The use of sequential extraction to evaluate the remediation potential of heavy metals from contaminated harbour sediment

NASA Astrophysics Data System (ADS)

Nystrøm, G. M.; Ottosen, L. M.; Villumsen, A.

2003-05-01

In this work sequential extraction is performed with harbour sediment in order to evaluate the electrodialytic remediation potential for harbour sediments. Sequential extraction was performed on a sample of Norwegian harbour sediment; with the original sediment and after the sediment was treated with acid. The results from the sequential extraction show that 75% Zn and Pb and about 50% Cu are found in the most mobile phases in the original sediment and more than 90% Zn and Pb and 75% Cu are found in the most mobile phase in the sediment treated with acid. Electrodialytic remediation experiments were made. The method uses a low direct current as cleaning agent, removing the heavy metals towards the anode and cathode according to the charge of the heavy metals in the electric field. The electrodialytic experiments show that up to 50% Cu, 85% Zn and 60% Pb can be removed after 20 days. Thus, there is still a potential for a higher removal, with some changes in the experimental set-up and longer remediation time. The experiments show that thc use of sequential extraction can be used to predict the electrodialytic remediation potential for harbour sediments.

Evaluating specificity of sequential extraction for chemical forms of lead in artificially-contaminated and field-contaminated soils.

PubMed

Tai, Yiping; McBride, Murray B; Li, Zhian

2013-03-30

In the present study, we evaluated a commonly employed modified Bureau Communautaire de Référence (BCR test) 3-step sequential extraction procedure for its ability to distinguish forms of solid-phase Pb in soils with different sources and histories of contamination. When the modified BCR test was applied to mineral soils spiked with three forms of Pb (pyromorphite, hydrocerussite and nitrate salt), the added Pb was highly susceptible to dissolution in the operationally-defined "reducible" or "oxide" fraction regardless of form. When three different materials (mineral soil, organic soil and goethite) were spiked with soluble Pb nitrate, the BCR sequential extraction profiles revealed that soil organic matter was capable of retaining Pb in more stable and acid-resistant forms than silicate clay minerals or goethite. However, the BCR sequential extraction for field-collected soils with known and different sources of Pb contamination was not sufficiently discriminatory in the dissolution of soil Pb phases to allow soil Pb forms to be "fingerprinted" by this method. It is concluded that standard sequential extraction procedures are probably not very useful in predicting lability and bioavailability of Pb in contaminated soils. Copyright © 2013 Elsevier B.V. All rights reserved.

Selenium speciation in seleniferous agricultural soils under different cropping systems using sequential extraction and X-ray absorption spectroscopy.

PubMed

Qin, Hai-Bo; Zhu, Jian-Ming; Lin, Zhi-Qing; Xu, Wen-Po; Tan, De-Can; Zheng, Li-Rong; Takahashi, Yoshio

2017-06-01

Selenium (Se) speciation in soil is critically important for understanding the solubility, mobility, bioavailability, and toxicity of Se in the environment. In this study, Se fractionation and chemical speciation in agricultural soils from seleniferous areas were investigated using the elaborate sequential extraction and X-ray absorption near-edge structure (XANES) spectroscopy. The speciation results quantified by XANES technique generally agreed with those obtained by sequential extraction, and the combination of both approaches can reliably characterize Se speciation in soils. Results showed that dominant organic Se (56-81% of the total Se) and lesser Se(IV) (19-44%) were observed in seleniferous agricultural soils. A significant decrease in the proportion of organic Se to the total Se was found in different types of soil, i.e., paddy soil (81%) > uncultivated soil (69-73%) > upland soil (56-63%), while that of Se(IV) presented an inverse tendency. This suggests that Se speciation in agricultural soils can be significantly influenced by different cropping systems. Organic Se in seleniferous agricultural soils was probably derived from plant litter, which provides a significant insight for phytoremediation in Se-laden ecosystems and biofortification in Se-deficient areas. Furthermore, elevated organic Se in soils could result in higher Se accumulation in crops and further potential chronic Se toxicity to local residents in seleniferous areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimizing Standard Sequential Extraction Protocol With Lake And Ocean Sediments

EPA Science Inventory

The environmental mobility/availability behavior of radionuclides in soils and sediments depends on their speciation. Experiments have been carried out to develop a simple but robust radionuclide sequential extraction method for identification of radionuclide partitioning in sed...

Collaborative Filtering Based on Sequential Extraction of User-Item Clusters

NASA Astrophysics Data System (ADS)

Honda, Katsuhiro; Notsu, Akira; Ichihashi, Hidetomo

Collaborative filtering is a computational realization of “word-of-mouth” in network community, in which the items prefered by “neighbors” are recommended. This paper proposes a new item-selection model for extracting user-item clusters from rectangular relation matrices, in which mutual relations between users and items are denoted in an alternative process of “liking or not”. A technique for sequential co-cluster extraction from rectangular relational data is given by combining the structural balancing-based user-item clustering method with sequential fuzzy cluster extraction appraoch. Then, the tecunique is applied to the collaborative filtering problem, in which some items may be shared by several user clusters.

Sequential cloud-point extraction for toxicological screening analysis of medicaments in human plasma by high pressure liquid chromatography with diode array detector.

PubMed

Madej, Katarzyna; Persona, Karolina; Wandas, Monika; Gomółka, Ewa

2013-10-18

A complex extraction system with the use of cloud-point extraction technique (CPE) was developed for sequential isolation of basic and acidic/neutral medicaments from human plasma/serum, screened by HPLC/DAD method. Eight model drugs (paracetamol, promazine, chlorpromazine, amitriptyline, salicyclic acid, opipramol, alprazolam and carbamazepine) were chosen for the study of optimal CPE conditions. The CPE technique consists in partition of an aqueous sample with addition of a surfactant into two phases: micelle-rich phase with the isolated compounds and water phase containing a surfactant below the critical micellar concentration, mainly under influence of temperature change. The proposed extraction system consists of two chief steps: isolation of basic compounds (from pH 12) and then isolation of acidic/neutral compounds (from pH 6) using surfactant Triton X-114 as the extraction medium. Extraction recovery varied from 25.2 to 107.9% with intra-day and inter-day precision (RSD %) ranged 0.88-1087 and 5.32-17.96, respectively. The limits of detection for the studied medicaments at λ 254nm corresponded to therapeutic or low toxic plasma concentration levels. Usefulness of the proposed CPE-HPLC/DAD method for toxicological drug screening was tested via its application to analysis of two serum samples taken from patients suspected of drug overdosing. Published by Elsevier B.V.

Back-extraction of trace elements from organometallic-halide extracts for determination by flameless atomic absorption spectrometry

USGS Publications Warehouse

Clark, J.R.; Viets, J.G.

1981-01-01

The Methyl isobutyl ketone-Amine synerGistic Iodkte Complex (MAGIC) extraction system offers the advantage that a large number of trace elements can be rapidly determined with a single sample preparation procedure. However, many of the elements extracted by the MAGIC system form volatile organometallic halide salts when the organic extract is heated in the graphite furnace. High concentrations of some elements such as Cu and Zn extracted by the system from anomalous geological samples produce serious interferences when certain other elements are determined by flameless atomic absorption. Stripping systems have been developed using solutions of HNO3, H2SO4, and CH3COOH individually or combined with H2O2 in order to circumvent these problems. With these systems most of the elements in the organic extract can be sequentially stripped into an aqueous phase. Organometallic volatilization and the most serious interelement interferences, therefore, can be eliminated by stripping with various combinations of reagents in a series of steps.

Separation of chemical groups from bio-oil aqueous phase via sequential organic solvent extraction

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

Ren, Shoujie; Ye, Philip; Borole, Abhijeet P

Bio-oil aqueous phase contains a considerable amount of furans, alcohols, ketones, aldehydes and phenolics besides the major components of organic acids and anhydrosugars. The complexity of bio-oil aqueous phase limits its efficient utilization. To improve the efficiency of bio-oil biorefinery, this study focused on the separation of chemical groups from bio-oil aqueous phase via sequential organic solvent extractions. Due to their high recoverability and low solubility in water, four solvents (hexane, petroleum ether, chloroform, and ethyl acetate) with different polarities were evaluated, and the optimum process conditions for chemical extraction were determined. Chloroform had high extraction efficiency for furans, phenolics,more » and ketones. In addition to these chemical groups, ethyl acetate had high extraction efficiency for organic acids. The sequential extraction by using chloroform followed by ethyl acetate rendered that 62.2 wt.% of original furans, ketones, alcohols, and phenolics were extracted to chloroform, over 62 wt.% acetic acid was extracted to ethyl acetate, resulting in a high concentration of levoglucosan (~53.0 wt.%) in the final aqueous phase. Chemicals separated via the sequential extraction could be used as feedstocks in biorefinery using processes such as catalytic upgrading of furans and phenolics to hydrocarbons, fermentation of levoglucosan to produce alcohols and diols, and hydrogen production from organic acids via microbial electrolysis.« less

Separation of chemical groups from bio-oil aqueous phase via sequential organic solvent extraction

DOE PAGES

Ren, Shoujie; Ye, Philip; Borole, Abhijeet P

2017-01-05

Bio-oil aqueous phase contains a considerable amount of furans, alcohols, ketones, aldehydes and phenolics besides the major components of organic acids and anhydrosugars. The complexity of bio-oil aqueous phase limits its efficient utilization. To improve the efficiency of bio-oil biorefinery, this study focused on the separation of chemical groups from bio-oil aqueous phase via sequential organic solvent extractions. Due to their high recoverability and low solubility in water, four solvents (hexane, petroleum ether, chloroform, and ethyl acetate) with different polarities were evaluated, and the optimum process conditions for chemical extraction were determined. Chloroform had high extraction efficiency for furans, phenolics,more » and ketones. In addition to these chemical groups, ethyl acetate had high extraction efficiency for organic acids. The sequential extraction by using chloroform followed by ethyl acetate rendered that 62.2 wt.% of original furans, ketones, alcohols, and phenolics were extracted to chloroform, over 62 wt.% acetic acid was extracted to ethyl acetate, resulting in a high concentration of levoglucosan (~53.0 wt.%) in the final aqueous phase. Chemicals separated via the sequential extraction could be used as feedstocks in biorefinery using processes such as catalytic upgrading of furans and phenolics to hydrocarbons, fermentation of levoglucosan to produce alcohols and diols, and hydrogen production from organic acids via microbial electrolysis.« less

Metal fractionation in olive oil and urban sewage sludges using the three-stage BCR sequential extraction method and microwave single extractions.

PubMed

Pérez Cid, B; Fernández Alborés, A; Fernández Gómez, E; Faliqé López, E

2001-08-01

The conventional three-stage BCR sequential extraction method was employed for the fractionation of heavy metals in sewage sludge samples from an urban wastewater treatment plant and from an olive oil factory. The results obtained for Cu, Cr, Ni, Pb and Zn in these samples were compared with those attained by a simplified extraction procedure based on microwave single extractions and using the same reagents as employed in each individual BCR fraction. The microwave operating conditions in the single extractions (heating time and power) were optimized for all the metals studied in order to achieve an extraction efficiency similar to that of the conventional BCR procedure. The measurement of metals in the extracts was carried out by flame atomic absorption spectrometry. The results obtained in the first and third fractions by the proposed procedure were, for all metals, in good agreement with those obtained using the BCR sequential method. Although in the reducible fraction the extraction efficiency of the accelerated procedure was inferior to that of the conventional method, the overall metals leached by both microwave single and sequential extractions were basically the same (recoveries between 90.09 and 103.7%), except for Zn in urban sewage sludges where an extraction efficiency of 87% was achieved. Chemometric analysis showed a good correlation between the results given by the two extraction methodologies compared. The application of the proposed approach to a certified reference material (CRM-601) also provided satisfactory results in the first and third fractions, as it was observed for the sludge samples analysed.

ASSESSMENT OF A SEQUENTIAL EXTRACTION PROCEDURE FOR PERTURBED LEAD-CONTAMINATED SAMPLES WITH AND WITHOUT PHOSPHOROUS AMENDMENTS

EPA Science Inventory

Sequential extraction procedures are used to determine the solid-phase association in which elements of interest exist in soil and sediment matrices. Foundational work by Tessier et al. (1) has found widespread acceptance and has worked tolerably as an operational definition for...

Surface characterization of cottonseed meal products by SEM, SEM-EDS, XRD and XPS analysis

USDA-ARS?s Scientific Manuscript database

The utilization of cottonseed meal as a valuable industrial feedstock needs to be exploited. We have recently produced water-washed cottonseed meal, total cottonseed protein, sequentially extracted water- and alkali-soluble proteins, and two residues after the total and sequential protein extraction...

The utilization of modified BCR three-step sequential extraction procedure for the fractionation of Cd, Cr, Cu, Ni, Pb and Zn in soil reference materials of different origins.

PubMed

Zemberyová, Mária; Barteková, Jana; Hagarová, Ingrid

2006-12-15

A modified three-step sequential extraction procedure for the fractionation of heavy metals, proposed by the Commission of the European Communities Bureau of Reference (BCR) has been applied to the Slovak reference materials of soils (soil orthic luvisols, soil rendzina and soil eutric cambisol), which represent pedologically different types of soils in Slovakia. Analyses were carried out by flame or electrothermal atomic absorption spectrometry (FAAS or ETAAS). The fractions extracted were: exchangeable (extraction step 1), reducible-iron/manganese oxides (extraction step 2), oxidizable-organic matter and sulfides (extraction step 3). The sum of the element contents in the three fractions plus aqua-regia extractable content of the residue was compared to the aqua-regia extractable content of the elements in the origin soils. The accuracy obtained by comparing the determined contents of the elements with certified values, using BCR CRM 701, certified for the extractable contents (mass fractions) of Cd, Cr, Cu, Ni, Pb and Zn in sediment following a modified BCR-three step sequential extraction procedure, was found to be satisfactory.

Sequential extractions of selenium soils from Stewart Lake: total selenium and speciation measurements with ICP-MS detection.

PubMed

Ponce de León, Claudia A; DeNicola, Katie; Montes Bayón, Maria; Caruso, Joseph A

2003-06-01

Different techniques have been employed in order to evaluate the most efficient procedure for the extraction of selenium from soil as required for speciation. Selenium contaminated sediments from Stewart Lake Wetland, California were used. A strong acid mineralization of the samples gives quantitative total selenium, which is then used to estimate recoveries for the milder extraction methods. The different extraction methodologies involve the sequential use of water, buffer (phosphate, pH 7) and either acid solution (e.g. HNO3 or HCl) or basic solutions (e.g. ammonium acetate, NaOH or TMAH). Pyrophosphate extraction was also evaluated and showed that selenium was not associated with humic acids. The extractants were subsequently analyzed by size exclusion chromatography (SEC) with UV (254 and 400 nm) and on-line ICP-MS detection; anion exchange chromatography, and ion-pair reversed phase chromatography with ICP-MS detection. For sequential extractions the extraction efficiencies showed that the basic extractions were more efficient than the acidic. The difference between the acidic and the basic extraction efficiency is carried to the sulfite extraction, suggesting that whatever is not extracted by the acid is subsequently extracted by the sulfite. The species identified with the different chromatographies were selenate, selenite, elemental selenium and some organic selenium.

Sulfur K-edge XANES and acid volatile sulfide analyses of changes in chemical speciation of S and Fe during sequential extraction of trace metals in anoxic sludge from biogas reactors.

PubMed

Shakeri Yekta, Sepehr; Gustavsson, Jenny; Svensson, Bo H; Skyllberg, Ulf

2012-01-30

The effect of sequential extraction of trace metals on sulfur (S) speciation in anoxic sludge samples from two lab-scale biogas reactors augmented with Fe was investigated. Analyses of sulfur K-edge X-ray absorption near edge structure (S XANES) spectroscopy and acid volatile sulfide (AVS) were conducted on the residues from each step of the sequential extraction. The S speciation in sludge samples after AVS analysis was also determined by S XANES. Sulfur was mainly present as FeS (≈ 60% of total S) and reduced organic S (≈ 30% of total S), such as organic sulfide and thiol groups, in the anoxic solid phase. Sulfur XANES and AVS analyses showed that during first step of the extraction procedure (the removal of exchangeable cations), a part of the FeS fraction corresponding to 20% of total S was transformed to zero-valent S, whereas Fe was not released into the solution during this transformation. After the last extraction step (organic/sulfide fraction) a secondary Fe phase was formed. The change in chemical speciation of S and Fe occurring during sequential extraction procedure suggests indirect effects on trace metals associated to the FeS fraction that may lead to incorrect results. Furthermore, by S XANES it was verified that the AVS analysis effectively removed the FeS fraction. The present results identified critical limitations for the application of sequential extraction for trace metal speciation analysis outside the framework for which the methods were developed. Copyright © 2011 Elsevier B.V. All rights reserved.

Phosphorus Speciation of Sequential Extracts of Organic Amendments using NMR Spectroscopy

NASA Astrophysics Data System (ADS)

Akinremi, O.

2009-04-01

O.O. 1Akinremi Babasola Ajiboye and Donald N. Flaten 1Department of Soil Science, University of Manitoba, Winnipeg, R3T 2NT, Canada We carried out this study in order to determine the forms of phosphorus in various organic amendments using state-of-the art spectroscopic technique. Anaerobically digested biosolids (BIO), hog (HOG), dairy (DAIRY), beef (BEEF) and poultry (POULTRY) manures were subjected to sequential extraction. The extracts were analyzed by solution 31P nuclear magnetic resonance (NMR) spectroscopy. Most of the total P analysed by inductively coupled plasma-optical emission spectroscopy (ICP-OES) in the sequential extracts of organic amendments were orthophosphate, except POULTRY, which was dominated by organic P. The labile P fraction in all the organic amendments, excluding POULTRY, was mainly orthophosphate P from readily soluble calcium and some aluminum phosphates. In the poultry litter, however, Ca phytate was the main P species controlling P solubility. Such knowledge of the differences in the chemical forms of phosphorus in organic amendments are essential for proper management of these amendments for agro-environmental purposes Key words: organic amendments, solution NMR, sequential fractionation, labile phosphorus

A new perspective of using sequential extraction: To predict the deficiency of trace elements during anaerobic digestion.

PubMed

Cai, Yafan; Wang, Jungang; Zhao, Yubin; Zhao, Xiaoling; Zheng, Zehui; Wen, Boting; Cui, Zongjun; Wang, Xiaofen

2018-09-01

Trace elements were commonly used as additives to facilitate anaerobic digestion. However, their addition is often blind because of the complexity of reaction conditions, which has impeded their widespread application. Therefore, this study was conducted to evaluate deficiencies in trace elements during anaerobic digestion by establishing relationships between changes in trace element bioavailability (the degree to which elements are available for interaction with biological systems) and digestion performance. To accomplish this, two batch experiments were conducted. In the first, sequential extraction was used to detect changes in trace element fractions and then to evaluate trace element bioavailability in the whole digestion cycle. In the second batch experiment, trace elements (Co, Fe, Cu, Zn, Mn, Mo and Se) were added to the reaction system at three concentrations (low, medium and high) and their effects were monitored. The results showed that sequential extraction was a suitable method for assessment of the bioavailability of trace elements (appropriate coefficient of variation and recovery rate). The results revealed that Se had the highest (44.2%-70.9%) bioavailability, while Fe had the lowest (1.7%-3.0%). A lack of trace elements was not directly related to their absolute bioavailability, but was instead associated with changes in their bioavailability throughout the digestion cycle. Trace elements were insufficient when their bioavailability was steady or increased over the digestion cycle. These results indicate that changes in trace element bioavailability during the digestion cycle can be used to predict their deficiency. Copyright © 2018 Elsevier Ltd. All rights reserved.

Near real-time adverse drug reaction surveillance within population-based health networks: methodology considerations for data accrual.

PubMed

Avery, Taliser R; Kulldorff, Martin; Vilk, Yury; Li, Lingling; Cheetham, T Craig; Dublin, Sascha; Davis, Robert L; Liu, Liyan; Herrinton, Lisa; Brown, Jeffrey S

2013-05-01

This study describes practical considerations for implementation of near real-time medical product safety surveillance in a distributed health data network. We conducted pilot active safety surveillance comparing generic divalproex sodium to historical branded product at four health plans from April to October 2009. Outcomes reported are all-cause emergency room visits and fractures. One retrospective data extract was completed (January 2002-June 2008), followed by seven prospective monthly extracts (January 2008-November 2009). To evaluate delays in claims processing, we used three analytic approaches: near real-time sequential analysis, sequential analysis with 1.5 month delay, and nonsequential (using final retrospective data). Sequential analyses used the maximized sequential probability ratio test. Procedural and logistical barriers to active surveillance were documented. We identified 6586 new users of generic divalproex sodium and 43,960 new users of the branded product. Quality control methods identified 16 extract errors, which were corrected. Near real-time extracts captured 87.5% of emergency room visits and 50.0% of fractures, which improved to 98.3% and 68.7% respectively with 1.5 month delay. We did not identify signals for either outcome regardless of extract timeframe, and slight differences in the test statistic and relative risk estimates were found. Near real-time sequential safety surveillance is feasible, but several barriers warrant attention. Data quality review of each data extract was necessary. Although signal detection was not affected by delay in analysis, when using a historical control group differential accrual between exposure and outcomes may theoretically bias near real-time risk estimates towards the null, causing failure to detect a signal. Copyright © 2013 John Wiley & Sons, Ltd.

Modified sequential extraction for biochar and petroleum coke: Metal release potential and its environmental implications.

PubMed

von Gunten, Konstantin; Alam, Md Samrat; Hubmann, Magdalena; Ok, Yong Sik; Konhauser, Kurt O; Alessi, Daniel S

2017-07-01

A modified Community Bureau of Reference (CBR) sequential extraction method was tested to assess the composition of untreated pyrogenic carbon (biochar) and oil sands petroleum coke. Wood biochar samples were found to contain lower concentrations of metals, but had higher fractions of easily mobilized alkaline earth and transition metals. Sewage sludge biochar was determined to be less recalcitrant and had higher total metal concentrations, with most of the metals found in the more resilient extraction fractions (oxidizable, residual). Petroleum coke was the most stable material, with a similar metal distribution pattern as the sewage sludge biochar. The applied sequential extraction method represents a suitable technique to recover metals from these materials, and is a valuable tool in understanding the metal retaining and leaching capability of various biochar types and carbonaceous petroleum coke samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sequential segmental terminal lenticular side-cut dissection for safe and effective small-incision lenticule extraction in thin lenticules.

PubMed

Jacob, Soosan; Agarwal, Amar; Mazzotta, Cosimo; Agarwal, Athiya; Raj, John Michael

2017-04-01

Small-incision lenticule extraction may be associated with complications such as partial lenticular dissection, torn lenticule, lenticular adherence to cap, torn cap, and sub-cap epithelial ingrowth, some of which are more likely to occur during low-myopia corrections. We describe sequential segmental terminal lenticular side-cut dissection to facilitate minimally traumatic and smooth lenticular extraction. Anterior lamellar dissection is followed by central posterior lamellar dissection, leaving a thin peripheral rim and avoiding the lenticular side cut. This is followed by sequential segmental dissection of the lenticular side cut in a manner that fixates the lenticule and provides sufficient resistance for smooth and complete dissection of the posterior lamellar cut without undesired movements of the lenticule. The technique is advantageous in thin lenticules, where the risk for complications is high, but can also be used in thick lenticular dissection using wider sweeps to separate the lenticular side cut sequentially. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Binding intensity and metal partitioning in soils affected by mining and smelting activities in Minas Gerais, Brazil.

PubMed

Lopes, G; Costa, E T S; Penido, E S; Sparks, D L; Guilherme, L R G

2015-09-01

Mining and smelting activities are potential sources of heavy metal contamination, which pose a threat to human health and ecological systems. This study investigated single and sequential extractions of Zn, Pb, and Cd in Brazilian soils affected by mining and smelting activities. Soils from a Zn mining area (soils A, B, C, D, E, and the control soil) and a tailing from a smelting area were collected in Minas Gerais state, Brazil. The samples were subjected to single (using Mehlich I solution) and sequential extractions. The risk assessment code (RAC), the redistribution index (U ts ), and the reduced partition index (I R ) have been applied to the sequential extraction data. Zinc and Cd, in soil samples from the mining area, were found mainly associated with carbonate forms. This same pattern did not occur for Pb. Moreover, the Fe-Mn oxides and residual fractions had important contributions for Zn and Pb in those soils. For the tailing, more than 70 % of Zn and Cd were released in the exchangeable fraction, showing a much higher mobility and availability of these metals at this site, which was also supported by results of RAC and I R . These differences in terms of mobility might be due to different chemical forms of the metals in the two sites, which are attributable to natural occurrence as well as ore processing.

Manganese speciation of laboratory-generated welding fumes

PubMed Central

Andrews, Ronnee N.; Keane, Michael; Hanley, Kevin W.; Feng, H. Amy; Ashley, Kevin

2015-01-01

The objective of this laboratory study was to identify and measure manganese (Mn) fractions in chamber-generated welding fumes (WF) and to evaluate and compare the results from a sequential extraction procedure for Mn fractions with that of an acid digestion procedure for measurement of total, elemental Mn. To prepare Mn-containing particulate matter from representative welding processes, a welding system was operated in short circuit gas metal arc welding (GMAW) mode using both stainless steel (SS) and mild carbon steel (MCS) and also with flux cored arc welding (FCAW) and shielded metal arc welding (SMAW) using MCS. Generated WF samples were collected onto polycarbonate filters before homogenization, weighing and storage in scintillation vials. The extraction procedure consisted of four sequential steps to measure various Mn fractions based upon selective solubility: (1) soluble Mn dissolved in 0.01 M ammonium acetate; (2) Mn (0,II) dissolved in 25 % (v/v) acetic acid; (3) Mn (III,IV) dissolved in 0.5% (w/v) hydroxylamine hydrochloride in 25% (v/v) acetic acid; and (4) insoluble Mn extracted with concentrated hydrochloric and nitric acids. After sample treatment, the four fractions were analyzed for Mn by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). WF from GMAW and FCAW showed similar distributions of Mn species, with the largest concentrations of Mn detected in the Mn (0,II) and insoluble Mn fractions. On the other hand, the majority of the Mn content of SMAW fume was detected as Mn (III,IV). Although the concentration of Mn measured from summation of the four sequential steps was statistically significantly different from that measured from the hot block dissolution method for total Mn, the difference is small enough to be of no practical importance for industrial hygiene air samples, and either method may be used for Mn measurement. The sequential extraction method provides valuable information about the oxidation state of Mn in samples and allows for comparison to results from previous work and from total Mn dissolution methods. PMID:26345630

Manganese speciation of laboratory-generated welding fumes.

PubMed

Andrews, Ronnee N; Keane, Michael; Hanley, Kevin W; Feng, H Amy; Ashley, Kevin

The objective of this laboratory study was to identify and measure manganese (Mn) fractions in chamber-generated welding fumes (WF) and to evaluate and compare the results from a sequential extraction procedure for Mn fractions with that of an acid digestion procedure for measurement of total, elemental Mn. To prepare Mn-containing particulate matter from representative welding processes, a welding system was operated in short circuit gas metal arc welding (GMAW) mode using both stainless steel (SS) and mild carbon steel (MCS) and also with flux cored arc welding (FCAW) and shielded metal arc welding (SMAW) using MCS. Generated WF samples were collected onto polycarbonate filters before homogenization, weighing and storage in scintillation vials. The extraction procedure consisted of four sequential steps to measure various Mn fractions based upon selective solubility: (1) soluble Mn dissolved in 0.01 M ammonium acetate; (2) Mn (0,II) dissolved in 25 % (v/v) acetic acid; (3) Mn (III,IV) dissolved in 0.5% (w/v) hydroxylamine hydrochloride in 25% (v/v) acetic acid; and (4) insoluble Mn extracted with concentrated hydrochloric and nitric acids. After sample treatment, the four fractions were analyzed for Mn by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). WF from GMAW and FCAW showed similar distributions of Mn species, with the largest concentrations of Mn detected in the Mn (0,II) and insoluble Mn fractions. On the other hand, the majority of the Mn content of SMAW fume was detected as Mn (III,IV). Although the concentration of Mn measured from summation of the four sequential steps was statistically significantly different from that measured from the hot block dissolution method for total Mn, the difference is small enough to be of no practical importance for industrial hygiene air samples, and either method may be used for Mn measurement. The sequential extraction method provides valuable information about the oxidation state of Mn in samples and allows for comparison to results from previous work and from total Mn dissolution methods.

Testing sequential extraction methods for the analysis of multiple stable isotope systems from a bone sample

NASA Astrophysics Data System (ADS)

Sahlstedt, Elina; Arppe, Laura

2017-04-01

Stable isotope composition of bones, analysed either from the mineral phase (hydroxyapatite) or from the organic phase (mainly collagen) carry important climatological and ecological information and are therefore widely used in paleontological and archaeological research. For the analysis of the stable isotope compositions, both of the phases, hydroxyapatite and collagen, have their more or less well established separation and analytical techniques. Recent development in IRMS and wet chemical extraction methods have facilitated the analysis of very small bone fractions (500 μg or less starting material) for PO43-O isotope composition. However, the uniqueness and (pre-) historical value of each archaeological and paleontological finding lead to preciously little material available for stable isotope analyses, encouraging further development of microanalytical methods for the use of stable isotope analyses. Here we present the first results in developing extraction methods for combining collagen C- and N-isotope analyses to PO43-O-isotope analyses from a single bone sample fraction. We tested sequential extraction starting with dilute acid demineralization and collection of both collagen and PO43-fractions, followed by further purification step by H2O2 (PO43-fraction). First results show that bone sample separates as small as 2 mg may be analysed for their δ15N, δ13C and δ18OPO4 values. The method may be incorporated in detailed investigation of sequentially developing skeletal material such as teeth, potentially allowing for the investigation of interannual variability in climatological/environmental signals or investigation of the early life history of an individual.

Sequential Learning and Recognition of Comprehensive Behavioral Patterns Based on Flow of People

NASA Astrophysics Data System (ADS)

Gibo, Tatsuya; Aoki, Shigeki; Miyamoto, Takao; Iwata, Motoi; Shiozaki, Akira

Recently, surveillance cameras have been set up everywhere, for example, in streets and public places, in order to detect irregular situations. In the existing surveillance systems, as only a handful of surveillance agents watch a large number of images acquired from surveillance cameras, there is a possibility that they may miss important scenes such as accidents or abnormal incidents. Therefore, we propose a method for sequential learning and the recognition of comprehensive behavioral patterns in crowded places. First, we comprehensively extract a flow of people from input images by using optical flow. Second, we extract behavioral patterns on the basis of change-point detection of the flow of people. Finally, in order to recognize an observed behavioral pattern, we draw a comparison between the behavioral pattern and previous behavioral patterns in the database. We verify the effectiveness of our approach by placing a surveillance camera on a campus.

Speciation of mercury in sludge solids: washed sludge

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

Bannochie, C. J.; Lourie, A. P.

2017-10-24

The objective of this applied research task was to study the type and concentration of mercury compounds found within the contaminated Savannah River Site Liquid Waste System (SRS LWS). A method of selective sequential extraction (SSE), developed by Eurofins Frontier Global Sciences1,2 and adapted by SRNL, utilizes an extraction procedure divided into seven separate tests for different species of mercury. In the SRNL’s modified procedure four of these tests were applied to a washed sample of high level radioactive waste sludge.

Utilization of optimized BCR three-step sequential and dilute HCl single extraction procedures for soil-plant metal transfer predictions in contaminated lands.

PubMed

Kubová, Jana; Matús, Peter; Bujdos, Marek; Hagarová, Ingrid; Medved', Ján

2008-05-30

The prediction of soil metal phytoavailability using the chemical extractions is a conventional approach routinely used in soil testing. The adequacy of such soil tests for this purpose is commonly assessed through a comparison of extraction results with metal contents in relevant plants. In this work, the fractions of selected risk metals (Al, As, Cd, Cu, Fe, Mn, Ni, Pb, Zn) that can be taken up by various plants were obtained by optimized BCR (Community Bureau of Reference) three-step sequential extraction procedure (SEP) and by single 0.5 mol L(-1) HCl extraction. These procedures were validated using five soil and sediment reference materials (SRM 2710, SRM 2711, CRM 483, CRM 701, SRM RTH 912) and applied to significantly different acidified soils for the fractionation of studied metals. The new indicative values of Al, Cd, Cu, Fe, Mn, P, Pb and Zn fractional concentrations for these reference materials were obtained by the dilute HCl single extraction. The influence of various soil genesis, content of essential elements (Ca, Mg, K, P) and different anthropogenic sources of acidification on extraction yields of individual risk metal fractions was investigated. The concentrations of studied elements were determined by atomic spectrometry methods (flame, graphite furnace and hydride generation atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry). It can be concluded that the data of extraction yields from first BCR SEP acid extractable step and soil-plant transfer coefficients can be applied to the prediction of qualitative mobility of selected risk metals in different soil systems.

A protocol for combined Photinus and Renilla luciferase quantification compatible with protein assays.

PubMed

Hampf, Mathias; Gossen, Manfred

2006-09-01

We established a quantitative reporter gene protocol, the P/Rluc assay system, allowing the sequential measurement of Photinus and Renilla luciferase activities from the same extract. Other than comparable commercial reporter assay systems and their noncommercial counterparts, the P/Rluc assay system was formulated under the aspect of full compatibility with standard methods for protein assays. This feature greatly expands the range of applications for assay systems quantifying the expression of multiple luciferase reporters.

EXTRACTION OF SEDIMENT-BOUND CHLORINATED ORGANIC COMPOUNDS: IMPLICATIONS ON FATE AND HAZARD ASSESSMENT. (R825513C007)

EPA Science Inventory

Five methods were used for the extraction of hexachlorobutadiene and chlorobenzenes from a contaminated estuarine sediment. The following extraction methods were used: Soxhlet extraction, sonication and solvent extraction, sequential solvent extraction, saponification and solv...

Sequential state discrimination and requirement of quantum dissonance

NASA Astrophysics Data System (ADS)

Pang, Chao-Qian; Zhang, Fu-Lin; Xu, Li-Fang; Liang, Mai-Lin; Chen, Jing-Ling

2013-11-01

We study the procedure for sequential unambiguous state discrimination. A qubit is prepared in one of two possible states and measured by two observers Bob and Charlie sequentially. A necessary condition for the state to be unambiguously discriminated by Charlie is the absence of entanglement between the principal qubit, prepared by Alice, and Bob's auxiliary system. In general, the procedure for both Bob and Charlie to recognize between two nonorthogonal states conclusively relies on the availability of quantum discord which is precisely the quantum dissonance when the entanglement is absent. In Bob's measurement, the left discord is positively correlated with the information extracted by Bob, and the right discord enhances the information left to Charlie. When their product achieves its maximum the probability for both Bob and Charlie to identify the state achieves its optimal value.

Stormwater Effects on Heavy Metal Sequestration in a Bioretention System in Culver City, California

NASA Astrophysics Data System (ADS)

Yousavich, D. J.; Ellis, A. S.; Dorsey, J.; Johnston, K.

2017-12-01

Rain Gardens, also referred to as bioretention or biofilters, are often used to capture or filter urban runoff before it drains into surface or groundwater systems. The Culver City Rain Garden (CCRG) is one such system that is designed to capture and filter runoff from approximately 11 acres of mixed-use commercial and industrial land before it enters Ballona Creek. The EPA has designated Ballona Creek as an impaired waterway and established Total Maximum Daily Loads for heavy metals. Previous research has utilized sequential extractions to establish trends in heavy metal sequestration for Cu, Pb, and Zn in bioretention media. The aim of this project is to evaluate if there is a difference in heavy metal sequestration between dry and wetted bioretention media. To characterize the stormwater at the site, influent and surface water were collected and analyzed for sulfate and heavy metals 3 times during the 2016-2017 storm season. Two soil cores from the CCRG were acquired in the summer of 2017 to analyze soil metal sequestration trends. They will be subjected to different wetting conditions, sectioned into discrete depths, and digested with an established sequential extraction technique. Surface water in the CCRG shows average Dissolved Oxygen during wet conditions of 2.92 mg/L and average pH of 6.1 indicating reducing conditions near the surface and the possible protonation of adsorption sites during wet weather conditions. Influent metal data indicate average dissolved iron levels near 1 ppm and influent Cu, Pb, and Zn levels near 0.05, 0.01, and 0.5 ppm respectively. This coupled with average surface water sulfate levels near 3 ppm indicates the potential for iron oxide and sulfide mineral formation depending on redox conditions. The sequential extraction results will elucidate whether heavy metals are adsorbed or are being sequestered in mineral formation. These results will allow for the inclusion of heavy metal sequestration trends in the design of further bioretention projects and maintenance of current sites.

Development of a rapid method for the sequential extraction and subsequent quantification of fatty acids and sugars from avocado mesocarp tissue.

PubMed

Meyer, Marjolaine D; Terry, Leon A

2008-08-27

Methods devised for oil extraction from avocado (Persea americana Mill.) mesocarp (e.g., Soxhlet) are usually lengthy and require operation at high temperature. Moreover, methods for extracting sugars from avocado tissue (e.g., 80% ethanol, v/v) do not allow for lipids to be easily measured from the same sample. This study describes a new simple method that enabled sequential extraction and subsequent quantification of both fatty acids and sugars from the same avocado mesocarp tissue sample. Freeze-dried mesocarp samples of avocado cv. Hass fruit of different ripening stages were extracted by homogenization with hexane and the oil extracts quantified for fatty acid composition by GC. The resulting filter residues were readily usable for sugar extraction with methanol (62.5%, v/v). For comparison, oil was also extracted using the standard Soxhlet technique and the resulting thimble residue extracted for sugars as before. An additional experiment was carried out whereby filter residues were also extracted using ethanol. Average oil yield using the Soxhlet technique was significantly (P < 0.05) higher than that obtained by homogenization with hexane, although the difference remained very slight, and fatty acid profiles of the oil extracts following both methods were very similar. Oil recovery improved with increasing ripeness of the fruit with minor differences observed in the fatty acid composition during postharvest ripening. After lipid removal, methanolic extraction was superior in recovering sucrose and perseitol as compared to 80% ethanol (v/v), whereas mannoheptulose recovery was not affected by solvent used. The method presented has the benefits of shorter extraction time, lower extraction temperature, and reduced amount of solvent and can be used for sequential extraction of fatty acids and sugars from the same sample.

Sequential solvent extraction for forms of antimony in five selected coals

USGS Publications Warehouse

Qi, C.; Liu, Gaisheng; Kong, Y.; Chou, C.-L.; Wang, R.

2008-01-01

Abundance of antimony in bulk samples has been determined in five selected coals, three coals from Huaibei Coalfield, Anhui, China, and two from the Illinois Basin in the United States. The Sb abundance in these samples is in the range of 0.11-0.43 ??g/g. The forms of Sb in coals were studied by sequential solvent extraction. The six forms of Sb are water soluble, ion changeable, organic matter bound, carbonate bound, silicate bound, and sulfide bound. Results of sequential extraction show that silicate-bound Sb is the most abundant form in these coals. Silicate- plus sulfide-bound Sb accounts for more than half of the total Sb in all coals. Bituminous coals are higher in organic matterbound Sb than anthracite and natural coke, indicating that the Sb in the organic matter may be incorporated into silicate and sulfide minerals during metamorphism. ?? 2008 by The University of Chicago. All rights reserved.

Phosphorus Concentrations in Sequentially Fractionated Soil Samples as Affected by Digestion Methods

PubMed Central

do Nascimento, Carlos A. C.; Pagliari, Paulo H.; Schmitt, Djalma; He, Zhongqi; Waldrip, Heidi

2015-01-01

Sequential fractionation has helped improving our understanding of the lability and bioavailability of P in soil. Nevertheless, there have been no reports on how manipulation of the different fractions prior to analyses affects the total P (TP) concentrations measured. This study investigated the effects of sample digestion, filtration, and acidification on the TP concentrations determined by ICP-OES in 20 soil samples. Total P in extracts were either determined without digestion by ICP-OES, or ICP-OES following block digestion, or autoclave digestion. The effects of sample filtration, and acidification on undigested alkaline extracts prior to ICP-OES were also evaluated. Results showed that, TP concentrations were greatest in the block-digested extracts, though the variability introduced by the block-digestion was the highest. Acidification of NaHCO3 extracts resulted in lower TP concentrations, while acidification of NaOH randomly increased or decreased TP concentrations. The precision observed with ICP-OES of undigested extracts suggests this should be the preferred method for TP determination in sequentially extracted samples. Thus, observations reported in this work would be helpful in appropriate sample handling for P determination, thereby improving the precision of P determination. The results are also useful for literature data comparison and discussion when there are differences in sample treatments. PMID:26647644

Semiautomatic sequential extraction of polycyclic aromatic hydrocarbons and elemental bio-accessible fraction by accelerated solvent extraction on a single particulate matter sample.

PubMed

Astolfi, Maria Luisa; Di Filippo, Patrizia; Gentili, Alessandra; Canepari, Silvia

2017-11-01

We describe the optimization and validation of a sequential extractive method for the determination of the polycyclic aromatic hydrocarbons (PAHs) and elements (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, V and Zn) that are chemically fractionated into bio-accessible and mineralized residual fractions on a single particulate matter filter. The extraction is performed by automatic accelerated solvent extraction (ASE); samples are sequentially treated with dichloromethane/acetone (4:1) for PAHs extraction and acetate buffer (0.01M; pH 4.5) for elements extraction (bio-accessible fraction). The remaining solid sample is then collected and subjected to acid digestion with HNO 3 :H 2 O 2 (2:1) to determine the mineralized residual element fraction. We also describe a homemade ASE cell that reduces the blank values for most elements; in this cell, the steel frit was replaced by a Teflon pierced disk and a Teflon cylinder was used as the filler. The performance of the proposed method was evaluated in terms of recovery from standard reference material (SRM 1648 and SRM 1649a) and repeatability. The equivalence between the new ASE method and conventional methods was verified for PAHs and for bio-accessible and mineralized residual fractions of elements on PM 10 twin filters. Copyright © 2017 Elsevier B.V. All rights reserved.

Chromium fate in constructed wetlands treating tannery wastewaters.

PubMed

Dotro, Gabriela; Palazolo, Paul; Larsen, Daniel

2009-06-01

Nine experimental wetlands were built to determine chromium partitioning inside systems treating tannery wastewaters. Results showed 5-day biochemical oxygen demand and chromium removals of 95 to 99% and 90 to 99%, respectively. The majority of chromium was found in association with media (96 to 98%), followed by effluents (2.9 to 3.9%), and the least was found in plant parts (0.1%). Chemical speciation modeling of solutions and scanning electron microscope analysis suggest two potential chromium removal mechanisms--sorption/coprecipitation with iron hydroxides or oxyhydroxides and biomass sorption. The release of the majority of chromium in the iron- and organic-bound phases during sequential extractions supports the proposed dominant removal mechanisms. The use of a mixture of peat and gravel resulted in lower removal efficiencies and stronger partitioning in organic phases during sequential extractions. Chromium was efficiently removed by wetlands, retained through chemical and biological processes. Future research will focus on further exploring removal mechanisms and proposing management strategies for the chromium-containing wetland media.

Optimization of Fe2+ supplement in anaerobic digestion accounting for the Fe-bioavailability.

PubMed

Cai, Yafan; Zhao, Xiaoling; Zhao, Yubin; Wang, Hongliang; Yuan, Xufeng; Zhu, Wanbin; Cui, Zongjun; Wang, Xiaofen

2018-02-01

Fe is widely used as an additive in anaerobic digestion, but its bioavailability and the mechanism by which it enhances digestion are unclear. In this study, sequential extraction was used to measure Fe bioavailability, while biochemical parameters, kinetics model and Q-PCR (fluorescence quantitative PCR) were used to explore its mechanism of stimulation. The results showed that sequential extraction is a suitable method to assess the anaerobic system bioavailability of Fe, which is low and fluctuates to a limited extent (1.7 to -3.1wt%), indicating that it would be easy for Fe levels to be insufficient. Methane yield increased when the added Fe 2+ was 10-500mg/L. Appropriate amounts of Fe 2+ accelerated the decomposition of rice straw and facilitated methanogen metabolism, thereby improving reactor performance. The modified Gompertz model better fitted the results than the first-order kinetic model. Feasibility analysis showed that addition of Fe 2+ at ≤50mg/L was suitable. Copyright © 2017. Published by Elsevier Ltd.

Continued Data Acquisition Development

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

Schwellenbach, David

This task focused on improving techniques for integrating data acquisition of secondary particles correlated in time with detected cosmic-ray muons. Scintillation detectors with Pulse Shape Discrimination (PSD) capability show the most promise as a detector technology based on work in FY13. Typically PSD parameters are determined prior to an experiment and the results are based on these parameters. By saving data in list mode, including the fully digitized waveform, any experiment can effectively be replayed to adjust PSD and other parameters for the best data capture. List mode requires time synchronization of two independent data acquisitions (DAQ) systems: the muonmore » tracker and the particle detector system. Techniques to synchronize these systems were studied. Two basic techniques were identified: real time mode and sequential mode. Real time mode is the preferred system but has proven to be a significant challenge since two FPGA systems with different clocking parameters must be synchronized. Sequential processing is expected to work with virtually any DAQ but requires more post processing to extract the data.« less

Potential for leaching of arsenic from excavated rock after different drying treatments.

PubMed

Li, Jining; Kosugi, Tomoya; Riya, Shohei; Hashimoto, Yohey; Hou, Hong; Terada, Akihiko; Hosomi, Masaaki

2016-07-01

Leaching of arsenic (As) from excavated rock subjected to different drying methods is compared using sequential leaching tests and rapid small-scale column tests combined with a sequential extraction procedure. Although the total As content in the rock was low (8.81 mg kg(-1)), its resulting concentration in the leachate when leached at a liquid-to-solid ratio of 10 L kg(-1) exceeded the environmental standard (10 μg L(-1)). As existed mainly in dissolved forms in the leachates. All of the drying procedures applied in this study increased the leaching of As, with freeze-drying leading to the largest increase. Water extraction of As using the two tests showed different leaching behaviors as a function of the liquid-to-solid ratio, and achieved average extractions of up to 35.7% and 25.8% total As, respectively. Dissolution of As from the mineral surfaces and subsequent re-adsorption controlled the short-term release of As; dissolution of Fe, Al, and dissolved organic carbon played important roles in long-term As leaching. Results of the sequential extraction procedure showed that use of 0.05 M (NH4)2SO4 underestimates the readily soluble As. Long-term water extraction removed almost all of the non-specifically sorbed As and most of the specifically sorbed As. The concept of pollution potential indices, which are easily determined by the sequential leaching test, is proposed in this study and is considered for possible use in assessing efficacy of treatment of excavated rocks. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preliminary results of sequential extraction experiments for selenium on mine waste and stream sediments from Vermont, Maine, and New Zealand

USGS Publications Warehouse

Piatak, N.M.; Seal, R.R.; Sanzolone, R.F.; Lamothe, P.J.; Brown, Z.A.

2006-01-01

We report the preliminary results of sequential partial dissolutions used to characterize the geochemical distribution of selenium in stream sediments, mine wastes, and flotation-mill tailings. In general, extraction schemes are designed to extract metals associated with operationally defined solid phases. Total Se concentrations and the mineralogy of the samples are also presented. Samples were obtained from the Elizabeth, Ely, and Pike Hill mines in Vermont, the Callahan mine in Maine, and the Martha mine in New Zealand. These data are presented here with minimal interpretation or discussion. Further analysis of the data will be presented elsewhere.

Geochemical and multi-isotopic ( 87Sr/ 86Sr, 143Nd/ 144Nd, 238U/ 235U) perspectives of sediment sources, depositional conditions, and diagenesis of the Marcellus Shale, Appalachian Basin, USA

DOE PAGES

Phan, Thai T.; Gardiner, James B.; Capo, Rosemary C.; ...

2017-10-25

Here, we investigate sediment sources, depositional conditions and diagenetic processes affecting the Middle Devonian Marcellus Shale in the Appalachian Basin, eastern USA, a major target of natural gas exploration. Multiple proxies, including trace metal contents, rare earth elements (REE), the Sm-Nd and Rb-Sr isotope systems, and U isotopes were applied to whole rock digestions and sequentially extracted fractions of the Marcellus shale and adjacent units from two locations in the Appalachian Basin. The narrow range of εNd values (from –7.8 to –6.4 at 390 Ma) is consistent with derivation of the clastic sedimentary component of the Marcellus Shale from amore » well-mixed source of fluvial and eolian material of the Grenville orogenic belt, and indicate minimal post-depositional alteration of the Sm-Nd system. While silicate minerals host >80% of the REE in the shale, data from sequentially extracted fractions reflect post-depositional modifications at the mineralogical scale, which is not observed in whole rock REE patterns.« less

Geochemical and multi-isotopic ( 87Sr/ 86Sr, 143Nd/ 144Nd, 238U/ 235U) perspectives of sediment sources, depositional conditions, and diagenesis of the Marcellus Shale, Appalachian Basin, USA

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

Phan, Thai T.; Gardiner, James B.; Capo, Rosemary C.

Here, we investigate sediment sources, depositional conditions and diagenetic processes affecting the Middle Devonian Marcellus Shale in the Appalachian Basin, eastern USA, a major target of natural gas exploration. Multiple proxies, including trace metal contents, rare earth elements (REE), the Sm-Nd and Rb-Sr isotope systems, and U isotopes were applied to whole rock digestions and sequentially extracted fractions of the Marcellus shale and adjacent units from two locations in the Appalachian Basin. The narrow range of εNd values (from –7.8 to –6.4 at 390 Ma) is consistent with derivation of the clastic sedimentary component of the Marcellus Shale from amore » well-mixed source of fluvial and eolian material of the Grenville orogenic belt, and indicate minimal post-depositional alteration of the Sm-Nd system. While silicate minerals host >80% of the REE in the shale, data from sequentially extracted fractions reflect post-depositional modifications at the mineralogical scale, which is not observed in whole rock REE patterns.« less

Bioactive Lipidic Extracts from Octopus (Paraoctopus limaculatus): Antimutagenicity and Antiproliferative Studies

PubMed Central

Moreno-Félix, Carolina; Wilson-Sánchez, Griselda; Cruz-Ramírez, Susana-Gabriela; Velázquez-Contreras, Carlos; Plascencia-Jatomea, Maribel; Acosta, Ana; Machi-Lara, Lorena; Aldana-Madrid, María-Lourdes; Ezquerra-Brauer, Josafat-Marina; Rocha-Alonzo, Fernando; Burgos-Hernández, Armando

2013-01-01

Fractions from an organic extract from fresh octopus (Paraoctopus limaculatus) were studied for biological activities such as antimutagenic and antiproliferative properties using Salmonella tester strains TA98 and TA100 with metabolic activation (S9) and a cancer cell line (B-cell lymphoma), respectively. A chloroform extract obtained from octopus tentacles was sequentially fractionated using thin layer chromatography (TLC), and each fraction was tested for antimutagenic and antiproliferative activities. Organic extract reduced the number of revertants caused by aflatoxin B1 showing a dose-response type of relationship. Sequential TLC fractionation of the active extracts produced several antimutagenic and/or antiproliferative fractions. Based on the results obtained, the isolated fractions obtained from octopus contain compounds with chemoprotective properties that reduce the mutagenicity of AFB1 and proliferation of cancer cell lines. PMID:23401709

Inertial navigation sensor integrated obstacle detection system

NASA Technical Reports Server (NTRS)

Bhanu, Bir (Inventor); Roberts, Barry A. (Inventor)

1992-01-01

A system that incorporates inertial sensor information into optical flow computations to detect obstacles and to provide alternative navigational paths free from obstacles. The system is a maximally passive obstacle detection system that makes selective use of an active sensor. The active detection typically utilizes a laser. Passive sensor suite includes binocular stereo, motion stereo and variable fields-of-view. Optical flow computations involve extraction, derotation and matching of interest points from sequential frames of imagery, for range interpolation of the sensed scene, which in turn provides obstacle information for purposes of safe navigation.

Multi-Level Sequential Pattern Mining Based on Prime Encoding

NASA Astrophysics Data System (ADS)

Lianglei, Sun; Yun, Li; Jiang, Yin

Encoding is not only to express the hierarchical relationship, but also to facilitate the identification of the relationship between different levels, which will directly affect the efficiency of the algorithm in the area of mining the multi-level sequential pattern. In this paper, we prove that one step of division operation can decide the parent-child relationship between different levels by using prime encoding and present PMSM algorithm and CROSS-PMSM algorithm which are based on prime encoding for mining multi-level sequential pattern and cross-level sequential pattern respectively. Experimental results show that the algorithm can effectively extract multi-level and cross-level sequential pattern from the sequence database.

SW-846 Test Method 3200: Mercury Species Fractionation and Quantification by Microwave Assisted Extraction, Selective Solvent Extraction and/or Solid Phase Extraction

EPA Pesticide Factsheets

a sequential extraction and separation procedure that maybe used in conjunction with a determinative method to differentiate mercury species that arepresent in soils and sediments. provides information on both total mercury andvarious mercury species.

Potential contaminants at a dredged spoil placement site, Charles City County, Virginia, as revealed by sequential extraction

PubMed Central

Tang, Jianwu; Whittecar, G Richard; Johannesson, Karen H; Daniels, W Lee

2004-01-01

Backfills of dredged sediments onto a former sand and gravel mine site in Charles City County, VA may have the potential to contaminate local groundwater. To evaluate the mobility of trace elements and to identify the potential contaminants from the dredged sediments, a sequential extraction scheme was used to partition trace elements associated with the sediments from the local aquifer and the dredged sediments into five fractions: exchangeable, acidic, reducible, oxidizable, and residual phases. Sequential extractions indicate that, for most of the trace elements examined, the residual phases account for the largest proportion of the total concentrations, and their total extractable fractions are mainly from reducible and oxidizable phases. Only Cd, Pb, and Zn have an appreciable extractable proportion from the acidic phase in the filled dredged sediments. Our groundwater monitoring data suggest that the dredged sediments are mainly subject to a decrease in pH and a series of oxidation reactions, when exposed to the atmosphere. Because the trace elements released by carbonate dissolution and the oxidation (e.g., organic matter degradation, iron sulfide and, ammonia oxidation) are subsequently immobilized by sorption to iron, manganese, and aluminum oxides, no potential contaminants to local groundwater are expected by addition of the dredged sediments to this site.

Sequential extraction of flavonoids and pectin from yellow passion fruit rind using pressurized solvent or ultrasound.

PubMed

de Souza, Caroline G; Rodrigues, Tigressa Hs; E Silva, Lorena Ma; Ribeiro, Paulo Rv; de Brito, Edy S

2018-03-01

Passion fruit rind (PFR) represents 90% of the total fruit weight and is wasted during juice processing. Passion fruit rind is known to contain flavonoids and pectin. An alternative use for this fruit juice industrial residue is to obtain these compounds. This study aimed to verify the influence of pressurized solvent extraction (PSE) or ultrasound assisted extraction (UAE) of flavonoid and pectin in a sequential process. The PSE using ethanol at 60:40 (v/v) yielded a total polyphenol content of 4.67 g GAE kg -1 PFR, orientin-7-O-glucoside (1.57 g kg -1 PFR) and luteolin-6-C-glucoside (2.44 g kg -1 PFR). Pectin yield was 165 g kg -1 PFR, either in PSE or UAE. Pectin characterization indicates that the pectic structure has basically homogalacturonans and galacturonate followed by a galacturonic acid ester unit, with methylation degree of 70%. With this study it can be concluded that mixtures of alcohols with water favor the extraction of bioactive compounds of passion fruit peel. Both PSE and UAE were effective in sequentially extracting flavonoids and pectin. The preferred solvent is ethanol due to its lower toxicity. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Speciations of trace metals in the Danube alluvial sediments within an oil refinery.

PubMed

Relić, Dubravka; Dordević, Dragana; Popović, Aleksandar; Blagojević, Tamara

2005-07-01

A sequential extraction procedure was applied to identify forms of Ni, Zn, Pb and Cu with Fe- and Mn-oxides associated in alluvial sediments of the River Danube within Pancevo Oil Refinery (Serbia). The five steps of the sequential extraction procedure partitioned metals into: CH(3)COONH(4) extractable (S1); NH(2)OH.HCl carbonate extractable and easily reducible (S2); (NH(4))(2)C(2)O(2)/H(2)C(2)O(2) moderately reducible (S3); H(2)O(2)-HNO(3) organic extractable (S4); and HCl acid soluble residue (S5). Extracted concentrations of trace metals, analyzed after all five steps, were found to be (mg kg(-1)) for Mn: 656, Fe: 26734, Ni: 32.3, Zn: 72.8, Pb: 13.4 and Cu: 27.0. Most of the elements were found in acid soluble residue, characterizing stable compounds in sediments. Non-residual fractions of trace metals (sum of the first four fractions) were analyzed because they are more bioavailable than the residual amount. Correlation analysis and two multivariate analysis methods (principal component and cluster analysis) were used to understand and visualize the associations between the non-residual fractions of trace metals and certain forms, more or less crystalline of Fe- and Mn-oxides within the analyzed sediments, since Fe- and Mn-oxides play an important role in trace metal sorption within aquatic systems, especially within the Danube alluvium where the fluctuations of groundwater are very frequent and the level of groundwater could come close to surface.

Nuclear events of apoptosis in vitro in cell-free mitotic extracts: a model system for analysis of the active phase of apoptosis

PubMed Central

1993-01-01

We have developed a cell-free system that induces the morphological transformations characteristic of apoptosis in isolated nuclei. The system uses extracts prepared from mitotic chicken hepatoma cells following a sequential S phase/M phase synchronization. When nuclei are added to these extracts, the chromatin becomes highly condensed into spherical domains that ultimately extrude through the nuclear envelope, forming apoptotic bodies. The process is highly synchronous, and the structural changes are completed within 60 min. Coincident with these morphological changes, the nuclear DNA is cleaved into a nucleosomal ladder. Both processes are inhibited by Zn2+, an inhibitor of apoptosis in intact cells. Nuclear lamina disassembly accompanies these structural changes in added nuclei, and we show that lamina disassembly is a characteristic feature of apoptosis in intact cells of mouse, human and chicken. This system may provide a powerful means of dissecting the biochemical mechanisms underlying the final stages of apoptosis. PMID:8408207

Learning to Monitor Machine Health with Convolutional Bi-Directional LSTM Networks

PubMed Central

Zhao, Rui; Yan, Ruqiang; Wang, Jinjiang; Mao, Kezhi

2017-01-01

In modern manufacturing systems and industries, more and more research efforts have been made in developing effective machine health monitoring systems. Among various machine health monitoring approaches, data-driven methods are gaining in popularity due to the development of advanced sensing and data analytic techniques. However, considering the noise, varying length and irregular sampling behind sensory data, this kind of sequential data cannot be fed into classification and regression models directly. Therefore, previous work focuses on feature extraction/fusion methods requiring expensive human labor and high quality expert knowledge. With the development of deep learning methods in the last few years, which redefine representation learning from raw data, a deep neural network structure named Convolutional Bi-directional Long Short-Term Memory networks (CBLSTM) has been designed here to address raw sensory data. CBLSTM firstly uses CNN to extract local features that are robust and informative from the sequential input. Then, bi-directional LSTM is introduced to encode temporal information. Long Short-Term Memory networks (LSTMs) are able to capture long-term dependencies and model sequential data, and the bi-directional structure enables the capture of past and future contexts. Stacked, fully-connected layers and the linear regression layer are built on top of bi-directional LSTMs to predict the target value. Here, a real-life tool wear test is introduced, and our proposed CBLSTM is able to predict the actual tool wear based on raw sensory data. The experimental results have shown that our model is able to outperform several state-of-the-art baseline methods. PMID:28146106

Learning to Monitor Machine Health with Convolutional Bi-Directional LSTM Networks.

PubMed

Zhao, Rui; Yan, Ruqiang; Wang, Jinjiang; Mao, Kezhi

2017-01-30

In modern manufacturing systems and industries, more and more research efforts have been made in developing effective machine health monitoring systems. Among various machine health monitoring approaches, data-driven methods are gaining in popularity due to the development of advanced sensing and data analytic techniques. However, considering the noise, varying length and irregular sampling behind sensory data, this kind of sequential data cannot be fed into classification and regression models directly. Therefore, previous work focuses on feature extraction/fusion methods requiring expensive human labor and high quality expert knowledge. With the development of deep learning methods in the last few years, which redefine representation learning from raw data, a deep neural network structure named Convolutional Bi-directional Long Short-Term Memory networks (CBLSTM) has been designed here to address raw sensory data. CBLSTM firstly uses CNN to extract local features that are robust and informative from the sequential input. Then, bi-directional LSTM is introduced to encode temporal information. Long Short-Term Memory networks(LSTMs) are able to capture long-term dependencies and model sequential data, and the bi-directional structure enables the capture of past and future contexts. Stacked, fully-connected layers and the linear regression layer are built on top of bi-directional LSTMs to predict the target value. Here, a real-life tool wear test is introduced, and our proposed CBLSTM is able to predict the actual tool wear based on raw sensory data. The experimental results have shown that our model is able to outperform several state-of-the-art baseline methods.

Pumpkin (Cucurbita maxima) seed proteins: sequential extraction processing and fraction characterization.

PubMed

Rezig, Leila; Chibani, Farhat; Chouaibi, Moncef; Dalgalarrondo, Michèle; Hessini, Kamel; Guéguen, Jacques; Hamdi, Salem

2013-08-14

Seed proteins extracted from Tunisian pumpkin seeds ( Cucurbita maxima ) were investigated for their solubility properties and sequentially extracted according to the Osborne procedure. The solubility of pumpkin proteins from seed flour was greatly influenced by pH changes and ionic strength, with higher values in the alkaline pH regions. It also depends on the seed defatting solvent. Protein solubility was decreased by using chloroform/methanol (CM) for lipid extraction instead of pentane (P). On the basis of differential solubility fractionation and depending on the defatting method, the alkali extract (AE) was the major fraction (42.1 (P), 22.3% (CM)) compared to the salt extract (8.6 (P), 7.5% (CM)). In salt, alkali, and isopropanol extracts, all essential amino acids with the exceptions of threonine and lysine met the minimum requirements for preschool children (FAO/WHO/UNU). The denaturation temperatures were 96.6 and 93.4 °C for salt and alkali extracts, respectively. Pumpkin protein extracts with unique protein profiles and higher denaturation temperatures could impart novel characteristics when used as food ingredients.

THE LIBERATION OF ARSENOSUGARS FROM MATRIX COMPONENTS IN DIFFICULT TO EXTRACT SEAFOOD SAMPLES UTILIZING TMAOH/ACETIC ACID SEQUENTIALLY IN A TWO-STAGE EXTRACTION PROCESS

EPA Science Inventory

Sample extraction is one of the most important steps in arsenic speciation analysis of solid dietary samples. One of the problem areas in this analysis is the partial extraction of arsenicals from seafood samples. The partial extraction allows the toxicity of the extracted arse...

Learning Behavior Characterization with Multi-Feature, Hierarchical Activity Sequences

ERIC Educational Resources Information Center

Ye, Cheng; Segedy, James R.; Kinnebrew, John S.; Biswas, Gautam

2015-01-01

This paper discusses Multi-Feature Hierarchical Sequential Pattern Mining, MFH-SPAM, a novel algorithm that efficiently extracts patterns from students' learning activity sequences. This algorithm extends an existing sequential pattern mining algorithm by dynamically selecting the level of specificity for hierarchically-defined features…

Screening antimutagenic and antiproliferative properties of extracts isolated from Jackfruit pulp (Artocarpus heterophyllus Lam).

PubMed

Ruiz-Montañez, G; Burgos-Hernández, A; Calderón-Santoyo, M; López-Saiz, C M; Velázquez-Contreras, C A; Navarro-Ocaña, A; Ragazzo-Sánchez, J A

2015-05-15

The present focused on the study of the antimutagenic and antiproliferative potential of pulp Jackfruit (Artocarpus heterophyllus Lam) extract, using Salmonella typhimurium tester strains TA98 and TA100 with metabolic activation (S9) and a cancer cell line M12.C3.F6 (murine B-cell lymphoma), respectively. Jackfruit pulp extract was sequentially fractionated by chromatography (RP-HPLC) and each fraction was tested for antimutagenic and antiproliferative activities. The organic extracts obtained from Jackfruit pulp reduced the number of revertants caused by aflatoxin B1 (AFB1) and proliferation of cells M12.C3.F6; a dose-response relationship was showed. Sequential RP-HPLC fractionation of the active extracts produced both antimutagenic and/or antiproliferative fractions. These results suggested that the Jackfruit contained compounds with chemoprotective properties to reduce the mutagenicity of AFB1, also proliferation of a cancer cell line. Copyright © 2014 Elsevier Ltd. All rights reserved.

Feature Extraction in Sequential Multimedia Images: with Applications in Satellite Images and On-line Videos

NASA Astrophysics Data System (ADS)

Liang, Yu-Li

Multimedia data is increasingly important in scientific discovery and people's daily lives. Content of massive multimedia is often diverse and noisy, and motion between frames is sometimes crucial in analyzing those data. Among all, still images and videos are commonly used formats. Images are compact in size but do not contain motion information. Videos record motion but are sometimes too big to be analyzed. Sequential images, which are a set of continuous images with low frame rate, stand out because they are smaller than videos and still maintain motion information. This thesis investigates features in different types of noisy sequential images, and the proposed solutions that intelligently combined multiple features to successfully retrieve visual information from on-line videos and cloudy satellite images. The first task is detecting supraglacial lakes above ice sheet in sequential satellite images. The dynamics of supraglacial lakes on the Greenland ice sheet deeply affect glacier movement, which is directly related to sea level rise and global environment change. Detecting lakes above ice is suffering from diverse image qualities and unexpected clouds. A new method is proposed to efficiently extract prominent lake candidates with irregular shapes, heterogeneous backgrounds, and in cloudy images. The proposed system fully automatize the procedure that track lakes with high accuracy. We further cooperated with geoscientists to examine the tracked lakes and found new scientific findings. The second one is detecting obscene content in on-line video chat services, such as Chatroulette, that randomly match pairs of users in video chat sessions. A big problem encountered in such systems is the presence of flashers and obscene content. Because of various obscene content and unstable qualities of videos capture by home web-camera, detecting misbehaving users is a highly challenging task. We propose SafeVchat, which is the first solution that achieves satisfactory detection rate by using facial features and skin color model. To harness all the features in the scene, we further developed another system using multiple types of local descriptors along with Bag-of-Visual Word framework. In addition, an investigation of new contour feature in detecting obscene content is presented.

Molecular Characteristics of Kraft-AQ Pulping Lignin Fractionated by Sequential Organic Solvent Extraction

PubMed Central

Wang, Kun; Xu, Feng; Sun, Runcang

2010-01-01

Kraft-AQ pulping lignin was sequentially fractionated by organic solvent extractions and the molecular properties of each fraction were characterized by chemical degradation, GPC, UV, FT-IR, 13C-NMR and thermal analysis. The average molecular weight and polydispersity of each lignin fraction increased with its hydrogen-bonding capacity (Hildebrand solubility parameter). In addition, the ratio of the non-condensed guaiacyl/syringyl units and the content of β-O-4 linkages increased with the increment of the lignin fractions extracted successively with hexane, diethylether, methylene chloride, methanol, and dioxane. Furthermore, the presence of the condensation reaction products was contributed to the higher thermal stability of the larger molecules. PMID:21152286

Comparison of bioavailable vanadium in alfalfa rhizosphere soil extracted by an improved BCR procedure and EDTA, HCl, and NaNO₃ single extractions in a pot experiment with V-Cd treatments.

PubMed

Yang, Jie; Teng, Yanguo; Zuo, Rui; Song, Liuting

2015-06-01

The BCR sequential extraction procedure was compared with EDTA, HCl, and NaNO3 single extractions for evaluating vanadium bioavailability in alfalfa rhizosphere soil. The amounts of vanadium extracted by these methods were in the following order: BCR (bioavailable V) > EDTA ≈ HCl > NaNO3. Both correlation analysis and stepwise regression were adopted to illustrate the extractable vanadium between different reagents. The correlation coefficients between extracted vanadium and the vanadium contents in alfalfa roots were R NaNO3 = 0.948, R HCl = 0.902, R EDTA = 0.816, and R bioavailable V = 0.819. The stepwise multiple regression equation of the NaNO3 extraction was the most significant at a 95 % confidence interval. The influence of pH, total organic carbon, and cadmium content of soil to vanadium bioavailability were not definite. In summary, both the BCR sequential extraction and the single extraction methods were valid approaches for predicting vanadium bioavailability in alfalfa rhizosphere soil, especially the single extractions.

Selenium speciation in phosphate mine soils and evaluation of a sequential extraction procedure using XAFS.

PubMed

Favorito, Jessica E; Luxton, Todd P; Eick, Matthew J; Grossl, Paul R

2017-10-01

Selenium is a trace element found in western US soils, where ingestion of Se-accumulating plants has resulted in livestock fatalities. Therefore, a reliable understanding of Se speciation and bioavailability is critical for effective mitigation. Sequential extraction procedures (SEP) are often employed to examine Se phases and speciation in contaminated soils but may be limited by experimental conditions. We examined the validity of a SEP using X-ray absorption spectroscopy (XAS) for both whole and a sequence of extracted soils. The sequence included removal of soluble, PO 4 -extractable, carbonate, amorphous Fe-oxide, crystalline Fe-oxide, organic, and residual Se forms. For whole soils, XANES analyses indicated Se(0) and Se(-II) predominated, with lower amounts of Se(IV) present, related to carbonates and Fe-oxides. Oxidized Se species were more elevated and residual/elemental Se was lower than previous SEP results from ICP-AES suggested. For soils from the SEP sequence, XANES results indicated only partial recovery of carbonate, Fe-oxide and organic Se. This suggests Se was incompletely removed during designated extractions, possibly due to lack of mineral solubilization or reagent specificity. Selenium fractions associated with Fe-oxides were reduced in amount or removed after using hydroxylamine HCl for most soils examined. XANES results indicate partial dissolution of solid-phases may occur during extraction processes. This study demonstrates why precautions should be taken to improve the validity of SEPs. Mineralogical and chemical characterizations should be completed prior to SEP implementation to identify extractable phases or mineral components that may influence extraction effectiveness. Sequential extraction procedures can be appropriately tailored for reliable quantification of speciation in contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Partitioning of radionuclides and trace elements in phosphogypsum and its source materials based on sequential extraction methods.

PubMed

Santos, A J G; Mazzilli, B P; Fávaro, D I T; Silva, P S C

2006-01-01

Phosphogypsum is a waste produced by the phosphate fertilizer industry. Although phosphogypsum is mainly calcium sulphate dihydrate, it contains elevated levels of impurities, which originate from the source phosphate rock used in the phosphoric acid production. Among these impurities, radionuclides from 238U and 232Th decay series are of most concern due to their radiotoxicity. Other elements, such as rare earth elements (REE) and Ba are also enriched in the phosphogypsum. The bioavailability of radionuclides (226Ra, 210Pb and 232Th), rare earth elements and Ba to the surrounding aquatic system was evaluated by the application of sequential leaching of the phosphogypsum samples from the Brazilian phosphoric acid producers. The sequential extraction results show that most of the radium and lead are located in the "iron oxide" (non-CaSO4) fraction, and that only 13-18% of these radionuclides are distributed in the most labile fraction. Th, REE and Ba were found predominantly in the residual phase, which corresponds to a small fraction of the phosphate rock or monazite that did not react and to insoluble compounds such as sulphates, phosphates and silicates. It can be concluded that although all these elements are enriched in the phosphogypsum samples they are not associated with CaSO4 itself and therefore do not represent a threat to the surrounding aquatic environment.

Sequential geophysical and flow inversion to characterize fracture networks in subsurface systems

DOE PAGES

Mudunuru, Maruti Kumar; Karra, Satish; Makedonska, Nataliia; ...

2017-09-05

Subsurface applications, including geothermal, geological carbon sequestration, and oil and gas, typically involve maximizing either the extraction of energy or the storage of fluids. Fractures form the main pathways for flow in these systems, and locating these fractures is critical for predicting flow. However, fracture characterization is a highly uncertain process, and data from multiple sources, such as flow and geophysical are needed to reduce this uncertainty. We present a nonintrusive, sequential inversion framework for integrating data from geophysical and flow sources to constrain fracture networks in the subsurface. In this framework, we first estimate bounds on the statistics formore » the fracture orientations using microseismic data. These bounds are estimated through a combination of a focal mechanism (physics-based approach) and clustering analysis (statistical approach) of seismic data. Then, the fracture lengths are constrained using flow data. In conclusion, the efficacy of this inversion is demonstrated through a representative example.« less

Sequential geophysical and flow inversion to characterize fracture networks in subsurface systems

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

Mudunuru, Maruti Kumar; Karra, Satish; Makedonska, Nataliia

Subsurface applications, including geothermal, geological carbon sequestration, and oil and gas, typically involve maximizing either the extraction of energy or the storage of fluids. Fractures form the main pathways for flow in these systems, and locating these fractures is critical for predicting flow. However, fracture characterization is a highly uncertain process, and data from multiple sources, such as flow and geophysical are needed to reduce this uncertainty. We present a nonintrusive, sequential inversion framework for integrating data from geophysical and flow sources to constrain fracture networks in the subsurface. In this framework, we first estimate bounds on the statistics formore » the fracture orientations using microseismic data. These bounds are estimated through a combination of a focal mechanism (physics-based approach) and clustering analysis (statistical approach) of seismic data. Then, the fracture lengths are constrained using flow data. In conclusion, the efficacy of this inversion is demonstrated through a representative example.« less

Fractionation and ecotoxicological implication of potentially toxic metals in sediments of three urban rivers and the Lagos Lagoon, Nigeria, West Africa.

PubMed

Oyeyiola, Aderonke O; Davidson, Christine M; Olayinka, Kehinde O; Alo, Babajide I

2014-11-01

The potential environmental impact of sediment-bound Cd, Cr, Cu, Pb and Zn in three trans-urban rivers in Lagos state and in the Lagos Lagoon was assessed by use of the modified Community Bureau of Reference (BCR) sequential extraction. The quality of the data was checked using BCR CRM 143R and BCR CRM 701. Good agreement was obtained between found and certified/indicative values. Of the rivers, the Odo-Iyaalaro, was generally the most contaminated and the Ibeshe the least. Higher concentrations of metals were generally found in the dry season compared to the wet season. Cadmium and Zn were released mostly in the acid exchangeable step of the sequential extraction, indicating that they have the greatest potential mobility and bioavailability of the analytes studied. Chromium and Cu were associated mainly with the reducible and oxidisable fractions, and Pb predominantly with the reducible and residual fractions. Sediments with the highest pseudototal analyte concentrations also released higher proportions of analytes earlier in the sequential extraction procedure. The study suggests that, during the dry season, potentially toxic metals (PTM) may accumulate in sediments in relatively labile forms that are released and can potentially be transported or bioaccumulate in the rainy season. Application of risk assessment codes and Hankanson potential risk indices indicated that Cd was the element of greatest concern in the Lagos Lagoon system. The study indicated that there is a need to strengthen environmental management and pollution control measures to reduce risk from PTM, but that even relatively simple strategies, such as seasonal restrictions on dredging and fishing, could be beneficial.

How to improve an un-alterable model forecast? A sequential data assimilation based error updating approach

NASA Astrophysics Data System (ADS)

Gragne, A. S.; Sharma, A.; Mehrotra, R.; Alfredsen, K. T.

2012-12-01

Accuracy of reservoir inflow forecasts is instrumental for maximizing value of water resources and influences operation of hydropower reservoirs significantly. Improving hourly reservoir inflow forecasts over a 24 hours lead-time is considered with the day-ahead (Elspot) market of the Nordic exchange market in perspectives. The procedure presented comprises of an error model added on top of an un-alterable constant parameter conceptual model, and a sequential data assimilation routine. The structure of the error model was investigated using freely available software for detecting mathematical relationships in a given dataset (EUREQA) and adopted to contain minimum complexity for computational reasons. As new streamflow data become available the extra information manifested in the discrepancies between measurements and conceptual model outputs are extracted and assimilated into the forecasting system recursively using Sequential Monte Carlo technique. Besides improving forecast skills significantly, the probabilistic inflow forecasts provided by the present approach entrains suitable information for reducing uncertainty in decision making processes related to hydropower systems operation. The potential of the current procedure for improving accuracy of inflow forecasts at lead-times unto 24 hours and its reliability in different seasons of the year will be illustrated and discussed thoroughly.

Sequential injection system with in-line solid phase extraction and soil mini-column for determination of zinc and copper in soil leachates.

PubMed

Paluch, Justyna; Mesquita, Raquel B R; Cerdà, Víctor; Kozak, Joanna; Wieczorek, Marcin; Rangel, António O S S

2018-08-01

A sequential injection (SI) system equipped with in-line solid phase extraction column and in-line soil mini-column is proposed for determination of zinc and copper in soil leachates. The spectrophotometric determination (560 nm) is based on the reaction of both analytes with 1-(2-Pyridylazo)-2-naphthol (PAN). Zinc is determined after retaining copper on a cationic resin (Chelex100) whereas copper is determined from the difference of the absorbance measured for both analytes, introduced into the system with the use of a different channel, and zinc absorbance. The influence of several potential interferences was studied. Using the developed method, zinc and copper were determined within the concentration ranges of 0.005-0.300 and 0.011-0.200 mg L -1 , and with a relative standard deviation lower than 6.0% and 5.1%, respectively. The detection limits are 1.4 and 3.0 µg/L for determination of zinc and copper, respectively. The developed SI method was verified by the determination of both analytes in synthetic and certified reference materials of water samples, and applied to the determination of the analytes in rain water and soil leachates from laboratory scale soil core column and in-line soil mini-column. Copyright © 2018 Elsevier B.V. All rights reserved.

Application of Sequential Extractions and X-ray Absorption Spectroscopy to Determine the Speciation of Chromium in Northern New Jersey Marsh Soils Developed in Chromite ore Processing Residue (COPR)

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

Elzinga, E.; Cirmo, A

2010-01-01

The Cr speciation in marsh soils developed in weathering chromite ore processing residue (COPR) was characterized using sequential extractions and synchrotron microbeam and bulk X-ray absorption spectroscopic (XAS) analyses. The sequential extractions suggested substantial Cr associated with reducible and oxidizable soil components, and significant non-extractable residual Cr. Notable differences in Cr speciation estimates from three extraction schemes underscore the operationally defined nature of Cr speciation provided by these methods. Micro X-ray fluorescence maps and {mu}-XAS data indicated the presence of {micro}m-sized chromite particles scattered throughout the weathered COPR matrix. These particles derive from the original COPR material, and have relativelymore » high resistance towards weathering, and therefore persist even after prolonged leaching. Bulk XAS data further indicated Cr(III) incorporated in Fe(OH){sub 3}, and Cr(III) associated with organic matter. The low Cr contents of the weathered material (200-850 ppm) compared to unweathered COPR (20,000-60,000 ppm) point to substantial Cr leaching during COPR weathering, with partial repartitioning of released Cr into secondary Fe(OH){sub 3} phases and organics. The effects of anoxia on Cr speciation, and the potential of active COPR weathering releasing Cr(VI) deeper in the profile require further study.« less

Structural and functional comparison of mobile and recalcitrant humic fractions from agricultural soils

USDA-ARS?s Scientific Manuscript database

Mobile humic acid (MHA) and calcium humate (CaHA) are humic fractions sequentially extracted from soil samples. MHA is extracted by dilute NaOH, and CaHA is subsequently extracted by dilute NaOH from the dilute HCl-washed soil residues of the first extraction. This chapter reviews the recent advance...

Environmental assessment and management of metal-rich wastes generated in acid mine drainage passive remediation systems.

PubMed

Macías, Francisco; Caraballo, Manuel A; Nieto, José Miguel

2012-08-30

As acid mine drainage (AMD) remediation is increasingly faced by governments and mining industries worldwide, the generation of metal-rich solid residues from the treatments plants is concomitantly raising. A proper environmental management of these metal-rich wastes requires a detailed characterization of the metal mobility as well as an assessment of this new residues stability. The European standard leaching test EN 12457-2, the US EPA TCLP test and the BCR sequential extraction procedure were selected to address the environmental assessment of dispersed alkaline substrate (DAS) residues generated in AMD passive treatment systems. Significant discrepancies were observed in the hazardousness classification of the residues according to the TCLP or EN 12457-2 test. Furthermore, the absence of some important metals (like Fe or Al) in the regulatory limits employed in both leaching tests severely restricts their applicability for metal-rich wastes. The results obtained in the BCR sequential extraction suggest an important influence of the landfill environmental conditions on the metals released from the wastes. To ensure a complete stability of the pollutants in the studied DAS-wastes the contact with water or any other leaching solutions must be avoided and a dry environment needs to be provided in the landfill disposal selected. Copyright © 2012 Elsevier B.V. All rights reserved.

Sequential fuzzy diagnosis method for motor roller bearing in variable operating conditions based on vibration analysis.

PubMed

Li, Ke; Ping, Xueliang; Wang, Huaqing; Chen, Peng; Cao, Yi

2013-06-21

A novel intelligent fault diagnosis method for motor roller bearings which operate under unsteady rotating speed and load is proposed in this paper. The pseudo Wigner-Ville distribution (PWVD) and the relative crossing information (RCI) methods are used for extracting the feature spectra from the non-stationary vibration signal measured for condition diagnosis. The RCI is used to automatically extract the feature spectrum from the time-frequency distribution of the vibration signal. The extracted feature spectrum is instantaneous, and not correlated with the rotation speed and load. By using the ant colony optimization (ACO) clustering algorithm, the synthesizing symptom parameters (SSP) for condition diagnosis are obtained. The experimental results shows that the diagnostic sensitivity of the SSP is higher than original symptom parameter (SP), and the SSP can sensitively reflect the characteristics of the feature spectrum for precise condition diagnosis. Finally, a fuzzy diagnosis method based on sequential inference and possibility theory is also proposed, by which the conditions of the machine can be identified sequentially as well.

Sequential Fuzzy Diagnosis Method for Motor Roller Bearing in Variable Operating Conditions Based on Vibration Analysis

PubMed Central

Li, Ke; Ping, Xueliang; Wang, Huaqing; Chen, Peng; Cao, Yi

2013-01-01

A novel intelligent fault diagnosis method for motor roller bearings which operate under unsteady rotating speed and load is proposed in this paper. The pseudo Wigner-Ville distribution (PWVD) and the relative crossing information (RCI) methods are used for extracting the feature spectra from the non-stationary vibration signal measured for condition diagnosis. The RCI is used to automatically extract the feature spectrum from the time-frequency distribution of the vibration signal. The extracted feature spectrum is instantaneous, and not correlated with the rotation speed and load. By using the ant colony optimization (ACO) clustering algorithm, the synthesizing symptom parameters (SSP) for condition diagnosis are obtained. The experimental results shows that the diagnostic sensitivity of the SSP is higher than original symptom parameter (SP), and the SSP can sensitively reflect the characteristics of the feature spectrum for precise condition diagnosis. Finally, a fuzzy diagnosis method based on sequential inference and possibility theory is also proposed, by which the conditions of the machine can be identified sequentially as well. PMID:23793021

Assessing the Selectivity of Extractant Solutions for Recovering Labile Arsenic Associated with Iron (Hydr)oxides and Sulfides in Sediments

EPA Science Inventory

Sequential extractions can provide analytical constraints on the identification of mineral phases that control arsenic speciation in sediments. Model solids were used in this study to evaluate different solutions designed to extract arsenic from relatively labile solid phases. ...

Real time on-chip sequential adaptive principal component analysis for data feature extraction and image compression

NASA Technical Reports Server (NTRS)

Duong, T. A.

2004-01-01

In this paper, we present a new, simple, and optimized hardware architecture sequential learning technique for adaptive Principle Component Analysis (PCA) which will help optimize the hardware implementation in VLSI and to overcome the difficulties of the traditional gradient descent in learning convergence and hardware implementation.

Exploiting an automated microfluidic hydrodynamic sequential injection system for determination of phosphate.

PubMed

Khongpet, Wanpen; Pencharee, Somkid; Puangpila, Chanida; Kradtap Hartwell, Supaporn; Lapanantnoppakhun, Somchai; Jakmunee, Jaroon

2018-01-15

A microfluidic hydrodynamic sequential injection (μHSI) spectrophotometric system was designed and fabricated. The system was built by laser engraving a manifold pattern on an acrylic block and sealing with another flat acrylic plate to form a microfluidic channel platform. The platform was incorporated with small solenoid valves to obtain a portable setup for programmable control of the liquid flow into the channel according to the HSI principle. The system was demonstrated for the determination of phosphate using a molybdenum blue method. An ascorbic acid, standard or sample, and acidic molybdate solutions were sequentially aspirated to fill the channel forming a stack zone before flowing to the detector. Under the optimum condition, a linear calibration graph in the range of 0.1-6mg P L -1 was obtained. The detection limit was 0.1mgL -1 . The system is compact (5.0mm thick, 80mm wide × 140mm long), durable, portable, cost-effective, and consumes little amount of chemicals (83μL each of molybdate and ascorbic acid, 133μL of the sample solution and 1.7mL of water carrier/run). It was applied for the determination of phosphate content in extracted soil samples. The percent recoveries of the analysis were obtained in the range of 91.2-107.3. The results obtained agreed well with those of the batch spectrophotometric method. Copyright © 2017 Elsevier B.V. All rights reserved.

Sequential Extraction Results and Mineralogy of Mine Waste and Stream Sediments Associated With Metal Mines in Vermont, Maine, and New Zealand

USGS Publications Warehouse

Piatak, N.M.; Seal, R.R.; Sanzolone, R.F.; Lamothe, P.J.; Brown, Z.A.; Adams, M.

2007-01-01

We report results from sequential extraction experiments and the quantitative mineralogy for samples of stream sediments and mine wastes collected from metal mines. Samples were from the Elizabeth, Ely Copper, and Pike Hill Copper mines in Vermont, the Callahan Mine in Maine, and the Martha Mine in New Zealand. The extraction technique targeted the following operationally defined fractions and solid-phase forms: (1) soluble, adsorbed, and exchangeable fractions; (2) carbonates; (3) organic material; (4) amorphous iron- and aluminum-hydroxides and crystalline manganese-oxides; (5) crystalline iron-oxides; (6) sulfides and selenides; and (7) residual material. For most elements, the sum of an element from all extractions steps correlated well with the original unleached concentration. Also, the quantitative mineralogy of the original material compared to that of the residues from two extraction steps gave insight into the effectiveness of reagents at dissolving targeted phases. The data are presented here with minimal interpretation or discussion and further analyses and interpretation will be presented elsewhere.

Computer vision for driver assistance systems

NASA Astrophysics Data System (ADS)

Handmann, Uwe; Kalinke, Thomas; Tzomakas, Christos; Werner, Martin; von Seelen, Werner

1998-07-01

Systems for automated image analysis are useful for a variety of tasks and their importance is still increasing due to technological advances and an increase of social acceptance. Especially in the field of driver assistance systems the progress in science has reached a level of high performance. Fully or partly autonomously guided vehicles, particularly for road-based traffic, pose high demands on the development of reliable algorithms due to the conditions imposed by natural environments. At the Institut fur Neuroinformatik, methods for analyzing driving relevant scenes by computer vision are developed in cooperation with several partners from the automobile industry. We introduce a system which extracts the important information from an image taken by a CCD camera installed at the rear view mirror in a car. The approach consists of a sequential and a parallel sensor and information processing. Three main tasks namely the initial segmentation (object detection), the object tracking and the object classification are realized by integration in the sequential branch and by fusion in the parallel branch. The main gain of this approach is given by the integrative coupling of different algorithms providing partly redundant information.

Cardiac conduction velocity estimation from sequential mapping assuming known Gaussian distribution for activation time estimation error.

PubMed

Shariat, Mohammad Hassan; Gazor, Saeed; Redfearn, Damian

2016-08-01

In this paper, we study the problem of the cardiac conduction velocity (CCV) estimation for the sequential intracardiac mapping. We assume that the intracardiac electrograms of several cardiac sites are sequentially recorded, their activation times (ATs) are extracted, and the corresponding wavefronts are specified. The locations of the mapping catheter's electrodes and the ATs of the wavefronts are used here for the CCV estimation. We assume that the extracted ATs include some estimation errors, which we model with zero-mean white Gaussian noise values with known variances. Assuming stable planar wavefront propagation, we derive the maximum likelihood CCV estimator, when the synchronization times between various recording sites are unknown. We analytically evaluate the performance of the CCV estimator and provide its mean square estimation error. Our simulation results confirm the accuracy of the proposed method and the error analysis of the proposed CCV estimator.

Antioxidant activity of extracts from the bark of Chamaecyparis lawsoniana (A. Murrary) Parl.

Treesearch

Heng Gao; Todd F. Shupe; Chung Y. Hse; Thomas L. Eberhardt

2006-01-01

The bark of Chamaecyparis lawsoniana (A. Murray) Parl. was extracted with methanol and sequentially partitioned with n-hexane, ethyl acetate, n-butanol and deionized water. The antioxidant activities of the four extracts were evaluated using the DPPH• and ABTS+• methods. The total phenolic...

Field-scale multi-phase LNAPL remediation: Validating a new computational framework against sequential field pilot trials.

PubMed

Sookhak Lari, Kaveh; Johnston, Colin D; Rayner, John L; Davis, Greg B

2018-03-05

Remediation of subsurface systems, including groundwater, soil and soil gas, contaminated with light non-aqueous phase liquids (LNAPLs) is challenging. Field-scale pilot trials of multi-phase remediation were undertaken at a site to determine the effectiveness of recovery options. Sequential LNAPL skimming and vacuum-enhanced skimming, with and without water table drawdown were trialled over 78days; in total extracting over 5m 3 of LNAPL. For the first time, a multi-component simulation framework (including the multi-phase multi-component code TMVOC-MP and processing codes) was developed and applied to simulate the broad range of multi-phase remediation and recovery methods used in the field trials. This framework was validated against the sequential pilot trials by comparing predicted and measured LNAPL mass removal rates and compositional changes. The framework was tested on both a Cray supercomputer and a cluster. Simulations mimicked trends in LNAPL recovery rates (from 0.14 to 3mL/s) across all remediation techniques each operating over periods of 4-14days over the 78day trial. The code also approximated order of magnitude compositional changes of hazardous chemical concentrations in extracted gas during vacuum-enhanced recovery. The verified framework enables longer term prediction of the effectiveness of remediation approaches allowing better determination of remediation endpoints and long-term risks. Copyright © 2017 Commonwealth Scientific and Industrial Research Organisation. Published by Elsevier B.V. All rights reserved.

Understanding Human Motion Skill with Peak Timing Synergy

NASA Astrophysics Data System (ADS)

Ueno, Ken; Furukawa, Koichi

The careful observation of motion phenomena is important in understanding the skillful human motion. However, this is a difficult task due to the complexities in timing when dealing with the skilful control of anatomical structures. To investigate the dexterity of human motion, we decided to concentrate on timing with respect to motion, and we have proposed a method to extract the peak timing synergy from multivariate motion data. The peak timing synergy is defined as a frequent ordered graph with time stamps, which has nodes consisting of turning points in motion waveforms. A proposed algorithm, PRESTO automatically extracts the peak timing synergy. PRESTO comprises the following 3 processes: (1) detecting peak sequences with polygonal approximation; (2) generating peak-event sequences; and (3) finding frequent peak-event sequences using a sequential pattern mining method, generalized sequential patterns (GSP). Here, we measured right arm motion during the task of cello bowing and prepared a data set of the right shoulder and arm motion. We successfully extracted the peak timing synergy on cello bowing data set using the PRESTO algorithm, which consisted of common skills among cellists and personal skill differences. To evaluate the sequential pattern mining algorithm GSP in PRESTO, we compared the peak timing synergy by using GSP algorithm and the one by using filtering by reciprocal voting (FRV) algorithm as a non time-series method. We found that the support is 95 - 100% in GSP, while 83 - 96% in FRV and that the results by GSP are better than the one by FRV in the reproducibility of human motion. Therefore we show that sequential pattern mining approach is more effective to extract the peak timing synergy than non-time series analysis approach.

The PMHT: solutions for some of its problems

NASA Astrophysics Data System (ADS)

Wieneke, Monika; Koch, Wolfgang

2007-09-01

Tracking multiple targets in a cluttered environment is a challenging task. Probabilistic Multiple Hypothesis Tracking (PMHT) is an efficient approach for dealing with it. Essentially PMHT is based on the method of Expectation-Maximization for handling with association conflicts. Linearity in the number of targets and measurements is the main motivation for a further development and extension of this methodology. Unfortunately, compared with the Probabilistic Data Association Filter (PDAF), PMHT has not yet shown its superiority in terms of track-lost statistics. Furthermore, the problem of track extraction and deletion is apparently not yet satisfactorily solved within this framework. Four properties of PMHT are responsible for its problems in track maintenance: Non-Adaptivity, Hospitality, Narcissism and Local Maxima. 1, 2 In this work we present a solution for each of them and derive an improved PMHT by integrating the solutions into the PMHT formalism. The new PMHT is evaluated by Monte-Carlo simulations. A sequential Likelihood-Ratio (LR) test for track extraction has been developed and already integrated into the framework of traditional Bayesian Multiple Hypothesis Tracking. 3 As a multi-scan approach, also the PMHT methodology has the potential for track extraction. In this paper an analogous integration of a sequential LR test into the PMHT framework is proposed. We present an LR formula for track extraction and deletion using the PMHT update formulae. As PMHT provides all required ingredients for a sequential LR calculation, the LR is thus a by-product of the PMHT iteration process. Therefore the resulting update formula for the sequential LR test affords the development of Track-Before-Detect algorithms for PMHT. The approach is illustrated by a simple example.

Sequential extraction of metals from mixed and digested sludge from aerobic WWTPs sited in the south of Spain

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

Alonso, E.; Aparicio, I.; Santos, J.L.

2009-01-15

The content of heavy metals is the major limitation to the application of sewage sludge in soil. However, assessment of the pollution by total metal determination does not reveal the true environmental impact. It is necessary to apply sequential extraction techniques to obtain suitable information about their bioavailability or toxicity. In this paper, sequential extraction of metals from sludge before and after aerobic digestion was applied to sludge from five WWTPs in southern Spain to obtain information about the influence of the digestion treatment in the concentration of the metals. The percentage of each metal as residual, oxidizable, reducible andmore » exchangeable form was calculated. For this purpose, sludge samples were collected from two different points of the plants, namely, sludge from the mixture (primary and secondary sludge) tank (mixed sludge, MS) and the digested-dewatered sludge (final sludge, FS). Heavy metals, Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Ti and Zn, were extracted following the sequential extraction scheme proposed by the Standards, Measurements and Testing Programme of the European Commission and determined by inductively-coupled plasma atomic emission spectrometry. The total concentration of heavy metals in the measured sludge samples did not exceed the limits set out by European legislation and were mainly associated with the two less-available fractions (27-28% as oxidizable metal and 44-50% as residual metal). However, metals as Co (64% in MS and 52% in FS samples), Mn (82% in MS and 79% in FS), Ni (32% in MS and 26% in FS) and Zn (79% in MS and 62% in FS) were present at important percentages as available forms. In addition, results showed a clear increase of the concentration of metals after sludge treatment in the proportion of two less-available fractions (oxidizable and residual metal)« less

Sequential extraction of metals from mixed and digested sludge from aerobic WWTPs sited in the south of Spain.

PubMed

Alonso, E; Aparicio, I; Santos, J L; Villar, P; Santos, A

2009-01-01

The content of heavy metals is the major limitation to the application of sewage sludge in soil. However, assessment of the pollution by total metal determination does not reveal the true environmental impact. It is necessary to apply sequential extraction techniques to obtain suitable information about their bioavailability or toxicity. In this paper, sequential extraction of metals from sludge before and after aerobic digestion was applied to sludge from five WWTPs in southern Spain to obtain information about the influence of the digestion treatment in the concentration of the metals. The percentage of each metal as residual, oxidizable, reducible and exchangeable form was calculated. For this purpose, sludge samples were collected from two different points of the plants, namely, sludge from the mixture (primary and secondary sludge) tank (mixed sludge, MS) and the digested-dewatered sludge (final sludge, FS). Heavy metals, Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Ti and Zn, were extracted following the sequential extraction scheme proposed by the Standards, Measurements and Testing Programme of the European Commission and determined by inductively-coupled plasma atomic emission spectrometry. The total concentration of heavy metals in the measured sludge samples did not exceed the limits set out by European legislation and were mainly associated with the two less-available fractions (27-28% as oxidizable metal and 44-50% as residual metal). However, metals as Co (64% in MS and 52% in FS samples), Mn (82% in MS and 79% in FS), Ni (32% in MS and 26% in FS) and Zn (79% in MS and 62% in FS) were present at important percentages as available forms. In addition, results showed a clear increase of the concentration of metals after sludge treatment in the proportion of two less-available fractions (oxidizable and residual metal).

Speciation of chromium (VI) and total chromium determination in welding dust samples by flow-injection analysis coupled to atomic absorption spectrometry.

PubMed

Girard, L; Hubert, J

1996-11-01

We have studied the speciation of chromium (VI) in stainless-steel welding dusts. The approach used for the analysis of Cr(VI) and total Cr relies on a flow-injection analyzer (FIA) equipped with two different sequential detectors. The system measures Cr(VI). by colorimetry (with 1,5-diphenyl carbohydrazide) and total chromium content by flame atomic absorption spectroscopy (AAS). The extraction of the samples of welding-fume dusts is achieved in a buffer solution (acetic acid and sodium acetate at pH 4). This extraction procedure gives a 96% recovery of chromium (VI). The FIA-AAS system that has been described is also more sensitive, has a lower detection limit (0.005 mug ml(-1)) and gives a better precision (< 1%) than other equivalent systems that have been previously described.

Multifunctional picoliter droplet manipulation platform and its application in single cell analysis.

PubMed

Gu, Shu-Qing; Zhang, Yun-Xia; Zhu, Ying; Du, Wen-Bin; Yao, Bo; Fang, Qun

2011-10-01

We developed an automated and multifunctional microfluidic platform based on DropLab to perform flexible generation and complex manipulations of picoliter-scale droplets. Multiple manipulations including precise droplet generation, sequential reagent merging, and multistep solid-phase extraction for picoliter-scale droplets could be achieved in the present platform. The system precision in generating picoliter-scale droplets was significantly improved by minimizing the thermo-induced fluctuation of flow rate. A novel droplet fusion technique based on the difference of droplet interfacial tensions was developed without the need of special microchannel networks or external devices. It enabled sequential addition of reagents to droplets on demand for multistep reactions. We also developed an effective picoliter-scale droplet splitting technique with magnetic actuation. The difficulty in phase separation of magnetic beads from picoliter-scale droplets due to the high interfacial tension was overcome using ferromagnetic particles to carry the magnetic beads to pass through the phase interface. With this technique, multistep solid-phase extraction was achieved among picoliter-scale droplets. The present platform had the ability to perform complex multistep manipulations to picoliter-scale droplets, which is particularly required for single cell analysis. Its utility and potentials in single cell analysis were preliminarily demonstrated in achieving high-efficiency single-cell encapsulation, enzyme activity assay at the single cell level, and especially, single cell DNA purification based on solid-phase extraction.

Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage.

PubMed

Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, Jim A

2016-11-05

This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H2SO4 and Cu(2+). Sulfate, sulfide, Cu(2+) and pH were monitored throughout the experiment of 123d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7mg SO4(2-) d(-1)) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu(2+) removal were observed in the endogenous control. In algae amended-columns, Cu(2+) was precipitated with biogenic H2S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry. Copyright © 2016 Elsevier B.V. All rights reserved.

Finding False Paths in Sequential Circuits

NASA Astrophysics Data System (ADS)

Matrosova, A. Yu.; Andreeva, V. V.; Chernyshov, S. V.; Rozhkova, S. V.; Kudin, D. V.

2018-02-01

Method of finding false paths in sequential circuits is developed. In contrast with heuristic approaches currently used abroad, the precise method based on applying operations on Reduced Ordered Binary Decision Diagrams (ROBDDs) extracted from the combinational part of a sequential controlling logic circuit is suggested. The method allows finding false paths when transfer sequence length is not more than the given value and obviates the necessity of investigation of combinational circuit equivalents of the given lengths. The possibilities of using of the developed method for more complicated circuits are discussed.

Sequential patterns of essential trace elements composition in Gracilaria verrucosa and its generated products

NASA Astrophysics Data System (ADS)

Izzati, Munifatul; Haryanti, Sri; Parman, Sarjana

2018-05-01

Gracilaria widely known as a source of essential trace elements. However this red seaweeds also has great potential for being developed into commercial products. This study examined the sequential pattern of essential trace elements composition in fresh Gracilaria verrucosa and a selection of its generated products, nemely extracted agar, Gracilaria salt and Gracilaria residue. The sample was collected from a brackish water pond, located in north part Semarang, Central Java. The collected sample was then dried under the sun, and subsequently processed into aformentioned generated products. The Gracilaria salt was obtain by soaking the sun dried Gracilaria overnight in fresh water overnight. The resulted salt solution was then boiled leaving crystal salt. Extracted agar was obtained with alkali agar extraction method. The rest of remaining material was considered as Gracilaria residue. The entire process was repeated 3 times. The compositin of trace elements was examined using ICP-MS Spectrometry. Collected data was then analyzed by ANOVA single factor. Resulting sequential pattern of its essential trace elements composition was compared. A regular table salt was used as controls. Resuts from this study revealed that Gracilaria verrucosa and its all generated products all have similarly patterned the composition of essential trace elements, where Mn>Zn>Cu>Mo. Additionally this pattern is similar to different subspecies of Gracilaria from different location and and different season. However, Gracilaria salt has distinctly different pattern of sequential essential trace elements composition compared to table salt.

Sequential Modular Position and Momentum Measurements of a Trapped Ion Mechanical Oscillator

NASA Astrophysics Data System (ADS)

Flühmann, C.; Negnevitsky, V.; Marinelli, M.; Home, J. P.

2018-04-01

The noncommutativity of position and momentum observables is a hallmark feature of quantum physics. However, this incompatibility does not extend to observables that are periodic in these base variables. Such modular-variable observables have been suggested as tools for fault-tolerant quantum computing and enhanced quantum sensing. Here, we implement sequential measurements of modular variables in the oscillatory motion of a single trapped ion, using state-dependent displacements and a heralded nondestructive readout. We investigate the commutative nature of modular variable observables by demonstrating no-signaling in time between successive measurements, using a variety of input states. Employing a different periodicity, we observe signaling in time. This also requires wave-packet overlap, resulting in quantum interference that we enhance using squeezed input states. The sequential measurements allow us to extract two-time correlators for modular variables, which we use to violate a Leggett-Garg inequality. Signaling in time and Leggett-Garg inequalities serve as efficient quantum witnesses, which we probe here with a mechanical oscillator, a system that has a natural crossover from the quantum to the classical regime.

Sequential Injection Chromatography with an Ultra-short Monolithic Column for the Low-Pressure Separation of α-Tocopherol and γ-Oryzanol in Vegetable Oils and Nutrition Supplements.

PubMed

Thaithet, Sujitra; Kradtap Hartwell, Supaporn; Lapanantnoppakhun, Somchai

2017-01-01

A low-pressure separation procedure of α-tocopherol and γ-oryzanol was developed based on a sequential injection chromatography (SIC) system coupled with an ultra-short (5 mm) C-18 monolithic column, as a lower cost and more compact alternative to the HPLC system. A green sample preparation, dilution with a small amount of hexane followed by liquid-liquid extraction with 80% ethanol, was proposed. Very good separation resolution (R s = 3.26), a satisfactory separation time (10 min) and a total run time including column equilibration (16 min) were achieved. The linear working range was found to be 0.4 - 40 μg with R 2 being more than 0.99. The detection limits of both analytes were 0.28 μg with the repeatability within 5% RSD (n = 7). Quantitative analyses of the two analytes in vegetable oil and nutrition supplement samples, using the proposed SIC method, agree well with the results from HPLC.

Automated clean-up, separation and detection of polycyclic aromatic hydrocarbons in particulate matter extracts from urban dust and diesel standard reference materials using a 2D-LC/2D-GC system.

PubMed

Ahmed, Trifa M; Lim, Hwanmi; Bergvall, Christoffer; Westerholm, Roger

2013-10-01

A multidimensional, on-line coupled liquid chromatographic/gas chromatographic system was developed for the quantification of polycyclic aromatic hydrocarbons (PAHs). A two-dimensional liquid chromatographic system (2D-liquid chromatography (LC)), with three columns having different selectivities, was connected on-line to a two-dimensional gas chromatographic system (2D-gas chromatography (GC)). Samples were cleaned up by combining normal elution and column back-flush of the LC columns to selectively remove matrix constituents and isolate well-defined, PAH enriched fractions. Using this system, the sequential removal of polar, mono/diaromatic, olefinic and alkane compounds from crude extracts was achieved. The LC/GC coupling was performed using a fused silica transfer line into a programmable temperature vaporizer (PTV) GC injector. Using the PTV in the solvent vent mode, excess solvent was removed and the enriched PAH sample extract was injected into the GC. The 2D-GC setup consisted of two capillary columns with different stationary phase selectivities. Heart-cutting of selected PAH compounds in the first GC column (first dimension) and transfer of these to the second GC column (second dimension) increased the baseline resolutions of closely eluting PAHs. The on-line system was validated using the standard reference materials SRM 1649a (urban dust) and SRM 1975 (diesel particulate extract). The PAH concentrations measured were comparable to the certified values and the fully automated LC/GC system performed the clean-up, separation and detection of PAHs in 16 extracts in less than 24 h. The multidimensional, on-line 2D-LC/2D-GC system eliminated manual handling of the sample extracts and minimised the risk of sample loss and contamination, while increasing accuracy and precision.

Sequential injection analysis with chemiluminescence detection for rapid monitoring of commercial Calendula officinalis extractions.

PubMed

Hughes, Rachel R; Scown, David; Lenehan, Claire E

2015-01-01

Plant extracts containing high levels of antioxidants are desirable due to their reported health benefits. Most techniques capable of determining the antioxidant activity of plant extracts are unsuitable for rapid at-line analysis as they require extensive sample preparation and/or long analysis times. Therefore, analytical techniques capable of real-time or pseudo real-time at-line monitoring of plant extractions, and determination of extraction endpoints, would be useful to manufacturers of antioxidant-rich plant extracts. To develop a reliable method for the rapid at-line extraction monitoring of antioxidants in plant extracts. Calendula officinalis extracts were prepared from dried flowers and analysed for antioxidant activity using sequential injection analysis (SIA) with chemiluminescence (CL) detection. The intensity of CL emission from the reaction of acidic potassium permanganate with antioxidants within the extract was used as the analytical signal. The SIA-CL method was applied to monitor the extraction of C. officinalis over the course of a batch extraction to determine the extraction endpoint. Results were compared with those from ultra high performance liquid chromatography (UHPLC). Pseudo real-time, at-line monitoring showed the level of antioxidants in a batch extract of Calendula officinalis plateaued after 100 min of extraction. These results correlated well with those of an offline UHPLC study. SIA-CL was found to be a suitable method for pseudo real-time monitoring of plant extractions and determination of extraction endpoints with respect to antioxidant concentrations. The method was applied at-line in the manufacturing industry. Copyright © 2015 John Wiley & Sons, Ltd.

Sequential injection spectrophotometric determination of oxybenzone in lipsticks.

PubMed

Salvador, A; Chisvert, A; Camarasa, A; Pascual-Martí, M C; March, J G

2001-08-01

A sequential injection (SI) procedure for the spectrophotometric determination of oxybenzone in lipsticks is reported. The colorimetric reaction between nickel and oxybenzone was used. SI parameters such as sample solution volume, reagent solution volume, propulsion flow rate and reaction coil length were studied. The limit of detection was 3 microg ml(-1). The sensitivity was 0.0108+/-0.0002 ml microg(-1). The relative standard deviations of the results were between 6 and 12%. The real concentrations of samples and the values obtained by HPLC were comparable. Microwave sample pre-treatment allowed the extraction of oxybenzone with ethanol, thus avoiding the use of toxic organic solvents. Ethanol was also used as carrier in the SI system. Seventy-two injections per hour can be performed, which means a sample frequency of 24 h(-1) if three replicates are measured for each sample.

Image segmentation for biomedical applications based on alternating sequential filtering and watershed transformation

NASA Astrophysics Data System (ADS)

Gorpas, D.; Yova, D.

2009-07-01

One of the major challenges in biomedical imaging is the extraction of quantified information from the acquired images. Light and tissue interaction leads to the acquisition of images that present inconsistent intensity profiles and thus the accurate identification of the regions of interest is a rather complicated process. On the other hand, the complex geometries and the tangent objects that very often are present in the acquired images, lead to either false detections or to the merging, shrinkage or expansion of the regions of interest. In this paper an algorithm, which is based on alternating sequential filtering and watershed transformation, is proposed for the segmentation of biomedical images. This algorithm has been tested over two applications, each one based on different acquisition system, and the results illustrate its accuracy in segmenting the regions of interest.

Sequential ultrasound-microwave assisted acid extraction (UMAE) of pectin from pomelo peels.

PubMed

Liew, Shan Qin; Ngoh, Gek Cheng; Yusoff, Rozita; Teoh, Wen Hui

2016-12-01

This study aims to optimize sequential ultrasound-microwave assisted extraction (UMAE) on pomelo peel using citric acid. The effects of pH, sonication time, microwave power and irradiation time on the yield and the degree of esterification (DE) of pectin were investigated. Under optimized conditions of pH 1.80, 27.52min sonication followed by 6.40min microwave irradiation at 643.44W, the yield and the DE value of pectin obtained was respectively at 38.00% and 56.88%. Based upon optimized UMAE condition, the pectin from microwave-ultrasound assisted extraction (MUAE), ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE) were studied. The yield of pectin adopting the UMAE was higher than all other techniques in the order of UMAE>MUAE>MAE>UAE. The pectin's galacturonic acid content obtained from combined extraction technique is higher than that obtained from sole extraction technique and the pectin gel produced from various techniques exhibited a pseudoplastic behaviour. The morphological structures of pectin extracted from MUAE and MAE closely resemble each other. The extracted pectin from UMAE with smaller and more regular surface differs greatly from that of UAE. This has substantiated the highest pectin yield of 36.33% from UMAE and further signified their compatibility and potentiality in pectin extraction. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultrasonic Micro-Blades for the Rapid Extraction of Impact Tracks from Aerogel

NASA Technical Reports Server (NTRS)

Ishii, H. A.; Graham, G. A.; Kearsley, A. T.; Grant, P. G.; Snead, C. J.; Bradley, J. P.

2005-01-01

The science return of NASA's Stardust Mission with its valuable cargo of cometary debris hinges on the ability to efficiently extract particles from silica aerogel collectors. The current method for extracting cosmic dust impact tracks is a mature procedure involving sequential perforation of the aerogel with glass needles on computer controlled micromanipulators. This method is highly successful at removing well-defined aerogel fragments of reasonable optical clarity while causing minimal damage to the surrounding aerogel collector tile. Such a system will be adopted by the JSC Astromaterials Curation Facility in anticipation of Stardust s arrival in early 2006. In addition to Stardust, aerogel is a possible collector for future sample return missions and is used for capture of hypervelocity ejecta in high power laser experiments of interest to LLNL. Researchers will be eager to obtain Stardust samples for study as quickly as possible, and rapid extraction tools requiring little construction, training, or investment would be an attractive asset. To this end, we have experimented with micro-blades for the Stardust impact track extraction process. Our ultimate goal is a rapid extraction system in a clean electron beam environment, such as an SEM or dual-beam FIB, for in situ sample preparation, mounting and analysis.

Robust Sensing of Approaching Vehicles Relying on Acoustic Cues

PubMed Central

Mizumachi, Mitsunori; Kaminuma, Atsunobu; Ono, Nobutaka; Ando, Shigeru

2014-01-01

The latest developments in automobile design have allowed them to be equipped with various sensing devices. Multiple sensors such as cameras and radar systems can be simultaneously used for active safety systems in order to overcome blind spots of individual sensors. This paper proposes a novel sensing technique for catching up and tracking an approaching vehicle relying on an acoustic cue. First, it is necessary to extract a robust spatial feature from noisy acoustical observations. In this paper, the spatio-temporal gradient method is employed for the feature extraction. Then, the spatial feature is filtered out through sequential state estimation. A particle filter is employed to cope with a highly non-linear problem. Feasibility of the proposed method has been confirmed with real acoustical observations, which are obtained by microphones outside a cruising vehicle. PMID:24887038

Sequential extraction procedure for determination of uranium, thorium, radium, lead and polonium radionuclides by alpha spectrometry in environmental samples

NASA Astrophysics Data System (ADS)

Oliveira, J. M.; Carvalho, F. P.

2006-01-01

A sequential extraction technique was developed and tested for common naturally-occurring radionuclides. This technique allows the extraction and purification of uranium, thorium, radium, lead, and polonium radionuclides from the same sample. Environmental materials such as water, soil, and biological samples can be analyzed for those radionuclides without matrix interferences in the quality of radioelement purification and in the radiochemical yield. The use of isotopic tracers (232U, 229Th, 224Ra, 209Po, and stable lead carrier) added to the sample in the beginning of the chemical procedure, enables an accurate control of the radiochemical yield for each radioelement. The ion extraction procedure, applied after either complete dissolution of the solid sample with mineral acids or co-precipitation of dissolved radionuclide with MnO2 for aqueous samples, includes the use of commercially available pre-packed columns from Eichrom® and ion exchange columns packed with Bio-Rad resins, in altogether three chromatography columns. All radioactive elements but one are purified and electroplated on stainless steel discs. Polonium is spontaneously plated on a silver disc. The discs are measured using high resolution silicon surface barrier detectors. 210Pb, a beta emitter, can be measured either through the beta emission of 210Bi, or stored for a few months and determined by alpha spectrometry through the in-growth of 210Po. This sequential extraction chromatography technique was tested and validated with the analysis of certified reference materials from the IAEA. Reproducibility was tested through repeated analysis of the same homogeneous material (water sample).

Dynamic leaching and fractionation of trace elements from environmental solids exploiting a novel circulating-flow platform.

PubMed

Mori, Masanobu; Nakano, Koji; Sasaki, Masaya; Shinozaki, Haruka; Suzuki, Shiho; Okawara, Chitose; Miró, Manuel; Itabashi, Hideyuki

2016-02-01

A dynamic flow-through microcolumn extraction system based on extractant re-circulation is herein proposed as a novel analytical approach for simplification of bioaccessibility tests of trace elements in sediments. On-line metal leaching is undertaken in the format of all injection (AI) analysis, which is a sequel of flow injection analysis, but involving extraction under steady-state conditions. The minimum circulation times and flow rates required to determine the maximum bioaccessible pools of target metals (viz., Cu, Zn, Cd, and Pb) from lake and river sediment samples were estimated using Tessier's sequential extraction scheme and an acid single extraction test. The on-line AIA method was successfully validated by mass balance studies of CRM and real sediment samples. Tessier's test in on-line AI format demonstrated to be carried out by one third of extraction time (6h against more than 17 h by the conventional method), with better analytical precision (<9.2% against >15% by the conventional method) and significant decrease in blank readouts as compared with the manual batch counterpart. Copyright © 2015 Elsevier B.V. All rights reserved.

Simultaneous application of chemical oxidation and extraction processes is effective at remediating soil Co-contaminated with petroleum and heavy metals.

PubMed

Yoo, Jong-Chan; Lee, Chadol; Lee, Jeung-Sun; Baek, Kitae

2017-01-15

Chemical extraction and oxidation processes to clean up heavy metals and hydrocarbon from soil have a higher remediation efficiency and take less time than other remediation processes. In batch extraction/oxidation process, 3% hydrogen peroxide (H 2 O 2 ) and 0.1 M ethylenediaminetetraacetic acid (EDTA) could remove approximately 70% of the petroleum and 60% of the Cu and Pb in the soil, respectively. In particular, petroleum was effectively oxidized by H 2 O 2 without addition of any catalysts through dissolution of Fe oxides in natural soils. Furthermore, heavy metals bound to Fe-Mn oxyhydroxides could be extracted by metal-EDTA as well as Fe-EDTA complexation due to the high affinity of EDTA for metals. However, the strong binding of Fe-EDTA inhibited the oxidation of petroleum in the extraction-oxidation sequential process because Fe was removed during the extraction process with EDTA. The oxidation-extraction sequential process did not significantly enhance the extraction of heavy metals from soil, because a small portion of heavy metals remained bound to organic matter. Overall, simultaneous application of oxidation and extraction processes resulted in highly efficient removal of both contaminants; this approach can be used to remove co-contaminants from soil in a short amount of time at a reasonable cost. Copyright © 2016 Elsevier Ltd. All rights reserved.

An integrated process for the recovery of high added-value compounds from olive oil using solid support free liquid-liquid extraction and chromatography techniques.

PubMed

Angelis, Apostolis; Hamzaoui, Mahmoud; Aligiannis, Nektarios; Nikou, Theodora; Michailidis, Dimitris; Gerolimatos, Panagiotis; Termentzi, Aikaterini; Hubert, Jane; Halabalaki, Maria; Renault, Jean-Hugues; Skaltsounis, Alexios-Léandros

2017-03-31

An integrated extraction and purification process for the direct recovery of high added value compounds from extra virgin olive oil (EVOO) is proposed by using solid support free liquid-liquid extraction and chromatography techniques. Two different extraction methods were developed on a laboratory-scale Centrifugal Partition Extractor (CPE): a sequential strategy consisting of several "extraction-recovery" cycles and a continuous strategy based on stationary phase co-current elution. In both cases, EVOO was used as mobile phase diluted in food grade n-hexane (feed mobile phase) and the required biphasic system was obtained by adding ethanol and water as polar solvents. For the sequential process, 17.5L of feed EVOO containing organic phase (i.e. 7L of EVOO treated) were extracted yielding 9.5g of total phenolic fraction corresponding to a productivity of 5.8g/h/L of CPE column. Regarding the second approach, the co-current process, 2L of the feed oil phase (containing to 0.8L of EVOO) were treated at 100mL/min yielding 1.03g of total phenolic fraction corresponding to a productivity of 8.9g/h/L of CPE column. The total phenolic fraction was then fractionated by using stepwise gradient elution Centrifugal Partition Chromatography (CPC). The biphasic solvent systems were composed of n-hexane, ethyl acetate, ethanol and water in different proportions (X/Y/2/3, v/v). In a single run of 4h on a column with a capacity of 1L, 910mg of oleocanthal, 882mg of oleacein, 104mg of hydroxytyrosol were successfully recovered from 5g of phenolic extract with purities of 85%, 92% and 90%, respectively. CPC fractions were then submitted to orthogonal chromatographic steps (adsorption on silica gel or size exclusion chromatography) leading to the isolation of additional eleven compounds belonging to triterpens, phenolic compounds and secoiridoids. Among them, elenolic acid ethylester was found to be new compound. Thin Layer Chromatography (TLC), Nuclear magnetic Resonance (NMR) and High Performance Liquid Chromatography - Diode Array Detector (HPLC-DAD) were used for monitoring and evaluation purposes throughout the entire procedure. Copyright © 2017 Elsevier B.V. All rights reserved.

Protein classification using sequential pattern mining.

PubMed

Exarchos, Themis P; Papaloukas, Costas; Lampros, Christos; Fotiadis, Dimitrios I

2006-01-01

Protein classification in terms of fold recognition can be employed to determine the structural and functional properties of a newly discovered protein. In this work sequential pattern mining (SPM) is utilized for sequence-based fold recognition. One of the most efficient SPM algorithms, cSPADE, is employed for protein primary structure analysis. Then a classifier uses the extracted sequential patterns for classifying proteins of unknown structure in the appropriate fold category. The proposed methodology exhibited an overall accuracy of 36% in a multi-class problem of 17 candidate categories. The classification performance reaches up to 65% when the three most probable protein folds are considered.

VLSI Design of SVM-Based Seizure Detection System With On-Chip Learning Capability.

PubMed

Feng, Lichen; Li, Zunchao; Wang, Yuanfa

2018-02-01

Portable automatic seizure detection system is very convenient for epilepsy patients to carry. In order to make the system on-chip trainable with high efficiency and attain high detection accuracy, this paper presents a very large scale integration (VLSI) design based on the nonlinear support vector machine (SVM). The proposed design mainly consists of a feature extraction (FE) module and an SVM module. The FE module performs the three-level Daubechies discrete wavelet transform to fit the physiological bands of the electroencephalogram (EEG) signal and extracts the time-frequency domain features reflecting the nonstationary signal properties. The SVM module integrates the modified sequential minimal optimization algorithm with the table-driven-based Gaussian kernel to enable efficient on-chip learning. The presented design is verified on an Altera Cyclone II field-programmable gate array and tested using the two publicly available EEG datasets. Experiment results show that the designed VLSI system improves the detection accuracy and training efficiency.

Metabolic routes along digestive system of licorice: multicomponent sequential metabolism method in rat.

PubMed

Zhang, Lei; Zhao, Haiyu; Liu, Yang; Dong, Honghuan; Lv, Beiran; Fang, Min; Zhao, Huihui

2016-06-01

This study was conducted to establish the multicomponent sequential metabolism (MSM) method based on comparative analysis along the digestive system following oral administration of licorice (Glycyrrhiza uralensis Fisch., leguminosae), a traditional Chinese medicine widely used for harmonizing other ingredients in a formulae. The licorice water extract (LWE) dissolved in Krebs-Ringer buffer solution (1 g/mL) was used to carry out the experiments and the comparative analysis was performed using HPLC and LC-MS/MS methods. In vitro incubation, in situ closed-loop and in vivo blood sampling were used to measure the LWE metabolic profile along the digestive system. The incubation experiment showed that the LWE was basically stable in digestive juice. A comparative analysis presented the metabolic profile of each prototype and its corresponding metabolites then. Liver was the major metabolic organ for LWE, and the metabolism by the intestinal flora and gut wall was also an important part of the process. The MSM method was practical and could be a potential method to describe the metabolic routes of multiple components before absorption into the systemic blood stream. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Retinal blood vessel extraction using tunable bandpass filter and fuzzy conditional entropy.

PubMed

Sil Kar, Sudeshna; Maity, Santi P

2016-09-01

Extraction of blood vessels on retinal images plays a significant role for screening of different opthalmologic diseases. However, accurate extraction of the entire and individual type of vessel silhouette from the noisy images with poorly illuminated background is a complicated task. To this aim, an integrated system design platform is suggested in this work for vessel extraction using a sequential bandpass filter followed by fuzzy conditional entropy maximization on matched filter response. At first noise is eliminated from the image under consideration through curvelet based denoising. To include the fine details and the relatively less thick vessel structures, the image is passed through a bank of sequential bandpass filter structure optimized for contrast enhancement. Fuzzy conditional entropy on matched filter response is then maximized to find the set of multiple optimal thresholds to extract the different types of vessel silhouettes from the background. Differential Evolution algorithm is used to determine the optimal gain in bandpass filter and the combination of the fuzzy parameters. Using the multiple thresholds, retinal image is classified as the thick, the medium and the thin vessels including neovascularization. Performance evaluated on different publicly available retinal image databases shows that the proposed method is very efficient in identifying the diverse types of vessels. Proposed method is also efficient in extracting the abnormal and the thin blood vessels in pathological retinal images. The average values of true positive rate, false positive rate and accuracy offered by the method is 76.32%, 1.99% and 96.28%, respectively for the DRIVE database and 72.82%, 2.6% and 96.16%, respectively for the STARE database. Simulation results demonstrate that the proposed method outperforms the existing methods in detecting the various types of vessels and the neovascularization structures. The combination of curvelet transform and tunable bandpass filter is found to be very much effective in edge enhancement whereas fuzzy conditional entropy efficiently distinguishes vessels of different widths. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Automated Sample Preparation (ASP): Development of a Rapid Method to Sequentially Isolate Nucleic Acids and Protein from Any Sample Type by a Cartridge-Based System

DTIC Science & Technology

2013-11-27

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Cyclic nucleotide content of tobacco BY-2 cells.

PubMed

Richards, Helen; Das, Swadipa; Smith, Christopher J; Pereira, Louisa; Geisbrecht, Alan; Devitt, Nicola J; Games, David E; van Geyschem, Jan; Gareth Brenton, A; Newton, Russell P

2002-11-01

The cyclic nucleotide content of cultured tobacco bright yellow-2 (BY-2) cells was determined, after freeze-killing, perchlorate extraction and sequential chromatography, by radioimmunoassay. The identities of the putative cyclic nucleotides, adenosine 3',5'-cyclic monophosphate (cyclic AMP), guanosine 3',5'-cyclic monophosphate (cyclic GMP) and cytidine 3',5'-cyclic monophosphate (cyclic CMP) were unambiguously confirmed by tandem mass spectrometry. The potential of BY-2 cell cultures as a model system for future investigations of cyclic nucleotide function in higher plants is discussed.

Simultaneous determination of mequindox, quinocetone, and their major metabolites in chicken and pork by UPLC-MS/MS

USDA-ARS?s Scientific Manuscript database

This research presents a sensitive and confirmatory multi-residue method for mequindox (MEQ), quinocetone (QCT), and their 11 metabolites in chicken and pork samples. After extracted with acetonitrile-ethyl acetate, acidulated, and extracted again with ethyl acetate sequentially, each sample was pu...

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, PCB DETECTION TECHNOLOGY, HYBRIZYME DELFIA TM ASSAY

EPA Science Inventory

The DELFIA PCB Assay is a solid-phase time-resolved fluoroimmunoassay based on the sequential addition of sample extract and europium-labeled PCB tracer to a monoclonal antibody reagent specific for PCBs. In this assay, the antibody reagent and sample extract are added to a strip...

Fractionation of enzymatic hydrolysis lignin by sequential extraction for enhancing antioxidant performance.

PubMed

An, Liangliang; Wang, Guanhua; Jia, Hongyu; Liu, Cuiyun; Sui, Wenjie; Si, Chuanling

2017-06-01

The heterogeneity of lignin chemical structure and molecular weight results in the lignin inhomogeneous properties which also covers the antioxidant performance. In order to evaluate the effects of lignin heterogeneity on its antioxidant activity, four lignin fractions from enzymatic hydrolysis lignin were classified by sequential organic solvent extraction and further evaluated by DPPH (1,1-Diphenyl-2-Picrylhydrazyl) free radical scavenging capacity and reducing power analysis. The characterization including FTIR, 1 H NMR and GPC showed that the fractionation process could effectively separate lignin fractions with distinctly different molecular weight and weaken the heterogeneity of unfractionated lignin. The antioxidant performance comparison of lignin fractions indicated that the dichloromethane fraction (F1) with lowest molecular weight (4585g/mol) and highest total phenolics content (246.13mg GAE/g) exhibited the highest antioxidant activity whose value was close to commercial antioxidant BHT (butylated hydroxytoluene). Moreover, the relationship between the antioxidant activity and the structure of lignin was further discussed to elucidate the mechanism of antioxidant activity improvement of lignin fractionation. Consequently, this study suggested that the sequential extraction was an effective way to obtain relatively homogeneous enzymatic hydrolysis lignin fractions which showed the potential for the value-added antioxidant application. Copyright © 2017 Elsevier B.V. All rights reserved.

Sequential reconstruction of driving-forces from nonlinear nonstationary dynamics

NASA Astrophysics Data System (ADS)

Güntürkün, Ulaş

2010-07-01

This paper describes a functional analysis-based method for the estimation of driving-forces from nonlinear dynamic systems. The driving-forces account for the perturbation inputs induced by the external environment or the secular variations in the internal variables of the system. The proposed algorithm is applicable to the problems for which there is too little or no prior knowledge to build a rigorous mathematical model of the unknown dynamics. We derive the estimator conditioned on the differentiability of the unknown system’s mapping, and smoothness of the driving-force. The proposed algorithm is an adaptive sequential realization of the blind prediction error method, where the basic idea is to predict the observables, and retrieve the driving-force from the prediction error. Our realization of this idea is embodied by predicting the observables one-step into the future using a bank of echo state networks (ESN) in an online fashion, and then extracting the raw estimates from the prediction error and smoothing these estimates in two adaptive filtering stages. The adaptive nature of the algorithm enables to retrieve both slowly and rapidly varying driving-forces accurately, which are illustrated by simulations. Logistic and Moran-Ricker maps are studied in controlled experiments, exemplifying chaotic state and stochastic measurement models. The algorithm is also applied to the estimation of a driving-force from another nonlinear dynamic system that is stochastic in both state and measurement equations. The results are judged by the posterior Cramer-Rao lower bounds. The method is finally put into test on a real-world application; extracting sun’s magnetic flux from the sunspot time series.

A weight modification sequential method for VSC-MTDC power system state estimation

NASA Astrophysics Data System (ADS)

Yang, Xiaonan; Zhang, Hao; Li, Qiang; Guo, Ziming; Zhao, Kun; Li, Xinpeng; Han, Feng

2017-06-01

This paper presents an effective sequential approach based on weight modification for VSC-MTDC power system state estimation, called weight modification sequential method. The proposed approach simplifies the AC/DC system state estimation algorithm through modifying the weight of state quantity to keep the matrix dimension constant. The weight modification sequential method can also make the VSC-MTDC system state estimation calculation results more ccurate and increase the speed of calculation. The effectiveness of the proposed weight modification sequential method is demonstrated and validated in modified IEEE 14 bus system.

Compaction Kinetics on Single DNAs: Purified Nucleosome Reconstitution Systems versus Crude Extract

PubMed Central

Wagner, Gaudeline; Bancaud, Aurélien; Quivy, Jean-Pierre; Clapier, Cédric; Almouzni, Geneviève; Viovy, Jean-Louis

2005-01-01

Kinetics of compaction on single DNA molecules are studied by fluorescence videomicroscopy in the presence of 1), Xenopus egg extracts and 2), purified nucleosome reconstitution systems using a combination of histones with either the histone chaperone Nucleosome Assembly Protein (NAP-1) or negatively charged macromolecules such as polyglutamic acid and RNA. The comparison shows that the compaction rates can differ by a factor of up to 1000 for the same amount of histones, depending on the system used and on the presence of histone tails, which can be subjected to post-translational modifications. Reactions with purified reconstitution systems follow a slow and sequential mechanism, compatible with the deposition of one (H3-H4)2 tetramer followed by two (H2A-H2B) dimers. Addition of the histone chaperone NAP-1 increases both the rate of the reaction and the packing ratio of the final product. These stimulatory effects cannot be obtained with polyglutamic acid or RNA, suggesting that yNAP-1 impact on the reaction cannot simply be explained in terms of charge screening. Faster compaction kinetics and higher packing ratios are reproducibly reached with extracts, indicating a role of additional components present in this system. Data are discussed and models proposed to account for the kinetics obtained in our single-molecule assay. PMID:16100259

Distribution and uptake dynamics of mercury in leaves of common deciduous tree species in Minnesota, U.S.A.

Treesearch

Aicam Laacouri; Edward A. Nater; Randall K. Kolka

2013-01-01

A sequential extraction technique for compartmentalizing mercury (Hg) in leaves was developed based on a water extraction of Hg from the leaf surface followed by a solvent extraction of the cuticle. The bulk of leaf Hg was found in the tissue compartment (90-96%) with lesser amounts in the surface and cuticle compartments. Total leaf concentrations of Hg varied among...

Erythrocyte antioxidant protection of rose hips (Rosa spp.).

PubMed

Widén, C; Ekholm, A; Coleman, M D; Renvert, S; Rumpunen, K

2012-01-01

Rose hips are popular in health promoting products as the fruits contain high content of bioactive compounds. The aim of this study was to investigate whether health benefits are attributable to ascorbic acid, phenols, or other rose-hip-derived compounds. Freeze-dried powder of rose hips was preextracted with metaphosphoric acid and the sample was then sequentially eluted on a C(18) column. The degree of amelioration of oxidative damage was determined in an erythrocyte in vitro bioassay by comparing the effects of a reducing agent on erythrocytes alone or on erythrocytes pretreated with berry extracts. The maximum protection against oxidative stress, 59.4 ± 4.0% (mean ± standard deviation), was achieved when incubating the cells with the first eluted meta-phosphoric extract. Removal of ascorbic acid from this extract increased the protection against oxidative stress to 67.9 ± 1.9%. The protection from the 20% and 100% methanol extracts was 20.8 ± 8.2% and 5.0 ± 3.2%, respectively. Antioxidant uptake was confirmed by measurement of catechin by HPLC-ESI-MS in the 20% methanol extract. The fact that all sequentially eluted extracts studied contributed to protective effects on the erythrocytes indicates that rose hips contain a promising level of clinically relevant antioxidant protection.

Sequential microwave superheated water extraction of mannans from spent coffee grounds.

PubMed

Passos, Cláudia P; Moreira, Ana S P; Domingues, M Rosário M; Evtuguin, Dmitry V; Coimbra, Manuel A

2014-03-15

The feasibility of using sequential microwave superheated water extraction (MAE) for the recovery of mannans from spent coffee grounds (SCG) was studied. Due to the high contents of mannose still present in the SCG residue left after two consecutive MAE, the unextracted material was re-suspended in water and submitted to a third microwave irradiation (MAE3) at 200 °C for 3 min. With MAE3, mannose recovery achieved 48%, increasing to 56% by MAE4, and reaching a maximum of 69% with MAE5. Glycosidic-linkage analysis showed that in MAE3 mainly galactomannans were recovered, while debranched galactomannans were recovered with MAE4 and MAE5. With increasing the number of extractions, the average degree of polymerization of the mannans decreased, as observed by size-exclusion chromatography and by methylation analysis. Scanning electron microscopy images showed a decrease on cell walls thickness. After final MAE5, the remaining un-extracted insoluble material, representing 22% of the initial SCG, was composed mainly by cellulose (84%). Copyright © 2013 Elsevier Ltd. All rights reserved.

Heavy metal extractable forms in sludge from wastewater treatment plants.

PubMed

Alvarez, E Alonso; Mochón, M Callejón; Jiménez Sánchez, J C; Ternero Rodríguez, M

2002-05-01

The analysis of heavy metals is a very important task to assess the potential environmental and health risk associated with the sludge coming from wastewater treatment plants (WWTPs). However, it is widely accepted that the determination of total elements does not give an accurate estimation of the potential environmental impact. So, it is necessary to apply sequential extraction techniques to obtain a suitable information about their bioavailability or toxicity. In this paper, a sequential extraction scheme according to the BCR's guidelines was applied to sludge samples collected from each sludge treatment step of five municipal activated sludge plants. Al. Cd, Co, Cu, Cr, Fe, Mn, Hg, Mo, Ni, Pb, Ti and Zn were determined in the sludge extracts by inductively coupled plasma atomic emission spectrometry. In relation to current international legislation for the use of sludge for agricultural purposes none of metal concentrations exceeded maximum permitted levels. In most of the metal elements under considerations, results showed a clear rise along the sludge treatment in the proportion of two less-available fractions (oxidizable metal and residual metal).

Extraction of rare earth elements from a contaminated cropland soil using nitric acid, citric acid, and EDTA.

PubMed

Tang, Hailong; Shuai, Weitao; Wang, Xiaojing; Liu, Yangsheng

2017-08-01

Rare earth elements (REEs) contamination to the surrounding soil has increased the concerns of health risk to the local residents. Soil washing was first attempted in our study to remediate REEs-contaminated cropland soil using nitric acid, citric acid, and ethylene diamine tetraacetic acid (EDTA) for soil decontamination and possible recovery of REEs. The extraction time, washing agent concentration, and pH value of the washing solution were optimized. The sequential extraction analysis proposed by Tessier was adopted to study the speciation changes of the REEs before and after soil washing. The extract containing citric acid was dried to obtain solid for the X-ray fluorescence (XRF) analysis. The results revealed that the optimal extraction time was 72 h, and the REEs extraction efficiency increased as the agent concentration increased from 0.01 to 0.1 mol/L. EDTA was efficient to extract REEs over a wide range of pH values, while citric acid was around pH 6.0. Under optimized conditions, the average extraction efficiencies of the major REEs in the contaminated soil were 70.96%, 64.38%, and 62.12% by EDTA, nitric acid, and citric acid, respectively. The sequential extraction analyses revealed that most soil-bounded REEs were mobilized or extracted except for those in the residual fraction. Under a comprehensive consideration of the extraction efficiency and the environmental impact, citric acid was recommended as the most suitable agent for extraction of the REEs from the contaminated cropland soils. The XRF analysis revealed that Mn, Al, Si, Pb, Fe, and REEs were the major elements in the extract indicating a possibile recovery of the REEs.

Sequential healing at implants installed immediately into extraction sockets. An experimental study in dogs.

PubMed

Mainetti, Tomaso; Lang, Niklaus P; Bengazi, Franco; Favero, Vittorio; Soto Cantero, Luis; Botticelli, Daniele

2016-01-01

To compare the sequential healing at implants installed in a healed alveolar bony ridge or immediately after tooth extraction without functional load. In the mandible of 12 dogs, the mesial roots of the first molars were endodontically treated, the tooth hemisected, and the distal roots extracted. After 3 months, the mesial roots of the fourth premolars were endodontically treated, the tooth hemisected, and the distal roots extracted in one side of the mandible. Implants were placed immediately into extraction sockets (IPIES) of the fourth premolar and in the healed sites in the molar regions. Healing abutments were placed, and the flaps were sutured to allow a non-submerged healing. The time of surgery and of sacrifices were planned in such a way to obtain biopsies representing the healing after 1 and 2 weeks and 1 and 3 months, respectively. Ground sections were prepared for histological evaluation of tissues components on the implant surface and the coronal termination level of osseointegration (M-B). New bone apposition on the implant surface was slightly higher at the healed compared to the IPIES sites, being 7.4% and 4.1% after 1 week, and 67.3% and 65.3% after 3 months, respectively. Old bone was progressively resorbed, from 27.0% and 21.9% after 1 week, to 2.5% and 2.0% after 3 months, at healed and IPIES sites, respectively. M-B was 1.4 mm and 2.6 mm after 1 week, 1.2 mm and 1.2 mm after 3 months, at healed and IPIES sites, respectively. Similar patterns of sequential osseointegration were found at implants installed in healed alveolar bone or in alveolar sockets immediately after tooth extraction. The coronal termination level of osseointegration, that was different after 1 week, was found similar at the 3-month observation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Binding characteristics of Cu2+ to natural humic acid fractions sequentially extracted from the lake sediments.

PubMed

He, En; Lü, Changwei; He, Jiang; Zhao, Boyi; Wang, Jinghua; Zhang, Ruiqing; Ding, Tao

2016-11-01

Humic acids (HAs) determine the distribution, toxicity, bioavailability, and ultimate fate of heavy metals in the environment. In this work, ten HA fractions (F1-F10) were used as adsorbent, which were sequentially extracted from natural sediments of Lake Wuliangsuhai, to investigate the binding characteristics of Cu 2+ to HA. On the basis of the characterization results, differences were found between the ten extracted HA fractions responding to their elemental compositions and acidic functional groups. The characterization results reveal that the responses of ten extracted HA fractions to their elemental compositions and acidic functional groups were different. The O/C and (O + N)/C ratio of F1-F8 approximately ranged from 0.66 to 0.53 and from 0.72 to 0.61, respectively; the measured results showed that the contents of phenolic groups and carboxyl groups decreased from 4.46 to 2.60 mmol/g and 1.60 to 0.58 mmol/g, respectively. The binding characteristics of Cu 2+ to the ten HA fractions were well modeled by the bi-Langmuir model; the binding behavior of Cu 2+ to all the ten HA fractions were strongly impacted by pH and ionic strength. The FTIR and SEM-EDX image of HA fractions (pre- and post-adsorption) revealed that carboxyl and phenolic groups were responsible for the Cu 2+ sorption on the ten sequentially extracted HA fractions process, which is the same with the analysis of the ligand binding and bi-Langmuir models Accordingly, the adsorption capacity of the former HA fractions on Cu 2+ were higher than the latter ones, which may be attributed to the difference of carboxyl and phenolic group contents between the former and latter extracted HA fractions. Additionally, the functional groups with N and S should not be neglected. This work is hopeful to understand the environmental effect of humic substances, environmental geochemical behavior, and bioavailability of heavy metals in lakes.

The sequential structure of brain activation predicts skill.

PubMed

Anderson, John R; Bothell, Daniel; Fincham, Jon M; Moon, Jungaa

2016-01-29

In an fMRI study, participants were trained to play a complex video game. They were scanned early and then again after substantial practice. While better players showed greater activation in one region (right dorsal striatum) their relative skill was better diagnosed by considering the sequential structure of whole brain activation. Using a cognitive model that played this game, we extracted a characterization of the mental states that are involved in playing a game and the statistical structure of the transitions among these states. There was a strong correspondence between this measure of sequential structure and the skill of different players. Using multi-voxel pattern analysis, it was possible to recognize, with relatively high accuracy, the cognitive states participants were in during particular scans. We used the sequential structure of these activation-recognized states to predict the skill of individual players. These findings indicate that important features about information-processing strategies can be identified from a model-based analysis of the sequential structure of brain activation. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Radiator-Enhanced Geothermal System

NASA Astrophysics Data System (ADS)

Hilpert, M.; Marsh, B. D.; Geiser, P.

2015-12-01

Standard Enhanced Geothermal Systems (EGS) have repeatedly been hobbled by the inability of rock to conductively transfer heat at rates sufficient to re-supply heat extracted convectively via artificially made fracture systems. At the root of this imbalance is the basic magnitude of thermal diffusivity for most rocks, which severely hampers heat flow once the cooled halos about fractures reach ~0.1 m or greater. This inefficiency is exacerbated by the standard EGS design of mainly horizontally constructed fracture systems with inflow and outflow access at the margins of the fracture network. We introduced an alternative system whereby the heat exchanger mimics a conventional radiator in an internal combustion engine, which we call a Radiator-EGS (i.e., RAD-EGS). The heat exchanger is built vertically with cool water entering the base and hot water extracted at the top. The RAD-EGS itself consists of a family of vertical vanes produced through sequential horizontal drilling and permeability stimulation through propellant fracking. The manufactured fracture zones share the orientation of the natural transmissive fracture system. As below about 700 m, S1 is vertical and the average strike of transmissive fractures parallels SHmax, creating vertical fractures that include S1 and SHmax requires drilling stacked laterals parallel to SHmax. The RAD-EGS is also based on the observation that the longevity of natural hydrothermal systems depends on thermal recharge through heat convection but not heat conduction. In this paper, we present numerical simulations that examine the effects of the depths of the injector and extraction wells, vane size, coolant flow rate, the natural crustal geothermal gradient, and natural regional background flow on geothermal energy extraction.

Bacterial diversity in the active stage of a bioremediation system for mineral oil hydrocarbon-contaminated soils.

PubMed

Popp, Nicole; Schlömann, Michael; Mau, Margit

2006-11-01

Soils contaminated with mineral oil hydrocarbons are often cleaned in off-site bioremediation systems. In order to find out which bacteria are active during the degradation phase in such systems, the diversity of the active microflora in a degrading soil remediation system was investigated by small-subunit (SSU) rRNA analysis. Two sequential RNA extracts from one soil sample were generated by a procedure incorporating bead beating. Both extracts were analysed separately by generating individual SSU rDNA clone libraries from cDNA of the two extracts. The sequencing results showed moderate diversity. The two clone libraries were dominated by Gammaproteobacteria, especially Pseudomonas spp. Alphaproteobacteria and Betaproteobacteria were two other large groups in the clone libraries. Actinobacteria, Firmicutes, Bacteroidetes and Epsilonproteobacteria were detected in lower numbers. The obtained sequences were predominantly related to genera for which cultivated representatives have been described, but were often clustered together in the phylogenetic tree, and the sequences that were most similar were originally obtained from soils and not from pure cultures. Most of the dominant genera in the clone libraries, e.g. Pseudomonas, Acinetobacter, Sphingomonas, Acidovorax and Thiobacillus, had already been detected in (mineral oil hydrocarbon) contaminated environmental samples. The occurrence of the genera Zymomonas and Rhodoferax was novel in mineral oil hydrocarbon-contaminated soil.

Mining local climate data to assess spatiotemporal dengue fever epidemic patterns in French Guiana

PubMed Central

Flamand, Claude; Fabregue, Mickael; Bringay, Sandra; Ardillon, Vanessa; Quénel, Philippe; Desenclos, Jean-Claude; Teisseire, Maguelonne

2014-01-01

Objective To identify local meteorological drivers of dengue fever in French Guiana, we applied an original data mining method to the available epidemiological and climatic data. Through this work, we also assessed the contribution of the data mining method to the understanding of factors associated with the dissemination of infectious diseases and their spatiotemporal spread. Methods We applied contextual sequential pattern extraction techniques to epidemiological and meteorological data to identify the most significant climatic factors for dengue fever, and we investigated the relevance of the extracted patterns for the early warning of dengue outbreaks in French Guiana. Results The maximum temperature, minimum relative humidity, global brilliance, and cumulative rainfall were identified as determinants of dengue outbreaks, and the precise intervals of their values and variations were quantified according to the epidemiologic context. The strongest significant correlations were observed between dengue incidence and meteorological drivers after a 4–6-week lag. Discussion We demonstrated the use of contextual sequential patterns to better understand the determinants of the spatiotemporal spread of dengue fever in French Guiana. Future work should integrate additional variables and explore the notion of neighborhood for extracting sequential patterns. Conclusions Dengue fever remains a major public health issue in French Guiana. The development of new methods to identify such specific characteristics becomes crucial in order to better understand and control spatiotemporal transmission. PMID:24549761

Identification and Characterization of Cell Wall Proteins of a Toxic Dinoflagellate Alexandrium catenella Using 2-D DIGE and MALDI TOF-TOF Mass Spectrometry

PubMed Central

Wang, Da-Zhi; Dong, Hong-Po; Li, Cheng; Xie, Zhang-Xian; Lin, Lin; Hong, Hua-Sheng

2011-01-01

The cell wall is an important subcellular component of dinoflagellate cells with regard to various aspects of cell surface-associated ecophysiology, but the full range of cell wall proteins (CWPs) and their functions remain to be elucidated. This study identified and characterized CWPs of a toxic dinoflagellate, Alexandrium catenella, using a combination of 2D fluorescence difference gel electrophoresis (DIGE) and MALDI TOF-TOF mass spectrometry approaches. Using sequential extraction and temperature shock methods, sequentially extracted CWPs and protoplast proteins, respectively, were separated from A. catenella. From the comparison between sequentially extracted CWPs labeled with Cy3 and protoplast proteins labeled with Cy5, 120 CWPs were confidently identified in the 2D DIGE gel. These proteins gave positive identification of protein orthologues in the protein database using de novo sequence analysis and homology-based search. The majority of the prominent CWPs identified were hypothetical or putative proteins with unknown function or no annotation, while cell wall modification enzymes, cell wall structural proteins, transporter/binding proteins, and signaling and defense proteins were tentatively identified in agreement with the expected role of the extracellular matrix in cell physiology. This work represents the first attempt to investigate dinoflagellate CWPs and provides a potential tool for future comprehensive characterization of dinoflagellate CWPs and elucidation of their physiological functions. PMID:21904561

Spiroketalcarminic Acid, a Novel Minor Anthraquinone Pigment in Cochineal Extract Used in Food Additives.

PubMed

Ito, Yusai; Harikai, Naoki; Ishizuki, Kyoko; Shinomiya, Kazufusa; Sugimoto, Naoki; Akiyama, Hiroshi

2017-09-01

Cochineal extract prepared from the scale insect Dactylopus coccus (American cochineal) has been used as a natural red dye for food, cosmetics, and pharmaceuticals. The major pigment in cochineal extract is carminic acid (CA), an anthraquinone glucoside, and several minor pigments have been previously reported. Our investigation aimed at establishing the safety of cochineal dye products using ultra performance liquid chromatography-photo diode array-electrospray ionization-time of flight (UPLC-PDA-ESI-TOF)/MS found an unknown minor pigment, spiroketalcarminic acid (1), in three commercial cochineal extract samples; cochineal extract used in food additives, carmine that is an aluminum salt of cochineal extract used as natural dye, and a research reagent of CA. The purification of 1 from cochineal extract involved sequential chromatographic techniques, including preparative reversed-phase HPLC. Two dimensional (2D)-NMR and mass analyses established the structure of 1 to be a novel anthraquinone with an unusual 6,5-spiroketal system instead of the C-glucosyl moiety of CA. The absolute stereochemistry of the spiroketal moiety in 1 was determined by nuclear Overhauser effect spectroscopy (NOESY) correlations and optical rotation. No data corresponding to 1 had previously been reported for extracts of dried cochineal insects and traditional art products dyed with cochineal extract, indicating that 1 is likely produced during the preparation of commercial cochineal extract.

Decoding of finger trajectory from ECoG using deep learning.

PubMed

Xie, Ziqian; Schwartz, Odelia; Prasad, Abhishek

2018-06-01

Conventional decoding pipeline for brain-machine interfaces (BMIs) consists of chained different stages of feature extraction, time-frequency analysis and statistical learning models. Each of these stages uses a different algorithm trained in a sequential manner, which makes it difficult to make the whole system adaptive. The goal was to create an adaptive online system with a single objective function and a single learning algorithm so that the whole system can be trained in parallel to increase the decoding performance. Here, we used deep neural networks consisting of convolutional neural networks (CNN) and a special kind of recurrent neural network (RNN) called long short term memory (LSTM) to address these needs. We used electrocorticography (ECoG) data collected by Kubanek et al. The task consisted of individual finger flexions upon a visual cue. Our model combined a hierarchical feature extractor CNN and a RNN that was able to process sequential data and recognize temporal dynamics in the neural data. CNN was used as the feature extractor and LSTM was used as the regression algorithm to capture the temporal dynamics of the signal. We predicted the finger trajectory using ECoG signals and compared results for the least angle regression (LARS), CNN-LSTM, random forest, LSTM model (LSTM_HC, for using hard-coded features) and a decoding pipeline consisting of band-pass filtering, energy extraction, feature selection and linear regression. The results showed that the deep learning models performed better than the commonly used linear model. The deep learning models not only gave smoother and more realistic trajectories but also learned the transition between movement and rest state. This study demonstrated a decoding network for BMI that involved a convolutional and recurrent neural network model. It integrated the feature extraction pipeline into the convolution and pooling layer and used LSTM layer to capture the state transitions. The discussed network eliminated the need to separately train the model at each step in the decoding pipeline. The whole system can be jointly optimized using stochastic gradient descent and is capable of online learning.

Decoding of finger trajectory from ECoG using deep learning

NASA Astrophysics Data System (ADS)

Xie, Ziqian; Schwartz, Odelia; Prasad, Abhishek

2018-06-01

Objective. Conventional decoding pipeline for brain-machine interfaces (BMIs) consists of chained different stages of feature extraction, time-frequency analysis and statistical learning models. Each of these stages uses a different algorithm trained in a sequential manner, which makes it difficult to make the whole system adaptive. The goal was to create an adaptive online system with a single objective function and a single learning algorithm so that the whole system can be trained in parallel to increase the decoding performance. Here, we used deep neural networks consisting of convolutional neural networks (CNN) and a special kind of recurrent neural network (RNN) called long short term memory (LSTM) to address these needs. Approach. We used electrocorticography (ECoG) data collected by Kubanek et al. The task consisted of individual finger flexions upon a visual cue. Our model combined a hierarchical feature extractor CNN and a RNN that was able to process sequential data and recognize temporal dynamics in the neural data. CNN was used as the feature extractor and LSTM was used as the regression algorithm to capture the temporal dynamics of the signal. Main results. We predicted the finger trajectory using ECoG signals and compared results for the least angle regression (LARS), CNN-LSTM, random forest, LSTM model (LSTM_HC, for using hard-coded features) and a decoding pipeline consisting of band-pass filtering, energy extraction, feature selection and linear regression. The results showed that the deep learning models performed better than the commonly used linear model. The deep learning models not only gave smoother and more realistic trajectories but also learned the transition between movement and rest state. Significance. This study demonstrated a decoding network for BMI that involved a convolutional and recurrent neural network model. It integrated the feature extraction pipeline into the convolution and pooling layer and used LSTM layer to capture the state transitions. The discussed network eliminated the need to separately train the model at each step in the decoding pipeline. The whole system can be jointly optimized using stochastic gradient descent and is capable of online learning.

Vaccine adverse event text mining system for extracting features from vaccine safety reports.

PubMed

Botsis, Taxiarchis; Buttolph, Thomas; Nguyen, Michael D; Winiecki, Scott; Woo, Emily Jane; Ball, Robert

2012-01-01

To develop and evaluate a text mining system for extracting key clinical features from vaccine adverse event reporting system (VAERS) narratives to aid in the automated review of adverse event reports. Based upon clinical significance to VAERS reviewing physicians, we defined the primary (diagnosis and cause of death) and secondary features (eg, symptoms) for extraction. We built a novel vaccine adverse event text mining (VaeTM) system based on a semantic text mining strategy. The performance of VaeTM was evaluated using a total of 300 VAERS reports in three sequential evaluations of 100 reports each. Moreover, we evaluated the VaeTM contribution to case classification; an information retrieval-based approach was used for the identification of anaphylaxis cases in a set of reports and was compared with two other methods: a dedicated text classifier and an online tool. The performance metrics of VaeTM were text mining metrics: recall, precision and F-measure. We also conducted a qualitative difference analysis and calculated sensitivity and specificity for classification of anaphylaxis cases based on the above three approaches. VaeTM performed best in extracting diagnosis, second level diagnosis, drug, vaccine, and lot number features (lenient F-measure in the third evaluation: 0.897, 0.817, 0.858, 0.874, and 0.914, respectively). In terms of case classification, high sensitivity was achieved (83.1%); this was equal and better compared to the text classifier (83.1%) and the online tool (40.7%), respectively. Our VaeTM implementation of a semantic text mining strategy shows promise in providing accurate and efficient extraction of key features from VAERS narratives.

Distortion product otoacoustic emissions: comparison of sequential vs. simultaneous presentation of primary tones.

PubMed

Kumar, U Ajith; Maruthy, Sandeep; Chandrakant, Vishwakarma

2009-03-01

Distortion product otoacoustic emissions are one form of evoked otoacoustic emissions. DPOAEs provide the frequency specific information about the hearing status in mid and high frequency regions. But in most screening protocols TEOAEs are preferred as it requires less time compared to DPOAE. This is because, in DPOAE each stimulus is presented one after the other and responses are analyzed. Grason and Stadler Incorporation 60 (GSI-60) offer simultaneous presentation of four sets of primary tones at a time and checks for the DPOAE. In this mode of presentation, all the pairs are presented at a time and following that response is extracted separately whereas, in sequential mode primaries are presented in orderly fashion one after the other. In this article simultaneous and sequential protocols were used to compare the Distortion product otoacoustic emission amplitude, noise floor and administration time in individuals with normal hearing and mild sensori-neural (SN) hearing loss. In simultaneous protocols four sets of primary tones (i.e. 8 tones) were presented together whereas, in sequential presentation mode one set of primary tones was presented each time. Simultaneous protocol was completed in less than half the time required for the completion of sequential protocol. Two techniques yielded similar results at frequencies above 1000 Hz only in normal hearing group. In SN hearing loss group simultaneous presentation yielded signifi cantly higher noise floors and distortion product amplitudes. This result challenges the use of simultaneous presentation technique in neonatal hearing screening programmes and on other pathologies. This discrepancy between two protocols may be due to some changes in biomechanical process in the cochlear and/or due to higher distortion/noise produced by the system during the simultaneous presentation mode.

Information Management: Publishing and Printing: Army Publishing: Action Officers Guide

DTIC Science & Technology

2002-04-30

types of lists: ordered (such as numerical, alphabetical, or sequential ), bulleted, or dashed. (4) Extracted material in an appendix must be identified...provide supporting, expanded, or sequential doctrinal manuals within a functional field (this number group must not exceed 3 digits). Table 13–2...rubup, opaquing, lineup , and register, and so forth 1,2 190 DA PAM 25–40 • 30 April 2002 Table J–5 Camera, platemaking, and related equipment—Continued

Classification of epileptic EEG signals based on simple random sampling and sequential feature selection.

PubMed

Ghayab, Hadi Ratham Al; Li, Yan; Abdulla, Shahab; Diykh, Mohammed; Wan, Xiangkui

2016-06-01

Electroencephalogram (EEG) signals are used broadly in the medical fields. The main applications of EEG signals are the diagnosis and treatment of diseases such as epilepsy, Alzheimer, sleep problems and so on. This paper presents a new method which extracts and selects features from multi-channel EEG signals. This research focuses on three main points. Firstly, simple random sampling (SRS) technique is used to extract features from the time domain of EEG signals. Secondly, the sequential feature selection (SFS) algorithm is applied to select the key features and to reduce the dimensionality of the data. Finally, the selected features are forwarded to a least square support vector machine (LS_SVM) classifier to classify the EEG signals. The LS_SVM classifier classified the features which are extracted and selected from the SRS and the SFS. The experimental results show that the method achieves 99.90, 99.80 and 100 % for classification accuracy, sensitivity and specificity, respectively.

Determination and partitioning of metals in sediments along the Suez Canal by sequential extraction

NASA Astrophysics Data System (ADS)

Abd El-Azim, H.; El-Moselhy, Kh. M.

2005-06-01

The application of sequential extraction technique was used to determine the chemical association of heavy metals in five different chemical phases (exchangeable F1, bound to carbonate F2, bound to Fe-Mn oxides F3, bound to organic matter F4 and residual F5) for sediment samples collected from the Suez Canal. From the obtained data, it can be seen that the surplus of metal contaminants introduced into the sediment from sources usually exists in relatively unstable chemical forms. A high proportion of the studied metals remained in the residual fraction. Most of remaining portion of metals was bound to ferromanganese oxides fraction. The low concentrations of metals in the exchangeable fraction indicated that the sediments of Suez Canal were relatively unpolluted.

Instant controlled pressure drop technology and ultrasound assisted extraction for sequential extraction of essential oil and antioxidants.

PubMed

Allaf, Tamara; Tomao, Valérie; Ruiz, Karine; Chemat, Farid

2013-01-01

The instant controlled pressure drop (DIC) technology enabled both the extraction of essential oil and the expansion of the matrix itself which improved solvent extraction. The sequential use of DIC and Ultrasound Assisted Extraction (UAE) triggered complementary actions materialized by supplementary effects. We visualized these combination impacts by comparing them to standard techniques: Hydrodistillation (HD) and Solvent Extraction (SE). First, the extraction of orange peel Essential Oils (EO) was achieved by HD during 4h and DIC process (after optimization) during 2 min; EO yields was 1.97 mg/g dry material (dm) with HD compared to 16.57 mg/g d m with DIC. Second, the solid residue was recovered to extract antioxidant compounds (naringin and hesperidin) by SE and UAE. Scanning electron microscope showed that after HD the recovered solid shriveled as opposite to DIC treatment which expanded the product structure. HPLC analyses showed that the best kinetics and yields of naringin and hesperidin extraction was when DIC and UAE are combined. Indeed, after 1h of extraction, DIC treated orange peels with UAE were 0.825 ± 1.6 × 10(-2)g/g of dry material (dm) for hesperidin and 6.45 × 10(-2) ± 2.3 × 10(-4)g/g d m for naringin compared to 0.64 ± 2.7 × 10(-2)g/g of dry material (dm) and 5.7 × 10(-2) ± 1.6 × 10(-3)g/g d m, respectively with SE. By combining DIC to UAE, it was possible to enhance kinetics and yields of antioxidant extraction. Copyright © 2012 Elsevier B.V. All rights reserved.

Selective determination of heavy metals (Cd, Pb, Cr) speciation forms from hortic anthrosols

NASA Astrophysics Data System (ADS)

Bulgariu, Dumitru; Bulgariu, Laura; Filipov, Feodor; Astefanei, Dan; Stoleru, Vasile

2010-05-01

In soils from glass houses, the speciation and inter-phases distribution processes of heavy metals have a particular dynamic, different in comparison with those from non-protected soils. The predominant distribution forms of heavy metals in such soils types are: complexes with low mass organic molecules, organic-mineral complexes, complexes with inorganic ligands (hydroxide-complexes, carbonate-complexes, sulphate-complexes, etc.) and basic salts. All of these have high stabilities in conditions of soils from glass houses, and in consequence, the separation and determination of speciation forms (which is directly connected with biodisponibility of heavy metals) by usual methods id very difficult and has a high uncertain degree. In this study is presented an original method for the selective separation and differentiation of speciation forms of heavy metals from glass houses soils, which is based by the combination of solid-liquid sequential extraction (SPE) with the extraction in aqueous polymer-inorganic salt two-phase systems (ABS). The soil samples used for this study have been sampled from three different locations (glass houses from Iasi, Barlad and Bacau - Romania) where the vegetables cultivation have been performed by three different technologies. In this way was estimated the applicability and the analytical limits of method proposed by as, in function of the chemical-mineralogical and physical-chemical characteristics of soils. As heavy metals have been studied cadmium, lead and chromium, all being known for their high toxicity. The procedure used for the selective separation and differentiation of speciation forms of heavy metals from glass houses soils has two main steps: (i) non-destructive separation of chemical-mineralogical associations and aggregates from soils samples - for this the separation method with heavy liquids (bromophorme) and isodynamic magnetic method have been used; (ii) sequential extraction of heavy metals from soil fractions separated in the first step, by using combined SPE-ABS procedure. For the preparation of combined extraction systems was used polyethylene glycol (with different molecular mass: 2000, 4000 and 8000). As phase-forming inorganic salts and as selective extracting agents we have used different usual inorganic reagents. The type and concentration of phase-forming salts have been selected in function of, both nature of extracted heavy metals and chemical-mineralogical characteristics of soil samples. The experimental parameters investigated in this study are: molecular mass of polyethylene glycol and the concentration of polymeric solutions, nature and concentration of phase-forming salts, nature and concentration of extracting agents, pH in extraction system phase, type of extracted heavy metals, type of speciation forms of heavy metals and their concentrations. All these factors can influence significantly the efficiency and the selectivity of separation process. The experimental results have indicate that the combined SPE-ABS extraction systems have better separation efficiency, in comparison with traditional SPE systems and ca realized a accurate discrimination between speciation forms of heavy metals from soils. Under these conditions, the estimation of inter-phases distribution and biodisponibility of heavy metals has a high precision. On the other hand, when the combined SPE-ABS systems are used, the concomitant extraction of the elements from the same geochemical association with studied heavy metals (inevitable phenomena in case of separation by SPE procedures) is significant diminished. This increases the separation selectivity and facilitated the more accurate determination of speciation forms concentration. By adequate selection of extraction conditions can be realized the selective separation of organic-mineral complexes, which will permit to perform detailed studies about the structure and chemical composition of these. Acknowledgments The authors would like to acknowledge the financial support from Romanian Ministry of Education and Research (Project PNCDI 2-D5 no. 51045/07 and project PNCDI 2 - D5 no. 52-141 / 2008).

Selective Separation and Determination of Heavy Metals (Cd, Pb, Cr) Speciation Forms from Hortic Antrosols

NASA Astrophysics Data System (ADS)

Bulgariu, D.; Bulgariu, L.

2009-04-01

The speciation, inter-phases distribution and biodisponibility of heavy metals in soils represent one of main problem of environmental geochemistry and agro-chemistry. This problem is very important in case of hortic antrosols (soils from glasshouses) for the elimination of agricultural products (fruits, vegetables) contamination with heavy metals. In soils from glass houses, the speciation and inter-phases distribution processes of heavy metals have a particular dynamic, different in comparison with those from non-protected soils. The predominant distribution forms of heavy metals in such soils types are: complexes with low mass organic molecules, organic-mineral complexes, complexes with inorganic ligands (hydroxide-complexes, carbonate-complexes, sulphate-complexes, etc.) and basic salts. All of these have high stabilities in conditions of soils from glass houses, and in consequence, the separation and determination of speciation forms (which is directly connected with biodisponibility of heavy metals) by usual methods id very difficult and has a high uncertain degree. In this study is presented an original method for the selective separation and differentiation of speciation forms of heavy metals from glass houses soils, which is based by the combination of solid-liquid sequential extraction (SPE) with the extraction in aqueous polymer-inorganic salt two-phase systems (ABS). The soil samples used for this study have been sampled from three different locations (glass houses from Iasi, Barlad and Bacau - Romania) where the vegetables cultivation have bee performed by three different technologies. In this way was estimated the applicability and the analytical limits of method proposed by as, in function of the chemical-mineralogical and physical-chemical characteristics of soils. As heavy metals have been studied cadmium, lead and chromium, all being known for their high toxicity. The procedure used for the selective separation and differentiation of speciation forms of heavy metals from glass houses soils has two main steps: (i) non-destructive separation of chemical-mineralogical associations and aggregates from soils samples - for this the separation method with heavy liquids (bromophorme) and isodynamic magnetic method have been used; (ii) sequential extraction of heavy metals from soil fractions separated in the first step, by using combined SPE-ABS procedure. For the preparation of combined extraction systems was used polyethylene glycol (with different molecular mass: 2000, 4000 and 8000). As phase-forming inorganic salts and as selective extracting agents we have used different usual inorganic reagents. The type and concentration of phase-forming salts have been selected in function of, both nature of extracted heavy metals and chemical-mineralogical characteristics of soil samples. The experimental parameters investigated in this study are: molecular mass of polyethylene glycol and the concentration of polymeric solutions, nature and concentration of phase-forming salts, nature and concentration of extracting agents, pH in extraction system phase, type of extracted heavy metals, type of speciation forms of heavy metals and their concentrations. All these factors can influence significantly the efficiency and the selectivity of separation process. The experimental results have indicate that the combined SPE-ABS extraction systems have better separation efficiency, in comparison with traditional SPE systems and ca realized a accurate discrimination between speciation forms of heavy metals from soils. Under these conditions, the estimation of inter-phases distribution and biodisponibility of heavy metals has a high precision. On the other hand, when the combined SPE-ABS systems are used, the concomitant extraction of the elements from the same geochemical association with studied heavy metals (inevitable phenomena in case of separation by SPE procedures) is significant diminished. This increases the separation selectivity and facilitated the more accurate determination of speciation forms concentration. By adequate selection of extraction conditions can be realized the selective separation of organic-mineral complexes, which will permit to perform detailed studies about the structure and chemical composition of these. Acknowledgments The authors would like to acknowledge the financial support from Romanian Ministry of Education and Research (Project PNCDI 2-D5 no. 51045/07).

Information extraction during simultaneous motion processing.

PubMed

Rideaux, Reuben; Edwards, Mark

2014-02-01

When confronted with multiple moving objects the visual system can process them in two stages: an initial stage in which a limited number of signals are processed in parallel (i.e. simultaneously) followed by a sequential stage. We previously demonstrated that during the simultaneous stage, observers could discriminate between presentations containing up to 5 vs. 6 spatially localized motion signals (Edwards & Rideaux, 2013). Here we investigate what information is actually extracted during the simultaneous stage and whether the simultaneous limit varies with the detail of information extracted. This was achieved by measuring the ability of observers to extract varied information from low detail, i.e. the number of signals presented, to high detail, i.e. the actual directions present and the direction of a specific element, during the simultaneous stage. The results indicate that the resolution of simultaneous processing varies as a function of the information which is extracted, i.e. as the information extraction becomes more detailed, from the number of moving elements to the direction of a specific element, the capacity to process multiple signals is reduced. Thus, when assigning a capacity to simultaneous motion processing, this must be qualified by designating the degree of information extraction. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Two new xanthones from Calophyllum nodusum (Guttiferae).

PubMed

Nasir, Nadiah Mad; Rahmani, Mawardi; Shaari, Khozirah; Ee, Gwendoline Cheng Lian; Go, Rusea; Kassim, Nur Kartinee; Muhamad, Siti Noor Kamilah; Iskandar, Mohd Johadi

2011-10-25

The air-dried powdered stem bark of Calophyllum nodusum (Guttiferea) collected from Sandakan (Sabah, Malaysia), was extracted sequentially with hexane, chloroform and methanol. The solvents were removed by rotary evaporator to give dark viscous extracts. Detailed and repeated chromatographic separation of the extracts lead to isolation of two new xanthones, identified as nodusuxanthone and trapezifolixanthone A. Other common terpenoids such as betulinic acid, lupeol, stigmasterol and friedelin were also isolated from the extracts and identified. The structures of the compounds were established by detailed spectral analysis and comparison with previously reported data.

Direct Estimation of Structure and Motion from Multiple Frames

DTIC Science & Technology

1990-03-01

sequential frames in an image sequence. As a consequence, the information that can be extracted from a single optical flow field is limited to a snapshot of...researchers have developed techniques that extract motion and structure inform.4tion without computation of the optical flow. Best known are the "direct...operated iteratively on a sequence of images to recover structure. It required feature extraction and matching. Broida and Chellappa [9] suggested the use of

Sequentially Integrated Optimization of the Conditions to Obtain a High-Protein and Low-Antinutritional Factors Protein Isolate from Edible Jatropha curcas Seed Cake.

PubMed

León-López, Liliana; Dávila-Ortiz, Gloria; Jiménez-Martínez, Cristian; Hernández-Sánchez, Humberto

2013-01-01

Jatropha curcas seed cake is a protein-rich byproduct of oil extraction which could be used to produce protein isolates. The purpose of this study was the optimization of the protein isolation process from the seed cake of an edible provenance of J. curcas by an alkaline extraction followed by isoelectric precipitation method via a sequentially integrated optimization approach. The influence of four different factors (solubilization pH, extraction temperature, NaCl addition, and precipitation pH) on the protein and antinutritional compounds content of the isolate was evaluated. The estimated optimal conditions were an extraction temperature of 20°C, a precipitation pH of 4, and an amount of NaCl in the extraction solution of 0.6 M for a predicted protein content of 93.3%. Under these conditions, it was possible to obtain experimentally a protein isolate with 93.21% of proteins, 316.5 mg 100 g(-1) of total phenolics, 2891.84 mg 100 g(-1) of phytates and 168 mg 100 g(-1) of saponins. The protein content of the this isolate was higher than the content reported by other authors.

Sequentially Integrated Optimization of the Conditions to Obtain a High-Protein and Low-Antinutritional Factors Protein Isolate from Edible Jatropha curcas Seed Cake

PubMed Central

León-López, Liliana; Dávila-Ortiz, Gloria; Jiménez-Martínez, Cristian; Hernández-Sánchez, Humberto

2013-01-01

Jatropha curcas seed cake is a protein-rich byproduct of oil extraction which could be used to produce protein isolates. The purpose of this study was the optimization of the protein isolation process from the seed cake of an edible provenance of J. curcas by an alkaline extraction followed by isoelectric precipitation method via a sequentially integrated optimization approach. The influence of four different factors (solubilization pH, extraction temperature, NaCl addition, and precipitation pH) on the protein and antinutritional compounds content of the isolate was evaluated. The estimated optimal conditions were an extraction temperature of 20°C, a precipitation pH of 4, and an amount of NaCl in the extraction solution of 0.6 M for a predicted protein content of 93.3%. Under these conditions, it was possible to obtain experimentally a protein isolate with 93.21% of proteins, 316.5 mg 100 g−1 of total phenolics, 2891.84 mg 100 g−1 of phytates and 168 mg 100 g−1 of saponins. The protein content of the this isolate was higher than the content reported by other authors. PMID:25937971

Sequential protein extraction as an efficient method for improved proteome coverage in larvae of Atlantic salmon (Salmo salar).

PubMed

Nuez-Ortín, Waldo G; Carter, Chris G; Nichols, Peter D; Wilson, Richard

2016-07-01

Understanding diet- and environmentally induced physiological changes in fish larvae is a major goal for the aquaculture industry. Proteomic analysis of whole fish larvae comprising multiple tissues offers considerable potential but is challenging due to the very large dynamic range of protein abundance. To extend the coverage of the larval phase of the Atlantic salmon (Salmo salar) proteome, we applied a two-step sequential extraction (SE) method, based on differential protein solubility, using a nondenaturing buffer containing 150 mM NaCl followed by a denaturing buffer containing 7 M urea and 2 M thiourea. Extracts prepared using SE and one-step direct extraction were characterized via label-free shotgun proteomics using nanoLC-MS/MS (LTQ-Orbitrap). SE partitioned the proteins into two fractions of approximately equal amounts, but with very distinct protein composition, leading to identification of ∼40% more proteins than direct extraction. This fractionation strategy enabled the most detailed characterization of the salmon larval proteome to date and provides a platform for greater understanding of physiological changes in whole fish larvae. The MS data are available via the ProteomeXchange Consortium PRIDE partner repository, dataset PXD003366. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A stacked sequential learning method for investigator name recognition from web-based medical articles

NASA Astrophysics Data System (ADS)

Zhang, Xiaoli; Zou, Jie; Le, Daniel X.; Thoma, George

2010-01-01

"Investigator Names" is a newly required field in MEDLINE citations. It consists of personal names listed as members of corporate organizations in an article. Extracting investigator names automatically is necessary because of the increasing volume of articles reporting collaborative biomedical research in which a large number of investigators participate. In this paper, we present an SVM-based stacked sequential learning method in a novel application - recognizing named entities such as the first and last names of investigators from online medical journal articles. Stacked sequential learning is a meta-learning algorithm which can boost any base learner. It exploits contextual information by adding the predicted labels of the surrounding tokens as features. We apply this method to tag words in text paragraphs containing investigator names, and demonstrate that stacked sequential learning improves the performance of a nonsequential base learner such as an SVM classifier.

Predictability of refraction following immediate sequential bilateral cataract surgery (ISBCS) performed under general anaesthesia.

PubMed

Guber, Ivo; Rémont, Laurent; Bergin, Ciara

2015-01-01

To evaluate the predictability of refraction following immediate sequential bilateral cataract surgery (ISBCS) performed under general anaesthesia. This is a retrospective review of all ISBCS performed at Kantonsspital Winterthur, Switzerland, between April 2000 and September 2013. The case notes of 250 patients were reviewed. Patients having full refraction reported (110 patients/220 eyes) were included. 210 (95 %) eyes had a straight forward phacoemulsification with posterior chamber intraocular lens implantation, seven eyes had a planned extracapsular cataract extraction (ECCE); three eyes had an intracapsular cataract extraction. Both eyes of 110 patients (64 women, 46 men) with a mean age of 79.0 years, standard deviation (SD) ±11.4 (range 26 to 97 years) were included. Median preoperative best corrected visual acuity (BCVA) was 0.5 LogMAR in the first eye, the interquartile range (IQR) was [0.4, 1.2]; 0.7 LogMAR in the second eye with IQR [0.4, 1.8]. At one month, the median BCVA was 0.2 LogMAR, IQR [0.1, 0.3] in the first eye, median BCVA was 0.1 LogMAR and IQR [0.0, 0.5] in the second eye. There were 3 eyes (3 %) that lost 3 lines or more in BCVA at one month (control vs. pre-operatively). In all three cases, poor visual acuity had been recorded pre-operatively (>1 LogMAR). Achieved refraction was within ±1.0 D of the target in 83 % of eyes. There were only 5 % (n = 6) of cases where if delayed sequential bilateral extraction had been performed could potentially intraocular lens (IOL) choice have been adjusted, in four of these cases, target refraction was within ±1.0 D in the second eye. ISBCS performed under general anaesthesia achieves target refraction in 83 % of eyes after consideration of complications, ocular co-morbidities and systemic restrictions. In the majority of cases where IOL power calculation could be considered, the achieved refraction of the second surgical eye was within ±1.0 D of intended refraction. This undermines the utility of IOL power adjustments in the second surgical eye.

Sorption of Cu(2+) on humic acids sequentially extracted from a sediment.

PubMed

Yang, Kun; Miao, Gangfen; Wu, Wenhao; Lin, Daohui; Pan, Bo; Wu, Fengchang; Xing, Baoshan

2015-11-01

In addition to the diverse properties of humic acids (HAs) extracted from different soils or sediments, chemical compositions, functional groups and structures of HAs extracted from a single soil or sediment could also be diverse and thus significantly affect sorption of heavy metals, which is a key process controlling the transfer, transformation and fate of heavy metals in the environment. In this study, we sequentially extracted four HA fractions from a single sediment and conducted the sorption experiments of Cu(2+) on these HA fractions. Our results showed that aromaticity and acidic group content of HA fraction decreased with increasing extraction. Earlier extracted HA fraction had higher sorption capacity and affinity for Cu(2+). There were two fractions of adsorbed Cu(2+) on HAs, i.e., ion exchanged fraction and surface bonded fraction, which can be captured mechanically by the bi-Langmuir model with good isotherm fitting. The ion exchanged fraction had larger sorption capacity but lower sorption affinity, compared with the surface bonded fraction. The dissociated carboxyl groups of HAs were responsible for both fractions of Cu(2+) sorption, due to the more Cu(2+) sorption on the earlier extracted HA fraction with more carboxyl groups and at higher pH. The intensive competition between H(+) and the exchangeable Cu(2+) could result in the decrease of ion exchanged capacity and affinity for Cu(2+) on HAs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sequential estimation and satellite data assimilation in meteorology and oceanography

NASA Technical Reports Server (NTRS)

Ghil, M.

1986-01-01

The role of dynamics in estimating the state of the atmosphere and ocean from incomplete and noisy data is discussed and the classical applications of four-dimensional data assimilation to large-scale atmospheric dynamics are presented. It is concluded that sequential updating of a forecast model with continuously incoming conventional and remote-sensing data is the most natural way of extracting the maximum amount of information from the imperfectly known dynamics, on the one hand, and the inaccurate and incomplete observations, on the other.

Sequential injection ionic liquid dispersive liquid-liquid microextraction for thallium preconcentration and determination with flame atomic absorption spectrometry.

PubMed

Anthemidis, Aristidis N; Ioannou, Kallirroy-Ioanna G

2012-08-01

A novel, automatic on-line sequential injection dispersive liquid-liquid microextraction (SI-DLLME) method, based on 1-hexyl-3-methylimidazolium hexafluorophosphate ([Hmim][PF(6)]) ionic liquid as an extractant solvent was developed and demonstrated for trace thallium determination by flame atomic absorption spectrometry. The ionic liquid was on-line fully dispersed into the aqueous solution in a continuous flow format while the TlBr(4)(-) complex was easily migrated into the fine droplets of the extractant due to the huge contact area of them with the aqueous phase. Furthermore, the extractant was simply retained onto the surface of polyurethane foam packed into a microcolumn. No specific conditions like low temperature are required for extractant isolation. All analytical parameters of the proposed method were investigated and optimized. For 15 mL of sample solution, an enhancement factor of 290, a detection limit of 0.86 μg L(-1) and a precision (RSD) of 2.7% at 20.0 μg L(-1) Tl(I) concentration level, was obtained. The developed method was evaluated by analyzing certified reference materials while good recoveries from environmental and biological samples proved that present method was competitive in practical applications.

Sequential Exposure of Bortezomib and Vorinostat is Synergistic in Multiple Myeloma Cells

PubMed Central

Nanavati, Charvi; Mager, Donald E.

2018-01-01

Purpose To examine the combination of bortezomib and vorinostat in multiple myeloma cells (U266) and xenografts, and to assess the nature of their potential interactions with semi-mechanistic pharmacodynamic models and biomarkers. Methods U266 proliferation was examined for a range of bortezomib and vorinostat exposure times and concentrations (alone and in combination). A non-competitive interaction model was used with interaction parameters that reflect the nature of drug interactions after simultaneous and sequential exposures. p21 and cleaved PARP were measured using immunoblotting to assess critical biomarker dynamics. For xenografts, data were extracted from literature and modeled with a PK/PD model with an interaction parameter. Results Estimated model parameters for simultaneous in vitro and xenograft treatments suggested additive drug effects. The sequence of bortezomib preincubation for 24 hours, followed by vorinostat for 24 hours, resulted in an estimated interaction term significantly less than 1, suggesting synergistic effects. p21 and cleaved PARP were also up-regulated the most in this sequence. Conclusions Semi-mechanistic pharmacodynamic modeling suggests synergistic pharmacodynamic interactions for the sequential administration of bortezomib followed by vorinostat. Increased p21 and cleaved PARP expression can potentially explain mechanisms of their enhanced effects, which require further PK/PD systems analysis to suggest an optimal dosing regimen. PMID:28101809

Biodiesel production from wet microalgae feedstock using sequential wet extraction/transesterification and direct transesterification processes.

PubMed

Chen, Ching-Lung; Huang, Chien-Chang; Ho, Kao-Chia; Hsiao, Ping-Xuan; Wu, Meng-Shan; Chang, Jo-Shu

2015-10-01

Although producing biodiesel from microalgae seems promising, there is still a lack of technology for the quick and cost-effective conversion of biodiesel from wet microalgae. This study was aimed to develop a novel microalgal biodiesel producing method, consisting of an open system of microwave disruption, partial dewatering (via combination of methanol treatment and low-speed centrifugation), oil extraction, and transesterification without the pre-removal of the co-solvent, using Chlamydomonas sp. JSC4 with 68.7 wt% water content as the feedstock. Direct transesterification with the disrupted wet microalgae was also conducted. The biomass content of the wet microalgae increased to 56.6 and 60.5 wt%, respectively, after microwave disruption and partial dewatering. About 96.2% oil recovery was achieved under the conditions of: extraction temperature, 45°C; hexane/methanol ratio, 3:1; extraction time, 80 min. Transesterification of the extracted oil reached 97.2% conversion within 15 min at 45°C and 6:1 solvent/methanol ratio with simultaneous Chlorophyll removal during the process. Nearly 100% biodiesel conversion was also obtained while conducting direct transesterification of the disrupted oil-bearing microalgal biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sequential extraction of chromium, molybdenum, and vanadium in basic oxygen furnace slags.

PubMed

Spanka, Marina; Mansfeldt, Tim; Bialucha, Ruth

2018-06-02

Basic oxygen furnace slags (BOS) are by-products of basic oxygen steel production. Whereas the solubility of some elements from these slags has been well investigated, information about the mineralogy and related leaching, i.e., availability of the environmentally relevant elements chromium (Cr), molybdenum (Mo), and vanadium (V), is still lacking. The aim of this study was to investigate these issues with a modified, four-fraction-based, sequential extraction procedure (F1-F4), combined with X-ray diffraction, of two BOS. Extractants with increasing strength were used (F1 demineralized water, F2 CH 3 COOH + HCl, F3 Na 2 EDTA + NH 2 OH·HCl, and F4 HF + HNO 3 + H 2 O 2 ), and after each fraction, X-ray diffraction was performed. The recovery of Cr was moderate (66.5%) for one BOS, but significantly better (100.2%) for the other one. High recoveries were achieved for the other elements (Mo, 100.8-107.9% and V, 112.6-87.0%), indicating that the sequential extraction procedure was reliable when adapted to BOS. The results showed that Cr and Mo primarily occurred in F4, representing rather immobile elements under natural conditions, which were strongly bound into/onto Fe minerals (srebrodolskite, magnetite, hematite, or wustite). In contrast, V was more mobile with proportional higher findings in F2 and F3, and the X-ray diffraction results reveal that V was not solely bound into Ca minerals (larnite, hatrurite, kirschsteinite, and calcite), but also bound to Fe minerals. The results indicated that the total amount of recovery was a poor indicator of the availability of elements and did not correspond to the leaching of elements from BOS.

Fractionation of trace elements in agricultural soils using ultrasound assisted sequential extraction prior to inductively coupled plasma mass spectrometric determination.

PubMed

Matong, Joseph M; Nyaba, Luthando; Nomngongo, Philiswa N

2016-07-01

The main objectives of this study were to determine the concentration of fourteen trace elements and to investigate their distribution as well as a contamination levels in selected agricultural soils. An ultrasonic assisted sequential extraction procedure derived from three-step BCR method was used for fractionation of trace elements. The total concentration of trace elements in soil samples was obtained by total digestion method in soil samples with aqua regia. The results of the extractable fractions revealed that most of the target trace elements can be transferred to the human being through the food chain, thus leading to serious human health. Enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), risk assessment code (RAC) and individual contamination factors (ICF) were used to assess the environmental impacts of trace metals in soil samples. The EF revealed that Cd was enriched by 3.1-7.2 (except in Soil 1). The Igeo results showed that the soils in the study area was moderately contaminated with Fe, and heavily to extremely polluted with Cd. The soil samples from the unplanted field was found to have highest contamination factor for Cd and lowest for Pb. Soil 3 showed a high risk for Tl and Cd with RAC values of greater than or equal to 50%. In addition, Fe, Ni, Cu, V, As, Mo (except Soil 2), Sb and Pb posed low environmental risk. The modified BCR sequential extraction method provided more information about mobility and environmental implication of studied trace elements in the study area. Copyright © 2016 Elsevier Ltd. All rights reserved.

Risk assessment of trace metals in an extreme environment sediment: shallow, hypersaline, alkaline, and industrial Lake Acıgöl, Denizli, Turkey.

PubMed

Budakoglu, Murat; Karaman, Muhittin; Kumral, Mustafa; Zeytuncu, Bihter; Doner, Zeynep; Yildirim, Demet Kiran; Taşdelen, Suat; Bülbül, Ali; Gumus, Lokman

2018-02-23

The major and trace element component of 48 recent sediment samples in three distinct intervals (0-10, 10-20, and 20-30 cm) from Lake Acıgöl is described to present the current contamination levels and grift structure of detrital and evaporate mineral patterns of these sediments in this extreme saline environment. The spatial and vertical concentrations of major oxides were not uniform in the each subsurface interval. However, similar spatial distribution patterns were observed for some major element couples, due mainly to the detrital and evaporate origin of these elements. A sequential extraction procedure including five distinct steps was also performed to determine the different bonds of trace elements in the < 60-μ particulate size of recent sediments. Eleven trace elements (Ni, Fe, Cd, Pb, Cu, Zn, As, Co, Cr, Al and Mn) in nine surface and subsurface sediment samples were analyzed with chemical partitioning procedures to determine the trace element percentage loads in these different sequential extraction phases. The obtained accuracy values via comparison of the bulk trace metal loads with the total loads of five extraction steps were satisfying for the Ni, Fe, Cd, Zn, and Co. While, bulk analysis results of the Cu, Ni, and V elements have good correlation with total organic matter, organic fraction of sequential extraction characterized by Cu, As, Cd, and Pb. Shallow Lake Acıgöl sediment is characteristic with two different redox layer a) oxic upper level sediments, where trace metals are mobilized, b) reduced subsurface level, where the trace metals are precipitated.

Geochemical and multi-isotopic (87Sr/86Sr, 143Nd/144Nd, 238U/235U) perspectives of sediment sources, depositional conditions, and diagenesis of the Marcellus Shale, Appalachian Basin, USA

NASA Astrophysics Data System (ADS)

Phan, Thai T.; Gardiner, James B.; Capo, Rosemary C.; Stewart, Brian W.

2018-02-01

We investigate sediment sources, depositional conditions and diagenetic processes affecting the Middle Devonian Marcellus Shale in the Appalachian Basin, eastern USA, a major target of natural gas exploration. Multiple proxies, including trace metal contents, rare earth elements (REE), the Sm-Nd and Rb-Sr isotope systems, and U isotopes were applied to whole rock digestions and sequentially extracted fractions of the Marcellus shale and adjacent units from two locations in the Appalachian Basin. The narrow range of εNd values (from -7.8 to -6.4 at 390 Ma) is consistent with derivation of the clastic sedimentary component of the Marcellus Shale from a well-mixed source of fluvial and eolian material of the Grenville orogenic belt, and indicate minimal post-depositional alteration of the Sm-Nd system. While silicate minerals host >80% of the REE in the shale, data from sequentially extracted fractions reflect post-depositional modifications at the mineralogical scale, which is not observed in whole rock REE patterns. Limestone units thought to have formed under open ocean (oxic) conditions have δ238U values and REE patterns consistent with modern seawater. The δ238U values in whole rock shale and authigenic phases are greater than those of modern seawater and the upper crust. The δ238U values of reduced phases (the oxidizable fraction consisting of organics and sulfide minerals) are ∼0.6‰ greater than that of modern seawater. Bulk shale and carbonate cement extracted from the shale have similar δ238U values, and are greater than δ238U values of adjacent limestone units. We suggest these trends are due to the accumulation of chemically and, more likely, biologically reduced U from anoxic to euxinic bottom water as well as the influence of diagenetic reactions between pore fluids and surrounding sediment and organic matter during diagenesis and catagenesis.

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

Favorito, Jessica E.; Luxton, Todd P.; Eick, Matthew J.

Selenium is a trace element found in western US soils, where ingestion of Se-accumulating plants has resulted in livestock fatalities. Therefore, a reliable understanding of Se speciation and bioavailability is critical for effective mitigation. Sequential extraction procedures (SEP) are often employed to examine Se phases and speciation in contaminated soils but may be limited by experimental conditions. We examined the validity of a SEP using X-ray absorption spectroscopy (XAS) for both whole and a sequence of extracted soils. The sequence included removal of soluble, PO4-extractable, carbonate, amorphous Fe-oxide, crystalline Fe-oxide, organic, and residual Se forms. For whole soils, XANES analysesmore » indicated Se(0) and Se(-II) predominated, with lower amounts of Se(IV) present, related to carbonates and Fe-oxides. Oxidized Se species were more elevated and residual/elemental Se was lower than previous SEP results from ICP-AES suggested. For soils from the SEP sequence, XANES results indicated only partial recovery of carbonate, Fe-oxide and organic Se. This suggests Se was incompletely removed during designated extractions, possibly due to lack of mineral solubilization or reagent specificity. Selenium fractions associated with Fe-oxides were reduced in amount or removed after using hydroxylamine HCl for most soils examined. XANES results indicate partial dissolution of solid-phases may occur during extraction processes. This study demonstrates why precautions should be taken to improve the validity of SEPs. Mineralogical and chemical characterizations should be completed prior to SEP implementation to identify extractable phases or mineral components that may influence extraction effectiveness. Sequential extraction procedures can be appropriately tailored for reliable quantification of speciation in contaminated soils.« less

Mining local climate data to assess spatiotemporal dengue fever epidemic patterns in French Guiana.

PubMed

Flamand, Claude; Fabregue, Mickael; Bringay, Sandra; Ardillon, Vanessa; Quénel, Philippe; Desenclos, Jean-Claude; Teisseire, Maguelonne

2014-10-01

To identify local meteorological drivers of dengue fever in French Guiana, we applied an original data mining method to the available epidemiological and climatic data. Through this work, we also assessed the contribution of the data mining method to the understanding of factors associated with the dissemination of infectious diseases and their spatiotemporal spread. We applied contextual sequential pattern extraction techniques to epidemiological and meteorological data to identify the most significant climatic factors for dengue fever, and we investigated the relevance of the extracted patterns for the early warning of dengue outbreaks in French Guiana. The maximum temperature, minimum relative humidity, global brilliance, and cumulative rainfall were identified as determinants of dengue outbreaks, and the precise intervals of their values and variations were quantified according to the epidemiologic context. The strongest significant correlations were observed between dengue incidence and meteorological drivers after a 4-6-week lag. We demonstrated the use of contextual sequential patterns to better understand the determinants of the spatiotemporal spread of dengue fever in French Guiana. Future work should integrate additional variables and explore the notion of neighborhood for extracting sequential patterns. Dengue fever remains a major public health issue in French Guiana. The development of new methods to identify such specific characteristics becomes crucial in order to better understand and control spatiotemporal transmission. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Determination of the Pb, Cr, and Cd distribution patterns with various chlorine additives in the bottom ashes of a low-temperature two-stage fluidized bed incinerator by chemical sequential extraction.

PubMed

Peng, Tzu-Huan; Lin, Chiou-Liang; Wey, Ming-Yen

2015-09-15

A novel low-temperature two-stage fluidized bed (LTTSFB) incinerator has been successfully developed to control heavy-metal emissions during municipal solid waste (MSW) treatment. However, the characteristics of the residual metal patterns during this process are still unclear. The aim of this study was to investigate the metal patterns in the different partitions of the LTTSFB bottom ash by chemical sequential extraction. Artificial waste was used to simulate the MSW. Different parameters including the first-stage temperature, chloride additives, and operating gas velocity were also considered. Results indicated that during the low-temperature treatment process, a high metal mobility phase exists in the first-stage sand bed. The main patterns of Cd, Pb, and Cr observed were the water-soluble, exchangeable, and residual forms, respectively. With the different Cl additives, the results showed that polyvinyl chloride addition increased metal mobility in the LTTSFB bottom ash, while, sodium chloride addition may have reduced metal mobility due to the formation of eutectic material. The second-stage sand bed was found to have a lower risk of metal leaching. The results also suggested that, the residual ashes produced by the LTTSFB system must be taken into consideration given their high metal mobility. Copyright © 2015 Elsevier B.V. All rights reserved.

Spatial and Temporal Variability in Sediment P Distribution and Speciation in Coastal Louisiana

NASA Astrophysics Data System (ADS)

Bowes, K.; White, J. R.; Maiti, K.

2017-12-01

Excess loading of phosphorus (P) and nitrogen (N) into aquatic systems leads to degradation of water quality and diminished important ecosystem services. In the Northern Gulf of Mexico (NGOM), excess P and N loading has led to a seasonally present hypoxic area with less than 2 mg/L O2 in bottom waters, approximating 26,000 km2 in 2017. A sequential extraction (SEDEX) method was performed on surficial sediments from five different coastal and shelf sites as a function of distance from the Mississippi River mouth in the NGOM. To better quantify temporal variability in P distribution and speciation, samples were collected during both low (August) and high (May) river flow regimes. Sequential extraction techniques have been successful in separating pools of P into exchangeable or loosely sorbed P, Fe-P, Authigenic-P, Detrital-P, and Organic-P. Preliminary results suggest Authigenic-P is approximately 3-6 times more concentrated in NGOM sediments than all other P pools. Fractionation results did not show a consistent trend with sediment depth. Sediment samples had an average moisture content of 58.72% ± 12.06% and an average bulk density of 0.582 ± 0.275 g/cm3. Continued analysis of P speciation and cycling in NGOM sediments is critical in understanding the driving force behind coastal eutrophication and informing effective nutrient management strategies.

Single shot laser speckle based 3D acquisition system for medical applications

NASA Astrophysics Data System (ADS)

Khan, Danish; Shirazi, Muhammad Ayaz; Kim, Min Young

2018-06-01

The state of the art techniques used by medical practitioners to extract the three-dimensional (3D) geometry of different body parts requires a series of images/frames such as laser line profiling or structured light scanning. Movement of the patients during scanning process often leads to inaccurate measurements due to sequential image acquisition. Single shot structured techniques are robust to motion but the prevalent challenges in single shot structured light methods are the low density and algorithm complexity. In this research, a single shot 3D measurement system is presented that extracts the 3D point cloud of human skin by projecting a laser speckle pattern using a single pair of images captured by two synchronized cameras. In contrast to conventional laser speckle 3D measurement systems that realize stereo correspondence by digital correlation of projected speckle patterns, the proposed system employs KLT tracking method to locate the corresponding points. The 3D point cloud contains no outliers and sufficient quality of 3D reconstruction is achieved. The 3D shape acquisition of human body parts validates the potential application of the proposed system in the medical industry.

Neuromuscular disease classification system

NASA Astrophysics Data System (ADS)

Sáez, Aurora; Acha, Begoña; Montero-Sánchez, Adoración; Rivas, Eloy; Escudero, Luis M.; Serrano, Carmen

2013-06-01

Diagnosis of neuromuscular diseases is based on subjective visual assessment of biopsies from patients by the pathologist specialist. A system for objective analysis and classification of muscular dystrophies and neurogenic atrophies through muscle biopsy images of fluorescence microscopy is presented. The procedure starts with an accurate segmentation of the muscle fibers using mathematical morphology and a watershed transform. A feature extraction step is carried out in two parts: 24 features that pathologists take into account to diagnose the diseases and 58 structural features that the human eye cannot see, based on the assumption that the biopsy is considered as a graph, where the nodes are represented by each fiber, and two nodes are connected if two fibers are adjacent. A feature selection using sequential forward selection and sequential backward selection methods, a classification using a Fuzzy ARTMAP neural network, and a study of grading the severity are performed on these two sets of features. A database consisting of 91 images was used: 71 images for the training step and 20 as the test. A classification error of 0% was obtained. It is concluded that the addition of features undetectable by the human visual inspection improves the categorization of atrophic patterns.

CFD simulation of hemodynamics in sequential and individual coronary bypass grafts based on multislice CT scan datasets.

PubMed

Hajati, Omid; Zarrabi, Khalil; Karimi, Reza; Hajati, Azadeh

2012-01-01

There is still controversy over the differences in the patency rates of the sequential and individual coronary artery bypass grafting (CABG) techniques. The purpose of this paper was to non-invasively evaluate hemodynamic parameters using complete 3D computational fluid dynamics (CFD) simulations of the sequential and the individual methods based on the patient-specific data extracted from computed tomography (CT) angiography. For CFD analysis, the geometric model of coronary arteries was reconstructed using an ECG-gated 64-detector row CT. Modeling the sequential and individual bypass grafting, this study simulates the flow from the aorta to the occluded posterior descending artery (PDA) and the posterior left ventricle (PLV) vessel with six coronary branches based on the physiologically measured inlet flow as the boundary condition. The maximum calculated wall shear stress (WSS) in the sequential and the individual models were estimated to be 35.1 N/m(2) and 36.5 N/m(2), respectively. Compared to the individual bypass method, the sequential graft has shown a higher velocity at the proximal segment and lower spatial wall shear stress gradient (SWSSG) due to the flow splitting caused by the side-to-side anastomosis. Simulated results combined with its surgical benefits including the requirement of shorter vein length and fewer anastomoses advocate the sequential method as a more favorable CABG method.

Chemically differentiating ascorbate-mediated dissolution of quantum dots in cell culture media

NASA Astrophysics Data System (ADS)

Su, Cheng-Kuan; Sun, Yuh-Chang

2013-02-01

To investigate the dynamic dissolution of quantum dots (QDs) in cell culture media, in this study we constructed an online automatic analytical system comprising a sequential in-tube solid phase extraction (SPE) device and an inductively coupled plasma (ICP) mass spectrometer. By means of selectively extracting QDs and cadmium ions (Cd2+) onto the interior surface of the polytetrafluoroethylene (PTFE) tube, this novel SPE device could be used to determine the degree of QD dissolution through a simple adjustment of sample acidity. To the best of our knowledge, this study is the first to exploit PTFE tubing as a selective SPE adsorbent for the online chemical differentiation of QDs and Cd2+ ions with the goal of monitoring the phenomenon of QD dissolution in complicated biological matrices. We confirmed the analytical reliability of this system through comparison of the measured Cd-to-QD ratios to the expected values. When analyzing QDs and Cd2+ ions at picomolar levels, a temporal resolution of 8 min was required to load sufficient amounts of the analytes to meet the sensitivity requirements of the ICP mass spectrometer. To demonstrate the practicability of this developed method, we measured the dynamic variations in the Cd-to-QD705 ratio in the presence of ascorbate as a physiological stimulant to generate reactive oxygen species in cell culture media and trigger the dissolution of QDs; our results suggest that the ascorbate-induced QD dissolution was dependent on the time, treatment concentration, and nature of the biomolecule.To investigate the dynamic dissolution of quantum dots (QDs) in cell culture media, in this study we constructed an online automatic analytical system comprising a sequential in-tube solid phase extraction (SPE) device and an inductively coupled plasma (ICP) mass spectrometer. By means of selectively extracting QDs and cadmium ions (Cd2+) onto the interior surface of the polytetrafluoroethylene (PTFE) tube, this novel SPE device could be used to determine the degree of QD dissolution through a simple adjustment of sample acidity. To the best of our knowledge, this study is the first to exploit PTFE tubing as a selective SPE adsorbent for the online chemical differentiation of QDs and Cd2+ ions with the goal of monitoring the phenomenon of QD dissolution in complicated biological matrices. We confirmed the analytical reliability of this system through comparison of the measured Cd-to-QD ratios to the expected values. When analyzing QDs and Cd2+ ions at picomolar levels, a temporal resolution of 8 min was required to load sufficient amounts of the analytes to meet the sensitivity requirements of the ICP mass spectrometer. To demonstrate the practicability of this developed method, we measured the dynamic variations in the Cd-to-QD705 ratio in the presence of ascorbate as a physiological stimulant to generate reactive oxygen species in cell culture media and trigger the dissolution of QDs; our results suggest that the ascorbate-induced QD dissolution was dependent on the time, treatment concentration, and nature of the biomolecule. Electronic supplementary information (ESI) available: The operation sequence, optimized parameters, instrumental operation conditions, and schematic representations for the proposed sequential in-tube PTFE SPE-ICP-MS hyphenated system are provided. See DOI: 10.1039/c2nr33365a

Monitoring of electrokinetic removal of heavy metals in tailing-soils using sequential extraction analysis.

PubMed

Kim, S O; Kim, K W

2001-08-17

This research focused on the monitoring of the electrokinetic removal of heavy metals from tailing-soils, and emphasizes the dependency of removal efficiencies upon their physico-chemical states, as demonstrated by the different extraction methods adopted, which included aqua regia and sequential extraction. The tailing-soils examined contained high concentrations of target metal contaminants (Cd=179mgkg(-1), Cu=207mgkg(-1), Pb=5175mgkg(-1), and Zn=7600mgkg(-1)). The removal efficiencies of the different metals were significantly influenced by their speciations, mobilities and affinities (adsorption capacities) in the soil matrix. The removal efficiencies of mobile and weakly bound fractions, such as the exchangeable fraction were more than 90% by electrokinetic treatment, but strongly bound fractions, such as the organically bound species and residual fraction were not significantly removed (less than 30% removal efficiencies). In accordance with the general sequence of mobilities of heavy metals in soils, the removal efficiencies of more mobile heavy metals (Cd, Cu, and Zn) were higher than that of less mobile heavy metal (Pb).

Sequential co-production of biodiesel and bioethanol with spent coffee grounds.

PubMed

Kwon, Eilhann E; Yi, Haakrho; Jeon, Young Jae

2013-05-01

The sequential co-production of bioethanol and biodiesel from spent coffee grounds was investigated. The direct conversion of bioethanol from spent coffee grounds was not found to be a desirable option because of the relatively slow enzymatic saccharification behavior in the presence of triglycerides and the free fatty acids (FFAs) found to exist in the raw materials. Similarly, the direct transformation of the spent coffee grounds into ethanol without first extracting lipids was not found to be a feasible alternative. However, the crude lipids extracted from the spent coffee grounds were themselves converted into fatty acid methyl ester (FAME) and fatty acid ethyl ester (FAEE) via the non-catalytic biodiesel transesterification reaction. The yields of bioethanol and biodiesel were 0.46 g g(-1) and 97.5±0.5%, which were calculated based on consumed sugar and lipids extracted from spent coffee grounds respectively. Thus, this study clearly validated our theory that spent coffee grounds could be a strong candidate for the production of bioethanol and biodiesel. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fractionation study in bioleached metallurgy wastes using six-step sequential extraction.

PubMed

Krasnodebska-Ostrega, Beata; Pałdyna, Joanna; Kowalska, Joanna; Jedynak, Łukasz; Golimowski, Jerzy

2009-08-15

The stored metallurgy wastes contain residues from ore processing operations that are characterized by relatively high concentrations of heavy metals. The bioleaching process makes use of bacteria to recover elements from industrial wastes and to decrease potential risk of environmental contamination. Wastes were treated by solutions containing bacteria. In this work, the optimized six-stage sequential extraction procedure was applied for the fractionation of Ni, Cr, Fe, Mn, Cu and Zn in iron-nickel metallurgy wastes deposited in Southern Poland (Szklary). Fractionation and total concentrations of elements in wastes before and after various bioleaching treatments were studied. Analyses of the extracts were performed by ICP-MS and FAAS. To achieve the most effective bioleaching of Zn, Cr, Ni, Cu, Mn, Fe the usage of both autotrophic and heterotrophic bacteria in sequence, combined with flushing of the residue after bioleaching is required. 80-100% of total metal concentrations were mobilized after the proposed treatment. Wastes treated according to this procedure could be deposited without any risk of environmental contamination and additionally the metals could be recovered for industrial purposes.

Attention-Based Recurrent Temporal Restricted Boltzmann Machine for Radar High Resolution Range Profile Sequence Recognition.

PubMed

Zhang, Yifan; Gao, Xunzhang; Peng, Xuan; Ye, Jiaqi; Li, Xiang

2018-05-16

The High Resolution Range Profile (HRRP) recognition has attracted great concern in the field of Radar Automatic Target Recognition (RATR). However, traditional HRRP recognition methods failed to model high dimensional sequential data efficiently and have a poor anti-noise ability. To deal with these problems, a novel stochastic neural network model named Attention-based Recurrent Temporal Restricted Boltzmann Machine (ARTRBM) is proposed in this paper. RTRBM is utilized to extract discriminative features and the attention mechanism is adopted to select major features. RTRBM is efficient to model high dimensional HRRP sequences because it can extract the information of temporal and spatial correlation between adjacent HRRPs. The attention mechanism is used in sequential data recognition tasks including machine translation and relation classification, which makes the model pay more attention to the major features of recognition. Therefore, the combination of RTRBM and the attention mechanism makes our model effective for extracting more internal related features and choose the important parts of the extracted features. Additionally, the model performs well with the noise corrupted HRRP data. Experimental results on the Moving and Stationary Target Acquisition and Recognition (MSTAR) dataset show that our proposed model outperforms other traditional methods, which indicates that ARTRBM extracts, selects, and utilizes the correlation information between adjacent HRRPs effectively and is suitable for high dimensional data or noise corrupted data.

Effect of mechanical ventilation on systemic oxygen extraction and lactic acidosis during early septic shock in rats.

PubMed

Griffel, M I; Astiz, M E; Rackow, E C; Weil, M H

1990-01-01

We studied the effect of mechanical ventilation on systemic oxygen extraction and lactic acidosis in peritonitis and shock in rats. Sepsis was induced by cecal ligation and perforation. After tracheostomy, rats were randomized to spontaneous breathing (S) or mechanical ventilation with paralysis (V). Five animals were studied in each group. The V animals were paralyzed with pancuronium bromide to eliminate respiratory effort. Mechanical ventilation consisted of controlled ventilation using a rodent respirator with periodic adjustment of minute ventilation to maintain PaCO2 and pH within normal range. Arterial and central venous blood gases and thermodilution cardiac output were measured at baseline before abdominal surgery, and sequentially at 0.5, 3.5, and 6 h after surgery. At 6 h, cardiac output was 193 +/- 30 ml/kg.min in S animals and 199 +/- 32 ml/kg.min in V animals (NS). The central venous oxygen saturation was 27.4 +/- 4.7% in S animals and 30.0 +/- 6.4% in V animals (NS). Systemic oxygen extraction was 70 +/- 5% in S animals and 67 +/- 6% in V animals (NS). Arterial lactate was 2.4 +/- 0.4 mmol/L in S animals and 2.2 +/- 0.5 mmol/L in V animals (NS). The S animals developed lethal hypotension at 6.6 +/- 0.4 h compared to 6.8 +/- 0.4 h in V animals (NS). These data suggest that mechanical ventilation does not decrease systemic oxygen extraction or ameliorate the development of lactic acidosis during septic shock.

Speciation and transformation of heavy metals during vermicomposting of animal manure.

PubMed

Lv, Baoyi; Xing, Meiyan; Yang, Jian

2016-06-01

This work was conducted to evaluate the effects of vermicomposting on the speciation and mobility of heavy metals (Zn, Pb, Cr, and Cu) in cattle dung (CD) and pig manure (PM) using tessier sequential extraction method. Results showed that the pH, total organic carbon and C/N ratio were reduced, while the electric conductivity and humic acid increased after 90days vermicomposting. Moreover, the addition of earthworm could accelerate organic stabilization in vermicomposting. The total heavy metals in final vermicompost from CD and PM were higher than the initial values and the control without worms. Sequential extraction indicated that vermicomposting decreased the migration and availability of heavy metals, and the earthworm could reduce the mobile fraction, while increase the stable fraction of heavy metals. Furthermore, these results indicated that vermicomposting played a positive role in stabilizing heavy metals in the treatment of animal manure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Uranium decay daughters from isolated mines: Accumulation and sources.

PubMed

Cuvier, A; Panza, F; Pourcelot, L; Foissard, B; Cagnat, X; Prunier, J; van Beek, P; Souhaut, M; Le Roux, G

2015-11-01

This study combines in situ gamma spectrometry performed at different scales, in order to accurately locate the contamination pools, to identify the concerned radionuclides and to determine the distribution of the contaminants from soil to bearing phase scale. The potential mobility of several radionuclides is also evaluated using sequential extraction. Using this procedure, an accumulation area located downstream of a former French uranium mine and concentrating a significant fraction of radioactivity is highlighted. We report disequilibria in the U-decay chains, which are likely related to the processes implemented on the mining area. Coupling of mineralogical analyzes with sequential extraction allow us to highlight the presence of barium sulfate, which may be the carrier of the Ra-226 activities found in the residual phase (Ba(Ra)SO4). In contrast, uranium is essentially in the reducible fraction and potentially trapped in clay-iron coatings located on the surface of minerals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cadmium partition in river sediments from an area affected by mining activities.

PubMed

Vasile, Georgiana D; Vlădescu, Luminiţa

2010-08-01

In this paper, the cadmium distribution in Certej River sediments in an area seriously affected by intense mining activities has been studied. The main objective of this study was the evaluation of partition of this metal into different operational defined fractions by sequential extractions. Community Bureau of Reference (BCR) sequential extraction was used to isolate different fractions. The sediment quality was assessed both upstream and downstream the pollution input points, along the Certej River, in order to reveal a possible accumulation of cadmium in sediments and the seasonal changes in cadmium concentrations in BCR sediment phases. Our results reveal that most of the cadmium content is divided between both the soluble and iron and manganese hydrated oxide fractions. Based on total cadmium concentrations in sediments, the enrichment factors were estimated using aluminum as normalizing element and the regression curve Cd/Al corresponding to the geochemical background of the studied area.

Investigations of Cu, Pb and Zn partitioning by sequential extraction in harbour sediments after electrodialytic remediation.

PubMed

Kirkelund, Gunvor M; Ottosen, Lisbeth M; Villumsen, Arne

2010-05-01

Electrodialytic remediation was used to remove Cu, Zn and Pb from three different contaminated harbour sediments. Electrodialytic experiments lasting 2 and 4 weeks were performed and 48-86% Cu, 74-90% Zn and 62-88% Pb were removed from the different sediments and the removal increased with longer remediation time. A three step sequential extraction scheme (BCR), with an extra residual step, was used to evaluate the heavy metal distribution in the sediments before and after electrodialytic remediation. Cu was mainly associated with the oxidisable phase of the sediment, both before and after remediation. Zn and Pb were found in the exchangeable and reducible phases before remediation. Zn was still found in the exchangeable and reducible phases after remediation, whereas most Pb was removed from these phases during electrodialytic remediation. Copyright 2010 Elsevier Ltd. All rights reserved.

Determination of element affinities by density fractionation of bulk coal samples

USGS Publications Warehouse

Querol, X.; Klika, Z.; Weiss, Z.; Finkelman, R.B.; Alastuey, A.; Juan, R.; Lopez-Soler, A.; Plana, F.; Kolker, A.; Chenery, S.R.N.

2001-01-01

A review has been made of the various methods of determining major and trace element affinities for different phases, both mineral and organic in coals, citing their various strengths and weaknesses. These include mathematical deconvolution of chemical analyses, direct microanalysis, sequential extraction procedures and density fractionation. A new methodology combining density fractionation with mathematical deconvolution of chemical analyses of whole coals and their density fractions has been evaluated. These coals formed part of the IEA-Coal Research project on the Modes of Occurrence of Trace Elements in Coal. Results were compared to a previously reported sequential extraction methodology and showed good agreement for most elements. For particular elements (Be, Mo, Cu, Se and REEs) in specific coals where disagreement was found, it was concluded that the occurrence of rare trace element bearing phases may account for the discrepancy, and modifications to the general procedure must be made to account for these.

New data on the mobility of Pt emitted from catalytic converters.

PubMed

Fliegel, Daniel; Berner, Zsolt; Eckhardt, Detlef; Stüben, Doris

2004-05-01

The mobility and speciation of Pt was investigated in dust deposited in highway tunnels and in gully sediments. For this, a sequential extraction technique was used in combination with a microwave digestion procedure, followed by detection of Pt with high resolution ICP-MS. A digestion procedure using HNO(3)/HCl/H(2)O(2) was developed and its efficiency tested for environmental materials. Total Pt contents ranged from approximately 100 to 300 microg/kg. The high share of chemically mobile Pt in the tunnel dust (up to about 40%) indicates that Pt is predominantly emitted in a mobile form from the converter. The absence of a mobile fraction in the gully sediment is explained by the elution of Pt by run-off. Except for the mobile and easily mobilised fractions none of the other fractions of the sequential extraction contains Pt, neither in the dust samples nor in the gully sediment.

Structural characterization of polysaccharides from bamboo

NASA Astrophysics Data System (ADS)

Kamil, Ruzaimah Nik Mohamad; Yusuf, Nur'aini Raman; Yunus, Normawati M.; Yusup, Suzana

2014-10-01

The alkaline and water soluble polysaccharides were isolate by sequential extractions with distilled water, 60% ethanol containing 1%, 5% and 8% NaOH. The samples were prepared at 60 °C for 3 h from local bamboo. The functional group of the sample were examined using FTIR analysis. The most precipitate obtained is from using 60% ethanol containing 8% NaOH with yield of 2.6%. The former 3 residues isolated by sequential extractions with distilled water, 60% ethanol containing 1% and 5% NaOH are barely visible after filtering with cellulose filter paper. The FTIR result showed that the water-soluble polysaccharides consisted mainly of OH group, CH group, CO indicates the carbohydrate and sugar chain. The sample weight loss was slightly decreased with increasing of temperature.

Formation of iron nanoparticles and increase in iron reactivity in mineral dust during simulated cloud processing.

PubMed

Shi, Zongbo; Krom, Michael D; Bonneville, Steeve; Baker, Alex R; Jickells, Timothy D; Benning, Liane G

2009-09-01

The formation of iron (Fe) nanoperticles and increase in Fe reactivity in mineral dust during simulated cloud processing was investigated using high-resolution microscopy and chemical extraction methods. Cloud processing of dust was experimentally simulated via an alternation of acidic (pH 2) and circumneutral conditions (pH 5-6) over periods of 24 h each on presieved (<20 microm) Saharan soil and goethite suspensions. Microscopic analyses of the processed soil and goethite samples reveal the neo-formation of Fe-rich nanoparticle aggregates, which were not found initially. Similar Fe-rich nanoparticles were also observed in wet-deposited Saharen dusts from the western Mediterranean but not in dry-deposited dust from the eastern Mediterranean. Sequential Fe extraction of the soil samples indicated an increase in the proportion of chemically reactive Fe extractable by an ascorbate solution after simulated cloud processing. In addition, the sequential extractions on the Mediterranean dust samples revealed a higher content of reactive Fe in the wet-deposited dust compared to that of the dry-deposited dust These results suggestthat large variations of pH commonly reported in aerosol and cloud waters can trigger neo-formation of nanosize Fe particles and an increase in Fe reactivity in the dust

Applications of derivatization reactions to trace organic compounds during sample preparation based on pressurized liquid extraction.

PubMed

Carro, Antonia M; González, Paula; Lorenzo, Rosa A

2013-06-28

Pressurized liquid extraction (PLE) is an exhaustive technique used for the extraction of analytes from solid samples. Temperature, pressure, solvent type and volume, and the addition of other reagents notably influence the efficiency of the extraction. The analytical applications of this technique can be improved by coupling with appropriate derivatization reactions. The aim of this review is to discuss the recent applications of the sequential combination of PLE with derivatization and the approaches that involve simultaneous extraction and in situ derivatization. The potential of the latest developments to the trace analysis of environmental, food and biological samples is also analyzed. Copyright © 2013 Elsevier B.V. All rights reserved.

Sequential photocatalyst-assisted digestion and vapor generation device coupled with anion exchange chromatography and inductively coupled plasma mass spectrometry for speciation analysis of selenium species in biological samples.

PubMed

Tsai, Yun-ni; Lin, Cheng-hsing; Hsu, I-hsiang; Sun, Yuh-chang

2014-01-02

We have developed an on-line sequential photocatalyst-assisted digestion and vaporization device (SPADVD), which operates through the nano-TiO2-catalyzed photo-oxidation and reduction of selenium (Se) species, for coupling between anion exchange chromatography (LC) and inductively coupled plasma mass spectrometry (ICP-MS) systems to provide a simple and sensitive hyphenated method for the speciation analysis of Se species without the need for conventional chemical digestion and vaporization techniques. Because our proposed on-line SPADVD allows both organic and inorganic Se species in the column effluent to be converted on-line into volatile Se products, which are then measured directly through ICP-MS, the complexity of the procedure and the probability of contamination arising from the use of additional chemicals are both low. Under the optimized conditions for SPADVD - using 1g of nano-TiO2 per liter, at pH 3, and illuminating for 80 s - we found that Se(IV), Se(VI), and selenomethionine (SeMet) were all converted quantitatively into volatile Se products. In addition, because the digestion and vaporization efficiencies of all the tested selenicals were improved when using our proposed on-line LC/SPADVD/ICP-MS system, the detection limits for Se(IV), Se(VI), and SeMet were all in the nanogram-per-liter range (based on 3σ). A series of validation experiments - analysis of neat and spiked extracted samples - indicated that our proposed methods could be applied satisfactorily to the speciation analysis of organic and inorganic Se species in the extracts of Se-enriched supplements. Copyright © 2013. Published by Elsevier B.V.

Proteolytic events in the post-translational processing of somatostatin precursors from rat brain cortex and anglerfish pancreatic islets.

PubMed

Cohen, P; Morel, A; Gluschankof, P; Gomez, S; Nicolas, P

1985-01-01

An Arg-Lys esteropeptidase which converts somatostatin-28 (S-28) into somatostatin-14 (S-14) was detected in rat brain cortical extracts using a synthetic undecapeptide substrate mimicking the octacosapeptide sequence at the restriction site. This enzyme system was unable to release either the octacosapeptide or S-14 from the 15,000 mol wt (15K) rat hypothalamic precursor. This argues in favor of sequential degradation of the precursor into S-14 via S-28 as an obligatory intermediate. Another in vivo processing system was analyzed in the anglerfish pancreatic Brockmann organs. Here, cloning of two cDNA corresponding to two mRNA species predicts two distinct somatostatins precursors, called prosomatostatins I and II (Hobart et al., Nature 288:137, 1980). While a single S-14 can be detected in extracts made from this pancreatic tissue, indistinguishable from the mammalian species, two S-28 species could be separated by HPLC. Immunochemical and biochemical evidence indicates that the second species should correspond to anglerfish S-28 (AF S-28), the product of prosomatostatin-II processing in vivo. Amino acid analysis, together with the determined complete amino acid sequence of this peptide, demonstrates that this is indeed the case and that AF S-28 contains in its C-terminal half the [Tyr7, Gly10] derivative of S-14. These observations give an example of a AF S-28 being a terminal active product of prosomatostatin processing. They suggest that this octacosapeptide, which is potent on the inhibition of growth hormone release by anterior pituitary cells, may play such a role in the gastrointestinal tract of the anglerfish. These results, while not excluding alternative routes, give support to a sequential processing of the 15 K precursor----S-28----S-14.

CONTINUOUS DISSOLVER EXTRACTOR FOR PROCESSING METAL

DOEpatents

Lemon, R.B.; Buckham, J.A.

1959-02-01

An apparatus is presented for the continuous dissolution of metal slugs in an aqueous acid and sequential continuous extraction of selected metal values from the acid solution by counter-current contact with an organic solvent. The apparatus comprises a cylindrical tank divided into upper and lower sections. Dissolution of the metal slug takes place in the lower section and the solution so produced is continuously fed to the topmost plate of the upper extraction section. An immiscible organic extractant is continuously passed by a pulsing pump into the lowermost unit of the extraction section. Suitable piping and valving permits of removing the aqueous raffinate solution from the lowermost portion of the extraction section, and simultaneous removal of organic solvent extractant containing the desired product from the uppermost portion of the extraction section.

The added value of mifepristone to non-surgical treatment regimens for uterine evacuation in case of early pregnancy failure: a systematic review of the literature.

PubMed

van den Berg, Joyce; Gordon, Bernardus B M; Snijders, Marcus P M L; Vandenbussche, Frank P H A; Coppus, Sjors F P J

2015-12-01

Early pregnancy failure (EPF) is a common complication of pregnancy. Surgical intervention carries a risk of complications and, therefore, medical treatment appears to be a safe alternative. Unfortunately, the current medical treatment with misoprostol alone has complete evacuation rates between 53% and 87%. Some reports suggest that sequential treatment with mifepristone and misoprostol leads to higher success rates than misoprostol alone. To evaluate the added value of mifepristone to current non-surgical treatment regimens in women with EPF we performed a systematic literature search. Electronic databases were searched: PubMed, Cochrane Library, Current Controlled Trials, and ClinicalTrials.gov. Clinical studies, both randomised and non-randomised trials, reporting on the added value of mifepristone to current non-surgical treatment regimens in women with EPF were included. Data of sixteen studies were extracted using a data extraction sheet (based on the Cochrane Consumers and Communication Review Group's data extraction template). The methodological quality was assessed using the Cochrane Collaboration Risk of Bias tool. In five randomised and eleven non-randomised trials, success rates of sequential treatment with mifepristone and misoprostol in case of EPF varied between 52% and 95%. Large heterogeneity existed in treatment regimens and comparators between studies. The existing evidence is insufficient to draw firm conclusions about the added value of mifepristone to misoprostol alone. A sufficiently powered randomised, double blinded placebo-controlled trial is urgently required to test whether, in EPF, the sequential combination of mifepristone with misoprostol is superior to misoprostol only. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A GPU-based large-scale Monte Carlo simulation method for systems with long-range interactions

NASA Astrophysics Data System (ADS)

Liang, Yihao; Xing, Xiangjun; Li, Yaohang

2017-06-01

In this work we present an efficient implementation of Canonical Monte Carlo simulation for Coulomb many body systems on graphics processing units (GPU). Our method takes advantage of the GPU Single Instruction, Multiple Data (SIMD) architectures, and adopts the sequential updating scheme of Metropolis algorithm. It makes no approximation in the computation of energy, and reaches a remarkable 440-fold speedup, compared with the serial implementation on CPU. We further use this method to simulate primitive model electrolytes, and measure very precisely all ion-ion pair correlation functions at high concentrations. From these data, we extract the renormalized Debye length, renormalized valences of constituent ions, and renormalized dielectric constants. These results demonstrate unequivocally physics beyond the classical Poisson-Boltzmann theory.

Better together: reduced compliance after sequential versus simultaneous bilateral hearing aids fitting.

PubMed

Lavie, Limor; Banai, Karen; Attias, Joseph; Karni, Avi

2014-03-01

The purpose of this study was to determine the effects of sequential versus simultaneous bilateral hearing aids fitting on patient compliance. Thirty-six older adults with hearing impairment participated in this study. Twelve were fitted with bilateral hearing aids simultaneously. The remaining participants were fitted sequentially: One hearing aid (to the left or to the right ear) was used initially; 1 month later, the other ear was also fitted with a hearing aid for bilateral use. Self-reports on usefulness and compliance were elicited after the first and second months of hearing aid use. In addition, the number of hours the hearing aids were used was extracted from the data loggings of each device. Simultaneous fitting resulted in high levels of compliance and consistent usage throughout the study period. Sequential fitting resulted in abrupt reduction in compliance and hours of use once the second hearing aid was added, both in the clinical scoring and in the data loggings. Simultaneous fitting of bilateral hearing aids results in better compliance compared with sequential fitting. The addition of a second hearing aid after a relatively short period of monaural use may lead to inconsistent use of both hearing aids.

Digital coding of Shuttle TV

NASA Technical Reports Server (NTRS)

Habibi, A.; Batson, B.

1976-01-01

Space Shuttle will be using a field-sequential color television system for the first few missions, but the present plans are to switch to a NTSC color TV system for future missions. The field-sequential color TV system uses a modified black and white camera, producing a TV signal with a digital bandwidth of about 60 Mbps. This article discusses the characteristics of the Shuttle TV systems and proposes a bandwidth-compression technique for the field-sequential color TV system that could operate at 13 Mbps to produce a high-fidelity signal. The proposed bandwidth-compression technique is based on a two-dimensional DPCM system that utilizes temporal, spectral, and spatial correlation inherent in the field-sequential color TV imagery. The proposed system requires about 60 watts and less than 200 integrated circuits.

A recyclable ionic liquid-oxomolybdenum(vi) catalytic system for the oxidative desulfurization of model and real diesel fuel.

PubMed

Julião, Diana; Gomes, Ana C; Pillinger, Martyn; Valença, Rita; Ribeiro, Jorge C; Gonçalves, Isabel S; Balula, Salete S

2016-10-14

The oxidative desulfurization of model and real diesel has been studied using the complex [MoO2Cl2(4,4'-di-tert-butyl-2,2'-bipyridine)] as (pre)catalyst, aq. H2O2 as oxidant, and an ionic liquid as extraction solvent. Under moderate conditions (50 °C) and short reaction times (<3 h), dibenzothiophene, 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene could be completely removed from the model diesel. The (pre)catalyst 1 was transformed in situ to the active catalyst [MoO(O2)2(di-tBu-bipy)]. By sequentially performing extractive desulfurization and ECODS steps, 76% sulfur removal was achieved for a real diesel (Sinitial = 2300 ppm). For both the model and real diesels, the catalyst/IL phase could be easily recycled and reused with no loss of desulfurization efficiency.

Fast kinetics of chromatin assembly revealed by single-molecule videomicroscopy and scanning force microscopy

PubMed Central

Ladoux, Benoit; Quivy, Jean-Pierre; Doyle, Patrick; Roure, Olivia du; Almouzni, Geneviève; Viovy, Jean-Louis

2000-01-01

Fluorescence videomicroscopy and scanning force microscopy were used to follow, in real time, chromatin assembly on individual DNA molecules immersed in cell-free systems competent for physiological chromatin assembly. Within a few seconds, molecules are already compacted into a form exhibiting strong similarities to native chromatin fibers. In these extracts, the compaction rate is more than 100 times faster than expected from standard biochemical assays. Our data provide definite information on the forces involved (a few piconewtons) and on the reaction path. DNA compaction as a function of time revealed unique features of the assembly reaction in these extracts. They imply a sequential process with at least three steps, involving DNA wrapping as the final event. An absolute and quantitative measure of the kinetic parameters of the early steps in chromatin assembly under physiological conditions could thus be obtained. PMID:11114182

Cloning and characterization of an 11S legumin, Car i 4, a major allergen in pecan.

PubMed

Sharma, Girdhari M; Irsigler, Andre; Dhanarajan, Pushparani; Ayuso, Rosalia; Bardina, Luda; Sampson, Hugh A; Roux, Kenneth H; Sathe, Shridhar K

2011-09-14

Among tree nut allergens, pecan allergens remain to be identified and characterized. The objective was to demonstrate the IgE-binding ability of pecan 11S legumin and characterize its sequential IgE-binding epitopes. The 11S legumin gene was amplified from a pecan cDNA library and expressed as a fusion protein in Escherichia coli. The native 11S legumin in pecan extract was identified by mass spectrometry/mass spectrometry (MS/MS). Sequential epitopes were determined by probing the overlapping peptides with three serum pools prepared from different patients' sera. A three-dimensional model was generated using almond legumin as a template and compared with known sequential epitopes on other allergenic tree nut homologues. Of 28 patients tested by dot blot, 16 (57%) bound to 11S legumin, designated Car i 4. MS/MS sequencing of native 11S legumin identified 33 kDa acidic and 20-22 kDa basic subunits. Both pecan and walnut seed protein extracts inhibited IgE binding to recombinant Car i 4, suggesting cross-reactivity with Jug r 4. Sequential epitope mapping results of Car i 4 revealed weak, moderate, and strong reactivity of serum pools against 10, 5, and 4 peptides, respectively. Seven peptides were recognized by all three serum pools, of which two were strongly reactive. The strongly reactive peptides were located in three discrete regions of the Car i 4 acidic subunit sequence (residues 118-132, 208-219, and 238-249). Homology modeling of Car i 4 revealed significant overlapping regions shared in common with other tree nut legumins.

OPTIMIZING NIST SEQUENTIAL EXTRACTION METHOD FOR LAKE SEDIMENT (SRM4354)

EPA Science Inventory

Traditionally, measurements of radionuclides in the environment have focused on the determination of total concentration. It is clear, however, that total concentration does not describe the bioavailability of contaminating radionuclides. The environmental behavior depends on spe...

Assessing Metal Mobilization from Industrially Lead-Contaminated Soils Located at an Urban Site

EPA Science Inventory

A series of leaching and partitioning tests (Toxicity Characteristic Leaching Procedure (TCLP), Synthetic Precipitation Leaching Procedure (SPLP), Controlled Acidity Leaching Protocol (CALP), Acid Neutralization Capacity (ANC), and sequential extraction) were applied to three dif...

A sequential extraction and hydrolysis approach to understand the chemical nature of soil water repellency

NASA Astrophysics Data System (ADS)

Mao, Jiefei; Dekker, Stefan C.; Nierop, Klaas G. J.

2014-05-01

Soil water repellency (SWR) biomarkers (SWR-biomarkers) are defined as hydrophobic organic compounds in soils causing SWR and originating from vegetation or microbes (Doerr et al., 2000). Free lipids and ester-bound biopolymers (cutins and suberins) are usually seen in the aliphatic part of soil organic matter (SOM) (Nierop, 1998). The method of sequential extraction can divide hydrophobic compounds into individual fractions with different characteristics. We aim to find out the SWR-biomarkers in soils within different fractions, investigate the effects of fractions on SWR and link them to their original sources. To extract free and ester-bound lipids from sandy soils, DCM (dichloromethane)/MeOH (methanol) and IPA(isopropanol)/NH3 were used in sequential steps. As a result, three fractions were obtained during these sequential experiments: a DCM/MeOH soluble fraction (D), a DCM-MeOH soluble (AS) fraction of IPA/NH3 extracts and its insoluble (AI) fraction. To date, research was limited to (organic) extractable fractions only. To investigate the DCM-MeOH insoluble part of IPA/NH3 extracts they were depolymerised by trans-methylation using BF3-MeOH. All fractions were analysed by gas chromatography-mass spectrometry. After DCM/MeOH extraction, water repellency of 80% of the soils studied increased while SWR of the other soils remained at the same level. Straight-chain fatty acids, alcohols and alkanes were the main compound groups in the D fractions. The distribution of fatty acids (C20-C32) and alcohols (C20-C32), both of which with an even-over-odd predominance suggest their source were higher plants, and so did the odd-over-even predominated alkanes. After extraction by IPA/NH3 , most soils became non-repellent. Both fatty acids (C16-C32) and alcohols (C16-C30) with an even-over-odd predominance were also found in the AS fractions, whereas no alkanes were detected. There were four main component groups identified in the AI fractions: fatty acids, alcohols, ω-hydroxy fatty acids and α,ω-dicarboxylic acids. Aside from fatty acids and alcohols, the latter two compound groups were considered as the main groups of monomers released from suberins. Therefore, suberin-derived compounds were most abundant in the AI fractions suggesting that plant roots could be the main source of AI fractions. We will present some of the relations between fractions/compounds and SWR to show that this approach may be an effective tool to improve our understanding of SWR mechanisms. We present relations between fractions/compounds from SOM with SWR to determine SWR-biomarkers. By assessing the origin of these biomarkers, we are able to understand how SWR is formed and in which circumstances they are mainly from leaves or roots (i.e. cutin or suberin). References: Doerr, S.H., Shakesby, R.A., Walsh, R.P.D., 2000. Soil water repellency: its causes, characteristics and hydro- geomorphological significance. Earth-Sci. Rev. 51, 33-65. Nierop, K.G.J., 1998. Origin of aliphatic compounds in a forest soil. Organic Geochemistry 29, 1009-1016.

New seminal variety of Stevia rebaudiana: Obtaining fractions with high antioxidant potential of leaves.

PubMed

Milani, Paula G; Formigoni, Maysa; Dacome, Antonio S; Benossi, Livia; Costa, Cecília E M DA; Costa, Silvio C DA

2017-01-01

The aim of this study was to determine the composition and antioxidant potential of leaves of a new variety of Stevia rebaudiana (Stevia UEM-13). Stevia leaves of UEM-13 contain rebaudioside A as the main glycoside, while most wild Stevia plants contain stevioside. Furthermore can be multiplied by seed, which reduces the cost of plant culture techniques as other clonal varieties are multiplied by buds, requiring sophisticated and expensive seedling production systems. Ethanol and methanol were used in the extraction to determine the bioactive compounds. The methanolic extract was fractionated sequentially with hexane, chloroform, ethyl acetate and isobutanol, and the highest concentration of phenolic compounds and flavonoids was obtained in the ethyl acetate fraction (524.20 mg galic acid equivalent/g; 380.62 µg quercetin equivalent/g). The glycoside content varied greatly among the fractions (0.5% - 65.3%). Higher antioxidant potential was found in the methanol extract and the ethyl acetate fraction with 93.5% and 97.32%, respectively. In addition to being an excellent source for obtaining of extracts rich in glycoside, this new variety can also be used as raw material for the production of extracts or fractions with a significant amount of antioxidant activity and potential to be used as additives in food.

Learning Orthographic Structure With Sequential Generative Neural Networks.

PubMed

Testolin, Alberto; Stoianov, Ivilin; Sperduti, Alessandro; Zorzi, Marco

2016-04-01

Learning the structure of event sequences is a ubiquitous problem in cognition and particularly in language. One possible solution is to learn a probabilistic generative model of sequences that allows making predictions about upcoming events. Though appealing from a neurobiological standpoint, this approach is typically not pursued in connectionist modeling. Here, we investigated a sequential version of the restricted Boltzmann machine (RBM), a stochastic recurrent neural network that extracts high-order structure from sensory data through unsupervised generative learning and can encode contextual information in the form of internal, distributed representations. We assessed whether this type of network can extract the orthographic structure of English monosyllables by learning a generative model of the letter sequences forming a word training corpus. We show that the network learned an accurate probabilistic model of English graphotactics, which can be used to make predictions about the letter following a given context as well as to autonomously generate high-quality pseudowords. The model was compared to an extended version of simple recurrent networks, augmented with a stochastic process that allows autonomous generation of sequences, and to non-connectionist probabilistic models (n-grams and hidden Markov models). We conclude that sequential RBMs and stochastic simple recurrent networks are promising candidates for modeling cognition in the temporal domain. Copyright © 2015 Cognitive Science Society, Inc.

Associations of cadmium, zinc, and lead in soils from a lead and zinc mining area as studied by single and sequential extractions.

PubMed

Anju, M; Banerjee, D K

2011-05-01

An exploratory study of the area surrounding a historical Pb-Zn mining and smelting area in Zawar, India, detected significant contamination of the terrestrial environment by heavy metals. Soils (n=87) were analyzed for pH, EC, total organic matter (TOM), Pb, Zn, Mn, and Cd levels. The statistical analysis indicated that the frequency distribution of the analyzed parameters for these soils was not normal. The median concentrations of metals in surface soils were: Pb 420.21 μ g/g, Zn 870.25 μ g/g, Mn 696.70 μ g/g, and Cd 2.09 μ g/g. Zn concentrations were significantly correlated with Cd (r=0.867), indicating that levels of Cd are dependent on Zn. However, pH, electrical conductivity and total organic matter were not correlated significantly with Cd, Pb, Zn, and Mn. To assess the potential mobility of Cd, Pb, and Zn in soils, single (EDTA) as well as sequential extraction scheme (modified BCR) were applied to representative (n=23) soil samples. The amount of Cd, Pb, and Zn extracted by EDTA and their total concentrations showed linear positive correlation, which are statistically significant (r values for Cd, Pb, and Zn being 0.901, 0.971, and 0.795, respectively, and P values being <0.001). The correlation coefficients indicate a strong relation between EDTA-extractable metal and total metal. These results appear to justify the use of 'total' metal contents as a useful preliminary indicator of areas where the risks of metal excess or deficiency are high. The EDTA extractability was maximum for Cd followed by Pb and Zn in soils from all the locations. As indicated by single extraction, the apparent mobility and potential bioavailability of metals in soils followed the order: Cd ≥ Pb > > Zn. Soil samples were sequentially extracted (modified BCR) so that solid pools of Cd, Zn, and Pb could be partitioned into four operationally defined fractions viz. acid-soluble, reducible, oxidizable, and residual. Cadmium was present appreciably (39.41%) in the acid-soluble fraction and zinc was predominantly associated (32.42%) with residual fraction. Pb (66.86%) and Zn (30.44%) were present mainly in the reducible fraction. Assuming that the mobility and bioavailability are related to solubility of geochemical forms of metals and decrease in the order of extraction, the apparent mobility and potential metal bioavailability for these contaminated soil samples is Cd > Zn > Pb.

Sequential Extraction Results in Improved Proteome Profiling of Medicinal Plant Pinellia ternata Tubers, Which Contain Large Amounts of High-Abundance Proteins

PubMed Central

An, SuFang; Gong, FangPing; Wang, Wei

2012-01-01

Pinellia ternata tuber is one of the well-known Chinese traditional medicines. In order to understand the pharmacological properties of tuber proteins, it is necessary to perform proteome analysis of P. ternata tubers. However, a few high-abundance proteins (HAPs), mainly mannose-binding lectin (agglutinin), exist in aggregates of various sizes in the tubers and seriously interfere with proteome profiling by two-dimensional electrophoresis (2-DE). Therefore, selective depletion of these HAPs is a prerequisite for enhanced proteome analysis of P. ternata tubers. Based on differential protein solubility, we developed a novel protocol involving two sequential extractions for depletion of some HAPs and prefractionation of tuber proteins prior to 2-DE. The first extraction using 10% acetic acid selectively extracted acid-soluble HAPs and the second extraction using the SDS-containing buffer extracted remaining acid-insoluble proteins. After application of the protocol, 2-DE profiles of P. ternata tuber proteins were greatly improved and more protein spots were detected, especially low-abundance proteins. Moreover, the subunit composition of P. ternata lectin was analyzed by electrophoresis. Native lectin consists of two hydrogen-bonded subunits (11 kDa and 25 kDa) and the 11 kDa subunit was a glycoprotein. Subsequently, major HAPs in the tubers were analyzed by mass spectrometry, with nine protein spots being identified as lectin isoforms. The methodology was easy to perform and required no specialized apparatus. It would be useful for proteome analysis of other tuber plants of Araceae. PMID:23185632

Sequential extraction results in improved proteome profiling of medicinal plant Pinellia ternata tubers, which contain large amounts of high-abundance proteins.

PubMed

Wu, Xiaolin; Xiong, Erhui; An, Sufang; Gong, Fangping; Wang, Wei

2012-01-01

Pinellia ternata tuber is one of the well-known Chinese traditional medicines. In order to understand the pharmacological properties of tuber proteins, it is necessary to perform proteome analysis of P. ternata tubers. However, a few high-abundance proteins (HAPs), mainly mannose-binding lectin (agglutinin), exist in aggregates of various sizes in the tubers and seriously interfere with proteome profiling by two-dimensional electrophoresis (2-DE). Therefore, selective depletion of these HAPs is a prerequisite for enhanced proteome analysis of P. ternata tubers. Based on differential protein solubility, we developed a novel protocol involving two sequential extractions for depletion of some HAPs and prefractionation of tuber proteins prior to 2-DE. The first extraction using 10% acetic acid selectively extracted acid-soluble HAPs and the second extraction using the SDS-containing buffer extracted remaining acid-insoluble proteins. After application of the protocol, 2-DE profiles of P. ternata tuber proteins were greatly improved and more protein spots were detected, especially low-abundance proteins. Moreover, the subunit composition of P. ternata lectin was analyzed by electrophoresis. Native lectin consists of two hydrogen-bonded subunits (11 kDa and 25 kDa) and the 11 kDa subunit was a glycoprotein. Subsequently, major HAPs in the tubers were analyzed by mass spectrometry, with nine protein spots being identified as lectin isoforms. The methodology was easy to perform and required no specialized apparatus. It would be useful for proteome analysis of other tuber plants of Araceae.

Determination of the distribution and speciation of selenium in an argillaceous sample using chemical extractions and post-extractions analyses: application to the hydrogeological experimental site of Poitiers.

PubMed

Bassil, Joseph; Naveau, Aude; Bueno, Maïté; Di Tullo, Pamela; Grasset, Laurent; Kazpard, Véronique; Razack, Moumtaz

2016-05-01

To better understand selenium's dynamics in environmental systems, the present study aims to investigate selenium speciation and distribution in black argillaceous sediments, partially fulfilling karstic cavities into the Hydrogeological Experimental Site of Poitiers. These sediments are suspected to be responsible for selenium concentrations exceeding the European Framework Directive's drinking water limit value (10 μg L(-1)) in some specific wells. A combination of a sequential extractions scheme and single parallel extractions was thus applied on a representative argillaceous sample. Impacts of the extractions on mineral dissolution and organic matter mobilization were followed by quantifying major cations and total organic carbon (TOC) in the aqueous extracts. The nature of the released organic matter was characterized using thermochemolysis coupled with gas chromatography-mass spectrometry (GC-MS). About 10 % of selenium from the black argillaceous studied matrix could be defined as 'easily mobilizable' when the majority (around 70 %) revealed associated with the aliphatic and alkaline-soluble organic matter's fraction (about 20 %). In these fractions, selenium speciation was moreover dominated by oxidized species including a mixture of Se(VI) (20-30 %) and Se(IV) (70-80 %) in the 'easily mobilizable' fraction, while only Se(IV) was detected in alkaline-soluble organic matter fraction.

Automated solid-phase extraction hyphenated to voltammetry for the determination of quercetin using magnetic nanoparticles and sequential injection lab-on-valve approach.

PubMed

Wang, Yang; Wang, Lu; Tian, Tian; Hu, Xiaoya; Yang, Chun; Xu, Qin

2012-05-21

In this study, an automated sequential injection lab-on-valve (SI-LOV) system was designed for the on-line matrix removal and preconcentration of quercetin. Octadecyl functionalized magnetic silica nanoparticles were prepared and packed into the microcolumn of the LOV as adsorbents. After being adsorbed through hydrophobic interaction, the analyte was eluted and subsequently introduced into the electrochemical flow cell by voltammetric quantification. The main parameters affecting the performance of solid-phase extraction, such as sample pH and flow rate, eluent solution and volume, accumulation potential and accumulation time were investigated in detail. Under the optimum experimental conditions, a linear calibration curve was obtained in the range of 1.0 × 10(-8) to 1 × 10(-5) mol L(-1) with R(2) = 0.9979. The limit of detection (LOD) and limit of quantitation (LOQ) were 1.3 × 10(-9) and 4.3 × 10(-9) mol L(-1), respectively. The relative standard deviation (RSD) for the determination of 1.0 × 10(-6) mol L(-1) quercetin was found to be 2.9% (n = 11) along with a sampling frequency of 40 h(-1). The applicability and reliability of the automated method described here had been applied to the determination of quercetin in human urine and red wine samples through recovery experiments, and the obtained results were in good agreement with those obtained by the HPLC method.

A Centimeter-Scale Investigation of Geochemical Hotspots in a Soil Lysimeter

NASA Astrophysics Data System (ADS)

Umanzor, M.; Wang, Y.; Dontsova, K.; Chorover, J.; Troch, P. A. A.

2016-12-01

Studying the co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled Earth-system processes. Such knowledge is imperative for improving predictions of hydro-biogeochemical cycles, especially under climate change scenarios. Hotspots may form in porous media that is undergoing biogeochemical weathering at locations where reactants accumulate to threshold values along hydrologic flow paths. This is expected to occur in weatherable silicate media, like granular basalt. To examine such processes during incipient soil formation, we constructed a sloping weighing lysimeter 2-m in length, 0.5-m in width and 1-m in depth. Mini-LEO was filled with crushed granular basalt rock with a known initial chemical composition. After 18 months of irrigation and intensive hydrological study, the model "landscape" was divided into a 3D matrix of 324 voxels and excavated. Collected samples were subjected to detailed hydro-bio-geochemical analysis to assess the formation of geochemical heterogeneity. A five-step sequential extraction was employed to characterize incongruent mineral weathering, and its relation to the spatial distribution of microbial composition (in a related study). The changes in Fe and Mn concentration and speciation along the lysimeter length and depth (as measured by each step of the sequential extraction) was quantified to characterize spatial distribution of weathering processes. Results are being used to assist in understanding not only spatial and temporal distribution of basalt weathering on the slope, but also, connections between hydrological and biogeochemical cycles that lead to formation of hotspots.

The removal of heavy metals from contaminated soil by a combination of sulfidisation and flotation.

PubMed

Vanthuyne, Mathias; Maes, André

2002-05-06

The possibility of removing cadmium, copper, lead and zinc from Belgian loamy soil by a combination of sulfidisation pre-treatment and Denver flotation was investigated. The potentially available--sulfide convertible--metal content of the metal polluted soil was estimated by EDTA (0.1 M, pH 4.65) extraction and BCR sequential extraction. EDTA extraction is better at approximating the metal percentage that is expected to be convertible into a metal sulfide phase, in contrast to the sequential extraction procedure of 'Int. J. Environ. Anal. Chem. 51 (1993) pp. 135-151' in which transition metals present as iron oxide co-precipitates are dissolved by hydroxylammoniumchloride in the second extraction step. To compare the surface characteristics of metal sulfides formed by sulfidisation with those of crystalline metal sulfides, two types of synthetic sediments were prepared and extracted with 0.1 M EDTA (pH 4.65) in anoxic conditions. Separate metal sulfides or co-precipitates with iron sulfide were formed by sulfide conditioning. The Denver flotation of both types of synthetic sediments (kerosene as collector at high background electrolyte concentrations) resulted in similar concentrating factors for freshly formed metal sulfides as for fine-grained crystalline metal sulfides. The selective flotation of metal sulfides after sulfide conditioning of a polluted soil, using kerosene or potassium ethyl xanthate as collectors and MIBC as frother, was studied at high background electrolyte concentrations. The sulfidisations were made in ambient air and inside an anoxic glove box. The concentrating factors corrected by the potentially available metal percentage, determined by 0.1 M EDTA extraction, lie between 2 and 3. The selective flotation of these finely dispersed, amorphous, metal sulfides can possibly be improved by optimising the bubble-particle interaction.

Antiplasmodial activity of extracts of Tridax procumbens and Phyllanthus amarus in in vitro Plasmodium falciparum culture systems.

PubMed

Appiah-Opong, R; Nyarko, A K; Dodoo, D; Gyang, F N; Koram, K A; Ayisi, N K

2011-12-01

Aqueous extracts of Tridax procumbens (TP) (Compositae) and Phyllanthus amarus (PA) (Euphorbiaceae) are used in traditional medicine in Ghana to treat malaria. Previous studies have demonstrated the anti-trypanosoma, anti-bacterial and anti-HIV effects of TP and PA. To assess the antiplasmodial activity of extracts of TP and PA. Aqueous extracts of TP and PA were prepared. A portion of each was freeze-dried and the remaining extracted sequentially with ethyl acetate and chloroform. Ethanolic extracts were also prepared. The antiplasmodial activity of the extracts was assessed with the 3H-hypoxanthine assay using chloroquine-resistant (Dd2) Plasmodium falciparum parasites. Chloroquine was used as the reference drug. The modified tetrazolium-based colorimetric assay was also used to evaluate the red blood cell (RBC)-protective/antiplasmodial activities and cytotoxicities of the extracts. Results showed that TP and PA have antiplasmodial activities. The aqueous and ethanolic extracts of PA were the most active, yielding EC50 values of 34.9 µg/ml and 31.2 µg/ml, respectively in the tetrazolium-based assay. The TP and PA produced and IC50 values of 24.8 µg/ml and 11.7 µg/ml, respectively in the hypoxanthine assay. Protection of human RBCs against P. falciparum damage by the extracts highly correlated with their antiplasmodial activities. None of the extracts, within the concentration range (1.9-500 µg/ml) studied produced any overt toxicity to human RBCs. The results indicate that both PA and TP have activities against chloroquine-resistant P. falciparum (Dd2) parasites. The antiplasmodial principles extracted into water and ethanol but not chloroform or ethyl acetate.

In vitro functional properties of crude extracts and isolated compounds from banana pseudostem and rhizome.

PubMed

Kandasamy, Saravanan; Ramu, Sasikala; Aradhya, Somaradhya Mallikarjuna

2016-03-15

Pseudostem and rhizome are the significant bio-waste generated (43.48%) from the banana plant post fruit harvest, which are usually left in the plantation or incinerated and wasted. Amounts used in production for consumption are negligible. However, the material has an important part to play in indigenous systems of medicine. Based on the huge volume of bio-waste generated and its traditional medicinal use, it is worth exploiting it as a source of natural bioactive compounds. In the current study, sequential extracts from banana pseudostem (BPS) and rhizome (BR), and isolated compounds including chlorogenic acid, 4-epicyclomusalenone and cycloeucalenol acetate, were tested for their antimicrobial activity, antiplatelet aggregation and cytotoxicity. Isolated compounds and crude extracts exhibited strong antimicrobial activity against a wide range of bacterial and fungal strains, platelet aggregation induced by collagen and cytotoxicity towards human liver cancer (HepG2) cells. Banana plant bio-waste, pseudostem and rhizome may serve as a potential source of multifunctional bioactive compounds and functional ingredient in food and other allied industries. © 2015 Society of Chemical Industry.

MaPLE: A MapReduce Pipeline for Lattice-based Evaluation and Its Application to SNOMED CT

PubMed Central

Zhang, Guo-Qiang; Zhu, Wei; Sun, Mengmeng; Tao, Shiqiang; Bodenreider, Olivier; Cui, Licong

2015-01-01

Non-lattice fragments are often indicative of structural anomalies in ontological systems and, as such, represent possible areas of focus for subsequent quality assurance work. However, extracting the non-lattice fragments in large ontological systems is computationally expensive if not prohibitive, using a traditional sequential approach. In this paper we present a general MapReduce pipeline, called MaPLE (MapReduce Pipeline for Lattice-based Evaluation), for extracting non-lattice fragments in large partially ordered sets and demonstrate its applicability in ontology quality assurance. Using MaPLE in a 30-node Hadoop local cloud, we systematically extracted non-lattice fragments in 8 SNOMED CT versions from 2009 to 2014 (each containing over 300k concepts), with an average total computing time of less than 3 hours per version. With dramatically reduced time, MaPLE makes it feasible not only to perform exhaustive structural analysis of large ontological hierarchies, but also to systematically track structural changes between versions. Our change analysis showed that the average change rates on the non-lattice pairs are up to 38.6 times higher than the change rates of the background structure (concept nodes). This demonstrates that fragments around non-lattice pairs exhibit significantly higher rates of change in the process of ontological evolution. PMID:25705725

MaPLE: A MapReduce Pipeline for Lattice-based Evaluation and Its Application to SNOMED CT.

PubMed

Zhang, Guo-Qiang; Zhu, Wei; Sun, Mengmeng; Tao, Shiqiang; Bodenreider, Olivier; Cui, Licong

2014-10-01

Non-lattice fragments are often indicative of structural anomalies in ontological systems and, as such, represent possible areas of focus for subsequent quality assurance work. However, extracting the non-lattice fragments in large ontological systems is computationally expensive if not prohibitive, using a traditional sequential approach. In this paper we present a general MapReduce pipeline, called MaPLE (MapReduce Pipeline for Lattice-based Evaluation), for extracting non-lattice fragments in large partially ordered sets and demonstrate its applicability in ontology quality assurance. Using MaPLE in a 30-node Hadoop local cloud, we systematically extracted non-lattice fragments in 8 SNOMED CT versions from 2009 to 2014 (each containing over 300k concepts), with an average total computing time of less than 3 hours per version. With dramatically reduced time, MaPLE makes it feasible not only to perform exhaustive structural analysis of large ontological hierarchies, but also to systematically track structural changes between versions. Our change analysis showed that the average change rates on the non-lattice pairs are up to 38.6 times higher than the change rates of the background structure (concept nodes). This demonstrates that fragments around non-lattice pairs exhibit significantly higher rates of change in the process of ontological evolution.

Mercury Speciation by X-ray Absorption Fine Structure Spectroscopy and Sequential Chemical Extractions: A Comparison of Speciation Methods

USGS Publications Warehouse

Kim, C.S.; Bloom, N.S.; Rytuba, J.J.; Brown, Gordon E.

2003-01-01

Determining the chemical speciation of mercury in contaminated mining and industrial environments is essential for predicting its solubility, transport behavior, and potential bioavailability as well as for designing effective remediation strategies. In this study, two techniques for determining Hg speciation-X-ray absorption fine structure (XAFS) spectroscopy and sequential chemical extractions (SCE)-are independently applied to a set of samples with Hg concentrations ranging from 132 to 7539 mg/kg to determine if the two techniques provide comparable Hg speciation results. Generally, the proportions of insoluble HgS (cinnabar, metacinnabar) and HgSe identified by XAFS correlate well with the proportion of Hg removed in the aqua regia extraction demonstrated to remove HgS and HgSe. Statistically significant (> 10%) differences are observed however in samples containing more soluble Hg-containing phases (HgCl2, HgO, Hg3S2O 4). Such differences may be related to matrix, particle size, or crystallinity effects, which could affect the apparent solubility of Hg phases present. In more highly concentrated samples, microscopy techniques can help characterize the Hg-bearing species in complex multiphase natural samples.

Iodine speciation in coastal and inland bathing waters and seaweeds extracts using a sequential injection standard addition flow-batch method.

PubMed

Santos, Inês C; Mesquita, Raquel B R; Bordalo, Adriano A; Rangel, António O S S

2015-02-01

The present work describes the development of a sequential injection standard addition method for iodine speciation in bathing waters and seaweeds extracts without prior sample treatment. Iodine speciation was obtained by assessing the iodide and iodate content, the two inorganic forms of iodine in waters. For the determination of iodide, an iodide ion selective electrode (ISE) was used. The indirect determination of iodate was based on the spectrophotometric determination of nitrite (Griess reaction). For the iodate measurement, a mixing chamber was employed (flow batch approach) to explore the inherent efficient mixing, essential for the indirect determination of iodate. The application of the standard addition method enabled detection limits of 0.14 µM for iodide and 0.02 µM for iodate, together with the direct introduction of the target water samples, coastal and inland bathing waters. The results obtained were in agreement with those obtained by ICP-MS and a colorimetric reference procedure. Recovery tests also confirmed the accuracy of the developed method which was effectively applied to bathing waters and seaweed extracts. Copyright © 2014 Elsevier B.V. All rights reserved.

Multispectral image alignment using a three channel endoscope in vivo during minimally invasive surgery

PubMed Central

Clancy, Neil T.; Stoyanov, Danail; James, David R. C.; Di Marco, Aimee; Sauvage, Vincent; Clark, James; Yang, Guang-Zhong; Elson, Daniel S.

2012-01-01

Sequential multispectral imaging is an acquisition technique that involves collecting images of a target at different wavelengths, to compile a spectrum for each pixel. In surgical applications it suffers from low illumination levels and motion artefacts. A three-channel rigid endoscope system has been developed that allows simultaneous recording of stereoscopic and multispectral images. Salient features on the tissue surface may be tracked during the acquisition in the stereo cameras and, using multiple camera triangulation techniques, this information used to align the multispectral images automatically even though the tissue or camera is moving. This paper describes a detailed validation of the set-up in a controlled experiment before presenting the first in vivo use of the device in a porcine minimally invasive surgical procedure. Multispectral images of the large bowel were acquired and used to extract the relative concentration of haemoglobin in the tissue despite motion due to breathing during the acquisition. Using the stereoscopic information it was also possible to overlay the multispectral information on the reconstructed 3D surface. This experiment demonstrates the ability of this system for measuring blood perfusion changes in the tissue during surgery and its potential use as a platform for other sequential imaging modalities. PMID:23082296

Characterization of trace metal removal products in vertical flow bioreactor substrates at the Mayer Ranch Passive Treatment System in the Tar Creek Superfund Site.

PubMed

LaBar, Julie A; Nairn, Robert W

2018-05-01

A passive treatment system (PTS), including two parallel vertical flow bioreactors (VFBR), was constructed in 2008 for the treatment of unabated net-alkaline ferruginous mine drainage in the Tar Creek Superfund Site in northeastern Oklahoma. Water quality data collected since the PTS began operation indicate significant removal of trace metals in the VFBR. Results of a sequential extraction procedure (SEP) performed on substrate samples showed that the majority of Cd, Co, Fe, Ni, Pb, and Zn were retained in the refractory organic/sulfide fraction. Subsequent acid volatile sulfide/simultaneously extracted metals (AVS/SEM) analyses confirmed the retention of Cd, Fe, Pb, and Zn as sulfides, but Co and Ni results were less certain. The majority of trace metals were retained as insoluble products in the VFBR, while up to 20% of most of the trace metals were retained in soluble, bioavailable fractions. Nearly 70% of Mn was retained in the soluble and bioavailable exchangeable, carbonate, and labile organic fractions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Probabilistic Seeking Prediction in P2P VoD Systems

NASA Astrophysics Data System (ADS)

Wang, Weiwei; Xu, Tianyin; Gao, Yang; Lu, Sanglu

In P2P VoD streaming systems, user behavior modeling is critical to help optimise user experience as well as system throughput. However, it still remains a challenging task due to the dynamic characteristics of user viewing behavior. In this paper, we consider the problem of user seeking prediction which is to predict the user's next seeking position so that the system can proactively make response. We present a novel method for solving this problem. In our method, frequent sequential patterns mining is first performed to extract abstract states which are not overlapped and cover the whole video file altogether. After mapping the raw training dataset to state transitions according to the abstract states, we use a simpel probabilistic contingency table to build the prediction model. We design an experiment on the synthetic P2P VoD dataset. The results demonstrate the effectiveness of our method.

Application of EDTA decontamination on soils affected by mining activities and impact of treatment on the geochemical partition of metal contaminants.

PubMed

Xia, Wenbin; Gao, Hui; Wang, Xianhai; Zhou, Chunhua; Liu, Yunguo; Fan, Ting; Wang, Xin

2009-05-30

Two soil samples were collected at mining areas located in southern Hunan Province, China. EDTA extraction of Pb, Zn, Cu and Cd from these two tailing soils was studied using column leaching experiments. The redistributions of heavy metals (HMs) were determined using the modified BCR (Community Bureau of Reference) sequential extraction procedure, before and after EDTA extraction. The results indicated that EDTA was an effective extractant because of its strong chelating ability for various HMs. The proportions of Pb, Zn, Cu and Cd in the four fractions varied largely after EDTA extraction. The extraction efficiency of EDTA of the acid-extractable fraction (AEX) was significant in shallow soil column, while in deeper soil column, decrease of the extraction efficiency of reduced (RED), oxidizable (OX) and residual fractions (RES) was obtained, which was mainly due to the decrease of EDTA concentration.

Dillenia suffruticosa exhibited antioxidant and cytotoxic activity through induction of apoptosis and G2/M cell cycle arrest.

PubMed

Armania, Nurdin; Yazan, Latifah Saiful; Musa, Siti Noorhidayah; Ismail, Intan Safinar; Foo, Jhi Biau; Chan, Kim Wei; Noreen, Husain; Hisyam, Abdul Hamid; Zulfahmi, Said; Ismail, Maznah

2013-03-27

Dillenia suffruticosa (Family: Dilleniaceae) locally known as Simpoh air has been reported to be used traditionally to treat cancerous growth. Therefore, the present study was attempted to investigate the antioxidant and cytotoxic properties of different parts (root, flower, fruit and leaf) of D. suffruticosa extracts. In this study, direct solvent extraction (aqueous and methanol) from different parts of D. suffruticosa (root, flower, fruit and leaf) were carried out. Antioxidant activities of D. suffruticosa extract were determined by using DPPH, ABTS FRAP and β-carotene bleaching assays. Cytotoxicity and cell cycle arrest of the active extract were determined using MTT assay and flow cytometer, respectively. Sequential solvent extraction (hexane, DCM, EtOAc, and MeOH) were also carried out in root of D. suffruticosa to further evaluate the antioxidant and cytotoxic activity of the different solvent extracts. Methanol (MeOH) root extract showed the highest TPC, antioxidant and cytotoxic activities (especially towards HeLa) compared to others (P<0.05). Based on the results, sequential solvent extraction (hexane, DCM, EtOAc and MeOH) was carried out in the roots of D. suffruticosa. MeOH extract exhibited the highest antioxidant activities among others and significantly correlated (P<0.05) with TPC, suggesting the important contribution of phenolic compounds to its antioxidant activity. On the other hand, the DCM and EtOAc exhibited higher cytotoxic activity to selected cancer cells (HeLa, MCF-7, MDA-MB-231, A549 and HT29) compared to others. In short, there is no established correlation between antioxidant and cytotoxic activities of D. suffruticosa extracts indicating that an agent with high antioxidant activities will not necessarily possesses good cytotoxic activities in return. Qualitative phytochemical screening of D. suffruticosa extracts suggested the presence of saponins, triterpenes, sterols, and polyphenolic compounds which are believed to contribute to the cytotoxic activities. It is suggested that the cytotoxicity of the active extracts in HeLa was due to the induction of apoptosis and cell cycle arrest at G2/M. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Evaluation of Phosphate Fertilizers for the Immobilization of Cd in Contaminated Soils

PubMed Central

Yan, Yin; Zhou, Yi Qun; Liang, Cheng Hua

2015-01-01

A laboratory investigation was conducted to evaluate the efficiency of four phosphate fertilizers, including diammonium phosphate (DAP), potassium phosphate monobasic (MPP), calcium superphosphateon (SSP), and calcium phosphate tribasic (TCP), in terms of the toxicity and bioavailability of Cd in contaminated soils. The efficiency of immobilization was evaluated on the basis of two criteria: (a) the reduction of extractable Cd concentration below the TCLP regulatory level and (b) the Cd changes associated with specific operational soil fractions on the basis of sequential extraction data. Results showed that after 50 d immobilization, the extractable concentrations of Cd in DAP, MPP, SSP, and TCP treated soils decreased from 42.64 mg/kg (in the control) to 23.86, 21.86, 33.89, and 35.59 mg/kg, respectively, with immobilization efficiency in the order of MPP > DAP > SSP > TCP. Results from the assessment of Cd speciation via the sequential extraction procedure revealed that the soluble exchangeable fraction of Cd in soils treated with phosphate fertilizers, especially TCP, was considerably reduced. In addition, the reduction was correspondingly related to the increase in the more stable forms of Cd, that is, the metal bound to manganese oxides and the metal bound to crystalline iron oxides. Treatment efficiency increased as the phosphate dose (according to the molar ratio of PO4/Cd) increased. Immobilization was the most effective under the molar ratio of PO4/Cd at 4:1. PMID:25915051

Chemical and physiological metal bioaccessibility assessment in surface bottom sediments from the Deba River urban catchment: Harmonization of PBET, TCLP and BCR sequential extraction methods.

PubMed

Unda-Calvo, Jessica; Martínez-Santos, Miren; Ruiz-Romera, Estilita

2017-04-01

In the present study, the physiologically based extraction test PBET (gastric and intestinal phases) and two chemical based extraction methods, the toxicity characteristic leaching procedure (TCLP) and the sequential extraction procedure BCR 701 (Community Bureau of Reference of the European Commission) have been used to estimate and evaluate the bioaccessibility of metals (Fe, Mn, Zn, Cu, Ni, Cr and Pb) in sediments from the Deba River urban catchment. The statistical analysis of data and comparison among physiological and chemical methods have highlighted the relevance of simulate the gastrointestinal tract environment since metal bioaccessibility seems to depend on water and sediment properties such as pH, redox potential and organic matter content, and, primordially, on the form in which metals are present in the sediment. Indeed, metals distributed among all fractions (Mn, Ni, Zn) were the most bioaccessible, followed by those predominantly bound to oxidizable fraction (Cu, Cr and Pb), especially near major urban areas. Finally, a toxicological risk assessment was also performed by determining the hazard quotient (HQ), which demonstrated that, although sediments from mid- and downstream sampling points presented the highest metal bioaccessibilities, were not enough to have adverse effects on human health, Cr being the most potentially toxic element. Copyright © 2017 Elsevier Inc. All rights reserved.

Extraction and speciation of arsenic in lacustrine sediments

USGS Publications Warehouse

Ficklin, W.H.

1990-01-01

Arsenic was partially extracted with 4.OM hydrochloric acid, from samples collected at 25-cm intervals in a 350-cm column of sediment at Milltown Reservoir, Montana and from a 60-cm core of sediment collected at the Cheyenne River Embayment of Lake Oahe, South Dakota. The sediment in both reservoirs is highly contaminated with arsenic. The extracted arsenic was separated into As(III) and As(V) on acetate form Dowex 1-X8 ion-exchange resin with 0.12M HCl eluent. Residual arsenic was sequentially extracted with KClO3 and HCl. Arsenic was determined by graphite-furnace atomic-absorption spectrometry. The analytical results define oxidized and reduced zones in the sediment columns. ?? 1990.

Pollution potential leaching index as a tool to assess water leaching risk of arsenic in excavated urban soils.

PubMed

Li, Jining; Kosugi, Tomoya; Riya, Shohei; Hashimoto, Yohey; Hou, Hong; Terada, Akihiko; Hosomi, Masaaki

2018-01-01

Leaching of hazardous trace elements from excavated urban soils during construction of cities has received considerable attention in recent years in Japan. A new concept, the pollution potential leaching index (PPLI), was applied to assess the risk of arsenic (As) leaching from excavated soils. Sequential leaching tests (SLT) with two liquid-to-solid (L/S) ratios (10 and 20Lkg -1 ) were conducted to determine the PPLI values, which represent the critical cumulative L/S ratios at which the average As concentrations in the cumulative leachates are reduced to critical values (10 or 5µgL -1 ). Two models (a logarithmic function model and an empirical two-site first-order leaching model) were compared to estimate the PPLI values. The fractionations of As before and after SLT were extracted according to a five-step sequential extraction procedure. Ten alkaline excavated soils were obtained from different construction projects in Japan. Although their total As contents were low (from 6.75 to 79.4mgkg -1 ), the As leaching was not negligible. Different L/S ratios at each step of the SLT had little influence on the cumulative As release or PPLI values. Experimentally determined PPLI values were in agreement with those from model estimations. A five-step SLT with an L/S of 10Lkg -1 at each step, combined with a logarithmic function fitting was suggested for the easy estimation of PPLI. Results of the sequential extraction procedure showed that large portions of more labile As fractions (non-specifically and specifically sorbed fractions) were removed during long-term leaching and so were small, but non-negligible, portions of strongly bound As fractions. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of chemical pollution on forms of 137Cs, 90Sr and 239,240Pu in arctic soil studied by sequential extraction.

PubMed

Puhakainen, M; Riekkinen, I; Heikkinen, T; Jaakkola, T; Steinnes, E; Rissanen, K; Suomela, M; Thørring, H

2001-01-01

The aim of the present study was to determine the forms of 137Cs, 90Sr and 239,240Pu occurring in different soil horizons using sequential extraction of samples taken from four sites located along a pollution gradient from the copper-nickel smelter at Monchegorsk in the Kola Peninsula, Russia, and from a reference site in Finnish Lapland in 1997. A selective sequential-leaching procedure was employed using a modification of the method of Tessier, Cambell and Bisson ((1979). Analytical Chemistry, 51, 844-851). For 137Cs the organic (O) and uppermost mineral (E1) layer were studied, for 90Sr and 239,240Pu only the uppermost organic layer (Of). The fraction of 137Cs occurring in readily exchangeable form in the organic layer was about 50% at the reference site and decreased as a function of pollution, being 15% at the most polluted site in the Kola Peninsula. There was a clear positive correlation in the O layer between the distance from the smelter and the percentage of 137Cs extracted in the readily exchangeable fraction (Spearman correlation rsp = 0.7805, p = 0.0001), whereas in the E1 layer no correlation was evident. The distribution of 90Sr in the Of layer was similar at all sites, with the highest amounts occurring in exchangeable form and bound to organic matter, whereas stable Sr showed a somewhat different distribution with the highest amount in the oxide fraction. Most of the 239,240Pu was bound to organic matter. Chemical pollution affected the exchangeable fraction of 239,240Pu, which was about 1% at the most polluted site and 4-6% at the other sites.

A sequential analysis of classroom discourse in Italian primary schools: the many faces of the IRF pattern.

PubMed

Molinari, Luisa; Mameli, Consuelo; Gnisci, Augusto

2013-09-01

A sequential analysis of classroom discourse is needed to investigate the conditions under which the triadic initiation-response-feedback (IRF) pattern may host different teaching orientations. The purpose of the study is twofold: first, to describe the characteristics of classroom discourse and, second, to identify and explore the different interactive sequences that can be captured with a sequential statistical analysis. Twelve whole-class activities were video recorded in three Italian primary schools. We observed classroom interaction as it occurs naturally on an everyday basis. In total, we collected 587 min of video recordings. Subsequently, 828 triadic IRF patterns were extracted from this material and analysed with the programme Generalized Sequential Query (GSEQ). The results indicate that classroom discourse may unfold in different ways. In particular, we identified and described four types of sequences. Dialogic sequences were triggered by authentic questions, and continued through further relaunches. Monologic sequences were directed to fulfil the teachers' pre-determined didactic purposes. Co-constructive sequences fostered deduction, reasoning, and thinking. Scaffolding sequences helped and sustained children with difficulties. The application of sequential analyses allowed us to show that interactive sequences may account for a variety of meanings, thus making a significant contribution to the literature and research practice in classroom discourse. © 2012 The British Psychological Society.

Assessment of a sequential extraction protocol by examining solution chemistry and mineralogical evolution

NASA Astrophysics Data System (ADS)

Maubec, Nicolas; Pauwels, Hélène; Noël, Hervé; Bourrat, Xavier

2015-04-01

Knowledge of the behavior of heavy metals, such as copper and zinc in sediments, is a key factor to improve the management of rivers. The mobility of these metals, which may be harmful to the environment, depends directly on their concentration and speciation , which in turn depend on physico-chemical parameters such as mineralogy of the sediment fraction, pH, redox potential, salinity etc ... (Anderson et al., 2000; Sterckeman et al., 2004; Van Oort et al., 2008). Several methods based on chemical extractions are currently applied to assess the behavior of heavy metals in soils and sediments. Among them, sequential extraction procedure is widely used in soil and sediment science and provides details about the origin, biological and physicochemical availability, mobilization and transports of trace metals elements. It is based on the use of a series of extracting reagents to extract selectively heavy metals according to their association within the solid phase (Cornu and Clozel, 2000) including the following different fraction : exchangeable, bound to carbonates, associated to oxides (reducible fraction), linked to organic matter and sulfides (oxidizable fraction) as well as silicate minerals so called residual fraction (Hickey and Kittrick, 1984; Tessier et al., 1979). Consequently sequential extraction method is expected to simulate a lot of potential natural and anthropogenic modifications of environmental conditions (Arey et al., 1999; Brannon and Patrick, 1987; Hickey and Kittrick, 1984; La Force et al., 1999; Tessier et al., 1979). For three decades, a large number of protocols has been proposed, characterized by specific reagents and experimental conditions (concentrations, number of steps, extraction orders and solid/solution ratio) (Das et al., 1995; Gomez Ariza et al., 2000; Quevauviller et al., 1994; Rauret, 1998; Tack and Verloo, 1995), but it appeared that several of them suffer from a lack of selectivity of applied reagents: besides target ones, some of them are able to leach several solid phases. In this context, the aim of the present study is to investigate the effectiveness and the selectivity of different reagents for metal extraction from target geochemical fraction. It is based on solid analyses with the use of X-ray diffraction and a scanning electron microscopy (SEM) coupled to a microRaman spectrometer in conjunction with chemical analyses of extracting solutions at each step. This methodology provides the opportunity to assess more accurately the effect of each reagent. The study focuses on extraction of Cu and Zn from sediment samples collected at two sites from river banks and characterized by presence of Quartz, Feldspar K, Micas, Kaolinite but with differences regarding accessory phases (pyrite, organic matter, iron oxy- hydroxide, calcite). The interaction of the samples with eight different reagents was assessed and compared (Ca(NO3)2 and CaCl2 for the exchangeable fraction; buffered solutions of sodium acetate/acetic acid at pH = 5.5 and pH = 5 for the acido-soluble fraction; hydroxylamine hydrochloride and a solution of ammonium oxalate/oxalic acid for reducible fraction; hydrogen peroxide and sodium hypochlorite for the oxidizable fraction. In-depth characterization of solid residue at each step allowed proposing the best protocol for both metals. Anderson, P., Davidson, C. M., Duncan, A. L., Littlejohn, D., Ure, A. M., and Garden, L. M. (2000). Column leaching and sorption experiments to assess the mobility of potentially toxic elements in industrially contaminated land. Journal of Environmental Monitoring, 2. Arey, J. S., Seaman, J. C., and Bertsch, P. M. (1999). Immobilization of uranium in contaminated sediments by hydroxyapatite addition. Environmental Science & Technology, 33, 337-342. Brannon, J. M., and Patrick, W. H. (1987). Fixation, transformation, and mobilization of arsenic in sediments.Environmental Science & Technology, 21, 450-459. Cornu, S., and Clozel, B. (2000). Extractions séquentielles et spéciation des éléments trace métalliques dans les sols naturels. Analyse critique. 7, 179-189. Das, A. K., Chakraborty, R., Cervera, M. L., and Delaguardia, M. (1995). Metal speciation in solid matrices. Talanta, 42. Gomez Ariza, J. L., Giraldez, I., Sanchez-Rodas, D., and Morales, E. (2000). Selectivity assessment of a sequential extraction procedure for metal mobility characterization using model phases. Talanta, 52, 545-554. Hickey, M. G., and Kittrick, J. A. (1984). Chemical partitioning of cadmium, copper, nickel and zinc in soils and sediments containing high-levels of heavy metals. Journal of Environmental Quality, 13, 372-376. La Force, M. J., Fendorf, S., Li, G. C., and Rosenzweig, R. F. (1999). Redistribution of trace elements from contaminated sediments of Lake Coeur d'Alene during oxygenation. Journal of Environmental Quality, 28, 1195-1200. Quevauviller, P., Rauret, G., Muntau, H., Ure, A. M., Rubio, R., Lopezsanchez, J. F., Fiedler, H. D., and Griepink, B. (1994). Evaluation of a sequential extraction procedure for the determination of extractable trace-metal contents in sediments. Fresenius Journal of Analytical Chemistry, 349. Rauret, G. (1998). Extraction procedures for the determination of heavy metals in contaminated soil and sediment. Talanta, 46(3), 449-455. Sterckeman, T., Douay, F., Baize, D., Fourrier, H., Proix, N., and Schvartz, C. (2004). Factors affecting trace element concentrations in soils developed on recent marine deposits from northern France. Applied Geochemistry, 19. Tack, F. M. G., and Verloo, M. G. (1995). Chemical speciation and fraéctination in soil and sediment heavy-metal analysis - a review. International Journal of Environmental Analytical Chemistry, 59, 225-238. Tessier, A., Campbell, P. G. C., and Bisson, M. (1979). Sequential extraction procedure for the speciation of particulate trace-metals. Analytical Chemistry, 51. Van Oort, F., Jongmans, A. G., Lamy, I., Baize, D., and Chevallier, P. (2008). Impacts of long-term waste-water irrigation on the development of sandy Luvisols: consequences for metal pollutant distributions. European Journal of Soil Science, 59.

Developing a Self-Report-Based Sequential Analysis Method for Educational Technology Systems: A Process-Based Usability Evaluation

ERIC Educational Resources Information Center

Lin, Yi-Chun; Hsieh, Ya-Hui; Hou, Huei-Tse

2015-01-01

The development of a usability evaluation method for educational systems or applications, called the self-report-based sequential analysis, is described herein. The method aims to extend the current practice by proposing self-report-based sequential analysis as a new usability method, which integrates the advantages of self-report in survey…

A sequential adaptation technique and its application to the Mark 12 IFF system

NASA Astrophysics Data System (ADS)

Bailey, John S.; Mallett, John D.; Sheppard, Duane J.; Warner, F. Neal; Adams, Robert

1986-07-01

Sequential adaptation uses only two sets of receivers, correlators, and A/D converters which are time multiplexed to effect spatial adaptation in a system with (N) adaptive degrees of freedom. This technique can substantially reduce the hardware cost over what is realizable in a parallel architecture. A three channel L-band version of the sequential adapter was built and tested for use with the MARK XII IFF (identify friend or foe) system. In this system the sequentially determined adaptive weights were obtained digitally but implemented at RF. As a result, many of the post RF hardware induced sources of error that normally limit cancellation, such as receiver mismatch, are removed by the feedback property. The result is a system that can yield high levels of cancellation and be readily retrofitted to currently fielded equipment.

Mining sequential patterns for protein fold recognition.

PubMed

Exarchos, Themis P; Papaloukas, Costas; Lampros, Christos; Fotiadis, Dimitrios I

2008-02-01

Protein data contain discriminative patterns that can be used in many beneficial applications if they are defined correctly. In this work sequential pattern mining (SPM) is utilized for sequence-based fold recognition. Protein classification in terms of fold recognition plays an important role in computational protein analysis, since it can contribute to the determination of the function of a protein whose structure is unknown. Specifically, one of the most efficient SPM algorithms, cSPADE, is employed for the analysis of protein sequence. A classifier uses the extracted sequential patterns to classify proteins in the appropriate fold category. For training and evaluating the proposed method we used the protein sequences from the Protein Data Bank and the annotation of the SCOP database. The method exhibited an overall accuracy of 25% in a classification problem with 36 candidate categories. The classification performance reaches up to 56% when the five most probable protein folds are considered.

Efficacy of chlorhexidine, dexpanthenol, allantoin and chitosan gel in comparison with bicarbonate oral rinse in controlling post-interventional inflammation, pain and cicatrization in subjects undergoing dental surgery.

PubMed

Lopez-Lopez, Jose; Lope-Lopez, Jose; Jan-Pallí, Enric; lez-Navarro, Beatriz Gonzá; González-Navarro, Beatriz; Jané-Salas, Enric; Estrugo-Devesa, Albert; Milani, Massimo

2015-12-01

Reducing post-interventional inflammation and pain in odontostomatological surgery procedures, such as tooth extractions, implants or oral biopsies is a relevant clinical goal. Chlorhexidine oral rinse is commonly used with this aim. Recently a new product containing chlorhexidine, dexpanthenol, allantoin and chitosan (Bexident Post [BP]) in a gel formulation has been developed. We evaluated the efficacy of BP in controlling postsurgical inflammation and pain and in promoting cicatrization in subjects undergoing molar extractions. We conducted a prospective sequential cross-over, randomized controlled study in patients undergoing surgical removal of at least two impacted mandibular third molars (teeth numbers 38 and 48) (numbers 17 and 32 in the Universal Tooth Numbering System), in two separate sessions, to determine the effect of BP in comparison with bicarbonate (BC) oral rinse (one spoonful in 200 ml of water), both used three times daily. Each subject utilized both products in a randomized sequential manner after each tooth extraction. Primary outcomes of the study were post-procedure pain and inflammation. Secondary outcomes were analgesic pill rescue use (metamizole 1 cap every 8 hours if needed) and an assessor-blinded evaluation of cicatrization with a semi-quantitative scale (good, satisfactory and insufficient). Post-procedure pain was assessed 6 hours after tooth extraction and for seven consecutive days by means of a 10 cm visual analogue scale (VAS) (from 0: no pain to 10: extreme pain). The extent of inflammation was evaluated through metric measurements of facial perimeter using standardized anatomical reference points. A total of 47 patients (22 men and 25 women; mean age 34 years) were enrolled with a total of 94 molars extracted. Nineteen subjects applied BC as the first sequential treatment and 28 BP as the first. Before surgery no mean differences in the two treatments in inflammation measurements were observed. After surgery mean VAS pain score was similar between the two treatments in the first 6 hours (VAS score = 6.5). A marked progressive reduction in pain intensity with the use of BP was observed throughout the treatment period in comparison with BC (7 day mean scores 3.7 vs. 5.3; p = 0.0001). BP was superior to BC in reducing inflammation with -50% of the inflammation-related measurement (6 mm vs. 12 mm; p = 0.0001). Analgesic pill consumption was lower with BP in comparison with BC (13 pills vs. 24; p < 0.05). Cicatrization was scored 'good' in a higher percentage of subjects during BP use (64%) in comparison with the BC group (13%) (p = 0.0001). No serious side effects were reported with either treatment regimen. In this trial BP performed better than BC in controlling pain and inflammation in subjects undergoing dental surgery, reducing the consumption of analgesics and favoring better cicatrization.

Identifying, Quantifying, Extracting and Enhancing Implicit Parallelism

ERIC Educational Resources Information Center

Agarwal, Mayank

2009-01-01

The shift of the microprocessor industry towards multicore architectures has placed a huge burden on the programmers by requiring explicit parallelization for performance. Implicit Parallelization is an alternative that could ease the burden on programmers by parallelizing applications "under the covers" while maintaining sequential semantics…

Experiences with digital processing of images at INPE

NASA Technical Reports Server (NTRS)

Mascarenhas, N. D. A. (Principal Investigator)

1984-01-01

Four different research experiments with digital image processing at INPE will be described: (1) edge detection by hypothesis testing; (2) image interpolation by finite impulse response filters; (3) spatial feature extraction methods in multispectral classification; and (4) translational image registration by sequential tests of hypotheses.

Particle size and chemical control of heavy metals in bed sediment from the Rouge River, southeast Michigan

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

Murray, K.S.; Cauvet, D.; Lybeer, M.

1999-04-01

Anthropogenic activities related to 100 years of industrialization in the metropolitan Detroit area have significantly enriched the bed sediment of the lower reaches of the Rouge River in Cr, Cu, Fe, Ni, Pb, and Zn. These enriched elements, which may represent a threat to biota, are predominantly present in sequentially extracted reducible and oxidizable chemical phases with small contributions from residual phases. In size-fractionated samples trace metal concentrations generally increase with decreasing particle size, with the greatest contribution to this increase from the oxidizable phase. Experimental results obtained on replicate samples of river sediment demonstrate that the accuracy of themore » sequential extraction procedure, evaluated by comparing the sums of the three individual fractions, is generally better than 10%. Oxidizable and reducible phases therefore constitute important sources of potentially available heavy metals that need to be explicitly considered when evaluating sediment and water quality impacts on biota.« less

Heavy metal accumulation in surface sediments at the port of Cagliari (Sardinia, western Mediterranean): Environmental assessment using sequential extractions and benthic foraminifera.

PubMed

Schintu, Marco; Marrucci, Alessandro; Marras, Barbara; Galgani, Francois; Buosi, Carla; Ibba, Angelo; Cherchi, Antonietta

2016-10-15

Superficial sediments were taken at the port of Cagliari (Sardinia, Italy), which includes the oil terminal of one of the largest oil refineries in the Mediterranean. Significant trace metal concentrations were found in the whole port area. Sequential extraction of metals from the different sediment fractions (BCR method) showed a higher risk of remobilisation for Cd, which is mostly bound to the exchangeable fraction. Foraminiferal density and richness of species were variable across the study area. The living assemblages were characterized by low diversity in samples collected close to the port areas. Ammonia tepida and bolivinids, which were positively correlated with concentrations of heavy metals and organic matter content, appeared to show tolerance to the environmental disturbance. The sampling sites characterized by the highest values of biotic indices were located far from the port areas and present an epiphytic and epifaunal biocoenosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluating the Mobility of Arsenic in Synthetic Iron-containing Solids Using a Modified Sequential Extraction Method.

PubMed

Shan, Jilei; Sáez, A Eduardo; Ela, Wendell P

2010-02-01

Many water treatment technologies for arsenic removal that are used today produce arsenic-bearing residuals which are disposed in non-hazardous landfills. Previous works have established that many of these residuals will release arsenic to a much greater extent than predicted by standard regulatory leaching tests (e.g. the toxicity characteristic leaching procedure, TCLP) and, consequently, require stabilization to ensure benign behavior after disposal. In this work, a four-step sequential extraction method was developed in an effort to determine the proportion of arsenic in various phases in untreated as well as stabilized iron-based solid matrices. The solids synthesized using various potential stabilization techniques included: amorphous arsenic-iron sludge (ASL), reduced ASL via reaction with zero valent iron (RASL), amorphous ferrous arsenate (PFA), a mixture of PFA and SL (M1), crystalline ferrous arsenate (HPFA), and a mixture of HPFA and SL (M2). The overall arsenic mobility of the tested samples increased in the following order: ASL > RASL > PFA > M1 > HPFA > M2.

Sequential low and medium frequency ultrasound assists biodegradation of wheat chaff by white rot fungal enzymes.

PubMed

Oliver, Christine M; Mawson, Raymond; Melton, Laurence D; Dumsday, Geoff; Welch, Jessica; Sanguansri, Peerasak; Singh, Tanoj K; Augustin, Mary Ann

2014-10-13

The consequences of ultrasonic pre-treatment using low (40 kHz) and medium (270 kHz) frequency (40 kHz followed by 270 kHz) on the degradation of wheat chaff (8 g 100ml(-1) acetate buffer, pH 5) were evaluated. In addition, the effects of the ultrasonic pre-treatment on the degradation of the wheat chaff when subsequently exposed to enzyme extracts from two white rot fungi (Phanerochaete chrysosporium and Trametes sp.) were investigated. Pre-treatment by sequential low and medium frequency ultrasound had a disruptive effect on the lignocellulosic matrix. Analysis of the phenolic-derived volatiles after enzymatic hydrolysis showed that biodegradation with the enzyme extract obtained from P. chrysosporium was more pronounced compared to that of the Trametes sp. The efficacy of the ultrasonic pre-treatment was attributed to increased enzyme accessibility of the cellulose fibrils due to sonication-induced disruption of the plant surface structure, as shown by changes in the microstructure. Copyright © 2014 Elsevier Ltd. All rights reserved.

Droplet centrifugation, droplet DNA extraction, and rapid droplet thermocycling for simpler and faster PCR assay using wire-guided manipulations

PubMed Central

2012-01-01

A computer numerical control (CNC) apparatus was used to perform droplet centrifugation, droplet DNA extraction, and rapid droplet thermocycling on a single superhydrophobic surface and a multi-chambered PCB heater. Droplets were manipulated using “wire-guided” method (a pipette tip was used in this study). This methodology can be easily adapted to existing commercial robotic pipetting system, while demonstrated added capabilities such as vibrational mixing, high-speed centrifuging of droplets, simple DNA extraction utilizing the hydrophobicity difference between the tip and the superhydrophobic surface, and rapid thermocycling with a moving droplet, all with wire-guided droplet manipulations on a superhydrophobic surface and a multi-chambered PCB heater (i.e., not on a 96-well plate). Serial dilutions were demonstrated for diluting sample matrix. Centrifuging was demonstrated by rotating a 10 μL droplet at 2300 round per minute, concentrating E. coli by more than 3-fold within 3 min. DNA extraction was demonstrated from E. coli sample utilizing the disposable pipette tip to cleverly attract the extracted DNA from the droplet residing on a superhydrophobic surface, which took less than 10 min. Following extraction, the 1500 bp sequence of Peptidase D from E. coli was amplified using rapid droplet thermocycling, which took 10 min for 30 cycles. The total assay time was 23 min, including droplet centrifugation, droplet DNA extraction and rapid droplet thermocycling. Evaporation from of 10 μL droplets was not significant during these procedures, since the longest time exposure to air and the vibrations was less than 5 min (during DNA extraction). The results of these sequentially executed processes were analyzed using gel electrophoresis. Thus, this work demonstrates the adaptability of the system to replace many common laboratory tasks on a single platform (through re-programmability), in rapid succession (using droplets), and with a high level of accuracy and automation. PMID:22947281

Mechanical System Reliability and Cost Integration Using a Sequential Linear Approximation Method

NASA Technical Reports Server (NTRS)

Kowal, Michael T.

1997-01-01

The development of new products is dependent on product designs that incorporate high levels of reliability along with a design that meets predetermined levels of system cost. Additional constraints on the product include explicit and implicit performance requirements. Existing reliability and cost prediction methods result in no direct linkage between variables affecting these two dominant product attributes. A methodology to integrate reliability and cost estimates using a sequential linear approximation method is proposed. The sequential linear approximation method utilizes probability of failure sensitivities determined from probabilistic reliability methods as well a manufacturing cost sensitivities. The application of the sequential linear approximation method to a mechanical system is demonstrated.

Enzymatic treatment to improve extraction of capsaicinoids and carotenoids from chili (Capsicum annuum) fruits.

PubMed

Salgado-Roman, Manuel; Botello-Alvarez, Enrique; Rico-Martínez, Ramiro; Jiménez-Islas, Hugo; Cárdenas-Manríquez, Marcela; Navarrete-Bolaños, José Luis

2008-11-12

Enzymatic treatments using noncommercial enzymes as a means to the improve the extraction of carotenoids and capsaicinoids from chili fruits are explored in this study. The results show that it is possible to obtain chili fruit powder with a higher concentration of both capsaicinoids and carotenoids than previously reported for similar processes. Furthermore, extraction yields above 96% for carotenoids and 85% for capsaicinoids as separate fractions can be achieved using a sequential and selective two-stage extraction. Evidence is presented demonstrating that the content and extraction yield depend directly on the extent of the enzymatic hydrolysis of chili cell walls, and higher yields are obtained when the sample is completely hydrolyzed. The enzymatic treatment described here is a promising alternative to current industrial practices, and it improves the extraction of carotenoids and capsaicinoids from chili fruits.

Estimation of Cadmium uptake by tobacco plants from laboratory leaching tests.

PubMed

Marković, Jelena P; Jović, Mihajlo D; Smičiklas, Ivana D; Šljivić-Ivanović, Marija Z; Smiljanić, Slavko N; Onjia, Antonije E; Popović, Aleksandar R

2018-03-21

The objective of the present study was to determine the impact of cadmium (Cd) concentration in the soil on its uptake by tobacco plants, and to compare the ability of diverse extraction procedures for determining Cd bioavailability and predicting soil-to-plant transfer and Cd plant concentrations. The pseudo-total digestion procedure, modified Tessier sequential extraction and six standard single-extraction tests for estimation of metal mobility and bioavailability were used for the leaching of Cd from a native soil, as well as samples artificially contaminated over a wide range of Cd concentrations. The results of various leaching tests were compared between each other, as well as with the amounts of Cd taken up by tobacco plants in pot experiments. In the native soil sample, most of the Cd was found in fractions not readily available under natural conditions, but with increasing pollution level, Cd amounts in readily available forms increased. With increasing concentrations of Cd in the soil, the quantity of pollutant taken up in tobacco also increased, while the transfer factor (TF) decreased. Linear and non-linear empirical models were developed for predicting the uptake of Cd by tobacco plants based on the results of selected leaching tests. The non-linear equations for ISO 14870 (diethylenetriaminepentaacetic acid extraction - DTPA), ISO/TS 21268-2 (CaCl 2 leaching procedure), US EPA 1311 (toxicity characteristic leaching procedure - TCLP) single step extractions, and the sum of the first two fractions of the sequential extraction, exhibited the best correlation with the experimentally determined concentrations of Cd in plants over the entire range of pollutant concentrations. This approach can improve and facilitate the assessment of human exposure to Cd by tobacco smoking, but may also have wider applicability in predicting soil-to-plant transfer.

Selective dissolution followed by EDDS washing of an e-waste contaminated soil: Extraction efficiency, fate of residual metals, and impact on soil environment.

PubMed

Beiyuan, Jingzi; Tsang, Daniel C W; Valix, Marjorie; Zhang, Weihua; Yang, Xin; Ok, Yong Sik; Li, Xiang-Dong

2017-01-01

To enhance extraction of strongly bound metals from oxide minerals and organic matter, this study examined the sequential use of reductants, oxidants, alkaline solvents and organic acids followed by a biodegradable chelating agent (EDDS, [S,S]-ethylene-diamine-disuccinic-acid) in a two-stage soil washing. The soil was contaminated by Cu, Zn, and Pb at an e-waste recycling site in Qingyuan city, China. In addition to extraction efficiency, this study also examined the fate of residual metals (e.g., leachability, bioaccessibility, and distribution) and the soil quality parameters (i.e., cytotoxicity, enzyme activities, and available nutrients). The reductants (dithionite-citrate-bicarbonate and hydroxylamine hydrochloride) effectively extracted metals by mineral dissolution, but elevated the leachability and bioaccessibility of metals due to the transformation from Fe/Mn oxides to labile fractions. Subsequent EDDS washing was found necessary to mitigate the residual risks. In comparison, prior washing by oxidants (persulphate, hypochlorite, and hydrogen peroxide) was marginally useful because of limited amount of soil organic matter. Prior washing by alkaline solvents (sodium hydroxide and sodium bicarbonate) was also ineffective due to metal precipitation. In contrast, prior washing by low-molecular-weight organic acids (citrate and oxalate) improved the extraction efficiency. Compared to hydroxylamine hydrochloride, citrate and oxalate induced lower cytotoxicity (Microtox) and allowed higher enzyme activities (dehydrogenase, acid phosphatase, and urease) and soil nutrients (available nitrogen and phosphorus), which would facilitate reuse of the treated soil. Therefore, while sequential washing proved to enhance extraction efficacy, the selection of chemical agents besides EDDS should also include the consideration of effects on metal leachability/bioaccessibility and soil quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inhibitory effect of Terminalia chebula Retz. fruit extracts on digestive enzyme related to diabetes and oxidative stress.

PubMed

Sasidharan, Indu; Sundaresan, A; Nisha, V M; Kirishna, Mahesh S; Raghu, K G; Jayamurthy, P

2012-08-01

Terminalia chebula fruit extracts were prepared sequentially with hexane, ethyl acetate, methanol and methanol-water (70:30) and tested for their α-glucosidase inhibitory and antioxidant potential. The study resulted in the formulation of an extract with high α-glucosidase inhibitory potential (IC(50) 0.19 ± 0.03 µg mL(-1)) enriched with hydrolysable tannins. Also, each of the extract was chemically characterized by reversed-phase high-performance liquid chromatography on the basis of their marker compounds chebulagic acid, chebulinic acid and corilagin in order to give explanation to the significant activity shown by the extracts. The antioxidant potential of the highly active extract was evaluated in the cellular level also using superoxide dismutase, glutathione S-transferase and induced oxidative stress assays. The results indicated the possibility of using the extract as a nutraceutical health supplement in the management of type 2 diabetes.

Sequential weighted Wiener estimation for extraction of key tissue parameters in color imaging: a phantom study

NASA Astrophysics Data System (ADS)

Chen, Shuo; Lin, Xiaoqian; Zhu, Caigang; Liu, Quan

2014-12-01

Key tissue parameters, e.g., total hemoglobin concentration and tissue oxygenation, are important biomarkers in clinical diagnosis for various diseases. Although point measurement techniques based on diffuse reflectance spectroscopy can accurately recover these tissue parameters, they are not suitable for the examination of a large tissue region due to slow data acquisition. The previous imaging studies have shown that hemoglobin concentration and oxygenation can be estimated from color measurements with the assumption of known scattering properties, which is impractical in clinical applications. To overcome this limitation and speed-up image processing, we propose a method of sequential weighted Wiener estimation (WE) to quickly extract key tissue parameters, including total hemoglobin concentration (CtHb), hemoglobin oxygenation (StO2), scatterer density (α), and scattering power (β), from wide-band color measurements. This method takes advantage of the fact that each parameter is sensitive to the color measurements in a different way and attempts to maximize the contribution of those color measurements likely to generate correct results in WE. The method was evaluated on skin phantoms with varying CtHb, StO2, and scattering properties. The results demonstrate excellent agreement between the estimated tissue parameters and the corresponding reference values. Compared with traditional WE, the sequential weighted WE shows significant improvement in the estimation accuracy. This method could be used to monitor tissue parameters in an imaging setup in real time.

Evaluation of Pollutant Leaching Potential of Coal Ashes for Recycling

NASA Astrophysics Data System (ADS)

Park, D.; Woo, N. C.; Kim, H.; Yoon, H.; Chung, D.

2011-12-01

By 2009, coal ashes produced from coal-based power plants in Korea have been reused as cement supplement materials; however, the rest is mostly disposed in landfills inside the plant properties. Continuous production of coal ashes and limited landfill sites require more recycles of coal ashes as base materials, specifically in constructions of roads and of huge industrial complex. Previous researches showed that coal ashes could contain various metals such as arsenic(As), chromium(Cr), lead(Pb), nickel(Ni), selenium(Se), etc. In this study, we collected four types of bottom ashes and two of fly ashes from four coal-based power plants. These ash samples were tested with distilled water through the column leaching process in oxidized conditions. The column test results were compared with those of total digestion, sequential extraction processes and TCLP. Concentrations of metals in outflows from columns are generally greater in fly ashes than in bottom ashes, specifically for As, Se, B, Sr and SO4. Only one fly ash (J2-F) shows high concentrations of arsenic and selenium in leachate. Sequential extraction results indicate that these metals are in readily soluble forms, such as adsorbed, carbonated, and reducible forms. Results of TCLP analysis indicate no potential contaminants leached from the ashes. In conclusion, recycling of coal combustion ashes could be encouraged with proper tests such as sequential and leaching experiments.

Leaching behavior of rare earth elements in fort union lignite coals of North America

DOE PAGES

Laudal, Daniel A.; Benson, Steven A.; Addleman, Raymond Shane; ...

2018-03-30

Fort Union lignite coal samples were subjected to a series of aqueous leaching experiments to understand the extraction behavior of the rare earth elements (REE). This testing was aimed at understanding the modes of occurrence of the REE in the lignite coals, as well as to provide foundational data for development of rare earth extraction processes. In a first series of tests, a sequential leaching process was used to investigate modes of occurrence of the REE of select lignite coals. The tests involved sequential exposure to solvents consisting of water, ammonium acetate and dilute hydrochloric acid (HCl). The results indicatedmore » that water and ammonium acetate extracted very little of the REE, indicating the REE are not present as water soluble or ion-exchangeable forms. However, the data shows that a large percentage of the REE were extracted with the hydrochloric acid (80–95 wt%), suggesting presence in HCl-soluble mineral forms such as carbonates, and/or presence as organic complexes. A second series of tests was performed involving single-step leaching with dilute acids and various operating parameters, including acid type, acid concentration, acid/coal contact time and coal particle size. For select samples, additional tests were performed to understand the results of leaching, including float-sink density separations and humic acid extraction. The results have shown that the majority of REE in Fort Union lignites appear to be associated weakly with the organic matrix of the coals, most likely as coordination complexes of carboxylic acid groups. The light REE and heavy REE exhibit different behaviors, however. The extractable light REE appear to have association both in acid-soluble mineral forms and as organic complexes, whereas the extractable heavy REE appear to be almost solely associated with the organics. In conclusion, scandium behavior was notably different than yttrium and the lanthanides, and the data suggests the extractable content is primarily associated as acid-soluble mineral forms.« less

Leaching behavior of rare earth elements in fort union lignite coals of North America

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

Laudal, Daniel A.; Benson, Steven A.; Addleman, Raymond Shane

Fort Union lignite coal samples were subjected to a series of aqueous leaching experiments to understand the extraction behavior of the rare earth elements (REE). This testing was aimed at understanding the modes of occurrence of the REE in the lignite coals, as well as to provide foundational data for development of rare earth extraction processes. In a first series of tests, a sequential leaching process was used to investigate modes of occurrence of the REE of select lignite coals. The tests involved sequential exposure to solvents consisting of water, ammonium acetate and dilute hydrochloric acid (HCl). The results indicatedmore » that water and ammonium acetate extracted very little of the REE, indicating the REE are not present as water soluble or ion-exchangeable forms. However, the data shows that a large percentage of the REE were extracted with the hydrochloric acid (80–95 wt%), suggesting presence in HCl-soluble mineral forms such as carbonates, and/or presence as organic complexes. A second series of tests was performed involving single-step leaching with dilute acids and various operating parameters, including acid type, acid concentration, acid/coal contact time and coal particle size. For select samples, additional tests were performed to understand the results of leaching, including float-sink density separations and humic acid extraction. The results have shown that the majority of REE in Fort Union lignites appear to be associated weakly with the organic matrix of the coals, most likely as coordination complexes of carboxylic acid groups. The light REE and heavy REE exhibit different behaviors, however. The extractable light REE appear to have association both in acid-soluble mineral forms and as organic complexes, whereas the extractable heavy REE appear to be almost solely associated with the organics. In conclusion, scandium behavior was notably different than yttrium and the lanthanides, and the data suggests the extractable content is primarily associated as acid-soluble mineral forms.« less

Hypocholesterolemic property of Yucca schidigera and Quillaja saponaria extracts in human body.

PubMed

Kim, Sang-Woo; Park, Sang-Kyu; Kang, Sung-Il; Kang, Han-Chul; Oh, Han-Jin; Bae, Chul-Young; Bae, Dong-Ho

2003-12-01

This study was undertaken to observe the effects of the blend of partially purified Yucca schidigera and Quillaja saponaria extracts on cholesterol levels in the human's blood and gastrointestinal functions, and to determine if a new cholesterol-lowering drug can be developed by the further purification of the extracts. Ultrafiltration and sequential diafiltration increased the amounts of steroidal saponin in aqueous yucca extract and terpenoid saponin in aqueous quillaja extract from 9.3% and 21.4% to 17.2% and 61.8%, respectively. Taking 0.9 mg of the blend (6:4, v:v) of the resulting filtrates a day for 4 weeks resulted in the decreases in total and LDL cholesterol levels in blood plasma of hyper-cholesterolemic patients with enhancement in gastrointestinal symptoms of patients.

Kurtosis-Based Blind Source Extraction of Complex Non-Circular Signals with Application in EEG Artifact Removal in Real-Time

PubMed Central

Javidi, Soroush; Mandic, Danilo P.; Took, Clive Cheong; Cichocki, Andrzej

2011-01-01

A new class of complex domain blind source extraction algorithms suitable for the extraction of both circular and non-circular complex signals is proposed. This is achieved through sequential extraction based on the degree of kurtosis and in the presence of non-circular measurement noise. The existence and uniqueness analysis of the solution is followed by a study of fast converging variants of the algorithm. The performance is first assessed through simulations on well understood benchmark signals, followed by a case study on real-time artifact removal from EEG signals, verified using both qualitative and quantitative metrics. The results illustrate the power of the proposed approach in real-time blind extraction of general complex-valued sources. PMID:22319461

Sequential healing of open extraction sockets. An experimental study in monkeys.

PubMed

Scala, Alessandro; Lang, Niklaus P; Schweikert, Michael T; de Oliveira, José Américo; Rangel-Garcia, Idelmo; Botticelli, Daniele

2014-03-01

To describe the sequential healing of open extraction sockets at which no attempts to obtain a primary closure of the coronal access to the alveolus have been made. The third mandibular premolar was extracted bilaterally in 12 monkeys, and no sutures were applied to close the wound. The healing after 4, 10, 20, 30, 90 and 180 days was morphometrically studied. After 4 days of healing, a blood clot mainly occupied the extraction sockets, with the presence of an inflammatory cells' infiltrate. A void was confined in the central zones of the coronal and middle regions, in continuity with the entrance of the alveoli. At 10 days, the alveolus was occupied by a provisional matrix, with new bone formation lining the socket bony walls. At 20 days, the amount of woven bone was sensibly increasing. At 30 days, the alveolar socket was mainly occupied by mineralized immature bone at different stages of healing. At 90 and 180 days, the amount of mineralized bone decreased and substituted by trabecular bone and bone marrow. Bundle bone decreased from 95.5% at 4 days to 7.6% at 180 days, of the whole length of the inner alveolar surface. Modeling processes start from the lateral and apical walls of the alveolus, leading to the closure of the socket with newly formed bone within a month from extraction. Remodeling processes will follow the previous stages, resulting in trabecular and bone marrow formation and in a corticalization of the socket access. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

Real-time sensing of lint quality

USDA-ARS?s Scientific Manuscript database

Modem cotton gins have the purpose of extracting lint (the cotton) from trash and seeds- usually the sticks, leaves and burrs that are entrained with the cotton. These modem gins include many individual machine components that are operated sequentially to form the gin processing line. Recent on-line...

Pitch Fractionation.

DTIC Science & Technology

1981-12-15

The solvent fractions were obtained by sequential Soxhlet extraction with solvents such as hexane, cyclohexane, toluene, and pyridine. The most severe...Continued) *.AISYRACT (Continued) fraction increased, the pyrolysis yield and bloating increased, and the msicrostructure of the coke became finer...28 8. Coking Yield and Bloating Behavior of Fractionation Sequence AG 162-4

Intrinsic fluorescence excitation-emission matrix spectral features of cottonseed protein fractions and the effects of denaturants

USDA-ARS?s Scientific Manuscript database

To better understand the functional and physicochemical properties of cottonseed protein, we investigated the intrinsic fluorescence excitation-emission matrix (EEM) spectral features of cottonseed protein isolate (CSPI) and sequentially extracted water (CSPw) and alkali (CSPa) protein fractions, an...

ASSESSING SPECIATION AND RELEASE OF HEAVY METALS FROM COAL COMBUSTION PRODUCTS

EPA Science Inventory

In this study, the speciation of heavy metals such as arsenic, selenium, lead, zinc and mercury in coal combustion products (CCPs) was evaluated using sequential extraction procedures. Coal fly ash, bottom ash and flue gas desulphurization (FGD) sludge samples were used in the ex...

Sequential air sampler system : its use by the Virginia Department of Highways & Transportation.

DOT National Transportation Integrated Search

1975-01-01

The Department of Highways & Transportation needs an economical and efficient air quality sampling system for meeting requirements on air monitoring for proposed projects located In critical areas. Two sequential air sampling systems, the ERAI and th...

Biological Activities of Asteraceae (Achillea millefolium and Calendula officinalis) and Lamiaceae (Melissa officinalis and Origanum majorana) Plant Extracts.

PubMed

García-Risco, Mónica R; Mouhid, Lamia; Salas-Pérez, Lilia; López-Padilla, Alexis; Santoyo, Susana; Jaime, Laura; Ramírez de Molina, Ana; Reglero, Guillermo; Fornari, Tiziana

2017-03-01

Asteraceae (Achillea millefolium and Calendula officinalis) and Lamiaceae (Melissa officinalis and Origanum majorana) extracts were obtained by applying two sequential extraction processes: supercritical fluid extraction with carbon dioxide, followed by ultrasonic assisted extraction using green solvents (ethanol and ethanol:water 50:50). The extracts were analyzed in terms of the total content of phenolic compounds and the content of flavonoids; the volatile oil composition of supercritical extracts was analyzed by gas chromatography and the antioxidant capacity and cell toxicity was determined. Lamiaceae plant extracts presented higher content of phenolics (and flavonoids) than Asteraceae extracts. Regardless of the species studied, the supercritical extracts presented the lowest antioxidant activity and the ethanol:water extracts offered the largest, following the order Origanum majorana > Melissa officinalis ≈ Achillea millefolium > Calendula officinalis. However, concerning the effect on cell toxicity, Asteraceae (especially Achillea millefolium) supercritical extracts were significantly more efficient despite being the less active as an antioxidant agent. These results indicate that the effect on cell viability is not related to the antioxidant activity of the extracts.

Database assessment of CMIP5 and hydrological models to determine flood risk areas

NASA Astrophysics Data System (ADS)

Limlahapun, Ponthip; Fukui, Hiromichi

2016-11-01

Solutions for water-related disasters may not be solved with a single scientific method. Based on this premise, we involved logic conceptions, associate sequential result amongst models, and database applications attempting to analyse historical and future scenarios in the context of flooding. The three main models used in this study are (1) the fifth phase of the Coupled Model Intercomparison Project (CMIP5) to derive precipitation; (2) the Integrated Flood Analysis System (IFAS) to extract amount of discharge; and (3) the Hydrologic Engineering Center (HEC) model to generate inundated areas. This research notably focused on integrating data regardless of system-design complexity, and database approaches are significantly flexible, manageable, and well-supported for system data transfer, which makes them suitable for monitoring a flood. The outcome of flood map together with real-time stream data can help local communities identify areas at-risk of flooding in advance.

Face Liveness Detection Using Defocus

PubMed Central

Kim, Sooyeon; Ban, Yuseok; Lee, Sangyoun

2015-01-01

In order to develop security systems for identity authentication, face recognition (FR) technology has been applied. One of the main problems of applying FR technology is that the systems are especially vulnerable to attacks with spoofing faces (e.g., 2D pictures). To defend from these attacks and to enhance the reliability of FR systems, many anti-spoofing approaches have been recently developed. In this paper, we propose a method for face liveness detection using the effect of defocus. From two images sequentially taken at different focuses, three features, focus, power histogram and gradient location and orientation histogram (GLOH), are extracted. Afterwards, we detect forged faces through the feature-level fusion approach. For reliable performance verification, we develop two databases with a handheld digital camera and a webcam. The proposed method achieves a 3.29% half total error rate (HTER) at a given depth of field (DoF) and can be extended to camera-equipped devices, like smartphones. PMID:25594594

High-resolution extraction of particle size via Fourier Ptychography

NASA Astrophysics Data System (ADS)

Li, Shengfu; Zhao, Yu; Chen, Guanghua; Luo, Zhenxiong; Ye, Yan

2017-11-01

This paper proposes a method which can extract the particle size information with a resolution beyond λ/NA. This is achieved by applying Fourier Ptychographic (FP) ideas to the present problem. In a typical FP imaging platform, a 2D LED array is used as light sources for angle-varied illuminations, a series of low-resolution images was taken by a full sequential scan of the array of LEDs. Here, we demonstrate the particle size information is extracted by turning on each single LED on a circle. The simulated results show that the proposed method can reduce the total number of images, without loss of reliability in the results.

Experiences of detained young offenders in need of mental health care.

PubMed

Shelton, Deborah

2004-01-01

To explore the experiences of young people detained in the juvenile justice system and in need of mental health services. An ethnomethodological analysis was done using Kleinman's Explanatory Model Interview Guide to explore the perceptions of detained young people in need of mental health treatment. Five themes were extracted from focus groups, indicating lack of control in their lives and lack of family and community support. Although participants expressed feelings of hopelessness and depression, they perceived that it was better to be tough than to be sick. The findings indicate the need for multimodal treatment interventions to sequentially address the multiple internal and external factors contributing to persistent problem behaviors in children.

Computer-Based Instruction for TRIDENT FBM Training

DTIC Science & Technology

1976-06-01

remote voice feedback to an operator. In this case it is possible to display text which represents the voice messages required during sequential ...provides two main services: (a) the preparation of missiles for sequential launching with self-guidance after launch, and (b) the coordination of...monitor- ing the status of the guidance system in each missile. FCS SWS coordina- tion consists of monitoring systems involved in sequential functions at

[Relation between distribution of phosphorus form in the sediment of typical urban shallow lakes and eutrophication].

PubMed

Wang, Chao; Zou, Li-Min; Wang, Pei-Fang; Lin, Zhi-Ping

2008-05-01

The forms of phosphorus in the surface sediments were extracted and determined sequentially with ethylene dinitrilo tetracetic acid (EDTA) technique in three urban shallow lakes: Lake Xuanwu, Lake Mochou and Lake Daming. The results showed that the iron and calcium-bound phosphate, about accounting for 80%, were the main forms of total phosphorus. The contents of iron bound phosphate in Lake Xuanwu and Lake Mochou were higher than that of Lake Daming, reaching 30%-40%. The organic phosphorus existed mainly in the form of alkali extractable phosphorus, while the contents of acid extractable organic phosphorus were low. However, the proportion of acid extractable organic phosphorus to the total phosphorus can indicate the degree of lake eutrophication.

Comparison of three sequential extraction procedures for arsenic fractionation in highly polluted sites.

PubMed

Wan, Xiang; Dong, Haochen; Feng, Liu; Lin, Zhijia; Luo, Qiuchen

2017-07-01

Three sequential extraction procedures (SEPs) including Tessier, Rauret, and Shiowatana SEPs, were compared for arsenic fractionation using highly polluted soils. In the definition context of exchangeable, reducible, oxidizable and residual fractions, with similar arsenic recovery and reproducibility, Tessier and Rauret SEPs were comparable to each other, whereas Shiowatana SEP showed higher extraction efficiency in all the first three arsenic fractions, although it might overestimate the reducible arsenic. Pot experiment indicated three SEPs all could provide an estimation of the most bioavailable arsenic fraction, and the application of Shiowatana SEP should be preferred. Accordingly, a case study with Shiowatana SEP for a site near a realgar mine area is conducted. The results show that although arsenic in this area presents predominantly in the stable fractions, the sum of most bioavailable fractions was accounted around 11% of total arsenic, and moreover, about another 10% of the total arsenic, the fourth fraction in Shiowatana SEP is likely to be transferred into bioavailable species under suitable conditions, such as strong acid impact, revealing a real major risk source being formed. The study indicated that Shiowatana should be more suitable for arsenic fractionation to provide valuable information in the framework of risk assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

SHORT-TERM SOLAR FLARE PREDICTION USING MULTIRESOLUTION PREDICTORS

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

Yu Daren; Huang Xin; Hu Qinghua

2010-01-20

Multiresolution predictors of solar flares are constructed by a wavelet transform and sequential feature extraction method. Three predictors-the maximum horizontal gradient, the length of neutral line, and the number of singular points-are extracted from Solar and Heliospheric Observatory/Michelson Doppler Imager longitudinal magnetograms. A maximal overlap discrete wavelet transform is used to decompose the sequence of predictors into four frequency bands. In each band, four sequential features-the maximum, the mean, the standard deviation, and the root mean square-are extracted. The multiresolution predictors in the low-frequency band reflect trends in the evolution of newly emerging fluxes. The multiresolution predictors in the high-frequencymore » band reflect the changing rates in emerging flux regions. The variation of emerging fluxes is decoupled by wavelet transform in different frequency bands. The information amount of these multiresolution predictors is evaluated by the information gain ratio. It is found that the multiresolution predictors in the lowest and highest frequency bands contain the most information. Based on these predictors, a C4.5 decision tree algorithm is used to build the short-term solar flare prediction model. It is found that the performance of the short-term solar flare prediction model based on the multiresolution predictors is greatly improved.« less

Four factors underlying mouse behavior in an open field

PubMed Central

Tanaka, Shoji; Young, Jared W.; Halberstadt, Adam L.; Masten, Virginia L.; Geyer, Mark A.

2012-01-01

The observation of the locomotor and exploratory behaviors of rodents in an open field is one of the most fundamental methods used in the field of behavioral pharmacology. A variety of behaviors can be recorded automatically and can readily generate a multivariate pattern of pharmacological effects. Nevertheless, the optimal ways to characterize observed behaviors and concomitant drug effects are still under development. The aim of this study was to extract meaningful behavioral factors that could explain variations in the observed variables from mouse exploration. Behavioral data were recorded from male C57BL/6J mice (n = 268) using the Behavioral Pattern Monitor (BPM). The BPM data were subjected to the exploratory factor analysis. The factor analysis extracted four factors: activity, sequential organization, diversive exploration, and inspective exploration. The activity factor and the two types of exploration factors correlated positively with one another, while the sequential organization factor negatively correlated with the remaining factors. The extracted factor structure constitutes a behavioral model of mouse exploration. This model will provide a platform on which one can assess the effects of psychoactive drugs and genetic manipulations on mouse exploratory behavior. Further studies are currently underway to examine the factor structure of similar multivariate data sets from humans tested in a human BPM. PMID:22569582

Four factors underlying mouse behavior in an open field.

PubMed

Tanaka, Shoji; Young, Jared W; Halberstadt, Adam L; Masten, Virginia L; Geyer, Mark A

2012-07-15

The observation of the locomotor and exploratory behaviors of rodents in an open field is one of the most fundamental methods used in the field of behavioral pharmacology. A variety of behaviors can be recorded automatically and can readily generate a multivariate pattern of pharmacological effects. Nevertheless, the optimal ways to characterize observed behaviors and concomitant drug effects are still under development. The aim of this study was to extract meaningful behavioral factors that could explain variations in the observed variables from mouse exploration. Behavioral data were recorded from male C57BL/6J mice (n=268) using the Behavioral Pattern Monitor (BPM). The BPM data were subjected to the exploratory factor analysis. The factor analysis extracted four factors: activity, sequential organization, diversive exploration, and inspective exploration. The activity factor and the two types of exploration factors correlated positively with one another, while the sequential organization factor negatively correlated with the remaining factors. The extracted factor structure constitutes a behavioral model of mouse exploration. This model will provide a platform on which one can assess the effects of psychoactive drugs and genetic manipulations on mouse exploratory behavior. Further studies are currently underway to examine the factor structure of similar multivariate data sets from humans tested in a human BPM. Copyright © 2012 Elsevier B.V. All rights reserved.

The Potential of Sequential Extraction in the Characterisation and Management of Wastes from Steel Processing: A Prospective Review

PubMed Central

Rodgers, Kiri J.; Hursthouse, Andrew; Cuthbert, Simon

2015-01-01

As waste management regulations become more stringent, yet demand for resources continues to increase, there is a pressing need for innovative management techniques and more sophisticated supporting analysis techniques. Sequential extraction (SE) analysis, a technique previously applied to soils and sediments, offers the potential to gain a better understanding of the composition of solid wastes. SE attempts to classify potentially toxic elements (PTEs) by their associations with phases or fractions in waste, with the aim of improving resource use and reducing negative environmental impacts. In this review we explain how SE can be applied to steel wastes. These present challenges due to differences in sample characteristics compared with materials to which SE has been traditionally applied, specifically chemical composition, particle size and pH buffering capacity, which are critical when identifying a suitable SE method. We highlight the importance of delineating iron-rich phases, and find that the commonly applied BCR (The community Bureau of reference) extraction method is problematic due to difficulties with zinc speciation (a critical steel waste constituent), hence a substantially modified SEP is necessary to deal with particular characteristics of steel wastes. Successful development of SE for steel wastes could have wider implications, e.g., for the sustainable management of fly ash and mining wastes. PMID:26393631

The Potential of Sequential Extraction in the Characterisation and Management of Wastes from Steel Processing: A Prospective Review.

PubMed

Rodgers, Kiri J; Hursthouse, Andrew; Cuthbert, Simon

2015-09-18

As waste management regulations become more stringent, yet demand for resources continues to increase, there is a pressing need for innovative management techniques and more sophisticated supporting analysis techniques. Sequential extraction (SE) analysis, a technique previously applied to soils and sediments, offers the potential to gain a better understanding of the composition of solid wastes. SE attempts to classify potentially toxic elements (PTEs) by their associations with phases or fractions in waste, with the aim of improving resource use and reducing negative environmental impacts. In this review we explain how SE can be applied to steel wastes. These present challenges due to differences in sample characteristics compared with materials to which SE has been traditionally applied, specifically chemical composition, particle size and pH buffering capacity, which are critical when identifying a suitable SE method. We highlight the importance of delineating iron-rich phases, and find that the commonly applied BCR (The community Bureau of reference) extraction method is problematic due to difficulties with zinc speciation (a critical steel waste constituent), hence a substantially modified SEP is necessary to deal with particular characteristics of steel wastes. Successful development of SE for steel wastes could have wider implications, e.g., for the sustainable management of fly ash and mining wastes.

Potential Transport and Degradation of “Aged” Pesticide Residues in Soil

USDA-ARS?s Scientific Manuscript database

Increased pesticide residence time in soil, or “aging”, has been shown to affect the sorption-desorption of pesticides in the soil, which in turn can control transport and degradation processes. Aging effects have been characterized by batch sequential extraction methods, in which sorption coefficie...

Potential transport and degradation of “Aged” pesticide residues in soil

USDA-ARS?s Scientific Manuscript database

“Aging” has been shown to affect the sorption-desorption of pesticides in the soil, which in turn can control transport and degradation processes. Aging effects have been characterized by batch sequential extraction methods, in which sorption coefficients (i.e. Kd) are determined for the chemical re...

AN IN VITRO GASTROINTESTINAL METHOD TO ESTIMATE BIOAVAILABLE ARSENIC IN CONTAMINATED SOILS AND SOLID MEDIA. (R825410)

EPA Science Inventory

A method was developed to simulate the human gastrointestinal environment and
to estimate bioavailability of arsenic in contaminated soil and solid media. In
this in vitro gastrointestinal (IVG) method, arsenic is sequentially extracted
from contaminated soil with ...

A Human Activity Recognition System Based on Dynamic Clustering of Skeleton Data.

PubMed

Manzi, Alessandro; Dario, Paolo; Cavallo, Filippo

2017-05-11

Human activity recognition is an important area in computer vision, with its wide range of applications including ambient assisted living. In this paper, an activity recognition system based on skeleton data extracted from a depth camera is presented. The system makes use of machine learning techniques to classify the actions that are described with a set of a few basic postures. The training phase creates several models related to the number of clustered postures by means of a multiclass Support Vector Machine (SVM), trained with Sequential Minimal Optimization (SMO). The classification phase adopts the X-means algorithm to find the optimal number of clusters dynamically. The contribution of the paper is twofold. The first aim is to perform activity recognition employing features based on a small number of informative postures, extracted independently from each activity instance; secondly, it aims to assess the minimum number of frames needed for an adequate classification. The system is evaluated on two publicly available datasets, the Cornell Activity Dataset (CAD-60) and the Telecommunication Systems Team (TST) Fall detection dataset. The number of clusters needed to model each instance ranges from two to four elements. The proposed approach reaches excellent performances using only about 4 s of input data (~100 frames) and outperforms the state of the art when it uses approximately 500 frames on the CAD-60 dataset. The results are promising for the test in real context.

Bayesian inversion analysis of nonlinear dynamics in surface heterogeneous reactions.

PubMed

Omori, Toshiaki; Kuwatani, Tatsu; Okamoto, Atsushi; Hukushima, Koji

2016-09-01

It is essential to extract nonlinear dynamics from time-series data as an inverse problem in natural sciences. We propose a Bayesian statistical framework for extracting nonlinear dynamics of surface heterogeneous reactions from sparse and noisy observable data. Surface heterogeneous reactions are chemical reactions with conjugation of multiple phases, and they have the intrinsic nonlinearity of their dynamics caused by the effect of surface-area between different phases. We adapt a belief propagation method and an expectation-maximization (EM) algorithm to partial observation problem, in order to simultaneously estimate the time course of hidden variables and the kinetic parameters underlying dynamics. The proposed belief propagation method is performed by using sequential Monte Carlo algorithm in order to estimate nonlinear dynamical system. Using our proposed method, we show that the rate constants of dissolution and precipitation reactions, which are typical examples of surface heterogeneous reactions, as well as the temporal changes of solid reactants and products, were successfully estimated only from the observable temporal changes in the concentration of the dissolved intermediate product.

Improving enzymatic hydrolysis efficiency of wheat straw through sequential autohydrolysis and alkaline post-extraction.

PubMed

Wu, Xinxing; Huang, Chen; Zhai, Shengcheng; Liang, Chen; Huang, Caoxing; Lai, Chenhuan; Yong, Qiang

2018-03-01

In this work, a two-step pretreatment process of wheat straw was established by combining autohydrolysis pretreatment and alkaline post-extraction. The results showed that employing alkaline post-extraction to autohydrolyzed wheat straw could significantly improve its enzymatic hydrolysis efficiency from 36.0% to 83.7%. Alkaline post-extraction lead to the changes of the structure characteristics of autohydrolyzed wheat straw. Associations between enzymatic hydrolysis efficiency and structure characteristics were also studied. The results showed that the factors of structure characteristics such as delignification, xylan removal yield, crystallinity, accessibility and hydrophobicity are positively related to enzymatic hydrolysis efficiency within a certain range for alkaline post-extracted wheat straw. The results demonstrated that autohydrolysis coupled with alkaline post-extraction is an effective and promising method to gain fermentable sugars from biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimization, formulation, and characterization of multiflavonoids-loaded flavanosome by bulk or sequential technique

PubMed Central

Karthivashan, Govindarajan; Masarudin, Mas Jaffri; Kura, Aminu Umar; Abas, Faridah; Fakurazi, Sharida

2016-01-01

This study involves adaptation of bulk or sequential technique to load multiple flavonoids in a single phytosome, which can be termed as “flavonosome”. Three widely established and therapeutically valuable flavonoids, such as quercetin (Q), kaempferol (K), and apigenin (A), were quantified in the ethyl acetate fraction of Moringa oleifera leaves extract and were commercially obtained and incorporated in a single flavonosome (QKA–phosphatidylcholine) through four different methods of synthesis – bulk (M1) and serialized (M2) co-sonication and bulk (M3) and sequential (M4) co-loading. The study also established an optimal formulation method based on screening the synthesized flavonosomes with respect to their size, charge, polydispersity index, morphology, drug–carrier interaction, antioxidant potential through in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics, and cytotoxicity evaluation against human hepatoma cell line (HepaRG). Furthermore, entrapment and loading efficiency of flavonoids in the optimal flavonosome have been identified. Among the four synthesis methods, sequential loading technique has been optimized as the best method for the synthesis of QKA–phosphatidylcholine flavonosome, which revealed an average diameter of 375.93±33.61 nm, with a zeta potential of −39.07±3.55 mV, and the entrapment efficiency was >98% for all the flavonoids, whereas the drug-loading capacity of Q, K, and A was 31.63%±0.17%, 34.51%±2.07%, and 31.79%±0.01%, respectively. The in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics of the flavonoids indirectly depicts the release kinetic behavior of the flavonoids from the carrier. The QKA-loaded flavonosome had no indication of toxicity toward human hepatoma cell line as shown by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide result, wherein even at the higher concentration of 200 µg/mL, the flavonosomes exert >85% of cell viability. These results suggest that sequential loading technique may be a promising nanodrug delivery system for loading multiflavonoids in a single entity with sustained activity as an antioxidant, hepatoprotective, and hepatosupplement candidate. PMID:27555765

Optimization, formulation, and characterization of multiflavonoids-loaded flavanosome by bulk or sequential technique.

PubMed

Karthivashan, Govindarajan; Masarudin, Mas Jaffri; Kura, Aminu Umar; Abas, Faridah; Fakurazi, Sharida

2016-01-01

This study involves adaptation of bulk or sequential technique to load multiple flavonoids in a single phytosome, which can be termed as "flavonosome". Three widely established and therapeutically valuable flavonoids, such as quercetin (Q), kaempferol (K), and apigenin (A), were quantified in the ethyl acetate fraction of Moringa oleifera leaves extract and were commercially obtained and incorporated in a single flavonosome (QKA-phosphatidylcholine) through four different methods of synthesis - bulk (M1) and serialized (M2) co-sonication and bulk (M3) and sequential (M4) co-loading. The study also established an optimal formulation method based on screening the synthesized flavonosomes with respect to their size, charge, polydispersity index, morphology, drug-carrier interaction, antioxidant potential through in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics, and cytotoxicity evaluation against human hepatoma cell line (HepaRG). Furthermore, entrapment and loading efficiency of flavonoids in the optimal flavonosome have been identified. Among the four synthesis methods, sequential loading technique has been optimized as the best method for the synthesis of QKA-phosphatidylcholine flavonosome, which revealed an average diameter of 375.93±33.61 nm, with a zeta potential of -39.07±3.55 mV, and the entrapment efficiency was >98% for all the flavonoids, whereas the drug-loading capacity of Q, K, and A was 31.63%±0.17%, 34.51%±2.07%, and 31.79%±0.01%, respectively. The in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics of the flavonoids indirectly depicts the release kinetic behavior of the flavonoids from the carrier. The QKA-loaded flavonosome had no indication of toxicity toward human hepatoma cell line as shown by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide result, wherein even at the higher concentration of 200 µg/mL, the flavonosomes exert >85% of cell viability. These results suggest that sequential loading technique may be a promising nanodrug delivery system for loading multiflavonoids in a single entity with sustained activity as an antioxidant, hepatoprotective, and hepatosupplement candidate.

Retention and chemical speciation of uranium in an oxidized wetland sediment from the Savannah River Site.

PubMed

Li, Dien; Seaman, John C; Chang, Hyun-Shik; Jaffe, Peter R; Koster van Groos, Paul; Jiang, De-Tong; Chen, Ning; Lin, Jinru; Arthur, Zachary; Pan, Yuanming; Scheckel, Kirk G; Newville, Matthew; Lanzirotti, Antonio; Kaplan, Daniel I

2014-05-01

Uranium speciation and retention mechanisms onto Savannah River Site (SRS) wetland sediments was studied using batch (ad)sorption experiments, sequential extraction, U L3-edge X-ray absorption near-edge structure (XANES) spectroscopy, fluorescence mapping and μ-XANES. Under oxidized conditions, U was highly retained by the SRS wetland sediments. In contrast to other similar but much lower natural organic matter (NOM) sediments, significant sorption of U onto the SRS sediments was observed at pH < 4 and pH > 8. Sequential extraction indicated that the U species were primarily associated with the acid soluble fraction (weak acetic acid extractable) and organic fraction (Na-pyrophosphate extractable). Uranium L3-edge XANES spectra of the U-bound sediments were nearly identical to that of uranyl acetate. Based on fluorescence mapping, U and Fe distributions in the sediment were poorly correlated, U was distributed throughout the sample and did not appear as isolated U mineral phases. The primary oxidation state of U in these oxidized sediments was U(VI), and there was little evidence that the high sorptive capacity of the sediments could be ascribed to abiotic or biotic reduction to the less soluble U(IV) species or to secondary mineral formation. Collectively, this study suggests that U may be strongly bound to wetland sediments, not only under reducing conditions by reductive precipitation, but also under oxidizing conditions through NOM-uranium bonding. Published by Elsevier Ltd.

Assessing of distribution, mobility and bioavailability of exogenous Pb in agricultural soils using isotopic labeling method coupled with BCR approach.

PubMed

Huang, Zhi-Yong; Xie, Hong; Cao, Ying-Lan; Cai, Chao; Zhang, Zhi

2014-02-15

The contamination of Pb in agricultural soils is one of the most important ecological problems, which potentially results in serious health risk on human health through food chain. Hence, the fate of exogenous Pb contaminated in agricultural soils is needed to be deeply explored. By spiking soils with the stable enriched isotopes of (206)Pb, the contamination of exogenous Pb(2+) ions in three agricultural soils sampled from the estuary areas of Jiulong River, China was simulated in the present study, and the distribution, mobility and bioavailability of exogenous Pb in the soils were investigated using the isotopic labeling method coupled with a four-stage BCR (European Community Bureau of Reference) sequential extraction procedure. Results showed that about 60-85% of exogenous Pb was found to distribute in reducible fractions, while the exogenous Pb in acid-extractable fractions was less than 1.0%. After planting, the amounts of exogenous Pb presenting in acid-extractable, reducible and oxidizable fractions in rhizospheric soils decreased by 60-66%, in which partial exogenous Pb was assimilated by plants while most of the metal might transfer downward due to daily watering and applying fertilizer. The results show that the isotopic labeling technique coupled with sequential extraction procedures enables us to explore the distribution, mobility and bioavailability of exogenous Pb contaminated in soils, which may be useful for the further soil remediation. Copyright © 2014 Elsevier B.V. All rights reserved.

Methodological Considerations for Hair Cortisol Measurements in Children

PubMed Central

Slominski, Radomir; Rovnaghi, Cynthia R.; Anand, Kanwaljeet J. S.

2015-01-01

Background Hair cortisol levels are used increasingly as a measure for chronic stress in young children. We propose modifications to the current methods used for hair cortisol analysis to more accurately determine reference ranges for hair cortisol across different populations and age groups. Methods The authors compared standard (finely cutting hair) vs. milled methods for hair processing (n=16), developed a 4-step extraction process for hair protein and cortisol (n=16), and compared liquid chromatography-mass spectrometry (LCMS) vs. ELISA assays for measuring hair cortisol (n=28). The extraction process included sequential incubations in methanol and acetone, repeated twice. Hair protein was measured via spectrophotometric ratios at 260/280 nm to indicate the hair dissolution state using a BioTek® plate reader and dedicated software. Hair cortisol was measured using an ELISA assay kit. Individual (n=13), pooled hair samples (n=12) with high, intermediate, and low cortisol values and the ELISA assay internal standards (n=3) were also evaluated by LCMS. Results Milled and standard methods showed highly correlated hair cortisol (rs=0.951, p<0.0001) and protein values (rs=0.902, p=0.0002), although higher yields of cortisol and protein were obtained from the standard method in 13/16 and 14/16 samples respectively (p<0.05). Four sequential extractions yielded additional amounts of protein (36.5%, 27.5%, 30.5%, 3.1%) and cortisol (45.4%, 31.1%, 15.1%, 0.04%) from hair samples. Cortisol values measured by LCMS and ELISA were correlated (rs=0.737; p<0.0001), although cortisol levels (median [IQR]) detected in the same samples by LCMS (38.7 [14.4, 136] ng/ml) were lower than by ELISA (172.2 [67.9, 1051] ng/ml). LCMS also detected cortisone, which comprised 13.4% (3.7%, 25.9%) of the steroids detected. Conclusion Methodological studies suggest that finely cutting hair with sequential incubations in methanol and acetone, repeated twice, extracts greater yields of cortisol than does milled hair. Based on these findings, at least three incubations may be required to extract most of the cortisol in human hair samples. In addition, ELISA-based assays showed greater sensitivity for measuring hair cortisol levels than LCMS-based assays. PMID:25811341

Multi-constituent synergism is responsible for anti-inflammatory effect of Azadirachta indica leaf extract.

PubMed

Umar, Muhammad Ihtisham; Asmawi, Mohd Zaini; Sadikun, Amirin; Abdul Majid, A M S; Atangwho, Item Justin; Khadeer Ahamed, Mohamed B; Altaf, Rabia; Ahmad, Ashfaq

2014-11-01

Azadirachta indica A. Juss. (Meliaceaes) leaves have been used traditionally to treat swelling and rheumatism in Indian cultures. To fractionate A. indica leaf extracts using bioactivity guided manner for identification of the active anti-inflammatory principles. Polarity-gradient sequential extracts (petroleum ether, chloroform, methanol, and water) of A. indica leaves were screened for their anti-inflammatory potential using the carrageenan-induced rat paw edema model (1 g/kg). The chloroform extract was sequentially fractionated to obtain n-hexane (F-1), n-hexane-chloroform (F-2), and chloroform (F-3) fractions and their inhibitory effect on rat paw edema was evaluated (500 mg/kg). Inhibitory effect of F-2 on granuloma formation, plasma interleukin (IL-1), and tumor necrosis factor (TNF-α) was assessed at the doses of 100, 200, and 400 mg/kg using the cotton pellet assay in rats. Three sub-fractions (SF-1, SF-2, and SF-3) were obtained upon chromatography of F-2, and their inhibitory effect on cyclooxygenase was assessed at 200 µg/mL concentration. The sub-fractions were subjected to gas chromatography-mass spectrometry (GC-MS). All the extracts showed significant anti-inflammatory effect; however, chloroform extract was the most effective against paw edema (53.25% inhibition). The three fractions of chloroform extract showed significant effect, while F-2 being the most potent (51.02%). F-2 demonstrated dose-dependent inhibition of granuloma and cytokines. Interestingly, all the sub-fractions of F-2 inhibited COX-1 and COX-2 with almost equal potential. GC-MS revealed that chemically the sub-fractions were totally different from each other. Anti-inflammatory effect of A. indica is a result of cumulative and synergistic effects of diversified constituents with varying polarities that collectively exert the effect via suppression of cyclo-oxygenases and cytokines (IL-1 and TNF-α).

ANALYSIS OF SEQUENTIAL FAILURES FOR ASSESSMENT OF RELIABILITY AND SAFETY OF MANUFACTURING SYSTEMS. (R828541)

EPA Science Inventory

Assessment of reliability and safety of a manufacturing system with sequential failures is an important issue in industry, since the reliability and safety of the system depend not only on all failed states of system components, but also on the sequence of occurrences of those...

Hemodynamic analysis of sequential graft from right coronary system to left coronary system.

PubMed

Wang, Wenxin; Mao, Boyan; Wang, Haoran; Geng, Xueying; Zhao, Xi; Zhang, Huixia; Xie, Jinsheng; Zhao, Zhou; Lian, Bo; Liu, Youjun

2016-12-28

Sequential and single grafting are two surgical procedures of coronary artery bypass grafting. However, it remains unclear if the sequential graft can be used between the right and left coronary artery system. The purpose of this paper is to clarify the possibility of right coronary artery system anastomosis to left coronary system. A patient-specific 3D model was first reconstructed based on coronary computed tomography angiography (CCTA) images. Two different grafts, the normal multi-graft (Model 1) and the novel multi-graft (Model 2), were then implemented on this patient-specific model using virtual surgery techniques. In Model 1, the single graft was anastomosed to right coronary artery (RCA) and the sequential graft was adopted to anastomose left anterior descending (LAD) and left circumflex artery (LCX). While in Model 2, the single graft was anastomosed to LAD and the sequential graft was adopted to anastomose RCA and LCX. A zero-dimensional/three-dimensional (0D/3D) coupling method was used to realize the multi-scale simulation of both the pre-operative and two post-operative models. Flow rates in the coronary artery and grafts were obtained. The hemodynamic parameters were also showed, including wall shear stress (WSS) and oscillatory shear index (OSI). The area of low WSS and OSI in Model 1 was much less than that in Model 2. Model 1 shows optimistic hemodynamic modifications which may enhance the long-term patency of grafts. The anterior segments of sequential graft have better long-term patency than the posterior segments. With rational spatial position of the heart vessels, the last anastomosis of sequential graft should be connected to the main branch.

MSFC Skylab airlock module, volume 1. [systems design and performance

NASA Technical Reports Server (NTRS)

1974-01-01

The history and development of the Skylab Airlock Module and Payload Shroud is presented from initial concept through final design. A summary is given of the Airlock features and systems. System design and performance are presented for the Spent Stage Experiment Support Module, structure and mechanical systems, mass properties, thermal and environmental control systems, EVA/IVA suite system, electrical power system, sequential system, sequential system, and instrumentation system.

Model-Based Detection of Radioactive Contraband for Harbor Defense Incorporating Compton Scattering Physics

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

Candy, J V; Chambers, D H; Breitfeller, E F

2010-03-02

The detection of radioactive contraband is a critical problem is maintaining national security for any country. Photon emissions from threat materials challenge both detection and measurement technologies especially when concealed by various types of shielding complicating the transport physics significantly. This problem becomes especially important when ships are intercepted by U.S. Coast Guard harbor patrols searching for contraband. The development of a sequential model-based processor that captures both the underlying transport physics of gamma-ray emissions including Compton scattering and the measurement of photon energies offers a physics-based approach to attack this challenging problem. The inclusion of a basic radionuclide representationmore » of absorbed/scattered photons at a given energy along with interarrival times is used to extract the physics information available from the noisy measurements portable radiation detection systems used to interdict contraband. It is shown that this physics representation can incorporated scattering physics leading to an 'extended' model-based structure that can be used to develop an effective sequential detection technique. The resulting model-based processor is shown to perform quite well based on data obtained from a controlled experiment.« less

Gene expression profiling gut microbiota in different races of humans

NASA Astrophysics Data System (ADS)

Chen, Lei; Zhang, Yu-Hang; Huang, Tao; Cai, Yu-Dong

2016-03-01

The gut microbiome is shaped and modified by the polymorphisms of microorganisms in the intestinal tract. Its composition shows strong individual specificity and may play a crucial role in the human digestive system and metabolism. Several factors can affect the composition of the gut microbiome, such as eating habits, living environment, and antibiotic usage. Thus, various races are characterized by different gut microbiome characteristics. In this present study, we studied the gut microbiomes of three different races, including individuals of Asian, European and American races. The gut microbiome and the expression levels of gut microbiome genes were analyzed in these individuals. Advanced feature selection methods (minimum redundancy maximum relevance and incremental feature selection) and four machine-learning algorithms (random forest, nearest neighbor algorithm, sequential minimal optimization, Dagging) were employed to capture key differentially expressed genes. As a result, sequential minimal optimization was found to yield the best performance using the 454 genes, which could effectively distinguish the gut microbiomes of different races. Our analyses of extracted genes support the widely accepted hypotheses that eating habits, living environments and metabolic levels in different races can influence the characteristics of the gut microbiome.

Gene expression profiling gut microbiota in different races of humans

PubMed Central

Chen, Lei; Zhang, Yu-Hang; Huang, Tao; Cai, Yu-Dong

2016-01-01

The gut microbiome is shaped and modified by the polymorphisms of microorganisms in the intestinal tract. Its composition shows strong individual specificity and may play a crucial role in the human digestive system and metabolism. Several factors can affect the composition of the gut microbiome, such as eating habits, living environment, and antibiotic usage. Thus, various races are characterized by different gut microbiome characteristics. In this present study, we studied the gut microbiomes of three different races, including individuals of Asian, European and American races. The gut microbiome and the expression levels of gut microbiome genes were analyzed in these individuals. Advanced feature selection methods (minimum redundancy maximum relevance and incremental feature selection) and four machine-learning algorithms (random forest, nearest neighbor algorithm, sequential minimal optimization, Dagging) were employed to capture key differentially expressed genes. As a result, sequential minimal optimization was found to yield the best performance using the 454 genes, which could effectively distinguish the gut microbiomes of different races. Our analyses of extracted genes support the widely accepted hypotheses that eating habits, living environments and metabolic levels in different races can influence the characteristics of the gut microbiome. PMID:26975620

Revascularization of Left Coronary System Using a Skeletonized Left Internal Mammary Artery　- Sequential vs. Separate Grafting.

PubMed

Ji, Qiang; Shi, YunQing; Xia, LiMin; Ma, RunHua; Shen, JinQiang; Lai, Hao; Ding, WenJun; Wang, ChunSheng

2017-12-25

To evaluate in-hospital and mid-term outcomes of sequential vs. separate grafting of in situ skeletonized left internal mammary artery (LIMA) to the left coronary system in a single-center, propensity-matched study.Methods and Results:After propensity score-matching, 120 pairs of patients undergoing first scheduled isolated coronary artery bypass grafting (CABG) with in situ skeletonized LIMA grafting to the left anterior descending artery (LAD) territory were entered into a sequential group (sequential grafting of LIMA to the diagonal artery and then to the LAD) or a control group (separate grafting of LIMA to the LAD). The in-hospital and follow-up clinical outcomes and follow-up LIMA graft patency were compared. Both propensity score-matched groups had similar in-hospital and follow-up clinical outcomes. Sequential LIMA grafting was not found to be an independent predictor of adverse events. During a follow-up period of 27.0±7.3 months, 99.1% patency for the diagonal site and 98.3% for the LAD site were determined by coronary computed tomographic angiography after sequential LIMA grafting, both of which were similar with graft patency of separate grafting of in situ skeletonized LIMA to the LAD. Revascularization of the left coronary system using a skeletonized LIMA resulted in excellent in-hospital and mid-term clinical outcomes and graft patency using sequential grafting.

SU-E-J-59: Feasibility of Markerless Tumor Tracking by Sequential Dual-Energy Fluoroscopy On a Clinical Tumor Tracking System

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

Dhont, J; Poels, K; Verellen, D

2015-06-15

Purpose: To evaluate the feasibility of markerless tumor tracking through the implementation of a novel dual-energy imaging approach into the clinical dynamic tracking (DT) workflow of the Vero SBRT system. Methods: Two sequential 20 s (11 Hz) fluoroscopy sequences were acquired at the start of one fraction for 7 patients treated for primary and metastatic lung cancer with DT on the Vero system. Sequences were acquired using 2 on-board kV imaging systems located at ±45° from the MV beam axis, at respectively 60 kVp (3.2 mAs) and 120 kVp (2.0 mAs). Offline, a normalized cross-correlation algorithm was applied to matchmore » the high (HE) and low energy (LE) images. Per breathing phase (inhale, exhale, maximum inhale and maximum exhale), the 5 best-matching HE and LE couples were extracted for DE subtraction. A contrast analysis according to gross tumor volume was conducted based on contrast-to-noise ratio (CNR). Improved tumor visibility was quantified using an improvement ratio. Results: Using the implanted fiducial as a benchmark, HE-LE sequence matching was effective for 13 out of 14 imaging angles. Overlying bony anatomy was removed on all DE images. With the exception of two imaging angles, the DE images showed no significantly improved tumor visibility compared to HE images, with an improvement ratio averaged over all patients of 1.46 ± 1.64. Qualitatively, it was observed that for those imaging angles that showed no significantly improved CNR, the tumor tissue could not be reliably visualized on neither HE nor DE images due to a total or partial overlap with other soft tissue. Conclusion: Dual-energy subtraction imaging by sequential orthogonal fluoroscopy was shown feasible by implementing an additional LE fluoroscopy sequence. However, for most imaging angles, DE images did not provide improved tumor visibility over single-energy images. Optimizing imaging angles is likely to improve tumor visibility and the efficacy of dual-energy imaging. This work was in part sponsored by corporate funding from BrainLAB AG.(BrainLAB AG, Feldkirchen, Germany)« less

Hybrid Semantic Analysis for Mapping Adverse Drug Reaction Mentions in Tweets to Medical Terminology.

PubMed

Emadzadeh, Ehsan; Sarker, Abeed; Nikfarjam, Azadeh; Gonzalez, Graciela

2017-01-01

Social networks, such as Twitter, have become important sources for active monitoring of user-reported adverse drug reactions (ADRs). Automatic extraction of ADR information can be crucial for healthcare providers, drug manufacturers, and consumers. However, because of the non-standard nature of social media language, automatically extracted ADR mentions need to be mapped to standard forms before they can be used by operational pharmacovigilance systems. We propose a modular natural language processing pipeline for mapping (normalizing) colloquial mentions of ADRs to their corresponding standardized identifiers. We seek to accomplish this task and enable customization of the pipeline so that distinct unlabeled free text resources can be incorporated to use the system for other normalization tasks. Our approach, which we call Hybrid Semantic Analysis (HSA), sequentially employs rule-based and semantic matching algorithms for mapping user-generated mentions to concept IDs in the Unified Medical Language System vocabulary. The semantic matching component of HSA is adaptive in nature and uses a regression model to combine various measures of semantic relatedness and resources to optimize normalization performance on the selected data source. On a publicly available corpus, our normalization method achieves 0.502 recall and 0.823 precision (F-measure: 0.624). Our proposed method outperforms a baseline based on latent semantic analysis and another that uses MetaMap.

Assessment of soil stabilization by chemical extraction and bioaccumulation using earthworm, Eisenia fetida

NASA Astrophysics Data System (ADS)

Lee, Byung-Tae; Abd Aziz, Azilah; Han, Heop Jo; Kim, Kyoung-Woong

2014-05-01

Soil stabilization does not remove heavy metals from contaminated soil, but lowers their exposures to ecosystem. Thus, it should be evaluated by measuring the fractions of heavy metals which are mobile and/or bioavailable in soils. The study compared several chemical extractions which intended to quantify the mobile or bioaccessible fractions with uptake and bioaccumulation by earthworm, Eisenia fetida. Soil samples were taken from the abandoned mine area contaminated with As, Cd, Cu, Pb and/or Zn. To stabilize heavy metals, the soils were amended with limestone and steel slag at 5% and 2% (w/w), respectively. All chemical extractions and earthworm tests were applied to both the contaminated and the stabilized soils with triplicates. The chemical extractions consisted of six single extractions which were 0.01M CaCl2 (unbufferred), EDTA or DTPA (chelating), TCLP (acidic), Mehlich 3 (mixture), and aqua regia (peudo-total). Sequential extractions were also applied to fractionate heavy metals in soils. In earthworm tests, worms were exposed to the soils for uptake of heavy metals. After 28 days of exposure to soils, worms were transferred to clean soils for elimination. During the tests, three worms were randomly collected at proper sampling events. Worms were rinsed with DI water and placed on moist filter paper for 48 h for depuration. Filter paper was renewed at 24 h to prevent coprophagy. The worms were killed with liquid nitrogen, dried in the oven, and digested with aqua regia for ICP-MS analysis. In addition to the bioaccumulation, several toxicity endpoints were observed such as burrowing time, mortality, cocoon production, and body weight changes. Toxicokinetics was applied to determine the uptake and elimination heavy metals by the earthworms. Bioaccumulation factor (BAF) was estimated using total metal concentrations and body burdens. Pearson correlation and simple linear regression were applied to evaluate the relationship between metal fractions by single extractions or sequential extractions with bioaccumulations. Finally, we discussed the advantages or disadvantages of simple chemical extractions which are commonly used to estimate the efficacy of stabilization.

Automated texture-based identification of ovarian cancer in confocal microendoscope images

NASA Astrophysics Data System (ADS)

Srivastava, Saurabh; Rodriguez, Jeffrey J.; Rouse, Andrew R.; Brewer, Molly A.; Gmitro, Arthur F.

2005-03-01

The fluorescence confocal microendoscope provides high-resolution, in-vivo imaging of cellular pathology during optical biopsy. There are indications that the examination of human ovaries with this instrument has diagnostic implications for the early detection of ovarian cancer. The purpose of this study was to develop a computer-aided system to facilitate the identification of ovarian cancer from digital images captured with the confocal microendoscope system. To achieve this goal, we modeled the cellular-level structure present in these images as texture and extracted features based on first-order statistics, spatial gray-level dependence matrices, and spatial-frequency content. Selection of the best features for classification was performed using traditional feature selection techniques including stepwise discriminant analysis, forward sequential search, a non-parametric method, principal component analysis, and a heuristic technique that combines the results of these methods. The best set of features selected was used for classification, and performance of various machine classifiers was compared by analyzing the areas under their receiver operating characteristic curves. The results show that it is possible to automatically identify patients with ovarian cancer based on texture features extracted from confocal microendoscope images and that the machine performance is superior to that of the human observer.

The Emotion Recognition System Based on Autoregressive Model and Sequential Forward Feature Selection of Electroencephalogram Signals

PubMed Central

Hatamikia, Sepideh; Maghooli, Keivan; Nasrabadi, Ali Motie

2014-01-01

Electroencephalogram (EEG) is one of the useful biological signals to distinguish different brain diseases and mental states. In recent years, detecting different emotional states from biological signals has been merged more attention by researchers and several feature extraction methods and classifiers are suggested to recognize emotions from EEG signals. In this research, we introduce an emotion recognition system using autoregressive (AR) model, sequential forward feature selection (SFS) and K-nearest neighbor (KNN) classifier using EEG signals during emotional audio-visual inductions. The main purpose of this paper is to investigate the performance of AR features in the classification of emotional states. To achieve this goal, a distinguished AR method (Burg's method) based on Levinson-Durbin's recursive algorithm is used and AR coefficients are extracted as feature vectors. In the next step, two different feature selection methods based on SFS algorithm and Davies–Bouldin index are used in order to decrease the complexity of computing and redundancy of features; then, three different classifiers include KNN, quadratic discriminant analysis and linear discriminant analysis are used to discriminate two and three different classes of valence and arousal levels. The proposed method is evaluated with EEG signals of available database for emotion analysis using physiological signals, which are recorded from 32 participants during 40 1 min audio visual inductions. According to the results, AR features are efficient to recognize emotional states from EEG signals, and KNN performs better than two other classifiers in discriminating of both two and three valence/arousal classes. The results also show that SFS method improves accuracies by almost 10-15% as compared to Davies–Bouldin based feature selection. The best accuracies are %72.33 and %74.20 for two classes of valence and arousal and %61.10 and %65.16 for three classes, respectively. PMID:25298928

Simultaneous Versus Sequential Side-by-Side Bilateral Metal Stent Placement for Malignant Hilar Biliary Obstructions.

PubMed

Inoue, Tadahisa; Ishii, Norimitsu; Kobayashi, Yuji; Kitano, Rena; Sakamoto, Kazumasa; Ohashi, Tomohiko; Nakade, Yukiomi; Sumida, Yoshio; Ito, Kiyoaki; Nakao, Haruhisa; Yoneda, Masashi

2017-09-01

Endoscopic bilateral self-expandable metallic stent (SEMS) placement for malignant hilar biliary obstructions (MHBOs) is technically demanding, and a second SEMS insertion is particularly challenging. A simultaneous side-by-side (SBS) placement technique using a thinner delivery system may mitigate these issues. We aimed to examine the feasibility and efficacy of simultaneous SBS SEMS placement for treating MHBOs using a novel SEMS that has a 5.7-Fr ultra-thin delivery system. Thirty-four patients with MHBOs underwent SBS SEMS placement between 2010 and 2016. We divided the patient cohort into those who underwent sequential (conventional) SBS placement between 2010 and 2014 (sequential group) and those who underwent simultaneous SBS placement between 2015 and 2016 (simultaneous group), and compared the groups with respect to the clinical outcomes. The technical success rates were 71% (12/17) and 100% (17/17) in the sequential and simultaneous groups, respectively, a difference that was significant (P = .045). The median procedure time was significantly shorter in the simultaneous group (22 min) than in the sequential group (52 min) (P = .017). There were no significant group differences in the time to recurrent biliary obstruction (sequential group: 113 days; simultaneous group: 140 days) or other adverse event rates (sequential group: 12%; simultaneous group: 12%). Simultaneous SBS placement using the novel 5.7-Fr SEMS delivery system may be more straightforward and have a higher success rate compared to that with sequential SBS placement. This new method may be useful for bilateral stenting to treat MHBOs.

Determining the speciation of Zn in soils around the sediment ponds of chemical plants by XRD and XAFS spectroscopy and sequential extraction.

PubMed

Minkina, Tatiana; Nevidomskaya, Dina; Bauer, Tatiana; Shuvaeva, Victoria; Soldatov, Alexander; Mandzhieva, Saglara; Zubavichus, Yan; Trigub, Alexander

2018-09-01

For a correct assessment of risk of polluted soil, it is crucial to establish the speciation and mobility of the contaminants. The aim of this study was to investigate the speciation and transformation of Zn in strongly technogenically transformed contaminated Spolic Technosols for a long time in territory of sludge collectors by combining analytical techniques and synchrotron techniques. Sequential fractionation of Zn compounds in studied soils revealed increasing metal mobility. Phyllosilicates and Fe and Mn hydroxides were the main stabilizers of Zn mobility. A high degree of transformation was identified for the composition of the mineral phase in Spolic Technosols by X-ray powder diffraction. Technogenic phases (Zn-containing authigenic minerals) were revealed in Spolic Technosols samples through the analysis of their Zn K-edge EXAFS and XANES spectra. In one of the samples Zn local environment was formed by predominantly oxygen atoms, and in the other one mixed ZnS and ZnO bonding was found. Zn speciation in the studied technogenically transformed soils was due to the composition of pollutants contaminating the floodplain landscapes for a long time, and, second, this is the combination of physicochemical properties controlling the buffer properties of investigated soils. X-ray spectroscopic and X-ray powder diffraction analyses combined with sequential extraction assays is an effective tool to check the affinity of the soil components for heavy metal cations. Copyright © 2018 Elsevier B.V. All rights reserved.

Method of Real-Time Principal-Component Analysis

NASA Technical Reports Server (NTRS)

Duong, Tuan; Duong, Vu

2005-01-01

Dominant-element-based gradient descent and dynamic initial learning rate (DOGEDYN) is a method of sequential principal-component analysis (PCA) that is well suited for such applications as data compression and extraction of features from sets of data. In comparison with a prior method of gradient-descent-based sequential PCA, this method offers a greater rate of learning convergence. Like the prior method, DOGEDYN can be implemented in software. However, the main advantage of DOGEDYN over the prior method lies in the facts that it requires less computation and can be implemented in simpler hardware. It should be possible to implement DOGEDYN in compact, low-power, very-large-scale integrated (VLSI) circuitry that could process data in real time.

Automatic extraction of building boundaries using aerial LiDAR data

NASA Astrophysics Data System (ADS)

Wang, Ruisheng; Hu, Yong; Wu, Huayi; Wang, Jian

2016-01-01

Building extraction is one of the main research topics of the photogrammetry community. This paper presents automatic algorithms for building boundary extractions from aerial LiDAR data. First, segmenting height information generated from LiDAR data, the outer boundaries of aboveground objects are expressed as closed chains of oriented edge pixels. Then, building boundaries are distinguished from nonbuilding ones by evaluating their shapes. The candidate building boundaries are reconstructed as rectangles or regular polygons by applying new algorithms, following the hypothesis verification paradigm. These algorithms include constrained searching in Hough space, enhanced Hough transformation, and the sequential linking technique. The experimental results show that the proposed algorithms successfully extract building boundaries at rates of 97%, 85%, and 92% for three LiDAR datasets with varying scene complexities.

BCR®-701: a review of 10-years of sequential extraction analyses.

PubMed

Sutherland, Ross A

2010-11-08

A detailed quantitative analysis was performed on data presented in the literature that focused on the sequential extraction of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) from the certified reference material BCR-701 (lake sediment) using the three-step harmonized BCR(®) procedure. The accuracy of data reported in the literature, including precision and different measures of trueness, was assessed relative to the certified values for BCR-701. Forty data sets were accepted following extreme outlier removal, and statistically summarized with measures of central tendency, dispersion, and distribution form. In general, literature data were similar in their measurement precision to the expert laboratories used to certify the trace element contents in BCR-701. The overall median precision for literature reported data was 10% (range 6-19%), compared to certifying laboratories of 9% (range 4-33%). One measure of literature data trueness was assessed via a confirmatory approach using a robust bootstrap method. Only 22% of the comparisons indicated significantly different (all were lower) concentrations reported in the literature compared to certified values. The question of whether the differences are practically significant for environmental studies is raised. Bias was computed as a measure of trueness, and literature data were more frequently negatively biased, indicating lower concentrations reported in the literature for the six trace elements for the three-step sequential procedure compared to the certified values. However, 95% confidence intervals about the average bias for the 18 comparisons indicated only four instances when a mean bias of 0 (i.e., measured=certified) was not incorporated-suggesting statistical difference. Finally, Z-scores incorporating a Horwitz-type function were used to assess the general trueness of laboratory data. Of the 468 laboratory Z-score values computed, 92% were considered to be satisfactory, 5% were questionable, and 3% were unsatisfactory. A detailed examination of the methodology sections of the various studies showed that despite claiming adherence to the harmonized BCR sequential extraction protocol, significant deviations were commonly observed; particularly in moisture correction, sample mass, centrifugation specifics, shaking specifics, and incorporation of filtration. It is likely that failure to strictly adhere to the protocol adversely impacted accuracy, by increasing the degree of imprecision and resulting in more discrepant trueness values. Copyright © 2010 Elsevier B.V. All rights reserved.

Pulsed counter-current ultrasound-assisted extraction and characterization of polysaccharides from Boletus edulis.

PubMed

You, Qinghong; Yin, Xiulian; Ji, Chaowen

2014-01-30

Four methods for extracting polysaccharides from Boletus edulis, namely, hot-water extraction, ultrasonic clearer extraction, static probe ultrasonic extraction, and pulsed counter-current probe ultrasonic extraction (CCPUE), were studied. Results showed that CCPUE has the highest extraction efficiency among the methods studied. Under optimal CCPUE conditions, a B. edulis polysaccharide (BEP) yield of 8.21% was obtained. Three purified fractions, BEP-I, BEP-II, and BEP-III, were obtained through sequential purification by DEAE-52 and Sephadex G-75 chromatography. The average molecular weights of BEP-I, BEP-II, and BEP-III were 10,278, 23,761, and 42,736 Da, respectively. The polysaccharides were mainly composed of xylose, mannose, galactose, and glucose; of these, mannose contents were the highest. The antioxidant activities of the BEPs were further investigated by measurement of their ability to scavenge DPPH and hydroxyl radicals as well as their reducing power. The results indicated that the BEPs have good antioxidant activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sequential single shot X-ray photon correlation spectroscopy at the SACLA free electron laser

DOE PAGES

Lehmkühler, Felix; Kwaśniewski, Paweł; Roseker, Wojciech; ...

2015-11-27

In this study, hard X-ray free electron lasers allow for the first time to access dynamics of condensed matter samples ranging from femtoseconds to several hundred seconds. In particular, the exceptional large transverse coherence of the X-ray pulses and the high time-averaged flux promises to reach time and length scales that have not been accessible up to now with storage ring based sources. However, due to the fluctuations originating from the stochastic nature of the self-amplified spontaneous emission (SASE) process the application of well established techniques such as X-ray photon correlation spectroscopy (XPCS) is challenging. Here we demonstrate a single-shotmore » based sequential XPCS study on a colloidal suspension with a relaxation time comparable to the SACLA free-electron laser pulse repetition rate. High quality correlation functions could be extracted without any indications for sample damage. This opens the way for systematic sequential XPCS experiments at FEL sources.« less

Sequential single shot X-ray photon correlation spectroscopy at the SACLA free electron laser

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

Lehmkühler, Felix; Kwaśniewski, Paweł; Roseker, Wojciech

In this study, hard X-ray free electron lasers allow for the first time to access dynamics of condensed matter samples ranging from femtoseconds to several hundred seconds. In particular, the exceptional large transverse coherence of the X-ray pulses and the high time-averaged flux promises to reach time and length scales that have not been accessible up to now with storage ring based sources. However, due to the fluctuations originating from the stochastic nature of the self-amplified spontaneous emission (SASE) process the application of well established techniques such as X-ray photon correlation spectroscopy (XPCS) is challenging. Here we demonstrate a single-shotmore » based sequential XPCS study on a colloidal suspension with a relaxation time comparable to the SACLA free-electron laser pulse repetition rate. High quality correlation functions could be extracted without any indications for sample damage. This opens the way for systematic sequential XPCS experiments at FEL sources.« less

Smartphone home monitoring of ECG

NASA Astrophysics Data System (ADS)

Szu, Harold; Hsu, Charles; Moon, Gyu; Landa, Joseph; Nakajima, Hiroshi; Hata, Yutaka

2012-06-01

A system of ambulatory, halter, electrocardiography (ECG) monitoring system has already been commercially available for recording and transmitting heartbeats data by the Internet. However, it enjoys the confidence with a reservation and thus a limited market penetration, our system was targeting at aging global villagers having an increasingly biomedical wellness (BMW) homecare needs, not hospital related BMI (biomedical illness). It was designed within SWaP-C (Size, Weight, and Power, Cost) using 3 innovative modules: (i) Smart Electrode (lowpower mixed signal embedded with modern compressive sensing and nanotechnology to improve the electrodes' contact impedance); (ii) Learnable Database (in terms of adaptive wavelets transform QRST feature extraction, Sequential Query Relational database allowing home care monitoring retrievable Aided Target Recognition); (iii) Smartphone (touch screen interface, powerful computation capability, caretaker reporting with GPI, ID, and patient panic button for programmable emergence procedure). It can provide a supplementary home screening system for the post or the pre-diagnosis care at home with a build-in database searchable with the time, the place, and the degree of urgency happened, using in-situ screening.

Smart Occupancy Sensor Debuts - Continuum Magazine | NREL

Science.gov Websites

occupancy, IPOS uses sequential image subtractions like this one for extracting and analyzing motion building energy performance. Noted as one of the 100 most significant innovations of 2013 by R&D device where one edge of the IC is exposed. In the background is a blackboard on which computer

PATTERN RECOGNITION APPROACH TO MEDICAL DIAGNOSIS,

DTIC Science & Technology

A sequential method of pattern recognition was used to recognize hyperthyroidism in a sample of 2219 patients being treated at the Straub Clinic in...the most prominent class features are selected. Thus, the symptoms which best distinguish hyperthyroidism are extracted at every step and the number of tests required to reach a diagnosis is reduced. (Author)

Chromium, nickel and vanadium mobility in soils derived from fluvioglacial sands.

PubMed

Agnieszka, Jeske; Barbara, Gworek

2012-10-30

The presented study was focused on soils developed from fluvioglacial sands from the Puszcza Borecka forest complex. The mobility of chromium, nickel and vanadium was evaluated with regard to litho- and pedogenic factors. The aim of the study was to determine with which soil constituents fractions of heavy metals are bound with particular attention drawn on the mobile fractions (F1+F2). Heavy metal fractions in the soils were determined using the sequential extraction method of Tessier et al. The purpose of sequential extraction methods to soil samples provides relevant information about possible toxicity when they are discharged into the soil environment. Chromium, nickel, and vanadium occurred predominantly in the fraction bound with iron and manganese oxides and in the residual fraction, thus showed low mobility. With regard to mobility, the elements studied can be arranged as follows: V

Arsenic release from arsenopyrite weathering: insights from sequential extraction and microscopic studies.

PubMed

Basu, Ankan; Schreiber, Madeline E

2013-11-15

At a former As mine site, arsenopyrite oxidation has resulted in formation of scorodite and As-bearing iron hydroxide, both in host rock and mine tailings. Electron microprobe analysis documents that arsenopyrite weathers along two pathways: one that involves formation of sulfur, and one that does not. In both pathways, arsenopyrite oxidizes to form scorodite, which dissolves incongruently to form As-bearing iron hydroxides. From a mass balance perspective, arsenopyrite oxidation to scorodite conserves As, but as scorodite dissolves incongruently to iron hydroxides, As is released to solution, resulting in elevated As concentrations in the headwater stream adjacent to the site. The As-bearing iron hydroxide is the dominant solid phase reservoir of As in mine tailings and stream sediment, as suggested by sequential extraction. This As-bearing iron hydroxide is stable under the aerobic and pH 4-6 conditions at the site; however, changes in biogeochemical conditions resulting from sediment burial or future remedial efforts, which could promote As release from this reservoir due to reductive dissolution, should be avoided. Copyright © 2012 Elsevier B.V. All rights reserved.

Study on demetalization of sewage sludge by sequential extraction before liquefaction for the production of cleaner bio-oil and bio-char.

PubMed

Leng, Lijian; Yuan, Xingzhong; Shao, Jianguang; Huang, Huajun; Wang, Hou; Li, Hui; Chen, Xiaohong; Zeng, Guangming

2016-01-01

Demetalization of sewage sludge (SS) by sequential extraction before liquefaction was implemented to produce cleaner bio-char and bio-oil. Demetalization steps 1 and 2 did not cause much organic matter loss on SS, and thus the bio-oil and bio-char yields and the compositions of bio-oils were also not affected significantly. However, the demetalization procedures resulted in the production of cleaner bio-chars and bio-oils. The total concentrations and the acid soluble/exchangeable fraction (F1 fraction, the most toxic heavy metal fraction) of heavy metals (Cu, Cr, Pb, Zn, and Cd) in these products were significantly reduced and the environmental risks of these products were also relived considerably compared with those produced from raw SS, respectively. Additionally, these bio-oils had less heavy fractions. Demetalization processes with removal of F1 and F2 fractions of heavy metals would benefit the production of cleaner bio-char and bio-oil by liquefaction of heavy metal abundant biomass like SS. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluating the Mobility of Arsenic in Synthetic Iron-containing Solids Using a Modified Sequential Extraction Method

PubMed Central

Shan, Jilei; Sáez, A. Eduardo; Ela, Wendell P.

2013-01-01

Many water treatment technologies for arsenic removal that are used today produce arsenic-bearing residuals which are disposed in non-hazardous landfills. Previous works have established that many of these residuals will release arsenic to a much greater extent than predicted by standard regulatory leaching tests (e.g. the toxicity characteristic leaching procedure, TCLP) and, consequently, require stabilization to ensure benign behavior after disposal. In this work, a four-step sequential extraction method was developed in an effort to determine the proportion of arsenic in various phases in untreated as well as stabilized iron-based solid matrices. The solids synthesized using various potential stabilization techniques included: amorphous arsenic-iron sludge (ASL), reduced ASL via reaction with zero valent iron (RASL), amorphous ferrous arsenate (PFA), a mixture of PFA and SL (M1), crystalline ferrous arsenate (HPFA), and a mixture of HPFA and SL (M2). The overall arsenic mobility of the tested samples increased in the following order: ASL > RASL > PFA > M1 > HPFA > M2. PMID:23459695

Enrichment desired quality chitosan fraction and advance yield by sequential static and static-dynamic supercritical CO2.

PubMed

Hsieh, Yi-Yin; Chin, Hui Yen; Tsai, Min-Lang

2015-11-20

This study aimed to establish the sequential static and static-dynamic supercritical carbon dioxide (SDCO2) fractionation conditions to obtain a higher yield and desired chitosan with lower polydispersity index (PDI) and higher degree of deacetylation (DD). The yield increased with increasing DD of used chitosan and amount of cosolvent. The yield of acetic acid cosolvent was higher than those of malic and citric acid cosolvents. SDCO2, compared to static supercritical carbon dioxide, has higher yield. The yield of extracted chitosan was 5.82-14.70% by SDCO2/acetic acid, which increases with increasing pressure. The DD of fractionated chitosan increased from 66.1% to 70.81-85.33%, while the PDI decreased from 3.97 to 1.69-3.16. The molecular weight changed from 622kDa to 412-649kDa, which increased as density of supercritical carbon dioxide increases. Hence, higher DD and lower PDI extracted chitosan can be obtained through controlling the temperature and pressure of SDCO2. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of modified zeolite on the removal and stabilization of heavy metals in contaminated lake sediment using BCR sequential extraction.

PubMed

Wen, Jia; Yi, Yuanjie; Zeng, Guangming

2016-08-01

Sediment can be applied on land as a soil conditioner. However, toxic substances such as heavy metals within the sediment often lead to soil contamination if no proper management is conducted prior to land application. In order to reduce the bioavailable portion of heavy metals such as Pb, Cu, Zn and Cd, zeolite as a kind of stabilizer was investigated on the effect of metal stabilization in sediment. Zeolite was firstly modified and screened to get the best condition for removal of heavy metals. Results showed that the granulated zeolite with NaCl conditioning had the highest CEC and metal sorption. Using BCR sequential extraction, the selected modified zeolite effectively stabilized Pb, Cu, Zn and Cd in sediment to different extents. It was most suitable for Cd stabilization by reducing its acid exchangeable fraction while increasing the contents of the reducible and residual fractions. Modified zeolite also immobilized Cu, Zn and Pb in sediment by enhancing one stable fraction while decreasing the acid exchangeable fraction. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sequential Total Variation Denoising for the Extraction of Fetal ECG from Single-Channel Maternal Abdominal ECG

PubMed Central

Lee, Kwang Jin; Lee, Boreom

2016-01-01

Fetal heart rate (FHR) is an important determinant of fetal health. Cardiotocography (CTG) is widely used for measuring the FHR in the clinical field. However, fetal movement and blood flow through the maternal blood vessels can critically influence Doppler ultrasound signals. Moreover, CTG is not suitable for long-term monitoring. Therefore, researchers have been developing algorithms to estimate the FHR using electrocardiograms (ECGs) from the abdomen of pregnant women. However, separating the weak fetal ECG signal from the abdominal ECG signal is a challenging problem. In this paper, we propose a method for estimating the FHR using sequential total variation denoising and compare its performance with that of other single-channel fetal ECG extraction methods via simulation using the Fetal ECG Synthetic Database (FECGSYNDB). Moreover, we used real data from PhysioNet fetal ECG databases for the evaluation of the algorithm performance. The R-peak detection rate is calculated to evaluate the performance of our algorithm. Our approach could not only separate the fetal ECG signals from the abdominal ECG signals but also accurately estimate the FHR. PMID:27376296

Sequential Total Variation Denoising for the Extraction of Fetal ECG from Single-Channel Maternal Abdominal ECG.

PubMed

Lee, Kwang Jin; Lee, Boreom

2016-07-01

Fetal heart rate (FHR) is an important determinant of fetal health. Cardiotocography (CTG) is widely used for measuring the FHR in the clinical field. However, fetal movement and blood flow through the maternal blood vessels can critically influence Doppler ultrasound signals. Moreover, CTG is not suitable for long-term monitoring. Therefore, researchers have been developing algorithms to estimate the FHR using electrocardiograms (ECGs) from the abdomen of pregnant women. However, separating the weak fetal ECG signal from the abdominal ECG signal is a challenging problem. In this paper, we propose a method for estimating the FHR using sequential total variation denoising and compare its performance with that of other single-channel fetal ECG extraction methods via simulation using the Fetal ECG Synthetic Database (FECGSYNDB). Moreover, we used real data from PhysioNet fetal ECG databases for the evaluation of the algorithm performance. The R-peak detection rate is calculated to evaluate the performance of our algorithm. Our approach could not only separate the fetal ECG signals from the abdominal ECG signals but also accurately estimate the FHR.

Learning Sequential Composition Control.

PubMed

Najafi, Esmaeil; Babuska, Robert; Lopes, Gabriel A D

2016-11-01

Sequential composition is an effective supervisory control method for addressing control problems in nonlinear dynamical systems. It executes a set of controllers sequentially to achieve a control specification that cannot be realized by a single controller. As these controllers are designed offline, sequential composition cannot address unmodeled situations that might occur during runtime. This paper proposes a learning approach to augment the standard sequential composition framework by using online learning to handle unforeseen situations. New controllers are acquired via learning and added to the existing supervisory control structure. In the proposed setting, learning experiments are restricted to take place within the domain of attraction (DOA) of the existing controllers. This guarantees that the learning process is safe (i.e., the closed loop system is always stable). In addition, the DOA of the new learned controller is approximated after each learning trial. This keeps the learning process short as learning is terminated as soon as the DOA of the learned controller is sufficiently large. The proposed approach has been implemented on two nonlinear systems: 1) a nonlinear mass-damper system and 2) an inverted pendulum. The results show that in both cases a new controller can be rapidly learned and added to the supervisory control structure.

High data rate coding for the space station telemetry links.

NASA Technical Reports Server (NTRS)

Lumb, D. R.; Viterbi, A. J.

1971-01-01

Coding systems for high data rates were examined from the standpoint of potential application in space-station telemetry links. Approaches considered included convolutional codes with sequential, Viterbi, and cascaded-Viterbi decoding. It was concluded that a high-speed (40 Mbps) sequential decoding system best satisfies the requirements for the assumed growth potential and specified constraints. Trade-off studies leading to this conclusion are viewed, and some sequential (Fano) algorithm improvements are discussed, together with real-time simulation results.

On-line diagnosis of sequential systems

NASA Technical Reports Server (NTRS)

Sundstrom, R. J.

1973-01-01

A model for on-line diagnosis was investigated for discrete-time systems, and resettable sequential systems. Generalized notions of a realization are discussed along with fault tolerance and errors. Further investigation into the theory of on-line diagnosis is recommended for three levels: binary state-assigned level, logical circuit level, and the subsystem-network level.

Extraction of heavy metals from MSW incinerator fly ash using saponins.

PubMed

Hong, K J; Tokunaga, S; Ishigami, Y; Kajiuchi, T

2000-08-01

An extraction process with saponins was evaluated for removing heavy metals from MSW (municipal solid waste) incinerator fly ashes. Two different fly ashes, A and B, were treated on a laboratory scale with three triterpene-glycoside type of saponins, M, Q, and T, in the pH range 4-9. The results were compared with those of the HCI and EDTA treatment. The treatment with saponins extracted 20-45% of Cr from the fly ashes. Saponins were also effective in extracting Cu from fly ash A attaining 50-60% extraction. Saponin T extracted 100% of Pb from fly ash A at pH around 4. The extraction of Zn with the saponin treatment was similar to that of the HCl treatment. Further, Cr, Cu, Pb, and Zn were fractionated by sequential extraction to investigate the effect of saponins on each fraction. Extraction behavior of other elements during the saponin treatment was also studied. The leaching test on the residues received after the saponin treatment showed that the fly ashes were successfully detoxified to meet the landfilling guideline.

Adaptive x-ray threat detection using sequential hypotheses testing with fan-beam experimental data (Conference Presentation)

NASA Astrophysics Data System (ADS)

Thamvichai, Ratchaneekorn; Huang, Liang-Chih; Ashok, Amit; Gong, Qian; Coccarelli, David; Greenberg, Joel A.; Gehm, Michael E.; Neifeld, Mark A.

2017-05-01

We employ an adaptive measurement system, based on sequential hypotheses testing (SHT) framework, for detecting material-based threats using experimental data acquired on an X-ray experimental testbed system. This testbed employs 45-degree fan-beam geometry and 15 views over a 180-degree span to generate energy sensitive X-ray projection data. Using this testbed system, we acquire multiple view projection data for 200 bags. We consider an adaptive measurement design where the X-ray projection measurements are acquired in a sequential manner and the adaptation occurs through the choice of the optimal "next" source/view system parameter. Our analysis of such an adaptive measurement design using the experimental data demonstrates a 3x-7x reduction in the probability of error relative to a static measurement design. Here the static measurement design refers to the operational system baseline that corresponds to a sequential measurement using all the available sources/views. We also show that by using adaptive measurements it is possible to reduce the number of sources/views by nearly 50% compared a system that relies on static measurements.

Chemical investigations of male and female leaf extracts from Schinus molle L.

PubMed

Garzoli, Stefania; Laghezza Masci, Valentina; Turchetti, Giovanni; Pesci, Lorenzo; Tiezzi, Antonio; Ovidi, Elisa

2018-05-29

The pepper-tree Schinus molle is an evergreen ornamental plant with various and diversified list of medical uses. In this article we analysed the chemical composition of male and female leaves of this plant during the off-flowering and flowering seasons. The leaf extracts were obtained by using a sequential extraction with solvents of different polarities and the chemical composition was investigated by GC-MS. The results showed a total of twenty-three components, in which elemol is the most abundant constituent followed by bicyclogermacrene, γ-eudesmol, α-eudesmol, β-eudesmol and isocalamendiol. The petroleum ether and diethyl ether extracts from male and female flowering and off-flowering leaves consisted of sesquiterpene hydrocarbons as a major constituent followed by monoterpene hydrocarbons, while the acetone extracts showed a different composition. The obtained results show differences in the chemical composition between male and female and flowering and not flowering.

The Development of Molybdenum Speciation as a Paleoredox Tool

NASA Astrophysics Data System (ADS)

Rodley, J.; Peacock, C.; Mosselmans, J. F. W.; Poulton, S.

2017-12-01

The redox state of the oceans has changed throughout geological time and an understanding of these changes is essential to elucidate links between ocean chemistry, climate and life. Due to its abundance in seawater and redox-sensitive nature, molybdenum has enormous potential as a paleoredox proxy. Although a significant amount of research has been done on molybdenum in ancient and modern sediments in terms of its concentrations and isotopic ratios there remains a limited understanding of the drawdown mechanisms of molybdenum under different redox conditions restricting its use in identifying a range of redox states. In order to address these uncertainties, we have developed a novel sequential extraction technique to examine molybdenum concentrations in six sediment fractions from modern samples that represent oxic, nitrogenous, ferruginous and euxinic environments. In addition we use µ-XRF and µ-XANES synchrotron spectroscopy to examine the molybdenum speciation within these fractions and environments. To interpret our µ-XANES data we have developed an extensive library of molybdenum XANES standards that represent molybdenum sequestration by the sediment fractions identified from the sequential extraction. To further verify our synchrotron results we developed a series of µ-XANES micro-column experiments to examine preferential uptake pathways of molybdenum to different sediment phases under a euxinic water column. The initial data from both the sequential extraction and µ-XANES methods indicate that molybdenum is not limited to a single burial pathway in any of the redox environments. We find that each of the redox environments can be characterised by a limited set of molybdenum phase associations, with molybdenum adsorption to pyrite likely the dominant burial pathway. These findings agree with existing research for molybdenum speciation in euxinic environments suggesting that both pyrite and sulphidised organic matter act as important molybdenum sinks. Our new research shows that pyrite is also an important sink for molybdenum in other redox environments.

Extricating Manual and Non-Manual Features for Subunit Level Medical Sign Modelling in Automatic Sign Language Classification and Recognition.

PubMed

R, Elakkiya; K, Selvamani

2017-09-22

Subunit segmenting and modelling in medical sign language is one of the important studies in linguistic-oriented and vision-based Sign Language Recognition (SLR). Many efforts were made in the precedent to focus the functional subunits from the view of linguistic syllables but the problem is implementing such subunit extraction using syllables is not feasible in real-world computer vision techniques. And also, the present recognition systems are designed in such a way that it can detect the signer dependent actions under restricted and laboratory conditions. This research paper aims at solving these two important issues (1) Subunit extraction and (2) Signer independent action on visual sign language recognition. Subunit extraction involved in the sequential and parallel breakdown of sign gestures without any prior knowledge on syllables and number of subunits. A novel Bayesian Parallel Hidden Markov Model (BPaHMM) is introduced for subunit extraction to combine the features of manual and non-manual parameters to yield better results in classification and recognition of signs. Signer independent action aims in using a single web camera for different signer behaviour patterns and for cross-signer validation. Experimental results have proved that the proposed signer independent subunit level modelling for sign language classification and recognition has shown improvement and variations when compared with other existing works.

Evaluating CO2 mineralization capacity of sedimentary rock Using BCR sequential extraction procedures

NASA Astrophysics Data System (ADS)

Yang, Gang-Ting; Yu, Chi-Wen; Yang, Hsiao-Ming; Chiao, Chung-Hui; Yang, Ming-Wei

2015-04-01

To relief the high concentration of carbon dioxide in the atmosphere, carbon capture and storage (CCS) is gradually becoming an important concept to reduce greenhouse gas emissions. In IPCC Special Report on CCS, the storage mechanisms for geological formations are categorized into structural/stratigraphic, hydrodynamic and geochemical trappings. Geochemical trapping is considered as a storage mechanism, which can further increase storage capacity, effectiveness and security in terms of permanent CO2 sequestration. The injected CO2 can have geochemical interactions with pore fluid and reservoir rocks and transform into minerals. It is important to evaluate the capacity of reservoir rock for sequestrating CO2. In this study, sedimentary rock samples were collected from a 2-km-deep well in Midwestern Taiwan; and, the BCR sequential extraction experiments developed by European Union Measurement and Testing Programme were conducted. BCR was designed for extracting three major phases from soil, including exchangeable phase and carbonates (the first stage), reducible phase (the second stage) and oxidizable phase (the third stage). The chemistry of extracted solutions and rock residues were measured with ICP-MS and XRF, respectively. According to the results of XRF, considerable amounts of calcium and iron can be extracted by BCR procedures but other cations are negligible. In general, shale has a higher capacity of CO2 sequestration than sandstone. The first stage of extraction can release about 6 (sandstone) to 18.5 (shale) g of calcium from 1 kg rock, which are equivalent to 6.6 and 20.4 g CO2/kg rock, respectively. In the second stage extraction, 0.71 (sandstone) to 1.38 (shale) g/kg rock of iron can be released and can mineralized 0.56 to 1.08 g CO2/kg rock. However, there are no considerable cations extracted in the third stage of BCR as shown by the XRF analysis. In addition, the results of ICP-MS show that Mg can be released in the order of 10-3 g from 1 kg rock while cations of Zn, Co, Ni, Cd, Pb, Cu and Ba are in the order of 10-4 g.

Critical evaluation of the ability of sequential extraction procedures to quantify discrete forms of selenium in sediments and soils.

PubMed

Wright, Michael T; Parker, David R; Amrhein, Christopher

2003-10-15

Sequential extraction procedures (SEPs) have been widely used to characterize the mobility, bioavailibility, and potential toxicity of trace elements in soils and sediments. Although oft-criticized, these methods may perform best with redox-labile elements (As, Hg, Se) for which more discrete biogeochemical phases may arise from variations in oxidation number. We critically evaluated two published SEPs for Se for their specificity and precision by applying them to four discrete components in an inert silica matrix: soluble Se(VI) (selenate), Se(IV) (selenite) adsorbed onto goethite, elemental Se, and a metal selenide (FeSe; achavalite). These were extracted both individually and in a mixed model sediment. The more selective of the two procedures was modified to further improve its selectivity (SEP 2M). Both SEP 1 and SEP 2M quantitatively recovered soluble selenate but yielded incomplete recoveries of adsorbed selenite (64% and 81%, respectively). SEP 1 utilizes 0.1 M K2S2O8 to target "organically associated" Se, but this extractant also solubilized most of the elemental (64%) and iron selenide (91%) components of the model sediment. In SEP 2M, the Na2SO3 used in step III is effective in extracting elemental Se but also extracted 17% of the Se from the iron selenide, such that the elemental fraction would be overestimated should both forms coexist. Application of SEP 2M to eight wetland sediments further suggested that the Na2SO3 in step III extracts some organically associated Se, so a NaOH extraction was inserted beforehand to yield a further modification, SEP 2OH. Results using this five-step procedure suggested that the four-step SEP 2M could overestimate elemental Se by as much as 43% due to solubilization of organic Se. Although still imperfect in its selectivity, SEP 20H may be the most suitable procedure for routine, accurate fractionation of Se in soils and sediments. However, the strong oxidant (NaOCl) used in the final step cannot distinguish between refractory organic forms of Se and pyritic Se that might form under sulfur-reducing conditions.

Description and effects of sequential behavior practice in teacher education.

PubMed

Sharpe, T; Lounsbery, M; Bahls, V

1997-09-01

This study examined the effects of a sequential behavior feedback protocol on the practice-teaching experiences of undergraduate teacher trainees. The performance competencies of teacher trainees were analyzed using an alternative opportunities for appropriate action measure. Data support the added utility of sequential (Sharpe, 1997a, 1997b) behavior analysis information in systematic observation approaches to teacher education. One field-based undergraduate practicum using sequential behavior (i.e., field systems analysis) principles was monitored. Summarized are the key elements of the (a) classroom instruction provided as a precursor to the practice teaching experience, (b) practice teaching experience, and (c) field systems observation tool used for evaluation and feedback, including multiple-baseline data (N = 4) to support this approach to teacher education. Results point to (a) the strong relationship between sequential behavior feedback and the positive change in four preservice teachers' day-to-day teaching practices in challenging situational contexts, and (b) the relationship between changes in teacher practices and positive changes in the behavioral practices of gymnasium pupils. Sequential behavior feedback was also socially validated by the undergraduate participants and Professional Development School teacher supervisors in the study.

Mammalian mucosal α-glucosidases coordinate with α-amylase in the initial starch hydrolysis stage to have a role in starch digestion beyond glucogenesis.

PubMed

Dhital, Sushil; Lin, Amy Hui-Mei; Hamaker, Bruce R; Gidley, Michael J; Muniandy, Anbuhkani

2013-01-01

Starch digestion in the human body is typically viewed in a sequential manner beginning with α-amylase and followed by α-glucosidase to produce glucose. This report indicates that the two enzyme types can act synergistically to digest granular starch structure. The aim of this study was to investigate how the mucosal α-glucosidases act with α-amylase to digest granular starch. Two types of enzyme extracts, pancreatic and intestinal extracts, were applied. The pancreatic extract containing predominantly α-amylase, and intestinal extract containing a combination of α-amylase and mucosal α-glucosidase activities, were applied to three granular maize starches with different amylose contents in an in vitro system. Relative glucogenesis, released maltooligosaccharide amounts, and structural changes of degraded residues were examined. Pancreatic extract-treated starches showed a hydrolysis limit over the 12 h incubation period with residues having a higher gelatinization temperature than the native starch. α-Amylase combined with the mucosal α-glucosidases in the intestinal extract showed higher glucogenesis as expected, but also higher maltooligosaccharide amounts indicating an overall greater degree of granular starch breakdown. Starch residues after intestinal extract digestion showed more starch fragmentation, higher gelatinization temperature, higher crystallinity (without any change in polymorph), and an increase of intermediate-sized or small-sized fractions of starch molecules, but did not show preferential hydrolysis of either amylose or amylopectin. Direct digestion of granular starch by mammalian recombinant mucosal α-glucosidases was observed which shows that these enzymes may work either independently or together with α-amylase to digest starch. Thus, mucosal α-glucosidases can have a synergistic effect with α-amylase on granular starch digestion, consistent with a role in overall starch digestion beyond their primary glucogenesis function.

Mammalian Mucosal α-Glucosidases Coordinate with α-Amylase in the Initial Starch Hydrolysis Stage to Have a Role in Starch Digestion beyond Glucogenesis

PubMed Central

Dhital, Sushil; Lin, Amy Hui-Mei; Hamaker, Bruce R.; Gidley, Michael J.; Muniandy, Anbuhkani

2013-01-01

Starch digestion in the human body is typically viewed in a sequential manner beginning with α-amylase and followed by α-glucosidase to produce glucose. This report indicates that the two enzyme types can act synergistically to digest granular starch structure. The aim of this study was to investigate how the mucosal α-glucosidases act with α-amylase to digest granular starch. Two types of enzyme extracts, pancreatic and intestinal extracts, were applied. The pancreatic extract containing predominantly α-amylase, and intestinal extract containing a combination of α-amylase and mucosal α-glucosidase activities, were applied to three granular maize starches with different amylose contents in an in vitro system. Relative glucogenesis, released maltooligosaccharide amounts, and structural changes of degraded residues were examined. Pancreatic extract-treated starches showed a hydrolysis limit over the 12 h incubation period with residues having a higher gelatinization temperature than the native starch. α-Amylase combined with the mucosal α-glucosidases in the intestinal extract showed higher glucogenesis as expected, but also higher maltooligosaccharide amounts indicating an overall greater degree of granular starch breakdown. Starch residues after intestinal extract digestion showed more starch fragmentation, higher gelatinization temperature, higher crystallinity (without any change in polymorph), and an increase of intermediate-sized or small-sized fractions of starch molecules, but did not show preferential hydrolysis of either amylose or amylopectin. Direct digestion of granular starch by mammalian recombinant mucosal α-glucosidases was observed which shows that these enzymes may work either independently or together with α-amylase to digest starch. Thus, mucosal α-glucosidases can have a synergistic effect with α-amylase on granular starch digestion, consistent with a role in overall starch digestion beyond their primary glucogenesis function. PMID:23638112

Geochemical characteristics of Au in the water systemfrom abandoned gold mines area

NASA Astrophysics Data System (ADS)

Cho, Kanghee; Kim, Bongju; Kim, Byungjoo; Park, Cheonyoung; Choi, Nagchoul

2013-04-01

The AMD (acid mine drainage) poses a threat not only to the aquatic life in mountain streams and rivers, but can also contaminate groundwater and downstream water bodies. Besides pyrite, sulfides of copper, zinc, cadmium, lead and arsenic in the drainage tunnels and tailings piles also undergo similar geochemical reactions, releasing toxic metals and more H+ into the mine drainage. The fate of gold in the AMD system is reduced and precipitated with iron oxides by oxidation-reduction reaction between ferrous/ferric iron and Au3+/Au0. The objective of this study was to investigate the influence of the transport characteristic on the distance through distribution of heavy metals and gold on the interrelation between acid mine drainage and sediments in the abandoned Gwang-yang gold mine, Korea. We conducted to confirm the chemical (chemical analysis and sequential extraction) and mineralogical property (XRD, SEM-EDS and polarization microscope) from AMD, sediments and tailing samples. The result of chemical analysis showed that Fe contents in the AMD and sediments from the upstream to the downstream ranged of 10.99 to 18.60 mg/L and 478.74 to 542.98 mg/kg, respectively. Also the contents of Au and As in the sediment were respectively ranged from 14.06 to 22.85 g/t and 0.245 to 0.612 mg/kg. In XRD analysis of the sediments, x-ray diffracted d-value belong to quartz, geothite was observed. The results of SEM-EDS analysis revealed that iron hydroxide were observed in the sediment and tailing. The result of sequential extraction for Au from the sediment showed that Au predominated in 26 to 27% of Organic matter fraction(STEP 4), and 24 to 25% of Residual fraction(STEP 5).

G-sequentially connectedness for topological groups with operations

NASA Astrophysics Data System (ADS)

Mucuk, Osman; Cakalli, Huseyin

2016-08-01

It is a well-known fact that for a Hausdorff topological group X, the limits of convergent sequences in X define a function denoted by lim from the set of all convergent sequences in X to X. This notion has been modified by Connor and Grosse-Erdmann for real functions by replacing lim with an arbitrary linear functional G defined on a linear subspace of the vector space of all real sequences. Recently some authors have extended the concept to the topological group setting and introduced the concepts of G-sequential continuity, G-sequential compactness and G-sequential connectedness. In this work, we present some results about G-sequentially closures, G-sequentially connectedness and fundamental system of G-sequentially open neighbourhoods for topological group with operations which include topological groups, topological rings without identity, R-modules, Lie algebras, Jordan algebras, and many others.

Transformation of zinc-concentrate in surface and subsurface environments: Implications for assessing zinc mobility/toxicity and choosing an optimal remediation strategy.

PubMed

Kwon, Man Jae; Boyanov, Maxim I; Yang, Jung-Seok; Lee, Seunghak; Hwang, Yun Ho; Lee, Ju Yeon; Mishra, Bhoopesh; Kemner, Kenneth M

2017-07-01

Zinc contamination in near- and sub-surface environments is a serious threat to many ecosystems and to public health. Sufficient understanding of Zn speciation and transport mechanisms is therefore critical to evaluating its risk to the environment and to developing remediation strategies. The geochemical and mineralogical characteristics of contaminated soils in the vicinity of a Zn ore transportation route were thoroughly investigated using a variety of analytical techniques (sequential extraction, XRF, XRD, SEM, and XAFS). Imported Zn-concentrate (ZnS) was deposited in a receiving facility and dispersed over time to the surrounding roadside areas and rice-paddy soils. Subsequent physical and chemical weathering resulted in dispersal into the subsurface. The species identified in the contaminated areas included Zn-sulfide, Zn-carbonate, other O-coordinated Zn-minerals, and Zn species bound to Fe/Mn oxides or clays, as confirmed by XAFS spectroscopy and sequential extraction. The observed transformation from S-coordinated Zn to O-coordinated Zn associated with minerals suggests that this contaminant can change into more soluble and labile forms as a result of weathering. For the purpose of developing a soil washing remediation process, the contaminated samples were extracted with dilute acids. The extraction efficiency increased with the increase of O-coordinated Zn relative to S-coordinated Zn in the sediment. This study demonstrates that improved understanding of Zn speciation in contaminated soils is essential for well-informed decision making regarding metal mobility and toxicity, as well as for choosing an appropriate remediation strategy using soil washing. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sequential Actions of the AAA-ATPase Valosin-containing Protein (VCP)/p97 and the Proteasome 19 S Regulatory Particle in Sterol-accelerated, Endoplasmic Reticulum (ER)-associated Degradation of 3-Hydroxy-3-methylglutaryl-coenzyme A Reductase*

PubMed Central

Morris, Lindsey L.; Hartman, Isamu Z.; Jun, Dong-Jae; Seemann, Joachim; DeBose-Boyd, Russell A.

2014-01-01

Accelerated endoplasmic reticulum (ER)-associated degradation (ERAD) of the cholesterol biosynthetic enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase results from its sterol-induced binding to ER membrane proteins called Insig-1 and Insig-2. This binding allows for subsequent ubiquitination of reductase by Insig-associated ubiquitin ligases. Once ubiquitinated, reductase becomes dislocated from ER membranes into the cytosol for degradation by 26 S proteasomes through poorly defined reactions mediated by the AAA-ATPase valosin-containing protein (VCP)/p97 and augmented by the nonsterol isoprenoid geranylgeraniol. Here, we report that the oxysterol 25-hydroxycholesterol and geranylgeraniol combine to trigger extraction of reductase across ER membranes prior to its cytosolic release. This conclusion was drawn from studies utilizing a novel assay that measures membrane extraction of reductase by determining susceptibility of a lumenal epitope in the enzyme to in vitro protease digestion. Susceptibility of the lumenal epitope to protease digestion and thus membrane extraction of reductase were tightly regulated by 25-hydroxycholesterol and geranylgeraniol. The reaction was inhibited by RNA interference-mediated knockdown of either Insigs or VCP/p97. In contrast, reductase continued to become membrane-extracted, but not cytosolically dislocated, in cells deficient for AAA-ATPases of the proteasome 19 S regulatory particle. These findings establish sequential roles for VCP/p97 and the 19 S regulatory particle in the sterol-accelerated ERAD of reductase that may be applicable to the ERAD of other substrates. PMID:24860107

Transformation of zinc-concentrate in surface and subsurface environments: Implications for assessing zinc mobility/toxicity and choosing an optimal remediation strategy

DOE PAGES

Kwon, Man Jae; Boyanov, Maxim I.; Yang, Jung -Seok; ...

2017-03-24

Zinc contamination in near- and sub-surface environments is a serious threat to many ecosystems and to public health. Sufficient understanding of Zn speciation and transport mechanisms is therefore critical to evaluating its risk to the environment and to developing remediation strategies. The geochemical and mineralogical characteristics of contaminated soils in the vicinity of a Zn ore transportation route were thoroughly investigated using a variety of analytical techniques (sequential extraction, XRF, XRD, SEM, and XAFS). Imported Zn-concentrate (ZnS) was deposited in a receiving facility and dispersed over time to the surrounding roadside areas and rice-paddy soils. Subsequent physical and chemical weatheringmore » resulted in dispersal into the subsurface. The species identified in the contaminated areas included Zn-sulfide, Zn-carbonate, other O-coordinated Zn-minerals, and Zn species bound to Fe/Mn oxides or clays, as confirmed by XAFS spectroscopy and sequential extraction. The observed transformation from S-coordinated Zn to O-coordinated Zn associated with minerals suggests that this contaminant can change into more soluble and labile forms as a result of weathering. For the purpose of developing a soil washing remediation process, the contaminated samples were extracted with dilute acids. The extraction efficiency increased with the increase of O-coordinated Zn relative to S-coordinated Zn in the sediment. Furthermore, this study demonstrates that improved understanding of Zn speciation in contaminated soils is essential for well-informed decision making regarding metal mobility and toxicity, as well as for choosing an appropriate remediation strategy using soil washing.« less

Assessing Metal Mobilization from Industrially Lead ...

EPA Pesticide Factsheets

A series of leaching and partitioning tests (Toxicity Characteristic Leaching Procedure (TCLP), Synthetic Precipitation Leaching Procedure (SPLP), Controlled Acidity Leaching Protocol (CALP), Acid Neutralization Capacity (ANC), and sequential extraction) were applied to three different soils to study potential mobility of metals into groundwater. Two of these soils were lead (Pb)-contaminated soils (Hotspot 1 and Hotspot 2) collected from an urban site associated with lead smelting and other industrial operations. The third sample (Stockpile) was soil affected by previous contamination in the area, removed from residential properties, stockpiled, and selected to be used as fill material in the studied site. The TCLP and CALP showed that Pb could be released from both hotspots, but were not released in the acidic rainfall extraction fluid of the SPLP. The sequential extraction showed that Pb in the hotspot soils was associated with the carbonate fraction, while As was associated with the Fe and Mn oxides. The stockpile released traces of Pb or As in the TCLP and CALP, but the ANC only released Pb under acidic conditions and the SPLP did not release Pb or As. Overall, the projected repository with Stockpile would not pose imminent danger to groundwater because, under the expected environmental conditions, Pb and As tend to remain in the solid phase. The objectives of this study were to determine if the stockpiled soil was suitable for the intended fill purpo

Comparison of first pass bolus AIFs extracted from sequential 18F-FDG PET and DSC-MRI of mice

NASA Astrophysics Data System (ADS)

Evans, Eleanor; Sawiak, Stephen J.; Ward, Alexander O.; Buonincontri, Guido; Hawkes, Robert C.; Adrian Carpenter, T.

2014-01-01

Accurate kinetic modelling of in vivo physiological function using positron emission tomography (PET) requires determination of the tracer time-activity curve in plasma, known as the arterial input function (AIF). The AIF is usually determined by invasive blood sampling methods, which are prohibitive in murine studies due to low total blood volumes. Extracting AIFs from PET images is also challenging due to large partial volume effects (PVE). We hypothesise that in combined PET with magnetic resonance imaging (PET/MR), a co-injected bolus of MR contrast agent and PET ligand can be tracked using fast MR acquisitions. This protocol would allow extraction of a MR AIF from MR contrast agent concentration-time curves, at higher spatial and temporal resolution than an image-derived PET AIF. A conversion factor could then be applied to the MR AIF for use in PET kinetic analysis. This work has compared AIFs obtained from sequential DSC-MRI and PET with separate injections of gadolinium contrast agent and 18F-FDG respectively to ascertain the technique‧s validity. An automated voxel selection algorithm was employed to improve MR AIF reproducibility. We found that MR and PET AIFs displayed similar character in the first pass, confirmed by gamma variate fits (p<0.02). MR AIFs displayed reduced PVE compared to PET AIFs, indicating their potential use in PET/MR studies.

Comparison of first pass bolus AIFs extracted from sequential 18F-FDG PET and DSC-MRI of mice.

PubMed

Evans, Eleanor; Sawiak, Stephen J; Ward, Alexander O; Buonincontri, Guido; Hawkes, Robert C; Carpenter, T Adrian

2014-01-11

Accurate kinetic modelling of in vivo physiological function using positron emission tomography (PET) requires determination of the tracer time-activity curve in plasma, known as the arterial input function (AIF). The AIF is usually determined by invasive blood sampling methods, which are prohibitive in murine studies due to low total blood volumes. Extracting AIFs from PET images is also challenging due to large partial volume effects (PVE). We hypothesise that in combined PET with magnetic resonance imaging (PET/MR), a co-injected bolus of MR contrast agent and PET ligand can be tracked using fast MR acquisitions. This protocol would allow extraction of a MR AIF from MR contrast agent concentration-time curves, at higher spatial and temporal resolution than an image-derived PET AIF. A conversion factor could then be applied to the MR AIF for use in PET kinetic analysis. This work has compared AIFs obtained from sequential DSC-MRI and PET with separate injections of gadolinium contrast agent and 18 F-FDG respectively to ascertain the technique's validity. An automated voxel selection algorithm was employed to improve MR AIF reproducibility. We found that MR and PET AIFs displayed similar character in the first pass, confirmed by gamma variate fits (p<0.02). MR AIFs displayed reduced PVE compared to PET AIFs, indicating their potential use in PET/MR studies.

Sequential solvent extraction for the modes of occurrence of selenium in coals of different ranks from the Huaibei Coalfield, China

USGS Publications Warehouse

Zhang, Y.; Liu, Gaisheng; Chou, C.-L.; Wang, L.; Kang, Y.

2007-01-01

Forms of selenium in bituminous coal, anthracite, and cokeite (natural coke) from Huaibei Coalfield, Anhui, China, have been determined by sequential solvent extraction. The selenium content in bulk samples is 4.0, 2.4, and 2.0 ??g/g in bituminous coal, anthracite, and cokeite, respectively. The six forms of selenium determined by six-step solvent extraction are water-leachable, ion-exchangeable, organic matter-associated, carbonate-associated, silicate-associated, and sulfide-associated. The predominant forms of selenium in bituminous coal are organic matter-associated (39.0%), sulfide-associated (21.1%), and silicate bound (31.8%); these three forms account for 92% of the total. The organic matter bound-selenium decrease dramatically from bituminous coal (39.0%) to anthracite (11.6%) and to cokeite (0%), indicating that organic matter bound selenium is converted to other forms during metamorphism of the coal, most likely sulfide-form. The sulfide-associated form increased remarkably from bituminous coal (21.1%) to anthracite (50.4%) and cokeite (54.5%), indicating the formation of selenium sulfide, possibly in pyrite during the transformation of bituminous coal to anthracite and cokeite. The silicate-associated selenium in bituminous coal (31.8%) is much higher than that in anthracite (16.4%) and cokeite (15.8%), indicating that silicate-associated selenium is partly converted to sulfide during metamorphism. ?? 2007 Zhang et al; licensee BioMed Central Ltd.

Sequential Extractions and Toxicity Potential of Trace Metals Absorbed into Airborne Particles in an Urban Atmosphere of Southwestern Nigeria

PubMed Central

Ediagbonya, Thompson Faraday

2018-01-01

The paper investigates the hypothesis that biotoxicities of trace metals depend not only on the concentration as expressed by the total amount, but also on their geochemical fractions and bioavailability. Airborne particles were collected using SKC Air Check XR 5000 high volume Sampler at a human breathing height of 1.5–2.0 meters, during the dry season months from November 2014 to March 2015 at different locations in Akure (7°10′N and 5°15′E). The geochemical-based sequential extractions were performed on the particles using a series of increasingly stringent solutions selected to extract metals (Cd, Cu, Cr, Ni, Pb, Zn, and Mn) into four operational geochemical phases—exchangeable, reducible, organic, and residual—and then quantified using an Atomic Absorption Spectrophotometer. The results showed metals concentration of order Pb > Cr > Cd > Zn > Ni > Cu > Mn. However, most metals in the samples exist in nonmobile fractions: exchangeable (6.43–16.2%), reducible (32.58–47.39%), organic (4.73–9.88%), and residual (18.28–27.53%). The pollution indices show ingestion as the leading route of metal exposure, with noncarcinogenic (HQ) and cancer risk (HI) for humans in the area being higher than 1.0 × 10−4, indicating a health threat. PMID:29686588

Cranberry versus placebo in the prevention of urinary infections in multiple sclerosis: a multicenter, randomized, placebo-controlled, double-blind trial.

PubMed

Gallien, Philippe; Amarenco, Gérard; Benoit, Nicolas; Bonniaud, Véronique; Donzé, Cécile; Kerdraon, Jacques; de Seze, Marianne; Denys, Pierre; Renault, Alain; Naudet, Florian; Reymann, Jean Michel

2014-08-01

Our aim was to assess the usefulness of cranberry extract in multiple sclerosis (MS) patients suffering from urinary disorders. In total, 171 adult MS outpatients with urinary disorders presenting at eight centers were randomized (stratification according to center and use of clean intermittent self-catheterization) to cranberry versus placebo in a 1-year, prospective, double-blind study that was analyzed using a sequential method on an intent-to-treat basis. An independent monitoring board analyzed the results of the analyses each time 40 patients were assessed on the main endpoint. Cranberry extract (36 mg proanthocyanidins per day) or a matching placebo was taken by participants twice daily for 1 year. The primary endpoint was the time to first symptomatic urinary tract infection (UTI), subject to validation by a validation committee. The second sequential analyses allowed us to accept the null hypothesis (no difference between cranberry and placebo). There was no difference in time to first symptomatic UTI distribution across 1 year, with an estimated hazard ratio of 0.99, 95% CI [0.61, 1.60] (p = 0.97). Secondary endpoints and tolerance did not differ between groups. Taking cranberry extract versus placebo twice a day did not prevent UTI occurrence in MS patients with urinary disorders. Trial Registration NCT00280592. © The Author(s) 2014.

Thermal, emulsifying and rheological properties of polysaccharides sequentially extracted from Vaccinium bracteatum Thunb leaves.

PubMed

Xu, Qi-Xin; Shi, Jun-Jun; Zhang, Jian-Guo; Li, Ling; Jiang, Li; Wei, Zhao-Jun

2016-12-01

Plant polysaccharides are widely used in food industry as thickening and gelling agents and these attributes largely depend on their thermal, emulsifying and rheological properties. As known, the extraction methods always bring about the diversification of property and functions of polysaccharides. Thus, the Vaccinium bracteatum Thunb leaves polysaccharides (VBTLP) were sequentially extracted using hot buffer (HBSS), chelating agent (CHSS), dilute alkaline (DASS) and concentrated alkaline (CASS). The thermal, emulsifying and rheological properties of VBTLP were investigated in the present study. Within the range of 20-225°C, CHSS showed the highest peak temperature, whereas HBSS displayed the highest endothermic enthalpy and highest emulsifying activity, while, CASS showed the longest emulsifying stability. The VBTLP solutions exhibited non-Newtonian shear-thinning behavior within the concentrations of 0.6-2.5%. The apparent viscosity of VBTLP solution decreased under following conditions: acidic pH (4.0), alkaline pH (10.0), in the presence of Ca 2+ and at high temperature, while it increased in the presence of Na + and at freezing conditions. The modulus G' and G″ of VBTLP solutions were increased with increasing oscillation frequency, and the crossover frequency shifted to lower values when the polysaccharide content increased. The above results of thermal, emulsifying and rheological properties of VBTLPs supplied the basis for V. bracteatum leaves in potential industrial applications of foods. Copyright © 2016 Elsevier B.V. All rights reserved.

Environmental Risk Implications of Metals in Sludges from Waste Water Treatment Plants: The Discovery of Vast Stores of Metal-Containing Nanoparticles.

PubMed

Tou, Feiyun; Yang, Yi; Feng, Jingnan; Niu, Zuoshun; Pan, Hui; Qin, Yukun; Guo, Xingpan; Meng, Xiangzhou; Liu, Min; Hochella, Michael F

2017-05-02

Nanoparticle (NP) assessment in sludge materials, although of growing importance in eco- and biotoxicity studies, is commonly overlooked and, at best, understudied. In the present study, sewage sludge samples from across the mega-city of Shanghai, China were investigated for the first time using a sequential extraction method coupled with single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) to quantify the abundance of metal-containing NPs in the extraction fractions and transmission electron microscopy to specifically identify the nanophases present. In general, most sludges observed showed high concentrations of Cr, Cu, Cd, Ni, Zn, and Pb, exceeding the maximum permitted values in the national application standard of acid soil in China. NPs in these sludges contribute little to the volume and mass but account for about half of the total particle number. Based on electron microscopy techniques, various NPs were further identified, including Ti-, Fe-, Zn-, Sn-, and Pb-containing NPs. All NPs, ignored by traditional metal risk evaluation methods, were observed at a concentration of 10 7 -10 11 particles/g within the bioavailable fraction of metals. These results indicate the underestimate or misestimation in evaluating the environmental risks of metals based on traditional sequential extraction methods. A new approach for the environmental risk assessment of metals, including NPs, is urgently needed.

The role of chemometrics in single and sequential extraction assays: a review. Part II. Cluster analysis, multiple linear regression, mixture resolution, experimental design and other techniques.

PubMed

Giacomino, Agnese; Abollino, Ornella; Malandrino, Mery; Mentasti, Edoardo

2011-03-04

Single and sequential extraction procedures are used for studying element mobility and availability in solid matrices, like soils, sediments, sludge, and airborne particulate matter. In the first part of this review we reported an overview on these procedures and described the applications of chemometric uni- and bivariate techniques and of multivariate pattern recognition techniques based on variable reduction to the experimental results obtained. The second part of the review deals with the use of chemometrics not only for the visualization and interpretation of data, but also for the investigation of the effects of experimental conditions on the response, the optimization of their values and the calculation of element fractionation. We will describe the principles of the multivariate chemometric techniques considered, the aims for which they were applied and the key findings obtained. The following topics will be critically addressed: pattern recognition by cluster analysis (CA), linear discriminant analysis (LDA) and other less common techniques; modelling by multiple linear regression (MLR); investigation of spatial distribution of variables by geostatistics; calculation of fractionation patterns by a mixture resolution method (Chemometric Identification of Substrates and Element Distributions, CISED); optimization and characterization of extraction procedures by experimental design; other multivariate techniques less commonly applied. Copyright © 2010 Elsevier B.V. All rights reserved.

Structural characterization of alkali-soluble polysaccharides from Panax ginseng C. A. Meyer

PubMed Central

Ji, Li; Jie, Zhenjing; Ying, Xin; Yue, Qi; Zhou, Yifa

2018-01-01

Panax ginseng C. A. Meyer (ginseng) has been widely used as a herb and functional food in the world. Polysaccharides are the main active components of ginseng. In this paper, the polysaccharides were sequentially extracted by 50 mM Na2CO3, 1 M KOH and 4 M KOH from ginseng roots treated sequentially with hot water, α-amylase and ethylenediaminetetraacetic acid extraction. Na2CO3-soluble ginseng polysaccharide (NGP) was fractionated into one neutral and three acidic fractions by anion exchange and gel permeation chromatography. Fourier transform infrared, NMR and methylation analysis indicated acidic fractions in NGP were highly branched rhamnogalacturonan-I domains, with  → 4)-α-GalpA-(1 → 2)-α-Rhap-(1 → disaccharide repeating units as backbone and β-1,4-galactan, α-1,5/1,3,5-arabinan and type II arabinogalactan as side chains. 1-KGP (1 M KOH-soluble ginseng polysaccharide) and 4-KGP (4 M KOH-soluble ginseng polysaccharide) were mainly composed of hemicellulose besides starch-like polysaccharides and minor pectin. Antibody detection, enzymic hydrolysis, high performance anion exchange chromatography and methylation analysis demonstrated xylan was the major component in 1-KGP, while xyloglucan was predominant in 4-KGP. Comparing the polysaccharides obtained by different solvent extractions, we have a comprehensive understanding about total ginseng polysaccharides. PMID:29657770

Direct comparison of XAFS spectroscopy and sequential extraction for arsenic speciation in coal

USGS Publications Warehouse

Huggins, Frank E.; Huffman, G.P.; Kolker, A.; Mroczkowski, S.; Palmer, C.A.; Finkelman, R.B.

2000-01-01

The speciation of arsenic in an Ohio bituminous coal and a North Dakota lignite has been examined by the complementary methods of arsenic XAFS spectroscopy and sequential extraction by aqueous solutions of ammonium acetate, HCl, HF, and HNO3. In order to facilitate a more direct comparison of the two methods, the arsenic XAFS spectra were obtained from aliquots of the coal prepared after each stage of the leaching procedure. For the aliquots, approximately linear correlations (r2 > 0.98 for the Ohio coal, > 0.90 for the ND lignite) were observed between the height of the edge-step in the XAFS analysis and the concentration of arsenic measured by instrumental neutron activation analysis. Results from the leaching sequence indicate that there are two major arsenic forms present in both coals; one is removed by leaching with HCl and the other by HNO3. Whereas the XAFS spectral signatures of the arsenic leached by HCl are compatible with arsenate for both coals, the arsenic leached by HNO3 is identified as arsenic associated with pyrite for the Ohio coal and as an As3+ species for the North Dakota lignite. Minor arsenate forms persist in both coals after the final leaching with nitric acid. The arsenate forms extracted in HCl are believed to be oxidation products derived from the other major arsenic forms upon exposure of the pulverized coals to air.

Automated Desalting Apparatus

NASA Technical Reports Server (NTRS)

Spencer, Maegan K.; Liu, De-Ling; Kanik, Isik; Beegle, Luther

2010-01-01

Because salt and metals can mask the signature of a variety of organic molecules (like amino acids) in any given sample, an automated system to purify complex field samples has been created for the analytical techniques of electrospray ionization/ mass spectroscopy (ESI/MS), capillary electrophoresis (CE), and biological assays where unique identification requires at least some processing of complex samples. This development allows for automated sample preparation in the laboratory and analysis of complex samples in the field with multiple types of analytical instruments. Rather than using tedious, exacting protocols for desalting samples by hand, this innovation, called the Automated Sample Processing System (ASPS), takes analytes that have been extracted through high-temperature solvent extraction and introduces them into the desalting column. After 20 minutes, the eluent is produced. This clear liquid can then be directly analyzed by the techniques listed above. The current apparatus including the computer and power supplies is sturdy, has an approximate mass of 10 kg, and a volume of about 20 20 20 cm, and is undergoing further miniaturization. This system currently targets amino acids. For these molecules, a slurry of 1 g cation exchange resin in deionized water is packed into a column of the apparatus. Initial generation of the resin is done by flowing sequentially 2.3 bed volumes of 2N NaOH and 2N HCl (1 mL each) to rinse the resin, followed by .5 mL of deionized water. This makes the pH of the resin near neutral, and eliminates cross sample contamination. Afterward, 2.3 mL of extracted sample is then loaded into the column onto the top of the resin bed. Because the column is packed tightly, the sample can be applied without disturbing the resin bed. This is a vital step needed to ensure that the analytes adhere to the resin. After the sample is drained, oxalic acid (1 mL, pH 1.6-1.8, adjusted with NH4OH) is pumped into the column. Oxalic acid works as a chelating reagent to bring out metal ions, such as calcium and iron, which would otherwise interfere with amino acid analysis. After oxalic acid, 1 mL 0.01 N HCl and 1 mL deionized water is used to sequentially rinse the resin. Finally, the amino acids attached to the resin, and the analytes are eluted using 2.5 M NH4OH (1 mL), and the NH4OH eluent is collected in a vial for analysis.

Comparison of supercritical fluid and Soxhlet extractions for the quantification of hydrocarbons from Euphorbia macroclada.

PubMed

Ozcan, Adnan; Ozcan, Asiye Safa

2004-10-08

This study compares conventional Soxhlet extraction and analytical scale supercritical fluid extraction (SFE) for their yields in extracting of hydrocarbons from arid-land plant Euphorbia macroclada. The plant material was firstly sequentially extracted with supercritical carbon dioxide, modified with 10% methanol (v/v) in the optimum conditions that is a pressure of 400atm and a temperature of 50 degrees C and then it was sonicated in methylene chloride for an additional 4h. E. macroclada was secondly extracted by using a Soxhlet apparatus at 30 degrees C for 8h in methylene chloride. The validated SFE was then compared to the extraction yield of E. macroclada with a Soxhlet extraction by using the Student's t-test at the 95% confidence level. All of extracts were fractionated with silica-gel in a glass column to get better hydrocarbon yields. Thus, the highest hydrocarbons yield from E. macroclada was achieved with SFE (5.8%) when it compared with Soxhlet extractions (1.1%). Gas chromatography (GC) analysis was performed to determine the quantitative hydrocarbons from plant material. The greatest quantitative hydrocarbon recovery from GC was obtained by supercritical carbon dioxide extract (0.6mgg(-1)).

Predicting human activities in sequences of actions in RGB-D videos

NASA Astrophysics Data System (ADS)

Jardim, David; Nunes, Luís.; Dias, Miguel

2017-03-01

In our daily activities we perform prediction or anticipation when interacting with other humans or with objects. Prediction of human activity made by computers has several potential applications: surveillance systems, human computer interfaces, sports video analysis, human-robot-collaboration, games and health-care. We propose a system capable of recognizing and predicting human actions using supervised classifiers trained with automatically labeled data evaluated in our human activity RGB-D dataset (recorded with a Kinect sensor) and using only the position of the main skeleton joints to extract features. Using conditional random fields (CRFs) to model the sequential nature of actions in a sequence has been used before, but where other approaches try to predict an outcome or anticipate ahead in time (seconds), we try to predict what will be the next action of a subject. Our results show an activity prediction accuracy of 89.9% using an automatically labeled dataset.

Auto-Tandem Catalysis in Ionic Liquids: Synthesis of 2-Oxazolidinones by Palladium-Catalyzed Oxidative Carbonylation of Propargylic Amines in EmimEtSO₄.

PubMed

Mancuso, Raffaella; Maner, Asif; Ziccarelli, Ida; Pomelli, Christian; Chiappe, Cinzia; Della Ca', Nicola; Veltri, Lucia; Gabriele, Bartolo

2016-07-08

A convenient carbonylative approach to 2-oxazolidinone derivatives carried out using an ionic liquid (1-ethyl-3-methylimidazolium ethyl sulfate, EmimEtSO₄) as the solvent is presented. It is based on the sequential concatenation of two catalytic cycles, both catalyzed by the same metal species (auto-tandem catalysis): the first cycle corresponds to the oxidative monoaminocarbonylation of the triple bond of propargylic amines to give the corresponding 2-ynamide intermediates, while the second one involves the cyclocarbonylation of the latter to yield 2-(2-oxooxazolidin-5-ylidene)-acetamides. Reactions are carried out using a simple catalytic system consisting of PdI₂ in conjunction with an excess of KI, and the catalyst/solvent system could be recycled several times without appreciable loss of activity after extraction of the organic product with Et₂O.

Effects of ammonium on uranium partitioning and kaolinite mineral dissolution.

PubMed

Emerson, Hilary P; Di Pietro, Silvina; Katsenovich, Yelena; Szecsody, Jim

2017-02-01

Ammonia gas injection is a promising technique for the remediation of uranium within the vadose zone. It can be used to manipulate the pH of a system and cause co-precipitation processes that are expected to remove uranium from the aqueous phase and decrease leaching from the solid phase. The work presented in this paper explores the effects of ammonium and sodium hydroxide on the partitioning of uranium and dissolution of the kaolinite mineral in simplified synthetic groundwaters using equilibrium batch sorption and sequential extraction experiments. It shows that there is a significant increase in uranium removal in systems with divalent cations present in the aqueous phase but not in sodium chloride synthetic groundwaters. Further, the initial conditions of the aqueous phase do not affect the dissolution of kaolinite. However, the type of base treatment does have an effect on mineral dissolution. Published by Elsevier Ltd.

Comparison of the bioavailability of elemental waste laden soils using in vivo and in vitro analytical methodology and refinement of exposure/dose models. 1998 annual progress report

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

Lioy, P.J.; Gallo, M.; Georgopoulos, P.

1998-06-01

'The authors hypotheses are: (1) the more closely the synthetic, in vitro, extractant mimics the extraction properties of the human digestive bio-fluids, the more accurate will be the estimate of an internal dose; (2) performance can be evaluated by in vivo studies with a rat model and quantitative examination of a mass balance, calculation and dose estimates from model simulations for the in vitro and in vivo system; and (3) the concentration of the elements Pb, Cd, Cr and selected Radionuclides present in the bioavailable fraction obtained with a synthetic extraction system will be a better indicator of contaminant ingestionmore » from a contaminated soil because it represents the portion of the mass which can yield exposure, uptake and then the internal dose to an individual. As of April 15, 1998, they have made significant progress in the development of a unified approach to the examination of bioavailability and bioaccessibility of elemental contamination of soils for the ingestion route of exposure. This includes the initial characterization of the soil, in vitro measurements of bioaccessibility, and in vivo measurements of bioavailability. They have identified the basic chemical and microbiological characteristics of waste laden soils. These have been used to prioritize the soils for potential mobility of the trace elements present in the soil. Subsequently they have employed a mass balance technique, which for the first time tracked the movement and distribution of elements through an in vitro or in vivo experimental protocol to define the bioaccessible and the bioavailable fractions of digested soil. The basic mass balance equation for the in vitro system is: MT = MSGJ + MIJ + MR. where MT is the total mass extractable by a specific method, MSGJ, is the mass extracted by the saliva and the gastric juices, MIJ is the mass extracted by the intestinal fluid, and MR is the unextractable portion of the initial mass. The above is based upon the use of a synthetic digestive bio-fluids model that includes the saliva, gastric juices, and intestinal fluids. The system has been devised to sequentially extract elements from soil by starting with an extraction by the saliva and carrying the entire mixture to the subsequent bio-fluids for further extraction. The residence time of the soil in each extractant and the liquid to mass ratio in the gastric juices are based upon typical values known for the human digestive system. Experiments were conducted to examine the sensitivity of the extractions to changes in these major variables. The results indicated the lack of significant extraction after 2 h of residence in gastric fluid. The range of variation of the liquid to mass ratio was element dependent over the interval 100:1 and 5,000:1. The final values used for the extraction protocol were: 2 h residence time , and a ratio of 1,000:1. Details of the chemical composition of the extraction protocol are found in Hamel, 1998.'« less

Extractability and Bioavailability of Pb and As in Historically Contaminated Orchard Soil: Effects of Compost Amendments

PubMed Central

Fleming, Margaret; Yiping, Tai; Ping, Zhuang; McBride, Murray B.

2015-01-01

The availability of Pb and As in an historically contaminated orchard soil, after amendment with compost and aging in the field, was determined by single-step chemical extraction with 1.0 M ammonium acetate at pH 4.8, sequential extraction using the modified BCR test, and a redworm bioassay in the laboratory. The efficiency of soil Pb extraction by ammonium acetate was greater at higher total soil Pb but was reduced by compost amendment. Conversely, the extraction efficiency of total soil As increased with compost amendment, but was not sensitive to total soil As. The redworm bioassay indicated Pb (but not As) bioavailability to be reduced by soil amendment with compost, a result consistent with the ammonium acetate extraction test but not reflected in modified BCR test. Electron microprobe studies of the orchard soil revealed Pb and As to be spatially associated in discrete particles along with phosphorus and iron. PMID:23474982

Chemical studies on the polysaccharides of Salicornia brachiata.

PubMed

Sanandiya, Naresh D; Siddhanta, A K

2014-11-04

A group of 12 polysaccharide extracts were prepared from the tips, stem and roots of an Indian halophyte Salicornia brachiata Roxb. obtained by sequential extractions with cold water (CW), hot water (HW), aqueous ammonium oxalate (OX) and aqueous sodium hydroxide (ALK) solutions. Monosaccharide composition analysis revealed that all the polysaccharide extract samples consisted primarily of rhamnose, arabinose, mannose, galactose, glucose, whereas ribose and xylose were present only in some of the extracts. All the extracts exhibited low apparent viscosity (1.47-2.02 cP) and sulphate and contained no prominent toxic metal ions. Fucose was detected only in OX extract of the roots. These polysaccharides were found to be heterogeneous and highly branched (glycoside linkage analysis, size-exclusion chromatography, (13)C-NMR, FT-IR, circular dichroism and optical rotation data). Physico-chemical analyses of these polysaccharides including uronic acid, sulphate and protein contents were also carried out. This constitutes the first report on the profiling of Salicornia polysaccharides. Copyright © 2014 Elsevier Ltd. All rights reserved.

Occurrence and abundance of carbohydrates and amino compounds in sequentially extracted labile soil organic matter fractions.

USDA-ARS?s Scientific Manuscript database

This study aimed to investigate the content of carbohydrates and amino compounds in three labile fraction of soil organic matter (SOM). Soil samples were collected from two agricultural fields in southern Italy and the light fraction (LF), the 500–53-µm particulate organic matter (POM) and the mobil...

Allergenicity of Peanut Proteins is Retained Following Enzymatic Hydrolysis

USDA-ARS?s Scientific Manuscript database

Rationale: Hydrolysis of peanut proteins by food-grade enzymes may reduce allergenicity and could lead to safer forms of immunotherapy. Methods: Light roasted peanut flour extracts were digested with pepsin (37°C, pH 2), Alcalase (60°C pH 8), or Flavourzyme (50°C, pH 7) up to 1 hr, or sequentially w...

Sequential deconvolution from wave-front sensing using bivariate simplex splines

NASA Astrophysics Data System (ADS)

Guo, Shiping; Zhang, Rongzhi; Li, Jisheng; Zou, Jianhua; Xu, Rong; Liu, Changhai

2015-05-01

Deconvolution from wave-front sensing (DWFS) is an imaging compensation technique for turbulence degraded images based on simultaneous recording of short exposure images and wave-front sensor data. This paper employs the multivariate splines method for the sequential DWFS: a bivariate simplex splines based average slopes measurement model is built firstly for Shack-Hartmann wave-front sensor; next, a well-conditioned least squares estimator for the spline coefficients is constructed using multiple Shack-Hartmann measurements; then, the distorted wave-front is uniquely determined by the estimated spline coefficients; the object image is finally obtained by non-blind deconvolution processing. Simulated experiments in different turbulence strength show that our method performs superior image restoration results and noise rejection capability especially when extracting the multidirectional phase derivatives.

Sequential delivery of TAT-HSP27 and VEGF using microsphere/hydrogel hybrid systems for therapeutic angiogenesis.

PubMed

Shin, Seung-Hwa; Lee, Jangwook; Lim, Kwang Suk; Rhim, Taiyoun; Lee, Sang Kyung; Kim, Yong-Hee; Lee, Kuen Yong

2013-02-28

Ischemic disease is associated with high mortality and morbidity rates, and therapeutic angiogenesis via systemic or local delivery of protein drugs is one potential approach to treat the disease. In this study, we hypothesized that combined delivery of TAT-HSP27 (HSP27 fused with transcriptional activator) and VEGF could enhance the therapeutic efficacy in an ischemic mouse model, and that sequential release could be critical in therapeutic angiogenesis. Alginate hydrogels containing TAT-HSP27 as an anti-apoptotic agent were prepared, and porous PLGA microspheres loaded with VEGF as an angiogenic agent were incorporated into the hydrogels to prepare microsphere/hydrogel hybrid delivery systems. Sequential in vitro release of TAT-HSP27 and VEGF was achieved by the hybrid systems. TAT-HSP27 was depleted from alginate gels in 7 days, while VEGF was continually released for 28 days. The release rate of VEGF was attenuated by varying the porous structures of PLGA microspheres. Sequential delivery of TAT-HSP27 and VEGF was critical to protect against muscle degeneration and fibrosis, as well as to promote new blood vessel formation in the ischemic site of a mouse model. This approach to controlling the sequential release behaviors of multiple drugs could be useful in the design of novel drug delivery systems for therapeutic angiogenesis. Copyright © 2012 Elsevier B.V. All rights reserved.

Applications of microencapsulated Bifidobacterium longum with Eleutherine americana in fresh milk tofu and pineapple juice.

PubMed

Phoem, Atchara N; Chanthachum, Suphitchaya; Voravuthikunchai, Supayang P

2015-04-03

Bifidobacterium longum was microencapsulated by extrusion technique and added in fresh milk tofu and pineapple juice. Microencapsulation of B. longum with Eleutherine americana extract, oligosaccharides extract, and commercial fructo-oligosaccharides was assessed for the bacterial survival after sequential exposure to simulated gastric and intestinal juices, and refrigeration storage. Microencapsulated B. longum with the extract and oligosaccharides extract in the food products showed better survival than free cells under adverse conditions. Sensory analysis demonstrated that the products containing co-encapsulated bacterial cells were more acceptable by consumers than free cells. Pineapple juice prepared with co-encapsulated cells had lower values for over acidification, compared with the juice with free cells added. This work suggested that microencapsulated B. longum with E. americana could enhance functional properties of fresh milk tofu and pineapple juice.

Method for contour extraction for object representation

DOEpatents

Skourikhine, Alexei N.; Prasad, Lakshman

2005-08-30

Contours are extracted for representing a pixelated object in a background pixel field. An object pixel is located that is the start of a new contour for the object and identifying that pixel as the first pixel of the new contour. A first contour point is then located on the mid-point of a transition edge of the first pixel. A tracing direction from the first contour point is determined for tracing the new contour. Contour points on mid-points of pixel transition edges are sequentially located along the tracing direction until the first contour point is again encountered to complete tracing the new contour. The new contour is then added to a list of extracted contours that represent the object. The contour extraction process associates regions and contours by labeling all the contours belonging to the same object with the same label.

Applications of Microencapsulated Bifidobacterium Longum with Eleutherine Americana in Fresh Milk Tofu and Pineapple Juice

PubMed Central

Phoem, Atchara N.; Chanthachum, Suphitchaya; Voravuthikunchai, Supayang P.

2015-01-01

Bifidobacterium longum was microencapsulated by extrusion technique and added in fresh milk tofu and pineapple juice. Microencapsulation of B. longum with Eleutherine americana extract, oligosaccharides extract, and commercial fructo-oligosaccharides was assessed for the bacterial survival after sequential exposure to simulated gastric and intestinal juices, and refrigeration storage. Microencapsulated B. longum with the extract and oligosaccharides extract in the food products showed better survival than free cells under adverse conditions. Sensory analysis demonstrated that the products containing co-encapsulated bacterial cells were more acceptable by consumers than free cells. Pineapple juice prepared with co-encapsulated cells had lower values for over acidification, compared with the juice with free cells added. This work suggested that microencapsulated B. longum with E. americana could enhance functional properties of fresh milk tofu and pineapple juice. PMID:25854832

A hybrid monolithic column based on boronate-functionalized graphene oxide nanosheets for online specific enrichment of glycoproteins.

PubMed

Zhou, Chanyuan; Chen, Xiaoman; Du, Zhuo; Li, Gongke; Xiao, Xiaohua; Cai, Zongwei

2017-05-19

A hybrid monolithic column based on aminophenylboronic acid (APBA)-functionalized graphene oxide (GO) has been developed and used for selective enrichment of glycoproteins. The APBA/GO composites were homogeneously incorporated into a polymer monolithic column with the help of oligomer matrix and followed by in situ polymerization. The effect of dispersion of APBA/GO composites in the polymerization mixture on the performance of the monolithic column was explored in detail. The presence of graphene oxide not only enlarged the BET surface area from 6.3m 2 /g to 169.4m 2 /g, but also provided abundant boronic acid moieties for glycoprotein extraction, which improved the enrichment selectivity and efficiency for glycoproteins. The APBA/GO hybrid monolithic column was incorporated into a sequential injection system, which facilitated online extraction of proteins. Combining the superior properties of extraordinary surface area of GO and the affinity interaction of APBA to glycoproteins, the APBA/GO hybrid monolithic column showed higher enrichment factors for glycoproteins than other proteins without cis-diol-containing groups. Also, under comparable or even shorter processing time and without the addition of any organic solvent, it showed higher binding capacity toward glycoproteins compared with the conventional boronate affinity monolithic column. The practical applicability of this system was demonstrated by processing of egg white samples for extraction of ovalbumin and ovotransferrin, and satisfactory results were obtained by assay with SDS-PAGE. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of TDRSS-user orbit determination accuracy using batch least-squares and sequential methods

NASA Technical Reports Server (NTRS)

Oza, D. H.; Jones, T. L.; Hodjatzadeh, M.; Samii, M. V.; Doll, C. E.; Hart, R. C.; Mistretta, G. D.

1991-01-01

The development of the Real-Time Orbit Determination/Enhanced (RTOD/E) system as a prototype system for sequential orbit determination on a Disk Operating System (DOS) based Personal Computer (PC) is addressed. The results of a study to compare the orbit determination accuracy of a Tracking and Data Relay Satellite System (TDRSS) user spacecraft obtained using RTOD/E with the accuracy of an established batch least squares system, the Goddard Trajectory Determination System (GTDS), is addressed. Independent assessments were made to examine the consistencies of results obtained by the batch and sequential methods. Comparisons were made between the forward filtered RTOD/E orbit solutions and definitive GTDS orbit solutions for the Earth Radiation Budget Satellite (ERBS); the maximum solution differences were less than 25 m after the filter had reached steady state.

Geochemical partitioning of Cu and Ni in mangrove sediments: relationships with their bioavailability.

PubMed

Chakraborty, Parthasarathi; Ramteke, Darwin; Chakraborty, Sucharita

2015-04-15

Sequential extraction study was performed to determine the concentrations of non-residual metal-complexes in the mangrove sediments from the Divar Island, (west coast of India). Accumulation of metal in the mangrove roots (from the same location) was determined and used as an indicator of bioavailability of metal. An attempt was made to establish a mechanistic linkage between the non-residual metal complexes and their bioavailability in the mangrove system. The non-residual fractions of Cu and Ni were mainly associated with Fe/Mn oxyhydroxide and organic phases in the sediments. A part of these metal fractions were bioavailable in the system. These two phases were the major controlling factors for Ni speciation and their bioavailability in the studied sediments. However, Cu was found to interact more strongly with the organic phases than Ni in the mangrove sediments. Organic phases in the mangrove sediments acted as buffer to control the speciation and bioavailability of Cu in the system. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mise en Scene: Conversion of Scenarios to CSP Traces for the Requirements-to-Design-to-Code Project

NASA Technical Reports Server (NTRS)

Carter. John D.; Gardner, William B.; Rash, James L.; Hinchey, Michael G.

2007-01-01

The "Requirements-to-Design-to-Code" (R2D2C) project at NASA's Goddard Space Flight Center is based on deriving a formal specification expressed in Communicating Sequential Processes (CSP) notation from system requirements supplied in the form of CSP traces. The traces, in turn, are to be extracted from scenarios, a user-friendly medium often used to describe the required behavior of computer systems under development. This work, called Mise en Scene, defines a new scenario medium (Scenario Notation Language, SNL) suitable for control-dominated systems, coupled with a two-stage process for automatic translation of scenarios to a new trace medium (Trace Notation Language, TNL) that encompasses CSP traces. Mise en Scene is offered as an initial solution to the problem of the scenarios-to-traces "D2" phase of R2D2C. A survey of the "scenario" concept and some case studies are also provided.

Flotation as a remediation technique for heavily polluted dredged material. 2. Characterisation of flotated fractions.

PubMed

Cauwenberg, P; Verdonckt, F; Maes, A

1998-01-19

The particle size distribution and the metal speciation of the heavy metals were investigated on dredged sediment and on the fractions obtained by mechanical agitated (Denver) flotation. The transition metal ions (cadmium, copper, lead and zinc) were flotated specifically independent of the particle size. Particle size analysis, EDTA extraction and sequential extracts indicated that during flotation a redistribution of metals occurred due to the oxidation of metal sulphides. This oxidation process was more pronounced when the flotation was performed at higher pH values and resulted in a decrease in flotation specificity.

Fractionation of metals by sequential extraction procedures (BCR and Tessier) in soil exposed to fire of wide temperature range

NASA Astrophysics Data System (ADS)

Fajkovic, Hana; Rončević, Sanda; Nemet, Ivan; Prohić, Esad; Leontić-Vazdar, Dana

2017-04-01

Forest fire presents serious problem, especially in Mediterranean Region. Effects of fire are numerous, from climate change and deforestation to loss of soil organic matter and changes in soil properties. One of the effects, not well documented, is possible redistribution and/or remobilisation of pollutants previously deposited in the soil, due to the new physical and chemical soil properties and changes in equilibrium conditions. For understanding and predicting possible redistribution and/or remobilisation of potential pollutants from soil, affected by fire different in temperature, several laboratory investigations were carried out. To evaluate the influence of organic matter on soil under fire, three soil samples were analysed and compared: (a) the one with added coniferous organic matter; (b) deciduous organic matter (b) and (c) soil without additional organic matter. Type of organic matter is closely related to pH of soil, as pH is influencing the mobility of some pollutants, e.g. metals. For that reason pH was also measured through all experimental steps. Each of mentioned soil samples (a, b and c) were heated at 1+3 different temperatures (25°C, 200°C, 500°C and 850°C). After heating, whereby fire effect on soil was simulated, samples were analysed by BCR protocol with the addition of a first step of sequential extraction procedure by Tessier and analysis of residual by aqua regia. Element fractionation of heavy metals by this procedure was used to determine the amounts of selected elements (Al, Cd, Cr, Co, Cu, Fe, Mn, Ni, Pb and Zn). Selected metal concentrations were determined using inductively coupled plasma atomic emission spectrometer. Further on, loss of organic matter was calculated after each heating procedure as well as the mineral composition. The mineral composition was determined using an X-ray diffraction. From obtained results, it can be concluded that temperature has an influence on concentration of elements in specific step of sequential extraction procedures. The first step of Tessier and BCR extraction of samples heated at 250°C and 500°C showed increasing trend of elemental concentrations. Results of these steps are especially important since they indicate mobile fraction of the elements (exchangeable, water- and acid-soluble fraction), which can easily affect the environment. Extraction procedures of samples combusted at 850°C showed that decrease in measured elemental content occurred. Some correlation is also noticed between type of organic matter, pH and concentration of analysed elements.

Mining patterns in persistent surveillance systems with smart query and visual analytics

NASA Astrophysics Data System (ADS)

Habibi, Mohammad S.; Shirkhodaie, Amir

2013-05-01

In Persistent Surveillance Systems (PSS) the ability to detect and characterize events geospatially help take pre-emptive steps to counter adversary's actions. Interactive Visual Analytic (VA) model offers this platform for pattern investigation and reasoning to comprehend and/or predict such occurrences. The need for identifying and offsetting these threats requires collecting information from diverse sources, which brings with it increasingly abstract data. These abstract semantic data have a degree of inherent uncertainty and imprecision, and require a method for their filtration before being processed further. In this paper, we have introduced an approach based on Vector Space Modeling (VSM) technique for classification of spatiotemporal sequential patterns of group activities. The feature vectors consist of an array of attributes extracted from generated sensors semantic annotated messages. To facilitate proper similarity matching and detection of time-varying spatiotemporal patterns, a Temporal-Dynamic Time Warping (DTW) method with Gaussian Mixture Model (GMM) for Expectation Maximization (EM) is introduced. DTW is intended for detection of event patterns from neighborhood-proximity semantic frames derived from established ontology. GMM with EM, on the other hand, is employed as a Bayesian probabilistic model to estimated probability of events associated with a detected spatiotemporal pattern. In this paper, we present a new visual analytic tool for testing and evaluation group activities detected under this control scheme. Experimental results demonstrate the effectiveness of proposed approach for discovery and matching of subsequences within sequentially generated patterns space of our experiments.

Relations between work and entropy production for general information-driven, finite-state engines

NASA Astrophysics Data System (ADS)

Merhav, Neri

2017-02-01

We consider a system model of a general finite-state machine (ratchet) that simultaneously interacts with three kinds of reservoirs: a heat reservoir, a work reservoir, and an information reservoir, the latter being taken to be a running digital tape whose symbols interact sequentially with the machine. As has been shown in earlier work, this finite-state machine can act as a demon (with memory), which creates a net flow of energy from the heat reservoir into the work reservoir (thus extracting useful work) at the price of increasing the entropy of the information reservoir. Under very few assumptions, we propose a simple derivation of a family of inequalities that relate the work extraction with the entropy production. These inequalities can be seen as either upper bounds on the extractable work or as lower bounds on the entropy production, depending on the point of view. Many of these bounds are relatively easy to calculate and they are tight in the sense that equality can be approached arbitrarily closely. In their basic forms, these inequalities are applicable to any finite number of cycles (and not only asymptotically), and for a general input information sequence (possibly correlated), which is not necessarily assumed even stationary. Several known results are obtained as special cases.

Screening antimicrobial activity of various extracts of Urtica dioica.

PubMed

Modarresi-Chahardehi, Amir; Ibrahim, Darah; Fariza-Sulaiman, Shaida; Mousavi, Leila

2012-12-01

Urtica dioica or stinging nettle is traditionally used as an herbal medicine in Western Asia. The current study represents the investigation of antimicrobial activity of U. dioica from nine crude extracts that were prepared using different organic solvents, obtained from two extraction methods: the Soxhlet extractor (Method I), which included the use of four solvents with ethyl acetate and hexane, or the sequential partitions (Method II) with a five solvent system (butanol). The antibacterial and antifungal activities of crude extracts were tested against 28 bacteria, three yeast strains and seven fungal isolates by the disc diffusion and broth dilution methods. Amoxicillin was used as positive control for bacteria strains, vancomycin for Streptococcus sp., miconazole nitrate (30 microg/mL) as positive control for fungi and yeast, and pure methanol (v/v) as negative control. The disc diffusion assay was used to determine the sensitivity of the samples, whilst the broth dilution method was used for the determination of the minimal inhibition concentration (MIC). The ethyl acetate and hexane extract from extraction method I (EA I and HE I) exhibited highest inhibition against some pathogenic bacteria such as Bacillus cereus, MRSA and Vibrio parahaemolyticus. A selection of extracts that showed some activity was further tested for the MIC and minimal bactericidal concentrations (MBC). MIC values of Bacillus subtilis and Methicillin-resistant Staphylococcus aureus (MRSA) using butanol extract of extraction method II (BE II) were 8.33 and 16.33mg/mL, respectively; while the MIC value using ethyl acetate extract of extraction method II (EAE II) for Vibrio parahaemolyticus was 0.13mg/mL. Our study showed that 47.06% of extracts inhibited Gram-negative (8 out of 17), and 63.63% of extracts also inhibited Gram-positive bacteria (7 out of 11); besides, statistically the frequency of antimicrobial activity was 13.45% (35 out of 342) which in this among 21.71% belongs to antimicrobial activity extracts from extraction method I (33 out of 152 of crude extracts) and 6.82% from extraction method II (13 out of 190 of crude extracts). However, crude extracts from method I exhibited better antimicrobial activity against the Gram-positive bacteria than the Gram-negative bacteria. The positive results on medicinal plants screening for antibacterial activity constitutes primary information for further phytochemical and pharmacological studies. Therefore, the extracts could be suitable as antimicrobial agents in pharmaceutical and food industry.

A novel algorithm to detect glaucoma risk using texton and local configuration pattern features extracted from fundus images.

PubMed

Acharya, U Rajendra; Bhat, Shreya; Koh, Joel E W; Bhandary, Sulatha V; Adeli, Hojjat

2017-09-01

Glaucoma is an optic neuropathy defined by characteristic damage to the optic nerve and accompanying visual field deficits. Early diagnosis and treatment are critical to prevent irreversible vision loss and ultimate blindness. Current techniques for computer-aided analysis of the optic nerve and retinal nerve fiber layer (RNFL) are expensive and require keen interpretation by trained specialists. Hence, an automated system is highly desirable for a cost-effective and accurate screening for the diagnosis of glaucoma. This paper presents a new methodology and a computerized diagnostic system. Adaptive histogram equalization is used to convert color images to grayscale images followed by convolution of these images with Leung-Malik (LM), Schmid (S), and maximum response (MR4 and MR8) filter banks. The basic microstructures in typical images are called textons. The convolution process produces textons. Local configuration pattern (LCP) features are extracted from these textons. The significant features are selected using a sequential floating forward search (SFFS) method and ranked using the statistical t-test. Finally, various classifiers are used for classification of images into normal and glaucomatous classes. A high classification accuracy of 95.8% is achieved using six features obtained from the LM filter bank and the k-nearest neighbor (kNN) classifier. A glaucoma integrative index (GRI) is also formulated to obtain a reliable and effective system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phytoremediation of agriculture runoff by filamentous algae poly-culture for biomethane production, and nutrient recovery for secondary cultivation of lipid generating microalgae.

PubMed

Bohutskyi, Pavlo; Chow, Steven; Ketter, Ben; Fung Shek, Coral; Yacar, Dean; Tang, Yuting; Zivojnovich, Mark; Betenbaugh, Michael J; Bouwer, Edward J

2016-12-01

An integrated system was implemented for water phytoremediation and biofuel production through sequential cultivation of filamentous algae followed by cultivation of lipid-producing microalgae Chlorella sorokiniana. Natural poly-culture of filamentous algae was grown in agricultural stormwater using the Algal Turf Scrubber®, harvested and subjected for lipid extraction and/or methane production using anaerobic digestion (AD). While filamentous algae lipid content was too low for feasible biodiesel production (<2%), both whole biomass and lipid-extracted algal residues (LEA) yielded ∼0.2LmethanepergVS at loading rates up to 5gVS/L-day. Importantly, essential macro-nutrients and trace elements captured from stormwater were released into the AD effluent as soluble nutrients and were successfully tested as fertilizer replacement for cultivation of lipid-accumulating C. sorokiniana in a subsequent stage. Accordingly, filamentous algae poly-culture was exploited for waste nutrient capturing and biofuel feedstock generation. These nutrients were recovered and reused as a concentrated supplement for potentially high-value microalgae. Published by Elsevier Ltd.

Anticipatory other-completion of augmentative and alternative communication talk: a conversation analysis study.

PubMed

Bloch, Steven

2011-01-01

The study described here investigates the practice of anticipatory completion of augmentative and alternative communication (AAC) utterances in progress. The aims were to identify and analyse features of this practice as they occur in natural conversation between a person using an AAC system and a family member. The methods and principles of Conversation Analysis (CA) were used to video record conversations between people with progressive neurological diseases and a progressive speech disorder (dysarthria) and their family members. Key features of interaction were identified and extracts transcribed. Four extracts of talk between a man with motor neurone disease/amyotrophic lateral sclerosis and his mother are presented here. Anticipatory completion of AAC utterances is intimately related to the sequential context in which such utterances occur. Difficulties can arise from topic shifts, understanding the intended action of an AAC word in progress and in recognising the possible end point an utterance. The analysis highlights the importance of understanding how AAC talk works in everyday interaction. The role of co-participants is particularly important here. These results may have implications for both AAC software design and clinical intervention.

Extraction Methods in Soil Phosphorus Characterisation

NASA Astrophysics Data System (ADS)

Soinne, Helena

2010-05-01

Extraction methods are widely used to assess the bioavailability of P and to characterise soil P reserves. Even though new and more sophisticated methods to characterise soil P are constantly developed the use of extraction methods is not likely to be replaced because of the relatively simple analytical equipment needed for the analysis. However, the large variety of extractants, pre-treatments and sample preparation procedures complicate the comparison of published results. In order to improve our understanding of the behaviour and cycling of P in soil, it is important to know the role of extracted P in the soil P cycle. The knowledge of the factors affecting the analytical outcome is a prerequisite for justified interpretation of the results. In this study, the effect of sample pre-treatment and properties of the used extractant on extractable molybdate-reactive phosphorus (MRP) and molybdate-unreactive phosphorus (MUP) was studied. Furthermore, the effect of sample preparation procedures prior the analysis on measured MRP and MUP was studied. Two widely used sequential extraction procedures were compared on their ability to show management induced differences on soil P. These results revealed that pre-treatments changed soil properties and air-drying was found to affect soil P, particularly extractable MUP, thought to represent organic P, by disrupting organic matter. This was evidenced by an increase in the water-extractable small-sized (<0.2 µm) P that, at least partly, took place at the expense of the large-sized (>0.2 µm) P. In addition to the effects of sample pre-treatment, the results showed that extractable organic P was sensitive to the chemical nature of the used extractant and to the sample preparation procedures employed prior to P analysis, including centrifugation and filtering of soil suspensions. Filtering may remove a major proportion of extractable MUP; therefore filtering cannot be recommended in the characterisation of solubilised MUP. However, extractants having high ionic strength may cause the organic molecules to collapse during centrifugation and thus affect the recovered concentration of MUP. These findings highlight the importance of characterising the nature of the MUP extracted with different extractants and acknowledging the sensitivity of MUP to analytical procedures when comparing published results. Widely used sequential fractionation procedures proved to be able to detect land-use -derived differences in the distribution of P among fractions of different solubilities. The results of this study demonstrate that, although the extraction methods do not reveal the biogeochemical function of a given P pool in soil, the extraction methods can be used to detect changes in soil P pools with different solubilities. To obtain the most benefit from extraction methods, we need a better understanding of the biological availability of P and the role of extracted P fraction in the P cycle in soils from different environments (climatic and weather) and land-uses.

A comparison study on detection of key geochemical variables and factors through three different types of factor analysis

NASA Astrophysics Data System (ADS)

Hoseinzade, Zohre; Mokhtari, Ahmad Reza

2017-10-01

Large numbers of variables have been measured to explain different phenomena. Factor analysis has widely been used in order to reduce the dimension of datasets. Additionally, the technique has been employed to highlight underlying factors hidden in a complex system. As geochemical studies benefit from multivariate assays, application of this method is widespread in geochemistry. However, the conventional protocols in implementing factor analysis have some drawbacks in spite of their advantages. In the present study, a geochemical dataset including 804 soil samples collected from a mining area in central Iran in order to search for MVT type Pb-Zn deposits was considered to outline geochemical analysis through various fractal methods. Routine factor analysis, sequential factor analysis, and staged factor analysis were applied to the dataset after opening the data with (additive logratio) alr-transformation to extract mineralization factor in the dataset. A comparison between these methods indicated that sequential factor analysis has more clearly revealed MVT paragenesis elements in surface samples with nearly 50% variation in F1. In addition, staged factor analysis has given acceptable results while it is easy to practice. It could detect mineralization related elements while larger factor loadings are given to these elements resulting in better pronunciation of mineralization.

River velocities from sequential multispectral remote sensing images

NASA Astrophysics Data System (ADS)

Chen, Wei; Mied, Richard P.

2013-06-01

We address the problem of extracting surface velocities from a pair of multispectral remote sensing images over rivers using a new nonlinear multiple-tracer form of the global optimal solution (GOS). The derived velocity field is a valid solution across the image domain to the nonlinear system of equations obtained by minimizing a cost function inferred from the conservation constraint equations for multiple tracers. This is done by deriving an iteration equation for the velocity, based on the multiple-tracer displaced frame difference equations, and a local approximation to the velocity field. The number of velocity equations is greater than the number of velocity components, and thus overly constrain the solution. The iterative technique uses Gauss-Newton and Levenberg-Marquardt methods and our own algorithm of the progressive relaxation of the over-constraint. We demonstrate the nonlinear multiple-tracer GOS technique with sequential multispectral Landsat and ASTER images over a portion of the Potomac River in MD/VA, and derive a dense field of accurate velocity vectors. We compare the GOS river velocities with those from over 12 years of data at four NOAA reference stations, and find good agreement. We discuss how to find the appropriate spatial and temporal resolutions to allow optimization of the technique for specific rivers.

Constrained optimization of sequentially generated entangled multiqubit states

NASA Astrophysics Data System (ADS)

Saberi, Hamed; Weichselbaum, Andreas; Lamata, Lucas; Pérez-García, David; von Delft, Jan; Solano, Enrique

2009-08-01

We demonstrate how the matrix-product state formalism provides a flexible structure to solve the constrained optimization problem associated with the sequential generation of entangled multiqubit states under experimental restrictions. We consider a realistic scenario in which an ancillary system with a limited number of levels performs restricted sequential interactions with qubits in a row. The proposed method relies on a suitable local optimization procedure, yielding an efficient recipe for the realistic and approximate sequential generation of any entangled multiqubit state. We give paradigmatic examples that may be of interest for theoretical and experimental developments.

Sequential Events Control System (SECS) Overview

NASA Technical Reports Server (NTRS)

Interbartolo, Michael

2009-01-01

This slide presentation will cover the Sequential Events Control System (SECS), which is the Apollo spacecraft subsystem that controls the automatically sequenced functions during the mission and during any a borts that could be performed. Included in this presentation are its general architecture, its integration into and use of the spacecraft' s other systems, and details on the functions it is responsible for c ontrolling during the mission. The objectives are to describe the system's architecture, the major components in the system, and the major system functions.

Immunocontraceptive activity guided fractionation and characterization of active constituents of neem (Azadirachta indica) seed extracts.

PubMed

Garg, S; Talwar, G P; Upadhyay, S N

1998-04-01

A novel approach for immunocontraception by intervention of local cell mediated immunity in the reproductive system by using single intrauterine application of neem oil has been described earlier. The reversible block in fertility was reported to last for 107-180 days in female Wistar rats (Upadhyay et al., 1990. Antifertility effects of neem oil by single intrauterine administration: A novel method of contraception. Proceedings Of The Royal Society Of London B 242, 175-180) and 7-11 months in monkeys (Upadhyay et al., 1994. Long term contraceptive effects of intrauterine neem treatment (IUNT) in bonnet monkeys: An alternative to intrauterine contraceptive devices. Contraception 49, 161-167). The present study, describes the identification and characterization of the biologically active fraction from neem seeds (Azadirachta indica A. Juss. Family Meliaceae), responsible for the above activity in adult female Wistar rats. Initial studies with the mechanically extracted oil and solvent extracts of neem seeds have revealed that the antifertility activity was present in constituents of low to intermediate polarity. A hexane extract of neem seeds was reported to be biologically active (Garg et al., 1994. Comparison of extraction procedures on the immunocontraceptive activity of neem seed extracts. Journal of Ethnopharmacology 22, 87-92). Subsequently, hexane extract was sequentially fractionated through the last active fraction using various separation techniques and tested for antifertility activity at each step. Preparative HPLC was used for isolating individual components of the active fraction in quantities, sufficient for characterization. An analytical HPLC method was developed for standardization of the fraction. The active fraction was identified to be a mixture of six components, which comprises of saturated, mono and di-unsaturated free fatty acids and their methyl esters. Dose response study was performed with the last active fractions. The antifertility activity with the active fraction was reversible in nature and it was completely active until 5% concentration. There was no systemic toxic effect following the administration of the active fraction. This study, for the first time, proposes an active fraction from neem seeds, responsible for long term and reversible blocking of fertility after a single intrauterine administration with high efficacy.

In-vitro alpha amylase inhibitory activity of the leaf extracts of Adenanthera pavonina.

PubMed

Wickramaratne, M Nirmali; Punchihewa, J C; Wickramaratne, D B M

2016-11-15

Diabetes has caused a major burden to the health sector in the developing countries and has shown an increasing trend among the urban population. It is estimated that most patients are with type II diabetes which could be easily treated with dietary changes, exercise, and medication. Sri Lanka carries a long history ayurvedic medicine where it uses the plant for treating many diseases. Therefore it is important to screen medicinal plants scientifically so they could be used safely and effectively in the traditional medical system and also be used for further investigations. Adenanthera pavonina is a plant used in the Ayurvedic medical system in Sri Lanka for treating many diseases including diabetics. We evaluated the anti-diabetic properties and the antioxidant properties of Adenanthera pavonina leaves. The methanol extract of the leaves was sequentially extracted with petroleum ether and thereafter was partitioned between EtOAc, and water. The α-amylase inhibition assay was performed using the 3,5- dinitrosalicylic acid method. The antioxidant activities were measured using the DPPH free radical scavenging activity and the total phenolic content using Folin-Ciocalteu's reagent. The cytotoxicity of the extract was evaluated using the Brine shrimp bioassay. The IC 50 values of α amylase inhibitory activity of MeOH, EtOAc, petroleum ether, and water were 16.16 ± 2.23, 59.93 ± 0.25, 145.49 ± 4.86 and 214.85 ± 9.72 μg/ml respectively and was similar to that of Acarbose (18.63 ± 1.21 (μg/ml). Antioxidant activities were also determined and the EtOAc fraction showed the highest total phenolic content (34. 62 ± 1.14 mg/g extract) and the highest DPPH scavenging activity with an IC 50 of 249.92 ± 3.35 μg/ml. The leaf extracts of Adenanthera pavonina exhibit remarkable α-amylase inhibitory activity in the crude methanolic extract. Hence leaves of Adenanthera pavonina has a potential to be used as a regular green vegetable and also be investigated further in isolating pure compounds with anti-diabetic activity.

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

Bae, Wookeun; Shin, Eung Bai; Lee, Kil Chul

The potential hazard of landfill wastes was previously evaluated by examining the extraction procedures for individual waste, although various wastes were co-disposed of in actual landfills. This paper investigates the reduction of extraction-procedure toxicity by co-disposing various combinations of two wastes. When two wastes are mixed homogeneously, the extraction of heavy metals from the waste mixture is critically affected by the extract pH. Thus, co-disposal wastes will have a resultant pH between the pH values of its constituent. The lower the resultant pH, the lower the concentrations of heavy metals in the extract. When these wastes are extracted sequentially, themore » latter extracted waste has a stronger influence on the final concentration of heavy metals in the extract. Small-scale lysimeter experiments confirm that when heavy-metal-bearing leachates Generated from hazardous-waste lysimeters are passed through a nonhazardous-waste lysimeter filled with compost, briquette ash, or refuse-incineration ashes, the heavy-metal concentration in the final leachates decreases significantly. Thus, the heavy-metal leaching could be attenuated if a less extraction-procedure-toxic waste were placed at the bottom of a landfill. 3 refs., 4 figs., 5 tabs.« less

Real-time text extraction based on the page layout analysis system

NASA Astrophysics Data System (ADS)

Soua, M.; Benchekroun, A.; Kachouri, R.; Akil, M.

2017-05-01

Several approaches were proposed in order to extract text from scanned documents. However, text extraction in heterogeneous documents stills a real challenge. Indeed, text extraction in this context is a difficult task because of the variation of the text due to the differences of sizes, styles and orientations, as well as to the complexity of the document region background. Recently, we have proposed the improved hybrid binarization based on Kmeans method (I-HBK)5 to extract suitably the text from heterogeneous documents. In this method, the Page Layout Analysis (PLA), part of the Tesseract OCR engine, is used to identify text and image regions. Afterwards our hybrid binarization is applied separately on each kind of regions. In one side, gamma correction is employed before to process image regions. In the other side, binarization is performed directly on text regions. Then, a foreground and background color study is performed to correct inverted region colors. Finally, characters are located from the binarized regions based on the PLA algorithm. In this work, we extend the integration of the PLA algorithm within the I-HBK method. In addition, to speed up the separation of text and image step, we employ an efficient GPU acceleration. Through the performed experiments, we demonstrate the high F-measure accuracy of the PLA algorithm reaching 95% on the LRDE dataset. In addition, we illustrate the sequential and the parallel compared PLA versions. The obtained results give a speedup of 3.7x when comparing the parallel PLA implementation on GPU GTX 660 to the CPU version.

TDRSS-user orbit determination using batch least-squares and sequential methods

NASA Astrophysics Data System (ADS)

Oza, D. H.; Jones, T. L.; Hakimi, M.; Samii, Mina V.; Doll, C. E.; Mistretta, G. D.; Hart, R. C.

1993-02-01

The Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) commissioned Applied Technology Associates, Incorporated, to develop the Real-Time Orbit Determination/Enhanced (RTOD/E) system on a Disk Operating System (DOS)-based personal computer (PC) as a prototype system for sequential orbit determination of spacecraft. This paper presents the results of a study to compare the orbit determination accuracy for a Tracking and Data Relay Satellite System (TDRSS) user spacecraft, Landsat-4, obtained using RTOD/E, operating on a PC, with the accuracy of an established batch least-squares system, the Goddard Trajectory Determination System (GTDS), and operating on a mainframe computer. The results of Landsat-4 orbit determination will provide useful experience for the Earth Observing System (EOS) series of satellites. The Landsat-4 ephemerides were estimated for the January 17-23, 1991, timeframe, during which intensive TDRSS tracking data for Landsat-4 were available. Independent assessments were made of the consistencies (overlap comparisons for the batch case and covariances and the first measurement residuals for the sequential case) of solutions produced by the batch and sequential methods. The forward-filtered RTOD/E orbit solutions were compared with the definitive GTDS orbit solutions for Landsat-4; the solution differences were less than 40 meters after the filter had reached steady state.

TDRSS-user orbit determination using batch least-squares and sequential methods

NASA Technical Reports Server (NTRS)

Oza, D. H.; Jones, T. L.; Hakimi, M.; Samii, Mina V.; Doll, C. E.; Mistretta, G. D.; Hart, R. C.

1993-01-01

The Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) commissioned Applied Technology Associates, Incorporated, to develop the Real-Time Orbit Determination/Enhanced (RTOD/E) system on a Disk Operating System (DOS)-based personal computer (PC) as a prototype system for sequential orbit determination of spacecraft. This paper presents the results of a study to compare the orbit determination accuracy for a Tracking and Data Relay Satellite System (TDRSS) user spacecraft, Landsat-4, obtained using RTOD/E, operating on a PC, with the accuracy of an established batch least-squares system, the Goddard Trajectory Determination System (GTDS), and operating on a mainframe computer. The results of Landsat-4 orbit determination will provide useful experience for the Earth Observing System (EOS) series of satellites. The Landsat-4 ephemerides were estimated for the January 17-23, 1991, timeframe, during which intensive TDRSS tracking data for Landsat-4 were available. Independent assessments were made of the consistencies (overlap comparisons for the batch case and covariances and the first measurement residuals for the sequential case) of solutions produced by the batch and sequential methods. The forward-filtered RTOD/E orbit solutions were compared with the definitive GTDS orbit solutions for Landsat-4; the solution differences were less than 40 meters after the filter had reached steady state.

On the Use of Adaptive Instructional Images Based on the Sequential-Global Dimension of the Felder-Silverman Learning Style Theory

ERIC Educational Resources Information Center

Filippidis, Stavros K.; Tsoukalas, Ioannis A.

2009-01-01

An adaptive educational system that uses adaptive presentation is presented. In this system fragments of different images present the same content and the system can choose the one most relevant to the user based on the sequential-global dimension of Felder-Silverman's learning style theory. In order to retrieve the learning style of each student…

Flavanoid-rich fraction from Sageretia theezans leaves scavenges reactive oxygen radical species and increases the resistance of low-density lipoprotein to oxidation

USDA-ARS?s Scientific Manuscript database

To explore their bioactive fractions, S. theezans leaves were extracted 2 with 60% acetone and then fractionated sequentially with hexane, ethyl acetate, and water. ROS (HOCl, ONOO-, and O2 deg -) scavenging activity, ORAC value and total phenolic content of each fraction were investigated. The ethy...

A Permeable Active Amendment Concrete (PAAC) for Contaminant Remediation and Erosion Control

DTIC Science & Technology

2012-06-01

124: 131 -143. SRNL-STI-2012-00356 70 Tessier, A., Campbell, P.G.C., and Bisson, M. 1979. Sequential extraction procedure for the speciation of...Bulk Density, Dry, (AI( C-D)]* p, pcf 134.85 Bulk Dens ity after Immersion, [BI(C-D)]* p, pcf 146.65 Bulk Density after Immersion & Boiling1 jCI (C

Evaluation of the accessibility of CCA metals in liquefied CCA-treated wood sludge for recovery and reuse

Treesearch

Hui Pan; Todd F. Shupe; Chung-Yun Hse

2009-01-01

CCA-treated wood was liquefied with polyethylene glycol/glycerin and sulfuric acid. The heavy metals were precipitated by Ca(OH)2 from liquefied CCA-treated wood. The original CCA-treated wood and precipitated wood sludge were fractionated by a modified BCR (Community Bureau of Reference) sequential extraction procedure. The purpose of the BCR...

Distribution and mode of occurrence of uranium in bottom ash derived from high-germanium coals.

PubMed

Sun, Yinglong; Qi, Guangxia; Lei, Xuefei; Xu, Hui; Li, Lei; Yuan, Chao; Wang, Yi

2016-05-01

The radioactivity of uranium in radioactive coal bottom ash (CBA) may be a potential danger to the ambient environment and human health. Concerning the limited research on the distribution and mode of occurrence of uranium in CBA, we herein report our investigations into this topic using a number of techniques including a five-step Tessier sequential extraction, hydrogen fluoride (HF) leaching, Siroquant (Rietveld) quantification, magnetic separation, and electron probe microanalysis (EPMA). The Tessier sequential extraction showed that the uranium in the residual and Fe-Mn oxide fractions was dominant (59.1% and 34.9%, respectively). The former was mainly incorporated into aluminosilicates, retained with glass and cristobalite, whereas the latter was especially enriched in the magnetic fraction, of which about 50% was present with magnetite (Fe3O4) and the rest in other iron oxides. In addition, the uranium in the magnetic fraction was 2.6 times that in the non-magnetic fraction. The experimental findings in this work may be important for establishing an effective strategy to reduce radioactivity from CBA for the protection of our local environment. Copyright © 2015. Published by Elsevier B.V.

Evaluation of the mobility and pollution index of selected essential/toxic metals in paddy soil by sequential extraction method.

PubMed

Hasan, Maria; Kausar, Dilshad; Akhter, Gulraiz; Shah, Munir H

2018-01-01

Comparative distribution and mobility of selected essential and toxic metals in the paddy soil from district Sargodha, Pakistan was evaluated by the modified Community Bureau of Reference (mBCR) sequential extraction procedure. Most of the soil samples showed slightly alkaline nature while the soil texture was predominantly silty loam in nature. The metal contents were quantified in the exchangeable, reducible, oxidisable and residual fractions of the soil by flame atomic absorption spectrophotometry and the metal data were subjected to the statistical analyses in order to evaluate the mutual relationships among the metals in each fraction. Among the metals, Ca, Sr and Mn were found to be more mobile in the soil. A number of significant correlations between different metal pairs were noted in various fractions. Contamination factor, geoaccumulation index and enrichment factor revealed extremely severe enrichment/contamination for Cd; moderate to significant enrichment/contamination for Ni, Zn, Co and Pb while Cr, Sr, Cu and Mn revealed minimal to moderate contamination and accumulation in the soil. Multivariate cluster analysis showed significant anthropogenic intrusions of the metals in various fractions. Copyright © 2017 Elsevier Inc. All rights reserved.

Geochemical fractionation and pollution assessment of Zn, Cu, and Fe in surface sediments from Shadegan Wildlife Refuge, southwest of Iran.

PubMed

Chaharlang, Behnam Heidari; Bakhtiari, Alireza Riyahi; Mohammadi, Jahangard; Farshchi, Parvin

2017-09-01

This research focuses on the fractionation and distribution patterns of heavy metals (Zn, Cu, and Fe) in surficial sediments collected from Shadegan Wildlife Refuge, the biggest wetland in southern part of Iran, to provide an overall classification for the sources of metals in the study area using a sequential extraction method. For this purpose, a four-step sequential extraction technique was applied to define the partitioning of the metals into different geochemical phases of the sediment. The results illustrated that the average total level of Zn, Cu, and Fe in surface sediments were 55.20 ± 16.04, 22.86 ± 5.68, and 25,979.01 ± 6917.91 μg/g dw, respectively. On the average, the chemical partitioning of all metals in most stations was in the order of residual >oxidizable-organic > acid-reducible > exchangeable. In the same way, the results of calculated geochemical indices revealed that Cu, Zn, and Fe concentrations are mainly influenced by lithogenic origins. Compared with consensus-based SQGs, Cu was likely to result in occasionally harmful biological effects on the biota.

Determination of distributions of Cd, Cu, and Pb concentrations in sediments of a Mexican reservoir to infer their environmental risk.

PubMed

Barceló-Quintal, Icela Dagmar; Solís-Correa, Hugo Eduardo; Avila-Pérez, Pedro; López-Galván, Edgar; Gómez-Salazar, Sergio; García-Albortante, Julisa

2012-07-01

The José Antonio Alzate Dam in the State of Mexico, Mexico, receives wastewaters from domestic, industrial, and agricultural activities through the Lerma River. Chemical and physicochemical characteristics of the water were determined. Sediment has been studied in order to define the importance of its influence on the reservoir's state as a whole. The quantification of the metals, Cd, Cu, and Pb in total forms and the geochemical distribution and the chemical mobility of these metals in sediment have been established using a chemical sequential extraction scheme. The three metals showed a common characteristic, being more abundant in fraction F6 (residual), but the other fractions of the geochemical distribution were variable depending on the metal. First, the contamination level was evaluated with the results of the total metals, using the criteria of EPA, Thomas and Murdoch, and the Ontario Ministry of Environment for sediment in water bodies. Subsequently, the risk was assessed using the same criteria but considering the results of sequential extractions, where the geochemical distribution of each metal allowed a better understanding of metal portions with more influence on the risk, in which Cu and Pb presented low risk, but not Cd.

Source and migration of dissolved manganese in the Central Nile Delta Aquifer, Egypt

NASA Astrophysics Data System (ADS)

Bennett, P. C.; El Shishtawy, A. M.; Sharp, J. M.; Atwia, M. G.

2014-08-01

Dissolved metals in waters in shallow deltaic sediments are one of the world's major health problems, and a prime example is arsenic contamination in Bangladesh. The Central Nile Delta Aquifer, a drinking water source for more than 6 million people, can have high concentrations of dissolved manganese (Mn). Standard hydrochemical analyses coupled with sequential chemical extraction is used to identify the source of the Mn and to identify the probable cause of the contamination. Fifty-nine municipal supply wells were sampled and the results compared with published data for groundwaters and surface waters. Drill cuttings from 4 wells were collected and analyzed by sequential chemical extraction to test the hypothesized Mn-generating processes. The data from this research show that the Mn source is not deep saline water, microbial reduction of Mn oxides at the production depth, or leakage from irrigation drainage ditches. Instead, Mn associated with carbonate minerals in the surficial confining layer and transported down along the disturbed well annulus of the municipal supply wells is the likely source. This analysis provides a basis for future hydrogeological and contaminant transport modeling as well as remediation-modification of well completion practices and pumping schedules to mitigate the problem.

Characterization of co-products from producing ethanol by sequential extraction processing of corn

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

Hojilla-Evangelista, M.P.; Johnson, L.A.; Pometto, A.L. III

1996-12-31

Sequential Extraction Processing (SEP) is a new process for ethanol production that has potential to produce more valuable co-products than alternative processes. Previous work determined the yields of oil and protein and evaluated their chemical and functional properties. The properties of the crude fiber and spent solids, however, have yet to be studied. This research was conducted to evaluate the potential of SEP corn fiber to increase ethanol conversion and as replacement for gum arabic, and evaluate the potential of SEP starch and fiber to be fermented to ethanol. SEP hemicellulose from crude fiber was readily dispersible in water andmore » its solution (5%) gave low viscosity despite having high solids content. These properties indicated potential utilization as stabilizers, thickeners, and adhesive for coatings and batters in food and industrial products. Enzyme hydrolysis studies and batch fermentation of SEP starch/fiber indicated that SEP crude fiber was more readily accessible to the action of cellulases. More ethanol (about 10%) was produced from the fermentation of SEP starch/fiber than from undegermed or degermed soft dent corn, particularly when the hemicellulose fraction was absent from the SEP fiber.« less

Detection of Bacterial Pathogens from Broncho-Alveolar Lavage by Next-Generation Sequencing.

PubMed

Leo, Stefano; Gaïa, Nadia; Ruppé, Etienne; Emonet, Stephane; Girard, Myriam; Lazarevic, Vladimir; Schrenzel, Jacques

2017-09-20

The applications of whole-metagenome shotgun sequencing (WMGS) in routine clinical analysis are still limited. A combination of a DNA extraction procedure, sequencing, and bioinformatics tools is essential for the removal of human DNA and for improving bacterial species identification in a timely manner. We tackled these issues with a broncho-alveolar lavage (BAL) sample from an immunocompromised patient who had developed severe chronic pneumonia. We extracted DNA from the BAL sample with protocols based either on sequential lysis of human and bacterial cells or on the mechanical disruption of all cells. Metagenomic libraries were sequenced on Illumina HiSeq platforms. Microbial community composition was determined by k-mer analysis or by mapping to taxonomic markers. Results were compared to those obtained by conventional clinical culture and molecular methods. Compared to mechanical cell disruption, a sequential lysis protocol resulted in a significantly increased proportion of bacterial DNA over human DNA and higher sequence coverage of Mycobacterium abscessus , Corynebacterium jeikeium and Rothia dentocariosa , the bacteria reported by clinical microbiology tests. In addition, we identified anaerobic bacteria not searched for by the clinical laboratory. Our results further support the implementation of WMGS in clinical routine diagnosis for bacterial identification.

Prediction of anaerobic biodegradability and bioaccessibility of municipal sludge by coupling sequential extractions with fluorescence spectroscopy: towards ADM1 variables characterization.

PubMed

Jimenez, Julie; Gonidec, Estelle; Cacho Rivero, Jesús Andrés; Latrille, Eric; Vedrenne, Fabien; Steyer, Jean-Philippe

2014-03-01

Advanced dynamic anaerobic digestion models, such as ADM1, require both detailed organic matter characterisation and intimate knowledge of the involved metabolic pathways. In the current study, a methodology for municipal sludge characterization is investigated to describe two key parameters: biodegradability and bioaccessibility of organic matter. The methodology is based on coupling sequential chemical extractions with 3D fluorescence spectroscopy. The use of increasingly strong solvents reveals different levels of organic matter accessibility and the spectroscopy measurement leads to a detailed characterisation of the organic matter. The results obtained from testing 52 municipal sludge samples (primary, secondary, digested and thermally treated) showed a successful correlation with sludge biodegradability and bioaccessibility. The two parameters, traditionally obtained through the biochemical methane potential (BMP) lab tests, are now obtain in only 5 days compared to the 30-60 days usually required. Experimental data, obtained from two different laboratory scale reactors, were used to validate the ADM1 model. The proposed approach showed a strong application potential for reactor design and advanced control of anaerobic digestion processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of bamboo and rice straw biochars on the mobility and redistribution of heavy metals (Cd, Cu, Pb and Zn) in contaminated soil.

PubMed

Lu, Kouping; Yang, Xing; Gielen, Gerty; Bolan, Nanthi; Ok, Yong Sik; Niazi, Nabeel Khan; Xu, Song; Yuan, Guodong; Chen, Xin; Zhang, Xiaokai; Liu, Dan; Song, Zhaoliang; Liu, Xingyuan; Wang, Hailong

2017-01-15

Biochar has emerged as an efficient tool to affect bioavailability of heavy metals in contaminated soils. Although partially understood, a carefully designed incubation experiment was performed to examine the effect of biochar on mobility and redistribution of Cd, Cu, Pb and Zn in a sandy loam soil collected from the surroundings of a copper smelter. Bamboo and rice straw biochars with different mesh sizes (<0.25 mm and <1 mm), were applied at three rates (0, 1, and 5% w/w). Heavy metal concentrations in pore water were determined after extraction with 0.01 M CaCl 2 . Phytoavailable metals were extracted using DTPA/TEA (pH 7.3). The European Union Bureau of Reference (EUBCR) sequential extraction procedure was adopted to determine metal partitioning and redistribution of heavy metals. Results showed that CaCl 2 -and DTPA-extractable Cd, Cu, Pb and Zn concentrations were significantly (p < 0.05) lower in the bamboo and rice straw biochar treated soils, especially at 5% application rate, than those in the unamended soil. Soil pH values were significantly correlated with CaCl 2 -extractable metal concentrations (p < 0.01). The EUBCR sequential extraction procedure revealed that the acid extractable fractions of Cd, Cu, Pb and Zn decreased significantly (p < 0.05) with biochar addition. Rice straw biochar was more effective than bamboo biochar in decreasing the acid extractable metal fractions, and the effect was more pronounced with increasing biochar application rate. The effect of biochar particle size on extractable metal concentrations was not consistent. The 5% rice straw biochar treatment reduced the DTPA-extractable metal concentrations in the order of Cd < Cu < Pb < Zn, and reduced the acid extractable pool of Cd, Cu, Pb and Zn by 11, 17, 34 and 6%, respectively, compared to the control. In the same 5% rice straw biochar treatments, the organic bound fraction increased by 37, 58, 68 and 18% for Cd, Cu, Pb and Zn, respectively, compared to the control, indicating that the immobilized metals were mainly bound in the soil organic matter fraction. The results demonstrated that the rice straw biochar can effectively immobilize heavy metals, thereby reducing their mobility and bioavailability in contaminated soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Graphics processing unit accelerated intensity-based optical coherence tomography angiography using differential frames with real-time motion correction.

PubMed

Watanabe, Yuuki; Takahashi, Yuhei; Numazawa, Hiroshi

2014-02-01

We demonstrate intensity-based optical coherence tomography (OCT) angiography using the squared difference of two sequential frames with bulk-tissue-motion (BTM) correction. This motion correction was performed by minimization of the sum of the pixel values using axial- and lateral-pixel-shifted structural OCT images. We extract the BTM-corrected image from a total of 25 calculated OCT angiographic images. Image processing was accelerated by a graphics processing unit (GPU) with many stream processors to optimize the parallel processing procedure. The GPU processing rate was faster than that of a line scan camera (46.9 kHz). Our OCT system provides the means of displaying structural OCT images and BTM-corrected OCT angiographic images in real time.

The simultaneous quantitation of ten amino acids in soil extracts by mass fragmentography

NASA Technical Reports Server (NTRS)

Pereira, W. E.; Hoyano, Y.; Reynolds, W. E.; Summons, R. E.; Duffield, A. M.

1972-01-01

A specific and sensitive method for the identification and simultaneous quantitation by mass fragmentography of ten of the amino acids present in soil was developed. The technique uses a computer driven quadrupole mass spectrometer and a commercial preparation of deuterated amino acids is used as internal standards for purposes of quantitation. The results obtained are comparable with those from an amino acid analyzer. In the quadrupole mass spectrometer-computer system up to 25 pre-selected ions may be monitored sequentially. This allows a maximum of 12 different amino acids (one specific ion in each of the undeuterated and deuterated amino acid spectra) to be quantitated. The method is relatively rapid (analysis time of approximately one hour) and is capable of the quantitation of nanogram quantities of amino acids.

Anomalous gold, antimony, arsenic, and tungsten in ground water and alluvium around disseminated gold deposits along the Getchell Trend, Humboldt County, Nevada

USGS Publications Warehouse

Grimes, D.J.; Ficklin, W.H.; Meier, A.L.; McHugh, J.B.

1995-01-01

Ground-water, alluvium, and bedrock samples were collected from drill holes near the Chimney Creek, Preble, Summer Camp, and Rabbit Creek disseminated gold deposits in northern Nevada. Results of chemical analyses of drill-hole water samples show the presence of hydromorphic dispersion anomalies of Au, As, Sb, and W in the local ground-water systems associated with these deposits. In addition, analysis of sequential dissolution and extraction solutions of drill cuttings of alluvium and bedrock indicate geochemical anomalies of gold and ore-related metals in the overburden at depths corresponding to the location of the present-day water table. This relationship suggests that water-rock reactions around these buried deposits are active. -from Authors

Fast determination of trace elements in organic fertilizers using a cup-horn reactor for ultrasound-assisted extraction and fast sequential flame atomic absorption spectrometry.

PubMed

Teixeira, Leonel Silva; Vieira, Heulla Pereira; Windmöller, Cláudia Carvalhinho; Nascentes, Clésia Cristina

2014-02-01

A fast and accurate method based on ultrasound-assisted extraction in a cup-horn sonoreactor was developed to determine the total content of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn in organic fertilizers by fast sequential flame atomic absorption spectrometry (FS FAAS). Multivariate optimization was used to establish the optimal conditions for the extraction procedure. An aliquot containing approximately 120 mg of the sample was added to a 500 µL volume of an acid mixture (HNO3/HCl/HF, 5:3:3, v/v/v). After a few minutes, 500 µL of deionized water was added and eight samples were simultaneously sonicated for 10 min at 50% amplitude, allowing a sample throughput of 32 extractions per hour. The performance of the method was evaluated with a certified reference material of sewage sludge (CRM 029). The precision, expressed as the relative standard deviation, ranged from 0.58% to 5.6%. The recoveries of analytes were found to 100%, 109%, 96%, 92%, 101%, 104% and 102% for Cd, Cr, Cu, Mn, Ni, Pb and Zn, respectively. The linearity, limit of detection and limit of quantification were calculated and the values obtained were adequate for the quality control of organic fertilizers. The method was applied to the analysis of several commercial organic fertilizers and organic wastes used as fertilizers, and the results were compared with those obtained using the microwave digestion procedure. A good agreement was found between the results obtained by microwave and ultrasound procedures with recoveries ranging from 80.4% to 117%. Two organic waste samples were not in accordance with the Brazilian legislation regarding the acceptable levels of contaminants. © 2013 Published by Elsevier B.V.

Detection of platinum species in plant material.

PubMed

Messerschmidt, J; Alt, F; Tölg, G

1995-05-01

Model experiments for the detection of platinum species in extracts from native and platinum-treated grass cultivations are described. The procedural steps are cultivation of the grass samples, extraction and concentration of the platinum species by ultrafiltration and freeze-drying, preparative separation of the species by gel chromatography followed by isotachophoresis, and sequential analytical detection of the separated platinum species by adsorptive voltammetry. After isotachophoresis, sharp peaks of platinum species could be detected. In the native grass extract only one platinum species (160-200 kDa) was found. In the platinum-treated grass extracts several platinum species were observed in the molecular mass range from 1 to > 1000 kDa. By an extremely sensitive platinum determination method (adsorptive voltammetry; detection limit, 2 pg Pt abs.) it was possible to detect platinum even in stained protein bands from horizontal gel electrophoresis of platinum containing fractions obtained after isotachophoresis.

Synergism between ultrasonic pretreatment and white rot fungal enzymes on biodegradation of wheat chaff.

PubMed

Sabarez, Henry; Oliver, Christine Maree; Mawson, Raymond; Dumsday, Geoff; Singh, Tanoj; Bitto, Natalie; McSweeney, Chris; Augustin, Mary Ann

2014-11-01

Lignocellulosic biomass samples (wheat chaff) were pretreated by ultrasound (US) (40kHz/0.5Wcm(-2)/10min and 400kHz/0.5Wcm(-2)/10min applied sequentially) prior to digestion by enzyme extracts obtained from fermentation of the biomass with white rot fungi (Phanerochaete chrysosporium or Trametes sp.). The accessibility of the cellulosic components in wheat chaff was increased, as demonstrated by the increased concentration of sugars produced by exposure to the ultrasound treatment prior to enzyme addition. Pretreatment with ultrasound increased the concentration of lignin degradation products (guaiacol and syringol) obtained from wheat chaff after enzyme addition. In vitro digestibility of wheat chaff was also enhanced by the ultrasonics pretreatment in combination with treatment with enzyme extracts. Degradation was enhanced with the use of a mixture of the enzyme extracts compared to that for a single enzyme extract. Copyright © 2014. Published by Elsevier B.V.

Inhibition of norsolorinic acid accumulation to Aspergillus parasiticus by marine actinomycetes

NASA Astrophysics Data System (ADS)

Yan, Peisheng; Shi, Cuijuan; Shen, Jihong; Wang, Kai; Gao, Xiujun; Li, Ping

2014-11-01

Thirty-six strains of marine actinomycetes were isolated from a sample of marine sediment collected from the Yellow Sea and evaluated in terms of their inhibitory activity on the growth of Aspergillus parasiticus and the production of norsolorinic acid using dual culture plate assay and agar diffusion methods. Among them, three strains showed strong antifungal activity and were subsequently identified as Streptomyces sp. by 16S rRNA gene sequencing analysis. The supernatant from the fermentation of the MA01 strain was extracted sequentially with chloroform and ethyl acetate, and the activities of the extracts were determined by tip culture assay. The assay results show that both extracts inhibited mycelium growth and toxin production, and the inhibitory activities of the extracts increased as their concentrations increased. The results of this study suggest that marine actinomycetes are biologically important for the control of mycotoxins, and that these bacteria could be used as novel biopesticides against mycotoxins.

Distributed Immune Systems for Wireless Network Information Assurance

DTIC Science & Technology

2010-04-26

ratio test (SPRT), where the goal is to optimize a hypothesis testing problem given a trade-off between the probability of errors and the...using cumulative sum (CUSUM) and Girshik-Rubin-Shiryaev (GRSh) statistics. In sequential versions of the problem the sequential probability ratio ...the more complicated problems, in particular those where no clear mean can be established. We developed algorithms based on the sequential probability

Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), Inhibits Candida Biofilms: A Metabolomic Approach.

PubMed

Bhardwaj, Anuja; Gupta, Payal; Kumar, Navin; Mishra, Jigni; Kumar, Ajai; Rakhee, Rajput; Misra, Kshipra

2017-01-01

This article presents a comparative gas chromatography (GC)-mass spectrometry (MS)-based metabolomic analysis of mycelia and fruiting bodies of the medicinal mushroom Ganoderma lucidum. Three aqueous extracts-mycelia, fruiting bodies, and a mixture of them-and their sequential fractions (methanolic and ethyl acetate), prepared using an accelerated solvent extractor, were characterized by GC-MS to determine volatile organic compounds and by high-performance thin-layer chromatography to quantify ascorbic acid, a potent antioxidant. In addition, these extracts and fractions were assessed against Candida albicans and C. glabrata biofilms via the XTT reduction assay, and their antioxidant potential was evaluated. Application of chemometrics (hierarchical cluster analysis and principal component analysis) to GC data revealed variability in volatile organic compound profiles among G. lucidum extracts and fractions. The mycelial aqueous extract demonstrated higher anti-Candida activity and ascorbic acid content among all the extracts and fractions. Thus, this study illustrates the preventive effect of G. lucidum against C. albicans and C. glabrata biofilms along with its nutritional value.

Reproducible Tissue Homogenization and Protein Extraction for Quantitative Proteomics Using MicroPestle-Assisted Pressure-Cycling Technology.

PubMed

Shao, Shiying; Guo, Tiannan; Gross, Vera; Lazarev, Alexander; Koh, Ching Chiek; Gillessen, Silke; Joerger, Markus; Jochum, Wolfram; Aebersold, Ruedi

2016-06-03

The reproducible and efficient extraction of proteins from biopsy samples for quantitative analysis is a critical step in biomarker and translational research. Recently, we described a method consisting of pressure-cycling technology (PCT) and sequential windowed acquisition of all theoretical fragment ions-mass spectrometry (SWATH-MS) for the rapid quantification of thousands of proteins from biopsy-size tissue samples. As an improvement of the method, we have incorporated the PCT-MicroPestle into the PCT-SWATH workflow. The PCT-MicroPestle is a novel, miniaturized, disposable mechanical tissue homogenizer that fits directly into the microTube sample container. We optimized the pressure-cycling conditions for tissue lysis with the PCT-MicroPestle and benchmarked the performance of the system against the conventional PCT-MicroCap method using mouse liver, heart, brain, and human kidney tissues as test samples. The data indicate that the digestion of the PCT-MicroPestle-extracted proteins yielded 20-40% more MS-ready peptide mass from all tissues tested with a comparable reproducibility when compared to the conventional PCT method. Subsequent SWATH-MS analysis identified a higher number of biologically informative proteins from a given sample. In conclusion, we have developed a new device that can be seamlessly integrated into the PCT-SWATH workflow, leading to increased sample throughput and improved reproducibility at both the protein extraction and proteomic analysis levels when applied to the quantitative proteomic analysis of biopsy-level samples.

Analyzing Communication Architectures Using Commercial Off-The-Shelf (COTS) Modeling and Simulation Tools

DTIC Science & Technology

1998-06-01

4] By 2010, we should be able to change how we conduct the most intense joint operations. Instead of relying on massed forces and sequential ...not independent, sequential steps. Data probes to support the analysis phase were required to complete the logical models. This generated a need...Networks) Identify Granularity (System Level) - Establish Physical Bounds or Limits to Systems • Determine System Test Configuration and Lineup

Effect Of Soil Properties On The Geochemical Speciation Of Arsenic In Contaminated Soils: A Greenhouse Study

NASA Astrophysics Data System (ADS)

Sharma, S.; Sarkar, D.; Datta, R.

2005-05-01

Land-applied arsenical pesticides have contributed elevated soil arsenic (As) levels. Many baseline risk assessments As-contaminated sites assume that all As present in the soil is bioavailable, thereby potentially overestimating the actual health risk. However, risk from As exposure is associated only with those forms of As that are potentially extractable by the human gastrointestinal juices. It has been demonstrated that As may exist in several geochemical forms depending on soil chemical properties, which may or may not be bioavailable. The current study aims at addressing the issue of soil variability on As bioavailability as a function of soil physico-chemical properties in a greenhouse setting involving dynamic interactions between soil, water and plants. Four different soils were chosen based on their potential differences with respect to As reactivity: Immokalee, an acid sand with low extractable Fe/Al, having minimal arsenic retention capacity; Millhopper, an acid sandy loam with high extractable Fe/Al oxides; Pahokee Muck soil with 85% soil organic matter (SOM) as well as high Fe/Al content; and Orelia soil with high clay and Fe/Al content. Soils were amended with sodium arsenate (675 and 1500 mg/Kg). Rice (Oryza sativa) was used as the test crop. A sequential extraction scheme was employed to identify the geochemical forms of As in soils (soluble, exchangeable, organic, Fe/Al-bound, Ca/Mg-bound, residual) immediately after spiking; after 3 mo; and after 6 mo of equilibration time. Concentrations of these As forms were correlated with the in-vitro bioavailable As fractions to identify those As fractions that are most likely to be bioavailable. Results from this study showed that there was little to no plant growth in the contaminated soils. Sequential extractions of the soil indicated that arsenic is strongly adsorbed onto soil amorphous iron/aluminum oxides, and the degree of arsenic retention is a direct function of equilibration time.

Comparison of ERBS orbit determination accuracy using batch least-squares and sequential methods

NASA Technical Reports Server (NTRS)

Oza, D. H.; Jones, T. L.; Fabien, S. M.; Mistretta, G. D.; Hart, R. C.; Doll, C. E.

1991-01-01

The Flight Dynamics Div. (FDD) at NASA-Goddard commissioned a study to develop the Real Time Orbit Determination/Enhanced (RTOD/E) system as a prototype system for sequential orbit determination of spacecraft on a DOS based personal computer (PC). An overview is presented of RTOD/E capabilities and the results are presented of a study to compare the orbit determination accuracy for a Tracking and Data Relay Satellite System (TDRSS) user spacecraft obtained using RTOS/E on a PC with the accuracy of an established batch least squares system, the Goddard Trajectory Determination System (GTDS), operating on a mainframe computer. RTOD/E was used to perform sequential orbit determination for the Earth Radiation Budget Satellite (ERBS), and the Goddard Trajectory Determination System (GTDS) was used to perform the batch least squares orbit determination. The estimated ERBS ephemerides were obtained for the Aug. 16 to 22, 1989, timeframe, during which intensive TDRSS tracking data for ERBS were available. Independent assessments were made to examine the consistencies of results obtained by the batch and sequential methods. Comparisons were made between the forward filtered RTOD/E orbit solutions and definitive GTDS orbit solutions for ERBS; the solution differences were less than 40 meters after the filter had reached steady state.

Comparison of ERBS orbit determination accuracy using batch least-squares and sequential methods

NASA Astrophysics Data System (ADS)

Oza, D. H.; Jones, T. L.; Fabien, S. M.; Mistretta, G. D.; Hart, R. C.; Doll, C. E.

1991-10-01

The Flight Dynamics Div. (FDD) at NASA-Goddard commissioned a study to develop the Real Time Orbit Determination/Enhanced (RTOD/E) system as a prototype system for sequential orbit determination of spacecraft on a DOS based personal computer (PC). An overview is presented of RTOD/E capabilities and the results are presented of a study to compare the orbit determination accuracy for a Tracking and Data Relay Satellite System (TDRSS) user spacecraft obtained using RTOS/E on a PC with the accuracy of an established batch least squares system, the Goddard Trajectory Determination System (GTDS), operating on a mainframe computer. RTOD/E was used to perform sequential orbit determination for the Earth Radiation Budget Satellite (ERBS), and the Goddard Trajectory Determination System (GTDS) was used to perform the batch least squares orbit determination. The estimated ERBS ephemerides were obtained for the Aug. 16 to 22, 1989, timeframe, during which intensive TDRSS tracking data for ERBS were available. Independent assessments were made to examine the consistencies of results obtained by the batch and sequential methods. Comparisons were made between the forward filtered RTOD/E orbit solutions and definitive GTDS orbit solutions for ERBS; the solution differences were less than 40 meters after the filter had reached steady state.

Geochemical behavior, environmental availability, and reconstruction of historical trends of Cu, Pb, and Zn in sediment cores of the Cananéia-Iguape coastal system, Southeastern Brazil.

PubMed

Tramonte, Keila Modesto; Figueira, Rubens Cesar Lopes; Majer, Alessandra Pereira; de Lima Ferreira, Paulo Alves; Batista, Miriam Fernanda; Ribeiro, Andreza Portella; de Mahiques, Michel Michaelovitch

2018-02-01

The Cananéia-Iguape system is located in a coastal region of southeastern Brazil, recognized by UNESCO as an Atlantic Forest Biosphere Reserve. This system has suffered substantial environmental impacts due to the opening of an artificial channel and by past intensive mining activities. In this paper was performed the sequential chemical extraction of Cu, Pb, and Zn, on previously described sediment cores, and the statistical treatment of the data, allowing to estimate the remobilization geochemical behavior, the available content and the trend of accumulation between 1926 and 2008. The maximum available level (sum of all mobile fraction) were, in mgkg -1 , 18.74 for Cu, 177.55 for Pb and 123.03 for Zn. Considering its environmental availability, Pb remains a concern in the system. It was possible to recognize the anthropic contribution of Pb, being the mining activities considered the only potential source of this metal in the region. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimal sequential measurements for bipartite state discrimination

NASA Astrophysics Data System (ADS)

Croke, Sarah; Barnett, Stephen M.; Weir, Graeme

2017-05-01

State discrimination is a useful test problem with which to clarify the power and limitations of different classes of measurement. We consider the problem of discriminating between given states of a bipartite quantum system via sequential measurement of the subsystems, with classical feed-forward of measurement results. Our aim is to understand when sequential measurements, which are relatively easy to implement experimentally, perform as well, or almost as well, as optimal joint measurements, which are in general more technologically challenging. We construct conditions that the optimal sequential measurement must satisfy, analogous to the well-known Helstrom conditions for minimum error discrimination in the unrestricted case. We give several examples and compare the optimal probability of correctly identifying the state via global versus sequential measurement strategies.

Hospital's activity-based financing system and manager-physician [corrected] interaction.

PubMed

Crainich, David; Leleu, Hervé; Mauleon, Ana

2011-10-01

This paper examines the consequences of the introduction of an activity-based reimbursement system on the behavior of physicians and hospital's managers. We consider a private for-profit sector where both hospitals and physicians are initially paid on a fee-for-service basis. We show that the benefit of the introduction of an activity-based system depends on the type of interaction between managers and physicians (simultaneous or sequential decision-making games). It is shown that, under the activity-based system, a sequential interaction with physician leader could be beneficial for both agents in the private sector. We further model an endogenous timing game à la Hamilton and Slutsky (Games Econ Behav 2: 29-46, 1990) in which the type of interaction is determined endogenously. We show that, under the activity-based system, the sequential interaction with physician leader is the unique subgame perfect equilibrium.

Determination of cadmium and lead in table salt by sequential multi-element flame atomic absorption spectrometry.

PubMed

Amorim, Fábio A C; Ferreira, Sérgio L C

2005-02-28

In the present paper, a simultaneous pre-concentration procedure for the sequential determination of cadmium and lead in table salt samples using flame atomic absorption spectrometry is proposed. This method is based on the liquid-liquid extraction of cadmium(II) and lead(II) ions as dithizone complexes and direct aspiration of the organic phase for the spectrometer. The sequential determination of cadmium and lead is possible using a computer program. The optimization step was performed by a two-level fractional factorial design involving the variables: pH, dithizone mass, shaking time after addition of dithizone and shaking time after addition of solvent. In the studied levels these variables are not significant. The experimental conditions established propose a sample volume of 250mL and the extraction process using 4.0mL of methyl isobutyl ketone. This way, the procedure allows determination of cadmium and lead in table salt samples with a pre-concentration factor higher than 80, and detection limits of 0.3ngg(-1) for cadmium and 4.2ngg(-1) for lead. The precision expressed as relative standard deviation (n = 10) were 5.6 and 2.6% for cadmium concentration of 2 and 20ngg(-1), respectively, and of 3.2 and 1.1% for lead concentration of 20 and 200ngg(-1), respectively. Recoveries of cadmium and lead in several samples, measured by standard addition technique, proved also that this procedure is not affected by the matrix and can be applied satisfactorily for the determination of cadmium and lead in saline samples. The method was applied for the evaluation of the concentration of cadmium and lead in table salt samples consumed in Salvador City, Bahia, Brazil.

Vigi4Med Scraper: A Framework for Web Forum Structured Data Extraction and Semantic Representation

PubMed Central

Audeh, Bissan; Beigbeder, Michel; Zimmermann, Antoine; Jaillon, Philippe; Bousquet, Cédric

2017-01-01

The extraction of information from social media is an essential yet complicated step for data analysis in multiple domains. In this paper, we present Vigi4Med Scraper, a generic open source framework for extracting structured data from web forums. Our framework is highly configurable; using a configuration file, the user can freely choose the data to extract from any web forum. The extracted data are anonymized and represented in a semantic structure using Resource Description Framework (RDF) graphs. This representation enables efficient manipulation by data analysis algorithms and allows the collected data to be directly linked to any existing semantic resource. To avoid server overload, an integrated proxy with caching functionality imposes a minimal delay between sequential requests. Vigi4Med Scraper represents the first step of Vigi4Med, a project to detect adverse drug reactions (ADRs) from social networks founded by the French drug safety agency Agence Nationale de Sécurité du Médicament (ANSM). Vigi4Med Scraper has successfully extracted greater than 200 gigabytes of data from the web forums of over 20 different websites. PMID:28122056

Automated process for solvent separation of organic/inorganic substance

DOEpatents

Schweighardt, F.K.

1986-07-29

There is described an automated process for the solvent separation of organic/inorganic substances that operates continuously and unattended and eliminates potential errors resulting from subjectivity and the aging of the sample during analysis. In the process, metered amounts of one or more solvents are passed sequentially through a filter containing the sample under the direction of a microprocessor control apparatus. The mixture in the filter is agitated by ultrasonic cavitation for a timed period and the filtrate is collected. The filtrate of each solvent extraction is collected individually and the residue on the filter element is collected to complete the extraction process. 4 figs.

Automated process for solvent separation of organic/inorganic substance

DOEpatents

Schweighardt, Frank K.

1986-01-01

There is described an automated process for the solvent separation of organic/inorganic substances that operates continuously and unattended and eliminates potential errors resulting from subjectivity and the aging of the sample during analysis. In the process, metered amounts of one or more solvents are passed sequentially through a filter containing the sample under the direction of a microprocessor control apparatus. The mixture in the filter is agitated by ultrasonic cavitation for a timed period and the filtrate is collected. The filtrate of each solvent extraction is collected individually and the residue on the filter element is collected to complete the extraction process.

Automated apparatus for solvent separation of a coal liquefaction product stream

DOEpatents

Schweighardt, Frank K.

1985-01-01

An automated apparatus for the solvent separation of a coal liquefaction product stream that operates continuously and unattended and eliminates potential errors resulting from subjectivity and the aging of the sample during analysis. In use of the apparatus, metered amounts of one or more solvents are passed sequentially through a filter containing the sample under the direction of a microprocessor control means. The mixture in the filter is agitated by means of ultrasonic cavitation for a timed period and the filtrate is collected. The filtrate of each solvent extraction is collected individually and the residue on the filter element is collected to complete the extraction process.

Intercropped Pteris vittata L. and Morus alba L. presents a safe utilization mode for arsenic-contaminated soil.

PubMed

Wan, Xiaoming; Lei, Mei; Chen, Tongbin; Yang, Junxing

2017-02-01

Intercropping technology provides income for owners of contaminated soil without increasing environmental risk. Therefore, intercropping of arsenic (As) hyperaccumulator Pteris vittata L. with economic crops is now widely utilized in slightly or moderately As-contaminated farmlands. However, the mechanisms for As mobilization and absorption within the intercropping system are still unclear. To clarify As mobilization and absorption within an intercropping system, portable X-ray fluorescence spectrometry and sequential extraction were utilized to detect the spatial distribution and speciation of As in an intercropped system of P. vittata and cash crop mulberry (Morus alba L.). Compared with the P. vittata monoculture, P. vittata intercropping had higher As concentration, which may have been caused by the efficient exploitation of a greater As source in soil. Compared with the M. alba monoculture, M. alba intercropping had lower As concentration, which may have been caused by the As depletion by P. vittata roots. Spatial distribution of As in the soil indicated a "valley" around the P. vittata roots in both monocultured and intercropped systems, implying that As was depleted around the P. vittata roots. Continuous As extraction confirmed that both P. vittata monoculture and P. vittata and M. alba intercropping can efficiently control the risk of As soil contamination. Moreover, the properties of M. alba leaves were further studied. Mulberry leaves in the intercropping system satisfied the national feed standards. Therefore, intercropping presents a safe utilization mode for As-contaminated soil and can increase the income from silkworm-rearing M. alba leaves, without extra environmental risk. Copyright © 2016. Published by Elsevier B.V.

3D-printed lab-on-valve for fluorescent determination of cadmium and lead in water.

PubMed

Mattio, Elodie; Robert-Peillard, Fabien; Vassalo, Laurent; Branger, Catherine; Margaillan, André; Brach-Papa, Christophe; Knoery, Joël; Boudenne, Jean-Luc; Coulomb, Bruno

2018-06-01

In recent years, the development of 3D printing in flow analysis has allowed the creation of new systems with various applications. Up to now, 3D printing was mainly used for the manufacture of small units such as flow detection cells, preconcentration units or mixing systems. In the present study, a new 3D printed lab-on-valve system was developed to selectively quantify lead and cadmium in water. Different technologies were compared for lab-on-valve 3D printing. Printed test units have shown that stereolithography or digital light processing are satisfactory techniques for creating complex lab-on-valve units. The lab-on-valve system was composed of two columns, eight peripheral ports and a central port, and a coil integrating baffles to increase mixing possibilities. A selective extraction of lead was first carried out by TrisKem Pb™ Resin column. Then, cadmium not retained on the first column was extracted on a second column of Amberlite® IR 120 resin. In a following step, lead and cadmium were eluted with ammonium oxalate and potassium iodide, respectively. Finally, the two metals were sequentially detected by the same Rhod-5N™ fluorescent reagent. This 3D printed lab-on-valve flow system allowed us to quantify lead and cadmium with a linear response from 0.2 to 15 µg L -1 and detection limits of 0.17 and 0.20 µg L -1 for lead and cadmium, respectively, which seems adapted for natural water analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

Microwave Ablation: Comparison of Simultaneous and Sequential Activation of Multiple Antennas in Liver Model Systems.

PubMed

Harari, Colin M; Magagna, Michelle; Bedoya, Mariajose; Lee, Fred T; Lubner, Meghan G; Hinshaw, J Louis; Ziemlewicz, Timothy; Brace, Christopher L

2016-01-01

To compare microwave ablation zones created by using sequential or simultaneous power delivery in ex vivo and in vivo liver tissue. All procedures were approved by the institutional animal care and use committee. Microwave ablations were performed in both ex vivo and in vivo liver models with a 2.45-GHz system capable of powering up to three antennas simultaneously. Two- and three-antenna arrays were evaluated in each model. Sequential and simultaneous ablations were created by delivering power (50 W ex vivo, 65 W in vivo) for 5 minutes per antenna (10 and 15 minutes total ablation time for sequential ablations, 5 minutes for simultaneous ablations). Thirty-two ablations were performed in ex vivo bovine livers (eight per group) and 28 in the livers of eight swine in vivo (seven per group). Ablation zone size and circularity metrics were determined from ablations excised postmortem. Mixed effects modeling was used to evaluate the influence of power delivery, number of antennas, and tissue type. On average, ablations created by using the simultaneous power delivery technique were larger than those with the sequential technique (P < .05). Simultaneous ablations were also more circular than sequential ablations (P = .0001). Larger and more circular ablations were achieved with three antennas compared with two antennas (P < .05). Ablations were generally smaller in vivo compared with ex vivo. The use of multiple antennas and simultaneous power delivery creates larger, more confluent ablations with greater temperatures than those created with sequential power delivery. © RSNA, 2015.

Analytical Method for Determining Tetrazene in Water.

DTIC Science & Technology

1987-12-01

8217-decanesulfonic acid sodium salt. The mobile phase pH was adjusted to 3 with glacial acetic acid. The modified mobile phase was optimal for separating of...modified with sodium tartrate, gave a well-defined reduction wave at the dropping mercury electrode. The height of the reduction wave was proportional to...anitmony trisulphide, nitrocellulose, PETN, powdered aluminum and calcium silicide . The primer samples were sequentially extracted, first with

Soil Phosphorus Fractionation during Forest Development on Landslide Scars in the Luquillo Mountains, Puerto Rico.

Treesearch

Jacqueline Frizano; Arthur H. Johnson; David R. Vann; Frederick N. Scatena

2002-01-01

Mineral soils from a chronosequence of landslide scars ranging in age from 1 to more than 55 years in a subtropical montane rain forest of eastern Puerto Rico were used to determine the rate at which labile P capital recovers during primary succession. Nine organic and inorganic soil P fractions were measured using the Hedley sequential extraction procedure. Deep soil...

Fractionation of heavy metals in liquefied chromated copper arsenate (CCA)-treated wood sludge using a modified BCR-sequential extraction procedure

Treesearch

Hui Pan; Chung-Yun Hse; Robert Gambrell; Todd F. Shupe

2009-01-01

Chromated copper arsenate (CCA)-treated wood was liquefied with polyethylene glycol/glycerin and sulfuric acid. After liquefaction, most CCA metals (98% As, 92% Cr, and 83% Cu) were removed from liquefied CCA-treated wood by precipitation with calcium hydroxide. The original CCA-treated wood and liquefied CCA-treated wood sludge were fractionated by a modified...

ANAEROBIC AND AEROBIC TREATMENT OF CHLORINATED ALIPHATIC COMPOUNDS

EPA Science Inventory

Biological degradation of 12 chlorinated aliphatic compounds (CACs) was assessed in bench-top reactors and in serum bottle tests. Three continuously mixed daily batch-fed reactor systems were evaluated: anaerobic, aerobic, and sequential-anaerobic-aerobic (sequential). Glucose,...

Physics-based, Bayesian sequential detection method and system for radioactive contraband

DOEpatents

Candy, James V; Axelrod, Michael C; Breitfeller, Eric F; Chambers, David H; Guidry, Brian L; Manatt, Douglas R; Meyer, Alan W; Sale, Kenneth E

2014-03-18

A distributed sequential method and system for detecting and identifying radioactive contraband from highly uncertain (noisy) low-count, radionuclide measurements, i.e. an event mode sequence (EMS), using a statistical approach based on Bayesian inference and physics-model-based signal processing based on the representation of a radionuclide as a monoenergetic decomposition of monoenergetic sources. For a given photon event of the EMS, the appropriate monoenergy processing channel is determined using a confidence interval condition-based discriminator for the energy amplitude and interarrival time and parameter estimates are used to update a measured probability density function estimate for a target radionuclide. A sequential likelihood ratio test is then used to determine one of two threshold conditions signifying that the EMS is either identified as the target radionuclide or not, and if not, then repeating the process for the next sequential photon event of the EMS until one of the two threshold conditions is satisfied.

Determination, speciation and distribution of mercury in soil in the surroundings of a former chlor-alkali plant: assessment of sequential extraction procedure and analytical technique

PubMed Central

2013-01-01

Background The paper presents the evaluation of soil contamination with total, water-available, mobile, semi-mobile and non-mobile Hg fractions in the surroundings of a former chlor-alkali plant in connection with several chemical soil characteristics. Principal Component Analysis and Cluster Analysis were used to evaluate the chemical composition variability of soil and factors influencing the fate of Hg in such areas. The sequential extraction EPA 3200-Method and the determination technique based on capacitively coupled microplasma optical emission spectrometry were checked. Results A case study was conducted in the Turda town, Romania. The results revealed a high contamination with Hg in the area of the former chlor-alkali plant and waste landfills, where soils were categorized as hazardous waste. The weight of the Hg fractions decreased in the order semi-mobile > non-mobile > mobile > water leachable. Principal Component Analysis revealed 7 factors describing chemical composition variability of soil, of which 3 attributed to Hg species. Total Hg, semi-mobile, non-mobile and mobile fractions were observed to have a strong influence, while the water leachable fraction a weak influence. The two-dimensional plot of PCs highlighted 3 groups of sites according to the Hg contamination factor. The statistical approach has shown that the Hg fate in soil is dependent on pH, content of organic matter, Ca, Fe, Mn, Cu and SO42- rather than natural components, such as aluminosilicates. Cluster analysis of soil characteristics revealed 3 clusters, one of which including Hg species. Soil contamination with Cu as sulfate and Zn as nitrate was also observed. Conclusions The approach based on speciation and statistical interpretation of data developed in this study could be useful in the investigation of other chlor-alkali contaminated areas. According to the Bland and Altman test the 3-step sequential extraction scheme is suitable for Hg speciation in soil, while the used determination method of Hg is appropriate. PMID:24252185

Expert system for online surveillance of nuclear reactor coolant pumps

DOEpatents

Gross, Kenny C.; Singer, Ralph M.; Humenik, Keith E.

1993-01-01

An expert system for online surveillance of nuclear reactor coolant pumps. This system provides a means for early detection of pump or sensor degradation. Degradation is determined through the use of a statistical analysis technique, sequential probability ratio test, applied to information from several sensors which are responsive to differing physical parameters. The results of sequential testing of the data provide the operator with an early warning of possible sensor or pump failure.

Fast-responding liquid crystal light-valve technology for color-sequential display applications

NASA Astrophysics Data System (ADS)

Janssen, Peter J.; Konovalov, Victor A.; Muravski, Anatoli A.; Yakovenko, Sergei Y.

1996-04-01

A color sequential projection system has some distinct advantages over conventional systems which make it uniquely suitable for consumer TV as well as high performance professional applications such as computer monitors and electronic cinema. A fast responding light-valve is, clearly, essential for a good performing system. Response speed of transmissive LC lightvalves has been marginal thus far for good color rendition. Recently, Sevchenko Institute has made some very fast reflective LC cells which were evaluated at Philips Labs. These devices showed sub millisecond-large signal-response times, even at room temperature, and produced good color in a projector emulation testbed. In our presentation we describe our highly efficient color sequential projector and demonstrate its operation on video tape. Next we discuss light-valve requirements and reflective light-valve test results.

Sequentially reweighted TV minimization for CT metal artifact reduction.

PubMed

Zhang, Xiaomeng; Xing, Lei

2013-07-01

Metal artifact reduction has long been an important topic in x-ray CT image reconstruction. In this work, the authors propose an iterative method that sequentially minimizes a reweighted total variation (TV) of the image and produces substantially artifact-reduced reconstructions. A sequentially reweighted TV minimization algorithm is proposed to fully exploit the sparseness of image gradients (IG). The authors first formulate a constrained optimization model that minimizes a weighted TV of the image, subject to the constraint that the estimated projection data are within a specified tolerance of the available projection measurements, with image non-negativity enforced. The authors then solve a sequence of weighted TV minimization problems where weights used for the next iteration are computed from the current solution. Using the complete projection data, the algorithm first reconstructs an image from which a binary metal image can be extracted. Forward projection of the binary image identifies metal traces in the projection space. The metal-free background image is then reconstructed from the metal-trace-excluded projection data by employing a different set of weights. Each minimization problem is solved using a gradient method that alternates projection-onto-convex-sets and steepest descent. A series of simulation and experimental studies are performed to evaluate the proposed approach. Our study shows that the sequentially reweighted scheme, by altering a single parameter in the weighting function, flexibly controls the sparsity of the IG and reconstructs artifacts-free images in a two-stage process. It successfully produces images with significantly reduced streak artifacts, suppressed noise and well-preserved contrast and edge properties. The sequentially reweighed TV minimization provides a systematic approach for suppressing CT metal artifacts. The technique can also be generalized to other "missing data" problems in CT image reconstruction.

A computer-aided diagnosis system to detect pathologies in temporal subtraction images of chest radiographs

NASA Astrophysics Data System (ADS)

Looper, Jared; Harrison, Melanie; Armato, Samuel G.

2016-03-01

Radiologists often compare sequential radiographs to identify areas of pathologic change; however, this process is prone to error, as human anatomy can obscure the regions of change, causing the radiologists to overlook pathology. Temporal subtraction (TS) images can provide enhanced visualization of regions of change in sequential radiographs and allow radiologists to better detect areas of change in radiographs. Not all areas of change shown in TS images, however, are actual pathology. The purpose of this study was to create a computer-aided diagnostic (CAD) system that identifies which regions of change are caused by pathology and which are caused by misregistration of the radiographs used to create the TS image. The dataset used in this study contained 120 images with 74 pathologic regions on 54 images outlined by an experienced radiologist. High and low ("light" and "dark") gray-level candidate regions were extracted from the images using gray-level thresholding. Then, sampling techniques were used to address the class imbalance problem between "true" and "false" candidate regions. Next, the datasets of light candidate regions, dark candidate regions, and the combined set of light and dark candidate regions were used as training and testing data for classifiers by using five-fold cross validation. Of the classifiers tested (support vector machines, discriminant analyses, logistic regression, and k-nearest neighbors), the support vector machine on the combined candidates using synthetic minority oversampling technique (SMOTE) performed best with an area under the receiver operating characteristic curve value of 0.85, a sensitivity of 85%, and a specificity of 84%.

Modeling the evolution of a ramp-flat-ramp thrust system: A geological application of DynEarthSol2D

NASA Astrophysics Data System (ADS)

Feng, L.; Choi, E.; Bartholomew, M. J.

2013-12-01

DynEarthSol2D (available at http://bitbucket.org/tan2/dynearthsol2) is a robust, adaptive, two-dimensional finite element code that solves the momentum balance and the heat equation in Lagrangian form using unstructured meshes. Verified in a number of benchmark problems, this solver uses contingent mesh adaptivity in places where shear strain is focused (localization) and a conservative mapping assisted by marker particles to preserve phase and facies boundaries during remeshing. We apply this cutting-edge geodynamic modeling tool to the evolution of a thrust fault with a ramp-flat-ramp geometry. The overall geometry of the fault is constrained by observations in the northern part of the southern Appalachian fold and thrust belt. Brittle crust is treated as a Mohr-Coulomb plastic material. The thrust fault is a zone of a finite thickness but has a lower cohesion and friction angle than its surrounding rocks. When an intervening flat separates two distinct sequential ramps crossing different stratigraphic intervals, the thrust system will experience more complex deformations than those from a single thrust fault ramp. The resultant deformations associated with sequential ramps would exhibit a spectrum of styles, of which two end members correspond to ';overprinting' and ';interference'. Reproducing these end-member styles as well as intermediate ones, our models show that the relative importance of overprinting versus interference is a sensitive function of initial fault geometry and hanging wall displacement. We further present stress and strain histories extracted from the models. If clearly distinguishable, they will guide the interpretation of field observations on thrust faults.

Effect of Mouriri pusa extracts on experimentally induced gastric lesions in rodents: role of endogenous sulfhydryls compounds and nitric oxide in gastroprotection.

PubMed

Andreo, Marcio Adriano; Ballesteros, Kátia Verônica Rodríguez; Hiruma-Lima, Clélia Akiko; Machado da Rocha, Lúcia Regina; Souza Brito, Alba Regina Monteiro; Vilegas, Wagner

2006-10-11

Several plants are used in folk medicine to treat gastrointestinal disorders. Mouriri pusa Gardn. (Melastomataceae) is a medicinal plant commonly used in the central region of Brazil against gastric ulcer. Two organic extracts methanolic (MeOH) and dichloromethane (DCM) obtained by sequential extraction from the leaves of Mouriri pusa were evaluated for their ability to protect the gastric mucosa against injuries caused by necrotizing agents (0.3M HCl/60% EtOH, absolute ethanol, non-steroidal anti-inflammatory drug, stress and pylorus ligature) in mice and rats. The best results were obtained after pretreatment with MeOH extract whereas the DCM extract did not show the same significant antiulcerogenic activity. No acute toxicity was observed in animals treated with 5 g/kg, p.o. of MeOH extract. The mechanism involving the antiulcerogenic action of MeOH extract seemed to be related to NO generation and also suggested the effective participation of endogenous sulfhydryl group in the gastroprotective action. Phytochemical investigation of the MeOH extract of Mouriri pusa yielded tannins, flavonoids and (-)-epicatechin. The presence of these phenolic compounds probably would explain the antiulcerogenic effect of the polar extract of Mouriri pusa leaves.

Patterns and Sequences: Interactive Exploration of Clickstreams to Understand Common Visitor Paths.

PubMed

Liu, Zhicheng; Wang, Yang; Dontcheva, Mira; Hoffman, Matthew; Walker, Seth; Wilson, Alan

2017-01-01

Modern web clickstream data consists of long, high-dimensional sequences of multivariate events, making it difficult to analyze. Following the overarching principle that the visual interface should provide information about the dataset at multiple levels of granularity and allow users to easily navigate across these levels, we identify four levels of granularity in clickstream analysis: patterns, segments, sequences and events. We present an analytic pipeline consisting of three stages: pattern mining, pattern pruning and coordinated exploration between patterns and sequences. Based on this approach, we discuss properties of maximal sequential patterns, propose methods to reduce the number of patterns and describe design considerations for visualizing the extracted sequential patterns and the corresponding raw sequences. We demonstrate the viability of our approach through an analysis scenario and discuss the strengths and limitations of the methods based on user feedback.

Research on aviation unsafe incidents classification with improved TF-IDF algorithm

NASA Astrophysics Data System (ADS)

Wang, Yanhua; Zhang, Zhiyuan; Huo, Weigang

2016-05-01

The text content of Aviation Safety Confidential Reports contains a large number of valuable information. Term frequency-inverse document frequency algorithm is commonly used in text analysis, but it does not take into account the sequential relationship of the words in the text and its role in semantic expression. According to the seven category labels of civil aviation unsafe incidents, aiming at solving the problems of TF-IDF algorithm, this paper improved TF-IDF algorithm based on co-occurrence network; established feature words extraction and words sequential relations for classified incidents. Aviation domain lexicon was used to improve the accuracy rate of classification. Feature words network model was designed for multi-documents unsafe incidents classification, and it was used in the experiment. Finally, the classification accuracy of improved algorithm was verified by the experiments.

IgG and IgM anti-snRNP reactivity in sequentially obtained serum samples from patients with connective tissue diseases.

PubMed Central

Nyman, U; Lundberg, I; Hedfors, E; Wahren, M; Pettersson, I

1992-01-01

Sequentially obtained serum samples from 30 patients with connective tissue disease positive for antibody to ribonucleoprotein (RNP) were examined to determine the specificities of IgG and IgM antibodies to snRNP during the disease course using immunoblotting of nuclear extracts. The antibody patterns were correlated with disease activity. The patterns of antibody to snRNP of individual patients were mainly stable during the study but changes in levels of antibody to snRNP were seen corresponding to changes in clinical activity. These results indicate that increased reactivity of serum IgM antibodies against the B/B' proteins seems to precede a clinically evident exacerbation of disease whereas IgG antibody reactivity to the 70 K protein peaks at the time of a disease flare. Images PMID:1485812

Radionuclide studies of chronic schistosomal uropathy

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

Lamki, L.M.; Lamki, N.

1981-08-01

Fifty patients with chronic urinary tract schistosomiasis were studied with /sup 99m/Tc-DTPA. All had a flow study, sequential analog imaging, and digital imaging for 25-35 minutes (20-sec. frames). Time-activity curves (DTPA renograms) were extracted; 12 patients had /sup 131/I-Hippuran probe renograms as well. Renal changes included diminished perfusion and structural abnormalities ranging from minor calyceal dilatation to overt hydronephrosis. Ureteral changes included dilatation, tortuosity, and kinking. Marked distortion of the ureterovesical tunction was seen in some patients due to periureteral and perivesicular fibrosis, which is a major factor in upper urinary tract damage. Renograms showed varying obstruction and parenchymal damage.more » Nuclear medicine complements excretory urography and is sometimes preferable for visualization of the ureters. After the initial urogram, sequential DTPA scanning and renography are sufficient for follow-up.« less

Production of Recombinant Trichoderma reesei Cellobiohydrolase II in a New Expression System Based on Wickerhamomyces anomalus

PubMed Central

Díaz-Rincón, Dennis J.; Duque, Ivonne; Osorio, Erika; Rodríguez-López, Alexander; Espejo-Mojica, Angela; Parra-Giraldo, Claudia M.

2017-01-01

Cellulase is a family of at least three groups of enzymes that participate in the sequential hydrolysis of cellulose. Recombinant expression of cellulases might allow reducing their production times and increasing the low proteins concentrations obtained with filamentous fungi. In this study, we describe the production of Trichoderma reesei cellobiohydrolase II (CBHII) in a native strain of Wickerhamomyces anomalus. Recombinant CBHII was expressed in W. anomalus 54-A reaching enzyme activity values of up to 14.5 U L−1. The enzyme extract showed optimum pH and temperature of 5.0–6.0 and 40°C, respectively. Enzyme kinetic parameters (KM of 2.73 mM and Vmax of 23.1 µM min−1) were between the ranges of values reported for other CBHII enzymes. Finally, the results showed that an enzymatic extract of W. anomalus 54-A carrying the recombinant T. reesei CBHII allows production of reducing sugars similar to that of a crude extract from cellulolytic fungi. These results show the first report on the use of W. anomalus as a host to produce recombinant proteins. In addition, recombinant T. reesei CBHII enzyme could potentially be used in the degradation of lignocellulosic residues to produce bioethanol, based on its pH and temperature activity profile. PMID:28951785

Eyewitness confidence in simultaneous and sequential lineups: a criterion shift account for sequential mistaken identification overconfidence.

PubMed

Dobolyi, David G; Dodson, Chad S

2013-12-01

Confidence judgments for eyewitness identifications play an integral role in determining guilt during legal proceedings. Past research has shown that confidence in positive identifications is strongly associated with accuracy. Using a standard lineup recognition paradigm, we investigated accuracy using signal detection and ROC analyses, along with the tendency to choose a face with both simultaneous and sequential lineups. We replicated past findings of reduced rates of choosing with sequential as compared to simultaneous lineups, but notably found an accuracy advantage in favor of simultaneous lineups. Moreover, our analysis of the confidence-accuracy relationship revealed two key findings. First, we observed a sequential mistaken identification overconfidence effect: despite an overall reduction in false alarms, confidence for false alarms that did occur was higher with sequential lineups than with simultaneous lineups, with no differences in confidence for correct identifications. This sequential mistaken identification overconfidence effect is an expected byproduct of the use of a more conservative identification criterion with sequential than with simultaneous lineups. Second, we found a steady drop in confidence for mistaken identifications (i.e., foil identifications and false alarms) from the first to the last face in sequential lineups, whereas confidence in and accuracy of correct identifications remained relatively stable. Overall, we observed that sequential lineups are both less accurate and produce higher confidence false identifications than do simultaneous lineups. Given the increasing prominence of sequential lineups in our legal system, our data argue for increased scrutiny and possibly a wholesale reevaluation of this lineup format. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Improved solution accuracy for TDRSS-based TOPEX/Poseidon orbit determination

NASA Technical Reports Server (NTRS)

Doll, C. E.; Mistretta, G. D.; Hart, R. C.; Oza, D. H.; Bolvin, D. T.; Cox, C. M.; Nemesure, M.; Niklewski, D. J.; Samii, M. V.

1994-01-01

Orbit determination results are obtained by the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) using a batch-least-squares estimator available in the Goddard Trajectory Determination System (GTDS) and an extended Kalman filter estimation system to process Tracking and Data Relay Satellite (TDRS) System (TDRSS) measurements. GTDS is the operational orbit determination system used by the FDD in support of the Ocean Topography Experiment (TOPEX)/Poseidon spacecraft navigation and health and safety operations. The extended Kalman filter was implemented in an orbit determination analysis prototype system, closely related to the Real-Time Orbit Determination System/Enhanced (RTOD/E) system. In addition, the Precision Orbit Determination (POD) team within the GSFC Space Geodesy Branch generated an independent set of high-accuracy trajectories to support the TOPEX/Poseidon scientific data. These latter solutions use the geodynamics (GEODYN) orbit determination system with laser ranging and Doppler Orbitography and Radiopositioning integrated by satellite (DORIS) tracking measurements. The TOPEX/Poseidon trajectories were estimated for November 7 through November 11, 1992, the timeframe under study. Independent assessments were made of the consistencies of solutions produced by the batch and sequential methods. The batch-least-squares solutions were assessed based on the solution residuals, while the sequential solutions were assessed based on primarily the estimated covariances. The batch-least-squares and sequential orbit solutions were compared with the definitive POD orbit solutions. The solution differences were generally less than 2 meters for the batch-least-squares and less than 13 meters for the sequential estimation solutions. After the sequential estimation solutions were processed with a smoother algorithm, position differences with POD orbit solutions of less than 7 meters were obtained. The differences among the POD, GTDS, and filter/smoother solutions can be traced to differences in modeling and tracking data types, which are being analyzed in detail.

SSME propellant path leak detection real-time

NASA Technical Reports Server (NTRS)

Crawford, R. A.; Smith, L. M.

1994-01-01

Included are four documents that outline the technical aspects of the research performed on NASA Grant NAG8-140: 'A System for Sequential Step Detection with Application to Video Image Processing'; 'Leak Detection from the SSME Using Sequential Image Processing'; 'Digital Image Processor Specifications for Real-Time SSME Leak Detection'; and 'A Color Change Detection System for Video Signals with Applications to Spectral Analysis of Rocket Engine Plumes'.

Feasibility Study of a Generalized Framework for Developing Computer-Aided Detection Systems-a New Paradigm.

PubMed

Nemoto, Mitsutaka; Hayashi, Naoto; Hanaoka, Shouhei; Nomura, Yukihiro; Miki, Soichiro; Yoshikawa, Takeharu

2017-10-01

We propose a generalized framework for developing computer-aided detection (CADe) systems whose characteristics depend only on those of the training dataset. The purpose of this study is to show the feasibility of the framework. Two different CADe systems were experimentally developed by a prototype of the framework, but with different training datasets. The CADe systems include four components; preprocessing, candidate area extraction, candidate detection, and candidate classification. Four pretrained algorithms with dedicated optimization/setting methods corresponding to the respective components were prepared in advance. The pretrained algorithms were sequentially trained in the order of processing of the components. In this study, two different datasets, brain MRA with cerebral aneurysms and chest CT with lung nodules, were collected to develop two different types of CADe systems in the framework. The performances of the developed CADe systems were evaluated by threefold cross-validation. The CADe systems for detecting cerebral aneurysms in brain MRAs and for detecting lung nodules in chest CTs were successfully developed using the respective datasets. The framework was shown to be feasible by the successful development of the two different types of CADe systems. The feasibility of this framework shows promise for a new paradigm in the development of CADe systems: development of CADe systems without any lesion specific algorithm designing.

Use of partial dissolution techniques in geochemical exploration

USGS Publications Warehouse

Chao, T.T.

1984-01-01

Application of partial dissolution techniques to geochemical exploration has advanced from an early empirical approach to an approach based on sound geochemical principles. This advance assures a prominent future position for the use of these techniques in geochemical exploration for concealed mineral deposits. Partial dissolution techniques are classified as single dissolution or sequential multiple dissolution depending on the number of steps taken in the procedure, or as "nonselective" extraction and as "selective" extraction in terms of the relative specificity of the extraction. The choice of dissolution techniques for use in geochemical exploration is dictated by the geology of the area, the type and degree of weathering, and the expected chemical forms of the ore and of the pathfinding elements. Case histories have illustrated many instances where partial dissolution techniques exhibit advantages over conventional methods of chemical analysis used in geochemical exploration. ?? 1984.

Validation of a method for simultaneous determination of nitroimidazoles, benzimidazoles and chloramphenicols in swine tissues by ultra-high performance liquid chromatography-tandem mass spectrometry.

PubMed

Xia, Xi; Wang, Yuanyuan; Wang, Xia; Li, Yun; Zhong, Feng; Li, Xiaowei; Huang, Yaoling; Ding, Shuangyang; Shen, Jianzhong

2013-05-31

This paper presents a sensitive and confirmatory multi-residue method for the analysis of 23 veterinary drugs and metabolites belonging to three classes (nitroimidazoles, benzimidazoles, and chloramphenicols) in porcine muscle, liver, and kidney. After extracted with ethyl acetate and basic ethyl acetate sequentially, the crude extracts were defatted with hexane and further purified using Oasis MCX solid-phase extraction cartridges. Rapid determination was carried out by ultra-high performance liquid chromatography-electrospray ionization tandem mass spectrometry. Data acquisition was performed under positive and negative mode simultaneously. Recoveries based on matrix-matched calibrations for meat, liver, and kidney ranged from 50.6 to 108.1%. The method quantification limits were in the range of 3-100ng/kg. Copyright © 2012 Elsevier B.V. All rights reserved.

Microwave Ablation: Comparison of Simultaneous and Sequential Activation of Multiple Antennas in Liver Model Systems

PubMed Central

Harari, Colin M.; Magagna, Michelle; Bedoya, Mariajose; Lee, Fred T.; Lubner, Meghan G.; Hinshaw, J. Louis; Ziemlewicz, Timothy

2016-01-01

Purpose To compare microwave ablation zones created by using sequential or simultaneous power delivery in ex vivo and in vivo liver tissue. Materials and Methods All procedures were approved by the institutional animal care and use committee. Microwave ablations were performed in both ex vivo and in vivo liver models with a 2.45-GHz system capable of powering up to three antennas simultaneously. Two- and three-antenna arrays were evaluated in each model. Sequential and simultaneous ablations were created by delivering power (50 W ex vivo, 65 W in vivo) for 5 minutes per antenna (10 and 15 minutes total ablation time for sequential ablations, 5 minutes for simultaneous ablations). Thirty-two ablations were performed in ex vivo bovine livers (eight per group) and 28 in the livers of eight swine in vivo (seven per group). Ablation zone size and circularity metrics were determined from ablations excised postmortem. Mixed effects modeling was used to evaluate the influence of power delivery, number of antennas, and tissue type. Results On average, ablations created by using the simultaneous power delivery technique were larger than those with the sequential technique (P < .05). Simultaneous ablations were also more circular than sequential ablations (P = .0001). Larger and more circular ablations were achieved with three antennas compared with two antennas (P < .05). Ablations were generally smaller in vivo compared with ex vivo. Conclusion The use of multiple antennas and simultaneous power delivery creates larger, more confluent ablations with greater temperatures than those created with sequential power delivery. © RSNA, 2015 PMID:26133361

Feature Selection based on Machine Learning in MRIs for Hippocampal Segmentation

NASA Astrophysics Data System (ADS)

Tangaro, Sabina; Amoroso, Nicola; Brescia, Massimo; Cavuoti, Stefano; Chincarini, Andrea; Errico, Rosangela; Paolo, Inglese; Longo, Giuseppe; Maglietta, Rosalia; Tateo, Andrea; Riccio, Giuseppe; Bellotti, Roberto

2015-01-01

Neurodegenerative diseases are frequently associated with structural changes in the brain. Magnetic resonance imaging (MRI) scans can show these variations and therefore can be used as a supportive feature for a number of neurodegenerative diseases. The hippocampus has been known to be a biomarker for Alzheimer disease and other neurological and psychiatric diseases. However, it requires accurate, robust, and reproducible delineation of hippocampal structures. Fully automatic methods are usually the voxel based approach; for each voxel a number of local features were calculated. In this paper, we compared four different techniques for feature selection from a set of 315 features extracted for each voxel: (i) filter method based on the Kolmogorov-Smirnov test; two wrapper methods, respectively, (ii) sequential forward selection and (iii) sequential backward elimination; and (iv) embedded method based on the Random Forest Classifier on a set of 10 T1-weighted brain MRIs and tested on an independent set of 25 subjects. The resulting segmentations were compared with manual reference labelling. By using only 23 feature for each voxel (sequential backward elimination) we obtained comparable state-of-the-art performances with respect to the standard tool FreeSurfer.

Geochemical Transformation of Cadmium (Cd) from Creek to Paddy Fields in W Thailand

NASA Astrophysics Data System (ADS)

Kosolsaksakul, Peerapat; Graham, Margaret; Farmer, John

2013-04-01

Extensive Cd contamination of paddy soils in Tak Province, western Thailand, a consequence of Zn mining activities, was first established in 2005 and medical studies showed that the health of local communities was being impaired. Mae Tao, Tak Province, comprising many paddy fields and irrigation canals, has been selected for this study of the geochemical transformation of Cd from the contamination source in the mountainous region to the east of the study site through the community irrigation system to the paddy soils. The aim of this research is to (i) investigate the geochemical transformation of Cd as it is transported from the main irrigation creek through the canals and to the paddy fields, (ii) assess the availability of Cd to rice plants, which may be affected by both chemical and physical factors, and (iii) trial some practical treatments to minimise Cd concentrations in rice grains. Soils, irrigation canal sediments and water samples were collected during the dry season and at the onset of the rainy season. Rice samples were collected at harvesting time and samples of soil fertiliser were also obtained. Water samples were filtered, ultrafiltered and analysed by ICP-MS whilst sub-samples of dried, ground soils and sediments were first subjected to micro-wave assisted acid digestion (modified US EPA method 3052). XRD and SEM-EDX methods were used for mineralogical characterisation and selective chemical extractions have assisted in the characterisation of solid phase Cd associations. Soil Cd concentrations were in the range 2.5-87.6 µg g-1, with higher values being obtained for fields furthest from the main creek. Although current irrigation water Cd inputs are low (mean 1.9 μg L-1; flood period), high loads of suspended particles still contribute additional Cd (4.2-9.8 µg L-1) to the paddy fields. For bioavailability assessment by a 3-step BCR sequential extraction, 70-90% Cd was in the exchangeable; HOAc-extractable fraction. That indicated that most of the Cd was in water soluble, exchangeable and carbonate-bound forms. For the fields with highest Cd concentration, SEM-EDX analysis identified two forms of Cd, i.e. Cd-Clay and Cd-CaCO3, in good agreement with the sequential extraction data. The predominance of easily extractable forms in the paddy field soils suggests that Cd may be readily absorbed by the rice plants. After harvesting, the Cd concentration in rice grains ranged from 0.05-4.0 µg g-1 and the concentration trends across the group of 18 fields matched well with the soil Cd data. Rice from nine out of the 18 fields contained Cd at greater than the safe level of 0.4 µg g-1.

Basketball lay-up - foot loading characteristics and the number of trials necessary to obtain stable plantar pressure variables.

PubMed

Chua, YaoHui K; Quek, Raymond K K; Kong, Pui W

2017-03-01

This study aimed (1) to profile the plantar loading characteristics when performing the basketball lay-up in a realistic setting and (2) to determine the number of trials necessary to establish a stable mean for plantar loading variables during the lay-up. Thirteen university male basketball players [age: 23.0 (1.4) years, height: 1.75 (0.05) m, mass: 68.4 (8.6) kg] performed ten successful basketball lay-ups from a stationary position. Plantar loading variables were recorded using the Novel Pedar-X in-shoe system. Loading variables including peak force, peak pressure, and pressure-time integral were extracted from eight foot regions. Performance stability of plantar loading variables during the take-off and landing steps were assessed using the sequential averaging technique and intra-class correlation coefficient (ICC). High plantar loadings were experienced at the heel during the take-off steps, and both the heel and forefoot regions upon landing. The sequential estimation technique revealed a five-eight trial range to achieve a stable mean across all plantar loading variables, whereas ICC analysis was insensitive to inter-trial differences of repeated lay-up performances. Future studies and performance evaluation protocols on plantar loading during basketball lay-ups should include at least eight trials to ensure that the measurements obtained are sufficiently stable.

High-mobility capacitively-induced two-dimensional electrons in a lateral superlattice potential

DOE PAGES

Lu, Tzu -Ming; Laroche, Dominique; Huang, S. -H.; ...

2016-01-01

In the presence of a lateral periodic potential modulation, two-dimensional electrons may exhibit interesting phenomena, such as a graphene-like energy-momentum dispersion, Bloch oscillations, or the Hofstadter butterfly band structure. To create a sufficiently strong potential modulation using conventional semiconductor heterostructures, aggressive device processing is often required, unfortunately resulting in strong disorder that masks the sought-after effects. Here, we report a novel fabrication process flow for imposing a strong lateral potential modulation onto a capacitively induced two-dimensional electron system, while preserving the host material quality. Using this process flow, the electron density in a patterned Si/SiGe heterostructure can be tuned overmore » a wide range, from 4.4 × 10 10 cm –2 to 1.8 × 10 11 cm –2, with a peak mobility of 6.4 × 10 5 cm 2/V·s. The wide density tunability and high electron mobility allow us to observe sequential emergence of commensurability oscillations as the density, the mobility, and in turn the mean free path, increase. Magnetic-field-periodic quantum oscillations associated with various closed orbits also emerge sequentially with increasing density. We show that, from the density dependence of the quantum oscillations, one can directly extract the steepness of the imposed superlattice potential. Lastly, this result is then compared to a conventional lateral superlattice model potential.« less

On the origin of reproducible sequential activity in neural circuits

NASA Astrophysics Data System (ADS)

Afraimovich, V. S.; Zhigulin, V. P.; Rabinovich, M. I.

2004-12-01

Robustness and reproducibility of sequential spatio-temporal responses is an essential feature of many neural circuits in sensory and motor systems of animals. The most common mathematical images of dynamical regimes in neural systems are fixed points, limit cycles, chaotic attractors, and continuous attractors (attractive manifolds of neutrally stable fixed points). These are not suitable for the description of reproducible transient sequential neural dynamics. In this paper we present the concept of a stable heteroclinic sequence (SHS), which is not an attractor. SHS opens the way for understanding and modeling of transient sequential activity in neural circuits. We show that this new mathematical object can be used to describe robust and reproducible sequential neural dynamics. Using the framework of a generalized high-dimensional Lotka-Volterra model, that describes the dynamics of firing rates in an inhibitory network, we present analytical results on the existence of the SHS in the phase space of the network. With the help of numerical simulations we confirm its robustness in presence of noise in spite of the transient nature of the corresponding trajectories. Finally, by referring to several recent neurobiological experiments, we discuss possible applications of this new concept to several problems in neuroscience.

On the origin of reproducible sequential activity in neural circuits.

PubMed

Afraimovich, V S; Zhigulin, V P; Rabinovich, M I

2004-12-01

Robustness and reproducibility of sequential spatio-temporal responses is an essential feature of many neural circuits in sensory and motor systems of animals. The most common mathematical images of dynamical regimes in neural systems are fixed points, limit cycles, chaotic attractors, and continuous attractors (attractive manifolds of neutrally stable fixed points). These are not suitable for the description of reproducible transient sequential neural dynamics. In this paper we present the concept of a stable heteroclinic sequence (SHS), which is not an attractor. SHS opens the way for understanding and modeling of transient sequential activity in neural circuits. We show that this new mathematical object can be used to describe robust and reproducible sequential neural dynamics. Using the framework of a generalized high-dimensional Lotka-Volterra model, that describes the dynamics of firing rates in an inhibitory network, we present analytical results on the existence of the SHS in the phase space of the network. With the help of numerical simulations we confirm its robustness in presence of noise in spite of the transient nature of the corresponding trajectories. Finally, by referring to several recent neurobiological experiments, we discuss possible applications of this new concept to several problems in neuroscience.

Plant absorption of trace elements in sludge amended soils and correlation with soil chemical speciation.

PubMed

Torri, Silvana; Lavado, Raúl

2009-07-30

The aim of the present study was to investigate the relationship between Lolium perenne L. uptake of Cd, Cu, Pb, and Zn in sludge amended soils and soil availability of these elements assessed by soil sequential extraction. A greenhouse experiment was set with three representative soils of the Pampas Region, Argentina, amended with sewage sludge and sewage sludge enriched with its own incinerated ash. After the stabilization period of 60 days, half of the pots were sampled for soil analysis; the rest of the pots were sown with L. perenne and harvested 8, 12, 16 and 20 weeks after sowing, by cutting just above the soil surface. Cadmium and Pb concentrations in aerial tissues of L. perenne were below detection limits, in good agreement with the soil fractionation study. Copper and Zn concentration in the first harvest were significantly higher in the coarse textured soil compared to the fine textured soil, in contrast with soil chemical speciation. In the third harvest, there was a positive correlation between Cu and Zn concentration in aerial biomass and soil fractions usually considered of low availability. We conclude that the most available fractions obtained by soil sequential extraction did not provide the best indicator of Cu and Zn availability to L. perenne.

Immobilization of Pb, Cd, and Zn in a contaminated soil using eggshell and banana stem amendments: metal leachability and a sequential extraction study.

PubMed

Ashrafi, Mehrnaz; Mohamad, Sharifah; Yusoff, Ismail; Shahul Hamid, Fauziah

2015-01-01

Heavy-metal-contaminated soil is one of the major environmental pollution issues all over the world. In this study, two low-cost amendments, inorganic eggshell and organic banana stem, were applied to slightly alkaline soil for the purpose of in situ immobilization of Pb, Cd, and Zn. The artificially metal-contaminated soil was treated with 5% eggshell or 10% banana stem. To simulate the rainfall conditions, a metal leaching experiment for a period of 12 weeks was designed, and the total concentrations of the metals in the leachates were determined every 2 weeks. The results from the metal leaching analysis revealed that eggshell amendment generally reduced the concentrations of Pb, Cd, and Zn in the leachates, whereas banana stem amendment was effective only on the reduction of Cd concentration in the leachates. A sequential extraction analysis was carried out at the end of the experiment to find out the speciation of the heavy metals in the amended soils. Eggshell amendment notably decreased mobility of Pb, Cd, and Zn in the soil by transforming their readily available forms to less accessible fractions. Banana stem amendment also reduced exchangeable form of Cd and increased its residual form in the soil.

Determination of isoxaflutole (balance) and its metabolites in water using solid phase extraction followed by high-performance liquid chromatography with ultraviolet or mass spectrometry

USGS Publications Warehouse

Lin, Chung-Ho; Lerch, Robert N.; Thurman, E. Michael; Garrett , Harold E.; George, Milon F.

2002-01-01

Balance (isoxaflutole, IXF) belongs to a new family of herbicides referred to as isoxazoles. IXF has a very short soil half-life (<24 h), degrading to a biologically active diketonitrile (DKN) metabolite that is more polar and considerably more stable. Further degradation of the DKN metabolite produces a nonbiologically active benzoic acid (BA) metabolite. Analytical methods using solid phase extraction followed by high-performance liquid chromatography−UV (HPLC-UV) or high-performance liquid chromatography−mass spectrometry (HPLC-MS) were developed for the analysis of IXF and its metabolites in distilled deionized water and ground water samples. To successfully detect and quantify the BA metabolite by HPLC-UV from ground water samples, a sequential elution scheme was necessary. Using HPLC-UV, the mean recoveries from sequential elution of the parent and its two metabolites from fortified ground water samples ranged from 68.6 to 101.4%. For HPLC-MS, solid phase extraction of ground water samples was performed using a polystyrene divinylbenzene polymer resin. The mean HPLC-MS recoveries of the three compounds from ground water samples spiked at 0.05−2 μg/L ranged from 100.9 to 110.3%. The limits of quantitation for HPLC-UV are approximately 150 ng/L for IXF, 100 ng/L for DKN, and 250 ng/L for BA. The limit of quantitation by HPLC-MS is 50 ng/L for each compound. The methods developed in this work can be applied to determine the transport and fate of Balance in the environment.

Estimating bioaccessibility of trace elements in particles suspended in the Athabasca River using sequential extraction.

PubMed

Javed, Muhammad Babar; Shotyk, William

2018-05-10

Employing protocols developed for polar snow and ice, water samples were collected upstream, midstream and downstream of open pit bitumen mines and upgraders along the Lower Athabasca River (AR). The purpose was to: i) estimate the bioaccessibility of trace elements associated with particulate matter in the AR using sequential extraction, and ii) determine whether their forms have been measurably impacted by industrial activities. Of the trace metals known to be enriched in bitumen (V, Ni, Mo and Re), a substantial proportion of V (78-93%) and Ni (35-81%) was found in the residual fraction representing stable minerals. In contrast, Mo and Re were partitioned mainly into more reactive forms (water soluble, acid extractable, reducible and oxidisable). Comparing the non-residual fractions in upstream versus downstream sites, only water soluble Re was significantly (P = 0.005) greater downstream of industry. In respect to the potentially toxic chalcophile elements (Cu, Pb and Tl), no measurable change was observed in Cu and Pb distribution in upstream versus downstream sites. Only residual Tl was found at upstream and midstream sites, whereas a significant proportion of Tl was also present in the reducible fraction in downstream sites. Overall, a greater proportion of trace metals in the residual fraction at midstream sites appears to be due to inputs of atmospheric dust, clearly evident in microscopic images: energy dispersive spectroscopy and x-ray diffraction analyses showed that these particles were predominantly silicates, which are assumed to have limited bioaccessibility. Copyright © 2018 Elsevier Ltd. All rights reserved.

Transport of U(VI) through sediments amended with phosphate to induce in situ uranium immobilization.

PubMed

Mehta, Vrajesh S; Maillot, Fabien; Wang, Zheming; Catalano, Jeffrey G; Giammar, Daniel E

2015-02-01

Phosphate amendments can be added to U(VI)-contaminated subsurface environments to promote in situ remediation. The primary objective of this study was to evaluate the impacts of phosphate addition on the transport of U(VI) through contaminated sediments. In batch experiments using sediments (<2 mm size fraction) from a site in Rifle, Colorado, U(VI) only weakly adsorbed due to the dominance of the aqueous speciation by Ca-U(VI)-carbonate complexes. Column experiments with these sediments were performed with flow rates that correspond to a groundwater velocity of 1.1 m/day. In the absence of phosphate, the sediments took up 1.68-1.98 μg U/g of sediments when the synthetic groundwater influent contained 4 μM U(VI). When U(VI)-free influents were then introduced with and without phosphate, substantially more uranium was retained within the column when phosphate was present in the influent. Sequential extractions of sediments from the columns revealed that uranium was uniformly distributed along the length of the columns and was primarily in forms that could be extracted by ion exchange and contact with a weak acid. Laser induced fluorescence spectroscopy (LIFS) analysis along with sequential extraction results suggest adsorption as the dominant uranium uptake mechanism. The response of dissolved uranium concentrations to stopped-flow events and the comparison of experimental data with simulations from a simple reactive transport model indicated that uranium adsorption to and desorption from the sediments was not always at local equilibrium. Copyright © 2014 Elsevier Ltd. All rights reserved.

Determination of dextromethorphan in human plasma using pipette tip solid-phase extraction and gas chromatography-mass spectrometry.

PubMed

Hasegawa, Chika; Kumazawa, Takeshi; Uchigasaki, Seisaku; Lee, Xiao-Pen; Sato, Keizo; Terada, Masaru; Kurosaki, Kunihiko

2011-10-01

Dextromethorphan was extracted from human plasma samples (100 μL) using MonoTip C(18) tips, which are packed with C(18)-bonded monolithic silica gel that is attached to the inside of the tip. The samples, which contained dextromethorphan and trimeprazine as an internal standard (IS), were mixed with 200 μL of distilled water and 50 μL of 1 mol/L glycine-sodium hydroxide buffer (pH 10). The mixture was extracted to the C(18) phase of the tip by 20 sequential aspirating/dispensing cycles using a manual micropipettor. The analytes retained on the C(18) phase were then eluted with methanol by five sequential aspirating/dispensing cycles. The eluate was injected directly into a gas chromatograph and detected by a mass spectrometer with selected ion monitoring in positive electron ionization mode. An Equity-5 fused silica capillary column (30 m × 0.32 mm i.d., film thickness 0.5 μm) gave adequate separation of the dextromethorphan, IS, and impurities. The recoveries of dextromethorphan and the IS spiked into plasma were >87.4%. The regression equation for dextromethorphan showed excellent linearity from 2.5 to 320 ng/mL of plasma, and the limit of detection was 1.25 ng/mL of plasma. The intraday and interday coefficients of variation were less than 10.5% and 14.7%, respectively. The accuracy ranged from 91.9% to 107%. The validated method was successfully used to quantify the plasma concentration of dextromethorphan in a human subject after oral administration of the drug. © Springer-Verlag 2011

Cell Wall Architecture of the Elongating Maize Coleoptile1

PubMed Central

Carpita, Nicholas C.; Defernez, Marianne; Findlay, Kim; Wells, Brian; Shoue, Douglas A.; Catchpole, Gareth; Wilson, Reginald H.; McCann, Maureen C.

2001-01-01

The primary walls of grasses are composed of cellulose microfibrils, glucuronoarabinoxylans (GAXs), and mixed-linkage β-glucans, together with smaller amounts of xyloglucans, glucomannans, pectins, and a network of polyphenolic substances. Chemical imaging by Fourier transform infrared microspectroscopy revealed large differences in the distributions of many chemical species between different tissues of the maize (Zea mays) coleoptile. This was confirmed by chemical analyses of isolated outer epidermal tissues compared with mesophyll-enriched preparations. Glucomannans and esterified uronic acids were more abundant in the epidermis, whereas β-glucans were more abundant in the mesophyll cells. The localization of β-glucan was confirmed by immunocytochemistry in the electron microscope and quantitative biochemical assays. We used field emission scanning electron microscopy, infrared microspectroscopy, and biochemical characterization of sequentially extracted polymers to further characterize the cell wall architecture of the epidermis. Oxidation of the phenolic network followed by dilute NaOH extraction widened the pores of the wall substantially and permitted observation by scanning electron microscopy of up to six distinct microfibrillar lamellae. Sequential chemical extraction of specific polysaccharides together with enzymic digestion of β-glucans allowed us to distinguish two distinct domains in the grass primary wall. First, a β-glucan-enriched domain, coextensive with GAXs of low degrees of arabinosyl substitution and glucomannans, is tightly associated around microfibrils. Second, a GAX that is more highly substituted with arabinosyl residues and additional glucomannan provides an interstitial domain that interconnects the β-glucan-coated microfibrils. Implications for current models that attempt to explain the biochemical and biophysical mechanism of wall loosening during cell growth are discussed. PMID:11598229

Environmental Impacts Of Zirab Coal Washing Plant, Mazandaran, Iran

NASA Astrophysics Data System (ADS)

Moore, F.; Esmaeili, A.

2009-04-01

Extraction and beneficiation operations associated with coal mining increase the rate of chemical reaction of waste material to air and water media. Zirab coal washing plant is located on the bank of the Cherat stream in Mazandaran province, Iran. coal Mined from central Alborz coalfield mines is not suitable for use in Iranian Steel Corporation. Hence, coal ash content is reduced by physical and chemical processes in this plant. These processes leave a large quantity of liquid and solid wastes that accumulate in waste dump and tailing dam. sediment and water samples taken from Sheshrudbar and Cherat streams and also from Talar river show high concentration of Cd, Mo and As in water samples of coal washing plant and the associated drainage. Eh-pH diagrams revealed the chemical species of elements in water. The enrichment factor and geoaccumulation index show that Cd, Hg, Mo and V are enriched in bottom sediments of the coal washing plant and decrease with increasing distance from the plant. Sequential extraction analysis Results of three sediment samples of Cherat stream show that silicate bound is the major phase in samples taken before and after the plant, but adjacent to the plant, organic bound is dominant. The high concentration of Cd and Mo in the water soluble phase, is noticeable and may result in high mobility and bioavailability of these elements. Mann-Whitney and Wilcoxon tests on six samples, before and after the coal washing plant support the obtained results. Keywords: Zirab; coal washing plant; Sequential extraction analysis; Mann-whitney; Wilcoxon; Enrichment factor; Geoaccumulation index.

Determination of isoxaflutole (balance) and its metabolites in water using solid phase extraction followed by high-performance liquid chromatography with ultraviolet or mass spectrometry.

PubMed

Lin, Chung-Ho; Lerch, Robert N; Thurman, E Michael; Garrett, Harold E; George, Milon F

2002-10-09

Balance (isoxaflutole, IXF) belongs to a new family of herbicides referred to as isoxazoles. IXF has a very short soil half-life (<24 h), degrading to a biologically active diketonitrile (DKN) metabolite that is more polar and considerably more stable. Further degradation of the DKN metabolite produces a nonbiologically active benzoic acid (BA) metabolite. Analytical methods using solid phase extraction followed by high-performance liquid chromatography-UV (HPLC-UV) or high-performance liquid chromatography-mass spectrometry (HPLC-MS) were developed for the analysis of IXF and its metabolites in distilled deionized water and ground water samples. To successfully detect and quantify the BA metabolite by HPLC-UV from ground water samples, a sequential elution scheme was necessary. Using HPLC-UV, the mean recoveries from sequential elution of the parent and its two metabolites from fortified ground water samples ranged from 68.6 to 101.4%. For HPLC-MS, solid phase extraction of ground water samples was performed using a polystyrene divinylbenzene polymer resin. The mean HPLC-MS recoveries of the three compounds from ground water samples spiked at 0.05-2 microg/L ranged from 100.9 to 110.3%. The limits of quantitation for HPLC-UV are approximately 150 ng/L for IXF, 100 ng/L for DKN, and 250 ng/L for BA. The limit of quantitation by HPLC-MS is 50 ng/L for each compound. The methods developed in this work can be applied to determine the transport and fate of Balance in the environment.

Characterization of As-polluted soils by laboratory X-ray-based techniques coupled with sequential extractions and electron microscopy: the case of Crocette gold mine in the Monte Rosa mining district (Italy).

PubMed

Allegretta, Ignazio; Porfido, Carlo; Martin, Maria; Barberis, Elisabetta; Terzano, Roberto; Spagnuolo, Matteo

2018-06-24

Arsenic concentration and distribution were studied by combining laboratory X-ray-based techniques (wavelength dispersive X-ray fluorescence (WDXRF), micro X-ray fluorescence (μXRF), and X-ray powder diffraction (XRPD)), field emission scanning electron microscopy equipped with microanalysis (FE-SEM-EDX), and sequential extraction procedure (SEP) coupled to total reflection X-ray fluorescence (TXRF) analysis. This approach was applied to three contaminated soils and one mine tailing collected near the gold extraction plant at the Crocette gold mine (Macugnaga, VB) in the Monte Rosa mining district (Piedmont, Italy). Arsenic (As) concentration, measured with WDXRF, ranged from 145 to 40,200 mg/kg. XRPD analysis evidenced the presence of jarosite and the absence of any As-bearing mineral, suggesting a high weathering grade and strong oxidative conditions. However, small domains of Fe arsenate were identified by combining μXRF with FE-SEM-EDX. SEP results revealed that As was mainly associated to amorphous Fe oxides/hydroxides or hydroxysulfates (50-80%) and the combination of XRPD and FE-SEM-EDX suggested that this phase could be attributed to schwertmannite. On the basis of the reported results, As is scarcely mobile, even if a consistent As fraction (1-3 g As/kg of soil) is still potentially mobilizable. In general, the proposed combination of laboratory X-ray techniques could be successfully employed to unravel environmental issues related to metal(loid) pollution in soil and sediments.

Flow injection spectrophotometric determination of V(V) involving on-line separation using a poly(vinylidene fluoride-co-hexafluoropropylene)-based polymer inclusion membrane.

PubMed

Yaftian, Mohammad Reza; Almeida, M Inês G S; Cattrall, Robert W; Kolev, Spas D

2018-05-01

A poly(vinylidene fluoride-co-hexafluoropropylene)-based polymer inclusion membrane (PIM) using Cyphos® IL 101 (i.e. trihexyl(tetradecyl)phosphonium chloride) as the carrier and 2-nitrophenyl octyl ether as a plasticizer in a mass ratio of 55/35/10 was employed for the on-line extractive separation of V(V) prior to its spectrophotometric determination in a flow injection analysis (FIA) system using xylenol orange as the colorimetric reagent. The selectivity of the membrane allowed the determination of V(V) in sulfate solutions in the presence of a variety of cations and anions. The interference of molybdenum(VI) was eliminated by off-line extraction using the same PIM. A univariate sequential optimization of the newly developed FIA system was conducted and under optimal conditions the system is characterized by a linear concentration range of 0.5-8.0mgL -1 , detection limit of 0.08mgL -1 and sample throughput of 4h -1 . The relative standard deviation at the 3mgL -1 level of V(V) was 2.9% based on 8 replicate determinations. The membrane was stable, which was reflected by the standard deviation value for determinations over three consecutive days (24 determinations of 3mgL -1 V(V)) of 3.6%. The newly developed FIA system was applied to the determination of V(V) in water and dietary supplements samples and a good agreement with inductively coupled plasma optical emission spectrometry was observed. Copyright © 2018 Elsevier B.V. All rights reserved.

Parallel Computations in Insect and Mammalian Visual Motion Processing

PubMed Central

Clark, Damon A.; Demb, Jonathan B.

2016-01-01

Sensory systems use receptors to extract information from the environment and neural circuits to perform subsequent computations. These computations may be described as algorithms composed of sequential mathematical operations. Comparing these operations across taxa reveals how different neural circuits have evolved to solve the same problem, even when using different mechanisms to implement the underlying math. In this review, we compare how insect and mammalian neural circuits have solved the problem of motion estimation, focusing on the fruit fly Drosophila and the mouse retina. Although the two systems implement computations with grossly different anatomy and molecular mechanisms, the underlying circuits transform light into motion signals with strikingly similar processing steps. These similarities run from photoreceptor gain control and spatiotemporal tuning to ON and OFF pathway structures, motion detection, and computed motion signals. The parallels between the two systems suggest that a limited set of algorithms for estimating motion satisfies both the needs of sighted creatures and the constraints imposed on them by metabolism, anatomy, and the structure and regularities of the visual world. PMID:27780048

Parallel Computations in Insect and Mammalian Visual Motion Processing.

PubMed

Clark, Damon A; Demb, Jonathan B

2016-10-24

Sensory systems use receptors to extract information from the environment and neural circuits to perform subsequent computations. These computations may be described as algorithms composed of sequential mathematical operations. Comparing these operations across taxa reveals how different neural circuits have evolved to solve the same problem, even when using different mechanisms to implement the underlying math. In this review, we compare how insect and mammalian neural circuits have solved the problem of motion estimation, focusing on the fruit fly Drosophila and the mouse retina. Although the two systems implement computations with grossly different anatomy and molecular mechanisms, the underlying circuits transform light into motion signals with strikingly similar processing steps. These similarities run from photoreceptor gain control and spatiotemporal tuning to ON and OFF pathway structures, motion detection, and computed motion signals. The parallels between the two systems suggest that a limited set of algorithms for estimating motion satisfies both the needs of sighted creatures and the constraints imposed on them by metabolism, anatomy, and the structure and regularities of the visual world. Copyright © 2016 Elsevier Ltd. All rights reserved.

Information Retrieval: A Sequential Learning Process.

ERIC Educational Resources Information Center

Bookstein, Abraham

1983-01-01

Presents decision-theoretic models which intrinsically include retrieval of multiple documents whereby system responds to request by presenting documents to patron in sequence, gathering feedback, and using information to modify future retrievals. Document independence model, set retrieval model, sequential retrieval model, learning model,…

Evaluation of Landsat-4 orbit determination accuracy using batch least-squares and sequential methods

NASA Astrophysics Data System (ADS)

Oza, D. H.; Jones, T. L.; Feiertag, R.; Samii, M. V.; Doll, C. E.; Mistretta, G. D.; Hart, R. C.

The Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) commissioned Applied Technology Associates, Incorporated, to develop the Real-Time Orbit Determination/Enhanced (RTOD/E) system on a Disk Operating System (DOS)-based personal computer (PC) as a prototype system for sequential orbit determination of spacecraft. This paper presents the results of a study to compare the orbit determination accuracy for a Tracking and Data Relay Satellite (TDRS) System (TDRSS) user spacecraft, Landsat-4, obtained using RTOD/E, operating on a PC, with the accuracy of an established batch least-squares system, the Goddard Trajectory Determination System (GTDS), operating on a mainframe computer. The results of Landsat-4 orbit determination will provide useful experience for the Earth Observing System (EOS) series of satellites. The Landsat-4 ephemerides were estimated for the May 18-24, 1992, timeframe, during which intensive TDRSS tracking data for Landsat-4 were available. During this period, there were two separate orbit-adjust maneuvers on one of the TDRSS spacecraft (TDRS-East) and one small orbit-adjust maneuver for Landsat-4. Independent assessments were made of the consistencies (overlap comparisons for the batch case and covariances and the first measurement residuals for the sequential case) of solutions produced by the batch and sequential methods. The forward-filtered RTOD/E orbit solutions were compared with the definitive GTDS orbit solutions for Landsat-4; the solution differences were generally less than 30 meters after the filter had reached steady state.

Evaluation of Landsat-4 orbit determination accuracy using batch least-squares and sequential methods

NASA Technical Reports Server (NTRS)

Oza, D. H.; Jones, T. L.; Feiertag, R.; Samii, M. V.; Doll, C. E.; Mistretta, G. D.; Hart, R. C.

1993-01-01

The Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) commissioned Applied Technology Associates, Incorporated, to develop the Real-Time Orbit Determination/Enhanced (RTOD/E) system on a Disk Operating System (DOS)-based personal computer (PC) as a prototype system for sequential orbit determination of spacecraft. This paper presents the results of a study to compare the orbit determination accuracy for a Tracking and Data Relay Satellite (TDRS) System (TDRSS) user spacecraft, Landsat-4, obtained using RTOD/E, operating on a PC, with the accuracy of an established batch least-squares system, the Goddard Trajectory Determination System (GTDS), operating on a mainframe computer. The results of Landsat-4 orbit determination will provide useful experience for the Earth Observing System (EOS) series of satellites. The Landsat-4 ephemerides were estimated for the May 18-24, 1992, timeframe, during which intensive TDRSS tracking data for Landsat-4 were available. During this period, there were two separate orbit-adjust maneuvers on one of the TDRSS spacecraft (TDRS-East) and one small orbit-adjust maneuver for Landsat-4. Independent assessments were made of the consistencies (overlap comparisons for the batch case and covariances and the first measurement residuals for the sequential case) of solutions produced by the batch and sequential methods. The forward-filtered RTOD/E orbit solutions were compared with the definitive GTDS orbit solutions for Landsat-4; the solution differences were generally less than 30 meters after the filter had reached steady state.

ProperCAD: A portable object-oriented parallel environment for VLSI CAD

NASA Technical Reports Server (NTRS)

Ramkumar, Balkrishna; Banerjee, Prithviraj

1993-01-01

Most parallel algorithms for VLSI CAD proposed to date have one important drawback: they work efficiently only on machines that they were designed for. As a result, algorithms designed to date are dependent on the architecture for which they are developed and do not port easily to other parallel architectures. A new project under way to address this problem is described. A Portable object-oriented parallel environment for CAD algorithms (ProperCAD) is being developed. The objectives of this research are (1) to develop new parallel algorithms that run in a portable object-oriented environment (CAD algorithms using a general purpose platform for portable parallel programming called CARM is being developed and a C++ environment that is truly object-oriented and specialized for CAD applications is also being developed); and (2) to design the parallel algorithms around a good sequential algorithm with a well-defined parallel-sequential interface (permitting the parallel algorithm to benefit from future developments in sequential algorithms). One CAD application that has been implemented as part of the ProperCAD project, flat VLSI circuit extraction, is described. The algorithm, its implementation, and its performance on a range of parallel machines are discussed in detail. It currently runs on an Encore Multimax, a Sequent Symmetry, Intel iPSC/2 and i860 hypercubes, a NCUBE 2 hypercube, and a network of Sun Sparc workstations. Performance data for other applications that were developed are provided: namely test pattern generation for sequential circuits, parallel logic synthesis, and standard cell placement.

Sequential Testing of Hypotheses Concerning the Reliability of a System Modeled by a Two-Parameter Weibull Distribution.

DTIC Science & Technology

1981-12-01

CONCERNING THE RELIABILITY OF A SYSTEM MODELED BY A TWO-PARAMETER WEIBULL DISTRIBUTION THESIS AFIT/GOR/MA/81D-8 Philippe A. Lussier 2nd Lt USAF... MODELED BY A TWO-PARAMETER WEIBULL DISTRIBUTION THESIS Presented to the Faculty of the School of Engineering of the Air Force Institute of Technology...repetitions are used for these test procedures. vi Sequential Testing of Hypotheses Concerning the Reliability of a System Modeled by a Two-Parameter

A cost and policy analysis comparing immediate sequential cataract surgery and delayed sequential cataract surgery from the physician perspective in the United States.

PubMed

Neel, Sean T

2014-11-01

A cost analysis was performed to evaluate the effect on physicians in the United States of a transition from delayed sequential cataract surgery to immediate sequential cataract surgery. Financial and efficiency impacts of this change were evaluated to determine whether efficiency gains could offset potential reduced revenue. A cost analysis using Medicare cataract surgery volume estimates, Medicare 2012 physician cataract surgery reimbursement schedules, and estimates of potential additional office visit revenue comparing immediate sequential cataract surgery with delayed sequential cataract surgery for a single specialty ophthalmology practice in West Tennessee. This model should give an indication of the effect on physicians on a national basis. A single specialty ophthalmology practice in West Tennessee was found to have a cataract surgery revenue loss of $126,000, increased revenue from office visits of $34,449 to $106,271 (minimum and maximum offset methods), and a net loss of $19,900 to $91,700 (base case) with the conversion to immediate sequential cataract surgery. Physicians likely stand to lose financially, and this loss cannot be offset by increased patient visits under the current reimbursement system. This may result in physician resistance to converting to immediate sequential cataract surgery, gaming, and supplier-induced demand.

Real-Time Detection and Tracking of Multiple People in Laser Scan Frames

NASA Astrophysics Data System (ADS)

Cui, J.; Song, X.; Zhao, H.; Zha, H.; Shibasaki, R.

This chapter presents an approach to detect and track multiple people ro bustly in real time using laser scan frames. The detection and tracking of people in real time is a problem that arises in a variety of different contexts. Examples in clude intelligent surveillance for security purposes, scene analysis for service robot, and crowd behavior analysis for human behavior study. Over the last several years, an increasing number of laser-based people-tracking systems have been developed in both mobile robotics platforms and fixed platforms using one or multiple laser scanners. It has been proved that processing on laser scanner data makes the tracker much faster and more robust than a vision-only based one in complex situations. In this chapter, we present a novel robust tracker to detect and track multiple people in a crowded and open area in real time. First, raw data are obtained that measures two legs for each people at a height of 16 cm from horizontal ground with multiple registered laser scanners. A stable feature is extracted using accumulated distribu tion of successive laser frames. In this way, the noise that generates split and merged measurements is smoothed well, and the pattern of rhythmic swinging legs is uti lized to extract each leg. Second, a probabilistic tracking model is presented, and then a sequential inference process using a Bayesian rule is described. A sequential inference process is difficult to compute analytically, so two strategies are presented to simplify the computation. In the case of independent tracking, the Kalman fil ter is used with a more efficient measurement likelihood model based on a region coherency property. Finally, to deal with trajectory fragments we present a concise approach to fuse just a little visual information from synchronized video camera to laser data. Evaluation with real data shows that the proposed method is robust and effective. It achieves a significant improvement compared with existing laser-based trackers.

Unraveling the Fate and Transport of SrEDTA-2 and Sr+2 in Hanford Sediments

NASA Astrophysics Data System (ADS)

Pace, M. N.; Mayes, M. A.; Jardine, P. M.; Mehlhorn, T. L.; Liu, Q. G.; Yin, X. L.

2004-12-01

Accelerated migration of strontium-90 has been observed in the vadose zone beneath the Hanford tank farm. The goal of this paper is to provide an improved understanding of the hydrogeochemical processes that contribute to strontium transport in the far-field Hanford vadose zone. Laboratory scale batch, saturated packed column experiments, and an unsaturated transport experiment in an undisturbed core were conducted to quantify geochemical and hydrological processes controlling Sr+2 and SrEDTA-2 sorption to Hanford flood deposits. After experimentation, the undisturbed core was disassembled and samples were collected from different bedding units as a function of depth. Sequential extractions were then performed on the samples. It has been suggested that organic chelates such as EDTA may be responsible for the accelerated transport of strontium due to the formation of stable anionic complexes. Duplicate batch and column experiments performed with Sr+2 and SrEDTA-2 suggested that the SrEDTA-2 complex was not stable in the presence of soil and rapid dissociation allowed strontium to be transported as a divalent cation. Batch experiments indicated a decrease in sorption with increasing rock:water ratios, whereas saturated packed column experiments indicated equal retardation in columns of different lengths. This difference between the batch and column experiments is primarily due to the difference between equilibrium conditions where dissolution of cations may compete for sorption sites versus flowing conditions where any dissolved cations are flushed through the system minimizing competition for sorption sites. Unsaturated transport in the undisturbed core resulted in significant Sr+2 retardation despite the presence of physical nonequilibrium. Core disassembly and sequential extractions revealed the mass wetness distribution and reactive mineral phases associated with strontium in the core. Overall, results indicated that strontium will most likely be transported through the Hanford far-field vadose zone as a divalent cation.

Semi-automated 96-well solid-phase extraction and gas chromatography-negative chemical ionization tandem mass spectrometry for the trace analysis of fluprostenol in rat plasma.

PubMed

Gauw, R D; Stoffolano, P J; Kuhlenbeck, D L; Patel, V S; Garver, S M; Baker, T R; Wehmeyer, K R

2000-07-21

Semi-automated 96-well plate solid-phase extraction (SPE) was used for sample preparation of fluprostenol, a prostaglandin analog, in rat plasma prior to detection by gas chromatography-negative chemical ionization tandem mass spectrometry (GC-NCI-MS-MS). A liquid handling system was utilized for all aspects of sample handling prior to SPE including transferring of samples into a 96-well format, preparation of standards as well as addition of internal standard to standards, quality control samples and study samples. SPE was performed in a 96-well plate format using octadecylsilane packing and the effluent from the SPE was dried in a custom-made 96-well apparatus. The sample residue was derivatized sequentially with pentafluorobenzylbromide followed by N-methyl-N-trimethylsilyltrifluoroacetamide. The derivatized sample was then analyzed using GC-NCI-MS-MS. The dynamic range for the method was from 7 to 5800 pg/ml with a 0.1-ml plasma sample. The methodology was evaluated over a 4-day period and demonstrated an accuracy of 90-106% with a precision of 2.4-12.9%.

Extraction of mercury from groundwater using immobilized algae.

PubMed

Barkley, N P

1991-10-01

Bio-Recovery Systems, Inc. conducted a project under the Emerging Technology portion of the United States Environmental Protection Agency's (EPAs) Superfund Innovative Technology Evaluation (SITE) Program to evaluate the ability of immobilized algae to adsorb mercury from contaminated groundwater in laboratory studies and pilot-scale field tests. Algal biomass was incorporated in a permeable polymeric matrix. The product, AlgaSORB, packed into adsorption columns, exhibited excellent flow characteristics, and functioned as a "biological" ion exchange resin. A sequence of eleven laboratory tests demonstrated the ability of this product to adsorb mercury from groundwater that contained high levels of total dissolved solids and hard water components. However, use of a single AlgaSORB preparation yielded nonrepeatable results with samples collected at different times of the year. The strategy of sequentially extracting the groundwater through two columns containing different preparations of AlgaSORB was developed and proved successful in laboratory and pilot-scale field tests. Field test results indicate that AlgaSORB could be economically competitive with ion exchange resins for removal of mercury, with the advantage that hardness and other dissolved solids do not appear to compete with heavy metals for binding capacity.

Mitochondrial rhodanese: membrane-bound and complexed activity.

PubMed

Ogata, K; Volini, M

1990-05-15

We have proposed that phosphorylated and dephosphorylated forms of the mitochondrial sulfurtransferase, rhodanese, function as converter enzymes that interact with membrane-bound iron-sulfur centers of the electron transport chain to modulate the rate of mitochondrial respiration (Ogata, K., Dai, X., and Volini, M. (1989) J. Biol. Chem. 204, 2718-2725). In the present studies, we have explored some structural aspects of the mitochondrial rhodanese system. By sequential extraction of lysed mitochondria with phosphate buffer and phosphate buffer containing 20 mM cholate, we have shown that 30% of the rhodanese activity of bovine liver is membrane-bound. Resolution of cholate extracts on Sephadex G-100 indicates that part of the bound rhodanese is complexed with other mitochondrial proteins. Tests with the complex show that it forms iron-sulfur centers when incubated with the rhodanese sulfur-donor substrate thiosulfate, iron ions, and a reducing agent. Experiments on the rhodanese activity of rat liver mitochondria give similar results. Taken together, the findings indicate that liver rhodanese is in part bound to the mitochondrial membrane as a component of a multiprotein complex that forms iron-sulfur centers. The findings are consistent with the role we propose for rhodanese in the modulation of mitochondrial respiratory activity.

Antimicrobial potential of Australian macrofungi extracts against foodborne and other pathogens.

PubMed

Bala, Neeraj; Aitken, Elizabeth A B; Cusack, Andrew; Steadman, Kathryn J

2012-03-01

Basidiomycetous macrofungi have therapeutic potential due to antimicrobial activity but little information is available for Australian macrofungi. Therefore, the present study investigated 12 Australian basidiomycetous macrofungi, previously shown to have promising activity against Staphylococcus aureus and Escherichia coli, for their antimicrobial potential against a range of other clinically relevant micro-organisms. Fruiting bodies were collected from across Queensland, Australia, freeze-dried and sequentially extracted with water and ethanol. The crude extracts were tested at 10 mg/mL and 1 mg/mL against six pathogens including two Gram-positive and two Gram-negative bacteria along with two fungi using a high throughput 96-well microplate bioassay. A degree of specificity in activity was exhibited by the water extract of Ramaria sp. (Gomphaceae) and the ethanol extracts of Psathyrella sp. (Psathyrellaceae) and Hohenbuehelia sp., which inhibited the growth of the two fungal pathogens used in the assay. Similarly, the ethanol extract of Fomitopsis lilacinogilva (Fomitopsidaceae) was active against the Gram-positive bacteria B. cereus only. Activity against a wider range of the microorganisms used in the assay was exhibited by the ethanol extract of Ramaria sp. and the water extract of Hohenbuehelia sp. (Pleurotaceae). These macrofungi can serve as new sources for the discovery and development of much needed new antimicrobials. Copyright © 2011 John Wiley & Sons, Ltd.

Antiparkinsonian effects of aqueous methanolic extract of Hyoscyamus niger seeds result from its monoamine oxidase inhibitory and hydroxyl radical scavenging potency.

PubMed

Sengupta, T; Vinayagam, J; Nagashayana, N; Gowda, B; Jaisankar, P; Mohanakumar, K P

2011-01-01

Hyoscyamus species is one of the four plants used in Ayurveda for the treatment of Parkinson's disease (PD). Since Hyoscyamus niger was found to contain negligible levels of L-DOPA, we evaluated neuroprotective potential, if any, of characterized petroleum ether and aqueous methanol extracts of its seeds in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD in mice. Air dried authenticated H. niger seeds were sequentially extracted using petroleum ether and aqueous methanol and were characterized employing HPLC-electrochemistry and LCMS. Parkinsonian mice were treated daily twice with the extracts (125-500 mg/kg, p.o.) for two days and motor functions and striatal dopamine levels were assayed. Administration of the aqueous methanol extract (containing 0.03% w/w of L-DOPA), but not petroleum ether extract, significantly attenuated motor disabilities (akinesia, catalepsy and reduced swim score) and striatal dopamine loss in MPTP treated mice. Since the extract caused significant inhibition of monoamine oxidase activity and attenuated 1-methyl-4-phenyl pyridinium (MPP+)-induced hydroxyl radical (·OH) generation in isolated mitochondria, it is possible that the methanolic extract of Hyoscyamus niger seeds protects against parkinsonism in mice by means of its ability to inhibit increased ·OH generated in the mitochondria.

Tribulus terrestris (Linn.) Attenuates Cellular Alterations Induced by Ischemia in H9c2 Cells Via Antioxidant Potential.

PubMed

Reshma, P L; Lekshmi, V S; Sankar, Vandana; Raghu, K G

2015-06-01

Tribulus terrestris L. was evaluated for its cardioprotective property against myocardial ischemia in a cell line model. Initially, methanolic extract was prepared and subjected to sequential extraction with various solvents. The extract with high phenolic content (T. terrestris L. ethyl acetate extract-TTME) was further characterized for its chemical constituents and taken forward for evaluation against cardiac ischemia. HPLC analysis revealed the presence of phenolic compounds like caffeic acid (12.41 ± 0.22 mg g(-1)), chlorogenic acid (0.52 ± 0.06 mg g(-1)) and 4-hydroxybenzoic acid (0.60 ± 0.08 mg g(-1)). H9c2 cells were pretreated with TTME (10, 25, 50 and 100 µg/ml) for 24 h before the induction of ischemia. Then ischemia was induced by exposing cells to ischemia buffer, in a hypoxic chamber, maintained at 0.1% O2, 95% N2 and 5% CO2, for 1 h. A significant (p ≤ 0.05) increase in reactive oxygen species generation (56%), superoxide production (18%), loss of plasma membrane integrity, dissipation of transmembrane potential, permeability transition pore opening and apoptosis had been observed during ischemia. However, pretreatment with TTME was found to significantly (p ≤ 0.05) attenuate the alterations caused by ischemia. The overall results of this study partially reveal the scientific basis of the use of T. terrestris L. in the traditional system of medicine for heart diseases. Copyright © 2015 John Wiley & Sons, Ltd.

Fractionation and characterization of semi polar and polar compounds from leaf extract Nicotiana tabaccum L. reflux ethanol extraction results

NASA Astrophysics Data System (ADS)

Rahardjo, Andhika Priotomo; Fauzantoro, Ahmad; Gozan, Misri

2018-02-01

The decline in cigarette production as the solution of health problems can interfere with the welfare of tobacco farmers in Indonesia. So, it is required to utilize the alternative uses of tobacco with chemical compounds inside it as the raw material for producing alternative products. One of the methods that is efficient in separating chemical compounds from plant extracts is fractionation and characterization method. This method has never been used for Nicotiana tabaccum L. extract using semi polar and polar solvents. This study begins with preparing Nicotiana tabaccum L. extract ingredients obtained through reflux ethanol extraction process. Extracts are analyzed by HPLC which serves to determine the chemical compounds in tobacco extract qualitatively. Extract that has been analyzed, is then fractionated using column chromatography with semi polar (ethyl acetate) and polar (ethane) solvents sequentially. Chemical compounds from tobacco extracts will be dissolved in accordance with the polarity of each solvents. The chemical compound is then characterized using HPLC quantitatively and qualitatively. Then, the data that has been obtained is used to find the partition coefficient of the main components in Nicotiana tabaccum L., which is Nicotine (kN) in Virginia 1 (Ethyl Acetate) fraction at 0.075; Virginia 2 (Ethyl Acetate) fraction at 0.037; And Virginia 3 (Ethyl Acetate) fraction at 0.043.

Flourensia cernua: Hexane Extracts a Very Active Mycobactericidal Fraction from an Inactive Leaf Decoction against Pansensitive and Panresistant Mycobacterium tuberculosis

PubMed Central

Molina-Salinas, Gloria María; Peña-Rodríguez, Luis Manuel; Mata-Cárdenas, Benito David; Escalante-Erosa, Fabiola; González-Hernández, Silvia; Torres de la Cruz, Víctor Manuel; Martínez-Rodríguez, Herminia Guadalupe; Said-Fernández, Salvador

2011-01-01

The efficacy of decoction in extracting mycobactericidal compounds from Flourensia cernua (Hojasé) leaves and fractionation with solvents having ascending polarity was compared with that of (i) ethanol extraction by still maceration, extraction with a Soxhlet device, shake-assisted maceration, or ultrasound-assisted maceration, followed by fractionation with n-hexane, ethyl acetate, and n-butanol; (ii) sequential extraction with n-hexane, ethyl acetate, and n-butanol, by still maceration, using a Soxhlet device, shake-assisted maceration, or ultrasound-assisted maceration. The in vitro mycobactericidal activity of each preparation was measured against drug-sensitive (SMtb) and drug-resistant (RMtb) Mycobacterium tuberculosis strains. The results of which were expressed as absolute mycobactericidal activity (AMA). These data were normalized to the ΣAMA of the decoction fraction set. Although decoction was inactive, the anti-RMtb normalized ΣAMA (NAMA) of its fractions was comparable with the anti-RMtb NAMA of the still maceration extracts and significantly higher than the anti-SMtb and anti-RMtb NAMAs of every other ethanol extract and serial extract and fraction. Hexane extracted, from decoction, material having 55.17% and 92.62% of antituberculosis activity against SMtb and RMtb, respectively. Although the mycobactericidal activity of decoction is undetectable; its efficacy in extracting F. cernua active metabolites against M. tuberculosis is substantially greater than almost all pharmacognostic methods. PMID:21584254

Sequential chemical extraction for a phosphogypsum environmental impact evaluation

NASA Astrophysics Data System (ADS)

Gennari, R. F.; Garcia, I.; Medina, N. H.; Silveira, M. A. G.

2013-05-01

Phosphogypsum (PG) is gypsum generated during phosphoric acid production. PG is stocked in large stacks or accumulated in lakes; it contains heavy metals and naturally occurring radioactive elements. The metal contamination may affect the functionality, sustainability and biodiversity of ecosystems. In this work, PG samples were analyzed by Plasma Spectrometry. Total metal content and in the extractable fraction of chemical elements were determined. For K, Ni, Zn, Cr, Cd, Ba, Pb and U, the results obtained are lower than those obtained in a Idaho plant are including and also lower than those found in the soil, indicating this PG sample analyzed probably will not cause any additional metal neither natural radiation contamination.

Remediation of cadmium- and lead-contaminated agricultural soil by composite washing with chlorides and citric acid.

PubMed

Li, Yu-jiao; Hu, Peng-jie; Zhao, Jie; Dong, Chang-xun

2015-04-01

Composite washing of cadmium (Cd)- and lead (Pb)-contaminated agricultural soil from Hunan province in China using mixtures of chlorides (FeCl3, CaCl2) and citric acid (CA) was investigated. The concentrations of composite washing agents for metal removal were optimized. Sequential extraction was conducted to study the changes in metal fractions after soil washing. The removal of two metals at optimum concentration was reached. Using FeCl3 mixed with CA, 44% of Cd and 23% of Pb were removed, and 49 and 32% by CaCl2 mixed with CA, respectively. The mechanism of composite washing was postulated. A mixture of chlorides and CA enhanced metal extraction from soil through the formation of metal-chloride and metal-citrate complexes. CA in extract solutions promoted the formation of metal-chloride complexes and reduced the solution pH. Composite washing reduced Cd and Pb in Fe-Mn oxide forms significantly. Chlorides and CA exerted a synergistic effect on metal extraction during composite washing.

Protective effects of different marigold (Calendula officinalis L.) and rosemary cream preparations against sodium-lauryl-sulfate-induced irritant contact dermatitis.

PubMed

Fuchs, S M; Schliemann-Willers, S; Fischer, T W; Elsner, P

2005-01-01

In the present study, we evaluated the protective action of cream preparations containing seven different types of marigold and rosemary extracts in vivo in healthy volunteers with experimentally induced irritant contact dermatitis (ICD). Marigold and rosemary extracts in base cream DAC (Deutscher Arzneimittel-Codex = German Pharmaceutical Codex) were tested in a 4-day repetitive irritation test using sodium lauryl sulfate. The effect was evaluated visually and quantified by noninvasive bioengineering methods, namely chromametry and tewametry. When the test products were applied parallel to the induction period of ICD, a statistically significant protective effect of all cream preparations was observed by all methods. This effect, although not statistically significant, was superior to control by undyed marigold und faradiol ester-enriched extracts in chromametry and by dyed and undyed rosemary extracts in tewametry. The sequential treatment (postirritation) once a day for 5 days was without any effect. Thus, a protective effect of some marigold and rosemary extracts against ICD could be shown in the elicitation phase. Copyright (c) 2005 S. Karger AG, Basel.

In vitro glucose uptake activity of Aegles marmelos and Syzygium cumini by activation of Glut-4, PI3 kinase and PPARgamma in L6 myotubes.

PubMed

Anandharajan, R; Jaiganesh, S; Shankernarayanan, N P; Viswakarma, R A; Balakrishnan, A

2006-06-01

The purpose of the present study is to investigate the effect of methanolic extracts of Aegles marmelos and Syzygium cumini on a battery of targets glucose transporter (Glut-4), peroxisome proliferator activator receptor gamma (PPARgamma) and phosphatidylinositol 3' kinase (PI3 kinase) involved in glucose transport. A. marmelos and S. cumini are anti-diabetic medicinal plants being used in Indian traditional medicine. Different solvent extracts extracted sequentially were analysed for glucose uptake activity at each step and methanol extracts were found to be significantly active at 100ng/ml dose comparable with insulin and rosiglitazone. Elevation of Glut-4, PPARgamma and PI3 kinase by A. marmelos and S. cumini in association with glucose transport supported the up-regulation of glucose uptake. The inhibitory effect of cycloheximide on A. marmelos- and S. cumini-mediated glucose uptake suggested that new protein synthesis is required for the elevated glucose transport. Current observation concludes that methanolic extracts of A. marmelos and S. cumini activate glucose transport in a PI3 kinase-dependent fashion.

Sequential design of discrete linear quadratic regulators via optimal root-locus techniques

NASA Technical Reports Server (NTRS)

Shieh, Leang S.; Yates, Robert E.; Ganesan, Sekar

1989-01-01

A sequential method employing classical root-locus techniques has been developed in order to determine the quadratic weighting matrices and discrete linear quadratic regulators of multivariable control systems. At each recursive step, an intermediate unity rank state-weighting matrix that contains some invariant eigenvectors of that open-loop matrix is assigned, and an intermediate characteristic equation of the closed-loop system containing the invariant eigenvalues is created.

Sequential Feedback Scheme Outperforms the Parallel Scheme for Hamiltonian Parameter Estimation.

PubMed

Yuan, Haidong

2016-10-14

Measurement and estimation of parameters are essential for science and engineering, where the main quest is to find the highest achievable precision with the given resources and design schemes to attain it. Two schemes, the sequential feedback scheme and the parallel scheme, are usually studied in the quantum parameter estimation. While the sequential feedback scheme represents the most general scheme, it remains unknown whether it can outperform the parallel scheme for any quantum estimation tasks. In this Letter, we show that the sequential feedback scheme has a threefold improvement over the parallel scheme for Hamiltonian parameter estimations on two-dimensional systems, and an order of O(d+1) improvement for Hamiltonian parameter estimation on d-dimensional systems. We also show that, contrary to the conventional belief, it is possible to simultaneously achieve the highest precision for estimating all three components of a magnetic field, which sets a benchmark on the local precision limit for the estimation of a magnetic field.

Sequential Combination of Electro-Fenton and Electrochemical Chlorination Processes for the Treatment of Anaerobically-Digested Food Wastewater.

PubMed

Shin, Yong-Uk; Yoo, Ha-Young; Kim, Seonghun; Chung, Kyung-Mi; Park, Yong-Gyun; Hwang, Kwang-Hyun; Hong, Seok Won; Park, Hyunwoong; Cho, Kangwoo; Lee, Jaesang

2017-09-19

A two-stage sequential electro-Fenton (E-Fenton) oxidation followed by electrochemical chlorination (EC) was demonstrated to concomitantly treat high concentrations of organic carbon and ammonium nitrogen (NH 4 + -N) in real anaerobically digested food wastewater (ADFW). The anodic Fenton process caused the rapid mineralization of phenol as a model substrate through the production of hydroxyl radical as the main oxidant. The electrochemical oxidation of NH 4 + by a dimensionally stable anode (DSA) resulted in temporal concentration profiles of combined and free chlorine species that were analogous to those during the conventional breakpoint chlorination of NH 4 + . Together with the minimal production of nitrate, this confirmed that the conversion of NH 4 + to nitrogen gas was electrochemically achievable. The monitoring of treatment performance with varying key parameters (e.g., current density, H 2 O 2 feeding rate, pH, NaCl loading, and DSA type) led to the optimization of two component systems. The comparative evaluation of two sequentially combined systems (i.e., the E-Fenton-EC system versus the EC-E-Fenton system) using the mixture of phenol and NH 4 + under the predetermined optimal conditions suggested the superiority of the E-Fenton-EC system in terms of treatment efficiency and energy consumption. Finally, the sequential E-Fenton-EC process effectively mineralized organic carbon and decomposed NH 4 + -N in the real ADFW without external supply of NaCl.

Comparative Study of Green Sub- and Supercritical Processes to Obtain Carnosic Acid and Carnosol-Enriched Rosemary Extracts with in Vitro Anti-Proliferative Activity on Colon Cancer Cells

PubMed Central

Sánchez-Camargo, Andrea del Pilar; García-Cañas, Virginia; Herrero, Miguel; Cifuentes, Alejandro; Ibáñez, Elena

2016-01-01

In the present work, four green processes have been compared to evaluate their potential to obtain rosemary extracts with in vitro anti-proliferative activity against two colon cancer cell lines (HT-29 and HCT116). The processes, carried out under optimal conditions, were: (1) pressurized liquid extraction (PLE, using an hydroalcoholic mixture as solvent) at lab-scale; (2) Single-step supercritical fluid extraction (SFE) at pilot scale; (3) Intensified two-step sequential SFE at pilot scale; (4) Integrated PLE plus supercritical antisolvent fractionation (SAF) at pilot scale. Although higher extraction yields were achieved by using PLE (38.46% dry weight), this extract provided the lowest anti-proliferative activity with no observed cytotoxic effects at the assayed concentrations. On the other hand, extracts obtained using the PLE + SAF process provided the most active rosemary extracts against both colon cancer cell lines, with LC50 ranging from 11.2 to 12.4 µg/mL and from 21.8 to 31.9 µg/mL for HCT116 and HT-29, respectively. In general, active rosemary extracts were characterized by containing carnosic acid (CA) and carnosol (CS) at concentrations above 263.7 and 33.9 mg/g extract, respectively. Some distinct compounds have been identified in the SAF extracts (rosmaridiphenol and safficinolide), suggesting their possible role as additional contributors to the observed strong anti-proliferative activity of CA and CS in SAF extracts. PMID:27941607

Comparative Study of Green Sub- and Supercritical Processes to Obtain Carnosic Acid and Carnosol-Enriched Rosemary Extracts with in Vitro Anti-Proliferative Activity on Colon Cancer Cells.

PubMed

Sánchez-Camargo, Andrea Del Pilar; García-Cañas, Virginia; Herrero, Miguel; Cifuentes, Alejandro; Ibáñez, Elena

2016-12-07

In the present work, four green processes have been compared to evaluate their potential to obtain rosemary extracts with in vitro anti-proliferative activity against two colon cancer cell lines (HT-29 and HCT116). The processes, carried out under optimal conditions, were: (1) pressurized liquid extraction (PLE, using an hydroalcoholic mixture as solvent) at lab-scale; (2) Single-step supercritical fluid extraction (SFE) at pilot scale; (3) Intensified two-step sequential SFE at pilot scale; (4) Integrated PLE plus supercritical antisolvent fractionation (SAF) at pilot scale. Although higher extraction yields were achieved by using PLE (38.46% dry weight), this extract provided the lowest anti-proliferative activity with no observed cytotoxic effects at the assayed concentrations. On the other hand, extracts obtained using the PLE + SAF process provided the most active rosemary extracts against both colon cancer cell lines, with LC 50 ranging from 11.2 to 12.4 µg/mL and from 21.8 to 31.9 µg/mL for HCT116 and HT-29, respectively. In general, active rosemary extracts were characterized by containing carnosic acid (CA) and carnosol (CS) at concentrations above 263.7 and 33.9 mg/g extract, respectively. Some distinct compounds have been identified in the SAF extracts (rosmaridiphenol and safficinolide), suggesting their possible role as additional contributors to the observed strong anti-proliferative activity of CA and CS in SAF extracts.

Assessment of a geochemical extraction procedure to determine the solid phase fractionation and bioaccessibility of potentially harmful elements in soils: a case study using the NIST 2710 reference soil.

PubMed

Wragg, Joanna; Cave, Mark

2012-04-13

Three mineral acid sequential extraction regimes (HNO(3) only, HNO(3) followed by HCl and aqua regia) were applied to the NIST 2710 contaminated reference soil. The major and trace element chemical analysis data from the extractions were subjected to a chemometric self-modelling mixture resolution procedure which identified that 12 distinct physico-chemical components were extracted. The fractionation of As, Cd, Ni and Pb between these components were determined. Tentative assignments of the mineralogical sources of the components were made. The human ingestion bioaccessible fraction of As, Cd and Pb were determined using the in vitro BARGE UBM bioaccessibility test and were found to be 51.6%, 68.0% and 68.4% respectively. The relationship between the lability of the physico-chemical components and the bioaccessible fraction of the soils was investigated and the bioaccessible fractions were assigned to specific components. The extraction scheme using aqua regia was found to be the most suitable as it was the only one which extracted the iron sulphide phase in the soil. Copyright © 2012 Elsevier B.V. All rights reserved.

Bioerodible System for Sequential Release of Multiple Drugs

PubMed Central

Sundararaj, Sharath C.; Thomas, Mark V.; Dziubla, Thomas D.; Puleo, David A.

2013-01-01

Because many complex physiological processes are controlled by multiple biomolecules, comprehensive treatment of certain disease conditions may be more effectively achieved by administration of more than one type of drug. Thus, the objective of the present research was to develop a multilayered, polymer-based system for sequential delivery of multiple drugs. The polymers used were cellulose acetate phthalate (CAP) complexed with Pluronic F-127 (P). After evaluating morphology of the resulting CAPP system, in vitro release of small molecule drugs and a model protein was studied from both single and multilayered devices. Drug release from single-layered CAPP films followed zero-order kinetics related to surface erosion of the association polymer. Release studies from multilayered CAPP devices showed the possibility of achieving intermittent release of one type of drug as well as sequential release of more than one type of drug. Mathematical modeling accurately predicted the release profiles for both single layer and multilayered devices. The present CAPP association polymer-based multilayer devices can be used for localized, sequential delivery of multiple drugs for the possible treatment of complex disease conditions, and perhaps for tissue engineering applications, that require delivery of more than one type of biomolecule. PMID:24096151

Automatic sequential fluid handling with multilayer microfluidic sample isolated pumping

PubMed Central

Liu, Jixiao; Fu, Hai; Yang, Tianhang; Li, Songjing

2015-01-01

To sequentially handle fluids is of great significance in quantitative biology, analytical chemistry, and bioassays. However, the technological options are limited when building such microfluidic sequential processing systems, and one of the encountered challenges is the need for reliable, efficient, and mass-production available microfluidic pumping methods. Herein, we present a bubble-free and pumping-control unified liquid handling method that is compatible with large-scale manufacture, termed multilayer microfluidic sample isolated pumping (mμSIP). The core part of the mμSIP is the selective permeable membrane that isolates the fluidic layer from the pneumatic layer. The air diffusion from the fluidic channel network into the degassing pneumatic channel network leads to fluidic channel pressure variation, which further results in consistent bubble-free liquid pumping into the channels and the dead-end chambers. We characterize the mμSIP by comparing the fluidic actuation processes with different parameters and a flow rate range of 0.013 μl/s to 0.097 μl/s is observed in the experiments. As the proof of concept, we demonstrate an automatic sequential fluid handling system aiming at digital assays and immunoassays, which further proves the unified pumping-control and suggests that the mμSIP is suitable for functional microfluidic assays with minimal operations. We believe that the mμSIP technology and demonstrated automatic sequential fluid handling system would enrich the microfluidic toolbox and benefit further inventions. PMID:26487904

Sequential visibility-graph motifs

NASA Astrophysics Data System (ADS)

Iacovacci, Jacopo; Lacasa, Lucas

2016-04-01

Visibility algorithms transform time series into graphs and encode dynamical information in their topology, paving the way for graph-theoretical time series analysis as well as building a bridge between nonlinear dynamics and network science. In this work we introduce and study the concept of sequential visibility-graph motifs, smaller substructures of n consecutive nodes that appear with characteristic frequencies. We develop a theory to compute in an exact way the motif profiles associated with general classes of deterministic and stochastic dynamics. We find that this simple property is indeed a highly informative and computationally efficient feature capable of distinguishing among different dynamics and robust against noise contamination. We finally confirm that it can be used in practice to perform unsupervised learning, by extracting motif profiles from experimental heart-rate series and being able, accordingly, to disentangle meditative from other relaxation states. Applications of this general theory include the automatic classification and description of physical, biological, and financial time series.

Characterization of pH-fractionated humic acids with respect to their dissociation behaviour.

PubMed

Klučáková, Martina

2016-04-01

Humic acids were divided into several fractions using buffer solutions as extraction agents with different pH values. Two methods of fractionation were used. The first one was subsequent dissolution of bulk humic acids in buffers adjusted to different pH. The second one was sequential dissolution in buffers with increasing pH values. Experimental data were compared with hypothesis of partial solubility of humic acids in aqueous solutions. Behaviour of humic fractions obtained by sequential dissolution, original bulk sample and residual fractions obtained by subsequent dissolution at pH 10 and 12 agrees with the hypothesis. Results demonstrated that regardless the common mechanism, solubility and dissociation degree of various humic fractions may be very different and can be estimated using parameters of the model based on the proposed mechanism. Presented results suggest that dissolving of solid humic acids in water environment is more complex than conventional solubility behaviour of sparingly soluble solids.

Radionuclide studies of chronic schistosomal uropathy. [/sup 99m/Tc-DTPA; /sup 131/I-hippuran

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

Lamki, L.M.; Lamki, N.

1981-08-01

Fifty patients with chronic urinary tract schistosomiasis were studied with /sup 99m/Tc-DTPA. All had a flow study, sequential analog imaging, and digital imaging for 25 to 35 min (20-sec frames). Time-activity curves (DTPA renograms) were extracted; 12 patients had /sup 131/I-Hippuran probe renograms as well. Renal changes included diminished perfusion and structural abnormalities ranging from minor calyceal dilatation to overt hydronephrosis. Ureteral changes included dilatation, tortuosity, and kinking. Marked distortion of the ureterovesical junction was seen in some patients due to periureteral and perivesicular fibrosis, which is a major factor in upper urinary tract damage. Renograms showed varying obstruction andmore » parenchymal damage. Nuclear medicine complements excretory urography and is sometimes preferable for visualization of the ureters. After the initial urogram, sequential DTPA scanning and renography are sufficient for follow-up.« less

An improved protocol for the preparation of total genomic DNA from isolates of yeast and mould using Whatman FTA filter papers.

PubMed

Borman, Andrew M; Fraser, Mark; Linton, Christopher J; Palmer, Michael D; Johnson, Elizabeth M

2010-06-01

Here, we present a significantly improved version of our previously published method for the extraction of fungal genomic DNA from pure cultures using Whatman FTA filter paper matrix technology. This modified protocol is extremely rapid, significantly more cost effective than our original method, and importantly, substantially reduces the problem of potential cross-contamination between sequential filters when employing FTA technology.

Some contributions to the application of LC-NMR, LC-MS, and LC-CD to the biosynthesis of isoquinoline alkaloids using callus cultures.

PubMed

Iwasa, K; Moriyasu, M; Wiegrebe, W

2012-07-01

Hyphenated spectroscopic techniques in combination with a special extraction and work-up of plant calli cultures of Berberidaceae, Fumariaceae, and Papaveraceae families, e.g., enabled us to get deeper insight into the sequential biochemical conversions of precursors into simple isoquinoline- and protoberberine-alkaloids and their follow-up-products with different skeletons. Some new alkaloids of these types have been found.