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Sample records for carcinogenicity model content

  1. A mechanism-mediated model for carcinogenicity: model content and prediction of the outcome of rodent carcinogenicity bioassays currently being conducted on 25 organic chemicals.

    OpenAIRE

    Purdy, R.

    1996-01-01

    A hierarchical model consisting of quantitative structure-activity relationships based mainly on chemical reactivity was developed to predict the carcinogenicity of organic chemicals to rodents. The model is comprised of quantitative structure-activity relationships, QSARs based on hypothesized mechanisms of action, metabolism, and partitioning. Predictors included octanol/water partition coefficient, molecular size, atomic partial charge, bond angle strain, atomic acceptor delocalizibility, ...

  2. Understanding arsenic carcinogenicity by the use of animal models

    International Nuclear Information System (INIS)

    Although numerous epidemiological studies have indicated that human arsenic exposure is associated with increased incidences of bladder, liver, skin, and lung cancers, limited attempts have been made to understand mechanisms of carcinogenicity using animal models. Dimethylarsinic acid (DMA), an organic arsenic compound, is a major metabolite of ingested inorganic arsenics in mammals. Recent in vitro studies have proven DMA to be a potent clastogenic agent, capable of inducing DNA damage including double strand breaks and cross-link formation. In our attempts to clarify DMA carcinogenicity, we have recently shown carcinogenic effects of DMA and its related metabolites using various experimental protocols in rats and mice: (1) a multi-organ promotion bioassay in rats; (2) a two-stage promotion bioassay by DMA of rat urinary bladder and liver carcinogenesis; (3) a 2-year carcinogenicity test of DMA in rats; (4) studies on the effects of DMA on lung carcinogenesis in rats; (5) promotion of skin carcinogenesis by DMA in keratin (K6)/ornithine decarboxylase (ODC) transgenic mice; (6) carcinogenicity of DMA in p53(+/-) knockout and Mmh/8-OXOG-DNA glycolase (OGG1) mutant mice; (7) promoting effects of DMA and related organic arsenicals in rat liver; (8) promoting effects of DMA and related organic arsenicals in a rat multi-organ carcinogenesis test; and (9) 2-year carcinogenicity tests of monomethylarsonic acid (MMA) and trimethylarsine oxide (TMAO) in rats. The results revealed that the adverse effects of arsenic occurred either by promoting and initiating carcinogenesis. These data, as covered in the present review, suggest that several mechanisms may be involved in arsenic carcinogenesis

  3. Carcinogen specific dosimetry model for passive smokers of various ages

    International Nuclear Information System (INIS)

    Studies indicate that being exposed to second hand smoke increases the chance of developing lung cancer. Understanding the deposition of carcinogenic particles present in second hand smoke is necessary to understand the development of specific histologic type cancers. In this study, a deposition model is presented for subjects of various ages exposed to sidestream smoke. The model included particle dynamics of coagulation, hygroscopic growth, charge and cloud behavior. Concentrations were varied from the maximum measured indoor concentrations (106 particles/cm3) to what would be expected from wisps of smoke (108 particles/cm3). Model results agreed well with experimental data taken from human subject deposition measurements (four studies). The model results were used to determine the dose intensity (dose per unit airway surface area) of Benzo[a]pyrene (BaP) in the respiratory tract for subjects of various ages. Model predictions for BaP surface concentration on the airway walls paralleled incident rates of tumors by location in the upper tracheobronchial region. Mass deposition efficiency was found to be larger for younger subjects, consistent with diffusion being the predominant mechanism for this particle size range. However, the actual dose intensity of BaP was found to be smaller for children than adults. This occurred due to the predominant effect of the smaller initial inhaled mass for children resulting from smaller tidal volumes. The resulting model is a useful tool to predict carcinogen specific particle deposition

  4. Predicting carcinogenicity of diverse chemicals using probabilistic neural network modeling approaches

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Kunwar P., E-mail: kpsingh_52@yahoo.com [Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research, New Delhi (India); Environmental Chemistry Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001 (India); Gupta, Shikha; Rai, Premanjali [Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research, New Delhi (India); Environmental Chemistry Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001 (India)

    2013-10-15

    Robust global models capable of discriminating positive and non-positive carcinogens; and predicting carcinogenic potency of chemicals in rodents were developed. The dataset of 834 structurally diverse chemicals extracted from Carcinogenic Potency Database (CPDB) was used which contained 466 positive and 368 non-positive carcinogens. Twelve non-quantum mechanical molecular descriptors were derived. Structural diversity of the chemicals and nonlinearity in the data were evaluated using Tanimoto similarity index and Brock–Dechert–Scheinkman statistics. Probabilistic neural network (PNN) and generalized regression neural network (GRNN) models were constructed for classification and function optimization problems using the carcinogenicity end point in rat. Validation of the models was performed using the internal and external procedures employing a wide series of statistical checks. PNN constructed using five descriptors rendered classification accuracy of 92.09% in complete rat data. The PNN model rendered classification accuracies of 91.77%, 80.70% and 92.08% in mouse, hamster and pesticide data, respectively. The GRNN constructed with nine descriptors yielded correlation coefficient of 0.896 between the measured and predicted carcinogenic potency with mean squared error (MSE) of 0.44 in complete rat data. The rat carcinogenicity model (GRNN) applied to the mouse and hamster data yielded correlation coefficient and MSE of 0.758, 0.71 and 0.760, 0.46, respectively. The results suggest for wide applicability of the inter-species models in predicting carcinogenic potency of chemicals. Both the PNN and GRNN (inter-species) models constructed here can be useful tools in predicting the carcinogenicity of new chemicals for regulatory purposes. - Graphical abstract: Figure (a) shows classification accuracies (positive and non-positive carcinogens) in rat, mouse, hamster, and pesticide data yielded by optimal PNN model. Figure (b) shows generalization and predictive

  5. Recent developments in the multistage modeling of cohort data for carcinogenic risk assessment.

    OpenAIRE

    Mazumdar, S; Redmond, C K; Costantino, J P; Patwardhan, R N; Zhou, S. Y.

    1991-01-01

    The modeling of cohort data based on the Armitage-Doll multistage model of the carcinogenic process has gained popular acceptance as a methodology for quantitative risk assessment for estimating the dose-related relationships between different occupational and environmental carcinogenic exposures and cancer mortality. The multistage model can be used for extrapolation to low doses relevant for setting environmental standards and also provides information regarding whether more than one stage ...

  6. Rodent Carcinogenicity Dataset

    OpenAIRE

    Fjodorova, Natalja; Novič, Marjana

    2013-01-01

    The rodent carcinogenicity dataset was compiled from the Carcinogenic Potency Database (CPDBAS) and was applied for the classification of quantitative structure-activity relationship (QSAR) models for the prediction of carcinogenicity based on the counter-propagation artificial neural network (CP ANN) algorithm. The models were developed within EU-funded project CAESAR for regulatory use. The dataset contains the following information: common information about chemicals (ID, chemical name, an...

  7. On use of the multistage dose-response model for assessing laboratory animal carcinogenicity

    OpenAIRE

    Nitcheva, Daniella; Piegorsch, Walter W.; West, R. Webster

    2007-01-01

    We explore how well a statistical multistage model describes dose-response patterns in laboratory animal carcinogenicity experiments from a large database of quantal response data. The data are collected from the U.S. EPA’s publicly available IRIS data warehouse and examined statistically to determine how often higher-order values in the multistage predictor yield significant improvements in explanatory power over lower-order values. Our results suggest that the addition of a second-order par...

  8. Tobacco, Microbes, and Carcinogens: Correlation Between Tobacco Cure Conditions, Tobacco-Specific Nitrosamine Content, and Cured Leaf Microbial Community.

    Science.gov (United States)

    Law, Audrey D; Fisher, Colin; Jack, Anne; Moe, Luke A

    2016-07-01

    Tobacco-specific nitrosamines are carcinogenic N-nitrosamine compounds present at very low levels in freshly harvested tobacco leaves that accumulate during leaf curing. Formation of N-nitrosamine compounds is associated with high nitrate levels in the leaf at harvest, and nitrate is presumed to be the source from which the N-nitrosation species originates. More specifically, nitrite is considered to be a direct precursor, and nitrite is linked with N-nitrosation in many environmental matrices where it occurs via microbial nitrate reduction. Here, we initiate work exploring the role of leaf microbial communities in formation of tobacco-specific nitrosamines. Leaves from burley tobacco line TN90H were air cured under various temperature and relative humidity levels, and 22 cured tobacco samples were analyzed for their microbial communities and leaf chemistry. Analysis of nitrate, nitrite, and total tobacco-specific nitrosamine levels revealed a strong positive correlation between the three variables, as well as a strong positive correlation with increasing relative humidity during cure conditions. 16S rRNA gene amplicon sequencing was used to assess microbial communities in each of the samples. In most samples, Proteobacteria predominated at the phylum level, accounting for >90 % of the OTUs. However, a distinct shift was noted among members of the high tobacco-specific nitrosamine group, with increases in Firmicutes and Actinobacteria. Several OTUs were identified that correlate strongly (positive and negative) with tobacco-specific nitrosamine content. Copy number of bacterial nitrate reductase genes, obtained using quantitative PCR, did not correlate strongly with tobacco-specific nitrosamine content. Incomplete denitrification is potentially implicated in tobacco-specific nitrosamine levels. PMID:27023797

  9. Application of the two-stage clonal expansion model in characterizing the joint effect of exposure to two carcinogens

    International Nuclear Information System (INIS)

    In this paper, we describe application of the two-stage clonal expansion model to characterize the joint effect of exposure to two carcinogens. This biologically based model of carcinogenesis provides a useful framework for the quantitative description of carcinogenic risks and for defining agents that act as initiators, promoters, and completers. Depending on the mechanism of action, the agent-specific relative risk following exposure to two carcinogens can be additive, multiplicative, or supramultiplicative, with supra-additive relative risk indicating a synergistic effect between the two agents. Maximum-likelihood methods for fitting the two-stage clonal expansion model with intermittent exposure to two carcinogens are described and illustrated, using data on lung-cancer mortality among Colorado uranium miners exposed to both radon and tobacco smoke

  10. Prediction of rodent carcinogenic potential of naturally occurring chemicals in the human diet using high-throughput QSAR predictive modeling

    International Nuclear Information System (INIS)

    Consistent with the U.S. Food and Drug Administration (FDA) Critical Path Initiative, predictive toxicology software programs employing quantitative structure-activity relationship (QSAR) models are currently under evaluation for regulatory risk assessment and scientific decision support for highly sensitive endpoints such as carcinogenicity, mutagenicity and reproductive toxicity. At the FDA's Center for Food Safety and Applied Nutrition's Office of Food Additive Safety and the Center for Drug Evaluation and Research's Informatics and Computational Safety Analysis Staff (ICSAS), the use of computational SAR tools for both qualitative and quantitative risk assessment applications are being developed and evaluated. One tool of current interest is MDL-QSAR predictive discriminant analysis modeling of rodent carcinogenicity, which has been previously evaluated for pharmaceutical applications by the FDA ICSAS. The study described in this paper aims to evaluate the utility of this software to estimate the carcinogenic potential of small, organic, naturally occurring chemicals found in the human diet. In addition, a group of 19 known synthetic dietary constituents that were positive in rodent carcinogenicity studies served as a control group. In the test group of naturally occurring chemicals, 101 were found to be suitable for predictive modeling using this software's discriminant analysis modeling approach. Predictions performed on these compounds were compared to published experimental evidence of each compound's carcinogenic potential. Experimental evidence included relevant toxicological studies such as rodent cancer bioassays, rodent anti-carcinogenicity studies, genotoxic studies, and the presence of chemical structural alerts. Statistical indices of predictive performance were calculated to assess the utility of the predictive modeling method. Results revealed good predictive performance using this software's rodent carcinogenicity module of over 1200 chemicals

  11. Formation of carcinogenic 4(5)-methylimidazole in caramel model systems: a role of sulphite.

    Science.gov (United States)

    Lee, Kwang-Geun; Jang, Haewon; Shibamoto, Takayuki

    2013-02-15

    Aqueous caramel model systems consisted the D-glucose/NH(3)/sulphite were heated at 100°C for 2 h and amounts of carcinogenic 4(5)-methylimidazole (4-MI) formed were determined. The amount formed ranged from 7.0 to 155.0 ppm. A system with 0.1 M sulphite yielded the greatest amount of 4-MI, which was 54% more than that yielded from a system without sulphite. When the amount of sulphite increased over 0.1 M, the amount of 4-MI reduced. The greatest reduction was achieved with 0.2 M sulphite by 68% compared to 0 M sulphite, suggesting that sulphite plays an important role in the formation of carcinogenic 4-MI in caramel colour. Also, a system with 0.1 M sulphite yielded the most intense caramel colour but the other levels of sulphite did not change the colour intensity significantly. Sulphite contributed slightly to the level of flavour chemicals evaluated using pyrazine formation. The results suggest that sulphite addition at appropriate amount reduces 4-MI formation in caramel colour without sacrificing flavour and colour formation. PMID:23194510

  12. Antiproliferative effects of fluoxetine on colon cancer cells and in a colonic carcinogen mouse model.

    Directory of Open Access Journals (Sweden)

    Vinicius Kannen

    Full Text Available The antidepressant fluoxetine has been under discussion because of its potential influence on cancer risk. It was found to inhibit the development of carcinogen-induced preneoplastic lesions in colon tissue, but the mechanisms of action are not well understood. Therefore, we investigated anti-proliferative effects, and used HT29 colon tumor cells in vitro, as well as C57BL/6 mice exposed to intra-rectal treatment with the carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG as models. Fluoxetine increased the percentage of HT29 cells in the G(0/G(1 phase of cell-cycle, and the expression of p27 protein. This was not related to an induction of apoptosis, reactive oxygen species or DNA damage. In vivo, fluoxetine reduced the development of MNNG-induced dysplasia and vascularization-related dysplasia in colon tissue, which was analyzed by histopathological techniques. An anti-proliferative potential of fluoxetine was observed in epithelial and stromal areas. It was accompanied by a reduction of VEGF expression and of the number of cells with angiogenic potential, such as CD133, CD34, and CD31-positive cell clusters. Taken together, our findings suggest that fluoxetine treatment targets steps of early colon carcinogenesis. This confirms its protective potential, explaining at least partially the lower colon cancer risk under antidepressant therapy.

  13. Evaluation of the E mu-pim-1 transgenic mouse model for short-term carcinogenicity testing

    DEFF Research Database (Denmark)

    van Kreijl, C. F.; van Oordt, C. W. V.; Kroese, E. D.; Sørensen, Ilona Kryspin; Breuer, M. L.; Storer, R. D.

    1998-01-01

    present article, the results from 2 recent short-term assays (with mitomycin C and x-rays) are briefly presented, together with a review of all 11 performed bioassays and their corresponding histopathologic and molecular data. The overall results allow the first evaluation of the E mu-pim-1 mouse model...... with regard to its usefulness in short-term carcinogenicity testing. It has been shown that the model is primarily suitable as a sensitive short-term assay for genotoxic carcinogens that not only induce (at least) gene mutations and/or large deletions and rearrangements but that also sufficiently...

  14. Statistical Model for Content Extraction

    DEFF Research Database (Denmark)

    Qureshi, Pir Abdul Rasool; Memon, Nasrullah

    2011-01-01

    We present a statistical model for content extraction from HTML documents. The model operates on Document Object Model (DOM) tree of the corresponding HTML document. It evaluates each tree node and associated statistical features to predict significance of the node towards overall content...

  15. Modelling the effect of exposure to environmetal carcinogens on incidence of cancers in populations

    International Nuclear Information System (INIS)

    Risk estimation is a complex problem with very important public health consequences. The models in general use for this purpose are simple models that describe some measure of risk as a mathematically simple function of exposure. The available data about environmental carcinogens, however, is rarely enough to allow the authors to test the validity of such models. A solution to this problem is to choose a model that agrees with the understanding of carcinogenesis and exposure effects. Here, exposure effects are modelled quantitative in the framework of a model for carcinogenesis at the cellular level proposed by Moolgavkar and Knudson (1981). The model postulates that a normal cell must undergo two changes before it becomes malignant. It also allows for growth of normal tissue, intermediate cell clones and malignant tumors. Derivations of hazards and relative risks based on various patterns (acute, chronic) and qualities (initiators, promoters) of exposure are shown. The use of such models for data analysis is illustrated on two sets of data: one on acute exposure to γ-rays in an animal carcinogensis experiment; the other on a chronic exposure to arsenic in a cohort of workers from a copper smelter. Results from the analysis are compared to those obtained with standard methods of risk estimation

  16. Modelling prokaryote gene content

    Directory of Open Access Journals (Sweden)

    Edward Susko

    2006-01-01

    Full Text Available The patchy distribution of genes across the prokaryotes may be caused by multiple gene losses or lateral transfer. Probabilistic models of gene gain and loss are needed to distinguish between these possibilities. Existing models allow only single genes to be gained and lost, despite the empirical evidence for multi-gene events. We compare birth-death models (currently the only widely-used models, in which only one gene can be gained or lost at a time to blocks models (allowing gain and loss of multiple genes within a family. We analyze two pairs of genomes: two E. coli strains, and the distantly-related Archaeoglobus fulgidus (archaea and Bacillus subtilis (gram positive bacteria. Blocks models describe the data much better than birth-death models. Our models suggest that lateral transfers of multiple genes from the same family are rare (although transfers of single genes are probably common. For both pairs, the estimated median time that a gene will remain in the genome is not much greater than the time separating the common ancestors of the archaea and bacteria. Deep phylogenetic reconstruction from sequence data will therefore depend on choosing genes likely to remain in the genome for a long time. Phylogenies based on the blocks model are more biologically plausible than phylogenies based on the birth-death model.

  17. Development of quantitative structure-activity relationship (QSAR) models to predict the carcinogenic potency of chemicals

    International Nuclear Information System (INIS)

    Determining the carcinogenicity and carcinogenic potency of new chemicals is both a labor-intensive and time-consuming process. In order to expedite the screening process, there is a need to identify alternative toxicity measures that may be used as surrogates for carcinogenic potency. Alternative toxicity measures for carcinogenic potency currently being used in the literature include lethal dose (dose that kills 50% of a study population [LD50]), lowest-observed-adverse-effect-level (LOAEL) and maximum tolerated dose (MTD). The purpose of this study was to investigate the correlation between tumor dose (TD50) and three alternative toxicity measures as an estimator of carcinogenic potency. A second aim of this study was to develop a Classification and Regression Tree (CART) between TD50 and estimated/experimental predictor variables to predict the carcinogenic potency of new chemicals. Rat TD50s of 590 structurally diverse chemicals were obtained from the Cancer Potency Database, and the three alternative toxicity measures considered in this study were estimated using TOPKAT, a toxicity estimation software. Though poor correlations were obtained between carcinogenic potency and the three alternative toxicity (both experimental and TOPKAT) measures for the CPDB chemicals, a CART developed using experimental data with no missing values as predictor variables provided reasonable estimates of TD50 for nine chemicals that were part of an external validation set. However, if experimental values for the three alternative measures, mutagenicity and logP are not available in the literature, then either the CART developed using missing experimental values or estimated values may be used for making a prediction

  18. Direct spectral analysis and determination of high content of carcinogenic bromine in bread using UV pulsed laser induced breakdown spectroscopy.

    Science.gov (United States)

    Mehder, A O; Gondal, Mohammed A; Dastageer, Mohamed A; Habibullah, Yusuf B; Iqbal, Mohammed A; Oloore, Luqman E; Gondal, Bilal

    2016-06-01

    Laser induced breakdown spectroscopy (LIBS) was applied for the detection of carcinogenic elements like bromine in four representative brands of loaf bread samples and the measured bromine concentrations were 352, 157, 451, and 311 ppm, using Br I (827.2 nm) atomic transition line as the finger print atomic transition. Our LIBS system is equipped with a pulsed laser of wavelength 266 nm with energy 25 mJ pulse(-1), 8 ns pulse duration, 20 Hz repetition rate, and a gated ICCD camera. The LIBS system was calibrated with the standards of known concentrations in the sample (bread) matrix and such plot is linear in 20-500 ppm range. The capability of our system in terms of limit of detection and relative accuracy with respect to the standard inductively coupled plasma mass spectrometry (ICPMS) technique was evaluated and these values were 5.09 ppm and 0.01-0.05, respectively, which ensures the applicability of our system for Br trace level detection, and LIBS results are in excellent agreement with that of ICPMS results. PMID:26950676

  19. Hybrid Model of Content Extraction

    DEFF Research Database (Denmark)

    Qureshi, Pir Abdul Rasool; Memon, Nasrullah

    2012-01-01

    We present a hybrid model for content extraction from HTML documents. The model operates on Document Object Model (DOM) tree of the corresponding HTML document. It evaluates each tree node and associated statistical features like link density and text distribution across the node to predict...... significance of the node towards overall content provided by the document. Once significance of the nodes is determined, the formatting characteristics like fonts, styles and the position of the nodes are evaluated to identify the nodes with similar formatting as compared to the significant nodes. The proposed...... hybrid model is derived from two different models, i.e., one is based on statistical features and other on formatting characteristics and achieved the best accuracy. We describe the validity of model with the help of experiments conducted on the standard data sets. The results revealed that the proposed...

  20. Source apportionment of the carcinogenic potential of polycyclic aromatic hydrocarbons (PAH) associated to airborne PM10 by a PMF model.

    Science.gov (United States)

    Callén, M S; Iturmendi, A; López, J M; Mastral, A M

    2014-02-01

    In order to perform a study of the carcinogenic potential of polycyclic aromatic hydrocarbons (PAH), benzo(a)pyrene equivalent (BaP-eq) concentration was calculated and modelled by a receptor model based on positive matrix factorization (PMF). Nineteen PAH associated to airborne PM10 of Zaragoza, Spain, were quantified during the sampling period 2001-2009 and used as potential variables by the PMF model. Afterwards, multiple linear regression analysis was used to quantify the potential sources of BaP-eq. Five sources were obtained as the optimal solution and vehicular emission was identified as the main carcinogenic source (35 %) followed by heavy-duty vehicles (28 %), light-oil combustion (18 %), natural gas (10 %) and coal combustion (9 %). Two of the most prevailing directions contributing to this carcinogenic character were the NE and N directions associated with a highway, industrial parks and a paper factory. The lifetime lung cancer risk exceeded the unit risk of 8.7 x 10(-5) per ng/m(3) BaP in both winter and autumn seasons and the most contributing source was the vehicular emission factor becoming an important issue in control strategies. PMID:24022101

  1. Acrylamide carcinogenicity.

    Science.gov (United States)

    Klaunig, James E

    2008-08-13

    The induction of cancer by chemicals is a multiple-stage process. Acrylamide is carcinogenic to experimental mice and rats, causing tumors at multiple organ sites in both species when given in drinking water or by other means. In mice, acrylamide increased the incidence and multiplicity of lung tumors and skin tumors. In two bioassays in rats, acrylamide administered in drinking water consistently induced mesotheliomas of the testes, thyroid tumors, and mammary gland tumors. In addition, brain tumors appeared to be increased. In one of the rat bioassays, pituitary tumors, pheochromocytomas, uterine tumors, and pituitary tumors were noted. The conversion of acrylamide metabolically to the reactive, mutagenic, and genotoxic product, glycidamide, can occur in both rodent and humans. Glycidamide and frequently acrylamide have been positive for mutagenicity and DNA reactivity in a number of in vitro and in vivo assays. The effects of chronic exposure of glycidamide to rodents have not been reported. Epidemiologic studies of workers for possible health effects from exposures to acrylamide have not shown a consistent increase in cancer risk. Although an increase in the risk for pancreatic cancer (almost double) was seen in highly exposed workers, no exposure response relationship could be determined. The mode of action remains unclear for acrylamide-induced rodent carcinogenicity, but support for a genotoxic mechanism based on in vitro and in vivo DNA reactivity assays cannot be ruled out. In addition, the pattern of tumor formation in the rat following chronic exposure supports a genotoxic mode of action but also suggests a potential role of endocrine modification. PMID:18624430

  2. Evaluation of the E mu-pim-1 transgenic mouse model for short-term carcinogenicity testing

    DEFF Research Database (Denmark)

    van Kreijl, C. F.; van Oordt, C. W. V.; Kroese, E. D.; Sørensen, Ilona Kryspin; Breuer, M. L.; Storer, R. D.

    1998-01-01

    The value of the chronic rodent carcinogenicity assay in adequately predicting cancer risk in humans has become a matter of debate over the past few years. Therefore, more rapid and accurate alternative tests are urgently needed. Transgenic mouse models, those harboring genetic changes that are...... relevant to the multistage cancer process, may provide such alternative tests. Transgenic E mu-pim-1 mice, developed by Berns and coworkers in 1989, contain the pim-1 oncogene, which is expressed at elevated levels in their lymphoid compartments. As a result, these mice are predisposed to the development...

  3. Alternative Toxicity Testing: Analyses on Skin Sensitization, ToxCast Phases I and II, and Carcinogenicity Provide Indications on How to Model Mechanisms Linked to Adverse Outcome Pathways.

    Science.gov (United States)

    Benigni, Romualdo; Battistelli, Chiara Laura; Bossa, Cecilia; Giuliani, Alessandro; Tcheremenskaia, Olga

    2015-01-01

    This article studies alternative toxicological approaches, with new (skin sensitization, ToxCast) and previous (carcinogenicity) analyses. Quantitative modeling of rate-limiting steps in skin sensitization and carcinogenicity predicts the majority of toxicants. Similarly, successful (Quantitative) Structure-Activity Relationships models exploit the quantification of only one, or few rate-limiting steps. High-throughput assays within ToxCast point to promising associations with endocrine disruption, whereas markers for pathways intermediate events have limited correlation with most endpoints. Since the pathways may be very different (often not simple linear chains of events), quantitative analysis is necessary to identify the type of mechanism and build the appropriate model. PMID:26398111

  4. Evaluation of the Xpa-deficient transgenic mouse model for short-term carcinogenicity testing: 9-month studies with haloperidol, reserpine, phenacetin, and D-mannitol.

    Science.gov (United States)

    Lina, Ben A R; Woutersen, Ruud A; Bruijntjes, Joost P; van Benthem, Jan; van den Berg, Jolanda A H; Monbaliu, Johan; Thoolen, Bob J J M; Beems, Rudolf B; van Kreijl, Coen F

    2004-01-01

    As part of the international evaluation program coordinated by ILSI/HESI, the potential of DNA repair deficient Xpa-/- mice and the double knockout Xpa-/-.p53+/- mice for short term carcinogenicity assays was evaluated. For comparison also wild-type C57BL/6 mice (WT) were included in these studies. Four test compounds were administered to groups of 15 male and 15 female Xpa-/- mice, Xpa-/-.p53+/- mice and WT mice for 39 weeks. The model compounds investigated were haloperidol, reserpine (nongenotoxic rodent carcinogens, putative human noncarcinogens), phenacetin (genotoxic rodent carcinogen, suspected human carcinogen), and D-mannitol (noncarcinogen in rodents and humans). The test compounds were administered as admixture to rodent diet at levels up to 25 mg/kg diet for haloperidol, 7.5 mg/kg diet for reserpine, 0.75% for phenacetin, and 10% for D-mannitol. These levels included the maximum tolerable dose (MTD). Survival was not affected with any of the test compounds. Haloperidol, reserpine and D-mannitol were negative in the carcinogenicity assay with Xpa-/- and Xpa-/-.p53+/- mice, showing low and comparable tumor incidences in controls and high-dose animals. The results obtained with phenacetin may be designated equivocal in Xpa-/-.p53+/- mice, based on the occurrence of a single rare tumor in the target organ (kidney) accompanied by a low incidence of hyperplastic renal lesions and a high incidence of karyomegaly. These results are in agreement with the currently known carcinogenic potential of the 4 test compounds in humans. PMID:15200157

  5. Combining QSAR Modeling and Text-Mining Techniques to Link Chemical Structures and Carcinogenic Modes of Action

    Science.gov (United States)

    Papamokos, George; Silins, Ilona

    2016-01-01

    There is an increasing need for new reliable non-animal based methods to predict and test toxicity of chemicals. Quantitative structure-activity relationship (QSAR), a computer-based method linking chemical structures with biological activities, is used in predictive toxicology. In this study, we tested the approach to combine QSAR data with literature profiles of carcinogenic modes of action automatically generated by a text-mining tool. The aim was to generate data patterns to identify associations between chemical structures and biological mechanisms related to carcinogenesis. Using these two methods, individually and combined, we evaluated 96 rat carcinogens of the hematopoietic system, liver, lung, and skin. We found that skin and lung rat carcinogens were mainly mutagenic, while the group of carcinogens affecting the hematopoietic system and the liver also included a large proportion of non-mutagens. The automatic literature analysis showed that mutagenicity was a frequently reported endpoint in the literature of these carcinogens, however, less common endpoints such as immunosuppression and hormonal receptor-mediated effects were also found in connection with some of the carcinogens, results of potential importance for certain target organs. The combined approach, using QSAR and text-mining techniques, could be useful for identifying more detailed information on biological mechanisms and the relation with chemical structures. The method can be particularly useful in increasing the understanding of structure and activity relationships for non-mutagens.

  6. Formation and reduction of carcinogenic furan in various model systems containing food additives.

    Science.gov (United States)

    Kim, Jin-Sil; Her, Jae-Young; Lee, Kwang-Geun

    2015-12-15

    The aim of this study was to analyse and reduce furan in various model systems. Furan model systems consisting of monosaccharides (0.5M glucose and ribose), amino acids (0.5M alanine and serine) and/or 1.0M ascorbic acid were heated at 121°C for 25 min. The effects of food additives (each 0.1M) such as metal ions (iron sulphate, magnesium sulphate, zinc sulphate and calcium sulphate), antioxidants (BHT and BHA), and sodium sulphite on the formation of furan were measured. The level of furan formed in the model systems was 6.8-527.3 ng/ml. The level of furan in the model systems of glucose/serine and glucose/alanine increased 7-674% when food additives were added. In contrast, the level of furan decreased by 18-51% in the Maillard reaction model systems that included ribose and alanine/serine with food additives except zinc sulphate. PMID:26190608

  7. Genetic modelling of PIM proteins in cancer: proviral tagging, cooperation with oncogenes, tumor suppressor genes and carcinogens.

    Directory of Open Access Journals (Sweden)

    CarmenBlanco Aparicio

    2014-05-01

    Full Text Available The PIM proteins, which were initially discovered as proviral insertion sites in Moloney murine leukemia virus infection, are a family of highly homologous serine/threonine kinases that have been reported to be overexpressed in hematological malignancies and solid tumors. The PIM proteins have also been associated with metastasis and overall treatment responses and implicated in the regulation of apoptosis, metabolism, the cell cycle, and homing and migration, which makes these proteins interesting targets for anticancer drug discovery. The use of retroviral insertional mutagenesis and refined approaches such as complementation tagging has allowed the identification of myc, pim and a third group of genes (including bmi1 and gfi1 as complementing genes in lymphomagenesis. Moreover, mouse modeling of human cancer has provided an understanding of the molecular pathways that are involved in tumor initiation and progression at the physiological level. In particular, genetically modified mice have allowed researchers to further elucidate the role of each of the Pim isoforms in various tumor types. PIM kinases have been identified as weak oncogenes because experimental overexpression in lymphoid tissue, prostate and liver induces tumors at a relatively low incidence and with a long latency. However, very strong synergistic tumorigenicity between Pim1/2 and c-Myc and other oncogenes has been observed in lymphoid tissues. Mouse models have also been used to study whether the inhibition of specific PIM isoforms is required to prevent carcinogen-induced sarcomas, indicating that the absence of Pim2 and Pim3 greatly reduces sarcoma growth and bone invasion; the extent of this effect is similar to that observed in the absence of all 3 isoforms. This review will summarize some of the animal models that have been used to understand the isoform-specific contribution of PIM kinases to tumorigenesis.

  8. Role of metabolic activation in the carcinogenicity of estrogens: studies in an animal liver tumor model.

    OpenAIRE

    Metzler, M; Blaich, G; Tritscher, A M

    1990-01-01

    Male Syrian golden hamsters chronically exposed to certain synthetic estrogens such as diethylstilbestrol (DES) or 17 alpha-ethinylestradiol (EE2) and fed a diet containing 7,8-benzoflavone (BF) develop a high incidence of liver tumors. No such tumors are found in animals treated with estrogen or BF alone. To clarify the role of metabolic activation of the estrogen and BF in the mechanism of hepatocarcinogenesis in this animal model, the effects of pretreatment with DES and EE2 alone and in c...

  9. Applications of the human p53 knock-in (Hupki) mouse model for human carcinogen testing

    OpenAIRE

    Besaratinia, Ahmad; Pfeifer, Gerd P

    2010-01-01

    Tumor-driving mutations in the TP53 gene occur frequently in human cancers. These inactivating mutations arise predominantly from a single-point mutation in the DNA-binding domain of this tumor suppressor gene (i.e., exons 4–9). The human p53 knock-in (Hupki) mouse model was constructed using gene-targeting technology to create a mouse strain that harbors human wild-type TP53 DNA sequences in both copies of the mouse TP53 gene. Replacement of exons 4–9 of the endogenous mouse TP53 alleles in ...

  10. Feature Analysis for Modeling Game Content Quality

    DEFF Research Database (Denmark)

    Shaker, Noor; Yannakakis, Georgios N.; Togelius, Julian

    2011-01-01

    ’ preferences, and by defining the smallest game session size for which the model can still predict reported emotion with acceptable accuracy. Neuroevolutionary preference learning is used to approximate the function from game content to reported emotional preferences. The experiments are based on a modified...

  11. Current and emerging challenges in toxicopathology: Carcinogenic threshold of phenobarbital and proof of arsenic carcinogenicity using rat medium-term bioassays for carcinogens

    International Nuclear Information System (INIS)

    For the last 25 years, Prof. Nobuyuki Ito and his laboratory have focused on the development of liver medium-term bioassay system for detection of carcinogens in F344 rats utilizing glutathione S-transferase placental form (GST-P)-positive foci as an end point marker. In this presentation, the outline and samples of medium-term bioassay systems were described. Furthermore, our data demonstrated the presence of a threshold for the non-genotoxic carcinogen, phenobarbital (PB), and the lack of linearity in the low-dose area of the dose-response curve, providing evidence for hormesis. In addition, the establishment and applications of multiorgan carcinogenicity bioassay (DMBDD model), used for the examination of the carcinogenicity of genotoxic and non-genotoxic chemicals, are discussed. Dimethylarsinic acid, one of organic arsenics, was found to be carcinogenic in rat bladder using DMBDD model and carcinogenicity test

  12. Probabilistic models for CRISPR spacer content evolution

    OpenAIRE

    Kupczok, Anne; Bollback, Jonathan P

    2013-01-01

    Background The CRISPR/Cas system is known to act as an adaptive and heritable immune system in Eubacteria and Archaea. Immunity is encoded in an array of spacer sequences. Each spacer can provide specific immunity to invasive elements that carry the same or a similar sequence. Even in closely related strains, spacer content is very dynamic and evolves quickly. Standard models of nucleotide evolution cannot be applied to quantify its rate of change since processes other than single nucleotide ...

  13. Procedural Content Graphs for Urban Modeling

    Directory of Open Access Journals (Sweden)

    Pedro Brandão Silva

    2015-01-01

    Full Text Available Massive procedural content creation, for example, for virtual urban environments, is a difficult, yet important challenge. While shape grammars are a popular example of effectiveness in architectural modeling, they have clear limitations regarding readability, manageability, and expressive power when addressing a variety of complex structural designs. Moreover, shape grammars aim at geometry specification and do not facilitate integration with other types of content, such as textures or light sources, which could rather accompany the generation process. We present procedural content graphs, a graph-based solution for procedural generation that addresses all these issues in a visual, flexible, and more expressive manner. Besides integrating handling of diverse types of content, this approach introduces collective entity manipulation as lists, seamlessly providing features such as advanced filtering, grouping, merging, ordering, and aggregation, essentially unavailable in shape grammars. Hereby, separated entities can be easily merged or just analyzed together in order to perform a variety of context-based decisions and operations. The advantages of this approach are illustrated via examples of tasks that are either very cumbersome or simply impossible to express with previous grammar approaches.

  14. Beryllium: genotoxicity and carcinogenicity

    International Nuclear Information System (INIS)

    Beryllium (Be) has physical-chemical properties, including low density and high tensile strength, which make it useful in the manufacture of products ranging from space shuttles to golf clubs. Despite its utility, a number of standard setting agencies have determined that beryllium is a carcinogen. Only a limited number of studies, however, have addressed the underlying mechanisms of the carcinogenicity and mutagenicity of beryllium. Importantly, mutation and chromosomal aberration assays have yielded somewhat contradictory results for beryllium compounds and whereas bacterial tests were largely negative, mammalian test systems showed evidence of beryllium-induced mutations, chromosomal aberrations, and cell transformation. Although inter-laboratory differences may play a role in the variability observed in genotoxicity assays, it is more likely that the different chemical forms of beryllium have a significant effect on mutagenicity and carcinogenicity. Because workers are predominantly exposed to airborne particles which are generated during the machining of beryllium metal, ceramics, or alloys, testing of the mechanisms of the mutagenic and carcinogenic activity of beryllium should be performed with relevant chemical forms of beryllium

  15. Carcinogenic risks of radiations

    International Nuclear Information System (INIS)

    Ionising radiations are known since the end of the 19th century. Early, after being discovered, they were applied in Medicine and the association with an increased number of different malignant tumors was proved. This paper presents a literature review concerning epidemiological proof of radiation induced cancer, molecular mechanisms and factors that increase or decrease the carcinogenic action of ionizing radiations

  16. The value of probabilistic modelling for the estimation of carcinogenic risk at low doses. Application to 2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin (TCDD)

    International Nuclear Information System (INIS)

    The two main different approaches for the determination of carcinogenic risk at low doses of exposure to chemicals are presented, i.e. the threshold model based on the No-Observed-Effect-Level (NOEL) and the non-threshold assumption based on the probabilistic modelling of data. Three statistical models based on the distribution of tolerances in the population are presented and applied to TCDD: Probit, Logit and Extreme-Value model. Two mechanistic models based on assumptions concerning the mechanism of carcinogenesis are presented likewise: the One-Hit and the MultiStage models. Probabilistic modelling present numerous advantages as far as the comparison of risks of chemicals is concerned since it allows for: i) a better characterisation of uncertainty; ii) a comparison of chemicals between themselves for a given model; iii) a comparison of chemicals between themselves for a given model; iii) a comparison of species for a given model; iv) the explicitation of one's preference in the choice of the model and its attributes; v) the explicitation of the accepted excess risk as a basis for decision-making. (author)

  17. Chemistry of carcinogenic metals.

    OpenAIRE

    Martell, A E

    1981-01-01

    The periodic distribution of known and suspected carcinogenic metal ions is described, and the chemical behavior of various types of metal ions is explained in terms of the general theory of hard and soft acids and bases. The chelate effect is elucidated, and the relatively high stability of metal chelates in very dilute solutions is discussed. The concepts employed for the chelate effect are extended to explain the high stabilities of macrocyclic and cryptate complexes. Procedures for the us...

  18. The carcinogenicity of chromium

    OpenAIRE

    Norseth, Tor

    1981-01-01

    The carcinogenicity of chromium compounds is reviewed with specific attention to the gaps in knowledge for risk estimation and research needs. The most important problems at present are whether trivalent chromium compounds cause cancer, and whether there is a difference in cancer causing effects between the soluble and the slightly soluble hexavalent compounds in the practical exposure situation. Dose estimates for risk estimation based on epidemiological investigations are also lacking. Pres...

  19. Carcinogen risk assessment

    International Nuclear Information System (INIS)

    This article describes the methods by which risk factors for carcinogenic hazards are determined and the limitations inherent in the process. From statistical and epidemiological studies, the major identifiable factors related to cancer in the United States were determined to be cigarette smoking, diet, reproductive and sexual behavior, infections, ultraviolet and ionizing radiation, and alcohol consumption. The incidence of lung cancer due to air pollutants was estimated to be less than 2%. Research needs were discussed

  20. Carcinogenic potential of various energy sources

    International Nuclear Information System (INIS)

    Evaluation of the health impacts of different sources of energy should include a comparison of the potential carcinogenic effects of the radioactive and chemical substances produced by various sources. In general, these potential health effects are too small to be measured directly and are therefore estimated by extrapolation, on the basis of a linear dose-response model, from measurable effects at high dose levels. Estimates of the carcinogenic potential of various energy sources available in North America are given in this paper. For most if not all of the energy sources for which data are currently available, it would appear that the known biological benefits in terms of life expectancy greatly outweigh all the potential harm due to carcinogenic (and genetic) effects on human beings, when expressed in the same terms, i.e. life expectancy. (author)

  1. Food derived carcinogenic amnoimidazoazaarenes

    DEFF Research Database (Denmark)

    Frandsen, Henrik

    Carcinogenic aminoimidazoazaarenes are formed during cooking of meat and fish. Important factors for the formation of these compounds are meat type, cooking temperature and time. The compounds are genotoxic in bacterial and mammalian cells. In animal feeding studies the compounds tested so far were...... adducts with DNA. Adducts with 2-deoxyguanosine have been characterized for a number of aminoimidazoazaarenes. Adducts with DNA have also been found in animals after exposure to these compounds. In \\:iw major metabolic detoxification pathways are ring hydroxylation followed by conjugation and conjugation...... of the exocyclic amino group. Estimations of human cancer risk have indicated that ingestion of food containing aminoimidazoazaarenes are of importance....

  2. Carcinogenic potential of hydrotreated petroleum aromatic extracts.

    Science.gov (United States)

    Doak, S M; Hend, R W; van der Wiel, A; Hunt, P F

    1985-06-01

    Five experimental petroleum extracts were produced from luboil distillates derived from Middle East paraffinic crude by solvent extraction and severe hydrotreatment. The polycyclic aromatic content (PCA) of the extracts was determined by dimethyl sulphoxide extraction and ranged from 3.7-9.2% w/w. The five extracts were evaluated for their potential to induce cutaneous and systemic neoplasia in female mice derived from Carworth Farm No 1 strain (CF1). The test substances were applied undiluted (0.2 ml per application) to the shorn dorsal skin twice weekly for up to 78 weeks, with 48 mice in each treatment group and 96 in the untreated control group; two further groups, each of 48 mice, were similarly treated either with a non-hydrotreated commercial aromatic extract (PCA content, 19.7% w/v) or with a low dose of benzo(a)pyrene (12.5 micrograms/ml acetone). The mice were housed individually in polypropylene cages in specified pathogen free conditions. The incidence of cutaneous and systemic tumours was determined from histological analysis of haematoxylin and eosin stained tissue sections. The results were correlated with the PCA content of the extracts and compared with those from female mice exposed to a non-hydrotreated commercial aromatic extract. Four of the hydrotreated extracts were carcinogenic for murine skin; the two products with the lower PCA contents were less carcinogenic than the products with the higher PCA contents and all were less carcinogenic than the commercial extract. One extract with the lowest PCA content was non-carcinogenic. Thus refining by severe hydrotreatment was an effective method of reducing the carcinogenic potential of petroleum aromatic extracts. Although other physicochemical properties may influence the biological activity of oil products, the PCA content determined by dimethyl sulphoxide extraction may be a useful indicator of the potential of oil products to induce cutaneous tumours in experimental animals. There was no

  3. Opportunistic Networking : Mobility Modeling and Content Distribution

    OpenAIRE

    Pajevic, Ljubica

    2013-01-01

    We have witnessed two main trends in recent years that have shaped the current state of communication networks. First, the Internet was designed with the initial idea to provide remote access to resources in the network; today it is overwhelmingly being used for content distribution. In addition, the community of content creators has evolved from a small group of professionals into a global community where every user can generate his contents and share it with other users. Second, the prolife...

  4. Chemical mechanisms of the interaction between radiation and chemical carcinogens

    International Nuclear Information System (INIS)

    There is evidence to suggest that ionizing radiation and chemical carcinogens can act synergistically to produce deleterious biological effects. In addition, many carcinogens undergo metabolic activation in vivo. This activation, initiated by biochemical redox reactions, can be simulated chemically, electrochemically, photochemically and radiation chemically. The principal reactive species formed by the action of ionizing radiation on aqueous solutions of macromolecules and mammalian cells, are hydroxyl radicals and superoxide anions. Pulse and steady-state radiolysis studies of model chemical systems have established that these species can 'activate' chemical carcinogens by a radical oxidation process, and that the resulting activated carcinogens can subsequently react with nucleophilic sites on DNA and other potential target macromolecules. Rate constants for some of the fast reactions involved in the radiation activation of carcinogens and in the subsequent carcinogen-DNA interactions have been determined, together with the yields of radiation-induced covalent DNA-carcinogen binding. A redox models for radiation-induced chemical carcinogenesis is proposed which describes a possible mechanism of action involving free radical species generated in the aqueous cellular milieu, which diffuse to and react with carcinogens located within the micro-environment of the cell. Preliminary experiments suggest that protection against radiation and chemical carcinogenesis can be achieved by radical scavenging or by competitive free radical inhibition

  5. An estimation of the carcinogenic risk associated with the intake of multiple relevant carcinogens found in meat and charcuterie products.

    Science.gov (United States)

    Hernández, Ángel Rodríguez; Boada, Luis D; Almeida-González, Maira; Mendoza, Zenaida; Ruiz-Suárez, Norberto; Valeron, Pilar F; Camacho, María; Zumbado, Manuel; Henríquez-Hernández, Luis A; Luzardo, Octavio P

    2015-05-01

    Numerous epidemiological studies have demonstrated a link between excessive meat consumption and the incidence of various cancers, especially colorectal cancer, and it has been suggested that environmental carcinogens present in meat might be related to the increased risk of cancer associated with this food. However, there are no studies evaluating the carcinogenic potential of meat in relation to its content of carcinogens. Our purpose was to emphasize the relevance of environmental carcinogens existing in meat as a determinant of the association between cancer and meat consumption. Because within Europe, Spain shows high consumption of meat and charcuterie, we performed this study focusing on Spanish population. Based on the preferences of consumers we acquired 100 samples of meat and charcuterie that reflect the variety available in the European market. We quantified in these samples the concentration of 33 chemicals with calculated carcinogenic potential (PAHs, organochlorine pesticides, and dioxin-like PCBs). The carcinogenic risk of these contaminants was assessed for each food using a risk ratio based on the current consumption of meat and charcuterie and the maximum tolerable intake of these foods depending on the level of contamination by the carcinogens they contain. Our results indicate that the current consumption of beef, pork, lamb, chicken, and "chorizo", represents a relevant carcinogenic risk for consumers (carcinogenic risk quotient between 1.33 and 13.98). In order to reduce carcinogenic risk, the study population should halve the monthly consumption of these foods, and also not to surpass the number of 5 servings of beef/pork/chicken (considered together). PMID:25659303

  6. Arsenic Is A Genotoxic Carcinogen

    Science.gov (United States)

    Arsenic is a recognized human carcinogen; however, there is controversy over whether or not it should be considered a genotoxic carcinogen. Many possible modes of action have been proposed on how arsenic induces cancer, including inhibiting DNA repair, altering methylation patter...

  7. Business model scenarios for seamless content distribution and delivery

    NARCIS (Netherlands)

    Wehn de Montalvo, U.W.C.; Ballon, P.J.P.; Sokol, J.

    2005-01-01

    This paper addresses the issue of feasible business models for seamless multimedia content distribution and delivery over mobile, wireless and fixed networks. An open, interlayer approach to content delivery networks sets the scene for a great deal of flexibility in the value network for content dis

  8. Collaboration Model for ESL and Content Teachers

    Science.gov (United States)

    Broer, Kathleen

    2013-01-01

    This study will examine strategies that ESL teachers and content teachers can use to help middle school ESL students acquire science vocabulary and meta-cognitive strategies for writing skills in non-fiction text forms. Two appendixes are included. (Contains 3 figures and 2 footnotes.)

  9. Modeling and Retrieving Images by Content.

    Science.gov (United States)

    Gudivada, Venkat N.; Raghavan, Vijay V.

    1997-01-01

    Discusses content-based image retrieval systems that effectively utilize information from image databases, and provides a taxonomy for approaches to image retrieval. Highlights include image retrieval architecture that supports query operators; conceptual issues; and two application prototypes. (100 references) (Author/LRW)

  10. Oxidative Stress in the Carcinogenicity of Chemical Carcinogens

    Directory of Open Access Journals (Sweden)

    Hideki Wanibuchi

    2013-10-01

    Full Text Available This review highlights several in vivo studies utilizing non-genotoxic and genotoxic chemical carcinogens, and the mechanisms of their high and low dose carcinogenicities with respect to formation of oxidative stress. Here, we survey the examples and discuss possible mechanisms of hormetic effects with cytochrome P450 inducers, such as phenobarbital, a-benzene hexachloride and 1,1-bis(p-chlorophenyl-2,2,2-trichloroethane. Epigenetic processes differentially can be affected by agents that impinge on oxidative DNA damage, repair, apoptosis, cell proliferation, intracellular communication and cell signaling. Non-genotoxic carcinogens may target nuclear receptors and induce post-translational modifications at the protein level, thereby impacting on the stability or activity of key regulatory proteins, including oncoproteins and tumor suppressor proteins. We further discuss role of oxidative stress focusing on the low dose carcinogenicities of several genotoxic carcinogens such as a hepatocarcinogen contained in seared fish and meat, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, arsenic and its metabolites, and the kidney carcinogen potassium bromate.

  11. Oxidative Stress in the Carcinogenicity of Chemical Carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Kakehashi, Anna; Wei, Min [Department of Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-Ku, Osaka 545-8585 (Japan); Fukushima, Shoji [Japan Bioassay Research Center, Japan Industrial Safety and Health Association, 2445 Hirasawa, Hadano, Kanagawa 257-0015 (Japan); Wanibuchi, Hideki, E-mail: wani@med.osaka-cu.ac.jp [Department of Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-Ku, Osaka 545-8585 (Japan)

    2013-10-28

    This review highlights several in vivo studies utilizing non-genotoxic and genotoxic chemical carcinogens, and the mechanisms of their high and low dose carcinogenicities with respect to formation of oxidative stress. Here, we survey the examples and discuss possible mechanisms of hormetic effects with cytochrome P{sub 450} inducers, such as phenobarbital, α-benzene hexachloride and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane. Epigenetic processes differentially can be affected by agents that impinge on oxidative DNA damage, repair, apoptosis, cell proliferation, intracellular communication and cell signaling. Non-genotoxic carcinogens may target nuclear receptors and induce post-translational modifications at the protein level, thereby impacting on the stability or activity of key regulatory proteins, including oncoproteins and tumor suppressor proteins. We further discuss role of oxidative stress focusing on the low dose carcinogenicities of several genotoxic carcinogens such as a hepatocarcinogen contained in seared fish and meat, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, arsenic and its metabolites, and the kidney carcinogen potassium bromate.

  12. Oxidative Stress in the Carcinogenicity of Chemical Carcinogens

    International Nuclear Information System (INIS)

    This review highlights several in vivo studies utilizing non-genotoxic and genotoxic chemical carcinogens, and the mechanisms of their high and low dose carcinogenicities with respect to formation of oxidative stress. Here, we survey the examples and discuss possible mechanisms of hormetic effects with cytochrome P450 inducers, such as phenobarbital, α-benzene hexachloride and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane. Epigenetic processes differentially can be affected by agents that impinge on oxidative DNA damage, repair, apoptosis, cell proliferation, intracellular communication and cell signaling. Non-genotoxic carcinogens may target nuclear receptors and induce post-translational modifications at the protein level, thereby impacting on the stability or activity of key regulatory proteins, including oncoproteins and tumor suppressor proteins. We further discuss role of oxidative stress focusing on the low dose carcinogenicities of several genotoxic carcinogens such as a hepatocarcinogen contained in seared fish and meat, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, arsenic and its metabolites, and the kidney carcinogen potassium bromate

  13. Modeling soil water content for vegetation modeling improvement

    Science.gov (United States)

    Cianfrani, Carmen; Buri, Aline; Zingg, Barbara; Vittoz, Pascal; Verrecchia, Eric; Guisan, Antoine

    2016-04-01

    Soil water content (SWC) is known to be important for plants as it affects the physiological processes regulating plant growth. Therefore, SWC controls plant distribution over the Earth surface, ranging from deserts and grassland to rain forests. Unfortunately, only a few data on SWC are available as its measurement is very time consuming and costly and needs specific laboratory tools. The scarcity of SWC measurements in geographic space makes it difficult to model and spatially project SWC over larger areas. In particular, it prevents its inclusion in plant species distribution model (SDMs) as predictor. The aims of this study were, first, to test a new methodology allowing problems of the scarcity of SWC measurements to be overpassed and second, to model and spatially project SWC in order to improve plant SDMs with the inclusion of SWC parameter. The study was developed in four steps. First, SWC was modeled by measuring it at 10 different pressures (expressed in pF and ranging from pF=0 to pF=4.2). The different pF represent different degrees of soil water availability for plants. An ensemble of bivariate models was built to overpass the problem of having only a few SWC measurements (n = 24) but several predictors to include in the model. Soil texture (clay, silt, sand), organic matter (OM), topographic variables (elevation, aspect, convexity), climatic variables (precipitation) and hydrological variables (river distance, NDWI) were used as predictors. Weighted ensemble models were built using only bivariate models with adjusted-R2 > 0.5 for each SWC at different pF. The second step consisted in running plant SDMs including modeled SWC jointly with the conventional topo-climatic variable used for plant SDMs. Third, SDMs were only run using the conventional topo-climatic variables. Finally, comparing the models obtained in the second and third steps allowed assessing the additional predictive power of SWC in plant SDMs. SWC ensemble models remained very good, with

  14. [Saccharomyces cerevisiae as a model organism for studying the carcinogenicity of non-ionizing electromagnetic fields and radiation].

    Science.gov (United States)

    Voĭchuk, S I

    2014-01-01

    Medical and biological aspects of the effects of non-ionizing electromagnetic (EM) fields and radiation on human health are the important issues that have arisen as a result of anthropogenic impact on the biosphere. Safe use of man-made sources of non-ionizing electromagnetic fields and radiation in a broad range of frequencies--static, radio-frequency and microwave--is a subject of discussions and speculations. The main problem is the lack of understanding of the mechanism(s) of reception of EMFs by living organisms. In this review we have analyzed the existing literature data regarding the effects of the electromagnetic radiation on the model eukaryotic organism--yeast Saccharomyces cerevisiae. An attempt was made to estimate the probability of induction of carcinogenesis in humans under the influence of magnetic fields and electromagnetic radiation of extremely low frequency, radio frequency and microwave ranges. PMID:24800516

  15. Substitution of carcinogenic solvent dichloromethane for the extraction of volatile compounds in a fat-free model food system.

    Science.gov (United States)

    Cayot, Nathalie; Lafarge, Céline; Bou-Maroun, Elias; Cayot, Philippe

    2016-07-22

    Dichloromethane is known as a very efficient solvent, but, as other halogenated solvents, is recognized as a hazardous product (CMR substance). The objective of the present work is to propose substitution solvent for the extraction of volatile compounds. The most important physico-chemical parameters in the choice of an appropriate extraction solvent of volatile compounds are reviewed. Various solvents are selected on this basis and on their hazard characteristics. The selected solvents, safer than dichloromethane, are compared using the extraction efficiency of volatile compounds from a model food product able to interact with volatile compounds. Volatile compounds with different hydrophobicity are used. High extraction yields were positively correlated with high boiling points and high Log Kow values of volatile compounds. Mixtures of solvents such as azeotrope propan-2-one/cyclopentane, azeotrope ethyl acetate/ethanol, and mixture ethyl acetate/ethanol (3:1, v/v) gave higher extraction yields than those obtained with dichloromethane. PMID:27320380

  16. Effects at exposure to low doses of ionising radiation. Carcinogenic effect - validity of the linear no-threshold model

    International Nuclear Information System (INIS)

    The paper considers the validity of the linear no-threshold model (LNT) for estimating the risk related to low (below 200 mSv) and very low (below 10 mSv) doses. LNT was launched in the early 60s aiming mainly at data registering and radiation protection (RP) measures, since it allows the estimation of the risk just by summing all radiation exposures regardless of the dose and dose rates. In 1965 the International Commission on Radiological Protection (ICRP) stated its position: 'As the existence of a threshold dose is unknown it has been assumed that even the smallest doses involve a proportionately small risk of induction of malignancies. Also, because of the lack of knowledge of the nature of the dose-effect relationship in the induction of malignancies in man - particularly at the dose levels which are relevant in radiological protection - the Commission sees no practical alternative, for the purposes of radiological protection, to assuming non-linear relationship between dose and effect, and that doses act cumulatively. The Commission is aware that the assumptions of no-threshold and of complete ditivity of all doses, but is satisfied that they are unlikely to lead to the underestimation of risks'. In the end of the 70s the discovery of oncogenes was interpreted as a scientific basis of this hypothesis, since only one mutation can transform a proto-oncogene into an oncogene. Meanwhile, LNT validity was questioned by many radiobiologists. The doubts were related to the scientific basis of LNT especially as regards very low doses. This debate is of great importance because the major aim of radiation protection is to estimate the risk related to doses of the order of few mSv, and these are the doses which are received in most of the medical examinations and which are comparable to values from the natural radiation background

  17. Finding transcriptomics biomarkers for in vivo identification of (non-)genotoxic carcinogens using wild-type and Xpa/p53 mutant mouse models

    NARCIS (Netherlands)

    M.J. Jonker; O. Bruning; M. van Iterson; M.M. Schaap; T.V. van der Hoeven; H. Vrieling; R.B. Beems; A. de Vries; H. van Steeg; T.M. Breit; M. Luijten

    2009-01-01

    The carcinogenic potential of chemicals and pharmaceuticals is traditionally tested in the chronic, 2 year rodent bioassay. This assay is not only time consuming, expensive and often with a limited sensitivity and specificity but it also causes major distress to the experimental animals. A major imp

  18. Business model issues in the development of digital cultural content

    OpenAIRE

    Wall, Gerry

    2003-01-01

    This paper examines business model aspects of digitizing cultural content. It is based in large part on a Study conducted by the author and his colleagues for the Department of Canadian Heritage. Based on data collected from several cultural institutions regarding their efforts to digitize content, the study found that implications for the cost side have been significant, leading to explorations of facilities and content sharing programs, formalized budgeting, the need for better copyright ex...

  19. Mode-of-Action Uncertainty for Dual-Mode Carcinogens: A Bounding Approach for Naphthalene-Induced Nasal Tumors in Rats Based on PBPK and 2-Stage Stochastic Cancer Risk Models

    Energy Technology Data Exchange (ETDEWEB)

    Bogen, K T

    2007-05-11

    A relatively simple, quantitative approach is proposed to address a specific, important gap in the appr approach recommended by the USEPA Guidelines for Cancer Risk Assessment to oach address uncertainty in carcinogenic mode of action of certain chemicals when risk is extrapolated from bioassay data. These Guidelines recognize that some chemical carcinogens may have a site-specific mode of action (MOA) that is dual, involving mutation in addition to cell-killing induced hyperplasia. Although genotoxicity may contribute to increased risk at all doses, the Guidelines imply that for dual MOA (DMOA) carcinogens, judgment be used to compare and assess results obtained using separate 'linear' (genotoxic) vs. 'nonlinear' (nongenotoxic) approaches to low low-level risk extrapolation. However, the Guidelines allow the latter approach to be used only when evidence is sufficient t to parameterize a biologically based model that reliably o extrapolates risk to low levels of concern. The Guidelines thus effectively prevent MOA uncertainty from being characterized and addressed when data are insufficient to parameterize such a model, but otherwise clearly support a DMOA. A bounding factor approach - similar to that used in reference dose procedures for classic toxicity endpoints - can address MOA uncertainty in a way that avoids explicit modeling of low low-dose risk as a function of administere administered or internal dose. Even when a 'nonlinear' toxicokinetic model cannot be fully validated, implications of DMOA uncertainty on low low-dose risk may be bounded with reasonable confidence when target tumor types happen to be extremely rare. This concept was i illustrated llustrated for a likely DMOA rodent carcinogen naphthalene, specifically to the issue of risk extrapolation from bioassay data on naphthalene naphthalene-induced nasal tumors in rats. Bioassay data, supplemental toxicokinetic data, and related physiologically based p

  20. Mode-of-Action Uncertainty for Dual-Mode Carcinogens:Lower Bounds for Naphthalene-Induced Nasal Tumors in Rats Implied byPBPK and 2-Stage Stochastic Cancer Risk Models

    Energy Technology Data Exchange (ETDEWEB)

    Bogen, K T

    2007-01-30

    As reflected in the 2005 USEPA Guidelines for Cancer Risk Assessment, some chemical carcinogens may have a site-specific mode of action (MOA) that is dual, involving mutation in addition to cell-killing induced hyperplasia. Although genotoxicity may contribute to increased risk at all doses, the Guidelines imply that for dual MOA (DMOA) carcinogens, judgment be used to compare and assess results obtained using separate ''linear'' (genotoxic) vs. ''nonlinear'' (nongenotoxic) approaches to low-level risk extrapolation. However, the Guidelines allow the latter approach to be used only when evidence is sufficient to parameterize a biologically based model that reliably extrapolates risk to low levels of concern. The Guidelines thus effectively prevent MOA uncertainty from being characterized and addressed when data are insufficient to parameterize such a model, but otherwise clearly support a DMOA. A bounding factor approach--similar to that used in reference dose procedures for classic toxicity endpoints--can address MOA uncertainty in a way that avoids explicit modeling of low-dose risk as a function of administered or internal dose. Even when a ''nonlinear'' toxicokinetic model cannot be fully validated, implications of DMOA uncertainty on low-dose risk may be bounded with reasonable confidence when target tumor types happen to be extremely rare. This concept was illustrated for the rodent carcinogen naphthalene. Bioassay data, supplemental toxicokinetic data, and related physiologically based pharmacokinetic and 2-stage stochastic carcinogenesis modeling results all clearly indicate that naphthalene is a DMOA carcinogen. Plausibility bounds on rat-tumor-type specific DMOA-related uncertainty were obtained using a 2-stage model adapted to reflect the empirical link between genotoxic and cytotoxic effects of the most potent identified genotoxic naphthalene metabolites, 1,2- and 1,4-naphthoquinone. Resulting

  1. New clues on carcinogenicity-related substructures derived from mining two large datasets of chemical compounds.

    Science.gov (United States)

    Golbamaki, Azadi; Benfenati, Emilio; Golbamaki, Nazanin; Manganaro, Alberto; Merdivan, Erinc; Roncaglioni, Alessandra; Gini, Giuseppina

    2016-04-01

    In this study, new molecular fragments associated with genotoxic and nongenotoxic carcinogens are introduced to estimate the carcinogenic potential of compounds. Two rule-based carcinogenesis models were developed with the aid of SARpy: model R (from rodents' experimental data) and model E (from human carcinogenicity data). Structural alert extraction method of SARpy uses a completely automated and unbiased manner with statistical significance. The carcinogenicity models developed in this study are collections of carcinogenic potential fragments that were extracted from two carcinogenicity databases: the ANTARES carcinogenicity dataset with information from bioassay on rats and the combination of ISSCAN and CGX datasets, which take into accounts human-based assessment. The performance of these two models was evaluated in terms of cross-validation and external validation using a 258 compound case study dataset. Combining R and H predictions and scoring a positive or negative result when both models are concordant on a prediction, increased accuracy to 72% and specificity to 79% on the external test set. The carcinogenic fragments present in the two models were compared and analyzed from the point of view of chemical class. The results of this study show that the developed rule sets will be a useful tool to identify some new structural alerts of carcinogenicity and provide effective information on the molecular structures of carcinogenic chemicals. PMID:26986491

  2. Impact and compliance: OSHA Carcinogen Policy

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, A.F. Jr.; Crowder, C.; Wisniewski, S.; Russell, T.; Senn, K.

    1980-06-26

    This document provides an examination of various aspects of the Occupational Safety and Health Administration (OSHA)Carcinogen Policy. To satisfy the dimensions of the Policy's broad, general nature, a two-fold approach was taken. Throughout, the focus is on the possible effects of the Policy's implementation, but this is first approached as it generally will effect research and compliance activities across broad industry sectors, while specific impacts on DOE are addressed separately. To overview and integrate these approaches, and to provide a quick reference for further information, an outline of information is presented. General or industry-wide applications are addressed both in the Summary and Overview of the Policy (Chapters I and II) and in the discussion of the Model Standard (Chapter V). Also included is a copy of the Policy itself in the General Industry Standards and interpretations Change 10. Sections specifically addressed to the major concerns of DOE and its contractors are a discussion of implications for action regarding the synthetic fuels program, a comparison of the OSHA Model Regulations and the FE OSH Manual Standards for Carcinogens, and finally, a list of known carcinogens in coal gasification/liquefaction. Together, these elements illustrate the broad scope of the policy's impact, which economic and other constraining consequences begin to become visible. Measures to minimize these consequences are a common underlying theme to each of the sections.

  3. Content-based network model with duplication and divergence

    Science.gov (United States)

    Şengün, Yasemin; Erzan, Ayşe

    2006-06-01

    We construct a minimal content-based realization of the duplication and divergence model of genomic networks introduced by Wagner [Proc. Natl. Acad. Sci. 91 (1994) 4387] and investigate the scaling properties of the directed degree distribution and clustering coefficient. We find that the content-based network exhibits crossover between two scaling regimes, with log-periodic oscillations for large degrees. These features are not present in the original gene duplication model, but inherent in the content-based model of Balcan and Erzan. The scaling form of the degree distribution of the content-based model turns out to be robust under duplication and divergence, with some re-adjustment of the scaling exponents, while the out-clustering coefficient goes over from a weak power-law dependence on the degree, to an exponential decay under mutations which include splitting and merging of strings.

  4. Designer Modeling for Personalized Game Content Creation Tools

    DEFF Research Database (Denmark)

    Liapis, Antonios; Yannakakis, Georgios N.; Togelius, Julian

    2013-01-01

    With the growing use of automated content creation and computer-aided design tools in game development, there is potential for enhancing the design process through personalized interactions between the software and the game developer. This paper proposes designer modeling for capturing the designer’s...... preferences, goals and processes from their interaction with a computer-aided design tool, and suggests methods and domains within game development where such a model can be applied. We describe how designer modeling could be integrated with current work on automated and mixed-initiative content creation......, and envision future directions which focus on personalizing the processes to a designer’s particular wishes....

  5. Critical analysis of carcinogenicity study outcomes. Relationship with pharmacological properties.

    Science.gov (United States)

    van der Laan, Jan Willem; Kasper, Peter; Silva Lima, Beatriz; Jones, David R; Pasanen, Markku

    2016-08-01

    Predicting the outcome of life-time carcinogenicity studies in rats based on chronic (6-month) toxicity studies in this species is possible in some instances. This should reduce the number of such studies and hence have a significant impact on the total number of animals used in safety assessment of new medicines. From a regulatory perspective, this should be sufficient to grant a waiver for a carcinogenicity study in those cases where there is confidence in the outcome of the prediction. Pharmacological properties are a frequent key factor for the carcinogenic mode of action of some pharmaceuticals, but data-analysis on a large dataset has never been formally conducted. We have conducted an analysis of a dataset based on the perspective of the pharmacology of 255 compounds from industrial and regulatory sources. It is proposed that a pharmacological, class-specific, model may consist of an overall causal relationship between the pharmacological class and the histopathology findings in rats after 6 months treatment, leading to carcinogenicity outcome after 2 years. Knowledge of the intended drug target and pathway pharmacology should enhance the prediction of either positive or negative outcomes of rat carcinogenicity studies. The goal of this analysis is to review the pharmacological properties of compounds together with the histopathology findings from the chronic toxicity study in rodents in order to introduce an integrated approach to estimate the risk of human carcinogenicity of pharmaceuticals. This approach would allow scientists to define conditions under which 2-year rat carcinogenicity studies will or will not add value to such an assessment. We have demonstrated the possibility of a regulatory waiver for a carcinogenicity study in rats, as currently discussed in the International Council for Harmonization (ICH) - formerly known as the International Conference on Harmonization (ICH), by applying the proposed prediction approach in a number of case studies

  6. Prostaglandin hydroperoxidase-catalyzed activation of certain N-substituted aryl renal and bladder carcinogens

    OpenAIRE

    Zenser, T V; Cohen, S M; Mattammal, M. B.; Wise, R. W.; Rapp, N. S.; Davis, B B

    1983-01-01

    Certain carcinogens are thought to induce renal and bladder cancer following metabolic activation. We propose a model system for this activation and provide supporting experimental evidence. This model proposes that renal and bladder carcinogens' entry into the urinary tract is facilitated, that carcinogens are activated by the prostaglandin hydroperoxidase activity of prostaglandin endoperoxide synthetase (PES), and that activation results in covalent binding to nucleic acids which can initi...

  7. Fedora Content Modelling for Improved Services for Research Databases

    DEFF Research Database (Denmark)

    Elbæk, Mikael Karstensen; Heller, Alfred; Pedersen, Gert Schmeltz

    A re-implementation of the research database of the Technical University of Denmark, DTU, is based on Fedora. The backbone consists of content models for primary and secondary entities and their relationships, giving flexible and powerful extraction capabilities for interoperability and reporting....... By adopting such an abstract data model, the platform enables new and improved services for researchers, librarians and administrators....

  8. Content Linking for UGC based on Word Embedding Model

    Directory of Open Access Journals (Sweden)

    Zhiqiao Gao

    2015-09-01

    Full Text Available There are huge amounts of User Generated Contents (UGCs consisting of authors’ articles of different themes and readers’ on-line comments on social networks every day. Generally, an article often gives rise to thousands of readers’ comments, which are related to specific points of the originally published article or previous comments. Hence it has suggested the urgent need for automated methods to implement the content linking task, which can also help other related applications, such as information retrieval, summarization and content management. So far content linking is still a relatively new issue. Because of the unsatisfactory of traditional ways based on feature extraction, we look forward to using deeper textual semantic analysis. The Word Embedding model based on deep learning has performed well in Natural Language Processing (NLP, especially in mining deep semantic information recently. Therefore, we study further on the Word Embedding model trained by different neural network models from which we can learn the structure, principles and training ways of the neural network language model in more depth to complete deep semantic feature extraction. With the aid of the semantic features, we expect to do further research on content linking between comments and their original articles from social networks, and finally verify the validity of the proposed method by comparison with traditional ways based on feature extraction.

  9. Determination of potentially carcinogenic compounds in food : trace analysis of vinylchloride, vinylidenechloride, acrylonitrile, epichlorohydrin and diethylpyrocarbonate

    NARCIS (Netherlands)

    Lierop, van J.B.H.

    1979-01-01

    Toxicological evidence shows that some monomers present in packaging materials may be carcinogenic. These monomers, notably vinylchloride, vinylidenechloride, acrylonitrile and epichlorohydrin, may migrate from the packaging material into the food. Therefore, severe limits are set to the contents of

  10. EVALUATION OF THE POTENTIAL CARCINOGENICITY OF CYCLOPHOSPHAMIDE

    Science.gov (United States)

    Cyclophosphamide is a probable human carcinogen, classified as weight-of-evidence Group B1 under the EPA Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986a).Evidence on potential carcinogenicity from animal studies is "Sufficient," and the evidence from human studies is "...

  11. Content

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    Aim, content and methods are fundamental categories of both theoretical and practical general didactics. A quick glance in recent pedagogical literature on higher education, however, reveals a strong preoccupation with methods, i.e. how teaching should be organized socially (Biggs & Tang, 2007; R...... strategy is theoretically based on systems theory as formulated by Niklas Luhmann (Luhmann, 1995; 2002) and on own work, where. Luhmann’s general ideas and concepts of the educational system are transposed into a didactical framework (Keiding, 2005,2007,2008).......Aim, content and methods are fundamental categories of both theoretical and practical general didactics. A quick glance in recent pedagogical literature on higher education, however, reveals a strong preoccupation with methods, i.e. how teaching should be organized socially (Biggs & Tang, 2007......, is subordinating content to methods as seen in modern didactics, hereby transforming content to a medium for achievement of learning-to-learn skills rather than something valuable in its own right. At the level of general didactics quite few attempts have been made to formulate criteria and...

  12. Estimation of carcinogenicity using molecular fragments tree.

    Science.gov (United States)

    Wang, Yong; Lu, Jing; Wang, Fei; Shen, Qiancheng; Zheng, Mingyue; Luo, Xiaomin; Zhu, Weiliang; Jiang, Hualiang; Chen, Kaixian

    2012-08-27

    Carcinogenicity is an important toxicological endpoint that poses high concern to drug discovery. In this study, we developed a method to extract structural alerts (SAs) and modulating factors of carcinogens on the basis of statistical analyses. First, the Gaston algorithm, a frequent subgraph mining method, was used to detect substructures that occurred at least six times. Then, a molecular fragments tree was built and pruned to select high-quality SAs. The p-value of the parent node in the tree and that of its children nodes were compared, and the nodes that had a higher statistical significance in binomial tests were retained. Finally, modulating factors that suppressed the toxic effects of SAs were extracted by three self-defining rules. The accuracy of the 77 SAs plus four SA/modulating factor pairs model for the training set, and the test set was 0.70 and 0.65, respectively. Our model has higher predictive ability than Benigni's model, especially in the test set. The results highlight that this method is preferable in terms of prediction accuracy, and the selected SAs are useful for prediction as well as interpretation. Moreover, our method is convenient to users in that it can extract SAs from a database using an automated and unbiased manner that does not rely on a priori knowledge of mechanism of action. PMID:22834690

  13. Nucleon Spin Content in a Relativistic Quark Potential Model Approach

    Institute of Scientific and Technical Information of China (English)

    DONG YuBing; FENG QingGuo

    2002-01-01

    Based on a relativistic quark model approach with an effective potential U(r) = (ac/2)(1 + γ0)r2, the spin content of the nucleon is investigated. Pseudo-scalar interaction between quarks and Goldstone bosons is employed to calculate the couplings between the Goldstone bosons and the nucleon. Different approaches to deal with the center of mass correction in the relativistic quark potential model approach are discussed.

  14. Inverse modeling of GPR signal for estimating soil water content

    Science.gov (United States)

    Lambot, S.; van den Bosch, I.; Slob, E. C.; Stockbroeckx, B.; Scheers, B.; Vanclooster, M.

    2003-04-01

    For a large variety of environmental and agricultural applications, the use of ground penetrating radar (GPR) for identifying soil water content is a matter of concern. However, the current state of technology still needs improvements and new developments. Research has focused on the development of an integrated inverse modeling approach including GPR design, GPR signal forward modeling, and GPR signal inversion to estimate simultaneously the depth dependent dielectric constant and electrical conductivity of the shallow subsurface. We propose to use as radar system a stepped frequency continuous wave radar with an ultrawide band dielectric filled TEM horn antenna used in monostatic mode. This configuration is appropriate for real time mapping and allows for a more realistic forward modeling of the radar-antenna-soil system. Forward modeling was based on the exact solution of Maxwell's equations and inversion was formulated by the classical least square problem. Given the inherent complex topography of the objective functions to optimize in electromagnetic inversion problems, we used for the inversion the recently developed global multilevel coordinate search algorithm that we combine sequentially with the local Nelder-Mead simplex algorithm. We applied the method in laboratory conditions on tank filled with sand subject to different water content levels considering a homogeneous water profile. The inverse estimation of the soil dielectric constant was remarkably well in accordance with each water content level and the corresponding theoretical values of the dielectric constant for the sand. Comparison of GPR measurements with estimations from time domain reflectometry (TDR) were also well in close agreement.

  15. CONTENTS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The Development and Evolution of the Idea of the Mandate of Heaven in the Zhou Dynasty The changes in the idea of Mandate of Heaven during the Shang and Zhou dynasties are of great significance in the course of the development of traditional Chinese culture. The quickening and awakening of the humanistic spirit was not the entire content of the Zhou idea of Mandate of Heaven. In the process of annihilating the Shang dynasty and setting up their state, the Zhou propagated the idea of the Mandate of Heaven out of practical needs. Their idea of the Mandate of Heaven was not very different from that of the Shang. From the Western Zhou on, the Zhou idea of Mandate of Heaven by no means developed in a linear way along a rational track. The intermingling of rationality and irrationality and of awakening and non-awakening remained the overall state of the Zhou intellectual superstructure after their "spiritual awakening".

  16. User Modeling Combining Access Logs, Page Content and Semantics

    CERN Document Server

    Fortuna, Blaz; Grobelnik, Marko

    2011-01-01

    The paper proposes an approach to modeling users of large Web sites based on combining different data sources: access logs and content of the accessed pages are combined with semantic information about the Web pages, the users and the accesses of the users to the Web site. The assumption is that we are dealing with a large Web site providing content to a large number of users accessing the site. The proposed approach represents each user by a set of features derived from the different data sources, where some feature values may be missing for some users. It further enables user modeling based on the provided characteristics of the targeted user subset. The approach is evaluated on real-world data where we compare performance of the automatic assignment of a user to a predefined user segment when different data sources are used to represent the users.

  17. A review of mechanisms of acrylamide carcinogenicity.

    Science.gov (United States)

    Besaratinia, Ahmad; Pfeifer, Gerd P

    2007-03-01

    The fact that acrylamide, a proven rodent carcinogen, is present in significant quantities (up to several mg/kg of foodstuff) in a wide range of commonly consumed human foods is alarming. Attempts to determine a possible involvement of dietary acrylamide in human cancers have not been conclusive, however. To resolve the carcinogenicity of acrylamide to humans, the as yet unknown mechanism of action of acrylamide needs to be unraveled. The present review is a synopsis of research on the known and hypothetical modes of action of acrylamide of relevance for carcinogenesis. Both genotoxic and non-genotoxic modes of action of acrylamide are discussed with special emphasis on DNA adduct-targeted mutagenesis. Mechanistic data are presented from various experimental systems including in vitro experiments and in vivo rodent and human studies with special focus on mouse models. Human exposure data, including estimates of daily intake of dietary acrylamide in different populations and the corresponding cancer risk assessments are provided. The significant gaps in knowledge, which currently preclude a more definitive evaluation of human cancer risk due to exposure to dietary acrylamide, are highlighted. Future directions for research on acrylamide and cancer are outlined, and potential challenges are underscored. PMID:17234719

  18. Carcinogenicity/tumour promotion by NDL PCB

    Energy Technology Data Exchange (ETDEWEB)

    Schrenk, D. [Kaiserslautern Univ. (Germany). Food Chemistry and Environmental Toxicology

    2004-09-15

    Polychlorinated biphenyls (PCBs) belong to the group of persistent environmental pollutants exhibiting neurotoxic, teratogenic and tumour-promoting effects in experimental animal models. PCB congeners can be divided into 'dioxinlike' and 'non-dioxinlike' congeners on the basis of their ability to act as aryl hydrocarbon receptor (AhR) agonists. Like the most toxic dioxin congener 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) 'dioxinlike' PCBs bind to the AhR and show characteristic effects on the expression of AhR-regulated genes including the induction of cytochrome P450 (CYP) 1A1. On the other hand, 'non-dioxinlike' PCB congeners have a lower or no binding affinity to the AhR, but exhibit a 'phenobarbital-type' induction of CYP 2B1/2 activity. A carcinogenic potential of PCBs has been demonstrated with technical mixtures such as Aroclors or Clophens. In these studies the liver and the thyroid gland were found to be the principal target organs of PCB-mediated carcinogenesis in rodents. No studies have been published, however, on the carcinogenicity of individual congeners. In two-stage initiation-promotion protocols in rats, both technical mixtures and individual 'dioxinlike' and 'non-dioxinlike' congeners were reported to act as liver tumour promoters.

  19. Flavor content of the nucleon in an unquenched quark model

    CERN Document Server

    Bijker, R

    2008-01-01

    We discuss the flavor content of the nucleon in an unquenched quark model in which the effects of quark-antiquark pairs (up, down and strange) are taken into account in an explicit form. It is shown that the inclusion of quark-antiquark pairs leads to an excess of anti-d over anti-u quarks in the proton and to a large contribution of orbital angular momentum to the spin of the proton.

  20. Serving Embedded Content via Web Applications: Model, Design and Experimentation

    OpenAIRE

    Duquennoy, Simon; Grimaud, Gilles; Vandewalle, Jean-Jacques

    2009-01-01

    Embedded systems such as smart cards or sensors are now widespread, but are often closed systems, only accessed via dedicated terminals. A new trend consists in embedding Web servers in small devices, making both access and application development easier. In this paper, we propose a TCP performance model in the context of embedded Web servers, and we introduce a taxonomy of the contents possibly served by Web applications. The main idea of this paper is to adapt the communication stack behavi...

  1. MOOCs in universities: intelligent model for delivering online learning content

    OpenAIRE

    Sammour, George; Al-Zoubi, Abdallah; Gladun, Anatoly; Khala, Katerina; Schreurs, Jeanne

    2016-01-01

    - A massive open online course (MOOC) is a model for delivering learning content online to any person who wants to take a course, with no conditions on attendance. Unlike traditional courses, MOOCs require additional skills, provided by videographers, instructional designers, IT specialists and platform specialists. Over the past few years several Universities facilitated partnership with MOOCs providers and are building MOOC courses, to serve as e-Iearning versions of...

  2. A Network Contention Model for the Extreme-scale Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Engelmann, Christian [ORNL; Naughton III, Thomas J [ORNL

    2015-01-01

    The Extreme-scale Simulator (xSim) is a performance investigation toolkit for high-performance computing (HPC) hardware/software co-design. It permits running a HPC application with millions of concurrent execution threads, while observing its performance in a simulated extreme-scale system. This paper details a newly developed network modeling feature for xSim, eliminating the shortcomings of the existing network modeling capabilities. The approach takes a different path for implementing network contention and bandwidth capacity modeling using a less synchronous and accurate enough model design. With the new network modeling feature, xSim is able to simulate on-chip and on-node networks with reasonable accuracy and overheads.

  3. A threshold model of content knowledge transfer for socioscientific argumentation

    Science.gov (United States)

    Sadler, Troy D.; Fowler, Samantha R.

    2006-11-01

    This study explores how individuals make use of scientific content knowledge for socioscientific argumentation. More specifically, this mixed-methods study investigates how learners apply genetics content knowledge as they justify claims relative to genetic engineering. Interviews are conducted with 45 participants, representing three distinct groups: high school students with variable genetics knowledge, college nonscience majors with little genetics knowledge, and college science majors with advanced genetics knowledge. During the interviews, participants advance positions concerning three scenarios dealing with gene therapy and cloning. Arguments are assessed in terms of the number of justifications offered as well as justification quality, based on a five-point rubric. Multivariate analysis of variance results indicate that college science majors outperformed the other groups in terms of justification quality and frequency. Argumentation does not differ among nonscience majors or high school students. Follow-up qualitative analyses of interview responses suggest that all three groups tend to focus on similar, sociomoral themes as they negotiate socially complex, genetic engineering issues, but that the science majors frequently reference specific science content knowledge in the justification of their claims. Results support the Threshold Model of Content Knowledge Transfer, which proposes two knowledge thresholds around which argumentation quality can reasonably be expected to increase. Research and educational implications of these findings are discussed.

  4. The in vivo rodent test systems for assessment of carcinogenic potential

    DEFF Research Database (Denmark)

    van der Laan, Jan-Willem; Spindler, Per

    2002-01-01

    mouse models, the RasH2 and Tg.AC transgenic mouse models, and the neonatal mouse model. The "ICH Guideline S1B on Testing for Carcinogenicity of Pharmaceuticals" advocates that carcinogenicity testing of pharmaceuticals, when needed, might be carried out choosing one 2-year rodent carcinogenicity study...... (rat) plus one other study that supplements the 2-year study and providing additional information that is not readily available from the 2-year study: either (1) a short- or medium-term in vivo rodent test system or (2) a 2-year carcinogenicity study in a second rodent species (mouse). Another topic of...... end of 2001. The use of the short- and medium-term rodent test systems were not considered appropriate for the assessment of carcinogenic potential of biotechnology-derived medicinal products....

  5. Contents

    Directory of Open Access Journals (Sweden)

    Editor IJRED

    2012-11-01

    Full Text Available International Journal of Renewable Energy Development www.ijred.com Volume 1             Number 3            October 2012                ISSN 2252- 4940   CONTENTS OF ARTICLES page Design and Economic Analysis of a Photovoltaic System: A Case Study 65-73 C.O.C. Oko , E.O. Diemuodeke, N.F. Omunakwe, and E. Nnamdi     Development of Formaldehyde Adsorption using Modified Activated Carbon – A Review 75-80 W.D.P Rengga , M. Sudibandriyo and M. Nasikin     Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC 81-86 A. Buasri , B. Ksapabutr, M. Panapoy and N. Chaiyut     Wind Resource Assessment in Abadan Airport in Iran 87-97 Mojtaba Nedaei       The Energy Processing by Power Electronics and its Impact on Power Quality 99-105 J. E. Rocha and B. W. D. C. Sanchez       First Aspect of Conventional Power System Assessment for High Wind Power Plants Penetration 107-113 A. Merzic , M. Music, and M. Rascic   Experimental Study on the Production of Karanja Oil Methyl Ester and Its Effect on Diesel Engine 115-122 N. Shrivastava,  , S.N. Varma and M. Pandey  

  6. Computer Modeling of Violent Intent: A Content Analysis Approach

    Energy Technology Data Exchange (ETDEWEB)

    Sanfilippo, Antonio P.; Mcgrath, Liam R.; Bell, Eric B.

    2014-01-03

    We present a computational approach to modeling the intent of a communication source representing a group or an individual to engage in violent behavior. Our aim is to identify and rank aspects of radical rhetoric that are endogenously related to violent intent to predict the potential for violence as encoded in written or spoken language. We use correlations between contentious rhetoric and the propensity for violent behavior found in documents from radical terrorist and non-terrorist groups and individuals to train and evaluate models of violent intent. We then apply these models to unseen instances of linguistic behavior to detect signs of contention that have a positive correlation with violent intent factors. Of particular interest is the application of violent intent models to social media, such as Twitter, that have proved to serve as effective channels in furthering sociopolitical change.

  7. Testing content addressable memories with physical fault models

    International Nuclear Information System (INIS)

    Content addressable memory (CAM) is widely used and its tests mostly use functional fault models. However, functional fault models cannot describe some physical faults exactly. This paper introduces physical fault models for write-only CAM. Two test algorithms which can cover 100% targeted physical faults are also proposed. The algorithm for a CAM module with N-bit match output signal needs only 2N+2L+4 comparison operations and 5N writing operations, where N is the number of words and L is the word length. The algorithm for a HIT-signal-only CAM module uses 2N+2L+5 comparison operations and 8N writing operations. Compared to previous work, the proposed algorithms can test more physical faults with a few more operations. An experiment on a test chip shows the effectiveness and efficiency of the proposed physical fault models and algorithms. (semiconductor integrated circuits)

  8. Modelling of DMNB Content for Marked Plastic Explosives

    Directory of Open Access Journals (Sweden)

    R.K. Sinha

    2007-11-01

    Full Text Available 2,3-dimethyl-2,3-dinitrobutane (DMNB has been internationally accepted as an additive forthe purpose of marking, as it has desired vapour pressure for reliable detection. It is reportedto be compatible with known explosive formulations and has a good shelf life. Explosivecompositions with DMNB as marking agent can be detected in the temperature range –20 ºC to+ 50 ºC. This paper describes modelling for quantifying activation energy for depletion of  DMNBin the marked explosives, period for definite detection of the marked explosives and optimuminitial concentration needed for the detection of DMNB content in the marked  plastic explosives.

  9. Content Modelling for Human Action Detection via Multidimensional Approach

    Directory of Open Access Journals (Sweden)

    Lili N. A.

    2009-03-01

    Full Text Available Video content analysis is an active research domain due to the availability andthe increment of audiovisual data in the digital format. There is a need toautomatically extracting video content for efficient access, understanding,browsing and retrieval of videos. To obtain the information that is of interest andto provide better entertainment, tools are needed to help users extract relevantcontent and to effectively navigate through the large amount of available videoinformation. Existing methods do not seem to attempt to model and estimate thesemantic content of the video. Detecting and interpreting human presence,actions and activities is one of the most valuable functions in this proposedframework. The general objectives of this research are to analyze and processthe audio-video streams to a robust audiovisual action recognition system byintegrating, structuring and accessing multimodal information viamultidimensional retrieval and extraction model. The proposed techniquecharacterizes the action scenes by integrating cues obtained from both the audioand video tracks. Information is combined based on visual features (motion,edge, and visual characteristics of objects, audio features and video forrecognizing action. This model uses HMM and GMM to provide a framework forfusing these features and to represent the multidimensional structure of theframework. The action-related visual cues are obtained by computing the spatiotemporaldynamic activity from the video shots and by abstracting specific visualevents. Simultaneously, the audio features are analyzed by locating and computeseveral sound effects of action events that embedded in the video. Finally, theseaudio and visual cues are combined to identify the action scenes. Compared withusing single source of either visual or audio track alone, such combined audiovisualinformation provides more reliable performance and allows us tounderstand the story content of movies in more detail. To compare the

  10. Micro-total envelope system with silicon nanowire separator for safe carcinogenic chemistry

    Science.gov (United States)

    Singh, Ajay K.; Ko, Dong-Hyeon; Vishwakarma, Niraj K.; Jang, Seungwook; Min, Kyoung-Ik; Kim, Dong-Pyo

    2016-01-01

    Exploration and expansion of the chemistries involving toxic or carcinogenic reagents are severely limited by the health hazards their presence poses. Here, we present a micro-total envelope system (μ-TES) and an automated total process for the generation of the carcinogenic reagent, its purification and its utilization for a desired synthesis that is totally enveloped from being exposed to the carcinogen. A unique microseparator is developed on the basis of SiNWs structure to replace the usual exposure-prone distillation in separating the generated reagent. Chloromethyl methyl ether chemistry is explored as a carcinogenic model in demonstrating the efficiency of the μ-TES that is fully automated so that feeding the ingredients for the generation is all it takes to produce the desired product. Syntheses taking days can be accomplished safely in minutes with excellent yields, which bodes well for elevating the carcinogenic chemistry to new unexplored dimensions. PMID:26916423

  11. Micro-total envelope system with silicon nanowire separator for safe carcinogenic chemistry.

    Science.gov (United States)

    Singh, Ajay K; Ko, Dong-Hyeon; Vishwakarma, Niraj K; Jang, Seungwook; Min, Kyoung-Ik; Kim, Dong-Pyo

    2016-01-01

    Exploration and expansion of the chemistries involving toxic or carcinogenic reagents are severely limited by the health hazards their presence poses. Here, we present a micro-total envelope system (μ-TES) and an automated total process for the generation of the carcinogenic reagent, its purification and its utilization for a desired synthesis that is totally enveloped from being exposed to the carcinogen. A unique microseparator is developed on the basis of SiNWs structure to replace the usual exposure-prone distillation in separating the generated reagent. Chloromethyl methyl ether chemistry is explored as a carcinogenic model in demonstrating the efficiency of the μ-TES that is fully automated so that feeding the ingredients for the generation is all it takes to produce the desired product. Syntheses taking days can be accomplished safely in minutes with excellent yields, which bodes well for elevating the carcinogenic chemistry to new unexplored dimensions. PMID:26916423

  12. A Local Pedestrian Mobility Model for Urban Content Sharing

    OpenAIRE

    Desta, Michael

    2013-01-01

    In opportunistic content sharing schemes such as the Floating Content Concept, a piece of content deemed to be relevant in certain geographical region (anchor zone) is made available for sharing without the support of any kind of infrastructure. Using the principles of opportunistic networking, content is stored and replicated among mobile nodes, ultimately dwelling in the anchor zone in a scrounging manner. As a best effort scheme, availability of content depends on the availability of inform...

  13. Markovian language model of the DNA and its information content

    CERN Document Server

    Srivastava, Shambhavi

    2015-01-01

    This work proposes a markovian memoryless model for the DNA that simplifies enormously the complexity of it. We encode nucleotide sequences into symbolic sequences, called words, from which we establish meaningful length of words and group of words that share symbolic similarities. Interpreting a node to represent a group of similar words and edges to represent their functional connectivity allows us to construct a network of the grammatical rules governing the appearance of group of words in the DNA. Our model allows to predict the transition between group of words in the DNA with unprecedented accuracy, and to easily calculate many informational quantities to better characterize the DNA. In addition, we reduce the DNA of known bacteria to a network of only tens of nodes, show how our model can be used to detect similar (or dissimilar) genes in different organisms, and which sequences of symbols are responsible for the most of the information content of the DNA. Therefore, the DNA can indeed be treated as a ...

  14. Statistical modelling applied to the contents of waste drums - 16085

    International Nuclear Information System (INIS)

    Gamma spectrometry is widely used to determine the radioactive content of waste drums. However, the results of such surveys often result in large numbers of limit-of-detection (LOD) results. In this paper we will show how simple statistical methods can be used to obtain useful information on the average drum activities, even in these unfavourable circumstances. Results from measurements on 60Co, 152Eu, 154Eu activities in drums of waste from decommissioning of the GLEEP reactor suggest that these activities are log-normally distributed with geometric standard deviations (GSD) ranging from 3-4. This statistical model can be used to extract information from 235U, 234mPa and 234Th datasets which show only LOD activity results. In a repository of N drums, each with activity < L, the total activity is clearly < NL. However, we can use the lognormal model to make a much stronger statement about the total waste activity. This model is developed quantitatively in the paper. (authors)

  15. ALOCOM: a generic content model for learning objects

    OpenAIRE

    Verbert, Katrien; Duval, Erik

    2008-01-01

    e-Learning organizations are focusing heavily on learning content reusability. The ultimate goal is a learning object economy characterized by searchable digital libraries of reusable learning objects that can be exchanged and reused across various learning systems. To enable such approach, basic questions of learning content interoperability need to be addressed. This paper investigates the interoperation of learning content defined according to different specifications. A number of content ...

  16. Occurrence of the carcinogenic compound ptaquiloside in the soil environment

    DEFF Research Database (Denmark)

    Rasmussen, Lars Holm; Kroghsbo, Stine; Frisvad, Jens Christian;

    2003-01-01

    Bracken (Pteridium aquilinum (L.) Kuhn) is a common fern found on all continents except Antarctica. It is under suspicion of causing cancer among people who utilizes it as food. The main carcinogenic compound is thought to be the water-soluble compound ptaquiloside. Ptaquiloside-uptake may occur....... The ptaquiloside-content in the standing biomass, which could be transferred to the soil by the end of the growing season, ranged between 10 and 260 mgm2, with nine sites having ptaquiloside loads over 100 mgm2. The carbon-content in the O-horizon, the precipitation, the amount of Bracken-litter, the...... turnover rate and the size of Bracken-stands determined the ptaquiloside-content in the soil materials while the content in fronds was found to be a function of the frond-height and the light-exposure in the ecosystem....

  17. Risk assessment of DNA-reactive carcinogens in food

    International Nuclear Information System (INIS)

    Risk assessment of DNA-reactive carcinogens in food requires knowledge of the extent of DNA damage in the target organ which results from the competition between DNA adduct formation and repair. Estimates of DNA adduct levels can be made by direct measurement or indirectly as a consequence of their presence, for example, by tumor formation in animal models or exposed populations epidemiologically. Food-borne DNA-reactive carcinogens are present from a variety of sources. They are generally not intrinsically DNA-reactive but require bioactivation to DNA-reactive metabolites a process which may be modulated by the compound itself or the presence of other xenobiotics. A single DNA reactant may form several distinct DNA adducts each undergoing different rates of repair. Some DNA reactants may be photochemically activated or produce reactive oxygen species and thus indirect oxidative DNA damage. The levels of DNA adducts arising from exposures influenced by variations in the doses, the frequency with which an individual is exposed, and rates of DNA repair for specific adducts. Each adduct has a characteristic efficiency with which it induces mutations. Based on experience with the well-studied DNA-reactive food carcinogen aflatoxin B1 (AFB1), a limit of 20 ppb or ∼30 μg/day has been set and is considered a tolerable daily intake (TDI). Since AFB1 is considered a potent carcinogen, doses of 32P-postlabeling or the use of surrogates such as hemoglobin adducts, together with approaches to evaluate the results. A discussion of approaches to estimating possible threshold effects for DNA-reactive carcinogens is made

  18. Biomonitoring of exposure to chemical carcinogens

    Czech Academy of Sciences Publication Activity Database

    Šrám, Radim

    Poland : Institute of Nuclear Physics, 2002. s. -. [NATO advanced research workshop (Human monitoring for genetic effects). 23.06.2002-27.06.2002, Krakow - Poland] Institutional research plan: CEZ:AV0Z5039906 Keywords : carcinogens Subject RIV: FH - Neurology

  19. Mutagenic and carcinogenic properties of drinking water

    International Nuclear Information System (INIS)

    In this chapter results of oxidation treatments with chlorine, ozone, chlorine dioxide, and ultraviolet (UV), with respect to their effects on activity (Ames test) in drinking water supplies are reviewed. In addition, the authors present the preliminary results of a pilot plant study on the effects of chlorine and chlorine dioxide on mutagenicity. Furthermore, results of several carcinogenicity studies performed with organic drinking water concentrates are discussed in relation to the results of a Dutch carcinogenicity study with mutagenic drinking water concentrates

  20. The role of pancreatic islets in experimental pancreatic carcinogenicity.

    OpenAIRE

    ISHIKAWA, O; Ohigashi, H.; Imaoka, S.; Nakai, I.; Mitsuo, M.; Weide, L. van der; Pour, P. M.

    1995-01-01

    Our previous studies have suggested that the presence of intact islets is essential for the induction of pancreatic exocrine tumors in the Syrian hamster model. To validate this, we investigated the effect of the carcinogen, N-nitrosobis(2-oxo-propyl)amine (BOP) in hamsters, in which homologous isolated intact islets were transplanted into the submandibular gland (SMG). Freshly isolated pure islets from hamster donors were transplanted into the left SMG of 20 female host hamsters. Ten of thes...

  1. Enhanced replication of UV-damaged Simian virus 40 DNA in carcinogen-treated mammalian cells

    International Nuclear Information System (INIS)

    The replication of UV-damaged Simian virus 40 (SV40) in carcinogen-treated monkey cells has been studied to elucidate the mechanism of carcinogen-enhanced reactivation. Carcinogen enhanced reactivation is the observed increase in UV-irradiated virus survival in host cells treated with low doses of carcinogen compared to UV-irradiated virus survival in untreated hosts. Carcinogen treatment of monkey kidney cells with either N-acetoxy-2-acetylaminofluorene (AAAF) or UV radiation leads to an enhanced capacity to replicate UV-damaged virus during the first round of infection. To further define the mechanism leading to enhanced replication, a detailed biochemical analysis of replication intermediates in carcinogen-treated cells was performed. Several conclusions can be drawn. First enhanced replication can be observed in the first four rounds of replication after UV irradiation of viral templates. The second major finding is that the relaxed circular intermediate model proposed for the replication of UV-damaged templates in untreated cells appears valid for replication of UV-damaged templates in carcinogen-treated cells. Possible mechanisms and the supporting evidence are discussed and future experiments outlined

  2. Modelling unfrozen water content in a silty clay permafrost deposit

    DEFF Research Database (Denmark)

    Agergaard, Frederik Ancker; Ingeman-Nielsen, Thomas

    2011-01-01

    permafrost core of material properties similar to the test soil. The calibration for 5°C is seen to make a good fit to the permafrost core data. Further experiments should be performed in order to extend the range of water contents tested and hence the range of validity of the calibration equation.......The mechanical properties of both unfrozen soils and permafrost soils are influenced by the amount of unfrozen water in the pore space. When dealing with foundation engineering in permafrost areas it is essential to estimate the unfrozen water content (wu). This paper deals with the establishing of...... a calibration equation for determining the unfrozen water content of a Greenlandic silty clay permafrost deposit. Calibration experiments have been conducted for water contents in the interval 0 – 10 % at both 5 °C and 22 °C. Calibration equations are verified against permittivity data from a...

  3. Content Linking for UGC based on Word Embedding Model

    OpenAIRE

    Zhiqiao Gao; Lei Li; Liyuan Mao; Dezhu He; Chao Xue

    2015-01-01

    There are huge amounts of User Generated Contents (UGCs) consisting of authors’ articles of different themes and readers’ on-line comments on social networks every day. Generally, an article often gives rise to thousands of readers’ comments, which are related to specific points of the originally published article or previous comments. Hence it has suggested the urgent need for automated methods to implement the content linking task, which can also help other related applications, such as inf...

  4. The multitude and diversity of environmental carcinogens

    International Nuclear Information System (INIS)

    We have recently proposed that lifestyle-related factors, screening and aging cannot fully account for the present overall growing incidence of cancer. In order to propose the concept that in addition to lifestyle related factors, exogenous environmental factors may play a more important role in carcinogenesis than it is expected, and may therefore account for the growing incidence of cancer, we overview herein environmental factors, rated as certainly or potentially carcinogenic by the International Agency for Research on Cancer (IARC). We thus analyze the carcinogenic effect of microorganisms (including viruses), radiations (including radioactivity, UV and pulsed electromagnetic fields) and xenochemicals. Chemicals related to environmental pollution appear to be of critical importance, since they can induce occupational cancers as well as other cancers. Of major concerns are: outdoor air pollution by carbon particles associated with polycyclic aromatic hydrocarbons; indoor air pollution by environmental tobacco smoke, formaldehyde and volatile organic compounds such as benzene and 1,3 butadiene, which may particularly affect children, and food pollution by food additives and by carcinogenic contaminants such as nitrates, pesticides, dioxins and other organochlorines. In addition, carcinogenic metals and metalloids, pharmaceutical medicines and cosmetics may be involved. Although the risk fraction attributable to environmental factors is still unknown, this long list of carcinogenic and especially mutagenic factors supports our working hypothesis according to which numerous cancers may in fact be caused by the recent modification of our environment

  5. Carcinogenicity prediction of noncongeneric chemicals by augmented top priority fragment classification.

    Science.gov (United States)

    Casalegno, Mosè; Sello, Guido

    2016-04-01

    Carcinogenicity prediction is an important process that can be performed to cut down experimental costs and save animal lives. The current reliability of the results is however disputed. Here, a blind exercise in carcinogenicity category assessment is performed using augmented top priority fragment classification. The procedure analyses the applicability domain of the dataset, allocates in clusters the compounds using a leading molecular fragment, and a similarity measure. The exercise is applied to three compound datasets derived from the Lois Gold Carcinogenic Database. The results, showing good agreement with experimental data, are compared with published ones. A final discussion on our viewpoint on the possibilities that the carcinogenicity modelling of chemical compounds offers is presented. PMID:26878128

  6. The ISS Carcinogens Data Bank (BDC)

    International Nuclear Information System (INIS)

    The Data Bank on Carcinogens (Banca Dati Cancerogeni, BDC) is a factual data bank, available on the Istituto Superiore di Sanita web site, aimed at supporting the risk management decision making of central and local administrators. It can also represent a valuable tool for industry. The available information on carcinogenicity evaluations/classifications produced by European Union and by other institutions (IARC, USEPA, NTP, CCTN) is presented in a concise form accompanied by bibliographic references enabling the users to consult the original sources and, in some cases, to be directly connected to the relevant web site. The classifications carried out by each organization in accordance with its own criteria assign the examined agents to specific qualitative categories and do not include quantitative assessment. BDC intends to provide an easy tool for experts, researchers and risk managers dealing with carcinogenic agents

  7. Teaching Concepts of Natural Sciences to Foreigners through Content-Based Instruction: The Adjunct Model

    Science.gov (United States)

    Satilmis, Yilmaz; Yakup, Doganay; Selim, Guvercin; Aybarsha, Islam

    2015-01-01

    This study investigates three models of content-based instruction in teaching concepts and terms of natural sciences in order to increase the efficiency of teaching these kinds of concepts in realization and to prove that the content-based instruction is a teaching strategy that helps students understand concepts of natural sciences. Content-based…

  8. An integrated modeling method for prediction of sulfur content in agglomerate

    Institute of Scientific and Technical Information of China (English)

    陈晓方; 桂卫华; 王雅琳; 吴敏

    2003-01-01

    Based on the idea of fusing modeling, an integrated prediction model for sintering process was proposed.A framework for sulfur content prediction was established, which integrated multi modeling ways together, including mathematical model combined with neural network(NN), rule model based on empirical knowledge and modelchoosing coordinator. Via metallurgic mechanism analysis and material balance computation, a mathematical model calculated the sulfur content in agglomerate by the material balance equation with some parameters predicted by NN method. In the other model, the relationship between sulfur content and key factors was described in the form of expert rules. The model-choosing coordinator based on fuzzy logic was introduced to decide the weight of result of each model according to process conditions. The model was tested by industrial application data and produced a relatively satisfactory prediction error. The model also preferably reflected the varying tendency of sulfur content in agglomerate as the evidence of its prediction performance.

  9. Predicting carcinogenicity of organic compounds based on CPDB.

    Science.gov (United States)

    Wu, Xiuchao; Zhang, Qingzhu; Wang, Hui; Hu, Jingtian

    2015-11-01

    Cancer is a major killer of human health and predictions for the carcinogenicity of chemicals are of great importance. In this article, predictive models for the carcinogenicity of organic compounds using QSAR methods for rats and mice were developed based on the data from CPDB. The models was developed based on the data of specific target site liver and classified according to sex of rats and mice. Meanwhile, models were also classified according to whether there is a ring in the molecular structure in order to reduce the diversity of molecular structure. Therefore, eight local models were developed in the final. Taking into account the complexity of carcinogenesis and in order to obtain as much information, DRAGON descriptors were selected as the variables used to develop models. Fitting ability, robustness and predictive power of the models were assessed according to the OECD principles. The external predictive coefficients for validation sets of each model were in the range of 0.711-0.906, and for the whole data in each model were all greater than 0.8, which represents that all models have good predictivity. In order to study the mechanism of carcinogenesis, standardized regression coefficients were calculated for all predictor variables. In addition, the effect of animal sex on carcinogenesis was compared and a trend that female showed stronger tolerance for cancerogen than male in both species was appeared. PMID:26070146

  10. A Digital Right Management Model for Distribution of Digital Audiovisual Content

    Institute of Scientific and Technical Information of China (English)

    FAN Kefeng; PEI Qingqi; WANG Meihua; MO Wei; CAO Ling

    2006-01-01

    This paper presents a digital rights management model, which considers the integrated factors including legality, communication security, integrity of the content, and trading fairness. The architecture of the model, the necessary protocol for the copyright control and content distribution, the authentication mechanism which offer consumption registration for content fair distribution, of the model are all provided. The scheme also provides distribution and evidence for using the copyright of digital content fairly and effectively. Finally, analysis shows the proposed model has both high security and good performance.

  11. Integrating content and language in English language teaching in secondary education: Models, benefits, and challenges

    OpenAIRE

    Banegas, Darío Luis

    2012-01-01

    In the last decade, there has been a major interest in content-based instruction (CBI) and content and language integrated learning (CLIL). These are similar approaches which integrate content and foreign/second language learning through various methodologies and models as a result of different implementations around the world. In this paper, I first offer a sociocultural view of CBI-CLIL. Secondly, I define language and content as vital components in CBI-CLIL. Thirdly, I revie...

  12. Colorado Model Content Standards for Music: Suggested Grade Level Expectations.

    Science.gov (United States)

    Colorado State Dept. of Education, Denver.

    The state of Colorado has set forth five content standards for music education in its public schools: (1) students sing or play on instruments a varied repertoire of music, alone or with others; (2) students will read and notate music; (3) students will create music; (4) students will listen to, analyze, evaluate, and describe music; and (5)…

  13. Maintenance Personnel Performance Simulation (MAPPS) model: description of model content, structure, and sensitivity testing. Volume 2

    International Nuclear Information System (INIS)

    This volume of NUREG/CR-3626 presents details of the content, structure, and sensitivity testing of the Maintenance Personnel Performance Simulation (MAPPS) model that was described in summary in volume one of this report. The MAPPS model is a generalized stochastic computer simulation model developed to simulate the performance of maintenance personnel in nuclear power plants. The MAPPS model considers workplace, maintenance technician, motivation, human factors, and task oriented variables to yield predictive information about the effects of these variables on successful maintenance task performance. All major model variables are discussed in detail and their implementation and interactive effects are outlined. The model was examined for disqualifying defects from a number of viewpoints, including sensitivity testing. This examination led to the identification of some minor recalibration efforts which were carried out. These positive results indicate that MAPPS is ready for initial and controlled applications which are in conformity with its purposes

  14. Carcinogenicity assessments of biotechnology-derived pharmaceuticals: a review of approved molecules and best practice recommendations.

    Science.gov (United States)

    Vahle, John L; Finch, Gregory L; Heidel, Shawn M; Hovland, David N; Ivens, Inge; Parker, Suezanne; Ponce, Rafael A; Sachs, Clifford; Steigerwalt, Ronald; Short, Brian; Todd, Marque D

    2010-06-01

    An important safety consideration for developing new therapeutics is assessing the potential that the therapy will increase the risk of cancer. For biotherapeutics, traditional two-year rodent bioassays are often not scientifically applicable or feasible. This paper is a collaborative effort of industry toxicologists to review past and current practice regarding carcinogenicity assessments of biotherapeutics and to provide recommendations. Publicly available information on eighty marketed protein biotherapeutics was reviewed. In this review, no assessments related to carcinogenicity or tumor growth promotion were identified for fifty-one of the eighty molecules. For the twenty-nine biotherapeutics in which assessments related to carcinogenicity were identified, various experimental approaches were employed. This review also discusses several key principles to aid in the assessment of carcinogenic potential, including (1) careful consideration of mechanism of action to identify theoretical risks, (2) careful investigation of existing data for indications of proliferative or immunosuppressive potential, and (3) characterization of any proliferative or immunosuppressive signals detected. Traditional two-year carcinogenicity assays should not be considered as the default method for assessing the carcinogenicity potential of biotherapeutics. If experimentation is considered warranted, it should be hypothesis driven and may include a variety of experimental models. Ultimately, it is important that preclinical data provide useful guidance in product labeling. PMID:20472697

  15. Predictive modeling of trust to social media content

    OpenAIRE

    Daniel, Samuel

    2014-01-01

    In recent years, social networking sites have got a massive popularity because they let people to devise a public profile within a tied system. As the popularity increases and they became widely used as one of the important sources of news, people become more cautious about determining the trustworthiness of the information which is disseminating through social media for various reasons. For this reason, knowing the factors that influence the trust in social media content became very importan...

  16. Mechanisms of cellular transformation by carcinogenic agents

    International Nuclear Information System (INIS)

    This book contains 14 chapters. Some of the chapter titles are: DNA Modification by Chemical Carcinogens; Role of DNA Lesions and Repair in the Transformation of Human Cells; The Induction and Regulation of Radiogenic Transformation In Vitro: Cellular and Molecular Mechanisms; Cellular Transformation by Adenoviruses; and The fos Gene

  17. Biomonitoring human exposure to environmental carcinogenic chemicals

    DEFF Research Database (Denmark)

    Farmer, P.B.; Sepai, O.; Lawrence, R.;

    1996-01-01

    detecting carcinogen-induced damage to DNA and proteins, and subsequent biological effects. These methods were validated with the occupational exposures, which showed evidence of DNA and/or protein and/or chromosome damage in workers in a coke oven plant, garage workers exposed to diesel exhaust and workers...

  18. Mechanisms of cellular transformation by carcinogenic agents

    Energy Technology Data Exchange (ETDEWEB)

    Grunberger, D.; Goff, S.P.

    1987-01-01

    This book contains 14 chapters. Some of the chapter titles are: DNA Modification by Chemical Carcinogens; Role of DNA Lesions and Repair in the Transformation of Human Cells; The Induction and Regulation of Radiogenic Transformation In Vitro: Cellular and Molecular Mechanisms; Cellular Transformation by Adenoviruses; and The fos Gene.

  19. Carcinogenic effects of radiation-introduction

    International Nuclear Information System (INIS)

    The weight of experimental evidence reviewed indicates that UV damage to DNA, probably pyrimidine dimers, is the best molecular candidate for the initiating damage that leads to skin cancer. It is postulated that the carcinogenic action spectrum should be similar to the DNA action spectrum filtered through the upper layer of skin

  20. Urban air pollution by carcinogenic and genotoxic polyaromatic hydrocarbons in the former USSR.

    OpenAIRE

    Khesina AYa,

    1994-01-01

    The content of major carcinogenic and genotoxic polyaromatic hydrocarbons (PAH) in urban air, vehicle, and industrial emissions is assessed. A sensitive, specific, and selective method for PAH and nitro-PAH quantitation was developed on the basis of low-temperature luminescence-spectra of frozen polycrystalline solutions. Polyarene contents in urban air and urban industrial emissions, as well as vehicle exhausts, are compared to the Russian Ministry of Health standard of maximal permissible c...

  1. School Board Improvement Plans in Relation to the AIP Model of Educational Accountability: A Content Analysis

    Science.gov (United States)

    van Barneveld, Christina; Stienstra, Wendy; Stewart, Sandra

    2006-01-01

    For this study we analyzed the content of school board improvement plans in relation to the Achievement-Indicators-Policy (AIP) model of educational accountability (Nagy, Demeris, & van Barneveld, 2000). We identified areas of congruence and incongruence between the plans and the model. Results suggested that the content of the improvement plans,…

  2. Carcinogens formed when Meat is Cooked

    Energy Technology Data Exchange (ETDEWEB)

    Felton, J S; Salmon, C P; Knize, M G

    2003-05-30

    Diet has been associated with varying cancer rates in human populations for many years, yet the causes of the observed variation in cancer patterns have not been adequately explained (Wynder et al. 1977). Along with the effect of diet on human cancer incidence is the strong evidence that mutations are the initiating events in the cancer process (Vogelstein et al. 1992). Foods, when heated, are a good source of genotoxic carcinogens that very likely are a cause for some of these events(Doll et al. 1981). These carcinogens fall into two chemical classes: heterocyclic aromatic amines (HAA) and polycyclic aromatic hydrocarbons (PAH). There is ample evidence that many of these compounds are complete carcinogens in rodents(El-Bayoumy et al. 1995; Ohgaki et al. 1991). Heterocyclic aromatic amines are among the most potent mutagenic substances ever tested in the Ames/Salmonella mutagenicity test (Wakabayashi et al. 1992). Both classes of carcinogen cause tumors in rodents at multiple sites, (El-Bayoumy et al. 1995; Ohgaki et al. 1991) many of which are common tumor sites in people on a Western diet. An HAA, PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine), and a PAH, B[a]P (benzo[a]pyrene), of comparable carcinogenic potency caused mammary gland tumors in a feeding study in female rats (El-Bayoumy et al. 1995). In addition, PhIP has recently been shown to cause carcinomas in the prostate of the male rat (Shirai et al. 1997). Complementing the rodent cancer studies are numerous human case-control and prospective studies suggesting a relationship between overheated beef, chicken, and lamb, and cancer of the colon, breast, prostate, and stomach (Sinha et al. 1999; Ward et al. 1997; Zheng et al. 1998).

  3. The Viscoelasticity Model of Corn Straw under the Different Moisture Contents

    OpenAIRE

    Cai Guo-Lin; Lu Li-Xin; Yu Qiu-Sheng; Cai He-Ping; Jiang Huan-Xin; Sun Zhong-Zhen; Wang Li

    2013-01-01

    Viscoelastic model of corn straw, based on different moisture contents, is set up to characterise the deformation through three-point bending test. The model contains a linear elastic element, a damping element, and a nonlinear elastic element. The parameters of the model are determined according to the features of three-point bending test curve and characteristic of the model. The relationships between mechanical properties, energy absorption behavior of corn stalk, and moisture content have...

  4. Predictions for the outcome of rodent carcinogenicity bioassays: identification of trans-species carcinogens and noncarcinogens.

    OpenAIRE

    Tennant, R W; Spalding, J.

    1996-01-01

    Thirty chemicals or substances currently undergoing long-term carcinogenicity bioassays in rodents have been used in a project to further evaluate methods and information that may have the capability of predicting potential carcinogens. In our predictions the principal information used includes structural alerts and in vitro test results for Salmonella mutagenicity, relative subchronic toxicity, and the sites and types of pathology found in subchronic (90-day) studies. This group of chemicals...

  5. Adapting models of visual aesthetics for personalized content creation

    DEFF Research Database (Denmark)

    Liapis, Antonios; Yannakakis, Georgios N.; Togelius, Julian

    2012-01-01

    ) the content itself is optimized based on the personalized evaluation function. To test the efficacy of the approach we design fitness functions based on universal properties of visual perception, inspired by psychological and neurobiological research. Using these visual properties we generate...... aesthetically pleasing 2D game spaceships via neuroevolutionary constrained optimization and evaluate the impact of the designed visual properties on the generated spaceships. The offline generated spaceships are used as the initial population of an interactive evolution experiment in which players are asked to...

  6. Analytical solution of a stochastic content-based network model

    International Nuclear Information System (INIS)

    We define and completely solve a content-based directed network whose nodes consist of random words and an adjacency rule involving perfect or approximate matches for an alphabet with an arbitrary number of letters. The analytic expression for the out-degree distribution shows a crossover from a leading power law behaviour to a log-periodic regime bounded by a different power law decay. The leading exponents in the two regions have a weak dependence on the mean word length, and an even weaker dependence on the alphabet size. The in-degree distribution, on the other hand, is much narrower and does not show any scaling behaviour

  7. Multicomponent criteria for predicting carcinogenicity: dataset of 30 NTP chemicals.

    OpenAIRE

    Huff, J; Weisburger, E; Fung, V A

    1996-01-01

    This article is in response to the challenge issued to the scientific community by the National Toxicology Program to predict the carcinogenicity potential of 30 chemicals previously selected for long-term carcinogenicity testing. Utilizing the available toxicologic, genetic, and structural information on 30 chemicals previously selected for long-term carcinogenicity testing, we predict that 16 chemicals (53%) would induce some indication of carcinogenic activity in rodents; we further predic...

  8. EVALUATION OF THE POTENTIAL CARCINOGENICITY OF COKE OVEN EMISSIONS

    Science.gov (United States)

    Coke oven emissions are known human carcinogens, classified as weight-of-evidence Group A under the EPA Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986a). vidence on potential carcinogenicity from animal studies is "Sufficient,". and the evidence rom human studies is "S...

  9. EVALUATION OF THE POTENTIAL CARCINOGENICITY OF TRYPAN BLUE

    Science.gov (United States)

    Trypan blue is a probable human carcinogen, classified as weight-of-evidence Group B2 under the EPA Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986a). vidence on potential carcinogenicity from animal studies is "Sufficient," and the evidence from human studies is "No Da...

  10. The TiN Content Computer Prediction Based on ANN and AR Model

    OpenAIRE

    Ma Chunyang; Ding Junjie; Ning Yumei; Chu Dianqing

    2013-01-01

    Artificial Neural Network (ANN) and autoregressive model (AR model) of nano TiN particles content in Ni-TiN composite coating was established by the method of time series analysis. In this paper, we want to seek for the TiN content computer prediction in Ni-TiN composite coatings by using ANN and AR model. The trend of the nano TiN particles content variation was forecasted with the AR model, and the prediction value and experimental test results were compared. The XRD patterns were investiga...

  11. Cyberbullying behavior and adolescents' use of media with antisocial content: a cyclic process model.

    Science.gov (United States)

    den Hamer, Anouk; Konijn, Elly A; Keijer, Micha G

    2014-02-01

    The present study examined the role of media use in adolescents' cyberbullying behavior. Following previous research, we propose a Cyclic Process Model of face-to-face victimization and cyberbullying through two mediating processes of anger/frustration and antisocial media content. This model was tested utilizing a cross-sectional design with adolescent participants (N=892). Exposure to antisocial media content was measured with a newly developed content-based scale (i.e., the C-ME), showing good psychometric qualities. Results of structural equation modeling showed that adolescents' exposure to antisocial media content was significantly associated with cyberbullying behavior, especially in adolescents who experienced anger and frustration due to face-to-face victimization. Goodness of fit indices demonstrated a good fit of the theoretical model to the data and indicated that exposure to antisocial media content acts as an amplifier in a cyclic process of victimization-related anger and cyberbullying behavior. PMID:24015985

  12. Detection of genotoxic and non-genotoxic carcinogens in Xpc−/−p53+/− mice

    International Nuclear Information System (INIS)

    An accurate assessment of the carcinogenic potential of chemicals and pharmaceutical drugs is essential to protect humans and the environment. Therefore, substances are extensively tested before they are marketed to the public. Currently, the rodent two-year bioassay is still routinely used to assess the carcinogenic potential of substances. However, over time it has become clear that this assay yields false positive results and also has several economic and ethical drawbacks including the use of large numbers of animals, the long duration, and the high cost. The need for a suitable alternative assay is therefore high. Previously, we have proposed the Xpa*p53 mouse model as a very suitable alternative to the two-year bioassay. We now show that the Xpc*p53 mouse model preserves all the beneficial traits of the Xpa*p53 model for sub-chronic carcinogen identification and can identify both genotoxic and non-genotoxic carcinogens. Moreover, Xpc*p53 mice appear to be more responsive than Xpa*p53 mice towards several genotoxic and non-genotoxic carcinogens. Furthermore, Xpc*p53 mice are far less sensitive than Xpa*p53 mice for the toxic activity of DNA damaging agents and as such clearly respond in a similar way as wild type mice do. These advantageous traits of the Xpc*p53 model make it a better alternative for in vivo carcinogen testing than Xpa*p53. This pilot study suggests that Xpc*p53 mice are suited for routine sub-chronic testing of both genotoxic and non-genotoxic carcinogens and as such represent a suitable alternative to possibly replace the murine life time cancer bioassay. Highlights: ► The Xpc*p53 mouse model is able to identify genotoxic and non-genotoxic carcinogens. ► Time, animals and cost can be significantly reduced compared to the 2-year bioassay. ► Xpc*p53 mice are more advantageous for carcinogen identification than Xpa*p53 mice. ► Xpc*p53 mice exhibit a wild type response upon exposure to genotoxicants.

  13. Communicative Competence: A Pedagogically Motivated Model with Content Specifications

    OpenAIRE

    Celce-Murcia, Marianne; Dornyei, Zoltan; Thurrell, Sarah

    1995-01-01

    This paper argues the need for an updated and explicit description of language teaching areas generated with reference to a detailed model of communicative competence. We describe two existing models of communicative competence and then propose our own pedagogically motivated construct, which includes five components: (1) discourse competence, (2) linguistic competence, (3) actional competence, (4) sociocultural competence, and (5) strategic competence. We discuss these competencies in as muc...

  14. Place prioritization for biodiversity content using species ecological niche modeling

    OpenAIRE

    Víctor Sánchez-Cordero; Verónica Cirelli; Mariana Munguial; Sahotra Sarkar

    2005-01-01

    Place prioritization for biodiversity representation is essential for conservation planning, particularly in megadiverse countries where high deforestation threatens biodiversity. Given the collecting biases and uneven sampling of biological inventories, there is a need to develop robust models of species’ distributions. By modeling species’ ecological niches using point occurrence data and digitized environmental feature maps, we can predict potential and extant distributions of species in u...

  15. Combining the Missing Link: An Incremental Topic Model of Document Content and Hyperlink

    OpenAIRE

    Ma, Huifang; Li, Zhixin; Shi, Zhongzhi

    2010-01-01

    The content and structure of linked information such as sets of web pages or research paper archives are dynamic and keep on changing. Even though different methods are proposed to exploit both the link structure and the content information, no existing approach can effectively deal with this evolution. We propose a novel joint model, called Link-IPLSI, to combine texts and links in a topic modeling framework incrementally. The model takes advantage of a novel link updating technique that can...

  16. Current investigations into the genotoxicity of zinc oxide and silica nanoparticles in mammalian models in vitro and in vivo: carcinogenic/genotoxic potential, relevant mechanisms and biomarkers, artifacts, and limitations

    Directory of Open Access Journals (Sweden)

    Kwon JY

    2014-12-01

    Full Text Available Jee Young Kwon,1,* Preeyaporn Koedrith,2,* Young Rok Seo1 1Department of Life Science, Institute of Environmental Medicine, Dongguk University, Seoul, Republic of Korea; 2Faculty of Environment and Resource Studies, Mahidol University, Phuttamonthon District, NakhonPathom, Thailand *These authors contributed equally to this work and should be considered as co-first authors Abstract: Engineered nanoparticles (NPs are widely used in many sectors, such as food, medicine, military, and sport, but their unique characteristics may cause deleterious health effects. Close attention is being paid to metal NP genotoxicity; however, NP genotoxic/carcinogenic effects and the underlying mechanisms remain to be elucidated. In this review, we address some metal and metal oxide NPs of interest and current genotoxicity tests in vitro and in vivo. Metal NPs can cause DNA damage such as chromosomal aberrations, DNA strand breaks, oxidative DNA damage, and mutations. We also discuss several parameters that may affect genotoxic response, including physicochemical properties, widely used assays/end point tests, and experimental conditions. Although potential biomarkers of nanogenotoxicity or carcinogenicity are suggested, inconsistent findings in the literature render results inconclusive due to a variety of factors. Advantages and limitations related to different methods for investigating genotoxicity are described, and future directions and recommendations for better understanding genotoxic potential are addressed. Keywords: carcinogenicity, exposure assessment, genotoxicity, nanoparticles, risk evaluation

  17. A Model of Adolescents’ Seeking of Sexual Content in their Media Choices

    OpenAIRE

    Bleakley, Amy; Hennessy, Michael; Fishbein, Martin

    2011-01-01

    This paper reports on the extent to which adolescents report actively seeking sexual content in media, identifies from which media they report seeking, estimates the association between seeking sexual information and romantic and sexual behavior, and shows that active seeking of sexual content in media sources is explained by an intention to seek such content using the Integrative Model of Behavioral Prediction, a reasoned action approach. The data are a national sample of 810 adolescents age...

  18. Branded Content: A new Model for driving Tourism via Film and Branding Strategies

    OpenAIRE

    Horrigan, David

    2009-01-01

    Branded content is described as a fusion of advertising and entertainment into one marketing communications product that is integrated into an organisation’s overall brand strategy intended to be distributed as entertainment content with a highly branded quality. A history of product placement, branded entertainment, and film tourism is presented to identify the effective elements of each strategy in order to inform a more cohesive brand strategy for destinations. A branded content model is...

  19. Comparison of the expression profiles induced by genotoxic and nongenotoxic carcinogens in rat liver

    International Nuclear Information System (INIS)

    Application of recently developed gene expression techniques using microarrays in toxicological studies (toxicogenomics) facilitate the interpretation of a toxic compound's mode of action and may also allow the prediction of selected toxic effects based on gene expression changes. In order to test this hypothesis, we investigated whether carcinogens at doses known to induce liver tumors in the 2-year rat bioassay deregulate characteristic sets of genes in a short term in vivo study and whether these deregulated genes represent defined biological pathways. Male Wistar rats were dosed with the four nongenotoxic hepatocarcinogens methapyrilene (MPy, 60 mg/kg/day), diethylstilbestrol (DES, 10 mg/kg/day), Wy-14643 (Wy, 60 mg/kg/day), and piperonylbutoxide (PBO, 1200 mg/kg/day). After 1, 3, 7, and 14 days, the livers were taken for histopathological evaluation and for analysis of the gene expression profiles on Affymetrix RGU34A arrays. The expression profile of the four nongenotoxic carcinogens were compared to the profiles of the four genotoxic carcinogens 2-nitrofluorene (2-NF), dimethylnitrosamine (DMN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and aflatoxin B1 (AB1) from a similar study reported previously. By using statistical and clustering tools characteristically deregulated genes were extracted and functionally classified. Distinct cellular pathways were affected by the nongenotoxic carcinogens compared to the genotoxic carcinogens which at least partly correlated with the two-stage model of carcinogenesis. Characteristic to genotoxic carcinogens were a DNA damage response and the activation of proliferative and survival signaling. Nongenotoxic carcinogens showed responses to oxidative DNA or protein damage, as well as cell cycle progression and signs of regeneration. Many of the gene alterations found with the nongenotoxic carcinogens imply compound-specific mechanisms. Although neither a single gene nor a single pathway will be sufficient to

  20. Comparison of the expression profiles induced by genotoxic and nongenotoxic carcinogens in rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Ellinger-Ziegelbauer, Heidrun [Bayer Healthcare AG, Department of Molecular and Genetic Toxicology, Aprather Weg 18a, 42096 Wuppertal (Germany)]. E-mail: heidrun.ellinger-ziegelbauer@bayerhealthcare.com; Stuart, Barry [Bayer Crop Science, Department of Toxicology, Stilwell, KS (United States); Wahle, Brad [Bayer Crop Science, Department of Toxicology, Stilwell, KS (United States); Bomann, Werner [Bayer Crop Science, Department of Toxicology, Stilwell, KS (United States); Ahr, Hans Juergen [Bayer Healthcare AG, Department of Molecular and Genetic Toxicology, Aprather Weg 18a, 42096 Wuppertal (Germany)

    2005-08-04

    Application of recently developed gene expression techniques using microarrays in toxicological studies (toxicogenomics) facilitate the interpretation of a toxic compound's mode of action and may also allow the prediction of selected toxic effects based on gene expression changes. In order to test this hypothesis, we investigated whether carcinogens at doses known to induce liver tumors in the 2-year rat bioassay deregulate characteristic sets of genes in a short term in vivo study and whether these deregulated genes represent defined biological pathways. Male Wistar rats were dosed with the four nongenotoxic hepatocarcinogens methapyrilene (MPy, 60 mg/kg/day), diethylstilbestrol (DES, 10 mg/kg/day), Wy-14643 (Wy, 60 mg/kg/day), and piperonylbutoxide (PBO, 1200 mg/kg/day). After 1, 3, 7, and 14 days, the livers were taken for histopathological evaluation and for analysis of the gene expression profiles on Affymetrix RG{sub U}34A arrays. The expression profile of the four nongenotoxic carcinogens were compared to the profiles of the four genotoxic carcinogens 2-nitrofluorene (2-NF), dimethylnitrosamine (DMN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and aflatoxin B1 (AB1) from a similar study reported previously. By using statistical and clustering tools characteristically deregulated genes were extracted and functionally classified. Distinct cellular pathways were affected by the nongenotoxic carcinogens compared to the genotoxic carcinogens which at least partly correlated with the two-stage model of carcinogenesis. Characteristic to genotoxic carcinogens were a DNA damage response and the activation of proliferative and survival signaling. Nongenotoxic carcinogens showed responses to oxidative DNA or protein damage, as well as cell cycle progression and signs of regeneration. Many of the gene alterations found with the nongenotoxic carcinogens imply compound-specific mechanisms. Although neither a single gene nor a single pathway will be

  1. Feature Selection Model Based Content Analysis for Combating Web Spam

    Directory of Open Access Journals (Sweden)

    Shipra Mittal

    2016-04-01

    Full Text Available With the increasing growth of Internet and World Wi de Web, information retrieval (IR has attracted much attention in recent years. Quick, ac curate and quality information mining is the core concern of successful search companies. Likewi se, spammers try to manipulate IR system to fulfil their stealthy needs. Spamdexing, (also known as web spamming is one of the spamming techniques of adversarial IR, allowing use rs to exploit ranking of specific documents in search engine result page (SERP. Spammers take advantage of different features of web indexing system for notorious motives. Suitable mac hine learning approaches can be useful in analysis of spam patterns and automated detection o f spam. This paper examines content based features of web documents and discusses the potenti al of feature selection (FS in upcoming studies to combat web spam. The objective of featu re selection is to select the salient features to improve prediction performance and to understand th e underlying data generation techniques. A publically available web data set namely WEBSPAM - UK2007 is used for all evaluations.

  2. Systems biology perspectives on the carcinogenic potential of radiation

    International Nuclear Information System (INIS)

    This review focuses on recent experimental and modeling studies that attempt to define the physiological context in which high linear energy transfer (LET) radiation increases epithelial cancer risk and the efficiency with which it does so. Radiation carcinogenesis is a two-compartment problem: ionizing radiation can alter genomic sequence as a result of damage due to targeted effects (TE) from the interaction of energy and DNA; it can also alter phenotype and multicellular interactions that contribute to cancer by poorly understood non-targeted effects (NTE). Rather than being secondary to DNA damage and mutations that can initiate cancer, radiation NTE create the critical context in which to promote cancer. Systems biology modeling using comprehensive experimental data that integrates different levels of biological organization and time-scales is a means of identifying the key processes underlying the carcinogenic potential of high-LET radiation. We hypothesize that inflammation is a key process, and thus cancer susceptibility will depend on specific genetic predisposition to the type and duration of this response. Systems genetics using novel mouse models can be used to identify such determinants of susceptibility to cancer in radiation sensitive tissues following high-LET radiation. Improved understanding of radiation carcinogenesis achieved by defining the relative contribution of NTE carcinogenic effects and identifying the genetic determinants of the high-LET cancer susceptibility will help reduce uncertainties in radiation risk assessment

  3. The multitude and diversity of environmental carcinogens.

    OpenAIRE

    Belpomme, Dominique; Irigaray, Philippe; Hardell, Lennart; Clapp, Richard; Montagnier, Luc; Epstein, Slava; Sasco, Annie

    2007-01-01

    We have recently proposed that lifestyle-related factors, screening and aging cannot fully account for the present overall growing incidence of cancer. In order to propose the concept that in addition to lifestyle related factors, exogenous environmental factors may play a more important role in carcinogenesis than it is expected, and may therefore account for the growing incidence of cancer, we overview herein environmental factors, rated as certainly or potentially carcinogenic by the Inter...

  4. RADON AND CARCINOGENIC RISK IN MOSCOW

    Directory of Open Access Journals (Sweden)

    S. M. Golovanev

    2015-01-01

    Full Text Available Objective: comparative evaluation of carcinogenic risk inMoscowfrom radon in indoor and atmospheric pollutants.Materials and methods: the lung cancer incidence in Moscow; radiation-hygienic passport of the territory; .U.S. EPA estimated average age at all and radon induced deaths, years of life lost; Report of UNSCEAR 2006 and WHO handbook on indoor radon, 2009. Trend analysis of incidence; evaluation of the excess relative risk; assessment of ratio radon-induced population risk and published values оf total population carcinogenic risk from chemical carcinogens.Results: it is shown that the 304 cases of lung cancer per year (1. 85 10-3 on average from 2006 to 2011 (21280diseases for 70 years in addition to background level induced by radon; the differences in average trends of all lungcancer incidence in the districts can exceed 25%.Conclusion. The potential of risk reduction by measures of mitigation radon concentration exceeds 5 times the cost efficiency to reduce emissions from vehicles and can reduce cancer incidence, on average 236 cases per year; population risk 16520 cases over 70 years or save not less than 2832 person-years of life per year. The annual effect of reducing losses from not-survival of 12 years as a result of radon-induced lung cancer deaths exceeds 14160000 dollars. The evaluating of the carcinogenic risk from radon in accordance with the definition of population risk increases the predictive evaluation of the effectiveness of preventive measures more than twice.

  5. Comparative quality analysis of models of total electron content in the ionosphere

    Science.gov (United States)

    Ivanov, V. B.; Gorbachev, O. A.; Kholmogorov, A. A.

    2016-05-01

    We present a brief description and comparative analysis of the Klobuchar, GEMTEC, and NTCM-GL models of total electron content in the ionosphere. The quality of model performance against experimental data on the total electron content is compared. Statistical estimates for the residual positioning error are obtained for each of these models on the basis of the international Global Navigation Satellite Systems (GNSS) Service data. The GEMTEC and NTCM-GL models are shown to have a higher positioning accuracy than the Klobuchar model. The best results of the ionospheric error correction are provided by the GEMTEC model.

  6. Study of elastic-plastic damage model of cement consolidated soil with high organic content

    Institute of Scientific and Technical Information of China (English)

    CHEN Huie; WANG Qing; CAI Keyi

    2009-01-01

    On the basis of elastic-plastic damage model of cement consolidated soil, the authors took organic contents into reasonable damage variable evolution equation in order to seek relation between the organic contents and parameters in the equation, and established the elastic-plastic damage model of cement consolidated soil considering organic contents. The results show that the parameters change correspondingly with difference of the organic contents. The higher the organic contents are, the less the valves of the parameters such as elastic modulus (E), material parameters (K, n) and damage evolution parameter (ε) become, but the larger strain damage threshold value (εd) of the sample is. Meanwhile, the calculation results obtained from established model are compared with the test data in the condition of common indoors test, which is testified with reliability.

  7. Rethinking Web Design Models: Requirements for Addressing the Content

    OpenAIRE

    Woukeu, Arouna; Carr, Les; Wills, Gary; Hall, Wendy

    2003-01-01

    The objective of hypermedia design models is to produce a well-organised web site. The organisation is undertaken at the level of a particular building-block – an abstract data unit which may match a frame, paragraph or region on a Web page. The increasing sophistication of these models allows the designer to deal with interaction and personalisation, but precludes one of the basic features of hypertext – the text itself. This paper argues that this oversight remains a fundamental problem bec...

  8. Carcinogenic risk of hot-particle exposures

    International Nuclear Information System (INIS)

    It has been suggested that spatially non-uniform radiation exposures, such as those from small radioactive particles ('hot particles'), may be very much more carcinogenic than when the same amount of energy is deposited uniformly throughout a tissue volume. This review provides a brief summary of in vivo and in vitro experimental findings, and human epidemiology data, which can be used to evaluate the veracity of this suggestion. Overall, this supports the contrary view and indicates that average dose, as advocated by the ICRP, is likely to provide a reasonable estimate of carcinogenic risk (within a factor of ∼ ±3). There are few human data with which to address this issue. The limited data on lung cancer mortality following occupational inhalation of plutonium aerosols, and the incidence of liver cancer and leukaemia due to thorotrast administration for clinical diagnosis, do not appear to support a significant enhancement factor. Very few animal studies, including mainly lung and skin exposures, provide any indication of a hot-particle enhancement for carcinogenicity. Some recent in vitro malignant transformation experiments provide evidence for an enhanced cell transformation for hot-particle exposures but, properly interpreted, the effect is modest. Few studies extend below absorbed doses of ∼ 0.1 Gy. (review)

  9. Metabolism, genotoxicity, and carcinogenicity of comfrey.

    Science.gov (United States)

    Mei, Nan; Guo, Lei; Fu, Peter P; Fuscoe, James C; Luan, Yang; Chen, Tao

    2010-10-01

    Comfrey has been consumed by humans as a vegetable and a tea and used as an herbal medicine for more than 2000 years. Comfrey, however, produces hepatotoxicity in livestock and humans and carcinogenicity in experimental animals. Comfrey contains as many as 14 pyrrolizidine alkaloids (PA), including 7-acetylintermedine, 7-acetyllycopsamine, echimidine, intermedine, lasiocarpine, lycopsamine, myoscorpine, symlandine, symphytine, and symviridine. The mechanisms underlying comfrey-induced genotoxicity and carcinogenicity are still not fully understood. The available evidence suggests that the active metabolites of PA in comfrey interact with DNA in liver endothelial cells and hepatocytes, resulting in DNA damage, mutation induction, and cancer development. Genotoxicities attributed to comfrey and riddelliine (a representative genotoxic PA and a proven rodent mutagen and carcinogen) are discussed in this review. Both of these compounds induced similar profiles of 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-derived DNA adducts and similar mutation spectra. Further, the two agents share common mechanisms of drug metabolism and carcinogenesis. Overall, comfrey is mutagenic in liver, and PA contained in comfrey appear to be responsible for comfrey-induced toxicity and tumor induction. PMID:21170807

  10. About the particle structure and content of the standard model

    CERN Document Server

    Jora, Renata

    2015-01-01

    We determine the number and distribution of the fermion states in the standard model based on the possible fermion representations of the gauge bosons. By extracting the even parity scalars from the fermion states we suggest the existence of multiple Higgses arranged in suitable singlets or multiplets of $SU(3)_L$ and $SU(3)_c$.

  11. Using the Integrative Model to Explain How Exposure to Sexual Media Content Influences Adolescent Sexual Behavior

    Science.gov (United States)

    Bleakley, Amy; Hennessy, Michael; Fishbein, Martin; Jordan, Amy

    2011-01-01

    Published research demonstrates an association between exposure to media sexual content and a variety of sex-related outcomes for adolescents. What is not known is the mechanism through which sexual content produces this "media effect" on adolescent beliefs, attitudes, and behavior. Using the Integrative Model of Behavioral Prediction, this…

  12. Experimental and modeling studies of grain size and moisture content effects on radon emanation

    International Nuclear Information System (INIS)

    Some models have already been developed to explain the effect of moisture content on the radon emanation fraction of soil. For this purpose, 'microscopic' soil models, which are easy to deal with mathematically but cannot take grain size into consideration, have been designed. These previous models consist basically of two opposite grain surfaces and pores between the grains. In the present study, in order to study the effect of not only moisture content but also grain size, we present a simple modeling approach based on two 'macroscopic' soil models: (1) a single-grain model and (2) a multiple-grain model. The latter model represents a configuration of spherical grains packed in a simple cubic structure. Based on these soil models and general assumptions, the radon emanation fraction was calculated as a function of grain size or moisture content by Monte Carlo simulation. The results for the multiple-grain model show that the radon emanation fraction is markedly increased with grain sizes ranging from 10 to 100 μm and reaches a constant value of 50% when moisture content is 0% and the radium is uniformly distributed on the grain surface. Moreover, a drastic increase is seen at smaller grain sizes with increasing moisture content. From these results, we concluded that the calculation of radon emanation depends greatly on the pore size between a Ra-bearing grain and a neighboring grain. The validity of the model was also evaluated by comparison to experimental data.

  13. Chemoprevention with Acetylsalicylic Acid, Vitamin D and Calcium Reduces Risk of Carcinogen-induced Lung Tumors

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Burcharth, Jakob; Rosenberg, J; Raskov, Hans

    2013-01-01

    Background/Aim: Research has shown that chemoprevention may be effective against the development of lung cancer. The purpose of the present study was to evaluate the effect of oral chemoprevention in a mouse model of tobacco carcinogen-induced lung tumor.......Background/Aim: Research has shown that chemoprevention may be effective against the development of lung cancer. The purpose of the present study was to evaluate the effect of oral chemoprevention in a mouse model of tobacco carcinogen-induced lung tumor....

  14. A content-oriented model for science exhibit engineering

    DEFF Research Database (Denmark)

    Achiam, Marianne

    2013-01-01

    Recently, science museums have begun to review their educational purposes and redesign their pedagogies. At the most basic level, this entails accounting for the performance of individual exhibits, and indeed, in some cases, research indicates shortcomings in exhibit design: While often successful...... in prompting visitors to carry out intended actions, exhibits do not necessarily promote the intended interpretations of these actions among visitors. Here, the notion of praxeology from didactics research is suggested as a model to remedy this shortcoming. The suggested role of praxeology is twofold......: as a means to operationalize the link between exhibit features and visitor activities; and as a template to transform scientists’ practices in the research context into visitors’ activities in the exhibit context. The resulting model of science exhibit engineering is presented and exemplified, and its...

  15. Carcinogenicity of consumption of red and processed meat: What about environmental contaminants?

    Science.gov (United States)

    Domingo, José L; Nadal, Martí

    2016-02-01

    In October 26, 2015, the International Agency for Research on Cancer (IARC) issued a press release informing of the recent evaluation of the carcinogenicity of red and processed meat consumption. The consumption of red meat and processed meat was classified as "probably carcinogenic to humans", and as "carcinogenic to humans", respectively. The substances responsible of this potential carcinogenicity would be generated during meat processing, such as curing and smoking, or when meat is heated at high temperatures (N-nitroso-compounds, polycyclic aromatic hydrocarbons and heterocyclic aromatic amines). However, in its assessments, the IARC did not make any reference to the role that may pose some carcinogenic environmental pollutants, which are already present in raw or unprocessed meat. The potential role of a number of environmental chemical contaminants (toxic trace elements, polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, polybrominated diphenyl ethers, polychlorinated diphenyl ethers, polychlorinated naphthalenes and perfluoroalkyl substances) on the carcinogenicity of consumption of meat and meat products is discussed in this paper. A case-study, Catalonia (Spain), is specifically assessed, while the influence of cooking on the concentrations of environmental pollutants is also reviewed. It is concluded that although certain cooking processes could modify the levels of chemical contaminants in food, the influence of cooking on the pollutant concentrations depends not only on the particular cooking process, but even more on their original contents in each specific food item. As most of these environmental pollutants are organic, cooking procedures that release or remove fat from the meat should tend to reduce the total concentrations of these contaminants in the cooked meat. PMID:26656511

  16. The physical content of the Sp(1,R) model

    International Nuclear Information System (INIS)

    We analyse the properties of the Sp(1,R) model states using a basis obtained from the deformed harmonic oscillator wave functions. We make an Sp(1,R) calculation for 12C and consider bases obtained from oblate, triaxial and prolate intrinsic states. The deformed basis is obtained by angular momentum projection of vibration phonons, which are associated with giant monopole and quadrupole resonances. (author)

  17. Grain pressure in a model silo as affected by moisture content increase

    Directory of Open Access Journals (Sweden)

    Molenda M.

    2000-12-01

    Full Text Available Swelling pressure of wetted grain was measured in a model silo. Experimental set was designed to simulate the conditions under which grain is subjected to wetting by ambient air of the humidity higher than the equilibrium relative humidity corresponding to the existing moisture content of grain. The model involves super- position of two basic kernel reactions to water supply: (i swelling of kernels, (ii decrease in kernels elasticity with an increase in the moisture content. The model properly describes the relation between swelling pressure and the increase in the moisture content in a range of the moisture content increase up to 0.02. Swelling pressure of the wetted grain is strongly influenced by the initial bulk density which depends on the precompression history. The experiments performed indicate that distribution and value of the swel- ling pressure in the model silo is not uniform and depends on the path of wet air movement.

  18. Dynamical models linking BH masses and DM content

    OpenAIRE

    Buyle, Pieter; Dejonghe, Herwig; Baes, Maarten

    2004-01-01

    We investigate the relation between the dark matter distribution of galaxies and their central supermassive black holes which is suggested by the v_c-sigma relation. Since early-type galaxies appear to have larger black holes than late-type ones, we look for an equivalent pattern in the dark matter distribution as a function of Hubble type. To achieve our goal we use a state-of-the-art modelling code that allows a variety of geometries to be fitted to a combination of radio and optical observ...

  19. Modelling the volatile and organic content of Enceladus' ocean

    Science.gov (United States)

    Sotin, Christophe; Lunine, Jonathan

    2015-04-01

    A variety of Cassini data on Enceladus suggest that the jets of material spraying out of the south polar region of this Saturnian moon are connected to a regional or global ocean below an icy crust -- an ocean in contact with a rocky core [1, 2, 3]. In this study we construct models of the mineralogical and elemental composition of Enceladus' rocky core so as to predict the abundance of species that may provide more detail on the extent of hydrothermal evolution of the ocean and its interaction with the rocky core. Using equations of state of the relevant material, the models are made consistent with the values of the gravity coefficients [1]. We investigate the amount of organic molecules (amino acids and fatty acids) as well as the amount of 40Ar that could be present in Enceladus' deep ocean and, therefore, in the icy grains expelled into space. Some models show that the conditions in Enceladus rocky core can be very similar to those existing in the Earth's oceanic crust, suggesting that all of Enceladus rocky core would have been leached over the age of the solar system. The amount of 40Ar dissolved in the ocean provides constraints on the amount of K in the building blocks of Enceladus, the amount of leaching of the silicate fraction, and the extent of the ocean. Based on chondritic abundances for K, we have calculated that the total potential of 40Ar is about 5.6x1012 kg. We also investigate the amount of organic material that would have been concentrated in the ocean. The Murchison meteorite contains about 60 ppm of amino acids, mainly glycine [4]. Assuming that all the rocky core has been leached by water, the modelled concentration of amino acids exceeds 150 ppm. Carboxylic acids were detected in the Asuka carbonaceous chondrites in Antarctica with values, for example, of 90 nmol/g of benzoic acid. Assuming this value, about 35 ppm of benzoic acid would be present in Enceladus' ocean. The concentrations are larger if the ocean is not global, but rather

  20. Procedural Personas for Player Decision Modeling and Procedural Content Generation

    DEFF Research Database (Denmark)

    Holmgård, Christoffer

    2016-01-01

    How can player models and artificially intelligent (AI) agents be useful in early-stage iterative game and simulation design? One answer may be as ways of generating synthetic play-test data, before a game or level has ever seen a player, or when the sampled amount of play test data is very low....... This thesis explores methods for creating low-complexity, easily interpretable, generative AI agents for use in game and simulation design. Based on insights from decision theory and behavioral economics, the thesis investigates how player decision making styles may be defined, operationalised, and measured...... in specific games. It further explores how simple utility functions, easily defined and changed by game designers, can be used to construct agents expressing a variety of decision making styles within a game, using a variety of contemporary AI approaches, naming the resulting agents "Procedural Personas...

  1. Towards Cognizant Hearing Aids: Modeling of Content, Affect and Attention

    DEFF Research Database (Denmark)

    Karadogan, Seliz

    Hearing aids improved significantly after the integration of advanced digital signal processing applications. This improvement will continue and evolve through obtaining intelligent, individualized hearing aids integrating top-down (knowledge-based) and bottom-up (signal-based) approaches by making...... use of research done within cognitive science that is the interdisciplinary study of mind and intelligence bringing together various disciplines including Artificial Intelligence, Cognitive Psychology, and Neuroscience. This thesis focuses on three subjects within cognitive science related to hearing...... attention is studied. A computational top-down attention model is presented and behavioral experiments are carried out to investigate the role of top-down task driven attention in the cocktail party problem. Finally, automatic emotion recognition from speech is studied using a dimensional approach and with...

  2. MODELS OF QUALITY MANAGEMENT SYSTEM: CONTENT AND SCOPE

    Directory of Open Access Journals (Sweden)

    Awny ZREKAT

    2015-12-01

    Full Text Available In this article are analyzed methods developed to prevent the wastage of the majority of the benefit from the production process: JIT, Value Engineering and Constructability. These methods were developed parallel to the development of quality control, quality assurance and total quality management.MODELE DE SISTEM AL MANAGEMENTULUI CALITĂŢII: CONŢINUTUL ŞI DOMENIUL DE APLICAREÎn acest articol sunt analizate metodele de prevenire a pierderilor beneficiului majoritar din procesul de producţie: JIT (eficienţa timpului, Valoarea Inginerie, Constructivitate. Aceste metode au fost dezvoltate în paralel cu evoluţia controlului calităţii, asigurarea calităţii şi managementului calităţii totale.

  3. Place prioritization for biodiversity content using species ecological niche modeling

    Directory of Open Access Journals (Sweden)

    Víctor Sánchez-Cordero

    2005-01-01

    Full Text Available Place prioritization for biodiversity representation is essential for conservation planning, particularly in megadiverse countries where high deforestation threatens biodiversity. Given the collecting biases and uneven sampling of biological inventories, there is a need to develop robust models of species’ distributions. By modeling species’ ecological niches using point occurrence data and digitized environmental feature maps, we can predict potential and extant distributions of species in untransformed landscapes, as well as in those transformed by vegetation change (including deforestation. Such distributional predictions provide a framework for use of species as biodiversity surrogates in place prioritization procedures such as those based on rarity and complementarity. Beyond biodiversity conservation, these predictions can also be used for place prioritization for ecological restoration under current conditions and under future scenarios of habitat change (e.g., deforestation scenarios. To illustrate these points, we (1 predict distributions under current and future deforestation scenarios for the Mexican endemic mammal Dipodomys phillipsii, and show how areas for restoration may be selected; and (2 propose conservation areas by combining nonvolant mammal distributional predictions as biodiversity surrogates with place prioritization procedures, to connect decreed natural protected areas in a region holding exceptional biodiversity: the Transvolcanic Belt in central Mexico. La selección de áreas prioritarias de conservación es fundamental en la planeación sistemática de la conservación, particularmente en países de mega-diversidad, en donde la alta deforestación es una de las amenazas a la biodiversidad. Debido a los sesgos taxonómicos y geográficos de colecta de los inventarios biológicos, es indispensable generar modelos robustos de distribución de especies. Al modelar el nicho ecológico de especies usando localidades de

  4. Quantitative structure carcinogenicity relationship for detecting structural alerts in nitroso-compounds

    International Nuclear Information System (INIS)

    Prevention of environmentally induced cancers is a major health problem of which solutions depend on the rapid and accurate screening of potential chemical hazards. Lately, theoretical approaches such as the one proposed here - Quantitative Structure-Activity Relationship (QSAR) - are increasingly used for assessing the risks of environmental chemicals, since they can markedly reduce costs, avoid animal testing, and speed up policy decisions. This paper reports a QSAR study based on the Topological Substructural Molecular Design (TOPS-MODE) approach, aiming at predicting the rodent carcinogenicity of a set of nitroso-compounds selected from the Carcinogenic Potency Data Base (CPDB). The set comprises nitrosoureas (14 chemicals), N-nitrosamines (18 chemicals) C-nitroso-compounds (1 chemical), nitrosourethane (1 chemical) and nitrosoguanidine (1 chemical), which have been bioassayed in male rat using gavage as the route of administration. Here we are especially concerned in gathering the role of both parameters on the carcinogenic activity of this family of compounds. First, the regression model was derived, upon removal of one identified nitrosamine outlier, and was able to account for more than 84% of the variance in the experimental activity. Second, the TOPS-MODE approach afforded the bond contributions - expressed as fragment contributions to the carcinogenic activity - that can be interpreted and provide tools for better understanding the mechanisms of carcinogenesis. Finally, and most importantly, we demonstrate the potentialities of this approach towards the recognition of structural alerts for carcinogenicity predictions

  5. [The Study of the Spectral Model for Estimating Pigment Contents of Tobacco Leaves in Field].

    Science.gov (United States)

    Ren, Xiao; Lao, Cai-lian; Xu, Zhao-li; Jin, Yan; Guo, Yan; Li, Jun-hui; Yang, Yu-hong

    2015-06-01

    Fast and non-destructive measurements of tobacco leaf pigment contents by spectroscopy in situ in the field has great significance in production guidance for nutrient diagnosis and growth monitoring of tobacco in vegetative growth stage, and it is also very important for the quality evaluation of tobacco leaves in mature stage. The purpose of this study is to estimate the chlorophyll and carotenoid contents of tobacco leaves using tobacco leaf spectrum collected in the field. Reflectance spectrum of tobacco leaves in vegetative growth stage and mature stage were collected in situ in the field and the pigment contents of tobacco leaf samples were measured in this study, taking the tobacco leaf samples collected in each and both stages as modeling sets respectively, and using the methods of support vector machine (SVM) and spectral indice to establish the pigment content estimation models, and then compare the prediction performance of the models built by different methods. The study results indicated that the difference of estimation performance by each stage or mixed stages is not significant. For chlorophyll content, SVM and spectral indice modeling methods can both have a well estimation performance, while for carotenoid content, SVM modeling method has a better estimation performance than spectral indice. The coefficient of determination and the root mean square error of SVM model for estimating tobacco leaf chlorophyll content by each stage were 0.867 6 and 0.014 7, while the coefficient of determination and the root mean square error of SVM model for estimating tobacco leaf chlorophyll content by mixed stages were 0.898 6 and 0.012 3; The coefficient of determination and the root mean square error for estimating tobacco leaf carotenoid content by each stage were 0.861 4 and 0.002 5, while the coefficient of determination and the root mean square error of SVM model for estimating tobacco leaf carotenoid content by mixed stages were 0.839 9 and 0.002 5. The

  6. Carcinogen-induced damage to DNA

    International Nuclear Information System (INIS)

    Human cells respond to carcinogen-induced damage in their DNA in at least two ways. The first response, excision repair, proceeds by at least three variations, depending on the nature of the damage. Nucleotide excision results in relatively large repair patches but few free DNA breaks, since the endonuclease step is limiting. Apurinic repair is characterized by the appearance of numerous breaks in the DNA and by short repair patches. The pathways behave as though they function independently. Lymphoic cells derived from a xeroderma pigmentosum complementation group C patient are deficient in their ability to perform nucleotide excision and also to excise 6 methoxyguanine adducts, but they are apurinic repair competent. Organisms may bypass damage in their DNA. Lymphoblastoid cells, including those derived from xeroderma pigmentosum treated with 3H-anti-BPDE, can replicate their DNA at low doses of carcinogen. Unexcised 3H is found in the light or parental strand of the resulting hybrid DNA when replication occurs in medium with BrdUrd. This observation indicates a bypass reaction occurring by a mechanism involving branch migration at DNA growing points. Branch migration in DNA preparations have been observed, but the evidence is that most occurs in BrdUrd-containing DNA during cell lysis. The measurement of the bifilarly substituted DNA resulting from branch migration is a convenient method of estimating the proportion of new synthesis remaining in the vicinity of the DNA growing point. Treatment with carcinogens or caffeine results in accumulation of DNA growing points accompanied by the synthesis of shortened pieces of daughter DNA

  7. Modelling of total electron content measured by the ATS-6 radio beacon experiment. Technical memo

    International Nuclear Information System (INIS)

    The following conclusions can be reached through the model study: A physically realistic model, when used in conjunction with foF2 and Faraday content observations can be used to infer information on neutral winds and electron density profiles. The resulting profiles are in reasonable agreement in summer and equinox with those from a semi-empirical model. The agreement is not good in winter, be cause the assumptions in the semi-empirical night model are unreliable. Nevertheless, the input quantities to the semi-empirical model, when calculated from the results, are more consistent; Neutral winds can sustain the ionization at F-layer peak altitudes in summer, but they cannot account for the Faraday content at night in equinox and winter; and Discrepancies between calculated and observed electron content values can be reduced by a downward proton flux. A small proton flux suffices to explain the discrepancies

  8. RADON AND CARCINOGENIC RISK IN MOSCOW

    OpenAIRE

    S. M. Golovanev

    2015-01-01

    Objective: comparative evaluation of carcinogenic risk inMoscowfrom radon in indoor and atmospheric pollutants.Materials and methods: the lung cancer incidence in Moscow; radiation-hygienic passport of the territory; .U.S. EPA estimated average age at all and radon induced deaths, years of life lost; Report of UNSCEAR 2006 and WHO handbook on indoor radon, 2009. Trend analysis of incidence; evaluation of the excess relative risk; assessment of ratio radon-induced population risk and published...

  9. Indoor air-assessment: Indoor concentrations of environmental carcinogens

    International Nuclear Information System (INIS)

    In the report, indoor concentration data are presented for the following general categories of air pollutants: radon-222, environmental tobacco smoke (ETS), asbestos, gas phase organic compounds, formaldehyde, polycyclic aromatic hydrocarbons (PAH), pesticides, and inorganic compounds. These pollutants are either known or suspect carcinogens (i.e., radon-222, asbestos) or more complex mixtures or classes of compounds which contain known or suspect carcinogens. Concentration data for individual carcinogenic compounds in complex mixtures are usually far from complete. The data presented for complex mixtures often include compounds which are not carcinogenic or for which data are insufficient to evaluate carcinogenicity. Their inclusion is justified, however, by the possibility that further work may show them to be carcinogens, cocarcinogens, initiators or promotors, or that they may be employed as markers (e.g., nicotine, acrolein) for the estimation of exposure to complex mixtures

  10. A carcinogenicity study of sucralose in the CD-1 mouse.

    Science.gov (United States)

    Mann, S W; Yuschak, M M; Amyes, S J; Aughton, P; Finn, J P

    2000-01-01

    The potential carcinogenicity of sucralose was evaluated by feeding groups of 52 male and 52 female CD-1 mice a diet containing sucralose at 0.3% (3000 ppm), 1.0% (10,000 ppm) or 3.0% (30,000 ppm) for 104 weeks. A group of 72 male and 72 female mice received diet without sucralose and served as controls. Week 1 achieved doses ranging from 543 to 5870mg/kg body weight/day in the low-dose males and high-dose females, respectively. Sucralose had no adverse effect on survival. No significant changes attributable to sucralose were found in the clinical condition or behaviour of the mice. Organ weights and the gross appearance of tissues were unaffected by treatment. The mean erythrocyte counts of females receiving the highest dietary concentration were slightly, but statistically significantly, lower than those of the controls after 104 weeks of treatment. Group mean body weight gain at the highest dietary concentration of sucralose was significantly less than that of the control in mice of both sexes. Food consumption, after correction for sucralose content, was lower for female mice, but not statistically significant. Water consumption for male mice receiving the highest dietary concentration was approximately 9% higher than that of the controls. There were statistically significant increases in the incidence of several non-neoplastic findings, but these were not considered to be related to sucralose administration. Treatment with sucralose did not increase the incidence of any tumour or influence the types of tumours observed. It was concluded that sucralose is not carcinogenic in CD-1 mice. The body weight gain and erythrocyte observations at the 3.0% dietary level were of limited biological significance as they were not accompanied by any histopathologic finding and had no impact on survival. The remaining dose levels were judged to have no effects. PMID:10882820

  11. Trace elements and carcinogenicity: a subject in review

    OpenAIRE

    Mulware, Stephen Juma

    2012-01-01

    Cancer is known to be a multi-step process, which involves different stages including initiation, promotion, progression and metastasis. Chemical carcinogens including most trace elements can change any of these processes to induce their carcinogenic effects. Various studies confirm that cancer arises from the accumulation of irreversible DNA damage, which results from multiple mutations in critical genes in the body organ. Chemical carcinogens most often directly or after xenobiotic metaboli...

  12. Inversion of chlorophyll contents by use of hyperspectral CHRIS data based on radiative transfer model

    International Nuclear Information System (INIS)

    Chlorophyll content, the most important pigment related to photosynthesis, is the key parameter for vegetation growth. The continuous spectrum characteristics of ground objects can be captured through hyperspectral remotely sensed data. In this study, based on the coniferous forest radiative transfer model, chlorophyll contents were inverted by use of hyperspectral CHRIS data in the coniferous forest coverage of Changbai Mountain Area. In addition, the sensitivity of LIBERTY model was analyzed. The experimental results validated that the reflectance simulation of different chlorophyll contents was coincided with that of the field measurement, and hyperspectral vegetation indices applied to the quantitative inversion of chlorophyll contents was feasible and accurate. This study presents a reasonable method of chlorophyll inversion for the coniferous forest, promotes the inversion precision, is of significance in coniferous forest monitoring

  13. Topsoil organic carbon content of Europe, a new map based on a generalised additive model

    Science.gov (United States)

    de Brogniez, Delphine; Ballabio, Cristiano; Stevens, Antoine; Jones, Robert J. A.; Montanarella, Luca; van Wesemael, Bas

    2014-05-01

    There is an increasing demand for up-to-date spatially continuous organic carbon (OC) data for global environment and climatic modeling. Whilst the current map of topsoil organic carbon content for Europe (Jones et al., 2005) was produced by applying expert-knowledge based pedo-transfer rules on large soil mapping units, the aim of this study was to replace it by applying digital soil mapping techniques on the first European harmonised geo-referenced topsoil (0-20 cm) database, which arises from the LUCAS (land use/cover area frame statistical survey) survey. A generalized additive model (GAM) was calibrated on 85% of the dataset (ca. 17 000 soil samples) and a backward stepwise approach selected slope, land cover, temperature, net primary productivity, latitude and longitude as environmental covariates (500 m resolution). The validation of the model (applied on 15% of the dataset), gave an R2 of 0.27. We observed that most organic soils were under-predicted by the model and that soils of Scandinavia were also poorly predicted. The model showed an RMSE of 42 g kg-1 for mineral soils and of 287 g kg-1 for organic soils. The map of predicted OC content showed the lowest values in Mediterranean countries and in croplands across Europe, whereas highest OC content were predicted in wetlands, woodlands and in mountainous areas. The map of standard error of the OC model predictions showed high values in northern latitudes, wetlands, moors and heathlands, whereas low uncertainty was mostly found in croplands. A comparison of our results with the map of Jones et al. (2005) showed a general agreement on the prediction of mineral soils' OC content, most probably because the models use some common covariates, namely land cover and temperature. Our model however failed to predict values of OC content greater than 200 g kg-1, which we explain by the imposed unimodal distribution of our model, whose mean is tilted towards the majority of soils, which are mineral. Finally, average

  14. Modified Liu-Carter Compression Model for Natural Clays with Various Initial Water Contents

    Directory of Open Access Journals (Sweden)

    Sen Qian

    2016-01-01

    Full Text Available The initial water content has a significant effect on the compression behaviour of reconstituted clays. This effect has to be considered in the Liu-Carter model to ensure the addition voids ratio only related to soil structure. A modified Liu-Carter compression model is proposed by introducing the empirical equations for reconstituted clays at different initial water contents into the Liu-Carter model. The proposed model is verified against the experimental results from the literature. The simulations by the proposed method are also compared with that by old method where the influence of initial water content is not considered. The results show that the predicted virgin compression curves of natural clays are similar, but the values of b and Δey may be very different.

  15. Selecting ELL Textbooks: A Content Analysis of Language-Teaching Models

    Science.gov (United States)

    LaBelle, Jeffrey T.

    2011-01-01

    Many middle school teachers lack adequate criteria to critically select materials that represent a variety of L2 teaching models. This study analyzes the illustrated and written content of 33 ELL textbooks to determine the range of L2 teaching models represented. The researchers asked to what extent do middle school ELL texts depict frequency and…

  16. Probabilistic conditional reasoning: Disentangling form and content with the dual-source model.

    Science.gov (United States)

    Singmann, Henrik; Klauer, Karl Christoph; Beller, Sieghard

    2016-08-01

    The present research examines descriptive models of probabilistic conditional reasoning, that is of reasoning from uncertain conditionals with contents about which reasoners have rich background knowledge. According to our dual-source model, two types of information shape such reasoning: knowledge-based information elicited by the contents of the material and content-independent information derived from the form of inferences. Two experiments implemented manipulations that selectively influenced the model parameters for the knowledge-based information, the relative weight given to form-based versus knowledge-based information, and the parameters for the form-based information, validating the psychological interpretation of these parameters. We apply the model to classical suppression effects dissecting them into effects on background knowledge and effects on form-based processes (Exp. 3) and we use it to reanalyse previous studies manipulating reasoning instructions. In a model-comparison exercise, based on data of seven studies, the dual-source model outperformed three Bayesian competitor models. Overall, our results support the view that people make use of background knowledge in line with current Bayesian models, but they also suggest that the form of the conditional argument, irrespective of its content, plays a substantive, yet smaller, role. PMID:27416493

  17. Inversion of a radiative transfer model for estimation of rice chlorophyll content using support vector machine

    Science.gov (United States)

    Lv, Jie; Yan, Zhenguo; Wei, Jingyi

    2014-11-01

    Accurate retrieval of crop chlorophyll content is of great importance for crop growth monitoring, crop stress situations, and the crop yield estimation. This study focused on retrieval of rice chlorophyll content from data through radiative transfer model inversion. A field campaign was carried out in September 2009 in the farmland of ChangChun, Jinlin province, China. A different set of 10 sites of the same species were used in 2009 for validation of methodologies. Reflectance of rice was collected using ASD field spectrometer for the solar reflective wavelengths (350-2500 nm), chlorophyll content of rice was measured by SPAD-502 chlorophyll meter. Each sample sites was recorded with a Global Position System (GPS).Firstly, the PROSPECT radiative transfer model was inverted using support vector machine in order to link rice spectrum and the corresponding chlorophyll content. Secondly, genetic algorithms were adopted to select parameters of support vector machine, then support vector machine was trained the training data set, in order to establish leaf chlorophyll content estimation model. Thirdly, a validation data set was established based on hyperspectral data, and the leaf chlorophyll content estimation model was applied to the validation data set to estimate leaf chlorophyll content of rice in the research area. Finally, the outcome of the inversion was evaluated using the calculated R2 and RMSE values with the field measurements. The results of the study highlight the significance of support vector machine in estimating leaf chlorophyll content of rice. Future research will concentrated on the view of the definition of satellite images and the selection of the best measurement configuration for accurate estimation of rice characteristics.

  18. Hepatic metabolism of carcinogenic β-asarone.

    Science.gov (United States)

    Cartus, Alexander T; Stegmüller, Simone; Simson, Nadine; Wahl, Andrea; Neef, Sylvia; Kelm, Harald; Schrenk, Dieter

    2015-09-21

    β-Asarone (1) belongs to the group of naturally occurring phenylpropenes like eugenol or anethole. Compound 1 is found in several plants, e.g., Acorus calamus or Asarum europaeum. Compound 1-containing plant materials and essential oils thereof are used to flavor foods and alcoholic beverages and as ingredients of many drugs in traditional phytomedicines. Although 1 has been claimed to have several positive pharmacological effects, it was found to be genotoxic and carcinogenic in rodents (liver and small intestine). The mechanism of action of carcinogenic allylic phenylpropenes consists of the metabolic activation via cytochrome P450 enzymes and sulfotransferases. In vivo experiments suggested that this pathway does not play a major role in the carcinogenicity of the propenylic compound 1 as is the case for other propenylic compounds, e.g., anethole. Since the metabolic pathways of 1 have not been investigated and its carcinogenic mode of action is unknown, we investigated the metabolism of 1 in liver microsomes of rats, bovines, porcines, and humans using (1)H NMR, HPLC-DAD, and LC-ESI-MS/MS techniques. We synthesized the majority of identified metabolites which were used as reference compounds for the quantification and final verification of metabolites. Microsomal epoxidation of the side chain of 1 presumably yielded (Z)-asarone-1',2'-epoxide (8a) which instantly was hydrolyzed to the corresponding erythro- and threo-configurated diols (9b, 9a) and the ketone 2,4,5-trimethoxyphenylacetone (13). This was the main metabolic pathway in the metabolism of 1 in all investigated liver microsomes. Hydroxylation of the side chain of 1 led to the formation of three alcohols at total yields of less than 30%: 1'-hydroxyasarone (2), (E)- and (Z)-3'-hydroxyasarone (4 and 6), with 6 being the mainly formed alcohol and 2 being detectable only in liver microsomes of Aroclor 1254-pretreated rats. Small amounts of 4 and 6 were further oxidized to the corresponding carbonyl

  19. Changes of cerebral contents of neuropeptides in rat models of multiple ischemic dementia (MID)

    International Nuclear Information System (INIS)

    Objective: To investigate the significance of changes of cerebral contents of the neuropeptides somatostatin (SS), arginine vasopressin (AVP) and substance P in rat models of MID. Methods: The rat models consisted of 15 rats undergoing intracarotid injection of autogenous thrombus powder. Another group of 15 rats undergoing sham operation served as controls. Learning and memory ability in these rats was assessed with daily passive avoidance task testing for 10 consecutive days. The animals were sacrificed on 30d and contents of the neuropeptides in tissue homogenate from different areas of brain (frontal cortex, temporal cortex, hippocampus, thalamus and corpus striatum) were measured with (RIA). Results: On the first day of passive avoidance task testing, the frequency of errors in the MID group and the control group was about the same. From the third day on, the frequency of errors in the MID group was significantly higher than that in the control group (P<0.05). The neuropeptides contents of all these cerebral areas in the MID group were significantly higher than those in the control group (P<0.05 or P<0.01) with the only exception of the contents of substance P in thalamus (no significant difference between the contents in the two groups). Conclusion: The impairment of learning and memory in rat models with MID was possibly related to the lowered contents of SS, AVP and substance P in the brain tissue. (authors)

  20. Quantitative inverse modeling of nitrogen content from hyperion data under stress of exhausted coal mining sites

    Institute of Scientific and Technical Information of China (English)

    LU Xia; HU Zhen-qi; GUO Li

    2009-01-01

    Monitoring and evaluating the nutritional status of vegetation under stress from exhausted coal mining sites by hy-per-spectral remote sensing is important in future ecological restoration engineering. The Wangpingcun coal mine, located in the Mentougou district of Beijing, was chosen as a ease study. The ecological damage was analyzed by 3S technology, field investiga-tion and from chemical data. The derivative spectra of the diagnostic absorption bands are derived from the spectra measured in the field and used as characteristic spectral variables. A correlation analysis was conducted for the nitrogen content of the vegetation samples and the first derivative spectrum and the estimation model of nitrogen content established by a multiple stepwise linear regression method. The spatial distribution of nitrogen content was extracted by a parameter mapping method from the Hyperion data which revealed the distribution of the nitrogen content. In addition, the estimation model was evaluated for two evaluation indicators which are important for the precision of the model. Experimental results indicate that by linear regression and parameter mapping, the estimation model precision was very high. The coefficient of determination, R2, was 0.795 and the standard deviation of residual (SDR) 0.19. The nitrogen content of most samples was about 1.03% and the nitrogen content in the study site seems inversely proportional to the distance from the piles of coal waste. Therefore, we can conclude that inversely modeling nitrogen content by hyper-speetral remote sensing in exhausted coal mining sites is feasible and our study can be taken as reference in spe-cies selection and in subsequent management and maintenance in ecological restoration.

  1. Embryonic turkey liver: activities of biotransformation enzymes and activation of DNA-reactive carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Perrone, Carmen E.; Duan, Jian Dong; Jeffrey, Alan M.; Williams, Gary M. [New York Medical College, Department of Pathology, Valhalla (United States); Ahr, Hans-Juergen; Schmidt, Ulrich [Bayer AG, Institute of Toxicology, Wuppertal (Germany); Enzmann, Harald H. [Federal Institute for Drugs and Medical Devices, Bonn (Germany)

    2004-10-01

    Avian embryos are a potential alternative model for chemical toxicity and carcinogenicity research. Because the toxic and carcinogenic effects of some chemicals depend on bioactivation, activities of biotransformation enzymes and formation of DNA adducts in embryonic turkey liver were examined. Biochemical analyses of 22-day in ovoturkey liver post-mitochondrial fractions revealed activities of the biotransformation enzymes 7-ethoxycoumarin de-ethylase (ECOD), 7-ethoxyresorufin de-ethylase (EROD), aldrin epoxidase (ALD), epoxide hydrolase (EH), glutathione S-transferase (GST), and UDP-glucuronyltransferase (GLUT). Following the administration of phenobarbital (24 mg/egg) on day 21, enzyme activities of ECOD, EROD, ALD, EH and GLUT, but not of GST, were increased by two-fold or higher levels by day 22. In contrast, acute administration of 3-methylcholanthrene (5 mg/egg) induced only ECOD and EROD activities. Bioactivation of structurally diverse pro-carcinogens was also examined using {sup 32}P-postlabeling for DNA adducts. In ovoexposure of turkey embryos on day 20 of gestation to 2-acetylaminofluorene (AAF), 4,4'-methylenebis(2-chloroaniline) (MOCA), benzo[a]pyrene (BaP), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) resulted in the formation of DNA adducts in livers collected by day 21. Some of the DNA adducts had {sup 32}P-postlabeling chromatographic migration patterns similar to DNA adducts found in livers from Fischer F344 rats exposed to the same pro-carcinogens. We conclude that 21-day embryonic turkey liver is capable of chemical biotransformation and activation of genotoxic carcinogens to form DNA adducts. Thus, turkey embryos could be utilized to investigate potential chemical toxicity and carcinogenicity. (orig.)

  2. Temporal aspects of tumorigenic response to individual and mixed carcinogens. Progress report, October 1, 1978-September 30, 1979

    International Nuclear Information System (INIS)

    The research proposed here is designed to obtain a better understanding of the temporal kinetics of tumor induction when one or more carcinogens are present simultaneously or sequentially for prolonged periods of time. Studies done to date under this contract have shown that carcinogenesis in mouse skin by polycyclic aromatic hydrocarbon carcinogens is consistent with the induction of dependent and autonomous cell transformations by the carcinogen followed by the conversion of autonomous tumor cells into malignancies at a rate which is determined by the level of carcinogen exposure. Dependent cell transformations remain latent in the skin unless expressed by a promoting agent. Dependent neoplasia appears to follow one-hit kinetics while malignancy is a multihit endpoint. Dose-related and time-related aspects of tumor induction are separable in the initiation-promotion system of mouse skin which along with rat skin and hamster lung is being used as a model for testing hypotheses. Results to date provide the basis for a new interpretation of the linear non-threshold extrapolation model. The broad aim of the study is to provide a basis or rationale for estimating risks associated with prolonged exposures to carcinogens found in the environment and to predict how different tissues and species respond to the carcinogens, promoters, and cocarcinogens

  3. Modeling and optimization of cloud-ready and content-oriented networks

    CERN Document Server

    Walkowiak, Krzysztof

    2016-01-01

    This book focuses on modeling and optimization of cloud-ready and content-oriented networks in the context of different layers and accounts for specific constraints following from protocols and technologies used in a particular layer. It addresses a wide range of additional constraints important in contemporary networks, including various types of network flows, survivability issues, multi-layer networking, and resource location. The book presents recent existing and new results in a comprehensive and cohesive way. The contents of the book are organized in five chapters, which are mostly self-contained. Chapter 1 briefly presents information on cloud computing and content-oriented services, and introduces basic notions and concepts of network modeling and optimization. Chapter 2 covers various optimization problems that arise in the context of connection-oriented networks. Chapter 3 focuses on modeling and optimization of Elastic Optical Networks. Chapter 4 is devoted to overlay networks. The book concludes w...

  4. New models for frequency content prediction of earthquake records based on Iranian ground-motion data

    Science.gov (United States)

    Yaghmaei-Sabegh, Saman

    2015-10-01

    This paper presents the development of new and simple empirical models for frequency content prediction of ground-motion records to resolve the assumed limitations on the useable magnitude range of previous studies. Three period values are used in the analysis for describing the frequency content of earthquake ground-motions named as the average spectral period ( T avg), the mean period ( T m), and the smoothed spectral predominant period ( T 0). The proposed models could predict these scalar indicators as function of magnitude, closest site-to-source distance and local site condition. Three site classes as rock, stiff soil, and soft soil has been considered in the analysis. The results of the proposed relationships have been compared with those of other published models. It has been found that the resulting regression equations can be used to predict scalar frequency content estimators over a wide range of magnitudes including magnitudes below 5.5.

  5. Aggregate Interference Modeling in Cognitive Radio Networks with Power and Contention Control

    CERN Document Server

    Chen, Zengmao; Hong, Xuemin; Thompson, John; Vorobyov, Sergiy A; Ge, Xiaohu; Xiao, Hailin; Zhao, Feng

    2010-01-01

    In this paper, we present an interference model for cognitive radio (CR) networks employing power control, contention control or hybrid power/contention control schemes. For the first case, a power control scheme is proposed to govern the transmission power of a CR node. For the second one, a contention control scheme at the media access control (MAC) layer, based on carrier sense multiple access with collision avoidance (CSMA/CA), is proposed to coordinate the operation of CR nodes with transmission requests. The probability density functions of the interference received at a primary receiver from a CR network are first derived numerically for these two cases. For the hybrid case, where power and contention controls are jointly adopted by a CR node to govern its transmission, the interference is analyzed and compared with that of the first two schemes by simulations. Then, the interference distributions under the first two control schemes are fitted by log-normal distributions with greatly reduced complexity...

  6. Morpes: A Model for Personalized Rendering of Web Content on Mobile Devices

    CERN Document Server

    Kuppusamy, K S; 10.5121/ijfcst.2012.2204

    2012-01-01

    With the tremendous growth in the information communication sector, the mobile phones have become the prime information communication devices. The convergence of traditional telephony with the modern web enabled communication in the mobile devices has made the communication much effective and simpler. As mobile phones are becoming the crucial source of accessing the contents of the World Wide Web which was originally designed for personal computers, has opened up a new challenge of accommodating the web contents in to the smaller mobile devices. This paper proposes an approach towards building a model for rendering the web pages in mobile devices. The proposed model is based on a multi-dimensional web page segment evaluation model. The incorporation of personalization in the proposed model makes the rendering user-centric. The proposed model is validated with a prototype implementation.

  7. Is nitrous oxide a genotoxic carcinogen?

    Science.gov (United States)

    O'Donovan, Michael R; Hammond, Timothy G

    2015-07-01

    Nitrous oxide (N2O) has been widely used as a dental and surgical anaesthetic for over 150 years. However, results from a recent study suggested that increased DNA damage was seen in lymphocytes from surgical patients and this led to its continued clinical use to be questioned. The data can be challenged on technical grounds and must be considered with other studies in order to assess any possible risk. There are other studies indicating that N2O has weak genotoxicity in man, but these are confused by exposure of the populations to other anaesthetic gases including isoflurane and sevoflurane, both of which have also been reported to increase DNA damage. It should be noted that the suggested genotoxic mechanisms are all indirect, including folate deficiency, oxidative stress and homocysteine toxicity. Further, results from in vitro studies indicate that N2O has no direct DNA reactivity as negative results were obtained in a bacterial mutation (Ames) test and an assay for mutation at the hprt locus in Chinese hamster lung cells. Although not performed to definitive study designs, no evidence of carcinogenicity was seen in two long-term tests in mice and another in rats. Although there is some evidence that N2O is weakly genotoxic in humans, this appears to be similar to that reported for isoflurane and sevoflurane and all the postulated mechanisms have clear thresholds with no evidence of direct DNA reactivity. Because any potential genotoxic mechanism would have a threshold, it seems reasonable to conclude that neither occasional high exposure to patients as an anaesthetic nor low-level exposure to staff within published recommended exposure limits presents any significant carcinogenic risk. PMID:25852088

  8. Carcinogens in the Workplace: A Scientific, Political and Social Problem

    OpenAIRE

    Atherley, Gordon; Whiting, Robert

    1982-01-01

    Investigation, assessment, and management of carcinogenic risks are not only scientific but also political responsibilities. In Canada, this becomes cumbersome, since local, provincial and federal policies are involved. The process also involves workers and management. This article outlines Canadian legislative experience, the principles involved, the methods of risk assessment, and the classification of carcinogens in the workplace.

  9. Workshop on problem areas associated with developing carcinogen guidelines

    Energy Technology Data Exchange (ETDEWEB)

    1984-06-01

    A workshop was conducted to discuss problem areas associated with developing carcinogen guidelines. Session topics included (1) definition of a carcinogen for regulatory purposes; (2) potency; (3) risk assessment; (4) uncertainties; (5) de minimis quantity; and (6) legal and regulatory issues. Separate abstracts have been prepared for individual papers. (ACR)

  10. Environmental carcinogenic agents and cancer prevention. Risk assessment and management

    International Nuclear Information System (INIS)

    Many agents in our environment have been established as being carcinogenic, and in most cases, the carcinogenic properties of these agents were identified because of high-dose occupational or accidental exposure. Risk characterization, taking into account the dose-response relationship, and exposure assessment are essential for risk assessment and subsequent cancer prevention. Based on scientific risk assessment, risk management should be conducted practically by considering the economic, social, political, and other technical issues and by balancing the risks and benefits. Asbestos and environmental tobacco smoke are typical examples of established carcinogenic agents in the general environment, contributing to low-dose exposure. Further epidemiological studies are required to investigate the carcinogenicity of low-dose exposure to known carcinogenic agents such as arsenic and cadmium through dietary intake, radiation via medical and natural exposure, and air pollution due to diesel exhaust. In contrast, occupational chemical exposure to 1,2-dichloropropane and/or dichloromethane, whose carcinogenicity had not been established, was suggested to cause cholangiocarcinoma among workers involved in offset color proof-printing only after a rare situation of high-dose exposure was unveiled. Continuous monitoring of unusual cancer occurrences in target populations such as workers in occupational and regional settings as well as exposure reduction to suspected carcinogenic agents to levels as low as reasonably achievable is essential for reducing the risk of cancer due to environmental carcinogens. (author)

  11. Researchers exploring faster alternatives to 2-year test for carcinogenicity.

    OpenAIRE

    Schmidt, Charlie

    2006-01-01

    KEYWORDS - CLASSIFICATION: Animals;Animals,Laboratory;biomarkers of exposure & effect: validation;Carcinogenicity Tests;Carcinogens;Female;metabolism;methods;Male;Mice;Pharmaceutical Preparations;Predictive Value of Tests;Prognosis;Rats;standards;Species Specificity;trends;Time Factors;Tumor Markers,Biological;United States;United States Environmental Protection Agency;United States Food and Drug Administration.

  12. 29 CFR 1926.1103 - 13 carcinogens (4-Nitrobiphenyl, etc.).

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false 13 carcinogens (4-Nitrobiphenyl, etc.). 1926.1103 Section 1926.1103 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... § 1926.1103 13 carcinogens (4-Nitrobiphenyl, etc.). Note: The requirements applicable to...

  13. 29 CFR 1915.1003 - 13 carcinogens (4-Nitrobiphenyl, etc.).

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false 13 carcinogens (4-Nitrobiphenyl, etc.). 1915.1003 Section 1915.1003 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... Hazardous Substances § 1915.1003 13 carcinogens (4-Nitrobiphenyl, etc.). Note: The requirements...

  14. 29 CFR 1910.1003 - 13 Carcinogens (4-Nitrobiphenyl, etc.).

    Science.gov (United States)

    2010-07-01

    ... employees, designated representatives, and the Assistant Secretary in accordance with 29 CFR 1910.1020 (a... 29 Labor 6 2010-07-01 2010-07-01 false 13 Carcinogens (4-Nitrobiphenyl, etc.). 1910.1003 Section... Substances § 1910.1003 13 Carcinogens (4-Nitrobiphenyl, etc.). (a) Scope and application. (1) This...

  15. Bulk volumetric liquid water content in a seasonal snowpack: modeling its dynamics in different climatic conditions

    Science.gov (United States)

    Avanzi, Francesco; Yamaguchi, Satoru; Hirashima, Hiroyuki; De Michele, Carlo

    2015-12-01

    We focus on the dynamics of volumetric liquid water content in seasonal snow covers. This is a key variable describing the fate of snowpacks during the melting season. However, its measurement and/or prediction by means of models at high spatial and temporal resolutions is still difficult due to both practical and theoretical reasons. To overcome these limitations in operational applications, we test the capability of a one-dimensional model to predict the dynamics of bulk volumetric liquid water content during a snow season. Multi-year data collected in three experimental sites in Japan are used as an evaluation. These sites are subjected to different climatic conditions. The model requires the calibration of one or two parameters, according to the degree of detail used. Either a simple temperature-index or a coupled melt-freeze temperature-index approach are considered to predict melting and/or melt-freeze dynamics of liquid water. Results show that, if melt-freeze dynamics are modeled, median absolute differences between data and predictions are consistently lower than 1 vol% at the sites where data of liquid water content are available. In addition, we find also that the model predicts correctly a dry condition in 80% of the observed cases at a site where calibration data are scarce. At the same site, observed isothermal conditions of the snow cover at 0 °C correspond to predictions of bulk volumetric liquid water content that are greater than 0.

  16. Occurrence of the carcinogenic Bracken constituent ptaquiloside in fronds, topsoils and organic soil layers in Denmark

    DEFF Research Database (Denmark)

    Rasmussen, L.H.; Kroghsbo, S.; Frisvad, Jens Christian;

    2003-01-01

    Bracken (Pteridium aquilinum (L.) Kuhn) is a common fern found on all continents except Antarctica. It is under suspicion of causing cancer among people who utilizes it as food. The main carcinogenic compound is thought to be the water-soluble compound ptaquiloside. Ptaquiloside-uptake may occur...... Bracken-litter, the turnover rate and the size of Bracken-stands determined the ptaquiloside-content in the soil materials while the content in fronds was found to be a function of the frond-height and the light-exposure in the ecosystem....

  17. Archetype-based conversion of EHR content models: pilot experience with a regional EHR system

    Directory of Open Access Journals (Sweden)

    Karlsson Daniel

    2009-07-01

    Full Text Available Abstract Background Exchange of Electronic Health Record (EHR data between systems from different suppliers is a major challenge. EHR communication based on archetype methodology has been developed by openEHR and CEN/ISO. The experience of using archetypes in deployed EHR systems is quite limited today. Currently deployed EHR systems with large user bases have their own proprietary way of representing clinical content using various models. This study was designed to investigate the feasibility of representing EHR content models from a regional EHR system as openEHR archetypes and inversely to convert archetypes to the proprietary format. Methods The openEHR EHR Reference Model (RM and Archetype Model (AM specifications were used. The template model of the Cambio COSMIC, a regional EHR product from Sweden, was analyzed and compared to the openEHR RM and AM. This study was focused on the convertibility of the EHR semantic models. A semantic mapping between the openEHR RM/AM and the COSMIC template model was produced and used as the basis for developing prototype software that performs automated bi-directional conversion between openEHR archetypes and COSMIC templates. Results Automated bi-directional conversion between openEHR archetype format and COSMIC template format has been achieved. Several archetypes from the openEHR Clinical Knowledge Repository have been imported into COSMIC, preserving most of the structural and terminology related constraints. COSMIC templates from a large regional installation were successfully converted into the openEHR archetype format. The conversion from the COSMIC templates into archetype format preserves nearly all structural and semantic definitions of the original content models. A strategy of gradually adding archetype support to legacy EHR systems was formulated in order to allow sharing of clinical content models defined using different formats. Conclusion The openEHR RM and AM are expressive enough to

  18. Comparison of rat olfactory mucosal responses to carcinogenic and non-carcinogenic chloracetanilides

    OpenAIRE

    Genter, M.B.; Warner, B.M.; Medvedovic, M.; Sartor, M.A.

    2009-01-01

    Alachlor and butachlor are chloracetanilide herbicides that induce olfactory tumors in rats, whereas propachlor does not. The mechanism by which alachlor induces tumors is distinct from many other nasal carcinogens, in that alachlor induces a gradual de-differentiation of the olfactory mucosa (OM) to a more respiratory-like epithelium, in contrast to other agents that induce cytotoxicity, followed by an aberrant regenerative response. We studied biochemical and genomic effects of these compou...

  19. Lymphocyte reactivity of workers exposed to carcinogenic and non-carcinogenic chemicals.

    OpenAIRE

    Kumar, S.; Taylor, G; Hurst, W; Wilson, P.; Costello, C B

    1981-01-01

    Immunological studies have shown an increased lymphocyte reactivity in patients with early stage bladder cancer and individuals with pre-stage T1 exposed to bladder carcinogens (2-naphthylamine and industrial 1-naphthylamine containing 4-8% 2-naphthylamine) before 1952-that is, those at high risk of developing bladder cancer. Because of the close chemical similarity of Tobias acid (2-naphthylamine-1 sulphonic acid) to 2-naphthylamine, the lymphocytotoxicity of workers exposed to this chemical...

  20. A Novel Stackelberg-Bertrand Game Model for Pricing Content Provider

    Directory of Open Access Journals (Sweden)

    Cheng Zhang

    2015-11-01

    Full Text Available With the popularity of smart devices such as smartphone, tablet, contents that traditionally be viewed on a personal computer, can also be viewed on these smart devices. The demand for contents thus is increasing year by year, which makes the content providers (CPs get great revenue from either users’ subscription or advertisement. On the other hand, Internet service providers (ISPs, who keep investing in the network technology or capacity capacity to support the huge traffic generated by contents, do not benefit directly from the content traffic. One choice for ISPs is to charge CPs to share the revenue from the huge content traffic. Then ISPs have enough incentives to invest in network infrastructure to improve quality of services (QoS, which eventually benefit CPs and users. This paper presents a novel economic model called Stackelberg-Bertrand game to capture the interaction and competitions among ISPs, CPs and users when ISPs charge CPs. A generic user demand function is assumed to capture the sensitivity of demand to prices of ISPs and CPs. The numerical results show that the price elasticity of ISP and CP plays an important part on the payoff of the ISP and CP.

  1. WoT model for authenticity contents in virtual learning platforms

    OpenAIRE

    Jesús Soto-Carrión; Paulo A. Gaona-Garcia

    2009-01-01

    The following research proposal seeks to bring a model of security software on virtual learning platforms LCMS under all SCORM specifications to ensure the authenticity of content created under concepts of digital signature and identification of protocols and mechanisms to ensure such activities.

  2. Validity of Multiprocess IRT Models for Separating Content and Response Styles

    Science.gov (United States)

    Plieninger, Hansjörg; Meiser, Thorsten

    2014-01-01

    Response styles, the tendency to respond to Likert-type items irrespective of content, are a widely known threat to the reliability and validity of self-report measures. However, it is still debated how to measure and control for response styles such as extreme responding. Recently, multiprocess item response theory models have been proposed that…

  3. Beacon satellite studies and modelling of total electron contents of the ionosphere

    International Nuclear Information System (INIS)

    An attempt is made to highlight some of the beacon satellite studies, particularly those relating to total electron content (TEC) and scintillations, with special attention to Indian subcontinent observations. The modelling of TEC is described. The scope of new experiments for specific problem is indicated. (author). 78 refs., 12 figs

  4. Biological Model Development as an Opportunity to Provide Content Auditing for the Foundational Model of Anatomy Ontology

    OpenAIRE

    Wang, Lucy L.; Grunblatt, Eli; Jung, Hyunggu; Kalet, Ira J.; Whipple, Mark E.

    2015-01-01

    Constructing a biological model using an established ontology provides a unique opportunity to perform content auditing on the ontology. We built a Markov chain model to study tumor metastasis in the regional lymphatics of patients with head and neck squamous cell carcinoma (HNSCC). The model attempts to determine regions with high likelihood for metastasis, which guides surgeons and radiation oncologists in selecting the boundaries of treatment. To achieve consistent anatomical relationships...

  5. Comparison of experimental slant electron content and IRI model for moderate solar activity conditions

    International Nuclear Information System (INIS)

    The International Reference Ionosphere model only gives the vertical electron content (VTEC). In this paper the slant electron content (SEC) for the ATS 6 satellite - Palehua (21.4 deg. N, 201.9 deg. E) radio signal path for a middle solar activity year is calculated. To this end, IRI model is used to obtain the electron density at different points of the signal path. Equinoxes and solstices are considered. Measurements obtained with Faraday rotation technique at Palehua are compared with the modelled values. Although overestimation was observed for night hours, the results show good SEC predictions for several hours at period of maximum ionisation, suggesting that would be possible to model the STEC using IRI. (author)

  6. Power and Contention Control Scheme: As a Good Candidate for Interference Modeling in Cognitive Radio Network

    Directory of Open Access Journals (Sweden)

    Ireyuwa E. Igbinosa

    2015-10-01

    Full Text Available Due to the ever growing need for spectrum, the cognitive radio (CR has been proposed to improve the radio spectrum utilization. In this scenario, the secondary users (SU are permitted to share spectrum with the licensed primary users (SU with a strict condition that they do not cause harmful interference to the cognitive network. In this work, we have proposed an interference model for cognitive radio network that utilizes power or contention control interference management schemes. We derived the probability density function (PDF with the power control scheme, where the power of transmission of the CR transmitter is guided by the power control law and also with contention control scheme that has a fixed transmission power for all CR transmitter controlled by a contention control protocol. This protocol makes a decision on which CR transmitter can transmit at any point in time. In this work, we have shown that power and contention control schemes are good candidates for interference modeling in cognitive radio system. The impact of the unknown location of the primary receiver on the resulting interference generated by the CR transmitters was investigated and the results shows that the challenges of the hidden primary receivers lead to higher CR-primary interference in respect to higher mean and variance. Finally, the presented results show power control and the contention control scheme are good candidates in reducing the interference generated by the cognitive radio network.

  7. Bioavailability and potential carcinogenicity of polycyclic aromatic hydrocarbons from wood combustion particulate matter in vitro.

    Science.gov (United States)

    Gauggel-Lewandowski, Susanne; Heussner, Alexandra H; Steinberg, Pablo; Pieterse, Bart; van der Burg, Bart; Dietrich, Daniel R

    2013-11-25

    Due to increasing energy demand and limited fossil fuels, renewable energy sources have gained in importance. Particulate matter (PM) in general, but also PM from the combustion of wood is known to exert adverse health effects in human. These are often related to specific toxic compounds adsorbed to the PM surface, such as polycyclic aromatic hydrocarbons (PAH), of which some are known human carcinogens. This study focused on the bioavailability of PAHs and on the tumor initiation potential of wood combustion PM, using the PAH CALUX® reporter gene assay and the BALB/c 3T3 cell transformation assay, respectively. For this, both cell assays were exposed to PM and their respective organic extracts from varying degrees of combustion. The PAH CALUX® experiments demonstrated a concentration-response relationship matching the PAHs detected in the samples. Contrary to expectations, PM samples from complete (CC) and incomplete combustion (IC) provided for a stronger and weaker response, respectively, suggesting that PAH were more readily bioavailable in PM from CC. These findings were corroborated via PAH spiking experiments indicating that IC PM contains organic components that strongly adsorb PAH thereby reducing their bioavailability. The results obtained with organic extracts in the cell transformation assay presented the highest potential for carcinogenicity in samples with high PAH contents, albeit PM from CC also demonstrated a carcinogenic potential. In conclusion, the in vitro assays employed emphasize that CC produces PM with low PAH content however with a general higher bioavailability and thus with a nearly similar carcinogenic potential than IC PM. PMID:23796820

  8. Modeling the Dispersion and Polarization Content of Gravitational Waves for Tests of General Relativity

    CERN Document Server

    Tso, Rhondale; Chen, Yanbei; Stein, Leo

    2016-01-01

    We propose a generic, phenomenological approach to modifying the dispersion of gravitational waves, independent of corrections to the generation mechanism. This model-independent approach encapsulates all previously proposed parametrizations, including Lorentz violation in the Standard-Model Extension, and provides a roadmap for additional theories. Furthermore, we present a general approach to include modulations to the gravitational-wave polarization content. The framework developed here can be implemented in existing data analysis pipelines for future gravitational-wave observation runs.

  9. Using a single content model for eHealth interoperability and secondary use.

    Science.gov (United States)

    Atalag, Koray

    2013-01-01

    This chapter describes a middle-out approach to eHealth interoperability, with strong oversight on public health and health research, enabled by a uniform and shared content model to which all health information exchange conforms. As described in New Zealand's Interoperability Reference Architecture, the content model borrows its top level organization from the Continuity of Care Record (CCR) standard and is underpinned by the openEHR formalism. This provides a canonical model for representing a variety of clinical information, and serves as reference when determining payload in health information exchange. The main premise of this approach is that since all exchanged data conforms to the same model, interoperability of clinical information can readily be achieved. Use of Archetypes ensures preservation of clinical context which is critical for secondary use. The content model is envisaged to grow incrementally by adding new or specialised archetypes as finer details are needed in real projects. The consistency and long term viability of this approach critically depends on effective governance which requires new models of collaboration, decision making and appropriate tooling to support the process. PMID:24018523

  10. [Development of prediction models for determining N content in citrus leaves based on hyperspectral imaging technology].

    Science.gov (United States)

    Li, Jin-Meng; Ye, Xu-Jun; Wang, Qiao-Nan; Zhang, Chu; He, Yong

    2014-01-01

    The present study presents prediction models for determining the N content in citrus leaves by using hyperspectral imaging technology combined with several chemometrics methods. The steps followed in this study are: hyperspectral image scanning, extracting average spectra curves, pretreatment of raw spectra data, extracting characteristic wavelengths with successive projection algorithm and developing prediction models for determining N content in citrus leaves. The authors obtained three optimal pretreatment methods through comparing eleven different pretreatment methods including Savitzky-Golay (SG) smoothing, standard normal variate (SNV), multiplicative scatter correction (MSC), first derivative (1-Der) and so on. These selected pretreatment methods are SG smoothing, detrending and SG smoothing-detrending. Based on these three pretreatment methods, the authros first extracted the characteristic wavelengths respectively with successive projection algorithm, and then used the spectral reflectance of the extracted characteristic wavelengths as input variables of partial least squares regression (PLS), multiple linear regression (MLR) and back propagation neural network (BPNN) modeling. Hence, the authors developed three prediction models with each pretreatment method, and obtained nine models in total. Among all the nine prediction models, the two models based on the methods of SG smoothing-detrending-SPA-BPNN (R(p): 0.8513, RMSEP: 0.1881) and detrending-SPABPNN (R(p): 0.8609, RMSEP: 0.1595) were found to have achieved the best prediction results. The final results show that using hyperspectra data to determine N content in citrus leaves is feasible. This would provide a theoretical basis for real-time and accurate monitoring of N content in citrus leaves as well as rational N fertilizer application during the plant's growth. PMID:24783563

  11. PCDD/PCDF soil contents near incineration plants - numerical modelling versus analytical measurement

    International Nuclear Information System (INIS)

    In connection with law-imposed waste disposal regulations concerning the modernisation of the incineration ''Munich-North'', local authorities and residents raised objections. Based on an immission calculation using a numerical model concerning the impact of PCDD/PCDF on the soil (study I), conclusions were drawn that the former immissions were so high that further impact on the soil by a new combustion plant was no longer tolerable. The results of study I were controlled using a different numerical model calculation (study II). The simulation results varied vastly because of the differences in preliminary input parameters. In order to verify the simulations, soil samples were taken and the content of PCDD/PCDF was determined. Predicted soil-contents of study II were in the same range as the analyzed samples, whereas the values of study I were higher. With one exception, the soil contents were less than 5 ng TEQ-BGA kg-1 mT, a value below the BGA limits. Calculations by numerical modelling, compared to the measurement of PCDD/PCDF soil contents, are therefore no reliable basis for predicting PCDD/PCDF concentrations in soils which has been induced by incineration emission. (orig.)

  12. Decision Making Model for Business Process Outsourcing of Enterprise Content Management

    Directory of Open Access Journals (Sweden)

    Zhuojun Yi

    2013-03-01

    Full Text Available Business process outsourcing (BPO in enterprise content management (ECM is a growing though immature market. BPO in ECM focuses on pursuing market transactions in the process of managing all types of content being used in organizations. However, inadequate sourcing decisions lead to organizational sensitive content exposure, high transaction cost, poor outsourcer performance, low flexibility. ECM BPO in general is rarely discussed in the literature and no discussion was found on decision making strategies in ECM BPO. In this paper, we present a decision making model for ECM BPO that will fill the literature gap and guide industry practitioners with ECM sourcing decision making strategies. Our proposed decision making model includes two parts. Part one is an ECM functional framework that shows what functionality component or functionality combinations can be outsourced. Part two is a decision making model that provides guidance for decision making in ECM BPO. We apply the model in two case studies, and the results indicate that the model can guide the sourcing decision making process for organizations, and determine the factors when considering sourcing alternatives in ECM.

  13. Metabolic activation of chemical carcinogens to reactive electrophiles

    International Nuclear Information System (INIS)

    Ionizing radiations and ultraviolet light constitute the principal known physical carcinogens. Likewise, a great variety and large number of chemicals and over 50 DNA and RNA viruses comprise the known chemical and viral carcinogens. These three categories of carcinogenic agents include the great majority of extrinsic agents known to induce cancer in mammals. Man is clearly susceptible to the action of physical and chemical carcinogens and, indeed, was the first species in which the activities of some of these agents were demonstated. It seems certain that viral carcinogenic information is involved in the etiology of at least some human tumors, but ethical and methodological problems have made it difficult to obtain unequivocal data. Given the long availability of experimental carcinogens of these three classes, there is surprisingly little known of their interrelationships in the production of cancer in experimental animals. The objective of this brief review is to present some salient aspects of experimental chemical carcinogenesis and an analysis of how some of these features relate to the mechanisms of action of radiation carcinogens

  14. Identification and monitoring of non-radiological carcinogens

    International Nuclear Information System (INIS)

    This study examines the feasibility of identifying and monitoring occupational exposures to non-radiological carcinogens in the workplace at Canadian nuclear establishments (Whiteshell Laboratories, Pickering Nuclear Generating Station, Cameco Limited and Canadian General Electric Company Limited). Recent epidemiological studies recommended that potential confounding factors of a non-radiological nature be identified and analyzed, particularly non-radiological carcinogens that may be present in the workplace at nuclear facilities. The feasibility of identifying and measuring occupational exposures to non-radiological carcinogens in Canadian nuclear facilities is examined. Also, the report describes the problem of chemical carcinogens and the mechanisms involved in chemical carcinogenesis; the epidemiology related to the problem, followed by a description of the analytical aspects of detection, monitoring and analysis of carcinogens, as well as a discussion on the regulatory aspects and the regulations in place; and the findings, recommendations and concluding remarks of this study. Several problem areas became apparent as the study proceeded. For example, the classification of a chemical as a human carcinogen is a difficult problem, as is its adequate monitoring and analysis. This situation reflects, in turn, the regulatory aspects in the workplace. A list of chemical carcinogens used industrially at the four Canadian nuclear facilities has been identified. The list includes arsenic, asbestos, benzene, cadmium, beryllium, nickel, polychlorinated biphenyls, lead and trichloroethylene. Several recommendations are made in relation to the need for practical and efficient monitoring methods for chemical carcinogens, the definition of radiation and chemical dose equivalencies, and the classification of human chemical carcinogens, as well as their disposal. (author). 122 refs., 8 tabs., 6 figs

  15. Detection of genotoxic and non-genotoxic carcinogens in Xpc{sup −/−}p53{sup +/−} mice

    Energy Technology Data Exchange (ETDEWEB)

    Melis, Joost P.M. [Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Leiden University Medical Center, Department of Toxicogenetics, Leiden (Netherlands); Speksnijder, Ewoud N. [Leiden University Medical Center, Department of Toxicogenetics, Leiden (Netherlands); Kuiper, Raoul V. [Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Dutch Molecular Pathology Center, Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht (Netherlands); Salvatori, Daniela C.F. [Leiden University Medical Center, Central Animal Facility, Leiden (Netherlands); Schaap, Mirjam M. [Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Leiden University Medical Center, Department of Toxicogenetics, Leiden (Netherlands); Maas, Saskia [Leiden University Medical Center, Central Animal Facility, Leiden (Netherlands); Robinson, Joke; Verhoef, Aart; Benthem, Jan van; Luijten, Mirjam [Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Steeg, Harry van, E-mail: Harry.van.Steeg@rivm.nl [Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Leiden University Medical Center, Department of Toxicogenetics, Leiden (Netherlands)

    2013-01-15

    An accurate assessment of the carcinogenic potential of chemicals and pharmaceutical drugs is essential to protect humans and the environment. Therefore, substances are extensively tested before they are marketed to the public. Currently, the rodent two-year bioassay is still routinely used to assess the carcinogenic potential of substances. However, over time it has become clear that this assay yields false positive results and also has several economic and ethical drawbacks including the use of large numbers of animals, the long duration, and the high cost. The need for a suitable alternative assay is therefore high. Previously, we have proposed the Xpa*p53 mouse model as a very suitable alternative to the two-year bioassay. We now show that the Xpc*p53 mouse model preserves all the beneficial traits of the Xpa*p53 model for sub-chronic carcinogen identification and can identify both genotoxic and non-genotoxic carcinogens. Moreover, Xpc*p53 mice appear to be more responsive than Xpa*p53 mice towards several genotoxic and non-genotoxic carcinogens. Furthermore, Xpc*p53 mice are far less sensitive than Xpa*p53 mice for the toxic activity of DNA damaging agents and as such clearly respond in a similar way as wild type mice do. These advantageous traits of the Xpc*p53 model make it a better alternative for in vivo carcinogen testing than Xpa*p53. This pilot study suggests that Xpc*p53 mice are suited for routine sub-chronic testing of both genotoxic and non-genotoxic carcinogens and as such represent a suitable alternative to possibly replace the murine life time cancer bioassay. Highlights: ► The Xpc*p53 mouse model is able to identify genotoxic and non-genotoxic carcinogens. ► Time, animals and cost can be significantly reduced compared to the 2-year bioassay. ► Xpc*p53 mice are more advantageous for carcinogen identification than Xpa*p53 mice. ► Xpc*p53 mice exhibit a wild type response upon exposure to genotoxicants.

  16. Biologic markers in risk assessment for environmental carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Perera, F.; Mayer, J.; Santella, R.M.; Brenner, D.; Jeffrey, A.; Latriano, L.; Smith, S.; Warburton, D.; Young, T.L.; Tsai, W.Y.; Brandt-Rauf, P. (Columbia Univ. School of Public Health, New York, NY (United States)); Hemminki, K. (Finnish School of Occupational Health, Helsinki (Finland))

    1991-01-01

    The potential of biologic markers to provide more timely and precise risk assessments for environmental carcinogens is viewed against the current state-of-the-art in biological monitoring/molecular epidemiology. Biologic markers such as carcinogen-DNA adducts and oncogene activation are currently considered valid qualitative indicators of potential risk, but for most chemical exposures research is needed to establish their validity as quantitative predictors of cancer risk. Biologic markers have, however, already provided valuable insights into the magnitude of interindividual variation in response to carcinogenic exposures, with major implications for risk assessment.

  17. Biologic markers in risk assessment for environmental carcinogens

    International Nuclear Information System (INIS)

    The potential of biologic markers to provide more timely and precise risk assessments for environmental carcinogens is viewed against the current state-of-the-art in biological monitoring/molecular epidemiology. Biologic markers such as carcinogen-DNA adducts and oncogene activation are currently considered valid qualitative indicators of potential risk, but for most chemical exposures research is needed to establish their validity as quantitative predictors of cancer risk. Biologic markers have, however, already provided valuable insights into the magnitude of interindividual variation in response to carcinogenic exposures, with major implications for risk assessment

  18. Architecture and Performance Models for QoS-Driven Effective Peering of Content Delivery Networks

    CERN Document Server

    Pathan, Mukaddim

    2009-01-01

    The proprietary nature of existing Content Delivery Networks (CDNs) means they are closed and do not naturally cooperate. A CDN is expected to provide high performance Internet content delivery through global coverage, which might be an obstacle for new CDN providers, as well as affecting commercial viability of existing ones. Finding ways for distinct CDNs to coordinate and cooperate with other CDNs is necessary to achieve better overall service, as perceived by end-users, at lower cost. In this paper, we present an architecture to support peering arrangements between CDNs, based on a Virtual Organization (VO) model. Our approach promotes peering among providers, while upholding user perceived performance. This is achieved through proper policy management of negotiated Service Level Agreements (SLAs) between peers. We also present a Quality of Service (QoS)-driven performance modeling approach for peering CDNs in order to predict the user perceived performance. We show that peering between CDNs upholds user ...

  19. A METHODOLOGICAL MODEL FOR INTEGRATING CHARACTER WITHIN CONTENT AND LANGUAGE INTEGRATED LEARNING IN SOCIOLOGY OF RELIGION

    OpenAIRE

    Moh Yasir Alimi

    2013-01-01

    AbstractIn this article, I describe a methodological model I used in a experimental study on how to integrate character within the practice of Content and Language Integrated Learning (CLIL) at the higher education Indonesia.This research can be added to research about character education and CLIL in tertiary education, giving nuances to the practice of CLIL so far predominantly a practice in primary and secondary schools.The research was conducted in Semarang State University, in the Departm...

  20. Development of Clinical Contents Model Markup Language for Electronic Health Records

    OpenAIRE

    Yun, Ji-Hyun; Ahn, Sun-Ju; Kim, Yoon

    2012-01-01

    Objectives To develop dedicated markup language for clinical contents models (CCM) to facilitate the active use of CCM in electronic health record systems. Methods Based on analysis of the structure and characteristics of CCM in the clinical domain, we designed extensible markup language (XML) based CCM markup language (CCML) schema manually. Results CCML faithfully reflects CCM in both the syntactic and semantic aspects. As this language is based on XML, it can be expressed and processed in ...

  1. Paid content strategies for news websites: An empirical study of British newspapers' online business models

    OpenAIRE

    N. Thurman; Herbert, J

    2007-01-01

    This study uses qualitative research interviews and a survey to quantify and analyse business models at online newspapers in the UK. Senior editors and executives reported that news websites rely on advertising income to a greater extent than their print counterparts. Despite this, British news sites continue to charge users for some content, although to a varying degree. The fact that online editions still contribute barely a tenth of total revenues explains this experimental approach toward...

  2. Effect of the science teaching advancement through modeling physical science professional development workshop on teachers' attitudes, beliefs and content knowledge and students' content knowledge

    Science.gov (United States)

    Dietz, Laura

    The Science Teaching Advancement through Modeling Physical Science (STAMPS) professional development workshop was evaluated for effectiveness in improving teachers' and students' content knowledge. Previous research has shown modeling to be an effective method of instruction for improving student and teacher content knowledge, evidenced by assessment scores. Data includes teacher scores on the Force Concept Inventory (FCI; Hestenes, Wells, & Swackhamer, 1992) and the Chemistry Concept Inventory (CCI; Jenkins, Birk, Bauer, Krause, & Pavelich, 2004), as well as student scores on a physics and chemistry assessment. Quantitative data is supported by teacher responses to a post workshop survey and classroom observations. Evaluation of the data shows that the STAMPS professional development workshop was successful in improving both student and teacher content knowledge. Conclusions and suggestions for future study are also included.

  3. Modeling the Impacts of Soil Organic Carbon Content of Croplands on Crop Yields in China

    Institute of Scientific and Technical Information of China (English)

    QIU Jian-jun; WANG Li-gang; LI Hu; TANG Hua-jun; LI Chang-sheng; Eric Van Ranst

    2009-01-01

    This study quantified the impacts of soil organic carbon(SOC)content on the grain yield of crops using a biogeochemical model(DNDC,denitrification-decomposition).Data on climate,soil properties,and farming management regimes of cropping systems were collected from six typical agricultural zones(northeast,north,northwest,mid-south,east and southwest regions of China,respectively)and integrated into a GIS database to support the model runs.According to the model,if the initial SOC content in the cropland was increased by 1g C kg-1,the crop yield may be increased by 176 kg ha-1 for maize in the northeast region,454 kg ha-1 for a maize-wheat rotation in the north region,328 kg ha-1 for maize in the northwest region,185 kg ha-1 for single-rice in the mid-south region,266 kg ha-1 for double-rice in east region,and 229 kg ha-1 for rice and wheat rotation in southwest region.There is a great potential for enhancing the crop yield by improving the SOC content in each region of China.

  4. PORE STRUCTURE MODEL OF CEMENT HYDRATES CONSIDERING PORE WATER CONTENT AND REACTION PROCESS UNDER ARBITRARY HUMIDITY

    Science.gov (United States)

    Fujikura, Yusuke; Oshita, Hideki

    A simulation model to estimate the pore structure of cement hydrates by curing in arbitrary relative humidity is presented. This paper describes procedures for predicting phase compositions based on the classical hydration model of Portland cement, calculating the particle size distribution of constituent phases and evaluating the pore size distribution by stereological and statistical considerations. And to estimate the water content in pore structure under any relative humidity, we proposed the simulation model of adsorption isotherm model based on the pore structure. To evaluate the effectiveness of this model, simulation results were compared with experimental results of the pore size distribution measured by mercury porosimetry. As a result, it was found that the experimental and simulated results were in close agreement, and the simulated results indicated characterization of the po re structure of cement hydrates.

  5. Trichloroethylene: Mechanistic, Epidemiologic and Other Supporting Evidence of Carcinogenic Hazard

    OpenAIRE

    Rusyn, Ivan; Chiu, Weihsueh A.; Lawrence H. Lash; Kromhout, Hans; Hansen, Johnni; Guyton, Kathryn Z.

    2013-01-01

    The chlorinated solvent trichloroethylene (TCE) is a ubiquitous environmental pollutant. The carcinogenic hazard of TCE was the subject of a 2012 evaluation by a Working Group of the International Agency for Research on Cancer (IARC). Information on exposures, relevant data from epidemiologic studies, bioassays in experimental animals, and toxicity and mechanism of action studies was used to conclude that TCE is carcinogenic to humans (Group 1). This article summarizes the key evidence formin...

  6. Biologic markers in risk assessment for environmental carcinogens

    OpenAIRE

    Perera, F.; Mayer, J.; Santella, R. M.; Brenner, D; Jeffrey, A.; Latriano, L; Smith, S.; Warburton, D; Young, T. L.; Tsai, W. Y.; Hemminki, K; Brandt-Rauf, P

    1991-01-01

    The potential of biologic markers to provide more timely and precise risk assessments for environmental carcinogens is viewed against the current state-of-the-art in biological monitoring/molecular epidemiology. Biologic markers such as carcinogen-DNA adducts and oncogene activation are currently considered valid qualitative indicators of potential risk, but for most chemical exposures research is needed to establish their validity as quantitative predictors of cancer risk. Biologic markers h...

  7. Carcinogenicity evaluations and ongoing studies: the IARC databases.

    OpenAIRE

    Vainio, H.; Coleman, M.; Wilbourn, J

    1991-01-01

    Many thousands of chemicals are produced industrially and many more occur naturally. Information on the toxicology of these chemicals is often minimal or absent. The International Agency for Research on Cancer (IARC) has published evaluations of the carcinogenic risk to humans of over 700 chemicals, groups of chemicals, and complex mixtures as a regular series of monographs. A database has been created containing summaries of all the relevant epidemiological, animal carcinogenicity, and other...

  8. Trichloroethylene: Mechanistic, epidemiologic and other supporting evidence of carcinogenic hazard.

    Science.gov (United States)

    Rusyn, Ivan; Chiu, Weihsueh A; Lash, Lawrence H; Kromhout, Hans; Hansen, Johnni; Guyton, Kathryn Z

    2014-01-01

    The chlorinated solvent trichloroethylene (TCE) is a ubiquitous environmental pollutant. The carcinogenic hazard of TCE was the subject of a 2012 evaluation by a Working Group of the International Agency for Research on Cancer (IARC). Information on exposures, relevant data from epidemiologic studies, bioassays in experimental animals, and toxicity and mechanism of action studies was used to conclude that TCE is carcinogenic to humans (Group 1). This article summarizes the key evidence forming the scientific bases for the IARC classification. Exposure to TCE from environmental sources (including hazardous waste sites and contaminated water) is common throughout the world. While workplace use of TCE has been declining, occupational exposures remain of concern, especially in developing countries. The strongest human evidence is from studies of occupational TCE exposure and kidney cancer. Positive, although less consistent, associations were reported for liver cancer and non-Hodgkin lymphoma. TCE is carcinogenic at multiple sites in multiple species and strains of experimental animals. The mechanistic evidence includes extensive data on the toxicokinetics and genotoxicity of TCE and its metabolites. Together, available evidence provided a cohesive database supporting the human cancer hazard of TCE, particularly in the kidney. For other target sites of carcinogenicity, mechanistic and other data were found to be more limited. Important sources of susceptibility to TCE toxicity and carcinogenicity were also reviewed by the Working Group. In all, consideration of the multiple evidence streams presented herein informed the IARC conclusions regarding the carcinogenicity of TCE. PMID:23973663

  9. Modeling the effects of water content on TiO2 nanoparticles transport in porous media

    Science.gov (United States)

    Toloni, Ivan; Lehmann, François; Ackerer, Philippe

    2016-08-01

    The transport of manufactured titanium dioxide (TiO2, rutile) nanoparticles (NP) in porous media was investigated by metric scale column experiments under different water saturation and ionic strength (IS) conditions. The NP breakthrough curves showed that TiO2 NP retention on the interface between air and water (AWI) and the interface between the solid and the fluid (SWI) is insignificant for an IS equal to or smaller than 3 mM KCl. For larger IS, the retention is depending on the water content and the fluid velocity. The experiments, conducted with an IS of 5 mM KCl, showed a significantly higher retention of NP than that observed under saturated conditions and very similar experimental conditions. Water flow was simulated using the standard Richards equation. The hydrodynamic model parameters for unsaturated flow were estimated through independent drainage experiments. A new mathematical model was developed to describe TiO2 NP transport and retention on SWI and AWI. The model accounts for the variation of water content and water velocity as a function of depth and takes into account the presence of the AWI and its role as a NP collector. Comparisons with experimental data showed that the suggested modeled processes can be used to quantify the NPs retentions at the AWI and SWI. The suggested model can be used for both saturated and unsaturated conditions and for a rather large range of velocities.

  10. Video Quality Prediction Models Based on Video Content Dynamics for H.264 Video over UMTS Networks

    Directory of Open Access Journals (Sweden)

    Asiya Khan

    2010-01-01

    Full Text Available The aim of this paper is to present video quality prediction models for objective non-intrusive, prediction of H.264 encoded video for all content types combining parameters both in the physical and application layer over Universal Mobile Telecommunication Systems (UMTS networks. In order to characterize the Quality of Service (QoS level, a learning model based on Adaptive Neural Fuzzy Inference System (ANFIS and a second model based on non-linear regression analysis is proposed to predict the video quality in terms of the Mean Opinion Score (MOS. The objective of the paper is two-fold. First, to find the impact of QoS parameters on end-to-end video quality for H.264 encoded video. Second, to develop learning models based on ANFIS and non-linear regression analysis to predict video quality over UMTS networks by considering the impact of radio link loss models. The loss models considered are 2-state Markov models. Both the models are trained with a combination of physical and application layer parameters and validated with unseen dataset. Preliminary results show that good prediction accuracy was obtained from both the models. The work should help in the development of a reference-free video prediction model and QoS control methods for video over UMTS networks.

  11. Evaluation of toxicogenomics approaches for assessing the risk of nongenotoxic carcinogenicity in rat liver.

    Directory of Open Access Journals (Sweden)

    Johannes Eichner

    Full Text Available The current gold-standard method for cancer safety assessment of drugs is a rodent two-year bioassay, which is associated with significant costs and requires testing a high number of animals over lifetime. Due to the absence of a comprehensive set of short-term assays predicting carcinogenicity, new approaches are currently being evaluated. One promising approach is toxicogenomics, which by virtue of genome-wide molecular profiling after compound treatment can lead to an increased mechanistic understanding, and potentially allow for the prediction of a carcinogenic potential via mathematical modeling. The latter typically involves the extraction of informative genes from omics datasets, which can be used to construct generalizable models allowing for the early classification of compounds with unknown carcinogenic potential. Here we formally describe and compare two novel methodologies for the reproducible extraction of characteristic mRNA signatures, which were employed to capture specific gene expression changes observed for nongenotoxic carcinogens. While the first method integrates multiple gene rankings, generated by diverse algorithms applied to data from different subsamplings of the training compounds, the second approach employs a statistical ratio for the identification of informative genes. Both methods were evaluated on a dataset obtained from the toxicogenomics database TG-GATEs to predict the outcome of a two-year bioassay based on profiles from 14-day treatments. Additionally, we applied our methods to datasets from previous studies and showed that the derived prediction models are on average more accurate than those built from the original signatures. The selected genes were mostly related to p53 signaling and to specific changes in anabolic processes or energy metabolism, which are typically observed in tumor cells. Among the genes most frequently incorporated into prediction models were Phlda3, Cdkn1a, Akr7a3, Ccng1 and Abcb4.

  12. STAT3 as a chemoprevention target in carcinogen-induced head and neck squamous cell carcinoma.

    OpenAIRE

    Peyser, ND; Wang, L.; Zeng, Y.; Acquafondata, M.; Freilino, ML; Li, H.; M. Sen; Gooding, WE; Satake, M; Wang, Z.; Johnson; Grandis, JR

    2016-01-01

    Head and neck squamous cell carcinoma (HNSCC) is a frequently fatal disease due in large part to a high rate of second primary tumor (SPT) formation. The 4-nitroquinoline 1-oxide (4-NQO) mouse model of oral carcinogenesis provides a robust system in which to study chemopreventive agents in the context of chemically-induced HNSCC tumors. Signal transducer and activator of transcription 3 (STAT3) is a potent oncogene that is hyperactivated by tyrosine phosphorylation early in HNSCC carcinogenes...

  13. Quantitative assessment of exposure and risk for three carcinogenics in long-standing pollution sites

    International Nuclear Information System (INIS)

    The project attempts a quantitative assessment of risks for three carcinogenics that are common in sites of long-standing pollution. Benzo(a)pyrene stands for the group of polycyclic aromatic hydrocarbons, cadmium for heavy metals, and benzene for volatile aromatic compounds. The report discusses the general fundamentals of exposure and risk assessment. The exposure model is described in detail and applied to the three test substances. (orig./MG)

  14. Induction of active melanocytes in mouse skin by carcinogens: a new method for detection of skin carcinogens.

    Science.gov (United States)

    Iwata, K; Inui, N; Takeuchi, T

    1981-01-01

    Application of potent skin carcinogens, such as 7,12-dimethylbenz[a]anthracene, 3-methylcholanthrene, benzo[a]pyrene and 4-nitroquinoline-1-oxide, induced numerous dihydroxyphenylalanine (dopa)-positive cells in the interfollicular epidermis of C57BL/6 mice in a dose- and time-dependent fashion. Chrysene, a weak skin carcinogen, and croton oil, a tumor promoter, also induced 3--4 times more dopa-positive cells than acetone. Liver carcinogens, such as 3'-methyl-4-dimethylaminoazobenzene and N-2-acetylaminofluorene, and non-carcinogenic aromatic hydrocarbons, such as anthracene, fluoranthene, fluorene and pyrene, did not induce increase in these cells. These results indicate that increase in the number of dopa-positive cells after application of chemicals is well correlated with the abilities of these compounds to induce skin carcinogenesis and suppress sebaceous glands. PMID:7273337

  15. A Model for Semi-Automatic Composition of Educational Content from Open Repositories of Learning Objects

    Directory of Open Access Journals (Sweden)

    Paula Andrea Rodríguez Marín

    2014-04-01

    Full Text Available Learning objects (LOs repositories are important in building educational content and should allow search, retrieval and composition processes to be successfully developed to reach educational goals. However, such processes require so much time-consuming and not always provide the desired results. Thus, the aim of this paper is to propose a model for the semiautomatic composition of LOs, which are automatically recovered from open repositories. For the development of model, various text similarity measures are discussed, while for calibration and validation some comparison experiments were performed using the results obtained by teachers. Experimental results show that when using a value of k (number of LOs selected of at least 3, the percentage of similarities between the model and such made by experts exceeds 75%. To conclude, it can be established that the model proposed allows teachers to save time and effort for LOs selection by performing a pre-filter process.

  16. Review Content Analytics for the Prediction of Learner’s Feedback with Multivariate Regression Model

    Directory of Open Access Journals (Sweden)

    T. Chellatamilan

    2015-06-01

    Full Text Available E-learning facilitates both synchronous and asynchronous learning and it plays very important role in the teaching learning process. A large group of learners are engaged in the idea exchange independently by interacting with the members present in the learning management system. In order to generate meaningful learning outcome of the individual peer learners, the feedback review is very essential to extract the conceptual content which reflect the instantaneous learner’s behavior, emotions, capabilities, interestingness and difficulties and to fits them effectively. Collecting feedback in the form of numeric scale is very tough for both the learners and facilitators while specifying the rating, but it is too easy for the learners provide feedback in the form of text messages. The key challenge for analyzers is to extract the meaningful feedback content and dynamic rating of the learner’s feedback related to various conceptual contexts. We propose a novel method using multivariate predictive model for conceptual content analytics based on e-learners reviews using standard statistical model inverse regression. Finally the analysis is used in the prediction studies and to illustrate their effectiveness against the learner’s feedback.

  17. Level Decreasing Kinetics Model of Heavy Metal Contents in the Coal Stockpile Wastewater with Electrocoagulation

    Directory of Open Access Journals (Sweden)

    Rusdianasari Rusdianasari

    2015-01-01

    Full Text Available Electrocoagulation is one of methods used to treat wastewater in the coal stockpile without using coagulants. Characteristics of wastewater observed are heavy metals (Fe and Mn and pH.  The decrease in the heavy metals content and the increase in the pH of this wastewater treatment process will then be proposed in the adsorption kinetics model. The influence of  variations in currents and processing time were observed. The time variation of the adsorption process were 60 to 120 minutes with current variations from 1.3 to 3.0 Ampere at a fixed 12 voltages. The results obtained that the Fe content could be decreased to 0.03 ppm at 90 minutes while the content of Mn was decreased to 0.01 ppm at the same time. The increase in pH (7.11 was achieved when applying 2.5 A current at 90 minutes process time. The results obtained from the electrocoagulation method was then proposed in the model of the Langmuir isotherm adsorption kinetics and Freundlich isotherm.

  18. Two azole fungicides (carcinogenic triadimefon and non-carcinogenic myclobutanil) exhibit different hepatic cytochrome P450 activities in medaka fish

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chun-Hung [Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan (China); Chou, Pei-Hsin [Department of Environmental Engineering, National Cheng-Kung University, Tainan, Taiwan (China); Chen, Pei-Jen, E-mail: chenpj@ntu.edu.tw [Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan (China)

    2014-07-30

    Highlights: • We assess ecotoxicological impact of azole fungicides in the aquatic environment. • Carcinogenic and non-carcinogenic azoles show different CYP activities in medaka. • We compare azole-induced CYP expression and carcinogenesis between fish and rodents. • Liver CYP-enzyme induction is a key event in conazole-induced tumorigenesis. • We suggest toxicity evaluation methods for azole fungicides using medaka fish. - Abstract: Conazoles are a class of imidazole- or triazole-containing drugs commonly used as fungicides in agriculture and medicine. The broad application of azole drugs has led to the contamination of surface aquifers receiving the effluent of municipal or hospital wastewater or agricultural runoff. Several triazoles are rodent carcinogens; azole pollution is a concern to environmental safety and human health. However, the carcinogenic mechanisms associated with cytochrome P450 enzymes (CYPs) of conazoles remain unclear. We exposed adult medaka fish (Oryzias latipes) to continuous aqueous solutions of carcinogenic triadimefon and non-carcinogenic myclobutanil for 7 to 20 days at sub-lethal or environmentally relevant concentrations and assessed hepatic CYP activity and gene expression associated with CYP-mediated toxicity. Both triadimefon and myclobutanil induced hepatic CYP3A activity, but only triadimefon enhanced CYP1A activity. The gene expression of cyp3a38, cyp3a40, pregnane x receptor (pxr), cyp26b, retinoid acid receptor γ1 (rarγ1) and p53 was higher with triadimefon than myclobutanil. As well, yeast-based reporter gene assay revealed that 4 tested conazoles were weak agonists of aryl hydrocarbon receptor (AhR). We reveal differential CYP gene expression with carcinogenic and non-carcinogenic conazoles in a lower vertebrate, medaka fish. Liver CYP-enzyme induction may be a key event in conazole-induced tumorigenesis. This information is essential to evaluate the potential threat of conazoles to human health and fish

  19. Two azole fungicides (carcinogenic triadimefon and non-carcinogenic myclobutanil) exhibit different hepatic cytochrome P450 activities in medaka fish

    International Nuclear Information System (INIS)

    Highlights: • We assess ecotoxicological impact of azole fungicides in the aquatic environment. • Carcinogenic and non-carcinogenic azoles show different CYP activities in medaka. • We compare azole-induced CYP expression and carcinogenesis between fish and rodents. • Liver CYP-enzyme induction is a key event in conazole-induced tumorigenesis. • We suggest toxicity evaluation methods for azole fungicides using medaka fish. - Abstract: Conazoles are a class of imidazole- or triazole-containing drugs commonly used as fungicides in agriculture and medicine. The broad application of azole drugs has led to the contamination of surface aquifers receiving the effluent of municipal or hospital wastewater or agricultural runoff. Several triazoles are rodent carcinogens; azole pollution is a concern to environmental safety and human health. However, the carcinogenic mechanisms associated with cytochrome P450 enzymes (CYPs) of conazoles remain unclear. We exposed adult medaka fish (Oryzias latipes) to continuous aqueous solutions of carcinogenic triadimefon and non-carcinogenic myclobutanil for 7 to 20 days at sub-lethal or environmentally relevant concentrations and assessed hepatic CYP activity and gene expression associated with CYP-mediated toxicity. Both triadimefon and myclobutanil induced hepatic CYP3A activity, but only triadimefon enhanced CYP1A activity. The gene expression of cyp3a38, cyp3a40, pregnane x receptor (pxr), cyp26b, retinoid acid receptor γ1 (rarγ1) and p53 was higher with triadimefon than myclobutanil. As well, yeast-based reporter gene assay revealed that 4 tested conazoles were weak agonists of aryl hydrocarbon receptor (AhR). We reveal differential CYP gene expression with carcinogenic and non-carcinogenic conazoles in a lower vertebrate, medaka fish. Liver CYP-enzyme induction may be a key event in conazole-induced tumorigenesis. This information is essential to evaluate the potential threat of conazoles to human health and fish

  20. Two azole fungicides (carcinogenic triadimefon and non-carcinogenic myclobutanil) exhibit different hepatic cytochrome P450 activities in medaka fish.

    Science.gov (United States)

    Lin, Chun-Hung; Chou, Pei-Hsin; Chen, Pei-Jen

    2014-07-30

    Conazoles are a class of imidazole- or triazole-containing drugs commonly used as fungicides in agriculture and medicine. The broad application of azole drugs has led to the contamination of surface aquifers receiving the effluent of municipal or hospital wastewater or agricultural runoff. Several triazoles are rodent carcinogens; azole pollution is a concern to environmental safety and human health. However, the carcinogenic mechanisms associated with cytochrome P450 enzymes (CYPs) of conazoles remain unclear. We exposed adult medaka fish (Oryzias latipes) to continuous aqueous solutions of carcinogenic triadimefon and non-carcinogenic myclobutanil for 7 to 20 days at sub-lethal or environmentally relevant concentrations and assessed hepatic CYP activity and gene expression associated with CYP-mediated toxicity. Both triadimefon and myclobutanil induced hepatic CYP3A activity, but only triadimefon enhanced CYP1A activity. The gene expression of cyp3a38, cyp3a40, pregnane x receptor (pxr), cyp26b, retinoid acid receptor γ1 (rarγ1) and p53 was higher with triadimefon than myclobutanil. As well, yeast-based reporter gene assay revealed that 4 tested conazoles were weak agonists of aryl hydrocarbon receptor (AhR). We reveal differential CYP gene expression with carcinogenic and non-carcinogenic conazoles in a lower vertebrate, medaka fish. Liver CYP-enzyme induction may be a key event in conazole-induced tumorigenesis. This information is essential to evaluate the potential threat of conazoles to human health and fish populations in the aquatic environment. PMID:24962053

  1. Modeling compositional dynamics based on GC and purine contents of protein-coding sequences

    Directory of Open Access Journals (Sweden)

    Yu Jun

    2010-11-01

    Full Text Available Abstract Background Understanding the compositional dynamics of genomes and their coding sequences is of great significance in gaining clues into molecular evolution and a large number of publically-available genome sequences have allowed us to quantitatively predict deviations of empirical data from their theoretical counterparts. However, the quantification of theoretical compositional variations for a wide diversity of genomes remains a major challenge. Results To model the compositional dynamics of protein-coding sequences, we propose two simple models that take into account both mutation and selection effects, which act differently at the three codon positions, and use both GC and purine contents as compositional parameters. The two models concern the theoretical composition of nucleotides, codons, and amino acids, with no prerequisite of homologous sequences or their alignments. We evaluated the two models by quantifying theoretical compositions of a large collection of protein-coding sequences (including 46 of Archaea, 686 of Bacteria, and 826 of Eukarya, yielding consistent theoretical compositions across all the collected sequences. Conclusions We show that the compositions of nucleotides, codons, and amino acids are largely determined by both GC and purine contents and suggest that deviations of the observed from the expected compositions may reflect compositional signatures that arise from a complex interplay between mutation and selection via DNA replication and repair mechanisms. Reviewers This article was reviewed by Zhaolei Zhang (nominated by Mark Gerstein, Guruprasad Ananda (nominated by Kateryna Makova, and Daniel Haft.

  2. Modeling compositional dynamics based on GC and purine contents of protein-coding sequences

    KAUST Repository

    Zhang, Zhang

    2010-11-08

    Background: Understanding the compositional dynamics of genomes and their coding sequences is of great significance in gaining clues into molecular evolution and a large number of publically-available genome sequences have allowed us to quantitatively predict deviations of empirical data from their theoretical counterparts. However, the quantification of theoretical compositional variations for a wide diversity of genomes remains a major challenge.Results: To model the compositional dynamics of protein-coding sequences, we propose two simple models that take into account both mutation and selection effects, which act differently at the three codon positions, and use both GC and purine contents as compositional parameters. The two models concern the theoretical composition of nucleotides, codons, and amino acids, with no prerequisite of homologous sequences or their alignments. We evaluated the two models by quantifying theoretical compositions of a large collection of protein-coding sequences (including 46 of Archaea, 686 of Bacteria, and 826 of Eukarya), yielding consistent theoretical compositions across all the collected sequences.Conclusions: We show that the compositions of nucleotides, codons, and amino acids are largely determined by both GC and purine contents and suggest that deviations of the observed from the expected compositions may reflect compositional signatures that arise from a complex interplay between mutation and selection via DNA replication and repair mechanisms.Reviewers: This article was reviewed by Zhaolei Zhang (nominated by Mark Gerstein), Guruprasad Ananda (nominated by Kateryna Makova), and Daniel Haft. 2010 Zhang and Yu; licensee BioMed Central Ltd.

  3. High-content chemical and RNAi screens for suppressors of neurotoxicity in a Huntington's disease model.

    Directory of Open Access Journals (Sweden)

    Joost Schulte

    Full Text Available To identify Huntington's Disease therapeutics, we conducted high-content small molecule and RNAi suppressor screens using a Drosophila primary neural culture Huntingtin model. Drosophila primary neurons offer a sensitive readout for neurotoxicty, as their neurites develop dysmorphic features in the presence of mutant polyglutamine-expanded Huntingtin compared to nonpathogenic Huntingtin. By tracking the subcellular distribution of mRFP-tagged pathogenic Huntingtin and assaying neurite branch morphology via live-imaging, we identified suppressors that could reduce Huntingtin aggregation and/or prevent the formation of dystrophic neurites. The custom algorithms we used to quantify neurite morphologies in complex cultures provide a useful tool for future high-content screening approaches focused on neurodegenerative disease models. Compounds previously found to be effective aggregation inhibitors in mammalian systems were also effective in Drosophila primary cultures, suggesting translational capacity between these models. However, we did not observe a direct correlation between the ability of a compound or gene knockdown to suppress aggregate formation and its ability to rescue dysmorphic neurites. Only a subset of aggregation inhibitors could revert dysmorphic cellular profiles. We identified lkb1, an upstream kinase in the mTOR/Insulin pathway, and four novel drugs, Camptothecin, OH-Camptothecin, 18β-Glycyrrhetinic acid, and Carbenoxolone, that were strong suppressors of mutant Huntingtin-induced neurotoxicity. Huntingtin neurotoxicity suppressors identified through our screen also restored viability in an in vivo Drosophila Huntington's Disease model, making them attractive candidates for further therapeutic evaluation.

  4. Carcinogen-specific mutations in preferred Ras-Raf pathway oncogenes directed by strand bias.

    Science.gov (United States)

    Keller, Ross R; Gestl, Shelley A; Lu, Amy Q; Hoke, Alicia; Feith, David J; Gunther, Edward J

    2016-08-01

    Carcinogen exposures inscribe mutation patterns on cancer genomes and sometimes bias the acquisition of driver mutations toward preferred oncogenes, potentially dictating sensitivity to targeted agents. Whether and how carcinogen-specific mutation patterns direct activation of preferred oncogenes remains poorly understood. Here, mouse models of breast cancer were exploited to uncover a mechanistic link between strand-biased mutagenesis and oncogene preference. When chemical carcinogens were employed during Wnt1-initiated mammary tumorigenesis, exposure to either 7,12-dimethylbenz(a)anthracene (DMBA) or N-ethyl-N-nitrosourea (ENU) dramatically accelerated tumor onset. Mammary tumors that followed DMBA exposure nearly always activated the Ras pathway via somatic Hras(CAA61CTA) mutations. Surprisingly, mammary tumors that followed ENU exposure typically lacked Hras mutations, and instead activated the Ras pathway downstream via Braf(GTG636GAG) mutations. Hras(CAA61CTA) mutations involve an A-to-T change on the sense strand, whereas Braf(GTG636GAG) mutations involve an inverse T-to-A change, suggesting that strand-biased mutagenesis may determine oncogene preference. To examine this possibility further, we turned to an alternative Wnt-driven tumor model in which carcinogen exposures augment a latent mammary tumor predisposition in Apc(min) mice. DMBA and ENU each accelerated mammary tumor onset in Apc(min) mice by introducing somatic, "second-hit" Apc mutations. Consistent with our strand bias model, DMBA and ENU generated strikingly distinct Apc mutation patterns, including stringently strand-inverse mutation signatures at A:T sites. Crucially, these contrasting signatures precisely match those proposed to confer bias toward Hras(CAA61CTA) versus Braf(GTG636GAG) mutations in the original tumor sets. Our findings highlight a novel mechanism whereby exposure history acts through strand-biased mutagenesis to specify activation of preferred oncogenes. PMID:27207659

  5. Land management of bracken needs to account for bracken carcinogens - a case study from Britain

    DEFF Research Database (Denmark)

    Rasmussen, Lars Holm; Donnelly, Eric; Strobel, Bjarne W.;

    2015-01-01

    Bracken ferns are some of the most widespread ferns in the World causing immense problems for land managers, foresters and rangers. Bracken is suspected of causing cancer in Humans due to its content of the carcinogen ptaquiloside. Ingestion of bracken, or food and drinking water contaminated with...... ptaquiloside may be the cause. The aim of this study was to monitor the content of ptaquiloside in 20 bracken stands from Britain to obtain a better understanding of the ptaquiloside dynamics and to evaluate the environmental implications of using different cutting regimes in bracken management. The...... in bracken stands at any given time is difficult to predict and did not show any correlations with edaphic growth factors. The content of ptaquiloside turned out to be higher in fronds emerging after cutting compared to uncut fronds. Environmental risk assessment and bracken management must therefore...

  6. Content-based similarity for 3D model retrieval and classification

    Institute of Scientific and Technical Information of China (English)

    Ke Lü; Ning He; Jian Xue

    2009-01-01

    With the rapid development of 3D digital shape information,content-based 3D model retrieval and classification has become an important research area.This paper presents a novel 3D model retrieval and classification algorithm.For feature representation,a method combining a distance histogram and moment invariants is proposed to improve the retrieval performance.The major advantage of using a distance histogram is its invariance to the transforms of scaling,translation and rotation.Based on the premise that two similar objects should have high mutual information,the querying of 3D data should convey a great deal of information on the shape of the two objects,and so we propose a mutual information distance measurement to perform the similarity comparison of 3D objects.The proposed algorithm is tested with a 3D model retrieval and classification prototype,and the experimental evaluation demonstrates satisfactory retrieval results and classification accuracy.

  7. Human Inspired Self-developmental Model of Neural Network (HIM): Introducing Content/Form Computing

    Science.gov (United States)

    Krajíček, Jiří

    This paper presents cross-disciplinary research between medical/psychological evidence on human abilities and informatics needs to update current models in computer science to support alternative methods for computation and communication. In [10] we have already proposed hypothesis introducing concept of human information model (HIM) as cooperative system. Here we continue on HIM design in detail. In our design, first we introduce Content/Form computing system which is new principle of present methods in evolutionary computing (genetic algorithms, genetic programming). Then we apply this system on HIM (type of artificial neural network) model as basic network self-developmental paradigm. Main inspiration of our natural/human design comes from well known concept of artificial neural networks, medical/psychological evidence and Sheldrake theory of "Nature as Alive" [22].

  8. Chemomodulation of carcinogen metabolising enzymes, antioxidant profiles and skin and forestomach papillomagenesis by Spirulina platensis.

    Science.gov (United States)

    Dasgupta, T; Banejee, S; Yadav, P K; Rao, A R

    2001-10-01

    Numerous reports have revealed an inverse association between consumption of some selective natural products and risk of developing cancer. In the present study the effect of 250 and 500 mg/kg body wt. of Spirulina was examined on drug metabolising phase I and phase II enzymes, antioxidant enzymes, glutathione content, lactate dehydrogenase and lipid peroxidation in the liver of 7-week-old Swiss albino mice. The implications of these biochemical alterations have been further evaluated adopting the protocol of benzo(a)pyrene induced forestomach and 7,12 dimethylbenz(a)anthracene (DMBA) initiated and croton oil promoted skin papillomagenesis. Our primary findings reveal the 'Monofunctional' nature of Spirulina as deduced from its potential to induce only the phase II enzyme activities associated mainly with carcinogen detoxification. The glutathione S-transferase and DT-diaphorase specific activities were induced in hepatic and all the extrahepatic organs examined (lung, kidney and forestomach) by Spirulina pretreatment (significance level being from p < 0.05 to p < 0.005) except for the low dose treatment in forestomach. With reference to antioxidant enzymes viz., superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and reduced glutathione were increased significantly by both the chosen doses of Spirulina from p < 0.01 to p < 0.005. Chemopreventive response was quantitated by the average number of papillomas per effective mouse (tumor burden) as well as percentage of tumor bearing animals. There was a significant inhibition of tumor burden as well as tumor incidence in both the tumor model systems studied. In the skin tumor studies tumor burden was reduced from 4.86 to 1.20 and 1.15 by the low and high dose treatment respectively. In stomach tumor studies tumor burden was 2.05 and 1.73 by the low and high doses of Spirulina treatment against 3.73 that of control. PMID:11768236

  9. Peer-to-Peer Video Conferencing Using Hybrid Content Distribution Model

    Directory of Open Access Journals (Sweden)

    Imad Jasim

    2012-01-01

    Full Text Available Problem statement: Multimedia Conferencing System (MCS is a server-based video conferencing system. One of the most critical limitations faced by this approach is the scalability issue. In the MCS, the outgoing bandwidth of the server is shared among all concurrent clients. Thus, the more clients there are, the lesser the bandwidth each client can have. The performance of this approach therefore deteriorates rapidly as the number of simultaneous clients increases. In addition, a pure server-based solution is expensive. Approach: In this research, the server-based infrastructure is modified into a peer-to-peer video conferencing system while preserving the same functionality and features of the existing MCS. This modification can be achieved using a hybrid content distribution model, which is a combination of fluid and chunk content distribution models to distribute parts of the video stream fairly among participants. The hybrid content distribution model offers a better way of handling heterogeneous networks because it can distinguish between a fast peer and a slow peer, dealing with each one according to its capabilities. Results: In our proposed system, the function server will not be used for video distribution. Instead, it will only be used for monitoring and controlling the peers to reduce the burden on the servers. Experimental results conducted in the nation advanced IPv6 center as a real environment and live conferencing. Conclusion: This will lead to overcome the problem of scalability and a bandwidth bottleneck on the main server and achieve good way to distribute video chunks.

  10. Multiple Adaptations and Content-Adaptive FEC Using Parameterized RD Model for Embedded Wavelet Video

    Science.gov (United States)

    Yu, Ya-Huei; Ho, Chien-Peng; Tsai, Chun-Jen

    2007-12-01

    Scalable video coding (SVC) has been an active research topic for the past decade. In the past, most SVC technologies were based on a coarse-granularity scalable model which puts many scalability constraints on the encoded bitstreams. As a result, the application scenario of adapting a preencoded bitstream multiple times along the distribution chain has not been seriously investigated before. In this paper, a model-based multiple-adaptation framework based on a wavelet video codec, MC-EZBC, is proposed. The proposed technology allows multiple adaptations on both the video data and the content-adaptive FEC protection codes. For multiple adaptations of video data, rate-distortion information must be embedded within the video bitstream in order to allow rate-distortion optimized operations for each adaptation. Experimental results show that the proposed method reduces the amount of side information by more than 50% on average when compared to the existing technique. It also reduces the number of iterations required to perform the tier-2 entropy coding by more than 64% on average. In addition, due to the nondiscrete nature of the rate-distortion model, the proposed framework also enables multiple adaptations of content-adaptive FEC protection scheme for more flexible error-resilient transmission of bitstreams.

  11. Mechanism-Based Classification of PAH Mixtures to Predict Carcinogenic Potential.

    Science.gov (United States)

    Tilton, Susan C; Siddens, Lisbeth K; Krueger, Sharon K; Larkin, Andrew J; Löhr, Christiane V; Williams, David E; Baird, William M; Waters, Katrina M

    2015-07-01

    We have previously shown that relative potency factors and DNA adduct measurements are inadequate for predicting carcinogenicity of certain polycyclic aromatic hydrocarbons (PAHs) and PAH mixtures, particularly those that function through alternate pathways or exhibit greater promotional activity compared to benzo[a]pyrene (BaP). Therefore, we developed a pathway-based approach for classification of tumor outcome after dermal exposure to PAH/mixtures. FVB/N mice were exposed to dibenzo[def,p]chrysene (DBC), BaP, or environmental PAH mixtures (Mix 1-3) following a 2-stage initiation/promotion skin tumor protocol. Resulting tumor incidence could be categorized by carcinogenic potency as DBC > BaP = Mix2 = Mix3 > Mix1 = Control, based on statistical significance. Gene expression profiles measured in skin of mice collected 12 h post-initiation were compared with tumor outcome for identification of short-term bioactivity profiles. A Bayesian integration model was utilized to identify biological pathways predictive of PAH carcinogenic potential during initiation. Integration of probability matrices from four enriched pathways (P < .05) for DNA damage, apoptosis, response to chemical stimulus, and interferon gamma signaling resulted in the highest classification accuracy with leave-one-out cross validation. This pathway-driven approach was successfully utilized to distinguish early regulatory events during initiation prognostic for tumor outcome and provides proof-of-concept for using short-term initiation studies to classify carcinogenic potential of environmental PAH mixtures. These data further provide a 'source-to-outcome' model that could be used to predict PAH interactions during tumorigenesis and provide an example of how mode-of-action-based risk assessment could be employed for environmental PAH mixtures. PMID:25908611

  12. Research on the Estimation Model of Soil Moisture Content Based on the Characteristics of Thermal Infrared Data

    OpenAIRE

    Xu, Jun; Jiang, Jianjun

    2013-01-01

    With the portable Fourier Transform Infrared Spectroscopy (FTIR), the reflectance spectra of soil samples with different moisture content are measured in laboratory for expounding the characteristic of radiation in the thermal infrared part of the spectrum with different soil moisture content. A model of estimating the moisture content in soil is attempted to make based on Moisture Diagnostic Index (MDI). In general,the spectral characteristic of soil emissivity in laboratory includes the f...

  13. Comparison of in vivo genotoxic and carcinogenic potency to augment mode of action analysis: Case study with hexavalent chromium.

    Science.gov (United States)

    Thompson, Chad M; Bichteler, Anne; Rager, Julia E; Suh, Mina; Proctor, Deborah M; Haws, Laurie C; Harris, Mark A

    2016-04-01

    Recent analyses-highlighted by the International Workshops on Genotoxicity Testing Working Group on Quantitative Approaches to Genetic Toxicology Risk Assessment-have identified a correlation between (log) estimates of a carcinogen's in vivo genotoxic potency and in vivo carcinogenic potency in typical laboratory animal models, even when the underlying data have not been matched for tissue, species, or strain. Such a correlation could have important implications for risk assessment, including informing the mode of action (MOA) of specific carcinogens. When in vivo genotoxic potency is weak relative to carcinogenic potency, MOAs other than genotoxicity (e.g., endocrine disruption or regenerative hyperplasia) may be operational. Herein, we review recent in vivo genotoxicity and carcinogenicity data for hexavalent chromium (Cr(VI)), following oral ingestion, in relevant tissues and species in the context of the aforementioned correlation. Potency estimates were generated using benchmark doses, or no-observable-adverse-effect-levels when data were not amenable to dose-response modeling. While the ratio between log values for carcinogenic and genotoxic potency was ≥1 for many compounds, the ratios for several Cr(VI) datasets (including in target tissue) were less than unity. In fact, the ratios for Cr(VI) clustered closely with ratios for chloroform and diethanolamine, two chemicals posited to have non-genotoxic MOAs. These findings suggest that genotoxicity may not play a major role in the cancers observed in rodents following exposure to high concentrations of Cr(VI) in drinking water-a finding consistent with recent MOA and adverse outcome pathway (AOP) analyses concerning Cr(VI). This semi-quantitative analysis, therefore, may be useful to augment traditional MOA and AOP analyses. More case examples will be needed to further explore the general applicability and validity of this approach for human health risk assessment. PMID:27085472

  14. High content analysis of an in vitro model for metabolic toxicity: results with the model toxicants 4-aminophenol and cyclophosphamide.

    Science.gov (United States)

    Cole, Stephanie D; Madren-Whalley, Janna S; Li, Albert P; Dorsey, Russell; Salem, Harry

    2014-12-01

    In vitro models that accurately and rapidly assess hepatotoxicity and the effects of hepatic metabolism on nonliver cell types are needed by the U.S. Department of Defense and the pharmaceutical industry to screen compound libraries. Here, we report the first use of high content analysis on the Integrated Discrete Multiple Organ Co-Culture (IdMOC) system, a high-throughput method for such studies. We cultured 3T3-L1 cells in the presence and absence of primary human hepatocytes, and exposed the cultures to 4-aminophenol and cyclophosphamide, model toxicants that are respectively detoxified and activated by the liver. Following staining with calcein-AM, ethidium homodimer-1, and Hoechst 33342, high content analysis of the cultures revealed four cytotoxic endpoints: fluorescence intensities of calcein-AM and ethidium homodimer-1, nuclear area, and cell density. Using these endpoints, we observed that the cytotoxicity of 4-aminophenol in 3T3-L1 cells in co-culture was less than that observed for 3T3-L1 monocultures, consistent with the known detoxification of 4-aminophenol by hepatocytes. Conversely, cyclophosphamide cytotoxicity for 3T3-L1 cells was enhanced by co-culturing with hepatocytes, consistent with the known metabolic activation of this toxicant. The use of IdMOC plates combined with high content analysis is therefore a multi-endpoint, high-throughput capability for measuring the effects of metabolism on toxicity. PMID:25239051

  15. Food Additives of Public Concern for their Carcinogenicity

    Directory of Open Access Journals (Sweden)

    Fatih Gultekin

    2015-08-01

    Full Text Available No-Observed-Adverse Effect Level (NOAEL of food additives has been long determined on the basis of toxicological studies. Acceptable Daily Intake (ADI levels of food additives for human are derived from these NOAEL, and their legal limits are then established for the food products, intentionally added with food additives. However, recent studies demonstrated that consumption of some processed food containing certain food additives might have increased the risk of cancer in human although the legal limits of these additives in processed foods are well respected by the manufacturers. Possible reasons for increased carcinogenicity risk in processed foods containing these additives can be due to various factors: -interaction of additives with some food ingredients, -food processing may change the chemical formula of food additive to a formula to be acting similarly as carcinogenic compound, -a negative synergistic effects when combined with other additives, -improper storage conditions, and -unknown carcinogenic by-products occurring during the food processing. Due to the above mentioned factors we recommend that an additive, intentionally added to the food during processing must be traced officially for its carcinogenicity. In this review, we overviewed all of the food additives authorized in European Union. Therefore, the traceability issues of processed foods containing certain food additives, which have a negligible probability of carcinogenicity in legal limits, must be reinforced in the perspective of public health concerns.

  16. Development of Experienced Science Teachers' Pedagogical Content Knowledge of Models of the Solar System and the Universe

    Science.gov (United States)

    Henze, Ineke; van Driel, Jan H.; Verloop, Nico

    2008-01-01

    This paper investigates the developing pedagogical content knowledge (PCK) of nine experienced science teachers in their first few years of teaching a new science syllabus in the Dutch secondary education system. We aimed to identify the content and structure of the PCK for a specific topic in the new syllabus, "Models of the Solar System and the…

  17. A METHODOLOGICAL MODEL FOR INTEGRATING CHARACTER WITHIN CONTENT AND LANGUAGE INTEGRATED LEARNING IN SOCIOLOGY OF RELIGION

    Directory of Open Access Journals (Sweden)

    Moh Yasir Alimi

    2013-01-01

    Full Text Available In this article, I describe a methodological model I used in a experimental study on how to integrate character within the practice of Content and Language Integrated Learning (CLIL at the higher education Indonesia.This research can be added to research about character education and CLIL in tertiary education, giving nuances to the practice of CLIL so far predominantly a practice in primary and secondary schools.The research was conducted in Semarang State University, in the Department of Sociology and Anthropology, in Sociology of Religion bilingual class. The research indicates that the integration of character within CLIL enrich the perspective of CLIL by strengthening the use of CLIL for intellectual growth and moral development. On the other side, the use of CLIL with character education gives methods and perspectives to the practice of character education so far which so far only emphasise contents reforms without learning methods reforms. The research also reveals that the weakness of CLIL in using text for classroom learning can be overcome bythe use ofspecific reading and writing strategies. I develop a practical text strategy which can be effectively used in highly conceptual subject such as sociology of religion. Artikel ini bertujuan untuk mendeskripsikan model metodologis yang saya pakai untuk mengintegrasikannya karakter dalam Content and Language Integrated Learning (CLIL pada pendidikan tinggi di Indonesia. Penelitian ini memperkaya penelitian mengenai pendidikan karakter dan penerapan CLIL di perguruan tinggi, selama ini penelitian semacam itu hanya biasa di level lebih rendah. Penelitian dilakukan di Universitas Negeri Semarang, pada kelas bilingual yang diikuti 25 mahasiswa, dan diujikan pada mata kuliah Sosiologi Agama. Pelajaran dari penelitian ini adalah integrasi karakter dalam CLIL dapat memperkaya CLIL. Sebaliknya penggunaan CLIL untuk mendidikkan karakter di kelas bilingual mampu menjawab berbagai tantangan pendidikan

  18. [Research on Resistant Starch Content of Rice Grain Based on NIR Spectroscopy Model].

    Science.gov (United States)

    Luo, Xi; Wu, Fang-xi; Xie, Hong-guang; Zhu, Yong-sheng; Zhang, Jian-fu; Xie, Hua-an

    2016-03-01

    A new method based on near-infrared reflectance spectroscopy (NIRS) analysis was explored to determine the content of rice-resistant starch instead of common chemical method which took long time was high-cost. First of all, we collected 62 spectral data which have big differences in terms of resistant starch content of rice, and then the spectral data and detected chemical values are imported chemometrics software. After that a near-infrared spectroscopy calibration model for rice-resistant starch content was constructed with partial least squares (PLS) method. Results are as follows: In respect of internal cross validation, the coefficient of determination (R2) of untreated, pretreatment with MSC+1thD, pretreatment with 1thD+SNV were 0.920 2, 0.967 0 and 0.976 7 respectively. Root mean square error of prediction (RMSEP) were 1.533 7, 1.011 2 and 0.837 1 respectively. In respect of external validation, the coefficient of determination (R2) of untreated, pretreatment with MSC+ 1thD, pretreatment with 1thD+SNV were 0.805, 0.976 and 0.992 respectively. The average absolute error was 1.456, 0.818, 0.515 respectively. There was no significant difference between chemical and predicted values (Turkey multiple comparison), so we think near infrared spectrum analysis is more feasible than chemical measurement. Among the different pretreatment, the first derivation and standard normal variate (1thD+SNV) have higher coefficient of determination (R2) and lower error value whether in internal validation and external validation. In other words, the calibration model has higher precision and less error by pretreatment with 1thD+SNV. PMID:27400508

  19. Hepatic content of collagens and laminin in rat model of experimental liverfibrosis

    Institute of Scientific and Technical Information of China (English)

    Ying De Wang; Le Wei Jia; Chun Mei Li

    2000-01-01

    AIM The hepatic content of collagens (type I, Ⅲ and Ⅶ) and laminin (LN) in rat model of experimentalliver fibrosis was observed to find out their roles in the pathogenesis of liver fibrosis.METHODS The experimental rat model was established by immunological injury induced by injectinghuman albumin. Histopathological and immunohistochemical methods were used to measure the hepaticcontent of collagens and laminin in the fibrotic rat livers.RESULTS The hepatic contents of collagens (type I, Ⅲ, Ⅶ) and LN in the fibrotic rat livers weresignificantly increased as compared with those in the control group, and they were found to be mainlylocalized in the portal space, central veins and fibrous septa. Electron microscopic study showed that pro-collagens were present around the “activated” hepatic stellate cells (HSC) and the hepatocytes atrophied.CONCLUSION Pathological deposition of collagens (type Ⅰ, Ⅲ and Ⅶ ) and laminin was the fundamentallesion of liver fibrosis. HSC may be the major cellular source of collagens (type Ⅰ, Ⅲ and Ⅶ) and laminin inthe liver tissue.

  20. Carcinogenic potential of hydrotreated petroleum aromatic extracts.

    OpenAIRE

    Doak, S. M.; Hend, R W; van der Wiel, A; Hunt, P F

    1985-01-01

    Five experimental petroleum extracts were produced from luboil distillates derived from Middle East paraffinic crude by solvent extraction and severe hydrotreatment. The polycyclic aromatic content (PCA) of the extracts was determined by dimethyl sulphoxide extraction and ranged from 3.7-9.2% w/w. The five extracts were evaluated for their potential to induce cutaneous and systemic neoplasia in female mice derived from Carworth Farm No 1 strain (CF1). The test substances were applied undilute...

  1. QoS-based Objects Replica Placement among Peering Content Distribution Networks in a Virtual Organization Model

    Directory of Open Access Journals (Sweden)

    Adenike O Osofisan

    2011-03-01

    Full Text Available The Internet has experienced a phenomenal growth as a result of increasing demands for contents, content distributions and other services. CDNs have evolved as cooperative and collaborative groups of networks over the Internet where contents are replicated over the surrogate servers for efficient delivery performance to the clients and improved service cost to the CDN providers. However, a CDN is limited in terms of Point of Presence (PoP and scalability. This work is concerned with content object replication among peering CDNs. It provides an analytical model for the replication problem in terms of a constrained optimization problem subject to a mix of QoS

  2. How to Build a Course in Mathematical–Biological Modeling: Content and Processes for Knowledge and Skill

    OpenAIRE

    Hoskinson, Anne-Marie

    2010-01-01

    Biological problems in the twenty-first century are complex and require mathematical insight, often resulting in mathematical models of biological systems. Building mathematical–biological models requires cooperation among biologists and mathematicians, and mastery of building models. A new course in mathematical modeling presented the opportunity to build both content and process learning of mathematical models, the modeling process, and the cooperative process. There was little guidance fro...

  3. Inhibitory effect of diet related sulphydryl compounds on the formation of carcinogenic nitrosamines.

    Science.gov (United States)

    Shenoy, N R; Choughuley, A S

    1992-08-31

    N-Nitroso compounds (NOCs) are known to be strong carcinogens in various animals including primates (Preussman and Stewart, (1984) N-Nitroso Compounds). Human exposure to these compounds can be by ingestion or inhalation of preformed NOCs or by endogenous nitrosation from naturally occurring precursors (Bartsch and Montesano, Carcinogenesis, 5 (1984) 1381-1393; Tannebaum (1979) Naturally Occuring Carcinogens, Mutagens and Modulators of Carcinogenesis; Shephard et al., Food Chem. Toxicol., 25 (1987) 91-108). Several factors present in the diet can modify levels of endogenously formed nitrosamines by acting as catalysts or inhibitors. Compounds in the human diet that alter nitrosamine formation would thus play an important role in carcinogenesis study. Earlier researchers have reported the nitrite scavenging nature of sulphydryl compounds (Williams, Chem. Soc. Rev., 15 (1983) 171-196). We therefore studied the modifying effect of sulphydryl compounds viz., cysteine (CE), cystine (CI), glutathione (GU), cysteamine (CEA), cystamine (CEI), cysteic acid (CIA) and thioglycolic acid (TGA) on the nitrosation of model amines viz., pyrrolidine (PYR), piperidine (NPIP) and morpholine (NMOR). Many of these compounds are present in the food we consume. The present work also describes the inhibitory effect of onion and garlic juices on the nitrosation reactions. Both onion and garlic are known to contain sulphur compounds (Block, Sci. Am., 252 (1985) 114-119). Most of these compounds behave as antinitrosating agents and their inhibitory activity towards formation of carcinogenic nitrosamines, under different conditions is described. PMID:1516037

  4. Carcinogenic effects of MGP-7 and B(a)P on the Hamster Cheek Pouch

    Energy Technology Data Exchange (ETDEWEB)

    Brandon, J.L.; Conti, C.J.; Goldstein, L.S.; DiGiovanni, J.; Gimenez-Conti, I.B. [University of Texas MD Anderson Cancer Center, Smithville, TX (United States). Dept. of Carcinogenesis

    2009-10-15

    This study was performed to examine the carcinogenic effects of benzo(a)pyrene (B(a)P) and manufactured gas plant (MGP) residues on the hamster cheek pouch (HCP). Syrian hamsters were treated topically with a suspension of 2%, 10%, or 20% B(a)P or 50% or 100% MGP-7 (a mixture of residues from 7 MGP sites) in mineral oil for eight (short-term study) and sixteen, twenty, twenty-eight, and thirty-two weeks (long-term study). The short-term study showed that B(a)P induced p53 protein accumulation, indicative of genotoxic damage, as well as increased cell proliferation, hyperplasia, and inflammation, which is usually associated with promotional activity. In contrast, the MGP-7 presented only marginal p53 accumulation and induction of BrdU incorporation. In the long-term experiments, animals treated with 2% and 10% of B(a)P continued to show p53 protein accumulation as well as hyperplasia and increased cell proliferation and inflammation. By thirty weeks, all the animals treated with B(a)P had a 100% incidence of squamous cell carcinoma (SCC). Animals treated with 50% and 100% MGP-7 showed only weak hyperplasia and a low proliferation rate and accumulation of p53 protein through thirty-two weeks. Benzo(a)pyrene was highly carcinogenic when used at adequate doses. Manufactured gas plant residue, however, was not carcinogenic in this model.

  5. Modeling Soil Water Retention Curves in the Dry Range Using the Hygroscopic Water Content

    DEFF Research Database (Denmark)

    Chen, Chong; Hu, Kelin; Arthur, Emmanuel;

    2014-01-01

    curves of soils and to predict SWRCs at the dry end using the hygroscopic water content at a relative humidity of 50% (θRH50). The Oswin model yielded satisfactory fits to dry-end SWRCs for soils dominated by both 2:1 and 1:1 clay minerals. Compared with the Oswin model, the Campbell and Shiozawa model......Accurate information on the dry end (matric potential less than −1500 kPa) of soil water retention curves (SWRCs) is crucial for studying water vapor transport and evaporation in soils. The objectives of this study were to assess the potential of the Oswin model for describing the water adsorption...... combined with the Kelvin equation (CS-K) produced better fits to dry-end SWRCs of soils dominated by 2:1 clays but provided poor fits for soils dominated by 1:1 clays. The shape parameter α of the Oswin model was dependent on clay mineral type, and approximate values of 0.29 and 0.57 were obtained for...

  6. Temporal aspects of tumorigenic response to individual and mixed carcinogens. Comprehensive progress report, June 1, 1975--May 31, 1978. [Mouse skin, rats, hamsters

    Energy Technology Data Exchange (ETDEWEB)

    Albert, R.E.; Burns, F.J.; Altshuler, B.

    1978-02-01

    The research proposed here is designed to obtain a better understanding of the temporal kinetics of tumor induction when one or more carcinogens are present simultaneously or sequentially for prolonged periods of time. Studies done to date under this contract have shown that carcinogenesis in mouse skin by polycyclic aromatic hydrocarbon carcinogens is consistent with the induction of dependent and autonomous cell transformations by the carcinogen followed by the conversion of autonomous tumor cells into malignancies at a rate which is determined by the level of carcinogen exposure. Dependent cell transformations remain latent in the skin unless expressed by a promoting agent. Dependent neoplasia appears to follow one-hit kinetics while malignancy is a multihit endpoint. Dose-related and time-related aspects of tumor induction are separable in the initiation-promotion system of mouse skin which along with rat skin and hamster lung is being used as a model for testing hypotheses. Results to date provide the basis for a new interpretation of the linear non-threshold extrapolation model. The broad aim of the study is to provide a basis or rationale for estimating risks associated with prolonged exposures to carcinogens found in the environment and to predict how different tissues and species respond to the same carcinogens.

  7. Modelling total electron content during geomagnetic storm conditions using empirical orthogonal functions and neural networks

    Science.gov (United States)

    Uwamahoro, Jean Claude; Habarulema, John Bosco

    2015-12-01

    It has been shown in ionospheric research that modelling total electron content (TEC) during storm conditions is a big challenge. In this study, TEC modelling was performed over Sutherland (32.38°S, 20.81°E, 41.09°S geomagnetic), South Africa, during storm conditions, using a combination of empirical orthogonal function (EOF) and regression analyses techniques. The neural network (NN) technique was also applied to the same TEC data set, and its output was compared with TEC modeled using the EOF model. TEC was derived from GPS observations, and a geomagnetic storm was defined for Dst≤-50 nT. The hour of the day and the day number of the year, F10.7p and A indices, were chosen as inputs for the modeling techniques to take into account diurnal and seasonal variation of TEC, solar, and geomagnetic activities, respectively. Both EOF and NN models were developed using GPS TEC data for storm days counted from 1999 to 2013 and tested on different storms. For interpolation, the EOF and NN models were validated on storms that occurred during high and low solar activity periods (storms of 2000 and 2006), while for extrapolation the validation was done for the storms of 2014 and 2015, identified based on the provisional Dst index data. A comparison of the modeled TEC with the observed TEC showed that both EOF and NN models perform well for storms with nonsignificant ionospheric TEC response and storms that occurred during period of low solar activity. For storms with significant TEC response, TEC magnitude is well captured during the nighttime and early morning, but short-term features, TEC enhancement, and depression are not sufficiently captured by the models. Statistically, the NN model performs 12.79% better than the EOF model on average, over all storm periods considered. Furthermore, it has been shown that the EOF and NN models developed for a specific station can be used to estimate TEC over other locations within a latitudinal and longitudinal coverage of 8.7

  8. Current issues in carcinogenic effect of low-dose radiation

    International Nuclear Information System (INIS)

    A review of publications dealing with study of radiation sources and biological evaluation of increasing doses of people irradiation under occupational and usual living conditions is presented. The existing natural and artifial irradiation sources are considered. It is noted that all types of ionizing radiations are characterized by high carcinogenic efficiency and can induce benign and malignant tumors practically in all organs. Statistically reliable data in experimental and epidemiological investigations were recorded under the effect of large and mean doses. Minor radiation doses not responsible for visible functional and morphological changes in early periods can cause pathological changes in delayed periods. The data on carcinogenic effect of relatively small radiation doses are available

  9. Environmental carcinogens in human target tissues in culture: Progress report

    International Nuclear Information System (INIS)

    We have accumulated more experimental evidences that demonstrated the comparative approaches with human cells will allow us to predict human risk with good accuracy following exposure to toxic chemicals. We also synthesized several carcinogenic DNA adducts, i.e., the major benzo[a]pyrene DNA adduct, 06-methyldeoxyguanosine, 7-methyl- deoxyguanosine and 2-methyl-deoxyguanosine to be used as standards for quantitating DNA adduct formation in carcinogen exposed cells. A simple synthetic method was developed for preparation of the major B[a]p DNA adduct with yields better than those reported. The main accomplishments related to the originally stated objectives are summarized. 8 refs., 2 figs., 1 tab

  10. A call to expand regulation to all carcinogenic fibrous minerals

    Science.gov (United States)

    Baumann, F.; Steele, I.; Ambrosi, J.; Carbone, M.

    2013-05-01

    The regulatory term "asbestos" groups only the six fibrous minerals that were commercially used among approximately 400. The carcinogenicity of these six regulated minerals has been largely demonstrated and is related to fiber structure, fiber length/diameter ratio, and bio-persistence. From a public perception, the generic term "asbestos" refers to the fibrous minerals that cause asbestosis, mesothelioma and other cancers. However, other non-regulated fibrous minerals are potentially as dangerous as the regulatory asbestos because they share similar physical and chemical properties, epidemiological studies have demonstrated their relationship with asbestos-related diseases, and both in vitro and in vivo experiments have established the toxicity of these minerals. For example, the non-regulated asbestiform winchite and richterite minerals that contaminated the vermiculite mined from Libby, Montana, (USA) were associated with mesothelioma, lung cancer and asbestosis observed among the area's residents and miners. Many other examples of non-regulated carcinogenic fibrous minerals include, but are not limited to, antigorite, arfvedsonite, balangeroite, carlosturanite, erionite, fluoro-edenite, hornblende, mordenite, palygorskite, and sepiolite. To propose a regulatory definition that would provide protection from all carcinogenic fibers, we have conducted an interdisciplinary literature review to compare the characteristics of "asbestos" and of non-regulated mineral fibers that relate to carcinogenicity. We specifically studied two non-regulated fibrous minerals that are associated with asbestos-related diseases: the serpentine antigorite and the zeolite erionite. Both examples underscore the problem of regulation based on commercial, rather than scientific principles: 1) the occurrence of fibrous antigorite in materials used to pave roads has been correlated with high mesothelioma rates in New Caledonia. Antigorite was also the cause of asbestosis in Poland, and in

  11. DEM Model of Wheat Grains in Storage Considering the Effect of Moisture Content in Direct Shear Test

    OpenAIRE

    Hamed Johnny Sarnavi; A. Noor Mohammadi; A. Modares Motlagh; A. Rahmani Didar

    2013-01-01

    Discrete Element Method (DEM) modeling was conducted for predicting strength properties of stored wheat grains in different levels of moisture contents, to extend the knowledge of grain storage beyond current experimental studies in the future. The main features of agricultural and food materials that make them different from mineral materials are strong influence of Moisture Content (MC) on mechanical behavior. Published data on grain and bulk properties of wheat relevant to DEM modeling wer...

  12. Disposition of smoked cannabis with high Δ9-tetrahydrocannabinol content: A kinetic model

    International Nuclear Information System (INIS)

    Introduction: No model exists to describe the disposition and kinetics of inhaled cannabis containing a high THC dose. We aimed to develop a kinetic model providing estimates of the THC serum concentrations after smoking cannabis cigarettes containing high THC doses (up to 69 mg THC). Methods: Twenty-four male non-daily cannabis users smoked cannabis cigarettes containing 29.3 mg, 49.1 mg, and 69.4 mg THC. Blood samples were collected over a period of 0-8 h and serum THC concentrations were measured. A two-compartment open model was fitted on the individual observed data. Results: Large inter-individual variability was observed in the pharmacokinetic parameters. The median pharmacokinetic parameters generated by the model were Cmax = 175 ng/mL, Tmax = 14 min, and AUC0-8h = 8150 ng x min/mL for the 69.4 mg THC dose. Median model results show an almost linear dose response relation for Cmax/Dose = 2.8 x 10-6/mL and AUC0-8h/Dose = 136 x 10-6 min/mL. However, for increasing dose level, there was a clear decreasing trend: Cmax/Dose = 3.4, 2.6 and 2.5 x 10-6/mL and AUC0-8h/Dose = 157, 133 and 117 x 10-6 min/mL for the 29.3, 49.1 and 69.4 mg dose, respectively. Within the restriction of 8 h of observation, the apparent terminal half life of THC was 150 min. Conclusion: The model offers insight into the pharmacokinetics of THC in recreational cannabis users smoking cannabis containing high doses of THC mixed with tobacco. The model is an objective method for providing serum THC concentrations up to 8 h after smoking cannabis with a high THC content (up to 23%).

  13. Paradigm Shift in Data Content and Informatics Infrastructure Required for Generalized Constitutive Modeling of Materials Behavior

    Science.gov (United States)

    Arnold, S. M.

    2006-01-01

    Materials property information such as composition and thermophysical/mechanical properties abound in the literature. Oftentimes, however, the corresponding response curves from which these data are determined are missing or at the very least difficult to retrieve. Further, the paradigm for collecting materials property information has historically centered on (1) properties for materials comparison/selection purposes and (2) input requirements for conventional design/analysis methods. However, just as not all materials are alike or equal, neither are all constitutive models (and thus design/ analysis methods) equal; each model typically has its own specific and often unique required materials parameters, some directly measurable and others indirectly measurable. Therefore, the type and extent of materials information routinely collected is not always sufficient to meet the current, much less future, needs of the materials modeling community. Informatics has been defined as the science concerned with gathering, manipulating, storing, retrieving, and classifying recorded information. A key aspect of informatics is its focus on understanding problems and applying information technology as needed to address those problems. The primary objective of this article is to highlight the need for a paradigm shift in materials data collection, analysis, and dissemination so as to maximize the impact on both practitioners and researchers. Our hope is to identify and articulate what constitutes "sufficient" data content (i.e., quality and quantity) for developing, characterizing, and validating sophisticated nonlinear time- and history-dependent (hereditary) constitutive models. Likewise, the informatics infrastructure required for handling the potentially massive amounts of materials data will be discussed.

  14. Using digital elevation models as an environmental predictor for soil clay contents

    DEFF Research Database (Denmark)

    Greve, Mogens Humlekrog; Bou Kheir, Rania; Greve, Mette Balslev;

    2012-01-01

    Ranging (LIDAR) (in 24- and 90-m resolution), using regression-tree analysis. Ten terrain parameters were generated from these DEMs. These terrain parameters were used along other environmental variables to statistically explain SCC content in Denmark. Results indicated that the SRTM tree model (T1: 90-m...... resolution) explained the variability of SCC measurements quasi-similarly (variance V = 60%) to the LIDAR tree models with 24-m (T2) or 90-m (T3) resolution (V = 60% for T2 and 61.5% for T3). The prediction performances (in terms of RMSE) of the produced maps (using these trees) compared with independent...... higher correlations between measured SCC and SCC predicted from T2 (R2 = 0.60) compared with the other tree models (T1, R2 = 0.56; T3, R2 = 0.54). The modeling results indicate that the SRTM (including derivatives) has less predictive power than the LIDAR DEMs (with different resolutions) for mapping SCC...

  15. A combination of 3D-QSAR, docking, local-binding energy (LBE) and GRID study of the species differences in the carcinogenicity of benzene derivatives chemicals.

    Science.gov (United States)

    Fratev, Filip; Benfenati, Emilio

    2008-09-01

    A combination of 3D-QSAR, docking, local-binding energy (LBE) and GRID methods was applied as a tool to study and predict the mechanism of action of 100 carcinogenic benzene derivatives. Two 3D-QSAR models were obtained: (i) model of mouse carcinogenicity on the basis of 100 chemicals (model 1) and (ii) model of the differences in mouse and rat carcinogenicity on the basis of 73 compounds (model 2). 3D-QSAR regression maps indicated the important differences in species carcinogenicity, and the molecular positions associated with them. In order to evaluate the role of P450 metabolic process in carcinogenicity, the following approaches were used. The 3D models of CYP2E1 for mouse and rat were built up. A docking study was applied and the important ligand-protein residues interactions and oxidation positions of the molecules were identified. A new approach for quantitative assessment of metabolism pathways was developed, which enabled us to describe the species differences in CYP2E1 metabolism, and how it can be related to differences in the carcinogenic potential for a subset of compounds. The binding energies of the important substituents (local-binding energy-LBE) were calculated, in order to quantitatively demonstrate the contribution of the substituents in metabolic processes. Furthermore, a computational procedure was used for determining energetically favourable binding sites (GRID examination) of the enzymes. The GRID procedure allowed the identification of some important differences, related to species metabolism in CYP2E1. Comparing GRID, 3D-QSAR maps and LBE results, a similarity was identified, indicating a relationship between P450 metabolic processes and the differences in the carcinogenicity. PMID:18495507

  16. BioSig3D: High Content Screening of Three-Dimensional Cell Culture Models

    Science.gov (United States)

    Bilgin, Cemal Cagatay; Fontenay, Gerald; Cheng, Qingsu; Chang, Hang; Han, Ju; Parvin, Bahram

    2016-01-01

    BioSig3D is a computational platform for high-content screening of three-dimensional (3D) cell culture models that are imaged in full 3D volume. It provides an end-to-end solution for designing high content screening assays, based on colony organization that is derived from segmentation of nuclei in each colony. BioSig3D also enables visualization of raw and processed 3D volumetric data for quality control, and integrates advanced bioinformatics analysis. The system consists of multiple computational and annotation modules that are coupled together with a strong use of controlled vocabularies to reduce ambiguities between different users. It is a web-based system that allows users to: design an experiment by defining experimental variables, upload a large set of volumetric images into the system, analyze and visualize the dataset, and either display computed indices as a heatmap, or phenotypic subtypes for heterogeneity analysis, or download computed indices for statistical analysis or integrative biology. BioSig3D has been used to profile baseline colony formations with two experiments: (i) morphogenesis of a panel of human mammary epithelial cell lines (HMEC), and (ii) heterogeneity in colony formation using an immortalized non-transformed cell line. These experiments reveal intrinsic growth properties of well-characterized cell lines that are routinely used for biological studies. BioSig3D is being released with seed datasets and video-based documentation. PMID:26978075

  17. EVALUATION OF ANTIOXIDANT AND TOTAL FLAVANOID CONTENT OF MIRABILIS JALAPA LINN USING IN VITRO MODELS

    Directory of Open Access Journals (Sweden)

    Subin Mary Zachariah

    2012-03-01

    Full Text Available The herbal drugs form the backbone of all traditional system of medicine around the world due to their endless therapeutic activity. Mirabilis jalapa Linn has been hailed as a cure for many common pathological conditions affecting the human body. It has folkloric use as antinociceptive, anti-inflammatory agent, laxative, and a host of other uses. The present study was conducted to evaluate the plants potential as an antioxidant lead by using various in vitro models like FRAP (Ferric reducing ability of plasma DCF(AAPH, superoxide anion scavenging activity, nitric oxide scavenging activity and by the estimation of total flavanoid content. The plant exhibited significant inhibition of the superoxide anion and the nitric oxide radicals even at low concentration. The total flavanoid content of the extract was found to be 4.41 ± 0.02 mg /gram. The findings indicate that the methanolic extract of Mirabilis jalapa has potential antioxidant activity which is comparable to the standards. The results concluded that the extract have a potential source of antioxidants of natural origin.

  18. BioSig3D: High Content Screening of Three-Dimensional Cell Culture Models.

    Directory of Open Access Journals (Sweden)

    Cemal Cagatay Bilgin

    Full Text Available BioSig3D is a computational platform for high-content screening of three-dimensional (3D cell culture models that are imaged in full 3D volume. It provides an end-to-end solution for designing high content screening assays, based on colony organization that is derived from segmentation of nuclei in each colony. BioSig3D also enables visualization of raw and processed 3D volumetric data for quality control, and integrates advanced bioinformatics analysis. The system consists of multiple computational and annotation modules that are coupled together with a strong use of controlled vocabularies to reduce ambiguities between different users. It is a web-based system that allows users to: design an experiment by defining experimental variables, upload a large set of volumetric images into the system, analyze and visualize the dataset, and either display computed indices as a heatmap, or phenotypic subtypes for heterogeneity analysis, or download computed indices for statistical analysis or integrative biology. BioSig3D has been used to profile baseline colony formations with two experiments: (i morphogenesis of a panel of human mammary epithelial cell lines (HMEC, and (ii heterogeneity in colony formation using an immortalized non-transformed cell line. These experiments reveal intrinsic growth properties of well-characterized cell lines that are routinely used for biological studies. BioSig3D is being released with seed datasets and video-based documentation.

  19. BioSig3D: High Content Screening of Three-Dimensional Cell Culture Models.

    Science.gov (United States)

    Bilgin, Cemal Cagatay; Fontenay, Gerald; Cheng, Qingsu; Chang, Hang; Han, Ju; Parvin, Bahram

    2016-01-01

    BioSig3D is a computational platform for high-content screening of three-dimensional (3D) cell culture models that are imaged in full 3D volume. It provides an end-to-end solution for designing high content screening assays, based on colony organization that is derived from segmentation of nuclei in each colony. BioSig3D also enables visualization of raw and processed 3D volumetric data for quality control, and integrates advanced bioinformatics analysis. The system consists of multiple computational and annotation modules that are coupled together with a strong use of controlled vocabularies to reduce ambiguities between different users. It is a web-based system that allows users to: design an experiment by defining experimental variables, upload a large set of volumetric images into the system, analyze and visualize the dataset, and either display computed indices as a heatmap, or phenotypic subtypes for heterogeneity analysis, or download computed indices for statistical analysis or integrative biology. BioSig3D has been used to profile baseline colony formations with two experiments: (i) morphogenesis of a panel of human mammary epithelial cell lines (HMEC), and (ii) heterogeneity in colony formation using an immortalized non-transformed cell line. These experiments reveal intrinsic growth properties of well-characterized cell lines that are routinely used for biological studies. BioSig3D is being released with seed datasets and video-based documentation. PMID:26978075

  20. Physiologically based pharmacokinetic modeling of PLGA nanoparticles with varied mPEG content

    Directory of Open Access Journals (Sweden)

    Avgoustakis K

    2012-03-01

    Full Text Available Mingguang Li1, Zoi Panagi2, Konstantinos Avgoustakis2, Joshua Reineke11Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, USA; 2Pharmaceutical Technology Laboratory, Department of Pharmacy, University of Patras, Rion, Patras, GreeceAbstract: Biodistribution of nanoparticles is dependent on their physicochemical properties (such as size, surface charge, and surface hydrophilicity. Clear and systematic understanding of nanoparticle properties' effects on their in vivo performance is of fundamental significance in nanoparticle design, development and optimization for medical applications, and toxicity evaluation. In the present study, a physiologically based pharmacokinetic model was utilized to interpret the effects of nanoparticle properties on previously published biodistribution data. Biodistribution data for five poly(lactic-co-glycolic acid (PLGA nanoparticle formulations prepared with varied content of monomethoxypoly (ethyleneglycol (mPEG (PLGA, PLGA-mPEG256, PLGA-mPEG153, PLGA-mPEG51, PLGA-mPEG34 were collected in mice after intravenous injection. A physiologically based pharmacokinetic model was developed and evaluated to simulate the mass-time profiles of nanoparticle distribution in tissues. In anticipation that the biodistribution of new nanoparticle formulations could be predicted from the physiologically based pharmacokinetic model, multivariate regression analysis was performed to build the relationship between nanoparticle properties (size, zeta potential, and number of PEG molecules per unit surface area and biodistribution parameters. Based on these relationships, characterized physicochemical properties of PLGA-mPEG495 nanoparticles (a sixth formulation were used to calculate (predict biodistribution profiles. For all five initial formulations, the developed model adequately simulates the experimental data indicating that the model is suitable for

  1. Formation and Human Risk of Carcinogenic Heterocyclic Amines Formed from Natural Precursors in Meat

    Energy Technology Data Exchange (ETDEWEB)

    Knize, M G; Felton, J S

    2004-11-22

    A group of heterocyclic amines that are mutagens and rodent carcinogens form when meat is cooked to medium and well-done states. The precursors of these compounds are natural meat components: creatinine, amino acids and sugars. Defined model systems of dry-heated precursors mimic the amounts and proportions of heterocyclic amines found in meat. Results from model systems and cooking experiments suggest ways to reduce their formation and, thus, to reduce human intake. Human cancer epidemiology studies related to consumption of well-done meat products are listed and compared.

  2. A new model for estimating subsurface ice content based on combined electrical and seismic data sets

    Directory of Open Access Journals (Sweden)

    C. Hauck

    2011-06-01

    Full Text Available Detailed knowledge of the material properties and internal structures of frozen ground is one of the prerequisites in many permafrost studies. In the absence of direct evidence, such as in-situ borehole measurements, geophysical methods are an increasingly interesting option for obtaining subsurface information on various spatial and temporal scales. The indirect nature of geophysical soundings requires a relation between the measured variables (e.g. electrical resistivity, seismic velocity and the actual subsurface constituents (rock, water, air, ice. In this work, we present a model which provides estimates of the volumetric fractions of these four constituents from tomographic electrical and seismic images. The model is tested using geophysical data sets from two rock glaciers in the Swiss Alps, where ground truth information in form of borehole data is available. First results confirm the applicability of the so-called 4-phase model, which allows to quantify the contributions of ice-, water- and air within permafrost areas as well as detecting solid bedrock. Apart from a similarly thick active layer with enhanced air content for both rock glaciers, the two case studies revealed a heterogeneous distribution of ice and unfrozen water within Muragl rock glacier, where bedrock was detected at depths of 20–25 m, but a comparatively homogeneous ice body with only minor heterogeneities within Murtèl rock glacier.

  3. A new model for quantifying subsurface ice content based on geophysical data sets

    Directory of Open Access Journals (Sweden)

    C. Hauck

    2010-06-01

    Full Text Available Detailed knowledge of the material properties and internal structures of frozen ground is one of the prerequisites in many permafrost studies. In the absence of direct evidence, such as in-situ borehole measurements, geophysical methods are an increasingly interesting option for obtaining subsurface information on various spatial and temporal scales. The indirect nature of geophysical soundings requires a relation between the measured variables (e.g. electrical resistivity, seismic velocity and the actual subsurface constituents (rock, water, air, ice. In this work we present a model, which provides estimates of the volumetric fractions of these four phases from tomographic electrical and seismic images. The model is tested using geophysical data sets from two rock glaciers in the Swiss Alps, where ground truth information in form of borehole data is available. First results confirm the applicability of the so-called 4-phase model, which allows to quantify the contributions of ice-, water- and air within permafrost areas as well as detecting the firm bedrock. Apart from a similarly thick active layer with enhanced air content for both rock glaciers, the two case studies revealed a heterogeneous distribution of ice and unfrozen water within rock glacier Muragl, where bedrock was detected at depths of 20–25 m, but a comparatively homogeneous ice body with only minor heterogeneities within rock glacier Murtèl.

  4. Modeling the global ionospheric total electron content with empirical orthogonal function analysis

    Institute of Scientific and Technical Information of China (English)

    WAN WeiXing; DING Feng; REN ZhiPeng; ZHANG ManLian; LIU LiBo; NING BaiQi

    2012-01-01

    In the present work we model the global ionospheric total electron content (TEC) with the analysis of empirical orthogonal functions (EOF).The obtained statistical eigen modes,which makeup the modeled TEC,consist of two factors:the eigen vectors mapping TEC patterns at latitude and longitude (or local time LT),and the corresponding coefficients displaying the TEC variations in different time scales,i.e.,the solar cycle,the yearly (annual and semiannual) and the diurnal universal time variations.It is found that the EOF analysis can separate the TEC variations into chief processes and the first two modes illustrate the most of the ionospheric climate properties.The first mode contains both the semiannual component which shows the semiannual ionospheric anomaly and the annual component which shows the annual or non-seasonal ionospheric anomaly.The second mode contains mainly the annual component and shows the normal seasonal ionospheric variation at most latitudes and local time sectors.The annual component in the second mode also manifests seasonal anomaly of the ionosphere at higher mid-latitudes around noontime.It is concluded that the EOF analysis,as a statistical eigen mode method,is resultful in analyzing the ionospheric climatology hence can be used to construct the empirical model for the ionospheric climatology.

  5. A METHODOLOGICAL MODEL FOR INTEGRATING CHARACTER WITHIN CONTENT AND LANGUAGE INTEGRATED LEARNING IN SOCIOLOGY OF RELIGION

    Directory of Open Access Journals (Sweden)

    Moh Yasir Alimi

    2014-02-01

    Full Text Available AbstractIn this article, I describe a methodological model I used in a experimental study on how to integrate character within the practice of Content and Language Integrated Learning (CLIL at the higher education Indonesia.This research can be added to research about character education and CLIL in tertiary education, giving nuances to the practice of CLIL so far predominantly a practice in primary and secondary schools.The research was conducted in Semarang State University, in the Department of Sociology and Anthropology, in Sociology of Religion bilingual class. The research indicates that the integration of character within CLIL enrich the perspective of CLIL by strengthening the use of CLIL for intellectual growth and moral development. On the other side, the use of CLIL with character education gives methods and perspectives to the practice of character education which so far only emphasise contents reforms without learning methods reforms. The research also reveals that the weakness of CLIL in using text for classroom learning can be overcome by the use of specific reading and writing strategies. I develop a practical text strategy which can be effectively used in highly conceptual subject such as sociology of religion. AbstrakArtikel ini bertujuan untuk mendeskripsikan model metodologis yang saya pakai untuk mengintegrasikannya karakter dalam Content and Language Integrated Learning (CLIL pada pendidikan tinggi di Indonesia. Penelitian ini memperkaya penelitian mengenai pendidikan karakter dan penerapan CLIL di perguruan tinggi, selama ini penelitian semacam itu hanya biasa di level lebih rendah. Penelitian dilakukan di Universitas Negeri Semarang, pada kelas bilingual yang diikuti 25 mahasiswa, dan diujikan pada mata kuliah Sosiologi Agama. Pelajaran dari penelitian ini adalah integrasi karakter dalam CLIL dapat memperkaya CLIL. Sebaliknya penggunaan CLIL untuk mendidikkan karakter di kelas bilingual mampu menjawab berbagai tantangan

  6. Modeling sugar content of farmer-managed sugar beets (Beta vulgaris L..

    Directory of Open Access Journals (Sweden)

    Abdullah A. Jaradat

    2012-04-01

    Full Text Available We measured or estimated leaf and root physical and chemical traits of spatio-temporally heterogeneousfield-grown sugar beet throughout its ontogeny during three growing seasons. The objective was toquantify the impact of temporal changes in these traits on root sugar content [S(R; g 100 g-1 root dryweight]. Artificial Neural Network (ANN, in conjunction with thermal time (ºCd, adequately delineatedthe boundaries (mean ± standard deviation, S.D. between S(R during early (41.6 ± 6.2, med (54.5 ± 3.0,and late ontogeny (63.4 ± 2.4, corresponding, respectively to low, medium, and high S(R. Calibrationand validation Partial Least Squares (PLS regression models, using plant physical and chemical traits,predicted and validated sugar content of sugar beet leaves [S(L] and roots [S(R] throughout its ontogenywith significant probabilities. Most physical and all chemical traits exhibited dynamic changesthroughout plant ontogeny and, consequently, negatively or positively impacted S(R. The positiveimpact of S(L and root volume (RV on S(R diminished towards the end of the growing season;whereas, the positive impact of root density (RD and carbon:nitrogen (C:N ratio in leaves [C:N(L] androots [C:N(R] persisted throughout plant ontogeny. Specific leaf area (SLA, in particular, exhibitednegative, then positive impact on S(R. The utility of physical and chemical traits of field-grown sugarbeets in building reliable PLS models was confirmed using multivariate analysis on secondary statistics(residual mean square errors, RMSE and validation coefficients of determination, Q2 whichdiscriminated between and correctly classified low (100%, medium (95% and high (97% S(R groups.The findings may have implications to design management practices that can enhance C:N ratio and Csequestrationin roots, maintain optimum, but not excessive, N level in developing leaves and roots,optimize root sugar content and minimize its variation under field conditions

  7. 18. Adduct detection in human monitoring for carcinogen exposure

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Determination of the covalently bound products (adducts) of carcinogens with DNA or proteins may be used for the monitoring of exposure to these compounds. Protein adducts are generally stable and are not enzymatically repaired, and the use of these for cxposure monitoring is normally carried out with globin or albumin, because

  8. Chronic toxicity and carcinogenicity study of erythritol in rats

    NARCIS (Netherlands)

    Lina, B.A.R.; Bos-Kuijpers, M.H.M.; Til, H.P.; Bär, A.

    1996-01-01

    The potential toxicity and carcinogenicity of erythritol, a low-calorie sugar substitute, were examined in Wistar Crl:(WI) WU BR rats. Groups of 50 rats of each sex consumed diets with 0, 2, 5, or 10% erythritol, or 10% mannitol, for a period of 104-107 weeks. To each of these main groups, two satel

  9. IARC Monographs: 40 Years of Evaluating Carcinogenic Hazards to Humans

    NARCIS (Netherlands)

    Pearce, Neil E; Blair, Aaron; Vineis, Paolo; Ahrens, Wolfgang; Andersen, Aage; Anto, Josep M; Armstrong, Bruce K; Baccarelli, Andrea A; Beland, Frederick A; Berrington, Amy; Bertazzi, Pier A; Birnbaum, Linda S; Brownson, Ross C; Bucher, John R; Cantor, Kenneth P; Cardis, Elisabeth; Cherrie, John W; Christiani, David C; Cocco, Pierluigi; Coggon, David; Comba, Pietro; Demers, Paul A; Dement, John M; Douwes, Jeroen; Eisen, Ellen A; Engel, Lawrence S; Fenske, Richard A; Fleming, Lora E; Fletcher, Tony; Fontham, Elizabeth; Forastiere, Francesco; Frentzel-Beyme, Rainer; Fritschi, Lin; Gerin, Michel; Goldberg, Marcel; Grandjean, Philippe; Grimsrud, Tom K; Gustavsson, Per; Haines, Andy; Hartge, Patricia; Hansen, Johnni; Hauptmann, Michael; Heederik, Dick; Hemminki, Kari; Hemon, Denis; Hertz-Picciotto, Irva; Hoppin, Jane A; Huff, James; Jarvholm, Bengt; Kang, Daehee; Karagas, Margaret R; Kjaerheim, Kristina; Kjuus, Helge; Kogevinas, Manolis; Kriebel, David; Kristensen, Petter; Kromhout, Hans; Laden, Francine; Lebailly, Pierre; LeMasters, Grace; Lubin, Jay H; Lynch, Charles F; Lynge, Elsebeth; 't Mannetje, Andrea; McMichael, Anthony J; McLaughlin, John R; Marrett, Loraine; Martuzzi, Marco; Merchant, James A; Merler, Enzo; Merletti, Franco; Miller, Anthony; Mirer, Franklin E; Monson, Richard; Nordby, Karl-Kristian; Olshan, Andrew F; Parent, Marie-Elise; Perera, Frederica P; Perry, Melissa J; Pesatori, Angela C; Pirastu, Roberta; Porta, Miquel; Pukkala, Eero; Rice, Carol; Richardson, David B; Ritter, Leonard; Ritz, Beate; Ronckers, Cecile M; Rushton, Lesley; Rusiecki, Jennifer A; Rusyn, Ivan; Samet, Jonathan M; Sandler, Dale P; de Sanjose, Silvia; Schernhammer, Eva; Seniori Constantini, Adele; Seixas, Noah; Shy, Carl; Siemiatycki, Jack; Silvermann, Debra T; Simonato, Lorenzo; Smith, Allan H; Smith, Martyn T; Spinelli, John J; Spitz, Margaret R; Stallones, Lorann; Stayner, Leslie T; Steenland, Kyle; Stenzel, Mark; Stewart, Bernard W; Stewart, Patricia A; Symanski, Elaine; Terracini, Benedetto; Tolbert, Paige E; Vainio, Harri; Vena, John; Vermeulen, Roel; Victora, Cesar G; Ward, Elizabeth M; Weinberg, Clarice R; Weisenburger, Dennis; Wesseling, Catharina; Weiderpass, Elisabete; Zahm, Shelia H

    2015-01-01

    BACKGROUND: Recently the International Agency for Research on Cancer (IARC) Programme for the Evaluation of Carcinogenic Risks to Humans has been criticized for several of its evaluations, and also the approach used to perform these evaluations. Some critics have claimed that IARC Working Groups' fa

  10. Modern Electrochemical Methods for Monitoring of Chemical Carcinogens

    OpenAIRE

    Zima, J; Moreira, J.; J. Barek

    2005-01-01

    This contribution is based on our presentation at the 1st International Symposium on Sensor Science, Paris, 16-20 June 2003. It presents recent results regarding the electrochemical determination of submicromolar and nanomolar concentrations of various carcinogenic substances (nitrated polycyclic aromatic hydrocarbons, heterocyclic compounds, azo compounds, aromatic amino compounds, etc.) using both traditional (classical dropping mercury electrode, static mercury drop electrode, hanging merc...

  11. DETECTION OF CARCINOGENICITY BASED ON MUTAGENICITY IN ARABIDOPSIS

    Science.gov (United States)

    Thirty-seven synthetic chemicals plus two mycotoxins were tested for mutagenicity in an Arabidopsis embryo system. The results of this test, prokaryotic repair tests, bacterial mutation assays, eukaryotic cell systems, and in vivo tests were compared to the carcinogenicity classi...

  12. Non—Genotoxic Carcinogens.Approaches to Their Rish Assessment

    Institute of Scientific and Technical Information of China (English)

    J.A.CASTRO; M.I.DiazGomez; 等

    1993-01-01

    Epidemiological studies support the idea that most human cancers are related to chemicals present in the human environment.In turn,chemicals are believed to cause cancer via either genotoxic or non-genotoxic mechanisms.There were described in literature several simple rapid and inexpensive short term ests to reasonably predict the genotoxic nature of chemicals but in contrast,there is no reliable test or battery of tests available to predict the carcinogenicity of non-genotoxic compounds and this poses a major problem to their rish assessment.In addition,there are conflictive opinions about rish assessment needs for both classes of carcinogens.Some workers elieve that for non-genotoxic carcinogens,thresholds for exposure can be drawn while others do not.In this review,the reasons behind both of these opinions and the present hypotheses about the mechanism of action of non-genotoxic carcinogens are described and analyzed in relation to future needs.

  13. Flavonoids and alkenylbenzenes: mechanisms of mutagenic action and carcinogenic risk

    NARCIS (Netherlands)

    Rietjens, I.M.C.M.; Boersma, M.G.; Woude, van der H.; Jeurissen, S.M.F.; Schutte, M.E.; Alink, G.M.

    2005-01-01

    The present review focuses on the mechanisms of mutagenic action and the carcinogenic risk of two categories of botanical ingredients, namely the flavonoids with quercetin as an important bioactive representative, and the alkenylbenzenes, namely safrole, methyleugenol and estragole. For quercetin a

  14. Trichloroethylene: Mechanistic, epidemiologic and other supporting evidence of carcinogenic hazard

    NARCIS (Netherlands)

    Rusyn, Ivan; Chiu, Weihsueh A.; Lash, Lawrence H.; Kromhout, Hans; Hansen, Johnni; Guyton, Kathryn Z.

    2014-01-01

    The chlorinated solvent trichloroethylene (TCE) is a ubiquitous environmental pollutant. The carcinogenic hazard of TCE was the subject of a 2012 evaluation by a Working Group of the International Agency for Research on Cancer (IARC). Information on exposures, relevant data from epidemiologic studie

  15. COMPLEMENTARITY OF GENOTOXIC AND NONGENOTOXIC PREDICTORS OF RODENT CARCINOGENICITY

    Science.gov (United States)

    Twenty-one chemicals known to be carcinogenic in rodent bioassays were selected for study. he chemicals were administered by gavage in two dose levels to female Sprague-Dawley rats. he effects of these 21 chemicals on four biochemical assays (hepatic DNA damage by alkaline elutio...

  16. Normalisation models for accounting for fat content in stable isotope measurements in salmonid muscle tissue

    OpenAIRE

    Abrantes, K.G.; Semmens, J. M.; Lyle, J.M.; Nichols, P D

    2012-01-01

    Stable isotope analysis is increasingly used in ecological studies. Because lipid content influences d13C, lipids should be removed from lipid-rich samples before d13C analysis. To account for differences in d13C arising from differences in lipid content, relationships between lipid content, C:N ratio and ?d13C with lipid removal can be used to normalise lipid content to uniform levels. We investigate these relationships for salmonid muscle and evaluate the suitability of previously published...

  17. An Effective Inservice Model for Content Area Reading in Secondary Schools.

    Science.gov (United States)

    Dupuis, Mary M.; Askov, Eunice N.

    1982-01-01

    Pennsylvania's Content Area Reading Program uses a network of 50 trained instructors to help teachers improve students' content area reading skills. This article covers program content, instructor recruitment and training, variations in program presentation, factors underlying program success, and steps in planning inservice programs in content…

  18. Content-Based Instruction in Foreign Language Education: Models and Methods.

    Science.gov (United States)

    Stryker, Stephen B., Ed.; Leaver, Betty Lou, Ed.

    A collection of essays contains articles on content-based foreign language courses at three levels (beginning, intermediate, advanced) and on foreign languages across the curriculum, including: "Content-Based Instruction: From Theory to Practice" (Stephen B. Stryker, Betty Lou Leaver); "Content-Based Instruction in a Basic Russian Program…

  19. Carcinogenicity of the insulation wools: reassessment of the IARC evaluation.

    Science.gov (United States)

    Brown, R C; Davis, J M; Douglas, D; Gruber, U F; Hoskins, J A; Ilgren, E B; Johnson, N F; Rossiter, C E; Wagner, J C

    1991-08-01

    In assessing the health evidence concerning man-made mineral fibers, the chemical composition, surface activity, durability, and size of fibers have to be taken into account. Special-purpose fine glass fibers need to be separated from the insulation wools (glass, rock, and slag wool). The epidemiological evidence is sufficient to conclude that there has been no mesothelioma risk to workers producing or using glass wool, rock wool, or slag wool. The epidemiological studies have been large and powerful, and they show no evidence of a cause-effect relationship between lung cancer and exposure to glass wool, rock wool, or slag wool fibers. There is some evidence of a small cancer hazard attached to the manufacturing process in slag wool plants 20 to 50 years ago, when asbestos was used in some products and other carcinogenic substances were present. However, this hazard is not associated with any index of exposure to slag wool itself. Animal inhalation studies of ordinary insulation wools also show that there is no evidence of hazard associated with exposure to these relatively coarse, soluble fibers. The evidence of carcinogenicity is limited to experiments with special-purpose fine durable glass fibers or experimental fibers, and only when these fibers are injected directly into the pleural or peritoneal cavity. Multiple chronic inhalation studies of these same special-purpose fine glass fibers have not produced evidence of carcinogenicity. It is suggested that the present IARC evaluation of the carcinogenic risk of insulation wools should be revised to Category 3: not classifiable as to carcinogenicity to humans. PMID:1947241

  20. A Text Classifier Model for Categorizing Feed Contents Consumed by a Web Aggregator

    Directory of Open Access Journals (Sweden)

    H.O.D. Longe

    2014-09-01

    Full Text Available This paper presents a method of using a Text Classifier to automatically categorize the content of web feeds consumed by a web aggregator. The pre-defined category of the feed to be consumed by the aggregator does not always match the content being consumed and categorizing the content using the pre-defined category of the feed curtails user experience as users would not see all the contents belonging to their category of interest. A web aggregator was developed and this was integrated with the SVM classifier to automatically categorize feed content being consumed. The experimental results showed that the text classifier performs well in categorizing the content of feed being consumed and it also affirmed the disparity in the pre-defined category of the source feed and appropriate category of the consumed content.

  1. Production of amines in equine cecal contents in an in vitro model of carbohydrate overload.

    Science.gov (United States)

    Bailey, S R; Rycroft, A; Elliott, J

    2002-10-01

    Acute laminitis can be induced experimentally in horses by the administration of carbohydrate, resulting in fermentation within the cecum and ischemia-reperfusion of the digits. The products of fermentation that trigger acute laminitis are as yet unknown; however, compounds such as amines might play a role due to their potential vasoactive properties. The objectives of this study were to quantify the amines present in equine cecal contents and to use a model of carbohydrate overload in vitro to test the hypothesis that carbohydrate fermentation is associated with increased amine production. Cecal contents from each horse were divided into aliquots and incubated anaerobically with either cornstarch or inulin (a form of fructan carbohydrate; both 1 g/100 mL). The pH was measured and samples were taken at the same time for amine measurement by HPLC at 2-h intervals over a 24-h period. In a second set of experiments, the effects of the antibiotic virginiamycin (1 mg/100 mL), calcium (CaPO4; 0.3 g/100 mL), and plant steroidal saponin (Yucca schidigera extract; 0.1 g/100 mL) were examined on pH and amine concentrations in cecal contents incubated with starch or inulin. Both starch and inulin caused significant time-dependent falls in pH, from 6.7 +/- 0.1 at 0 h to 5.2 +/- 0.1 (starch) and 5.0 +/- 0.1 (inulin) at 24 h. Fermentation of carbohydrate was also associated with increased production of phenylethylamine and isoamylamine (two- to threefold increases) as well as putrescine and cadaverine (1.5- to twofold increases). Virginiamycin inhibited the fall in pH and increases in production of phenylethylamine and isoamylamine, while calcium phosphate moderated the changes in pH only. Yucca schidigera extract was without effect. These data show that fermentation of carbohydrate by equine cecal microbiota may lead to increased production of amines. PMID:12413088

  2. Building Information Modelling and Standardised Construction Contracts: a Content Analysis of the GC21 Contract

    Directory of Open Access Journals (Sweden)

    Aaron Manderson

    2015-08-01

    Full Text Available Building Information Modelling (BIM is seen as a panacea to many of the ills confronting the Architectural, Engineering and Construction (AEC sector. In spite of its well documented benefits the widespread integration of BIM into the project lifecycle is yet to occur. One commonly identified barrier to BIM adoption is the perceived legal risks associated with its integration, coupled with the need for implementation in a collaborative environment. Many existing standardised contracts used in the Australian AEC industry were drafted before the emergence of BIM. As BIM continues to become ingrained in the delivery process the shortcomings of these existing contracts have become apparent. This paper reports on a study that reviewed and consolidated the contractual and legal concerns associated with BIM implementation. The findings of the review were used to conduct a qualitative content analysis of the GC21 2nd edition, an Australian standardised construction contract, to identify possible changes to facilitate the implementation of BIM in a collaborative environment. The findings identified a number of changes including the need to adopt a collaborative contract structure with equitable risk and reward mechanisms, recognition of the model as a contract document and the need for standardisation of communication/information exchange.

  3. MIRI: A Semi-Empirical Model for the Total Electron Content of the Martian Ionosphere

    Science.gov (United States)

    Narvaez, Clara; Mendillo, Michael; Herina, Dylan; Campbell, Bruce

    2016-07-01

    The integral with height of an ionosphere's electron density profile, N _{e}(h), is defined as the total electron content (TEC). It is the total number of electrons in a column of unit area, often expressed in units of 10 ^{16} e ^{-}/m ^{2} at Earth where TEC varies between 2 and 200 such units. Mars has a far less robust ionosphere and the standard unit for TEC is 10 ^{15} e ^{-}/m ^{2}, called a TECU, with martian values being onboard the Mars Express (MEX) and Mars Reconnaissance Orbiter (MRO) derived TEC values as part of range-error corrections and/or radargram phase focusing, and thus large data bases of TEC are now available. In this paper we use a new set of TEC data from the SHARAD experiment on MRO to develop a first-order semi-empirical model of TEC as a function of solar flux and solar zenith angle. The results are validated using a previous analysis of TEC data from the MARSIS radar on MEX, and with recent MAVEN data. A model of TEC is also useful operationally for predicting ranging-errors, phase focusing on radargrams and validation of future N _{e}(h) profiles obtained by radio occultation methods. Since most of the TEC comes from altitudes above the height of maximum electron density, TEC values may be a useful way to assess overall ionospheric escape processes at Mars.

  4. Explorable Three-Dimensional Digital Model of the Female Pelvis, Pelvic Contents, and Perineum for Anatomical Education

    Science.gov (United States)

    Sergovich, Aimee; Johnson, Marjorie; Wilson, Timothy D.

    2010-01-01

    The anatomy of the pelvis is complex, multilayered, and its three-dimensional organization is conceptually difficult for students to grasp. The aim of this project was to create an explorable and projectable stereoscopic, three-dimensional (3D) model of the female pelvis and pelvic contents for anatomical education. The model was created using…

  5. Biostatistical issues in the design and analysis of animal carcinogenicity experiments.

    OpenAIRE

    Portier, C.J.

    1994-01-01

    Two-year animal carcinogenicity experiments are used to evaluate the potential carcinogenicity from exposure to chemicals. The choice of exposure levels, the allocation of animals to doses, the length of exposure, and the choice of interim sacrifice times all affect the power of statistical tests for carcinogenic effects and the variance of interpolated estimates of carcinogenic risk. In this paper, one aspect of this problems is considered: the ability of tumor incidence data to provide info...

  6. Multiple mechanisms for the carcinogenic effects of asbestos and other mineral fibers.

    OpenAIRE

    Barrett, J C; Lamb, P W; Wiseman, R. W.

    1989-01-01

    Asbestos and other mineral fibers are carcinogenic to humans and animals but differ from many carcinogens in that they do not induce gene mutations. An understanding of these interesting human carcinogens, therefore, is an important problem in cancer research. Asbestos and other fibers induce predominantly two types of cancers: mesotheliomas and bronchogenic carcinomas. Fiber size is an important factor in the carcinogenic activity of these substances as has been shown for mesothelioma induct...

  7. In vivo Comet assay on isolated kidney cells to distinguish genotoxic carcinogens from epigenetic carcinogens or cytotoxic compounds.

    Science.gov (United States)

    Nesslany, Fabrice; Zennouche, Nadia; Simar-Meintières, Sophie; Talahari, Ismaïl; Nkili-Mboui, Esther-Nadège; Marzin, Daniel

    2007-06-15

    The objective of this study was to determine the ability of the alkaline in vivo Comet assay (pH>13) to distinguish genotoxic carcinogens from epigenetic carcinogens when performed on freshly isolated kidney cells and to determine the possible interference of cytotoxicity by assessing DNA damage induced by renal genotoxic, epigenetic or toxic compounds after enzymatic isolation of kidney cells from OFA Sprague-Dawley male rats. The ability of the Comet assay to distinguish (1) genotoxicity versus cytotoxicity and (2) genotoxic versus non-genotoxic (epigenetic) carcinogens, was thus investigated by studying five known genotoxic renal carcinogens acting through diverse mechanisms of action, i.e. streptozotocin, aristolochic acids, 2-nitroanisole, potassium bromate and cisplatin, two rodent renal epigenetic carcinogens: d-limonene and ciclosporine and two nephrotoxic compounds: streptomycin and indomethacin. Animals were treated once with the test compound by the appropriate route of administration and genotoxic effects were measured at the two sampling times of 3-6 and 22-26h after treatment. Regarding the tissue processing, the limited background level of DNA migration observed in the negative control groups throughout all experiments demonstrated that the enzymatic isolation method implemented in the current study is appropriate. On the other hand, streptozotocin, 20mg/kg, used as positive reference control concurrently to each assay, caused a clear increase in the mean Olive Tail Moment median value, which allows validating the current methodology. Under these experimental conditions, the in vivo rodent Comet assay demonstrated good sensitivity and good specificity: all the five renal genotoxic carcinogens were clearly detected in at least one expression period either directly or indirectly, as in the case of cisplatin: for this cross-linking agent, the significant decrease in DNA migration observed under standard electrophoresis conditions was clearly amplified

  8. Swedish review strengthens grounds for concluding that radiation from cellular and cordless phones is a probable human carcinogen.

    Science.gov (United States)

    Davis, Devra Lee; Kesari, Santosh; Soskolne, Colin L; Miller, Anthony B; Stein, Yael

    2013-04-01

    higher water content in children's tissues. High resolution computerized models based on human imaging data suggest that children are indeed more susceptible to the effects of EMF exposure at microwave frequencies. If the increased brain cancer risk found in young users in these recent studies does apply at the global level, the gap between supply and demand for oncology services will continue to widen. Many nations, phone manufacturers, and expert groups, advise prevention in light of these concerns by taking the simple precaution of "distance" to minimize exposures to the brain and body. We note than brain cancer is the proverbial "tip of the iceberg"; the rest of the body is also showing effects other than cancers. PMID:23664410

  9. The Integration of Disability Content into Social Work Education: An Examination of Infused and Dedicated Models

    OpenAIRE

    Kristen Faye Bean; Taylor E. Krcek

    2012-01-01

    Disability content has been slowly integrated into social work curricula despite the large proportion of social workers supporting people with disabilities and its requirement in social work education by the Council on Social Work Education Educational Policy and Accreditation Standards. Schools of social work offer disability content to their students in three ways: infused, dedicated (specialization), or a combination of both. A content analysis of 1620 course titles and descriptions from t...

  10. A Novel Stackelberg-Bertrand Game Model for Pricing Content Provider

    OpenAIRE

    Cheng Zhang; Bo Gu; Kyoko Yamori; Sugang Xu; Yoshiaki Tanaka

    2015-01-01

    With the popularity of smart devices such as smartphone, tablet, contents that traditionally be viewed on a personal computer, can also be viewed on these smart devices. The demand for contents thus is increasing year by year, which makes the content providers (CPs) get great revenue from either users’ subscription or advertisement. On the other hand, Internet service providers (ISPs), who keep investing in the network technology or capacity capacity to support the huge traffic generated by c...

  11. Decision Making Model for Business Process Outsourcing of Enterprise Content Management

    OpenAIRE

    Zhuojun Yi; Dongming Xu

    2013-01-01

    Business process outsourcing (BPO) in enterprise content management (ECM) is a growing though immature market. BPO in ECM focuses on pursuing market transactions in the process of managing all types of content being used in organizations. However, inadequate sourcing decisions lead to organizational sensitive content exposure, high transaction cost, poor outsourcer performance, low flexibility. ECM BPO in general is rarely discussed in the literature and no discussion was found on decision ma...

  12. Router Modelling and Packet Level Cache Implementation for Content Aware TCP (CATCP)

    OpenAIRE

    Budigere Ramakrishna, Karthik

    2016-01-01

    Internet is more content oriented than ever before, In today's Internet scalable content access is provided by content distribution networks (CDN), application specific caches, proxies etc. The proliferation of these systems is complex and expensive. In the past few years many data-oriented or information-centric network architectures have been proposed such as DONA, PSIRP, CCN etc, but these new clean-state architecture proposals have seen little deployment because of its expensive initial c...

  13. A Text Classifier Model for Categorizing Feed Contents Consumed by a Web Aggregator

    OpenAIRE

    H.O.D. Longe; Fatai Salami

    2014-01-01

    This paper presents a method of using a Text Classifier to automatically categorize the content of web feeds consumed by a web aggregator. The pre-defined category of the feed to be consumed by the aggregator does not always match the content being consumed and categorizing the content using the pre-defined category of the feed curtails user experience as users would not see all the contents belonging to their category of interest. A web aggregator was developed and this was integrated with t...

  14. Modelling global change impacts on soil carbon contents of agro-silvo-pastoral Mediterranean systems

    Science.gov (United States)

    Lozano-García, Beatriz; Muñoz-Rojas, Miriam; Parras-Alcántara, Luis

    2016-04-01

    To assess the impact of climate change on soil organic C (SOC) stocks in agro-silvo-pastoral environments, different models have been applied worldwide at local or regional scales, such as as RothC (Francaviglia et al., 2012) or CENTURY (Alvaro-Fuentes et al., 2012). However, some of these models may require a high number of input parameters or can underestimate the effect of soil depth. CarboSOIL (Muñoz-Rojas et al., 2013) is an empirical model based on regression techniques and developed to predict SOC contents at standard soil depths (0-25, 25-50 and 50-75 cm) under a range of climate and/or land use change scenarios. CarboSOIL has been successfully applied in different Mediterranean areas ,e.g. Southern Spain (Muñoz-Rojas et al., 2013; Abd-Elmabod et al., 2014), Northern Egypt (Muñoz-Rojas et al., 2014) and Italy (Muñoz-Rojas et al., 2015). In this study, CarboSOIL was applied in the Cardeña and Montoro mountain range Natural Park. This area covers 385 km2 and is located within Sierra Morena (Córdoba, South Spain) and has a semiarid Mediterranean climate. It is characterized by agro-silvo-pastoral systems. The Mediterranean evergreen oak woodland (MEOW-dehesa) is savanna-like open woodland ecosystem characterized by silvopastoral uses, being an ancient human modified Mediterranean landscape (Corral-Fernández et al., 2013; Lozano-García and Parras-Alcántara 2013). The most representative soils in the Cardeña and Montoro mountain range Natural Park are Cambisols, Regosols, Leptosols and Fluvisols. These soils are characterized by low fertility, poor physical conditions and marginal capacity for agricultural use, together with low organic matter (OM) content due to climate conditions (semiarid Mediterranean climate) and soil texture (sandy). The model was applied at different soil depths: 0-25, 25-50 and 50-75 cm (Parras-Alcántara et al., 2015) considering land use and climate changes scenarios based on available global climate models (IPPC, 2007). A

  15. Superstrings, entropy and the elementary particles content of the standard model

    International Nuclear Information System (INIS)

    A number of interconnected issues involving superstring theory, entropy and the particle content of the standard model of high energy physics are discussed in the present work. It is found that within a non-transfinite approximation, the number of elementary particles is given by DimSU(8) in full agreement with the prediction gained from dividing the total number of the massless level of Heterotic string theory (256)(16)=8064 by the spin representation 27=128 which gives DimSU(8)=(8)2-1=(8064)/(128)=63 particles. For the exact transfinite case however, one finds our previously established E-infinity result:N=(336+16k)(3/2+k)(16+k)/(128+8k)=α-bar o/2,where k=φ3(1-φ3), φ=(5-1)/2 and α-bar o/2=68.54101965. Setting k=0 one finds that n=63 exactly as in the non-transfinite case

  16. Genetic control of soybean seed isoflavone content: importance of statistical model and epistasis in complex traits.

    Science.gov (United States)

    Gutierrez-Gonzalez, Juan Jose; Wu, Xiaolei; Zhang, Juan; Lee, Jeong-Dong; Ellersieck, Mark; Shannon, J Grover; Yu, Oliver; Nguyen, Henry T; Sleper, David A

    2009-10-01

    A major objective for geneticists is to decipher genetic architecture of traits associated with agronomic importance. However, a majority of such traits are complex, and their genetic dissection has been traditionally hampered not only by the number of minor-effect quantitative trait loci (QTL) but also by genome-wide interacting loci with little or no individual effect. Soybean (Glycine max [L.] Merr.) seed isoflavonoids display a broad range of variation, even in genetically stabilized lines that grow in a fixed environment, because their synthesis and accumulation are affected by many biotic and abiotic factors. Due to this complexity, isoflavone QTL mapping has often produced conflicting results especially with variable growing conditions. Herein, we comparatively mapped soybean seed isoflavones genistein, daidzein, and glycitein by using several of the most commonly used mapping approaches: interval mapping, composite interval mapping, multiple interval mapping and a mixed-model based composite interval mapping. In total, 26 QTLs, including many novel regions, were found bearing additive main effects in a population of RILs derived from the cross between Essex and PI 437654. Our comparative approach demonstrates that statistical mapping methodologies are crucial for QTL discovery in complex traits. Despite a previous understanding of the influence of additive QTL on isoflavone production, the role of epistasis is not well established. Results indicate that epistasis, although largely dependent on the environment, is a very important genetic component underlying seed isoflavone content, and suggest epistasis as a key factor causing the observed phenotypic variability of these traits in diverse environments. PMID:19626310

  17. Combining ERT and modeling for investigating soil water content variability in a Maize field

    Science.gov (United States)

    Beff, Laure; Couvreur, Valentin; Gunther, Thomas; Draye, Xavier; Javaux, Mathieu

    2014-05-01

    In this study we monitored the 3-D soil water content (SWC) evolution in a Maize field plot (3.9 m long, 1.8 m wide and 1.4 m deep) during a drying period of two weeks with Electrical Resistivity Tomography (ERT). Our aim was to identify how SWC was evolving with time and whether SWC variability was mainly induced by difference between plants (inter-plants) and by the roots distribution of the plants themselves (intra-plant). Field SWC monitoring was realized at four dates with Electrical Resistivity Tomography (ERT). At the plot scale, the variability was mainly impacted by the vertical differences of SWC (between 61% and 85%), especially at the end of the drying period when the difference of SWC between surface and depth was the most important. The SWC distribution was largely affected by the presence of the maize rows. When the soil dried out, the SWC variability induced by root distribution, and indirectly by the sowing pattern in rows, became prevalent. By using biophysical numerical model, we were able to properly simulate the evolution of the SWC variability induced by the root distribution during the 15-d period and characterize the amount of compensation induced by the plant root system.

  18. Vesiculation in rhyolite at low H2O contents: A thermodynamic model

    Science.gov (United States)

    Ryan, Amy G.; Russell, James K.; Hess, Kai-Uwe; Phillion, Andre B.; Dingwell, Donald B.

    2015-12-01

    We present experimental data on the thermodynamics and kinetics of bubble nucleation and growth in weakly H2O-oversaturated rhyolitic melts. The high-temperature (900-1100°C) experiments involve heating of rhyolitic obsidian from Hrafntinnuhryggur, Krafla, Iceland to above their glass transition temperature (Tg ˜ 690°C) at 0.1 MPa for times of 0.25-24 h. During experiments, the rhyolite cores increase in volume as H2O vapor-filled bubbles nucleate and expand. The extent of vesiculation, as tracked by porosity, is mapped in temperature-time (T-t) space. At constant temperature and for a characteristic dwell time, the rhyolite cores achieve a maximum volume where the T-t conditions reach thermochemical equilibrium. For each T-t snapshot of vesiculation, we use 3-D analysis of X-ray computed tomographic (XCT) images of the quenched cores to obtain the bubble number density (BND) and bubble-size distribution (BSD). BNDs for the experimental cores are insensitive to T and t, indicating a single nucleation event. All BSDs converge to a common distribution, independent of T, melt viscosity (η), or initial degree of saturation, suggesting a common growth process. We use these data to calibrate an empirical model for predicting the rates and amounts of vesiculation in rhyolitic melts as a function of η and thermochemical affinity (A): two computable parameters that are dependent on T, pressure and H2O content. The model reproduces the experimental data set and data from the literature to within experimental error, and has application to natural volcanic systems where bubble formation and growth are not diffusion limited (e.g., lavas, domes, ignimbrites, conduit infill).

  19. Study on Model of Correlation Between Chemical Element Contents in Tree Rings and Soils near Tree Roots

    Institute of Scientific and Technical Information of China (English)

    KESHAN-ZHE; QIANJUN-LONG; 等

    1994-01-01

    The chemical element contents in tree rings are correlated with those in the soils near the tree roots,The results in the present study showed that the correlation between them could be described using the following logarithmic linear correlation model:lgC'(Z)=a(Z)+b(Z)lgC(Z).Therefor,by determining the chrono-sequence C(Z,t),where Z is the atomic number and t the year,of elemental contents in the annual growth rings of trees,we could get the chrono-sequence C'(Z,t) of elemental contents in the soil,thus inferring the dynaminc variations of relevant elemental contents in the soil.

  20. [Update on benzene: from industrial toxicant to environmental carcinogen].

    Science.gov (United States)

    Manno, Maurizio

    2013-01-01

    Benzene, an industrial chemical myelotoxic at high doses in workers, is now an almost ubiquitous pollutant. It is also a no-threshold genotoxic carcinogen causing acute leukemia and other lymphoaematological tumours. Although its mechanism of action has not been fully clarified, benzene toxicity and carcinogenicity depend on metabolic activation. Polymorphism of activating and detoxifying enzymes (CYP, GST, NQO1) may be critical, therefore, in modulating individual susceptibility to benzene. Further uncertainty factors in assessing low level benzene exposure are the limited sensitivity and specificity of most exposure biomarkers, the frequent coexposure to other volatile organic chemicals (VOC), and the presence of non occupational sources of exposure, such as cigarette smoke and veicular traffic. The aim of this presentation is to introduce the main current critical issues in the risk assessment and the biological monitoring of occupational exposure to benzene at low doses. PMID:24303704

  1. Station Based Polynomial Modeling of the local ionospheric Vertical Total Electron Content (VTEC) using Particle Filter

    Science.gov (United States)

    Erdogan, Eren; Onur Karslioglu, Mahmut; Durmaz, Murat; Aghakarimi, Armin

    2014-05-01

    parameters, Ionospheric VTEC map covering the predefined region has been produced by interpolation. VTEC values at a grid node of the map have been computed based on the four closest ground stations by means of inverse distance squared weighted average. The GPS data which is acquired from ground based stations have been made available from the International GNSS Service (IGS) and the Reference Frame Sub-commission for Europe (EUREF). Raw GPS observations have been preprocessed to detect cycle slips and to form geometry-free linear combinations of observables for each continuous arc. Then the obtained pseudoranges have been smoothed with the carrier to code leveling method. Finally, the performance of the particle filter to investigate the local characteristics of the ionospheric Vertical Total Electron Content (VTEC) has been evaluated and the result has been compared with the result of a standard Kalman filter. Keywords: ionosphere, GPS , Particle filer, VTEC modeling

  2. SAFETY ANALYSIS REPORT FOR PACKAGING, MODEL 9977, ADDENDUM 3, JUSTIFICATION FOR SMALL GRAM QUANTITY CONTENTS

    Energy Technology Data Exchange (ETDEWEB)

    Abramczyk, G.

    2011-10-31

    This Addendum establishes a new family of content envelopes consisting of small quantities of radioactive materials. These content envelopes and specific packing configurations are shown to be subcritical. However, the dose rates of some payloads must be measured and shown to comply with applicable radiation limits. Authorization for shipment of the content envelop requires acceptance of this Addendum by the DOE-HQ certifying official as a supplement to the 9977 SARP Revision 2 and DOE-HQ's subsequent revision of the CoC Revision 10 (which is based on SARP Addendum 2 and SARP Addendum 4) to authorize the additional content envelope. The Small Gram Quantity Content Envelopes and packing configurations will be incorporated in the next revision of the 9977 SARP.

  3. Mammalian cell transformation: Mechanisms of carcinogenesis and assays for carcinogens

    International Nuclear Information System (INIS)

    This book contains nine sections, each consisting of several papers. The section titles are: Molecular Changes in Cell Transformation; Differentiation, Growth Control, and Cell Transformation; Mutagenesis and Cell Transformation; Tumor Promotion and Cell Transformation; Mechanisms of Transformation of Human Fibroblasts; Mechanisms of Transformation of Epithelial Cells; Mechanisms of C3H 10T12 Cell Transformation; Mechanisms of Radiation-Induced Cell Transformation; and Use of Cell Transformation Assays for Carcinogen Testing

  4. Cannabis and tobacco smoke are not equally carcinogenic

    OpenAIRE

    Melamede Robert

    2005-01-01

    Abstract More people are using the cannabis plant as modern basic and clinical science reaffirms and extends its medicinal uses. Concomitantly, concern and opposition to smoked medicine has occurred, in part due to the known carcinogenic consequences of smoking tobacco. Are these reactions justified? While chemically very similar, there are fundamental differences in the pharmacological properties between cannabis and tobacco smoke. Cannabis smoke contains cannabinoids whereas tobacco smoke c...

  5. Gene discovery for the carcinogenic human liver fluke, Opisthorchis viverrini

    OpenAIRE

    Gasser Robin B; Smout Michael J; Sripa Manop; Sripa Banchob; Mulvenna Jason; Pinlaor Porntip; Laha Thewarach; Brindley Paul J; Loukas Alex

    2007-01-01

    Abstract Background Cholangiocarcinoma (CCA) – cancer of the bile ducts – is associated with chronic infection with the liver fluke, Opisthorchis viverrini. Despite being the only eukaryote that is designated as a 'class I carcinogen' by the International Agency for Research on Cancer, little is known about its genome. Results Approximately 5,000 randomly selected cDNAs from the adult stage of O. viverrini were characterized and accounted for 1,932 contigs, representing ~14% of the entire tra...

  6. Identification of carcinogens in cooking oil fumes.

    Science.gov (United States)

    Chiang, T A; Wu, P F; Ko, Y C

    1999-07-01

    According to earlier studies, fumes from cooking oils were found to be genotoxic in several short-term tests such as the Ames test, sister chromatid exchange, and SOS chromotest. Fume samples from six different commercial cooking oils (safflower, olive, coconut, mustard, vegetable, and corn) frequently used in Taiwan were collected. Polycyclic aromatic hydrocarbons (PAHs) were extracted from the air samples and identified by high-performance liquid chromatography and confirmed by gas chromatography/mass spectrometry. Extracts of fumes from safflower oil, vegetable oil, and corn oil contained benzo[a]pyrene (BaP), dibenz[a,h]anthracene (DBahA), benzo[b]fluoranthene (BbFA), and benzo[a]anthracene (BaA). Concentrations of BaP, DbahA, BbFA, and BaA were 2.1, 2.8, 1.8, and 2.5 microg/m3 in fumes from safflower oil; 2.7, 3.2, 2.6, and 2.1 microg/m3 in vegetable oil; and 2.6, 2.4, 2.0, and 1.9 microg/m3 in corn oil, respectively. The authors constructed models to study the efficacy of table-edged fume extractors used commonly by Taiwanese restaurants. Concentrations of BaP were significantly decreased when the fume extractor was working (Pextractors near cooking pots. PMID:10361022

  7. Different mechanisms of modulation of gap junction communication by non-genotoxic carcinogens in rat liver in vivo

    International Nuclear Information System (INIS)

    This is a comparative study of the mechanisms by which three different rodent non-genotoxic carcinogens modulate connexin-mediated gap junction intercellular communication in male rat liver in vivo. In the case of the peroxisome proliferating agent Wy-14,643, a non-hepatotoxic dose of 50 mg/kg led to a marked loss of inter-hepatocyte dye transfer associated with a loss of both Cx32 and Cx26 protein expression. In contrast, p,p'-dichlorodiphenyltrichloroethane (DDT) at a non-hepatotoxic dose (25 mg/kg) was not found to alter Cx32 or Cx26 expression or to produce a measurable Cx32 serine phosphorylation but did give a small, significant reduction of cell communication. Carbon tetrachloride (CCl4) did not affect cell communication (despite a small significant reduction of Cx32 content) at a non-hepatotoxic dose. Both loss of communication and Cx32 expression was observed only at a dose that caused hepatocyte toxicity as evidenced by increased serum alanine aminotransferase activity. Overall, the findings emphasise that loss of gap junctional communication in vivo can contribute to carcinogenesis by non-genotoxic carcinogens through different primary mechanism. In contrast to Wy-14,643 and DDT, the results with CCl4 are consistent with a requirement for hepatotoxicity in its carcinogenic action

  8. [MATline, a job-exposure matrix for the prevision of exposure to carcinogens: new functions and potential applications].

    Science.gov (United States)

    Falcone, Umberto; Gilardi, Luisella; Santoro, Silvano; Orengia, Manuela; Marighella, Massimo; Coffano, Maria Elena

    2013-01-01

    MATline, the job-exposure matrix for carcinogenic agents, is a data bank free accessible online. It provides data as classification and toxicological properties of carcinogenic agents, and a list of industrial processes with potential exposure to each carcinogen agent, and an up-to-date estimation of the number of activities and workers related to the industrial process on Regional basis. It also lists the target organs for which a causal relationship with the agent has been established. MATline was recently updated with the new classifications introduced by Regulation EC No. 1272/2008 (CLP). The Authorisation List or the Restriction of the Registration, Evaluation, Authorization of Chemicals (REACh) regulation specifically mark chemicals. The matrix is helpful for professionals in the public health sector to identify in advance the potential sources of exposure, and prioritise intervention plans; for occupational physicians to help identifying causes of occupational cancer cases; for health professionals in the private sector to address chemical risks; for company physicians to validate health surveillance plans; for trade unions to independently check formation contents provided to workers potentially exposed to such risks. PMID:23585435

  9. The establishment and evaluation of near infrared universal model to determinate the effective ingredient content in pesticide rapidly

    Institute of Scientific and Technical Information of China (English)

    Yan Mei Xiong; Xiang Zhong Song; Chang Zhou Chen; Hong Ping Lin; Guo Tang; Yue Huang; Jia Duan; Shun Geng Min

    2012-01-01

    A near infrared universal quantitative analysis model was established to determinate the effective ingredient content in pesticide EC (hikernalisation) by the PLS (partial least squares) algorithm,the model predictive ability was evaluated by the external inspection method.The model was established among samples containing the same active ingredient from five different companies,and the model determination coefficient R2 and RMSECV (root mean square error of cross validation) were 0.9997 and 0.0223,respectively,the relative error between predicted value and chemical value of the testing set samples was between -2.71% and 3.36%,which indicated that the method to determinate the effective ingredient content in pesticide EC by the established universal model can meet the need of pesticide market monitoring.

  10. Measurement of total anthocyanins content in flowering tea using near infrared spectroscopy combined with ant colony optimization models.

    Science.gov (United States)

    Xiaowei, Huang; Xiaobo, Zou; Jiewen, Zhao; Jiyong, Shi; Xiaolei, Zhang; Holmes, Mel

    2014-12-01

    Flowering tea has become a popular beverage consumed across the world. Anthocyanins content is considered as an important quality index of flowering tea. The feasibility of using near infrared (NIR) spectra at the wavelength range of 10,000-4000 cm(-1) for rapid and nondestructive determination of total anthocyanins content in flowering tea was investigated. Ant colony optimization interval partial least squares (ACO-iPLS) and Genetic algorithm interval partial least squares (GA-iPLS) were used to develop calibration models for total anthocyanins content. Two characteristic wavelength regions (4590-4783, 5770-5,963 cm(-1)), which corresponding to the ultraviolet/visible absorption bands of anthocyanins, were selected by ACO-iPLS. The optimal ACO-iPLS model for total anthocyanins content (R=0.9856, RMSECV=0.1,198 mg/g) had better performance than full-spectrum PLS, iPLS, and GA-iPLS models. It could be concluded that NIR spectroscopy has significant potential in the nondestructive determination of total anthocyanins content in flowering tea. PMID:24996367

  11. Cellular-signaling pathways unveil the carcinogenic potential of chemicals.

    Science.gov (United States)

    Hendriks, Giel; van de Water, Bob; Schoonen, Willem; Vrieling, Harry

    2013-06-01

    Most of the current in vitro carcinogenicity assays assess the potential carcinogenic properties of chemicals through the detection of inflicted DNA damage or subsequent chromosome damage and gene mutations. Unfortunately, these assays generally do not provide mechanistic insight into the reactive properties of a chemical. Upon chemical-induced damage of biomolecules, molecular sensors will activate general and damage-specific cellular response pathways that provide protection against the (geno)toxic and potential carcinogenic properties of chemicals. These cellular defense mechanisms include activation of cell-cycle checkpoints, DNA repair systems and induction of apoptosis or necrosis. Visualization of activated cellular-signaling pathways forms a powerful means to readily detect the genotoxic potential of chemical compounds and simultaneously gain insight into their reactive properties. Over the past years, various in vitro reporter assays have been developed that monitor activation of general and more specific cellular-signaling pathways, including the GreenScreen HC and ToxTracker assays. In this review we provide a perspective on how we can exploit activation of cellular signaling pathways to shed light on the mode of action of the chemical exposure and to develop sophisticated mechanism-based in vitro assays for cancer risk assessment. PMID:23339022

  12. Workplace carcinogen and pesticide exposures in Costa Rica.

    Science.gov (United States)

    Partanen, Timo; Chaves, Jorge; Wesseling, Catharina; Chaverri, Fabio; Monge, Patricia; Ruepert, Clemens; Aragón, Aurora; Kogevinas, Manolis; Hogstedt, Christer; Kauppinen, Timo

    2003-01-01

    The CAREX data system converts national workforce volumes and proportions of workers exposed to workplace carcinogens into numbers of exposed in 55 industrial categories. CAREX was adapted for Costa Rica for 27 carcinogens and seven groups of pesticides. Widespread workplace carcinogens in the 1.3 million workforce of Costa Rica are solar radiation (333,000 workers), diesel engine exhaust (278,000), environmental tobacco smoke (71,000), hexavalent chromium compounds (55,000), benzene (52,000), wood dust (32,000), silica dust (27,000), lead and inorganic lead compounds (19,000), and polycyclic aromatic compounds (17,000). The most ubiquitous pesticides were paraquat and diquat (175,000), mancozeb, maneb, and zineb (49,000), chlorothalonil (38,000), benomyl (19,000), and chlorophenoxy herbicides (11,000). Among women, formaldehyde, radon, and methylene chloride overrode pesticides, chromium, wood dust, and silica dust in numbers of exposed. High-risk sectors included agriculture, construction, personal and household services, land and water transport and allied services, pottery and similar industries, woodworks, mining, forestry and logging, fishing, manufacturing of electrical machinery, and bar and restaurant personnel. PMID:12848237

  13. Potential co-carcinogens in the uranium mine environment

    International Nuclear Information System (INIS)

    Studies of increased incidence of lung cancer in uranium miners have focussed on the relationship between lung cancer and miners' exposure to radon daughters and smoking. However, epidemiologic analyses of uranium miner populations also include the effects of exposure to external gamma rays, long-lived alpha emitters and other non-radioactive workplace contaminants. The diversity and variability of miner exposures to potentially carcinogenic substances and combinations of substances, and the natural difficulties involved in the study of lung cancer in human populations, make the assessment of the relative effects of causative agents difficult if not impossible. Moreover, concentrations of most of the substances have rarely been measured in mine environments, and data on human response to these substances is sparse. Nonetheless, research on the potential effects of such substances is required to understand the potential hazards in the mining environment. This paper examines the potential carcinogenic and co-carcinogenic effects of agents other than ionizing radiation, which may currently be present in uranium mine atmospheres

  14. Artificial sweeteners--do they bear a carcinogenic risk?

    Science.gov (United States)

    Weihrauch, M R; Diehl, V

    2004-10-01

    Artificial sweeteners are added to a wide variety of food, drinks, drugs and hygiene products. Since their introduction, the mass media have reported about potential cancer risks, which has contributed to undermine the public's sense of security. It can be assumed that every citizen of Western countries uses artificial sweeteners, knowingly or not. A cancer-inducing activity of one of these substances would mean a health risk to an entire population. We performed several PubMed searches of the National Library of Medicine for articles in English about artificial sweeteners. These articles included 'first generation' sweeteners such as saccharin, cyclamate and aspartame, as well as 'new generation' sweeteners such as acesulfame-K, sucralose, alitame and neotame. Epidemiological studies in humans did not find the bladder cancer-inducing effects of saccharin and cyclamate that had been reported from animal studies in rats. Despite some rather unscientific assumptions, there is no evidence that aspartame is carcinogenic. Case-control studies showed an elevated relative risk of 1.3 for heavy artificial sweetener use (no specific substances specified) of >1.7 g/day. For new generation sweeteners, it is too early to establish any epidemiological evidence about possible carcinogenic risks. As many artificial sweeteners are combined in today's products, the carcinogenic risk of a single substance is difficult to assess. However, according to the current literature, the possible risk of artificial sweeteners to induce cancer seems to be negligible. PMID:15367404

  15. Effects of electro-acupuncture on brain tissue norepinephrine contents in a morphine withdrawal anxiety mouse model

    Institute of Scientific and Technical Information of China (English)

    Qizhi Zhou; Yuxing Liu; Xuguang Liu; Jiaolu Wei; Yong Tang; Junmei Wu; Yi Pu

    2008-01-01

    BACKGROUND: Following morphine withdrawal, anxiety is associated with abnormal norepinephrine content change. However, increasing blood lactic acid content can induce anxiety or panic in patients with anxiety disorder or endogenous opioid peptide functional disorder. OBJECTIVE: This study was designed to observe the effects of electro-acupuncture, at the "Sanyinjiao" point (SP 6), on brain tissue norepinephrine and blood lactic acid content in anxiety-model mice after morphine withdrawal.DESIGN: A randomized controlled animal experiment. SETTING: This study was performed in the Laboratory of Acupuncture, Electro-acupuncture & Tuina College, Chengdu University of Traditional Chinese Medicine, from June to September 2001.MATERIALS: A total of 50 healthy Kunming male mice were provided by the Laboratory Animal Center of Chengdu University of Traditional Chinese Medicine. The protocol was performed in accordance with ethical guidelines stated in the Guide for the use and care of laboratory animals, approved by the Committee on the Care and Use of Laboratory Animals of the Institute of Laboratory Animal Resources Commission on Life Sciences, National Research Council, China (1985). Experimental reagents and equipment used were as follows: morphine hydrochloride (Lot No. 930503, Shenyang No.1 Pharmaceutical Factory, China), norepinephrine (Sigma Chemical Company, USA), fluorospectrophotometer (RF-510, Shimadzu Corporation, Japan), Han electro-acupuncture apparatus (WQ 1002, No. zun (91)-227270-588, Beijing Anlong Photoelectricity-Technique Company, China), and T-maze (self-made). METHODS: A total of 50 mice were randomly divided into 5 groups, with 10 mice in each group: blank control, T-maze, model, model + electro-acupuncture, and electro-acupuncture groups. Establishment of anxiety model after morphine withdrawal: the mouse hot plate assay was used to detect the activity of morphine. The median effective dose of morphine, 2.95 mg/kg, was defined as the base. Mice were

  16. Mitochondrial DNA content contributes to climate adaptation using Chinese populations as a model.

    Directory of Open Access Journals (Sweden)

    Yao-Ting Cheng

    Full Text Available Maintaining a balance between ATP synthesis and heat generation is crucial for adapting to changes in climate. Variation in the mitochondrial DNA (mtDNA, which encodes 13 subunits of the respiratory chain complexes, may contribute to climate adaptation by regulating thermogenesis and the use of bioenergy. However, studies looking for a relationship between mtDNA haplogroups and climate have obtained mixed results, leaving unresolved the role of mtDNA in climate adaptation. Since mtDNA content can regulate human bioenergy processes and is known to influence many physiological traits and diseases, it is possible that mtDNA content contributes to climate adaptation in human populations. Here, we analyze the distribution of mtDNA content among 27 Chinese ethnic populations residing across China and find a significant association between mtDNA content and climate, with northern populations having significantly higher mtDNA content than southern populations. Functional studies have shown that high mtDNA content correlates with an increase in the expression of energy metabolism enzymes, which may accelerate thermogenesis. This suggests that the significantly higher mtDNA content observed in northern populations may confer a selective advantage in adapting to colder northern climates.

  17. Three-band model for noninvasive estimation of chlorophyll, carotenoids, and anthocyanin contents in higher plant leaves

    Science.gov (United States)

    Gitelson, Anatoly A.; Keydan, Galina P.; Merzlyak, Mark N.

    2006-06-01

    Leaf pigment content and composition provide important information about plant physiological status. Reflectance measurements offer a rapid, nondestructive technique to estimate pigment content. This paper describes a recently developed three-band conceptual model capable of remotely estimating total of chlorophylls, carotenoids and anthocyanins contents in leaves from many tree and crop species. We tuned the spectral regions used in the model in accord with pigment of interest and the optical characteristics of the leaves studied, and showed that the developed technique allowed accurate estimation of total chlorophylls, carotenoids and anthocyanins, explaining more than 91%, 70% and 93% of pigment variation, respectively. This new technique shows a great potential for noninvasive tracking of the physiological status of vegetation and the impact of environmental changes.

  18. Social media fundamentals, models, and ranking of user-generated content

    CERN Document Server

    Wyrwoll, Claudia

    2014-01-01

    The increasing amount of user-generated content available on social media platforms requires new methods to find, evaluate, and to compare. To this day, existing ranking approaches to user-generated content do not allow for evaluation across platforms by exploiting its metadata. User-generated content, such as blog postings, forum discussions, shared videos etc. does however contain information that can be used for its evaluation independent of specific search interests. Claudia Wyrwoll presents a query- and language-independent ranking approach that allows for global evaluation of user-genera

  19. Evaluation of carcinogenic potential of the herbicide glyphosate, drawing on tumor incidence data from fourteen chronic/carcinogenicity rodent studies.

    Science.gov (United States)

    Greim, Helmut; Saltmiras, David; Mostert, Volker; Strupp, Christian

    2015-03-01

    Abstract Glyphosate, an herbicidal derivative of the amino acid glycine, was introduced to agriculture in the 1970s. Glyphosate targets and blocks a plant metabolic pathway not found in animals, the shikimate pathway, required for the synthesis of aromatic amino acids in plants. After almost forty years of commercial use, and multiple regulatory approvals including toxicology evaluations, literature reviews, and numerous human health risk assessments, the clear and consistent conclusions are that glyphosate is of low toxicological concern, and no concerns exist with respect to glyphosate use and cancer in humans. This manuscript discusses the basis for these conclusions. Most toxicological studies informing regulatory evaluations are of commercial interest and are proprietary in nature. Given the widespread attention to this molecule, the authors gained access to carcinogenicity data submitted to regulatory agencies and present overviews of each study, followed by a weight of evidence evaluation of tumor incidence data. Fourteen carcinogenicity studies (nine rat and five mouse) are evaluated for their individual reliability, and select neoplasms are identified for further evaluation across the data base. The original tumor incidence data from study reports are presented in the online data supplement. There was no evidence of a carcinogenic effect related to glyphosate treatment. The lack of a plausible mechanism, along with published epidemiology studies, which fail to demonstrate clear, statistically significant, unbiased and non-confounded associations between glyphosate and cancer of any single etiology, and a compelling weight of evidence, support the conclusion that glyphosate does not present concern with respect to carcinogenic potential in humans. PMID:25716480

  20. Carcinogenic and Non-Carcinogenic Assessment of Phthalates Exposure Through Consumption of Bottled Water During the Storage Time

    OpenAIRE

    M Zare Jeddi; Rastkari, N.; R Ahmadkhaniha; M Alimohammadi; M. Yunesian

    2015-01-01

    Background and Objectives: Bottles for packaging drinking water represent one of the most popular uses of plastic and polymer additives. Recently, public concerns related to possibility of exposure to chemicals through the consumption of polyethylene terephthalate bottled water has caused great concern to consumers. Phthalate esters, as a class of these compounds, are often classified as endocrine disruptors and one of them is a possible carcinogen for human. The aim of this study was to dete...

  1. Modeling of experimental data on trace elements and organic compounds content in industrial waste dumps.

    Science.gov (United States)

    Smoliński, Adam; Drobek, Leszek; Dombek, Václav; Bąk, Andrzej

    2016-11-01

    The main objective of the study presented was to investigate the differences between 20 mine waste dumps located in the Silesian Region of Poland and Czech Republic, in terms of trace elements and polycyclic aromatic hydrocarbons contents. The Principal Component Analysis and Hierarchical Clustering Analysis were applied in exploration of the studied data. Since the data set was affected by outlying objects, the employment of a relevant analysis strategy was necessary. The final PCA model was constructed with the use of the Expectation-Maximization iterative approach preceded by a correct identification of outliers. The analysis of the experimental data indicated that three mine waste dumps located in Poland were characterized by the highest concentrations of dibenzo(g,h,i)anthracene and benzo(g,h,i)perylene, and six objects located in Czech Republic and three objects in Poland were distinguished by high concentrations of chrysene and indeno (1.2.3-cd) pyrene. Three of studied mine waste dumps, one located in Czech Republic and two in Poland, were characterized by low concentrations of Cr, Ni, V, naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthen, benzo(a)anthracene, chrysene, benzo (b) fluoranthene, benzo (k) fluoranthene, benzo(a)pyrene, dibenzo(g,h,i)anthracene, benzo(g,h,i)perylene and indeno (1.2.3-cd) pyrene in comparison with the remaining ones. The analysis contributes to the assessment and prognosis of ecological and health risks related to the emission of trace elements and organic compounds (PAHs) from the waste dumps examined. No previous research of similar scope and aims has been reported for the area concerned. PMID:27497349

  2. A PUBLISHED KINETIC MODEL EXPLAINS THE VARIATION IN NITROGEN CONTENT OF Pichia guilliermondii DURING ITS BATCH CULTIVATION ON DIESEL OIL

    OpenAIRE

    W. BORZANI

    1999-01-01

    Variation in nitrogen content of Pichia guilliermondii during its batch cultivation on media containing diesel oil as the main carbon source may be explained by means of a kinetic model proposed earlier to interpret the kinetics of nitrogen consumption during the process.

  3. A PUBLISHED KINETIC MODEL EXPLAINS THE VARIATION IN NITROGEN CONTENT OF Pichia guilliermondii DURING ITS BATCH CULTIVATION ON DIESEL OIL

    Directory of Open Access Journals (Sweden)

    BORZANI W.

    1999-01-01

    Full Text Available Variation in nitrogen content of Pichia guilliermondii during its batch cultivation on media containing diesel oil as the main carbon source may be explained by means of a kinetic model proposed earlier to interpret the kinetics of nitrogen consumption during the process.

  4. A Simple Beta-Function Model for Soil-Water Repellency as a Function of Water and Organic Carbon Contents

    DEFF Research Database (Denmark)

    Karunarathna, Anurudda Kumara; Kawamoto, Ken; Møldrup, Per;

    2010-01-01

    Soil-water content (θ) and soil organic carbon (SOC) are key factors controlling the occurrence and magnitude of soil-water repellency (WR). Although expressions have recently been proposed to describe the nonlinear variation of WR with θ, the inclusion of easily measurable parameters in predictive...... conditions for 19 soils were used to test the model. The beta function successfully reproduced all the measured soil-water repellency characteristic, α(θ), curves. Significant correlations were found between model parameters and SOC content (1%-14%). The model was independently tested against data...... for further three soils and performed accurately for all three. Consequently, we suggest that the α(θ) model represents a useful strategy to predict the entire soil-water repellency characteristic curve, and thus potential risks for enhanced runoff and preferential (fingered) soil-water flow at given initial...

  5. In Tags We Trust: Trust modeling in social tagging of multimedia content

    OpenAIRE

    Ivanov, Ivan; Vajda, Péter; Lee, Jong Seok; Ebrahimi, Touradj

    2012-01-01

    Tagging in online social networks is very popular these days, as it facilitates search and retrieval of multimedia content. However, noisy and spam annotations often make it difficult to perform an efficient search. Users may make mistakes in tagging and irrelevant tags and content may be maliciously added for advertisement or self-promotion. This article surveys recent advances in techniques for combatting such noise and spam in social tagging. We classify the state-of-the-art approaches int...

  6. Modeling And Forecasting Imported Japanese Parts Content Of US Transplants: An Error Correction And State Space Approach

    OpenAIRE

    Cadogan, Godfrey

    2010-01-01

    This paper provides a sectoral examination of the impact of trade policies and custom valuation procedures on estimating time varying import content of Japanese transplant automobiles. Using monthly data from 1985 to 1992, we introduce an error correction model (ECM) and a state space VAR model to purify trade data of measurement errors induced by unobserveable prices and customs valuation procedures. Data show that US import of Japanese auto parts are elastic to...

  7. Assessment of evapotranspiration and soil water content in the Kysuca River basin (Slovakia) using a rainfall-runoff model

    Czech Academy of Sciences Publication Activity Database

    Košková, Romana; Němečková, Soňa; Sitková, Z.

    2008-01-01

    Roč. 4, č. 1 (2008), s. 012002. ISSN 1755-1315. [Conference of the Danubian Countries /24./. Bled, 02.06.2008-04.06.2008] R&D Projects: GA AV ČR(CZ) KJB300600602 Institutional research plan: CEZ:AV0Z20600510 Keywords : hydrological model ling * soil water content * evapotranspiration * SWIM model Subject RIV: DA - Hydrology ; Limnology http://www.iop.org/EJ/abstract/1755-1315/4/1/012002

  8. Impairment-Factor-Based Audiovisual Quality Model for IPTV: Influence of Video Resolution, Degradation Type, and Content Type

    Directory of Open Access Journals (Sweden)

    Garcia MN

    2011-01-01

    Full Text Available This paper presents an audiovisual quality model for IPTV services. The model estimates the audiovisual quality of standard and high definition video as perceived by the user. The model is developed for applications such as network planning and packet-layer quality monitoring. It mainly covers audio and video compression artifacts and impairments due to packet loss. The quality tests conducted for model development demonstrate a mutual influence of the perceived audio and video quality, and the predominance of the video quality for the overall audiovisual quality. The balance between audio quality and video quality, however, depends on the content, the video format, and the audio degradation type. The proposed model is based on impairment factors which quantify the quality-impact of the different degradations. The impairment factors are computed from parameters extracted from the bitstream or packet headers. For high definition video, the model predictions show a correlation with unknown subjective ratings of 95%. For comparison, we have developed a more classical audiovisual quality model which is based on the audio and video qualities and their interaction. Both quality- and impairment-factor-based models are further refined by taking the content-type into account. At last, the different model variants are compared with modeling approaches described in the literature.

  9. Determination of the moisture content of Nordic spruce wood through cone heater experiments and an integral model

    DEFF Research Database (Denmark)

    Mindykowski, Pierrick Anthony; Jørgensen, M.; Svensson, Staffan; Jomaas, Grunde

    2015-01-01

    The combination of cone heater experiments and an integral model was used to determine the moisture content of Nordic spruce with varying degree of drying. Nine specimens of Nordic spruce were pre-heated to 105°C in a convective oven for durations ranging from 0 days (no drying) and up to 63 days...... ignition temperature (directly linked to the intercept heat flux) was constant for dry and wet wood pieces. Furthermore, from this result and the high-flux asymptotic solution, the fuel moisture content of the wet specimen was calculated and found to be very close to the measured value. As a result, one...

  10. Two-Region Model for Soil Water Repellency as a Function of Matric Potential and Water Content

    DEFF Research Database (Denmark)

    Karunarathna, A. K.; Møldrup, Per; Kawamoto, K.;

    2010-01-01

    Soil water repellency (WR) occurs worldwide and affects hydrologic processes such as infiltration, preferential flow, and surface erosion. The degree of WR varies with soil organic C (SOC) and water contents. In this study, we measured WR (by ethanol molarity) as a function of moisture conditions...... for two soil profiles (17 layers, of which 13 exhibited WR), representing different vegetation and SOC between 0.6 and 14%. Generally, WR was found at SOC ≥2%. Based on measured data, a two-region water repellency (TRWR) model was developed. The model assumes two linear regions in a WR vs. pF (=log...... by the so-called Dexter index) is useful for predicting if soils are likely to exhibit WR. Expression of soil water repellency depends on soil water content; however, only a limited amount of predictive description is available to date. In this study, based on experimental data, a simple two-region model...

  11. Detection of water content inhomogeneities in a dike model using invasive GPR guided wave sounding and TRIME-TDR® technique

    International Nuclear Information System (INIS)

    Guided wave sounding (GWS), an invasive application of ground-penetrating radar (GPR), and time domain reflectometry with intelligible micro elements (TRIME-TDR®) were used to investigate the distribution of volumetric water content (VWC) in a dike model under controlled conditions in order to detect possible dike damage. The dike model, which was constructed with soil of the texture class loamy sand, was flooded at different levels of water between 0.3 and 1.25 m high from a waterproof baseline. The two techniques were applied to retrieve VWC information from the same location at the crest of the dike model. Both techniques assessed reflection data from the lower end of a metal probe lowered through a common access borehole and successfully detected a water content inhomogeneity in the model at a depth of about 0.6 m from the crest. Comparison of the colocated VWC measurements from the two techniques showed almost identical trends with a root mean square deviation of 0.018 m3 m−3. GWS, however, showed a much higher depth resolution than TRIME-TDR®. Accompanying analytical and numerical modelling show that GWS sounding should be applicable to water content exploration in existing, 10–20 m deep boreholes. (paper)

  12. Discovering Plate Boundaries Update: Builds Content Knowledge and Models Inquiry-based Learning

    Science.gov (United States)

    Sawyer, D. S.; Pringle, M. S.; Henning, A. T.

    2009-12-01

    Discovering Plate Boundaries (DPB) is a jigsaw-structured classroom exercise in which students explore the fundamental datasets from which plate boundary processes were discovered. The exercise has been widely used in the past ten years as a classroom activity for students in fifth grade through high school, and for Earth Science major and general education courses in college. Perhaps more importantly, the exercise has been used extensively for professional development of in-service and pre-service K-12 science teachers, where it simultaneously builds content knowledge in plate boundary processes (including natural hazards), models an effective data-rich, inquiry-based pedagogy, and provides a set of lesson plans and materials which teachers can port directly into their own classroom (see Pringle, et al, this session for a specific example). DPB is based on 4 “specialty” data maps, 1) earthquake locations, 2) modern volcanic activity, 3) seafloor age, and 4) topography and bathymetry, plus a fifth map of (undifferentiated) plate boundary locations. The jigsaw is structured so that students are first split into one of the four “specialties,” then re-arranged into groups with each of the four specialties to describe the boundaries of a particular plate. We have taken the original DPB materials, used the latest digital data sets to update all the basic maps, and expanded the opportunities for further student and teacher learning. The earthquake maps now cover the recent period including the deadly Banda Aceh event. The topography/bathymetry map now has global coverage and uses ice-free elevations, which can, for example, extend to further inquiry about mantle viscosity and loading processes (why are significant portions of the bedrock surface of Greenland and Antarctica below sea level?). The volcanic activity map now differentiates volcano type and primary volcanic lithology, allowing a more elaborate understanding of volcanism at different plate boundaries

  13. Photochemistry in Saturn's Ring-Shadowed Atmosphere: Modeling of Key Molecules and Observations of Dust Content

    Science.gov (United States)

    Edgington, S. G.; Atreya, S. K.; Wilson, E. H.; West, R. A.; Fletcher, L. N.; Baines, K. H.; Bjoraker, G. L.; Momary, T.

    2014-12-01

    Cassini has been orbiting Saturn for over ten years now. During this epoch, the ring shadow has moved from covering a large portion of the northern hemisphere to covering a large swath south of the equator and continues to move southward. At Saturn Orbit Insertion in 2004, the ring plane was inclined by ~24 degrees relative to the Sun-Saturn vector. The projection of the B-ring onto Saturn reached as far as 40N along the central meridian (~52N at the terminator). At its maximum extent, the ring shadow can reach as far as 48N/S (~58N/S at the terminator). The net effect is that the intensity of both ultraviolet and visible sunlight penetrating into any particular latitude will vary depending on both Saturn's axis relative to the Sun and the optical thickness of each ring system. In essence, the rings act like venetian blinds. Our previous work [1] examined the variation of the solar flux as a function of solar inclination, i.e. ~7.25 year season at Saturn. Here, we report on the impact of the oscillating ring shadow on the photolysis and production rates of hydrocarbons in Saturn's stratosphere and upper troposphere, including acetylene, ethane, propane, and benzene. Beginning with methane, we investigate the impact on production and loss rates of the long-lived photochemical products leading to haze formation are examined at several latitudes over a Saturn year. Similarly, we assess its impact on phosphine abundance, a disequilibrium species whose presence in the upper troposphere is a tracer of convective processes in the deep atmosphere. We will also present our ongoing analysis of Cassini's CIRS, UVIS, and VIMS datasets that provide an estimate of the evolving haze content of the northern hemisphere and we will begin to assess the implications for dynamical mixing. In particular, we will examine how the now famous hexagonal jet stream acts like a barrier to transport, isolating Saturn's north polar region from outside transport of photochemically

  14. Systematized Water content Calculation in Cartilage Using T1-mapping MR Estimations. Design of a Mathematical Model

    DEFF Research Database (Denmark)

    Shiguetomi Medina, Juan Manuel; Ramirez Garcia-Luna, Jose Luis; Rahbek, Ole;

    .5 Tesla by calculating absolute T1 values in real maps through inverse angle phase inverse sequence recuperation (11 inversion times, from 200 to 2200 msec) at 37(±0.5) °C. Regions of interest were manually delineated and the mean T1 value was estimated using a T1-map analysis software. The collected data...... absolute T1 values in real maps and inverse sequence recuperation by the equation Water Content = (0.476 + T1 Signal Intensity * 0.000193) * 100. Conclusions It is possible to calculate water content in a tissue using absolute T1-values from MR. This technology allows quantification of disease...... described. Purpose/Aim of Study Development of a mathematical model to measure the water content in tissue using T1-values obtained from MR. Materials and Methods T-1 values were obtained from 45 samples from tissue-mimicking gelatin with previously known water concentrations. We analyzed the samples in a 1...

  15. Furosemide modifies heart hypertrophy and glycosaminoglycan myocardium content in a rat model of neurogenic hypertension.

    Science.gov (United States)

    Pourzitaki, Chryssa; Tsaousi, Georgia; Manthou, Maria Eleni; Karakiulakis, Georgios; Kouvelas, Dimitrios; Papakonstantinou, Eleni

    2016-08-01

    Hypertension is a major risk factor for atherogenesis and heart hypertrophy, both of which are associated with specific morphological and functional changes of the myocardium. Glycosaminoglycans (GAGs) are complex molecules involved both in tissue morphology and function. In the present study, we investigated the effects of neurogenic hypertension and subsequent antihypertensive treatment with furosemide, on heart hypertrophy and the content of GAGs in the myocardium. Neurogenic hypertension was achieved in male Wistar rats by bilateral aortic denervation (bAD). At days 2, 7 and 15 after surgery, animals were sacrificed and the hearts were dissected away, weighted, and homogenized. Total GAGs were assessed by measuring the uronic acid content colorimetrically and individual GAGs were isolated and characterized by enzymatic treatment, with GAG-degrading enzymes, using electrophoresis on polyacrylamide gradient gels and cellulose acetate membranes. In bAD-animals blood pressure, blood pressure lability, heart rate and heart weight were significantly increased 15 days postoperatively. These effects were prevented by treatment with furosemide. Major GAGs identified in the heart were chondroitin sulphates, heparin (H), heparan sulphate (HS) and hyaluronic acid. The content of uronic and the relative content of H and HS in the heart in bAD animals significantly decreased from day 2 to day 15 postoperatively. Furosemide prevented the bAD induced decrease in GAG content. Considering that H and HS are potent inhibitors of cardiomyocyte hypertrophy, our results indicate that heart hypertrophy induced by neurogenic hypertension may be associated with decreases in the relative content of heparin and heparan sulphate in the heart. PMID:27221775

  16. The carcinogenic risks of low-LET and high-LET ionizing radiations

    International Nuclear Information System (INIS)

    This report presents a discussion on risk from ionizing radiations to human populations. Important new information on human beings has come mainly from further follow-up of existing epidemiological studies, notably the Japanese atomic bomb survivors and the ankylosing spondylitis patients; from new epidemiological surveys, such as the patients treated for cancer of the uterine cervix; and from combined surveys, including workers exposed in underground mines. Since the numerous and complex differences among the different study populations introduce factors that influence the risk estimates derived in ways that are not completely understood, it is not clear how to combine the different risk estimates obtained. These factors involve complex biological and physical variables distributed over time. Because such carcinogenic effects occur too infrequently to be demonstrated at low doses, the risks of low-dose radiation can be estimated only by interpolation from observations at high doses on the basis of theoretical concepts, mathematical models and available empirical evidence, primarily the epidemiological surveys of large populations exposed to ionizing radiation. In spite of a considerable amount of research, only recently has there has been efforts to apply the extensive laboratory data in animals to define the dose-incidence relationship in the low dose region. There simply are insufficient data in the epidemiological studies of large human populations to estimate risk coefficients directly from exposure to low doses. The risk estimates for the carcinogenic effects of radiation have been, in the past, somewhat low and reassessment of the numerical values is now necessary

  17. Preferential binding of growth inhibitory prostaglandins by the target protein of a carcinogen

    Energy Technology Data Exchange (ETDEWEB)

    Khan, S.H.; Sorof, S. (Fox Chase Cancer Center, Philadelphia, PA (United States))

    1990-12-01

    Liver fatty acid binding protein (L-FABP) is the principal target protein of the hepatic carcinogen N-(2-fluorenyl)acetamide (2-acetylaminofluorene) in rat liver. In addition, the cyclopentenone prostaglandins (PG), PGA, PGJ{sub 2}, and {Delta}{sup 12}-PGJ{sub 2}, inhibit the growth of many cell types in vitro. This report describes the preferential binding of the growth inhibitory prostaglandins by L-FABP and the reversible inhibition of thymidine incorporation into DNA by PGA{sub 2} and {Delta}{sup 12}-PGJ{sub 2} in primary cultures of purified rat hepatocytes. As a model ligand, ({sup 3}H)PGA{sub 1} bound to L-FABP specifically, reversibly, rapidly, and with high affinity. Its dissociation constants were 134 nM (high affinity) and 3.6 {mu}M (low affinity). The high-affinity finding of ({sup 3}H)PGA{sup 1} correlated with their growth inhibitory activities reported previously and here. The in vitro actions of L-FABP are compatible with those of a specific and dissociable carrier of growth inhibitory prostaglandins in rat hepatocytes and suggest that the carcinogen may usurp the cellular machinery of the growth inhibitory prostaglandins.

  18. Preferential binding of growth inhibitory prostaglandins by the target protein of a carcinogen

    International Nuclear Information System (INIS)

    Liver fatty acid binding protein (L-FABP) is the principal target protein of the hepatic carcinogen N-(2-fluorenyl)acetamide (2-acetylaminofluorene) in rat liver. In addition, the cyclopentenone prostaglandins (PG), PGA, PGJ2, and Δ12-PGJ2, inhibit the growth of many cell types in vitro. This report describes the preferential binding of the growth inhibitory prostaglandins by L-FABP and the reversible inhibition of thymidine incorporation into DNA by PGA2 and Δ12-PGJ2 in primary cultures of purified rat hepatocytes. As a model ligand, [3H]PGA1 bound to L-FABP specifically, reversibly, rapidly, and with high affinity. Its dissociation constants were 134 nM (high affinity) and 3.6 μM (low affinity). The high-affinity finding of [3H]PGA1 correlated with their growth inhibitory activities reported previously and here. The in vitro actions of L-FABP are compatible with those of a specific and dissociable carrier of growth inhibitory prostaglandins in rat hepatocytes and suggest that the carcinogen may usurp the cellular machinery of the growth inhibitory prostaglandins

  19. Research on the Estimation Model of Soil Moisture Content Based on the Characteristics of Thermal Infrared Data

    Institute of Scientific and Technical Information of China (English)

    Jun; XU; Jianjun; JIANG

    2013-01-01

    With the portable Fourier Transform Infrared Spectroscopy (FTIR), the reflectance spectra of soil samples with different moisture content are measured in laboratory for expounding the characteristic of radiation in the thermal infrared part of the spectrum with different soil moisture content. A model of estimating the moisture content in soil is attempted to make based on Moisture Diagnostic Index (MDI). In general,the spectral characteristic of soil emissivity in laboratory includes the following aspects.Firstly,in the region of 8.0-9.5 μm,along with the increase of soil moisture content,the emissivity of soil increases to varying degrees. The spectral curves are parallel relatively and have a tendency to become horizontal and the absorbed characteristic of reststrahlen is also weakened relatively with the increase of soil moisture in this region.Secondly,in the region of 11.0-14.0 μm,the emissivity of soil has a tendency of increasing.There is an absorption value near about 12.7 μm. As the soil moisture content increases,the depth of absorption also increases. This phenomenon may be caused by soil moisture absorption. Methods as derivative, difference and standardized ratio transformation may weaken the background noise effectively to the spectrum data. Especially using the ratio of the emissivity to the average of 8-14 μm may obviously enhance the correlation between soil moisture and soil emissivity. According to the result of correlation analysis, the 8.237 μm is regarded as the best detecting band for soil moisture content. Moreover,based on the Moisture Diagnostic Index ( MDI) in the 8.194-8.279 μm, the logarithmic model of estimating soil moisture is made.

  20. A method for identifying optimum strategies of measuring soil water contents for calibrating a root water uptake model

    Science.gov (United States)

    Musters, P. A. D.; Bouten, W.

    2000-01-01

    Measurements of soil water contents, such as with Time Domain Reflectometry (TDR) are essential to calibrate models that estimate the vertical distribution of root water uptake by simulating the unsaturated flow of soil water. This study presents a method to determine how the number of TDR probes used, their orientation and depth of installation affect uncertainties in calibrating a Root Water Uptake Model (SWIF); thus the suggested method identifies optimal placement of TDR sensors for the calibration of a root water uptake model. Our approach is based on estimating efficiencies of different monitoring strategies with the help of a data set of 3000 simulations with different parameter sets. Parameter sets are accepted if simulations reproduced the 'measured' soil water dynamics of a reference run at specific depths within an accuracy of 0.01 m 3 m -3; a value representing acceptable error intervals in measured soil water contents. The smaller the number of simulations that meet this criterion, the more information measured soil water dynamics contain to identify model parameters and thus the more effective a measurement strategy for model calibration. The presented method is illustrated with results for a pine stand on a sandy soil with a rooting depth of 1.5 m. For this situation, uncertainties in simulated water contents are already less than 0.01 m 3 m -3 if SWIF is calibrated against measurements with a relatively small number (5) of TDR probes installed horizontally. Installation depths are critical when using a lower number of probes. Vertical profiles of measured soil water contents, measured with non-automated techniques, are as well effective for model calibration, especially in combination with measurements from permanently installed TDR probes. These profiles contain most information for model calibration if measured 5 days after a clear rain fall event preceded by a dry period of 20 days or more with a relatively high water demand. Uncertainty

  1. Effect of Radiation on the Functions of Carcinogenic Viruses

    International Nuclear Information System (INIS)

    When carcinogenic viruses are irradiated under suitable experimental conditions with ultra-violet rays or ionizing radiation, the various viral functions can be dissociated and virions defective in certain functions can be obtained. These defects are real mutations; they are passed on to subsequent generations provided the virions affected remain capable of reproduction. It has been possible to obtain various types of mutant, e.g. hyper producers of virions, non-productive transformers, non-transforming producers. The production of these mutants opens up certain experimental possibilities with regard to the transformation mechanism and the possible consequences of irradiation in vivo. Attention will be devoted in particular to the increased oncogenic capability in vivo which is sometimes observed in pre-irradiated viruses, and also to the consequences of this effect in the radiotherapy of certain malignant infections. These studies are also of interest for analysing the structure of the viral genome and throwing light on that fraction of the genome which is responsible for the transforming capacity. In the case of small viruses with a single DNA molecule (polyoma, SV-40) it has been possible to measure the fraction of the molecule responsible for the transforming capacity. In the case of the Rous virus the experiments suggest that the viral RNA is made up of sub-units capable of independent replication, the transforming capacity being possessed by only one of these sub-units. The induced defect may reveal the presence of transforming capacity in a virus considered as non- oncogenic because the transformed cells are usually eliminated by the infective process. In this way irradiation could render carcinogenic a virus which is not carcinogenic under normal conditions. The paper covers work done at the various viral radiobiology laboratories of the Radium Institute during the last two years. (author)

  2. An extension of the talbot-ogden hydrology model to an affine multi-dimensional moisture content domain

    KAUST Repository

    Yu, Han

    2013-09-01

    The Talbot-Ogden hydrology model provides a fast mass conservative method to compute infiltration in unsaturated soils. As a replacement for a model based on Richards equation, it separates the groundwater movement into infiltration and redistribution for every time step. The typical feature making this method fast is the discretization of the moisture content domain rather than the spatial one. The Talbot-Ogden model rapidly determines how well ground water and aquifers are recharged only. Hence, it differs from models based on advanced reservoir modeling that are uniformly far more expensive computationally since they determine where the water moves in space instead, a completely different and more complex problem.According to the pore-size distribution curve for many soils, this paper extends the one dimensional moisture content domain into a two dimensional one by keeping the vertical spatial axis. The proposed extension can describe any pore-size or porosity distribution as an important soil feature. Based on this extension, infiltration and redistribution are restudied. The unconditional conservation of mass in the Talbot-Ogden model is inherited in this extended model. A numerical example is given for the extended model.

  3. Carcinogen-Specific Gene Expression Profiles in Short-term Treated Eker and Wild-type Rats Indicative of Pathways Involved in Renal Tumorigenesis

    OpenAIRE

    Stemmer, Kerstin; Ellinger-Ziegelbauer, Heidrun; Ahr, Hans-Jürgen; Dietrich, Daniel R

    2007-01-01

    Eker rats heterozygous for a dominant germline mutation in the tuberous sclerosis 2 (Tsc2) tumor suppressor gene were used as a model to study renal carcinogenesis. Eker and corresponding wild-type rats were exposed to genotoxic aristolochic acid (AA) or non-genotoxic ochratoxin A (OTA) to elucidate early carcinogen-specific gene expression changes and to test whether Eker rats are more sensitive to carcinogen-induced changes in gene expression. Male Eker and wild-type rats were gavaged daily...

  4. Precipitable water vapour contents at "local" scale: a comparative study on GNSS-derived data versus modelled ones from ECMWF operational models

    Science.gov (United States)

    Riccardi, Umberto; Tammaro, Umberto; Boy, Jean-Paul; Masson, Frederic; Capuano, Paolo

    2016-04-01

    We present a comparative study between GNSS-derived precipitable water (PW) contents and modelled data from ECMWF operational models. Nearly 4 years of PW contents derived from meteorological and GNSS data are analyzed. We use GNSS data from a geodetic monitoring network of the Neapolitan active volcanoes managed by INGV as well as from some GPS stations installed on purpose. We compare PW time series retrieved from GNSS observations with those coming from models. The total water vapour content of the atmosphere can be derived by modelling from the vertical profile of the specific humidity. We use ECMWF operational models available at a horizontal resolution of about 15 km, 3-hourly samples. The number of vertical model levels is 91 up to mid 2013 and 137 afterwards. We recomputed the surface pressure on the real Earth surface, which differs from the orography, i.e. the smooth surface of the atmospheric model, by propagating the pressure from the orography to the surface. A very good agreement is achieved between PW retrieved from GNSS observations and computed from models using the highest time and space resolution (0.15 degree, 3-hourly 91-137 layers) operational models. We even focus our analysis on the occasion of some extreme raining events hitting Campania region (Italy).

  5. Population variability in biological adaptive responses to DNA damage and the shapes of carcinogen dose-response curves

    International Nuclear Information System (INIS)

    Carcinogen dose-response curves for both ionizing radiation and chemicals are typically assumed to be linear at environmentally relevant doses. This assumption is used to ensure protection of the public health in the absence of relevant dose-response data. A theoretical justification for the assumption has been provided by the argument that low dose linearity is expected when an exogenous agent adds to an ongoing endogenous process. Here, we use computational modeling to evaluate (1) how two biological adaptive processes, induction of DNA repair and cell cycle checkpoint control, may affect the shapes of dose-response curves for DNA-damaging carcinogens and (2) how the resulting dose-response behaviors may vary within a population. Each model incorporating an adaptive process was capable of generating not only monotonic dose-responses but also nonmonotonic (J-shaped) and threshold responses. Monte Carlo analysis suggested that all these dose-response behaviors could coexist within a population, as the spectrum of qualitative differences arose from quantitative changes in parameter values. While this analysis is largely theoretical, it suggests that (a) accurate prediction of the qualitative form of the dose-response requires a quantitative understanding of the mechanism (b) significant uncertainty is associated with human health risk prediction in the absence of such quantitative understanding and (c) a stronger experimental and regulatory focus on biological mechanisms and interindividual variability would allow flexibility in regulatory treatment of environmental carcinogens without compromising human health

  6. Rhetorical Savvy as Social Skill: Modeling Entrepreneur Identity Construction within Educational Content Management Systems

    Science.gov (United States)

    Spartz, John M.

    2010-01-01

    This article focuses on one aspect of rhetorical training that writing instructors have an opportunity--if not an obligation--to inculcate (or at least introduce) in students studying to be entrepreneurs and taking their writing classes. Specifically, through the use of an open source Content Management System (CMS) (e.g., Drupal or Moodle),…

  7. Modeling the Physical Properties of Popcorn Varieties as a Function of Kernel Moisture Content

    Directory of Open Access Journals (Sweden)

    Koyejo ODUOLA

    2011-06-01

    Full Text Available The physical properties such as the axial dimensions (length, width, thickness, geometric mean diameter, thousand kernel weight, shape characteristics (sphericity, kernel volume, kernel surface area, bulk density, particle or kernel density, as well as porosity have been evaluated as a function of kernel moisture content for “pin” and “deep” yellow varieties of Nigerian popcorn kernels. It has been observed that the length, width, thickness as well as the thousand kernel weight increase with increasing moisture content for both varieties under investigation in the moisture range 11-17% (wet basis., while the bulk and particle densities together with the kernel porosity have been found to decrease with increasing moisture content. These physical properties vs moisture content dependencies have been fitted to linear, polynomial and other non-linear equations and the empirical constants determined for each case. Regression analyses have revealed that the third-order polynomial and quadratic functions more adequately describe the observed dependencies than the linear equation in most cases, based on the resulting correlation coefficients and standard errors.

  8. Technology-Based Content through Virtual and Physical Modeling: A National Research Study

    Science.gov (United States)

    Ernst, Jeremy V.; Clark, Aaron C.

    2009-01-01

    Visualization is becoming more prevalent as an application in science, engineering, and technology related professions. The analysis of static and dynamic graphical visualization provides data solutions and understandings that go beyond traditional forms of communication. The study of technology-based content and the application of conceptual…

  9. Assessment of evapotranspiration and soil water content in the Kysuca River basin (Slovakia) using a rainfall-runoff model

    International Nuclear Information System (INIS)

    Rainfall-runoff modelling is a commonly-used tool for analysis of various aspects of hydrological research. An application of the distributed hydrological model brings the benefits of assessment to the spatially distributed results. Description of the spatial distribution of soil and vegetation types is an essential task and substantially influences the accuracy of the results. The Kysuca River basin has been chosen for an evaluation of soil water content and evapotranspiration by a distributed hydrological model, SWIM (Soil and Water Integrated Model). The primary interest in this analysis was motivated by assessment of forest health conditions in the area and finding possible causes of forest deterioration. Evapotranspiration and soil water content in two selected soil layers in each hydrotop have been evaluated in a simulation period, 1995-1999. A set of maps each representing an individual day of the simulation period has been obtained as a result of the simulation for each variable mentioned above. The simulation has also been carried out for 2007, when the results for selected hydrotops were statistically processed and compared with the available observed data measured during the field survey. Nevertheless, the comparison is affected by the fact that the tensometers have not yet been calibrated to the local conditions. The resulting uncertainties had to be taken into account. The main trends of the simulated and measured soil water content have been evaluated and assessed as satisfactory.

  10. Transplacental carcinogenicity of inorganic arsenic in the drinking water: induction of hepatic, ovarian, pulmonary, and adrenal tumors in mice

    International Nuclear Information System (INIS)

    Arsenic is a known human carcinogen, but development of rodent models of inorganic arsenic carcinogenesis has been problematic. Since gestation is often a period of high sensitivity to chemical carcinogenesis, we performed a transplacental carcinogenicity study in mice using inorganic arsenic. Groups (n=10) of pregnant C3H mice were given drinking water containing sodium arsenite (NaAsO2) at 0 (control), 42.5, and 85 ppm arsenite ad libitum from day 8 to 18 of gestation. These doses were well tolerated and body weights of the dams during gestation and of the offspring subsequent to birth were not reduced. Dams were allowed to give birth, and offspring were weaned at 4 weeks and then put into separate gender-based groups (n=25) according to maternal exposure level. The offspring received no additional arsenic treatment. The study lasted 74 weeks in males and 90 weeks in females. A complete necropsy was performed on all mice and tissues were examined by light microscopy in a blind fashion. In male offspring, there was a marked increase in hepatocellular carcinoma incidence in a dose- related fashion (control, 12%; 42.5 ppm, 38%; 85 ppm, 61%) and in liver tumor multiplicity (tumors per liver; 5.6-fold over control at 85 ppm). In males, there was also a dose-related increase in adrenal tumor incidence and multiplicity. In female offspring, dose-related increases occurred in ovarian tumor incidence (control, 8%; 42.5 ppm, 26%; 85 ppm, 38%) and lung carcinoma incidence (control, 0%; 42.5 ppm, 4%; 85 ppm, 21%). Arsenic exposure also increased the incidence of proliferative lesions of the uterus and oviduct. These results demonstrate that oral inorganic arsenic exposure, as a single agent, can induce tumor formation in rodents and establishes inorganic arsenic as a complete transplacental carcinogen in mice. The development of this rodent model of inorganic arsenic carcinogenesis has important implications in defining the mechanism of action for this common environmental

  11. Results of screening NCI/NTP nongenotoxic carcinogens and genotoxic noncarcinogens with the ke test

    International Nuclear Information System (INIS)

    The interdependence of the electrophilic and carcinogenic properties of chemicals that was demonstrated two decades ago rekindled interest in the somatic mutation theory of carcinogenesis. Interest in this theory grew with the development of a reverse-mutation bacterial assay in the laboratory of B.N. Ames that permitted the mutagenic properties of the chemicals to be determined quickly and yielded results which indicated that ''carcinogens are mutagens.'' Subsequent validation studies of this bioassay, the Salmonella typhimurium/microsome or ''Ames test,'' by Ames' group and others provided additional support for the correlation between mutagenicity and carcinogenicity which led to the worldwide deployment of the Ames test in thousands of laboratories and to the development of more than 100 other short-term tests that continue to be used to identify potential carcinogens via various end-points of genotoxicity. This document discusses electrophilicity, mutagenicity, and carcinogenicity relationships as well as carcinogen-screening of chemicals. 28 refs., 4 tabs

  12. An Accurate Analytical Model for 802.11e EDCA under Different Traffic Conditions with Contention-Free Bursting

    Directory of Open Access Journals (Sweden)

    Nada Chendeb Taher

    2011-01-01

    Full Text Available Extensive research addressing IEEE 802.11e enhanced distributed channel access (EDCA performance analysis, by means of analytical models, exist in the literature. Unfortunately, the currently proposed models, even though numerous, do not reach this accuracy due to the great number of simplifications that have been done. Particularly, none of these models considers the 802.11e contention free burst (CFB mode which allows a given station to transmit a burst of frames without contention during a given transmission opportunity limit (TXOPLimit time interval. Despite its influence on the global performance, TXOPLimit is ignored in almost all existing models. To fill in this gap, we develop in this paper a new and complete analytical model that (i reflects the correct functioning of EDCA, (ii includes all the 802.11e EDCA differentiation parameters, (iii takes into account all the features of the protocol, and (iv can be applied to all network conditions, going from nonsaturation to saturation conditions. Additionally, this model is developed in order to be used in admission control procedure, so it was designed to have a low complexity and an acceptable response time. The proposed model is validated by means of both calculations and extensive simulations.

  13. Discrimination of Carcinogens by Hepatic Transcript Profiling in Rats Following 28-day Administration

    Directory of Open Access Journals (Sweden)

    Hiroshi Matsumoto

    2009-11-01

    Full Text Available This study aimed at discriminating carcinogens on the basis of hepatic transcript profiling in the rats administrated with a variety of carcinogens and non-carcinogens. We conducted 28-day toxicity tests in male F344 rats with 47 carcinogens and 26 non- carcinogens, and then investigated periodically the hepatic gene expression profiles using custom microarrays. By hierarchical cluster analysis based on significantly altered genes, carcinogens were clustered into three major groups (Group 1 to 3. The formation of these groups was not affected by the gene sets used as well as the administration period, indicating that the grouping of carcinogens was universal independent of the conditions of both statistical analysis and toxicity testing. Seventeen carcinogens belonging to Group 1 were composed of mainly rat hepatocarcinogens, most of them being mutagenic ones. Group 2 was formed by three subgroups, which were composed of 23 carcinogens exhibiting distinct properties in terms of genotoxicity and target tissues, namely nonmutagenic hepatocarcinogens, and mutagenic and nonmutagenic carcinogens both of which are targeted to other tissues. Group 3 contained 6 carcinogens including 4 estrogenic substances, implying the group of estrogenic carcinogens. Gene network analyses revealed that the significantly altered genes in Group 1 included Bax, Tnfrsf6, Btg2, Mgmt and Abcb1b, suggesting that p53-mediated signaling pathway involved in early pathologic alterations associated with preceding mutagenic carcinogenesis. Thus, the common transcriptional signatures for each group might reflect the early molecular events of carcinogenesis and hence would enable us to identify the biomarker genes, and then to develop a new assay for carcinogenesis prediction.

  14. Model for estimation of Sr-90 content in the population of West Java through consumption of fresh milk

    International Nuclear Information System (INIS)

    A simple model for estimation of Sr-90 content in the critical organ of West Java population was developed. By using this model and data of the average consumption of fresh milk and the average concentration of Sr-90 in fresh milk produced in this area it was found that the average content of Sr-90 in critical organ of this population had a value of 220 Bq (=6.0 nCi). This value was lower than the allowable maximum concentration of Sr-90 in critical organ which has a value of 7.4x104 Bq (=2 uCi). Therefore, it is concluded that milk is not an important food item for the Sr-90 pathway to the population. (author). 11 refs

  15. Improving Global Models of Remotely Sensed Ocean Chlorophyll Content Using Partial Least Squares and Geographically Weighted Regression

    Science.gov (United States)

    Gholizadeh, H.; Robeson, S. M.

    2015-12-01

    Empirical models have been widely used to estimate global chlorophyll content from remotely sensed data. Here, we focus on the standard NASA empirical models that use blue-green band ratios. These band ratio ocean color (OC) algorithms are in the form of fourth-order polynomials and the parameters of these polynomials (i.e. coefficients) are estimated from the NASA bio-Optical Marine Algorithm Data set (NOMAD). Most of the points in this data set have been sampled from tropical and temperate regions. However, polynomial coefficients obtained from this data set are used to estimate chlorophyll content in all ocean regions with different properties such as sea-surface temperature, salinity, and downwelling/upwelling patterns. Further, the polynomial terms in these models are highly correlated. In sum, the limitations of these empirical models are as follows: 1) the independent variables within the empirical models, in their current form, are correlated (multicollinear), and 2) current algorithms are global approaches and are based on the spatial stationarity assumption, so they are independent of location. Multicollinearity problem is resolved by using partial least squares (PLS). PLS, which transforms the data into a set of independent components, can be considered as a combined form of principal component regression (PCR) and multiple regression. Geographically weighted regression (GWR) is also used to investigate the validity of spatial stationarity assumption. GWR solves a regression model over each sample point by using the observations within its neighbourhood. PLS results show that the empirical method underestimates chlorophyll content in high latitudes, including the Southern Ocean region, when compared to PLS (see Figure 1). Cluster analysis of GWR coefficients also shows that the spatial stationarity assumption in empirical models is not likely a valid assumption.

  16. How well can in vitro data predict in vivo effects of chemicals? Rodent carcinogenicity as a case study.

    Science.gov (United States)

    Anthony Tony Cox, Louis; Popken, Douglas A; Kaplan, A Michael; Plunkett, Laura M; Becker, Richard A

    2016-06-01

    A recent research article by the National Center for Computational Toxicology (NCCT) (Kleinstreuer et al., 2013), indicated that high throughput screening (HTS) data from assays linked to hallmarks and presumed pathways of carcinogenesis could be used to predict classification of pesticides as either (a) possible, probable or likely rodent carcinogens; or (b) not likely carcinogens or evidence of non-carcinogenicity. Using independently developed software to validate the computational results, we replicated the majority of the results reported. We also found that the prediction model correlating cancer pathway bioactivity scores with in vivo carcinogenic effects in rodents was not robust. A change of classification of a single chemical in the test set was capable of changing the overall study conclusion about the statistical significance of the correlation. Furthermore, in the subset of pesticide compounds used in model validation, the accuracy of prediction was no better than chance for about three quarters of the chemicals (those with fewer than 7 positive outcomes in HTS assays representing the 11 histopathological endpoints used in model development), suggesting that the prediction model was not adequate to predict cancer hazard for most of these chemicals. Although the utility of the model for humans is also unclear because a number of the rodent responses modeled (e.g., mouse liver tumors, rat thyroid tumors, rat testicular tumors, etc.) are not considered biologically relevant to human responses, the data examined imply the need for further research with HTS assays and improved models, which might help to predict classifications of in vivo carcinogenic responses in rodents for the pesticide considered, and thus reduce the need for testing in laboratory animals. PMID:26879462

  17. On the Prediction of Addiction Potential Based on Family Process and Content Model in High School Students

    OpenAIRE

    hadi salimi; shiva gohari; Fatemeh Kermanshahi; Mousa Javdan

    2015-01-01

    Objective: This study was an attempt to predict addiction potential based on family process and content model in high school students. Method: The research method in this study was a descriptive-correlational one. All the high school students of Karaj city in the academic year 2012-2013 constituted the statistical population of the study. From this population, the number of 410 participants was selected through random cluster sampling. The research instruments here included Addiction Potentia...

  18. Ochratoxin A carcinogenicity involves a complex network of epigenetic mechanisms.

    Science.gov (United States)

    Marin-Kuan, Maricel; Cavin, Christophe; Delatour, Thierry; Schilter, Benoît

    2008-08-01

    Ochratoxin A (OTA) is a mycotoxin occurring in a wide range of food products. Because of the limitation of human epidemiological data, the safety significance of OTA in food has to rely on animal data, with renal toxicity and carcinogenicity being considered the pivotal effects. The elucidation of the mechanism of action would improve the use of experimental animal data for risk assessment. Direct genotoxicity versus epigenetic mechanisms appears to be a key question. In the present review, the increasingly documented epigenetic cellular effects of OTA and their potential toxicological relevance are discussed. The information available suggests that OTA is unlikely to act through a single, well-defined mechanism of action. Instead, it is proposed that a network of interacting epigenetic mechanisms, including protein synthesis inhibition, oxidative stress and the activation of specific cell signalling pathways, is responsible for OTA carcinogenicity. From a risk assessment perspective, it has to be noted that the mechanisms proposed above depend mainly upon gene expression and enzyme activation, and are, therefore, likely to be thresholded. PMID:18649906

  19. Carcinogenic effects ofcircadian disruption:an epigenetic viewpoint

    Institute of Scientific and Technical Information of China (English)

    Abbas Salavaty

    2015-01-01

    Circadian rhythms refer to the endogenous rhythms that are generated to synchronize physiology and behavior with 24-h environmental cues. These rhythms are regulated by both external cues and molecular clock mechanisms in almost all cells. Disruption of circadian rhythms, which is called circadian disruption, affects many biological processes within the body and results in different long-term diseases, including cancer. Circadian regulatory pathways result in rhythmic epigenetic modiifcations and the formation of circadian epigenomes. Aberrant epigenetic modiifcations, such as hypermethylation, due to circadian disruption may be involved in the transformation of normal cells into cancer cells. Several studies have indicated an epigenetic basis for the carcinogenic effects of circadian disruption. In this review, I ifrst discuss some of the circadian genes and regulatory proteins. Then, I summarize the current evidence related to the epigenetic modiifcations that result in circadian disruption. In addition, I explain the carcinogenic effects of circadian disruption and highlight its potential role in different human cancers using an epigenetic view-point. Finally, the importance of chronotherapy in cancer treatment is highlighted.

  20. Review of genotoxicity and rat carcinogenicity investigations with astaxanthin.

    Science.gov (United States)

    Edwards, James A; Bellion, Phillip; Beilstein, Paul; Rümbeli, Robert; Schierle, Joseph

    2016-03-01

    Synthetic astaxanthin has been extensively tested for safety. Genotoxicity studies including Ames and in vitro Micronucleus Tests show absence of genotoxic potential. Although a long-term mouse study showed no carcinogenicity potential, the rat carcinogenicity study with dietary dosages of 0 (control), 0 (placebo beadlet), 40, 200 and 1000 mg astaxanthin/kg bw/day showed an increased incidence of benign, hepatocellular adenoma in females only, at 200 mg/kg bw/day and above. There was no clear evidence of toxicity during the in-life phase. Discoloration of feces was observed and a reduction in body weight gain in all groups receiving beadlets, probably reflecting a nutritional influence. Blood sampling confirmed systemic exposure and some minor clinical chemistry differences in females at 200 and 1000 mg/kg bw/day. There was no effect on adjusted liver weight. Histopathological examination showed hepatic changes indicative of slight hepatotoxicity and hepatocyte regeneration in females at 200 and 1000 mg/kg bw/day, in addition to the adenoma. Taking into account this pathological background in the female rat, and a wide variety of other supporting information, it is concluded that the hepatocellular adenoma in female rats was secondary to hepatotoxicity and regeneration, and is most probably a species-specific phenomenon of doubtful human relevance. PMID:26713891

  1. Formaldehyde in dentistry: a review of mutagenic and carcinogenic potential

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, B.B.; Chestner, S.B.

    1981-09-01

    For many years there has been controversy over the value of antimicrobial drugs for intracanal dressings in endodontics. Formocresol, a formaldehyde compound, has evolved as the preferred drug for routine endodontic procedures, as well as pediatric endodontics. The increase in the use of formaldehyde has been complicated by the introduction of paraformaldehyde pastes for filling root canals. Neither of these formulas has ever been standardized. The doses are arbitrary, and the common dose of formocresol has been shown to be many times greater than the minimum dose needed for effect. The efficacy of paraformaldehyde pastes is questionable and remains clouded by inconclusive evidence, conflicting research, inadequate terminology, and a lack of convincing statistical evidence. The clinical use and delivery of formocresol and paraformaldehyde pastes remain arbitrary and unscientific. Formaldehyde has a known toxic mutagenic and carcinogenic potential. Many investigations have been conducted to measure the risk of exposure to formaldehyde; it is clear that formaldehyde poses a carcinogenic risk in humans. There is a need to reevaluate the rationale underlying the use of formaldehyde in dentistry particularly in light of its deleterious effects.

  2. Neoplastic transformation of human diploid fibroblast cells by chemical carcinogens

    Science.gov (United States)

    Kakunaga, Takeo

    1978-01-01

    Cultured fibroblast cells derived from a skin biopsy sample taken from normal human adult were exposed to a potent carcinogen, 4-nitroquinoline 1-oxide. Alterations of cell growth pattern such as higher density and piling up of cells were noticed in some fractions of cultures that were successively subcultured after nitroquinoline oxide treatment. Morphologically altered cells retained this growth pattern and became established lines of transformed cells without showing the limited life-span characteristic of normal cells in culture. The transformed cells showed a higher saturation density and the ability to grow in soft agar, properties that are usually correlated with neoplastic transformation of cells in culture. Selection of preexisting transformed human cells as a mechanism of this observed transformation seemed unlikely because clones of these normal cells could also be used to assess the transforming effect of nitroquinoline oxide. Preliminary results suggest that numerous cell divisions were required for the development of the transformation after nitroquinoline oxide treatment of these human cells. When the transformed cell lines were injected subcutaneously into nude (athymic) mice, solid tumors were produced at the site of inoculation. Treatment with N-methyl-N′-nitro-N-nitrosoguanidine also induced cell transformation, in a manner similar to treatment with nitroquinoline oxide. However, transformation was not induced with (i) 4-aminoquinoline 1-oxide (a noncarcinogenic derivative of 4-nitroquinoline 1-oxide), (ii) 3-methylcholanthrene (a carcinogen that cannot be metabolically activated by the target cells employed), or (iii) the solvent dimethyl sulfoxide. Images PMID:418410

  3. Book Sprint: A new model for rapid book authoring and content development

    International Nuclear Information System (INIS)

    We discuss our experiences and successes with the new 'Book Sprint' methodology for use in rapid authoring and content development for technical books and documentation, using a distributed team and appropriate on-line collaborative technologies. A sprint begins by assembling a group of domain experts for a short period of time-intensive content creation. The outline, scope, and approximate length of the book are established, and key contributors are identified. This is followed by remote and distributed work over a period of a few months, focussing on the bulk of the book. The Sprint Book methodology has already been used in the 'Wireless Networking in the Developing World' and 'Bandwidth Optimization and Management' books. Both of these are freely available under a Creative Commons License. (author)

  4. Study of the mechanism of carcinogenesis by carcinogens which are negative in the Ames test. Progress report, April 1-September 1, 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    Carcinogens ethionine, thioacetamide, and actinomycin D, all of which are negative in the Ames test and all of which raise the progesterone level in the chicken, were tested to determine their physiological role in carcinogenesis. The optimization of the carcinogenesis model also included evaluation of the chicken as the biological indicator of physiological changes relative to the above compounds. (PCS)

  5. Assessment of Carcinogenicity of di(2-ethylhexyl) phthalate in a short-term assay using Xpa(-/-) and Xpa(-/-)/p53(+/-) mice

    DEFF Research Database (Denmark)

    Mortensen, Alicja; Bertram, Margareta; Aarup, V.; Sørensen, Ilona Kryspin

    2002-01-01

    between the models. The only liver tumors in all models were adenomas in males with no statistically significantly increased incidence. For p-cresidine, the survival was decreased (p <0.05) only in transgenic models. Statistically significantly increased incidences of nonneoplastic lesions were recorded...... in the liver, urinary bladder, and nasal cavity in all models, and in kidneys in transgenic models. The only tumors with statistically significantly increased incidence were liver adenomas in transgenic models (XPA:1 vs 7; `XPA/p53': 0 vs 12; WT: 0 vs 5, p = 0.053) and urinary bladder carcinomas in...... XPA/p53 model (0 vs 7). The negative carcinogenic response to DEHP and the positive response to p-cresidine support the expected sensitivity to genotoxic carcinogens in these transgenic models....

  6. Modeling the Physical Properties of Popcorn Varieties as a Function of Kernel Moisture Content

    OpenAIRE

    Koyejo ODUOLA; Falilat Taiwo ADEMILUYI

    2011-01-01

    The physical properties such as the axial dimensions (length, width, thickness), geometric mean diameter, thousand kernel weight, shape characteristics (sphericity, kernel volume, kernel surface area), bulk density, particle or kernel density, as well as porosity have been evaluated as a function of kernel moisture content for pin and deep yellow varieties of Nigerian popcorn kernels. It has been observed that the length, width, thickness as well as the thousand kernel weight increase with in...

  7. Rain pattern analysis and forecast model based on GPS estimated atmospheric water vapor content

    OpenAIRE

    Priego De Los Santos, Enrique

    2012-01-01

    Rain is one of the fundamental processes of the hydrologic cycle as it can be the source of wealth or natural hazards. This experiment focuses in the relationship between rain occurrence and atmospheric pressure (Patm) and atmospheric water vapor content (PW), GPS estimated. The available nine years time series of each variable were analyzed. It allowed to state the existence of three rain patterns and monthly differences in the Patm-PW combinations. In spite of rain episodes take place only ...

  8. The Data Literacy Advisory Team at Virginia Tech: Developing a Content Model for Data Literacy Instruction

    OpenAIRE

    Ogier, Andrea L.; Lener, Edward; Miller, Rebecca K

    2013-01-01

    In Spring 2013, the Center for Digital Research and Scholarship and the University Libraries at Virginia Tech formed a Data Literacy Advisory Team (DLAT) composed of reference, instruction, collections, data services and subject librarians and library specialists. Tasked with developing an instructional framework for delivering research and data-related content to faculty, staff and students (both graduate and undergraduate) in the univeristy-at-large, DLAT began by developing a skill-focuse...

  9. Dynamics of a producer-grazer model incorporating the effects of excess food nutrient content on grazer's growth.

    Science.gov (United States)

    Peace, Angela; Wang, Hao; Kuang, Yang

    2014-09-01

    Modeling under the framework of ecological stoichiometric allows the investigation of the effects of food quality on food web population dynamics. Recent discoveries in ecological stoichiometry suggest that grazer dynamics are affected by insufficient food nutrient content (low phosphorus (P)/carbon (C) ratio) as well as excess food nutrient content (high P:C). This phenomenon is known as the "stoichiometric knife edge." While previous models have captured this phenomenon, they do not explicitly track P in the producer or in the media that supports the producer, which brings questions to the validity of their predictions. Here, we extend a Lotka-Volterra-type stoichiometric model by mechanistically deriving and tracking P in the producer and free P in the environment in order to investigate the growth response of Daphnia to algae of varying P:C ratios. Bifurcation analysis and numerical simulations of the full model, that explicitly tracks phosphorus, lead to quantitative different predictions than previous models that neglect to track free nutrients. The full model shows that the fate of the grazer population can be very sensitive to excess nutrient concentrations. Dynamical free nutrient pool seems to induce extreme grazer population density changes when total nutrient is in an intermediate range. PMID:25124765

  10. Determination of Catechin Content in Gambir Powder from Dried Gambir Leaves Quickly using FT NIR PLS Model

    Directory of Open Access Journals (Sweden)

    Andasuryani Andasuryani

    2014-01-01

    Full Text Available Conventional production process of gambir often produces gambir with low content of catechin. Engineering of production processes of gambir leaves to produce gambir powder has been developed by previous researchers. The objective of this study was to develop a calibration model to predict the content of catechin in gambir powder from dried gambir leaves quickly using FT-NIR PLS model.  Reflectance spectra of gambir powder from dried gambir leaves obtained at a wavelength of 1000 to 2500 nm. Spectra pre-processing treatment method used was a combination between normalization between 0 and 1 (n01 method and first derivative Savitzky-Golay 9 points (dg1. The result showed that correlation coefficient and standard error of prediction (SEP were 0.99 and 2.10 % respectively, obtained when used 6 factors of partial least square (PLS. Calibration model developed has shown higher accuracy and precision to predict catechin content of gambir powder from dried gambir leaves.

  11. Amplification of SV40 and cellular genes in SV40 transformed Chinese hamster embryo cells treated with chemical carcinogens

    International Nuclear Information System (INIS)

    To study the effect of chemical carcinogens on the amplification of specific genes, we have constructed a model system, utilizing integrated SV40 as an example for an endogenous gene. Recently, we have shown that exposure of SV40 transformed Chinese hamster cells to a variety of carcinogens induced the amplification of the integrated SV40 genome. Functional T-antigen was necessary for the amplification phenomenon. The work presented in this manuscript shows that the functional origin of replication, which consists of the sequences at the origin of replication and an active T-antigen, is required for the amplification. Utilizing cloned SV40 inserts and the adjacent Chinese hamster sequences we were able to show that SV40 and the flanking cellular sequences were amplified. As the distance from the SV40 origin of replication increased, the extent of amplification was decreased. The amplified sequences are associated with both chromosomal and extrachromosomal sequences. Carcinogen-mediated amplification is not restricted to SV40 sequences and endogenous genes such as dehydrofolate reductase (dhfr), the histocompatibility gene (HLA) and c-ras/sup Ha/ gene are amplified. 26 references, 5 figures

  12. Constraint of the limited information content of discharge measurements on the benefits of rating curve models with increased complexities

    Science.gov (United States)

    Van Eerdenbrugh, Katrien; Verhoest, Niko; De Mulder, Tom

    2015-04-01

    accounting for backwater effects. The GLUE evaluation based on available measurements however does not demonstrate this increased performance. The evaluation further reveals that complex rating curve models face parameterization problems when using field data. This inconsistency between evaluations based on the model and on in situ data should be attributed to the limited information content of the water level and discharge measurements. Despite of a measurement station with a highly stable cross section in time and more than 200 available measurements, these in situ data do not include every flow condition and the measurements contain errors. Consequently, the information content of the measured data turns out to be inadequate to distinguish the effects of increased complexity of rating curve models. This study reveals the importance of evaluating rating curve model formulations with regard to the informative content of their input and calibration data and demonstrates the usefulness of the GLUE methodology in this respect.

  13. Assessing HYDRUS-2D model to estimate soil water contents and olive tree transpiration fluxes under different water distribution systems

    Science.gov (United States)

    Autovino, Dario; Negm, Amro; Rallo, Giovanni; Provenzano, Giuseppe

    2016-04-01

    In Mediterranean countries characterized by limited water resources for agricultural and societal sectors, irrigation management plays a major role to improve water use efficiency at farm scale, mainly where irrigation systems are correctly designed to guarantee a suitable application efficiency and the uniform water distribution throughout the field. In the last two decades, physically-based agro-hydrological models have been developed to simulate mass and energy exchange processes in the soil-plant-atmosphere (SPA) system. Mechanistic models like HYDRUS 2D/3D (Šimunek et al., 2011) have been proposed to simulate all the components of water balance, including actual crop transpiration fluxes estimated according to a soil potential-dependent sink term. Even though the suitability of these models to simulate the temporal dynamics of soil and crop water status has been reported in the literature for different horticultural crops, a few researches have been considering arboreal crops where the higher gradients of root water uptake are the combination between the localized irrigation supply and the three dimensional root system distribution. The main objective of the paper was to assess the performance of HYDRUS-2D model to evaluate soil water contents and transpiration fluxes of an olive orchard irrigated with two different water distribution systems. Experiments were carried out in Castelvetrano (Sicily) during irrigation seasons 2011 and 2012, in a commercial farm specialized in the production of table olives (Olea europaea L., var. Nocellara del Belice), representing the typical variety of the surrounding area. During the first season, irrigation water was provided by a single lateral placed along the plant row with four emitters per plant (ordinary irrigation), whereas during the second season a grid of emitters laid on the soil was installed in order to irrigate the whole soil surface around the selected trees. The model performance was assessed based on the

  14. Model evaluation of the radiative and temperature effects of the ozone content changes in the global atmosphere of 1980's

    Science.gov (United States)

    Karol, Igor L.; Frolkis, Victor A.

    1994-01-01

    Radiative and temperature effects of the observed ozone and greenhouse gas atmospheric content changes in 1980 - 1990 are evaluated using the two-dimensional energy balance radiative-convective model of the zonally and annually averaged troposphere and stratosphere. Calculated radiative flux changes for standard conditions quantitatively agree with their estimates in WMO/UNEP 1991 review. Model estimates indicate rather small influence of ozone depletion in the lower stratosphere on the greenhouse tropospheric warming rate, being more significant in the non-tropical Southern Hemisphere. The calculated cooling of the lower stratosphere is close to the observed temperature trends there in the last decade.

  15. The assessment of evapotranspiration and soil water content in the Kysuca river basin (Slovakia) using rainfall-runoff model

    Czech Academy of Sciences Publication Activity Database

    Košková, Romana; Němečková, Soňa; Sitková, Z.

    Ljubljana : Slovenian National Committee for the IHP Unesco, 2008 - (Brilly, M.; Šraj, M.), 096 ISBN 978-961-91090-2-1. [Conference of the Danubian Countries /24./. Bled (SI), 02.06.2008-04.06.2008] R&D Projects: GA AV ČR(CZ) KJB300600602 Institutional research plan: CEZ:AV0Z20600510 Keywords : hydrologic model ling * soil water content * evapotranspiration * SWIM model Subject RIV: DA - Hydrology ; Limnology http://ksh.fgg.uni-lj.si/bled2008/cd_2008/01_Hydrological%20forecasting/096_Koskova.pdf

  16. Comparison of invasive and non-invasive electromagnetic methods in soil water content estimation of a dike model

    International Nuclear Information System (INIS)

    Water infiltration through a dike model under controlled flooding and drainage conditions was investigated using the gravimetric soil water sampling technique and electromagnetic techniques, in particular ground penetrating radar (GPR) applied in different forms, time domain reflectometry with intelligent microelements (TRIME-TDR) and spatial-time domain reflectometry (S-TDR). The experiments were conducted on the model in two phases. In the first phase, the model was flooded with varying water levels between 0 and 1.25 m above the waterproof base of the model. In the second phase, the characteristics of the temporal water content changes were investigated over a period of 65 days as the flood water drained off from the 1.25 m level. The dike model was constructed with soil of the texture class loamy sand. The aim of the experiment was to investigate whether GPR-based invasive and non-invasive methods were able to quantitatively observe and correctly monitor temporal changes in the volumetric water content (VWC) within embankment dams. The VWC values from the various techniques corresponded very well, especially with low VWC values. A comparison with the VWC of gravimetric soil water sampling showed a satisfactory reproducibility. Characteristic discrepancies were recorded with higher values of the VWC. Under saturated conditions only the invasive methods were able to produce reasonable values of the VWC. After the release of the highest flood level, the drainage phase could be characterized by two invasive methods based on the TDR and GPR techniques

  17. The fermion content of the Standard Model from a simple world-line theory

    Directory of Open Access Journals (Sweden)

    Paul Mansfield

    2015-04-01

    Full Text Available We describe a simple model that automatically generates the sum over gauge group representations and chiralities of a single generation of fermions in the Standard Model, augmented by a sterile neutrino. The model is a modification of the world-line approach to chiral fermions.

  18. Using the SIOP Model for Effective Content Teaching with Second and Foreign Language Learners

    Science.gov (United States)

    Kareva, Veronika; Echevarria, Jana

    2013-01-01

    In this paper we present a comprehensive model of instruction for providing consistent, high quality teaching to L2 students. This model, the SIOP Model (Sheltered Instruction Observation Protocol), provides an explicit framework for organizing instructional practices to optimize the effectiveness of teaching second and foreign language learners.…

  19. Digital Content Strategies

    OpenAIRE

    Daniel Halbheer; Florian Stahl; Oded Koenigsberg; Donald R. Lehmann

    2013-01-01

    This paper studies content strategies for online publishers of digital information goods. It examines sampling strategies and compares their performance to paid content and free content strategies. A sampling strategy, where some of the content is offered for free and consumers are charged for access to the rest, is known as a "metered model" in the newspaper industry. We analyze optimal decisions concerning the size of the sample and the price of the paid content when sampling serves the dua...

  20. ESIP's Emerging Provenance and Context Content Standard Use Cases: Developing Examples and Models for Data Stewardship

    Science.gov (United States)

    Ramdeen, S.; Hills, D. J.

    2013-12-01

    Earth science data collections range from individual researchers' private collections to large-scale data warehouses, from computer-generated data to field or lab based observations. These collections require stewardship. Fundamentally, stewardship ensures long term preservation and the provision of access to the user community. In particular, stewardship includes capturing appropriate metadata and documentation--and thus the context of the data's creation and any changes they underwent over time --to enable data reuse. But scientists and science data managers must translate these ideas into practice. How does one balance the needs of current and (projected) future stakeholders? In 2011, the Data Stewardship Committee (DSC) of the Federation of Earth Science Information Partners (ESIP) began developing the Provenance and Context Content Standard (PCCS). As an emerging standard, PCCS provides a framework for 'what' must be captured or preserved as opposed to describing only 'how' it should be done. Originally based on the experiences of NASA and NOAA researchers within ESIP, the standard currently provides data managers with content items aligned to eight key categories. While the categories and content items are based on data life cycles of remote sensing missions, they can be generalized to cover a broader set of activities, for example, preservation of physical objects. These categories will include the information needed to ensure the long-term understandability and usability of earth science data products. In addition to the PCCS, the DSC is developing a series of use cases based on the perspectives of the data archiver, data user, and the data consumer that will connect theory and practice. These cases will act as specifications for developing PCCS-based systems. They will also provide for examination of the categories and content items covered in the PCCS to determine if any additions are needed to cover the various use cases, and also provide rationale and

  1. Modeling sugar content of farmer-managed sugar beets (Beta vulgaris L.).

    OpenAIRE

    Abdullah A. Jaradat; Jana Rinke

    2012-01-01

    We measured or estimated leaf and root physical and chemical traits of spatio-temporally heterogeneousfield-grown sugar beet throughout its ontogeny during three growing seasons. The objective was toquantify the impact of temporal changes in these traits on root sugar content [S(R); g 100 g-1 root dryweight]. Artificial Neural Network (ANN), in conjunction with thermal time (ºCd), adequately delineatedthe boundaries (mean ± standard deviation, S.D.) between S(R) during early (41.6 ± 6.2), med...

  2. Development of a coal shrinkage-swelling model accounting for water content in the micropores

    Energy Technology Data Exchange (ETDEWEB)

    Prob Thararoop; Zuleima T. Karpyn; Turgay Ertekin [Pennsylvania State University, University Park, PA (United States). Petroleum and Natural Gas Engineering

    2009-07-01

    Changes in cleat permeability of coal seams are influenced by internal stress, and release or adsorption of gas in the coal matrix during production/injection processes. Coal shrinkage-swelling models have been proposed to quantify such changes; however none of the existing models incorporates the effect of the presence of water in the micropores on the gas sorption of coalbeds. This paper proposes a model of coal shrinkage and swelling, incorporating the effect of water in the micropores. The proposed model was validated using field permeability data from San Juan basin coalbeds and compared with coal shrinkage and swelling models existing in the literature.

  3. Molecular basis of carcinogenicity of tungsten alloy particles

    International Nuclear Information System (INIS)

    The tungsten alloy of 91% tungsten, 6% nickel and 3% cobalt (WNC 91–6–3) induces rhabdomyosarcoma when implanted into a rat thigh muscle. To investigate whether this effect is species-specific human HSkMc primary muscle cells were exposed to WNC 91–6–3 particles and responses were compared with those from a rat skeletal muscle cell line (L6-C11). Toxicity was assessed by the adenylate kinase assay and microscopy, DNA damage by the Comet assay. Caspase 3 enzyme activity was measured and oligonucleotide microarrays were used for transcriptional profiling. WNC 91–6–3 particles caused toxicity in cells adjacent to the particles and also increased DNA strand breaks. Inhibition of caspase 3 by WNC 91–6–3 occurred in rat but not in human cells. In both rat and human cells, the transcriptional response to WNC 91–6–3 showed repression of transcripts encoding muscle-specific proteins with induction of glycolysis, hypoxia, stress responses and transcripts associated with DNA damage and cell death. In human cells, genes encoding metallothioneins were also induced, together with genes related to angiogenesis, dysregulation of apoptosis and proliferation consistent with pre-neoplastic changes. An alloy containing iron, WNF 97–2–1, which is non-carcinogenic in vivo in rats, did not show these transcriptional changes in vitro in either species while the corresponding cobalt-containing alloy, WNC 97–2–1 elicited similar responses to WNC 91–6–3. Tungsten alloys containing both nickel and cobalt therefore have the potential to be carcinogenic in man and in vitro assays coupled with transcriptomics can be used to identify alloys, which may lead to tumour formation, by dysregulation of biochemical processes. - Highlights: • Use of transcriptomics to identify likely carcinogenic tungsten alloys in vitro • Cobalt containing alloys cause oxidative stress, DNA-damage and perturb apoptosis. • Presence of cobalt causes changes in gene expression

  4. Molecular biomarkers of oxidative stress associated with bromate carcinogenicity

    International Nuclear Information System (INIS)

    Potassium bromate (KBrO3) is a chemical oxidizing agent found in drinking water as a disinfection byproduct of surface water ozonation. Chronic exposures to KBrO3 cause renal cell tumors in rats, hamsters and mice and thyroid and testicular mesothelial tumors in rats. Experimental evidence indicates that bromate mediates toxicological effects via the induction of oxidative stress. To investigate the contribution of oxidative stress in KBrO3-induced cancer, male F344 rats were administered KBrO3 in their drinking water at multiple concentrations for 2-100 weeks. Gene expression analyses were performed on kidney, thyroid and mesothelial cell RNA. Families of mRNA transcripts differentially expressed with respect to bromate treatment included multiple cancer, cell death, ion transport and oxidative stress genes. Multiple glutathione metabolism genes were up-regulated in kidney following carcinogenic (400 mg/L) but not non-carcinogenic (20 mg/L) bromate exposures. 8-Oxodeoxyguanosine glycosylase (Ogg1) mRNA was up-regulated in response to bromate treatment in kidney but not thyroid. A dramatic decrease in global gene expression changes was observed following 1 mg/L compared to 20 mg/L bromate exposures. In a separate study oxygen-18 (18O) labeled KBrO3 was administered to male rats by oral gavage and tissues were analyzed for 18O deposition. Tissue enrichment of 18O was observed at 5 and 24 h post-KBr18O3 exposure with the highest enrichment occurring in the liver followed by the kidney, thyroid and testes. The kidney dose response observed was biphasic showing similar statistical increases in 18O deposition between 0.25 and 50 mg/L (equivalent dose) KBr18O3 followed by a much greater increase above 50 mg/L. These results suggest that carcinogenic doses of potassium bromate require attainment of a threshold at which oxidation of tissues occurs and that gene expression profiles may be predictive of these physiological changes in renal homeostasis

  5. Molecular basis of carcinogenicity of tungsten alloy particles

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Robert M.; Williams, Tim D.; Waring, Rosemary H.; Hodges, Nikolas J., E-mail: n.hodges@bham.ac.uk

    2015-03-15

    The tungsten alloy of 91% tungsten, 6% nickel and 3% cobalt (WNC 91–6–3) induces rhabdomyosarcoma when implanted into a rat thigh muscle. To investigate whether this effect is species-specific human HSkMc primary muscle cells were exposed to WNC 91–6–3 particles and responses were compared with those from a rat skeletal muscle cell line (L6-C11). Toxicity was assessed by the adenylate kinase assay and microscopy, DNA damage by the Comet assay. Caspase 3 enzyme activity was measured and oligonucleotide microarrays were used for transcriptional profiling. WNC 91–6–3 particles caused toxicity in cells adjacent to the particles and also increased DNA strand breaks. Inhibition of caspase 3 by WNC 91–6–3 occurred in rat but not in human cells. In both rat and human cells, the transcriptional response to WNC 91–6–3 showed repression of transcripts encoding muscle-specific proteins with induction of glycolysis, hypoxia, stress responses and transcripts associated with DNA damage and cell death. In human cells, genes encoding metallothioneins were also induced, together with genes related to angiogenesis, dysregulation of apoptosis and proliferation consistent with pre-neoplastic changes. An alloy containing iron, WNF 97–2–1, which is non-carcinogenic in vivo in rats, did not show these transcriptional changes in vitro in either species while the corresponding cobalt-containing alloy, WNC 97–2–1 elicited similar responses to WNC 91–6–3. Tungsten alloys containing both nickel and cobalt therefore have the potential to be carcinogenic in man and in vitro assays coupled with transcriptomics can be used to identify alloys, which may lead to tumour formation, by dysregulation of biochemical processes. - Highlights: • Use of transcriptomics to identify likely carcinogenic tungsten alloys in vitro • Cobalt containing alloys cause oxidative stress, DNA-damage and perturb apoptosis. • Presence of cobalt causes changes in gene expression

  6. Salt Composition Derived from Veazey Composition by Thermodynamic Modeling and Predicted Composition of Drum Contents

    International Nuclear Information System (INIS)

    This report describes the derivation of the salt composition from the Veazey salt stream analysis. It also provides an estimate of the proportions of the kitty litter, nitrate salt and neutralizer that was contained in drum 68660. While the actinide content of waste streams was judiciously followed in the 1980s in TA-55, no record of the salt composition could be found. Consequently, a salt waste stream produced from 1992 to 1994 and reported by Gerry Veazey provided the basis for this study. While chemical analysis of the waste stream was highly variable, an average analysis provided input to the Stream Analyzer software to calculate a composition for a concentrated solid nitrate salt and liquid waste stream. The calculation predicted the gas / condensed phase compositions as well as solid salt / saturated liquid compositions. The derived composition provides an estimate of the nitrate feedstream to WIPP for which kinetic measurements can be made. The ratio of salt to Swheat in drum 68660 contents was estimated through an overall mass balance on the parent and sibling drums. The RTR video provided independent confirmation concerning the volume of the mixture. The solid salt layer contains the majority of the salt at a ratio with Swheat that potentially could become exothermic.

  7. Salt Composition Derived from Veazey Composition by Thermodynamic Modeling and Predicted Composition of Drum Contents

    Energy Technology Data Exchange (ETDEWEB)

    Weisbrod, Kirk Ryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Veirs, Douglas Kirk [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Funk, David John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clark, David Lewis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-11

    This report describes the derivation of the salt composition from the Veazey salt stream analysis. It also provides an estimate of the proportions of the kitty litter, nitrate salt and neutralizer that was contained in drum 68660. While the actinide content of waste streams was judiciously followed in the 1980s in TA-55, no record of the salt composition could be found. Consequently, a salt waste stream produced from 1992 to 1994 and reported by Gerry Veazey provided the basis for this study. While chemical analysis of the waste stream was highly variable, an average analysis provided input to the Stream Analyzer software to calculate a composition for a concentrated solid nitrate salt and liquid waste stream. The calculation predicted the gas / condensed phase compositions as well as solid salt / saturated liquid compositions. The derived composition provides an estimate of the nitrate feedstream to WIPP for which kinetic measurements can be made. The ratio of salt to Swheat in drum 68660 contents was estimated through an overall mass balance on the parent and sibling drums. The RTR video provided independent confirmation concerning the volume of the mixture. The solid salt layer contains the majority of the salt at a ratio with Swheat that potentially could become exothermic.

  8. Evolutionary constraints over microsatellite abundance in larger mammals as a potential mechanism against carcinogenic burden.

    Science.gov (United States)

    Park, Jung Youn; An, Yong-Rock; An, Chul-Min; Kang, Jung-Ha; Kim, Eun Mi; Kim, Heebal; Cho, Seoae; Kim, Jaemin

    2016-01-01

    Larger organisms tend to live longer, have more potentially carcinogenic cells, and undergo more cell divisions. While one might intuitively expect cancer incidence to scale with body size, this assertion does not hold over the range of different mammals. Explaining this lack of correlation, so-called 'Peto's paradox' can likely increase our understanding of how cancer defense mechanisms are shaped by natural selection. Here, we study the occurrence of microsatellite in mammal genomes and observe that animals with expanded body size restrain the number of microsatellite. To take into account of higher mutation rate in the microsatellite region compared to that of genome, limiting the abundance of somatic mutations might explain how larger organisms could overcome the burden of cancer. These observations may serve as the basis to better understand how evolution has modeled protective mechanisms against cancer development. PMID:27125812

  9. Emissions and air exposure of carcinogens and co-carcinogens in four Nordic countries

    DEFF Research Database (Denmark)

    Fauser, Patrik; Plejdrup, Marlene Schmidt; Ketzel, Matthias;

    This project (KoL 12-08) was performed for the Climate and Air Quality Group (KlimaogLuftgruppen, KoL), Nordic Council of Ministers by atmospheric emission, exposureand epidemiology experts from Denmark, Finland, Norway and Sweden. Emission inventory methods and exposure models were presented. A...... sources, traffic and residential wood combustion. An overview of local studies on exposure for cities or communities with emphasis on wood combustion and traffic and a discussion of existing epidemiological studies on cancer and environment were given...

  10. Assessing the Information Content in Environmental Modelling: A Carbon Cycle Perspective

    OpenAIRE

    Ian G. Enting

    2008-01-01

    A model represents the way in which information about the world is captured in a form that can be manipulated for application to new situations. However, quantification of `model error' presents formidable challenges. Various inverse problems in carbon cycle modelling are presented as illustrations of the issues. A `maximum-entropy' representation of carbon cycle response is used to explore techniques for non-parametric estimation of carbon cycle uncertainty.

  11. Modelling soil water content variations under drought stress on soil column cropped with winter wheat

    OpenAIRE

    Csorba, Szilveszter; Raveloson, Andrea; Tóth, Estzer; Nagy, Viliam; Farkas, Csilla

    2014-01-01

    Mathematical models are effective tools for evaluating the impact of predicted climate change on agricultural production, but it is difficult to test their applicability to future weather conditions. We applied the SWAP model to assess its applicability to climate conditions, differing from those, for which the model was developed. We used a database obtained from a winter wheat drought stress experiment. Winter wheat was grown in six soil columns, three having optimal water supply (NS), whil...

  12. Development of NIRS models to predict protein and amylose content of brown rice and proximate compositions of rice bran.

    Science.gov (United States)

    Bagchi, Torit Baran; Sharma, Srigopal; Chattopadhyay, Krishnendu

    2016-01-15

    With the escalating persuasion of economic and nutritional importance of rice grain protein and nutritional components of rice bran (RB), NIRS can be an effective tool for high throughput screening in rice breeding programme. Optimization of NIRS is prerequisite for accurate prediction of grain quality parameters. In the present study, 173 brown rice (BR) and 86 RB samples with a wide range of values were used to compare the calibration models generated by different chemometrics for grain protein (GPC) and amylose content (AC) of BR and proximate compositions (protein, crude oil, moisture, ash and fiber content) of RB. Various modified partial least square (mPLSs) models corresponding with the best mathematical treatments were identified for all components. Another set of 29 genotypes derived from the breeding programme were employed for the external validation of these calibration models. High accuracy of all these calibration and prediction models was ensured through pair t-test and correlation regression analysis between reference and predicted values. PMID:26258697

  13. ICT Integration in Nigeria and the Quest for Indigenous Contents: Prospects of the i-CLAP Model Design Initiative

    Science.gov (United States)

    Azi, J. I.; Nkom, A. A.; Schweppe, M.

    2012-10-01

    Advances in Information and Communication Technology (ICT) is transforming the 21st century learning environment, from its traditional face-to-face, structured curriculum, fixed location and teacher-centered nature, into a more flexible and self-directed process. For instance, variously designed and developed instructional multimedia contents and interfaces in forms of (i) productivity, (ii) educational or (iii) gaming software, enable active learning access as mobile or classroom technologies, interactive tutorials, online discussions, internet conferencing and online databases. However, while this article considers these recent developments such as Intellimedia, NEPAD e-School, OLPC and Intel Classmate projects and so on as trendy and groundbreaking. It observes with discontent that the design of their contents and interfaces seem to be targeted at cross-cultural audiences, with very little or no consideration for minorities like Africa. The authors opine therefore that if the challenge of ICT integration towards bridging the digital divides in Africa must be taken very serious, the task transcends merely supplying networked computer hardware to local schools. Digital contents are required that reflect the beauty and riches of Africaís culture and heritage like music, fashion, architecture, arts and crafts. Against which backdrop, the Interactive Child Learning Aid Project (i-CLAP) model was initiated as a potential indigenous resource, for enhancing pre-primary education in Nigeria adapting the ADDIE model structure. The researchers observe that while 'customizationí of ICT applications targeted at local audience is commendable, integrating relevant indigenous contents has the potential to enhance efficacy and consequently raise the motivational level of local learners.

  14. IARC Monographs: 40 Years of Evaluating Carcinogenic Hazards to Humans

    Science.gov (United States)

    Blair, Aaron; Vineis, Paolo; Ahrens, Wolfgang; Andersen, Aage; Anto, Josep M.; Armstrong, Bruce K.; Baccarelli, Andrea A.; Beland, Frederick A.; Berrington, Amy; Bertazzi, Pier Alberto; Birnbaum, Linda S.; Brownson, Ross C.; Bucher, John R.; Cantor, Kenneth P.; Cardis, Elisabeth; Cherrie, John W.; Christiani, David C.; Cocco, Pierluigi; Coggon, David; Comba, Pietro; Demers, Paul A.; Dement, John M.; Douwes, Jeroen; Eisen, Ellen A.; Engel, Lawrence S.; Fenske, Richard A.; Fleming, Lora E.; Fletcher, Tony; Fontham, Elizabeth; Forastiere, Francesco; Frentzel-Beyme, Rainer; Fritschi, Lin; Gerin, Michel; Goldberg, Marcel; Grandjean, Philippe; Grimsrud, Tom K.; Gustavsson, Per; Haines, Andy; Hartge, Patricia; Hansen, Johnni; Hauptmann, Michael; Heederik, Dick; Hemminki, Kari; Hemon, Denis; Hertz-Picciotto, Irva; Hoppin, Jane A.; Huff, James; Jarvholm, Bengt; Kang, Daehee; Karagas, Margaret R.; Kjaerheim, Kristina; Kjuus, Helge; Kogevinas, Manolis; Kriebel, David; Kristensen, Petter; Kromhout, Hans; Laden, Francine; Lebailly, Pierre; LeMasters, Grace; Lubin, Jay H.; Lynch, Charles F.; Lynge, Elsebeth; ‘t Mannetje, Andrea; McMichael, Anthony J.; McLaughlin, John R.; Marrett, Loraine; Martuzzi, Marco; Merchant, James A.; Merler, Enzo; Merletti, Franco; Miller, Anthony; Mirer, Franklin E.; Monson, Richard; Nordby, Karl-Cristian; Olshan, Andrew F.; Parent, Marie-Elise; Perera, Frederica P.; Perry, Melissa J.; Pesatori, Angela Cecilia; Pirastu, Roberta; Porta, Miquel; Pukkala, Eero; Rice, Carol; Richardson, David B.; Ritter, Leonard; Ritz, Beate; Ronckers, Cecile M.; Rushton, Lesley; Rusiecki, Jennifer A.; Rusyn, Ivan; Samet, Jonathan M.; Sandler, Dale P.; de Sanjose, Silvia; Schernhammer, Eva; Costantini, Adele Seniori; Seixas, Noah; Shy, Carl; Siemiatycki, Jack; Silverman, Debra T.; Simonato, Lorenzo; Smith, Allan H.; Smith, Martyn T.; Spinelli, John J.; Spitz, Margaret R.; Stallones, Lorann; Stayner, Leslie T.; Steenland, Kyle; Stenzel, Mark; Stewart, Bernard W.; Stewart, Patricia A.; Symanski, Elaine; Terracini, Benedetto; Tolbert, Paige E.; Vainio, Harri; Vena, John; Vermeulen, Roel; Victora, Cesar G.; Ward, Elizabeth M.; Weinberg, Clarice R.; Weisenburger, Dennis; Wesseling, Catharina; Weiderpass, Elisabete; Zahm, Shelia Hoar

    2015-01-01

    Background: Recently, the International Agency for Research on Cancer (IARC) Programme for the Evaluation of Carcinogenic Risks to Humans has been criticized for several of its evaluations, and also for the approach used to perform these evaluations. Some critics have claimed that failures of IARC Working Groups to recognize study weaknesses and biases of Working Group members have led to inappropriate classification of a number of agents as carcinogenic to humans. Objectives: The authors of this Commentary are scientists from various disciplines relevant to the identification and hazard evaluation of human carcinogens. We examined criticisms of the IARC classification process to determine the validity of these concerns. Here, we present the results of that examination, review the history of IARC evaluations, and describe how the IARC evaluations are performed. Discussion: We concluded that these recent criticisms are unconvincing. The procedures employed by IARC to assemble Working Groups of scientists from the various disciplines and the techniques followed to review the literature and perform hazard assessment of various agents provide a balanced evaluation and an appropriate indication of the weight of the evidence. Some disagreement by individual scientists to some evaluations is not evidence of process failure. The review process has been modified over time and will undoubtedly be altered in the future to improve the process. Any process can in theory be improved, and we would support continued review and improvement of the IARC processes. This does not mean, however, that the current procedures are flawed. Conclusions: The IARC Monographs have made, and continue to make, major contributions to the scientific underpinning for societal actions to improve the public’s health. Citation: Pearce N, Blair A, Vineis P, Ahrens W, Andersen A, Anto JM, Armstrong BK, Baccarelli AA, Beland FA, Berrington A, Bertazzi PA, Birnbaum LS, Brownson RC, Bucher JR, Cantor KP

  15. Screening tests for determination of cytotoxic agent, mutagens and carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Spiegelberg, T.; Koerdel, W.; Goertz, T.; Thriemer, A.

    1983-01-01

    It is supposed that chemical substances are the primary factors responsible for the development of tumors and genetic damages. From this results the urgend demand to examine at least the frequently applied and suspicious substances on possibly health-affecting effects. The performance of these examinations with experimental animals requires a lot of time and financial support and has increasingly been criticised in public with regard to protection of animals. Experience gained in the U.S.A. revealed that the carcinogenicity test of one single substance performed with animal experiments takes approximately 3 years and costs about 300,000 Dollars. Therefore the application of cell cultures for such examinations and tests has been postulated and discussed for several years. Cell cultures require only little space and generally the observed effects develop after only a short time. Objectification and statistical assessment (due to high cell amounts per test) can be performed without any problems.

  16. The Weight of Evidence Does Not Support the Listing of Styrene as "Reasonably Anticipated to be a Human Carcinogen" in NTP's Twelfth Report on Carcinogens.

    Science.gov (United States)

    Rhomberg, Lorenz R; Goodman, Julie E; Prueitt, Robyn L

    2013-01-01

    Styrene was listed as "reasonably anticipated to be a human carcinogen" in the twelfth edition of the National Toxicology Program's Report on Carcinogens based on what we contend are erroneous findings of limited evidence of carcinogenicity in humans, sufficient evidence of carcinogenicity in experimental animals, and supporting mechanistic data. The epidemiology studies show no consistent increased incidence of, or mortality from, any type of cancer. In animal studies, increased incidence rates of mostly benign tumors have been observed only in certain strains of one species (mice) and at one tissue site (lung). The lack of concordance of tumor incidence and tumor type among animals (even within the same species) and humans indicates that there has been no particular cancer consistently observed among all available studies. The only plausible mechanism for styrene-induced carcinogenesis-a non-genotoxic mode of action that is specific to the mouse lung-is not relevant to humans. As a whole, the evidence does not support the characterization of styrene as "reasonably anticipated to be a human carcinogen," and styrene should not be listed in the Report on Carcinogens. PMID:23335843

  17. Evaluation of ice and snow content in the global numerical weather prediction model GME with CloudSat

    Directory of Open Access Journals (Sweden)

    S. Reitter

    2011-07-01

    Full Text Available The present study evaluates the global numerical weather prediction model GME with respect to the grid-scale parameterization of frozen particles, both ice and snow, focusing on the performance of a diagnostic versus a prognostic precipitation scheme. As a reference, CloudSat Cloud Profiling Radar observations are utilized – the so far only near-globally available data set which vertically resolves clouds. Both the observation-to-model and the model-to-observation approach are applied and compared to each other. For the latter, the radar simulator QuickBeam is utilized. Criteria are applied to further improve the comparability between model and observations. The two model versions are statistically evaluated for a four-month period.

    The comparison reveals that the prognostic scheme reproduces the shape of the CloudSat frequency distributions for both ice water content (IWC and reflectivity factor well, while the diagnostic scheme produces no large IWCs or reflectivity factors because snow falls out instantaneously. However, the prognostic scheme overestimates the occurrence of high ice water paths (IWP, especially in the mid-latitudes. Sensitivity tests show that an increased fall speed of snow successfully reduces IWP. Both evaluation approaches capture the general features, but for details, the two together deliver the largest informational content. In case of limited resources, the model-to-observation approach is recommended. Finally, the results indicate that the lack of IWC in most global circulation models might be attributed to the use of diagnostic precipitation schemes, i.e., the lack of snow aloft.

    Based on its good performance the prognostic scheme went into operational mode in February 2010. The adjusted snow fall speed went operational in December 2010. However, continual improvements of the ice microphysics are necessary, which can be assessed by the proposed evaluation technique.

  18. Evaluation of ice and snow content in the global numerical weather prediction model GME with CloudSat

    Directory of Open Access Journals (Sweden)

    S. Eikenberg

    2011-02-01

    Full Text Available The present study evaluates the global numerical weather prediction model GME with respect to frozen particles, both ice and snow, focusing on the performance of a diagnostic versus a prognostic precipitation scheme. As a reference, CloudSat Cloud Profiling Radar observations are utilized – the so far only near-globally available data set which vertically resolves clouds. Both the observation-to-model and the model-to-observation approach are applied and compared to each other. For the latter, the radar simulator QuickBeam is utilized. Criteria are applied to further improve the comparability between model and observations. The two model versions are statistically evaluated for a four-month period.

    The comparison reveals that the prognostic scheme reproduces the shape of the CloudSat frequency distributions for both ice water content (IWC and reflectivity factor well, while the diagnostic scheme produces no large IWCs or reflectivity factors because snow falls out instantaneously. However, the prognostic scheme overestimates the occurrence of high ice water paths (IWP, especially in the mid-latitudes. Sensitivity tests show that an increased fall speed of snow successfully reduces IWP. Both approaches capture the general features, but for details, the two together deliver the largest informational content. In case of limited resources, the model-to-observation approach is preferred. Finally, the results indicate that the lack of IWC in most global circulation models might be attributed to the use of diagnostic precipitation schemes, i.e., the lack of snow aloft.

    Based on its good performance the prognostic scheme went into operational mode in February 2010. The adjusted snow fall speed went operational in December 2010. However, continual improvements of the ice microphysics are necessary, which can be assessed by the proposed evaluation technique.

  19. Disposition of smoked cannabis with high [Delta]9-tetrahydrocannabinol content: A kinetic model.

    NARCIS (Netherlands)

    Hunault, C.C.; van Eijkeren, J.C.; Mensinga, T.T.; de Vries, I.; Leenders, M.E.C.; Meulenbelt, J.

    2010-01-01

    Introduction No model exists to describe the disposition and kinetics of inhaled cannabis containing a high THC dose. We aimed to develop a kinetic model providing estimates of the THC serum concentrations after smoking cannabis cigarettes containing high THC doses (up to 69 mg THC).Methods Twenty-f

  20. Nucleon form factors and spin content in a quark-diquark model with a pion cloud

    OpenAIRE

    Cloet, Ian C.; Miller, Gerald A.

    2012-01-01

    We propose a new model of the nucleon in which quark-diquark configurations immersed in a pion cloud are treated in a manner consistent with Poincar\\'e invariance. With suitably chosen parameters, the computations employing this model reproduce the measured electromagnetic form factors and the quark-spin contribution to the total nucleon angular momentum.

  1. Nitrogen and amino acids content in lake Drukshyaj plancton organisms biocenoses grown in model experiments

    International Nuclear Information System (INIS)

    Biocenoses growth in lake Drukshyaj (from 1984 water reservoir of the Ignalina NPP) collected in July 1985 and grown in 2 various in composition culture media: in medium close in composition of main minerals to water of high capacity reservoir (medium 1) and in medium Fitzjarld (medium 2), has shown that the medium affects the component composition of plancton, as well as dominating types of algae. Phytoplancton was dominating component in biomass in both media. In medium 1 dominate green and diatoms, in medium 2 - blue-green algae. Content of proteins and amino acids in biomass changed depending on duration of biocenoses growth when dominating green and diatoms in biocenoses mass grown in medium 1, it reached maximum on the 15th day, and when dominating blue-green algae in biocenoses biomass grown in medium 2 - on the 30th day

  2. The carcinogenicity of dietary acrylamide intake: A comparative discussion of epidemiological and experimental animal research

    NARCIS (Netherlands)

    Hogervorst, J.G.F.; Baars, B.-J.; Schouten, L.J.; Konings, E.J.M.; Goldbohm, R.A.; Brandt, P.A. van den

    2010-01-01

    Since 2002, it is known that the probable human carcinogen acrylamide is present in commonly consumed carbohydrate-rich foods, such as French fries and potato chips. In this review, the authors discuss the body of evidence on acrylamide carcinogenicity from both epidemiological and rodent studies, i

  3. Study of isotopic tracing related with mechanism of cancer caused by carcinogenic substance

    International Nuclear Information System (INIS)

    In order to understand the mechanism of cancer caused by carcinogenic substance, a project using 41Ca as tracer and accelerator mass spectrometry (AMS) as measurement method to investigate the origin of the increased Ca2+ when the cells are exposed to carcinogenic substances is being undertaken. Several results as bellow have been obtained

  4. Carcinogenic potential of some pesticides in a medium-term multi-organ bioassay in rats.

    Science.gov (United States)

    Hasegawa, R; Cabral, R; Hoshiya, T; Hakoi, K; Ogiso, T; Boonyaphiphat, P; Shirai, T; Ito, N

    1993-05-28

    The carcinogenic potential of 5 pesticides was analyzed using a medium-term multi-organ bioassay for carcinogenicity. Male F344 rats were initially treated with 3 known carcinogens (diethylnitrosamine, N-methyl-N-nitrosourea and N-bis(2-hydroxypropyl)nitrosamine) during a period of 4 weeks to induce neoplastic changes in a variety of organs, and then given one of 5 pesticides in the diet for a further 16 weeks. Neoplastic and pre-neoplastic lesions were found in the thyroid, kidney and urinary bladder with propineb, in the forestomach, kidney and thyroid with captan and folpet. The number of glutathione S-transferase placental-form-positive liver-cell foci was significantly increased in the captan- and phosmet-treated groups. Based on these findings, captan and propineb can be considered as carcinogens and carcinogenicity is suspected for folpet and phosmet. These results are in concordance with reported long-term carcinogenicity for captan, folpet and propineb. Daminozide was considered not to be carcinogenic. Thus, the present assay of 20 weeks' duration is useful for the prediction of potential carcinogens. PMID:8509224

  5. The content of mercury in various types of cereals that were grown in the model conditions

    Directory of Open Access Journals (Sweden)

    Ľuboš Harangozo

    2016-01-01

    Full Text Available The consumption of cereals in Slovakia but also worldwide is increasing by every year. From 30000 to 50000 tons of mercury circulates throught the biosphere that gets into the atmosphere degassing of the earth's crust and world oceans. Mercury affects CNS and causes its disorders. The high doses of mercury causes a lot of different changes of personality as well as increased agitation, memory lossorinsomnia. It can also affect other organ systems such as the kidney. The exposure level is reflected in the concentration of mercury in blood and urine. The aim of our work was the evaluation of transfer of mercury from sludge to edible part of chosen cereals. The objectives were achieved in simulated conditions of growing pot experiment. We used agricultural soil from the location of Výčapy - Opatovce for the realization of the experiment. The sludge, which was added atvarious doses, was taken from Central Spiš area from locality of Rudňany near the village where minedironore that contains mainly copperand mercury during last few decades was. We used three types of cereals: barley (Hordeum sativum L. variety PRESTIGE, spring wheat (Triticum aestivum L. variety ISJARISSA and oat (Avena sativa L. variety TATRAN. The length of growing season was 90 days. From the obtained results of two years can be concluded that the accumulation of mercury by seed follows wheat ˂ barley ˂ oat. Even though that the oat is characterized by the highest accumulation of mercuryin the seeds, the content did not exceed the maximum level sspecified by The Codex Alimentarius of Slovak Republic. The results shows that the suitable cultivation of the cereals in localities, which are contaminated with heavy metals, especially by mercury, that the high content of mercury in soil do not pose a risk of accumulation of the metal into the cereal grain.

  6. The empirical content of models with multiple equilibria in economies with social interactions

    OpenAIRE

    Bisin, Alberto; Moro, Andrea; Topa, Giorgio

    2011-01-01

    We study a general class of models with social interactions that might display multiple equilibria. We propose an estimation procedure for these models and evaluate its efficiency and computational feasibility relative to different approaches taken to the curse of dimensionality implied by the multiplicity. Using data on smoking among teenagers, we implement the proposed estimation procedure to understand how group interactions affect health-related choices. We find that interaction effects a...

  7. Modelling soil water content variations under drought stress on soil column cropped with winter wheat

    Directory of Open Access Journals (Sweden)

    Csorba Szilveszter

    2014-12-01

    Full Text Available Mathematical models are effective tools for evaluating the impact of predicted climate change on agricultural production, but it is difficult to test their applicability to future weather conditions. We applied the SWAP model to assess its applicability to climate conditions, differing from those, for which the model was developed. We used a database obtained from a winter wheat drought stress experiment. Winter wheat was grown in six soil columns, three having optimal water supply (NS, while three were kept under drought-stressed conditions (S. The SWAP model was successfully calibrated against measured values of potential evapotranspiration (PET, potential evaporation (PE and total amount of water (TSW in the soil columns. The Nash-Sutcliffe model efficiency coefficient (N-S for TWS for the stressed columns was 0.92. For the NS treatment, we applied temporally variable soil hydraulic properties because of soil consolidation caused by regular irrigation. This approach improved the N-S values for the wetting-drying cycle from -1.77 to 0.54. We concluded that the model could be used for assessing the effects of climate change on soil water regime. Our results indicate that soil water balance studies should put more focus on the time variability of structuredependent soil properties.

  8. Content-adaptive pentary steganography using the multivariate generalized Gaussian cover model

    Science.gov (United States)

    Sedighi, Vahid; Fridrich, Jessica; Cogranne, Rémi

    2015-03-01

    The vast majority of steganographic schemes for digital images stored in the raster format limit the amplitude of embedding changes to the smallest possible value. In this paper, we investigate the possibility to further improve the empirical security by allowing the embedding changes in highly textured areas to have a larger amplitude and thus embedding there a larger payload. Our approach is entirely model driven in the sense that the probabilities with which the cover pixels should be changed by a certain amount are derived from the cover model to minimize the power of an optimal statistical test. The embedding consists of two steps. First, the sender estimates the cover model parameters, the pixel variances, when modeling the pixels as a sequence of independent but not identically distributed generalized Gaussian random variables. Then, the embedding change probabilities for changing each pixel by 1 or 2, which can be transformed to costs for practical embedding using syndrome-trellis codes, are computed by solving a pair of non-linear algebraic equations. Using rich models and selection-channel-aware features, we compare the security of our scheme based on the generalized Gaussian model with pentary versions of two popular embedding algorithms: HILL and S-UNIWARD.

  9. Carotenoid content of commonly consumed herbs and assessment of their bioaccessibility using an in vitro digestion model.

    Science.gov (United States)

    Daly, Trevor; Jiwan, Marvin A; O'Brien, Nora M; Aherne, S Aisling

    2010-06-01

    Herbs are a rich source of bioactive phytochemicals such as carotenoids, which are known to exert various positive biological effects. However, there is very limited information in the literature regarding the content and bioavailability of carotenoids from commonly consumed herbs. Therefore, the objectives of the present study were first, to determine the carotenoid content of eight herbs namely basil (Ocimum basilicum), coriander (Coriandrum sativum), dill (Anethum graveolens), mint (Metha L.), parsley (Petroselinum crispum), rosemary (Rosmarinus officinalis), sage (Salvia officinalis), and tarragon (Artemisia dracunculus L.); and second, to assess carotenoid bioaccessibility from these herbs using a simulated human in vitro digestion model. Carotenoid bioaccessibility is defined as the amount of carotenoids transferred to micelles after digestion when compared with the original amount present in the food. The content of individual carotenoids varied significantly among the herbs tested. Carotenoid bioaccessibility varied from 0 to 42.8%. Basil and coriander, and their respective micelles, contained the highest levels of beta-carotene, beta-cryptoxanthin, and lutein + zeaxanthin. Our findings show that herbs are rich sources of carotenoids and that these foods can significantly contribute to the intake of bioaccessible carotenoids. PMID:20443063

  10. THE CONTENT MODEL AND THE EQUATIONS OF MOTION OF ELECTRIC VEHICLE

    Directory of Open Access Journals (Sweden)

    K. O. Soroka

    2015-06-01

    Full Text Available Purpose. The calculation methods improvement of the electric vehicle curve movement and the cost of electricity with the aim of performance and accuracy of calculations improving are considered in the paper. Methodology. The method is based upon the general principles of mathematical simulation, when a conceptual model of problem domain is created and then a mathematic model is formulated according to the conceptual model. Development of an improved conceptual model of electric vehicles motion is proposed and a corresponding mathematical model is studied. Findings. The authors proposed model in which the vehicle considers as a system of interacting point-like particles with defined interactions under the influence of external forces. As a mathematical model the Euler-Lagrange equation of the second kind is used. Conservative and dissipative forces affecting the system dynamics are considered. Equations for calculating motion of electric vehicles with taking into account the energy consumption are proposed. Originality. In the paper the conceptual model of motion for electric vehicles with distributed masses has been developed as a system of interacting point-like particles. In the easiest case the system has only one degree of freedom. The mathematical model is based on Lagrange equations. The shown approach allows a detailed and physically based description of the electric vehicles dynamics. The derived motion equations for public electric transport are substantially more precise than the equations recommended in textbooks and the reference documentation. The motion equations and energy consumption calculations for transportation of one passenger with a trolleybus are developed. It is shown that the energy consumption depends on the data of vehicle and can increase when the manload is above the certain level. Practical value. The authors received the equations of motion and labour costs in the calculations focused on the use of computer methods

  11. Weakly nonlinear models for internal waves: inverse scattering transform and solitary wave contents

    CERN Document Server

    Chen, Shengqian

    2016-01-01

    The time evolution emanating from ``internal dam-break'' initial conditions is studied for a class of models of stratified Euler fluids in configurations close to two-homogeneous layers separated by a thin diffused interface. Direct numerical simulations and experiments in wave tanks show that such initial conditions eventually give rise to coherent structures that are close to solitary-wave solutions moving ahead of a region of dispersive wave motion and turbulent mixing close to the location of the initial dam step. A priori theoretical predictions of the main features of these solitary waves, such as their amplitudes and speeds, appear to be unavailable, even for simplified models of wave evolution in stratified fluids. With the aim of providing estimates of the existence, amplitude and speed of such solitary waves, an approach based on Inverse Scattering Transform (IST) for completely integrable models is developed here and tested against direct numerical simulations of Euler fluids and some of their mode...

  12. Effects of Video Modeling on Implementation of Literature Circles in Inclusive Content Area Classrooms

    Directory of Open Access Journals (Sweden)

    Lisa A. Dieker

    2008-07-01

    Full Text Available Trends in special education favor inclusion and concurrently the implementation of inclusive instructional practices. As students with learning disabilities are increasingly placed in general education classrooms, the need to assist general educators in establishing inclusive classrooms becomes a major priority. Cooperative learning, in the form of literature circles, is offered as a means of providing support to academically diverse student populations. In light of research-to-practice challenges, this study investigated the potential for students with learning disabilities and their peers to learn about literature circles by viewing video models of the practice in action. Students in the video modeling group demonstrated significantly more effective implementation of literature circles including cooperative behaviors, suggesting that video modeling could serve as a means of improving the translation of research on effective instructional strategies to actual practice in classrooms.

  13. A 1-D modelling of streaming potential dependence on water content during drainage experiment in sand

    CERN Document Server

    Allègre, Vincent; Ackerer, Philippe; Jouniaux, Laurence; Sailhac, Pascal; 10.1111/j.1365-246X.2012.05371.x

    2012-01-01

    The understanding of electrokinetics for unsaturated conditions is crucial for numerous of geophysical data interpretation. Nevertheless, the behaviour of the streaming potential coefficient C as a function of the water saturation Sw is still discussed. We propose here to model both the Richards' equation for hydrodynamics and the Poisson's equation for electrical potential for unsaturated conditions using 1-D finite element method. The equations are first presented and the numerical scheme is then detailed for the Poisson's equation. Then, computed streaming potentials (SPs) are compared to recently published SP measurements carried out during drainage experiment in a sand column. We show that the apparent measurement of DV / DP for the dipoles can provide the SP coefficient in these conditions. Two tests have been performed using existing models for the SP coefficient and a third one using a new relation. The results show that existing models of unsaturated SP coefficients C(Sw) provide poor results in term...

  14. The Wheel Model of STEAM Education Based on Traditional Korean Scientific Contents

    Science.gov (United States)

    Kim, Pyoung Won

    2016-01-01

    The Korean STEAM education pursues a convergent human resources education, but there are shortcomings associated with it due to the fact that it excludes the Humanities in its curriculum. This study embodies the accomplishments from the design and field application of the STEAM education model that has added Humanities fields (history, geography,…

  15. Integrating Geriatric Content into a Medical School Curriculum: Description of a Successful Model

    Science.gov (United States)

    Newell, Debra A.; Raji, Mukaila; Lieberman, Steven; Beach, Robert E.

    2004-01-01

    Most medical school curricula do not equip students with adequate attitudes, knowledge and skills to care for elderly populations. We describe an effective geriatric curricular infusion model compatible with preserving the overall curricula schema. Course and clerkship directors, staff and faculty from the Office of Educational Development, Center…

  16. Extension of the Hapke bidirectional reflectance model to retrieve soil water content

    Directory of Open Access Journals (Sweden)

    G.-J. Yang

    2011-07-01

    Full Text Available Soil moisture links the hydrologic cycle and the energy budget of land surfaces by regulating latent heat fluxes. An accurate assessment of the spatial and temporal variation of soil moisture is important to the study of surface biogeophysical processes. Although remote sensing has proven to be one of the most powerful tools for obtaining land surface parameters, no effective methodology yet exists for in situ soil moisture measurement based on a Bidirectional Reflectance Distribution Function (BRDF model, such as the Hapke model. To retrieve and analyze soil moisture, this study applied the soil water parametric (SWAP-Hapke model, which introduced the equivalent water thickness of soil, to ground multi-angular and hyperspectral observations coupled with, Powell-Ant Colony Algorithm methods. The inverted soil moisture data resulting from our method coincided with in situ measurements (R2 = 0.867, RMSE = 0.813 based on three selected bands (672 nm, 866 nm, 2209 nm. It proved that the extended Hapke model can be used to estimate soil moisture with high accuracy based on the field multi-angle and multispectral remote sensing data.

  17. Extension of the Hapke bidirectional reflectance model to retrieve soil water content

    Directory of Open Access Journals (Sweden)

    G.-J. Yang

    2011-04-01

    Full Text Available Soil moisture links the hydrologic cycle and the energy budget of land surfaces by regulating latent heat fluxes. An accurate assessment of the spatial and temporal variation of soil moisture is important to the study of surface biogeophysical processes. Although remote sensing has proven to be one of the most powerful tools for obtaining land surface parameters, no effective methodology yet exists for in situ soil moisture measurement based on a Bidirectional Reflectance Distribution Function (BRDF model, such as the Hapke model. To retrieve and analyze soil moisture, this study applied the soil water parametric (SWAP-Hapke model, which introduced the equivalent water thickness of soil, to ground multi-angular and hyperspectral observations coupled with, Powell–Ant Colony Algorithm methods. The inverted soil moisture data resulting from our method coincided with in situ measurements (R2 = 0.867, RMSE = 0.813 based on three selected bands (672 nm, 866 nm, 2209 nm. It proved that the extended Hapke model can be used to estimate soil moisture with high accuracy based on the field multi-angle and multispectral remote sensing data.

  18. Physiological loading can restore the proteoglycan content in a model of early IVD degeneration.

    Directory of Open Access Journals (Sweden)

    Rahul Gawri

    Full Text Available A hallmark of early IVD degeneration is a decrease in proteoglycan content. Progression will eventually lead to matrix degradation, a decrease in weight bearing capacity and loss of disc height. In the final stages of IVD degradation, fissures appear in the annular ring allowing extrusion of the NP. It is crucial to understand the interplay between mechanobiology, disc composition and metabolism to be able to provide exercise recommendations to patients with early signs of disc degeneration. This study evaluates the effect of physiological loading compared to no loading on matrix homeostasis in bovine discs with induced degeneration. Bovine discs with trypsin-induced degeneration were cultured for 14 days in a bioreactor under dynamic loading with maintained metabolic activity. Chondroadherin abundance and structure was used to confirm that a functional matrix was preserved in the chosen loading environment. No change was observed in chondroadherin integrity and a non-significant increase in abundance was detected in trypsin-treated loaded discs compared to unloaded discs. The proteoglycan concentration in loaded trypsin-treated discs was significantly higher than in unloaded disc and the newly synthesised proteoglycans were of the same size range as those found in control samples. The proteoglycan showed an even distribution throughout the NP region, similar to that of control discs. Significantly more newly synthesised type II collagen was detected in trypsin-treated loaded discs compared to unloaded discs, demonstrating that physiological load not only stimulates aggrecan production, but also that of type II collagen. Taken together, this study shows that dynamic physiological load has the ability to repair the extracellular matrix depletion typical of early disc degeneration.

  19. Wideband On-ground Monostatic Radar Antenna for Water Content Soil Evaluation: Modeling, Design and Testing

    Science.gov (United States)

    Vitale, Q.; Rejiba, F.; Guérin, R.

    2012-12-01

    The knowledge of soil's hydraulic properties spatial distribution is important in agricultural practice optimization and hydrological studies. Non-invasive methods of measurement of the dielectric permittivity such as time domain reflectometry (TDR) and ground penetrating radar (GPR) are increasingly used in order to asses soil water content at the field scale. In order to acquire radar data over a wide frequency range, we designed a simple on-ground radar antenna operating on the frequency range 350 MHz - 2GHz. The antenna was designed using a powerful commercial three dimensional finite-difference time-domain (FDTD) electromagnetic field solver. A prototype of the frequency type radar transmission link was constructed and laboratory measurements were first performed with calibration purpose (the antenna was placed on a 13 cm-thick sand layer of known dielectric permittivity). The antenna is used in monostatic configuration and associated with a vector network analyzer to perform measurements of the antenna-soil reflection coefficients (S11) in the frequency domain. Those measurements are compared to FDTD simulations using the root mean square criterion in order to assess the sand dielectric properties. The use of full-wave FDTD software allows simulation of the whole antenna components, thus all potential influence on the reflection coefficient are recorded. The estimated permittivity with this procedure was close to the real one. In order to test the prototype in real field conditions measurements were performed on a single profile characterized by several agricultural practices (wheat crop, vegetative buffer strip and corn crop). Reflection coefficient (S11) measurements acquired with the prototype are compared to TDR measurements and DC electrical soundings in order to validate the soil apparent dielectric permittivity as well as its apparent electrical conductivity.

  20. Prevention of cancer and the dose-effect relationship: the carcinogenic effects of ionizing radiations

    International Nuclear Information System (INIS)

    seldom occur. Promoting factors are agents that either perturb intercellular signalling or stimulate cell proliferation (e.g. hormones) or increase cell mortality: mechanical or chemical irritation (e.g. alcohol, bacteria, viruses) thereby inducing compensatory cell proliferation. Thus, gradually pre-cancerous cells become able to divide more rapidly with greater autonomy. This phase ends when a sub clone of cells has acquired the capacity of autonomous proliferation. The third phase is that of progression during which cells proliferate regularly without any stimulation. In one of the cells of one of the pre-cancerous lesions (e.g. polyps) a cell acquires the capacity of invading surrounding tissue or to metastasize. The whole carcinogenic process is very slow, extending over several decades, because the specific mutations seldom occur and the probability of an accumulation of several specific mutations in the same cell or cell lineage is very small. It can be accelerated by intense stimulation of cell proliferation or genetic instability. Ionizing radiations act firstly as a mutagen, however when the dose is high they also kill a significant proportion of cells and by a homeostatic mechanism they induce cell proliferation and clonal amplification. It has been claimed that even the smallest dose of radiation can induce a cancer. This concept is associated with the L.N.T. model and it is not based on scientific evidence. It has fuelled a fear of radiation which had detrimental consequences. Conversely the high efficacy of defense mechanisms against radio carcinogenesis, particularly when the tissue is not disorganized, can explain the lack of carcinogenic effect of contamination by small doses of radium or thorium which has been observed on radium dial painters or in patients injected with thorotrast. The study of second cancers in patients treated by radiotherapy could provide important information and should be actively pursued with two aims: reduce the incidence of

  1. Ionospheric total electron content variations observed before earthquakes: Possible physical mechanism and modeling

    CERN Document Server

    Namgaladze, A A; Zakharenkova, I E; Shagimuratov, I I; Martynenko, O V

    2009-01-01

    The GPS derived anomalous TEC disturbances before earthquakes were discovered in the last years using global and regional TEC maps, measurements over individual stations as well as measurements along individual GPS satellite passes. For strong mid-latitudinal earthquakes the seismo-ionospheric anomalies look like local TEC enhancements or decreases located in the vicinity of the forthcoming earthquake epicenter In case of strong low-latitudinal earthquakes there are effects related with the modification of the equatorial F2-region anomaly: deepening or filling of the ionospheric electron density trough over the magnetic equator. We consider that the most probable reason of the NmF2 and TEC disturbances observed before the earthquakes is the vertical drift of the F2-region ionospheric plasma under the influence of the zonal electric field of seismic origin. To check this hypothesis, the model calculations have been carried out with the use of the Upper Atmosphere Model. The electric potential distribution at t...

  2. Model rules and parameter studies for the volumetric steam content in a two-phase flow

    International Nuclear Information System (INIS)

    A comparison of the existing measured and calculated void-fraction data for water still shows some discrepancy. New measurements have been carried out to investigate these deviations. The refrigerant R113 has been used as a working fluid in order to reduce the high cost of experiments with water when a large range of system parameters are to be changed. Scaling criterion for the void-fraction are deduced for R113 from the experimental data and for water from data given in the literature. Using this fluid to fluid modelling further investigations were carried out to obtain the effect of the distribution parameter C0 on the average void-fraction. The Zuber and Findlay model for the determination of the mean void-fraction has been modified in order to obtain a larger parameter range for water, R12, R113, and R114. (Auth.)

  3. Estimation of Spruce Needle-Leaf Chlorophyll Content Based on DART and PARAS Canopy Reflectance Models

    Czech Academy of Sciences Publication Activity Database

    Yáñez-Rausell, L.; Malenovský, Z.; Rautiainen, M.; Clevers, J G P W.; Lukeš, Petr; Hanuš, Jan; Schaepman, M. E.

    2015-01-01

    Roč. 8, č. 4 (2015), s. 1534-1544. ISSN 1939-1404 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : Chlorophyll a plus b estimation * CHRIS-PROBA * coniferous forest * continuum removal * discrete anisotropic radiative transfer model (DART) * needle-leaf * Norway spruce * optical indices * PARAS * PROSPECT * radiative transfer * recollision probability Subject RIV: EH - Ecology, Behaviour Impact factor: 3.026, year: 2014

  4. EVALUATION OF ANTIOXIDANT AND TOTAL FLAVANOID CONTENT OF MIRABILIS JALAPA LINN USING IN VITRO MODELS

    OpenAIRE

    Subin Mary Zachariah; Aleykutty, N. A.; Jaykar, B; Vidya Viswanad; Halima.O.A

    2012-01-01

    The herbal drugs form the backbone of all traditional system of medicine around the world due to their endless therapeutic activity. Mirabilis jalapa Linn has been hailed as a cure for many common pathological conditions affecting the human body. It has folkloric use as antinociceptive, anti-inflammatory agent, laxative, and a host of other uses. The present study was conducted to evaluate the plants potential as an antioxidant lead by using various in vitro models like FRAP (Ferric reducing...

  5. House-heating emissions of carcinogenic substances. A problem of the new lander in Germany

    International Nuclear Information System (INIS)

    Intensive studies and analyses have been done to set up an air pollution management plan for an area of 752 km2 in the south of Saxony-Anhalt (182 000 inhabitants), the first one in the New Lander of Germany. The results show a higher level of harmful compounds in the ambient air in densly-populated areas, especially caused by exhaust gases from brown-coal (lignite) fired residential stoves. The combustion of indigenous lignite-briquettes with a high content of sulphur causes classical inorganic emissions, such as carbon monoxide (CO), sulphur dioxide (SO2), particulate matter and nitrogen oxides (NOx) as well as organic compounds, such as benzene, toluene, xylene (BTX), polycyclic aromatic hydrocarbons (PAH) and polychlorinated dioxins and furans (PCDD/F). The last-named are of special importance because of the carcinogenic effects. An inventory of house-heating facilities, set up on the basis of energy consumption for heating purposes in buildings, shows the still very high part of brown coal combustion (58 %) in the investigated area and in the New Lander of Germany. In the western part of Germany this percentage amounts only to 10 %. (orig.)

  6. Incorporating moisture content in modeling the surface energy balance of debris-covered Changri Nup Glacier, Nepal

    Science.gov (United States)

    Giese, Alexandra; Boone, Aaron; Morin, Samuel; Lejeune, Yves; Wagnon, Patrick; Dumont, Marie; Hawley, Robert

    2016-04-01

    Glaciers whose ablation zones are covered in supraglacial debris comprise a significant portion of glaciers in High Mountain Asia and two-thirds in the South Central Himalaya. Such glaciers evade traditional proxies for mass balance because they are difficult to delineate remotely and because they lose volume via thinning rather than via retreat. Additionally, their surface energy balance is significantly more complicated than their clean counterparts' due to a conductive heat flux from the debris-air interface to the ice-debris boundary, where melt occurs. This flux is a function of the debris' thickness; thermal, radiative, and physical properties; and moisture content. To date, few surface energy balance models have accounted for debris moisture content and phase changes despite the fact that they are well-known to affect fluxes of mass, latent heat, and conduction. In this study, we introduce a new model, ISBA-DEB, which is capable of solving not only the heat equation but also moisture transport and retention in the debris. The model is based upon Meteo-France's Interactions between Soil, Biosphere, and Atmosphere (ISBA) soil and vegetation model, significantly adapted for debris and coupled with the snowpack model Crocus within the SURFEX platform. We drive the model with continuous ERA-Interim reanalysis data, adapted to the local topography (i.e. considering local elevation and shadowing) and downscaled and de-biased using 5 years of in-situ meteorological data at Changri Nup glacier [(27.859N, 86.847E)] in the Khumbu Himal. The 1-D model output is then evaluated through comparison with measured temperature in and ablation under a 10-cm thick debris layer on Changri Nup. We have found that introducing a non-equilibrium model for water flow, rather than using the mixed-form Richard's equation alone, promotes greater consistency with moisture observations. This explicit incorporation of moisture processes improves simulation of the snow-debris-ice column

  7. Carcinogenic effect of sequential artificial sunlight and UV-A irradiation in hairless mice. Consequences for solarium 'therapy'

    International Nuclear Information System (INIS)

    The carcinogenic effect of artificial UV sunlight followed by UV-A irradiation in human solaria doses has been studied with the use of the hairless mouse as an animal model. Artificial sunlight exposure alone induced only a moderate skin tumor incidence (animals with at least one tumor) of 0.15 after one year, and UV-A irradiation alone induced no tumor formation. However, the combination of artificial sunlight exposure and subsequent UV-A irradiation significantly increased the tumor incidence to 0.72. We conclude that, in humans, tanning with UV-A for cosmetic purposes may not be an innocuous procedure

  8. Carcinogenic effect of sequential artificial sunlight and UV-A irradiation in hairless mice. Consequences for solarium 'therapy'.

    Science.gov (United States)

    Staberg, B; Wulf, H C; Poulsen, T; Klemp, P; Brodthagen, H

    1983-08-01

    The carcinogenic effect of artificial UV sunlight followed by UV-A irradiation in human solaria doses has been studied with the use of the hairless mouse as an animal model. Artificial sunlight exposure alone induced only a moderate skin tumor incidence (animals with at least one tumor) of 0.15 after one year, and UV-A irradiation alone induced no tumor formation. However, the combination of artificial sunlight exposure and subsequent UV-A irradiation significantly increased the tumor incidence to 0.72. We conclude that, in humans, tanning with UV-A for cosmetic purposes may not be an innocuous procedure. PMID:6870317

  9. A Novel Model of Resolving Contention in Optical Burst Switched Networks

    Institute of Scientific and Technical Information of China (English)

    Huang Anpeng(黄安鹏); Xie Linzhen; Li Jingcong; Li Zhengbin; Xu Anshi

    2004-01-01

    A Novel segmentation and feedback model (SFM) applied to resolve collision has been proposed. The SFM is featured with Burst Segmentation and Prioritized Feedback (BSPF) that are used to provide quality of service (QoS) and realize high throughput and faster switching in the optical burst switched networks. Simulation and performance analyses show that the SFM effectively avoid collision in optical burst switching (OBS). Long delay time of deflection routing and immature technology of wavelength converter and optical buffer are not employed in the SFM. The SFM not only realizes quick switching but also allows preemption for higher priority bursts.

  10. Unidirectional high fiber content composites: Automatic 3D FE model generation and damage simulation

    DEFF Research Database (Denmark)

    Qing, Hai; Mishnaevsky, Leon

    2009-01-01

    A new method and a software code for the automatic generation of 3D micromechanical FE models of unidirectional long-fiber-reinforced composite (LFRC) with high fiber volume fraction with random fiber arrangement are presented. The fiber arrangement in the cross-section is generated through random...... movements of fibers from their initial regular hexagonal arrangement. Damageable layers are introduced into the fibers to take into account the random distribution of the fiber strengths. A series of computational experiments on the glass fibers reinforced polymer epoxy matrix composite is performed to...

  11. Information content in $F(R)$ brane models with non-constant curvature

    CERN Document Server

    Correa, R A C; Dutra, A de Souza; da Rocha, Roldao; Menezes, R

    2015-01-01

    In this work we investigate the entropic information-measure in the context of braneworlds with non-constant curvature. The braneworld entropic information is studied for gravity modified by the squared of the Ricci scalar, besides the usual Einstein-Hilbert term. We showed that the minimum value of the brane configurational entropy provides a stricter bound on the parameter that is responsible for the $F(R)$ model to differ from the Einstein-Hilbert standard one. Our results are moreover consistent to a negative bulk cosmological constant.

  12. A multivariate regression model for detection of fumonisins content in maize from near infrared spectra.

    Science.gov (United States)

    Giacomo, Della Riccia; Stefania, Del Zotto

    2013-12-15

    Fumonisins are mycotoxins produced by Fusarium species that commonly live in maize. Whereas fungi damage plants, fumonisins cause disease both to cattle breedings and human beings. Law limits set fumonisins tolerable daily intake with respect to several maize based feed and food. Chemical techniques assure the most reliable and accurate measurements, but they are expensive and time consuming. A method based on Near Infrared spectroscopy and multivariate statistical regression is described as a simpler, cheaper and faster alternative. We apply Partial Least Squares with full cross validation. Two models are described, having high correlation of calibration (0.995, 0.998) and of validation (0.908, 0.909), respectively. Description of observed phenomenon is accurate and overfitting is avoided. Screening of contaminated maize with respect to European legal limit of 4 mg kg(-1) should be assured. PMID:23993617

  13. Classification of weakly carcinogenic human papillomavirus types: addressing the limits of epidemiology at the borderline

    Directory of Open Access Journals (Sweden)

    Buonaguro Franco M

    2009-06-01

    Full Text Available Abstract Virtually all cases of cervical cancer are caused by persistent infections with a restricted set of human papillomaviruses (HPV. Some HPV types, like HPV16 and HPV18, are clear and powerful carcinogens. However, the categorization of the most weakly carcinogenic HPV types is extremely challenging. The decisions are important for screening test and vaccine development. This article describes for open discussion an approach recently taken by a World Health Organization International Agency for Research on Cancer (IARC Monographs Working Group to re-assess the carcinogenicity of different HPV types.

  14. Spatiotemporal variations of water vapor content over Ethiopia: A study using GPS observations and ECMWF model

    Science.gov (United States)

    Abraha, Kibrom; Masson, Frédéric; Doubre, Cécile; Boy, Jean-Paul; Lewi, Elias

    2014-05-01

    In this study we characterize the spatial and temporal variability of integrated water vapour (IWV) in Ethiopa from a network of GPS stations. Water vapour plays a major role in atmospheric processes but remains difficult to quantify due to its high variability in time and space and the sparse set of available measurements. Global Positioning Systems (GPS) has demonstrated its ability to monitor IWV with an accuracy comparable to other means of measurements (radiosondes, microwave radiometers, …) and a good time resolution and under all meteorological conditions. IWV values for a set of Ethiopian GPS stations have been estimated from 2007 to 2011. They have also been extracted from European Centre for Medium-Range Weather Forecasts (ECMWF) model, using nearest point from the original reduced Gaussian grid. First we compare the IVW estimated from GPS and from the model. The bias varies from site to site but in general a bias of less than 1 kg/m2 was analysed in the ECMWF data set with respect to GPS observations. The correlations between the two data sets exceed 0.85 at different time scales at a 99.9% significant level. Second we observe the spatial variation of the IWV. High values are obtained in those stations that are located in north-eastern (Afar depression sites) and south-western part of the country. This distribution is related to the spatial variability of the climate in Ethiopia. Finally, we study the diurnal, seasonal cycle and inter-annual variability of IWV for all stations over Ethiopia. The main result is the strong inter-annual variability observed for the dry seasons.

  15. Childhood cancer: Overview of incidence trends and environmental carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Zahm, S.H.; Devesa, S.S. [National Cancer Inst., Rockville, MD (United States)

    1995-09-01

    An estimated 8000 children 0 to 14 years of age are diagnosed annually with cancer in the United States. Leukemia and brain tumors are the most common childhood malignancies, accounting for 30 and 20% of newly diagnosed cases, respectively. From 1975 to 1978 to 1987 to 1990, cancer among white children increased slightly from 12.8 to 14.1/100,000. Increases are suggested for leukemia, gliomas, and, to a much lesser extent, Wilms` tumor. There are a few well-established environmental causes of childhood cancer such as radiation, chemotherapeutic agents, and diethylstilbestrol. Many other agents such as electromagnetic fields, pesticides, and some parental occupational exposures are suspected of playing roles, but the evidence is not conclusive at this time. Some childhood exposures such as secondhand cigarette smoke may contribute to cancers that develop many years after childhood. For some exposures such as radiation and pesticides data suggest that children may be more susceptible to the carcinogenic effects than similarly exposed adults. 143 refs., 1 fig., 3 tabs.

  16. Urban air carcinogens and their effects on health

    Energy Technology Data Exchange (ETDEWEB)

    Lechner, J.F.

    1994-11-01

    Airborne carcinogens may be relevant especially in metropolitan regions with extreme smog as a primary cause of lung cancer. Lung cancer is most common in urban environs and the incidence directly correlates with the size of the city. In addition, several, but not all formal epidemiological studies also suggest a positive correlation between lung cancer incidence and the intensity of air pollution exposure. There is further support for a role of air pollution; as of 1993, 4.4% of all of the bronchogenic adenocarcinoma cancer cases among Mexicans living in industrialized cities are under 40 years of age. It is plausible that chronic inhalation of automobile combustion products, factory emissions, and/or radon is at least partially responsible for the higher incidence of lung cancer exemplified by the never-smoking urban residents. The exceptionally high incidence of lung cancer cases among never-smokers living in highly industrialized Mexican cities offers a unique opportunity to use molecular epidemiology to test whether chronic inhalation of atmospheric pollutants increases the risk for this disease. Overall, the analysis of the genetic alterations in two cancer genes, and possibly the hprt locus should give new insight as to whether the urban never-smokers developed their cancers because of exposure to environmental pollutants.

  17. [Urban air pollution by carcinogenic N-nitrosamines].

    Science.gov (United States)

    Khesina, A Ia; Krivosheeva, L V; Sokol'skaia, N N; Koliadich, M N

    1996-01-01

    Moscow is used as an example to discuss the problem of urban atmospheric pollution by carcinogenic N-nitrosamines. An analytical method is proposed, which is based on the use of a Russian gas chromatograph compatible with a chemiluminescence detector, that is a TEA thermal energy analyzer (USA) having some modifications to reduce the time of analysis and loss during sample pretreatment. The minimal detected concentration is 3 ng/m3 for 2-hour sampling. The method identifies and quantifies 7 volatile N-nitrosamines: N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine, N-nitrosodibutylamine, N-nitrosodipropylamine, N-nitrosopiperidine, N-nitrosopyrrolidine, N-nitrosomorpholine. The pollution of the Moscow air was evaluated in the center of Moscow (30-60 ng/m3 for NDMA), in the industrial emission area (as high as several hundred ng/m3, and in the heavy traffic area (100 ng/m3 or more). It is proposed to study the working area for rubber and tire industries, to establish nitrosamine tolerances for these industries and maximum allowable discharge concentrations in the urban air and to monitor these parameters. PMID:8672956

  18. A Hybrid Probabilistic Model for Unified Collaborative and Content-Based Image Tagging.

    Science.gov (United States)

    Zhou, Ning; Cheung, William K; Qiu, Guoping; Xue, Xiangyang

    2011-07-01

    The increasing availability of large quantities of user contributed images with labels has provided opportunities to develop automatic tools to tag images to facilitate image search and retrieval. In this paper, we present a novel hybrid probabilistic model (HPM) which integrates low-level image features and high-level user provided tags to automatically tag images. For images without any tags, HPM predicts new tags based solely on the low-level image features. For images with user provided tags, HPM jointly exploits both the image features and the tags in a unified probabilistic framework to recommend additional tags to label the images. The HPM framework makes use of the tag-image association matrix (TIAM). However, since the number of images is usually very large and user-provided tags are diverse, TIAM is very sparse, thus making it difficult to reliably estimate tag-to-tag co-occurrence probabilities. We developed a collaborative filtering method based on nonnegative matrix factorization (NMF) for tackling this data sparsity issue. Also, an L1 norm kernel method is used to estimate the correlations between image features and semantic concepts. The effectiveness of the proposed approach has been evaluated using three databases containing 5,000 images with 371 tags, 31,695 images with 5,587 tags, and 269,648 images with 5,018 tags, respectively. PMID:21079279

  19. Predicting moisture content and density distribution of Scots pine by microwave scanning of sawn timber II: Evaluation of models generated on a pixel level

    International Nuclear Information System (INIS)

    The purpose of this study was to use images from a microwave sensor on a pixel level for simultaneous prediction of moisture content and density of wood. The microwave sensor functions as a line-scan camera with a pixel size of 8mm. Boards of Scots pine (Pinus sylvestris), 25 and 50mm thick, were scanned at three different moisture contents. Dry density and moisture content for each pixel were calculated from measurements with a computed tomography scanner. It was possible to create models for prediction of density on a pixel level. Models for prediction of moisture content had to be based on average values over homogeneous regions. Accuracy will be improved if it is possible to make a classification of knots, heartwood, sapwood, etc., and calibrate different models for different types of wood. The limitations of the sensor used are high noise in amplitude measurements and the restriction to one period for phase measurements

  20. Oxygen consumption by oak chips in a model wine solution; Influence of the botanical origin, toast level and ellagitannin content.

    Science.gov (United States)

    Navarro, María; Kontoudakis, Nikolaos; Giordanengo, Thomas; Gómez-Alonso, Sergio; García-Romero, Esteban; Fort, Francesca; Canals, Joan Miquel; Hermosín-Gutíerrez, Isidro; Zamora, Fernando

    2016-05-15

    The botanical origin, toast level and ellagitannin content of oak chips in a model wine solution have been studied in terms of their influence on oxygen consumption. French oak chips released significantly higher amounts of ellagitannins than American oak chips at any toast level. The release of ellagitannins by oak chips decreased as the toast level increased in the French oak but this trend was not so clear in American oak. Oxygen consumption rate was clearly related to the level of released ellagitannins. Therefore, oak chips should be chosen for their potential to release ellagitannins release should be considered, not only because they can have a direct impact on the flavor and body of the wine, but also because they can protect against oxidation. PMID:26776040

  1. Thermal remote sensing of surface soil water content with partial vegetation cover for incorporation into climate models

    Science.gov (United States)

    Gillies, Robert R.; Carlson, Toby N.

    1995-01-01

    This study outlines a method for the estimation of regional patterns of surface moisture availability (M(sub 0)) and fractional vegetation (Fr) in the presence of spatially variable vegetation cover. The method requires relating variations in satellite-derived (NOAA, Advanced Very High Resolution Radiometer (AVHRR)) surface radiant temperature to a vegetation index (computed from satellite visible and near-infrared data) while coupling this association to an inverse modeling scheme. More than merely furnishing surface soil moisture values, the method constitues a new conceptual and practical approach for combining thermal infrared and vegetation index measurements for incorporating the derived values of M(sub 0) into hydrologic and atmospheric prediction models. Application of the technique is demonstrated for a region in and around the city of Newcastle upon Tyne situated in the northeast of England. A regional estimate of M(sub 0) is derived and is probabbly good for fractional vegetation cover up to 80% before errors in the estimated soil water content become unacceptably large. Moreover, a normalization scheme is suggested from which a nomogram, `universal triangle,' is constructed and is seen to fit the observed data well. The universal triangle also simplifies the inclusion of remotely derived M(sub 0) in hydrology and meteorological models and is perhaps a practicable step toward integrating derived data from satellite measurements in weather forecasting.

  2. Mutagens and carcinogens - Occurrence and role during chemical and biological evolution

    Science.gov (United States)

    Giner-Sorolla, A.; Oro, J.

    1981-01-01

    The roles of mutagenic and carcinogenic substances in early biologic evolution is examined, along with terrestrial and extraterrestrial sources of mutagens and carcinogens. UV solar radiation is noted to have served to stimulate prebiotic life while also causing harmful effects in plants and animals. Aromatic compounds have been found in meteorites, and comprise leukemogens, polycyclic hydrocarbons, and nitrasamine precursors. Other mutagenic sources are volcanoes, and the beginning of evolution with mutagenic substances is complicated by the appearance of malignancies due to the presence of carcinogens. The atmosphere of the Precambrian period contained both mutagens and early carcinogens and, combined with volcanic activity discharges, formed an atmospheric chemical background analogous to the background ionizing radiation. Carcinogenesis is concluded to be intrinsic to nature, having initiated evolution and, eventually, cancer cells.

  3. AI AND SAR APPROACHES FOR PREDICTING CHEMICAL CARCINOGENICITY: SURVEY AND STATUS REPORT

    Science.gov (United States)

    A wide variety of artificial intelligence (AI) and structure-activity relationship (SAR approaches have been applied to tackling the general problem of predicting rodent chemical carcinogenicity. Given the diversity of chemical structures and mechanisms relative to this endpoin...

  4. An investigation of carcinogenic agents at the Mississippi Sandhill Crane National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a study with the following results: 1. Three of the metals reported as carcinogens, arsenic, chromium, and nickel, were found within the...

  5. 78 FR 15020 - Report on Carcinogens Webinar on Pentachlorophenol; Notice of Public Webinar and Registration...

    Science.gov (United States)

    2013-03-08

    ... HUMAN SERVICES National Institutes of Health Report on Carcinogens Webinar on Pentachlorophenol; Notice of Public Webinar and Registration Information SUMMARY: The National Toxicology Program (NTP) announces a public webinar, ``Human cancer studies on exposure to pentachlorophenol (PCP):...

  6. A review of biosensing techniques for detection of trace carcinogen contamination in food products.

    Science.gov (United States)

    Li, Zhanming; Yu, Yue; Li, Zhiliang; Wu, Tao

    2015-04-01

    Carcinogen contaminations in the food chain, for example heavy metal ions, pesticides, acrylamide, and mycotoxins, have caused serious health problems. A major objective of food-safety research is the identification and prevention of exposure to these carcinogens, because of their impossible-to-reverse tumorigenic effects. However, carcinogen detection is difficult because of their trace-level presence in food. Thus, reliable and accurate separation and determination methods are essential to protect food safety and human health. This paper summarizes the state of the art in separation and determination methods for analyzing carcinogen contamination, especially the advances in biosensing methods. Furthermore, the application of promising technology including nanomaterials, imprinted polymers, and microdevices is detailed. Challenges and perspectives are also discussed. PMID:25694149

  7. 78 FR 57868 - Nominations to the Report on Carcinogens; Request for Information

    Science.gov (United States)

    2013-09-20

    ... RoC. 20 Substances Nominated to the RoC* Aloe vera whole leaf extract (Aloe barbadensis Miller) 2..., ongoing, or planned studies related to evaluating carcinogenicity; (3) scientific issues important...

  8. Occupational toxicants. Critical data evaluation for MAK values and classification of carcinogens. Vol. 4

    International Nuclear Information System (INIS)

    33 occupational toxicants are reviewed. Data are presented according to toxic effects in animals and man, mode of action, carcinogenicity, genotoxicity, reproductive and development toxicity, and MAK value. (MG)

  9. Biomarkers for assessing potential carcinogenic effects of chronic arsenic exposure in Inner Mongolia, CHINA

    Science.gov (United States)

    Arsenic is ubiquitous in the environment. Chronic arsenic exposure via drinking water has been associated. with carcinogenic, cardiovascular, neurological and diabetic effects in humans and has been of great public health concern worldwide. In 2001, U.S. Environmental Protection ...

  10. Leisure time activities related to carcinogen exposure and lung cancer risk in never smokers. A case-control study

    Energy Technology Data Exchange (ETDEWEB)

    Ruano-Ravina, Alberto, E-mail: alberto.ruano@usc.es [Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela (Spain); CIBER de Epidemiología y Salud Pública CIBERESP, Barcelona (Spain); García-Lavandeira, José Antonio [Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela (Spain); Department of Preventive Medicine, A Coruña University Hospital Complex, Coruña (Spain); Torres-Durán, María [Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela (Spain); Service of Neumology, University Hospital Complex of Vigo, Vigo (Spain); Prini-Guadalupe, Luciana [Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela (Spain); Parente-Lamelas, Isaura [Service of Neumology, Ourense Hospital Complex, Ourense (Spain); Leiro-Fernández, Virginia [Service of Neumology, University Hospital Complex of Vigo, Vigo (Spain); Montero-Martínez, Carmen [Service of Neumology, University Hospital Complex of A Coruña, Coruña (Spain); González-Barcala, Francisco Javier; Golpe-Gómez, Antonio [Service of Neumology, Santiago de Compostela University Clinic Hospital, Santiago de Compostela (Spain); Martínez, Cristina [National Institute of Silicosis, University Hospital of Asturias, Oviedo, Asturias (Spain); Castro-Añón, Olalla [Service of Neumology, Hospital Lucus Augusti, Lugo (Spain); Mejuto-Martí, María José [Service of Neumology, Hospital Arquitecto Marcide, Ferrol (Spain); and others

    2014-07-15

    We aim to assess the relationship between leisure time activities related to exposure to carcinogenic substances and lung cancer risk in a hospital-based case-control study performed in never smokers. We included never smoking cases with anatomopathologically confirmed lung cancer and never smoking controls undergoing trivial surgery, at 8 Spanish hospitals. The study was conducted between January 2011 and June 2013. Participants were older than 30 and had no previous neoplasms. All were personally interviewed focusing on lifestyle, environmental tobacco smoke exposure, occupational history and leisure time activities (including duration of such activities). Results were analyzed through logistic regression and adjusted also by residential radon and education level. We included 513 never smokers, 191 cases and 322 controls. The OR for those performing the studied leisure time activities was 1.43 (95%CI 0.78–2.61). When we restricted the analysis to those performing do-it-yourself activities for more than 10 years the OR was 2.21 (95%CI 0.93–5.27). Environmental tobacco smoke exposure did not modify this association. The effect for the different lung cancer histological types was very close to significance for adenocarcinoma but only when these activities were performed for more than 10 years. We encourage health professionals to recommend protective measures for those individuals while performing these hobbies to reduce the risk of lung cancer. - Highlights: • Some leisure time activities are associated with the exposure to carcinogenic substances. • These activities are model-making, painting (artistic or not), furniture refinishing or wood working. • Few studies have assessed lung cancer risk due to these hobbies and none in never-smokers. • Leisure activities related to exposure to carcinogenic substances present higher lung cancer risk. • The risk is higher when these activities are performed for more than 10 years.

  11. Leisure time activities related to carcinogen exposure and lung cancer risk in never smokers. A case-control study

    International Nuclear Information System (INIS)

    We aim to assess the relationship between leisure time activities related to exposure to carcinogenic substances and lung cancer risk in a hospital-based case-control study performed in never smokers. We included never smoking cases with anatomopathologically confirmed lung cancer and never smoking controls undergoing trivial surgery, at 8 Spanish hospitals. The study was conducted between January 2011 and June 2013. Participants were older than 30 and had no previous neoplasms. All were personally interviewed focusing on lifestyle, environmental tobacco smoke exposure, occupational history and leisure time activities (including duration of such activities). Results were analyzed through logistic regression and adjusted also by residential radon and education level. We included 513 never smokers, 191 cases and 322 controls. The OR for those performing the studied leisure time activities was 1.43 (95%CI 0.78–2.61). When we restricted the analysis to those performing do-it-yourself activities for more than 10 years the OR was 2.21 (95%CI 0.93–5.27). Environmental tobacco smoke exposure did not modify this association. The effect for the different lung cancer histological types was very close to significance for adenocarcinoma but only when these activities were performed for more than 10 years. We encourage health professionals to recommend protective measures for those individuals while performing these hobbies to reduce the risk of lung cancer. - Highlights: • Some leisure time activities are associated with the exposure to carcinogenic substances. • These activities are model-making, painting (artistic or not), furniture refinishing or wood working. • Few studies have assessed lung cancer risk due to these hobbies and none in never-smokers. • Leisure activities related to exposure to carcinogenic substances present higher lung cancer risk. • The risk is higher when these activities are performed for more than 10 years

  12. An empirical model of ionospheric total electron content (TEC near the crest of the equatorial ionization anomaly (EIA

    Directory of Open Access Journals (Sweden)

    Hajra Rajkumar

    2016-01-01

    Full Text Available We present a geomagnetic quiet time (Dst > −50 nT empirical model of ionospheric total electron content (TEC for the northern equatorial ionization anomaly (EIA crest over Calcutta, India. The model is based on the 1980–1990 TEC measurements from the geostationary Engineering Test Satellite-2 (ETS-2 at the Haringhata (University of Calcutta, India: 22.58° N, 88.38° E geographic; 12.09° N, 160.46° E geomagnetic ionospheric field station using the technique of Faraday rotation of plane polarized VHF (136.11 MHz signals. The ground station is situated virtually underneath the northern EIA crest. The monthly mean TEC increases linearly with F10.7 solar ionizing flux, with a significantly high correlation coefficient (r = 0.89–0.99 between the two. For the same solar flux level, the TEC values are found to be significantly different between the descending and ascending phases of the solar cycle. This ionospheric hysteresis effect depends on the local time as well as on the solar flux level. On an annual scale, TEC exhibits semiannual variations with maximum TEC values occurring during the two equinoxes and minimum at summer solstice. The semiannual variation is strongest during local noon with a summer-to-equinox variability of ~50–100 TEC units. The diurnal pattern of TEC is characterized by a pre-sunrise (0400–0500 LT minimum and near-noon (1300–1400 LT maximum. Equatorial electrodynamics is dominated by the equatorial electrojet which in turn controls the daytime TEC variation and its maximum. We combine these long-term analyses to develop an empirical model of monthly mean TEC. The model is validated using both ETS-2 measurements and recent GNSS measurements. It is found that the present model efficiently estimates the TEC values within a 1-σ range from the observed mean values.

  13. An empirical model of ionospheric total electron content (TEC) near the crest of the equatorial ionization anomaly (EIA)

    Science.gov (United States)

    Hajra, Rajkumar; Chakraborty, Shyamal Kumar; Tsurutani, Bruce T.; DasGupta, Ashish; Echer, Ezequiel; Brum, Christiano G. M.; Gonzalez, Walter D.; Sobral, José Humberto Andrade

    2016-07-01

    We present a geomagnetic quiet time (Dst > -50 nT) empirical model of ionospheric total electron content (TEC) for the northern equatorial ionization anomaly (EIA) crest over Calcutta, India. The model is based on the 1980-1990 TEC measurements from the geostationary Engineering Test Satellite-2 (ETS-2) at the Haringhata (University of Calcutta, India: 22.58° N, 88.38° E geographic; 12.09° N, 160.46° E geomagnetic) ionospheric field station using the technique of Faraday rotation of plane polarized VHF (136.11 MHz) signals. The ground station is situated virtually underneath the northern EIA crest. The monthly mean TEC increases linearly with F10.7 solar ionizing flux, with a significantly high correlation coefficient (r = 0.89-0.99) between the two. For the same solar flux level, the TEC values are found to be significantly different between the descending and ascending phases of the solar cycle. This ionospheric hysteresis effect depends on the local time as well as on the solar flux level. On an annual scale, TEC exhibits semiannual variations with maximum TEC values occurring during the two equinoxes and minimum at summer solstice. The semiannual variation is strongest during local noon with a summer-to-equinox variability of ~50-100 TEC units. The diurnal pattern of TEC is characterized by a pre-sunrise (0400-0500 LT) minimum and near-noon (1300-1400 LT) maximum. Equatorial electrodynamics is dominated by the equatorial electrojet which in turn controls the daytime TEC variation and its maximum. We combine these long-term analyses to develop an empirical model of monthly mean TEC. The model is validated using both ETS-2 measurements and recent GNSS measurements. It is found that the present model efficiently estimates the TEC values within a 1-σ range from the observed mean values.

  14. An Analysis of the Role of Tobacco-Specific Nitrosamines in the Carcinogenicity of Tobacco Smoke

    OpenAIRE

    Brown, Buddy G.; Borschke, August J.; Doolittle, David J.

    2003-01-01

    Cigarette smoke is a complex mixture consisting of more than 4500 chemicals, including several tobacco-specific nitrosamines (TSNA). TSNA typically form in tobacco during the post-harvest period, with some fraction being transferred into mainstream smoke when a cigarette is burned during use. The most studied of the TSNA is 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). NNK has been shown to be carcinogenic in laboratory animals. Studies examining the carcinogenicity of NNK frequently ...

  15. Perturbation of Mitosis through Inhibition of Histone Acetyltransferases: The Key to Ochratoxin A Toxicity and Carcinogenicity?

    OpenAIRE

    Czakai, Kristin; Müller, Katja; Mosesso, Pasquale; Pepe, Gaetano; Schulze, Markus; Gohla, Antje; Patnaik, Debasis; Dekant, Wolfgang; Higgins, Jonathan M.G.; Mally, Angela

    2011-01-01

    Ochratoxin A (OTA) is one of the most potent rodent renal carcinogens studied to date. Although controversial results regarding OTA genotoxicity have been published, it is now widely accepted that OTA is not a mutagenic, DNA-reactive carcinogen. Instead, increasing evidence from both in vivo and in vitro studies suggests that OTA may promote genomic instability and tumorigenesis through interference with cell division. The aim of the present study was to provide further support for disruption...

  16. Carcinogenic effects of the combined action of /sup 241/Am and. gamma. -radiation

    Energy Technology Data Exchange (ETDEWEB)

    Filippova, L.G.; Buldakov, L.A.; Nifatov, A.P. (Institut Biofiziki, Moscow (USSR))

    In experiments on Wistar rats a study was made of the carcinogenic effects of the combined exposure to /sup 241/Am administered intrapertioneally (6.7 to 229.4 kBq/kg body weight) and external ..gamma..-radiation (/sup 137/Cs, 175 cGy). The occurrence of osteosarcoma, leucosis, skin and mammary tumors increased in the exposed animals. The combined irradiation produced an additive carcinogenic effect.

  17. A review of the genotoxic and carcinogenic effects of aspartame: does it safe or not?

    OpenAIRE

    Yılmaz, Serkan; Uçar, Aslı

    2014-01-01

    The objective of this article is to review genotoxicologic and carcinogenic profile of the artificial sweetener aspartame. Aspartame is a synthetic dipeptide, nearly 180–200 times sweeter than sucrose. It is the most widely used artificial sweetener especially in carbonated and powdered soft drinks, beverages, drugs and hygiene products. There is a discussion ongoing for many years whether aspartame posses genotoxic and carcinogenic risk for humans. This question led to many studies to specif...

  18. In vivo transgenic bioassays and assessment of the carcinogenic potential of pharmaceuticals.

    OpenAIRE

    Contrera, J F; DeGeorge, J J

    1998-01-01

    There is general agreement in the scientific community on the need to improve carcinogenicity testing and the assessment of human carcinogenic risk and to incorporate more information on mechanisms and modes of action into the risk assessment process. Advances in molecular biology have identified a growing number of genes such as protooncogenes and tumor-suppressor genes that are highly conserved across species and are associated with a wide variety of human and animal cancers. In vivo transg...

  19. Carcinogenic effects of the combined action of 241Am and γ-radiation

    International Nuclear Information System (INIS)

    In experiments on Wistar rats a study was made of the carcinogenic effects of the combined exposure to 241Am administered intrapertioneally (6.7 to 229.4 kBq/kg body weight) and external γ-radiation (137Cs, 175 cGy). The occurrence of osteosarcoma, leucosis, skin and mammary tumors increased in the exposed animals. The combined irradiation prodUced an additive carcinogenic effect

  20. Analysis of carcinogenicity testing for regulatory purposes in the European Union

    OpenAIRE

    MADIA FEDERICA; Worth, Andrew; Corvi, Raffaella

    2016-01-01

    The approaches for evaluating the carcinogenic potential of substances, including whether carcinogenicity studies should be conducted, differ substantially across sectors. Despite variations in testing schemes, the two-year bioassay study in rodents represents the standard element across all sectors. The validity of the two-year bioassay though has been questioned in the last decade. Uncertainty is associated with the extrapolation of data from rodents to humans. Furthermore, these stud...

  1. Carcinogens in Israeli milk: a study in regulatory failure.

    Science.gov (United States)

    Westin, J B

    1993-01-01

    The potential danger to humans of exposure to chemicals shown to be carcinogenic in animals has become increasingly clear in the last 20 years. A gap still exists, however, between the appreciation of the risk by scientists and the willingness of public health authorities to reduce it. Three pesticides, shown repeatedly to produce over a dozen different types of cancer in rats and mice, were discovered in inordinately high concentrations in Israeli milk and dairy products. The three pesticides--alpha-BHC, gamma-BHC (lindane), and DDT--had been shown to be present for ten years or more at mean concentrations up to 100 times those found in U.S. dairy products--with resultant concentrations in breast milk being possibly 800 times greater than those in the United States--yet neither the Ministry of Health nor the Israel Cancer Association made any apparent moves either to warn the public or to rectify the situation. A small consumer organization, Consumer Shield, brought the issue into the open. Through public pressure, court action, and the threat of further legal redress--and despite repeated attacks in the media by the milk producers, the Ministry, and the Cancer Association--Consumer Shield forced the authorities to outlaw the use of alpha-BHC and lindane (DDT no longer being in general use). The ban resulted in a precipitous drop in the concentrations of these substances in Israeli milk. Recent epidemiological and laboratory findings suggest that the dramatic drop in breast cancer mortality rates subsequent to the pesticide ban could be a direct result of that ban. PMID:8375952

  2. Gene discovery for the carcinogenic human liver fluke, Opisthorchis viverrini

    Directory of Open Access Journals (Sweden)

    Gasser Robin B

    2007-06-01

    Full Text Available Abstract Background Cholangiocarcinoma (CCA – cancer of the bile ducts – is associated with chronic infection with the liver fluke, Opisthorchis viverrini. Despite being the only eukaryote that is designated as a 'class I carcinogen' by the International Agency for Research on Cancer, little is known about its genome. Results Approximately 5,000 randomly selected cDNAs from the adult stage of O. viverrini were characterized and accounted for 1,932 contigs, representing ~14% of the entire transcriptome, and, presently, the largest sequence dataset for any species of liver fluke. Twenty percent of contigs were assigned GO classifications. Abundantly represented protein families included those involved in physiological functions that are essential to parasitism, such as anaerobic respiration, reproduction, detoxification, surface maintenance and feeding. GO assignments were well conserved in relation to other parasitic flukes, however, some categories were over-represented in O. viverrini, such as structural and motor proteins. An assessment of evolutionary relationships showed that O. viverrini was more similar to other parasitic (Clonorchis sinensis and Schistosoma japonicum than to free-living (Schmidtea mediterranea flatworms, and 105 sequences had close homologues in both parasitic species but not in S. mediterranea. A total of 164 O. viverrini contigs contained ORFs with signal sequences, many of which were platyhelminth-specific. Examples of convergent evolution between host and parasite secreted/membrane proteins were identified as were homologues of vaccine antigens from other helminths. Finally, ORFs representing secreted proteins with known roles in tumorigenesis were identified, and these might play roles in the pathogenesis of O. viverrini-induced CCA. Conclusion This gene discovery effort for O. viverrini should expedite molecular studies of cholangiocarcinogenesis and accelerate research focused on developing new interventions

  3. Effect of DNA type on response of DNA biosensor for carcinogens

    Science.gov (United States)

    Sani, Nor Diyana bt. Md.; Heng, Lee Yook; Surif, Salmijah; Lazim, Azwani Mat

    2013-11-01

    Carcinogens are cancer causing chemicals that can bind to DNA and cause damage to the DNA. These chemicals are available everywhere including in water, air, soil and food. Therefore, a sensor that can detect the presence of these chemicals will be a very useful tool. Since carcinogens bind to DNA, DNA can be used as the biological element in a biosensor. This study has utilized different types of DNA in a biosensor for carcinogen detection. The DNAs include double stranded calf thymus DNA, single stranded calf thymus DNA and guanine rich single stranded DNA. The modified SPE was exposed to a carcinogen followed by interaction with methylene blue which acts as the electroactive indicator. The SPE was then analysed using differential pulse voltammetry (DPV). Optimization studies were conducted for MB concentration and accumulation time, DNA concentration, as well as effect of buffer concentration, buffer pH and ionic strength. The performance of the biosensor was tested on a group 1 carcinogen, formaldehyde. The results indicated that the usage of guanine rich single stranded DNA also gives higher response as carcinogens prefer to bind with guanine compared to other bases.

  4. A comprehensive review of the carcinogenic and anticarcinogenic potential of capsaicin.

    Science.gov (United States)

    Bley, Keith; Boorman, Gary; Mohammad, Bashir; McKenzie, Donald; Babbar, Sunita

    2012-08-01

    Human exposure to capsaicin, the most abundant pungent chili pepper component, is ubiquitous. Evaluation of capsaicin's carcinogenic potential has produced variable results in in vitro and in vivo genotoxicity and carcinogenicity assays. The capsaicin tested in older studies was often from pepper plant extracts and included other capsaicinoids and diverse impurities. Recent studies utilizing high-purity capsaicin and standardized protocols provide evidence that the genotoxic and carcinogenic potential of capsaicin is quite low and that the purity of capsaicin is important. Several small epidemiological studies suggest a link between capsaicin consumption and stomach or gall bladder cancer, but contamination of capsaicin-containing foods with known carcinogens renders their interpretation problematic. The postulated ability of capsaicin metabolites to damage DNA and promote carcinogenesis remains unsupported. Anticancer activities of capsaicin have been widely reported, as it inhibits the activity of carcinogens and induces apoptosis in numerous cancer cell lines in vitro and explanted into rodents. Diverse mechanisms have been postulated for capsaicin's anticancer properties. One hypothesis is that inhibition of cytochrome P450 enzymes-particularly CYP2E1-retards carcinogen activation but is contradicted by the low potency of capsaicin for CYP inhibition. The potential for dietary capsaicin to act as a chemopreventative is now widely postulated. PMID:22563012

  5. Acupuncture at the San Jiao meridian affects brain stem issue G protein content in a rat migraine model

    Institute of Scientific and Technical Information of China (English)

    Sue Wang; Wei Li; Guangwei Zhong; Zhenyan Li; Lingbo Wen

    2008-01-01

    BACKGROUND: G protein is closely associated with vasomotion. Vasomotor dysfunction accompanies migraine attack. OBJECTIVE: To investigate the effects of the San Jiao meridian acupuncture on G protein content in a rat migraine model. DESIGN, TIME AND SETTING: The present randomized grouping, cellular and molecular biological level trial was performed at the Institute of Integrated Traditional Chinese and Western Medicine, Xiangya Hospital, Central South University & Key Laboratory for Tumor Proteomics of Ministry of Health between October 2003 and June 2004. MATERIALS: Forty healthy, male, Sprague Dawley rats were included in this study. The G6805-2A elector-acupuncture apparatus was a product of Shanghai Huayi Medical Instrument Factory, China. Nitroglycerin was produced by Guangzhou Mingxing Pharmaceutical Factory, China. Antibodies against inhibitory and stimulatory G proteins were purchased from Sigma Chemical Company, USA. METHODS: All 40 rats were randomly and evenly divided into 4 groups. In the blank control group, the rats remained untouched. Rats from the normal control group were subcutaneously administered 2 mL/kg physiological saline. In the model group, migraine was induced with a subcutaneous injection of 10 mg/kg nitroglycerin (5 g/L), and the rats received no further treatment. In the acupuncture-treated group, 30 minutes after migraine induction, acupuncture was performed at the bilateral Waiguan (SJ 5) and Yifeng (SJ 17) points, with an acupuncture depth of 1 mm. Electric-stimulation parameters of 20 Hz for low frequency, 40 Hz for high frequency, and 0.5-1.0 mA for current intensity were set. Ten acupuncture sessions were applied, with 20-minute low-frequency and 20-minute high-frequency stimulation and 3 seconds of interval time. MAIN OUTCOME MEASURES: Inhibitory and stimulatory G protein contents were detected by Western blot analysis. RESULTS: At 4 hours after migraine induction, compared with the blank control and normal control groups

  6. Ensemble kalman filtering to perform data assimilation with soil water content probes and pedotransfer functions in modeling water flow in variably saturated soils

    Science.gov (United States)

    Data from modern soil water contents probes can be used for data assimilation in soil water flow modeling, i.e. continual correction of the flow model performance based on observations. The ensemble Kalman filter appears to be an appropriate method for that. The method requires estimates of the unce...

  7. Modeling of soil water content and soil temperature at selected U.S. and central European stations using SoilClim model

    Science.gov (United States)

    Hlavinka, P.; Trnka, M.; Balek, J.; Zalud, Z.; Hayes, M.; Svoboda, M.; Eitzinger, J.

    2009-04-01

    Within the presented study the SoilClim model was tested through various climatic and soil conditions. SoilClim model enables to estimate reference and actual evapotranspiration from defined vegetation cover and consequently the soil water content within two defined layers (named as Moisture control section I and II) could be deduced. The soil temperature in 0.5 m depth is also estimated (on the basis of simple empirical model). Mentioned outputs could be additionally used for identification of soil climate regimes (both Hydric and Thermic) within selected location. The SoilClim works in daily step and needs daily maximum and minimum air temperature, global radiation, precipitation, air humidity and wind speed as input. The brief information about soil layers (field capacity, wilting point, depth) and vegetation cover is necessary. The algorithm for reference evapotranspiration is based on Penman-Monteith method. The main aim of the study was to assess accuracy and suitability of the SoilClim for simulation of soil water content in the two defined layers and temperature in 0.50 m depth. For this purpose the seven stations through central U.S. were selected (by twos from Nebraska, Iowa and Kansas and one from South Dakota). Used measurements were observed from 2004 to 2008. The central European region was represented by Austrian Lysimetric station Gross-Enzersdorf. The data within three different soil profiles and for various crop covers (spring barley, winter wheat, maize and potato) from 1999 to 2004 were used. During introduced reserch SoilClim provided reasonable results of soil moisture for both layers against lysimetric measurements. Agreement between measured and estimated water content (30 days averages) could be described by coefficient of determination (R2) which varied from 0.45 to 0.75. The Mean Bias Error (MBE) for values in daily step was from -12.87 % to 20.66 % and Root Mean Square Error (RMSE) varied from 14.49 % to 34.76 %. The modeling efficiency

  8. Evaluation of human health risks posed by carcinogenic and non-carcinogenic multiple contaminants associated with consumption of fish from Taihu Lake, China.

    Science.gov (United States)

    Yu, Yingxin; Wang, Xinxin; Yang, Dan; Lei, Bingli; Zhang, Xiaolan; Zhang, Xinyu

    2014-07-01

    The present study estimated the human daily intake and uptake of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), and toxic trace elements [mercury (Hg), chromium (Cr), cadmium (Cd), and arsenic (As)] due to consumption of fish from Taihu Lake, China, and the associated potential health risks posed by these contaminants. The health risks posed by the contaminants were assessed using a risk quotient of the fish consumption rate to the maximum allowable fish consumption rate considering the contaminants for carcinogenic and non-carcinogenic effect endpoints. The results showed that fish consumption would not pose non-cancer risks. However, some species would cause a cancer risk. Relative risks of the contaminants were calculated to investigate the contaminant which posed the highest risk to humans. As a result, in view of the contaminants for carcinogenic effects, As was the contaminant which posed the highest risk to humans. However, when non-carcinogenic effects of the contaminants were considered, Hg posed the highest risk. The risk caused by PBDEs was negligible. The results demonstrated that traditional contaminants, such as As, Hg, DDTs (dichlorodiphenyltrichloroethane and its metabolites), and PCBs, require more attention in Taihu Lake than the other target contaminants. PMID:24727049

  9. Use of the modified Ames test as an indicator of the carcinogenicity of residual aromatic extracts

    Energy Technology Data Exchange (ETDEWEB)

    Boogaard, P.; Hedelin, A.; Riley, A.; Rushton, E.; Vaissiere, M.; Minsavage, G.; Rohde, A.; Dalbey, W.

    2013-01-15

    Existing data demonstrate that residual aromatic extracts (RAEs) can be either carcinogenic or non-carcinogenic. CONCAWE had previously concluded that 'Although limited data available indicate that some RAEs are weakly carcinogenic, it is not possible to provide a general recommendation. Classify on a case-by-case basis' (CONCAWE 2005). Therefore CONCAWE's Health/Toxicology Subgroup (H/TSG) has developed a proposal for the use of the modified Ames test as a short-term predictive screening tool for decisions on the classification of RAEs for carcinogenicity. The relationship between RAE chemistry and carcinogenic potential is not as well understood as it is for some other categories of substances, e.g. Other Lubricant Base Oils (OLBO). However, a correlation has been found between the results of the skin carcinogenicity bioassay and the mutagenicity index (MI) obtained from the modified Ames test. Data supporting this correlation are summarised in this report. The H/TSG confirmed that the modified Ames test can be used as a predictive screening tool and that a cut-off value can be established to make a distinction between carcinogenic and non-carcinogenic products. RAEs with a MI > 0.4 demonstrated carcinogenic potential upon dermal application to mouse skin with chronic exposure. RAEs with a MI > 0.4 did not demonstrate a carcinogenic potential. To justify the use of the modified Ames test with RAEs, additional analysis of the repeatability of the test with RAEs was required. With this objective, CONCAWE sponsored a round robin study with different samples of RAEs from member companies, at three different laboratories. The repeatability demonstrated in the round robin study with RAEs support the proposed use of the modified Ames test. As part of the tools available for use by member companies, the H/TSG proposed a standard operating procedure (SOP) (included as an Appendix to this report) on the conduct of the modified Ames test with RAEs. The H

  10. Monitoring of the Liquid Water Content During Snowmelt Using C-Band SAR Data and the Snow Model CROCUS

    Science.gov (United States)

    Rondeau-Genesse, G.; Trudel, M.; Leconte, R.

    2014-12-01

    Coupling C-Band synthetic aperture radar (SAR) data to a multilayer snow model is a step in better understanding the temporal evolution of the radar backscattering coefficient during snowmelt. The watershed used for this study is the Nechako River Basin, located in the Rocky Mountains of British-Columbia (Canada). This basin has a snowpack of several meters in depth and part of its water is diverted to the Kemano hydropower system, managed by Rio-Tinto Alcan. Eighteen RADARSAT-2 ScanSAR Wide archive images were acquired in VV/VH polarization for the winter of 2011-2012, under different snow conditions. They are interpreted along with CROCUS, a multilayer physically-based snow model developed by Météo-France. This model discretizes the snowpack into 50 layers, which makes it possible to monitor various characteristics, such as liquid water content (LWC), throughout the season. CROCUS is used to model three specific locations of the Nechako River Basin. Results vary from one site to another, but in general there is a good agreement between the modeled LWC of the first layer of the snowpack and the backscattering coefficient of the RADARSAT-2 images, with a coefficient of determination (R²) of 0.80 and more. The radar images themselves were processed using an updated version of Nagler's methodology, which consists of subtracting an image in wet snow conditions to one in dry snow conditions, as wet snow can then be identified using a soft threshold centered around -3 dB. A second filter was used in order to differentiate dry snow and bare soil. That filter combines a VH/VV ratio threshold and an altitude criterion. The ensuing maps show a good agreement with the MODIS snow-covered area, which is already obtained daily over the Nechako River Basin, but with additional information on the location of wet snow and without sensibility to cloud cover. As a next step, the outputs of CROCUS will be used in Mätzler's Microwave Emission Model of Layered Snowpacks (MEMLS) to

  11. Molecular mechanism of metal-independent decomposition of organic hydroperoxides by halogenated quinoid carcinogens and the potential biological implications.

    Science.gov (United States)

    Huang, Chun-Hua; Ren, Fu-Rong; Shan, Guo-Qiang; Qin, Hao; Mao, Li; Zhu, Ben-Zhan

    2015-05-18

    Halogenated quinones (XQ) are a class of carcinogenic intermediates and newly identified chlorination disinfection byproducts in drinking water. Organic hydroperoxides (ROOH) can be produced both by free radical reactions and enzymatic oxidation of polyunsaturated fatty acids. ROOH have been shown to decompose to alkoxyl radicals via catalysis by transition metal ions, which may initiate lipid peroxidation or transform further to the reactive aldehydes. However, it is not clear whether XQ react with ROOH in a similar manner to generate alkoxyl radicals metal-independently. By complementary applications of ESR spin-trapping, HPLC/high resolution mass spectrometric and other analytical methods, we found that 2,5-dichloro-1,4-benzoquinone (DCBQ) could significantly enhance the decomposition of a model ROOH tert-butylhydroperoxide, resulting in the formation of t-butoxyl radicals independent of transition metals. On the basis of the above findings, we detected and identified, for the first time, an unprecedented C-centered quinone ketoxy radical. Then, we extended our study to the more physiologically relevant endogenous ROOH 13-hydroperoxy-9,11-octadecadienoic acid and found that DCBQ could also markedly enhance its decomposition to generate the reactive lipid alkyl radicals and the genotoxic 4-hydroxy-2-nonenal (HNE). Similar results were observed with other XQ. In summary, these findings demonstrated that XQ can facilitate ROOH decomposition to produce reactive alkoxyl, quinone ketoxy, lipid alkyl radicals, and genotoxic HNE via a novel metal-independent mechanism, which may explain partly their potential genotoxicity and carcinogenicity. PMID:25789984

  12. The potential effect of patulin on mice bearing melanoma cells: an anti-tumour or carcinogenic effect?

    Science.gov (United States)

    Boussabbeh, Manel; Ben Salem, Intidhar; Rjiba-Touati, Karima; Bouyahya, Chedy; Neffati, Fadwa; Najjar, Mohamed Fadhel; Bacha, Hassen; Abid-Essefi, Salwa

    2016-05-01

    Mycotoxins are bioactive compounds that are noxious to human. Their effects on oncogenesis have been satisfactorily elucidated, and some of mycotoxins have been classified as carcinogenic to humans. Nevertheless, patulin (PAT) is considered by the International Agency of Research on Cancer as 'not carcinogenic to humans'. The present study was designed to understand the effect of this mycotoxin on melanoma cells (B16F10) by measuring cell proliferation and assessing the anti-tumour effect in vivo in Balb/c mice. Our results revealed that intraperitoneally administration of PAT for 20 days significantly induces tumour regression in B16F10 cell-implanted mice. This effect was evidenced by the activation of apoptosis which is supported by the increase in p53 and Bax expressions, the downregulation of the protein levels of Bcl2, and the increase in caspase-3 activity. Moreover, systemic toxicity analysis demonstrated that there is no potential toxicity following PAT treatment unlike untreated melanoma mice which suffer from anaemia, inflammation and liver dysfunction. Remarkably, this is the first published report demonstrating the therapeutic efficacy of PAT in vivo models. PMID:26619846

  13. Joint leaf chlorophyll content and leaf area index retrieval from Landsat data using a regularized model inversion system (REGFLEC)

    KAUST Repository

    Houborg, Rasmus

    2015-03-01

    Leaf area index (LAI) and leaf chlorophyll content (Chll) represent key biophysical and biochemical controls on water, energy and carbon exchange processes in the terrestrial biosphere. In combination, LAI and Chll provide critical information on vegetation density, vitality and photosynthetic potentials. However, simultaneous retrieval of LAI and Chll from space observations is extremely challenging. Regularization strategies are required to increase the robustness and accuracy of retrieved properties and enable more reliable separation of soil, leaf and canopy parameters. To address these challenges, the REGularized canopy reFLECtance model (REGFLEC) inversion system was refined to incorporate enhanced techniques for exploiting ancillary LAI and temporal information derived from multiple satellite scenes. In this current analysis, REGFLEC is applied to a time-series of Landsat data.A novel aspect of the REGFLEC approach is the fact that no site-specific data are required to calibrate the model, which may be run in a largely automated fashion using information extracted entirely from image-based and other widely available datasets. Validation results, based upon in-situ LAI and Chll observations collected over maize and soybean fields in central Nebraska for the period 2001-2005, demonstrate Chll retrieval with a relative root-mean-square-deviation (RMSD) on the order of 19% (RMSD=8.42μgcm-2). While Chll retrievals were clearly influenced by the version of the leaf optical properties model used (PROSPECT), the application of spatio-temporal regularization constraints was shown to be critical for estimating Chll with sufficient accuracy. REGFLEC also reproduced the dynamics of in-situ measured LAI well (r2 =0.85), but estimates were biased low, particularly over maize (LAI was underestimated by ~36 %). This disparity may be attributed to differences between effective and true LAI caused by significant foliage clumping not being properly accounted for in the canopy

  14. The global morphology of the plasmaspheric electron content during Northern winter 2009 based on GPS/COSMIC observation and GSM TIP model results

    Science.gov (United States)

    Klimenko, M. V.; Klimenko, V. V.; Zakharenkova, I. E.; Cherniak, Iu. V.

    2015-04-01

    We studied the contribution of the global plasmaspheric and ionospheric electron content (PEC and IEC) into total electron content (TEC). The experimental PEC was estimated by comparison of GPS TEC observations and FORMOSAT-3/COSMIC radio occultation IEC measurements. Results are retrieved for the winter solstice (January and December 2009) conditions. Global maps of COSMIC-derived IEC, PEC and GPS TEC were compared with Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP) results. In addition, we used GSM TIP model results in order to estimate the contribution of plasmaspheric electron content into TEC value at the different altitudinal regions. The advantages and problems of the outer ionospheric/plasmaspheric parameters (O+/H+ transition height, TEC and electron density at height above F2 layer peak) representation by the IRI (International Reference Ionosphere) model are discussed.

  15. The effectiveness of chemical carcinogens to induce atherosclerosis in the white carneau pigeon

    International Nuclear Information System (INIS)

    The frequency of atherosclerotic lesions of the abdominal aorta has been reported to increase significantly in chickens exposed to benzo(a)pyrene and 7,12-dimethylbenz(a,h)anthracene. The present studies were performed to determine in another experimental model frequently used in atherosclerotic studies (i.e. White Carneau Pigeons) whether these and other chemical carcinogens enhance atherosclerosis. The induction and enhancement of atherosclerotic lesions were observed in pigeons treated with 7,12-dimethylbenz(a,h)anthracene, benzo(a)pyrene and 3-methylcholanthrene. The number and size of plaques in the aorta were frequently greater in pigeons treated with the higher concentrations (i.e. 100 mg/kg) of these 3 polycyclic aromatic hydrocarbons. Benzo(e)pyrene and 2,4,6-trichlorophenol were ineffective in the induction or enhancement of atherosclerosis in the pigeons. The results of the present and previous studies suggest that the polycyclic aromatic hydrocarbons (excluding benzo(e)pyrene) may be the only potential atherogens in avian atherosclerosis. This relationship may be associated with how these hydrocarbons are transported in the plasma (i.e. by lipoproteins) as demonstrated by the present distribution studies (author)

  16. An exact model for predicting tablet and blend content uniformity based on the theory of fluctuations in mixtures

    CERN Document Server

    Rane, Sagar S; Rieschl, Sarah

    2012-01-01

    The content uniformity (CU) of blend and tablet formulations is a critical property that needs to be well controlled in order to produce an acceptable pharmaceutical product. Methods that allow the formulations scientist to predict the CU accurately can greatly help in reducing the development efforts. This article presents a new statistical mechanical framework for predicting CU based on first principles at the molecular level. The tablet is modeled as an open system which can be treated as a grand canonical ensemble to calculate fluctuations in the number of granules and thus the CU. Exact analytical solutions to hard sphere mixture systems available in the literature are applied to derive an expression for the CU and elucidate the different factors that impact CU. It is shown that there is a single ratio, {\\lambda}{\\equiv}/; that completely characterizes "granule quality" with respect to impact on CU. Here w and f denote the weight of granule and the fractional (w/w) assay of API in it. This ratio should b...

  17. Effects of panaxadiol saponins on contents of TNF-α and IL-6 in two-hit rat models with hemorrhage and lipopolysaech

    International Nuclear Information System (INIS)

    Objective: To explore the changes of serum TNF-α and IL-6 contents in the two-hit rat models with hemorrhage and lipopolysaech (LPS) and the effects of panaxadiol saponins (PDS) on TNF-α and contents IL-6. Methods: Adult Wistar rats were randomly divided into 5 groups: sham operational group (S), hemorrhage group (H), two-hit group with hemorrhage and LPS groups (HL), Dexamethasone pretreatment group (HLD), PDS pretreatment group (HLP). The rat models were made by hemorrhagic shock as the first hit and with endotoxin as the second hit. Then the rats were killed after 6 h. The contents of serum TNF-α and IL-6 in rats were measured by radioimmunoassay. Results: The serum TNF-α and IL-6 contents in HL group were increased significantly compared with S group or H group (P<0.001). The TNF-α and IL-6 contents in HLP group and HLD group were significantly lower than those in HL group (P<0.01). Conclusion: LPS can increase significantly the contents of serum TNF-α and IL-6 in rats with hemorrhagic shock. PDS can inhibit the release of serum TNF-α and IL-6, and has the same effects with DEX to protect against the tissue injuries of two-hit rats with hemorrhage and LPS. (authors)

  18. Formulation of Japanese consensus-building model for HLW geological disposal site determination. 3. Development of digital contents on social consensus-buildings at educational institution

    International Nuclear Information System (INIS)

    To establish the sustainable community in Japan, formation of Japanese social consensus-building model for HLW geologic disposal site determination is one of key issues. In our project team of faculty of education, we found interesting middle school digital contents for HLW disposal site determination in London. We have been translating all of the digital contents for HLW disposal site determination into Japanese and we have been discussing on the model for next-generation Japanese consensus-building at middle school level. (author)

  19. The effect of soy hydrolysates on changes in cholesterol content and its oxidation products in fine - ground model sausages

    Directory of Open Access Journals (Sweden)

    Agnieszka Bilska

    2009-09-01

    Full Text Available Background. Meat products belong to products particularly at risk of fat oxidation processes. One of the methods to prevent disadvantageous oxidative changes of lipids in food is the application of antioxidants. Material and methods. The experimental material consisted of fine – ground model sausages. Produced processed meats differed in terms of the presence and amount of acid and enzymatic soy hydrolysates (0.3% and 0.7%. The reference sample comprised processed meat product with no hydrolysate added. Model processed meat products were stored at 4°C for 29 days. The analyses included changes in peroxide value, changes in cholesterol and its oxidation products. Results. It was found that changes of peroxide value, 7α-OHC, 7β-OHC, α-epoxy-C, β-epoxy-C, 20α-OHC, 25-OHC and total oxisterols were statistically significantly affected, apart from storage time, also by the type and level of applied hydrolysates. The addition of enzymatic and acid hydrolysates to batter of experimental sausages effectively inhibited the process of fat oxidation. Conclusions. In samples with enzymatic hydrolysate an approx. 20% loss of initial cholesterol content was recorded. In contrast, in the other samples this loss amounted to approx. 10%. The process of cholesterol metabolism in tested processed meat products was affected by their storage time and the type of added hydrolysate. It was observed that the highest dynamics of cholesterol metabolism occurred in a sample with no hydrolysate added. The level of total oxisterols in the sample with no addition of hydrolysate was over two times higher than in samples with an addition of hydrolysate.

  20. North American Magazine Coverage of Skin Cancer and Recreational Tanning Before and After the WHO/IARC 2009 Classification of Indoor Tanning Devices as Carcinogenic.

    Science.gov (United States)

    McWhirter, Jennifer E; Hoffman-Goetz, Laurie

    2015-09-01

    The mass media is an influential source of skin cancer information for the public. In 2009, the World Health Organization's International Agency for Research on Cancer classified UV radiation from tanning devices as carcinogenic. Our objective was to determine if media coverage of skin cancer and recreational tanning increased in volume or changed in nature after this classification. We conducted a directed content analysis on 29 North American popular magazines (2007-2012) to investigate the overall volume of articles on skin cancer and recreational tanning and, more specifically, the presence of skin cancer risk factors, UV behaviors, and early detection information in article text (n = 410) and images (n = 714). The volume of coverage on skin cancer and recreational tanning did not increase significantly after the 2009 classification of tanning beds as carcinogenic. Key-related messages, including that UV exposure is a risk factor for skin cancer and that indoor tanning should be avoided, were not reported more frequently after the classification, but the promotion of the tanned look as attractive was conveyed more often in images afterwards (p < .01). Content promoting high-SPF sunscreen use increased after the classification (p < .01), but there were no significant positive changes in the frequency of coverage of skin cancer risk factors, other UV behaviors, or early detection information over time. The classification of indoor tanning beds as carcinogenic had no significant impact on the volume or nature of skin cancer and recreational tanning coverage in magazines. PMID:25189799