On braid monodromy factorizations

International Nuclear Information System (INIS)

Kharlamov, V M; Kulikov, Vik S

2003-01-01

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 2 up to symplectic isotopy

Maternal Knowledge and Attitude toward Exclusive Breast Milk Feeding (BMF in the First 6 Months of Infant Life in Mashhad

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Bibi Leila Hoseini

2014-01-01

Full Text Available Introduction: Breast milk is a complete food for growing children until 6 months of age, and mothers, as the most important child health care, play a decisive role in their growth. So promoting  their attitude toward the benefits of breastfeeding ensures guarantee child health in the future. This study aimed to assess maternal knowledge and attitude of Mashhad toward exclusive BMF in the first 6 months of infant life.   Materials and Methods: This cross-sectional descriptive-analytic study was conducted on 126 mothers who referring to Mashhad health-care centers for monitoring their 6-24 month year old infants. They completed questionnaire. Participants were selected by cluster and simple random sampling. Data were analyzed by descriptive- analytic tests and using SPSS 11.5.   Results: Mean score of maternal attitude toward exclusive BMF was 14.32±5.28 (out of 28 and maternal knowledge score toward advantages of breast milk was 19.59±4.80 (out of 28. The incidence of exclusive BMF in the first 6 months of life study was 73.8%. Child growth was as follows: excellent growth (5.6% and good growth (42.1%. ANOVA showed a significant difference between parents' education and maternal attitude towards exclusive BMF; whatever higher education of parents, more positive maternal attitude towards exclusive BMF (P

Maternal Knowledge and Attitude toward Exclusive Breast Milk Feeding (BMF in the First 6 Months of Infant in Mashhad-Iran

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M Saeidi

2014-04-01

Full Text Available Introduction: Breast milk is a complete food for growing children until 6 months of age, and mothers, as the most important child health care, play a decisive role in their growth. So promoting  their attitude toward the benefits of breastfeeding ensures guarantee child health in the future. This study aimed to assess maternal knowledge and attitude of Mashhad toward exclusive BMF in the first 6 months of infant life.   Materials and Methods: This cross-sectional descriptive-analytic study was conducted on 126 mothers who referring to Mashhad health-care centers for monitoring their 6-24 month year old infants. They completed questionnaire. Participants were selected by cluster and simple random sampling. Data were analyzed by descriptive- analytic tests and using SPSS 11.5.   Results: Mean score of maternal attitude toward exclusive BMF was 14.32±5.28 (out of 28 and maternal knowledge score toward advantages of breast milk was 19.59±4.80 (out of 28. The incidence of exclusive BMF in the first 6 months of life study was 73.8%. Child growth was as follows: excellent growth (5.6% and good growth (42.1%. ANOVA showed a significant difference between parents' education and maternal attitude towards exclusive BMF; whatever higher education of parents, more positive maternal attitude towards exclusive BMF (P

The fate of radiocesium in freshwater communities - Why is biomagnification variable both within and between species?

International Nuclear Information System (INIS)

Rasmussen, J.B.; Chant, L.A.; Rowan, D.J.

1997-01-01

In the Ottawa River, levels of 137 Cs exhibit classic biomagnification with about a 4-fold increase with each trophic level. For a given trophic level, organisms with a benthivorous diet have about 2-fold higher 137 Cs levels than planktivorous organisms of the same trophic level. Lower Bass Lake exhibits a similar pattern of biomagnification, as does Great Slave Lake. 137 Cs concentrations in 18 species of fish from the three systems average about 3-fold those of their food, and always exceed the concentration of 137 Cs in their food. However, there are no significant differences in biomagnification within functional groups or between functional groups and systems. These results conclusively demonstrate food-chain biomagnification of 137 Cs. Within species variation in biomagnification follows three patterns: linear increase with age (4 species); higher biomagnification in mature fish than immature fish, increasing in a step-like pattern (3 species); no increase with age (1 species). These patterns can be explained by the ratio of assimilated consumption to growth and elimination: a linear increase in biomagnification occurs when the ratio of assimilated consumption to growth and elimination increases with age; a step-wise increase in biomagnification at maturity occurs when the ratio of assimilated consumption to growth and elimination increases at maturity; no increase in biomagnification with age occurs when the ratio of assimilated consumption to growth and elimination remains constant throughout the fish lifecycle. This explains why no consensus has been reached regarding 137 Cs biomagnification and fish age and points to the predominance of consumption rates in determining the biomagnification of 137 Cs by fish. Thus, to accurately predict 137 Cs concentrations in fish under steady-state or dynamic conditions, consumption rates need to be known. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

Methylmercury biomagnification in an Arctic pelagic food web.

Science.gov (United States)

Ruus, Anders; Øverjordet, Ida B; Braaten, Hans Fredrik V; Evenset, Anita; Christensen, Guttorm; Heimstad, Eldbjørg S; Gabrielsen, Geir W; Borgå, Katrine

2015-11-01

Mercury (Hg) is a toxic element that enters the biosphere from natural and anthropogenic sources, and emitted gaseous Hg enters the Arctic from lower latitudes by long-range transport. In aquatic systems, anoxic conditions favor the bacterial transformation of inorganic Hg to methylmercury (MeHg), which has a greater potential for bioaccumulation than inorganic Hg and is the most toxic form of Hg. The main objective of the present study was to quantify the biomagnification of MeHg in a marine pelagic food web, comprising species of zooplankton, fish, and seabirds, from the Kongsfjorden system (Svalbard, Norway), by use of trophic magnification factors. As expected, tissue concentrations of MeHg increased with increasing trophic level in the food web, though at greater rates than observed in several earlier studies, especially at lower latitudes. There was strong correlation between MeHg and total Hg concentrations through the food web as a whole. The concentration of MeHg in kittiwake decreased from May to October, contributing to seasonal differences in trophic magnification factors. The ecology and physiology of the species comprising the food web in question may have a large influence on the magnitude of the biomagnification. A significant linear relationship was also observed between concentrations of selenium and total Hg in birds but not in zooplankton, suggesting the importance of selenium in Hg detoxification for individuals with high Hg concentrations. © 2015 SETAC.

Distribution, bioaccumulation and trophic transfer of chlorinated polyfluoroalkyl ether sulfonic acids in the marine food web of Bohai, China.

Science.gov (United States)

Chen, Hong; Han, Jianbo; Cheng, Jiayi; Sun, Ruijun; Wang, Xiaomeng; Han, Gengchen; Yang, Wenchao; He, Xin

2018-06-04

Chlorinated polyfluoroalkyl ether sulfonic acids (Cl-PFESAs) caused great concerns recently as novel fluorinated alternatives. However, information on their bioconcentration, bioaccumulation and biomagnification in marine ecosystems is limited. In this study, 152 biological samples including invertebrates, fishes, seabirds and mammals collected from Bohai Sea of China were analyzed to investigate the residual level, spatial distribution, bioaccumulation and biomagnification of Cl-PFESAs. 6:2 Cl-PFESA was found in concentrations ranging from factors (BAFs) for 6:2 Cl-PFESA ranged from 2.23 to 4.21, implying the bioaccumulation of this compound. The trophic magnification factor (BMF) for 6:2 Cl-PFESA was determined to be 3.37 in the marine food web, indicating biomagnification potential along the marine food chain. Copyright © 2018 Elsevier Ltd. All rights reserved.

Trophic structure and mercury biomagnification in tropical fish assemblages, Iténez River, Bolivia.

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Marc Pouilly

Full Text Available We examined mercury concentrations in three fish assemblages to estimate biomagnification rates in the Iténez main river, affected by anthropogenic activities, and two unperturbed rivers from the Iténez basin, Bolivian Amazon. Rivers presented low to moderate water mercury concentrations (from 1.25 ng L(-1 to 2.96 ng L(-1 and natural differences in terms of sediment load. Mercury biomagnification rates were confronted to trophic structure depicted by carbon and nitrogen stable isotopes composition (δ(15N; δ(13C of primary trophic sources, invertebrates and fishes. Results showed a slight fish contamination in the Iténez River compared to the unperturbed rivers, with higher mercury concentrations in piscivore species (0.15 µg g(-1 vs. 0.11 µg g(-1 in the unperturbed rivers and a higher biomagnification rate. Trophic structure analysis showed that the higher biomagnification rate in the Iténez River could not be attributed to a longer food chain. Nevertheless, it revealed for the Iténez River a higher contribution of periphyton to the diet of the primary consumers fish species; and more negative δ(13C values for primary trophic sources, invertebrates and fishes that could indicate a higher contribution of methanotrophic bacteria. These two factors may enhance methylation and methyl mercury transfer in the food web and thus, alternatively or complementarily to the impact of the anthropogenic activities, may explain mercury differences observed in fishes from the Iténez River in comparison to the two other rivers.

Effects of climate change on bioaccumulation and biomagnification of polycyclic aromatic hydrocarbons in the planktonic food web of a subtropical shallow eutrophic lake in China.

Science.gov (United States)

Tao, Yuqiang; Xue, Bin; Lei, Guoliang; Liu, Fei; Wang, Zhen

2017-04-01

To date effects of climate change on bioaccumulation and biomagnification of chemical pollutants in planktonic food webs have rarely been studied. Recruitments of plankton have shifted earlier due to global warming. Global warming and precipitation patterns are projected to shift seasonally. Whether and how the shifts in plankton phenology induced by climate change will impact bioaccumulation and biomagnification of chemical pollutants, and how they will respond to climate change are largely unknown. Here, we combine data analysis of the past seven decades, high temporal resolution monitoring and model development to test this hypothesis with nine polycyclic aromatic hydrocarbons (PAHs) in the planktonic food web of a subtropical shallow eutrophic lake in China. We find biphasic correlations between both bioconcentration factors and bioaccumulation factors of the PAHs and the mean temperature, which depend on the recruitment temperatures of cyanobacteria, and copepods and cladocerans. The positive correlations between bioconcentration factors, bioaccumulation factors and the mean temperature will be observed less than approximately 13-18 days by 2050-2060 due to the shifts in plankton phenology. The PAHs and their bioaccumulation and biomagnification will respond seasonally and differently to climate change. Bioaccumulation of most of the PAHs will decrease with global warming, with higher decreasing rates appearing in winter and spring. Biomagnification of most of the PAHs from phytoplankton to zooplankton will increase with global warming, with higher increasing rates appearing in winter and spring. Our study provides novel insights into bioaccumulation and biomagnification of chemical pollutants in eutrophic waters under climate change scenarios. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Bio Bay Game: Three-Dimensional Learning of Biomagnification.

Science.gov (United States)

Jasti, Chandana; Lauren, Hillary; Wallon, Robert C; Hug, Barbara

2016-01-01

Pressing concerns about sustainability and the state of the environment amplify the need to teach students about the connections between ecosystem health, toxicology, and human health. Additionally, the Next Generation Science Standards call for three-dimensional science learning, which integrates disciplinary core ideas, scientific practices, and crosscutting concepts. The Bio Bay Game is a way to teach students about the biomagnification of toxicants across trophic levels while engaging them in three-dimensional learning. In the game, the class models the biomagnification of mercury in a simple aquatic food chain as they play the roles of anchovies, tuna, and humans. While playing, the class generates data, which they analyze after the game to graphically visualize the buildup of toxicants. Students also read and discuss two articles that draw connections to a real-world case. The activity ends with students applying their understanding to evaluate the game as a model of biomagnification. Throughout the activity, students practice modeling and data analysis and engage with the crosscutting concepts of patterns and cause and effect to develop an understanding of core ideas about the connections between humans and the environment.

Mercury accumulation in sediments and seabird feathers from the Antarctic Peninsula.

Science.gov (United States)

Calle, Paola; Alvarado, Omar; Monserrate, Lorena; Cevallos, Juan Manuel; Calle, Nastenka; Alava, Juan José

2015-02-28

In an effort to assess the impact of mercury in the Antarctic Peninsula, we conducted ecotoxicological research in this region during the summer of 2012 and 2013. The objectives were to assess: (a) mercury levels in sediment samples; (b) mercury accumulation in Antarctic seabird feathers: Catharacta lonnbergi (brown skua), Pygoscelis papua (gentoo penguin) and Pygoscelis antarctica (chinstrap penguin); and (c) biomagnification (BMF predator/prey) and biota sediment accumulation (BSAF skuas/sediment) factors. Mercury concentrations in sediment were relatively low. Mercury concentrations were significantly higher in brown skuas and gentoo penguins than in chinstrap penguins (2012), and significantly higher in brown skuas than in both penguins (2013). BMF indicated 2-7.5 times greater mercury levels in brown skuas than in penguins. BSAF values suggested an apparent temporal decrease of 18.2% of this ratio from 2012 to 2013. Long-range environmental transport is the likely route of entry of mercury into the Antarctic Peninsula. Copyright © 2014 Elsevier Ltd. All rights reserved.

Trophic structure and mercury distribution in a Gulf of St. Lawrence (Canada) food web using stable isotope analysis

International Nuclear Information System (INIS)

Lavoie, Raphael A.; Hebert, Craig E.; Rail, Jean-Francois; Braune, Birgit M.; Yumvihoze, Emmanuel; Hill, Laura G.; Lean, David R.S.

2010-01-01

Even at low concentrations in the environment, mercury has the potential to biomagnify in food chains and reaches levels of concern in apex predators. The aim of this study was to relate the transfer of total mercury (THg) and methylmercury (MeHg) in a Gulf of St. Lawrence food web to the trophic structure, from primary consumers to seabirds, using stable nitrogen (δ 15 N) and carbon (δ 13 C) isotope analysis and physical environmental parameters. The energy reaching upper trophic level species was principally derived from pelagic primary production, with particulate organic matter (POM) at the base of the food chain. We developed a biomagnification factor (BMF) taking into account the various prey items consumed by a given predator using stable isotope mixing models. This BMF provides a more realistic estimation than when using a single prey. Lipid content, body weight, trophic level and benthic connection explained 77.4 and 80.7% of the variation in THg and MeHg concentrations, respectively in this food web. When other values were held constant, relationships with lipid and benthic connection were negative whereas relationships with trophic level and body weight were positive. Total Hg and MeHg biomagnified in this food web with biomagnification power values (slope of the relationship with δ 15 N) of 0.170 and 0.235, respectively on wet weight and 0.134 and 0.201, respectively on dry weight. Values of biomagnification power were greater for pelagic and benthopelagic species compared to benthic species whereas the opposite trend was observed for levels at the base of the food chain. This suggests that Hg would be readily bioavailable to organisms at the base of the benthic food chain, but trophic transfer would be more efficient in each trophic level of pelagic and benthopelagic food chains.

Mercury accumulation in sediments and seabird feathers from the Antarctic Peninsula

International Nuclear Information System (INIS)

Calle, Paola; Alvarado, Omar; Monserrate, Lorena; Cevallos, Juan Manuel; Calle, Nastenka; Alava, Juan José

2015-01-01

Highlights: • We assessed mercury bioaccumulation in seabirds in the Antarctic Peninsula. • Levels of Hg were higher in gentoo penguins & brown skuas than chinstrap penguins. • Mercury BMF in the brown skua/penguins relationship was higher than 1. • Long-range environmental transport is the likely mercury route in Antarctic. - Abstract: In an effort to assess the impact of mercury in the Antarctic Peninsula, we conducted ecotoxicological research in this region during the summer of 2012 and 2013. The objectives were to assess: (a) mercury levels in sediment samples; (b) mercury accumulation in Antarctic seabird feathers: Catharacta lonnbergi (brown skua), Pygoscelis papua (gentoo penguin) and Pygoscelis antarctica (chinstrap penguin); and (c) biomagnification (BMF predator/prey) and biota sediment accumulation (BSAF skuas/sediment) factors. Mercury concentrations in sediment were relatively low. Mercury concentrations were significantly higher in brown skuas and gentoo penguins than in chinstrap penguins (2012), and significantly higher in brown skuas than in both penguins (2013). BMF indicated 2–7.5 times greater mercury levels in brown skuas than in penguins. BSAF values suggested an apparent temporal decrease of 18.2% of this ratio from 2012 to 2013. Long-range environmental transport is the likely route of entry of mercury into the Antarctic Peninsula

Study of Maternal Knowledge and Attitude toward Exclusive Breast Milk Feeding (BMF in the First 6 Months of Infant in Yazd-Iran

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Razieh Esfandtari

2014-06-01

Full Text Available Introduction: Breast milk is a complete food for growing children until 6 months of age, and mothers, as the most important child health care, play a decisive role in their growth. So promoting  their attitude toward the benefits of breastfeeding ensures guarantee child health in the future. This study aimed to assess maternal knowledge and attitude of Mashhad toward exclusive Breast Milk Feeding (BMFin the first 6 months of infant life.   Materials and Methods: This cross-sectional descriptive-analytic study was conducted on 190 mothers who referring to Yazd health-care centers for monitoring their 6-24 month year old infants. They completed questionnaire. Participants were selected by cluster and simple random sampling. Data were analyzed by descriptive- analytic tests and using SPSS 11.5.   Results: Mean score of maternal attitude toward exclusive BMF was 10.14±2.00 (out of 14 and maternal knowledge score toward advantages of breast milk was 10.12±2.015 (out of 14. The incidence of exclusive BMF in the first 6 months of life study was 72.9%. Child growth was as follows: excellent growth (24.5% and good growth (55.3%. ANOVA showed a significant difference between parents' education and maternal attitude and maternal knowledge towards exclusive BMF; whatever higher education of parents, more positive knowledge and attitude towards exclusive BMF (P

Biomagnification of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls in a highly contaminated freshwater food web from South China

International Nuclear Information System (INIS)

Wu Jiangping; Luo Xiaojun; Zhang Ying; Yu Mei; Chen Shejun; Mai Bixian; Yang Zhongyi

2009-01-01

To evaluate the biomagnification extent of polybrominated diphenyls ethers (PBDEs) and polychlorinated biphenyls (PCBs) in a highly contaminated freshwater food web from South China, trophic magnification factors (TMFs) for 18 PBDE congeners and 53 PCB congeners were calculated. The TMF values ranged 0.26-4.47 for PBDEs and 0.75-5.10 for PCBs. Forty-five of 53 PCBs and BDEs 47, 100 and 154 had TMFs greater than one, suggesting their biomagnification in the present food web. The TMFs for PBDEs were generally smaller than those for PCBs with the same degree of halogenation, indicating a lower biomagnification potential for PBDEs compared to PCBs. For PCBs, it followed a parabolic relationship between TMFs and log K OW (octanol-water partition coefficient). However, this relationship was not significant for PBDEs, possibly due to the more complex behaviors of PBDEs in the food web (e.g., metabolism), compared to that of PCBs. - Forty-five of 53 PCBs magnified in the freshwater food web, while only BDEs 47, 100 and 154 significantly magnified in the same food web

Biomagnification of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls in a highly contaminated freshwater food web from South China

Energy Technology Data Exchange (ETDEWEB)

Wu Jiangping [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Luo Xiaojun [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)], E-mail: luoxiaoj@gig.ac.cn; Zhang Ying; Yu Mei [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Chen Shejun; Mai Bixian [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Yang Zhongyi [School of Life Sciences, SunYat-Sen University, Guangzhou 510275 (China)

2009-03-15

To evaluate the biomagnification extent of polybrominated diphenyls ethers (PBDEs) and polychlorinated biphenyls (PCBs) in a highly contaminated freshwater food web from South China, trophic magnification factors (TMFs) for 18 PBDE congeners and 53 PCB congeners were calculated. The TMF values ranged 0.26-4.47 for PBDEs and 0.75-5.10 for PCBs. Forty-five of 53 PCBs and BDEs 47, 100 and 154 had TMFs greater than one, suggesting their biomagnification in the present food web. The TMFs for PBDEs were generally smaller than those for PCBs with the same degree of halogenation, indicating a lower biomagnification potential for PBDEs compared to PCBs. For PCBs, it followed a parabolic relationship between TMFs and log K{sub OW} (octanol-water partition coefficient). However, this relationship was not significant for PBDEs, possibly due to the more complex behaviors of PBDEs in the food web (e.g., metabolism), compared to that of PCBs. - Forty-five of 53 PCBs magnified in the freshwater food web, while only BDEs 47, 100 and 154 significantly magnified in the same food web.

KABAM Version 1.0 User's Guide and Technical Documentation - Appendix F -Description of Equations Used to Calculate the BCF, BAF, BMF, and BSAF Values

Science.gov (United States)

Describes equations for bioconcentration, bioaccumulation, biomagnification and biota-sediment accumulation factors used in KABAM V1.0. KABAM is a simulation model used to predict pesticide concentrations in aquatic regions for use in exposure assessments.

Methylmercury in fish from the South China Sea: Geographical distribution and biomagnification

International Nuclear Information System (INIS)

Zhu, Aijia; Zhang, Wei; Xu, Zhanzhou; Huang, Liangmin; Wang, Wen-Xiong

2013-01-01

Highlights: • A large-scale investigation of MeHg in 46 species of marine wild fish from South China Sea. • Log 10 MeHg concentration was significantly related to their length and wet weight. • Feeding habit and habitat were the primary factors influencing MeHg bioaccumulation. • Demersal fish were more likely to be contaminated with MeHg than the epipelagic and mesopelagic species. • Biomagnification of MeHg was site-specific. -- Abstract: We conducted a large-scale investigation of methylmercury (MeHg) in a total of 628 marine wild fish covering 46 different species collected from the South China Sea between 2008 and 2009. Biological and ecological characteristics such as size (length and wet weight), feeding habit, habitat, and stable isotope (δ 15 N) were examined to explain MeHg bioaccumulation in marine fish and their geographical distribution. MeHg levels in the muscle tissues of the 628 individuals ranged from 0.010 to 1.811 μg/g dry wt. Log 10 MeHg concentration was significantly related to their length and wet weight. Feeding habit and habitat were the primary factors influencing MeHg bioaccumulation. Demersal fish were more likely to be contaminated with MeHg than the epipelagic and mesopelagic varieties. Linear relationships were obtained between Log 10 (MeHg) and δ 15 N only for one location, indicating that biomagnification was site-specific. Results from this study suggest that dietary preference and trophic structure were the main factors affecting MeHg bioaccumulation in marine fish from the South China Sea

Biomagnification of persistent organic pollutants in a deep-sea, temperate food web.

Science.gov (United States)

Romero-Romero, Sonia; Herrero, Laura; Fernández, Mario; Gómara, Belén; Acuña, José Luis

2017-12-15

Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs) were measured in a temperate, deep-sea ecosystem, the Avilés submarine Canyon (AC; Cantabrian Sea, Southern Bay of Biscay). There was an increase of contaminant concentration with the trophic level of the organisms, as calculated from stable nitrogen isotope data (δ 15 N). Such biomagnification was only significant for the pelagic food web and its magnitude was highly dependent on the type of top predators included in the analysis. The trophic magnification factor (TMF) for PCB-153 in the pelagic food web (spanning four trophic levels) was 6.2 or 2.2, depending on whether homeotherm top predators (cetaceans and seabirds) were included or not in the analysis, respectively. Since body size is significantly correlated with δ 15 N, it can be used as a proxy to estimate trophic magnification, what can potentially lead to a simple and convenient method to calculate the TMF. In spite of their lower biomagnification, deep-sea fishes showed higher concentrations than their shallower counterparts, although those differences were not significant. In summary, the AC fauna exhibits contaminant levels comparable or lower than those reported in other systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Common support and integration of the BMS/BMF type MDT/RPC chambers of the muon spectrometer of the ATLAS experiment

International Nuclear Information System (INIS)

Barashkov, A.V.; Glonti, G.L.; Gongadze, A.L.; Gostkin, M.I.; Gus'kov, A.V.; Dedovich, D.V.; Demichev, M.A.; Zhemchugov, A.S.; Il'yushenko, E.N.; Kotov, S.A.; Korolevich, Ya.V.; Kruchonok, V.G.; Krumshtejn, Z.V.; Kuznetsov, N.K.; Lomidze, D.D.; Potrap, I.N.; Kharchenko, D.V.; Tskhadadze, Eh.G.; Chepurnov, V.F.; Shelkov, G.A.; Podkladkin, S.Yu.; Sekhniaidze, G.G.

2005-01-01

The common support system for muon BMS/BMF drift chambers with trigger RPC chambers for the muon spectrometer of the ATLAS experiment is described. The support systems are intended for the chambers integration into combined modules and for the subsequent installation in the experimental set-up. The technology of chambers integration is described. The sagging of the drift chambers was tested by tilting the modules at different angles. The measurements were performed by means of the RASNIK optical system. The normal operation of kinematic supports was confirmed. We also present the method of the sag regulation for the BMS/BMF chambers lying in the horizontal plane which provides the minimum difference between signal wire and detector tube body sags when the modules are later installed in their working positions

Stable isotope-guided analysis of biomagnification profiles of arsenic species in a tropical mangrove ecosystem

International Nuclear Information System (INIS)

Tu, Nguyen Phuc Cam; Agusa, Tetsuro; Ha, Nguyen Ngoc; Tuyen, Bui Cach; Tanabe, Shinsuke; Takeuchi, Ichiro

2011-01-01

We performed stable carbon and nitrogen-guided analyses of biomagnification profiles of arsenic (As) species, including total As, lipid-soluble As, eight water-soluble As compounds (arsenobetaine (AB), arsenocholine (AC), tetramethylarsonium ion (TETRA), trimethylarsine oxide (TMAO), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), arsenate (As[V]), and arsenite (As[III])), and non-extracted As in a tropical mangrove ecosystem in the Ba Ria Vung Tau, South Vietnam. Arsenobetaine was the predominant As species (65-96% of water-soluble As). Simple linear regression slopes of log-transformed concentrations of total As, As fractions or individual As compounds on stable nitrogen isotopic ratio (δ 15 N) values are regarded as indices of biomagnification. In this ecosystem, lipid-soluble As (slope, 0.130) and AB (slope, 0.108) were significantly biomagnified through the food web; total As and other water-soluble As compounds were not. To our knowledge, this is one of the first reports on biomagnification profiles of As compounds from a tropical mangrove ecosystem.

Biomagnification of bioassay derived 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents

Science.gov (United States)

Jones, P.D.; Ankley, G.T.; Best, D. A.; Crawford, R.; DeGalan, N.; Giesy, J.P.; Kubiak, T.J.; Ludwig, J. P.; Newsted, J.L.; Tillitt, D. E.; Verbrugge, D.A.

1993-01-01

In recent years contamination of the Great Lakes ecosystem with planar chlorinated hydrocarbons (PCHs) has attracted considerable concern due to their known reproductive and teratogenic effects. The H4IIE bioassay has been standardized as a means of measuring the biological potency of a PCH mixture as 2,3,7,8-tetrachloro-p-dibenzodioxin equivalents (TCDD-EQ). Using this bioassay we have investigated the biomagnification of TCDD-EQ in a semi-closed ecosystem. The biomagnification of TCDD-EQ is demonstrated and results indicate that the food chain is the major pathway for TCDD-EQ through this ecosystem. The H4IIE assay system is demonstrated to be a viable integrative measure of the total concentration of TCDD-EQ in different trophic levels.

Biomagnification of mercury through lake trout (Salvelinus namaycush) food webs of lakes with different physical, chemical and biological characteristics

Energy Technology Data Exchange (ETDEWEB)

Kidd, Karen A., E-mail: kiddk@unbsj.ca [Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, NB, Canada E2L 4L5 (Canada); Muir, Derek C.G., E-mail: derek.muir@ec.gc.ca [Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada L7R 4A6 (Canada); Evans, Marlene S., E-mail: marlene.evans@ec.gc.ca [Aquatic Contaminants Research Division, Environment Canada, Saskatoon, SK, Canada S7N 3H5 (Canada); Wang, Xioawa, E-mail: xiaowa.wang@ec.gc.ca [Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada L7R 4A6 (Canada); Whittle, Mike [Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada L7R 4A6 (Canada); Swanson, Heidi K., E-mail: heidikswanson@yahoo.ca [Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9 (Canada); Johnston, Tom, E-mail: tjohnston@laurentian.ca [Cooperative Freshwater Ecology Unit, Ontario Ministry of Natural Resources, and Biology Department, Laurentian University, Sudbury, ON, Canada P3E 2C6 (Canada); Guildford, Stephanie, E-mail: sguildfo@d.umn.edu [Department of Biology and Large Lakes Observatory, University of Minnesota Duluth, 2205 5th St., Duluth, MN, 55812 (United States)

2012-11-01

Mercury (Hg) biomagnification in aquatic ecosystems remains a concern because this pollutant is known to affect the health of fish-eating wildlife and humans, and the fish themselves. The 'rate' of mercury biomagnification is being assessed more frequently using stable nitrogen isotope ratios ({delta}{sup 15}N), a measure of relative trophic position of biota within a food web. Within food webs and across diverse systems, log-transformed Hg concentrations are significantly and positively related to {delta}{sup 15}N and the slopes of these models vary from one study to another for reasons that are not yet understood. Here we compared the rates of Hg biomagnification in 14 lake trout lakes from three provinces in Canada to understand whether any characteristics of the ecosystems explained this among-system variability. Several fish species, zooplankton and benthic invertebrates were collected from these lakes and analyzed for total Hg (fish only), methyl Hg (invertebrates) and stable isotopes ({delta}{sup 15}N; {delta}{sup 13}C to assess energy sources). Mercury biomagnification rates varied significantly across systems and were higher for food webs of larger (surface area), higher nutrient lakes. However, the slopes were not predictive of among-lake differences in Hg in the lake trout. Results indicate that among-system differences in the rates of Hg biomagnification seen in the literature may be due, in part, to differences in ecosystem characteristics although the mechanisms for this variability are not yet understood. -- Highlights: Black-Right-Pointing-Pointer Mercury biomagnifies through aquatic food webs to toxic levels in top predator fishes. Black-Right-Pointing-Pointer Among-system differences in mercury transfer through food webs occur but have not been explained. Black-Right-Pointing-Pointer Diverse lakes supporting lake trout were compared to understand the ecosystem processes that affect mercury biomagnification. Black

Minor cell-death defects but reduced tumor latency in mice lacking the BH3-only proteins Bad and Bmf.

Science.gov (United States)

Baumgartner, F; Woess, C; Pedit, V; Tzankov, A; Labi, V; Villunger, A

2013-01-31

Proapoptotic Bcl-2 family members of the Bcl-2 homology (BH)3-only subgroup are critical for the establishment and maintenance of tissue homeostasis and can mediate apoptotic cell death in response to developmental cues or exogenously induced forms of cell stress. On the basis of the biochemical experiments as well as genetic studies in mice, the BH3-only proteins Bad and Bmf have been implicated in different proapoptotic events such as those triggered by glucose- or trophic factor-deprivation, glucocorticoids, or histone deacetylase inhibition, as well as suppression of B-cell lymphomagenesis upon aberrant expression of c-Myc. To address possible redundancies in cell death regulation and tumor suppression, we generated compound mutant mice lacking both genes. Our studies revealed lack of redundancy in most paradigms of lymphocyte apoptosis tested in tissue culture. Only spontaneous cell death of thymocytes kept in low glucose or that of pre-B cells deprived of cytokines was significantly delayed when both genes were lacking. Of note, despite these minor apoptosis defects we observed compromised lymphocyte homeostasis in vivo that affected mainly the B-cell lineage. Long-term follow-up revealed significantly reduced latency to spontaneous tumor formation in aged mice when both genes were lacking. Together our study suggests that Bad and Bmf co-regulate lymphocyte homeostasis and limit spontaneous transformation by mechanisms that may not exclusively be linked to the induction of lymphocyte apoptosis.

Temporal variation and biomagnification of organohalogen compounds in finless porpoises (Neophocaena phocaenoides) from the South China Sea

International Nuclear Information System (INIS)

Ramu, Karri; Kajiwara, Natsuko; Lam, Paul K.S.; Jefferson, Thomas A.; Zhou Kaiya; Tanabe, Shinsuke

2006-01-01

Polybrominated diphenyl ethers (PBDEs) and organochlorine compounds (OCs) were determined in the blubber of male finless porpoises (Neophocaena phocaenoides) collected in 1990 and 2000/01 from the South China Sea. Among the organohalogen compounds analyzed, DDTs and PCBs were the predominant contaminants in the porpoises, ranging from 26,000 to 260,000 and 1400 to 28,000 ng/g lipid wt., respectively. PBDEs ranged from a minimum of 84 ng/g lipid wt., in 1990 to a maximum of 980 ng/g lipid wt., in 2001, showing a significant increase during the time period investigated. Congener profiles in finless porpoises did not shift to higher BDE congeners during these years, implying a continuous discharge of lower BDE commercial mixtures, such as PentaBDE. For OCs, HCHs concentrations decreased significantly, while others did not exhibit any significant temporal variation. Biomagnification factors (BMFs) were found to be highest for CHLs and lowest for HCB. PBDEs and PCBs had comparable BMFs, indicating a similar potential for biomagnification through the food web. - Levels and temporal variations of organohalogen contaminants in the South China Sea

Interpreting time trends and biomagnification of PCBs in the Baltic region using the equilibrium lipid partitioning approach

International Nuclear Information System (INIS)

Nfon, Erick; Cousins, Ian T.

2006-01-01

Multi-year monitoring data for PCBs in abiotic media and biota collected from the Baltic region were compiled into a database and analyzed using the equilibrium lipid partitioning (ELP) approach to study temporal trends as well as to investigate food web biomagnification. Statistically significant reductions in ELP concentrations between 1987 and 2001 were observed in guillemots, air, and some fish species and a general, but not always statistically significant decline in concentrations was observed throughout the Baltic ecosystem. Estimated clearance half-lives ranged from 2.7-10.7 years. The database contained concentrations for a range of different Baltic species, which comprise a well-known Baltic food web. It was possible to derive the trophic position of the species in this food web and relate them to ELP concentrations. A significant positive correlation between ELP concentrations and trophic position was obtained. Estimated food web magnification factors ranged between 1.9 and 5.1 for selected congeners. - The equilibrium lipid partitioning approach is applied to a large Baltic database of PCB concentrations in abiotic and biota media to investigate time trends and biomagnification

Basal mercury concentrations and biomagnification rates in freshwater and marine food webs: Effects on Arctic charr (Salvelinus alpinus) from eastern Canada

International Nuclear Information System (INIS)

Velden, S. van der; Dempson, J.B.; Evans, M.S.; Muir, D.C.G.; Power, M.

2013-01-01

Patterns of total Hg (THg) and methyl Hg (MeHg) biomagnification were investigated in six pairs of co-located lacustrine and marine food webs supporting a common predator, Arctic charr. Mercury biomagnification rates (the slope of log Hg concentration versus δ 15 N-inferred trophic level) did not differ significantly between the two feeding habitats for either THg or MeHg, but THg and MeHg concentrations at the base of the food web were higher in the lacustrine environment than in the marine environment. The proportion of THg as MeHg was related to trophic level, and the relationship was statistically similar in the lacustrine and marine habitats. The biomagnification rate of MeHg exceeded that of THg in both habitats. We conclude that the known difference in Hg concentration between anadromous and non-anadromous Arctic charr is driven by differential Hg concentrations at the base of the lacustrine and marine foodwebs, and not by differential biomagnification rates. - Highlights: ► Concentrations of total mercury ([THg]) and methylmercury ([MeHg]) were measured in 6 paired lacustrine and marine food webs. ► Biomagnification rates (slopes of [THg] or [MeHg] versus δ 15 N-inferred trophic level) were similar in the two habitat types. ► Mercury concentrations at the base of the food web were higher in lacustrine than in marine food webs. ► The percentage of methylated mercury increased with trophic level similarly in the two habitat types. ► The biomagnification rate of MeHg exceeded that of THg in both habitats

Biomagnification of persistent organic pollutants along a high-altitude aquatic food chain in the Tibetan Plateau: Processes and mechanisms.

Science.gov (United States)

Ren, Jiao; Wang, Xiaoping; Wang, Chuanfei; Gong, Ping; Wang, Xiruo; Yao, Tandong

2017-01-01

Biomagnification of some persistent organic pollutants (POPs) has been found in marine and freshwater food chains; however, due to the relatively short food chains in high-altitude alpine lakes, whether trophic transfer would result in the biomagnification of POPs is not clear. The transfer of various POPs, including organochlorine pesticides and polychlorinated biphenyls (PCBs), along the aquatic food chain in Nam Co Lake (4700 m), in the central Tibetan Plateau, was studied. The POPs levels in the water, sediment and biota [plankton, invertebrates and fish (Gymnocypris namensis)] of Nam Co were generally low, with concentrations comparable to those reported for the remote Arctic. The composition profiles of POPs in the fish were different from that in the water, but similar to their food. DDEs, DDDs, PCB 138, 153 and 180 displayed significant positive correlations with trophic levels, with trophic magnification factors (TMFs) ranged between 1.5 and 4.2, implying these chemicals can undergo final biomagnification along food chain. A fugacity-based dynamic bioaccumulation model was applied to the fish with localized parameters, by which the simulated concentrations were comparable to the measured data. Modeling results showed that most compounds underwent net gill loss and net gut uptake; only when the net result of the combined gut and gill fluxes would be positive, bioaccumulation could eventually occur. The net accumulation flux increased with fish age, which was caused by the continuous increase of gut uptake by aged fish. Due to the oligotrophic condition, efficient food absorption is likely the key factor that influences the gut POPs uptake. Long residence times with half-lives up to two decades were found for the higher chlorinated PCBs in Gymnocypris namensis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differences between Lipids Extracted from Five Species Are Not Sufficient To Explain Biomagnification of Nonpolar Organic Chemicals

DEFF Research Database (Denmark)

Jahnke, Annika; Holmbäck, Jan; Andersson, Rina Argelia

2015-01-01

headspace from spiked olive oil to determine their sorptive capacities. Lipids from seal blubber and pork bacon solely composed of triglycerides had capacities similar to that of olive oil; lipids from mussels, herring, and guillemot egg had quantifiable fractions of phospholipids and cholesterol and showed...... capacities reduced by factors of up to 2.3-fold. Generally, the sorptive capacities of the lipids were not elevated relative to the olive oil controls and are unlikely to explain a substantial part of biomagnification....

Black carbon inclusive multichemical modeling of PBDE and PCB biomagnification and -transformation in estuarine food webs.

Science.gov (United States)

Di Paolo, Carolina; Gandhi, Nilima; Bhavsar, Satyendra P; Van den Heuvel-Greve, Martine; Koelmans, Albert A

2010-10-01

Bioavailability and bioaccumulation of polybrominated diphenylethers (PBDEs) are affected by adsorption on black carbon (BC) and metabolism in biota, respectively. Recent studies have addressed these two processes separately, illustrating their importance in assessing contaminant dynamics. In order to properly examine biomagnification of polychlorinated biphenyls (PCBs) and PBDEs in an estuarine food-web, here we set up a black carbon inclusive multichemical model. A dual domain sorption model, which accounted for sorption to organic matter (OM) and black carbon (BC), was used to estimate aqueous phase concentrations from the measured chemical concentrations in suspended solids. We adapted a previously published multichemical model that tracks the movement of a parent compound and its metabolites in each organism and within its food web. First, the model was calibrated for seven PCB congeners assuming negligible metabolism. Subsequently, PBDE biomagnification was modeled, including biotransformation and bioformation of PBDE congeners, keeping the other model parameters the same. The integrated model was capable of predicting trophic magnification factors (TMF) within error limits. PBDE metabolic half-lives ranged 21-415 days and agreed to literature data. The results showed importance of including BC as an adsorbing phase, and biotransformation and bioformation of PBDEs for a proper assessment of their dynamics in aquatic systems.

Bioaccumulation and biomagnification of short and medium chain polychlorinated paraffins in different species of fish from Liaodong Bay, North China

OpenAIRE

Huang, Huiting; Gao, Lirong; Xia, Dan; Qiao, Lin

2017-01-01

Chlorinated paraffins (CPs) are highly complex technical mixtures, and the short chain chlorinated paraffins (SCCPs) are classed as persistent and have been included in the Stockholm Convention. However, there have been few studies of SCCPs and medium chain chlorinated paraffins (MCCPs) and their bioaccumulation and biomagnification in different species of fish. The present study investigated the levels, congener group profiles, bioaccumulation, and biomagnification of SCCPs and MCCPs in diff...

Biomagnification and debromination of polybrominated diphenyl ethers in a coastal ecosystem in Tokyo Bay

Energy Technology Data Exchange (ETDEWEB)

Mizukawa, Kaoruko; Yamada, Toshiko [Laboratory of Organic Geochemistry, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Matsuo, Hiroaki; Takeuchi, Ichiro [Department of Life Environment Conservation, Faculty of Agriculture, Ehime University, Tarumi 3-5-7, Matsuyama, Ehime 790-8566 (Japan); Tsuchiya, Kotaro [Faculty of Marine Science, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo 108-8477 (Japan); Takada, Hideshige, E-mail: shige@cc.tuat.ac.jp [Laboratory of Organic Geochemistry, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan)

2013-04-01

By field sampling and laboratory experiments we compared the mechanisms by which polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are biomagnified. We measured PBDEs and PCBs, together with stable carbon and nitrogen isotopes as an index of trophic level, in low-trophic-level organisms collected from a coastal area in Tokyo Bay. PBDEs were biomagnified to a lesser degree than PCBs. The more hydrophobic congeners of each were biomagnified more. However, the depletion of BDE congeners BDE99 and BDE153 from fish was suggested. To study congener-specific biotransformation of halogenated compounds, we conducted an in vitro experiment using hepatic microsomes of two species of fish and five BDE congeners (BDE47, 99, 100, 153, and 154) and five CB congeners with the same substitution positions as the PBDEs. BDE99 and 153 were partially debrominated, but BDE47 and 154 were not debrominated. This congener-specific debromination is consistent with the field results. Both in vitro and field results suggested selective debromination at the meta position. The CB congeners were not transformed in vitro. This result is also consistent with the field results, that PCBs were more biomagnified than PBDEs. We conclude that metabolizability is an important factor in the biomagnification of chemicals, but other factors must be responsible for the lower biomagnification of PBDEs in natural ecosystems. Highlights: ► PBDEs were less biomagnified than PCBs in low-trophic-level organisms in Tokyo Bay. ► Depletion of PBDE congeners BDE99 and BDE153 from fish was suggested. ► BDE99 and 153 were debrominated in in vitro experiment using hepatic microsomes of fish. ► BDE47, 100, and 154 as well as PCB congeners were not transformed in vitro. ► Both in vitro and field results suggested selective meta-protonation of PBDEs.

The distribution of 4-nonylphenol in marine organisms of North American Pacific Coast estuaries.

Science.gov (United States)

Diehl, Jennifer; Johnson, Sarah E; Xia, Kang; West, Amy; Tomanek, Lars

2012-04-01

One of the chemical breakdown products of nonylphenol ethoxylates, 4-nonylphenol (4-NP), accumulates in organisms and is of concern as an environmental pollutant due to its endocrine disrupting effects. We measured 4-NP levels in the seawater, sediment, and twelve organisms within the California estuary, Morro Bay, and examined biomagnification of 4-NP using stable isotope abundances (δ(15)N and δ(13)C) to quantify trophic position. 4-NP concentrations in organisms from Morro Bay included 25000±8600 ng g(-1) lw in liver of California sea lion, 14000±5600 ng g(-1) lw in liver of harbor porpoise, 138000±55000 ng g(-1) lw in liver of sea otters, 15700±3600 ng g(-1) lw in liver of seabirds, 36100±6100 ng g(-1) lw in arrow goby fish, 62800±28400 ng g(-1) lw in oysters, and 12700±1300 ng g(-1) lw in mussels. 4-NP levels generally showed a pattern of trophic dilution among organisms in Morro Bay, with exceptions of biomagnification observed between three trophic links: mussel to sea otter (BMF 10.9), oyster to sea otter (BMF 2.2), and arrow goby to staghorn sculpin (BMF 2.7). Our examination of other west coast estuaries of USA and Canada revealed that mean 4-NP concentrations in gobies and mussels from Morro Bay were significantly higher than those from a more urbanized estuary, San Francisco Bay (goby: 11100±3800 ng g(-1) lw) and from a remote estuary, Bamfield Inlet, Canada (goby: 9000±900 ng g(-1) lw, mussel: 6100±700 ng g(-1) lw). Relative to other estuaries worldwide, 4-NP levels in seawater (0.42±0.16 μg L(-1)) and sediment (53±14 ng g(-1) dw) of Morro Bay are low, but gobies and oysters have higher 4-NP levels than comparable fauna. Copyright © 2012 Elsevier Ltd. All rights reserved.

Bioaccumulation and biomagnification of mercury in African lakes: The importance of trophic status

Energy Technology Data Exchange (ETDEWEB)

Poste, Amanda E., E-mail: amanda.poste@niva.no [Norwegian Institute for Water Research, Gaustadalléen 21, 0349 Oslo (Norway); Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 (Canada); Muir, Derek C.G. [Aquatic Contaminants Research Division, Environment Canada, 867 Lakeshore Drive, Burlington, ON L7R 4A6 (Canada); Guildford, Stephanie J.; Hecky, Robert E. [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 (Canada); Large Lakes Observatory, University of Minnesota Duluth, 2205 East Fifth Street, Duluth, MN 55812 (United States)

2015-02-15

Despite the global prevalence of both mercury (Hg) contamination and anthropogenic eutrophication, relatively little is known about the behavior of Hg in eutrophic and hypereutrophic systems or the effects of lake trophic status on Hg uptake and trophodynamics. In the current study we explore Hg trophodynamics at 8 tropical East African study sites ranging from mesotrophic to hypereutrophic, in order to assess the influence of lake trophic status on Hg uptake and biomagnification. Comprehensive water, plankton and fish samples were collected for analysis of total mercury (THg) and stable carbon and nitrogen isotopic ratios. We found evidence that uptake of THg into phytoplankton tended to be lower in higher productivity systems. THg concentrations in fish were generally low, and THg trophic magnification factors (TMFs; representing the average increase in contaminant concentrations from one trophic level to the next) ranged from 1.9 to 5.6. Furthermore TMFs were significantly lower in hypereutrophic lakes than in meso- and eutrophic lakes, and were negatively related to chlorophyll a concentrations both across our study lakes, and across African lakes for which literature data were available. These observations suggest that THg concentrations were strongly influenced by trophic status, with year-round high phytoplankton and fish growth rates reducing the potential for high THg in fish in these productive tropical lakes. - Highlights: • We characterized Hg in water and biota from 8 East African study sites. • Hg concentrations in fish were low and should not pose a risk to human consumers. • Hg uptake and biomagnification rates were negatively related to trophic status. • Growth dilution in phytoplankton and consumer trophic levels led to low fish Hg.

Bioaccumulation and biomagnification of mercury in African lakes: The importance of trophic status

International Nuclear Information System (INIS)

Poste, Amanda E.; Muir, Derek C.G.; Guildford, Stephanie J.; Hecky, Robert E.

2015-01-01

Despite the global prevalence of both mercury (Hg) contamination and anthropogenic eutrophication, relatively little is known about the behavior of Hg in eutrophic and hypereutrophic systems or the effects of lake trophic status on Hg uptake and trophodynamics. In the current study we explore Hg trophodynamics at 8 tropical East African study sites ranging from mesotrophic to hypereutrophic, in order to assess the influence of lake trophic status on Hg uptake and biomagnification. Comprehensive water, plankton and fish samples were collected for analysis of total mercury (THg) and stable carbon and nitrogen isotopic ratios. We found evidence that uptake of THg into phytoplankton tended to be lower in higher productivity systems. THg concentrations in fish were generally low, and THg trophic magnification factors (TMFs; representing the average increase in contaminant concentrations from one trophic level to the next) ranged from 1.9 to 5.6. Furthermore TMFs were significantly lower in hypereutrophic lakes than in meso- and eutrophic lakes, and were negatively related to chlorophyll a concentrations both across our study lakes, and across African lakes for which literature data were available. These observations suggest that THg concentrations were strongly influenced by trophic status, with year-round high phytoplankton and fish growth rates reducing the potential for high THg in fish in these productive tropical lakes. - Highlights: • We characterized Hg in water and biota from 8 East African study sites. • Hg concentrations in fish were low and should not pose a risk to human consumers. • Hg uptake and biomagnification rates were negatively related to trophic status. • Growth dilution in phytoplankton and consumer trophic levels led to low fish Hg

Mercury biomagnification in a contaminated estuary food web: Effects of age and trophic position using stable isotope analyses

International Nuclear Information System (INIS)

Coelho, J.P.; Mieiro, C.L.; Pereira, E.; Duarte, A.C.; Pardal, M.A.

2013-01-01

Highlights: ► High trophic magnification potential of mercury in a temperate contaminated estuary. ► The use of age adjusted data provided better fitting to linear regression curves. ► Similar TMFs in other studies suggest stable magnification regardless of latitude. -- Abstract: The main aim of this study was to ascertain the biomagnification processes in a mercury-contaminated estuary, by clarifying the trophic web structure through stable isotope ratios. For this purpose, primary producers (seagrasses and macroalgae), invertebrates (detritivores and benthic predators) and fish were analysed for total and organic mercury and for stable carbon and nitrogen isotopic signatures. Trophic structure was accurately described by δ 15 N, while δ 13 C reflected the carbon source for each species. An increase of mercury levels was observed with trophic level, particularly for organic mercury. Results confirm mercury biomagnification to occur in this estuarine food web, especially in the organic form, both in absolute concentrations and fraction of total mercury load. Age can be considered an important variable in mercury biomagnification studies, and data adjustments to account for the different exposure periods may be necessary for a correct assessment of trophic magnification rates and ecological risk

Exploring the Hg pollution in global marginal seas by trophic biomagnification in demersal fishes

Science.gov (United States)

Tseng, C. M.; Hsieh, Y. C.; Chiang, C. Y.; Lamborg, C. H.; Chang, N. N.; Shiao, J. C.

2017-12-01

Limited knowledge still exists concerning the effects of size composition and trophic level (TL) on mercury levels in the demersal fishes associated with human activities in the marginal seas. In this study, we found evidence of strong control of TL on the Hg in fish and its biomagnification via food webs in the ECS. Total Hg in seven selected fish species, collected during the cruise OR1- 890 in July 2009, ranged from 2.6 and 256.2 ng g-1 (n=72). There were good linear relationships between Hg concentrations and fish body length (R2 = 0.79) and weight (R2 = 0.82), respectively, other than environmental variables (R2 = 0 0.03). It indicates that the Hg concentration in fish is mainly controlled by the growth mechanism of the fish itself through food chain transfer. In order to investigate how Hg levels in fish through trophic magnification associated with environmental changes, we hence developed the empirical method to calculate Hg accumulation rate (MAR) via the relationship of Hg concentration with the fish age for each fish species. The results further showed a significantly positive correlation of MAR with trophic levels, which relationship is Ln MAR =6.1 TL-15.8 (R2 = 0.89) in the ECS shelf. The magnitude of the slope (δMAR/δTL) as a biomagnification index of demersal fish shall provide the feasibility to compare Hg pollution situation among different marine ecosystems. Globally, the biomagnification indicator in the demersal fishes of the ECS is much greater than those in other marginal seas, suggesting high regional Hg pollution impacts from Mainland China.

Mercury biomagnification and the trophic structure of the ichthyofauna from a remote lake in the Brazilian Amazon

Energy Technology Data Exchange (ETDEWEB)

Azevedo-Silva, Claudio Eduardo, E-mail: ceass@biof.ufrj.br [Laboratório de Radioisótopos Eduardo Penna, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho s/n, bloco G, Sala 60, Subsolo, Ilha do Fundão, Rio de Janeiro, RJ (Brazil); Almeida, Ronaldo [Instituto Natureza e Cultura, Universidade Federal do Amazonas, Rua 1 de Maio. Colegiado de Ciências Agrárias, Benjamin Constant, Colônia, AM (Brazil); Carvalho, Dario P. [Laboratório de Radioisótopos Eduardo Penna, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho s/n, bloco G, Sala 60, Subsolo, Ilha do Fundão, Rio de Janeiro, RJ (Brazil); Ometto, Jean P.H.B. [Instituto Nacional de Pesquisas Espaciais, Centro de Ciências do Sistema Terrestre, Avenida dos Astronautas, 1758, Jardim da Granja, São José dos Campos, SP (Brazil); Camargo, Plínio B. de [Laboratório de Ecologia Isotópica, Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Avenida Centenário, 303, São Dimas, Piracicaba, SP (Brazil); and others

2016-11-15

The present study assesses mercury biomagnification and the trophic structure of the ichthyofauna from the Puruzinho Lake, Brazilian Amazon. In addition to mercury determination, the investigation comprised the calculation of Trophic Magnification Factor (TMF) and Trophic Magnification Slope (TMS), through the measurements of stable isotopes of carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) in fish samples. These assessments were executed in two different scenarios, i.e., considering (1) all fish species or (2) only the resident fish (excluding the migratory species). Bottom litter, superficial sediment and seston were the sources used for generating the trophic position (TP) data used in the calculation of the TMF. Samples from 84 fish were analysed, comprising 13 species, which were categorized into four trophic guilds: iliophagous, planktivorous, omnivorous and piscivorous fish. The δ{sup 13}C values pointed to the separation of the ichthyofauna into two groups. One group comprised iliophagous and planktivorous species, which are linked to the food chains of phytoplankton and detritus. The other group was composed by omnivorous and piscivorous fish, which are associated to the trophic webs of phytoplankton, bottom litter, detritus, periphyton, as well as to food chains of igapó (blackwater-flooded Amazonian forests). The TP values suggest that the ichthyofauna from the Puruzinho Lake is part of a short food web, with three well-characterized trophic levels. Mercury concentrations and δ{sup 13}C values point to multiple sources for Hg input and transfer. The similarity in Hg levels and TP values between piscivorous and planktivorous fish suggests a comparable efficiency for the transfer of this metal through pelagic and littoral food chains. Regarding the two abovementioned scenarios, i.e., considering (1) the entire ichthyofauna and (2) only the resident species, the TMF values were 5.25 and 4.49, as well as the TMS values were 0.21 and 0.19, respectively

Mercury biomagnification and the trophic structure of the ichthyofauna from a remote lake in the Brazilian Amazon

International Nuclear Information System (INIS)

Azevedo-Silva, Claudio Eduardo; Almeida, Ronaldo; Carvalho, Dario P.; Ometto, Jean P.H.B.; Camargo, Plínio B. de

2016-01-01

The present study assesses mercury biomagnification and the trophic structure of the ichthyofauna from the Puruzinho Lake, Brazilian Amazon. In addition to mercury determination, the investigation comprised the calculation of Trophic Magnification Factor (TMF) and Trophic Magnification Slope (TMS), through the measurements of stable isotopes of carbon (δ 13 C) and nitrogen (δ 15 N) in fish samples. These assessments were executed in two different scenarios, i.e., considering (1) all fish species or (2) only the resident fish (excluding the migratory species). Bottom litter, superficial sediment and seston were the sources used for generating the trophic position (TP) data used in the calculation of the TMF. Samples from 84 fish were analysed, comprising 13 species, which were categorized into four trophic guilds: iliophagous, planktivorous, omnivorous and piscivorous fish. The δ 13 C values pointed to the separation of the ichthyofauna into two groups. One group comprised iliophagous and planktivorous species, which are linked to the food chains of phytoplankton and detritus. The other group was composed by omnivorous and piscivorous fish, which are associated to the trophic webs of phytoplankton, bottom litter, detritus, periphyton, as well as to food chains of igapó (blackwater-flooded Amazonian forests). The TP values suggest that the ichthyofauna from the Puruzinho Lake is part of a short food web, with three well-characterized trophic levels. Mercury concentrations and δ 13 C values point to multiple sources for Hg input and transfer. The similarity in Hg levels and TP values between piscivorous and planktivorous fish suggests a comparable efficiency for the transfer of this metal through pelagic and littoral food chains. Regarding the two abovementioned scenarios, i.e., considering (1) the entire ichthyofauna and (2) only the resident species, the TMF values were 5.25 and 4.49, as well as the TMS values were 0.21 and 0.19, respectively. These findings

Methylmercury in fish from the South China Sea: geographical distribution and biomagnification.

Science.gov (United States)

Zhu, Aijia; Zhang, Wei; Xu, Zhanzhou; Huang, Liangmin; Wang, Wen-Xiong

2013-12-15

We conducted a large-scale investigation of methylmercury (MeHg) in a total of 628 marine wild fish covering 46 different species collected from the South China Sea between 2008 and 2009. Biological and ecological characteristics such as size (length and wet weight), feeding habit, habitat, and stable isotope (δ(15)N) were examined to explain MeHg bioaccumulation in marine fish and their geographical distribution. MeHg levels in the muscle tissues of the 628 individuals ranged from 0.010 to 1.811 μg/g dry wt. Log10MeHg concentration was significantly related to their length and wet weight. Feeding habit and habitat were the primary factors influencing MeHg bioaccumulation. Demersal fish were more likely to be contaminated with MeHg than the epipelagic and mesopelagic varieties. Linear relationships were obtained between Log10(MeHg) and δ(15)N only for one location, indicating that biomagnification was site-specific. Results from this study suggest that dietary preference and trophic structure were the main factors affecting MeHg bioaccumulation in marine fish from the South China Sea. Copyright © 2013 Elsevier Ltd. All rights reserved.

Seasonal variation in mercury and food web biomagnification in Lake Ontario, Canada

International Nuclear Information System (INIS)

Zhang Liang; Campbell, Linda M.; Johnson, Timothy B.

2012-01-01

Seasonal variation in mercury (Hg) concentrations and food web structure was assessed for eastern Lake Ontario. Hg concentrations, measured in 6 species of invertebrates and 8 species of fishes, tended to be highest in the spring and lowest in the summer for most biota. Yellow perch (Perca flavescens) exhibited significant ontogenetic shifts in diet and Hg, although such patterns were not evident for other species. Food web structure, as indicated by stable isotope values (δ 15 N, δ 13 C) was not static. Log-transformed Hg data were strongly and consistently correlated with δ 15 N values for the whole food web in each of the three seasons (slopes, 0.17–0.24) and across the entire year (slope, 0.2). While significantly different between seasons, the regression slope values are still consistent with published global Hg biomagnification rates. Our results indicate that the assessment of Hg trends in Great Lakes must take into account seasonal patterns and time of sampling. - Graphical abstract: Total mercury concentrations and trophic level (δ 15 N) regressions for organisms from the littoral Lake Ontario food web of Waupoos in 2009. Filled circles represent invertebrates while open circles represent fish. Dashed lines represents the regression between δ 15 N and THg of “whole” food web (log-Hg-δ 15 N regression equations in the upper left hand corner in each plot), and solid lines represents the regression between δ 15 N and THg of “fish-only” food web (log-Hg-δ 15 N regression equations in the lower right hand corner of each plot). Note that the y-axis is untransformed Hg concentrations plotted along a logarithmic scale, while the equations are based on log-transformed Hg values. Highlights: ► Most fish in littoral Lake Ontario had higher Hg concentrations in spring and lower Hg in summer. ► Log Hg consistently biomagnified throughout the food web in each season and for the year. ► Biomagnification rates (e.g., log Hg-δ 15 N slopes) vary

Mercury biomagnification and the trophic structure of the ichthyofauna from a remote lake in the Brazilian Amazon.

Science.gov (United States)

Azevedo-Silva, Claudio Eduardo; Almeida, Ronaldo; Carvalho, Dario P; Ometto, Jean P H B; de Camargo, Plínio B; Dorneles, Paulo R; Azeredo, Antonio; Bastos, Wanderley R; Malm, Olaf; Torres, João P M

2016-11-01

The present study assesses mercury biomagnification and the trophic structure of the ichthyofauna from the Puruzinho Lake, Brazilian Amazon. In addition to mercury determination, the investigation comprised the calculation of Trophic Magnification Factor (TMF) and Trophic Magnification Slope (TMS), through the measurements of stable isotopes of carbon (δ 13 C) and nitrogen (δ 15 N) in fish samples. These assessments were executed in two different scenarios, i.e., considering (1) all fish species or (2) only the resident fish (excluding the migratory species). Bottom litter, superficial sediment and seston were the sources used for generating the trophic position (TP) data used in the calculation of the TMF. Samples from 84 fish were analysed, comprising 13 species, which were categorized into four trophic guilds: iliophagous, planktivorous, omnivorous and piscivorous fish. The δ 13 C values pointed to the separation of the ichthyofauna into two groups. One group comprised iliophagous and planktivorous species, which are linked to the food chains of phytoplankton and detritus. The other group was composed by omnivorous and piscivorous fish, which are associated to the trophic webs of phytoplankton, bottom litter, detritus, periphyton, as well as to food chains of igapó (blackwater-flooded Amazonian forests). The TP values suggest that the ichthyofauna from the Puruzinho Lake is part of a short food web, with three well-characterized trophic levels. Mercury concentrations and δ 13 C values point to multiple sources for Hg input and transfer. The similarity in Hg levels and TP values between piscivorous and planktivorous fish suggests a comparable efficiency for the transfer of this metal through pelagic and littoral food chains. Regarding the two abovementioned scenarios, i.e., considering (1) the entire ichthyofauna and (2) only the resident species, the TMF values were 5.25 and 4.49, as well as the TMS values were 0.21 and 0.19, respectively. These findings

Dechlorination of the dietary nona-chlorinated toxaphene congeners 62 and 50 into the octa-chlorinated toxaphene congeners 44 and 40 in zebrafish (Danio rerio) and Atlantic salmon (Salmo salar)

Energy Technology Data Exchange (ETDEWEB)

Berntssen, M.H.G., E-mail: marc.berntssen@nifes.no [National Institute of Nutrition and Seafood Research (NIFES), Postbox 2029 Nordnes, 5817 Bergen (Norway); Lundebye, A.-K.; Hop-Johannessen, L.; Lock, E.-J. [National Institute of Nutrition and Seafood Research (NIFES), Postbox 2029 Nordnes, 5817 Bergen (Norway)

2012-05-15

Graphical abstract: - Abstract: The relative feed-to-fish accumulation and possible biotransformation of the nona-chlorinated toxaphene congeners currently included in EU-legislation (CHB-50 and -62) and the octa-chlorinated congeners recommended by the European Food Safety Authority to be included in future surveillance of fish samples (CHB-40, 41, and 44) were investigated in the present study. Model fish Danio rerio were fed either (a) diets spiked with a combination as well as the pure individual toxaphene congeners CHB-50 or 62 or (b) diets spiked with the combination of CHB N-Ary-Summation 50 + 62 and/or CHB N-Ary-Summation 40 + 41 + 44. In addition, seawater adapted Atlantic salmon smolts were fed technical toxaphene enriched feeds for 62 days. Zebrafish fed a diet containing CHB-50 and CHB-62 accumulated newly formed CHB-40 and 41 and CHB-44, respectively. The biomagnifications factors (BMF) of the toxaphene congeners in Atlantic salmon muscle from the feeds spiked with technical toxaphene were significantly correlated with their relative lipophilicity (expressed as log K{sub ow}). An exception was CHB-44 which had a higher BMF than could be expected from its specific log K{sub ow}, reflecting that CHB-44 is a metabolite formed under dietary exposure to CHB-62. This paper reports the in vivo dechlorination of nona-chlorinated toxaphene congeners into octa-chlorinated congeners in feeding trials with a model fish (zebrafish) and an oily food fish (Atlantic salmon).

Dechlorination of the dietary nona-chlorinated toxaphene congeners 62 and 50 into the octa-chlorinated toxaphene congeners 44 and 40 in zebrafish (Danio rerio) and Atlantic salmon (Salmo salar)

International Nuclear Information System (INIS)

Berntssen, M.H.G.; Lundebye, A.-K.; Hop-Johannessen, L.; Lock, E.-J.

2012-01-01

Graphical abstract: - Abstract: The relative feed-to-fish accumulation and possible biotransformation of the nona-chlorinated toxaphene congeners currently included in EU-legislation (CHB-50 and -62) and the octa-chlorinated congeners recommended by the European Food Safety Authority to be included in future surveillance of fish samples (CHB-40, 41, and 44) were investigated in the present study. Model fish Danio rerio were fed either (a) diets spiked with a combination as well as the pure individual toxaphene congeners CHB-50 or 62 or (b) diets spiked with the combination of CHB ∑50 + 62 and/or CHB ∑40 + 41 + 44. In addition, seawater adapted Atlantic salmon smolts were fed technical toxaphene enriched feeds for 62 days. Zebrafish fed a diet containing CHB-50 and CHB-62 accumulated newly formed CHB-40 and 41 and CHB-44, respectively. The biomagnifications factors (BMF) of the toxaphene congeners in Atlantic salmon muscle from the feeds spiked with technical toxaphene were significantly correlated with their relative lipophilicity (expressed as log K ow ). An exception was CHB-44 which had a higher BMF than could be expected from its specific log K ow , reflecting that CHB-44 is a metabolite formed under dietary exposure to CHB-62. This paper reports the in vivo dechlorination of nona-chlorinated toxaphene congeners into octa-chlorinated congeners in feeding trials with a model fish (zebrafish) and an oily food fish (Atlantic salmon).

Short description of BMS/BMF MDT chamber production for the muon spectrometer of the ATLAS experiment

International Nuclear Information System (INIS)

Barashkov, A.V.; Glonti, G.L.; Gongadze, A.L.; Gongadze, I.B.; Gostkin, M.I.; Gus'kov, A.V.; Dedovich, D.V.; Demichev, M.A.; Evtukhovich, P.G.; Elagin, A.L.; Zhemchugov, A.S.; Il'yushenko, E.N.; Kotov, S.A.; Kotova, T.I.; Korolevich, Ya.V.; Kruchonok, V.G.; Krumshtejn, Z.V.; Kuznetsov, N.K.; Lomidze, D.D.; Nikolaev, K.V.; Potrap, I.N.; Rudenko, T.O.; Kharchenko, D.V.; Tskhadadze, Eh.G.; Chepurnov, V.F.; Shelkov, G.A.; Shiyakova, M.M.; Shcherbakov, A.A.; Podkladkin, S.Yu.

2005-01-01

The method of assembly of the MDT chambers for the muon spectrometer of the ATLAS experiment is described. During 2000-2004 ∼ 25000 drift tubes were produced at the DLNP, JINR. The tubes were assembled into 84 muon chambers of BMS/BMF type, one of the six main types for the barrel part of the ATLAS muon spectrometer. Particle momenta must be measured in the ATLAS spectrometer with very high precision (2% at 100 GeV/c and 10% at 1000 GeV/c), which required to produce the coordinate detectors with very high (∼80 μm) precision. We describe the method of assembly of large-scale 5-10 m 2 muon chambers with the signal wire mean deviation from the nominal position less than 20 μm

Routes of plutonium uptake and their relation to biomagnification in starfish

International Nuclear Information System (INIS)

Guary, J.-C.; Fowler, S.W.; Beasley, T.M.

1982-01-01

The distribution of 239+240 Pu and 238 Pu in environmental samples of starfish tissues is identical to the tissue distribution observed in experimental animals following uptake of plutonium directly from water. Plutonium in sea water has a strong affinity for the mucus-rich epidermal layer of starfish which contributes substantially to the relatively high levels of this transuranium nuclide measured in these invertebrates. Transfer of plutonium to starfish via food also occurs; however, the resultant tissue distribution is not consistent with that found in the natural environment where plutonium is available from both contaminated food and water. These data suggest that food chain biomagnification of plutonium by starfish does not occur in nature as has been previously hypothesized. (author)

Bioaccumulation and biomagnification of classical flame retardants, related halogenated natural compounds and alternative flame retardants in three delphinids from Southern European waters

International Nuclear Information System (INIS)

Barón, E.; Giménez, J.; Verborgh, P.; Gauffier, P.; De Stephanis, R.; Eljarrat, E.; 2O Building, Scientific and Technological Park of the University of Girona, Emili Grahit 101, 17003 Girona (Spain))" data-affiliation=" (Institute of Environmental Assessment and Water Research Studies (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, 08034 Barcelona (Spain); Catalan Institute for Water Research (ICRA), H2O Building, Scientific and Technological Park of the University of Girona, Emili Grahit 101, 17003 Girona (Spain))" >Barceló, D.

2015-01-01

Occurrence and behaviour of classical (PBDEs) and alternative (HNs, HBB, PBEB, DBDPE and HBCD) flame retardants, together with naturally produced MeO-PBDEs, were studied in short-beaked common dolphin (Delphinus delphis), bottlenose dolphin (Tursiops truncatus) and long-finned pilot whale (Globicephala melas) in two sampling locations from Southern European waters. PBDEs, Dec 602, Dec 603, DP, α-HBCD and two MeO-PBDEs were detected in all three species. ∑PBDEs were between 17 and 2680 ng/g lw; ∑HNs were between 1.1 and 59 ng/g lw; α-HBCD levels ranged between 3.2 and 641 ng/g lw; ∑MeO-PBDEs were between 34 and 1966 ng/g lw. Bottlenose dolphins were the most contaminated species and some individuals could present health risk for endocrine disruption since levels found were above the reported threshold (1500 ng/g lw). Stable isotope analysis was used to evaluate the biomagnification capacity of these compounds. PBDEs, MeO-PBDEs and Dec 602 showed a significant positive correlation with trophic position. - Highlights: • Several FRs were detected in three dolphin species from Southern European waters. • Concentrations of classical FRs were higher than concentrations of alternative FRs. • MeO-PBDE concentrations were generally similar to PBDE concentrations. • Evidence of biomagnification capacity of some FRs was observed. • Some individuals were above the threshold level associated to endocrine disruption. - Bioaccumulation and biomagnification of halogenated compounds in dolphins

Modelos de previsão de preços aplicados aos contratos futuros de boi gordo na BM&F Models of price forecasting applied to futures contracts of live cattle at the Brazilian Futures Market - BM&F

Directory of Open Access Journals (Sweden)

Aureliano Angel Bressan

2002-01-01

Full Text Available This paper studies the applicability of time series models as a decision tool of buy and sell orders of live cattle futures contracts in the Brazilian Futures Market (BM&F, on dates close to expiration. The models considered are: ARIMA, Neural Networks and Dynamic Linear Models - DLM (this in the classic and bayesian approach. Weekly data, of the spot and futures markets, from 1996 to 1999, are used to calculate the forecasts. The main purpose is to calculate the returns, in buy/sell orders of live cattle futures between 1998 and 1999, in order to show the potentials or limitations of each model. The results show positive returns in almost all contracts analyzed, indicating the potential of the models as a decision tool in operating with futures contracts close to expiration date, with distinction on the performance of the Classic DLM and ARIMA models, although some differences in forecasting accuracy.

Fracked ecology: Response of aquatic trophic structure and mercury biomagnification dynamics in the Marcellus Shale Formation.

Science.gov (United States)

Grant, Christopher James; Lutz, Allison K; Kulig, Aaron D; Stanton, Mitchell R

2016-12-01

Unconventional natural gas development and hydraulic fracturing practices (fracking) are increasing worldwide due to global energy demands. Research has only recently begun to assess fracking impacts to surrounding environments, and very little research is aimed at determining effects on aquatic biodiversity and contaminant biomagnification. Twenty-seven remotely-located streams in Pennsylvania's Marcellus Shale basin were sampled during June and July of 2012 and 2013. At each stream, stream physiochemical properties, trophic biodiversity, and structure and mercury levels were assessed. We used δ15N, δ13C, and methyl mercury to determine whether changes in methyl mercury biomagnification were related to the fracking occurring within the streams' watersheds. While we observed no difference in rates of biomagnificaion related to within-watershed fracking activities, we did observe elevated methyl mercury concentrations that were influenced by decreased stream pH, elevated dissolved stream water Hg values, decreased macroinvertebrate Index for Biotic Integrity scores, and lower Ephemeroptera, Plecoptera, and Trichoptera macroinvertebrate richness at stream sites where fracking had occurred within their watershed. We documented the loss of scrapers from streams with the highest well densities, and no fish or no fish diversity at streams with documented frackwater fluid spills. Our results suggest fracking has the potential to alter aquatic biodiversity and methyl mercury concentrations at the base of food webs.

Earthworm biomass as additional information for risk assessment of heavy metal biomagnification: a case study for dredged sediment-derived soils and polluted floodplain soils

International Nuclear Information System (INIS)

Vandecasteele, Bart; Samyn, Jurgen; Quataert, Paul; Muys, Bart; Tack, Filip M.G.

2004-01-01

The important role of earthworms in the biomagnification of heavy metals in terrestrial ecosystems is widely recognised. Differences in earthworm biomass between sites is mostly not accounted for in ecological risk assessment. These differences may be large depending on soil properties and pollution status. A survey of earthworm biomass and colonisation rate was carried out on dredged sediment-derived soils (DSDS). Results were compared with observations for the surrounding alluvial plains. Mainly grain size distribution and time since disposal determined earthworm biomass on DSDS, while soil pollution status of the DSDS was of lesser importance. Highest earthworm biomass was observed on sandy loam DSDS disposed at least 40 years ago. - Polluted clayey dredged sediment-derived soils have a relatively low risk for heavy metal biomagnification due to slow earthworm colonisation

Occurrence of organochlorine compounds in Euphausia superba and unhatched eggs of Pygoscelis genus penguins from Admiralty Bay (King George Island, Antarctica) and estimation of biomagnification factors.

Science.gov (United States)

Cipro, Caio V Z; Taniguchi, Satie; Montone, Rosalinda Carmela

2010-02-01

Polychlorinated biphenyls (PCBs) and organochlorine pesticides are compounds that do not occur naturally in the environment and are not easily degraded by chemical or microbiological action. In the present work, those compounds were analysed in unhatched penguin eggs and whole krill collected in Admiralty Bay, King George Island, Antarctica in the austral summers of 2004-2005 and 2005-2006. The compounds found in higher levels (in a wet weight basis) were, in most of the egg samples, the PCBs (2.53-78.7 ng g(-1)), DDTs (2.07-38.0 ng g(-1)) and HCB (4.99-39.1 ng g(-1)) and after Kruskal-Wallis ANOVA, the occurrence seemed to be species-specific for the Pygoscelis genus. In all of the cases, the levels found were not higher than the ones in Arctic birds in a similar trophic level. The krill samples analysis allowed estimating the biomagnification factors (which resulted in up to 363 for HCB, one order of magnitude higher than DDTs and chlordanes and two orders of magnitude higher than the other groups) of the compounds found in eggs, whose only source of contamination is the female-offspring transfer. Copyright 2009 Elsevier Ltd. All rights reserved.

Mercury biomagnification in food webs of the northeastern Chukchi Sea, Alaskan Arctic

Science.gov (United States)

Fox, Austin L.; Trefry, John H.; Trocine, Robert P.; Dunton, Kenneth H.; Lasorsa, Brenda K.; Konar, Brenda; Ashjian, Carin J.; Cooper, Lee W.

2017-10-01

Predictive tools and a large new dataset for the northeastern Chukchi Sea (NECS) are used here to help identify regional differences and potential future shifts in the magnitude of Hg biomagnification in the Arctic. At the base of the food web in the NECS, concentrations of total mercury (THg) in phytoplankton (20-μm mesh) ranged from 4-42 ng g-1 dry weight, partly in response to variations in algal biomass and water temperature. A >3-fold increase in monomethylmercury (MMHg) was observed in zooplankton (4.3±0.7 ng g-1) relative to phytoplankton (150-fold and from 85%, respectively, from phytoplankton to muscle in the whelk Plicifusus kroeyeri (279 ng g-1, TL 4.5). For muscle tissue in 10 species plus whole phytoplankton and zooplankton, the trophic magnification slope (TMS) for MMHg (log10[MMHg]=m(δ15N)+b; where m=TMS) was 0.23±0.02 (SE). No significant differences in TMS were found for the NECS plus three other studies from the eastern Canadian Arctic (average TMS=0.24±0.02). Nevertheless, all data for MMHg in biota from the NECS plotted below the combined best fit line for all four studies. Results from an ANCOVA showed that statistically different (p=0.001) intercept values (b), not TMS, best explained the >2-fold lower concentrations of MMHg in biota from the NECS (b=-1.85) relative to the same species from the eastern Canadian Arctic (b=-1.29). Future changes that affect bioaccumulation of MMHg in the Arctic may impact the biomagnification equation by shifting the TMS, intercept or both. The intercept is more likely to respond to changes in productivity and concentrations of dissolved Hg whereas the TMS may respond to changing growth rates due to fluctuations in productivity and food availability. In either case, small changes in the intercept or TMS coincide with predictably large increases or decreases in MMHg concentrations in apex predators.

Dietary biomagnification of organochlorine contaminants in Alaskan polar bears

Science.gov (United States)

Bentzen, T.W.; Follmann, Erich H.; Amstrup, Steven C.; York, G.S.; Wooller, M.J.; Muir, D.C.G.; O'Hara, T. M.

2008-01-01

Concentrations of organochlorine contaminants in the adipose tissue of polar bears (Ursus maritimus Phipps, 1774) vary throughout the Arctic. The range in concentrations has not been explained fully by bear age, sex, condition, location, or reproductive status. Dietary pathways expose polar bears to a variety of contaminant profiles and concentrations. Prey range from lower trophic level bowhead whales (Balaena mysticetus L., 1758), one of the least contaminated marine mammals, to highly contaminated upper trophic level ringed seals (Phoca hispida (Schreber, 1775)). We used ??15N and ??13C signatures to estimate the trophic status of 42 polar bears sampled along Alaska's Beaufort Sea coast to determine the relationship between organochlorine concentration and trophic level. The ?? 15N values in the cellular portions of blood ranged from 18.2% to 20.7%. We found strong positive relationships between concentrations of the most recalcitrant polychlorinated biphenyls (PCBs) and ??15N values in models incorporating age, lipid content, and ??13C value. Specifically these models accounted for 67% and 76% of the variation in PCB153 and oxychlordane concentration in male polar bears and 85% and 93% in females, respectively. These results are strong indicators of variation in diet and biomagnification of organochlorines among polar bears related to their sex, age, and trophic position. ?? 2008 NRC.

A maternal erythrocyte DHA content of approximately 6 g% is the DHA status at which intrauterine DHA biomagnifications turns into bioattenuation and postnatal infant DHA equilibrium isreached

NARCIS (Netherlands)

Luxwolda, Martine F.; Kuipers, Remko S.; Sango, Wicklif S.; Kwesigabo, Gideon; Dijck-Brouwer, D. A. Janneke; Muskiet, Frits A. J.

Higher long-chain polyunsaturated fatty acids (LCP) in infant compared with maternal lipids at delivery is named biomagnification. The decline of infant and maternal docosahexaenoic acid (DHA) status during lactation in Western countries suggests maternal depletion. We investigated whether

Increasing levels and biomagnification of persistent organic pollutants (POPs) in Antarctic biota

Energy Technology Data Exchange (ETDEWEB)

Goerke, Helmut; Weber, Kurt; Bornemann, Horst; Ramdohr, Sven; Ploetz, Joachim

2004-02-01

Representatives of the Antarctic food web (krill, cephalopod, fish, penguin, seal) of the area around Elephant Island and from the Weddell Sea were analysed for the most recalcitrant organochlorine compounds. Due to sorption of the compounds to sinking particles and accumulation in sediments, two benthic fish species (Gobionotothen gibberifrons, Chaenocephalus aceratus) feeding on benthos invertebrates and fish reflected significantly increasing concentrations within a decade (1987-1996), while a benthopelagic species (Champsocephalus gunnari) feeding on krill did not. In the pelagic food chain, lipid normalised concentrations of all compounds increased from Antarctic krill to fish proving that biomagnification of highly lipophilic pollutants (log octanol-water partition coefficient > 5) occurs in water-breathing animals. As top predators Weddell and southern elephant seals (Leptonychotes weddellii, Mirounga leonina) biomagnified the persistent organic pollutants relative to krill 30-160 fold with the exception of hexachlorobenzene, the levels of which were lower than in fish indicating its intense specific elimination.

Increasing levels and biomagnification of persistent organic pollutants (POPs) in Antarctic biota

International Nuclear Information System (INIS)

Goerke, Helmut; Weber, Kurt; Bornemann, Horst; Ramdohr, Sven; Ploetz, Joachim

2004-01-01

Representatives of the Antarctic food web (krill, cephalopod, fish, penguin, seal) of the area around Elephant Island and from the Weddell Sea were analysed for the most recalcitrant organochlorine compounds. Due to sorption of the compounds to sinking particles and accumulation in sediments, two benthic fish species (Gobionotothen gibberifrons, Chaenocephalus aceratus) feeding on benthos invertebrates and fish reflected significantly increasing concentrations within a decade (1987-1996), while a benthopelagic species (Champsocephalus gunnari) feeding on krill did not. In the pelagic food chain, lipid normalised concentrations of all compounds increased from Antarctic krill to fish proving that biomagnification of highly lipophilic pollutants (log octanol-water partition coefficient > 5) occurs in water-breathing animals. As top predators Weddell and southern elephant seals (Leptonychotes weddellii, Mirounga leonina) biomagnified the persistent organic pollutants relative to krill 30-160 fold with the exception of hexachlorobenzene, the levels of which were lower than in fish indicating its intense specific elimination

Metal and Isotope Analysis of Bird Feathers in a Contaminated Estuary Reveals Bioaccumulation, Biomagnification, and Potential Toxic Effects.

Science.gov (United States)

Einoder, L D; MacLeod, C K; Coughanowr, C

2018-07-01

The Derwent estuary, in south east Tasmania, is highly contaminated with heavy metals, mainly due to past industrial pollution. This study sought to determine the extent of contamination, bioaccumulation, and biomagnification in the resident bird community and therefore to infer the potential for adverse effects in birds. Thirteen metals were measured from breast feathers (n = 51 individuals) of eight sympatric species of aquatic bird. Stable carbon (δ 13 C) and nitrogen (δ 15 N) isotopes were used to identify dietary sources of contaminants, trophic level, and potential biomagnification through food chains. Generalised linear models revealed that metal burdens were often poorly correlated with δ 13 C, indicating their uptake from a range of freshwater, brackish, and marine carbon sources-not surprising due to widespread contamination across the tidal estuary. Feather mercury increased significantly with trophic level (inferred from δ 15 N). White-bellied Sea-eagle Haliaeetus leucogaster samples contained 240 times more mercury than feral Goose Anser cygnoides. Feather arsenic and copper concentrations were significantly higher in birds feeding lower in the food chain. For several piscivorous species, both chick and adults were sampled revealing significantly higher feather mercury, zinc, and selenium in adults. Feathers from birds found dead along the banks of the estuary had significantly higher lead loads than from live birds, and numerous individuals had levels of mercury, zinc, and lead above toxic thresholds reported in other studies. These results highlight the need to include biota from higher trophic levels in contaminant monitoring programs to understand fully the fate and broader implications of contaminants in the environment.

Inflammation, oxidative stress, and higher expression levels of Nrf2 and NQO1 proteins in the airways of women chronically exposed to biomass fuel smoke.

Science.gov (United States)

Mondal, Nandan Kumar; Saha, Hirak; Mukherjee, Bidisha; Tyagi, Neetu; Ray, Manas Ranjan

2018-01-24

The study was carried out to examine whether chronic exposure to smoke during daily household cooking with biomass fuel (BMF) elicits changes in airway cytology and expressions of Nrf2 (nuclear factor erythroid 2 [NF-E2]-related factor 2 [Nrf2]), Keap1 (Kelch-like erythroid-cell-derived protein with CNC homology [ECH]-associated protein 1), and NQO1 (NAD(P)H:quinone oxidoreductase 1) proteins in the airways. For this, 282 BMF-using women (median age 34 year) and 236 age-matched women who cooked with liquefied petroleum gas (LPG) were enrolled. Particulate matter with diameters of LPG. Compared with LPG users, BMF users had 32% more leukocytes in circulation and their sputa were 1.4-times more cellular with significant increase in absolute number of neutrophils, lymphocytes, eosinophils, and alveolar macrophages, suggesting airway inflammation. ROS generation was 1.5-times higher in blood neutrophils and 34% higher in sputum cells of BMF users while erythrocyte SOD was 31% lower and plasma catalase was relatively unchanged, suggesting oxidative stress. In BMF users, Keap1 expression was reduced, the percentage of AEC with nuclear expression of Nrf2 was two- to three-times more, and NQO1 level in sputum cell lysate was two-times higher than that of LPG users. In conclusion, cooking with BMF was associated with Nrf2 activation and elevated NQO1 protein level in the airways. The changes may be adaptive cellular response to counteract biomass smoke-elicited oxidative stress and inflammation-related tissue injury in the airways.

Biomagnification of hexachlorobenzene: influence of uptake routes in a laboratory test

International Nuclear Information System (INIS)

Egeler, P.; Meller, M.; Roembke, J.; Spoerlein, P.

2001-01-01

In order to evaluate such a potential biomagnification, a laboratory test was developed. It consisted of a two-step food chain including the sediment dwelling freshwater oligochaete Tubifex tubifex (Mueller) and the three-spined stickleback (Gasterosteus aculeatus, Linne), a small teleost fish which often feeds primarily on benthic invertebrates. Artificial sediment and reconstituted water were used. To examine the influence of benthic prey on the bioaccumulation of a POP in the predator, fish were exposed to 14 C-labelled hexachlorobenzene via spiked water, spiked sediment, pre-contaminated prey organisms, and to combinations of these exposure routes. Summarising the results of these experiments, it could be shown that the exposure to HCB via different routes resulted in a significantly higher accumulation in fish than an exposure to single pathways. It was concluded that the major uptake routes for fish were the overlying water and the food, whereas the contribution of spiked sediment itself was relatively small. HCB was biomagnified in the tested laboratory food chain. Therefore, concerning secondary poisoning, the environmental risk assessment of POPs like HCB should not be based on existing bioaccumulation tests alone, since they focus only on exposure via the water pathway. Instead, the influence of food and sediment as exposure routes should be considered as well, using comprehensive food chain modelling and/or laboratory studies. (orig.) [de

Rényi statistics for testing composite hypotheses in general exponential models

Czech Academy of Sciences Publication Activity Database

Morales, D.; Pardo, L.; Pardo, M. C.; Vajda, Igor

2004-01-01

Roč. 38, č. 2 (2004), s. 133-147 ISSN 0233-1888 R&D Projects: GA ČR GA201/02/1391 Grant - others:BMF(ES) 2003-00892; BMF(ES) 2003-04820 Institutional research plan: CEZ:AV0Z1075907 Keywords : natural exponential models * Levy processes * generalized Wald statistics Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.323, year: 2004

An integrated approach to model the biomagnification of organic pollutants in aquatic food webs of the Yangtze Three Gorges Reservoir ecosystem using adapted pollution scenarios.

Science.gov (United States)

Scholz-Starke, Björn; Ottermanns, Richard; Rings, Ursula; Floehr, Tilman; Hollert, Henner; Hou, Junli; Li, Bo; Wu, Ling Ling; Yuan, Xingzhong; Strauch, Katrin; Wei, Hu; Norra, Stefan; Holbach, Andreas; Westrich, Bernhard; Schäffer, Andreas; Roß-Nickoll, Martina

2013-10-01

The impounding of the Three Gorges Reservoir (TGR) at the Yangtze River caused large flooding of urban, industrial, and agricultural areas, and profound land use changes took place. Consequently, substantial amounts of organic and inorganic pollutants were released into the reservoir. Additionally, contaminants and nutrients are entering the reservoir by drift, drainage, and runoff from adjacent agricultural areas as well as from sewage of industry, aquacultures, and households. The main aim of the presented research project is a deeper understanding of the processes that determines the bioaccumulation and biomagnification of organic pollutants, i.e., mainly pesticides, in aquatic food webs under the newly developing conditions of the TGR. The project is part of the Yangtze-Hydro environmental program, financed by the German Ministry of Education and Science. In order to test combinations of environmental factors like nutrients and pollution, we use an integrated modeling approach to study the potential accumulation and biomagnification. We describe the integrative modeling approach and the consecutive adaption of the AQUATOX model, used as modeling framework for ecological risk assessment. As a starting point, pre-calibrated simulations were adapted to Yangtze-specific conditions (regionalization). Two exemplary food webs were developed by a thorough review of the pertinent literature. The first typical for the flowing conditions of the original Yangtze River and the Daning River near the city of Wushan, and the second for the stagnant reservoir characteristics of the aforementioned region that is marked by an intermediate between lake and large river communities of aquatic organisms. In close cooperation with German and Chinese partners of the Yangtze-Hydro Research Association, other site-specific parameters were estimated. The MINIBAT project contributed to the calibration of physicochemical and bathymetric parameters, and the TRANSMIC project delivered

Bioaccumulation and biomagnification of mercury and methylmercury in four sympatric coastal sharks in a protected subtropical lagoon

International Nuclear Information System (INIS)

Matulik, Adam G.; Kerstetter, David W.; Hammerschlag, Neil; Divoll, Timothy; Hammerschmidt, Chad R.; Evers, David C.

2017-01-01

Mercury bioaccumulation is frequently observed in marine ecosystems, often with stronger effects at higher trophic levels. We compared total mercury (THg) and methylmercury (MeHg) from muscle with length, comparative isotopic niche, and diet (via δ 13 C and δ 15 N) among four sympatric coastal sharks in Florida Bay (USA): blacknose, blacktip, bull, and lemon. Mercury in blacknose and blacktip sharks increased significantly with size, whereas bull and lemon sharks had a high variance in mercury relative to size. Both δ 13 C and δ 15 N were consistent with general resource use and trophic position relationships across all species. A significant relationship was observed between δ 13 C and mercury in blacktip sharks, suggesting an ontogenetic shift isotopic niche, possibly a dietary change. Multiple regression showed that δ 13 C and δ 15 N were the strongest factors regarding mercury bioaccumulation in individuals across all species. Additional research is recommended to resolve the mechanisms that determine mercury biomagnification in individual shark species. - Highlights: • Total mercury (THg) and methylmercury (MeHg) examined in sympatric coastal sharks: lemon, bull, blacknose, blacktip • THg concentrations increased with size of blacknose and blacktip sharks • THg concentrations in bull and lemon sharks were unrelated to length • THg and δ 13 C were related in blacktip sharks; no other direct relationships between Hg and δ 13 C or δ 15 N and were observed • Multiple regression found δ 13 C and δ 15 N have stronger relationships to Hg than length for the species and lengths assessed

Biomagnification of organochlorine pollutants in farmed and wild gilthead sea bream (Sparus aurata) and stable isotope characterization of the trophic chains

International Nuclear Information System (INIS)

Serrano, Roque; Blanes, Miguel A.; Lopez, Francisco J.

2008-01-01

Organochlorine pollutants (pesticides and polychlorinated biphenyls) were analysed in farmed and wild gilthead sea bream (Sparus aurata) tissues (white muscle and liver) from the Western Mediterranean (Spain) and in their diets. Determination was carried out by gas chromatography coupled to tandem mass spectrometry after clean up of the fatty extracts by normal phase HPLC, with detection limits around 0.1 ng/g. Carbon and nitrogen stable isotope ratios were also determined in the samples. Organochlorine compounds concentration was found to be uniform throughout the year in farmed fish, in both white muscle and liver. In contrast, wild fish showed contamination profiles that reflect environmental factors and the biological cycle. Although biomagnification factors for white muscle and liver were found to be 2.4 and 3.0, respectively for farmed fish, and 0.15 and 0.54 for wild specimens, wild fish presented higher levels of organochlorine contaminants than farmed fish. Nitrogen stable isotopes determination in muscle from wild and farmed sea bream during the year gave us a profile related to the biological cycle. δ 15 N mean values from farmed fish were 2.0 per mille higher than from wild fish throughout the year that corresponding to close to one trophic step. δ 13 C values were stable during the year, and also more enriched in the case of farmed fish. The low levels of contaminants found in the feed supplied to farmed fish explain the organochlorine concentrations in their tissues which remain below wild fish, in spite of the intensive culture conditions and higher trophic level of cultured specimens

Biomagnification of organochlorine pollutants in farmed and wild gilthead sea bream (Sparus aurata) and stable isotope characterization of the trophic chains

Energy Technology Data Exchange (ETDEWEB)

Serrano, Roque [Research Institute for Pesticides and Water (IUPA). Avda Sos Baynat, s/n. University Jaume I, 12071 Castellon (Spain)], E-mail: serrano@qfa.uji.es; Blanes, Miguel A.; Lopez, Francisco J. [Research Institute for Pesticides and Water (IUPA). Avda Sos Baynat, s/n. University Jaume I, 12071 Castellon (Spain)

2008-01-25

Organochlorine pollutants (pesticides and polychlorinated biphenyls) were analysed in farmed and wild gilthead sea bream (Sparus aurata) tissues (white muscle and liver) from the Western Mediterranean (Spain) and in their diets. Determination was carried out by gas chromatography coupled to tandem mass spectrometry after clean up of the fatty extracts by normal phase HPLC, with detection limits around 0.1 ng/g. Carbon and nitrogen stable isotope ratios were also determined in the samples. Organochlorine compounds concentration was found to be uniform throughout the year in farmed fish, in both white muscle and liver. In contrast, wild fish showed contamination profiles that reflect environmental factors and the biological cycle. Although biomagnification factors for white muscle and liver were found to be 2.4 and 3.0, respectively for farmed fish, and 0.15 and 0.54 for wild specimens, wild fish presented higher levels of organochlorine contaminants than farmed fish. Nitrogen stable isotopes determination in muscle from wild and farmed sea bream during the year gave us a profile related to the biological cycle. {delta}{sup 15}N mean values from farmed fish were 2.0 per mille higher than from wild fish throughout the year that corresponding to close to one trophic step. {delta}{sup 13}C values were stable during the year, and also more enriched in the case of farmed fish. The low levels of contaminants found in the feed supplied to farmed fish explain the organochlorine concentrations in their tissues which remain below wild fish, in spite of the intensive culture conditions and higher trophic level of cultured specimens.

Regionalized Techno-Economic Assessment and Policy Analysis for Biomass Molded Fuel in China

Directory of Open Access Journals (Sweden)

Jie Xu

2015-12-01

Full Text Available As a relatively mature technology, biomass molded fuel (BMF is widely used in distributed and centralized heating in China and has received considerable government attention. Although many BFM incentive policies have been developed, decreased domestic traditional fuel prices in China have caused BMF to lose its economic viability and new policy recommendations are needed to stimulate this industry. The present study built a regionalized net present value (NPV model based on real production process simulation to test the impacts of each policy factor. The calculations showed that BMF production costs vary remarkably between regions, with the cost of agricultural briquette fuel (ABF ranging from 86 US dollar per metric ton (USD/t to 110 (USD/t, while that of woody pellet fuel (WPF varies from 122 USD/t to 154 USD/t. The largest part of BMF’s cost composition is feedstock, which accounts for up 50%–60% of the total; accordingly a feedstock subsidy is the most effective policy factor, but in consideration of policy implementation, it would be better to use a production subsidy. For ABF, the optimal product subsidy varies from 26 USD/t to 57 USD/t among different regions of China, while for WPF, the range is 36 USD/t to 75 USD/t. Based on the data, a regional BMF development strategy is also proposed in this study.

O IMPACTO DA MIGRAÇÃO DAS EMPRESAS PARA OS NÍVEIS DIFERENCIADOS DE GOVERNANÇA CORPORATIVA DA BM&F BOVESPA SOBRE O RISCO E O RETORNO DE SUAS AÇÕES./THE IMPACT OF THE MIGRATION OF BUSINESSES TO THE DIFFERENTIATED LEVELS OF BM&F BOVESPA’S CORPORATE GOVERNANCE OVER THE AND RETURN OF ITS SHARES.

Directory of Open Access Journals (Sweden)

Ricardo Luiz Menezes da Silva

2012-08-01

Full Text Available A transparência das informações é importante para se ter uma diminuição na assimetria das mesmas. Quanto mais informações de qualidade há sobre o negócio ou desempenho econômico e financeiro de determinada empresa, teoricamente, mais se pode esperar uma diferente percepção do risco por parte do investidor. O objetivo deste estudo foi verificar se a iniciativa das empresas em aderir aos Níveis Diferenciados de Governança Corporativa da BM&F BOVESPA impacta tanto no risco quanto no retorno dos preços de fechamento de suas ações. Para isso, foram utilizados os retornos diários de 252 dias antes e após a adesão das empresas aos NDGC. Foram feitos os testes de Kolmogorov-Smirnov para análise da normalidade, o teste paramétrico de médias emparelhadas e o teste não paramétrico de Wilcoxon para medidas de risco absoluto (desvio-padrão e relativo (beta, além de retorno. Foram analisados os comportamentos dos papéis de 48 empresas. Os resultados mostraram que as médias dos retornos das açõesempresariais não apresentaram diferenças significativas antes e após a data de adesão aos NDGC. Por outro lado, as proxies de risco apresentaram-se significativamente diferentes./ The transparency of information is important to diminish the asymmetry of information. Themore quality information there is about the business, or financial and economic performance of a certain company, theoretically, the more one can expect a different perception of risk by the investor. The aim of this study was to verify whether the initiative of the companies to adhere to BM&F BOVESPA’s Differentiated Levels of Corporate Governance impacts both at risk and return of the closing price of its shares. For that, daily returns of 252 days before and after the accession of companies to NDGC were used. Over the measures of absolute risk (standard deviation and relative risk (beta, and return, Kolmogorov-Smirnov tests were made in order to analyze normality

Factors affecting {sup 223}Ra therapy: clinical experience after 532 cycles from a single institution

Energy Technology Data Exchange (ETDEWEB)

Etchebehere, Elba C. [The University of Texas MD Anderson Cancer Center, Department of Nuclear Medicine, Houston, TX (United States); Campinas State University (Unicamp), Department of Nuclear Medicine, Campinas (Brazil); Milton, Denai R. [The University of Texas MD Anderson Cancer Center, Department of Biostatistics, Houston, TX (United States); Araujo, John C. [The University of Texas MD Anderson Cancer Center, Department of Genitourinary Medical Oncology, Houston, TX (United States); Swanston, Nancy M.; Macapinlac, Homer A.; Rohren, Eric M. [The University of Texas MD Anderson Cancer Center, Department of Nuclear Medicine, Houston, TX (United States)

2016-01-15

The aim of this study was to identify baseline features that predict outcome in {sup 223}Ra therapy. We retrospectively reviewed 110 patients with metastatic castration-resistant prostate cancer treated with {sup 223}Ra. End points were overall survival (OS), progression-free survival (PFS), bone event-free survival (BeFS), and bone marrow failure (BMF). The following parameters were evaluated prior to the first {sup 223}Ra cycle: serum levels of hemoglobin (Hb), prostate-specific antigen (PSA), alkaline phosphatase (ALP), Eastern Cooperative Oncology Group (ECOG) status, pain score, use of chemotherapy, and external beam radiation therapy (EBRT). During/after {sup 223}Ra we evaluated: the total number of radium cycles (Ra{sub Tot}), the PSA doubling time (PSA{sub DT}), and the use of chemotherapy, EBRT, abiraterone, and enzalutamide. A significant reduction of ALP (p < 0.001) and pain score (p = 0.041) occurred throughout the {sup 223} Ra cycles. The risk of progression was associated with declining ECOG status [hazard ratio (HR) = 3.79; p < 0.001] and decrease in PSA{sub DT} (HR = 8.22; p < 0.001). Ra{sub Tot}, ALP, initial ECOG status, initial pain score, and use of abiraterone were associated with OS (p ≤ 0.008), PFS (p ≤ 0.003), and BeFS (p ≤ 0.020). Ra{sub Tot}, ALP, initial ECOG status, and initial pain score were significantly associated with BMF (p ≤ 0.001) as well as Hb (p < 0.001) and EBRT (p = 0.009). On multivariable analysis, only Ra{sub Tot} and abiraterone remained significantly associated with OS (p < 0.001; p = 0.033, respectively), PFS (p < 0.001; p = 0.041, respectively), and BeFS (p < 0.001; p = 0.019, respectively). Additionally, Ra{sub Tot} (p = 0.027) and EBRT (p = 0.013) remained significantly associated with BMF. Concomitant use of abiraterone and {sup 223}Ra seems to have a beneficial effect, while the EBRT may increase the risk of BMF. (orig.)

Biomagnification of polybrominated diphenyl ether and hexabromocyclododecane flame retardants in the polar bear food chain in Svalbard, Norway.

Science.gov (United States)

Sørmo, Eugen Gravningen; Salmer, Maria Pettersvik; Jenssen, Bjørn Munro; Hop, Haakon; Baek, Kine; Kovacs, Kit Maureen; Lydersen, Christian; Falk-Petersen, Stig; Gabrielsen, Geir Wing; Lie, Elisabeth; Skaare, Janneche Utne

2006-09-01

Concentrations of brominated flame retardants (BFRs), including polybrominated diphenylethers (PBDEs) and hexabromocyclododecane (HBCD), were investigated in an arctic marine food chain consisting of four invertebrate species: polar cod (Boreogadus saida), ringed seals (Pusa hispida), and polar bears (Ursus maritimus). The most abundant BFR, brominated diphenyl ether (BDE)-47, was found in detectable concentrations even in zooplankton, the lowest trophic level examined in this study. Most of the investigated BFRs biomagnified as function of tropic level in the food chain. A noticeable exception occurred at the highest trophic level, the polar bear, in which only BDE-153 was found to increase from its main prey, the ringed seal, indicating that polar bears appear to be able to metabolize and biodegrade most BFRs. In contrast, lower-brominated PBDEs, particularly BDE-47, showed clear signs of bioaccumulation in zooplankton, polar cod, and ringed seals. We suggest that this discrepancy in the fate of BFRs among the different species may be related to greater induction of oxidative detoxification activities in the polar bear. Absorption and debromination rates may be more important for bioaccumulation rates of BFRs in zooplankton, polar cod, and ringed seals. Lipid weight-based concentrations (LWCs) and whole body-based concentrations (WBCs) of BFRs were used to assess biomagnification factors (BMFs). Whole-body concentrations gave the most realistic BMFs, as BMFs derived from LWCs seem to be confounded by the large variability in lipid content of tissues from the investigated species. This study demonstrates that PBDEs and HBCD have reached measurable concentrations even in the lower trophic levels (invertebrates and fish) in the Arctic and biomagnifies in the polar bear food chain.

Informações por Segmento: análise do nível de evidenciação das companhias listadas no novo mercado = Segment reporting: an analysis of the disclosure level of the companies listed on BM&F Bovespa’s new market

OpenAIRE

Camila Weschenfelder; Sady Mazzioni

2014-01-01

As normas internacionais de Contabilidade contribuíram para melhorar o nível de transparência das demonstrações financeiras, disponibilizando informações gerenciais, como as informações por segmento. A pesquisa objetivou verificar o nível de evidenciação do CPC 22 – Informações por segmento – das demonstrações contábeis intermediárias,analisando 127 companhias listadas no Novo Mercado da BM&F Bovespa. A verificação deu-se por meio da análise de conteúdo e posteriormente pelo modelo de regress...

Food web analysis reveals effects of pH on mercury bioaccumulation at multiple trophic levels in streams

International Nuclear Information System (INIS)

Jardine, Timothy D.; Kidd, Karen A.; O’ Driscoll, Nelson

2013-01-01

Highlights: ► We examine biomagnification of Hg through stream food webs using δ15 N. ► Slopes of methyl Hg vs. trophic level were higher than total Hg vs. trophic level. ► Biomagnification from predatory insects to fish was related to pH of the water. ► Biomagnification at lower trophic levels was related to dietary concentrations. ► These trends can explain variation in field-measured Hg in food webs. -- Abstract: Biomagnification processes and the factors that govern them, including those for mercury (Hg), are poorly understood in streams. Total and methyl Hg concentrations and relative trophic position (using δ 15 N) were analyzed in biofilm and invertebrates from 21 streams in New Brunswick, Canada to assess food web biomagnification leading to the common minnow blacknose dace (Rhinichthys atratulus), a species known to have Hg concentrations that are higher in low pH waters. Biomagnification slopes within stream food webs measured using Hg vs. δ 15 N or corresponding trophic levels (TL) differed depending on the chemical species analyzed, with total Hg exhibiting increases of 1.3–2.5 per TL (mean slope of total Hg vs. δ 15 N = 0.14 ± 0.06 S.D., range = 0.06–0.20) and methyl Hg showing a more pronounced increase of 2.8 to 6.0 per TL (mean slope of methyl Hg vs. δ 15 N = 0.30 ± 0.08 S.D., range = 0.22–0.39). While Hg biomagnification slopes through the entire food web (Trophic Magnification Factors, TMFs) were not influenced by water chemistry (pH), dietary concentrations of methyl Hg strongly influenced biomagnification factors (BMFs) for consumer-diet pairs within the food web at lower trophic levels, and BMFs between dace and predatory invertebrates were significantly higher in low pH waters. These analyses, coupled with observations of higher Hg in primary producers in streams with low pH, suggest that pH influences both baseline concentrations and biomagnification of Hg in these systems. Because higher Hg concentrations in the diets

Food web analysis reveals effects of pH on mercury bioaccumulation at multiple trophic levels in streams

Energy Technology Data Exchange (ETDEWEB)

Jardine, Timothy D., E-mail: tim.jardine@usask.ca [Canadian Rivers Institute and Department of Biology, University of New Brunswick, Saint John, NB E2L 4L5 (Canada); Kidd, Karen A. [Canadian Rivers Institute and Department of Biology, University of New Brunswick, Saint John, NB E2L 4L5 (Canada); O’ Driscoll, Nelson [Department of Earth and Environmental Sciences, Acadia University, Wolfville, NS B4P 2R6 (Canada)

2013-05-15

Highlights: ► We examine biomagnification of Hg through stream food webs using δ15 N. ► Slopes of methyl Hg vs. trophic level were higher than total Hg vs. trophic level. ► Biomagnification from predatory insects to fish was related to pH of the water. ► Biomagnification at lower trophic levels was related to dietary concentrations. ► These trends can explain variation in field-measured Hg in food webs. -- Abstract: Biomagnification processes and the factors that govern them, including those for mercury (Hg), are poorly understood in streams. Total and methyl Hg concentrations and relative trophic position (using δ{sup 15}N) were analyzed in biofilm and invertebrates from 21 streams in New Brunswick, Canada to assess food web biomagnification leading to the common minnow blacknose dace (Rhinichthys atratulus), a species known to have Hg concentrations that are higher in low pH waters. Biomagnification slopes within stream food webs measured using Hg vs. δ{sup 15}N or corresponding trophic levels (TL) differed depending on the chemical species analyzed, with total Hg exhibiting increases of 1.3–2.5 per TL (mean slope of total Hg vs. δ{sup 15}N = 0.14 ± 0.06 S.D., range = 0.06–0.20) and methyl Hg showing a more pronounced increase of 2.8 to 6.0 per TL (mean slope of methyl Hg vs. δ{sup 15}N = 0.30 ± 0.08 S.D., range = 0.22–0.39). While Hg biomagnification slopes through the entire food web (Trophic Magnification Factors, TMFs) were not influenced by water chemistry (pH), dietary concentrations of methyl Hg strongly influenced biomagnification factors (BMFs) for consumer-diet pairs within the food web at lower trophic levels, and BMFs between dace and predatory invertebrates were significantly higher in low pH waters. These analyses, coupled with observations of higher Hg in primary producers in streams with low pH, suggest that pH influences both baseline concentrations and biomagnification of Hg in these systems. Because higher Hg

Biomagnification of persistent chlorinated and brominated contaminants in food web components of the Yellow Sea

International Nuclear Information System (INIS)

Byun, Gyo-Hyuk; Moon, Hyo-Bang; Choi, Jung-Hwa; Hwang, Jeomshik; Kang, Chang-Keun

2013-01-01

Highlights: • PCBs, OCPs, and PBDEs were analyzed for 32 marine species in the Yellow Sea. • Their bioaccumulation potentials were assessed in combination with stable isotopes. • Pelagic and benthic food-chain components were separated by their δ 13 C values. • Pelagic food chain was a major bioaccumulation pathway for selected PCBs and OCPs. • The other compounds displayed low bioaccumulation potentials through food chains. -- Abstract: Concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) were measured in 32 species inhabiting the Yellow Sea to assess their bioaccumulation potentials. The concentrations in these samples were lower than those reported for other countries or locations. Relatively high levels of BDE 209 in biota suggest an ongoing source of deca-BDE technical mixing within the Yellow Sea. The accumulation profiles of PCBs were uniform between species, but the concentrations of OCPs and PBDEs varied widely. Pelagic and benthic food-chain components were separated by their δ 13 C values. Significant positive correlations between δ 15 N and PCB 153, PCB 138, p,p′-DDE, oxy-chlordane, and trans-nonachlordane were found only for pelagic consumers, indicating that the pelagic food chain is an important bioaccumulation pathway for selected PCB and OCP compounds. The other compounds did not show any biomagnification through benthic and pelagic food chains, suggesting the lower bioaccumulation potentials of these contaminants

Mercury biomagnification in the food web of Lake Tanganyika (Tanzania, East Africa)

Energy Technology Data Exchange (ETDEWEB)

Campbell, L. [School of Environmental Studies and Department of Biology, Queen' s University, Kingston, Ontario, K7L-3N6 (Canada)], E-mail: linda.campbell@queensu.ca; Verburg, Piet [National Institute of Water and Atmospheric Research, PO Box 11-115, Hamilton 3251 (New Zealand); Dixon, D.G. [Department of Biology, University of Waterloo, 200 University Avenue, Waterloo (Canada); Hecky, R.E. [Large Lakes Observatory, University of Minnesota, Duluth, 10 University Drive 204 RLBDuluth, MN 55812-2496 (United States)

2008-09-01

Lake Tanganyika is a globally important lake with high endemic biodiversity. Millions of people in the lake basin depend on several fish species for consumption. Due to the importance of fish consumption as an exposure route of mercury to humans, we sampled Lake Tanganyika in 2000 to assess total mercury concentrations and biomagnification of total mercury through the food web. Stable nitrogen and carbon isotope analyses of food web structure indicate a complex food web with overlapping omnivory with some specialist fish species. Stable nitrogen isotope analyses further confirm that mercury is biomagnifying through the Tanganyika food web at rates similar to those seen in Lakes Malawi and Victoria, the other two African Great Lakes. Most collected fish species and all invertebrate species had mercury concentrations below 0.2 {mu}g Hg/g wet weight. However, several fish species, Ctenochromis horei (average 0.15 {mu}g/g ww), Neolamprologus boulengeri (0.2 {mu}g/g ww) , Bathybates spp.spp. (0.21 {mu}g/g ww), Mastacembelus cunningtoni (0.22 {mu}g/g ww) and Clarias theodorae (0.22 {mu}g/g ww) approached or slightly exceeded the World Health Organization (WHO)'s recommended guideline of 0.2 {mu}g Hg/g for vulnerable populations with high rates of fish consumption. Two individuals of the piscivorous fish species Lates microlepis (0.54, 0.78 {mu}g/g ww) and a Polypterus congicus (1.3 {mu}g/g ww) exceeded the international marketing limit value of 0.5 {mu}g/g ww. Because C. theodorae and L. microlepis are also important market fish species, there is a need to monitor mercury concentrations in internationally marketed fish from Lake Tanganikya to ensure that those fish do not present a risk to human consumers.

Mercury biomagnification in the food web of Lake Tanganyika (Tanzania, East Africa)

International Nuclear Information System (INIS)

Campbell, L.; Verburg, Piet; Dixon, D.G.; Hecky, R.E.

2008-01-01

Lake Tanganyika is a globally important lake with high endemic biodiversity. Millions of people in the lake basin depend on several fish species for consumption. Due to the importance of fish consumption as an exposure route of mercury to humans, we sampled Lake Tanganyika in 2000 to assess total mercury concentrations and biomagnification of total mercury through the food web. Stable nitrogen and carbon isotope analyses of food web structure indicate a complex food web with overlapping omnivory with some specialist fish species. Stable nitrogen isotope analyses further confirm that mercury is biomagnifying through the Tanganyika food web at rates similar to those seen in Lakes Malawi and Victoria, the other two African Great Lakes. Most collected fish species and all invertebrate species had mercury concentrations below 0.2 μg Hg/g wet weight. However, several fish species, Ctenochromis horei (average 0.15 μg/g ww), Neolamprologus boulengeri (0.2 μg/g ww) , Bathybates spp.spp. (0.21 μg/g ww), Mastacembelus cunningtoni (0.22 μg/g ww) and Clarias theodorae (0.22 μg/g ww) approached or slightly exceeded the World Health Organization (WHO)'s recommended guideline of 0.2 μg Hg/g for vulnerable populations with high rates of fish consumption. Two individuals of the piscivorous fish species Lates microlepis (0.54, 0.78 μg/g ww) and a Polypterus congicus (1.3 μg/g ww) exceeded the international marketing limit value of 0.5 μg/g ww. Because C. theodorae and L. microlepis are also important market fish species, there is a need to monitor mercury concentrations in internationally marketed fish from Lake Tanganikya to ensure that those fish do not present a risk to human consumers

Pluripotent cell models of fanconi anemia identify the early pathological defect in human hemoangiogenic progenitors.

Science.gov (United States)

Suzuki, Naoya M; Niwa, Akira; Yabe, Miharu; Hira, Asuka; Okada, Chihiro; Amano, Naoki; Watanabe, Akira; Watanabe, Ken-Ichiro; Heike, Toshio; Takata, Minoru; Nakahata, Tatsutoshi; Saito, Megumu K

2015-04-01

Fanconi anemia (FA) is a disorder of genomic instability characterized by progressive bone marrow failure (BMF), developmental abnormalities, and an increased susceptibility to cancer. Although various consequences in hematopoietic stem/progenitor cells have been attributed to FA-BMF, the quest to identify the initial pathological event is still ongoing. To address this issue, we established induced pluripotent stem cells (iPSCs) from fibroblasts of six patients with FA and FANCA mutations. An improved reprogramming method yielded iPSC-like colonies from all patients, and iPSC clones were propagated from two patients. Quantitative evaluation of the differentiation ability demonstrated that the differentiation propensity toward the hematopoietic and endothelial lineages is already defective in early hemoangiogenic progenitors. The expression levels of critical transcription factors were significantly downregulated in these progenitors. These data indicate that the hematopoietic consequences in FA patients originate from the early hematopoietic stage and highlight the potential usefulness of iPSC technology for elucidating the pathogenesis of FA-BMF. ©AlphaMed Press.

Confocal laser Raman microspectroscopy of biomineralization foci in UMR 106 osteoblastic cultures reveals temporally synchronized protein changes preceding and accompanying mineral crystal deposition.

Science.gov (United States)

Wang, Chuanyi; Wang, Yong; Huffman, Nichole T; Cui, Chaoying; Yao, Xiaomei; Midura, Sharon; Midura, Ronald J; Gorski, Jeff P

2009-03-13

Mineralization in UMR 106-01 osteoblastic cultures occurs within extracellular biomineralization foci (BMF) within 12 h after addition of beta-glycerol phosphate to cells at 64 h after plating. BMF are identified by their enrichment with an 85-kDa glycoprotein reactive with Maackia amurensis lectin. Laser Raman microspectroscopic scans were made on individual BMF at times preceding (64-76 h) and following the appearance of mineral crystals (76-88 h). The range of variation between spectra for different BMF in the same culture was rather small. In contrast, significant differences were observed for spectral bands at 957-960, 1004, and 1660 cm(-1) when normalized BMF spectra at different times were compared. Protein-dependent spectral bands at 1004 and 1660 cm(-1) increased and then decreased preceding the detection of hydroxyapatite crystals via the phosphate stretching peak at 959-960 cm(-1). When sodium phosphate was substituted for beta-glycerol phosphate, mineralization occurred 3-6 h earlier. Irrespective of phosphate source, the Raman full peak width at half-maximum ratio for 88 h cultures was similar to that for 10-day-old marrow ablation primary bone. However, if mineralization was blocked with serine protease inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride, 64-88-h BMF spectra remained largely invariant. In summary, Raman spectral data demonstrate for the first time that formation of hydroxyapatite crystals within individual BMF is a multistep process. Second, changes in protein-derived signals at 1004 and 1660 cm(-1) reflect events within BMFs that precede or accompany mineral crystal production because they are blocked by mineralization inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride. Finally, the low extent of spectral variability detected among different BMF at the same time point indicates that mineralization of individual BMF within a culture is synchronized.

Confocal Laser Raman Microspectroscopy of Biomineralization Foci in UMR 106 Osteoblastic Cultures Reveals Temporally Synchronized Protein Changes Preceding and Accompanying Mineral Crystal Deposition*

Science.gov (United States)

Wang, Chuanyi; Wang, Yong; Huffman, Nichole T.; Cui, Chaoying; Yao, Xiaomei; Midura, Sharon; Midura, Ronald J.; Gorski, Jeff P.

2009-01-01

Mineralization in UMR 106-01 osteoblastic cultures occurs within extracellular biomineralization foci (BMF) within 12 h after addition of β-glycerol phosphate to cells at 64 h after plating. BMF are identified by their enrichment with an 85-kDa glycoprotein reactive with Maackia amurensis lectin. Laser Raman microspectroscopic scans were made on individual BMF at times preceding (64–76 h) and following the appearance of mineral crystals (76–88 h). The range of variation between spectra for different BMF in the same culture was rather small. In contrast, significant differences were observed for spectral bands at 957–960, 1004, and 1660 cm-1 when normalized BMF spectra at different times were compared. Protein-dependent spectral bands at 1004 and 1660 cm-1 increased and then decreased preceding the detection of hydroxyapatite crystals via the phosphate stretching peak at 959–960 cm-1. When sodium phosphate was substituted for β-glycerol phosphate, mineralization occurred 3–6 h earlier. Irrespective of phosphate source, the Raman full peak width at half-maximum ratio for 88 h cultures was similar to that for 10-day-old marrow ablation primary bone. However, if mineralization was blocked with serine protease inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride, 64–88-h BMF spectra remained largely invariant. In summary, Raman spectral data demonstrate for the first time that formation of hydroxyapatite crystals within individual BMF is a multistep process. Second, changes in protein-derived signals at 1004 and 1660 cm-1 reflect events within BMFs that precede or accompany mineral crystal production because they are blocked by mineralization inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride. Finally, the low extent of spectral variability detected among different BMF at the same time point indicates that mineralization of individual BMF within a culture is synchronized. PMID:19116206

Plant consumption by grizzly bears reduces biomagnification of salmon-derived polychlorinated biphenyls, polybrominated diphenyl ethers, and organochlorine pesticides.

Science.gov (United States)

Christensen, Jennie R; Yunker, Mark B; MacDuffee, Misty; Ross, Peter S

2013-04-01

The present study characterizes the uptake and loss of persistent organic pollutants (POPs) in grizzly bears (Ursus arctos horribilis) by sampling and analyzing their terrestrial and marine foods and fecal material from a remote coastal watershed in British Columbia, Canada. The authors estimate that grizzly bears consume 341 to 1,120 µg of polychlorinated biphenyls (PCBs) and 3.9 to 33 µg of polybrominated diphenyl ethers daily in the fall when they have access to an abundant supply of returning salmon. The authors also estimate that POP elimination by grizzly bears through defecation is very low following salmon consumption (typically 100% for PCBs and organochlorine pesticides). Excretion of individual POPs is largely driven by a combination of fugacity (differences between bear and food concentrations) and the digestibility of the food. The results of the present study are substantiated by a principal components analysis, which also demonstrates a strong role for log KOW in governing the excretion of different POPs in grizzly bears. Collectively, the present study's results reveal that grizzly bears experience a vegetation-associated drawdown of POPs previously acquired through the consumption of salmon, to such an extent that net biomagnification is reduced. Copyright © 2013 SETAC.

Bone marrow fat unsaturation in young adults is not affected by present or childhood obesity, but increases with age: A pilot study.

Science.gov (United States)

Huovinen, Ville; Viljakainen, Heli; Hakkarainen, Antti; Saukkonen, Tero; Toiviainen-Salo, Sanna; Lundbom, Nina; Lundbom, Jesper; Mäkitie, Outi

2015-11-01

Obesity increases bone marrow fat (BMF) content. The association between early obesity and bone marrow fatty acid composition is unknown. We measured BMF unsaturation index (UI) in normal-weight and overweight young adults with a known weight status in early childhood and tested the relationship between BMF UI and exercise history, glycemic state, and other clinical characteristics. The study included 18 normal-weight (BMI young adults aged 15-27 years. BMF UI was assessed with magnetic resonance proton spectroscopy optimized to reduce water interference. Exercise information was obtained with a pedometer accompanied with the history of recent physical activity. Blood samples (insulin, glucose, HbA1c) and body characteristics (BMI, waist-to-hip ratio, body fat composition) were assessed. BMF UI was not affected by obesity at the time of study or before age 7 years. BMF UI increased with age in normal-weight and overweight subjects (R=0.408, p=0.015) but did not associate with gender, physical activity or body fat composition; a suggestive association was observed with glucose (R=-0.289, p=0.10). The association of BMF UI with age in early adulthood may represent normal maturation of bone marrow. There was a trend toward an association with blood glucose, warranting further studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Biomagnification and bioaccumulation of mercury in two fish species from different trophic levels in the Bahia de Cartagena and the Cienaga Grande de Santa Marta, Colombian Caribbean

International Nuclear Information System (INIS)

Alonso, D.; Campos, N.

1999-01-01

During the decade of the 70's a chlor-alkali plant dumped between 11 and 15 tons of mercury indiscriminately into the Bahia de Cartagena (BC), elevating the levels of this metal in the biotic and abiotic components of the ecosystem. Although two decades have passed since the plant was closed, the sediments of the bay seem to be an important source of mercury to the marine environment. The present work measured the contents of mercury in the sediment and determined the processes of bioaccumulation and biomagnification in two species of fishes of commercial importance: the parassi mullet (Mugil incilis) and the striped mojarra (Eugerres plumieri), a detritivore and an omnivore, respectively

DNAJC21 Mutations Link a Cancer-Prone Bone Marrow Failure Syndrome to Corruption in 60S Ribosome Subunit Maturation.

Science.gov (United States)

Tummala, Hemanth; Walne, Amanda J; Williams, Mike; Bockett, Nicholas; Collopy, Laura; Cardoso, Shirleny; Ellison, Alicia; Wynn, Rob; Leblanc, Thierry; Fitzgibbon, Jude; Kelsell, David P; van Heel, David A; Payne, Elspeth; Plagnol, Vincent; Dokal, Inderjeet; Vulliamy, Tom

2016-07-07

A substantial number of individuals with bone marrow failure (BMF) present with one or more extra-hematopoietic abnormality. This suggests a constitutional or inherited basis, and yet many of them do not fit the diagnostic criteria of the known BMF syndromes. Through exome sequencing, we have now identified a subgroup of these individuals, defined by germline biallelic mutations in DNAJC21 (DNAJ homolog subfamily C member 21). They present with global BMF, and one individual developed a hematological cancer (acute myeloid leukemia) in childhood. We show that the encoded protein associates with rRNA and plays a highly conserved role in the maturation of the 60S ribosomal subunit. Lymphoblastoid cells obtained from an affected individual exhibit increased sensitivity to the transcriptional inhibitor actinomycin D and reduced amounts of rRNA. Characterization of mutations revealed impairment in interactions with cofactors (PA2G4, HSPA8, and ZNF622) involved in 60S maturation. DNAJC21 deficiency resulted in cytoplasmic accumulation of the 60S nuclear export factor PA2G4, aberrant ribosome profiles, and increased cell death. Collectively, these findings demonstrate that mutations in DNAJC21 cause a cancer-prone BMF syndrome due to corruption of early nuclear rRNA biogenesis and late cytoplasmic maturation of the 60S subunit. Copyright © 2016. Published by Elsevier Inc.

Demonstração dos fluxos de caixa: uma análise da captação de recursos nas empresas do setor de construção civil listadas na BM&F Bovespa = Cash flow statements: an analysis of resource acquisitions by the civil architecture enterprises listed at BM&F Bovespa

Directory of Open Access Journals (Sweden)

Mariane Lohn

2012-05-01

Full Text Available A dinâmica do mundo econômico e financeiro nas organizações coloca em movimento muito mais que estratégias de gestão e de administração do patrimônio, pois requer uma dinamicidade no conjunto de informações e aporte de procedimentos que organizem e auxiliem o controle patrimonial. As recentes alterações na estrutura conceitual e da legislação societária apresentam novas demandas ao repertório de procedimentos contábeis buscando garantir a confiabilidade nas decisões mediante a divulgação de informações tempestivas. Neste cenário de mudanças e instabilidades esta pesquisa teve como objetivo identificar as formas de obtenção de recursos financeiros utilizados por empresas do segmento da construção civil que negociaram suas ações na BM&F Bovespa. Com este fim foi realizada uma pesquisa bibliográfica e de levantamento de dados. O levantamento abrangeu as demonstrações dos exercícios de 2007 a 2009, no qual se verificou que mais de 80% das empresas captaram recursos principalmente por meio de atividades de financiamento. Quanto a esse grupo de atividades, pode-se perceber que no ano de 2007 a principal forma de capitalização foi por meio de aumento do capital social. Já nos anos de 2008 e de 2009 a obtenção de empréstimos, financiamentos e a emissão de debêntures foram a maior fonte de capitalização. Nota-se que a DFC é um demonstrativo dinâmico nas informações que destacam fontes de financiamento das empresas, enfatizando a relevância dos processos de harmonização contábil, aliados à dinâmica de cenários econômicos que alteram normas e procedimentos, buscando ampliar o fluxo de informações e dinamizando o processo contábil.The dynamics of the financial and economic world demands more from organizations than strategies of management and administration of their capital. It requires more dynamism in obtaining information and adopting procedures to organize and control the companies’ capital

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

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

Ontogenetic patterns in bluefish (Pomatomus saltatrix) feeding ecology and the effect on mercury biomagnification.

Science.gov (United States)

Szczebak, Joseph T; Taylor, David L

2011-06-01

In this study, bluefish (Pomatomus saltatrix; age 0-7, n = 632) and their prey (forage fish, macroinvertebrates, zooplankton; n = 2,005) were collected from the Narragansett Bay estuary (RI, USA), and total Hg concentration was measured in white muscle and whole-body tissues, respectively. Bluefish Hg concentrations were analyzed relative to fish length, prey Hg content, and ontogenetic shifts in habitat use and foraging ecology, the latter assessed using stomach content analysis (n = 711) and stable nitrogen (δ(15)N) and carbon (δ(13)C) isotope measurements (n = 360). Diet and δ(13)C analysis showed that age 0 bluefish consumed both benthic and pelagic prey (silversides, sand shrimp, planktonic crustaceans; δ(13)C = - 16.52‰), whereas age 1 + bluefish fed almost exclusively on pelagic forage fish (Atlantic menhaden, herring; δ(13)C = - 17.33‰). Bluefish total Hg concentrations were significantly correlated with length (mean Hg = 0.041 and 0.254 ppm wet wt for age 0 and age 1 + bluefish, respectively). Furthermore, Hg biomagnification rates were maximal during bluefish early life stages and decelerated over time, resulting in relatively high Hg concentrations in age 0 fish. Rapid Hg accumulation in age 0 bluefish is attributed to these individuals occupying a comparable trophic level to age 1 + bluefish (δ(15)N = 15.58 and 16.09‰; trophic level = 3.55 and 3.71 for age 0 and age 1 + bluefish, respectively), as well as juveniles having greater standardized consumption rates of Hg-contaminated prey. Finally, bluefish larger than 30 cm total length consistently had Hg levels above the U.S. Environmental Protection Agency criterion of 0.3 ppm. As such, frequent consumption of bluefish could pose a human health risk, and preferentially consuming smaller bluefish may be an inadequate strategy for minimizing human dietary exposure to Hg. Copyright © 2011 SETAC.

A review of suspension-Scattered particles used in blood-mimicking fluid for doppler ultrasound imaging

Directory of Open Access Journals (Sweden)

Ammar A Oglat

2018-01-01

Full Text Available Doppler ultrasound imaging system description and calibration need blood-mimicking fluids (BMFs for the test target of medical ultrasound diagnostic tools, with known interior features and acoustic and physical properties of this fluid (BMF. Physical and acoustical properties determined in the International Electrotechnical Commission (IEC standard are specified as constant values, the materials used in the BMF preparation should have values similar to the IEC standard values. However, BMF is ready-made commercially from a field of medical usage, which may not be appropriate in the layout of ultrasound system or for an estimate of novel imaging mechanism. It is often eligible to have the capability to make sound properties and mimic blood arrangement for specific applications. In this review, sufficient BMF materials, liquids, and measures are described which have been generated by utilizing diverse operation mechanism and materials that have sculptured a range of biological systems.

The influence of double flask investing on tooth displacement in dentures processed by microwave irradiation.

Science.gov (United States)

Farias Neto, Arcelino; Sousa, Rodrigo L dos Santos; Rizzatti-Barbosa, Célia M

2012-06-01

This study evaluated the influence of the bimaxillary flask (BMF) and two different investing materials on first molar inclination in dentures processed by microwave irradiation. The BMF may minimise tooth displacement, saving time and improving occlusion. Forty pairs of dentures were randomised into four groups: stone wall in monomaxillary flask; silicone wall in BMF; stone wall in BMF; acrylic resin retentions and silicone in BMF. Dentures were processed by microwave irradiation. Two referential points were established on tooth surface. A microscope and a digital pachymeter were used to measure the distance between these points, and the angles α (right maxillary molar), β (left maxillary molar), α' (right mandibular molar) and β' (left mandibular molar) were calculated by the law of cosines. Data were submitted to Kruskal-Wallis (5% significance). No difference was observed among the groups (p > 0.05). In the intra-group analysis, α was significantly different for groups I, II and III; α', for groups II and IV; β, for all groups; β', for groups III and IV. First molar inclination was similar for monomaxillary and BMFs. The use of stone or silicone as investing materials presented the same effect on tooth inclination. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

Should students design or interact with models? Using the Bifocal Modelling Framework to investigate model construction in high school science

Science.gov (United States)

Fuhrmann, Tamar; Schneider, Bertrand; Blikstein, Paulo

2018-05-01

The Bifocal Modelling Framework (BMF) is an approach for science learning which links students' physical experimentation with computer modelling in real time, focusing on the comparison of the two media. In this paper, we explore how a Bifocal Modelling implementation supported learning outcomes related to both content and metamodeling knowledge, focusing on the role of designing models. Our study consisted of three conditions implemented with a total of 69 9th grade high-school students. The first and second classes were assigned two implementation modes of BMF: with and without a model design module. The third condition, employed as a control, consisted of a class that received instruction in the school's traditional approach. Our results indicate that students participating in both BMF implementations demonstrated improved content knowledge and a better understanding of metamodeling. However, only the 'BMF-with-design' group improved significantly in both content and metamodeling knowledge. Our qualitative analyses indicate that both BMF groups designed detailed models that included scientific explanations. However only students who engaged in the model design component: (1) completed a detailed model displaying molecular interaction; and (2) developed a critical perspective about models. We discuss the implications of those results for teaching scientific science concepts and metamodeling knowledge.

Mercury and selenium biomagnification in a Brazilian coastal food web using nitrogen stable isotope analysis: A case study in an area under the influence of the Paraiba do Sul River plume

International Nuclear Information System (INIS)

Kehrig, Helena A.; Seixas, Tercia G.; Malm, Olaf; Di Beneditto, Ana Paula M.; Rezende, Carlos E.

2013-01-01

Highlights: • Cetacean and voracious fish displayed similar δ 15 N values. • Cetacean displayed higher Hg and lower Se than voracious fish. • Hg showed an elevated biomagnification power over the entire tropical food web. • Se biomagnified in lower and intermediate trophic positions. • Five trophic positions were found in relation to primary consumer as baseline. -- Abstract: Mercury (Hg), selenium (Se) and nitrogen (δ 15 N) stable isotope were assessed in a tropical food web of Rio de Janeiro’s north coast. Isotopic data on muscle suggest a difference related to this parameter along the food web; where top-predators (cetacean and voracious fish) displayed heavier δ 15 N over the entire food web. Both top-predators presented similar δ 15 N values. Cetacean displayed higher Hg and lower Se than voracious fish. Five trophic positions (TP) were found in relation to primary consumer as baseline, ranging from 2.0 to 4.0. Positive relationships were found between trace-element and δ 15 N. The slope of regression equations (0.11 for Se and 0.21 for Hg) and food web magnification factors (2.4 for Se and 5.4 for Hg) showed that Hg presented higher rate of increase over the food web. Simultaneous measurements of trace-elements and ecological tracers emphasize the importance of TP into the trophic structure and distribution of Hg and Se throughout the food web

Uptake of americium-241 by algae and bacteria

Energy Technology Data Exchange (ETDEWEB)

Geisy, J P; Paine, D

1978-01-01

Algae and bacteria are important factors in the transport and mobilization of elements in the biosphere. These factors may be involved in trophic biomagnification, resulting in a potential human hazard or environmental degradation. Although americium, one of the most toxic elements known, is not required for plant growth, it may be concentrated by algae and bacteria. Therefore, the availability of americium-241 to algae and bacteria was studied to determine their role in the ultimate fate of this element released into the environment. Both algae and bacteria concentrated americium-241 to a high degree, making them important parts of the biomagnification process. The ability to concentrate americium-241 makes algae and bacteria potentially significant factors in cycling this element in the water column. (4 graphs, numerous references, 3 tables)

Consistency in trophic magnification factors of cyclic methyl siloxanes in pelagic freshwater food webs leading to brown trout.

Science.gov (United States)

Borgå, Katrine; Fjeld, Eirik; Kierkegaard, Amelie; McLachlan, Michael S

2013-12-17

Cyclic volatile methyl siloxanes (cVMS) concentrations were analyzed in the pelagic food web of two Norwegian lakes (Mjøsa, Randsfjorden), and in brown trout (Salmo trutta) and Arctic char (Salvelinus alpinus) collected in a reference lake (Femunden), in 2012. Lakes receiving discharge from wastewater treatment plants (Mjøsa and Randsfjorden) had cVMS concentrations in trout that were up to 2 orders of magnitude higher than those in Femunden, where most samples were close to the limit of quantification (LOQ). Food web biomagnification of cVMS in Mjøsa and Randsfjorden was quantified by estimation of trophic magnification factors (TMFs). TMF for legacy persistent organic pollutants (POPs) were analyzed for comparison. Both decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) biomagnified with TMFs of 2.9 (2.1-4.0) and 2.3 (1.8-3.0), respectively. Octamethylcyclotetrasiloxane (D4) was below the LOQ in the majority of samples and had substantially lower biomagnification than for D5 and D6. The cVMS TMFs did not differ between the lakes, whereas the legacy POP TMFs were higher in Mjøsa than inRandsfjorden. Whitefish had lower cVMS bioaccumulation compared to legacy POPs, and affected the TMF significance for cVMS, but not for POPs. TMFs of D5 and legacy contaminants in Lake Mjøsa were consistent with those previously measured in Mjøsa.

RESOLVE AND ECO: THE HALO MASS-DEPENDENT SHAPE OF GALAXY STELLAR AND BARYONIC MASS FUNCTIONS

Energy Technology Data Exchange (ETDEWEB)

Eckert, Kathleen D.; Kannappan, Sheila J.; Stark, David V.; Moffett, Amanda J.; Norris, Mark A. [Department of Physics and Astronomy, University of North Carolina, 141 Chapman Hall CB 3255, Chapel Hill, NC 27599 (United States); Berlind, Andreas A., E-mail: keckert@physics.unc.edu [International Centre for Radio Astronomy Research (ICRAR), The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)

2016-06-20

In this work, we present galaxy stellar and baryonic (stars plus cold gas) mass functions (SMF and BMF) and their halo mass dependence for two volume-limited data sets. The first, RESOLVE-B, coincides with the Stripe 82 footprint and is extremely complete down to baryonic mass M {sub bary} ∼ 10{sup 9.1} M {sub ⊙}, probing the gas-rich dwarf regime below M {sub bary} ∼ 10{sup 10} M {sub ⊙}. The second, ECO, covers a ∼40× larger volume (containing RESOLVE-A) and is complete to M {sub bary} ∼ 10{sup 9.4} M {sub ⊙}. To construct the SMF and BMF we implement a new “cross-bin sampling” technique with Monte Carlo sampling from the full likelihood distributions of stellar or baryonic mass. Our SMFs exhibit the “plateau” feature starting below M {sub star} ∼ 10{sup 10} M {sub ⊙} that has been described in prior work. However, the BMF fills in this feature and rises as a straight power law below ∼10{sup 10} M {sub ⊙}, as gas-dominated galaxies become the majority of the population. Nonetheless, the low-mass slope of the BMF is not as steep as that of the theoretical dark matter halo MF. Moreover, we assign group halo masses by abundance matching, finding that the SMF and BMF, separated into four physically motivated halo mass regimes, reveal complex structure underlying the simple shape of the overall MFs. In particular, the satellite MFs are depressed below the central galaxy MF “humps” in groups with mass <10{sup 13.5} M {sub ⊙} yet rise steeply in clusters. Our results suggest that satellite destruction and stripping are active from the point of nascent group formation. We show that the key role of groups in shaping MFs enables reconstruction of a given survey’s SMF or BMF based on its group halo mass distribution.

Informações por Segmento: análise do nível de evidenciação das companhias listadas no novo mercado = Segment reporting: an analysis of the disclosure level of the companies listed on BM&F Bovespa’s new market

Directory of Open Access Journals (Sweden)

Camila Weschenfelder

2014-08-01

Full Text Available As normas internacionais de Contabilidade contribuíram para melhorar o nível de transparência das demonstrações financeiras, disponibilizando informações gerenciais, como as informações por segmento. A pesquisa objetivou verificar o nível de evidenciação do CPC 22 – Informações por segmento – das demonstrações contábeis intermediárias,analisando 127 companhias listadas no Novo Mercado da BM&F Bovespa. A verificação deu-se por meio da análise de conteúdo e posteriormente pelo modelo de regressão linear múltipla. Os resultados sinalizaram que companhias com emissão de ADR’s tendem a divulgar menos informações por segmento que as demais. Algumas companhias não citam o CPC 22 nas suas demonstrações contábeis e nenhuma evidenciou a Demonstração do Fluxo de Caixa por segmento.Poucas empresas investigadas citaram o grau de dependência dos principais clientes, o montante de investimentos contabilizados por equivalência patrimonial e a conciliação entre as informações por segmento e o balanço patrimonial. Companhias auditadas por Big Four apresentam menor nível de evidenciação do que as demais. Conclui-se que o nível de evidenciação de informações por segmento é baixo e distinto entre os setores. The international accounting standards have contributed to improve the financial statements transparency providing managing information, as the ones by segment. This research has aimed at checking the CPC 22 disclosure level – Segment reporting – from the intermediate financial statements of the 127 companies listed on BM&F Bovespa’s New Market. This checking has been performed by the Content Analysis and, further, by the Multiple Regression analysis Pattern. The results showed that the companies with ADR’s tend to disclosure less information about segment reporting than others. Some companies do not mention in their financial statements and none of them highlighted the Cash Flow Demonstration by

Modulation of inflammasome-mediated pulmonary immune activation by type I IFNs protects bone marrow homeostasis during systemic responses to Pneumocystis lung infection.

Science.gov (United States)

Searles, Steve; Gauss, Katherine; Wilkison, Michelle; Hoyt, Teri R; Dobrinen, Erin; Meissner, Nicole

2013-10-01

Although acquired bone marrow failure (BMF) is considered a T cell-mediated autoimmune disease, possible innate immune defects as a cause for systemic immune deviations in response to otherwise innocuous infections have not been extensively explored. In this regard, we recently demonstrated an important role of type I IFNs in protecting hematopoiesis during systemic stress responses to the opportunistic fungal pathogen Pneumocystis in lymphocyte-deficient mice. Mice deficient in both lymphocytes and type I IFN receptor (IFrag(-/-) mice) develop rapidly progressing BMF due to accelerated bone marrow (BM) cell apoptosis associated with innate immune deviations in the BM in response to Pneumocystis lung infection. However, the communication pathway between lung and BM eliciting the induction of BMF in response to this strictly pulmonary infection has been unclear. In this study, we report that absence of an intact type I IFN system during Pneumocystis lung infection not only causes BMF in lymphocyte-deficient mice but also transient BM stress in lymphocyte-competent mice. This is associated with an exuberant systemic IFN-γ response. IFN-γ neutralization prevented Pneumocystis lung infection-induced BM depression in type I IFN receptor-deficient mice and prolonged neutrophil survival time in BM from IFrag(-/-) mice. IL-1β and upstream regulators of IFN-γ, IL-12, and IL-18 were also upregulated in lung and serum of IFrag(-/-) mice. In conjunction, there was exuberant inflammasome-mediated caspase-1 activation in pulmonary innate immune cells required for processing of IL-18 and IL-1β. Thus, absence of type I IFN signaling during Pneumocystis lung infection may result in deregulation of inflammasome-mediated pulmonary immune activation, causing systemic immune deviations triggering BMF in this model.

Replacement of corn with babassu mesocarp flour in balanced rations for broilers in the period from 1 to 21 days

Directory of Open Access Journals (Sweden)

Flávia Luzia Rodrigues Fonseca

2015-06-01

Full Text Available The objective of this study was to evaluate the technical and economic feasibility of partial replacement of corn with babassu mesocarp flour in diets for broilers from one to 21 days of age. Two hundred male day-old chicks, from the Cobb 500® line, were distributed in a completely randomized design with four treatments (0%, 10%, 20% and 30% replacement of maize flour with the babassu mesocarp and five replicates were used comprising ten birds. Were evaluated performance (weight gain, feed intake, feed conversion and water intake, organ biometrics, metabolizability coefficients of dry matter (MCDM, crude protein (MCCP and gross energy (MCGE and cost of feeding diets containing babassu mesocarp flour (BMF. It was observed that the substitution of corn with BMF negatively influenced (P 0.05 the relative weights of the carcass, bursa, spleen, heart, gizzard or liver, nor the relative weight or length of the small intestine. The lower cost of feed per kg of weight gain was obtained with the diet containing 10% corn replacement with BMF, which resulted in a higher gross margin in relation to food. The replacement of corn with BMF in diets for broilers from one to 21 days of age proved to be technically feasible in 10%.

Species-specific accumulation of polybrominated diphenyl ether flame retardants in birds of prey from the Chesapeake Bay region, USA

Energy Technology Data Exchange (ETDEWEB)

Chen Da, E-mail: chen@vims.ed [Department of Environmental and Aquatic Animal Health, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA 23062 (United States); Hale, Robert C. [Department of Environmental and Aquatic Animal Health, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA 23062 (United States); Watts, Bryan D. [Center for Conservation Biology, College of William and Mary, Williamsburg, VA 23185 (United States); La Guardia, Mark J.; Harvey, Ellen [Department of Environmental and Aquatic Animal Health, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA 23062 (United States); Mojica, Elizabeth K. [Center for Conservation Biology, College of William and Mary, Williamsburg, VA 23185 (United States)

2010-05-15

Compared to organochlorines, little is known about polybrominated diphenyl ether (PBDE) contamination of birds of prey breeding in the Chesapeake Bay, the largest estuary in the U.S. This study examined and compared PBDE contamination in eggs of osprey, double-crested cormorant, brown pelican and peregrine falcon from this area. Several legacy persistent organic pollutants such as PCBs and DDE were also investigated. The level of urbanization of the landscape appeared to influence the level of PBDE exposure. PBDE congener distribution patterns varied between piscivorous and terrestrial-feeding birds. This suggests individual congeners may be subject to differences in bioaccumulation, biomagnification or metabolism in the aquatic and terrestrial food webs. Biomagnification of PBDEs was studied in the Bay aquatic food chains for the first time. A biomagnification factor of 25.1 was estimated for SIGMAPBDEs for the fish - osprey egg food chain. Hazard quotients, applied as a preliminary evaluation, indicated that PBDEs may pose a moderate hazard to ospreys and peregrine falcons through impairment of reproductive performance. - Birds of prey breeding in the Chesapeake Bay (USA) exhibited species-specific PBDE accumulation patterns.

Species-specific accumulation of polybrominated diphenyl ether flame retardants in birds of prey from the Chesapeake Bay region, USA

International Nuclear Information System (INIS)

Chen Da; Hale, Robert C.; Watts, Bryan D.; La Guardia, Mark J.; Harvey, Ellen; Mojica, Elizabeth K.

2010-01-01

Compared to organochlorines, little is known about polybrominated diphenyl ether (PBDE) contamination of birds of prey breeding in the Chesapeake Bay, the largest estuary in the U.S. This study examined and compared PBDE contamination in eggs of osprey, double-crested cormorant, brown pelican and peregrine falcon from this area. Several legacy persistent organic pollutants such as PCBs and DDE were also investigated. The level of urbanization of the landscape appeared to influence the level of PBDE exposure. PBDE congener distribution patterns varied between piscivorous and terrestrial-feeding birds. This suggests individual congeners may be subject to differences in bioaccumulation, biomagnification or metabolism in the aquatic and terrestrial food webs. Biomagnification of PBDEs was studied in the Bay aquatic food chains for the first time. A biomagnification factor of 25.1 was estimated for ΣPBDEs for the fish - osprey egg food chain. Hazard quotients, applied as a preliminary evaluation, indicated that PBDEs may pose a moderate hazard to ospreys and peregrine falcons through impairment of reproductive performance. - Birds of prey breeding in the Chesapeake Bay (USA) exhibited species-specific PBDE accumulation patterns.

Food web accumulation of cyclic siloxanes in Lake Mjøsa, Norway.

Science.gov (United States)

Borgå, Katrine; Fjeld, Eirik; Kierkegaard, Amelie; McLachlan, Michael S

2012-06-05

The biomagnification of the cyclic volatile methyl siloxanes octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexatetrasiloxane (D6) was analyzed in the Lake Mjøsa food web in Norway from zooplankton and Mysis to planktivorous and piscivorous fish. The trophic magnification factor (TMF) for D5 was determined and compared with TMFs of several legacy contaminants: polychlorinated biphenyl (PCB) congeners 153 and 180, polybrominated diphenyl ether (PBDE) congeners 47 and 99, and p,p'-DDE. D5 showed TMF significantly greater than 1, implying food web biomagnification (TMF = 2.28, CI: 1.22-4.29). This contrasts with two studies that reported TMF < 1, which may reflect variability in TMF between food webs. The Lake Mjøsa D5 TMF was sensitive to the species included at the higher trophic level; whole food web TMF differed from TMF excluding smelt (Osmerus eperlanus) or brown trout (Salmo trutta) (TMF(-SMELT) = 1.62, CI: 0.96-2.72; TMF(-TROUT) = 3.58, CI: 1.82-7.03). For legacy contaminants (e.g., PCB-153 and PCB-180), the TMFs were less sensitive to the food web composition, and a better model fit was obtained compared to D5. The differences in biomagnification behavior between D5 and the legacy contaminants suggest that the biomagnification of D5 is being governed by species-specific properties such as biotransformation rate or tissue distribution that differ from those of legacy contaminants.

Environmental contaminants in great blue herons (Ardea herodias) from the lower Columbia and Willamette Rivers, Oregon and Washington, USA

Energy Technology Data Exchange (ETDEWEB)

Thomas, C.M.; Anthony, R.G.

1999-12-01

Great blue heron (Ardea herodias) eggs and prey items were collected from six colonies in Oregon and Washington, USA, during 1994 to 1995. Contaminant concentrations, reproductive success, and biomagnification factors were determined and effects of residue levels were measured by H4IIE rat hepatoma bioassays. Mean residue concentrations in heron eggs and prey items were generally low. However, elevated concentrations of polychlorinated biphenyls (PCBs) were detected in eggs and prey from Ross Island on the Willamette River. Biomagnification factors varied among sites. Sites were not significantly different in H4IIE tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQs), although the TCDD-EQ for Karlson Island was 9 to 20 times greater than that of any other site. Large differences existed between toxic equivalents calculated from egg residue concentrations and TCDD-EQs, which indicated nonadditive interactions among the compounds. Tetrachlorodibenzo-p-dioxin equivalents and nest failure were positively correlated with TCDD concentration. Fledging and reproductive rates were similar to those determined for healthy heron populations, however, indicating that any adverse effects were occurring at the individual level and not at the colony level. Their results support the use of great blue herons as a biomonitor for contamination in aquatic ecosystems. Their relatively low sensitivity to organochlorine contaminants and high trophic position allows contaminant accumulation and biomagnification without immediate adverse effects that are often seen in other, more sensitive species.

Hexabromocyclododecane in terrestrial passerine birds from e-waste, urban and rural locations in the Pearl River Delta, South China: Levels, biomagnification, diastereoisomer- and enantiomer-specific accumulation

International Nuclear Information System (INIS)

Sun Yuxin; Luo Xiaojun; Mo Ling; He Mingjing; Zhang Qiang; Chen Shejun; Zou Fasheng; Mai Bixian

2012-01-01

Diastereoisomers and enantiomers of hexabromocyclododecane (HBCD) were determined in muscle and stomach contents of three terrestrial passerine birds from e-waste, urban and rural locations in South China. The highest HBCD concentration was found at the urban site, followed by the e-waste site, suggesting that HBCD was linked to urbanization and industrialization, as well as e-waste recycling activities. Trophic magnification for α-HBCD was observed in the terrestrial food chain. Diastereisomeric pattern in birds showed the predominance of α-isomer, with a minor contribution of γ-isomer. The enantiomeric analysis revealed a preferential enrichment of (−)-α-HBCD and (+)-γ-HBCD. The similarity in enantiomeric fractions of HBCD isomers between muscle and stomach contents of birds suggested that dietary uptake may be responsible for the observed nonracemic distribution of HBCD isomers in the studied birds although in vivo enantioselective biotic processes cannot be ruled out. - Highlights: ► HBCD concentrations in three terrestrial passerine birds and their stomach contents were determined. ► Biomagnification and trophic magnification for α-HBCD was found. ► A preferential enrichment of (−)-α-HBCD and (+)-γ-HBCD were found in birds. ► Diet rather than in vivo biotic processes contributed to the observed nonracemic distribution of HBCD isomers. - Enantiomer-specific accumulation of hexabromocyclododecane in terrestrial passerine birds in South China was demonstrated.

A survey of perfluorinated compounds in surface water and biota including dolphins from the Ganges River and in other waterbodies in India

Digital Repository Service at National Institute of Oceanography (India)

Yeung, L.W.Y.; Yamashita, N.; Taniyasu, S.; Lam, P.K.S.; Sinha, R; Borole, D.V.; Kannan, K.

and biomagnifications factors of PFCs were estimated in the Ganges River basin food web. The highest concentration of PFOA, 23.1 ng L sup(-1), was found in untreated sewage samples. Overall, concentrations of PFCs of water and biological samples from India are lower...

Ecological and spatial factors drive intra- and interspecific variation in exposure of subarctic predatory bird nestlings to persistent organic pollutants.

Science.gov (United States)

Eulaers, Igor; Jaspers, Veerle L B; Bustnes, Jan O; Covaci, Adrian; Johnsen, Trond V; Halley, Duncan J; Moum, Truls; Ims, Rolf A; Hanssen, Sveinn A; Erikstad, Kjell E; Herzke, Dorte; Sonne, Christian; Ballesteros, Manuel; Pinxten, Rianne; Eens, Marcel

2013-07-01

Top predators in northern ecosystems may suffer from exposure to persistent organic pollutants (POPs) as this exposure may synergistically interact with already elevated natural stress in these ecosystems. In the present study, we aimed at identifying biological (sex, body condition), ecological (dietary carbon source, trophic level) and spatial factors (local habitat, regional nest location) that may influence intra- and interspecific variation in exposure of subarctic predatory bird nestlings to polychlorinated biphenyl 153 (CB 153), polybrominated diphenyl ether 47 (BDE 47), dichlorodiphenyldichloroethylene (p,p'-DDE) and hexachlorobenzene (HCB). During three breeding seasons (2008-2010), we sampled body feathers from fully-grown nestlings of three ecologically distinct predatory bird species in subarctic Norway: Northern Goshawk (Accipiter gentilis), White-tailed Eagle (Haliaeetus albicilla) and Golden Eagle (Aquila chrysaetos). The present study analysed, for the first time, body feathers for both POPs and carbon (δ(13)C) and nitrogen (δ(15)N) stable isotopes, thus integrating the dietary carbon source, trophic level and POP exposure for the larger part of the nestling stage. Intraspecific variation in exposure was driven by a combination of ecological and spatial factors, often different for individual compounds. In addition, combinations for individual compounds differed among species. Trophic level and local habitat were the predominant predictors for CB 153, p,p'-DDE and BDE 47, indicating their biomagnification and decreasing levels according to coast>fjord>inland. Variation in exposure may also have been driven by inter-annual variation arisen from primary sources (e.g. p,p'-DDE) and/or possible revolatilisation from secondary sources (e.g. HCB). Interspecific differences in POP exposure were best explained by a combination of trophic level (biomagnification), dietary carbon source (food chain discrimination) and regional nest location (historical POP

Análise do nível de adesão ao disclosure do risco de mercado pelos bancos com ações negociadas na BM&FBOVESPA

OpenAIRE

Vinícius Costa da Silva Zonatto; Tarcita Cabral Ghizoni de Sousa; Francisco Carlos Fernandes

2015-01-01

O objetivo deste estudo é analisar o nível de adesão ao disclosure do risco de mercado pelas instituições financeiras com ações negociadas na Bolsa de Valores, Mercadorias e Futuros (BM&F Bovespa), no tocante às recomendações do Acordo de Basileia II, em especial pelos bancos listados nos Níveis Diferenciados de Governança Corporativa da BM&F Bovespa. A metodologia utilizada na pesquisa consistiu num estudo descritivo, realizado por meio de uma pesquisa documental, com abordagem q...

Bioaccumulation and trophic transfer of mercury and selenium in african sub-tropical fluvial reservoirs food webs (Burkina Faso.

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Ousséni Ouédraogo

Full Text Available The bioaccumulation and biomagnification of mercury (Hg and selenium (Se were investigated in sub-tropical freshwater food webs from Burkina Faso, West Africa, a region where very few ecosystem studies on contaminants have been performed. During the 2010 rainy season, samples of water, sediment, fish, zooplankton, and mollusks were collected from three water reservoirs and analysed for total Hg (THg, methylmercury (MeHg, and total Se (TSe. Ratios of δ13C and δ15N were measured to determine food web structures and patterns of contaminant accumulation and transfer to fish. Food chain lengths (FCLs were calculated using mean δ15N of all primary consumer taxa collected as the site-specific baseline. We report relatively low concentrations of THg and TSe in most fish. We also found in all studied reservoirs short food chain lengths, ranging from 3.3 to 3.7, with most fish relying on a mixture of pelagic and littoral sources for their diet. Mercury was biomagnified in fish food webs with an enrichment factor ranging from 2.9 to 6.5 for THg and from 2.9 to 6.6 for MeHg. However, there was no evidence of selenium biomagnification in these food webs. An inverse relationship was observed between adjusted δ15N and log-transformed Se:Hg ratios, indicating that Se has a lesser protective effect in top predators, which are also the most contaminated animals with respect to MeHg. Trophic position, carbon source, and fish total length were the factors best explaining Hg concentration in fish. In a broader comparison of our study sites with literature data for other African lakes, the THg biomagnification rate was positively correlated with FCL. We conclude that these reservoir systems from tropical Western Africa have low Hg biomagnification associated with short food chains. This finding may partly explain low concentrations of Hg commonly reported in fish from this area.

Toxicity and trophic transfer of P25 TiO2 NPs from Dunaliella salina to Artemia salina: Effect of dietary and waterborne exposure.

Science.gov (United States)

Bhuvaneshwari, M; Thiagarajan, Vignesh; Nemade, Prateek; Chandrasekaran, N; Mukherjee, Amitava

2018-01-01

The recent increase in nanoparticle (P25 TiO 2 NPs) usage has led to concerns regarding their potential implications on environment and human health. The food chain is the central pathway for nanoparticle transfer from lower to high trophic level organisms. The current study relies on the investigation of toxicity and trophic transfer potential of TiO 2 NPs from marine algae Dunaliella salina to marine crustacean Artemia salina. Toxicity was measured in two different modes of exposure such as waterborne (exposure of TiO 2 NPs to Artemia) and dietary exposure (NP-accumulated algal cells are used to feed the Artemia). The toxicity and accumulation of TiO 2 NPs in marine algae D. salina were also studied. Artemia was found to be more sensitive to TiO 2 NPs (48h LC 50 of 4.21mgL -1 ) as compared to marine algae, D. salina (48h LC 50 of 11.35mgL -1 ). The toxicity, uptake, and accumulation of TiO 2 NPs were observed to be more in waterborne exposure as compared to dietary exposure. Waterborne exposure seemed to cause higher ROS production and antioxidant enzyme (SOD and CAT) activity as compared to dietary exposure of TiO 2 NPs in Artemia. There were no observed biomagnification (BMF) and trophic transfer from algae to Artemia through dietary exposure. Histopathological studies confirmed the morphological and internal damages in Artemia. This study reiterates the possible effects of the different modes of exposure on trophic transfer potential of TiO 2 NPs and eventually the consequences on aquatic environment. Copyright © 2017 Elsevier Inc. All rights reserved.

Heterozygous RTEL1 variants in bone marrow failure and myeloid neoplasms.

Science.gov (United States)

Marsh, Judith C W; Gutierrez-Rodrigues, Fernanda; Cooper, James; Jiang, Jie; Gandhi, Shreyans; Kajigaya, Sachiko; Feng, Xingmin; Ibanez, Maria Del Pilar F; Donaires, Flávia S; Lopes da Silva, João P; Li, Zejuan; Das, Soma; Ibanez, Maria; Smith, Alexander E; Lea, Nicholas; Best, Steven; Ireland, Robin; Kulasekararaj, Austin G; McLornan, Donal P; Pagliuca, Anthony; Callebaut, Isabelle; Young, Neal S; Calado, Rodrigo T; Townsley, Danielle M; Mufti, Ghulam J

2018-01-09

Biallelic germline mutations in RTEL1 (regulator of telomere elongation helicase 1) result in pathologic telomere erosion and cause dyskeratosis congenita. However, the role of RTEL1 mutations in other bone marrow failure (BMF) syndromes and myeloid neoplasms, and the contribution of monoallelic RTEL1 mutations to disease development are not well defined. We screened 516 patients for germline mutations in telomere-associated genes by next-generation sequencing in 2 independent cohorts; one constituting unselected patients with idiopathic BMF, unexplained cytopenia, or myeloid neoplasms (n = 457) and a second cohort comprising selected patients on the basis of the suspicion of constitutional/familial BMF (n = 59). Twenty-three RTEL1 variants were identified in 27 unrelated patients from both cohorts: 7 variants were likely pathogenic, 13 were of uncertain significance, and 3 were likely benign. Likely pathogenic RTEL1 variants were identified in 9 unrelated patients (7 heterozygous and 2 biallelic). Most patients were suspected to have constitutional BMF, which included aplastic anemia (AA), unexplained cytopenia, hypoplastic myelodysplastic syndrome, and macrocytosis with hypocellular bone marrow. In the other 18 patients, RTEL1 variants were likely benign or of uncertain significance. Telomeres were short in 21 patients (78%), and 3' telomeric overhangs were significantly eroded in 4. In summary, heterozygous RTEL1 variants were associated with marrow failure, and telomere length measurement alone may not identify patients with telomere dysfunction carrying RTEL1 variants. Pathogenicity assessment of heterozygous RTEL1 variants relied on a combination of clinical, computational, and functional data required to avoid misinterpretation of common variants.

Evaluation of the effects of chronic biomass fuel smoke exposure on peripheral endothelial functions: an observational study.

Science.gov (United States)

Buturak, Ali; Genç, Ahmet; Ulus, Ozden Sıla; Duygu, Egemen; Okmen, Arda Sanlı; Uyarel, Hüseyin

2011-09-01

To evaluate the effect of chronic biomass fuel (BMF) smoke exposure on peripheral endothelial functions. Forty-seven healthy subjects who have been exposed to BMF smoke since birth (mean age 31.6±6.8 years, 21 male) were enrolled in the present cross-sectional observational study. The control group consisted of 32 healthy subjects (mean age 27.9±4.4 years, 11 male). The carotid intima media thickness (CIMT), flow associated dilatation (FAD %) and endothelium independent vasodilatation (GTN %) were assessed in all subjects. The carotid CIMT was defined as the distance between the leading edge of the lumen-intima and the media-adventitia interfaces. FAD % was defined as the percentage change in the internal diameter of the brachial artery during reactive hyperemia related to the baseline. GTN % was defined as the change in diameter in response to the application of 400 µg of glyceril trinitrate relative to the baseline scan at the end of the fourth minute. Statistical analysis was performed using Student's t-test, Chi-square test and Spearman rank order correlation analysis. The average exposure time of the subjects to biomass fuel smoke was 31.7±6.6 years. They have been exposed to dung inhalation products meanly 8.3±1.8 months in a year seasonally. The average daily exposure time was 15.7±3.3 hours. CIMT values of the two groups were not statistically different from each other (0.47±0.09 vs. 0.49±0.06 mm, p=0.138). However, a markedly reduced FAD % was determined in the study group (5.06±4.95 vs. 10.7±4.64, pinhalation products. Therefore, chronic BMF smoke exposure may be a risk factor for the development of endothelial dysfunction.

Concentrations and trophic magnification of cyclic siloxanes in aquatic biota from the Western Basin of Lake Erie, Canada

International Nuclear Information System (INIS)

McGoldrick, Daryl J.; Chan, Cecilia; Drouillard, Ken G.; Keir, Michael J.; Clark, Mandi G.; Backus, Sean M.

2014-01-01

We examine the concentrations and food web biomagnification of three cyclic volatile methylsiloxanes (cVMS) octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) using aquatic biota collected from Lake Erie. Concentrations of cVMS in biota were within the range reported for other studies of cVMS in aquatic biota. Trophic magnification factors (TMF) were assessed in various food web configurations to investigate the effects of food web structure. TMF estimates were highly dependent on the inclusion/exclusion of the organisms occupying the highest and lowest trophic levels and were >1 for D4 and D5, indicating biomagnification, in only 1 of the 5 food web configurations investigated and were <1 in the remaining 4 food web configurations. TMF estimates for PCB180 were also dependant on food web configuration, but did not correspond with those obtained for cVMS materials. These differences may be attributed to environmental exposure and/or lipid partitioning differences between PCB180 and cVMS. -- Highlights: • We investigated trophic magnification of siloxanes in aquatic biota from Lake Erie. • Trophic magnification estimates were variable and sensitive to food web structure. • Lipid partitioning of siloxanes and PCBs differ and may contribute to variability. -- Biomagnification estimates for siloxanes in Lake Erie are sensitive to food web structure, contaminant exposure pathways, and lipid partitioning differences between PCBs and siloxanes

Utility of the immature platelet fraction in pediatric immune thrombocytopenia: Differentiating from bone marrow failure and predicting bleeding risk.

Science.gov (United States)

McDonnell, Alicia; Bride, Karen L; Lim, Derick; Paessler, Michele; Witmer, Char M; Lambert, Michele P

2018-02-01

Differentiating childhood immune thrombocytopenia (ITP) from other cause of thrombocytopenia remains a diagnosis of exclusion. Additionally factors that predict bleeding risk for those patients with ITP are currently not well understood. Previous small studies have suggested that immature platelet fraction (IPF) may differentiate ITP from other causes of thrombocytopenia and in combination with other factors may predict bleeding risk. We performed a retrospective chart review of thrombocytopenic patients with an IPF measured between November 1, 2013 and July 1, 2015. Patients were between 2 months and 21 years of age with a platelet count bleeding symptoms. A bleeding severity score was retrospectively assigned. Two hundred seventy two patients met inclusion criteria, 97 with ITP, 11 with bone marrow failure (BMF), 126 with malignancy, and 38 with other causes of thrombocytopenia. An IPF > 5.2% differentiated ITP from BMF with 93% sensitivity and 91% specificity. Absolute immature platelet number (AIPN) was significantly lower in ITP patients with severe to life-threatening hemorrhage than those without, despite similar platelet counts. On multivariate analysis, an IPF bleeding risk at platelet counts <10 × 10 9 /l in patients with ITP. IPF measurement alone has utility in both the diagnosis of ITP and identifying patients at increased risk of hemorrhage. Further study is required to understand the pathophysiological differences of ITP patients with lower IPF/AIPN. © 2017 Wiley Periodicals, Inc.

A hipótese das expectativas na estrutura a termo de juros no Brasil: uma aplicação de modelos de valor presente

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Alexandre Maia Correia Lima

2003-12-01

Full Text Available Utilizando dados financeiros brasileiros da BM&F, testa-se a validade do modelo de valor presente na estrutura a termo de juros, também conhecido na literatura como Hipótese das Expectativas. Estes modelos relacionam a taxa de juros de longo prazo à uma média das taxas de juros de curto-prazo mais um prêmio de risco, invariante no tempo. Associada a estes modelos está a questão da previsibilidade dos retornos de ativos financeiros ou, mais especificamente, à previsibilidade na evolução das taxas de juros. Neste artigo é realizada uma análise multivariada num arcabouço de séries temporais utilizando a técnica de Auto-Regressão Vetorial. Os resultados empíricos aceitam apenas parcialmente a Hipótese das Expectativas para a estrutura a termo de juros brasileira.Using Brazilian financial data provided by BMF we test the expectations hypothesis of interest rates present value models (Campbell and Shiller, 1987. The empirical results are ambiguos: we find a common factor for ''long'' and short interest rates (cointegration, but present-value restrictions are rejected at 10% significance but not at 5%.

Superlattice structure of Ce{sup 3+}-doped BaMgF{sub 4} fluoride crystals - x-ray diffraction, electron spin-resonance, and optical investigations

Energy Technology Data Exchange (ETDEWEB)

Yamaga, M.; Hattori, K. [Department of Electrical and Electronic Engineering, Faculty of Engineering, Gifu University, Gifu (Japan); Kodama, N. [Department of Materials Science and Engineering, Faculty of Engineering and Resource Science, Akita University, Akita (Japan); Ishizawa, N. [Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama (Japan); Honda, M. [Faculty of Science, Naruto University of Education, Naruto (Japan); Shimamura, K.; Fukuda, T. [Institute for Materials Research, Tohoku University, Sendai (Japan)

2001-09-14

The x-ray diffraction patterns for Ce{sup 3+}-doped BaMgF{sub 4} (BMF) crystals suggest the existence of superlattice structure. The superlattice model is consistent with the characterization of the 4f{sup 1} ground state of Ce{sup 3+} as a probe ion using the electron spin-resonance (ESR) technique. The distinct Ce{sup 3+} luminescence spectra with different peak energies and lifetimes also support the superlattice model. Although the detailed superlattice structure could not be analysed using the diffraction spots, a model has been proposed, taking into account the eight Ce{sup 3+} polyhedra with different anion coordinations in the unit cell of the BMF crystal obtained from the ESR experiments. (author)

Trophodynamics of inorganic pollutants in a wide-range feeder: The relevance of dietary inputs and biomagnification in the Yellow-legged gull (Larus michahellis)

International Nuclear Information System (INIS)

Ramos, Raül; Ramírez, Francisco; Jover, Lluís

2013-01-01

The suitability of sentinel species to monitor environmental pollution is often hampered by an insufficient knowledge on pollutant trophodynamics. We simultaneously evaluated the influence of individuals' trophic position (as revealed by δ 15 N values) and dietary exploitation of particular systems (using δ 13 C and δ 34 S as proxies) on inorganic pollutant concentrations measured on fledglings' feathers of a wide-range feeder, the Yellow-legged Gull (Larus michahellis), sampled at four locations throughout the Western Mediterranean. Concentrations of total Hg and Se in fledgling feathers (2.43 ± 1.30 and 1.16 ± 0.43 μg/g, respectively) were under the threshold points for deleterious effects on seabirds. On the contrary, alarming Pb concentrations were found in one colony (mean: 1.57 ± 2.46 μg/g, range: 0.16–12.13). With the exception of Pb, pollutant concentrations were positively influenced by consumption of marine resources (as suggested by the positive relationship with δ 34 S values), whereas trophic position played a minor role in determining pollutant body burdens. - Graphical abstract: Individual feeding behaviours in wide-range feeders may represent unavoidable knowledge for an appropriate understanding of contaminant acquisition, adding complexity to the study of the dynamic of contaminants throughout food chains. In this case study, pollutant body burden of Yellow-legged gull (Larus michahellis) chicks was highly influenced by dietary exposure, whereas the influence of trophic position was relatively low. Display Omitted Highlights: ► Diet origin (δ 34 S) and trophic position (δ 15 N) were tested relative to Hg, Se, and Pb levels. ► Hg and Se concentrations in gull feathers were highly influenced by δ 34 S signatures. ► Exploited habitat influenced pollutant levels to a greater extent than trophic position. ► Biomagnification processes contribute less to contamination exposure in wide-range feeders. - Pollutant body burden of a wide

JNK Promotes Epithelial Cell Anoikis by Transcriptional and Post-translational Regulation of BH3-Only Proteins

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Nomeda Girnius

2017-11-01

Full Text Available Summary: Developmental morphogenesis, tissue injury, and oncogenic transformation can cause the detachment of epithelial cells. These cells are eliminated by a specialized form of apoptosis (anoikis. While the processes that contribute to this form of cell death have been studied, the underlying mechanisms remain unclear. Here, we tested the role of the cJUN NH2-terminal kinase (JNK signaling pathway using murine models with compound JNK deficiency in mammary and kidney epithelial cells. These studies demonstrated that JNK is required for efficient anoikis in vitro and in vivo. Moreover, JNK-promoted anoikis required pro-apoptotic members of the BCL2 family of proteins. We show that JNK acts through a BAK/BAX-dependent apoptotic pathway by increasing BIM expression and phosphorylating BMF, leading to death of detached epithelial cells. : Developmental morphogenesis, tissue injury, and oncogenic transformation can cause epithelial cell detachment. These cells are eliminated by a specialized form of apoptosis termed anoikis. Girnius and Davis show that anoikis is mediated by the cJUN NH2-terminal kinase (JNK, which increases BIM expression and phosphorylates BMF to engage BAK/BAX-dependent apoptosis. Keywords: apoptosis, anoikis, epithelial cell, mammary gland, JNK, BAX, BAK, BH3-only protein, BIM, BMF

Fanconi anemia.

Science.gov (United States)

Soulier, Jean

2011-01-01

Fanconi anemia (FA) is the most frequent inherited cause of BM failure (BMF). Fifteen FANC genes have been identified to date, the most prevalent being FANCA, FANCC, FANCG, and FANCD2. In addition to classical presentations with progressive BMF during childhood and a positive chromosome breakage test in the blood, atypical clinical and/or biological situations can be seen in which a FA diagnosis has to be confirmed or eliminated. For this, a range of biological tools have been developed, including analysis of skin fibroblasts. FA patients experience a strong selective pressure in the BM that predisposes to clonal evolution and to the emergence in their teens or young adulthood of myelodysplasia syndrome (MDS) and/or acute myeloid leukemia (AML) with a specific pattern of somatic chromosomal lesions. The cellular mechanisms underlying (1) the hematopoietic defect which leads to progressive BMF and (2) somatic clonal evolutions in this background, are still largely elusive. Elucidation of these mechanisms at the molecular and cellular levels should be useful to understand the physiopathology of the disease and to adapt the follow-up and treatment of FA patients. This may also ultimately benefit older, non-FA patients with aplastic anemia, MDS/AML for whom FA represents a model genetic condition.

WE-DE-207B-11: Implementation of Size-Specific 3D Beam Modulation Filters On a Dedicated Breast CT Platform Using Breast Immobilization

Energy Technology Data Exchange (ETDEWEB)

Hernandez, A [Department of Radiology, Biomedical Engineering Graduate Group, University of California Davis, Sacramento, CA (United States); Boone, J [Departments of Radiology and Biomedical Engineering, University of California Davis, Sacramento, CA (United States)

2016-06-15

Purpose: To implement a 3D beam modulation filter (3D-BMF) in dedicated breast CT (bCT) and develop a method for conforming the patient’s breast to a pre-defined shape, optimizing the effects of the filter. This work expands on previous work reporting the methodology for designing a 3D-BMF that can spare unnecessary dose and improve signal equalization at the detector by preferentially filtering the beam in the thinner anterior and peripheral breast regions. Methods: Effective diameter profiles were measured for 219 segmented bCT images, grouped into volume quintiles, and averaged within each group to represent the range of breast sizes found clinically. These profiles were then used to generate five size-specific computational phantoms and fabricate five size-specific UHMW phantoms. Each computational phantom was utilized for designing a size-specific 3D-BMF using previously reported methods. Glandular dose values and projection images were simulated in MCNP6 with and without the 3DBMF using the system specifications of our prototype bCT scanner “Doheny”. Lastly, thermoplastic was molded around each of the five phantom sizes and used to produce a series of breast immobilizers for use in conforming the patient’s breast during bCT acquisition. Results: After incorporating the 3D-BMF, MC simulations estimated an 80% average reduction in the detector dynamic range requirements across all phantom sizes. The glandular dose was reduced on average 57% after normalizing by the number of quanta reaching the detector under the thickest region of the breast. Conclusion: A series of bCT-derived breast phantoms were used to design size-specific 3D-BMFs and breast immobilizers that can be used on the bCT platform to conform the patient’s breast and therefore optimally exploit the benefits of the 3D-BMF. Current efforts are focused on fabricating several prototype 3D-BMFs and performing phantom scans on Doheny for MC simulation validation and image quality analysis

WE-DE-207B-11: Implementation of Size-Specific 3D Beam Modulation Filters On a Dedicated Breast CT Platform Using Breast Immobilization

International Nuclear Information System (INIS)

Hernandez, A; Boone, J

2016-01-01

Purpose: To implement a 3D beam modulation filter (3D-BMF) in dedicated breast CT (bCT) and develop a method for conforming the patient’s breast to a pre-defined shape, optimizing the effects of the filter. This work expands on previous work reporting the methodology for designing a 3D-BMF that can spare unnecessary dose and improve signal equalization at the detector by preferentially filtering the beam in the thinner anterior and peripheral breast regions. Methods: Effective diameter profiles were measured for 219 segmented bCT images, grouped into volume quintiles, and averaged within each group to represent the range of breast sizes found clinically. These profiles were then used to generate five size-specific computational phantoms and fabricate five size-specific UHMW phantoms. Each computational phantom was utilized for designing a size-specific 3D-BMF using previously reported methods. Glandular dose values and projection images were simulated in MCNP6 with and without the 3DBMF using the system specifications of our prototype bCT scanner “Doheny”. Lastly, thermoplastic was molded around each of the five phantom sizes and used to produce a series of breast immobilizers for use in conforming the patient’s breast during bCT acquisition. Results: After incorporating the 3D-BMF, MC simulations estimated an 80% average reduction in the detector dynamic range requirements across all phantom sizes. The glandular dose was reduced on average 57% after normalizing by the number of quanta reaching the detector under the thickest region of the breast. Conclusion: A series of bCT-derived breast phantoms were used to design size-specific 3D-BMFs and breast immobilizers that can be used on the bCT platform to conform the patient’s breast and therefore optimally exploit the benefits of the 3D-BMF. Current efforts are focused on fabricating several prototype 3D-BMFs and performing phantom scans on Doheny for MC simulation validation and image quality analysis

Trophic transfer of microplastics in aquatic ecosystems: Identifying critical research needs.

Science.gov (United States)

Au, Sarah Y; Lee, Cindy M; Weinstein, John E; van den Hurk, Peter; Klaine, Stephen J

2017-05-01

To evaluate the process of trophic transfer of microplastics, it is important to consider various abiotic and biotic factors involved in their ingestion, egestion, bioaccumulation, and biomagnification. Toward this end, a review of the literature on microplastics has been conducted to identify factors influencing their uptake and absorption; their residence times in organisms and bioaccumulation; the physical effects of their aggregation in gastrointestinal tracts; and their potential to act as vectors for the transfer of other contaminants. Limited field evidence from higher trophic level organisms in a variety of habitats suggests that trophic transfer of microplastics may be a common phenomenon and occurs concurrently with direct ingestion. Critical research needs include standardizing methods of field characterization of microplastics, quantifying uptake and depuration rates in organisms at different trophic levels, quantifying the influence that microplastics have on the uptake and/or depuration of environmental contaminants among different trophic levels, and investigating the potential for biomagnification of microplastic-associated chemicals. More integrated approaches involving computational modeling are required to fully assess trophic transfer of microplastics. Integr Environ Assess Manag 2017;13:505-509. © 2017 SETAC. © 2017 SETAC.

Modelo de Cinco Fatores de Risco: precificando carteiras setoriais no mercado acionário brasileiro = Five risk factors model: pricing sectoral portfolios in the Brazilian stock market

Directory of Open Access Journals (Sweden)

Matheus Duarte Valente Vieira

2017-08-01

Full Text Available O prêmio de risco dos ativos é a variável central dos modelos de finanças que buscam estimar o custo do capital das empresas, custo esse empregado, por exemplo, na avaliação do preço das ações. São diversos os modelos empregados para o cálculo do prêmio de risco. Os modelos de Fama e French são amplamente conhecidos e difundidos. Em 2015, Fama e French apresentaram um novo modelo com a introdução de dois novos prêmios de risco. Devido à relevância do tema e à possibilidade de conseguir novas informações a partir desse novo modelo, o objetivo do trabalho é realizar um estudo no mercado de ações brasileiro a partir de uma amostra composta por empresas listadas na Bolsa de Valores de São Paulo (BMF&Bovespa, testando a capacidade de precificação setorial dos fatores de risco presentes no recente modelo de 5-fatores, proposto por Fama e French (2015a. Para a realização da pesquisa foram utilizadas as empresas listadas na Bovespa entre o período de janeiro de 2008 e dezembro de 2015. Os resultados apontam para uma importância maior do prêmio de risco atrelado aos investimentos, estatisticamente significativo em três dos cinco setores da economia estudados. The assets risk premium is the central variable of the finance models that seek to estimate the cost of capital of the companies, the cost of this employee, for example, in the evaluation of the stock price. There are several models used to calculate the risk premium, with Fama and French models being widely known and widely disseminated. In 2015, Fama and French introduced a new model with the introduction of two new risk premiums. Due to the relevance of the theme and the possibility of obtaining new information from this new model, the objective of this paper is to conduct a study in the Brazilian stock market from a sample composed of companies listed on the São Paulo Stock Exchange (BMF&Bovespa, testing the ability of sectoral pricing in the risk factors

Bioaccumulation of per- and polyfluorinated alkyl substances (PFAS) in selected species from the Barents Sea food web.

Science.gov (United States)

Haukås, Marianne; Berger, Urs; Hop, Haakon; Gulliksen, Bjørn; Gabrielsen, Geir W

2007-07-01

The present study reports concentrations and biomagnification potential of per- and polyfluorinated alkyl substances (PFAS) in species from the Barents Sea food web. The examined species included sea ice amphipod (Gammarus wilkitzkii), polar cod (Boreogadus saida), black guillemot (Cepphus grylle) and glaucous gull (Larus hyperboreus). These were analyzed for PFAS, polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs) and polybrominated diphenyl ethers (PBDEs). Perfluorooctane sulfonate (PFOS) was the predominant of the detected PFAS. Trophic levels and food web transfer of PFAS were determined using stable nitrogen isotopes (delta(15)N). No correlation was found between PFOS concentrations and trophic level within species. However, a non-linear relationship was established when the entire food web was analyzed. Biomagnification factors displayed values >1 for perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA), PFOS and SigmaPFAS(7). Multivariate analyses showed that the degree of trophic transfer of PFAS is similar to that of PCB, DDT and PBDE, despite their accumulation through different pathways.

Diastereomer-specific bioaccumulation of hexabromocyclododecane (HBCD) in a coastal food web, Western Norway

International Nuclear Information System (INIS)

Haukas, Marianne; Hylland, Ketil; Nygard, Torgeir; Berge, John Arthur; Mariussen, Espen

2010-01-01

The present study reports diastereomer-specific accumulation of HBCD from a point source in five marine species representing a typical food web in a Norwegian coastal area. Samples of mussels, polychaetes, crabs and seabird eggs were analyzed for the diastereomers α-, β- and γ-HBCD, as well as lipid content and stable isotopes of nitrogen ( 15 N/ 14 N) to estimate trophic level. Accumulated HBCD did not correlate well with lipid content for most of the species, thus wet-weight based concentrations were included in an assessment of biomagnification. In contrast to β- and γ-HBCD, the α-diastereomer increased significantly with trophic level, resulting in magnification factors > 1 in this coastal marine ecosystem. Data for poikilotherms did not show the same positive correlation between the α-diastereomer and trophic position as homeotherms. The apparent biomagnification of the α-HBCD could be due to bioisomerization or diastereomer-specific elimination that differed between poikilotherms and homeotherms.

Biomagnification of hexachlorobenzene: influence of uptake routes in a laboratory test; Aufnahmepfade von POPs in Biota. Biomagnifikation von Hexachlorobenzol im Labortest

Energy Technology Data Exchange (ETDEWEB)

Egeler, P.; Meller, M.; Roembke, J.; Spoerlein, P. [ECT Oekotoxikologie GmbH, Floersheim/Main (Germany)

2001-07-01

In order to evaluate such a potential biomagnification, a laboratory test was developed. It consisted of a two-step food chain including the sediment dwelling freshwater oligochaete Tubifex tubifex (Mueller) and the three-spined stickleback (Gasterosteus aculeatus, Linne), a small teleost fish which often feeds primarily on benthic invertebrates. Artificial sediment and reconstituted water were used. To examine the influence of benthic prey on the bioaccumulation of a POP in the predator, fish were exposed to {sup 14}C-labelled hexachlorobenzene via spiked water, spiked sediment, pre-contaminated prey organisms, and to combinations of these exposure routes. Summarising the results of these experiments, it could be shown that the exposure to HCB via different routes resulted in a significantly higher accumulation in fish than an exposure to single pathways. It was concluded that the major uptake routes for fish were the overlying water and the food, whereas the contribution of spiked sediment itself was relatively small. HCB was biomagnified in the tested laboratory food chain. Therefore, concerning secondary poisoning, the environmental risk assessment of POPs like HCB should not be based on existing bioaccumulation tests alone, since they focus only on exposure via the water pathway. Instead, the influence of food and sediment as exposure routes should be considered as well, using comprehensive food chain modelling and/or laboratory studies. (orig.) [German] Zur standardisierten Bestimmung der Bioakkumulation und - magnifikation wurde eine einfache, zwei trophische Stufen umfassende Labornahrungskette etabliert. Diese bestand aus dem endobenthischen Oligochaeten Tubifex tubifex und dem Dreistachligen Stichling (Gasterosteus aculeatus) als Praedator. Die Experimente wurden mit {sup 14}C-markiertem Hexachlorbenzol in dotiertem kuenstlichem Sediment und rekonstituiertem Wasser durchgefuehrt. Um den Einfluss benthischer Beuteorganismen zu quantifizeren, wurden die

Biallelic inactivation of REV7 is associated with Fanconi anemia.

Science.gov (United States)

Bluteau, Dominique; Masliah-Planchon, Julien; Clairmont, Connor; Rousseau, Alix; Ceccaldi, Raphael; Dubois d'Enghien, Catherine; Bluteau, Olivier; Cuccuini, Wendy; Gachet, Stéphanie; Peffault de Latour, Régis; Leblanc, Thierry; Socié, Gérard; Baruchel, André; Stoppa-Lyonnet, Dominique; D'Andrea, Alan D; Soulier, Jean

2016-09-01

Fanconi anemia (FA) is a recessive genetic disease characterized by congenital abnormalities, chromosome instability, progressive bone marrow failure (BMF), and a strong predisposition to cancer. Twenty FA genes have been identified, and the FANC proteins they encode cooperate in a common pathway that regulates DNA crosslink repair and replication fork stability. We identified a child with severe BMF who harbored biallelic inactivating mutations of the translesion DNA synthesis (TLS) gene REV7 (also known as MAD2L2), which encodes the mutant REV7 protein REV7-V85E. Patient-derived cells demonstrated an extended FA phenotype, which included increased chromosome breaks and G2/M accumulation upon exposure to DNA crosslinking agents, γH2AX and 53BP1 foci accumulation, and enhanced p53/p21 activation relative to cells derived from healthy patients. Expression of WT REV7 restored normal cellular and functional phenotypes in the patient's cells, and CRISPR/Cas9 inactivation of REV7 in a non-FA human cell line produced an FA phenotype. Finally, silencing Rev7 in primary hematopoietic cells impaired progenitor function, suggesting that the DNA repair defect underlies the development of BMF in FA. Taken together, our genetic and functional analyses identified REV7 as a previously undescribed FA gene, which we term FANCV.

Migration of acute lymphoblastic leukemia cells into human bone marrow stroma.

Science.gov (United States)

Makrynikola, V; Bianchi, A; Bradstock, K; Gottlieb, D; Hewson, J

1994-10-01

Most cases of acute lymphoblastic leukemia (ALL) arise from malignant transformation of B-cell precursors in the bone marrow. Recent studies have shown that normal and leukemic B-cell precursors bind to bone marrow stromal cells through the beta-1 integrins VLA-4 and VLA-5, thereby exposing early lymphoid cells to regulatory cytokines. It has been recently reported that the pre-B cell line NALM-6 is capable of migrating under layers of murine stromal cells in vitro (Miyake et al. J Cell Biol 1992;119:653-662). We have further analyzed leukemic cell motility using human bone marrow fibroblasts (BMF) as a stromal layer. The precursor-B ALL cell line NALM-6 rapidly adhered to BMF, and underwent migration or tunneling into BMF layers within 5 h, as demonstrated by light and electron microscopy, and confirmed by a chromium-labeling assay. Migration was also observed with the precursor-B ALL lines Reh and KM-3, with a T leukemia line RPMI-8402, the monocytic line U937, and the mature B line Daudi. In contrast, mature B (Raji), myeloid (K562, HL-60), and T lines (CCRF-CEM, MOLT-4) did not migrate. When cases of leukemia were analyzed, BMF migration was largely confined to precursor-B ALL, occurring in eight of 13 cases tested. Of other types of leukemia, migration was observed in one of four cases of T-ALL, but no evidence was seen in six acute myeloid leukemias and two patients with chronic lymphocytic leukemia. Only minimal migration into BMF was observed with purified sorted CD10+ CD19+ early B cells from normal adult marrow, while normal mature B lymphocytes from peripheral blood did not migrate. ALL migration was inhibited by monoclonal antibodies to the beta sub-unit of the VLA integrin family, and by a combination of antibodies to VLA-4 and VLA-5. Partial inhibition was also observed when leukemic cells were incubated with antibodies to VLA-4, VLA-5, or VLA-6 alone. In contrast, treatment of stromal cells with antibodies to vascular cell adhesion molecule or

Bioaccumulation of per- and polyfluorinated alkyl substances (PFAS) in selected species from the Barents Sea food web

International Nuclear Information System (INIS)

Haukas, Marianne; Berger, Urs; Hop, Haakon; Gulliksen, Bjorn; Gabrielsen, Geir W.

2007-01-01

The present study reports concentrations and biomagnification potential of per- and polyfluorinated alkyl substances (PFAS) in species from the Barents Sea food web. The examined species included sea ice amphipod (Gammarus wilkitzkii), polar cod (Boreogadus saida), black guillemot (Cepphus grylle) and glaucous gull (Larus hyperboreus). These were analyzed for PFAS, polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs) and polybrominated diphenyl ethers (PBDEs). Perfluorooctane sulfonate (PFOS) was the predominant of the detected PFAS. Trophic levels and food web transfer of PFAS were determined using stable nitrogen isotopes (δ 15 N). No correlation was found between PFOS concentrations and trophic level within species. However, a non-linear relationship was established when the entire food web was analyzed. Biomagnification factors displayed values >1 for perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA), PFOS and ΣPFAS(7). Multivariate analyses showed that the degree of trophic transfer of PFAS is similar to that of PCB, DDT and PBDE, despite their accumulation through different pathways. - The first comprehensive survey of fluoroorganic contamination in an European Arctic marine food web

Disrupted lymphocyte homeostasis in hepatitis‐associated acquired aplastic anemia is associated with short telomeres

Science.gov (United States)

Babushok, Daria V.; Grignon, Anne‐Laure; Li, Yimei; Atienza, Jamie; Xie, Hongbo M.; Lam, Ho‐Sun; Hartung, Helge; Bessler, Monica

2016-01-01

Hepatitis‐associated aplastic anemia (HAA) is a variant of acquired aplastic anemia (AA) in which immune‐mediated bone marrow failure (BMF) develops following an acute episode of seronegative hepatitis. Dyskeratosis congenita (DC) is an inherited BMF syndrome characterized by the presence of short telomeres, mucocutaneous abnormalities, and cancer predisposition. While both conditions may cause BMF and hepatic impairment, therapeutic approaches are distinct, making it imperative to establish the correct diagnosis. In clinical practice, lymphocyte telomere lengths (TL) are used as a first‐line screen to rule out inherited telomeropathies before initiating treatment for AA. To evaluate the reliability of TL in the HAA population, we performed a retrospective analysis of TL in 10 consecutively enrolled HAA patients compared to 19 patients with idiopathic AA (IAA). HAA patients had significantly shorter telomeres than IAA patients (P = 0.009), including four patients with TL at or below the 1st percentile for age‐matched controls. HAA patients had no clinical features of DC and did not carry disease‐causing mutations in known genes associated with inherited telomere disorders. Instead, short TLs were significantly correlated with severe lymphopenia and skewed lymphocyte subsets, features characteristic of HAA. Our results indicate the importance of caution in the interpretation of TL measurements in HAA, because, in this patient population, short telomeres have limited specificity. Am. J. Hematol. 91:243–247, 2016. © 2015 The Authors. American Journal of Hematology Published by Wiley Periodicals, Inc. PMID:26615915

Fanconi anemia founder mutation in Macedonian patients.

Science.gov (United States)

Madjunkova, Svetlana; Kocheva, Svetlana A; Plaseska-Karanfilska, Dijana

2014-01-01

Fanconi anemia (FA) is a rare autosomal recessive disorder clinically characterized by developmental abnormalities, progressive bone marrow failure (BMF) and profound cancer predisposition. Approximately 65% of all affected individuals have mutation in the FANCA (Fanconi anemia complementation group A) gene. The mutation spectrum of the FANCA gene is highly heterogeneous. FA-A is usually associated with private FANCA mutations in individual families. We describe 3 unrelated patients with FA with a similar clinical presentation: BMF, renal anomalies and café-au-lait pigmentation without major skeletal abnormality. The molecular analysis of the FANCA gene using the FA MLPA kit P031-A2/P032 FANCA, showed homozygous deletion of exon 3 in all 3 patients. Molecular analysis of the flanking regions of exon 3 precisely defined unique deletion of 2,040 bp and duplication of C (1788_3828dupC). These are the first 3 patients homozygous for deletion of FANCA exon 3 described to date. Although not related, the patients originated from the same Gypsy-like ethnic population. We conclude that c.190-256_283 + 1680del2040 dupC mutation in the FANCA gene is a founder mutation in Macedonian FA patients of Gypsy-like ethnic origin. Our finding has very strong implications for these patients in formulating diagnostic and carrier-screening strategy for BMF and FA and to enable comprehensive genetic counseling. © 2013 S. Karger AG, Basel.

Recent discoveries in the molecular pathogenesis of the inherited bone marrow failure syndrome Fanconi anemia.

Science.gov (United States)

Mamrak, Nicholas E; Shimamura, Akiko; Howlett, Niall G

2017-05-01

Fanconi anemia (FA) is a rare autosomal and X-linked genetic disease characterized by congenital abnormalities, progressive bone marrow failure (BMF), and increased cancer risk during early adulthood. The median lifespan for FA patients is approximately 33years. The proteins encoded by the FA genes function together in the FA-BRCA pathway to repair DNA damage and to maintain genome stability. Within the past two years, five new FA genes have been identified-RAD51/FANCR, BRCA1/FANCS, UBE2T/FANCT, XRCC2/FANCU, and REV7/FANCV-bringing the total number of disease-causing genes to 21. This review summarizes the discovery of these new FA genes and describes how these proteins integrate into the FA-BRCA pathway to maintain genome stability and critically prevent early-onset BMF and cancer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Seasonal variation in accumulation of persistent organic pollutants in an Arctic marine benthic food web

Energy Technology Data Exchange (ETDEWEB)

Evenset, A., E-mail: anita.evenset@akvaplan.niva.no [Akvaplan-niva. Fram Centre, Tromsø (Norway); University of Tromsø, The Arctic University of Norway, Tromsø (Norway); Hallanger, I.G. [University of Tromsø, The Arctic University of Norway, Tromsø (Norway); Tessmann, M. [Akvaplan-niva. Fram Centre, Tromsø (Norway); Institute for Hydrobiology and Fisheries Research, University of Hamburg (Germany); Warner, N. [Norwegian Institute for Air Research, Fram Centre, Tromsø (Norway); Ruus, A. [Norwegian Institute for Water Research, Oslo (Norway); Borgå, K. [Norwegian Institute for Water Research, Oslo (Norway); Department of Biosciences, P.O. Box 1066, Blindern 0316, Oslo (Norway); Gabrielsen, G.W. [Norwegian Polar Institute, Fram Centre, Tromsø (Norway); Christensen, G. [Akvaplan-niva. Fram Centre, Tromsø (Norway); Renaud, P.E. [Akvaplan-niva. Fram Centre, Tromsø (Norway); University Centre in Svalbard, Longyearbyen (Norway)

2016-01-15

The aim of the present study was to investigate seasonal variation in persistent organic pollutant (POP) concentrations, as well as food-web biomagnification, in an Arctic, benthic marine community. Macrozoobenthos, demersal fish and common eiders were collected both inside and outside of Kongsfjorden, Svalbard, during May, July and October 2007. The samples were analysed for a selection of legacy chlorinated POPs. Overall, low levels of POPs were measured in all samples. Although POP levels and accumulation patterns showed some seasonal variation, the magnitude and direction of change was not consistent among species. Overall, seasonality in bioaccumulation in benthic biota was less pronounced than in the pelagic system in Kongsfjorden. In addition, the results indicate that δ{sup 15}N is not a good predictor for POP-levels in benthic food chains. Other factors, such as feeding strategy (omnivory, necrophagy versus herbivory), degree of contact with the sediment, and a high dependence on particulate organic matter (POM), with low POP-levels and high δ{sup 15}N-values (due to bacterial isotope enrichment), seem to govern the uptake of the different POPs and result in loads deviating from what would be expected consulting the trophic position alone. - Highlights: • Seasonal variation in POP biomagnification was investigated in a benthic food web. • Levels of POPs are generally low in benthic species from Kongsfjorden, Svalbard. • POP-concentrations varied with season, but direction of change varied among taxa. • No POP-biomagnification, except for cis-nonachlor, was detected in this study. • δ{sup 15}N-values does not seem to be a good proxy for trophic level in macrozoobenthos.

Seasonal variation in accumulation of persistent organic pollutants in an Arctic marine benthic food web

International Nuclear Information System (INIS)

Evenset, A.; Hallanger, I.G.; Tessmann, M.; Warner, N.; Ruus, A.; Borgå, K.; Gabrielsen, G.W.; Christensen, G.; Renaud, P.E.

2016-01-01

The aim of the present study was to investigate seasonal variation in persistent organic pollutant (POP) concentrations, as well as food-web biomagnification, in an Arctic, benthic marine community. Macrozoobenthos, demersal fish and common eiders were collected both inside and outside of Kongsfjorden, Svalbard, during May, July and October 2007. The samples were analysed for a selection of legacy chlorinated POPs. Overall, low levels of POPs were measured in all samples. Although POP levels and accumulation patterns showed some seasonal variation, the magnitude and direction of change was not consistent among species. Overall, seasonality in bioaccumulation in benthic biota was less pronounced than in the pelagic system in Kongsfjorden. In addition, the results indicate that δ"1"5N is not a good predictor for POP-levels in benthic food chains. Other factors, such as feeding strategy (omnivory, necrophagy versus herbivory), degree of contact with the sediment, and a high dependence on particulate organic matter (POM), with low POP-levels and high δ"1"5N-values (due to bacterial isotope enrichment), seem to govern the uptake of the different POPs and result in loads deviating from what would be expected consulting the trophic position alone. - Highlights: • Seasonal variation in POP biomagnification was investigated in a benthic food web. • Levels of POPs are generally low in benthic species from Kongsfjorden, Svalbard. • POP-concentrations varied with season, but direction of change varied among taxa. • No POP-biomagnification, except for cis-nonachlor, was detected in this study. • δ"1"5N-values does not seem to be a good proxy for trophic level in macrozoobenthos.

Trophic transfer potential of two different crystalline phases of TiO2 NPs from Chlorella sp. to Ceriodaphnia dubia.

Science.gov (United States)

Iswarya, V; Bhuvaneshwari, M; Chandrasekaran, N; Mukherjee, Amitava

2018-04-01

Owing to the increase in the usage of titanium dioxide nanoparticles (TiO 2 NPs), their release into the aquatic environment is inevitable. In the aquatic ecosystem, TiO 2 NPs can bio-magnify at various trophic levels in the food chain through dietary exposure. In the current study, the trophic transfer potential of two crystalline phases of TiO 2, anatase and rutile nanoparticles (individual as well as a binary mixture) has been evaluated in the lake water matrix using algae-daphnia system. Chlorella sp. and Ceriodaphnia dubia were used as test organisms to represent the algae-daphnia food chain of the freshwater ecosystem. Other than crystallinity, the effect of irradiation (visible and UV-A) was also investigated at the test concentrations, 75, 300, and 1200 μM. TiO 2 NPs treated algal diet produced significant mortality only at the test concentrations, 300 and 1200 μM. The type of irradiation and crystallinity doesn't have any impact on the mortality of daphnids through the dietary exposure of TiO 2 NPs. Comparing the mixture with individual NPs, binary mixture induced less mortality on C. dubia which signifies the antagonistic effect of NPs when they coexist. Statistical modeling confirmed the antagonistic effect of the binary mixture on C. dubia. As individual NPs, anatase and rutile forms showed a maximum Ti accumulation under UV-A and visible irradiation, respectively. BMF of TiO 2 NPs has been in validation with the bioaccumulation noted in C. dubia. Individual NPs (75 μM) showed higher BMF value of ∼23 under both UV-A (anatase) and visible (rutile) irradiation. Individual NPs showing higher BMF confirmed their trophic transfer potential in the aquatic food chain, primarily through the diet. In contrast, the binary mixture obtained a higher BMF of 1.9 and 0.79 at 75 and 300 μM under visible and UV-A irradiation, respectively. The plausible reason behind this decrement was the antagonistic effect of the mixture which significantly reduced

KringloopToets: sluiten van de nutriëntenkringloop op het niveau van Noordwest-Europa

NARCIS (Netherlands)

Leenstra, Ferry; Vellinga, Theun; Bremmer, Bart

2017-01-01

The Nutrient Cycle Assessment aims at visualizing nutrient flows. In policy documents closing of nutrient cycles at the level of North Western Europe is often mentioned. Province North Brabant, farmers organisation ZLTO and NGO BMF examined together with Wageningen University & Research the

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

Bioaccumulation of 14C-Labeled Graphene in an Aquatic Food Chain through Direct Uptake or Trophic Transfer.

Science.gov (United States)

Dong, Shipeng; Xia, Tian; Yang, Yu; Lin, Sijie; Mao, Liang

2018-01-16

The growing applications of graphene materials warrant a careful evaluation of their environmental fate in aquatic food webs. Escherichia coli (Bacteria), Tetrahymena thermophila (protozoa), Daphnia magna (zooplankton), and Danio rerio (vertebrate) were used to build aquatic food chains to investigate the waterborne uptake and trophic transfer of 14 C-labeled graphene. Body burden factor (BBF) and trophic transfer factor (TTF) were analyzed for each organism and food chain to assess the bioaccumulation and biomagnification of graphene. The test organisms have high potential of accumulating graphene via direct uptake from culture medium with log-transformed BBF (log BBF) values of 3.66, 5.1, 3.9, and 1.62 for each organism, respectively. In the food chain from E. coli to T. thermophila, the calculated TTFs of 0.2 to 8.6 indicate the high trophic transfer potential in this aquatic food chain. However, the TTFs calculated for the food chain from T. thermophila to D. magna and from D. magna to D. rerio are much lower than 1, indicating that biomagnification was unlikely to occur in these food chains. Body burden measured for dietary uptake by T. thermophila, D. magna, and D. rerio are higher than that via waterborne exposure in a similar nominal concentration, respectively, indicating that trophic transfer is a nonnegligible route for the bioaccumulation of graphene in organisms.

75 FR 10471 - Privacy Act of 1974; System of Records

Science.gov (United States)

2010-03-08

... (DNSP), Defense Reutilization and Marketing Service, DRMS-BBS, 74 Washington Avenue North, Battle Creek... Program (DNSP), and the Bidder Master File (BMF): Defense Reutilization and Marketing Service, ATTN: Chief..., amounts paid, owed or refunded, data on bad checks, bid bond data, and bank guarantee code. AUTHORITY FOR...

Trophic transfer of persistent organochlorine contaminants (OCs) within an Arctic marine food web from the southern Beaufort-Chukchi Seas

International Nuclear Information System (INIS)

Hoekstra, P.F.; O'Hara, T.M.; Fisk, A.T.; Borgaa, K.; Solomon, K.R.; Muir, D.C.G.

2003-01-01

The trophic status and biomagnification of persistent OCs within the near-shore Beaufort-Chukchi Seas food web from Barrow, AK is discussed. - Stable isotope values (δ 13 C, δ 15 N) and concentrations of persistent organochlorine contaminants (OCs) were determined to evaluate the near-shore marine trophic status of biota and biomagnification of OCs from the southern Beaufort-Chukchi Seas (1999-2000) near Barrow, AK. The biota examined included zooplankton (Calanus spp.), fish species such as arctic cod (Boreogadus saida), arctic char (Salvelinus alpinus), pink salmon (Oncorhynchus gorbuscha), and fourhorn sculpin (Myoxocephalus quadricornis), along with marine mammals, including bowhead whales (Balaena mysticetus), beluga whales (Delphinapterus leucas), ringed seals (Phoca hispida) and bearded seals (Erignathus barbatus). The isotopically derived trophic position of biota from the Beaufort-Chukchi Seas marine food web, avian fauna excluded, is similar to other coastal food webs in the Arctic. Concentrations of OCs in marine mammals were significantly greater than in fish and corresponded with determined trophic level. In general, OCs with the greatest food web magnification factors (FWMFs) were those either formed due to biotransformation (e.g. p,p'-DDE, oxychlordane) or considered recalcitrant (e.g. β-HCH, 2,4,5-Cl substituted PCBs) in most biota, whereas concentrations of OCs that are considered to be readily eliminated (e.g. γ-HCH) did not correlate with trophic level. Differences in physical-chemical properties of OCs, feeding strategy and possible biotransformation were reflected in the variable biomagnification between fish and marine mammals. The FWMFs in the Beaufort-Chukchi Seas region were consistent with reported values in the Canadian Arctic and temperate food webs, but were statistically different than FWMFs from the Barents and White Seas, indicating that the spatial variability of OC contamination in top-level marine Arctic predators is

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).

Automated Analysis of Vital Signs Identified Patients with Substantial Bleeding Prior to Hospital Arrival

Science.gov (United States)

2015-10-01

2.1.3 Clinical Outcomes For the BMF dataset, a research nurse collected patient attributes and outcome data via retrospective chart review of...comparison, we also computed the proportion of patients with other hemodynamic abnormalities: initial SBP < 110 mmHg, any prehospital SBP < 90 mmHg, or any

Biomarker responses of Peromyscus leucopus exposed to lead and cadmium in the Southeast Missouri Lead Mining District.

Science.gov (United States)

Beyer, W Nelson; Casteel, Stan W; Friedrichs, Kristen R; Gramlich, Eric; Houseright, Ruth A; Nichols, John R; Karouna-Renier, Natalie K; Kim, Dae Young; Rangen, Kathleen L; Rattner, Barnett A; Schultz, Sandra L

2018-01-29

Biomarker responses and histopathological lesions have been documented in laboratory mammals exposed to elevated concentrations of lead and cadmium. The exposure of white-footed mice (Peromyscus leucopus) to these metals and the potential associated toxic effects were examined at three contaminated sites in the Southeast Missouri Lead Mining District and at a reference site in MO, USA. Mice from the contaminated sites showed evidence of oxidative stress and reduced activity of red blood cell δ-aminolevulinic acid dehydratase (ALAD). Histological examinations of the liver and kidney, cytologic examination of blood smears, and biomarkers of lipid peroxidation and DNA damage failed to show indications of toxic effects from lead. The biomagnification factor of cadmium (hepatic concentration/soil concentration) at a site with a strongly acid soil was 44 times the average of the biomagnification factors at two sites with slightly alkaline soils. The elevated concentrations of cadmium in the mice did not cause observable toxicity, but were associated with about a 50% decrease in expected tissue lead concentrations and greater ALAD activity compared to the activity at the reference site. Lead was associated with a decrease in concentrations of hepatic glutathione and thiols, whereas cadmium was associated with an increase. In addition, to support risk assessment efforts, we developed linear regression models relating both tissue lead dosages (based on a previously published a laboratory study) and tissue lead concentrations in Peromyscus to soil lead concentrations.

Biomarker responses of Peromyscus leucopus exposed to lead and cadmium in the Southeast Missouri Lead Mining District

Science.gov (United States)

Beyer, W. Nelson; Casteel, Stan W.; Friedrichs, Kristen R.; Gramlich, Eric; Houseright, Ruth A.; Nichols, John W.; Karouna-Renier, Natalie; Kim, Dae Young; Rangen, Kathleen; Rattner, Barnett A.; Schultz, Sandra

2018-01-01

Biomarker responses and histopathological lesions have been documented in laboratory mammals exposed to elevated concentrations of lead and cadmium. The exposure of white-footed mice (Peromyscus leucopus) to these metals and the potential associated toxic effects were examined at three contaminated sites in the Southeast Missouri Lead Mining District and at a reference site in MO, USA. Mice from the contaminated sites showed evidence of oxidative stress and reduced activity of red blood cell δ-aminolevulinic acid dehydratase (ALAD). Histological examinations of the liver and kidney, cytologic examination of blood smears, and biomarkers of lipid peroxidation and DNA damage failed to show indications of toxic effects from lead. The biomagnification factor of cadmium (hepatic concentration/soil concentration) at a site with a strongly acid soil was 44 times the average of the biomagnification factors at two sites with slightly alkaline soils. The elevated concentrations of cadmium in the mice did not cause observable toxicity, but were associated with about a 50% decrease in expected tissue lead concentrations and greater ALAD activity compared to the activity at the reference site. Lead was associated with a decrease in concentrations of hepatic glutathione and thiols, whereas cadmium was associated with an increase. In addition, to support risk assessment efforts, we developed linear regression models relating both tissue lead dosages (based on a previously published a laboratory study) and tissue lead concentrations in Peromyscus to soil lead concentrations.

Contrasting Food Web Factor and Body Size Relationships with Hg and Se Concentrations in Marine Biota

Science.gov (United States)

Karimi, Roxanne; Frisk, Michael; Fisher, Nicholas S.

2013-01-01

Marine fish and shellfish are primary sources of human exposure to mercury, a potentially toxic metal, and selenium, an essential element that may protect against mercury bioaccumulation and toxicity. Yet we lack a thorough understanding of Hg and Se patterns in common marine taxa, particularly those that are commercially important, and how food web and body size factors differ in their influence on Hg and Se patterns. We compared Hg and Se content among marine fish and invertebrate taxa collected from Long Island, NY, and examined associations between Hg, Se, body length, trophic level (measured by δ15N) and degree of pelagic feeding (measured by δ13C). Finfish, particularly shark, had high Hg content whereas bivalves generally had high Se content. Both taxonomic differences and variability were larger for Hg than Se, and Hg content explained most of the variation in Hg:Se molar ratios among taxa. Finally, Hg was more strongly associated with length and trophic level across taxa than Se, consistent with a greater degree of Hg bioaccumulation in the body over time, and biomagnification through the food web, respectively. Overall, our findings indicate distinct taxonomic and ecological Hg and Se patterns in commercially important marine biota, and these patterns have nutritional and toxicological implications for seafood-consuming wildlife and humans. PMID:24019976

Contrasting food web factor and body size relationships with Hg and Se concentrations in marine biota.

Directory of Open Access Journals (Sweden)

Roxanne Karimi

Full Text Available Marine fish and shellfish are primary sources of human exposure to mercury, a potentially toxic metal, and selenium, an essential element that may protect against mercury bioaccumulation and toxicity. Yet we lack a thorough understanding of Hg and Se patterns in common marine taxa, particularly those that are commercially important, and how food web and body size factors differ in their influence on Hg and Se patterns. We compared Hg and Se content among marine fish and invertebrate taxa collected from Long Island, NY, and examined associations between Hg, Se, body length, trophic level (measured by δ(15N and degree of pelagic feeding (measured by δ(13C. Finfish, particularly shark, had high Hg content whereas bivalves generally had high Se content. Both taxonomic differences and variability were larger for Hg than Se, and Hg content explained most of the variation in Hg:Se molar ratios among taxa. Finally, Hg was more strongly associated with length and trophic level across taxa than Se, consistent with a greater degree of Hg bioaccumulation in the body over time, and biomagnification through the food web, respectively. Overall, our findings indicate distinct taxonomic and ecological Hg and Se patterns in commercially important marine biota, and these patterns have nutritional and toxicological implications for seafood-consuming wildlife and humans.

The role of bioaccumulation in migration of technogenic radionuclides in freshwater ecosystem

International Nuclear Information System (INIS)

Petkeviciute, D.

1999-01-01

The concentrations of 137 Cs, 60 Co and 54 Mn were estimated in bottom sediments and different species of macrophyte as well as fish of Lake Druksiai, the cooling basin for the Ignalina NPP. Besides, the concentration factors for radionuclides were calculated in sediments and macrophyte. The results suggested that macrophyte accumulated radionuclides from water more than from bottom sediments. The 'trophic level effect' (bio-magnification) was found for 137 Cs accumulation in fish, while as for 60 Co and 54 Mn that effect did not occur. (au)

Uptake of Cadmium, Copper, Lead, and Zinc from Sediments by an Aquatic Macrophyte and by Terrestrial Arthropods in a Freshwater Wetland Ecosystem.

Science.gov (United States)

Kim, Heung-Tae; Kim, Jae Geun

2016-08-01

The objective of this study was to investigate trace-metal [cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn)] biotransference and biomagnification in terrestrial biota at different trophic levels (primary producer-top predator) of a wetland ecosystem. We investigated whether metal concentrations in the sediment are reflected in terrestrial arthropods and aquatic plants. We sampled the floating-leaved plant Trapa japonica; its species-specific primary consumer, the leaf beetle Galerucella nipponensis; and two predatory arthropods (the water strider Gerris sp. and the wolf spider Arctosa sp.) from three wetlands with different sedimentary metal concentrations. The δ(13)C and δ(15)N signatures in the trophic link between the plants and the leaf beetles supported the specificity of their feeding relationship. The stable isotope signatures indicate that the leaf beetle could be an important link in the trophic transfer of the metals. Transference factors (TFs) were 1 for all biota, and the concentrations were positively correlated with the trophic levels. Thus, there may be Cu and Zn biomagnification in the arthropods. We noted TF 1 among the arthropods. Therefore, Cd is probably not biomagnified between T. japonica and G. nipponensis, but it might be biomagnified in the arthropods. The metal burden in terrestrial arthropods may also be influenced by uptake from the sediment by aquatic plants.

Análise do nível de adesão ao disclosure do risco de mercado pelos bancos com ações negociadas na BM&FBOVESPA

Directory of Open Access Journals (Sweden)

Vinícius Costa da Silva Zonatto

2015-05-01

Full Text Available O objetivo deste estudo é analisar o nível de adesão ao disclosure do risco de mercado pelas instituições financeiras com ações negociadas na Bolsa de Valores, Mercadorias e Futuros (BM&F Bovespa, no tocante às recomendações do Acordo de Basileia II, em especial pelos bancos listados nos Níveis Diferenciados de Governança Corporativa da BM&F Bovespa. A metodologia utilizada na pesquisa consistiu num estudo descritivo, realizado por meio de uma pesquisa documental, com abordagem quantitativa dos dados. Os dados foram analisados por meio de consulta aos demonstrativos financeiros padronizados de 2010, disponibilizados por 24 bancos no sitio da BM&F Bovespa. Para tratar os dados foram utilizados o teste de Kolmogorov-Smirnov e o teste não-paramétrico de Mann-Whitney. A análise dos dados permitiu identificar os fatores que evidenciam o grau de transparência das informações relacionadas ao risco de mercado que se tornam necessárias para a tomada de decisão dos stakeholders dessas organizações. Os resultados encontrados indicam que instituições participantes de diferentes níveis de governança corporativa apresentam maior adesão às recomendações do Novo Acordo de Basileia para o disclosure do risco de mercado, do que as instituições participantes do mercado tradicional. No entanto, a partir da aplicação do teste não-paramétrico de Mann-Whitney, verificou-se que as práticas de disclosure das organizações em estudo não possuem diferenças estatisticamente significativas.

A landscape of germ line mutations in a cohort of inherited bone marrow failure patients.

Science.gov (United States)

Bluteau, Olivier; Sebert, Marie; Leblanc, Thierry; Peffault de Latour, Régis; Quentin, Samuel; Lainey, Elodie; Hernandez, Lucie; Dalle, Jean-Hugues; Sicre de Fontbrune, Flore; Lengline, Etienne; Itzykson, Raphael; Clappier, Emmanuelle; Boissel, Nicolas; Vasquez, Nadia; Da Costa, Mélanie; Masliah-Planchon, Julien; Cuccuini, Wendy; Raimbault, Anna; De Jaegere, Louis; Adès, Lionel; Fenaux, Pierre; Maury, Sébastien; Schmitt, Claudine; Muller, Marc; Domenech, Carine; Blin, Nicolas; Bruno, Bénédicte; Pellier, Isabelle; Hunault, Mathilde; Blanche, Stéphane; Petit, Arnaud; Leverger, Guy; Michel, Gérard; Bertrand, Yves; Baruchel, André; Socié, Gérard; Soulier, Jean

2018-02-15

Bone marrow (BM) failure (BMF) in children and young adults is often suspected to be inherited, but in many cases diagnosis remains uncertain. We studied a cohort of 179 patients (from 173 families) with BMF of suspected inherited origin but unresolved diagnosis after medical evaluation and Fanconi anemia exclusion. All patients had cytopenias, and 12.0% presented ≥5% BM blast cells. Median age at genetic evaluation was 11 years; 20.7% of patients were aged ≤2 years and 36.9% were ≥18 years. We analyzed genomic DNA from skin fibroblasts using whole-exome sequencing, and were able to assign a causal or likely causal germ line mutation in 86 patients (48.0%), involving a total of 28 genes. These included genes in familial hematopoietic disorders ( GATA2 , RUNX1 ), telomeropathies ( TERC , TERT , RTEL1 ), ribosome disorders ( SBDS , DNAJC21 , RPL5 ), and DNA repair deficiency ( LIG4 ). Many patients had an atypical presentation, and the mutated gene was often not clinically suspected. We also found mutations in genes seldom reported in inherited BMF (IBMF), such as SAMD9 and SAMD9L (N = 16 of the 86 patients, 18.6%), MECOM/EVI1 (N = 6, 7.0%), and ERCC6L2 (N = 7, 8.1%), each of which was associated with a distinct natural history; SAMD9 and SAMD9L patients often experienced transient aplasia and monosomy 7, whereas MECOM patients presented early-onset severe aplastic anemia, and ERCC6L2 patients, mild pancytopenia with myelodysplasia. This study broadens the molecular and clinical portrait of IBMF syndromes and sheds light on newly recognized disease entities. Using a high-throughput sequencing screen to implement precision medicine at diagnosis can improve patient management and family counseling. © 2018 by The American Society of Hematology.

MERCADO FUTURO DE CAFÉ : UM ESTUDO DE CASO.

Directory of Open Access Journals (Sweden)

TÁCITO AUGUSTO FARIAS

2014-08-01

Full Text Available Resumo: O café é a commodity agrícola brasileira que possui o mercado mais desenvolvido, dentre os contratos negociados na Bolsa de Mercadorias e Futuros (BM&F é o que apresenta negociações em maior volume, além de apresentar maiores volatilidades, tornando as operações de hedge uma importante ferramenta para diminuição de riscos para quem participa desse mercado. Realizando o hedge, o produtor acaba eliminando totalmente o risco de variação do preço só que passa a lidar o risco de variação de base. Deste modo, objetivou-se identificar o modelo mais adequado à análise do risco de base do café por meio dos índices Esalq e BM&F Os resultados empíricos sugerem a necessidade de modelagem da série pelo modelo ARIMA (Autorregressivo – Integrado – Média Móvel. Também foram utilizados os resultados da estatística U-Theil, que apresentam bons indicadores para fins de previsão.

Nanofluidic Transistor Circuits

Science.gov (United States)

Chang, Hsueh-Chia; Cheng, Li-Jing; Yan, Yu; Slouka, Zdenek; Senapati, Satyajyoti

2012-02-01

Non-equilibrium ion/fluid transport physics across on-chip membranes/nanopores is used to construct rectifying, hysteretic, oscillatory, excitatory and inhibitory nanofluidic elements. Analogs to linear resistors, capacitors, inductors and constant-phase elements were reported earlier (Chang and Yossifon, BMF 2009). Nonlinear rectifier is designed by introducing intra-membrane conductivity gradient and by asymmetric external depletion with a reverse rectification (Yossifon and Chang, PRL, PRE, Europhys Lett 2009-2011). Gating phenomenon is introduced by functionalizing polyelectrolytes whose conformation is field/pH sensitive (Wang, Chang and Zhu, Macromolecules 2010). Surface ion depletion can drive Rubinstein's microvortex instability (Chang, Yossifon and Demekhin, Annual Rev of Fluid Mech, 2012) or Onsager-Wien's water dissociation phenomenon, leading to two distinct overlimiting I-V features. Bipolar membranes exhibit an S-hysteresis due to water dissociation (Cheng and Chang, BMF 2011). Coupling the hysteretic diode with some linear elements result in autonomous ion current oscillations, which undergo classical transitions to chaos. Our integrated nanofluidic circuits are used for molecular sensing, protein separation/concentration, electrospray etc.

A blood-mimicking fluid for particle image velocimetry with silicone vascular models

Science.gov (United States)

Yousif, Majid Y.; Holdsworth, David W.; Poepping, Tamie L.

2011-03-01

For accurate particle image velocimetry measurements in hemodynamics studies, it is important to use a fluid with a refractive index ( n) matching that of the vascular models (phantoms) and ideally a dynamic viscosity matching human blood. In this work, a blood-mimicking fluid (BMF) composed of water, glycerol, and sodium iodide was formulated for a range of refractive indices to match most common silicone elastomers ( n = 1.40-1.43) and with corresponding dynamic viscosity within the average cited range of healthy human blood (4.4 ± 0.5 cP). Both refractive index and viscosity were attained at room temperature (22.2 ± 0.2°C), which eliminates the need for a temperature-control system. An optimally matched BMF, suitable for use in a vascular phantom ( n = 1.4140 ± 0.0008, Sylgard 184), was demonstrated with composition (by weight) of 47.38% water, 36.94% glycerol (44:56 glycerol-water ratio), and 15.68% sodium iodide salt, resulting in a dynamic viscosity of 4 .31 ± 0 .03 cP.

Firmware development and testing of the ATLAS IBL Back-Of-Crate card

CERN Document Server

Stramaglia, ME; The ATLAS collaboration

2014-01-01

ATLAS is one of the four big LHC experiments and currently its Pixel-Detector is being upgraded with a new innermost 4th layer, the Insertable B-Layer (IBL). The upgrade will result in better tracking efficiency and compensate radiation damages of the Pixel-Detector. Newly developed front-end electronics and the higher than originally planned LHC luminosity will require a complete re-design of the Off-Detector-Electronics consisting of the Back-Of-Crate card (BOC) and the Read-Out-Driver (ROD). The main purpose of the BOC card is the distribution of the LHC clock to all Pixel-Detector components as well as interfacing the detector and the higher-level-readout optically. It is equipped with three Xilinx Spartan-6 FPGAs, one BOC Control FPGA (BCF) and two BOC Main FPGAs (BMF). The BMF are responsible for the signal processing of all incoming and outgoing data. The data-path to the detector is running a 40 MHz bi-phase-mark encoded stream. This stream is delayed by a fine delay block using Spartan-6 IODELAY prim...

Radioecological studies in marine ecosystems

International Nuclear Information System (INIS)

Kellermann, H.J.; Kanisch, G.

1999-01-01

The bioconcentration factor shows the ratio between concentration of a substance in water or in fish. It is a calculation quantity, used for assessing the possible concentration in fish in proportion to the known concentration in water. Although the element cesium discussed in this report is primarily ingested via the food chain (biomagnification) and not via direct uptake through the gills, but the bioconcentration factor model is nevertheless applicable, because there is a relation between the element's concentration in water and in food. One has to consider, however, the influence on cesium uptake through the quantity of food and species-dependent accumulation. Experimental results obtained for various ecosystems are reported and illustrate the mechanisms involved. (orig./CB) [de

A Biochemical Approach to Understanding the Fanconi Anemia Pathway-Regulated Nucleases in Genome Maintenance for Preventing Bone Marrow Failure and Cancer

Science.gov (United States)

2014-04-01

the Fanconi Anemia Pathway- Regulated Nucleases in Genome Maintenance for Preventing Bone Marrow Failure and Cancer PRINCIPAL INVESTIGATOR...GRANT NUMBER 4. TITLE AND SUBTITLE A Biochemical Approach to Understanding the Fanconi Anemia Pathway-Regulated Nucleases in Genome Maintenance for...Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Fanconi anemia is the most prevalent inherited BMF syndromes, caused by mutations in

Oligotrophy as a major driver of mercury bioaccumulation in medium-to high-trophic level consumers: A marine ecosystem-comparative study.

Science.gov (United States)

Chouvelon, Tiphaine; Cresson, Pierre; Bouchoucha, Marc; Brach-Papa, Christophe; Bustamante, Paco; Crochet, Sylvette; Marco-Miralles, Françoise; Thomas, Bastien; Knoery, Joël

2018-02-01

Mercury (Hg) is a global contaminant of environmental concern. Numerous factors influencing its bioaccumulation in marine organisms have already been described at both individual and species levels (e.g., size or age, habitat, trophic level). However, few studies have compared the trophic characteristics of ecosystems to explain underlying mechanisms of differences in Hg bioaccumulation and biomagnification among food webs and systems. The present study aimed at investigating the potential primary role of the trophic status of systems on Hg bioaccumulation and biomagnification in temperate marine food webs, as shown by their medium-to high-trophic level consumers. It used data from samples collected at the shelf-edge (i.e. offshore organisms) in two contrasted ecosystems: the Bay of Biscay in the North-East Atlantic Ocean and the Gulf of Lion in the North-West Mediterranean Sea. Seven species including crustaceans, sharks and teleost fish, previously analysed for their total mercury (T-Hg) concentrations and their stable carbon and nitrogen isotope compositions, were considered for a meta-analysis. In addition, methylated mercury forms (or methyl-mercury, Me-Hg) were analysed. Mediterranean organisms presented systematically lower sizes than Atlantic ones, and lower δ 13 C and δ 15 N values, the latter values especially highlighting the more oligotrophic character of Mediterranean waters. Mediterranean individuals also showed significantly higher T-Hg and Me-Hg concentrations. Conversely, Me-Hg/T-Hg ratios were higher than 85% for all species, and quite similar between systems. Finally, the biomagnification power of Hg was different between systems when considering T-Hg, but not when considering Me-Hg, and was not different between the Hg forms within a given system. Overall, the different parameters showed the crucial role of the low primary productivity and its effects rippling through the compared ecosystems in the higher Hg bioaccumulation seen in organisms

Gap Junction Intercellular Communication in Bone Marrow Failure

Science.gov (United States)

2012-10-01

traits are responsible for the differences in the severity of these diseases and their relation to skeletal malformations in BMF syndromes. Using a...mesenchymal transition (19-29), and are crucial in the establishment of electrical synapses in the central nervous system, heart , immune system and...developmental defective osteogenesis resulting in craniofacial and skeletal anomalies and associated with heart defects and neurological defects. ODDD

A spatially-dynamic preliminary risk assessment of the American peregrine falcon at the Los Alamos National Laboratory (version 1)

International Nuclear Information System (INIS)

Gallegos, A.F.; Gonzales, G.J.; Bennett, K.D.

1997-06-01

The Endangered Species Act and the Record of Decision on the Dual Axis Radiographic Hydrodynamic Test Facility at the Los Alamos National Laboratory require protection of the American peregrine falcon. A preliminary risk assessment of the peregrine was performed using a custom FORTRAN model and a geographical information system. Estimated doses to the falcon were compared against toxicity reference values to generate hazard indices. Hazard index results indicated no unacceptable risk to the falcon from the soil ingestion pathway, including a measure of cumulative effects from multiple contaminants that assumes a linear additive toxicity type. Scaling home ranges on the basis of maximizing falcon height for viewing prey decreased estimated risk by 69% in a canyons-based home range and increased estimated risk by 40% in a river-based home range. Improving model realism by weighting simulated falcon foraging based on distance from potential nest sites decreased risk by 93% in one exposure unit and by 82% in a second exposure unit. It was demonstrated that choice of toxicity reference values can have a substantial impact on risk estimates. Adding bioaccumulation factors for several organics increased partial hazard quotients by a factor of 110, but increased the mean hazard index by only 0.02 units. Adding a food consumption exposure pathway in the form of biomagnification factors for 15 contaminants of potential ecological concern increased the mean hazard index to 1.16 (± 1.0), which is above the level of acceptability (1.0). Aroclor-1254, dichlorodiphenyltrichlorethane (DDT) and dichlorodiphenylethelyne (DDE) accounted for 81% of the estimated risk that includes soil ingestion and food consumption Contaminant pathways and a biomagnification component. Information on risk by specific geographical location was generated, which can be used to manage contaminated areas, falcon habitat, facility siting, and/or facility operations. 123 refs., 10 figs., 2 tabs

A spatially-dynamic preliminary risk assessment of the American peregrine falcon at the Los Alamos National Laboratory (version 1)

Energy Technology Data Exchange (ETDEWEB)

Gallegos, A.F.; Gonzales, G.J.; Bennett, K.D. [and others

1997-06-01

The Endangered Species Act and the Record of Decision on the Dual Axis Radiographic Hydrodynamic Test Facility at the Los Alamos National Laboratory require protection of the American peregrine falcon. A preliminary risk assessment of the peregrine was performed using a custom FORTRAN model and a geographical information system. Estimated doses to the falcon were compared against toxicity reference values to generate hazard indices. Hazard index results indicated no unacceptable risk to the falcon from the soil ingestion pathway, including a measure of cumulative effects from multiple contaminants that assumes a linear additive toxicity type. Scaling home ranges on the basis of maximizing falcon height for viewing prey decreased estimated risk by 69% in a canyons-based home range and increased estimated risk by 40% in a river-based home range. Improving model realism by weighting simulated falcon foraging based on distance from potential nest sites decreased risk by 93% in one exposure unit and by 82% in a second exposure unit. It was demonstrated that choice of toxicity reference values can have a substantial impact on risk estimates. Adding bioaccumulation factors for several organics increased partial hazard quotients by a factor of 110, but increased the mean hazard index by only 0.02 units. Adding a food consumption exposure pathway in the form of biomagnification factors for 15 contaminants of potential ecological concern increased the mean hazard index to 1.16 ({+-} 1.0), which is above the level of acceptability (1.0). Aroclor-1254, dichlorodiphenyltrichlorethane (DDT) and dichlorodiphenylethelyne (DDE) accounted for 81% of the estimated risk that includes soil ingestion and food consumption Contaminant pathways and a biomagnification component. Information on risk by specific geographical location was generated, which can be used to manage contaminated areas, falcon habitat, facility siting, and/or facility operations. 123 refs., 10 figs., 2 tabs.

Antibiotic Pollution in Marine Food Webs in Laizhou Bay, North China: Trophodynamics and Human Exposure Implication.

Science.gov (United States)

Liu, Sisi; Zhao, Hongxia; Lehmler, Hans-Joachim; Cai, Xiyun; Chen, Jingwen

2017-02-21

Little information is available about the bioaccumulation and biomagnification of antibiotics in marine food webs. Here, we investigate the levels and trophic transfer of 9 sulfonamide (SA), 5 fluoroquinolone (FQ), and 4 macrolide (ML) antibiotics, as well as trimethoprim in nine invertebrate and ten fish species collected from a marine food web in Laizhou Bay, North China in 2014 and 2015. All the antibiotics were detected in the marine organisms, with SAs and FQs being the most abundant antibiotics. Benthic fish accumulated more SAs than invertebrates and pelagic fish, while invertebrates exhibited higher FQ levels than fish. Generally, SAs and trimethoprim biomagnified in the food web, while the FQs and MLs were biodiluted. Trophic magnification factors (TMF) were 1.2-3.9 for SAs and trimethoprim, 0.3-1.0 for FQs and MLs. Limited biotransformation and relatively high assimilation efficiencies are the likely reasons for the biomagnification of SAs. The pH dependent distribution coefficients (log D) but not the lipophilicity (log K OW ) of SAs and FQs had a significant correlation (r = 0.73; p < 0.05) with their TMFs. Although the calculated estimated daily intakes (EDI) for antibiotics suggest that consumption of seafood from Laizhou Bay is not associated with significant human health risks, this study provides important insights into the guidance of risk management of antibiotics.

Conjugated linoleic acids content in M.longissimus dorsi of Hanwoo steers fed a concentrate supplemented with soybean oil, sodium bicarbonate-based monensin, fish oil.

Science.gov (United States)

Song, M K; Jin, G L; Ji, B J; Chang, S S; Jeong, J; Smith, S B; Choi, S H

2010-06-01

We hypothesized that increasing ruminal pH would lead to enrichment of adipose tissue with conjugated linoleic acid (CLA). Twenty-four Korean native (Hanwoo) steers were used to investigate the additive effects of monensin (30ppm, SO-BM) and/or fish oil (0.7%, SO-BMF) in the diets along with soybean oil (7%) and sodium bicarbonate (0.5%, SO-B) on cis-9, trans-11 and trans-10, cis-12 CLAs in adipose tissue. The steers were assigned to randomly four groups of six animals each based on body weight. The control group (CON) was fed a commercial concentrate for the late fattening stage. Supplementation of oil and sodium bicarbonate reduced feed intake and daily gain, and fish oil further decreased feed intake (P<0.001) and daily gain (P<0.087) compared to steers fed other diets. Total CLA and CLA isomers in M.longissimus dorsi were not affected when steers were fed SO-B and SO-BM diets compared with those of steers fed CON and SO-BMF diets. However, total poly unsaturated fatty acids were higher (P=0.03) in steers fed SO than in CON steers. Published by Elsevier Ltd.

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

Mercury bio magnification in the Atlantic spotted dolphin (Stenella frontalis) food chain, using nitrogen stable isotope as an ecological tracer

International Nuclear Information System (INIS)

Kehrig, Helena A; Baptista, Gilberto; Di Beneditto, Ana Paula M; Almeida, Marcelo G; Rezende, Carlos E; Siciliano, Salvatore; De Moura, Jailson F; Moreira, Isabel

2017-01-01

An assessment of mercury (Hg) concentrations and nitrogen stable isotope (δ"1"5N) was conducted in the food chain of the Atlantic spotted dolphin (Stenella frontalis), including phytoplankton, zooplankton, planktivorous fish and its major prey (predatory fish and a single species of cephalopod), that compose a tropical trophic chain of the Brazilian southeastern coast. Tissue concentrations of Hg in a voracious predator fish, the largehead hairtail (Trichiurus lepturus), one of the dolphin's prey, were 9.8 times lower than median concentrations found in dolphin tissues. δ"1"5N values in predatory fish were found to be lower to those of its predator the spotted dolphin. Isotopic data suggested significant differences for ? 15N along the trophic chain, with the top predator (dolphin) exhibiting heavier value, followed by the voracious predator fish and the benthonic carnivorous fish, the whitemouth croaker (Micropogonias furnieri). Phytoplankton displayed the lightest δ"1"5N, followed by zooplankton and the planktophagous fish, the lebranche mullet (Mugil liza). This fish species and the cephalopod showed the lowest median Hg concentration. All links of the entire trophic chain presented trophic transfer of Hg with a biomagnification factor higher than 1. A significant relationship was found between the log Hg concentration and trophic level (TL) of all evaluated species, with a positive slope (β= 0.87). The calculated trophic magnification factor (TMF7.44) indicates that Hg concentration increased per TL, and also that the entire coastal food chain from the South Atlantic Ocean presented a biomagnification power of Hg within a range previously reported for tropical coastal ecosystems. Key words: Marine mammal, coastal aquatic biota, toxic element, biotransference, ecological tracer

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 < 0.0001). The present study results improved our understanding on the environmental behavior and fate of SCCPs in aquatic ecosystem. Copyright © 2016 Elsevier Ltd. All rights

Occurrence, bioaccumulation and long-range transport of short-chain chlorinated paraffins on the Fildes Peninsula at King George Island, Antarctica.

Science.gov (United States)

Li, Huijuan; Fu, Jianjie; Zhang, Aiqian; Zhang, Qinghua; Wang, Yawei

2016-09-01

As a candidate persistent organic pollutant of the Stockholm Convention, short-chain chlorinated paraffins (SCCPs) have recently received particular attention. In this study, we investigated, for the first time, the concentrations of SCCPs in biota samples collected from the Fildes Peninsula at King George Island and Ardley Island, Antarctica. The concentrations of SCCPs ranged from 3.5 to 256.6ng/g (dry weight, dw), with a mean of 76.6±61.8ng/g dw, which was lower than those detected in mid- and low-latitude regions. The long-range transport behaviour of SCCPs was confirmed by both the detection of SCCPs in Antarctic remote areas and their special congener profiles. Short carbon chain (C10) congeners predominated in the Antarctic samples, which accounted for 56.1% of the total SCCP contamination. Such enrichment of C10 congeners indicated the high potential for the long-range transport of shorter chain congeners. In addition, SCCPs tended to be enriched in the species with high lipid contents. The biomagnification potential of SCCPs was found between Archeogastropoda (Agas) and Neogastropoda (Ngas), and the biomagnification factors of shorter chain congeners of SCCPs were higher than that of the longer chain ones. Considering that the endemic species in polar regions may be sensitive and vulnerable to the adverse effects of environmental contaminants, more attention should be paid on the bioaccumulation and toxicological risks of SCCPs in polar environments. Copyright © 2016. Published by Elsevier Ltd.

Stem cell collection and gene transfer in Fanconi anemia.

Science.gov (United States)

Kelly, Patrick F; Radtke, Susan; von Kalle, Christof; Balcik, Brenden; Bohn, Kimberley; Mueller, Robin; Schuesler, Todd; Haren, Moira; Reeves, Lilith; Cancelas, Jose A; Leemhuis, Thomas; Harris, Richard; Auerbach, Arleen D; Smith, Franklin O; Davies, Stella M; Williams, David A

2007-01-01

Fanconi anemia (FA) is a rare genetic syndrome characterized by progressive bone marrow failure (BMF), congenital anomalies, and a predisposition to malignancy. Successful gene transfer into hematopoietic stem cells (HSCs) could reverse BMF in this disease. We developed clinical trials to determine whether a sufficient number of CD34(+) stem cells could be collected for gene modification and to evaluate the safety and efficacy of HSC-corrective gene transfer in FA genotype A (FANCA) patients. Here, we report that FA patients have significant depletion of their BM CD34(+) cell compartment even before severe pancytopenia is present. However, oncoretroviral-mediated ex vivo gene transfer was efficient in clinical scale in FA-A cells, leading to reversal of the cellular phenotype in a significant percentage of CD34(+) cells. Re-infusion of gene-corrected products in two patients was safe and well tolerated and accompanied by transient improvements in hemoglobin and platelet counts. Gene correction was transient, likely owing to the low dose of gene-corrected cells infused. Our early experience shows that stem cell collection is well tolerated in FA patients and suggests that collection be considered as early as possible in patients who are potential candidates for future gene transfer trials.

Mesenchymal Stem Cell Benefits Observed in Bone Marrow Failure and Acquired Aplastic Anemia

Science.gov (United States)

Gonzaga, Vivian Fonseca; Lisboa, Gustavo Sabino; Frare, Eduardo Osório

2017-01-01

Acquired aplastic anemia (AA) is a type of bone marrow failure (BMF) syndrome characterized by partial or total bone marrow (BM) destruction resulting in peripheral blood (PB) pancytopenia, which is the reduction in the number of red blood cells (RBC) and white blood cells (WBC), as well as platelets (PLT). The first-line treatment option of AA is given by hematopoietic stem cell (HSCs) transplant and/or immunosuppressive (IS) drug administration. Some patients did not respond to the treatment and remain pancytopenic following IS drugs. The studies are in progress to test the efficacy of adoptive cellular therapies as mesenchymal stem cells (MSCs), which confer low immunogenicity and are reliable allogeneic transplants in refractory severe aplastic anemia (SAA) cases. Moreover, bone marrow stromal cells (BMSC) constitute an essential component of the hematopoietic niche, responsible for stimulating and enhancing the proliferation of HSCs by secreting regulatory molecules and cytokines, providing stimulus to natural BM microenvironment for hematopoiesis. This review summarizes scientific evidences of the hematopoiesis improvements after MSC transplant, observed in acquired AA/BMF animal models as well as in patients with acquired AA. Additionally, we discuss the direct and indirect contribution of MSCs to the pathogenesis of acquired AA. PMID:29333168

Clinical and genetic features of dyskeratosis congenita, cryptic dyskeratosis congenita, and Hoyeraal-Hreidarsson syndrome in Japan.

Science.gov (United States)

Yamaguchi, Hiroki; Sakaguchi, Hirotoshi; Yoshida, Kenichi; Yabe, Miharu; Yabe, Hiromasa; Okuno, Yusuke; Muramatsu, Hideki; Takahashi, Yoshiyuki; Yui, Shunsuke; Shiraishi, Yuichi; Chiba, Kenichi; Tanaka, Hiroko; Miyano, Satoru; Inokuchi, Koiti; Ito, Etsuro; Ogawa, Seishi; Kojima, Seiji

2015-11-01

Dyskeratosis congenita (DKC) is an inherited bone marrow failure (BMF) syndrome typified by reticulated skin pigmentation, nail dystrophy, and mucosal leukoplakia. Hoyeraal-Hreidarsson syndrome (HHS) is considered to be a severe form of DKC. Unconventional forms of DKC, which develop slowly in adulthood but without the physical anomalies characteristic of DKC (cryptic DKC), have been reported. Clinical and genetic features of DKC have been investigated in Caucasian, Black, and Hispanic populations, but not in Asian populations. The present study aimed to determine the clinical and genetic features of DKC, HHS, and cryptic DKC among Japanese patients. We analyzed 16 patients diagnosed with DKC, three patients with HHS, and 15 patients with cryptic DKC. We found that platelet count was significantly more depressed than neutrophil count or hemoglobin value in DKC patients, and identified DKC patients with large deletions in the telomerase reverse transcriptase and cryptic DKC patients with RTEL1 mutations on both alleles. This led to some patients previously considered to have unclassifiable BMF being diagnosed with cDKC through identification of new gene mutations. It thus seems important from a clinical viewpoint to re-examine the clinical characteristics, frequency of genetic mutations, and treatment efficacy in DKC, HHS, and cDKC.

Higher-order co-moments in asset pricing on the stock exchange in Brazil

Directory of Open Access Journals (Sweden)

Paulo Vitor Jordão da Gama Silva

2015-12-01

Full Text Available This study seeks to identify the behavior of systemic asymmetry (coskewness and systemic kurtosis (cokurtosis in asset pricing on the Brazilian stock exchange (in BM&F Bovespa. The methodology explored by Harvey and Siddique (2000 was used to estimate the degree of coskewness and cokurtosis for stocks in each month t, following the CAPM regression. The three-factor model was used according to Fama and French (1993, with modifications to the calculation of the factors following the methodology exploited by Neves (2003. The results show that for the Brazilian market, assets with negative coskewness and cokurtosis tend to yield more than assets with positive coskewness and cokurtosis. According to observations in the American and London markets, as investors expect higher returns for the high risk, a preference was found for negative coskewness and positive cokurtosis. In Brazil, it was found that in the case of coskewness, it repeats itself, but not for cokurtosis, where the reverse is true, which can lead to the conclusion of a typically risk-averse behavior.

Biomagnification of mercury and selenium in two lakes in southern Norway

Energy Technology Data Exchange (ETDEWEB)

Økelsrud, Asle, E-mail: asle.okelsrud@hit.no [Department of Environmental and Health Studies, University College of Southeast Norway, Hallvard Eikas Plass 1, 3800 Bø (Norway); Lydersen, Espen [Department of Environmental and Health Studies, University College of Southeast Norway, Hallvard Eikas Plass 1, 3800 Bø (Norway); Fjeld, Eirik [Norwegian Institute for Water Research, Gaustadalléen 21, 0349 Oslo (Norway)

2016-10-01

We have investigated bioaccumulation and trophic transfer of both mercury (Hg) and selenium (Se) in two lakes in southern Norway to reveal a suggested mitigating effect of Se on Hg biota accumulation. The study included analysis of total Se (Se), total Hg (Hg), and methyl-mercury (MeHg) in water, littoral and pelagic invertebrates and perch (Perca fluviatilis), together with stable isotope analysis (δ{sup 15}N and δ{sup 13}C) in biota. Mean dissolved Se ranged from 22 to 59 ng L{sup −1}, while Hg and MeHg in lake water ranged from 1 to 3 ng L{sup −1} and 0.01 to 0.06 ng L{sup −1}. Biota Se and Hg concentrations (dry weight) ranged from 0.41 mg Se kg{sup −1} and 0.06 mg Hg kg{sup −1} in primary littoral invertebrates and up to 2.9 mg Se kg{sup −1} and 3.6 mg Hg kg{sup −1} in perch. Both Hg and Se biomagnified in the food web, with a trophic magnification factor (TMF) of 4.64 for Hg and 1.29 for Se. The reported positive transfer of Se in the food web, despite the low measured dissolved Se, suggest that a major proportion of the Se in these lakes are both highly bioavailable and bioaccumulative. However, we did not find support for a Se-facilitated inhibition in the accumulation of Hg in perch, as Se and Hg concentrations in perch muscle correlated positively and Se did not explain any variations in Hg after we controlled for the effects of other important covariates. We postulate that this may be a result of insufficient concentrations of dissolved Se and subsequently in biota in our studied lakes for an efficient Hg sequestration up the food web. - Highlights: • Hg, Se and stable isotopes were investigated in biota in two Norwegian Boreal lakes • Both Hg and Se biomagnified in the food web, with a TMF of 4.64 and 1.29 respectively • Food carbon source, trophic level and age explained Se and Hg variations in perch • Perch muscle Se and Hg were positively correlated.

Biomagnification of mercury and selenium in two lakes in southern Norway

International Nuclear Information System (INIS)

Økelsrud, Asle; Lydersen, Espen; Fjeld, Eirik

2016-01-01

We have investigated bioaccumulation and trophic transfer of both mercury (Hg) and selenium (Se) in two lakes in southern Norway to reveal a suggested mitigating effect of Se on Hg biota accumulation. The study included analysis of total Se (Se), total Hg (Hg), and methyl-mercury (MeHg) in water, littoral and pelagic invertebrates and perch (Perca fluviatilis), together with stable isotope analysis (δ 15 N and δ 13 C) in biota. Mean dissolved Se ranged from 22 to 59 ng L −1 , while Hg and MeHg in lake water ranged from 1 to 3 ng L −1 and 0.01 to 0.06 ng L −1 . Biota Se and Hg concentrations (dry weight) ranged from 0.41 mg Se kg −1 and 0.06 mg Hg kg −1 in primary littoral invertebrates and up to 2.9 mg Se kg −1 and 3.6 mg Hg kg −1 in perch. Both Hg and Se biomagnified in the food web, with a trophic magnification factor (TMF) of 4.64 for Hg and 1.29 for Se. The reported positive transfer of Se in the food web, despite the low measured dissolved Se, suggest that a major proportion of the Se in these lakes are both highly bioavailable and bioaccumulative. However, we did not find support for a Se-facilitated inhibition in the accumulation of Hg in perch, as Se and Hg concentrations in perch muscle correlated positively and Se did not explain any variations in Hg after we controlled for the effects of other important covariates. We postulate that this may be a result of insufficient concentrations of dissolved Se and subsequently in biota in our studied lakes for an efficient Hg sequestration up the food web. - Highlights: • Hg, Se and stable isotopes were investigated in biota in two Norwegian Boreal lakes • Both Hg and Se biomagnified in the food web, with a TMF of 4.64 and 1.29 respectively • Food carbon source, trophic level and age explained Se and Hg variations in perch • Perch muscle Se and Hg were positively correlated

Current-use pesticides in seawater and their bioaccumulation in polar bear-ringed seal food chains of the Canadian Arctic.

Science.gov (United States)

Morris, Adam D; Muir, Derek C G; Solomon, Keith R; Letcher, Robert J; McKinney, Melissa A; Fisk, Aaron T; McMeans, Bailey C; Tomy, Gregg T; Teixeira, Camilla; Wang, Xiaowa; Duric, Mark

2016-07-01

The distribution of current-use pesticides (CUPs) in seawater and their trophodynamics were investigated in 3 Canadian Arctic marine food chains. The greatest ranges of dissolved-phase concentrations in seawater for each CUP were endosulfan sulfate (less than method detection limit (MDL) to 19 pg L(-1) ) > dacthal (0.76-15 pg L(-1) ) > chlorpyrifos (less than MDL to 8.1 pg L(-1) ) > pentachloronitrobenzene (less than MDL to 2.6 pg L(-1) ) > α-endosulfan (0.20-2.3 pg L(-1) ). Bioaccumulation factors (BAFs, water-respiring organisms) were greatest in plankton, including chlorothalonil (log BAF = 7.4 ± 7.1 L kg(-1) , mean ± standard error), chlorpyrifos (log BAF = 6.9 ± 6.7 L kg(-1) ), and α-endosulfan (log BAF = 6.5 ± 6.0 L kg(-1) ). The largest biomagnification factors (BMFs) were found for dacthal in the capelin:plankton trophic relationship (BMF = 13 ± 5.0) at Cumberland Sound (Nunvavut), and for β-endosulfan (BMF = 16 ± 4.9) and α-endosulfan (BMF = 9.3 ± 2.8) in the polar bear-ringed seal relationship at Barrow and Rae Strait (NU), respectively. Concentrations of endosulfan sulfate exhibited trophic magnification (increasing concentrations with increasing trophic level) in the poikilothermic portion of the food web (trophic magnification factor = 1.4), but all of the CUPs underwent trophic dilution in the marine mammal food web, despite some trophic level-specific biomagnification. Together, these observations are most likely indicative of metabolism of these CUPs in mammals. Environ Toxicol Chem 2016;35:1695-1707. © 2016 SETAC. © 2016 SETAC.

Precipitation and temperature drive seasonal variation in bioaccumulation of polycyclic aromatic hydrocarbons in the planktonic food webs of a subtropical shallow eutrophic lake in China.

Science.gov (United States)

Tao, Yuqiang; Yu, Jing; Xue, Bin; Yao, Shuchun; Wang, Sumin

2017-04-01

Hydrophobic organic contaminants (HOCs) are toxic and ubiquitous in aquatic environments and pose great risks to aquatic organisms. Bioaccumulation by plankton is the first step for HOCs to enter aquatic food webs. Trophic status is considered to dominate variations in bioaccumulation of HOCs in plankton in temperate and frigid deep oligotrophic waters. However, long-term driving factors for bioaccumulation of HOCs in planktonic food webs of subtropical shallow eutrophic waters have not been well investigated. China has the largest subtropical lake density in the Northern Hemisphere. Due to limited field data, long-term variations in the bioaccumulation of HOCs in these lakes are almost unknown. Here we take Lake Xuanwu as an example to investigate long-term variations in the bioaccumulation, and biomagnification of polycyclic aromatic hydrocarbon (PAHs) in planktonic food webs of subtropical shallow eutrophic lakes in China, and elucidate the driving factors. Our results indicate that temperature rather than nutrients dominates long-term dynamics of planktonic biomass in this lake. Precipitation significantly enhances the concentrations of the PAHs, and total suspended particles, and consequently affects the distribution of the PAHs in the water column. Biomass dilution induced by temperature dominates bioaccumulation of the PAHs by both phytoplankton and zooplankton (copepods and cladocerans). Biomagnification of the PAHs from phytoplankton to zooplankton is positively correlated with temperature. Our study suggests that temperature and precipitation drive long-term variations in the bioaccumulation of the PAHs in the planktonic food webs of this subtropical shallow eutrophic lake. Lake Xuanwu has a similar mean annual temperature, annual precipitation, sunshine duration, and nutrient levels as other subtropical shallow eutrophic lakes in China. This study may also help to understand the bioaccumulation of HOCs in planktonic food webs of other subtropical shallow

A review of wastewater handling in the Arctic with special reference to Pharmaceuticals and Personal Care Products (PPCPs) and microbial pollution

DEFF Research Database (Denmark)

Gunnarsdottir, Ragnhildur; Jenssen, Petter Deinboll; Jensen, Pernille Erland

2013-01-01

Treatment of wastewater is often inadequate or completely lacking in Arctic regions. Wastewater contains different kinds of substances that can be harmful for the environment and human health, including residues of pharmaceuticals and personal care products. Bioaccumulation and biomagnifications ...

Biomarkers of marine pollution and bioremediation

Digital Repository Service at National Institute of Oceanography (India)

Sarkar, A.

species of marine organisms and their bio-magnification across the food chain leading to serious threat to human health. In recent years, levels of contaminants in the marine environment have increased to a large extent as a consequence of vari- ous...

Bioconcentração e biomagnificação de metilmercúrio na baía de Guanabara, Rio de Janeiro

Directory of Open Access Journals (Sweden)

Helena A. Kehrig

2011-01-01

Full Text Available Methylmercury was determined in water and aquatic biota from Guanabara Bay. Trophic transfer of methylmercury was observed between trophic levels from prey (microplankton, mesoplankton and fish with different feeding habits to top predator (pelagic demersal fish. Top predator fish presented the highest methylmercury concentrations (320.3 ± 150.7 mg kg-1 dry wt., whereas microplankton presented the lowest (8.9 ± 3.3 mg kg-1 dry wt.. The successive amplification of methylmercury concentrations and its bioconcentration factor with increasing trophic levels from base to top indicate that biomagnification may be occurring along the food web. Results suggest the importance of feeding habits and trophic level in the bioaccumulation of methylmercury by aquatic biota.

Trophic relationships in an Arctic food web and implications for trace metal transfer

Energy Technology Data Exchange (ETDEWEB)

Dehn, Larissa-A. [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States)]. E-mail: ftld@uaf.edu; Follmann, Erich H. [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States); Thomas, Dana L. [Department of Mathematical Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-6660 (United States); Sheffield, Gay G. [Alaska Department of Fish and Game, Fairbanks, Division of Wildlife Conservation, Fairbanks, Alaska, 99701-1599 (United States); Rosa, Cheryl [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States); Duffy, Lawrence K. [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States); O' Hara, Todd M. [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States)

2006-06-01

Tissues of subsistence-harvested Arctic mammals were analyzed for silver (Ag), cadmium (Cd), and total mercury (THg). Muscle (or total body homogenates of potential fish and invertebrate prey) was analyzed for stable carbon ({delta} {sup 13}C) and nitrogen ({delta} {sup 15}N) isotopes to establish trophic interactions within the Arctic food chain. Food web magnification factors (FWMFs) and biomagnification factors for selected predator-prey scenarios (BMFs) were calculated to describe pathways of heavy metals in the Alaskan Arctic. FWMFs in this study indicate that magnification of selected heavy metals in the Arctic food web is not significant. Biomagnification of Cd occurs mainly in kidneys; calculated BMFs are higher for hepatic THg than renal THg for all predator-prey scenarios with the exception of polar bears (Ursus maritimus). In bears, the accumulation of renal THg is approximately 6 times higher than in liver. Magnification of hepatic Ag is minimal for all selected predator-prey scenarios. Though polar bears occupy a higher trophic level than belugas (Delphinapterus leucas), based on {delta} {sup 15}N, the metal concentrations are either not statistically different between the two species or lower for bears. Similarly, concentrations of renal and hepatic Cd are significantly lower or not statistically different in polar bears compared to ringed (Phoca hispida) and bearded seals (Erignathus barbatus), their primary prey. THg, on the other hand, increased significantly from seal to polar bear tissues. Mean {delta} {sup 15}N was lowest in muscle of Arctic fox (Alopex lagopus) and foxes also show the lowest levels of Hg, Cd and Ag in liver and kidney compared to the other species analyzed. These values are in good agreement with a diet dominated by terrestrial prey. Metal deposition in animal tissues is strongly dependent on biological factors such as diet, age, sex, body condition and health, and caution should be taken when interpreting magnification of

Trophic relationships in an Arctic food web and implications for trace metal transfer

International Nuclear Information System (INIS)

Dehn, Larissa-A.; Follmann, Erich H.; Thomas, Dana L.; Sheffield, Gay G.; Rosa, Cheryl; Duffy, Lawrence K.; O'Hara, Todd M.

2006-01-01

Tissues of subsistence-harvested Arctic mammals were analyzed for silver (Ag), cadmium (Cd), and total mercury (THg). Muscle (or total body homogenates of potential fish and invertebrate prey) was analyzed for stable carbon (δ 13 C) and nitrogen (δ 15 N) isotopes to establish trophic interactions within the Arctic food chain. Food web magnification factors (FWMFs) and biomagnification factors for selected predator-prey scenarios (BMFs) were calculated to describe pathways of heavy metals in the Alaskan Arctic. FWMFs in this study indicate that magnification of selected heavy metals in the Arctic food web is not significant. Biomagnification of Cd occurs mainly in kidneys; calculated BMFs are higher for hepatic THg than renal THg for all predator-prey scenarios with the exception of polar bears (Ursus maritimus). In bears, the accumulation of renal THg is approximately 6 times higher than in liver. Magnification of hepatic Ag is minimal for all selected predator-prey scenarios. Though polar bears occupy a higher trophic level than belugas (Delphinapterus leucas), based on δ 15 N, the metal concentrations are either not statistically different between the two species or lower for bears. Similarly, concentrations of renal and hepatic Cd are significantly lower or not statistically different in polar bears compared to ringed (Phoca hispida) and bearded seals (Erignathus barbatus), their primary prey. THg, on the other hand, increased significantly from seal to polar bear tissues. Mean δ 15 N was lowest in muscle of Arctic fox (Alopex lagopus) and foxes also show the lowest levels of Hg, Cd and Ag in liver and kidney compared to the other species analyzed. These values are in good agreement with a diet dominated by terrestrial prey. Metal deposition in animal tissues is strongly dependent on biological factors such as diet, age, sex, body condition and health, and caution should be taken when interpreting magnification of dynamic and actively regulated trace metals

Clinical and Molecular Heterogeneity of RTEL1 Deficiency

Directory of Open Access Journals (Sweden)

Marcin W. Wlodarski

2017-05-01

Full Text Available Typical features of dyskeratosis congenita (DC resulting from excessive telomere shortening include bone marrow failure (BMF, mucosal fragility, and pulmonary or liver fibrosis. In more severe cases, immune deficiency and recurring infections can add to disease severity. RTEL1 deficiency has recently been described as a major genetic etiology, but the molecular basis and clinical consequences of RTEL1-associated DC are incompletely characterized. We report our observations in a cohort of six patients: five with novel biallelic RTEL1 mutations p.Trp456Cys, p.Ile425Thr, p.Cys1244ProfsX17, p.Pro884_Gln885ins53X13, and one with novel heterozygous mutation p.Val796AlafsX4. The most unifying features were hypocellular BMF in 6/6 and B-/NK-cell lymphopenia in 5/6 patients. In addition, three patients with homozygous mutations p.Trp456Cys or p.Ile425Thr also suffered from immunodeficiency, cerebellar hypoplasia, and enteropathy, consistent with Hoyeraal-Hreidarsson syndrome. Chromosomal breakage resembling a homologous recombination defect was detected in patient-derived fibroblasts but not in hematopoietic compartment. Notably, in both cellular compartments, differential expression of 1243aa and 1219/1300aa RTEL1 isoforms was observed. In fibroblasts, response to ionizing irradiation and non-homologous end joining were not impaired. Telomeric circles did not accumulate in patient-derived primary cells and lymphoblastoid cell lines, implying alternative pathomechanisms for telomeric loss. Overall, RTEL1-deficient cells exhibited a phenotype of replicative exhaustion, spontaneous apoptosis and senescence. Specifically, CD34+ cells failed to expand in vitro, B-cell development was compromised, and T-cells did not proliferate in long-term culture. Finally, we report on the natural history and outcome of our patients. While two patients died from infections, hematopoietic stem cell transplantation (HSCT resulted in sustained engraftment in two patients

Clinical and Molecular Heterogeneity of RTEL1 Deficiency.

Science.gov (United States)

Speckmann, Carsten; Sahoo, Sushree Sangita; Rizzi, Marta; Hirabayashi, Shinsuke; Karow, Axel; Serwas, Nina Kathrin; Hoemberg, Marc; Damatova, Natalja; Schindler, Detlev; Vannier, Jean-Baptiste; Boulton, Simon J; Pannicke, Ulrich; Göhring, Gudrun; Thomay, Kathrin; Verdu-Amoros, J J; Hauch, Holger; Woessmann, Wilhelm; Escherich, Gabriele; Laack, Eckart; Rindle, Liliana; Seidl, Maximilian; Rensing-Ehl, Anne; Lausch, Ekkehart; Jandrasits, Christine; Strahm, Brigitte; Schwarz, Klaus; Ehl, Stephan R; Niemeyer, Charlotte; Boztug, Kaan; Wlodarski, Marcin W

2017-01-01

Typical features of dyskeratosis congenita (DC) resulting from excessive telomere shortening include bone marrow failure (BMF), mucosal fragility, and pulmonary or liver fibrosis. In more severe cases, immune deficiency and recurring infections can add to disease severity. RTEL1 deficiency has recently been described as a major genetic etiology, but the molecular basis and clinical consequences of RTEL1-associated DC are incompletely characterized. We report our observations in a cohort of six patients: five with novel biallelic RTEL1 mutations p.Trp456Cys, p.Ile425Thr, p.Cys1244ProfsX17, p.Pro884_Gln885ins53X13, and one with novel heterozygous mutation p.Val796AlafsX4. The most unifying features were hypocellular BMF in 6/6 and B-/NK-cell lymphopenia in 5/6 patients. In addition, three patients with homozygous mutations p.Trp456Cys or p.Ile425Thr also suffered from immunodeficiency, cerebellar hypoplasia, and enteropathy, consistent with Hoyeraal-Hreidarsson syndrome. Chromosomal breakage resembling a homologous recombination defect was detected in patient-derived fibroblasts but not in hematopoietic compartment. Notably, in both cellular compartments, differential expression of 1243aa and 1219/1300aa RTEL1 isoforms was observed. In fibroblasts, response to ionizing irradiation and non-homologous end joining were not impaired. Telomeric circles did not accumulate in patient-derived primary cells and lymphoblastoid cell lines, implying alternative pathomechanisms for telomeric loss. Overall, RTEL1-deficient cells exhibited a phenotype of replicative exhaustion, spontaneous apoptosis and senescence. Specifically, CD34 + cells failed to expand in vitro , B-cell development was compromised, and T-cells did not proliferate in long-term culture. Finally, we report on the natural history and outcome of our patients. While two patients died from infections, hematopoietic stem cell transplantation (HSCT) resulted in sustained engraftment in two patients. Whether

Financing Decisions of Companies Listed in the Different Segments of Corporate Governance of BM&FBovespa According to Pecking Order Theory

OpenAIRE

Tani, Bruna Bagalhi; Albanez, Tatiana

2016-01-01

Among the various theories about capital structure is Pecking Order theory, which establishes a hierarchy of preferences for sources of funding due to the existence of information asymmetry. In this paper, we seek to verify if this theory applies to the financing decisions of Brazilian companies that are listed in the different segments of corporate governance of BMF&Bovespa, analyzing whether, in the 2010-2014 period, a higher level of corporate governance implies lower adherence to this...

Financing Decisions of Companies Listed in the Different Segments of Corporate Governance of BM&FBovespa According to Pecking Order Theory

OpenAIRE

Tani, Bruna Bagalhi; Albanez, Tatiana

2016-01-01

Among the various theories about capital structure is Pecking Order theory, which establishes a hierarchy of preferences for sources of funding due to the existence of information asymmetry. In this paper, we seek to verify if this theory applies to the financing decisions of Brazilian companies that are listed in the different segments of corporate governance of BMF&Bovespa, analyzing whether, in the 2010-2014 period, a higher level of corporate governance implies lower adherence to this the...

The Role of Histone Demethylase Jmjd3 in Immune-Mediated Aplastic Anemia

Science.gov (United States)

2017-03-01

AWARD NUMBER: W81XWH-16-1-0055 TITLE: The Role of Histone Demethylase Jmjd3 in Immune-Mediated Aplastic Anemia PRINCIPAL INVESTIGATOR: Yi...Immune-Mediated Aplastic Anemia 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-16-1-0055 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Yi Zhang 5d... anemia (AA) is a condition of bone marrow failure (BMF) characterized by blood pancytopenia and BM hypoplasia. In most cases, AA is an immune-mediated

Automated Analysis of Vital Signs to Identify Patients with Substantial Bleeding before Hospital Arrival: A Feasibility Study

Science.gov (United States)

2015-05-01

alarms at the expense of some alarm latency. Clinical outcomes For the BMF data set, a research nurse collected patient attributes and outcome data via...during the initial 24 h in the hospital (B24-h PRBC volume[). For comparison, we also computed the proportion of patients with other hemodynamic ...challenges. JAMA 289(8):1027Y1030, 2003. 17. Lovett PB, Buchwald JM, Stürmann K, Bijur P: The vexatious vital: neither clinical measurements by nurses

210Po and 210Pb trophic transfer within the phytoplankton–zooplankton–anchovy/sardine food web: a case study from the Gulf of Lion (NW Mediterranean Sea)

International Nuclear Information System (INIS)

Strady, Emilie; Harmelin-Vivien, Mireille; Chiffoleau, Jean François; Veron, Alain; Tronczynski, Jacek; Radakovitch, Olivier

2015-01-01

The transfer of 210 Po and 210 Pb in the food web of small pelagic fishes (from phytoplankton and zooplankton to anchovy Engraulis encrasicolus and sardine Sardina pilchardus) is investigated in the Gulf of Lion (GoL). We present original data of 210 Po and 210 Pb activity concentrations, C and N stable isotope ratios, measured (i) from different size classes of phytoplankton and zooplankton during spring and winter in different environments of the GoL, and (ii) in two fish species. Significant spatial patterns based on 210 Po, 210 Pb activity concentrations and 210 Po/ 210 Pb ratios in the different plankton size classes are evidenced by hierarchical clustering, both in spring and winter. This variability, also observed for C and N stable isotopes ratios, is connected to local specific pelagic habitats and hydrodynamics. The sampling strategy suggests that 210 Po bioaccumulation in the GoL remains at a constant level from the first (dominated by phytoplankton) to the second trophic level (zooplankton), while 210 Pb bioaccumulation shows an increase in winter. Based on stable N isotope ratios and 210 Po activity concentrations measured in anchovies and sardines, we evidence 210 Po bio-magnification along the trophic food web of these two planktivorous pelagic fishes. - Highlights: • 210 Po and 210 Pb activity concentrations in plankton vary up to a factor of two in the Gulf of Lion (East vs West). • 210 Po and 210 Pb variability is connected to local specific pelagic habitats. • Bio-magnification of 210 Po is evidenced in anchovy/sardine foodwebs

Apreçamento de opções de IDI usando o modelo CIR

Directory of Open Access Journals (Sweden)

José Santiago Fajardo Barbachan

2003-06-01

Full Text Available A opção de IDI da BM&F possui características peculiares que torna o seu apreçamento diferente das opções de taxa de juros mais comuns, como as de títulos de renda fixa. Este artigo desenvolve uma fórmula para apreçamento dessas opções de IDI, utilizando a precificação livre de arbitragem. O modelo utilizado considera apenas um fator estocástico: a taxa de juros livre de risco de curto prazo. A equação diferencial usada para modelar o comportamento da taxa de juros é a do modelo CIR (COX INGERSOLL & ROSS, 1985, que possui reversão à média e não permite a existência de taxas de juros nominais negativas. Também é feita uma estimação dos parâmetros do modelo proposto baseando-se em dados históricos, para então comparar o preço teórico da opção baseado nestes parâmetros com os preços de mercado e com o preço teórico considerando a modelagem de Vasicek (1977.The IDI option from the BM&F (Commodities and Futures Exchange has unusual characteristics, that make its pricing different from common interest rate options. This paper develops a closed form formula for the pricing of these IDI options, using an arbitrage-free pricing approach. The model used considers only one stochastic factor: the short-term risk-free interest rate. The differential equation used to model the behavior of the interest rate comes from the CIR (COX INGERSOLL & ROSS, 1985 model, which has mean reversion property and does not allow negative nominal interest rates. It is also done a parameter estimation of the proposed model based on historic data, and then compares the theoretical price of the option based on these parameters with the market price and with the theoretical price considering the Vasicek (1977 model.

Department of Physical Sciences

African Journals Online (AJOL)

USER

2017-05-05

May 5, 2017 ... ... of Physical Sciences, The Open University of Tanzania, P. O. Box ... bioaccumulation and biomagnification in the food chain. This research deals with human health risk assessment of metal contamination through the .... poisoning is untreatable (Faller, 2009). ... probability of adverse health effects in.

FANCA and FANCG are the major Fanconi anemia genes in the Korean population.

Science.gov (United States)

Park, J; Chung, N-G; Chae, H; Kim, M; Lee, S; Kim, Y; Lee, J-W; Cho, B; Jeong, D C; Park, I Y

2013-09-01

Fanconi anemia (FA) is a rare disorder characterized by physical abnormalities, bone marrow failure (BMF), increased risk of malignancies, and cellular hypersensitivity to DNA cross-linking agents. This study evaluated the genetic alterations in three major Fanconi genes (FANCA, FANCC, and FANCG) in 30 FA patients using multiplex ligation-dependent probe amplification and direct sequencing. Thirteen BMF patients were genetically classified as FA-A (n = 6, 46%) and FA-G (n = 7, 54%). Four common founder mutations were identified and included two FANCA mutations (c.2546delC and c.3720_3724delAAACA) and two FANCG mutations (c.307+1G>C and c.1066C>T), which had previously been commonly observed in a Japanese FA population. We also detected four novel deleterious mutations: c.2778+1G>C and c.3627-1G>A of FANCA, and c.1589_1591delATA and c.1761-1G>A of FANCG. This study shows that mutations in FANCA and FANCG are common in Korean FA patients and the existence of four common founder mutations in an East Asian FA population. Mutation screening workflow that includes these common mutations may be useful in the creation of an international database, and to better understand the ethnic characteristics of FA. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

MODEL 9977 B(M)F-96 SAFETY ANALYSIS REPORT FOR PACKAGING

Energy Technology Data Exchange (ETDEWEB)

Abramczyk, G; Paul Blanton, P; Kurt Eberl, K

2006-05-18

This Safety Analysis Report for Packaging (SARP) documents the analysis and testing performed on and for the 9977 Shipping Package, referred to as the General Purpose Fissile Package (GPFP). The performance evaluation presented in this SARP documents the compliance of the 9977 package with the regulatory safety requirements for Type B packages. Per 10 CFR 71.59, for the 9977 packages evaluated in this SARP, the value of ''N'' is 50, and the Transport Index based on nuclear criticality control is 1.0. The 9977 package is designed with a high degree of single containment. The 9977 complies with 10 CFR 71 (2002), Department of Energy (DOE) Order 460.1B, DOE Order 460.2, and 10 CFR 20 (2003) for As Low As Reasonably Achievable (ALARA) principles. The 9977 also satisfies the requirements of the Regulations for the Safe Transport of Radioactive Material--1996 Edition (Revised)--Requirements. IAEA Safety Standards, Safety Series No. TS-R-1 (ST-1, Rev.), International Atomic Energy Agency, Vienna, Austria (2000). The 9977 package is designed, analyzed and fabricated in accordance with Section III of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code, 1992 edition.

Selection of superior salt/boron tolerant Stanleya pinnata genotypes and quantification of their selenium phytoremediation abilities in drainage sediment.

Science.gov (United States)

The semi-metallic mineral Se, a naturally-occurring trace element, is primarily found as selenate originating from sedimentary and shale rock formations, e.g., in the western side of the San Joaquin Valley of central California (WSJV). Because selenate-Se is water soluble, bioavailable and biomagnif...

The major and trace element chemistry of fish and lake water within ...

African Journals Online (AJOL)

Chemical elements in lake water are incorporated into fish tissues through bioconcentration and biomagnification. Lake water and fish tissue samples from 23 lakes, located within 4 major South African catchments, were analysed to investigate the link between element concentrations in lake water and otolith, fin spine, ...

Bioaccumulation and biotransformation of brominated and chlorinated contaminants and their metabolites in ringed seals (Pusa hispida) and polar bears (Ursus maritimus) from East Greenland.

Science.gov (United States)

Letcher, Robert J; Gebbink, Wouter A; Sonne, Christian; Born, Erik W; McKinney, Melissa A; Dietz, Rune

2009-11-01

from seals is the main source of OH-PBDEs in the bear tissues. Our findings demonstrated from ringed seal to polar bears that organohalogen biotransformation, bioaccumulation and/or biomagnification varied widely and depended on the contaminant in question. Our results show the increasing complexity of bioaccumulated and in some cases biomagnified, chlorinated and brominated contaminants and/or metabolites from the diet may be a contributing stress factor in the health of East Greenland polar bears.

Application of Trophic Magnification Factors (TMFs) Under the ...

Science.gov (United States)

Directive 2013/39/EU amending and updating the Water Framework Directive (2000/60/EC) and its Daughter Directive (the so-called EQS Directive: 2008/105/EC) sets Environmental Quality Standards for biota (EQSbiota) for a number of bioaccumulative chemicals which can pose a threat to both aquatic wildlife (piscivorous birds and mammals) and human health via the consumption of contaminated prey or the intake of contaminated food originating from the aquatic environment. Member States (MS) of the European Union will need to establish programs to monitor the concentration of 11 priority substances in biota and assess compliance against these new standards for surface water classification. The biota standards essentially refer to fish and should be applied to the trophic level (TL) at which contaminant concentrations peak, so that the predator of the species at that TL is exposed to the highest contaminant levels in its food. For chemicals that are subject to biomagnification, the peak concentrations are theoretically attained at TL 3 to 4 in freshwater food webs and TL 5 in marine food webs, where the risk of secondary poisoning of top predators should also be considered. An EU-wide guidance effectively addresses the implementation of EQSbiota (EC 2014). Flexibility is allowed in the choice of target species used for monitoring because of the diversity of both habitats and aquatic community composition across Europe. According to that guidance, the consistency and co

Bioaccumulation of heavy metals by Dyera costulata cultivated in ...

African Journals Online (AJOL)

High concentrations of heavy metals are harmful to plants, animals and humans and their potential accumulation in human tissues and bio-magnification through the food chain cause serious health hazards. An experiment was conducted in the glasshouse to evaluate the potential of Dyera costulata as a bioaccumulator to ...

Mercury and lead concentrations in six cartilaginous fish species ...

African Journals Online (AJOL)

Mercury and lead concentrations in cartilaginous fishes from Lagos Lagoon and coastal waters of South-West Nigeria were investigated between May and August 2013. There are obvious discharges of toxic heavy metal substances into these waters and which can get to man by bioaccumulation and biomagnifications in ...

Foreign portfolio capital flows and stock returns: a study of Brazilian listed firms

Directory of Open Access Journals (Sweden)

Tiago Rodrigues Loncan

2015-12-01

Full Text Available Abstract This study analyzed the effect of foreign portfolio capital flows on stock returns of Brazilian listed firms through a 6-factors APT model, in which an additional risk factor for foreign portfolio capital flows was included. First, an aggregate analysis was conducted. The partial effect of foreign portfolio capital flows on the IBOVESPA index’s returns was statistically significant and positive. Next, a disaggregate analysis was also implemented, in which portfolios of stocks were sorted by sector of economic activity, level of risk and level of corporate governance. Foreign portfolio capitals caused increases in returns especially for sectors related to commodities, industry and cyclical consumption. For the portfolios sorted by risk (in which the stocks’ betas were used as a risk parameter for sorting, foreign capitals increased the returns of mid-high and high beta portfolios, but decreased the returns of low and low-mid beta portfolios. For corporate governance portfolios, the firms listed on the Novo Mercado segment (according to BMF&Bovespa criteria experienced a statistically significant revaluation effect. Overall, the results of the study provide support to the revaluation effect hypothesis.

Evaluation of the factors involved in bioaccumulation of gamma-emmitting radionuclides in white-tailed deer (Odocoileus virginanus). Final report

International Nuclear Information System (INIS)

Jenkins, J.H.

1977-01-01

The objectives of the work were to: determine the amounts and kinds of fallout gamma emitting radionuclides in an important food and sport animal, the white-tailed deer (Odocoileus virginianus) in the southeastern U.S.A.; elucidate some of the food chain interrelationships around the year; and see if a relationship exists between bioaccumulation in deer, the soils, the deer foods available, the rumen contents, and uptake in man. Whole body counters were constructed to measure the gamma rays emitted by animals varying in size from warblers (10 grams) and cotton rats (100 grams) up through live deer and people. Over 1800 deer from throughout the Southeast were analyzed. Deer from the Flatwoods sub-type of the Lower Coastal Plain region often have 137 Cs levels exceeding those reported for Alaskan Caribou at their peak and 90 Sr is as effectively transported through the Lower Coastal Plains environment as 137 Cs. Detailed studies have been conducted on two sites (Piedmont and Lower Coastal Plain) to determine the characteristics of soil and vegetation contributing to biomagnification

Contrasting PCB bioaccumulation patterns among Lake Huron lake trout reflect basin-specific ecology.

Science.gov (United States)

Paterson, Gordon; Ryder, Mark; Drouillard, Ken G; Haffner, G Douglas

2016-01-01

This study collected multiple age classes of lake trout from Lake Huron's Main Basin, Georgian Bay, and North Channel regions to compare and contrast top predator polychlorinated biphenyl (PCB) bioaccumulation patterns in separate compartments of the same ecosystem. Sum PCB concentrations were highest for Main Basin (260 ± 24.9 ng g(-1) wet wt) fish, followed by Georgian Bay (74.6 ± 16.2 ng g(-1) ) and North Channel (42.0 ± 3.3 ng g(-1)) fish. Discriminant functions analysis of lake trout PCB profiles and stable carbon (δ(13)C) and nitrogen (δ(15)N) isotope values clearly distinguished fish by location, indicating high degrees of basin fidelity throughout their lifetimes in addition to highly contrasting PCB bioaccumulation profiles. These unique profiles were not attributable to significant differences in lake trout lipid contents (p = 0.856) or trophic position (δ(15)N; p = 0.334), with rainbow smelt representing the primary prey across the basins. Furthermore, significant differences were observed among the basins for the relationships between PCB biomagnification factors and hydrophobicity. An empirical model for predicting PCB biomagnification in Lake Huron lake trout indicated that basin-specific population growth rates and prey abundances were significant for explaining these contrasting patterns of PCB bioaccumulation. The results of the present study are fundamental for understanding the role of ecology in legacy persistent organic pollutant (POP) bioaccumulation. Specifically, ecosystem characteristics such as prey abundances, foraging ecology, and ultimately consumer growth can regulate the variability of legacy POP bioaccumulation as observed within and among a wide range of freshwater ecosystems. © 2015 SETAC.

Performance and risk assessment of Bambara beans grown on ...

African Journals Online (AJOL)

Safe levels of exposure to contaminants were further investigated using albino Wistar rats for 28 feeding trial days to trace inherent biomagnifications. Bambara beans extracted up to 88.88 and 43.38 mg/kg into its shoot and root respectively at 10% contaminant dose while achieving 63.17% Cu removal unamended. Poultry

A hípotese das expectativas na estrutura a termo de juros no Brasil: uma aplicação de modelos de valor presente

OpenAIRE

Lima, Alexandre Maia Correia

2002-01-01

Utilizando dados financeiros brasileiros da BM&F, testa-se a validade do modelo de valor pre- sente (MVP) na estrutura a termo de juros, também conhecido na literatura como Hipótese das Expectativas. Estes modelos relacionam a taxa de juros de longo prazo à uma média das taxas de juros de curto-prazo mais um prêmio de risco, invariante no tempo. Associada a estes modelos está a questão da previsibilidade dos retornos de ativos financeiros ou, mais especificamente, a previsibilidade n...

Cell survival, cell death and cell cycle pathways are interconnected: Implications for cancer therapy

DEFF Research Database (Denmark)

Maddika, S; Ande, SR; Panigrahi, S

2007-01-01

)), and the Cip1/Waf1/Kip1-2-family (p21(Cip1/Waf1), p27(Kip1), p57(Kip2)) are shown both in the context of proliferation regulators and as contributors to the apoptotic machinery. Bcl2-family members (i.e. Bcl2, Bcl-X(L) Mcl-1(L); Bax, Bok/Mtd, Bak, and Bcl-X(S); Bad, Bid, Bim(EL), Bmf, Mcl-1(S)) are highlighted...... approaches that would involve redirecting over-active survival and proliferation pathways towards induction of apoptosis in cancer cells....

Large scale surveys suggest limited mercury availability in tropical north Queensland (Australia)

International Nuclear Information System (INIS)

Jardine, Timothy D.; Halliday, Ian A.; Howley, Christina; Sinnamon, Vivian; Bunn, Stuart E.

2012-01-01

Little is known about the threat of mercury (Hg) to consumers in food webs of Australia's wet–dry tropics. This is despite high concentrations in similar biomes elsewhere and a recent history of gold mining that could lead to a high degree of exposure for biota. We analysed Hg in water, sediments, invertebrates and fishes in rivers and estuaries of north Queensland, Australia to determine its availability and biomagnification in food webs. Concentrations in water and sediments were low relative to other regions of Hg concern, with only four of 138 water samples and five of 60 sediment samples above detection limits of 0.1 μg L −1 and 0.1 μg g −1 , respectively. Concentrations of Hg in fishes and invertebrates from riverine and wetland food webs were well below international consumption guidelines, including those in piscivorous fishes, likely due to low baseline concentrations and limited rates of biomagnification (average slope of log Hg vs. δ 15 N = 0.08). A large fish species of recreational, commercial, and cultural importance (the barramundi, Lates calcarifer), had low concentrations that were below consumption guidelines. Observed variation in Hg concentrations in this species was primarily explained by age and foraging location (floodplain vs. coastal), with floodplain feeders having higher Hg concentrations than those foraging at sea. These analyses suggest that there is a limited threat of Hg exposure for fish-eating consumers in this region. - Highlights: ► Hg concentrations in freshwaters and sediments of north Queensland were low. ► Biomagnification of Hg through riverine food webs was limited. ► Barramundi, a predatory fish, had low concentrations meaning low risk for consumers. ► Floodplain-feeding barramundi had higher Hg concentrations than coastal feeders.

Accumulation of selenium in aquatic systems downstream of a uranium mining operation in northern Saskatchewan, Canada

International Nuclear Information System (INIS)

Muscatello, J.R.; Belknap, A.M.; Janz, D.M.

2008-01-01

The objective of this study was to investigate the accumulation of selenium in lakes downstream of a uranium mine operation in northern Saskatchewan, Canada. Selenium concentrations in sediment and biota were elevated in exposure areas even though water concentrations were low (<5 μg/L). The pattern (from smallest to largest) of selenium accumulation was: periphyton < plankton and filterer invertebrates < detritivore and predator invertebrates < small bodied (forage) fish and predatory fish. Biomagnification of selenium resulted in an approximately 1.5-6 fold increase in the selenium content between plankton, invertebrates and forage fish. However, no biomagnification was observed between forage fish and predatory fish. Selenium content in organisms from exposure areas exceeded the proposed 3-11 μg/g (dry weight) dietary toxicity threshold for fish, suggesting that the selenium released into these aquatic systems has the potential to bioaccumulate and reach levels that could impair fish reproduction. - Selenium bioaccumulation patterns in a north temperate, cold water aquatic ecosystem were similar to those reported from warm water systems

Tracking Dietary Sources of Short- and Medium-Chain Chlorinated Paraffins in Marine Mammals through a Subtropical Marine Food Web.

Science.gov (United States)

Zeng, Lixi; Lam, James C W; Chen, Hui; Du, Bibai; Leung, Kenneth M Y; Lam, Paul K S

2017-09-05

Our previous study revealed an elevated accumulation of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in marine mammals from Hong Kong waters in the South China Sea. To examine the bioaccumulation potential and biomagnification in these apex predators, we sampled the dietary items of marine mammals and tracked the sources of SCCPs and MCCPs through a marine food web in this region. Sixteen fish species, seven crustacean species, and four mollusk species were collected, and the main prey species were identified for two species of marine mammals. Concentrations of ∑SCCPs and ∑MCCPs in these collected species suggested a moderate pollution level in Hong Kong waters compared to the global range. Lipid content was found to mediate congener-specific bioaccumulation in these marine species. Significantly positive correlations were observed between trophic levels and concentrations of ∑SCCPs or ∑MCCPs (p mammals was observed. This is the first report of dietary source tracking of SCCPs and MCCPs in marine mammals. The elevated biomagnification between prey and marine mammals raises environmental concerns about these contaminants.

BFM. Maja lava taga = BMF. The building behind the scenes / Triin Ojari

Index Scriptorium Estoniae

Ojari, Triin, 1974-

2012-01-01

Balti Filmi- ja Meediakooli uuest hoonest. Projekteerija: Salto Arhitektid. Autorid: Maarja Kask, Karli Luik, Ralf Lõoke, Pelle-Sten Viiburg. Sisekujundus: Ville Lausmäe. Projekt: 2009-2011, valmis: 2012

Fanconi Anemia: A DNA repair disorder characterized by accelerated decline of the hematopoietic stem cell compartment and other features of aging.

Science.gov (United States)

Brosh, Robert M; Bellani, Marina; Liu, Yie; Seidman, Michael M

2017-01-01

Fanconi Anemia (FA) is a rare autosomal genetic disorder characterized by progressive bone marrow failure (BMF), endocrine dysfunction, cancer, and other clinical features commonly associated with normal aging. The anemia stems directly from an accelerated decline of the hematopoietic stem cell compartment. Although FA is a complex heterogeneous disease linked to mutations in 19 currently identified genes, there has been much progress in understanding the molecular pathology involved. FA is broadly considered a DNA repair disorder and the FA gene products, together with other DNA repair factors, have been implicated in interstrand cross-link (ICL) repair. However, in addition to the defective DNA damage response, altered epigenetic regulation, and telomere defects, FA is also marked by elevated levels of inflammatory mediators in circulation, a hallmark of faster decline in not only other hereditary aging disorders but also normal aging. In this review, we offer a perspective of FA as a monogenic accelerated aging disorder, citing the latest evidence for its multi-factorial deficiencies underlying its unique clinical and cellular features. Published by Elsevier B.V.

Trophic transfer potential of aluminium oxide nanoparticles using representative primary producer (Chlorella ellipsoides) and a primary consumer (Ceriodaphnia dubia)

International Nuclear Information System (INIS)

Pakrashi, Sunandan; Dalai, Swayamprava; Chandrasekaran, Natarajan; Mukherjee, Amitava

2014-01-01

Highlights: • Trophic transfer of alumina nanoparticles using Chlorella ellipsoides and Ceriodaphnia dubia. • Subtle alterations in the feeding behaviour of the daphnids. • Disruption the energy flow through the food chain. • Transmission electron microscopy validated the disrupted feeding behaviour. - Abstract: The transfer of nanoparticles through the food chain can lead to bioaccumulation and biomagnification resulting in a long term negative impact on the ecosystem functions. The primary objective of this study was evaluation of aluminium oxide nanoparticles transfer from primary producers to primary consumers. A simple set up consisting of a primary producer (Chlorella ellipsoides) and a primary consumer (Ceriodaphnia dubia) was used. Here, C. ellipsoides were exposed to the varying concentrations of the nanoparticles ranging from 20 to 120 μg/mL (196 to 1176 μM) for 48 h and the infested algal cells were used as the feed to C. dubia. The bioaccumulation of the nanoparticles into the daphnids was noted and the biomagnification factors were computed. The exposure was noted to cause subtle alterations in the feeding behaviour of the daphnids. This might have long term consequences in the energy flow through the food chain. The reproductive behaviour of the daphnids remained unaffected upon exposure to nanoparticle infested algal feed. Distinct observations at ultra-structural scale using transmission electron microscopy provided visual evidences for the disrupted feeding behaviour upon exposure to nanoparticle treated algae. Internalization of nanoparticle like inclusion bodies in the intracellular space of algae was also detected. The findings were further substantiated by a detailed analysis of hydrodynamic stability, bioavailability and dissolution of ions from the nanoparticles over the exposure period. Altogether, the study brings out the first of its kind of observation of trophic transfer potential/behaviour of aluminium oxide nanoparticles and

Trophic transfer potential of aluminium oxide nanoparticles using representative primary producer (Chlorella ellipsoides) and a primary consumer (Ceriodaphnia dubia)

Energy Technology Data Exchange (ETDEWEB)

Pakrashi, Sunandan; Dalai, Swayamprava; Chandrasekaran, Natarajan; Mukherjee, Amitava, E-mail: amit.mookerjea@gmail.com

2014-07-01

Highlights: • Trophic transfer of alumina nanoparticles using Chlorella ellipsoides and Ceriodaphnia dubia. • Subtle alterations in the feeding behaviour of the daphnids. • Disruption the energy flow through the food chain. • Transmission electron microscopy validated the disrupted feeding behaviour. - Abstract: The transfer of nanoparticles through the food chain can lead to bioaccumulation and biomagnification resulting in a long term negative impact on the ecosystem functions. The primary objective of this study was evaluation of aluminium oxide nanoparticles transfer from primary producers to primary consumers. A simple set up consisting of a primary producer (Chlorella ellipsoides) and a primary consumer (Ceriodaphnia dubia) was used. Here, C. ellipsoides were exposed to the varying concentrations of the nanoparticles ranging from 20 to 120 μg/mL (196 to 1176 μM) for 48 h and the infested algal cells were used as the feed to C. dubia. The bioaccumulation of the nanoparticles into the daphnids was noted and the biomagnification factors were computed. The exposure was noted to cause subtle alterations in the feeding behaviour of the daphnids. This might have long term consequences in the energy flow through the food chain. The reproductive behaviour of the daphnids remained unaffected upon exposure to nanoparticle infested algal feed. Distinct observations at ultra-structural scale using transmission electron microscopy provided visual evidences for the disrupted feeding behaviour upon exposure to nanoparticle treated algae. Internalization of nanoparticle like inclusion bodies in the intracellular space of algae was also detected. The findings were further substantiated by a detailed analysis of hydrodynamic stability, bioavailability and dissolution of ions from the nanoparticles over the exposure period. Altogether, the study brings out the first of its kind of observation of trophic transfer potential/behaviour of aluminium oxide nanoparticles and

Rtuť. Minulost a současnost tekutého kovu

Czech Academy of Sciences Publication Activity Database

Navrátil, Tomáš; Rohovec, Jan

2014-01-01

Roč. 93, 7-8 (2014), s. 430-437 ISSN 0042-4544 Institutional support: RVO:67985831 Keywords : mercury * chemistry * geochemistry * heavy metals * cinnabar * amalgam * toxic substances * toxicology * environmental pollution * mercury emissions * mercury deposition * mercury in soil * mercury in water * mercury in atmosphere * methylmercury * bioaccumulation * biomagnification Subject RIV: DD - Geochemistry http://casopis.vesmir.cz/clanek/rtut-minulost-a-soucasnost-tekuteho-kovu

Annual Report to Congress - Fiscal Year 2000, from the Strategic Environmental Research and Development Program

Science.gov (United States)

2001-03-01

parallel with bioslurry treatment and ecotoxicological testing, to show how the nature of PAH association with sediments relate to biostablization...correlated with toxicity endpoints (e.g., growth and reproduction) and biomagnification, with the ultimate goal of developing ecotoxicological parameters for...used to cultivate enhanced optimized m icroorganisms needed for a robust, high throughput biological process with performance, size and maintenance

User’s Manual for Strategic Satellite System Terminal Segment Life Cycle Cost Model. Volume 1

Science.gov (United States)

1981-03-01

the depot pipeline, given by: NFD(I) = EFAIL (I,NS)*TNB(NS) NS *1 [LRU(I) + RTS(NHI(1))]*NRTS(I)*DRCT(LO(NS)) + NRTS(NHI(i))*(l - COND(I))*DADI where... EFAIL (I,NS)*TNB(NS)* [(LRU(I) + RTS(NHI(I)))*NRTS(I) NS + NRTS(NHI(I))*(l-COND(I))] *DMH(I)*DMF where DMH(I) = averaRP marnours to perform depot...XJC - RSCA(I) + 12*PIUP* EFAIL (I,NS)*TNB(NS)* NS {(LRUCI)+RTS(NHI(I)))* (CR(I)*BIIH(I)*BMF*BLR + CN(I)*(DMH(I)*DMF*DLR + 2*CPPD(LOCNS))*WT(I)) + CC

Uptake studies of environmentally hazardous 51Cr in Mung beans

International Nuclear Information System (INIS)

Banerjee, Anupam; Nayak, Dalia; Chakrabortty, Dipanwita; Lahiri, Susanta

2008-01-01

Attempt has been made to study the accumulation behaviour of a common plant, Mung bean (Vigna radiata) towards Cr(III) and Cr(VI) to have an insight on the migration and bio-magnification of Cr. For this purpose healthy germinated Mung bean seeds were sown in the sand in the presence of Hoagland's nutrient solution containing measured amount of K 2 51 Cr 2 O 7 and 51 Cr(NO 3 ) 3 .9H 2 O. Growth rate was also studied in the presence and absence of phosphate salts in the medium. It has been found that the transfer of chromium from soil to plant is significantly low (maximum 5% for both Cr(III) and Cr(VI)). Maximum accumulation of Cr occurs in the root with respect to the total chromium accumulation by the plant. Other parts of the Mung bean plant, e.g. cotyledons, shoot and leaves, show negligible accumulation. Therefore, the chance of direct intake of Cr through food as well as through the grazing animals to human body is less. - The chance of bio-magnification of Cr(III) or Cr(VI) to human body via direct or indirect intake of Mung bean is negligible

Brominated flame retardants in birds of prey from Flanders, Belgium

Energy Technology Data Exchange (ETDEWEB)

Voorspoels, S.; Covaci, A.; Schepens, P. [Antwerp Univ., Wilrijk (Belgium). Toxicological Centre

2004-09-15

Since their introduction on the market, environmental levels of polybrominated diphenyl ethers (PBDEs) are continuously increasing. This is caused by spillage and emission during production and use, but also by improper disposal at the end-of-life of the products in which they are used. These chemicals are highly persistent and lipophilic which results in bioaccumulation in fatty tissues of biota and biomagnification throughout the food chain. Because PBDEs have a high toxicological potential, this biomagnification can have serious health consequences for top-predators, such as birds of prey. Data about PBDE concentrations in terrestrial biota, especially in birds of prey, is scarce. A rapid increase of PBDE concentrations has been seen in pooled guillemot (Uria algae) eggs from the Baltic proper7 during the late 1970's and early 1980's, followed by a decrease during the 1990's8. In herring gull eggs from the Great Lakes, the PBDE concentrations increased exponentially from 1981 to 2000. Most of the studies look at concentrations in eggs, while less is known about tissue levels and distribution of these pollutants in birds of prey.

Marine environment news. Vol. 3, no. 1, May 2005

International Nuclear Information System (INIS)

2005-06-01

This issue presents a guest article on selective biomagnification of metals and radionuclides in marine food chains. Major news items include that MEL joins the international study in South Pacific, inter-agency collaboration in the study of marine pollution, IAEA-UNESCO coordinate studies on submarine ground water discharge and collaborative research on nuclear and isotopic studies of the El Nino phenomenon launched in 2004

Marine environment news. Vol. 3, no. 1, May 2005

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-06-01

This issue presents a guest article on selective biomagnification of metals and radionuclides in marine food chains. Major news items include that MEL joins the international study in South Pacific, inter-agency collaboration in the study of marine pollution, IAEA-UNESCO coordinate studies on submarine ground water discharge and collaborative research on nuclear and isotopic studies of the El Nino phenomenon launched in 2004.

Cyclic volatile methylsiloxane bioaccumulation in flounder and ragworm in the Humber Estuary.

Science.gov (United States)

Kierkegaard, Amelie; van Egmond, Roger; McLachlan, Michael S

2011-07-15

Cyclic volatile methylsiloxanes are being subjected to regulatory scrutiny as possible PBT chemicals. The investigation of bioaccumulation has yielded apparently contradictory results, with high laboratory fish bioconcentration factors on the one hand and low field trophic magnification factors on the other. In this study, octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) were studied along with polychlorinated biphenyls (PCBs) in sediments, ragworm, and flounder from six sites in the Humber Estuary. Bioaccumulation was evaluated using multimedia bioaccumulation factors (mmBAFs) which quantified the fraction of the contaminant present in the aquatic environment that is transferred to the biota. PCB 180, a known strongly bioaccumulative chemical, was used as a benchmark. The mean mmBAF of D5 was about twice that of PCB 180 in both polycheates and flounder, while for D4 it was 6 and 14 times higher, respectively. The mmBAF of D6 was a factor 5-10 lower than that of PCB180. The comparatively strong multimedia bioaccumulation of D4 and D5, even in the absence of biomagnification, was explained by both compounds having a >100 times stronger tendency to partition into lipid rather than into organic carbon, while PCB 180 partitions to a similar extent into both matrices.

Differential mercury transfer in the aquatic food web of a double basined lake associated with selenium and habitat

International Nuclear Information System (INIS)

Arcagni, Marina; Campbell, Linda; Arribére, María A.; Marvin-DiPasquale, Mark; Rizzo, Andrea; Ribeiro Guevara, Sergio

2013-01-01

Food web trophodynamics of total mercury (THg) and selenium (Se) were assessed for the double-basined ultraoligotrophic system of Lake Moreno, Patagonia. Each basin has differing proportions of littoral and pelagic habitats, thereby providing an opportunity to assess the importance of habitat (e.g. food web structure or benthic MeHg production) in the transfer of Hg and Se to top trophic fish species. Pelagic plankton, analyzed in three size classes (10–53, 53–200, and > 200 μm), had very high [THg], exceeding 200 μg g −1 dry weight (DW) in the smallest, and a low ratio of MeHg to THg (0.1 to 3%). In contrast, [THg] in littoral macroinvertebrates showed lower values (0.3 to 1.8 μg g −1 DW). Juvenile and small fish species feeding upon plankton had higher [THg] (0.2 to 8 μg g −1 muscle DW) compared to large piscivore fish species (0.1 to 1.6 μg g −1 muscle DW). Selenium concentrations exhibited a much narrower variation range than THg in the food web, varying from 0.5 to 2.7 μg g −1 DW. Molar Se:Hg ratios exceeded 1 for the majority of organisms in both basins, with most ratios exceeding 10. Using stable nitrogen isotopes as indicator of trophic level, no significant correlations were found with [THg], [Se] or Se:Hg. The apparent lack of biomagnification trends was attributed to elevated [THg] in plankton in the inorganic form mostly, as well as the possibility of consistent Se supply reducing the biomagnification in the food web of the organic portion of THg. Highlights: • Mercury was studied in the food web of Lake Moreno, Nahuel Huapi National Park. • Mercury trophic transfer was assessed by nitrogen stable isotope (δ 15 N) analysis. • Selenium was determined showing consistent source in pelagic and littoral organisms. • High mercury concentrations, mostly inorganic, were determined in plankton. • No mercury biomagnification was observed in Lake Moreno food web

Pricing Volatility Referenced Assets

Directory of Open Access Journals (Sweden)

Alan De Genaro Dario

2006-12-01

Full Text Available Volatility swaps are contingent claims on future realized volatility. Variance swaps are similar instruments on future realized variance, the square of future realized volatility. Unlike a plain vanilla option, whose volatility exposure is contaminated by its asset price dependence, volatility and variance swaps provide a pure exposure to volatility alone. This article discusses the risk-neutral valuation of volatility and variance swaps based on the framework outlined in the Heston (1993 stochastic volatility model. Additionally, the Heston (1993 model is calibrated for foreign currency options traded at BMF and its parameters are used to price swaps on volatility and variance of the BRL / USD exchange rate.

Determining Steady-state Tissue Residues for Invertebrates in Contaminated Sediment

Science.gov (United States)

2010-05-01

meter (Thermo Orion Electron Corp., Beverly, MA) equipped with a 95-12 ammonia sensitive electrode (Thermo Orion Electron Corp., Beverly, MA...analyzed using an Agilent 5890 gas chromatograph with electron capture detection. Metals were analyzed following methods 6010B and 6020 using a Perkin...readily into cyto- plasm , making it a strong candidate for biomagnification up the food chain (Mason et al. 1996; Wiener et al. 2003). The BSAF

Sheeppox virus SPPV14 encodes a Bcl-2-like cell death inhibitor that counters a distinct set of mammalian proapoptotic proteins.

Science.gov (United States)

Okamoto, Toru; Campbell, Stephanie; Mehta, Ninad; Thibault, John; Colman, Peter M; Barry, Michele; Huang, David C S; Kvansakul, Marc

2012-11-01

Many viruses express inhibitors of programmed cell death (apoptosis), thereby countering host defenses that would otherwise rapidly clear infected cells. To counter this, viruses such as adenoviruses and herpesviruses express recognizable homologs of the mammalian prosurvival protein Bcl-2. In contrast, the majority of poxviruses lack viral Bcl-2 (vBcl-2) homologs that are readily identified by sequence similarities. One such virus, myxoma virus, which is the causative agent of myxomatosis, expresses a virulence factor that is a potent inhibitor of apoptosis. In spite of the scant sequence similarity to Bcl-2, myxoma virus M11L adopts an almost identical 3-dimensional fold. We used M11L as bait in a sequence similarity search for other Bcl-2-like proteins and identified six putative vBcl-2 proteins from poxviruses. Some are potent inhibitors of apoptosis, in particular sheeppox virus SPPV14, which inhibited cell death induced by multiple agents. Importantly, SPPV14 compensated for the loss of antiapoptotic F1L in vaccinia virus and acts to directly counter the cell death mediators Bax and Bak. SPPV14 also engages a unique subset of the death-promoting BH3-only ligands, including Bim, Puma, Bmf, and Hrk. This suggests that SPPV14 may have been selected for specific biological roles as a virulence factor for sheeppox virus.

miR-133a Enhances the Protective Capacity of Cardiac Progenitors Cells after Myocardial Infarction

Directory of Open Access Journals (Sweden)

Alberto Izarra

2014-12-01

Full Text Available miR-133a and miR-1 are known as muscle-specific microRNAs that are involved in cardiac development and pathophysiology. We have shown that both miR-1 and miR-133a are early and progressively upregulated during in vitro cardiac differentiation of adult cardiac progenitor cells (CPCs, but only miR-133a expression was enhanced under in vitro oxidative stress. miR-1 was demonstrated to favor differentiation of CPCs, whereas miR-133a overexpression protected CPCs against cell death, targeting, among others, the proapoptotic genes Bim and Bmf. miR-133a-CPCs clearly improved cardiac function in a rat myocardial infarction model by reducing fibrosis and hypertrophy and increasing vascularization and cardiomyocyte proliferation. The beneficial effects of miR-133a-CPCs seem to correlate with the upregulated expression of several relevant paracrine factors and the plausible cooperative secretion of miR-133a via exosomal transport. Finally, an in vitro heart muscle model confirmed the antiapoptotic effects of miR-133a-CPCs, favoring the structuration and contractile functionality of the artificial tissue.

Bioaccumulation of potentially toxic trace elements in benthic organisms of Admiralty Bay (King George Island, Antarctica)

International Nuclear Information System (INIS)

Majer, Alessandra Pereira; Petti, Mônica Angélica Varella; Corbisier, Thais Navajas; Ribeiro, Andreza Portella; Theophilo, Carolina Yume Sawamura; Ferreira, Paulo Alves de Lima; Figueira, Rubens Cesar Lopes

2014-01-01

Highlights: • Toxic metals were released in the 2012 fire in the Brazilian base at Admiralty Bay. • Potentially toxic metals were measured in eight Antarctic benthos species. • The bioaccumulation of As, Cd and Pb was verified in the studied species. • The biomagnification of Cd is suggested for the studied Antarctic food web. - Abstract: Data about the concentration, accumulation and transfer of potentially toxic elements in Antarctic marine food webs are essential for understanding the impacts of these elements, and for monitoring the pollution contribution of scientific stations, mainly in Admiralty Bay due to the 2012 fire in the Brazilian scientific station. Accordingly, the concentration of As, Cd, Cu, Ni, Pb and Zn was measured in eight benthic species collected in the 2005/2006 austral summer and the relationship between concentration and trophic position (indicated by δ 15 N values) was tested. A wide variation in metal content was observed depending on the species and the element. In the studied trophic positions, it was observed bioaccumulation for As, Cd and Pb, which are toxic elements with no biological function. In addition, Cd showed a positive relationship between concentration and trophic level suggesting the possible biomagnification of this element

Impacts of gold mine waste disposal on a tropical pelagic ecosystem

International Nuclear Information System (INIS)

Brewer, D.T.; Morello, E.B.; Griffiths, S.; Fry, G.; Heales, D.; Apte, S.C.; Venables, W.N.; Rothlisberg, P.C.; Moeseneder, C.; Lansdell, M.; Pendrey, R.; Coman, F.

2012-01-01

Highlights: ► We investigate the impact of gold mine tailings disposal into the sea. ► We use a comparative impact-control approach. ► Similar abundance and diversity of zooplankton and micronekton at mine and control. ► High metal concentrations and biomagnification evident in lower trophic levels only. ► No differences in metal concentrations of fish at mine and control. - Abstract: We used a comparative approach to investigate the impact of the disposal of gold mine tailings into the ocean near the Lihir mine (Niolam Island, Papua New Guinea). We found abundance and diversity of zooplankton, micronekton and pelagic fish to be similar or higher in the mine region compared to the reference site. We also found relatively high trace metal concentrations in lower trophic level groups, especially zooplankton, near the mine discharge, but few differences in tissue concentrations of micronekton, baitfish and pelagic fish between the two regions. Biomagnification of some trace metals by micronekton, and of mercury by fish was evident in both regions. We conclude that ocean mine waste disposal at Niolam Island has a local impact on the smaller and less mobile pelagic communities in terms of trace metal concentrations, but has little effect on the abundance and biodiversity of the local food web.

Uptake studies of environmentally hazardous {sup 51}Cr in Mung beans

Energy Technology Data Exchange (ETDEWEB)

Banerjee, Anupam [Department of Botany, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019 (India); Nayak, Dalia [Chemical Sciences Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Chakrabortty, Dipanwita [Sikkim Manipal University, A 15, Paryavaran Complex, New Delhi 110030 (India); Lahiri, Susanta [Chemical Sciences Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India)], E-mail: susanta.lahiri@saha.ac.in

2008-01-15

Attempt has been made to study the accumulation behaviour of a common plant, Mung bean (Vigna radiata) towards Cr(III) and Cr(VI) to have an insight on the migration and bio-magnification of Cr. For this purpose healthy germinated Mung bean seeds were sown in the sand in the presence of Hoagland's nutrient solution containing measured amount of K{sub 2}{sup 51}Cr{sub 2}O{sub 7} and {sup 51}Cr(NO{sub 3}){sub 3}.9H{sub 2}O. Growth rate was also studied in the presence and absence of phosphate salts in the medium. It has been found that the transfer of chromium from soil to plant is significantly low (maximum 5% for both Cr(III) and Cr(VI)). Maximum accumulation of Cr occurs in the root with respect to the total chromium accumulation by the plant. Other parts of the Mung bean plant, e.g. cotyledons, shoot and leaves, show negligible accumulation. Therefore, the chance of direct intake of Cr through food as well as through the grazing animals to human body is less. - The chance of bio-magnification of Cr(III) or Cr(VI) to human body via direct or indirect intake of Mung bean is negligible.

Lake Chapala, Mexico: lead distribution in water, sediment and bacteria; Escenarios de la distribucion de plomo en agua, sedimentos y bacterias del lago de Chapala, Mexico

Energy Technology Data Exchange (ETDEWEB)

Hansen, Anne M. [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico); Villa-Navia, Adriana [Interventor Ambiental de Occidental de Colombia, Inc. (Colombia); Afferden, Manfred van [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico)

2006-04-15

To evaluate the distribution of lead in the natural resources of lake Chapala, the adsorption of this metal in bacteria was analyzed and, through published data and the application of a chemical equilibrium model, the risk associated with the consumption of fish and water was estimated. Adsorption experiments of lead in three bacterial strains and simulations of the distribution of lead in the water-sediment-bacteria system indicate that the distribution of lead in the lake depends on variations of water quality such as suspended solids, lead and biomass concentrations. Considering only the lead contained in the bottom sediments, the simulations suggest that concentrations do not exceed the limits nor the criteria for use and protection of water, sediments, and biota. Considering an additional source of lead that locally increases the concentration by a factor of ten, the amount of lead in water and sediments may exceed these limits. The bioaccumulation of lead in lake Chapala was evaluated through calculation of bioconcentration and biomagnification factors, using simulated and published data on lead in fish (Ayla Jay y Ford, 2001). The results indicate that lead may be concentrated 721 and 6,195 times in bacteria and fish, respectively. Furthermore, bioaccumulation of lead in the lake may occur mainly as bioconcentration in fish rather than biomagnification in the food chain. [Spanish] Para evaluar la distribucion de plomo en los recursos naturales en el lago de Chapala se analizo la adsorcion de este metal en bacterias y, mediante datos publicados en la literatura y modelacion numerica, se estimo el riesgo asociado al consumo de peces y agua. Experimentos de adsorcion en tres cepas de bacterias y simulaciones de la distribucion en un sistema agua-sedimentos-bacterias indican que la distribucion del plomo en el lago depende de variaciones en calidad del agua tales como solidos suspendidos totales, plomo total y biomasa. Considerando unicamente el plomo contenido

Mercury in the food chain of the Lagoon of Venice, Italy.

Science.gov (United States)

Dominik, Janusz; Tagliapietra, Davide; Bravo, Andrea G; Sigovini, Marco; Spangenberg, Jorge E; Amouroux, David; Zonta, Roberto

2014-11-15

Sediments and biota samples were collected in a restricted area of the Lagoon of Venice and analysed for total mercury, monomethyl mercury (MMHg), and nitrogen and carbon isotopes. Results were used to examine mercury biomagnification in a complex food chain. Sedimentary organic matter (SOM) proved to be a major source of nutrients and mercury to primary consumers. Contrary to inorganic mercury, MMHg was strongly biomagnified along the food chain, although the lognormal relationship between MMHg and δ(15)N was less constrained than generally reported from lakes or coastal marine ecosystems. The relationship improved when logMMHg concentrations were plotted against trophic positions derived from baseline δ(15)N estimate for primary consumers. From the regression slope a mean MMHg trophic magnification factor of 10 was obtained. Filter-feeding benthic bivalves accumulated more MMHg than other primary consumers and were probably important in MMHg transfer from sediments to higher levels of the food chain. Copyright © 2014 Elsevier Ltd. All rights reserved.

From Midges to Spiders: Mercury Biotransport in Riparian Zones Near the Buffalo River Area of Concern (AOC), USA.

Science.gov (United States)

Pennuto, C M; Smith, M

2015-12-01

Riparian communities can receive environmental contaminants from adjacent aquatic 'donor' habitats. We investigated mercury biotransport from aquatic to terrestrial habitats via aquatic insect emergence and uptake by riparian spiders at sites within and upstream of the Buffalo River Area of Concern (AOC), a site with known sediment Hg contamination. Mercury concentration in emerging midges was roughly 10× less than contaminated sediment levels with the AOC, but biomagnification factors from midges to spiders ranged from 2.0 to 2.65 between sites. There was a significantly negative body mass:total mercury relationship in spiders (p Spiders contained significantly more mercury than their midge prey and spiders upstream of the AOC had higher mercury concentrations than spiders from within the AOC. Collectively, these data indicate that riparian spiders can be good mercury sentinels in urban environments, and that riparian communities upstream from the AOC may be at greater risk to mercury than has been previously considered.

Trophodynamics of mercury and other trace elements in a pelagic food chain from the Baltic Sea

International Nuclear Information System (INIS)

Nfon, Erick; Cousins, Ian T.; Jaervinen, Olli; Mukherjee, Arun B.; Verta, Matti; Broman, Dag

2009-01-01

Mercury (Hg) and 13 other trace elements (Al, Ti, V, Cr, Fe, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb) were measured in phytoplankton, zooplankton, mysis and herring in order to examine the trophodynamics in a well-studied pelagic food chain in the Baltic Sea. The fractionation of nitrogen isotopes (δ 15 N) was used to evaluate food web structure and to estimate the extent of trophic biomagnification of the various trace elements. Trophic magnification factors (TMFs) for each trace element were determined from the slope of the regression between trace element concentrations and δ 15 N. Calculated TMFs showed fundamental differences in the trophodynamics of the trace elements in the pelagic food chain studied. Concentrations of Al, Fe, Ni, Zn, Pb and Cd showed statistically significant decreases (TMF 1) in concentration with trophic level i.e. Hg biomagnifies in this Baltic food chain. The estimated TMF for Hg in this food chain was comparable to TMFs observed elsewhere for diverse food chains and locations.

Mercury, cadmium and lead concentrations in different ecophysiological groups of earthworms in forest soils

International Nuclear Information System (INIS)

Ernst, Gregor; Zimmermann, Stefan; Christie, Peter; Frey, Beat

2008-01-01

Bioaccumulation of Hg, Cd and Pb by eight ecophysiologically distinct earthworm species was studied in 27 polluted and uncontaminated forest soils. Lowest tissue concentrations of Hg and Cd occurred in epigeic Lumbricus rubellus and highest in endogeic Octolasion cyaneum. Soils dominated by Dendrodrilus rubidus possess a high potential of risk of Pb biomagnification for secondary predators. Bioconcentration factors (soil-earthworm) followed the sequence ranked Cd > Hg > Pb. Ordination plots of redundancy analysis were used to compare HM concentrations in earthworm tissues with soil, leaf litter and root concentrations and with soil pH and CEC. Different ecological categories of earthworms are exposed to Hg, Cd and Pb in the topsoil by atmospheric deposition and accumulate them in their bodies. Species differences in HM concentrations largely reflect differences in food selectivity and niche separation. - Accumulation of non-essential heavy metals by earthworms is species-dependent and is affected by soil characteristics in natural forest soils

Technical Review Report for the Model 9975-96 Package Safety Analysis Report for Packaging (S-SARP-G-00003, Revision 0, January 2008)

International Nuclear Information System (INIS)

West, M.

2009-01-01

This Technical Review Report (TRR) documents the review, performed by the Lawrence Livermore National Laboratory (LLNL) Staff, at the request of the U.S. Department of Energy (DOE), on the Safety Analysis Report for Packaging, Model 9975, Revision 0, dated January 2008 (S-SARP-G-00003, the SARP). The review includes an evaluation of the SARP, with respect to the requirements specified in 10 CFR 71, and in International Atomic Energy Agency (IAEA) Safety Standards Series No. TS-R-1. The Model 9975-96 Package is a 35-gallon drum package design that has evolved from a family of packages designed by DOE contractors at the Savannah River Site. Earlier package designs, i.e., the Model 9965, the Model 9966, the Model 9967, and the Model 9968 Packagings, were originally designed and certified in the early 1980s. In the 1990s, updated package designs that incorporated design features consistent with the then newer safety requirements were proposed. The updated package designs at the time were the Model 9972, the Model 9973, the Model 9974, and the Model 9975 Packagings, respectively. The Model 9975 Package was certified by the Packaging Certification Program, under the Office of Safety Management and Operations. The safety analysis of the Model 9975-85 Packaging is documented in the Safety Analysis Report for Packaging, Model 9975, B(M)F-85, Revision 0, dated December 2003. The Model 9975-85 Package is certified by DOE Certificate of Compliance (CoC) package identification number, USA/9975/B(M)F-85, for the transportation of Type B quantities of uranium metal/oxide, 238 Pu heat sources, plutonium/uranium metals, plutonium/uranium oxides, plutonium composites, plutonium/tantalum composites, 238 Pu oxide/beryllium metal.

Differential mercury transfer in the aquatic food web of a double basined lake associated with selenium and habitat

Energy Technology Data Exchange (ETDEWEB)

Arcagni, Marina [Laboratorio de Análisis por Activación Neutrónica, Centro Atómico Bariloche, CNEA, Av. Bustillo km 9.5, 8400 Bariloche (Argentina); Campbell, Linda [Faculty of Science, Saint Mary' s University, 923 Robie Street, Halifax, Nova Scotia B3H 3C3 (Canada); Arribére, María A. [Laboratorio de Análisis por Activación Neutrónica, Centro Atómico Bariloche, CNEA, Av. Bustillo km 9.5, 8400 Bariloche (Argentina); Instituto Balseiro, Universidad Nacional de Cuyo and Comisión Nacional de Energía Atómica (Argentina); Marvin-DiPasquale, Mark [U.S. Geological Survey, 345 Middlefield Rd./MS 480, Menlo Park, CA 94025 (United States); Rizzo, Andrea [Laboratorio de Análisis por Activación Neutrónica, Centro Atómico Bariloche, CNEA, Av. Bustillo km 9.5, 8400 Bariloche (Argentina); CONICET (Argentina); Ribeiro Guevara, Sergio, E-mail: ribeiro@cab.cnea.gov.ar [Laboratorio de Análisis por Activación Neutrónica, Centro Atómico Bariloche, CNEA, Av. Bustillo km 9.5, 8400 Bariloche (Argentina)

2013-06-01

Food web trophodynamics of total mercury (THg) and selenium (Se) were assessed for the double-basined ultraoligotrophic system of Lake Moreno, Patagonia. Each basin has differing proportions of littoral and pelagic habitats, thereby providing an opportunity to assess the importance of habitat (e.g. food web structure or benthic MeHg production) in the transfer of Hg and Se to top trophic fish species. Pelagic plankton, analyzed in three size classes (10–53, 53–200, and > 200 μm), had very high [THg], exceeding 200 μg g{sup −1} dry weight (DW) in the smallest, and a low ratio of MeHg to THg (0.1 to 3%). In contrast, [THg] in littoral macroinvertebrates showed lower values (0.3 to 1.8 μg g{sup −1} DW). Juvenile and small fish species feeding upon plankton had higher [THg] (0.2 to 8 μg g{sup −1} muscle DW) compared to large piscivore fish species (0.1 to 1.6 μg g{sup −1} muscle DW). Selenium concentrations exhibited a much narrower variation range than THg in the food web, varying from 0.5 to 2.7 μg g{sup −1} DW. Molar Se:Hg ratios exceeded 1 for the majority of organisms in both basins, with most ratios exceeding 10. Using stable nitrogen isotopes as indicator of trophic level, no significant correlations were found with [THg], [Se] or Se:Hg. The apparent lack of biomagnification trends was attributed to elevated [THg] in plankton in the inorganic form mostly, as well as the possibility of consistent Se supply reducing the biomagnification in the food web of the organic portion of THg. Highlights: • Mercury was studied in the food web of Lake Moreno, Nahuel Huapi National Park. • Mercury trophic transfer was assessed by nitrogen stable isotope (δ{sup 15}N) analysis. • Selenium was determined showing consistent source in pelagic and littoral organisms. • High mercury concentrations, mostly inorganic, were determined in plankton. • No mercury biomagnification was observed in Lake Moreno food web.

Cesium accumulation by aquatic organisms at different trophic levels following an experimental release into a small reservoir

Energy Technology Data Exchange (ETDEWEB)

Pinder, J.E., E-mail: jepinder@uga.ed [Savannah River Ecology Laboratory, P. O. Drawer E, Aiken, SC 29802 (United States); Hinton, T.G., E-mail: thomas.hinton@irsn.f [Savannah River Ecology Laboratory, P. O. Drawer E, Aiken, SC 29802 (United States); Taylor, B.E., E-mail: TaylorB@dnr.sc.go [Savannah River Ecology Laboratory, P. O. Drawer E, Aiken, SC 29802 (United States); Whicker, F.W., E-mail: ward.whicker@colostate.ed [Department of Environmental and Radiological Health Sciences, Colorado, State University, Fort Collins, CO 80523-1618 (United States)

2011-03-15

The rates of accumulation and subsequent loss of stable cesium ({sup 133}Cs) by organisms at different trophic levels within plankton-based and periphyton-based food chains were measured following the addition of {sup 133}Cs into a small reservoir near Aiken, South Carolina, USA. An uptake parameter u (L kg{sup -1} d{sup -1} dry mass) and a loss rate parameter k (d{sup -1}) were estimated for each organism using time-series measurements of {sup 133}Cs concentrations in water and biota, and these parameters were used to estimate maximum concentrations, times to maximum concentrations, and concentration ratios (C{sub r}). The maximum {sup 133}Cs concentrations for plankton, periphyton, the insect larva Chaoborus punctipennis, which feeds on plankton, and the snail Helisoma trivolvis, which feeds on periphyton, occurred within the first 14 days following the addition, whereas the maximum concentrations for the fish species Lepomis macrochirus and Micropterus salmoides occurred after 170 days. The C{sub r} based on dry mass for plankton and C. punctipennis were 1220 L kg{sup -1} and 5570 L kg{sup -1}, respectively, and were less than the C{sub r} of 8630 L kg{sup -1} for periphyton and 47,700 L kg{sup -1} for H. trivolvis. Although the C{sub r} differed between plankton-based and periphyton-based food chains, they displayed similar levels of biomagnification. Biomagnification was also indicated for fish where the C{sub r} for the mostly nonpiscivorous L. macrochirus of 22,600 L kg{sup -1} was three times less than that for mostly piscivorous M. salmoides of 71,500 L kg{sup -1}. Although the C{sub r} for M. salmoides was greater than those for periphyton and H. trivolvis, the maximum {sup 133}Cs concentrations for periphyton and H. trivolvis were greater than that for M. salmoides. - Research highlights: {yields} A simple uptake and loss model described the Cs dynamics in all the various biota. {yields} Concentrations of Cs were greater in periphyton than in plankton

Production of the Neurotoxin BMAA by a Marine Cyanobacterium

Directory of Open Access Journals (Sweden)

Paul Alan Cox

2007-12-01

Full Text Available Diverse species of cyanobacteria have recently been discovered to produce theneurotoxic non-protein amino acid β-methylamino-L-alanine (BMAA. In Guam, BMAAhas been studied as a possible environmental toxin in the diets of indigenous Chamorropeople known to have high levels of Amyotrophic Lateral Sclerosis/ ParkinsonismDementia Complex (ALS/PDC. BMAA has been found to accumulate in brain tissues ofpatients with progressive neurodegenerative illness in North America. In Guam, BMAAwas found to be produced by endosymbiotic cyanobacteria of the genus Nostoc which livein specialized cycad roots. We here report detection of BMAA in laboratory cultures of afree-living marine species of Nostoc. We successfully detected BMAA in this marinespecies of Nostoc with five different methods: HPLC-FD, UPLC-UV, Amino AcidAnalyzer, LC/MS, and Triple Quadrupole LC/MS/MS. This consensus of five differentanalytical methods unequivocally demonstrates the presence of BMAA in this marinecyanobacterium. Since protein-associated BMAA can accumulate in increasing levelswithin food chains, it is possible that biomagnification of BMAA could occur in marineecosystems similar to the biomagnification of BMAA in terrestrial ecosystems. Productionof BMAA by marine cyanobacteria may represent another route of human exposure toBMAA. Since BMAA at low concentrations causes the death of motor neurons, low levelsof BMAA exposure may trigger motor neuron disease in genetically vulnerableindividuals.

Metamorphosis alters contaminants and chemical tracers in insects: implications for food webs.

Science.gov (United States)

Kraus, Johanna M; Walters, David M; Wesner, Jeff S; Stricker, Craig A; Schmidt, Travis S; Zuellig, Robert E

2014-09-16

Insects are integral to most freshwater and terrestrial food webs, but due to their accumulation of environmental pollutants they are also contaminant vectors that threaten reproduction, development, and survival of consumers. Metamorphosis from larvae to adult can cause large chemical changes in insects, altering contaminant concentrations and fractionation of chemical tracers used to establish contaminant biomagnification in food webs, but no framework exists for predicting and managing these effects. We analyzed data from 39 studies of 68 analytes (stable isotopes and contaminants), and found that metamorphosis effects varied greatly. δ(15)N, widely used to estimate relative trophic position in biomagnification studies, was enriched by ∼ 1‰ during metamorphosis, while δ(13)C used to estimate diet, was similar in larvae and adults. Metals and polycyclic aromatic hydrocarbons (PAHs) were predominantly lost during metamorphosis leading to ∼ 2 to 125-fold higher larval concentrations and higher exposure risks for predators of larvae compared to predators of adults. In contrast, manufactured organic contaminants (such as polychlorinated biphenyls) were retained and concentrated in adults, causing up to ∼ 3-fold higher adult concentrations and higher exposure risks to predators of adult insects. Both food web studies and contaminant management and mitigation strategies need to consider how metamorphosis affects the movement of materials between habitats and ecosystems, with special regard for aquatic-terrestrial linkages.

Mercury speciation in coastal sediments from the central east coast of India by modified BCR method.

Digital Repository Service at National Institute of Oceanography (India)

Chakraborty, P.; Babu, P.V.R.; Vudamala, K.; Ramteke, D.; Chennuri, K.

pervasiveness and adverse effects on wildlife and human health (US EPA, 1997). The high biomagnifications rate of Hg in food chain, makes this metal of the most environmental concern (Fitzgerald et al., 2007; Morel et al., 1998). Global oceans, coastal zones... been reported that coastal sediments act both as a sink and source for toxic metals (Chakraborty et al., 2012b). Sediment contamination in the coastal areas is a major environmental issue because of its potential toxic effects on biological resources...

Chemical speciation and transformation of mercury in contaminated sediments

OpenAIRE

Drott, Andreas

2009-01-01

Biomagnification of mercury (Hg) in aquatic food webs occurs almost exclusively as mono-methyl Hg (MeHg). In this thesis, the influence of chemical speciation and environmental conditions on transformations of inorganic Hg (HgII) and MeHg was studied at eight sites in Sweden with Hg contaminated sediments. The source of contamination was either Hg0(l) or phenyl-Hg, and total Hg concentrations ranged between 1.0-1100 nmol g-1. The environmental conditions, e.g. salinity, temperature climate, p...

Relativistic mean field theory for deformed nuclei with pairing correlations

International Nuclear Information System (INIS)

Geng, Lisheng; Toki, Hiroshi; Sugimoto, Satoru; Meng, Jie

2003-01-01

We develop a relativistic mean field (RMF) description of deformed nuclei with pairing correlations in the BCS approximation. The treatment of the pairing correlations for nuclei whose Fermi surfaces are close to the threshold of unbound states needs special attention. With this in mind, we use a delta function interaction for the pairing interaction to pick up those states whose wave functions are concentrated in the nuclear region and employ the standard BCS approximation for the single-particle states obtained from the BMF theory with deformation. We apply the RMF + BCS method to the Zr isotopes and obtain a good description of the binding energies and the nuclear radii of nuclei from the proton drip line to the neutron drip line. (author)

The potential of ball-milled South African bentonite clay for attenuation of heavy metals from acidic wastewaters: Simultaneous sorption of Co(sup2+), Cu(sup2+), Ni(sup2+), Pb(sup2+), and Zn(sup2+) ions

CSIR Research Space (South Africa)

Vhahangwele, M

2015-12-01

Full Text Available Mohd Pauzi, N. U. R., and Mutalib, H. A. (2009). "Acid mine drainage and heavy metals contamination at abandoned and active mine sites in Pahang." Bulletin of the Geological Society of Malaysia(55), 15-20. [4] Zou, G., Ylinen, A., Di Capua, F. D... to their non-biodegradable nature, heavy metals can bio-accumulate in living organisms and bio-magnification through the food chain. Toxic levels of metal species in the biosphere can also be released into water and soil fluids through natural...

Biomass reduction of Salvinia molesta exposed to copper sulfate pentahydrate (CuSO4.5H2O)

OpenAIRE

Barros,João Pedro Alves de Azevedo; Henares,Matheus Nicolino Peixoto

2015-01-01

Copper in the aquatic ecosystem may remain adsorbed or be incorporated into the biomass and undergo biomagnification causing unwanted effects to aquatic macrophyte communities. This study evaluated the biomass reduction of Salvinia molesta (Mitchell) exposed to copper sulphate pentahydrate (CuSO4.5H2O) under laboratory conditions. Approximately 20.5 g of fresh mass (FM) of S. molesta (0.74 g dry matter, DM) were placed in glass tanks with different concentrations (n = 3) of CuSO4.5H2O as foll...

Interactions of radionuclides with marine biota

International Nuclear Information System (INIS)

Small, L.F.

1997-01-01

Uptake of radioactivity by marine biota can occur through consumption of radioactive food or via direct incorporation from the seawater. As uptake occurs, radioactivity begins to distribute into and onto various body tissues, or ''compartments'', at different rates. A composite uptake curve therefore is curvilinear with time. Elimination can occur via various pathways, including fecal deposition, molting, and excretion of dissolved substances, and therefore a composite loss curve also is curvilinear. Uptake and elimination can occur simultaneously, and under constant conditions over a long time period a steady-state body burden will be achieved. Many factors can affect uptake and loss rates, as well as steady-state body burdens, and some major ones are discussed. Design of radioactivity experiments involving marine biota is explored, and a case study of a ''natural experiment'' involving both reactor-produced and fallout radionuclides in a coastal environment is presented to show how much nuclide introductions can be used to learn about nuclide biomagnification, trophic level relationships, and biological distribution of radioactivity in the sea. (author)

Uptake, absorption efficiency and elimination of DDT in marine phytoplankton, copepods and fish

International Nuclear Information System (INIS)

Wang Xinhong; Wang Wenxiong

2005-01-01

Uptake, absorption efficiency and elimination of DDT were measured in marine phytoplankton, copepods (Acartia erythraea) and fish (mangrove snappers Lutjanus argentimaculatus). The uptake rate constant of DDT from water decreased with increasing trophic level. The dietary absorption efficiency (AE) of DDT was 10-29% in copepods and 72-99% in fish. Food concentration did not significantly affect the AEs of DDT, but the AEs varied considerably among the different food diets. The elimination rate constants of DDT by the copepods were comparable following uptake from the diet and from the water. Elimination of DDT from the fish was exceedingly low. Both aqueous and dietary uptake are equally important for DDT accumulation in the copepods. In fish, dissolved exposure is a more significant route than intake from the diet. The predicted trophic transfer factors in the copepods and the fish are consistent with the field measurements in marine zooplankton and fish. -Biomagnification and exposure of DDT in a marine food chain is demonstrated by measurements of uptake and elimination rates and kinetic modeling

Mercury and cadmium in ringed seals in the Canadian Arctic: Influence of location and diet

Energy Technology Data Exchange (ETDEWEB)

Brown, Tanya M., E-mail: tanya.brown@mun.ca [Memorial University of Newfoundland, St. John' s, Newfoundland A1B 3X9 (Canada); Fisk, Aaron T. [Great Lakes Institute of Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, Ontario N9B 3P4 (Canada); Wang, Xiaowa [Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario L7R 4A6 (Canada); Ferguson, Steven H. [Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba R3T 2N6 (Canada); Young, Brent G. [University of Manitoba, 500 University Crescent, Winnipeg, Manitoba R3T 2N2 (Canada); Reimer, Ken J. [Environmental Sciences Group, Royal Military College of Canada, PO Box 17000, Stn Forces, Kingston, Ontario K7K 7B4 (Canada); Muir, Derek C.G. [Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario L7R 4A6 (Canada)

2016-03-01

Concentrations of total mercury (THg) and total cadmium (TCd) were determined in muscle and liver of ringed seals (Pusa hispida) from up to 14 locations across the Canadian Arctic. Location, trophic position (TP) and relative carbon source best predicted the THg and TCd concentrations in ringed seals. THg concentrations in ringed seals were highest in the western Canadian Arctic (Beaufort Sea), whereas TCd was highest in the eastern Canadian Arctic (Hudson Bay and Labrador). A positive relationship between THg and TP and a negative relationship between THg and relative carbon source contributed to the geographical patterns observed and elevated THg levels at certain sites. In contrast, a negative relationship between TCd and TP was found, indicating that high TCd concentrations are related to seals feeding more on invertebrates than fish. Feeding ecology appears to play an important role in THg and TCd levels in ringed seals, with biomagnification driving elevated THg levels and a dependence on low-trophic position prey resulting in high TCd concentrations. The present study shows that both natural geological differences and diet variability among regions explain the spatial patterns for THg and TCd concentrations in ringed seals. - Highlights: • Diet and location influenced THg and Cd in ringed seals across the Canadian Arctic. • Biomagnification processes contribute to elevated THg levels in the western Arctic. • Consuming low-trophic position prey explains high Cd levels in the eastern Arctic.

Somatic and gastrointestinal in vivo biotransformation rates of hydrophobic chemicals in fish.

Science.gov (United States)

Lo, Justin C; Campbell, David A; Kennedy, Christopher J; Gobas, Frank A P C

2015-10-01

To improve current bioaccumulation assessment methods, a methodology is developed, applied, and investigated for measuring in vivo biotransformation rates of hydrophobic organic substances in the body (soma) and gastrointestinal tract of the fish. The method resembles the Organisation for Economic Co-operation and Development (OECD) 305 dietary bioaccumulation test but includes reference chemicals to determine both somatic and gastrointestinal biotransformation rates of test chemicals. Somatic biotransformation rate constants for the test chemicals ranged between 0 d(-1) and 0.38 (standard error [SE] 0.03)/d(-1) . Gastrointestinal biotransformation rate constants varied from 0 d(-1) to 46 (SE 7) d(-1) . Gastrointestinal biotransformation contributed more to the overall biotransformation in fish than somatic biotransformation for all test substances but 1. Results suggest that biomagnification tests can reveal the full extent of biotransformation in fish. The common presumption that the liver is the main site of biotransformation may not apply to many substances exposed through the diet. The results suggest that the application of quantitative structure-activity relationships (QSARs) for somatic biotransformation rates and hepatic in vitro models to assess the effect of biotransformation on bioaccumulation can underestimate biotransformation rates and overestimate the biomagnification potential of chemicals that are biotransformed in the gastrointestinal tract. With some modifications, the OECD 305 test can generate somatic and gastrointestinal biotransformation data to develop biotransformation QSARs and test in vitro-in vivo biotransformation extrapolation methods. © 2015 SETAC.

Mercury and cadmium in ringed seals in the Canadian Arctic: Influence of location and diet

International Nuclear Information System (INIS)

Brown, Tanya M.; Fisk, Aaron T.; Wang, Xiaowa; Ferguson, Steven H.; Young, Brent G.; Reimer, Ken J.; Muir, Derek C.G.

2016-01-01

Concentrations of total mercury (THg) and total cadmium (TCd) were determined in muscle and liver of ringed seals (Pusa hispida) from up to 14 locations across the Canadian Arctic. Location, trophic position (TP) and relative carbon source best predicted the THg and TCd concentrations in ringed seals. THg concentrations in ringed seals were highest in the western Canadian Arctic (Beaufort Sea), whereas TCd was highest in the eastern Canadian Arctic (Hudson Bay and Labrador). A positive relationship between THg and TP and a negative relationship between THg and relative carbon source contributed to the geographical patterns observed and elevated THg levels at certain sites. In contrast, a negative relationship between TCd and TP was found, indicating that high TCd concentrations are related to seals feeding more on invertebrates than fish. Feeding ecology appears to play an important role in THg and TCd levels in ringed seals, with biomagnification driving elevated THg levels and a dependence on low-trophic position prey resulting in high TCd concentrations. The present study shows that both natural geological differences and diet variability among regions explain the spatial patterns for THg and TCd concentrations in ringed seals. - Highlights: • Diet and location influenced THg and Cd in ringed seals across the Canadian Arctic. • Biomagnification processes contribute to elevated THg levels in the western Arctic. • Consuming low-trophic position prey explains high Cd levels in the eastern Arctic.

Large-scale spatial and interspecies differences in trace elements and stable isotopes in marine wild fish from Chinese waters

International Nuclear Information System (INIS)

Zhang, Wei; Wang, Wen-Xiong

2012-01-01

Highlights: ► A large-scale study on trace element levels in marine wild fish from Chinese waters. ► Spatial variation found for Al, As, Cd, Cr, Fe, Ni, Pb, but not for Ag, Cu, Mo, Se and Zn. ► The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb. ► No biomagnification occurred for any of the trace elements studied in marine fish. ► No obvious health risk from the intake of trace elements through fish consumption. - Abstract: We conducted a large scale investigation of twelve trace element levels and stable isotopes (δ 13 C and δ 15 N) in twenty-nine marine wild fish species collected from Chinese coastal waters. Trace element levels varied significantly with species. Clear spatial variations were found for Al, As, Cd, Cr, Fe, Ni, and Pb, whereas Ag, Cu, Mo, Se and Zn did not show much spatial variation. The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb, whereas the most southern waters (Haikou) contained the lowest concentrations of Al, Fe, and Pb. There was no correlation between log-transformed trace elements concentrations and δ 15 N values or δ 13 C values, indicating no biomagnification among these trace elements. The calculated hazard quotients (HQ) of 10 elements were less than 1, thus there was no obvious health risk from the intake of trace elements through marine wild fish consumption.

Preços futuros do café: uma análise de cointegração entre o preço interno e o preço externo

Directory of Open Access Journals (Sweden)

Marcelo A. Arbex

2013-12-01

Full Text Available O Brasil ainda é o maior produtor mundial de café, porém não ocupa mais a posição de semi-monopolista no mercado internacional. Por conta de uma política de sustentação de preços no mercado mundial, o Brasil involuntariamente incentivou concorrentes e, conseqüentemente, perdeu a hegemonia que até então possuía. A convergência dos maiores produtores de café para o mercado norte-americano, grande consumidor de café, torna os mercados à vista e futuro mais atrativos nesse país. A grande presença de hedgers e especuladores na CSCE, em Nova York, faz com que o contrato futuro de café negociado nessa bolsa de mercadorias tenha uma elevada liquidez, tornando esse mercado ainda mais atrativo para os agentes que negociam tal commodity. Analisando o comportamento dos preços futuros internos, cotados na BM&F, e externos do café, é possível observar que eles possuem um comportamento semelhante no período compreendido entre agosto de 1991 e junho de 1996. Outra observação interessante é que as elevações e quedas de preço do contrato futuro de café negociado na BM&F ocorrem após as elevações e quedas dos preços cotados na CSCE. Através da análise de cointegração, é possível verificar que existe uma relação de equilíbrio de longo prazo entre os preços futuros de café internos e externos. A dinâmica de curto prazo entre essas duas variáveis apresenta um desequilíbrio, o qual é corrigido por mecanismo de correção de erro, de forma que o comportamento dessas séries caminhe em direção ao equilíbrio de longo prazo.

Bioavailability of sediment-bound contaminants to marine organisms

Energy Technology Data Exchange (ETDEWEB)

Brown, B. [Battelle/Marine Sciences Lab., Sequim, WA (United States)]|[Colby Coll., Waterville, ME (United States); Neff, J. [Battelle/Marine Sciences Lab., Sequim, WA (United States)]|[Battelle Ocean Sciences, Duxbury, MA (United States)

1993-09-01

The bioavailability of sediment-bound contaminants to marine organisms indicates that there exists a potential for transfer of these contaminants through marine food webs to commercial fisheries products consumed by humans. However, there has been relatively little effort to combine and synthesize data on chemical/biological interactions between benthic animals and seagrasses and the sediments in which they reside on the one hand, and on the chemistry of bioaccumulation on the other. This report provides a conceptual basis for an approach to bioavailability and biomagnification of sediment-bound contaminants that reviews biological and chemical approaches.

Basic concepts in marine biology and ecology

International Nuclear Information System (INIS)

Small, L.F.

1997-01-01

An introduction to the marine biota, and how the biota interact with their physico-chemical environment, is given in this chapter. In particular, food web and trophic level relationships are discussed, from phytopIankton production through consumer organisms and the ''microbial loop''. The effects of organism size and functional relationships within the food web paradigm are emphasized, rather than taxonomic relationships. Examples initially given in terms of carbon, nitrogen, or energy transfer through food webs are placed in context with radionuclide transfer and the concept of biomagnification. (author)

Development of Ecological Toxicity and Biomagnification Data for Explosives Contaminants in Soil

Science.gov (United States)

2003-07-01

could develop at 500 mg kg-1 TNT in soil. Winfield et al. (1999) found that sunflower and sanfroin were the most sensitive species among ten species...up to 4000 mg kg-1 soil) during early life stage resulted in adverse responses in sensitive terrestrial plants such as sunflower and sanfroin. Bean...plants (Harvey et al., 1991; Best et al., 1999; Groom et al., 2002). Therefore, phytoremediation is a potential route for removing these EMs from soil

Utilisation of 2nd generation web technologies in master level vocational teacher training

Directory of Open Access Journals (Sweden)

Péter Tóth

2009-03-01

Full Text Available The Masters level Opportunities and Technological Innovation in Vocational Teacher Education project (project site: http://motivate.tmpk.bmf.hu/ aims to develop the use and management of virtual learning environments in the area of vocational teacher training, drawing on a well established international partnership of institutions providing both technical and educational expertise. This paper gives an overall picture of the first results and products of the collaboration. We touch upon the goals, the assessments and the learning process of using “Multimedia and e-Learning: e-learning methods and tools” module in details. The main cooperative and collaborative devices are presented in virtual learning environment. The communication during collaborative learning, the structured debate on forum and the benefits of collaborative learning in VLE are interpreted at the end of this paper.

Hermeticity control system for the BMS/BMF-MDT chambers of the muon spectrometer of ATLAS experiment

International Nuclear Information System (INIS)

Barashkov, A.V.; Glonti, G.L.; Gongadze, A.L.; Dedovich, D.V.; Demichev, M.A.; Zhemchugov, A.S.; Il'yushenko, E.N.; Korolevich, Ya.V.; Kruchonok, V.G.; Lomidze, D.D.; Nikolaev, K.V.; Kharchenko, D.V.; Tskhadadze, Eh.G.; Chepurnov, V.F.; Shelkov, G.A.; Shcherbakov, A.A.

2005-01-01

Description of hermeticity certification of the JINR made muon chambers for the ATLAS experiment is presented. A high precision stand was installed in the production area of the DLNP, JINR. The description of the stand and results of the measurements and the description and results of the second testing of the drift chambers carried out after transportation to CERN are presented

Transfer of mercury and methylmercury along macroinvertebrate food chains in a floodplain lake of the Beni River, Bolivian Amazonia

International Nuclear Information System (INIS)

Molina, Carlos Israel; Gibon, Francois-Marie; Duprey, Jean-Louis; Dominguez, Eduardo; Guimaraes, Jean-Remy D.; Roulet, Marc

2010-01-01

We have evaluated the mercury and methylmercury transfers to and within the macroinvertebrate communities of a floodplain lake of the Beni River basin, Bolivia, during three hydrological seasons and in two habitats (open water and vegetation belt). Using the stable isotopes δ 13 C and δ 15 N, six trophic chains were identified during a previous study. Four are based on only one source: seston, organic matter from the bottom sediment, periphyton and macrophytes. Two are based on mixed sources (seston and periphyton in one case, periphyton and macrophytes in the other). During sampling, we found only one taxon that had surface sediment organic matter as food source and very few taxa whose trophic source was constituted by macrophytes. The periphyton was the most important source during all seasons; it produced the longest chain, with three trophic positions. Whatever the season and trophic source, all collected macroinvertebrates contained methyl mercury and the latter was biomagnified in all trophic chains that we identified. The biomagnification of methylmercury through invertebrate trophic chains accurately reflected the existence and length of these chains. Biomagnification was virtually non-existent in the sediment-based chain, low and restricted to the dry season in the macrophyte-based chain. It was significant in the seston-based chain, but limited by the existence of only two trophic levels and restricted to the wet season. Finally, it was very effective in the periphyton-based chain, which offers the highest rate of contamination of the source but, above all, the largest number of trophic levels.

Transfer of mercury and methylmercury along macroinvertebrate food chains in a floodplain lake of the Beni River, Bolivian Amazonia

Energy Technology Data Exchange (ETDEWEB)

Molina, Carlos Israel, E-mail: camoar6088@gmail.com [Instituto de Ecologia, Unidad de Limnologia, UMSA, Casilla postal 10077, La Paz (Bolivia, Plurinational State of); Institut de Recherche pour le Developpement IRD, Casilla postal 9214, La Paz (Bolivia, Plurinational State of); CONICET-Facultad de Ciencias Naturales, Universidad Nacional de Tucuman, Miguel Lillo 205, 4 000, Tucuman (Argentina); Gibon, Francois-Marie [Institut de Recherche pour le Developpement IRD, Casilla postal 9214, La Paz (Bolivia, Plurinational State of); IRD, UMR BOREA, Museum national d' Histoire Naturelle MNHN, Case postale 26, 75231, Paris cedex 05 (France); Duprey, Jean-Louis [Institut de Recherche pour le Developpement IRD, Casilla postal 9214, La Paz (Bolivia, Plurinational State of); Dominguez, Eduardo [CONICET-Facultad de Ciencias Naturales, Universidad Nacional de Tucuman, Miguel Lillo 205, 4 000, Tucuman (Argentina); Guimaraes, Jean-Remy D. [Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Bloco G-CCS, Rio de Janeiro, CEP 21949-900 (Brazil); Roulet, Marc [Institut de Recherche pour le Developpement IRD, Casilla postal 9214, La Paz (Bolivia, Plurinational State of)

2010-07-15

We have evaluated the mercury and methylmercury transfers to and within the macroinvertebrate communities of a floodplain lake of the Beni River basin, Bolivia, during three hydrological seasons and in two habitats (open water and vegetation belt). Using the stable isotopes {delta}{sup 13}C and {delta}{sup 15}N, six trophic chains were identified during a previous study. Four are based on only one source: seston, organic matter from the bottom sediment, periphyton and macrophytes. Two are based on mixed sources (seston and periphyton in one case, periphyton and macrophytes in the other). During sampling, we found only one taxon that had surface sediment organic matter as food source and very few taxa whose trophic source was constituted by macrophytes. The periphyton was the most important source during all seasons; it produced the longest chain, with three trophic positions. Whatever the season and trophic source, all collected macroinvertebrates contained methyl mercury and the latter was biomagnified in all trophic chains that we identified. The biomagnification of methylmercury through invertebrate trophic chains accurately reflected the existence and length of these chains. Biomagnification was virtually non-existent in the sediment-based chain, low and restricted to the dry season in the macrophyte-based chain. It was significant in the seston-based chain, but limited by the existence of only two trophic levels and restricted to the wet season. Finally, it was very effective in the periphyton-based chain, which offers the highest rate of contamination of the source but, above all, the largest number of trophic levels.

Large-scale spatial and interspecies differences in trace elements and stable isotopes in marine wild fish from Chinese waters

Energy Technology Data Exchange (ETDEWEB)

Zhang, Wei [Key Laboratory of Marine Bio-resources Sustainable Utilization, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Wang, Wen-Xiong, E-mail: wwang@ust.hk [Division of Life Science, HKUST, Clear Water Bay, Kowloon (Hong Kong)

2012-05-15

Highlights: Black-Right-Pointing-Pointer A large-scale study on trace element levels in marine wild fish from Chinese waters. Black-Right-Pointing-Pointer Spatial variation found for Al, As, Cd, Cr, Fe, Ni, Pb, but not for Ag, Cu, Mo, Se and Zn. Black-Right-Pointing-Pointer The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb. Black-Right-Pointing-Pointer No biomagnification occurred for any of the trace elements studied in marine fish. Black-Right-Pointing-Pointer No obvious health risk from the intake of trace elements through fish consumption. - Abstract: We conducted a large scale investigation of twelve trace element levels and stable isotopes ({delta}{sup 13}C and {delta}{sup 15}N) in twenty-nine marine wild fish species collected from Chinese coastal waters. Trace element levels varied significantly with species. Clear spatial variations were found for Al, As, Cd, Cr, Fe, Ni, and Pb, whereas Ag, Cu, Mo, Se and Zn did not show much spatial variation. The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb, whereas the most southern waters (Haikou) contained the lowest concentrations of Al, Fe, and Pb. There was no correlation between log-transformed trace elements concentrations and {delta}{sup 15}N values or {delta}{sup 13}C values, indicating no biomagnification among these trace elements. The calculated hazard quotients (HQ) of 10 elements were less than 1, thus there was no obvious health risk from the intake of trace elements through marine wild fish consumption.

Aquatic to terrestrial transfer of sediment associated persistent organic pollutants is enhanced by bioamplification processes.

Science.gov (United States)

Daley, Jennifer M; Corkum, Lynda D; Drouillard, Ken G

2011-09-01

Ephemeral emergent insects, such as mayflies (Hexagenia spp.), are commonly used as biomonitors of persistent organic pollutants (POPs) and provide a vector for aquatic-terrestrial contaminant transfer. Mayflies bioaccumulate sediment-associated contaminants by bioconcentration and biomagnification during the aquatic stage and concentrate POP residues postemergence due to bioamplification, which occurs as a result of weight and lipid loss without contaminant loss. The present study quantified polychlorinated biphenyl (PCB) bioamplification in male and female emergent mayflies at three sites. Male mayflies used 36 to 68% of their lipids during emergence, with the exception of caged males that were prevented from flight. Females did not lose lipid content between pre-emergent nymph and emerged life stages. Mass balance indicated no PCB elimination between life stages. The mean PCB bioamplification factor, expressed as the ratio of lipid-equivalent PCB concentrations across life stages, was 2.05 ± 0.38 for male imagos/nymphs and 1.91 ± 0.18 for male imago/subimago life stages. For females, bioamplification factors were close to unity. Wildlife consumers of imago stages of emergent mayflies can potentially increase their total daily intake of PCBs by 36% depending on the sex-ratio composition of their diet relative to animals that feed predominantly on nymph or subimago stages during mass emergence events. Copyright © 2011 SETAC.

Fly ash dynamics in soil-water systems

International Nuclear Information System (INIS)

Sharma, S.; Fulekar, M.H.; Jayalakshmi, C.P.

1989-01-01

Studies regarding the effluents and coal ashes (or fly ash) resulting from coal burning are numerous, but their disposal and interactions with the soil and water systems and their detailed environmental impact assessment with concrete status reports on a global scale are scanty. Fly ash dynamics in soil and water systems are reviewed. After detailing the physical composition of fly ash, physicochemical changes in soil properties due to fly ash amendment are summarized. Areas covered include texture and bulk density, moisture retention, change in chemical equilibria, and effects of fly ash on soil microorganisms. Plant growth in amended soils is discussed, as well as plant uptake and accumulation of trace elements. In order to analyze the effect of fly ash on the physicochemical properties of water, several factors must be considered, including surface morphology of fly ash, pH of the ash sluice water, pH adjustments, leachability and solubility, and suspended ash and settling. The dynamics of fly ash in water systems is important due to pollution of groundwater resources from toxic components such as trace metals. Other factors summarized are bioaccumulation and biomagnification, human health effects of contaminants, and the impact of radionuclides in fly ash. Future research needs should focus on reduction of the environmental impact of fly ash and increasing utilization of fly ash as a soil amendment. 110 refs., 2 figs., 10 tabs

Patterns of transuranic uptake by aquatic organisms: consequences and implications

International Nuclear Information System (INIS)

Eyman, L.D.; Trabalka, J.R.

1980-01-01

Literature on the behavior of plutonium and transuranic elements in aquatic organisms is reviewed. The commonality of observed distribution coefficients over a wide array of aquatic environments (both freshwater and marine) and the lack of biomagnification in aquatic food chains from these environments are demonstrated. These findings lead to the conclusion that physical processes dominate in the transfer of transuranic elements from aquatic environments to man. The question of the nature of the association of plutonium with aquatic biota (surface sorption vs biological incorporation) is discussed as well as the importance of short food chains in the transfer of plutonium to man

Activation of 125I-Factor IX and 125I-Factor X: Effect of tissue factor and Factor VII, Factor Xsub(a) and thrombin

International Nuclear Information System (INIS)

Oesterud, B.; Rapaport, S.I.

Activation of Factor IX and Factor X was studied by adding 125 I-Factor IX or 125 I-Factor X to reaction mixtures and quantitating cleavage products by reduced sodium dodecylsulfate gel electrophoresis. Thrombin failed to activate Factors IX or X; Factor Xsub(a) produced insignificant amounts of cleavage products of both factors. In contrast, the reaction product of tissue factor and Factor VII cleaved large amounts of both Factor IX and Factor X in purified systems and in plasma. In incubation mixtures of plasma containing added 125 I-Factor IX or 125 I-Factor X, tissue factor and Ca 2+ ions, the percentage of total radioactivity in the heavy chain peak of 125 I-IXsub(a) and the heavy chain of 125 I-Xsub(a) increased at a similar rate. When the tissue factor was diluted, similar curves were obtained for percent cleavage of 125 I-Factor IX and percent cleavage of 125 I-Factor X plotted against tissue factor concentration. These findings support the hypothesis that activation of Factor IX by the tissue factor-Factor VII reaction product represents a physiologically significant step in normal haemostasis. (author)

Bioaccumulation of tritiated water in phytoplankton and trophic transfer of organically bound tritium to the blue mussel, Mytilus edulis

International Nuclear Information System (INIS)

Jaeschke, Benedict C.; Bradshaw, Clare

2013-01-01

Large releases of tritium are currently permitted in coastal areas due to assumptions that it rapidly disperses in the water and has a low toxicity due to its low energy emissions. This paper presents a laboratory experiment developed to identify previously untested scenarios where tritium may concentrate or transfer in biota relevant to Baltic coastal communities. Phytoplankton populations of Dunaliella tertiolecta and Nodularia spumigena were exposed at different growth-stages, to tritiated water (HTO; 10 MBq l −1 ). Tritiated D. tertiolecta was then fed to mussels, Mytilus edulis, regularly over a period of three weeks. Activity concentrations of phytoplankton and various tissues from the mussel were determined. Both phytoplankton species transformed HTO into organically-bound tritium (OBT) in their tissues. D. tertiolecta accumulated significantly more tritium when allowed to grow exponentially in HTO than if it had already reached the stationary growth phase; both treatments accumulated significantly more than the corresponding treatments of N. spumigena. No effect of growth phase on bioaccumulation of tritium was detectable in N. spumigena following exposure. After mussels were given 3 feeds of tritiated D. tertiolecta, significant levels of tritium were detected in the tissues. Incorporation into most mussel tissues appeared to follow a linear relationship with number of tritiated phytoplankton feeds with no equilibrium, highlighting the potential for biomagnification. Different rates of incorporation in species from a similar functional group highlight the difficulties in using a ‘representative’ species for modelling the transfer and impact of tritium. Accumulations of organic tritium into the mussel tissues from tritiated-phytoplankton demonstrate an environmentally relevant transfer pathway of tritium even when water-concentrations are reduced, adding weight to the assertion that organically bound tritium acts as a persistent organic pollutant. The

Persistent or not persistent? Polychlorinated biphenyls are readily depurated by grizzly bears (Ursus arctos horribilis).

Science.gov (United States)

Christensen, Jennie R; Letcher, Robert J; Ross, Peter S

2009-10-01

Major pharmacokinetic processes influencing polychlorinated biphenyl (PCB) accumulation in mammals include uptake, biotransformation, respiration, and excretion. We characterized some of the factors underlying PCB accumulation/loss by evaluating PCB concentrations and patterns in pre- and posthibernation grizzly bears (Ursus arctos horribilis) and their prey. The PCB congeners with vicinal meta- and para-chlorine unsubstituted hydrogen positions consistently showed loss both before and during hibernation, supporting the idea of a dominant role for biotransformation. Retention of all other studied congeners relative to that of PCB 194 varied widely (from bears do not eat or excrete. We estimate that grizzly bears retain less than 10% of total PCBs taken up from their diet. Our results suggest that for grizzly bears, depuration of PCBs via biotransformation is important (explaining approximately 40% of loss), but that nonbiotransformation processes, such as excretion, may be more important (explaining approximately 60% of loss). These findings, together with the approximately 91% loss of the persistent PCB 153 congener relative to PCB 194 in grizzly bears, raise important questions about how one defines persistence of PCBs in wildlife and may have bearing on the interpretation of food-web biomagnification studies.

Toxicity and uptake of cyclic nitramine explosives in ryegrass Lolium perenne

International Nuclear Information System (INIS)

Rocheleau, Sylvie; Lachance, Bernard; Kuperman, Roman G.; Hawari, Jalal; Thiboutot, Sonia; Ampleman, Guy; Sunahara, Geoffrey I.

2008-01-01

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) are cyclic nitramines used as explosives. Their ecotoxicities have been characterized incompletely and little is known about their accumulation potential in soil organisms. We assessed the toxicity and uptake of these explosives in perennial ryegrass Lolium perenne L. exposed in a Sassafras sandy loam (SSL) or in a sandy soil (DRDC, CL-20 only) containing contrasting clay contents (11% and 0.3%, respectively). A 21-d exposure to RDX, HMX or CL-20 in either soil had no adverse effects on ryegrass growth. RDX and HMX were translocated to ryegrass shoots, with bioconcentration factors (BCF) of up to 15 and 11, respectively. In contrast, CL-20 was taken up by the roots (BCF up to 19) with no translocation to the shoots. These studies showed that RDX, HMX, and CL-20 can accumulate in plants and may potentially pose a risk of biomagnification across the food chain. - Cyclic nitramine explosives accumulate in perennial ryegrass and exhibit distinct uptake patterns

Toxicity and uptake of cyclic nitramine explosives in ryegrass Lolium perenne

Energy Technology Data Exchange (ETDEWEB)

Rocheleau, Sylvie; Lachance, Bernard [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada); Kuperman, Roman G. [Edgewood Chemical Biological Center, 5183 Blackhawk Road, Aberdeen Proving Ground, MD 21010-5424 (United States); Hawari, Jalal [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada); Thiboutot, Sonia; Ampleman, Guy [Defense Research and Development Canada, 2459 Pie IX Boulevard, Val Belair, Quebec G3J 1X5 (Canada); Sunahara, Geoffrey I. [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada)], E-mail: geoffrey.sunahara@cnrc-nrc.gc.ca

2008-11-15

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) are cyclic nitramines used as explosives. Their ecotoxicities have been characterized incompletely and little is known about their accumulation potential in soil organisms. We assessed the toxicity and uptake of these explosives in perennial ryegrass Lolium perenne L. exposed in a Sassafras sandy loam (SSL) or in a sandy soil (DRDC, CL-20 only) containing contrasting clay contents (11% and 0.3%, respectively). A 21-d exposure to RDX, HMX or CL-20 in either soil had no adverse effects on ryegrass growth. RDX and HMX were translocated to ryegrass shoots, with bioconcentration factors (BCF) of up to 15 and 11, respectively. In contrast, CL-20 was taken up by the roots (BCF up to 19) with no translocation to the shoots. These studies showed that RDX, HMX, and CL-20 can accumulate in plants and may potentially pose a risk of biomagnification across the food chain. - Cyclic nitramine explosives accumulate in perennial ryegrass and exhibit distinct uptake patterns.

Predicting Outcomes of Hormone and Chemotherapy in the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC Study by Biochemically-inspired Machine Learning [version 3; referees: 2 approved

Directory of Open Access Journals (Sweden)

Eliseos J. Mucaki

2017-05-01

Full Text Available Genomic aberrations and gene expression-defined subtypes in the large METABRIC patient cohort have been used to stratify and predict survival. The present study used normalized gene expression signatures of paclitaxel drug response to predict outcome for different survival times in METABRIC patients receiving hormone (HT and, in some cases, chemotherapy (CT agents. This machine learning method, which distinguishes sensitivity vs. resistance in breast cancer cell lines and validates predictions in patients; was also used to derive gene signatures of other HT  (tamoxifen and CT agents (methotrexate, epirubicin, doxorubicin, and 5-fluorouracil used in METABRIC. Paclitaxel gene signatures exhibited the best performance, however the other agents also predicted survival with acceptable accuracies. A support vector machine (SVM model of paclitaxel response containing genes ABCB1, ABCB11, ABCC1, ABCC10, BAD, BBC3, BCL2, BCL2L1, BMF, CYP2C8, CYP3A4, MAP2, MAP4, MAPT, NR1I2, SLCO1B3, TUBB1, TUBB4A, and TUBB4B was 78.6% accurate in predicting survival of 84 patients treated with both HT and CT (median survival ≥ 4.4 yr. Accuracy was lower (73.4% in 304 untreated patients. The performance of other machine learning approaches was also evaluated at different survival thresholds. Minimum redundancy maximum relevance feature selection of a paclitaxel-based SVM classifier based on expression of genes BCL2L1, BBC3, FGF2, FN1, and TWIST1 was 81.1% accurate in 53 CT patients. In addition, a random forest (RF classifier using a gene signature (ABCB1, ABCB11, ABCC1, ABCC10, BAD, BBC3, BCL2, BCL2L1, BMF, CYP2C8, CYP3A4, MAP2, MAP4, MAPT, NR1I2,SLCO1B3, TUBB1, TUBB4A, and TUBB4B predicted >3-year survival with 85.5% accuracy in 420 HT patients. A similar RF gene signature showed 82.7% accuracy in 504 patients treated with CT and/or HT. These results suggest that tumor gene expression signatures refined by machine learning techniques can be useful for

Predicting Outcomes of Hormone and Chemotherapy in the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) Study by Biochemically-inspired Machine Learning.

Science.gov (United States)

Mucaki, Eliseos J; Baranova, Katherina; Pham, Huy Q; Rezaeian, Iman; Angelov, Dimo; Ngom, Alioune; Rueda, Luis; Rogan, Peter K

2016-01-01

Genomic aberrations and gene expression-defined subtypes in the large METABRIC patient cohort have been used to stratify and predict survival. The present study used normalized gene expression signatures of paclitaxel drug response to predict outcome for different survival times in METABRIC patients receiving hormone (HT) and, in some cases, chemotherapy (CT) agents. This machine learning method, which distinguishes sensitivity vs. resistance in breast cancer cell lines and validates predictions in patients; was also used to derive gene signatures of other HT  (tamoxifen) and CT agents (methotrexate, epirubicin, doxorubicin, and 5-fluorouracil) used in METABRIC. Paclitaxel gene signatures exhibited the best performance, however the other agents also predicted survival with acceptable accuracies. A support vector machine (SVM) model of paclitaxel response containing genes  ABCB1, ABCB11, ABCC1, ABCC10, BAD, BBC3, BCL2, BCL2L1, BMF, CYP2C8, CYP3A4, MAP2, MAP4, MAPT, NR1I2, SLCO1B3, TUBB1, TUBB4A, and TUBB4B  was 78.6% accurate in predicting survival of 84 patients treated with both HT and CT (median survival ≥ 4.4 yr). Accuracy was lower (73.4%) in 304 untreated patients. The performance of other machine learning approaches was also evaluated at different survival thresholds. Minimum redundancy maximum relevance feature selection of a paclitaxel-based SVM classifier based on expression of genes  BCL2L1, BBC3, FGF2, FN1,  and  TWIST1   was 81.1% accurate in 53 CT patients. In addition, a random forest (RF) classifier using a gene signature ( ABCB1, ABCB11, ABCC1, ABCC10, BAD, BBC3, BCL2, BCL2L1, BMF, CYP2C8, CYP3A4, MAP2, MAP4, MAPT, NR1I2,SLCO1B3, TUBB1, TUBB4A,  and TUBB4B ) predicted >3-year survival with 85.5% accuracy in 420 HT patients. A similar RF gene signature showed 82.7% accuracy in 504 patients treated with CT and/or HT. These results suggest that tumor gene expression signatures refined by machine learning techniques can be useful for

Bioaccumulation trends of arsenic and antimony in a freshwater ecosystem affected by mine drainage

Science.gov (United States)

Dovick, Meghan A.; Kulp, Thomas R.; Arkle, Robert .; Pilliod, David S.

2015-01-01

We compared As and Sb bioaccumulation and biomagnification when these metalloids co-occurred at varying environmental concentrations in a stream and wetlands near a contaminated mine site in Idaho (USA). We measured As and Sb concentrations in water and substrate samples, and in tissues of organisms representing several trophic levels. Bioaccumulation of both As and Sb was observed in stream organisms with the following trend of bio-diminution with increasing trophic level: primary producers > tadpoles > macroinvertebrates > trout. We also note reductions in metalloid concentrations in one of two stream remediation reaches engineered within the past 17 years to ameliorate metalloid contamination in the stream. Several wetlands contained thick microbial mats and were highly populated with boreal toad tadpoles that fed on them. The mats were extremely contaminated (up to 76 564 mg kg–1 As and 675 mg kg–1 Sb) with amorphous As- and Sb-bearing minerals that we interpret as biogenic precipitates from geomicrobiological As- and Sb-cycling. Ingested mat material provided a direct source of metalloids to tadpoles, and concentrations of 3867 mg kg–1 (As) and 375 mg kg–1 (Sb) reported here represent the highest whole body As and Sb levels ever reported in living tadpoles. The bulk of tadpole metalloid burden remained in the gut despite attempts to purge the tadpoles prior to analysis. This study adds to a number of recent investigations reporting bioaccumulation, but not biomagnification, of As and Sb in food webs. Moreover, our results suggest that tadpoles, in particular, may be more resistant to metalloid contamination than previously assumed.

Some aspects of linacs as applied to the ISL benchmark facility

International Nuclear Information System (INIS)

Shepard, K.W.

1992-01-01

This paper considers several aspects of using linacs in a radioactive beam facility in terms of the Isospin Laboratory (ISL) Benchmark Facility (BMF) plan, described in the 1991 white paper for a possible radioactive-beam laboratory. The intention is not to review comprehensively the application of linacs to an ISL facility, but to compare in outline form several linac options for such a facility. Particular emphasis is given to the use of superconducting rf technology for the secondary beam accelerator. In what follows, first a possible normally-conducting light-ion linac for a primary beam accelerator is briefly outlined. Then the performance and cost of two options for a secondary beam accelerator are compared: a recent design for a normal-conducting cw linac, and an ATLAS-type superconducting linac. Finally, some of the problems which may be encountered at the entrance of a secondary beam linac are discussed

Multivariable Analysis of Gluten-Free Pasta Elaborated with Non-Conventional Flours Based on the Phenolic Profile, Antioxidant Capacity and Color.

Science.gov (United States)

Camelo-Méndez, Gustavo A; Flores-Silva, Pamela C; Agama-Acevedo, Edith; Bello-Pérez, Luis A

2017-12-01

The phenolic compounds, color and antioxidant capacity of gluten-free pasta prepared with non-conventional flours such as chickpea (CHF), unripe plantain (UPF), white maize (WMF) and blue maize (BMF) were analyzed. Fifteen phenolic compounds (five anthocyanins, five hydroxybenzoic acids, three hydroxycinnamic acids, one hydroxyphenylacetic acid and one flavonol) were identified in pasta prepared with blue maize, and 10 compounds were identified for samples prepared with white maize. The principal component analysis (PCA) led to results describing 98% of the total variance establishing a clear separation for each pasta. Both the proportion (25, 50 and 75%) and type of maize flour (white and blue) affected the color parameters (L*, C ab *, h ab and ΔE* ab ) and antioxidant properties (DPPH, ABTS and FRAP methods) of samples, thus producing gluten-free products with potential health benefits intended for general consumers (including the population with celiac disease).

Simple metal model for predicting uptake and chemical processes in sewage-fed aquaculture ecosystem

DEFF Research Database (Denmark)

Azanu, David; Jorgensen, Sven Erik; Darko, Godfred

2016-01-01

but not working properly for chromium and mercury. Additional processes, including precipitation of chromium and bio-magnification of methylmercury were introduced to explain concentration of chromium and mercury in fish. Comparison of measured and predicted metal concentration used for validation gave a linear......% was the best, which is also in accordance to the fish growth. The ratio of fish food was also calibrated to be 70% due to a food chain in the water and 30% due to a food chain in the sediment. This gave the lowest uncertainty of the model. The simple metal model was working acceptably well for Pb, Cu and Cd...

Uptake of americium-241 by algae and bacteria

Energy Technology Data Exchange (ETDEWEB)

Giesy, Jr, J P; Paine, D [Savannah River Ecology Lab., Aiken, S.C. (USA)

1978-01-01

The uptake of americium by three algae, Scenedesmus obliguus, Selenastrum capricomutum and Chlorella pyrenosdosa and a bacterium Aeromonas hydrophila was studied. Live and fixed cells of each algal species and live bacterial cells were used. It is shown that algae and bacteria concentrate americium 241 to a high degree which makes them important links in the biomagnification phenomenon which may ultimately lead to a human hazard and be potentially important in recycling Am /sup 241/ in the water column and mobilization from sediments. Chemical fixation of algal cells caused increased uptake which indicated that uptake is by passive diffusion and probably due to chemical alteration of surface binding sites.

Comparative analyses of contaminant levels in bottom feeding and predatory fish using the National Contaminant Biomonitoring Program data

Energy Technology Data Exchange (ETDEWEB)

Kidwell, J.M. [Clement International Corp., Fairfax, VA (United States); Phillips, L.J. [Versar Inc., Springfield, VA (United States); Birchard, G.F. [George Mason Univ., Fairfax, VA (United States)

1995-06-01

Both bottom feeding and predatory fish accumulate chemical contaminants found in water. Bottom feeders are readily exposed to the greater quantities of chlorinated hydrocarbons and metals that accumulate in sediments. Predators, on the other hand, may bioaccumulate organochlorine pesticides, PCBs, and metals from the surrounding water or from feeding on other fish, including bottom feeders, which may result in the biomagnification of these compounds in their tissues. This study used National Contaminant Biomonitoring Program data produced by the Fish and Wildlife Service to test the hypothesis that differences exist between bottom feeders and predators in tissue levels of organochlorine pesticides, PCBs, and metals. 7 refs., 2 tabs.

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

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.

Exposure to second-hand smoke and the risk of tuberculosis in children and adults: a systematic review and meta-analysis of 18 observational studies.

Directory of Open Access Journals (Sweden)

Jayadeep Patra

2015-06-01

Full Text Available According to WHO Global Health Estimates, tuberculosis (TB is among the top ten causes of global mortality and ranks second after cardiovascular disease in most high-burden regions. In this systematic review and meta-analysis, we investigated the role of second-hand smoke (SHS exposure as a risk factor for TB among children and adults.We performed a systematic literature search of PubMed, Embase, Scopus, Web of Science, and Google Scholar up to August 31, 2014. Our a priori inclusion criteria encompassed only original studies where latent TB infection (LTBI and active TB disease were diagnosed microbiologically, clinically, histologically, or radiologically. Effect estimates were pooled using fixed- and random-effects models. We identified 18 eligible studies, with 30,757 children and 44,432 adult non-smokers, containing SHS exposure and TB outcome data for inclusion in the meta-analysis. Twelve studies assessed children and eight studies assessed adult non-smokers; two studies assessed both populations. Summary relative risk (RR of LTBI associated with SHS exposure in children was similar to the overall effect size, with high heterogeneity (pooled RR 1.64, 95% CI 1.00-2.83. Children showed a more than 3-fold increased risk of SHS-associated active TB (pooled RR 3.41, 95% CI 1.81-6.45, which was higher than the risk in adults exposed to SHS (summary RR 1.32, 95% CI 1.04-1.68. Positive and significant exposure-response relationships were observed among children under 5 y (RR 5.88, 95% CI 2.09-16.54, children exposed to SHS through any parent (RR 4.20, 95% CI 1.92-9.20, and children living under the most crowded household conditions (RR 5.53, 95% CI 2.36-12.98. Associations for LTBI and active TB disease remained significant after adjustment for age, biomass fuel (BMF use, and presence of a TB patient in the household, although the meta-analysis was limited to a subset of studies that adjusted for these variables. There was a loss of association

Food Adulteration and Bio-magnification of Environmental Contaminants: A Comprehensive Risk Framework for Bangladesh

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Nehreen eMajed

2016-05-01

Full Text Available This article thoroughly investigates the severity of the prevailing environmental conditions and evaluates the resulting threats to food intake and public health in Bangladesh by establishing relationship among different contaminant transfer mechanisms to human. It describes the potential of certain contaminants to get bio-magnified through the food chain. A database was prepared on a number of contaminants in the study area that are responsible for rendering different foods vulnerable to produce long term or short-term health effects. Contaminants that have been identified in the food sources were categorized in a continuum based on their allowable daily intake. A protocol has been developed which will enable the assessment of the potential of a contaminant to bio-magnify through food chain to understand the contribution of a contaminant on different levels of food chain. The study also provides a detailed assessment of the public health risks associated with direct ingestion of adulterated foods and intake of contaminants through food chain or water intake. Their intake to human body was quantified, which provides an indication of the toxicity level of the contaminants and possible impact on human health. The traditional four steps of risk assessment technique have been employed for some model contaminants (including metals, organic contaminants and food adulterants. Additionally, existing rules and regulations of Bangladesh were identified with possible limitations that can play significant role in controlling the food adulteration practices and concentration of contaminants in the environment and human body. Finally, a holistic approach to necessary interventions has been prescribed at policy, treatment and evaluation level to prevent the water pollution and food adulteration. Thus, a much-needed comprehensive framework is prescribed in this study to promote safety in food handling, preserve environment and improve health-based strategies in Bangladesh.

Methyl mercury concentrations in macroinvertebrates and fish from burned and undisturbed lakes on the Boreal Plain

Energy Technology Data Exchange (ETDEWEB)

Allen, E.W. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences; Prepas, E.E. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences; Lakehead Univ., Thunder Bay, ON (Canada). Faculty of Forest and the Forest Environment; Gabos, S.; Zhang, W. [Alberta Health and Wellness, Edmonton, AB (Canada); Strachan, W.M.J. [Environment Canada, Burlington, ON (Canada). National Water Research Inst.

2005-09-01

Methylmercury (MeHg) concentrations in macroinvertebrates and fish from 5 lakes in burned catchments in Alberta's Swan Hills region were compared with those from 5 reference lakes on the western Canadian Boreal Plain. The objective was to determine the effect of forest fire on the bioaccumulation of MeHg, a toxic pollutant. It was noted that lakes near the Alberta Special Waste Treatment Centre (ASWTC) have fish consumption advisories due to high mercury concentrations. In a separate comparison, MeHg concentrations in biota from a single lake were compared before and after a forest fire interrupted a prescribed timber harvest experiment. The affect of lake water chemistry, watershed characteristics, and trophic ecology on the bioaccumulation and biomagnification of MeHg in littoral food webs was also examined. The study area covered 2 ecoregions, the Boreal Foothills and the Boreal Mixedwood. Two years after the fire, MeHg concentrations in 5 of 6 aquatic taxa did not differ between burned and reference drainage basins in the Swan Hills. These results were in agreement with previous studies. Biomagnification of MeHg was negatively correlated with lake water chlorophyll 'a' concentration. Ecoregional variation in water chemistry seemed to influence MeHg concentrations in aquatic biota, which eluded comparisons of MeHg bioaccumulation between burned and reference drainage basins. MeHg concentrations in biota were negatively correlated with lake water pH, as well as with total phosphorous and dominant cation concentrations, all of which were higher in Mixedwood than in Foothills lakes. It was concluded that in the short-term, fire may lower MeHg concentrations in aquatic biota in a nutrient-rich setting by inducing an increase in lake productivity that dilutes MeHg at the base of the food web. 42 refs., 5 tabs., 7 figs.

Occurrence of Legacy and New Persistent Organic Pollutants in Avian Tissues from King George Island, Antarctica.

Science.gov (United States)

Kim, Jun-Tae; Son, Min-Hui; Kang, Jung-Ho; Kim, Jeong-Hoon; Jung, Jin-Woo; Chang, Yoon-Seok

2015-11-17

Legacy and new persistent organic pollutants (POPs), including polychlorinated naphthalenes (PCNs), Dechlorane Plus (DPs) and related compounds (Dechloranes), hexabromocyclododecanes (HBCDs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs), were analyzed in avian tissue samples from King George Island, Antarctica. The avian species consisted of the Gentoo penguin (Pygoscelis papua), the Adelie penguin (Pygoscelis adeliae), the South polar skua (Stercorarius maccormicki), and the Brown skua (Stercorarius antarcticus). HBCDs were detected in all samples and ranged from 1.67-713 pg/g-lipid. In the penguin samples, the concentrations of PCNs ranged from 0.69-2.07 ng/g-lipid, whereas those in the skua samples ranged from 7.41-175 ng/g-lipid. The levels of Dechloranes ranged from 0.60-1.30 ng/g-lipid in the penguin samples and from 6.57-47.4 ng/g-lipid in the skua samples. The concentrations and congener distributions of OCPs and PCBs were similar to the results of previous reports. The three new POPs were detected in all samples, and this study was one of the first reports on the occurrence of these pollutants in the Antarctic biota. Because Antarctica is one of the most pristine places on Earth, the detection of new POPs in the Antarctic birds, especially penguins, is direct evidence of the long-range transport of pollutants. Furthermore, the concentration ratios of the penguin to the skua samples (BMFs-p) were greater than 1 in most legacy and new POPs, and the BMFs-p values of the new POPs were comparable to those of some OCPs, suggesting a possibility of biomagnification. Despite the small sample size, the results of this study identified POP contamination of the Antarctic avian species and long-range transport and biomagnification of HBCDs, Dechloranes, and PCNs.

Defining fish community structure in Lake Winnipeg using stable isotopes (δ{sup 13}C, δ{sup 15}N, δ{sup 34}S): Implications for monitoring ecological responses and trophodynamics of mercury and other trace elements

Energy Technology Data Exchange (ETDEWEB)

Ofukany, Amy F.A. [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3 (Canada); Wassenaar, Leonard I. [Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5 (Canada); Bond, Alexander L., E-mail: alex.bond@rspb.org.uk [Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5 (Canada); Hobson, Keith A. [Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5 (Canada)

2014-11-01

The ecological integrity of freshwater lakes is influenced by atmospheric and riverine deposition of contaminants, shoreline development, eutrophication, and the introduction of non-native species. Changes to the trophic structure of Lake Winnipeg, Canada, and consequently, the concentrations of contaminants and trace elements measured in tissues of native fishes, are likely attributed to agricultural runoff from the 977,800 km{sup 2} watershed and the arrival of non-native zooplankters and fishes. We measured δ{sup 13}C, δ{sup 15}N, and δ{sup 34}S along with concentrations of 15 trace elements in 17 native fishes from the north and south basins of Lake Winnipeg in 2009 and 2010. After adjusting for differences in isotopic baseline values between the two basins, fishes in the south basin had consistently higher δ{sup 13}C and δ{sup 34}S, and lower δ{sup 15}N. We found little evidence of biomagnification of trace elements at the community level, but walleye (Sander vitreus) and freshwater drum (Aplodinotus grunniens) had higher mercury and selenium concentrations with increased trophic position, coincident with increased piscivory. There was evidence of growth dilution of cobalt, copper, manganese, molybdenum, thallium, and vanadium, and bioaccumulation of mercury, which could be explained by increases in algal (and consequently, lake and fish) productivity. We conclude that the north and south basins of Lake Winnipeg represent very different communities with different trophic structures and trace element concentrations. - Highlights: • Anthropogenic eutrophication and non-native species affect Lake Winnipeg’s ecosystem. • We measured stable isotopes and trace elements in 15 native fish species. • There was more evidence for growth dilution than biomagnification for most elements. • The trophic structures of the north and south basins were different. • These results will help determine the effects of recent arrival of zebra mussels.

Defining fish community structure in Lake Winnipeg using stable isotopes (δ13C, δ15N, δ34S): Implications for monitoring ecological responses and trophodynamics of mercury and other trace elements

International Nuclear Information System (INIS)

Ofukany, Amy F.A.; Wassenaar, Leonard I.; Bond, Alexander L.; Hobson, Keith A.

2014-01-01

The ecological integrity of freshwater lakes is influenced by atmospheric and riverine deposition of contaminants, shoreline development, eutrophication, and the introduction of non-native species. Changes to the trophic structure of Lake Winnipeg, Canada, and consequently, the concentrations of contaminants and trace elements measured in tissues of native fishes, are likely attributed to agricultural runoff from the 977,800 km 2 watershed and the arrival of non-native zooplankters and fishes. We measured δ 13 C, δ 15 N, and δ 34 S along with concentrations of 15 trace elements in 17 native fishes from the north and south basins of Lake Winnipeg in 2009 and 2010. After adjusting for differences in isotopic baseline values between the two basins, fishes in the south basin had consistently higher δ 13 C and δ 34 S, and lower δ 15 N. We found little evidence of biomagnification of trace elements at the community level, but walleye (Sander vitreus) and freshwater drum (Aplodinotus grunniens) had higher mercury and selenium concentrations with increased trophic position, coincident with increased piscivory. There was evidence of growth dilution of cobalt, copper, manganese, molybdenum, thallium, and vanadium, and bioaccumulation of mercury, which could be explained by increases in algal (and consequently, lake and fish) productivity. We conclude that the north and south basins of Lake Winnipeg represent very different communities with different trophic structures and trace element concentrations. - Highlights: • Anthropogenic eutrophication and non-native species affect Lake Winnipeg’s ecosystem. • We measured stable isotopes and trace elements in 15 native fish species. • There was more evidence for growth dilution than biomagnification for most elements. • The trophic structures of the north and south basins were different. • These results will help determine the effects of recent arrival of zebra mussels

Modulators of mercury risk to wildlife and humans in the context of rapid global change

Science.gov (United States)

Eagles-Smith, Collin A.; Silbergeld, Ellen K.; Basu, Niladri; Bustamante, Paco; Diaz-Barriga, Fernando; Hopkins, William A.; Kidd, Karen A.; Nyland, Jennifer F.

2018-01-01

Environmental mercury (Hg) contamination is an urgent global health threat. The complexity of Hg in the environment can hinder accurate determination of ecological and human health risks, particularly within the context of the rapid global changes that are altering many ecological processes, socioeconomic patterns, and other factors like infectious disease incidence, which can affect Hg exposures and health outcomes. However, the success of global Hg-reduction efforts depends on accurate assessments of their effectiveness in reducing health risks. In this paper, we examine the role that key extrinsic and intrinsic drivers play on several aspects of Hg risk to humans and organisms in the environment. We do so within three key domains of ecological and human health risk. First, we examine how extrinsic global change drivers influence pathways of Hg bioaccumulation and biomagnification through food webs. Next, we describe how extrinsic socioeconomic drivers at a global scale, and intrinsic individual-level drivers, influence human Hg exposure. Finally, we address how the adverse health effects of Hg in humans and wildlife are modulated by a range of extrinsic and intrinsic drivers within the context of rapid global change. Incorporating components of these three domains into research and monitoring will facilitate a more holistic understanding of how ecological and societal drivers interact to influence Hg health risks.

Species-specific accumulation of dioxin related compounds in cetaceans collected from Japanese coastal waters

Energy Technology Data Exchange (ETDEWEB)

Kajiwara, N.; Watanabe, M.; Tanabe, S. [Center for Marine Environmental Studies (CMES), Ehime Univ. (Japan); Amano, M. [Ocean Research Inst., Univ. of Tokyo, Iwate (Japan); Yamada, T. [National Science Museum, Tokyo (Japan)

2004-09-15

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are extremely hazardous and persistent chemicals identified as contaminants in chlorophenols, herbicides, fly ash and other incineration products. Dioxin-like PCBs including non- and mono-ortho coplanar PCBs are referred to as dioxin related compounds and are evaluated on par with PCDD/Fs in environmental risks since they have a high toxicity, similar to that of PCDD/Fs. These congeners have a range of physicochemical characteristics, which profoundly affect their persistence, environmental distribution, and bioaccumulation in aquatic food chains. Fish-eating wildlife such as marine mammals are particularly vulnerable to such contamination given their long lives, high trophic level, relative inability to metabolize many persistent organic pollutants (POPs), and the biomagnification of these contaminants in aquatic food chains. However, most studies dealing with PCDDs and PCDFs in marine mammals have been carried out on pinnipeds, and data on PCDD/Fs levels in cetaceans are scarce. The present study is aimed at understanding the recent pattern of contamination by dioxin related compounds including non- and mono-ortho coplanar PCBs and PCDD/Fs in three cetacean species collected from Japanese coastal waters during 1998-2001, and also to discuss the factors determining the accumulation.

Using organic matter gradients to predict mercury cycling following environmental changes

Science.gov (United States)

Bjorn, E.; Bravo, A. G.; Jonsson, S.; Seelen, E.; Skrobonja, A.; Skyllberg, U.; Soerensen, A.; Zhu, W.

2017-12-01

The biogeochemical cycling of mercury (Hg) includes redox and methylation transformation reactions, largely mediated by microorganisms. These reactions are decisive for mobility and bioavailability of Hg in ecosystems. Organic matter (OM) plays several critical roles in these important transformation reactions. In many aquatic systems, the composition of OM is naturally diverse and dynamic, and subject to further alternations due to ecosystem changes induced by climate, eutrophication, land use, and industrial activities. We will present recent findings on how changing characteristics of OM along natural salinity and carbon gradients control Hg methylation and reduction reactions, as well as bioaccumulation processes. We will further discuss potential changes to Hg cycling, primarily in coastal seas, following ecosystem perturbations which alter the amount and characteristics of OM. The presentation will focus on recent research advancements describing how: (i) the binding of Hg to thiol functional groups in OM controls the chemical speciation of Hg, and thereby its availability for chemical reactions and uptake in biota, (ii) the composition of OM is a primary controlling factor for methylation and reduction rates of divalent Hg by electron donation and shuttling processes, (iii) the amount and characteristics of dissolved OM affect the structure and productivity of the pelagic food web, and thereby the biomagnification of methylmercury.

Ecological risk assessment of protected species at a military installation

International Nuclear Information System (INIS)

Jones, M.L.; Faulk, S.T.; Lukin, C.; Kochel, M.J.

1995-01-01

A quantitative ecological risk assessment was performed to determine adverse effects posed by potential chemical contamination for two state-protected mammal species (Skull Valley pocket gopher and spotted bat) known to occur or potentially occur within the confines of the US Army Dugway Proving Ground, Utah. Surface soil and prey items were analyzed for metals and total petroleum hydrocarbons. Concentrations of the target analytes in forage were estimated. Receptor-specific biological parameters and the use of a geographic information system allowed the risk assessment to be tailored to the very different natural histories of the two mammals. A grid of interpolated soil concentrations was created for the entire base using measured soil concentrations and knowledge of site history. Spatially-averaged soil exposure concentrations were calculated using receptor home range areas. Doses were stochastically computed using the probability density functions of soil exposure concentration data, biomagnification factors, and measured prey concentration data. An extensive literature search provided the ecotoxicological benchmark values for the contaminants and hazard quotients were computed. The use of receptor-specific information and a geographic information system for spatial analysis of contaminant concentrations and animal exposure allowed a more precise estimate of risk for these two state-protected mammal species

Factor XII (Hageman factor) deficiency

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/000545.htm Factor XII (Hageman factor) deficiency To use the sharing features on this ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

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.

Assessing mercury exposure and effects to American dippers in headwater streams near mining sites.

Science.gov (United States)

Henny, Charles J; Kaiser, James L; Packard, Heidi A; Grove, Robert A; Taft, Michael R

2005-10-01

To evaluate mercury (Hg) exposure and possible adverse effects of Hg on American dipper (Cinclus mexicanus) reproduction, we collected eggs and nestling feathers and the larval/nymph form of three Orders of aquatic macroinvertebrates (Ephemeroptera, Plecoptera and Trichoptera = EPT) important in their diet from three major headwater tributaries of the upper Willamette River, Oregon in 2002. The Coast Fork Willamette River is contaminated with Hg due to historical cinnabar (HgS) mining at the Black Butte Mine; the Row River is affected by past gold-mining operations located within the Bohemia Mining District, where Hg was used in the amalgamation process to recover gold; and the Middle Fork Willamette River is the reference area with no known mining. Methyl mercury (MeHg) concentrations (geometric mean) in composite EPT larvae (111.9 ng/g dry weight [dw] or 19.8 ng/g wet weight [ww]), dipper eggs (38.5 ng/g ww) and nestling feathers (1158 ng/g ww) collected from the Coast Fork Willamette were significantly higher than MeHg concentrations in EPT and dipper samples from other streams. Total mercury (THg) concentrations in surface sediments along the same Hg-impacted streams were investigated by others in 1999 (Row River tributaries) and 2002 (Coast Fork). The reported sediment THg concentrations paralleled our biological findings. Dipper breeding territories at higher elevations had fewer second clutches; however, dipper reproductive success along all streams (including the lower elevation and most Hg-contaminated Coast Fork), was judged excellent compared to other studies reviewed. Furthermore, MeHg concentrations in EPT samples from this study were well below dietary concentrations in other aquatic bird species, such as loons and ducks, reported to cause Hg-related reproductive problems. Our data suggest that either dipper feathers or EPT composites used to project MeHg concentrations in dipper feathers (with biomagnification factor of 10-20x) may be used, but with

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

Factorization and non-factorization in diffractive hard scattering

International Nuclear Information System (INIS)

Berera, Arjun

1997-01-01

Factorization, in the sense defined for inclusive hard scattering, is discussed for diffractive hard scattering. A factorization theorem similar to its inclusive counterpart is presented for diffractive DIS. For hadron-hadron diffractive hard scattering, in contrast to its inclusive counterpart, the expected breakdown of factorization is discussed. Cross section estimates are given from a simple field theory model for non-factorizing double-pomeron-exchange (DPE) dijet production with and without account for Sudakov suppression

Crystal Structure of Human Factor VIII: Implications for the Formation of the Factor IXa-Factor VIIIa Complex

Energy Technology Data Exchange (ETDEWEB)

Ngo, J.C.; Huang, M.; Roth, D.A.; Furie, B.C.; Furie, B. (Wyeth); (MBL)

2008-06-03

Factor VIII is a procofactor that plays a critical role in blood coagulation, and is missing or defective in hemophilia A. We determined the X-ray crystal structure of B domain-deleted human factor VIII. This protein is composed of five globular domains and contains one Ca{sup 2+} and two Cu{sup 2+} ions. The three homologous A domains form a triangular heterotrimer where the A1 and A3 domains serve as the base and interact with the C2 and C1 domains, respectively. The structurally homologous C1 and C2 domains reveal membrane binding features. Based on biochemical studies, a model of the factor IXa-factor VIIIa complex was constructed by in silico docking. Factor IXa wraps across the side of factor VIII, and an extended interface spans the factor VIII heavy and light chains. This model provides insight into the activation of factor VIII and the interaction of factor VIIIa with factor IXa on the membrane surface.

Crystal Structure of Human Factor VIII: Implications for the Formation of the Factor IXa-Factor VIIIa Complex

Energy Technology Data Exchange (ETDEWEB)

Chi Ki Ngo,J.; Huang, M.; Roth, D.; Furie, B.; Furie, B.

2008-01-01

Factor VIII is a procofactor that plays a critical role in blood coagulation, and is missing or defective in hemophilia A. We determined the X-ray crystal structure of B domain-deleted human factor VIII. This protein is composed of five globular domains and contains one Ca(2+) and two Cu(2+) ions. The three homologous A domains form a triangular heterotrimer where the A1 and A3 domains serve as the base and interact with the C2 and C1 domains, respectively. The structurally homologous C1 and C2 domains reveal membrane binding features. Based on biochemical studies, a model of the factor IXa-factor VIIIa complex was constructed by in silico docking. Factor IXa wraps across the side of factor VIII, and an extended interface spans the factor VIII heavy and light chains. This model provides insight into the activation of factor VIII and the interaction of factor VIIIa with factor IXa on the membrane surface.

Activation of factor VII bound to tissue factor: A key early step in the tissue factor pathway of blood coagulation

International Nuclear Information System (INIS)

Rao, L.V.M.; Rapaport, S.I.

1988-01-01

Whether the factor VII/tissue factor complex that forms in tissue factor-dependent blood coagulation must be activated to factor VIIa/tissue factor before it can activate its substrates, factor X and IX, has been a difficult question to answer because the substrates, once activated, back-activate factor VII. The earlier studies suggested that human factor VII/tissue factor cannot activate factor IX. Studies have now been extended to the activation of factor X. Reaction mixtures were made with purified factor VII, X, and tissue factor; in some experiments antithrombin III and heparin were added to prevent back-activation of factor VII. Factor X was activated at similar rates in reaction mixtures containing either VII or factor VIIa after an initial 30-sec lag with factor VII. In reaction mixtures with factor VII a linear activation of factor X was established several minutes before cleavage of 125 I-labeled factor VII to the two-chain activated molecule was demonstrable on gel profiles. These data suggest that factor VII/tissue factor cannot activate measurable amounts of factor X over several minutes. Overall, the results support the hypothesis that a rapid preferential activation of factor VII bound to tissue factor by trace amounts of factor Xa is a key early step in tissue factor-dependent blood coagulation

Bioaccumulation of organochlorine pollutants in the fish community in Lake Arungen, Norway

International Nuclear Information System (INIS)

Sharma, Chhatra Mani; Rosseland, Bjorn Olav; Almvik, Marit; Eklo, Ole Martin

2009-01-01

Organochlorine pollutants in the major fish species (pike Esox lucius, perch Perca fluviatilis, and roach Rutilus rutilus) of Lake Arungen, Norway, were investigated after an extensive removal of large pike in 2004. The organochlorine pollutants detected in fish liver samples in 2005 were dichlorodiphenyltrichloroethane (DDTs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and heptachlor epoxide (HCE). DDTs were the dominant among all analyzed OCs. ΣPCB and HCB, detected in fish from two clearly distinct trophic levels (prey and predators), give an indication of biomagnification. All OC concentrations in female pike were significantly lower compared to males, which might be due to the removal of high concentrations of pollutants in roe during spawning. - Organochlorine pollutants in fish tissues tend to magnify up the food chain

Metals, Metalloids and Radionuclides in the Baltic Sea Ecosystem

International Nuclear Information System (INIS)

Szefer, P.

2002-01-01

The state of knowledge of the distribution, bioavailability, biomagnification, discrimination, fate and sources of chemical pollutants (metals, metalloids, radionuclides and nutrients) in all compartments (atmosphere, water, deposits, biota) of the Baltic environment is presented. Particular components of the Baltic ecosystem are considered as potential monitors of pollutants. Budgets of chemical elements and the ecological status of the Baltic Sea in the past, present and future are presented. Estimates of health risks to man in respect to some toxic metals and radionuclides in fish and seafood are briefly discussed. The content of the book makes possible the identification of gaps in our environmental knowledge of the Baltic Sea, with certain sections establishing possible priorities, key areas or strategies for future research

Activation of factor VII bound to tissue factor: a key early step in the tissue factor pathway of blood coagulation.

OpenAIRE

Rao, L V; Rapaport, S I

1988-01-01

Whether the factor VII/tissue factor complex that forms in tissue factor-dependent blood coagulation must be activated to factor VIIa/tissue factor before it can activate its substrates, factor X and factor IX, has been a difficult question to answer because the substrates, once activated, back-activate factor VII. Our earlier studies suggested that human factor VII/tissue factor cannot activate factor IX. Studies have now been extended to the activation of factor X. Reaction mixtures were ma...

Risk Factors

Science.gov (United States)

... cells do not invade nearby tissues or spread. Risk Factors Key Points Factors That are Known to ... chemicals . Factors That are Known to Increase the Risk of Cancer Cigarette Smoking and Tobacco Use Tobacco ...

Determining the Number of Factors in P-Technique Factor Analysis

Science.gov (United States)

Lo, Lawrence L.; Molenaar, Peter C. M.; Rovine, Michael

2017-01-01

Determining the number of factors is a critical first step in exploratory factor analysis. Although various criteria and methods for determining the number of factors have been evaluated in the usual between-subjects R-technique factor analysis, there is still question of how these methods perform in within-subjects P-technique factor analysis. A…

Carbon and nitrogen stable isotopes and metal concentration in food webs from a mining-impacted coastal lagoon

International Nuclear Information System (INIS)

Marin-Guirao, Lazaro; Lloret, Javier; Marin, Arnaldo

2008-01-01

Two food webs from the Mar Menor coastal lagoon, differing in the distance from the desert-stream through which mining wastes were discharged, were examined by reference to essential (Zn and Cu) and non-essential (Pb and Cd) metal concentrations and stable isotopes content (C and N). The partial extraction technique applied, which reflects the availability of metals to organisms after sediment ingestion, showed higher bioavailable metal concentrations in sediments from the station influenced by the mining discharges, in agreement with the higher metal concentrations observed in organisms, which in many cases exceeded the regulatory limits established in Spanish legislation concerning seafood. Spatial differences in essential metal concentrations in the fauna suggest that several organisms are exposed to metal levels above their regulation capacity. Differences in isotopic composition were found between both food webs, the wadi-influenced station showing higher δ 15 N values and lower δ 13 C levels, due to the discharge of urban waste waters and by the entrance of freshwater and allochthonous marsh plants. The linear-regressions between trophic levels (as indicated by δ 15 N) and the metal content indicated that biomagnification does not occur. In the case of invertebrates, since the 'handle strategy' of the species and the physiological requirements of the organisms, among other factors, determine the final concentration of a specific element, no clear relationships between trophic level and the metal content are to be expected. For their part, fish communities did not show clear patterns in the case of any of the analyzed metals, probably because most fish species have similar metal requirements, and because biological factors also intervened. Finally, since the study deals with metals, assumptions concerning trophic transfer factors calculation may not be suitable since the metal burden originates not only from the prey but also from adsorption over the body

Carbon and nitrogen stable isotopes and metal concentration in food webs from a mining-impacted coastal lagoon

Energy Technology Data Exchange (ETDEWEB)

Marin-Guirao, Lazaro [Departamento de Ecologia e Hidrologia, Facultad de Biologia, Universidad de Murcia, 30100-Murcia (Spain)], E-mail: lamarin@um.es; Lloret, Javier; Marin, Arnaldo [Departamento de Ecologia e Hidrologia, Facultad de Biologia, Universidad de Murcia, 30100-Murcia (Spain)

2008-04-01

Two food webs from the Mar Menor coastal lagoon, differing in the distance from the desert-stream through which mining wastes were discharged, were examined by reference to essential (Zn and Cu) and non-essential (Pb and Cd) metal concentrations and stable isotopes content (C and N). The partial extraction technique applied, which reflects the availability of metals to organisms after sediment ingestion, showed higher bioavailable metal concentrations in sediments from the station influenced by the mining discharges, in agreement with the higher metal concentrations observed in organisms, which in many cases exceeded the regulatory limits established in Spanish legislation concerning seafood. Spatial differences in essential metal concentrations in the fauna suggest that several organisms are exposed to metal levels above their regulation capacity. Differences in isotopic composition were found between both food webs, the wadi-influenced station showing higher {delta}{sup 15}N values and lower {delta}{sup 13}C levels, due to the discharge of urban waste waters and by the entrance of freshwater and allochthonous marsh plants. The linear-regressions between trophic levels (as indicated by {delta}{sup 15}N) and the metal content indicated that biomagnification does not occur. In the case of invertebrates, since the 'handle strategy' of the species and the physiological requirements of the organisms, among other factors, determine the final concentration of a specific element, no clear relationships between trophic level and the metal content are to be expected. For their part, fish communities did not show clear patterns in the case of any of the analyzed metals, probably because most fish species have similar metal requirements, and because biological factors also intervened. Finally, since the study deals with metals, assumptions concerning trophic transfer factors calculation may not be suitable since the metal burden originates not only from the prey but

Heparanase enhances the generation of activated factor X in the presence of tissue factor and activated factor VII.

Science.gov (United States)

Nadir, Yona; Brenner, Benjamin; Fux, Liat; Shafat, Itay; Attias, Judith; Vlodavsky, Israel

2010-11-01

Heparanase is an endo-β-D-glucuronidase dominantly involved in tumor metastasis and angiogenesis. Recently, we demonstrated that heparanase is involved in the regulation of the hemostatic system. Our hypothesis was that heparanase is directly involved in activation of the coagulation cascade. Activated factor X and thrombin were studied using chromogenic assays, immunoblotting and thromboelastography. Heparanase levels were measured by enzyme-linked immunosorbent assay. A potential direct interaction between tissue factor and heparanase was studied by co-immunoprecipitation and far-western assays. Interestingly, addition of heparanase to tissue factor and activated factor VII resulted in a 3- to 4-fold increase in activation of the coagulation cascade as shown by increased activated factor X and thrombin production. Culture medium of human embryonic kidney 293 cells over-expressing heparanase and its derivatives increased activated factor X levels in a non-enzymatic manner. When heparanase was added to pooled normal plasma, a 7- to 8-fold increase in activated factor X level was observed. Subsequently, we searched for clinical data supporting this newly identified role of heparanase. Plasma samples from 35 patients with acute leukemia at presentation and 20 healthy donors were studied for heparanase and activated factor X levels. A strong positive correlation was found between plasma heparanase and activated factor X levels (r=0.735, P=0.001). Unfractionated heparin and an inhibitor of activated factor X abolished the effect of heparanase, while tissue factor pathway inhibitor and tissue factor pathway inhibitor-2 only attenuated the procoagulant effect. Using co-immunoprecipitation and far-western analyses it was shown that heparanase interacts directly with tissue factor. Overall, our results support the notion that heparanase is a potential modulator of blood hemostasis, and suggest a novel mechanism by which heparanase increases the generation of activated

The Battlefield Environment Division Modeling Framework (BMF). Part 1: Optimizing the Atmospheric Boundary Layer Environment Model for Cluster Computing

Science.gov (United States)

2014-02-01

idle waiting for the wavefront to reach it. To overcome this, Reeve et al. (2001) 3 developed a scheme in analogy to the red-black Gauss - Seidel iterative ...understandable procedure calls. Parallelization of the SIMPLE iterative scheme with SIP used a red-black scheme similar to the red-black Gauss - Seidel ...scheme, the SIMPLE method, for pressure-velocity coupling. The result is a slowing convergence of the outer iterations . The red-black scheme excites a 2

Transforming growth factor alpha, Shope fibroma growth factor, and vaccinia growth factor can replace myxoma growth factor in the induction of myxomatosis in rabbits.

Science.gov (United States)

Opgenorth, A; Nation, N; Graham, K; McFadden, G

1993-02-01

The epidermal growth factor (EGF) homologues encoded by vaccinia virus, myxoma virus, and malignant rabbit fibroma virus have been shown to contribute to the pathogenicity of virus infection upon inoculation of susceptible hosts. However, since the primary structures of these growth factors and the disease profiles induced by different poxvirus genera vary substantially, the degree to which the various EGF homologues perform similar roles in viral pathogenesis remains unclear. In order to determine whether different EGF-like growth factors can perform qualitatively similar functions in the induction of myxomatosis in rabbits, we created recombinant myxoma virus variants in which the native growth factor, myxoma growth factor (MGF), was disrupted and replaced with either vaccinia virus growth factor, Shope fibroma growth factor, or rat transforming growth factor alpha. Unlike the control virus containing an inactivated MGF gene, which caused marked attenuation of the disease syndrome and substantially less proliferation of the epithelial cell layers in the conjunctiva and respiratory tract, the recombinant myxoma virus strains expressing heterologous growth factors produced infections which were both clinically and histopathologically indistinguishable from wild-type myxomatosis. We conclude that these poxviral and cellular EGF-like growth factors, which are diverse with respect to primary structure and origin, have similar biological functions in the context of myxoma virus pathogenesis and are mitogenic for the same target cells.

Factor concentrates for the treatment of factor XIII deficiency.

Science.gov (United States)

Gootenberg, J E

1998-11-01

Factor XIII deficiency is a severe autosomal recessive bleeding disorder associated with a characteristic pattern of neonatal hemorrhage and a lifelong bleeding diathesis. Even relatively minor trauma can be followed by prolonged and recurrent bleeding. Intracranial hemorrhage is a frequent complication. With the development of safe and effective factor XIII concentrates, reliable prophylactic treatment is possible. Two plasma-derived, virus-inactivated factor XIII concentrates are currently in production. The first, Fibrogammin P, (Centeon LLC, King of Prussia, PA, USA; and Centeon Pharma GmbH, Marburg, Germany) is marketed in Europe, South America, South Africa, and Japan. It is distributed in the United States under a Food and Drug Administration Investigational New Drug Application. A second factor XIII concentrate (Bio Products Laboratory, Elstree, UK) is available for use only on a "named patient" compassionate basis in the United Kingdom. Patients with factor XIII deficiency who receive appropriately timed periodic infusions of such factor XIII concentrates are able to live normal lives, free from catastrophic bleeding episodes.

Epidermal growth factor and insulin-like growth factor I upregulate the expression of the epidermal growth factor system in rat liver

DEFF Research Database (Denmark)

Bor, M V; Sørensen, B S; Vinter-Jensen, L

2000-01-01

BACKGROUND/AIM: Both epidermal growth factor and insulin-like growth factor I play a role in connection with the liver. In the present study, the possible interaction of these two growth factor systems was studied by investigating the effect of epidermal growth factor or insulin-like growth factor...... I treatment on the expression of the epidermal growth factor receptor, and its activating ligands, transforming growth factor-alpha and epidermal growth factor. METHODS: Fifty-five male rats received no treatment, human recombinant epidermal growth factor or human recombinant insulin-like growth.......8+/-1.6 fmol/mg protein epidermal growth factor and 144+/-22 fmol/mg protein transforming growth factor-alpha. Both epidermal growth factor and insulin-like growth factor I treatment increased the expression of mRNA for transforming growth factor-alpha and epidermal growth factor receptor, as well...

Use of crops and livestock futures contracts in portfolios: an analysis of feasibility

Directory of Open Access Journals (Sweden)

Mattos Fabio L.

2003-01-01

Full Text Available According to Portfolio Theory, by combining assets that show a correlation inferior to one (1 among their individual returns, it becomes possible to create portfolios that reduce risk without damaging expected return. Crop and livestock futures contracts and company stocks show such a characteristic, which signals potential benefits when forming portfolios combining these two types of assets. This investment strategy is not often utilized in Brazil. The purpose of our research was to assess whether such an asset combination is actually advantageous to those creating investment portfolios in the Brazilian market. Our evaluation used instruments of analysis developed by Markowitz in Portfolio Theory and data about the return from crop and livestock futures contracts and stocks. The data was gathered from the Brazilian Futures and Commodities Exchange (BM&F and Brazil?s National Association of Open Market Institutions (ANDIMA between July 1994 and December 1998. The results of this work showed that the combination of these two types of assets in investment portfolios can be an interesting portfolio management alternative.

Value Relevance of Investment Properties: Evidence from the Brazilian Capital Market

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Ketlyn Alves Gonçalves

2017-04-01

Full Text Available This study investigates the relevance to the capital market of the assets recognized as investment properties of companies listed on the BM&F BOVESPA, in the period from 2011 to 2014. The research conducted was based on the Ohlson model (1995 and panel analysis was carried out using linear regression with POLS and Fixed and Random Effects estimators. Two hypothesis were made: (i that Earning and Equity generate accounting information relevant to investors; and (2 that Earning, Equity and Investment Property generate accounting information relevant to investors, assuming that investment properties have incremental effect on the relevance of this information relative only to earning and to equity. Both hypotheses were rejected, so it is concluded that Investment Property assets are not of value relevance in the determination of share price and do not influence the decision making of users of accounting information. The study adds to the limited literature on the value relevance of Investment Property, permitting a better understanding of the impact of accounting disclosures used by companies on their market value.

PENFIGOIDE DE MEMBRANAS MUCOSAS: A PROPÓSITO DE DOS CASOS CLÍNICOS

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Beatriz E Casnati Guberna

Full Text Available El penfigoide de membranas mucosas representa un heterogéneo grupo de enfermedades ampollares, autoinmunes y crónicas, que afecta las mucosas y /o la piel. Es una patología que origina como secuelas, cicatrices que motivan importantes incapacidades funcionales en las mucosas involucradas, provocando ceguera, dificultades en la masticación, la deglución o en la respiración. Su diagnóstico, tratamiento y control deben ser realizados por un equipo multidisciplinario. Se presentan dos casos clínicos de penfigoide de membranas mucosas de localización oral, por considerarlos de interés, dadas sus manifestaciones clínicas y la diferente evolución en cada uno de ellos. Se describen los métodos de diagnóstico y tratamientos durante 4 años de seguimiento y control, realizados en la Cátedra de Semiología y Patología BMF, Clínica de Estomatología de la Facultad de Odontología. Universidad de la República

Performance of farmers in the future stock market in agricultural sector

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Paulo Ricardo Lima

2013-03-01

Full Text Available This study aimed to evaluate the performance of the Coopermibra associated members related to agricultural contracts future. The study was carried in the municipality of Campo Mourão, State of Paraná, Brazil, through a descriptive and qualitative method. The sample consisted of 40 cooperative members, who were interviewed in September/2008 during on-farm visits together technical assistants or during farmers´ visits to the Cooperative. It was observed that 80% of the farmers perform early sales in the Cooperative branch. Among them, who can achieve a higher level of good decision (67.5%, are those that follow daily prices. The Cooperative works as an intermediary between the farmers and BM&F BOVESPA stock market because it has offered contracts to farmers for setting the price at the future at it branch, but it does not provide for the cooperative members a way to act directly in the market for derivatives. Such situation does not prevent the farmers to hold both types of contracts.

Changes in the financial ratios of the wholesale and retail sector companies arising from the new accounting of the operating lease

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Mariana Moreira Arrozio

2016-11-01

Full Text Available In a recent study, released by the International Accounting Standard Board (IASB, changes in lease accounting criteria will add $ 2 trillion to the balance sheets of US companies. This impact is mainly due to the accounting characteristics that the operating lease has, off balance item. In this sense, this research analyzed the operating leasing operations of the wholesale and retail companies, qualified as lessees, and the impacts of the publication of IFRS 16 as its determinant. The study was based on the extraction of the accounting information published in the financial statements of the companies listed on the Brazilian BMF & Bovespa stock exchange. The statistical technique used in the study was the Wilcoxon signed rank test. The obtained results with use of the Liquidity, Debt and Leverage ratios, calculated on the basis of the financial statements published in 2015 and the adjusted statements according to the disclosure, have a significant impact on the equity structure of these companies. They revealed an increase of debt level, financial leverage and in liquidity, observed by the recognition of new assets and liabilities.

Hemophilia B with mutations at glycine-48 of factor IX exhibited delayed activation by the factor VIIa-tissue factor complex.

Science.gov (United States)

Wu, P C; Hamaguchi, N; Yu, Y S; Shen, M C; Lin, S W

2000-10-01

Gly-48 is in the conserved DGDQC sequence (residues 47-51 of human factor IX) of the first EGF (EGF-1)-like domain of factor IX. The importance of the Gly-48 is manifested by two hemophilia B patients; factor IXTainan and factor IXMalmo27, with Gly-48 replaced by arginine (designated IXG48R) and valine (IXG48V), respectively. Both patients were CRM+ exhibiting mild hemophilic episodes with 25% (former) and 19% (latter) normal clotting activities. We characterize both factor IX variants to show the roles of Gly-48 and the conservation of the DGDQC sequence in factor IX. Purified plasma and recombinant factor IX variants exhibited approximately 26%-27% normal factor IX's clotting activities with G48R or G48V mutation. Both variants depicted normal quenching of the intrinsic fluorescence by increasing concentrations of calcium ions and Tb3+, indicating that arginine and valine substitution for Gly-48 did not perturb the calcium site in the EGF-1 domain. Activation of both mutants by factor XIa appeared normal. The reduced clotting activity of factors IXG48R and IXG48V was attributed to the failure of both mutants to cleavage factor X: in the presence of only phospholipids and calcium ions, both mutants showed a 4 to approximately 7-fold elevation in Km, and by adding factor VIIIa to the system, although factor VIIIa potentiated the activation of factor X by the mutants factor IXaG48R and factor IXaG48V, a 2 to approximately 3-fold decrease in the catalytic function was observed with the mutant factor IXa's, despite that they bound factor VIIIa on the phospholipid vesicles with only slightly reduced affinity when compared to wild-type factor IXa. The apparent Kd for factor VIIIa binding was 0.83 nM for normal factor IXa, 1.74 nM for IXaG48R and 1.4 nM for IXaG48V. Strikingly, when interaction with the factor VIIa-TF complex was examined, both mutations were barely activated by the VIIa-TF complex and they also showed abnormal interaction with VIIa-TF in bovine

The importance of residues 195-206 of human blood clotting factor VII in the interaction of factor VII with tissue factor

International Nuclear Information System (INIS)

Wildgoose, P.; Kisiel, W.; Kazim, A.L.

1990-01-01

Previous studies indicated that human and bovine factor VII exhibit 71% amino acid sequence identity. In the present study, competition binding experiments revealed that the interaction of human factor VII with cell-surface human tissue factor was not inhibited by 100-fold molar excess of bovine factor VII. This finding indicated that bovine and human factor VII are not structurally homologous in the region(s) where human factor VII interacts with human tissue factor. On this premise, the authors synthesized three peptides corresponding to regions of human factor VII that exhibited marked structural dissimilarity to bovine factor VII; these regions of dissimilarity included residues 195-206, 263-274, and 314-326. Peptide 195-206 inhibited the interaction of factor VII with cell-surface tissue factor and the activation of factor X by a complex of factor VIIa and tissue factor half-maximally at concentrations of 1-2 mM. A structurally rearranged form of peptide 195-206 containing an aspartimide residue inhibited these reactions half-maximally at concentrations of 250-300 μM. In contrast, neither peptide 263-274 nor peptide 314-326, at 2 mM concentration, significantly affected either factor VIIa interaction with tissue factor or factor VIIa-mediated activation of factor X. The data provide presumptive evidence that residues 195-206 of human factor VII are involved in the interaction of human factor VII with the extracellular domain of human tissue factor apoprotein

[Coagulation factor VII levels in uremic patients and theirs influence factors].

Science.gov (United States)

Fang, Jun; Xia, Ling-Hui; Wei, Wen-Ning; Song, Shan-Jun

2004-12-01

This study was aimed to investigate coagulation factor VII level in uremic patients with chronic renal failure and to explore theirs influence factors. The plasma levels of coagulation factor VII were detected in 30 uremic patients with chronic renal failure before and after hemodialysis for 1 month, the factor VII activity (FVII:C) was determined by one-stage coagulation method, while activated factor VII (FVIIa) was measured by one-stage coagulation method using recombinant soluble tissue factor, and factor VII antigen was detected by ELISA. The results showed that: (1) The FVIIa, FVII:C and FVIIAg levels in chronic uremic patients before hemodialysis were 4.00 +/- 0.86 microg/L, (148.5 +/- 40.4)% and (99.8 +/- 21.1)% respectively, which were significantly increased, as compared with healthy controls [2.77 +/- 1.02 microg/L, (113.1 +/- 33.0)% and (73.7 +/- 18.3)% respectively, P factor VII was positively correlated with levels of blood uria nitrogen and serum creatinine before hemodialysis but not after hemodialysis. It is concluded that the enhanced levels of coagulation factor VII in chronic uremic patients suggested abnormal activated state, herperactivity and elevated production of factor VII which correlated with renal functional injury. The abnormality of factor VII in uremia may be aggravated by hemodialysis. Coagulation factor (FVII) may be a risk factor for cardiovascular events in uremic patients who especially had been accepted long-term hemodialysis.

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…

A factor analysis to detect factors influencing building national brand

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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”.

Environmental assessment of Al-Hammar Marsh, Southern Iraq

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Hind Fadhil Abdullah Al-Gburi

2017-02-01

Discussion and conclusions: Decreasing of Tigris and Euphrates discharges during the past decades due to drought conditions and upstream damming, as well as the increasing stress of wastewater effluents from anthropogenic activities, led to degradation of the downstream Al-Hammar Marsh water quality in terms of physical, chemical, and biological properties. As such properties were found to consistently exceed the historical and global quality objectives. However, element concentration decreasing trend at the marsh outlet station compared to other stations indicate that the marsh plays an important role as a natural filtration and bioremediation system. Higher element concentrations in winter were due to runoff from the washing of the surrounding Sabkha during flooding by winter rainstorms. Finally, the high concentrations of heavy metals in fish samples can be attributed to bioaccumulation and biomagnification processes.

Reproductive success and chlorinated hydrocarbon contamination of resident great blue herons (Ardea herodias) from coastal British Columbia, Canada, 1977 to 2000

International Nuclear Information System (INIS)

Harris, M.L.; Elliott, J.E.; Butler, R.W.; Wilson, L.K.

2003-01-01

Human disturbance and loss of nesting habitat were more important factors than chlorinated hydrocarbons in changing heron reproductive success. - Over the period 1977-2000, eggs of Pacific great blue heron (Ardea herodias fannini) were collected from 23 colonies along the southern coast of British Columbia, Canada, and analyzed for persistent organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs). Concentrations of OC pesticides in eggs declined sharply in the late 1970s, after which there were minimal changes. The sums of PCB congeners were not reduced appreciably during the 1980s and 1990s, but Aroclor 1260 concentrations suggested a sharp decline in PCB contamination of eggs in the late 1970s, similar to that shown for OC pesticides. Eggs collected along or near the Fraser River delta showed higher levels of most pesticides compared to other monitored colonies. Although the delta lands support a long-standing agricultural economy, the primary factors influencing OC levels in the delta colonies were thought to be driven by estuarine processes. We suggest two possible influencing factors were: 1) a greater rate of bioaccumulation in the estuary due to the deposition of particulates collected over a vast area encompassed by the Fraser River watershed; or 2) a higher rate of biomagnification in the estuary due to species differences at lower trophic levels of the heron food chain. Eggs from urban colonies contained higher levels of PCBs. The congener pattern was not clearly different from that observed in less contaminated eggs from rural and pulp mill-influenced colonies, except that colonies in Vancouver had greater proportions of PCB-66, suggesting a local source of Aroclor 1242. Productivity in the coastal heron colonies was highly variable over the period of study, with 71% of recorded colony-wide reproductive failures occurring in colonies near pulp mills. However, the predominant factors influencing reproductive success were probably disturbance

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

Quality factors

International Nuclear Information System (INIS)

Kerr, G.D.

1986-01-01

The quality factor, Q, is a dimensionless modifier used in converting absorbed dose, expressed in rads (or grays), to dose equivalent, expressed in rems (or seiverts). The dose equivalent is used in radiation protection to account for the biological effectiveness of different kinds of radiation. The quality factor is related to both the linear energy transfer (LET) and relative biological effectiveness (RBE). The RBE's obtained from biological experiments depend in a complex way on the observed biological effect, the specific test organism, and the experimental conditions. Judgement is involved, therefore, in the choice of the quality factor. Questions regarding the adequacy of current Q values for neutrons were raised first in a 1980 statement by the National Council on Radiation Protection (NCRP) and later in a 1985 statement by the International Commission on Radiological Protection (ICRP). In 1980, the NCRP alerted the technical community to possible future increases between a factor of three and ten in the Q for neutrons, and in 1985, the ICRP suggested an increase by a factor of two in Q for neutrons. Both the ICRP and NRCP are now recommending essentially the same guidance with regard to Q for neutrons: an increase by a factor of two. The Q for neutrons is based on a large, albeit unfocused, body of experimental data. In spite of the lack of focus, the data supporting a change in the neutron quality factor are substantial. However, the proposed doubling of Q for neutrons is clouded by other issues regarding its application. 33 refs., 4 figs., 6 tabs

Kinetics of the Factor XIa catalyzed activation of human blood coagulation Factor IX

International Nuclear Information System (INIS)

Walsh, P.N.; Bradford, H.; Sinha, D.; Piperno, J.R.; Tuszynski, G.P.

1984-01-01

The kinetics of activation of human Factor IX by human Factor XIa was studied by measuring the release of a trichloroacetic acid-soluble tritium-labeled activation peptide from Factor IX. Initial rates of trichloroacetic acid-soluble 3 H-release were linear over 10-30 min of incubation of Factor IX (88 nM) with CaCl 2 (5 mM) and with pure (greater than 98%) Factor XIa (0.06-1.3 nM), which was prepared by incubating human Factor XI with bovine Factor XIIa. Release of 3 H preceded the appearance of Factor IXa activity, and the percentage of 3 H released remained constant when the mole fraction of 3 H-labeled and unlabeled Factor IX was varied and the total Factor IX concentration remained constant. A linear correlation (r greater than 0.98, P less than 0.001) was observed between initial rates of 3 H-release and the concentration of Factor XIa, measured by chromogenic assay and by radioimmunoassay and added at a Factor IX:Factor XIa molar ratio of 70-5,600. Kinetic parameters, determined by Lineweaver-Burk analysis, include K/sub m/ (0.49 microM) of about five- to sixfold higher than the plasma Factor IX concentration, which could therefore regulate the reaction. The catalytic constant (k/sub cat/) (7.7/s) is approximately 20-50 times higher than that reported by Zur and Nemerson for Factor IX activation by Factor VIIa plus tissue factor. Therefore, depending on the relative amounts of Factor XIa and Factor VIIa generated in vivo and other factors which may influence reaction rates, these kinetic parameters provide part of the information required for assessing the relative contributions of the intrinsic and extrinsic pathways to Factor IX activation, and suggest that the Factor XIa catalyzed reaction is physiologically significant

Factoring in Factor VIII With Acute Ischemic Stroke.

Science.gov (United States)

Siegler, James E; Samai, Alyana; Albright, Karen C; Boehme, Amelia K; Martin-Schild, Sheryl

2015-10-01

There is growing research interest into the etiologies of cryptogenic stroke, in particular as it relates to hypercoagulable states. An elevation in serum levels of the procoagulant factor VIII is recognized as one such culprit of occult cerebral infarctions. It is the objective of the present review to summarize the molecular role of factor VIII in thrombogenesis and its clinical use in the diagnosis and prognosis of acute ischemic stroke. We also discuss the utility of screening for serum factor VIII levels among patients at risk for, or those who have experienced, ischemic stroke. © The Author(s) 2015.

Using Bayes factors for multi-factor, biometric authentication

Science.gov (United States)

Giffin, A.; Skufca, J. D.; Lao, P. A.

2015-01-01

Multi-factor/multi-modal authentication systems are becoming the de facto industry standard. Traditional methods typically use rates that are point estimates and lack a good measure of uncertainty. Additionally, multiple factors are typically fused together in an ad hoc manner. To be consistent, as well as to establish and make proper use of uncertainties, we use a Bayesian method that will update our estimates and uncertainties as new information presents itself. Our algorithm compares competing classes (such as genuine vs. imposter) using Bayes Factors (BF). The importance of this approach is that we not only accept or reject one model (class), but compare it to others to make a decision. We show using a Receiver Operating Characteristic (ROC) curve that using BF for determining class will always perform at least as well as the traditional combining of factors, such as a voting algorithm. As the uncertainty decreases, the BF result continues to exceed the traditional methods result.

Electroweak form factors

International Nuclear Information System (INIS)

Singh, S.K.

2002-01-01

The present status of electroweak nucleon form factors and the N - Δ transition form factors is reviewed. Particularly the determination of dipole mass M A in the axial vector form factor is discussed

Estratégia de comercialização em mercados derivativos - descobrimento de base e risco de base da cafeicultura em diversas localidades de Minas Gerais e São Paulo Marketing strategy in derivative markets discovery of the basis and the risk of basis of coffee in several places in Minas Gerais and São Paulo states

Directory of Open Access Journals (Sweden)

Renato Elias Fontes

2005-04-01

Full Text Available Com o presente trabalho tem-se por objetivo geral mensurar os valores da base e do risco de base da atividade cafeeira de importantes cidades produtoras de café localizadas no Estados de Minas Gerais e São Paulo, pois a estratégia de se utilizar os mercados derivativos vem ganhando cada vez mais importância, devido às suas características, que propiciam o feitio de ''hedge'' de preços. Os municípios estudados foram Boa Esperança, Caratinga, Lavras, Machado, Patrocínio, Três Pontas, Varginha e Garça (SP. Os dados primários utilizados sobre o preço da saca de café comercializada no mercado local foram coletados diretamente nas instituições participantes, e o preço do café no mercado futuro foi levantando junto à BM&F. A diversidade dos valores da base e do risco de base encontrada demonstra que cada localidade apresenta características próprias de comercialização, e todas as localidades apresentam valores negativos. A época de comercialização é um importante fator a ser levado em consideração, pois na safra há um fortalecimento da base e o risco de base é menor do que na entressafra, que apresenta um enfraquecimento da base.The general objective of this assignment is to measure the value of the basis and of the risk of basis of the cultivation of coffee in important coffee producer cities from the states of Minas Gerais and São Paulo, for the strategy of using the derivative markets has been obtaining more importance due to its characteristics that provide the hedge of the prices. The cities studied were Boa Esperança, Caratinga, Lavras, Machado, Patrocínio, Três Pontas, Varginha and Garça (SP. The primary data used was, the local price of the coffee bag. The data was collected directly from the participant institutions and the future price of the coffe was raised with the BM&F. The variety of the values of the basis and of the risk of basis found shows that each locality presents its own commerce

Black Carbon Inclusive Multichemical Modeling of PBDE and PCB Biomagnification and -Transformation in Estuarine Food Webs

NARCIS (Netherlands)

Paolo, C.; Gandhi, N.; Bhavsar, S.; Heuvel-Greve, van den M.J.; Koelmans, A.A.

2010-01-01

Bioavailability and bioaccumulation of polybrominated diphenylethers (PBDEs) are affected by adsorption on black carbon (BC) and metabolism in biota, respectively. Recent studies have addressed these two processes separately, illustrating their importance in assessing contaminant dynamics. In order

Application of numerical methods, derivatives theory and Monte Carlo simulation in evaluating BM&F BOVESPA's POP (Protected and Participative Investment

Directory of Open Access Journals (Sweden)

Giuliano Carrozza Uzêda Iorio de Souza

2011-08-01

Full Text Available This article presents a practical case in which two of the most efficient numerical procedures developed for derivative analysis are applied to evaluate the POP (Investment Protection with Participation, a structured operation created by São Paulo Stock Exchange - BM&FBOVESPA. The first procedure solves the differential equation through the use of implicit finite differences method. Due to its characteristics, the approach makes it possible to run sensitivity analysis as well as price estimation. In the second, the problem is solved by Monte Carlo simulation, which facilitates the identification of the probability related to the exercise of the embedded options.

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.

Heparin-binding epidermal growth factor-like growth factor promotes neuroblastoma differentiation.

Science.gov (United States)

Gaviglio, Angela L; Knelson, Erik H; Blobe, Gerard C

2017-05-01

High-risk neuroblastoma is characterized by undifferentiated neuroblasts and low schwannian stroma content. The tumor stroma contributes to the suppression of tumor growth by releasing soluble factors that promote neuroblast differentiation. Here we identify heparin-binding epidermal growth factor-like growth factor (HBEGF) as a potent prodifferentiating factor in neuroblastoma. HBEGF mRNA expression is decreased in human neuroblastoma tumors compared with benign tumors, with loss correlating with decreased survival. HBEGF protein is expressed only in stromal compartments of human neuroblastoma specimens, with tissue from high-stage disease containing very little stroma or HBEGF expression. In 3 human neuroblastoma cell lines (SK-N-AS, SK-N-BE2, and SH-SY5Y), soluble HBEGF is sufficient to promote neuroblast differentiation and decrease proliferation. Heparan sulfate proteoglycans and heparin derivatives further enhance HBEGF-induced differentiation by forming a complex with the epidermal growth factor receptor, leading to activation of the ERK1/2 and STAT3 pathways and up-regulation of the inhibitor of DNA binding transcription factor. These data support a role for loss of HBEGF in the neuroblastoma tumor microenvironment in neuroblastoma pathogenesis.-Gaviglio, A. L., Knelson, E. H., Blobe, G. C. Heparin-binding epidermal growth factor-like growth factor promotes neuroblastoma differentiation. © FASEB.

Tumour Necrosis Factor-alpha and Nuclear Factor-kappa B Gene Variants in Sepsis.

Science.gov (United States)

Acar, Leyla; Atalan, Nazan; Karagedik, E Hande; Ergen, Arzu

2018-01-20

The humoral system is activated and various cytokines are released due to infections in tissues and traumatic damage. Nuclear factor-kappa B dimers are encoded by nuclear factor-kappa B genes and regulate transcription of several crucial proteins of inflammation such as tumour necrosis factor-alpha. To investigate the possible effect of polymorphisms on tumour necrosis factor-alpha serum levels with clinical and prognostic parameters of sepsis by determining the nuclear factor-kappa B-1-94 ins/del ATTG and tumour necrosis factor-alpha (-308 G/A) gene polymorphisms and tumour necrosis factor-alpha serum levels. Case-control study. Seventy-two patients with sepsis and 104 healthy controls were included in the study. In order to determine the polymorphisms of nuclear factor-kappa B-1-94 ins/del ATTG and tumour necrosis factor-alpha (-308 G/A), polymerase chain reaction-restriction fragment length polymorphism analysis was performed and serum tumour necrosis factor-alpha levels were determined using an enzyme-linked immunosorbent assay. We observed no significant differences in tumour necrosis factor-alpha serum levels between the study groups. In the patient group, an increase in the tumour necrosis factor-alpha serum levels in patients carrying the tumour necrosis factor-alpha (-308 G/A) A allele compared to those without the A allele was found to be statistically significant. Additionally, an increase in the tumour necrosis factor-alpha serum levels in patients carrying tumour necrosis factor-alpha (-308 G/A) AA genotype compared with patients carrying the AG or GG genotypes was statistically significant. No significant differences were found in these 2 polymorphisms between the patient and control groups (p>0.05). Our results showed the AA genotype and the A allele of the tumour necrosis factor-alpha (-308 G/A) polymorphism may be used as a predictor of elevated tumour necrosis factor-alpha levels in patients with sepsis.

Growth factors II: insuline-like growth binging proteins (GFBPs Factores de crecimiento II: factores insulinoides de crecimiento

Directory of Open Access Journals (Sweden)

Hilda Norha Jaramillo Londoño

1996-03-01

Full Text Available This review summarizes recent knowledge concerning Insulin.like growth factors I and II, with emphasis on their biochemical structure, concentrations, binding proteins, receptors, mechanisms of action, biological effects, and alterations of their concentrations in biological fluids. Se revisan los Factores Insulinoides de Crecimiento, también denominados ";Factores de Crecimiento Similares a la Insulina";, sobre los cuales se dispone de abundante información. Se sintetizan conocimientos recientes sobre dichos factores con énfasis en los siguientes aspectos: estructura bioquímica, concentraciones y sus cambios en los líquidos biológicos, proteínas fijadoras, receptores, mecanismos de acción y efectos biológicos.

EVALUATING THE IMPORTANCE OF FACTORS IN ANY GIVEN ORDER OF FACTORING.

Science.gov (United States)

Humphreys, L G; Tucker, L R; Dachler, P

1970-04-01

A methodology has been described and illustrated for obtaining an evaluation of the importance of the factors in a particular order of factoring that does not require faotoring beyond that order. For example, one can estimate the intercorrelations of the original measures with the perturbations of the first-order factor held constant or, the reverse, estimate the contribution to the intercorrelations of the originral measures from the first-order factors alone. Similar operations are possible at higher orders.

Robust factorization

DEFF Research Database (Denmark)

Aanæs, Henrik; Fisker, Rune; Åström, Kalle

2002-01-01

Factorization algorithms for recovering structure and motion from an image stream have many advantages, but they usually require a set of well-tracked features. Such a set is in generally not available in practical applications. There is thus a need for making factorization algorithms deal effect...

Heart disease - risk factors

Science.gov (United States)

Heart disease - prevention; CVD - risk factors; Cardiovascular disease - risk factors; Coronary artery disease - risk factors; CAD - risk ... a certain health condition. Some risk factors for heart disease you cannot change, but some you can. ...

The joy of factoring

CERN Document Server

Wagstaff, Samuel S

2013-01-01

This book is about the theory and practice of integer factorization presented in a historic perspective. It describes about twenty algorithms for factoring and a dozen other number theory algorithms that support the factoring algorithms. Most algorithms are described both in words and in pseudocode to satisfy both number theorists and computer scientists. Each of the ten chapters begins with a concise summary of its contents. The book starts with a general explanation of why factoring integers is important. The next two chapters present number theory results that are relevant to factoring. Further on there is a chapter discussing, in particular, mechanical and electronic devices for factoring, as well as factoring using quantum physics and DNA molecules. Another chapter applies factoring to breaking certain cryptographic algorithms. Yet another chapter is devoted to practical vs. theoretical aspects of factoring. The book contains more than 100 examples illustrating various algorithms and theorems. It also co...

A factor analysis to find critical success factors in retail brand

Directory of Open Access Journals (Sweden)

Naser Azad

2013-03-01

Full Text Available The present exploratory study aims to find critical components of retail brand among some retail stores. The study seeks to build a brand name in retail level and looks to find important factors affecting it. Customer behavior is largely influenced when the first retail customer experience is formed. These factors have direct impacts on customer experience and satisfaction in retail industry. The proposed study performs an empirical investigation on two well-known retain stores located in city of Tehran, Iran. Using a sample of 265 people from regular customers, the study uses factor analysis and extracts four main factors including related brand, product benefits, customer welfare strategy and corporate profits using the existing 31 factors in the literature.

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.

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

Electrical tortuosity, Kozeny’s factor and cementation factor modelled for chalk

DEFF Research Database (Denmark)

Katika, Konstantina; Fabricius, Ida Lykke

2015-01-01

saturated core plugs to determine the cementation factor, m. This value differs from the one Archie used to describe his equation and best describes the formation factor based on experimental data. Based on this m, we determine the formation factor, F, and the tortuosity, τ. We use this value of τ...

Tritium in the environment. Knowledge synthesis

International Nuclear Information System (INIS)

2009-01-01

This report first presents the nuclear and physical-chemical properties of tritium and addresses the notions of bioaccumulation, bio-magnification and remanence. It describes and comments the natural and anthropic origins of tritium (natural production, quantities released in the environment in France by nuclear tests, nuclear plants, nuclear fuel processing plants, research centres). It describes how tritium is measured as a free element (sampling, liquid scintillation, proportional counting, enrichment method) or linked to organic matter (combustion, oxidation, helium-3-based measurement). It discusses tritium concentrations noticed in different parts of the environment (soils, continental waters, sea). It describes how tritium is transferred to ecosystems (transfer of atmospheric tritium to ground ecosystems, and to soft water ecosystems). It discusses existing models which describe the behaviour of tritium in ecosystems. It finally describes and comments toxic effects of tritium on living ground and aquatic organisms

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

Risk Factors for Internet Gaming Disorder: Psychological Factors and Internet Gaming Characteristics.

Science.gov (United States)

Rho, Mi Jung; Lee, Hyeseon; Lee, Taek-Ho; Cho, Hyun; Jung, Dong Jin; Kim, Dai-Jin; Choi, In Young

2017-12-27

Background : Understanding the risk factors associated with Internet gaming disorder (IGD) is important to predict and diagnose the condition. The purpose of this study is to identify risk factors that predict IGD based on psychological factors and Internet gaming characteristics; Methods : Online surveys were conducted between 26 November and 26 December 2014. There were 3568 Korean Internet game users among a total of 5003 respondents. We identified 481 IGD gamers and 3087 normal Internet gamers, based on Diagnostic and Statistical Manual for Mental Disorders (DSM-5) criteria. Logistic regression analysis was applied to identify significant risk factors for IGD; Results : The following eight risk factors were found to be significantly associated with IGD: functional and dysfunctional impulsivity (odds ratio: 1.138), belief self-control (1.034), anxiety (1.086), pursuit of desired appetitive goals (1.105), money spent on gaming (1.005), weekday game time (1.081), offline community meeting attendance (2.060), and game community membership (1.393; p < 0.05 for all eight risk factors); Conclusions : These risk factors allow for the prediction and diagnosis of IGD. In the future, these risk factors could also be used to inform clinical services for IGD diagnosis and treatment.

In vitro to in vivo extrapolation of biotransformation rates for assessing bioaccumulation of hydrophobic organic chemicals in mammals.

Science.gov (United States)

Lee, Yung-Shan; Lo, Justin C; Otton, S Victoria; Moore, Margo M; Kennedy, Chris J; Gobas, Frank A P C

2017-07-01

Incorporating biotransformation in bioaccumulation assessments of hydrophobic chemicals in both aquatic and terrestrial organisms in a simple, rapid, and cost-effective manner is urgently needed to improve bioaccumulation assessments of potentially bioaccumulative substances. One approach to estimate whole-animal biotransformation rate constants is to combine in vitro measurements of hepatic biotransformation kinetics with in vitro to in vivo extrapolation (IVIVE) and bioaccumulation modeling. An established IVIVE modeling approach exists for pharmaceuticals (referred to in the present study as IVIVE-Ph) and has recently been adapted for chemical bioaccumulation assessments in fish. The present study proposes and tests an alternative IVIVE-B technique to support bioaccumulation assessment of hydrophobic chemicals with a log octanol-water partition coefficient (K OW ) ≥ 4 in mammals. The IVIVE-B approach requires fewer physiological and physiochemical parameters than the IVIVE-Ph approach and does not involve interconversions between clearance and rate constants in the extrapolation. Using in vitro depletion rates, the results show that the IVIVE-B and IVIVE-Ph models yield similar estimates of rat whole-organism biotransformation rate constants for hypothetical chemicals with log K OW  ≥ 4. The IVIVE-B approach generated in vivo biotransformation rate constants and biomagnification factors (BMFs) for benzo[a]pyrene that are within the range of empirical observations. The proposed IVIVE-B technique may be a useful tool for assessing BMFs of hydrophobic organic chemicals in mammals. Environ Toxicol Chem 2017;36:1934-1946. © 2016 SETAC. © 2016 SETAC.

A comparison of mercury levels in feathers and eggs of osprey (Pandion haliaetus) in the North American Great Lakes.

Science.gov (United States)

Hughes, K D; Ewins, P J; Clark, K E

1997-11-01

Osprey (Pandion haliaetus) eggs and chick feathers were collected for mercury analysis from nests at four Great Lakes study areas in Ontario (three "naturally formed" lakes in southern Ontario and one reservoir in northern Ontario) and two New Jersey study areas in 1991-1994. Adult osprey feathers were sampled from three Great Lakes study areas in 1991. Feathers sampled from chicks (approximately 28-35 days old) appear to be better indicators of local contaminant conditions since spatial patterns of mercury in known prey, yellow perch (Perca flavescens), also collected in these areas, were more similar to chick feathers than to eggs. Mercury levels were less variable in chick feathers than in eggs. Estimates of biomagnification factors using prey of known size at these areas were also less variable in feathers than in eggs. At naturally formed lakes, no significant correlation in mercury levels between eggs and chick feathers from the same nest was apparent, suggesting that the source of mercury contamination was not the same in these two tissues: mercury levels in eggs reflect mercury acquired on the breeding grounds, wintering grounds, and migratory route; mercury levels in chick feathers reflect local dietary conditions on the breeding grounds. Mercury levels in both osprey eggs and chick feathers were higher at the Ogoki Reservoir than at naturally formed lakes. Adult osprey feathers had higher mercury concentrations than chick feathers. Mercury levels in osprey eggs, chick feathers, and adult feathers did not approach levels associated with toxic reproductive effects.

Synergistic effect of factor VII gene polymorphisms causing mild factor VII deficiency in a case of severe factor X deficiency.

Science.gov (United States)

Deshpande, Rutuja; Ghosh, Kanjaksha; Shetty, Shrimati

2017-01-01

Congenital combined deficiency of coagulation factors VII and X are mainly attributed to large deletions involving both the genes in chromosome 13 or occasionally due to the coincidental occurrence of independently occurring mutations. We report the molecular basis of congenital combined deficiency of factors VII and X in a 6-year-old female child. Direct DNA sequencing of both factor VII (F7) and factor X (F10) genes showed a novel homozygous missense mutation p.Cys90Tyr (c.307G>A) in exon 4 of F10. No mutations were detected in F7; however, the patient was homozygous for three polymorphic alleles known to be associated with reduced factor VII levels. The present case illustrates the synergistic effect of multiple polymorphisms resulting in phenotypic factor VII deficiency in the absence of a pathogenic mutation.

Mesonic Form Factors

Energy Technology Data Exchange (ETDEWEB)

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

2003-07-22

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.

Constructivism, Factoring, and Beliefs.

Science.gov (United States)

Rauff, James V.

1994-01-01

Discusses errors made by remedial intermediate algebra students in factoring polynomials in light of student definitions of factoring. Found certain beliefs about factoring to logically imply many of the errors made. Suggests that belief-based teaching can be successful in teaching factoring. (16 references) (Author/MKR)

Components of WWER engineering factors for peaking factors: status and trends

International Nuclear Information System (INIS)

Tsyganov, S.V.

2010-01-01

One of the topics for discussion at special working group 'Elaboration of the methodology for calculating the core design engineering factors' is the problem of engineering factor components. The list of components corresponds to the phenomena that are taken into account with the engineering factor. It is supposed the better understanding of the influenced phenomena is important stage for developing unified methodology. This paper presents some brief overview of components of the engineering factor for VVER core peaking factors as they are in the Kurchatov Institute methodology. The evolution of some components to less conservative values is observed. Author makes some assumptions as for the further progress in components assessment. The engineering factors providing observance of design limits at normal operation, should cover, with the set probability, the uncertainty, connected with process of core design. For definition of the value of factors it is necessary to define influence of these uncertainties on the investigated parameter of the reactor. Practice consists in defining all possible sources of uncertainties, to estimate influence of each of them, and on their basis to define total influence of all uncertainties. The important stage of a technique of factor calculation is a definition of the list influencing uncertainties. It is obvious that all characteristics of VVER core are known with some uncertainty-owing to manufacturing tolerances, the measurement errors, etc. However essential influence on the parameters connected with safety, render only a part from them. At list formation those characteristics get out only, whose influence is essential to the corresponding parameter. (Author)

Risk Factors for Internet Gaming Disorder: Psychological Factors and Internet Gaming Characteristics

Directory of Open Access Journals (Sweden)

Mi Jung Rho

2017-12-01

Full Text Available Background: Understanding the risk factors associated with Internet gaming disorder (IGD is important to predict and diagnose the condition. The purpose of this study is to identify risk factors that predict IGD based on psychological factors and Internet gaming characteristics; Methods: Online surveys were conducted between 26 November and 26 December 2014. There were 3568 Korean Internet game users among a total of 5003 respondents. We identified 481 IGD gamers and 3087 normal Internet gamers, based on Diagnostic and Statistical Manual for Mental Disorders (DSM-5 criteria. Logistic regression analysis was applied to identify significant risk factors for IGD; Results: The following eight risk factors were found to be significantly associated with IGD: functional and dysfunctional impulsivity (odds ratio: 1.138, belief self-control (1.034, anxiety (1.086, pursuit of desired appetitive goals (1.105, money spent on gaming (1.005, weekday game time (1.081, offline community meeting attendance (2.060, and game community membership (1.393; p < 0.05 for all eight risk factors; Conclusions: These risk factors allow for the prediction and diagnosis of IGD. In the future, these risk factors could also be used to inform clinical services for IGD diagnosis and treatment.

Risk Factors for Internet Gaming Disorder: Psychological Factors and Internet Gaming Characteristics

Science.gov (United States)

Lee, Hyeseon; Lee, Taek-Ho; Cho, Hyun; Kim, Dai-Jin; Choi, In Young

2017-01-01

Background: Understanding the risk factors associated with Internet gaming disorder (IGD) is important to predict and diagnose the condition. The purpose of this study is to identify risk factors that predict IGD based on psychological factors and Internet gaming characteristics; Methods: Online surveys were conducted between 26 November and 26 December 2014. There were 3568 Korean Internet game users among a total of 5003 respondents. We identified 481 IGD gamers and 3087 normal Internet gamers, based on Diagnostic and Statistical Manual for Mental Disorders (DSM-5) criteria. Logistic regression analysis was applied to identify significant risk factors for IGD; Results: The following eight risk factors were found to be significantly associated with IGD: functional and dysfunctional impulsivity (odds ratio: 1.138), belief self-control (1.034), anxiety (1.086), pursuit of desired appetitive goals (1.105), money spent on gaming (1.005), weekday game time (1.081), offline community meeting attendance (2.060), and game community membership (1.393; p < 0.05 for all eight risk factors); Conclusions: These risk factors allow for the prediction and diagnosis of IGD. In the future, these risk factors could also be used to inform clinical services for IGD diagnosis and treatment. PMID:29280953

Recombinant factor VIIa treatment for asymptomatic factor VII deficient patients going through major surgery.

Science.gov (United States)

Livnat, Tami; Shenkman, Boris; Spectre, Galia; Tamarin, Ilia; Dardik, Rima; Israeli, Amnon; Rivkind, Avraham; Shabtai, Moshe; Marinowitz, Uri; Salomon, Ophira

2012-07-01

Factor VII deficiency is the most common among the rare autosomal recessive coagulation disorders worldwide. In factor VII deficient patients, the severity and clinical manifestations cannot be reliably determined by factor VII levels. Severe bleeding tends to occur in individuals with factor VII activity levels of 2% or less of normal. Patients with 2-10% factor VII vary between asymptomatic to severe life threatening haemorrhages behaviour. Recombinant factor VIIa (rFVIIa) is the most common replacement therapy for congenital factor VII deficiency. However, unlike haemophilia patients for whom treatment protocols are straight forward, in asymptomatic factor VII deficiency patients it is still debatable. In this study, we demonstrate that a single and very low dose of recombinant factor VIIa enabled asymptomatic patients with factor VII deficiency to go through major surgery safely. This suggestion was also supported by thrombin generation, as well as by thromboelastometry.

Blood coagulation factor VIII

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 ...

Production and properties of monoclonal antibodies to human blood coagulation factor VII and factor VIIa

International Nuclear Information System (INIS)

Mann, P.; Nesbitt, J.A.; Ge, M.; Kisiel, W.

1986-01-01

Human factor VII is a trace vitamin K-dependent protein that circulates in blood as a single-chain precursor to a serine protease. Upon activation, two-chain factor VIIa activates factor x in the presence of tissue factor and calcium. Purified preparations of single-chain (SC) human factor VII and two-chain (TC) factor VIIa were utilized to immunize Balb/c mice. Spleen cells from these immunized mice were fused to a non-secreting NS-1 derivative of X63-Ag8 myeloma cells and grown in selective medium. Analysis of culture supernatants by EIA revealed several hybridomas that were secreting IgG specific for Sc-factor VII and TC-factor VIIa. In addition, several hybridomas secreted IgG that reacted equally well with factor VII and factor VIIa. One of the latter McAb (A-29) reacted with the heavy chain of factor VIIa and the intact factor VII molecule equally as judged by Western blotting. A-29 was produced in ascites fluid, purified and coupled to activated CH-Sepharose. Application of one liter of normal human plasma to 10 ml of this immunoadsorbent column, elution of factor VII and subsequent Western blot using 125 I-rabbit anti-human factor VII indicated a single species of factor VII(M/sub r/ = 50 KDa) in normal plasma. These specific factor VII/VIIa McAbs may prove useful in the analysis of these factors, and in the separation of SC-factor VII from TC-factor VIIa

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.)

Foundations of factor analysis

CERN Document Server

Mulaik, Stanley A

2009-01-01

Introduction Factor Analysis and Structural Theories Brief History of Factor Analysis as a Linear Model Example of Factor AnalysisMathematical Foundations for Factor Analysis Introduction Scalar AlgebraVectorsMatrix AlgebraDeterminants Treatment of Variables as Vectors Maxima and Minima of FunctionsComposite Variables and Linear Transformations Introduction Composite Variables Unweighted Composite VariablesDifferentially Weighted Composites Matrix EquationsMulti

Dynamic Multi-Factor Credit Risk Model with Fat-Tailed Factors

Czech Academy of Sciences Publication Activity Database

Gapko, Petr; Šmíd, Martin

2012-01-01

Roč. 62, č. 2 (2012), s. 125-140 ISSN 0015-1920 R&D Projects: GA ČR GD402/09/H045; GA ČR GA402/09/0965 Grant - others:Univerzita Karlova(CZ) GAUK 46108 Institutional research plan: CEZ:AV0Z10750506 Keywords : credit risk * probability of default * loss given default * credit loss * credit loss distribution * Basel II Subject RIV: AH - Economics Impact factor: 0.340, year: 2012 http://library.utia.cas.cz/separaty/2012/E/smid-dynamic multi-factor credit risk model with fat-tailed factors.pdf

Oversimplifying quantum factoring.

Science.gov (United States)

Smolin, John A; Smith, Graeme; Vargo, Alexander

2013-07-11

Shor's quantum factoring algorithm exponentially outperforms known classical methods. Previous experimental implementations have used simplifications dependent on knowing the factors in advance. However, as we show here, all composite numbers admit simplification of the algorithm to a circuit equivalent to flipping coins. The difficulty of a particular experiment therefore depends on the level of simplification chosen, not the size of the number factored. Valid implementations should not make use of the answer sought.

Elevated plasma factor VIII enhances venous thrombus formation in rabbits: contribution of factor XI, von Willebrand factor and tissue factor.

Science.gov (United States)

Sugita, Chihiro; Yamashita, Atsushi; Matsuura, Yunosuke; Iwakiri, Takashi; Okuyama, Nozomi; Matsuda, Shuntaro; Matsumoto, Tomoko; Inoue, Osamu; Harada, Aya; Kitazawa, Takehisa; Hattori, Kunihiro; Shima, Midori; Asada, Yujiro

2013-07-01

Elevated plasma levels of factor VIII (FVIII) are associated with increased risk of deep venous thrombosis. The aim of this study is to elucidate how elevated FVIII levels affect venous thrombus formation and propagation in vivo. We examined rabbit plasma FVIII activity, plasma thrombin generation, whole blood coagulation, platelet aggregation and venous wall thrombogenicity before and one hour after an intravenous infusion of recombinant human FVIII (rFVIII). Venous thrombus induced by the endothelial denudation of rabbit jugular veins was histologically assessed. Thrombus propagation was evaluated as indocyanine green fluorescence intensity. Argatroban, a thrombin inhibitor, and neutralised antibodies for tissue factor (TF), factor XI (FXI), and von Willebrand factor (VWF) were infused before or after thrombus induction to investigate their effects on venous thrombus formation or propagation. Recombinant FVIII (100 IU/kg) increased rabbit plasma FVIII activity two-fold and significantly enhanced whole blood coagulation and total plasma thrombin generation, but did not affect initial thrombin generation time, platelet aggregation and venous wall thrombogenicity. The rFVIII infusion also increased the size of venous thrombus 1 hour after thrombus induction. Argatroban and the antibodies for TF, FXI or VWF inhibited such enhanced thrombus formation and all except TF suppressed thrombus propagation. In conclusion, elevated plasma FVIII levels enhance venous thrombus formation and propagation. Excess thrombin generation by FXI and VWF-mediated FVIII recruitment appear to contribute to the growth of FVIII-driven venous thrombus.

UV filters bioaccumulation in fish from Iberian river basins

Energy Technology Data Exchange (ETDEWEB)

Gago-Ferrero, Pablo [Dept. of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, E-08034 Barcelona (Spain); Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Athens (Greece); Díaz-Cruz, M. Silvia, E-mail: sdcqam@cid.csic.es [Dept. of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, E-08034 Barcelona (Spain); Barceló, Damià [Dept. of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, E-08034 Barcelona (Spain); Catalan Institute for Water Research (ICRA), Parc Científic i Tecnològic de la Universitat de Girona, C/ Emili Grahit, 101 Edifici H2O, E-17003 Girona (Spain)

2015-06-15

The occurrence of eight organic UV filters (UV-Fs) was assessed in fish from four Iberian river basins. This group of compounds is extensively used in cosmetic products and other industrial goods to avoid the damaging effects of UV radiation, and has been found to be ubiquitous contaminants in the aquatic ecosystem. In particular, fish are considered by the scientific community to be the most feasible organism for contamination monitoring in aquatic ecosystems. Despite that, studies on the bioaccumulation of UV-F are scarce. In this study fish samples from four Iberian river basins under high anthropogenic pressure were analysed by liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Benzophenone-3 (BP3), ethylhexyl methoxycinnamate (EHMC), 4-methylbenzylidene camphor (4MBC) and octocrylene (OC) were the predominant pollutants in the fish samples, with concentrations in the range of ng/g dry weight (d.w.). The results indicated that most polluted area corresponded to Guadalquivir River basin, where maximum concentrations were found for EHMC (241.7 ng/g d.w.). Sediments from this river basin were also analysed. Lower values were observed in relation to fish for OC and EHMC, ranging from below the limits of detection to 23 ng/g d.w. Accumulation levels of UV-F in the fish were used to calculate biota-sediment accumulation factors (BSAFs). These values were always below 1, in the range of 0.04–0.3, indicating that the target UV-Fs are excreted by fish only to some extent. The fact that the highest concentrations were determined in predators suggests that biomagnification of UV-F may take place along the freshwater food web. - Highlights: • First evidence of UV filters in fish from Iberian rivers • Biota-sediment accumulation factors (BSAFs) were always below 1. • Predator species presented higher UV-F concentrations suggesting trophic magnification.

UV filters bioaccumulation in fish from Iberian river basins

International Nuclear Information System (INIS)

Gago-Ferrero, Pablo; Díaz-Cruz, M. Silvia; Barceló, Damià

2015-01-01

The occurrence of eight organic UV filters (UV-Fs) was assessed in fish from four Iberian river basins. This group of compounds is extensively used in cosmetic products and other industrial goods to avoid the damaging effects of UV radiation, and has been found to be ubiquitous contaminants in the aquatic ecosystem. In particular, fish are considered by the scientific community to be the most feasible organism for contamination monitoring in aquatic ecosystems. Despite that, studies on the bioaccumulation of UV-F are scarce. In this study fish samples from four Iberian river basins under high anthropogenic pressure were analysed by liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Benzophenone-3 (BP3), ethylhexyl methoxycinnamate (EHMC), 4-methylbenzylidene camphor (4MBC) and octocrylene (OC) were the predominant pollutants in the fish samples, with concentrations in the range of ng/g dry weight (d.w.). The results indicated that most polluted area corresponded to Guadalquivir River basin, where maximum concentrations were found for EHMC (241.7 ng/g d.w.). Sediments from this river basin were also analysed. Lower values were observed in relation to fish for OC and EHMC, ranging from below the limits of detection to 23 ng/g d.w. Accumulation levels of UV-F in the fish were used to calculate biota-sediment accumulation factors (BSAFs). These values were always below 1, in the range of 0.04–0.3, indicating that the target UV-Fs are excreted by fish only to some extent. The fact that the highest concentrations were determined in predators suggests that biomagnification of UV-F may take place along the freshwater food web. - Highlights: • First evidence of UV filters in fish from Iberian rivers • Biota-sediment accumulation factors (BSAFs) were always below 1. • Predator species presented higher UV-F concentrations suggesting trophic magnification

Mechanisms of60Co uptake and loss by Scenedesmus obliquus and transfer to two benthic organisms

International Nuclear Information System (INIS)

Nucho, R.

1989-10-01

The affinity of Scenedesmus obliquus for 60 Co has been confirmed under various experimental conditions allowing for the age of cultures, the physiological state of the cells, the radioactivity level and stable cobalt concentration in the medium, and the acute or periodic nature of the contamination. The dry weight 60 Co concentration factor may reach 4x10 4 in LCO culture medium and is about 10 4 in natural water. 60 Co uptake by algae is a 95% passive phenomenon, initiated by radionuclide absorption on the cell walls and followed by intracellular diffusion in accordance with Fick's law. From the initial cationic form, radiocobalt develops anion forms at a rate proportional to the algal biomass, resulting in lower contamination of old and dense cultures. After transfer in natural or artificial nonradioctive medium, 60 Co is eliminated by Scenedesmus obliquus, mainly as Co 2+ ions, according to a two-phase exponential process with two biological half-lives. The study of radioactive cobalt transfer from algae to gammarids and to midge larvae reveals the extend to which phytoplankton predominate over water and sediment in contaminating these two organisms. The total 60 Co uptake depends significantly on whether the cells are incorporated in or deposited on the sediment. No biomagnification phenomenon of the radionuclide was found in any case, as the transfer factor was less than 1. Depuration of 60 Co by organisms involved a two-phase exponential process regardless of whether uptake occured directly or from food. The presence of sediment appears to reduce the 60 Co desorption rate, but from 85 to 95% of the initial quantity is eliminated. This percentage does not depend on the transfer pathway or the presence of organic matter, and indicates very slight assimilation of radiocobalt ingested with algal cells [fr

El factoring

Directory of Open Access Journals (Sweden)

Alberto Rosenthal

2015-04-01

Full Text Available RESUMEN Se presenta la segunda parte del artículo aparecido en  el número 6 de la revista EAN. Su contenido es complementario a lo expuesto en dicho número, en está aparecen las ventajas del factoring, conveniencias, limitaciones así como la forma  de efectuar un factor en Colombia,  su necesidad, incidencia económica, etc.

Hematopoietic cell transplantation in Fanconi anemia: current evidence, challenges and recommendations.

Science.gov (United States)

Ebens, Christen L; MacMillan, Margaret L; Wagner, John E

2017-01-01

Hematopoietic cell transplantation for Fanconi Anemia (FA) has improved dramatically over the past 40 years. With an enhanced understanding of the intrinsic DNA-repair defect and pathophysiology of hematopoietic failure and leukemogenesis, sequential changes to conditioning and graft engineering have significantly improved the expectation of survival after allogeneic hematopoietic cell transplantation (alloHCT) with incidence of graft failure decreased from 35% to 40% to <10%. Today, five-year overall survival exceeds 90% in younger FA patients with bone marrow failure but remains about 50% in those with hematologic malignancy. Areas covered: We review the evolution of alloHCT contributing to decreased rates of transplant related complications; highlight current challenges including poorer outcomes in cases of clonal hematologic disorders, alloHCT impact on endocrine function and intrinsic FA risk of epithelial malignancies; and describe investigational therapies for prevention and treatment of the hematologic manifestations of FA. Expert commentary: Current methods allow for excellent survival following alloHCT for FA associated BMF irrespective of donor hematopoietic cell source. Alternative curative approaches, such as gene therapy, are being explored to eliminate the risks of GVHD and minimize therapy-related adverse effects.

DETERMINANTES DO P/B, SETOR REGULADO E ESTRATÉGIAS DE INVESTIMENTO

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Ricardo Goulart Serra

2016-03-01

Full Text Available Observou-se uma lacuna de estudos em finanças que analise os determinantes do Price to Book (P/B para o período mais recente. Por meio de uma análise de painel, para 168 empresas com ações listadas na BMF&Bovespa e pelos últimos 40 trimestres, identificou-se os determinantes: (i retorno (relação positiva, (ii crescimento histórico (relação positiva, (iii custo de capital, medido pelo beta e alavancagem (ambos com relação negativa e (iv tamanho (positiva além de um determinante não usual: (v pertencer a um setor regulado (negativa, o que contribui com estudos sobre setores regulados. O fato das empresas pertencentes a setores regulados terem menor P/B pode ser um bom ou um mau sinal. Além disso, observou-se, analisando o Índice de Sharpe, a superioridade da estratégia de investimento em empresas com baixo P/B. Estratégias com outras variáveis também foram testadas, entre elas: tamanho, beta e retorno, de forma a contribuir com as pesquisas sobre o tema.

Factorization of heavy-to-light form factors in soft-collinear effective theory

CERN Document Server

Beneke, Martin; Feldmann, Th.

2004-01-01

Heavy-to-light transition form factors at large recoil energy of the light meson have been conjectured to obey a factorization formula, where the set of form factors is reduced to a smaller number of universal form factors up to hard-scattering corrections. In this paper we extend our previous investigation of heavy-to-light currents in soft-collinear effective theory to final states with invariant mass Lambda^2 as is appropriate to exclusive B meson decays. The effective theory contains soft modes and two collinear modes with virtualities of order m_b*Lambda (`hard-collinear') and Lambda^2. Integrating out the hard-collinear modes results in the hard spectator-scattering contributions to exclusive B decays. We discuss the representation of heavy-to-light currents in the effective theory after integrating out the hard-collinear scale, and show that the previously conjectured factorization formula is valid to all orders in perturbation theory. The naive factorization of matrix elements in the effective theory ...

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...

Risks factoring business: accounting measurement

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Z.V. Gutsaylyuk

2015-06-01

Full Text Available The paper carried out the identification of risk factors for the development of possible accounting software management. Studied theoretical and methodological aspects of the risk classification of factoring operations in the part of the risk assessment factors. It is proposed to consider the risks factors as the risk that is acceptable controlled by accounting instruments and the risks that can not be taken into account in the accounting records. To minimize the risk factor, accounting-driven tools, a method of self-insurance, which is a factor in the creation of provision for factoring transactions designed to cover unexpected expenses and losses. Provision for factoring factor will establish more stable conditions of financial activity and avoid the fluctuations of profit factor in relation to the writing off of losses on factoring operatsіyam.Developed proposals allow for further research to improve the organizational and methodological basis of accounting and analysis of information as a basis for providing risk management factor, particularly in terms of improving the evaluation questions such risks and their qualitative and quantitative analysis.

Risk analysis-based food safety policy: scientific factors versus socio-cultural factors

NARCIS (Netherlands)

Rosa, P.; Knapen, van F.; Brom, F.W.A.

2008-01-01

The purpose of this article is to illustrate the importance of socio-cultural factors in risk management and the need to incorporate these factors in a standard, internationally recognized (wto) framework. This was achieved by analysing the relevance of these factors in 3 cases
The purpose of

Structuring factoring business: accounting aspects

Directory of Open Access Journals (Sweden)

I.M. Vygivska

2017-08-01

Full Text Available The article theoretically substantiates the fact that factoring belongs to the main operational activity of a factoring company, and this allowed structuring the factoring business by types of activity. The lack of a unified approach to the classification of factoring (factoring services made it possible to systematize and refine their classification as a basis for developing accounting and analytical support for risk management of factoring business. The authors single out such classification signs as: the right of the reverse claim (reverse, irretrievable, a territorial feature (international, internal, the subject of the factoring contract (real, consensual, the availability of notification of the debtor (conventional, confidential. The structuring of factoring business contributes to the identification of the risks of the economic activities of a factoring company depending on the type of factoring, the development of methodological support for the bookkeeping of factoring transactions in a risk environment, the search for risk management practices and the determination of management effectiveness in general.

What Are Rare Clotting Factor Deficiencies?

Science.gov (United States)

... Deficiency Factor V Deficiency Combined FV & FVIII Deficiencies Factor VII Deficiency Factor X Deficiency Factor XI Deficiency Factor ... Deficiency Factor V Deficiency Combined FV & FVIII Deficiencies Factor VII Deficiency Factor X Deficiency Factor XI Deficiency Factor ...

Risk Factors for Scleroderma

Science.gov (United States)

... You are here: Home For Patients Risk Factors Risk Factors for Scleroderma The cause of scleroderma is ... what biological factors contribute to scleroderma pathogenesis. Genetic Risk Scleroderma does not tend to run in families ...

Risk Factors and Prevention

Science.gov (United States)

... Resources Risk Factors & Prevention Back to Patient Resources Risk Factors & Prevention Even people who look healthy and ... Blood Pressure , high cholesterol, diabetes, and thyroid disease. Risk Factors For Arrhythmias and Heart Disease The following ...

Factor VII deficiency

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/000548.htm Factor VII deficiency To use the sharing features on this page, please enable JavaScript. Factor VII (seven) deficiency is a disorder caused by a ...

Stroke - risk factors

Science.gov (United States)

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

Neutron electromagnetic form factors

International Nuclear Information System (INIS)

Finn, J.M.; Madey, R.; Eden, T.; Markowitz, P.; Rutt, P.M.; Beard, K.; Anderson, B.D.; Baldwin, A.R.; Keane, D.; Manley, D.M.; Watson, J.W.; Zhang, W.M.; Kowalski, S.; Bertozzi, W.; Dodson, G.; Farkhondeh, M.; Dow, K.; Korsch, W.; Tieger, D.; Turchinetz, W.; Weinstein, L.; Gross, F.; Mougey, J.; Ulmer, P.; Whitney, R.; Reichelt, T.; Chang, C.C.; Kelly, J.J.; Payerle, T.; Cameron, J.; Ni, B.; Spraker, M.; Barkhuff, D.; Lourie, R.; Verst, S.V.; Hyde-Wright, C.; Jiang, W.-D.; Flanders, B.; Pella, P.; Arenhoevel, H.

1992-01-01

Nucleon form factors provide fundamental input for nuclear structure and quark models. Current knowledge of neutron form factors, particularly the electric form factor of the neutron, is insufficient to meet these needs. Developments of high-duty-factor accelerators and polarization-transfer techniques permit new experiments that promise results with small sensitivities to nuclear models. We review the current status of the field, our own work at the MIT/Bates linear accelerator, and future experimental efforts

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

Insulin-like growth factors act synergistically with basic fibroblast growth factor and nerve growth factor to promote chromaffin cell proliferation

DEFF Research Database (Denmark)

Frödin, M; Gammeltoft, S

1994-01-01

We have investigated the effects of insulin-like growth factors (IGFs), basic fibroblast growth factor (bFGF), and nerve growth factor (NGF) on DNA synthesis in cultured chromaffin cells from fetal, neonatal, and adult rats by using 5-bromo-2'-deoxyuridine (BrdUrd) pulse labeling for 24 or 48 h...... implications for improving the survival of chromaffin cell implants in diseased human brain....

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.

Factors in Agile Methods Adoption

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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.

Concentrations of 17 elements, including mercury, in the tissues, food and abiotic environment of Arctic shorebirds

Energy Technology Data Exchange (ETDEWEB)

Hargreaves, Anna L., E-mail: alhargreaves@gmail.com [Calgary Zoo, Centre for Conservation Research, 1300 Zoo Rd NE, Calgary, AB, T2E 7V6 (Canada); Whiteside, Douglas P. [Calgary Zoo, Animal Health Centre, 1300 Zoo Rd NE, Calgary, AB, T2E 7V6 (Canada); University of Calgary, Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, 2500 University Dr. NW, Calgary, AB, T2N 1N4 (Canada); Gilchrist, Grant [Carleton University, National Wildlife Research Centre, Ottawa, ON, KIA OH3 (Canada)

2011-09-01

Exposure to contaminants is one hypothesis proposed to explain the global decline in shorebirds, and is also an increasing concern in the Arctic. We assessed potential contaminants (As, Be, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Tl, V, and Zn) at a shorebird breeding site in Nunavut, Canada. We compared element levels in soil, invertebrates and shorebird blood to assess evidence for bioconcentration and biomagnification within the Arctic-based food chain. We tested whether elements in blood, feathers and eggs of six shorebird species (Pluvialis squatarola, Calidris alpina, C. fuscicollis, Phalaropus fulicarius, Charadrius semipalmatus, and Arenaria interpres) were related to fitness endpoints: adult body condition, blood-parasite load, egg size, eggshell thickness, nest duration, and hatching success. To facilitate comparison to other sites, we summarise the published data on toxic metals in shorebird blood and egg contents. Element concentrations and invertebrate composition differed strongly among habitats, and habitat use and element concentrations differed among shorebird species. Hg, Se, Cd, Cu, and Zn bioconcentrated from soil to invertebrates, and Hg, Se and Fe biomagnified from invertebrates to shorebird blood. As, Ni, Pb, Co and Mn showed significant biodilution from soil to invertebrates to shorebirds. Soil element levels were within Canadian guidelines, and invertebrate Hg levels were below dietary levels suggested for the protection of wildlife. However, maximum Hg in blood and eggs approached levels associated with toxicological effects and Hg-pollution in other bird species. Parental blood-Hg was negatively related to egg volume, although the relationship varied among species. No other elements approached established toxicological thresholds. In conclusion, whereas we found little evidence that exposure to elements at this site is leading to the declines of the species studied, Hg, as found elsewhere in the Canadian Arctic, is of potential

Initial Impacts of the Mount Polley Tailings Pond Breach on Adjacent Aquatic Ecosystems

Science.gov (United States)

Petticrew, Ellen; Gantner, Nikolaus; Albers, Sam; Owens, Philip

2015-04-01

On August 4th 2014, the Mount Polley Tailings pond breach near Likely, B.C., released approximately 24 million cubic metres of tailings material into Polley Lake, Hazeltine Creek and Quesnel Lake. The discharge scoured and eroded a swath of soil and sediment delivering an unknown amount of metals and sediment into this tributary ecosystem of the Fraser River. Subsequent efforts by the mine operator to remediate by pumping tailings water from Polley Lake into Hazeltine Creek, which flows into Quesnel Lake, resulted in additional and continuous release of unknown volumes of contaminated water and sediments into the watershed. Heavy metals (e.g., selenium, copper, or mercury) reported as stored in the tailings pond entered the downstream aquatic environment and have been monitored in the water column of Quesnel Lake since August. These contaminants are likely particle-bound and thus subject to transport over long distances without appreciable degradation, resulting in the potential for chronic exposures and associated toxicological effects in exposed biota. While significant dilution is expected during aquatic transport, and the resulting concentrations in the water will likely be low, concentrations in exposed biota may become of concern over time. Metals such as mercury and selenium undergo bioaccumulation and biomagnification, once incorporated into the food chain/web. Thus, even small concentrations of such contaminants in water can lead to greater concentrations (~100 fold) in top predators. Over time, our predictions are that food web transfer will lead to an increase in concentrations from water (1-2 years)->invertebrates (1-2 yrs) ->fishes (2-5 yrs). Pacific salmon travel great distances in this watershed and may be exposed to contaminated water during their migrations. Resident species will be exposed to the contaminated waters and sediments in the study lakes year round. Little or no background/baseline data for metals in biota from Quesnel Lake exists

Concentrations of 17 elements, including mercury, in the tissues, food and abiotic environment of Arctic shorebirds

International Nuclear Information System (INIS)

Hargreaves, Anna L.; Whiteside, Douglas P.; Gilchrist, Grant

2011-01-01

Exposure to contaminants is one hypothesis proposed to explain the global decline in shorebirds, and is also an increasing concern in the Arctic. We assessed potential contaminants (As, Be, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Tl, V, and Zn) at a shorebird breeding site in Nunavut, Canada. We compared element levels in soil, invertebrates and shorebird blood to assess evidence for bioconcentration and biomagnification within the Arctic-based food chain. We tested whether elements in blood, feathers and eggs of six shorebird species (Pluvialis squatarola, Calidris alpina, C. fuscicollis, Phalaropus fulicarius, Charadrius semipalmatus, and Arenaria interpres) were related to fitness endpoints: adult body condition, blood-parasite load, egg size, eggshell thickness, nest duration, and hatching success. To facilitate comparison to other sites, we summarise the published data on toxic metals in shorebird blood and egg contents. Element concentrations and invertebrate composition differed strongly among habitats, and habitat use and element concentrations differed among shorebird species. Hg, Se, Cd, Cu, and Zn bioconcentrated from soil to invertebrates, and Hg, Se and Fe biomagnified from invertebrates to shorebird blood. As, Ni, Pb, Co and Mn showed significant biodilution from soil to invertebrates to shorebirds. Soil element levels were within Canadian guidelines, and invertebrate Hg levels were below dietary levels suggested for the protection of wildlife. However, maximum Hg in blood and eggs approached levels associated with toxicological effects and Hg-pollution in other bird species. Parental blood-Hg was negatively related to egg volume, although the relationship varied among species. No other elements approached established toxicological thresholds. In conclusion, whereas we found little evidence that exposure to elements at this site is leading to the declines of the species studied, Hg, as found elsewhere in the Canadian Arctic, is of potential

Analysis of ground water and soil samples from severely arsenic affected blocks of Murshidabad district

Directory of Open Access Journals (Sweden)

Manali Biswas

2017-10-01

Full Text Available Contamination of groundwater and soil by arsenic is a serious threat to existence of mankind on the globe. Arsenic contaminates soil and groundwater by natural biogeochemical cycles. However, due to anthropogenic activities like indiscriminant use of arsenic in disinfectants, weedicides, medicines and fertilizers, arsenic toxicity is a severe environmental issue, both at national and global level. U.S. Environmental Protection Agency and World Health Organization prescribed the permissible limit of arsenic in drinking water to be 10 µg/l. Exposure to arsenic at higher levels over a considerable period of time leads to skin lesions and cancer, disorders of cardiovascular, respiratory, gastrointestinal, hepatic and renal systems. Murshidabad is one of the severely arsenic affected districts of West Bengal. We have analyzed soil and groundwater samples from some of the highly arsenic affected blocks of Murshidabad district. Both the soil and groundwater samples have an alkaline pH, a characteristic of the presence of arsenic in the tested samples. Unfortunately, the socio-economic conditions of these villages force the residents to use groundwater as the source of drinking water. Presence of considerably high amount of total dissolved solids in water samples make them further unfit for consumption. High amount of phosphate and iron present in some of the water samples takes a toll on the detoxification and excretory system of the body, if those water samples are consumed on a regular manner. Contamination of soil by the aforesaid contaminants results in biomagnification of these pollutants in the food chain. We could also isolate certain potentially arsenic resistant bacteria from the contaminated soil and water samples. At the next level we have surveyed an arsenic affected village to analyze the clinical manifestation of arsenic poisoning. In this village subjects developed rampant skin lesions throughout the body due to exposure to arsenic

Bioaccumulation of tritiated water in phytoplankton and trophic transfer of organically bound tritium to the blue mussel, Mytilus edulis.

Science.gov (United States)

Jaeschke, Benedict C; Bradshaw, Clare

2013-01-01

Large releases of tritium are currently permitted in coastal areas due to assumptions that it rapidly disperses in the water and has a low toxicity due to its low energy emissions. This paper presents a laboratory experiment developed to identify previously untested scenarios where tritium may concentrate or transfer in biota relevant to Baltic coastal communities. Phytoplankton populations of Dunaliella tertiolecta and Nodularia spumigena were exposed at different growth-stages, to tritiated water (HTO; 10 MBq l(-1)). Tritiated D. tertiolecta was then fed to mussels, Mytilus edulis, regularly over a period of three weeks. Activity concentrations of phytoplankton and various tissues from the mussel were determined. Both phytoplankton species transformed HTO into organically-bound tritium (OBT) in their tissues. D. tertiolecta accumulated significantly more tritium when allowed to grow exponentially in HTO than if it had already reached the stationary growth phase; both treatments accumulated significantly more than the corresponding treatments of N. spumigena. No effect of growth phase on bioaccumulation of tritium was detectable in N. spumigena following exposure. After mussels were given 3 feeds of tritiated D. tertiolecta, significant levels of tritium were detected in the tissues. Incorporation into most mussel tissues appeared to follow a linear relationship with number of tritiated phytoplankton feeds with no equilibrium, highlighting the potential for biomagnification. Different rates of incorporation in species from a similar functional group highlight the difficulties in using a 'representative' species for modelling the transfer and impact of tritium. Accumulations of organic tritium into the mussel tissues from tritiated-phytoplankton demonstrate an environmentally relevant transfer pathway of tritium even when water-concentrations are reduced, adding weight to the assertion that organically bound tritium acts as a persistent organic pollutant. The

Modifiable risk factors for schizophrenia and autism--shared risk factors impacting on brain development.

Science.gov (United States)

Hamlyn, Jess; Duhig, Michael; McGrath, John; Scott, James

2013-05-01

Schizophrenia and autism are two poorly understood clinical syndromes that differ in age of onset and clinical profile. However, recent genetic and epidemiological research suggests that these two neurodevelopmental disorders share certain risk factors. The aims of this review are to describe modifiable risk factors that have been identified in both disorders, and, where available, collate salient systematic reviews and meta-analyses that have examined shared risk factors. Based on searches of Medline, Embase and PsycINFO, inspection of review articles and expert opinion, we first compiled a set of candidate modifiable risk factors associated with autism. Where available, we next collated systematic-reviews (with or without meta-analyses) related to modifiable risk factors associated with both autism and schizophrenia. We identified three modifiable risk factors that have been examined in systematic reviews for both autism and schizophrenia. Advanced paternal age was reported as a risk factor for schizophrenia in a single meta-analysis and as a risk factor in two meta-analyses for autism. With respect to pregnancy and birth complications, for autism one meta-analysis identified maternal diabetes and bleeding during pregnancy as risks factors for autism whilst a meta-analysis of eight studies identified obstetric complications as a risk factor for schizophrenia. Migrant status was identified as a risk factor for both autism and schizophrenia. Two separate meta-analyses were identified for each disorder. Despite distinct clinical phenotypes, the evidence suggests that at least some non-genetic risk factors are shared between these two syndromes. In particular, exposure to drugs, nutritional excesses or deficiencies and infectious agents lend themselves to public health interventions. Studies are now needed to quantify any increase in risk of either autism or schizophrenia that is associated with these modifiable environmental factors. Copyright © 2012 Elsevier Inc

Critical Success Factors for E-Learning Acceptance: Confirmatory Factor Models

Science.gov (United States)

Selim, Hassan M.

2007-01-01

E-learning, one of the tools emerged from information technology, has been integrated in many university programs. There are several factors that need to be considered while developing or implementing university curriculums that offer e-learning based courses. This paper is intended to specify e-learning critical success factors (CSFs) as…

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

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

Psychosocial job factors and biological cardiovascular risk factors in Mexican workers.

Science.gov (United States)

Garcia-Rojas, Isabel Judith; Choi, BongKyoo; Krause, Niklas

2015-03-01

Psychosocial job factors (PJF) have been implicated in the development of cardiovascular disease. The paucity of data from developing economies including Mexico hampers the development of worksite intervention efforts in those regions. This cross-sectional study of 2,330 Mexican workers assessed PJF (job strain [JS], social support [SS], and job insecurity [JI]) and biological cardiovascular disease risk factors [CVDRF] by questionnaire and on-site physical examinations. Alternative formulations of the JS scales were developed based on factor analysis and literature review. Associations between both traditional and alternative job factor scales with CVDRF were examined in multiple regression models, adjusting for physical workload, and socio-demographic factors. Alternative formulations of the job demand and control scales resulted in substantial changes in effect sizes or statistical significance when compared with the original scales. JS and JI showed hypothesized associations with most CVDRF, but they were inversely associated with diastolic blood pressure and some adiposity measures. SS was mainly protective against CVDRF. Among Mexican workers, alternative PJF scales predicted health outcomes better than traditional scales, and psychosocial stressors were associated with most CVDRF. © 2015 Wiley Periodicals, Inc.

Universality of soft and collinear factors in hard-scattering factorization

International Nuclear Information System (INIS)

Collins, John C.; Metz, Andreas

2004-01-01

Universality in QCD factorization of parton densities, fragmentation functions, and soft factors is endangered by the process dependence of the directions of Wilson lines in their definitions. We find a choice of directions that is consistent with factorization and that gives universality between e + e - annihilation, semi-inclusive deep-inelastic scattering, and the Drell-Yan process. Universality is only modified by a time-reversal transformation of the soft function and parton densities between Drell-Yan and the other processes, whose only effect is the known reversal of sign for T-odd parton densities such as the Sivers function. The modifications of the definitions needed to remove rapidity divergences with lightlike Wilson lines do not affect the results

Hemophilia as a defect of the tissue factor pathway of blood coagulation: Effect of factors VIII and IX on factor X activation in a continuous-flow reactor

International Nuclear Information System (INIS)

Repke, D.; Gemmell, C.H.; Guha, A.; Turitto, V.T.; Nemerson, Y.; Broze, G.J. Jr.

1990-01-01

The effect of factors VIII and IX on the ability of the tissue factor-factor VIIa complex to activate factor X was studied in a continuous-flow tubular enzyme reactor. Tissue factor immobilized in a phospholipid bilayer on the inner surface of the tube was exposed to a perfusate containing factors VIIa, VIII, IX, and X flowing at a wall shear rate of 57, 300, or 1130 sec -1 . The addition of factors VIII and IX at their respective plasma concentrations resulted in a further 2 endash-to 3 endash fold increase. The direct activation of factor X by tissue factor-factor VIIa could be virtually eliminated by the lipoprotein-associated coagulation inhibitor. These results suggest that the tissue factor pathway, mediated through factors VIII and IX, produces significant levels of factor Xa even in the presence of an inhibitor of the tissue factor-factor VIIa complex; moreover, the activation is dependent on local shear conditions. These findings are consistent both with a model of blood coagulation in which initiation of the system results from tissue factor and with the bleeding observed in hemophilia

Methylmercury in the Gulf of Trieste (Northern Adriatic Sea: From Microbial Sources to Seafood Consumers

Directory of Open Access Journals (Sweden)

Mark E. Hines

2014-01-01

Full Text Available The Gulf of Trieste (northern Adriatic Sea is one of the most mercury-polluted areas in the Mediterranean and in the world due to the past mining activity in the Idrija region (western Slovenia. The link between microbial production of toxic methylmercury (MeHg, and its bioaccumulation and biomagnification in marine food webs of the gulf is at present rather poorly characterized but is critical to understanding the links between sources and higher trophic levels, such as fish, that are ultimately vectors of human and wildlife exposure. This overview explores three major topics: (i the microbial biogeochemical cycling of Hg in the area, (ii the trophic transfer and bioaccumulation of MeHg in pelagic and benthic marine food webs, and (iii human exposure to Hg through marine fish and shellfish consumption. These are important goals since the Gulf of Trieste is an area of great economical importance.

Biocide by-products in aquatic environments. Annual report, October 1, 1977--September 30, 1978

International Nuclear Information System (INIS)

Anderson, D.R.; Bean, R.M.; Gibson, C.I.

1979-01-01

The Biocide By-Products in Aquatic Environments Program is composed of analytical chemistry and biological phases with freshwater and marine biological subdivisions. The objectives of the analytical studies are: to identify those chloroorganic chemical compounds that result from the addition of chlorine to fresh or saltwater; to develop methods for detecting chlorinated organics in the effluents discharged to receiving water bodies from nuclear stations; and to verify laboratory findings through analysis for chlorination by-products in water and biota samples from cooling water bodies of nuclear power stations. The objectives of the biological studies are: to investigate the immediate toxicity of specific chlorination by-products (chloroform in freshwater and bromoform in marine waters); to evaluate the chronic toxicity of chlorination by-products; to follow their pathways of action; and to analyze for bioaccumulation or biomagnification of halogenated hydrocarbons on selected aquatic or marine biota

Differential proteolytic activation of factor VIII-von Willebrand factor complex by thrombin

International Nuclear Information System (INIS)

Hill-Eubanks, D.C.; Parker, C.G.; Lollar, P.

1989-01-01

Blood coagulation factor VIII (fVIII) is a plasma protein that is decreased or absent in hemophilia A. It is isolated as a mixture of heterodimers that contain a variably sized heavy chain and a common light chain. Thrombin catalyzes the activation of fVIII in a reaction that is associated with cleavages in both types of chain. The authors isolated a serine protease from Bothrops jararacussu snake venom that catalyzes thrombin-like heavy-chain cleavage but not light-chain cleavage in porcine fVIII as judged by NaDodSO 4 /PAGE and N-terminal sequence analysis. Using a plasma-free assay of the ability of activated 125 I-fVIII to function as a cofactor in the activation of factor X by factor IXa, they found that fVIII is activated by the venom enzyme. The venom enzyme-activated fVIII was isolated in stable form by cation-exchange HPLC. von Willebrand factor inhibited venom enzyme-activated fVIII but not thrombin-activated fVIII. These results suggest that the binding of fVIII to von Willebrand factor depends on the presence of an intact light chain and that activated fVIII must dissociate from von Willebrand factor to exert its cofactor effect. Thus, proteolytic activation of fVIII-von Willebrand factor complex appears to be differentially regulated by light-chain cleavage to dissociate the complex and heavy-chain cleavage to activate the cofactor function

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.

Model of a ternary complex between activated factor VII, tissue factor and factor IX.

Science.gov (United States)

Chen, Shu-wen W; Pellequer, Jean-Luc; Schved, Jean-François; Giansily-Blaizot, Muriel

2002-07-01

Upon binding to tissue factor, FVIIa triggers coagulation by activating vitamin K-dependent zymogens, factor IX (FIX) and factor X (FX). To understand recognition mechanisms in the initiation step of the coagulation cascade, we present a three-dimensional model of the ternary complex between FVIIa:TF:FIX. This model was built using a full-space search algorithm in combination with computational graphics. With the known crystallographic complex FVIIa:TF kept fixed, the FIX docking was performed first with FIX Gla-EGF1 domains, followed by the FIX protease/EGF2 domains. Because the FIXa crystal structure lacks electron density for the Gla domain, we constructed a chimeric FIX molecule that contains the Gla-EGF1 domains of FVIIa and the EGF2-protease domains of FIXa. The FVIIa:TF:FIX complex has been extensively challenged against experimental data including site-directed mutagenesis, inhibitory peptide data, haemophilia B database mutations, inhibitor antibodies and a novel exosite binding inhibitor peptide. This FVIIa:TF:FIX complex provides a powerful tool to study the regulation of FVIIa production and presents new avenues for developing therapeutic inhibitory compounds of FVIIa:TF:substrate complex.

Robust and Sparse Factor Modelling

DEFF Research Database (Denmark)

Croux, Christophe; Exterkate, Peter

Factor construction methods are widely used to summarize a large panel of variables by means of a relatively small number of representative factors. We propose a novel factor construction procedure that enjoys the properties of robustness to outliers and of sparsity; that is, having relatively few...... 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...

Risk factors for stress fractures.

Science.gov (United States)

Bennell, K; Matheson, G; Meeuwisse, W; Brukner, P

1999-08-01

Preventing stress fractures requires knowledge of the risk factors that predispose to this injury. The aetiology of stress fractures is multifactorial, but methodological limitations and expediency often lead to research study designs that evaluate individual risk factors. Intrinsic risk factors include mechanical factors such as bone density, skeletal alignment and body size and composition, physiological factors such as bone turnover rate, flexibility, and muscular strength and endurance, as well as hormonal and nutritional factors. Extrinsic risk factors include mechanical factors such as surface, footwear and external loading as well as physical training parameters. Psychological traits may also play a role in increasing stress fracture risk. Equally important to these types of analyses of individual risk factors is the integration of information to produce a composite picture of risk. The purpose of this paper is to critically appraise the existing literature by evaluating study design and quality, in order to provide a current synopsis of the known scientific information related to stress fracture risk factors. The literature is not fully complete with well conducted studies on this topic, but a great deal of information has accumulated over the past 20 years. Although stress fractures result from repeated loading, the exact contribution of training factors (volume, intensity, surface) has not been clearly established. From what we do know, menstrual disturbances, caloric restriction, lower bone density, muscle weakness and leg length differences are risk factors for stress fracture. Other time-honoured risk factors such as lower extremity alignment have not been shown to be causative even though anecdotal evidence indicates they are likely to play an important role in stress fracture pathogenesis.

Threshold factorization redux

Science.gov (United States)

Chay, Junegone; Kim, Chul

2018-05-01

We reanalyze the factorization theorems for the Drell-Yan process and for deep inelastic scattering near threshold, as constructed in the framework of the soft-collinear effective theory (SCET), from a new, consistent perspective. In order to formulate the factorization near threshold in SCET, we should include an additional degree of freedom with small energy, collinear to the beam direction. The corresponding collinear-soft mode is included to describe the parton distribution function (PDF) near threshold. The soft function is modified by subtracting the contribution of the collinear-soft modes in order to avoid double counting on the overlap region. As a result, the proper soft function becomes infrared finite, and all the factorized parts are free of rapidity divergence. Furthermore, the separation of the relevant scales in each factorized part becomes manifest. We apply the same idea to the dihadron production in e+e- annihilation near threshold, and show that the resultant soft function is also free of infrared and rapidity divergences.

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.

Factores pronósticos del cáncer de mama Prognostic factors of breast cancer

Directory of Open Access Journals (Sweden)

José María González Ortega

2011-03-01

Full Text Available Los factores pronósticos se deben diferenciar de los factores predictivos. Un factor pronóstico es cualquier medición utilizable en el momento de la cirugía que correlaciona con el intervalo libre de enfermedad o supervivencia global en ausencia de tratamiento adyuvante sistémico y como resultado es capaz de correlacionar con la historia natural de la enfermedad. En contraste, un factor predictivo es cualquier medición asociada con respuesta a un tratamiento dado. Entre los factores pronósticos del cáncer de mama existen factores clínicos, histológicos, biológicos, genéticos y psicosociales. En esta revisión de los factores pronósticos psicosociales ha quedado demostrado que el estrés y la depresión son factores pronósticos negativos en las pacientes con cáncer de mama. Se debe recordar que la evaluación de un solo parámetro pronóstico ayuda, pero no es útil para la gestión clínica y terapéutica de la paciente.The prognostic factors must to be differentiated of the predictive ones. A prognostic factor is any measurement used at moment of the surgery correlated with the free interval of disease or global survival in the absence of the systemic adjuvant treatment and as result is able to correlate with the natural history of the disease. In contrast, a predictive factor is any measurement associated with the response to a given treatment. Among the prognostic factors of the breast cancer are included the clinical, histological, biological, genetic and psychosocial factors. In present review of psychosocial prognostic factors has been demonstrated that the stress and the depression are negative prognostic factors in patients presenting with breast cancer. It is essential to remember that the assessment of just one prognostic parameter is a help but it is not useful to clinical and therapeutic management of the patient.

Critical human-factors issues in nuclear-power regulation and a recommended comprehensive human-factors long-range plan. Critical discussion of human factors areas of concern

International Nuclear Information System (INIS)

Hopkins, C.O.; Snyder, H.L.; Price, H.E.; Hornick, R.J.; Mackie, R.R.; Smillie, R.J.; Sugarman, R.C.

1982-08-01

This comprehensive long-range human factors plan for nuclear reactor regulation was developed by a Study Group of the Human Factors Society, Inc. This Study Group was selected by the Executive Council of the Society to provide a balanced, experienced human factors perspective to the applications of human factors scientific and engineering knowledge to nuclear power generation. The report is presented in three volumes. Volume 1 contains an Executive Summary of the 18-month effort and its conclusions. Volume 2 summarizes all known nuclear-related human factors activities, evaluates these activities wherever adequate information is available, and describes the recommended long-range (10-year) plan for human factors in regulation. Volume 3 elaborates upon each of the human factors issues and areas of recommended human factors involvement contained in the plan, and discusses the logic that led to the recommendations

Factoring SözleşmesiFactoring Contracts

OpenAIRE

DEMİR,  REMZİ

2013-01-01

man tekniğidir. Bir başka ifadeyle, factoring, firmaların satışlarından doğan vadeli alacaklarını factore peşin bedel ile satmaları işlemidir4. Hukuki anlamda mal satımı ve/veya hizmet arzı ile uğraşan firma- ların bu satışları sonucu doğan veya doğacak alacaklarını devralarak tahsilini üstlenen, bu alacaklara karşı peşin ödemelerde bulunarak finansman sağlayan, aynı anda firmalara idari, ticari ve mali konu- larda verilen hizmetler karşılığı faiz, komisyon ve ücrete hak kaza- nan kişi ve...

Testing alternative factor models of PTSD and the robustness of the dysphoria factor.

Science.gov (United States)

Elklit, Ask; Armour, Cherie; Shevlin, Mark

2010-01-01

This study first aimed to examine the structure of self-reported posttraumatic stress disorder (PTSD) symptoms using three different samples. The second aim of the paper was to test the robustness of the factor analytic model when depression scores were controlled for. Based on previous factor analytic findings and the DSM-IV formulation, six confirmatory factor models were specified and estimated that reflected different symptom clusters. The best fitting model was subsequently re-fitted to the data after including a depression variable. The analyses were based on responses from 973 participants across three samples. Sample 1 consisted of 633 parents who were members of 'The National Association of Infant Death' and who had lost a child. Sample 2 consisted of 227 victims of rape, who completed a questionnaire within 4 weeks of the rape. Each respondent had been in contact with the Centre for Rape Victims (CRV) at the Aarhus University Hospital, Denmark. Sample 3 consisted of 113 refugees resident in Denmark. All participants had been referred to a treatment centre which focused on rehabilitating refugees through treatment for psychosocial integration problems (RRCF: Rehabliterings og Revliderings Centre for Flygtninge). In total 500 participants received a diagnosis of PTSD/sub-clinical PTSD (Sample 1, N=214; 2, N=176; 3, N=110). A correlated four-factor model with re-experiencing, avoidance, dysphoria, and arousal factors provided the best fit to the sample data. The average attenuation in the factor loadings was highest for the dysphoria factor (M=-.26, SD=.11) compared to the re-experiencing (M=-.14, SD=.18), avoidance (M=-.10, SD=.21), and arousal (M=-.09, SD=.13) factors. With regards to the best fitting factor model these results concur with previous research findings using different trauma populations but do not reflect the current DSM-IV symptom groupings. The attenuation of dysphoria factor loadings suggests that dysphoria is a non-specific component of

Security Gaps In Authentication Factor Credentials

Directory of Open Access Journals (Sweden)

Neeraj A. Sharma

2015-08-01

Full Text Available Authentication factors refer to user login credentials that a user supplies to an authentication process for it to decide whether to grant or deny access. While two-factor and three-factor authentication generally provides better security than one-factor authentication the aim of this paper is to review security in individual authentication factor credentials that are in use nowadays. These credentials will be discussed in factor categories knowledge factor possession factor and inherence factor. The paper details current security gaps and some novel approaches to diminish the gaps in these authentication factors. We believe that our recommendations will inspire development of better authentication credentials and systems.

MANAGEMENT SOFT-FACTORS IN INDUSTRIES

Directory of Open Access Journals (Sweden)

L. V. Fatkin

2012-01-01

Full Text Available No proper attention is given in existing management theories and concepts to systematization and analysis of non-material management factors, so-called «soft-factors». In industries, management soft-factors may be treated in a broader way. An example of a broader treatment of management soft-factors is given for the system of state regulation of foreign trade activities in industries along with specification, determination and rating of organizational and administrative management soft-factors.

[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

Rare coagulation disorders: fibrinogen, factor VII and factor XIII.

Science.gov (United States)

de Moerloose, P; Schved, J-F; Nugent, D

2016-07-01

Rare coagulation disorders (RCDs) include the inherited deficiencies of fibrinogen, factor (F) II, FV, combined FV and VIII, FVII, FX, combined FVII and X, FXI, FXIII and combined congenital deficiency of vitamin K-dependent factors (VKCFDs). Despite their rarity, a deep comprehension of all these disorders is essential to really understand haemostasis. Indeed, even if they share some common features each RCD has some particularity which makes it unique. In this review, we focus on three disorders: fibrinogen, FVII and FXIII. © 2016 John Wiley & Sons Ltd.

Stress Concentration Factor and Stress Intensity Factor with U-notch and Crack in the Beam

Energy Technology Data Exchange (ETDEWEB)

Seo, Bo Seong; Lee, Kwang Ho [Kyungpook National Univ., Daegu (Korea, Republic of)

2016-05-15

The stress concentration factors and stress intensity factors for a simple beam and a cantilever are analyzed by using finite element method and photoelasticity. Using the analyzed results, the estimated graphs on stress concentration factors and stress intensity factors are obtained. To analyze stress concentration factors of notch, the dimensionless notch length H(height of specimen)/h=1.1-2 and dimensionless gap space r(radius at the notch tip)/h=0.1~0.5 are used, where h=H-c and c is the notch length. As the notch gap length increases and the gap decreases, the stress concentration factors increase. Stress concentration factors of a simple beam are greater than those of a cantilever beam. However, actually, the maximum stress values under a load, a notch length and a gap occur more greatly in the cantilever beam than in the simple beam. To analyze stress intensity factors, the normalized crack length α(crack length)/H=0.2~0.5 is used. As the length of the crack increases, the normalized stress intensity factors increase. The stress intensity factors under a constant load and a crack length occur more greatly in the cantilever beam than in the simple beam.

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....

Disconnected electromagnetic form factors

International Nuclear Information System (INIS)

Wilcox, Walter

2001-01-01

Preliminary results of a calculation of disconnected nucleon electromagnetic factors factors on the lattice are presented. The implementation of the numerical subtraction scheme is outlined. A comparison of results for electric and magnetic disconnected form factors on two lattice sizes with those of the Kentucky group is presented. Unlike previous results, the results found in this calculation are consistent with zero in these sectors

Prognostic factors of breast cancer

International Nuclear Information System (INIS)

Gonzalez Ortega, Jose Maria; Morales Wong, Mario Miguel; Lopez Cuevas, Zoraida; Diaz Valdez, Marilin

2011-01-01

The prognostic factors must to be differentiated of the predictive ones. A prognostic factor is any measurement used at moment of the surgery correlated with the free interval of disease or global survival in the absence of the systemic adjuvant treatment and as result is able to correlate with the natural history of the disease. In contrast, a predictive factor is any measurement associated with the response to a given treatment. Among the prognostic factors of the breast cancer are included the clinical, histological, biological, genetic and psychosocial factors. In present review of psychosocial prognostic factors has been demonstrated that the stress and the depression are negative prognostic factors in patients presenting with breast cancer. It is essential to remember that the assessment of just one prognostic parameter is a help but it is not useful to clinical and therapeutic management of the patient.(author)

Soil Forming Factors

Science.gov (United States)

It! What is Soil? Chip Off the Old Block Soil Forming Factors Matters of Life and Death Underneath It All Wise Choices A World of Soils Soil Forming Factors 2 A Top to Bottom Guide 3 Making a Soil Monolith 4 Soil Orders 5 State Soil Monoliths 6 Where in the Soil World Are You? >> A Top to

Exposure Factors Resources: Contrasting EPA’s Exposure Factors Handbook with International Sources (Journal Article)

Science.gov (United States)

Efforts to compile and standardize exposure human factors have resulted in the development of a variety of resources available to the scientific community. For example, the U.S. EPA developed the Exposure Factors Handbook and Child-specific Exposure Factors Handbook to promote c...

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

Factors Affecting Medical Service Quality.

Science.gov (United States)

Mosadeghrad, Ali Mohammad

2014-02-01

A better understanding of factors influencing quality of medical service can pinpoint better strategies for quality assurance in medical services. This study aimed to identify factors affecting the quality of medical services provided by Iranian physicians. Exploratory in-depth individual interviews were conducted with sixty-four physicians working in various medical institutions in Iran. Individual, organizational and environmental factors enhance or inhibit the quality of medical services. Quality of medical services depends on the personal factors of the physician and patient, and factors pertaining to the healthcare setting and the broader environment. Differences in internal and external factors such as availability of resources, patient cooperation and collaboration among providers affect the quality of medical services and patient outcomes. Supportive leadership, proper planning, education and training and effective management of resources and processes improve the quality of medical services. This article contributes to healthcare theory and practice by developing a conceptual framework for understanding factors that influence medical services quality.

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.)

Factors predicting outcome in whiplash injury: a systematic meta-review of prognostic factors.

Science.gov (United States)

Sarrami, Pooria; Armstrong, Elizabeth; Naylor, Justine M; Harris, Ian A

2017-03-01

Whiplash injuries are among the leading injuries related to car crashes and it is important to determine the prognostic factors that predict the outcome of patients with these injuries. This meta-review aims to identify factors that are associated with outcome after acute whiplash injury. A systematic search for all systematic reviews on outcome prediction of acute whiplash injury was conducted across several electronic databases. The search was limited to publications in English, and there were no geographical or time of publication restrictions. Quality appraisal was conducted with A Measurement Tool to Assess Systematic Reviews. The initial search yielded 207 abstracts; of these, 195 were subsequently excluded by topic or method. Twelve systematic reviews with moderate quality were subsequently included in the analysis. Post-injury pain and disability, whiplash grades, cold hyperalgesia, post-injury anxiety, catastrophizing, compensation and legal factors, and early healthcare use were associated with continuation of pain and disability in patients with whiplash injury. Post-injury magnetic resonance imaging or radiographic findings, motor dysfunctions, or factors related to the collision were not associated with continuation of pain and disability in patients with whiplash injury. Evidence on demographic and three psychological factors and prior pain was conflicting, and there is a shortage of evidence related to the significance of genetic factors. This meta-review suggests an association between initial pain and anxiety and the outcome of acute whiplash injury, and less evidence for an association with physical factors. Level 1.

Depressive Symptoms in Chinese Elementary School Children: Child Social-Cognitive Factors and Parenting Factors

Science.gov (United States)

Chan, Siu Mui; Oi Poon, Scarlet Fung

2016-01-01

This study examined child cognitive-behavioural factors and parenting factors related to childhood depressive symptoms. Results indicate that positive and negative attributional styles were protective and vulnerable factors of depression symptoms, respectively, and the attribution-depression link was mediated by self-esteem and coping responses.…

Dental Students' Perceptions of Risk Factors for Musculoskeletal Disorders: Adapting the Job Factors Questionnaire for Dentistry.

Science.gov (United States)

Presoto, Cristina D; Wajngarten, Danielle; Domingos, Patrícia A S; Campos, Juliana A D B; Garcia, Patrícia P N S

2018-01-01

The aims of this study were to adapt the Job Factors Questionnaire to the field of dentistry, evaluate its psychometric properties, evaluate dental students' perceptions of work/study risk factors for musculoskeletal disorders, and determine the influence of gender and academic level on those perceptions. All 580 students enrolled in two Brazilian dental schools in 2015 were invited to participate in the study. A three-factor structure (Repetitiveness, Work Posture, and External Factors) was tested through confirmatory factor analysis. Convergent validity was estimated using the average variance extracted (AVE), discriminant validity was based on the correlational analysis of the factors, and reliability was assessed. A causal model was created using structural equation modeling to evaluate the influence of gender and academic level on students' perceptions. A total of 480 students completed the questionnaire for an 83% response rate. The responding students' average age was 21.6 years (SD=2.98), and 74.8% were women. Higher scores were observed on the Work Posture factor items. The refined model presented proper fit to the studied sample. Convergent validity was compromised only for External Factors (AVE=0.47), and discriminant validity was compromised for Work Posture and External Factors (r 2 =0.69). Reliability was adequate. Academic level did not have a significant impact on the factors, but the women students exhibited greater perception. Overall, the adaptation resulted in a useful instrument for assessing perceptions of risk factors for musculoskeletal disorders. Gender was found to significantly influence all three factors, with women showing greater perception of the risk factors.

Aspects of QCD factorization

International Nuclear Information System (INIS)

Neubert, Matthias

2001-01-01

The QCD factorization approach provides the theoretical basis for a systematic analysis of nonleptonic decay amplitudes of B mesons in the heavy-quark limit. After recalling the basic ideas underlying this formalism, several tests of QCD factorization in the decays B→D (*) L, B→K * γ, and B→πK, ππ are discussed. It is then illustrated how factorization can be used to obtain new constraints on the parameters of the unitarity triangle

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.

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

Human factors guides

Energy Technology Data Exchange (ETDEWEB)

Penington, J [PHF Services Inc., (Canada)

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.

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....... To validate re-citations as caused by specialisation, other possible causes were measured and correlated (obsolescence, journal self-citations and number of references). Results. The results indicate that the focus factor is capable of distinguishing between general and specialised journals and thus...... effectively measures the intended phenomenon (i.e., journal specialisation). Only weak correlations were found between journal re-citations and obsolescence, journal self-citations, and number of references. Conclusions. The focus factor successfully measures journal specialisation over time. Measures based...

Examination of contaminant exposure and reproduction of ospreys (Pandion haliaetus) nesting in Delaware Bay and River in 2015.

Science.gov (United States)

Rattner, Barnett A; Lazarus, Rebecca S; Bean, Thomas G; McGowan, Peter C; Callahan, Carl R; Erickson, Richard A; Hale, Robert C

2018-05-22

A study of ospreys (Pandion haliaetus) nesting in the coastal Inland Bays of Delaware, and the Delaware Bay and Delaware River in 2015 examined spatial and temporal trends in contaminant exposure, food web transfer and reproduction. Concentrations of organochlorine pesticides and metabolites, polychlorinated biphenyls (PCBs), coplanar PCB toxic equivalents, polybrominated diphenyl ethers (PBDEs) and other flame retardants in sample eggs were generally greatest in the Delaware River. Concentrations of legacy contaminants in 2015 Delaware Bay eggs were lower than values observed in the 1970s through early 2000s. Several alternative brominated flame retardants were rarely detected, with only TBPH [bis(2-ethylhexyl)-tetrabromophthalate)] present in 5 of 27 samples at <5 ng/g wet weight. No relation was found between p,p'-DDE, total PCBs or total PBDEs in eggs with egg hatching, eggs lost from nests, nestling loss, fledging and nest success. Osprey eggshell thickness recovered to pre-DDT era values, and productivity was adequate to sustain a stable population. Prey fish contaminant concentrations were generally less than those in osprey eggs, with detection frequencies and concentrations greatest in white perch (Morone americana) from Delaware River compared to the Bay. Biomagnification factors from fish to eggs for p,p'-DDE and total PCBs were generally similar to findings from several Chesapeake Bay tributaries. Overall, findings suggest that there have been improvements in Delaware Estuary waterbird habitat compared to the second half of the 20th century. This trend is in part associated with mitigation of some anthropogenic contaminant threats. Copyright © 2018 Elsevier B.V. All rights reserved.

Condensation in models with factorized and pair-factorized stationary states

International Nuclear Information System (INIS)

Evans, M R; Waclaw, B

2015-01-01

Non-equilibrium real-space condensation is a phenomenon in which a finite fraction of some conserved quantity (mass, particles, etc) becomes spatially localized. We review two popular stochastic models of hopping particles that lead to condensation and whose stationary states assume a factorized form: the zero-range process and the misanthrope process, and their various generalizations. We also introduce a new model—a misanthrope process with parallel dynamics—that exhibits condensation and has a pair-factorized stationary state

BASIC FACTORS OF MARKET CONCENTRATION

OpenAIRE

V. Fyliuk

2013-01-01

The paper systemizes factors which reinforce trends towards market concentration in all economic systems. These factors include factors related to the general changes in economic environment such as globalization of the world economy, state structural and taxation policies, cycle of economic development and changes in consumer demand. They also include factors related to competition (intensification of competition, companies’ desire to monopolize market and present market structure) and scien...

Adipose stem cells from chronic pancreatitis patients improve mouse and human islet survival and function.

Science.gov (United States)

Song, Lili; Sun, Zhen; Kim, Do-Sung; Gou, Wenyu; Strange, Charlie; Dong, Huansheng; Cui, Wanxing; Gilkeson, Gary; Morgan, Katherine A; Adams, David B; Wang, Hongjun

2017-08-30

Chronic pancreatitis has surgical options including total pancreatectomy to control pain. To avoid surgical diabetes, the explanted pancreas can have islets harvested and transplanted. Immediately following total pancreatectomy with islet autotransplantation (TP-IAT), many islet cells die due to isolation and transplantation stresses. The percentage of patients remaining insulin free after TP-IAT is therefore low. We determined whether cotransplantation of adipose-derived mesenchymal stem cells (ASCs) from chronic pancreatitis patients (CP-ASCs) would protect islets after transplantation. In a marginal mass islet transplantation model, islets from C57BL/6 mice were cotransplanted with CP-ASCs into syngeneic streptozotocin-treated diabetic mice. Treatment response was defined by the percentage of recipients reaching normoglycemia, and by the area under the curve for glucose and c-peptide in a glucose tolerance test. Macrophage infiltration, β-cell apoptosis, and islet graft vasculature were measured in transplanted islet grafts by immunohistochemistry. mRNA expression profiling of 84 apoptosis-related genes in islet grafts transplanted alone or with CP-ASCs was measured by the RT 2 Profiler™ Apoptosis PCR Array. The impact of insulin-like growth factor-1 (IGF-1) on islet apoptosis was determined in islets stimulated with cytokines (IL-1β and IFN-γ) in the presence and absence of CP-ASC conditioned medium. CP-ASC-treated mice were more often normoglycemic compared to mice receiving islets alone. ASC cotransplantation reduced macrophage infiltration, β-cell death, suppressed expression of TNF-α and Bcl-2 modifying factor (BMF), and upregulated expressions of IGF-1 and TNF Receptor Superfamily Member 11b (TNFRSF11B) in islet grafts. Islets cultured in conditioned medium from CP-ASCs showed reduced cell death. This protective effect was diminished when IGF-1 was blocked in the conditioned medium by the anti-IGF-1 antibody. Cotransplantation of islets with ASCs

Electromagnetic form factors of hadrons

International Nuclear Information System (INIS)

Zidell, V.S.

1976-01-01

A vector meson dominance model of the electromagnetic form factors of hadrons is developed which is based on the use of unstable particle propagators. Least-square fits are made to the proton, neutron, pion and kaon form factor data in both the space and time-like regions. A good fit to the low-energy nucleon form factor data is obtained using only rho, ω, and phi dominance, and leads to a determination of the vector meson resonance parameters in good agreement with experiment. The nucleon-vector meson coupling constants obey simple sum rules indicating that there exists no hard core contribution to the form factors within theoretical uncertainties. The prediction for the electromagnetic radii of the proton is in reasonable agreement with recent experiments. The pion and kaon charge form factors as deduced from the nucleon form factors assuming vector meson universality are compared to the data. The pion form factor agrees with the data in both the space and time-like regions. The pion charge radius is in agreement with the recent Dubna result, but the isovector P-wave pion-pion phase shift calculated from the theory disagrees with experiment. A possible contribution to the form factors from a heavy rho meson is also evaluated

Cognitive style as a factor in accounting students' perceptions of career-choice factors.

Science.gov (United States)

Gul, F; Huang, A; Subramaniam, N

1992-12-01

Since prior studies of individuals' perceptions of career-choice factors have not considered the effect of cognitive styles of subjects, this study, using 68 accounting students, investigated the mediating effects of the field dependent-independent cognitive dimension on perceptions of the importance of career-choice factors. The results, in general, show that cognitive style affected individuals' perceptions of career-choice factors, suggesting that future studies of individuals' perceptions should take into account individual cognitive differences.

Factors Influencing of Social Conflict

Directory of Open Access Journals (Sweden)

Suwandi Sumartias

2013-07-01

Full Text Available Social conflicts that occur in several areas in Indonesia lately, one of them is caused by the weakness of law certainty. This is feared to threaten the integration of the Republic of Indonesia. This study aims to determine the factors that affect social conflict in Manis Lor village in Kuningan district. The method used the explanatory quantitative methods, the statistical test Path Analysis. The study population was a formal and informal community leaders (village chief, clergy, and youth, and the people who involved in a conflict in Manis Lor village Kuningan regency. The result shows a There is no significant influence between social identity factors with social conflict anarchist. b There is significant influence between socio-economic factors with social conflict anarchists. c There is no significant influence between the credibility factor anarchist leaders with social conflict. d There is no significant influence between the motive factor with anarchist social conflict. e There is significant influence between personality factors/beliefs with anarchist social conflict. f There is significant influence of behavioral factors anarchist communication with social conflict.

[Predictive factors of anxiety disorders].

Science.gov (United States)

Domschke, K

2014-10-01

Anxiety disorders are among the most frequent mental disorders in Europe (12-month prevalence 14%) and impose a high socioeconomic burden. The pathogenesis of anxiety disorders is complex with an interaction of biological, environmental and psychosocial factors contributing to the overall disease risk (diathesis-stress model). In this article, risk factors for anxiety disorders will be presented on several levels, e.g. genetic factors, environmental factors, gene-environment interactions, epigenetic mechanisms, neuronal networks ("brain fear circuit"), psychophysiological factors (e.g. startle response and CO2 sensitivity) and dimensional/subclinical phenotypes of anxiety (e.g. anxiety sensitivity and behavioral inhibition), and critically discussed regarding their potential predictive value. The identification of factors predictive of anxiety disorders will possibly allow for effective preventive measures or early treatment interventions, respectively, and reduce the individual patient's suffering as well as the overall socioeconomic burden of anxiety disorders.

An inter-battery factor analysis of the comrey personality scales and the 16 personality factor questionnaire

OpenAIRE

Gideon P. de Bruin

2000-01-01

The scores of 700 Afrikaans-speaking university students on the Comrey Personality Scales and the 16 Personality Factor Questionnaire were subjected to an inter-battery factor analysis. This technique uses only the correlations between two sets of variables and reveals only the factors that they have in common. Three of the Big Five personality factors were revealed, namely Extroversion, Neuroticism and Conscientiousness. However, the Conscientiousness factor contained a relatively strong uns...

Transforming growth factor alpha and epidermal growth factor in laryngeal carcinomas demonstrated by immunohistochemistry

DEFF Research Database (Denmark)

Christensen, M E; Therkildsen, M H; Poulsen, Steen Seier

1993-01-01

the basal cell layer. The present investigation and our previous results confirm the existence of EGF receptors, TGF-alpha and EGF in laryngeal carcinomas. In addition, we conclude that the conditions do exist for growth factors to act through an autocrine system in poorly differentiated tumours and through......Fifteen laryngeal squamous cell carcinomas were investigated for the presence of transforming growth factor alpha (TGF-alpha) and epidermal growth factor (EGF) using immunohistochemical methods. In a recent study the same material was characterized for epidermal growth factor receptors (EGF...... receptors) which were confined predominantly to the undifferentiated cells. The expression of this growth factor system in malignant cells may play a role in carcinogenesis and/or tumour growth. All carcinomas were positive for TGF-alpha and 12 were positive for EGF. In moderately-to-well differentiated...

A Beginner’s Guide to Factor Analysis: Focusing on Exploratory Factor Analysis

Directory of Open Access Journals (Sweden)

An Gie Yong

2013-10-01

Full Text Available The following paper discusses exploratory factor analysis and gives an overview of the statistical technique and how it is used in various research designs and applications. A basic outline of how the technique works and its criteria, including its main assumptions are discussed as well as when it should be used. Mathematical theories are explored to enlighten students on how exploratory factor analysis works, an example of how to run an exploratory factor analysis on SPSS is given, and finally a section on how to write up the results is provided. This will allow readers to develop a better understanding of when to employ factor analysis and how to interpret the tables and graphs in the output.

Radioimmunoassay of human Hageman factor (factor XII)

International Nuclear Information System (INIS)

Saito, H.; Ratnoff, O.D.; Pensky, J.

1976-01-01

A specific, sensitive, and reproducible radioimmunoassay for human Hageman factor (HF, factor XII) has been developed with purified human HF and monospecific rabbit antibody. Precise measurements of HF antigen were possible for concentrations as low as 0.1 percent of that in normal pooled plasma. A good correlation (correlation coefficient = 0.82) existed between the titers of HF measured by clot-promoting assays and radioimmunoassays among 42 normal adults. Confirming earlier studies, HF antigen was absent in Hageman trait plasma, but other congenital deficient plasmas, including those of individuals with Fletcher trait and Fitzgerald trait, contained normal amounts of HF antigen. HF antigen was reduced in the plasmas of patients with disseminated intravascular coagulation or advanced liver cirrhosis, but it was normal in those of patients with chronic renal failure or patients under treatment with warfarin. HF antigen was detected by this assay in plasmas of primates, but not detectable in plasmas of 11 nonprimate mammalian and one avian species

New microbial growth factor

Science.gov (United States)

Bok, S. H.; Casida, L. E., Jr.

1977-01-01

A screening procedure was used to isolate from soil a Penicillium sp., two bacterial isolates, and a Streptomyces sp. that produced a previously unknown microbial growth factor. This factor was an absolute growth requirement for three soil bacteria. The Penicillium sp. and one of the bacteria requiring the factor, an Arthrobacter sp., were selected for more extensive study concerning the production and characteristics of the growth factor. It did not seem to be related to the siderochromes. It was not present in soil extract, rumen fluid, or any other medium component tested. It appears to be a glycoprotein of high molecular weight and has high specific activity. When added to the diets for a meadow-vole mammalian test system, it caused an increased consumption of diet without a concurrent increase in rate of weight gain.

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

Risk Factor Assessment Branch (RFAB)

Science.gov (United States)

The Risk Factor Assessment Branch (RFAB) focuses on the development, evaluation, and dissemination of high-quality risk factor metrics, methods, tools, technologies, and resources for use across the cancer research continuum, and the assessment of cancer-related risk factors in the population.

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.

Systems competing for mobile factors: decision making based on hard vs. soft locational factors

Directory of Open Access Journals (Sweden)

Clodnițchi Roxana

2017-12-01

Full Text Available The paper explores the links between capital relocation and soft locational factors addressing the quality of the business environment and the quality of life within the European Union. System competition is viewed as a competition between countries for the mobile factors capital and labour. The issue of systems competition is topical and insufficiently explored by contemporary literature. The scarcity of scientific papers describing the links between system competition theories and contemporary corporate geography theories, especially of the ones including the analysis of soft location factors, is a challenging aspect, which motivates the choice of this subject. This paper’s primary aim is to deliver an overview of the basic corporate geography conceptions, stressing the importance of soft location factors in today’s competition between systems for the mobile factors capital and labour. The paper further contains an analysis of the correlations between indicators regarding the institutional design of countries as developed by the World Bank (Ease of Doing Business, the Happiness Scale and the latest available data of FDI Stocks for the EU countries (2016. The relevance of such a study is based on the evidence that the contemporary business education relies on an extensive knowledge of the business environment. In the circumstance of similar infrastructural conditions, the main difference between locations is made by soft location factors. Since developed economies are characterised by a high degree of ubiquity of soft factors, the paper concludes that developing and emerging economies should foster the development of their soft location factors.

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...

FACET, Radiation View Factor with Shadowing

International Nuclear Information System (INIS)

Shapiro, A.B.

1988-01-01

1 - Description of program or function: FACET calculates the radiation geometric view factor (alternatively called shape factor, angle factor, or configuration factor) between surfaces for axisymmetric, two-dimensional planar and three-dimensional geometries with interposed third surface obstructions. FACET was developed to calculate view factors as input data to finite element heat transfer analysis codes. 2 - Method of solution: Three algorithms are incorporated to integrate the view factor equation for three dimensional geometries. The algorithm used for any two surfaces depends on their geometric relationship and whether third surface obstructions exist. The three algorithms are the area integration (AI) method, the line integration method (LI), and the Mitalas and Stephenson (MS) method. The LI method is used to calculate the view factor between two disjoint surfaces. If the two surfaces have an adjoint edge, the MS method is used. The AI method is used if there is self or third surface shadowing. In two-dimensional planar geometries, the view factor between two surfaces is calculated using Hottel's cross string method. For axisymmetric geometries in the absence of shadowing, the view factor between two surfaces is calculated by view factor algebra using the view factors between parallel coaxial discs. In the presence of self or third surface shadowing, the geometry is represented in three dimensions before calculating the view factors

Replacing fish meal by food waste in feed pellets to culture lower trophic level fish containing acceptable levels of organochlorine pesticides: health risk assessments.

Science.gov (United States)

Cheng, Zhang; Mo, Wing-Yin; Man, Yu-Bon; Nie, Xiang-Ping; Li, Kai-Bing; Wong, Ming-Hung

2014-12-01

The present study used food waste (collected from local hotels and restaurants) feed pellets in polyculture of low-trophic level fish [bighead (Aristichtys nobilis), grass carp (Ctenopharyngodon idellus), and mud carp (Cirrhina molitorella)] aiming at producing safe and quality products for local consumption. The results indicated that grass carp (hexachlorocyclohexanes (HCHs) waste feed pellets were relatively free of organochlorine pesticides (OCPs). The experimental ponds (water and sediment) were relatively free of OCPs, lowering the possibility of biomagnification of OCPs in the food chains within the ponds. The raw concentrations of OCPs extracted from the fish were not in the bioavailable form, which would ultimately reach bloodstream and exert adverse effects on human body. Health risk assessments based on digestible concentrations are commonly regarded as a more accurate method. The results of health risk assessments based on raw and digestible concentrations showed that the fish fed with food waste feed pellets were safe for consumption from the OCP perspective. Copyright © 2014 Elsevier Ltd. All rights reserved.

Tributyltin and Zebrafish: Swimming in Dangerous Water

Directory of Open Access Journals (Sweden)

Clemilson Berto-Júnior

2018-04-01

Full Text Available Zebrafish has been established as a reliable biological model with important insertion in academy (morphologic, biochemical, and pathophysiological studies and pharmaceutical industry (toxicology and drug development due to its molecular complexity and similar systems biology that recapitulate those from other organisms. Considering the toxicological aspects, many efforts using zebrafish models are being done in order to elucidate the effects of endocrine disruptors, and some of them are focused on tributyltin (TBT and its mechanism of action. TBT is an antifouling agent applied in ship’s hull that is constantly released into the water and absorbed by marine organisms, leading to bioaccumulation and biomagnification effects. Thus, several findings of malformations and changes in the normal biochemical and physiologic aspects of these marine animals have been related to TBT contamination. In the present review, we have compiled the most significant studies related to TBT effects in zebrafish, also taking into consideration the effects found in other study models.

Tributyltin and Zebrafish: Swimming in Dangerous Water

Science.gov (United States)

Berto-Júnior, Clemilson; de Carvalho, Denise Pires; Soares, Paula; Miranda-Alves, Leandro

2018-01-01

Zebrafish has been established as a reliable biological model with important insertion in academy (morphologic, biochemical, and pathophysiological studies) and pharmaceutical industry (toxicology and drug development) due to its molecular complexity and similar systems biology that recapitulate those from other organisms. Considering the toxicological aspects, many efforts using zebrafish models are being done in order to elucidate the effects of endocrine disruptors, and some of them are focused on tributyltin (TBT) and its mechanism of action. TBT is an antifouling agent applied in ship’s hull that is constantly released into the water and absorbed by marine organisms, leading to bioaccumulation and biomagnification effects. Thus, several findings of malformations and changes in the normal biochemical and physiologic aspects of these marine animals have been related to TBT contamination. In the present review, we have compiled the most significant studies related to TBT effects in zebrafish, also taking into consideration the effects found in other study models. PMID:29692757

Occurrence of contaminants of emerging concern in mussels (Mytilus spp.) along the California coast and the influence of land use, storm water discharge, and treated wastewater effluent.

Science.gov (United States)

Dodder, Nathan G; Maruya, Keith A; Lee Ferguson, P; Grace, Richard; Klosterhaus, Susan; La Guardia, Mark J; Lauenstein, Gunnar G; Ramirez, Juan

2014-04-30

Contaminants of emerging concern were measured in mussels collected along the California coast in 2009-2010. The seven classes were alkylphenols, pharmaceuticals and personal care products, polybrominated diphenyl ethers (PBDE), other flame retardants, current use pesticides, perfluorinated compounds (PFC), and single walled carbon nanotubes. At least one contaminant was detected at 67 of the 68 stations (98%), and 67 of the 167 analytes had at least one detect (40%). Alkylphenol, PBDE, and PFC concentrations increased with urbanization and proximity to storm water discharge; pesticides had higher concentrations at agricultural stations. These results suggest that certain compounds; for example, alkylphenols, lomefloxacin and PBDE, are appropriate for inclusion in future coastal bivalve monitoring efforts based on maximum concentrations >50 ng/g dry weight and detection frequencies >50%. Other compounds, for example PFC and hexabromocyclododecane (HBCD), may also be suggested for inclusion due to their >25% detection frequency and potential for biomagnification. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mercury distribution in the main compartments of the eutrophic Lake Candia (Northern Italy

Directory of Open Access Journals (Sweden)

Gian Maria BEONE

2009-08-01

Full Text Available Total mercury (T-Hg and organic mercury (mainly methylmercury, MeHg concentrations in the most important compartments (water, sediment, macrophytes, zooplankton, mussels and fish of the shallow and eutrophic Lake Candia (Turin, Northern Italy were measured. The decreasing sequence of the T-Hg concentrations is as follows: cat-fish (143 μg kg-1 d.w., zooplankton (77 μg kg-1 d.w., Unio pictorum mancus (37.9 μg kg-1 d.w., macrophytes (28.9 μg kg-1 d.w.. The content of mercury in mussel tissues increased with the size of the animal, but the relationship between Hg concentration and tissue weight was negative, indicating that the rate of mercury accumulation was lower than the tissue growth rate. The amount of mercury accumulated in the mussels living in the lake sediments was estimated to be 0.54 μg m-2. The importance of mercury biomagnification is also discussed.

Assessment and management of risk to wildlife from cadmium

International Nuclear Information System (INIS)

Burger, Joanna

2008-01-01

Cadmium, a nonessential heavy metal that comes from natural and anthropogenic sources, is a teratogen, carcinogen, and a possible mutagen. Assessment of potential risk from cadmium requires understanding environmental exposure, mainly from ingestion, although there is some local exposure through inhalation. Chronic exposure is more problematic than acute exposure for wildlife. There is evidence for bioaccumulation, particularly in freshwater organisms, but evidence for biomagnification up the food chain is inconsistent; in some bird studies, cadmium levels were higher in species that are higher on the food chain than those that are lower. Some freshwater and marine invertebrates are more adversely affected by cadmium exposure than are birds and mammals. There is very little experimental laboratory research on the effects of cadmium in amphibians, birds and reptiles, and almost no data from studies of wildlife in nature. Managing the risk from cadmium to wildlife involves assessment (including ecological risk assessment), biomonitoring, setting benchmarks of effects, regulations and enforcement, and source reduction

Assessment and management of risk to wildlife from cadmium

Energy Technology Data Exchange (ETDEWEB)

Burger, Joanna [Division of Life Sciences, Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, New Jersey, 08854-8082 (United States)], E-mail: burger@biology.rutgers.edu

2008-01-15

Cadmium, a nonessential heavy metal that comes from natural and anthropogenic sources, is a teratogen, carcinogen, and a possible mutagen. Assessment of potential risk from cadmium requires understanding environmental exposure, mainly from ingestion, although there is some local exposure through inhalation. Chronic exposure is more problematic than acute exposure for wildlife. There is evidence for bioaccumulation, particularly in freshwater organisms, but evidence for biomagnification up the food chain is inconsistent; in some bird studies, cadmium levels were higher in species that are higher on the food chain than those that are lower. Some freshwater and marine invertebrates are more adversely affected by cadmium exposure than are birds and mammals. There is very little experimental laboratory research on the effects of cadmium in amphibians, birds and reptiles, and almost no data from studies of wildlife in nature. Managing the risk from cadmium to wildlife involves assessment (including ecological risk assessment), biomonitoring, setting benchmarks of effects, regulations and enforcement, and source reduction.

Concluding comments: from the worm's view, eco-pharmacodynamics and 2000 A.D

International Nuclear Information System (INIS)

Barbehenn, K.R.

1978-01-01

There may be zoonoses to study (or avoid) in your own backyard but, in any event, a closer look at parasitic worms may shed some light on processes affecting mammalian populations. Here I offer some speculation with varying degrees of empirical and theoretical support. Endoparasites of mammals have different functional relationships with their hosts than do ecotoparasites and insect parasitoids. Since death of the host usually terminates life for the endoparasite, some such parasites may have evolved mechanisms for preventing diseases in their hosts. Parasites may also promote apparent competitive exclusion among similar host species and a likely example is found among the flying squirrels in Eastern United States. Conceivably, parasites may mediate some predator-prey interactions but no examples are available. Adverse impacts of man-made organochlorine compounds, especially on predatory birds and mammals, have been documented, but the associated processes of bioconcentration, bioaccumulation, and biomagnification have not been clarified much beyond the stage of operational definitions

POP bioaccumulation in macroinvertebrates of alpine freshwater systems

International Nuclear Information System (INIS)

Bizzotto, E.C.; Villa, S.; Vighi, M.

2009-01-01

This study serves to investigate the uptake of POPs in the different trophic levels (scrapers, collectors, predators, shredders) of macroinvertebrate communities sampled from a glacial and a non-glacial stream in the Italian Alps. The presented results show that the contaminant concentrations in glacial communities are generally higher compared to those from non-glacial catchments, highlighting the importance of glaciers as temporary sinks of atmospherically transported pollutants. Moreover, the data also suggests that in mountain systems snow plays an important role in influencing macroinvertebrate contamination. The main chemical uptake process to the macroinvertebrates is considered to be bioconcentration from water, as similar contaminant profiles were observed between the different trophic levels. The role of biomagnification/bioaccumulation is thought to be absent or negligible. The enrichment of chemicals observed in the predators is likely to be related to their greater lipid content compared to that of other feeding groups. - Influence of POP release in glacial-fed streams, enhanced by global warming, on pristine aquatic ecosystems.

Preliminary assessment of contaminants in the sediment and organisms of the Swartkops Estuary, South Africa.

Science.gov (United States)

Nel, L; Strydom, N A; Bouwman, H

2015-12-30

Urban estuaries are susceptible to metal and organic pollution, yet most remain understudied in South Africa with respect to the presence, concentrations and distribution of contaminants. Metal and organic chemical concentrations were assessed in sediment and organisms from different trophic levels in the lower reaches of the Swartkops Estuary. Species sampled included Upogebia africana (Malacostraca: Upogebiidae), Gilchristella aestuaria (Clupeidae), Psammogobius knysnaensis (Gobiidae), Mugil cephalus (Mugilidae), Lichia amia (Carangidae), Argyrosomus japonicus (Sciaenidae), Pomadasys commersonnii (Haemulidae) and Larus dominicanus (Avis: Laridae). This study is one of the most comprehensive studies to date assessing pollution levels in a food web in estuaries in South Africa. Due to biomagnification, higher concentrations of Arsenic, Lead, Mercury and Cadmium were found in the juveniles stages of popular angling fishes. High concentrations of Cadmium and Arsenic were recorded in the liver of L. amia, A. japonicus and P. commersonnii which exceed international quality food guidelines. Eggs from the gull, L. dominicanus, showed detectable concentrations of PCBs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Organohalogen compounds in deep-sea fishes from the western North Pacific, off-Tohoku, Japan: Contamination status and bioaccumulation profiles

International Nuclear Information System (INIS)

Takahashi, Shin; Oshihoi, Tomoko; Ramu, Karri; Isobe, Tomohiko; Ohmori, Koji; Kubodera, Tsunemi; Tanabe, Shinsuke

2010-01-01

Twelve species of deep-sea fishes collected in 2005 from the western North Pacific, off-Tohoku, Japan were analyzed for organohalogen compounds. Among the compounds analyzed, concentrations of DDTs and PCBs (up to 23,000 and 12,400 ng/g lipid wt, respectively) were the highest. The present study is the foremost to report the occurrence of brominated flame retardants such as PBDEs and HBCDs in deep-sea organisms from the North Pacific region. Significant positive correlations found between δ 15 N ( per mille ) and PCBs, DDTs and PBDEs suggest the high biomagnification potential of these contaminants in food web. The large variation in δ 13 C ( per mille ) values observed between the species indicate multiple sources of carbon in the food web and specific accumulation of hydrophobic organohalogen compounds in benthic dwelling carnivore species like snubnosed eel. The results obtained in this study highlight the usefulness of deep-sea fishes as sentinel species to monitor the deep-sea environment.

Mercury analysis and speciation: The potential role of the IAEA

International Nuclear Information System (INIS)

Horvat, Milena

2001-01-01

Owing to the toxicity of its methylated form, its accumulation in biota and biomagnification in the aquatic food chain, mercury has been at the centre of considerable attention. Inorganic mercury can be methylated by bacterial action and is stored in the muscle tissue of fish. When ingested by man, it can attack the central nervous system. The US Environmental Protection Agency has already set stringent guidelines for the maximum dietary intake of methyl mercury (0.1 μg/kg/day). Up to 10 million people are involved in the use of mercury in gold exploitation which constitutes a significant pollution source in some countries. The biogeochemistry of mercury and the mercury cycle were reviewed. Long range atmospheric transfer mechanisms have led to significant contamination of fish in lakes remote from any pollution source. The value of stable or radioactive isotopic tracers in understanding the mercury cycle was pointed out and the need for relevant natural matrix reference materials for quality control and method development purposes was stressed

210Po and 210Pb in a pelagic trophic chain

International Nuclear Information System (INIS)

Radakovitch, O.; Strady, E.; Veron, A.; Chiffoleau, J.F.; Tronczynski, J.; Harmelin-Vivien, M.

2013-01-01

The ANR-COSTAS program studied the bioaccumulation and biomagnification of organic and inorganic contaminants through the trophic chains of two small pelagic fish, anchovy and sardine, on the continental shelf of the Gulf of Lion (Northwestern Mediterranean Sea). 210 Po and 210 Pb were analysed at various levels of this trophic chain, as well as trace metal elements, lead isotopes and C and N isotopes which provide additional information on both biogeochemical cycles and trophic transfer. To our knowledge, this is the first time that an entire trophic chain is analysed for these two radionuclides. Water, suspended particles, phytoplankton and zooplankton were collected at 7 stations during two contrast seasons. Phyto and zooplankton were separated in 6 classes through size-sieving: 6-60 μm; 60-200; 200-500; 500-1000; 1000-2000 and > 2000 μm. Anchovy and sardine were collected also two times and analyses were performed on muscle and liver independently for both sexes

Organochlorines in the Vaccares Lagoon trophic web (Biosphere Reserve of Camargue, France)

Energy Technology Data Exchange (ETDEWEB)

Roche, H., E-mail: helene.roche@u-psud.f [Ecologie, Systematique et Evolution, UMR8079 CNRS, Universite Paris-Sud, AgroParisTech, F91405 Orsay Cedex (France); Vollaire, Y.; Persic, A.; Buet, A. [Ecologie, Systematique et Evolution, UMR8079 CNRS, Universite Paris-Sud, AgroParisTech, F91405 Orsay Cedex (France); Oliveira-Ribeiro, C. [Departamento de Biologia Celular, Universidade Federal do Parana, Caixa Postal 19031, CEP: 81.531-990, Curitiba, PR (Brazil); Coulet, E. [Nature Reserve of Camargue, La Capeliere, F13200 Arles (France); Banas, D.; Ramade, F. [Ecologie, Systematique et Evolution, UMR8079 CNRS, Universite Paris-Sud, AgroParisTech, F91405 Orsay Cedex (France)

2009-08-15

During a decade (1996-2006), ecotoxicological studies were carried out in biota of the Vaccares Lagoon (Biosphere Reserve in Rhone Delta, France). A multicontamination was shown at all levels of the trophic web due to a direct bioconcentration of chemical from the medium combined with a food transfer. Here, the pollutants investigated were organochlorines, among which many compounds banned or in the course of prohibition (or restriction) (PCB, lindane, pp'-DDE, dieldrin, aldrin, heptachlor, endosulfan...) and some substances likely still used in the Rhone River basin (diuron, fipronil). The results confirmed the ubiquity of contamination. It proves to be chronic, variable and tends to regress; however contamination levels depend on the trophic compartment. A biomagnification process was showed. A comparison of investigation methods used in other Mediterranean wetlands provides basis of discussion, and demonstrates the urgent need of modelling to assess the ecotoxicological risk in order to improve the management of such protected areas. - The Vaccares Lagoon trophic web biomagnifies organochlorine pollutants.

Baseline mercury and zinc concentrations in terrestrial and coastal organisms of Admiralty Bay, Antarctica

International Nuclear Information System (INIS)

Rodrigues dos Santos, Isaac; Silva-Filho, Emmanoel Vieira; Schaefer, Carlos; Maria Sella, Silvia; Silva, Carlos A.; Gomes, Vicente; Passos, Maria Jose de A.C.R.; Phan Van Ngan

2006-01-01

This paper provides the first quantitative information on mercury in soil, coastal sediment, and in characteristic organisms of terrestrial and shallow coastal marine ecosystems from Admiralty Bay (King George Island, Antarctica). As expected for a remote area, mercury content is low in abiotic components of the ecosystem, and probably similar to natural levels. Mercury also occurs in very low concentrations in the vegetation, invertebrates and fish. These low mercury levels may be due to sulphide formation in reducing sediments of this environment. Higher concentrations of mercury occurred in bird feathers and mammal hair, indicating biomagnification. This was not found for Zinc. These results may be useful as a reference background to detect future inputs of trace elements in this remote area of the earth. Terrestrial vegetation and bird feathers are suggested as target regional biomonitors. - Low levels of mercury and zinc occurred in soil and plant samples from Antarctica, but high levels occurred in birds and mammals

Trace elements and stable isotope ratios (δ13C and δ15N) in fish from deep-waters of the Sulu Sea and the Celebes Sea

International Nuclear Information System (INIS)

Asante, Kwadwo Ansong; Agusa, Tetsuro; Kubota, Reiji; Mochizuki, Hiroko; Ramu, Karri; Nishida, Shuhei; Ohta, Suguru; Yeh, Hsin-ming; Subramanian, Annamalai; Tanabe, Shinsuke

2010-01-01

Trace elements (TEs) and stable isotope ratios (δ 15 N and δ 13 C) were analyzed in fish from deep-water of the Sulu Sea, the Celebes Sea and the Philippine Sea. Concentrations of V and Pb in pelagic fish from the Sulu Sea were higher than those from the Celebes Sea, whereas the opposite trend was observed for δ 13 C. High concentrations of Zn, Cu and Ag were found in non-migrant fish in deep-water, while Rb level was high in fish which migrate up to the epipelagic zone, probably resulting from differences in background levels of these TEs in each water environment or function of adaptation to deep-water by migrant and non-migrant species. Arsenic level in the Sulu Sea fish was positively correlated with δ 15 N, indicating biomagnification of arsenic. To our knowledge, this is the first study on relationship between diel vertical migration and TE accumulation in deep-water fish.

Confirmatory Factor Analysis of WAIS-IV in a Clinical Sample: Examining a Bi-Factor Model

Directory of Open Access Journals (Sweden)

Rachel Collinson

2016-12-01

Full Text Available There have been a number of studies that have examined the factor structure of the Wechsler Adult Intelligence Scale IV (WAIS-IV using the standardization sample. In this study, we investigate its factor structure on a clinical neuropsychology sample of mixed aetiology. Correlated factor, higher-order and bi-factor models are all tested. Overall, the results suggest that the WAIS-IV will be suitable for use with this population.

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...... 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 distinct factors: system quality...

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.

Sparse and Robust Factor Modelling

NARCIS (Netherlands)

C. Croux (Christophe); P. Exterkate (Peter)

2011-01-01

textabstractFactor construction methods are widely used to summarize a large panel of variables by means of a relatively small number of representative factors. We propose a novel factor construction procedure that enjoys the properties of robustness to outliers and of sparsity; that is, having

Exploratory Bi-factor Analysis: The Oblique Case

OpenAIRE

Jennrich, Robert L.; Bentler, Peter M.

2011-01-01

Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger and Swineford (1937). The bi-factor model has a general factor, a number of group factors, and an explicit bi-factor structure. Jennrich and Bentler (2011) introduced an exploratory form of bi-factor analysis that does not require one to provide an explicit bi-factor structure a priori. They use exploratory factor analysis and a bi-factor rotation criterion designed to produce a rotated loading mat...

Electromagnetic Hadronic Form-Factors

International Nuclear Information System (INIS)

Edwards, Robert G.

2005-01-01

We present a calculation of the nucleon electromagnetic form-factors as well as the pion and rho to pion transition form-factors in a hybrid calculation with domain wall valence quarks and improved staggered (Asqtad) sea quarks

Intrinsic-extrinsic factors in sport motivation.

Science.gov (United States)

Pedersen, Darhl M

2002-10-01

Participants were 83 students (36 men and 47 women). 10 intrinsic-extrinsic factors involved in sport motivation were obtained. The factors were generated from items obtained from the participants rather than items from the experimenter. This was done to avoid the possible influence of preconceptions on the part of the experimenter regarding what the final dimensions may be. Obtained motivational factors were Social Reinforcement, Fringe Benefits, Fame and Fortune, External Forces, Proving Oneself, Social Benefits, Mental Enrichment, Expression of Self, Sense of Accomplishment, and Self-enhancement. Each factor was referred to an intrinsic-extrinsic dimension to describe its relative position on that dimension. The order of the factors as listed indicates increasing intrinsic motivation. i.e., the first four factors were rated in the extrinsic range, whereas the remaining six were rated to be in the intrinsic range. Next, the participants rated the extent to which each of the various factors was involved in their decision to participate in sport activities. The pattern of use of the motivational factors was the same for both sexes except that men indicated greater use of the Fringe Benefits factor. Overall, the more intrinsic a sport motivation factor was rated, the more likely it was to be rated as a factor in actual sport participation.

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

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...

Biomagnification of some heavy and essential metals in sediments, fishes and crayfish from Ondo State coastal region, Nigeria

International Nuclear Information System (INIS)

Asaolu, S.S.; Olaofe, O.

2005-01-01

The bio magnifications levels of some essential (Fe, Zn, Cu) and toxic metals (Pb, Ni, Cd, Cr, Co, Mn) were determined in sediments, three kinds of fish (Oreochromis niloticus, Synodonthis sp., and Clarias gariepinus) and crayfish from the Ondo State coastal region. The metal bio magnification in the fish and crayfish was several times greater than in water, while that in the sediments was several thousand-folds greater than in both the organisms and water. Among the metals examined in water, Fe was the most abundant with average values of 146.7 and 74.3 mg/1, respectively, for wet and dry seasons, while Co was the least with average values of 2.4 and 1.6 mg/1. In the sediments, concentrations of Pb, Ni, Fe, Cr, Co and Mn in the wet season were relatively higher than those obtained for the dry season. Fe with an average of 50.9 mg/kg in C, gariepinus was the most abundant metal in the fish samples, while Cu with an average value of 0.3 mg/kg in O. niloticus was the least. The metal bio magnification for most of the metals for both seasons was found to vary widely from one location to the other. This was confirmed by the coefficient of variation that ranged from 31% to 144% and 29% to 130% in the wet and dry seasons, respectively. The present study has shown that fish, crayfish and sediments can be used to monitor the pollution level of metals in the Nigerian coastal water. (author)

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

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.

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.

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

[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.

Factors that regulate embryonic gustatory development

Directory of Open Access Journals (Sweden)

Krimm Robin F

2007-09-01

Full Text Available Abstract Numerous molecular factors orchestrate the development of the peripheral taste system. The unique anatomy/function of the taste system makes this system ideal for understanding the mechanisms by which these factors function; yet the taste system is underutilized for this role. This review focuses on some of the many factors that are known to regulate gustatory development, and discusses a few topics where more work is needed. Some attention is given to factors that regulate epibranchial placode formation, since gustatory neurons are thought to be primarily derived from this region. Epibranchial placodes appear to arise from a pan-placodal region and a number of regulatory factors control the differentiation of individual placodes. Gustatory neuron differentiation is regulated by a series of transcription factors and perhaps bone morphongenic proteins (BMP. As neurons differentiate, they also proliferate such that their numbers exceed those in the adult, and this is followed by developmental death. Some of these cell-cycling events are regulated by neurotrophins. After gustatory neurons become post-mitotic, axon outgrowth occurs. Axons are guided by multiple chemoattractive and chemorepulsive factors, including semaphorins, to the tongue epithelium. Brain derived neurotrophic factor (BDNF, functions as a targeting factor in the final stages of axon guidance and is required for gustatory axons to find and innervate taste epithelium. Numerous factors are involved in the development of gustatory papillae including Sox-2, Sonic hedge hog and Wnt-β-catenin signaling. It is likely that just as many factors regulate taste bud differentiation; however, these factors have not yet been identified. Studies examining the molecular factors that regulate terminal field formation in the nucleus of the solitary tract are also lacking. However, it is possible that some of the factors that regulate geniculate ganglion development, outgrowth, guidance and

Skewed factor models using selection mechanisms

KAUST Repository

Kim, Hyoung-Moon

2015-12-21

Traditional factor models explicitly or implicitly assume that the factors follow a multivariate normal distribution; that is, only moments up to order two are involved. However, it may happen in real data problems that the first two moments cannot explain the factors. Based on this motivation, here we devise three new skewed factor models, the skew-normal, the skew-tt, and the generalized skew-normal factor models depending on a selection mechanism on the factors. The ECME algorithms are adopted to estimate related parameters for statistical inference. Monte Carlo simulations validate our new models and we demonstrate the need for skewed factor models using the classic open/closed book exam scores dataset.

Skewed factor models using selection mechanisms

KAUST Repository

Kim, Hyoung-Moon; Maadooliat, Mehdi; Arellano-Valle, Reinaldo B.; Genton, Marc G.

2015-01-01

Traditional factor models explicitly or implicitly assume that the factors follow a multivariate normal distribution; that is, only moments up to order two are involved. However, it may happen in real data problems that the first two moments cannot explain the factors. Based on this motivation, here we devise three new skewed factor models, the skew-normal, the skew-tt, and the generalized skew-normal factor models depending on a selection mechanism on the factors. The ECME algorithms are adopted to estimate related parameters for statistical inference. Monte Carlo simulations validate our new models and we demonstrate the need for skewed factor models using the classic open/closed book exam scores dataset.

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.

Cardiovascular risk factors and dementia.

Science.gov (United States)

Fillit, Howard; Nash, David T; Rundek, Tatjana; Zuckerman, Andrea

2008-06-01

Dementias, such as Alzheimer's disease (AD) and vascular dementia, are disorders of aging populations and represent a significant economic burden. Evidence is accumulating to suggest that cardiovascular disease (CVD) risk factors may be instrumental in the development of dementia. The goal of this review was to discuss the relationship between specific CVD risk factors and dementia and how current treatment strategies for dementia should focus on reducing CVD risks. We conducted a review of the literature for the simultaneous presence of 2 major topics, cardiovascular risk factors and dementia (eg, AD). Special emphasis was placed on clinical outcome studies examining the effects of treatments of pharmacologically modifiable CVD risk factors on dementia and cognitive impairment. Lifestyle risk factors for CVD, such as obesity, lack of exercise, smoking, and certain psychosocial factors, have been associated with an increased risk of cognitive decline and dementia. Some evidence suggests that effectively managing these factors may prevent cognitive decline/dementia. Randomized, placebo-controlled trials of antihypertensive medications have found that such therapy may reduce the risk of cognitive decline, and limited data suggest a benefit for patients with AD. Some small open-label and randomized clinical trials of statins have observed positive effects on cognitive function; larger studies of statins in patients with AD are ongoing. Although more research is needed, current evidence indicates an association between CVD risk factors--such as hypertension, dyslipidemia, and diabetes mellitus--and cognitive decline/dementia. From a clinical perspective, these data further support the rationale for physicians to provide effective management of CVD risk factors and for patients to be compliant with such recommendations to possibly prevent cognitive decline/dementia.

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.

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.

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.

The translation factors of Drosophila melanogaster.

Science.gov (United States)

Marygold, Steven J; Attrill, Helen; Lasko, Paul

2017-01-02

Synthesis of polypeptides from mRNA (translation) is a fundamental cellular process that is coordinated and catalyzed by a set of canonical 'translation factors'. Surprisingly, the translation factors of Drosophila melanogaster have not yet been systematically identified, leading to inconsistencies in their nomenclature and shortcomings in functional (Gene Ontology, GO) annotations. Here, we describe the complete set of translation factors in D. melanogaster, applying nomenclature already in widespread use in other species, and revising their functional annotation. The collection comprises 43 initiation factors, 12 elongation factors, 3 release factors and 6 recycling factors, totaling 64 of which 55 are cytoplasmic and 9 are mitochondrial. We also provide an overview of notable findings and particular insights derived from Drosophila about these factors. This catalog, together with the incorporation of the improved nomenclature and GO annotation into FlyBase, will greatly facilitate access to information about the functional roles of these important proteins.

Voice disorders in teachers: occupational risk factors and psycho-emotional factors.

Science.gov (United States)

van Houtte, Evelyne; Claeys, Sofie; Wuyts, Floris; van Lierde, Kristiane

2012-10-01

Teaching is a high-risk occupation for developing voice disorders. The purpose of this study was to investigate previously described vocal risk factors as well as to identify new risk factors related to both the personal life of the teacher (fluid intake, voice-demanding activities, family history of voice disorders, and children at home) and to environmental factors (temperature changes, chalk use, presence of curtains, carpet, or air-conditioning, acoustics in the classroom, and noise in and outside the classroom). The study group comprised 994 teachers (response rate 46.6%). All participants completed a questionnaire. Chi-square tests and logistic regression analyses were performed. A total of 51.2% (509/994) of the teachers presented with voice disorders. Women reported more voice disorders compared to men (56.4% versus 40.4%, P history of voice disorders (P = 0.005), temperature changes in the classroom (P = 0.017), the number of pupils per classroom (P = 0.001), and noise level inside the classroom (P = 0.001). Teachers with voice disorders presented a higher level of psychological distress (P < 0.001) compared to teachers without voice problems. Voice disorders are frequent among teachers, especially in female teachers. The results of this study emphasize that multiple factors are involved in the development of voice disorders.

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

A transcription factor active on the epidermal growth factor receptor gene

International Nuclear Information System (INIS)

Kageyama, R.; Merlino, G.T.; Pastan, I.

1988-01-01

The authors have developed an in vitro transcription system for the epidermal growth factor receptor (EGFR) oncogene by using nuclear extracts of A431 human epidermoid carcinoma cells, which overproduce EGFR. They found that a nuclear factor, termed EGFR-specific transcription factor (ETF), specifically stimulated EGFR transcription by 5- to 10-fold. In this report, ETF, purified by using sequence-specific oligonucleotide affinity chromatography, is shown by renaturing material eluted from a NaDodSO 4 /polyacrylamide gel to be a protein with a molecular mass of 120 kDa. ETF binds to the promoter region, as measured by DNase I footprinting and gel-mobility-shift assays, and specifically stimulates the transcription of the EGFR gene in a reconstituted in vitro transcription system. These results suggest that ETF could play a role in the overexpression of the cellular oncogene EGFR

Serum Adiponectin and Leptin Concentrations in Relation to Body Fat Distribution, Hematological Indices and Lipid Profile in Humans

Directory of Open Access Journals (Sweden)

Anna Lubkowska

2015-09-01

Full Text Available The purpose of the study was to evaluate the relationship between serum adiponectin and leptin concentrations and body composition, hematological indices and lipid profile parameters in adults. The study involved 95 volunteers (BMI from 23.3 to 53 kg/m2. Anthropometric parameters were measured: body weight and height, waist and hip circumference, waist-to-hip ratio, body fat mass (BMF, subcutaneous and visceral fat mass (SFM, VFM, lean body mass (LBM, skeletal muscle mass (SMM. In serum we determined adiponectin and leptin concentrations, extracellular hemoglobin, total bilirubin, as well as lipid metabolism (TCh, HDL-Ch, LDL-Ch, TG. Mean adipokine levels were significantly higher in women (p ≤ 0.01, adiponectin significantly negatively correlated with body height and weight, systolic blood pressure and absolute LBM and SMM values. The same relation was observed for erythroid system indicators and lipid indicators. A positive correlation was exceptionally found between adiponectin and HDL-Ch. LEP negatively correlated with some percentage rates (%LBM, %SMM. Only in women, we observed a positive correlation between LEP and body weight, BMI and WHR. Studies on ADPN and the ADPN/LEP ratio as a valuable complementary diagnostic element in the prediction and prevention of cardiovascular diseases need to be continued.

Deriving a blood-mimicking fluid for particle image velocimetry in Sylgard-184 vascular models.

Science.gov (United States)

Yousif, Majid Y; Holdsworth, David W; Poepping, Tamie L

2009-01-01

A new blood-mimicking fluid (BMF) has been developed for particle image velocimetry (PIV), which enables flow studies in vascular models (phantoms). A major difficulty in PIV that affects measurement accuracy is the refraction and distortion of light passing through the interface between the model and the fluid, due to the difference in refractive index (n) between the two materials. The problem can be eliminated by using a fluid with a refractive index matching that of the model. Such fluids are not commonly available, especially for vascular research where the fluid should also have a viscosity similar to human blood. In this work, a blood-mimicking fluid, composed of water (47.38% by weight), glycerol (36.94% by weight) and sodium iodide salt (15.68% by weight), was developed for compatibility with our silicone (Sylgard 184; n = 1.414) phantoms. The fluid exhibits a dynamic viscosity of 4.31+/-0.03 cP which lies within the range of human blood viscosity (4.4+/-0.6 cP). Both refractive index and viscosity were attained at 22.2+/-0.2 degrees C, which is a feasible room temperature, thus eliminating the need for a temperature-control system. The fluid will be used to study hemodynamics in vascular flow models fabricated from Sylgard 184.