 - Habitat Conservation Plan for Pacific Gas & Electric Company's Operation, Maintenance, and Minor...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-29

... Dunes evening-primrose E Oenotherawolfii Wolf's evening-primrose -- Orcuttiapilosa Hairy orcutt grass E Orcuttiatenuis Slender orcutt grass T Orcuttiaviscida Sacramento orcutt grass E Packeralayneae Layne's ragwort T... Monterey pine -- Piperiayadonii Yadon's rein orchid E Pleuropogonhooverianus North Coast semaphore grass...

Evaluating the Capability of Grass Swale for the Rainfall Runoff Reduction from an Urban Parking Lot, Seoul, Korea

PubMed Central

Shafique, Muhammad; Kim, Reeho; Kyung-Ho, Kwon

2018-01-01

This field study elaborates the role of grass swale in the management of stormwater in an urban parking lot. Grass swale was constructed by using different vegetations and local soil media in the parking lot of Mapu-gu Seoul, Korea. In this study, rainfall runoff was first retained in soil and the vegetation layers of the grass swale, and then infiltrated rainwater was collected with the help of underground perforated pipe, and passed to an underground storage trench. In this way, grass swale detained a large amount of rainwater for a longer period of time and delayed peak discharge. In this field study, various real storm events were monitored and the research results were analyzed to evaluate the performance of grass swale for managing rainfall runoff in an urban area. From the analysis of field experiments, grass swale showed the significant rainfall runoff retention in different rain events. Grass swale markedly reduced total rainfall runoff volume and peak flow during the small storm events of intensity about 30 mm/h. From the analysis, on average rainfall runoff retention from the grass swale was found around 40 to 75% during the various small rain events. From the results, we can say that grass swale is a stormwater mitigation practice which can help avoid flash flooding problems in urban areas. PMID:29547567

Evaluating the Capability of Grass Swale for the Rainfall Runoff Reduction from an Urban Parking Lot, Seoul, Korea.

PubMed

Shafique, Muhammad; Kim, Reeho; Kyung-Ho, Kwon

2018-03-16

This field study elaborates the role of grass swale in the management of stormwater in an urban parking lot. Grass swale was constructed by using different vegetations and local soil media in the parking lot of Mapu-gu Seoul, Korea. In this study, rainfall runoff was first retained in soil and the vegetation layers of the grass swale, and then infiltrated rainwater was collected with the help of underground perforated pipe, and passed to an underground storage trench. In this way, grass swale detained a large amount of rainwater for a longer period of time and delayed peak discharge. In this field study, various real storm events were monitored and the research results were analyzed to evaluate the performance of grass swale for managing rainfall runoff in an urban area. From the analysis of field experiments, grass swale showed the significant rainfall runoff retention in different rain events. Grass swale markedly reduced total rainfall runoff volume and peak flow during the small storm events of intensity about 30 mm/h. From the analysis, on average rainfall runoff retention from the grass swale was found around 40 to 75% during the various small rain events. From the results, we can say that grass swale is a stormwater mitigation practice which can help avoid flash flooding problems in urban areas.

Bismuth-based electrochemical stripping analysis

DOEpatents

Wang, Joseph

2004-01-27

Method and apparatus for trace metal detection and analysis using bismuth-coated electrodes and electrochemical stripping analysis. Both anodic stripping voltammetry and adsorptive stripping analysis may be employed.

When did C4 Photosynthesis originate: New evidence from δ13C analysis of single grass-pollen grains

NASA Astrophysics Data System (ADS)

Urban, M. A.; Nelson, D. M.; Pearson, A.; Hu, F.

2009-12-01

C4 grasses account for >20% of global primary productivity and dominate tropical, subtropical, and warm-temperate grassland ecosystems. Thus it is vital to understand when and why C4 photosynthesis first evolved in the grass family (Poaceae). However, because of limitations of most proxies, the origin of C4 grasses remains ambiguous. Grass pollen is morphologically indistinct below the family level, making pollen analysis a crude instrument for studying C4-grass evolution. Previous studies have investigated the timing of C4 evolution using molecular tools and δ13C records from n-alkanes, ungulate teeth, and paleosols, but they yield disparate results. Molecular clocks suggest that C4 grasses first evolved between 27 and 36 Ma (million years before present), coincident with the Oligocene decline in pCO2 from >1000 to <500 ppm. In contrast, δ13C-based approaches do not detect the presence of C4 grasses until the middle Miocene, indicating that they were previously uncommon or absent on the landscape. To investigate when C4 photosynthesis first appeared in the grass family, we utilized Single Pollen Isotope Ratio AnaLysis (SPIRAL), a technique that reliably distinguishes C4 from C3 grass pollen via δ13C. We analyzed 837 single grains of grass pollen from eight lacustrine geological samples (~100 grains/sample) from France and Spain spanning the earliest Oligocene to middle Miocene. To distinguish C3/C4 ratios, we used an optimal threshold value of -19.2‰ adjusted for small (~1‰) temporal variations in atmospheric δ13C. Initial results provide unequivocal evidence of C4 grass pollen in all samples (24-57% C4 grass pollen ±9.2% on average) lending further credence to the molecular data, which posits that C4 grasses appeared as early as the Late Eocene, which is a plausible outcome when considering alternate schemes of dating phylogenetic trees. A C4 origin prior to pCO2 reaching its lowest levels of the Cenozoic at the Oligocene/Miocene boundary indicates that ecological or climatic factors played a pivotal role in the evolution of C4 grasses. However, our estimates for the timing of C4 evolution remain imprecise. We do not have SPIRAL data from samples older than ~34 Ma. Future analyzes will include well-dated samples from additional sites as old as the the late Paleocene, when grass pollen first appeared in the fossil record. In addition, we are refining the C3/C4 threshold value using grass pollen from herbarium specimens. New results should help pinpoint the timing of C4 evolution. Comparison of the timing of C4 evolution with independent pCO2, paleoclimate and paleoecological records will be used to assess the factor(s) that drove the evolution and eventual dominance of C4 grasses.

Development and validation of a 5-day-ahead hay fever forecast for patients with grass-pollen-induced allergic rhinitis

NASA Astrophysics Data System (ADS)

de Weger, Letty A.; Beerthuizen, Thijs; Hiemstra, Pieter S.; Sont, Jacob K.

2014-08-01

One-third of the Dutch population suffers from allergic rhinitis, including hay fever. In this study, a 5-day-ahead hay fever forecast was developed and validated for grass pollen allergic patients in the Netherlands. Using multiple regression analysis, a two-step pollen and hay fever symptom prediction model was developed using actual and forecasted weather parameters, grass pollen data and patient symptom diaries. Therefore, 80 patients with a grass pollen allergy rated the severity of their hay fever symptoms during the grass pollen season in 2007 and 2008. First, a grass pollen forecast model was developed using the following predictors: (1) daily means of grass pollen counts of the previous 10 years; (2) grass pollen counts of the previous 2-week period of the current year; and (3) maximum, minimum and mean temperature ( R 2 = 0.76). The second modeling step concerned the forecasting of hay fever symptom severity and included the following predictors: (1) forecasted grass pollen counts; (2) day number of the year; (3) moving average of the grass pollen counts of the previous 2 week-periods; and (4) maximum and mean temperatures ( R 2 = 0.81). Since the daily hay fever forecast is reported in three categories (low-, medium- and high symptom risk), we assessed the agreement between the observed and the 1- to 5-day-ahead predicted risk categories by kappa, which ranged from 65 % to 77 %. These results indicate that a model based on forecasted temperature and grass pollen counts performs well in predicting symptoms of hay fever up to 5 days ahead.

Development and validation of a 5-day-ahead hay fever forecast for patients with grass-pollen-induced allergic rhinitis.

PubMed

de Weger, Letty A; Beerthuizen, Thijs; Hiemstra, Pieter S; Sont, Jacob K

2014-08-01

One-third of the Dutch population suffers from allergic rhinitis, including hay fever. In this study, a 5-day-ahead hay fever forecast was developed and validated for grass pollen allergic patients in the Netherlands. Using multiple regression analysis, a two-step pollen and hay fever symptom prediction model was developed using actual and forecasted weather parameters, grass pollen data and patient symptom diaries. Therefore, 80 patients with a grass pollen allergy rated the severity of their hay fever symptoms during the grass pollen season in 2007 and 2008. First, a grass pollen forecast model was developed using the following predictors: (1) daily means of grass pollen counts of the previous 10 years; (2) grass pollen counts of the previous 2-week period of the current year; and (3) maximum, minimum and mean temperature (R (2)=0.76). The second modeling step concerned the forecasting of hay fever symptom severity and included the following predictors: (1) forecasted grass pollen counts; (2) day number of the year; (3) moving average of the grass pollen counts of the previous 2 week-periods; and (4) maximum and mean temperatures (R (2)=0.81). Since the daily hay fever forecast is reported in three categories (low-, medium- and high symptom risk), we assessed the agreement between the observed and the 1- to 5-day-ahead predicted risk categories by kappa, which ranged from 65 % to 77 %. These results indicate that a model based on forecasted temperature and grass pollen counts performs well in predicting symptoms of hay fever up to 5 days ahead.

A grass-fire cycle eliminates an obligate-seeding tree in a tropical savanna.

PubMed

Bowman, David M J S; MacDermott, Harry J; Nichols, Scott C; Murphy, Brett P

2014-11-01

A grass-fire cycle in Australian tropical savannas has been postulated as driving the regional decline of the obligate-seeding conifer Callitris intratropica and other fire-sensitive components of the regional flora and fauna, due to proliferation of flammable native grasses. We tested the hypothesis that a high-biomass invasive savanna grass drives a positive feedback process where intense fires destroy fire-sensitive trees, and the reduction in canopy cover facilitates further invasion by grass. We undertook an observational and experimental study using, as a model system, a plantation of C. intratropica that has been invaded by an African grass, gamba (Andropogon gayanus) in the Northern Territory, Australia. We found that high grass biomass was associated with reduced canopy cover and restriction of foliage to the upper canopy of surviving stems, and mortality of adult trees was very high (>50%) even in areas with low fuel loads (1 t·ha(-1)). Experimental fires, with fuel loads >10 t·ha(-1), typical of the grass-invasion front, caused significant mortality due to complete crown scorch. Lower fuel loads cause reduced canopy cover through defoliation of the lower canopy. These results help explain how increases in grass biomass are coupled with the decline of C. intratropica throughout northern Australia by causing a switch from litter and sparse perennial grass fuels, and hence low-intensity surface fires, to heavy annual grass fuel loads that sustain fires that burn into the midstorey. This study demonstrates that changes in fuel type can alter fire regimes with substantial knock-on effects on the biota.

Modeled hydraulic redistribution in tree-grass, CAM-grass, and tree-CAM associations: the implications of crassulacean acid metabolism (CAM).

PubMed

Yu, Kailiang; Foster, Adrianna

2016-04-01

Past studies have largely focused on hydraulic redistribution (HR) in trees, shrubs, and grasses, and recognized its role in interspecies interactions. HR in plants that conduct crassulacean acid metabolism (CAM), however, remains poorly investigated, as does the effect of HR on transpiration in different vegetation associations (i.e., tree-grass, CAM-grass, and tree-CAM associations). We have developed a mechanistic model to investigate the net direction and magnitude of HR at the patch scale for tree-grass, CAM-grass, and tree-CAM associations at the growing season to yearly timescale. The modeling results show that deep-rooted CAM plants in CAM-grass associations could perform hydraulic lift at a higher rate than trees in tree-grass associations in a relatively wet environment, as explained by a significant increase in grass transpiration rate in the shallow soil layer, balancing a lower transpiration rate by CAM plants. By comparison, trees in tree-CAM associations may perform hydraulic descent at a higher rate than those in tree-grass associations in a dry environment. Model simulations also show that hydraulic lift increases the transpiration of shallow-rooted plants, while hydraulic descent increases that of deep-rooted plants. CAM plants transpire during the night and thus perform HR during the day. Based on these model simulations, we suggest that the ability of CAM plants to perform HR at a higher rate may have different effects on the surrounding plant community than those of plants with C3 or C4 photosynthetic pathways (i.e., diurnal transpiration).

Affinity of hemoglobin for the cytoplasmic fragment of human erythrocyte membrane band 3. Equilibrium measurements at physiological pH using matrix-bound proteins: the effects of ionic strength, deoxygenation and of 2,3-diphosphoglycerate.

PubMed

Chétrite, G; Cassoly, R

1985-10-05

The cytoplasmic fragment of band 3 protein isolated from the human erythrocyte membrane was linked to a CNBr-activated Sepharose matrix in an attempt to measure, in batch experiments, its equilibrium binding constant with oxy- and deoxyhemoglobin at physiological pH and ionic strength values and in the presence or the absence of 2,3-diphosphoglycerate. All the experiments were done at pH 7.2, and equilibrium constants were computed on the basis of one hemoglobin tetramer bound per monomer of fragment. In 10 mM-phosphate buffer, a dissociation constant KD = 2 X 10(-4)M was measured for oxyhemoglobin and was shown to increase to 8 X 10(-4)M in the presence of 50 mM-NaCl. Association could not be demonstrated at higher salt concentrations. Diphosphoglycerate-stripped deoxyhemoglobin was shown to associate more strongly with the cytoplasmic fragment of band 3. In 10 mM-bis-Tris (pH 7.2) and in the presence of 120 mM-NaCl, a dissociation constant KD = 4 X 10(-4)M was measured. Upon addition of increasing amounts of 2,3-diphosphoglycerate, the complex formed between deoxyhemoglobin and the cytoplasmic fragment of band 3 was dissociated. On the reasonable assumption that the hemoglobin binding site present on band 3 fragment was not modified upon linking the protein to the Sepharose matrix, the results indicated that diphosphoglycerate-stripped deoxyhemoglobin or partially liganded hemoglobin tetramers in the T state could bind band 3 inside the intact human red blood cell.

A fast, low power and low noise charge sensitive amplifier ASIC for a UV imaging single photon detector

NASA Astrophysics Data System (ADS)

Seljak, A.; Cumming, H. S.; Varner, G.; Vallerga, J.; Raffanti, R.; Virta, V.

2017-04-01

NASA has funded, through their Strategic Astrophysics Technology (SAT) program, the development of a cross strip (XS) microchannel plate (MCP) detector with the intention to increase its technology readiness level (TRL), enabling prototyping for future NASA missions. One aspect of the development is to convert the large and high powered laboratory Parallel Cross Strip (PXS) readout electronics into application specific integrated circuits (ASICs) to decrease their mass, volume, and power consumption (all limited resources in space) and to make them more robust to the environments of rocket launch and space. The redesign also foresees to increase the overall readout event rate, and decrease the noise contribution of the readout system. This work presents the design and verification of the first stage for the new readout system, the 16 channel charge sensitive amplifier ASIC, called the CSAv3. The single channel amplifier is composed of a charge sensitive amplifier (pre-amplifier), a pole zero cancellation circuit and a shaping amplifier. An additional output stage buffer allows polarity selection of the output analog signal. The operation of the amplifier is programmable via serial bus. It provides an equivalent noise charge (ENC) of around 600 e^- and a baseline gain of 10 mV/fC. The full scale pulse shaped output signal is confined within 100 ns, without long recovery tails, enabling up to 10 MHz periodic event rates without signal pile up. This ASIC was designed and fabricated in 130 nm, TSMC CMOS 1.2 V technology. In addition, we briefly discuss the construction of the readout system and plans for the future work.

A square-wave adsorptive stripping voltammetric method for the determination of Amaranth, a food additive dye.

PubMed

Alghamdi, Ahmad H

2005-01-01

Square-wave adsorptive stripping voltammetric (AdSV) determinations of trace concentrations of the azo coloring agent Amaranth are described. The analytical methodology used was based on the adsorptive preconcentration of the dye on the hanging mercury drop electrode, followed by initiation of a negative sweep. In a pH 10 carbonate supporting electrolyte, Amaranth gave a well-defined and sensitive AdSV peak at -518 mV. The electroanalytical determination of this azo dye was found to be optimal in carbonate buffer (pH 10) under the following experimental conditions: accumulation time, 120 s; accumulation potential, 0.0 V; scan rate, 600 mV/s; pulse amplitude, 90 mV; and frequency, 50 Hz. Under these optimized conditions the AdSV peak current was proportional over the concentration range 1 x 10(-8)-1.1 x 10(-7) mol/L (r = 0.999) with a detection limit of 1.7 x 10(-9) mol/L (1.03 ppb). This analytical approach possessed enhanced sensitivity, compared with conventional liquid chromatography or spectrophotometry and it was simple and fast. The precision of the method, expressed as the relative standard deviation, was 0.23%, whereas the accuracy, expressed as the mean recovery, was 104%. Possible interferences by several substances usually present as food additive azo dyes (E110, E102), gelatin, natural and artificial sweeteners, preservatives, and antioxidants were also investigated. The developed electroanalyticals method was applied to the determination of Amaranth in soft drink samples, and the results were compared with those obtained by a reference spectrophotometric method. Statistical analysis (paired t-test) of these data showed that the results of the 2 methods compared favorably.

Optimizing the Electron-Withdrawing Character on Benzenesulfonyl Moiety Attached to a Glyco-Conjugate to Impart Sensitive and Selective Sensing of Cyanide in HEPES Buffer and on Cellulose Paper and Silica Gel Strips.

PubMed

Areti, Sivaiah; Bandaru, Sateesh; Yarramala, Deepthi S; Rao, Chebrolu Pulla

2015-12-15

Dansyl-derivatized, triazole-linked, glucopyranosyl conjugates, (5F)LOH, (2F)LOH, (1F)LOH, and (0F)LOH were synthesized and characterized. While the (5F)LOH acts as a molecular probe for CN(-), (2F)LOH, (1F)LOH, and (0F)LOH acts as control molecules. The reactivity of CN(-) toward (5F)LOH has been elicited through the changes observed in NMR, ESI MS, emission, and absorption spectroscopy. The conjugate (5F)LOH releases a fluorescent product upon reaction by CN(-) in aqueous acetonitrile medium by exhibiting an ∼125-fold fluorescence enhancement even in the presence of other anions. Fluorescence switch-on behavior has been clearly demonstrated on the basis of the nucleophilic substitution reaction of CN(-) on (5F)LOH. A minimum detection limit of (2.3 ± 0.3) × 10(-7) M (6 ± 1 ppb) was shown by (5F)LOH for CN(-) in solution. All the other anions studied showed no change in the fluorescence emission. The utility of (5F)LOH has been demonstrated by showing its reactivity toward CN(-) on a thin layer of silica gel as well as on Whatman No. 1 cellulose filter paper strips. The role of glucose moiety and the penta-fluorobenzenesulfonyl reactive center present in (5F)LOH in the selectivity of CN(-) over other anions has been demonstrated by fluorescence, absorption and thermodynamics study. Similar studies carried out with the control molecules showed no selectivity for CN(-). The mechanistic aspects of the reactivity of CN(-) toward (5F)LOH were supported by DFT computational study.

Quantification of lead and cadmium in poultry and bird game meat by square-wave anodic-stripping voltammetry.

PubMed

Trevisani, M; Cecchini, M; Taffetani, L; Vercellotti, L; Rosmini, R

2011-02-01

A square-wave anodic-stripping voltammetric method for the analysis of lead and cadmium in chicken muscle and liver was developed and validated, and the results of a monitoring study relative to chicken and pigeon meat are reported. The voltammetric method allows the analysis of lead and cadmium at the same time in samples after acid digestion. The use of perchloric acid for digestion and of acetate buffer in the supporting electrolyte are suitable to reduce matrix interferences and obtain limits of quantification which were below 10 ng g⁻¹ for meat and liver samples. The regression between the analytical signal and the concentration of the target analytes in spiked samples and Certified Reference Materials proved to be linear within the 10-100 ng g⁻¹ range for meat and within the 50-500 ng g⁻¹ range for liver. The analytical method was verified using available Certified Reference Materials BCR-184 (cattle meat) and BCR-185R (cattle liver) as well as with spiked chicken samples. Precision (i.e. repeatability and intermediate precision) and accuracy (percentage recovery and bias) were of the order of 0.3-4.5% for both lead and cadmium The level of lead in muscle was in the range between 6.4 and 59.8 ng g⁻¹ in chickens and between 7.9 and 63.6 ng g⁻¹ in farmed pigeons, whereas it was between 8.0 and 84.4 ng g⁻¹ in chicken liver. The cadmium concentration was 0.4-10.4 ng g⁻¹ in chicken muscle, 10.4-90.6 ng g⁻¹ in chicken liver and 2.2-8.0 ng g⁻¹ in farmed pigeons.

78 FR 49149 - Endangered and Threatened Wildlife and Plants; Determination of Endangered Status for Sphaeralcea...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-13

... to further declines through stochastic wildfire events, spread of the nonnative grasses, and climate... descriptions predict the annual production (pounds per acre) of plant groups (grass/grass-like, forbs, shrub... than fewer numbers of shrubs and perennial grasses. Therefore, although an ecological site description...

75 FR 17716 - Notice of Receipt of Requests to Voluntarily Cancel Certain Pesticide Registrations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

...- Clean Extra isopropylammonium Strength Systemic Weed + Grass 000070-00284 Rigo Neat'n Glyphosate- Clean isopropylammonium Concentrate Systemic Weed and Grass 000100-00530 Methidathion Methidathion Technical 000100 AR-03... Weed and Grass Killer 000192-00177 Dexol Weed Diquat dibromide &Grass Killer 000192-00178 Dexol Weed...

26 CFR 56.4911-6 - Records of lobbying and grass roots expenditures.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Records of lobbying and grass roots... lobbying and grass roots expenditures. (a) Records of lobbying expenditures. An electing public charity... organization must keep a record include the following: (1) Expenditures for grass roots lobbying, as described...

26 CFR 56.4911-6 - Records of lobbying and grass roots expenditures.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 17 2011-04-01 2011-04-01 false Records of lobbying and grass roots... lobbying and grass roots expenditures. (a) Records of lobbying expenditures. An electing public charity... organization must keep a record include the following: (1) Expenditures for grass roots lobbying, as described...

75 FR 4279 - Pendimethalin; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-27

...-dimethyl-2,6- dinitrobenzenamine, in or on grass forage, fodder, and hay crop group 17, forage; grass forage, fodder, and hay crop group 17, hay; and grass forage, fodder, and hay crop group 17, straw. BASF...-dinitrobenzyl alcohol, expressed as the stoichiometric equivalent of pendimethalin, in or on grass forage...

Roll Casting of Aluminum Alloy Clad Strip

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakamura, R.; Tsuge, H.; Haga, T.

2011-01-17

Casting of aluminum alloy three layers of clad strip was tried using the two sets of twin roll casters, and effects of the casting parameters on the cladding conditions were investigated. One twin roll caster was mounted on the other twin roll caster. Base strip was 8079 aluminum alloy and overlay strips were 6022 aluminum alloy. Effects of roll-load of upper and lower casters and melt temperature of the lower caster were investigated. When the roll-load of the upper and lower caster was large enough, the overlay strip could be solidified and be connected. The overlay strip could be connectedmore » when the melt of the overlay strip cast by the lower caster was low enough. Sound three layers of clad strip could be cast by proper conditions.« less

A test for measuring gustatory function.

PubMed

Smutzer, Gregory; Lam, Si; Hastings, Lloyd; Desai, Hetvi; Abarintos, Ray A; Sobel, Marc; Sayed, Nabil

2008-08-01

The purpose of this study was to determine the usefulness of edible taste strips for measuring human gustatory function. The physical properties of edible taste strips were examined to determine their potential for delivering threshold and suprathreshold amounts of taste stimuli to the oral cavity. Taste strips were then assayed by fluorescence to analyze the uniformity and distribution of bitter tastant in the strips. Finally, taste recognition thresholds for sweet taste were examined to determine whether or not taste strips could detect recognition thresholds that were equal to or better than those obtained from aqueous tests. Edible strips were prepared from pullulan-hydroxypropyl methylcellulose solutions that were dried to a thin film. The maximal amount of a tastant that could be incorporated in a 2.54 cm2 taste strip was identified by including representative taste stimuli for each class of tastant (sweet, sour, salty, bitter, and umami) during strip formation. Distribution of the bitter tastant quinine hydrochloride in taste strips was assayed by fluorescence emission spectroscopy. The efficacy of taste strips for evaluating human gustatory function was examined by using a single series ascending method of limits protocol. Sucrose taste recognition threshold data from edible strips was then compared with results that were obtained from a standard "sip and spit" recognition threshold test. Edible films that formed from a pullulan-hydroxypropyl methylcellulose polymer mixture can be used to prepare clear, thin strips that have essentially no background taste and leave no physical presence after release of tastant. Edible taste strips could uniformly incorporate up to 5% of their composition as tastant. Taste recognition thresholds for sweet taste were over one order of magnitude lower with edible taste strips when compared with an aqueous taste test. Edible taste strips are a highly sensitive method for examining taste recognition thresholds in humans. This new means of presenting taste stimuli should have widespread applications for examining human taste function in the laboratory, in the clinic, or at remote locations.

[Association of phytoplasma with Bermuda grass white-leaf disease].

PubMed

Tan, Weijun; Chen, Yong; Zhang, Wu; Han, Chengchou; Tan, Zhiyuan; Zhang, Juming

2008-10-01

Bermuda grass white leaf is an important disease on Bermuda grass all over the world. The aim of this research is to identify the pathogen which leads to Bermuda grass white leaf occurring on the Chinese mainland. PCR amplification technique, sequence analysis and Southern hybridization were used. A 1.3 kb fragment was amplified by PCR phytoplasma universal primers and total DNA sample extracted from ill Bermuda grass as the amplified template. Sequence analysis of the amplified fragment indicated it clustered into Candidatus Phytoplasm Cynodontis. Southern hybridization analysis showed differential cingulums. The pathogen of Bermuda grass white leaf on the Chinese mainland contains phytoplasma, which provides a scientific basis for further identification, prevention and control of the disease.

Lateral flow strip assay

DOEpatents

Miles, Robin R [Danville, CA; Benett, William J [Livermore, CA; Coleman, Matthew A [Oakland, CA; Pearson, Francesca S [Livermore, CA; Nasarabadi, Shanavaz L [Livermore, CA

2011-03-08

A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.

Biotechnological application of sustainable biogas production through dry anaerobic digestion of Napier grass.

PubMed

Dussadee, Natthawud; Ramaraj, Rameshprabu; Cheunbarn, Tapana

2017-05-01

Napier grass (Pennisetum purpureum), represents an interesting substrate for biogas production. The research project evaluated biogas potential production from dry anaerobic digestion of Napier grass using batch experiment. To enhance the biogas production from ensiled Napier grass, thermal and alkaline pre-treatments were performed in batch mode. Alkali hydrolysis of Napier grass was performed prior to batch dry anaerobic digestion at three different mild concentrations of sodium hydroxide (NaOH). The study results confirmed that NaOH pretreated sample produced high yield of biogas than untreated (raw) and hot water pretreated samples. Napier grass was used as the mono-substrate. The biogas composition of carbon dioxide (30.10%), methane (63.50%) and 5 ppm of H 2 S was estimated from the biogas. Therefore, fast-growing, high-yielding and organic matter-enriched of Napier grass was promising energy crop for biogas production.

Efficacy of adhesive strips to reduce postoperative periorbital edema and ecchymosis following rhinoplasty

PubMed

Tatar, Sedat; Bulam, Mehmet Hakan; Özmen, Selahattin

2018-02-23

Background/aim: Periorbital edema and ecchymosis may develop following rhinoplasty. The aim of this study was to assess the efficacy of adhesive strip application on the upper and lower eyelids to reduce postoperative edema and ecchymosis following rhinoplasty. Materials and methods: The eyelids of one side were randomly selected, and an adhesive strip of standard size and number was applied at the end of the operation. The strips were removed at postoperative day 3; photos of the eyes were taken at days 3 and 7. Edema and ecchymosis were graded on a scale from 1 to 4. The ecchymosis areas on the lower and upper eyelids were measured and compared in square centimeters. Results: The mean ecchymosis area of the lower eyelid on the side of the adhesive strip and on the side without the strip was 1.63 cm2 and 3.32 cm2 in the early period, respectively. It was 1.15 cm2 on the upper eyelid on the side of the adhesive strip, and 1.87 cm2 on the side without the strip. It was 0.224 cm2 on the side of the adhesive strip, and 0.498 cm2 on the side without the adhesive strip in the late period. Conclusion: Applying adhesive strips reduces periorbital edema and ecchymosis.

High resolution energy-sensitive digital X-ray

DOEpatents

Nygren, David R.

1995-01-01

An apparatus and method for detecting an x-ray and for determining the depth of penetration of an x-ray into a semiconductor strip detector. In one embodiment, a semiconductor strip detector formed of semiconductor material is disposed in an edge-on orientation towards an x-ray source such that x-rays From the x-ray source are incident upon and substantially perpendicular to the front edge of the semiconductor strip detector. The semiconductor strip detector is formed of a plurality of segments. The segments are coupled together in a collinear arrangement such that the semiconductor strip detector has a length great enough such that substantially all of the x-rays incident on the front edge of the semiconductor strip detector interact with the semiconductor material which forms the semiconductor strip detector. A plurality of electrodes are connected to the semiconductor strip detect or such that each one of the of semiconductor strip detector segments has at least one of the of electrodes coupled thereto. A signal processor is also coupled to each one of the electrodes. The present detector detects an interaction within the semiconductor strip detector, between an x-ray and the semiconductor material, and also indicates the depth of penetration of the x-ray into the semiconductor strip detector at the time of the interaction.

High resolution energy-sensitive digital X-ray

DOEpatents

Nygren, D.R.

1995-07-18

An apparatus and method for detecting an x-ray and for determining the depth of penetration of an x-ray into a semiconductor strip detector. In one embodiment, a semiconductor strip detector formed of semiconductor material is disposed in an edge-on orientation towards an x-ray source such that x-rays from the x-ray source are incident upon and substantially perpendicular to the front edge of the semiconductor strip detector. The semiconductor strip detector is formed of a plurality of segments. The segments are coupled together in a collinear arrangement such that the semiconductor strip detector has a length great enough such that substantially all of the x-rays incident on the front edge of the semiconductor strip detector interact with the semiconductor material which forms the semiconductor strip detector. A plurality of electrodes are connected to the semiconductor strip detector such that each one of the semiconductor strip detector segments has at least one of the of electrodes coupled thereto. A signal processor is also coupled to each one of the electrodes. The present detector detects an interaction within the semiconductor strip detector, between an x-ray and the semiconductor material, and also indicates the depth of penetration of the x-ray into the semiconductor strip detector at the time of the interaction. 5 figs.

7 CFR 1437.310 - Sea grass and sea oats.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 10 2012-01-01 2012-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value loss...

7 CFR 1437.310 - Sea grass and sea oats.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 10 2013-01-01 2013-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value loss...