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Sample records for bioconcentration factors bcfs

  1. Influence of nitrogen status on the bioconcentration of hydrophobic organic compounds to Selenastrum capricornutum

    DEFF Research Database (Denmark)

    Halling-Sørensen, B.; Nyholm, Niels; Kusk, Kresten Ole

    2000-01-01

    Changes in algal nitrogen status that increase algal lipid content also a€ect the bioconcentration of hydrophobic organic compounds (HOCs). Bioconcentration factors (BCFs) for several HOCs increased up to nine times as the total algal lipid content of the green algae Selenastrum carpricornutum in.......6, respectively, thus more than theoretically predicted from the lipid normalization of BCFs obtained at exponential growth phase (17% total lipid for S. carpricornutum), whereas BCFs for PCB 105, phenanthrene, and 4-chloroaniline increased at 44% lipid content, only by factors of 1.5, 1.5, and 2.5, respectively...

  2. A Bayesian approach to assessing the uncertainty in estimating bioconcentration factors in earthworms--the example of quinoxyfen.

    Science.gov (United States)

    Fragoulis, George; Merli, Annalisa; Reeves, Graham; Meregalli, Giovanna; Stenberg, Kristofer; Tanaka, Taku; Capri, Ettore

    2011-06-01

    Quinoxyfen is a fungicide of the phenoxyquinoline class used to control powdery mildew, Uncinula necator (Schw.) Burr. Owing to its high persistence and strong sorption in soil, it could represent a risk for soil organisms if they are exposed at ecologically relevant concentrations. The objective of this paper is to predict the bioconcentration factors (BCFs) of quinoxyfen in earthworms, selected as a representative soil organism, and to assess the uncertainty in the estimation of this parameter. Three fields in each of four vineyards in southern and northern Italy were sampled over two successive years. The measured BCFs varied over time, possibly owing to seasonal changes and the consequent changes in behaviour and ecology of earthworms. Quinoxyfen did not accumulate in soil, as the mean soil concentrations at the end of the 2 year monitoring period ranged from 9.16 to 16.0 µg kg⁻¹ dw for the Verona province and from 23.9 to 37.5 µg kg⁻¹ dw for the Taranto province, with up to eight applications per season. To assess the uncertainty of the BCF in earthworms, a probabilistic approach was used, firstly by building with weighted bootstrapping techniques a generic probabilistic density function (PDF) accounting for variability and incompleteness of knowledge. The generic PDF was then used to derive prior distribution functions, which, by application of Bayes' theorem, were updated with the new measurements and a posterior distribution was finally created. The study is a good example of probabilistic risk assessment. The means of mean and SD posterior estimates of log BCFworm (2.06, 0.91) are the 'best estimate values'. Further risk assessment of quinoxyfen and other phenoxyquinoline fungicides and realistic representative scenarios for modelling exercises required for future authorization and post-authorization requirements can now use this value as input. Copyright © 2011 Society of Chemical Industry.

  3. Predicting the bioconcentration factor of highly hydrophobic organic chemicals.

    Science.gov (United States)

    Garg, Rajni; Smith, Carr J

    2014-07-01

    Bioconcentration refers to the process of uptake and buildup of chemicals in living organisms. Experimental measurement of bioconcentration factor (BCF) is time-consuming and expensive, and is not feasible for a large number of chemicals of regulatory concern. Quantitative structure-activity relationship (QSAR) models are used for estimating BCF values to help in risk assessment of a chemical. This paper presents the results of a QSAR study conducted to address an important problem encountered in the prediction of the BCF of highly hydrophobic chemicals. A new QSAR model is derived using a dataset of diverse organic chemicals previously tested in a United States Environmental Protection Agency laboratory. It is noted that the linear relationship between the BCF and hydrophobic parameter, i.e., calculated octanol-water partition coefficient (ClogP), breaks down for highly hydrophobic chemicals. The parabolic QSAR equation, log BCF=3.036 ClogP-0.197 ClogP(2)-0.808 MgVol (n=28, r(2)=0.817, q(2)=0.761, s=0.558) (experimental log BCF range=0.44-5.29, ClogP range=3.16-11.27), suggests that a non-linear relationship between BCF and the hydrophobic parameter, along with inclusion of additional molecular size, weight and/or volume parameters, should be considered while developing a QSAR model for more reliable prediction of the BCF of highly hydrophobic chemicals. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Cummins, C.L.

    1994-09-01

    As a result of operations at the Savannah River Site (SRS), over 50 radionuclides have been released to the atmosphere and to onsite streams and seepage basins. Now, many of these radionuclides are available to aquatic and/or terrestrial organisms for uptake and cycling through the food chain. Knowledge about the uptake and cycling of these radionuclides is now crucial in evaluating waste management and clean-up alternatives for the site. Numerous studies have been conducted at the SRS over the past forty years to study the uptake and distribution of radionuclides in the Savannah River Site environment. In many instances, bioconcentration factors have been calculated to quantify the uptake of a radionuclide by an organism from the surrounding medium (i.e., soil or water). In the past, it has been common practice to use bioconcentration factors from the literature because site-specific data were not readily available. However, because of the variability of bioconcentration factors due to experimental or environmental conditions, site-specific data should be used when available. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at the Savannah River Site (SRS). An extensive literature search yielded site-specific bioconcentration factors for cesium, strontium, cobalt, plutonium, americium, curium, and tritium. These eight radionuclides have been the primary radionuclides studied at SRS because of their long half lives or because they are major contributors to radiological dose from exposure. For most radionuclides, it was determined that the site-specific bioconcentration factors were higher than those reported in literature. This report also summarizes some conditions that affect radionuclide bioavailability to and bioconcentration by aquatic and terrestrial organisms.

  5. Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River Site

    International Nuclear Information System (INIS)

    Cummins, C.L.

    1994-09-01

    As a result of operations at the Savannah River Site (SRS), over 50 radionuclides have been released to the atmosphere and to onsite streams and seepage basins. Now, many of these radionuclides are available to aquatic and/or terrestrial organisms for uptake and cycling through the food chain. Knowledge about the uptake and cycling of these radionuclides is now crucial in evaluating waste management and clean-up alternatives for the site. Numerous studies have been conducted at the SRS over the past forty years to study the uptake and distribution of radionuclides in the Savannah River Site environment. In many instances, bioconcentration factors have been calculated to quantify the uptake of a radionuclide by an organism from the surrounding medium (i.e., soil or water). In the past, it has been common practice to use bioconcentration factors from the literature because site-specific data were not readily available. However, because of the variability of bioconcentration factors due to experimental or environmental conditions, site-specific data should be used when available. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at the Savannah River Site (SRS). An extensive literature search yielded site-specific bioconcentration factors for cesium, strontium, cobalt, plutonium, americium, curium, and tritium. These eight radionuclides have been the primary radionuclides studied at SRS because of their long half lives or because they are major contributors to radiological dose from exposure. For most radionuclides, it was determined that the site-specific bioconcentration factors were higher than those reported in literature. This report also summarizes some conditions that affect radionuclide bioavailability to and bioconcentration by aquatic and terrestrial organisms

  6. Bioconcentration of Dissolved Organic Compounds from Oil Sands Process-Affected Water by Medaka (Oryzias latipes): Importance of Partitioning to Phospholipids.

    Science.gov (United States)

    Zhang, Kun; Wiseman, Steve; Giesy, John P; Martin, Jonathan W

    2016-06-21

    The complex mixture of dissolved organics in oil sands process-affected water (OSPW) is acutely lethal to fish at environmentally relevant concentrations, but few bioconcentration factors (BCFs) have been measured for its many chemical species. Japanese medaka (Oryzias latipes) were exposed to 10% OSPW, and measured BCFs were evaluated against predicted BCFs from octanol-water distribution ratios (DOW) and phospholipid membrane-water distribution ratios (DMW). Two heteroatomic chemical classes detected in positive ion mode (SO(+), NO(+)) and one in negative mode (O2(-), also known as naphthenic acids) had the greatest DMW values, as high as 10 000. Estimates of DMW were similar to and correlated with DOW for O(+), O2(+), SO(+), and NO(+) chemical species, but for O2(-) and SO2(-) species the DMW values were much greater than the corresponding DOW, suggesting the importance of electrostatic interactions for these ionizable organic acids. Only SO(+), NO(+), and O2(-) species were detectable in medaka exposed to OSPW, and BCFs for SO(+) and NO(+) species ranged from 0.6 to 28 L/kg, lower than predicted (i.e., 1.4-1.7 × 10(3) L/kg), possibly because of biotransformation of these hydrophobic substances. BCFs of O2(-) species ranged from 0.7 to 53 L/kg, similar to predicted values and indicating that phospholipid partitioning was an important bioconcentration mechanism.

  7. Resampling the bioconcentration factors data from Japan's chemical substances control law database to simulate and evaluate the bioconcentration factors derived from minimized aqueous exposure tests.

    Science.gov (United States)

    Hashizume, Naoki; Inoue, Yoshiyuki; Murakami, Hidekazu; Ozaki, Hiromichi; Tanabe, Aiko; Suzuki, Yasuyuki; Yoshida, Tomohiko; Kikushima, Erina; Tsuji, Toshiaki

    2013-02-01

    Existing standard bioconcentration tests (e.g., the Organization for Economic Cooperation and Development [OECD] test guideline 305) require large numbers of test animals and resources. The minimized aqueous exposure test is a new approach based on the standard bioconcentration test but allows estimation of bioconcentration factor (BCF) by minimized sampling of the test fish. The authors collected BCF data (298 curves from 155 chemicals, using common carp as test species) from Japan's Chemical Substances Control Law database and resampled the data to simulate the calculation of BCF that would be obtained if studies had been designed to obtain kinetic BCF derived from minimized aqueous exposure tests (BCF(km)). The correlation was high (r(2)  = 0.967) between BCF derived from standard bioconcentration tests (BCF(full)) and BCF(km). The average value of the BCF(full) to BCF(km) ratio (BCF(full):BCF(km)) was 1.04 and ranged from 0.54 to 1.93, the 5th and 95th percentiles being 0.74 and 1.45, respectively. The results based on the 5th and 95th percentiles of the BCF(full):BCF(km) ratio suggest that BCF(full) 2,000 corresponds to BCF(km) 1,400 to 2,700, whereas BCF(full) 5,000 corresponds to BCF(km) 3,400 to 6,800. The authors also emphasize that the standard bioconcentration test should be performed when the resulting BCF(km) is in the region of regulatory concern. Copyright © 2012 SETAC.

  8. Bioconcentration of atrazine and chlorophenols into roots and shoots of rice seedlings

    International Nuclear Information System (INIS)

    Su Yuhong; Zhu Yongguan

    2006-01-01

    Accumulation of o-chlorophenol (CP), 2,4-dichlorophenol (DCP), and atrazine (ATR), as single and mixed contaminants, from hydroponic solutions into roots and shoots of rice seedlings was studied following 48-h exposure of the plant roots. As single contaminants at low levels, the observed bioconcentration factors (BCFs) of CP and DCP with roots approximated the equilibrium values according to the partition-limited model. The BCF of atrazine with roots was about half the partition limit for unknown reasons. The BCFs of CP and ATR with shoots also approximated the partition limits, while the BCF for more lipophilic DCP with shoots was about half the estimated limit, due to insufficient water transport into plants for DCP. As mixed contaminants at low levels, the BCFs with both roots and shoots were comparable with those for the single contaminants; at high levels, the BCFs generally decreased because of the enhanced mixed-contaminant phytotoxicity, as manifested by the greatly reduced plant transpiration rate. - Uptakes of o-chlorophenol, 2,4-dichlorophenol, and atrazine at various levels from nutrient solution by roots and shoots of rice seedlings were investigated using a partition-limited model

  9. Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River site

    International Nuclear Information System (INIS)

    Friday, G.P.; Cummins, C.L.; Schwartzman, A.L.

    1996-01-01

    Since the early 1950s, the Savannah River Site (SRS) released over 50 radionuclides into the environment while producing nuclear defense materials. These releases directly exposed aquatic and terrestrial biota to ionizing radiation from surface water, soil, and sediment, and also indirectly by the ingestion of items in the food chain. As part of new missions to develop waste management strategies and identify cost-effective environmental restoration options, knowledge concerning the uptake and distribution of these radionuclides is essential. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at SRS

  10. Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River site

    Energy Technology Data Exchange (ETDEWEB)

    Friday, G.P.; Cummins, C.L.; Schwartzman, A.L.

    1996-12-31

    Since the early 1950s, the Savannah River Site (SRS) released over 50 radionuclides into the environment while producing nuclear defense materials. These releases directly exposed aquatic and terrestrial biota to ionizing radiation from surface water, soil, and sediment, and also indirectly by the ingestion of items in the food chain. As part of new missions to develop waste management strategies and identify cost-effective environmental restoration options, knowledge concerning the uptake and distribution of these radionuclides is essential. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at SRS.

  11. Partition coefficients of organic compounds in lipid-water systems and correlations with fish bioconcentration factors

    Science.gov (United States)

    Chiou, C.T.

    1985-01-01

    Triolein-water partition coefficients (KtW) have been determined for 38 slightly water-soluble organic compounds, and their magnitudes have been compared with the corresponding octanol-water partition coefficients (KOW). In the absence of major solvent-solute interaction effects in the organic solvent phase, the conventional treatment (based on Raoult's law) predicts sharply lower partition coefficients for most of the solutes in triolein because of its considerably higher molecular weight, whereas the Flory-Huggins treatment predicts higher partition coefficients with triolein. The data are in much better agreement with the Flory-Huggins model. As expected from the similarity in the partition coefficients, the water solubility (which was previously found to be the major determinant of the KOW) is also the major determinant for the Ktw. When the published BCF values (bioconcentration factors) of organic compounds in fish are based on the lipid content rather than on total mass, they are approximately equal to the Ktw, which suggests at least near equilibrium for solute partitioning between water and fish lipid. The close correlation between Ktw and Kow suggests that Kow is also a good predictor for lipid-water partition coefficients and bioconcentration factors.

  12. Bioconcentration factors and trace elements bioaccumulation in sporocarps of fungi collected from quartzite acidic soils.

    Science.gov (United States)

    Campos, Juan Antonio; Tejera, Noel Amaurys

    2011-10-01

    The content of 19 metals (Al, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Sr, Zr, Nb, Cs, Ba, Ce, Pb, Th, U and Nd) was investigated in 15 edible species of phylum Basidiomycota collected in an area with quartzite acidic soils in a province of the central Spain. The study explores the differences in metal accumulation in relation to fungal species, and the results were related to metal content in soil through the determination of bioconcentration factors. Regarding the highest concentrations, Zn, Al, Cu and Rb were the metals more accumulated in the sporocarps. Notable concentrations were also found in Sr, Zr, Ba, Cs and Ce. The major bioconcentration factors were found for Cu and Zn in sporocarps of Agaricus silvicola and Lepista nuda. Regarding the different species, Tricholoma equestre and Cantharellus cibarius were those with the greatest capacity to absorb trace elements, and in contrast, Amanita caesarea and Agaricus campestris showed the lowest values. The cluster analysis shows that there are some species with the same nutritive physiology that share similarities in the absorptive behaviour. Lactarius sanguifluus and Lactarius deliciosus, both ectomycorrhizas of the genus Pinus, are closely related, and Clitocybe gibba, L. nuda and Marasmius oreades, all of them saprobes on soil organic matter, are very close too.

  13. Uptake, depuration, and bioconcentration of two pharmaceuticals, roxithromycin and propranolol, in Daphnia magna.

    Science.gov (United States)

    Ding, Jiannan; Lu, Guanghua; Liu, Jianchao; Yang, Haohan; Li, Yi

    2016-04-01

    The objective of the present study was to investigate the uptake, depuration, and bioconcentration of two pharmaceuticals, roxithromycin (ROX) and propranolol (PRP), in Daphnia magna via aqueous exposure. Additionally, dietary and pH effects on the bioconcentration of two pharmaceuticals in daphnia were studied. During the 24-h uptake phase followed by the 24-h depuration phase, the uptake rate constants (k(u)) of ROX for daphnia were 9.21 and 2.77 L kg(-1) h(-1), corresponding to the exposure concentrations of 5 and 100 μg L(-1), respectively; For PRP at the nominal concentrations of 5 and 100 μg L(-1), k(u) were 2.29 and 0.99 L kg(-1) h(-1), respectively. The depuration rate constants (k(d)) of ROX in daphnia, at the exposure concentrations of 5 and 100 μg L(-1), were 0.0985 and 0.207 h(-1), respectively; while those of PRP were 0.0276 and 0.0539 h(-1) for the nominal concentrations of 5 and 100 μg L(-1), respectively. With the decreasing exposure concentrations, the bioconcentration factors (BCFs) in daphnia ranged from 13.4 to 93.5 L kg(-1) for ROX, and 18.4 to 83.0 L kg(-1) for PRP, revealing the considerable accumulation potential of these two pharmaceuticals. Moreover, after 6h exposure, the body burdens of ROX and PRP in dead daphnia were 4.98-6.14 and 7.42-12.9 times higher than those in living daphnia, respectively, implying that body surface sorption dominates the bioconcentration of the two pharmaceuticals in daphnia. In addition, the presence of algal food in the media could significantly elevate the kd values for both ROX and PRP, thereby restraining their bioconcentration in daphnia. A pH-dependent bioconcentration study revealed that the bioconcentration of the two pharmaceuticals in daphnia increased with increasing pH levels, which ranged from 7 to 9. Finally, a model was developed to estimate the relationships between pH and the BCFs of the two pharmaceuticals in zooplankton. The predicted values based on this model were highly consistent

  14. Apple snails and their endosymbionts bioconcentrate heavy metals and uranium from contaminated drinking water.

    Science.gov (United States)

    Vega, Israel A; Arribére, María A; Almonacid, Andrea V; Ribeiro Guevara, Sergio; Castro-Vazquez, Alfredo

    2012-09-01

    The differential ability of apple snail tissues, endosymbionts, and eggs to bioaccumulate several metals (Sb, As, Ba, Br, Zn, Cr, Fe, Hg, Se, and U) was investigated. Metal concentrations were determined by neutron activation analysis in several tissues, endosymbionts, and eggs from mature apple snails cultured in either drinking water or reconstituted water (prepared with American Society for Testing and Materials type I water). The highest bioconcentration factors (BCFs) in the midgut gland were found for Ba, Zn, Se, As, U, Br, and Hg (in decreasing order), while the highest in the kidney were for Ba, Br, and Hg. The foot showed the highest BCFs for Ba, Hg, Br, and Se (in decreasing order). Calcified tissues (uterus, shell) and eggs showed low BCFs, except for Ba. Both C corpuscles and gland tissue showed statistically higher BCFs than K corpuscles for Ba, Fe, U, Br, and Sb. The concentration of most of the studied elements was significantly lower in tissues and endosymbionts obtained from snails cultured in reconstituted water instead of drinking water. Snails cultured in reconstituted water and then exposed or not to Hg, As, and U (at the maximum contaminant level allowed by the US Environmental Protection Agency) also resulted in high levels accumulated in midgut gland, endosymbionts and kidney. Our findings suggest that the midgut gland (and the symbionts contained therein), the kidney, and the foot of Pomacea canaliculata may be useful bioindicators of Hg, As and U pollution in freshwater bodies and that the unrestricted use of ampullariid snails as human and animal food must be considered with caution.

  15. Mercury and its bioconcentration factors in King Bolete (Boletus edulis) Bull. Fr.

    Science.gov (United States)

    Falandysz, Jerzy; Frankowska, Aneta; Mazur, Aneta

    2007-12-01

    The total mercury content for a representative number of the carpophores of King Bolete from 13 sites across Poland averaged from 1.1 +/- 1.4 to 7.6 +/- 3.1 microg/g dry matter in the caps (total variation between 0.02 and 14 microg/g dm), and from 0.82 +/- 0.71 to 3.8 +/- 1.8 microg/g dm in stalks (total variation between 0.03 and 6.7 microg/g dm). A top soil layer (0-10 cm) collected from the mushroom sampling sites showed mean mercury content at range from 0.02 +/- 0.01 to 0.05 +/- 0.02 microg/g dm (total variation between 0.01 and 0.08 microg/g dm). King Bolete is effective mercury accumulator in the carpophores and bioconcentration factor (BCF) of this element in the caps ranged from 41 +/- 6 to 130 +/- 39 (total variation between 13 and 170) and in the stalks were from 27 +/- 18 to 72 +/- 22 (total variation between 4.0 and 90). Based on a relatively large set of data on the total mercury concentrations obtained in this survey, and dataset available for King Bolete from various sites in Europe, it seems reasonable to state that the upper food hygienic limit for the total mercury content in this species collected from unpolluted (background) sites should not exceed 20 microg/g dm in a single cap or a carpophore, while on an average, per site or consignment, should not exceed 10 mug/g dm in the caps or the carpophores.

  16. Membrane partitioning of ionic liquid cations, anions and ion pairs - Estimating the bioconcentration potential of organic ions.

    Science.gov (United States)

    Dołżonek, Joanna; Cho, Chul-Woong; Stepnowski, Piotr; Markiewicz, Marta; Thöming, Jorg; Stolte, Stefan

    2017-09-01

    Recent efforts have been directed towards better understanding the persistency and toxicity of ionic liquids (ILs) in the context of the "benign-by-design" approach, but the assessment of their bioaccumulation potential remains neglected. This paper reports the experimental membrane partitioning of IL cations (imidazolium, pyridinium, pyrrolidinium, phosphonium), anions ([C(CN) 3 ] - , [B(CN) 4 ] - , [FSO 2 ) 2 N] - , [(C 2 F 5 ) 3 PF 3 ] - , [(CF 3 SO 2 ) 2 N] - ) and their combinations as a measure for estimating the bioconcentration factor (BCF). Both cations and anions can have a strong affinity for phosphatidylcholine bilayers, which is mainly driven by the hydrophobicity of the ions. This affinity is often reflected in the ecotoxicological impact. Our data revealed that the bioconcentration potential of IL cations and anions is much higher than expected from octanol-water-partitioning based estimations that have recently been presented. For some ILs, the membrane-water partition coefficient reached levels corresponding to BCFs that might become relevant in terms of the "B" (bioaccumulation potential) classification under REACH. However, this preliminary estimation need to be confirmed by in vivo bioconcentration studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. The effects of dissolved organic matter and feeding on bioconcentration and oxidative stress of ethylhexyl dimethyl p-aminobenzoate (OD-PABA) to crucian carp (Carassius auratus).

    Science.gov (United States)

    Ma, Binni; Lu, Guanghua; Yang, Haohan; Liu, Jianchao; Yan, Zhenhua; Nkoom, Matthew

    2018-03-01

    Bioconcentration of UV filters in organisms is an important indicator for the assessment of environmental hazards. However, bioconcentration testing rarely accounts for the influence of natural aquatic environmental factors. In order to better assess the ecological risk of organic UV filters (OUV-Fs) in an actual water environment, this study determined the influences of dissolved organic matter (DOM) (0, 1, 10, and 20 mg/L) and feeding (0, 0.5, 1, and 2% body weight/d) on bioconcentration of ethylhexyl dimethyl p-aminobenzoate (OD-PABA) in various tissues of crucian carp (Carassius auratus). Moreover, oxidative stress in the fish liver caused by the OD-PABA was also investigated by measuring activities of superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST), and levels of glutathione (GSH) and malondialdehyde (MDA). The bioconcentration of OD-PABA in the fish tissues was significantly decreased with the presence of DOM indicating a reduction of OD-PABA bioavailability caused by DOM. The bioconcentration factors (BCFs) decreased by 28.00~50.93% in the muscle, 72.67~96.74% in the gill, 37.84~87.72% in the liver, and 10.32~79.38% in the kidney at different DOM concentrations compared to those of the non-DOM treatments. Significant changes in SOD, CAT, GST, GSH, and MDA levels were found in the DOM- and OD-PABA-alone treatments. However, there were no significant differences in the SOD, CAT, GST, and MDA levels found when co-exposure to OD-PABA and DOM. Feeding led to lower OD-PABA concentrations in the fish tissues, and the concentrations were decreased with increasing feeding ratios. BCFs in various tissues reduced by 39.75~72.52% in the muscle, 56.86~79.73% in the gill, 66.41~87.50% in the liver, and 75.88~89.10% in the kidney, respectively. In the unfed treatments, the levels of SOD and MDA were significantly higher than those of the fed ones while GST and GSH levels were remarkably inhibited indicating the enhanced effect of starvation

  18. The bioconcentration and bioaccumulation factors for molybdenum in the aquatic environment from natural environmental concentrations up to the toxicity boundary

    Energy Technology Data Exchange (ETDEWEB)

    Regoli, Lidia, E-mail: dagobert.heijerick@arche-consulting.be [IMOA, 4 Heathfield Terrace, Chiswick, London, W4 4JE (United Kingdom); Van Tilborg, Wim [VTBC Beekhuizenseweg 46, 6881Al Plaats, Velp (Netherlands); Heijerick, Dagobert [ARCHE Consulting, Stapelplein 70 box 104, 9000 Gent (Belgium); Stubblefield, William [Oregon State University, Department of Environmental and Molecular Toxicology, 421 Weniger Hall, Corvallis, OR 97331 (United States); Carey, Sandra [IMOA, 4 Heathfield Terrace, Chiswick, London, W4 4JE (United Kingdom)

    2012-10-01

    In a regulatory context, bioaccumulation or bioconcentration factors are used for considering secondary poisoning potential and assessing risks to human health via the food chain. In this paper, literature data on the bioaccumulation of molybdenum in the aquatic organisms are reviewed and assessed for relevance and reliability. The data available in the literature were generated at exposure concentrations below those recommended in the REACH registration dossiers for molybdenum compounds i.e. PNEC{sub freshwater} 12.7 mg Mo/L. To address possible environmental concerns at regulatorily-relevant molybdenum concentrations, both a field study and a laboratory study were conducted. In the field study, whole body and organ-specific molybdenum levels were evaluated in fish (eel, stickleback, perch, carp bream, roach) held in the discharge water collector tanks of a molybdenum processing plant, containing a mean measured molybdenum level of 1.03 mg Mo/L. In the laboratory study, rainbow trout were exposed to two different nominal molybdenum levels (1.0 and 12.7 mg Mo/L), for 60 days followed by a 60-day depuration period. Whole body concentrations in rainbow trout during the exposure period were between < 0.20 and 0.53 mg Mo/L. Muscle tissue molybdenum concentrations in fish taken from both experiments remained below 0.2 mg/kg dry wt. These studies show an inverse relationship between exposure concentration and bioconcentration or bioaccumulation factor for molybdenum. In aquatic organisms, and in fish in particular, internal molybdenum concentrations are maintained in the presence of variation in external molybdenum concentrations. These observations must be considered when evaluating potential risks associated with the bioconcentration and/or bioaccumulation of molybdenum in the aquatic environment. -- Highlights: Black-Right-Pointing-Pointer Addressing environmental concerns at regulatory-relevant molybdenum concentrations. Black-Right-Pointing-Pointer Inverse

  19. Bioconcentration of tetrachlorobenzene in marine algae

    Science.gov (United States)

    Wang, Xiu-Lin; Ma, Yan-Jun; Cheng, Gang; Yu, Wei-Jun; Zhang, Li-Jun

    1997-09-01

    Bioconcentration of tetrachlorobenzene (TeCB) in Chlorella marine, Nannochloropsis oculata, Pyramidomonas sp., Platymonas subcordiformis, and Phaeodactylum tricornutum; and toxicity of TeCB to the marine algae were tested. Values of bioconcentration potential parameters, including uptake rate constant k 1, elimination rate constant k 2 and bioconcentration factor BCF, were obtained not only from the time course of TeCB uptake by the marine algae by using a bioconcentration model, but also from the acute toxicity test data for percent inhibition PI(%)˜exposure concentration of TeCB-time by using a combined bioconcentration and probability model. The results showed good relationship between k 1(TOXIC) and k 1(UPTAKE) and k 2(TOXIC), k 2(UPTAKE), and BCF D(IOXIC) and BCF D(UPTAKE). Especially, the values of BCF D(TOXIC) were well consistent with those of BCF D(UPTAKE).

  20. Profile and bioconcentration of minerals by King Bolete (Boletus edulis) from the Płocka Dale in Poland.

    Science.gov (United States)

    Frankowska, Aneta; Ziółkowska, Joanna; Bielawski, Leszek; Falandysz, Jerzy

    2010-01-01

    This study aimed to provide basic data on the composition of metallic elements, including toxicologically important Cd and Hg, in popular and prized wild King Bolete mushrooms. We investigated the importance of soil substratum as a source of these metals. ICP-OES and CV-AAS were applied to determine the profile of Al, Ba, Ca, Cd, Cu, Fe, Hg, K, Mg, Mn, Na, Sr and Zn in caps and stipes of King Bolete mushroom and in the surface layer of soil (0-10 cm) from the Płocka Dale area of Poland. Hg, Cu, Cd, Zn, Mg and K exhibited bioconcentration factors (BCF) > 1. Specifically, Hg, Cu and Cd (mean BCFs for caps were 110, 19 and 16, respectively) were efficiently bioconcentrated by King Bolete, while other elements were bioexcluded (BCF < 1). Cadmium was present in the caps at mean levels of 5.5 ± 2.4 mg kg(-1) dry weight (dw) and mercury at levels of 4.9 ± 1.4 mg kg(-1) dw, both occurring at elevated concentrations in those King Bolete mushrooms surveyed.

  1. Using DTPA-extractable soil fraction to assess the bioconcentration factor of plants in phytoremediation of urban soils

    Science.gov (United States)

    Rodríguez-Bocanegra, Javier; Roca, Núria; Tume, Pedro; Bech, Jaume

    2017-04-01

    Urban soils may be highly contaminated with potentially toxic metals, as a result of intensive anthropogenic activities. Developing cities are increasing the number of lands where is practiced the urban agriculture. In this way, it is necessary to assess the part of heavy metals that is transferred to plants in order to a) know the potential health risk that represent soils and b) know the relation soil-plant to assess the ability of these plants to remove heavy metals from soil. Nowadays, to assess the bioconcentration factor (BF) of plants in phytoremediation, the pseudototal o total concentration has been used by many authors. Two different urban soils with similar pH and carbonates content but with different pollution degree were phytoremediated with different plant species. Urban soil from one Barcelona district (Spain), the most contaminated soil, showed an extractability of Cu, Pb and Zn of 9.6, 6.7 and 5.8% of the total fraction respectively. The soil from Talcahuano city (Chile), with contents of heavy metals slightly above the background upper limit, present values of 15.5, 13.5 and 12% of the total fraction of studied heavy metals. Furthermore, a peri-urban analysed soil from Azul (Argentina) also showed an elevated extractability with values of 24, 13.5 and 14% of the Cu, Pb and Zn contents respectively. These soils presented more extractability than other disturbed soils, like for example, soils from mine areas. The urban soils present more developed soil with an interaction between solution and solid phase in polluted systems. The most important soil surface functional groups include the basal plane of phyllosilicates and metal hydroxyls at edge sites of clay minerals, iron oxyhydroxides, manganese oxyhydroxides and organic matter. The interaction between solution and solid phase in polluted urban systems tends to form labile associations and pollutants are more readily mobilized because their bonds with soil particles are weaker. Clay and organic

  2. Cadmium in edible mushrooms from NW Spain: Bioconcentration factors and consumer health implications.

    Science.gov (United States)

    Melgar, M Julia; Alonso, Julián; García, M Angeles

    2016-02-01

    Mushrooms do not constitute a significant portion of the human diet, but the consumption of wild and cultivated mushrooms has become increasingly in recent years. Some species accumulate high levels of toxic metals, both in unpolluted and polluted areas. In this study, we examined the accumulation capacity of cadmium in edible mushrooms in relation to certain factors and their possible toxicological implications. Cadmium concentrations were determined by an ICP-MS spectrometer in 238 samples of the fruiting bodies of 28 wild and cultivated growing edible mushrooms species and the underlying soil. The hymenophore (H) and the rest of the fruiting body (RFB) were analysed separately. The highest mean cadmium concentration (mg/kg dry weight) was found in Agaricus macrosporus (52.9 in H and 28.3 in RFB). All mushroom species accumulated cadmium in relation to the underlying soils. There were statistically significant differences between the hymenophore and the rest of the fruiting body (p mushrooms is not a toxicological risk as far as cadmium content is concerned, although the species A. macrosporus should not be consumed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Evaluation and comparison of benchmark QSAR models to predict a relevant REACH endpoint: The bioconcentration factor (BCF)

    Energy Technology Data Exchange (ETDEWEB)

    Gissi, Andrea [Laboratory of Environmental Chemistry and Toxicology, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano (Italy); Dipartimento di Farmacia – Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, Via E. Orabona 4, 70125 Bari (Italy); Lombardo, Anna; Roncaglioni, Alessandra [Laboratory of Environmental Chemistry and Toxicology, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano (Italy); Gadaleta, Domenico [Laboratory of Environmental Chemistry and Toxicology, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano (Italy); Dipartimento di Farmacia – Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, Via E. Orabona 4, 70125 Bari (Italy); Mangiatordi, Giuseppe Felice; Nicolotti, Orazio [Dipartimento di Farmacia – Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, Via E. Orabona 4, 70125 Bari (Italy); Benfenati, Emilio, E-mail: emilio.benfenati@marionegri.it [Laboratory of Environmental Chemistry and Toxicology, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milano (Italy)

    2015-02-15

    The bioconcentration factor (BCF) is an important bioaccumulation hazard assessment metric in many regulatory contexts. Its assessment is required by the REACH regulation (Registration, Evaluation, Authorization and Restriction of Chemicals) and by CLP (Classification, Labeling and Packaging). We challenged nine well-known and widely used BCF QSAR models against 851 compounds stored in an ad-hoc created database. The goodness of the regression analysis was assessed by considering the determination coefficient (R{sup 2}) and the Root Mean Square Error (RMSE); Cooper's statistics and Matthew's Correlation Coefficient (MCC) were calculated for all the thresholds relevant for regulatory purposes (i.e. 100 L/kg for Chemical Safety Assessment; 500 L/kg for Classification and Labeling; 2000 and 5000 L/kg for Persistent, Bioaccumulative and Toxic (PBT) and very Persistent, very Bioaccumulative (vPvB) assessment) to assess the classification, with particular attention to the models' ability to control the occurrence of false negatives. As a first step, statistical analysis was performed for the predictions of the entire dataset; R{sup 2}>0.70 was obtained using CORAL, T.E.S.T. and EPISuite Arnot–Gobas models. As classifiers, ACD and log P-based equations were the best in terms of sensitivity, ranging from 0.75 to 0.94. External compound predictions were carried out for the models that had their own training sets. CORAL model returned the best performance (R{sup 2}{sub ext}=0.59), followed by the EPISuite Meylan model (R{sup 2}{sub ext}=0.58). The latter gave also the highest sensitivity on external compounds with values from 0.55 to 0.85, depending on the thresholds. Statistics were also compiled for compounds falling into the models Applicability Domain (AD), giving better performances. In this respect, VEGA CAESAR was the best model in terms of regression (R{sup 2}=0.94) and classification (average sensitivity>0.80). This model also showed the best

  4. Effects of water warming and acidification on bioconcentration, metabolization and depuration of pharmaceuticals and endocrine disrupting compounds in marine mussels (Mytilus galloprovincialis).

    Science.gov (United States)

    Serra-Compte, Albert; Maulvault, Ana Luisa; Camacho, Carolina; Álvarez-Muñoz, Diana; Barceló, Damià; Rodríguez-Mozaz, Sara; Marques, António

    2018-02-17

    Warming and acidification are expected impacts of climate change to the marine environment. Besides, organisms that live in coastal areas, such as bivalves, can also be exposed to anthropogenic pollutants like pharmaceuticals (PhACs) and endocrine disrupting compounds (EDCs). In this study, the effects of warming and acidification on the bioconcentration, metabolization and depuration of five PhACs (sotalol, sulfamethoxazole, venlafaxine, carbamazepine and citalopram) and two EDCs (methylparaben and triclosan) were investigated in the mussel species (Mytilus galloprovincialis), under controlled conditions. Mussels were exposed to warming and acidification, as well as to the mixture of contaminants up to 15.7 μg L -1 during 20 days; followed by 20 days of depuration. All contaminants bioconcentrated in mussels with levels ranging from 1.8 μg kg -1 dry weight (dw) for methylparaben to 12889.4 μg kg -1 dw for citalopram. Warming increased the bioconcentration factor (BCF) of sulfamethoxazole and sotalol, whereas acidification increased the BCF of sulfamethoxazole, sotalol and methylparaben. In contrast, acidification decreased triclosan levels, while both stressors decreased venlafaxine and citalopram BCFs. Warming and acidification facilitated the elimination of some of the tested compounds (i.e. sotalol from 50% in control to 60% and 68% of elimination in acidification and warming respectively). However, acidification decreased mussels' capacity to metabolize contaminants (i.e. venlafaxine). This work provides a first insight in the understanding of aquatic organisms' response to emerging contaminants pollution under warming and acidification scenarios. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Bioconcentration of polycyclic musks in fathead minnows caged in a wastewater effluent plume.

    Science.gov (United States)

    Lefebvre, Claudine; Kimpe, Linda E; Metcalfe, Chris D; Trudeau, Vance L; Blais, Jules M

    2017-12-01

    The synthetic polycyclic musks HHCB (Galaxolide ® ) and AHTN (Tonalide ® ) were monitored in fathead minnows (FHMs) caged for a month at various locations in the North Saskatchewan River (NSR), upstream and downstream of the Gold Bar wastewater treatment plant that serves the city of Edmonton, AB, Canada. In addition, the distribution of these musk compounds in the river was predicted using the fugacity-based Quantitative Water Air Sediment Interface (QWASI) model. In FHMs caged 0.15 km downstream of the wastewater outfall, mean concentrations of HHCB and AHTN were 7.4 and 0.4 μg g -1 wet weight, respectively. These are among the highest reported concentrations of these musk compounds in fish exposed to treated wastewater. The musk concentrations in FHMs were significantly lower further downstream of the outfall. High bioconcentration factors (BCFs) in FHMs that exceeded 10 4 higher than estimated concentrations in water indicated that there were low rates of biotransformation of the musks in the fish. In the FHMs caged at the site closest to the wastewater outfall, HHCB concentrations in FHMs were comparable to the body burdens that have been reported to moderate expression of vitellogenin in female rainbow trout, indicating that fish in the NSR downstream of the wastewater outfall may be at risk of anti-estrogenic effects. The QWASI model applied to six individual river sections of the NSR predicted that the largest fluxes of HHCB and AHTN would be for downstream transport in water, which explains why FHMs accumulated elevated concentrations of the musks at the furthest downstream site, 9.9 km from the wastewater discharge. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Element composition of biota, water and sediment in the Forsmark area, Baltic Sea. Concentrations, bioconcentration factors and partitioning coefficients (K{sub d}) of 48 elements

    Energy Technology Data Exchange (ETDEWEB)

    Kumblad, Linda; Bradshaw, Clare (Dept. of Systems Ecology, Stockholm Univ. (Sweden))

    2008-08-15

    In this study the elemental composition of biota, water and sediment from a shallow bay in the Forsmark region have been determined. The report presents data for 48 different elements (Al, As, Ba, Br, C, Ca, Cd, Ce, Cl, Co, Cr, Cs, Cu, Dy, Er, Eu, F, Fe, Gd, Hg, Ho, I, K, Li, Lu, Mg, Mn, N, Na, Nd, Ni, P, Pb, Pr, Ra, Rb, S, Se, Si, Sm, Tb, Th, Ti, Tm, V, Yb, Zn, Zr) in all major functional groups of the coastal ecosystem (phytoplankton, zooplankton, benthic microalgae, macroalgae, macrophytes, benthic herbivores, benthic filter feeders, benthic detrivores, planktivorous fish, benthic omnivorous fish, carnivorous fish, dissolved and particulate matter in the water and the sediment) during spring 2005. The overall aim of the study is to contribute to a better understanding of ecological properties and processes that govern uptake and transfer of trace elements, heavy-metals, radionuclides and other non-essential elements/contaminants in coastal environments of the Baltic Sea. In addition, the data was collected to provide site-specific Bioconcentration Factors (BCF), Biomagnification Factors (BMF), partitioning coefficients (K{sub d}) and element ratios (relative to carbon) for use in ongoing SKB safety assessments. All these values, as well as the element concentration data from which they are derived, are presented here. As such, this is mainly a data report, although initial interpretations of the data also are presented and discussed. Reported data include element concentrations, CNP-stoichiometry, and multivariate data analysis. Elemental concentrations varied greatly between organisms and environmental components, depending on the function of the elements, and the habitat, ecosystem function, trophic level and morphology (taxonomy) of the organisms. The results show for instance that food intake and metabolism strongly influence the elemental composition of organisms. The three macrophytes had quite similar elemental composition (despite their taxonomic

  7. Element composition of biota, water and sediment in the Forsmark area, Baltic Sea. Concentrations, bioconcentration factors and partitioning coefficients (Kd) of 48 elements

    International Nuclear Information System (INIS)

    Kumblad, Linda; Bradshaw, Clare

    2008-08-01

    In this study the elemental composition of biota, water and sediment from a shallow bay in the Forsmark region have been determined. The report presents data for 48 different elements (Al, As, Ba, Br, C, Ca, Cd, Ce, Cl, Co, Cr, Cs, Cu, Dy, Er, Eu, F, Fe, Gd, Hg, Ho, I, K, Li, Lu, Mg, Mn, N, Na, Nd, Ni, P, Pb, Pr, Ra, Rb, S, Se, Si, Sm, Tb, Th, Ti, Tm, V, Yb, Zn, Zr) in all major functional groups of the coastal ecosystem (phytoplankton, zooplankton, benthic microalgae, macroalgae, macrophytes, benthic herbivores, benthic filter feeders, benthic detrivores, planktivorous fish, benthic omnivorous fish, carnivorous fish, dissolved and particulate matter in the water and the sediment) during spring 2005. The overall aim of the study is to contribute to a better understanding of ecological properties and processes that govern uptake and transfer of trace elements, heavy-metals, radionuclides and other non-essential elements/contaminants in coastal environments of the Baltic Sea. In addition, the data was collected to provide site-specific Bioconcentration Factors (BCF), Biomagnification Factors (BMF), partitioning coefficients (K d ) and element ratios (relative to carbon) for use in ongoing SKB safety assessments. All these values, as well as the element concentration data from which they are derived, are presented here. As such, this is mainly a data report, although initial interpretations of the data also are presented and discussed. Reported data include element concentrations, CNP-stoichiometry, and multivariate data analysis. Elemental concentrations varied greatly between organisms and environmental components, depending on the function of the elements, and the habitat, ecosystem function, trophic level and morphology (taxonomy) of the organisms. The results show for instance that food intake and metabolism strongly influence the elemental composition of organisms. The three macrophytes had quite similar elemental composition (despite their taxonomic differences

  8. Biotransformation and bioconcentration of pyrene in Daphnia magna

    International Nuclear Information System (INIS)

    Akkanen, Jarkko; Kukkonen, Jussi V.K.

    2003-01-01

    Water fleas (Daphnia magna) were exposed to [ 14 C]pyrene in the presence and absence of piperonyl butoxide (PBO), a general cytochrome P450 (CYP) inhibitor, in organic carbon-free artificial freshwater (AFW, DOC -1 ) and in natural lake water (DOC=19.9 mg l -1 ) for 24 h. The bioconcentration of total radioactivity after 24 h exposure was 50% lower in the natural lake water, indicating decreased bioavailability of pyrene by the dissolved organic matter. However, the proportions of parent compound were only ca. 12 and 19% of the total body burden in daphnids exposed in AFW and natural lake water, respectively. Therefore, the tissue concentration of the parent pyrene was not significantly different in the daphnids exposed in the two different waters. Due to extensive biotransformation the bioconcentration factor (BCF) of parent pyrene was only 16 and 23% of the BCF calculated on the basis of total radioactivity in the daphnids in AFW and natural lake water, respectively. The proportion of parent pyrene was significantly higher (over 60%) in the daphnids exposed simultaneously to PBO, which indicates the involvement of CYP monooxygenases in the biotransformation. Furthermore, increasing PBO concentration decreased the accumulation of total radioactivity in AFW but not in the natural lake water. The data demonstrate capability and importance of CYP monooxygenases in biotransformation of polycyclic aromatic hydrocarbons in D. magna

  9. Experimental assessment of the bioconcentration of (15)N-tamoxifen in Pseudokirchneriella subcapitata.

    Science.gov (United States)

    Orias, Frédéric; Simon, Laurent; Perrodin, Yves

    2015-03-01

    Nowadays, pharmaceutical compounds (PC) are ubiquitous in aquatic ecosystems. In addition to direct ecotoxicity, the bioconcentration of PC in organisms is a phenomenon which could have an impact on the whole ecosystem. In order to study this phenomenon, we exposed unicellular algae (Pseudokirchneriella subcapitata) to (15)N-tamoxifen, an anticancer drug labelled with a stable nitrogen isotope used as a tracer. By measuring (15)N enrichment over time, we were able to measure the increase of tamoxifen content in algae. This enrichment was measured by an elemental analyser coupled with an isotopic ratio mass spectrometer (EA-IRMS). Algal cells were exposed for 7d to 3 concentrations of tamoxifen: 1, 10 and 100μgL(-1). Our result shows a high bioconcentration in algae from the first minutes of contact. The highest bioconcentration factor measured is around 26500. We also observe that bioconcentration is not linked to the exposure concentration. This study is the first to use stable isotopes in order to monitor PCs in aquatic organisms such as algae. The use of stable isotopes in ecotoxicology offers interesting perspectives in the field of contaminant transfer in organisms and along the trophic web. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Bioconcentration and endocrine disruption effects of diazepam in channel catfish, Ictalurus punctatus.

    Science.gov (United States)

    Overturf, C L; Overturf, M D; Huggett, D B

    2016-01-01

    Recently, the detection of pharmaceuticals in surface waters has increased worldwide. Pharmaceuticals are typically found in the environment at concentrations well below therapeutic levels in humans; however, their mechanisms of action may be largely unknown in non-target organisms, such as teleost species. Thus, chronic exposure to these types of compounds warrants further investigation. The goal of this study was to examine the potential for diazepam, a model benzodiazepine drug, to bioconcentrate in tissues of channel catfish and to examine its ability to interact with the endocrine system through modulation of steroid hormones and/or steroidogenic genes. To investigate the bioconcentration potential of diazepam, channel catfish (Ictalurus punctatus) were exposed to 1 ng/mL diazepam for seven days, followed by clean water for another seven days, using an abbreviated OECD 305 Fish Bioconcentration Test study design. This concentration of diazepam is well below environmentally relevant concentrations of diazepam (ng/L). To evaluate steroidogenic effects, fish were exposed to 1 ng/mL diazepam for seven days only. Steroid hormone concentrations were analyzed for various tissues, as well as expression of selected steroidogenic genes. Calculated bioconcentration factors for diazepam were well below regulatory threshold values in all tissues analyzed. No changes in steroid hormone concentration were detected in any tissue analyzed; however, the steroidogenic gene cytochrome P450 side chain cleavage (P450scc) was significantly down-regulated at day 5 and 3β-hydroxy steroid dehydrogenase (3β-HSD) was significantly down-regulated at day 7 in the gonad. These results indicate that although diazepam does not significantly bioconcentrate, low-level chronic exposure to diazepam may have the potential to interact with endocrine function by altering gene expression. Copyright © 2016. Published by Elsevier Inc.

  11. Comparison of bioconcentration of ionic silver and silver nanoparticles in zebrafish eleutheroembryos.

    Science.gov (United States)

    López-Serrano, A; Muñoz-Olivas, R; Sanz-Landaluze, J; Olasagasti, M; Rainieri, S; Cámara, C

    2014-08-01

    The production of silver nanoparticles has reached nowadays high levels. Bioconcentration studies, information on persistence and toxicity are fundamental to assess their global risk and thus necessary to establish legislations regarding their use. Previous studies on silver nanoparticle toxicity have determined a clear correlation between their chemical stability and toxicity. In this work, experimental conditions able to assure silver nanoparticles stability have been optimized. Then, zebrafish (Danio rerio) eleutheroembryos were exposed to ionic silver and to Ag NPs for comparison purposes. A protocol alternative to the OECD 305 technical guideline was used. To determine silver concentration in both the eleutheroembryos and the exposure media, an analytical method consisting in ultrasound assisted extraction, followed by inductively coupled plasma mass spectrometry and graphite furnace atomic absorption spectrometry, was developed. Then, bioconcentration factors were calculated. The results revealed that ionic silver was more accumulative for zebrafish eleutheroembryos than nanoparticles at the levels tested. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Bioconcentration and localization of lead in the freshwater rotifer Brachionus calyciflorus Pallas 1677 (Rotifera: Monogononta)

    International Nuclear Information System (INIS)

    Alvarado-Flores, Jesús; Rico-Martínez, Roberto; Ventura-Juárez, Javier; Silva-Briano, Marcelo; Rubio-Franchini, Isidoro

    2012-01-01

    We studied how lead is bioconcentrated and distributed in the rotifer Brachionus calyciflorus using metal histochemistry to locate lead granules, Leadmium Green ® analysis to establish the route of uptake, atomic absorption to determined the bioconcentration factor (BCF), and detected the presence of microelements in the cuticle by X-ray microanalysis with scanning electron microscopy. Our results indicate: (a) the digestive system is the main route of lead uptake in the rotifer B. calyciflorus, (b) after 24-h lead is deposited in granules in the mastax and vitellarium, (c) our energy-dispersive X-ray microanalysis indicates decalcification taking place in the cuticle of the rotifer after a 24-h lead exposure, and (d) we determined a BCF = 115 for lead after a 24 h exposure. However, the route of mobilization and storage of intracellular lead are still not fully understood in B. calyciflorus.

  13. Bioconcentration and localization of lead in the freshwater rotifer Brachionus calyciflorus Pallas 1677 (Rotifera: Monogononta)

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado-Flores, Jesus, E-mail: jalvaflo@hotmail.com [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Quimica, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Rico-Martinez, Roberto, E-mail: rrico@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Quimica, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Ventura-Juarez, Javier, E-mail: jventur@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Morfologia, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Silva-Briano, Marcelo, E-mail: msilva@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Biologia, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Rubio-Franchini, Isidoro, E-mail: rubio_reyes@hotmail.com [Instituto de Servicios de Salud del Estado de Aguascalientes, Laboratorio Estatal de Salud Publica, Av. Siglo XXI 105, Ciudad Satelite Morelos, C.P. 20270, Aguascalientes, Ags. (Mexico)

    2012-03-15

    We studied how lead is bioconcentrated and distributed in the rotifer Brachionus calyciflorus using metal histochemistry to locate lead granules, Leadmium Green{sup Registered-Sign} analysis to establish the route of uptake, atomic absorption to determined the bioconcentration factor (BCF), and detected the presence of microelements in the cuticle by X-ray microanalysis with scanning electron microscopy. Our results indicate: (a) the digestive system is the main route of lead uptake in the rotifer B. calyciflorus, (b) after 24-h lead is deposited in granules in the mastax and vitellarium, (c) our energy-dispersive X-ray microanalysis indicates decalcification taking place in the cuticle of the rotifer after a 24-h lead exposure, and (d) we determined a BCF = 115 for lead after a 24 h exposure. However, the route of mobilization and storage of intracellular lead are still not fully understood in B. calyciflorus.

  14. Integration of QSAR models for bioconcentration suitable for REACH

    Energy Technology Data Exchange (ETDEWEB)

    Gissi, Andrea [Laboratory of Chemistry and Environmental Toxicology, IRCCS - Istituto di Ricerche Farmacologiche “Mario Negri”, via Giuseppe La Masa 19, 20156 Milan (Italy); Dipartimento di Farmacia — Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, I-70125 Bari (Italy); Nicolotti, Orazio; Carotti, Angelo; Gadaleta, Domenico [Dipartimento di Farmacia — Scienze del Farmaco, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, I-70125 Bari (Italy); Lombardo, Anna [Laboratory of Chemistry and Environmental Toxicology, IRCCS - Istituto di Ricerche Farmacologiche “Mario Negri”, via Giuseppe La Masa 19, 20156 Milan (Italy); Benfenati, Emilio, E-mail: benfenati@marionegri.it [Laboratory of Chemistry and Environmental Toxicology, IRCCS - Istituto di Ricerche Farmacologiche “Mario Negri”, via Giuseppe La Masa 19, 20156 Milan (Italy)

    2013-07-01

    QSAR (Quantitative Structure Activity Relationship) models can be a valuable alternative method to replace or reduce animal test required by REACH. In particular, some endpoints such as bioconcentration factor (BCF) are easier to predict and many useful models have been already developed. In this paper we describe how to integrate two popular BCF models to obtain more reliable predictions. In particular, the herein presented integrated model relies on the predictions of two among the most used BCF models (CAESAR and Meylan), together with the Applicability Domain Index (ADI) provided by the software VEGA. Using a set of simple rules, the integrated model selects the most reliable and conservative predictions and discards possible outliers. In this way, for the prediction of the 851 compounds included in the ANTARES BCF dataset, the integrated model discloses a R{sup 2} (coefficient of determination) of 0.80, a RMSE (Root Mean Square Error) of 0.61 log units and a sensitivity of 76%, with a considerable improvement in respect to the CAESAR (R{sup 2} = 0.63; RMSE = 0.84 log units; sensitivity 55%) and Meylan (R{sup 2} = 0.66; RMSE = 0.77 log units; sensitivity 65%) without discarding too many predictions (118 out of 851). Importantly, considering solely the compounds within the new integrated ADI, the R{sup 2} increased to 0.92, and the sensitivity to 85%, with a RMSE of 0.44 log units. Finally, the use of properly set safety thresholds applied for monitoring the so called “suspicious” compounds, which are those chemicals predicted in proximity of the border normally accepted to discern non-bioaccumulative from bioaccumulative substances, permitted to obtain an integrated model with sensitivity equal to 100%. - Highlights: • Applying two independent QSAR models for bioconcentration factor increases the prediction. • The concordance of the models is an important component of the integration. • The measurement of the applicability domain improves the

  15. Toxic effects, bioconcentration and depuration of verapamil in the early life stages of common carp (Cyprinus carpio L.)

    Czech Academy of Sciences Publication Activity Database

    Steinbach, C.; Fedorova, G.; Prokeš, Miroslav; Grabicová, K.; Máchová, J.; Grabic, R.; Valentová, O.; Kocour Kroupová, H.

    461-462, 461-462 (2013), s. 198-206 ISSN 0048-9697 Institutional support: RVO:68081766 Keywords : Bioconcentration * Embryo-larval test * Half-life time * Heart rate * Verapamil Subject RIV: GL - Fishing Impact factor: 3.163, year: 2013

  16. Bioconcentration, Metabolism and Excretion of Triclocarban in larval Qurt Medaka (Oryzias latipes)

    Science.gov (United States)

    Schebb, Nils Helge; Flores, Ida; Kurobe, Tomofumi; Franze, Bastian; Ranganathan, Anupama; Hammock, Bruce D.; Teh, Swee

    2011-01-01

    The antimicrobial triclocarban (TCC) is frequently found in personal care products and commonly observed in surface waters and sediments. Due to its long environmental persistence TCC accumulates in sewage sludge. It also shows a high unintended biological activity as a potent inhibitor of the soluble epoxide hydrolase (sEH) and may be an endocrine disruptor. In this study, we investigated bioconcentration, metabolism and elimination of TCC in fish using Medaka (Oryzias latipes) as a model. Medaka larvae (7±1 days post hatching) were exposed to 63 nM (20 µg/L) TCC water for 24 hours. The LC-MS/MS analysis of water and tissues provided bioconcentration of TCC and its metabolites in fish body and rapid excretion into culture water. Results from tissue samples showed a tissue concentration of 34 µmol/kg and a log bioconcentration factor (BCF) of 2.86. These results are slightly lower than previous findings in snails and algae. A significant portion of the absorbed TCC was oxidatively metabolized by the fish to hydroxylated products. These metabolites underwent extensive phase II metabolism to yield sulfate and glucuronic acid conjugates. The most abundant metabolite in fish tissue was the glucuronide of 2’-OH-TCC. Elimination of TCC after transferring the fish to fresh water was rapid, with a half-life of 1 hour. This study shows that larval medaka metabolize TCC similarly to mammals. The rapid rate of metabolism results in a lower bioconcentration than calculated from the n-octanol/water partition coefficient of TCC. PMID:21872556

  17. Estimation of herbicide bioconcentration in sugarcane (Saccharum officinarum L.

    Directory of Open Access Journals (Sweden)

    Antonio Luiz Cerdeira

    2015-04-01

    Full Text Available Sugarcane is an important crop for sugar and biofuel production in Brazil. Growers depend greatly on herbicides to produce it. This experiment used herbicide physical-chemical and sugarcane plant physiological properties to simulate herbicide uptake and estimate the bioconcentration factor (BCF. The (BCF was calculated for the steady state chemical equilibrium between the plant herbicide concentration and soil solution. Plant-water partition coefficient (sugarcane bagasse-water partition coefficient, herbicide dilution rate, metabolism and dissipation in the soil-plant system, as well as total plant biomass factors were used. In addition, we added Tebuthiuron at rate of 5.0kg a.i. ha-1 to physically test the model. In conclusion, the model showed the following ranking of herbicide uptake: sulfentrazone > picloram >tebuthiuron > hexazinone > metribuzin > simazine > ametryn > diuron > clomazone > acetochlor. Furthermore, the highest BCF herbicides showed higher Groundwater Ubiquity Score (GUS index indicating high leaching potential. We did not find tebuthiuron in plants after three months of herbicide application

  18. Bioconcentration of (15)N-tamoxifen at environmental concentration in liver, gonad and muscle of Danio rerio.

    Science.gov (United States)

    Orias, Frédéric; Simon, Laurent; Mialdea, Gladys; Clair, Angéline; Brosselin, Vanessa; Perrodin, Yves

    2015-10-01

    Pharmaceutical compounds (PCs) are ubiquitous in aquatic ecosystems. In addition to the direct ecotoxicological risk presented by certain PCs, others can accumulate inside organisms and along trophic webs, subsequently contaminating whole ecosystems. We studied the bioconcentration of a bioaccumulative PC already found several times in the environment: tamoxifen. To this end, we exposed Danio rerio for 21d to (15)N-tamoxifen concentrations ranging from 0.1 to 10µg/L and used an analytic method based on stable isotopes to evaluate the tamoxifen content in these organisms. The evolution of the (15)N/(14)N ratio was thus measured in liver, muscle and gonads of exposed fish compared to control fish. We succeeded in quantifying (15)N-tamoxifen bioconcentrations at all the exposure concentrations tested. The highest bioconcentration factors of tamoxifen measured were 14,920 in muscle, 73,800 in liver and 85,600 in gonads of fish after 21d exposure at a nominal concentration of 10µg/L. However, these bioconcentration factors have to be considered as maximal values (BCFMAX). Indeed, despite its proven stability, tamoxifen can be potentially partially degraded during experiments. We now need to refine these results by using a direct analytic method (i.e. LC-MS/MS). Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Bioconcentration of Water Soluble Fraction (WSF) of crude oil in ...

    African Journals Online (AJOL)

    Bioconcentration of water soluble fraction of Australian crude oil in 50 fingerlings of Oreochromis niloticus was conducted under laboratory conditions for 28 days. An initial acute toxicity test was carried out using different concentrations (25ml/L, 50ml/L, 75ml/L, 100ml/L and a control) of the water soluble fraction (WSF) of ...

  20. Freshwater clams as bioconcentrators of avian influenza virus in water.

    Science.gov (United States)

    Huyvaert, Kathryn P; Carlson, Jenny S; Bentler, Kevin T; Cobble, Kacy R; Nolte, Dale L; Franklin, Alan B

    2012-10-01

    We report experimental evidence for bioconcentration of a low-pathogenicity avian influenza virus (H6N8) in the tissue of freshwater clams. Our results support the concept that freshwater clams may provide an effective tool for use in the early detection of influenza A viruses in aquatic environments.

  1. Heavy metal sensitivity and bioconcentration in oribatid mites (Acari, Oribatida)

    Energy Technology Data Exchange (ETDEWEB)

    Skubala, Piotr, E-mail: piotr.skubala@us.edu.pl [Department of Ecology, University of Silesia, Bankowa 9, 40-007 Katowice (Poland); Zaleski, Tomasz [Department of Soil Science and Soil Protection, Agricultural University in Krakow, Mickiewicza 21, 31-120 Cracow (Poland)

    2012-01-01

    In this study we aimed to identify different reactions of oribatid species to heavy metal pollution and to measure concentrations of cadmium, zinc and copper in oribatid species sampled along a gradient. Oribatid mites were sampled seasonally during two years in five meadows located at different distances from the zinc smelter in the Olkusz District, southern Poland. Oribatids were shown to withstand critical metal concentration and established comparatively abundant and diverse communities. The highest abundance and species richness of oribatids were recorded in soils with moderate concentrations of heavy metals. Four different responses of oribatid species to heavy metal pollution were recognized. Heavy metals (Zn, Pb, Cd, Ni) and various physical (bulk density, field capacity, total porosity) and chemical (K{sub av}, P{sub av}, N, C, pH) factors were recognized as the structuring forces that influence the distribution of oribatid species. Analysis by atomic absorption spectrophotometry revealed large differences in metal body burdens among species. None of the species can be categorized as accumulators or non-accumulators of the heavy metals - the pattern depends on the metal. The process of bioconcentration of the toxic metal (regulated) and essential elements (accumulated) was generally different in the five oribatid species studied. - Highlights: Black-Right-Pointing-Pointer Responses of oribatid mites to metal contamination along a gradient in meadow soils were studied. Black-Right-Pointing-Pointer Small concentrations of heavy metals positively influenced the abundance of oribatid mites. Black-Right-Pointing-Pointer Four different responses of oribatid species to heavy metal pollution were recognised. Black-Right-Pointing-Pointer Bioaccumulation of the toxic metal and essential elements proceeded differently in oribatid species. Black-Right-Pointing-Pointer Five studied oribatid species were deconcentrators of cadmium.

  2. Heavy metal sensitivity and bioconcentration in oribatid mites (Acari, Oribatida)

    International Nuclear Information System (INIS)

    Skubała, Piotr; Zaleski, Tomasz

    2012-01-01

    In this study we aimed to identify different reactions of oribatid species to heavy metal pollution and to measure concentrations of cadmium, zinc and copper in oribatid species sampled along a gradient. Oribatid mites were sampled seasonally during two years in five meadows located at different distances from the zinc smelter in the Olkusz District, southern Poland. Oribatids were shown to withstand critical metal concentration and established comparatively abundant and diverse communities. The highest abundance and species richness of oribatids were recorded in soils with moderate concentrations of heavy metals. Four different responses of oribatid species to heavy metal pollution were recognized. Heavy metals (Zn, Pb, Cd, Ni) and various physical (bulk density, field capacity, total porosity) and chemical (K av , P av , N, C, pH) factors were recognized as the structuring forces that influence the distribution of oribatid species. Analysis by atomic absorption spectrophotometry revealed large differences in metal body burdens among species. None of the species can be categorized as accumulators or non-accumulators of the heavy metals — the pattern depends on the metal. The process of bioconcentration of the toxic metal (regulated) and essential elements (accumulated) was generally different in the five oribatid species studied. - Highlights: ► Responses of oribatid mites to metal contamination along a gradient in meadow soils were studied. ► Small concentrations of heavy metals positively influenced the abundance of oribatid mites. ► Four different responses of oribatid species to heavy metal pollution were recognised. ► Bioaccumulation of the toxic metal and essential elements proceeded differently in oribatid species. ► Five studied oribatid species were deconcentrators of cadmium.

  3. Toxicity and Bioconcentration of Cadmium and Copper in Artemia Urmiana Nauplii

    Directory of Open Access Journals (Sweden)

    Mohammad Mohiseni

    2017-01-01

    Full Text Available Background: Artemia urmiana are small crustaceans that because of its non-selective filter feeder pattern potentially may absorb high level of heavy metals through their living environment. In this study, the effects of different levels of cadmium and copper on survival, catalase activity and metals bioconcentration rates in A. urmiana nauplii have been investigated. Methods: The research was carried out in February 2012 at University of Tehran, Tehran, Iran. First experiment was conducted in nine concentrations with six replication, then LC50 and probable interactions between experimental metals were evaluated. In the second experiment, concentrations of metals absorbed by Artemia and catalase activity were measured based on the acute toxicity indices, including NOEC, LOEC and LC50 at individual and mixed concentrations. Results: The toxicity of copper sulphate (LC50= 29.87 was 2.5 times greater than cadmium chloride (LC50=79.08 and the toxicity interaction between cadmium and copper was synergistic. The rate of copper uptake in Artemia was higher than cadmium and increased concentration of heavy metals significantly decreased the bioconcentration factor. Comparison of mixed and individual concentrations showed that cadmium significantly decreased copper uptake, while it seems that cadmium bioconcentration was improved consequently. Biochemical analysis showed that the catalase activity was affected undesirably in different individual and mixed concentrations; however, these changes were not significant. Conclusion: A. urmiana nauplia seems to be highly resistant toward cadmium and copper in their culture medium and demonstrated excessive potential for uptake of heavy metals from their rearing environment.

  4. Biotransformation and Bioconcentration of Steroid Estrogens by Chlorella vulgaris

    OpenAIRE

    Lai, K. M.; Scrimshaw, M. D.; Lester, J. N.

    2002-01-01

    The biotransformation and bioconcentration of natural and synthetic steroid estrogens by Chlorella vulgaris were investigated by using batch-shaking experiments with incubation for 48 h in the light or dark. Estradiol and estrone were interconvertible in both light and dark conditions; however, this biotransformation showed a preference for estrone. In the light, 50% estradiol was further metabolized to an unknown product. Apart from biotransformation, estrone, as well as hydroxyestrone, estr...

  5. A flow-through passive dosing system for continuously supplying aqueous solutions of hydrophobic chemicals to bioconcentration and aquatic toxicity tests

    DEFF Research Database (Denmark)

    Adolfsson-Erici, Margaretha; Åkerman, Gun; Jahnke, Annika

    2012-01-01

    A continuous supply of water with defined stable concentrations of hydrophobic chemicals is a requirement in a range of laboratory tests such as the OECD 305 protocol for determining the bioconcentration factor in fish. Satisfying this requirement continues to be a challenge, particularly for hyd...

  6. Acute toxicity and bioconcentration of fungicide tebuconazole in zebrafish (Danio rerio).

    Science.gov (United States)

    Andreu-Sánchez, Oscar; Paraíba, Lourival C; Jonsson, Claudio M; Carrasco, José M

    2012-02-01

    This research work investigated the bioconcentration of tebuconazole [(±)-α-[2-(4-chlorophenyl)ethyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol] fungicide in zebrafish (Danio rerio) under laboratory conditions and a first-order kinetic pesticide dissipation in the water. The concentrations of tebuconazole fitted to an equivalent nonlinear kinetic type model which allowed the calculation of the following parameters: bioconcentration factor (38.80 L kg(-1) ), time to reach maximum fish concentration (6 days), maximum concentration in fish (0.0075 μg mg(-1) ), half-life in fish (24 days) and time needed for the fish to eliminate 95% of the maximum concentration (105 days). These calculations permitted the establishment of theoretical reference limit values for human consumption of fish and the establishment of safe limits for the water pesticide concentration. The data would also be useful in safe strategies associated with fishery activities that are conducted in aquatic regions close to crops using tebuconazole. The information will contribute to enlarge the tebuconazole toxicokinetics database of aquatic organisms. Copyright © 2011 Wiley Periodicals, Inc.

  7. Bioconcentration of trace metals by Saccostrea cucullata (von Born 1778) from Andaman waters

    Digital Repository Service at National Institute of Oceanography (India)

    Abhilash, K.R.; Gireeshkumar, T.R.; Venu, S.; Raveendran, T.V.

    content was represented as µgg-1 of sample on a wet weight basis. Sediment and water samples collected from these stations were also analysed for trace metals using standard procedures15,16. Thereafter, the bioconcentration factor (BCF), i... in seawater (in µg/ml wet weight with SD); n=3 replicates Zn Cu Fe Pb Ni North Bay 1.09±0.06 2.76±0.77 0.40±0.18 2.84±0.74 0.08±0.01 Aberdeen Jetty 1.02±0.19 3.55±0.60 0.12±0.02 4.65±0.30 0.12±0.12 Fisheries Jetty 2.67±0.47 13.01±0.69 0.46±0.10 4...

  8. Biotransformation and Bioconcentration of Steroid Estrogens by Chlorella vulgaris

    Science.gov (United States)

    Lai, K. M.; Scrimshaw, M. D.; Lester, J. N.

    2002-01-01

    The biotransformation and bioconcentration of natural and synthetic steroid estrogens by Chlorella vulgaris were investigated by using batch-shaking experiments with incubation for 48 h in the light or dark. Estradiol and estrone were interconvertible in both light and dark conditions; however, this biotransformation showed a preference for estrone. In the light, 50% estradiol was further metabolized to an unknown product. Apart from biotransformation, estrone, as well as hydroxyestrone, estriol, and ethinylestradiol, was relatively stable in the algal culture, whereas estradiol valerate was hydrolyzed to estradiol and then to estrone within 3 h of incubation. All of the tested estrogens exhibited a degree of partitioning to C. vulgaris; however, the concentrations of estriol, hydroxyestrone, ethinylestradiol, and estradiol valerate were always below the quantification limits. For estradiol and estrone, the partitioning of these estrogens in the algal extracts to the filtrates was biotransformation. PMID:11823229

  9. Influence of ortho-substitution homolog group on polychlorobiphenyl bioaccumulation factors and fugacity ratios in plankton and zebra mussels (Dreissena polymorpha)

    Energy Technology Data Exchange (ETDEWEB)

    Willman, E.J.; Manchester-Neesvig, J.B.; Agrell, C.; Armstrong, D.E.

    1999-07-01

    The accumulation of a set of non- and mono-ortho (coplanar) PCB congeners in aquatic ecosystems is of interest due to their dioxin-like toxicities. Chemical properties (octanol-water partition coefficients) suggest that the coplanar congeners may accumulate in organisms to a greater extent than homologs with greater ortho substitution. The authors analyzed a set of 65 PCB congeners with zero to four ortho-chlorines from seven homolog groups in water, suspended particulate matter, and zebra mussels from Green Bay, Wisconsin, USA, on four dates throughout the ice-free season. The suspended particulate matter was separated by size and characterized as phytoplankton or zooplankton using diagnostic carotenoid pigments and light microscopy. Median bioconcentration factors (BCFs) for accumulation from water by phytoplankton and bioaccumulation factors (BAFs) for accumulation from water plus food by zooplankton and zebra mussels ranged from 1 x 10{sup 4} to 1 x 10{sup 6} and were generally the greatest for the tetra- to heptachlorobiphenyls. The average coplanar congener BCFs and BAFs for accumulation from water by phytoplankton, zooplankton, and zebra mussels for the tri-, tetra-, and pentachlorobiphenyls were 54% larger than corresponding values for their homologs. Biomagnification factors (BMFs) of the tetra-, penta-, and hexachlorobiphenyls between zooplankton and zebra mussels and their food source, phytoplankton, typically ranged between 1 and 10, but the average coplanar congener BMFs were 25% less than values for their corresponding homologs. The tendency for coplanar congeners to accumulate to a lesser extent between trophic levels was not as large as their tendency to accumulate from water to a greater extent. Based on accumulation factors, the authors conclude that the dioxin-like tetra- and pentachlorobiphenyls generally accumulate in the phytoplankton, zooplankton, and zebra mussels of the Green Bay ecosystem to a greater extent than other congeners. Fugacity

  10. The effect of pH on the bioconcentration and toxicity of weak organic electrolytes

    DEFF Research Database (Denmark)

    Rendal, Cecilie

    an extensive literature search, and based on this dataset, the toxicity and bioconcentration of electrolytes was found to be systematically higher at pH levels that favor the neutral species. In surface waters with pH levels between 6 and 9 the bioconcentration and toxicity of acids and bases can thus...... in this thesis, and on the discussion thereof. The regular use of these guidelines will help eliminate situations where bioconcentration or toxicity is underestimated. The guidelines are supported by simple and robust test methods for conducting pH specific toxicity tests with the common test organisms Daphnia...

  11. Toxicity and bioconcentration evaluation of RDX and HMX using sheepshead minnows in water exposures.

    Science.gov (United States)

    Lotufo, Guilherme R; Gibson, Alfreda B; Yoo, J Leslie

    2010-10-01

    Lethal effects of the explosives RDX and HMX were assessed using ten-day water exposures to juvenile sheepshead minnows (Cyprinodon variegatus). For RDX, maximum mortality occurred during the first two days of exposure with a 10-d median lethal concentration (LC50) of 9.9 mg L(-1). The RDX 10-d median lethal residue (LR50) was 9.6 mg kg(-1) (34.9 μmol kg(-1)) wet weight (ww), the first RDX critical body residue reported for fish. Previous investigations reported that RDX body residues in marine amphipods up to 96 μmol kg(-1) ww and in marine mussels up to 86 μmol kg(-1) ww failed to result in significant mortality. The highest HMX concentration tested, corresponding to its apparent solubility limit in seawater (2.0 mg L(-1)), and the associated mean body residue (3 mg kg(-1) or 14 μmol kg(-1) ww) resulted in no significant mortality for exposed minnows. The mean 10-d bioconcentration factors for RDX (0.6-0.9 L kg(-1)) and HMX (0.3-1.6 L kg(-1)) were typically lower than 1, reflecting the low bioaccumulative potential for these compounds. Published by Elsevier Inc.

  12. Toxic effects, bioconcentration and depuration of verapamil in the early life stages of common carp (Cyprinus carpio L.)

    Energy Technology Data Exchange (ETDEWEB)

    Steinbach, Christoph, E-mail: steinbach@frov.jcu.cz [Research Institute of Fish Culture and Hydrobiology, South Bohemian Research Centre of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia in Ceske Budejovice, CZ-38925 Vodnany (Czech Republic); Fedorova, Ganna [Research Institute of Fish Culture and Hydrobiology, South Bohemian Research Centre of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia in Ceske Budejovice, CZ-38925 Vodnany (Czech Republic); Prokes, Miroslav [Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, v.v.i., Kvetna 8, 603 65 Brno (Czech Republic); Grabicova, Katerina; Machova, Jana; Grabic, Roman; Valentova, Olga; Kroupova, Hana Kocour [Research Institute of Fish Culture and Hydrobiology, South Bohemian Research Centre of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia in Ceske Budejovice, CZ-38925 Vodnany (Czech Republic)

    2013-09-01

    Verapamil is a pharmaceutical that belongs to a group of calcium channel blockers and is mainly used as a treatment of angina pectoris and arterial hypertension. Verapamil has been detected in aquatic environments in concentrations ranging from ng L{sup −1} to μg L{sup −1}. In the present study, a series of acute toxicity tests of verapamil on various developmental stages of common carp (Cyprinus carpio) were conducted. As a result, 96hLC{sub 50} values of verapamil were estimated at 16.4 ± 9.2, 7.3 ± 1.5 and 4.8 ± 0.2 mg L{sup −1} for embryos (E5–E9) and common carp larvae L2 and L5, respectively. Lethal concentrations of verapamil decreased with an increase in the age of the fish. Acute exposure to verapamil significantly reduced the heart rate in the embryos and larvae. In an embryo-larval toxicity test (sub-chronic exposure), the bioconcentration, depuration, and toxic effects of verapamil were assessed in common carp. The fish were exposed to verapamil in a concentration of 0.463 (environmentally relevant), 4.63, 46.3 and 463 μg L{sup −1}. Verapamil had no effect on the accumulated mortality, hatching, condition factor, growth or ontogeny of the fish in any of the tested concentrations. In carp exposed to 463 and 46.3 μg L{sup −1} of verapamil, significantly higher occurrences of malformations and edemas were observed compared to the control. The bioconcentration factor of verapamil in whole fish homogenates ranged between 6.6 and 16.6 and was therefore below the critical value for hazard substances (BCF > 500). The half-life and the 95% depuration time for the tested compound were estimated to be 10.2 ± 1.6 days and 44.2 ± 8.6 days, respectively. No effects of verapamil on the studied endpoints were observed at environmentally relevant concentrations. - Highlights: • Study of the acute and sub-chronic toxicity of verapamil on early-life stages of common carp. • Acute exposure to verapamil reduced the heart rate in early-life stages of

  13. A review of measured bioaccumulation data in terrestrial plants for organic chemicals: Metrics, variability and the need for standardized measurement protocols

    DEFF Research Database (Denmark)

    Doucette, William J; Shunthirasingham, Chubashini; Dettenmaier, Erik M

    2018-01-01

    by plants are often expressed as ratios of chemical concentrations in the plant compartments of interest (e.g., leaves, shoots, roots, xylem sap) to that in the exposure medium (e.g., soil, soil pore water, hydroponic solution, air). These ratios are generally referred to as bioconcentration factors (BCFs...

  14. Bioconcentration of trace metals in the tissues of two leafy vegetables widely consumed in South West Nigeria.

    Science.gov (United States)

    Tyokumbur, Emmanuel Teryila; Okorie, Tonye

    2011-05-01

    The trace metal levels in the tissues of two popular leafy vegetables Amaranthus caudatus and Corchrus olithorus widely consumed in Nigeria were assessed from a cultivated floodplain receiving effluents from diverse factories in Ibadan. Although the leaves are primarily consumed, the stems are usually used as a feed for farm animals while the roots are disposed by burning when dry or by composting. The objective of this work was to evaluate the level of trace elements in the tissues of these vegetables at harvest time when they become available to the human ecosystem for exposure to the accumulated trace metals, especially the leaves which are cooked and eaten as soup. The results of the mean trace metal levels in the analyses show that the leaves of A. caudatus had the highest bioconcentration in the following order Ba>Mn>Zn>Cu>Pb>Cr>Co>Ni>Cd>U>Sb, stems: Ba>Zn>Mn>Cu>Cr>Pb>Ni>Co>Cd>U>Sb, and roots: Mn>Ba>Zn>Cu>Cr>Pb>Ni>Co>U>Cd>Sb. In C. olithorus, the order was Mn>Ba>Zn>Cu>Pb>Cr>Co>Ni>Cd>Sb>U in the leaves, Mn>Zn>Ba>Pb>Cr>Cu>Co>Ni>U>Cd>Sb in the roots, and Mn>Zn>Ba>Cu>Cr>Pb>Co>Ni>Cd>U>Sb in the stems. The final result of the vegetable samples showed that the trace metal concentration was in the range of Cr (0.8-58.7), Mn (35.0-9,495.9), Co (0.3-33.6), Cu (2.3-60.3), Zn (16.0-538.2), Cd (0.000-40.53), Sb (0.000-0.037), Ba (13.0-1,175.6), Pb (0.9-39.7), and U (0.0-2.2). The bioconcentration factors (BF) for the transfer of trace metals from soil to the tissues showed a higher ease of bioaccumulation when compared to previous studies. The element with the highest BF in the study was Ba (6.45) in the leaves while the least was Co (0.09) in the roots of A. caudatus. The level of bioconcentration of trace metals in the leaves in most of the samples exceeds the recommended levels given by the World Health Organization (WHO) and Federal Environmental Protection Agency (FEPA), Nigeria and therefore constitutes a potential public health risk to the populace who consume

  15. Bioconcentration of Heavy Metals in high Density traffic area of Port ...

    African Journals Online (AJOL)

    This shows that aerial deposition or diffusion of these Heavy Metals from automobile exhaust and adsorption processes to the grasses along HDTA plays a major role in their Bioconcentration. The order of BCF of Heavy Metals in grasses along HDTA (Cr > Cd = Co > Ni > Zn > Pb > Fe) and LDTA (Cr > Cd > Ni > Pb > Co ...

  16. Bioconcentration, biotransformation and elimination of pyrene in the arctic crustacean Gammarus setosus (Amphipoda) at two temperatures.

    Science.gov (United States)

    Carrasco-Navarro, V; Jæger, I; Honkanen, J O; Kukkonen, J V K; Carroll, JoLynn; Camus, Lionel

    2015-09-01

    The influence of temperature on the bioaccumulation, toxicokinetics, biotransformation and depuration of pyrene was studied in the arctic marine amphipod Gammarus setosus. A two-compartment model was used to fit experimental values of total body burden, total metabolites and parent pyrene concentrations and to calculate toxicokinetic variables derived for two experimental treatments (2 and 8 °C). No statistically significant differences were observed with temperature for these toxicokinetic variables or bioconcentration factors. Contrarily, the Q10 values suggested that the toxicokinetic variables ke and km were temperature-dependent. This may be explained by the high standard deviation of the Q10 values. Q10 is the variation in the rate of a metabolic reaction with a 10 °C increase in temperature. Depuration rate constants were calculated from linear best fit equations applied to measured pyrene concentrations over time during the depuration phase of the experiment. During depuration, the parent pyrene was eliminated in two stages with faster elimination observed at 8 °C compared to 2 °C. This finding was also indicated by the Q10. No changes in total body burdens of metabolite concentrations were observed during the monitoring of depuration over a period of 96 h. The biotransformation pathway of pyrene in G. setosus was also investigated in this study with two main phase II biotransformation products discovered by liquid chromatography. These products are conditionally identified as the sulphate and glucose conjugates of 1-hydroxy-pyrene. Overall, the study contributes new knowledge to the understanding of the fate of PAHs in arctic biota. In particular, the study provides valuable insight into the bioaccumulation and biotransformation of an important PAH and its metabolites in a species that serves as both a predator and prey in the arctic ecosystem. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Bioconcentration of polycyclic aromatic hydrocarbons in roots of three mangrove species in Jiulong River Estuary

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Z.Q.; Zheng, W.J.; Ma, L. [Xiamen University, Xiamen (China). School of Life Science

    2005-07-01

    The polycyclic aromatic hydrocarbons (PAHs) concentrations were determined in the root of three mangrove species (Kandelia candel, Avicennia marina and Bruguiera gymnorrhiza) and their growing environment (sediment) in mangrove wetlands of Jiulong River Estuary, Fujian, China. The total PAHs (16 parent PAHs) in mangrove sediments ranged from 193.44 to 270.53 ng/g dw, with a mean value of 231.76 +/- 31.78 ng/g dw. Compared with other mangrove and coastal marine sediments, the PAHs concentrations of all the sampling areas in this study were at relatively lower level. The total PAHs (13 parent PAHs) values varied from 30.83 to 62.73 ng/g dw in mangrove roots. Benzo(a) pyrene, fluoranthene and pyrene dominated in mangrove sediments. Based on ratios of phenathrene/anthracene, fluoranthene/pyrene and fluoranthene/pyrene + fluoranthene, the main possible sources of surface sediment PAHs were identified as grass, wood or coal combustion for mangrove wetlands of Jiulong River Estuary. Naphthalene and phenathrene were the most abundant compounds in mangrove roots. Sediment-to-vegetation bioconcentration factors (BCF(SV)s) were calculated and their relationships with PAHs' physico-chemical properties were investigated. The average BCF(SV)s of PAHs for three mangrove species roots were almost all under the level of 1 except for naphthalene. Good linear relationship between BCFSV values for mangrove roots and PAHs water solubility, octanol-water partitioning coefficients was derived in present study. The solubility and the octanol-water partition coefficient were proved to be good predictors for the accumulation of PAHs in mangrove roots, respectively.

  18. Organochlorine pesticide air-water exchange and bioconcentration in krill in the Ross Sea

    International Nuclear Information System (INIS)

    Cincinelli, Alessandra; Martellini, Tania; Del Bubba, Massimo; Lepri, Luciano; Corsolini, Simonetta; Borghesi, Nicoletta; King, Martin D.; Dickhut, Rebecca M.

    2009-01-01

    Mean hexachlorobenzene (HCB) and hexachlorocyclohexane (HCH) concentrations, measured in seawater and air samples, confirmed the decline in levels of these compounds in Antarctic air and water. However, low α/γ-HCH ratios in air at the beginning of the sampling period suggest a predominance of fresh lindane entering the Antarctic atmosphere during the Austral spring probably due to current use in the Southern Hemisphere. Water-air fugacity ratios demonstrate the potential for HCH gas deposition to coastal Antarctic seas, while the water-air fugacity ratios for HCB imply that volatilization does not account for the observed decrease of HCB in surface seawater. HCH concentrations found in krill samples were correlated with seawater concentrations indicative of bioconcentration of HCHs from seawater. - Hexachlorocyclohexanes (HCHs) continue to decline in Antarctic air, but fugacity ratios demonstrate that Antarctic coastal waters remain a sink for HCHs, which bioconcentrate in krill via direct uptake from water.

  19. Organochlorine pesticide air-water exchange and bioconcentration in krill in the Ross Sea

    Energy Technology Data Exchange (ETDEWEB)

    Cincinelli, Alessandra, E-mail: acincinelli@unifi.i [Department of Chemistry, University of Florence, Sesto Fiorentino, Florence (Italy); Martellini, Tania; Del Bubba, Massimo; Lepri, Luciano [Department of Chemistry, University of Florence, Sesto Fiorentino, Florence (Italy); Corsolini, Simonetta; Borghesi, Nicoletta [Department of Environmental Sciences, University of Siena, Siena (Italy); King, Martin D. [Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey (United Kingdom); Dickhut, Rebecca M. [Virginia Institute of Marine Science, Gloucester Point, VA (United States)

    2009-07-15

    Mean hexachlorobenzene (HCB) and hexachlorocyclohexane (HCH) concentrations, measured in seawater and air samples, confirmed the decline in levels of these compounds in Antarctic air and water. However, low alpha/gamma-HCH ratios in air at the beginning of the sampling period suggest a predominance of fresh lindane entering the Antarctic atmosphere during the Austral spring probably due to current use in the Southern Hemisphere. Water-air fugacity ratios demonstrate the potential for HCH gas deposition to coastal Antarctic seas, while the water-air fugacity ratios for HCB imply that volatilization does not account for the observed decrease of HCB in surface seawater. HCH concentrations found in krill samples were correlated with seawater concentrations indicative of bioconcentration of HCHs from seawater. - Hexachlorocyclohexanes (HCHs) continue to decline in Antarctic air, but fugacity ratios demonstrate that Antarctic coastal waters remain a sink for HCHs, which bioconcentrate in krill via direct uptake from water.

  20. Bioconcentration and acute toxicity of polycyclic musks in two benthic organisms (Chironomus riparius and Lumbriculus variegatus)

    NARCIS (Netherlands)

    Artola-Garicano, E.; Sinnige, T.L.; Holsteijn, I. van; Vaes, W.H.J.; Hermens, J.L.M.

    2003-01-01

    In the current study, the bioconcentration behavior and acute toxicity of two polycyclic musks, Tonalide® 7-acetyl-1,1,3,4,4,6,-hexamethyl-1,2,3,4,-tetrahydronaphthalene (AHTN) and Galaxolide® 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexa-methyl-cyclopenta[γ]-2- benzopyran (HHCB), were studied in two

  1. Growth and metal bioconcentration by conspecific freshwater macroalgae cultured in industrial waste water

    Directory of Open Access Journals (Sweden)

    Michael B. Ellison

    2014-05-01

    Full Text Available The bioremediation of industrial waste water by macroalgae is a sustainable and renewable approach to the treatment of waste water produced by multiple industries. However, few studies have tested the bioremediation of complex multi-element waste streams from coal-fired power stations by live algae. This study compares the ability of three species of green freshwater macroalgae from the genus Oedogonium, isolated from different geographic regions, to grow in waste water for the bioremediation of metals. The experiments used Ash Dam water from Tarong power station in Queensland, which is contaminated by multiple metals (Al, Cd, Ni and Zn and metalloids (As and Se in excess of Australian water quality guidelines. All species had consistent growth rates in Ash Dam water, despite significant differences in their growth rates in “clean” water. A species isolated from the Ash Dam water itself was not better suited to the bioremediation of that waste water. While there were differences in the temporal pattern of the bioconcentration of metals by the three species, over the course of the experiment, all three species bioconcentrated the same elements preferentially and to a similar extent. All species bioconcentrated metals (Cu, Mn, Ni, Cd and Zn more rapidly than metalloids (As, Mo and Se. Therefore, bioremediation in situ will be most rapid and complete for metals. Overall, all three species of freshwater macroalgae had the ability to grow in waste water and bioconcentrate elements, with a consistent affinity for the key metals that are regulated by Australian and international water quality guidelines. Together, these characteristics make Oedogonium a clear target for scaled bioremediation programs across a range of geographic regions.

  2. Bioconcentration and distribution of silver nanoparticles in Japanese medaka (Oryzias latipes)

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Youn-Joo [Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST) , 261 Cheom-dan Gwagi-ro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Kim, Ki-Tae [Department of Environmental Engineering, Seoul National University of Science and Technology, Seoul 139-743 (Korea, Republic of); Kim, Jun. Y. [Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST) , 261 Cheom-dan Gwagi-ro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Yang, Song-Yi; Lee, Byeong-Gweon [Department of Oceanography, Chonnam National University, Gwangju 500-755 (Korea, Republic of); Kim, Sang D., E-mail: sdkim@gist.ac.kr [Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST) , 261 Cheom-dan Gwagi-ro, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2014-02-01

    Highlights: • The bioconcentration and biodistribution of AgNPs were measured by the silver isotope {sup 110m}Ag. • BCF values were 39.8 ± 7.4, 42.5 ± 5.1 and 116.4 ± 6.1 L kg{sup −1} for AgNPs-CIT, AgNPs-PVP and AgNO{sub 3}, respectively. • The extent of silver ion release from AgNPs affected the uptake kinetic pattern. • AgNPs were mainly concentrated in the liver of Japanese medaka. - Abstract: The study of the bioconcentration of silver nanoparticles (AgNPs) is important to fully understand their hazard potential in the aquatic environment. We synthesized AgNPs radiolabeled with silver isotopes ({sup 110m}Ag) to quantify the bioconcentration of AgNPs coated with citrate (AgNPs-CIT) and polyvinylpyrrolidone (AgNPs-PVP) in Japanese medaka, and to investigate the biodistribution of silver in organs, which were compared with {sup 110m}AgNO{sub 3}. BCF values were determined to be 39.8 ± 7.4, 42.5 ± 5.1 and 116.4 ± 6.1 L kg{sup −1} for AgNPs-CIT, AgNPs-PVP and AgNO{sub 3}, respectively. The release of more silver ions in AgNPs-PVP contributed to a different kinetic uptake pattern with AgNPs-CIT, which was similar to that of AgNO{sub 3}. Bioconcentrated AgNPs in medaka were not observed to be eliminated, independent of surface coating differences, similarly to AgNO{sub 3}. There was no difference in biodistribution in each organ before and after depuration in two types of AgNPs and AgNO{sub 3}, all of which were mainly concentrated in the liver. This study quantified the bioconcentration and distribution of AgNPs and AgNO{sub 3} more precisely by utilizing a silver isotope, which is helpful in monitoring the toxicity of AgNPs to Japanese medaka.

  3. Effects of titanium dioxide nanoparticles on lead bioconcentration and toxicity on thyroid endocrine system and neuronal development in zebrafish larvae.

    Science.gov (United States)

    Miao, Wei; Zhu, Biran; Xiao, Xiaohong; Li, Ying; Dirbaba, Niguse Bekele; Zhou, Bingsheng; Wu, Hongjuan

    2015-04-01

    Nanoparticles (NPs) have attracted considerable attention because of their wide range of applications. Interactions between heavy metals (e.g., Pb) and NPs in aquatic environments may modify the bioavailability and toxicity of heavy metals. Therefore, this study investigated the influence of NPs (e.g., nano-TiO2) on the bioavailability and toxicity of Pb and its effects in the thyroid endocrine and nervous systems of zebrafish (Danio rerio) larvae. Zebrafish embryos (2-h post-fertilization) were exposed to five concentrations of Pb alone (0, 5, 10, 20, and 30μg/L) or in combination with nano-TiO2 (0.1mg/L) until 6 days post-fertilization. Results showed that the bioconcentration of Pb was significantly enhanced when combined with nano-TiO2 than when used alone. Zebrafish exposure to Pb alone at 30μg/L significantly decreased the thyroid hormone levels (T4 and T3), whereas nano-TiO2 treatment alone did not produce detectable changes. The levels of T4 and T3 were further decreased when Pb was combined with nano-TiO2 than when used alone. The transcription of the thyroid hormone-related factor tg gene was remarkably down-regulated by Pb treatment alone but up-regulated when Pb was combined with nano-TiO2. The significant up-regulation of tshβ gene and the down-regulation of TTR gene expression in the hypothalamic-pituitary-thyroid were observed in Pb with or without nano-TiO2 treatment groups. In addition, the transcription of genes involved in central nervous system (CNS) development (α-tubulin, mbp, gfap and shha) were significantly down-regulated by Pb and nano-TiO2 co-exposure as compared with Pb exposure alone. The locomotion activity analyzes confirmed that nano-TiO2 might enhance the toxicity of Pb to CNS development. These results suggest that nano-TiO2 increase bioconcentration of lead, which lead to the disruption of thyroid endocrine and neuronal system in zebrafish larvae. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Short-term bioconcentration studies of Np in freshwater biota

    International Nuclear Information System (INIS)

    Poston, T.M.; Klopfer, D.C.; Simmons, M.A.

    1990-01-01

    Short-term laboratory exposures were conducted to determine the potential accumulation of Np in aquatic organisms. Concentration factors were highest in green algae. Daphnia magna, a filter-feeding crustacean, accumulated Np at levels one order of magnitude greater than the amphipod Gammarus sp., an omnivorous substrate feeder. Accumulation of Np in juvenile rainbow trout (Oncorhynchus mykiss) was highest in carcass (generally greater than 78% of the total body burden) and lowest in fillets. Recommended concentration factors for Np, based on fresh weight, were 300 for green algae, 100 for filter-feeding invertebrates, for nonfilter-feeding invertebrates, 10 for whole fish, and one for fish flesh

  5. The bioconcentration of {sup 131}I in fresh water fish

    Energy Technology Data Exchange (ETDEWEB)

    Yu, K.N.; Cheung, T.; Young, E.C.M.; Luo, D.L. [City Univ. of Hong Kong, Kowloon (Hong Kong)

    1996-11-01

    The dynamic characteristics of the radionuclide concentration process in fresh water fish have been studied. The experimental data for the tilapias were fitted using a simple compartment model to get characteristics parameters such as concentration factors, elimination rate constants, and initial concentration rates, which are 3.08 Bq kg{sup {minus}1}/Bq L{sup {minus}1}, 0.00573 h{sup {minus}1}, and 12.42 Bq kg{sup {minus}1} h{sup {minus}1}, respectively. The relative concentrations of {sup 131}I in different parts, i.e., head, gills, flesh, bone and internal organs, of the tilapias are also determined, which are found to be 10.8, 15.4, 26.1, 11.0, and 37.0%, respectively. The effects of different factors on the transfer of radionuclides in fresh water fishes are also discussed. Experiments on the tilapias and the common carp show that the variation of concentration factors for different species may be significant even for the same radionuclide and the same ecological system. On the other hand, the variation in the concentration factors for the flesh of the tilapias is not significant for a certain range of {sup 131}I concentrations in the water. 12 refs., 1 fig., 1 tab.

  6. The bioconcentration of 131I in fresh water fish

    International Nuclear Information System (INIS)

    Yu, K.N.; Cheung, T.; Young, E.C.M.; Luo, D.L.

    1996-01-01

    The dynamic characteristics of the radionuclide concentration process in fresh water fish have been studied. The experimental data for the tilapias were fitted using a simple compartment model to get characteristics parameters such as concentration factors, elimination rate constants, and initial concentration rates, which are 3.08 Bq kg -1 /Bq L -1 , 0.00573 h -1 , and 12.42 Bq kg -1 h -1 , respectively. The relative concentrations of 131 I in different parts, i.e., head, gills, flesh, bone and internal organs, of the tilapias are also determined, which are found to be 10.8, 15.4, 26.1, 11.0, and 37.0%, respectively. The effects of different factors on the transfer of radionuclides in fresh water fishes are also discussed. Experiments on the tilapias and the common carp show that the variation of concentration factors for different species may be significant even for the same radionuclide and the same ecological system. On the other hand, the variation in the concentration factors for the flesh of the tilapias is not significant for a certain range of 131 I concentrations in the water. 12 refs., 1 fig., 1 tab

  7. Bio-concentration of Polycyclic Aromatic Hydrocarbons in the grey Mangrove (Avicennia marina along eastern coast of the Red Sea

    Directory of Open Access Journals (Sweden)

    El-Amin Bashir M.

    2017-12-01

    Full Text Available There are numerous sources of chemical pollutants which can impact the mangrove ecosystem through adjacent waters, industrial and sewage discharges and air depositions. Polycyclic aromatic hydrocarbons (PAHs are semi volatile ubiquitous anthropogenic pollutants detected in all environmental compartments. In the monitoring framework for the mangrove ecosystem along the Red Sea coast of Saudi Arabia, nine mangrove stands were examined for the accumulation of PAHs. Polycyclic aromatic hydrocarbons were measured using Gas Chromatography-Mass Spectrometry (GC-MS. The mean values detected for total PAHs in sediments, roots and leaf were 2.98, 8.57 and 23.43 ng/g respectively. The trend of the total PAHs concentration in all sites showed the descending order: leaf > roots > sediments. Beside the sandy nature of the sediments, the presences of all stands in remote areas fare from the direct anthropogenic effects lead to these relative low values. PAH bio-concentration factors for leaf are two to three magnitudes higher than that in roots, suggesting atmosphere deposition /leaf uptake mechanism in addition to the sediment/root mechanism. The diagnostic ratios revealed that the sources of PAHs are mainly pyrogenic.

  8. Fate, toxicity and bioconcentration of cadmium on Pseudokirchneriella subcapitata and Lemna minor in mid-term single tests.

    Science.gov (United States)

    Clément, Bernard; Lamonica, Dominique

    2018-03-01

    In the frame of a project which consists in modeling a laboratory microcosm under cadmium pressure, we initiated this study on the fate and effects of cadmium in the presence of either the microalga Pseudokirchneriella subcapitata or the duckweed Lemna minor, two organisms of the microcosm. For each organism, growth inhibition tests on a duration of 2-3 weeks were carried out with the objective of linking effects with total dissolved, ionic and internalized forms of cadmium. Numbers of organisms (algal cells or duckweed fronds) in 2-L beakers filled with synthetic nutritive medium containing EDTA were counted during the course of assays, while cadmium concentrations in the water and in the organisms were measured. Free cadmium fraction was calculated using PHREEQC, a computer program for chemical speciation. Results showed that cadmium toxicity to microalgae could be correlated to the free divalent fraction of this metal, limited by the presence of EDTA, and to its concentration in the organisms. Bioconcentration factors for our medium were suggested for P. subcapitata (111,000 on the basis of free cadmium concentration) and L. minor (17,812 on the basis of total dissolved concentration). No effect concentrations were roughly estimated around 400 µg/g for Pseudokirchneriella subcapitata and 200-300 µg/g for Lemna minor. This study is a first step towards a fate model based on chemical speciation for a better understanding of microcosm results.

  9. GENOTOXICITY AND BIOCONCENTRATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND HEAVY METALS IN LEUCISCUS CEPHALUS FROM PESCARA RIVER (ABRUZZO - ITALY: AN INTEGRATED APPROACH

    Directory of Open Access Journals (Sweden)

    Federica Piccoli

    2010-04-01

    Full Text Available The aim of the present study was to investigate the water quality and the ecosystem health of a segment of Pescara river (Abruzzo-Italy with the aid of an integrated approach. Sixteen priority polycyclic aromatic hydrocarbons and heavy metals were determinated in water and chub samples in order to calculate the bioconcentration factor. Biochemical, physical and microbiological characterisation were also carried out on water samples. Moreover, real and synergic effects of water pollution on biota were investigated by genotoxicological tests. Water samples were tested by Salmonella mutagenicity assay, whereas micronucleus assay on chub  was used to evaluate environmental genotoxic effects on fish. The characterisation of  water samples did not reveal any relevant contamination of Pescara river, but some analytical results obtained for biota were remarkable. In particular, the comparison between the site downstream from the industrial area of Chieti and the control site showed significant differences in chub micronuclei frequencies.

  10. Bioconcentration of artificial radionuclides in edible mushrooms: in situ and in vitro studies

    Energy Technology Data Exchange (ETDEWEB)

    Dementyev, Dmitry V.; Manukovsky, Nikolai S.; Bolsunovsky, Alexander Ya.; Alexandrova, Yuliyana V. [Institute of Biophysics, Siberian Branch of the Russian Academy of Sciences, 660036, Krasnoyarsk (Russian Federation)

    2014-07-01

    Some areas of the Yenisei River basin are affected by the operation of the Mining-and-Chemical Combine (MCC), producing weapons-grade plutonium. Flood plain soils of the Yenisei contain a wide range of artificial radionuclides, including transuranium elements, which can be accumulated by living organisms. Concentrations of artificial radionuclides and heavy metals accumulated by mushrooms may be several orders of magnitude higher than those accumulated by plants, and, thus, mushrooms may be used as bio-concentrators of radionuclides and heavy metals for bioremediation of contaminated areas. The purposes of this study were to investigate 1) species specificity of accumulation of artificial radionuclides by edible mushrooms in radioactively contaminated areas of the Yenisei River flood plain and 2) accumulation rates of artificial radionuclides, including transuranium elements, in mushrooms under laboratory conditions. Species specificity of accumulation of artificial radionuclides and uranium by mushrooms was analyzed for 12 species of edible mushrooms. The study was performed at the sites affected by MCC operation, which were divided into two groups: 1) the sites only affected by aerosol-bound radionuclides and 2) the sites that also received waterborne radionuclides. Field studies showed great interspecific variations in Cs-137 accumulation by mushrooms. Activity concentrations of Cs-137 in bioindicator species Suillus granulatus and S. Luteus reached 10 kBq/kg dry weight. S. granulatus and S. luteus are concentrators of Cs-137, as suggested by the analysis of concentration factors (CFs), which reached 0.7-16 for these mushroom species. The CF of U-238 in fruiting bodies of the mushrooms was no greater than 0.11. Yenisei flood plain soils contain a wide range of transuranium elements, which can accumulate in environmental objects. Laboratory experiments on accumulation of Am-241 from solution by mycelium and Am-241 accumulation by fruiting bodies of mushrooms

  11. Heavy Metal Accumulation as Phytoremediation Potential of Aquatic Macrophyte, Monochoria vaginalis (Burm.F.) K. Presl Ex Kunth

    OpenAIRE

    Tulika Talukdar; Dibyendu Talukdar

    2015-01-01

    Bioaccumulation potential of six ecotypes, collected from six different industrial zones of lower Indo-Gangetic basin of West Bengal, India,of Monochoria vaginalis, commonly known as oval-leafed pondweed has been investigated based on chromium (Cr), cadmium (Cd) andCopper (Cu) accumulation pattern in different plant organs. Bioaccumulation potential was assessed by bioaccumulation factors (BFs-leavesmetal concentration/soil metal concentration), bioconcentration factors (BCFs- roots metal/soi...

  12. Optimal choice of pH for toxicity and bioaccumulation studies of ionizing organic chemicals

    DEFF Research Database (Denmark)

    Rendal, Cecilie; Kusk, Kresten Ole; Trapp, Stefan

    2011-01-01

    at multiple pH levels. Toxicity and bioconcentration factors (BCFs) were higher for acids at lower pH values, whereas the opposite was true for bases. The effect of pH was most pronounced when pH-pKa was in the range of -1 to 3 for acids, and -3 to 1 for bases. The factor by which toxicity and BCF changed...

  13. Mercury in Orange Birch Bolete Leccinum versipelle and soil substratum: bioconcentration by mushroom and probable dietary intake by consumers.

    Science.gov (United States)

    Krasińska, Grażyna; Falandysz, Jerzy

    2016-01-01

    The aim of this study was to examine the contamination, accumulation, and distribution of mercury in fruiting bodies by Leccinum versipelle fungus collected from distant sites across Poland. Mercury was determined using validated method by cold-vapor atomic absorption spectroscopy after direct sample matrix combustion. A large set of data gained using 371 fruiting bodies and 204 soil samples revealed the susceptibility of L. versipelle to Hg contamination and permitted the estimation of probable intake of Hg contaminant by consumers foraging for this species. The range of median values of Hg determined in caps of L. versipelle was from 0.20 to 2.0 mg kg(-1) dry biomass, and the median for 19 localities was 0.65 mg kg(-1) dry biomass. The values of the Hg bioconcentration factor (BCF) determined for L. versipelle correlated negatively with Hg contents. Mercury in topsoil beneath L. versipelle ranged from 0.019 to 0.041 mg kg(-1) dry matter for less-contaminated locations (BCF of 17 to 65 for caps) and from 0.076 to 0.39 mg kg(-1) dry matter for more contaminated locations (BCF of 1.9 to 22). Fruiting bodies of L. versipelle collected in some regions of Poland if consumed in amount of 300 g in one meal in a week could provide Hg doses above the provisionally tolerable weekly intake (PTWI) value of 0.004 mg Hg kg(-1) body mass, while regular consumptions for most of the locations were below the limit even with more frequent consumption. Also summarized are available data on Hg for three species of fungi of genus Leccinum foraged in Europe.

  14. Organochlorine pesticide air-water exchange and bioconcentration in krill in the Ross Sea.

    Science.gov (United States)

    Cincinelli, Alessandra; Martellini, Tania; Del Bubba, Massimo; Lepri, Luciano; Corsolini, Simonetta; Borghesi, Nicoletta; King, Martin D; Dickhut, Rebecca M

    2009-07-01

    Mean hexachlorobenzene (HCB) and hexachlorocyclohexane (HCH) concentrations, measured in seawater and air samples, confirmed the decline in levels of these compounds in Antarctic air and water. However, low alpha/gamma-HCH ratios in air at the beginning of the sampling period suggest a predominance of fresh lindane entering the Antarctic atmosphere during the Austral spring probably due to current use in the Southern Hemisphere. Water-air fugacity ratios demonstrate the potential for HCH gas deposition to coastal Antarctic seas, while the water-air fugacity ratios for HCB imply that volatilization does not account for the observed decrease of HCB in surface seawater. HCH concentrations found in krill samples were correlated with seawater concentrations indicative of bioconcentration of HCHs from seawater.

  15. Plant Uptake of Organic Pollutants from Soil: A Critical Review ofBioconcentration Estimates Based on Modelsand Experiments

    Energy Technology Data Exchange (ETDEWEB)

    McKone, Thomas E.; Maddalena, Randy L.

    2007-01-01

    The role of terrestrial vegetation in transferring chemicals from soil and air into specific plant tissues (stems, leaves, roots, etc.) is still not well characterized. We provide here a critical review of plant-to-soil bioconcentration ratio (BCR) estimates based on models and experimental data. This review includes the conceptual and theoretical formulations of the bioconcentration ratio, constructing and calibrating empirical and mathematical algorithms to describe this ratio and the experimental data used to quantify BCRs and calibrate the model performance. We first evaluate the theoretical basis for the BCR concept and BCR models and consider how lack of knowledge and data limits reliability and consistency of BCR estimates. We next consider alternate modeling strategies for BCR. A key focus of this evaluation is the relative contributions to overall uncertainty from model uncertainty versus variability in the experimental data used to develop and test the models. As a case study, we consider a single chemical, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and focus on variability of bioconcentration measurements obtained from 81 experiments with different plant species, different plant tissues, different experimental conditions, and different methods for reporting concentrations in the soil and plant tissues. We use these observations to evaluate both the magnitude of experimental variability in plant bioconcentration and compare this to model uncertainty. Among these 81 measurements, the variation of the plant/soil BCR has a geometric standard deviation (GSD) of 3.5 and a coefficient of variability (CV-ratio of arithmetic standard deviation to mean) of 1.7. These variations are significant but low relative to model uncertainties--which have an estimated GSD of 10 with a corresponding CV of 14.

  16. Distinguishing metal bioconcentration from particulate matter in moss tissue: Testing methods of removing particles attached to the moss surface

    Energy Technology Data Exchange (ETDEWEB)

    Spagnuolo, V.; Giordano, S. [Department of Biology, University of Naples Federico II, Via Cintia 4, I-80126 Napoli (Italy); Pérez-Llamazares, A.; Ares, A.; Carballeira, A.; Fernández, J.A. [Area de Ecología, Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Aboal, J.R., E-mail: jesusramon.aboal@usc.es [Area de Ecología, Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

    2013-10-01

    Accurate differentiation of the proportion of bioconcentrated metals (i.e. incorporated into cells) and the proportion that is not bioconcentrated (i.e. adsorbed at the surface) would lead to a better understanding of the uptake processes and would represent an advance in the use of mosses as biomonitors. Traditionally the methods used to remove contaminants that are not bioconcentrated were to wash the plant material with water or to apply the sequential elution technique, but nowadays both options are considered inaccurate for these purposes. The remaining possibilities are to clean the moss samples with a nitrogen jet or by power ultrasound. Samples of terrestrial moss Pseudoscleropodium purum (Hewd.) Fleisch. were collected from five sampling stations. Different nitrogen jet cleaning procedures and ultrasound cleaning procedures were applied to the mosses. To determine whether any of the treatments altered the membrane integrity of the moss samples, the concentrations of K were determined. The shoots were observed under a scanning electron microscope, and the size and number of particles were determined. Nitrogen jet cleaning was determined to be unacceptable because it damaged the phyllids and/or altered the membrane permeability and did not eliminate the particles from the moss surface. Moreover, ultrasound cleaning treatment should also discarded because of the loss of extracellular metals that are transferred to the water in which the moss is cleaned. - Highlights: • The cleaning of surface particles on mosses is an unresolved issue • The use of a nitrogen jet as cleaning procedure was ruled out • The use of ultrasound treatments as cleaning procedure was also discarded • Currently it is not possible to quantify the bioconcentrated metal fraction in mosses.

  17. Distinguishing metal bioconcentration from particulate matter in moss tissue: Testing methods of removing particles attached to the moss surface

    International Nuclear Information System (INIS)

    Spagnuolo, V.; Giordano, S.; Pérez-Llamazares, A.; Ares, A.; Carballeira, A.; Fernández, J.A.; Aboal, J.R.

    2013-01-01

    Accurate differentiation of the proportion of bioconcentrated metals (i.e. incorporated into cells) and the proportion that is not bioconcentrated (i.e. adsorbed at the surface) would lead to a better understanding of the uptake processes and would represent an advance in the use of mosses as biomonitors. Traditionally the methods used to remove contaminants that are not bioconcentrated were to wash the plant material with water or to apply the sequential elution technique, but nowadays both options are considered inaccurate for these purposes. The remaining possibilities are to clean the moss samples with a nitrogen jet or by power ultrasound. Samples of terrestrial moss Pseudoscleropodium purum (Hewd.) Fleisch. were collected from five sampling stations. Different nitrogen jet cleaning procedures and ultrasound cleaning procedures were applied to the mosses. To determine whether any of the treatments altered the membrane integrity of the moss samples, the concentrations of K were determined. The shoots were observed under a scanning electron microscope, and the size and number of particles were determined. Nitrogen jet cleaning was determined to be unacceptable because it damaged the phyllids and/or altered the membrane permeability and did not eliminate the particles from the moss surface. Moreover, ultrasound cleaning treatment should also discarded because of the loss of extracellular metals that are transferred to the water in which the moss is cleaned. - Highlights: • The cleaning of surface particles on mosses is an unresolved issue • The use of a nitrogen jet as cleaning procedure was ruled out • The use of ultrasound treatments as cleaning procedure was also discarded • Currently it is not possible to quantify the bioconcentrated metal fraction in mosses

  18. Contamination status and accumulation features of persistent organochlorines in pet dogs and cats from Japan

    International Nuclear Information System (INIS)

    Kunisue, Tatsuya; Nakanishi, Shigeyuki; Watanabe, Mafumi; Abe, Takao; Nakatsu, Susumu; Kawauchi, Sakio; Sano, Akihiko; Horii, Akira; Kano, Yasumasa; Tanabe, Shinsuke

    2005-01-01

    Concentrations of persistent organochlorines (OCs) such as polychlorinated dibenzo-p-dioxin (PCDDs), dibenzofurans (PCDFs), biphenyls, dichlorodiphenyltrichloroethane and their metabolites (DDTs), hexachlorocyclohexane isomers, hexachlorobenzene, and chlordane compounds were determined in genital organs of pet dogs and cats and pet foods from Japan. Levels of OCs in dogs were relatively lower than those in cats, while residue levels in their diets were almost similar, implying that accumulation and elimination mechanisms of these contaminants are different between dogs and cats. When bioconcentration factors (BCFs) were estimated from concentrations of OCs in dogs, cats, and their diets, BCFs of all the OCs except PCDD/DFs exceeded 1.0 in cats. On the other hand, in all the dogs, BCFs of DDTs were below 1.0, suggesting that dogs do not bioconcentrate DDTs. Furthermore, BCFs of all the OCs except PCDD/DFs in dogs were notably lower than those in cats, suggesting that dogs have higher metabolic and elimination capacity for these contaminants than cats. When residue levels of OCs in livers, adipose tissue, and genital organs of two pet dogs were examined, hepatic sequestration of PCDD/DFs and oxychlordane was observed. - Pet dogs may have higher metabolic and elimination capacity for organochlorines than pet cats

  19. Acute toxicity, bioconcentration, elimination and antioxidant effects of fluralaner in zebrafish, Danio rerio.

    Science.gov (United States)

    Jia, Zhong-Qiang; Liu, Di; Sheng, Cheng-Wang; Casida, John E; Wang, Chen; Song, Ping-Ping; Chen, Yu-Ming; Han, Zhao-Jun; Zhao, Chun-Qing

    2018-01-01

    Fluralaner is a novel isoxazoline insecticide which shows high insecticidal activity against parasitic, sanitary and agricultural pests, but there is little information about the effect of fluralaner on non-target organisms. This study reports the acute toxicity, bioconcentration, elimination and antioxidant response of fluralaner in zebrafish. All LC 50 values of fluralaner to zebrafish were higher than 10 mg L -1 at 24, 48, 72 and 96 h. To study the bioconcentration and elimination, the zebrafish were exposed to sub-lethal concentrations of fluralaner (2.00 and 0.20 mg L -1 ) for 15 d and then held 6 d in clean water. The results showed medium BCF of fluralaner with values of 12.06 (48 h) and 21.34 (144 h) after exposure to 2.00 and 0.20 mg L -1 fluralaner, respectively. In the elimination process, a concentration of only 0.113 mg kg -1 was found in zebrafish on the 6th day after removal to clean water. After exposure in 2.00 mg L -1 fluralaner, the enzyme activities of SOD, CAT, and GST, GSH-PX, CarE and content of MDA were measured. Only CAT and CarE activities were significantly regulated and the others stayed at a stable level compared to the control group. Meanwhile, transcriptional expression of CYP1C2, CYP1D1, CYP11A were significantly down-regulated at 12 h exposed to 2.00 mg L -1 of fluralaner. Except CYP1D1, others CYPs were up-regulated at different time during exposure periods. Fluralaner and its formulated product (BRAVECTO ® ) are of low toxicity to zebrafish and are rapidly concentrated in zebrafish and eliminated after exposure in clean water. Antioxidant defense and metabolic systems were involved in the fluralaner-induced toxicity. Among them, the activities of CAT and CarE, and most mRNA expression level of CYPs showed fast response to the sub-lethal concentration of fluralaner, which could be used as a biomarker relevant to the toxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Distinguishing metal bioconcentration from particulate matter in moss tissue: testing methods of removing particles attached to the moss surface.

    Science.gov (United States)

    Spagnuolo, V; Giordano, S; Pérez-Llamazares, A; Ares, A; Carballeira, A; Fernández, J A; Aboal, J R

    2013-10-01

    Accurate differentiation of the proportion of bioconcentrated metals (i.e. incorporated into cells) and the proportion that is not bioconcentrated (i.e. adsorbed at the surface) would lead to a better understanding of the uptake processes and would represent an advance in the use of mosses as biomonitors. Traditionally the methods used to remove contaminants that are not bioconcentrated were to wash the plant material with water or to apply the sequential elution technique, but nowadays both options are considered inaccurate for these purposes. The remaining possibilities are to clean the moss samples with a nitrogen jet or by power ultrasound. Samples of terrestrial moss Pseudoscleropodium purum (Hewd.) Fleisch. were collected from five sampling stations. Different nitrogen jet cleaning procedures and ultrasound cleaning procedures were applied to the mosses. To determine whether any of the treatments altered the membrane integrity of the moss samples, the concentrations of K were determined. The shoots were observed under a scanning electron microscope, and the size and number of particles were determined. Nitrogen jet cleaning was determined to be unacceptable because it damaged the phyllids and/or altered the membrane permeability and did not eliminate the particles from the moss surface. Moreover, ultrasound cleaning treatment should also discarded because of the loss of extracellular metals that are transferred to the water in which the moss is cleaned. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Bioconcentration and Acute Intoxication of Brazilian Freshwater Fishes by the Methyl Parathion Organophosphate Pesticide

    Science.gov (United States)

    Bosco de Salles, João; Matos Lopes, Renato; de Salles, Cristiane M. C.; Cassano, Vicente P. F.; de Oliveira, Manildo Marcião; Cunha Bastos, Vera L. F.; Bastos, Jayme Cunha

    2015-01-01

    Three species of freshwater Brazilian fishes (pacu, Piaractus mesopotamicus; piavussu, Leporinus macrocephalus, and curimbatá, Prochilodus lineatus) were exposed to an acute dose of 5 ppm methyl parathion organophosphate pesticide. Three to five individuals per species were exposed, one at a time, to 40 liters tap water spiked with Folidol 600. Pesticide concentrations and cholinesterase (ChE) activities were evaluated in serum, liver, brain, heart, and muscle. The bioconcentration of methyl parathion was similar for all studied fishes. Brain tissue showed the highest pesticide concentration, reaching 80 ppm after exposure for 30 min to methyl parathion. Three to 5 hours of 5 ppm methyl parathion exposure provoked the death of all P. lineatus at 92% brain AChE inhibition, whereas fish from the other two species survived for up to 78 hours with less than 80% brain AChE inhibition. Our results indicate that acute toxic effects of methyl parathion to fish are correlated with brain AChE sensitivity to methyl paraoxon. PMID:26339593

  2. Bioconcentration and Acute Intoxication of Brazilian Freshwater Fishes by the Methyl Parathion Organophosphate Pesticide

    Directory of Open Access Journals (Sweden)

    João Bosco de Salles

    2015-01-01

    Full Text Available Three species of freshwater Brazilian fishes (pacu, Piaractus mesopotamicus; piavussu, Leporinus macrocephalus, and curimbatá, Prochilodus lineatus were exposed to an acute dose of 5 ppm methyl parathion organophosphate pesticide. Three to five individuals per species were exposed, one at a time, to 40 liters tap water spiked with Folidol 600. Pesticide concentrations and cholinesterase (ChE activities were evaluated in serum, liver, brain, heart, and muscle. The bioconcentration of methyl parathion was similar for all studied fishes. Brain tissue showed the highest pesticide concentration, reaching 80 ppm after exposure for 30 min to methyl parathion. Three to 5 hours of 5 ppm methyl parathion exposure provoked the death of all P. lineatus at 92% brain AChE inhibition, whereas fish from the other two species survived for up to 78 hours with less than 80% brain AChE inhibition. Our results indicate that acute toxic effects of methyl parathion to fish are correlated with brain AChE sensitivity to methyl paraoxon.

  3. Bioconcentration and transfer of the organophorous flame retardant 1,3-dichloro-2-propyl phosphate causes thyroid endocrine disruption and developmental neurotoxicity in zebrafish larvae.

    Science.gov (United States)

    Wang, Qiangwei; Lai, Nelson Lok-Shun; Wang, Xianfeng; Guo, Yongyong; Lam, Paul Kwan-Sing; Lam, James Chung-Wah; Zhou, Bingsheng

    2015-04-21

    Organophosphate flame retardants are emerging environmental contaminants, although knowledge of their health risks is limited. Here, thyroid hormone homeostasis and neuronal development was studied in the progeny of adult zebrafish exposed to tris(1,3-dichloro-2-propyl) phosphate (TDCPP). Adult zebrafish were exposed to TDCPP (0, 4, 20, and 100 μg/L) for 3 months. Increased generation of reactive oxygen species and reduced survival rates was observed in exposed F1 larvae. We also observed a significant decrease in plasma thyroxine and 3,5,3'-triiodothyronine levels in F0 females and F1 eggs/larvae. The mRNA and protein expression of factors associated with neuronal development (e.g., α1-tubulin, myelin basic protein, and synapsin IIa) were significantly downregulated in exposed F1 larvae, as was the level of the neurotransmitters dopamine, serotonin, gamma amino butyric acid, and histamine. Larval locomotion was significantly decreased in exposed fish, but there was no effect on acetylcholinesterase activity. Bioconcentration of TDCPP was observed in F0 fish. TDCPP was also detected in F1 eggs following parental exposure, indicating maternal transfer of this compound. This study uniquely shows that TDCPP can be transferred to the offspring of exposed adults, causing thyroid endocrine disruption and developmental neurotoxicity.

  4. Bioconcentration of 14 C-Carbofuran and 14 C- Lindane in fresh water Tilapia Nilitica and the bioavailability of their residues to rats

    International Nuclear Information System (INIS)

    Aly, M.A.S.; Afifi, L.M.

    1997-01-01

    Tilapia Nilotica were exposed to 14 C- carbofuran (125 MUg/1) and 14 C - lindane (80 MUg/1) for 96 h. Uptake period followed by 8 days depuration period. The bioconcentration factor (BCF) for carbofuran reached 32.4 at 12 h and 82 for lindane at 48 h. The amount of 14 C-activity found in fish treated with 14 C - carbofuran after the uptake period showed the following descending order: viscera > remaining parts > gills > muscles. In case of 14 C - lindane treated fish the recovered amount followed the order; remaining parts> viscera > gills muscles. During the depuration period, carbofuran residues taken up by fish were eliminated in 2 phases, an initial rapid phase followed by a slower gradual one. However, the rate of elimination in case of lindane was much slower especially during the first 2 days. At the end of the depuration period (8 days), the muscles (edible portion) contained 10% and 58% of 14 C -activity in case of carbofuran and lindane treated groups, respectively. Both insecticides proved to be bioavailable when rats were fed treated fish. Of the administered dose, 44.1% and 53.0% were excreted in urine and feces case of 14 C-carbofuran while in case of 14 C - lindane it was 30.9% and 41.7% for urine and feces, respectively. 2 figs., 2 tabs

  5. Acute toxicity and bioconcentration of 14C-fenvalerate in tilapianilotica, the Bioavilability and biological activity of its residues in rats

    International Nuclear Information System (INIS)

    Aly, M.A.S.

    2003-01-01

    Fresh water fish tilapia treated with 300 MU/L of 1 4C-fenvalerate died at 24 h post treatment with (Ld50, 12 h). however, when sand sediments were pure in the glass aquaria (250 g/L), 50% of fish survived with (Lc50 extended to 72-96 h) a bioconcentration factor (BCF) of 800 for fenvalerate was observed at 24 h in tilapia. Maximum accumulation of 1 4C-fenvalerate in fish was at 24 h (15.6 Mg/g) and 50% eliminated in 96 h. At the end of depuration period of 8 days 36% of radioactivity (3.0 Mg/g) could be recovered in fish (40% in head, the rest in different parts of body). In believability study, when rats were fed on dried fish the majority of radioactivity was eliminated at 48 h (19.0% in urine and 68.6% in faeces) with majority of radioactivity eliminated as fenvalerate equivalent in 5 days

  6. Bioconcentration of perfluoroalkyl substances by Chironomus plumosus larvae in water with different types of dissolved organic matters.

    Science.gov (United States)

    Wen, Wu; Xia, Xinghui; Chen, Xi; Wang, Haotian; Zhu, Baotong; Li, Husheng; Li, Yang

    2016-06-01

    The effects of four types of dissolved organic matters (DOM) on the bioconcentration of perfluoroalkyl substances (PFASs) in Chironomus plumosus larvae have been studied. The PFASs included perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorododecanoic acid (PFDoA). The DOM included humic acid (HA), fulvic acid (FA), tannic acid (TA), and a protein, peptone (PEP), and their concentrations ranged from 0 to 50 mg L(-1). The results showed that, upon bioconcentration equilibrium, the body burdens of longer perfluoroalkyl chain PFASs (PFOS, PFDA, PFUnA and PFDoA) decreased with PEP and HA concentrations while increased with FA and TA concentrations. When FA and TA concentrations increased from 0 to 50 mg L(-1), body burdens of these PFASs increased by 7.5%-148.8% and 5.7%-37.1%, respectively. However, the DOM had no significant impact on the body burdens of shorter perfluoroalkyl chain PFASs (PFOA and PFNA). All of the four types of DOM lowered not only the uptake rate constants (ku) of PFASs due to the decrease of freely dissolved PFAS concentrations, but also the elimination rate constants (ke) due to the inhibition effect of DOM on the PFAS elimination from the larvae. The reduction in the two constants varied with both DOM and PFAS types. In the presence of PEP and HA with larger molecular weights, the ku values decreased more than ke, leading to the decreased body burdens of longer perfluoroalkyl chain PFASs. As for FA and TA with smaller molecular weights, the ke values decreased more than ku, resulting in increased body burdens of longer perfluoroalkyl chain PFASs. This study suggests that the effects of DOM on PFAS bioconcentration depend not only on the concentration but also on the molecule weight of DOM, which should be considered in the bioavailability assessment of PFASs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Metal uptake by homegrown vegetables – The relative importance in human health risk assessments at contaminated sites

    International Nuclear Information System (INIS)

    Augustsson, Anna L.M.; Uddh-Söderberg, Terese E.; Hogmalm, K. Johan; Filipsson, Monika E.M.

    2015-01-01

    Risk assessments of contaminated land often involve the use of generic bioconcentration factors (BCFs), which express contaminant concentrations in edible plant parts as a function of the concentration in soil, in order to assess the risks associated with consumption of homegrown vegetables. This study aimed to quantify variability in BCFs and evaluate the implications of this variability for human exposure assessments, focusing on cadmium (Cd) and lead (Pb) in lettuce and potatoes sampled around 22 contaminated glassworks sites. In addition, risks associated with measured Cd and Pb concentrations in soil and vegetable samples were characterized and a probabilistic exposure assessment was conducted to estimate the likelihood of local residents exceeding tolerable daily intakes. The results show that concentrations in vegetables were only moderately elevated despite high concentrations in soil, and most samples complied with applicable foodstuff legislation. Still, the daily intake of Cd (but not Pb) was assessed to exceed toxicological thresholds for about a fifth of the study population. Bioconcentration factors were found to vary more than indicated by previous studies, but decreasing BCFs with increasing metal concentrations in the soil can explain why the calculated exposure is only moderately affected by the choice of BCF value when generic soil guideline values are exceeded and the risk may be unacceptable. - Highlights: • Uptake of Cd and Pb by lettuce and potatoes increased with soil contamination. • Consumption of homegrown vegetables may lead to a daily Cd intake above TDIs. • The variability in the calculated BCFs is high when compared to previous studies. • Exposure assessments are most sensitive to the choice of BCFs at low contamination

  8. Bioconcentration, metabolism and alterations of thyroid hormones of Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) in Zebrafish.

    Science.gov (United States)

    Xu, Tao; Wang, Qiangwei; Shi, Qipeng; Fang, Qi; Guo, Yongyong; Zhou, Bingsheng

    2015-09-01

    Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is an organophosphate widely used as a flame retardant, and has frequently been detected in the environment and biota. The present study investigates the bioconcentration and metabolism of TDCPP in fish. Zebrafish embryos (from 2h post-fertilization) were exposed to TDCPP (0, 4, 20 and 100μg/L) for six months. Exposure to TDCPP significantly induced phase I metabolic enzymes 7-ethoxyresorufin O-deethylase (EROD) and 7-methoxyresorufin O-demethylase (MROD) in fish. The mRNA expression of genes related to Phase I and II metabolic enzymes, such as cyp1a1, cyp1b1, cyp1c1 and ugt1ab were also significantly upregulated. Exposure to TDCPP significantly reduced plasma thyroxine (T4) and 3,5,3'-triiodothyronine (T3) levels in females. Chemicals analysis indicated significant levels of TDCPP and its metabolite, bis (1,3-dichloro-2-propyl) phosphate (BDCPP), in the liver. The present study reveals that exposure to low concentrations of TDCPP can cause bioconcentration in fish, and TDCPP can be readily metabolized in liver. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Bioconcentration of the antidepressant fluoxetine and its effects on the physiological and biochemical status in Daphnia magna.

    Science.gov (United States)

    Ding, Jiannan; Zou, Hua; Liu, Qingqing; Zhang, Shanshan; Mamitiana Razanajatovo, Roger

    2017-08-01

    The aim of this study was to evaluate the bioconcentration potential of fluoxetine and its biological effects in Daphnia magna. After 48h of waterborne exposure, the bioconcentration of fluoxetine in D. magna was determined to be 460.61 and 174.41Lkg -1 for nominal exposure concentrations of 0.5 and 5µgL -1 , respectively. Moreover, various biological endpoints, including physiological responses (filtration and ingestion rates), enzymatic biomarkers related to neurotoxicity [acetylcholinesterase (AChE)] and antioxidant defense [superoxide dismutase (SOD)], and an oxidative stress damage marker [malondialdehyde (MDA)], were assessed. Fluoxetine exposure increased the filtration rate of daphnia, while the ingestion rate was not obviously modified. AChE activity was significantly inhibited, highlighting the neurotoxicity of fluoxetine on D. magna. However, with some alterations in the SOD activity and MDA content, no obvious oxidative damage was observed in D. magna exposed to fluoxetine at the tested concentrations. These results indicate that fluoxetine can be accumulated and consequently induce physiological and biochemical perturbations in D. magna. Copyright © 2017. Published by Elsevier Inc.

  10. Study on the Heavy Metal Bioconcentrations of the Shadegan International Wetland Mosquitofish, Gambusia Affinis, by Inductively Coupled Plasma Technique

    Directory of Open Access Journals (Sweden)

    Hassan Nasirian

    2013-07-01

    Full Text Available The purpose of this study was to evaluate the levels of heavy metal bioconcentration of the mosquitofish (Gambusia affinis in Shadegan international wetland. Sampling including the water, waterbed sediment and mosquitofish was carried out from the selected sampling sites during October and November 2011, and analyzed by the ICP-OES. Results show that the water has poor qualitative condition, according to EPA and WHO water quality standards. The level of the water Cr in the selected sites in both months and the levels of Fe, Mn and Zn during October in the SW1 site were higher than the instrumental detection limits indicating that the water was contaminated with these metals in the mentioned sites and months. The levels of the waterbed sediment As, Co, Cr, Cu, Fe, Mn, Pb and Zn, and mosquitofish Cr, Cu, Fe, Mn, Zn, Co and Cd were much higher than the instrumental detection limits, indicating that the waterbed sediment and mosquitofish were contaminated with them during October and November in the selected sites. Statistical assessments reveal that there is a significant difference between the mentioned contaminated water, waterbed sediment and mosquitofish heavy metals (all P-values < 0.05. In overall, it is considered that the contaminated heavy metals can be accumulated in the waterbed sediment and bioconcentrated in the wildlife tissues, then finally can be entered in the marine food chains and biomagnified there after long periods. In conclusion, this paper confirmed that the G. affinis can be used as a bioindicator of heavy metal pollution in marine ecosystems such as wetlands

  11. Antidiabetic II drug metformin in plants: uptake and translocation to edible parts of cereals, oily seeds, beans, tomato, squash, carrots, and potatoes.

    Science.gov (United States)

    Eggen, Trine; Lillo, Cathrine

    2012-07-18

    Residues of pharmaceuticals present in wastewater and sewage sludge are of concern due to their transfer to aquatic and terrestrial food chains and possible adverse effects on nontargeted organisms. In the present work, uptake and translocation of metformin, an antidiabetic II medicine, by edible plant species cultivated in agricultural soil have been investigated in greenhouse experiment. Metformin demonstrated a high uptake and translocation to oily seeds of rape ( Brassica napus cv. Sheik and Brassica rapa cv. Valo); expressed as an average bioconcentration factor (BCF, plant concentration over initial concentration in soil, both in dry weight), BCF values as high as 21.72 were measured. In comparison, BCFs for grains of the cereals wheat, barley, and oat were in the range of 0.29-1.35. Uptake and translocation to fruits and vegetables of tomato (BCFs 0.02-0.06), squash (BCFs 0.12-0.18), and bean (BCF 0.88) were also low compared to rape. BCFs for carrot, potato, and leaf forage B. napus cv. Sola were similar (BCF 1-4). Guanylurea, a known degradation product of metformin by microorganisms in activated sludge, was found in barley grains, bean pods, potato peel, and small potatoes. The mechanisms for transport of metformin and guanidine in plants are still unknown, whereas organic cation transporters (OCTs) in mammals are known to actively transport such compounds and may guide the way for further understanding of mechanisms also in plants.

  12. Bioaccumulation of pharmaceutically active compounds and endocrine disrupting chemicals in aquatic macrophytes: Results of hydroponic experiments with Echinodorus horemanii and Eichhornia crassipes.

    Science.gov (United States)

    Pi, N; Ng, J Z; Kelly, B C

    2017-12-01

    Information regarding the bioaccumulation behaviour of pharmaceutically active compounds (PhACs) and endocrine disrupting chemicals (EDCs) in aquatic plants is limited. The present study involved controlled hydroponic experiments to assess uptake and elimination rate constants (k u , k e ), bioconcentration factors (BCFs) and translocation factors (TFs) of several PhACs and EDCs in two aquatic macrophyte species, including one submerged species (Echinodorus horemanii) and one free-floating species (Eichhornia crassipes). The results revealed that the studied compounds are readily taken up in these aquatic plants. While bioconcentration factors (BCFs) and translocation factors (TFs) of the test compounds varied substantially, no discernible relationship with physicochemical properties such as octanol-water distribution coefficient (D ow ), membrane-water distribution coefficient (D mw ) and organic carbon-water partition coefficient (K oc ). Diphenhydramine and triclosan exhibited the highest degree of uptake and bioaccumulation potential. For example, the whole-plant BCF of triclosan in E. horemanii was 4390L/kg, while the whole-plant BCF of diphenhydramine in E. crassipes was 6130L/kg. BCFs of 17β-estradiol (E2), 17α-ethinylestradiol (EE2), estrone (E1) and bisphenol A (BPA) were relatively low (2-150L/kg). BCFs were generally higher in free-floating aquatic macrophyte species compared to the submerged species. For the free-floating species, E. crassipes, the majority of PhACs and EDCs were more allocated in roots compared to leaves, with TFscaffeine, atrazine, diphenhydramine, E2 and carbamazepine were more allocated in leaf tissue (TFs>1). The study findings may be useful for design and implementation of phytoremediation systems, as well as aid future modeling and risk assessment initiatives for these emerging organic contaminants. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Long-Chain Perfluoroalkyl acids (PFAAs) Affect the Bioconcentration and Tissue Distribution of Short-Chain PFAAs in Zebrafish (Danio rerio).

    Science.gov (United States)

    Wen, Wu; Xia, Xinghui; Hu, Diexuan; Zhou, Dong; Wang, Haotian; Zhai, Yawei; Lin, Hui

    2017-11-07

    Short- and long-chain perfluoroalkyl acids (PFAAs), ubiquitously coexisting in the environment, can be accumulated in organisms by binding with proteins and their binding affinities generally increase with their chain length. Therefore, we hypothesized that long-chain PFAAs will affect the bioconcentration of short-chain PFAAs in organisms. To testify this hypothesis, the bioconcentration and tissue distribution of five short-chain PFAAs (linear C-F = 3-6) were investigated in zebrafish in the absence and presence of six long-chain PFAAs (linear C-F = 7-11). The results showed that the concentrations of the short-chain PFAAs in zebrafish tissues increased with exposure time until steady states reached in the absence of long-chain PFAAs. However, in the presence of long-chain PFAAs, these short-chain PFAAs in tissues increased until peak values reached and then decreased until steady states, and the uptake and elimination rate constants of short-chain PFAAs declined in all tissues and their BCF ss decreased by 24-89%. The inhibitive effect of long-chain PFAAs may be attributed to their competition for transporters and binding sites of proteins in zebrafish with short-chain PFAAs. These results suggest that the effect of long-chain PFAAs on the bioconcentration of short-chain PFAAs should be taken into account in assessing the ecological and environmental effects of short-chain PFAAs.

  14. Study on the heavy metal bioconcentrations of the Shadegan international wetland mosquitofish, Gambusia affinis, by inductively coupled plasma technique

    Science.gov (United States)

    2013-01-01

    The purpose of this study was to evaluate the levels of heavy metal bioconcentration of the mosquitofish (Gambusia affinis) in Shadegan international wetland. Sampling including the water, waterbed sediment and mosquitofish was carried out from the selected sampling sites during October and November 2011, and analyzed by the ICP-OES. Results show that the water has poor qualitative condition, according to EPA and WHO water quality standards. The level of the water Cr in the selected sites in both months and the levels of Fe, Mn and Zn during October in the SW1 site were higher than the instrumental detection limits indicating that the water was contaminated with these metals in the mentioned sites and months. The levels of the waterbed sediment As, Co, Cr, Cu, Fe, Mn, Pb and Zn, and mosquitofish Cr, Cu, Fe, Mn, Zn, Co and Cd were much higher than the instrumental detection limits, indicating that the waterbed sediment and mosquitofish were contaminated with them during October and November in the selected sites. Statistical assessments reveal that there is a significant difference between the mentioned contaminated water, waterbed sediment and mosquitofish heavy metals (all P-values bioindicator of heavy metal pollution in marine ecosystems such as wetlands. PMID:24499681

  15. Soil organic matter content effects on dermal pesticide bioconcentration in American toads (Bufo americanus).

    Science.gov (United States)

    Pesticides have been implicated as a major factor in global amphibian declines and may pose great risk to terrestrial phase amphibians moving to and from breeding ponds on agricultural landscapes. Dermal uptake from soil is known to occur in amphibians, but predicting pesticide a...

  16. In-situ partitioning and bioconcentration of polycyclic aromatic hydrocarbons among water, suspended particulate matter, and fish in the Dongjiang and Pearl Rivers and the Pearl River Estuary, China

    International Nuclear Information System (INIS)

    Li, Haiyan; Lu, Lei; Huang, Wen; Yang, Juan; Ran, Yong

    2014-01-01

    Highlights: • PAHs are relatively higher in marine fish than in freshwater fish. • PAHs respectively show significant correlations with DOC, POC, and Chl a. • The log K oc for PAHs is one order magnitude higher than the predicted. • The log BCF values in fish and their tissues are nonlinear in respect to log K ow . • Lipid is related to PAHs in freshwater fish, but not in marine fishes. - Abstract: The partitioning and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in water, suspended particulate matter (SPM), and fish samples from the Dongjiang River (DR), Pearl River (PR), and the Pearl River Estuary (PRE) were examined. Although PAHs are much lower in PRE than in DR or PR, PAHs in some fish species are significantly higher in PRE than in DR or PR. Aqueous or particulate PAHs respectively show significant correlations with dissolved organic carbon, particulate organic matter, and chlorophyll a, suggesting that biological pumping effect regulates their distribution. The in situ partitioning coefficients (log K oc ) for PAHs are one order magnitude higher than the empirical log K oc –log K ow correlation. The bioconcentration factor (BCF) is slightly higher for the marine fish than for the freshwater fish. The above phenomena indicate that BCF may vary due to the diversity of fish species, feeding habits, and metabolism of PAHs in fish

  17. Allometric relationships in the bioconcentration of heavy metals by the edible tropical clam Gafrarium tumidum

    International Nuclear Information System (INIS)

    Hedouin, L.; Metian, M.; Teyssie, J.-L.; Fowler, S.W.; Fichez, R.; Warnau, M.

    2006-01-01

    Although metal contamination is a problem of major concern in the lagoon of New Caledonia due to intense mining activities conducted on land, very little is known on the metal ecotoxicology of local marine organisms. The clam Gafrarium tumidum was investigated to assess its usefulness as a bioindicator species of metal contamination in this lagoon. More particularly, allometric relationships between metal accumulation and clam size were determined for five common metals in New Caledonian lagoon waters (Cd, Cr, Co, Zn and Ag) using a highly sensitive radiotracer technique. Experimental results showed that allometric relationships were dependent on the element and on the body compartment considered. As a rule, allometric relationships of metal concentration factor were more pronounced in shell than in soft parts. Significant relationships with clam size for Cd, Cr, Co and Zn followed inverse power functions. In contrast, the degree of Ag bioaccumulation was positively correlated with size. In view of the literature on Ag in bivalves, the latter observation suggests the occurrence of a specific detoxification mechanism (sequestration) that would be more efficient in old individuals. Overall, the experimental results indicate that the use of G. tumidum as a bioindicator in monitoring programmes requires selecting individuals of a specific size range in order to obtain comparable information about ambient metal levels. Since the size effect is greatest among smaller individuals, it is recommended to select clams with a shell width greater than 35 mm

  18. Acute exposure to synthetic pyrethroids causes bioconcentration and disruption of the hypothalamus–pituitary–thyroid axis in zebrafish embryos

    Energy Technology Data Exchange (ETDEWEB)

    Tu, Wenqing [Research Institute of Poyang Lake, Jiangxi Academy of Sciences, Nanchang 330029 (China); Institute of Environmental Science, College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Xu, Chao, E-mail: chaoxu@zjut.edu.cn [Institute of Environmental Science, College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Lu, Bin; Lin, Chunmian [Institute of Environmental Science, College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Wu, Yongming [Research Institute of Poyang Lake, Jiangxi Academy of Sciences, Nanchang 330029 (China); Liu, Weiping [Institute of Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China)

    2016-01-15

    Synthetic pyrethroids (SPs) have the potential to disrupt the thyroid endocrine system in mammals; however, little is known of the effects of SPs and underlying mechanisms in fish. In the current study, embryonic zebrafish were exposed to various concentrations (1, 3 and 10 μg/L) of bifenthrin (BF) or λ-cyhalothrin (λ-CH) until 72 h post fertilization, and body condition, bioaccumulation, thyroid hormone levels and transcription of related genes along the hypothalamus–pituitary–thyroid (HPT) axis examined. Body weight was significantly decreased in the λ-CH exposure groups, but not the BF exposure groups. BF and λ-CH markedly accumulated in the larvae, with concentrations ranging from 90.7 to 596.8 ng/g. In both exposure groups, alterations were observed in thyroxine (T{sub 4}) and triiodothyronine (T{sub 3}) levels. In addition, the majority of the HPT axis-related genes examined, including CRH, TSHβ, TTR, UGT1ab, Pax8, Dio2 and TRα, were significantly upregulated in the presence of BF. Compared to BF, λ-CH induced different transcriptional regulation patterns of the tested genes, in particular, significant stimulation of TTR, Pax8, Dio2 and TRα levels along with concomitant downregulation of Dio1. Molecular docking analyses revealed that at the atomic level, BF binds to thyroid hormone receptor (TRα) protein more potently than λ-CH, consequently affecting HPT axis signal transduction. In vitro and in silico experiments disclosed that during the early stages of zebrafish development, BF and λ-CH have the potential to disrupt thyroid endocrine system. - Highlights: • Following respective exposure of embryos to BF and λ-CH, thyroid endocrine disruption was investigated in zebrafish embryos. • Thyroid hormones (T3 and T4 levels) were significantly altered after being exposed to BF and λ-CH. • Gene transcription modulation in the HPT axis was examined. • BF and λ-CH bioconcentration in zebrafish larvae were evident. • BF binds to thyroid

  19. Survey on composition and bioconcentration potential of 12 metallic elements in King Bolete (Boletus edulis) mushroom that emerged at 11 spatially distant sites.

    Science.gov (United States)

    Falandysz, Jerzy; Frankowska, Aneta; Jarzynska, Grazyna; Dryzałowska, Anna; Kojta, Anna K; Zhang, Dan

    2011-01-01

    This paper provides data on baseline concentrations, interrelationships and bioconcentration potential of 12 metallic elements by King Bolete collected from 11 spatially distant sites across Poland. There are significant differences in concentrations of metals (Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Sr, Zn) and their bioconcentration potential in King Bolete Boletus edulis at 11 spatially distant sites surveyed across Poland. These have resulted from significant geographical differences in trace metal concentrations in a layer (0-10 cm) of organic and mineral soil underneath to fruiting bodies and possible local bioavailabilities of macro- (Ca, K, Mg, Na) and trace metals (Al, Ba, Cd, Cu, Fe, Mn, Sr, Zn) to King Bolete. The use of highly appreciated wild-grown edible King Bolete mushroom has established a baseline measure of regional minerals status, heavy metals pollution and assessment of intake rates for wild mushroom dish fanciers against which future changes can be compared. Data on Cd, Cu and Zn from this study and from literature search can be useful to set the maximum limit of these metals in King Bolete collected from uncontaminated (background) areas. In this report also reviewed are data on Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Sr and Zn accumulation in King Bolete.

  20. Distribution and bioconcentration of heavy metals in a tropical aquatic food web: A case study of a tropical estuarine lagoon in SE Mexico

    International Nuclear Information System (INIS)

    Mendoza-Carranza, Manuel; Sepúlveda-Lozada, Alejandra; Dias-Ferreira, Celia; Geissen, Violette

    2016-01-01

    Despite the increasing impact of heavy metal pollution in southern Mexico due to urban growth and agricultural and petroleum activities, few studies have focused on the behavior and relationships of these pollutants in the biotic and abiotic components of aquatic environments. Here, we studied the bioaccumulation of heavy metals (Cd, Cr, Ni, Pb, V, Zn) in suspended load, sediment, primary producers, mollusks, crustaceans, and fish, in a deltaic lagoon habitat in the Tabasco coast, with the aim to assess the potential ecological risk in that important wetland. Zn showed the highest concentrations, e.g., in suspended load (mean of 159.58 mg kg −1 ) and aquatic consumers (15.43–171.71 mg kg −1 ), particularly Brachyura larvae and ichthyoplankton (112.22–171.71 mg kg −1 ), followed by omnivore Callinectes sp. crabs (113.81–128.07 mg kg −1 ). The highest bioconcentration factors (BCF) of Zn were observed for planktivore and omnivore crustaceans (3.06–3.08). Zn showed a pattern of distribution in the food web through two pathways: the pelagic (where the higher concentrations were found), and the benthic (marsh plants, sediment, mollusk, fish). The other heavy metals had lower occurrences in the food web. Nevertheless, high concentrations of Ni and Cr were found in phytoplankton and sediment (37.62–119.97 mg kg −1 ), and V in epiphytes (68.64 mg kg −1 ). Ni, Cr, and Cd concentrations in sediments surpassed international and national threshold values, and Cd entailed a “considerable” potential risk. These heavy metals are most likely transferred into the food web up to fishes through the benthic pathway. Most of the collected fishes are residents in this type of habitat and have commercial importance. Our results show that the total potential ecological risk in the area can be considered as “moderate”. Nevertheless, heavy metal values were similar or surpassed the values from other highly industrialized tropical coastal regions

  1. Bioconcentration and metabolism of BDE-209 in the presence of titanium dioxide nanoparticles and impact on the thyroid endocrine system and neuronal development in zebrafish larvae.

    Science.gov (United States)

    Wang, Qiangwei; Chen, Qi; Zhou, Peng; Li, Wenwen; Wang, Junxia; Huang, Changjiang; Wang, Xianfeng; Lin, Kuangfei; Zhou, Bingsheng

    2014-08-01

    Interactions between organic toxicants and nanoparticles (NPs) in the aquatic environment may modify toxicant bioavailability and consequently the toxicant's environmental fate and toxicity. Therefore, we investigated the influence of titanium dioxide NPs (nano-TiO2) on deca-BDE (BDE-209; a polybrominated diphenyl ether congener) bioconcentration, metabolism and its effects on the thyroid endocrine system in zebrafish (Danio rerio) larvae. Zebrafish embryos were exposed to various concentrations of BDE-209 alone or in combination with nano-TiO2 (0.1 mg/L) until 7-day post-fertilization. Nano-TiO2 can adsorb BDE-209 and nano-TiO2 is taken up into developing zebrafish larvae. Chemical measurements showed that BDE-209 was bioconcentrated and metabolized in zebrafish larvae, and BDE-209 uptake was enhanced by nano-TiO2. Furthermore, increased BDE-209 metabolites were detected in larvae co-exposed with nano-TiO2. BDE-209 exposure significantly increased whole-body thyroid hormone contents (T3 and T4); T4 content significantly increased in the larvae co-exposed with nano-TiO2. Nano-TiO2 exposure alone did not induce generation of reactive oxygen species, lipid peroxidative oxidation, gene transcription or thyroid hormone levels. Upregulation of several gene transcriptions (tshβ, tg, dio2) in the hypothalamic-pituitary-thyroid axis was also observed. Furthermore, co-exposure of nano-TiO2 and BDE-209 caused a decrease in locomotion activity and downregulation of specific genes and proteins involved in the central nervous system of developing zebrafish larvae (e.g. myelin basic protein and α1-tubulin). These results indicate nano-TiO2 enhances BDE-209 bioavailability and metabolism, leading to thyroid endocrine disruption and developmental neurotoxicity in zebrafish.

  2. Inheritance of p,p'-DDE phytoextraction ability in hybridized Cucurbita pepo cultivars.

    Science.gov (United States)

    White, Jason C

    2010-07-01

    Cucurbita pepo ssp pepo (zucchini) has been shown to uniquely phytoextract percent level amounts of dichlorodiphenyldichloroethylene (DDE) and other organic contaminants from soil. Since C. pepo ssp ovifera (squash) does not have this ability, a three-year field trial was conducted to follow the inheritance pattern of DDE accumulation for cross pollinated C. pepo cultivars. Parental zucchini and squash cultivars (3 each) had stem-to-soil bioconcentration factors (BCF, contaminant ratio of stem to soil) of 16 and 1.7, respectively, and phytoextracted 1.8 and 0.18% of the DDE from soil. The 18 possible first filial (F1) hybrids of zucchini and squash accumulated significantly different DDE levels than the respective parents. The zucchini F1 hybrid (zucchini pollinated with squash) stem BCFs and percent phytoextraction values were 10 and 0.96, respectively, or 36% and 47% less than the parental zucchini. The squash F1 hybrid (squash pollinated with zucchini) stem BCFs and percent phytoextraction values were 8.3 and 0.68, respectively, or 490% and 370% greater than the parental squash. When backcrossed (BC) with the original parent, the nine zucchini F1 BC cultivars did not regain the capability to take up DDE; stem BCFs and percent phytoextraction values were equivalent to those of the F1 generation. However, the nine squash F1 BC cultivars lost much of the DDE uptake capability of the F1 generation; stem BCFs and percent phytoextraction values were intermediate but closer to those of the parental squash. The inheritance patterns suggest single locus control for persistent organic pollutant (POP) uptake ability in C. pepo ssp pepo.

  3. Bioindication of mercury, arsenic and uranium in the apple snail Pomacea canaliculata (Caenogastropoda, Ampullariidae): Bioconcentration and depuration in tissues and symbiotic corpuscles.

    Science.gov (United States)

    Campoy-Diaz, Alejandra D; Arribére, María A; Guevara, Sergio Ribeiro; Vega, Israel A

    2018-04-01

    Pomacea canaliculata is a mollusk potentially useful as a biomonitor species of freshwater quality. This work explores the ability of snail tissues and symbiotic corpuscles to bioconcentrate and depurate mercury, arsenic, and uranium. Adult snails cultured in metal-free reconstituted water were exposed for eight weeks (bioaccumulation phase) to water with Hg (2 μgL -1 ), As (10 μgL -1 ), and U (30 μgL -1 ) and then returned to the reconstituted water for other additional eight weeks (depuration phase). Elemental concentrations in digestive gland, kidney, symbiotic corpuscles and particulate excreta were determined by neutron activation analysis. The glandular symbiotic occupancy was measured by morphometric analysis. After exposure, the kidney showed the highest concentration of Hg, while the digestive gland accumulated mainly As and U. The subcellular distribution in symbiotic corpuscles was ∼71%, ∼48%, and ∼11% for U, Hg, and As, respectively. Tissue depuration between weeks 8 and 16 was variable amongst elements. At week 16, the tissue depuration of U was the highest (digestive gland = 92%; kidney = 80%), while it was lower for Hg (digestive gland = 51%; kidney = 53%). At week 16, arsenic showed a differential pattern of tissue depuration (digestive gland = 23%; kidney = 88%). The symbiotic detoxification of the three elements in excreta was fast between weeks 8 and 10 and it was slower after on. At the end of the depuration, each element distributed differentially in digestive gland and symbiotic corpuscles. Our findings show that symbiotic corpuscles, digestive gland and kidney P. canaliculata are sensitive places for biomonitoring of Hg, As and U. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Accumulation and bioconcentration of polycyclic aromatic hydrocarbons in a nearshore estuarine environment near a Pensacola (Florida) creosote contamination site

    Science.gov (United States)

    Elder, J.F.; Dresler, P.V.

    1988-01-01

    Long-term accumulation of creosote wastes at a wood-preserving facility near Pensacola, Florida, has produced high levels of organic contamination of groundwaters near Pensacola Bay. Impacts of this contamination on the nearshore environment of the bay were examined by analysis of water, sediment and tissues of two mollusc species. One of the species (Thais haemastoma) was native to the study area. Individuals of the other test species (Crassostrea virginica) were placed in cages at the test sites for a 6-week period. Contamination at the nearshore estuarine sites was assessed by comparison to a control site in an uncontaminated area of the bay, as well as a small stream which forms a direct surface-water link between the creosote storage ponds and the bay. The study focused on polycyclic aromatic hydrocarbons (PAH), the primary components of creosote. Very little PAH in water or in the surface layer of estuarine sediments was detected, despite heavy pollution of the stream sediments. This is attributed to various degradation processes which attack the PAH compounds once they discharge into the estuary, and to the likelihood of intermittent and localised release of contaminants to the estuary. Examination of sediment cores and mollusc tissues, which provide a record integrated over time and space, revealed some accumulation of a few PAH, notably fluoranthene, pyrene, benzo(a)anthracene, chrysene and phenanthrene. In the sediments, the highest concentrations of these compounds appeared below the surface, within a depth range of 8-13 cm. Bioaccumulation of fluoranthene, pyrene and phenanthrene in both mollusc species was up to ten times greater at test sites than at the control site. This contrasts with naphthalene, the bioaccumulation of which was no greater at test sites than at the control site. These differences in bioaccumulation factors relate to structural chemistry of the compounds which control their solubility, bioavailability, susceptibility to degradation

  5. Heavy metals bioconcentration from soil to vegetables and appraisal of health risk in Koka and Wonji farms, Ethiopia.

    Science.gov (United States)

    Eliku, Temesgen; Leta, Seyoum

    2017-04-01

    Heavy metal accumulation in agricultural crops has grown a major concern globally as a result of a significant health impact on human. The quantification of heavy metals (Cd, Pb, Cr, Zn, Cu, and Ni) in the soil and vegetables at two sites (Koka and Wonji Gefersa) was done using flame atomic absorption spectrophotometer. The mean concentrations of heavy metals in vegetable fields' soil samples obtained from Koka were higher for Pb, Cr, Zn, Cu, and Ni. The overall results of soil samples ranged 0.52-0.93, 13.6-27.3, 10.0-21.8, 44.4-88.5, 11.9-30.3, and 14.7-34.5 mg kg -1 for Cd, Pb, Cr, Zn, Cu, and Ni, respectively. The concentrations of heavy metals were maximum for Cd (0.41 ± 0.03 mg kg -1 ), Pb (0.54 ± 0.11 mg kg -1 ), Zn (14.4 ± 0.72 mg kg -1 ), Cu (2.84 ± 0.27 mg kg -1 ), and Ni (1.09 ± 0.11 mg kg -1 ) in Cabbage and for Cr (2.63 ± 0.11 mg kg -1 ) in green pepper. The result indicated that Cd has high transfer factor value and Pb was the lowest. The transfer pattern for heavy metals in different vegetables showed a trend in the order: Cd > Zn > Cu > Cr > Ni > Pb. Among different vegetables, cabbage showed the highest value of metal pollution index and bean had the lowest value. Hazard index of all the vegetables was less than unity; thus, the consumption of these vegetables is unlikely to pose health risks to the target population.

  6. Using Fugacity Ratios to Compare Laboratory and Field Measured Bioaccumulation Endpoint Metrics

    Science.gov (United States)

    Bioconcentration (BCF) testing provides useful insights into the behavior of chemicals in the aquatic ecosystem that are useful for modeling and other applications. BCFs are also often used for chemical hazard screening and risk assessment. The question arises how well can we ext...

  7. Changes in bioaccumulation and translocation patterns between root and leafs of Avicennia schaueriana as adaptive response to different levels of metals in mangrove system.

    Science.gov (United States)

    Souza, Iara da C; Rocha, Lívia D; Morozesk, Mariana; Bonomo, Marina M; Arrivabene, Hiulana P; Duarte, Ian D; Furlan, Larissa M; Monferrán, Magdalena V; Mazik, Krysia; Elliott, Michael; Matsumoto, Silvia T; Milanez, Camilla R D; Wunderlin, Daniel A; Fernandes, Marisa N

    2015-05-15

    Espírito Santo estuaries (Brazil) are impacted by industrial activities, resulting in contamination of water and sediments. This raise questions on biological uptake, storage and consequences of metal contamination to mangrove plants. The goal of this work was evaluating accumulation and translocation of metals from sediment to roots and leaves of Avicennia schaueriana, growing in areas with different degrees of contamination, correlating bioaccumulation with changes in its root anatomy. Highest bioconcentration factors (BCFs) were observed in plants growing in less polluted areas. Conversely, highest translocation factors were found in plants from highest polluted area, evidencing an adaptive response of A. schaueriana to less favourable conditions. Namely, the absorption of metals by roots is diminished when facing highest levels of metals in the environment; alternatively, plants seem to enhance the translocation to diminish the concentration of toxic metals in roots. Root also responded to highly polluted scenarios with modifications of its anatomy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    International Nuclear Information System (INIS)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe; Sandberg, Johannes

    2010-06-01

    -stationary equilibrium within the model area. The coupled ecosystem and radionuclide models were used to simulate present conditions, i.e. 2020 AD. Six radionuclides were modelled explicitly in addition to C-14. They represent a wide range of accumulation potentials and partition coefficients (K d , distribution of radionuclides between water, sediment and biota). The ecosystem and associated radionuclide model include a detailed sediment module where radionuclides can be bound by adsorption to the organic and inorganic fractions, be precipitated, be transported by resuspension and later deposited at larger depths. With the exception of radionuclides with very low particle affinity, such as Cl-35, the majority of radionuclides released in basins where they were introduced via groundwater flow remained in the sediments even after a simulation period of eight years. The spread of radionuclides with high partition coefficients for sediments from areas with groundwater flow takes place by sediment resuspension and subsequent transport and sedimentation. In the case of radionuclides with lower partition coefficients, release from the sediments to the water column followed by transport of dissolved radionuclides by currents plays a larger role. A significant result of the modelling was the quantification of the seasonal and spatial variation in radionuclide accumulation and in bioconcentration factors (BCFs) with spatial variation of BCFs often ranging 2 to 3 orders of magnitude. This variation was dominated by spatial differences in concentrations of radionuclides in water. In basins where radionuclides were introduced by groundwater flow, BCFs were typically 2-3 orders of magnitude lower than in deep basins without radionuclide release in the groundwater. In phytoplankton and grazers, bioconcentration factors (BCFs) scaled linearly to partition coefficients (Kd), underlining the fact that adsorption is an important process for radionuclide accumulation in the lower parts of the food web

  9. Bioaccumulation and trophodynamics of the antidepressants sertraline and fluoxetine in laboratory-constructed, 3-level aquatic food chains.

    Science.gov (United States)

    Boström, Marja L; Ugge, Gustaf; Jönsson, Jan Åke; Berglund, Olof

    2017-04-01

    Although reports of pharmaceutical bioconcentration in aquatic organisms are increasing, less is known about trophic transfer in aquatic food webs. The bioaccumulation and trophodynamics of sertraline and fluoxetine, 2 selective serotonin reuptake inhibitors (SSRIs) frequently detected in aquatic environments, were tested by exposing constructed aquatic food chains to SSRIs under controlled laboratory conditions. Both of these ionizable, weak base pharmaceuticals showed lower bioaccumulation factors (BAFs) with increasing trophic level (i.e., no biomagnifications) in 2 3-level food chains (Acer platanoides, fed to Asellus aquaticus, in turn fed to Notonecta glauca or Pungitius pungitius). Mean sertraline BAFs in A. platanoides, A. aquaticus, N. glauca, and P. pungitus were 2200 L/kg, 360 L/kg, 26 L/kg, and 49 L/kg, respectively, and mean fluoxetine BAFs 1300 L/kg, 110 L/kg, 11 L/kg, and 41 L/kg, respectively. The weak influence of diet was further demonstrated by measured BAFs being equal to or lower than measured bioconcentration factors (BCFs). Organism lipid content was not positively correlated with BAFs, suggesting that other processes are driving interspecific differences in SSRI bioaccumulation. The empirically derived parameter values were introduced into a proposed bioaccumulation model, and a poor correlation was found between modeled and empirical BAFs (predicted r 2  = -0.63). In conclusion, the apparent lack of biomagnification of these ionizable pharmaceuticals suggests that environmental concern should not necessarily focus only on higher trophic levels, but also on species showing high BCFs at any trophic level. Environ Toxicol Chem 2017;36:1029-1037. © 2016 SETAC. © 2016 SETAC.

  10. Trace elements in fruiting bodies of ectomycorrhizal fungi growing in Scots pine (Pinus sylvestris L.) stands in Poland

    International Nuclear Information System (INIS)

    Rudawska, Maria; Leski, Tomasz

    2005-01-01

    The trace metal contents in fruiting bodies of ectomycorrhizal (ECM) fungi, symbiotic partners of Scots pine, were studied on three sites situated in west-central Poland. Elements were determined by atomic absorption spectrometry in 123 samples of 16 species. The study explored the differences in metal accumulation in relation to site, fungal species, age and part of the fruiting body and results were related to metal content in soil and plant material (roots and needles). Soil analysis revealed that results were obtained under environmental conditions not subject to strong anthropogenic pressure. Median metal concentrations did not differ disparately between sites, although the concentrations of each of the tested metals in the individual species varied to a large extent. Extremely high levels of Al with a large bioconcentration factor (BCF) were found in sporocarps of Thelephora terrestris. The spread between the highest and the lowest concentration (max/min) was very wide in Al, Cd and Pb and these elements may be considered to be absorbed preferentially by fruiting bodies of some species whereas Fe, Mn and Zn, with relatively low values of max/min, are normally absorbed by the majority of fungi. There was no clear relationship between caps and stipes in metal content. However, a tendency to higher metal concentration in the caps was observed. The metal content in young and older fruiting bodies of five different fungi was species dependent. In order to estimate the degree of accumulation of each element by plant and mushrooms, bioconcentration factors (BCFs) were calculated. In plant material (roots and needles), highest values of BCFs were noted for essential metals, like Zn and Mn. Lead showed a definite exclusion pattern (BCF below 1). In fruiting bodies of tested fungi, especially in Amanita muscaria, cadmium was the most intensively accumulated metal. Lead was excluded by plants but was accumulated or excluded by fungi depending on the species. The

  11. Effect of mycorrhizal fungi on the phytoextraction of weathered p,p-DDE by Cucurbita pepo.

    Science.gov (United States)

    White, Jason C; Ross, Daniel W; Gent, Martin P N; Eitzer, Brian D; Mattina, Maryjane Incorvia

    2006-10-11

    Field experiments were conducted to assess the impact of inoculation with mycorrhizal fungi on the accumulation of weathered p,p'-DDE from soil by three cultivars of zucchini (Cucurbita pepo spp. pepo cv Costata Romanesco, Goldrush, Raven). Three commercially available mycorrhizal products (BioVam, Myco-Vam, INVAM) were inoculated into the root system of the zucchini seedlings at planting. In agreement with our previous findings, plants not inoculated with fungi accumulated large but variable amounts of contaminant, with root bioconcentration factors (BCFs, ratio of p,p'-DDE, on a dry weight basis, in the root to that in the soil) ranging from 10 to 48 and stem BCFs ranging from 5.5 to 11. The total amount of contaminant phytoextracted during the 62 day growing season ranged from 0.72-2.9%. The effect of fungal inoculation on the release of weathered p,p'-DDE from soil and on the subsequent uptake of the parent compound by zucchini appeared to vary at the cultivar level. For Goldrush, fungal inoculation generally decreased tissue BCFs but because of slightly larger biomass, did not significantly impact the percent contaminant phytoextracted. Alternatively, for Costata, BioVam and Myco-Vam generally enhanced p,p'-DDE accumulation from soil, and increased the amount of contaminant phytoextracted by up to 34%. For Raven, BioVam reduced contaminant uptake whereas Myco-Vam and INVAM increased contaminant phytoextraction by 53 and 60%, respectively. The data show that fungal inoculation may significantly increase the remedial potential of C. pepo ssp. pepo. The apparent cultivar specific response to mycorrhizal inoculation is unexpected and the subject of ongoing investigation.

  12. Effects of soil properties on the uptake of pharmaceuticals into earthworms.

    Science.gov (United States)

    Carter, Laura J; Ryan, Jim J; Boxall, Alistair B A

    2016-06-01

    Pharmaceuticals can enter the soil environment when animal slurries and sewage sludge are applied to land as a fertiliser or during irrigation with contaminated water. These pharmaceuticals may then be taken up by soil organisms possibly resulting in toxic effects and/or exposure of organisms higher up the food chain. This study investigated the influence of soil properties on the uptake and depuration of pharmaceuticals (carbamazepine, diclofenac, fluoxetine and orlistat) in the earthworm Eisenia fetida. The uptake and accumulation of pharmaceuticals into E. fetida changed depending on soil type. Orlistat exhibited the highest pore water based bioconcentration factors (BCFs) and displayed the largest differences between soil types with BCFs ranging between 30.5 and 115.9. For carbamazepine, diclofenac and fluoxetine BCFs ranged between 1.1 and 1.6, 7.0 and 69.6 and 14.1 and 20.4 respectively. Additional analysis demonstrated that in certain treatments the presence of these chemicals in the soil matrices changed the soil pH over time, with a statistically significant pH difference to control samples. The internal pH of E. fetida also changed as a result of incubation in pharmaceutically spiked soil, in comparison to the control earthworms. These results demonstrate that a combination of soil properties and pharmaceutical physico-chemical properties are important in terms of predicting pharmaceutical uptake in terrestrial systems and that pharmaceuticals can modify soil and internal earthworm chemistry which may hold wider implications for risk assessment. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Accumulation of heavy metals in soil-crop systems: a review for wheat and corn.

    Science.gov (United States)

    Wang, Shiyu; Wu, Wenyong; Liu, Fei; Liao, Renkuan; Hu, Yaqi

    2017-06-01

    The health risks arising from heavy metal pollution (HMP) in agricultural soils have attracted global attention, and research on the accumulation of heavy metals in soil-plant systems is the basis for human health risk assessments. This review studied the accumulation of seven typical heavy metals-Cd, Cr, As, Pb, Hg, Cu, and Zn-in soil-corn and soil-wheat systems. The findings indicated that, in general, wheat was more likely to accumulate heavy metals than corn. Bioconcentration factor (BCF) of the seven heavy metals in wheat and corn grains decreased exponentially with their average concentrations in soil. The seven heavy metals were ranked as follows, in ascending order of accumulation in corn grains: Pb < Cr < Zn < As < Cu < Cd BCFs of Cd, Cr, As, Pb, Hg, Cu, and Zn in corn grains were 0.054, 6.65 × 10 -4 , 7.94 × 10 -4 , 0.0044, 0.028, 0.13, and 0.19, respectively. The corresponding BCFs values for wheat grains were 0.25, 0.0045, 5.42 × 10 -4 , 0.009, 4.03 × 10 -4 , 0.11, and 0.054, respectively.

  14. Bioaccumulation of short chain chlorinated paraffins in a typical freshwater food web contaminated by e-waste in south china: Bioaccumulation factors, tissue distribution, and trophic transfer.

    Science.gov (United States)

    Sun, Runxia; Luo, Xiaojun; Tang, Bin; Chen, Laiguo; Liu, Yu; Mai, Bixian

    2017-03-01

    Short chain chlorinated paraffins (SCCPs) are under review for inclusion into the Stockholm Convention on Persistent Organic Pollutants. However, limited information is available on their bioaccumulation and biomagnification in ecosystems, which is hindering evaluation of their ecological and health risks. In the present study, wild aquatic organisms (fish and invertebrates), water, and sediment collected from an enclosed freshwater pond contaminated by electronic waste (e-waste) were analyzed to investigate the bioaccumulation, distribution, and trophic transfer of SCCPs in the aquatic ecosystem. SCCPs were detected in all of the investigated aquatic species at concentrations of 1700-95,000 ng/g lipid weight. The calculated bioaccumulation factors (BAFs) varied from 2.46 to 3.49. The relationship between log BAF and the octanol/water partition coefficient (log K OW ) for benthopelagic omnivorous fish species followed the empirical model of bioconcentration, indicating that bioconcentration plays an important role in accumulation of SCCPs. In contrast, the relationship for the benthic carnivorous fish and invertebrates was not consistent with the empirical model of bioconcentration, implying that the bioaccumulation of SCCPs in these species could be more influenced by other complex factors (e.g., habitat and feeding habit). Preferential distribution in the liver rather than in other tissues (e.g., muscle, gills, skin, and kidneys) was noted for the SCCP congeners with higher log K OW , and bioaccumulation pathway (i.e. water or sediment) can affect the tissue distribution of SCCP congeners. SCCPs underwent trophic dilution in the aquatic food web, and the trophic magnification factor (TMF) values of SCCP congener groups significantly correlated with their corresponding log K OW values (p behavior and fate of SCCPs in aquatic ecosystem. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Toxicokinetics of waterborne trivalent arsenic in the freshwater bivalve Corbicula fluminea.

    Science.gov (United States)

    Costa, Pedro M; Santos, Hugo M; Peres, Isabel; Costa, Maria H; Alves, Sheila; Capelo-Martinez, José Luís; Diniz, Mário S

    2009-08-01

    Arsenite (As(III)) uptake and elimination kinetics were studied in a freshwater bivalve, Corbicula fluminea, exposed to several nominal concentrations of As(III) (0, 100, 300, 500, and 1000 microg L(-1)) in a static 28-day assay, followed by a depuration stage of 14 days. At the end of each sampling time (days 0, 7, 28, and 42) whole-body portions were surveyed for total As concentrations and, complimentarily, surveyed for whole-body metallothionein (MT) induction to assess its role as a defense mechanism against exposure to As(III). Histochemical evaluation of the digestive gland was performed to verify As deposition and elimination in the tissue. Results show a significant increase in whole-body total As after 28 days of exposure for all treatments, followed by a decrease at the end of the depuration phase. Biodynamic kinetic models for As uptake and elimination were obtained from bioaccumulation data during the exposure phase, for all As treatments, by estimating uptake and elimination rate constants. Bioconcentration factors (BCFs) were estimated by the ratio of these constants. Results revealed that exposure to higher concentrations of As(III) causes a decrease in BCFs, suggesting that C. fluminea triggers effective regulatory mechanisms when exposed to higher concentrations of the metalloid. Significant induction of MT was detected during the exposure phase, followed by a decrease in MT concentration to control levels after depuration for all treatments. No significant differences in MT concentrations were observed between treatments. This finding may confirm the role of MT as part of the As regulation process, but its independence relative to concentrations of As(III) in water suggests that MT induction is not dose dependent. The histochemical evaluation provided clear evidence that As was effectively accumulated in the digestive gland during exposure and eliminated during depuration. The present work demonstrated that C. fluminea is capable of regulating As

  16. Pesticide Uptake Across the Amphibian Dermis Through Soil and Overspray Exposures.

    Science.gov (United States)

    Van Meter, Robin J; Glinski, Donna A; Henderson, W Matthew; Garrison, A Wayne; Cyterski, Mike; Purucker, S Thomas

    2015-11-01

    For terrestrial amphibians, accumulation of pesticides through dermal contact is a primary route of exposure in agricultural landscapes and may be contributing to widespread amphibian declines. To show pesticide transfer across the amphibian dermis at permitted label application rates, our study was designed to measure pesticide body burdens after two simulated exposure scenarios. We compared direct exposures, where amphibians were present when spraying occurred, to indirect exposures, where amphibians were exposed to soils after pesticide application. During summer 2012, we reared barking (Hyla gratiosa) and green treefrogs (H. cinerea) through 60-90 days post-metamorphosis at a United States Environmental Protection Agency research laboratory. We tested exposure for 8 h to five pesticide active ingredients (imidacloprid, atrazine, triadimefon, fipronil, or pendimethalin) in glass aquaria lined with soil in the laboratory. We quantified total pesticide body burden and soil concentrations using liquid chromatography-mass spectrometry. All individuals in both treatments had measurable body burdens at the end of the study. A randomized block design analysis of variance (n = 18) showed that body burdens (p = 0.03) and bioconcentration factors (BCFs) (p = 0.01) were significantly greater in the direct overspray treatment relative to the indirect soil spray treatment for both species and tested pesticides. BCFs ranged from 0.1 to 1.16 and from 0.013 to 0.78 in the direct and indirect treatments, respectively. Our study shows dermal uptake for multiple pesticides from both direct spray and indirect soil exposures and provides empirical support for the degree to which terrestrial phase amphibians have higher body burdens after overspray pesticide exposure.

  17. The presence and distribution of polycyclic aromatic hydrocarbons and inorganic elements in water and lakebed materials and the potential for bioconcentration in biota at established sampling sites on Lake Powell, Utah and Arizona

    Science.gov (United States)

    Schonauer, Kurt T.; Hart, Robert J.; Antweiler, Ronald C.

    2014-01-01

    The National Park Service is responsible for monitoring the effects of visitor use on the quality of water, lakebed material (bottom sediments), and biota, in Lake Powell, Utah and Arizona. A sampling program was begun in 2010 to assess the presence, distribution, and concentrations of organic and inorganic compounds in the water column and bottom sediment. In response to an Environmental Impact Statement regarding personal watercraft and as a continuation from previous studies by the U.S. Geological Survey and the National Park Service, Glen Canyon National Recreation Area, water samples were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) using semipermeable membrane devices and inorganic elements using a fixed-bottle sampler deployed at established monitoring sites during 2010 and 2011. Lakebed material samples were also analyzed for polycyclic aromatic hydrocarbons and inorganic elements, some of which could be harmful to aquatic biota if present at concentrations above established aquatic life criteria. Of the 44 PAH compounds analyzed, 26 individual compounds were detected above the censoring limit in the water column by semipermeable membrane devices. The highest number of compounds detected were at Lone Rock Beach, Wahweap Marina, Rainbow Bridge National Monument, and Antelope Marina which are all located in the southern part of Lake Powell where visitation and boat use is high. Because PAHs can remain near their source, the potential for bioconcentration is highest near these sites. The PAH compound found in the highest concentration was phenol (5,902 nanograms per liter), which is included in the U.S. Environmental Protection Agency’s priority pollutants list. The dissolved inorganic chemistry of water samples measured at the sampling sites in Lake Powell defined three different patterns of elements: (1) concentrations were similar between sites in the upper part of the lake near Farley Canyon downstream to Halls Crossing Marina, a

  18. Mutual impacts of wheat (Triticum aestivum L.) and earthworms (Eisenia fetida) on the bioavailability of perfluoroalkyl substances (PFASs) in soil

    International Nuclear Information System (INIS)

    Zhao, Shuyan; Fang, Shuhong; Zhu, Lingyan; Liu, Li; Liu, Zhengtao; Zhang, Yahui

    2014-01-01

    Wheat and earthworms were exposed individually and together to soils contaminated with 11 perfluoroalkyl substances (PFASs). Wheat accumulated PFASs from soil with root concentration factors and bioconcentration factors that decreased as the number of perfluorinated carbons in the molecule increased. Earthworms accumulated PFASs from soil with biota-to-soil accumulation factors that increased with the number of carbons. Translocation factors (TF) of perfluorinated carboxylates (PFCAs) in wheat peaked at perfluorohexanoic acid and decreased significantly as the number of carbons increased or decreased. Perfluorohexane sulfonate produced the greatest TF of the three perfluorinated sulfonates (PFSAs) examined. Wheat increased the bioaccumulation of all 11 PFASs in earthworms and earthworms increased the bioaccumulation in wheat of PFCAs containing seven or less perfluorinated carbons, decreased bioaccumulation of PFCAs with more than seven carbons, and decreased bioaccumulation of PFSAs. In general, the co-presence of wheat and earthworms enhanced the bioavailability of PFASs in soil. -- Highlights: • PFASs can be taken up by root of wheat from soil and translocated to shoot. • The RCFs and BCFs of PFASs in wheat decreased with perfluorinated carbon chain length. • PFHxA had the highest TF, which decreased exponentially with the carbon chain length. • The BSAFs in earthworm increased with carbon chain length. • The co-presence of wheat and earthworm enhanced the bioavailability of PFASs in soil. -- PFASs can be uptake by root of wheat from soil and translocated to shoot and co-presence of wheat and earthworm enhance the bioavailability of PFASs in soil

  19. Translocation of metal ions from soil to tobacco roots and their concentration in the plant parts.

    Science.gov (United States)

    da Silva, Cleber Pinto; de Almeida, Thiago E; Zittel, Rosimara; de Oliveira Stremel, Tatiana R; Domingues, Cinthia E; Kordiak, Januário; de Campos, Sandro Xavier

    2016-12-01

    This paper presents a study on the translocation factors (TFs) and bioconcentration factors (BCFs) of copper (Cu), manganese (Mn), zinc (Zn), cobalt (Co), chromium (Cr), cadmium (Cd), lead (Pb), iron (Fe), nickel (Ni), and arsenic (As) ions in roots, stems, and leaves of tobacco. The results revealed that during the tobacco growth, the roots are able to increase the sensitiveness of the physiological control, reducing the translocation of the metals Ni (0.38) and Pb (0.48) to the leaves. Cd and Zn presented factors TF and BCF >1 in the three tissues under analysis, which indicates the high potential for transportation and accumulation of these metals in all plant tissues. The TF values for Cr (0.65) and As (0.63) revealed low translocation of these ions to the aerial parts, indicating low mobility of ions from the roots. Therefore, tobacco can be considered an efficient accumulator of Ni, Cr, As and Pb in roots and Cd and Zn in all plant parts.

  20. Toxicokinetic of benzo[a]pyrene and fipronil in female green frogs (Pelophylax kl. esculentus)

    International Nuclear Information System (INIS)

    Reynaud, Stéphane; Worms, Isabelle A.M.; Veyrenc, Sylvie; Portier, Julien; Maitre, Anne

    2012-01-01

    A general consensus that an increased logK ow led to an increase in xenobiotic uptake and bioaccumulation is accepted. In this study we compared the toxicokinetics of two chemically different xenobiotics, i.e. benzo[a]pyrene and fipronil in female green frogs. Surprisingly, the uptake rates and the bioconcentration factors (BCF) of the two contaminants were not predicted by their logK ow . The uptake rates obtained were of the same order of magnitude for the two contaminants and the BCFs measured for fipronil were about 3-fold higher than those obtained for benzo[a]pyrene. Fipronil appeared to be more recalcitrant than benzo[a]pyrene to detoxification processes leading to the accumulation of sulfone-fipronil especially in the ovaries. This phenomenon may explain reproductive influence of this contaminant described in other studies. Detoxification processes, including metabolism and the excretion of pollutants, are of importance when considering their persistence in aquatic organisms and trying to quantify their risks. Highlights: ► The uptake of benzo[a]pyrene is 1.5–3 times higher than for fipronil. ► Fipronil was more recalcitrant than benzo[a]pyrene to detoxification processes. ► This lead to increased-bioaccumulation factors except in excretion organs. ► Amphibians can be used as biomonitors for persistent pollutants. - Fipronil is more recalcitrant than benzo[a]pyrene to detoxification processes in frog.

  1. Evidence of lead biomagnification in invertebrate predators from laboratory and field experiments

    Energy Technology Data Exchange (ETDEWEB)

    Rubio-Franchini, Isidoro [Departamento de Quimica, Centro de Ciencias Basicas, Universidad Autonoma de Aguascalientes, Avenida Universidad 940, CP 20131 Aguascalientes (Mexico); Rico-Martinez, Roberto, E-mail: rrico@correo.uaa.mx [Departamento de Quimica, Centro de Ciencias Basicas, Universidad Autonoma de Aguascalientes, Avenida Universidad 940, CP 20131 Aguascalientes (Mexico)

    2011-07-15

    This report includes atomic absorption data from water column, elutriates and zooplankton that demonstrate that lead biomagnifies at El Niagara reservoir, Mexico. Results include field data (bioaccumulation factors) (BAFs) and laboratory data (bioconcentration factors) (BCFs). Two findings: high BAFs for invertebrate predator like Acanthocyclops robustus, Asplanchna brightwellii, Culex sp. larvae, and Hyalella azteca, compared to grazer species Moina micrura and Simocephalus vetulus; low BCF's found for some predators, suggested that lead biomagnifications were taking place. The presence of Moina micrura in the gut of Asplanchna allowed us to design experiments where A. brightwellii was fed lead-exposed M. micrura neonates. The BAF of Asplanchna was 123,684, BCF was 490. Asplanchna individuals fed exposed Moina had 13.31 times more lead than Asplanchna individuals just exposed 48-h to lead, confirming that lead biomagnification occurs. Results of two fish species showed no lead biomagnification, suggesting that lead biomagnification might be restricted to invertebrate predators. - Highlights: > Study shows lead biomagnification evidence in reservoirs where top predators are invertebrates. > Study discusses why in previous studies lead biomagnifications were not detected. > Evidence of biomagnification comes from field and laboratory studies. - This study shows evidence (from field and laboratory experiments) of lead biomagnification in a freshwater reservoir where the main predators are invertebrates.

  2. Evaluation of the potential for trophic transfer of roxithromycin along an experimental food chain.

    Science.gov (United States)

    Ding, Jiannan; Lu, Guanghua; Liu, Jianchao; Zhang, Zhenghua

    2015-07-01

    Pharmaceuticals have been recognized as a new class of environmental pollutants in recent years. But data about their potential for transfer and biomagnification in aquatic food chains are still lacking. In this study, bioaccumulation of the macrolide antibiotic roxithromycin (ROX) was determined in an experimental aquatic food chain involving the green algae Scenedesmus obliquus, the water flea Daphnia magna and the crucian carp Carassius auratus. After 48 h of exposure, S. obliquus accumulated ROX from media, with bioconcentration factors (BCFs) of 74.6, 46.3, and 24.5 l kg(-1) at nominal exposure concentrations of 4, 20, and 100 μg l(-1), respectively. After 48 h of feeding ROX-contaminated algae, D. magna was able to accumulate ROX in all three concentration treatments, but biomagnification did not occur at this trophic level, as biomagnification factors (BMFs) varied from 0.21 to 0.29 in different concentration treatments were well below one. In tissues (muscle, gill, liver, and bile) of C. auratus fed with contaminated daphnia for 8 days, no biomagnification was observed. However, this species did accumulate a certain degree of ROX through food chain transfer, and the tissue burden was greatest in the liver > muscle > gill and lowest in the bile. This work suggests that the trophic transfer should be a matter of concern for ecological risk assessments of pharmaceutical substances in aquatic food webs.

  3. Soil-plant transfer models for metals to improve soil screening value guidelines valid for São Paulo, Brazil.

    Science.gov (United States)

    Dos Santos-Araujo, Sabrina N; Swartjes, Frank A; Versluijs, Kees W; Moreno, Fabio Netto; Alleoni, Luís R F

    2017-11-07

    In Brazil, there is a lack of combined soil-plant data attempting to explain the influence of specific climate, soil conditions, and crop management on heavy metal uptake and accumulation by plants. As a consequence, soil-plant relationships to be used in risk assessments or for derivation of soil screening values are not available. Our objective in this study was to develop empirical soil-plant models for Cd, Cu, Pb, Ni, and Zn, in order to derive appropriate soil screening values representative of humid tropical regions such as the state of São Paulo (SP), Brazil. Soil and plant samples from 25 vegetable species in the production areas of SP were collected. The concentrations of metals found in these soil samples were relatively low. Therefore, data from temperate regions were included in our study. The soil-plant relations derived had a good performance for SP conditions for 8 out of 10 combinations of metal and vegetable species. The bioconcentration factor (BCF) values for Cd, Cu, Ni, Pb, and Zn in lettuce and for Cd, Cu, Pb, and Zn in carrot were determined under three exposure scenarios at pH 5 and 6. The application of soil-plant models and the BCFs proposed in this study can be an important tool to derive national soil quality criteria. However, this methodological approach includes data assessed under different climatic conditions and soil types and need to be carefully considered.

  4. Locomotor behavioral response of mosquitofish (Gambusia affinis) to subacute mercury stress monitored by video tracking system.

    Science.gov (United States)

    Jakka, N M; Rao, T Gnaneshwar; Rao, J Venkateswara

    2007-01-01

    Locomotor behavior is commonly affected by contaminants, and the pattern of fish swimming is a highly organized species-specific response. In the current study, we examined the locomotor behavioral response of the mosquitofish, Gambusia affinis, which was exposed to a sublethal concentration (LC(5), 20 microg/L) of mercuric chloride (HgCl2) for 28 days and monitored using a computer vision system. The EthoVision video tracking system for automation of behavioral studies at regular intervals revealed abnormal locomotor behavior such as reduction in swimming speed (cm/s) and distance traveled per unit time. The effects of this metal on the gill morphology and bioaccumulation in different body parts were also investigated. High-resolution microscopy studies revealed abnormal gill morphology, with fusion of primary lamellae along with deep lesions and erosions in the secondary lamellae. The bioaccumulation concentrations in head, body, and viscera were determined by cold vapor atomic absorption spectrometric technique at regular intervals. The results indicated that the accumulation of mercury was the highest in viscera followed by head and body, with bioconcentration factors (BCFs) of 3.99, 2.18, and 1.57 and uptake rate constants (k1) of 17.91, 11.02, and 8.13, respectively. These observations indicate that alterations in fish behavior under subacute stress can provide important information useful in predicting the stress.

  5. Evaluation of the cadmium and lead phytoextraction by castor bean (Ricinus communis L.) in hydroponics

    Science.gov (United States)

    Niu, Z. X.; Sun, L. N.

    2017-06-01

    Phytoextraction has been considered as an innovative method to remove toxic metals from soil; higher biomass plants such as castor bean (Ricinus communis L.) have already been considered as a hyperaccumulating candidate. In the present study, castor bean was used to accumulate the cadmium and lead in hydroponic culture, and the root exudates and biomass changes were analyzed. Results demonstrated that ratios of aerial biomass/ root biomass (AW/RW) in treatments declined with concentrations of Cd or Pb. Optical density (OD) at 190 nm and 280 nm of root exudates observed in Cd and Pb treatments were lower than the control. In single Cd or Pb treatments, bioconcentration factors (BCF) of Cd or Pb increased with time and decreased with concentrations, the highest BCFs appeared in Cd5 (14.36) and Pb50 (6.48), respectively. Cd-BCF or Pb-BCF showed positive correlations with AW/RW ratios and OD values, and they were negative correlated with Cd and Pb concentration. Results in this study may supply useful information for phytoremediation of soil contaminated with cadmium and lead in situ.

  6. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe; Sandberg, Johannes (DHI, Hoersholm (Denmark))

    2010-06-15

    quasi-stationary equilibrium within the model area. The coupled ecosystem and radionuclide models were used to simulate present conditions, i.e. 2020 AD. Six radionuclides were modelled explicitly in addition to C-14. They represent a wide range of accumulation potentials and partition coefficients (K{sub d}, distribution of radionuclides between water, sediment and biota). The ecosystem and associated radionuclide model include a detailed sediment module where radionuclides can be bound by adsorption to the organic and inorganic fractions, be precipitated, be transported by resuspension and later deposited at larger depths. With the exception of radionuclides with very low particle affinity, such as Cl-35, the majority of radionuclides released in basins where they were introduced via groundwater flow remained in the sediments even after a simulation period of eight years. The spread of radionuclides with high partition coefficients for sediments from areas with groundwater flow takes place by sediment resuspension and subsequent transport and sedimentation. In the case of radionuclides with lower partition coefficients, release from the sediments to the water column followed by transport of dissolved radionuclides by currents plays a larger role. A significant result of the modelling was the quantification of the seasonal and spatial variation in radionuclide accumulation and in bioconcentration factors (BCFs) with spatial variation of BCFs often ranging 2 to 3 orders of magnitude. This variation was dominated by spatial differences in concentrations of radionuclides in water. In basins where radionuclides were introduced by groundwater flow, BCFs were typically 2-3 orders of magnitude lower than in deep basins without radionuclide release in the groundwater. In phytoplankton and grazers, bioconcentration factors (BCFs) scaled linearly to partition coefficients (Kd), underlining the fact that adsorption is an important process for radionuclide accumulation in the

  7. Mercury bioaccumulation and bioaccumulation factors for Everglades mosquitofish as related to sulfate: a re-analysis of Julian II (2013).

    Science.gov (United States)

    Pollman, Curtis D; Axelrad, Donald M

    2014-11-01

    The Everglades, an ecosystem of international significance, has elevated biota mercury levels representing risk to human and wildlife consumers of fish. Given the critical role of sulfate in the methylation of mercury, and because there is a significant agricultural contribution, one potential means of reducing these mercury levels is reducing Everglades sulfate inputs. Julian II (Bull Environ Contam Toxicol 90:329-332, 2013) conducted regression modeling of the relationship between surface water sulfate concentrations and Gambusia spp. mercury bioconcentration factors across the major hydrologic subunits of the Everglades, and used those results to draw conclusions about the role of sulfate in the cycling of mercury in the Everglades. We however demonstrate a number of fundamental problems with the analysis, interpretation and conclusions. As a result, we strongly caution against using the results of Julian II (Bull Environ Contam Toxicol 90:329-332, 2013) to formulate management decisions regarding mitigation of the Everglades mercury problem.

  8. Concentration factors of radionuclides in the marine organisms

    International Nuclear Information System (INIS)

    1996-03-01

    Parameters related to the bioconcentration of radionuclides in the marine were shown by 'Assessment and guideline to the target value of dose in the environment of the power light water reactor facilities' (Nuclear Safety Commission), but the guideline data did not contain Ru and Ce relating to the reprocessing plant. So that more new data than these of 'Technical Reports Series No. 247' (published by IAEA in 1985) were mainly collected. Especially the data of nuclides with poor data of concentration factors (CF) and natural radionuclides (Po-210, Pb-210) were gathered. These data were pigeonholed and many tables (element, kinds of organisms, experimental methods) were made by separating the general remarks from the original experimental reports. The contents of this report are given as under, history of concentration factor (CF), determination method of CF, CF calculation method, calculation models related to CF, tables of metabolic parameters, tables of CF, the present conditions of studies for uptake of radionuclides with long half-life into the marine organisms, CF abstract tables and trial calculation of human exposure by eating the marine organisms. (S.Y.)

  9. Bioaccumulation factor of 137Cs in some marine biotas from West Bangka Indonesia

    International Nuclear Information System (INIS)

    Suseno, Heny

    2014-01-01

    Radionuclides may be released from nuclear facilities to the marine environment. Concentrations of radionuclides within marine biotic systems can be influenced by a number of factors, including the type of biota, its source, the radionuclide, and specific characteristics of the sampled specimens and the marine environment (salinity, etc.). The bioconcentration factor for a marine organism is the ratio of the concentration of a radionuclide in that organism to the concentration found in its marine water environment - under conditions of equilibrium. Information on the bioaccumulation of Cs-137 in marine organisms is required to risk assessment evaluates the potential risks to human health. Bioaccumulation of Cs was investigated in marine biota from west Bangka such as Marine cat fish (Arius thalassinus), Baramundi (Lates calcarifer), Mackerel (Scomberomorus commerson), Striped eel catfish (Plotosus lineatus), eel tailed fish (Euristhmus microceps), Yellowtail fusilier (Caesio erythrogaster), Coastal crab (Scylla sp), White shrimp (Penaeus merguiensis) and marine bivalve mollusk (Anadara granosa). Muscle of these marine biota, sediments and water were assayed for Cs-137 by HPGe gamma spectrometer. The bioaccumulation factor for fishes were calculated by ratio of concentration Cs-137 in muscle biota to the its concentration in water. The bioaccumulation factor for mollusks were calculates by ratio of concentration Cs-137 in muscle biota to the its concentration in sediments. The bioaccumulation factor were range 4.99 to 136.34

  10. Bioaccumulation factor of 137Cs in some marine biotas from West Bangka Indonesia

    Science.gov (United States)

    Suseno, Heny

    2014-03-01

    Radionuclides may be released from nuclear facilities to the marine environment. Concentrations of radionuclides within marine biotic systems can be influenced by a number of factors, including the type of biota, its source, the radionuclide, and specific characteristics of the sampled specimens and the marine environment (salinity, etc.). The bioconcentration factor for a marine organism is the ratio of the concentration of a radionuclide in that organism to the concentration found in its marine water environment - under conditions of equilibrium. Information on the bioaccumulation of Cs-137 in marine organisms is required to risk assessment evaluates the potential risks to human health. Bioaccumulation of Cs was investigated in marine biota from west Bangka such as Marine cat fish (Arius thalassinus), Baramundi (Lates calcarifer), Mackerel (Scomberomorus commerson), Striped eel catfish (Plotosus lineatus), eel tailed fish (Euristhmus microceps), Yellowtail fusilier (Caesio erythrogaster), Coastal crab (Scylla sp), White shrimp (Penaeus merguiensis) and marine bivalve mollusk (Anadara granosa). Muscle of these marine biota, sediments and water were assayed for Cs-137 by HPGe gamma spectrometer. The bioaccumulation factor for fishes were calculated by ratio of concentration Cs-137 in muscle biota to the its concentration in water. The bioaccumulation factor for mollusks were calculates by ratio of concentration Cs-137 in muscle biota to the its concentration in sediments. The bioaccumulation factor were range 4.99 to 136.34.

  11. Bioaccumulation factor of {sup 137}Cs in some marine biotas from West Bangka Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Suseno, Heny, E-mail: henis@batan.go.id [Radioactive Waste Technology Center - The Indonesia Nuclear Energy Agency (BATAN) (Indonesia)

    2014-03-24

    Radionuclides may be released from nuclear facilities to the marine environment. Concentrations of radionuclides within marine biotic systems can be influenced by a number of factors, including the type of biota, its source, the radionuclide, and specific characteristics of the sampled specimens and the marine environment (salinity, etc.). The bioconcentration factor for a marine organism is the ratio of the concentration of a radionuclide in that organism to the concentration found in its marine water environment - under conditions of equilibrium. Information on the bioaccumulation of Cs-137 in marine organisms is required to risk assessment evaluates the potential risks to human health. Bioaccumulation of Cs was investigated in marine biota from west Bangka such as Marine cat fish (Arius thalassinus), Baramundi (Lates calcarifer), Mackerel (Scomberomorus commerson), Striped eel catfish (Plotosus lineatus), eel tailed fish (Euristhmus microceps), Yellowtail fusilier (Caesio erythrogaster), Coastal crab (Scylla sp), White shrimp (Penaeus merguiensis) and marine bivalve mollusk (Anadara granosa). Muscle of these marine biota, sediments and water were assayed for Cs-137 by HPGe gamma spectrometer. The bioaccumulation factor for fishes were calculated by ratio of concentration Cs-137 in muscle biota to the its concentration in water. The bioaccumulation factor for mollusks were calculates by ratio of concentration Cs-137 in muscle biota to the its concentration in sediments. The bioaccumulation factor were range 4.99 to 136.34.

  12. Can an aquatic macrophyte bioaccumulate glyphosate? A watershed scale study using a non-target hydrophyte Ludwigia peploides

    Science.gov (United States)

    Perez, Debora; Okada, Elena; Menone, Mirta; Aparicio, Virginia; Costa, Jose Luis

    2017-04-01

    The hydrophyte Ludwigia peploides is widely distributed in South America streams, and therefore, it can be used as a biomonitor for pesticides used in agricultural production. Glyphosate is one of the main pesticides used in Argentina. This has resulted in its occurrence in non-target wetland ecosystems. The objectives of this study were to: 1) establish and validate an extraction and quantification methodology for glyphosate in L.peploides plants, and 2) evaluated the role of this species as a glyphosate biomonitor in the agricultural watershed of the El Crespo stream. For the first objective, we collected plant material in the field. The leaves were dissected and oven dried at 60° C, grinded and sieved through a 0.5 mm mesh. Different solutions were tested for the extraction step. Labeled glyphosate was used as an internal standard to evaluate the recovery rate and the matrix effect of the different extraction methods. Glyphosate was derivatized with FMOC-Cl and then quantified by ultra-performance liquid chromatography (UPLC) coupled to a mass tandem spectrometer (MS/MS). The method based on an aqueous phase extraction step 0.01 mg/mL of activated carbon as a clean-up to decrease the matrix interference had a recovery of 117 ± 20% and the matrix effect was less than 20%. This method was used to analyze the glyphosate levels in L.peploides in the El Crespo stream. For the second objective, plants of L.peploides were collected on March 2016 in eight monitoring sites of the stream from the headwaters to the stream mouth. Surface water and sediments samples were collected at the same time to calculate the bioconcentration factors (BCFs) and biota-sediment bioaccumulation factors (BSAFs). The BCFs ranged between 28.57 - 280 L/Kg and the BSAFs ranged between 2.52- 30.66 at different sites. These results indicate that L.peploides can bioaccumulated glyphosate in its leaves and the major bioavailability is given mainly by the herbicide molecules present in surface

  13. Bioconcentration of elements by Poison pax (Paxillus involutus)

    African Journals Online (AJOL)

    Jerzy Falandysz

    2012-03-08

    Mar 8, 2012 ... brand new polyethylene bags and kept in dry and clean condition. Reagents. All reagents were of analytical reagent grade unless otherwise. Jarzyńska and Falandysz 4589 stated. Double distilled water (resistivity > 10 MΩ cm) was used for the preparation of solutions. The nitric acid (65% HNO3) was of.

  14. The Bioconcentration Hypothesis: Potential Role of Transporter in Breast Ductules

    National Research Council Canada - National Science Library

    Karnaky, Karl

    2002-01-01

    .... MRP2 is located at the apical membrane of epithelial cells and excretes anionic hydrophobic substrates, such as 17 beta-estrogen glucuronide, antioxidants, and toxic molecules into lumen of the kidney, liver, and gut...

  15. Trace Elements in Dominant Species of the Fenghe River, China: Their Relations to Environmental Factors.

    Science.gov (United States)

    Yang, Yang; Zhou, Zhengchao; Bai, Yanying; Jiao, Wentao; Chen, Weiping

    2016-07-01

    The distribution of trace elements (TEs) in water, sediment, riparian soil and dominant plants was investigated in the Fenghe River, Northwestern China. The Fenghe River ecosystem was polluted with Cd, Cr, Hg and Pb. There was a high pollution risk in the midstream and downstream regions and the risk level for Cd was much higher than that of the other elements. The average values of bioconcentration coefficient for Cd and Zn were 2.21 and 1.75, respectively, indicating a large accumulation of Cd and Zn in the studied species. With broad ecological amplitudes, L. Levl. et Vant. Trin., and L. had the greatest TE concentrations in aboveground and belowground biomass of the studied species and were potential biomonitors or phytoremediators for the study area. Multivariate techniques including cluster analysis, correlation analysis, principal component analysis, and canonical correspondence analysis were used to analyze the relations between TE concentrations in plants and various environmental factors. The soil element concentration is the main factor determining the accumulation of TEs in plants. The co-release behavior of common pollutants and TEs drove the accumulation of Hg, Cd, and As in the studied plants. Significant enrichment of some elements in the Fenghe River has led to a decline in the biodiversity of plants. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. Organochlorine pollution in tropical rivers (Guadeloupe): Role of ecological factors in food web bioaccumulation

    Energy Technology Data Exchange (ETDEWEB)

    Coat, Sophie, E-mail: coatsophie@gmail.com [EA 926 DYNECAR, Laboratoire de Biologie Marine, UFR Sciences, Universite des Antilles et de la Guyane, BP592, 97159 Pointe-a-Pitre Cedex (France); Monti, Dominique, E-mail: dominique.monti@univ-ag.fr [EA 926 DYNECAR, Laboratoire de Biologie Marine, UFR Sciences, Universite des Antilles et de la Guyane, BP592, 97159 Pointe-a-Pitre Cedex (France); Legendre, Pierre, E-mail: pierre.legendre@umontreal.ca [Departement de Sciences Biologique, Universite de Montreal, C.P. 6128, succursale A, Montreal, Quebec H3C 3J7 (Canada); Bouchon, Claude, E-mail: claude.bouchon@univ-ag.fr [EA 926 DYNECAR, Laboratoire de Biologie Marine, UFR Sciences, Universite des Antilles et de la Guyane, BP592, 97159 Pointe-a-Pitre Cedex (France); Massat, Felix, E-mail: fmassat@ladrome.fr [LDA26, laboratoire Departemental d' Analyses de la Drome, 27 avenue Lautagne, 26000 Valence (France); Lepoint, Gilles, E-mail: g.lepoint@ulg.ac.be [MARE Centre, Laboratoire d' Oceanologie, Universite de Liege, Bat. B6, 4000 Sart Tilman, Belgique (Belgium)

    2011-06-15

    Concentrations of organochlorine pesticides and stable isotope ratios of nitrogen and carbon were measured in a tropical freshwater ecosystem to evaluate the contamination level of biota and examine the bioaccumulation patterns of pollutants through the food web. Chemical analyses showed a general and heavy contamination of the entire food web. They revealed the strong accumulation of pollutants by juveniles of diadromous fishes and shrimps, as they re-enter the river. The role of ecological factors in the bioaccumulation of pesticides was evaluated. Whereas the most persistent pollutants (chlordecone and monohydro-chlordecone) were related to the organisms diet and habitat, bioaccumulation of {beta}-HCH was only influenced by animal lipid content. The biomagnification potential of chlordecone through the food chain has been demonstrated. It highlighted the importance of trophic transfer in this compound bioaccumulation process. In contrast, bioconcentration by passive diffusion from water seemed to be the main exposure route of biota to {beta}-HCH. - Highlights: > We measured OC pesticides and stable isotope ratios in a tropical stream. > Results showed a strong and ubiquitous contamination of the entire food web. > Diadromous juveniles strongly accumulated pollutants when they re-enter the river. > The most persistent pollutant (chlordecone) was related to species diet and habitat. > {beta}-HCH was only influenced by animal lipid content. - This paper determines the bioaccumulation and transfer processes of organochlorine pesticides within the stream food web in Guadeloupe (Caribbean).

  17. Organochlorine pollution in tropical rivers (Guadeloupe): role of ecological factors in food web bioaccumulation.

    Science.gov (United States)

    Coat, Sophie; Monti, Dominique; Legendre, Pierre; Bouchon, Claude; Massat, Félix; Lepoint, Gilles

    2011-06-01

    Concentrations of organochlorine pesticides and stable isotope ratios of nitrogen and carbon were measured in a tropical freshwater ecosystem to evaluate the contamination level of biota and examine the bioaccumulation patterns of pollutants through the food web. Chemical analyses showed a general and heavy contamination of the entire food web. They revealed the strong accumulation of pollutants by juveniles of diadromous fishes and shrimps, as they re-enter the river. The role of ecological factors in the bioaccumulation of pesticides was evaluated. Whereas the most persistent pollutants (chlordecone and monohydro-chlordecone) were related to the organisms diet and habitat, bioaccumulation of β-HCH was only influenced by animal lipid content. The biomagnification potential of chlordecone through the food chain has been demonstrated. It highlighted the importance of trophic transfer in this compound bioaccumulation process. In contrast, bioconcentration by passive diffusion from water seemed to be the main exposure route of biota to β-HCH. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Perfluorinated alkyl substances in water, sediment, plankton and fish from Korean rivers and lakes: a nationwide survey.

    Science.gov (United States)

    Lam, Nguyen-Hoang; Cho, Chon-Rae; Lee, Jung-Sick; Soh, Ho-Young; Lee, Byoung-Cheun; Lee, Jae-An; Tatarozako, Norihisa; Sasaki, Kazuaki; Saito, Norimitsu; Iwabuchi, Katsumi; Kannan, Kurunthachalam; Cho, Hyeon-Seo

    2014-09-01

    Water, sediment, plankton, and blood and liver tissues of crucian carp (Carassius auratus) and mandarin fish (Siniperca scherzeri) were collected from six major rivers and lakes in South Korea (including Namhan River, Bukhan River, Nakdong River, Nam River, Yeongsan River and Sangsa Lake) and analyzed for perfluorinated alkyl substances (PFASs). Perfluorooctane sulfonate (PFOS) was consistently detected at the greatest concentrations in all media surveyed with the maximum concentration in water of 15 ng L(-1) and in biota of 234 ng mL(-1) (fish blood). A general ascending order of PFAS concentration of waterPFAS concentrations in water samples were below 10 ng L(-1). The PFOS and perfluorooctanoic acid (PFOA) concentrations in water did not exceed levels for acute and/or chronic effects in aquatic organisms. High concentrations of long chain perfluorocarboxylates (LCPFCAs) were found in sediment samples. PFOS, perfluoroundecanoic acid (PFUnA), perfluorododecanoic acid (PFDoA) and perfluorodecanoic acid (PFDA) accounted for 94-99% of the total PFASs concentration in fish tissues. The mean ratios of PFAS concentration between fish blood and fish liver were above 2 suggesting higher levels in blood than in liver. Significant positive correlations (r>0.80, p<0.001) were observed between PFOS concentration in blood and liver tissues of both crucian carp and mandarin fish. This result suggests that blood can be used for nonlethal monitoring of PFOS in fish. Overall, the rank order of mean bioconcentration factors (BCFs) of PFOS in biota was; phytoplankton (196 L/kg)

  19. Phthalate esters contamination in soil and plants on agricultural land near an electronic waste recycling site.

    Science.gov (United States)

    Ma, Ting Ting; Christie, Peter; Luo, Yong Ming; Teng, Ying

    2013-08-01

    The accumulation of phthalic acid esters (PAEs) in soil and plants in agricultural land near an electronic waste recycling site in east China has become a great threat to the neighboring environmental quality and human health. Soil and plant samples collected from land under different utilization, including fallow plots, vegetable plots, plots with alfalfa (Medicago sativa L.) as green manure, fallow plots under long-term flooding and fallow plots under alternating wet and dry periods, together with plant samples from relative plots were analyzed for six PAE compounds nominated as prior pollutants by USEPA. In the determined samples, the concentrations of six target PAE pollutants ranged from 0.31-2.39 mg/kg in soil to 1.81-5.77 mg/kg in various plants (dry weight/DW), and their bioconcentration factors (BCFs) ranged from 5.8 to 17.9. Health risk assessments were conducted on target PAEs, known as typical environmental estrogen analogs, based on their accumulation in the edible parts of vegetables. Preliminary risk assessment to human health from soil and daily vegetable intake indicated that DEHP may present a high-exposure risk on all ages of the population in the area by soil ingestion or vegetable consumption. The potential damage that the target PAE compounds may pose to human health should be taken into account in further comprehensive risk assessments in e-waste recycling sites areas. Moreover, alfalfa removed substantial amounts of PAEs from the soil, and its use can be considered a good strategy for in situ remediation of PAEs.

  20. Disposal of dredged sediments in tropical soils: ecotoxicological effects on earthworms.

    Science.gov (United States)

    Cesar, Ricardo; Natal-da-Luz, Tiago; Sousa, José Paulo; Colonese, Juan; Bidone, Edison; Castilhos, Zuleica; Egler, Silvia; Polivanov, Helena

    2014-03-01

    The upper limit concentrations of metals established by international legislations for dredged sediment disposal and soil quality do not take into consideration the properties of tropical soils (generally submitted to more intense weathering processes) on metal availability and ecotoxicity. Aiming to perform an evaluation on the suitability of these threshold values in tropical regions, the ecotoxicity of metal-contaminated dredged sediment from the Guanabara Bay (Rio de Janeiro, Brazil) was investigated. Acute and avoidance tests with Eisenia andrei were performed with mixtures of dredged sediment with a ferralsol (0.00, 6.66, 13.12, 19.98, and 33.30 %) and a chernosol (0.00, 6.58, 13.16, 19.74, and 32.90 %). Mercury, lead, nickel, chromium, copper, and zinc concentrations were measured in test mixtures and in tissues of surviving earthworms from the acute tests. While ferralsol test mixtures provoked significant earthworm avoidance response at concentrations ≥13.31 %, the chernosol mixtures showed significant avoidance behavior only at the 19.74 % concentration. The acute tests showed higher toxicity in ferralsol mixtures (LC50 = 9.9 %) compared to chernosol mixtures (LC50 = 16.5 %), and biomass increased at the lowest sediment doses in treatments of both test soils. Most probably, the expansive clay minerals present in chernosol contributed to reduce metal availability in chernosol mixtures, and consequently, the ecotoxicity of these treatments. The bioconcentration factors (BCF) for zinc and copper were lower with increasing concentrations of the dredged sediment, indicating the existence of internal regulating processes. Although the BCF for mercury also decreased with the increasing test concentrations, the known no biological function of this metal in the earthworms metabolism lead to suppose that Hg measured was not present in bioaccumulable forms. BCFs estimated for the other metals were generally higher in the highest dredged sediment doses.

  1. Exposure and food web transfer of pharmaceuticals in ospreys (Pandion haliaetus): Predictive model and empirical data

    Science.gov (United States)

    Lazarus, Rebecca S.; Rattner, Barnett A.; Du, Bowen; McGowan, Peter C.; Blazer, Vicki; Ottinger, Mary Ann

    2015-01-01

    The osprey (Pandion haliaetus) is a well-known sentinel of environmental contamination, yet no studies have traced pharmaceuticals through the water–fish–osprey food web. A screening-level exposure assessment was used to evaluate the bioaccumulation potential of 113 pharmaceuticals and metabolites, and an artificial sweetener in this food web. Hypothetical concentrations in water reflecting “wastewater effluent dominated” or “dilution dominated” scenarios were combined with pH-specific bioconcentration factors (BCFs) to predict uptake in fish. Residues in fish and osprey food intake rate were used to calculate the daily intake (DI) of compounds by an adult female osprey. Fourteen pharmaceuticals and a drug metabolite with a BCF greater than 100 and a DI greater than 20 µg/kg were identified as being most likely to exceed the adult human therapeutic dose (HTD). These 15 compounds were also evaluated in a 40 day cumulative dose exposure scenario using first-order kinetics to account for uptake and elimination. Assuming comparable absorption to humans, the half-lives (t1/2) for an adult osprey to reach the HTD within 40 days were calculated. For 3 of these pharmaceuticals, the estimated t1/2 in ospreys was less than that for humans, and thus an osprey might theoretically reach or exceed the HTD in 3 to 7 days. To complement the exposure model, 24 compounds were quantified in water, fish plasma, and osprey nestling plasma from 7 potentially impaired locations in Chesapeake Bay. Of the 18 analytes detected in water, 8 were found in fish plasma, but only 1 in osprey plasma (the antihypertensive diltiazem). Compared to diltiazem detection rate and concentrations in water (10/12 detects, time, and there is no evidence to suggest adverse effects. This screening-level exposure model can help identify those compounds that warrant further investigation in high-trophic level species.

  2. Fractionation, transfer, and ecological risks of heavy metals in riparian and ditch wetlands across a 100-year chronosequence of reclamation in an estuary of China

    International Nuclear Information System (INIS)

    Xiao, Rong; Bai, Junhong; Lu, Qiongqiong; Zhao, Qingqing; Gao, Zhaoqin; Wen, Xiaojun; Liu, Xinhui

    2015-01-01

    The effect of reclamation on heavy metal concentrations and the ecological risks in ditch wetlands (DWs) and riparian wetlands (RWs) across a 100-year chronosequence in the Pearl River Estuary of China was investigated. Concentrations of 4 heavy metals (Cd, Cu, Pb, and Zn) in soil and plant samples, and sequential extracts of soil samples were determined, using inductively coupled plasma atomic absorption spectrometry. Results showed that heavy metal concentrations were higher in older DW soils than in the younger ones, and that the younger RW soils contained higher heavy metal concentrations compared to the older ones. Although the increasing tendency of heavy metal concentrations in soil was obvious after wetland reclamation, the metals Cu, Pb, and Zn exhibited low or no risks to the environment based on the risk assessment code (RAC). Cd, on the other hand, posed a medium or high risk. Cd, Pb, and Zn were mainly bound to Fe–Mn oxide, whereas most of Cu remained in the residual phase in both ditch and riparian wetland soils, and the residual proportions generally increased with depth. Bioconcentration and translocation factors for most of these four heavy metals significantly decreased in the DWs with older age (p < 0.05), whereas they increased in the RWs with younger age (p < 0.05). The DW soils contained higher concentrations of heavy metals in the organic fractions, whereas there were more carbonate and residual fractions in the RW soils. The non-bioavailable fractions of Cu and Zn, and the organic-bound Cd and Pb significantly inhibited plant growth. - Highlights: • Heavy metals in ditch wetland accumulated with increasing reclamation history. • Heavy metals exist in the Fe–Mn oxides and residual fractions in both wetlands. • Cd posed a medium to high environmental risk while low risk for other metals. • Long reclamation history caused lower BCFs and TFs in DWs and higher levels in RWs. • RW soils contained more heavy metals in the carbonate

  3. Sublethal toxicity and biotransformation of pyrene in Lumbriculus variegatus (Oligochaeta)

    International Nuclear Information System (INIS)

    Maeenpaeae, K.; Leppaenen, M.T.; Kukkonen, J.V.K.

    2009-01-01

    The aim of this work was to study the toxicity and biotransformation of polyaromatic hydrocarbon (PAH) pyrene in the oligochaete aquatic worm, Lumbriculus variegatus. PAHs are ubiquitous environmental pollutants that pose a hazard to aquatic organisms, and metabolizing capability is poorly known in the case of many invertebrate species. To study the toxicity and biotransformation of pyrene, the worm was exposed for 15 days to various concentrations of water-borne pyrene. The dorsal blood vessel pulse rate was used as a sublethal endpoint. Pyrene biotransformation by L. variegatus was studied and the critical body residues (CBR) were estimated for pyrene toxicity. The toxicokinetics of pyrene uptake was evaluated. A combination of radiolabeled ( 14 C) and nonlabeled pyrene was used in the exposures, and liquid scintillation counting (LSC) and high-pressure liquid chromatography were employed in both water and tissue residue analyses. The results showed that L. variegatus was moderately able to metabolize pyrene to 1-hydroxypyrene (1-HP), thus demonstrating that the phase-I-like oxidizing enzyme system metabolizes pyrene in L. variegatus. The amount of the 1-HP was 1-2% of the amount of pyrene in the worm tissues. The exposure to pyrene reduced the blood vessel pulse rate significantly (p < 0.05), showing that pyrene had a narcotic effect. The estimated CBRs remained constant during the exposure time, varying from 0.120 to 0.174 mmol pyrene/kg worm wet weight. The bioconcentration factors (BCF) decreased as exposure concentration increased. It was suggested that the increased toxicity of pyrene accounted for the decrease in BCFs by lowering the activity of the organism

  4. Physiologically-based toxicokinetic models help identifying the key factors affecting contaminant uptake during flood events

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, Markus; Eichbaum, Kathrin [Department of Ecosystem Analysis, Institute for Environmental Research,ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany); Kammann, Ulrike [Thünen-Institute of Fisheries Ecology, Palmaille 9, 22767 Hamburg (Germany); Hudjetz, Sebastian [Department of Ecosystem Analysis, Institute for Environmental Research,ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany); Institute of Hydraulic Engineering and Water Resources Management, RWTH Aachen University, Mies-van-der-Rohe-Straße 1, 52056 Aachen (Germany); Cofalla, Catrina [Institute of Hydraulic Engineering and Water Resources Management, RWTH Aachen University, Mies-van-der-Rohe-Straße 1, 52056 Aachen (Germany); Buchinger, Sebastian; Reifferscheid, Georg [Federal Institute of Hydrology (BFG), Department G3: Biochemistry, Ecotoxicology, Am Mainzer Tor 1, 56068 Koblenz (Germany); Schüttrumpf, Holger [Institute of Hydraulic Engineering and Water Resources Management, RWTH Aachen University, Mies-van-der-Rohe-Straße 1, 52056 Aachen (Germany); Preuss, Thomas [Department of Environmental Biology and Chemodynamics, Institute for Environmental Research,ABBt- Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany); and others

    2014-07-01

    Highlights: • A PBTK model for trout was coupled with a sediment equilibrium partitioning model. • The influence of physical exercise on pollutant uptake was studies using the model. • Physical exercise during flood events can increase the level of biliary metabolites. • Cardiac output and effective respiratory volume were identified as relevant factors. • These confounding factors need to be considered also for bioconcentration studies. - Abstract: As a consequence of global climate change, we will be likely facing an increasing frequency and intensity of flood events. Thus, the ecotoxicological relevance of sediment re-suspension is of growing concern. It is vital to understand contaminant uptake from suspended sediments and relate it to effects in aquatic biota. Here we report on a computational study that utilizes a physiologically based toxicokinetic model to predict uptake, metabolism and excretion of sediment-borne pyrene in rainbow trout (Oncorhynchus mykiss). To this end, data from two experimental studies were compared with the model predictions: (a) batch re-suspension experiments with constant concentration of suspended particulate matter at two different temperatures (12 and 24 °C), and (b) simulated flood events in an annular flume. The model predicted both the final concentrations and the kinetics of 1-hydroxypyrene secretion into the gall bladder of exposed rainbow trout well. We were able to show that exhaustive exercise during exposure in simulated flood events can lead to increased levels of biliary metabolites and identified cardiac output and effective respiratory volume as the two most important factors for contaminant uptake. The results of our study clearly demonstrate the relevance and the necessity to investigate uptake of contaminants from suspended sediments under realistic exposure scenarios.

  5. Physiologically-based toxicokinetic models help identifying the key factors affecting contaminant uptake during flood events

    International Nuclear Information System (INIS)

    Brinkmann, Markus; Eichbaum, Kathrin; Kammann, Ulrike; Hudjetz, Sebastian; Cofalla, Catrina; Buchinger, Sebastian; Reifferscheid, Georg; Schüttrumpf, Holger; Preuss, Thomas

    2014-01-01

    Highlights: • A PBTK model for trout was coupled with a sediment equilibrium partitioning model. • The influence of physical exercise on pollutant uptake was studies using the model. • Physical exercise during flood events can increase the level of biliary metabolites. • Cardiac output and effective respiratory volume were identified as relevant factors. • These confounding factors need to be considered also for bioconcentration studies. - Abstract: As a consequence of global climate change, we will be likely facing an increasing frequency and intensity of flood events. Thus, the ecotoxicological relevance of sediment re-suspension is of growing concern. It is vital to understand contaminant uptake from suspended sediments and relate it to effects in aquatic biota. Here we report on a computational study that utilizes a physiologically based toxicokinetic model to predict uptake, metabolism and excretion of sediment-borne pyrene in rainbow trout (Oncorhynchus mykiss). To this end, data from two experimental studies were compared with the model predictions: (a) batch re-suspension experiments with constant concentration of suspended particulate matter at two different temperatures (12 and 24 °C), and (b) simulated flood events in an annular flume. The model predicted both the final concentrations and the kinetics of 1-hydroxypyrene secretion into the gall bladder of exposed rainbow trout well. We were able to show that exhaustive exercise during exposure in simulated flood events can lead to increased levels of biliary metabolites and identified cardiac output and effective respiratory volume as the two most important factors for contaminant uptake. The results of our study clearly demonstrate the relevance and the necessity to investigate uptake of contaminants from suspended sediments under realistic exposure scenarios

  6. Corruption Factors

    OpenAIRE

    Polterovich, Victor

    1998-01-01

    Among the factors that give rise to corruption, it is suggested that three groups be distinguished: fundamental factors rooted in the imperfection of economic institutions and economic policy, organizational factors ("weakness of the government"), and societal factors that depend on the prehistory and are connected with the mass culture and norms of bureaucratic behavior. A model in which corruption equilibrium is supported by non-optimum tax policy or by slow technical progress is compared w...

  7. El factoring

    Directory of Open Access Journals (Sweden)

    Alberto Rosenthal

    1988-04-01

    Full Text Available RESUMEN El artículo  presenta, una conceptualización general de lo que es el factoring, el origen del mismo, su evolución y hace una clasificación de los distintos tipos de factoring.

  8. Organizational factors

    International Nuclear Information System (INIS)

    Holy, J.

    1999-12-01

    The following organizational factors are considered with respect to the human factor and operating safety of nuclear power plants: external influences; objectives and strategy; positions and ways of management; allocation of resources; working with human resources; operators' training; coordination of work; knowledge of organization and management; proceduralization of the topic; labour organizing culture; self-improvement system; and communication. (P.A.)

  9. Molecular effects and bioaccumulation of levonorgestrel in the non-target organism Dreissena polymorpha

    DEFF Research Database (Denmark)

    Contardo-Jara, V.; Lorenz, Claudia; Pflugmacher, S.

    2011-01-01

    of levonorgestrel in a flow-through system. The lowest concentration (0.312 mu g L-1) was 100-fold bioconcentrated within four days. A decrease of the bioconcentration factor was observed within one week for the highest test concentrations (3.12 and 6.24 mu g L-1) suggesting enhanced excretory processes...

  10. Competitiveness factors

    OpenAIRE

    Popa Liliana-Viorica

    2012-01-01

    Porter's theory supports the idea that, despite the globalization of production and trade, the competitive advantage is created in a national framework, nations, through their institutional, natural, cultural, economic characteristics ultimately determining the development of certain economic activities. The factors considered by Porter as determinants for the competitive advantage are grouped in four categories, the linkages between them being important as well

  11. Risk factors

    International Nuclear Information System (INIS)

    Dennery, M.; Dupont, M.A.

    2007-01-01

    This article deals with the development of risk management in the gas sector business: why a risk factor legal mention must precede any published financial information? Do gas companies have to face new risks? Is there specific risks bound to gas activities? Why companies want to master their risks? Is it mandatory or just a new habit? Do they expect a real benefit in return? These are the risk management questions that are analyzed in this article which is based on the public communication of 15 gas companies randomly selected over the world. The information comes from their annual reports or from documents available on their web sites. The intention of this document is not to be exhaustive or to make statistics but only to shade light on the risk factors of the gas sector. (J.S.)

  12. Predicting the bioaccumulation of polyaromatic hydrocarbons and polychlorinated biphenyls in benthic animals in sediments

    Energy Technology Data Exchange (ETDEWEB)

    Tuikka, A.I., E-mail: anitat@student.uef.fi [University of Eastern Finland, Department of Environmental and Biological Sciences, P.O. Box 111, FI-80101 Joensuu (Finland); Leppänen, M.T., E-mail: Matti.T.Leppanen@ymparisto.fi [Finnish Environment Institute, Laboratories/Research and Innovation Laboratory, P.O. Box 35, University of Jyväskylä, FI-40014 Jyväskylä (Finland); Akkanen, J., E-mail: jarkko.akkanen@uef.fi [University of Eastern Finland, Department of Environmental and Biological Sciences, P.O. Box 111, FI-80101 Joensuu (Finland); Sormunen, A.J., E-mail: Arto.Sormunen@mamk.fi [University of Eastern Finland, Department of Environmental and Biological Sciences, P.O. Box 111, FI-80101 Joensuu (Finland); Leonards, P.E.G., E-mail: pim.leonards@vu.nl [Institute for Environmental Studies, Vrije Universiteit Amsterdam, De Boelelaan 1087, 1081 HV Amsterdam (Netherlands); Hattum, B. van, E-mail: bert.vanhattum@deltares.nl [Institute for Environmental Studies, Vrije Universiteit Amsterdam, De Boelelaan 1087, 1081 HV Amsterdam (Netherlands); Vliet, L.A. van, E-mail: lavanvliet@hotmail.com [Ministry of Transport, Public Works and Water Management, National Institute for Coastal and Marine Management/RIKZ, P.O. Box 207, 9750 AE Haren (Netherlands); Brack, W., E-mail: werner.brack@ufz.de [Helmholtz Centre for Environmental Research - UFZ, Department of Effect-Directed Analysis, Permoserstraße 15, 04318 Leipzig (Germany); Smedes, F., E-mail: smedes@recetox.muni.cz [Ministry of Transport, Public Works and Water Management, National Institute for Coastal and Marine Management/RIKZ, P.O. Box 207, 9750 AE Haren (Netherlands); and others

    2016-09-01

    There were two main objectives in this study. The first was to compare the accuracy of different prediction methods for the chemical concentrations of polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the organism, based on the measured chemical concentrations existing in sediment dry matter or pore water. The predicted tissue concentrations were compared to the measured ones after 28-day laboratory test using oligochaeta worms (Lumbriculus variegatus). The second objective was to compare the bioaccumulation of PAHs and PCBs in the laboratory test with the in situ bioaccumulation of these compounds. Using the traditional organic carbon-water partitioning model, tissue concentrations were greatly overestimated, based on the concentrations in the sediment dry matter. Use of an additional correction factor for black carbon with a two-carbon model, significantly improved the bioaccumulation predictions, thus confirming that black carbon was important in binding the chemicals and reducing their accumulation. The predicted PAH tissue concentrations were, however, high compared to the observed values. The chemical concentrations were most accurately predicted from their freely dissolved pore water concentrations, determined using equilibrium passive sampling. The patterns of PCB and PAH accumulation in sediments for laboratory-exposed L. variegatus were similar to those in field-collected Lumbriculidae worms. Field-collected benthic invertebrates and L. variegatus accumulated less PAHs than PCBs with similar lipophilicity. The biota to sediment accumulation factors of PAHs tended to decrease with increasing sediment organic carbon normalized concentrations. The presented data yields bioconcentration factors (BCF) describing the chemical water-lipid partition, which were found to be higher than the octanol-water partition coefficients, but on a similar level with BCFs drawn from relevant literature. In conclusion, using the two-carbon model method

  13. Accumulation and spatial distribution of Cd, Cr, and Pb in mulberry from municipal solid waste compost following application of EDTA and (NH4)2SO4.

    Science.gov (United States)

    Zhao, Shulan; Shang, Xiaojuan; Duo, Lian

    2013-02-01

    , especially when combined with (NH(4))(2)SO(4). Mulberry exhibited high ability to accumulate Cd with bioconcentration factors (BCFs) higher than 1. EDTA application also significantly increased Cd BCFs. More than 30 % of metal uptake was concentrated in mulberry branches (stem of above 100 cm height) and leaves. Results presented here show that mulberry is a woody plant that has the potential of Cd phytoextraction from MSW compost by removing leaves and cutting branches. The application of EDTA combined with (NH(4))(2)SO(4) significantly enhanced the efficiency of mulberry in removing Cd from the compost medium. Adding (NH(4))(2)SO(4) into the compost will lower the risk of the exposure of environment to excessive non-biodegradable EDTA in a large-scale EDTA-assisted phytoextraction by reducing the dosage of EDTA. In China, the need for sod is increasing day by day. Sod is often produced on arable soil and sold together with soils. This would lead to the soil being infertile and the soil layer thin. After several times' production, the soil can no longer be used for cultivating crops and be destroyed. In order to fully utilize MSW compost resources and save valuable soil resources, MSW compost can be used to replace arable soil to produce sod after extraction of toxic metals in it.

  14. A Major Latex-Like Protein Is a Key Factor in Crop Contamination by Persistent Organic Pollutants1[W][OA

    Science.gov (United States)

    Inui, Hideyuki; Sawada, Mami; Goto, Junya; Yamazaki, Kiyoshi; Kodama, Noriko; Tsuruta, Hiroki; Eun, Heesoo

    2013-01-01

    This is the first report, to our knowledge, to reveal important factors by which members of the Cucurbitaceae family, such as cucumber (Cucumis sativus), watermelon (Citrullus lanatus), melon (Cucumis melo), pumpkin (Cucurbita pepo), squash (C. pepo), and zucchini (C. pepo), are selectively polluted with highly toxic hydrophobic contaminants, including organochlorine insecticides and dioxins. Xylem sap of C. pepo ssp. pepo, which is a high accumulator of hydrophobic compounds, solubilized the hydrophobic compound pyrene into the aqueous phase via some protein(s). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of xylem sap of two C. pepo subspecies revealed that the amount of 17-kD proteins in C. pepo ssp. pepo was larger than that in C. pepo ssp. ovifera, a low accumulator, suggesting that these proteins may be related to the translocation of hydrophobic compounds. The protein bands at 17 kD contained major latex-like proteins (MLPs), and the corresponding genes MLP-PG1, MLP-GR1, and MLP-GR3 were cloned from the C. pepo cultivars Patty Green and Gold Rush. Expression of the MLP-GR3 gene in C. pepo cultivars was positively correlated with the band intensity of 17-kD proteins and bioconcentration factors toward dioxins and dioxin-like compounds. Recombinant MLP-GR3 bound polychlorinated biphenyls immobilized on magnetic beads, whereas recombinant MLP-PG1 and MLP-GR1 did not. These results indicate that the high expression of MLP-GR3 in C. pepo ssp. pepo plants and the existence of MLP-GR3 in their xylem sap are related to the efficient translocation of hydrophobic contaminants. These findings should be useful for decreasing the contamination of fruit of the Cucurbitaceae family as well as the phytoremediation of hydrophobic contaminants. PMID:23404917

  15. Exposure and food web transfer of pharmaceuticals in ospreys (Pandion haliaetus): Predictive model and empirical data.

    Science.gov (United States)

    Lazarus, Rebecca S; Rattner, Barnett A; Brooks, Bryan W; Du, Bowen; McGowan, Peter C; Blazer, Vicki S; Ottinger, Mary Ann

    2015-01-01

    The osprey (Pandion haliaetus) is a well-known sentinel of environmental contamination, yet no studies have traced pharmaceuticals through the water-fish-osprey food web. A screening-level exposure assessment was used to evaluate the bioaccumulation potential of 113 pharmaceuticals and metabolites, and an artificial sweetener in this food web. Hypothetical concentrations in water reflecting "wastewater effluent dominated" or "dilution dominated" scenarios were combined with pH-specific bioconcentration factors (BCFs) to predict uptake in fish. Residues in fish and osprey food intake rate were used to calculate the daily intake (DI) of compounds by an adult female osprey. Fourteen pharmaceuticals and a drug metabolite with a BCF greater than 100 and a DI greater than 20 µg/kg were identified as being most likely to exceed the adult human therapeutic dose (HTD). These 15 compounds were also evaluated in a 40 day cumulative dose exposure scenario using first-order kinetics to account for uptake and elimination. Assuming comparable absorption to humans, the half-lives (t1/2 ) for an adult osprey to reach the HTD within 40 days were calculated. For 3 of these pharmaceuticals, the estimated t1/2 in ospreys was less than that for humans, and thus an osprey might theoretically reach or exceed the HTD in 3 to 7 days. To complement the exposure model, 24 compounds were quantified in water, fish plasma, and osprey nestling plasma from 7 potentially impaired locations in Chesapeake Bay. Of the 18 analytes detected in water, 8 were found in fish plasma, but only 1 in osprey plasma (the antihypertensive diltiazem). Compared to diltiazem detection rate and concentrations in water (10/12 detects, osprey plasma samples (540-8630 ng/L), with 41% of these samples exceeding maximum concentrations found in fish. Diltiazem levels in fish and osprey plasma were below the human therapeutic plasma concentration (30000 ng/L). Effect thresholds for diltiazem are unknown in ospreys at this

  16. Trace metal contents in wild edible mushrooms growing on serpentine and volcanic soils on the island of Lesvos, Greece.

    Science.gov (United States)

    Aloupi, M; Koutrotsios, G; Koulousaris, M; Kalogeropoulos, N

    2012-04-01

    The objectives of this survey were (1) to assess for the first time the Cd, Cu, Cr, Fe, Mn, Ni, Pb and Zn contents in wild edible mushrooms (Russula delica, Lactarius sanguifluus, Lactarius semisanguifluus, Lactarius deliciosus, Suillus bellinii) from the island of Lesvos, (2) to investigate the metals' variability among the species, as well as in relation to the chemical composition of the underlying soil, comparing mushrooms collected from volcanic and serpentine substrates and (3) to estimate metal intake by the consumption of the mushrooms under consideration. The trace metals in 139 samples were determined by flame or flameless atomic absorption spectroscopy. The median metal concentrations were as follows: Cd: 0.14; Cr: 0.10; Cu: 8.51; Fe: 30.3; Mn: 5.26; Ni: 0.34; Pb: 0.093 and Zn: 64.50, all in mgkg(-1) dry weight. The observed concentrations are among the lowest reported for mushrooms from Europe or Turkey, while Pb and Cd values did not exceed the limits set by the European Union. Significant species- and substrate-related differences in the metal contents were found, but the variability did not follow a uniform pattern for all the metals in all mushroom species. As a general trend, the mushrooms growing in serpentine sites contained higher Cd, Cr and Ni than those from volcanic sites. The calculated bioconcentration factors (BCFs) showed that none of the mushrooms can be regarded as a metal bioaccumulator, although BCF values slightly above unity were found for Zn in the three Lactarius species, and for Cu in R. delica. The studied mushrooms could supply considerable amounts of essential metals such as Zn and Cr. On the other hand, the consumption of R. delica collected from volcanic soils could provide 12% of the Cd daily tolerable intake and as high as 53% when collected from serpentine soils. Nonetheless, our results indicate that the regular consumption of wild edible mushrooms from Lesvos is quite safe for human health. Copyright © 2011 Elsevier

  17. Medium-chain chlorinated paraffins (MCCPs): a review of bioaccumulation potential in the aquatic environment.

    Science.gov (United States)

    Thompson, Roy; Vaughan, Martin

    2014-01-01

    Chlorinated paraffins (CPs) are high molecular weight organochlorine compounds that have been used in a variety of industrial applications for many years. Medium-chain chlorinated paraffins (MCCPs) (CAS 85535-85-9; Alkanes, C14-17 , chloro) are currently under investigation as potential persistent bioaccumulative toxic (PBT) compounds. In this article, the bioaccumulation potential of MCCPs is assessed using a tiered framework proposed after a recent Society of Environmental Toxicology and Chemistry (SETAC) Pellston Workshop in 2008. The framework proposes the use of physicochemical properties and modeling assessment, bioconcentration/bioaccumulation (BCF/BAF) assessment, biomagnification (BMF) assessment, and trophic magnification factor (TMF) assessment. It is hoped that use of this framework could harmonize and improve the efficiency and effectiveness of the chemical substance evaluation screening process for PBT properties. When applied to MCCPs, the following conclusions were made: empirical physiochemical data is available negating the use of models; laboratory BCFs range from 1000 to 15 000 (growth-corrected lipid normalized values) for 2 MCCP structures; field BAFs were an order of magnitude higher than the trigger criterion for "B status possible"; although results may not meet acceptance criteria for field studies, laboratory-derived BMFs for a number of C14-17 chlorinated alkanes were less than the trigger value of 1 (based on whole-body concentrations) whereas field-derived BMFs were less than 1 (based on lipid corrected values [generally used for field data] excluding one measure for sculpin, [Cottus cognatus]-Diporeia that was based on only one detectable sample); and finally, TMFs were less than the trigger criterion value of 1, which are considered the most convincing evidence for bioaccumulative properties of a compound and the "Gold Standard" measure of bioaccumulation. This article also discusses the uncertainties surrounding the published data

  18. Climate change - An uncertainty factor in risk analysis of contaminated land

    International Nuclear Information System (INIS)

    Augustsson, Anna; Filipsson, Monika; Oberg, Tomas; Bergbaeck, Bo

    2011-01-01

    Metals frequently occur at contaminated sites, where their potential toxicity and persistence require risk assessments that consider possible long-term changes. Changes in climate are likely to affect the speciation, mobility, and risks associated with metals. This paper provides an example of how the climate effect can be inserted in a commonly used exposure model, and how the exposure then changes compared to present conditions. The comparison was made for cadmium (Cd) exposure to 4-year-old children at a highly contaminated iron and steel works site in southeastern Sweden. Both deterministic and probabilistic approaches (through probability bounds analysis, PBA) were used in the exposure assessment. Potential climate-sensitive variables were determined by a literature review. Although only six of the total 39 model variables were assumed to be sensitive to a change in climate (groundwater infiltration, hydraulic conductivity, soil moisture, soil:water distribution, and two bioconcentration factors), the total exposure was clearly affected. For example, by altering the climate-sensitive variables in the order of 15% to 20%, the deterministic estimate of exposure increased by 27%. Similarly, the PBA estimate of the reasonable maximum exposure (RME, defined as the upper bound of the 95th percentile) increased by almost 20%. This means that sites where the exposure in present conditions is determined to be slightly below guideline values may in the future exceed these guidelines, and risk management decisions could thus be affected. The PBA, however, showed that there is also a possibility of lower exposure levels, which means that the changes assumed for the climate-sensitive variables increase the total uncertainty in the probabilistic calculations. This highlights the importance of considering climate as a factor in the characterization of input data to exposure assessments at contaminated sites. The variable with the strongest influence on the result was the

  19. PCBs and organochlorine pesticides in krill, birds and water from Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Sengupta, R.; Sarkar, A.; Kureishy, T.W.

    ; Manchester-Neeswig and Andren, 1989). The distribution of pollutants between water and biota is largely dependent on the bioconcentration factor, which is closely related to the partition coefficient of each chlorinated hydrocarbon. Moreover, the fat...

  20. Heart disease - risk factors

    Science.gov (United States)

    ... prevention; CVD - risk factors; Cardiovascular disease - risk factors; Coronary artery disease - risk factors; CAD - risk factors ... do smoke, quit. Controlling your cholesterol through diet, exercise, and medicines . Controlling high blood pressure through diet, ...

  1. Applicability and performance evaluation of QSAR models for bioconcentration in fish

    DEFF Research Database (Denmark)

    Lombardo, A.; Roncaglioni, A.; Rotoumenou, M. I.

    2011-01-01

    methods (e.g. in-vitro, QSAR or read-across). Goal of this work was to evaluate in which cases QSAR models can replace in-vivo tests. For this reason several QSAR models, developed within OSIRIS project (i.e. ChemPropTM and BCF regressions model for monovalent ionic compounds by Fu et al., 2009) or freely...... available (i.e. EPISuite, T.E.S.T., CAESAR, CORAL and logP-based equations) were tested. Performance and applicability of the models has been evaluated using a large dataset. The models were analysed both as regression models (in particular error distribution and correlation) and as classification models...

  2. Role of pH for the bioconcentration of ionizable organic compounds

    DEFF Research Database (Denmark)

    Trapp, Stefan; Franco, Antonio

    highly correlated to the log D, external pH (except acids in fish) and pKa of the test substances. Existing regressions (Veith and Fu for fish and Briggs RCF for plant cells) with log D (apparent octanol-water partition coefficient) as input parameter were tested for their capability to predict BCF...

  3. BIOCONCENTRATION OF HEAVY METALS IN VERMICOMPOSTING EARTHWORMS (Eisenia fetida, Perionyx excavatus and Lampito mauritii IN NEPAL

    Directory of Open Access Journals (Sweden)

    Raju Panday

    2014-04-01

    Full Text Available Vermicomposting of organic waste can play an important part during the waste management process in larger cities such as Kathmandu where 70% of the waste generated is organic. In this study, the possibility of heavy metal (Pb, Cd, Cu and Cr bioaccumulation by three different species of earthworms Eisenia fetida, Lampito mauritii and Perionyx excavatus in domestic waste vermicompost was investigated. Quantification of heavy metals by Atomic Absorption Spectroscopy(AAS in final vermicompost showed a significant reduction in concentration of metals, Pb (11.4-26.0%, Cd (48-61%, Cu (4.9- 29.01% and Cr (18.90-33.60% at the end. Bioaccumulation of heavy metal in the composting earthworms was also recorded. Comparison of the three groups of earthworms showed that the bioaccumulation of Pb, Cu and Cr was greater for P. excavatus whereas E. fetida was the most reluctant. Heavy metal content in the vermicompost was within the limit of USEPA for Biosolids and the compost could be used for the agriculture purpose.

  4. Heavy metals bioconcentration from soil to vegetables and assessment of health risk caused by their ingestion.

    Science.gov (United States)

    Garg, V K; Yadav, Poonam; Mor, Suman; Singh, Balvinder; Pulhani, Vandana

    2014-03-01

    The present study was undertaken to assess the non-carcinogenic human health risk of heavy metals through the ingestion of locally grown and commonly used vegetables viz. Raphanus sativus (root vegetable), Daucus carota (root vegetable), Benincasa hispida (fruit vegetable) and Brassica campestris leaves (leafy vegetable) in a semi-urbanized area of Haryana state, India. Heavy metal quantification of soil and vegetable samples was done using flame atomic absorption spectrophotometer. Lead, cadmium and nickel concentration in vegetable samples varied in range of 0.12-6.54 mg kg(-1), 0.02-0.67 mg kg(-1) and metals' uptake was more by leafy vegetable than root and fruit vegetables. Hazard index of all the vegetables was less than unity; thus, the ingestion of these vegetables is unlikely to pose health risks to the target population.

  5. Effect of pH on the toxicity and bioconcentration of sulfadiazine on Daphnia magna

    DEFF Research Database (Denmark)

    Anskjær, Gitte Gotholdt; Rendal, Cecilie; Kusk, Kresten Ole

    2013-01-01

    The antimicrobial sulfonamide sulfadiazine has in the last decades been detected in environmental water bodies, both surface and ground water. Since pH in the environment may vary considerably, this study examined the toxicity of the amphoter sulfadiazine towards Daphnia magna at pH levels of 6...

  6. Arsenic (V) bioconcentration kinetics in freshwater macroinvertebrates and periphyton is influenced by pH.

    Science.gov (United States)

    Lopez, Adeline R; Funk, David H; Buchwalter, David B

    2017-05-01

    Arsenic is an important environmental pollutant whose speciation and mobility in freshwater food webs is complex. Few studies have characterized uptake and efflux rates of arsenic in aquatic benthic invertebrates. Further, we lack a fundamental understanding of how pH influences uptake kinetics in these organisms or how this key environmental variable could alter dietary exposure for primary consumers. Here we used a radiotracer approach to characterize arsenate accumulation dynamics in benthic invertebrates, the influence of pH on uptake in a subset of these organisms, and the influence of pH on uptake of arsenate by periphyton - an important food source at the base of aquatic food webs. Uptake rate constants (K u ) from aqueous exposure were modest, ranging from ∼0.001 L g -1 d -1 in three species of mayfly to 0.06 L g -1 d -1 in Psephenus herricki. Efflux rate constants ranged from ∼0.03 d -1 in Corbicula fluminea to ∼0.3 d -1 in the mayfly Isonychia sp, and were generally high. Arsenate uptake decreased with increasing pH, which may be a function of increased adsorption at lower pHs. A similar but much stronger correlation was observed for periphyton where K u decreased from ∼3.0 L g -1 d -1  at 6.5 pH to ∼0.7 L g -1 d -1  at 8.5 pH, suggesting that site specific pH could significantly alter arsenic exposure, particularly for primary consumers. Together, these findings shed light on the complexity of arsenic bioavailability and help explain observed differences reported in the literature. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Risk Factors for Scleroderma

    Science.gov (United States)

    ... are here: Home For Patients Risk Factors Risk Factors for Scleroderma The cause of scleroderma is still ... Scientists are working diligently to understand what biological factors contribute to scleroderma pathogenesis. Genetic Risk Scleroderma does ...

  8. Factors and factorizations of graphs proof techniques in factor theory

    CERN Document Server

    Akiyama, Jin

    2011-01-01

    This book chronicles the development of graph factors and factorizations. It pursues a comprehensive approach, addressing most of the important results from hundreds of findings over the last century. One of the main themes is the observation that many theorems can be proved using only a few standard proof techniques. This stands in marked contrast to the seemingly countless, complex proof techniques offered by the extant body of papers and books. In addition to covering the history and development of this area, the book offers conjectures and discusses open problems. It also includes numerous explanatory figures that enable readers to progressively and intuitively understand the most important notions and proofs in the area of factors and factorization.

  9. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ; SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and

  10. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2010-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ;SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and can

  11. Stochastic Matrix Factorization

    OpenAIRE

    Adams, Christopher

    2016-01-01

    This paper considers a restriction to non-negative matrix factorization in which at least one matrix factor is stochastic. That is, the elements of the matrix factors are non-negative and the columns of one matrix factor sum to 1. This restriction includes topic models, a popular method for analyzing unstructured data. It also includes a method for storing and finding pictures. The paper presents necessary and sufficient conditions on the observed data such that the factorization is unique. I...

  12. ISS Payload Human Factors

    Science.gov (United States)

    Ellenberger, Richard; Duvall, Laura; Dory, Jonathan

    2016-01-01

    The ISS Payload Human Factors Implementation Team (HFIT) is the Payload Developer's resource for Human Factors. HFIT is the interface between Payload Developers and ISS Payload Human Factors requirements in SSP 57000. ? HFIT provides recommendations on how to meet the Human Factors requirements and guidelines early in the design process. HFIT coordinates with the Payload Developer and Astronaut Office to find low cost solutions to Human Factors challenges for hardware operability issues.

  13. Factors affecting construction performance: exploratory factor analysis

    Science.gov (United States)

    Soewin, E.; Chinda, T.

    2018-04-01

    The present work attempts to develop a multidimensional performance evaluation framework for a construction company by considering all relevant measures of performance. Based on the previous studies, this study hypothesizes nine key factors, with a total of 57 associated items. The hypothesized factors, with their associated items, are then used to develop questionnaire survey to gather data. The exploratory factor analysis (EFA) was applied to the collected data which gave rise 10 factors with 57 items affecting construction performance. The findings further reveal that the items constituting ten key performance factors (KPIs) namely; 1) Time, 2) Cost, 3) Quality, 4) Safety & Health, 5) Internal Stakeholder, 6) External Stakeholder, 7) Client Satisfaction, 8) Financial Performance, 9) Environment, and 10) Information, Technology & Innovation. The analysis helps to develop multi-dimensional performance evaluation framework for an effective measurement of the construction performance. The 10 key performance factors can be broadly categorized into economic aspect, social aspect, environmental aspect, and technology aspects. It is important to understand a multi-dimension performance evaluation framework by including all key factors affecting the construction performance of a company, so that the management level can effectively plan to implement an effective performance development plan to match with the mission and vision of the company.

  14. Factorization of the Ising model form factors

    International Nuclear Information System (INIS)

    Assis, M; McCoy, B M; Maillard, J-M

    2011-01-01

    We present a general method for analytically factorizing the n-fold form factor integrals f (n) N,N (t) for the correlation functions of the Ising model on the diagonal in terms of the hypergeometric functions 2 F 1 ([1/2, N + 1/2]; [N + 1]; t) which appear in the form factor f (1) N,N (t). New quadratic recursion and quartic identities are obtained for the form factors for n = 2, 3. For n = 2, 3, 4 explicit results are given for the form factors. These factorizations are proved for all N for n = 2, 3. These results yield the emergence of palindromic polynomials canonically associated with elliptic curves. As a consequence, understanding the form factors amounts to describing and understanding an infinite set of palindromic polynomials, canonically associated with elliptic curves. From an analytical viewpoint the relation of these palindromic polynomials with hypergeometric functions associated with elliptic curves is made very explicitly, and from a differential algebra viewpoint this corresponds to the emergence of direct sums of differential operators homomorphic to symmetric powers of a second order operator associated with elliptic curve.

  15. Bayesian Exploratory Factor Analysis

    DEFF Research Database (Denmark)

    Conti, Gabriella; Frühwirth-Schnatter, Sylvia; Heckman, James J.

    2014-01-01

    This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor, and the corr......This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor......, and the corresponding factor loadings. Classical identification criteria are applied and integrated into our Bayesian procedure to generate models that are stable and clearly interpretable. A Monte Carlo study confirms the validity of the approach. The method is used to produce interpretable low dimensional aggregates...

  16. Heart Disease Risk Factors

    Science.gov (United States)

    ... risk factors are unique to women. These include: Menopause Use of hormonal birth control (certain types of combination pills, patches, ... risk factors are unique to women. These include: Menopause Use of hormonal birth control (certain types of combination pills, patches, ...

  17. Stroke - risk factors

    Science.gov (United States)

    ... Brain cells can die, causing lasting damage. Risk factors are things that increase your chance of getting ... disease or condition. This article discusses the risk factors for stroke and things you can do to ...

  18. Annual Adjustment Factors

    Data.gov (United States)

    Department of Housing and Urban Development — The Department of Housing and Urban Development establishes the rent adjustment factors - called Annual Adjustment Factors (AAFs) - on the basis of Consumer Price...

  19. Human factors in training

    International Nuclear Information System (INIS)

    Dutton, J.W.; Brown, W.R.

    1981-01-01

    The Human Factors concept is a focused effort directed at those activities which require human involvement. Training is, by its nature, an activity totally dependent on the Human Factor. This paper identifies several concerns significant to training situations and discusses how Human Factor awareness can increase the quality of learning. Psychology in the training arena is applied Human Factors. Training is a method of communication represented by sender, medium, and receiver. Two-thirds of this communications model involves the human element directly

  20. Mesonic Form Factors

    International Nuclear Information System (INIS)

    Bonnet, Frederic D.R.; Edwards, Robert G.; Felming, George T.; Randal Lewis; David Richards

    2003-01-01

    We have started a program to compute the electromagnetic form factors of mesons. We discuss the techniques used to compute the pion form factor and present preliminary results computed with domain wall valence fermions on MILC asqtad lattices, as well as Wilson fermions on quenched lattices. These methods can easily be extended to rho-to-gamma-pi transition form factors

  1. Bayesian Exploratory Factor Analysis

    Science.gov (United States)

    Conti, Gabriella; Frühwirth-Schnatter, Sylvia; Heckman, James J.; Piatek, Rémi

    2014-01-01

    This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor, and the corresponding factor loadings. Classical identification criteria are applied and integrated into our Bayesian procedure to generate models that are stable and clearly interpretable. A Monte Carlo study confirms the validity of the approach. The method is used to produce interpretable low dimensional aggregates from a high dimensional set of psychological measurements. PMID:25431517

  2. Migration and health risks of nonylphenol and bisphenol a in soil-winter wheat systems with long-term reclaimed water irrigation.

    Science.gov (United States)

    Wang, Shiyu; Liu, Fei; Wu, Wenyong; Hu, Yaqi; Liao, Renkuan; Chen, Gaoting; Wang, Jiulong; Li, Jialin

    2018-04-12

    Reclaimed water reuse has become an important means of alleviating agricultural water shortage worldwide. However, the presence of endocrine disrupters has roused up considerable attention. Barrel test in farmland was conducted to investigate the migration of nonylphenol (NP) and bisphenol A (BPA) in soil-winter wheat system simulating reclaimed water irrigation. Additionally, the health risks on humans were assessed based on US EPA risk assessment model. The migration of NP and BPA decreased from the soil to the winter wheat; the biological concentration factors (BCFs) of NP and BPA in roots, stems, leaves, and grains all decreased with their added concentrations in soils. The BCFs of NP and BPA in roots were greatest (0.60-5.80 and 0.063-1.45, respectively). The average BCFs of NP and BPA in winter wheat showed negative exponential relations to their concentrations in soil. The amounts of NP and BPA in soil-winter wheat system accounted for 8.99-28.24% and 2.35-4.95%, respectively, of the initial amounts added into the soils. The hazard quotient (HQ) for children and adults ranged between 10 -6 and 1, so carcinogenic risks could be induced by ingesting winter wheat grains under long-term reclaimed water irrigation. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. demographic factors associated factors associated with malaria ...

    African Journals Online (AJOL)

    userpc

    .8%) than those in other nce of 35.4% which was actors can predispose alence of malaria in a study were significantly eveloping guidelines and more effective disease endemic areas (Bashar et therefore attempts to rmation on possible demographic factors d out in four selected geria; Major Ibrahim B. Hospital Zaria, Hajiya.

  4. BIOACCUMULATION OF LIPID – SOLUBLE POLLUTANTS IN AQUATIC SYSTEMS

    Directory of Open Access Journals (Sweden)

    Natalija Topić Popović

    1999-03-01

    Full Text Available One of the major problems of water pollution is the capability of pollutants to concentrate in aquatic organisms. Bioaccumulation and bioconcentration of such chemicals in fish render it unsuitable for human consumption. Bioconcentration of water pollutants through algae, zooplankton and other organisms, can lead to their accumulation through food.chain, with the fish at the top of the pelagic food web. The occurrence of elevated residue levels of various xenobiotics with increasing trophic level has been demonstrated in a variety of aquatic environments and organisms. The increased bioconcentration occurs with increasing trophic level. The tendency of a chemical to bioconcentrate has been shown to be strongly related to its lipophilicity. Trophic.level differences in bioconcentration are due largely to increased lipid content and decreased chemical elimination efficiency of organisms occupying increasing trophic levels. The accumulation of pollutant is expressed as the bioconcentration factor (BCF, which is determined as the rate of its uptake to the organism and its elimination from it plus the organism growth rate. Chemical uptake efficiency from water, excretion rate, and chemical assimilation efficiency are variable as a function of the octanol.water partition coefficient (Kow.

  5. Sparse Exploratory Factor Analysis.

    Science.gov (United States)

    Trendafilov, Nickolay T; Fontanella, Sara; Adachi, Kohei

    2017-07-13

    Sparse principal component analysis is a very active research area in the last decade. It produces component loadings with many zero entries which facilitates their interpretation and helps avoid redundant variables. The classic factor analysis is another popular dimension reduction technique which shares similar interpretation problems and could greatly benefit from sparse solutions. Unfortunately, there are very few works considering sparse versions of the classic factor analysis. Our goal is to contribute further in this direction. We revisit the most popular procedures for exploratory factor analysis, maximum likelihood and least squares. Sparse factor loadings are obtained for them by, first, adopting a special reparameterization and, second, by introducing additional [Formula: see text]-norm penalties into the standard factor analysis problems. As a result, we propose sparse versions of the major factor analysis procedures. We illustrate the developed algorithms on well-known psychometric problems. Our sparse solutions are critically compared to ones obtained by other existing methods.

  6. New thrombopoietic growth factors

    OpenAIRE

    Kuter, David J.

    2007-01-01

    Although development of first-generation thrombopoietic growth factors (recombinant human thrombopoietin [TPO] and pegylated recombinant human megakaryocyte growth and development factor [PEG-rHuMGDF]) was stopped due to development of antibodies to PEG-rHuMGDF, nonimmunogenic second-generation thrombopoietic growth factors with unique pharmacologic properties have been developed. TPO peptide mimetics contain TPO receptor-activating peptides inserted into complementarity-determining regions o...

  7. The Transcription Factor Encyclopedia

    NARCIS (Netherlands)

    Yusuf, Dimas; Butland, Stefanie L.; Swanson, Magdalena I.; Bolotin, Eugene; Ticoll, Amy; Cheung, Warren A.; Zhang, Xiao Yu Cindy; Dickman, Christopher T. D.; Fulton, Debra L.; Lim, Jonathan S.; Schnabl, Jake M.; Ramos, Oscar H. P.; Vasseur-Cognet, Mireille; de Leeuw, Charles N.; Simpson, Elizabeth M.; Ryffel, Gerhart U.; Lam, Eric W.-F.; Kist, Ralf; Wilson, Miranda S. C.; Marco-Ferreres, Raquel; Brosens, Jan J.; Beccari, Leonardo L.; Bovolenta, Paola; Benayoun, Bérénice A.; Monteiro, Lara J.; Schwenen, Helma D. C.; Grontved, Lars; Wederell, Elizabeth; Mandrup, Susanne; Veitia, Reiner A.; Chakravarthy, Harini; Hoodless, Pamela A.; Mancarelli, M. Michela; Torbett, Bruce E.; Banham, Alison H.; Reddy, Sekhar P.; Cullum, Rebecca L.; Liedtke, Michaela; Tschan, Mario P.; Vaz, Michelle; Rizzino, Angie; Zannini, Mariastella; Frietze, Seth; Farnham, Peggy J.; Eijkelenboom, Astrid; Brown, Philip J.; Laperrière, David; Leprince, Dominique; de Cristofaro, Tiziana; Prince, Kelly L.; Putker, Marrit; del Peso, Luis; Camenisch, Gieri; Wenger, Roland H.; Mikula, Michal; Rozendaal, Marieke; Mader, Sylvie; Ostrowski, Jerzy; Rhodes, Simon J.; van Rechem, Capucine; Boulay, Gaylor; Olechnowicz, Sam W. Z.; Breslin, Mary B.; Lan, Michael S.; Nanan, Kyster K.; Wegner, Michael; Hou, Juan; Mullen, Rachel D.; Colvin, Stephanie C.; Noy, Peter John; Webb, Carol F.; Witek, Matthew E.; Ferrell, Scott; Daniel, Juliet M.; Park, Jason; Waldman, Scott A.; Peet, Daniel J.; Taggart, Michael; Jayaraman, Padma-Sheela; Karrich, Julien J.; Blom, Bianca; Vesuna, Farhad; O'Geen, Henriette; Sun, Yunfu; Gronostajski, Richard M.; Woodcroft, Mark W.; Hough, Margaret R.; Chen, Edwin; Europe-Finner, G. Nicholas; Karolczak-Bayatti, Magdalena; Bailey, Jarrod; Hankinson, Oliver; Raman, Venu; Lebrun, David P.; Biswal, Shyam; Harvey, Christopher J.; Debruyne, Jason P.; Hogenesch, John B.; Hevner, Robert F.; Héligon, Christophe; Luo, Xin M.; Blank, Marissa Cathleen; Millen, Kathleen Joyce; Sharlin, David S.; Forrest, Douglas; Dahlman-Wright, Karin; Zhao, Chunyan; Mishima, Yuriko; Sinha, Satrajit; Chakrabarti, Rumela; Portales-Casamar, Elodie; Sladek, Frances M.; Bradley, Philip H.; Wasserman, Wyeth W.

    2012-01-01

    Here we present the Transcription Factor Encyclopedia (TFe), a new web-based compendium of mini review articles on transcription factors (TFs) that is founded on the principles of open access and collaboration. Our consortium of over 100 researchers has collectively contributed over 130 mini review

  8. Factors affecting nuclear development

    International Nuclear Information System (INIS)

    Stevens, G.H.; Girouard, P.

    1995-01-01

    Among the factors affecting nuclear development, some depend more or less on public authorities, but many are out of public authorities control (foreign policies, market and deregulation, socials and environmental impacts, public opinion). As far as possible, the following study tries to identify those factors. (D.L.). 2 photos

  9. [Vulnerability factors to depression].

    Science.gov (United States)

    Bugán, Antal; Margitics, Ferenc; Pauwlik, Zsuzsa

    2006-01-01

    The objective of this study is to reveal in their complexity the biological and cognitive vulnerability factors, as well as the environmental and socialisation predisposing factors playing a role in the development of depression in non-clinical sample of subjects (college students). Biological vulnerability was examined through temperament and character features, cognitive vulnerability was examined through dysfunctional attitudes, attributional style and coping strategies, and environmental, socialization predisposing factors were observed through certain family socialisation effects (type of family atmosphere, educational objectives, educational and rearing attitudes and style) and parental rearing behaviour. 681 college students were involved in this study (465 females, 216 males). Students were assigned to the study group if they fell in the fourth quartile of the sample based on the results obtained by the Beck's Depression Inventory: 170 persons (128 females, 42 males). Students who fell in the first quartile of the sample on the basis of their results obtained by the mentioned Inventory formed the control group: 204 persons (118 females, 86 males). The results of our study have demonstrated that in a sub-clinical sample the lack of parental care was observed to be a socialization predisposing factor in the development of depression, while certain dysfunctional attitudes and pessimistic interpretation styles were detected to be cognitive vulnerability factors, and harm avoidance proved to be a biological vulnerability factor. We also managed to reveal the effects of certain background factors, which produce their influence indirectly through mediating factors.

  10. Rh Factor Blood Test

    Science.gov (United States)

    Rh factor blood test Overview Rhesus (Rh) factor is an inherited protein found on the surface of red blood cells. If your ... Rh negative, you might need to have another blood test — an antibody screen — during your first trimester and ...

  11. Respirator field performance factors

    International Nuclear Information System (INIS)

    Skaggs, B.J.; DeField, J.D.; Strandberg, S.W.; Sutcliffe, C.R.

    1985-01-01

    The Industrial Hygiene Group assisted OSHA and the NRC in measurements of respirator performance under field conditions. They reviewed problems associated with sampling aerosols within the respirator in order to determine fit factors (FFs) or field performance factor (FPF). In addition, they designed an environmental chamber study to determine the effects of temperature and humidity on a respirator wearer

  12. Exploratory Bi-Factor Analysis

    Science.gov (United States)

    Jennrich, Robert I.; Bentler, Peter M.

    2011-01-01

    Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger. The bi-factor model has a general factor and a number of group factors. The purpose of this article is to introduce an exploratory form of bi-factor analysis. An advantage of using exploratory bi-factor analysis is that one need not provide a specific…

  13. Factor V Leiden thrombophilia.

    Science.gov (United States)

    Kujovich, Jody Lynn

    2011-01-01

    Factor V Leiden is a genetic disorder characterized by a poor anticoagulant response to activated Protein C and an increased risk for venous thromboembolism. Deep venous thrombosis and pulmonary embolism are the most common manifestations, but thrombosis in unusual locations also occurs. The current evidence suggests that the mutation has at most a modest effect on recurrence risk after initial treatment of a first venous thromboembolism. Factor V Leiden is also associated with a 2- to 3-fold increased relative risk for pregnancy loss and possibly other obstetric complications, although the probability of a successful pregnancy outcome is high. The clinical expression of Factor V Leiden is influenced by the number of Factor V Leiden alleles, coexisting genetic and acquired thrombophilic disorders, and circumstantial risk factors. Diagnosis requires the activated Protein C resistance assay (a coagulation screening test) or DNA analysis of the F5 gene, which encodes the Factor V protein. The first acute thrombosis is treated according to standard guidelines. Decisions regarding the optimal duration of anticoagulation are based on an individualized assessment of the risks for venous thromboembolism recurrence and anticoagulant-related bleeding. In the absence of a history of thrombosis, long-term anticoagulation is not routinely recommended for asymptomatic Factor V Leiden heterozygotes, although prophylactic anticoagulation may be considered in high-risk clinical settings. In the absence of evidence that early diagnosis reduces morbidity or mortality, decisions regarding testing at-risk family members should be made on an individual basis.

  14. Recombinant clotting factors.

    Science.gov (United States)

    Pipe, Steven W

    2008-05-01

    The recombinant era for haemophilia began in the early 1980s with the cloning and subsequent expression of functional proteins for both factors VIII and IX. Efficient production of recombinant clotting factors in mammalian cell culture systems required overcoming significant challenges due to the complex post-translational modifications that were integral to their pro-coagulant function. The quick development and commercialization of recombinant clotting factors was, in part, facilitated by the catastrophic impact of viral contamination of plasma-derived clotting factor concentrates at the time. Since their transition into the clinic, the recombinant versions of both factor VIII and IX have proven to be remarkable facsimiles of their plasma-derived counterparts. The broad adoption of recombinant therapy throughout the developed world has significantly increased the supply of clotting factor concentrates and helped advance aggressive therapeutic interventions such as prophylaxis. The development of recombinant VIIa was a further advance bringing a recombinant option to haemophilia patients with inhibitors. Recombinant DNA technology remains the platform to address ongoing challenges in haemophilia care such as reducing the costs of therapy, increasing the availability to the developing world, and improving the functional properties of these proteins. In turn, the ongoing development of new recombinant clotting factor concentrates is providing alternatives for patients with other inherited bleeding disorders.

  15. Factorized Graph Matching.

    Science.gov (United States)

    Zhou, Feng; de la Torre, Fernando

    2015-11-19

    Graph matching (GM) is a fundamental problem in computer science, and it plays a central role to solve correspondence problems in computer vision. GM problems that incorporate pairwise constraints can be formulated as a quadratic assignment problem (QAP). Although widely used, solving the correspondence problem through GM has two main limitations: (1) the QAP is NP-hard and difficult to approximate; (2) GM algorithms do not incorporate geometric constraints between nodes that are natural in computer vision problems. To address aforementioned problems, this paper proposes factorized graph matching (FGM). FGM factorizes the large pairwise affinity matrix into smaller matrices that encode the local structure of each graph and the pairwise affinity between edges. Four are the benefits that follow from this factorization: (1) There is no need to compute the costly (in space and time) pairwise affinity matrix; (2) The factorization allows the use of a path-following optimization algorithm, that leads to improved optimization strategies and matching performance; (3) Given the factorization, it becomes straight-forward to incorporate geometric transformations (rigid and non-rigid) to the GM problem. (4) Using a matrix formulation for the GM problem and the factorization, it is easy to reveal commonalities and differences between different GM methods. The factorization also provides a clean connection with other matching algorithms such as iterative closest point; Experimental results on synthetic and real databases illustrate how FGM outperforms state-of-the-art algorithms for GM. The code is available at http://humansensing.cs.cmu.edu/fgm.

  16. [Human factors in medicine].

    Science.gov (United States)

    Lazarovici, M; Trentzsch, H; Prückner, S

    2017-01-01

    The concept of human factors is commonly used in the context of patient safety and medical errors, all too often ambiguously. In actual fact, the term comprises a wide range of meanings from human-machine interfaces through human performance and limitations up to the point of working process design; however, human factors prevail as a substantial cause of error in complex systems. This article presents the full range of the term human factors from the (emergency) medical perspective. Based on the so-called Swiss cheese model by Reason, we explain the different types of error, what promotes their emergence and on which level of the model error prevention can be initiated.

  17. Two-factor authentication

    CERN Document Server

    Stanislav, Mark

    2015-01-01

    During the book, readers will learn about the various technical methods by which two-factor authentication is implemented, security concerns with each type of implementation, and contextual details to frame why and when these technologies should be used. Readers will also be provided with insight about the reasons that two-factor authentication is a critical security control, events in history that have been important to prove why organization and individual would want to use two factor, and core milestones in the progress of growing the market.

  18. Rh Factor Blood Test

    Science.gov (United States)

    ... June 3, 2015. Rh factor blood test About Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  19. Shell Buckling Knockdown Factors

    Data.gov (United States)

    National Aeronautics and Space Administration — The Shell Buckling Knockdown Factor (SBKF) Project, NASA Engineering and Safety Center (NESC) Assessment #: 07-010-E, was established in March of 2007 by the NESC in...

  20. Risk factors for neoplasms

    International Nuclear Information System (INIS)

    Brachner, A.; Grosche, B.

    1991-06-01

    A broad survey is given of risk factors for neoplasms. The main carcinogenic substances (including also ionizing radiation and air pollution) are listed, and are correlated with the risk factors for various cancers most frequently explained and discussed in the literature. The study is intended to serve as a basis for a general assessment of the incidence of neoplasms in children, and of cancer mortality in the entire population of Bavaria in the years 1983-1989, or 1979-1988, respectively, with the principal idea of drawing up an environment-related health survey. The study therefore takes into account not only ionizing radiation as a main risk factor, but also other risk factors detectable within the ecologic context, as e.g. industrial installations and their effects, refuse incineration plants or waste dumps, or the social status. (orig./MG) [de

  1. [Risk factors of schizophrenia].

    Science.gov (United States)

    Suvisaari, Jaana

    2010-01-01

    Schizophrenia is a multifactorial, neurodevelopmental disorder caused by a combination of genetic and environmental risk factors. Disturbances of brain development begin prenatally, while different environmental insults further affect postnatal brain maturation during childhood and adolescence. Genome-wide association studies (GWAS) have succeeded in identifying hundreds of new risk variants for common, multifactorial diseases. In schizophrenia research, GWAS have found several rare copy number variants that considerably increase the risk of schizophrenia, and have shown an association between schizophrenia and the major histocompatibility complex. Research on environmental risk factors in recent years has provided new information particularly on risk factors related to pregnancy and childhood rearing environment. Gene-environment interactions have become a central research topic. There is evidence that genetically susceptible children are more vulnerable to the effects of unstable childhood rearing environment and other environmental risk factors.

  2. Human Factors Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The purpose of the Human Factors Laboratory is to further the understanding of highway user needs so that those needs can be incorporated in roadway design,...

  3. Trespass event risk factors.

    Science.gov (United States)

    2014-11-12

    The Volpe Center has used three sources of datathe Federal Railroad Administrations required accident reports, locomotive video, and U.S. Census datato investigate common risk factors for railroad trespassing incidents, the leading cause of ...

  4. Human factors in aviation

    National Research Council Canada - National Science Library

    Salas, Eduardo; Maurino, Daniel E

    2010-01-01

    .... HFA offers a comprehensive overview of the topic, taking readers from the general to the specific, first covering broad issues, then the more specific topics of pilot performance, human factors...

  5. Factors Affecting Wound Healing

    Science.gov (United States)

    Guo, S.; DiPietro, L.A.

    2010-01-01

    Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutaneous wound healing and the potential cellular and/or molecular mechanisms involved. The factors discussed include oxygenation, infection, age and sex hormones, stress, diabetes, obesity, medications, alcoholism, smoking, and nutrition. A better understanding of the influence of these factors on repair may lead to therapeutics that improve wound healing and resolve impaired wounds. PMID:20139336

  6. Business Intelligence Success Factors

    DEFF Research Database (Denmark)

    Gaardboe, Rikke; Jonasen, Tanja Svarre

    2018-01-01

    Business intelligence (BI) is a strategically important practice in many organizations. Several studies have investigated the factors that contribute to BI success; however, an overview of the critical success factors (CSFs) involved is lacking in the extant literature. We have integrated...... culture. In addition, we contribute to the extant research by extending the framework of information system success and identifying gaps in the extant literature. Furthermore, we contribute to practical implementation through an enhanced understanding of the CSFs related to BI success....

  7. Factors Affecting Wound Healing

    OpenAIRE

    Guo, S.; DiPietro, L.A.

    2010-01-01

    Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutane...

  8. Brain derived neurotrophic factor

    DEFF Research Database (Denmark)

    Mitchelmore, Cathy; Gede, Lene

    2014-01-01

    Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies are curre......Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies...

  9. Impact factor distribution revisited

    Science.gov (United States)

    Huang, Ding-wei

    2017-09-01

    We explore the consistency of a new type of frequency distribution, where the corresponding rank distribution is Lavalette distribution. Empirical data of journal impact factors can be well described. This distribution is distinct from Poisson distribution and negative binomial distribution, which were suggested by previous study. By a log transformation, we obtain a bell-shaped distribution, which is then compared to Gaussian and catenary curves. Possible mechanisms behind the shape of impact factor distribution are suggested.

  10. Los factores de riesgo

    Directory of Open Access Journals (Sweden)

    Justo Senado Dumoy

    1999-01-01

    Full Text Available Sobre el fundamento filosófico de los conceptos de la Dialéctica Materialista, se presenta un análisis en relación con el concepto e interpretación de los Factores de Riesgo.A analysis on the concept and interpretation of risk factors is presented based on the philosophical foundation of the concepts of materialist dialectics.

  11. FGF growth factor analogs

    Energy Technology Data Exchange (ETDEWEB)

    Zamora, Paul O [Gaithersburg, MD; Pena, Louis A [Poquott, NY; Lin, Xinhua [Plainview, NY; Takahashi, Kazuyuki [Germantown, MD

    2012-07-24

    The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.

  12. The stem factor challenge

    International Nuclear Information System (INIS)

    Russell, M.J.; Steele, R. Jr.; DeWall, K.G.; Watkins, J.C.; Bramwell, D.

    1994-01-01

    One of the most important challenges that still needs to be met in the effort to understand the operation of motor-operated, rising-stem valves is the ability to determine stem factor throughout the valve's load range. The stem factor represents the conversion of operator torque to stem thrust. Determining the stem factor is important because some motor-operated valves (MOVs) cannot be tested in the plant at design basis conditions. The ability of these valves to perform their design basis function (typically, to operate against specified flow and pressure loads) must be ensured by analytical methods or by extrapolating from the results of tests conducted at lower loads. Because the stem factor tends to vary in response to friction and lubrication phenomena that occur during loading and wedging, analytical methods and extrapolation methods have been difficult to develop and implement. Early investigations into variability in the stem factor tended to look only at the tip of the iceberg; they focused on what was happening at torque switch trip, which usually occurs at full wedging. In most stems, the stem factor is better (lower) in the wedging transient than before wedging, so working with torque switch trip data alone led many early researchers to false conclusions about the relationship between stem factor and load. However, research at the Idaho National Engineering Laboratory (INEL) has taken a closer look at what happens during the running portion of the closing stroke along with the wedging portion. This shift in focus is important, because functional failure of a valve typically consists of a failure to isolate flow, not a failure to achieve full wedging. Thus, the stem factor that must be determined for a valve's design basis closing requirements is the one that corresponds with the running load before wedging

  13. [Pathological gambling: risk factors].

    Science.gov (United States)

    Bouju, G; Grall-Bronnec, M; Landreat-Guillou, M; Venisse, J-L

    2011-09-01

    In France, consumption of gambling games increased by 148% between 1960 and 2005. In 2004, gamblers lost approximately 0.9% of household income, compared to 0.4% in 1960. This represents approximately 134 Euros per year and per head. In spite of this important increase, the level remains lower than the European average (1%). However, gambling practices may continue to escalate in France in the next few years, particularly with the recent announce of the legalisation of online games and sports betting. With the spread of legalised gambling, pathological gambling rates may increase in France in the next years, in response to more widely available and more attractive gambling opportunities. In this context, there is a need for better understanding of the risk factors that are implicated in the development and maintenance of pathological gambling. This paper briefly describes the major risk factors for pathological gambling by examining the recent published literature available during the first quarter of 2008. This documentary basis was collected by Inserm for the collective expert report procedure on Gambling (contexts and addictions). Seventy-two articles focusing on risk factors for pathological gambling were considered in this review. Only 47 of them were taken into account for analysis. The selection of these 47 publications was based on the guide on literature analysis established by the French National Agency for Accreditation and Assessment in Health (ANAES, 2000). Some publications from more recent literature have also been added, mostly about Internet gambling. We identify three major types of risk factors implicated in gambling problems: some of them are related to the subject (individual factors), others are related to the object of the addiction, here the gambling activity by itself (structural factors), and the last are related to environment (contextual or situational factors). Thus, the development and maintenance of pathological gambling seems to be

  14. Building-transmission factors

    International Nuclear Information System (INIS)

    Woolson, W.A.; Marcum, J.; Scott, W.H.; Staggs, V.E.

    1982-01-01

    Parametric representations (called the nine-parameter formula) of the measurements of the radiation transmission through Japanese house models at the BREN reactor and 60 Co experiments are used to correct the free-in-air (FIA) T65 dose values for buildings shielding in the built-up residential areas at Hiroshima and Nagasaki. The accuracy of transmission factors derived from the nine-parameter formula impact the accuracy of the final-exposure dose estimates in the same manner as the accuracy of weapon yield and FIA radiation transport. A preliminary investigation of the accuracy of these transmission factors, sponsored by the Defense Nuclear Agency, has focused primarily on the adequacy of the Bare Reactor Experiment, Nevada (BREN) radiation environments for producing transmission factor data relevant to the situations at Hiroshima and Nagasaki. In addition, the radiation equivalency of house models used at BREN to Japanese house models and the physical basis for the nine-parameter formula have been studied. This investigation has concluded that the average gamma-ray transmission factors based on the nine-parameter formula are probably too high by about a factor of 2. The large discrepancy between the nine-parameter formula and recent estimates results from the apparent failure to properly account for the large gamma-ray dose component caused by capture gamma rays produced in the house walls by the large neutron flux present at BREN

  15. Risk Factors for Dementia

    Directory of Open Access Journals (Sweden)

    Jen-Hau Chen

    2009-10-01

    Full Text Available Dementia is a complex human disease. The incidence of dementia among the elderly population is rising rapidly worldwide. In the United States, Alzheimer's disease (AD is the leading type of dementia and was the fifth and eighth leading cause of death in women and men aged ≥ 65 years, respectively, in 2003. In Taiwan and many other counties, dementia is a hidden health issue because of its underestimation in the elderly population. In Western countries, the prevalence of AD increases from 1–3% among people aged 60–64 years to 35% among those aged > 85 years. In Taiwan, the prevalence of dementia for people aged ≥ 65 years was 2–4% by 2000. Therefore, it is important to identify protective and risk factors for dementia to prevent this disease at an early stage. Several factors are related to dementia, e.g. age, ethnicity, sex, genetic factors, physical activity, smoking, drug use, education level, alcohol consumption, body mass index, comorbidity, and environmental factors. In this review, we focus on studies that have evaluated the association between these factors and the risk of dementia, especially AD and vascular dementia. We also suggest future research directions for researchers in dementia-related fields.

  16. CATTELL AND EYSENCK FACTOR SCORES RELATED TO COMREY PERSONALITY FACTORS.

    Science.gov (United States)

    Comrey, A L; Duffy, K E

    1968-10-01

    The Eysenck Personality Inventory, the Cattell 16 PF Inventory, and the Comrey Personality Inventory were administered to 272 volunteers. Eysenck and Cattell factor scores were correlated with scores over homogeneous item groups (FHIDs) which define the Comrey test factors. This matrix was factor analyzed to relate the Eysenck and Cattell factor scores to the factor structure underlying the Comrey test. The Eysenck Neuroticism, Comrey Neuroticism, and Cattell second-order Anxiety factors appeared to match. The Eysenck Introversion and the Comrey Shyness factors also matched. The 16 Cattell primary factors overlapped but did not match with the Comrey factors.

  17. Business Intelligence Success Factors

    DEFF Research Database (Denmark)

    Gaardboe, Rikke; Jonasen, Tanja Svarre

    2018-01-01

    Business intelligence (BI) is a strategically important practice in many organizations. Several studies have investi-gated the factors that contribute to BI success; however, an overview of the critical success factors (CSFs) involved is lacking in the extant literature. We have integrated...... the findings of 43 studies after conducting a building block search strategy, refer-ence and citation search, and critical assessment of the identified papers. A framework of information system success was used to identify the CSFs and analyze how researchers identify information system success. We discovered...... 34 CSFs related to BI success. The distinct CSFs identified in the extant literature relate to project management skills (13 papers), management support (20 papers), and user involvement (11 papers). In the articles with operationalized BI success, we found several dis-tinct factors: system quality...

  18. Amblyopia risk factor prevalence.

    Science.gov (United States)

    Arnold, Robert W

    2013-01-01

    In 2003, the American Association for Pediatric Ophthalmology and Strabismus (AAPOS) published a set of risk factors for amblyopia. The intent was to promote uniformity of reporting and development in screening. Because this prevalence is not yet known, this meta-analysis is an attempt to estimate it. Major community preschool eye examination studies were reviewed and AAPOS cut-offs estimated. The approximate prevalence of anisometropia is 1.2%, hyperopia is 6%, astigmatism is 15%, myopia is 0.6%, strabismus is 2.5%, and visual acuity less than 20/40 is 6%. The mean combined prevalence is 21% ± 2% compared to a prevalence of amblyopia 20/40 and worse of 2.5%. Knowing risk factor prevalence simplifies validation efforts. Amblyopia screening with a risk factor sensitivity less than 100% is expected and desirable. Copyright 2013, SLACK Incorporated.

  19. factores psicosociales asociados

    Directory of Open Access Journals (Sweden)

    María Teresa Varela Arévalo

    2007-01-01

    Full Text Available El objetivo de este trabajo fue describir el consumo de sustancias psicoactivas [SPA] ilegales en jóvenes y los factores psicosociales de riesgo y de protección asociados. Participaron 763 estudiantes (46,5% hombres y 52,4% mujeres de una universidad privada de Cali, quienes diligenciaron el cuestionario de factores de riesgo y protección para el consumo de drogas. Los resultados muestran que la marihuana fue la droga de mayor consumo; y que existe una fuerte asociación entre el consumo de las cuatro SPA ilegales (marihuana, opiáceos, cocaína y éxtasis y los factores psicosociales de riesgo y/o protección, principalmente, las habilidades de autocontrol, los preconceptos y valoración de las SPA, la relación con personas consumidoras y los comportamientos perturbadores.

  20. Human factors guides

    International Nuclear Information System (INIS)

    Penington, J.

    1995-10-01

    This document presents human factors guides, which have been developed in order to provide licensees of the AECB with advice as to how to address human factors issues within the design and assessment process. This documents presents the results of a three part study undertaken to develop three guides which are enclosed in this document as Parts B, C and D. As part of the study human factors standards, guidelines, handbooks and other texts were researched, to define those which would be most useful to the users of the guides and for the production of the guides themselves. Detailed specifications were then produced to outline the proposed contents and format of the three guides. (author). 100 refs., 3 tabs., 11 figs

  1. Multi-factor authentication

    Science.gov (United States)

    Hamlet, Jason R; Pierson, Lyndon G

    2014-10-21

    Detection and deterrence of spoofing of user authentication may be achieved by including a cryptographic fingerprint unit within a hardware device for authenticating a user of the hardware device. The cryptographic fingerprint unit includes an internal physically unclonable function ("PUF") circuit disposed in or on the hardware device, which generates a PUF value. Combining logic is coupled to receive the PUF value, combines the PUF value with one or more other authentication factors to generate a multi-factor authentication value. A key generator is coupled to generate a private key and a public key based on the multi-factor authentication value while a decryptor is coupled to receive an authentication challenge posed to the hardware device and encrypted with the public key and coupled to output a response to the authentication challenge decrypted with the private key.

  2. Model Correction Factor Method

    DEFF Research Database (Denmark)

    Christensen, Claus; Randrup-Thomsen, Søren; Morsing Johannesen, Johannes

    1997-01-01

    The model correction factor method is proposed as an alternative to traditional polynomial based response surface techniques in structural reliability considering a computationally time consuming limit state procedure as a 'black box'. The class of polynomial functions is replaced by a limit...... statebased on an idealized mechanical model to be adapted to the original limit state by the model correction factor. Reliable approximations are obtained by iterative use of gradient information on the original limit state function analogously to previous response surface approaches. However, the strength...... of the model correction factor method, is that in simpler form not using gradient information on the original limit state function or only using this information once, a drastic reduction of the number of limit state evaluation is obtained together with good approximations on the reliability. Methods...

  3. Geothermal Plant Capacity Factors

    Energy Technology Data Exchange (ETDEWEB)

    Greg Mines; Jay Nathwani; Christopher Richard; Hillary Hanson; Rachel Wood

    2015-01-01

    The capacity factors recently provided by the Energy Information Administration (EIA) indicated this plant performance metric had declined for geothermal power plants since 2008. Though capacity factor is a term commonly used by geothermal stakeholders to express the ability of a plant to produce power, it is a term frequently misunderstood and in some instances incorrectly used. In this paper we discuss how this capacity factor is defined and utilized by the EIA, including discussion on the information that the EIA requests from operations in their 923 and 860 forms that are submitted both monthly and annually by geothermal operators. A discussion is also provided regarding the entities utilizing the information in the EIA reports, and how those entities can misinterpret the data being supplied by the operators. The intent of the paper is to inform the facility operators as the importance of the accuracy of the data that they provide, and the implications of not providing the correct information.

  4. Factor XI deficiency

    Directory of Open Access Journals (Sweden)

    Jayme Diamant

    2004-06-01

    Full Text Available We describe a patient with a prolonged aPTT who was diagnosedas having factor XI deficiency after a rather large hematoma wasformed after angiography. Factor XI deficiency affects 1 in 1 millionpeople, but it is more common in Ashkenazim with a gene frequencyof 5% to 11%, being 0.3% homozygotes. These individuals usuallydo not present hemorrhagic events, except in cases of trauma orsurgery. These patients should be identified by routine coagulationscreening; bleeding could be prevented by use of fresh humanplasma or plasma concentrates.

  5. The Transcription Factor Encyclopedia

    DEFF Research Database (Denmark)

    Yusuf, Dimas; Butland, Stefanie L; Swanson, Magdalena I

    2012-01-01

    mini review articles on pertinent human, mouse and rat TFs. Notable features of the TFe website include a high-quality PDF generator and web API for programmatic data retrieval. TFe aims to rapidly educate scientists about the TFs they encounter through the delivery of succinct summaries written......ABSTRACT: Here we present the Transcription Factor Encyclopedia (TFe), a new web-based compendium of mini review articles on transcription factors (TFs) that is founded on the principles of open access and collaboration. Our consortium of over 100 researchers has collectively contributed over 130...... and vetted by experts in the field. TFe is available at http://www.cisreg.ca/tfe....

  6. Factores de riesgo : prevalencia

    OpenAIRE

    Banegas, José Ramón

    2005-01-01

    Casi la mitad de la población adulta española presenta al menos un factor de riesgo cardiovascular importante: hipertensión, tabaquismo, colesterol alto, sobrepeso, sedentarismo o diabetes, y muchos de estos individuos no lo saben, o no están tratados o no están bien controlados. Por lo tanto, mejorar el grado de conocimiento, tratamiento y control de estos factores de riesgo podría contribuir sustancialmente a reducir la magnitud de la enfermedad cardiovascular como problema de salud pública...

  7. The transcription factor encyclopedia.

    Science.gov (United States)

    Yusuf, Dimas; Butland, Stefanie L; Swanson, Magdalena I; Bolotin, Eugene; Ticoll, Amy; Cheung, Warren A; Zhang, Xiao Yu Cindy; Dickman, Christopher T D; Fulton, Debra L; Lim, Jonathan S; Schnabl, Jake M; Ramos, Oscar H P; Vasseur-Cognet, Mireille; de Leeuw, Charles N; Simpson, Elizabeth M; Ryffel, Gerhart U; Lam, Eric W-F; Kist, Ralf; Wilson, Miranda S C; Marco-Ferreres, Raquel; Brosens, Jan J; Beccari, Leonardo L; Bovolenta, Paola; Benayoun, Bérénice A; Monteiro, Lara J; Schwenen, Helma D C; Grontved, Lars; Wederell, Elizabeth; Mandrup, Susanne; Veitia, Reiner A; Chakravarthy, Harini; Hoodless, Pamela A; Mancarelli, M Michela; Torbett, Bruce E; Banham, Alison H; Reddy, Sekhar P; Cullum, Rebecca L; Liedtke, Michaela; Tschan, Mario P; Vaz, Michelle; Rizzino, Angie; Zannini, Mariastella; Frietze, Seth; Farnham, Peggy J; Eijkelenboom, Astrid; Brown, Philip J; Laperrière, David; Leprince, Dominique; de Cristofaro, Tiziana; Prince, Kelly L; Putker, Marrit; del Peso, Luis; Camenisch, Gieri; Wenger, Roland H; Mikula, Michal; Rozendaal, Marieke; Mader, Sylvie; Ostrowski, Jerzy; Rhodes, Simon J; Van Rechem, Capucine; Boulay, Gaylor; Olechnowicz, Sam W Z; Breslin, Mary B; Lan, Michael S; Nanan, Kyster K; Wegner, Michael; Hou, Juan; Mullen, Rachel D; Colvin, Stephanie C; Noy, Peter John; Webb, Carol F; Witek, Matthew E; Ferrell, Scott; Daniel, Juliet M; Park, Jason; Waldman, Scott A; Peet, Daniel J; Taggart, Michael; Jayaraman, Padma-Sheela; Karrich, Julien J; Blom, Bianca; Vesuna, Farhad; O'Geen, Henriette; Sun, Yunfu; Gronostajski, Richard M; Woodcroft, Mark W; Hough, Margaret R; Chen, Edwin; Europe-Finner, G Nicholas; Karolczak-Bayatti, Magdalena; Bailey, Jarrod; Hankinson, Oliver; Raman, Venu; LeBrun, David P; Biswal, Shyam; Harvey, Christopher J; DeBruyne, Jason P; Hogenesch, John B; Hevner, Robert F; Héligon, Christophe; Luo, Xin M; Blank, Marissa Cathleen; Millen, Kathleen Joyce; Sharlin, David S; Forrest, Douglas; Dahlman-Wright, Karin; Zhao, Chunyan; Mishima, Yuriko; Sinha, Satrajit; Chakrabarti, Rumela; Portales-Casamar, Elodie; Sladek, Frances M; Bradley, Philip H; Wasserman, Wyeth W

    2012-01-01

    Here we present the Transcription Factor Encyclopedia (TFe), a new web-based compendium of mini review articles on transcription factors (TFs) that is founded on the principles of open access and collaboration. Our consortium of over 100 researchers has collectively contributed over 130 mini review articles on pertinent human, mouse and rat TFs. Notable features of the TFe website include a high-quality PDF generator and web API for programmatic data retrieval. TFe aims to rapidly educate scientists about the TFs they encounter through the delivery of succinct summaries written and vetted by experts in the field. TFe is available at http://www.cisreg.ca/tfe.

  8. Graph factors modulo k

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2014-01-01

    We prove a general result on graph factors modulo k . A special case says that, for each natural number k , every (12k−7)-edge-connected graph with an even number of vertices contains a spanning subgraph in which each vertex has degree congruent to k modulo 2k.......We prove a general result on graph factors modulo k . A special case says that, for each natural number k , every (12k−7)-edge-connected graph with an even number of vertices contains a spanning subgraph in which each vertex has degree congruent to k modulo 2k....

  9. Factoring humans into procedures

    International Nuclear Information System (INIS)

    Luna, S.F.; Sturdivant, M.H.; McKay, R.C.

    1988-01-01

    INPO statistics on reported events in nuclear power plants rank deficient procedures as the largest single cause of human performance errors. Human factors principles used to improve the effectiveness of the control room operator can also improve the usability of written procedures. This human factors approach treats each page or complement of pages as a display. Four techniques for applying this approach are reviewed in this paper: (1) presenting information in small blocks (or fields), (2) presenting information consistently, (3) using the mental templates of the performer, and (4) matching the physical features of the plant. A final section offers examples in which combinations of these techniques are used

  10. Factor analysis and scintigraphy

    International Nuclear Information System (INIS)

    Di Paola, R.; Penel, C.; Bazin, J.P.; Berche, C.

    1976-01-01

    The goal of factor analysis is usually to achieve reduction of a large set of data, extracting essential features without previous hypothesis. Due to the development of computerized systems, the use of largest sampling, the possibility of sequential data acquisition and the increase of dynamic studies, the problem of data compression can be encountered now in routine. Thus, results obtained for compression of scintigraphic images were first presented. Then possibilities given by factor analysis for scan processing were discussed. At last, use of this analysis for multidimensional studies and specially dynamic studies were considered for compression and processing [fr

  11. STEREOTYPICAL FACTORS IN TOURISM

    Directory of Open Access Journals (Sweden)

    Cristina-Elena ALBU

    2013-06-01

    Full Text Available International tourism has grown rapidly nowdays, contributing to the growth of the global economy. The purpose of this essay is to identify and analyze stereotypical factors in the development of strategies concerning the offer for the tourism industry: the image of a tourist destination, brand, country of origin and customer behaviour. Documentary study was the research method used: representative articles were analysed, as recent as possible, to determine the factors mentioned above. Professionals in the industry of tourism need to understand cultural differences between tourists, as well as those of the host country, to be able to create tourist reception offers that live up to the standards expected by clients.

  12. Factors stimulating content marketing

    Directory of Open Access Journals (Sweden)

    Naser Azad

    2016-02-01

    Full Text Available This paper presents an empirical investigation to determine factors influencing on content marketing in banking industry. The study designs a questionnaire consists of 40 questions in Likert scale and distributes it among 550 randomly selected regular customers of Bank Mellat in city of Tehran, Iran and 400 properly filled questionnaires are collected. Cronbach alphas for all components of the survey are well above desirable level. Using principle component analysis with Varimax rotation, the study has determined six factors influencing the most on content marketing including organization, details, having new ideas, quality, sensitivity and power while the last component contains only two subcomponents and is removed from the study.

  13. Factores sociales del emprendimiento

    OpenAIRE

    Torres Martín, Francisco José

    2017-01-01

    Podemos definir el emprendimiento social como todo aquel emprendimiento que se ha creado con un fin social, con el objetivo prioritario de crear un impacto positivo en la sociedad, mediante una actividad económica. Es importante analizar los aspectos sociales que llevan a la persona adentrase al mundo empresarial, así como las consecuencias que estos les ocasionan. En el trabajo vamos estudiar en profundidad los factores sociales más importantes a la hora de emprender. Los factores sociale...

  14. Risk factors for hypospadias.

    NARCIS (Netherlands)

    Brouwers, M.M.; Feitz, W.F.J.; Roelofs, L.A.J.; Kiemeney, L.A.L.M.; Gier, R.P.E. de; Roeleveld, N.

    2007-01-01

    Despite being one of the most common congenital defects in boys, the etiology of hypospadias remains largely unknown. In this case-referent study, we evaluated a wide spectrum of potential risk factors for hypospadias. Cases were identified from the hospital information system, and referents were

  15. Human factors information system

    International Nuclear Information System (INIS)

    Goodman, P.C.; DiPalo, C.A.

    1991-01-01

    Nuclear power plant safety is dependent upon human performance related to plant operations. To provide improvements in human performance, data collection and assessment play key roles. This paper reports on the Human factors Information System (HFIS) which is designed to meet the needs of the human factors specialists of the United States Nuclear Regulatory Commission. These specialists identify personnel errors and provide guidance designed to prevent such errors. HFIS is a simple and modular system designed for use on a personal computer. It is designed to contain four separate modules that provide information indicative of program or function effectiveness as well as safety-related human performance based on programmatic and performance data. These modules include the Human Factors Status module; the Regulatory Programs module; the Licensee Event Report module; and the Operator Requalification Performance module. Information form these modules can either be used separately or can be combined due to the integrated nature of the system. HFIS has the capability, therefore, to provide insights into those areas of human factors that can reduce the probability of events caused by personnel error at nuclear power plants and promote the health and safety of the public. This information system concept can be applied to other industries as well as the nuclear industry

  16. Fano factor estimation

    Czech Academy of Sciences Publication Activity Database

    Rajdl, Kamil; Lánský, Petr

    2014-01-01

    Roč. 11, č. 1 (2014), s. 105-123 ISSN 1547-1063 R&D Projects: GA ČR(CZ) GAP103/11/0282; GA ČR(CZ) GBP304/12/G069 Institutional support: RVO:67985823 Keywords : variability * neuronal activity * information Subject RIV: JD - Computer Applications, Robotics Impact factor: 0.840, year: 2014

  17. A Formula for Factoring.

    Science.gov (United States)

    Roebuck, Kay I. Meeks

    1997-01-01

    Suggests use of the quadratic formula to build understanding that connections between factors and solutions to equations work both ways. Making use of natural connections among concepts allows students to work more efficiently. Presents four sample problems showing the roots of equations. Messy quadratic equations with rational roots can be solved…

  18. Factoring Fermat Numbers

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 1. Factoring Fermat Numbers. C E Veni Madhavan. Research News Volume 1 Issue 1 January 1996 pp 108-108. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/001/01/0108-0108. Author Affiliations.

  19. Factors affecting mining costs

    International Nuclear Information System (INIS)

    Lowell, A.F.

    1977-01-01

    The subject is discussed under the following headings: investment decision-making, unit cost factors (declining ore grade, low-price contracts, ore grade/output relationship, above average cost increases). Economic, environmental, sociological and political aspects are considered. (U.K.)

  20. Introduction to human factors

    International Nuclear Information System (INIS)

    Winters, J.M.

    1988-03-01

    Some background is given on the field of human factors. The nature of problems with current human/computer interfaces is discussed, some costs are identified, ideal attributes of graceful system interfaces are outlined, and some reasons are indicated why it's not easy to fix the problems

  1. Irrational factor races

    Indian Academy of Sciences (India)

    We investigate the behavior of the sum of the irrational factor function over arithmetic progressions. We first establish a general asymptotic formula for such a sum, and then obtain some further results in the case of arithmetic progressions 3 ± 1.

  2. Factors Impacting Knowledge Sharing

    DEFF Research Database (Denmark)

    Schulzmann, David; Slepniov, Dmitrij

    The purpose of this paper is to examine various factors affecting knowledge sharing at the R&D center of a Western MNE in China. The paper employs qualitative methodology and is based on the action research and case study research techniques. The findings of the paper advance our understanding ab...

  3. Factoring Fermat Numbers

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 1. Factoring Fermat Numbers. C E Veni Madhavan. Research News Volume 1 Issue 1 January 1996 pp 108-108. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/01/0108-0108 ...

  4. Assessment of Human Factors

    Science.gov (United States)

    Mount, Frances; Foley, Tico

    1999-01-01

    Human Factors Engineering, often referred to as Ergonomics, is a science that applies a detailed understanding of human characteristics, capabilities, and limitations to the design, evaluation, and operation of environments, tools, and systems for work and daily living. Human Factors is the investigation, design, and evaluation of equipment, techniques, procedures, facilities, and human interfaces, and encompasses all aspects of human activity from manual labor to mental processing and leisure time enjoyments. In spaceflight applications, human factors engineering seeks to: (1) ensure that a task can be accomplished, (2) maintain productivity during spaceflight, and (3) ensure the habitability of the pressurized living areas. DSO 904 served as a vehicle for the verification and elucidation of human factors principles and tools in the microgravity environment. Over six flights, twelve topics were investigated. This study documented the strengths and limitations of human operators in a complex, multifaceted, and unique environment. By focusing on the man-machine interface in space flight activities, it was determined which designs allow astronauts to be optimally productive during valuable and costly space flights. Among the most promising areas of inquiry were procedures, tools, habitat, environmental conditions, tasking, work load, flexibility, and individual control over work.

  5. PATTERNS AND FACTORS INVOLVED

    African Journals Online (AJOL)

    Between 1*' of July 1996 and 30'h of June 2000 a total of 3583 patients were registered at the accident and emergency unit of Nnamdi. Azikiwe ... The case files of these were reviewed with a view to ascertaining the causes and factors involved in the deaths of these patients. The .... H.I.V/AIDS related complications 23 6.8.

  6. Functional Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg

    2005-01-01

    \\verb+~+\\$\\backslash\\$cite{ramsay97} to functional maximum autocorrelation factors (MAF)\\verb+~+\\$\\backslash\\$cite{switzer85,larsen2001d}. We apply the method to biological shapes as well as reflectance spectra. {\\$\\backslash\\$bf Methods}. MAF seeks linear combination of the original variables that maximize autocorrelation between...

  7. Human factors in network security

    OpenAIRE

    Jones, Francis B.

    1991-01-01

    Human factors, such as ethics and education, are important factors in network information security. This thesis determines which human factors have significant influence on network security. Those factors are examined in relation to current security devices and procedures. Methods are introduced to evaluate security effectiveness by incorporating the appropriate human factors into network security controls

  8. Radiocesium bioaccumulation in freshwater plankton: Influences of cation concentrations (K{sup +} and Na{sup +}) on direct uptake of {sup 137}Cs in Chlamydomonas, Scenedesmus and Daphnia. Food-chain transfer of {sup 137}Cs from Chlamydomonas to Daphnia at different K{sup +} concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Hagstroem, J. [Uppsala Univ., Dept. of Limnology, Uppsala (Sweden)

    2002-04-01

    The influences of cation concentrations (K{sup +} and Na{sup +}) on radiocesium ({sup 137}Cs) bioaccumulation in two freshwater phytoplankton species (Scenedesmus quadricauda and Chlamydomonas noctigama) were systematically investigated in batch-cultures monitored during two weeks. Both species were cultured at 9 {mu}E M{sup -2} s{sup -1} constant illumination at 20 deg. C. The exponential growth phase lasted for more than 100 hours ({mu} {approx_equal} 0.02 h{sup -1} for C. noctigama and 0.03 h{sup -1} for S, quadricauda). Over cation concentration ranges encountered in natural fresh waters ([K{sup +}] from 0.1 {mu}M to 3 mM, [Na{sup +}] from 20 {mu}M to 3 mM), a more than three order of magnitude variation was found for both intake rate and observed bioconcentration factors (BCF) at apparent steady-state (from less than 10{sup 3} to 10{sup 6} L (kg C){sup -1}). For both species, the major effector on BCF and uptake rate was external [K{sup +}], which was inversely proportional to these parameters over wide ranges (1-1000 {mu}M for S. quadricauda and 0.1 to 300 {mu}M for C. noctigama). At concentrations above these ranges K{sup +} still reduced {sup 137} Cs bio-uptake, but less effectively. A minor influence of external [Na{sup +}] on {sup 137}Cs bioaccumulation was indicated for S. quadricauda, whereas no such influence was significant for C. noctigama. A biphasic pattern for {sup 137}Cs bioaccumulation was discovered in C. noctigama. A rapid 'quasi-steady state' with an effective equilibration time of less than 100 hours was approached during the exponential growth phase. A surge in the uptake occurred when exponential growth ceased, and this pattern was consistent over the range 30 {mu}M to 1.4 mM external [K{sup +}]. Since depletion of external [K{sup +}] was not detected for these treatments, this pattern can only be explained if there are at least two different cellular compartments involved. Although less certain, a second steady-state BCF

  9. Factors in Agile Methods Adoption

    Directory of Open Access Journals (Sweden)

    Samia Abdalhamid

    2017-05-01

    Full Text Available There are many factors that can affect the process of adopting Agile methods during software developing. This paper illustrates the critical factors in Agile methods adoption in software organizations. To present the success and failure factors, an exploratory study is carried out among the critical factors of success and failure from existing studies. Dimensions and Factors are introduced utilizing success and failure dimensions. The mind map was used to clarify these factors.

  10. On braid monodromy factorizations

    Energy Technology Data Exchange (ETDEWEB)

    Kharlamov, V M [Institut de Recherche Matematique Avanee Universite Louis Pasteur et CNRS 7 rue Rene Descartes (France); Kulikov, Vik S [Steklov Mathematical Institute, Russian Academy of Sciences (Russian Federation)

    2003-06-30

    We introduce and develop a language of semigroups over the braid groups to study the braid monodromy factorizations (bmf's) of plane algebraic curves and other related objects. As an application, we give a new proof of Orevkov's theorem on the realization of bmf's over a disc by algebraic curves and show that the complexity of such a realization cannot be bounded in terms of the types of factors of the bmf. We also prove that the type of a bmf distinguishes Hurwitz curves with singularities of inseparable type up to H-isotopy and J-holomorphic cuspidal curves in CP{sup 2} up to symplectic isotopy.

  11. Molecular factors in migraine

    OpenAIRE

    Kowalska, Marta; Prendecki, Micha?; Kozubski, Wojciech; Lianeri, Margarita; Dorszewska, Jolanta

    2016-01-01

    Migraine is a common neurological disorder that affects 11% of adults worldwide. This disease most likely has a neurovascular origin. Migraine with aura (MA) and more common form - migraine without aura (MO) ? are the two main clinical subtypes of disease. The exact pathomechanism of migraine is still unknown, but it is thought that both genetic and environmental factors are involved in this pathological process. The first genetic studies of migraine were focused on the rare subtype of MA: fa...

  12. Factors Influencing Army Maintenance

    Science.gov (United States)

    1989-01-01

    Harz (1981), reports the results of questioning largc- numbers of Subject Matter Experts (SMEs) involved in the maintenance process. The second type of...identified maintenance problems (e.g., Kokenes, 1987; Harz , 1981). The second step was the identificatl i of demand factors that affect the actual...Kokenes, 1987; Harz , 1981). Second, if any of the data on which allocations are based are faulty, or budgetary decisions require a cutback in

  13. Power factor controllers

    International Nuclear Information System (INIS)

    1982-01-01

    The power factor controller (PFC) is a solid state electronic device that reduces excessive energy waste in ac induction motors. The significance of the PFC lies in the fact that nearly a billion induction motors are used daily. The PFC is applicable to both single phase and three phase induction motors. Since it is connected to the power lines of the motor and requires no modification to the motor itself, it may be applied to existing motors as well as to new installations

  14. Factors of academic procrastination

    OpenAIRE

    Kranjec, Eva; Košir, Katja; Komidar, Luka

    2017-01-01

    This study investigated dimensions of perfectionism, anxiety, and depression as factors of academic procrastination. Our main research interest was to examine the role of specific dimensions of perfectionism as moderators in the relationship between anxiety and depression and academic procrastination. Four scales were administered on the sample of 403 students: perfectionism scale FMPS, academic procrastination scale APS-SI, depression scale CESD and anxiety scale STAI-X2. The results showed ...

  15. Bayesian Factor Analysis.

    Science.gov (United States)

    1985-03-23

    Fundamantal Factors of Comprehension in...8217’"" . " *. . . . • * • "• "". . . . " . . . . • . . # • • • . .° - -.... . ... .. . . . . . . . . ................. 1 ,,.,..,*, University of Iowa/Novick 8 March 1985 Dr. James McBride Program Manager for Manpower, Psychological...Princeton, NJ 08541 Dr. Vern W. Urry Dr. Peter Stoloff Personnel R&D Center Center for Naval Analysis Office of Personnel Management 200 North

  16. Prognostic factors for medulloblastoma

    International Nuclear Information System (INIS)

    Jenkin, Derek; Al Shabanah, Mohamed; Al Shail, Essam; Gray, Alan; Hassounah, Maher; Khafaga, Yasser; Kofide, Amani; Mustafa, Mahmoud; Schultz, Henrik

    2000-01-01

    Purpose: To evaluate prognostic factors for medulloblastoma. Methods and Materials: One hundred and seventy-three consecutive patients with medulloblastoma, treated at King Faisal Specialist Hospital (KFSH) from 1988-1997, were reviewed. Eighty-four percent were children less than 15 years old. From 1988-1994, treatment was at the discretion of the investigator. From 1994-1998, patients entered a single-arm best practice protocol in which, in staged patients, the surgical intent was total resection, standard radiation treatment was defined, and adjuvant chemotherapy was given to a 'high-risk' subset. Results: For 150 patients who completed surgical and radiation treatment, the 5-year survival rate was 58%, compared with 0% for 16 patients who were unable to start or complete radiation treatment. For staged patients, the 5-year survival was M0 + M1, 78% and M2 + M3, 21% (p 14 years and gross cystic/necrotic features in the primary tumor. The size of the primary tumor, the degree of hydrocephalus at diagnosis, the presence of residual tumor in the post-operative CT/MRI, and the functional status of the patient prior to radiation treatment were not significant factors. Conclusions: Stage M0 + M1 was the most powerful favorable prognostic factor. In Saudi Arabia more patients present with advanced disseminated disease, 41% M2 + M3, than in the West, and this impacts adversely on overall survival. Total resection and standard radiation treatment were not sensitive prognostic factors in a treatment environment in which 78% of patients underwent at least 90% tumor resection and 60% received standard radiation treatment. In order to improve the proportion of patients able to complete radiation treatment, consideration should be given to limiting resection when the attainment of total resection is likely to be morbid, and to delaying rather than omitting radiation treatment in the patient severely compromised postoperatively

  17. Eukaryotic transcription factors

    DEFF Research Database (Denmark)

    Staby, Lasse; O'Shea, Charlotte; Willemoës, Martin

    2017-01-01

    Gene-specific transcription factors (TFs) are key regulatory components of signaling pathways, controlling, for example, cell growth, development, and stress responses. Their biological functions are determined by their molecular structures, as exemplified by their structured DNA-binding domains...... them to participate in large interactomes, how they use only a few hydrophobic residues, short sequence motifs, prestructured motifs, and coupled folding and binding for their interactions with co-activators, and how their accessibility to post-translational modification affects their interactions...

  18. Power Factor Controller

    Science.gov (United States)

    1997-01-01

    Frank Nola invented the Power Factor Controller (PFC) at Marshall Space Flight Center more than a decade ago. Nola came up with a way to curb power wastage in AC induction motors. The PFC matches voltage with the motor's actual need by continuously sensing shifts between voltage and current. When it senses a light load it cuts the voltage to the minimum needed. Potential energy savings range from 8 to 65 percent.

  19. Risk factors for cancer

    International Nuclear Information System (INIS)

    Lyman, G.H.

    1992-01-01

    It is no longer reasonable to divide cancers into those that are genetic in origin and those that are environmental in origin. With rare exception, carcinogenesis involves environmental factors that directly or indirectly exert a change in the cell's genome. Virtually all causes of cancer are multifactorial, sometimes involving an inherited predisposition to the carcinogenic effects of environmental factors, which include chemicals, ionizing radiation, and oncogenic virus. Carcinogenesis is a multistep process including induction, promotion, and progression. Initiation requires an irreversible change in the cellular genome, whereas promotion is commonly associated with prolonged and reversible exposure. Tumor progression results in genotypic and phenotypic changes associated with tumor growth, invasion, and metastasis. Most information on human cancer risk is based on epidemiologic studies involving both exposed and unexposed individuals. The quality of such studies depends on their ability to assess the strength of any association of exposure and disease and careful attention to any potential bias. Few cancers are inherited in a Mendelian fashion. Several preneoplastic conditions, however, are clearly inherited and several malignancies demonstrate weak familial patterns. Environmental factors may exert their effect on DNA in a random fashion, but certain consistent changes, including specific translocations of genetic information, are often found. Currently, there is great interest in the close proximity of certain oncogenes governing growth control to the consistent chromosomal changes observed. Such changes may represent a final common pathway of action for environmental carcinogens. Sufficient laboratory and epidemiologic evidence exists to establish a causal association of several chemical agents with cancer

  20. Human Factors Review Plan

    International Nuclear Information System (INIS)

    Paramore, B.; Peterson, L.R.

    1985-12-01

    ''Human Factors'' is concerned with the incorporation of human user considerations into a system in order to maximize human reliability and reduce errors. This Review Plan is intended to assist in the assessment of human factors conditions in existing DOE facilities. In addition to specifying assessment methodologies, the plan describes techniques for improving conditions which are found to not adequately support reliable human performance. The following topics are addressed: (1) selection of areas for review describes techniques for needs assessment to assist in selecting and prioritizing areas for review; (2) human factors engineering review is concerned with optimizing the interfaces between people and equipment and people and their work environment; (3) procedures review evaluates completeness and accuracy of procedures, as well as their usability and management; (4) organizational interface review is concerned with communication and coordination between all levels of an organization; and (5) training review evaluates training program criteria such as those involving: trainee selection, qualification of training staff, content and conduct of training, requalification training, and program management

  1. Human Factors Review Plan

    Energy Technology Data Exchange (ETDEWEB)

    Paramore, B.; Peterson, L.R. (eds.)

    1985-12-01

    ''Human Factors'' is concerned with the incorporation of human user considerations into a system in order to maximize human reliability and reduce errors. This Review Plan is intended to assist in the assessment of human factors conditions in existing DOE facilities. In addition to specifying assessment methodologies, the plan describes techniques for improving conditions which are found to not adequately support reliable human performance. The following topics are addressed: (1) selection of areas for review describes techniques for needs assessment to assist in selecting and prioritizing areas for review; (2) human factors engineering review is concerned with optimizing the interfaces between people and equipment and people and their work environment; (3) procedures review evaluates completeness and accuracy of procedures, as well as their usability and management; (4) organizational interface review is concerned with communication and coordination between all levels of an organization; and (5) training review evaluates training program criteria such as those involving: trainee selection, qualification of training staff, content and conduct of training, requalification training, and program management.

  2. Molecular factors in migraine

    Science.gov (United States)

    Kowalska, Marta; Prendecki, Michał; Kozubski, Wojciech; Lianeri, Margarita; Dorszewska, Jolanta

    2016-01-01

    Migraine is a common neurological disorder that affects 11% of adults worldwide. This disease most likely has a neurovascular origin. Migraine with aura (MA) and more common form - migraine without aura (MO) – are the two main clinical subtypes of disease. The exact pathomechanism of migraine is still unknown, but it is thought that both genetic and environmental factors are involved in this pathological process. The first genetic studies of migraine were focused on the rare subtype of MA: familial hemiplegic migraine (FHM). The genes analysed in familial and sporadic migraine are: MTHFR, KCNK18, HCRTR1, SLC6A4, STX1A, GRIA1 and GRIA3. It is possible that migraine is a multifactorial disease with polygenic influence. Recent studies have shown that the pathomechanisms of migraine involves both factors responsible for immune response and oxidative stress such as: cytokines, tyrosine metabolism, homocysteine; and factors associated with pain transmission and emotions e.g.: serotonin, hypocretin-1, calcitonin gene-related peptide, glutamate. The correlations between genetic variants of the HCRTR1 gene, the polymorphism 5-HTTLPR and hypocretin-1, and serotonin were observed. It is known that serotonin inhibits the activity of hypocretin neurons and may affect the appearance of the aura during migraine attack. The understanding of the molecular mechanisms of migraine, including genotype-phenotype correlations, may contribute to finding markers important for the diagnosis and treatment of this disease. PMID:27191890

  3. Human and Organizational Factors

    International Nuclear Information System (INIS)

    Eshiett, P.B.S.

    2016-01-01

    The Human and Organizational Factors Approach to Industrial Safety (HOFS) consists of identifying and putting in place conditions which encourage a positive contribution from operators (individually and in a team) with regards to industrial safety. The knowledge offered by the HOFS approach makes it possible better to understand what conditions human activity and to act on the design of occupational situations and the organization, in the aim of creating the conditions for safe work. Efforts made in this area can also lead to an improvement in results in terms of the quality of production or occupational safety (incidence and seriousness rates) (Daniellou, F., et al., 2011). Research on industrial accidents shows that they rarely happen as a result of a single event, but rather emerge from the accumulation of several, often seemingly trivial, malfunctions, misunderstandings, incorrect assumptions and other issues. The nuclear community has established rigorous international safety standards and concepts to ensure the protection of people and the environment from harmful effects of ionizing radiation (IAEA, 2014). A review of major human induced disasters in a number of countries and in different industries yields insights into several of the human and organizational factors involved in their occurrence. Some of these factors relate to failures in: • Design or technology; • Training; • Decision making; • Communication; • Preparation for the unexpected; • Understanding of organizational interdependencies

  4. Human factoring administrative procedures

    International Nuclear Information System (INIS)

    Grider, D.A.; Sturdivant, M.H.

    1991-01-01

    In nonnuclear business, administrative procedures bring to mind such mundane topics as filing correspondence and scheduling vacation time. In the nuclear industry, on the other hand, administrative procedures play a vital role in assuring the safe operation of a facility. For some time now, industry focus has been on improving technical procedures. Significant efforts are under way to produce technical procedure requires that a validated technical, regulatory, and administrative basis be developed and that the technical process be established for each procedure. Producing usable technical procedures requires that procedure presentation be engineered to the same human factors principles used in control room design. The vital safety role of administrative procedures requires that they be just as sound, just a rigorously formulated, and documented as technical procedures. Procedure programs at the Tennessee Valley Authority and at Boston Edison's Pilgrim Station demonstrate that human factors engineering techniques can be applied effectively to technical procedures. With a few modifications, those same techniques can be used to produce more effective administrative procedures. Efforts are under way at the US Department of Energy Nuclear Weapons Complex and at some utilities (Boston Edison, for instance) to apply human factors engineering to administrative procedures: The techniques being adapted include the following

  5. The focus factor

    DEFF Research Database (Denmark)

    Nicolaisen, Jeppe; Frandsen, Tove Faber

    2015-01-01

    Introduction. We present a new bibliometric indicator to measure journal specialisation over time, named the focus factor. This new indicator is based on bibliographic coupling and counts the percentage of re-citations given in subsequent years. Method. The applicability of the new indicator is d...... on either simple citation analysis or bibliographic coupling are found to be close relatives. Measures based on journal self-citation are found to be only weakly correlated with the focus factor. Measures based on co-citation analysis remain to be studied and compared.......Introduction. We present a new bibliometric indicator to measure journal specialisation over time, named the focus factor. This new indicator is based on bibliographic coupling and counts the percentage of re-citations given in subsequent years. Method. The applicability of the new indicator...... is demonstrated on a selection of general science journals and on a selection of medical journals. The reference lists of each journal are compared year by year, and the percentage of re-citations is calculated by dividing the number of re-citations with the total number of citations each year. Analysis...

  6. Observed and modeled effects of pH on bioconcentration of diphenhydramine, a weakly basic pharmaceutical, by fathead minnows

    Science.gov (United States)

    Understanding the influence of pH on uptake and accumulation of ionizable pharmaceuticals by fish was recently identified as a major research need. In the present study, fathead minnows were exposed to diphenhydramine (DPH), a weakly basic pharmaceutical (pKa = 9.1). Fish were ...

  7. Including Bioconcentration Kinetics for the Prioritization and Interpretation of Regulatory Aquatic Toxicity Tests of Highly Hydrophobic Chemicals

    DEFF Research Database (Denmark)

    Kwon, Jung-Hwan; Lee, So-Young; Kang, Hyun-Joong

    2016-01-01

    Worldwide, regulations of chemicals require short-term toxicity data for evaluating hazards and risks of the chemicals. Current data requirements on the registration of chemicals are primarily based on tonnage and do not yet consider properties of chemicals. For example, short-term ecotoxicity data...

  8. Bioconcentration of triclosan, methyl-triclosan, and triclocarban in the plants and sediments of a constructed wetland.

    Science.gov (United States)

    Zarate, Frederick M; Schulwitz, Sarah E; Stevens, Kevin J; Venables, Barney J

    2012-07-01

    Constructed wetlands are a potential method for the removal of two pharmaceutical and personal care products from wastewater effluent. Triclosan (TCS; 5-chloro-2-[2,4-dichlorophenoxy]phenol) and triclocarban (TCC; 3,4,4'-trichlorocarbanillide) are antimicrobial agents added to a variety of consumer products whose accumulation patterns in constructed wetlands are poorly understood. Here, we report the accumulation of TCS, its metabolite methyl-triclosan (MTCS; 5-chloro-2-[2,4-dichlorophenoxy]), and TCC in wetland plant tissues and sediments. Three wetland macrophytes: Typha latifolia, Pontederia cordata, and Sagittaria graminea were sampled from a constructed wetland in Denton, Texas, USA. MTCS concentrations were below the method detection limit (MDL) for all species. TCS root tissue concentrations in T. latifolia were significantly greater than root concentrations in P. cordata (mean±SE in ng g(-1): 40.3±11.3 vs. 15.0±1.9, respectively), while for TCC, shoot tissue concentrations in S. graminea were significantly greater than in T. latifolia (22.8±9.3 vs. 9.0 (MDL), respectively). For both TCS and TCC, T. latifolia root tissue concentrations were significantly greater than shoot concentrations (TCS: 40.3±11.3 vs. 17.2±0.2, TCC: 26.0±3.6 vs. 9.0, (MDL)). TCC concentrations in P. cordata roots were significantly greater than in shoots (34.4±5.3 vs. 15.4±2.8, respectively). TCS concentrations in T. latifolia roots and sediments and TCC concentrations in sediments generally decreased from wetland inflow to outflow. To our knowledge, this is the first study documenting species and tissue specific differences in the accumulation of TCS and TCC in plants from an operational constructed wetland. The species specific differences in bioaccumulation suggest TCS and TCC removal from constructed wetlands could be enhanced through targeted plantings. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Prevalence, Variability and Bioconcentration of Saxitoxin-Group in Different Marine Species Present in the Food Chain.

    Science.gov (United States)

    Oyaneder Terrazas, Javiera; Contreras, Héctor R; García, Carlos

    2017-06-12

    The saxitoxin-group (STX-group) corresponds to toxic metabolites produced by cyanobacteria and dinoflagellates of the genera Alexandrium, Gymnodinium , and Pyrodinium . Over the last decade, it has been possible to extrapolate the areas contaminated with the STX-group worldwide, including Chile, a phenomenon that has affected ≈35% of the Southern Pacific coast territory, generating a high economic impact. The objective of this research was to study the toxicity of the STX-group in all aquatic organisms (bivalves, algae, echinoderms, crustaceans, tunicates, cephalopods, gastropods, and fish) present in areas with a variable presence of harmful algal blooms (HABs). Then, the toxic profiles of each species and dose of STX equivalents ingested by a 60 kg person from 400 g of shellfish were determined to establish the health risk assessment. The toxins with the highest prevalence detected were gonyautoxin-4/1 (GTX4/GTX1), gonyautoxin-3/2 (GTX3/GTX2), neosaxitoxin (neoSTX), decarbamoylsaxitoxin (dcSTX), and saxitoxin (STX), with average concentrations of 400, 2800, 280, 200, and 2000 µg kg -1 respectively, a species-specific variability, dependent on the evaluated tissue, which demonstrates the biotransformation of the analogues in the trophic transfer with a predominance of α-epimers in all toxic profiles. The identification in multiple vectors, as well as in unregulated species, suggests that a risk assessment and risk management update are required; also, chemical and specific analyses for the detection of all analogues associated with the STX-group need to be established.

  10. Prevalence, Variability and Bioconcentration of Saxitoxin-Group in Different Marine Species Present in the Food Chain

    Directory of Open Access Journals (Sweden)

    Javiera Oyaneder Terrazas

    2017-06-01

    Full Text Available The saxitoxin-group (STX-group corresponds to toxic metabolites produced by cyanobacteria and dinoflagellates of the genera Alexandrium, Gymnodinium, and Pyrodinium. Over the last decade, it has been possible to extrapolate the areas contaminated with the STX-group worldwide, including Chile, a phenomenon that has affected ≈35% of the Southern Pacific coast territory, generating a high economic impact. The objective of this research was to study the toxicity of the STX-group in all aquatic organisms (bivalves, algae, echinoderms, crustaceans, tunicates, cephalopods, gastropods, and fish present in areas with a variable presence of harmful algal blooms (HABs. Then, the toxic profiles of each species and dose of STX equivalents ingested by a 60 kg person from 400 g of shellfish were determined to establish the health risk assessment. The toxins with the highest prevalence detected were gonyautoxin-4/1 (GTX4/GTX1, gonyautoxin-3/2 (GTX3/GTX2, neosaxitoxin (neoSTX, decarbamoylsaxitoxin (dcSTX, and saxitoxin (STX, with average concentrations of 400, 2800, 280, 200, and 2000 µg kg−1 respectively, a species-specific variability, dependent on the evaluated tissue, which demonstrates the biotransformation of the analogues in the trophic transfer with a predominance of α-epimers in all toxic profiles. The identification in multiple vectors, as well as in unregulated species, suggests that a risk assessment and risk management update are required; also, chemical and specific analyses for the detection of all analogues associated with the STX-group need to be established.

  11. Bioconcentration, metabolism and neurotoxicity of the organophorous flame retardant 1,3-dichloro 2-propyl phosphate (TDCPP) to zebrafish.

    Science.gov (United States)

    Wang, Qiangwei; Lam, James Chung-Wah; Man, Yin-Chung; Lai, Nelson Lok-Shun; Kwok, Karen Ying; Guo, Yong yong; Lam, Paul Kwan-Sing; Zhou, Bingsheng

    2015-01-01

    Organophosphate flame retardants are ubiquitous environmental contaminants; however, knowledge is limited regarding their environmental health risks and toxicity. Here, we investigated the effects of acute and long-term exposure to tris(1,3-dichloro-2-propyl) phosphate (TDCPP) to the nervous system of zebrafish. Zebrafish embryos (2 h post-fertilization) were exposed to TDCPP (0-100 μg/L) for 6 months up until sexual maturation. Concentrations of TDCPP and its metabolic product (bis(1,3-dichloro-2-propyl) phosphate, BDCPP) were measured in the tissues of 5 day post-fertilization (dpf) larvae. There was no effect on locomotion, acetylcholinesterase activity, levels of the neurotransmitters dopamine and serotonin, and expression of mRNAs and proteins related to central nervous system development (e.g., myelin basic protein, α1-tubulin) in any exposure group. However, in adult fish, reductions of dopamine and serotonin levels were detected in the brains of females but not males. Downregulation of nervous system development genes was observed in both the male and female brain tissues. TDCPP concentrations were measured in adult fish tissues including the brain, and greater levels were detected in females. Our results showed that females are more sensitive to TDCPP stress than males in terms of TDCPP-induced neurotoxicity. We demonstrate that long-term exposure to lower concentrations of TDCPP in fish can lead to neurotoxicity. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Bioconcentration of some macrominerals in soil, forage and buffalo hair continuum: A case study on pasture irrigated with sewage water.

    Science.gov (United States)

    Khan, Zafar Iqbal; Ahmad, Kafeel; Ashraf, Iqra; Gondal, Sumaira; Sher, Muhammad; Hayat, Zafar; Laudadio, Vito; Tufarelli, Vincenzo

    2015-05-01

    The present study aimed to evaluate the bioaccumulation of some macrominerals in grazing buffaloes fed forage irrigated with sewage water or canal water. In particular, the transfer of sodium (Na), magnesium (Mg), potassium (K) and calcium (Ca) from soil to plant and in turn to animals was evaluated under sub-tropical environmental conditions. Samples of soil, forage and buffalo hair were collected and digested by wet method. Sodium and K concentrations were significantly higher in the soil but lower in the forages; however, Mg and Ca concentrations in both soil and forages were higher. The correlation between soil, forage and hair showed an imbalanced flow of Na, Mg and K and a balanced flow of Ca from soil to forage and then to animals. Based on the findings, the highest rates of transfer of minerals were found for sewage water treatment, whereas lowest rates were found for canal water treatment, except for Na. As the transfer of minerals depends on their bioavailability, the highest values may be due to the high rates of mineral uptake by plants. Thus, the high transfer rate of some elements by plants could become toxic in future causing detrimental effect to grazing livestock.

  13. -Bioactive factors in milk-.

    Science.gov (United States)

    Buts, J P

    1998-03-01

    Human milk as well as the milk of several mammalian species contains, beside major nutrients and anti-infectious and immunocompetent substances, a group of biologically active substances called "milk-borne trophic factors" or "growth modulators". Milk-borne trophic can be classified into three groups: hormones and trophic peptides; nucleotides, nucleosides and derived substances; and polyamines, especially spermine and spermidine. Certain hormones and peptides such as growth hormone, insulin, insulin like-growth factor I (IGF-I), epidermal growth factor (EGF), prolactin and growth hormone releasing factor (GHRF) can influence directly newborn's metabolism after intestinal absorption and promote growth and differentiation of several organs and target tissues. They could exert a cytoprotective effect against toxins and toxic substances and reduce the potential risk of necrotizing enterocolitis. Nucleotides are present in human milk at high levels, and are precursors of nucleic acids, which implies that they can enhance growth and differentiation of several organs and tissues, especially the liver. Nucleotides from milk enhance lipid metabolism, lipoprotein synthesis and liver cell function and regeneration. In addition, they have a determinant action on the development of the gut associated lymphoid tissue (GALT). Lastly, polyamines, mainly spermine and spermidine, are polycationic substances virtually present in all cells, whose concentration in human milk is about ten times higher than in infant formulae. In addition, spermine and spermidine levels increase markedly during the first 3 days of lactation reaching, after 1 week, plateau levels which are respectively 12 and eight times higher than the levels measured at day 0. Although several experimental studies have shown that polyamines from the milk of lactating mammals determine important mitogenic, metabolic and immunological effects promoting growth and differentiation of the immature gastrointestinal tract of

  14. Cross-culturally recurrent personality factors : Analyses of three factors

    NARCIS (Netherlands)

    De Raad, B.; Peabody, D

    This study proceeds from an earlier one that examined the 'Big Five' factors (Peabody & De Raad, 2002). That study considered the substantive nature of five factors from six European psycholexical studies. The results supported Big Five Factor III (Conscientiousness), but Factors I (Extraversion)

  15. Milestones and Impact Factors

    Directory of Open Access Journals (Sweden)

    Grandjean Philippe

    2010-07-01

    Full Text Available Abstract Environmental Health has just received its first Impact Factor by Thomson ISI. At a level of 2.48, this achievement is quite satisfactory and places Environmental Health in the top 25% of environmental science journals. When the journal was launched in 2002, it was still unclear whether the Open Access publishing model could be made into a viable commercial enterprise within the biomedical field. During the past eight years, Open Access journals have become widely available, although still covering only about 15% of journal titles. Major funding agencies and institutions, including prominent US universities, now require that researchers publish in Open Access journals. Because of the profound role of scientific journals for the sharing of results and communication between researchers, the advent of Open Access may be of as much significance as the transition from handwriting to printing via moveable type. As Environmental Health is an electronic Open Access journal, the numbers of downloads at the journal website can be retrieved. The top-20 list of articles most frequently accessed shows that all of them have been downloaded over 10,000 times. Back in 2002, the first article published was accessed only 49 times during the following month. A year later, the server had over 1,000 downloads per month, and now the total number of monthly downloads approaches 50,000. These statistics complement the Impact Factor and confirm the viability of Open Access in our field of research. The advent of digital media and its decentralized mode of distribution - the internet - have dramatically changed the control and financing of scientific information dissemination, while facilitating peer review, accelerating editorial handling, and supporting much needed transparency. Both the meaning and means of "having an impact" are therefore changing, as will the degree and way in which scientific journals remain "factors" in that impact.

  16. Factor 4 planning

    International Nuclear Information System (INIS)

    Bariol-Mathais, Brigitte; Lavoillotte, Philippine; Gall-Sorrentino, Florence; Malez, Marianne; Sanna, Daniela; Marsauche, Maud; Marquet, Sarah; Debergue, Sophie; Aminu, Olufunmi; Bernard, Helene; Marchand, Jean-Michel; Blin, Frederic; Grange, Jerome; Caillierez, Sophie; Muller, Dania; Clement, Bob; Desire, Jean-Charles; Metais, Benedicte; Lannuzel, Philippe; Pezet-Kuhn, Murielle; Pons, Anne; Rivoire-Meley, Benedicte; Tissot, Heloise

    2015-07-01

    Factor 4 is the goal of cutting our greenhouse gas emissions by 75% by 2050. Achieving this objective will necessitate radical changes in our practices, in particular concerning transport and housing; the measures currently implemented, such as positive-energy buildings, low-impact mobility and eco-neighbourhoods, will not be enough to meet this goal. These measures must be conceived in the framework of broad territorial planning that integrates environmental and energy objectives far upstream. To this end, the French Environment and Energy Management Agency (ADEME) and the French network of Urban Planning Agencies (FNAU), pursuing their missions in their respective areas of competence, have joined forces to make infrastructure and land use planning an integral part of the environmental and energy transition process. In 2013, the two organisations signed a partnership agreement and compiled an inventory of practices that are relevant to Factor 4 planning. This work was led by Epures, Saint-etienne urban planning agency, along with FNAU, drawing upon the expertise of a dozen urban planning agencies in precursor territories. This inventory describes the stakes, resources and strengths for each territory, which have led to cross-sectoral territorial planning exercises with ambitious environmental and energy objectives; the importance of evaluation in attaining these goals is emphasised. Current experience, questions and available methodological tools are summarised in this document, to encourage territories and help them design their planning policies along a trajectory to achieve Factor 4 goals. The compilation also aims to be a contribution to the COP21 climate conference

  17. Improved Balanced Incomplete Factorization

    Czech Academy of Sciences Publication Activity Database

    Bru, R.; Marín, J.; Mas, J.; Tůma, Miroslav

    2010-01-01

    Roč. 31, č. 5 (2010), s. 2431-2452 ISSN 0895-4798 R&D Projects: GA AV ČR IAA100300802 Grant - others:GA AV ČR(CZ) M100300902 Institutional research plan: CEZ:AV0Z10300504 Source of funding: I - inštitucionálna podpora na rozvoj VO Keywords : preconditioned iterative methods * sparse matrices * incomplete decompositions * approximate inverses * Sherman-Morrison formula * nonsymmetric matrices Subject RIV: BA - General Mathematics Impact factor: 1.725, year: 2010

  18. Accidents and human factors

    International Nuclear Information System (INIS)

    Nishiwaki, Y.; Kawai, H.; Morishima, H.; Terano, T.; Sugeno, M.

    1984-01-01

    When the TMI accident occurred it was 4 a.m., an hour when the error potential of the operators would have been very high. The frequency of car and train accidents in Japan is also highest between 4 a.m. and 6 a.m. The error potential may be classified into five phases corresponding to the electroencephalogramic pattern (EEG). At phase 0, when the delta wave appears, a person is unconscious and in deep sleep; at phase I, when the theta wave appears, he is very tired, sleepy and subnormal; at phase II, when the alpha wave appears, he is normal, relaxed and passive; at phase III, when the beta wave appears, he is normal, clear-minded and active; at phase IV, when the strong beta or epileptic wave appears, he is hypernormal, excited and incapable of normal judgement. Should an accident occur at phase II, the brain condition may jump to phase IV. At this phase the error or accident potential is maximum. The response of the human brain to different types of noises and signals may vary somewhat for different individuals and for different groups of people. Therefore, the possibility that such differences in brain functions may influence the mental structure would be worthy of consideration in human factors and in the design of man-machine systems. Human reliability and performance would be affected by many factors: medical, physiological and psychological, etc. The uncertainty involved in human factors may not necessarily be probabilistic, but fuzzy. Therefore, it would be important to develop a theory by which both non-probabilistic uncertainties, or fuzziness, of human factors and the probabilistic properties of machines can be treated consistently. From the mathematical point of view, probabilistic measure is considered a special case of fuzzy measure. Therefore, fuzzy set theory seems to be an effective tool for analysing man-machine systems. To minimize human error and the possibility of accidents, new safety systems should not only back up man and make up for his

  19. Perinatal risk factors for strabismus

    DEFF Research Database (Denmark)

    Torp-Pedersen, Tobias; Boyd, Heather A; Poulsen, Gry

    2010-01-01

    Little is known about the aetiological factors underlying strabismus. We undertook a large cohort study to investigate perinatal risk factors for strabismus, overall and by subtype.......Little is known about the aetiological factors underlying strabismus. We undertook a large cohort study to investigate perinatal risk factors for strabismus, overall and by subtype....

  20. Risk Factors for Eating Disorders

    Science.gov (United States)

    Striegel-Moore, Ruth H.; Bulik, Cynthia M.

    2007-01-01

    The authors review research on risk factors for eating disorders, restricting their focus to studies in which clear precedence of the hypothesized risk factor over onset of the disorder is established. They illustrate how studies of sociocultural risk factors and biological factors have progressed on parallel tracks and propose that major advances…

  1. Activation of human factor V by factor Xa and thrombin

    International Nuclear Information System (INIS)

    Monkovic, D.D.; Tracy, P.B.

    1990-01-01

    The activation of human factor V by factor Xa and thrombin was studied by functional assessment of cofactor activity and sodium dodecyl sulfate-polycarylamide gel electrophoresis followed by either autoradiography of 125 I-labeled factor V activation products or Western blot analyses of unlabeled factor V activation products. Cofactor activity was measured by the ability of the factor V/Va peptides to support the activation of prothrombin. The factor Xa catalyzed cleavage of factor V was observed to be time, phospholipid, and calcium ion dependent, yielding a cofactor with activity equal to that of thrombin-activated factor V (factor Va). The cleavage pattern differed markedly from the one observed in the bovine system. The factor Xa activated factor V subunits expressing cofactor activity were isolated and found to consist of peptides of M r 220,000 and 105,000. Although thrombin cleaved the M r 220,000 peptide to yield peptides previously shown to be products of thrombin activation, cofactor activity did not increase. N-Terminal sequence analysis confirmed that both factor Xa and thrombin cleave factor V at the same bond to generate the M r 220,000 peptide. The factor Xa dependent functional assessment of 125 I-labeled factor V coupled with densitometric analyses of the cleavage products indicated that the cofactor activity of factor Xa activated factor V closely paralleled the appearance of the M r 220,000 peptide. The data indicate that factor Xa is as efficient an enzyme toward factor V as thrombin

  2. Organizational factors in Korean NPPs

    International Nuclear Information System (INIS)

    Jang, D. J.; Kim, Y. I.; Jeong, C. H.; Kim, J. W.

    2003-01-01

    Organizational factors are referred to as the factors that influence the achievement of a goal of an organization. Latent problems of an organization could contribute to causing human errors in such stages as design, operation and maintenance, and furthermore, leading to an severe accident. In order to evaluate an organization from the safety viewpoint, it is necessary to identify the organizational factors in a systematic fashion. In this paper, some efforts to identify the organizational factors in Korean NPPs are presented. The study was performed in the following steps: 1) Reviewing the definitions and range of the organizational factors used by the previous 13 researches, 2) Structuring the organizational factors by screening and collating factors, 3) Analysing the organizational factors that is considered to have contributed to the trip events based on the trip report of Korean NPPs, 4) Suggesting a more reliable taxonomy of organizational factors for event analysis by applying the Onion Structure Model to the selected factors

  3. Risk Factors in Pemphigus

    Directory of Open Access Journals (Sweden)

    Gülşen Tükenmez Demirc

    2011-09-01

    Full Text Available Background and Design: There have been reports suggesting the involvement of environmental factors in the disease process of pemphigus. In this study, we aimed to find out the risk factors which could play role in the etiopathogenesis in our pemphigus patients.Material and method: A total of 42 patients (15 male and 27 female who were diagnosed as pemphigus with histopathological and direct immunoflurosence examinations in our clinic between the years 1998-2004, were interviewed for assessment of regarding with the subjects of the demographic properties, occupational groups, educational level, the number of pregnancies, stressfull life events, diet habits, smoking and alcohol consumption before the onset of the disease and the results were compared to 42 age and gender-matched controls with similar socioeconomic circumstances. Results: Working in agriculture and livestock, multi-parity, absence of smoking and stressfull life events were found to be statistically significant in pemphigus patients than in controls. Conclusion: Working in agriculture and livestock, multi-parity, absence of smoking and stressfull life events were assumed to play role in the etiopathogenesis and course of pemphigus.

  4. Eclipse telescope design factors

    Science.gov (United States)

    Hull, Tony; Trauger, John T.; Macenka, Steven A.; Moody, Dwight; Olarte, Guillermo; Sepulveda, Cesar; Tsuha, Walter; Cohen, David

    2003-02-01

    Very high contrast imagery, required for exoplanet image acquisition, imposes significantly different criteria upon telescope architecture than do the requirements imposed upon most spaceborne telescopes. For the Eclipse Mission, the fundamental figure-of-merit is a stellar contrast, or brightness reduction ratio, reaching a factor of 10-9 or better at star-planet distances as close as the 4th Airy ring. Factors necessary to achieve such contrast ratios are both irrelevant and largely ignored in contemporary telescope design. Although contemporary telescoeps now meet Hubble Space Telescope performance at substantially lower mass and cost than HST, control of mid-spatial-frequency (MSF) errors, crucial to coronagraphy, has not been emphasized. Accordingly, roughness at MSF has advanced little since HST. Fortunately, HST primary mirror smoothness would nearly satisfy Eclipse requirements, although other aspects of HST are undesirable for stellar coronagraphy. Conversely, the narrow field required for Eclipse eases other drivers of traditional telescope design. A systematic approach to telescope definition, with primary and sub-tier figures-of-merit, will be discussed in the context of the Eclipse Mission.

  5. Pion form factor

    Energy Technology Data Exchange (ETDEWEB)

    Ryong Ji, C.; Pang, A.; Szczepaniak, A. [North Carolina State Univ., Raleigh, NC (United States)

    1994-04-01

    It is pointed out that the correct criterion to define the legal PQCD contribution to the exclusive processes in the lightcone perturbative expansion should be based on the large off-shellness of the lightcone energy in the intermediate states. In the lightcone perturbative QCD calculation of the pion form factor, the authors find that the legal PQCD contribution defined by the lightcone energy cut saturates in the smaller Q{sup 2} region compared to that defined by the gluon four-momentum square cut. This is due to the contribution by the highly off-energy-shell gluons in the end point regions of the phase space, indicating that the gluon four-momentum-square cut may have cut too much to define the legal PQCD.

  6. Psychosomatic factors in pruritus.

    Science.gov (United States)

    Tey, Hong Liang; Wallengren, Joanna; Yosipovitch, Gil

    2013-01-01

    Pruritus and psyche are intricately and reciprocally related, with psychophysiological evidence and psychopathological explanations helping us to understand their complex association. Their interaction may be conceptualized and classified into 3 groups: pruritic diseases with psychiatric sequelae, pruritic diseases aggravated by psychosocial factors, and psychiatric disorders causing pruritus. Management of chronic pruritus is directed at treating the underlying causes and adopting a multidisciplinary approach to address the dermatologic, somatosensory, cognitive, and emotional aspects. Pharmcotherapeutic agents that are useful for chronic pruritus with comorbid depression and/or anxiety comprise selective serotonin reuptake inhibitors, mirtazapine, tricyclic antidepressants (amitriptyline and doxepin), and anticonvulsants (gabapentin, pregabalin); the role of neurokinin receptor-1 antagonists awaits verification. Antipsychotics are required for treating itch and formication associated with schizophrenia and delusion of parasitosis (including Morgellons disease). Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Factorization of Observables

    Science.gov (United States)

    Eliaš, Peter; Frič, Roman

    2017-12-01

    Categorical approach to probability leads to better understanding of basic notions and constructions in generalized (fuzzy, operational, quantum) probability, where observables—dual notions to generalized random variables (statistical maps)—play a major role. First, to avoid inconsistencies, we introduce three categories L, S, and P, the objects and morphisms of which correspond to basic notions of fuzzy probability theory and operational probability theory, and describe their relationships. To illustrate the advantages of categorical approach, we show that two categorical constructions involving observables (related to the representation of generalized random variables via products, or smearing of sharp observables, respectively) can be described as factorizing a morphism into composition of two morphisms having desired properties. We close with a remark concerning products.

  8. Perioperative allergy: risk factors.

    Science.gov (United States)

    Caffarelli, C; Stringari, G; Pajno, G B; Peroni, D G; Franceschini, F; Dello Iacono, I; Bernardini, R

    2011-01-01

    Perioperative anaphylactic as well as anaphylactoid reactions can be elicited by drugs, diagnostic agents, antiseptics, disinfectants and latex. In some individuals, allergic reactions occur in the absence of any evident risk factor. Previous history of specific safe exposure to a product does not permit to exclude the risk of having a reaction. We have systematically reviewed characteristics in the patient's history or clinical parameters that affect the risk of developing reactions during anesthesia. Evidence shows that patients with previous unexplained reaction during anesthesia are at risk for perioperative allergic reactions. An allergic reaction to an agent is associated with previous reaction to a product that is related with the culprit agent. Multiple surgery procedures, professional exposure to latex and allergy to fruit are associated with an increased frequency of latex allergy. It has been shown that in some instances, allergic perioperative reactions may be more common in atopic patients and in females.

  9. Unity power factor converter

    Science.gov (United States)

    Wester, Gene W. (Inventor)

    1980-01-01

    A unity power factor converter capable of effecting either inversion (dc-to-dc) or rectification (ac-to-dc), and capable of providing bilateral power control from a DC source (or load) through an AC transmission line to a DC load (or source) for power flow in either direction, is comprised of comparators for comparing the AC current i with an AC signal i.sub.ref (or its phase inversion) derived from the AC ports to generate control signals to operate a switch control circuit for high speed switching to shape the AC current waveform to a sine waveform, and synchronize it in phase and frequency with the AC voltage at the AC ports, by selectively switching the connections to a series inductor as required to increase or decrease the current i.

  10. Nucleon Electromagnetic Form Factors

    Energy Technology Data Exchange (ETDEWEB)

    Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi

    2007-10-01

    There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has greatly improved by performing double polarization experiments, in comparison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at JLab, MAMI, and MIT-Bates. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed, including the recent progress in the determination of the valence quark generalized parton distributions of the nucleon, as well as the steady rate of improvements made in the lattice QCD calculations.

  11. Neutron quality factor

    International Nuclear Information System (INIS)

    1995-06-01

    Both the International Commission on Radiological Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP) have recommended that the radiation quality weighting factor for neutrons (Q n , or the corresponding new modifying factor, w R ) be increased by a value of two for most radiation protection practices. This means an increase in the recommended value for Q n from a nominal value of 10 to a nominal value of 20. This increase may be interpreted to mean that the biological effectiveness of neutrons is two times greater than previously thought. A decision to increase the value of Q n will have a major impact on the regulations and radiation protection programs of Federal agencies responsible for the protection of radiation workers. Therefore, the purposes of this report are: (1) to examine the general concept of open-quotes quality factorclose quotes (Q) in radiation protection and the rationale for the selection of specific values of Q n ; and (2) to make such recommendations to the Federal agencies, as appropriate. This report is not intended to be an exhaustive review of the scientific literature on the biological effects of neutrons, with the aim of defending a particular value for Q n . Rather, the working group examined the technical issues surrounding the current recommendations of scientific advisory bodies on this matter, with the aim of determining if these recommendations should be adopted by the Federal agencies. Ultimately, the group concluded that there was no compelling basis for a change in Q n . The report was prepared by Federal scientists working under the auspices of the Science Panel of the Committee on Interagency Radiation Research and Policy Coordination (CIRRPC)

  12. Factorization with Gauss sums: scaling properties of ghost factors

    International Nuclear Information System (INIS)

    Stefanak, M; Merkel, W; Schleich, W P; Haase, D; Maier, H

    2007-01-01

    Recent experiments have shown that truncated Gauss sums allow us to find the factors of an integer N. This method relies on the fact that for a factor the absolute value of the Gauss sum is unity. However, for every integer N there exist integers which are not factors, but where the Gauss sum reaches a value which is arbitrarily close to unity. In order to distinguish such ghost factors from real factors we need to amplify this difference. We show that a proper choice of the truncation parameter of the Gauss sum suppresses the ghost factors below a threshold value. We derive the scaling law of the truncation parameter on the number to be factored. Moreover, we show that this scaling law is also necessary for the success of our factorization scheme, even if we relax the threshold or allow limited error tolerance

  13. Identifying the important factors in simulation models with many factors

    NARCIS (Netherlands)

    Bettonvil, B.; Kleijnen, J.P.C.

    1994-01-01

    Simulation models may have many parameters and input variables (together called factors), while only a few factors are really important (parsimony principle). For such models this paper presents an effective and efficient screening technique to identify and estimate those important factors. The

  14. Conditions for factor (in)determinacy in factor analysis

    NARCIS (Netherlands)

    Krijnen, W.P.; Dijkstra, T.K.; Gill, R.D.

    1998-01-01

    The subject of factor indeterminacy has a vast history in factor analysis Wilson Lederman Guttman It has lead to strong dierences in opinion Steiger The current paper gives necessary and sucient conditions for observability of factors in terms of the parameter matrices and a nite number of

  15. Conditions for factor (in)determinacy in factor analysis

    NARCIS (Netherlands)

    Krijnen, W.P.; Dijkstra, T.K.; Gill, R.D.

    1998-01-01

    The subject of factor indeterminacy has a vast history in factor analysis (Guttman, 1955; Lederman, 1938; Wilson, 1928). It has lead to strong differences in opinion (Steiger, 1979). The current paper gives necessary and sufficient conditions for observability of factors in terms of the parameter

  16. Factor Rotation and Standard Errors in Exploratory Factor Analysis

    Science.gov (United States)

    Zhang, Guangjian; Preacher, Kristopher J.

    2015-01-01

    In this article, we report a surprising phenomenon: Oblique CF-varimax and oblique CF-quartimax rotation produced similar point estimates for rotated factor loadings and factor correlations but different standard error estimates in an empirical example. Influences of factor rotation on asymptotic standard errors are investigated using a numerical…

  17. External Factors, Internal Factors and Self-Directed Learning Readiness

    Science.gov (United States)

    Ramli, Nurjannah; Muljono, Pudji; Afendi, Farit M.

    2018-01-01

    There are many factors which affect the level of self-directed learning readiness. This study aims to investigate the relationship between external factors, internal factors and self-directed learning readiness. This study was carried out by using a census method for fourth year students of medical program of Tadulako University. Data were…

  18. Air Emissions Factors and Quantification

    Science.gov (United States)

    Emissions factors are used in developing air emissions inventories for air quality management decisions and in developing emissions control strategies. This area provides technical information on and support for the use of emissions factors.

  19. What Are the Risk Factors?

    Science.gov (United States)

    ... Stay Informed Cancer Home What Are the Risk Factors for Lung Cancer? Language: English (US) Español (Spanish) ... your cell phone Research has found several risk factors that may increase your chances of getting lung ...

  20. R-Factor for Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The rainfall-runoff erosivity factor (R-Factor) quantifies the effects of raindrop impacts and reflects the amount and rate of runoff associated with the rain. The...

  1. Self-shielding factors

    International Nuclear Information System (INIS)

    Kaul, D.C.

    1982-01-01

    Throughout the last two decades many efforts have been made to estimate the effect of body self-shielding on organ doses from externally incident neutrons and gamma rays. These began with the use of simple geometry phantoms and have culminated in the use of detailed anthropomorphic phantoms. In a recent effort, adjoint Monte Carlo analysis techniques have been used to determine dose and dose equivalent to the active marrow as a function of energy and angle of neutron fluence externally incident on an anthropomorphic phantom. When combined with fluences from actual nuclear devices, these dose-to-fluence factors result in marrow dose values that demonstrate great sensitivity to variations in device type, range, and body orientation. Under a state-of-the-art radiation transport analysis demonstration program for the Japanese cities, sponsored by the Defense Nuclear Agency at the request of the National Council on Radiation Protection and Measurements, the marrow dose study referred to above is being repeated to obtain spectral distributions within the marrow for externally incident neutrons and gamma rays of arbitrary energy and angle. This is intended to allow radiobiologists and epidemiologists to select and to modify numbers of merit for correlation with health effects and to permit a greater understanding of the relationship between human and laboratory subject dosimetry

  2. Factor XII Contact Activation.

    Science.gov (United States)

    Naudin, Clément; Burillo, Elena; Blankenberg, Stefan; Butler, Lynn; Renné, Thomas

    2017-11-01

    Contact activation is the surface-induced conversion of factor XII (FXII) zymogen to the serine protease FXIIa. Blood-circulating FXII binds to negatively charged surfaces and this contact to surfaces triggers a conformational change in the zymogen inducing autoactivation. Several surfaces that have the capacity for initiating FXII contact activation have been identified, including misfolded protein aggregates, collagen, nucleic acids, and platelet and microbial polyphosphate. Activated FXII initiates the proinflammatory kallikrein-kinin system and the intrinsic coagulation pathway, leading to formation of bradykinin and thrombin, respectively. FXII contact activation is well characterized in vitro and provides the mechanistic basis for the diagnostic clotting assay, activated partial thromboplastin time. However, only in the past decade has the critical role of FXII contact activation in pathological thrombosis been appreciated. While defective FXII contact activation provides thromboprotection, excess activation underlies the swelling disorder hereditary angioedema type III. This review provides an overview of the molecular basis of FXII contact activation and FXII contact activation-associated disease states. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  3. Research organizational factors

    International Nuclear Information System (INIS)

    Coffman, F.D. Jr.

    1990-01-01

    Organizational processes at nuclear power plants should be sufficient to prevent accidents and to protect public health and safety upon the occurrence of an accident. The role of regulatory research is to confirm that agency assessments of organization processes are on a firm technical basis and provide for improvements in the NRC [Nuclear Regulatory Commission] programs. A firm technical basis is achieved by reducing uncertainties associated with methods and measures used to assess organization processes. The general objective for regulatory research is to confirm that the agency has a coherent understanding of the organizational processes that are individually necessary and are collectively sufficient for safe operations, methods are available to reliably characterize organizational processes, and measures exist to monitor changes in the key organizational processes. The first specific objective was to develop a method to translate organizational processes into PRAs. The discussion provides feedback and insights from experience with the past and the ongoing organizational factors research. That experience suggests a set of ingredients that appear proper for performing regulatory research on organizational processes. By keeping focused upon these proper ingredients, the research will contribute to the regulatory assessments of utility management through the use of improved methods and measures in investigations, inspections, diagnostics, performance indicators, and PRA insights

  4. Investing in systematic factor premiums

    NARCIS (Netherlands)

    Koedijk, C.G.; Slager, A.M.H.; Stork, P.A.

    2016-01-01

    In this paper we investigate and evaluate factor investing in the US and Europe for equities and bonds. We show that factor-based portfolios generally produce comparable or better portfolios than market indices. We expand the analysis to other asset classes and factors, work with other optimisation

  5. Human Factors in Marine Casualties

    Directory of Open Access Journals (Sweden)

    Jelenko Švetak

    2002-05-01

    Full Text Available Human factors play an important role in the origin of accidents,and it is commonly claimed that between seventy andninety-five percent of industrial and transport accidents involvehuman factors, see Figure 1.Some authorities, however, claim that ultimately, all accidentsinvolve human factors.

  6. Investing in systematic factor premiums

    NARCIS (Netherlands)

    Koedijk, Kees G.; Slager, Alfred M. H.; Stork, P.A.

    In this paper we investigate and evaluate factor investing in the US and Europe for equities and bonds. We show that factor-based portfolios generally produce comparable or better portfolios than market indices. We expand the analysis to other asset classes and factors, work with other optimisation

  7. Factor Analysis of Intern Effectiveness

    Science.gov (United States)

    Womack, Sid T.; Hannah, Shellie Louise; Bell, Columbus David

    2012-01-01

    Four factors in teaching intern effectiveness, as measured by a Praxis III-similar instrument, were found among observational data of teaching interns during the 2010 spring semester. Those factors were lesson planning, teacher/student reflection, fairness & safe environment, and professionalism/efficacy. This factor analysis was as much of a…

  8. Factor analysis and missing data

    NARCIS (Netherlands)

    Kamakura, WA; Wedel, M

    2000-01-01

    The authors study the estimation of factor models and the imputation of missing data and propose an approach that provides direct estimates of factor weights without the replacement of missing data with imputed values. First, the approach is useful in applications of factor analysis in the presence

  9. Factor Analysis via Components Analysis

    Science.gov (United States)

    Bentler, Peter M.; de Leeuw, Jan

    2011-01-01

    When the factor analysis model holds, component loadings are linear combinations of factor loadings, and vice versa. This interrelation permits us to define new optimization criteria and estimation methods for exploratory factor analysis. Although this article is primarily conceptual in nature, an illustrative example and a small simulation show…

  10. Robust and Sparse Factor Modelling

    DEFF Research Database (Denmark)

    Croux, Christophe; Exterkate, Peter

    nonzero factor loadings. Compared to the traditional factor construction method, we find that this procedure leads to a favorable forecasting performance in the presence of outliers and to better interpretable factors. We investigate the performance of the method in a Monte Carlo experiment...

  11. Evaluation of cadmium bioaccumulation and translocation by Hopea ...

    African Journals Online (AJOL)

    parisa

    2012-04-10

    Apr 10, 2012 ... species selected as phytoremediator, three indicators were used namely, bioconcentration factor (BCF, the metal concentration ratio of plant roots to soil), translocation factor (TF, the metal concentration ratio of plant shoots to ... centration of Cd in soil ranges from 0.01 to 2.0 mg kg-1; however, in urban and ...

  12. Geriatic Disability Related Factors

    Directory of Open Access Journals (Sweden)

    Mohsen Adib Hajbagheri

    2008-07-01

    Full Text Available Objectives: Reports are indicating of increasing trend of aging and disability in the developing countries while such disabilities are decreasing within the developed countries. This study designed to evaluate the disability and some of its related factors among the elderly population (65 and older in Kashan, Iran. Methods & Materials: A cross-sectional analytical study was conducted on a multi-stage random sample of 350 elderly people (65 year and older in Kashan. The WHO-DAS-II was used as the generic disability measure. The questionnair had 48 questions. The range of score could be between 0-144. Chi-square, t-test analysis and ANOVA were utilized to check significant differences between subgroups. Results: 61% were men and 12% were living lonely. One fourth had some type of addiction, the majority were ilitrate and two thired had not regular phisycal activity.Twenty percent of the old people had a modereate disability and 4.3% were extremely disabled. A significant relationship was found between the disability and variables such as sex, age, living style, needing help, marriage status, living location, addiction, job, level of physical activity, education, and having multiple diseases. Conclusion: In conclusion, geriatric population in Iran, has a lower levels of disability in compare to those of other developed countries. Need of geriatric cares must be be increasing, since the populationpattern of elderly people is increasing in Iran. Female and ilitrate elders were sufering of more disability. These findings indicated the nessesity to more attention to these voulnarable subgroups of population.

  13. Gut transfer factors

    International Nuclear Information System (INIS)

    1990-01-01

    A Nuclear Energy Agency (NEA) Expert Group has proposed values for the absorbed fractions (f 1 values) of radionuclides ingested in food and drinking water by members of the public. The f 1 values for adults, which are also taken to apply to children from 1 year of age, are increased from those given in ICRP Publication 30 for occupationally exposed adults for 7 elements out of the 31 considered. Since the publication of the NEA report, further information has become available that is relevant to the choice of f 1 values for polonium and thorium. These data suggest that for the present the f 1 value for polonium currently recommended by ICRP (0.1) should be retained, and that for thorium a reasonable f 1 value is 0.0005. With these exceptions, the NRPB endorses the revisions in f 1 values proposed by the NEA Expert Group for adults and children from 1 year of age. Higher f 1 values are proposed by the NEA expert Group for absorption in the first year of life. For adult values of between 0.01 and 0.5, an increase by a factor of two is assumed, and for adult values of 0.001 or less, absorption by infants is taken to be ten times greater. This approach is consistent with, and extends, that applied to the actinides in ICRP Publication 48 and represents a reasonable interpretation of current evidence. The NRPB therefore endorses the approach proposed by the NEA Expert Group for the calculation of doses to infants. (author)

  14. [Recurrent diverticulitis - risk factors].

    Science.gov (United States)

    Adamová, Z; Slováček, R; Sankot, J

    2013-10-01

    Colonic diverticular disease is a common illness, especially in the elderly population. It may be asymptomatic and cause chronic intestinal problems, colonic diverticular bleeding or inflammatory complications with considerable morbidity and mortality. We have attempted at finding factors that would help us identify patients with a higher risk of diverticulitis recurrence as well as patients with a higher likelihood of perforated diverticulitis. This retrospective study included all patients admitted to our surgical ward for inflammatory complications of diverticular disease between 2000 and 2012: 278 patients, 88 men and 190 women. We looked up the first attack of diverticulitis in our documentation as well as the relapses, if any, their number and course, and the time from the first attack to the relapse. We analyzed the influence of age, gender, comorbidities (diabetes mellitus, overweight, ischemic heart disease, chronic renal failure, gastroduodenal disease), nicotine abuse and medication (glucocorticoids and other immunosuppressive drugs, acetylsalicylic acid) on diverticulitis recurrence and its complicated course. We compared the results of conservative and surgical therapy. Statistical analysis was performed using Fishers exact test and Man-Whitney U tests. We did not demonstrate any statistically significant dependence of diverticulitis recurrence on age or gender. Colectomy (both acute and elective surgery) clearly decreases the likelihood of recurrence (p=0.00007). Comorbidities, nicotine abuse and medication were not associated with an increased risk of recurrence. Steroid and immunosuppressive drugs use was significantly associated with higher perforation rates, without impacting on the likelihood of recurrence. Regular smoking of cigarettes had no impact on recurrence or on its severity. We did not find any reliable indicator of recurrent diverticulitis. Age, gender, comorbidities, smoking and medication are not significant. Immunocompromised

  15. The population factor.

    Science.gov (United States)

    Kats, G

    1983-01-01

    Reducing population growth is essentil to Egypt's broader efforts to improve facilities, services, and the phsycial quality of life. Although a family planning program has existed since the mid-1950s, the 2.7% annual rate of population growth has not changed in 30 years. Nasser and the other "free officers" who seized power in 1952 became concerned about the adverse effects of the rapidly growing population, but perhaps out of concern with a possible religious backlash, they confined themselves to launching studies and subsidizing several dozen private family planning clinics. From 1962-72, the number of private clinics grew from 28 to 480, and family planning was introduced in government healthclinics in 1965. Such clinics are mainly located in rural areas and are staffed by doctors and other personnel who are not members of the local community and are not very effective at promoting family planning. Local girls and women called Rayadet were recruited to promote the idea to birth control in local communities. By 1970, 12.6% of Egyptians were using reliable contraception. A national survey 12 years later found 34% using contraception, buth the figure seems high. Approximately 60-65% of eligible couples would need to practice birth control for Egypt to reach a less than 1% annuel increase. The Egyptian government hopes to slow population growth to 1% by the year 2000, but major problems of motivation remain especially among the rural poor. Several factors may lead to success of the family planning effort: 1) financial and technical support from international family planning sources has grown rapidley and is likely to remain high; 2) the mortality rate has dropped from 17.8/1000 in 1952 to about half that level, while the rate of natural increase is about the same, suggesting that future reductions in the birth rate will translate to a reduced rate of natural increase, and that parents will be less reluctant to practice faimly planning if there is a greater chance

  16. A factor analysis to detect factors influencing building national brand

    Directory of Open Access Journals (Sweden)

    Naser Azad

    Full Text Available Developing a national brand is one of the most important issues for development of a brand. In this study, we present factor analysis to detect the most important factors in building a national brand. The proposed study uses factor analysis to extract the most influencing factors and the sample size has been chosen from two major auto makers in Iran called Iran Khodro and Saipa. The questionnaire was designed in Likert scale and distributed among 235 experts. Cronbach alpha is calculated as 84%, which is well above the minimum desirable limit of 0.70. The implementation of factor analysis provides six factors including “cultural image of customers”, “exciting characteristics”, “competitive pricing strategies”, “perception image” and “previous perceptions”.

  17. Risk factor based investing:case: MSCI risk factor indices

    OpenAIRE

    Pieskä, J. (Jukka)

    2016-01-01

    Abstract The aim of this thesis is to study risk factor based investing and test how well MSCI constructs their risk factor based indices. Risk factor based investing has gained a lot of media exposure in the recent years and “Smart Beta” products are becoming more popular. Blackrock estimated that there are more than 700 exchange traded products available and they have over $ 529 billion in assets under management. Risk fa...

  18. Harmony of super form factors

    Science.gov (United States)

    Brandhuber, A.; Gürdoğan, Ö.; Mooney, R.; Travaglini, G.; Yang, G.

    2011-10-01

    In this paper we continue our systematic study of form factors of half-BPS operators in mathcal{N} = 4 super Yang-Mills. In particular, we extend various on-shell techniques known for amplitudes to the case of form factors, including MHV rules, recursion relations, unitarity and dual MHV rules. As an application, we present the solution of the recursion relation for split-helicity form factors. We then consider form factors of the stress-tensor multiplet operator and of its chiral truncation, and write down supersymmetric Ward identities using chiral as well as non-chiral superspace formalisms. This allows us to obtain compact formulae for families of form factors, such as the maximally non-MHV case. Finally we generalise dual MHV rules in dual momentum space to form factors.

  19. Investing in Systematic Factor Premiums

    OpenAIRE

    Koedijk, Kees; Slager, Alfred; Stork, Philip

    2015-01-01

    In this paper we investigate and evaluate factor investing in the United States and Europe for equities and bonds. We show that factor-based portfolios generally produce comparable or better portfolios than market indices. We expand the analysis to other asset classes and factors, work with other optimization methods and add a basic liability structure. The results remain robust when we add real estate and commodities to equities and bonds. Also, the results are not dependent to the removal o...

  20. Risk factors in school shootings.

    Science.gov (United States)

    Verlinden, S; Hersen, M; Thomas, J

    2000-01-01

    Nine incidents of multiple-victim homicide in American secondary schools are examined and common risk factors are identified. The literature dealing with individual, family, social, societal, and situational risk factors for youth violence and aggression is reviewed along with existing risk assessment methods. Checklists of risk factors for serious youth violence and school violence are used in reviewing each school shooting case. Commonalties among the cases and implications for psychologists practicing in clinical and school settings are discussed.

  1. Social networks and factor markets

    DEFF Research Database (Denmark)

    Abay, Kibrom Araya; Kahsay, Goytom Abraha; Berhane, Guush

    In the absence of well-established factor markets, the role of indigenous institutions and social networks can be substantial for mobilizing factors for agricultural production. We investigate the role of an indigenous social network in Ethiopia, the iddir, in facilitating factor market...... transactions among smallholder farmers. Using detailed longitudinal household survey data and employing a difference-in-differences approach, we find that iddir membership improves households’ access to factor markets. Specifically, we find that joining an iddir network improves households’ access to land...... sources. These results point out the roles non-market arrangements, such as social networks, can play in mitigating market inefficiencies in poor rural markets....

  2. Strange nucleon form-factors

    Science.gov (United States)

    Maas, F. E.; Paschke, K. D.

    2017-07-01

    A broad program measuring parity-violation in electron-nuclear scattering has now provided a large set of precision data on the weak-neutral-current form-factors of the proton. Under comparison with well-measured electromagnetic nucleon form-factors, these measurements reveal the role of the strange quark sea on the low-energy interactions of the proton through the strange-quark-flavor vector form-factors. This review will describe the experimental program and the implications of the global data for the strange-quark vector form-factors. We present here a new fit to the world data.

  3. Factorization method of quadratic template

    Science.gov (United States)

    Kotyrba, Martin

    2017-07-01

    Multiplication of two numbers is a one-way function in mathematics. Any attempt to distribute the outcome to its roots is called factorization. There are many methods such as Fermat's factorization, Dixońs method or quadratic sieve and GNFS, which use sophisticated techniques fast factorization. All the above methods use the same basic formula differing only in its use. This article discusses a newly designed factorization method. Effective implementation of this method in programs is not important, it only represents and clearly defines its properties.

  4. Gene regulation by growth factors

    International Nuclear Information System (INIS)

    Metz, R.; Gorham, J.; Siegfried, Z.; Leonard, D.; Gizang-Ginsberg, E.; Thompson, M.A.; Lawe, D.; Kouzarides, T.; Vosatka, R.; MacGregor, D.; Jamal, S.; Greenberg, M.E.; Ziff, E.B.

    1988-01-01

    To coordinate the proliferation and differentiation of diverse cell types, cells of higher eukaryotes communicate through the release of growth factors. These peptides interact with specific transmembrane receptors of other cells and thereby generate intracellular messengers. The many changes in cellular physiology and activity that can be induced by growth factors imply that growth factor-induced signals can reach the nucleus and control gene activity. Moreover, current evidence also suggests that unregulated signaling along such pathways can induce aberrant proliferation and the formation of tumors. This paper reviews investigations of growth factor regulation of gene expression conducted by the authors' laboratory

  5. Summable series and convergence factors

    CERN Document Server

    Moore, Charles N

    1938-01-01

    Fairly early in the development of the theory of summability of divergent series, the concept of convergence factors was recognized as of fundamental importance in the subject. One of the pioneers in this field was C. N. Moore, the author of the book under review.... Moore classifies convergence factors into two types. In type I he places the factors which have only the property that they preserve convergence for a convergent series or produce convergence for a summable series. In type II he places the factors which not only maintain or produce convergence but have the additional property that

  6. First course in factor analysis

    CERN Document Server

    Comrey, Andrew L

    2013-01-01

    The goal of this book is to foster a basic understanding of factor analytic techniques so that readers can use them in their own research and critically evaluate their use by other researchers. Both the underlying theory and correct application are emphasized. The theory is presented through the mathematical basis of the most common factor analytic models and several methods used in factor analysis. On the application side, considerable attention is given to the extraction problem, the rotation problem, and the interpretation of factor analytic results. Hence, readers are given a background of

  7. FACTORING- CREDIT OPPORTUNITIES IN ROMANIA

    Directory of Open Access Journals (Sweden)

    ADELA IONESCU

    2013-05-01

    Full Text Available Capital is the main factor of production, business development becomes virtually impossible without taking into account the financial market and the resources it provides to businesses. Any business, regardless of its degree of development, is involving direct contact with financial markets, namely the institutions that mediate mobilization of capital and the services they provide. Understanding the functioning of the financial system, the specific financial mechanisms through which savings are allocated to support capital investments and the costs and risks involved is essential for the development of a solid base for business. In this context, factoring operations can support economic agents, allowing a transfer of commercial receivables from their holder to a factor who commits to their recovery and guarantee such operations even if temporary or permanent insolvency of the debtor . Thus, factoring is a complex technique in at least two aspects, of the debt and the transfer of credit. . Factoring is a means of financing business, especially export-import transactions, less known in Romania. Maybe because of poor business environment popularize the term is as little known as it was a few years ago the leasing. Present in Romanian legislation since 2002, factoring appears as a contract between one party (called adherent, providing goods or service and a banking company or a financial institution specialized (called factor, which the last one shall finance debts pursuing and preservation against credit risks and adherent gives factor by way of sale, debts arising from the sale of goods or services to third parties. The article is divided into three parts. In the first part we defined the concept of factoring and international factoring, then I presented the advantages and development of factoring in Romania, and the last part conclusions.

  8. Pineal factors other than melatonin

    NARCIS (Netherlands)

    Ebels, I.

    Some sheep pineal factors other than melatonin are described. A “nonmelatonin” antigonadotropic activity has been detected by application of the inhibition of compensatory ovarian hypertrophy (COH) in unilaterally ovariectomized adult Charles River CD-1 mice. The factor has been extracted from

  9. Kadison-Kastler stable factors

    DEFF Research Database (Denmark)

    Cameron, Jan; Christensen, Erik; Sinclair, Allan M.

    2014-01-01

    It is proven that a pair of continuous finite von Neumann algebra factors are unitarily equivalent if sufficiently close and one satisfies a certain cohomological condition.......It is proven that a pair of continuous finite von Neumann algebra factors are unitarily equivalent if sufficiently close and one satisfies a certain cohomological condition....

  10. Quadratic prediction of factor scores

    NARCIS (Netherlands)

    Wansbeek, T

    1999-01-01

    Factor scores are naturally predicted by means of their conditional expectation given the indicators y. Under normality this expectation is linear in y but in general it is an unknown function of y. II is discussed that under nonnormality factor scores can be more precisely predicted by a quadratic

  11. Prevalence and obstetric risk factors

    African Journals Online (AJOL)

    suggest that obstetric factors increase the risk of damage to the anal sphincter and subsequent development of AI.[4-6] These ... variations may impact on obstetric risk factors and AI prevalence. We therefore performed a study in our population, which .... Regulatory approvals. Institutional and hospital ethical approval were ...

  12. Factors That Shape Design Thinking

    Science.gov (United States)

    Gray, Colin M.

    2013-01-01

    A wide range of design literature discusses the role of the studio and its related pedagogy in the development of design thinking. Scholars in a variety of design disciplines pose a number of factors that potentially affect this development process, but a full understanding of these factors as experienced from a critical pedagogy or student…

  13. Factor analysis of multivariate data

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, A.A.; Mahadevan, R

    A brief introduction to factor analysis is presented. A FORTRAN program, which can perform the Q-mode and R-mode factor analysis and the singular value decomposition of a given data matrix is presented in Appendix B. This computer program, uses...

  14. Human factors influencing decision making

    OpenAIRE

    Jacobs, Patricia A.

    1998-01-01

    This report supplies references and comments on literature that identifies human factors influencing decision making, particularly military decision making. The literature has been classified as follows (the classes are not mutually exclusive): features of human information processing; decision making models which are not mathematical models but rather are descriptive; non- personality factors influencing decision making; national characteristics influencing decision makin...

  15. The nucleon's strange form factors

    International Nuclear Information System (INIS)

    Pitt, Mark L.

    2000-01-01

    Knowledge of the nucleon's strange form factors will provide valuable insight into low energy hadron structure. Measurement of the vector strange form factor of the nucleon is accomplished through parity-violating electron scattering. This paper reviews the current status of this class of experiments

  16. Factors of trade in Europe

    Czech Academy of Sciences Publication Activity Database

    Hanousek, Jan; Kočenda, Evžen

    2014-01-01

    Roč. 38, č. 4 (2014), s. 518-535 ISSN 0939-3625 R&D Projects: GA ČR(CZ) GAP403/12/0080 Grant - others:UK(CZ) UNCE 204005/2012 Institutional support: PRVOUK-P23 Keywords : bilateral trade * factors of trade * panel data Subject RIV: AH - Economics Impact factor: 0.649, year: 2014

  17. Twisting formula of epsilon factors

    Indian Academy of Sciences (India)

    For characters of a non-Archimedean local field we have explicit formula for epsilon factors. But in general, we do not have any generalized twisting formula of epsilon factors. In this paper, we give a generalized twisting formula of epsilon factorsvia local Jacobi sums.

  18. Mitotic bookmarking by transcription factors.

    Science.gov (United States)

    Kadauke, Stephan; Blobel, Gerd A

    2013-04-02

    Mitosis is accompanied by dramatic changes in chromatin organization and nuclear architecture. Transcription halts globally and most sequence-specific transcription factors and co-factors are ejected from mitotic chromatin. How then does the cell maintain its transcriptional identity throughout the cell division cycle? It has become clear that not all traces of active transcription and gene repression are erased within mitotic chromatin. Many histone modifications are stable or only partially diminished throughout mitosis. In addition, some sequence-specific DNA binding factors have emerged that remain bound to select sites within mitotic chromatin, raising the possibility that they function to transmit regulatory information through the transcriptionally silent mitotic phase, a concept that has been termed "mitotic bookmarking." Here we review recent approaches to studying potential bookmarking factors with regards to their mitotic partitioning, and summarize emerging ideas concerning the in vivo functions of mitotically bound nuclear factors.

  19. Physiological enhancement of factors in factor analysis of dynamic studies

    International Nuclear Information System (INIS)

    Samal, M.; Surova, H.; Marikova, E.; Michalova, K.; Karny, M.; Dienstbier, Z.

    1986-01-01

    Factor analysis of dynamic radionuclide studies provides their decomposition into the images and time-activity curves corresponding to the underlying dynamic structures. The method is based on the analysis of study variance and on the subsequent differential imaging of its principal components into a simplified factor space. By changing the amount and the composition of the variance processed in the analysis it is possible to enhance the factors that are important for diagnosis while the less important factors can be suppressed. In our report, a short theoretical review of the problem is given and illustrated by the analysis of dynamic cholescintigraphy. It is shown that a suitable choice of region and/or the temporal interval of interest enables the differential evaluation of such intrahepatic compartments, which could not be observed without enhancement. (orig.)

  20. Corrosion effects on friction factors

    International Nuclear Information System (INIS)

    Magleby, H.L.; Shaffer, S.J.

    1996-01-01

    This paper presents the results of NRC-sponsored material specimen tests that were performed to determine if corrosion increases the friction factors of sliding surfaces of motor-operated gate valves, which could require higher forces to close and open safety-related valves when subjected to their design basis differential pressures. Friction tests were performed with uncorroded specimens and specimens subjected to accelerated corrosion. Preliminary tests at ambient conditions showed that corrosion increased the friction factors, indicating the need for additional tests duplicating valve operating parameters at hot conditions. The additional tests showed friction factors of corroded specimens were 0.1 to 0.2 higher than for uncorroded specimens, and that the friction factors of the corroded specimens were not very dependent on contact stress or corrosion film thickness. The measured values of friction factors for the three corrosion films tested (simulating three operating times) were in the range of 0.3 to 0.4. The friction factor for even the shortest simulated operating time was essentially the same as the others, indicating that the friction factors appear to reach a plateau and that the plateau is reached quickly

  1. Conversion factors and oil statistics

    International Nuclear Information System (INIS)

    Karbuz, Sohbet

    2004-01-01

    World oil statistics, in scope and accuracy, are often far from perfect. They can easily lead to misguided conclusions regarding the state of market fundamentals. Without proper attention directed at statistic caveats, the ensuing interpretation of oil market data opens the door to unnecessary volatility, and can distort perception of market fundamentals. Among the numerous caveats associated with the compilation of oil statistics, conversion factors, used to produce aggregated data, play a significant role. Interestingly enough, little attention is paid to conversion factors, i.e. to the relation between different units of measurement for oil. Additionally, the underlying information regarding the choice of a specific factor when trying to produce measurements of aggregated data remains scant. The aim of this paper is to shed some light on the impact of conversion factors for two commonly encountered issues, mass to volume equivalencies (barrels to tonnes) and for broad energy measures encountered in world oil statistics. This paper will seek to demonstrate how inappropriate and misused conversion factors can yield wildly varying results and ultimately distort oil statistics. Examples will show that while discrepancies in commonly used conversion factors may seem trivial, their impact on the assessment of a world oil balance is far from negligible. A unified and harmonised convention for conversion factors is necessary to achieve accurate comparisons and aggregate oil statistics for the benefit of both end-users and policy makers

  2. Sequence Factorization with Multiple References.

    Science.gov (United States)

    Wandelt, Sebastian; Leser, Ulf

    2015-01-01

    The success of high-throughput sequencing has lead to an increasing number of projects which sequence large populations of a species. Storage and analysis of sequence data is a key challenge in these projects, because of the sheer size of the datasets. Compression is one simple technology to deal with this challenge. Referential factorization and compression schemes, which store only the differences between input sequence and a reference sequence, gained lots of interest in this field. Highly-similar sequences, e.g., Human genomes, can be compressed with a compression ratio of 1,000:1 and more, up to two orders of magnitude better than with standard compression techniques. Recently, it was shown that the compression against multiple references from the same species can boost the compression ratio up to 4,000:1. However, a detailed analysis of using multiple references is lacking, e.g., for main memory consumption and optimality. In this paper, we describe one key technique for the referential compression against multiple references: The factorization of sequences. Based on the notion of an optimal factorization, we propose optimization heuristics and identify parameter settings which greatly influence 1) the size of the factorization, 2) the time for factorization, and 3) the required amount of main memory. We evaluate a total of 30 setups with a varying number of references on data from three different species. Our results show a wide range of factorization sizes (optimal to an overhead of up to 300%), factorization speed (0.01 MB/s to more than 600 MB/s), and main memory usage (few dozen MB to dozens of GB). Based on our evaluation, we identify the best configurations for common use cases. Our evaluation shows that multi-reference factorization is much better than single-reference factorization.

  3. Sequence Factorization with Multiple References.

    Directory of Open Access Journals (Sweden)

    Sebastian Wandelt

    Full Text Available The success of high-throughput sequencing has lead to an increasing number of projects which sequence large populations of a species. Storage and analysis of sequence data is a key challenge in these projects, because of the sheer size of the datasets. Compression is one simple technology to deal with this challenge. Referential factorization and compression schemes, which store only the differences between input sequence and a reference sequence, gained lots of interest in this field. Highly-similar sequences, e.g., Human genomes, can be compressed with a compression ratio of 1,000:1 and more, up to two orders of magnitude better than with standard compression techniques. Recently, it was shown that the compression against multiple references from the same species can boost the compression ratio up to 4,000:1. However, a detailed analysis of using multiple references is lacking, e.g., for main memory consumption and optimality. In this paper, we describe one key technique for the referential compression against multiple references: The factorization of sequences. Based on the notion of an optimal factorization, we propose optimization heuristics and identify parameter settings which greatly influence 1 the size of the factorization, 2 the time for factorization, and 3 the required amount of main memory. We evaluate a total of 30 setups with a varying number of references on data from three different species. Our results show a wide range of factorization sizes (optimal to an overhead of up to 300%, factorization speed (0.01 MB/s to more than 600 MB/s, and main memory usage (few dozen MB to dozens of GB. Based on our evaluation, we identify the best configurations for common use cases. Our evaluation shows that multi-reference factorization is much better than single-reference factorization.

  4. Uptake, accumulation and some biochemical responses in ...

    African Journals Online (AJOL)

    Under the conditions of these increasing zinc concentrations, the highest zinc accumulation was obtained in the roots of the plants treated with 10 mM applications. The zinc concentration in the vegetative parts, was highest in the root and was lowest in the cotyledons. The highest bioconcentration factor (BCF) value was ...

  5. Matrix Factorization for Evolution Data

    Directory of Open Access Journals (Sweden)

    Xiao-Yu Huang

    2014-01-01

    Full Text Available We study a matrix factorization problem, that is, to find two factor matrices U and V such that R≈UT×V, where R is a matrix composed of the values of the objects O1,O2,…,On at consecutive time points T1,T2,…,Tt. We first present MAFED, a constrained optimization model for this problem, which straightforwardly performs factorization on R. Then based on the interplay of the data in U, V, and R, a probabilistic graphical model using the same optimization objects is constructed, in which structural dependencies of the data in these matrices are revealed. Finally, we present a fitting algorithm to solve the proposed MAFED model, which produces the desired factorization. Empirical studies on real-world datasets demonstrate that our approach outperforms the state-of-the-art comparison algorithms.

  6. Crash Data Safety Factors Evaluation

    Science.gov (United States)

    2017-11-30

    The purpose of this project was to identify annual trends and contributory factors of crashes involving mature drivers, vulnerable road users, fatal and injury crashes involving guiderail, and collisions resulting from vehicle failures. Three years o...

  7. Disadvantage factor for anisotropic scattering

    International Nuclear Information System (INIS)

    Saad, E.A.; Abdel Krim, M.S.; EL-Dimerdash, A.A.

    1990-01-01

    The invariant embedding method is used to solve the problem for a two region reactor with anisotropic scattering and to compute the disadvantage factor necessary for calculating some reactor parameters

  8. Factorization properties of finite spaces

    Energy Technology Data Exchange (ETDEWEB)

    Simkhovich, B; Mann, A; Zak, J, E-mail: boriskas@tx.technion.ac.i, E-mail: ady@physics.technion.ac.i, E-mail: zak@physics.technion.ac.i [Department of Physics, Technion-Israel Institute of Technology, Haifa 32000 (Israel)

    2010-01-29

    In 1960 Schwinger (J Schwinger 1960 Proc. Natl Acad. Sci. 46 570-9) proposed the algorithm for factorization of unitary operators in the finite M-dimensional Hilbert space according to a coprime decomposition of M. Using a special permutation operator A we generalize the Schwinger factorization to every decomposition of M. We obtain the factorized pairs of unitary operators and show that they obey the same commutation relations as Schwinger's. We apply the new factorization to two problems. First, we show how to generate two kq-like mutually unbiased bases for any composite dimension. Then, using a Harper-like Hamiltonian model in the finite dimension M = M{sub 1}M{sub 2}, we show how to design a physical system with M{sub 1} energy levels, each having degeneracy M{sub 2}.

  9. Lithuanian Population Aging Factors Analysis

    Directory of Open Access Journals (Sweden)

    Agnė Garlauskaitė

    2015-05-01

    Full Text Available The aim of this article is to identify the factors that determine aging of Lithuania’s population and to assess the influence of these factors. The article shows Lithuanian population aging factors analysis, which consists of two main parts: the first describes the aging of the population and its characteristics in theoretical terms. Second part is dedicated to the assessment of trends that influence the aging population and demographic factors and also to analyse the determinants of the aging of the population of Lithuania. After analysis it is concluded in the article that the decline in the birth rate and increase in the number of emigrants compared to immigrants have the greatest impact on aging of the population, so in order to show the aging of the population, a lot of attention should be paid to management of these demographic processes.

  10. Nutritional factors in gallbladder diseases

    Directory of Open Access Journals (Sweden)

    Thaiane Prolo

    2018-01-01

    Full Text Available Biliary system disorders are all diseases that affect the gallbladder and the ducts. They may be originated from various etiologies. Inadequate living habits, being female and smoking are risk factors for the development of these diseases, as well as poor nutrition, nutritional deficiencies, obesity and metabolic syndrome. However, the adequate consumption of fruits and vegetables and the regular practice of physical activity act as protective factors for these diseases.

  11. Environmental risk factors and pressures

    International Nuclear Information System (INIS)

    Klinda, J.; Lieskovska, Z.

    1998-01-01

    In this chapter the physical risk factors (as radiation [air contamination, contamination of the environment components and food contamination], radon and its radioactive decay products, radioactive wastes, noise), chemical risk factors [chemical substances, xenobiotics in the food chain the ozone depletion], wastes (waste generation, waste management, municipal waste management, import, export and transit of waste) and natural an technological hazards (water quality deterioration as a result of various accidents and fire risk) in the Slovak Republic in 1997 are reviewed

  12. Factors Influencing Healthcare Service Quality

    OpenAIRE

    Ali Mohammad Mosadeghrad

    2014-01-01

    Background The main purpose of this study was to identify factors that influence healthcare quality in the Iranian context. Methods Exploratory in-depth individual and focus group interviews were conducted with 222 healthcare stakeholders including healthcare providers, managers, policy-makers, and payers to identify factors affecting the quality of healthcare services provided in Iranian healthcare organisations. Results Quality in healthcare is a production o...

  13. Growth factors and new periodontology

    Directory of Open Access Journals (Sweden)

    Paknejad M

    1999-06-01

    Full Text Available Growth factors are biological mediators that have a key roll in proliferation, chemotaxy and"ndifferentiation by acting on specific receptors on the surface of cells and regulating events in wound"nhealing.They can be considered hormones that are not released in to the blood stream but have one a"nlocal action. Some of these factors can regulate premature change in GO to Gl phase in cell devesion"ncycle and even may stimulate synthesis of DNA in suitable cells, Growth substances, primarily secreted"nby fibroblasts, endothelia! cells, macrophages and platelet, include platelet derived growth factor"n(PDGF, insulin like growth factor (IGF transforming growth factor (TGFa and (3 and bone"nmorphogenetic proteins BMPs that approximately are the most important of them. (BMPs could be"nused to control events during periodontal, craniofacial and implant wound healing through favoring bone"nformation"nAccording toLynch, combination of PGDF and IGF1 would be effective in promoting growth of all the"ncomponents of the periodontium."nThe aim of this study was to characterize growth factor and review the literature to determine the"nmechanism of their function, classification and application in implant and periodontal treatment.

  14. Multi-factor authentication using quantum communication

    Science.gov (United States)

    Hughes, Richard John; Peterson, Charles Glen; Thrasher, James T.; Nordholt, Jane E.; Yard, Jon T.; Newell, Raymond Thorson; Somma, Rolando D.

    2018-02-06

    Multi-factor authentication using quantum communication ("QC") includes stages for enrollment and identification. For example, a user enrolls for multi-factor authentication that uses QC with a trusted authority. The trusted authority transmits device factor information associated with a user device (such as a hash function) and user factor information associated with the user (such as an encrypted version of a user password). The user device receives and stores the device factor information and user factor information. For multi-factor authentication that uses QC, the user device retrieves its stored device factor information and user factor information, then transmits the user factor information to the trusted authority, which also retrieves its stored device factor information. The user device and trusted authority use the device factor information and user factor information (more specifically, information such as a user password that is the basis of the user factor information) in multi-factor authentication that uses QC.

  15. Factors Influencing Heart Rate Variability

    Directory of Open Access Journals (Sweden)

    Stefan Sammito

    2016-01-01

    Full Text Available The measurement and analysis of heart rate variability (HRV, which is based on the variation between consecutive NN intervals, has become an established procedure over the past two decades. A decrease in HRV has been shown to correlate with an increase in mortality. HRV is influenced by a number of physiological factors such as various diseases. Awareness of these mediators or confounders is of great importance in the analysis and assessment of HRV both in scientific studies and in clinical practice. This document, which is based on a selective survey of references and supplemented by information from national and international guidelines, presents the main endogenous, exogenous and constitutional factors. A decrease in HRV has been observed not only in connection with non-influenceable physiological factors such as age, gender and ethnic origin, but also in conjunction with a large number of acute and chronic diseases. Numerous lifestyle factors have both a positive and a negative influence on HRV. There are also physical influences that affect HRV. They must on no account be disregarded. Although the list of the factors is long and not all of them have yet been fully studied, awareness of them is of crucial importance in the measurement of HRV (both under laboratory conditions and during medical practice, its analysis and its assessment. More research also needs to be carried out to close knowledge gaps.

  16. Factors Influencing Healthcare Service Quality

    Directory of Open Access Journals (Sweden)

    Ali Mohammad Mosadeghrad

    2014-07-01

    Full Text Available Background The main purpose of this study was to identify factors that influence healthcare quality in the Iranian context. Methods Exploratory in-depth individual and focus group interviews were conducted with 222 healthcare stakeholders including healthcare providers, managers, policy-makers, and payers to identify factors affecting the quality of healthcare services provided in Iranian healthcare organisations. Results Quality in healthcare is a production of cooperation between the patient and the healthcare provider in a supportive environment. Personal factors of the provider and the patient, and factors pertaining to the healthcare organisation, healthcare system, and the broader environment affect healthcare service quality. Healthcare quality can be improved by supportive visionary leadership, proper planning, education and training, availability of resources, effective management of resources, employees and processes, and collaboration and cooperation among providers. Conclusion This article contributes to healthcare theory and practice by developing a conceptual framework that provides policy-makers and managers a practical understanding of factors that affect healthcare service quality.

  17. Study of angiogenic factors: Vascular endothelia growth factor ...

    African Journals Online (AJOL)

    The pre-therapeutic serum levels of the angiogenic factors VEGF and bFGF were detected in the sera of HCC patients to find new markers to be used for diagnosis of HCC, and were compared with the routinely used tumor markers used for diagnosis of HCC as AFP, CEA, and CA19.9. The relation between the serum levels ...

  18. Which shape factor(s) best describe granules?

    NARCIS (Netherlands)

    Bouwman, Anneke M.; Bosma, Jaap C.; Vonk, Pieter; Wesselingh, J.A.; Frijlink, Henderik W.

    2004-01-01

    This study evaluates methods used for granule shape characterization. The aim is to identify an optimal combination of shape factors to measure granule shape and roughness. Granules were prepared from microcrystalline cellulose (MCC), alpha-lactose, microfine cellulose (MFC), and dextrin, using a

  19. General Factors of the Korean Exposure Factors Handbook

    Science.gov (United States)

    Kim, So-Yeon; Kim, Sun-Ja; Lee, Kyung-Eun; Cheong, Hae-Kwan; Kim, Eun-Hye; Choi, Kyung-Ho; Kim, Young-Hee

    2014-01-01

    Risk assessment considers the situations and characteristics of the exposure environment and host. Various physiological variables of the human body reflects the characteristics of the population that can directly influence risk exposure. Therefore, identification of exposure factors based on the Korean population is required for appropriate risk assessment. It is expected that a handbook about general exposure factors will be used by professionals in many fields as well as the risk assessors of the health department. The process of developing the exposure factors handbook for the Korean population will be introduced in this article, with a specific focus on the general exposure factors including life expectancy, body weight, surface area, inhalation rates, amount of water intake, and soil ingestion targeting the Korean population. The researchers used national databases including the Life Table and the 2005 Time Use Survey from the National Statistical Office. The anthropometric study of size in Korea used the resources provided by the Korean Agency for Technology and Standards. In addition, direct measurement and questionnaire surveys of representative samples were performed to calculate the inhalation rate, drinking water intake, and soil ingestion. PMID:24570802

  20. Factors Driving Business Intelligence Culture

    Directory of Open Access Journals (Sweden)

    Rimvydas Skyrius

    2016-05-01

    Full Text Available The field of business intelligence (BI, despite rapid technology advances, continues to feature inadequate levels of adoption. The attention of researchers is shifting towards hu-man factors of BI adoption. The wide set of human factors influencing BI adoption con-tains elements of what we call BI culture – an overarching concept covering key managerial issues that come up in BI implementation. Research sources provide different sets of features pertaining to BI culture or related concepts – decision-making culture, analytical culture and others. The goal of this paper is to perform the review of research and practical sources to examine driving forces of BI – data-driven approaches, BI agility, maturity and acceptance – to point out culture-related issues that support BI adoption and to suggest an emerging set of factors influencing BI culture.

  1. Critical factors for EIA implementation

    DEFF Research Database (Denmark)

    Zhang, Jasmine; Kørnøv, Lone; Christensen, Per

    2013-01-01

    After decades of development, the gap between expectations of Environment Impact Assessments (EIA) and their practical performance remains significant. Research has been done to identify the critical factors for an effective implementation of EIA. However, this research, to a large extent, has...... not been cumulated and analysed comprehensively according to the stages of the EIA process. This paper contributes to the critical review of the literature on EIA implementation and effectiveness by cumulating mainly empirical findings in an implementation theoretical perspective. It focuses on the links...... between different critical factors and how they relate to different stages in the EIA and thus influence the decision making process. After reviewing 33 refereed journal articles published between 1999 and 2011, we identified 203 notions of critical factors. Of these, 102 related to different stages...

  2. Success factors in technology development

    Science.gov (United States)

    Preston, John T.

    1995-01-01

    Universities in the U.S. have a significant impact on business through the transfer of technology. This paper describes goals and philosophy of the Technology Licensing Office at the Massachusetts Institute of Technology. This paper also relates the critical factors for susscessful technology transfer, particularly relating to new business formation. These critical factors include the quality of the technology, the quality of the management, the quality of the investor, the passion for success, and the image of the company. Descriptions of three different levels of investment are also given and the most successful level of investment for starting a new company is reviewed. Licensing to large companies is also briefly reviewed, as this type of licensing requires some different strategies than that of licensing to start-up companies. High quality critical factors and intelligent investment create rewards for the parties and successful ventures.

  3. Perinatal risk factors including malformation

    International Nuclear Information System (INIS)

    Brachner, A.; Grosche, B.

    1991-10-01

    The study gives a survey of the factors most frequently mentioned in the literature as factors likely to adversely affect a pregnancy. One essential aspect is the discussion of those factors that can be counted among the causes of malformations, as among others, prenatal radiation exposure. The study prepared within the framework of the research project 'Radiobiological environmental monitoring in Bavaria' is intended to serve as a basis for a retrospective and prospective evaluation of infant mortality, perinatal conditions and occurrence of malformations in Bavaria, with the principal idea of drawing up an environment - related health survey. The study therefore, in addition to ionizing radiation also takes into account other detectable risks within the ecologic context, as e.g. industrial installations, refuse incineration plants or waste dumps, or urbanity. (orig./MG) [de

  4. An unsymmetrized multifrontal LU factorization

    Energy Technology Data Exchange (ETDEWEB)

    Amestoy, Patrick R.; Puglisi, Chiara

    2000-07-17

    A well-known approach to compute the LU factorization of a general unsymmetric matrix bf A is to build the elimination tree associated with the pattern of the symmetric matrix A + A{sup T} and use it as a computational graph to drive the numerical factorization. This approach, although very efficient on a large range of unsymmetric matrices, does not capture the unsymmetric structure of the matrices. We introduce a new algorithm which detects and exploits the structural unsymmetry of the submatrices involved during the process of the elimination tree. We show that with the new algorithm significant gains both in memory and in time to perform the factorization can be obtained.

  5. The selection of occupancy factors

    International Nuclear Information System (INIS)

    Lakey, J.R.A.

    1977-01-01

    An estimate of the proportion of time that an area is occupied by radiation workers is often used in radiological protection to permit relaxation of exposure rate limits above those for continuous occupation. This proportion is known as an occupancy factor and is used most frequently in X-ray facilities. The strategy for controlling the external exposure of radiation workers must be decided before occupancy factors are selected for the design of the radiation protection facilities. When shielding has to be designed the occupancy factor effects the design objectives and permits increased exposure rates at the shield surface. It is useful to note that the selection of occupancy factors with due regard to the expected spatial variation of the exposure rate can help to reduce the range of the worker's radiation exposure because field gradients are usually steeper close to the shield. When other hazards, such as internal exposure, and other constraints, such as cost of the space consumed, are added, the selection of the optimum set of occupancy factors is more difficult. Two zone occupancy factors are discussed in this paper and proposals are made for a strategy to be used when there is more than one hazard and the designer has to meet constraints imposed by limitations of the facilities available. An important feature of the strategy is the avoidance of high radiation exposure to small groups of workers. The errors involved in assessment of the actual dose received by the radiation worker must be taken into account and in particular the selection of the higher exposure rate limits must be made with attention to the accident potential

  6. Theoretical difference between impact factor and influence factor

    Directory of Open Access Journals (Sweden)

    Đilda Pečarić

    2010-06-01

    Full Text Available Bibliometric constructions of "knowledge maps" and "cognitive structures of science" do not differentiate between impact and influence factors. The difference can be constructedaccording to different meaning and interpretation of the terms reference and citation. Reference is "acknowledgment which one author gives to another", whereas citation is "acknowledgment which one document receives from another". Development of Information Science according to period and subject area is analyzed on the corpus of citation literature retrieved from doctoral dissertations in Information Science from 1978 to 2007 at Croatian universities. The research aim is to indicate the difference between document impact factor and author's influence factor (i.e. reference ability to produce effects on actions, behavior, and opinions of authors of doctoral theses. The influence factor serves to distinguish the key role of cited authors in time and according to the duration of the influence (the average age for cited papers of dominant authors in different periods is between eight and ten years. The difference between linear and interactive communication seems vital for the interpretation of cited half-life, i.e. the attitude of one science community towards used information resources and cognitive heritage. The analyzed corpus of 22,210 citations can be divided into three communication phases according to influence factor criteria: in the phase of dialogue and interactive communication 25% of bibliographic units are cited in the first four years; in the second phase another 25% of units are cited from the fifth to the ninth year; after ten years, in the dominant linear communication phase, approximately 30% of units are cited.

  7. Effectiveness of human factors simulator

    International Nuclear Information System (INIS)

    Moragas, F.

    2015-01-01

    En 2011, ANAV started the exploitation of the Human Factors Simulator installed in TECNATOM Training Center located in L'Hospital de L'Infant Tarragona. AVAN's Strategic Plan includes the Action Plan for the improvement of human behavior. The plan includes improving the efficiency of the efficiency of the human factors simulator. It is proposed to improve the efficiency into two different terms: winning effectiveness in modeling behaviors, and interweaving the activities in the simulator with the actual strategy of promoting Safety culture and human behaviour. (Author)

  8. The gamma contamination food factor

    International Nuclear Information System (INIS)

    Kukoc, A.H.; Anicin, I.V.; Adzic, P.R.

    1992-01-01

    We suggest that radioactive food contamination, as determined solely by a quantitative gamma-ray spectroscopic measurement, may, apart from the total activity per unit mass, be for quick reference conveniently characterized by another single figure which we call the ''Gamma Contamination Food Factor'' (GCFF). This factor may be defined as the ratio of the total specific activity of gamma-ray-emitting radionuclides in the food sample (except that of 40 K) to the specific activity of 40 K either in the sample itself or in an ''average man''. We discuss briefly the meaning and advantages of these definitions. (author)

  9. Determining Factors of Subsidiary Development

    DEFF Research Database (Denmark)

    Pedersen, Torben

    (the depth of activities) and level of integration in the internal MNC-network. Birkinshaw and Hood (1998a) have in their seminal paper proposed a model where subsidiary development is determined by three factors: Headquarter assignment, dynamism of local business environment and subsidiary initiatives....... This paper is the first to conduct a statistical test of this model on a large-sample data set including data of more than 2.100 subsidiaries located in seven different countries in Europe. The effect of the three determining factors on subsidiary development is tested simultaneously in a LISREL model....

  10. Factores de crecimiento III: factores transformadores del crecimiento (TGF Growth factors III part: transforming growth factors (TGF

    Directory of Open Access Journals (Sweden)

    Hilda Norha Jaramillo Londoño

    1996-04-01

    Full Text Available Se presenta una revisión de los conceptos básicos sobre los factores transformadores del crecimiento, tanto alfa como beta, incluyendo los siguientes aspectos: consideraciones generales, estructura bioquímica, concentraciones, proteínas transportadoras, receptores, mecanismos de acción y efectos biológicos. A review is presented on the basic concepts of Transforming Growth Factors both a and p; it includes general considerations, biochemical structure, concentrations, binding proteins, receptors, mechanisms of action, and biological effects.

  11. Efficiency factors in Mie scattering

    International Nuclear Information System (INIS)

    Nussenzveig, H.M.

    1980-04-01

    Asymptotic approximation to the Mie efficiency factors for extinction, absorption and radiation pressure, derived from complex angular momentum theory and averaged over Δβ approximately π (β = size parameter), are given and compared with the exact results. For complex refractive indices N = n + i kappa with 1.1 -2 - 10 -3 % between β = 10 and β = 1000, and computing time is reduced by a factor of order β, so that the Mie formulae can advantageously by replaced by the asymptotic ones in most applications. (Author) [pt

  12. Factores de riesgo de la enfermedad periodontal: factores genéticos Risks factors in periodontal diseases: genetic factors

    OpenAIRE

    M. Rioboo Crespo; A. Bascones

    2005-01-01

    Hoy en día y tras numerosos estudios epidemiológicos, se acepta el concepto de la existencia de determinados factores de riesgo que van a modular la susceptibilidad o resistencia del hospedador a padecer enfermedad periodontal, por lo tanto, en el desarrollo van a intervenir varias causas considerándose dicha patología de etiología multifactorial. De este modo, las enfermedades periodontales son producidas por una interacción de un agente microbiano único o múltiple considerado como el factor...

  13. General introduction and recovery factors

    Science.gov (United States)

    Verma, Mahendra K.

    2017-07-17

    IntroductionThe U.S. Geological Survey (USGS) compared methods for estimating an incremental recovery factor (RF) for the carbon dioxide enhanced oil recovery (CO2-EOR) process involving the injection of CO2 into oil reservoirs. This chapter first provides some basic information on the RF, including its dependence on various reservoir and operational parameters, and then discusses the three development phases of oil recovery—primary, second­ary, and tertiary (EOR). It ends with a brief discussion of the three approaches for estimating recovery factors, which are detailed in subsequent chapters.

  14. Prognostic Factors in Hodgkin's Disease

    DEFF Research Database (Denmark)

    Specht

    1996-01-01

    regions and the tumor mass in each region are important, and an estimate of the total tumor burden has proved significant. B symptoms, histological subtype, age, and gender are also generally significant but less important. Prognostic factors for laparotomy findings in clinical stages I and II are: number...... of involved regions, disease confined to upper cervical nodes, B symptoms, gender, histology, age, and mediastinal disease (variable influence). In clinical stages I and II, the same prognostic factors apply as for pathological stages I and II and for laparotomy findings, and also some indirect indicators...

  15. Absorption factor for cylindrical samples

    International Nuclear Information System (INIS)

    Sears, V.F.

    1984-01-01

    The absorption factor for the scattering of X-rays or neutrons in cylindrical samples is calculated by numerical integration for the case in which the absorption coefficients of the incident and scattered beams are not equal. An extensive table of values having an absolute accuracy of 10 -4 is given in a companion report [Sears (1983). Atomic Energy of Canada Limited, Report No. AECL-8176]. In the present paper an asymptotic expression is derived for the absorption factor which can be used with an error of less than 10 -3 for most cases of interest in both neutron inelastic scattering and neutron diffraction in crystals. (Auth.)

  16. Risk factors and diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Vahid Jusufović

    2012-02-01

    Full Text Available The aim of the study was to determine the correlation between risk factors and diabetic retinopathy, which is the leading cause of blindness in developed countries for patients aged 20 to 65.We compared risk factors between patients without retinopathy, with non-proliferate and with proliferate retinopathy (p< 0.05. Duration of diabetes is most important for the development of retinopathy. Hyperglycaemia and high blood pressure are important for progression. Better control of blood sugar and elevated blood pressure can reduce progression of retinopathy and riskof vision loss.

  17. Social networks and factor markets

    DEFF Research Database (Denmark)

    Abay, Kibrom Araya; Kahsay, Goytom Abraha; Berhane, Guush

    2018-01-01

    We investigate the role of an indigenous social network in Ethiopia, the iddir, in facilitating factor market transactions among smallholder farmers. We use a detailed longitudinal household survey data and employ a fixed effects estimation to identify the effect of iddir membership on factor...... market transactions among farmers. We find that joining an iddir network improves households’ access to land, labour and credit transactions. Our findings also hint that iddir networks may crowd-out borrowing from local moneylenders (locally referred as ‘Arata Abedari’), a relatively expensive credit...... source. These results suggest that non-market institutions can play crucial roles in facilitating market transactions....

  18. Factores de risco em implantologia

    OpenAIRE

    Sousa, Inês Silveira e Luz Nunes de

    2015-01-01

    A Implantologia tem ganho popularidade na medicina dentária pelos resultados previsíveis em reabilitações de áreas edêntulas, permitindo minimizar as consequências funcionais, fonéticas e estéticas que advém da perda de dentes através de uma solução fixa que satizfaz os pacientes. Esta é uma revisão da literatura existente sobre factores de risco, fracassos e complicações inerentes ao tratamento com implantes dentários. Categorizam-se os factores de risco em implantologia co...

  19. $K_{13}$ transition form factors

    CERN Document Server

    Chueng Ryong Ji

    2001-01-01

    The rainbow truncation of the quark Dyson-Schwinger equation is combined with the ladder Bethe-Salpeter equation for the meson bound state amplitudes and the dressed quark-W vertex in a manifestly covariant calculation of the K/sub l3/ transition form factors and decay width in the impulse approximation. With model gluon parameters previously fixed by the chiral condensate, the pion mass and decay constant, and the kaon mass, our results for the K/sub l3/ form factors and the kaon semileptonic decay width are in good agreement with the experimental data. (37 refs).

  20. Age factors in biometric processing

    CERN Document Server

    Fairhurst, Michael

    2013-01-01

    As biometrics-based identification and identity authentication become increasingly widespread in their deployment, it becomes correspondingly important to consider more carefully issues relating to reliability, usability and inclusion. One factor which is particularly important in this context is that of the relationship between the nature of the measurements extracted from a particular biometric modality and the age of the sample donor, and the effect which age has on physiological and behavioural characteristics invoked in a biometric transaction. In Age Factors in Biometric Processing an in

  1. Tissue factor-dependent activation of tritium-labeled factor IX and factor X in human plasma

    International Nuclear Information System (INIS)

    Morrison, S.A.; Jesty, J.

    1984-01-01

    A comparism was made of the tissue factor-dependent activation of tritium-labeled factor IX and factor X in a human plasma system and a study was made of the role of proteases known to stimulate factor VII activity. Plasma was defibrinated by heating and depleted of its factors IX and X by passing it through antibody columns. Addition of human brain thromboplastin, Ca2+, and purified 3H-labeled factor X to the plasma resulted, after a short lag, in burst-like activation of the factor X, measured as the release of radiolabeled activation peptide. The progress of activation was slowed by both heparin and a specific inhibitor of factor Xa but factor X activation could not be completely abolished by such inhibitors. In the case of 3H-factor IX activation, the rate also increased for approximately 3 min after addition of thromboplastin, but was not subsequently curtailed. A survey of proteases implicated as activators of factor VII in other settings showed that both factor Xa and factor IXa could accelerate the activation of factor IX. However, factor Xa was unique in obliterating activation when present at concentrations greater than approximately 1 nM. Heparin inhibited the tissue factor-dependent activation of factor IX almost completely, apparently through the effect of antithrombin on the feedback reactions of factors Xa and IXa on factor VII. These results suggest that a very tight, biphasic control of factor VII activity exists in human plasma, which is modulated mainly by factor Xa. At saturation of factor VIIa/tissue factor, factor IX activation was significantly more rapid than was previously found in bovine plasma under similar conditions. The activation of factor X at saturation was slightly more rapid than in bovine plasma, despite the presence of heparin

  2. Factors in Dubbing Television Comedy.

    Science.gov (United States)

    Zabalbeascoa, Patrick

    1994-01-01

    Advocates a greater awareness of the factors involved with dubbing television comedies. Considers the translation of jokes and provides an outline of the various kinds of jokes in television shows. Calls for more research on comedy dubbing and television translation in general. (HB)

  3. Five Describing Factors of Dyslexia

    Science.gov (United States)

    Tamboer, Peter; Vorst, Harrie C. M.; Oort, Frans J.

    2016-01-01

    Two subtypes of dyslexia (phonological, visual) have been under debate in various studies. However, the number of symptoms of dyslexia described in the literature exceeds the number of subtypes, and underlying relations remain unclear. We investigated underlying cognitive features of dyslexia with exploratory and confirmatory factor analyses. A…

  4. [Virulence factors of Candida albicans].

    Science.gov (United States)

    Staniszewska, Monika; Bondaryk, Małgorzata; Piłat, Joanna; Siennicka, Katarzyna; Magda, Urszula; Kurzatkowski, Wiesław

    2012-01-01

    Candida albicans is the most common etiological factor of opportunistic human fungal infections. In this review, we focus on the major virulence factors that mediate the pathogenesis of C. albicans. Among these virulence factors, secreted aspartyl proteases, adherence, pleomorphism are the most important features of C. albicans infections. Ability to exist as different pleomorphic forms is defined as pleomorphism. A number of quorum sensing (QS) molecules have been described which affect morphogenesis process in C. albicans. Furthermore, the morphological transition of C. albicans in response to changing environmental conditions represent a means by which the strain adapts to different biological niches. Furthermore, every morphotype has own virulence profile and each pleomorphic form provide critical functions required for pathogenesis. Candida albicans is a producer of extracellular hydrolytic enzymes. Among them lipases, phospholipases and secreted aspartyl proteinases (Sap) are most significant in virulence. Sap proteins contribute to pathogenesis by digestion of host cell membranes and molecules of the host immune system to avoid antimicrobial attack by the host. One of the key features in the development of candidiasis is adhesion ofC. albicans to buccal and vaginal epithelial cells. The adhesion to host cells represents the first step in the internalization process which involves adhesins. Knowledge of the role of the various C. albicans' virulence factors during in vivo infections is still incomplete, therefore further studies including quantification of genes expression and histopathological examination of tissues damage are required to fully understand pathogenesis of this opportunistic pathogen.

  5. Cardiovascular risk factors in men

    DEFF Research Database (Denmark)

    Gyllenborg, J; Rasmussen, S L; Borch-Johnsen, Knut

    2001-01-01

    Males have higher risk of cardiovascular disease (CVD) than premenopausal females. Gonadal steroids are probably involved in the gender difference in CVD, but previous results have been conflicting. We investigated the associations between CVD risk factors and sex hormones in a cross...

  6. Psychological Risk Factors in Headache

    Science.gov (United States)

    Nicholson, Robert A.; Houle, Timothy T.; Rhudy, Jamie L.; Norton, Peter J.

    2008-01-01

    Headache is a chronic disease that occurs with varying frequency and results in varying levels of disability. To date, the majority of research and clinical focus has been on the role of biological factors in headache and headache-related disability. However, reliance on a purely biomedical model of headache does not account for all aspects of headache and associated disability. Using a biopsychosocial framework, the current manuscript expands the view of what factors influence headache by considering the role psychological (i.e., cognitive and affective) factors have in the development, course, and consequences of headache. The manuscript initially reviews evidence showing that neural circuits responsible for cognitive–affective phenomena are highly interconnected with the circuitry responsible for headache pain. The manuscript then reviews the influence cognitions (locus of control and self-efficacy) and negative affect (depression, anxiety, and anger) have on the development of headache attacks, perception of headache pain, adherence to prescribed treatment, headache treatment outcome, and headache-related disability. The manuscript concludes with a discussion of the clinical implications of considering psychological factors when treating headache. PMID:17371358

  7. NAC transcription factors in senescence

    DEFF Research Database (Denmark)

    Podzimska-Sroka, Dagmara; O'Shea, Charlotte; Gregersen, Per L.

    2015-01-01

    Within the last decade, NAC transcription factors have been shown to play essential roles in senescence, which is the focus of this review. Transcriptome analyses associate approximately one third of Arabidopsis NAC genes and many crop NAC genes with senescence, thereby implicating NAC genes as i...

  8. Introduction to human factors engineering

    International Nuclear Information System (INIS)

    Derfuss, Ch.

    2010-01-01

    Some of the main aspects of human factors engineering are discussed. The following topics are considered: Integration into the design process; Identification and application of human-centered design requirements; Design of error-tolerant systems; Iterative process consisting of evaluations and feedback loops; Participation of operators/users; Utilization of an interdisciplinary design/ evaluation team; Documentation of the complete HFE-process: traceability

  9. Factors in Infectious Disease Emergence

    Indian Academy of Sciences (India)

    Factors: Societal events: Population growth and migration (movement from rural areas to cities); war or civil conflict; urban decay; sexual behavior; intravenous drug use; use of high-density facilities. Disease examples: Introduction of HIV; spread of dengue; spread of HIV and other sexually transmitted diseases.

  10. Transcription factor-based biosensor

    Science.gov (United States)

    Dietrich, Jeffrey A; Keasling, Jay D

    2013-10-08

    The present invention provides for a system comprising a BmoR transcription factor, a .sigma..sup.54-RNA polymerase, and a pBMO promoter operatively linked to a reporter gene, wherein the pBMO promoter is capable of expression of the reporter gene with an activated form of the BmoR and the .sigma..sup.54-RNA polymerase.

  11. The factorization method and supersymmetry

    International Nuclear Information System (INIS)

    Alves, N.A.; Drigo Filho, E.

    1988-01-01

    Applying the factorization method, we generalize the harmonic - oscillator and the Coulomb potentials, both in arbitrary dimensions. We also show that this method allows the determination of the superpotentials and the supersymmetric partners associated with each of those systems. (author) [pt

  12. Factors driving aquaculture technology adoption

    Science.gov (United States)

    Technology adoption has played a key role in the global development and increase in agricultural productivity. However, the decision to adopt a new technology on farms is complex. While the factors that drive the adoption of new technologies have been well studied in agriculture, less attention has ...

  13. Logistical Factors in Teachers' Motivation

    Science.gov (United States)

    Daniels, Erika

    2016-01-01

    Research in education and psychology contributes to an understanding of how educators create contexts for learning that encourage intrinsic motivation and increase academic achievement. In this article, the researcher investigated how teachers themselves define effectiveness and identified what factors influence their motivation, both positively…

  14. Cognitive Factors in Academic Achievement.

    Science.gov (United States)

    Cuasay, Peter

    1992-01-01

    This review explores the factors of cognitive processing, style, and metacognitive organization as they contribute to academic success. Specific discussions consider aspects of short- and long-term memory, including how these affect learning and academic performance, and the keys to attaining long-term memory capability by involving redundancy,…

  15. Detecting Risk Factor of Diseases

    Czech Academy of Sciences Publication Activity Database

    Zvárová, Jana

    1995-01-01

    Roč. 15, 1/2 (1995), s. 203-212 ISSN 0208-5216. [Seminar on Statistics and Clinical Practice. Warsaw, 20.06.1994-23.06.1994] Keywords : risk factors * genetics * association * epidemilogy * measures of association * screening * genetics

  16. HDG1 transcription factor targets

    NARCIS (Netherlands)

    Horstman, A.; Boutilier, K.A.; Sanchez Perez, Gabino

    2015-01-01

    The AIL transcription factor BABY BOOM (BBM) is required together with the related PLETHORA proteins for embryo and root meristem development and its expression is sufficient to confer pluripotency and totipotency to somatic tissues. We show that BBM and other AIL proteins interact with multiple

  17. Factors influencing bone scan quality

    International Nuclear Information System (INIS)

    Adams, F.G.; Shirley, A.W.

    1983-01-01

    A reliable subjective method of assessing bone scan quality is described. A large number of variables which theoretically could influence scan quality were submitted to regression and factor analysis. Obesity, age, sex and abnormality of scan were found to be significant but weak variables. (orig.)

  18. Landscape genetics and limiting factors

    Science.gov (United States)

    Samuel A. Cushman; Andrew J. Shirk; Erin L. Landguth

    2013-01-01

    Population connectivity is mediated by the movement of organisms or propagules through landscapes. However, little is known about how variation in the pattern of landscape mosaics affects the detectability of landscape genetic relationships. The goal of this paper is to explore the impacts of limiting factors on landscape genetic processes using simulation...

  19. Bioactive factors in human milk.

    Science.gov (United States)

    Hamosh, M

    2001-02-01

    This article reviews the bioactive components of human milk. Special emphasis is given to immune and nonimmune protective function of major and minor nutrients in human milk. Immune modulating components, such as cytokines, nucleotides, hormones, and growth factors, are discussed. Milk enzymes with digestive function in the newborn are reviewed.

  20. Field factors for asymmetric collimators

    International Nuclear Information System (INIS)

    Turner, J.R.; Butler, A.P.H.

    1996-01-01

    In recent years manufacturers have been supplying linear accelerators with either a single pair or a dual pair of collimators. The use of a model to relate off-axis field factors to on-axis field factors obviates the need for repeat measurements whenever the asymmetric collimators are employed. We have investigated the variation of collimator scatter Sc, with distance of the central ray x from the central axis for a variety of non square field sizes. Collimator scatter was measured by in-air measurements with a build-up cap. The Primaty-Off-Centre-Ratio (POCR) was measured in-air by scanning orthogonally across the beam with an ionization chamber. The result of the investigation is the useful prediction of off-axis field factors for a range of rectangular asymmetric fields using the simple product of the on-axis field factor and the POCR in air. The effect of asymmetry on the quality of the beam and hence the percent depth dose will be discussed. (author)

  1. Shot-noise Fano factor

    Czech Academy of Sciences Publication Activity Database

    Rajdl, K.; Lánský, Petr

    2015-01-01

    Roč. 92, č. 5 (2015), č. článku 052135. ISSN 2470-0045 Institutional support: RVO:67985823 Keywords : response function s * limit-theorems * spike trains * variability Subject RIV: BD - Theory of Information Impact factor: 2.252, year: 2015

  2. An innovation resistance factor model

    Directory of Open Access Journals (Sweden)

    Siti Salwa Mohd Ishak

    2016-09-01

    Full Text Available The process and implementation strategy of information technology in construction is generally considered through the limiting prism of theoretical contexts generated from innovation diffusion and acceptance. This research argues that more attention should be given to understanding the positive effects of resistance. The study develops a theoretical framing for the Integrated Resistance Factor Model (IRFM. The framing uses a combination of diffusion of innovation theory, technology acceptance model and social network perspective. The model is tested to identify the most significant resistance factors using Partial Least Square (PLS technique. All constructs proposed in the model are found to be significant, valid and consistent with the theoretical framework. IRFM is shown to be an effective and appropriate model of user resistance factors. The most critical factors to influence technology resistance in the online project information management system (OPIMS context are: support from leaders and peers, complexity of the technology, compatibility with key work practices; and pre-trial of the technology before it is actually deployed. The study provides a new model for further research in technology innovation specific to the construction industry.

  3. Seasonality of cardiovascular risk factors

    DEFF Research Database (Denmark)

    Marti-Soler, Helena; Gubelmann, Cédric; Aeschbacher, Stefanie

    2014-01-01

    OBJECTIVE: To assess the seasonality of cardiovascular risk factors (CVRF) in a large set of population-based studies. METHODS: Cross-sectional data from 24 population-based studies from 15 countries, with a total sample size of 237 979 subjects. CVRFs included Body Mass Index (BMI) and waist...

  4. Transforming Rubrics Using Factor Analysis

    Science.gov (United States)

    Baryla, Ed; Shelley, Gary; Trainor, William

    2012-01-01

    Student learning and program effectiveness is often assessed using rubrics. While much time and effort may go into their creation, it is equally important to assess how effective and efficient the rubrics actually are in terms of measuring competencies over a number of criteria. This study demonstrates the use of common factor analysis to identify…

  5. Factors Influencing Donor Partnership Effectiveness

    International Development Research Centre (IDRC) Digital Library (Canada)

    (UN Global Compact Office, 2007); and “an alliance between organizations from two or more ... programs related to the environment, global health, and ..... partnering process and the factors of influence, drawing on an example of a flagship initiative with a bilateral donor for an environment-focused program. As in most joint ...

  6. Decomposition using Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus

    2002-01-01

    , normally we have an ordering of landmarks (variables) along the contour of the objects. For the case with observation ordering the maximum autocorrelation factor (MAF) transform was proposed for multivariate imagery in\\verb+~+\\$\\backslash\\$cite{switzer85}. This corresponds to a R-mode analyse of the data...

  7. Risk factors for undescended testis.

    NARCIS (Netherlands)

    Brouwers, M.M.; Bruijne, L.M. de; Gier, R.P.E. de; Zielhuis, G.A.; Feitz, W.F.J.; Roeleveld, N.

    2012-01-01

    OBJECTIVE: To contribute to the understanding of the etiology of undescended testis (UDT), by exploring a wide range of potential risk factors in a case-referent study. PATIENTS AND METHODS: Cases and referents were recruited at five hospitals and included 200 boys with surgically corrected UDT and

  8. Three phase power factor controller

    Science.gov (United States)

    Nola, F. J. (Inventor)

    1984-01-01

    A power control circuit for a three phase induction motor is described. Power factors for the three phases are summed to provide a control signal, and this control signal is particularly filtered and then employed to control the duty cycle of each phase of input power to the motor.

  9. Human factors in software development

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, B.

    1986-01-01

    This book presents an overview of ergonomics/human factors in software development, recent research, and classic papers. Articles are drawn from the following areas of psychological research on programming: cognitive ergonomics, cognitive psychology, and psycholinguistics. Topics examined include: theoretical models of how programmers solve technical problems, the characteristics of programming languages, specification formats in behavioral research and psychological aspects of fault diagnosis.

  10. HUMAN PROSTATE CANCER RISK FACTORS

    Science.gov (United States)

    Prostate cancer has the highest prevalence of any non-skin cancer in the human body, with similar likelihood of neoplastic foci found within the prostates of men around the world regardless of diet, occupation, lifestyle, or other factors. Essentially all men with circulating an...

  11. EAMJ Factors Aug.indd

    African Journals Online (AJOL)

    2009-08-01

    Aug 1, 2009 ... those who are LTFU We studied factors associated with LTFU in a cohort of HIV sero- negative and sera-positive mothers in .... proportions, many studies have been instituted to learn more about the epidemiology ... Drop out due to lack of interest versus moving to a new geographical area: From a social ...

  12. Extension Procedures for Confirmatory Factor Analysis

    Science.gov (United States)

    Nagy, Gabriel; Brunner, Martin; Lüdtke, Oliver; Greiff, Samuel

    2017-01-01

    We present factor extension procedures for confirmatory factor analysis that provide estimates of the relations of common and unique factors with external variables that do not undergo factor analysis. We present identification strategies that build upon restrictions of the pattern of correlations between unique factors and external variables. The…

  13. The risk factor of thyroid

    International Nuclear Information System (INIS)

    Kusama, Tomoko

    1979-01-01

    For the purposes of radiation protection, the noteworthy risk of thyroid is carcinogenesis. The risk factor which ICRP presented in the publication-26 is 5 x 10 - 6 rem - 1 . This numerical value is based upon the estimated likelihood of inducing fatal thyroid cancer. On the other hand, the risk factor presented by the BEIR report is 4 x 10 - 6 yr - 1 . This value was decided after consideration of the risks of both fatal and non-fatal cancer of thyroid. The following features distinguished thyroid cancer from malignancy of other tissue from medical point of view. 1) A large difference between incidence and mortality in case of thyroid cancer is recognized, because the thyroid cancer could be successfully treated by surgical or radiological treatment. 2) The high prevalence of clinically silent tumor in thyroid gland has been reported. The incidence of thyroid cancer, therefore, is very dependent on methods of medical inspection. The prevalence of radiation induced thyroid cancer is modified by various factors such as age, sex, latency, dose and dose rate. The latent period is very important factors such as ave, sex, latency, dose and dose rate. The latent period is a very important factor in the estimation of accumulated total risk of thyroid malignancy. What is included in the risk caused by thyroid irradiation must be investigated. The risk of non-fatal cancer should be considered in the same way as that of fatal cancer. The dose-equivalent limit of thyroid in non-uniform irradiation caused by radioactive iodine is decided by the limit for non-stochastic effects. Therefore the further consideration of non-stochastic effects of thyroid is necessary. (author)

  14. Eigenstates of coupling factor and loss factor of piezoelectric ceramics

    International Nuclear Information System (INIS)

    Smits, J.G.

    1978-01-01

    A short history of piezoelectricity is given and its occurence in nature described. The physical background of piezoelectric loss is discussed together with how material coefficients like susceptibilities can be used to describe the relation between canonical variables and to determine the dissipation of energy. The piezoelectric coupling factor, the applications of the eigencoupling state, elastic and piezoelectric digenstates are dealt with. The composition of the measurement system is described and experimental values of ceramics given. (C.F.)

  15. Activated human neutrophils release hepatocyte growth factor/scatter factor.

    LENUS (Irish Health Repository)

    McCourt, M

    2012-02-03

    BACKGROUND: Hepatocyte growth factor or scatter factor (HGF\\/SF) is a pleiotropic cytokine that has potent angiogenic properties. We have previously demonstrated that neutrophils (PMN) are directly angiogenic by releasing vascular endothelial growth factor (VEGF). We hypothesized that the acute inflammatory response can stimulate PMN to release HGF. AIMS: To examine the effects of inflammatory mediators on PMN HGF release and the effect of recombinant human HGF (rhHGF) on PMN adhesion receptor expression and PMN VEGF release. METHODS: In the first experiment, PMN were isolated from healthy volunteers and stimulated with tumour necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS), interleukin-8 (IL-8), and formyl methionyl-leucyl-phenylalanine (fMLP). Culture supernatants were assayed for HGF using ELISA. In the second experiment, PMN were lysed to measure total HGF release and HGF expression in the PMN was detected by Western immunoblotting. Finally, PMN were stimulated with rhHGF. PMN CD 11a, CD 11b, and CD 18 receptor expression and VEGF release was measured using flow cytometry and ELISA respectively. RESULTS: TNF-alpha, LPS and fMLP stimulation resulted in significantly increased release of PMN HGF (755+\\/-216, 484+\\/-221 and 565+\\/-278 pg\\/ml, respectively) compared to controls (118+\\/-42 pg\\/ml). IL-8 had no effect. Total HGF release following cell lysis and Western blot suggests that HGF is released from intracellular stores. Recombinant human HGF did not alter PMN adhesion receptor expression and had no effect on PMN VEGF release. CONCLUSIONS: This study demonstrates that pro-inflammatory mediators can stimulate HGF release from a PMN intracellular store and that activated PMN in addition to secreting VEGF have further angiogenic potential by releasing HGF.

  16. Food Ingestion Factors of the Korean Exposure Factors Handbook

    Directory of Open Access Journals (Sweden)

    Jae-Yeon Jang

    2014-01-01

    Full Text Available The purpose of this study was to establish food ingestion factors needed to assess exposure to contaminants through food ingestion. The study reclassified the raw data of the Korean National Health and Nutrition Examination Survey in 2001 into 12 subcategories including grain products, meat products, fish and shellfish, and vegetables for international comparability of exposure evaluation. The criteria for food intake calculation were unified according to the characteristics of food groups, and recommended values for food ingestion factors were calculated through moisture correction and recategorization of cooked, processed, and mixed foods for each group. The average intake rate for grain and grain products was 6.25 g/kg-d per capita and the men's intake rate was approximately 8% higher than that of the women. The average intake rate of meat and meat products was 1.62 g/kg-d per capita and the men's intake rate was 30% higher than that of the women, on average. The average intake rate of fish and shellfish was 1.53 g/kg-d per capita, and the age groups of 1 to 2 and 3 to 6 recorded higher capita intake rates than other age groups, 2.62 g/kg-d and 2.25 g/kg-d, respectively. The average intake rate of vegetables was 6.47 g/kg-d per capita, with the age group of 1 to 2 recording the highest per capita intake rate of 9.79 g/kg-d and that of 13 to 19 recording the lowest mean. The study also offers recommended values for food ingestion factors of other food groups by gender, age, and region. The food ingestion exposure factors will need future updates in consideration of ongoing changes in food consumption behavior.

  17. Food ingestion factors of the Korean exposure factors handbook.

    Science.gov (United States)

    Jang, Jae-Yeon; Jo, Soo-Nam; Kim, Sun-Ja; Myung, Hyung-Nam; Kim, Cho-Il

    2014-01-01

    The purpose of this study was to establish food ingestion factors needed to assess exposure to contaminants through food ingestion. The study reclassified the raw data of the Korean National Health and Nutrition Examination Survey in 2001 into 12 subcategories including grain products, meat products, fish and shellfish, and vegetables for international comparability of exposure evaluation. The criteria for food intake calculation were unified according to the characteristics of food groups, and recommended values for food ingestion factors were calculated through moisture correction and recategorization of cooked, processed, and mixed foods for each group. The average intake rate for grain and grain products was 6.25 g/kg-d per capita and the men's intake rate was approximately 8% higher than that of the women. The average intake rate of meat and meat products was 1.62 g/kg-d per capita and the men's intake rate was 30% higher than that of the women, on average. The average intake rate of fish and shellfish was 1.53 g/kg-d per capita, and the age groups of 1 to 2 and 3 to 6 recorded higher capita intake rates than other age groups, 2.62 g/kg-d and 2.25 g/kg-d, respectively. The average intake rate of vegetables was 6.47 g/kg-d per capita, with the age group of 1 to 2 recording the highest per capita intake rate of 9.79 g/kg-d and that of 13 to 19 recording the lowest mean. The study also offers recommended values for food ingestion factors of other food groups by gender, age, and region. The food ingestion exposure factors will need future updates in consideration of ongoing changes in food consumption behavior.

  18. Pion transition form factor in k{sub T} factorization

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hsiang-nan [Academica Sinica, Taipei, Taiwan (China). Inst. of Physics; Tsing-Hua Univ., Hsinchu, Taiwan (China). Dept. of Phyiscs; National Cheng-Kung Univ., Tainan, Taiwan (China). Dept. of Physics; National Cheng-Chi Univ, Taipei, Taiwan (China). Inst. of Applied Physics; Mishima, Satoshi [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2009-07-15

    It has been pointed out that the recent BaBar data on the {pi}{gamma}{sup *} {yields} {gamma} transition form factor F{sub {pi}}{sub {gamma}}(Q{sup 2}) at low (high) momentum transfer squared Q{sup 2} indicate an asymptotic (flat) pion distribution amplitude. These seemingly contradictory observations can be reconciled in the k{sub T} factorization theorem: the increase of the measured Q{sup 2}FF{sub {pi}}{sub {gamma}}(Q{sup 2}) for Q{sup 2} > 10 GeV{sup 2} is explained by convoluting a k{sub T} dependent hard kernel with a flat pion distribution amplitude, k{sub T} being a parton transverse momentum. The low Q{sup 2} data are accommodated by including the resummation of {alpha}{sub s} ln{sup 2}x, x being a parton momentum fraction, which provides a stronger suppression at the endpoints of x. The next-to-leading-order correction to the pion transition form factor is found to be less than 20% in the considered range of Q{sup 2}. (orig.)

  19. Growth factors: first part Factores de crecimiento I

    Directory of Open Access Journals (Sweden)

    Hilda Norha Jaramillo Londoño

    1996-02-01

    Full Text Available

    Los factores de crecimiento tienen como función activar o inhibir la transcripción génica; es así como la cascada enzimática que se inicia con la activación de los receptores de la membrana citoplasmática, ya sean de tipo segundo mensajero o catalíticos, tiene como efecto final la fosforilación de proteínas, las cuales pueden ser: 1 enzimas que intervienen en las vías metabólicas; 2 proteínas promotoras de la transcripción de genes o, por el contrario, represoras de los mismos (31,32; en algunos casos el efecto final consiste en la transcripción de protooncogenes (33 cuyos productos pueden ser otro factor de crecimiento o receptores para éstos (16; 3 algunos factores de crecimiento ejercen sus efectos sobre los eventos postranscripcionales y postraslacionales (23.

    Los Factores de Crecimiento, incluyendo las citoquinas, representan un número muy grande de polipéptidos, glucoproteínas y otras moléculas relacionadas. Todos ellos promueven la proliferación, la diferenciación y las funciones especializadas de casi cualquier tipo de célula. Juegan un papel importante mediando los modos paracrino, autocrino y endocrino de comunicación. En esta primera parte de una serie se definen y clasifican los factores de crecimiento; para la clasificación se proponen diversos sistemas basados en el período de desarrollo del individuo en que actúan, en el punto crítico del ciclo celular sobre el que ejercen su acción y en los efectos fisiológicos que producen; se discuten, además, someramente, la composición química, los mecanismos de acción y las funciones de estas sustancias.

  20. Genetics Home Reference: factor V Leiden thrombophilia

    Science.gov (United States)

    ... Twitter Home Health Conditions Factor V Leiden thrombophilia Factor V Leiden thrombophilia Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Factor V Leiden thrombophilia is an inherited disorder of blood clotting . ...

  1. Borderline Personality Disorder: Therapeutic Factors.

    Science.gov (United States)

    Stone, Michael H

    2016-01-01

    Proponents of the now half-dozen major psychotherapeutic approaches tend to claim the superiority of their different approaches-known widely by their acronyms: CBT for Cognitive Behavioral Therapy, DBT for Dialectic Behavioral Therapy, MBT for Mentalization-Based Therapy, TFP for Transference- Focused Psychotherapy, and so on. The data thus far support the utility of each method, but do not show clear-cut superiority of any one method. A large percentage of BPD patients eventually improve or even recover, but these favorable results appear to derive from a multiplicity of factors. These include the personality traits of both patient and therapist, the unpredictable life events over time, the socioeconomic and cultural background of the patient, and the placebo effect of simply being in treatment. These latter factors constitute the contextual model, which operates alongside the medical model, each playing a role in eventual outcome. The contextual model will be discussed extensively in a separate article.

  2. Human Factors and Medical Devices

    International Nuclear Information System (INIS)

    Dick Sawyer

    1998-01-01

    Medical device hardware- and software-driven user interfaces should be designed to minimize the likelihood of use-related errors and their consequences. The role of design-induced errors in medical device incidents is attracting widespread attention. The U.S. Food and Drug Administration (FDA) is fully cognizant that human factors engineering is critical to the design of safe medical devices, and user interface design is receiving substantial attention by the agency. Companies are paying more attention to the impact of device design, including user instructions, upon the performance of those health professionals and lay users who operate medical devices. Concurrently, the FDA is monitoring human factors issues in its site inspections, premarket device approvals, and postmarket incident evaluations. Overall, the outlook for improved designs and safer device operation is bright

  3. Significance evaluation in factor graphs

    DEFF Research Database (Denmark)

    Madsen, Tobias; Hobolth, Asger; Jensen, Jens Ledet

    2017-01-01

    in genomics and the multiple-testing issues accompanying them, accurate significance evaluation is of great importance. We here address the problem of evaluating statistical significance of observations from factor graph models. Results Two novel numerical approximations for evaluation of statistical...... significance are presented. First a method using importance sampling. Second a saddlepoint approximation based method. We develop algorithms to efficiently compute the approximations and compare them to naive sampling and the normal approximation. The individual merits of the methods are analysed both from....... Conclusions The applicability of saddlepoint approximation and importance sampling is demonstrated on known models in the factor graph framework. Using the two methods we can substantially improve computational cost without compromising accuracy. This contribution allows analyses of large datasets...

  4. Strange mesonic transition form factor

    International Nuclear Information System (INIS)

    Goity, J.L.; Musolf, M.J.

    1996-01-01

    The strange-quark vector current ρ-to-π meson transition form factor is computed at one-loop order using strange meson intermediate states. A comparison is made with a φ-meson dominance model estimate. We find that one-loop contributions are comparable in magnitude to those predicted by φ-meson dominance. It is possible that the one-loop contribution can make the matrix element as large as those of the electromagnetic current mediating vector meson radiative decays. However, due to the quadratic dependence of the one-loop results on the hadronic form factor cutoff mass, a large uncertainty in the estimate of the loops is unavoidable. These results indicate that non-nucleonic strange quarks could contribute appreciable in moderate-parallel Q 2 parallel parity-violating electron-nucleus scattering measurements aimed at probing the strange-quark content of the nucleon. copyright 1996 The American Physical Society

  5. Campylobacter virulence and survival factors.

    Science.gov (United States)

    Bolton, Declan J

    2015-06-01

    Despite over 30 years of research, campylobacteriosis is the most prevalent foodborne bacterial infection in many countries including in the European Union and the United States of America. However, relatively little is known about the virulence factors in Campylobacter or how an apparently fragile organism can survive in the food chain, often with enhanced pathogenicity. This review collates information on the virulence and survival determinants including motility, chemotaxis, adhesion, invasion, multidrug resistance, bile resistance and stress response factors. It discusses their function in transition through the food processing environment and human infection. In doing so it provides a fundamental understanding of Campylobacter, critical for improved diagnosis, surveillance and control. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Human Factors in Space Exploration

    Science.gov (United States)

    Jones, Patricia M.; Fiedler, Edna

    2010-01-01

    The exploration of space is one of the most fascinating domains to study from a human factors perspective. Like other complex work domains such as aviation (Pritchett and Kim, 2008), air traffic management (Durso and Manning, 2008), health care (Morrow, North, and Wickens, 2006), homeland security (Cooke and Winner, 2008), and vehicle control (Lee, 2006), space exploration is a large-scale sociotechnical work domain characterized by complexity, dynamism, uncertainty, and risk in real-time operational contexts (Perrow, 1999; Woods et ai, 1994). Nearly the entire gamut of human factors issues - for example, human-automation interaction (Sheridan and Parasuraman, 2006), telerobotics, display and control design (Smith, Bennett, and Stone, 2006), usability, anthropometry (Chaffin, 2008), biomechanics (Marras and Radwin, 2006), safety engineering, emergency operations, maintenance human factors, situation awareness (Tenney and Pew, 2006), crew resource management (Salas et aI., 2006), methods for cognitive work analysis (Bisantz and Roth, 2008) and the like -- are applicable to astronauts, mission control, operational medicine, Space Shuttle manufacturing and assembly operations, and space suit designers as they are in other work domains (e.g., Bloomberg, 2003; Bos et al, 2006; Brooks and Ince, 1992; Casler and Cook, 1999; Jones, 1994; McCurdy et ai, 2006; Neerincx et aI., 2006; Olofinboba and Dorneich, 2005; Patterson, Watts-Perotti and Woods, 1999; Patterson and Woods, 2001; Seagull et ai, 2007; Sierhuis, Clancey and Sims, 2002). The human exploration of space also has unique challenges of particular interest to human factors research and practice. This chapter provides an overview of those issues and reports on sorne of the latest research results as well as the latest challenges still facing the field.

  7. Congenital deficiency of factor VII.

    Science.gov (United States)

    Sikka, M; Gomber, S; Madan, N; Rusia, U; Sharma, S

    1996-01-01

    A case of congenital factor VII deficiency in a five-year-old child is reported. The patient, born of a non-consanguineous marriage, presented with repeated bouts of epistaxis since childhood. The prothrombin time (PT) was markedly prolonged with a normal bleeding time (BT), partial thromboplastin time with Kaolin (PTTK) and platelet count. The patient has been on follow up for the last four years and is doing apparently well.

  8. Factoría Eternit

    Directory of Open Access Journals (Sweden)

    Waltenspuhl, Paul

    1959-10-01

    Full Text Available A pesar de las sucesivas ampliaciones que ha venido realizando la firma comercial de productos de amianto-cemento Eternit en su factoría de Niederurnen, y como consecuencia del natural aumento de su producción, había llegado un momento en que sus instalaciones resultaron insuficientes para poder atender las demandas de sus usuarios, seis veces superiores a las del año 1939.

  9. HIV: Social and Environmental Factors

    Centers for Disease Control (CDC) Podcasts

    2012-02-01

    Dr. Kevin Fenton, Director of CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, discusses how social and environmental factors may put African Americans at greater risk for HIV.  Created: 2/1/2012 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 2/1/2012.

  10. Islamic factor in contemporary Russia

    OpenAIRE

    N. M. Shalenna

    2014-01-01

    Russian Federation, a Eurasian multinational state, has a significant number of indigenous Muslim population (about 10%) that continues to increase not only due to natural growth and conversion of non-Muslims to Islam, but also as a result of intensive immigration from the Central Asian countries and Azerbaijan. Islamic factor significantly predetermined policy of Russia during its historical development. The importance of Islam in contemporary political life has been underlined by many gover...

  11. Asma bronquial: factores de riesgo de las crisis y factores preventivos Bronchial asthma: risk factors of crises and preventive factors

    Directory of Open Access Journals (Sweden)

    Anselmo Abdo Rodríguez

    2007-09-01

    Full Text Available En los últimos años, y con motivo de los avances que se realizan en el campo de la investigación del asma bronquial, los conceptos en su prevención han ido cambiando entre los especialistas que lo tratan. Este trabajo tiene como objetivo llevar el conocimiento básico necesario a los profesionales de la medicina, para que a cada paciente asmático, atendido por primera vez, se le determinen los alergenos desencadenantes, los factores agravantes y socioculturales que le rodean y que pueden estar afectándolo. Se aborda la sensibilización a alergenos desde la etapa embrionaria y lactancia en el niño atópico, cuándo debemos considerar a un niño con alto riesgo alérgico, los factores de riesgo más importantes, con experiencias prácticas en el Hospital Universitario “Calixto García”, y las recomendaciones para la prevención de las enfermedades alérgicas en lactantes e infantes de alto riesgo alérgico.En recent years and advances in research field of bronchial asthma, features in its prevention has been changing among specialists treating it. Aim of this paper is to transmit the basic and necessary knowledge to medicine professionals for that in each asthmatic patient treated for the first time, the triggering allergens, aggravating factors, and the surrounded sociocultural ones, affecting him be determined. Authors approach sensitivity to allergens from embryonic stage and the lactation in atopic child, when we must to consider the case of an allergic and in high risk child, the more significant risk factors, with practical experiences in “Calixto García” University Hospital, and recommendations for preventions of allergic diseases in infants and breast-fed child in high risk of allergy.

  12. Insomnia: prevalence and associated factors

    OpenAIRE

    Lopes, Cátia; Lopes, Daniela; Ferreira, Sofia; Correia, Teresa; Pinto, Isabel C.

    2014-01-01

    Nowadays sleep disorders are very common and affect most of the population, the most common may be insomnia. Insomnia is defined as the difficulty of initiating or maintaining sleep it, may also be reflected in an early wake up and by the presence of a non-restful sleep and it is associated with impairment in social and occupational functioning of the individual. Knowing the prevalence and the associated factors of insomnia. This is a cross-sectional epidemiological study. The pop...

  13. Human factors in waste management

    Energy Technology Data Exchange (ETDEWEB)

    Moray, N. [Univ. of Illinois, Urbana, IL (United States)

    1994-10-01

    This article examines the role of human factors in radioactive waste management. Although few problems and ergonomics are special to radioactive waste management, some problems are unique especially with long term storage. The entire sociotechnical system must be looked at in order to see where improvement can take place because operator errors, as seen in Chernobyl and Bhopal, are ultimately the result of management errors.

  14. Performance conditional factors in rowing

    OpenAIRE

    Penichet-Tomás, Alfonso; Pueo, Basilio

    2017-01-01

    Literature has established strong relationships between some anthropometric and strength measures with rowing performance. However these studies have not correlated rower’s success with absolute (watt average) and relative weight values (watts per unit weight). The aim of this study was to correlate performance and efficiency in rowing with anthropometric and strength factors. Twenty-two elite rowers (11 male and 11 female) volunteered to participate in this study. Anthropometric measurements...

  15. Psychological factors affecting equine performance

    OpenAIRE

    McBride, Sebastian D; Mills, Daniel S

    2012-01-01

    Abstract For optimal individual performance within any equestrian discipline horses must be in peak physical condition and have the correct psychological state. This review discusses the psychological factors that affect the performance of the horse and, in turn, identifies areas within the competition horse industry where current behavioral research and established behavioral modification techniques could be applied to further enhance the performance of animals. In particular, the role of af...

  16. Factorizing the time evolution operator

    International Nuclear Information System (INIS)

    Garcia Quijas, P C; Arevalo Aguilar, L M

    2007-01-01

    There is a widespread belief in the quantum physical community, and textbooks used to teach quantum mechanics, that it is a difficult task to apply the time evolution operator e itH-hat/h on an initial wavefunction. Because the Hamiltonian operator is, generally, the sum of two operators, then it is not possible to apply the time evolution operator on an initial wavefunction ψ(x, 0), for it implies using terms like (a-hat + b-hat). A possible solution is to factorize the time evolution operator and then apply successively the individual exponential operator on the initial wavefunction. However, the exponential operator does not directly factorize, i.e. e a-hat+b-hat ≠ e a-hat e b-hat . In this study we present a useful procedure for factorizing the time evolution operator when the argument of the exponential is a sum of two operators, which obey specific commutation relations. Then, we apply the exponential operator as an evolution operator for the case of elementary unidimensional potentials, like a particle subject to a constant force and a harmonic oscillator. Also, we discuss an apparent paradox concerning the time evolution operator and non-spreading wave packets addressed previously in the literature

  17. Tissue Factor Structure and Function

    Directory of Open Access Journals (Sweden)

    Saulius Butenas

    2012-01-01

    Full Text Available Tissue factor (TF is an integral membrane protein that is essential to life. It is a component of the factor VIIa-TF complex enzyme and plays a primary role in both normal hemostasis and thrombosis. With a vascular injury, TF becomes exposed to blood and binds plasma factor VIIa, and the resulting complex initiates a series of enzymatic reactions leading to clot formation and vascular sealing. Many cells, both healthy, and tumor cells, produce detectable amounts of TF, especially when they are stimulated by various agents. Despite the relative simplicity and small size of TF, there are numerous contradictory reports about the synthesis and presentation of TF on blood cells and circulation in normal blood either on microparticles or as a soluble protein. Another subject of controversy is related to the structure/function of TF. It has been almost commonly accepted that cell-surface-associated TF has low (if any activity, that is, is “encrypted” and requires specific conditions/reagents to become active, that is, “decrypted.” However there is a lack of agreement related to the mechanism and processes leading to alterations in TF function. In this paper TF structure, presentation, and function, and controversies concerning these features are discussed.

  18. Human Factors in Financial Trading

    Science.gov (United States)

    Leaver, Meghan; Reader, Tom W.

    2016-01-01

    Objective This study tests the reliability of a system (FINANS) to collect and analyze incident reports in the financial trading domain and is guided by a human factors taxonomy used to describe error in the trading domain. Background Research indicates the utility of applying human factors theory to understand error in finance, yet empirical research is lacking. We report on the development of the first system for capturing and analyzing human factors–related issues in operational trading incidents. Method In the first study, 20 incidents are analyzed by an expert user group against a referent standard to establish the reliability of FINANS. In the second study, 750 incidents are analyzed using distribution, mean, pathway, and associative analysis to describe the data. Results Kappa scores indicate that categories within FINANS can be reliably used to identify and extract data on human factors–related problems underlying trading incidents. Approximately 1% of trades (n = 750) lead to an incident. Slip/lapse (61%), situation awareness (51%), and teamwork (40%) were found to be the most common problems underlying incidents. For the most serious incidents, problems in situation awareness and teamwork were most common. Conclusion We show that (a) experts in the trading domain can reliably and accurately code human factors in incidents, (b) 1% of trades incur error, and (c) poor teamwork skills and situation awareness underpin the most critical incidents. Application This research provides data crucial for ameliorating risk within financial trading organizations, with implications for regulation and policy. PMID:27142394

  19. College factors that influence drinking.

    Science.gov (United States)

    Presley, Cheryl A; Meilman, Philip W; Leichliter, Jami S

    2002-03-01

    The purpose of this article is to examine the aspects of collegiate environments, rather than student characteristics, that influence drinking. Unfortunately, the existing literature is scant on this topic. A literature review of articles primarily published within the last 10 years, along with some earlier "landmark" studies of collegiate drinking in the United States, was conducted to determine institutional factors that influence the consumption of alcohol. In addition, a demonstration analysis of Core Alcohol and Drug Survey research findings was conducted to further elucidate the issues. Several factors have been shown to relate to drinking: (1) organizational property variables of campuses, including affiliations (historically black institutions, women's institutions), presence of a Greek system, athletics and 2- or 4-year designation; (2) physical and behavioral property variables of campuses, including type of residence, institution size, location and quantity of heavy episodic drinking; and (3) campus community property variables, including pricing and availability and outlet density. Studies, however, tend to look at individual variables one at a time rather than in combination (multivariate analyses). Some new analyses, using Core Alcohol and Drug Survey data sets, are presented as examples of promising approaches to future research. Given the complexities of campus environments, it continues to be a challenge to the field to firmly establish the most compelling institutional and environmental factors relating to high-risk collegiate drinking.

  20. Factors Influencing Learner Permit Duration

    Directory of Open Access Journals (Sweden)

    Johnathon P. Ehsani

    2016-12-01

    Full Text Available An increasing number of countries are requiring an extended learner permit prior to independent driving. The question of when drivers begin the learner permit period, and how long they hold the permit before advancing to independent licensure has received little research attention. Licensure timing is likely to be related to “push” and “pull” factors which may encourage or inhibit the process. To examine this question, we recruited a sample of 90 novice drivers (49 females and 41 males, average age of 15.6 years soon after they obtained a learner permit and instrumented their vehicles to collect a range of driving data. Participants completed a series of surveys at recruitment related to factors that may influence licensure timing. Two distinct findings emerged from the time-to-event analysis that tested these push and pull factors in relation to licensure timing. The first can be conceptualized as teens’ motivation to drive (push, reflected in a younger age when obtaining a learner permit and extensive pre-permit driving experience. The second finding was teens’ perceptions of their parents’ knowledge of their activities (pull; a proxy for a parents’ attentiveness to their teens’ lives. Teens who reported higher levels of their parents’ knowledge of their activities took longer to advance to independent driving. These findings suggest time-to-licensure may be related to teens’ internal motivation to drive, and the ability of parents to facilitate or impede early licensure.

  1. Dietary factors affecting polyphenol bioavailability.

    Science.gov (United States)

    Bohn, Torsten

    2014-07-01

    While many epidemiological studies have associated the consumption of polyphenols within fruits and vegetables with a decreased risk of developing several chronic diseases, intervention studies have generally not confirmed these beneficial effects. The reasons for this discrepancy are not fully understood but include potential differences in dosing, interaction with the food matrix, and differences in polyphenol bioavailability. In addition to endogenous factors such as microbiota and digestive enzymes, the food matrix can also considerably affect bioaccessibility, uptake, and further metabolism of polyphenols. While dietary fiber (such as hemicellulose), divalent minerals, and viscous and protein-rich meals are likely to cause detrimental effects on polyphenol bioaccessibility, digestible carbohydrates, dietary lipids (especially for hydrophobic polyphenols, e.g., curcumin), and additional antioxidants may enhance polyphenol availability. Following epithelial uptake, polyphenols such as flavonoids may reduce phase II metabolism and excretion, enhancing polyphenol bioavailability. Furthermore, polyphenols may act synergistically due to their influence on efflux transporters such as p-glycoprotein. In order to understand polyphenol bioactivity, increased knowledge of the factors affecting polyphenol bioavailability, including dietary factors, is paramount. © 2014 International Life Sciences Institute.

  2. Thrombosis and von Willebrand Factor.

    Science.gov (United States)

    Shahidi, Minoo

    2017-01-01

    One of the key players in both hemostasis and thrombosis is von Willebrand factor (vWF), which demonstrates a duality between these two processes. Thrombus is structured by numerous elements, including endothelial cells, platelets, plasma proteins and shear stress alteration. In circulation, once a vessel wall is injured, collagen is exposed and platelets attach to the site of injury. Accordingly, vWF mediates adherence of platelets to the damaged vessel wall by binding both to the collagen and platelet receptor. A growing body of data also indicates a role for neutrophil extracellular traps (NETs) in human thrombosis as scaffolds for vWF, promoting thrombosis. VWF also mediates the protection of factor VIII, a main cofactor of the intrinsic clotting pathway. Since vWF plays a critical role in both thrombotic and bleeding events, a decreased plasma level of this factor may point to a bleeding disorder, while an elevated plasma level may predict occurrence of thrombosis. Since thrombotic events are the foremost cause of death, inhibiting the vWF activity would be a novel prophylaxis to reduce these events. Though, accumulated data have made vWF a promising focus for research on cardiovascular diseases (CVD). This chapter, however, aims to clarify the role of vWF in thrombus formation and pathogenesis of thrombosis.

  3. Column: Factors Affecting Data Decay

    Directory of Open Access Journals (Sweden)

    Kevin Fairbanks

    2012-06-01

    Full Text Available In nuclear physics, the phrase decay rate is used to denote the rate that atoms and other particles spontaneously decompose. Uranium-235 famously decays into a variety of daughter isotopes including Thorium and Neptunium, which themselves decay to others. Decay rates are widely observed and wildly different depending on many factors, both internal and external. U-235 has a half-life of 703,800,000 years, for example, while free neutrons have a half-life of 611 seconds and neutrons in an atomic nucleus are stable.We posit that data in computer systems also experiences some kind of statistical decay process and thus also has a discernible decay rate. Like atomic decay, data decay fluctuates wildly. But unlike atomic decay, data decay rates are the result of so many different interplaying processes that we currently do not understand them well enough to come up with quantifiable numbers. Nevertheless, we believe that it is useful to discuss some of the factors that impact the data decay rate, for these factors frequently determine whether useful data about a subject can be recovered by forensic investigation.(see PDF for full column

  4. Factors Influencing New Business Formation

    Directory of Open Access Journals (Sweden)

    Andreea-Oana Iacobuţă

    2016-05-01

    Full Text Available The purpose of this study is to identify the factors that influence the creation of new businesses and to point out both the differences and the similarities existing between countries and groups of countries in terms of these influencing factors. We are mainly interested in the place Romania and Bulgaria have among the countries of the world from the perspective of entrepreneurial spirit and its influencing factors. To capture the level of business formation we use New business density from World Bank Doing business. Drawing on the existing literature we consider for our analysis several indicators related to economic environment such as GDP per capita, unemployment rate, inflation rate, the level of taxes, foreign direct investments and public debt and indicators describing the quality of governance. The research uses 2014 data for 67 countries, from all development categories, collected from Heritage Foundation database. The research results obtained with principal components analysis show that good governance results in higher levels of GDP per capita and income taxes and the increase of the level of business formation. Also, good governance leads to a decrease in inflation and unemployment. Furthermore, the hierarchical cluster analysis is used to identify groups of countries and to outline similarities and differences between them.

  5. Factors that affect keratotomy depth.

    Science.gov (United States)

    Merlin, U; Bordin, P; Rimondi, A P; Sichirollo, R

    1991-01-01

    The authors investigated nine factors which can affect the depth of incisions performed during refractive keratotomy: (1) vertical vs oblique-cutting edge of the knife blade, (2) direction of cutting, (3) cutting velocity, (4) American vs Russian technique, (5) intraocular pressure (IOP), (6) initial vs final incisions, (7) sharpness of knife blade, (8) single vs double footplate, and (9) square vs double-edged blade. These variables were examined independently, performing at least 40 incisions for each experimental parameter studied. The depth of the resulting incisions was measured histologically using the micrometer eyepiece. The average and the standard deviation were calculated. The paired Student's t-test was used to establish significant differences between the two conditions investigated for each parameter. Factors that were demonstrated to increase significantly the depth of the incisions included: the vertical-cutting edge, the triple-edged diamond knife, the sharpness of the knife, and the single foot knife. High velocity in performing the incisions and, to a lesser extent, low IOP were the main factors that induced irregularity in depth.

  6. Factors associated with secondary infertility

    Directory of Open Access Journals (Sweden)

    Hasina Momtaz

    2011-01-01

    Full Text Available Infertility is an experience that strikes at the very core of a woman’s life and as a whole her family and society. Studies in Bangladesh to evaluate the factors are difficult to come by. This case control study was carried out from Jan 2010 to June 2010 to find out the factors associated with secondary infertility. A total of 70 cases were selected from the infertility unit of Bangabandhu Sheikh Mujib Medical University and 70 unmatched controls from the same hospital attending the pediatrics unit with their children were also recruited. Data were collected by interview and review of documents. No age difference was noticed between the cases (29.26 ± 4.13 and controls (29.21 ± 3.95. Association of secondary infertility was found with body mass index (p=0.036, previous bad obstetric history (p = 0.011 and previous caesarian delivery (p=0.044. Women with secondary infertility were more than four times more likely to have gynecological problem(s than their fertile counterparts [OR 4.76 with 95% CI (2.018-11.270]. The factors identified in this study might help the policy makers in designing prevention and health care programmes and thus reducing the hidden burden of secondary infertility. Ibrahim Med. Coll. J. 2011; 5(1: 17-21

  7. EM Form Factors and OLYMPUS

    Directory of Open Access Journals (Sweden)

    Kohl Michael

    2014-01-01

    Full Text Available The elastic form factors of the nucleon characterize the distributions of charge and magnetization in momentum space and are important input for calculations of strong interaction phenomena and nuclear structure. The dramatic discrepancy in the observed ratio of elastic proton form factors between the Rosenbluth separation and polarization transfer methods has invoked numerous theoretical and experimental investigations. The previously neglected effect from two-photon exchange has become the favored explanation for the discrepancy. While the effect can not be calculated from first principles, it can be verified experimentally in several ways, most stringently by comparing the positron- proton and electron-proton elastic cross sections. The OLYMPUS experiment at DESY has been carried out to quantify the effect of two-photon exchange using intense stored positron and electron beams along with an internal unpolarized hydrogen target and a large acceptance detector to measure the ratio of the positron-proton and electron-proton elastic scattering cross sections. The status of proton form factor measurements and of the experimental efforts to verify the effect of two-photon exchange is presented, with some emphasis on the OLYMPUS experiment.

  8. "Risk factors of birth asphyxia".

    Science.gov (United States)

    Aslam, Hafiz Muhammad; Saleem, Shafaq; Afzal, Rafia; Iqbal, Umair; Saleem, Sehrish Muhammad; Shaikh, Muhammad Waqas Abid; Shahid, Nazish

    2014-12-20

    Birth asphyxia is an insult to the fetus or newborn due to failure to breath or breathing poorly, leads to decrease oxygen perfusion to various organs. According to WHO, 4 million neonatal deaths occurred each year due to birth asphyxia. Our goal was to evaluate antepartum, intrapartum, and fetal risk factors of birth asphyxia. It was a Retrospective Case control study, conducted at Neonatal Intensive Care Unit of pediatric ward (I, II, III) and in Gynecology wards (I, II, III) of Civil Hospital Karachi, Dow University of Health Sciences. Study was conducted from January 2011-November 2012. Neonates diagnosed with birth asphyxia were considered as "cases" while neonates born either with normal vaginal delivery or by cesarean section having no abnormality were considered as "control". Demographics of both the mother and neonate were noted and Questions regarding possible risk factors were asked from mother. Ethical issues were confirmed from Institutional review board of Civil Hospital Karachi, Dow University of Health Sciences. All data was entered and analyzed through SPSS 19. Out of total 240 neonates, 123 were "cases" and 117 were "control". Mean maternal age in "case" group was 24.22 ± 3.38 while maternal age of control group was 24.30 ± 4.04. Significant antepartum risk factors were maternal age of 20-25 (OR 0.30 CI 95% 0.07-1.21), booking status (OR 0.20 CI 95% 0.11-0.37), pre-eclampsia (OR 0.94 CI 95% 0.90-0.98) and primigravidity (OR 2.64 CI 95% 1.56-4.46). Significant Intrapartum risk factors were breech presentation (OR 2.96 CI 95% 1.25-7.02), home delivery (OR 16.16 CI 95% 3.74-69.75) and maternal fever (OR 10.01 CI95% 3.78-26.52). Significant Fetal risk factors were resuscitation of child (OR 23 CI 95% 31.27-1720.74), pre-term babies(OR 0.34 CI 95% 0.19-0.58), fetal distress (OR 0.01 CI 95% 0.00-0.11) and baby weight (OR 0.13 CI 95% 0.05-0.32). Measures should be taken to prevent neonatal mortality with great emphasis on skilled attendance at birth

  9. Tissue uptake, distribution and elimination of {sup 14}C-PFOA in zebrafish (Danio rerio)

    Energy Technology Data Exchange (ETDEWEB)

    Ulhaq, Mazhar [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden); Sundström, Maria [Environmental Chemistry Unit, Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm (Sweden); Larsson, Pia; Gabrielsson, Johan [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden); Bergman, Åke [Environmental Chemistry Unit, Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm (Sweden); Norrgren, Leif [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden); Örn, Stefan, E-mail: Stefan.Orn@slu.se [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden)

    2015-06-15

    Highlights: • Bioconcentration of PFOA at steady-state was approximately 20–30 times. • High concentrations were observed in bile and intestines implying enterohepatic circulation. • PFOA accumulated in oocytes indicating maternal transfer. - Abstract: Perfluorooctanoic acid (PFOA) is a long-chain perfluorinated chemical that has been shown to be non-degradable and persistent in the environment. Laboratory studies on bioconcentration and compound-specific tissue distribution in fish can be valuable for prediction of the persistence and environmental effects of the chemicals. In the present study male and female zebrafish (Danio rerio) were continuously exposed to 10 μg/L of radiolabeled perfluorooctanoic acid ({sup 14}C-PFOA) for 40 days, after which the exposed fish were transferred to fresh clean water for another 80 days wash-out period. At defined periodic intervals during the uptake and wash-out, fish were sampled for liquid scintillation counting and whole body autoradiography to profile the bioconcentration and tissue distribution of PFOA. The steady-state concentration of {sup 14}C-PFOA in the zebrafish was reached within 20–30 days of exposure. The concentration-time course of {sup 14}C-PFOA displayed a bi-exponential decline during washout, with a terminal half-life of approximately 13–14 days. At steady-state the bioconcentration of {sup 14}C-PFOA into whole-body fish was approximately 20–30 times greater than that of the exposure concentration, with no differences between females and males. The bioconcentration factors for liver and intestine were approximately 100-fold of the exposure medium, while in brain, ovary and gall bladder the accumulation factors were in the range 15–20. Whole-body autoradiograms confirmed the highest labeling of PFOA in bile and intestines, which implies enterohepatic circulation of PFOA. The {sup 14}C-PFOA was also observed in maturing vitellogenic oocytes, suggesting chemical accumulation via yolk proteins

  10. Factors affecting dental service quality.

    Science.gov (United States)

    Bahadori, Mohammadkarim; Raadabadi, Mehdi; Ravangard, Ramin; Baldacchino, Donia

    2015-01-01

    Measuring dental clinic service quality is the first and most important factor in improving care. The quality provided plays an important role in patient satisfaction. The purpose of this paper is to identify factors affecting dental service quality from the patients' viewpoint. This cross-sectional, descriptive-analytical study was conducted in a dental clinic in Tehran between January and June 2014. A sample of 385 patients was selected from two work shifts using stratified sampling proportional to size and simple random sampling methods. The data were collected, a self-administered questionnaire designed for the purpose of the study, based on the Parasuraman and Zeithaml's model of service quality which consisted of two parts: the patients' demographic characteristics and a 30-item questionnaire to measure the five dimensions of the service quality. The collected data were analysed using SPSS 21.0 and Amos 18.0 through some descriptive statistics such as mean, standard deviation, as well as analytical methods, including confirmatory factor. Results showed that the correlation coefficients for all dimensions were higher than 0.5. In this model, assurance (regression weight=0.99) and tangibility (regression weight=0.86) had, respectively, the highest and lowest effects on dental service quality. The Parasuraman and Zeithaml's model is suitable to measure quality in dental services. The variables related to dental services quality have been made according to the model. This is a pioneering study that uses Parasuraman and Zeithaml's model and CFA in a dental setting. This study provides useful insights and guidance for dental service quality assurance.

  11. Time factors in radiation carcinogenesis

    International Nuclear Information System (INIS)

    Sasaki, Shunsaku

    1995-01-01

    Results of experiments using B6C3F 1 female mice were made subject of analysis on the time factors in radiation carcinogenesis. In the experiment for examination of influence of age at irradiation on the lifetime risk and on distribution of ages at death, mice were irradiated at day 12, 14 or 17 of the prenatal period, or day 0, 7, 35, 105, 240 or 365 of the postnatal period with doses ranging from 0.48 to 5.7 Gy gamma-rays from 137 Cs. In the experiment to examine the reduction factor for carcinogenic effect by multiple fractionation of gamma-rays dose 1.9 or 3.8 Gy was divided into 10 fractions, which were delivered once a week during period from 5 to 15 weeks of age. All mice were allowed to live out their life spans under a specific pathogen free condition. The cumulative relative risk for mortality from all causes except lymphoma and leukemia was shown to decrease with age when mice were irradiated at the fetal, neonatal, suckling, adolescent or young adult period, whereas, the decrease in the cumulative relative risk was very little when gamma-rays were given at the intermediate adult period. The lifetime risk for the increase in mortality and for the induction of solid tumors was highest in mice irradiated during neonatal, suckling or adolescent period. Age-dependence of susceptibility to radiation carcinogenesis was different for each type of neoplasm. However, the most susceptible period for induction of each type of neoplasm concentrated in the age from neonatal to adolescent period. Radiation-induced late effects were apparently reduced by multiple fractionation of radiation dose, but the reduction factor for the increase in the long-term mortality did not exceed 2.0. (author)

  12. Boltzmann factor and Hawking radiation

    International Nuclear Information System (INIS)

    Ryskin, Gregory

    2014-01-01

    Hawking radiation has thermal spectrum corresponding to the temperature T H =(8πM) −1 , where M is the mass (energy) of the black hole. Corrections to the Hawking radiation spectrum were discovered by Kraus and Wilczek (1995) and Parikh and Wilczek (2000). Here I show that these corrections follow directly from the basic principles of thermodynamics and statistical mechanics. In essence, it is the Boltzmann factor that ought to be corrected; corrections to the Hawking (or any other) radiation spectrum then follow necessarily

  13. Pion form factor in QCD

    International Nuclear Information System (INIS)

    Radyushkin, A.V.

    1980-01-01

    The calculation of the next-to-leading order corrections to pion form factor Fsub(π)(Q) in the QCD shows that analysis of Fsub(π)(Q) is not a short-distance problem up to Q 2 =10 4 -10 6 GeV 2 . A QCD-inspired model is proposed which in a semi-phenomenological way, takes into account the most important confinement effects. The curve obtained for Fsub(π)(Q) is in good agreement with existing experimental data

  14. Geological Factors and Health Problems

    Directory of Open Access Journals (Sweden)

    Francisco Prieto García

    2013-06-01

    Full Text Available Geological factors, such as damages, can cause health determinants in people, which were a little-studied and if they have been raised on occasion, usually referred to no communicable diseases. The aim of this work, which is a more or less updated bibliography, has been to develop a holistic idea for a better understanding of a problem and force latent or potential risk that they can carry and consider scientific basis infectious diseases especially complex.  In essence, the focus of ecosystem health that should be considered in terrestrial ecosystems. It also provides the basic elements for the development of new research in this field.

  15. Oil: economic and political factors

    International Nuclear Information System (INIS)

    Ayoub, A.

    1994-01-01

    This article deals with the evolution of the international petroleum sector since 1973 with a special view to interdependence between the economic and political factors that influence it. Two issues are focused upon: (1) the effects of the nationalization of oil companies on the sharing of oil rents and on changes in the structure of the oil market; and (2) the determination of oil prices. The latter involves a discussion of, on the one hand, the political and economic behaviour of the United States and Saudi Arabia and, on the other, the combination of cooperation and conflict that has tended to characterize relations among OPEC countries. (author). 30 refs

  16. Rheumatoid factor and tobacco exposure

    Directory of Open Access Journals (Sweden)

    Skare Thelma Larocca

    2002-01-01

    Full Text Available This study was carried out to analyse the possible influence of smoking on the positivity of rheumatoid factor (RF in healthy individuals in the region of Curitiba, Brazil. One hundred fifty blood donors (84 smokers and 66 non-smokers were studied for the presence of RF using nephelometry. Smoking was found not to be correlated to the positivity of RF, independently of the smokers sex (men with p=0.09 and women with p=0.49, the number of cigarettes/day (p=0.20, duration of smoking (p=0.18 and cumulative exposure (time X quantity to cigarettes (p=0.13.

  17. Human Factors in Space Flight

    Science.gov (United States)

    Woolford, Barbara J.; Mount, Frances

    2005-01-01

    After forty years of experience with human space flight (Table 1), the current emphasis is on the design of space vehicles, habitats, and missions to ensure mission success. What lessons have we learned that will affect the design of spacecraft for future space exploration, leading up to exploring Mars? This chapter addresses this issue in four sections: Anthropometry and Biomechanics; Environmental Factors; Habitability and Architecture; and Crew Personal Sustenance. This introductory section introduces factors unique to space flight. A unique consideration for design of a habitable volume in a space vehicle is the lack of gravity during a space flight, referred to as microgravity. This affects all aspects of life, and drives special features in the habitat, equipment, tools, and procedures. The difference in gravity during a space mission requires designing for posture and motion differences. In Earth s gravity, or even with partial gravity, orientation is not a variable because the direction in which gravity acts defines up and down. In a microgravity environment the working position is arbitrary; there is no gravity cue. Orientation is defined primarily through visual cues. The orientation within a particular crew station or work area is referred to as local vertical, and should be consistent within a module to increase crew productivity. Equipment was intentionally arranged in various orientations in one module on Skylab to assess the efficiency in use of space versus the effects of inconsistent layout. The effects of that arrangement were confusion on entering the module, time spent in re-orientation, and conflicts in crew space requirements when multiple crew members were in the module. Design of a space vehicle is constrained by the three major mission drivers: mass, volume and power. Each of these factors drives the cost of a mission. Mass and volume determine the size of the launch vehicle directly; they can limit consumables such as air, water, and

  18. Endocrine factors of pair bonding.

    Science.gov (United States)

    Stárka, L

    2007-01-01

    Throughout literature--fiction and poetry, fine arts and music--falling in love and enjoying romantic love plays a central role. While several psychosocial conceptions of pair attachment consider the participation of hormones, human endocrinology has dealt with this theme only marginally. According to some authors in addictology, falling in love shows some signs of hormonal response to stressors with changes in dopamine and serotonin signalling and neurotrophin (transforming growth factor b) concentration. Endorphins, oxytocin and vasopressin may play a role during the later phases of love. However, proof of hormonal events associated with love in humans has, until recently, been lacking.

  19. Factores asociados al destete precoz

    OpenAIRE

    Georgina Peraza Roque; Mercedes Soto Marcelo; Elina de la Llera Suárez; Soraya Alonso Suárez

    1999-01-01

    Se realiza un estudio descriptivo y transversal a 91 niños nacidos entre el 1ro de enero y el 31 de diciembre de 1993, en los 14 consultorios del médico de la familia, pertenecientes a un Grupo Básico de trabajo, del Policlínico Docente "Antonio Maceo" del municipio Cerro, en la Ciudad de La Habana. Se analizaron factores biopsicosociales relacionados con la madre y con el niño. Se confeccionó la base de datos mediante el programa Foxplus, realizándose comparaciones de media y se empleó el mé...

  20. Prognostic Factors in Hodgkin's Disease

    DEFF Research Database (Denmark)

    Specht

    1996-01-01

    Prognostic factors in Hodgkin's disease (HD) are reviewed. The Ann Arbor staging classification remains the basis for evaluation of patients with HD. However, subgroups of patients with differing prognoses exist within the individual stages. In pathological stages I and II, the number of involved...... of extent of disease such as erythrocyte sedimentation rate, anemia, and serum albumin. In advanced disease the number of involved nodal and extranodal regions, the total tumor burden, B symptoms, age, gender, histology, and a number of hematologic and biochemical indicators are significant. Research...

  1. A framework for human factors

    International Nuclear Information System (INIS)

    Webb, R.D.G.

    As the complexity of industrial systems increases, the need for efficient integration of human beings into the systems that they design and operate grows more important. Human factors, or ergonomics, is concerned with the application of life science knowledge about human characteristics to maximise performance and well-being in any context. The most complex problem is to identify job demands in terms of different human dimensions and to apply established life science knowledge to determine optimum solutions. This requires the cooperation of many specialists

  2. Blood coagulation factor VIII: An overview

    Indian Academy of Sciences (India)

    Factor VIII (FVIII) functions as a co-factor in the blood coagulation cascade for the proteolytic activation of factor X by factor IXa. Deficiency of FVIII causes hemophilia A, the most commonly inherited bleeding disorder. This review highlights current knowledge on selected aspects of FVIII in which both the scientist and the ...

  3. 14 CFR 23.621 - Casting factors.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Casting factors. 23.621 Section 23.621... Casting factors. (a) General. The factors, tests, and inspections specified in paragraphs (b) through (d... do not support structural loads. (b) Bearing stresses and surfaces. The casting factors specified in...

  4. 24 CFR 598.305 - Designation factors.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Designation factors. 598.305... Designation Process § 598.305 Designation factors. In choosing among nominated urban areas eligible for... connection with the strategic plan (see § 598.215(b)); and (c) Other factors. Other factors established by...

  5. 14 CFR 25.619 - Special factors.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Special factors. 25.619 Section 25.619... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.619 Special factors. The factor of safety prescribed in § 25.303 must be multiplied by the highest pertinent special factor of safety...

  6. Factors determining lumber recovery in sawmilling

    Science.gov (United States)

    Philip H. Steele

    1984-01-01

    Lumber volume recovery in sawmilling is determined by a confusing interaction of several factors. The more one knows about each individual factor, the more one can understand how the factors interact. The author identifies and discusses in detail seven factors influencing lumber recovery. Past and current research is cited, and examples are given to illustrate the...

  7. Human Factors Checklist: Think Human Factors - Focus on the People

    Science.gov (United States)

    Miller, Darcy; Stelges, Katrine; Barth, Timothy; Stambolian, Damon; Henderson, Gena; Dischinger, Charles; Kanki, Barbara; Kramer, Ian

    2016-01-01

    A quick-look Human Factors (HF) Checklist condenses industry and NASA Agency standards consisting of thousands of requirements into 14 main categories. With support from contractor HF and Safety Practitioners, NASA developed a means to share key HF messages with Design, Engineering, Safety, Project Management, and others. It is often difficult to complete timely assessments due to the large volume of HF information. The HF Checklist evolved over time into a simple way to consider the most important concepts. A wide audience can apply the checklist early in design or through planning phases, even before hardware or processes are finalized or implemented. The checklist is a good place to start to supplement formal HF evaluation. The HF Checklist was based on many Space Shuttle processing experiences and lessons learned. It is now being applied to ground processing of new space vehicles and adjusted for new facilities and systems.

  8. Regulation of Myocyte Enhancer Factor-2 Transcription Factors by Neurotoxins

    Science.gov (United States)

    She, Hua; Mao, Zixu

    2011-01-01

    Various isoforms of myocyte enhancer factor-2 (MEF2) constitute a group of nuclear proteins found to play important roles in increasing types of cells. In neurons, MEF2s are required to regulate neuronal development, synaptic plasticity, as well as survival. MEF2s promote the survival of several types of neurons under different conditions. In cellular models, negative regulation of MEF2s by stress and toxic signals contributes to neuronal death. In contrast, enhancing MEF2 activity not only protects cultured primary neurons from death in vitro but also attenuates the loss of dopaminergic neurons in substantia nigra pars compacta in a 1-methyl 4-phenyl 1,2,3,6-tetrahydropyridine mouse model of Parkinson’s disease. In this work, the mechanisms of regulation of MEF2 function by several well-known neurotoxins and their implications in various neurodegenerative diseases are reviewed. PMID:21741404

  9. Association of factor VII protein concentration with lifestyle factors

    DEFF Research Database (Denmark)

    Bladbjerg, E-M; Møller, L; Jespersen, J

    1998-01-01

    -sectional study examined the association between several behavioural variables (body mass index, physical activity, tobacco or alcohol consumption) or physiological variables (total cholesterol, HDL-cholesterol, triglycerides, glucose, insulin, fibrinogen, resting pulse, systolic blood pressure, bleeding time......) and FVII:Ag in 439 51-y-old Danish men. In the multivariate analyses, body mass index (BMI), low physical activity, total cholesterol, short bleeding time, and insulin showed an independent positive association with FVII:Ag. The strongest independent association with FVII:Ag was found for total cholesterol....... These results suggest that blood lipids are major determinants of FVII:Ag, but that other lifestyle factors such as insulin, BMI and physical activity can also influence FVII:Ag. Furthermore, the association between FVII:Ag and bleeding time suggests an effect of FVII or the FVII pathway on primary haemostasis...

  10. Exploring mobile learning success factors

    Directory of Open Access Journals (Sweden)

    Thomas D. Cochrane

    2010-12-01

    Full Text Available This paper is a comparative account and analysis of three mobile Web 2.0 projects instigated within a tertiary learning environment during 2008. Following the successful instigation of a mobile Web 2.0 project in the third year of a Bachelor of Product Design course during semester one, similar projects were initiated in semester two within the first-year and second-year Bachelor of Product Design courses. A common methodology for supporting and facilitating mobile Web 2.0 projects was used for all three projects. The projects were designed to explore the potential of mobile Web 2.0 tools to enhance both the formal and informal teaching and learning environments with a focus upon mobile blogging (moblogging. A comparison of student and teaching staff feedback from each of the three projects provided a basis for identifying and illustrating critical success factors within similar m-learning scenarios. Critical success factors identified include: the importance of the pedagogical integration of the technology into the course assessment, lecturer modelling of the pedagogical use of the tools, the need for regular formative feedback from lecturers to students, and the appropriate choice of mobile devices and software to support the pedagogical model underlying the course.

  11. Islamic factor in contemporary Russia

    Directory of Open Access Journals (Sweden)

    N. M. Shalenna

    2014-12-01

    Full Text Available Russian Federation, a Eurasian multinational state, has a significant number of indigenous Muslim population (about 10% that continues to increase not only due to natural growth and conversion of non-Muslims to Islam, but also as a result of intensive immigration from the Central Asian countries and Azerbaijan. Islamic factor significantly predetermined policy of Russia during its historical development. The importance of Islam in contemporary political life has been underlined by many government representatives and by the leaders of social and religious organizations and movements. Russian Muslim Ummah nowadays is far from being homogeneous and integrated, that predisposes some groups to radicalization of sentiments, ideas and activities and inevitably causes significant destabilization in the religious, social and political spheres within certain subjects of the Russian Federation and at the national level. The article focuses on the complex investigation of the influence of Islam on the social and political processes in contemporary Russia. It reveals the main principles of the Russian administration policy in the field of religion in general and towards Muslims in particular. Specific features of Muslim communities’ formation and factors of their institutionalization are determined. This research covers the reasons of major contradictions existing within the Russian Ummah. The article stresses on the importance of this study in the context of Ukrainian-Russian conflict in Crimea and in eastern regions of Ukraine. Current policy of Russia towards the Crimean Tatar population is analyzed.

  12. Factors influencing pacing in triathlon

    Directory of Open Access Journals (Sweden)

    Wu SSX

    2014-09-01

    Full Text Available Sam SX Wu,1 Jeremiah J Peiffer,2 Jeanick Brisswalter,3 Kazunori Nosaka,1 Chris R Abbiss1 1Centre for Exercise and Sports Science Research, School of Exercise and Health Sciences, Edith Cowan University, Perth, WA, Australia; 2School of Psychology and Exercise Science, Murdoch University, Perth, WA, Australia; 3Laboratory of Human Motricity, Education Sport and Health, University of Nice Sophia Antipolis, Nice, France Abstract: Triathlon is a multisport event consisting of sequential swim, cycle, and run disciplines performed over a variety of distances. This complex and unique sport requires athletes to appropriately distribute their speed or energy expenditure (ie, pacing within each discipline as well as over the entire event. As with most physical activity, the regulation of pacing in triathlon may be influenced by a multitude of intrinsic and extrinsic factors. The majority of current research focuses mainly on the Olympic distance, whilst much less literature is available on other triathlon distances such as the sprint, half-Ironman, and Ironman distances. Furthermore, little is understood regarding the specific physiological, environmental, and interdisciplinary effects on pacing. Therefore, this article discusses the pacing strategies observed in triathlon across different distances, and elucidates the possible factors influencing pacing within the three specific disciplines of a triathlon. Keywords: cycle, endurance, multisport, pacing strategy, run, swim

  13. Cardiovascular risk factors in men

    DEFF Research Database (Denmark)

    Gyllenborg, J; Rasmussen, S L; Borch-Johnsen, Knut

    2001-01-01

    Males have higher risk of cardiovascular disease (CVD) than premenopausal females. Gonadal steroids are probably involved in the gender difference in CVD, but previous results have been conflicting. We investigated the associations between CVD risk factors and sex hormones in a cross-sectional de......Males have higher risk of cardiovascular disease (CVD) than premenopausal females. Gonadal steroids are probably involved in the gender difference in CVD, but previous results have been conflicting. We investigated the associations between CVD risk factors and sex hormones in a cross......-sectional designed study of 508 healthy males, aged 41 to 72 years. We determined total testosterone (T), sex hormone-binding globulin (SHBG), free androgen index (FAI), and estradiol (E2) and studied their relationship to body fat mass (BF), blood pressure (BP), aortic compliance, left ventricular mass (LVM...... lipids. We suggest that conflicting results of cross-sectional and intervention studies of sex hormones and lipids, in part, may be explained by interindividual differences or changes in SHBG. Thus, further studies on the potential role of SHBG in the development of ischemic heart disease (IHD) should...

  14. Growth factors in cystic fibrosis

    Directory of Open Access Journals (Sweden)

    Negar Khalighi

    2016-01-01

    Full Text Available Introduction: Cystic fibrosis is one of the most common autosomal recessive diseases that affects sweat glands and mucosa. CF is a hereditary disease with annual incidence of about 2500 new cases in United Kingdom. Insulin-like growth factor-1 (IGF-1 and insulin-like growth factor binding protein-3 levels decrease in CF. The aim of this study was to assess the role of growth peptides in patients with CF. Method: We searched PubMed, Google scholar, IranMedex, and Scientific Information Database (SID in September 2012 to April 2014. We included clinical studies with available abstracts and full texts that were in English or Persian languages. Manual searching was conducted within the reference lists of articles. Two reviewers independently applied eligibility criteria, assessed quality, and extracted data.Result: The earliest study was published in 1997 and the most recent one was in 2014. Study participants were adults in 3 studies (20% and 12 studies (80% were conducted in children. Patients with CF have lower levels of IGF-1 and there is a significant correlation between IGF-1 levels and growth index in patients with CF.Conclusions: IGF-1 decreases in children with CF and might be the cause of poor growth and low body mass index in these children.

  15. Factors That Drive Youth Specialization.

    Science.gov (United States)

    Padaki, Ajay S; Popkin, Charles A; Hodgins, Justin L; Kovacevic, David; Lynch, Thomas Sean; Ahmad, Christopher S

    Specialization in young athletes has been linked to overuse injuries, burnout, and decreased satisfaction. Despite continued opposition from the medical community, epidemiological studies suggest the frequency is increasing. Extrinsic pressures in addition to individual aspirations drive this national trend in sports specialization. Descriptive epidemiology study. Level 3. A novel instrument assessing the driving factors behind youth specialization was generated by an interdisciplinary team of medical professionals. Surveys were administered to patients and athletes in the department's sports medicine clinic. The survey was completed by 235 athletes between 7 and 18 years of age, with a mean age of 13.8 ± 3.0 years. Athletes specialized at a mean age of 8.1 years, and 31% of athletes played a single sport while 58% played multiple sports but had a preferred sport. More than 70% of athletes had collegiate or professional ambitions, and 60% played their primary sport for 9 or more months per year, with players who had an injury history more likely to play year-round ( P sports, with specialized athletes reporting this significantly more often ( P = 0.04). Half of the athletes reported that sports interfered with their academic performance, with older players stating this more frequently ( P sport before starting high school. While intrinsic drive may identify healthy aspirations, extrinsic influences are prevalent in specialized athletes. Extrinsic factors contributing to youth specialization were identified and compounded the deleterious sequelae of youth athlete specialization.

  16. Dissecting soft radiation with factorization

    International Nuclear Information System (INIS)

    Stewart, Iain W.; Tackmann, Frank J.; Waalewijn, Wouter J.; Amsterdam Univ.

    2014-05-01

    An essential part of high-energy hadronic collisions is the soft hadronic activity that underlies the primary hard interaction. It can receive contributions from soft radiation from the primary hard partons, secondary multiple parton interactions (MPI), and factorization violating effects. The invariant mass spectrum of the leading jet in Z+jet and H+jet events is directly sensitive to these effects. We use a QCD factorization theorem to predict the dependence on the jet radius R, jet p T , jet rapidity, and partonic process for both the perturbative and nonperturbative components of primary soft radiation. The nonperturbative contributions involve only odd powers of R, and the linear R term is universal for quark and gluon jets. The hadronization model in PYTHIA8 agrees well with these properties. The perturbative soft initial state radiation (ISR) has a contribution that depends on the jet area in the same way as the underlying event. This degeneracy is broken by the jet p T dependence. The size of this soft ISR contribution is proportional to the color state of the initial partons, yielding the same positive contribution for gg→Hg and gq→Zq, but a negative interference contribution for q anti q→Zg. Hence, measuring these dependencies allows one to separate hadronization, soft ISR, and MPI contributions in the data.

  17. Salmonella-secreted Virulence Factors

    Energy Technology Data Exchange (ETDEWEB)

    Heffron, Fred; Niemann, George; Yoon, Hyunjin; Kidwai, Afshan S.; Brown, Roslyn N.; McDermott, Jason E.; Smith, Richard D.; Adkins, Joshua N.

    2011-05-01

    In this short review we discuss secreted virulence factors of Salmonella, which directly affect Salmonella interaction with its host. Salmonella secretes protein to subvert host defenses but also, as discussed, to reduce virulence thereby permitting the bacteria to persist longer and more successfully disperse. The type III secretion system (TTSS) is the best known and well studied of the mechanisms that enable secretion from the bacterial cytoplasm to the host cell cytoplasm. Other secretion systems include outer membrane vesicles, which are present in all Gram-negative bacteria examined to date, two-partner secretion, and type VI secretion will also be addressed. Excellent reviews of Salmonella secreted effectors have focused on themes such as actin rearrangements, vesicular trafficking, ubiquitination, and the activities of the virulence factors themselves. This short review is based on S. Typhimurium infection of mice because it is a model of typhoid like disease in humans. We have organized effectors in terms of events that happen during the infection cycle and how secreted effectors may be involved.

  18. The structure factor of primes

    Science.gov (United States)

    Zhang, G.; Martelli, F.; Torquato, S.

    2018-03-01

    Although the prime numbers are deterministic, they can be viewed, by some measures, as pseudo-random numbers. In this article, we numerically study the pair statistics of the primes using statistical-mechanical methods, particularly the structure factor S(k) in an interval M ≤slant p ≤slant M + L with M large, and L/M smaller than unity. We show that the structure factor of the prime-number configurations in such intervals exhibits well-defined Bragg-like peaks along with a small ‘diffuse’ contribution. This indicates that primes are appreciably more correlated and ordered than previously thought. Our numerical results definitively suggest an explicit formula for the locations and heights of the peaks. This formula predicts infinitely many peaks in any non-zero interval, similar to the behavior of quasicrystals. However, primes differ from quasicrystals in that the ratio between the location of any two predicted peaks is rational. We also show numerically that the diffuse part decays slowly as M and L increases. This suggests that the diffuse part vanishes in an appropriate infinite-system-size limit.

  19. Human factors in contingency operations.

    Science.gov (United States)

    Mercer, Simon J; Khan, M A; Scott, T; Matthews, J J; Henning, Dcw; Stapley, S

    2017-04-01

    The UK Defence Medical Services are currently supporting contingency operations following a period of intensive activity in relatively mature trauma systems in Iraq and Afghanistan. Among the key lessons identified, human factors or non-technical skills played an important role in the improvement of patient care. This article describes the importance of human factors on Role 2 Afloat, one of the Royal Navy's maritime contingency capabilities, and illustrates how they are vital to ensuring that correct decisions are made for patient care in a timely manner. Teamwork and communication are particularly important to ensure that limited resources such as blood products and other consumables are best used and that patients are evacuated promptly, allowing the facility to accept further casualties and therefore maintain operational capability. These ideas may be transferred to any small specialist team given a particular role to perform. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. TRUST - A FACTOR OF PRODUCTION

    Directory of Open Access Journals (Sweden)

    Prunea Petru

    2011-12-01

    Full Text Available The economic activity is more and more influenced by the condition and the evolution of some immaterial and non-financial elements which exist in a firm or a country. One of these elements - information - has unanimously been accepted as the 4th production factor. In this paper I try to demonstrate that trust too, has to be accepted as a production factor. Especially as it fulfils the fundamental conditions for this to happen : it is infinitly divisible and homogeneous and, thus, its marginal product can be calculated. In nowadays world, characterized by the apparently unstoppable expansion of the cruel individualism and of market fundamentalism, which have undermined the trust in the success of private initiative, producers increasingly need community, need another mode of involvement of the state in economy and they need another way of relating to each other. The costs resulting from the diminishing of trust have become so significant that their transformation into income is necessary, if we succeed in basing ourselves on trust in the economic process.

  1. Methodology of human factor analysis

    International Nuclear Information System (INIS)

    Griffon-Fouco, M.

    1988-01-01

    The paper describes the manner in which the Heat Production Department of Electricite de France analyses the human factors in nuclear power plants. After describing the teams and structures set up to deal with this subject, the paper emphasizes two types of methods which are used, most often in complementary fashion: (1) an a posteriori analysis, which consists in studying the events which have taken place at nuclear power plants and in seeking the deepseated causes so as to prevent their reoccurrence in future; (2) an a priori analysis, which consists in analysing a work situation and in detecting all its potential failure factors so as to prevent their resulting once again in dysfunctions of the facility. To illustrate these two types of analysis, two examples are given: first, a study of the telephonic communications between operators in one plant (in which the a posteriori and a priori analysis are developed) and, second, a study of stress in a plant (in which only the a priori analysis is used). (author). 1 tab

  2. Prognostic factors in Fournier gangrene.

    Science.gov (United States)

    Ruiz-Tovar, Jaime; Córdoba, Luis; Devesa, Jose Manuel

    2012-01-01

    Fournier gangrene is a necrotizing fasciitis, arising in the genital and perineal area. This entity is still associated with a high mortality rate despite improvements in antibiotic and surgical treatment. This is a retrospective study of all the patients diagnosed and surgically treated for Fournier gangrene at General University Hospital Ramon y Cajal between 1988 and 2008. Possible prognostic factors that could have any influence on the evolution of Fournier gangrene were analyzed. Seventy patients were analyzed, 62 males (88.6%) and 8 females (11.4%) with a mean age of 57.9 ± 13.5 years. Most frequent clinical manifestations were perineal pain (82.9%) and fever (60%). Physical examination revealed edema (91.4%), erythema (88.6%) and perineal skin necrosis (60%). All the patients underwent surgical debridement of necrotic tissue. In 54.3% reoperations were necessary for new surgical debridements. Medical complications rate was 27.1% and mortality one 22.9%. Ethylism, coexistence of neoplasms, presence of skin necrosis, myonecrosis, abdominal wall affection, number of debrided areas, reoperations, concentration of creatinine in serum>1.4 mg/dL, and hemoglobin <10 g/dL, and platelet count <150 × 10(9)/L in whole blood are associated with higher mortality rates. Identification of prognostic factors may help to determine high-risk patients in order to establish an optimal treatment, according to severity of the infection and general status. Copyright © 2012. Published by Elsevier B.V.

  3. Risk factors for diarrheal duration.

    Science.gov (United States)

    Mirza, N M; Caulfield, L E; Black, R E; Macharia, W M

    1997-11-01

    To identify child feeding behavior and household hygiene practices that are risk factors for prolonged diarrheal illness, a longitudinal community study was conducted over a 14-month period among 920 children aged 3-37 months who lived in an urban slum settlement in Nairobi, Kenya. Morbidity surveillance was done by home visits every third day in the absence of diarrhea and daily during diarrheal illness until termination of the episode. In-home observations were made to characterize maternal hygiene, cooking, and child feeding practices. Overall, 1,496 episodes of diarrhea were detected. The average diarrheal incidence was 3.5 episodes/child-year, and the incidence of diarrhea > 14 days was 3 episodes/100 child-years. Cox regression was used to examine the independent effects of covariates on time to recovery from a diarrheal episode. Adjusted behavioral factors that were observed to influence recovery from diarrhea included: uncovered water containers (rate ratio (RR) = 0.77, 95% confidence interval (CI) 0.64-0.94); giving no fluids (as opposed to oral rehydration solutions (ORS)/sugar salt solutions (SSS)) (RR = 1.42, 95% CI 1.14-1.77); and administration of diluted cow's milk during the first 3 days of an episode (RR = 1.23, 95% CI 1.00-1.52). These associations remained significant after adjusting for diarrheal severity. The authors recommend, among other measures, improvement of water storage and promotion of continued feeding with cereal-milk mix during diarrhea.

  4. Toward a Genotoxic Protection Factor

    International Nuclear Information System (INIS)

    Cesarini, J.P.; Demanneville, S.

    2000-01-01

    P53, a molecule normally expressed before mitosis, is considered as the 'guardian of the genome'. In the skin its level is normally very low (<3% of cells), detected by immunohistochemical methods. At least 50% of the keratinocytes express p53 protein, 24 h following a significant UV irradiation (2 SED). It is expected using sunscreens to reduce the expression of p53 in parallel with their ability to reduce the actinic erythema, the endpoint adopted to evaluate the Sun Protection Factor (SPF) of sunscreens. P53 detection on biopsies performed on the buttocks of human volunteers was used to evaluate the genotoxic protecting factor (GPF) of several sunscreens with either high UVB filtration or high UVA filtration, characterised by various SPF (COLIPA) from 10 to 40. The p53 count in parallel with sunburn cell count were the parameters studied. In general, the GPF of the sunscreens was found below the proprietary SPF. If a genotoxic effect is shown in an increased p53 expression, this effect is still observed at a dose lower than the dose inducing the faintest actinic erythema. (author)

  5. Light water reactor capacity factor investigation

    International Nuclear Information System (INIS)

    Meachum, T.R.; Monnie, D.I.; Whitacre, R.F. Jr.

    1985-01-01

    One of the internationally accepted measurements of an electrical generating station's productivity is the capacity factor. Comparison of the United States domestic nuclear facilities' cumulative capacity factors to the world shows that the US, while leading the western world in number of operating nuclear facilities, is near the bottom in the overall cumulative capacity factor. The purpose of this report is to identify the institutional and technological factors, which both adversely and favorably affect the domestic nuclear utilities' cumulative capacity factors

  6. Factors Responsible for Paddy Growers’ Diversification

    Directory of Open Access Journals (Sweden)

    Sathyapriya Eswaran

    2017-12-01

    Full Text Available In Tamil Nadu, a constituent state of India, the cultivable area under paddy had reduced over the period of time due to various factors. This study aims to enumerate the factors responsible for paddy growers’ diversification in the study area. Altogether 60 respondents were asked for the factors responsible for diversification. The major push factor responsible for diversification was inadequate labour availability & irrigation and availability of farm inputs was the major pull factor.

  7. Electroweak form factors of the Skyrmion

    International Nuclear Information System (INIS)

    Braaten, E.; Sze-Man Tse; Willcox, C.

    1986-01-01

    The electroweak form factors of baryons are studied in the semiclassical approximation to the Skyrme model. General expressions for the form factors are given for arbitrary choices of the Skyrme-model Lagrangian. They are applied to the original two-parameter Skyrme model to compute the electric, magnetic, and axial-vector form factors of the nucleon and the electromagnetic nucleon-Δ transition form factors. The dependence of the form factors on the momentum transfer is compared with phenomenological dipole parametrizations

  8. Factors Affecting Aerosol Radiative Forcing

    Science.gov (United States)

    Wang, J.; Lin, J.; Ni, R.

    2016-12-01

    Rapid industrial and economic growth has meant large amount of aerosols in the atmosphere with strong radiative forcing (RF) upon the climate system. Over parts of the globe, the negative forcing of aerosols has overcompensated for the positive forcing of greenhouse gases. Aerosol RF is determined by emissions and various chemical-transport-radiative processes in the atmosphere, a multi-factor problem whose individual contributors have not been well quantified. In this study, we analyze the major factors affecting RF of secondary inorganic aerosols (SIOAs, including sulfate, nitrate and ammonium), primary organic aerosol (POA), and black carbon (BC). We analyze the RFof aerosols produced by 11 major regions across the globe, including but not limited to East Asia, Southeast Asia, South Asia, North America, and Western Europe. Factors analyzed include population size, per capita gross domestic production (GDP), emission intensity (i.e., emissionsper unit GDP), chemical efficiency (i.e., mass per unit emissions) and radiative efficiency (i.e., RF per unit mass). We find that among the 11 regions, East Asia produces the largest emissions and aerosol RF, due to relatively high emission intensity and a tremendous population size.South Asia produce the second largest RF of SIOA and BC and the highest RF of POA, in part due to its highest chemical efficiency among all regions. Although Southeast Asia also has large emissions,its aerosol RF is alleviated by its lowest chemical efficiency.The chemical efficiency and radiative efficiency of BC produced by the Middle East-North Africa are the highest across the regions, whereas its RF is loweredbyasmall per capita GDP.Both North America and Western Europe have low emission intensity, compensating for the effects on RF of large population sizes and per capita GDP. There has been a momentum to transfer industries to Southeast Asia and South Asia, and such transition is expected to continue in the coming years. The resulting

  9. Menarquia y factores asociados Menarche and associated factors

    Directory of Open Access Journals (Sweden)

    Wendy Valdés Gómez

    2013-04-01

    Full Text Available Introducción: la menarquia es el indicador de maduración sexual más comúnmente utilizado, influida por factores genéticos y ambientales, y se asocia al riesgo de desarrollar enfermedades como la obesidad, el cáncer de mama, las enfermedades cardiovasculares, entre otras. Objetivos: caracterizar demográficamente las adolescentes en estudio; evaluarlas nutricionalmente utilizando el índice de masa corporal y la circunferencia de cintura, así como identificar la relación entre la menarquia, el color de la piel, el bajo peso al nacer, el exceso de peso corporal, la obesidad abdominal y la presencia de acantosis nigricans. Métodos: se realizó un estudio observacional, descriptivo transversal en la Secundaria Básica Urbana "José María Heredia", desde junio de 2010 a enero de 2011. La población estuvo constituida por 85 adolescentes, a las cuales se les preguntó acerca de la menarquia, se les realizaron las mediciones antropométricas, y se buscó la presencia de acantosis nigricans. Resultados: la edad media de las adolescentes fue 12,05 años, de las cuales el 63,5 % había experimentado la menarquia, y su edad media de presentación fue de 11,00±0,801 años. El 17,6 % presentó exceso corporal, el 34,1 % adiposidad abdominal y el 12,9 % acantosis nigricans, asociadas estadísticamente con la aparición de la menarquia. Conclusiones: la mayoría de las adolescentes que habían experimentado la menarquia eran maduradoras tempranas, y de color de piel blanca; mostraron un riesgo incrementado de desarrollar exceso de peso corporal, obesidad abdominal y signos clínicos de resistencia a la insulina. La aparición de la menarquia no estuvo influida por el bajo peso al nacer.Introduction: menarche is the most common sexual maturity indicator, influenced by genetic and environmental factors and associated to the risk of developing diseases such as obesity, breast cancer, cardiovascular diseases and others. Objectives: to characterize

  10. Factores determinantes en las OPI

    Directory of Open Access Journals (Sweden)

    Rodriguez, M.P.

    2008-01-01

    Full Text Available The effect of “underpricing” is closely related to the difference of the price set up in the IPO and the closing price of its first day of trading. This concept has been studied internationally for more than 3 decades and it is lately relevant to emerging countries, particularly in the stock markets in which double digit growth has been an important factor such as the Mexican Stock Market. Here we will find some theoretical studies as well as some behaviors in this matter regarding companies in their first public offer. This article does not pretend to be exhaustive but to bring relevance of several studies and theories, to relate variables in international context to the Mexican Stock Market. Further more, conclusions and follow-up actions in this investigation will aim to have a successful initial public offer.

  11. Kleptomania and Potential Exacerbating Factors

    Science.gov (United States)

    2011-01-01

    Kleptomania is an impulse control disorder that can cause significant impairment and serious consequences. Often, the condition is kept secret by the patient, and usually help is sought only when confronted by the legal consequences of the impulsive behaviors. Historically, kleptomania has been viewed from a psychodynamic perspective, and the mainstay of treatment has been psychotherapy. Recently, attempts to explain kleptomania within a neuropsychiatric paradigm have highlighted the possible links between mood disorders, addictive behaviors, and brain injury with kleptomania. These associations with kleptomania can be extrapolated to pharmacological strategies that can potentially help in treating kleptomania. A case of kleptomania, which was potentially exacerbated by multiple factors, will be reviewed. Treatment modalities used in this case, including the use of the Yale-Brown Obsessive Compulsive Scale as a surrogate marker to gauge response to treatment, will be discussed. PMID:22132369

  12. Genetic factors for breast carcinogenesis

    Directory of Open Access Journals (Sweden)

    Pedro Enrique Miguel-Soca

    2016-12-01

    Full Text Available Breast cancer is a multifactorial genenetic disease in which oncogenes derived from normal cellular genes intervene, which constitute positive signals of cellular proliferation and tumour suppressor genes and represent negative signals of cells multiplication and differentiation. Although these alterations which affect germinal cells produce inherited cancers, in most of the cases somatic cell genes are affected. To the susceptibility of cancer due to genes as BRCA1 and BCRA2, the effect of factors associated to environment, life style and toxic habits are added, these determine a complex interrelation genes-environment which imply an activation of oncogenes and inactivation of tumour suppressors. The objective of this review in to offer an updated view about the main genes implied in breast carcinogenesis. The topic is controversial y currently deeply investigated.

  13. Factorized combinations of Virasoro characters

    International Nuclear Information System (INIS)

    Bytsko, A.G.; Fring, A.

    2000-01-01

    We investigate linear combinations of characters for minimal Virasoro models which are representable as a product of several basic blocks. Our analysis is based on consideration of asymptotic behaviour of the characters in the quasi-classical limit. In particular, we introduce a notion of the secondary effective central charge. We find all possible cases for which factorization occurs on the base of the Gauss-Jacobi or the Watson identities. Exploiting these results, we establish various types of identities between different characters. In particular, we present several identities generalizing the Rogers-Ramanujan identities. Applications to quasi-particle representations, modular invariant partition functions, super-conformal theories and conformal models with boundaries are briefly discussed. (orig.)

  14. Transcription factors: Time to deliver.

    Science.gov (United States)

    Ulasov, Alexey V; Rosenkranz, Andrey A; Sobolev, Alexander S

    2018-01-10

    Transcription factors (TFs) are at the center of the broad regulatory network orchestrating gene expression programs that elicit different biological responses. For a long time, TFs have been considered as potent drug targets due to their implications in the pathogenesis of a variety of diseases. At the same time, TFs, located at convergence points of cellular regulatory pathways, are powerful tools providing opportunities both for cell type change and for managing the state of cells. This task formulation requires the TF modulation problem to come to the fore. We review several ways to manage TF activity (small molecules, transfection, nanocarriers, protein-based approaches), analyzing their limitations and the possibilities to overcome them. Delivery of TFs could revolutionize the biomedical field. Whether this forecast comes true will depend on the ability to develop convenient technologies for targeted delivery of TFs. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Human factors reliability Benchmark exercise

    International Nuclear Information System (INIS)

    Poucet, A.

    1989-06-01

    The Joint Research Centre of the European Commission has organized a Human Factors Reliability Benchmark Exercise (HF-RBE) with the aim of assessing the state of the art in human reliability modelling and assessment. Fifteen teams from eleven countries, representing industry, utilities, licensing organisations and research institutes, participated in the HF-RBE. The HF-RBE was organized around two study cases: (1) analysis of routine functional Test and Maintenance (T and M) procedures: with the aim of assessing the probability of test induced failures, the probability of failures to remain unrevealed and the potential to initiate transients because of errors performed in the test; (2) analysis of human actions during an operational transient: with the aim of assessing the probability that the operators will correctly diagnose the malfunctions and take proper corrective action. This report contains the final summary reports produced by the participants in the exercise

  16. Language deficits and genetic factors.

    Science.gov (United States)

    Gopnik, M

    1997-04-01

    Although most children acquire language effortlessly, there are some children who find learning language a difficult and arduous task. This group of subjects resembles a natural experiment and has the potential to provide us with insights into the nature of the biological basis of language. The data show that this disorder is associated with certain genetic factors that can lead to neurological abnormalities. Our studies of the linguistic details of language impairment in English, French, Greek and Japanese have led us to conclude that affected individuals cannot construct normal representations for complex words nor can they construct the rules which should operate on these representations. These data are inconsistent with any explanation in terms of auditory or articulatory processing. Therefore, we must conclude that a genetic disorder can impair the ability to build a normal grammar.

  17. Disability as a risk factor?

    DEFF Research Database (Denmark)

    Bøttcher, Louise; Dammeyer, Jesper

    2013-01-01

    and psychopathology. Both a congenital hearing impairment and cerebral palsy were found to be dominating risk factors for all types of psychopathology, but no relationship was identified between degree of disability and risk of psychopathology. The higher risk cannot be explained by biological impairments alone......Empirical research has established that children with disabilities are more likely to develop psychopathology than children without disabilities. But too little is known about the association between disability and psychopathology. The aim of this article is to discuss developmental...... psychopathological models that conceptualize the connection between childhood disability and psychopathology. Empirical studies of psychopathology among children with a congenital hearing impairment and children with cerebral palsy will be reviewed, representing in-depth examples of association between disability...

  18. Neurodevelopmental risk factors in schizophrenia

    Directory of Open Access Journals (Sweden)

    Lobato M.I.

    2001-01-01

    Full Text Available The authors review environmental and neurodevelopmental risk factors for schizophrenic disorders, with emphasis on minor physical anomalies, particularly craniofacial anomalies and dermatoglyphic variations. The high prevalence of these anomalies among schizophrenic subjects supports the neurodevelopmental theory of the etiology of schizophrenia, since they suggest either genetically or epigenetically controlled faulty embryonic development of structures of ectodermal origin like brain and skin. This may disturb neurodevelopment that in turn may cause these subjects to be at increased risk for the development of schizophrenia and related disorders. The precise confirmation of this theory, at least in some cases, will provide further understanding of these illnesses, allowing easy and inexpensive identification of subjects at risk and providing guidelines for the development of new pharmacological interventions for early treatment and even for primary prevention of the illness.

  19. Molecular Risk Factors for Schizophrenia.

    Science.gov (United States)

    Modai, Shira; Shomron, Noam

    2016-03-01

    Schizophrenia (SZ) is a complex and strongly heritable mental disorder, which is also associated with developmental-environmental triggers. As opposed to most diagnosable diseases (yet similar to other mental disorders), SZ diagnosis is commonly based on psychiatric evaluations. Recently, large-scale genetic and epigenetic approaches have been applied to SZ research with the goal of potentially improving diagnosis. Increased computational analyses and applied statistical algorithms may shed some light on the complex genetic and epigenetic pathways contributing to SZ pathogenesis. This review discusses the latest advances in molecular risk factors and diagnostics for SZ. Approaches such as these may lead to a more accurate definition of SZ and assist in creating extended and reliable clinical diagnoses with the potential for personalized treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. AGROECOLOGICAL FACTORS OF FOOD SECURITY

    Directory of Open Access Journals (Sweden)

    L. Moldavan

    2014-09-01

    Full Text Available An experience of development of forms of economy in developed countries is analysed. Ways of development of domestic agriculture are proposed. The paper proved that Ukraine needs a new model of agriculture that was based not on the dynamic growth market of export production, and the balanced development of multipurpose field, which meets the needs of the country in food and foreign exchange earnings, warned to the depletion of natural resources. The extent of devastating effects of industrial model of agriculture development, which is oriented on economic growth without social and environmental price of its growth is revealed. Retrospective analysis of entry in international practice like formal institutional status of an alternative model in which an economic function of a branch (production and income is balanced with ecological (conservation potential land and social (food security is realized. Basic principles of ecologically oriented agriculture as a factor in long-term food security are formulated.