Benthic algae of benchmark streams in agricultural areas of eastern Wisconsin
Scudder, Barbara C.; Stewart, Jana S.
2001-01-01
Multivariate analyses indicated multiple scales of environmental factors affect algae. Although two-way indicator species analysis (TWINSPAN), detrended correspondence analysis (DCA), and canonical correspondence analysis (CCA) generally separated sites according to RHU, only DCA ordination indicated a separation of sites according to ecoregion. Environmental variables con-elated with DCA axes 1 and 2 and therefore indicated as important explanatory factors for algal distribution and abundance were factors related to stream size, basin land use/cover, geomorphology, hydrogeology, and riparian disturbance. CCA analyses with a more limited set of environmental variables indicated that pH, average width of natural riparian vegetation (segment scale), basin land use/cover and Q/Q2 were the most important variables affecting the distribution and relative abundance of benthic algae at the 20 benchmark streams,
NASA Astrophysics Data System (ADS)
Rahman, Inayat Ur; Khan, Nasrullah; Ali, Kishwar
2017-04-01
An understory vegetation survey of the Pinus wallichiana-dominated temperate forests of Swat District was carried out to inspect the structure, composition and ecological associations of the forest vegetation. A quadrat method of sampling was used to record the floristic and phytosociological data necessary for the analysis using 300 quadrats of 10 × 10 m each. Some vegetation parameters viz. frequency and density for trees (overstory vegetation) as well as for the understory vegetation were recorded. The results revealed that in total, 92 species belonging to 77 different genera and 45 families existed in the area. The largest families were Asteraceae, Rosaceae and Lamiaceae with 12, ten and nine species, respectively. Ward's agglomerative cluster analysis for tree species resulted in three floristically and ecologically distinct community types along different topographic and soil variables. Importance value indices (IVI) were also calculated for understory vegetation and were subjected to ordination techniques, i.e. canonical correspondence analysis (CCA) and detrended correspondence analysis (DCA). DCA bi-plots for stands show that most of the stands were scattered around the centre of the DCA bi-plot, identified by two slightly scattered clusters. DCA for species bi-plot clearly identified three clusters of species revealing three types of understory communities in the study area. Results of the CCA were somewhat different from the DCA showing the impact of environmental variables on the understory species. CCA results reveal that three environmental variables, i.e. altitude, slope and P (mg/kg), have a strong influence on distribution of stands and species. Impact of tree species on the understory vegetation was also tested by CCA which showed that four tree species, i.e. P. wallichiana A.B. Jackson, Juglans regia Linn., Quercus dilatata Lindl. ex Royle and Cedrus deodara (Roxb. ex Lamb.) G. Don, have strong influences on associated understory vegetation. It is therefore concluded that Swat District has various microclimatic zones with suitable environmental variables to support distinct flora.
Stephen G. Pallardy
1995-01-01
The vegetation data set of the Missouri Forest Ecosystem Project (MOFEP, initiated by the Missouri Department of Conservation) in the Ozark Mountains of southeastern Missouri was ordinated by Detrended Correspondence Analysis (DCA) to identify vegetation gradients and potential environmental influences.
Surtsey and Mount St. Helens: a comparison of early succession rates
NASA Astrophysics Data System (ADS)
del Moral, R.; Magnússon, B.
2014-04-01
Surtsey and Mount St. Helens are celebrated but very different volcanoes. Permanent plots allow for comparisons that reveal mechanisms that control succession and its rate and suggest general principles. We estimated rates from structure development, species composition using detrended correspondence analysis (DCA), changes in Euclidean distance (ED) of DCA vectors, and by principal components analysis (PCA) of DCA. On Surtsey, rates determined from DCA trajectory analyses decreased as follows: gull colony on lava with sand > gull colony on lava, no sand ≫ lava with sand > sand spit > block lava > tephra. On Mount St. Helens, plots on lahar deposits near woodlands were best developed. The succession rates of open meadows declined as follows: Lupinus-dominated pumice > protected ridge with Lupinus > other pumice and blasted sites > isolated lahar meadows > barren plain. Despite the prominent contrasts between the volcanoes, we found several common themes. Isolation restricted the number of colonists on Surtsey and to a lesser degree on Mount St. Helens. Nutrient input from outside the system was crucial. On Surtsey, seabirds fashioned very fertile substrates, while on Mount St. Helens wind brought a sparse nutrient rain, then Lupinus enhanced fertility to promote succession. Environmental stress limits succession in both cases. On Surtsey, bare lava, compacted tephra and infertile sands restrict development. On Mount St. Helens, exposure to wind and infertility slow succession.
Surtsey and Mount St. Helens: a comparison of early succession rates
NASA Astrophysics Data System (ADS)
del Moral, R.; Magnússon, B.
2013-12-01
Surtsey and Mount St. Helens are celebrated, but very different volcanoes. Permanent plots allow comparisons that reveal mechanisms that control succession and its rate and suggest general principles. We estimated rates from structure development, species composition using detrended correspondence analysis (DCA), changes in Euclidean distance (ED) of DCA vectors and by principal components analysis (PCA) of DCA. On Surtsey, rates determined from DCA trajectory analyses decreased as follows: gull colony on lava with sand > gull colony on lava, no sand ≫ lava with sand > sand spit > block lava > tephra. On Mount St. Helens, plots on lahar deposits near woodlands were best developed. The succession rates of open meadows declined as follows: Lupinus-dominated pumice > protected ridge with Lupinus > other pumice and blasted sites > isolated lahar meadows > barren plain. Despite the prominent contrasts between the volcanoes, common themes were revealed. Isolation restricted the number of colonists on Surtsey and to a lesser degree on Mount St. Helens. Nutrient input from outside the system was crucial. On Surtsey, seabirds fashioned very fertile substrates, while on Mount St. Helens wind brought a sparse nutrient rain, then Lupinus enhanced fertility to promote succession. Environmental stress limits succession in both cases. On Surtsey, bare lava, compacted tephra and infertile sands restrict development. On Mount St. Helens, exposure to wind and infertility slow succession.
Sparse Covariance Matrix Estimation by DCA-Based Algorithms.
Phan, Duy Nhat; Le Thi, Hoai An; Dinh, Tao Pham
2017-11-01
This letter proposes a novel approach using the [Formula: see text]-norm regularization for the sparse covariance matrix estimation (SCME) problem. The objective function of SCME problem is composed of a nonconvex part and the [Formula: see text] term, which is discontinuous and difficult to tackle. Appropriate DC (difference of convex functions) approximations of [Formula: see text]-norm are used that result in approximation SCME problems that are still nonconvex. DC programming and DCA (DC algorithm), powerful tools in nonconvex programming framework, are investigated. Two DC formulations are proposed and corresponding DCA schemes developed. Two applications of the SCME problem that are considered are classification via sparse quadratic discriminant analysis and portfolio optimization. A careful empirical experiment is performed through simulated and real data sets to study the performance of the proposed algorithms. Numerical results showed their efficiency and their superiority compared with seven state-of-the-art methods.
Fish assemblages at 16 sites in the upper French Broad River basin, North Carolina were related to environmental variables using detrended correspondence analysis (DCA) and linear regression. This study was conducted at the landscape scale because regional variables are controlle...
A biologically based mathematical model for the induction of liver tumors in mice by dichloroacetic acid (DCA) has been developed from histopathologic analysis of the livers of exposed mice. This analysis suggests that following chronic exposure to DCA, carcinomas can arise dire...
Matsuhashi, Tomohiro; Hishiki, Takako; Zhou, Heping; Ono, Tomohiko; Kaneda, Ruri; Iso, Tatsuya; Yamaguchi, Aiko; Endo, Jin; Katsumata, Yoshinori; Atsushi, Anzai; Yamamoto, Tsunehisa; Shirakawa, Kohsuke; Yan, Xiaoxiang; Shinmura, Ken; Suematsu, Makoto; Fukuda, Keiichi; Sano, Motoaki
2015-05-01
Dichloroacetate (DCA) promotes pyruvate entry into the Krebs cycle by inhibiting pyruvate dehydrogenase (PDH) kinase and thereby maintaining PDH in the active dephosphorylated state. DCA has recently gained attention as a potential metabolic-targeting therapy for heart failure but the molecular basis of the therapeutic effect of DCA in the heart remains a mystery. Once-daily oral administration of DCA alleviates pressure overload-induced left ventricular remodeling. We examined changes in the metabolic fate of pyruvate carbon (derived from glucose) entering the Krebs cycle by metabolic interventions of DCA. (13)C6-glucose pathway tracing analysis revealed that instead of being completely oxidized in the mitochondria for ATP production, DCA-mediated PDH dephosphorylation results in an increased acetyl-CoA pool both in control and pressure-overloaded hearts. DCA induces hyperacetylation of histone H3K9 and H4 in a dose-dependent manner in parallel to the dephosphorylation of PDH in cultured cardiomyocytes. DCA administration increases histone H3K9 acetylation in in vivo mouse heart. Interestingly, DCA-dependent histone acetylation was associated with an up-regulation of 2.3% of genes (545 out of 23,474 examined). Gene ontology analysis revealed that these genes are highly enriched in transcription-related categories. This evidence suggests that sustained activation of PDH by DCA results in an overproduction of acetyl-CoA, which exceeds oxidation in the Krebs cycle and results in histone acetylation. We propose that DCA-mediated PDH activation has the potential to induce epigenetic remodeling in the heart, which, at least in part, forms the molecular basis for the therapeutic effect of DCA in the heart. Copyright © 2015 Elsevier Ltd. All rights reserved.
SuperDCA for genome-wide epistasis analysis.
Puranen, Santeri; Pesonen, Maiju; Pensar, Johan; Xu, Ying Ying; Lees, John A; Bentley, Stephen D; Croucher, Nicholas J; Corander, Jukka
2018-05-29
The potential for genome-wide modelling of epistasis has recently surfaced given the possibility of sequencing densely sampled populations and the emerging families of statistical interaction models. Direct coupling analysis (DCA) has previously been shown to yield valuable predictions for single protein structures, and has recently been extended to genome-wide analysis of bacteria, identifying novel interactions in the co-evolution between resistance, virulence and core genome elements. However, earlier computational DCA methods have not been scalable to enable model fitting simultaneously to 10 4 -10 5 polymorphisms, representing the amount of core genomic variation observed in analyses of many bacterial species. Here, we introduce a novel inference method (SuperDCA) that employs a new scoring principle, efficient parallelization, optimization and filtering on phylogenetic information to achieve scalability for up to 10 5 polymorphisms. Using two large population samples of Streptococcus pneumoniae, we demonstrate the ability of SuperDCA to make additional significant biological findings about this major human pathogen. We also show that our method can uncover signals of selection that are not detectable by genome-wide association analysis, even though our analysis does not require phenotypic measurements. SuperDCA, thus, holds considerable potential in building understanding about numerous organisms at a systems biological level.
Monte Carlo decision curve analysis using aggregate data.
Hozo, Iztok; Tsalatsanis, Athanasios; Djulbegovic, Benjamin
2017-02-01
Decision curve analysis (DCA) is an increasingly used method for evaluating diagnostic tests and predictive models, but its application requires individual patient data. The Monte Carlo (MC) method can be used to simulate probabilities and outcomes of individual patients and offers an attractive option for application of DCA. We constructed a MC decision model to simulate individual probabilities of outcomes of interest. These probabilities were contrasted against the threshold probability at which a decision-maker is indifferent between key management strategies: treat all, treat none or use predictive model to guide treatment. We compared the results of DCA with MC simulated data against the results of DCA based on actual individual patient data for three decision models published in the literature: (i) statins for primary prevention of cardiovascular disease, (ii) hospice referral for terminally ill patients and (iii) prostate cancer surgery. The results of MC DCA and patient data DCA were identical. To the extent that patient data DCA were used to inform decisions about statin use, referral to hospice or prostate surgery, the results indicate that MC DCA could have also been used. As long as the aggregate parameters on distribution of the probability of outcomes and treatment effects are accurately described in the published reports, the MC DCA will generate indistinguishable results from individual patient data DCA. We provide a simple, easy-to-use model, which can facilitate wider use of DCA and better evaluation of diagnostic tests and predictive models that rely only on aggregate data reported in the literature. © 2017 Stichting European Society for Clinical Investigation Journal Foundation.
RENEB intercomparisons applying the conventional Dicentric Chromosome Assay (DCA).
Oestreicher, Ursula; Samaga, Daniel; Ainsbury, Elizabeth; Antunes, Ana Catarina; Baeyens, Ans; Barrios, Leonardo; Beinke, Christina; Beukes, Philip; Blakely, William F; Cucu, Alexandra; De Amicis, Andrea; Depuydt, Julie; De Sanctis, Stefania; Di Giorgio, Marina; Dobos, Katalin; Dominguez, Inmaculada; Duy, Pham Ngoc; Espinoza, Marco E; Flegal, Farrah N; Figel, Markus; Garcia, Omar; Monteiro Gil, Octávia; Gregoire, Eric; Guerrero-Carbajal, C; Güçlü, İnci; Hadjidekova, Valeria; Hande, Prakash; Kulka, Ulrike; Lemon, Jennifer; Lindholm, Carita; Lista, Florigio; Lumniczky, Katalin; Martinez-Lopez, Wilner; Maznyk, Nataliya; Meschini, Roberta; M'kacher, Radia; Montoro, Alegria; Moquet, Jayne; Moreno, Mercedes; Noditi, Mihaela; Pajic, Jelena; Radl, Analía; Ricoul, Michelle; Romm, Horst; Roy, Laurence; Sabatier, Laure; Sebastià, Natividad; Slabbert, Jacobus; Sommer, Sylwester; Stuck Oliveira, Monica; Subramanian, Uma; Suto, Yumiko; Que, Tran; Testa, Antonella; Terzoudi, Georgia; Vral, Anne; Wilkins, Ruth; Yanti, LusiYanti; Zafiropoulos, Demetre; Wojcik, Andrzej
2017-01-01
Two quality controlled inter-laboratory exercises were organized within the EU project 'Realizing the European Network of Biodosimetry (RENEB)' to further optimize the dicentric chromosome assay (DCA) and to identify needs for training and harmonization activities within the RENEB network. The general study design included blood shipment, sample processing, analysis of chromosome aberrations and radiation dose assessment. After manual scoring of dicentric chromosomes in different cell numbers dose estimations and corresponding 95% confidence intervals were submitted by the participants. The shipment of blood samples to the partners in the European Community (EU) were performed successfully. Outside the EU unacceptable delays occurred. The results of the dose estimation demonstrate a very successful classification of the blood samples in medically relevant groups. In comparison to the 1st exercise the 2nd intercomparison showed an improvement in the accuracy of dose estimations especially for the high dose point. In case of a large-scale radiological incident, the pooling of ressources by networks can enhance the rapid classification of individuals in medically relevant treatment groups based on the DCA. The performance of the RENEB network as a whole has clearly benefited from harmonization processes and specific training activities for the network partners.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tang, Shuiquan; Wang, Po Hsiang; Higgins, Steven A.
Here we report that the genomes of two closely related Dehalobacter strains (strain CF and strain DCA) were assembled from the metagenome of an anaerobic enrichment culture that reductively dechlorinates chloroform (CF), 1,1,1-trichloroethane (1,1,1-TCA) and 1,1-dichloroethane (1,1-DCA). The 3.1 Mbp genomes of strain CF (that dechlorinates CF and 1,1,1-TCA) and strain DCA (that dechlorinates 1,1-DCA) each contain 17 putative reductive dehalogenase homologous (rdh) genes. These two genomes were systematically compared to three other available organohalide-respiring Dehalobacter genomes (Dehalobacter restrictus strain PER-K23, Dehalobacter sp. strain E1 and Dehalobacter sp. strain UNSWDHB), and to the genomes of Dehalococcoides mccartyi strain 195 andmore » Desulfitobacterium hafniense strain Y51. This analysis compared 42 different metabolic and physiological categories. The genomes of strains CF and DCA share 90% overall average nucleotide identity and >99.8% identity over a 2.9 Mbp alignment that excludes large insertions, indicating that these genomes differentiated from a close common ancestor. This differentiation was likely driven by selection pressures around two orthologous reductive dehalogenase genes, cfrA and dcrA, that code for the enzymes that reduce CF or 1,1,1-TCA and 1,1-DCA. The many reductive dehalogenase genes found in the five Dehalobacter genomes cluster into two small conserved regions and were often associated with Crp/Fnr transcriptional regulators. Specialization is on-going on a strain-specific basis, as some strains but not others have lost essential genes in the Wood-Ljungdahl (strain E1) and corrinoid biosynthesis pathways (strains E1 and PER-K23). The gene encoding phosphoserine phosphatase, which catalyzes the last step of serine biosynthesis, is missing from all five Dehalobacter genomes, yet D. restrictus can grow without serine, suggesting an alternative or unrecognized biosynthesis route exists. In contrast to D. mccartyi, a complete heme biosynthesis pathway is present in the five Dehalobacter genomes. This pathway corresponds to a newly described alternative heme biosynthesis route first identified in Archaea. Ultimately, this analysis of organohalide-respiring Firmicutes and Chloroflexi reveals profound evolutionary differences despite very similar niche-specific metabolism and function.« less
Tang, Shuiquan; Wang, Po Hsiang; Higgins, Steven A.; ...
2016-02-12
Here we report that the genomes of two closely related Dehalobacter strains (strain CF and strain DCA) were assembled from the metagenome of an anaerobic enrichment culture that reductively dechlorinates chloroform (CF), 1,1,1-trichloroethane (1,1,1-TCA) and 1,1-dichloroethane (1,1-DCA). The 3.1 Mbp genomes of strain CF (that dechlorinates CF and 1,1,1-TCA) and strain DCA (that dechlorinates 1,1-DCA) each contain 17 putative reductive dehalogenase homologous (rdh) genes. These two genomes were systematically compared to three other available organohalide-respiring Dehalobacter genomes (Dehalobacter restrictus strain PER-K23, Dehalobacter sp. strain E1 and Dehalobacter sp. strain UNSWDHB), and to the genomes of Dehalococcoides mccartyi strain 195 andmore » Desulfitobacterium hafniense strain Y51. This analysis compared 42 different metabolic and physiological categories. The genomes of strains CF and DCA share 90% overall average nucleotide identity and >99.8% identity over a 2.9 Mbp alignment that excludes large insertions, indicating that these genomes differentiated from a close common ancestor. This differentiation was likely driven by selection pressures around two orthologous reductive dehalogenase genes, cfrA and dcrA, that code for the enzymes that reduce CF or 1,1,1-TCA and 1,1-DCA. The many reductive dehalogenase genes found in the five Dehalobacter genomes cluster into two small conserved regions and were often associated with Crp/Fnr transcriptional regulators. Specialization is on-going on a strain-specific basis, as some strains but not others have lost essential genes in the Wood-Ljungdahl (strain E1) and corrinoid biosynthesis pathways (strains E1 and PER-K23). The gene encoding phosphoserine phosphatase, which catalyzes the last step of serine biosynthesis, is missing from all five Dehalobacter genomes, yet D. restrictus can grow without serine, suggesting an alternative or unrecognized biosynthesis route exists. In contrast to D. mccartyi, a complete heme biosynthesis pathway is present in the five Dehalobacter genomes. This pathway corresponds to a newly described alternative heme biosynthesis route first identified in Archaea. Ultimately, this analysis of organohalide-respiring Firmicutes and Chloroflexi reveals profound evolutionary differences despite very similar niche-specific metabolism and function.« less
Cheng, Zhan-Hong; Zhang, Jin-Tun
2005-09-01
The relationship between tourism development and vegetated landscapes is analyzed for the Luya Mountain Nature Reserve (LMNR), Shanxi, China, in this study. Indices such as Sensitive Level (SL), Landscape Importance Value (LIV), information index of biodiversity (H'), Shade-tolerant Species Proportion (SSP), and Tourism Influencing Index (TII) are used to characterize vegetated landscapes, the impact of tourism, and their relationship. Their relationship is studied by Two-Way Indicator Species Analysis (TWINSPAN) and Detrended Correspondence Analysis (DCA). TWINSPAN gives correct and rapid partition to the classification, and DCA ordination shows the changing tendency of all vegetation types based on tourism development. These results reflect the ecological relationship between tourism development and vegetated landscapes. In Luya Mountain Nature Reserve, most plant communities are in good or medium condition, which shows that these vegetated landscapes can support more tourism. However, the occurrence of the bad condition shows that there is a severe contradiction between tourism development and vegetated landscapes.
NASA Astrophysics Data System (ADS)
Rovey, Joshua Lucas
Ion thrusters are high-efficiency, high-specific impulse space propulsion systems proposed for deep space missions requiring thruster operational lifetimes of 7--14 years. One of the primary ion thruster components is the discharge cathode assembly (DCA). The DCA initiates and sustains ion thruster operation. Contemporary ion thrusters utilize one molybdenum keeper DCA that lasts only ˜30,000 hours (˜3 years), so single-DCA ion thrusters are incapable of satisfying the mission requirements. The aim of this work is to develop an ion thruster that sequentially operates multiple DCAs to increase thruster lifetime. If a single-DCA ion thruster can operate 3 years, then perhaps a triple-DCA thruster can operate 9 years. Initially, a multiple-cathode discharge chamber (MCDC) is designed and fabricated. Performance curves and grid-plane current uniformity indicate operation similar to other thrusters. Specifically, the configuration that balances both performance and uniformity provides a production cost of 194 W/A at 89% propellant efficiency with a flatness parameter of 0.55. One of the primary MCDC concerns is the effect an operating DCA has on the two dormant cathodes. Multiple experiments are conducted to determine plasma properties throughout the MCDC and near the dormant cathodes, including using "dummy" cathodes outfitted with plasma diagnostics and internal plasma property mapping. Results are utilized in an erosion analysis that suggests dormant cathodes suffer a maximum pre-operation erosion rate of 5--15 mum/khr (active DCA maximum erosion is 70 mum/khr). Lifetime predictions indicate that triple-DCA MCDC lifetime is approximately 2.5 times longer than a single-DCA thruster. Also, utilization of new keeper materials, such as carbon graphite, may significantly decrease both active and dormant cathode erosion, leading to a further increase in thruster lifetime. Finally, a theory based on the near-DCA plasma potential structure and propellant flow rate effects is developed to explain active DCA erosion. The near-DCA electric field pulls ions into the DCA such that they bombard and erode the keeper. Charge-exchange collisions between bombarding ions and DCA-expelled neutral atoms reduce erosion. The theory explains ion thruster long-duration wear-test results and suggests increasing propellant flow rate may eliminate or reduce DCA erosion.
MICROARRAY ANALYSIS OF DICHLOROACETIC ACID-INDUCED CHANGES IN GENE EXPRESSION
MICROARRAY ANALYSIS OF DICHLOROACETIC ACID-INDUCED CHANGES IN GENE EXPRESSION
Dichloroacetic acid (DCA) is a major by-product of water disinfection by chlorination. Several studies have demonstrated the hepatocarcinogenicity of DCA in rodents when administered in dri...
Yan, Zhaowei; Xiong, Jianbin; Zhao, Chunyang; Qin, Chenhao; He, Chunyan
2015-01-01
Background: The aim of this experimental study was to evaluate the effect of intra-articular injection of Deoxycholic acid (DCA) on articular cartilage and subchondral bone following induction of knee Osteoarthritis (OA) in a rat model. Methods: Twenty-four Sprague Dawley rats were randomized divided into 4 groups (n = 6). Eighteen of the 24 rats underwent surgical destabilization of the medial meniscus on the right knee joints to induce OA, were divided into 3 groups: DCA 30 mg/kg group, DCA 120 mg/kg group and OA group. The rats in DCA-treated groups were given intra-articular injections of DCA (30 mg/kg or 120 mg/kg) in the operated knees once per 3 days for 42 days. The rats in OA group given intra-articular injections of vehicle alone in the operated knees under the same conditions. The remaining 6 rats (sham-operation group) received sham operations on the right knee joints. 45 days postoperatively, all of the animals were euthanized for macroscopic, histological and radiographic analysis to evaluate the effect of DCA on OA and to determine its potential mechanisms. Results: The results showed that DCA attenuated the severity of OA by reducing macroscopic observation sores for femoral condyles and histological sores for articular cartilage. DCA also significantly decreased bone destruction and erosion of joint evaluated by radiographic examination. Furthermore, DCA could markedly reduce the release of MMP-1, MMP-3 and IL-1β in serum. Conclusions: Intra-articular injection of DCA is beneficial for knee OA. It might repair and protect OA cartilage by delaying cartilage degeneration and impairing the function of inflammatory mediators. These findings highlight DCA might be a useful therapeutic agent for OA. PMID:26309557
Hupp, C.R.; Rinaldi, M.
2007-01-01
Riparian vegetation distribution patterns and diversity relative to various fluvial geomorphic channel patterns, landforms, and processes are described and interpreted for selected rivers of Tuscany, Central Italy; with emphasis on channel evolution following human impacts. Field surveys were conducted along thirteen gauged reaches for species presence, fluvial landforms, and the type and amount of channel/riparian zone change. Inundation frequency of different geomorphic surfaces was determined, and vegetation data were analyzed using BDA (binary discriminate analysis) and DCA (detrended correspondence analysis) and related to hydrogeomorphology. Multivariate analyses revealed distinct quantitative vegetation patterns relative to six major fluvial geomorphic surfaces. DCA of the vegetation data also showed distinct associations of plants to processes of adjustment that are related to stage of channel evolution, and clearly separated plants along disturbance/landform/soil moisture gradients. Species richness increases from the channel bed to the terrace and on heterogeneous riparian areas, whereas species richness decreases from moderate to intense incision and from low to intense narrowing. ?? 2007 by Association of American Geographers.
Jahediesfanjani, Hossein
2017-07-17
IntroductionIn the decline curve analysis (DCA) method of estimating recoverable hydrocarbon volumes, the analyst uses historical production data from a well, lease, group of wells (or pattern), or reservoir and plots production rates against time or cumulative production for the analysis. The DCA of an individual well is founded on the same basis as the fluid-flow principles that are used for pressure-transient analysis of a single well in a reservoir domain and therefore can provide scientifically reasonable and accurate results. However, when used for a group of wells, a lease, or a reservoir, the DCA becomes more of an empirical method. Plots from the DCA reflect the reservoir response to the oil withdrawal (or production) under the prevailing operating and reservoir conditions, and they continue to be good tools for estimating recoverable hydrocarbon volumes and future production rates. For predicting the total recoverable hydrocarbon volume, the DCA results can help the analyst to evaluate the reservoir performance under any of the three phases of reservoir productive life—primary, secondary (waterflood), or tertiary (enhanced oil recovery) phases—so long as the historical production data are sufficient to establish decline trends at the end of the three phases.
Lindh, Christian H; Littorin, Margareta; Amilon, Asa; Jönsson, Bo A G
2007-01-01
The fungicides vinclozolin and iprodione are widely used in agriculture. These pesticides are dicarboximide fungicides containing the common moiety 3,5-dichloroaniline (3,5-DCA). It has been suggested that low-level exposures to such compounds may be associated with adverse health effects such as endocrine disruption. In this study a method using liquid chromatography/triple quadrupole mass spectrometry (LC/MS/MS) was developed for the analysis of 3,5-DCA as a biomarker of exposure to these fungicides in human urine. The urine samples were treated by basic hydrolysis to degrade the fungicides, their metabolites and conjugates to 3,5-DCA. The 3,5-DCA was then extracted using toluene and derivatized using pentafluoropropionic anhydride (PFPA). Analysis of the derivative was carried out using selected reaction monitoring (SRM) in the negative ion mode. Quantification of the derivative was performed using [(13)C(6)]-labeled 3,4-DCA as an internal standard with good precision and linearity in the range 0.1-200 ng/mL urine. The limit of detection was determined to be 0.1 ng/mL. The metabolites in urine were found to be stable during storage at -20 degrees C. To validate 3,5-DCA as a biomarker the method was applied in a human experimental exposure to iprodione and vinclozolin. Two healthy volunteers received 200 microg single oral doses of each pesticide followed by urine sampling during 72-120 h post-exposure. Between 78-107% of the dose was recovered as 3,5-DCA in the urine after exposure. Copyright (c) 2007 John Wiley & Sons, Ltd.
Identification and Characterization of Daurichromenic Acid Synthase Active in Anti-HIV Biosynthesis.
Iijima, Miu; Munakata, Ryosuke; Takahashi, Hironobu; Kenmoku, Hiromichi; Nakagawa, Ryuichi; Kodama, Takeshi; Asakawa, Yoshinori; Abe, Ikuro; Yazaki, Kazufumi; Kurosaki, Fumiya; Taura, Futoshi
2017-08-01
Daurichromenic acid (DCA) synthase catalyzes the oxidative cyclization of grifolic acid to produce DCA, an anti-HIV meroterpenoid isolated from Rhododendron dauricum We identified a novel cDNA encoding DCA synthase by transcriptome-based screening from young leaves of R. dauricum The gene coded for a 533-amino acid polypeptide with moderate homologies to flavin adenine dinucleotide oxidases from other plants. The primary structure contained an amino-terminal signal peptide and conserved amino acid residues to form bicovalent linkage to the flavin adenine dinucleotide isoalloxazine ring at histidine-112 and cysteine-175. In addition, the recombinant DCA synthase, purified from the culture supernatant of transgenic Pichia pastoris , exhibited structural and functional properties as a flavoprotein. The reaction mechanism of DCA synthase characterized herein partly shares a similarity with those of cannabinoid synthases from Cannabis sativa , whereas DCA synthase catalyzes a novel cyclization reaction of the farnesyl moiety of a meroterpenoid natural product of plant origin. Moreover, in this study, we present evidence that DCA is biosynthesized and accumulated specifically in the glandular scales, on the surface of R. dauricum plants, based on various analytical studies at the chemical, biochemical, and molecular levels. The extracellular localization of DCA also was confirmed by a confocal microscopic analysis of its autofluorescence. These data highlight the unique feature of DCA: the final step of biosynthesis is completed in apoplastic space, and it is highly accumulated outside the scale cells. © 2017 American Society of Plant Biologists. All Rights Reserved.
Hozo, Iztok; Tsalatsanis, Athanasios; Djulbegovic, Benjamin
2018-02-01
Decision curve analysis (DCA) is a widely used method for evaluating diagnostic tests and predictive models. It was developed based on expected utility theory (EUT) and has been reformulated using expected regret theory (ERG). Under certain circumstances, these 2 formulations yield different results. Here we describe these situations and explain the variation. We compare the derivations of the EUT- and ERG-based formulations of DCA for a typical medical decision problem: "treat none," "treat all," or "use model" to guide treatment. We illustrate the differences between the 2 formulations when applied to the following clinical question: at which probability of death we should refer a terminally ill patient to hospice? Both DCA formulations yielded identical but mirrored results when treatment effects are ignored; they generated significantly different results otherwise. Treatment effect has a significant effect on the results derived by EUT DCA and less so on ERG DCA. The elicitation of specific values for disutilities affected the results even more significantly in the context of EUT DCA, whereas no such elicitation was required within the ERG framework. EUT and ERG DCA generate different results when treatment effects are taken into account. The magnitude of the difference depends on the effect of treatment and the disutilities associated with disease and treatment effects. This is important to realize as the current practice guidelines are uniformly based on EUT; the same recommendations can significantly differ if they are derived based on ERG framework. © 2016 The Authors. Journal of Evaluation in Clinical Practice Published by John Wiley & Sons Ltd.
Hozo, Iztok; Tsalatsanis, Athanasios
2016-01-01
Abstract Rationale, aims, and objectives Decision curve analysis (DCA) is a widely used method for evaluating diagnostic tests and predictive models. It was developed based on expected utility theory (EUT) and has been reformulated using expected regret theory (ERG). Under certain circumstances, these 2 formulations yield different results. Here we describe these situations and explain the variation. Methods We compare the derivations of the EUT‐ and ERG‐based formulations of DCA for a typical medical decision problem: “treat none,” “treat all,” or “use model” to guide treatment. We illustrate the differences between the 2 formulations when applied to the following clinical question: at which probability of death we should refer a terminally ill patient to hospice? Results Both DCA formulations yielded identical but mirrored results when treatment effects are ignored; they generated significantly different results otherwise. Treatment effect has a significant effect on the results derived by EUT DCA and less so on ERG DCA. The elicitation of specific values for disutilities affected the results even more significantly in the context of EUT DCA, whereas no such elicitation was required within the ERG framework. Conclusion EUT and ERG DCA generate different results when treatment effects are taken into account. The magnitude of the difference depends on the effect of treatment and the disutilities associated with disease and treatment effects. This is important to realize as the current practice guidelines are uniformly based on EUT; the same recommendations can significantly differ if they are derived based on ERG framework. PMID:27981695
Ramakumar, Adarsh; Subramanian, Uma; Prasanna, Pataje G S
2015-11-01
High-throughput individual diagnostic dose assessment is essential for medical management of radiation-exposed subjects after a mass casualty. Cytogenetic assays such as the Dicentric Chromosome Assay (DCA) are recognized as the gold standard by international regulatory authorities. DCA is a multi-step and multi-day bioassay. DCA, as described in the IAEA manual, can be used to assess dose up to 4-6 weeks post-exposure quite accurately but throughput is still a major issue and automation is very essential. The throughput is limited, both in terms of sample preparation as well as analysis of chromosome aberrations. Thus, there is a need to design and develop novel solutions that could utilize extensive laboratory automation for sample preparation, and bioinformatics approaches for chromosome-aberration analysis to overcome throughput issues. We have transitioned the bench-based cytogenetic DCA to a coherent process performing high-throughput automated biodosimetry for individual dose assessment ensuring quality control (QC) and quality assurance (QA) aspects in accordance with international harmonized protocols. A Laboratory Information Management System (LIMS) is designed, implemented and adapted to manage increased sample processing capacity, develop and maintain standard operating procedures (SOP) for robotic instruments, avoid data transcription errors during processing, and automate analysis of chromosome-aberrations using an image analysis platform. Our efforts described in this paper intend to bridge the current technological gaps and enhance the potential application of DCA for a dose-based stratification of subjects following a mass casualty. This paper describes one such potential integrated automated laboratory system and functional evolution of the classical DCA towards increasing critically needed throughput. Published by Elsevier B.V.
Screen for soil fungi highly resistant to dichloroaniline uncovers mostly Fusarium species.
Chan Ho Tong, Laetitia; Dairou, Julien; Bui, Linh-Chi; Bouillon, Julien; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Silar, Philippe
2015-08-01
Arylamines are frequent pollutants in soils. Fungi have proven to be efficient in detoxifying these chemicals by acetylating them using arylamine N-acetyl transferase enzymes. Here, we selected from natural soils fungi highly resistant to 3,4-dichloroaniline (DCA). Fusarium species were the most frequently isolated species, especially Fusarium solani. The sequenced strain of F. solani contains five NAT genes, as did all the DCA-resistant isolates. RT-PCR analysis showed that the five genes were expressed in F. solani. Expression of the F. solani genes in Podospora anserina and analysis of acetylation directly in F. solani showed that only the NhNAT2B gene conferred significant resistance to DCA and that F. solani likely uses pathways different from acetylation to resist high doses of DCA, as observed previously for Trichoderma. Copyright © 2015 Elsevier Inc. All rights reserved.
Kopriva, Ivica; Persin, Antun; Puizina-Ivić, Neira; Mirić, Lina
2010-07-02
This study was designed to demonstrate robust performance of the novel dependent component analysis (DCA)-based approach to demarcation of the basal cell carcinoma (BCC) through unsupervised decomposition of the red-green-blue (RGB) fluorescent image of the BCC. Robustness to intensity fluctuation is due to the scale invariance property of DCA algorithms, which exploit spectral and spatial diversities between the BCC and the surrounding tissue. Used filtering-based DCA approach represents an extension of the independent component analysis (ICA) and is necessary in order to account for statistical dependence that is induced by spectral similarity between the BCC and surrounding tissue. This generates weak edges what represents a challenge for other segmentation methods as well. By comparative performance analysis with state-of-the-art image segmentation methods such as active contours (level set), K-means clustering, non-negative matrix factorization, ICA and ratio imaging we experimentally demonstrate good performance of DCA-based BCC demarcation in two demanding scenarios where intensity of the fluorescent image has been varied almost two orders of magnitude. Copyright 2010 Elsevier B.V. All rights reserved.
Dichloroacetate treatment for mitochondrial cytopathy: long-term effects in MELAS.
Mori, Masato; Yamagata, Takanori; Goto, Tamako; Saito, Shigeko; Momoi, Mariko Y
2004-10-01
The long-term effects of the sodium salt of dichloroacetic acid (DCA) were evaluated in four patients with mitochondrial encephalomyelopathy with lactic acidosis and stroke-like episodes (MELAS) carrying A3243G mutation. Oral administration of DCA in MELAS patients was followed for an average of 5 years 4 months. Serum levels of lactate and pyruvate were maintained at around 10 and 0.6 mg/dl, respectively. Serum levels of DCA were 40-136 microg/ml. Symptoms responding to treatment included persistent headache, abdominal pain, muscle weakness, and stroke-like episodes. In contrast, no improvements in mental status, deafness, short stature, or neuroelectrophysiological findings were observed. Adverse effects included mild liver dysfunction in all patients, hypocalcemia in three and peripheral neuropathy in one. None of these adverse events was severe enough to require discontinuation of treatment. To determine suitable indications for DCA therapy, analysis of many more patients who have undergone DCA administration is required.
Derivative component analysis for mass spectral serum proteomic profiles.
Han, Henry
2014-01-01
As a promising way to transform medicine, mass spectrometry based proteomics technologies have seen a great progress in identifying disease biomarkers for clinical diagnosis and prognosis. However, there is a lack of effective feature selection methods that are able to capture essential data behaviors to achieve clinical level disease diagnosis. Moreover, it faces a challenge from data reproducibility, which means that no two independent studies have been found to produce same proteomic patterns. Such reproducibility issue causes the identified biomarker patterns to lose repeatability and prevents it from real clinical usage. In this work, we propose a novel machine-learning algorithm: derivative component analysis (DCA) for high-dimensional mass spectral proteomic profiles. As an implicit feature selection algorithm, derivative component analysis examines input proteomics data in a multi-resolution approach by seeking its derivatives to capture latent data characteristics and conduct de-noising. We further demonstrate DCA's advantages in disease diagnosis by viewing input proteomics data as a profile biomarker via integrating it with support vector machines to tackle the reproducibility issue, besides comparing it with state-of-the-art peers. Our results show that high-dimensional proteomics data are actually linearly separable under proposed derivative component analysis (DCA). As a novel multi-resolution feature selection algorithm, DCA not only overcomes the weakness of the traditional methods in subtle data behavior discovery, but also suggests an effective resolution to overcoming proteomics data's reproducibility problem and provides new techniques and insights in translational bioinformatics and machine learning. The DCA-based profile biomarker diagnosis makes clinical level diagnostic performances reproducible across different proteomic data, which is more robust and systematic than the existing biomarker discovery based diagnosis. Our findings demonstrate the feasibility and power of the proposed DCA-based profile biomarker diagnosis in achieving high sensitivity and conquering the data reproducibility issue in serum proteomics. Furthermore, our proposed derivative component analysis suggests the subtle data characteristics gleaning and de-noising are essential in separating true signals from red herrings for high-dimensional proteomic profiles, which can be more important than the conventional feature selection or dimension reduction. In particular, our profile biomarker diagnosis can be generalized to other omics data for derivative component analysis (DCA)'s nature of generic data analysis.
Granito, Vito Mario; Lunghini, Dario; Maggi, Oriana; Persiani, Anna Maria
2015-01-01
The authors conducted an ecological study of forests subjected to varying management. The aim of the study was to extend and integrate, within a multivariate context, knowledge of how saproxylic fungal communities behave along altitudinal/vegetational gradients in response to the varying features and quality of coarse woody debris (CWD). The intra-annual seasonal monitoring of saproxylic fungi, based on sporocarp inventories, was used to investigate saproxylic fungi in relation to vegetation types and management categories. We analyzed fungal species occurrence, recorded according to the presence/absence and frequency of sporocarps, on the basis of the harvest season, of coarse woody debris decay classes as well as other environmental and ecological variables. Two-way cluster analysis, DCA and Spearman's rank correlations, for indirect gradient analysis, were performed to identify any patterns of seasonality and decay. Most of the species were found on CWD in an intermediate decay stage. The first DCA axis revealed the vegetational/microclimate gradient as the main driver of fungal community composition, while the second axis corresponded to a strong gradient of CWD decay classes. © 2015 by The Mycological Society of America.
Cocco, Simona; Monasson, Remi; Weigt, Martin
2013-01-01
Various approaches have explored the covariation of residues in multiple-sequence alignments of homologous proteins to extract functional and structural information. Among those are principal component analysis (PCA), which identifies the most correlated groups of residues, and direct coupling analysis (DCA), a global inference method based on the maximum entropy principle, which aims at predicting residue-residue contacts. In this paper, inspired by the statistical physics of disordered systems, we introduce the Hopfield-Potts model to naturally interpolate between these two approaches. The Hopfield-Potts model allows us to identify relevant ‘patterns’ of residues from the knowledge of the eigenmodes and eigenvalues of the residue-residue correlation matrix. We show how the computation of such statistical patterns makes it possible to accurately predict residue-residue contacts with a much smaller number of parameters than DCA. This dimensional reduction allows us to avoid overfitting and to extract contact information from multiple-sequence alignments of reduced size. In addition, we show that low-eigenvalue correlation modes, discarded by PCA, are important to recover structural information: the corresponding patterns are highly localized, that is, they are concentrated in few sites, which we find to be in close contact in the three-dimensional protein fold. PMID:23990764
Calculating the Maximum Density of the Surface Packing of Ions in Ionic Liquids
NASA Astrophysics Data System (ADS)
Kislenko, S. A.; Moroz, Yu. O.; Karu, K.; Ivaništšev, V. B.; Fedorov, M. V.
2018-05-01
The maximum density of monolayer packing on a graphene surface is calculated by means of molecular dynamics (MD) for ions of characteristic size and symmetry: 1-butyl-3-methylimidazolium [BMIM]+, tetrabutylammonium [TBA]+, tetrafluoroborate [BF4]-, dicyanamide [DCA]-, and bis(trifluoromethane) sulfonimide [TFSI]-. The characteristic orientations of ions in a closely packed monolayer are found. It is shown that the formation of a closely packed monolayer is possible for [DCA]- and [BF4]- anions only at surface charges that exceed the limit of the electrochemical stability of the corresponding ionic liquids. For the [TBA]+ cation, a monolayer structure can be observed at the charge of nearly 30 μC/cm2 attainable in electrochemical experiment.
Gonzalez-Leon, A; Merdink, J L; Bull, R J; Schultz, I R
1999-12-15
Dichloroacetate (DCA) and trichloroacetate (TCA) are prominent by-products of chlorination of drinking water. Both chemicals have been shown to be hepatic carcinogens in mice. Prior work has demonstrated that DCA inhibits its own metabolism in rats and humans. This study focuses on the effect of prior administration of DCA or TCA in drinking water on the pharmacokinetics of a subsequent challenge dose of DCA or TCA in male B6C3F1 mice. Mice were provided with DCA or TCA in their drinking water at 2 g/l for 14 days and then challenged with a 100 mg/kg i.v. (non-labeled) or gavage (14C-labeled) dose of DCA or TCA. The challenge dose was administered after 16 h fasting and removal of the haloacetate pre-treatment. The haloacetate blood concentration-time profile and the disposition of 14C were characterized and compared with controls. The effect of pre-treatment on the in vitro metabolism of DCA in hepatic S9 was also evaluated. Pre-treatment with DCA caused a significant increase in the blood concentration-time profiles of the challenge dose of DCA. No effect on the blood concentration-time profile of DCA was observed after pre-treatment with TCA. Pre-treatment with TCA had no effect on subsequent doses of DCA. Pre-treatment with DCA did not have a significant effect on the formation of 14CO2 from radiolabeled DCA. In vitro experiments with liver S9 from DCA-pre-treated mice demonstrated that DCA inhibits it own metabolism. These results indicate that DCA metabolism in mice is also susceptible to inhibition by prior treatment with DCA, however the impact on clearance is less marked in mice than in F344 rats. In contrast, the metabolism and pharmacokinetics of TCA is not affected by pre-treatment with either DCA or TCA.
FreeContact: fast and free software for protein contact prediction from residue co-evolution.
Kaján, László; Hopf, Thomas A; Kalaš, Matúš; Marks, Debora S; Rost, Burkhard
2014-03-26
20 years of improved technology and growing sequences now renders residue-residue contact constraints in large protein families through correlated mutations accurate enough to drive de novo predictions of protein three-dimensional structure. The method EVfold broke new ground using mean-field Direct Coupling Analysis (EVfold-mfDCA); the method PSICOV applied a related concept by estimating a sparse inverse covariance matrix. Both methods (EVfold-mfDCA and PSICOV) are publicly available, but both require too much CPU time for interactive applications. On top, EVfold-mfDCA depends on proprietary software. Here, we present FreeContact, a fast, open source implementation of EVfold-mfDCA and PSICOV. On a test set of 140 proteins, FreeContact was almost eight times faster than PSICOV without decreasing prediction performance. The EVfold-mfDCA implementation of FreeContact was over 220 times faster than PSICOV with negligible performance decrease. EVfold-mfDCA was unavailable for testing due to its dependency on proprietary software. FreeContact is implemented as the free C++ library "libfreecontact", complete with command line tool "freecontact", as well as Perl and Python modules. All components are available as Debian packages. FreeContact supports the BioXSD format for interoperability. FreeContact provides the opportunity to compute reliable contact predictions in any environment (desktop or cloud).
Aoi, Mikio C.; Hu, Kun; Lo, Men-Tzung; Selim, Magdy; Olufsen, Mette S.; Novak, Vera
2012-01-01
Dynamic cerebral autoregulation (dCA) is impaired following stroke. However, the relationship between dCA, brain atrophy, and functional outcomes following stroke remains unclear. In this study, we aimed to determine whether impairment of dCA is associated with atrophy in specific regions or globally, thereby affecting daily functions in stroke patients. We performed a retrospective analysis of 33 subjects with chronic infarctions in the middle cerebral artery territory, and 109 age-matched non-stroke subjects. dCA was assessed via the phase relationship between arterial blood pressure and cerebral blood flow velocity. Brain tissue volumes were quantified from MRI. Functional status was assessed by gait speed, instrumental activities of daily living (IADL), modified Rankin Scale, and NIH Stroke Score. Compared to the non-stroke group, stroke subjects showed degraded dCA bilaterally, and showed gray matter atrophy in the frontal, parietal and temporal lobes ipsilateral to infarct. In stroke subjects, better dCA was associated with less temporal lobe gray matter atrophy on the infracted side ( = 0.029), faster gait speed ( = 0.018) and lower IADL score (0.002). Our results indicate that better dynamic cerebral perfusion regulation is associated with less atrophy and better long-term functional status in older adults with chronic ischemic infarctions. PMID:23071639
Genetic Relationships Among Olive (Olea europaea L.) Cultivars Native to Turkey.
Sakar, Ebru; Unver, Hulya; Bakir, Melike; Ulas, Mehmet; Sakar, Zeynep Mujde
2016-08-01
Olive is a widely cultivated, mainly in the Mediterranean region, and economically important fruit species used as both olive oil and table olive consumption. In Turkey, more than 50 olive cultivars have been authorized for commercial plantations, representing the developmental base for the olive industry. The aim of the present study was to identify genetic relationships among the most widely grown 27 olive cultivars in Turkey, using microsatellite or simple sequence repeat markers. Nine well-known foreign olive cultivars from different countries are also included in the study to compare the Turkish cultivars. To determine genetic relationship and diversity, 10 SSR loci (DCA3, DCA9, DCA15, DCA18, UDO4, UDO9, UDO11, UDO12, UDO24, UDO28) were used. Jaccard's similarity coefficient and the UPGMA method for cluster analysis were performed using the software NTSYSpc. The results showed that the number of alleles per locus ranging from 4 (UDO4, UDO9, UDO11, UDO12, DCA15) to 12 (DCA9) presenting high polymorphism. There were no identical cultivars. High similarity was shown by cultivars Maviand Adana topağı (0.754). The most genetically divergent cultivars, Domat-Meski (0.240) and Domat-NizipYağlık (0.245), were also identified.
Xiao, Wen-Jun; Ye, Ding-Wei; Yao, Xu-Dong; Zhang, Shi-Lin; Dai, Bo
2013-01-01
To compare Partin tables (PTs) 1997, 2001, and 2007 for their clinical applicability in a Chinese cohort based upon a decision curve analysis (DCA). Clinical and pathologic data of 264 consecutive Chinese patients with clinically localized prostate cancer were used. These patients underwent open radical prostatectomy between 2005 and 2011. DCA quantified the net benefit of different PT versions relating to specific threshold probabilities of established capsular penetration (ECP), seminal vesicle involvement (SVI), and lymph node involvement (LNI). Overall, ECP, SVI, and LNI were recorded in 23.1, 10.2, and 6.1%, respectively. When the threshold probability was below the prevalence for LNI and ECP predictions, the DCA favored the 2007 version versus the 1997 version for SVI. DCA indicates that for low threshold probability, decision models are useful to discriminate the performance differences of three PT versions, although net benefit differences were not apparent. For high threshold probability, there may not be an important benefit from the use of PTs and the current analysis cannot translate into meaningful net gains differences. Copyright © 2013 S. Karger AG, Basel.
Smith, Joseph M.; Mather, Martha E.
2012-01-01
Ecological indicators are science-based tools used to assess how human activities have impacted environmental resources. For monitoring and environmental assessment, existing species assemblage data can be used to make these comparisons through time or across sites. An impediment to using assemblage data, however, is that these data are complex and need to be simplified in an ecologically meaningful way. Because multivariate statistics are mathematical relationships, statistical groupings may not make ecological sense and will not have utility as indicators. Our goal was to define a process to select defensible and ecologically interpretable statistical simplifications of assemblage data in which researchers and managers can have confidence. For this, we chose a suite of statistical methods, compared the groupings that resulted from these analyses, identified convergence among groupings, then we interpreted the groupings using species and ecological guilds. When we tested this approach using a statewide stream fish dataset, not all statistical methods worked equally well. For our dataset, logistic regression (Log), detrended correspondence analysis (DCA), cluster analysis (CL), and non-metric multidimensional scaling (NMDS) provided consistent, simplified output. Specifically, the Log, DCA, CL-1, and NMDS-1 groupings were ≥60% similar to each other, overlapped with the fluvial-specialist ecological guild, and contained a common subset of species. Groupings based on number of species (e.g., Log, DCA, CL and NMDS) outperformed groupings based on abundance [e.g., principal components analysis (PCA) and Poisson regression]. Although the specific methods that worked on our test dataset have generality, here we are advocating a process (e.g., identifying convergent groupings with redundant species composition that are ecologically interpretable) rather than the automatic use of any single statistical tool. We summarize this process in step-by-step guidance for the future use of these commonly available ecological and statistical methods in preparing assemblage data for use in ecological indicators.
Composition and diversity of weed communities in Al-Jouf province, northern Saudi Arabia
Gomaa, Nasr H.
2012-01-01
The aim of this study was to identify the main weed communities in Al-Jouf province in northern Saudi Arabia. Moreover, the composition and diversity of these communities were studied in relation to soil variables and crop type. Some 54 stands representing olive orchards, date palm orchards, wheat crop and watermelon crop were studied, using ten quadrats (1 × 1 m) per stand. A total of 71 species belonging to 22 families and 61 genera were observed. The classification of vegetation using the Two Way Indicator Species Analysis (TWINSPAN) resulted in the recognition of four vegetation groups representing wheat crop, orchards in winter season, orchards in summer season and watermelon crop. These results suggested the importance of both crop and season for the formation of weed community. Detrended Correspondence Analysis (DCA) showed that these groups are clearly distinguished by the first two DCA axes. The species richness was higher in both olive and date palm orchards than in wheat and watermelon crops. This pattern of species richness could be related to farm management practices and habitat micro-heterogeneity. Soil electrical conductivity, organic carbon and soil texture showed significant correlations with species richness and the cover values of some dominant species, suggesting the significant role of soil characteristics in weed community structure and diversity. PMID:23961198
Ibekwe, A Mark; Ma, Jincai; Murinda, Shelton E
2016-10-01
Microbial communities in terrestrial fresh water are diverse and dynamic in composition due to different environmental factors. The goal of this study was to undertake a comprehensive analysis of bacterial composition along different rivers and creeks and correlate these to land-use practices and pollutant sources. Here we used 454 pyrosequencing to determine the total bacterial community composition, and bacterial communities that are potentially of fecal origin, and of relevance to water quality assessment. The results were analyzed using UniFrac coupled with principal coordinate analysis (PCoA) to compare diversity, abundance, and community composition. Detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA) were used to correlate bacterial composition in streams and creeks to different environmental parameters impacting bacterial communities in the sediment and surface water within the watershed. Bacteria were dominated by the phyla Proteobacteria, Bacteroidetes, Acidobacteria, and Actinobacteria, with Bacteroidetes significantly (P<0.001) higher in all water samples than sediment, where as Acidobacteria and Actinobacteria where significantly higher (P<0.05) in all the sediment samples than surface water. Overall results, using the β diversity measures, coupled with PCoA and DCA showed that bacterial composition in sediment and surface water was significantly different (P<0.001). Also, there were differences in bacterial community composition between agricultural runoff and urban runoff based on parsimony tests using 454 pyrosequencing data. Fecal indicator bacteria in surface water along different creeks and channels were significantly correlated with pH (P<0.01), NO2 (P<0.03), and NH4N (P<0.005); and in the sediment with NO3 (P<0.015). Our results suggest that microbial community compositions were influenced by several environmental factors, and pH, NO2, and NH4 were the major environmental factors driving FIB in surface water based on CCA analysis, while NO3 was the only factor in sediment. Published by Elsevier B.V.
Semenyutin, Vladimir B.; Asaturyan, Gregory A.; Nikiforova, Anna A.; Aliev, Vugar A.; Panuntsev, Grigory K.; Iblyaminov, Vadim B.; Savello, Alexander V.; Patzak, Andreas
2017-01-01
Dynamic cerebral autoregulation (DCA) capacity along with the degree of internal carotid artery (ICA) stenosis and characteristics of the plaque can also play an important role in selection of appropriate treatment strategy. This study aims to classify the patients with severe ICA stenosis according to preoperative state of DCA and to assess its dynamics after surgery. Thirty-five patients with severe ICA stenosis having different clinical type of disease underwent reconstructive surgery. DCA was assessed with transfer function analysis (TFA) by calculating phase shift (PS) between Mayer waves of blood flow velocity (BFV) and blood pressure (BP) before and after operation. In 18 cases, regardless of clinical type, preoperative PS on ipsilateral side was within the normal range and did not change considerably after surgery. In other 17 cases preoperative PS was reliably lower both in patients with symptomatic and asymptomatic stenosis. Surgical reconstruction led to restoration of impaired DCA evidenced by significant increase of PS in postoperative period. Our data suggest that regardless clinical type of disease various state of DCA may be present in patients with severe ICA stenosis. This finding can contribute to establishing the optimal treatment strategy, and first of all for asymptomatic patients. Patients with compromised DCA should be considered as ones with higher risk of stroke and first candidates for reconstructive surgery. PMID:29163214
Munro, Jacob E.; Liew, Elissa F.; Ly, Mai-Anh
2016-01-01
ABSTRACT 1,2-Dichloroethane (DCA) is a problematic xenobiotic groundwater pollutant. Bacteria are capable of biodegrading DCA, but the evolution of such bacteria is not well understood. In particular, the mechanisms by which bacteria acquire the key dehalogenase genes dhlA and dhlB have not been well defined. In this study, the genomic context of dhlA and dhlB was determined in three aerobic DCA-degrading bacteria (Starkeya novella strain EL1, Xanthobacter autotrophicus strain EL4, and Xanthobacter flavus strain EL8) isolated from a groundwater treatment plant (GTP). A haloalkane dehalogenase gene (dhlA) identical to the canonical dhlA gene from Xanthobacter sp. strain GJ10 was present in all three isolates, and, in each case, the dhlA gene was carried on a variant of a 37-kb circular plasmid, which was named pDCA. Sequence analysis of the repA replication initiator gene indicated that pDCA was a member of the pTAR plasmid family, related to catabolic plasmids from the Alphaproteobacteria, which enable growth on aromatics, dimethylformamide, and tartrate. Genes for plasmid replication, mobilization, and stabilization were identified, along with two insertion sequences (ISXa1 and ISPme1) which were likely to have mobilized dhlA and dhlB and played a role in the evolution of aerobic DCA-degrading bacteria. Two haloacid dehalogenase genes (dhlB1 and dhlB2) were detected in the GTP isolates; dhlB1 was most likely chromosomal and was similar to the canonical dhlB gene from strain GJ10, while dhlB2 was carried on pDCA and was not closely related to dhlB1. Heterologous expression of the DhlB2 protein confirmed that this plasmid-borne dehalogenase was capable of chloroacetate dechlorination. IMPORTANCE Earlier studies on the DCA-degrading Xanthobacter sp. strain GJ10 indicated that the key dehalogenases dhlA and dhlB were carried on a 225-kb linear plasmid and on the chromosome, respectively. The present study has found a dramatically different gene organization in more recently isolated DCA-degrading Xanthobacter strains from Australia, in which a relatively small circular plasmid (pDCA) carries both dhlA and dhlB homologs. pDCA represents a true organochlorine-catabolic plasmid, first because its only obvious metabolic phenotype is dehalogenation of organochlorines, and second because acquisition of this plasmid provides both key enzymes required for carbon-chlorine bond cleavage. The discovery of the alternative haloacid dehalogenase dhlB2 in pDCA increases the known genetic diversity of bacterial chloroacetate-hydrolyzing enzymes. PMID:27342553
Hage, J C; Van Houten, R T; Tramper, J; Hartmans, S
2004-06-01
A membrane-aerated biofilm reactor (MBR) with a biofilm of Pseudomonas sp. strain DCA1 was studied for the removal of 1,2-dichloroethane (DCA) from water. A hydrophobic membrane was used to create a barrier between the liquid and the gas phase. Inoculation of the MBR with cells of strain DCA1 grown in a continuous culture resulted in the formation of a stable and active DCA-degrading biofilm on the membrane. The maximum removal rate of the MBR was reached at a DCA concentration of approximately 80 micro M. Simulation of the DCA fluxes into the biofilm showed that the MBR performance at lower concentrations was limited by the DCA diffusion rate rather than by kinetic constraints of strain DCA1. Aerobic biodegradation of DCA present in anoxic water could be achieved by supplying oxygen solely from the gas phase to the biofilm grown on the liquid side of the membrane. As a result, direct aeration of the water, which leads to undesired coagulation of iron oxides, could be avoided.
Decision curve analysis to compare 3 versions of Partin Tables to predict final pathologic stage.
Augustin, Herbert; Sun, Maxine; Isbarn, Hendrik; Pummer, Karl; Karakiewicz, Pierre
2012-01-01
To perform a decision curve analysis (DCA) to compare the Partin Tables 1997, 2001, and 2007 for their clinical applicability. Clinical and pathologic data of 687 consecutive patients treated with open radical prostatectomy for clinically localized prostate cancer between 2003 and 2008 at a single institution were used. DCA quantified the net benefit relating to specific threshold probabilities of extraprostatic extension (EPE), seminal vesicle involvement (SVI), and lymph node involvement (LNI). Overall, EPE, SVI, and LNI were recorded in 17.8, 6.0, and 1.2%, respectively. For EPE predictions, the DCA favored the 2007 version vs. 1997 for SVI vs. none of the versions for LNI. DCA indicate that for very low prevalence conditions such as LNI (1.2%), decision models are not useful. For low prevalence rates such as SVI, the use of different versions of the Partin Tables does not translate into meaningful net gains differences. Finally, for intermediate prevalence conditions such as EPE (18%), despite apparent performance differences, the net benefit differences were also marginal. In consequence, the current analysis could not confirm an important benefit from the use of the Partin Tables and it could not identify a clearly better version of any of the 3 available iterations. Copyright © 2012 Elsevier Inc. All rights reserved.
A Quantitative Description of Suicide Inhibition of Dichloroacetic Acid in Rats and Mice
DOE Office of Scientific and Technical Information (OSTI.GOV)
Keys, Deborah A.; Schultz, Irv R.; Mahle, Deirdre A.
Dichloroacetic acid (DCA), a minor metabolite of trichloroethylene (TCE) and water disinfection byproduct, remains an important risk assessment issue because of its carcinogenic potency. DCA has been shown to inhibit its own metabolism by irreversibly inactivating glutathione transferase zeta (GSTzeta). To better predict internal dosimetry of DCA, a physiologically based pharmacokinetic (PBPK) model of DCA was developed. Suicide inhibition was described dynamically by varying the rate of maximal GSTzeta mediated metabolism of DCA (Vmax) over time. Resynthesis (zero-order) and degradation (first-order) of metabolic activity were described. Published iv pharmacokinetic studies in native rats were used to estimate an initial Vmaxmore » value, with Km set to an in vitro determined value. Degradation and resynthesis rates were set to estimated values from a published immunoreactive GSTzeta protein time course. The first-order inhibition rate, kd, was estimated to this same time course. A secondary, linear non-GSTzeta-mediated metabolic pathway is proposed to fit DCA time courses following treatment with DCA in drinking water. The PBPK model predictions were validated by comparing predicted DCA concentrations to measured concentrations in published studies of rats pretreated with DCA following iv exposure to 0.05 to 20 mg/kg DCA. The same model structure was parameterized to simulate DCA time courses following iv exposure in native and pretreated mice. Blood and liver concentrations during and postexposure to DCA in drinking water were predicted. Comparisons of PBPK model predicted to measured values were favorable, lending support for the further development of this model for application to DCA or TCE human health risk assessment.« less
Zhang, Q B; Yang, C; Hua, Y X; Li, Y; Dong, P
2015-02-14
Nanostructured lanthanum was electrochemically prepared on a platinum (Pt) substrate in the room temperature ionic liquid 1-butyl-3-methylimidazolium dicyanamide (BMI-DCA) containing anhydrous LaCl3 at 333 K. The electrochemical reduction behavior of La(iii) was investigated using cyclic voltammetry and chronoamperometry techniques. Cyclic voltammogram revealed that the reduction of La(iii) in BMI-DCA involved an irreversible process controlled by diffusion. Chronoamperometric transient analysis confirmed the diffusion controlled electrodeposition process with the diffusion coefficient of La(iii) species in the range of 10(-10) cm(2) s(-1). The strong complexing capability of DCA(-) anions facilitated the displacement of chloride ligands and induced the solubility of LaCl3. The subsequent coordination of La(iii) and DCA(-) anions forming [La(DCA)4](-) complex anions was monitored by designing amperometric titration experiments. Potentiostatically deposited La-deposits with different nanostructures were characterized by SEM, XRD and XPS analyses. The electrodeposition potential was found to play an important role in controlling the nucleation and growth kinetics of the nanocrystal during the electrodeposition process. Depending on the deposition potential, metallic lanthanum with either nanoparticles or nanoporous structures was obtained.
Allyn, Jérôme; Ferdynus, Cyril; Bohrer, Michel; Dalban, Cécile; Valance, Dorothée; Allou, Nicolas
2016-01-01
End-of-life decision-making in Intensive care Units (ICUs) is difficult. The main problems encountered are the lack of a reliable prediction score for death and the fact that the opinion of patients is rarely taken into consideration. The Decision Curve Analysis (DCA) is a recent method developed to evaluate the prediction models and which takes into account the wishes of patients (or surrogates) to expose themselves to the risk of obtaining a false result. Our objective was to evaluate the clinical usefulness, with DCA, of the Simplified Acute Physiology Score II (SAPS II) to predict ICU mortality. We conducted a retrospective cohort study from January 2011 to September 2015, in a medical-surgical 23-bed ICU at University Hospital. Performances of the SAPS II, a modified SAPS II (without AGE), and age to predict ICU mortality, were measured by a Receiver Operating Characteristic (ROC) analysis and DCA. Among the 4.370 patients admitted, 23.3% died in the ICU. Mean (standard deviation) age was 56.8 (16.7) years, and median (first-third quartile) SAPS II was 48 (34-65). Areas under ROC curves were 0.828 (0.813-0.843) for SAPS II, 0.814 (0.798-0.829) for modified SAPS II and of 0.627 (0.608-0.646) for age. DCA showed a net benefit whatever the probability threshold, especially under 0.5. DCA shows the benefits of the SAPS II to predict ICU mortality, especially when the probability threshold is low. Complementary studies are needed to define the exact role that the SAPS II can play in end-of-life decision-making in ICUs.
Allyn, Jérôme; Ferdynus, Cyril; Bohrer, Michel; Dalban, Cécile; Valance, Dorothée; Allou, Nicolas
2016-01-01
Background End-of-life decision-making in Intensive care Units (ICUs) is difficult. The main problems encountered are the lack of a reliable prediction score for death and the fact that the opinion of patients is rarely taken into consideration. The Decision Curve Analysis (DCA) is a recent method developed to evaluate the prediction models and which takes into account the wishes of patients (or surrogates) to expose themselves to the risk of obtaining a false result. Our objective was to evaluate the clinical usefulness, with DCA, of the Simplified Acute Physiology Score II (SAPS II) to predict ICU mortality. Methods We conducted a retrospective cohort study from January 2011 to September 2015, in a medical-surgical 23-bed ICU at University Hospital. Performances of the SAPS II, a modified SAPS II (without AGE), and age to predict ICU mortality, were measured by a Receiver Operating Characteristic (ROC) analysis and DCA. Results Among the 4.370 patients admitted, 23.3% died in the ICU. Mean (standard deviation) age was 56.8 (16.7) years, and median (first-third quartile) SAPS II was 48 (34–65). Areas under ROC curves were 0.828 (0.813–0.843) for SAPS II, 0.814 (0.798–0.829) for modified SAPS II and of 0.627 (0.608–0.646) for age. DCA showed a net benefit whatever the probability threshold, especially under 0.5. Conclusion DCA shows the benefits of the SAPS II to predict ICU mortality, especially when the probability threshold is low. Complementary studies are needed to define the exact role that the SAPS II can play in end-of-life decision-making in ICUs. PMID:27741304
Racine, Christopher R.; Ferguson, Travis; Preston, Debbie; Ward, Dakota; Ball, John; Anestis, Dianne; Valentovic, Monica; Rankin, Gary O.
2016-01-01
Among the mono- and dichloroanilines, 3,5-Dichloroaniline (3,5-DCA) is the most potent nephrotoxicant in vivo and in vitro. However, the role of renal biotransformation in 3,5-DCA induced nephrotoxicity is unknown. The current study was designed to determine the in vitro nephrotoxic potential of 3,5-DCA in isolated renal cortical cells (IRCC) obtained from male Fischer 344 rats, and the role of renal bioactivation and oxidative stress in 3,5-DCA nephrotoxicity. IRCC (~4 million cells/ml) from male rats were exposed to 3,5-DCA (0-1.0 mM) for up to 120 min. In IRCC, 3,5-DCA was cytotoxic at 1.0 mM by 60 min as evidenced by the increased release of lactate dehydrogenase (LDH), but 120 min was required for 3,5-DCA 0.5 mM to increase LDH release. In subsequent studies, IRCC were exposed to a pretreatment (antioxidant or enzyme inhibitor) prior to exposure to 3,5-DCA (1.0 mM) for 90 min. Cytotoxicity induced by 3,5-DCA was attenuated by pretreatment with inhibitors of flavin-containing monooxygenase (FMO; methimazole, N-octylamine), cytochrome P450 (CYP; piperonyl butoxide, metyrapone), or peroxidase (indomethacin, mercaptosuccinate) enzymes. Use of more selective CYP inhibitors suggested that the CYP 2C family contributed to 3,5-DCA bioactivation. Antioxidants (glutathione, N-acetyl-L-cysteine, α-tocopherol, ascorbate, pyruvate) also attenuated 3,5-DCA nephrotoxicity, but oxidized glutathione levels and the oxidized/reduced glutathione ratios were not increased. These results indicate that 3,5-DCA may be activated via several renal enzyme systems to toxic metabolites, and that free radicals, but not oxidative stress, contribute to 3,5-DCA induced nephrotoxicity in vitro. PMID:26808022
Sundaraganesan, N; Karpagam, J; Sebastian, S; Cornard, J P
2009-07-01
In this work, the experimental and theoretical study on molecular structure and vibrational spectra of 2,4-dichloroaniline (2,4-DCA) were studied. The Fourier transform infrared (gas phase) and Fourier transform Raman spectra of 2,4-DCA were recorded. The molecular geometry and vibrational frequencies of 2,4-DCA in the ground state were calculated by using the Hartree-Fock (HF) and density functional (DF) methods (BLYP, B3LYP and SVWN) with 6-31G(d,p) as basis set. Comparison of the observed fundamental vibrational frequencies of 2,4-DCA with calculated results by HF and density functional methods indicates that BLYP is superior to other methods for molecular vibrational problems. The difference between the observed and scaled wave number values of most of the fundamentals is very small. The electric dipole moment (micro) and the first hyperpolarizability (beta) values of the investigated molecule were computed using ab initio quantum mechanical calculations. The calculated results also show that the 2,4-DCA molecule might have microscopic nonlinear optical (NLO) behavior with non-zero values. Natural atomic charges of 2,4-DCA and 4-chloroaniline was calculated and compared. The isotropic chemical shift computed by (13)C NMR analyses also shows good agreement with experimental observations. The theoretically predicted FTIR and FT-Raman spectra of the title molecule have been constructed.
Berg, Ronan M G; Plovsing, Ronni R
2016-01-01
In sepsis, higher PaCO2 levels are associated with impaired dynamic cerebral autoregulation (dCA), which may expose the brain to hypo- and hyperperfusion during acute fluctuations in blood pressure. We hypothesised that short-term mechanical hyperventilation would dCA in critically ill patients with sepsis. Seven mechanically ventilated septic patients were included. We assessed dCA before and after 30 min of mechanical hyperventilation. Transfer function analysis of spontaneous oscillations in transcranial Doppler-based middle cerebral artery blood flow velocity (MCAv) and invasive mean arterial blood pressure was used to assess dCA. Mechanical enhance hyperventilation reduced the median PaCO2 from 5.3 (IQR, 5.0-6.5) to 4.7 (IQR, 4.2-5.1) kPa (p < 0.05). This was associated with a reduction in the median MCAv from 57 (IQR, 33-68) to 32 (IQR, 21-40) cm sec(-1) (p < 0.05). Apart from a small increase in gain in the low frequency range (2.32 [IQR 1.80-2.41] vs. 2.59 (2.40-4.64) cm mmHg(-1) sec(-1); p < 0.05), this was not associated with any enhancement in dCA. In conclusion, cerebral CO2 vasoreactivity was found to be preserved in septic patients; nevertheless, and in contrast to our working hypothesis, short-term mechanical hyperventilation did not enhance dCA.
NASA Technical Reports Server (NTRS)
Gelder, Thomas F.; Schmidt, James F.; Suder, Kenneth L.; Hathaway, Michael D.
1987-01-01
The capabilities of two stators, one with controlled-diffusion (CD) blade sections and one with double-circular-arc (DCA) blade sections, were compared. A CD stator was designed and tested that had the same chord length but half the blades of the DCA stator. The same fan rotor (tip speed, 429 m/sec; pressure ratio, 1.65) was used with each stator row. The design and analysis system is briefly described. The overall stage and rotor performances with each stator are compared, as are selected blade element data. The minimum overall efficiency decrement across the stator was approximately 1 percentage point greater with the CD balde sections than with the DCA blade sections.
NASA Technical Reports Server (NTRS)
Gelder, Thomas F.; Schmidt, James F.; Suder, Kenneth L.; Hathaway, Michael D.
1987-01-01
The capabilities of two stators, one with controlled-diffusion (CD) blade sections and one with double-circular-arc (DCA) blade sections, were compared. A CD stator was designed and tested that had the same chord length but half the blades of the DCA stator. The same fan rotor (tip speed, 429 m/sec; pressure ratio, 1.65) was used with each stator row. The design and analysis system is briefly described. The overall stage and rotor performances with each stator are compared, as are selected blade element data. The minimum overall efficiency decrement across the stator was approximately 1 percentage point greater with the CD blade sections than with the DCA blade sections.
Májer, Ferenc; Salomon, Johanna J; Sharma, Ruchika; Etzbach, Simona V; Najib, Mohd Nadzri Mohd; Keaveny, Ray; Long, Aideen; Wang, Jun; Ehrhardt, Carsten; Gilmer, John F
2012-03-01
Deoxycholic acid (DCA), a secondary bile acid (BA), and ursodeoxycholic acid (UDCA), a tertiary BA, cause opposing effects in vivo and in cell suspensions. Fluorescent analogues of DCA and UDCA could help investigate important questions about their cellular interactions and distribution. We have prepared a set of isomeric 3α- and 3β-amino analogues of UDCA and DCA and derivatised these with the discrete fluorophore, 4-nitrobenzo-2-oxa-1,3-diazol (NBD), forming the corresponding four fluorescent adducts. These absorb in the range 465-470 nm and fluoresce at approx. 535 nm. In order to determine the ability of the new fluorescent bile acids to mimic the parents, their uptake was studied using monolayers of Caco-2 cells, which are known to express multiple proteins of the organic anion-transporting peptide (OATP) subfamily of transporters. Cellular uptake was monitored over time at 4 and 37°C to distinguish between passive and active transport. All four BA analogues were taken up but in a strikingly stereo- and structure-specific manner, suggesting highly discriminatory interactions with transporter protein(s). The α-analogues of DCA and to a lesser extent UDCA were actively transported, whereas the β-analogues were not. The active transport process was saturable, with Michaelis-Menten constants for 3α-NBD DCA (5) being K(m)=42.27±12.98 μM and V(max)=2.8 ± 0.4 nmol/(mg protein*min) and for 3α-NBD UDCA (3) K(m)=28.20 ± 7.45 μM and V(max)=1.8 ± 0.2 nmol/(mg protein*min). These fluorescent bile acids are promising agents for investigating questions of bile acid biology and for detection of bile acids and related organic anion transport processes. Copyright © 2012 Elsevier Ltd. All rights reserved.
Temporal genetic structure of a drone congregation area of the giant Asian honeybee ( Apis dorsata)
NASA Astrophysics Data System (ADS)
Kraus, F. B.; Koeniger, N.; Tingek, S.; Moritz, R. F. A.
2005-12-01
The giant Asian honeybee ( Apis dorsata), like all other members of the genus Apis, has a complex mating system in which the queens and males (drones) mate at spatially defined drone congregation areas (DCAs). Here, we studied the temporal genetic structure of a DCA of A. dorsata over an 8-day time window by the genotyping of sampled drones with microsatellite markers. Analysis of the genotypic data revealed a significant genetic differentiation between 3 sampling days and indicated that the DCA was used by at least two subpopulations at all days in varying proportions. The estimation of the number of colonies which used the DCA ranged between 20 and 40 colonies per subpopulation, depending on the estimation procedure and population. The overall effective population size was estimated as high as N e=140. The DCA seems to counteract known tendencies of A. dorsata for inbreeding within colony aggregations by facilitating gene flow among subpopulations and increasing the effective population size.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kumar, Ajay; Kant, Shiva; Singh, Sukh Mahendra, E-mail: sukhmahendrasingh@yahoo.com
Targeting of tumor metabolism is emerging as a novel therapeutic strategy against cancer. Dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase (PDK), has been shown to exert a potent tumoricidal action against a variety of tumor cells. The main mode of its antineoplastic action implicates a shift of glycolysis to oxidative metabolism of glucose, leading to generation of cytotoxic reactive oxygen intermediates. However, the effect of DCA on tumor microenvironment, which in turn regulates tumor cell survival; remains speculative to a large extent. It is also unclear if DCA can exert any modulatory effect on the process of hematopoiesis, whichmore » is in a compromised state in tumor-bearing hosts undergoing chemotherapy. In view of these lacunas, the present study was undertaken to investigate the so far unexplored aspects with respect to the molecular mechanisms of DCA-dependent tumor growth retardation and chemosensitization. BALB/c mice were transplanted with Dalton's lymphoma (DL) cells, a T cell lymphoma of spontaneous origin, followed by administration of DCA with or without cisplatin. DCA-dependent tumor regression and chemosensitization to cisplatin was found to be associated with altered repertoire of key cell survival regulatory molecules, modulated glucose metabolism, accompanying reconstituted tumor microenvironment with respect to pH homeostasis, cytokine balance and alternatively activated TAM. Moreover, DCA administration also led to an alteration in the MDR phenotype of tumor cells and myelopoietic differentiation of macrophages. The findings of this study shed a new light with respect to some of the novel mechanisms underlying the antitumor action of DCA and thus may have immense clinical applications. - Highlights: • DCA modulates tumor progression and chemoresistance. • DCA alters molecules regulating cell survival, glucose metabolism and MDR. • DCA reconstitutes biophysical and cellular composition of tumor microenvironment. • DCA augments BMC cellularity, differentiation and repolarization of macrophages.« less
Zajac, Juraj; Kostrhunova, Hana; Novohradsky, Vojtech; Vrana, Oldrich; Raveendran, Raji; Gibson, Dan; Kasparkova, Jana; Brabec, Viktor
2016-03-01
The molecular and cellular mechanisms of enhanced toxic effects in tumor cells of the Pt(IV) derivatives of antitumor oxaliplatin containing axial dichloroacetate (DCA) ligands were investigated. DCA ligands were chosen because DCA has shown great potential as an apoptosis sensitizer and anticancer agent reverting the Wartburg effect. In addition, DCA reverses mitochondrial changes in a wide range of cancers, promoting tumor cell apoptosis in a mitochondrial-dependent pathway. We demonstrate that (i) the transformation of oxaliplatin to its Pt(IV) derivatives containing axial DCA ligands markedly enhances toxicity in cancer cells and helps overcome inherent and acquired resistance to cisplatin and oxaliplatin; (ii) a significant fraction of the intact molecules of DCA conjugates with Pt(IV) derivative of oxaliplatin accumulates in cancer cells where it releases free DCA; (iii) mechanism of biological action of the Pt(IV) derivatives of oxaliplatin containing DCA ligands is connected with the effects of DCA released in cancer cells from the Pt(IV) prodrugs on mitochondria and metabolism of glucose; (iv) treatments with the Pt(IV) derivatives of oxaliplatin containing DCA ligands activate an autophagic response in human colorectal cancer cells; (v) the toxic effects in cancer cells of the Pt(IV) derivatives of oxaliplatin containing DCA ligands can be potentiated if cells are treated with these prodrugs in combination with 5-fluorouracil. These properties of the Pt(IV) derivatives of oxaliplatin containing DCA ligands provide opportunities for further development of new platinum-based agents with the capability of killing cancer cells resistant to conventional antitumor platinum drugs used in the clinic. Copyright © 2015 Elsevier Inc. All rights reserved.
Human kinetics of orally and intravenously administered low-dose 1,2-(13)C-dichloroacetate.
Jia, Minghong; Coats, Bonnie; Chadha, Monisha; Frentzen, Barbara; Perez-Rodriguez, Javier; Chadik, Paul A; Yost, Richard A; Henderson, George N; Stacpoole, Peter W
2006-12-01
Dichloroacetate (DCA) is a putative environmental hazard, owing to its ubiquitous presence in the biosphere and its association with animal and human toxicity. We sought to determine the kinetics of environmentally relevant concentrations of 1,2-(13)C-DCA administered to healthy adults. Subjects received an oral or intravenous dose of 2.5 microg/kg of 1,2-(13)C-DCA. Plasma and urine concentrations of 1,2-(13)C-DCA were measured by a modified gas chromatography-tandem mass spectrometry method. 1,2-(13)C-DCA kinetics was determined by modeling using WinNonlin 4.1 software. Plasma concentrations of 1,2-(13)C-DCA peaked 10 minutes and 30 minutes after intravenous or oral administration, respectively. Plasma kinetic parameters varied as a function of dose and duration. Very little unchanged 1,2-(13)C-DCA was excreted in urine. Trace amounts of DCA alter its own kinetics after short-term exposure. These findings have important implications for interpreting the impact of this xenobiotic on human health.
Weber, Anderson; Thewes, Fabio Rodrigo; Anese, Rogerio de Oliveira; Both, Vanderlei; Pavanello, Elizandra Pivotto; Brackmann, Auri
2017-11-15
The objective of the present work was to evaluate the appropriate respiratory quotient (RQ) value to achieve a safe lowest oxygen limit (LOL), during storage of 'Fuji Suprema' apples, in dynamic controlled atmosphere (DCA), treated with or without 1-methylcyclopropene (1-MCP). The apples were stored in DCA-RQ, a new technology for storing fruits, and were compared with the HarvestWatch™, a system based on chlorophyll fluorescence DCA (DCA-CF), and static controlled atmosphere. DCA-RQ1.5 is the most suited for the storage of 'Fuji Suprema' apples. In this condition fermentative products were induced, which reduced ethylene production and respiration rate; however, it did not increase physiological disorders, and the concentration of ethyl acetate was below the odour threshold. 1-MCP application maintained higher flesh firmness and reduced the anaerobic metabolism, although it decreased fruit quality due to the occurrence of cavities, therefore its application is not recommended for 'Fuji Suprema' apple stored in DCA conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.
Dichloroacetic acid (DCA} inhibits proliferation and apoptosis in nonnal hepatocytes of
male F344 rats.
Large segments of the population are chronically exposed to dichloroacetic acid (DCA}: DCA is a by product of the chlorine disinfection of drinking water, a metab...
Viscosity, conductivity, and electrochemical property of dicyanamide ionic liquids
NASA Astrophysics Data System (ADS)
Yuan, Wen-Li; Yang, Xiao; He, Ling; Xue, Ying; Qin, Song; Tao, Guo-Hong
2018-03-01
The instructive structure-property relationships of ionic liquids (ILs) can be put to task-specific design of new functionalized ILs. The dicyanamide (DCA) ILs are typical CHN type ILs which are halogen free, chemical stable, low-viscous and fuel-rich. The transport properties of DCA ionic liquids are significant for their applications as solvents, electrolytes and hypergolic propellants. This work systematically investigates several important transport properties of four DCA ILs ([C4mim][N(CN)2], [C4m2im][N(CN)2], N4442[N(CN)2], and N8444[N(CN)2]) including viscosity, conductivity, and electrochemical property at different temperatures. The melting points, temperature-dependent viscosities and conductivities reveal the structure-activity relationship of four DCA ILs. From the Walden plots, the imidazolium cations exhibit stronger cation–anion attraction than the ammonium cations. DCA ILs have relatively high values of electrochemical windows (EWs), which indicates that the DCA ILs are potential candidates for electrolytes in electrochemical applications. The cyclic voltammograms of Eu(III) in these DCA ILs at GC working electrode at various temperatures 303–333 K consists of quasi-reversible waves. The electrochemical properties of the DCA ILs are also dominated by the cationic structures. The current intensity (ip), the diffusion coefficients (Do), the charge transfer rate constants (ks) of Eu(III) in DCA ILs all increased with the molar conductivities increased. The cationic structure-transport property relationships of DCA ILs were constructed for designing novel functionalized ILs to fulfill specific demands.
Viscosity, Conductivity, and Electrochemical Property of Dicyanamide Ionic Liquids
Yuan, Wen-Li; Yang, Xiao; He, Ling; Xue, Ying; Qin, Song; Tao, Guo-Hong
2018-01-01
The instructive structure-property relationships of ionic liquids (ILs) can be put to task-specific design of new functionalized ILs. The dicyanamide (DCA) ILs are typical CHN type ILs which are halogen free, chemical stable, low-viscous, and fuel-rich. The transport properties of DCA ionic liquids are significant for their applications as solvents, electrolytes, and hypergolic propellants. This work systematically investigates several important transport properties of four DCA ILs ([C4mim][N(CN)2], [C4m2im][N(CN)2], N4442[N(CN)2], and N8444[N(CN)2]) including viscosity, conductivity, and electrochemical property at different temperatures. The melting points, temperature-dependent viscosities and conductivities reveal the structure-activity relationship of four DCA ILs. From the Walden plots, the imidazolium cations exhibit stronger cation–anion attraction than the ammonium cations. DCA ILs have relatively high values of electrochemical windows (EWs), which indicates that the DCA ILs are potential candidates for electrolytes in electrochemical applications. The cyclic voltammograms of Eu(III) in these DCA ILs at GC working electrode at various temperatures 303–333 K consists of quasi-reversible waves. The electrochemical properties of the DCA ILs are also dominated by the cationic structures. The current intensity (ip), the diffusion coefficients (Do), the charge transfer rate constants (ks) of Eu(III) in DCA ILs all increased with the molar conductivities increased. The cationic structure-transport property relationships of DCA ILs were constructed for designing novel functionalized ILs to fulfill specific demands. PMID:29600245
Zeng, Huawei; Claycombe, Kate J; Reindl, Katie M
2015-10-01
Consumption of a high-fat diet causes an increase in bile acid deoxycholic acid (DCA) in colon lumen and colon cancer risk, while butyrate, an intestinal microbiota metabolite of dietary fiber, has been shown to exhibit colon cancer-preventive effects. To distinguish these opposing effects of DCA and butyrate (two major metabolites in colon lumen), we examined the effects of physiologically relevant doses of butyrate (0.5-2 mmol/l) and DCA (0.05-0.3 mmol/l) on colon cell proliferation. We hypothesize that butyrate and DCA each modulates the cell cycle and apoptosis via common and distinct cellular signaling targets. In this study, we demonstrated that both butyrate and DCA inhibited cell proliferation by up to 89% and 92% and increased cell apoptosis rate by up to 3.1- and 4.5-fold, respectively. Cell cycle analyses revealed that butyrate led to an increase in G1 and G2 fractions with a concomitant drop in the S-phase fraction, but DCA induced an increase in only G1 fraction with a concomitant drop in the S-phase fraction when compared with the untreated cells. The examination of early cellular signaling revealed that DCA but not butyrate increased intracellular reactive oxygen species, genomic DNA breakage, the activation of ERK1/2, caspase-3 and PARP. In contrast, DCA decreased activated Rb protein level, and butyrate but not DCA increased p21 expression. Collectively, although both butyrate and DCA inhibit colonic cell proliferation, butyrate increases tumor suppressor gene expression, whereas DCA decreases tumor suppressor activation in cell cycle and apoptosis pathways. Published by Elsevier Inc.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schultz, Irv R.; Merdink, James L.; Gonzalez-Leon, Alberto
Dichloroacetate (DCA) is a well established rodent carcinogen commonly found in municipal drinking water supplies. Previous toxicokinetic studies have established that elimination of DCA is controlled by liver metabolism. DCA metabolism occurs by the cytosolic enzyme glutathione-S-transferase-zeta (GSTz). An important feature of the GSTz pathway is the autoinhibition of metabolism due to suicide inactivation of GSTz by DCA resulting in a direct reduction in GSTz activity. GSTz is identical to a key tyrosine catabolism enzyme known as maleylacetoacetate isomerase (MAAI; EC 5.3.1.2). In the tyrosine metabolism pathway, GSTz plays a critical role in catalyzing the isomerization of maleylacetoacetate to fumarylacetoacetate.more » Disruption of tyrosine catabolism has been linked to increased cancer risk in humans. We studied the elimination of i.v. doses of DCA to juvenile (8 week) and senescent (60 week) mice previously treated with DCA in their drinking water for 2 or 54 weeks. The diurnal change in blood concentrations of DCA was also monitored in mice exposed to three different drinking water concentrations of DCA (2.0, 0.5 and 0.05 g/L). Additional experiments measured the in-vitro metabolism of DCA in liver homogenates prepared from treated mice given various recovery times following treatment. The MAAI activity was also measured in liver cytosol obtained from treated mice. Results indicate juvenile mice were the most sensitive to changes in DCA elimination after drinking water treatment. MAAI activity was reduced up to 80% in liver cytosol from treated mice. These results indicate that inactivation and re-synthesis of GSTz is a highly dynamic process and is supportive of the hypothesis that decreased MAAI activity is a contributing factor in the carcinogenesis of DCA.« less
Wada, S; Kato, T; Mutai, M; Ozaki, K; Yamaguchi, S; Kim, D J; Baba-Toriyama, H; Asamoto, M; Ito, N; Tsuda, H
1996-03-01
Modifying effects of fibrosis or a cirrhotic state, caused by treatment with swine serum (SS), on the induction of preneoplastic focal lesions were assessed in a rat medium-term liver bioassay model for the detection of environmental carcinogens, in which the test compound is administered during the promotion phase after initiation with diethylnitrosamine. In experiment I, repeated intraperitoneal administration of SS concomitantly with the hepatopromoting agent deoxycholic acid (DCA) or phenobarbital (PB) resulted in a cirrhotic state and a significant increase in the number or size of preneoplastic glutathione S-transferase placental form (GST-P)-positive liver cell foci as compared to the corresponding DCA or PB alone groups. In experiment II, SS was given prior to commencement of the same medium-term bioassay system, in which a known hepatopromoting agent, DCA, 17-alpha-ethynylestradiol, or 2-acetylaminofluorene, was applied. In this case, the liver did not show obvious cirrhotic change and, rather than any enhancement, slight inhibition of promotion occurred. The results indicate that a coexisting, but not a pre-existing, cirrhotic condition acts to increase growth pressure on GST-P+ preneoplastic foci, and suggest that concomitant administration of SS with the promoting agent could be applied to improve the sensitivity of the assay protocol.
Bagante, Fabio; Spolverato, Gaya; Cucchetti, Alessandro; Gani, Faiz; Popescu, Irinel; Ruzzenente, Andrea; Marques, Hugo P; Aldrighetti, Luca; Gamblin, T Clark; Maithel, Shishir K; Sandroussi, Charbel; Bauer, Todd W; Shen, Feng; Poultsides, George A; Marsh, James Wallis; Guglielmi, Alfredo; Pawlik, Timothy M
2016-07-01
Regret-based decision curve analysis (DCA) is a framework that assesses the medical decision process according to physician attitudes (expected regret) relative to disease-based factors. We sought to apply this methodology to decisions around the operative management of intrahepatic cholangiocarcinoma (ICC). Utilizing a multicentric database of 799 patients who underwent liver resection for ICC, we developed a prognostic nomogram. DCA tested 3 strategies: (1) perform an operation on all patients, (2) never perform an operation, and (3) use the nomogram to select patients for an operation. Four preoperative variables were included in the nomogram: major vascular invasion (HR = 1.36), tumor number (multifocal, HR = 1.18), tumor size (>5 cm, HR = 1.45), and suspicious lymph nodes on imaging (HR = 1.47; all P < .05). The regret-DCA was assessed using an online survey of 50 physicians, expert in the treatment of ICC. For a patient with a multifocal ICC, largest lesion measuring >5 cm, one suspicious malignant lymph node, and vascular invasion on imaging, the 1-year predicted survival was 52% according to the nomogram. Based on the therapeutic decision of the regret-DCA, 60% of physicians would advise against an operation for this scenario. Conversely, all physicians recommended an operation to a patient with an early ICC (single nodule measuring 3 cm, no suspicious lymph nodes, and no vascular invasion at imaging). By integrating a nomogram based on preoperative variables and a regret-based DCA, we were able to define the elements of how decisions rely on medical knowledge (postoperative survival predicted by a nomogram, severity disease assessment) and physician attitudes (regret of commission and omission). Copyright © 2016 Elsevier Inc. All rights reserved.
Oxidative stress: a key regulator of leiomyoma cell survival.
Fletcher, Nicole M; Abusamaan, Mohammed S; Memaj, Ira; Saed, Mohammed G; Al-Hendy, Ayman; Diamond, Michael P; Saed, Ghassan M
2017-06-01
To determine the effects of attenuating oxidative stress with the use of dichloroacetate (DCA) on the expression of key redox enzymes myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) as well as on apoptosis. Prospective experimental study. University medical center. Cells established from myometrium and uterine fibroid from the same patients. Cells were exposed to normal (20% O 2 ) or hypoxic (2% O 2 ) conditions for 24 hours with or without DCA (20 μg/mL), a metabolic modulator that shifts anaerobic to aerobic metabolism. Nitrate/nitrite (iNOS activity indicator), iNOS, Bcl-2/Bax ratio, MPO, and caspase-3 activities and levels were determined by means of Greiss assay, real-time reverse-transcription polymerase chain reaction, and ELISA. Data were analyzed with the use of SPSS by means of one-way analysis of variance with Tukey post hoc analysis and independent t tests. MPO, iNOS, and nitrate/nitrite expression were higher in leiomyoma than in myometrial cells, and they were further enhanced by hypoxia in myometrial cells. Treatment with the use of DCA decreased MPO, iNOS, and nitrate/nitrite levels and negated the effect of hypoxia in both types of cells. Leiomyoma cells showed less apoptosis, as indicated by both caspase-3 activity and the Bcl-2/Bax ratio, than myometrial cells. Hypoxia further decreased apoptosis in myometrial cells with no further effect on leiomyoma cells. Treatment with DCA resulted in increased apoptosis in both types of cells, even in the presence of hypoxia. Shifting anaerobic to aerobic metabolism with the use of DCA resulted in an increase in apoptosis in leiomyoma cells and protected myometrial cells from the acquisition of the leiomyoma-like phenotype. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
Stimulation of 3,4-dichloroaniline mineralization by aniline.
You, I S; Bartha, R
1982-01-01
Mineralization of free and of humus-bound 3,4-dichloroaniline (DCA) by a Pseudomonas putida strain isolated by analog enrichment was greatly enhanced in the presence of aniline. The addition of aniline to soil that contained 0.2 to 100 micrograms of DCA per g in free or in humus-bound form increased the mineralization rates of DCA severalfold. Within the concentration ranges tested, absolute mineralization of DCA per unit time was positively correlated with both increasing DCA and increasing aniline concentrations. The specific enrichment of microbial populations and the induction of pathways that can co-metabolize DCA are the most plausible explanations for the effect of aniline. The observed phenomenon points to a potential approach for eliminating xenobiotic pollutants from contaminated soils. PMID:7138005
Abdel-Latif, Mohamed M; Inoue, Hiroyasu; Reynolds, John V
2016-09-01
Ursodeoxycholic acid (UDCA) was reported to reduce bile acid toxicity, but the mechanisms underlying its cytoprotective effects are not fully understood. The aim of the present study was to examine the effects of UDCA on the modulation of deoxycholic acid (DCA)-induced signal transduction in oesophageal cancer cells. Nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) activity was assessed using a gel shift assay. NF-κB activation and translocation was performed using an ELISA-based assay and immunofluorescence analysis. COX-2 expression was analysed by western blotting and COX-2 promoter activity was assessed by luciferase assay. DCA induced NF-κB and AP-1 DNA-binding activities in SKGT-4 and OE33 cells. UDCA pretreatment inhibited DCA-induced NF-κB and AP-1 activation and NF-κB translocation. This inhibitory effect was coupled with a blockade of IκB-α degradation and inhibition of phosphorylation of IKK-α/β and ERK1/2. Moreover, UDCA pretreatment inhibited COX-2 upregulation. Using transient transfection of the COX-2 promoter, UDCA pretreatment abrogated DCA-induced COX-2 promoter activation. In addition, UDCA protected oesophageal cells from the apoptotic effects of deoxycholate. Our findings indicate that UDCA inhibits DCA-induced signalling pathways in oesophageal cancer cells. These data indicate a possible mechanistic role for the chemopreventive actions of UDCA in oesophageal carcinogenesis.
Common modulation of limbic network activation underlies musical emotions as they unfold.
Singer, Neomi; Jacoby, Nori; Lin, Tamar; Raz, Gal; Shpigelman, Lavi; Gilam, Gadi; Granot, Roni Y; Hendler, Talma
2016-11-01
Music is a powerful means for communicating emotions among individuals. Here we reveal that this continuous stream of affective information is commonly represented in the brains of different listeners and that particular musical attributes mediate this link. We examined participants' brain responses to two naturalistic musical pieces using functional Magnetic Resonance imaging (fMRI). Following scanning, as participants listened to the musical pieces for a second time, they continuously indicated their emotional experience on scales of valence and arousal. These continuous reports were used along with a detailed annotation of the musical features, to predict a novel index of Dynamic Common Activation (DCA) derived from ten large-scale data-driven functional networks. We found an association between the unfolding music-induced emotionality and the DCA modulation within a vast network of limbic regions. The limbic-DCA modulation further corresponded with continuous changes in two temporal musical features: beat-strength and tempo. Remarkably, this "collective limbic sensitivity" to temporal features was found to mediate the link between limbic-DCA and the reported emotionality. An additional association with the emotional experience was found in a left fronto-parietal network, but only among a sub-group of participants with a high level of musical experience (>5years). These findings may indicate two processing-levels underlying the unfolding of common music emotionality; (1) a widely shared core-affective process that is confined to a limbic network and mediated by temporal regularities in music and (2) an experience based process that is rooted in a left fronto-parietal network that may involve functioning of the 'mirror-neuron system'. Copyright © 2016 Elsevier Inc. All rights reserved.
Merlino, Giuseppe; Marzorati, Massimo; Rizzi, Aurora; Lavazza, Davide; de Ferra, Francesca; Carpani, Giovanna
2015-01-01
The achievement of successful biostimulation of active microbiomes for the cleanup of a polluted site is strictly dependent on the knowledge of the key microorganisms equipped with the relevant catabolic genes responsible for the degradation process. In this work, we present the characterization of the bacterial community developed in anaerobic microcosms after biostimulation with the electron donor lactate of groundwater polluted with 1,2-dichloroethane (1,2-DCA). Through a multilevel analysis, we have assessed (i) the structural analysis of the bacterial community; (ii) the identification of putative dehalorespiring bacteria; (iii) the characterization of functional genes encoding for putative 1,2-DCA reductive dehalogenases (RDs). Following the biostimulation treatment, the structure of the bacterial community underwent a notable change of the main phylotypes, with the enrichment of representatives of the order Clostridiales. Through PCR targeting conserved regions within known RD genes, four novel variants of RDs previously associated with the reductive dechlorination of 1,2-DCA were identified in the metagenome of the Clostridiales-dominated bacterial community. PMID:26273600
Jenkins, G J S; Cronin, J; Alhamdani, A; Rawat, N; D'Souza, F; Thomas, T; Eltahir, Z; Griffiths, A P; Baxter, J N
2008-09-01
Deoxycholic acid (DCA) is a secondary bile acid implicated in various cancers of the gastrointestinal (GI) tract. In oesophageal adenocarcinoma, DCA is believed to contribute to carcinogenesis during reflux where stomach contents enter the lower oesophagus. It is imperative that we understand the mechanisms whereby oesophageal carcinogens function in order that therapeutic options may be developed. We have previously shown that DCA can damage chromosomes and does so through its generation of reactive oxygen species (ROS). We show here, after detailed experiments, that DCA appears to have a non-linear dose response for DNA damage. DCA induces DNA damage (as measured by the micronucleus assay) at doses of 100 microM and higher in oesophageal OE33 cells, but fails to induce such DNA damage below this cut-off dose. We also show that in terms of NF-kappaB activation (as measured by up-regulation of two NF-kappaB target genes) by DCA, a similar dose response is observed. This dose-response data may be important clinically as DCA exposure to the oesophagus may be used as a way to identify the 10% of Barrett's oesophagus patients currently progressing to cancer from the 90% of patients who do not progress. Only quantitative studies measuring DCA concentrations in refluxates correlated with histological progression will answer this question. We further show here that ROS are behind DCAs ability to activate NF-kappaB as antioxidants (epigallocatechin gallate, resveratrol and vitamin C) abrogate DCAs ability to up-regulate NF-kappaB-controlled genes. In conclusion, low doses of DCA appear to be less biologically significant in vitro. If this were to be confirmed in vivo, it might suggest that reflux patients with low DCA concentrations may be at a lower risk of cancer progression compared to patients with high levels of DCA in their refluxate. Either way, antioxidant supplementation may possibly help prevent the deleterious effects of DCA in the whole GI tract.
Okuzaki, Daisuke; Kuwana, Ritsuko; Takamatsu, Hiromu; Fujita, Masaya; Sarker, Mahfuzur R.; Miyake, Masami
2016-01-01
ABSTRACT Clostridium perfringens type A is a common source of foodborne illness (FBI) in humans. Vegetative cells sporulate in the small intestinal tract and produce the major pathogenic factor C. perfringens enterotoxin. Although sporulation plays a critical role in the pathogenesis of FBI, the mechanisms inducing sporulation remain unclear. Bile salts were shown previously to induce sporulation, and we confirmed deoxycholate (DCA)-induced sporulation in C. perfringens strain NCTC8239 cocultured with human intestinal epithelial Caco-2 cells. In the present study, we performed transcriptome analyses of strain NCTC8239 in order to elucidate the mechanism underlying DCA-induced sporulation. Of the 2,761 genes analyzed, 333 were up- or downregulated during DCA-induced sporulation and included genes for cell division, nutrient metabolism, signal transduction, and defense mechanisms. In contrast, the virulence-associated transcriptional regulators (the VirR/VirS system, the agr system, codY, and abrB) were not activated by DCA. DCA markedly increased the expression of signaling molecules controlled by Spo0A, the master regulator of the sporulation process, whereas the expression of spo0A itself was not altered in the presence or absence of DCA. The phosphorylation of Spo0A was enhanced in the presence of DCA. Collectively, these results demonstrated that DCA induced sporulation, at least partially, by facilitating the phosphorylation of Spo0A and activating Spo0A-regulated genes in strain NCTC8239 while altering the expression of various genes. IMPORTANCE Disease caused by Clostridium perfringens type A consistently ranks among the most common bacterial foodborne illnesses in humans in developed countries. The sporulation of C. perfringens in the small intestinal tract is a key event for its pathogenesis, but the factors and underlying mechanisms by which C. perfringens sporulates in vivo currently remain unclear. Bile salts, major components of bile, which is secreted from the liver for the emulsification of lipids, were shown to induce sporulation. However, the mechanisms underlying bile salt-induced sporulation have not yet been clarified. In the present study, we demonstrate that deoxycholate (one of the bile salts) induces sporulation by facilitating the phosphorylation of Spo0A and activating Spo0A-regulated genes using a transcriptome analysis. Thus, this study enhances our understanding of the mechanisms underlying sporulation, particularly that of bile salt-induced sporulation, in C. perfringens. PMID:26969700
Rial, Nathaniel S; Lazennec, Gwendal; Prasad, Anil R; Krouse, Robert S; Lance, Peter; Gerner, Eugene W
2009-01-01
Elevated deoxycholic acid (DCA), mutations in the adenomatous polyposis coli (APC) gene and chronic inflammation are associated with increased risk of colorectal cancer (CRC). APC status was manipulated to determine whether DCA mediates inflammatory molecules in normal or initiated colonic mucosa. DCA increased steady state mRNA and protein levels of CXCL8 in cells which do not express wild type APC. Steady state CXCL8 mRNA and protein were suppressed when cells with conditional expression of wild type APC were exposed to DCA. Immunostaining did not detect CXCL8 in normal human colonic mucosa. CXCL8 was expressed in adenomatous polyps and adenocarcinomas. CXCL8 expression correlated with nuclear β-catenin localization in epithelial cells of adenomas, but was associated with endothelial cells and neutrophils in the adenocarcinomas. DCA-mediated CXCL8 promoter-reporter activity was elevated in a mutant APC background. Wild type APC suppressed this effect. Mutation of activator protein-1 (AP-1) or nuclear factor kappa B (NF-κB) sites suppressed the activation of the CXCL8 promoter-reporter by DCA. Chromatin immunoprecipitation (ChIP) revealed that AP-1 and NF-κB binding to the 5′-promoter of CXCL8 was induced by DCA. The β-catenin transcription factor was bound to the 5′-promoter of CXCL8 in the absence or presence of DCA. Phenotypic assays determined that DCA-mediated invasion was blocked by antibody directed against CXCL8 or wild type-APC. CXCL8 exposure lead to matrix metalloproteinase-2 (MMP-2) production and increased invasion on laminin coated filters. These data suggest that DCA-mediated CXCL8 occurs in initiated colonic epithelium and neutralizing CXCL8 could reduce the invasive potential of tumors. PMID:19173296
Geomorphic determinants of species composition of alpine tundra, Glacier National Park, U.S.A.
George P. Malanson,; Bengtson, Lindsey E.; Fagre, Daniel B.
2012-01-01
Because the distribution of alpine tundra is associated with spatially limited cold climates, global warming may threaten its local extent or existence. This notion has been challenged, however, based on observations of the diversity of alpine tundra in small areas primarily due to topographic variation. The importance of diversity in temperature or moisture conditions caused by topographic variation is an open question, and we extend this to geomorphology more generally. The extent to which geomorphic variation per se, based on relatively easily assessed indicators, can account for the variation in alpine tundra community composition is analyzed versus the inclusion of broad indicators of regional climate variation. Visual assessments of topography are quantified and reduced using principal components analysis (PCA). Observations of species cover are reduced using detrended correspondence analysis (DCA). A “best subsets” regression approach using the Akaike Information Criterion for selection of variables is compared to a simple stepwise regression with DCA scores as the dependent variable and scores on significant PCA axes plus more direct measures of topography as independent variables. Models with geographic coordinates (representing regional climate gradients) excluded explain almost as much variation in community composition as models with them included, although they are important contributors to the latter. The geomorphic variables in the model are those associated with local moisture differences such as snowbeds. The potential local variability of alpine tundra can be a buffer against climate change, but change in precipitation may be as important as change in temperature.
Franke, Steffi; Lihl, Christina; Renpenning, Julian; Elsner, Martin; Nijenhuis, Ivonne
2017-12-01
Chlorinated ethanes belong to the most common groundwater and soil contaminants. Of these, 1,2-dichloroethane (1,2-DCA) is a man-made, persistent and toxic contaminant, released due to improper waste treatment at versatile production sites. This study investigated the anaerobic transformation of 1,2-DCA by Dehalococcoides mccartyi strain 195 and strain BTF08 using triple-element compound-specific stable isotope analysis of carbon, chlorine and hydrogen for the first time. Isotope fractionation patterns for carbon (εCBTF08 = -28.4 ± 3.7‰; εC195 = -30.9 ± 3.6‰) and chlorine (εClBTF08 = -4.6 ± 0.7‰; εCl195 = -4.2 ± 0.5‰) within both investigated D. mccartyi strains, as well as the dual-element analysis (ΛBTF08 = 6.9 ± 1.2; Λ195 = 7.1 ± 0.2), supported identical reaction mechanisms for dehalogenation of 1,2-DCA. Hydrogen isotope fractionation analysis revealed dihaloelimination as prevalent reaction mechanism. Vinyl chloride as major intermediate could be excluded by performing the experiment in deuterated aqueous media. Furthermore, evaluation of the derived apparent kinetic isotope effects (AKIECBTF08 = 1.029/AKIEC195 = 1.031; AKIEClBTF08 = 1.005/AKIECl195 = 1.004) pointed towards simultaneous abstraction of both involved chlorine-substituents in a concerted matter. It was shown that D. mccartyi strain BTF08 and strain 195 are capable of complete, direct dihaloelimination of 1,2-DCA to ethene. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
[Diagnosis and treatment guidelines for difficult-to-control asthma in children].
Navarro Merino, M; Andrés Martín, A; Asensio de la Cruz, O; García García, M L; Liñán Cortes, S; Villa Asensi, J R
2009-12-01
Children suffering from difficult-to-control asthma (DCA) require frequent appointments with their physician, complex treatment regimes and often admissions to hospital. Less than 5% of the asthmatic population suffer this condition. DCA must be correctly characterised to rule out false causes of DCA and requires making a differential diagnosis from pathologies that mimic asthma, comorbidity, environmental and psychological factors, and analysing the factors to determine poor treatment compliance. In true DCA cases, inflammation studies (exhaled nitric oxide, induced sputum, broncho-alveolar lavage and bronchial biopsy), pulmonary function and other clinical aspects can classify DCA into different phenotypes which could make therapeutic decision-making easier.
Both, Vanderlei; Thewes, Fabio Rodrigo; Brackmann, Auri; de Oliveira Anese, Rogerio; de Freitas Ferreira, Daniele; Wagner, Roger
2017-01-15
The effects of dynamic controlled atmosphere (DCA) storage based on chlorophyll fluorescence (DCA-CF) and respiratory quotient (DCA-RQ) on the quality and volatile profile of 'Royal Gala' apple were evaluated. DCA storage reduces ACC (1-aminocyclopropane-1-carboxylate) oxidase activity, ethylene production and respiration rate of apples stored for 9months at 1.0°C plus 7days at 20°C, resulting in higher flesh firmness, titratable acidity and lesser physiological disorders, and provided a higher proportion of healthy fruit. Storage in a regular controlled atmosphere gave higher levels of key volatiles (butyl acetate, 2-methylbutyl acetate and hexyl acetate), as compared to fruit stored under DCA-CF, but fruit stored under DCA-RQ 1.5 and RQ 2.0 also showed higher amounts of key volatile compounds, with increment in ethanol and ethyl acetate, but far below the odour threshold. Storage in DCA-CF reduces fruit ester production, especially 2-methylbutyl acetate, which is the most important component of 'Royal Gala' apple flavour. Copyright © 2016 Elsevier Ltd. All rights reserved.
Supercritical carbon dioxide treatment as a method for polymorph preparation of deoxycholic acid.
Tozuka, Yuichi; Kawada, Dai; Oguchi, Toshio; Yamamoto, Keiji
2003-09-16
A new polymorph of deoxycholic acid (DCA) was formed by using a supercritical carbon dioxide treatment. Deoxycholic acid crystals were stored in a pressure vessel purged with carbon dioxide at 12MPa, 60 degrees C for definite intervals. After storage for 1h in supercritical carbon dioxide (SC-CO2), new X-ray diffraction (XRD) peaks, not found in the bulk DCA crystal, were observed at 2theta = 7.4 degrees, 9.7 degrees and 14.0 degrees. The intensities of the new diffraction peaks increased with an increase in storage time, whereas the intensities of the diffraction peaks due to bulk DCA crystal decreased. On the DSC curves, the crystals obtained showed an exothermic peak at around 155 degrees C followed by the melting peak of bulk DCA crystal at 175 degrees C. By the temperature-controlled powder XRD measurement, the crystals obtained were found to be a metastable form of DCA. The polymorphs of DCA have not been reported; therefore, the SC-CO2 treatment would be a peculiar method to obtain a DCA polymorph.
El Arabi, H; Willems, D; Mélot, C; Dorchy, H
2013-01-01
Rapid in clinic measurement of glycated hemoglogin (HbA1c) allows to determine the level of metabolic control within a few minutes on capillary blood. We have evaluated the new DCA Vantage (Siemens) based on an immunological technique, replacing the DCA 2000+ (Siemens). The study included 120 unselected young type 1 diabetic patients, with different degrees of metabolic control. The DCA Vantage was compared with the HPLC system (Menarini HA 8160) whose deviation from the DCCT was < 0.1% across the clinical range. The mean underestimation of the DCA Vantage was -0.40%. The agreement limits (+/- 1.96 SD) were between 0.14% and -0.93%; this means +/- 0.53% around -0.40%. In conclusion, the DCA Vantage underestimates HbA1c levels; however it met the acceptance criteria of having a coefficient of variation < 3%.
Theoretical Investigation of the Reactivity of Sodium Dicyanamide with Nitric Acid.
Vogelhuber, Kristen M; Booth, Ryan S; Annesley, Christopher J
2018-03-01
There is a need to replace current hydrazine fuels with safer propellants, and dicyanamide (DCA - )-based systems have emerged as promising alternatives because they autoignite when mixed with some oxidizers. Previous studies of the hypergolic reaction mechanism have focused on the reaction between DCA - and the oxidizer HNO 3 ; here, we compare the calculated pathway of DCA - + HNO 3 with the reaction coordinate of the ion pair sodium dicyanamide with nitric acid, Na[DCA] + HNO 3 . Enthalpies and free energies are calculated in the gas phase and in solution using a quantum mechanical continuum solvation model, SMD-GIL. The barriers to the Na[DCA] + HNO 3 reaction are dramatically lowered relative to those of the reaction with the bare anion, and an exothermic exit channel to produce NaNO 3 and the reactive intermediate HDCA appears. These results suggest that Na[DCA] may accelerate the ignition reaction.
Bjerking, Louise Hougesen; Hansen, Kim Wadt; Madsen, Mette; Jensen, Jan Skov; Madsen, Jan Kyst; Sørensen, Rikke; Galatius, Søren
2016-06-01
Based on evident sex-related differences in the invasive management of patients presenting with acute myocardial infarction (AMI), we sought to identify predictors of diagnostic coronary angiography (DCA) and to investigate reasons for opting out an invasive strategy in women and men. The study was designed as a matched cohort study. We randomly selected 250 female cases from a source population of 4000 patients hospitalized with a first AMI in a geographically confined region of Denmark from January 2010 to November 2011. Each case was matched to a male control on age and availability of cardiac invasive facilities at the index hospital. We systematically reviewed medical records for risk factors, comorbid conditions, clinical presentation, and receipt of DCA. Clinical justifications, as stated by the treating physician, were noted for the subset of patients who did not receive a DCA. Overall, 187 women and 198 men received DCA within 60 days (75 % vs. 79 %, hazard ratio: 0.82 [0.67-1.00], p = 0.047).In the subset of patients who did not receive a DCA (n = 114), clinical justifications for opting out an invasive strategy was not documented for 21 patients (18.4 %). Type 2 myocardial infarction was noted in 11 patients (women versus men; 14.5 % vs. 3.8 %, p = 0.06) and identified as a potential confounder of the sex-DCA relationship. Receipt of DCA was predicted by traditional risk factors for ischaemic heart disease (family history of cardiovascular disease, hypercholesterolemia, and smoking) and clinical presentation (chest pain, ST-segment elevations). Although prevalent in both women and men, the presence of relative contraindications did not prohibit the use of DCA. In this matched cohort of patients with a first AMI, women and men had different clinical presentations despite similar age. However, no differences in the distribution of relative contraindications for DCA were found between the sexes. Type 2 MI posed a potentiel confounder for the sex-related differences in the use of DCA. Importantly,clinical justification for opting out an invasive strategy was not documented in almost one fifth of patients not receiving a DCA.
Evaluation of the combined solar TiO2/photo-Fenton process using multivariate analysis.
Nogueira, R F P; Trovó, A G; Paterlini, W C
2004-01-01
The effect of combining the photocatalytic processes using TiO2 and the photo-Fenton reaction with Fe3+ or ferrioxalate as a source of Fe2+ was investigated in the degradation of 4-chlorophenol (4CP) and dichloroacetic acid (DCA) using solar irradiation. Multivariate analysis was used to evaluate the role of three variables: iron, H2O2 and TiO2 concentrations. The results show that TiO2 plays a minor role when compared to iron and H2O2 in the solar degradation of 4CP and DCA in the studied conditions. However, its presence can improve TOC removal when H2O2 is totally consumed. Iron and peroxide play major roles, especially when Fe(NO3)3 is used in the degradation of 4CP. No significant synergistic effect was observed by the addition of TiO2 in this process. On the other hand, synergistic effects were observed between FeOx and TiO2 and between H2O2 and TiO2 in the degradation of DCA.
Hu, Liu-Dan; Yu, Bao-Ping; Yang, Bin
2012-10-01
The aim of this study was to investigate the effects of deoxycholic acid (DCA) on the contractions of rat proximal colonic smooth muscle (PCSM) in vitro. The contractile response of rat PCSM strips was tested using a polyphysio-graph. The whole cell patch-clamp technique was also used in rat colonic smooth muscle cells (SMCs) isolated by an enzymatic procedure to record the L-type calcium current (I(Ca-L)) prior to and following the application of various concentrations of DCA. The application of DCA (10(-6)-10(-4) M) decreased the amplitude of spontaneous contractions of the PCSM strips in a dose-dependent manner. The administration of DCA (10(-5) M) caused the relaxation of isolated smooth muscle strips pre-contracted by acetylcholine (Ach) or KCl (by 12.2±1.5 and 16.3±6.9%, respectively). The concentration-response curve of CaCl2 was shifted to the right. Pre-treatment of the strips with the protein kinase C (PKC) inhibitor chelerythrine (1 µM) significantly attenuated the effects of DCA on the strips pre-contracted by Ach. DCA reduced the peak I(Ca-L) by 6.02±0.87% at 10(-6) M, 15.02±1.73% at 10(-5) M and 47.14±3.79% at 10(-4) M. DCA shifted the current-voltage (I-V) curve of ICa-L upward, but the contour of the I-V curve was unchanged, and the peak current-induced voltage remained at 0 mV. Pre-treatment with chelerythrine (1 µM) blocked the actions of DCA on the I(Ca-L). Taken together, the actions of DCA on I(Ca-L) in rat colonic SMCs contributed to a negative inotropic effect. These actions appear to be mediated through protein kinase C. Furthermore, this study suggests another possible mechanism for the DCA-related modulation of gastrointestinal motility.
Melloni, Elisabetta; Gilli, Paola; Bertolasi, Valerio; Casciano, Fabio; Rigolin, Gian Matteo; Zauli, Giorgio; Secchiero, Paola
2016-01-01
Metformin and the mitochondrial targeting dichloroacetate (DCA) have recently received attention due to their ability to inhibit anaerobic glycolysis, which renders most cancer cells resistant to apoptosis induction. We observed that Metformin alone exhibited a dose-dependent anti-leukemic activity in both B leukemic cell lines and primary B-chronic lymphocytic leukemia (B-CLL) patients' cells and its anti-leukemic activity was enhanced when used in combination with DCA. In order to overcome the problems of poor bioavailability and cellular uptake, which limit DCA efficacy, we have designed and synthetized cocrystals consisting of Metformin and DCA (Met-DCA) at different stoichiometric ratios. Of note, the MetH2++•2DCA− cocrystal exhibited enhanced in vitro anti-leukemic activity, with respect to the treatment with the mix consisting of Metformin plus DCA. In particular, the treatment with the cocrystal MetH2++•2DCA− induced a synergistic apoptotic cell death coupled to a marked down-modulation of the anti-apoptotic Mcl-1 protein. Taken together, our data emphasize that innovative compounds based on Metformin-DCA combination merit to be further evaluated as chemotherapeutic agents for the treatment of B-CLL. PMID:26959881
ALTERED GENE EXPRESSION IN MOUSE LIVERS AFTER DICHLOROACETIC ACID EXPOSURE
Dichloroacetic acid (DCA) is a major by-product of water disinfection by chlorination. Several studies have demonstrated that DCA exhibits hepatocarcinogenic effects in rodents when administered in drinking water. The mechanism(s) involved in DCA induction of cancer are not clear...
Tumorigenic effects of dichloroacetic acid in female F344 rats
Introduction: Dichloroacetic acid (DCA) is a halogenated organic acid produced during oxidant disinfection of drinking water. Prior studies indicate that DCA may increase liver tumors in mice. Here we evaluated the hepatic tumorigenicity of DCA in female rats when given alone ...
Yasugi, Mayo; Okuzaki, Daisuke; Kuwana, Ritsuko; Takamatsu, Hiromu; Fujita, Masaya; Sarker, Mahfuzur R; Miyake, Masami
2016-05-15
Clostridium perfringens type A is a common source of foodborne illness (FBI) in humans. Vegetative cells sporulate in the small intestinal tract and produce the major pathogenic factor C. perfringens enterotoxin. Although sporulation plays a critical role in the pathogenesis of FBI, the mechanisms inducing sporulation remain unclear. Bile salts were shown previously to induce sporulation, and we confirmed deoxycholate (DCA)-induced sporulation in C. perfringens strain NCTC8239 cocultured with human intestinal epithelial Caco-2 cells. In the present study, we performed transcriptome analyses of strain NCTC8239 in order to elucidate the mechanism underlying DCA-induced sporulation. Of the 2,761 genes analyzed, 333 were up- or downregulated during DCA-induced sporulation and included genes for cell division, nutrient metabolism, signal transduction, and defense mechanisms. In contrast, the virulence-associated transcriptional regulators (the VirR/VirS system, the agr system, codY, and abrB) were not activated by DCA. DCA markedly increased the expression of signaling molecules controlled by Spo0A, the master regulator of the sporulation process, whereas the expression of spo0A itself was not altered in the presence or absence of DCA. The phosphorylation of Spo0A was enhanced in the presence of DCA. Collectively, these results demonstrated that DCA induced sporulation, at least partially, by facilitating the phosphorylation of Spo0A and activating Spo0A-regulated genes in strain NCTC8239 while altering the expression of various genes. Disease caused by Clostridium perfringens type A consistently ranks among the most common bacterial foodborne illnesses in humans in developed countries. The sporulation of C. perfringens in the small intestinal tract is a key event for its pathogenesis, but the factors and underlying mechanisms by which C. perfringens sporulates in vivo currently remain unclear. Bile salts, major components of bile, which is secreted from the liver for the emulsification of lipids, were shown to induce sporulation. However, the mechanisms underlying bile salt-induced sporulation have not yet been clarified. In the present study, we demonstrate that deoxycholate (one of the bile salts) induces sporulation by facilitating the phosphorylation of Spo0A and activating Spo0A-regulated genes using a transcriptome analysis. Thus, this study enhances our understanding of the mechanisms underlying sporulation, particularly that of bile salt-induced sporulation, in C. perfringens. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Interference of psychological factors in difficult-to-control asthma.
Halimi, Laurence; Vachier, Isabelle; Varrin, Muriel; Godard, Philippe; Pithon, Gérard; Chanez, Pascal
2007-01-01
Most patients with asthma can be controlled with suitable medication, but 5-10% of them remain difficult to control despite optimal management. We investigated whether patients with difficult-to-control asthma (DCA) or controlled asthma (CA) differ with respect to psychological factors, such as general control beliefs on life events. DCA was defined as an absence of control despite optimal management. Recent control was measured using the Asthma Control Questionnaire. General control beliefs were investigated using a Locus of Control scale (LOC). Patients with DCA had a significantly higher external LOC as compared to patients with CA (P=0.01). In the DCA group, the hospital admission rate was highly significant in association with the external LOC (P=0.004) as compared to the internal LOC trend. This study showed that patients with DCA had different general control beliefs which might have hampered their management and interfered with their therapeutic adherence. The present findings could enhance management of DCA in a clinical setting.
Dynamic controlled atmosphere and ultralow oxygen storage on 'Gala' mutants quality maintenance.
Thewes, Fabio Rodrigo; Both, Vanderlei; Brackmann, Auri; Weber, Anderson; de Oliveira Anese, Rogerio
2015-12-01
The aim of the present work was to compare the effect of ultralow oxygen (ULO) with dynamic controlled atmosphere (DCA) and controlled atmosphere (CA) on the post storage quality of 'Royal Gala' and 'Galaxy' apples after long-term storage. Two experiments were carried out with 'Royal Gala' and 'Galaxy' apples, in the years 2012 and 2013, respectively. A higher internal ethylene concentration was observed in fruits stored under CA; intermediate concentration in fruits under ULO; and the lowest by fruits stored under DCA-CF (DCA based on chlorophyll fluorescence). Flesh firmness was higher in fruits stored under DCA-CF and ULO differing from CA, in the year 2012, but in 2013 fruits stored under ULO showed the highest flesh firmness, differing from CA fruits. DCA-CF is efficient in quality maintenance of 'Royal Gala' and 'Galaxy' apples. Both 'Gala' mutants stored under ULO show a similar quality maintenance to those stored under DCA-CF. Copyright © 2015 Elsevier Ltd. All rights reserved.
Munro, Jacob E; Kimyon, Önder; Rich, Deborah J; Koenig, Joanna; Tang, Sihui; Low, Adrian; Lee, Matthew; Manefield, Mike; Coleman, Nicholas V
2017-11-01
1,2-Dichloroethane (DCA) is a problematic groundwater pollutant. Factors influencing the distribution and activities of DCA-degrading bacteria are not well understood, which has hampered their application for bioremediation. Here, we used quantitative PCR to investigate the distribution of putative DCA-dehalogenating bacteria at a DCA-impacted site in Sydney (Australia). The dehalogenase genes dhlA, tceA and bvcA were detected in all groundwater samples (n = 15), while vcrA was found in 11/15 samples. The 16S rRNA gene sequences specific to the dehalogenating genera Dehalobacter, Desulfitobacterium and Dehalogenimonas were detected in 15/15, 13/15 and 13/15 samples, respectively, while Dehalococcoides sequences were found in 9/15 samples. The tceA, bvcA and vcrA genes occurred in the same samples as Dehalococcoides and Dehalobacter. Microcosm experiments confirmed the presence of bacteria capable of dechlorination under anoxic conditions. The abundance of the dhlA gene, which is found in hydrolytic DCA degraders, was positively correlated to the DCA concentration, and was unexpectedly most abundant in samples with low oxygen conditions. A dhlA-containing bacterium isolated from the site (Xanthobacter EL8) was capable of anaerobic growth on DCA under denitrifying conditions. The presence of diverse DCA-dehalogenating bacteria at this site indicates that natural attenuation or biostimulation could be valid approaches for site cleanup. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Parallel structure among environmental gradients and three trophic levels in a subarctic estuary
Speckman, Suzann G.; Piatt, John F.; Minte-Vera, C. V.; Parrish, Julia K.
2005-01-01
We assessed spatial and temporal variability in the physical environment of a subarctic estuary, and examined concurrent patterns of chlorophyll α abundance (fluorescence), and zooplankton and forage fish community structure. Surveys were conducted in lower Cook Inlet, Alaska, during late July and early August from 1997 through 1999. Principle components analysis (PCA) revealed that spatial heterogeneity in the physical oceanographic environment of lower Cook Inlet could be modeled as three marine-estuarine gradients characterized by temperature, salinity, bottom depth, and turbidity. The gradients persisted from 1997 through 1999, and PCA explained 68% to 92% of the variance in physical oceanography for each gradient-year combination. Correlations between chlorophyll α abundance and distribution and the PCA axes were weak. Chlorophyll was reduced by turbidity, and low levels occurred in areas with high levels of suspended sediments. Detrended correspondence analysis (DCA) was used to order the sample sites based on species composition and to order the zooplankton and forage fish taxa based on similarities among sample sites for each gradient-year. Correlations between the structure of the physical environment (PCA axis 1) and zooplankton community structure (DCA axis 1) were strong (r = 0.43-0.86) in all years for the three marine-estuarine gradients, suggesting that zooplankton community composition was structured by the physical environment. The physical environment (PCA) and forage fish community structure (DCA) were weakly correlated in all years along Gradient 2, defined by halocline intensity and surface temperature and salinity, even though these physical variables were more important for defining zooplankton habitats. However, the physical environment (PCA) and forage fish community structure (DCA) were strongly correlated along the primary marine-estuarine gradient (#1) in 1997 (r = 0.87) and 1998 (r = 0.82). The correlation was poor (r = 0.32) in 1999, when fish community structure changed markedly in lower Cook Inlet. Capelin (Mallotus villosus), walleye pollock (Theragra chalcogramma), and arrowtooth flounder (Atheresthes stomias) were caught farther north than in previous years. Waters were significantly colder and more saline in 1999, a La Nina year, than in other years of the study. Interannual fluctuations in environmental conditions in lower Cook Inlet did not have substantial effects on zooplankton community structure, although abundance of individual taxa varied significantly. The abundance and distribution of chlorophyll α, zooplankton and forage fish were affected much more by spatial variability in physical oceanography than by interannual variability. Our examination of physical-biological linkages in lower Cook Inlet supports the concept of "bottom-up control," i.e., that variability in the physical environment structures higher trophic-level communities by influencing their distribution and abundance across space.
Parallel structure among environmental gradients and three trophic levels in a subarctic estuary
NASA Astrophysics Data System (ADS)
Speckman, Suzann G.; Piatt, John F.; Minte-Vera, Carolina V.; Parrish, Julia K.
2005-07-01
We assessed spatial and temporal variability in the physical environment of a subarctic estuary, and examined concurrent patterns of chlorophyll α abundance (fluorescence), and zooplankton and forage fish community structure. Surveys were conducted in lower Cook Inlet, Alaska, during late July and early August from 1997 through 1999. Principle components analysis (PCA) revealed that spatial heterogeneity in the physical oceanographic environment of lower Cook Inlet could be modeled as three marine-estuarine gradients characterized by temperature, salinity, bottom depth, and turbidity. The gradients persisted from 1997 through 1999, and PCA explained 68% to 92% of the variance in physical oceanography for each gradient-year combination. Correlations between chlorophyll α abundance and distribution and the PCA axes were weak. Chlorophyll was reduced by turbidity, and low levels occurred in areas with high levels of suspended sediments. Detrended correspondence analysis (DCA) was used to order the sample sites based on species composition and to order the zooplankton and forage fish taxa based on similarities among sample sites for each gradient-year. Correlations between the structure of the physical environment (PCA axis 1) and zooplankton community structure (DCA axis 1) were strong ( r = 0.43-0.86) in all years for the three marine-estuarine gradients, suggesting that zooplankton community composition was structured by the physical environment. The physical environment (PCA) and forage fish community structure (DCA) were weakly correlated in all years along Gradient 2, defined by halocline intensity and surface temperature and salinity, even though these physical variables were more important for defining zooplankton habitats. However, the physical environment (PCA) and forage fish community structure (DCA) were strongly correlated along the primary marine-estuarine gradient (#1) in 1997 ( r = 0.87) and 1998 ( r = 0.82). The correlation was poor ( r = 0.32) in 1999, when fish community structure changed markedly in lower Cook Inlet. Capelin ( Mallotus villosus), walleye pollock ( Theragra chalcogramma), and arrowtooth flounder ( Atheresthes stomias) were caught farther north than in previous years. Waters were significantly colder and more saline in 1999, a La Niña year, than in other years of the study. Interannual fluctuations in environmental conditions in lower Cook Inlet did not have substantial effects on zooplankton community structure, although abundance of individual taxa varied significantly. The abundance and distribution of chlorophyll α, zooplankton and forage fish were affected much more by spatial variability in physical oceanography than by interannual variability. Our examination of physical-biological linkages in lower Cook Inlet supports the concept of “bottom-up control,” i.e., that variability in the physical environment structures higher trophic-level communities by influencing their distribution and abundance across space.
Dichloroacetic acid (DCA) is a major by-product of water disinfection by chlorination. Several studies have demonstrated the hepatocarcinogenicity of DCA in mice when administered in drinking water. The mechanism of DCA carcinogenicity is not clear and we speculate that changes...
Chen, Zhongli; Schäffer, Andreas
2016-10-01
The anti-seasonal hydrology with 30m water fluctuations in the Three Gorges Reservoir (TGR) of China attracts growing environmental and ecological concerns. We investigated the biotransformation of the herbicide propanil in plants dominating in the littoral zone of the TGR by applying the 14 C-ring-labeled herbicide into non-aseptic hydroponic plant systems (Cynodon dactylon, Nelumbo nucifera and Bidens pilosa), aseptic plants (Lemna minor and Lemna gibba) and cell suspension cultures (C. dactylon and L. minor). (1) Propanil absorbed in plants of the hydroponic systems was (12.46±1.63)% of applied radioactivity (AR) (C. dactylon), (52.36±6.38)% (N. nucifera) and (76.55±6.07)% (B. pilosa), respectively. The 14 C-residues in the plant extractable fractions and the corresponding media were confirmed by radio-Thin Layer Chromatography (TLC), radio-High Performance Liquid Chromatography (HPLC) and Gas Chromatography-Electron Ionization Mass Spectrometry (GC-EIMS) as propanil, 3,4-dichloroaniline (DCA) and N-(3,4-dichlorophenyl)-β-d-glucopyranosylamine (Glu-DCA). (2) About 8% of AR was taken up by both aseptic plants, from which 7.0% of AR was extracted and identified also as propanil, DCA and Glu-DCA. (3) Concerning cell suspension cultures, (39.22±9.39)% of AR was absorbed by C. dactylon after 72hr, whereas the accumulated 14 C-propanil by L. minor cell suspension culture amounted to (65.04±1.72)% after 7days. The identified compounds in cell cultures are consistent with those in the tested plants. Most of the pesticide residues in the intact plants were un-extractable, which are recognized as the end of the detoxification process. We therefore consider these plants as suitable for the phytoremediation of the herbicide propanil in the TGR region. Copyright © 2016. Published by Elsevier B.V.
Vapor intrusion risk of lead scavengers 1,2-dibromoethane (EDB) and 1,2-dichloroethane (DCA).
Ma, Jie; Li, Haiyan; Spiese, Richard; Wilson, John; Yan, Guangxu; Guo, Shaohui
2016-06-01
Vapor intrusion of synthetic fuel additives represented a critical yet still neglected problem at sites impacted by petroleum fuel releases. This study used an advanced numerical model to simulate the vapor intrusion risk of lead scavengers 1,2-dibromoethane (ethylene dibromide, EDB) and 1,2-dichloroethane (DCA) under different site conditions. We found that simulated EDB and DCA indoor air concentrations can exceed USEPA screening level (4.7 × 10(-3) μg/m(3) for EDB and 1.1 × 10(-1) μg/m(3) for DCA) if the source concentration is high enough (is still within the concentration range found at leaking UST site). To evaluate the chance that vapor intrusion of EDB might exceed the USEPA screening levels for indoor air, the simulation results were compared to the distribution of EDB at leaking UST sites in the US. If there is no degradation of EDB or only abiotic degradation of EDB, from 15% to 37% of leaking UST sites might exceed the USEPA screening level. This study supports the statements made by USEPA in the Petroleum Vapor Intrusion (PVI) Guidance that the screening criteria for petroleum hydrocarbon may not provide sufficient protectiveness for fuel releases containing EDB and DCA. Based on a thorough literature review, we also compiled previous published data on the EDB and DCA groundwater source concentrations and their degradation rates. These data are valuable in evaluating EDB and DCA vapor intrusion risk. In addition, a set of refined attenuation factors based on site-specific information (e.g., soil types, source depths, and degradation rates) were provided for establishing site-specific screening criteria for EDB and DCA. Overall, this study points out that lead scavengers EDB and DCA may cause vapor intrusion problems. As more field data of EDB and DCA become available, we recommend that USEPA consider including these data in the existing PVI database and possibly revising the PVI Guidance as necessary. Copyright © 2016 Elsevier Ltd. All rights reserved.
Local delivery of cancer-cell glycolytic inhibitors in high-grade glioma
Wicks, Robert T.; Azadi, Javad; Mangraviti, Antonella; Zhang, Irma; Hwang, Lee; Joshi, Avadhut; Bow, Hansen; Hutt-Cabezas, Marianne; Martin, Kristin L.; Rudek, Michelle A.; Zhao, Ming; Brem, Henry; Tyler, Betty M.
2015-01-01
Background 3-bromopyruvate (3-BrPA) and dichloroacetate (DCA) are inhibitors of cancer-cell specific aerobic glycolysis. Their application in glioma is limited by 3-BrPA's inability to cross the blood-brain-barrier and DCA's dose-limiting toxicity. The safety and efficacy of intracranial delivery of these compounds were assessed. Methods Cytotoxicity of 3-BrPA and DCA were analyzed in U87, 9L, and F98 glioma cell lines. 3-BrPA and DCA were incorporated into biodegradable pCPP:SA wafers, and the maximally tolerated dose was determined in F344 rats. Efficacies of the intracranial 3-BrPA wafer and DCA wafer were assessed in a rodent allograft model of high-grade glioma, both as a monotherapy and in combination with temozolomide (TMZ) and radiation therapy (XRT). Results 3-BrPA and DCA were found to have similar IC50 values across the 3 glioma cell lines. 5% 3-BrPA wafer-treated animals had significantly increased survival compared with controls (P = .0027). The median survival of rats with the 50% DCA wafer increased significantly compared with both the oral DCA group (P = .050) and the controls (P = .02). Rats implanted on day 0 with a 5% 3-BrPA wafer in combination with TMZ had significantly increased survival over either therapy alone. No statistical difference in survival was noted when the wafers were added to the combination therapy of TMZ and XRT, but the 5% 3-BrPA wafer given on day 0 in combination with TMZ and XRT resulted in long-term survivorship of 30%. Conclusion Intracranial delivery of 3-BrPA and DCA polymer was safe and significantly increased survival in an animal model of glioma, a potential novel therapeutic approach. The combination of intracranial 3-BrPA and TMZ provided a synergistic effect. PMID:25053853
Zeng, Huawei; Botnen, James H; Briske-Anderson, Mary
2010-01-01
The cell growth inhibition induced by bile acid deoxycholic acid (DCA) may cause compensatory hyperproliferation of colonic epithelial cells and consequently increase colon cancer risk. On the other hand, there is increasing evidence for the efficacy of certain forms of selenium (Se) as anticancer nutrients. Methylselenol has been hypothesized to be a critical Se metabolite for anticancer activity in vivo. In this study, we demonstrated that both DCA (75-300 micromol/l) and submicromolar methylselenol inhibited colon cancer cell proliferation by up to 64% and 63%, respectively. In addition, DCA and methylselenol each increased colon cancer cell apoptosis rate by up to twofold. Cell cycle analyses revealed that DCA induced an increase in only the G1 fraction with a concomitant drop in G2 and S-phase; in contrast, methylselenol led to an increase in the G1 and G2 fractions with a concomitant drop only in the S-phase. Although both DCA and methylselenol significantly promoted apoptosis and inhibited cell growth, examination of mitogen-activated protein kinase (MAPK) pathway activation showed that DCA, but not methylselenol, induced SAPK/JNK1/2, p38 MAPK, ERK1/2 activation. Thus, our data provide, for the first time, the molecular basis for opposite effects of methylselenol and DCA on colon tumorigenesis.
Sakar, Ebru; Unver, Hulya; Ercisli, Sezai
2016-12-01
Olive (Olea europaea) is an ancient and important crop in both olive oil production and table use. It is important to identify the genetic diversity of olive genetic resources for cultivar development and evaluation of olive germplasm. In the study, 14 microsatellite markers (UDO4, UDO8, UDO9, UDO11, UDO12, UDO22, UDO24, UDO26, UDO28, DCA9, DCA11, DCA13, DCA15, and DCA18) were used to assess the genetic variation on 76 olive (Olea europaea L.) genotypes from Mardin province together with 6 well-known Turkish and 4 well-known foreign reference cultivars. All microsatellite markers showed polymorphism and the number of alleles varied between 9 and 22, with an average of 14.57. The most informative loci were DCA 11 (22 alleles) and DCA 9 (21 alleles). Dendrogram based on genetic distances was constructed for the 86 olive genotypes/cultivars, which revealed the existence of different clusters. The high genetic similarity was evident between Bakırkire2 and Zinnar5 (0.74) genotypes, while the most genetically divergent genotypes were Gürmeşe5 and Yedikardeşler2 (0.19). It was concluded that there was abundant SSR polymorphism in olive germplasm in southern Anatolia in Turkey and could be important for future breeding activities.
Palau, J; Yu, R; Hatijah Mortan, S; Shouakar-Stash, O; Rosell, M; Freedman, D L; Sbarbati, C; Fiorenza, S; Aravena, R; Marco-Urrea, E; Elsner, M; Soler, A; Hunkeler, D
2017-03-07
This study investigates, for the first time, dual C-Cl isotope fractionation during anaerobic biodegradation of 1,2-dichloroethane (1,2-DCA) via dihaloelimination by Dehalococcoides and Dehalogenimonas-containing enrichment cultures. Isotopic fractionation of 1,2-DCA (ε bulk C and ε bulk Cl ) for Dehalococcoides (-33.0 ± 0.4‰ and -5.1 ± 0.1‰) and Dehalogenimonas-containing microcosms (-23 ± 2‰ and -12.0 ± 0.8‰) resulted in distinctly different dual element C-Cl isotope correlations (Λ = Δδ 13 C/Δδ 37 Cl ≈ ε bulk C /ε bulk Cl ), 6.8 ± 0.2 and 1.89 ± 0.02, respectively. Determined isotope effects and detected products suggest that the difference on the obtained Λ values for biodihaloelimination could be associated with a different mode of concerted bond cleavage rather than two different reaction pathways (i.e., stepwise vs concerted). Λ values of 1,2-DCA were, for the first time, determined in two field sites under reducing conditions (2.1 ± 0.1 and 2.2 ± 2.9). They were similar to the one obtained for the Dehalogenimonas-containing microcosms (1.89 ± 0.02) and very different from those reported for aerobic degradation pathways in a previous laboratory study (7.6 ± 0.1 and 0.78 ± 0.03). Thus, this study illustrates the potential of a dual isotope analysis to differentiate between aerobic and anaerobic biodegradation pathways of 1,2-DCA in the field and suggests that this approach might also be used to characterize dihaloelimination of 1,2-DCA by different bacteria, which needs to be confirmed in future studies.
Zhang, Xiaoni; Wang, Qijian; Yang, Shaozong; Lin, Shengnan; Bao, Manzhu; Wu, Quanshu; Wang, Caiyun; Fu, Xiaopeng
2018-01-01
Dianthus is a large genus containing many species with high ornamental economic value. Extensive breeding strategies permitted an exploration of an improvement in the quality of cultivated carnation, particularly in flowers. However, little is known on the molecular mechanisms of flower development in carnation. Here, we report the identification and description of MADS-box genes in carnation (DcaMADS) with a focus on those involved in flower development and organ identity determination. In this study, 39 MADS-box genes were identified from the carnation genome and transcriptome by the phylogenetic analysis. These genes were categorized into four subgroups (30 MIKCc, two MIKC*, two Mα, and five Mγ). The MADS-box domain, gene structure, and conserved motif compositions of the carnation MADS genes were analysed. Meanwhile, the expression of DcaMADS genes were significantly different in stems, leaves, and flower buds. Further studies were carried out for exploring the expression of DcaMADS genes in individual flower organs, and some crucial DcaMADS genes correlated with their putative function were validated. Finally, a new expression pattern of DcaMADS genes in flower organs of carnation was provided: sepal (three class E genes and two class A genes), petal (two class B genes, two class E genes, and one SHORT VEGETATIVE PHASE (SVP)), stamen (two class B genes, two class E genes, and two class C), styles (two class E genes and two class C), and ovary (two class E genes, two class C, one AGAMOUS-LIKE 6 (AGL6), one SEEDSTICK (STK), one B sister, one SVP, and one Mα). This result proposes a model in floral organ identity of carnation and it may be helpful to further explore the molecular mechanism of flower organ identity in carnation. PMID:29617274
Zhang, Xiaoni; Wang, Qijian; Yang, Shaozong; Lin, Shengnan; Bao, Manzhu; Bendahmane, Mohammed; Wu, Quanshu; Wang, Caiyun; Fu, Xiaopeng
2018-04-04
Dianthus is a large genus containing many species with high ornamental economic value. Extensive breeding strategies permitted an exploration of an improvement in the quality of cultivated carnation, particularly in flowers. However, little is known on the molecular mechanisms of flower development in carnation. Here, we report the identification and description of MADS-box genes in carnation ( DcaMADS ) with a focus on those involved in flower development and organ identity determination. In this study, 39 MADS-box genes were identified from the carnation genome and transcriptome by the phylogenetic analysis. These genes were categorized into four subgroups (30 MIKC c , two MIKC*, two Mα, and five Mγ). The MADS-box domain, gene structure, and conserved motif compositions of the carnation MADS genes were analysed. Meanwhile, the expression of DcaMADS genes were significantly different in stems, leaves, and flower buds. Further studies were carried out for exploring the expression of DcaMADS genes in individual flower organs, and some crucial DcaMADS genes correlated with their putative function were validated. Finally, a new expression pattern of DcaMADS genes in flower organs of carnation was provided: sepal (three class E genes and two class A genes), petal (two class B genes, two class E genes, and one SHORT VEGETATIVE PHASE ( SVP )), stamen (two class B genes, two class E genes, and two class C), styles (two class E genes and two class C), and ovary (two class E genes, two class C, one AGAMOUS-LIKE 6 ( AGL6 ), one SEEDSTICK ( STK ), one B sister , one SVP , and one Mα ). This result proposes a model in floral organ identity of carnation and it may be helpful to further explore the molecular mechanism of flower organ identity in carnation.
Removal of EDB and 1,2-DCA by Abiotic Reaction with Iron(II) Sulfide
Ethylene Dibromide (EDB) and 1,2-Dichloroethane (1,2-DCA) were used as lead scavengers in leaded motor gasoline in the USA until the late 1980s. Leaded gasoline in contact with ground water should produce concentrations of EDB near 1900 µg/L, and concentrations of 1,2-DCA near 3...
NASA Astrophysics Data System (ADS)
Phenrat, T.; Le, T. S. T.
2017-12-01
1,2-Dichloroethane (1,2-DCA) is a prevalent subsurface contaminant found in groundwater and soil around the world. Nanoscale zero-valent iron (NZVI) is a promising in situ remediation agent for chlorinated organics. Nevertheless, 1,2-DCA is recalcitrant to reductive dechlorination using NZVI. Chemical oxidation using Fenton's reaction with conventional Fe2+ is a valid option for 1,2-DCA remediation with a major technical challenge, i.e. aquifer acidification is needed to maintain Fe2+ for catalytic reaction. In this work, NZVI Fenton's process at neutral pH was applied to degrade 1,2-DCA at high concentration (2,000 mg/L) representing dissolved 1,2-DCA concentration close to non-aqueous phase liquid source zone. Instead of using acidification to maintain dissolved Fe2+ concentration, NZVI Fenton's process is self-catalytic based on oxidative dissolution of NZVI in the present of H2O2. Interfacial H+ is produced at NZVI surface to provide appropriate local pH which continuously releases Fe2+ for Fenton's reaction. Approximately, 87% of 1,2-DCA was degraded at neutral pH with the pseudo first-order rate constant of 0.98 hour-1 using 10 g/L of NZVI and 200 mM of H2O2. However, the reaction was prohibited quickly within 3 hours presumably due to the rapid depletion of H2O2. The application of sequential H2O2 addition provided a better approach to prevent rapid inhibition via controlling the H2O2 concentration in the system to be sufficient but not excess, thus resulting in the higher degradation efficiency (the pseudo first-order rate constant of 0.49 hour-1 and 99 % degradation in 8 hours). Using NZVI with sequential H2O2 addition was also successful in degrading 1,2-DCA sorbed on to soil, yielding 99% removal of 1,2-DCA within 16 hours at the rate constant of 0.23 hour-1, around two times slower than in the system without soil presumably due to rate-limited 1,2-DCA desorption from soil. Mechanistic understanding of how sequential addition of H2O2, in comparison to the simultaneous H2O2 addition, can sustain oxidative degradation of 1,2-DCA was also proposed in addition to the investigation of NZVI reusability in three consecutive 1, 2-DCA degradation cycles.
Jensen; Price; Batten; Moubaraki; Murray
2000-09-01
The three-dimensional coordination polymers [Mn(dca)2(H2O)] (1) and [M(dca)(tcm)], M =Co (2), Ni (3), Cu (4), dca =dicyanamide, N(CN)2-, tcm = tricyanomethanide, C(CN)3-, have isomorphous structures. In 1 half the dca ligands coordinate directly (through all three nitrogen atoms) to three Mn atoms (all metal atoms are six-coordinate), while the other half coordinate to two Mn atoms (through the nitrile nitrogens) and hydrogen bond to water molecules coordinated to a third Mn atom (through the amide nitrogen). This dca. H2O structural moiety is disordered over a mirror plane, and is replaced by the structurally equivalent tcm ligand in compounds 2-4. The resulting structures display a new self-penetrating 3,6-connected (2:1) network topology that can be related to, but is different from, the rutile net. The self-penetrating [M(dca)(tcm)] network can be viewed as a structural compromise between the two interpenetrating rutile-like networks of [M(tcm)2] and the single rutile-like network of alpha-[M(dca)2]. The temperature and field dependence of the DC and AC magnetic susceptibilities and magnetisations has been measured for complexes 1-4. Compounds 1-3 exhibit long-range magnetic order with critical temperatures of 6.3 K for 1, 3.5 K for 2 and 8.0 K for 3. The Cu11 compound 4 does not order and is essentially a paramagnet. Hysteresis measurements of coercive field and remnant magnetisation show that 1, 2 and 3 are soft magnets, 1 being a canted-spin antiferromagnet (weak ferromagnet), while 2 and 3 are ferromagnets that display some unusual features in their high-field magnetisation isotherms in comparison to their related alpha-[M(dca)2] phases.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Draeger, E; Chen, H; Polf, J
Purpose: To test two new techniques, the distance-of-closest approach (DCA) and Compton line (CL) filters, developed as a means of improving the spatial resolution of Compton camera (CC) imaging. Methods: Gammas emitted from {sup 22}Na, {sup 137}Cs, and {sup 60}Co point sources were measured with a prototype 3-stage CC. The energy deposited and position of each interaction in each stage were recorded and used to calculate a “cone-of-origin” for each gamma that scattered twice in the CC. A DCA filter was developed which finds the shortest distance from the gamma’s cone-of-origin surface to the location of the gamma source. Themore » DCA filter was applied to the data to determine the initial energy of the gamma and to remove “bad” interactions that only contribute noise to the image. Additionally, a CL filter, which removes gamma events that do not follow the theoretical predictions of the Compton scatter equation, was used to further remove “bad” interactions from the measured data. Then images were reconstructed with raw, unfiltered data, DCA filtered data, and DCA+CL filtered data and the achievable image resolution of each dataset was compared. Results: Spatial resolutions of ∼2 mm, and better than 2 mm, were achievable with the DCA and DCA+CL filtered data, respectively, compared to > 5 mm for the raw, unfiltered data. Conclusion: In many special cases in medical imaging where information about the source position may be known, such as proton radiotherapy range verification, the application of the DCA and CL filters can result in considerable improvements in the achievable spatial resolutions of Compton imaging.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kong, Aiguo, E-mail: agkong@chem.ecnu.edu.cn; Fan, Xiaohong; Chen, Aoling
An in-situ MgO-templating synthesis route was introduced to obtain the mesoporous nitrogen-doped carbon microfibers by thermal conversion of new Mg-2,2′-biquinoline 4,4-dicarboxy acid coordination compound (Mg-DCA) microfibers. The investigated crystal structure of Mg-DCA testified that the assembling of Mg{sup 2+} and DCA through Mg-O coordination bond and hydrogen bond contributed to the formation of one-dimensional (1D) crystalline Mg-DCA microfibers. The nitrogen-doped carbons derived from the pyrolysis of Mg-DCA showed the well-defined microfiber morphology with high mesopore-surface area. Such mesoporous microfibers exhibited the efficient catalytic activity for oxygen reduction reaction (ORR) in alkaline solutions with better stability and methanol-tolerance performance. - Graphicalmore » abstract: Mesoporous nitrogen-doped carbon microfibers with efficient oxygen electroreduction activity were prepared by thermal conversion of new Mg-biquinoline-based coordination compound microfibers.« less
Dihydroconiferyl alcohol - A cell division factor from Acer species.
Lee, T S; Purse, J G; Pryce, R J; Horgan, R; Wareing, P F
1981-10-01
A compound that stimulated growth of soybean callus was isolated from spring sap of sycamore (Acer pseudoplatanus L.). Insufficient compound was isolated to permit it to be characterised. A compound with identical properties was isolated from commercial maple syrup, the concentrated spring sap of Acer saccharum L. The compound was identified as 3-(3-methoxy-4-hydroxyphenyl)-propan-1-ol (dihydroconiferyl alcohol, DCA). DCA was also active in the tobacco callus and radish leaf senescence assays, but was inactive in four other tests for cytokinin activity. DCA acted synergistically with kinetin to promote soybean callus growth. It is concluded that DCA has properties distinct from those of purine cytokinins.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, Sungkyoon; Kim, David; Pollack, Gary M.
2009-07-01
Trichloroethylene (TCE) is a well-known carcinogen in rodents and concerns exist regarding its potential carcinogenicity in humans. Oxidative metabolites of TCE, such as dichloroacetic acid (DCA) and trichloroacetic acid (TCA), are thought to be hepatotoxic and carcinogenic in mice. The reactive products of glutathione conjugation, such as S-(1,2-dichlorovinyl)-L-cysteine (DCVC), and S-(1,2-dichlorovinyl) glutathione (DCVG), are associated with renal toxicity in rats. Recently, we developed a new analytical method for simultaneous assessment of these TCE metabolites in small-volume biological samples. Since important gaps remain in our understanding of the pharmacokinetics of TCE and its metabolites, we studied a time-course of DCA, TCA,more » DCVG and DCVG formation and elimination after a single oral dose of 2100 mg/kg TCE in male B6C3F1 mice. Based on systemic concentration-time data, we constructed multi-compartment models to explore the kinetic properties of the formation and disposition of TCE metabolites, as well as the source of DCA formation. We conclude that TCE-oxide is the most likely source of DCA. According to the best-fit model, bioavailability of oral TCE was {approx} 74%, and the half-life and clearance of each metabolite in the mouse were as follows: DCA: 0.6 h, 0.081 ml/h; TCA: 12 h, 3.80 ml/h; DCVG: 1.4 h, 16.8 ml/h; DCVC: 1.2 h, 176 ml/h. In B6C3F1 mice, oxidative metabolites are formed in much greater quantities ({approx} 3600 fold difference) than glutathione-conjugative metabolites. In addition, DCA is produced to a very limited extent relative to TCA, while most of DCVG is converted into DCVC. These pharmacokinetic studies provide insight into the kinetic properties of four key biomarkers of TCE toxicity in the mouse, representing novel information that can be used in risk assessment.« less
Kim, Sungkyoon; Kim, David; Pollack, Gary M.; Collins, Leonard B.; Rusyn, Ivan
2009-01-01
Trichloroethylene (TCE) is a well-known carcinogen in rodents and concerns exist regarding its potential carcinogenicity in humans. Oxidative metabolites of TCE, such as dichloroacetic acid (DCA) and trichloroacetic acid (TCA), are thought to be hepatotoxic and carcinogenic in mice. The reactive products of glutathione conjugation, such as S-(1,2-dichlorovinyl)-L-cysteine (DCVC), and S-(1,2-dichlorovinyl) glutathione (DCVG), are associated with renal toxicity in rats. Recently, we developed a new analytical method for simultaneous assessment of these TCE metabolites in small-volume biological samples. Since important gaps remain in our understanding of the pharmacokinetics of TCE and its metabolites, we studied a time-course of DCA, TCA, DCVG and DCVG formation and elimination after a single oral dose of 2100 mg/kg TCE in male B6C3F1 mice. Based on systemic concentration-time data, we constructed multi-compartment models to explore the kinetic properties of the formation and disposition of TCE metabolites, as well as the source of DCA formation. We conclude that TCE-oxide is the most likely source of DCA. According to the best-fit model, bioavailability of oral TCE was ~74%, and the half-life and clearance of each metabolite in the mouse were as follows: DCA: 0.6 hr, 0.081 ml/hr; TCA: 12 hr, 3.80 ml/hr; DCVG: 1.4 hr, 16.8 ml/hr; DCVC: 1.2 hr, 176 ml/hr. In B6C3F1 mice, oxidative metabolites are formed in much greater quantities (~3600 fold difference) than glutathione-conjugative metabolites. In addition, DCA is produced to a very limited extent relative to TCA, while most of DCVG is converted into DCVC. These pharmacokinetic studies provide insight into the kinetic properties of four key biomarkers of TCE toxicity in the mouse, representing novel information that can be used in risk assessment. PMID:19409406
Tsalatsanis, Athanasios; Hozo, Iztok; Vickers, Andrew; Djulbegovic, Benjamin
2010-09-16
Decision curve analysis (DCA) has been proposed as an alternative method for evaluation of diagnostic tests, prediction models, and molecular markers. However, DCA is based on expected utility theory, which has been routinely violated by decision makers. Decision-making is governed by intuition (system 1), and analytical, deliberative process (system 2), thus, rational decision-making should reflect both formal principles of rationality and intuition about good decisions. We use the cognitive emotion of regret to serve as a link between systems 1 and 2 and to reformulate DCA. First, we analysed a classic decision tree describing three decision alternatives: treat, do not treat, and treat or no treat based on a predictive model. We then computed the expected regret for each of these alternatives as the difference between the utility of the action taken and the utility of the action that, in retrospect, should have been taken. For any pair of strategies, we measure the difference in net expected regret. Finally, we employ the concept of acceptable regret to identify the circumstances under which a potentially wrong strategy is tolerable to a decision-maker. We developed a novel dual visual analog scale to describe the relationship between regret associated with "omissions" (e.g. failure to treat) vs. "commissions" (e.g. treating unnecessary) and decision maker's preferences as expressed in terms of threshold probability. We then proved that the Net Expected Regret Difference, first presented in this paper, is equivalent to net benefits as described in the original DCA. Based on the concept of acceptable regret we identified the circumstances under which a decision maker tolerates a potentially wrong decision and expressed it in terms of probability of disease. We present a novel method for eliciting decision maker's preferences and an alternative derivation of DCA based on regret theory. Our approach may be intuitively more appealing to a decision-maker, particularly in those clinical situations when the best management option is the one associated with the least amount of regret (e.g. diagnosis and treatment of advanced cancer, etc).
2010-01-01
Background Decision curve analysis (DCA) has been proposed as an alternative method for evaluation of diagnostic tests, prediction models, and molecular markers. However, DCA is based on expected utility theory, which has been routinely violated by decision makers. Decision-making is governed by intuition (system 1), and analytical, deliberative process (system 2), thus, rational decision-making should reflect both formal principles of rationality and intuition about good decisions. We use the cognitive emotion of regret to serve as a link between systems 1 and 2 and to reformulate DCA. Methods First, we analysed a classic decision tree describing three decision alternatives: treat, do not treat, and treat or no treat based on a predictive model. We then computed the expected regret for each of these alternatives as the difference between the utility of the action taken and the utility of the action that, in retrospect, should have been taken. For any pair of strategies, we measure the difference in net expected regret. Finally, we employ the concept of acceptable regret to identify the circumstances under which a potentially wrong strategy is tolerable to a decision-maker. Results We developed a novel dual visual analog scale to describe the relationship between regret associated with "omissions" (e.g. failure to treat) vs. "commissions" (e.g. treating unnecessary) and decision maker's preferences as expressed in terms of threshold probability. We then proved that the Net Expected Regret Difference, first presented in this paper, is equivalent to net benefits as described in the original DCA. Based on the concept of acceptable regret we identified the circumstances under which a decision maker tolerates a potentially wrong decision and expressed it in terms of probability of disease. Conclusions We present a novel method for eliciting decision maker's preferences and an alternative derivation of DCA based on regret theory. Our approach may be intuitively more appealing to a decision-maker, particularly in those clinical situations when the best management option is the one associated with the least amount of regret (e.g. diagnosis and treatment of advanced cancer, etc). PMID:20846413
Zhao, Shengnan; Gong, Zizhen; Du, Xixi; Tian, Chunyan; Wang, Lingyu; Zhou, Jiefei; Xu, Congfeng; Chen, Yingwei; Cai, Wei; Wu, Jin
2018-01-01
We recently have proved that excessive fecal DCA caused by high-fat diet may serve as an endogenous danger-associated molecular pattern to activate NLRP3 inflammasome and thus contributes to the development of inflammatory bowel disease (IBD). Moreover, the effect of DCA on inflammasome activation is mainly mediated through bile acid receptor sphingosine-1-phosphate receptor 2 (S1PR2); however, the intermediate process remains unclear. Here, we sought to explore the detailed molecular mechanism involved and examine the effect of S1PR2 blockage in a colitis mouse model. In this study, we found that DCA could dose dependently upregulate S1PR2 expression. Meanwhile, DCA-induced NLRP3 inflammasome activation is at least partially achieved through stimulating extracellular regulated protein kinases (ERK) signaling pathway downstream of S1PR2 followed by promoting of lysosomal cathepsin B release. DCA enema significantly aggravated DSS-induced colitis in mice and S1PR2 inhibitor as well as inflammasome inhibition by cathepsin B antagonist substantially reducing the mature IL-1 β production and alleviated colonic inflammation superimposed by DCA. Therefore, our findings suggest that S1PR2/ERK1/2/cathepsin B signaling plays a critical role in triggering inflammasome activation by DCA and S1PR2 may represent a new potential therapeutic target for the management of intestinal inflammation in individuals on a high-fat diet.
Amphipathic dextran-doxorubicin prodrug micelles for solid tumor therapy.
Jin, Rong; Guo, Xuelian; Dong, Lingli; Xie, Enyuan; Cao, Aoneng
2017-10-01
A group of micelles self-assembled from deoxycholic acid-doxorubicin-conjugated dextran (denoted as Dex-DCA-DOX) prodrugs were designed and prepared for pH-triggered drug release and cancer chemotherapy. These prodrugs could be successfully produced by chemically coupling hydrophobic deoxycholic acid (DCA) to dextran hydrazine (denoted as Dex-NHNH 2 ) and hydrazone linker formation between doxorubicin (DOX) and Dex-NHNH 2 . These Dex-DCA-DOX prodrugs self-assembled to form micelles under physiological conditions with varied particle sizes depending on molecular weight of dextran, degree of substitution (DS) of DCA and DOX. After optimization, Dex10k-DCA9-DOX5.5 conjugate comprising dextran of 10kDa, DCA of DS 9 and DOX loading content of 5.5wt%, formed the micelles with the smallest size (110nm). These prodrug micelles could slowly liberate DOX under physiological conditions but efficiently released the drug at an acidified endosomal pH by the hydrolysis of acid-labile hydrazone linker. In vitro cytotoxicity experiment indicated that Dex10k-DCA9-DOX5.5 micelles exerted marked antitumor activity against MCF-7 and SKOV-3 cancer cells. Besides, intravenous administration of the micelles afforded growth inhibition of SKOV-3 tumor bearing in nude mice at a dosage of 2.5mg per kg with anti-cancer efficacy comparable to free DOX-chemotherapy but low systemic toxicity. This study highlights the feasibility of bio-safe and efficient dextran-based prodrug micelles designed for cancer chemotherapy. Copyright © 2017 Elsevier B.V. All rights reserved.
Boyd, Joseph S; Cheng, Ryan R; Paddock, Mark L; Sancar, Cigdem; Morcos, Faruck; Golden, Susan S
2016-09-15
Two-component systems (TCS) that employ histidine kinases (HK) and response regulators (RR) are critical mediators of cellular signaling in bacteria. In the model cyanobacterium Synechococcus elongatus PCC 7942, TCSs control global rhythms of transcription that reflect an integration of time information from the circadian clock with a variety of cellular and environmental inputs. The HK CikA and the SasA/RpaA TCS transduce time information from the circadian oscillator to modulate downstream cellular processes. Despite immense progress in understanding of the circadian clock itself, many of the connections between the clock and other cellular signaling systems have remained enigmatic. To narrow the search for additional TCS components that connect to the clock, we utilized direct-coupling analysis (DCA), a statistical analysis of covariant residues among related amino acid sequences, to infer coevolution of new and known clock TCS components. DCA revealed a high degree of interaction specificity between SasA and CikA with RpaA, as expected, but also with the phosphate-responsive response regulator SphR. Coevolutionary analysis also predicted strong specificity between RpaA and a previously undescribed kinase, HK0480 (herein CikB). A knockout of the gene for CikB (cikB) in a sasA cikA null background eliminated the RpaA phosphorylation and RpaA-controlled transcription that is otherwise present in that background and suppressed cell elongation, supporting the notion that CikB is an interactor with RpaA and the clock network. This study demonstrates the power of DCA to identify subnetworks and key interactions in signaling pathways and of combinatorial mutagenesis to explore the phenotypic consequences. Such a combined strategy is broadly applicable to other prokaryotic systems. Signaling networks are complex and extensive, comprising multiple integrated pathways that respond to cellular and environmental cues. A TCS interaction model, based on DCA, independently confirmed known interactions and revealed a core set of subnetworks within the larger HK-RR set. We validated high-scoring candidate proteins via combinatorial genetics, demonstrating that DCA can be utilized to reduce the search space of complex protein networks and to infer undiscovered specific interactions for signaling proteins in vivo Significantly, new interactions that link circadian response to cell division and fitness in a light/dark cycle were uncovered. The combined analysis also uncovered a more basic core clock, illustrating the synergy and applicability of a combined computational and genetic approach for investigating prokaryotic signaling networks. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Dietary calcium intake, serum copper concentration and bone density in postmenopausal women
DOE Office of Scientific and Technical Information (OSTI.GOV)
Strause, L.; Andon, M.B.; Howard, G.
1991-03-11
Data from experimental animal nutrition and animal husbandry indicate that several trace minerals, including copper (Cu) are involved in bone metabolism. In addition, a large body of data suggests that low dietary calcium (Ca) intake is a risk factor for age related bone loss. The authors measured the serum (Cu), dietary Ca intake (dCa) and bone mineral density (BMD) in the spine of 225 postmenopausal women. The median dCa and serum (Cu) were 562 mg/d and 9.73 umoles/L, respectively. Serum (Cu) but, not dCa, was greater in subjects with a history of estrogen therapy (ERT). BMD was higher in subjectsmore » with above median dCa and serum (Cu) (group 1) compared to those with below median values (group 2). BMD was intermediate for subjects with either Low serum (Cu):High dCa or High serum (Cu):Low dCa. This relationship was observed in the subject group as a whole, as well as in subgroups partitioned according to history of ERT. Groups 1 and 2 did not differ in basic demographic characteristics such as age, age at menopause, body weight and height. These data support the hypothesis that Ca and Cu nutriture are determinants of skeletal health in postmenopausal women.« less
Horemans, Benjamin; Breugelmans, Philip; Hofkens, Johan; Springael, Dirk
2017-03-01
Organic pollutant degrading biofilms in natural ecosystems and water treatment systems are often exposed to other carbon sources in addition to the pollutant. The availability of auxiliary carbon sources can lead to surplus biomass growth, changes in biofilm structure and carbon catabolite repression (CCR) which together will affect pollutant degradation rate and efficiency of the system. To understand the interplay between these processes, continuous biofilms of the 3,4-dichloroaniline (3,4-DCA) degrading Comamonas testosteroni WDL7-RFP were grown in single- and dual-substrate conditions with 3,4-DCA and/or citrate and reciprocal effects on 3,4-DCA/citrate degradation, biofilm biomass and biofilm structure were examined. The main mechanism affecting 3,4-DCA degradation in biofilms in dual-substrate conditions was citrate-mediated CCR as reflected by a decrease in specific 3,4-DCA degrading activity. Growth on citrate partially compensated for the lowered specific 3,4-DCA degradation activity under dual substrate conditions but not to the extent expected from growth observed under single-substrate conditions with citrate. This was explained by higher residual 3,4-DCA concentrations in the presence of citrate that increased cell dispersal in the biofilms. Our results show hampered pollutant removal in biofilms due to a complex interplay of auxiliary organic C source utilization for growth affecting the specific pollutant degradation rate and changes in cell physiology due to increased exposure to the pollutant as a result of lowered pollutant degradation rates. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jeong, K; Basavatia, A; Mynampati, D
Purpose: To compare VMAT SRS plans, dynamic conformal arc (DCA) plans, and Brainlab iPlan’s capability of planning and delivering brain SRS plans by employing HybridArc. HybridArc utilizes both DCA and IMRT. Using HybridArc, the amount of DCA versus IMRT needs to be optimized. Methods: Four SRS patients with the aim of reducing brainstem dose were selected for this study. All patients were contoured in iPlan and transferred to Eclipse for VMAT planning. In iPlan, DCA plans were created for each case. Moreover, nine HybridArc plans with DCA-IMRT ratios between 9:1 through 1:9 were created with a single ring structure generatedmore » by subtracting 3 mm expansion of target from a 10 mm expansion of the target. Two static IMRT beams were used in each of the five DCA arcs for HybridArc. The dose was prescribed to DCA only and HybridArc plans and normalized so that the target volume (TV) receives 100% dose to 99.5% of the TV to achieve 120% ∼ 130% max dose within targets. Following metrics were compared: PITV, V12Gy, CGIc, CGIg, CGI, brainstem max dose, and total monitor units (MUs). Results: A brainstem max dose comparable with VMAT from 30% IMRT and less with 50% or more IMRT could be achieved. PITV decreased with increasing IMRT portion and begins to saturate past an IMRT portion of 30%. The CGIg index, which represents how fast the dose falls off, was better with HybridArc in all HybridArc plans. Total MUs increased with increasing IMRT but less than VMAT in all cases. Conclusion: Overall, a lower brainstem max dose and a lower V12Gy with fewer MUs can be achieved with HybridArc. Considering all factors, it would be best to use a DCA-IMRT ratio of either 7:3 or 6:4.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Maurer, J; Sintay, B; Manning, M
Purpose: This study evaluates a novel algorithm that can be used with any treatment planning system for simple and rapid generation of stereotactic radiosurgery (SRS) plans for treating multiple brain metastases using a single isocenter dynamic conformal arc (DCA) approach. This technique is compared with a single isocenter volumetric modulated arc therapy (VMAT) technique in terms of delivery time, conformity, low dose spread and delivery accuracy. Methods: Five patients, with a total of 37 (5 – 11) targets were planned using a previously published method for generating optimal VMAT plans and using the proposed DCA algorithm. All planning target volumesmore » (PTVs) were planned to 20 Gy, meeting a minimum 99% coverage and maximum 135 % hot spot for both techniques. Quality assurance was performed using radiochromic film, with films placed in the high dose regions of each PTV. Normal tissue volumes receiving 12 Gy and 6 Gy (V12 and V6) were computed for each plan. Conformity index (CI) and gamma evaluations (95% of points passing 4%/0.5mm) were computed for each PTV. Results: Delivery times, including beam on and table rotation times, were comparable: 17 – 22 minutes for all deliveries. V12s for DCA plans were (18.5±15.2 cc) vs. VMAT (19.7±14.4 cc). V6s were significantly lower for DCA (69.0±52.0 cc) compared with VMAT (154.0±91.0 cc) (p <<0.05). CIs for VMAT targets were (1.38±0.50) vs. DCA (1.61±0.41). 36 of 37 DCA planned targets passed gamma tests, while 29 of 37 VMAT planned targets passed. Conclusion: Single isocenter DCA plans were easily achieved. The evaluation suggests that DCA may represent a favorable technique compared with VMAT for multiple target SRS by reducing dose to normal tissue and more accurately depicting deliverable dose.« less
Harper, Luke; Waubant, Alice; Vignes, Julien; Amat, Sara; Dobremez, Eric; Lefevre, Yan; Ferdynus, Cyril
2017-09-01
Prenatal management of male fetuses with suspected posterior urethral valves depends on reliable markers for postnatal long-term renal function. Whether ultrasound parameters, including the presence or absence of oligohydramnios, are reliable remains the subject of debate. We decided to evaluate the reliability of quantity of amniotic fluid to predict postnatal renal function using decision curve analysis (DCA), a method for evaluating the clinical utility of a diagnostic test. We analyzed retrospectively 51 male fetuses born with prenatally suspected posterior urethral valves between 2009 and 2012. We studied the relationship between quantity of amniotic fluid on prenatal ultrasound and the nadir creatinine during the first year of life as a proxy of postnatal renal function using DCA. Twelve fetuses presented with prenatal oligohydramnios. Thirty-one children had a normal nadir creatinine, of which one had prenatal oligohydramnios (3.2%). Thirteen had a nadir creatinine between 35 and 75 μmol/L, of which four had prenatal oligohydramnios (30.8%). Seven had a nadir creatinine >75 μmol/L, all of them had prenatal oligohydramnios. In this retrospective study, DCA confirms the relationship between prenatal quantity of amniotic fluid volume and postnatal renal function. © 2017 John Wiley & Sons, Ltd. © 2017 John Wiley & Sons, Ltd.
Evaluation of Food Freshness and Locality by Odor Sensor
NASA Astrophysics Data System (ADS)
Koike, Takayuki; Shimada, Koji; Kamimura, Hironobu; Kaneki, Noriaki
The aim of this study was to investigate whether food freshness and locality can be classified using a food evaluation system consisting four SnO2-semiconductor gas sensors and a solid phase column, into which collecting aroma materials. The temperature of sensors was periodically changed to be in unsteady state and thus, the sensor information was increased. The parameters (in quefrency band) were extracted from sensor information using cepstrum analysis that enable to separate superimposed information on sinusoidal wave. The quefrency was used as parameters for principal component and discriminant analyses (PCA and DCA) to detect food freshness and food localities. We used three kinds of strawberries, people can perceive its odors, passed from one to three days after harvest, and kelps and Ceylon tea, people are hardly to perceive its odor, corrected from five areas as sample. Then, the deterioration of strawberries and localities of kelps and Ceylon teas were visually evaluated using the numerical analyses. While the deteriorations were classified using PCA or DCA, the localities were classified only by DCA. The findings indicate that, although odorant intensity influenced the method detecting food quality, the quefrency obtained from odorant information using cepstrum analysis were available to detect the difference in the freshness and the localities of foods.
Lack of linear correlation between dynamic and steady-state cerebral autoregulation.
de Jong, Daan L K; Tarumi, Takashi; Liu, Jie; Zhang, Rong; Claassen, Jurgen A H R
2017-08-15
For correct application and interpretation of cerebral autoregulation (CA) measurements in research and in clinical care, it is essential to understand differences and similarities between dynamic and steady-state CA. The present study found no correlation between dynamic and steady-state CA indices in healthy older adults. There was variability between individuals in all (steady-state and dynamic) autoregulatory indices, ranging from low (almost absent) to highly efficient CA in this healthy population. These findings challenge the assumption that assessment of a single CA parameter or a single set of parameters can be generalized to overall CA functioning. Therefore, depending on specific research purposes, the choice for either steady-state or dynamic measures or both should be weighed carefully. The present study aimed to investigate the relationship between dynamic (dCA) and steady-state cerebral autoregulation (sCA). In 28 healthy older adults, sCA was quantified by a linear regression slope of proportionate (%) changes in cerebrovascular resistance (CVR) in response to proportionate (%) changes in mean blood pressure (BP) induced by stepwise sodium nitroprusside (SNP) and phenylephrine (PhE) infusion. Cerebral blood flow (CBF) was measured at the internal carotid artery (ICA) and vertebral artery (VA) and CBF velocity at the middle cerebral artery (MCA). With CVR = BP/CBF, Slope-CVR ICA , Slope-CVR VA and Slope-CVRi MCA were derived. dCA was assessed (i) in supine rest, analysed with transfer function analysis (gain and phase) and autoregulatory index (ARI) fit from spontaneous oscillations (ARI Baseline ), and (ii) with transient changes in BP using a bolus injection of SNP (ARI SNP ) and PhE (ARI PhE ). Comparison of sCA and dCA parameters (using Pearson's r for continuous and Spearman's ρ for ordinal parameters) demonstrated a lack of linear correlations between sCA and dCA measures. However, comparisons of parameters within dCA and within sCA were correlated. For sCA slope-CVR VA with Slope-CVRi MCA (r = 0.45, P < 0.03); for dCA ARI SNP with ARI PhE (ρ = 0.50, P = 0.03), ARI Baseline (ρ = 0.57, P = 0.03) and Phase LF (ρ = 0.48, P = 0.03); and for Gain VLF with Gain LF (r = 0.51, P = 0.01). By contrast to the commonly held assumption based on an earlier study, there were no linear correlations between sCA and dCA. As an additional observation, there was strong inter-individual variability, both in dCA and sCA, in this healthy group of elderly, in a range from low to high CA efficiency. © 2017 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.
Kinnaird, Adam; Dromparis, Peter; Saleme, Bruno; Gurtu, Vikram; Watson, Kristalee; Paulin, Roxane; Zervopoulos, Sotirios; Stenson, Trevor; Sutendra, Gopinath; Pink, Desmond B; Carmine-Simmen, Katia; Moore, Ronald; Lewis, John D; Michelakis, Evangelos D
2016-04-01
Clear-cell renal cell carcinoma (ccRCC) exhibits suppressed mitochondrial function and preferential use of glycolysis even in normoxia, promoting proliferation and suppressing apoptosis. ccRCC resistance to therapy is driven by constitutive hypoxia-inducible factor (HIF) expression due to genetic loss of von Hippel-Lindau factor. In addition to promoting angiogenesis, HIF suppresses mitochondrial function by inducing pyruvate dehydrogenase kinase (PDK), a gatekeeping enzyme for mitochondrial glucose oxidation. To reverse mitochondrial suppression of ccRCC using the PDK inhibitor dichloroacetate (DCA). Radical nephrectomy specimens from patients with ccRCC were assessed for PDK expression. The 786-O ccRCC line and two animal models (chicken in ovo and murine xenografts) were used for mechanistic studies. Mitochondrial function, proliferation, apoptosis, HIF transcriptional activity, angiogenesis, and tumor size were measured in vitro and in vivo. Independent-sample t-tests and analysis of variance were used for statistical analyses. PDK was elevated in 786-O cells and in ccRCC compared to normal kidney tissue from the same patient. DCA reactivated mitochondrial function (increased respiration, Krebs cycle metabolites such as α-ketoglutarate [cofactor of factor inhibiting HIF], and mitochondrial reactive oxygen species), increased p53 activity and apoptosis, and decreased proliferation in 786-O cells. DCA reduced HIF transcriptional activity in an FIH-dependent manner, inhibiting angiogenesis in vitro. DCA reduced tumor size and angiogenesis in vivo in both animal models. DCA can reverse the mitochondrial suppression of ccRCC and decrease HIF transcriptional activity, bypassing its constitutive expression. Its previous clinical use in humans makes it an attractive candidate for translation to ccRCC patients. We show that an energy-boosting drug decreases tumor growth and tumor blood vessels in animals carrying human kidney cancer cells. This generic drug has been used in patients for other conditions and thus could be tested in kidney cancer that remains incurable. Copyright © 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved.
Jensen, Dane D.; Godfrey, Cody B.; Niklas, Christian; Canals, Meritxell; Kocan, Martina; Poole, Daniel P.; Murphy, Jane E.; Alemi, Farzad; Cottrell, Graeme S.; Korbmacher, Christoph; Lambert, Nevin A.; Bunnett, Nigel W.; Corvera, Carlos U.
2013-01-01
TGR5 is a G protein-coupled receptor that mediates bile acid (BA) effects on energy balance, inflammation, digestion, and sensation. The mechanisms and spatiotemporal control of TGR5 signaling are poorly understood. We investigated TGR5 signaling and trafficking in transfected HEK293 cells and colonocytes (NCM460) that endogenously express TGR5. BAs (deoxycholic acid (DCA), taurolithocholic acid) and the selective agonists oleanolic acid and 3-(2-chlorophenyl)-N-(4-chlorophenyl)-N, 5-dimethylisoxazole-4-carboxamide stimulated cAMP formation but did not induce TGR5 endocytosis or recruitment of β-arrestins, as assessed by confocal microscopy. DCA, taurolithocholic acid, and oleanolic acid did not stimulate TGR5 association with β-arrestin 1/2 or G protein-coupled receptor kinase (GRK) 2/5/6, as determined by bioluminescence resonance energy transfer. 3-(2-chlorophenyl)-N-(4-chlorophenyl)-N, 5-dimethylisoxazole-4-carboxamide stimulated a low level of TGR5 interaction with β-arrestin 2 and GRK2. DCA induced cAMP formation at the plasma membrane and cytosol, as determined using exchange factor directly regulated by cAMP (Epac2)-based reporters, but cAMP signals did not desensitize. AG1478, an inhibitor of epidermal growth factor receptor tyrosine kinase, the metalloprotease inhibitor batimastat, and methyl-β-cyclodextrin and filipin, which block lipid raft formation, prevented DCA stimulation of ERK1/2. Bioluminescence resonance energy transfer analysis revealed TGR5 and EGFR interactions that were blocked by disruption of lipid rafts. DCA stimulated TGR5 redistribution to plasma membrane microdomains, as localized by immunogold electron microscopy. Thus, TGR5 does not interact with β-arrestins, desensitize, or traffic to endosomes. TGR5 signals from plasma membrane rafts that facilitate EGFR interaction and transactivation. An understanding of the spatiotemporal control of TGR5 signaling provides insights into the actions of BAs and therapeutic TGR5 agonists/antagonists. PMID:23818521
Li, Wenjun; Gu, Yuan; Hines, Ronald N.; Simpson, Pippa; Langaee, Taimour; Stacpoole, Peter W.
2012-01-01
Glutathione transferase ζ 1 (GSTZ1), also known as maleylacetoacetate isomerase, catalyzes the penultimate step of tyrosine catabolism and metabolizes several α-halocarboxylic acids, including dichloroacetic acid (DCA), an investigational drug used for lactic acidosis and, recently, solid tumors. Age-related differences have been suggested in DCA pharmacotoxicology, but no information is available on GSTZ1 ontogeny in humans. Here, we investigated the cytosolic GSTZ1 developmental expression pattern and the influence of haplotype on GSTZ1 activity with DCA by using human livers from donors between 10 weeks gestation and 74 years. GSTZ1 expression was very low in fetal livers (<2 pmol of GSTZ1/mg cytosol). The expression began to increase after birth in an age-dependent manner until age 7 years. GSTZ1 was then sustained at stable, yet variable, levels (median, 20.0 pmol/mg cytosol; range, 4.8–47.3 pmol/mg cytosol) until age 74 years. GSTZ1 activity with DCA was strongly associated with haplotype and expression level. Samples homozygous or heterozygous for GSTZ1A exhibited ∼3-fold higher DCA dechlorinating activity than samples carrying other alleles at a given level of expression. The correlations (r2) between activity and expression were 0.90 and 0.68, respectively, for GSTZ1A carriers (n = 11) and noncarriers (n = 61). GSTZ1 is expressed in mitochondria in addition to cytosol. The GSTZ1A allele exhibited similar effects in the mitochondrial fraction by conferring a higher activity with DCA. In summary, we report a neonatal onset and an age-related increase in GSTZ1 protein expression during human liver development. Haplotype influenced GSTZ1 activity with DCA but not protein expression. PMID:22028318
NASA Astrophysics Data System (ADS)
Falta, R. W.
2004-05-01
Ethylene dibromide (EDB) is a synthetic organic chemical that was produced in large amounts for use as a leaded gasoline additive and pesticide. The chlorinated solvent 1,2-dichlorethane (1,2-DCA) is widely used in the chemical industry, and was also added to leaded gasoline. EDB and 1,2-DCA are classified as probable human carcinogens by the United States Environmental Protection Agency (EPA), and EDB's use as a pesticide was suspended in 1984. The current EPA maximum contaminant level (MCL) for EDB in drinking water is 0.05 ug/l, and the MCL for 1,2-DCA is 5 ug/l. EDB has proven to be both mobile and persistent in groundwater, and contamination of groundwater by EDB was documented in several states beginning in the early 1980s. The majority of this contamination is attributed to agricultural uses of EDB, however approximately 90 percent of the EDB produced was used as a leaded gasoline additive, and it was present in virtually all leaded gasoline sold in the US. 1,2-DCA is commonly found as a groundwater contaminant, and it is both mobile and persistent. Past site investigations and remediation efforts at underground storage tank sites contaminated by leaded gasoline have rarely addressed the potential for EDB or 1,2-DCA contamination. However, the concentrations of EDB and 1,2-DCA in leaded gasoline were high enough to produce groundwater concentrations of thousands of ug/l. For this reason, there is a substantial likelihood that undetected EDB and 1,2-DCA plumes above the MCL may exist at many sites where leaded gasoline leaked or spilled. An initial review of field data from underground storage tank sites in two states suggests that this problem is widespread.
Peng, Sui; Huo, Xiaofang; Rezaei, Davood; Zhang, Qiuyang; Zhang, Xi; Yu, Chunhua; Asanuma, Kiyotaka; Cheng, Edaire; Pham, Thai H; Wang, David H; Chen, Minhu; Souza, Rhonda F; Spechler, Stuart Jon
2014-07-15
Hydrophobic bile acids like deoxycholic acid (DCA), which cause oxidative DNA damage and activate NF-κB in Barrett's metaplasia, might contribute to carcinogenesis in Barrett's esophagus. We have explored mechanisms whereby ursodeoxycholic acid (UDCA, a hydrophilic bile acid) protects against DCA-induced injury in vivo in patients and in vitro using nonneoplastic, telomerase-immortalized Barrett's cell lines. We took biopsies of Barrett's esophagus from 21 patients before and after esophageal perfusion with DCA (250 μM) at baseline and after 8 wk of oral UDCA treatment. DNA damage was assessed by phospho-H2AX expression, neutral CometAssay, and phospho-H2AX nuclear foci formation. Quantitative PCR was performed for antioxidants including catalase and GPX1. Nrf2, catalase, and GPX1 were knocked down with siRNAs. Reporter assays were performed using a plasmid construct containing antioxidant responsive element. In patients, baseline esophageal perfusion with DCA significantly increased phospho-H2AX and phospho-p65 in Barrett's metaplasia. Oral UDCA increased GPX1 and catalase levels in Barrett's metaplasia and prevented DCA perfusion from inducing DNA damage and NF-κB activation. In cells, DCA-induced DNA damage and NF-κB activation was prevented by 24-h pretreatment with UDCA, but not by mixing UDCA with DCA. UDCA activated Nrf2 signaling to increase GPX1 and catalase expression, and protective effects of UDCA pretreatment were blocked by siRNA knockdown of these antioxidants. UDCA increases expression of antioxidants that prevent toxic bile acids from causing DNA damage and NF-κB activation in Barrett's metaplasia. Elucidation of this molecular pathway for UDCA protection provides rationale for clinical trials on UDCA for chemoprevention in Barrett's esophagus. Copyright © 2014 the American Physiological Society.
Peng, Sui; Huo, Xiaofang; Rezaei, Davood; Zhang, Qiuyang; Zhang, Xi; Yu, Chunhua; Asanuma, Kiyotaka; Cheng, Edaire; Pham, Thai H.; Wang, David H.; Chen, Minhu; Spechler, Stuart Jon
2014-01-01
Hydrophobic bile acids like deoxycholic acid (DCA), which cause oxidative DNA damage and activate NF-κB in Barrett's metaplasia, might contribute to carcinogenesis in Barrett's esophagus. We have explored mechanisms whereby ursodeoxycholic acid (UDCA, a hydrophilic bile acid) protects against DCA-induced injury in vivo in patients and in vitro using nonneoplastic, telomerase-immortalized Barrett's cell lines. We took biopsies of Barrett's esophagus from 21 patients before and after esophageal perfusion with DCA (250 μM) at baseline and after 8 wk of oral UDCA treatment. DNA damage was assessed by phospho-H2AX expression, neutral CometAssay, and phospho-H2AX nuclear foci formation. Quantitative PCR was performed for antioxidants including catalase and GPX1. Nrf2, catalase, and GPX1 were knocked down with siRNAs. Reporter assays were performed using a plasmid construct containing antioxidant responsive element. In patients, baseline esophageal perfusion with DCA significantly increased phospho-H2AX and phospho-p65 in Barrett's metaplasia. Oral UDCA increased GPX1 and catalase levels in Barrett's metaplasia and prevented DCA perfusion from inducing DNA damage and NF-κB activation. In cells, DCA-induced DNA damage and NF-κB activation was prevented by 24-h pretreatment with UDCA, but not by mixing UDCA with DCA. UDCA activated Nrf2 signaling to increase GPX1 and catalase expression, and protective effects of UDCA pretreatment were blocked by siRNA knockdown of these antioxidants. UDCA increases expression of antioxidants that prevent toxic bile acids from causing DNA damage and NF-κB activation in Barrett's metaplasia. Elucidation of this molecular pathway for UDCA protection provides rationale for clinical trials on UDCA for chemoprevention in Barrett's esophagus. PMID:24852569
DOE Office of Scientific and Technical Information (OSTI.GOV)
Das, Laboni; Kumar, Rahul; Maity, Dilip K.
A pulse radiolysis study on pyrrolidinium cation based ionic liquids is presented here in this paper. Time-resolved absorption spectra for 1-methyl-1-propylpyrrolidinium dicyanamide (DCA) at 500 ns after the electron pulse show broad absorption bands at wavelengths below 440 nm and at 640 nm. In pyrrolidinium bis(trifluoromethylsulfonyl)imide (NTf 2) and tris(perfluoroethyl)trifluorophosphate (FAP) ILs, the transient absorption below 440 nm is much weaker. The absorption at 500 ns, which increases with wavelength from 500 nm to beyond 800 nm, was assigned to the tail of the solvated electron NIR absorption spectrum, since it disappears in the presence of N 2O. In themore » DCA IL, the presence of a reducing species was confirmed by the formation of pyrene radical anion. The difference in the transient species in the case of the DCA IL compared to other two ILs should be due to the anion, with cations being similar. In pseudohalide ILs such as DCA, radicals are formed by direct hole trapping by the anion (X – + h + → X•), followed by addition to the parent anion. Prediction of the UV/vis absorption spectra of the dimer radical anion by computational calculation supports the experimental results. The oxidizing efficiency of (DCA) 2•– and its reduction potential (E(DCA)2•–/(2DCA–)) have been determined.« less
Das, Laboni; Kumar, Rahul; Maity, Dilip K.; ...
2018-03-06
A pulse radiolysis study on pyrrolidinium cation based ionic liquids is presented here in this paper. Time-resolved absorption spectra for 1-methyl-1-propylpyrrolidinium dicyanamide (DCA) at 500 ns after the electron pulse show broad absorption bands at wavelengths below 440 nm and at 640 nm. In pyrrolidinium bis(trifluoromethylsulfonyl)imide (NTf 2) and tris(perfluoroethyl)trifluorophosphate (FAP) ILs, the transient absorption below 440 nm is much weaker. The absorption at 500 ns, which increases with wavelength from 500 nm to beyond 800 nm, was assigned to the tail of the solvated electron NIR absorption spectrum, since it disappears in the presence of N 2O. In themore » DCA IL, the presence of a reducing species was confirmed by the formation of pyrene radical anion. The difference in the transient species in the case of the DCA IL compared to other two ILs should be due to the anion, with cations being similar. In pseudohalide ILs such as DCA, radicals are formed by direct hole trapping by the anion (X – + h + → X•), followed by addition to the parent anion. Prediction of the UV/vis absorption spectra of the dimer radical anion by computational calculation supports the experimental results. The oxidizing efficiency of (DCA) 2•– and its reduction potential (E(DCA)2•–/(2DCA–)) have been determined.« less
Mechanistic study of the azithromycin dosage-form-dependent food effect.
Curatolo, William; Foulds, George; Labadie, Robert
2010-07-01
Azithromycin capsules are known to exhibit a negative food effect, manifest as a decrease in azithromycin bioavailability in the fed state. Azithromycin tablets are known to be bioequivalent to capsules in the fasted state, but do not exhibit a food effect. In the present study, the involvement of gastric degradation of azithromycin to des-cladinose azithromycin (DCA) has been investigated as a possible mechanism for the observed capsule food effect. Healthy volunteers were dosed with azithromycin tablets and capsules, fasted and fed, in a four-way randomized crossover study. Serum levels of DCA were measured as a function of time post-dose. Natural log-transformed PK parameters were statistically analyzed using an ANOVA model appropriate for the study design. When capsules were dosed to fed subjects, the systemic AUC for DCA was 243% of the value observed after fasted-state dosing, and the DCA C(max) was 270% of the value observed after fasted-state dosing. When azithromycin tablets were dosed in the fasted and fed states, there was no significant difference in systemic DCA. Gastric degradation of azithromycin to DCA is the likely mechanism for the observed negative food effect observed for azithromycin capsules. This effect is not observed for tablets. These observations suggest that azithromycin capsules exhibit slow and/or delayed disintegration in the fed stomach, resulting in extended gastric residence and degradation of a portion of the gastrically retained azithromycin.
Long-term Safety of Dichloroacetate in Congenital Lactic Acidosis
Abdelmalak, Monica; Lew, Alicia; Ramezani, Ryan; Shroads, Albert L.; Coats, Bonnie S.; Langaee, Taimour; Shankar, Meena N.; Neiberger, Richard E.; Subramony, S.H.; Stacpoole, Peter W.
2013-01-01
We followed 8 patients (4 males) with biochemically and/or molecular genetically proven deficiencies of the E1α subunit of the pyruvate dehydrogenase complex (PDC; 3 patients) or respiratory chain complexes I (1 patient), IV (3 patients) or I+IV (1 patient) who received oral dichloroacetate (DCA; 12.5 mg/kg/12 hours) for 9.7 to 16.5 years. All subjects originally participated in randomized controlled trials of DCA and were continued on an open-label chronic safety study. Patients (1 adult) ranged in age from 3.5 to 40.2 years at the start of DCA administration and are currently aged 16.9 to 49.9 years (mean ± SD: 23.5 ± 10.9 years). Subjects were either normal or below normal body weight for age and gender. The 3 PDC deficient patients did not consume high fat (ketogenic) diets. DCA maintained normal blood lactate concentrations, even in PDC deficient children on essentially unrestricted diets. Hematological, electrolyte, renal and hepatic status remained stable. Nerve conduction either did not change or decreased modestly and led to reduction or temporary discontinuation of DCA in 3 patients, although symptomatic worsening of peripheral neuropathy did not occur. We conclude that chronic DCA administration is generally well-tolerated in patients with congenital causes of lactic acidosis and is effective in maintaining normal blood lactate levels, even in PDC-deficient children not consuming strict ketogenic diets. PMID:23611579
Open release of the DCA++ project
NASA Astrophysics Data System (ADS)
Haehner, Urs; Solca, Raffaele; Staar, Peter; Alvarez, Gonzalo; Maier, Thomas; Summers, Michael; Schulthess, Thomas
We present the first open release of the DCA++ project, a highly scalable and efficient research code to solve quantum many-body problems with cutting edge quantum cluster algorithms. The implemented dynamical cluster approximation (DCA) and its DCA+ extension with a continuous self-energy capture nonlocal correlations in strongly correlated electron systems thereby allowing insight into high-Tc superconductivity. With the increasing heterogeneity of modern machines, DCA++ provides portable performance on conventional and emerging new architectures, such as hybrid CPU-GPU and Xeon Phi, sustaining multiple petaflops on ORNL's Titan and CSCS' Piz Daint. Moreover, we will describe how best practices in software engineering can be applied to make software development sustainable and scalable in a research group. Software testing and documentation not only prevent productivity collapse, but more importantly, they are necessary for correctness, credibility and reproducibility of scientific results. This research used resources of the Oak Ridge Leadership Computing Facility (OLCF) awarded by the INCITE program, and of the Swiss National Supercomputing Center. OLCF is a DOE Office of Science User Facility supported under Contract DE-AC05-00OR22725.
Subcarrier intensity modulation for MIMO visible light communications
NASA Astrophysics Data System (ADS)
Celik, Yasin; Akan, Aydin
2018-04-01
In this paper, subcarrier intensity modulation (SIM) is investigated for multiple-input multiple-output (MIMO) visible light communication (VLC) systems. A new modulation scheme called DC-aid SIM (DCA-SIM) is proposed for the spatial modulation (SM) transmission plan. Then, DCA-SIM is extended for multiple subcarrier case which is called DC-aid Multiple Subcarrier Modulation (DCA-MSM). Bit error rate (BER) performances of the considered system are analyzed for different MIMO schemes. The power efficiencies of DCA-SIM and DCA-MSM are shown in correlated MIMO VLC channels. The upper bound BER performances of the proposed models are obtained analytically for PSK and QAM modulation types in order to validate the simulation results. Additionally, the effect of power imbalance method on the performance of SIM is studied and remarkable power gains are obtained compared to the non-power imbalanced cases. In this work, Pulse amplitude modulation (PAM) and MSM-Index are used as benchmarks for single carrier and multiple carrier cases, respectively. And the results show that the proposed schemes outperform PAM and MSM-Index for considered single carrier and multiple carrier communication scenarios.
Wang, Dunling; Fiessel, Wanda
2008-01-01
This study evaluated three different dehydrated media for simultaneous detection and enumeration of total coliform (TC) and Escherichia coli in drinking water samples with a standard membrane filtration procedure. The experiment indicated that the differential coliform agar (DCA) medium was the most effective among the tested media in enumerating TC and E. coli, without the need for extensive accompanying confirmation tests. The results for DCA medium were highly reproducible for both TC and E. coli with standard deviation of 6.0 and 6.1, respectively. A high agreement (82%) was found between DCA and m-Endo media on 152 drinking water samples in terms of TC positive. The DCA medium also reduced concealment of background bacteria.
Allyn, Jérôme; Allou, Nicolas; Augustin, Pascal; Philip, Ivan; Martinet, Olivier; Belghiti, Myriem; Provenchere, Sophie; Montravers, Philippe; Ferdynus, Cyril
2017-01-01
The benefits of cardiac surgery are sometimes difficult to predict and the decision to operate on a given individual is complex. Machine Learning and Decision Curve Analysis (DCA) are recent methods developed to create and evaluate prediction models. We conducted a retrospective cohort study using a prospective collected database from December 2005 to December 2012, from a cardiac surgical center at University Hospital. The different models of prediction of mortality in-hospital after elective cardiac surgery, including EuroSCORE II, a logistic regression model and a machine learning model, were compared by ROC and DCA. Of the 6,520 patients having elective cardiac surgery with cardiopulmonary bypass, 6.3% died. Mean age was 63.4 years old (standard deviation 14.4), and mean EuroSCORE II was 3.7 (4.8) %. The area under ROC curve (IC95%) for the machine learning model (0.795 (0.755-0.834)) was significantly higher than EuroSCORE II or the logistic regression model (respectively, 0.737 (0.691-0.783) and 0.742 (0.698-0.785), p < 0.0001). Decision Curve Analysis showed that the machine learning model, in this monocentric study, has a greater benefit whatever the probability threshold. According to ROC and DCA, machine learning model is more accurate in predicting mortality after elective cardiac surgery than EuroSCORE II. These results confirm the use of machine learning methods in the field of medical prediction.
Fantini, Marco; Malinverni, Duccio; De Los Rios, Paolo; Pastore, Annalisa
2017-01-01
Direct coupling analysis (DCA) is a powerful statistical inference tool used to study protein evolution. It was introduced to predict protein folds and protein-protein interactions, and has also been applied to the prediction of entire interactomes. Here, we have used it to analyze three proteins of the iron-sulfur biogenesis machine, an essential metabolic pathway conserved in all organisms. We show that DCA can correctly reproduce structural features of the CyaY/frataxin family (a protein involved in the human disease Friedreich's ataxia) despite being based on the relatively small number of sequences allowed by its genomic distribution. This result gives us confidence in the method. Its application to the iron-sulfur cluster scaffold protein IscU, which has been suggested to function both as an ordered and a disordered form, allows us to distinguish evolutionary traces of the structured species, suggesting that, if present in the cell, the disordered form has not left evolutionary imprinting. We observe instead, for the first time, direct indications of how the protein can dimerize head-to-head and bind 4Fe4S clusters. Analysis of the alternative scaffold protein IscA provides strong support to a coordination of the cluster by a dimeric form rather than a tetramer, as previously suggested. Our analysis also suggests the presence in solution of a mixture of monomeric and dimeric species, and guides us to the prevalent one. Finally, we used DCA to analyze interactions between some of these proteins, and discuss the potentials and limitations of the method. PMID:28664160
Compartmental and Data-Based Modeling of Cerebral Hemodynamics: Linear Analysis.
Henley, B C; Shin, D C; Zhang, R; Marmarelis, V Z
Compartmental and data-based modeling of cerebral hemodynamics are alternative approaches that utilize distinct model forms and have been employed in the quantitative study of cerebral hemodynamics. This paper examines the relation between a compartmental equivalent-circuit and a data-based input-output model of dynamic cerebral autoregulation (DCA) and CO2-vasomotor reactivity (DVR). The compartmental model is constructed as an equivalent-circuit utilizing putative first principles and previously proposed hypothesis-based models. The linear input-output dynamics of this compartmental model are compared with data-based estimates of the DCA-DVR process. This comparative study indicates that there are some qualitative similarities between the two-input compartmental model and experimental results.
1994-02-01
awarded in 1984 to Martin Marietta Data System. A one-year extension to this contract has been approved, with the option of an additional year, if needed...remaining enhancements currently available with the Increment I software. B. Contracts: Martin Marietta , Information Systems Group is the systems...0016-Boeing Information Services Inc. DCA100-94-D-0017-Electronic Data Systems Corporation DCA100-94-D-0018- Martin Marietta Technical Svcs, Inc. DCA100
Ethanol-Induced Changes in Trichloroethylene Toxicity
1988-09-30
DCA or TCA. METHODS Chei .Ls. [l-14C]palmitoyl-CoA was purchased from New England Nuclear Products (Boston, MA); clofibrate , dichloroacetic acid (DCA...CLASSIFICATION OF _*NIS PAGE All other 04itions are obsolete. UCASFE UNLSSFE 0 . ( 1(A0~, AYOS-Th ච-1 173 .6. Aid (D,’Al and Trichlo’u,:eti: Acid ...published in 1231gj1gg 94 A221i2d EhabgnSggg 21:45-54 1088. Copy of manuscript "Dichloroacetic acid (DCA) and Trichloroacetic Acid (TCA) induced DNA
1980-05-22
cross -referenced with the number of the data transaction listed in the data module quality con- trol list NVB Integer variable used to...Organization of the Joint Chiefs of Staff. Technical support was provided by System Sciences, Incorporated under Contract Number DCA100-75-C-0019. Change set... Contract Number DCA 100-75-C-0019. Change set two was prepared u nder Contract Number DCA 100-78-C-0035. Computer Sciences Corporation prepared change
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhao, Bo; Yang, Yong, E-mail: yangy2@upmc.edu; Li, Xiang
In linac-based stereotactic radiosurgery (SRS) and radiotherapy (SRT), circular cone(s) or conformal arc(s) are conventionally used to treat intracranial lesions. However, when the target is in close proximity to critical structures, it is frequently quite challenging to generate a quality plan using these techniques. In this study, we investigated the dosimetric characteristics of using high–dose rate RapidArc (RA) technique for radiosurgical treatment of intracranial lesions. A total of 10 intracranial SRS/SRT cases previously planned using dynamic conformal arc (DCA) or cone-based techniques have been included in this study. For each case, 3 treatment plans were generated: (1) a DCA planmore » with multiple noncoplanar arcs, (2) a high–dose rate RA plan with arcs oriented the same as DCA (multiple-arc RA), and 3) a high–dose rate RA plan with a single coplanar arc (single-arc RA). All treatment plans were generated under the same prescription and similar critical structure dose limits. Plan quality for different plans was evaluated by comparing various dosimetric parameters such as target coverage, conformity index (CI), homogeneity index (HI), critical structures, and normal brain tissue doses as well as beam delivery time. With similar critical structure sparing, high–dose rate RA plans can achieve much better target coverage, dose conformity, and dose homogeneity than the DCA plans can. Plan quality indices CI and HI, for the DCA, multiple-arc RA, and single-arc RA techniques, were measured as 1.67 ± 0.39, 1.32 ± 0.28, and 1.38 ± 0.30 and 1.24 ± 0.11, 1.10 ± 0.04, and 1.12 ± 0.07, respectively. Normal brain tissue dose (V{sub 12} {sub Gy}) was found to be similar for DCA and multiple-arc RA plans but much larger for the single-arc RA plans. Beam delivery was similar for DCA and multiple-arc RA plans but shorter with single-arc RA plans. Multiple-arc RA SRS/SRT can provide better treatment plans than conventional DCA plans, especially for complex cases.« less
Qin, Gang; Bian, Zhao-Lian; Shen, Yi; Zhang, Lei; Zhu, Xiao-Hong; Liu, Yan-Mei; Shao, Jian-Guo
2016-06-04
Several models have been proposed to predict the short-term outcome of acute-on-chronic liver failure (ACLF) after treatment. We aimed to determine whether better decisions for artificial liver support system (ALSS) treatment could be made with a model than without, through decision curve analysis (DCA). The medical profiles of a cohort of 232 patients with hepatitis B virus (HBV)-associated ACLF were retrospectively analyzed to explore the role of plasma prothrombin activity (PTA), model for end-stage liver disease (MELD) and logistic regression model (LRM) in identifying patients who could benefit from ALSS. The accuracy and reliability of PTA, MELD and LRM were evaluated with previously reported cutoffs. DCA was performed to evaluate the clinical role of these models in predicting the treatment outcome. With the cut-off value of 0.2, LRM had sensitivity of 92.6 %, specificity of 42.3 % and an area under the receiving operating characteristic curve (AUC) of 0.68, which showed superior discrimination over PTA and MELD. DCA revealed that the LRM-guided ALSS treatment was superior over other strategies including "treating all" and MELD-guided therapy, for the midrange threshold probabilities of 16 to 64 %. The use of LRM-guided ALSS treatment could increase both the accuracy and efficiency of this procedure, allowing the avoidance of unnecessary ALSS.
Kinetics of heavy metal inhibition of 1,2-dichloroethane biodegradation in co-contaminated water.
Arjoon, Ashmita; Olaniran, Ademola Olufolahan; Pillay, Balakrishna
2015-03-01
Sites co-contaminated with heavy metals and 1,2-DCA may pose a greater challenge for bioremediation, as the heavy metals could inhibit the activities of microbes involved in biodegradation. Therefore, this study was undertaken to quantitatively assess the effects of heavy metals (arsenic, cadmium, mercury, and lead) on 1,2-DCA biodegradation in co-contaminated water. The minimum inhibitory concentrations (MICs) and concentrations of the heavy metals that caused half-life doubling (HLDs) of 1,2-DCA as well as the degradation rate coefficient (k(1)) and half-life (t(½)) of 1,2-DCA were measured and used to predict the toxicity of the heavy metals in the water microcosms. An increase in heavy metal concentration resulted in a progressive increase in the t(½) and relative t(½) and a decrease in k(1). The MICs and HLDs of the heavy metals were found to vary, depending on the heavy metals type. In addition, the presence of heavy metals was shown to inhibit 1,2-DCA biodegradation in a dose-dependent manner, with the following order of decreasing inhibitory effect: Hg(2+) > As(3+) > Cd(2+) > Pb(2+). Findings from this study have significant implications for the development of bioremediation strategies for effective degradation of 1,2-DCA and other related compounds in wastewater co-contaminated with heavy metals. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Bonner, Michael Y; Karlsson, Isabella; Rodolfo, Monica; Arnold, Rebecca S; Vergani, Elisabetta; Arbiser, Jack L
2016-03-15
The majority of human melanomas bears BRAF mutations and thus is treated with inhibitors of BRAF, such as vemurafenib. While patients with BRAF mutations often demonstrate an initial dramatic response to vemurafenib, relapse is extremely common. Thus, novel agents are needed for the treatment of these aggressive melanomas. Honokiol is a small molecule compound derived from Magnolia grandiflora that has activity against solid tumors and hematopoietic neoplasms. In order to increase the lipophilicity of honokiol, we have synthesized honokiol DCA, the dichloroacetate ester of honokiol. In addition, we synthesized a novel fluorinated honokiol analog, bis-trifluoromethyl-bis-(4-hydroxy-3-allylphenyl) methane (hexafluoro). Both compounds exhibited activity against A375 melanoma in vivo, but honokiol DCA was more active. Gene arrays comparing treated with vehicle control tumors demonstrated induction of the respiratory enzyme succinate dehydrogenase B (SDHB) by treatment, suggesting that our honokiol analogs induce respiration in vivo. We then examined its effect against a pair of melanomas, LM36 and LM36R, in which LM36R differs from LM36 in that LM36R has acquired vemurafenib resistance. Honokiol DCA demonstrated in vivo activity against LM36R (vemurafenib resistant) but not against parental LM36. Honokiol DCA and hexafluoro inhibited the phosphorylation of DRP1, thus stimulating a phenotype suggestive of respiration through mitochondrial normalization. Honokiol DCA may act in vemurafenib resistant melanomas to increase both respiration and reactive oxygen generation, leading to activity against aggressive melanoma in vivo.
Sequential Gaussian co-simulation of rate decline parameters of longwall gob gas ventholes.
Karacan, C Özgen; Olea, Ricardo A
2013-04-01
Gob gas ventholes (GGVs) are used to control methane inflows into a longwall mining operation by capturing the gas within the overlying fractured strata before it enters the work environment. Using geostatistical co-simulation techniques, this paper maps the parameters of their rate decline behaviors across the study area, a longwall mine in the Northern Appalachian basin. Geostatistical gas-in-place (GIP) simulations were performed, using data from 64 exploration boreholes, and GIP data were mapped within the fractured zone of the study area. In addition, methane flowrates monitored from 10 GGVs were analyzed using decline curve analyses (DCA) techniques to determine parameters of decline rates. Surface elevation showed the most influence on methane production from GGVs and thus was used to investigate its relation with DCA parameters using correlation techniques on normal-scored data. Geostatistical analysis was pursued using sequential Gaussian co-simulation with surface elevation as the secondary variable and with DCA parameters as the primary variables. The primary DCA variables were effective percentage decline rate, rate at production start, rate at the beginning of forecast period, and production end duration. Co-simulation results were presented to visualize decline parameters at an area-wide scale. Wells located at lower elevations, i.e., at the bottom of valleys, tend to perform better in terms of their rate declines compared to those at higher elevations. These results were used to calculate drainage radii of GGVs using GIP realizations. The calculated drainage radii are close to ones predicted by pressure transient tests.
Sequential Gaussian co-simulation of rate decline parameters of longwall gob gas ventholes
Karacan, C. Özgen; Olea, Ricardo A.
2013-01-01
Gob gas ventholes (GGVs) are used to control methane inflows into a longwall mining operation by capturing the gas within the overlying fractured strata before it enters the work environment. Using geostatistical co-simulation techniques, this paper maps the parameters of their rate decline behaviors across the study area, a longwall mine in the Northern Appalachian basin. Geostatistical gas-in-place (GIP) simulations were performed, using data from 64 exploration boreholes, and GIP data were mapped within the fractured zone of the study area. In addition, methane flowrates monitored from 10 GGVs were analyzed using decline curve analyses (DCA) techniques to determine parameters of decline rates. Surface elevation showed the most influence on methane production from GGVs and thus was used to investigate its relation with DCA parameters using correlation techniques on normal-scored data. Geostatistical analysis was pursued using sequential Gaussian co-simulation with surface elevation as the secondary variable and with DCA parameters as the primary variables. The primary DCA variables were effective percentage decline rate, rate at production start, rate at the beginning of forecast period, and production end duration. Co-simulation results were presented to visualize decline parameters at an area-wide scale. Wells located at lower elevations, i.e., at the bottom of valleys, tend to perform better in terms of their rate declines compared to those at higher elevations. These results were used to calculate drainage radii of GGVs using GIP realizations. The calculated drainage radii are close to ones predicted by pressure transient tests.
Sequential Gaussian co-simulation of rate decline parameters of longwall gob gas ventholes
Karacan, C.Özgen; Olea, Ricardo A.
2015-01-01
Gob gas ventholes (GGVs) are used to control methane inflows into a longwall mining operation by capturing the gas within the overlying fractured strata before it enters the work environment. Using geostatistical co-simulation techniques, this paper maps the parameters of their rate decline behaviors across the study area, a longwall mine in the Northern Appalachian basin. Geostatistical gas-in-place (GIP) simulations were performed, using data from 64 exploration boreholes, and GIP data were mapped within the fractured zone of the study area. In addition, methane flowrates monitored from 10 GGVs were analyzed using decline curve analyses (DCA) techniques to determine parameters of decline rates. Surface elevation showed the most influence on methane production from GGVs and thus was used to investigate its relation with DCA parameters using correlation techniques on normal-scored data. Geostatistical analysis was pursued using sequential Gaussian co-simulation with surface elevation as the secondary variable and with DCA parameters as the primary variables. The primary DCA variables were effective percentage decline rate, rate at production start, rate at the beginning of forecast period, and production end duration. Co-simulation results were presented to visualize decline parameters at an area-wide scale. Wells located at lower elevations, i.e., at the bottom of valleys, tend to perform better in terms of their rate declines compared to those at higher elevations. These results were used to calculate drainage radii of GGVs using GIP realizations. The calculated drainage radii are close to ones predicted by pressure transient tests. PMID:26190930
Harper, Luke; Delforge, Xavier; Maurin, Sophie; Leroy, Valerie; Michel, Jean-Luc; Sauvat, Frederique; Ferdynus, Cyril
2016-10-01
The benefit of post-urinary tract infection (UTI) sonography to detect clinically significant renal abnormalities remains a subject open to debate. Decision curve analysis (DCA) is a novel method for evaluating the clinical usefulness of diagnostic tests. Our objective was to determine, using DCA, the benefit of post-UTI sonography and of post-UTI sonography with biological markers of inflammation to predict the risk of recurrence of febrile UTI in children aged 2 to 24 months without known uropathy. We retrospectively analyzed all children aged 2 to 24 months, without known uropathy, who presented with a first episode of febrile UTI between 2009 and 2012 and followed them for 30 months. We then used DCA to estimate the benefit of post-UTI sonography or post-UTI sonography + biological markers of inflammation for detecting the risk of recurrence. A total of 318 children [144 boys (45.3 %) and 174 girls (54.7 %)], with a mean age of 6.9 ± 5.6 months, were identified. Of these, 210 children presented with a significant inflammation [66.2 %; 95 % confidence interval (CI) 61.0-71.4], and 30 (9.4 %; 95 % CI 6.2-12.6) presented with abnormal post-UTI sonographic findings. Eighteen (5.7 %; 95 % CI 3.1-8.2) children presented with recurrent UTI at 30 months. There were significantly more recurrences in those children who presented with abnormal sonographic findings than in those who did not (relative risk 7.68; 95 % CI 3.03-19.46). However, taking into account the effect of false-positives and false negatives, the DCA revealed that for threshold probabilities of >30 %, at which patients/doctors are concerned about unnecessary interventions (whether tests or treatments), neither post-UTI sonography nor post-UTI sonography + biological markers of inflammation have sufficient value to improve care.
NASA Astrophysics Data System (ADS)
Kim, Hyo-Su; Kim, Dong-Hoi
The dynamic channel allocation (DCA) scheme in multi-cell systems causes serious inter-cell interference (ICI) problem to some existing calls when channels for new calls are allocated. Such a problem can be addressed by advanced centralized DCA design that is able to minimize ICI. Thus, in this paper, a centralized DCA is developed for the downlink of multi-cell orthogonal frequency division multiple access (OFDMA) systems with full spectral reuse. However, in practice, as the search space of channel assignment for centralized DCA scheme in multi-cell systems grows exponentially with the increase of the number of required calls, channels, and cells, it becomes an NP-hard problem and is currently too complicated to find an optimum channel allocation. In this paper, we propose an ant colony optimization (ACO) based DCA scheme using a low-complexity ACO algorithm which is a kind of heuristic algorithm in order to solve the aforementioned problem. Simulation results demonstrate significant performance improvements compared to the existing schemes in terms of the grade of service (GoS) performance and the forced termination probability of existing calls without degrading the system performance of the average throughput.
Dichloroacetate treatment in Leigh syndrome caused by mitochondrial DNA mutation.
Takanashi, J; Sugita, K; Tanabe, Y; Maemoto, T; Niimi, H
1997-01-01
Sodium dichloroacetate (DCA) was administered to a 1-year-old female case of Leigh syndrome, who had a T > G point mutation at nt 8993 of mitochondrial DNA. Her biochemical and clinical symptoms improved gradually, but proton magnetic resonance spectroscopy revealed reduction of the N-acetylaspartate/creatine ratio, and magnetic resonance imaging showed progressive cerebral atrophy despite the DCA therapy. These results suggest that DCA therapy may not retard the progress of the primary disease in Leigh syndrome, but produced clinical improvement most likely by reducing toxic accumulation of lactate.
Physiologically Based Pharmacokinetic (PBPK) Modeling of ...
Background: Quantitative estimation of toxicokinetic variability in the human population is a persistent challenge in risk assessment of environmental chemicals. Traditionally, inter-individual differences in the population are accounted for by default assumptions or, in rare cases, are based on human toxicokinetic data.Objectives: To evaluate the utility of genetically diverse mouse strains for estimating toxicokinetic population variability for risk assessment, using trichloroethylene (TCE) metabolism as a case study. Methods: We used data on oxidative and glutathione conjugation metabolism of TCE in 16 inbred and one hybrid mouse strains to calibrate and extend existing physiologically-based pharmacokinetic (PBPK) models. We added one-compartment models for glutathione metabolites and a two-compartment model for dichloroacetic acid (DCA). A Bayesian population analysis of inter-strain variability was used to quantify variability in TCE metabolism. Results: Concentration-time profiles for TCE metabolism to oxidative and glutathione conjugation metabolites varied across strains. Median predictions for the metabolic flux through oxidation was less variable (5-fold range) than that through glutathione conjugation (10-fold range). For oxidative metabolites, median predictions of trichloroacetic acid production was less variable (2-fold range) than DCA production (5-fold range), although uncertainty bounds for DCA exceeded the predicted variability. Conclusions:
Chacón, Max; Noh, Sun-Ho; Landerretche, Jean; Jara, José L
2018-01-01
We analyzed the performance of linear and nonlinear models to assess dynamic cerebral autoregulation (dCA) from spontaneous variations in healthy subjects and compared it with the use of two known maneuvers to abruptly change arterial blood pressure (BP): thigh cuffs and sit-to-stand. Cerebral blood flow velocity and BP were measured simultaneously at rest and while the maneuvers were performed in 20 healthy subjects. To analyze the spontaneous variations, we implemented two types of models using support vector machine (SVM): linear and nonlinear finite impulse response models. The classic autoregulation index (ARI) and the more recently proposed model-free ARI (mfARI) were used as measures of dCA. An ANOVA analysis was applied to compare the different methods and the coefficient of variation was calculated to evaluate their variability. There are differences between indexes, but not between models and maneuvers. The mfARI index with the sit-to-stand maneuver shows the least variability. Support vector machine modeling of spontaneous variation with the mfARI index could be used for the assessment of dCA as an alternative to maneuvers to introduce large BP fluctuations.
Allyn, Jérôme; Allou, Nicolas; Augustin, Pascal; Philip, Ivan; Martinet, Olivier; Belghiti, Myriem; Provenchere, Sophie; Montravers, Philippe; Ferdynus, Cyril
2017-01-01
Background The benefits of cardiac surgery are sometimes difficult to predict and the decision to operate on a given individual is complex. Machine Learning and Decision Curve Analysis (DCA) are recent methods developed to create and evaluate prediction models. Methods and finding We conducted a retrospective cohort study using a prospective collected database from December 2005 to December 2012, from a cardiac surgical center at University Hospital. The different models of prediction of mortality in-hospital after elective cardiac surgery, including EuroSCORE II, a logistic regression model and a machine learning model, were compared by ROC and DCA. Of the 6,520 patients having elective cardiac surgery with cardiopulmonary bypass, 6.3% died. Mean age was 63.4 years old (standard deviation 14.4), and mean EuroSCORE II was 3.7 (4.8) %. The area under ROC curve (IC95%) for the machine learning model (0.795 (0.755–0.834)) was significantly higher than EuroSCORE II or the logistic regression model (respectively, 0.737 (0.691–0.783) and 0.742 (0.698–0.785), p < 0.0001). Decision Curve Analysis showed that the machine learning model, in this monocentric study, has a greater benefit whatever the probability threshold. Conclusions According to ROC and DCA, machine learning model is more accurate in predicting mortality after elective cardiac surgery than EuroSCORE II. These results confirm the use of machine learning methods in the field of medical prediction. PMID:28060903
Volumetric Modulated Arc Radiotherapy for Vestibular Schwannomas
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lagerwaard, Frank J.; Meijer, Otto W.M.; Hoorn, Elles A.P. van der
2009-06-01
Purpose: To evaluate volumetric modulated arc radiotherapy (RapidArc [RA]), a novel approach allowing for rapid treatment delivery, for the treatment of vestibular schwannoma (VS). Methods and Materials: The RA plans were generated for a small (0.5 cm{sup 3}), intermediate (2.8 cm{sup 3}), and large (14.8 cm{sup 3}) VS. The prescription dose was 12.5 Gy to the encompassing 80% isodose. The RA plans were compared with conventional radiosurgery plans using both a single dynamic conformal arc (1DCA) and five noncoplanar dynamic conformal arcs (5DCA). Conformity indices (CI) and dose-volume histograms of critical organs were compared. The RA plan for the medium-sizedmore » VS was measured in a phantom using Gafchromic EBT films and compared with calculated dose distributions. Results: The RA planning was completed within 30 min in all cases, and calculated treatment delivery time (after patient setup) was 5 min vs. 20 min for 5DCA. A superior CI was achieved with RA, with a substantial decrease in low-dose irradiation of the normal brain achieved relative to 5DCA plans. Maximum doses to critical organs were similar for RA and 5DCA but were higher for 1DCA. Film measurements showed the differences between calculated and measured doses to be smaller than 1.5% in the high-dose area and smaller than 3% in the low-dose area. Conclusion: The RA plans consistently achieved a higher CI and decrease in areas of low-dose irradiation. This, together with shorter treatment delivery times, has led to RA replacing our conventional five-arc radiosurgery technique for VS.« less
Acquisition Planning at the Defense Communications Agency.
1984-04-01
guidelines for interaction are developed under the leadership of DCA agencywide integrators with the participation of personnel from DCA, the Services...Communications System DCSO - Defense Communications System Organizatin . DDN - Defense Data Network DEC - Decision Making DG - Defense Guidance DIA - Defense
Enhancing MRI of liver metastases with a zwitterionized biodegradable dendritic contrast agent.
Zhou, Xiaoxuan; Ye, Mingzhou; Han, Yuxin; Tang, Jianbin; Qian, Yue; Hu, Hongjie; Shen, Youqing
2017-07-25
Metastasis is the main reason for cancer-associated mortality, and accurate diagnostic imaging of metastases is critical for the clinical administration and tailoring personalized treatments for metastatic tumors. However, magnetic resonance imaging of metastases in the liver is impeded by its low sensitivity because the currently used contrast agents accumulate in hepatocytes and Kupffer cells instead of cancer cells. Herein, a 4 th generation zwitterionized biodegradable dendritic contrast agent (DCA) with a size of ca. 9 nm and a longitudinal relaxivity of 15.7 mM -1 s -1 in terms of Gd was synthesized and used to enhance the MRI of liver metastasis. The DCA could remarkably enhance the MRI of metastasized tumors in the liver, because it could simultaneously reduce the background signal in the liver by avoiding uptake by hepatocytes and Kupffer cells through the zwitterionization and increase the signal in tumors through the enhanced permeability and retention effect. Moreover, in contrast to non-biodegradable DCA, this DCA showed minimal long-term Gd 3+ retention in all organs and tissues because it could be degraded into small fragments. The significant capability of enhancing the MRI of metastases in the liver plus its excellent biodegradability made this DCA a promising CA for metastatic tumor imaging.
Is Dynamic Cerebral Autoregulation Bilaterally Impaired after Unilateral Acute Ischemic Stroke?
Xiong, Li; Tian, Ge; Lin, Wenhua; Wang, Wei; Wang, Lijuan; Leung, Thomas; Mok, Vincent; Liu, Jia; Chen, Xiangyan; Wong, Ka Sing
2017-05-01
Whether dynamic cerebral autoregulation (dCA) is impaired focally in the affected hemisphere or bilaterally in both the affected and nonaffected hemispheres after ischemic stroke remains controversial. We therefore investigated the pattern of dCA in acute ischemic stroke patients with different subtypes. Sixty acute ischemic stroke patients with unilateral anterior circulation infarct [30 with large artery atherosclerosis (LAA), 13 with small vessel disease (SVD), and 17 with coexisting LAA and SVD] and 16 healthy controls were enrolled. Spontaneous arterial blood pressure and cerebral blood flow velocity fluctuations in both bilateral middle cerebral arteries using transcranial Doppler were recorded over 10 minutes. Transfer function analysis was applied to obtain autoregulatory parameters, autoregulation index (ARI), phase difference (PD), and gain. PD was significantly lower on both the ipsilateral and contralateral sides in the LAA group (ipsilateral, 30.74 degrees; contralateral, 29.17 degrees) and the coexisting LAA and SVD group (20.23 degrees; 13.10 degrees) than that in healthy controls (left side, 51.66 degrees; right side, 58.48 degrees) (all P < .05), but there were no significant differences between the 2 sides when compared with each other in all groups. However, in the coexisting LAA and SVD group, phase on both sides was significantly lower when compared with that in the LAA and SVD groups, respectively. The results of ARI were consistent with the findings in PD. The results indicate that dCA is bilaterally impaired in acute ischemic patients with LAA, and the coexisting SVD may aggravate the bilateral impairment of dCA. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Zhang, Fan; Lin, Qiu-Yue; Hu, Wan-Li; Song, Wen-Ji; Shen, Shu-Ting; Gui, Pan
2013-06-01
Three new transition metal complexes [Mn2(DCA)2(bipy)2]·5H2O (1), [M2(DCA)2(bipy)2(H2O)]·10H2O(M = Ni(II)(2);Zn(II)(3)), (DCA = demethylcantharate, 7-oxabicyclo[2,2,1]heptane-2,3-dicarboxylate, C8H8O5) were synthesized and characterized by elemental analysis, molar conductance, infrared spectra and X-ray diffraction techniques. Each metal ion was six-coordinated in complexes. Complex 1 has a Mn2O2 center. Complexes 2 and 3 have asymmetric binuclear structure. Great amount of intermolecular hydrogen-bonding and π-π* stacking interactions were formed in these complex structures. The DNA-binding properties of complexes were investigated by electronic absorption spectra and viscosity measurements. The DNA binding constants Kb/(L mol-1) were 1.71 × 104 (1), 2.62 × 104 (2) and 1.59 × 104 (3) at 298 K. The complexes could quench the intrinsic fluorescence of bovine serum albumin (BSA) strongly through static quenching. The protein binding constants Ka/(L mol-1) were 7.27 × 104 (1), 4.55 × 104 (2) and 7.87 × 104 L mol-1 (3) and binding site was one. The complexes bind more tightly with DNA and BSA than with ligands. Complexes 1 and 3 had stronger inhibition ratios than Na2(DCA) against human hepatoma cells (SMMC-7721) lines and human gastric cancer cells (MGC80-3) lines in vitro. Complex 3 showed the strongest antiproliferative activity against SMMC-7721 (IC50 = 29.46 ± 2.12 μmol L-1) and MGC80-3 (IC50 = 27.02 ± 2.38 μmol L-1), which shows potential in anti-cancer drug development.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bojechko, C.; Ploquin, N.; University of Calgary, Department of Oncology, Tom Baker Cancer Center, Calgary AB
2014-08-15
HybridArc is a relatively novel radiation therapy technique which combines optimized dynamic conformai arcs (DCA) and intensity modulated radiation therapy (IMRT). HybridArc has possible dosimetry and efficiency advantages over stand alone DCA and IMRT treatments and can be readily implemented on any linac capable of DCA and IMRT, giving strong motivation to commission the modality. The Delta4 phantom (Scandidos, Uppsala, Sweden) has been used for IMRT and VMAT clinical dosimetric verification making it a candidate for HybridArc commissioning. However the HybridArc modality makes use of several non co-planar arcs which creates setup issues due to the geometry of the Delta4,more » resulting in possible phantom gantry collisions for plans with non-zero couch angles. An analysis was done determining the feasibility of using the Delta4 fixed at 0° couch angle compared with results obtained using Gafchromic ETB2 film (Ashland, Covington Kentucky) in an anthropomorphic phantom at the planned couch angles. A gamma index analysis of the measured and planned dose distributions was done using Delta4 and DoseLab Pro (Mobius Medical Systems, Houston Texas) software. For both arc and IMRT sub-fields there is reasonable correlation between the gamma index found from the Delta4 and Gafchromic film. All results show the feasibility of using the Delta4 for HybridArc commissioning.« less
Carryover effects of dichloroacetic acid on hepatic tumorigenesis in mice.
Introduction: Dichloroacetic acid (DCA) is a major by-product of drinking water chlorination. Chronic DCA exposure has been shown to increase liver tumors in mice, although carryover effects and interactions with other promotional agents are not known. Here we evaluated effects...
49 CFR 1562.21 - Scope, general requirements, and definitions.
Code of Federal Regulations, 2011 CFR
2011-10-01
... WASHINGTON, DC, METROPOLITAN AREA Ronald Reagan Washington National Airport: Enhanced Security Procedures for... to aircraft operations into or out of Ronald Reagan Washington National Airport (DCA), fixed base... not include an armed security officer. DCA means Ronald Reagan Washington National Airport. DASSP...
49 CFR 1562.21 - Scope, general requirements, and definitions.
Code of Federal Regulations, 2010 CFR
2010-10-01
... WASHINGTON, DC, METROPOLITAN AREA Ronald Reagan Washington National Airport: Enhanced Security Procedures for... to aircraft operations into or out of Ronald Reagan Washington National Airport (DCA), fixed base... not include an armed security officer. DCA means Ronald Reagan Washington National Airport. DASSP...
49 CFR 1562.21 - Scope, general requirements, and definitions.
Code of Federal Regulations, 2014 CFR
2014-10-01
... WASHINGTON, DC, METROPOLITAN AREA Ronald Reagan Washington National Airport: Enhanced Security Procedures for... operators located at DCA or gateway airports; individuals designated as a security coordinator by aircraft... not include an armed security officer. DCA means Ronald Reagan Washington National Airport. DASSP...
49 CFR 1562.21 - Scope, general requirements, and definitions.
Code of Federal Regulations, 2012 CFR
2012-10-01
... WASHINGTON, DC, METROPOLITAN AREA Ronald Reagan Washington National Airport: Enhanced Security Procedures for... operators located at DCA or gateway airports; individuals designated as a security coordinator by aircraft... not include an armed security officer. DCA means Ronald Reagan Washington National Airport. DASSP...
49 CFR 1562.21 - Scope, general requirements, and definitions.
Code of Federal Regulations, 2013 CFR
2013-10-01
... WASHINGTON, DC, METROPOLITAN AREA Ronald Reagan Washington National Airport: Enhanced Security Procedures for... operators located at DCA or gateway airports; individuals designated as a security coordinator by aircraft... not include an armed security officer. DCA means Ronald Reagan Washington National Airport. DASSP...
Yamada, Shunsuke; Ueki, Kenji; Tokumoto, Masanori; Suehiro, Takaichi; Kimura, Hiroshi; Taniguchi, Masatomo; Fujimi, Satoru; Kitazono, Takanari; Tsuruya, Kazuhiko
2016-02-01
Selection of a lower dialysate calcium concentration (DCa) can reduce calcium burden and prevent vascular calcification in hemodialysis patients. However, decreased DCa can worsen mineral and bone disorders. This 1-year retrospective observational study evaluated 121 hemodialysis patients at Fukuoka Renal Clinic who underwent conversion of DCa from 3.0 mEq/L to 2.75 mEq/L. The primary outcomes were changes in serum levels of calcium, phosphate, and parathyroid hormone (PTH). The effects of baseline serum calcium and PTH levels on changes in biochemical parameters were also determined. One year after DCa conversion, mean serum calcium level decreased, while serum phosphate, alkaline phosphatase, and PTH concentrations increased. The rate of achievement of target PTH was higher in patients with lower serum PTH level at baseline, while patients with higher baseline serum PTH level tended to exceed the upper limit of the PTH target range. Patients with higher baseline serum calcium concentration showed a greater decrease in serum calcium level and a greater increase in serum PTH level at 1 year. Patients with a lower baseline serum PTH level can benefit from optimal PTH control following conversion of DCa from 3.0 mEq/L to 2.75 mEq/L. However, secondary hyperparathyroidism may be exacerbated in some patients with higher baseline serum calcium (Ca) and PTH levels. These results indicate that an individualized approach can maximize the benefits of Ca unloading after conversion to lower DCa. © 2015 International Society for Apheresis, Japanese Society for Apheresis, and Japanese Society for Dialysis Therapy.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhu, Yingting, E-mail: yitizhu@yahoo.com; Tissue Tech Inc., Miami, FL 33173; Zhu, Min
2012-08-31
Highlights: Black-Right-Pointing-Pointer Human colonic cancer associated fibroblasts are major sources of COX-2 and PGE{sub 2}. Black-Right-Pointing-Pointer The fibroblasts interact with human colonic epithelial cancer cells. Black-Right-Pointing-Pointer Activation of COX-2 signaling in the fibroblasts affects behavior of the epithelia. Black-Right-Pointing-Pointer Protein Kinase C controls the activation of COX-2 signaling. -- Abstract: COX-2 is a major regulator implicated in colonic cancer. However, how COX-2 signaling affects colonic carcinogenesis at cellular level is not clear. In this article, we investigated whether activation of COX-2 signaling by deoxycholic acid (DCA) in primary human normal and cancer associated fibroblasts play a significant role in regulationmore » of proliferation and invasiveness of colonic epithelial cancer cells. Our results demonstrated while COX-2 signaling can be activated by DCA in both normal and cancer associated fibroblasts, the level of activation of COX-2 signaling is significantly greater in cancer associated fibroblasts than that in normal fibroblasts. In addition, we discovered that the proliferative and invasive potential of colonic epithelial cancer cells were much greater when the cells were co-cultured with cancer associated fibroblasts pre-treated with DCA than with normal fibroblasts pre-treated with DCA. Moreover, COX-2 siRNA attenuated the proliferative and invasive effect of both normal and cancer associate fibroblasts pre-treated with DCA on the colonic cancer cells. Further studies indicated that the activation of COX-2 signaling by DCA is through protein kinase C signaling. We speculate that activation of COX-2 signaling especially in cancer associated fibroblasts promotes progression of colonic cancer.« less
Lajczak, Natalia K; Saint-Criq, Vinciane; O'Dwyer, Aoife M; Perino, Alessia; Adorini, Luciano; Schoonjans, Kristina; Keely, Stephen J
2017-09-01
Bile acids and epithelial-derived human β-defensins (HβDs) are known to be important factors in the regulation of colonic mucosal barrier function and inflammation. We hypothesized that bile acids regulate colonic HβD expression and aimed to test this by investigating the effects of deoxycholic acid (DCA) and ursodeoxycholic acid on the expression and release of HβD1 and HβD2 from colonic epithelial cells and mucosal tissues. DCA (10-150 µM) stimulated the release of both HβD1 and HβD2 from epithelial cell monolayers and human colonic mucosal tissue in vitro In contrast, ursodeoxycholic acid (50-200 µM) inhibited both basal and DCA-induced defensin release. Effects of DCA were mimicked by the Takeda GPCR 5 agonist, INT-777 (50 μM), but not by the farnesoid X receptor agonist, GW4064 (10 μM). INT-777 also stimulated colonic HβD1 and HβD2 release from wild-type, but not Takeda GPCR 5 -/- , mice. DCA stimulated phosphorylation of the p65 subunit of NF-κB, an effect that was attenuated by ursodeoxycholic acid, whereas an NF-κB inhibitor, BMS-345541 (25 μM), inhibited DCA-induced HβD2, but not HβD1, release. We conclude that bile acids can differentially regulate colonic epithelial HβD expression and secretion and discuss the implications of our findings for intestinal health and disease.-Lajczak, N. K., Saint-Criq, V., O'Dwyer, A. M., Perino, A., Adorini, L., Schoonjans, K., Keely, S. J. Bile acids deoxycholic acid and ursodeoxycholic acid differentially regulate human β-defensin-1 and -2 secretion by colonic epithelial cells. © FASEB.
Selective removal of monoterpenes from bergamot oil by inclusion in deoxycholic acid.
Fantin, Giancarlo; Fogagnolo, Marco; Maietti, Silvia; Rossetti, Stefano
2010-05-12
A new approach for removing monoterpenes (MTs) from bergamot oil by selective inclusion in deoxycholic acid (DCA) is proposed. The inclusion process is very efficient, the included fraction being composed mainly of limonene (71.7%) and gamma-terpinene (19.8%). On the other hand, the deterpenated bergamot oil fraction showed for the linalool and linalyl acetate derivatives significant increases from 16.6 and 21.4% to 18.3 and 42.2%, respectively. The major advantages of this methodology are its simplicity, the mild conditions employed, and the quantitative recovery of both host (DCA) and guest (monoterpenes) compounds. Differential scanning calorimetry (DSC), thermal gravimetry (TG), powder X-ray diffractometry (XRPD), infrared spectroscopy (IR), and proton magnetic resonance ((1)H NMR) analysis were used to investigate and characterize the inclusion compounds.
GENOTOXICITY STUDIES OF SODIUM DICHLOROACETATE AND SODIUM TRICHLOROACETATE
The genotoxic properties of sodium dichloroacetate (DCA) and sodium trichloroacetate (TCA)were evaluated in several short-term in vitro and in vivo assays. Neither compound was mutagenic in tester strain TA102 in the Salmonella mutagenicity assay. Both DCA and TCA were weak induc...
Washington, D.C. - Local Information | NREL
International Airport (IAD), and Baltimore/Washington International Thurgood Marshall Airport (BWI). DCA is the additional information. Reagan National Airport - DCA Dulles International Airport - IAD Baltimore/Washington International Thurgood Marshall Airport - BWI Public Transportation The Washington Metropolitan Area Transit
NASA Astrophysics Data System (ADS)
Bikkina, Srinivas; Kawamura, Kimitaka; Miyazaki, Yuzo; Fu, Pingqing
2014-05-01
Atmospheric dicarboxylic acids (DCA) are a ubiquitous water-soluble component of secondary organic aerosols (SOA), which can act as cloud condensation nuclei (CCN), affecting the Earth's climate. Despite the high abundances of oxalic acid and related compounds in the marine aerosols, there is no consensus on what controls their distributions over the open ocean. Marine biological productivity could play a role in the production of DCA, but there is no substantial evidence to support this hypothesis. Here we present latitudinal distributions of DCA, oxoacids and α-dicarbonyls in the marine aerosols from the remote Pacific. Their concentrations were found several times higher in more biologically influenced aerosols (MBA) than less biologically influenced aerosols. We propose isoprene and unsaturated fatty acids as sources of DCA as inferred from significantly higher abundances of isoprene-SOA tracers and azelaic acid in MBA. These results have implications toward the reassessment of climate forcing feedbacks of marine-derived SOA.
NASA Astrophysics Data System (ADS)
Salleh, R. M.; Jamaludin, S. N.
2018-05-01
Solubility data of carbon dioxide (CO2) in aqueous Diethanolamine (DEA) blended with pyrrolidinium-based ionic liquid: N-Butyl-1-Methylpyrrolidinium Dıcyanamıde [Bmpyrr][DCA] are presented at various temperatures (313.15K-333.15K) and pressure up to about 700 psi. The concentration of [Bmpyrr][DCA] ranges from 0-10wt% and 30-40wt% for DEA. The solubility of CO2 was evaluated by measuring the pressure drop in high pressure stirred absorption cell reactor. The CO2 loading in all studied mixtures increases with an increase in CO2 partial pressure and decreases with temperature. It was also found that the CO2 loading capacity decrease as the concentration of [Bmpyrr][DCA] increases. The experimental data were correlated as a function of temperature and CO2 partial pressure to predict the solubility of CO2 in the mixtures. It was found that the model predicted results in a good agreement with experimental value.
Centuori, Sara M; Martinez, Jesse D
2014-10-01
A high-fat diet coincides with increased levels of bile acids. This increase in bile acids, particularly deoxycholic acid (DCA), has been strongly associated with the development of colon cancer. Conversely, ursodeoxycholic acid (UDCA) may have chemopreventive properties. Although structurally similar, DCA and UDCA present different biological and pathological effects in colon cancer progression. The differential regulation of cancer by these two bile acids is not yet fully understood. However, one possible explanation for their diverging effects is their ability to differentially regulate signaling pathways involved in the multistep progression of colon cancer, such as the epidermal growth factor receptor (EGFR)-mitogen-activated protein kinase (MAPK) pathway. This review will examine the biological effects of DCA and UDCA on colon cancer development, as well as the diverging effects of these bile acids on the oncogenic signaling pathways that play a role in colon cancer development, with a particular emphasis on bile acid regulation of the EGFR-MAPK pathway.
Centuori, Sara M.; Martinez, Jesse D.
2014-01-01
A high fat diet coincides with elevated levels of bile acids. This elevation of bile acids, particularly deoxycholic acid (DCA), has been strongly associated with the development of colon cancer. Conversely, ursodeoxycholic acid (UDCA) may have chemopreventive properties. Although structurally similar, DCA and UDCA present different biological and pathological effects in colon cancer progression. The differential regulation of cancer by these two bile acids is not yet fully understood. However, one possible explanation for their diverging effects is their ability to differentially regulate signaling pathways involved in the multistep progression of colon cancer, such as the epidermal growth factor receptor (EGFR) mitogen-activated protein kinase (MAPK) pathway. This review will examine the biological effects of DCA and UDCA on colon cancer development, as well as the diverging effects of these bile acids on the oncogenic signaling pathways that play a role in colon cancer development, with a particular emphasis on bile acid regulation of the EGFR-MAPK pathway. PMID:25027205
Microbial Transformation of Dicarboxylic Acids by Airborne Bacteria
NASA Astrophysics Data System (ADS)
Cote, V.; Ariya, P.
2004-05-01
Organic aerosols are assumed to be key players in driving climatic changes and can cause health problems for human. Dicarboxylic acids (DCA) include a large fraction of identified important class of organic aerosols. In addition to direct sources, DCA are partly formed as the result of ozonolysis of terpenes and cyclic alkenes. Previous works in our laboratory show that airborne fungi collected from urban and suburban air play an important role in the transformation of severals organic aerosols such as DCA. Our present study focuses on understanding the potential chemical transformation induced by airborne bacteria and on identification of the transformation products. Airborne bacteria have been collected using a biosampler and cultivated on a solid media. Each bacterial colony is being tested by HPLC for their ability to transform DCA in liquid cultures. Also, GC-MS, SPME and NMR are being used to identify the metabolites generated from the transformation. We will present our preliminary results and we will discuss the application of bacterial activities on the chemical transformation of organics in atmosphere.
Comparison between DCA - SSO - VDR and VMAT dose delivery techniques for 15 SRS/SRT patients
NASA Astrophysics Data System (ADS)
Tas, B.; Durmus, I. F.
2018-02-01
To evaluate dose delivery between Dynamic Conformal Arc (DCA) - Segment Shape Optimization (SSO) - Variation Dose Rate (VDR) and Volumetric Modulated Arc Therapy (VMAT) techniques for fifteen SRS patients using Versa HD® lineer accelerator. Fifteen SRS / SRT patient's optimum treatment planning were performed using Monaco5.11® treatment planning system (TPS) with 1 coplanar and 3 non-coplanar fields for VMAT technique, then the plans were reoptimized with the same optimization parameters for DCA - SSO - VDR technique. The advantage of DCA - SSO - VDR technique were determined less MUs and beam on time, also larger segments decrease dosimetric uncertainities of small fields quality assurance. The advantage of VMAT technique were determined a little better GI, CI, PCI, brain V12Gy and brain mean dose. The results show that the clinical objectives and plans for both techniques satisfied all organs at risks (OARs) dose constraints. Depends on the shape and localization of target, we could choose one of these techniques for linear accelerator based SRS / SRT treatment.
Zhang, Shu; Hou, Zhen; Du, Xiao-Ming; Li, Dong-Ming; Lu, Xiao-Xia
2016-11-01
Site in a former chemical manufacture plant in China was found contaminated with high level of chlorinated volatile organic compounds (CVOCs). The major contaminants chloroform (CF), 1,2-dichloroethane (1,2-DCA) and vinyl chloride (VC) in groundwater were up to 4.49 × 10 4 , 2.76 × 10 6 and 4.35 × 10 4 μg/L, respectively. Ethene and methane were at concentrations up to 2219.80 and 165.85 μg/L, respectively. To test the hypothesis that the CVOCs in groundwater at this site could be removed via biodegradation, biomarker analyses and microcosm studies were conducted. Dehalococcoides 16S rRNA gene and VC-reductase gene vcrA at densities up to 1.5 × 10 4 and 3.2 × 10 4 copies/L were detected in some of the groundwater samples, providing strong evidence that dechlorinating bacteria were present in the aquifer. Results from the microcosm studies showed that at moderate concentrations (CF about 4000 μg/L and 1,2-DCA about 100 μg/L), CF was recalcitrant under natural condition but was degraded under biostimulation and bioaugmentation, while 1,2-DCA was degraded under all the three conditions. At high concentration (CF about 1,000,000 μg/L and 1,2-DCA about 20,000 μg/L), CF was recalcitrant under all the three treatments and 1,2-DCA was only degraded under bioaugmentation, indicating that high concentrations of contaminants were inhibitory to the bacteria. Electron donors had influence on the degradation of contaminants. Of the four fatty acids (pyruvate, acetate, propionate and lactate) examined, all could stimulate the degradation of 1,2-DCA at both moderate and high concentrations, whereas only pyruvate and acetate could stimulate the degradation of CF at moderate concentration. In the microcosms, the observed first-order degradation rates of CF and 1,2-DCA were up to 0.12 and 0.11/day, respectively. Results from the present study provided scientific basis for remediating CVOCs contaminated groundwater at the site.
Begić, Srđan; Jónsson, Erlendur; Chen, Fangfang; Forsyth, Maria
2017-11-15
Understanding the electrode-electrolyte interface is essential in the battery research as the ion transport and ion structures at the interface most likely affect the performance of a battery. Here we investigate interfacial structures of three ionic liquids: 1-ethyl-3-methylimidazolium dicyanamide ([C 2 mim][dca]), 1-butyl-3-methylimidazolium dicyanamide ([C 4 mim][dca]) and N-butyl-N-methylpyrrolidinium dicyanamide ([C 4 myr][dca]) at a charged and uncharged graphene interface using molecular dynamics simulations. We find that these ionic liquids (ILs) behave differently both in the bulk phase and near a graphene interface and we find that this difference is apparent in all types of analyses performed here. First, a partial density analysis in the direction perpendicular to the surface of the electrodes, which, in the cases near a negatively charged graphene, reveals that the pyrrolidinium system is generally more layered than the imidazolium systems. Second, a 2D topographic structure analysis of the IL species in the inner layer near a negatively charged graphene surface, which reveals that the pyrrolidinium system exhibits a quasi-hexagonal surface configuration of the cations, while the imidazolium systems show linearly arranged groups of cations. Third, a 3D orientation-preference analysis of cation rings near the negative graphene electrode, which shows that the pyrrolidinium rings prefer to lie parallel to the electrode surface while the imidazolium rings prefer to stand on the electrode surface at high tilt angles. Extending the imidazolium alkyl chain was found to reduce the number of imidazoliums that can link up into linearly arranged groups in the inner layer 2D structures. Our results support earlier experimental findings and indicate that the interfacial nanostructures may have a significant influence on the electrochemical performance of IL-based batteries.
Administration of dichloroacetate (DCA) to pregnant rats produces craniofacial, heart and other defects in their offspring. Exposure of zebrafish to DCA induces malformations and increases superoxide and nitric oxide production suggesting that reactive oxygen species (ROS) are as...
Updates on the EPA Study of Lead Scavengers (EDB and DCA)
In response to continued concerns about the concentrations of 1,2-dibromoethane (EDB) in ground water from spills of leaded gasoline, OUST formed a Lead Scavengers Team with assistance from ASTSWMO. ASTSWMO and EPA Regions solicited participation from state agencies. Analysis w...
EARLY GENE EXPRESSION CHANGES IN THE LIVERS OF MICE EXPOSED TO DICHLOROACETIC ACID
EARLY GENE EXPRESSION CHANGES IN THE LIVERS OF MICE EXPOSED TO DICHLOROACETIC ACID
Dichloroacetic acid (DCA) is a major by-product of water disinfection by chlorination. Several studies have shown that DCA induces liver tumors in rodents when administered in drinking wate...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-15
... Environmental Review for Standard Terminal Arrival Route Procedures for Ronald Reagan Washington National... Ronald Reagan Washington National Airport (DCA). As required by the National Environmental Policy Act, an...), TRUPS1 (RNAV), and NUMMY. Location: Ronald Reagan Washington National Airport (DCA). This project...
Apoptosis and Proliferation During DicWoroacetic Acid (DCA) Induced Hepatocellular
Carcinogenesis in the F344 Male Rat
Chlorine, introduced into public drinking \\\\'ater supplies for disinfection, can react with organic compounds in surface waters to form toxic by-prod...
NASA Astrophysics Data System (ADS)
Wang, Jinman; Wang, Hongdan; Cao, Yingui; Bai, Zhongke; Qin, Qian
2016-02-01
Vegetation plays an important role in improving and restoring fragile ecological environments. In the Antaibao opencast coal mine, located in a loess area, the eco-environment has been substantially disturbed by mining activities, and the relationship between the vegetation and environmental factors is not very clear. Therefore, it is crucial to understand the effects of soil and topographic factors on vegetation restoration to improve the fragile ecosystems of damaged land. An investigation of the soil, topography and vegetation in 50 reclamation sample plots in Shanxi Pingshuo Antaibao opencast coal mine dumps was performed. Statistical analyses in this study included one-way ANOVA and significance testing using SPSS 20.0, and multivariate techniques of detrended correspondence analysis (DCA) and redundancy analysis (RDA) using CANOCO 4.5. The RDA revealed the environmental factors that affected vegetation restoration. Various vegetation and soil variables were significantly correlated. The available K and rock content were good explanatory variables, and they were positively correlated with tree volume. The effects of the soil factors on vegetation restoration were higher than those of the topographic factors.
Wang, Jinman; Wang, Hongdan; Cao, Yingui; Bai, Zhongke; Qin, Qian
2016-01-01
Vegetation plays an important role in improving and restoring fragile ecological environments. In the Antaibao opencast coal mine, located in a loess area, the eco-environment has been substantially disturbed by mining activities, and the relationship between the vegetation and environmental factors is not very clear. Therefore, it is crucial to understand the effects of soil and topographic factors on vegetation restoration to improve the fragile ecosystems of damaged land. An investigation of the soil, topography and vegetation in 50 reclamation sample plots in Shanxi Pingshuo Antaibao opencast coal mine dumps was performed. Statistical analyses in this study included one-way ANOVA and significance testing using SPSS 20.0, and multivariate techniques of detrended correspondence analysis (DCA) and redundancy analysis (RDA) using CANOCO 4.5. The RDA revealed the environmental factors that affected vegetation restoration. Various vegetation and soil variables were significantly correlated. The available K and rock content were good explanatory variables, and they were positively correlated with tree volume. The effects of the soil factors on vegetation restoration were higher than those of the topographic factors. PMID:26916152
Wang, Jinman; Wang, Hongdan; Cao, Yingui; Bai, Zhongke; Qin, Qian
2016-02-26
Vegetation plays an important role in improving and restoring fragile ecological environments. In the Antaibao opencast coal mine, located in a loess area, the eco-environment has been substantially disturbed by mining activities, and the relationship between the vegetation and environmental factors is not very clear. Therefore, it is crucial to understand the effects of soil and topographic factors on vegetation restoration to improve the fragile ecosystems of damaged land. An investigation of the soil, topography and vegetation in 50 reclamation sample plots in Shanxi Pingshuo Antaibao opencast coal mine dumps was performed. Statistical analyses in this study included one-way ANOVA and significance testing using SPSS 20.0, and multivariate techniques of detrended correspondence analysis (DCA) and redundancy analysis (RDA) using CANOCO 4.5. The RDA revealed the environmental factors that affected vegetation restoration. Various vegetation and soil variables were significantly correlated. The available K and rock content were good explanatory variables, and they were positively correlated with tree volume. The effects of the soil factors on vegetation restoration were higher than those of the topographic factors.
Demersal fish assemblages off southern New Zealand in relation to depth and temperature
NASA Astrophysics Data System (ADS)
Jacob, W.; McClatchie, S.; Probert, P. K.; Hurst, R. J.
1998-12-01
We examined the relationship between demersal fish assemblage and depth, temperature, latitude and longitude off southern New Zealand (46-54°S and 165-180°E) in water depths of 80-787 m. Catch weight data were analysed by two-way indicator analysis (TWIA), groupaverage agglomerative clustering (UPGMA) and Detrended Correspondence Analysis (DCA). The spatial pattern of demersal fish off southern New Zealand conforms to the concept of species groups or fish assemblages related to environmental gradients. Shallow-water assemblages were dominated by species from the families Gempylidae, Squalidae, Triakidae and Moridae, mainly represented by Thyrsites atun, Squalus acanthias, Galeorhinus australis, and Pseudophycis bachus. Deep water assemblages were dominated by Chimaeridae, Argentinidae, Merlucciidae and Macrouridae, mainly represented by Hydrolagus novaezelandiae, Argentina elongata, Macruronus novaezelandiae, and Lepidorhynchus denticulatus. Total catch weight was often dominated by Merlucciidae, Macrouridae and Gempylidae. Fish assemblages were related to discrete ranges of depth (< and >300 m) and temperature (< and >9.5°C), but the range of sediment types was too narrow to show any correlation.
Sardella, Roccaldo; Gioiello, Antimo; Ianni, Federica; Venturoni, Francesco; Natalini, Benedetto
2012-10-15
The employment of the flow N-acyl amidation of natural bile acids (BAs) required the in-line connection with suitable analytical tools enabling the determination of reaction yields as well as of the purity grade of the synthesized glyco- and tauro-conjugated derivatives. In this framework, a unique HPLC method was successfully established and validated for ursodeoxycholic (UDCA), chenodeoxycholic (CDCA), deoxycholic (DCA) and cholic (CA) acids, as well as the corresponding glyco- and tauro-conjugated forms. Because of the shared absence of relevant chromophoric moieties in the sample structure, an evaporative light scattering detector (ELSD) was profitably utilized for the analysis of such steroidal species. For each of the investigated compounds, all the runs were contemporarily carried out on the acidic free and the two relative conjugated variants. The different ELSD response of the free and the corresponding conjugated BAs, imposed to build-up separate calibration curves. In all the cases, very good precision (RSD% values ranging from 1.04 to 6.40% in the long-period) and accuracy (Recovery% values ranging from 96.03 to 111.14% in the long-period) values along with appreciably low LOD and LOQ values (the former being within the range 1-27 ng mL(-1) and the latter within the range 2-44 ng mL(-1)) turned out. Copyright © 2012 Elsevier B.V. All rights reserved.
Aquatic vegetation and trophic condition of Cape Cod (Massachusetts, U.S.A.) kettle ponds
Roman, C.T.; Barrett, N.E.; Portnoy, J.W.
2001-01-01
The species composition and relative abundance of aquatic macrophytes was evaluated in five Cape Cod, Massachusetts, freshwater kettle ponds, representing a range of trophic conditions from oligotrophic to eutrophic. At each pond, aquatic vegetation and environmental variables (slope, water depth, sediment bulk density, sediment grain size, sediment organic content and porewater inorganic nutrients) were measured along five transects extending perpendicular to the shoreline from the upland border into the pond. Based on a variety of multivariate methods, including Detrended Correspondence Analysis (DCA), an indirect gradient analysis technique, and Canonical Correspondence Analysis (CCA), a direct gradient approach, it was determined that the eutrophic Herring Pond was dominated by floating aquatic vegetation (Brasenia schreberi, Nymphoides cordata, Nymphaea odorata), and the algal stonewort, Nitella. Partial CCA suggested that high porewater PO4-P concentrations and fine-grained sediments strongly influenced the vegetation of this eutrophic pond. In contrast, vegetation of the oligotrophic Duck Pond was sparse, contained no floating aquatics, and was dominated by emergent plants. Low porewater nutrients, low sediment organic content, high water clarity and low pH (4.8) best defined the environmental characteristics of this oligotrophic pond. Gull Pond, with inorganic nitrogen-enriched sediments, also exhibited a flora quite different from the oligotrophic Duck Pond. The species composition and relative abundance of aquatic macrophytes provide good indicators of the trophic status of freshwater ponds and should be incorporated into long-term monitoring programs aimed at detecting responses to anthropogenically-derived nutrient loading.
Aquatic vegetation and trophic condition of Cape Cod (Massachusetts, USA) kettle ponds
Roman, C.T.; Barrett, N.E.; Portnoy, J.W.
2001-01-01
The species composition and relative abundance of aquatic macrophytes was evaluated in five Cape Cod, Massachusetts, freshwater kettle ponds, representing a range of trophic conditions from oligotrophic to eutrophic. At each pond, aquatic vegetation and environmental variables (slope, water depth, sediment bulk density, sediment grain size, sediment organic content and porewater inorganic nutrients) were measured along five transects extending perpendicular to the shoreline from the upland border into the pond. Based on a variety of multivariate methods, including Detrended Correspondence Analysis (DCA), an indirect gradient analysis technique, and Canonical Correspondence Analysis (CCA), a direct gradient approach, it was determined that the eutrophic Herring Pond was dominated by floating aquatic vegetation (Brasenia schreberi, Nymphoides cordata, Nymphaea odorata), and the algal stonewort, Nitella. Partial CCA suggested that high porewater PO4-P concentrations and fine-grained sediments strongly influenced the vegetation of this eutrophic pond. In contrast, vegetation of the oligotrophic Duck Pond was sparse, contained no floating aquatics, and was dominated by emergent plants. Low porewater nutrients, low sediment organic content, high water clarity and low pH (4.8) best defined the environmental characteristics of this oligotrophic pond. Gull Pond, with inorganic nitrogen-enriched sediments, also exhibited a flora quite different from the oligotrophic Duck Pond. The species composition and relative abundance of aquatic macrophytes provide good indicators of the trophic status of freshwater ponds and should be incorporated into long-term monitoring programs aimed at detecting responses to anthropogenically-derived nutrient loading.
Removal of EDB and 1,2-DCA by Abiotic Reaction with Iron (II) Sulfide
To properly evaluate the risk associated with exposure to EDB and 1,2-DCA in ground water from old spills of leaded gasoline, it is necessary to understand the mechanisms that may attenuate concentrations of these compounds in ground water. TCE reacts rapidly with iron (II) sulf...
Mediouni, Sonia; Jablonski, Joseph; Paris, Jason J.; Clementz, Mark A.; Thenin-Houssier, Suzie; McLaughlin, Jay P.; Valente, Susana T.
2015-01-01
HIV-1 Tat protein has been shown to have a crucial role in HIV-1-associated neurocognitive disorders (HAND), which includes a group of syndromes ranging from undetectable neurocognitive impairment to dementia. The abuse of psychostimulants, such as cocaine, by HIV infected individuals, may accelerate and intensify neurological damage. On the other hand, exposure to Tat potentiates cocaine-mediated reward mechanisms, which further promotes HAND. Here, we show that didehydro-Cortistatin A (dCA), an analog of a natural steroidal alkaloid, crosses the blood-brain barrier, cross-neutralizes Tat activity from several HIV-1 clades and decreases Tat uptake by glial cell lines. In addition, dCA potently inhibits Tat mediated dysregulation of IL-1β, TNF-α and MCP-1, key neuroinflammatory signaling proteins. Importantly, using a mouse model where doxycycline induces Tat expression, we demonstrate that dCA reverses the potentiation of cocaine-mediated reward. Our results suggest that adding a Tat inhibitor, such as dCA, to current antiretroviral therapy may reduce HIV-1-related neuropathogenesis. PMID:25613133
Thewes, Fabio Rodrigo; Brackmann, Auri; Anese, Rogerio de Oliveira; Ludwig, Vagner; Schultz, Erani Eliseu; Dos Santos, Luana Ferreira; Wendt, Lucas Mallmann
2017-05-01
The objective of this study was to evaluate the interaction between controlled atmosphere (CA), CA+1-methylcyclopropene (1-MCP) and dynamic controlled atmosphere monitored by respiratory quotient (DCA-RQ) with three fruit maturity stages at harvest (early harvest date, optimal harvest date and late harvest date) on 'Galaxy' apple metabolism and quality after harvest and 9months storage plus 7days of shelf life at 20°C. Fruit stored under dynamic controlled atmosphere monitored by respiratory quotient 1.3 (DCA-RQ 1.3) showed lower ethylene production, respiration rate, mealiness and higher flesh firmness in comparison to CA stored fruit, but did not differ from those treated with 1-MCP. The dynamic controlled atmosphere monitored by respiratory quotient 1.5 (DCA-RQ 1.5) increased the acetaldehyde, ethanol and ethyl acetate concentration, regardless of the fruit maturity at harvest. The storage of 'Galaxy' apple under DCA-RQ 1.3 is efficient in keeping quality regardless of the maturity stage at harvest. Copyright © 2016 Elsevier Ltd. All rights reserved.
A distinct entorhinal cortex to hippocampal CA1 direct circuit for olfactory associative learning.
Li, Yiding; Xu, Jiamin; Liu, Yafeng; Zhu, Jia; Liu, Nan; Zeng, Wenbo; Huang, Ning; Rasch, Malte J; Jiang, Haifei; Gu, Xiang; Li, Xiang; Luo, Minhua; Li, Chengyu; Teng, Junlin; Chen, Jianguo; Zeng, Shaoqun; Lin, Longnian; Zhang, Xiaohui
2017-04-01
Lateral and medial parts of entorhinal cortex (EC) convey nonspatial 'what' and spatial 'where' information, respectively, into hippocampal CA1, via both the indirect EC layer 2→ hippocampal dentate gyrus→CA3→CA1 and the direct EC layer 3→CA1 paths. However, it remains elusive how the direct path transfers distinct information and contributes to hippocampal learning functions. Here we report that lateral EC projection neurons selectively form direct excitatory synapses onto a subpopulation of morphologically complex, calbindin-expressing pyramidal cells (PCs) in the dorsal CA1 (dCA1), while medial EC neurons uniformly innervate all dCA1 PCs. Optogenetically inactivating the distinct lateral EC-dCA1 connections or the postsynaptic dCA1 calbindin-expressing PC activity slows olfactory associative learning. Moreover, optetrode recordings reveal that dCA1 calbindin-expressing PCs develop more selective spiking responses to odor cues during learning. Thus, our results identify a direct lateral EC→dCA1 circuit that is required for olfactory associative learning.
Engineering a Catabolic Pathway in Plants for the Degradation of 1,2-Dichloroethane1[OA
Mena-Benitez, Gilda L.; Gandia-Herrero, Fernando; Graham, Stuart; Larson, Tony R.; McQueen-Mason, Simon J.; French, Christopher E.; Rylott, Elizabeth L.; Bruce, Neil C.
2008-01-01
Plants are increasingly being employed to clean up environmental pollutants such as heavy metals; however, a major limitation of phytoremediation is the inability of plants to mineralize most organic pollutants. A key component of organic pollutants is halogenated aliphatic compounds that include 1,2-dichloroethane (1,2-DCA). Although plants lack the enzymatic activity required to metabolize this compound, two bacterial enzymes, haloalkane dehalogenase (DhlA) and haloacid dehalogenase (DhlB) from the bacterium Xanthobacter autotrophicus GJ10, have the ability to dehalogenate a range of halogenated aliphatics, including 1,2-DCA. We have engineered the dhlA and dhlB genes into tobacco (Nicotiana tabacum ‘Xanthi’) plants and used 1,2-DCA as a model substrate to demonstrate the ability of the transgenic tobacco to remediate a range of halogenated, aliphatic hydrocarbons. DhlA converts 1,2-DCA to 2-chloroethanol, which is then metabolized to the phytotoxic 2-chloroacetaldehyde, then chloroacetic acid, by endogenous plant alcohol dehydrogenase and aldehyde dehydrogenase activities, respectively. Chloroacetic acid is dehalogenated by DhlB to produce the glyoxylate cycle intermediate glycolate. Plants expressing only DhlA produced phytotoxic levels of chlorinated intermediates and died, while plants expressing DhlA together with DhlB thrived at levels of 1,2-DCA that were toxic to DhlA-expressing plants. This represents a significant advance in the development of a low-cost phytoremediation approach toward the clean-up of halogenated organic pollutants from contaminated soil and groundwater. PMID:18467461
Specific bile acids inhibit hepatic fatty acid uptake
Nie, Biao; Park, Hyo Min; Kazantzis, Melissa; Lin, Min; Henkin, Amy; Ng, Stephanie; Song, Sujin; Chen, Yuli; Tran, Heather; Lai, Robin; Her, Chris; Maher, Jacquelyn J.; Forman, Barry M.; Stahl, Andreas
2012-01-01
Bile acids are known to play important roles as detergents in the absorption of hydrophobic nutrients and as signaling molecules in the regulation of metabolism. Here we tested the novel hypothesis that naturally occurring bile acids interfere with protein-mediated hepatic long chain free fatty acid (LCFA) uptake. To this end stable cell lines expressing fatty acid transporters as well as primary hepatocytes from mouse and human livers were incubated with primary and secondary bile acids to determine their effects on LCFA uptake rates. We identified ursodeoxycholic acid (UDCA) and deoxycholic acid (DCA) as the two most potent inhibitors of the liver-specific fatty acid transport protein 5 (FATP5). Both UDCA and DCA were able to inhibit LCFA uptake by primary hepatocytes in a FATP5-dependent manner. Subsequently, mice were treated with these secondary bile acids in vivo to assess their ability to inhibit diet-induced hepatic triglyceride accumulation. Administration of DCA in vivo via injection or as part of a high-fat diet significantly inhibited hepatic fatty acid uptake and reduced liver triglycerides by more than 50%. In summary, the data demonstrate a novel role for specific bile acids, and the secondary bile acid DCA in particular, in the regulation of hepatic LCFA uptake. The results illuminate a previously unappreciated means by which specific bile acids, such as UDCA and DCA, can impact hepatic triglyceride metabolism and may lead to novel approaches to combat obesity-associated fatty liver disease. PMID:22531947
Sorathia, Fena; Rajput, Prashant; Gupta, Tarun
2018-05-15
This study assesses daytime and nighttime atmospheric abundance and molecular distribution of dicarboxylic acids (DCA: C 2 -C 10 ) and biomass burning tracers (levoglucosan and biomass burning derived potassium: K + BB ) in PM 10 (particulate matter with aerodynamic diameter≤10μm) from an urban location, Kanpur (in central Indo-Gangetic Plain: IGP) during wintertime (December 2015-February 2016). In this study, PM 10 varied from 130 to 242 and 175-388μgm -3 during daytime and nighttime, respectively. The average ratios of OC/EC (day: 12.3; night: 9.3) and WSOC/OC (day: 0.74; night: 0.48) were relatively high during daytime (OC: organic carbon; EC: elemental carbon; WSOC: water-soluble organic carbon). Strong linear correlations (R 2 ≥0.6; p<0.05) of OC with levoglucosan and K + BB suggest biomass burning emission as predominant source of organic aerosols over the IGP. The measured concentrations of total DCA (ΣC 2 -C 10 ) showed pronounced diurnal variability with a higher concentration during nighttime (2510±1025ngm -3 ) as compared to that in daytime (1499±562ngm -3 ). Concentrations of oxalic acid (C 2 ), succinic acid (C 4 ) and malonic acid (C 3 ) were predominantly high as compared to other congeners of DCA (C 2 -C 10 ) over central IGP. Relatively higher mass fraction (73.4%) of C 2 in total DCA during nighttime than that in daytime (61.5%) indicates role of secondary organic aerosols (SOAs) formation involving aqueous-phase chemistry. Strong linear correlations of C 2 with C 3 and C 4 plausibly suggest that C 2 can have predominant formation pathways via decomposition of higher congeners of DCA. Overall, strong linear correlations of C 2 with levoglucosan and sulphate suggest that biomass burning emission and secondary transformations are predominant sources of DCA over IGP during wintertime. Copyright © 2017 Elsevier B.V. All rights reserved.
Patterns of vegetation and grasshopper community composition.
Kemp, W P; Harvey, S J; O'Neill, K M
1990-06-01
A study was conducted to evaluate differences in rangeland grasshopper communities over environmental gradients in Gallatin Valley, Montana, USA. The concept of habitat type (Daubenmire 1966) was used as a basis for discriminating between groupings of patches based on vegetation. A total of 39 patches were selected that represented five recognized grassland habitat types (Mueggler and Stewart 1980), as well as two disturbed types (replanting within a known habitat type). Repeated sampling in 1988 of both the insect and plant communities yielded a total of 40 grasshopper (19 664 individuals) and 97 plant species. Detrended Correspondence Analysis (DCA) indicated that patch classifications based on presence and percent cover of plants were appropriate and showed good between-group (habitat type) separation for patches along gradients of precipitation/elevation and plant community complexity. Results from undisturbed habitats showed that plant and grasshopper species composition changed over observed environmental gradients and suggested that habitat type influenced not only species presence, but also relative abundance. Discussion is presented that relates results with patch-use and core and satellite species paradigms.
Obaid, Ramiz; Abu-Qaoud, Hassan; Arafeh, Rami
2014-09-03
Eight accessions of olive trees from three common varieties in Palestine, Nabali Baladi, Nabali Mohassan and Surri, were genetically evaluated using five simple sequence repeat (SSR) markers. A total of 17 alleles from 5 loci were observed in which 15 (88.2%) were polymorphic and 2 (11.8%) were monomorphic. An average of 3.4 alleles per locus was found ranging from 2.0 alleles with the primers GAPU-103 and DCA-9 to 5.0 alleles with U9932 and DCA-16. The smallest amplicon size observed was 50 bp with the primer DCA-16, whereas the largest one (450 bp) with the primer U9932. Cluster analysis with the unweighted pair group method with arithmetic average (UPGMA) showed three clusters: a cluster with four accessions from the 'Nabali Baladi' cultivar, another cluster with three accessions that represents the 'Nabali Mohassen' cultivar and finally the 'Surri' cultivar. The similarity coefficient for the eight olive tree samples ranged from a maximum of 100% between two accessions from Nabali Baladi and also in two other samples from Nabali Mohassan, to a minimum similarity coefficient (0.315) between the Surri and two Nabali Baladi accessions. The results in this investigation clearly highlight the genetic dissimilarity between the three main olive cultivars that have been misidentified and mixed up in the past, based on conventional morphological characters.
USDA-ARS?s Scientific Manuscript database
Consumption of a high fat diet causes an increase in bile acid deoxycholic acid (DCA) in colon lumen and colon cancer risk while butyrate, an intestinal microbiota metabolite of dietary fiber, has been shown to exhibit colon cancer preventive effects. To distinguish these opposing effects of DCA and...
Dichloroacetate (DCA) is a rodent carcinogen commonly found in municipal drinking water supplies. Toxicokinetic studies have established that elimination of DCA is controlled by liver metabolism, which occurs by the cytosolic enzyme glutathione-S-transferase-zeta (GST-z...
Król, J. E.; Penrod, J. T.; McCaslin, H.; Rogers, L. M.; Yano, H.; Stancik, A. D.; Dejonghe, W.; Brown, C. J.; Parales, R. E.; Wuertz, S.
2012-01-01
Broad-host-range catabolic plasmids play an important role in bacterial degradation of man-made compounds. To gain insight into the role of these plasmids in chloroaniline degradation, we determined the first complete nucleotide sequences of an IncP-1 chloroaniline degradation plasmid, pWDL7::rfp and its close relative pNB8c, as well as the expression pattern, function, and bioaugmentation potential of the putative 3-chloroaniline (3-CA) oxidation genes. Based on phylogenetic analysis of backbone proteins, both plasmids are members of a distinct clade within the IncP-1β subgroup. The plasmids are almost identical, but whereas pWDL7::rfp carries a duplicate inverted catabolic transposon, Tn6063, containing a putative 3-CA oxidation gene cluster, dcaQTA1A2BR, pNB8c contains only a single copy of the transposon. No genes for an aromatic ring cleavage pathway were detected on either plasmid, suggesting that only the upper 3-CA degradation pathway was present. The dcaA1A2B gene products expressed from a high-copy-number vector were shown to convert 3-CA to 4-chlorocatechol in Escherichia coli. Slight differences in the dca promoter region between the plasmids and lack of induction of transcription of the pNB8c dca genes by 3-CA may explain previous findings that pNB8C does not confer 3-CA transformation. Bioaugmentation of activated sludge with pWDL7::rfp accelerated removal of 3-CA, but only in the presence of an additional carbon source. Successful bioaugmentation requires complementation of the upper pathway genes with chlorocatechol cleavage genes in indigenous bacteria. The genome sequences of these plasmids thus help explain the molecular basis of their catabolic activities. PMID:22101050
Dichloroacetate and cancer: new home for an orphan drug?
Kankotia, Shyam; Stacpoole, Peter W
2014-12-01
We reviewed the anti-cancer effects of DCA, an orphan drug long used as an investigational treatment for various acquired and congenital disorders of mitochondrial intermediary metabolism. Inhibition by DCA of mitochondrial pyruvate dehydrogenase kinases and subsequent reactivation of the pyruvate dehydrogenase complex and oxidative phosphorylation is the common mechanism accounting for the drug's anti-neoplastic effects. At least two fundamental changes in tumor metabolism are induced by DCA that antagonize tumor growth, metastases and survival: the first is the redirection of glucose metabolism from glycolysis to oxidation (reversal of the Warburg effect), leading to inhibition of proliferation and induction of caspase-mediated apoptosis. These effects have been replicated in both human cancer cell lines and in tumor implants of diverse germ line origin. The second fundamental change is the oxidative removal of lactate, via pyruvate, and the co-incident buffering of hydrogen ions by dehydrogenases located in the mitochondrial matrix. Preclinical studies demonstrate that DCA has additive or synergistic effects when used in combination with standard agents designed to modify tumor oxidative stress, vascular remodeling, DNA integrity or immunity. These findings and limited clinical results suggest that potentially fruitful areas for additional clinical trials include 1) adult and pediatric high grade astrocytomas; 2) BRAF-mutant cancers, such as melanoma, perhaps combined with other pro-oxidants; 3) tumors in which resistance to standard platinum-class drugs alone may be overcome with combination therapy; and 4) tumors of endodermal origin, in which extensive experimental research has demonstrated significant anti-proliferative, pro-apoptotic effects of DCA, leading to improved host survival. Copyright © 2014 Elsevier B.V. All rights reserved.
Aeolian dunes as ground truth for atmospheric modeling on Mars
Hayward, R.K.; Titus, T.N.; Michaels, T.I.; Fenton, L.K.; Colaprete, A.; Christensen, P.R.
2009-01-01
Martian aeolian dunes preserve a record of atmosphere/surface interaction on a variety of scales, serving as ground truth for both Global Climate Models (GCMs) and mesoscale climate models, such as the Mars Regional Atmospheric Modeling System (MRAMS). We hypothesize that the location of dune fields, expressed globally by geographic distribution and locally by dune centroid azimuth (DCA), may record the long-term integration of atmospheric activity across a broad area, preserving GCM-scale atmospheric trends. In contrast, individual dune morphology, as expressed in slipface orientation (SF), may be more sensitive to localized variations in circulation, preserving topographically controlled mesoscale trends. We test this hypothesis by comparing the geographic distribution, DCA, and SF of dunes with output from the Ames Mars GCM and, at a local study site, with output from MRAMS. When compared to the GCM: 1) dunes generally lie adjacent to areas with strongest winds, 2) DCA agrees fairly well with GCM modeled wind directions in smooth-floored craters, and 3) SF does not agree well with GCM modeled wind directions. When compared to MRAMS modeled winds at our study site: 1) DCA generally coincides with the part of the crater where modeled mean winds are weak, and 2) SFs are consistent with some weak, topographically influenced modeled winds. We conclude that: 1) geographic distribution may be valuable as ground truth for GCMs, 2) DCA may be useful as ground truth for both GCM and mesoscale models, and 3) SF may be useful as ground truth for mesoscale models. Copyright 2009 by the American Geophysical Union.
Rejali, Mehri; Mansourian, Marjan; Babaei, Zohre; Eshrati, Babak
2017-01-01
In this study, we evaluated assessed elements connected with low birth weight (LBW) and used decision curve analysis (DCA) to define a scale to anticipate the probability of having a LBW newborn child. This hospital-based case-control study was led in Arak Hospital in Iran. The study included 470 mothers with LBW neonate and 470 mothers with natural neonates. Information were gathered by meeting moms utilizing preplanned organized questionnaire and from hospital records. The estimated probabilities of detecting LBW were calculated using the logistic regression and DCA to quantify the clinical consequences and its validation. Factors significantly associated with LBW were premature membrane rupture (odds ratio [OR] = 3.18 [1.882-5.384]), former LBW infants (OR = 2.99 [1.510-5.932]), premature pain (OR = 2.70 [1.659-4.415]), hypertension in pregnancy (OR = 2.39 [1.429-4.019]), last trimester of pregnancy bleeding (OR = 2.58 [1.018-6.583]), mother age >30 (OR = 2.17 [1.350-3.498]). However, with DCA, the prediction model made on these 15 variables has a net benefit (NB) of 0.3110 is best predictive with the highest NB. NB has simple clinical interpretation and utilizing the model is what might as well be called a procedure that distinguished what might as well be called 31.1 LBW per 100 cases with no superfluous recognize. It is conceivable to foresee LBW utilizing a prediction model show in light of noteworthy hazard components connected with LBW. The majority of the hazard elements for LBW are preventable, and moms can be alluded amid early pregnancy to a middle which is furnished with facilities for administration of high hazard pregnancy and LBW infant.
Yang, Weili; Pollard, Mike; Li-Beisson, Yonghua; Ohlrogge, John
2016-10-01
Cutin is an extracellular lipid polymer that contributes to protective cuticle barrier functions against biotic and abiotic stresses in land plants. Glycerol has been reported as a component of cutin, contributing up to 14% by weight of total released monomers. Previous studies using partial hydrolysis of cuticle-enriched preparations established the presence of oligomers with glycerol-aliphatic ester links. Furthermore, glycerol-3-phosphate 2-O-acyltransferases (sn-2-GPATs) are essential for cutin biosynthesis. However, precise roles of glycerol in cutin assembly and structure remain uncertain. Here, a stable isotope-dilution assay was developed for the quantitative analysis of glycerol by GC/MS of triacetin with simultaneous determination of aliphatic monomers. To provide clues about the role of glycerol in dicarboxylic acid (DCA)-rich cutins, this methodology was applied to compare wild-type (WT) Arabidopsis cutin with a series of mutants that are defective in cutin synthesis. The molar ratio of glycerol to total DCAs in WT cutins was 2:1. Even when allowing for a small additional contribution from hydroxy fatty acids, this is a substantially higher glycerol to aliphatic monomer ratio than previously reported for any cutin. Glycerol content was strongly reduced in both stem and leaf cutin from all Arabidopsis mutants analyzed (gpat4/gpat8, att1-2 and lacs2-3). In addition, the molar reduction of glycerol was proportional to the molar reduction of total DCAs. These results suggest "glycerol-DCA-glycerol" may be the dominant motif in DCA-rich cutins. The ramifications and caveats for this hypothesis are presented. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Rejali, Mehri; Mansourian, Marjan; Babaei, Zohre; Eshrati, Babak
2017-01-01
Background: In this study, we evaluated assessed elements connected with low birth weight (LBW) and used decision curve analysis (DCA) to define a scale to anticipate the probability of having a LBW newborn child. Methods: This hospital-based case–control study was led in Arak Hospital in Iran. The study included 470 mothers with LBW neonate and 470 mothers with natural neonates. Information were gathered by meeting moms utilizing preplanned organized questionnaire and from hospital records. The estimated probabilities of detecting LBW were calculated using the logistic regression and DCA to quantify the clinical consequences and its validation. Results: Factors significantly associated with LBW were premature membrane rupture (odds ratio [OR] = 3.18 [1.882–5.384]), former LBW infants (OR = 2.99 [1.510–5.932]), premature pain (OR = 2.70 [1.659–4.415]), hypertension in pregnancy (OR = 2.39 [1.429–4.019]), last trimester of pregnancy bleeding (OR = 2.58 [1.018–6.583]), mother age >30 (OR = 2.17 [1.350–3.498]). However, with DCA, the prediction model made on these 15 variables has a net benefit (NB) of 0.3110 is best predictive with the highest NB. NB has simple clinical interpretation and utilizing the model is what might as well be called a procedure that distinguished what might as well be called 31.1 LBW per 100 cases with no superfluous recognize. Conclusions: It is conceivable to foresee LBW utilizing a prediction model show in light of noteworthy hazard components connected with LBW. The majority of the hazard elements for LBW are preventable, and moms can be alluded amid early pregnancy to a middle which is furnished with facilities for administration of high hazard pregnancy and LBW infant. PMID:28928911
Tetra-ethyl lead was widely used in leaded automobile gasoline from 1923 until 1987. To prevent lead deposits from fouling the engine, 1,2-dibromoethane (EDB) and 1,2-dichloroethane (1,2-DCA) were added to the gasoline to act as lead scavengers. If leaded gasoline is spilled to...
A key question in the risk assessment of trichloroethylene (TRI) is the extent to which its carcinogenic effects might depend on the formation of dichloroacetate (DCA) as a metabolite. One of the metabolic pathways proposed for the formation of DCA from TRI is by the reductive...
Dillehay, Jacob L; Bowman, Kimberly S; Yan, Jun; Rainey, Fred A; Moe, William M
2014-04-01
When chlorinated alkanes are present as soil or groundwater pollutants, they often occur in mixtures. This study evaluated substrate interactions during the anaerobic reductive dehalogenation of chlorinated alkanes by the type strains of two Dehalogenimonas species, D. lykanthroporepellens and D. alkenigignens. Four contaminant mixtures comprised of combinations of the chlorinated solvents 1,2-dichloroethane (1,2-DCA), 1,2-dichloropropane (1,2-DCP), and 1,1,2-trichloroethane (1,1,2-TCA) were assessed for each species. Chlorinated solvent depletion and daughter product formation determined as a function of time following inoculation into anaerobic media revealed preferential dechlorination of 1,1,2-TCA over both 1,2-DCA and 1,2-DCP for both species. 1,2-DCA in particular was not dechlorinated until 1,1,2-TCA reached low concentrations. In contrast, both species concurrently dechlorinated 1,2-DCA and 1,2-DCP over a comparably large concentration range. This is the first report of substrate interactions during chlorinated alkane dehalogenation by pure cultures, and the results provide insights into the chlorinated alkane transformation processes that may be expected for contaminant mixtures in environments where Dehalogenimonas spp. are present.
Tsalatsanis, Athanasios; Barnes, Laura E; Hozo, Iztok; Djulbegovic, Benjamin
2011-12-23
Despite the well documented advantages of hospice care, most terminally ill patients do not reap the maximum benefit from hospice services, with the majority of them receiving hospice care either prematurely or delayed. Decision systems to improve the hospice referral process are sorely needed. We present a novel theoretical framework that is based on well-established methodologies of prognostication and decision analysis to assist with the hospice referral process for terminally ill patients. We linked the SUPPORT statistical model, widely regarded as one of the most accurate models for prognostication of terminally ill patients, with the recently developed regret based decision curve analysis (regret DCA). We extend the regret DCA methodology to consider harms associated with the prognostication test as well as harms and effects of the management strategies. In order to enable patients and physicians in making these complex decisions in real-time, we developed an easily accessible web-based decision support system available at the point of care. The web-based decision support system facilitates the hospice referral process in three steps. First, the patient or surrogate is interviewed to elicit his/her personal preferences regarding the continuation of life-sustaining treatment vs. palliative care. Then, regret DCA is employed to identify the best strategy for the particular patient in terms of threshold probability at which he/she is indifferent between continuation of treatment and of hospice referral. Finally, if necessary, the probabilities of survival and death for the particular patient are computed based on the SUPPORT prognostication model and contrasted with the patient's threshold probability. The web-based design of the CDSS enables patients, physicians, and family members to participate in the decision process from anywhere internet access is available. We present a theoretical framework to facilitate the hospice referral process. Further rigorous clinical evaluation including testing in a prospective randomized controlled trial is required and planned.
2011-01-01
Background Despite the well documented advantages of hospice care, most terminally ill patients do not reap the maximum benefit from hospice services, with the majority of them receiving hospice care either prematurely or delayed. Decision systems to improve the hospice referral process are sorely needed. Methods We present a novel theoretical framework that is based on well-established methodologies of prognostication and decision analysis to assist with the hospice referral process for terminally ill patients. We linked the SUPPORT statistical model, widely regarded as one of the most accurate models for prognostication of terminally ill patients, with the recently developed regret based decision curve analysis (regret DCA). We extend the regret DCA methodology to consider harms associated with the prognostication test as well as harms and effects of the management strategies. In order to enable patients and physicians in making these complex decisions in real-time, we developed an easily accessible web-based decision support system available at the point of care. Results The web-based decision support system facilitates the hospice referral process in three steps. First, the patient or surrogate is interviewed to elicit his/her personal preferences regarding the continuation of life-sustaining treatment vs. palliative care. Then, regret DCA is employed to identify the best strategy for the particular patient in terms of threshold probability at which he/she is indifferent between continuation of treatment and of hospice referral. Finally, if necessary, the probabilities of survival and death for the particular patient are computed based on the SUPPORT prognostication model and contrasted with the patient's threshold probability. The web-based design of the CDSS enables patients, physicians, and family members to participate in the decision process from anywhere internet access is available. Conclusions We present a theoretical framework to facilitate the hospice referral process. Further rigorous clinical evaluation including testing in a prospective randomized controlled trial is required and planned. PMID:22196308
The lead scavengers 1,2-dibromoethane (EDB) and 1,2-dichloroethane (1,2-DCA) were included along with lead in conventional leaded gasoline used for automobiles in the US prior to 1988. Old spills of leaded gasoline from underground storage tank systems (USTs) at gasoline service...
h2>Abstract
Dichloroacetate (DCA) and trichloroacetate (TCA) are prominent by-products of chlorination of drinking water. Both chemicals have been shown to be hepatic carcinogens in mice. Prior work has demonstrated that DCA inhibits its own metabolism in rats and humans. ...
Omoruyi, Felix O; Mustafa, Gul M; Okorodudu, Anthony O; Petersen, John R
2012-03-22
The evaluation of microalbumin, creatinine and albumin-creatinine ratio is very important in patients with diabetes for the early detection of kidney disease and the identification of patients at risk for complications from diabetes or hypertension. A total of 88 spot urine samples previously analyzed using the Vitros 5,1 FS (creatinine) and Beckman Coulter Immage (microalbumin) located in the central laboratory and having microalbumin and creatinine values within the Afinion and DCA Vantage reportable ranges were run on 2 point of care (POC) instruments (Siemens DCA Vantage and Axis-Shield Afinion). The mean values for the DCA Vantage were: 42.6 mg/l for albumin, 10.3 mol/l for creatinine, and 5.4 mg/mol for ACR. For the Afinion AS100, the mean values were: 48.5mg/l for albumin, 9.5 mol/l for creatinine, and 6.7 mg/mol for ACR. The mean values obtained for CL were: 40.8 mg/l for albumin, 10.0 mol/l for creatinine, and 5.4 mg/mol for ACR. All POC analyzers showed good correlation to the central laboratory tests for microalbumin, creatinine and albumin creatinine ratio (ACR) for Afinion (R(2)=0.954, 0.974, and 0.964, respectively) and DCA Vantage (R(2)=0.989, 0.987, and 0.991, respectively). With the exception of the DCA Vantage ACR (p=0.53), the levels of microalbumin, creatinine and ACR obtained for the Afinion and DCA Vantage instruments as compared to the CL were statistically different (p<0.05). The inter and intraday imprecision for both POC instruments was <2.9% and total imprecision <8.7%. The 2 instruments evaluated in this study were in good agreement with the quantitative laboratory results and thus can be used for microalbumin, creatinine and ACR assays at the POC. However, facilities using Afinion will have to use different normal range for ACR. Copyright © 2011 Elsevier B.V. All rights reserved.
Mroz, Magdalena S; Lajczak, Natalia K; Goggins, Bridie J; Keely, Simon; Keely, Stephen J
2018-03-01
The intestinal epithelium constitutes an innate barrier which, upon injury, undergoes self-repair processes known as restitution. Although bile acids are known as important regulators of epithelial function in health and disease, their effects on wound healing processes are not yet clear. Here we set out to investigate the effects of the colonic bile acids, deoxycholic acid (DCA) and ursodeoxycholic acid (UDCA), on epithelial restitution. Wound healing in T 84 cell monolayers grown on transparent, permeable supports was assessed over 48 h with or without bile acids. Cell migration was measured in Boyden chambers. mRNA and protein expression were measured by RT-PCR and Western blotting. DCA (50-150 µM) significantly inhibited wound closure in cultured epithelial monolayers and attenuated cell migration in Boyden chamber assays. DCA also induced nuclear accumulation of the farnesoid X receptor (FXR), whereas an FXR agonist, GW4064 (10 µM), inhibited wound closure. Both DCA and GW4064 attenuated the expression of CFTR Cl - channels, whereas inhibition of CFTR activity with either CFTR- inh -172 (10 µM) or GlyH-101 (25 µM) also prevented wound healing. Promoter/reporter assays revealed that FXR-induced downregulation of CFTR is mediated at the transcriptional level. In contrast, UDCA (50-150 µM) enhanced wound healing in vitro and prevented the effects of DCA. Finally, DCA inhibited and UDCA promoted mucosal healing in an in vivo mouse model. In conclusion, these studies suggest bile acids are important regulators of epithelial wound healing and are therefore good targets for development of new drugs to modulate intestinal barrier function in disease treatment. NEW & NOTEWORTHY The secondary bile acid, deoxycholic acid, inhibits colonic epithelial wound healing, an effect which appears to be mediated by activation of the nuclear bile acid receptor, FXR, with subsequent downregulation of CFTR expression and activity. In contrast, ursodeoxycholic acid promotes wound healing, suggesting it may provide an alternative approach to prevent the losses of barrier function that are associated with mucosal inflammation in IBD patients.
Obaid, Ramiz; Abu-Qaoud, Hassan; Arafeh, Rami
2014-01-01
Eight accessions of olive trees from three common varieties in Palestine, Nabali Baladi, Nabali Mohassan and Surri, were genetically evaluated using five simple sequence repeat (SSR) markers. A total of 17 alleles from 5 loci were observed in which 15 (88.2%) were polymorphic and 2 (11.8%) were monomorphic. An average of 3.4 alleles per locus was found ranging from 2.0 alleles with the primers GAPU-103 and DCA-9 to 5.0 alleles with U9932 and DCA-16. The smallest amplicon size observed was 50 bp with the primer DCA-16, whereas the largest one (450 bp) with the primer U9932. Cluster analysis with the unweighted pair group method with arithmetic average (UPGMA) showed three clusters: a cluster with four accessions from the ‘Nabali Baladi’ cultivar, another cluster with three accessions that represents the ‘Nabali Mohassen’ cultivar and finally the ‘Surri’ cultivar. The similarity coefficient for the eight olive tree samples ranged from a maximum of 100% between two accessions from Nabali Baladi and also in two other samples from Nabali Mohassan, to a minimum similarity coefficient (0.315) between the Surri and two Nabali Baladi accessions. The results in this investigation clearly highlight the genetic dissimilarity between the three main olive cultivars that have been misidentified and mixed up in the past, based on conventional morphological characters. PMID:26019564
Sun, Lue; Moritake, Takashi; Ito, Kazuya; Matsumoto, Yoshitaka; Yasui, Hironobu; Nakagawa, Hidehiko; Hirayama, Aki; Inanami, Osamu; Tsuboi, Koji
2017-01-01
Medulloblastoma is a fatal brain tumor in children, primarily due to the presence of treatment-resistant medulloblastoma stem cells. The energy metabolic pathway is a potential target of cancer therapy because it is often different between cancer cells and normal cells. However, the metabolic properties of medulloblastoma stem cells, and whether specific metabolic pathways are essential for sustaining their stem cell-like phenotype and radioresistance, remain unclear. We have established radioresistant medulloblastoma stem-like clones (rMSLCs) by irradiation of the human medulloblastoma cell line ONS-76. Here, we assessed reactive oxygen species (ROS) production, mitochondria function, oxygen consumption rate (OCR), energy state, and metabolites of glycolysis and tricarboxylic acid cycle in rMSLCs and parental cells. rMSLCs showed higher lactate production and lower oxygen consumption rate than parental cells. Additionally, rMSLCs had low mitochondria mass, low endogenous ROS production, and existed in a low-energy state. Treatment with the metabolic modifier dichloroacetate (DCA) resulted in mitochondria dysfunction, glycolysis inhibition, elongated mitochondria morphology, and increased ROS production. DCA also increased radiosensitivity by suppression of the DNA repair capacity through nuclear oxidization and accelerated the generation of acetyl CoA to compensate for the lack of ATP. Moreover, treatment with DCA decreased cancer stem cell-like characters (e.g., CD133 positivity and sphere-forming ability) in rMSLCs. Together, our findings provide insights into the specific metabolism of rMSLCs and illuminate potential metabolic targets that might be exploited for therapeutic benefit in medulloblastoma.
Sun, Lue; Moritake, Takashi; Ito, Kazuya; Matsumoto, Yoshitaka; Yasui, Hironobu; Nakagawa, Hidehiko; Hirayama, Aki; Inanami, Osamu; Tsuboi, Koji
2017-01-01
Medulloblastoma is a fatal brain tumor in children, primarily due to the presence of treatment-resistant medulloblastoma stem cells. The energy metabolic pathway is a potential target of cancer therapy because it is often different between cancer cells and normal cells. However, the metabolic properties of medulloblastoma stem cells, and whether specific metabolic pathways are essential for sustaining their stem cell-like phenotype and radioresistance, remain unclear. We have established radioresistant medulloblastoma stem-like clones (rMSLCs) by irradiation of the human medulloblastoma cell line ONS-76. Here, we assessed reactive oxygen species (ROS) production, mitochondria function, oxygen consumption rate (OCR), energy state, and metabolites of glycolysis and tricarboxylic acid cycle in rMSLCs and parental cells. rMSLCs showed higher lactate production and lower oxygen consumption rate than parental cells. Additionally, rMSLCs had low mitochondria mass, low endogenous ROS production, and existed in a low-energy state. Treatment with the metabolic modifier dichloroacetate (DCA) resulted in mitochondria dysfunction, glycolysis inhibition, elongated mitochondria morphology, and increased ROS production. DCA also increased radiosensitivity by suppression of the DNA repair capacity through nuclear oxidization and accelerated the generation of acetyl CoA to compensate for the lack of ATP. Moreover, treatment with DCA decreased cancer stem cell-like characters (e.g., CD133 positivity and sphere-forming ability) in rMSLCs. Together, our findings provide insights into the specific metabolism of rMSLCs and illuminate potential metabolic targets that might be exploited for therapeutic benefit in medulloblastoma. PMID:28426747
Krivec, M; Dillert, R; Bahnemann, D W; Mehle, A; Štrancar, J; Dražić, G
2014-07-28
Photocatalytic degradation of dichloroacetic acid (DCA) was studied in a continuous-flow set-up using a titanium microreactor with an immobilized double-layered TiO2 nanoparticle/nanotube film. Chloride ions, formed during the degradation process, negatively affect the photocatalytic efficiency and at a certain concentration (approximately 0.5 mM) completely stop the reaction in the microreactor. Two proposed mechanisms of inhibition with chloride ions, competitive adsorption and photogenerated-hole scavenging, have been proposed and investigated by adsorption isotherms and electron paramagnetic resonance (EPR) measurements. The results show that chloride ions block the DCA adsorption sites on the titania surface and reduce the amount of adsorbed DCA molecules. The scavenging effect of chloride ions during photocatalysis through the formation of chlorine radicals was not detected.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-15
... to an extratropical storm that caused widespread power outages, severe flooding, and severe... storm. FAA Analysis Under the FAA's High Density Rule at DCA and Orders limiting operations at LGA, JFK... area or northeastern U.S. affected by the storm. These circumstances may have created a unique hardship...
Characterization of the interface between cellulosic fibers and a thermoplastic matrix
Feipeng P. Liu; Michael P. Wolcott; Douglas J. Gardner; Timothy G. Rials
1994-01-01
The applicability of the microbond test to evaluate the interfacial properties between cellulosic fibers and thermoplastics was studied. Acetylation and beat treatment were applied to modify the surface of cellulosic fibers (rayon, cotton, and wood). The apparent diameters and surface free energies of the fibers were estimated by dynamic contact angle (DCA) analysis....
ABSTRACT
Dichloroacetic acid (DCA) is carcinogenic to the B6C3F 1 mouse and the F344 rat. Given the carcinogenic potential of DCA in rodent liver, and the known concentrations of this compound in drinking water, reliable biologically-based models to reduce the uncertai...
Pan, Yao; Wei, Xuetao; Hao, Weidong
2015-08-28
Trichloroethylene (TCE) is an occupational and ubiquitous environmental contaminant, and TCE exposure will increase the risk of autoimmune diseases and allergic diseases. T cells play an important role in the pathogenesis of TCE-related immune disorders, but the effect of TCE and its oxidative metabolites, trichloroacetic acid (TCA) and dichloroacetic acid (DCA), on the activation of human T cells is still unknown. In this study, Jurkat cells were pre-treated with TCE, TCA and DCA overnight and then stimulated with phorbol 12-myristate 13-acetate and ionomycin for another 4, 8 and 24 hours. IL-2 secretion was detected by ELISA; the expressions of CD25 and CD69 were tested by flow cytometry; and IFN-γ and IL-2 mRNA expression levels were investigated by real-time PCR. The results showed that TCE and its oxidative metabolites, TCA and DCA, significantly enhanced IL-2 releasing and the expression of T cell activation markers, CD25 and CD69. Consistent with this result, these compounds markedly up-regulated the expression levels of IFN-γ and IL-2 mRNA. Collectively, these findings suggest that TCE and its metabolites, TCA and DCA, might enhance the activation of T cells and disrupt various activities of peripheral T cells.
Pan, Yao; Wei, Xuetao; Hao, Weidong
2015-01-01
Trichloroethylene (TCE) is an occupational and ubiquitous environmental contaminant, and TCE exposure will increase the risk of autoimmune diseases and allergic diseases. T cells play an important role in the pathogenesis of TCE-related immune disorders, but the effect of TCE and its oxidative metabolites, trichloroacetic acid (TCA) and dichloroacetic acid (DCA), on the activation of human T cells is still unknown. In this study, Jurkat cells were pre-treated with TCE, TCA and DCA overnight and then stimulated with phorbol 12-myristate 13-acetate and ionomycin for another 4, 8 and 24 hours. IL-2 secretion was detected by ELISA; the expressions of CD25 and CD69 were tested by flow cytometry; and IFN-γ and IL-2 mRNA expression levels were investigated by real-time PCR. The results showed that TCE and its oxidative metabolites, TCA and DCA, significantly enhanced IL-2 releasing and the expression of T cell activation markers, CD25 and CD69. Consistent with this result, these compounds markedly up-regulated the expression levels of IFN-γ and IL-2 mRNA. Collectively, these findings suggest that TCE and its metabolites, TCA and DCA, might enhance the activation of T cells and disrupt various activities of peripheral T cells. PMID:26343699
Structure of a Spumaretrovirus Gag Central Domain Reveals an Ancient Retroviral Capsid
Dutta, Moumita; Pollard, Dominic J.; Goldstone, David C.; Ramos, Andres; Müllers, Erik; Stirnnagel, Kristin; Stanke, Nicole; Lindemann, Dirk; Taylor, William R.; Rosenthal, Peter B.
2016-01-01
The Spumaretrovirinae, or foamy viruses (FVs) are complex retroviruses that infect many species of monkey and ape. Despite little sequence homology, FV and orthoretroviral Gag proteins perform equivalent functions, including genome packaging, virion assembly, trafficking and membrane targeting. However, there is a paucity of structural information for FVs and it is unclear how disparate FV and orthoretroviral Gag molecules share the same function. To probe the functional overlap of FV and orthoretroviral Gag we have determined the structure of a central region of Gag from the Prototype FV (PFV). The structure comprises two all α-helical domains NtDCEN and CtDCEN that although they have no sequence similarity, we show they share the same core fold as the N- (NtDCA) and C-terminal domains (CtDCA) of archetypal orthoretroviral capsid protein (CA). Moreover, structural comparisons with orthoretroviral CA align PFV NtDCEN and CtDCEN with NtDCA and CtDCA respectively. Further in vitro and functional virological assays reveal that residues making inter-domain NtDCEN—CtDCEN interactions are required for PFV capsid assembly and that intact capsid is required for PFV reverse transcription. These data provide the first information that relates the Gag proteins of Spuma and Orthoretrovirinae and suggests a common ancestor for both lineages containing an ancient CA fold. PMID:27829070
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sirkar, Kamalesh; Jie, Xingming; Chau, John
Using the ionic liquid (IL) 1-butyl-3-methylimidazolium dicyanamide ([bmim][DCA]) as the absorbent on the shell side of a membrane module containing either a porous hydrophobized ceramic tubule or porous hydrophobized polyether ether ketone (PEEK) hollow fiber membranes, studies for CO{sub 2} removal from hot simulated pre-combustion shifted syngas were carried out by a novel pressure swing membrane absorption (PSMAB) process. Helium was used as a surrogate for H{sub 2} in a simulated shifted syngas with CO{sub 2} around 40% (dry gas basis). In this cyclic separation process, the membrane module was used to achieve non-dispersive gas absorption from a high-pressure feedmore » gas (689-1724 kPag; 100-250 psig) at temperatures between 25-1000C into a stationary absorbent liquid on the module shell side during a certain part of the cycle followed by among other cycle steps controlled desorption of the absorbed gases from the liquid in the rest of the cycle. Two product streams were obtained, one He-rich and the other CO{sub 2}-rich. Addition of polyamidoamine (PAMAM) dendrimer of generation 0 to IL [bmim][DCA] improved the system performance at higher temperatures. The solubilities of CO{sub 2} and He were determined in the ionic liquid with or without the dendrimer in solution as well as in the presence or absence of moisture; polyethylene glycol (PEG) 400 was also studied as a replacement for the IL. The solubility selectivity of the ionic liquid containing the dendrimer for CO{sub 2} over helium was considerably larger than that for the pure ionic liquid. The solubility of CO{sub 2} and CO{sub 2}-He solubility selectivity of PEG 400 and a solution of the dendrimer in PEG 400 were higher than the corresponding ones in the IL, [bmim][DCA]. A mathematical model was developed to describe the PSMAB process; a numerical solution of the governing equations described successfully the observed performance of the PSMAB process for the pure ionic liquid-based system.« less
Tetra-ethyl lead was widely used in leaded automobile gasoline from 1923 until 1987 (See Figure 1). To prevent lead deposits from fouling the engine, 1,2-dibromoethane (EDB) and 1,2-dichloroethane (1,2-DCA) were added to the gasoline to act as lead scavengers. These compounds r...
2010-10-01
Mathematics , Indiana University Northwest, Gary, IN 3Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, NY 4H...however, is mathematically more parsimonious. The original DCA formulation required several mathematical manipulations making the simplicity of regret...into treatment administration examples; IH developed the mathematical formulation of the model; AV is the author of DCA; BD proposed the regret theory
STUDIES ON RENAL JUXTAGLOMERULAR CELLS
Hartroft, Phyllis Merritt; Hartroft, W. Stanley
1953-01-01
Accumulation of granules in the juxtaglomerular cells occurred in rats which were maintained for 5 to 6 weeks on a diet low in sodium, chloride. Cytological evidence suggests that this was probably a storage phase of secretion following a decrease in the rate of liberation of the granules. Administration of DCA (desoxycorticosterone acetate) to salt-deficient rats did not alter this appearance of the juxtaglomerular cells. Two per cent sodium chloride taken in the drinking water consumed for 4 weeks by similar animals caused degranulation of the juxtaglomerular cells. This effect was enhanced by DCA. DCA administered to animals on a normal salt intake produced a lesser degree of degranulation. Cytological changes in degranulated cells suggested that these represent a stage of hyperactivity in the secretory cycle produced by an increase in the rate of liberation of granules. A hypothesis is suggested that the juxtaglomerular cells are involved in the hormonal regulation of sodium metabolism and/or blood pressure. PMID:13052809
Contamination of mercury in tongkat Ali hitam herbal preparations.
Ang, H H; Lee, K L
2006-08-01
The DCA (Drug Control Authority), Malaysia has implemented the phase three registration of traditional medicines on 1 January 1992. As such, a total of 100 products in various pharmaceutical dosage forms of a herbal preparation found in Malaysia, containing tongkat Ali hitam, either single or combined preparations, were analyzed for the presence of a heavy toxic metal, mercury, using atomic absorption spectrophotometer, after performing a simple random sampling to enable each sample an equal chance of being selected in an unbiased manner. Results showed that 26% of these products possessed 0.53-2.35 ppm of mercury, and therefore, do not comply with the quality requirement for traditional medicines in Malaysia. The quality requirement for traditional medicines in Malaysia is not exceeding 0.5 ppm for mercury. Out of these 26 products, four products have already registered with the DCA, Malaysia whilst the rest, however, have not registered with the DCA, Malaysia.
Effect of Boron Clusters on the Ignition Reaction of HNO3 and Dicynanamide-Based Ionic Liquids.
Schmidt, Michael W; Gordon, Mark S
2017-10-19
Many ionic liquids containing the dicynamide anion (DCA - , formula N(CN) 2 - ) exhibit hypergolic ignition when exposed to the common oxidizer nitric acid. However, the ignition delay is often about 10 times longer than the desired 5 ms for rocket applications, so that improvements are desired. Experiments in the past decade have suggested both a mechanism for the early reaction steps and also that additives such as decaborane can reduce the ignition delay. The mechanisms for reactions of nitric acid with both DCA - and protonated DCAH are considered here, using accurate wave function methods. Complexation of DCA - or DCAH with borane clusters B 10 H 14 or B 9 H 14 - is found to modify these mechanisms slightly by changing the nature of some of the intermediate saddle points and by small reductions in the reaction barriers.
Timmons, James A; Constantin-Teodosiu, Dumitru; Poucher, Simon M; Greenhaff, Paul L
2004-01-01
We previously established that activation of the pyruvate dehydrogenase complex (PDC) using dichloroacetate (DCA) reduced the reliance on substrate-level phosphorylation (SLP) at the onset of exercise, with normal and reduced blood flow. PDC activation also reduced fatigue development during contraction with reduced blood flow. Since these observations, several studies have re-evaluated our observations. One study demonstrated a performance benefit without a reduction in SLP, raising a question mark over PDC's role in the regulation of ATP regeneration and our interpretation of fatigue mechanisms. Using a model of muscle contraction similar to the conflicting study (i.e. tetanic rather than twitch stimulation), we re-examined this question. Using canine skeletal muscle, one group was infused with saline while the other was pretreated with 300 mg (kg body mass)−1 DCA. Muscle biopsies were taken at rest, peak tension (1 min) and after 6 min of tetanic electrical stimulation (75 ms on−925 ms off per second) and blood flow was limited to 25% of normal values observed during contraction. DCA reduced phosphocreatine (PCr) degradation by 40% during the first minute of contraction, but did not prevent the almost complete depletion of PCr stores at 6 min, while muscle fatigue did not differ between the two groups. During intermittent tetanic stimulation PCr degradation was 75% greater than with our previous 3 Hz twitch contraction protocol, despite a similar rate of oxygen consumption at 6 min. Thus, in the present study enhanced acetyl group availability altered the time course of PCr utilization but did not prevent the decline towards depletion. Consistent with our earlier conclusions, DCA pretreatment reduces muscle fatigue only when SLP is attenuated. The present study and our met-analysis indicates that enhanced acetyl group availability results in a readily measurable reduction in SLP when the initial rate of PCr utilization is ∼1 mmol (kg dry mass)−1 s−1 or less (depending on intrinsic mitochondrial capacity). When measured early during an uninterrupted period of muscle contraction, acetyl group availability is likely to influence SLP under any condition where mitochondria are responsible for a significant proportion of ATP regeneration. PMID:15498812
Prach, Karel; Lencová, Kamila; Rehounková, Klára; Dvořáková, Helena; Jírová, Alena; Konvalinková, Petra; Mudrák, Ondřej; Novák, Jan; Trnková, Romana
2013-11-01
We performed detrended correspondence analysis (DCA) ordination to compare seven successional seres running in stone quarries, coal mining spoil heaps, sand and gravel pits, and extracted peatlands in the Czech Republic in central Europe. In total, we obtained 1,187 vegetation samples containing 705 species. These represent various successional stages aged from 1 to 100 years. The successional seres studied were more similar in their species composition in the initial stages, in which synathropic species prevailed, than in later successional stages. This vegetation differentiation was determined especially by local moisture conditions. In most cases, succession led to a woodland, which usually established after approximately 20 years. In very dry or wet places, by contrast, where woody species were limited, often highly valuable, open vegetation developed. Except in the peatlands, the total number of species and the number of target species increased during succession. Participation of invasive aliens was mostly unimportant. Spontaneous vegetation succession generally appears to be an ecologically suitable and cheap way of ecosystem restoration of heavily disturbed sites. It should, therefore, be preferred over technical reclamation.
Building toy models of proteins using coevolutionary information
NASA Astrophysics Data System (ADS)
Cheng, Ryan; Raghunathan, Mohit; Onuchic, Jose
2015-03-01
Recent developments in global statistical methodologies have advanced the analysis of large collections of protein sequences for coevolutionary information. Coevolution between amino acids in a protein arises from compensatory mutations that are needed to maintain the stability or function of a protein over the course of evolution. This gives rise to quantifiable correlations between amino acid positions within the multiple sequence alignment of a protein family. Here, we use Direct Coupling Analysis (DCA) to infer a Potts model Hamiltonian governing the correlated mutations in a protein family to obtain the sequence-dependent interaction energies of a toy protein model. We demonstrate that this methodology predicts residue-residue interaction energies that are consistent with experimental mutational changes in protein stabilities as well as other computational methodologies. Furthermore, we demonstrate with several examples that DCA could be used to construct a structure-based model that quantitatively agrees with experimental data on folding mechanisms. This work serves as a potential framework for generating models of proteins that are enriched by evolutionary data that can potentially be used to engineer key functional motions and interactions in protein systems. This research has been supported by the NSF INSPIRE award MCB-1241332 and by the CTBP sponsored by the NSF (Grant PHY-1427654).
MECHANISMS INVOLVED IN TRICHLOROETHYLENE INDUCED LIVER CANCER: IMPORTANCE TO ENVIRONMENTAL CLEANUP
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bull, Richard J.; Thrall, Brain D.
2001-12-31
Trichloroethylene (TCE) is a common contaminant of groundwater as a result of poor disposal practices of the past. As a consequence, this solvent is the focus of many clean-up operations of uncontrolled hazardous waste sites. TCE is carcinogenic in both mice and rats, but at different sites, the liver and kidney, respectively (NCI 1976; NTP 1988; NTP 1990). Liver tumor induction in mice has been the tumor most critical from the standpoint of environmental regulation (Bull 2000). Under the proposed cancer risk guidelines of the Environmental Protection Agency (EPA 1996), identifying the dose-response behavior of key events involved in carcinogenicmore » responses can be used for developing alternative risk assessments. A major difficulty in developing alternative approaches for TCE is the fact that three of its metabolites are capable of inducing liver cancer in mice (Bull et al. 1990; Daniel et al. 1992; DeAngelo et al. 1999; Pereria 1996). Two of these metabolites have distinct modes of action, dichloroacetate (DCA) and trichloroacetate (TCA). The third metabolite, chloral hydrate, is probably active as a result of its conversion to one or both of these two metabolites. Ordinarily, the first approach to assigning causality to a metabolite in tumorigenesis would be an attempt to measure its concentration in the body and associate that with tumorigenic concentrations observed when the compound is itself administered. This can be done with relative ease with TCA. However, it has been more difficult with DCA since blood levels of this metabolite after exposure to carcinogenic doses of DCA fall rapidly below detection limits (Kato-Weinstein et al. 1998; Merdink et al. 1998). Mutations in the ras protooncogene have been used to determine if distinct patterns of DNAsequence alterations can provide indications of the type of DNA damage that might be produced by carcinogens. The presence of ras mutations in chemically-induced tumors was suggested as a means o f determining whether a chemical was genotoxic (Wiseman et al. 1986). However, the 7 discovery that spontaneous tumors also contain this oncogene indicated that this assumption may not be correct (Fox and Watanabe 1985). Several non-genotoxic carcinogens have been shown to produce tumors with a H-ras mutation frequency considerably below those that result spontaneously (Maronpot et al. 1995). Among these chemicals are a class called peroxisome proliferators, of which TCA and TCE are members. DCA and TCE were found to induce tumors with similar H-ras mutation spectra (Anna et al. 1994), whereas only limited data have been available on TCA (Fereira-Gonzalez et al. 1995). Thus, a major focus of this research was to evaluate whether the pattern and frequency of H-ras mutations in TCE-induced tumors could be explained by the same parameters in tumors induced by the metabolites TCA or DCA. The present project was organized around three interrelated objectives: The first objective addressed the pharmacokinetic questions regarding the formation and elimination of DCA and TCA in mice administered TCE and whether levels of these metabolites may account for the tumors induced by TCE. The second objective was to investigate potential molecular mechanisms by which TCA and DCA may, in the absence of directly causing mutations, promote the clonal growth and expansion of precancerous cell populations within mouse liver. The third objective was to investigate whether the genotype of tumors induced by TCA and DCA can be used to establish the relative roles of these metabolites in TCE-induced cancer. In particular, the focus of the latter studies was to compare the incidence and spectra of mutations in the H-ras gene (codon 61) to determine if the reported similarities in the genotype of DCA- and TCE-induced tumors have a causal relationship.« less
Defense Communications Agency Cost and Planning Factors Manual. Change 1.
1984-06-11
shows the total costs for placing payloads in orbit. This includes reimbursement to NASA for Shuttle services, purchase of the upper stage, and upper...23-6 DCAC 600-60-1 SECTION D Change I ’" = TABLE 23-2. DCA MILITARY LABOR RATES : ANNLAL RATES : HCURLY RATES : REIMBURS -: :PTS FRCP:REIPEURS...DCAC 600-60-1 23-7 SECTION D Change I # : - TABLE 23-3. DCA MILITARY LABOR RATES - MAJOR : ANNLAL RATES : HCURLY RATES : REIMBURS -: : : : : : TS
NASA Astrophysics Data System (ADS)
Maragou, Niki C.; Thomaidis, Nikolaos S.; Koupparis, Michael A.
2011-10-01
A systematic and detailed optimization strategy for the development of atmospheric pressure ionization (API) LC-MS/MS methods for the determination of Irgarol 1051, Diuron, and their degradation products (M1, DCPMU, DCPU, and DCA) in water, sediment, and mussel is described. Experimental design was applied for the optimization of the ion sources parameters. Comparison of ESI and APCI was performed in positive- and negative-ion mode, and the effect of the mobile phase on ionization was studied for both techniques. Special attention was drawn to the ionization of DCA, which presents particular difficulty in API techniques. Satisfactory ionization of this small molecule is achieved only with ESI positive-ion mode using acetonitrile in the mobile phase; the instrumental detection limit is 0.11 ng/mL. Signal suppression was qualitatively estimated by using purified and non-purified samples. The sample preparation for sediments and mussels is direct and simple, comprising only solvent extraction. Mean recoveries ranged from 71% to 110%, and the corresponding (%) RSDs ranged between 4.1 and 14%. The method limits of detection ranged between 0.6 and 3.5 ng/g for sediment and mussel and from 1.3 to 1.8 ng/L for sea water. The method was applied to sea water, marine sediment, and mussels, which were obtained from marinas in Attiki, Greece. Ion ratio confirmation was used for the identification of the compounds.
Cocaign, Angélique; Bui, Linh-Chi; Silar, Philippe; Chan Ho Tong, Laetitia; Busi, Florent; Lamouri, Aazdine; Mougin, Christian; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Dairou, Julien
2013-08-01
Trichoderma spp. are cosmopolitan soil fungi that are highly resistant to many toxic compounds. Here, we show that Trichoderma virens and T. reesei are tolerant to aromatic amines (AA), a major class of pollutants including the highly toxic pesticide residue 3,4-dichloroaniline (3,4-DCA). In a previous study, we provided proof-of-concept remediation experiments in which another soil fungus, Podospora anserina, detoxifies 3,4-DCA through its arylamine N-acetyltransferase (NAT), a xenobiotic-metabolizing enzyme that enables acetyl coenzyme A-dependent detoxification of AA. To assess whether the N-acetylation pathway enables AA tolerance in Trichoderma spp., we cloned and characterized NATs from T. virens and T. reesei. We characterized recombinant enzymes by determining their catalytic efficiencies toward several toxic AA. Through a complementary approach, we also demonstrate that both Trichoderma species efficiently metabolize 3,4-DCA. Finally, we provide evidence that NAT-independent transformation is solely (in T. virens) or mainly (in T. reesei) responsible for the observed removal of 3,4-DCA. We conclude that T. virens and, to a lesser extent, T. reesei likely utilize another, unidentified, metabolic pathway for the detoxification of AA aside from acetylation. This is the first molecular and functional characterization of AA biotransformation in Trichoderma spp. Given the potential of Trichoderma for cleanup of contaminated soils, these results reveal new possibilities in the fungal remediation of AA-contaminated soil.
Sousa, Tânia; Castro, Rui E.; Pinto, Sandra N.; Coutinho, Ana; Lucas, Susana D.; Moreira, Rui; Rodrigues, Cecília M. P.; Prieto, Manuel; Fernandes, Fábio
2015-01-01
Cytotoxic bile acids, such as deoxycholic acid (DCA), are responsible for hepatocyte cell death during intrahepatic cholestasis. The mechanisms responsible for this effect are unclear, and recent studies conflict, pointing to either a modulation of plasma membrane structure or mitochondrial-mediated toxicity through perturbation of mitochondrial outer membrane (MOM) properties. We conducted a comprehensive comparative study of the impact of cytotoxic and cytoprotective bile acids on the membrane structure of different cellular compartments. We show that DCA increases the plasma membrane fluidity of hepatocytes to a minor extent, and that this effect is not correlated with the incidence of apoptosis. Additionally, plasma membrane fluidity recovers to normal values over time suggesting the presence of cellular compensatory mechanisms for this perturbation. Colocalization experiments in living cells confirmed the presence of bile acids within mitochondrial membranes. Experiments with active isolated mitochondria revealed that physiologically active concentrations of DCA change MOM order in a concentration- and time-dependent manner, and that these changes preceded the mitochondrial permeability transition. Importantly, these effects are not observed on liposomes mimicking MOM lipid composition, suggesting that DCA apoptotic activity depends on features of mitochondrial membranes that are absent in protein-free mimetic liposomes, such as the double-membrane structure, lipid asymmetry, or mitochondrial protein environment. In contrast, the mechanism of action of cytoprotective bile acids is likely not associated with changes in cellular membrane structure. PMID:26351365
Cocaign, Angélique; Bui, Linh-Chi; Silar, Philippe; Chan Ho Tong, Laetitia; Busi, Florent; Lamouri, Aazdine; Mougin, Christian; Rodrigues-Lima, Fernando
2013-01-01
Trichoderma spp. are cosmopolitan soil fungi that are highly resistant to many toxic compounds. Here, we show that Trichoderma virens and T. reesei are tolerant to aromatic amines (AA), a major class of pollutants including the highly toxic pesticide residue 3,4-dichloroaniline (3,4-DCA). In a previous study, we provided proof-of-concept remediation experiments in which another soil fungus, Podospora anserina, detoxifies 3,4-DCA through its arylamine N-acetyltransferase (NAT), a xenobiotic-metabolizing enzyme that enables acetyl coenzyme A-dependent detoxification of AA. To assess whether the N-acetylation pathway enables AA tolerance in Trichoderma spp., we cloned and characterized NATs from T. virens and T. reesei. We characterized recombinant enzymes by determining their catalytic efficiencies toward several toxic AA. Through a complementary approach, we also demonstrate that both Trichoderma species efficiently metabolize 3,4-DCA. Finally, we provide evidence that NAT-independent transformation is solely (in T. virens) or mainly (in T. reesei) responsible for the observed removal of 3,4-DCA. We conclude that T. virens and, to a lesser extent, T. reesei likely utilize another, unidentified, metabolic pathway for the detoxification of AA aside from acetylation. This is the first molecular and functional characterization of AA biotransformation in Trichoderma spp. Given the potential of Trichoderma for cleanup of contaminated soils, these results reveal new possibilities in the fungal remediation of AA-contaminated soil. PMID:23728813
Castillo, Jean Manuel; Nogales, Rogelio; Romero, Esperanza
2014-02-28
A hazardous contaminant, 3,4-dichloroaniline (DCA) is widespread in the environment due to its extensive use in the manufacture of chemicals and its application in different sectors. The ability of fungi grow on in winery wastes in the preconditioning period of vermicomposting to degrade DCA was investigated. Three filamentous fungi (F1, F2, and F3) were isolated and one identified as Aspergillus niger and two as Fusarium sp. strains. The culture media with the fungus alone or in consortium (Fmix) with DCA as the nitrogen source were analyzed by solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC/MS). The fastest degradation rate was measured in Fmix with a DT50 of 0.85day(-1). Fusarium sp. and A. niger differed in the metabolism of DCA. Five metabolites were identified as a result of oxidation, co-denitrification, N-acetylation, and polymerization reactions. The major metabolites were 3,4-dichloroacetanilide and dichloroquinolines. The azo-metabolites tetrachloroazobenzene and tetracloroazoxybenzene and 3,4-dichloronitrobenzene were found in minor amounts but appeared to be the most persistent in the Fusarium cultures (half-lives ranging from 8.3 to 30.9 days). This study highlights the metabolic potential of microorganisms in the preconditioning period of the vermicomposting process and its possible application for in situ bioremediation strategies. Copyright © 2014 Elsevier B.V. All rights reserved.
Regional Air Quality Model Application of the Aqueous-Phase ...
In most ecosystems, atmospheric deposition is the primary input of mercury. The total wet deposition of mercury in atmospheric chemistry models is sensitive to parameterization of the aqueous-phase reduction of divalent oxidized mercury (Hg2+). However, most atmospheric chemistry models use a parameterization of the aqueous-phase reduction of Hg2+ that has been shown to be unlikely under normal ambient conditions or use a non mechanistic value derived to optimize wet deposition results. Recent laboratory experiments have shown that Hg2+ can be photochemically reduced to elemental mercury (Hg) in the aqueous-phase by dissolved organic matter and a mechanism and the rate for Hg2+ photochemical reduction by dicarboxylic acids (DCA) has been proposed. For the first time in a regional scale model, the DCA mechanism has been applied. The HO2-Hg2+ reduction mechanism, the proposed DCA reduction mechanism, and no aqueous-phase reduction (NAR) of Hg2+ are evaluated against weekly wet deposition totals, concentrations and precipitation observations from the Mercury Deposition Network (MDN) using the Community Multiscale Air Quality (CMAQ) model version 4.7.1. Regional scale simulations of mercury wet deposition using a DCA reduction mechanism evaluated well against observations, and reduced the bias in model evaluation by at least 13% over the other schemes evaluated, although summertime deposition estimates were still biased by −31.4% against observations. The use of t
Impact of nearest-neighbor repulsion on superconducting pairing in 2D extended Hubbard model
NASA Astrophysics Data System (ADS)
Jiang, Mi; Hahner, U. R.; Maier, T. A.; Schulthess, T. C.
Using dynamical cluster approximation (DCA) with an continuous-time QMC solver for the two-dimensional extended Hubbard model, we studied the impact of nearest-neighbor Coulomb repulsion V on d-wave superconducting pairing dynamics. By solving Bethe-Salpeter equation for particle-particle superconducting channel, we focused on the evolution of leading d-wave eigenvalue with V and the momentum and frequency dependence of the corresponding eigenfunction. The comparison with the evolution of both spin and charge susceptibilities versus V is presented showing the competition between spin and charge fluctuations. This research received generous support from the MARVEL NCCR and used resources of the Swiss National Supercomputing Center, as well as (INCITE) program in Oak Ridge Leadership Computing Facility.
NASA Astrophysics Data System (ADS)
Aguilar-Perera, Alfonso; Appeldoorn, Richard S.
2008-01-01
Despite an extensive study of the fish community off southwestern Puerto Rico, little information is available on the fish spatial distribution along an inshore-offshore, cross-shelf gradient containing a continuum of mangrove-seagrass-coral reefs. We investigated the spatial distribution of reef-associated fish species using a stratified sampling procedure. A total of 52,138 fishes were recorded, representing 102 species belonging to 32 families. Significant differences in mean fish density were evident among strata. Mean densities at shallow fore reefs and deep fore reefs (Romero key) were significantly higher compared to the rest of strata along the gradient. Mean densities of fishes in mangroves and seagrass (Montalva Bay) were comparable to those at shallow back reefs and deep fore reefs offshore (Turrumote), but lower to those inshore (Romero); the lowest fish densities were found in mangroves and seagrass (Montalva Bay) and seagrass (Romero and Corral). At least 17 species, in 7 families, were among the most common in terms of relative abundance representing 76% of the total individuals sampled. A detrended correspondence analysis (DCA) applied to more abundant fish species showed a spatial pattern in density distribution. Three major groupings were evident corresponding to mangroves and seagrass (Montalva Bay), shallow and deep reefs (Romero), and shallow and deep reefs (Corral and Turrumote). A cluster analysis on mean fish densities of the more abundant species revealed a consistent spatial distribution according to biotope by separating the ichthyofauna associated with mangroves, seagrass and that of shallow (back and fore) reefs, and deep fore reefs.
Intracranial dermoid cyst rupture-related brain ischemia: Case report and hemodynamic study.
Jin, Hang; Guo, Zhen-Ni; Luo, Yun; Zhao, Ren; Sun, Ming-Shuo; Yang, Yi
2017-01-01
Spontaneous rupture of intracranial dermoid cyst is a rare but serious clinical event that can result in cerebral ischemia. Cerebral vasospasm and vasculitis are considered as potential mechanisms of dermoid cyst rupture-related cerebral ischemia. However, the hemodynamic mechanisms between cerebral ischemia and dermoid cyst rupture are not well known. A 55-year-old, right-handed man was admitted to our hospital with sudden receptive aphasia and right-sided hypoalgesia. Brain magnetic resonance imaging (MRI) revealed a ruptured dermoid cyst and watershed infarcts in the left hemisphere. Then brain magnetic resonance angiography disclosed mild stenosis in the left middle cerebral artery (MCA), and further high-resolution MRI demonstrated it was caused by an unstable atherosclerosis plaque. Transcranial Doppler of the patient showed a decreasing tendency of peak systolic velocity (PSV) of the left MCA at different time points after the stroke (from 290cm/s at day 6 to 120cm/s at day 30), indicating a transient vasospasm. However, the time course of dynamic cerebral autoregulation (dCA) seemed different from the PSV. The patient's dCA reached its lowest point at day 8 and was restored at day 10. The time course of dCA indicated a "called procedure" of a cerebrovascular regulating function to deal with the stimulation in subarachnoid space. A dermoid cyst rupture-related cerebral infarction was diagnosed in this patient. Aspirin (100 mg/d) and atorvastatin (20 mg/d) were given to the patient. A neurosurgical operation was strongly recommended to minimize the risk of further injury of the ruptured dermoid cyst; however, the patient refused the recommended treatment. The neurological deficit of the patient was significantly improved on 30 days follow-up. We found that the spread of cyst contents through the subarachnoid and/or ventricular system can induce a vasospasm. Then, dCA was "called" to deal with the stimulation in the subarachnoid space. Compromised dCA seems to be one of the compensatory of cerebral vasospasm after a dermoid cyst rupture.
NASA Astrophysics Data System (ADS)
Drozd, G.; Woo, J.; Häkkinen, S. A. K.; Nenes, A.; McNeill, V. F.
2013-11-01
Volatility and hygroscopicity are two key properties of organic aerosol components, and both are strongly related to chemical identity. Here we show that inorganic-organic component interactions typically not considered in atmospheric models may strongly affect aerosol volatility and hygroscopicity. In particular, bi-dentate binding of di-carboxylic acids (DCA) to soluble inorganic ions can lead to very strongly bound metal-organic complexes with largely undetermined hygroscopicity and volatility. These reactions profoundly impact particle hygroscopicity, transforming hygroscopic components into irreversibly non-hygroscopic material. While the hygroscopicities of pure salts, DCA, and DCA salts are known, the hygroscopicity of internal mixtures of hygroscopic salts and DCA, as they are typically found in the atmosphere, has not been fully characterized. We have studied the volatility of pure, dry organic salt particles and the hygroscopicity of internal mixtures of oxalic acid (OxA, the dominant DCA in the atmosphere) and a number of salts, both mono- and di-valent. The formation of very low volatility organic salts was confirmed, with minimal evaporation of oxalate salt particles below 75 °C. Dramatic increases in the CCN activation diameter for particles with divalent salts (e.g. CaCl2) and relatively small particle mass fractions of OxA indicate that standard volume additivity rules for hygroscopicity do not apply. Thus small organic compounds with high O:C are capable of forming low volatility and very low hygroscopicity particles. Given current knowledge of the formation mechanisms of OxA and M-Ox salts, surface enrichment of insoluble M-Ox salts is expected. The resulting formation of an insoluble coating of metal-oxalate salts can explain low particle hygroscopicities. The formation of particles with a hard coating could offer an alternative explanation for observations of glass-like particles with very low viscosity.
Ueno, Kimihiko; Ajiki, Tetsuo; Watanabe, Hisami; Abo, Toru; Takeyama, Yoshifumi; Onoyama, Hirohiko; Kuroda, Yoshikazu
2004-03-01
Recently, T cells were classified into two categories: intrathymic T cells (ITCs; thymus-derived T cells) and extrathymic T cells (ETCs). ETC, localized in the liver and intestinal intraepithelium (IE), play an important immunologic role in the suppressed condition of T-cell development in the thymus. Given the fact that complications of surgery in patients with obstructive jaundice are often related to immunosuppression in the gut-liver circulation, we attempted to investigate the changes in the proportion of ETCs in mice with obstructive jaundice. Three mice models were prepared ( n = 10 per group): sham group with simple laparotomy; ligation group with common bile duct ligation; deoxycholic acid (DCA) group with an oral intake of DCA as a model of the presence of bile salts in the gut lumen. In each model, total mononuclear cells (MNCs), ITCs in the thymus, and ETCs in the liver and IE were counted using monoclonal antibodies in conjunction with a two-color immunofluorescence test by flow cytometry. In the ligation group the number of MNCs was reduced in the thymus and IE, and only those in the IE recovered after oral intake of DCA. A decrease of ITCs in the thymus and the increase in ETCs in the liver and IE occurred simultaneously during the early phase of biliary obstruction. At day 7 after biliary obstruction, ETCs in the livers of the DCA and ligation groups decreased to nearly the level in the sham group. However, on day 7 the ETCs in the IE remained significantly higher in the DCA group than in the ligation group. These results suggested that ETCs can act in place of ITCs at an early phase of obstructive jaundice, and the presence of bile in the gut lumen may be associated with the consumption of ETCs in the IE, a reaction that may bring about improved immunoreactivity.
Andersen, Aaron John Christian; Hansen, Per Juel; Jørgensen, Kevin; Nielsen, Kristian Fog
2016-12-20
Dynamic cluster analysis (DCA) is an automated, unbiased technique which can identify Cl, Br, S, and other A + 2 element containing metabolites in liquid chromatographic high-resolution mass spectrometric data. DCA is based on three features, primarily the previously unutilized A + 1 to A + 2 isotope cluster spacing which is a strong classifier in itself but improved with the addition of the monoisotopic mass, and the well-known A:A+2 intensity ratio. Utilizing only the A + 1 to A + 2 isotope cluster spacing and the monoisotopic mass it was possible to filter a chromatogram for metabolites which contain Cl, Br, and S. Screening simulated isotope patterns of the Antibase Natural Products Database it was determined that the A + 1 to A + 2 isotope cluster spacing can be used to correctly classify 97.4% of molecular formulas containing these elements, only misclassifying a few metabolites which were either over 2800 u or metabolites which contained other A + 2 elements, such as Cu, Ni, Mg, and Zn. It was determined that with an interisotopic mass accuracy of 1 ppm, in a fully automated process, using all three parameters, it is possible to specifically filter a chromatogram for S containing metabolites with monoisotopic masses less than 825 u. Furthermore, it was possible to specifically filter a chromatogram for Cl and Br containing metabolites with monoisotopic masses less than 1613 u. Here DCA is applied on (i) simulated isotope patterns of the Antibase natural products databases, (ii) LC-QTOF data of reference standards, and (iii) LC-QTOF data of crude extracts of 10 strains of laboratory grown cultures of the microalga Prymnesium parvum where it identified known metabolites of the prymnesin series as well as over 20 previously undescribed prymnesin-like molecular features.
2015-01-01
The observed toxicity and carcinogenicity of 1,3-dichloro-2-propanol (DCP) in rodents is thought to be due to the formation of reactive metabolites, epichlorohydrin (ECH) and dichloroacetone (DCA). However, there is no direct evidence for the formation of these metabolites from exposure to DCP in rodents due to the challenges of measuring these reactive intermediates directly in vivo. The objective of this work was to investigate the metabolism of DCP to ECH and DCA in vivo by first developing a sensitive analytical method in a suitable biological matrix and analyzing samples from rats administered DCP. DCA reacted rapidly in vitro in rat blood, plasma, and liver homogenate, precluding its detection. Because ECH rapidly disappeared in liver homogenate, but was relatively long-lived in plasma and blood in vitro, blood was selected for analysis of this metabolite. Following a single oral dose of 50 mg/kg DCP in male or female Harlan Sprague–Dawley rats, ECH was detected in blood with a maximum concentration reached at ≤13.7 min. ECH was cleared rapidly with a half-life of ca. 33 and 48 min in males and females, respectively. Following a single oral dose of 25 mg/kg ECH in male and female rats, the elimination half-life of ECH was ca. 34 and 20 min, respectively; the oral bioavailability of ECH was low (males, 5.2%; females, 2.1%), suggesting extensive first pass metabolism of ECH following oral administration. The area under the concentration vs time curve for ECH following oral administration of DCP and intravenous administration of ECH was used to estimate the percent of the DCP dose converted to ECH in rats. On the basis of this analysis, we concluded that in male and female rats following oral administration of 50 mg/kg DCP, ≥1.26% or ≥1.78% of the administered dose was metabolized to ECH, respectively. PMID:25254956
Aircraft Energy Conservation during Airport Ground Operations
1982-03-01
minimized. The model can be run in a non -optimizing mode to simulate movements along pre-assigned taxi paths. 8-6 The model is also designed ...5.5 5.6 5.7 Engine Designation by Airline and Aircraft Type IAD 2-6 Engine Designation by Airline and Aircraft Type DCA 2-7 Fuel Flow Rates...B.2 CY 1979 Aircraft Operations at IAD and DCA Airports . . 3-5 B.3 1979 Scheduled and Non -Scheduled Departures from IAD by Aircraft Type and
Non-Hodgkin's Lymphoma Reversal with Dichloroacetate.
Flavin, Dana F
2010-01-01
In June 2007, a 48-year-old male patient, diagnosed with Stage 4 Non-Hodgkin's Follicular Lymphoma (NHL), was treated for 3 months with conventional chemotherapy resulting in a complete remission. Almost one year later tumors returned in the nasopharynx and neck lymph glands. Refusing all suggested chemotherapies, the patient began self-administering dichloroacetate (DCA) 900 mg daily with a PET scan showing complete remission four months later. Since his last PET scan, May, 2009, he remains tumor-free from continuous DCA usage.
Non-Hodgkin's Lymphoma Reversal with Dichloroacetate
Flavin, Dana F.
2010-01-01
In June 2007, a 48-year-old male patient, diagnosed with Stage 4 Non-Hodgkin's Follicular Lymphoma (NHL), was treated for 3 months with conventional chemotherapy resulting in a complete remission. Almost one year later tumors returned in the nasopharynx and neck lymph glands. Refusing all suggested chemotherapies, the patient began self-administering dichloroacetate (DCA) 900 mg daily with a PET scan showing complete remission four months later. Since his last PET scan, May, 2009, he remains tumor-free from continuous DCA usage. PMID:20886020
Beinke, C; Port, M; Ullmann, R; Gilbertz, K; Majewski, M; Abend, M
2018-06-01
Dicentric chromosome analysis (DCA) is the gold standard for individual radiation dose assessment. However, DCA is limited by the time-consuming phytohemagglutinin (PHA)-mediated lymphocyte activation. In this study using human peripheral blood lymphocytes, we investigated PHA-associated whole genome gene expression changes to elucidate this process and sought to identify suitable gene targets as a means of meeting our long-term objective of accelerating cell cycle kinetics to reduce DCA culture time. Human peripheral whole blood from three healthy donors was separately cultured in RPMI/FCS/antibiotics with BrdU and PHA-M. Diluted whole blood samples were transferred into PAXgene tubes at 0, 12, 24 and 36 h culture time. RNA was isolated and aliquots were used for whole genome gene expression screening. Microarray results were validated using qRT-PCR and differentially expressed genes [significantly (FDR corrected) twofold different from the 0 h value reference] were analyzed using several bioinformatic tools. The cell cycle positions and DNA-synthetic activities of lymphocytes were determined by analyzing the correlated total DNA content and incorporated BrdU level with flow cytometry after continued BrdU incubation. From 42,545 transcripts of the whole genome microarray 47.6%, on average, appeared expressed. The number of differentially expressed genes increased linearly from 855 to 2,858 and 4,607 at 12, 24 and 36 h after PHA addition, respectively. Approximately 2-3 times more up- than downregulated genes were observed with several hundred genes differentially expressed at each time point. Earliest enrichment was observed for gene sets related to the nucleus (12 h) followed by genes assigned to intracellular structures such as organelles (24 h) and finally genes related to the membrane and the extracellular matrix were enriched (36 h). Early gene expression changes at 12 h, in particular, were associated with protein classes such as chemokines/cytokines (e.g., CXCL1, CXCL2) and chaperones. Genes coding for biological processes involved in cell cycle control (e.g., MYBL2, RBL1, CCNA, CCNE) and DNA replication (e.g., POLA, POLE, MCM) appeared enriched at 24 h and later, but many more biological processes (42 altogether) showed enrichment as well. Flow cytometry data fit together with gene expression and bioinformatic analyses as cell cycle transition into S phase was observed with interindividual differences from 12 h onward, whereas progression into G 2 as well as into the second G 1 occurred from 36 h onward after activation. Gene set enrichment analysis over time identifies, in particular, two molecular categories of PHA-responsive gene targets (cytokine and cell cycle control genes). Based on that analysis target genes for cell cycle acceleration in lymphocytes have been identified ( CDKN1A/B/C, RBL-1/RBL-2, E2F2, Deaf-1), and it remains undetermined whether the time expenditure for DCA can be reduced by influencing gene expression involved in the regulatory circuits controlling PHA-associated cell cycle entry and/or progression at a specific early cell cycle phase.
NASA Astrophysics Data System (ADS)
Xu, M.; Ivey, D. G.; Qu, W.; Xie, Z.
2015-01-01
Electrodeposition of Zn was conducted in a new electrolyte system composed of an alkaline solution (9 M KOH + 5 wt% ZnO) modified with a small amount (0.5 wt%) of room temperature ionic liquid 1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA). At a high deposition current density of 80 mA cm-2, a porous, dendrite-free Zn film characterized by clusters of small Zn particles was obtained. The mechanism for the modified Zn morphology in the EMI-DCA containing electrolyte was studied by cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy. It was found that the addition of EMI-DCA changed the Zn nucleation process and reduced the potential variation during electrodeposition, which suppressed the uneven growth of Zn deposits and the formation of Zn dendrites. EIS results indicated that there was adsorption of EMI+ cations at the Zn film/electrolyte interface, which may have contributed to suppressed dendritic Zn growth.
NASA Astrophysics Data System (ADS)
Kim, SungKun; Lee, Hunpyo
2017-06-01
Via a dynamical cluster approximation with N c = 4 in combination with a semiclassical approximation (DCA+SCA), we study the doped two-dimensional Hubbard model. We obtain a plaquette antiferromagnetic (AF) Mott insulator, a plaquette AF ordered metal, a pseudogap (or d-wave superconductor) and a paramagnetic metal by tuning the doping concentration. These features are similar to the behaviors observed in copper-oxide superconductors and are in qualitative agreement with the results calculated by the cluster dynamical mean field theory with the continuous-time quantum Monte Carlo (CDMFT+CTQMC) approach. The results of our DCA+SCA differ from those of the CDMFT+CTQMC approach in that the d-wave superconducting order parameters are shown even in the high doped region, unlike the results of the CDMFT+CTQMC approach. We think that the strong plaquette AF orderings in the dynamical cluster approximation (DCA) with N c = 4 suppress superconducting states with increasing doping up to strongly doped region, because frozen dynamical fluctuations in a semiclassical approximation (SCA) approach are unable to destroy those orderings. Our calculation with short-range spatial fluctuations is initial research, because the SCA can manage long-range spatial fluctuations in feasible computational times beyond the CDMFT+CTQMC tool. We believe that our future DCA+SCA calculations should supply information on the fully momentum-resolved physical properties, which could be compared with the results measured by angle-resolved photoemission spectroscopy experiments.
Bertrand, Bénédicte; Alburaki, Mohamed; Legout, Hélène; Moulin, Sibyle; Mougel, Florence; Garnery, Lionel
2015-05-01
Honeybee subspecies have been affected by human activities in Europe over the past few decades. One such example is the importation of nonlocal subspecies of bees which has had an adverse impact on the geographical repartition and subsequently on the genetic diversity of the black honeybee Apis mellifera mellifera. To restore the original diversity of this local honeybee subspecies, different conservation centres were set up in Europe. In this study, we established a black honeybee conservation centre Conservatoire de l'Abeille Noire d'Ile de France (CANIF) in the region of Ile-de-France, France. CANIF's honeybee colonies were intensively studied over a 3-year period. This study included a drone congregation area (DCA) located in the conservation centre. MtDNA COI-COII marker was used to evaluate the genetic diversity of CANIF's honeybee populations and the drones found and collected from the DCA. The same marker (mtDNA) was used to estimate the interactions and the haplotype frequency between CANIF's honeybee populations and 10 surrounding honeybee apiaries located outside of the CANIF. Our results indicate that the colonies of the conservation centre and the drones of the DCA show similar stable profiles compared to the surrounding populations with lower level of introgression. The mtDNA marker used on both DCA and colonies of the conservation centre seems to be an efficient approach to monitor and maintain the genetic diversity of the protected honeybee populations. © 2014 John Wiley & Sons Ltd.
An, Rui; Tang, Zhiru; Li, Yunxia; Li, Tiejun; Xu, Qingqing; Zhen, Jifu; Huang, Feiru; Yang, Jing; Chen, Cheng; Wu, Zhaoliang; Li, Mao; Sun, Jiajing; Zhang, Xiangxin; Chen, Jinchao; Wu, Liuting; Zhao, Shengjun; Qingyan, Jiang; Zhu, Weiyun; Yin, Yulong; Sun, Zhihong
2018-04-18
The extensive metabolism of amino acids (AA) as fuel is an important reason for the low use efficiency of protein in pigs. In this study, we investigated whether regulation of the pyruvate dehydrogenase kinase (PDK)/pyruvate dehydrogenase alpha 1 (PDHA1) pathway affected AA consumption by porcine intestinal epithelial (IPEC-J2) cells and intestinal bacteria in pigs. The effects of knockdown of PDHA1 and PDK1 with small interfering RNA (siRNA) on nutrient consumption by IPEC-J2 cells were evaluated. IPEC-J2 cells were then cultured with sodium dichloroacetate (DCA) to quantify AA and glucose consumption and nutrient oxidative metabolism. The results showed that knockdown of PDHA1 using siRNA decreased glucose consumption but increased total AA (TAA) and glutamate (Glu) consumption by IPEC-J2 cells ( P < 0.05). Opposite effects were observed using siRNA targeting PDK1 ( P < 0.05). Additionally, culturing IPEC-J2 cells in the presence of 5 mM DCA markedly increased the phosphorylation of PDHA1 and PDH phosphatase 1, but inhibited PDK1 phosphorylation ( P < 0.05). DCA treatment also reduced TAA and Glu consumption and increased glucose depletion ( P < 0.05). These results indicated that PDH was the regulatory target for shifting from AA metabolism to glucose metabolism and that culturing cells with DCA decreased the consumption of AAs by increasing the depletion of glucose through PDH activation.
NASA Technical Reports Server (NTRS)
Herman, Daniel A.; Gallimore, Alec D.
2006-01-01
Floating emissive probe plasma potential data are presented over a two-dimensional array of locations in the near Discharge Cathode Assembly (DCA) region of a 30-cm diameter ring-cusp ion thruster. Discharge plasma data are presented with beam extraction at throttling conditions comparable to the NASA TH Levels 8, 12, and 15. The operating conditions of the Extended Life Test (ELT) of the Deep Space One (DS1) flight spare ion engine, where anomalous discharge keeper erosion occurred, were TH 8 and TH 12 consequently they are of specific interest in investigating discharge keeper erosion phenomena. The data do not validate the presence of a potential hill plasma structure downstream of the DCA, which has been proposed as a possible erosion mechanism. The data are comparable in magnitude to data taken by other researchers in ring-cusp electron-bombardment ion thrusters. The plasma potential structures are insensitive to thruster throttling level with a minimum as low as 14 V measured at the DCA exit plane and increasing gradually in the axial direction. A sharp increase in plasma potential to the bulk discharge value of 26 to 28 volts, roughly 10 mm radially from DCA centerline, was observed. Plasma potential measurements indicate a low-potential plume structure that is roughly 20 mm in diameter emanating from the discharge cathode that may be attributed to a free-standing plasma double layer.
Noh, Yongjoon
2012-01-01
Background Phosphatidylcholine (PPC) and deoxycholate (DCA) compound has been recently used for the purpose of partial lipolysis and is valued for its efficacy and lower invasiveness compared to liposuction and dermolipectomy used previously. In this article, the authors discuss the efficacy of the PPC dissolved in DCA via an experimental rat study model, along with suggesting a useful animal experimental model for the study of adipose tissue and lipolysis. Methods Bilateral inguinal fat pads of an experimental rat were elevated with the deep inferior epigastric vessel as the sole vascular pedicle. Normal saline was injected on one side as a control group and a PPC and DCA compound was injected on the other side. After 4 days, the rats were euthanized for microscopic tissue examination. The pathology was scored by a semiquantitative system in 4 categories: normal fat amount, fat necrosis, inflammatory activity, and stage of fibrosis. A Wilcoxon signed-rank test powered by SPSS packet program was used for statistical analysis and to determine significance. Results Microscopic examination was performed on the obtained samples, and the experimental data of all four categories showed significant histologic differences compared to the control group. All of the data also showed statistical significance by the Wilcoxon signedrank test (P<0.01). Conclusions In the inguinal fat pad rat model, the control group and the experimental group had a differed significantly in the amount of normal fat tissue, inflammation, necrosis, and fibrosis. We recommend the rat inguinal fat pad model used in this study, as it is likely to be useful in related research. PMID:23094238
Stressful events and coping related to acute and sub-acute whiplash-associated disorders.
Pettersson, Susanne; Bring, Annika; Åsenlöf, Pernilla
2017-03-01
Purpose To describe daily stressors affecting and coping strategies employed by individuals with whiplash-associated disorders (WAD) immediately to one month (acute) and three to four months (sub-acute) after injury events using a daily coping assessment. Levels of pain, anxiety, depressed mood and activity are also compared between phases. Method A descriptive prospective design with a content analysis approach was used. Participants completed daily coping assessments for one week during both acute and sub-acute phases. Main measure was whiplash-associated disorders-daily coping assessment (WAD-DCA). Results Nine participants used words describing recovery in the sub-acute phase; 31 described stressful events during both phases. Most frequently reported stressors were related to "symptoms", "emotions" and "occupations/studies". These were equally reported during both phases. Cognitive coping strategies were employed more often during the sub-acute phase (p = 0.008). The only behavioral strategy that increased in prevalence over time was the "relaxed" strategy (p = 0.001). Anxiety levels declined over time (p = 0.022). Conclusion The reported stressors were largely uniform across both acute and sub-acute phases; however, the use of cognitive coping strategies increased over time. The WAD-DCA captures individual stressors and coping strategies employed during a vulnerable phase of rehabilitation and can thus provide information that is useful to clinical practice. Implications for rehabilitation The WAD-DCA provides valuable information for clinical practice when employed during early phases of whiplash-associated disorder development. Reported stressors during the acute and sub-acute phases are essentially the same, whereas cognitive coping strategies grow in prevalence over time. Tailored treatments in early phases of whip-lash associated disorders may benefit from strategies aimed at matching patient-specific stressors with contextually adapted coping strategies.
Demonstration of the Gore Module for Passive Ground Water Sampling
2014-06-01
ix ACRONYMS AND ABBREVIATIONS % RSD percent relative standard deviation 12DCA 1,2-dichloroethane 112TCA 1,1,2-trichloroethane 1122TetCA...Analysis of Variance ROD Record of Decision RSD relative standard deviation SBR Southern Bush River SVOC semi-volatile organic compound...replicate samples had a relative standard deviation ( RSD ) that was 20% or less. For the remaining analytes (PCE, cDCE, and chloroform), at least 70
Bovine serum albumin adsorption on titania surfaces and its relation to wettability aspects.
Valagão Amadeu do Serro, A P; Fernandes, A C; de Jesus Vieira Saramago, B; Norde, W
1999-09-05
The adsorption of bovine serum albumin (BSA) from sodium chloride solution and Hanks' balanced salt solution (HBSS) onto TiO2-silicon surfaces is studied by reflectometry in stagnation point flow. The results are compared with those obtained by dynamic contact-angle (DCA) analysis of titanium substrates. The adsorption isotherms show that the adsorbed amount of protein always is lower in HBSS, that is, in the presence of calcium and phosphate ions. This may be related to the increase in surface hydrophilicity caused by these ions, as suggested by the authors in previous works. The rate of adsorption also is lower in HBSS solutions. Comparison of the initial adsorption rates with the rate of mass transfer to the surface reveals that in both solvents only a small fraction of the protein that arrives at the surface adsorbs onto it. Electrostatic and/or conformational effects can explain the energy barrier to adsorption. The DCA analysis of high concentration (4 mg/mL) protein solutions shows a strong reduction of the contact-angle hysteresis, both in HBSS and in NaCl solutions, which confirms that the immediate adsorption of the protein to the surface forms a stable, hydrophilic film. Copyright 1999 John Wiley & Sons, Inc.
Deep features for efficient multi-biometric recognition with face and ear images
NASA Astrophysics Data System (ADS)
Omara, Ibrahim; Xiao, Gang; Amrani, Moussa; Yan, Zifei; Zuo, Wangmeng
2017-07-01
Recently, multimodal biometric systems have received considerable research interest in many applications especially in the fields of security. Multimodal systems can increase the resistance to spoof attacks, provide more details and flexibility, and lead to better performance and lower error rate. In this paper, we present a multimodal biometric system based on face and ear, and propose how to exploit the extracted deep features from Convolutional Neural Networks (CNNs) on the face and ear images to introduce more powerful discriminative features and robust representation ability for them. First, the deep features for face and ear images are extracted based on VGG-M Net. Second, the extracted deep features are fused by using a traditional concatenation and a Discriminant Correlation Analysis (DCA) algorithm. Third, multiclass support vector machine is adopted for matching and classification. The experimental results show that the proposed multimodal system based on deep features is efficient and achieves a promising recognition rate up to 100 % by using face and ear. In addition, the results indicate that the fusion based on DCA is superior to traditional fusion.
Multileaf collimator-based linear accelerator radiosurgery: five-year efficiency analysis.
Lawson, Joshua D; Fox, Tim; Waller, Anthony F; Davis, Lawrence; Crocker, Ian
2009-03-01
In 1989, Emory University initiated a linear accelerator (linac) radiosurgery program using circular collimators. In 2001, the program converted to a multileaf collimator. Since then, the treatment parameters of each patient have been stored in the record-and-verify system. Three major changes have occurred in the radiosurgery program in the past 6 years: in 2002, treatment was changed from static conformal beams to dynamic conformal arc (DCA) therapy, and all patients were imaged before treatment. Beginning in 2005, a linac was used, with the opportunity to treat at higher dose rates (600-1,000 monitor units/min). The aim of this study was to analyze the time required to deliver radiosurgery and the factors affecting treatment delivery. Benchmark data are provided for centers contemplating initiating linac radiosurgery programs. Custom software was developed to mine the record-and-verify system database and automatically perform a chart review on patients who underwent stereotactic radiosurgery from March 2001 to October 2006. The software extracted 510 patients who underwent stereotactic radiosurgery, and the following information was recorded for each patient: treatment technique, treatment time (from initiation of imaging, if done, to completion of therapy), number of isocenters, number of fields, total monitor units, and dose rate. Of the 510 patients, 395 were treated with DCA therapy and 115 with static conformal beams. The average number of isocenters treated was 1.06 (range, 1-4). The average times to deliver treatment were 24.1 minutes for patients who underwent DCA therapy and 19.3 minutes for those treated with static conformal beams, reflecting the lack of imaging in the latter patients. Eighty percent of patients were treated in <30 minutes. For the patients who underwent DCA therapy, the times required to treat 1, 2, 3, and 4 isocenters were 23.9, 24.8, 33.1, and 37.8 minutes, respectively. Average beam-on time for these patients was 11.4 minutes. There has been no significant reduction in treatment delivery with the use of 1,000 monitor units/min, reflecting the fact that beam-on time is not the major determinant of overall treatment time. Multileaf collimator-based linac radiosurgery can be delivered efficiently in <30 minutes in the vast majority of patients. Given the limited treatment room utilization required for stereotactic radiosurgery treatments, this study calls into question the need for a dedicated radiosurgery unit for even busy treatment centers.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Qin, Y; Gardner, S; Huang, Y
Purpose: To evaluate the performance of a commercial plastic scintillator detector (PSD) for small-field stereotactic patient-specific quality assurance using flattening-filter-free (FFF) beams. Methods: A total of ten spherical targets (volume range:[0.03cc–2cc]) were planned using Dynamic Conformal Arc(DCA-10 plans) and Volumetric Modulated Arc Therapy(VMAT-10 plans) techniques in Eclipse(AAA v.11, 1mm dose calculation grid size). Additionally, 15 previously-treated cranial and spine SRS plans were evaluated (6 DCA, 9 VMAT, volume range:[0.04cc–119.02cc]). All measurements were acquired using Varian Edge equipped with HDMLC. Three detectors were used: PinPoint ion chamber (PTW;active volume 0.015cc), Exradin W1 PSD (Standard Imaging;active volume 0.002cc), and Gafchromic EBT3 filmmore » (Ashland). PinPoint and PSD were positioned perpendicular to beam axis in a Lucy phantom (Standard Imaging). Films were placed at isocenter in solid water. Calibration films were delivered for absolute dose analysis. Results: For large spherical targets(>1.5cc) with DCA, all detectors agreed within 1% of AAA calculations. As target volume decreased, PSD measured higher doses than AAA (maximum difference: 3.3% at 0.03cc target), while PinPoint chamber measured lower doses (maximum difference:-3.8% at 0.03cc target). Inter-detector differences between pinpoint and PSD increased with decreasing target size; differences>5% were observed for targets<0.09cc. Similar trends for inter-detector behavior were observed for clinical plans. For target sizes<0.08cc, PSD measured>5% higher dose than PinPoint chamber (maximum difference: 9.25% at 0.04cc target). Film demonstrated agreement of −0.19±1.47% with PSD for all spherical targets, and agreement within −0.98±2.25% for all 15 clinical targets. Unlike DCA, VMAT plans did not show improved AAA-to-detector agreements for large targets. Conclusion: For all targets, the PSD measurements agreed with film within 1.0%, on average. For small volume targets (<0.10cc), PSD agreed with film but measured significantly higher doses (>5%) compared with the pin point ion chamber. The plastic scintillator detector appears to be suitable for accurate measurements of small SRS targets.« less
Curatolo, William; Liu, Ping; Johnson, Barbara A; Hausberger, Angela; Quan, Ernest; Vendola, Thomas; Vatsaraj, Neha; Foulds, George; Vincent, John; Chandra, Richa
2011-07-01
Commercial azithromycin gelatin capsules (Zithromax®) are known to be bioequivalent to commercial azithromycin tablets (Zithromax®) when dosed in the fasted state. These capsules exhibit a reduced bioavailability when dosed in the fed state, while tablets do not. This gelatin capsule negative food effect was previously proposed to be due to slow and/or delayed capsule disintegration in the fed stomach, resulting in extended exposure of the drug to gastric acid, leading to degradation to des-cladinose-azithromycin (DCA). Azithromycin gelatin capsules were formulated with "superdisintegrants" to provide fast-dissolving capsules, and HPMC capsule shells were substituted for gelatin capsule shells, in an effort to eliminate the food effect. Healthy volunteers were dosed with these dosage forms under fasted and fed conditions; pharmacokinetics were evaluated. DCA pharmacokinetics were also evaluated for the HPMC capsule subjects. In vitro disintegration of azithromycin HPMC capsules in media containing food was evaluated and compared with commercial tablets and commercial gelatin capsules. When the two fast-dissolving capsule formulations were dosed to fed subjects, the azithromycin AUC was 38.9% and 52.1% lower than after fasted-state dosing. When HPMC capsules were dosed to fed subjects, the azithromycin AUC was 65.5% lower than after fasted-state dosing. For HPMC capsules, the absolute fasting-state to fed-state decrease in azithromycin AUC (on a molar basis) was similar to the increase in DCA AUC. In vitro capsule disintegration studies revealed extended disintegration times for commercial azithromycin gelatin capsules and HPMC capsules in media containing the liquid foods milk and Ensure®. Interaction of azithromycin gelatin and HPMC capsules with food results in slowed disintegration in vitro and decreased bioavailability in vivo. Concurrent measurement of serum azithromycin and the acid-degradation product DCA demonstrates that the loss of azithromycin bioavailability in the fed state is largely (and probably entirely) due to gastric degradation to DCA. Capsules can provide a useful and elegant dosage form for almost all drugs, but may result in a negative food effect for drugs as acid-labile as azithromycin.
Lertpiriyapong, Kvin; Gamazon, Eric R; Feng, Yan; Park, Danny S; Pang, Jassia; Botka, Georgina; Graffam, Michelle E; Ge, Zhongming; Fox, James G
2012-01-01
The recently identified type VI secretion system (T6SS) of proteobacteria has been shown to promote pathogenicity, competitive advantage over competing microorganisms, and adaptation to environmental perturbation. By detailed phenotypic characterization of loss-of-function mutants, in silico, in vitro and in vivo analyses, we provide evidence that the enteric pathogen, Campylobacter jejuni, possesses a functional T6SS and that the secretion system exerts pleiotropic effects on two crucial processes--survival in a bile salt, deoxycholic acid (DCA), and host cell adherence and invasion. The expression of T6SS during initial exposure to the upper range of physiological levels of DCA (0.075%-0.2%) was detrimental to C. jejuni proliferation, whereas down-regulation or inactivation of T6SS enabled C. jejuni to resist this effect. The C. jejuni multidrug efflux transporter gene, cmeA, was significantly up-regulated during the initial exposure to DCA in the wild type C. jejuni relative to the T6SS-deficient strains, suggesting that inhibition of proliferation is the consequence of T6SS-mediated DCA influx. A sequential modulation of the efflux transporter activity and the T6SS represents, in part, an adaptive mechanism for C. jejuni to overcome this inhibitory effect, thereby ensuring its survival. C. jejuni T6SS plays important roles in host cell adhesion and invasion as T6SS inactivation resulted in a reduction of adherence to and invasion of in vitro cell lines, while over-expression of a hemolysin co-regulated protein, which encodes a secreted T6SS component, greatly enhanced these processes. When inoculated into B6.129P2-IL-10(tm1Cgn) mice, the T6SS-deficient C. jejuni strains did not effectively establish persistent colonization, indicating that T6SS contributes to colonization in vivo. Taken together, our data demonstrate the importance of bacterial T6SS in host cell adhesion, invasion, colonization and, for the first time to our knowledge, adaptation to DCA, providing new insights into the role of T6SS in C. jejuni pathogenesis.
Valenti, Ornella; Mikus, Nace; Klausberger, Thomas
2018-05-22
The ability to recognize novel situations is among the most fascinating and vital of the brain functions. A hypothesis posits that encoding of novelty is prompted by failures in expectancy, according to computation matching incoming information with stored events. Thus, unexpected changes in context are detected within the hippocampus and transferred to downstream structures, eliciting the arousal of the dopamine system. Nevertheless, the precise locus of detection is a matter of debate. The dorsal CA1 hippocampus (dCA1) appears as an ideal candidate for operating a mismatch computation and discriminating the occurrence of diverse stimuli within the same environment. In this study, we sought to determine dCA1 neuronal firing during the experience of novel stimuli embedded in familiar contexts. We performed population recordings while head-fixed mice navigated virtual environments. Three stimuli were employed, namely a novel pattern of visual cues, an odor, and a reward with enhanced valence. The encounter of unexpected events elicited profound variations in dCA1 that were assessed both as opposite rate directions and altered network connectivity. When experienced in sequence, novel stimuli elicited specific responses that often exhibited cross-sensitization. Short-latency, event-triggered responses were in accordance with the detection of novelty being computed within dCA1. We postulate that firing variations trigger neuronal disinhibition, and constitute a fundamental mechanism in the processing of unexpected events and in learning. Elucidating the mechanisms underlying detection and computation of novelty might help in understanding hippocampal-dependent cognitive dysfunctions associated with neuropathologies and psychiatric conditions.
NASA Astrophysics Data System (ADS)
Müller, K.; van Pinxteren, D.; Plewka, A.; Svrcina, B.; Kramberger, H.; Hofmann, D.; Bächmann, K.; Herrmann, H.
An extensive set of gaseous and particulate organic compounds was quantified before an orographic cloud passage at the upwind site of the research region in Thüringer Wald. Samples were collected with two different time resolutions, 2 h for gaseous species and spray absorber samples and the whole cloud event duration to determine the concentrations of ketones, aldehydes, monocarboxylic acids, dicarboxylic acids (DCA), hydrocarbons, biogenic sugars and alcohols in both the gas and particle phase. The measurement of different groups of organic compounds delivered size-segregated concentrations at the upwind site of a cloud experiment. The size distribution of DCA showed a peak in the mass-rich impactor stage 3 (0.42-1.2 μm). The concentrations of DCA from the filters, the impactor foils as well as the spray absorber samples decreased with increasing C-number. The time resolved measurements revealed an increasing mixing ratio from night time to midday for carboxylic and DCA, and related carbonyl compounds. The biogenic compounds xylitol (up to 103 ng m -3), levoglucosan (up to 62 ng m -3) and pinonaldehyde (up to 34 ng m -3) were the compounds found in highest concentrations in the particle phase beside the oxalate (up to 104 ng m -3). The organic trace gases with the highest mixing ratios identified were formaldehyde (up to 1.47 ppbv), acetaldehyde (up to 0.84 ppbv) and acetone (up to 0.65 ppbv), acetic acid (up to 0.43 ppbv) and formic acid (up to 0.41 ppbv).
Henry, Hugues; Bruce, Stephen J.; Aeby, Sébastien; Rosikiewicz, Marta; Sykiotis, Gerasimos P.; Asrih, Mohammed; Jornayvaz, François R.; Denechaud, Pierre Damien; Mohammadi, Moosa; Acierno, James S.; Schoonjans, Kristina; Pitteloud, Nelly
2017-01-01
β-Klotho (encoded by Klb) is the obligate coreceptor mediating FGF21 and FGF15/19 signaling. Klb–/– mice are refractory to beneficial action of pharmacological FGF21 treatment including stimulation of glucose utilization and thermogenesis. Here, we investigated the energy homeostasis in Klb–/– mice on high-fat diet in order to better understand the consequences of abrogating both endogenous FGF15/19 and FGF21 signaling during caloric overload. Surprisingly, Klb–/– mice are resistant to diet-induced obesity (DIO) owing to enhanced energy expenditure and BAT activity. Klb–/– mice exhibited not only an increase but also a shift in bile acid (BA) composition featured by activation of the classical (neutral) BA synthesis pathway at the expense of the alternative (acidic) pathway. High hepatic production of cholic acid (CA) results in a large excess of microbiota-derived deoxycholic acid (DCA). DCA is specifically responsible for activating the TGR5 receptor that stimulates BAT thermogenic activity. In fact, combined gene deletion of Klb and Tgr5 or antibiotic treatment abrogating bacterial conversion of CA into DCA both abolish DIO resistance in Klb–/– mice. These results suggested that DIO resistance in Klb–/– mice is caused by high levels of DCA, signaling through the TGR5 receptor. These data also demonstrated that gut microbiota can regulate host thermogenesis via conversion of primary into secondary BA. Pharmacologic or nutritional approaches to selectively modulate BA composition may be a promising target for treating metabolic disorders. PMID:28422755
NASA Astrophysics Data System (ADS)
Baranova, Alina; Schickhoff, Udo; Shunli, Wang; Ming, Jin
2015-04-01
Qilian Mountains are the water source region for the low arid reaches of HeiHe river basin (Gansu province, NW China). Due to overstocking and overgrazing during the last decades adverse ecological ef¬fects, in particular on soil properties and hydrological cycle, are to be expected in growing land areas. Vegetation cover is very important to prevent erosion process and to sustain stable subsurface runoff and ground water flow. The aim of this research is to identify plant communities, detecting grazing-induced and spatially differentiated changes in vegetation patterns, and to evaluate status of pasture land degradation.The study area is located in the spring/autumn pasture area of South Qilian Mountains between 2600-3600 m a.s.l., covering five main vegetation types: spruce forest, alpine shrubland, shrubby grassland, mountain grassland, degraded mountain grassland. In order to analyze gradual changes in vegetation patterns along altitudinal and grazing gradients and to classify related plant communities, quantitative and qualitative relevé data were collected (coverage, species composition, abundance of unpalatable plants, plant functional types, etc.). Vegetation was classified using hierarchical cluster analyses. Indirect Detrended Correspondence Analysis (DCA) was used to analyze variation in relationships between vegetation, environmental factors, and grazing impact. According to DCA results, distribution of the plant communities was strongly affected by altitude and exposition. Grassland floristic gradients showed greater dependence on grazing impact, which correlated contrarily with soil organic content, soil moisture and pH. Highest numbers of species richness and alpha diversity were detected in alpine shrubland vegetation type. Comparing the monitoring data for the recent nine years, a trend of deterioration, species successions and shift in dominant species becomes obvious. Species indicating degrading site environmental conditions were identified. Most of the grasslands have become secondary vegetation, with a considerable percentage of unpalatable, toxic and often thorny or spiny shrub and herb species that have a lower grazing value and rarely form a closed vegetation cover, at least in loess slopes. To prevent further degradation of the grassland and to sustain the diversity of the plant species (affecting the carrying capacity pastureland) appropriate pasture management strategy should be implemented.
Evaluation of the DCA Vantage analyzer for HbA 1c assay.
Szymezak, Jean; Leroy, Nathalie; Lavalard, Emmanuelle; Gillery, Philippe
2008-01-01
Measurement of HbA 1c is key in monitoring diabetic patients in both laboratories and clinical units, where HbA 1c results are used as part of patient education. We have evaluated the DCA Vantage, a new device for immunological assay of HbA 1c. HbA 1c results obtained were evaluated in terms of precision, linearity, specificity and practicability, and were compared with results obtained by a Variant II HPLC method. The method exhibited intra- and inter-assay coefficients of variation lower than 2.6% and 4.0%, respectively, and good correlation with the comparison HPLC method (r2=0.9776). No interference was noted in the presence of labile HbA 1c or carbamylated hemoglobin. The new device exhibited improved practicability characteristics and allowed better sample identification, better management of quality control routines and greater connectivity possibilities compared to the previous DCA 2000 analyzer. This new analyzer exhibited analytical and practical characteristics very suitable for HbA 1c assay for laboratory or point-of-care use according to good laboratory practice.
The Tat Inhibitor Didehydro-Cortistatin A Prevents HIV-1 Reactivation from Latency
Mousseau, Guillaume; Kessing, Cari F.; Fromentin, Rémi; Trautmann, Lydie; Chomont, Nicolas
2015-01-01
ABSTRACT Antiretroviral therapy (ART) inhibits HIV-1 replication, but the virus persists in latently infected resting memory CD4+ T cells susceptible to viral reactivation. The virus-encoded early gene product Tat activates transcription of the viral genome and promotes exponential viral production. Here we show that the Tat inhibitor didehydro-cortistatin A (dCA), unlike other antiretrovirals, reduces residual levels of viral transcription in several models of HIV latency, breaks the Tat-mediated transcriptional feedback loop, and establishes a nearly permanent state of latency, which greatly diminishes the capacity for virus reactivation. Importantly, treatment with dCA induces inactivation of viral transcription even after its removal, suggesting that the HIV promoter is epigenetically repressed. Critically, dCA inhibits viral reactivation upon CD3/CD28 or prostratin stimulation of latently infected CD4+ T cells from HIV-infected subjects receiving suppressive ART. Our results suggest that inclusion of a Tat inhibitor in current ART regimens may contribute to a functional HIV-1 cure by reducing low-level viremia and preventing viral reactivation from latent reservoirs. PMID:26152583
[Condition optimization for bio-oxidation of high-S and high-As gold concentrate].
Yang, Caiyun; Dong, Bowen; Wang, Meijun; Ye, Zhiyong; Zheng, Tianling; Huang, Huaiguo
2015-12-04
To study the effects of temperature and lixivium return on the concentrate bio-oxidation and rate of gold cyanide leaching. The bioleaching of a high-sulphur (S) and high-arsenic (As) refractory gold concentrate was conducted, and we studied the effects of different temperature (40 ° and 45 °C) and lixivium return (0 and 600 mL) on the bio-oxidation efficiency. The bacterial community structure also was investigated by 16S rRNA gene clone library. The results showed that both the temperature and lixivium return significantly influenced the oxidation system. The temperature rising elevated the oxidation level, while the addition of lixivium depressed the oxidation. Dissimilarity and DCA (detrended correspondence analysis) indicated the effect of temperature on oxidation system was much greater than lixivium. The bacterial community was comprised by Acidithiocacillus caldu (71%) Leptospirillum ferriphilum (23%) and Sulfobacillus thermosulfidooxidans (6%) indicated by the clone library, and the OTU coverage based on 97% sequence similarity was as high as 93.67%. Temperature rising to 45 T would improve the oxidation efficiency while lixivium return would decrease it. This study is helpful to provide an important guiding value for the industry cost optimization of mesophile bacterial oxidation and reduction process.
Abe, J; Deguchi, J; Takuwa, Y; Hara, K; Ikari, Y; Tamura, T; Ohno, M; Kurokawa, K
1998-01-01
Background—Growth factors such as platelet derived growth factor (PDGF) have been postulated to be important mediators of neointimal proliferation observed in atherosclerotic plaques and restenotic lesions following coronary interventions. Binding of PDGF to its receptor results in intrinsic receptor tyrosine kinase activation and subsequent cellular migration, proliferation, and vascular contraction. Aims—To investigate whether the concentration of PDGF β receptor tyrosine phosphorylation obtained from directional coronary atherectomy (DCA) samples correlate with atherosclerotic plaque burden, the ability of diseased vessels to remodel, coronary risk factors, and clinical events. Methods—DCA samples from 59 patients and 15 non-atherosclerotic left internal thoracic arteries (LITA) were analysed for PDGF β receptor tyrosine phosphorylation content by receptor immunoprecipitation and antiphosphotyrosine western blot. The amount of PDGF β receptor phosphorylation was analysed in relation to angiographic follow up data and clinical variables. Results—PDGF β receptor tyrosine phosphorylation in the 59 DCA samples was greater than in the 15 non-atherosclerotic LITA (mean (SD) 0.84 (0.67) v 0.17 (0.08) over a control standard, p < 0.0001). As evaluated by stepwise regression analysis, incorporation of both PDGF β receptor tyrosine phosphorylation and immediate gain correlated strongly (adjusted r2 = 0.579) with late loss, although PDGF β receptor tyramine phosphorylation alone correlated poorly with late loss. Multivariate regression analysis of coronary risk factors and clinical events revealed unstable angina as the most significant correlate of PDGF β receptor tyrosine phosphorylation (F value 20.009, p < 0.0001). Conclusions—PDGF β receptor tyrosine phosphorylation in atherosclerotic lesions is increased compared with non-atherosclerotic arterial tissues. The association of PDGF β receptor tyrosine phosphorylation with immediate gain strongly correlates with vascular remodelling. PDGF β receptor tyrosine phosphorylation correlates with unstable angina pectoris. Keywords: PDGF receptors; atherosclerosis; directional coronary atherectomy; restenosis PMID:9616351
Dominguez, G; Dagnas, M; Decorte, L; Vandesquille, M; Belzung, C; Béracochéa, D; Mons, N
2016-03-01
Both human and animal studies indicate that alcohol withdrawal following chronic alcohol consumption (CAC) impairs many of the cognitive functions which rely on the prefrontal cortex (PFC). A candidate signaling cascade contributing to memory deficits during alcohol withdrawal is the protein kinase A (PKA)/cAMP-responsive element binding (CREB) cascade, although the role of PKA/CREB cascade in behavioral and molecular changes during sustained withdrawal period remains largely unknown. We demonstrated that 1 week (1W) or 6 weeks (6W) withdrawal after 6-month CAC impairs working memory (WM) in a T-maze spontaneous alternation task and reduces phosphorylated CREB (pCREB) in the PFC but not the dorsal CA1 region (dCA1) of the hippocampus compared with CAC and water conditions. In contrast, both CAC-unimpaired and withdrawn-impaired mice exhibited decreased pCREB in dCA1 as well as reduced histone H4 acetylation in PFC and dCA1, compared with water controls. Next, we showed that enhancing CREB activity through rolipram administration prior to testing improved WM performance in withdrawn mice but impaired WM function in water mice. In addition, WM improvement correlates positively with increased pCREB level selectively in the PFC of withdrawn mice. Results further indicate that direct infusion of the PKA activator (Sp-cAMPS) into the PFC significantly improves or impairs, respectively, WM performance in withdrawn and water animals. In contrast, Sp-cAMPS had no effect on WM when infused into the dCA1. Collectively, these results provide strong support that dysregulation of PKA/CREB-dependent processes in prefrontal neurons is a critical molecular signature underlying cognitive decline during alcohol withdrawal.
Hemoglobin A1c Point-of-Care Assays; a New World with a Lot of Consequences!
Lenters-Westra, Erna; Slingerland, Robbert J.
2009-01-01
Background Point-of-care instruments for the measurement of hemoglobin A1c (HbA1c) may improve the glycemic control of people with diabetes by providing a rapid result if the performance of the instruments used is acceptable. A 0.5% HbA1c difference between successive results is considered a clinically relevant change. With this in mind, the In2it from Bio-Rad and the DCA Vantage from Siemens were evaluated according to Clinical and Laboratory Standards Institute (CLSI) protocols. Methods The CLSI protocols EP-5 and EP-9 were applied to investigate precision, accuracy, and bias. The bias was compared with three certified secondary reference measurement procedures. Differences between capillary and venous blood were investigated by an end-user group consisting of nurse practitioners at a diabetes care center. Results At HbA1c levels of 5.1 and 11.2%, total coefficients of variation (CV) for the In2it were 4.9 and 3.3%, respectively, and for the DCA Vantage were 1.7 to 1.8% and 3.7 to 5.5% depending on the lot number of the cartridges. Method comparisons showed significant lot number-dependent results for the In2it and the DCA Vantage compared with the three reference methods. No overall difference was observed between capillary and venous blood for both methods. Conclusion Performance results of the In2it and the DCA Vantage showed variable and lot number-dependent results. To maintain the interlaboratory CV of 5% for HbA1c, the Clinical Laboratory Improvement Amendments rules for waived point-of-care instruments should be revised. An obligation for participating in external quality schemes and taking adequate action should be considered for POC instruments that perform poorly. PMID:20144277
Mars Global Digital Dune Database (MGD3): Global dune distribution and wind pattern observations
Hayward, Rosalyn K.; Fenton, Lori; Titus, Timothy N.
2014-01-01
The Mars Global Digital Dune Database (MGD3) is complete and now extends from 90°N to 90°S latitude. The recently released south pole (SP) portion (MC-30) of MGD3 adds ∼60,000 km2 of medium to large-size dark dune fields and ∼15,000 km2 of sand deposits and smaller dune fields to the previously released equatorial (EQ, ∼70,000 km2), and north pole (NP, ∼845,000 km2) portions of the database, bringing the global total to ∼975,000 km2. Nearly all NP dunes are part of large sand seas, while the majority of EQ and SP dune fields are individual dune fields located in craters. Despite the differences between Mars and Earth, their dune and dune field morphologies are strikingly similar. Bullseye dune fields, named for their concentric ring pattern, are the exception, possibly owing their distinctive appearance to winds that are unique to the crater environment. Ground-based wind directions are derived from slipface (SF) orientation and dune centroid azimuth (DCA), a measure of the relative location of a dune field inside a crater. SF and DCA often preserve evidence of different wind directions, suggesting the importance of local, topographically influenced winds. In general however, ground-based wind directions are broadly consistent with expected global patterns, such as polar easterlies. Intriguingly, between 40°S and 80°S latitude both SF and DCA preserve their strongest, though different, dominant wind direction, with transport toward the west and east for SF-derived winds and toward the north and west for DCA-derived winds.
NASA Astrophysics Data System (ADS)
Drozd, G.; Woo, J.; Häkkinen, S. A. K.; Nenes, A.; McNeill, V. F.
2014-05-01
Volatility and hygroscopicity are two key properties of organic aerosol components, and both are strongly related to chemical identity. While the hygroscopicities of pure salts, di-carboxylic acids (DCA), and DCA salts are known, the hygroscopicity of internal mixtures of these components, as they are typically found in the atmosphere, has not been fully characterized. Here we show that inorganic-organic component interactions typically not considered in atmospheric models can lead to very strongly bound metal-organic complexes and greatly affect aerosol volatility and hygroscopicity; in particular, the bi-dentate binding of DCA to soluble inorganic ions. We have studied the volatility of pure, dry organic salt particles and the hygroscopicity of internal mixtures of oxalic acid (OxA, the dominant DCA in the atmosphere) and a number of salts, both mono- and di-valent. The formation of very low volatility organic salts was confirmed, with minimal evaporation of oxalate salt particles below 75 °C. Dramatic increases in the cloud condensation nuclei (CCN) activation diameter for particles with di-valent salts (e.g., CaCl2) and relatively small particle volume fractions of OxA indicate that standard volume additivity rules for hygroscopicity do not apply. Thus small organic compounds with high O : C ratios are capable of forming low-volatility and very low hygroscopicity particles. Given current knowledge of the formation mechanisms of OxA and M-Ox salts, surface enrichment of insoluble M-Ox salts is expected. The resulting formation of an insoluble coating of metal-oxalate salts can explain low-particle hygroscopicities. The formation of particles with a hard coating could offer an alternative explanation for observations of glass-like particles without the need for a phase transition.
Li, Ling; Sun, Han; Kitazawa, Hiroaki; Wang, Xiangyou
2017-07-01
Browning is one of the main problems in senescence of mushrooms, and it is also one of the most important attributes accounting for the loss of the quality and reduction in market value. In order to study the relationship between the energy metabolism and the browning of white mushroom under high O 2 dynamic-controlled atmosphere (HO-DCA), mushrooms were stored in 100% O 2 (SCA1), 80% O 2 + 20% CO 2 (SCA2), 100% O 2 for three days and then transferred into the treatment of 80% O 2 + 20% CO 2 (HO-DCA) at 2 ± 1 ℃ and air as control. In this study, adenosine triphosphate (ATP) content, energy charge level, sensory evaluation, browning of surface and flesh, cell membrane integrity, exogenous ATP, polyphenol oxidase (PPO) and peroxidase (POD) activity and genes encoding PPO of the white mushroom were investigated. These were all closely related to the browning of products. The optimal storage condition of the HO-DCA treatment could delay the browning of pericarp and flesh tissues of the mushrooms, inhibit PPO activity and reduce the relative expression levels of the three genes encoding PPO. Meanwhile, it maintained moderate POD activity, good sensory properties and cell membrane integrity in a certain extent and thus slowed down the senescence of mushrooms. Results indicated that there was a positive correlation between the ATP content and whitening index ( r = 0.901). In addition, HO-DCA maintained a higher ATP level, prolonged the storage time to 28 days and it might be an ideal strategy for preserving the quality of mushroom during storage.
Beneficial effect of pyruvate therapy on Leigh syndrome due to a novel mutation in PDH E1α gene.
Koga, Yasutoshi; Povalko, Nataliya; Katayama, Koujyu; Kakimoto, Noriko; Matsuishi, Toyojiro; Naito, Etsuo; Tanaka, Masashi
2012-02-01
Leigh syndrome (LS) is a progressive untreatable degenerating mitochondrial disorder caused by either mitochondrial or nuclear DNA mutations. A patient was a second child of unconsanguineous parents. On the third day of birth, he was transferred to neonatal intensive care units because of severe lactic acidosis. Since he was showing continuous lactic acidosis, the oral supplementation of dichloroacetate (DCA) was introduced on 31st day of birth at initial dose of 50 mg/kg, followed by maintenance dose of 25 mg/kg/every 12 h. The patient was diagnosed with LS due to a point mutation of an A-C at nucleotide 599 in exon 6 in the pyruvate dehydrogenase E1α gene, resulting in the substitution of aspartate for threonine at position 200 (N200T). Although the concentrations of lactate and pyruvate in blood were slightly decreased, his clinical conditions were deteriorating progressively. In order to overcome the mitochondrial or cytosolic energy crisis indicated by lactic acidosis as well as clinical symptoms, we terminated the DCA and administered 0.5 g/kg/day TID of sodium pyruvate orally. We analyzed the therapeutic effects of DCA or sodium pyruvate in the patient, and found that pyruvate therapy significantly decreased lactate, pyruvate and alanine levels, showed no adverse effects such as severe neuropathy seen in DCA, and had better clinical response on development and epilepsy. Though the efficacy of pyruvate on LS will be evaluated by randomized double-blind placebo-controlled study design in future, pyruvate therapy is a possible candidate for therapeutic choice for currently incurable mitochondrial disorders such as LS. Copyright © 2011 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.
Nour, Eman H; Elsayed, Tarek R; Springael, Dirk; Smalla, Kornelia
2017-06-01
On-farm biopurification systems (BPSs) represent an efficient technology for treating pesticide-contaminated wastewater. Biodegradation by genetically adapted bacteria has been suggested to perform a major contribution to the removal of pesticides in BPSs. Recently, several studies pointed to the role of IncP-1 plasmids in the degradation of pesticides in BPSs but this was never linked with catabolic markers. Therefore, a microcosm experiment was conducted in order to examine whether changes in mobile genetic element (MGE) abundances in response to the application of phenylurea herbicide linuron are linked with changes in catabolic genes. Denaturing gradient gel electrophoresis (DGGE) fingerprints of 16S ribosomal RNA gene fragments amplified from total community (TC)-DNA suggested significant shifts in the bacterial community composition. PCR-Southern blot-based detection of genes involved in linuron hydrolysis (libA and hylA) or degradation of its metabolite 3,4-dichloroaniline (dcaQ I , dcaQ II , and ccdC) in TC-DNA showed that the abundance of the hylA gene was increased faster and stronger in response to linuron application than that of the libA gene, and that the dcaQ II gene was more abundant than the isofunctional gene dcaQ I 20 and 60 days after linuron addition. Furthermore, a significant increase in the relative abundance of the IncP-1-specific korB gene in response to linuron was recorded. Our data suggest that different bacterial populations bearing isofunctional genes coding for enzymes degrading linuron seemed to be enriched in BPSs in response to linuron and that IncP-1 plasmids might be involved in their dissemination.
Knowledge-Based System Analysis and Control Defense Switched Network Task Areas
1989-09-30
to produce the various kinds of real-world DSN behavior noted above. We needed to make changes in the internal labelling of trunk groups ; the form...for both the NMES demo and the NMSS Controller Trainer, which became a closely related activity because the Trainer would be used to provide inputs...Other rules would then fi-e to remove the related controls. Independent of any considerations relative to a demonstration at DCA-Europe, there was a
Lu, Qiang; Luo, Qi Shi; Li, Hui; Liu, Yong Di; Gu, Ji Dong; Lin, Kuang Fei; Fei Lin, Kuang
2015-01-01
CAHs, as a cleaning solvent, widely contaminated shallow groundwater with the development of manufacturing in China's Yangtze River Delta. This study focused on the distribution of CAHs, and correlations between CAHs and environmental variables in a shallow groundwater in Shanghai, using kriging interpolation and multifactorial analysis. The results showed that the overall CAHs plume area (above DIV) was approximately 9,000 m(2) and located in the 2-4 m underground, DNAPL was accumulated at an area of approximately 1,400 m(2) and located in the 6-8m sandy silt layer on the top of the muddy silty clay. Heatmap of PPC for CAHs and environmental variables showed that the correlation between "Fe(2+)" and most CAHs such as "1,1,1-TCA", "1,1-DCA", "1,1-DCE" and "%TCA" were significantly positive (p<0.001), but "%CA" and/or "%VC" was not, and "Cl-" was significantly positive correlated with "1,1-DCA" and "1,1-DCE" (p<0.001). The PCA demonstrated that the relative proportions of CAHs in groundwater were mostly controlled by the sources and the natural attenuation. In conclusion, the combination of geographical and chemometrics was helpful to establishing an aerial perspective of CAHs and identifying reasons for the accumulation of toxic dechlorination intermediates, and could become a useful tool for characterizing contaminated sites in general.
Effect of Intracranial Stenosis Revascularization on Dynamic and Static Cerebral Autoregulation.
Ortega-Gutierrez, Santiago; Samaniego, Edgar A; Huang, Amy; Masurkar, Arjun; Zheng-Lin, Binbin; Derdeyn, Colin P; Hasan, David; Marshall, Randolph; Petersen, Nils
2018-06-01
Severe intracranial stenosis might lead to acute cerebral ischemia. It is imperative to better assess patients who may benefit from immediate reperfusion and blood pressure management to prevent injury to peri-infarct tissue. We assessed cerebral autoregulation using static and dynamic methods in an 81-year-old woman suffering acute cerebral ischemia from severe intracranial stenosis in the petrous segment of the left internal carotid artery (LICA). Static cerebral autoregulation, which is evaluated by magnetic resonance imaging and magnetic resonance perfusion studies showed a progression of infarcts and a large perfusion-diffusion mismatch in the entire LICA territory between the second and third days after onset despite maximized medical therapy. Dynamic methods, including transfer function analysis and mean velocity index, demonstrated an increasingly impaired dynamic cerebral autoregulation (DCA) on the affected side between these days. Revascularization through acute intracranial stenting resulted in improved perfusion in the LICA territory and normalization of both dynamic and static cerebral autoregulation. Thus, DCA, a noninvasive bedside method, may be useful in helping to identify and select patients with large-vessel flow-failure syndromes that would benefit from immediate revascularization of intracranial atherosclerotic disease.
Meador, M.R.; Coles, J.F.; Zappia, H.
2005-01-01
We examined fish assemblage responses to urban intensify gradients in two contrasting metropolitan areas: Birmingham, Alabama (BIR) and Boston, Massachusetts (BOS). Urbanization was quantified by using an urban intensity index (UII) that included multiple stream buffers and basin land uses, human population density, and road density variables. We evaluated fish assemblage responses by using species richness metrics and detrended correspondence analyses (DCA). Fish species richness metrics included total fish species richness, and percentages of endemic species richness, alien species, and fluvial specialist species. Fish species richness decreased significantly with increasing urbanization in BIR (r = -0.82, P = 0.001) and BOS (r = -0.48, P = 0.008). Percentages of endemic species richness decreased significantly with increasing urbanization only in BIR (r = - 0.71, P = 0.001), whereas percentages of fluvial specialist species decreased significantly with increasing urbanization only in BOS (r = -0.56, P = 0.002). Our DCA results for BIR indicate that highly urbanized fish assemblages are composed primarily of largescale stoneroller Campostoma oligolepis, largemouth bass Micropterus salmoides, and creek chub Semotilus atromaculatus, whereas the highly urbanized fish assemblages in BOS are dominated by yellow perch Perca flavescens, bluegill Lefomis macrochirus, yellow bullhead Ameiurus natalis, largemouth bass, pumpkinseed L. gibbosus, brown bullhead A. nebulosus, and redfin pickerel Esox americanus. Differences in fish assemblage responses to urbanization between the two areas appear to be related to differences in nutrient enrichment, habitat alterations, and invasive species. Because species richness can increase or decrease with increasing urbanization, a general response model is not applicable. Instead, response models based on species' life histories, behavior, and autecologies offer greater potential for understanding fish assemblage responses to urbanization. ?? 2005 by the American Fisheries Society.
Block clustering based on difference of convex functions (DC) programming and DC algorithms.
Le, Hoai Minh; Le Thi, Hoai An; Dinh, Tao Pham; Huynh, Van Ngai
2013-10-01
We investigate difference of convex functions (DC) programming and the DC algorithm (DCA) to solve the block clustering problem in the continuous framework, which traditionally requires solving a hard combinatorial optimization problem. DC reformulation techniques and exact penalty in DC programming are developed to build an appropriate equivalent DC program of the block clustering problem. They lead to an elegant and explicit DCA scheme for the resulting DC program. Computational experiments show the robustness and efficiency of the proposed algorithm and its superiority over standard algorithms such as two-mode K-means, two-mode fuzzy clustering, and block classification EM.
Zhang, Guilian; Zhang, Jintun; Guo, Xiaoyu
2005-01-01
By the methods of TWINSPAN, DCA and DCCA, and from the aspects of the relations between plant species, communities and environmental factors, this paper studied the ecological relationships among artificial vegetations during their restoration in Antaibao mining area. 63 collected quadrates were classified into 12 community types by TWINSPAN, and the distribution of the communities could comprehensively reflect the influence of environmental factors. DCA ordination indicated that soil water content, which was increased with restoration time, was the main factor restricting the distribution of the communities. DCCA ordination showed that soil organic matter content was the decisive factor to the development of communities.
Xing, Yingshou; Chen, Wenxi; Wang, Yanran; Jing, Wei; Gao, Shan; Guo, Daqing; Xia, Yang; Yao, Dezhong
2016-03-01
Previous research has shown that dorsal hippocampus plays an important role in spatial memory process. Music exposure can enhance brain-derived neurotrophic factor (BDNF) expression level in dorsal hippocampus (DH) and thus enhance spatial cognition ability. But whether music experience may affect different subregions of DH in the same degree remains unclear. Here, we studied the effects of exposure to Mozart K.448 on learning behavior in developing rats using the classical Morris water maze task. The results showed that early music exposure could enhance significantly learning performance of the rats in the water maze test. Meanwhile, the BDNF/TrkB level of dorsal hippocampus CA3 (dCA3) and dentate gyrus (dDG) was significantly enhanced in rats exposed to Mozart music as compared to those without music exposure. In contrast, the BDNF/TrkB level of dorsal hippocampus CA1 (dCA1) was not affected. The results suggest that the spatial memory improvement by music exposure in rats may be associated with the enhanced BDNF/TrkB level of dCA3 and dDG. Copyright © 2016 Elsevier Inc. All rights reserved.
Dirac Cellular Automaton from Split-step Quantum Walk
Mallick, Arindam; Chandrashekar, C. M.
2016-01-01
Simulations of one quantum system by an other has an implication in realization of quantum machine that can imitate any quantum system and solve problems that are not accessible to classical computers. One of the approach to engineer quantum simulations is to discretize the space-time degree of freedom in quantum dynamics and define the quantum cellular automata (QCA), a local unitary update rule on a lattice. Different models of QCA are constructed using set of conditions which are not unique and are not always in implementable configuration on any other system. Dirac Cellular Automata (DCA) is one such model constructed for Dirac Hamiltonian (DH) in free quantum field theory. Here, starting from a split-step discrete-time quantum walk (QW) which is uniquely defined for experimental implementation, we recover the DCA along with all the fine oscillations in position space and bridge the missing connection between DH-DCA-QW. We will present the contribution of the parameters resulting in the fine oscillations on the Zitterbewegung frequency and entanglement. The tuneability of the evolution parameters demonstrated in experimental implementation of QW will establish it as an efficient tool to design quantum simulator and approach quantum field theory from principles of quantum information theory. PMID:27184159
De Preter, Géraldine; Neveu, Marie-Aline; Danhier, Pierre; Brisson, Lucie; Payen, Valéry L; Porporato, Paolo E; Jordan, Bénédicte F; Sonveaux, Pierre; Gallez, Bernard
2016-01-19
Glucose fermentation through glycolysis even in the presence of oxygen (Warburg effect) is a common feature of cancer cells increasingly considered as an enticing target in clinical development. This study aimed to analyze the link between metabolism, energy stores and proliferation rates in cancer cells. We found that cell proliferation, evaluated by DNA synthesis quantification, is correlated to glycolytic efficiency in six cancer cell lines as well as in isogenic cancer cell lines. To further investigate the link between glycolysis and proliferation, a pharmacological inhibitor of the pentose phosphate pathway (PPP) was used. We demonstrated that reduction of PPP activity decreases cancer cells proliferation, with a profound effect in Warburg-phenotype cancer cells. The crucial role of the PPP in sustaining cancer cells proliferation was confirmed using siRNAs against glucose-6-phosphate dehydrogenase, the first and rate-limiting enzyme of the PPP. In addition, we found that dichloroacetate (DCA), a new clinically tested compound, induced a switch of glycolytic cancer cells to a more oxidative phenotype and decreased proliferation. By demonstrating that DCA decreased the activity of the PPP, we provide a new mechanism by which DCA controls cancer cells proliferation.
NASA Astrophysics Data System (ADS)
Pendota, Premchand
Many physical phenomena and industrial applications involve multiphase fluid flows and hence it is of high importance to be able to simulate various aspects of these flows accurately. The Dynamic Contact Angles (DCA) and the contact lines at the wall boundaries are a couple of such important aspects. In the past few decades, many mathematical models were developed for predicting the contact angles of the inter-face with the wall boundary under various flow conditions. These models are used to incorporate the physics of DCA and contact line motion in numerical simulations using various interface capturing/tracking techniques. In the current thesis, a simple approach to incorporate the static and dynamic contact angle boundary conditions using the level set method is developed and implemented in multiphase CFD codes, LIT (Level set Interface Tracking) (Herrmann (2008)) and NGA (flow solver) (Desjardins et al (2008)). Various DCA models and associated boundary conditions are reviewed. In addition, numerical aspects such as the occurrence of a stress singularity at the contact lines and grid convergence of macroscopic interface shape are dealt with in the context of the level set approach.
Ang, Hooi-Hoon; Lee, Ee-Lin; Cheang, Hui-Seong
2004-01-01
The DCA (Drug Control Authority), Malaysia, has implemented the phase 3 registration of traditional medicines on 1 January 1992, with special emphasis on the quality, efficacy, and safety (including the presence of heavy metals) in all pharmaceutical dosage forms of traditional medicine preparations. As such, a total of 100 products in various pharmaceutical dosage forms of a herbal preparation, containing Tongkat Ali, were analyzed for mercury content using cold vapor atomic absorption spectrophotometer. Results showed that 36% of the above products possessed 0.52 to 5.30 ppm of mercury and, therefore, do not comply with the quality requirement for traditional medicines in Malaysia. Out of these 36 products, 5 products that possessed 1.05 to 4.41 ppm of mercury were in fact have already registered with the DCA, Malaysia. However, the rest of the products that contain 0.52 to 5.30 ppm of mercury still have not registered with the DCA, Malaysia. Although this study showed that only 64% of the products complied with the quality requirement for traditional medicines in Malaysia pertaining to mercury, they cannot be assumed safe from mercury contamination because of batch-to-batch inconsistency.
In vivo voltammetry: from wire to wireless measurements.
Crespi, Francesco; Dalessandro, Davide; Annovazzi-Lodi, Valerio; Heidbreder, Christian; Norgia, Michele
2004-12-30
A novel telemetric system based on either differential pulse voltammetry (DPV) or direct current amperometry (DCA) by using a diffused infrared transmission channel is presented. Unlike similar pre-existing instruments based on infrared transmission, the present system works on a single-way communication, thus avoiding problems related to cross-talking between two-way channels. The infrared channel is also immune from electromagnetic interferences from the surrounding environment. Further advancement is the development of an original miniaturised system (dimension 1cm x 1.2 cm x 0.5 cm) with reduced weight (5-6 g), suitable for affixing to the rat head and allowing real time telemetric monitoring using DCA sampling of neurotransmitters such as dopamine or serotonin every 100 ms. The set-up is based on a transmitter (TX) circuit mounted on the animal's head and connected to the electrodes inserted into its brain. The TX circuit generates the proper electrical signals for DPV or DCA, collects the electrical response of the brain and transmits it, via an infrared channel, to a receiving station (RX) interfaced with a personal computer. The PC performs the sampling and elaboration of polarographic traces in a flexible and programmable way.
MISTIC2: comprehensive server to study coevolution in protein families.
Colell, Eloy A; Iserte, Javier A; Simonetti, Franco L; Marino-Buslje, Cristina
2018-06-14
Correlated mutations between residue pairs in evolutionarily related proteins arise from constraints needed to maintain a functional and stable protein. Identifying these inter-related positions narrows down the search for structurally or functionally important sites. MISTIC is a server designed to assist users to calculate covariation in protein families and provide them with an interactive tool to visualize the results. Here, we present MISTIC2, an update to the previous server, that allows to calculate four covariation methods (MIp, mfDCA, plmDCA and gaussianDCA). The results visualization framework has been reworked for improved performance, compatibility and user experience. It includes a circos representation of the information contained in the alignment, an interactive covariation network, a 3D structure viewer and a sequence logo. Others components provide additional information such as residue annotations, a roc curve for assessing contact prediction, data tables and different ways of filtering the data and exporting figures. Comparison of different methods is easily done and scores combination is also possible. A newly implemented web service allows users to access MISTIC2 programmatically using an API to calculate covariation and retrieve results. MISTIC2 is available at: https://mistic2.leloir.org.ar.
Campbell, Jerry L.; Clewell, Harvey J.; Zhou, Yi-Hui; Wright, Fred A.; Guyton, Kathryn Z.
2014-01-01
Background: Quantitative estimation of toxicokinetic variability in the human population is a persistent challenge in risk assessment of environmental chemicals. Traditionally, interindividual differences in the population are accounted for by default assumptions or, in rare cases, are based on human toxicokinetic data. Objectives: We evaluated the utility of genetically diverse mouse strains for estimating toxicokinetic population variability for risk assessment, using trichloroethylene (TCE) metabolism as a case study. Methods: We used data on oxidative and glutathione conjugation metabolism of TCE in 16 inbred and 1 hybrid mouse strains to calibrate and extend existing physiologically based pharmacokinetic (PBPK) models. We added one-compartment models for glutathione metabolites and a two-compartment model for dichloroacetic acid (DCA). We used a Bayesian population analysis of interstrain variability to quantify variability in TCE metabolism. Results: Concentration–time profiles for TCE metabolism to oxidative and glutathione conjugation metabolites varied across strains. Median predictions for the metabolic flux through oxidation were less variable (5-fold range) than that through glutathione conjugation (10-fold range). For oxidative metabolites, median predictions of trichloroacetic acid production were less variable (2-fold range) than DCA production (5-fold range), although the uncertainty bounds for DCA exceeded the predicted variability. Conclusions: Population PBPK modeling of genetically diverse mouse strains can provide useful quantitative estimates of toxicokinetic population variability. When extrapolated to lower doses more relevant to environmental exposures, mouse population-derived variability estimates for TCE metabolism closely matched population variability estimates previously derived from human toxicokinetic studies with TCE, highlighting the utility of mouse interstrain metabolism studies for addressing toxicokinetic variability. Citation: Chiu WA, Campbell JL Jr, Clewell HJ III, Zhou YH, Wright FA, Guyton KZ, Rusyn I. 2014. Physiologically based pharmacokinetic (PBPK) modeling of interstrain variability in trichloroethylene metabolism in the mouse. Environ Health Perspect 122:456–463; http://dx.doi.org/10.1289/ehp.1307623 PMID:24518055
Bers, Karolien; Leroy, Baptiste; Breugelmans, Philip; Albers, Pieter; Lavigne, Rob; Sørensen, Sebastian R.; Aamand, Jens; De Mot, René; Wattiez, Ruddy; Springael, Dirk
2011-01-01
The soil bacterial isolate Variovorax sp. strain SRS16 mineralizes the phenylurea herbicide linuron. The proposed pathway initiates with hydrolysis of linuron to 3,4-dichloroaniline (DCA) and N,O-dimethylhydroxylamine, followed by conversion of DCA to Krebs cycle intermediates. Differential proteomic analysis showed a linuron-dependent upregulation of several enzymes that fit into this pathway, including an amidase (LibA), a multicomponent chloroaniline dioxygenase, and enzymes associated with a modified chlorocatechol ortho-cleavage pathway. Purified LibA is a monomeric linuron hydrolase of ∼55 kDa with a Km and a Vmax for linuron of 5.8 μM and 0.16 nmol min−1, respectively. This novel member of the amidase signature family is unrelated to phenylurea-hydrolyzing enzymes from Gram-positive bacteria and lacks activity toward other tested phenylurea herbicides. Orthologues of libA are present in all other tested linuron-degrading Variovorax strains with the exception of Variovorax strains WDL1 and PBS-H4, suggesting divergent evolution of the linuron catabolic pathway in different Variovorax strains. The organization of the linuron degradation genes identified in the draft SRS16 genome sequence indicates that gene patchwork assembly is at the origin of the pathway. Transcription analysis suggests that a catabolic intermediate, rather than linuron itself, acts as effector in activation of the pathway. Our study provides the first report on the genetic organization of a bacterial pathway for complete mineralization of a phenylurea herbicide and the first report on a linuron hydrolase in Gram-negative bacteria. PMID:22003008
NASA Astrophysics Data System (ADS)
Zhang, Fan; Lin, Qiu-Yue; Li, Shi-Kun; Zhao, Yu-Ling; Wang, Peng-Peng; Chen, Miao-Miao
2012-12-01
Four new transition metal complexes (Habtz)2[M(DCA)2]·6H2O (M = Co(II) (1), Ni(II) (2), Cu(II) (3), Zn(II) (4); DCA = demethylcantharate, 7-oxabicyclo [2.2.1]heptane-2,3-dicarboxylate, C8H8O5; Habtz = 2-aminobenzothiazole acid, C7H7N2S) were synthesized and characterized by elemental analysis, molar conductance, infrared spectra and thermogravimetric analysis. The coordination number of complex was six. The X-ray diffraction analysis indicated that complex 3 crystallized in the triclinic crystal system with P1¯ space group. The DNA-binding properties of the complexes were investigated by electronic absorption spectra, fluorescence spectra, viscosity measurements. Title complexes could bind to DNA via partial intercalative mode. The Kb of the complexes were 5.33 × 104 (1), 7.04 × 104 (2), 9.91 × 104 (3) and 5.03 × 104 L mol-1 (4). The results of agarose gel electrophoresis showed that Cu(II) complex could cleave pBR322 plasmid DNA via radical-based mechanism. The complexes could quench the intrinsic fluorescence of bovine serum albumin (BSA) through a static quenching with the binding constants Ka of 1.11 × 104 (1), 1.24 × 106 (2), 8.42 × 105 (3) and 1.75 × 104 L mol-1 (4). The complexes had intense antiproliferative activities against human hepatoma cell lines (SMMC7721) and human gastric cancer cells (MGC80-3) lines in vitro. Cu(II) complex had the strongest activity against human gastric cancer cells.
Determination of lead in Smilax myosotiflora herbal preparations obtained in Malaysia.
Ang, H H; Lee, K L; Kiyoshi, M
2004-08-01
The DCA (Drug Control Authority), Malaysia implemented the phase 3 registration of traditional medicines on 1 January 1992 with special emphasis on the quality, efficacy and safety (including the presence of heavy metals) in all pharmaceutical dosage forms of traditional medicinal preparations. As such, a total of 100 traditional medicinal preparations, containing Smilax myosotiflora, in various pharmaceutical dosage forms, which were bought in the Malaysian market, were analysed for lead content using atomic absorption spectrophotometry. Results showed that 15% of the products analysed possessed 10.23-23.05 ppm of lead, and therefore, do not comply with the quality requirement for traditional medicines in Malaysia. The quality requirement for traditional medicines in Malaysia is that they should not exceed 10 ppm of lead. Out of these 15 products, five products exhibited 10.23-23.05 ppm of lead, in fact they have already been registered with the DCA Malaysia. However, the rest of the products, which possessed 12.24-20.72 ppm of lead, have still not been registered with the DCA Malaysia. Although this study successfully showed that only 85% of the products complied with the quality requirement for traditional medicines in Malaysia pertaining to lead, they cannot, however, be assumed to be safe from lead contamination because of batch-to-batch inconsistency.
Comparison of Established and Emerging Biodosimetry Assays
Rothkamm, K.; Beinke, C.; Romm, H.; Badie, C.; Balagurunathan, Y.; Barnard, S.; Bernard, N.; Boulay-Greene, H.; Brengues, M.; De Amicis, A.; De Sanctis, S.; Greither, R.; Herodin, F.; Jones, A.; Kabacik, S.; Knie, T.; Kulka, U.; Lista, F.; Martigne, P.; Missel, A.; Moquet, J.; Oestreicher, U.; Peinnequin, A.; Poyot, T.; Roessler, U.; Scherthan, H.; Terbrueggen, B.; Thierens, H.; Valente, M.; Vral, A.; Zenhausern, F.; Meineke, V.; Braselmann, H.; Abend, M.
2014-01-01
Rapid biodosimetry tools are required to assist with triage in the case of a large-scale radiation incident. Here, we aimed to determine the dose-assessment accuracy of the well-established dicentric chromosome assay (DCA) and cytokinesis-block micronucleus assay (CBMN) in comparison to the emerging γ-H2AX foci and gene expression assays for triage mode biodosimetry and radiation injury assessment. Coded blood samples exposed to 10 X-ray doses (240 kVp, 1 Gy/min) of up to 6.4 Gy were sent to participants for dose estimation. Report times were documented for each laboratory and assay. The mean absolute difference (MAD) of estimated doses relative to the true doses was calculated. We also merged doses into binary dose categories of clinical relevance and examined accuracy, sensitivity and specificity of the assays. Dose estimates were reported by the first laboratories within 0.3–0.4 days of receipt of samples for the γ-H2AX and gene expression assays compared to 2.4 and 4 days for the DCA and CBMN assays, respectively. Irrespective of the assay we found a 2.5–4-fold variation of interlaboratory accuracy per assay and lowest MAD values for the DCA assay (0.16 Gy) followed by CBMN (0.34 Gy), gene expression (0.34 Gy) and γ-H2AX (0.45 Gy) foci assay. Binary categories of dose estimates could be discriminated with equal efficiency for all assays, but at doses ≥1.5 Gy a 10% decrease in efficiency was observed for the foci assay, which was still comparable to the CBMN assay. In conclusion, the DCA has been confirmed as the gold standard biodosimetry method, but in situations where speed and throughput are more important than ultimate accuracy, the emerging rapid molecular assays have the potential to become useful triage tools. PMID:23862692
Zhang, Shao-Hui; Miao, Dong-Yue; Tan, Li; Liu, Ai-Lin; Lu, Wen-Qing
2016-01-01
The implications of disinfection by-products (DBPs) present in drinking water are of public health concern because of their potential mutagenic, carcinogenic and other toxic effects on humans. In this study, we selected 13 main DBPs found in drinking water to quantitatively analyse their cytotoxicity and genotoxicity using a microplate-based cytotoxicity assay and a developed SOS/umu assay in Salmonella typhimurium TA1535/pSK1002. With the developed SOS/umu test, eight DBPs: 3-chloro-4-(dichloromethyl)-5-hydroxy-2[5H]-fura3-chloro-4-(dichloromethyl)-5-hydroxy-2-[5H]-furanone (MX), dibromoacetonitrile (DBN), iodoacetic acid (IA), bromochloroacetonitrile (BCN), bromoacetic acid (BA), trichloroacetonitrile (TCN), dibromoacetic acid (DBA) and dichloroacetic acid (DCA) were significantly genotoxic to S. typhimurium. Three DBPs: chloroacetic acid (CA), trichloroacetic acid (TCA) and dichloroacetonitrile (DCN) were weakly genotoxic, whereas the remaining DBPs: chloroacetonitrile (CN) and chloral hydrate (CH) were negative. The rank order in decreasing genotoxicity was as follows: MX > DBN > IA > BCN > BA > TCN > DBA > DCA > CA, TCA, DCN > CN, CH. MX was approximately 370 000 times more genotoxic than DCA. In the microplate-based cytotoxicity assay, cytotoxic potencies of the 13 DBPs were compared and ranked in decreasing order as follows: MX > IA > DBN > BCN > BA > TCN > DCN > CA > DCA > DBA > CN > TCA > CH. MX was approximately 19 200 times more cytotoxic than CH. A statistically significant correlation was found between cytotoxicity and genotoxicity of the 13 DBPs in S. typhimurium. Results suggest that microplate-based cytotoxicity assay and the developed SOS/umu assay are feasible tools for analysing the cytotoxicity and genotoxicity of DBPs, particularly for comparing their toxic intensities quantitatively. © The Author 2015. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
SU-D-BRB-01: A Predictive Planning Tool for Stereotactic Radiosurgery
DOE Office of Scientific and Technical Information (OSTI.GOV)
Palefsky, S; Roper, J; Elder, E
Purpose: To demonstrate the feasibility of a predictive planning tool which provides SRS planning guidance based on simple patient anatomical properties: PTV size, PTV shape and distance from critical structures. Methods: Ten framed SRS cases treated at Winship Cancer Institute of Emory University were analyzed to extract data on PTV size, sphericity (shape), and distance from critical structures such as the brainstem and optic chiasm. The cases consisted of five pairs. Each pair consisted of two cases with a similar diagnosis (such as pituitary adenoma or arteriovenous malformation) that were treated with different techniques: DCA, or IMRS. A Naive Bayesmore » Classifier was trained on this data to establish the conditions under which each treatment modality was used. This model was validated by classifying ten other randomly-selected cases into DCA or IMRS classes, calculating the probability of each technique, and comparing results to the treated technique. Results: Of the ten cases used to validate the model, nine had their technique predicted correctly. The three cases treated with IMRS were all identified as such. Their probabilities of being treated with IMRS ranged between 59% and 100%. Six of the seven cases treated with DCA were correctly classified. These probabilities ranged between 51% and 95%. One case treated with DCA was incorrectly predicted to be an IMRS plan. The model’s confidence in this case was 91%. Conclusion: These findings indicate that a predictive planning tool based on simple patient anatomical properties can predict the SRS technique used for treatment. The algorithm operated with 90% accuracy. With further validation on larger patient populations, this tool may be used clinically to guide planners in choosing an appropriate treatment technique. The prediction algorithm could also be adapted to guide selection of treatment parameters such as treatment modality and number of fields for radiotherapy across anatomical sites.« less
Biliary Bile Acids in Primary Biliary Cirrhosis: Effect of Ursodeoxycholic Acid
Combes, Burton; Carithers, Robert L.; Maddrey, Willis C.; Munoz, Santiago; Garcia-Tsao, Guadalupe; Bonner, Gregory F.; Boyer, James L.; Luketic, Velimir A.; Shiffman, Mitchell L.; Peters, Marion G.; White, Heather; Zetterman, Rowen K.; Risser, Richard; Rossi, Stephen S.; Hofmann, Alan F.
2014-01-01
Bile acid composition in fasting duodenal bile was assessed at entry and at 2 years in patients with primary biliary cirrhosis (PBC) enrolled in a randomized, double-blind, placebo-controlled trial of ursodeoxycholic acid (UDCA) (10–12 mg/kg/d) taken as a single bedtime dose. Specimens were analyzed by a high-pressure liquid chromatography method that had been validated against gas chromatography. Percent composition in bile (mean ± SD) for 98 patients at entry for cholic (CA), chenodeoxycholic (CDCA), deoxycholic (DCA), lithocholic (LCA), and ursodeoxycholic (UDCA) acids, respectively, were 57.4 ± 18.6, 31.5 ± 15.5, 8.0 ± 9.3, 0.3 ± 1.0, and 0.6 ± 0.9. Values for CA were increased, whereas those for CDCA, DCA, LCA, and UDCA were decreased when compared with values in normal persons. Bile acid composition of the major bile acids did not change after 2 years on placebo medication. By contrast, in patients receiving UDCA for 2 years, bile became enriched with UDCA on average to 40.1%, and significant decreases were noted for CA (to 32.2%) and CDCA (to 19.5%). No change in percent composition was observed for DCA and LCA. Percent composition at entry and changes in composition after 2 years on UDCA were similar in patients with varying severity of PBC. In patients whose bile was not enriched in UDCA (entry and placebo-treated specimens), CA, CDCA, DCA, and the small amount of UDCA found in some of these specimens were conjugated to a greater extent with glycine (52%–64%) than with taurine (36%–48%). Treatment with UDCA caused the proportion of all endogenous bile acids conjugated with glycine to increase to 69% to 78%, while the proportion conjugated with taurine (22%–31%) fell (P < .05). Administered UDCA was also conjugated predominantly with glycine (87%). PMID:10347103
Shephard, Mark D; Gill, Janice P
2003-01-01
This study describes the development, implementation and management of a multi-faceted quality assurance program called Quality Assurance for Aboriginal Medical Services (QAAMS) to support point-of-care HbA1c testing on the Bayer DCA 2000 in Aboriginal people with diabetes from 45 Australian Aboriginal Community Controlled Health Services. The quality assurance program comprised four elements: production of culturally appropriate education resources, formal training for Aboriginal Health Workers conducting HbA1c testing, an external quality assurance program and on-going quality management support services including a help hotline and an annual workshop. Aboriginal Health Workers were required to test two quality assurance (QAAMS) samples in a blind sense every month since July 1999. Samples were linearly related and comprised six paired levels of HbA1c. The short and long term performance of each service’s DCA 2000 was reviewed monthly and at the end of each six month testing cycle. The average participation rate over 7 six-monthly QAAMS testing cycles was 88%. 84% of 3100 quality assurance tests performed were within preset limits of acceptability. The median precision (CV%) for HbA1c testing has averaged 3.8% across the past 5 cycles (range 3.4 to 4.0%) and is continuing to improve. The introduction of a medical rebate for HbA1c testing has ensured the program’s sustainability. Through continuing education and training, Aboriginal Health Workers have achieved consistent analytical performance for HbA1c testing on the DCA 2000, equivalent to that of laboratory scientists using the same instrument. This unique quality assurance model can be readily adapted to other Indigenous health settings and other point-of-care tests and instruments. PMID:18568052
DOE Office of Scientific and Technical Information (OSTI.GOV)
Skiles, S. K.
1994-12-22
An inductive double-contingency analysis (DCA) method developed by the criticality safety function at the Savannah River Site, was applied in Criticality Safety Evaluations (CSEs) of five major plant process systems at the Westinghouse Electric Corporation`s Commercial Nuclear Fuel Manufacturing Plant in Columbia, South Carolina (WEC-Cola.). The method emphasizes a thorough evaluation of the controls intended to provide barriers against criticality for postulated initiating events, and has been demonstrated effective at identifying common mode failure potential and interdependence among multiple controls. A description of the method and an example of its application is provided.
The Error Structure of the SMAP Single and Dual Channel Soil Moisture Retrievals
NASA Astrophysics Data System (ADS)
Dong, Jianzhi; Crow, Wade T.; Bindlish, Rajat
2018-01-01
Knowledge of the temporal error structure for remotely sensed surface soil moisture retrievals can improve our ability to exploit them for hydrologic and climate studies. This study employs a triple collocation analysis to investigate both the total variance and temporal autocorrelation of errors in Soil Moisture Active and Passive (SMAP) products generated from two separate soil moisture retrieval algorithms, the vertically polarized brightness temperature-based single-channel algorithm (SCA-V, the current baseline SMAP algorithm) and the dual-channel algorithm (DCA). A key assumption made in SCA-V is that real-time vegetation opacity can be accurately captured using only a climatology for vegetation opacity. Results demonstrate that while SCA-V generally outperforms DCA, SCA-V can produce larger total errors when this assumption is significantly violated by interannual variability in vegetation health and biomass. Furthermore, larger autocorrelated errors in SCA-V retrievals are found in areas with relatively large vegetation opacity deviations from climatological expectations. This implies that a significant portion of the autocorrelated error in SCA-V is attributable to the violation of its vegetation opacity climatology assumption and suggests that utilizing a real (as opposed to climatological) vegetation opacity time series in the SCA-V algorithm would reduce the magnitude of autocorrelated soil moisture retrieval errors.
NASA Astrophysics Data System (ADS)
Cheng, Ryan; Morcos, Faruck; Levine, Herbert; Onuchic, Jose
2014-03-01
An important challenge in biology is to distinguish the subset of residues that allow bacterial two-component signaling (TCS) proteins to preferentially interact with their correct TCS partner such that they can bind and transfer signal. Detailed knowledge of this information would allow one to search sequence-space for mutations that can systematically tune the signal transmission between TCS partners as well as re-encode a TCS protein to preferentially transfer signals to a non-partner. Motivated by the notion that this detailed information is found in sequence data, we explore the mutual sequence co-evolution between signaling partners to infer how mutations can positively or negatively alter their interaction. Using Direct Coupling Analysis (DCA) for determining evolutionarily conserved interprotein interactions, we apply a DCA-based metric to quantify mutational changes in the interaction between TCS proteins and demonstrate that it accurately correlates with experimental mutagenesis studies probing the mutational change in the in vitro phosphotransfer. Our methodology serves as a potential framework for the rational design of TCS systems as well as a framework for the system-level study of protein-protein interactions in sequence-rich systems. This research has been supported by the NSF INSPIRE award MCB-1241332 and by the CTBP sponsored by the NSF (Grant PHY-1308264).
Benni, Safiya; Avramoglou, Thierry; Hlawaty, Hanna; Mora, Laurence
2014-01-01
Atherosclerosis is a major cardiovascular disease. One of the side effects is restenosis. The aim of this work was to study the coating of stents by dextran derivates based polyelectrolyte's multilayer (PEM) films in order to increase endothelialization of injured arterial wall after stent implantation. Films were composed with diethylaminoethyl dextran (DEAE) as polycation and dextran sulphate (DS) as polyanion. One film was composed with 4 bilayers of (DEAE-DS)4 and was labeled D-. The other film was the same as D- but with an added terminal layer of DEAE polycation: (DEAE-DS)4-DEAE (labeled D+). The dynamic adsorption/desorption of proteins on the films were characterized by dynamic contact angle (DCA) and atomic force microscopy (AFM). Human endothelial cell (HUVEC) adhesion and proliferation were quantified and correlated to protein adsorption analyzed by DCA for fibronectin, vitronectin, and bovine serum albumin (BSA). Our results showed that the endothelial cell response was optimal for films composed of DS as external layer. Fibronectin was found to be the only protein to exhibit a reversible change in conformation after desorption test. This behavior was only observed for (DEAE-DS)4 films. (DEAE-DS)4 films could enhance HUVEC proliferation in agreement with fibronectin ability to easily change from conformation.
Benni, Safiya; Mora, Laurence
2014-01-01
Atherosclerosis is a major cardiovascular disease. One of the side effects is restenosis. The aim of this work was to study the coating of stents by dextran derivates based polyelectrolyte's multilayer (PEM) films in order to increase endothelialization of injured arterial wall after stent implantation. Films were composed with diethylaminoethyl dextran (DEAE) as polycation and dextran sulphate (DS) as polyanion. One film was composed with 4 bilayers of (DEAE-DS)4 and was labeled D−. The other film was the same as D− but with an added terminal layer of DEAE polycation: (DEAE-DS)4-DEAE (labeled D+). The dynamic adsorption/desorption of proteins on the films were characterized by dynamic contact angle (DCA) and atomic force microscopy (AFM). Human endothelial cell (HUVEC) adhesion and proliferation were quantified and correlated to protein adsorption analyzed by DCA for fibronectin, vitronectin, and bovine serum albumin (BSA). Our results showed that the endothelial cell response was optimal for films composed of DS as external layer. Fibronectin was found to be the only protein to exhibit a reversible change in conformation after desorption test. This behavior was only observed for (DEAE-DS)4 films. (DEAE-DS)4 films could enhance HUVEC proliferation in agreement with fibronectin ability to easily change from conformation. PMID:25276808
Last interglacial semi-desert expansions in southern Africa
NASA Astrophysics Data System (ADS)
Urrego, D. H.; Sanchez Goni, M.; Lechevrel, S.; Daniau, A.
2013-05-01
While our understanding of the effects of orbital-scale variability on the vegetation has grown during the past decades, empirical data from some climatically important periods and regions are still lacking. Scarce data exist for instance for deep-time glacial-interglacial cycles that could provide suitable analogs for current climate change. Recent global-scale syntheses of vegetation responses to rapid events during the last glacial have been useful, however, these global compilations clearly show that some regions, namely the southern tropics and subtropics, remain understudied. We use pollen analysis of marine sediments from core MD96-2098 to produce a paleoenvironmental record from southern Africa spanning MIS 6 to 3. Our interpretations are supported by an analysis of present-day pollen-vegetation-climate relationships for the region. We applied canonical correspondence analysis (CCA) and detrended correspondence analysis (DCA) on pollen spectra from terrestrial surface samples to investigate these relationships and to identify pollen taxa that are suitable bioclimatic indicators for the different South African biomes. Semi-desert vegetation dominated southern Africa during the MIS 5 interglacial. Expansion of the semi-desert biome into the Namib desert likely resulted from the reduction of the Benguela upwelling and a relative decrease in aridity. In its eastern boundary, the semi-desert likely expanded at the expense of grasslands as a result of increased subtropical high pressure and reduced summer precipitation. Semi-desert expansion in its southern boundary probably resulted from reduced influence of the southern westerlies and decreased winter precipitation. This atmospheric configuration was probably exacerbated during the three warm substages of MIS 5. During glacial isotopic stages MIS 6, 4 and 3 grasslands gained area over the semi-desert as summer precipitation increased. The area occupied by Fynbos vegetation was particularly large at the transition MIS 5e to 5d, and the end of MIS 4 with an increased influence of the southern westerlies and austral-winter precipitation. Small and short-lived increases of Podocarpus during transitions between isotopic stages and substages indicated increases of humidity. Our record also suggested an increase in millennial-scale variability after ca. 100 ka that could be associated with enhanced variability of the trade-wind intensity.
Yang, Yongchong; Shang, Peihua; Cheng, Changmei; Wang, Dongchun; Yang, Ping; Zhang, Feng; Li, Tianwen; Lu, Aijun; Zhao, Yufen
2010-09-01
A current study shows that sodium dichloroacetate (DCA) can induce cancer cell apoptosis and inhibit tumor growth, but its cytotoxic activity is low (IC(50) > 1000 microM for A549). In this paper, a variety of DCA derivatives were synthesized, and their cytotoxic activities were evaluated. The result showed that the N-phenyl-2,2-dichloroacetamide analogues had satisfactory potencies. Among them, N-(3-iodophenyl)-2,2-dichloroacetamide (3e), an optimized lead compound, has an IC(50) against A549 as low as 4.76 microM. Furthermore, it can induce cancer cell apoptosis and has a low toxicity in mice (LD(50) = 1117 mg/kg). 2010 Elsevier Masson SAS. All rights reserved.
Studying mixing in Non-Newtonian blue maize flour suspensions using color analysis.
Trujillo-de Santiago, Grissel; Rojas-de Gante, Cecilia; García-Lara, Silverio; Ballescá-Estrada, Adriana; Alvarez, Mario Moisés
2014-01-01
Non-Newtonian fluids occur in many relevant flow and mixing scenarios at the lab and industrial scale. The addition of acid or basic solutions to a non-Newtonian fluid is not an infrequent operation, particularly in Biotechnology applications where the pH of Non-Newtonian culture broths is usually regulated using this strategy. We conducted mixing experiments in agitated vessels using Non-Newtonian blue maize flour suspensions. Acid or basic pulses were injected to reveal mixing patterns and flow structures and to follow their time evolution. No foreign pH indicator was used as blue maize flours naturally contain anthocyanins that act as a native, wide spectrum, pH indicator. We describe a novel method to quantitate mixedness and mixing evolution through Dynamic Color Analysis (DCA) in this system. Color readings corresponding to different times and locations within the mixing vessel were taken with a digital camera (or a colorimeter) and translated to the CIELab scale of colors. We use distances in the Lab space, a 3D color space, between a particular mixing state and the final mixing point to characterize segregation/mixing in the system. Blue maize suspensions represent an adequate and flexible model to study mixing (and fluid mechanics in general) in Non-Newtonian suspensions using acid/base tracer injections. Simple strategies based on the evaluation of color distances in the CIELab space (or other scales such as HSB) can be adapted to characterize mixedness and mixing evolution in experiments using blue maize suspensions.
Summary of the analyses for recovery factors
Verma, Mahendra K.
2017-07-17
IntroductionIn order to determine the hydrocarbon potential of oil reservoirs within the U.S. sedimentary basins for which the carbon dioxide enhanced oil recovery (CO2-EOR) process has been considered suitable, the CO2 Prophet model was chosen by the U.S. Geological Survey (USGS) to be the primary source for estimating recovery-factor values for individual reservoirs. The choice was made because of the model’s reliability and the ease with which it can be used to assess a large number of reservoirs. The other two approaches—the empirical decline curve analysis (DCA) method and a review of published literature on CO2-EOR projects—were deployed to verify the results of the CO2 Prophet model. This chapter discusses the results from CO2 Prophet (chapter B, by Emil D. Attanasi, this report) and compares them with results from decline curve analysis (chapter C, by Hossein Jahediesfanjani) and those reported in the literature for selected reservoirs with adequate data for analyses (chapter D, by Ricardo A. Olea).To estimate the technically recoverable hydrocarbon potential for oil reservoirs where CO2-EOR has been applied, two of the three approaches—CO2 Prophet modeling and DCA—do not include analysis of economic factors, while the third approach—review of published literature—implicitly includes economics. For selected reservoirs, DCA has provided estimates of the technically recoverable hydrocarbon volumes, which, in combination with calculated amounts of original oil in place (OOIP), helped establish incremental CO2-EOR recovery factors for individual reservoirs.The review of published technical papers and reports has provided substantial information on recovery factors for 70 CO2-EOR projects that are either commercially profitable or classified as pilot tests. When comparing the results, it is important to bear in mind the differences and limitations of these three approaches.
NASA Astrophysics Data System (ADS)
Zhao, C. S.; Yang, S. T.; Liu, C. M.; Dou, T. W.; Yang, Z. L.; Yang, Z. Y.; Liu, X. L.; Xiang, H.; Nie, S. Y.; Zhang, J. L.; Mitrovic, S. M.; Yu, Q.; Lim, R. P.
2015-04-01
Aquatic ecological rehabilitation is increasingly attracting considerable public and research attention. An effective method that requires less data and expertise would help in the assessment of rehabilitation potential and in the monitoring of rehabilitation activities as complicated theories and excessive data requirements on assemblage information make many current assessment models expensive and limit their wide use. This paper presents an assessment model for restoration potential which successfully links hydrologic, physical and chemical habitat factors to fish assemblage attributes drawn from monitoring datasets on hydrology, water quality and fish assemblages at a total of 144 sites, where 5084 fish were sampled and tested. In this model three newly developed sub-models, integrated habitat index (IHSI), integrated ecological niche breadth (INB) and integrated ecological niche overlap (INO), are established to study spatial heterogeneity of the restoration potential of fish assemblages based on gradient methods of habitat suitability index and ecological niche models. To reduce uncertainties in the model, as many fish species as possible, including important native fish, were selected as dominant species with monitoring occurring over several seasons to comprehensively select key habitat factors. Furthermore, a detrended correspondence analysis (DCA) was employed prior to a canonical correspondence analysis (CCA) of the data to avoid the "arc effect" in the selection of key habitat factors. Application of the model to data collected at Jinan City, China proved effective reveals that three lower potential regions that should be targeted in future aquatic ecosystem rehabilitation programs. They were well validated by the distribution of two habitat parameters: river width and transparency. River width positively influenced and transparency negatively influenced fish assemblages. The model can be applied for monitoring the effects of fish assemblage restoration. This has large ramifications for the restoration of aquatic ecosystems and spatial heterogeneity of fish assemblages all over the world.
Lu, Li Ping; Wan, Yan Ping; Xun, Peng Cheng; Zhou, Ke Jun; Chen, Cheng; Cheng, Si Yang; Zhang, Min Zhong; Wu, Chun Hua; Lin, Wei Wei; Jiang, Ying; Feng, Hai Xia; Wang, Jia Lu; He, Ka; Cai, Wei
2017-08-01
To determine serum bile acid (BA) and fatty acid (FA) profiles in Chinese children with non-alcoholic fatty liver disease (NAFLD). A total 76 children aged 4-17 years were categorized into three groups according to the presence and absence of as well as the severity of NAFLD, that is, non-NAFLD (control), mild and moderate to severe NAFLD groups, respectively, based on their liver ultrasonography findings. Serum BA and FA profiles were quantified separately by mass spectrometry and gas chromatography. General linear models were performed to assess the differences among the groups. After adjusted for potential confounders, children with NAFLD had higher levels of chenodeoxycholic acid (CDCA), unconjugated primary BAs (CDCA + cholic acid) but lower levels of deoxycholic acid (DCA), taurodeoxycholic acid (TDCA), glycodeoxycholic acid (GDCA), total DCA (DCA + TDCA + GDCA), glycolithocholic acid (GLCA) and total lithocholic acid (GLCA + taurolithocholic acid) than children without NAFLD. As for FAs, children with mild and moderate to severe NAFLD had higher levels of n-7 monounsaturated FA. Circulating BA and FA profiles may change in children with NAFLD. Further studies are needed to determine their associations and to understand the underlying mechanism of action. © 2017 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.
Saito, Masashi; Yano, Kazuhito; Kamigaki, Takashi; Goto, Shigenori
2013-07-01
A 35-year-old female with scirrhous stomach cancer (stage IV) was treated with a combination of 5-aminolevulinic acid (ALA), sodium dichloroacetate (DCA), hyperthermotherapy, and immunotherapy as terminal care. The patient survived for one year and seven months, during which her quality of life was markedly improved and she returned to work. The patient was diagnosed with poorly-differentiated adenocarcinoma and progressive signet-ring cell carcinoma, accompanied by left ovarian metastasis, peritoneal dissemination, and right hydronephrosis stage IV, and treated with combination chemotherapy with tegafur-gimeracil-oteracil potassium (TS-1) and docetaxel. Oral ALA and DCA were concomitantly administered at 50 mg each three times a day (150 mg/day, respectively). In addition, hyperthermotherapy using thermotron was concomitantly performed at 2- to 3-week intervals. Cellular immunotherapy with αβ T- and immature dendritic cells was also performed. The disease did not progress for 11 months, her quality of life was markedly improved, and she was able to return to work. However, the signs of enlargement of the ovarian metastatic lesion were noted later, for which chemotherapy with four cycles of second-line paclitaxel and a half dose of irinotecan and cisplatin as third-line treatment were performed. Combination of ALA/DCA, hyperthermotherapy, and cellular immunotherapy may be a low-invasive palliative therapy superior in maintaining quality of life of tumor-bearing terminally ill individuals.
Haupt, Julia; Deichsel, Alexandra; Stange, Katja; Ast, Cindy; Bocciardi, Renata; Ravazzolo, Roberto; Di Rocco, Maja; Ferrari, Paola; Landi, Antonio; Kaplan, Frederick S.; Shore, Eileen M.; Reissner, Carsten; Seemann, Petra
2014-01-01
Fibrodysplasia ossificans progressiva (FOP) is a disabling genetic disorder of progressive heterotopic ossification (HO). Here, we report a patient with an ultra-rare point mutation [c.619C>G, p.Q207E] located in a codon adjacent to the most common FOP mutation [c.617G>A, p.R206H] of Activin A Receptor, type 1 (ACVR1) and that affects the same intracellular amino acid position in the GS activation domain as the engineered constitutively active (c.a.) variant p.Q207D. It was predicted that both mutations at residue 207 have similar functional effects by introducing a negative charge. Transgenic p.Q207D-c.a. mice have served as a model for FOP HO in several in vivo studies. However, we found that the engineered ACVR1Q207D−c.a. is significantly more active than the classic FOP mutation ACVR1R206H when overexpressed in chicken limbs and in differentiation assays of chondrogenesis, osteogenesis and myogenesis. Importantly, our studies reveal that the ACVR1Q207E resembles the classic FOP receptor in these assays, not the engineered ACVR1Q207D−c.a.. Notably, reporter gene assays revealed that both naturally occurring FOP receptors (ACVR1R206H and ACVR1Q207E) were activated by BMP7 and were sensitive to deletion of the ligand binding domain, whereas the engineered ACVR1Q207D−c.a. exhibited ligand independent activity. We performed an in silico analysis and propose a structural model for p.Q207D-c.a. that irreversibly relocates the GS domain into an activating position, where it becomes ligand independent. We conclude that the engineered p.Q207D-c.a. mutation has severe limitations as a model for FOP, whereas the naturally occurring mutations p.R206H and p.Q207E facilitate receptor activation, albeit in a reversible manner. PMID:24852373
Congressional Black Caucus meets with NASA
2010-01-13
NASA Administrator Charles Bolden, space shuttle crew STS-129 and members of the Congressional Black Caucus pose for a group photo at the Capitol Building, Wednesday, Jan. 13, 2010, in Washington. Back row from left to right: U.S. Rep Donna Edwards (D-MD), U.S. Rep Diane Watson (D-CA), NASA Administrator Charles Bolden, astronauts Leland Melvin, Mike Foreman, Robert Satcher, Barry Wilmore, Randy Breznik, and U.S. Rep Mel Watt (D-NC). Front row from left to right: U.S. Rep Robert Scott (D-VA), U.S. Rep. Corrine Brown (D-Fla), U.S. Rep. Barbara Lee (D-CA), U.S. Rep. Donna Christensen (D-VI) and U.S. Rep. Donald Payne (D-NJ). The crew of STS-129 presented the CBC with a montage commemorating their mission. Photo Credit: (NASA/Paul E. Alers)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Summers, Michael S
2017-11-08
HPC software for ab-initio, condensed-matter physics, quantum mechanics calculations needs to be built on top of well tested libraries some of which address requirements unique to the programming domain. During the development of the DCA++ code, that we use in our research, we have developed a collection of libraries that may be of use to other computational scientists working in the same or similar domains. The libraries include: a) a pythonic input-language system, b) tensors whose shape is constructed from generalized dimension objects such at time domains. frequency domains, momentum domains, vertex domains et. al. and c) linear algebra operationsmore » that resolve to BLA/LAPACK operations when possible. This supports the implementation of Greens functions and operations on them such as are used in condensed matter physics.« less
NASA Astrophysics Data System (ADS)
Yi, Huqiang; Liu, Peng; Sheng, Nan; Gong, Ping; Ma, Yifan; Cai, Lintao
2016-03-01
Smart tumor-targeted drug delivery is crucial for improving the effect of chemotherapy and reducing the adverse effects. Here, we synthesized a smart polypeptide copolymer based on n-butylamine-poly(l-lysine)-b-poly(l-cysteine) (PLL-PLC) with functionalization of folic acid (FA) and 1,2-dicarboxylic-cyclohexene anhydride (DCA) for multistage responsive tumor-targeted drug delivery. The copolymers (FA-PLL(DCA)-PLC) spontaneously crosslinked in situ to form redox and pH dual responsive FA-PLL(DCA)-PLC nanoparticles (FD-NPs), which had a reversible zeta potential around -30 mV at pH 7.4, but switched to +15 mV at pH 5.0. Moreover, FD-NPs effectively loaded DOX with a loading capacity at 15.7 wt%. At pH 7.4, only 24.5% DOX was released within 60 h. However, at pH 5.0, the presence of 10 mM DTT dramatically accelerated DOX release with over 90% of DOX released within 10 h. Although the FD-NPs only enhanced DOX uptake in FA receptor positive (FR+) cancer cells at pH 7.4, a weak acidic condition promoted FD-NP-facilitated DOX uptake in both FR+ HeLa and FR- A549 cells, as well as significantly improving cellular binding and end/lysosomal escape. In vivo studies in a HeLa cancer model demonstrated that the charge-reversible FD-NPs delivered DOX into tumors more effectively than charge-irreversible nanoparticles. Hence, these multistage responsive FD-NPs would serve as highly efficient drug vectors for targeted cancer chemotherapy.Smart tumor-targeted drug delivery is crucial for improving the effect of chemotherapy and reducing the adverse effects. Here, we synthesized a smart polypeptide copolymer based on n-butylamine-poly(l-lysine)-b-poly(l-cysteine) (PLL-PLC) with functionalization of folic acid (FA) and 1,2-dicarboxylic-cyclohexene anhydride (DCA) for multistage responsive tumor-targeted drug delivery. The copolymers (FA-PLL(DCA)-PLC) spontaneously crosslinked in situ to form redox and pH dual responsive FA-PLL(DCA)-PLC nanoparticles (FD-NPs), which had a reversible zeta potential around -30 mV at pH 7.4, but switched to +15 mV at pH 5.0. Moreover, FD-NPs effectively loaded DOX with a loading capacity at 15.7 wt%. At pH 7.4, only 24.5% DOX was released within 60 h. However, at pH 5.0, the presence of 10 mM DTT dramatically accelerated DOX release with over 90% of DOX released within 10 h. Although the FD-NPs only enhanced DOX uptake in FA receptor positive (FR+) cancer cells at pH 7.4, a weak acidic condition promoted FD-NP-facilitated DOX uptake in both FR+ HeLa and FR- A549 cells, as well as significantly improving cellular binding and end/lysosomal escape. In vivo studies in a HeLa cancer model demonstrated that the charge-reversible FD-NPs delivered DOX into tumors more effectively than charge-irreversible nanoparticles. Hence, these multistage responsive FD-NPs would serve as highly efficient drug vectors for targeted cancer chemotherapy. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07348k
Influence of shifting cultivation practices on soil-plant-beetle interactions.
Ibrahim, Kalibulla Syed; Momin, Marcy D; Lalrotluanga, R; Rosangliana, David; Ghatak, Souvik; Zothansanga, R; Kumar, Nachimuthu Senthil; Gurusubramanian, Guruswami
2016-08-01
Shifting cultivation (jhum) is a major land use practice in Mizoram. It was considered as an eco-friendly and efficient method when the cycle duration was long (15-30 years), but it poses the problem of land degradation and threat to ecology when shortened (4-5 years) due to increased intensification of farming systems. Studying beetle community structure is very helpful in understanding how shifting cultivation affects the biodiversity features compared to natural forest system. The present study examines the beetle species diversity and estimates the effects of shifting cultivation practices on the beetle assemblages in relation to change in tree species composition and soil nutrients. Scarabaeidae and Carabidae were observed to be the dominant families in the land use systems studied. Shifting cultivation practice significantly (P < 0.05) affected the beetle and tree species diversity as well as the soil nutrients as shown by univariate (one-way analysis of variance (ANOVA), correlation and regression, diversity indices) and multivariate (cluster analysis, principal component analysis (PCA), detrended correspondence analysis (DCA), canonical variate analysis (CVA), permutational multivariate analysis of variance (PERMANOVA), permutational multivariate analysis of dispersion (PERMDISP)) statistical analyses. Besides changing the tree species composition and affecting the soil fertility, shifting cultivation provides less suitable habitat conditions for the beetle species. Bioindicator analysis categorized the beetle species into forest specialists, anthropogenic specialists (shifting cultivation habitat specialist), and habitat generalists. Molecular analysis of bioindicator beetle species was done using mitochondrial cytochrome oxidase subunit I (COI) marker to validate the beetle species and describe genetic variation among them in relation to heterogeneity, transition/transversion bias, codon usage bias, evolutionary distance, and substitution pattern. The present study revealed the fact that shifting cultivation practice significantly affects the beetle species in terms of biodiversity pattern as well as evolutionary features. Spatiotemporal assessment of soil-plant-beetle interactions in shifting cultivation system and their influence in land degradation and ecology will be helpful in making biodiversity conservation decisions in the near future.
NASA Astrophysics Data System (ADS)
Shupe, Scott Marshall
2000-10-01
Vegetation mapping in and regions facilitates ecological studies, land management, and provides a record to which future land changes can be compared. Accurate and representative mapping of desert vegetation requires a sound field sampling program and a methodology to transform the data collected into a representative classification system. Time and cost constraints require that a remote sensing approach be used if such a classification system is to be applied on a regional scale. However, desert vegetation may be sparse and thus difficult to sense at typical satellite resolutions, especially given the problem of soil reflectance. This study was designed to address these concerns by conducting vegetation mapping research using field and satellite data from the US Army Yuma Proving Ground (USYPG) in Southwest Arizona. Line and belt transect data from the Army's Land Condition Trend Analysis (LCTA) Program were transformed into relative cover and relative density classification schemes using cluster analysis. Ordination analysis of the same data produced two and three-dimensional graphs on which the homogeneity of each vegetation class could be examined. It was found that the use of correspondence analysis (CA), detrended correspondence analysis (DCA), and non-metric multidimensional scaling (NMS) ordination methods was superior to the use of any single ordination method for helping to clarify between-class and within-class relationships in vegetation composition. Analysis of these between-class and within-class relationships were of key importance in examining how well relative cover and relative density schemes characterize the USYPG vegetation. Using these two classification schemes as reference data, maximum likelihood and artificial neural net classifications were then performed on a coregistered dataset consisting of a summer Landsat Thematic Mapper (TM) image, one spring and one summer ERS-1 microwave image, and elevation, slope, and aspect layers. Classifications using a combination of ERS-1 imagery and elevation, slope, and aspect data were superior to classifications carried out using Landsat TM data alone. In all classification iterations it was consistently found that the highest classification accuracy was obtained by using a combination of Landsat TM, ERS-1, and elevation, slope, and aspect data. Maximum likelihood classification accuracy was found to be higher than artificial neural net classification in all cases.
Individual bile acids have differential effects on bile acid signaling in mice
DOE Office of Scientific and Technical Information (OSTI.GOV)
Song, Peizhen, E-mail: songacad@gmail.com; Rockwell, Cheryl E., E-mail: rockwelc@msu.edu; Cui, Julia Yue, E-mail: juliacui@uw.edu
2015-02-15
Bile acids (BAs) are known to regulate BA synthesis and transport by the farnesoid X receptor in the liver (FXR-SHP) and intestine (FXR-Fgf15). However, the relative importance of individual BAs in regulating these processes is not known. Therefore, mice were fed various doses of five individual BAs, including cholic acid (CA), chenodeoxycholic acid (CDCA), deoxoycholic acid (DCA), lithocholic acid (LCA), and ursodeoxycholic acid (UDCA) in their diets at various concentrations for one week to increase the concentration of one BA in the enterohepatic circulation. The mRNA of BA synthesis and transporting genes in liver and ileum were quantified. In themore » liver, the mRNA of SHP, which is the prototypical target gene of FXR, increased in mice fed all concentrations of BAs. In the ileum, the mRNA of the intestinal FXR target gene Fgf15 was increased at lower doses and to a higher extent by CA and DCA than by CDCA and LCA. Cyp7a1, the rate-limiting enzyme in BA synthesis, was decreased more by CA and DCA than CDCA and LCA. Cyp8b1, the enzyme that 12-hydroxylates BAs and is thus responsible for the synthesis of CA, was decreased much more by CA and DCA than CDCA and LCA. Surprisingly, neither a decrease in the conjugated BA uptake transporter (Ntcp) nor increase in BA efflux transporter (Bsep) was observed by FXR activation, but an increase in the cholesterol efflux transporter (Abcg5/Abcg8) was observed with FXR activation. Thus in conclusion, CA and DCA are more potent FXR activators than CDCA and LCA when fed to mice, and thus they are more effective in decreasing the expression of the rate limiting gene in BA synthesis Cyp7a1 and the 12-hydroxylation of BAs Cyp8b1, and are also more effective in increasing the expression of Abcg5/Abcg8, which is responsible for biliary cholesterol excretion. However, feeding BAs do not alter the mRNA or protein levels of Ntcp or Bsep, suggesting that the uptake or efflux of BAs is not regulated by FXR at physiological and pharmacological concentrations of BAs. - Highlights: • All four major bile acids in humans activate the FXR in liver and intestine. • These bile acids decreased the mRNA of the bile acid synthetic enzymes Cyp7a1 and Cyp8b1. • These BAs did not alter the mRNA or protein of the conjugated BA transporters (Ntcp and Bsep). • Cholic acid and deoxycholic acid are more potent activators of FXR than chenodeoxycholic acid and lithocholic acid.« less
Solberg, Leif I; Crain, A Lauren; Maciosek, Michael V; Unützer, Jürgen; Ohnsorg, Kris A; Beck, Arne; Rubenstein, Lisa; Whitebird, Robin R; Rossom, Rebecca C; Pietruszewski, Pamela B; Crabtree, Benjamin F; Joslyn, Kenneth; Van de Ven, Andrew; Glasgow, Russell E
2015-09-01
Scale-up and spread of evidence-based practices is one of the most important challenges facing health care. We tested whether a statewide initiative, Depression Improvement Across Minnesota-Offering a New Direction (DIAMOND), to implement the collaborative care model for depression in 75 primary care clinics resulted in patient outcome improvements corresponding to those reported in randomized controlled trials. Health plans provided a new monthly payment to participating clinics after a 6-month intensive training program with ongoing data submission, networking, and consultation. Implementation was staggered, with 5 sequences of 10 to 40 clinics every 6 months. Payers provided weekly contact information for members from participating clinics who were filling antidepressant prescriptions, and we conducted baseline and 6-month surveys of 1,578 patients about their care and outcomes. There were 466 patients in DIAMOND clinics who received usual care before implementation (UCB), 559 who received usual care in DIAMOND clinics after implementation (UCA), 245 who received DIAMOND care after implementation (DCA), and 308 who received usual care in comparison clinics (UC). Patients who received DIAMOND care after implementation reported more collaborative care depression services than the 3 comparison groups (10.9 vs 6.4-6.7, on a scale of 0 of 14, where higher numbers indicate more services; P <.001) and more satisfaction with their care (4.0 vs 3.4 on a scale 1 to 5, in which higher scores indicate higher satisfaction; P ≤.001). Depression remission rates, however, were not significantly different among the 4 groups (36.4% DCA vs 35.8% UCB, 35.0% UCA, 33.9% UC; P = .94). Despite the incentive of a supporting payment change and intensive training and support for clinics volunteering to participate, no difference in depression outcomes was documented. Specific unmeasured actions present in trials but not present in these clinics may be critical for successful outcome improvement. © 2015 Annals of Family Medicine, Inc.
Directional coronary atherectomy (DCA)
MedlinePlus Videos and Cool Tools
... catheter called a nosecone, and removed after the intervention is complete. Together with rotation of the catheter, ... artery to keep the vessel open. After the intervention is completed the doctor injects contrast media and ...
NASA Astrophysics Data System (ADS)
Rolston, H. M.; Semprini, L.; Thankitkul, S.; Azizian, M.; Hyman, M. R.
2016-12-01
1,4-dioxane (1,4-D) is a frequently observed groundwater contaminant due to its use as a stabilizer in commercial solvent formulations. In situ bioremediation could potentially provide a large cost savings for treatment of mixtures of chlorinated aliphatic hydrocarbons (CAHs) that include 1,4-D. Aerobic cometabolism is a particularly attractive option, as microorganisms can be stimulated in situ using specific primary substrates. Results will be presented that show the model isobutane-metabolizing bacteria, Rhodococcus rhodochrous (ATCC 21198), has the ability to transform 14-D at high rates and transformation capacities to concentrations below the drinking water screening level of 0.67 µg L-1. Resting cell transformation tests showed 1,4-D and a broad range of CAHs can be cometabolized by ATCC 21198. The maximum transformation rate (kmax) and the half-substrate coefficient (Ks) were determined for isobutane (the growth substrate), 1,4-D, 1,1,1-trichloroethane (1,1,1-TCA), 1,1,2-trichloroethane (1,1,2-TCA), 1,1-dichloroethane (1,1-DCA); 1,2-dichloroethane ((1,2-DCA) and 1,1-dichloroethene (1,1-DCE). Of the CAHs tested, 1,1-DCA had the highest kmax, approximately 25% of that for isobutane utilization, while 1,1,1-TCA had the lowest kmax, approximately 2% of isobutane's. 1,4-D was rapidly transformed and had a kmax 25% of that of isobutane. ATCC 21198 effectively transformed mixtures of 1,4-D, 1,1-DCE, 1,2-DCA and 1,1,1-TCA, both in the presence and absence isobutane. Model simulations were performed for the simultaneous cometabolism of 1,4-D and CAH mixtures by ATCC 21198, that included inhibition among the contaminants and isobutane , and terms for a limited transformation capacity. A good match to experimental observations was obtaining using the independently measured rate parameters. Results of model simulations will also be presented using a reactive transport model to evaluate conditions of in situ bioremediation using strain ATCC 21198.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Bin; Li, Huiying; Du, Xiaoming
2016-02-01
During the process of surfactant enhanced aquifer remediation (SEAR), free phase dense non-aqueous phase liquid (DNAPL) may be mobilized and spread. The understanding of the impact of DNAPL spreading on the SEAR remediation is not sufficient with its positive effect infrequently mentioned. To evaluate the correlation between DNAPL spreading and remediation efficiency, a two-dimensional sandbox apparatus was used to simulate the migration and dissolution process of 1,2-DCA (1,2-dichloroethane) DNAPL in SEAR. Distribution area of DNAPL in the sandbox was determined by digital image analysis and correlated with effluent DNAPL concentration. The results showed that the effluent DNAPL concentration has significantmore » positive linear correlation with the DNAPL distribution area, indicating the mobilization of DNAPL could improve remediation efficiency by enlarging total NAPL-water interfacial area for mass transfer. Meanwhile, the vertical migration of 1,2-DCA was limited within the boundary of aquifer in all experiments, implying that by manipulating injection parameters in SEAR, optimal remediation efficiency can be reached while the risk of DNAPL vertical migration is minimized. This study provides a convenient visible and quantitative method for the optimization of parameters for SEAR project, and an approach of rapid predicting the extent of DNAPL contaminant distribution based on the dissolved DNAPL concentration in the extraction well.« less
Effect of Increasing Nitrogen Deposition on Soil Microbial Communities
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xiao, Shengmu; Xue, Kai; He, Zhili
2010-05-17
Increasing nitrogen deposition, increasing atmospheric CO2, and decreasing biodiversity are three main environmental changes occurring on a global scale. The BioCON (Biodiversity, CO2, and Nitrogen) ecological experiment site at the University of Minnesota's Cedar Creek Ecosystem Science Reserve started in 1997, to better understand how these changes would affect soil systems. To understand how increasing nitrogen deposition affects the microbial community diversity, heterogeneity, and functional structure impact soil microbial communities, 12 samples were collected from the BioCON plots in which nitrogenous fertilizer was added to simulate the effect of increasing nitrogen deposition and 12 samples from without added fertilizer. DNAmore » from the 24 samples was extracted using a freeze-grind protocol, amplified, labeled with a fluorescent dye, and then hybridized to GeoChip, a functional gene array containing probes for genes involved in N, S and C cycling, metal resistance and organic contaminant degradation. Detrended correspondence analysis (DCA) of all genes detected was performed to analyze microbial community patterns. The first two axes accounted for 23.5percent of the total variation. The samples fell into two major groups: fertilized and non-fertilized, suggesting that nitrogenous fertilizer had a significant impact on soil microbial community structure and diversity. The functional gene numbers detected in fertilized samples was less that detected in non-fertilizer samples. Functional genes involving in the N cycling were mainly discussed.« less
2016-07-07
engineering (CCE) methods, such as aggregate crater fill and laying replacement concrete. [RAND] • Level 2: CCE plus the use of folded fiberglass ( FFM ...or aluminum mats (e.g., AM-2). [RAND] • Level 3: CCE, FFMs , and Critical Runway Assessment and Repair (CRATR) teams. [RAND] Recovery. In air...CSG carrier strike group CTA central terminal area DCA defensive counterair DoD U.S. Department of Defense FFM folded fiber mats FOB forward
Short Haul Civil Tiltrotor Contingency Power System Preliminary Design
NASA Technical Reports Server (NTRS)
Eames, David J. H.
2006-01-01
Single Langmuir probe measurements are presented over a two-dimensional array of locations in the near Discharge Cathode Assembly (DCA) region of a 30-cm diameter ring cusp ion thruster over a range of thruster operating conditions encompassing the high-power half of the NASA throttling table. The Langmuir probe data were analyzed with two separate methods. All data were analyzed initially assuming an electron population consisting of Maxwellian electrons only. The on-axis data were then analyzed assuming both Maxwellian and primary electrons. Discharge plasma data taken with beam extraction exhibit a broadening of the higher electron temperature plume boundary compared to similar discharge conditions without beam extraction. The opposite effect is evident with the electron/ion number density as the data without began, extraction appears to be more collimated than the corresponding data with beam extraction. Primary electron energy and number densities are presented for one operating condition giving an order of magnitude of their value and the error associated with this calculation.
Discharge Chamber Plasma Structure of a 30-cm NSTAR-Type Ion Engine
NASA Technical Reports Server (NTRS)
Herman, Daniel A.; Gallimore, Alec D.
2006-01-01
Single Langmuir probe measurements are presented over a two-dimensional array of locations in the near Discharge Cathode Assembly (DCA) region of a 30-cm diameter ring cusp ion thruster over a range of thruster operating conditions encompassing the high-power half of the NASA throttling table. The Langmuir probe data were analyzed with two separate methods. All data were analyzed initially assuming an electron population consisting of Maxwellian electrons only. The on-axis data were then analyzed assuming both Maxwellian and primary electrons. Discharge plasma data taken with beam extraction exhibit a broadening of the higher electron temperature plume boundary compared to similar discharge conditions without beam extraction. The opposite effect is evident with the electron/ion number density as the data without began, extraction appears to be more collimated than the corresponding data with beam extraction. Primary electron energy and number densities are presented for one operating condition giving an order of magnitude of their value and the error associated with this calculation.
NASA Astrophysics Data System (ADS)
Murillo, Francisco Javier; Serrano, Alberto; Kenchington, Ellen; Mora, José
2016-03-01
The structure, composition and distribution of epibenthic invertebrate assemblages on the Tail of the Grand Bank of Newfoundland and Flemish Cap (northwest Atlantic) were sampled using depth-stratified trawls. Faunal analysis of 152 uniquely identified taxa produced hierarchical synoptic tables of species associations with diagnostic indicators based on species fidelity. Twelve spatially coherent epibenthic megafaunal assemblages were identified, each with relatively sharp faunal boundaries and unique species attributes. These assemblages were shown a posteriori through ANOSIM to have statistically different species compositions, and were nested within three major regional-scale faunal groups: (I) the continental shelf of the Tail of the Grand Bank, typified by the sea cucumber Cucumaria frondosa and the sand dollar Echinarachnius parma; (II) the upper slope of the Grand Bank and top of Flemish Cap, typified by the sponges Radiella hemisphaerica and Iophon piceum and the sea star Ceramaster granularis; and (III) the lower slope of the Grand Bank and Flemish Cap, typified by the sea urchin Phormosoma placenta, and the sea pens Anthoptilum grandiflorum and Funiculina quadrangularis. Comparisons with literature on benthic species associations from a half century ago suggest that the assemblages identified herein have persisted in the area at least for decades. Detrended correspondence analysis (DCA) identified a well-defined biological gradient along the first axis with very high species turn-over. Ten environmental variables (including Trawling Intensity) were significantly correlated with the ordinated data. At one extreme the continental shelf faunal group (I) was associated with shallow depth (mostly, less than 200 m), coarse sediments and cold and fresh water associated with the Labrador Current. At the other extreme the lower slope faunal group (III; stations below 500-600 m throughout the study area) was strongly associated with deep water, muddy sediments, and warmer and saltier water. Conditional tests under a step-wise model identified the percentage of mud as having the greatest explanatory power (40%) of the tested environmental variables. Trawling Intensity explained 11% of the variation in the full data set in marginal tests. Species richness in the deep water assemblages (Cluster III) was significantly and negatively correlated with fishing intensity. The species most directly associated with high trawling intensity in the DCA were the hard-shelled scavenging and predatory gastropods and a thick-shelled bivalve, consistent with expectations based on the trawling impact literature. Our study fills a critical knowledge gap in this important fishing area, and our novel regional-scale maps of the epibenthic assemblages will facilitate the development of ecosystem-based models linking benthic and pelagic systems and inform biodiversity conservation.
Precision Orbit Derived Atmospheric Density: Development and Performance
NASA Astrophysics Data System (ADS)
McLaughlin, C.; Hiatt, A.; Lechtenberg, T.; Fattig, E.; Mehta, P.
2012-09-01
Precision orbit ephemerides (POE) are used to estimate atmospheric density along the orbits of CHAMP (Challenging Minisatellite Payload) and GRACE (Gravity Recovery and Climate Experiment). The densities are calibrated against accelerometer derived densities and considering ballistic coefficient estimation results. The 14-hour density solutions are stitched together using a linear weighted blending technique to obtain continuous solutions over the entire mission life of CHAMP and through 2011 for GRACE. POE derived densities outperform the High Accuracy Satellite Drag Model (HASDM), Jacchia 71 model, and NRLMSISE-2000 model densities when comparing cross correlation and RMS with accelerometer derived densities. Drag is the largest error source for estimating and predicting orbits for low Earth orbit satellites. This is one of the major areas that should be addressed to improve overall space surveillance capabilities; in particular, catalog maintenance. Generally, density is the largest error source in satellite drag calculations and current empirical density models such as Jacchia 71 and NRLMSISE-2000 have significant errors. Dynamic calibration of the atmosphere (DCA) has provided measurable improvements to the empirical density models and accelerometer derived densities of extremely high precision are available for a few satellites. However, DCA generally relies on observations of limited accuracy and accelerometer derived densities are extremely limited in terms of measurement coverage at any given time. The goal of this research is to provide an additional data source using satellites that have precision orbits available using Global Positioning System measurements and/or satellite laser ranging. These measurements strike a balance between the global coverage provided by DCA and the precise measurements of accelerometers. The temporal resolution of the POE derived density estimates is around 20-30 minutes, which is significantly worse than that of accelerometer derived density estimates. However, major variations in density are observed in the POE derived densities. These POE derived densities in combination with other data sources can be assimilated into physics based general circulation models of the thermosphere and ionosphere with the possibility of providing improved density forecasts for satellite drag analysis. POE derived density estimates were initially developed using CHAMP and GRACE data so comparisons could be made with accelerometer derived density estimates. This paper presents the results of the most extensive calibration of POE derived densities compared to accelerometer derived densities and provides the reasoning for selecting certain parameters in the estimation process. The factors taken into account for these selections are the cross correlation and RMS performance compared to the accelerometer derived densities and the output of the ballistic coefficient estimation that occurs simultaneously with the density estimation. This paper also presents the complete data set of CHAMP and GRACE results and shows that the POE derived densities match the accelerometer densities better than empirical models or DCA. This paves the way to expand the POE derived densities to include other satellites with quality GPS and/or satellite laser ranging observations.
26 CFR 301.6104(a)-6 - Procedural rules for inspection.
Code of Federal Regulations, 2010 CFR
2010-04-01
... Revenue, Attention: Freedom of Information Reading Room, 1111 Constitution Avenue, NW., Washington, D.C...(a)-3 will be made available for inspection at the Freedom of Information Reading Room, National...
NASA Astrophysics Data System (ADS)
Tabrizi, Leila; Chiniforoshan, Hossein; McArdle, Patrick
2015-03-01
A novel 1D coordination polymer {[Mn(μ1,5-dca)2(PZA)2](PZA)2}n, 1, has been synthesized and characterized by single crystal X-ray crystallography. The coordination mode of dicyanamide (dca) and pyrazinamide (PZA) ligands was inferred by IR spectroscopy. The compound 1 was evaluated for in vitro antimycobacterial and antitumor activities. It demonstrated better in vitro activity against Mycobacterium tuberculosis than pyrazinamide and its MIC value was determined. Complex 1 was also screened for its in vitro antitumor activity towards LM3 and LP07 murine cancer cell lines. In addition, the antibacterial activity of complex 1 has been tested against Gram(+) and Gram(-) bacteria and it has shown promising broad range anti-bacterial activity.
NASA Astrophysics Data System (ADS)
Zhao, Hai-Yan; Yang, Fu-Li; Li, Na; Wang, Xiao-Jing
2017-11-01
Two new dinuclear Cd(II) complexes, [CdL1Cl2]2·H2O (1) and [CdL1(N3)2]2·CH3OH (2) and one dicyanamide bridged one-dimensional polynuclear network [CdL1(μ1,5-dca)dca]n (3) of the potentially tridentate NNN-donor Schiff base 2-((1H-benzimidazol-2-yl-ethylimino)-methyl)pyridine (L1) and another dinucler Cd(II) complex [CdL2Cl(dca)]2 (4) of a similar NNN-donor Schiff base ligand 2-((1H-benzimidazol-2-yl-propylimino)-methyl)pyridine (L2), have been synthesized and characterized by elemental analyses, IR and single crystal X-ray crystallography. The ligands L1 and L2 are [1 + 1] condensation products of pyridine-2-carbaldehyde with 2-aminoethyl-1H-benzimidazole and 2-aminopropyl-1H-benzimidazole, respectively. In the complexes 1 and 4 the two Cd(II) centers are held together by the bridged chloride ligands, while in 2 the two Cd(II) centers are bridged by μ1,1-azide ions. Complex 3 has a one-dimensional infinite chain structure in which Cd(II) ions are bridged by single dicyanamide groups in end-to-end fashion. All the metal centers have a distorted octahedral geometry and H-bonding or π⋯π interactions are operative to bind the complex units in the solid state. Furthermore, these complexes have been investigated by thermogravimetric analyses and fluorescence spectra.
Analysis of Anammox Bacterial Comunity Structure and Habitat of the Yangcheng Lake
NASA Astrophysics Data System (ADS)
Zhang, Y.; Ruan, X.
2011-12-01
Anaerobic ammonium oxidation (anammox) is a new pathway of nitrogen transformation processed by anammox bacteria. It produces dinitrogen gas under anoxic conditions by combining ammonium and nitrite. Recently, most of anammox bacteria species have been identified in freshwater systems around the world. However, little is known about the anammox bacteria abundance and diversity under different habitats. Yangcheng Lake, located in Yangtze River Delta, is a middle-pattern shallow lake (average depth 2.05 m) containing three interconnected lakes. The average sediment thickness is about 10 cm. Thirteen sediment and corresponding overlying water samples were collected in different seasons for physicochemical and molecular analysis. Anammox specified sequences were amplified from the 16S rRNA of sediment bacteria with anammox specific primers by nest PCR. The sequences were cloned into T-vector to establish the gene library and assigned to operational taxonomic units (OTUs) by cluster analysis. Sequences were blasted in NCBI (http://blast.ncbi.nlm.nih.gov), to construct the phylogenetic tree. Anammox-specific sequences were amplified from all 13 sediment samples. The sequences were mainly affiliated to the Candidatus Brocadia spp., and then affiliated to the Candidatus Kuenenia spp., both of them were the popular anammox species in freshwater systems. Results of physiochemical analysis of the overlying water and sediment pore-water showed that ammonia was the main component of the total inorganic nitrogen. The nitrogen concentrations of the overlying water and pore-water were ranged from 0.18 mg/L to 3.18 mg/L and 6.5 mg/L to 33.71 mg/L for ammonium , 0.01 mg/L to 0.09 mg/L and 0.02 mg/L to 0.20 mg/L for nitrite and 0.05 mg/L to 1.11 mg/L and 0.08 mg/L to 3.27 mg/L for nitrate, respectively. Relationships between the anammox bacterial community structure and environmental factors were analyzed by Detrended correspondence analysis (DCA). The results shows that, the higher concentration of overlying water temperature, NO3- concentration implied a higher abundance of Candidatus Brocadia spp., while the higher concentration of DO and NO2- of overlying water and higher sediment LOI may imply higher abundance of Candidatus Kuenenia spp..
Studying Mixing in Non-Newtonian Blue Maize Flour Suspensions Using Color Analysis
Trujillo-de Santiago, Grissel; Rojas-de Gante, Cecilia; García-Lara, Silverio; Ballescá-Estrada, Adriana; Alvarez, Mario Moisés
2014-01-01
Background Non-Newtonian fluids occur in many relevant flow and mixing scenarios at the lab and industrial scale. The addition of acid or basic solutions to a non-Newtonian fluid is not an infrequent operation, particularly in Biotechnology applications where the pH of Non-Newtonian culture broths is usually regulated using this strategy. Methodology and Findings We conducted mixing experiments in agitated vessels using Non-Newtonian blue maize flour suspensions. Acid or basic pulses were injected to reveal mixing patterns and flow structures and to follow their time evolution. No foreign pH indicator was used as blue maize flours naturally contain anthocyanins that act as a native, wide spectrum, pH indicator. We describe a novel method to quantitate mixedness and mixing evolution through Dynamic Color Analysis (DCA) in this system. Color readings corresponding to different times and locations within the mixing vessel were taken with a digital camera (or a colorimeter) and translated to the CIELab scale of colors. We use distances in the Lab space, a 3D color space, between a particular mixing state and the final mixing point to characterize segregation/mixing in the system. Conclusion and Relevance Blue maize suspensions represent an adequate and flexible model to study mixing (and fluid mechanics in general) in Non-Newtonian suspensions using acid/base tracer injections. Simple strategies based on the evaluation of color distances in the CIELab space (or other scales such as HSB) can be adapted to characterize mixedness and mixing evolution in experiments using blue maize suspensions. PMID:25401332
77 FR 23513 - Sunshine Act Meeting; Agenda
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-19
... Maintenance-of-Way Equipment Train, Red Oak, Iowa, April 17, 2011 (DCA-11-FR-002) NEWS MEDIA CONTACT... archived webcast by accessing a link under ``News & Events'' on the NTSB home page at www.ntsb.gov...
Irinotecan (CPT-11)-induced elevation of bile acids potentiates suppression of IL-10 expression
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fang, Zhong-Ze; Department of Toxicology, School of Public Health, Tianjin Medical University, Tianjin; Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences and First Affiliated Hospital of Liaoning Medical University, Dalian
Irinotecan (CPT-11) is a first-line anti-colon cancer drug, however; CPT-11-induced toxicity remains a key factor limiting its clinical application. To search for clues to the mechanism of CPT-11-induced toxicity, metabolomics was applied using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry. Intraperitoneal injection of 50 mg/kg of CPT-11 induced loss of body weight, and intestine toxicity. Changes in gallbladder morphology suggested alterations in bile acid metabolism, as revealed at the molecular level by analysis of the liver, bile, and ileum metabolomes between the vehicle-treated control group and the CPT-11-treated group. Analysis of immune cell populations further showedmore » that CPT-11 treatment significantly decreased the IL-10-producing CD4 T cell frequency in intestinal lamina propria lymphocytes, but not in spleen or mesenteric lymph nodes. In vitro cell culture studies showed that the addition of bile acids deoxycholic acid and taurodeoxycholic acid accelerated the CPT-11-induced suppression of IL-10 secretion by activated CD4{sup +} naive T cells isolated from mouse splenocytes. These results showed that CPT-11 treatment caused metabolic changes in the composition of bile acids that altered CPT-11-induced suppression of IL-10 expression. - Highlights: • CPT-11 is an effective anticancer drug, but induced toxicity limits its application in the clinic. • CPT-11 decreased IL-10-producing CD4 T cell frequency in intestinal lamina propria lymphocytes. • CPT-11 altered the composition of bile acid metabolites, notably DCA and TDCA in liver, bile and intestine. • DCA and TDCA potentiated CPT-11-induced suppression of IL-10 secretion by active CD4{sup +} naive T cells.« less
75 FR 880 - Sunshine Act Meeting Notice
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-06
..., September 12, 2008. (DCA-08-MR-009). News Media Contact: Telephone: (202) 314-6100. The press and public may.... The public may view the meeting via a live or archived webcast by accessing a link under ``News...
An Extended Deterministic Dendritic Cell Algorithm for Dynamic Job Shop Scheduling
NASA Astrophysics Data System (ADS)
Qiu, X. N.; Lau, H. Y. K.
The problem of job shop scheduling in a dynamic environment where random perturbation exists in the system is studied. In this paper, an extended deterministic Dendritic Cell Algorithm (dDCA) is proposed to solve such a dynamic Job Shop Scheduling Problem (JSSP) where unexpected events occurred randomly. This algorithm is designed based on dDCA and makes improvements by considering all types of signals and the magnitude of the output values. To evaluate this algorithm, ten benchmark problems are chosen and different kinds of disturbances are injected randomly. The results show that the algorithm performs competitively as it is capable of triggering the rescheduling process optimally with much less run time for deciding the rescheduling action. As such, the proposed algorithm is able to minimize the rescheduling times under the defined objective and to keep the scheduling process stable and efficient.
Bis(2,3,5,6-tetra-2-pyridylpyrazine-κ3 N 2,N 1,N 6)iron(II) bis(dicyanamidate) 4.5-hydrate
Callejo, L.; De la Pinta, N.; Madariaga, G.; Fidalgo, M.L.; Cortés, R.
2010-01-01
In the title compound, [Fe(C24H16N6)2][N(CN)2]2·4.5H2O, the central iron(II) ion is hexacoordinated by six N atoms of two tridentate 2,3,5,6-tetra-2-pyridylpyrazine (tppz) ligands. Two dicyanamide anions [dca or N(CN)2 −] act as counter-ions, and 4.5 water molecules act as solvation agents. The structure contains isolated cationic iron(II)–tppz complexes and the final neutrality is obtained with the two dicyanamide anions. One of the dicyanamide anions and a water molecule are disordered with an occupancy ratio of 0.614 (8):0.386 (8). O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds involving dca, water and tppz molecules are observed. PMID:21580205
A Slot Allocation Model for High-Density Airports.
1980-08-01
Syracuse 51.85 ISO Kinston, N.C. 57.41 TPA Tampa 99.07 ISP Islip MacArthur 47.22 TYS Knoxville 67.59 JAX Jacksonville 8’i.26 C-3 TABLE 2 THIRD QUARTER... ISO 245 PI 2. 97. 116. 0.836 3 3 2 2 2 ISO DCA 245 PI 1. 71. 100. 0.710 2 1 1 1 1 uCA GSO 248 EA 2. 191. 229. 0.834 3 3 2 2 2 GS! DCA 248 3. 229. 307...0 1 1 0 0 0 1 1 t 0 1 1 1 0 1 i0 0 0 0 0 1 1 0 0 0 0 0 0 0 2 0 0 4 11 11 13 11 10 11 12 11 7 10 7 9 9 i 8 9 ISO IThP5 1 0 0 0 1 1 0 0 0 0 0 0 0 0 1 2
[Television and eating disorders. Study of adolescent eating behavior].
Verri, A P; Verticale, M S; Vallero, E; Bellone, S; Nespoli, L
1997-06-01
The media, mainly TV, play a significant social and cultural role and may affect the prevalence and incidence of eating disorders such as bulimia and anorexia nervosa. Their influence acts mainly by favoring a tall and thin body as the only fashionable for female adolescents: your social success depends primarily and totally by your physical appearance and you can, (and must), shape your body as you like better. Our research aims t analyze the attitude of adolescent people toward the TV and to investigate on: 1) time spent watching TV programs; 2) the influence of TV on the personal choices of goods to buy; 3) the ideal body images; 4) choice of TV programs. Sixty-seven healthy adolescents (36 F-31 M) were included in our study as controls together with 24 female adolescents with eating disorders (DCA) diagnosed according to the DSM-IV and EAT/26 criteria. Our results show a psychological dependence of DCA adolescents from the TV (longer period of time spent watching TV programs, buying attitudes more influenced by TV advertising). The thin and tall body image is preferred by the DCA girls as well as by the controls; however the body appearance and proportions have a predominant and utmost importance only for the eating disorder females. The masculine subjects instead have a preference for a female and masculine opulent body appearance. To prevent the observed increase in prevalence and incidence of eating disorders among adolescents, it is appropriate to control the messages, myths and false hood propagated by media, TV in particular.
Caldwell, Jane C.; Keshava, Nagalakshmi
2006-01-01
Trichloroethylene (TCE) exposure has been associated with increased risk of liver and kidney cancer in both laboratory animal and epidemiologic studies. The U.S. Environmental Protection Agency 2001 draft TCE risk assessment concluded that it is difficult to determine which TCE metabolites may be responsible for these effects, the key events involved in their modes of action (MOAs), and the relevance of these MOAs to humans. In this article, which is part of a mini-monograph on key issues in the health risk assessment of TCE, we present a review of recently published scientific literature examining the effects of TCE metabolites in the context of the preceding questions. Studies of the TCE metabolites dichloroacetic acid (DCA), trichloroacetic acid (TCA), and chloral hydrate suggest that both DCA and TCA are involved in TCE-induced liver tumorigenesis and that many DCA effects are consistent with conditions that increase the risk of liver cancer in humans. Studies of S-(1,2-dichlorovinyl)-l-cysteine have revealed a number of different possible cell signaling effects that may be related to kidney tumorigenesis at lower concentrations than those leading to cytotoxicity. Recent studies of trichloroethanol exploring an alternative hypothesis for kidney tumorigenesis have failed to establish the formation of formate as a key event for TCE-induced kidney tumors. Overall, although MOAs and key events for TCE-induced liver and kidney tumors have yet to be definitively established, these results support the likelihood that toxicity is due to multiple metabolites through several MOAs, none of which appear to be irrelevant to humans. PMID:16966105
NASA Astrophysics Data System (ADS)
Munayco, Pablo; Munayco, Jimmy; Avillez, Roberto R.; Valenzuela, Millarca; Rochette, Pierre; Gattacceca, JéRôMe; Scorzelli, Rosa B.
2013-03-01
Some terrestrial areas have climatic and geomorphologic features that favor the preservation, and therefore, accumulation of meteorites. The Atacama Desert in Chile is among the most important of such areas, known as DCA. This desert is the driest on Earth, one of the most arid, uninhabitable localities with semiarid, arid, and hyper-arid conditions. The meteorites studied here were collected from within the DCA of San Juan and Pampa de Mejillones, located, respectively, in the Central Depression and the Coastal Range of the Atacama Desert. 57Fe Mössbauer spectroscopy was used for quantitative analysis of the degree of weathering of the meteorites, through the determination of the proportions of the various Fe-bearing phases and in particular the amount of oxidized iron in terrestrial alteration products. The abundance of ferric ions in weathered chondrites can be related to specific precursor compositions and to the level of terrestrial weathering. The aim of the study was the identification, quantification, and differentiation of the weathering products in the ordinary chondrites found in the San Juan and the Pampa de Mejillones areas of the Atacama Desert. The 57Fe Mössbauer spectroscopy study was complemented by synchrotron radiation X-ray diffraction and magnetic susceptibility measurements. The results allow a clear differentiation of the rate of weathering in meteorite samples collected from the San Juan versus the Pampa de Mejillones areas of the Atacama Desert.
Hladik, Michelle; Calhoun, Daniel L.
2012-01-01
A method for the determination of the widely used herbicide diuron, three degradates of diuron, and six neonicotinoid insecticides in environmental water samples is described. Filtered water samples were extracted by using solid-phase extraction (SPE) with no additional cleanup steps. Quantification of the pesticides from the extracted water samples was done by using liquid chromatography with tandem mass spectrometry (LC/MS/MS). Recoveries in test water samples fortified at 20 nanograms per liter (ng/L) for each compound ranged from 75 to 97 percent; relative standard deviations ranged from 5 to 10 percent. Method detection limits (MDLs) in water ranged from 3.0 to 6.2 ng/L using LC/MS/MS. The method was applied to water samples from two streams in Georgia, Sope Creek and the Chattahoochee River. Diuron and 3,4-dichloroaniline (3,4-DCA) were detected in 100 and 80 percent, respectively, of the samples from the Chattahoochee River, whereas Sope creek had detection frequencies of 15 percent for diuron and 31 percent for 3,4-DCA. Detection frequencies for the neonicotinoid insecticide, imidacloprid, were 60 percent for the Chattahoochee River and 85 percent for Sope Creek. Field matrix-spike recoveries for each compound, when averaged over four water samples, ranged from 79 to 100 percent. The average percentage difference between replicate pairs for all compounds detected in the field samples was 10.1 (± 4.5) percent.
Cucchetti, Alessandro; Cescon, Matteo; Colecchia, Antonio; Neri, Flavia; Cappelli, Alberta; Ravaioli, Matteo; Mazzotti, Federico; Ercolani, Giorgio; Festi, Davide; Pinna, Antonio Daniele
2017-10-01
Purpose Liver stiffness (LS) has been shown to be of use in chronic liver disease patients but its utility in surgical judgment still needs to be proven. A decision-making approach was applied to evaluate whether LS measurement before surgery of hepatocellular carcinoma (HCC) can be useful in avoiding post-hepatectomy liver failure (PHLF). Materials and Methods Decision curve analysis (DCA) was applied to 202 HCC patients (2008 - 14) with LS measurement prior to hepatectomy to verify whether the occurrence of PHLF grades B/C should be reduced through a decision-making approach with LS. Results Within 90 days of surgery, 4 patients died (2 %) and grades B/C PHLF occurred in 29.7 % of cases. Ascites and/or pleural effusion, treatable with medical therapy, were the most frequent complications. DCA showed that using the "expected utility theory" LS measurement can reduce up to 39 % of cases of PHLF without the exclusion of any patient from surgery that duly undergoes an uncomplicated postoperative course. LS measurement does not add any information to normal clinical judgment for patients with a low (< 10 %) risk of PHLF. Conclusion LS measurement can determine a reduction of PHLF under "expected utility theory" fulfilment. However, the degree of PHLF can be minor and "risk seeking" individuals can accept such a risk on the basis of surgical benefits. © Georg Thieme Verlag KG Stuttgart · New York.
IMPROVING MEASURES OF BIOLOGIC EFFECT: MEASURING EFFECTS IN HUMAN MALES
Animal toxicology studies have demonstrated spermatogenesis and sperm quality effects after exposure to several drinking water disinfection byproducts (DBPs), including DCA, BDCM, chloral hydrate and DBA. Population-based field studies to identify human male reproductive risks o...
Wang, Shuang; Guo, Zhen-Ni; Xing, Yingqi; Ma, Hongyin; Jin, Hang; Liu, Jia; Yang, Yi
2015-01-01
Abstract The aim of the study was to assess the capacity of dynamic cerebral autoregulation (dCA) in asymptomatic patients with unilateral middle cerebral artery (MCA) stenosis. Fifty-seven patients with asymptomatic mild, moderate, and severe unilateral MCA stenosis and 8 patients with symptomatic severe unilateral MCA stenosis diagnosed by transcranial Doppler were enrolled. Twenty-four healthy volunteers served as controls. The noninvasive continuous cerebral blood flow velocity and arterial blood pressure were recorded simultaneously from each subject in the supine position. Transfer function analysis was applied to determine the autoregulatory parameters (phase difference [PD] and gain). The PD values in the severe stenosis groups were significantly lower than those of the control group (60.71 ± 18.63°), the asymptomatic severe stenosis group was impaired ipsilaterally (28.94 ± 27.43°, P < 0.001), and the symptomatic severe stenosis group was impaired bilaterally (13.74 ± 19.21°, P < 0.001; 19.68 ± 14.50°, P = 0.006, respectively). The PD values in the mild and moderate stenosis groups were not significantly different than the controls (44.49 ± 27.93°; 48.65 ± 25.49°, respectively). The gain values in the mild and moderate groups were higher than in the controls (1.00 ± 0.58 cm/s/mm Hg vs 0.86 ± 0.34 cm/s/mm Hg, and 1.20 ± 0.59 cm/s/mm Hg vs 0.86 ± 0.34 cm/s/mm Hg, respectively). The gain values in the severe stenosis groups were significantly lower than that in the control group: the asymptomatic severe stenosis group was lower bilaterally (0.56 ± 0.32 cm/s/mm Hg, P = 0.003; 0.60 ± 0.32 cm/s/mm Hg, P < 0.05, respectively), whereas the symptomatic severe group was lower unilaterally (on the contralateral side) (0.53 ± 0.43 cm/s/mm Hg, P < 0.05). In asymptomatic patients with unilateral MCA stenosis, only the dCA of the severe stenosis was ipsilaterally impaired. Acute stroke may aggravate the impaired dCA and even spread contralaterally. PMID:26717363
Chapter 9 : getting ready for NextGen.
DOT National Transportation Integrated Search
2008-01-01
George W. Bush became the forty-third president on January 20, : 2001. Five days later, former Member of Congress Norman Mineta : (D-CA) took the oath of office as the nations fourteenth Secretary : of Transportation. The lone Democrat in George W...
Spermatotoxicity of dichloroacetic acid
The testicular toxicity of dichloroacetic acid (DCA), a disinfection byproduct of drinking water, was evaluated in adult male rats given both single and multiple (up to 14 d) oral doses. Delayed spermiation and altered resorption of residual bodies were observed in rats given sin...
IMPROVING MEASURES OF BIOLOGIC EFFECT: MEASURING EFFECTS IN HUMAN MALES.
Animal toxicology studies have demonstrated spermatogenesis and sperm quality effects after exposure to DCA, BDCM, chloral hydrate and DBA. Population-based field studies to identify human male reproductive risks of DBPs require preliminary work to develop specific epidemiologi...
Soil seed bank in different habitats of the Eastern Desert of Egypt.
Gomaa, Nasr H
2012-04-01
The floristic composition and species diversity of the germinable soil seed bank were studied in three different habitats (desert salinized land, desert wadi, and reclaimed land) in the Eastern Desert of Egypt. Moreover, the degree of similarity between the seed bank and the above-ground vegetation was determined. The seed bank was studied in 40 stands representing the three habitats. Ten soil samples (each 25 × 20 cm and 5 cm depth) were randomly taken per stand. The seed bank was investigated by the seedling emergence method. Some 61 species belonging to 21 families and 54 genera were identified in the germinable seed bank. The recorded species include 43 annuals and 18 perennials. Ordination of stands by Detrended Correspondence Analysis (DCA) indicates that the stands of the three habitats are markedly distinguishable and show a clear pattern of segregation on the ordination planes. This indicates variations in the species composition among habitats. The results also demonstrate significant associations between the floristic composition of the seed bank and edaphic factors such as CaCO3, electrical conductivity, organic carbon and soil texture. The reclaimed land has the highest values of species richness, Shannon-index of diversity and the density of the germinable seed bank followed by the habitats of desert wadi and desert salinized land. Motyka's similarity index between the seed bank and the above-ground vegetation is significantly higher in reclaimed land (75.1%) compared to desert wadi (38.4%) and desert salinized land (36.5%).
Examination of age-related epigenetic changes following early-life exposure to dichloroacetic acid
Recent studies have shown that transient early-life exposure to dichloroacetic acid (DCA), a pyruvate analog and metabolic reprogramming agent, increases liver cancer incidence in older mice. This carcinogenic effect is not associated with direct mutagenicity, persistent cytotoxi...
Disentangling environmental correlates of vascular plant biodiversity in a Mediterranean hotspot.
Molina-Venegas, Rafael; Aparicio, Abelardo; Pina, Francisco José; Valdés, Benito; Arroyo, Juan
2013-10-01
We determined the environmental correlates of vascular plant biodiversity in the Baetic-Rifan region, a plant biodiversity hotspot in the western Mediterranean. A catalog of the whole flora of Andalusia and northern Morocco, the region that includes most of the Baetic-Rifan complex, was compiled using recent comprehensive floristic catalogs. Hierarchical cluster analysis (HCA) and detrended correspondence analysis (DCA) of the different ecoregions of Andalusia and northern Morocco were conducted to determine their floristic affinities. Diversity patterns were studied further by focusing on regional endemic taxa. Endemic and nonendemic alpha diversities were regressed to several environmental variables. Finally, semi-partial regressions on distance matrices were conducted to extract the respective contributions of climatic, altitudinal, lithological, and geographical distance matrices to beta diversity in endemic and nonendemic taxa. We found that West Rifan plant assemblages had more similarities with Andalusian ecoregions than with other nearby northern Morocco ecoregions. The endemic alpha diversity was explained relatively well by the environmental variables related to summer drought and extreme temperature values. Of all the variables, geographical distance contributed by far the most to spatial turnover in species diversity in the Baetic-Rifan hotspot. In the Baetic range, elevation was the most significant driver of nonendemic species beta diversity, while lithology and elevation were the main drivers of endemic beta diversity. Despite the fact that Andalusia and northern Morocco are presently separated by the Atlantic Ocean and the Mediterranean Sea, the Baetic and Rifan mountain ranges have many floristic similarities - especially in their western ranges - due to past migration of species across the Strait of Gibraltar. Climatic variables could be shaping the spatial distribution of endemic species richness throughout the Baetic-Rifan hotspot. Determinants of spatial turnover in biodiversity in the Baetic-Rifan hotspot vary in importance between endemic and nonendemic species.
Vegetation, soil, and flooding relationships in a blackwater floodplain forest
Burke, M.K.; King, S.L.; Gartner, D.; Eisenbies, M.H.
2003-01-01
Hydroperiod is considered the primary determinant of plant species distribution in temperate floodplain forests, but most studies have focused on alluvial (sediment-laden) river systems. Few studies have evaluated plant community relationships in blackwater river systems of the South Atlantic Coastal Plain of North America. In this study, we characterized the soils, hydroperiod, and vegetation communities and evaluated relationships between the physical and chemical environment and plant community structure on the floodplain of the Coosawhatchie River, a blackwater river in South Carolina, USA. The soils were similar to previous descriptions of blackwater floodplain soils but had greater soil N and P availability, substantially greater clay content, and lower soil silt content than was previously reported for other blackwater river floodplains. Results of a cluster analysis showed there were five forest communities on the site, and both short-term (4 years) and long-term (50 years) flooding records documented a flooding gradient: water tupelo community > swamp tupelo > laurel oak = overcup oak > mixed oak. The long-term hydrologic record showed that the floodplain has flooded less frequently from 1994 to present than in previous decades. Detrended correspondence analysis of environmental and relative basal area values showed that 27% of the variation in overstory community structure could be explained by the first two axes; however, fitting the species distributions to the DCA axes using Gaussian regression explained 67% of the variation. Axes were correlated with elevation (flooding intensity) and soil characteristics related to rooting volume and cation nutrient availability. Our study suggests that flooding is the major factor affecting community structure, but soil characteristics also may be factors in community structure in blackwater systems. ?? 2003, The Society of Wetland Scientists.
Palau, Jordi; Shouakar-Stash, Orfan; Hatijah Mortan, Siti; Yu, Rong; Rosell, Monica; Marco-Urrea, Ernest; Freedman, David L; Aravena, Ramon; Soler, Albert; Hunkeler, Daniel
2017-09-19
Even though multi-element isotope fractionation patterns provide crucial information with which to identify contaminant degradation pathways in the field, those involving hydrogen are still lacking for many halogenated groundwater contaminants and degradation pathways. This study investigates for the first time hydrogen isotope fractionation during both aerobic and anaerobic biodegradation of 1,2-dichloroethane (1,2-DCA) using five microbial cultures. Transformation-associated isotope fractionation values (ε bulk H ) were -115 ± 18‰ (aerobic C-H bond oxidation), -34 ± 4‰ and -38 ± 4‰ (aerobic C-Cl bond cleavage via hydrolytic dehalogenation), and -57 ± 3‰ and -77 ± 9‰ (anaerobic C-Cl bond cleavage via reductive dihaloelimination). The dual-element C-H isotope approach (Λ C-H = Δδ 2 H/Δδ 13 C ≈ ε bulk H /ε bulk C , where Δδ 2 H and Δδ 13 C are changes in isotope ratios during degradation) resulted in clearly different Λ C-H values: 28 ± 4 (oxidation), 0.7 ± 0.1 and 0.9 ± 0.1 (hydrolytic dehalogenation), and 1.76 ± 0.05 and 3.5 ± 0.1 (dihaloelimination). This result highlights the potential of this approach to identify 1,2-DCA degradation pathways in the field. In addition, distinct trends were also observed in a multi- (i.e., Δδ 2 H versus Δδ 37 Cl versus Δδ 13 C) isotope plot, which opens further possibilities for pathway identification in future field studies. This is crucial information to understand the mechanisms controlling natural attenuation of 1,2-DCA and to design appropriate strategies to enhance biodegradation.
Madan, Jesvin S; Gupta, Kanika; Chattarji, Sumantra; Bhattacharya, Aditi
2018-06-01
Stress is known to cause contrasting patterns of morphological and physiological plasticity in the hippocampus and amygdala. An obligatory cellular process underlying such neural changes is de novo translation and alterations in protein expression. Yet the nature of the translational response to stress in neurons remains largely unexplored. Even less is known about how glia are affected. Using a click-chemistry-based method to label the de novo proteome in live brain slices, we monitored translation in neurons and astrocytes of the basolateral amygdala (BLA) and dorsal hippocampal area CA3 (dCA3) in rats at different time-points after a single 2-hr exposure to immobilization stress. We observed enhancements in neuronal translation in both brain regions 1 hour after stress. This initial increase persisted in the BLA up to 10 days afterwards. In contrast, dCA3 neuronal translation gradually decreased to below control levels 10 days later. Translation profiles of dCA3 astrocytes followed timelines similar to neurons, but in BLA astrocytes translation peaked 1 day later and remained elevated 10 days later. Together our results demonstrate that stress causes an immediate upregulation of protein synthesis in both amygdalar and hippocampal neurons and astrocytes. However, these two areas eventually exhibit opposite temporal profiles of protein expression well after the end of stress. These findings identify new metrics of stress-induced plasticity at the level of cell-type specific proteomic landscape that may provide important insights into the molecular basis of the divergent temporal effects of stress across brain regions and biological scales. © 2018 Wiley Periodicals, Inc.
Prichard, David O; Byrne, Anne Marie; Murphy, James O; Reynolds, John V; O'Sullivan, Jacintha; Feighery, Ronan; Doyle, Brendan; Eldin, Osama Sharaf; Finn, Stephen P; Maguire, Aoife; Duff, Deirdre; Kelleher, Dermot P; Long, Aideen
2017-12-01
The fundamental mechanisms underlying erosive oesophagitis and subsequent development of Barrett's oesophagus (BO) are poorly understood. Here, we investigated the contribution of specific components of the gastric refluxate on adhesion molecules involved in epithelial barrier maintenance. Cell line models of squamous epithelium (HET-1A) and BO (QH) were used to examine the effects of bile acids on cell adhesion to extracellular matrix proteins (Collagen, laminin, vitronectin, fibronectin) and expression of integrin ligands (α 3 , α 4, α 5 , α 6 and α ν ). Experimental findings were validated in human explant oesophageal biopsies, a rat model of gastroesophageal reflux disease (GORD) and in patient tissue microarrays. The bile acid deoxycholic acid (DCA) specifically reduced adhesion of HET-1A cells to vitronectin and reduced cell-surface expression of integrin-α ν via effects on endocytic recycling processes. Increased expression of integrin-α v was observed in ulcerated tissue in a rat model of GORD and in oesophagitis and Barrett's intestinal metaplasia patient tissue compared to normal squamous epithelium. Increased expression of integrin-α ν was observed in QH BO cells compared to HET-1A cells. QH cells were resistant to DCA-mediated loss of adhesion and reduction in cell-surface expression of integrin-α ν . We demonstrated that a specific component of the gastric refluxate, DCA, affects the epithelial barrier through modulation of integrin α ν expression, providing a novel mechanism for bile acid-mediated erosion of oesophageal squamous epithelium and promotion of BO. Strategies aimed at preventing bile acid-mediated erosion should be considered in the clinical management of patients with GORD. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.
Lipoic acid inhibits cell proliferation of tumor cells in vitro and in vivo
Feuerecker, Benedikt; Pirsig, Sabine; Seidl, Christof; Aichler, Michaela; Feuchtinger, Annette; Bruchelt, Gernot; Senekowitsch-Schmidtke, Reingard
2012-01-01
Cancer cells convert glucose preferentially to lactate even in the presence of oxygen (aerobic glycolysis–Warburg effect). New concepts in cancer treatment aim at inhibition of aerobic glycolysis. Pyruvate dehydrogenase converts pyruvate to acetylCoA thus preventing lactate formation. Therefore, the aim of this study was to evaluate compounds that could activate pyruvate dehydrogenase in cancer cells. We investigated the effects of (R)-(+)-α-lipoic acid (LPA) and dichloroacetate (DCA), possible activators of pyruvate dehydrogenase, on suppression of aerobic glycolysis and induction of cell death. The neuroblastoma cell lines Kelly, SK-N-SH, Neuro-2a and the breast cancer cell line SkBr3 were incubated with different concentrations (0.1–30 mM) of LPA and DCA. The effects of both compounds on cell viability/proliferation (WST-1 assay), [18F]-FDG uptake, lactate production and induction of apoptosis (flow cytometric detection of caspase-3) were evaluated. Furthermore, NMRI nu/nu mice that had been inoculated s.c. with SkBr3 cells were treated daily for four weeks with LPA (i.p, 18.5 mg/kg) starting at day 7 p.i.. Tumor development was measured with a sliding calliper and monitored via [18F]-FDG-PET. Residual tumors after therapy were examined histopathologically. These data suggests that LPA can reduce (1) cell viability/proliferation, (2) uptake of [18F]-FDG and (3) lactate production and increase apoptosis in all investigated cell lines. In contrast, DCA was almost ineffective. In the mouse xenograft model with s.c. SkBr3 cells, daily treatment with LPA retarded tumor progression. Therefore, LPA seems to be a promising compound for cancer treatment. PMID:22954700
Sheng, Lili; Jena, Prasant Kumar; Hu, Ying; Liu, Hui-Xin; Nagar, Nidhi; Kalanetra, Karen M; French, Samuel William; French, Samuel Wheeler; Mills, David A; Wan, Yu-Jui Yvonne
2017-12-01
Dysregulated bile acid (BA) synthesis or reduced farnesoid X receptor (FXR) levels are found in patients having metabolic diseases, autoimmune hepatitis, and liver cirrhosis or cancer. The objective of this study was to establish the relationship between butyrate and dysregulated BA synthesis-induced hepatitis as well as the effect of butyrate in reversing the liver pathology. Wild-type (WT) and FXR knockout (KO) male mice were placed on a control (CD) or western diet (WD) for 15 months. In the presence or absence of butyrate supplementation, feces obtained from 15-month-old WD-fed FXR KO mice, which had severe hepatitis and liver tumors, were transplanted to 7-month-old WD-fed FXR KO for 3 months. Hepatic phenotypes, microbiota profile, and BA composition were analyzed. Butyrate-generating bacteria and colonic butyrate concentration were reduced due to FXR inactivation and further reduced by WD intake. In addition, WD-fed FXR KO male mice had the highest concentration of hepatic β-muricholic acid (β-MCA) and bacteria-generated deoxycholic acid (DCA) accompanied by serious hepatitis. Moreover, dysregulated BA and reduced SCFA signaling co-existed in both human liver cancers and WD-fed FXR KO mice. Microbiota transplantation using butyrate-deficient feces derived from 15-month-old WD-fed FXR KO mice increased hepatic lymphocyte numbers as well as hepatic β-MCA and DCA concentrations. Furthermore, butyrate supplementation reduced hepatic β-MCA as well as DCA and eliminated hepatic lymphocyte infiltration. In conclusion, reduced butyrate contributes to the development of hepatitis in the FXR KO mouse model. In addition, butyrate reverses dysregulated BA synthesis and its associated hepatitis. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Huang, Hsin-Yi; Chen, Po-Yu
2010-12-15
Nonenzymatic electrochemical determination of ethanol and glucose was respectively achieved using PdNi- and Pd-coated electrodes prepared by electrodeposition from the novel metal-free ionic liquid (IL); N-butyl-N-methylpyrrolidinium dicyanamide (BMP-DCA). BMP-DCA provided an excellent environment and wide cathodic limit for electrodeposition of metals and alloys because many metal chlorides could dissolve in this IL where the reduction potentials of Pd(II) and Ni(II) indeed overlapped, leading to the convenience of potentiostatic codeposition. In aqueous solutions, the reduction potentials of Pd(II) and Ni(II) are considerably separated. The bimetallic PdNi coatings with atomic ratios of ∼ 80/20 showed the highest current for ethanol oxidation reaction (EOR). Ethanol was detected by either cyclic voltammetry (CV) or hydrodynamic amperometry (HA). Using CV, the dependence of EOR peak current on concentration was linear from 4.92 to 962 μM with a detection limit of 2.26 μM (σ=3), and a linearity was observed from 4.92 to 988 μM using HA (detection limit 0.83 μM (σ=3)). The Pd-coated electrodes prepared by electrodeposition from BMP-DCA showed electrocatalytic activity to glucose oxidation and CV, HA, and square-wave voltammetry (SWV) were employed to determine glucose. SWV showed the best sensitivity and linearity was observed from 2.86 μM to 107 μM, and from 2.99 mM to 10.88 mM with detection limits of 0.78 μM and 25.9 μM (σ=3), respectively. For glucose detection, the interference produced from ascorbic acid, uric acid, and acetaminophen was significantly suppressed, compared with a regular Pt disk electrode. Copyright © 2010 Elsevier B.V. All rights reserved.
TRIAGE DOSE ASSESSMENT FOR PARTIAL-BODY EXPOSURE: DICENTRIC ANALYSIS
Moroni, Maria; Pellmar, Terry C.
2009-01-01
Partial-body biodosimetry is likely to be required after a radiological or nuclear exposure. Clinical signs and symptoms, distribution of dicentrics in circulating blood cells, organ-specific biomarkers, physical signals in teeth and nails all can provide indications of non-homogeneous exposures. Organ specific biomarkers may provide early warning regarding physiological systems at risk after radiation injury. Use of a combination of markers and symptoms will be needed for clinical insights for therapeutic approaches. Analysis of dicentrics, a marker specific for radiation injury, is the “Gold standard” of biodosimetry and can reveal partial-body exposures. Automation of sample processing for dicentric analysis can increase throughput with customization of off-the-shelf technologies for cytogenetic sample processing and information management. Automated analysis of the metaphase spreads is currently limited but improvements are in development. Our efforts bridge the technological gaps to allow the use of dicentric chromosome assay (DCA) for risk-based stratification of mass casualties. This article summarizes current knowledge on partial-body cytogenetic dose assessment synthesizing information leading to the proposal of an approach to triage dose prediction in radiation mass casualties, based on equivalent whole-body doses under partial-body exposure conditions and assesses the validity of using this model. An initial screening using only 20 metaphase spreads per subject can confirm irradiation above 2-Gy. A subsequent increase to 50 metaphases improves dose determination to allow risk stratification for clinical triage. Metaphases evaluated for inhomogeneous distribution of dicentrics can reveal partial-body exposures. We tested the validity of this approach in an in vitro model that simulates partial-body irradiation by mixing irradiated and un-irradiated lymphocytes in various proportions. Our preliminary results support the notion that this approach will be effective under a range of conditions including some partial-body exposures, but may have limitations with low doses or small proportions of irradiated body. Our studies address an important problem in the diagnosis of partial-body irradiation and dose assessment in mass casualties and propose a solution. However, additional work is needed to fully develop and validate the application of DCA to partial-body exposures. PMID:20065689
UPTAKE AND ELIMINATION OF DICHLOROACETIC ACID BY RAINBOW TROUT
Dichloroacetic acid (DCA) is a by-product of drinking water chlorination and is a hepatocarcinogen in rodents. Preliminary results of a chronic testing effort with Japanese medaka suggest the possibility of similar effects is fish. Adult rainbow trout were cannulated from the dor...
Early-life environmental factors can influence later-life susceptibility to cancer. Epigenetic changes serve as promising biomarkers for these latent effects. Previously, we reported that short-term postnatal exposure to dichloroacetic acid (DCA), a byproduct of drinking water ch...
Latent carcinogenicity of early-life exposure to dichloroacetic acid in mice
AbstractEnvironmental exposures occurring early in life may have an important influence on cancer risk later in life. Here we investigated carryover effects of young-adult exposure to dichloroacetic acid (DCA), a small molecule analog of pyruvate and low-level environmental cont...
76 FR 45313 - Petition for Waiver and Other Relief
Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-28
... passengers. The acquisition of AirTran will bring to DCA Southwest's brand recognition, passenger loyalty... brand recognition, passenger loyalty, and access to its route network, which together should have a... conditions discussed below, outweigh its potential harms. Standard of Review; Legal Authority Because the...
Separate elements of episodic memory subserved by distinct hippocampal-prefrontal connections.
Barker, Gareth R I; Banks, Paul J; Scott, Hannah; Ralph, G Scott; Mitrophanous, Kyriacos A; Wong, Liang-Fong; Bashir, Zafar I; Uney, James B; Warburton, E Clea
2017-02-01
Episodic memory formation depends on information about a stimulus being integrated within a precise spatial and temporal context, a process dependent on the hippocampus and prefrontal cortex. Investigations of putative functional interactions between these regions are complicated by multiple direct and indirect hippocampal-prefrontal connections. Here application of a pharmacogenetic deactivation technique enabled us to investigate the mnemonic contributions of two direct hippocampal-medial prefrontal cortex (mPFC) pathways, one arising in the dorsal CA1 (dCA1) and the other in the intermediate CA1 (iCA1). While deactivation of either pathway impaired episodic memory, the resulting pattern of mnemonic deficits was different: deactivation of the dCA1→mPFC pathway selectively disrupted temporal order judgments while iCA1→mPFC pathway deactivation disrupted spatial memory. These findings reveal a previously unsuspected division of function among CA1 neurons that project directly to the mPFC. Such subnetworks may enable the distinctiveness of contextual information to be maintained in an episodic memory circuit.
NASA Astrophysics Data System (ADS)
Lee, Ming-Tsung; Li, Yun-Shan; Sun, I.-Wen; Chang, Jeng-Kuei
2014-01-01
Ideal pseudocapacitive behavior of α-MnO2 electrodes over a potential range of 3 V is found in lithium bis(trifluoromethylsulfonyl)imide (LiTFSI)-doped butylmethylpyrrolidinium-dicyanamide (BMP-DCA) ionic liquid (IL), which is non-flammable and has a decomposition temperature of as high as ∼300 °C. Accordingly, this electrolyte is promising for high-energy, high-power, and high-safety supercapacitor applications. The addition of 0.01 M LiTFSI in the IL improves the oxide capacitance from 90 F g-1 to 120 F g-1, which is due to the incorporated Li+ ions promoting Mn valent state variation (between trivalent and tetravalent) during charge-discharge. However, excessive LiTFSI doping causes a capacitance decay due to reduced electrolyte ionic conductivity. In situ X-ray absorption spectroscopy is used to investigate the energy storage mechanism. A capacitance activation process of α-MnO2 in the Li+-doped BMP-DCA IL is found.
Natural attenuation of chlorinated hydrocarbons in a freshwater wetland
Lora, Michelle M.; Olsen, Lisa D.; Smith, Barrett L.; Alleman, Bruce C.; Leeson, Andrea
1997-01-01
Natural attenuation of chlorinated volatile organic compounds (VOC's) occurs as ground water discharges from a sand aquifer to a freshwater wetland at Aberdeen Proving Ground, Md. Field and laboratory results indicate that biotransformation in the anaerobic wetland sediments is an important attenuation process. Relatively high concentrations of the parent compounds trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (PCA) and low or undetectable concentrations of daughter products were measured in the aquifer. In contrast, relatively high concentrations of the daughter products cis- and trans-1,2-dichloroethylene (12DCE); vinyl chloride (VC); 1,1,2-trichloroethane (112TCA); and 1,2-dichloroethane (12DCA) were measured in ground water in the wetland sediments, although total VOC concentrations decreased upward from about 1 mu mol/L (micromoles per liter) at the base of the wetland sediments to less than 0.2 near the surface. Microcosm experiments showed that 12DCE and VC are produced from anaerobic degradation of both TCE and PCA; PCA degradation also produced 112TCA and 12DCA.
Drag Coefficient Estimation in Orbit Determination
NASA Astrophysics Data System (ADS)
McLaughlin, Craig A.; Manee, Steve; Lichtenberg, Travis
2011-07-01
Drag modeling is the greatest uncertainty in the dynamics of low Earth satellite orbits where ballistic coefficient and density errors dominate drag errors. This paper examines fitted drag coefficients found as part of a precision orbit determination process for Stella, Starlette, and the GEOSAT Follow-On satellites from 2000 to 2005. The drag coefficients for the spherical Stella and Starlette satellites are assumed to be highly correlated with density model error. The results using MSIS-86, NRLMSISE-00, and NRLMSISE-00 with dynamic calibration of the atmosphere (DCA) density corrections are compared. The DCA corrections were formulated for altitudes of 200-600 km and are found to be inappropriate when applied at 800 km. The yearly mean fitted drag coefficients are calculated for each satellite for each year studied. The yearly mean drag coefficients are higher for Starlette than Stella, where Starlette is at a higher altitude. The yearly mean fitted drag coefficients for all three satellites decrease as solar activity decreases after solar maximum.
Electrochemistry of sulfur and polysulfides in ionic liquids.
Manan, Ninie S A; Aldous, Leigh; Alias, Yatimah; Murray, Paul; Yellowlees, Lesley J; Lagunas, M Cristina; Hardacre, Christopher
2011-12-01
The electrochemistry of elemental sulfur (S(8)) and the polysulfides Na(2)S(4) and Na(2)S(6) has been studied for the first time in nonchloroaluminate ionic liquids. The cyclic voltammetry of S(8) in the ionic liquids is different to the behavior reported in some organic solvents, with two reductions and one oxidation peak observed. Supported by in situ UV-vis spectro-electrochemical experiments, the main reduction products of S(8) in [C(4)mim][DCA] ([C(4)mim] = 1-butyl-3-methylimidazolium; DCA = dicyanamide) have been identified as S(6)(2-) and S(4)(2-), and plausible pathways for the formation of these species are proposed. Dissociation and/or disproportionation of the polyanions S(6)(2-) and S(4)(2-) appears to be slow in the ionic liquid, with only small amounts of the blue radical species S(3)(•-) formed in the solutions at r.t., in contrast with that observed in most molecular solvents. © 2011 American Chemical Society
Cumulative Axial and Torsional Fatigue: An Investigation of Load-Type Sequencing Effects
NASA Technical Reports Server (NTRS)
Kalluri, Sreeramesh; Bonacuse, Peter J.
2000-01-01
Cumulative fatigue behavior of a wrought cobalt-base superalloy, Haynes 188 was investigated at 538 C under various single-step sequences of axial and torsional loading conditions. Initially, fully-reversed, axial and torsional fatigue tests were conducted under strain control at 538 C on thin-walled tubular specimens to establish baseline fatigue life relationships. Subsequently, four sequences (axial/axial, torsional/torsional, axial/torsional, and torsional/axial) of two load-level fatigue tests were conducted to characterize both the load-order (high/low) and load-type sequencing effects. For the two load-level tests, summations of life fractions and the remaining fatigue lives at the second load-level were computed by the Miner's Linear Damage Rule (LDR) and a nonlinear Damage Curve Approach (DCA). In general, for all four cases predictions by LDR were unconservative. Predictions by the DCA were within a factor of two of the experimentally observed fatigue lives for a majority of the cumulative axial and torsional fatigue tests.
NASA Astrophysics Data System (ADS)
Hooper, Justin B.; Smith, Grant D.; Bedrov, Dmitry
2013-09-01
Molecular dynamics (MD) simulations of mixtures of the room temperature ionic liquids (ILs) 1-butyl-4-methyl imidazolium [BMIM]/dicyanoamide [DCA] and [BMIM][NO3-] with HNO3 have been performed utilizing the polarizable, quantum chemistry based APPLE&P® potential. Experimentally it has been observed that [BMIM][DCA] exhibits hypergolic behavior when mixed with HNO3 while [BMIM][NO3-] does not. The structural, thermodynamic, and transport properties of the IL/HNO3 mixtures have been determined from equilibrium MD simulations over the entire composition range (pure IL to pure HNO3) based on bulk simulations. Additional (non-equilibrium) simulations of the composition profile for IL/HNO3 interfaces as a function of time have been utilized to estimate the composition dependent mutual diffusion coefficients for the mixtures. The latter have been employed in continuum-level simulations in order to examine the nature (composition and width) of the IL/HNO3 interfaces on the millisecond time scale.
Genetic structure of drone congregation areas of Africanized honeybees in southern Brazil.
Collet, Thais; Cristino, Alexandre Santos; Quiroga, Carlos Fernando Prada; Soares, Ademilson Espencer Egea; Del Lama, Marco Antônio
2009-10-01
As yet, certain aspects of the Africanization process are not well understood, for example, the reproductive behavior of African and European honeybees and how the first Africanized swarms were formed and spread. Drone congregation areas (DCAs) are the ideal place to study honeybee reproduction under natural conditions since hundreds of drones from various colonies gather together in the same geographical area for mating. In the present study, we assessed the genetic structure of seven drone congregations and four commercial European-derived and Africanized apiaries in southern Brazil, employing seven microsatellite loci for this purpose. We also estimated the number of mother-colonies that drones of a specific DCA originated from. Pairwise comparison failed to reveal any population sub-structuring among the DCAs, thus indicating low mutual genetic differentiation. We also observed high genetic similarity between colonies of commercial apiaries and DCAs, besides a slight contribution from a European-derived apiary to a DCA formed nearby. Africanized DCAs seem to have a somewhat different genetic structure when compared to the European.
Jing, Chu-Yu; Fu, Yi-Peng; Zheng, Su-Su; Yi, Yong; Shen, Hu-Jia; Huang, Jin-Long; Xu, Xin; Lin, Jia-Jia; Zhou, Jian; Fan, Jia; Ren, Zheng-Gang; Qiu, Shuang-Jian; Zhang, Bo-Heng
2017-01-01
Abstract Adjuvant transarterial chemoembolization (TACE) is a major option for postoperative hepatocellular carcinoma (HCC) patients with recurrence risk factors. However, individualized predictive models for subgroup of these patients are limited. This study aimed to develop a prognostic nomogram for patients with HCC underwent adjuvant TACE following curative resection. A cohort comprising 144 HCC patients who received adjuvant TACE following curative resection in the Zhongshan Hospital were analyzed. The nomogram was formulated based on independent prognostic indicators for overall survival (OS). The performance of the nomogram was evaluated by the concordance index (C-index), calibration curve, and decision curve analysis (DCA) and compared with the conventional staging systems. The results were validated in an independent cohort of 86 patients with the same inclusion criteria. Serum alpha-fetoprotein (AFP), hyper-sensitive C-reactive protein (hs-CRP), incomplete tumor encapsulation, and double positive staining of Cytokeratin 7 and Cytokeratin 19 on tumor cells were identified as independent predictors for OS. The C-indices of the nomogram for OS prediction in the training cohort and validation cohort were 0.787 (95%CI 0.775–0.799) and 0.714 (95%CI 0.695–0.733), respectively. In both the training and validation cohorts, the calibration plot showed good consistency between the nomogram-predicted and the observed survival. Furthermore, the established nomogram was superior to the conventional staging systems in terms of C-index and clinical net benefit on DCA. The proposed nomogram provided an accurate prediction on risk stratification for HCC patients underwent adjuvant TACE following curative resection. PMID:28296727
Ionic Liquid as a Solvent and Catalyst for Acylation of Maltodextrin
USDA-ARS?s Scientific Manuscript database
Catalyst-free esterification of maltodextrin was carried out in ionic liquid. Stearate esters of maltodextrin were obtained in various degree of substitution (DS) when vinyl stearate or stearic acid was heated with maltodextrin in ionic liquid, 1-butyl-3-methylimidazolium cyanamide (bmim[dca]). Re...
ASSESSING THE EFFECTS OF DICHLOROACETIC ACID (DCA) USING A MULTI-ENDPOINT MEDAKA ASSAY
In regulating the safety of water, EPA makes decisions on what chemical contaminants to regulate and at what levels. To make these decisions, the EPA needs hazard identification and dose-response information. Current rodent methods for generating required information have limita...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chang, Chiou-Shiung, E-mail: et000417@gmail.com; Department of Radiation Oncology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan; Hwang, Jing-Min
Stereotactic radiosurgery (SRS) is a well-established technique that is replacing whole-brain irradiation in the treatment of intracranial lesions, which leads to better preservation of brain functions, and therefore a better quality of life for the patient. There are several available forms of linear accelerator (LINAC)–based SRS, and the goal of the present study is to identify which of these techniques is best (as evaluated by dosimetric outcomes statistically) when the target is located adjacent to brainstem. We collected the records of 17 patients with lesions close to the brainstem who had previously been treated with single-fraction radiosurgery. In all, 5more » different lesion catalogs were collected, and the patients were divided into 2 distance groups—1 consisting of 7 patients with a target-to-brainstem distance of less than 0.5 cm, and the other of 10 patients with a target-to-brainstem distance of ≥ 0.5 and < 1 cm. Comparison was then made among the following 3 types of LINAC-based radiosurgery: dynamic conformal arcs (DCA), intensity-modulated radiosurgery (IMRS), and volumetric modulated arc radiotherapy (VMAT). All techniques included multiple noncoplanar beams or arcs with or without intensity-modulated delivery. The volume of gross tumor volume (GTV) ranged from 0.2 cm{sup 3} to 21.9 cm{sup 3}. Regarding the dose homogeneity index (HI{sub ICRU}) and conformity index (CI{sub ICRU}) were without significant difference between techniques statistically. However, the average CI{sub ICRU} = 1.09 ± 0.56 achieved by VMAT was the best of the 3 techniques. Moreover, notable improvement in gradient index (GI) was observed when VMAT was used (0.74 ± 0.13), and this result was significantly better than those achieved by the 2 other techniques (p < 0.05). For V{sub 4} {sub Gy} of brainstem, both VMAT (2.5%) and IMRS (2.7%) were significantly lower than DCA (4.9%), both at the p < 0.05 level. Regarding V{sub 2} {sub Gy} of normal brain, VMAT plans had attained 6.4 ± 5%; this was significantly better (p < 0.05) than either DCA or IMRS plans, at 9.2 ± 7% and 8.2 ± 6%, respectively. Owing to the multiple arc or beam planning designs of IMRS and VMAT, both of these techniques required higher MU delivery than DCA, with the averages being twice as high (p < 0.05). If linear accelerator is only 1 modality can to establish for SRS treatment. Based on statistical evidence retrospectively, we recommend VMAT as the optimal technique for delivering treatment to tumors adjacent to brainstem.« less
Seisen, Thomas; Colin, Pierre; Hupertan, Vincent; Yates, David R; Xylinas, Evanguelos; Nison, Laurent; Cussenot, Olivier; Neuzillet, Yann; Bensalah, Karim; Novara, Giacomo; Montorsi, Francesco; Zigeuner, Richard; Remzi, Mesut; Shariat, Shahrokh F; Rouprêt, Morgan
2014-11-01
To propose and validate a nomogram to predict cancer-specific survival (CSS) after radical nephroureterectomy (RNU) in patients with pT1-3/N0-x upper tract urothelial carcinoma (UTUC). The international and the French national collaborative groups on UTUC pooled data from 3387 patients treated with RNU. Only 2233 chemotherapy naïve pT1-3/N0-x patients were included in the present study. The population was randomly split into the development cohort (1563) and the external validation cohort (670). To build the nomogram, logistic regressions were used for univariable and multivariable analyses. Different models were generated. The most accurate model was assessed using Harrell's concordance index and decision curve analysis (DCA). Internal validation was then performed by bootstrapping. Finally, the nomogram was calibrated and externally validated in the external dataset. Of the 1563 patients in the nomogram development cohort, 309 (19.7%) died during follow-up from UTUC. The actuarial CSS probability at 5 years was 75.7% (95% confidence interval [CI] 73.2-78.6%). DCA revealed that the use of the best model was associated with benefit gains relative to prediction of CSS. The optimised nomogram included only six variables associated with CSS in multivariable analysis: age (P < 0.001), pT stage (P < 0.001), grade (P < 0.02), location (P < 0.001), architecture (P < 0.001) and lymphovascular invasion (P < 0.001). The accuracy of the nomogram was 0.81 (95% CI, 0.78-0.85). Limitations included the retrospective study design and the lack of a central pathological review. An accurate postoperative nomogram was developed to predict CSS after RNU only in locally and/or locally advanced UTUC without metastasis, where the decision for adjuvant treatment is controversial but crucial for the oncological outcome. © 2014 The Authors. BJU International © 2014 BJU International.
49 CFR 1562.23 - Aircraft operator and passenger requirements.
Code of Federal Regulations, 2014 CFR
2014-10-01
... United States. (vi) Alien registration number, if applicable. (3) Must successfully complete a TSA... naturalization if the individual is a naturalized citizen of the United States. (F) Alien registration number, if... crewmember on an aircraft operating into or out of DCA provides TSA with a valid government-issued picture...
49 CFR 1562.23 - Aircraft operator and passenger requirements.
Code of Federal Regulations, 2012 CFR
2012-10-01
... United States. (vi) Alien registration number, if applicable. (3) Must successfully complete a TSA... naturalization if the individual is a naturalized citizen of the United States. (F) Alien registration number, if... crewmember on an aircraft operating into or out of DCA provides TSA with a valid government-issued picture...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-11-15
... (ETA) sponsored information collection request (ICR) titled, ``Veterans Retraining Assistance... Officer for DOL- ETA, Office of Management and Budget, Room 10235, 725 17th Street NW., Washington, DC...(a)(1)(D). SUPPLEMENTARY INFORMATION: This ICR seeks continued PRA authorization for the ETA to...
Code of Federal Regulations, 2014 CFR
2014-07-01
... (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993... Debt Collection Act (DCA), 31 U.S.C. 3711 et seq., and, in addition to seeking recovery of the unpaid...
Code of Federal Regulations, 2012 CFR
2012-07-01
... (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993... Debt Collection Act (DCA), 31 U.S.C. 3711 et seq., and, in addition to seeking recovery of the unpaid...
Code of Federal Regulations, 2013 CFR
2013-07-01
... (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993... Debt Collection Act (DCA), 31 U.S.C. 3711 et seq., and, in addition to seeking recovery of the unpaid...
Code of Federal Regulations, 2011 CFR
2011-07-01
... (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993... Debt Collection Act (DCA), 31 U.S.C. 3711 et seq., and, in addition to seeking recovery of the unpaid...
Dichloroacetic Acid (DCA) is a major byproduct of the chlorine disinfection of humic acid containing drinking water sources. It is a hepatocarcinogen in mice and rats at exposure concentrations in drinking water that are at least 4 orders of magnitude above the concentrations in ...
At each of 60 sites, we collected benthic macroinvertebrates using six different protocols (including the EMAP methods for non-wadeable rivers) and physical habitat data using the USEPA-EMAP-SW protocols for non-wadeable rivers. We used PCA with physical habitat data and DCA wit...
ERIC Educational Resources Information Center
Blakely, Allison Wright
2017-01-01
The purpose of this study was to examine the relation between "district capacity" as measured by the District Capacity Assessment (DCA) and the "initial, depth, scale," and "sustained" implementation of an evidence-based practice (EBP), Positive Behavior Interventions and Supports (PBIS). This exploratory analysis…
Early-life environmental factors can influence later-life susceptibility to cancer. Recent evidence suggests that metabolic pathways may mediate this type of latency effect. Previously, we reported that short-term exposure to dichloroacetic acid (DCA) increased liver cancer in mi...
THE DISTRIBUTION OF EDB, BENZENE, AND 1,2-DCA AT GASOLINE SPILL SITES
With assistance from the Association of State and Territorial Air and Solid Waste Management Officials (ASTSWMO), the U.S. EPA Office of Underground Storage Tanks (OUST) and the U.S. EPA Office of Research and Development (ORD) conducted a survey to determine the distribution of ...
Field evidence from underground storage tank sites where leaded gasoline leaked indicates the lead scavengers 1,2- dibromoethane (ethylene dibromide, or EDB) and 1,2- dichloroethane (1,2-DCA) may be present in groundwater at levels that pose unacceptable risk. These compounds are...
EARLY GENE EXPRESSION CHANGES IN THE LIVERS OF MICE EXPOSED TO DICHOLORACETC ACID
EARLY GENE EXPRESSION CHANGES IN THE LIVERS OF MICE EXPOSED TO DICHLOROACETIC ACID
Dichloroacetic acid COCA) is a major by-product ofwater disinfection by cWorination. Several
studies have shown that DCA induces liver tumors in rodents when administered in drinkmg wate...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Audet, Chantal; Poffenbarger, Brett A.; Chang, Pauling
2011-11-15
Purpose: To evaluate a commercial volumetric modulated arc therapy (VMAT), using multiple noncoplanar arcs, for linac-based cranial radiosurgery, as well as evaluate the combined accuracy of the VMAT dose calculations and delivery. Methods: Twelve patients with cranial lesions of variable size (0.1-29 cc) and two multiple metastases patients were planned (Eclipse RapidArc AAA algorithm, v8.6.15) using VMAT (1-6 noncoplanar arcs), dynamic conformal arc (DCA, {approx}4 arcs), and IMRT (nine static fields). All plans were evaluated according to a conformity index (CI), healthy brain tissue doses and volumes, and the dose to organs at risk. A 2D dose distribution was measuredmore » (Varian Novalis Tx, HD120 MLC, 1000 MU/min, 6 MV beam) for the {approx}4 arc VMAT treatment plans using calibrated film dosimetry. Results: The CI (0-1 best) average for all plans was best for {approx}4 noncoplanar arc VMAT at 0.86 compared with {approx}0.78 for IMRT and a single arc VMAT and 0.68 for DCA. The volumes of healthy brain receiving 50% of the prescribed target coverage dose or more (V{sub 50%}) were lowest for the four arc VMAT [RA(4)] and DCA plans. The average ratio of the V{sub 50%} for the other plans to the RA(4) V{sub 50%} were 1.9 for a single noncoplanar arc VMAT [RA(1nc)], 1.4 for single full coplanar arc VMAT [RA(1f)] and 1.3 for IMRT. The V{sub 50%} improved significantly for single isocenter multiple metastases plan when two noncoplanar VMAT arcs were added to a full single coplanar one. The maximum dose to 5 cc of the outer 1 cm rim of healthy brain which one may want to keep below nonconsequential doses of 300-400 cGy, was 2-3 times greater for IMRT, RA(1nc) and RA(1f) plans compared with the multiple noncoplanar arc DCA and RA(4) techniques. Organs at risk near (0-4 mm) to targets were best spared by (i) single noncoplanar arcs when the targets are lateral to the organ at risk and (ii) by skewed nonvertical planes of IMRT fields when the targets are not lateral to the organ at risk. The highest dose gradient observed between an organ at risk and a target at the edge of a VMAT arc plane or plane of IMRT fields was 17%/mm. The average absolute percent difference between the measured and calculated central axis dose for all the VMAT plans was 3.6 {+-} 2.2%. The measured perpendicular profile widths and shifts were on average within 0.5 mm of planned values. The average total MUs for VMAT plans was double the DCA average and similar to the IMRT average. Conclusions: For the aforementioned planning and delivery system and cranial lesions greater than 7 mm in diameter, multiple noncoplanar arc VMAT consistently provides accurate and high quality cranial radiosurgery dose distributions with low doses to healthy brain tissue and high dose conformity to the target. These qualities may make multiple noncoplanar arc VMAT suitable for a greater range of prescription doses or larger and more irregular lesions. For smaller and/or rounder lesions there are other clinically acceptable treatment techniques that may involve fewer couch angles or arcs and reduce treatment times.« less
Fish communities of benchmark streams in agricultural areas of eastern Wisconsin
Sullivan, D.J.; Peterson, E.M.
1997-01-01
Fish communities were surveyed at 20 stream sites in agricultural areas in eastern Wisconsin in 1993 and 1995 as part of the National Water-Quality Assessment (NAWQA) Program. These streams, designated "benchmark streams," were selected for study because of their potential use as regional references for healthy streams in agricultural areas, based on aquatic communities, habitat, and water chemistry. The agricultural benchmark streams were selected from four physical settings, or relatively homogeneous units (RHU's), that differ in bedrock type, texture of surficial deposits, and land use. Additional data were collected along with the fish-community data, including measures of habitat, water chemistry, and population surveys of algae and benthic invertebrates. Of the 20 sites, 19 are classified as trout (salmonid) streams. Fish species that require cold or cool water were the most commonly collected. At least one species of trout was collected at 18 sites, and trout were the most abundant species at 13 sites. The species with the greatest collective abundance, and collected at 18 of the 20 sites, were mottled sculpin (Cottus bairdi), a coldwater species. The next most abundant species were brown trout (Salmo trutta), followed by brook trout (Salvelinusfontinalis), creek chub (Semotilus atromaculatus), and longnose dace (Rhinichthys cataractae). In all, 31 species of fish were collected. The number of species per stream ranged from 2 to 14, and the number of individuals collected ranged from 19 to 264. According to Index of Biotic Integrity (IBI) scores, 5 sites were rated excellent, 10 sites rated good, 4 rated fair, and 1 rated poor. The ratings of the five sites in the fair to poor range were low for various reasons. Two sites appeared to have more warmwater species than was ideal for a high-quality coldwater stream. One was sampled during high flow and the results may not be valid for periods of normal flow; the other may have been populated by migrating warmwater species. Two sites had insufficient deep-water habitat to support large numbers offish, especially top carnivores. Finally, one stream may be too cool to support enough warmwater species and too warm to support trout. In general, two methods of evaluating site habitat indicate that habitat is not a limiting factor for fish communities. However, two sites were rated as fair according to both habitat evaluation methods due to low base flow. Two sites rated below good according to one habitat evaluation method but rated good or excellent according to the other. Detrended correspondence analysis (DCA) of data for 17 sites showed three station groupings. These groupings fell along RHU divisions and each group was associated with one of three trout species. A species-richness gradient was evident on the station-ordination diagram. Intolerant species were associated with each grouping, a reflection of the generally high water quality at the sites. However, no significant differences were found between IBI scores or habitat indices among the site groupings. The DCA axis 1 and 2 scores correlated with average velocity and percent pool as well as RHU factors percent sandy surficial deposits, percent wetland, percent agriculture, and bedrock. Average velocity was highest at three sites which also had among the highest measured flow and largest drainage areas. Percent pool was generally lower at sites with smaller percentages of sandy surficial deposits, with one exception. The usefulness of ordination methods in conjunction with more traditional methods of defining biotic integrity (IB I) has been noted in previous studies. In this study, however, perhaps because of the relative homogeneity of the benchmark streams, the IBI did not correlate with the same kinds of factors as the DCA axis scores did.
Boegemann, Martin; Stephan, Carsten; Cammann, Henning; Vincendeau, Sébastien; Houlgatte, Alain; Jung, Klaus; Blanchet, Jean-Sebastien; Semjonow, Axel
2016-01-01
To prospectively test the diagnostic accuracy of the percentage of prostate specific antigen (PSA) isoform [-2]proPSA (%p2PSA) and the Prostate Health Index (PHI), and to determine their role for discrimination between significant and insignificant prostate cancer at initial and repeat prostate biopsy in men aged ≤65 years. The diagnostic performance of %p2PSA and PHI were evaluated in a multicentre study. In all, 769 men aged ≤65 years scheduled for initial or repeat prostate biopsy were recruited in four sites based on a total PSA (t-PSA) level of 1.6-8.0 ng/mL World Health Organization (WHO) calibrated (2-10 ng/mL Hybritech-calibrated). Serum samples were measured for the concentration of t-PSA, free PSA (f-PSA) and p2PSA with Beckman Coulter immunoassays on Access-2 or DxI800 instruments. PHI was calculated as (p2PSA/f-PSA × √t-PSA). Uni- and multivariable logistic regression models and an artificial neural network (ANN) were complemented by decision curve analysis (DCA). In univariate analysis %p2PSA and PHI were the best predictors of prostate cancer detection in all patients (area under the curve [AUC] 0.72 and 0.73, respectively), at initial (AUC 0.67 and 0.69) and repeat biopsy (AUC 0.74 and 0.74). t-PSA and %f-PSA performed less accurately for all patients (AUC 0.54 and 0.62). For detection of significant prostate cancer (based on Prostate Cancer Research International Active Surveillance [PRIAS] criteria) the %p2PSA and PHI equally demonstrated best performance (AUC 0.70 and 0.73) compared with t-PSA and %f-PSA (AUC 0.54 and 0.59). In multivariate analysis PHI we added to a base model of age, prostate volume, digital rectal examination, t-PSA and %f-PSA. PHI was strongest in predicting prostate cancer in all patients, at initial and repeat biopsy and for significant prostate cancer (AUC 0.73, 0.68, 0.78 and 0.72, respectively). In DCA for all patients the ANN showed the broadest threshold probability and best net benefit. PHI as single parameter and the base model + PHI were equivalent with threshold probability and net benefit nearing those of the ANN. For significant cancers the ANN was the strongest parameter in DCA. The present multicentre study showed that %p2PSA and PHI have a superior diagnostic performance for detecting prostate cancer in the PSA range of 1.6-8.0 ng/mL compared with t-PSA and %f-PSA at initial and repeat biopsy and for predicting significant prostate cancer in men aged ≤65 years. They are equally superior for counselling patients before biopsy. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.
Yamamoto, Shungo; Yamazaki, Shin; Shimizu, Tsunehiro; Takeshima, Taro; Fukuma, Shingo; Yamamoto, Yosuke; Tochitani, Kentaro; Tsuchido, Yasuhiro; Shinohara, Koh; Fukuhara, Shunichi
2015-04-28
The prognostic utility of serum C reactive protein (CRP) alone in sepsis is controversial. We used decision curve analysis (DCA) to evaluate the clinical usefulness of combining serum CRP levels with the CUBR-65 score in patients with suspected sepsis. Retrospective cohort study. Emergency department (ED) of an urban teaching hospital in Japan. Consecutive ED patients over 15 years of age who were admitted to the hospital after having a blood culture taken in the ED between 1 January 2010 and 31 December 2012. 30-day in-hospital mortality. Data from 1262 patients were analysed for score evaluation. The 30-day in-hospital mortality was 8.4%. Multivariable analysis showed that serum CRP ≥150 mg/L was an independent predictor of death (adjusted OR 2.0; 95% CI 1.3 to 3.1). We compared the predictive performance of CURB-65 with the performance of a modified CURB-65 with that included CRP (≥150 mg/L) to quantify the clinical usefulness of combining serum CRP with CURB-65. The areas under the receiver operating characteristics curves of CURB-65 and a modified CURB-65 were 0.76 (95% CI 0.72 to 0.80) and 0.77 (95% CI 0.72 to 0.81), respectively. Both models had good calibration for mortality and were useful among threshold probabilities from 0% to 30%. However, while incorporating CRP into CURB-65 yielded a significant category-free net reclassification improvement of 0.387 (95% CI 0.193 to 0.582) and integrated discrimination improvement of 0.015 (95% CI 0.004 to 0.027), DCA showed that CURB-65 and the modified CURB-65 score had comparable net benefits for prediction of mortality. Measurement of serum CRP added limited clinical usefulness to CURB-65 in predicting mortality in patients with clinically suspected sepsis, regardless of the source. 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.
Starfish (Asteroidea, Echinodermata) from the Faroe Islands; spatial distribution and abundance
NASA Astrophysics Data System (ADS)
Ringvold, H.; Andersen, T.
2016-01-01
"Marine benthic fauna of the Faroe Islands" (BIOFAR) is a large programme with a focus on collecting invertebrate fauna from the Faroes (62°N and 7°W). Cruises were undertaken from 1987 to 1990, and starfish (Asteroidea, Echinodermata) collected during this time were analysed. Asteroidea were sampled at ~50% of all BIOFAR stations. A Detritus sledge and a Triangular dredge proved to be the most efficient equipment, collecting over 60% of the specimens. In total 2473 specimens were collected from 20 to 1500 m depth, including 41 species from 17 families and 31 genera. Henricia pertusa (O. F. Müller, 1776) group, Pontaster tenuispinus (Düben & Koren, 1846), and Leptychaster arcticus (M. Sars, 1851) showed highest relative abundance. Maximum species diversity was found at 500-700 m depth, which coincides with the transition zone of water masses (North Icelandic Winter Water and Arctic Intermediate Water (NI/AI)) at approximately 400-600 m depth. 63% of the species were recorded at an average-weighted depth above 600 m. Two different ordination methods (detrended correspondence analysis (DCA) and nonmetric multidimensional scaling (NMDS)) gave highly consistent representations of the community structure gradients. The first ordination axis scores did not show significant relationships with any environmental variable. Biological covariates like the presence of Lophelia corals were not significantly related to ordination scores on any axis. The second ordination axis scores were significantly correlated with depth. Temperature and salinity were highly correlated (r=0.90), and both negatively correlated with depth (r=-0.69 and r=-0.57, respectively).
NASA Astrophysics Data System (ADS)
Liu, Zhichao; Zhao, Yunjie; Zeng, Chen; Computational Biophysics Lab Team
As the main protein of the bacterial flagella, flagellin plays an important role in perception and defense response. The newly discovered locus, FLS2, is ubiquitously expressed. FLS2 encodes a putative receptor kinase and shares many homologies with some plant resistance genes and even with some components of immune system of mammals and insects. In Arabidopsis, FLS2 perception is achieved by the recognition of epitope flg22, which induces FLS2 heteromerization with BAK1 and finally the plant immunity. Here we use both analytical methods such as Direct Coupling Analysis (DCA) and Molecular Dynamics (MD) Simulations to get a better understanding of the defense mechanism of FLS2. This may facilitate a redesign of flg22 or de-novo design for desired specificity and potency to extend the immune properties of FLS2 to other important crops and vegetables.
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76 FR 66965 - Treasure Coast Specialty Pharmacy Decision and Order
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2011-10-28
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USDA-ARS?s Scientific Manuscript database
Starch was acetylated with vinyl acetate in different 1-butyl-3-methylimidazolium (BMIM) salts as solvent in effort to produce starches with different acetylation patterns. Overall degree of substitution was much higher for basic anions such as acetate and dicyanimide (dca) than for neutral anions ...
The European Virtual Observatory EURO-VO | Euro-VO
: VOTECH EuroVO-DCA EuroVO-AIDA EuroVO-ICE The European Virtual Observatory EURO-VO The Virtual Observatory news Workshop on Virtual Observatory Tools and their Applications, Krakow, Poland June 16-18, organized present the Astronomical Virtual Observatory at the Copernicus (European Earth Observation Programme) Big
The chlorination of drinking water results in production of numerous disinfection by-products (DBPs). One of the important classes of DBPs is the haloacetic acids. We have previously shown that the haloacetic acids (HAs), dichloro (DCA), dibromo (DBA) and bromochloro (BCA) acetic...
Trichloroethylene (TCE) is an industrial solvent and a widespread environmental contaminant. Induction of liver cancer in mice by TCE is thought to be mediated by two metabolites, dichloroacetate (DCA) and trichloroacetate (TCA), both of which are themselves mouse liver carcinoge...
USDA-ARS?s Scientific Manuscript database
Consumption of a high fat diet causes an increase in bile acid deoxycholic acid (DCA) in colon lumen and colon cancer risk while butyrate, an intestinal microbiota metabolite of dietary fiber, has been shown to exhibit colon cancer preventive effects. To distinguish these opposing effects of D...
Brotton, Stephen J; Lucas, Michael; Chambreau, Steven D; Vaghjiani, Ghanshyam L; Yu, Jiang; Anderson, Scott L; Kaiser, Ralf I
2017-12-21
The production of the next generation of hypergolic, ionic-liquid-based fuels requires an understanding of the reaction mechanisms between the ionic liquid and oxidizer. We probed reactions between a levitated droplet of 1-methyl-4-amino-1,2,4-triazolium dicyanamide ([MAT][DCA]), with and without hydrogen-capped boron nanoparticles, and the nitrogen dioxide (NO 2 ) oxidizer. The apparatus exploits an ultrasonic levitator enclosed within a pressure-compatible process chamber equipped with complementary Raman, ultraviolet-visible, and Fourier-transform infrared (FTIR) spectroscopic probes. Vibrational modes were first assigned to the FTIR and Raman spectra of droplets levitated in argon. Spectra were subsequently collected for pure and boron-doped [MAT][DCA] exposed to nitrogen dioxide. By comparison with electronic structure calculations, some of the newly formed modes suggest that the N atom of the NO 2 molecule bonds to a terminal N on the dicyanamide anion yielding [O 2 N-NCNCN] - . This represents the first spectroscopic evidence of a key reaction intermediate in the oxidation of levitated ionic liquid droplets.
Chen, Hsiao-Fan; Gardner, Daniel M; Carmieli, Raanan; Wasielewski, Michael R
2013-10-07
Ordered multi-spin assemblies are required for developing solid-state molecule-based spintronics. A linear donor-chromophore-acceptor (D-C-A) molecule was covalently attached inside the 150 nm diam. nanopores of an anodic aluminum oxide (AAO) membrane. Photoexcitation of D-C-A in a 343 mT magnetic field results in sub-nanosecond, two-step electron transfer to yield the spin-correlated radical ion pair (SCRP) (1)(D(+)˙-C-A(-)˙), which then undergoes radical pair intersystem crossing (RP-ISC) to yield (3)(D(+)˙-C-A(-)˙). RP-ISC results in S-T0 mixing to selectively populate the coherent superposition states |S'> and |T'>. Microwave-induced transitions between these states and the unpopulated |T(+1)> and |T(-1)> states result in spin-polarized time-resolved EPR (TREPR) spectra. The dependence of the electron spin polarization (ESP) phase of the TREPR spectra on the orientation of the AAO membrane pores relative to the externally applied magnetic field is used to determine the overall orientation of the SCRPs within the pores at room temperature.
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Temporal binding function of dorsal CA1 is critical for declarative memory formation
Sellami, Azza; Al Abed, Alice Shaam; Brayda-Bruno, Laurent; Etchamendy, Nicole; Valério, Stéphane; Oulé, Marie; Pantaléon, Laura; Lamothe, Valérie; Potier, Mylène; Bernard, Katy; Jabourian, Maritza; Herry, Cyril; Mons, Nicole; Piazza, Pier-Vincenzo; Eichenbaum, Howard; Marighetto, Aline
2017-01-01
Temporal binding, the process that enables association between discontiguous stimuli in memory, and relational organization, a process that enables the flexibility of declarative memories, are both hippocampus-dependent and decline in aging. However, how these two processes are related in supporting declarative memory formation and how they are compromised in age-related memory loss remain hypothetical. We here identify a causal link between these two features of declarative memory: Temporal binding is a necessary condition for the relational organization of discontiguous events. We demonstrate that the formation of a relational memory is limited by the capability of temporal binding, which depends on dorsal (d)CA1 activity over time intervals and diminishes in aging. Conversely, relational representation is successful even in aged individuals when the demand on temporal binding is minimized, showing that relational/declarative memory per se is not impaired in aging. Thus, bridging temporal intervals by dCA1 activity is a critical foundation of relational representation, and a deterioration of this mechanism is responsible for the age-associated memory impairment. PMID:28874586
Fatigue Life Estimation under Cumulative Cyclic Loading Conditions
NASA Technical Reports Server (NTRS)
Kalluri, Sreeramesh; McGaw, Michael A; Halford, Gary R.
1999-01-01
The cumulative fatigue behavior of a cobalt-base superalloy, Haynes 188 was investigated at 760 C in air. Initially strain-controlled tests were conducted on solid cylindrical gauge section specimens of Haynes 188 under fully-reversed, tensile and compressive mean strain-controlled fatigue tests. Fatigue data from these tests were used to establish the baseline fatigue behavior of the alloy with 1) a total strain range type fatigue life relation and 2) the Smith-Wastson-Topper (SWT) parameter. Subsequently, two load-level multi-block fatigue tests were conducted on similar specimens of Haynes 188 at the same temperature. Fatigue lives of the multi-block tests were estimated with 1) the Linear Damage Rule (LDR) and 2) the nonlinear Damage Curve Approach (DCA) both with and without the consideration of mean stresses generated during the cumulative fatigue tests. Fatigue life predictions by the nonlinear DCA were much closer to the experimentally observed lives than those obtained by the LDR. In the presence of mean stresses, the SWT parameter estimated the fatigue lives more accurately under tensile conditions than under compressive conditions.
Genetic structure of drone congregation areas of Africanized honeybees in southern Brazil
2009-01-01
As yet, certain aspects of the Africanization process are not well understood, for example, the reproductive behavior of African and European honeybees and how the first Africanized swarms were formed and spread. Drone congregation areas (DCAs) are the ideal place to study honeybee reproduction under natural conditions since hundreds of drones from various colonies gather together in the same geographical area for mating. In the present study, we assessed the genetic structure of seven drone congregations and four commercial European-derived and Africanized apiaries in southern Brazil, employing seven microsatellite loci for this purpose. We also estimated the number of mother-colonies that drones of a specific DCA originated from. Pairwise comparison failed to reveal any population sub-structuring among the DCAs, thus indicating low mutual genetic differentiation. We also observed high genetic similarity between colonies of commercial apiaries and DCAs, besides a slight contribution from a European-derived apiary to a DCA formed nearby. Africanized DCAs seem to have a somewhat different genetic structure when compared to the European. PMID:21637465
Temporal binding function of dorsal CA1 is critical for declarative memory formation.
Sellami, Azza; Al Abed, Alice Shaam; Brayda-Bruno, Laurent; Etchamendy, Nicole; Valério, Stéphane; Oulé, Marie; Pantaléon, Laura; Lamothe, Valérie; Potier, Mylène; Bernard, Katy; Jabourian, Maritza; Herry, Cyril; Mons, Nicole; Piazza, Pier-Vincenzo; Eichenbaum, Howard; Marighetto, Aline
2017-09-19
Temporal binding, the process that enables association between discontiguous stimuli in memory, and relational organization, a process that enables the flexibility of declarative memories, are both hippocampus-dependent and decline in aging. However, how these two processes are related in supporting declarative memory formation and how they are compromised in age-related memory loss remain hypothetical. We here identify a causal link between these two features of declarative memory: Temporal binding is a necessary condition for the relational organization of discontiguous events. We demonstrate that the formation of a relational memory is limited by the capability of temporal binding, which depends on dorsal (d)CA1 activity over time intervals and diminishes in aging. Conversely, relational representation is successful even in aged individuals when the demand on temporal binding is minimized, showing that relational/declarative memory per se is not impaired in aging. Thus, bridging temporal intervals by dCA1 activity is a critical foundation of relational representation, and a deterioration of this mechanism is responsible for the age-associated memory impairment.
Study of morbidity of personnel with potential exposure to vinclozolin.
Zober, A; Hoffmann, G; Ott, M G; Will, W; Germann, C; van Ravenzwaay, B
1995-01-01
OBJECTIVES--To examine internal exposure and targeted health outcomes of employees exposed to 3-(3,5-dichlorophenyl)-5-methyl-5-vinyl-1,3-oxazolidine-2,4-dione; chemical abstracts service (CAS) number: 50471-44-8 (vinclozolin). METHODS--A cross sectional study of 67 men exposed to vinclozolin for one to 13 years during synthesis and formulation operations and 52 controls. Biomonitoring was based on determination of urinary metabolites that contained a 3,5-dichloroaniline (3,5-DCA) moiety. Targeted health endpoints were the same as in previous subchronic and chronic animal studies--namely, reversible changes in the concentrations of hormones of the adrenocorticotrophic and gonadotrophic feedback systems, signs of liver injury, haemolytic anaemia, cataract formation (uniquely in rats), and hormonally induced hyperplasia and tumours at high doses. The clinical investigation consisted of a medical and occupational history questionnaire, physical examination, laboratory determinations (including testosterone, LH, and FSH measurements), ultrasonography of the liver and prostate, a detailed eye examination, and routine spirometry. RESULTS--The mean 3,5-DCA concentration for two thirds of the study group exceeded an equivalent of the vinclozolin acceptable daily intake (ADI) used for consumer regulatory purposes. Even the highest concentrations were, however, at least 10 times below the no observable adverse effect level (NOAEL) based on animal studies. Analysis of physical examination and laboratory data provided no evidence of hormonal responses induced by vinclozolin. Furthermore, no evidence of liver injury, prostate changes, cataract formation, or haemolytic anaemia was found. CONCLUSION--There was no evidence of any health effects induced by vinclozolin among employees with potential long term exposure. In particular, no antiandrogenic effects were found. PMID:7795738
Martins, Lívia C; Diniz, José A P; Silva, Eliana V P; Barros, Vera L R S; Monteiro, Hamilton A O; Azevedo, Raimunda S S; Quaresma, Juarez A S; Vasconcelos, Pedro F C
2007-01-01
Minaçu virus was isolated from Ochlerotatus scapularis (Diptera: Culicidae) in Minaçu, Goiás State, Brazil, in 1996. In attempting characterization of virus serological (hemagluttination inhibition, HI; indirect immunofluorescence assay, IFA), physicochemical [test for deoxycholate acid (DCA) sensitivity; polyacrylamide gel electrophoresis (PAGE)] tests and ultrastructural studies were made. Virus was also assayed in suckling mice after intracerebral inoculation of 0.02 ml and in VERO and C6/36 cells with 0.1 ml of viral suspension containing 105 LD50/ml. Inoculated and control systems were observed daily. Every 24 h, one control and two inoculated animals were killed for tissue testing, including histopathological changes by haematoxylin and eosin (HE)-stained sections, which were semi-quantified. Research into viral antigen in the tissues of mice [central nervous system (CNS), liver, heart, lungs, spleen and kidneys] was carried out by the immunohistochemical technique using the peroxidase system. The virus only replicated in VERO cells, with antigen positive by IFA. Positive complement fixation tests were only obtained using antiserum of Minaçu virus. Minaçu virus is DCA resistant; haemagglutinating activity was negative. By electronic microscopy non-enveloped virus particles were 75 nm in diameter. PAGE analysis showed Minaçu virus genome profile with 10 RNA segments. Infected, non-killed animals died 7 days after inoculation. Tissue lesions were observed in all organs, except the lungs. Intense lesions were observed in the CNS and the heart, where neurone and cardiocyte necroses, respectively, were noted. The liver, spleen and kidneys had moderate tissue changes. Viral antigens were more abundant in the CNS and the heart, and absent in the lungs. In conclusion, Minaçu virus belongs to the family Reoviridae, genus Orbivirus. PMID:17244340
Self-assembled PEG monolayer based SPR immunosensor for label-free detection of insulin.
Gobi, K Vengatajalabathy; Iwasaka, Hiroyuki; Miura, Norio
2007-02-15
A simple and rapid continuous-flow immunosensor based on surface plasmon resonance (SPR) has been developed for detection of insulin as low as 1 ng ml-1 (ppb) with a response time of less than 5 min. At first, a heterobifunctional oligo(ethyleneglycol)-dithiocarboxylic acid derivative (OEG-DCA) containing dithiol and carboxyl end groups was used to functionalize the thin Au-film of SPR chip. Insulin was covalently bound to the Au-thiolate monolayer of OEG-DCA for activating the sensor surface to immunoaffinity interactions. An on-line competitive immunosensing principle is examined for detection of insulin, in which the direct affinity binding of anti-insulin antibody to the insulin on sensor surface is examined in the presence and absence of various concentrations of insulin. Immunoreaction of anti-insulin antibody with the sensor surface was optimized with reference to antibody concentration, sample analysis time and flow-rate to provide the desired detection limit and determination range. With the immunosensor developed, the lowest detectable concentration of insulin is 1 ng ml-1 and the determination range covers a wide concentration of 1-300 ng ml-1. The developed OEG-monolayer based sensor chip exhibited high resistance to non-specific adsorption of proteins, and an uninterrupted highly sensitive detection of insulin from insulin-impregnated serum samples has been demonstrated. After an immunoreaction cycle, active sensor surface was regenerated simply by a brief flow of an acidic buffer (glycine.HCl; pH 2.0) for less than 1 min. A same sensor chip was found reusable for more than 25 cycles without an appreciable change in the original sensor activity.
Yoo, Hong Sik; Bradford, Blair U.; Kosyk, Oksana; Shymonyak, Svitlana; Uehara, Takeki; Collins, Leonard B.; Bodnar, Wanda M.; Ball, Louise M.; Gold, Avram; Rusyn, Ivan
2014-01-01
Trichloroethylene (TCE) is a widely used organic solvent. Although TCE is classified as carcinogenic to humans, substantial gaps remain in our understanding of inter-individual variability in TCE metabolism and toxicity, especially in the liver. We tested a hypothesis that amounts of oxidative metabolites of TCE in mouse liver are associated with liver-specific toxicity. Oral dosing with TCE was conducted in sub-acute (600 mg/kg/d; 5 days; 7 inbred mouse strains) and sub-chronic (100 or 400 mg/kg/d; 1, 2, or 4 weeks; 2 inbred mouse strains) designs. We evaluated the quantitative relationship between strain-, dose-, and time-dependent formation of TCE metabolites from cytochrome P450-mediated oxidation [trichloroacetic acid (TCA), dichloroacetic acid (DCA), and trichloroethanol] and glutathione conjugation [S-(1,2-dichlorovinyl)-L-cysteine and S-(1,2-dichlorovinyl)glutathione] in serum and liver, and various liver toxicity phenotypes. In sub-acute study, inter-strain variability in TCE metabolite amounts was observed in serum and liver. No induction of Cyp2e1 protein levels in liver was detected. Serum and liver levels of TCA and DCA were correlated with increased transcription of peroxisome proliferator-marker genes Cyp4a10 and Acox1, but not with degree of induction in hepatocellular proliferation. In sub-chronic study, serum and liver levels of oxidative metabolites gradually decreased over time despite continuous dosing. Liver protein levels of Cyp2e1, Adh and Aldh2 were unaffected by treatment with TCE. While the magnitude of induction of peroxisome proliferator-marker genes also declined, hepatocellular proliferation increased. This study offers a unique opportunity to provide a scientific data-driven rationale for some of the major assumptions in human health assessment of TCE. PMID:25424544
Pacchioni, Andrea; Versaci, Francesco; Mugnolo, Antonio; Penzo, Carlo; Nikas, Dimitrios; Saccà, Salvatore; Favero, Luca; Agostoni, Pier Francesco; Garami, Zsolt; Prati, Francesco; Reimers, Bernhard
2013-09-10
To assess the incidence of silent cerebral embolization when using the transradial approach for diagnostic coronary angiography (DCA). Compared to other vascular access sites, the right transradial approach (RTA) could reduce the amount of brain emboli by avoiding mechanical trauma to the aortic wall caused by catheters and wire, whereas it increases manipulation of catheters in the ascending aorta and has a higher risk of direct embolization into the right common carotid artery. A recent study showed an increased incidence of microembolic signals (MES) in RTA compared to femoral. However, left transradial approach (LTA) has never been assessed. 40 patients with suspected coronary artery disease were randomized to DCA via RTA (n=20) or LTA (n=20) with contemporaneous bilateral transcranial Doppler monitoring. MES were detected in all patients, with a significantly higher rate in the RTA group (median 61, interquartile range (IQR) 47-105, vs 48, IQR 31-60, p=0.035). MES generated during procedures needing >2 catheters (n=8), are higher than those detected during procedures performed with 2 catheters (n=32, 102, IQR 70-108, vs 48, IQR 33-60, p=0.001). At multivariate analysis increasing number of catheters was the only independent predictor of high incidence of MES (OR 16.4, 95% CI 1.23-219.9, p=0.034, -2LL=26.7). LTA has a lower risk of brain embolization because of the lower number of catheter exchange maneuvers. Since the degree of brain embolism depends on the magnitude of mechanical manipulation, catheter changes should be minimized to reduce the risk of cerebral embolization. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
UDCA and CDCA alleviate 17α-ethinylestradiol-induced cholestasis through PKA-AMPK pathways in rats
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Xiaojiaoyang; Yuan, Zihang
Estrogen-induced cholestasis, known as intrahepatic cholestasis of pregnancy (ICP), is an estrogen-related liver disease that is widely recognized as female or pregnancy-specific. Our previous findings showed that the synthetic estrogen, 17α-ethinylestradiol (EE), induced cholestatic injury through ERK1/2-LKB1-AMP-activated protein kinase (AMPK) signaling pathway and its mediated suppression of farnesoid X receptor (FXR). To investigate the role played by bile acids in EE-induced cholestasis, we evaluated the effects of chenodeoxycholic acid (CDCA), ursodeoxycholic acid (UDCA) and deoxycholic acid (DCA) on sandwich cultured rat primary hepatocytes (SCRHs) and an in vivo rat model. Our results showed that, both CDCA and UDCA significantly inducedmore » time- and concentration-dependent reduction in AMPK phosphorylation in SCRHs. Despite having different effects on FXR activation, CDCA and UDCA both inhibited EE-induced AMPK activation, accompanied with the up-regulation of FXR and its downstream bile acid transporters. However, although DCA activates FXR and induces SHP, it was unable to alleviate EE-induced FXR suppression and further aggravated EE-induced cholestasis. We further demonstrated that both CDCA and UDCA, but not DCA, activated cyclic AMP dependent protein kinase (PKA) in SCRHs and the livers of male rats (8 weeks old) liver. Furthermore, PKA antagonist, H89, blocked the AMPK inhibition by CDCA and UDCA, and pharmacological and genetic activation of PKA suppressed EE-induced AMPK activation and its downstream effects. Collectively, these results suggest that CDCA and UDCA protect against estrogen-induced cholestatic injury via PKA signaling pathway and up-regulation of EE-suppressed FXR, which suggests a potential therapeutic target for ICP. - Highlights: • AMPK is involved in cholestatic liver injury with bile acid dysregulation. • CDCA and UDCA inhibit the phosphorylation of AMPK and alleviate estrogen-induced cholestasis. • PKA activation contributes to the CDCA- and UDCA-induced protective effects. • FXR up-regulation may be critical for improvement of cholestasis.« less
Peñalber, Chariz Y; Grenoble, Zlata; Baker, Gary A; Baldelli, Steven
2012-04-21
Advancement in the field of ionic liquid technology requires a comprehensive understanding of their surface properties, as a wide range of chemical reactions occur mainly at interfaces. As essential media currently used in several technological applications, their accurate molecular level description at the gas-liquid interface is of utmost importance. Due to the high degree of chemical information provided in the vibrational spectrum, vibrational spectroscopy gives the most detailed model for molecular structure. The inherently surface-sensitive technique, sum frequency generation (SFG) spectroscopy, in combination with bulk-sensitive vibrational spectroscopic techniques such as FTIR and Raman, has been used in this report to characterize the surface of cyano-containing ionic liquids, such as [BMIM][SCN], [BMIM][DCA], [BMIM][TCM] and [EMIM][TCB] at the gas-liquid interface. By structural variation of the anion while keeping the cation constant, emphasis on the molecular arrangement of the anion at the gas-liquid interface is reported, and its subsequent role (if any) in determining the surface molecular orientation of the cation. Vibrational modes seen in the C-H stretching region revealed the presence of the cation at the gas-liquid interface. The cation orientation is independent of the type of cyano-containing anion, however, a similar arrangement at the surface as reported in previous studies was found, with the imidazolium ring lying flat at the surface, and the alkyl chains pointing towards the gas phase. SFG results show that all three anions of varying symmetry, namely, [DCA](-) (C(2v)), [TCM](-)(D(3h)) and [TCB](-) (T(d)) in ionic liquids [BMIM]DCA], [BMIM][TCM] and [EMIM][TCB] are significantly tilted from the surface plane, while the linear [SCN](-) in [BMIM][SCN] exhibited poor ordering, as seen in the absence of its C-N stretching mode in the SFG vibrational spectra. This journal is © the Owner Societies 2012
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mitroka, J.G.
1989-01-01
Potential antidotes for human exposure to monochloroacetic acid (MCA) were evaluated using a rodent model. Dichloroacetic acid (DCA) and phenobarbital (PB) but not ethanol or phenytoin, were found to be effective antidotes to monochloroacetic acid (MCA) in rats. DCA (110 mg/kg, ip), administered to rats 15 minutes after a LD-80 of MCA (80 mg/kg, iv), consistently reduced mortality to 0%, while PB reduced mortality to less than 20%. Both DCA and PB were found to be similarly effective in mice. The hypothesis that PB reduces mortality in MCA treated rats by altering the metabolic disposition of MCA was evaluated andmore » rejected. Administration of PB to rats treated with a lethal dose of ({sup 14}C)MCA did not alter the concentrations of MCA or its metabolites in plasma or cerebrospinal fluid (CSF), or the extent of covalent binding between radioactivity equivalent to ({sup 14}C)MCA and brain proteins. The relationship between altered blood-brain barrier permeability and death in MCA treated rats was investigated. Treatment with MCA (80 mg/kg, iv) was associated with a significant (50%) increase in the permeability of the rat blood-brain barrier to ({sup 125}I)BSA. The effect was not altered by treatment with PB, however, suggesting that altered blood-brain barrier permeability does not have an important role in the lethal effect of MCA in rats. The effect of MCA on brain carbohydrate metabolism in vivo was investigated. CSF and blood lactic acid concentrations increased in MCA treated rats, and the increase in CSF levels was dose related. In individual MCA treated rats, CSF lactate concentrations paralleled the time course of ataxia and a discrete threshold for death (18 mmol/L) was observed. The relationship between excess brain lactate levels and death in MCA treated rats was investigated further.« less
Felício, Andréia Arantes; Freitas, Juliane Silberschmidt; Scarin, Jéssica Bolpeti; de Souza Ondei, Luciana; Teresa, Fabrício Barreto; Schlenk, Daniel; de Almeida, Eduardo Alves
2018-03-01
Diuron is one of the most used herbicide in the world, and its field application has been particularly increased in Brazil due to the expansion of sugarcane crops. Diuron has often been detected in freshwater ecosystems and it can be biodegraded into three main metabolites in the environment, the 3,4-dichloroaniline (DCA), 3,4-dichlorophenylurea (DCPU) and 3,4-dichlorophenyl-N-methylurea (DCPMU). Negative effects under aquatic biota are still not well established for diuron, especially when considering its presence in mixture with its different metabolites. In this study, we evaluated the effects of diuron alone or in combination with its metabolites, DCPMU, DCPU and 3,4-DCA on biochemical stress responses and biotransformation activity of the fish Oreochromis niloticus. Results showed that diuron and its metabolites caused significant but dispersed alterations in oxidative stress markers and biotransformation enzymes, except for ethoxyresorufin-O-deethylase (EROD) activity, that presented a dose-dependent increase after exposure to either diuron or its metabolites. Glutathione S-transferase (GST) activity was significant lower in gills after exposure to diuron metabolites, but not diuron. Diuron, DCPMU and DCA also decreased the multixenobiotic resistance (MXR) activity. Lipid peroxidation levels were increased in gill after exposure to all compounds, indicating that the original compound and diuron metabolites can induce oxidative stress in fish. The integration of all biochemical responses by the Integrated Biomarker Response (IBR) model indicated that all compounds caused significant alterations in O. niloticus, but DCPMU caused the higher alterations in both liver and gill. Our findings imply that diuron and its metabolites may impair the physiological response related to biotransformation and antioxidant activity in fish at field concentrations. Such alterations could interfere with the ability of aquatic animals to adapt to environments contaminated by agriculture. Copyright © 2017 Elsevier Inc. All rights reserved.
Shaw, Jiajiu; Wiegand, Richard; Wu, Jianmei; Bao, Xun; Valeriote, Frederick; Li, Jing
2015-06-01
UTL-5g is a novel small-molecule TNF-α inhibitor under investigation as both a chemoprotective and radioprotective agent. Animal studies showed that pretreatment of UTL-5g protected kidney, liver, and platelets from cisplatin-induced toxicity. In addition, UTL-5g reduced liver and lung injuries induced by radiation in vivo. Although a number of preclinical studies have been conducted, a validated bioanalytical method for UTL-5g in human plasma has not been published. In this work, a sensitive and reproducible reverse-phase liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) assay was developed and validated for the determination of UTL-5g and its metabolites, 5-methylisoxazole-3-carboxylic acid (ISOX) and 2,4-dichloroaniline (DCA), in human plasma. The method involves a simple methanol precipitation step followed by injection of the supernatant onto a Waters 2695 HPLC system coupled with a Waters Quattro Micro™ triple quadrupole mass spectrometer. Chromatographic separation was accomplished using a Waters Nova-Pak C18 column maintained at 30°C, running at gradient mode with mobile phase consisting of 0.1% formic acid in water and 0.1% formic acid in methanol at a flow rate of 0.2mL/min. The analytes were monitored under positive electrospray ionization (ESI). Quantitation of these compounds in plasma was linear from 0.05 to 10μM. The lower limit of quantitation (LLOQ) was 0.05, 0.1, and 0.2μM for UTL-5g, ISOX and DCA, respectively. The accuracy and intra-and inter-day precisions were within the generally accepted criteria for bioanalytical method (<15%). This method provides a practical tool to measure and characterize the plasma concentration-time profiles for UTL-5g and its metabolites, ISOX and DCA. Copyright © 2015 Elsevier B.V. All rights reserved.
Mathioni, Sandra M; Patel, Nrupali; Riddick, Bianca; Sweigard, James A; Czymmek, Kirk J; Caplan, Jeffrey L; Kunjeti, Sridhara G; Kunjeti, Saritha; Raman, Vidhyavathi; Hillman, Bradley I; Kobayashi, Donald Y; Donofrio, Nicole M
2013-01-01
Plants and animals have evolved a first line of defense response to pathogens called innate or basal immunity. While basal defenses in these organisms are well studied, there is almost a complete lack of understanding of such systems in fungal species, and more specifically, how they are able to detect and mount a defense response upon pathogen attack. Hence, the goal of the present study was to understand how fungi respond to biotic stress by assessing the transcriptional profile of the rice blast pathogen, Magnaporthe oryzae, when challenged with the bacterial antagonist Lysobacter enzymogenes. Based on microscopic observations of interactions between M. oryzae and wild-type L. enzymogenes strain C3, we selected early and intermediate stages represented by time-points of 3 and 9 hours post-inoculation, respectively, to evaluate the fungal transcriptome using RNA-seq. For comparative purposes, we also challenged the fungus with L. enzymogenes mutant strain DCA, previously demonstrated to be devoid of antifungal activity. A comparison of transcriptional data from fungal interactions with the wild-type bacterial strain C3 and the mutant strain DCA revealed 463 fungal genes that were down-regulated during attack by C3; of these genes, 100 were also found to be up-regulated during the interaction with DCA. Functional categorization of genes in this suite included those with roles in carbohydrate metabolism, cellular transport and stress response. One gene in this suite belongs to the CFEM-domain class of fungal proteins. Another CFEM class protein called PTH11 has been previously characterized, and we found that a deletion in this gene caused advanced lesion development by C3 compared to its growth on the wild-type fungus. We discuss the characterization of this suite of 100 genes with respect to their role in the fungal defense response.
A Tale of Two Systems: Education Reform in Washington D.C.
ERIC Educational Resources Information Center
Osborne, David
2015-01-01
An important contest is taking place in Washington, D.C.--a race between two vehicles designed to carry children into the future with the habits and skills they need to live productive, meaningful lives. The older of the two, the District of Columbia Public Schools (DCPS), uses a "unified governance model" that emerged more than a…
Scoping out the International Spy Museum
ERIC Educational Resources Information Center
Radosh, Ronald
2010-01-01
The International Spy Museum in Washington, D.C.--a private museum that opened in July 2002 at the cost of $40 million--is rated as one of the most visited and popular tourist destinations in the nation's capital, despite stiff competition from the various public museums that are part of the Smithsonian. The popularity of the Spy Museum has a…
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-30
... 10 p.m. to 10:59 p.m. no longer is a low demand period at Ronald Reagan Washington National Airport... Airport, LaGuardia Airport, O'Hare International Airport, Ronald Reagan Washington National Airport (DCA...-1024] High Density Traffic Airports; Notice of Determination Regarding Low Demand Periods at Ronald...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-21
... 6 a.m. to 6:59 a.m. no longer is a low demand period at Ronald Reagan Washington National Airport... Airport, LaGuardia Airport, O'Hare International Airport, Ronald Reagan Washington National Airport (DCA...-1024] High Density Traffic Airports; Notice of Determination Regarding Low Demand Periods at Ronald...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-24
... for the Reallocation of Slots at Ronald Reagan Washington National Airport and LaGuardia Airport... for the reallocation of slots at Ronald Reagan Washington National Airport and LaGuardia Airport... collectively to dispose of 16 slots at Ronald Reagan Washington National Airport (DCA) and 32 slots at LGA...
Tetra-ethyl lead was widely used in leaded automobile gasoline from 1923 until 1987. To prevent lead deposits from fouling the engine, 1,2-dibromoethane (EDB) and 1,2-dichloroethane (1,2-DCA) were added to the gasoline to act as lead scavengers. The Maximum Contaminant Levels...
Expanded Florida reef development during the mid-Pliocene warm period
NASA Astrophysics Data System (ADS)
Klaus, James S.; Meeder, John F.; McNeill, Donald F.; Woodhead, Jon F.; Swart, Peter K.
2017-05-01
The coral fauna of the Tamiami Formation documents a northern expansion of reef development along the Florida Peninsula during the mid-Pliocene warm period (MPWP). Radiometric dating (U-Pb) of Solenastrea bournoni produced an age of 2.99 ± 0.11 Ma, constraining reef development to the MPWP and the peak of Plio-Pleistocene faunal turnover; subsequent to the final closure of the Central American Seaway (CAS) but prior to major Northern Hemisphere Glaciation (NHG). Coral faunal analyses are based on a total of 1614 coral specimens collected along a 165 km stretch of the west Florida coast, and included rarefaction and detrended correspondence analysis (DCA). A total of 60 coral species occur within the Tamiami Formation, with faunal assemblages ranging from 42 to 87% extinct taxa. The Tamiami collections can be split into a southern "reef" assemblage with high diversity of stenotopic taxa and a northern "non-reef" assemblage with lower diversity eurytopic taxa. The southern reef assemblage contains framework buildups of the dominant tropical taxa Stylophora affinis, Orbicella annularis, and Acropora cervicornis. We interpret enhanced west Florida reef development during the middle Pliocene to be a product of more equitable sea surface temperatures, and reduced salinity fluctuations associated with higher sea levels. While mean sea surface temperature estimates based on oxygen isotopic analysis of the coral Solenastrea bournoni (25.3 °C) are similar to present day values (26 °C), a completely flooded southern Florida Platform in the Pliocene would be less prone to salinity fluctuations associated with coastal runoff and extreme cold-water events during winter storms. While higher latitude range shifts of tropical reef corals associated with current global climate change have been documented elsewhere in the world, we do not foresee the West Florida Shelf being conducive to significant range shifts in tropical coral taxa or reef development within the coming century.
Parra, N Andres; Orman, Amber; Padgett, Kyle; Casillas, Victor; Punnen, Sanoj; Abramowitz, Matthew; Pollack, Alan; Stoyanova, Radka
2017-01-01
This study aimed to develop an automated procedure for identifying suspicious foci of residual/recurrent disease in the prostate bed using dynamic contrast-enhanced-MRI (DCE-MRI) in prostate cancer patients after prostatectomy. Data of 22 patients presenting for salvage radiotherapy (RT) with an identified gross tumor volume (GTV) in the prostate bed were analyzed retrospectively. An unsupervised pattern recognition method was used to analyze DCE-MRI curves from the prostate bed. Data were represented as a product of a number of signal-vs.-time patterns and their weights. The temporal pattern, characterized by fast wash-in and gradual wash-out, was considered the "tumor" pattern. The corresponding weights were thresholded based on the number (1, 1.5, 2, 2.5) of standard deviations away from the mean, denoted as DCE1.0, …, DCE2.5, and displayed on the T2-weighted MRI. The resultant four volumes were compared with the GTV and maximum pre-RT prostate-specific antigen (PSA) level. Pharmacokinetic modeling was also carried out. Principal component analysis determined 2-4 significant patterns in patients' DCE-MRI. Analysis and display of the identified suspicious foci was performed in commercial software (MIM Corporation, Cleveland, OH, USA). In general, DCE1.0/DCE1.5 highlighted larger areas than GTV. DCE2.0 and GTV were significantly correlated (r = 0.60, p < 0.05). DCE2.0/DCA2.5 were also significantly correlated with PSA (r = 0.52, 0.67, p < 0.05). K trans for DCE2.5 was statistically higher than the GTV's K trans (p < 0.05), indicating that the automatic volume better captures areas of malignancy. A software tool was developed for identification and visualization of the suspicious foci in DCE-MRI from post-prostatectomy patients and was integrated into the treatment planning system.
Microbial based chlorinated ethene destruction
Bagwell, Christopher E [Aiken, SC; Freedman, David L [Clemson, SC; Brigmon, Robin L [North Augusta, SC; Bratt, William B [Atlanta, GA; Wood, Elizabeth A [Marietta, GA
2009-11-10
A mixed culture of Dehalococcoides species is provided that has an ability to catalyze the complete dechlorination of polychlorinated ethenes such as PCE, TCE, cDCE, 1,1-DCE and vinyl chloride as well as halogenated ethanes such as 1,2-DCA and EDB. The mixed culture demonstrates the ability to achieve dechlorination even in the presence of high source concentrations of chlorinated ethenes.
Edible Oil Barriers for Treatment of Chlorinated Solvent Contaminated Groundwater
2009-07-01
CF Chloroform Cl# Chlorine Number CO Carbon Monoxide CT Carbon Tetrachloride CVOC Chlorinated Volatile Organic Compound 1,2-DCA 1,2...As Safe HCl Hydrochloric Acid HRC® Hydrogen Release Compound IDW Investigation-Derived Waste ISCO In Situ Chemical Oxidation LEL Lower...Total Organic Carbon VC Vinyl Chloride VFA Volatile Fatty Acid VOC Volatile Organic Compound ZVI Zero Valent Iron viii ACKNOWLEDGEMENTS
Preparation and Physical Properties of Starch Stearates of Low to High Degree of Substitution
USDA-ARS?s Scientific Manuscript database
Starch stearates of degree of substitution (DS) 0.07-2.40 were prepared by heating dry starch and vinyl stearate in the ionic liquid BMIM dca at 75 Degrees C. Starch stearate of low DS (0.07) was insoluble in water but formed a gel and absorbed over seven times its weight of water. Starch stearate...
NASA Astrophysics Data System (ADS)
Boyce, Peter
1998-05-01
Congressman George Brown (D-CA) has agreed to speak. This should be a speech worth hearing. Known as one of the most thoughtful men in Congress, Representative Brown has been a longtime friend of science. He is currently the Ranking Minority Member of the House Science Committee. The meeting schedule has been rearranged to accommodate the Congressman's need to return to Washington for an important vote.
Airports, Hotel, and Ground Transportation Information | Division of Cancer Prevention
Airports in and near Washington, DC Reagan National (DCA) Approximate 30 minute drive from Rockville* Has its own Metro stop on the blue and yellow lines in Virginia NOTE: This airport may be the closest and easiest option if not renting a car or do not want to pay for an airport cab/shuttle. Dulles International (IAD) |
U.S.: proposed federal legislation to allow condom distribution and HIV testing in prison.
Dolinsky, Anna
2007-05-01
Representative Barbara Lee (D-CA) is reintroducing legislation in the U.S. House of Representatives that would require federal correctional facilities to allow community organizations to distribute condoms and provide voluntary counselling and testing for HIV and STDs for inmates. The bill has been referred to the House Judiciary Committee's Subcommittee on Crime, Terrorism, and Homeland Security.
Tolerance of anaerobic bacteria to chlorinated solvents.
Koenig, Joanna C; Groissmeier, Kathrin D; Manefield, Mike J
2014-01-01
The aim of this research was to evaluate the effects of four chlorinated aliphatic hydrocarbons (CAHs), perchloroethene (PCE), carbon tetrachloride (CT), chloroform (CF) and 1,2-dichloroethane (1,2-DCA), on the growth of eight anaerobic bacteria: four fermentative species (Escherichia coli, Klebsiella sp., Clostridium sp. and Paenibacillus sp.) and four respiring species (Pseudomonas aeruginosa, Geobacter sulfurreducens, Shewanella oneidensis and Desulfovibrio vulgaris). Effective concentrations of solvents which inhibited growth rates by 50% (EC50) were determined. The octanol-water partition coefficient or log Po/w of a CAH proved a generally satisfactory measure of its toxicity. Most species tolerated approximately 3-fold and 10-fold higher concentrations of the two relatively more polar CAHs CF and 1,2-DCA, respectively, than the two relatively less polar compounds PCE and CT. EC50 values correlated well with growth rates observed in solvent-free cultures, with fast-growing organisms displaying higher tolerance levels. Overall, fermentative bacteria were more tolerant to CAHs than respiring species, with iron- and sulfate-reducing bacteria in particular appearing highly sensitive to CAHs. These data extend the current understanding of the impact of CAHs on a range of anaerobic bacteria, which will benefit the field of bioremediation.
High accuracy satellite drag model (HASDM)
NASA Astrophysics Data System (ADS)
Storz, M.; Bowman, B.; Branson, J.
The dominant error source in the force models used to predict low perigee satellite trajectories is atmospheric drag. Errors in operational thermospheric density models cause significant errors in predicted satellite positions, since these models do not account for dynamic changes in atmospheric drag for orbit predictions. The Air Force Space Battlelab's High Accuracy Satellite Drag Model (HASDM) estimates and predicts (out three days) a dynamically varying high-resolution density field. HASDM includes the Dynamic Calibration Atmosphere (DCA) algorithm that solves for the phases and amplitudes of the diurnal, semidiurnal and terdiurnal variations of thermospheric density near real-time from the observed drag effects on a set of Low Earth Orbit (LEO) calibration satellites. The density correction is expressed as a function of latitude, local solar time and altitude. In HASDM, a time series prediction filter relates the extreme ultraviolet (EUV) energy index E10.7 and the geomagnetic storm index a p to the DCA density correction parameters. The E10.7 index is generated by the SOLAR2000 model, the first full spectrum model of solar irradiance. The estimated and predicted density fields will be used operationally to significantly improve the accuracy of predicted trajectories for all low perigee satellites.
High accuracy satellite drag model (HASDM)
NASA Astrophysics Data System (ADS)
Storz, Mark F.; Bowman, Bruce R.; Branson, Major James I.; Casali, Stephen J.; Tobiska, W. Kent
The dominant error source in force models used to predict low-perigee satellite trajectories is atmospheric drag. Errors in operational thermospheric density models cause significant errors in predicted satellite positions, since these models do not account for dynamic changes in atmospheric drag for orbit predictions. The Air Force Space Battlelab's High Accuracy Satellite Drag Model (HASDM) estimates and predicts (out three days) a dynamically varying global density field. HASDM includes the Dynamic Calibration Atmosphere (DCA) algorithm that solves for the phases and amplitudes of the diurnal and semidiurnal variations of thermospheric density near real-time from the observed drag effects on a set of Low Earth Orbit (LEO) calibration satellites. The density correction is expressed as a function of latitude, local solar time and altitude. In HASDM, a time series prediction filter relates the extreme ultraviolet (EUV) energy index E10.7 and the geomagnetic storm index ap, to the DCA density correction parameters. The E10.7 index is generated by the SOLAR2000 model, the first full spectrum model of solar irradiance. The estimated and predicted density fields will be used operationally to significantly improve the accuracy of predicted trajectories for all low-perigee satellites.
Tolerance of Anaerobic Bacteria to Chlorinated Solvents
Koenig, Joanna C.; Groissmeier, Kathrin D.; Manefield, Mike J.
2014-01-01
The aim of this research was to evaluate the effects of four chlorinated aliphatic hydrocarbons (CAHs), perchloroethene (PCE), carbon tetrachloride (CT), chloroform (CF) and 1,2-dichloroethane (1,2-DCA), on the growth of eight anaerobic bacteria: four fermentative species (Escherichia coli, Klebsiella sp., Clostridium sp. and Paenibacillus sp.) and four respiring species (Pseudomonas aeruginosa, Geobacter sulfurreducens, Shewanella oneidensis and Desulfovibrio vulgaris). Effective concentrations of solvents which inhibited growth rates by 50% (EC50) were determined. The octanol-water partition coefficient or log Po/w of a CAH proved a generally satisfactory measure of its toxicity. Most species tolerated approximately 3-fold and 10-fold higher concentrations of the two relatively more polar CAHs CF and 1,2-DCA, respectively, than the two relatively less polar compounds PCE and CT. EC50 values correlated well with growth rates observed in solvent-free cultures, with fast-growing organisms displaying higher tolerance levels. Overall, fermentative bacteria were more tolerant to CAHs than respiring species, with iron- and sulfate-reducing bacteria in particular appearing highly sensitive to CAHs. These data extend the current understanding of the impact of CAHs on a range of anaerobic bacteria, which will benefit the field of bioremediation. PMID:24441515
Food matrix and cooking process affect mineral bioaccessibility of enteral nutrition formulas.
Galán, María Gimena; Drago, Silvina Rosa
2014-02-01
When enteral formulas (EF) are administered orally as a supplement to the normal diet, they are often mixed with conventional foods or included in recipes in order to seek new flavors and textures and avoid monotony. The aims of this work were to study the bioaccessibility of Fe, Zn and Ca from commercial EF and the impact upon their incorporation into sweet preparations. Twenty commercial EF, before and after inclusion in sweet food (rice pudding, RP; banana smoothie, BS; tea, T; chocolate dessert, CD) were evaluated regarding Fe, Zn and Ca dialyzability (%DFe , %DZn , %DCa ) as an estimator of mineral bioaccessibility. Fe, Zn and Ca dialyzability from EF was variable and generally low. Heating during EF-sweet food preparation (T and CD) lowered values to 44.1 %DFe , possibly due to degradation of vitamin C, and 52.7 %DZn and 25.3 %DCa , due to the interaction with food components. EF and EF-sweet foods did not represent a good supply of Fe, Zn and Ca as recommended. This study demonstrated how the bioaccessibility of these minerals is affected by the food matrix in which EF is included as well as heating during food preparation. © 2013 Society of Chemical Industry.
Herbicide mitigation in microcosms simulating stormwater basins subject to polluted water inputs.
Bois, P; Huguenot, D; Jézéquel, K; Lollier, M; Cornu, J Y; Lebeau, T
2013-03-01
Non-point source pollution as a result of wine-growing activity is of high concern. Stormwater basins (SWB) found downstream of vineyard watersheds could show a potential for the mitigation of runoff water containing herbicides. In this study, mitigation of vinery-used herbicides was studied in microcosms with a very similar functioning to that recorded in SWB. Mitigation efficiency of glyphosate, diuron and 3,4-dichloroaniline (3,4-DCA) was investigated by taking into account hydraulic flow rate, mitigation duration, bioaugmentation and plant addition. Mitigation efficiency measured in water ranged from 63.0% for diuron to 84.2% for 3,4-DCA and to 99.8% for glyphosate. Water-storage duration in the SWB and time between water supplies were shown to be the most influential factors on the mitigation efficiency. Six hours water-storage duration allowed an efficient sorption of herbicides and their degradation by indigenous microorganisms in 5 weeks. Neither bioaugmentation nor plant addition had a significant effect on herbicide mitigation. Our results show that this type of SWB are potentially relevant for the mitigation of these herbicides stemming from wine-growing activity, providing a long enough hydraulic retention time. Copyright © 2012 Elsevier Ltd. All rights reserved.
Römpp, A; Klemm, O; Fricke, W; Frank, H
2001-04-01
Atmospheric haloacetates can arise from photochemical degradation of halogenated hydrocarbons and from direct anthropogenic emissions. Furthermore, there is also evidence of natural sources although these are quantitatively uncertain. As haloacetates are highly soluble in water, hydrometeors are most significant for their deposition. Fogwater (96 samples) and rainwater samples (over 100 samples) were collected from July 1998 to March 1999 at an ecological research site in northeastern Bavaria, Germany. They were analyzed for monofluoroacetate (MFA), difluoroacetate (DFA), trifluoroacetate (TFA), monochloroacetate (MCA), dichloroacetate (DCA), trichloroacetate (TCA), monobromoacetate (MBA), and dibromoacetate (DBA). The major inorganic ions were also determined. High concentrations of up to 11 microg/L MCA, 5 microg/L DCA, 2 microg/L TCA, and 2 microg/L TFA were found in fogwater associated with westerly winds. Backward trajectories were calculated to determine the origin of the air masses. MBA and DBA have highest concentrations in fogwater advected with air originating from the Atlantic, suggesting the marine origin of these two compounds. All analyzed substances show higher average concentrations in fog than in rain. Estimates of the deposition of haloacetates suggest that the contribution of fog may be more important than rain for the total burden of a forest ecosystem.
Bowen, Christopher H; Bonin, Jeff; Kogler, Anna; Barba-Ostria, Carlos; Zhang, Fuzhong
2016-03-18
In search of sustainable approaches to plastics production, many efforts have been made to engineer microbial conversions of renewable feedstock to short-chain (C2-C8) bifunctional polymer precursors (e.g., succinic acid, cadaverine, 1,4-butanediol). Less attention has been given to medium-chain (C12-C14) monomers such as ω-hydroxy fatty acids (ω-OHFAs) and α,ω-dicarboxylic acids (α,ω-DCAs), which are precursors to high performance polyesters and polyamides. Here we engineer a complete microbial conversion of glucose to C12 and C14 ω-OHFAs and α,ω-DCAs, with precise control of product chain length. Using an expanded bioinformatics approach, we screen a wide range of enzymes across phyla to identify combinations that yield complete conversion of intermediates to product α,ω-DCAs. Finally, through optimization of culture conditions, we enhance production titer of C12 α,ω-DCA to nearly 600 mg/L. Our results indicate potential for this microbial factory to enable commercially relevant, renewable production of C12 α,ω-DCA-a valuable precursor to the high-performance plastic, nylon-6,12.
NASA Astrophysics Data System (ADS)
Din, Abdullah Muhaimin Mohammad; Yaakop, Salmah; Hazmi, Izfa Riza
2015-09-01
Dung beetles has known for its bioindicator characteristic. Sensitive towards forest disturbance, dung beetles population and diversity will be less in disturbed and modified area. The objective of this study is to evaluate the diversity and distribution of dung beetles in different type of ecosystems in Peninsular Malaysia. Fifteen baited pitfall traps aligned in three transects were used in this study. Samples were collected after 24 h and repeated three time collections and identified afterwards. Two ecosystem types were selected, which are forested and agricultural ecosystem (livestock and plantation). A total of 4249 individuals, 47 species, in 11 genera was successfully collected from all localities. The H' index for Fraser Hill, Langkawi, Bangi Reserve Forest, Selangor (HSB), Sungkai Reserve Forest, Perak (SRF), Chini Lake, Bera Lake, chicken farm, goat farm, Longan plantation, and palm oil plantation were 1.58, 1.74, 2.17, 2.63, 1.80, 1.52, 1.63, 0.46, 0.00 and 1.98 respectively.Forest ecosystem, SRF shows the highest abundance (1486 individuals) and diversity, while for agricultural ecosystem,palm oil plantation shows the highest with 273 individuals and 16 species. Based onDetrended Correspondence Analysis (DCA) shows two groups that separate forest ecosystem with the agricultural ecosystem, with palm oil is the nearest to the forest. Palm oil ecosystem can sustain a dung beetles population due to the area can provide the requirements for the dung beetles to survive, such as food which comes from local domestic cows, shade from sunlight provide by the palm oil trees, and ground cover from small plants and shrubs.Even though modified ecosystem should have lower diversity of dung beetles, but some factors must be measured as well in order to have a better point of view.
Countering Air and Missile Threats
2012-03-23
information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources , gathering... apportionment guidance by the JFC. Functional component commands serve to ease the burden on the theater and joint task force staffs, free the JFC to focus...action (COA) to attain the desired objectives. Counterair requires a combination of OCA and DCA operations based on the JFC’s air apportionment
2006-12-01
CDM Camp Dresser & McKee Inc. CSU Colorado State University DCA dichloroethane DO dissolved oxygen DoD Department of Defense EA EA...Ph.D. (PI), Camp Dresser & McKee Inc. (CDM); John Eisenbeis, Ph.D., CDM; Kristy Warren, CDM; Dan Adams, CDM; Michael Allen, Bangor Naval Submarine Base...alcohol (PVA) using cyanuric chloride, and the resulting product was cross -linked with glutaraldehyde in presence of HCl to form a hydrogel that was
40 CFR 180.274 - Propanil; tolerances for residues.
Code of Federal Regulations, 2012 CFR
2012-07-01
... (3, 4-DCA) in or on the following food commodities: Commodity Parts per million Cattle, fat 0.10 Cattle, meat 0.05 Cattle, meat byproducts 1.0 Crayfish 0.05 Egg 0.30 Goat, fat 0.10 Goat, meat 0.05 Goat, meat byproducts 1.0 Hog, fat 0.10 Hog, meat 0.05 Hog, meat byproducts 1.0 Horse, fat 0.10 Horse, meat 0...
40 CFR 180.274 - Propanil; tolerances for residues.
Code of Federal Regulations, 2014 CFR
2014-07-01
... (3, 4-DCA) in or on the following food commodities: Commodity Parts per million Cattle, fat 0.10 Cattle, meat 0.05 Cattle, meat byproducts 1.0 Crayfish 0.05 Egg 0.30 Goat, fat 0.10 Goat, meat 0.05 Goat, meat byproducts 1.0 Hog, fat 0.10 Hog, meat 0.05 Hog, meat byproducts 1.0 Horse, fat 0.10 Horse, meat 0...
40 CFR 180.274 - Propanil; tolerances for residues.
Code of Federal Regulations, 2013 CFR
2013-07-01
... (3, 4-DCA) in or on the following food commodities: Commodity Parts per million Cattle, fat 0.10 Cattle, meat 0.05 Cattle, meat byproducts 1.0 Crayfish 0.05 Egg 0.30 Goat, fat 0.10 Goat, meat 0.05 Goat, meat byproducts 1.0 Hog, fat 0.10 Hog, meat 0.05 Hog, meat byproducts 1.0 Horse, fat 0.10 Horse, meat 0...
ERIC Educational Resources Information Center
Phillip, Jendayi
2012-01-01
The Real Education for Healthy Youth Act (S. 1782/H.R. 3324), introduced in November 2011 by Senator Frank Lautenberg (D-NJ) and Representative Barbara Lee (D-CA), would ensure that federal funding is allocated to comprehensive sexual health education programs that provide young people with the skills and information they need to make informed,…
Carbajal-Hernández, Ana Laura; Valerio-García, Roberto Carlos; Martínez-Ruíz, Erika Berenice; Jarquín-Díaz, Víctor Hugo; Martínez-Jerónimo, Fernando
2017-07-01
Chapalichthys pardalis is a viviparous fish, microendemic to the Tocumbo Region in the state of Michoacán, Mexico. Despite the peculiar type of reproduction of goodeid fish and their mother-embryo interaction, the effects on embryos induced by maternal exposure to aquatic xenobiotics are still unknown. The objective of the present work was to determine the maternal-embryonic metabolic and antioxidant response of C. pardalis exposed to 3,4-dichloroaniline (3,4-DCA), a compound considered highly noxious to the environment because of its high toxicity and persistence, which has been used as reference toxicant in toxicological bioassays. We determined the median lethal concentration (LC 50 , 96 h) and then exposed pregnant females to 3.3, 2.5, and 0.5 mg L -1 of 3,4-DCA (equivalent to LC 1 , LC 0.01 , and LC 50/10 , respectively) during 21 days. We assessed the activity of antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), macromolecules content (proteins, lipids, carbohydrates), glucose, and lactate concentration, as well as the oxidative damage, by measuring thiobarbituric acid reactive substances, and protein oxidation. To interpret results, we used the integrated biomarker response (IBRv2). The average LC 50 was of 5.18 mg L -1 (4.8-5.5 mg L -1 ; p = 0.05). All females exposed to concentrations of 3.3 and 2.5 mg L -1 lost 100% of the embryos during the bioassay, whereas those exposed to 0.5 mg L -1 showed alterations in the antioxidant activity and oxidative damage, being the embryos and the maternal liver the most affected, with IBRv2 values of 10.09 and 9.21, respectively. Damage to macromolecules was greater in embryos and the maternal liver, with IBRv2 of 16.14 and 8.40, respectively. We conclude that exposure to xenobiotics, like 3,4-DCA, in species with a marked maternal-embryonic interaction represents a potential risk for the development and survival of the descendants, thereby, potentially affecting the future of the population.
Swartz, Kenneth; Zhang, Yiguan; Valeriote, Frederick; Chen, Ben; Shaw, Jiajiu
2013-12-01
UTL-5g is a novel small-molecule chemoprotector that lowers hepatotoxicity, nephrotoxicity, and myelotoxicity induced by cisplatin through TNF-α inhibition among other factors. As a prelude to investigating the metabolites of UTL-5g, we set out to identify the enzymatic products of UTL-5g under the treatment of both porcine liver esterase (PLE) and rabbit liver esterase (RLE). First, a number of mixtures made by UTL-5g and PLE were incubated at 25°C. At predetermined time points, individual samples were quenched by acetonitrile, vortexed, and centrifuged. The supernatants were then analyzed by reversed-phase HPLC (using a C18 column). The retention times and UV/vis spectra of individual peaks were compared to those of UTL-5g and its two postulated enzymatic products; thus the enzymatic products of UTL-5g were tentatively identified. Secondly, a different HPLC method (providing different retentions times) was used to cross-check and to confirm the identities of the two enzymatic products. Based on the observations, it was concluded that under the treatment of PLE, the major enzymatic products of UTL-5g were 5-methyliosxazole-3-carboxylic acid (ISOX) and 2,4-dichloroaniline (DCA). Treatment of UTL-5g by RLE also provided the same enzymatic products of UTL-5g from esterase. These results indicate that the peptide bond in UTL-5g was cleaved by PLE/RLE. Michaelis-Menten kinetics showed that the Km values of UTL-5g were 2.07mM with PLE and 0.37mM with RLE indicating that UTL-5g had a higher affinity with RLE. In summary, by a simple HPLC approach, we have concluded that the peptide bond in UTL-5g was cleaved by esterase from either porcine liver or rabbit liver in vitro and afforded DCA (at a mole ratio of 1:1) and ISOX. However, further studies are needed in order to determine whether UTL-5g is metabolized by microsomal enzymes to produce ISOX and DCA. Copyright © 2013 Elsevier B.V. All rights reserved.
Swartz, Kenneth; Zhang, Yiguan; Valeriote, Frederick; Chen, Ben; Shaw, Jiajiu
2013-01-01
UTL-5g is a novel small-molecule chemoprotector that lowers hepatotoxicity, nephrotoxicity, and myelotoxicity induced by cisplatin through TNF-α inhibition among other factors. As a prelude to investigating the metabolites of UTL-5g, we set out to identify the enzymatic products of UTL-5g under the treatment of both porcine liver esterase (PLE) and rabbit liver esterase (RLE). First, a number of mixtures made by UTL-5g and PLE were incubated at 25 °C. At predetermined time points, individual samples were quenched by acetonitrile, vortexed, and centrifuged. The supernatants were then analyzed by reversed-phase HPLC (using a C18 column). The retention times and UV/Vis spectra of individual peaks were compared to those of UTL-5g and its two postulated enzymatic products; thus the enzymatic products of UTL-5g were tentatively identified. Secondly, a different HPLC method (providing different retentions times) was used to cross-check and to confirm the identities of the two enzymatic products. Based on the observations, it was concluded that under the treatment of PLE, the major enzymatic products of UTL-5g were 5-methyliosxazole-3-carboxylic acid (ISOX) and 2,4-dichloroaniline (DCA). Treatment of UTL-5g by RLE also provided the same enzymatic products of UTL-5g from esterase. These results indicate that the peptide bond in UTL-5g was cleaved by PLE/RLE. Michaelis–Menten kinetics showed that the Km values of UTL-5g were 2.07 mM with PLE and 0.37 mM with RLE indicating that UTL-5g had a higher affinity with RLE. In summary, by a simple HPLC approach, we have concluded that the peptide bond in UTL-5g was cleaved by esterase from either porcine liver or rabbit liver in vitro and afforded DCA (at a mole ratio of 1:1) and ISOX. However, further studies are needed in order to determine whether UTL-5g is metabolized by microsomal enzymes to produce ISOX and DCA. PMID:24126042
A theranostic dental pulp capping agent with improved MRI and CT contrast and biological properties.
Mastrogiacomo, S; Güvener, N; Dou, W; Alghamdi, H S; Camargo, W A; Cremers, J G O; Borm, P J A; Heerschap, A; Oosterwijk, E; Jansen, J A; Walboomers, X F
2017-10-15
Different materials have been used for vital dental pulp treatment. Preferably a pulp capping agent should show appropriate biological performance, excellent handling properties, and a good imaging contrast. These features can be delivered into a single material through the combination of therapeutic and diagnostic agents (i.e. theranostic). Calcium phosphate based composites (CPCs) are potentially ideal candidate for pulp treatment, although poor imaging contrast and poor dentino-inductive properties are limiting their clinical use. In this study, a theranostic dental pulp capping agent was developed. First, imaging properties of the CPC were improved by using a core-shell structured dual contrast agent (csDCA) consisting of superparamagnetic iron oxide (SPIO) and colloidal gold, as MRI and CT contrast agent respectively. Second, biological properties were implemented by using a dentinogenic factor (i.e. bone morphogenetic protein 2, BMP-2). The obtained CPC/csDCA/BMP-2 composite was tested in vivo, as direct pulp capping agent, in a male Habsi goat incisor model. Our outcomes showed no relevant alteration of the handling and mechanical properties (e.g. setting time, injectability, and compressive strength) by the incorporation of csDCA particles. In vivo results proved MRI contrast enhancement up to 7weeks. Incisors treated with BMP-2 showed improved tertiary dentin deposition as well as faster cement degradation as measured by µCT assessment. In conclusion, the presented theranostic agent matches the imaging and regenerative requirements for pulp capping applications. In this study, we combined diagnostic and therapeutic agents in order to developed a theranostic pulp capping agent with enhanced MRI and CT contrast and improved dentin regeneration ability. In our study we cover all the steps from material preparation, mechanical and in vitro characterization, to in vivo study in a goat dental model. To the best of our knowledge, this is the first time that a theranostic pulp capping material have been developed and tested in an in vivo animal model. Our promising results in term of imaging contrast enhancement and of induction of new dentin formation, open a new scenario in the development of innovative dental materials. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Hortos, William S.
1997-04-01
The use of artificial neural networks (NNs) to address the channel assignment problem (CAP) for cellular time-division multiple access and code-division multiple access networks has previously been investigated by this author and many others. The investigations to date have been based on a hexagonal cell structure established by omnidirectional antennas at the base stations. No account was taken of the use of spatial isolation enabled by directional antennas to reduce interference between mobiles. Any reduction in interference translates into increased capacity and consequently alters the performance of the NNs. Previous studies have sought to improve the performance of Hopfield- Tank network algorithms and self-organizing feature map algorithms applied primarily to static channel assignment (SCA) for cellular networks that handle uniformly distributed, stationary traffic in each cell for a single type of service. The resulting algorithms minimize energy functions representing interference constraint and ad hoc conditions that promote convergence to optimal solutions. While the structures of the derived neural network algorithms (NNAs) offer the potential advantages of inherent parallelism and adaptability to changing system conditions, this potential has yet to be fulfilled the CAP for emerging mobile networks. The next-generation communication infrastructures must accommodate dynamic operating conditions. Macrocell topologies are being refined to microcells and picocells that can be dynamically sectored by adaptively controlled, directional antennas and programmable transceivers. These networks must support the time-varying demands for personal communication services (PCS) that simultaneously carry voice, data and video and, thus, require new dynamic channel assignment (DCA) algorithms. This paper examines the impact of dynamic cell sectoring and geometric conditioning on NNAs developed for SCA in omnicell networks with stationary traffic to improve the metrics of convergence rate and call blocking. Genetic algorithms (GAs) are also considered in PCS networks as a means to overcome the known weakness of Hopfield NNAs in determining global minima. The resulting GAs for DCA in PCS networks are compared to improved DCA algorithms based on Hopfield NNs for stationary cellular networks. Algorithm performance is compared on the basis of rate of convergence, blocking probability, analytic complexity, and parametric sensitivity to transient traffic demands and channel interference.
Yamamoto, Yosuke; Terada, Kazuhiko; Ohta, Mitsuyasu; Mikami, Wakako; Yokota, Hajime; Hayashi, Michio; Miyashita, Jun; Azuma, Teruhisa; Fukuma, Shingo; Fukuhara, Shunichi
2017-01-01
Objective Diagnosis of community-acquired pneumonia (CAP) in the elderly is often delayed because of atypical presentation and non-specific symptoms, such as appetite loss, falls and disturbance in consciousness. The aim of this study was to investigate the external validity of existing prediction models and the added value of the non-specific symptoms for the diagnosis of CAP in elderly patients. Design Prospective cohort study. Setting General medicine departments of three teaching hospitals in Japan. Participants A total of 109 elderly patients who consulted for upper respiratory symptoms between 1 October 2014 and 30 September 2016. Main outcome measures The reference standard for CAP was chest radiograph evaluated by two certified radiologists. The existing models were externally validated for diagnostic performance by calibration plot and discrimination. To evaluate the additional value of the non-specific symptoms to the existing prediction models, we developed an extended logistic regression model. Calibration, discrimination, category-free net reclassification improvement (NRI) and decision curve analysis (DCA) were investigated in the extended model. Results Among the existing models, the model by van Vugt demonstrated the best performance, with an area under the curve of 0.75(95% CI 0.63 to 0.88); calibration plot showed good fit despite a significant Hosmer-Lemeshow test (p=0.017). Among the non-specific symptoms, appetite loss had positive likelihood ratio of 3.2 (2.0–5.3), negative likelihood ratio of 0.4 (0.2–0.7) and OR of 7.7 (3.0–19.7). Addition of appetite loss to the model by van Vugt led to improved calibration at p=0.48, NRI of 0.53 (p=0.019) and higher net benefit by DCA. Conclusions Information on appetite loss improved the performance of an existing model for the diagnosis of CAP in the elderly. PMID:29122806
Binding of bile acids by pastry products containing bioactive substances during in vitro digestion.
Dziedzic, Krzysztof; Górecka, Danuta; Szwengiel, Artur; Smoczyńska, Paulina; Czaczyk, Katarzyna; Komolka, Patrycja
2015-03-01
The modern day consumer tends to choose products with health enhancing properties, enriched in bioactive substances. One such bioactive food component is dietary fibre, which shows a number of physiological properties including the binding of bile acids. Dietary fibre should be contained in everyday, easily accessible food products. Therefore, the aim of this study was to determine sorption capacities of primary bile acid (cholic acid - CA) and secondary bile acids (deoxycholic - DCA and lithocholic acids - LCA) by muffins (BM) and cookies (BC) with bioactive substances and control muffins (CM) and cookies (CC) in two sections of the in vitro gastrointestinal tract. Variations in gut flora were also analysed in the process of in vitro digestion of pastry products in a bioreactor. Enzymes: pepsin, pancreatin and bile salts: cholic acid, deoxycholic acid and lithocholic acid were added to the culture. Faecal bacteria, isolated from human large intestine, were added in the section of large intestine. The influence of dietary fibre content in cookies and concentration of bile acids in two stages of digestion were analysed. Generally, pastry goods with bioactive substances were characterized by a higher content of total fibre compared with the control samples. These products also differ in the profile of dietary fibre fractions. Principal Component Analysis (PCA) showed that the bile acid profile after two stages of digestion depends on the quality and quantity of fibre. The bile acid profile after digestion of BM and BC forms one cluster, and with the CM and CC forms a separate cluster. High concentration of H (hemicellulose) is positively correlated with LCA (low binding effect) and negatively correlated with CA and DCA contents. The relative content of bile acids in the second stage of digestion was in some cases above the content in the control sample, particularly LCA. This means that the bacteria introduced in the 2nd stage of digestion synthesize the LCA.
Rajeshkumar, N V; Yabuuchi, Shinichi; Pai, Shweta G; De Oliveira, Elizabeth; Kamphorst, Jurre J; Rabinowitz, Joshua D; Tejero, Héctor; Al-Shahrour, Fátima; Hidalgo, Manuel; Maitra, Anirban; Dang, Chi V
2017-09-15
Purpose: To identify effective metabolic inhibitors to suppress the aggressive growth of pancreatic ductal adenocarcinoma (PDAC), we explored the in vivo antitumor efficacy of metabolic inhibitors, as single agents, in a panel of patient-derived PDAC xenograft models (PDX) and investigated whether genomic alterations of tumors correlate with the sensitivity to metabolic inhibitors. Experimental Design: Mice with established PDAC tumors from 6 to 13 individual PDXs were randomized and treated, once daily for 4 weeks, with either sterile PBS (vehicle) or the glutaminase inhibitor bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide (BPTES), transaminase inhibitor aminooxyacetate (AOA), pyruvate dehydrogenase kinase inhibitor dichloroacetate (DCA), autophagy inhibitor chloroquine (CQ), and mitochondrial complex I inhibitor phenformin/metformin. Results: Among the agents tested, phenformin showed significant tumor growth inhibition (>30% compared with vehicle) in 5 of 12 individual PDXs. Metformin, at a fivefold higher dose, displayed significant tumor growth inhibition in 3 of 12 PDXs similar to BPTES (2/8 PDXs) and DCA (2/6 PDXs). AOA and CQ had the lowest response rates. Gene set enrichment analysis conducted using the baseline gene expression profile of pancreatic tumors identified a gene expression signature that inversely correlated with phenformin sensitivity, which is in agreement with the phenformin gene expression signature of NIH Library of Integrated Network-based Cellular Signatures (LINCS). The PDXs that were more sensitive to phenformin showed a baseline reduction in amino acids and elevation in oxidized glutathione. There was no correlation between phenformin response and genetic alterations in KRAS, TP53, SMAD4 , or PTEN Conclusions: Phenformin treatment showed relatively higher antitumor efficacy against established PDAC tumors, compared with the efficacy of other metabolic inhibitors and metformin. Phenformin treatment significantly diminished PDAC tumor progression and prolonged tumor doubling time. Overall, our results serve as a foundation for further evaluation of phenformin as a therapeutic agent in pancreatic cancer. Clin Cancer Res; 23(18); 5639-47. ©2017 AACR . ©2017 American Association for Cancer Research.
Strategic Performance Management Evaluation for the Navy’s Splice Local Area Networks.
1985-04-01
Communications Agency (DCA)/Federal Data Corporation (FDC) literature; an extensive survey of academic and professional book and article literature... interesting closing note on strategic planning characteristics is that the period during which collapse or disaster develops is of the same order as the...accepted set of standards. In computer performance, such things as paging rates , throughput, input/output channel usage, turnaround * 32 EM-. time
Submission of Telecommunications Service Requests
1990-01-01
Forces , October 1974. j. DoD 5220.22-R, Industrial Security Regulation, February 1984. k. DCA OPLAN 1-84, Worldwide AUTODIN Restoral Plan, October...following: (1) Mobile and/or transportable co. facilities and assets organic to Army, Navy, Air Force , and Fleet I. ;, unless specifically desiqnated as...agency and, for the Department of Defense, the Under Secretary and any Assistant Secretary of the Departments of the Army, Navy. and Air Force and
1976-11-01
protec- tion and will require additional measures, such as the application of conductive filter-loaded plastic resins to each joint connection...Lawrence Liver- more Laboratory, Livermore CA, 1974 31. Whitson, A. L., "DCA HEMP Hardness Certification Methodology Status", Stanford Research...of Chief of Engineers, Depot of the Army, December 1971 34. "Development of HEMP Assessment Methodology for Satellite Terminals", Intelcom Rad Tech
The Evolution of the Center on Education Policy: From an Idea to a Major Influence
ERIC Educational Resources Information Center
Lewis, Anne
2012-01-01
During hearings in the late 1980s on education legislation, the frustrated chairman of the Education and Labor Committee of the U.S. House of Representatives, Rep. Gus Hawkins (D-CA), would sometimes lean over to his chief counsel and ask: "Why can't these people agree on the facts? If they did that, we could solve these problems quickly." That…
Signaling the End of Deterrence Afforded by Dual Capable Aircraft
2017-04-06
INTRODUCTION For more than 60 years, the Unites States and Europe relied on fighter aircraft capable of executing conventional and nuclear strike...missions. Known as dual-capable aircraft (DCA), these fighters were an integral part of the US extended nuclear deterrence strategy in Asia and Europe...force structure, sustainment and modernization by the US and Allied nations allowed tactical nuclear forces to atrophy. Starting in 2010, the US and
Ahadian, Samad; Mizuseki, Hiroshi; Kawazoe, Yoshiyuki
2010-12-15
A molecular dynamics (MD) approach was employed to simulate the imbibition of a designed nanopore by a simple fluid (i.e., a Lennard-Jones (LJ) fluid). The length of imbibition as a function of time for various interactions between the LJ fluid and the pore wall was recorded for this system (i.e., the LJ fluid and the nanopore). By and large, the kinetics of imbibition was successfully described by the Lucas-Washburn (LW) equation, although deviation from it was observed in some cases. This lack of agreement is due to the neglect of the dynamic contact angle (DCA) in the LW equation. Two commonly used models (i.e., hydrodynamic and molecular-kinetic (MK) models) were thus employed to calculate the DCA. It is demonstrated that the MK model is able to justify the simulation results in which are not in good agreement with the simple LW equation. However, the hydrodynamic model is not capable of doing that. Further investigation of the MD simulation data revealed an interesting fact that there is a direct relationship between the wall-fluid interaction and the speed of the capillary imbibition. More evidence to support this claim is presented. Copyright © 2010 Elsevier Inc. All rights reserved.
A Boundary Scan Test Vehicle for Direct Chip Attach Testing
NASA Technical Reports Server (NTRS)
Parsons, Heather A.; DAgostino, Saverio; Arakaki, Genji
2000-01-01
To facilitate the new faster, better and cheaper spacecraft designs, smaller more mass efficient avionics and instruments are using higher density electronic packaging technologies such as direct chip attach (DCA). For space flight applications, these technologies need to have demonstrated reliability and reasonably well defined fabrication and assembly processes before they will be accepted as baseline designs in new missions. As electronics shrink in size, not only can repair be more difficult, but 49 probing" circuitry can be very risky and it becomes increasingly more difficult to identify the specific source of a problem. To test and monitor these new technologies, the Direct Chip Attach Task, under NASA's Electronic Parts and Packaging Program (NEPP), chose the test methodology of boundary scan testing. The boundary scan methodology was developed for interconnect integrity and functional testing at hard to access electrical nodes. With boundary scan testing, active devices are used and failures can be identified to the specific device and lead. This technology permits the incorporation of "built in test" into almost any circuit and thus gives detailed test access to the highly integrated electronic assemblies. This presentation will describe boundary scan, discuss the development of the boundary scan test vehicle for DCA and current plans for testing of direct chip attach configurations.
Localization of phonons in mass-disordered alloys: A typical medium dynamical cluster approach
Jarrell, Mark; Moreno, Juana; Raja Mondal, Wasim; ...
2017-07-20
The effect of disorder on lattice vibrational modes has been a topic of interest for several decades. In this article, we employ a Green's function based approach, namely, the dynamical cluster approximation (DCA), to investigate phonons in mass-disordered systems. Detailed benchmarks with previous exact calculations are used to validate the method in a wide parameter space. An extension of the method, namely, the typical medium DCA (TMDCA), is used to study Anderson localization of phonons in three dimensions. We show that, for binary isotopic disorder, lighter impurities induce localized modes beyond the bandwidth of the host system, while heavier impuritiesmore » lead to a partial localization of the low-frequency acoustic modes. For a uniform (box) distribution of masses, the physical spectrum is shown to develop long tails comprising mostly localized modes. The mobility edge separating extended and localized modes, obtained through the TMDCA, agrees well with results from the transfer matrix method. A reentrance behavior of the mobility edge with increasing disorder is found that is similar to, but somewhat more pronounced than, the behavior in disordered electronic systems. Our work establishes a computational approach, which recovers the thermodynamic limit, is versatile and computationally inexpensive, to investigate lattice vibrations in disordered lattice systems.« less
NASA Technical Reports Server (NTRS)
1974-01-01
The effect of aircraft operational techniques in the terminal area on community noise impact of future short-haul aircraft was investigated. These operational techniques affected altitude, flap retraction rate, thrust cutback altitude, amount of thrust cutback, and amount of turning. During landing the parameters varied were glide slope angle, change in slope angle (two segment approach), and flap extension rate. One mechanical-flap (MF) aircraft and one externally-blown-flap (EBF) aircraft were used to study by noise impact at four U.S. airports, Hanscom Field (Boston); Washington National; Midway (Chicago); and Orange County (California). With the exception of Washington National (DCA), the study showed that a reduction of approximately 40 percent in the number of people highly annoyed (as defined in the study) can be obtained by using these operational techniques. At DCA the number of people highly annoyed using the standard procedure was quite low, but it is significant that the minimumimpact case for Runway 36 reduced the number of people highly annoyed to zero using a power cutback and a turning departure path. The evaluation procedures and methodology developed in this study represents an advance in acoustical state-of-the-art and should provide an effective and useful tool for determining aircraft noise impact upon the airport community.
Queen volatiles as a modulator of Tetragonisca angustula drone behavior.
Fierro, Macario M; Cruz-López, Leopoldo; Sánchez, Daniel; Villanueva-Gutiérrez, Rogel; Vandame, Remy
2011-11-01
Tetragonisca angustula mating occurs during the virgin queen nuptial flight, usually in the presence of a drone congregation area (DCA). The presence of virgin queen pheromone is considered the trigger for DCA establishment, although this has not been demonstrated experimentally. We established meliponaries, in different habitats, with T. angustula virgin queens during the main drone reproduction period. Eight DCAs were observed in urban areas, and all established outside or near colonies containing at least one virgin queen. The accumulation of drones in the DCAs occurred from 08:00 to 18:00 h and over 3-35 days. The number of drones in DCAs ranged from 60 to 2,000. In field trials, drones were attracted to virgin queens and also, unexpectedly, to physogastric queens. Volatiles collected from both virgin and physogastric queens elicited strong electoantennogram (EAG) responses from drones. Virgin and physogastric queen volatiles were qualitatively similar, but quantitatively different, in chemical composition. The queen's abdomen was the principal source of these compounds. Isopropyl hexanoate (IPH), the most abundant compound in virgin queen volatiles and one of the most abundant in physogastric queen volatiles, was identified as one of the compounds that elicited EAG responses and was demonstrated to attract drones in a field test.
Localization of phonons in mass-disordered alloys: A typical medium dynamical cluster approach
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jarrell, Mark; Moreno, Juana; Raja Mondal, Wasim
The effect of disorder on lattice vibrational modes has been a topic of interest for several decades. In this article, we employ a Green's function based approach, namely, the dynamical cluster approximation (DCA), to investigate phonons in mass-disordered systems. Detailed benchmarks with previous exact calculations are used to validate the method in a wide parameter space. An extension of the method, namely, the typical medium DCA (TMDCA), is used to study Anderson localization of phonons in three dimensions. We show that, for binary isotopic disorder, lighter impurities induce localized modes beyond the bandwidth of the host system, while heavier impuritiesmore » lead to a partial localization of the low-frequency acoustic modes. For a uniform (box) distribution of masses, the physical spectrum is shown to develop long tails comprising mostly localized modes. The mobility edge separating extended and localized modes, obtained through the TMDCA, agrees well with results from the transfer matrix method. A reentrance behavior of the mobility edge with increasing disorder is found that is similar to, but somewhat more pronounced than, the behavior in disordered electronic systems. Our work establishes a computational approach, which recovers the thermodynamic limit, is versatile and computationally inexpensive, to investigate lattice vibrations in disordered lattice systems.« less
Shen, Xianjun; Yi, Li; Jiang, Xingpeng; He, Tingting; Yang, Jincai; Xie, Wei; Hu, Po; Hu, Xiaohua
2017-01-01
How to identify protein complex is an important and challenging task in proteomics. It would make great contribution to our knowledge of molecular mechanism in cell life activities. However, the inherent organization and dynamic characteristic of cell system have rarely been incorporated into the existing algorithms for detecting protein complexes because of the limitation of protein-protein interaction (PPI) data produced by high throughput techniques. The availability of time course gene expression profile enables us to uncover the dynamics of molecular networks and improve the detection of protein complexes. In order to achieve this goal, this paper proposes a novel algorithm DCA (Dynamic Core-Attachment). It detects protein-complex core comprising of continually expressed and highly connected proteins in dynamic PPI network, and then the protein complex is formed by including the attachments with high adhesion into the core. The integration of core-attachment feature into the dynamic PPI network is responsible for the superiority of our algorithm. DCA has been applied on two different yeast dynamic PPI networks and the experimental results show that it performs significantly better than the state-of-the-art techniques in terms of prediction accuracy, hF-measure and statistical significance in biology. In addition, the identified complexes with strong biological significance provide potential candidate complexes for biologists to validate.
Laboratory test for ice adhesion strength using commercial instrumentation.
Wang, Chenyu; Zhang, Wei; Siva, Adarsh; Tiea, Daniel; Wynne, Kenneth J
2014-01-21
A laboratory test method for evaluating ice adhesion has been developed employing a commercially available instrument normally used for dynamic mechanical analysis (TA RSA-III). This is the first laboratory ice adhesion test that does not require a custom-built apparatus. The upper grip range of ∼10 mm is an enabling feature that is essential for the test. The method involves removal of an ice cylinder from a polymer coating with a probe and the determination of peak removal force (Ps). To validate the test method, the strength of ice adhesion was determined for a prototypical glassy polymer, poly(methyl methacrylate). The distance of the probe from the PMMA surface has been identified as a critical variable for Ps. The new test provides a readily available platform for investigating fundamental surface characteristics affecting ice adhesion. In addition to the ice release test, PMMA coatings were characterized using DSC, DCA, and TM-AFM.
Kinetic Studies of Reactions in Solution Using Fast Mass Spectrometry
2013-08-13
dicyanamide ionic liquids Hypergolic fuels, or hypergols, can be ignited by exposure to an oxidizing agent under ambient conditions and are a common...DCA) based ionic liquids are a less volatile alternative that are less viscous than most ionic liquids ; however, ignition of these compounds...Condensates upon Hypergolic Ignition of Dicyanamide Ionic Liquids ," Angew. Chem. Int. Ed. 50, 8634–8637 (2011). (7) R. H. Perry, D. I. Bellovin, E
Internet Protocol Implementation Guide.
1982-08-01
RD-R153 624 INTERNET PROTOCOL IMPLEMENTATION GIDE(U) SRI 1/2 INTERNATIONAL MENLO PARK CA NETWORK INFORMATION CENTER AUG 82 DCA2e-83-C-8e25 N... INTERNET PROTOCOL S IMPLEMENTATION GUIDE August 1982 DTICFL. !.ECTE .-" MAY 1 31985 ;z B Q.. Network Information Center SRI International Menlo Park...this is more information than the receiving Internet * module needs. The specified procedure is to take the return route recorded in the first
Evaluation of DCS III Transmission Alternatives, Phase II, Task 1.
1981-08-31
Agency Defense Communications Engineering Center Reston, Virginia 22090 Contract No. DCA 100-79-C--0044 ,D ii 2 01982 ONG SPACI IAE K ROONOO IIACH...Transmission Media Alternatives Task 2. Development of Evolving DCS Transmission System Al ternatives Task 3. Identification of Technology and Regulatory...For existing tree growth, add 15 m. For smaller vegetation, add 3 m. 11. Determine the antenna tower heights to insure line-of-sight clearance above the
Piao, Lin; Fang, Yong-Hu; Kubler, Manfred M; Donnino, Michael W; Sharp, Willard W
2017-01-01
Post-ischemic changes in cellular metabolism alter myocardial and neurological function. Pyruvate dehydrogenase (PDH), the limiting step in mitochondrial glucose oxidation, is inhibited by increased expression of PDH kinase (PDK) during ischemia/reperfusion injury. This results in decreased utilization of glucose to generate cellular ATP. Post-cardiac arrest (CA) hypothermia improves outcomes and alters metabolism, but its influence on PDH and PDK activity following CA are unknown. We hypothesized that therapeutic hypothermia (TH) following CA is associated with the inhibition of PDK activity and increased PDH activity. We further hypothesized that an inhibitor of PDK activity, dichloroacetate (DCA), would improve PDH activity and post-CA outcomes. Anesthetized and ventilated adult female C57BL/6 wild-type mice underwent a 12-minute KCl-induced CA followed by cardiopulmonary resuscitation. Compared to normothermic (37°C) CA controls, administering TH (30°C) improved overall survival (72-hour survival rate: 62.5% vs. 28.6%, P<0.001), post-resuscitation myocardial function (ejection fraction: 50.9±3.1% vs. 27.2±2.0%, P<0.001; aorta systolic pressure: 132.7±7.3 vs. 72.3±3.0 mmHg, P<0.001), and neurological scores at 72-hour post CA (9.5±1.3 vs. 5.4±1.3, P<0.05). In both heart and brain, CA increased lactate concentrations (1.9-fold and 3.1-fold increase, respectively, P<0.01), decreased PDH enzyme activity (24% and 50% reduction, respectively, P<0.01), and increased PDK protein expressions (1.2-fold and 1.9-fold, respectively, P<0.01). In contrast, post-CA treatment with TH normalized lactate concentrations (P<0.01 and P<0.05) and PDK expressions (P<0.001 and P<0.05), while increasing PDH activity (P<0.01 and P<0.01) in both the heart and brain. Additionally, treatment with DCA (0.2 mg/g body weight) 30 min prior to CA improved both myocardial hemodynamics 2 hours post-CA (aortic systolic pressure: 123±3 vs. 96±4 mmHg, P<0.001) and 72-hour survival rates (50% vs. 19%, P<0.05) in normothermic animals. Enhanced PDH activity in the setting of TH or DCA administration is associated with improved post-CA resuscitation outcomes. PDH is a promising therapeutic target for improving post-CA outcomes.
Wu, Jianmei; Shaw, Jiajiu; Dubaisi, Sarah; Valeriote, Frederick; Li, Jing
2014-12-01
N-(2,4-dichlorophenyl)-5-methyl-1,2-oxazole-3-carboxamide (UTL-5g), a potential chemo- and radioprotective agent, acts as a prodrug requiring bioactivation to the active metabolite 5-methylisoxazole-3-carboxylic acid (ISOX). UTL-5g hydrolysis to ISOX and 2,4-dichloroaniline (DCA) has been identified in porcine and rabbit liver esterases. The purpose of this study was to provide insights on the metabolism and drug interaction potential of UTL-5g in humans. The kinetics of UTL-5g hydrolysis was determined in human liver microsomes (HLM) and recombinant human carboxylesterases (hCE1b and hCE2). The potential of UTL-5g and its metabolites for competitive inhibition and time-dependent inhibition of microsomal cytochrome P450 (P450) was examined in HLM. UTL-5g hydrolysis to ISOX and DCA in HLM were NADPH-independent, with a maximum rate of reaction (Vmax) of 11.1 nmol/min per mg and substrate affinity (Km) of 41.6 µM. Both hCE1b and hCE2 effectively catalyzed UTL-5g hydrolysis, but hCE2 exhibited ∼30-fold higher catalytic efficiency (Vmax/Km) than hCE1b. UTL-5g and DCA competitively inhibited microsomal CYP1A2, CYP2B6, and CYP2C19 (IC50 values <50 µM), and exhibited time-dependent inhibition of microsomal CYP1A2 with the inactivation efficiency (kinact/KI) of 0.68 and 0.51 minute(-1)·mM(-1), respectively. ISOX did not inhibit or inactivate any tested microsomal P450. In conclusion, hCE1b and hCE2 play a key role in the bioactivation of UTL-5g. Factors influencing carboxylesterase activities may have a significant impact on the pharmacological and therapeutic effects of UTL-5g. UTL-5g has the potential to inhibit P450-mediated metabolism through competitive inhibition or time-dependent inhibition. Caution is particularly needed for potential drug interactions involving competitive inhibition or time-dependent inhibition of CYP1A2 in the future clinical development of UTL-5g. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.
Wu, Jianmei; Shaw, Jiajiu; Dubaisi, Sarah; Valeriote, Frederick
2014-01-01
N-(2,4-dichlorophenyl)-5-methyl-1,2-oxazole-3-carboxamide (UTL-5g), a potential chemo- and radioprotective agent, acts as a prodrug requiring bioactivation to the active metabolite 5-methylisoxazole-3-carboxylic acid (ISOX). UTL-5g hydrolysis to ISOX and 2,4-dichloroaniline (DCA) has been identified in porcine and rabbit liver esterases. The purpose of this study was to provide insights on the metabolism and drug interaction potential of UTL-5g in humans. The kinetics of UTL-5g hydrolysis was determined in human liver microsomes (HLM) and recombinant human carboxylesterases (hCE1b and hCE2). The potential of UTL-5g and its metabolites for competitive inhibition and time-dependent inhibition of microsomal cytochrome P450 (P450) was examined in HLM. UTL-5g hydrolysis to ISOX and DCA in HLM were NADPH-independent, with a maximum rate of reaction (Vmax) of 11.1 nmol/min per mg and substrate affinity (Km) of 41.6 µM. Both hCE1b and hCE2 effectively catalyzed UTL-5g hydrolysis, but hCE2 exhibited ∼30-fold higher catalytic efficiency (Vmax/Km) than hCE1b. UTL-5g and DCA competitively inhibited microsomal CYP1A2, CYP2B6, and CYP2C19 (IC50 values <50 µM), and exhibited time-dependent inhibition of microsomal CYP1A2 with the inactivation efficiency (kinact/KI) of 0.68 and 0.51 minute−1·mM−1, respectively. ISOX did not inhibit or inactivate any tested microsomal P450. In conclusion, hCE1b and hCE2 play a key role in the bioactivation of UTL-5g. Factors influencing carboxylesterase activities may have a significant impact on the pharmacological and therapeutic effects of UTL-5g. UTL-5g has the potential to inhibit P450-mediated metabolism through competitive inhibition or time-dependent inhibition. Caution is particularly needed for potential drug interactions involving competitive inhibition or time-dependent inhibition of CYP1A2 in the future clinical development of UTL-5g. PMID:25249693
Defense RDT and E Planning and Strategy Parameters: Methodological Considerations
1974-12-01
Lions ant, i :,lation, oil embargo, and other mineral scarcities. These factors .o w .vy -.ponr Lne program decisions made during the defense planning...PAGE (When Data Entered) REPOT DCUMNTATON AGEREAD INSTRUCTIONSREPOT DCUMNTATON AGEBEFORC COMPLETING FORM (j . OVT ACCESSION NO.,44- I PIE 4CAIL1...Wilson Boulevard 14 MO NITORING AGENCY NAME & ADDRESS (if diff, from Con~trolling office) I Defense Supply Service-Washington 2’,DCA~FCTOI--uw.A*4c-Room
Defense switched network technology and experiments program
NASA Astrophysics Data System (ADS)
Weinstein, C. J.
1983-09-01
This report documents work performed during FY 1983 on the DCA-sponsored Defense Switched Network Technology and Experiments Program. The areas of work reported are: (1) development of routing algorithms for application in the Defense Switched Network (DSN); (2) instrumentation and integration of the Experimental Integrated Switched Network (EISN) test facility; (3) development and test of data communication techniques using DoD-standard data protocols in an integrated voice/data network; and (4) EISN system coordination and experiment planning.
1993-09-01
who under the terms of the Archeological and Historic Preservation Act must respond within 48 hours of notification. The DCA may render an immediate...1965 The Surviving Chumash. UCLA Archaeological Survey Annual Reports 65:277-302. Grant, Campbell 1973a Chuirash: Introduction. In R.F. Heizer , ed...Coastal Chumash. In R.F. Heizer , et., California. Volume 8, Handbook of North American"Indians, William C. Sturtevant, General Editor. Washington
Mating flights select for symmetry in honeybee drones ( Apis mellifera)
NASA Astrophysics Data System (ADS)
Jaffé, Rodolfo; Moritz, Robin F. A.
2010-03-01
Males of the honeybee ( Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability and a higher responsiveness to the queen’s visual and chemical cues. Here, we tested this idea relying on wing fluctuating asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate the action of selection during drone mating flights for the first time, showing that developmental stability can influence the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer some fitness advantages to the queens.
Mating flights select for symmetry in honeybee drones (Apis mellifera).
Jaffé, Rodolfo; Moritz, Robin F A
2010-03-01
Males of the honeybee (Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability and a higher responsiveness to the queen's visual and chemical cues. Here, we tested this idea relying on wing fluctuating asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate the action of selection during drone mating flights for the first time, showing that developmental stability can influence the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer some fitness advantages to the queens.
Hostile pelvis: how to avoid permanent stoma.
Barugola, Giuliano; Bertocchi, Elisa; Gentile, Irene; Cracco, Nicola; Sartori, Carlo Augusto; Ruffo, Giacomo
2018-06-27
The aim was to report our experience with delayed colo-anal anastomosis (DCA) to avoid permanent stoma for complex rectal cases evaluating short- and long-term outcomes. Nine patients who underwent DCA from 2011 to 2016 were collected and analysed case by case. We considered medical history and surgical outcomes. Long-term bowel function was evaluated using the Wexner and low anterior resection syndrome (LARS) score at 6, 12 and 24 months. The range from previous surgery and salvage procedure was 337 days. All cases were performed with a full laparoscopic approach. The median length of hospital stay was 15 days. The median follow-up was 970.5 days. There was no peri-operative mortality. Two patients developed a post-operative pelvic abscess that required redo surgery. Long-term post-operative complications were mucosal prolapsed, anastomosis retraction and anastomotic stricture. The average values of LARS and Wexner scores were, respectively, at 6 months 33.7 and 16.2, at 12 months 28.5 and 11.7, at 24 months 21.1 and 6.7. Colo-anal sleeve delayed anastomosis appears a real answer to avoid permanent stoma in selected patients. The laparoscopic procedure is safe and feasible for skilful mini-invasive surgeons. Our experience describes the complexity of clinical history of these patients underlying a slow, but progressive improvement in continence after restoration of bowel continuity.
Interlaced coarse-graining for the dynamical cluster approximation
NASA Astrophysics Data System (ADS)
Haehner, Urs; Staar, Peter; Jiang, Mi; Maier, Thomas; Schulthess, Thomas
The negative sign problem remains a challenging limiting factor in quantum Monte Carlo simulations of strongly correlated fermionic many-body systems. The dynamical cluster approximation (DCA) makes this problem less severe by coarse-graining the momentum space to map the bulk lattice to a cluster embedded in a dynamical mean-field host. Here, we introduce a new form of an interlaced coarse-graining and compare it with the traditional coarse-graining. We show that it leads to more controlled results with weaker cluster shape and smoother cluster size dependence, which with increasing cluster size converge to the results obtained using the standard coarse-graining. In addition, the new coarse-graining reduces the severity of the fermionic sign problem. Therefore, it enables calculations on much larger clusters and can allow the evaluation of the exact infinite cluster size result via finite size scaling. To demonstrate this, we study the hole-doped two-dimensional Hubbard model and show that the interlaced coarse-graining in combination with the DCA+ algorithm permits the determination of the superconducting Tc on cluster sizes, for which the results can be fitted with the Kosterlitz-Thouless scaling law. This research used resources of the Oak Ridge Leadership Computing Facility (OLCF) awarded by the INCITE program, and of the Swiss National Supercomputing Center. OLCF is a DOE Office of Science User Facility supported under Contract DE-AC05-00OR22725.
Zhang, Kejia; Zhou, Xinyan; Zhang, Tuqiao; Mao, Minmin; Li, Lei; Liao, Wenchao
2016-11-01
Chloroanisoles are often reported as off-flavor compounds which produce an earthy and musty flavors and odors in drinking water. To improve understanding and ultimately minimize the formation of 2,4-dichloroanisole (2,4-DCA), 2,6-dichloroanisole (2,6-DCA) and 2,4,6-trichloroanisole (2,4,6-TCA), which have low odor threshold concentrations (OTC: 0.03-4 ng L(-1)), a kinetic database for the chlorination of anisole was established by kinetic measurements. The results showed that HOCl reacted with anisole in acidic solution, with the hydrogen ion as an important catalyst. Quantification of product distribution of the produced chloroanisoles demonstrated that a chlorine attack in the para-position was favored over the ortho-position. A kinetic model was formulated, which permitted investigation of the relative importance of the chlorine dose and other water quality parameters including the concentrations of anisole and several metal ions, as well as temperature, on the product distribution of chloroanisoles. In general, high chlorine doses led to low concentrations of intermediates. The presence of ions such as Fe(3+) and Al(3+) facilitated the formation of chloroanisoles, but Zn(2+) and Mn(2+) did not. The kinetic model can be applied to optimize water chlorination and minimize earthy and musty odors. Copyright © 2016 Elsevier Ltd. All rights reserved.
Macroinvertebrate palaeo-communities from the Jurassic succession of Gebel Maghara (Sinai, Egypt)
NASA Astrophysics Data System (ADS)
Abdelhady, Ahmed Awad; Fürsich, Franz Theodor
2014-09-01
Macrobenthic palaeo-communities of the Middle and Upper Jurassic strata of G. Maghara, Egypt, were investigated to identify relationships with environmental parameters and to trace the temporal changes of the ecosystem associated with sea-level fluctuations. The quantitative analysis of a data matrix comprising 198 macrobenthic taxa in 138 samples collected from four sections identified nine associations and three assemblages, interpreted to be representative of their original environment. Non-Metric Multidimensional Scaling (NMDS) delineated the same degree of habitat partitioning as hierarchical clusters with very little overlap. Detrended Correspondence Analysis (DCA) identified water depth as the primary environmental gradient controlling the distribution of the fauna, while Axis 2 reflects substrate consistency. Community structure is related to the various ramp environments. Based on diversities, the associations and assemblages have been divided into two major groups, low-stress polyspecific associations and high-stress paucispecific associations. The low-stress polyspecific associations were interpreted to represent two different habitats, a high-energy, firm substrate habitat, in which epifaunal bivalves and brachiopods in addition to solitary corals dominated during advanced stages of transgression, and a low-energy, soft substrate habitat dominated by infaunal bivalves during the maximum flooding. The high-stress paucispecific associations are dominated by one or few taxa and occurred (1) in an oligotrophic setting that developed during episodes of sediment starvation in restricted inner ramp environments or during early transgression, (2) in a setting characterized by high sedimentation rates which developed during advanced regression, (3) in a distal prodelta setting with soft substrate and dysoxia during sea-level lowstand, and (4) in a high-energy shoal environment during peak regression. A combined stress involving a shortage in food supply, episodic dysoxia, in addition to a soupy substrate may have developed during maximum flooding episodes. Hydrodynamic conditions were most likely the main factor controlling the benthic communities. Hydrodynamic conditions influenced the substrate type, redistributed nutrients and were responsible for stratified water masses and hypoxia. Animal-sediment relationships in addition to replacement between bivalves and brachiopods are also discussed. Middle ramp settings were found to provide the best conditions for macrobenthos.
DOE Office of Scientific and Technical Information (OSTI.GOV)
He, Zhili; Xu, Meiying; Deng, Ye
2010-05-17
The global atmospheric concentration of CO2 has increased by more than 30percent since the industrial revolution. Although the stimulating effects of elevated CO2 (eCO2) on plant growth and primary productivity have been well studied, its influences on belowground microbial communities are poorly understood and controversial. In this study, we showed a significant change in the structure and functional potential of soil microbial communities at eCO2 in a grassland ecosystem, the BioCON (Biodiversity, CO2 and Nitrogen) experimental site (http://www.biocon.umn.edu/) using a comprehensive functional gene array, GeoChip 3.0, which contains about 28,0000 probes and covers approximately 57,000 gene variants from 292 functionalmore » gene families involved in carbon, nitrogen, phosphorus and sulfur cycles as well as other functional processes. GeoChip data indicated that the functional structure of microbial communities was markedly different between ambient CO2 (aCO2) and eCO2 by detrended correspondence analysis (DCA) of all 5001 detected functional gene probes although no significant differences were detected in the overall microbial diversity. A further analysis of 1503 detected functional genes involved in C, N, P, and S cycles showed that a considerable portion (39percent) of them were only detected under either aCO2 (14percent) or eCO2 (25percent), indicating that the functional characteristics of the microbial community were significantly altered by eCO2. Also, for those shared genes (61percent) detected, some significantly (p<0.05) changed their abundance at eCO2. Especially, genes involved in labile C degradation, such as amyA, egl, and ara for starch, cellulose, and hemicelluloses, respectively, C fixation (e.g., rbcL, pcc/acc), N fixation (nifH), and phosphorus utilization (ppx) were significantly increased under eCO2, while those involved in decomposing recalcitrant C, such as glx, lip, and mnp for lignin degradation remained unchanged. This study provides insights into our understanding of belowground microbial communities and their feedbacks to terrestrial ecosystems at eCO2.« less
Mackin, Dennis; Polf, Jerimy; Peterson, Steve; Beddar, Sam
2013-01-01
Purpose: The authors investigated how the characteristics of the detectors used in a three-stage Compton camera (CC) affect the CC's ability to accurately measure the emission distribution and energy spectrum of prompt gammas (PG) emitted by nuclear de-excitations during proton therapy. The detector characteristics they studied included the material (high-purity germanium [HPGe] and cadmium zinc telluride [CZT]), Doppler broadening (DB), and resolution (lateral, depth, and energy). Methods: The authors simulated three-stage HPGe and CZT CCs of various configurations, detecting gammas from point sources with energies ranging from 0.511 to 7.12 MeV. They also simulated a proton pencil beam irradiating a tissue target to study how the detector characteristics affect the PG data measured by CCs in a clinical proton therapy setting. They used three figures of merit: the distance of closest approach (DCA) and the point of closest approach (PCA) between the measured and actual position of the PG emission origin, and the calculated energy resolution. Results: For CCs with HPGe detectors, DB caused the DCA to be greater than 3 mm for 14% of the 6.13 MeV gammas and 20% of the 0.511 MeV gammas. For CCs with CZT detectors, DB caused the DCA to be greater than 3 mm for 18% of the 6.13 MeV gammas and 25% of the 0.511 MeV gammas. The full width at half maximum (FWHM) of the PCA in the \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}\\hat z\\end{equation*} \\end{document}z^ direction for HPGe and CZT detectors ranged from 1.3 to 0.4 mm for gammas with incident energy ranging from 0.511 to 7.12 MeV. For CCs composed of HPGe detectors, the resolution of incident gamma energy calculated by the CC ranged from 6% to 1% for gammas with true incident energies from 0.511 to 7.12 MeV. For CCs composed of CZT detectors, the resolution of gamma energy calculated by the CC ranged from 10% to 1% for gammas with true incident energies from 0.511 to 7.12 MeV. For HPGe and CZT CCs in which all detector effect were included, the DCA was less than 3 mm for 75% and 68% of the detected gammas, respectively, and restricting gammas to those having energy greater than 2.0 MeV increased these percentages to 83% and 77% for HPGe and CZT, respectively. Distributions of the true gamma origins and the PCA after detector characteristics had been included showed good agreement on beam range and some loss of resolution for the lateral profile of the PG emission. Characteristic energy lines were evident in the calculated gamma energy spectrum. Conclusions: The authors found the following: (1) DB is the dominant source of spatial and energy resolution loss in the CCs at all energy levels; (2) the largest difference in the spatial resolution of HPGe and CZT CCs is that the spatial resolution distributions of CZT have broader tails. The differences in the FWHM of these distributions are small; (3) the energy resolution of both HPGe and CZT three-stage CCs is adequate for PG spectroscopy; and (4) restricting the gammas to those having energy greater than 2.0 MeV can improve the achievable image resolution. PMID:23298111
Molecular Orbital Based Design Guidelines for Hypergolic Energetic Ionic Liquids
2015-01-01
energy content of the anion must also be taken into account in the design strategy ; substitution should be carried out in such a way that does not...substitution strategy . So far in the litera- ture, HP (with energy gap similar to DCA) is the lowest DHf anion (661.9 kJmol1) for which EIL hypergolicity...T. Nakajima, Y. Honda , O. Kitao, H. Nakai, M. Klene, X. Li, J. E. Knox, H. P. Hratchian, J. B. Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts
Assessing Possible Improvements in NATO’s Non-Strategic Nuclear Deterrence Forces
2017-12-01
QUESTION Currently, the only U.S. nuclear weapon based in Europe is the B-61 gravity bomb . The B-61 could be delivered by U.S. and Allied fighter-bomber...currently consists of only air-delivered B-61 gravity bombs . This thesis therefore addresses a little- studied topic of growing importance. Literature on...Postgraduate School, 1989), 53–4, http://hdl.handle.net/10945/29008. 6 would not be possible when using DCA to deliver a B-61 gravity bomb
Picosecond Nonlinear Resonant Interactions in Semiconductors.
1986-03-01
8217 ON PE00O *AUMES A f~?TR. 84 % % AV w, DCA .0 t Z~ amMS N % DC% -i S-A,%G ’- Z.- _ if pe’scov’ 6C. A0CORESS ’Cif, staff and lip Code 7b ADDRESS -C...ROM 01Jan83 To~lPec 8 3 11’ 16. SUPPLEMENTARY NO0TATION 117 COSATI COOES 1It SUBJECT TERMS lContinue on muert 4f "acemaviiY and ideiffifiY by biock