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Sample records for orconectes limosus exposed

  1. Markers of oxidative stress in hepatopancreas of crayfish (Orconectes limosus, raf) experimentally exposed to nanosilver.

    PubMed

    Strużyński, Witold; Dąbrowska-Bouta, Beata; Grygorowicz, Tomasz; Ziemińska, Elżbieta; Strużyńska, Lidia

    2014-11-01

    Silver nanoparticles, chemically neutral particles in the size range of 1-100 nm, express strong antimicrobial activity and therefore have a broad range of applications. The increased use of consumer products with nanosilver (nanoAg) may result in its release into the environment, and may particularly affect aquatic systems. The mechanisms of the harmful effects of nanoAg against aquatic organisms are unclear. Therefore, in the present study we investigate the pro-oxidative potential of these nanoparticles in experimentally exposed crayfish Orconectes limosus. Markers of oxidative stress and parameters of the antioxidant cell defense system such as total glutathione, glutathione reductase and the level of sulfhydryl groups were examined in the hepatopancreas of both sexes of O. limosus collected seasonally from Białe Lake (Poland) and subsequently exposed to nanoAg particles for 2 weeks. Exposure to nanoAg led to a high concentration-dependent increase in the rate of lipid peroxidation and a decrease of protein-bound SH groups which indicates protein oxidation. These markers of oxidative stress were accompanied by decreased levels of thiols and reduced activity of glutathione reductase. These results indicate a deficiency of reduced glutathione and suggest that the exposed organisms have less efficient antioxidative mechanisms available to counter ROS-mediated cellular stress. Furthermore, we find that confocal microscopy is of limited utility in monitoring the presence of silver nanoparticles in tissues of exposed crayfish.

  2. Population Density of the Crayfish, Orconectes limosus, in Relation to Fish and Macroinvertebrate Densities in a Small Mesotrophic Lake - Implications for the Lake's Food Web

    NASA Astrophysics Data System (ADS)

    Haertel-Borer, Susanne S.; Zak, Dominik; Eckmann, Reiner; Baade, Ulrich; Hölker, Franz

    2005-12-01

    The population density of Orconectes limosus in a mesotrophic lake was assessed in the context of fish and macroinvertebrate biomasses, and crayfish consumption by fish. The average O. limosus (6 cm total length) abundance and biomass in the littoral zone was 2200 ind ha-1 and 32.2 kg ha1, respectively. O. limosus biomass accounted for a large percentage (49%) of the lake's macroinvertebrate biomass. O. limosus was equal to 35% of the non-predatory fish biomass and to 81% of the predatory fish biomass. O. limosus comprised 15 and 48% of the annual consumption of pike and predatory perch, respectively. Altogether, O. limosus was identified as quantitatively important for the lake's littoral food web, and might also subsidize the pelagic food web. This strengthens the need for an integrated view on lake food webs.

  3. Comparison of directional selectivity in identified spiking and nonspiking mechanosensory neurons in the crayfish Orconectes limosus.

    PubMed Central

    Tautz, J; Plummer, M R

    1994-01-01

    We have recorded electrical activity from two identified synaptically coupled mechanosensory interneurons in the abdominal nervous system of the crayfish Orconectes limosus and have studied their responses to constant-velocity water-jet stimuli presented from different directions. The two neurons, the ascending caudal photoreceptor (CPR) and the local directionally selective neuron, responded preferentially to stimuli delivered ipsilaterally to their dendritic input regions. Both neurons featured responses consisting of a phasic excitatory "on" response and a tonic depolarizing plateau. The different response components showed various degrees of directional selectivity: The initial "on" peak of the response was the least sensitive and the plateau was the most sensitive to stimulus direction. The CPR showed a sharp cut-off in responsiveness to contralateral stimuli, whereas the local directionally selective neuron showed a more gradual decrease in its directional responsiveness. This difference is a consequence of the feed-forward lateral inhibition that the local directionally selective neuron exerts on the CPR and of the threshold for initiation of action potentials in the CPR. A comparison of the spiking response of the CPR with its generator potential shows that the number and frequency of action potentials are a more sensitive indicator of directional preference than the generator potential response. The directional characteristic of the CPR is discussed as a filter matched to a specific spatial aspect of biologically relevant water movements. Images PMID:7517037

  4. Temporal dynamics of spore release of the crayfish plague pathogen from its natural host, American spiny-cheek crayfish (Orconectes limosus), evaluated by transmission experiments.

    PubMed

    Svoboda, J; Kozubíková-Balcarová, E; Kouba, A; Buřič, M; Kozák, P; Diéguez-Uribeondo, J; Petrusek, A

    2013-05-01

    The crayfish plague pathogen, Aphanomyces astaci, is one of the most serious threats to indigenous European crayfish species. The North American invasive spiny-cheek crayfish, Orconectes limosus, is an important source of this pathogen in central and western Europe. We evaluated potential changes in A. astaci spore release rate from infected individuals of this species by experiments investigating the pathogen transmission to susceptible noble crayfish, Astacus astacus. We filtered defined volumes of water regularly to quantify spore concentration, and sampled crayfish tissues at the end of the experiment. The filters and tissues were then tested for the presence of A. astaci DNA by species-specific quantitative PCR. Additionally, we tested the efficiency of horizontal transmission to apparently uninfected O. limosus. The experiments confirmed that A. astaci can be transmitted to susceptible crayfish during intermoult periods, and that the pathogen was more frequently detected in noble crayfish recipients than in American ones. The pathogen spore concentrations substantially varied in time, and significantly increased during moulting of infected hosts. Our study strengthens the evidence that although the likelihood of crayfish plague transmission by water transfer from localities with infected American crayfish might increase when these are moulting or dying, no time-periods can be proclaimed safe.

  5. Draft genome sequence of Inquilinus limosus strain MP06, a multidrug-resistant clinical isolate

    PubMed Central

    Pino, Marylú; Conza, José Di; Gutkind, Gabriel

    2015-01-01

    The bacterium, Inquilinus limosus, with its remarkable antimicrobial multiresistant profile, has increasingly been isolated in cystic fibrosis patients. We report draft genome sequence of a strain MP06, which is of considerable interest in elucidating the associated mechanisms of antibiotic resistance in this bacterium and for an insight about its persistence in airways of these patients. PMID:26691451

  6. First report on toxins in the Panamanian toads Atelopus limosus, A. glyphus and A. certus.

    PubMed

    Yotsu-Yamashita, Mari; Tateki, Eiko

    2010-01-01

    Major toxins from skin extracts of 18 specimens of six Atelopus toad species collected in Panama were analyzed. Chiriquitoxin was identified using (1)H NMR in A. limosus and A. glyphus for the first time. Zetekitoxin in A. zeteki and tetrodotoxin in A. varius, A. chiriquiensis and A. zeteki were identified again. Furthermore, A. certus was suggested to contain a water-soluble toxin other than tetrodotoxin. PMID:19596024

  7. Crayfish (Orconectes virilis) predation on zebra mussels (Dreissena polymorpha)

    USGS Publications Warehouse

    Love, Joy; Savino, Jacqueline F.

    1993-01-01

    In laboratory studies, we quantified predation rates and handling time of crayfish (Orconectes virilis) on zebra mussels (Dreissena polymorpha) and rainbow trout (Oncorhhynchus mykiss) eggs. In single prey species tests, crayfish ate zebra mussels at similar rates as they ate rainbow trout eggs. When both prey were present, crayfish preferred rainbow trout eggs. Handling time of mussels was about twice that of rainbow trout eggs, and energetic content of mussels was lower. Therefore, net benefit for foraging on rainbow trout eggs was about three times that of foraging on zebra mussels.

  8. Olfactory Sampling Recovery Following Sublethal Copper Exposure in the Rusty Crayfish, Orconectes rusticus.

    PubMed

    Lahman, Sara E; Moore, Paul A

    2015-10-01

    Increasing levels of anthropogenic chemicals within an aquatic ecosystem may inhibit animals from extracting information from chemical signals. We investigated whether antennular flicking, a behavioral mechanism involved in chemically-mediated behaviors of the rusty crayfish, Orconectes rusticus, was altered following a sublethal copper exposure (450 µg/L). Crayfish exposed to copper exhibited lower flicking rates than control crayfish and were significantly less successful in their ability to orient to a food odor. Copper was then eliminated from the housing tanks, providing a recovery period. Groups of crayfish were assayed for antennular flicking rates and orientation success three times over the course of the 21 day recovery period. Crayfish demonstrated significant increases in rates of successful localization of odors and antennular flicking during this portion of the experiment. These results indicate that the mechanism by which copper impairs chemoreception in the rusty crayfish is reversible if elevated levels of copper concentrations are eliminated from aquatic ecosystems contaminated by runoff from agricultural or aquacultural chemicals.

  9. The Effects of Biodiesel and Crude Oil on the Foraging Behavior of Rusty Crayfish, Orconectes rusticus.

    PubMed

    Jurcak, Ana M; Gauthier, Steven J; Moore, Paul A

    2015-11-01

    Environmental pollutants, such as crude oil and other petroleum-based fuels, inhibit and limit an organism's ability to perceive a chemical stimulus. Despite the increased use of alternative fuels, such as biodiesel, there have been few studies investigating the impact of these chemicals on the behavior of aquatic organisms. The purpose of this study was to compare the sublethal effects of biodiesel and crude oil exposure on chemically mediated behaviors in a freshwater keystone species. Crayfish (Orconectes rusticus) were tested on their ability to respond appropriately to a positive chemical stimulus within a Y-maze choice paradigm. Behavior was quantified by measuring time spent finding an odor source, duration of time spent at the odor source, percentage of crayfish that found the odor source, and percentage of crayfish that chose the correct arm of the arena. Results indicated negative impacts of both biodiesel and crude oil on the ability of crayfish to locate the food source. However, there were no significant differences between behavioral performances when crayfish were exposed to crude oil compared with biodiesel. Thus, biodiesel and crude oil have equally negative effects on the chemosensory behavior of crayfish. These findings indicate that biodiesel has the potential to have similar negative ecological impacts as other fuel source toxins.

  10. Sublethal copper toxicity impairs chemical orientation in the crayfish, Orconectes rusticus.

    PubMed

    Lahman, Sara E; Trent, Kaitlyn R; Moore, Paul A

    2015-03-01

    Before reaching concentrations that are high enough to cause mortality, elevated levels of chemical pollution can significantly alter a keystone indicator species' ability to extract sensory information. To organisms that rely on chemical signals to make crucial ecological decisions, increased amounts of a pollutant may impact chemoreceptive abilities by altering the perception of the sensory landscape or impairing the functioning of sensory organs. Heavy metal pollutants entering an aquatic ecosystem are of increasing concern due to discernible effects on chemoreception in many ecologically and economically important species. In order to determine the effects of sublethal copper toxicity on chemically mediated behavior, male and female rusty crayfish, Orconectes rusticus, were exposed to ecologically relevant concentrations of copper (4.5, 45, and 450 µg/l) for 120 h. Following exposure, crayfish were allowed to orient toward a food odor stimulus. During orientation trials, select crayfish oriented under a point or nonpoint source copper background pollutant at the same concentration as the exposure period. Orientation trials were videotaped and analyzed using EthoVision XT 8.5 (Noldus Information Technology, The Netherlands) for differences in overall success in locating the food source and orienting parameters. Significant differences were found in the overall orientation ability of O. rusticus to locate an odor source when previously exposed to copper in combination with a source of pollution in the background of orientation trials. Crayfish exposed to copper in any capacity during the experiment (regardless of concentration or background during trials) showed slower walking speeds toward the source, decreased turning angles, increased heading angles toward the source, and decreased upstream heading angles. Results from this experiment support that copper impairs the ability of crayfish to detect, process, and/or respond appropriately to chemosensory

  11. Characterizing the Invasion Front of the Rusty Crayfish, Orconectes Rusticus, in a Pennsylvania Stream

    NASA Astrophysics Data System (ADS)

    Wagner, J. M.; Wallace, J. R.; Perry, W. L.

    2005-05-01

    The rusty crayfish, Orconectes rusticus, was an unknown species in Pennsylvania during the last major assessment of crayfish as documented in a 1906 survey. An intensive survey of Lancaster County, Pennsylvania in 2000 revealed that O. rusticus had successfully invaded many streams. Orconectes rusticus are also sold in local bait shops suggesting its introduction was likely due to its use as bait. Orconectes rusticus has the potential to cause serious ecological harm to aquatic systems by displacing native crayfish species via competition and hybridization leading to alteration of food web dynamics. In order to predict the extent of invasions, identification of the physical and chemical parameters predisposing stream habitats to invasion is needed. Our objectives were to determine how a suite of physical and chemical parameters might influence the distribution of crayfish species along a stream continuum, with particular emphasis on characterizing the invasion front of Orconectes rusticus. Rather than an invasion front, we encountered a distinct invasion boundary created by a natural series of small waterfalls. Our data suggest that parameters such as water velocity, depth, pH, and temperature have little effect on the distribution and invasion of Orconectes rusticus along a stream continuum when natural barriers are present.

  12. The effects of bt corn on rusty crayfish (Orconectes rusticus) growth and survival.

    PubMed

    Linn, Matthew D; Moore, Paul A

    2014-10-01

    Bt crops are one of the most commonly used genetically modified crops worldwide. Bt crops contain a gene that is derived from the bacteria Bacillus thuringiensis, which produces the Cry1Ab toxin. Bt corn that contains the Cry1Ab toxin is used throughout the Midwest United States to control crop pests such as the European corn borer (Ostrinia nubilalis). Headwater streams in regions known for intensive agriculture receive Bt corn detritus after the fall harvest, which is then consumed by a diverse community of stream invertebrates. The rusty crayfish (Orconectes rusticus) is a common invertebrate detritivore in these headwater streams. Both isogenic and Bt corn were grown under the controlled environmental conditions of a greenhouse and, after senescence, were tested for nutritional equality. Rusty crayfish were exposed to one of several detrital treatments composed of Bt corn, Bt corn plus American sycamore (Platanus occidentalis), isogenic corn alone, isogenic corn plus P. occidentalis, or P. occidentalis alone for 8 weeks. Both strains of corn were grown under the controlled environmental conditions in a greenhouse and were tested for nutritional equality after senescence. Crayfish were housed in live streams with a water temperature of 12.8 °C and a 12:12 h light-to-dark photoperiod. Survival and growth of animals within each experimental treatment were monitored each week. After 8 weeks of exposure, there was no statistically significant difference in growth between crayfish in Bt and isogenic treatments. However, survivorship was 31 % lower in the Bt treatment compared with the isogenic treatment. These results suggest that the Bt corn and isogenic corn were of equivalent nutritional value but that Bt corn does have a toxic effect on rusty crayfish during long-term exposure.

  13. The effects of bt corn on rusty crayfish (Orconectes rusticus) growth and survival.

    PubMed

    Linn, Matthew D; Moore, Paul A

    2014-10-01

    Bt crops are one of the most commonly used genetically modified crops worldwide. Bt crops contain a gene that is derived from the bacteria Bacillus thuringiensis, which produces the Cry1Ab toxin. Bt corn that contains the Cry1Ab toxin is used throughout the Midwest United States to control crop pests such as the European corn borer (Ostrinia nubilalis). Headwater streams in regions known for intensive agriculture receive Bt corn detritus after the fall harvest, which is then consumed by a diverse community of stream invertebrates. The rusty crayfish (Orconectes rusticus) is a common invertebrate detritivore in these headwater streams. Both isogenic and Bt corn were grown under the controlled environmental conditions of a greenhouse and, after senescence, were tested for nutritional equality. Rusty crayfish were exposed to one of several detrital treatments composed of Bt corn, Bt corn plus American sycamore (Platanus occidentalis), isogenic corn alone, isogenic corn plus P. occidentalis, or P. occidentalis alone for 8 weeks. Both strains of corn were grown under the controlled environmental conditions in a greenhouse and were tested for nutritional equality after senescence. Crayfish were housed in live streams with a water temperature of 12.8 °C and a 12:12 h light-to-dark photoperiod. Survival and growth of animals within each experimental treatment were monitored each week. After 8 weeks of exposure, there was no statistically significant difference in growth between crayfish in Bt and isogenic treatments. However, survivorship was 31 % lower in the Bt treatment compared with the isogenic treatment. These results suggest that the Bt corn and isogenic corn were of equivalent nutritional value but that Bt corn does have a toxic effect on rusty crayfish during long-term exposure. PMID:25001246

  14. Effects of sublethal exposure to cadmium on shelter-seeking behavior of juvenile Orconectes rusticus (Girard) crayfish

    SciTech Connect

    Alberstadt, P.; Steele, C.; Misra, K.; Skinner, C.; Wilson, B.; Robaskiewicz, S.

    1999-07-01

    Sublethal behavioral effect of heavy metals on crayfishes may adversely effect their survival in the environment. They may experience increased predation due to changes in their ability to remain in or under shelter. The effect of sublethal cadmium exposure on the ability of juvenile Orconectes rusticus crayfish to remain in shelter was evaluated. Four different treatment groups were used: a control group not exposed to cadmium, and three experimental groups exposed to 1, 2 ,or 3 mg Cd/L for 7 days. Crayfish were placed, individually, into small glass aquaria containing 3 L of laboratory water, with continuous aeration. Each crayfish was provided with a dark, thigmotactic shelter. Cadmium was introduced into the aquaria on days 1 and 4 to establish and maintain the nominal concentration. On days 5 through 7, observations were taken on each crayfish five times per day, with a minimum of 30 minutes between observations. The locations of the animals were recorded as in cover or in the open area of an aquarium. Repeated measures ANOVA was used to examine the effects of sublethal exposure to cadmium on shelter use by the juveniles.

  15. The Effect of the Crayfish Orconectes virilis (Crustacea: Decapoda: Cambaridae) in the Decomposition and Succession of Submerged Small Mammal Carrion

    NASA Astrophysics Data System (ADS)

    de Jong, G. D.; Chadwick, J. W.

    2005-05-01

    The role of the crayfish Orconectes virilis in the decomposition of submerged rat carrion and succession of other benthic macroinvertebrates was experimentally investigated in Slaughterhouse Gulch, a small, urban stream in Littleton, Colorado. Crayfish participation in carrion decomposition significantly altered the decomposition rate of the carrion. Nine carcasses were exposed in anchored minnow traps at three degrees of crayfish access: crayfish always present, crayfish having free access, and crayfish excluded. These three treatments required 23 days, 29 days, and 65 days, respectively, for complete decomposition of the rat carrion (<2% original biomass). Sample variability increased with number of crayfish present, especially as decomposition proceeded. Seven other macroinvertebrate taxa were collected from the carcasses, but their presence or absence could not be correlated with crayfish presence. The leech Haemopis marmoratus was generally the first macroinvertebrate to arrive at the carrion, being present in densities of <5 individuals/carcass early in succession and in larger densities (up to 25 individuals/carcass) after extensive decomposition and exposure of the viscera.

  16. Fine structure of the spermatozoon in three species of Cambaridae (Arthropoda: Crustacea: Decapoda) Cambarus robustus, Orconectes propinquus and Orconectes rusticus: a comparative biometrical study.

    PubMed

    Yazicioglu, Buket; Hamr, Přemek; Kozák, Pavel; Kouba, Antonín; Niksirat, Hamid

    2016-01-01

    The ultrastructure of spermatozoa in three species of cambarid crayfish, Cambarus robustus, Orconectes propinquus, and Orconectes rusticus, were studied and compared with eight previously studied species from different crayfish families using morphological features and biometrical data. The ultrastructure of spermatozoa show a generally conserved pattern including an acrosome and nucleus in the anterior and posterior parts of the cell, respectively, radial arms that wrap around the nucleus, and the whole cell is enclosed by an extracellular capsule. The most outstanding morphological feature in spermatozoa of three studied cambarid crayfish is the crest-like protrusions in the anterior part of the acrosome that can be used as one of the features for distinguishing the members of this family. Results of biometrical data reveal that acrosome size in the representatives of Parastacidae are the smallest, while representatives of Astacidae show the biggest acrosome. The acrosome size in species belonging to Cambaridae occupy an intermediate position between the two other families of freshwater crayfish. In conclusion, a combination of morphological features and biometrical data of spermatozoa can help distinguishing different species of the freshwater crayfish. PMID:27635333

  17. Fine structure of the spermatozoon in three species of Cambaridae (Arthropoda: Crustacea: Decapoda) Cambarus robustus, Orconectes propinquus and Orconectes rusticus: a comparative biometrical study.

    PubMed

    Yazicioglu, Buket; Hamr, Přemek; Kozák, Pavel; Kouba, Antonín; Niksirat, Hamid

    2016-01-01

    The ultrastructure of spermatozoa in three species of cambarid crayfish, Cambarus robustus, Orconectes propinquus, and Orconectes rusticus, were studied and compared with eight previously studied species from different crayfish families using morphological features and biometrical data. The ultrastructure of spermatozoa show a generally conserved pattern including an acrosome and nucleus in the anterior and posterior parts of the cell, respectively, radial arms that wrap around the nucleus, and the whole cell is enclosed by an extracellular capsule. The most outstanding morphological feature in spermatozoa of three studied cambarid crayfish is the crest-like protrusions in the anterior part of the acrosome that can be used as one of the features for distinguishing the members of this family. Results of biometrical data reveal that acrosome size in the representatives of Parastacidae are the smallest, while representatives of Astacidae show the biggest acrosome. The acrosome size in species belonging to Cambaridae occupy an intermediate position between the two other families of freshwater crayfish. In conclusion, a combination of morphological features and biometrical data of spermatozoa can help distinguishing different species of the freshwater crayfish.

  18. Fine structure of the spermatozoon in three species of Cambaridae (Arthropoda: Crustacea: Decapoda) Cambarus robustus, Orconectes propinquus and Orconectes rusticus: a comparative biometrical study

    PubMed Central

    Yazicioglu, Buket; Hamr, Přemek; Kozák, Pavel

    2016-01-01

    The ultrastructure of spermatozoa in three species of cambarid crayfish, Cambarus robustus, Orconectes propinquus, and Orconectes rusticus, were studied and compared with eight previously studied species from different crayfish families using morphological features and biometrical data. The ultrastructure of spermatozoa show a generally conserved pattern including an acrosome and nucleus in the anterior and posterior parts of the cell, respectively, radial arms that wrap around the nucleus, and the whole cell is enclosed by an extracellular capsule. The most outstanding morphological feature in spermatozoa of three studied cambarid crayfish is the crest-like protrusions in the anterior part of the acrosome that can be used as one of the features for distinguishing the members of this family. Results of biometrical data reveal that acrosome size in the representatives of Parastacidae are the smallest, while representatives of Astacidae show the biggest acrosome. The acrosome size in species belonging to Cambaridae occupy an intermediate position between the two other families of freshwater crayfish. In conclusion, a combination of morphological features and biometrical data of spermatozoa can help distinguishing different species of the freshwater crayfish. PMID:27635333

  19. Fine structure of the spermatozoon in three species of Cambaridae (Arthropoda: Crustacea: Decapoda) Cambarus robustus, Orconectes propinquus and Orconectes rusticus: a comparative biometrical study

    PubMed Central

    Yazicioglu, Buket; Hamr, Přemek; Kozák, Pavel

    2016-01-01

    The ultrastructure of spermatozoa in three species of cambarid crayfish, Cambarus robustus, Orconectes propinquus, and Orconectes rusticus, were studied and compared with eight previously studied species from different crayfish families using morphological features and biometrical data. The ultrastructure of spermatozoa show a generally conserved pattern including an acrosome and nucleus in the anterior and posterior parts of the cell, respectively, radial arms that wrap around the nucleus, and the whole cell is enclosed by an extracellular capsule. The most outstanding morphological feature in spermatozoa of three studied cambarid crayfish is the crest-like protrusions in the anterior part of the acrosome that can be used as one of the features for distinguishing the members of this family. Results of biometrical data reveal that acrosome size in the representatives of Parastacidae are the smallest, while representatives of Astacidae show the biggest acrosome. The acrosome size in species belonging to Cambaridae occupy an intermediate position between the two other families of freshwater crayfish. In conclusion, a combination of morphological features and biometrical data of spermatozoa can help distinguishing different species of the freshwater crayfish.

  20. Acute toxicity and accumulation of zinc in the crayfish, Orconectes virilis (Hagen)

    SciTech Connect

    Not Available

    1986-09-01

    Zinc produces acute toxicity to freshwater organisms over a range of concentrations from 90 to 58, 100..mu..g Zn/L; with the range of acute median effect concentrations being similar for freshwater fish and invertebrates. The capacity to regulate internal zinc concentrations in decapod crustaceans has been described. Studies with the crayfish Austropotambius pallipes suggested a relatively high degree of tolerance to zinc by this animal. The present study is designed to describe the toxicity of zinc to the crayfish Orconectes virilis over a 2-wk exposure period. In addition, whole animal and tissue analyses were performed on the test organisms and compared to previous results.

  1. Ontogenetic variation in food consumption of rusty crayfish (Orconectes rusticus) in a central New York stream

    USGS Publications Warehouse

    Johnson, J.H.; Nack, C.C.

    2010-01-01

    We examined feeding periodicity of three size groups of the rusty crayfish (Orconectes rusticus) at four-hour intervals over a 28-hour period during July in a headwater stream of the Susquehanna River drainage in central New York. Feeding activity was expressed as the ratio of stomach weight divided by the crayfish wet weight. The diel food consumption patterns of all three size groups of rusty crayfish (i.e., ??? 10 mm, 11-20 mm, and > 20 mm carapace length) were significantly different. Peak feeding of the smallest crayfish occurred during crepuscular periods. Food consumption of the intermediate size crayfish was highest at 2000 h, and feeding of large crayfish was consistently high from 1200 h to 0400 h. Feeding intensity of both small and intermediate size crayfish was highest when feeding intensity of large crayfsh was lowest. Ontogenetic differences in feeding periodicity may be associated with predation pressure from large rusty crayfish on smaller individuals.

  2. Ontogenetic Variation in Food Consumption of Rusty Crayfish (Orconectes rusticus) in a Central New York Stream

    USGS Publications Warehouse

    Johnson, James H.; Nack, Christopher C.

    2010-01-01

    We examined feeding periodicity of three size groups of the rusty crayfish (Orconectes rusticus) at four-hour intervals over a 28-hour period during July in a headwater stream of the Susquehanna River drainage in central New York. Feeding activity was expressed as the ratio of stomach weight divided by the crayfish wet weight. The diel food consumption patterns of all three size groups of rusty crayfish (i.e., ≤ 10 mm, 11–20 mm, and > 20 mm carapace length) were significantly different. Peak feeding of the smallest crayfish occurred during crepuscular periods. Food consumption of the intermediate size crayfish was highest at 2000 h, and feeding of large crayfish was consistently high from 1200 h to 0400 h. Feeding intensity of both small and intermediate size crayfish was highest when feeding intensity of large crayfsh was lowest. Ontogenetic differences in feeding periodicity may be associated with predation pressure from large rusty crayfish on smaller individuals.

  3. Population genetic structure of the crayfish,Orconectes juvenilis, in central Kentucky

    NASA Astrophysics Data System (ADS)

    Ziemba, R.; Reneer, D.; Buhay, J.; Crandall, K.

    2005-05-01

    Orconectes juvenilis is distributed throughout the Kentucky River basin and surrounding drainages. Little is known about the patterns of gene flow between populations of this species, but such information is critical for understanding patterns of diversification in the genus and in conservation planning for the group. We assessed sequence-level variation in the 16S region of mitochondrial DNA within and among fourteen populations of O. juvenilis. We also compared these data to sequences collected from two populations of O. cristavarius and one population of O. rusticus, two closely related species. The geographic distribution of haplotypes and patterns of mtDNA polymorphism are consistent with current isolation among some populations and suggest recent population growth, perhaps associated with geographic expansion. The data also suggest gene flow between morphologically divergent populations of O. juvenilis and O. cristavarius.

  4. Crayfish (Orconectes virilis) feeding on young lake trout (Salvelinus namaycush): effect of rock size

    USGS Publications Warehouse

    Savino, Jacqueline F.; Miller, John E.

    1991-01-01

    In laboratory studies, we quantified predation rates of crayfish (Orconectes virilis) on the eggs and sac fry of lake trout (Salvelinus namaycush) and a surrogate species, rainbow trout (Oncorhynchus mvkiss), dispersed among different sized substrates (bare bottom, gravel, cobble, large rocks). Predation was most severe when no rocks were present. Feeding rate then decreased as the substrate changed from large rocks to cobble to gravel. Crayfish predation rate did not change with prey type—rainbow trout and lake trout eggs or sac fry. Crayfish foraging in large tanks containing cobble averaged about two eggs or sac fry per day. In most instances, crayfish would have little impact on lake trout egg survival. Only in lake trout spawning grounds with relatively low egg densities, large crayfish populations, and cobble or large rock substrate, would crayfish be expected to have some impact on lake trout egg survival.

  5. A trematode parasite alters growth, feeding behavior, and demographic success of invasive rusty crayfish (Orconectes rusticus).

    PubMed

    Sargent, Lindsey W; Baldridge, Ashley K; Vega-Ross, Maraliz; Towle, Kevin M; Lodge, David M

    2014-07-01

    Nonindigenous species can cause major changes to community interactions and ecosystem processes. The strong impacts of these species are often attributed to their high demographic success. While the importance of enemy release in facilitating invasions has often been emphasized, few studies have addressed the role of parasites in the invasive range in controlling demographic success of potential invaders. Here we examine whether a trematode parasite (Microphallus spp.) can contribute to previously documented alternate states in the abundance of invasive rusty crayfish (Orconectes rusticus) in north temperate lakes in Wisconsin, USA. Microphallus infect O. rusticus after emerging from their first intermediate host, a hydrobiid snail. As previously documented, O. rusticus reduce densities of hydrobiid snails through direct predation and destruction of macrophyte habitat. Therefore, if Microphallus substantially reduce O. rusticus fitness, these parasites may reinforce a state of low crayfish abundance, and, at the other extreme, abundant crayfish may repress these parasites, reinforcing a state of high crayfish abundance. From samples collected from 109 sites in 16 lakes, we discovered (1) a positive relationship between crayfish infection intensity and hydrobiid snail abundance, (2) a negative relationship between parasite prevalence and crayfish abundance, and (3) a negative relationship between parasite prevalence and crayfish population growth. With experiments, we found that infection with Microphallus reduced foraging behavior and growth in O. rusticus, which may be the mechanisms responsible for the population reductions we observed. Overall results are consistent with the hypothesis that Microphallus contributes to alternate states in the abundance and impacts of O. rusticus.

  6. Effectiveness of two commercial rotenone formulations in the eradication of virile crayfish Orconectes virillis

    USGS Publications Warehouse

    Recsetar, Matthew S.; Bonar, Scott A.

    2015-01-01

    The virile or northern crayfish Orconectes virilis is an invasive species throughout much of the USA, damaging aquatic communities where it is introduced. Therefore, identification of effective methods for its eradication from areas in which it is unwanted is important. We studied the effectiveness of two commercial formulations of rotenone, Chem Fish Regular and CFT Legumine, for virile crayfish control. Although both formulations were effective for fish eradication, earlier observations by fisheries managers suggested that the relative effectiveness of the two formulations differs for crayfish. The only noteworthy difference between the formulations is that the former contains a synergist. In our first experiment, we tested each toxicant at the maximum labeled dosage (5 ppm) and found CFT Legumine to be 100% ineffective (0% mortality), while the Chem Fish Regular treatment resulted in 12.5% mortality. After we deemed Chem Fish Regular to be the only toxicant with any effectiveness against virile crayfish, we tested concentrations from 5 to 50 ppm and found 10 times the maximum labeled dosage (50 ppm rotenone) was needed to kill all virile crayfish. Because crayfish burrow and can leave water, and because 100% eradication is usually desired, rotenone applied at the labeled rates will not be effective for crayfish control. However, treating a body of water with CFT Legumine to eradicate invasive fish while leaving desirable crayfish unharmed is possible.

  7. Effects of Current Velocity, Particle Size, and Substrate Heterogeneity on Crayfish (Orconectes propinquus) Activity

    NASA Astrophysics Data System (ADS)

    Clark, J. M.; Kershner, M. W.

    2005-05-01

    The use of flow refugia (e.g., substrate) by lotic invertebrates often increases their likelihood of survival during flood events. Movement to potential refugia becomes risky as velocities increase, and the range of velocities that benthic invertebrates can withstand is variable. In this study, activity time and slip velocities of small [carapace length (CL)=10-20 mm] and large (CL=20-30 mm) Orconectes propinquus were measured in an artificial flume across ranges of current velocity and substrate heterogeneity. Particle sizes included small pebbles (16-32 mm), large pebbles (32-64 mm), and small cobble (64-128 mm). Water velocity was increased by 0.1 m/s increments from 0.1-1.5 m/s at 5-minute intervals or until the crayfish was dislodged from the substrate. As current velocity increased, the probability of slipping increased for all crayfish. Regardless of the degree of substrate heterogeneity, small crayfish held their position at higher velocities than large crayfish and were also less active. Slip rates were generally lower for both sizes as substrate heterogeneity increased. Essentially, the availability and probability of finding refugia increased with increased habitat heterogeneity and allowed crayfish to avoid being swept into the drift.

  8. Preliminary investigation of effects of sublethal acid exposure on maternal behavior in the Crayfish Orconectes virilis

    SciTech Connect

    France, R.L.

    1985-11-01

    The occurrence of crayfish inhabiting the littoral regions of many oligotrophic acid sensitive lakes makes these organisms vulnerable to spring pH decreases. Egg extrusion in Orconectes spp. found in south-central Ontario is generally synchronous and occurs during or slightly after ice melting in late April, a time at which these lakes receive between 36-77% of the year's export of H from their watersheds. To understand how a toxicant affects crayfish reproduction it is necessary that the maternal and embryonic responses to experimental perturbation be separated. In an acidified lake in the Experimental Lakes Area, northwestern Ontario, 6.9-16.9% of the egg-bearing females experienced partial mortality of their broods at pH 5.4-5.6. An ancillary experiment was undertaken here to determine if this egg mortality could be a result of low pH-induced behavioral modification of the maternal female, rather than direct acid toxicity to the developing eggs.

  9. Competition for food between crayfish (Orconectes virilis) and the slimy sculpin (Cottus cognatus)

    USGS Publications Warehouse

    Miller, John E.; Savino, Jacqueline F.; Neely, Robert K.

    1992-01-01

    Interspecific competition for a food resource (fish eggs) was examined in a laboratory setting between two common benthic organisms of the Great Lakes, the slimy sculpin (Cottus cognatus) and crayfish (Orconectes virilis). In monospecific tests, the median egg predation in aquarium microcosms ranged from 2.5 eggs/d for the sculpin to 3.0 eggs/d for the crayfish. In mixed-species tests, sculpin feeding rates were no different than in the monospecific tests. Feeding rates for crayfish, however, were significantly reduced by the presence of sculpin. In mixed-species treatments in which small refuges were included in the aquaria, crayfish predation of eggs was 50% less than in the monospecific tests, i.e., 1.5 eggs/d, and, crayfish went on 93% fewer excursions outside refuges, spent 94% less time outside refuges, and engaged in 83% fewer feeding bouts than sculpin (P≤ 0.05 for all comparisons). When no refuges were provided, crayfish ceased feeding (0 eggs/d). These results suggest the potential for an asymmetrical competitive interaction in a natural setting in which crayfish may be forced into a suboptimal diet by such an interaction with the slimy sculpin.

  10. Do antennule and aesthetasc structure in the crayfish Orconectes virilis correlate with flow habitat?

    PubMed

    Mead, Kristina S

    2008-12-01

    The local flow environment affects the shape of waterborne chemical signals through a variety of physical mechanisms and at several scales. Since crayfish rely on these chemical signals to extract information about predators, prey, and mates, one might expect the chemical sensors (aesthetascs) on crayfish antennules to be physically tuned to the presentation of chemical cues by the flow environment. This hypothesis was tested by comparing length, diameter, and spacing of antennules and aesthetascs among geographically distinct populations of Orconectes virilis. Crayfish were collected from the Chagrin river, Hebron hatchery, and Burt lake. In addition, antennules were sampled from 43 museum populations representing 12 lake, 10 creek, and 21 river populations from multiple states and river drainages. Mean velocities from the collection sites were either measured directly or calculated from United States Geological Survey (USGS) historical data. Structural parameters were measured using Scion Image software on Scanning electron microscope micrographs, and analyses of variance were performed using StatView. Structural parameters of aesthetascs were found to vary with flow environment. Aesthetascs from lake populations were inserted at a larger angle, extended out farther from the supporting antennule relative to the width of the antennule, and were more widely spaced than aesthetascs from creek, hatchery, and river populations.

  11. Mercury in the northern crayfish, Orconectes virilis (Hagen), in New England, USA.

    PubMed

    Pennuto, Chris M; Lane, Oksana P; Evers, David C; Taylor, Robert J; Loukmas, Jeff

    2005-03-01

    Biologists and policy makers continue to seek environmental correlates of mercury bioavailability in aquatic ecosystems. In this study, we assessed the effects of drainage basin, habitat type, size class, and sex on mercury concentrations in the northern crayfish, Orconectes virilis (Hagen). Drainage basin, habitat type, and size class had significant effects on mercury concentration in crayfish tail muscle even though animals from roughly half the sites examined had mean mercury values at or below expected background levels. The low observed mercury values in crayfish tail muscle indicate a low consumptive risk. Contrary to expectations, crayfish from brooks had higher mercury concentrations than animals from other habitat types, possibly as a result of point source contamination or varying diet compositions among habitats. We suggest that crayfish represent a good indicator of mercury bioavailability in aquatic ecosystems and provide a synthesis for lower food webs. Our understanding of mercury dynamics in lower food webs has been hindered by an under appreciation of the complexity in foraging habits of macroinvertebrates. Further studies focusing on benthos with well-understood life histories and foraging behavior are essential to improve our understanding of mercury transfer and bioavailability through aquatic systems.

  12. Habitat use and growth of the western painted crayfish Orconectes palmeri longimanus

    USGS Publications Warehouse

    Dyer, Joseph J.; Mouser, Joshua; Brewer, Shannon K.

    2016-01-01

    Identifying ontogenetic shifts in habitat use by aquatic organisms is necessary for improving conservation strategies; however, our ability to designate life stages based on surrogate metrics (i.e., length) is questionable without validation. This study identified growth patterns of age-0 western painted crayfish Orconectes palmeri longimanus (Faxon, 1898) reared in the laboratory, provided support for field-based designations of age-0 lengths, and identified microhabitat factors important to adult and juvenile presence from field collections. Two growth periods of a laboratory crayfish population were described using a broken line model: a rapid, early-growth period (weeks 2-20, slope = 0.81 ± 0.03SE), and a slower, late-growth period (weeks 22-50, slope = 0.13 ± 0.03SE). A smoothed curve was generated to represent the size distribution of juveniles from our laboratory population to determine the probability that an age-0 crayfish from our laboratory population had a carapace length (CL) similar to that found in previous field studies using onset of maturity (22.4 mm CL). We determined that the probability of the age-0 crayfish in our summer laboratory population exceeding 22.4 mm CL was 0.06. The threshold between the lower 0.95 and upper 0.05 probabilities was 22.9 mm CL, confirming previous field observations of onset at maturity. We used this threshold to identify juveniles and adults from our field collections, and found that both life stages were positively associated with coarse substrate and negatively associated with water depth. Adults, however, were negatively related to gravel, whereas juveniles showed a positive relationship. This result is reflective of the relationship between crayfish body size and refuge use within the interstitial spaces of substrates, whereby adult crayfish are unable to seek refuge in the small interstitial spaces of gravel.

  13. Acute Atrazine Exposure has Lasting Effects on Chemosensory Responses to Food Odors in Crayfish (Orconectes virilis).

    PubMed

    Belanger, Rachelle M; Mooney, Lauren N; Nguyen, Hung M; Abraham, Noor K; Peters, Tyler J; Kana, Maria A; May, Lauren A

    2016-02-01

    The herbicide atrazine is known to impact negatively olfactory-mediated behaviors in aquatic animals. We have shown that atrazine exposure has deleterious effects on olfactory-mediated behavioral responses to food odors in crayfish; however, recovery of chemosensory abilities post-atrazine exposure has not been investigated. We examined whether crayfish (Orconectes virilis) recovered chemosensory abilities after a 96-h exposure to sublethal, environmentally relevant concentrations of 80 ppb (µg/L) atrazine. Following treatment, we analyzed the ability of the crayfish to locate a food source using a Y-maze with one arm containing fish-flavored gelatin and the other containing unflavored gelatin. We compared the time spent in the food arm of the Y-maze, near the food source, as well as moving and walking speed of control and atrazine-treated crayfish. We also compared the number of crayfish that handled the food source and the amount of food consumed. Following 24-, 48-, and 72-h recovery periods in fresh water, behavioral trials were repeated to determine if there was any observable recovery of chemosensory-mediated behaviors. Atrazine-treated crayfish spent less time in the food arm, at the odor source, and were less successful at finding the food odor source than control crayfish for all times tested. Additionally, atrazine-treated crayfish consumed less fish-flavored than control crayfish; however, treatment did not affect locomotion. Overall, we found that crayfish are not able to recover chemosensory abilities 72 h post-atrazine exposure. Because crayfish rely heavily on their chemosensory abilities to acquire food, the negative impacts of atrazine exposure could affect population size in areas where atrazine is heavily applied.

  14. Effect of temperature on heavy metal toxicity to juvenile crayfish, Orconectes immunis (Hagen).

    PubMed

    Khan, M A Q; Ahmed, S A; Catalin, Bogdon; Khodadoust, A; Ajayi, Oluwaleke; Vaughn, Mark

    2006-10-01

    The acute toxicity of four selected heavy metals to juvenile crayfish Orconectes immunis (Hagen) (1-2 g wet body wt. each) at room temperature increased in the following order: cadmium (x3) < copper (x10) < zinc (x2) < lead. The toxicity of these metals to crayfish acclimated at 17, 20, 23/24, and 27 degrees C increased with temperature (by 7-20% between 20 and 24 degrees C and 14-26% between 20 and 27 degrees C) as judged by the lowering of LT(50) (time to kill 50% of test animals at a fixed concentration) values. A 4 degrees C rise in temperature (from 20 to 24 degrees C), which increased the toxicity of copper by about 7%, increased the rate of oxygen consumption by about 34%. Heavy metals inhibited the rate of oxygen consumption at all temperatures. In 20 degrees C-acclimated crayfish, copper caused about 17% inhibition of oxygen consumption compared to about 7-12% by other metals including the most toxic cadmium. A 3-4 degrees C rise in temperature tripled the inhibitory effect of copper (20%), cadmium and zinc (26 and 18%, respectively), but not of lead, on oxygen consumption. A 7 degrees C-rise in temperature (from 20 to 27 degrees C) increased the inhibitory effect of heavy metals, including lead, on oxygen consumption by up to 54% in the case of copper. The data indicate that rising global temperatures (currently 0.60 degrees C) associated with climate change can have the potential to increase the sensitivity of aquatic animals to heavy metals in their environment.

  15. Ecological effects of lead mining on Ozark streams: In-situ toxicity to woodland crayfish (Orconectes hylas)

    USGS Publications Warehouse

    Allert, A.L.; Fairchild, J.F.; DiStefano, R.J.; Schmitt, C.J.; Brumbaugh, W.G.; Besser, J.M.

    2009-01-01

    The Viburnum Trend mining district in southeast Missouri, USA is one of the largest producers of lead-zinc ore in the world. Previous stream surveys found evidence of increased metal exposure and reduced population densities of crayfish immediately downstream of mining sites. We conducted an in-situ 28-d exposure to assess toxicity of mining-derived metals to the woodland crayfish (Orconectes hylas). Crayfish survival and biomass were significantly lower at mining sites than at reference and downstream sites. Metal concentrations in water, detritus, macroinvertebrates, fish, and crayfish were significantly higher at mining sites, and were negatively correlated with caged crayfish survival. These results support previous field and laboratory studies that showed mining-derived metals negatively affect O. hylas populations in streams draining the Viburnum Trend, and that in-situ toxicity testing was a valuable tool for assessing the impacts of mining on crayfish populations.

  16. Differences Found in the Macroinvertebrate Community Composition in the Presence or Absence of the Invasive Alien Crayfish, Orconectes hylas.

    PubMed

    Freeland-Riggert, Brandye T; Cairns, Stefan H; Poulton, Barry C; Riggert, Christopher M

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities. PMID:26986207

  17. Evolution of invasive traits in nonindigenous species: increased survival and faster growth in invasive populations of rusty crayfish (Orconectes rusticus).

    PubMed

    Sargent, Lindsey W; Lodge, David M

    2014-09-01

    The importance of evolution in enhancing the invasiveness of species is not well understood, especially in animals. To evaluate evolution in crayfish invasions, we tested for differences in growth rate, survival, and response to predators between native and invaded range populations of rusty crayfish (Orconectes rusticus). We hypothesized that low conspecific densities during introductions into lakes would select for increased investment in growth and reproduction in invasive populations. We reared crayfish from both ranges in common garden experiments in lakes and mesocosms, the latter in which we also included treatments of predatory fish presence and food quality. In both lake and mesocosm experiments, O. rusticus from invasive populations had significantly faster growth rates and higher survival than individuals from the native range, especially in mesocosms where fish were present. There was no influence of within-range collection location on growth rate. Egg size was similar between ranges and did not affect crayfish growth. Our results, therefore, suggest that growth rate, which previous work has shown contributes to strong community-level impacts of this invasive species, has diverged since O. rusticus was introduced to the invaded range. This result highlights the need to consider evolutionary dynamics in invasive species mitigation strategies.

  18. Evolution of invasive traits in nonindigenous species: increased survival and faster growth in invasive populations of rusty crayfish (Orconectes rusticus)

    PubMed Central

    Sargent, Lindsey W; Lodge, David M

    2014-01-01

    The importance of evolution in enhancing the invasiveness of species is not well understood, especially in animals. To evaluate evolution in crayfish invasions, we tested for differences in growth rate, survival, and response to predators between native and invaded range populations of rusty crayfish (Orconectes rusticus). We hypothesized that low conspecific densities during introductions into lakes would select for increased investment in growth and reproduction in invasive populations. We reared crayfish from both ranges in common garden experiments in lakes and mesocosms, the latter in which we also included treatments of predatory fish presence and food quality. In both lake and mesocosm experiments, O. rusticus from invasive populations had significantly faster growth rates and higher survival than individuals from the native range, especially in mesocosms where fish were present. There was no influence of within-range collection location on growth rate. Egg size was similar between ranges and did not affect crayfish growth. Our results, therefore, suggest that growth rate, which previous work has shown contributes to strong community-level impacts of this invasive species, has diverged since O. rusticus was introduced to the invaded range. This result highlights the need to consider evolutionary dynamics in invasive species mitigation strategies. PMID:25469173

  19. Differences Found in the Macroinvertebrate Community Composition in the Presence or Absence of the Invasive Alien Crayfish, Orconectes hylas

    PubMed Central

    Freeland-Riggert, Brandye T.

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities. PMID:26986207

  20. Differences found in the macroinvertebrate community composition in the presence or absence of the invasive alien crayfish, Orconectes hylas

    USGS Publications Warehouse

    Freeland-Riggert, Brandye T.; Cairns, Stefan H.; Poulton, Barry C.; Riggert, Chris M.

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities.

  1. Differences Found in the Macroinvertebrate Community Composition in the Presence or Absence of the Invasive Alien Crayfish, Orconectes hylas.

    PubMed

    Freeland-Riggert, Brandye T; Cairns, Stefan H; Poulton, Barry C; Riggert, Christopher M

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities.

  2. Ionoregulatory responses of the crayfish Orconectes immunis to selenium in fresh water

    SciTech Connect

    Short, T.M.

    1983-01-01

    The purpose of this study was to investigate the effects of chronic exposure to sublethal concentrations of selenium on fluid and tissue electrolyte balance of the crayfish Orconcectes immunis. An ionic profile of O. immunis was obtained from measurements of hemolymph sodium, potassium, calcium, magnesium, and copper in several populations of crayfish in eastern Colorado. The bioassay portion of the study consisted of groups of crayfish maintained in reconstituted fresh water while exposed for 30 days to concentrations of 0.01 mg/liter, 0.10 mg/liter, or 1.00 mg/liter selenium as sodium selenite. Exposure to selenium resulted in various branchial histopathologies to include hypertrophy, necrosis, and sloughing of the cuticular membrane. Hemolymph potassium and copper, however, were significantly reduced in crayfish exposed for 10 days to 1.00 mg/liter selenium and 30 days to 0.10 mg/liter selenium. Copper appeared to be the more responsive to selenium toxicity with reductions of 47.4%-53.7% in hemolymph levels after exposure for 30 days to 1.00 mg/liter selenium. Selenium-induced changes in tissue ionic content (abdominal muscle and carapace) were most evident with respect to muscle levels of potassium and calcium. It is suggested that the observed alterations in fluid and tissue ionic content are largely in response to changes in concentration or electrochemical potential gradients brought about by selenium-induced disturbance of membrance permeability and ionic transport characteristics.

  3. Toxicological studies of cadmium and zinc on the crayfish Orconectes virilis

    SciTech Connect

    Mirenda, R.J.

    1985-01-01

    The acute toxicities of cadmium and of zinc to the crayfish Oronectes virilis were determined. Adult, intermolt crayfish were exposed to a series of concentrations of either cadmium or zinc for a two week period. Cadmium was found to be a cumulative poison to the crayfish; LC50 values decreased from 6.1 mg Cd/I for 96 hours to 0.7 mg Cd/I for two weeks. An incipient LC50 was also estimated to be 0.0604 mg Cd/I. Zinc was found to have a relatively low toxicity to O. virilis under the present exposure conditions. Whole animal and tissue analyses for cadmium or zinc were performed on the crayfish used in the acute toxicity tests. Whole animals concentrations both for cadmium and for zinc exhibited a linear relationship to exposure concentrations (r = 0.85 and 0.87, respectively). The gills had the highest concentrations (r = 0.85 and 0.87, respectively). The gills had the highest concentrations of cadmium and zinc, and displayed a linear relationship to exposure concentrations (r = 0.82 and 0.87 respectively). The hepatopancreas displayed a plateau in metal concentrations and is probably the main storage site for both metals in the crayfish. The relationship of cadmium concentration to exposure concentration in the antennal glands also showed linearity (r = 0.65), while zinc levels reached a steady state level. All the remaining tissues analyzed exhibited a plateau in metal concentration.

  4. Atrazine exposure affects the ability of crayfish (Orconectes rusticus) to localize a food odor source.

    PubMed

    Belanger, Rachelle M; Peters, Tyler J; Sabhapathy, Gita S; Khan, Sana; Katta, Juhi; Abraham, Noor K

    2015-05-01

    Environmental pollutants, found in aquatic ecosystems, have been shown to have an effect on olfactory-mediated behaviors including feeding, mate attraction, and other important social behaviors. Crayfish are polytrophic, meaning that they feed on and become prey for all levels of the aquatic food web as well as are also important for the transfer of energy between benthic and terrestrial food webs. Because crayfish are a keystone species, it is important to investigate any factors that may affect their population size. Crayfish are active at night and rely heavily on their sensory appendages (e.g., antennulues, maxillipeds, and pereopods) to localize food sources. In this experiment, we investigated the effects of atrazine (ATR) exposure on the chemosensory responses of male and female crayfish to food odors. We exposed crayfish to environmentally relevant, sublethal levels of ATR [80 ppb (µg/L)] for 72 h and then examined the behavioral responses of both ATR-treated and control crayfish to food odor delivered from one end of a test arena. We used Noldus Ethovision XT software to measure odor localization and locomotory behaviors of crayfish in response to food (fish) odor. We found that control crayfish spent more time in the proximal region of the test arena and at the odor source compared with ATR-treated crayfish. Furthermore, there were no differences in the time spent moving and not moving, total distance travelled in the tank, and walking speed (cm/s) when control and ATR-treated crayfish were compared. Overall, this indicates that acute ATR exposure alters chemosensory abilities of crayfish, whereas overall motor function remains unchanged.

  5. Multi-scale Factors Affecting the Distribution of the Critically Imperiled Crayfish, Orconectes williamsi, in the Upper White River Drainage of Missouri, USA

    NASA Astrophysics Data System (ADS)

    Westhoff, J. T.; Distefano, R. J.; Guyot, J. A.; McManus, M. G.

    2005-05-01

    Orconectes williamsi is known from only a few locations in the upper White River drainage of Missouri and Arkansas. We implemented a stratified (by stream order) random survey to sample for this crayfish in Missouri in 2003-04. Survey objectives were twofold. First, we estimated the overall proportion of stream order segments (segments of streams between points where stream order changes) in the drainage harboring O. williamsi, and then estimated the proportion of first, second and third (or larger) order stream segments harboring this crayfish. Second, we obtained means or ratio estimators (point estimates) and 95 % confidence limits (interval estimates) for 62 environmental variables and conducted overall contrasts of those estimates between segments that did and did not harbor O. williamsi. For significant overall contrasts, we then conducted contrasts partitioned by stream order. We detected O. williamsi at an overall proportion of 0.34 of 50 sampled segments, with no difference between first and second order stream segments. Variables exhibiting differences between segments that did and did not harbor O. williamsi included bankfull width:bankfull depth ratio, wetted width:wetted depth ratio, macrophyte abundance, elevation, and stream connectivity. Results will be used to drive future sampling and conservation efforts.

  6. Window contamination on Expose-R

    NASA Astrophysics Data System (ADS)

    Demets, R.; Bertrand, M.; Bolkhovitinov, A.; Bryson, K.; Colas, C.; Cottin, H.; Dettmann, J.; Ehrenfreund, P.; Elsaesser, A.; Jaramillo, E.; Lebert, M.; van Papendrecht, G.; Pereira, C.; Rohr, T.; Saiagh, K.

    2015-01-01

    Expose is a multi-user instrument for astrobiological and astrochemical experiments in space. Installed at the outer surface of the International Space Station, it enables investigators to study the impact of the open space environment on biological and biochemical test samples. Two Expose missions have been completed so far, designated as Expose-E (Rabbow et al. 2012) and Expose-R (Rabbow et al. this issue). One of the space-unique environmental factors offered by Expose is full-spectrum, ultraviolet (UV)-rich electromagnetic radiation from the Sun. This paper describes and analyses how on Expose-R, access of the test samples to Solar radiation degraded during space exposure in an unpredicted way. Several windows in front of the Sun-exposed test samples acquired a brown shade, resulting in a reduced transparency in visible light, UV and vacuum UV (VUV). Post-flight investigations revealed the discolouration to be caused by a homogenous film of cross-linked organic polymers at the inside of the windows. The chemical signature varied per sample carrier. No such films were found on windows from sealed, pressurized compartments, or on windows that had been kept out of the Sun. This suggests that volatile compounds originating from the interior of the Expose facility were cross-linked and photo-fixed by Solar irradiation at the rear side of the windows. The origin of the volatiles was not fully identified; most probably there was a variety of sources involved including the biological test samples, adhesives, plastics and printed circuit boards. The outer surface of the windows (pointing into space) was chemically impacted as well, with a probable effect on the transparency in VUV. The reported analysis of the window contamination on Expose-R is expected to help the interpretation of the scientific results and offers possibilities to mitigate this problem on future missions - in particular Expose-R2, the direct successor of Expose-R.

  7. Invasive crayfish and crayfish plague on the move: first detection of the plague agent Aphanomyces astaci in the Romanian Danube.

    PubMed

    Pârvulescu, Lucian; Schrimpf, Anne; Kozubíková, Eva; Cabanillas Resino, Sara; Vrålstad, Trude; Petrusek, Adam; Schulz, Ralf

    2012-02-17

    Native European crayfish, such as Astacus leptodactylus, are threatened, among other factors, by the crayfish plague agent Aphanomyces astaci, dispersed by invasive North American crayfish. Two of these invaders, Pacifastacus leniusculus and Orconectes limosus, have extended their distribution in the River Danube catchment; the latter was detected for the first time in Romania in 2008. We monitored, at monthly intervals for over 2 yr, occurrence of native A. leptodactylus and invasive O. limosus at 6 sites on the Romanian Danube and checked for the invasive species in 4 of its tributaries. Between January 2009 and March 2011, the relative abundances of O. limosus steadily increased with time, while the native A. leptodactylus dramatically decreased in abundance. O. limosus expanded downstream at a rate of ca. 15 km yr-1; in August 2011, it was already present in the upper 105 km of the Romanian Danube. An agent-specific real-time PCR analyses demonstrated the presence of A. astaci DNA in at least 32% of the analysed invasive (n = 71) and 41% of the native (n = 49) crayfish coexisting in the Danube. Furthermore, A. astaci was also detected in A. leptodactylus captured about 70 km downstream of the O. limosus invasion front (at the time of sampling). Assuming a steady rate of expansion, O. limosus may invade the sensitive Danube delta area in the mid-2060s, even without long-distance dispersal. The crayfish plague agent, however, may reach the delta substantially earlier, through dispersal downstream among populations of native crayfish.

  8. Copper accumulation in the crayfish (Orconectes rusticus)

    SciTech Connect

    Evans, M.L.

    1980-06-01

    The purpose of this study was to determine whether or not the crayfish, O. rusticus could fulfill Nehring's (1976) criteria for a good biological monitor of heavy metal pollution. Since there is some evidence that the cupric ion is the most toxic form of aqueous copper, crayfish-accumulated copper was compared to both total and cupric copper in the culture water.

  9. The thermal tolerance of crayfish could be estimated from respiratory electron transport system activity.

    PubMed

    Simčič, Tatjana; Pajk, Franja; Jaklič, Martina; Brancelj, Anton; Vrezec, Al

    2014-04-01

    Whether electron transport system (ETS) activity could be used as an estimator of crayfish thermal tolerance has been investigated experimentally. Food consumption rate, respiration rates in the air and water, the difference between energy consumption and respiration costs at a given temperature ('potential growth scope', PGS), and ETS activity of Orconectes limosus and Pacifastacus leniusculus were determined over a temperature range of 5-30°C. All concerned parameters were found to be temperature dependent. The significant correlation between ETS activity and PGS indicates that they respond similarly to temperature change. The regression analysis of ETS activity as an estimator of thermal tolerance at the mitochondrial level and PGS as an indicator of thermal tolerance at the organismic level showed the shift of optimum temperature ranges of ETS activity to the right for 2° in O. limosus and for 3° in P. leniusculus. Thus, lower estimated temperature optima and temperatures of optimum ranges of PGS compared to ETS activity could indicate higher thermal sensitivity at the organismic level than at a lower level of complexity (i.e. at the mitochondrial level). The response of ETS activity to temperature change, especially at lower and higher temperatures, indicates differences in the characteristics of the ETSs in O. limosus and P. leniusculus. O. limosus is less sensitive to high temperature. The significant correlation between PGS and ETS activity supports our assumption that ETS activity could be used for the rapid estimation of thermal tolerance in crayfish species. PMID:24679968

  10. EXPOSE-R on Mission on the ISS

    NASA Astrophysics Data System (ADS)

    Panitz, Corinna; Rabbow, Elke; Rettberg, Petra; Barczyk, Simon; Kloss, Maria; Reitz, Guenther

    Currently EXPOSE-R is on mission! This astrobiological exposure facility was accommodated at the universal workplace URM-D Zenith payload site, located outside the Russian Svezda Module of the International Space Station (ISS) by extravehicular activity (EVA) on March 10th 2009. It contains 3 trays accommodating 12 sample compartments with sample carriers in three levels either open to space vacuum or kept in a defined gas environment. In its 8 experiments of biological and chemical content, more than 1200 individual samples are exposed to solar ultraviolet (UV) radiations, vacuum, cosmic rays or extreme temperature variations. In their different experiments the involved scientists are studying the question of life's origin on Earth and the results of their experiments are contributing to different aspects of the evolution and distribution of life in the Universe. Additionally integrated into the EXPOSE-R facility are several dosimeters monitoring the ionising and the solar UV-radiation during the mission to deliver useful information to complement the sample analysis. In close cooperation with the DLR and the Technical University Munich (TUM), the Rheinisch -Westfülische Technischen Hochschule Aachen (RWTH Aachen) operates the experiment "Spores". a This is one of the 6 astrobiological experiments of the ROSE-Consortium" (Response of Or-ganisms to Space Environment) of the EXPOSE-R mission. In these experiments spores of bacteria, fungi and ferns are being over layered or mixed with meteorite material. The analysis of the effect of the space parameters on different biological endpoints of the spores of the mi-croorganism Bacillus subtilis will be performed after the retrieval of the experiment scheduled for the end of 2010. Parallel to the space mission an identical set of samples was accommodated into EXPOSE-R trays identical in construction to perform the Mission Ground Reference (MGR) Test. Currently this MGR Test is carried out in the Planetary and Space

  11. Welding tritium exposed stainless steel

    SciTech Connect

    Kanne, W.R. Jr.

    1994-11-01

    Stainless steels that are exposed to tritium become unweldable by conventional methods due to buildup of decay helium within the metal matrix. With longer service lives expected for tritium containment systems, methods for welding on tritium exposed material will become important for repair or modification of the systems. Solid-state resistance welding and low-penetration overlay welding have been shown to mitigate helium embrittlement cracking in tritium exposed 304 stainless steel. These processes can also be used on stainless steel containing helium from neutron irradiation, such as occurs in nuclear reactors.

  12. West Virginia crayfishes (Decapoda: Cambaridae): observations on distribution, natural history, and conservation

    USGS Publications Warehouse

    Loughman, Zachary J.; Simon, Thomas P.; Welsh, Stuart A.

    2009-01-01

    West Virginia's crayfishes have received moderate attention since publication of Jezerinac et al.'s (1995) monograph of the state fauna. Survey efforts were initiated over the summers of 2006 and 2007 to gather voucher material for the Indiana Biological Survey's Crustacean Collection. These collections have provided new information regarding the distribution, natural history, life history, taxonomy, and conservation status of Cambarus (Cambarus) carinirostris, C. (C.) bartonii cavatus, C. (C.) sciotensis, C. (Hiaticambarus) chasmodactylus, C. (H.) elkensis, C. (H.) longulus, C. (Jugicambarus) dubius, C. (Puncticambarus) robustus, Orconectes (Procericambarus) cristavarius, and O. (P.) rusticus. Orconectes (Faxonius) limosus has apparently been extirpated from West Virginia and should be removed from the state's list of extant crayfishes.

  13. West Virginia crayfishes (Decapoda: Cambaridae): observations on distribution, natural history, and conservation

    USGS Publications Warehouse

    Loughman, Zachary J.; Simon, Thomas P.; Welsh, Stuart A.

    2015-01-01

    West Virginia's crayfishes have received moderate attention since publication of Jezerinac et al.'s (1995) monograph of the state fauna. Survey efforts were initiated over the summers of 2006 and 2007 to gather voucher material for the Indiana Biological Survey's Crustacean Collection. These collections have provided new information regarding the distribution, natural history, life history, taxonomy, and conservation status of Cambarus (Cambarus) carinirostris, C. (C.) bartonii cavatus, C. (C.) sciotensis, C. (Hiaticambarus) chasmodactylus, C. (H.) elkensis, C. (H.) longulus, C. (Jugicambarus) dubius, C. (Puncticambarus) robustus, Orconectes (Procericambarus) cristavarius, and O. (P.) rusticus. Orconectes (Faxonius) limosus has apparently been extirpated from West Virginia and should be removed from the state's list of extant crayfishes.

  14. Brucellosis in Occupationally Exposed Groups

    PubMed Central

    Sajjan, Annapurna G.; Mohite, Shivajirao T.; Gajul, Shivali

    2016-01-01

    Introduction In India, high incidence of human brucellosis may be expected, as the conditions conducive for human brucellosis exist. Limited studies have been undertaken on human brucellosis especially in occupationally-exposed groups. Aim To estimate prevalence of anti-brucellar antibodies, evaluate the clinical manifestations, risk factors and Knowledge, Attitude and Practices (KAP) levels about brucellosis among occupationally exposed groups. Materials and Methods Blood samples were collected from 2337 occupationally exposed individuals. The serum samples were screened for the presence of anti-brucellar antibodies by Rose Bengal Plate Test (RBPT), Serum Agglutination Test (SAT) and 2-Mercaptoethanol test (2-ME). Clinical manifestations, risk factors and KAP levels were evaluated by personal interview using a structured questionnaire. Results Seroprevalence of brucellosis by RBPT, SAT and 2-ME test was 9.46%, 4.45% and 3.64 % respectively. Clinical symptoms resembling brucellosis were seen in 91 subjects. The major risk factors were animal exposure in veterinarians and abattoirs, both animal exposure and raw milk ingestion in farmers and shepherds, exposure to raw milk and its ingestion in dairy workers and exposure to Brucella culture in laboratory workers. Except laboratory workers, few veterinarians and dairy workers none had heard about brucellosis. KAP levels regarding brucellosis were too poor in all the groups except laboratory workers. Conclusion Brucellosis most of the times was missed or misdiagnosed. Regular screenings for brucellosis and awareness programmes to increase KAP levels are necessary to control brucellosis in occupationally exposed groups. PMID:27190804

  15. Survey of the crayfish plague pathogen presence in the Netherlands reveals a new Aphanomyces astaci carrier.

    PubMed

    Tilmans, M; Mrugała, A; Svoboda, J; Engelsma, M Y; Petie, M; Soes, D M; Nutbeam-Tuffs, S; Oidtmann, B; Roessink, I; Petrusek, A

    2014-07-01

    North American crayfish species as hosts for the crayfish plague pathogen Aphanomyces astaci contribute to the decline of native European crayfish populations. At least six American crayfish species have been reported in the Netherlands but the presence of this pathogenic oomycete with substantial conservational impact has not yet been confirmed in the country. We evaluated A. astaci prevalence in Dutch populations of six alien crustaceans using species-specific quantitative PCR. These included three confirmed crayfish carriers (Orconectes limosus, Pacifastacus leniusculus, Procambarus clarkii), two recently introduced but yet unstudied crayfish (Orconectes cf. virilis, Procambarus cf. acutus), and a catadromous crab Eriocheir sinensis. Moderate levels of infection were observed in some populations of O. limosus and P. leniusculus. Positive results were also obtained for E. sinensis and two Dutch populations of O. cf. virilis. English population of the latter species was also found infected, confirming this taxon as another A. astaci carrier in European waters. In contrast, Dutch P. clarkii seem only sporadically infected, and the pathogen was not yet detected in P. cf. acutus. Our study is the first confirmation of crayfish plague infections in the Netherlands and demonstrates substantial variation in A. astaci prevalence among potential hosts within a single region, a pattern possibly linked to their introduction history and coexistence.

  16. Advances in treating exposed fractures.

    PubMed

    Nogueira Giglio, Pedro; Fogaça Cristante, Alexandre; Ricardo Pécora, José; Partezani Helito, Camilo; Lei Munhoz Lima, Ana Lucia; Dos Santos Silva, Jorge

    2015-01-01

    The management of exposed fractures has been discussed since ancient times and remains of great interest to present-day orthopedics and traumatology. These injuries are still a challenge. Infection and nonunion are feared complications. Aspects of the diagnosis, classification and initial management are discussed here. Early administration of antibiotics, surgical cleaning and meticulous debridement are essential. The systemic conditions of patients with multiple trauma and the local conditions of the limb affected need to be taken into consideration. Early skeletal stabilization is necessary. Definitive fixation should be considered when possible and provisional fixation methods should be used when necessary. Early closure should be the aim, and flaps can be used for this purpose. PMID:26229904

  17. The "AMINO" experiment on expose

    NASA Astrophysics Data System (ADS)

    Barbier, B.; Coll, P.; Cottin, H.; Leach, S.; Maurel, M.-C.; Raulin, F.; Tepfer, D.; Brack, A.

    2002-11-01

    The "AMINO" experiment will take place, end of 2004, in the "EXPOSE" ESA device on the Columbus module outside the International Space Station (ISS). The objective of the "AMINO" experiment is mainly to study space chemistry in the solar system in relationship to the origin of life. The main goal is to support the hypothesis that extraterrestrial life-related compounds, ranging from bioorganic precursors to biological macromolecules, might have been delivered to the primitive Earth when associated with comets, meteorites or micrometeorites. Another aspect of organic chemistry in the solar system that one associated to Titan's environment. This domain is of primary interest for exobiology, due to the rich organic chemistry that occurs on Titan. The last interesting chemistry domain in the solar system concerns comets. Some cometary analogues and related compounds will be also studied.

  18. Advances in treating exposed fractures☆

    PubMed Central

    Nogueira Giglio, Pedro; Fogaça Cristante, Alexandre; Ricardo Pécora, José; Partezani Helito, Camilo; Lei Munhoz Lima, Ana Lucia; dos Santos Silva, Jorge

    2015-01-01

    The management of exposed fractures has been discussed since ancient times and remains of great interest to present-day orthopedics and traumatology. These injuries are still a challenge. Infection and nonunion are feared complications. Aspects of the diagnosis, classification and initial management are discussed here. Early administration of antibiotics, surgical cleaning and meticulous debridement are essential. The systemic conditions of patients with multiple trauma and the local conditions of the limb affected need to be taken into consideration. Early skeletal stabilization is necessary. Definitive fixation should be considered when possible and provisional fixation methods should be used when necessary. Early closure should be the aim, and flaps can be used for this purpose. PMID:26229904

  19. Advances in treating exposed fractures.

    PubMed

    Nogueira Giglio, Pedro; Fogaça Cristante, Alexandre; Ricardo Pécora, José; Partezani Helito, Camilo; Lei Munhoz Lima, Ana Lucia; Dos Santos Silva, Jorge

    2015-01-01

    The management of exposed fractures has been discussed since ancient times and remains of great interest to present-day orthopedics and traumatology. These injuries are still a challenge. Infection and nonunion are feared complications. Aspects of the diagnosis, classification and initial management are discussed here. Early administration of antibiotics, surgical cleaning and meticulous debridement are essential. The systemic conditions of patients with multiple trauma and the local conditions of the limb affected need to be taken into consideration. Early skeletal stabilization is necessary. Definitive fixation should be considered when possible and provisional fixation methods should be used when necessary. Early closure should be the aim, and flaps can be used for this purpose.

  20. Plasticity in fecundity highlights the females' importance in the spiny-cheek crayfish invasion mechanism.

    PubMed

    Pârvulescu, Lucian; Pîrvu, Mălina; Moroşan, Loredana-Giorgiana; Zaharia, Claudia

    2015-12-01

    Invasion is one of the most consequential phenomena affecting the distribution of native species. Few in number of species, European crayfish are losing the competition with introduced North American crayfish. The spiny-cheek crayfish, Orconectes limosus, is an outstanding example, successfully competing against the native narrow-clawed crayfish, Astacus leptodactylus. For four years, we collected data regarding crayfish occurrences, their relative abundance, and the structure of populations in the ongoing colonisation process of O. limosus in the lower Danube. The mature females of both invasive and indigenous crayfish species were analysed with respect to biometry and production of oocytes in relation to the dynamics of invasion. The interspecific comparisons showed no significant differences regarding body size, with an average of approximately 102 mm total length and 31 g wet weight for both species. However, the fecundity of the indigenous species was found to be constant throughout the investigated area, whereas the number of eggs produced by the invasive females was significantly increased at the active front of the invasion. The maximum number of ovarian eggs found was 887 and 1156 in the indigenous species and the invasive species, respectively. We propose the scenario that the invasive species, which carries the deadly crayfish plague, creates an ecological advantage by reducing the populations of indigenous crayfish. Subsequently, the invasive females opportunistically use the available resources to enhance their fecundity, resulting in the acute growth of populations. However, the long-term competitiveness and colonisation success of O. limosus still remain in question.

  1. [Drug Exposed Infants and Their Families.

    ERIC Educational Resources Information Center

    Fenichel, Emily, Ed.

    1992-01-01

    This bulletin issue addresses the theme of drug-exposed infants and the services required by these infants and their families. "Cocaine-Exposed Infants: Myths and Misunderstandings" (Barbara J. Myers and others) comments on the negative accounts of drug-exposed babies presented by mass media and reviews the mix of positive and negative findings…

  2. Layers Exposed at Polar Canyon

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This false-color subframe of an image from the High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter shows the north polar layered deposits at top and darker materials at bottom, exposed in a scarp at the head of Chasma Boreale, a large canyon eroded into the layered deposits.

    The polar layered deposits appear red because of dust mixed within them, but are ice-rich as indicated by previous observations. Water ice in the layered deposits is probably responsible for the pattern of fractures seen near the top of the scarp. The darker material below the layered deposits may have been deposited as sand dunes, as indicated by the crossbedding (truncation of curved lines) seen near the middle of the scarp. It appears that brighter, ice-rich layers were deposited between the dark dunes in places. Exposures such as these are useful in understanding recent climate variations that are likely recorded in the polar layered deposits.

    NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.

  3. Heat loss in exposed volunteers.

    PubMed

    English, M J; Farmer, C; Scott, W A

    1990-04-01

    Hypothermia is a common complication of major surgery and trauma. We studied this problem using Heat Flux Transducers to directly measure heat exchange between seven exposed volunteers and the environment. Heat exchange by radiation and convection was measured from the anterior chest wall and by conduction, between the back and a thermal mattress (CSZ, Blanketrol II). We determined the coefficients for: radiation = 6.6; convection = 8.3 square root of v; combined radiation and convection = 9.7; conductance = 41, all expressed in W/m2.degrees C. The clinical significance of these results is that heat loss, by radiation and convection alone, is 10 W/m2.degrees C. However, heat production under anaesthesia is only 40 W/m2, so a temperature gradient of greater than 4 degrees C between the skin and environment will cause more heat to be lost than is produced. The thermal mattress can supply 41 W/m2.degrees C, effectively doubling heat production.

  4. Preventing Alcohol-Exposed Pregnancies

    PubMed Central

    Floyd, R. Louise; Sobell, Mark; Velasquez, Mary M.; Ingersoll, Karen; Nettleman, Mary; Sobell, Linda; Mullen, Patricia Dolan; Ceperich, Sherry; von Sternberg, Kirk; Bolton, Burt; Skarpness, Bradley; Nagaraja, Jyothi

    2010-01-01

    Background Prenatal alcohol exposure is a leading preventable cause of birth defects and developmental disabilities in the United States. Design A randomized controlled trial (2002–2005; data analyzed 2005–2006) of a brief motivational intervention to reduce the risk of an alcohol-exposed pregnancy (AEP) in preconceptional women by focusing on both risk drinking and ineffective contraception use. Setting/Participants A total of 830 nonpregnant women, aged 18–44 years, and currently at risk for an AEP were recruited in six diverse settings in Florida, Texas, and Virginia. Combined settings had higher proportions of women at risk for AEP (12.5% overall) than in the general population (2%). Interventions Participants were randomized to receive information plus a brief motivational intervention (n=416) or to receive information only (n=414). The brief motivational intervention consisted of four counseling sessions and one contraception consultation and services visit. Main Outcome Measures Women consuming more than five drinks on any day or more than eight drinks per week on average, were considered risk drinkers; women who had intercourse without effective contraception were considered at risk of pregnancy. Reversing either or both risk conditions resulted in reduced risk of an AEP. Results Across the follow-up period, the odds ratios (ORs) of being at reduced risk for AEP were twofold greater in the intervention group: 3 months, 2.31 (95% confidence interval [CI]=1.69–3.20); 6 months, 2.15 (CI=1.52–3.06); 9 months, 2.11 (CI=1.47–3.03). Between-groups differences by time phase were 18.0%, 17.0%, and 14. 8%, respectively. Conclusions A brief motivational intervention can reduce the risk of an AEP. PMID:17218187

  5. Silent Victims: Children Exposed to Family Violence

    ERIC Educational Resources Information Center

    Kolar, Kathryn R.; Davey, Debrynda

    2007-01-01

    Annually an estimated 3 million or more children are exposed to acts of domestic violence between adults in their homes. These children are at risk for abuse themselves as well as other immediate and long-term problems, especially if they have been exposed to repeated episodes of domestic violence. Multiple behavioral manifestations, including…

  6. 3 EXPOSE Missions - overview and lessons learned

    NASA Astrophysics Data System (ADS)

    Rabbow, E.; Willnekcer, R.; Reitz, G.; Aman, A.; Bman, B.; Cman, C.

    2011-10-01

    The International Space Station ISS provides a variety of external research platforms for experiments aiming at the utilization of space parameters like vacuum, temperature oscillation and in particular extraterrestrial short wavelength UV and ionizing radiation which cannot be simulated accurately in the laboratory. Three Missions, two past and one upcoming, will be presented. A family of astrobiological experimental ESA facilities called "EXPOSE" were and will be accommodated on these outside exposure platforms: on one of the external balconies of the European Columbus Module (EXPOSE-E) and on the URM-D platform on the Russian Zvezda Module (EXPOSE-R and EXPOSE-R2). Exobiological and radiation experiments, exposing chemical, biological and dosimetric samples to the harsh space environment are - and will be - accommodated on these facilities to increase our knowledge on the origin, evolution and distribution of life, on Earth and possibly beyond. The biological experiments investigate resistance and adaptation of organisms like bacteria, Achaea, fungi, lichens, plant seeds and small animals like mosquito larvae to extreme environmental conditions and underlying mechanisms like DNA repair. The organic chemical experiments analyse chemical reactions triggered by the extraterrestrial environment, especially short wavelength UV radiation, to better understand prebiotic chemistry. The facility is optimized to allow exposure of biological specimen and material samples under a variety of conditions, using optical filter systems. Environmental parameters like temperature and radiation are regularly recorded and down linked by telemetry. Two long term missions named according to their facility - EXPOSE-E and EXPOSE-R - are completed and a third mission is planned and currently prepared. Operations of all three missions including sample accommodation are performed by DLR. An overview of the two completed missions will be given including lessons learned as well as an outlook

  7. Eryptosis in lead-exposed workers

    SciTech Connect

    Aguilar-Dorado, Itzel-Citlalli; Hernández, Gerardo; Quintanar-Escorza, Martha-Angelica; Maldonado-Vega, María; Rosas-Flores, Margarita; Calderón-Salinas, José-Víctor

    2014-12-01

    Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8 μg/dl) and non-exposed workers (4.2 μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca{sup 2+}]{sub i} and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (< 0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca{sup 2+}], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. - Graphical abstract: Fig. 1. (A) Blood lead concentration (PbB) and (B) phosphatidylserine externalization on erythrocyte membranes of non-lead exposed (□) and lead exposed workers (■). Values are mean ± SD. *Significantly different (P < 0.001). - Highlights: • Erythrocytes of lead exposed workers

  8. Dichroism of Photosensitive Pigment in Rhabdoms of the Crayfish Orconectes

    PubMed Central

    Waterman, Talbot H.; Fernández, Hector R.; Goldsmith, Timothy H.

    1969-01-01

    Microspectrophotometric measurements of isolated crayfish rhabdoms illuminated transversely show that their photosensitive absorption exhibits a dichroic ratio of 2 in situ. The major absorption axis matches the axial direction of the closely parallel microvilli comprising the receptor organelle. Since these microvilli are regularly oriented transversely in about 24 layers, with the axes of the microvilli at 90° in alternate layers, transverse illumination of a properly oriented rhabdom displays alternate dichroic and isotropic bands. Because all the microvilli from any one cell share the same orientation, the layers of microvilli constitute two sets of orthogonal polarization analyzers when illuminated along the normal visual axis. Furthermore, since the dichroic ratio is 2 and transverse absorption in isotropic bands is the same as that in the minor absorbing axis of dichroic bands, the simplest explanation of the analyzer action is that the absorbing dipoles of the chromophores, as in rod and cone outer segments, lie parallel to the membrane surface but are otherwise randomly oriented. The rhabdom's functional dichroism thus arises from its specific fine structural geometry. PMID:5806598

  9. Dichroism of photosensitive pigment in rhabdoms of the crayfish Orconectes.

    PubMed

    Waterman, T H; Fernández, H R; Goldsmith, T H

    1969-09-01

    Microspectrophotometric measurements of isolated crayfish rhabdoms illuminated transversely show that their photosensitive absorption exhibits a dichroic ratio of 2 in situ. The major absorption axis matches the axial direction of the closely parallel microvilli comprising the receptor organelle. Since these microvilli are regularly oriented transversely in about 24 layers, with the axes of the microvilli at 90 degrees in alternate layers, transverse illumination of a properly oriented rhabdom displays alternate dichroic and isotropic bands. Because all the microvilli from any one cell share the same orientation, the layers of microvilli constitute two sets of orthogonal polarization analyzers when illuminated along the normal visual axis. Furthermore, since the dichroic ratio is 2 and transverse absorption in isotropic bands is the same as that in the minor absorbing axis of dichroic bands, the simplest explanation of the analyzer action is that the absorbing dipoles of the chromophores, as in rod and cone outer segments, lie parallel to the membrane surface but are otherwise randomly oriented. The rhabdom's functional dichroism thus arises from its specific fine structural geometry.

  10. Assessment of low ABSPI among arsenic exposed and non-exposed populations: a pilot study.

    PubMed

    Khan, Manzurul Haque; Sarkar, Sudipta; Khan, Nasreen; Sarwar, A F M; Ahmad, S Akhtar

    2010-04-01

    This cross-sectional study was carried out to assess and compare Ankle Brachial Systolic Pressure Index (ABSPI) amongst 120 arsenic exposed and 120 non-exposed populations of Samta village in Bangladesh. Abnormal ABSPI was more prevalent in arsenic exposed (13.3%) than in non-exposed (2.5%) group. The prevalence of abnormal ABSPI for respondents when adjusted for age, sex, BMI, blood pressure status and diabetic status, the prevalence remain significantly different. The findings suggest that those exposed to arsenic have increased chance of having abnormal ABSP and hence increased chance of peripheral arterial disease in Bangladesh.

  11. Helping Children Exposed to Domestic Violence

    MedlinePlus

    ... withdrawal Depression or anxiety Loss of interest in school, friends or other things they enjoyed in the past Children and adolescents exposed to domestic violence should be evaluated by a trained mental health ...

  12. Field observations of intraspecific agonistic behavior of two crayfish species, Orconectes rusticus and Orconectes virilis, in different habitats.

    PubMed

    Bergman, Daniel A; Moore, Paul A

    2003-08-01

    Agonistic behavior is a fundamental aspect of ecological theories on resource acquisition and sexual selection. Crustaceans are exemplary models for agonistic behavior within the laboratory, but agonistic behavior in natural habitats is often neglected. Laboratory studies do not achieve the same ecological realism as field studies. In an attempt to connect laboratory results to field data and investigate how habitat structure affects agonistic interactions, the nocturnal behavior of two crayfish species was observed by scuba diving and snorkeling in two northern Michigan lakes. Intraspecific agonistic interactions were analyzed in three habitats: two food resources-macrophytes and detritus-and one sheltered habitat. The overall observations reinforce the concept that resources influence agonistic bouts. Fights in the presence of shelters were longer and more intense, suggesting that shelters have a higher perceived value than food resources. Fights in the presence of detritus patches had higher average intensities and ended with more tailflips away from an opponent, suggesting that detritus was a more valuable food resource than macrophytes. In addition, observations of aggressive behavior within a natural setting can add validity to laboratory studies. When fights in nature are compared with laboratory fights, those in nature are shorter, less intense, and less likely to end with a tailflip, but do show the fundamental fight dynamics associated with laboratory studies. Extrinsic and intrinsic factors affect intraspecific aggression in many ways, and both should always be recognized as having the potential to alter agonistic behavior.

  13. The astrobiological mission EXPOSE-R on board of the International Space Station

    NASA Astrophysics Data System (ADS)

    Rabbow, Elke; Rettberg, Petra; Barczyk, Simon; Bohmeier, Maria; Parpart, Andre; Panitz, Corinna; Horneck, Gerda; Burfeindt, Jürgen; Molter, Ferdinand; Jaramillo, Esther; Pereira, Carlos; Weiß, Peter; Willnecker, Rainer; Demets, René; Dettmann, Jan

    2015-01-01

    EXPOSE-R flew as the second of the European Space Agency (ESA) EXPOSE multi-user facilities on the International Space Station. During the mission on the external URM-D platform of the Zvezda service module, samples of eight international astrobiology experiments selected by ESA and one Russian guest experiment were exposed to low Earth orbit space parameters from March 10th, 2009 to January 21st, 2011. EXPOSE-R accommodated a total of 1220 samples for exposure to selected space conditions and combinations, including space vacuum, temperature cycles through 273 K, cosmic radiation, solar electromagnetic radiation at >110, >170 or >200 nm at various fluences up to GJ m-2. Samples ranged from chemical compounds via unicellular organisms and multicellular mosquito larvae and seeds to passive radiation dosimeters. Additionally, one active radiation measurement instrument was accommodated on EXPOSE-R and commanded from ground in accordance with the facility itself. Data on ultraviolet radiation, cosmic radiation and temperature were measured every 10 s and downlinked by telemetry and data carrier every few months. The EXPOSE-R trays and samples returned to Earth on March 9th, 2011 with Shuttle flight, Space Transportation System (STS)-133/ULF 5, Discovery, after successful total mission duration of 27 months in space. The samples were analysed in the individual investigators laboratories. A parallel Mission Ground Reference experiment was performed on ground with a parallel set of hardware and samples under simulated space conditions following to the data transmitted from the flight mission.

  14. Hormonal Perturbations in Occupationally Exposed Nickel Workers

    PubMed Central

    Beshir, Safia; Ibrahim, Khadiga Salah; Shaheen, Weam; Shahy, Eman M.

    2016-01-01

    BACKGROUND: Nickel exposure is recognized as an endocrine disruptor because of its adverse effects on reproduction. AIM: This study was designed to investigate the possible testiculo-hormonal perturbations on workers occupationally exposed to nickel and to assess its effects on human male sexual function. METHODS: Cross-sectional comparative study, comprising 105 electroplating male non-smoker, non-alcoholic workers exposed to soluble nickel and 60 controls was done. Serum luteinizing hormone, follicle stimulating hormone, testosterone levels and urinary nickel concentrations were determined for the studied groups. RESULTS: Serum luteinizing hormone, follicle stimulating hormone, urinary nickel and the simultaneous incidence of more than one sexual disorder were significantly higher in the exposed workers compared to controls. The occurrence of various types of sexual disorders (decreased libido, impotence and premature ejaculation) in the exposed workers was 9.5, 5.1 and 4.4 folds respectively than the controls. CONCLUSIONS: Exposure to nickel produces possible testiculo-hormonal perturbations in those exposed workers. PMID:27335607

  15. Developmental trajectories of cocaine-and-other-drug-exposed and non-cocaine-exposed children.

    PubMed

    Mayes, Linda C; Cicchetti, Domenic; Acharyya, Suddhasatta; Zhang, Heping

    2003-10-01

    Few data are available concerning the trajectories of mental and motor development across time for cocaine-exposed children compared with others. Findings are presented from individual group curve analyses of the mental and motor development measured by the Bayley Scales of Infant Development-II (BSID-II) on repeated visits from 3 through 36 months of a group of prenatally cocaine-and-other-drug-exposed children (n = 265) compared with those exposed to no drugs (n = 129) or no-cocaine-but-other-drugs (n = 66), including alcohol and/or tobacco. Across time, there was a general decline in motor performance but cocaine-exposed-infants showed a trend toward a greater decrease than children in the other two comparison groups. For mental performance, there was also a decline across age but only through 24 months and no differences in the trajectory of the cocaine-exposed group compared to the other two. And, across all assessment ages, cocaine-exposed-infants showed lower BSID-II mental performance compared to both non-drug and non-cocaine-exposed children. Results suggest that prenatally cocaine-exposed children show delayed developmental indices, particularly in their mental performance, but their trajectories across time are similar to those from impoverished, non-cocaine-exposed groups. PMID:14578693

  16. The Expose-R2 mission: astrobiology and astrochemistry in low Earth orbit

    NASA Astrophysics Data System (ADS)

    Demets, René

    EXPOSE is an exposure platform developed by ESA which permits scientists to install test samples for 1 to 2 years at the outer surface of the ISS. In that way, the impact of the open space environment on biological and biochemical sample materials can be explored. This environment, featuring full-spectrum solar light, near-vacuum, cosmic radiation, wide temperature variations and near-weightlessness, is impossible to reproduce in its entirety in the lab. As such, EXPOSE offers astrochemists and astrobiologists a chance to acquire novel scientific data. Astrochemists are interested in Low Earth Orbit conditions due to the fact that photochemistry in space is quite different from photochemistry on Earth, where the high-energy UV compounds of the solar spectrum are filtered away by our atmosphere. As for the astro biologists, EXPOSE offers an attractive opportunity to expand earlier results obtained during short-duration LEO flights, which have shown that particular microbes and, amazingly, even some multi-cellular macroscopic organisms were able to cope with a two-week exposure to space. The open space environment, often described as harsh and hostile, can apparently be tolerated by some robust inhabitants of our Earth - unprotected, in the absence of a space suit! The first mission of EXPOSE, as an external payload on the European Columbus module, happened during 2008-2009 with the test samples provided by five separate research teams. Three additional teams were involved in the monitoring of space environment. The results were published collectively in 2012 in a special issue of the monthly journal Astrobiology. Several organisms survived, having spent 1.5 years in space. The second mission was called EXPOSE-R, the R referring to ‘Russian segment’, the location where the EXPOSE instrument was installed this time. The EXPOSE-R mission took place in 2009-2011, ten science teams were involved. The publication of the results, again as a collection, is currently in

  17. Interviews with Children Exposed to Violence

    ERIC Educational Resources Information Center

    Eriksson, Maria; Nasman, Elisabet

    2012-01-01

    The aim of this article is to show how research practices may simultaneously follow principles of children's citizenship rights to participation and principles of protection and support when children exposed to violence are informants. The article focuses upon organisation of interview processes and interactions between adult researchers and child…

  18. Exposing the Mathematical Wizard: Approximating Trigonometric Functions

    ERIC Educational Resources Information Center

    Gordon, Sheldon P.

    2011-01-01

    For almost all students, what happens when they push buttons on their calculators is essentially magic, and the techniques used are seemingly pure wizardry. In this article, the author draws back the curtain to expose some of the mathematics behind computational wizardry and introduces some fundamental ideas that are accessible to precalculus…

  19. Cocaine Babies: Florida's Substance-Exposed Youth.

    ERIC Educational Resources Information Center

    Harpring, Jayme

    This report is designed to provide Florida's school personnel with assistance in working with students prenatally exposed to cocaine or other toxic substances. The report offers background data, practical strategies for teaching and learning, and resources for networking. The first chapter outlines statistics on the incidence of the problem of…

  20. Rural Canadian Youth Exposed to Physical Violence

    ERIC Educational Resources Information Center

    Laye, Adele M.; Mykota, David B.

    2014-01-01

    Exposure to physical violence is an unfortunate reality for many Canadian youth as it is associated with numerous negative psychosocial effects. The study aims to assist in understanding resilience in rural Canadian youth exposed to physical violence. This is accomplished by identifying the importance of protective factors, as measured by the…

  1. Electroencephalographic findings in workers exposed to benzene.

    PubMed

    Kellerová, V

    1985-01-01

    Preventive EEG examination was carried out in 40 workers significantly exposed to benzene. The EEG findings were compared with those of a control group of 48 healthy persons, a group of 110 workers significantly exposed to toluene and xylene and a group of 236 workers exposed to vinyl chloride. The individuals exposed to benzene exhibited 22.5% of abnormal and 45% threshold findings, the abnormalities being episodic, diffuse or a combination of the two. The effect of benzene entailed a frequent (32.5%) occurrence of a characteristic frequency lability. Sleep phenomena were found in a total of 60% cases (37.5% cases reached stage 1 B3 while 15% reached stage 2 according to Roth [14]). The rapid onset of deeper sleep stages (in 30% cases) is considered typical for benzene exposure. The photic driving response often had an extended frequency range (a total of 61.1%, to beta frequencies only in 30.55%, to both beta and theta frequencies also in 30.55% of cases). The different EEG features characteristic of the neurotoxic action of various types of organic solvents make possible a more efficient diagnostics of the effects of these chemicals on the CNS. PMID:4086812

  2. Expose Mechanical Engineering Students to Biomechanics Topics

    ERIC Educational Resources Information Center

    Shen, Hui

    2011-01-01

    To adapt the focus of engineering education to emerging new industries and technologies nationwide and in the local area, a biomechanics module has been developed and incorporated into a mechanical engineering technical elective course to expose mechanical engineering students at ONU (Ohio Northern University) to the biomedical engineering topics.…

  3. Surface contamination on LDEF exposed materials

    NASA Technical Reports Server (NTRS)

    Hemminger, Carol S.

    1992-01-01

    X-ray photoelectron spectroscopy (XPS) has been used to study the surface composition and chemistry of Long Duration Exposure Facility (LDEF) exposed materials including silvered Teflon (Ag/FEP), Kapton, S13GLO paint, quartz crystal monitors (QCM's), carbon fiber/organic matrix composites, and carbon fiber/Al Alloy composites. In each set of samples, silicones were the major contributors to the molecular film accumulated on the LDEF exposed surfaces. All surfaces analyzed have been contaminated with Si, O, and C; most have low levels (less than 1 atom percent) of N, S, and F. Occasionally observed contaminants included Cl, Na, K, P, and various metals. Orange/brown discoloration observed near vent slots in some Ag/FEP blankets were higher in carbon, sulfur, and nitrogen relative to other contamination types. The source of contamination has not been identified, but amine/amide functionalities were detected. It is probable that this same source of contamination account for the low levels of sulfur and nitrogen observed on most LDEF exposed surfaces. XPS, which probes 50 to 100 A in depth, detected the major sample components underneath the contaminant film in every analysis. This probably indicates that the contaminant overlayer is patchy, with significant areas covered by less that 100 A of molecular film. Energy dispersive x-ray spectroscopy (EDS) of LDEF exposed surfaces during secondary electron microscopy (SEM) of the samples confirmed contamination of the surfaces with Si and O. In general, particulates were not observed to develop from the contaminant overlayer on the exposed LDEF material surfaces. However, many SiO2 submicron particles were seen on a masked edge of an Ag/FEP blanket. In some cases such as the carbon fiber/organic matrix composites, interpretation of the contamination data was hindered by the lack of good laboratory controls. Examination of laboratory controls for the carbon fiber/Al alloy composites showed that preflight contamination was

  4. The EXPOSE-R Experiment ROSE-3 SPORES in artificial meteorites

    NASA Astrophysics Data System (ADS)

    Panitz, C.; Horneck, G.; Rabbow, E.; Rettberg, P.; Reitz, G.

    2011-10-01

    In the conducted experiment, spores of bacteria, fungi and ferns, especially adapted to survive extreme conditions, were either solely or embedded in artificial meteorites exposed to space environment in the ESA facility EXPOSE-R for 22 months (10.03.2009-21.02.2011). The experiment will provide experimental clues to the question whether meteorite material offers enough protection against the harsh environment of space for spores to survive a long-term stay in space. This question has received increased attention since the discovery of Martian meteorites has provided evidence that rocks can be transported from one planet to another in our solar

  5. CT assessment of silicosis in exposed workers.

    PubMed

    Bégin, R; Bergeron, D; Samson, L; Boctor, M; Cantin, A

    1987-03-01

    For evaluation of the clinical usefulness of CT of the thorax in workers exposed to silica, 58 workers with long-term exposure to silica in the granite and foundry industries of the Eastern Townships of Quebec were examined. CT scans were compared with standard posteroanterior chest radiographs by using the International Labour Office 1980 grading system for silicosis. Six areas of the lung in each patient were assessed by both techniques for profusion (number) of opacities (small nodules), coalescence, and the presence of large opacities. CT scans and chest radiographs yielded similar average scores for detection of opacities. CT identified significantly more coalescence and large opacities in patients with simple silicosis. In patients with complicated silicosis, CT results were comparable with those of chest radiographs. CT of the thorax in workers exposed to silica does not identify more patients with minimal parenchymal disease, but it does detect earlier changes of coalescence.

  6. Children exposed to war/terrorism.

    PubMed

    Shaw, Jon A

    2003-12-01

    This paper reviews the prevalence of psychological morbidities in children who have been exposed to war-related traumas or terrorism as well as the diversity of war-related casualties and their associated psychological responses. The psychological responses to war-related stressors are categorized as (1) little or no reaction, (2) acute emotional and behavioral effects, and (3) long-term effects. Specific categories of war-related casualties discussed include refugee status, traumatic bereavement, effects of parental absence, and child soldiers. Psychological responses associated with terrorism and bioterrorism are presented. Lastly, mediators of the psychological response to war-related stressors are discussed, to include exposure effects, gender effects, parental, family and social factors, and child-specific factors. Children exposed to war-related stressors experience a spectrum of psychological morbidities including posttraumatic stress symptomatology, mood disorders, externalizing and disruptive behaviors, and somatic symptoms determined by exposure dose effect. Specific questions for future research are identified.

  7. Exposed proteins of the Schistosoma japonicum tegument.

    PubMed

    Mulvenna, Jason; Moertel, Luke; Jones, Malcolm K; Nawaratna, Sujeevi; Lovas, Erica M; Gobert, Geoffrey N; Colgrave, Michelle; Jones, Alun; Loukas, Alex; McManus, Donald P

    2010-04-01

    The ability of the mammalian blood fluke Schistosoma japonicum to survive in the inhospitable environment of the mammalian bloodstream can be attributed, at least in part, to its host-exposed outer surface, called the tegument. The tegument is a dynamic organ and is involved in nutrition, immune evasion and modulation, excretion, osmoregulation and signal transduction. Given its importance for parasite survival, proteins exposed to the host at the surface of the tegument are ideal targets for the development of vaccines and drugs. By biotinylating live adult worms and using a combination of OFFGEL electrophoresis and tandem mass spectrometry 54 proteins were identified as putatively host-exposed in S. japonicum. These included glucose transport proteins, an amino permease, a leucine aminopeptidase and a range of transporters, heat shock proteins and novel immune-active proteins. Members of the tetraspanin protein family and a homologue of Sm 29, a tegument membrane protein from Schistosoma mansoni, both effective vaccine antigens in S. mansoni, were also identified. The fate of labelled surface proteins was monitored over time using electron microscopy and revealed that biotinylated proteins were rapidly internalised from the surface of the tegument and trafficked into the cytoplasmic bridges that connect the distal cytoplasm of the tegument to the underlying cell bodies. The results reported herein dramatically increase the number of S. japonicum proteins known to be exposed to the host and, hence, those of interest as therapeutic targets. The ability of the parasite to rapidly internalise proteins at its surface has implications for the development of vaccines and may explain how these parasites are able to avoid the host immune system for long periods of time. PMID:19853607

  8. Biochemical markers in butadiene-exposed workers

    SciTech Connect

    Bechtold, W.E.; Hayes, R.B.; Thornton-Manning, J.R.; Henderson, R.F.

    1994-11-01

    1,3-Butadiene (BD) is used to manufacture a wide range of polymers and copolymers including styrene-butadiene rubber, polybutadiene, and acrylonitrile-butadiene-syrene resins. The carcinogenicity of BD has been determined in life-span inhalation studies in both Sprague-Dawley rats and B6C3F{sub 1} mice. Results suggest a marked species difference in the carcinogenic effects of BD. For example, female mice exposed to as low as 6.25 ppm BD exhibited increased alveolar/bronchiolar neoplasms. In contrast, BD was only a weak carcinogen in Sprague-Dawley rats. Rats were observed to have an increase only in mammary tumors after exposure to 1000 ppm. A biochemical study of highly exposed BD workers and unexposed controls is providing valuable information on BD metabolism in humans, and how this relates to the development of intermediate biologic effects. A group of heavily exposed workers were identified in a BD production facility in China. The purpose of this paper is to report the initial results from the sampling trip in the first quarter of 1994.

  9. Genetic Alterations in Pesticide Exposed Bolivian Farmers

    PubMed Central

    Jørs, Erik; Gonzáles, Ana Rosa; Ascarrunz, Maria Eugenia; Tirado, Noemi; Takahashi, Catharina; Lafuente, Erika; Dos Santos, Raquel A; Bailon, Natalia; Cervantes, Rafael; O, Huici; Bælum, Jesper; Lander., Flemming

    2007-01-01

    Background Pesticides are of concern in Bolivia because of increasing use. Frequent intoxications have been demonstrated due to use of very toxic pesticides, insufficient control of distribution and sale and little knowledge among farmers of protective measures and hygienic procedures. Method Questionnaires were applied and blood tests taken from 81 volunteers from La Paz County, of whom 48 were pesticide exposed farmers and 33 non-exposed controls. Sixty males and 21 females participated with a mean age of 37.3 years (range 17–76). Data of exposure and possible genetic damage were collected and evaluated by well known statistical methods, controlling for relevant confounders. To measure genetic damage chromosomal aberrations and the comet assay analysis were performed. Results Pesticide exposed farmers had a higher degree of genetic damage compared to the control group. The number of chromosomal aberrations increased with the intensity of pesticide exposure. Females had a lower number of chromosomal aberrations than males, and people living at altitudes above 2500 metres seemed to exhibit more DNA damage measured by the comet assay. Conclusions Bolivian farmers showed signs of genotoxic damage, probably related to exposure to pesticides. Due to the potentially negative long term health effects of genetic damage on reproduction and the development of cancer, preventive measures are recommended. Effective control with imports and sales, banning of the most toxic pesticides, education and information are possible measures, which could help preventing the negative effects of pesticides on human health and the environment. PMID:19662224

  10. Aphid Acceptance of Barley Exposed to Volatile Phytochemicals Differs Between Plants Exposed in Daylight and Darkness

    PubMed Central

    Glinwood, Robert; Gradin, Therese; Karpinska, Barbara; Ahmed, Elham; Jonsson, Llisbeth

    2007-01-01

    It is well known that volatile cues from damaged plants may induce resistance in neighboring plants. Much less is known about the effects of volatile interaction between undamaged plants. In this study, barley plants, Hordeum vulgare cv. Kara, were exposed to volatiles from undamaged plants of barley cv. Alva or thistle Cirsium vulgare, and to the volatile phytochemicals, methyl salicylate or methyl jasmonate. Exposures were made either during natural daylight or darkness. Acceptance of exposed plants by the aphid Rhopalosiphum padi was assessed, as well as the expression of putative marker genes for the different treatments. Aphid acceptance of plants exposed to either barley or C. vulgare was significantly reduced, and an effect of the volatiles from undamaged plants was confirmed by the induction of pathogenesis-related protein, PR1a in exposed plants. However the effect on aphid acceptance was seen only when plants were exposed during darkness, whereas PR1a was induced only after treatment during daylight. Aphid acceptance of plants exposed to either methyl salicylate or methyl jasmonate was significantly reduced, but only when plants were exposed to the chemicals during daylight. AOS2 (allene oxide synthase) was induced by methyl jasmonate and BCI-4 (barley chemical inducible gene-4) by methyl salicylate in both daylight and darkness. It is concluded that (a) the effects on aphids of exposing barley to volatile phytochemicals was influenced by the presence or absence of light and (b) the response of barley to methyl salicylate/methyl jasmonate and to volatiles from undamaged plants differed at the gene and herbivore level. PMID:19516995

  11. Fibrosis biomarkers in workers exposed to MWCNTs.

    PubMed

    Fatkhutdinova, Liliya M; Khaliullin, Timur O; Vasil'yeva, Olga L; Zalyalov, Ramil R; Mustafin, Ilshat G; Kisin, Elena R; Birch, M Eileen; Yanamala, Naveena; Shvedova, Anna A

    2016-05-15

    Multi-walled carbon nanotubes (MWCNT) with their unique physico-chemical properties offer numerous technological advantages and are projected to drive the next generation of manufacturing growth. As MWCNT have already found utility in different industries including construction, engineering, energy production, space exploration and biomedicine, large quantities of MWCNT may reach the environment and inadvertently lead to human exposure. This necessitates the urgent assessment of their potential health effects in humans. The current study was carried out at NanotechCenter Ltd. Enterprise (Tambov, Russia) where large-scale manufacturing of MWCNT along with relatively high occupational exposure levels was reported. The goal of this small cross-sectional study was to evaluate potential biomarkers during occupational exposure to MWCNT. All air samples were collected at the workplaces from both specific areas and personal breathing zones using filter-based devices to quantitate elemental carbon and perform particle analysis by TEM. Biological fluids of nasal lavage, induced sputum and blood serum were obtained from MWCNT-exposed and non-exposed workers for assessment of inflammatory and fibrotic markers. It was found that exposure to MWCNTs caused significant increase in IL-1β, IL6, TNF-α, inflammatory cytokines and KL-6, a serological biomarker for interstitial lung disease in collected sputum samples. Moreover, the level of TGF-β1 was increased in serum obtained from young exposed workers. Overall, the results from this study revealed accumulation of inflammatory and fibrotic biomarkers in biofluids of workers manufacturing MWCNTs. Therefore, the biomarkers analyzed should be considered for the assessment of health effects of occupational exposure to MWCNT in cross-sectional epidemiological studies. PMID:26902652

  12. Physical examinations of workers exposed to trichlorotrifluoroethane.

    NASA Technical Reports Server (NTRS)

    Imbus, H. R.; Adkins, C.

    1972-01-01

    A group of 50 workers, exposed for an average of 2.77 years in an environment, samples of which contained from 46 to 4700 ppm of trichlorotrifluoroethane (Freon 113), was examined. There were no subjective complaints, other than one case of dryness of the skin, referable to this occupational exposure. At this time, it is our opinion that there is no evidence of adverse effects from exposure to trichlorotrifluoroethane under the conditions encountered by these personnel. We believe that continued, periodic, follow-up examinations of these workers will be helpful in further evaluating any possible long-range effects of this material.

  13. Chromosome aberrations in workers exposed to arsenic.

    PubMed

    Beckman, G; Beckman, L; Nordenson, I

    1977-08-01

    The occurrence of chromosome aberrations was studied in short-term cultured lymphocytes from nine workers exposed to arsenic at the Rönnskär smeltery in northern Sweden. In the smelter workers, 87 aberrations were found in 819 mitoses. The number of aberrations varied individually from 0 to 25 aberrations per 100 cells. In a control material 13 aberrations were found in 1012 mitoses. The frequency of chromosome aberrations was significantly increased among the smelter workers, but due to the simultaneous exposure to other agents the effect of arsenic per se can not be assessed with certainty.

  14. Hexamitiasis in cadmium-exposed mice.

    PubMed

    Exon, J H; Patton, N M; Koller, L D

    1975-09-01

    Mortality was observed in 4- to 5-week-old Swiss Webster mice exposed to 300 or 3 ppm cadmium as cadmium chloride in the drinking water. Mice receiving 300 ppm cadium suffered 26% mortality as compared with 7% of those on the low cadmium dose. Death did not occur in control mice. Clinical signs and histopathology established Hexamita muris as the causative agent. Cadmium lesions were not observed. It is suggested that mortality due to hexamitiasis resulted from synergism between cadmium and H muris.

  15. The PUR Experiment on the EXPOSE-R facility: biological dosimetry of solar extraterrestrial UV radiation

    NASA Astrophysics Data System (ADS)

    Bérces, A.; Egyeki, M.; Fekete, A.; Horneck, G.; Kovács, G.; Panitz, C.

    2015-01-01

    The aim of our experiment Phage and Uracil Response was to extend the use of bacteriophage T7 and uracil biological dosimeters for measuring the biologically effective ultraviolet (UV) dose in the harsh extraterrestrial radiation conditions. The biological detectors were exposed in vacuum-tightly cases in the European Space Agency (ESA) astrobiological exposure facility attached to the external platform of Zvezda (EXPOSE-R). EXPOSE-R took off to the International Space Station (ISS) in November 2008 and was installed on the External platform of the Russian module Zvezda of the ISS in March 2009. Our goal was to determine the dose-effect relation for the formation of photoproducts (i.e. damage to phage DNA and uracil, respectively). The extraterrestrial solar UV radiation ranges over the whole spectrum from vacuum-UV (λ<200 nm) to UVA (315 nm<λ<400 nm), which causes photolesions (photoproducts) in the nucleic acids/their components either by photoionization or excitation. However, these wavelengths cause not only photolesions but in a wavelength-dependent efficiency the reversion of some photolesions, too. Our biological detectors measured in situ conditions the resultant of both reactions induced by the extraterrestrial UV radiation. From this aspect the role of the photoreversion in the extension of the biological UV dosimetry are discussed.

  16. Erythrocyte survival in sheep exposed to ozone

    SciTech Connect

    Moore, G.S.; Calabrese, E.J.; Labato, F.J.

    1981-07-01

    Erythrocyte survival studies in the Dorset ewe using chromium 51 were performed. The purpose of the study was to determine if ozone exposure produces decreased cell survival which may be the result of premature erythrocyte aging. This strain of sheep has an erythrocyte glucose-6-phosphate dehydrogenase (G6PD) activity that is very low, being comparable to human A-variants with G6PD deficiency. Ozone exposure may produce hemolytic effects in G6PD deficients more readily than in erythrocytes with normal activity. A decrease in hematocrit was observed in the ozone exposed groups. With respect to red cell destruction, ozone does not appear to act immediately, but rather there appears to be a delayed effect. At 0.25 ppM ozone, the group reached the 50% remaining level an average of 1 day sooner than the control group. There was no significant difference between control and exposed groups at the 0.50 ppM and 0.70 ppM levels. Also, the results demonstrate a net decrease in hematocrit which is greater for 0.25 ppM ozone than any other exposure level. (RJC)

  17. Heart disease in workers exposed to dinitrotoluene

    SciTech Connect

    Levine, R.J.; Andjelkovich, D.A.; Kersteter, S.L.; Arp, E.W. Jr.; Balogh, S.A.; Blunden, P.B.; Stanley, J.M.

    1986-09-01

    To determine whether the carcinogenicity of dinitrotoluene (DNT) in rodent bioassays was predictive for humans, we examined the mortality experience of exposed workers at two ammunition plants. Cohorts of 156 and 301 men who had worked a month or more during the 1940s and 1950s at jobs with opportunity for substantial DNT exposure were followed through the end of 1980. Numbers of expected deaths and standardized mortality ratios (SMRs) were computed, using mortality rates of US white males as the standard. No evidence of a carcinogenic effect was found, but unsuspected excesses of mortality from ischemic heart disease were noted at both plants (SMRs) 131 and 143; 95% confidence limits 65 to 234 and 107 to 187, respectively). Deaths from ischemic heart disease remained high even when compared with expected numbers derived using mortality rates of the counties in which the plants were located. Additional analyses revealed evidence of a 15-year latent period and suggested a relationship with duration and intensity of exposure. Epidemiologic investigations of other heavily exposed populations are needed to confirm the etiologic significance of the association between DNT and heart disease described here.

  18. A Successful Crayfish Invader Is Capable of Facultative Parthenogenesis: A Novel Reproductive Mode in Decapod Crustaceans

    PubMed Central

    Buřič, Miloš; Hulák, Martin; Kouba, Antonín

    2011-01-01

    Biological invasions are impacting biota worldwide, and explaining why some taxa tend to become invasive is of major scientific interest. North American crayfish species, particularly of the family Cambaridae, are prominent invaders in freshwaters, defying the “tens rule” which states that only a minority of species introduced to new regions become established, and only a minority of those become invasive and pests. So far, success of cambarid invaders has largely been attributed to rapid maturation, high reproductive output, aggressiveness, and tolerance to pollution. We provide experimental evidence that females of one cambarid species particularly widespread in Europe, the spiny-cheek crayfish Orconectes limosus, are capable of facultative parthenogenesis. Such reproductive mode has never before been recognized in decapods, the most diverse crustacean order. As shown by analysis of seven microsatellite loci, crayfish females kept physically separated from males produced genetically homogeneous offspring identical with maternal individuals; this suggests they reproduced by apomixis, unlike those females which mated with males and had a diverse offspring. Further research is needed to clarify what environmental conditions are necessary for a switch to parthenogenesis in O. limosus, and what role it plays in natural crayfish populations. However, if such reproductive plasticity is present in other cambarid crayfish species, it may contribute to the overwhelming invasive success of this group. PMID:21655282

  19. Dust release from surfaces exposed to plasma

    SciTech Connect

    Flanagan, T. M.; Goree, J.

    2006-12-15

    Micrometer-sized particles adhered to a surface can be released when exposed to plasma. In an experiment with a glass surface coated with lunar-simulant dust, it was found that particle release requires exposure to both plasma and an electron beam. The dust release rate diminishes almost exponentially in time, which is consistent with a random process. As proposed here, charges of particles adhered to the surface fluctuate. These charges experience a fluctuating electric force that occasionally overcomes the adhesive van der Waals force, causing particle release. The release rate increases with plasma density, so that plasma cleaning is feasible at high plasma densities. Applications of this cleaning include controlling particulate contamination in semiconductor manufacturing, dust mitigation in the exploration of the moon and Mars, and dusty plasmas.

  20. Plasma prolactin concentrations in lead exposed workers.

    PubMed

    Govoni, S; Battaini, F; Fernicola, C; Castelletti, L; Trabucchi, M

    1987-01-01

    Plasma Prolactin (Prl) Zinc protoporphyrin (Zpp) and blood lead concentrations (PbB) were measured in 76 exposed male workers. All of them were employed in small (not more than 30 persons) pewter factories and were randomly selected from those regularly controlled by the National Health Service, Occupational Health Unit of Brescia (USSL 41). Although all plasma Prl values were within the normal range, the mean value of the subgroup having Zpp and PbB higher than 40 micrograms/dl was significantly higher (+47%) than that observed in the group of workers having Zpp and PbB less than 40 micrograms/dl. The data indicate the possibility of a lead-induced Prl secretion dysfunction, probably mediated by a decrease in dopaminergic inhibitory control.

  1. Plasma prolactin concentrations in lead exposed workers.

    PubMed

    Govoni, S; Battaini, F; Fernicola, C; Castelletti, L; Trabucchi, M

    1987-01-01

    Plasma Prolactin (Prl) Zinc protoporphyrin (Zpp) and blood lead concentrations (PbB) were measured in 76 exposed male workers. All of them were employed in small (not more than 30 persons) pewter factories and were randomly selected from those regularly controlled by the National Health Service, Occupational Health Unit of Brescia (USSL 41). Although all plasma Prl values were within the normal range, the mean value of the subgroup having Zpp and PbB higher than 40 micrograms/dl was significantly higher (+47%) than that observed in the group of workers having Zpp and PbB less than 40 micrograms/dl. The data indicate the possibility of a lead-induced Prl secretion dysfunction, probably mediated by a decrease in dopaminergic inhibitory control. PMID:3598878

  2. Exposing calculus students to advanced mathematics

    NASA Astrophysics Data System (ADS)

    Griffiths, Barry J.; Selcuk Haciomeroglu, Erhan

    2014-07-01

    To ensure the competitiveness of the USA in the global economy, and its role as a leader in science and engineering, it is important to cultivate the next generation of home grown mathematicians. However, while universities across the USA offer calculus classes to thousands of undergraduate students each year, very few of them go on to major in mathematics. This paper posits that one of the main reasons is that the mathematical community does not expose calculus students to the beauty and complexity of upper-level mathematics, and that by doing so before they fully commit to their programme of study, the number of students with a qualification in mathematics can be increased. The results show a significant increase in the number of students planning to add a minor in mathematics, and an increased likelihood among freshmen and sophomores to change their major.

  3. Exposed polyurethane seen as fire hazard

    SciTech Connect

    Weaver, M.

    1982-11-29

    Improperly exposed polyurethane insulation is a fire hazard. Recent fire tragedies underscore the importance of installing approved thermal barriers over the foam. Vendors warn of the need to follow building codes and manufacturer's guidelines, and stress the absence of hazards if this is done. Polyurethane foam requires a high temperature to ignite but, once ignited, flashes intensely. The foam smolders at lower temperatures, however, and gives off combustible gases. The risk is higher in warehouses and other buildings where the foam is often sprayed on the walls and left uncovered and in upholstered furniture. Lawsuits resulted over claims that the material is self-extinguishing. Vendors list commercially available thermal barriers and factors customers should consider before investing in foam. (DCK)

  4. Behavioral changes in fish exposed to phytoestrogens.

    PubMed

    Clotfelter, Ethan D; Rodriguez, Alison C

    2006-12-01

    We investigated the behavioral effects of exposure to waterborne phytoestrogens in male fighting fish, Betta splendens. Adult fish were exposed to a range of concentrations of genistein, equol, beta-sitosterol, and the positive control 17beta-estradiol. The following behaviors were measured: spontaneous swimming activity, latency to respond to a perceived intruder (mirror reflection), intensity of aggressive response toward a perceived intruder, probability of constructing a nest in the presence of a female, and the size of the nest constructed. We found few changes in spontaneous swimming activity, the latency to respond to the mirror, and nest size, and modest changes in the probability of constructing a nest. There were significant decreases, however, in the intensity of aggressive behavior toward the mirror following exposure to several concentrations, including environmentally relevant ones, of 17beta-estradiol, genistein, and equol. This suggests that phytoestrogen contamination has the potential to significantly affect the behavior of free-living fishes.

  5. Adhesive bacterial colonization of exposed traumatized tendon.

    PubMed

    Webb, L X; Hobgood, C D; Meredith, J W; Gristina, A G

    1987-05-01

    Recent studies of compromised or damaged tissues, as well as biomaterials, have shown that they provide a particularly fertile substratum for bacterial colonization. Colonization in these environments is mediated by a process of microbial adhesion to surfaces of the substrata. In this report, we present electron microscopic studies of a portion of damaged and infected tendon. These studies demonstrate colonies of bacteria surrounded by a ruthenium red-staining exopolysaccharide biofilm and adhesion to the surface of the tendon by means of an exopolysaccharide polymer. We suggest that this adhesive form of bacterial colonization may partially explain the resistance of exposed tendon to effective debridement by simple mechanical measures and to coverage with granulation tissue, partial-thickness skin grafts, and vascularized tissue grafts.

  6. Behavioral changes in fish exposed to phytoestrogens.

    PubMed

    Clotfelter, Ethan D; Rodriguez, Alison C

    2006-12-01

    We investigated the behavioral effects of exposure to waterborne phytoestrogens in male fighting fish, Betta splendens. Adult fish were exposed to a range of concentrations of genistein, equol, beta-sitosterol, and the positive control 17beta-estradiol. The following behaviors were measured: spontaneous swimming activity, latency to respond to a perceived intruder (mirror reflection), intensity of aggressive response toward a perceived intruder, probability of constructing a nest in the presence of a female, and the size of the nest constructed. We found few changes in spontaneous swimming activity, the latency to respond to the mirror, and nest size, and modest changes in the probability of constructing a nest. There were significant decreases, however, in the intensity of aggressive behavior toward the mirror following exposure to several concentrations, including environmentally relevant ones, of 17beta-estradiol, genistein, and equol. This suggests that phytoestrogen contamination has the potential to significantly affect the behavior of free-living fishes. PMID:16584819

  7. Mortality of aerospace workers exposed to trichloroethylene.

    PubMed

    Morgan, R W; Kelsh, M A; Zhao, K; Heringer, S

    1998-07-01

    We measured mortality rates in a cohort of 20,508 aerospace workers who were followed up over the period 1950-1993. A total of 4,733 workers had occupational exposure to trichloroethylene. In addition, trichloroethylene was present in some of the washing and drinking water used at the work site. We developed a job-exposure matrix to classify all jobs by trichloroethylene exposure levels into four categories ranging from "none" to "high" exposure. We calculated standardized mortality ratios for the entire cohort and the trichloroethylene exposed subcohort. In the standardized mortality ratio analyses, we observed a consistent elevation for nonmalignant respiratory disease, which we attribute primarily to the higher background rates of respiratory disease in this region. We also compared trichloroethylene-exposed workers with workers in the "low" and "none" exposure categories. Mortality rate ratios for nonmalignant respiratory disease were near or less than 1.00 for trichloroethylene exposure groups. We observed elevated rare ratios for ovarian cancer among those with peak exposure at medium and high levels] relative risk (RR) = 2.74; 95% confidence interval (CI) = 0.84-8.99] and among women with high cumulative exposure (RR = 7.09; 95% CI = 2.14-23.54). Among those with peak exposures at medium and high levels, we observed slightly elevated rate ratios for cancers of the kidney (RR = 1.89; 95% CI = 0.85-4.23), bladder (RR = 1.41; 95% CI = 0.52-3.81), and prostate (RR = 1.47; 95% CI = 0.85-2.55). Our findings do not indicate an association between trichloroethylene exposure and respiratory cancer, liver cancer, leukemia or lymphoma, or all cancers combined. PMID:9647907

  8. 9 CFR 78.23 - Brucellosis exposed bison.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Brucellosis exposed bison. 78.23... Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.23 Brucellosis exposed bison. Brucellosis exposed bison may be moved interstate only as follows: (a) Movement to recognized...

  9. 9 CFR 78.23 - Brucellosis exposed bison.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Brucellosis exposed bison. 78.23... Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.23 Brucellosis exposed bison. Brucellosis exposed bison may be moved interstate only as follows: (a) Movement to recognized...

  10. 9 CFR 78.23 - Brucellosis exposed bison.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Brucellosis exposed bison. 78.23... Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.23 Brucellosis exposed bison. Brucellosis exposed bison may be moved interstate only as follows: (a) Movement to recognized...

  11. 9 CFR 78.23 - Brucellosis exposed bison.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Brucellosis exposed bison. 78.23... Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.23 Brucellosis exposed bison. Brucellosis exposed bison may be moved interstate only as follows: (a) Movement to recognized...

  12. 9 CFR 78.23 - Brucellosis exposed bison.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Brucellosis exposed bison. 78.23... Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.23 Brucellosis exposed bison. Brucellosis exposed bison may be moved interstate only as follows: (a) Movement to recognized...

  13. 9 CFR 78.8 - Brucellosis exposed cattle.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Brucellosis exposed cattle. 78.8... Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.8 Brucellosis exposed cattle. Brucellosis exposed cattle may be moved interstate only as follows: (a) Movement to recognized...

  14. 9 CFR 78.8 - Brucellosis exposed cattle.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Brucellosis exposed cattle. 78.8... Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.8 Brucellosis exposed cattle. Brucellosis exposed cattle may be moved interstate only as follows: (a) Movement to recognized...

  15. 9 CFR 78.8 - Brucellosis exposed cattle.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Brucellosis exposed cattle. 78.8... Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.8 Brucellosis exposed cattle. Brucellosis exposed cattle may be moved interstate only as follows: (a) Movement to recognized...

  16. 9 CFR 78.8 - Brucellosis exposed cattle.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Brucellosis exposed cattle. 78.8... Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.8 Brucellosis exposed cattle. Brucellosis exposed cattle may be moved interstate only as follows: (a) Movement to recognized...

  17. 9 CFR 78.32 - Brucellosis exposed swine.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Brucellosis exposed swine. 78.32... Restrictions on Interstate Movement of Swine Because of Brucellosis § 78.32 Brucellosis exposed swine. (a) Brucellosis exposed swine may be moved interstate only if accompanied by a permit and only for...

  18. 9 CFR 78.32 - Brucellosis exposed swine.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Brucellosis exposed swine. 78.32... Restrictions on Interstate Movement of Swine Because of Brucellosis § 78.32 Brucellosis exposed swine. (a) Brucellosis exposed swine may be moved interstate only if accompanied by a permit and only for...

  19. 9 CFR 78.32 - Brucellosis exposed swine.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Brucellosis exposed swine. 78.32... Restrictions on Interstate Movement of Swine Because of Brucellosis § 78.32 Brucellosis exposed swine. (a) Brucellosis exposed swine may be moved interstate only if accompanied by a permit and only for...

  20. 9 CFR 78.32 - Brucellosis exposed swine.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Brucellosis exposed swine. 78.32... Restrictions on Interstate Movement of Swine Because of Brucellosis § 78.32 Brucellosis exposed swine. (a) Brucellosis exposed swine may be moved interstate only if accompanied by a permit and only for...

  1. Single authentication: exposing weighted splining artifacts

    NASA Astrophysics Data System (ADS)

    Ciptasari, Rimba W.

    2016-05-01

    A common form of manipulation is to combine parts of the image fragment into another different image either to remove or blend the objects. Inspired by this situation, we propose a single authentication technique for detecting traces of weighted average splining technique. In this paper, we assume that image composite could be created by joining two images so that the edge between them is imperceptible. The weighted average technique is constructed from overlapped images so that it is possible to compute the gray level value of points within a transition zone. This approach works on the assumption that although splining process leaves the transition zone smoothly. They may, nevertheless, alter the underlying statistics of an image. In other words, it introduces specific correlation into the image. The proposed idea dealing with identifying these correlations is to generate an original model of both weighting function, left and right functions, as references to their synthetic models. The overall process of the authentication is divided into two main stages, which are pixel predictive coding and weighting function estimation. In the former stage, the set of intensity pairs {Il,Ir} is computed by exploiting pixel extrapolation technique. The least-squares estimation method is then employed to yield the weighted coefficients. We show the efficacy of the proposed scheme on revealing the splining artifacts. We believe that this is the first work that exposes the image splining artifact as evidence of digital tampering.

  2. Neurotoxicity of Acrylamide in Exposed Workers

    PubMed Central

    Pennisi, Manuela; Malaguarnera, Giulia; Puglisi, Valentina; Vinciguerra, Luisa; Vacante, Marco; Malaguarnera, Mariano

    2013-01-01

    Acrylamide (ACR) is a water-soluble chemical used in different industrial and laboratory processes. ACR monomer is neurotoxic in humans and laboratory animals. Subchronic exposure to this chemical causes neuropathies, hands and feet numbness, gait abnormalities, muscle weakness, ataxia, skin and in some cases, cerebellar alterations. ACR neurotoxicity involves mostly the peripheral but also the central nervous system, because of damage to the nerve terminal through membrane fusion mechanisms and tubulovescicular alterations. Nevertheless, the exact action mechanism is not completely elucidated. In this paper we have reviewed the current literature on its neurotoxicity connected to work-related ACR exposure. We have analyzed not only the different pathogenetic hypotheses focusing on possible neuropathological targets, but also the critical behavior of ACR poisoning. In addition we have evaluated the ACR-exposed workers case studies. Despite all the amount of work which have being carried out on this topic more studies are necessary to fully understand the pathogenetic mechanisms, in order to propose suitable therapies. PMID:23985770

  3. Thyroid hormones in chronic heat exposed men

    NASA Astrophysics Data System (ADS)

    Gertner, A.; Israeli, R.; Lev, A.; Cassuto, Y.

    1983-03-01

    Previous reports have indicated that thyroid gland activity, is depressed in the heat. Total thyroxine (T4) and triiodothyronine (T3) serum levels in 17 workers of the metal work shop at a plant near the Dead Sea and 8 workers in Beer Sheva, Israel were examined. The metal workshop of the plant near the Dead Sea is part of a large chemical plant. The one in Beer Sheva is part of a large construction company. Maintenance work, as well as metal work projects are performed in both workshops. During the work shifts, the workers of the Dead Sea plant were exposed to temperatures ranging from 30 36°C (May Oct.) and 14 21°C (Dec. Feb). In Beer Sheva the range was 25 32°C (June Sept.) and 10 17°C (Dec. Feb.). Total T4 was measured by competitive protein binding and total T3 by radioimmunoassay in blood drawn before work (0700) in July and January. In summer. T4 was higher and T3 was lower for both groups than in winter. The observed summer T3 decrease may result from depressed extrathyroidal conversion of T4 to T3. We conclude that the regulation of energy metabolism in hot climates may be related to extrathyroidal conversion of T4 to T3.

  4. The SPORES experiment of the EXPOSE-R mission: Bacillus subtilis spores in artificial meteorites

    NASA Astrophysics Data System (ADS)

    Panitz, Corinna; Horneck, Gerda; Rabbow, Elke; Rettberg, Petra; Moeller, Ralf; Cadet, Jean; Douki, Thierry

    2015-01-01

    The experiment SPORES `Spores in artificial meteorites' was part of European Space Agency's EXPOSE-R mission, which exposed chemical and biological samples for nearly 2 years (March 10, 2009 to February 21, 2011) to outer space, when attached to the outside of the Russian Zvezda module of the International Space Station. The overall objective of the SPORES experiment was to address the question whether the meteorite material offers enough protection against the harsh environment of space for spores to survive a long-term journey in space by experimentally mimicking the hypothetical scenario of Lithopanspermia, which assumes interplanetary transfer of life via impact-ejected rocks. For this purpose, spores of Bacillus subtilis 168 were exposed to selected parameters of outer space (solar ultraviolet (UV) radiation at λ>110 or >200 nm, space vacuum, galactic cosmic radiation and temperature fluctuations) either as a pure spore monolayer or mixed with different concentrations of artificial meteorite powder. Total fluence of solar UV radiation (100-400 nm) during the mission was 859 MJ m-2. After retrieval the viability of the samples was analysed. A Mission Ground Reference program was performed in parallel to the flight experiment. The results of SPORES demonstrate the high inactivating potential of extraterrestrial UV radiation as one of the most harmful factors of space, especially UV at λ>110 nm. The UV-induced inactivation is mainly caused by photodamaging of the DNA, as documented by the identification of the spore photoproduct 5,6-dihydro-5(α-thyminyl)thymine. The data disclose the limits of Lithopanspermia for spores located in the upper layers of impact-ejected rocks due to access of harmful extraterrestrial solar UV radiation.

  5. Comparative Toxicological Study between Exposed and Non-Exposed Farmers to Organophosphorus Pesticides

    PubMed Central

    Taghavian, Fariba; Vaezi, Gholamhassan; Abdollahi, Mohammad; Malekirad, Ali Akbar

    2016-01-01

    Objective The purpose of this work was to compare DNA damage, acetylcholinesterase (AChE) activity, inflammatory markers and clinical symptoms in farmers exposed to organophosphorus pesticides to individuals that had no pesticide exposure. Materials and Methods We conducted a cross-sectional survey with a total of 134 people. The subject group consisted of 67 farmers who were exposed to organophosphorus pesticides. The control group consisted of 67 people without any contact with pesticides matched with the subject group in terms of age, gender, and didactics. Oxidative DNA damage, the activities of AChE, interleukin-6 (IL6), IL10 and C-reactive protein (CRP) in serum were measured and clinical examinations conducted in order to register all clinical signs. Results Compared with the control group, substantial gains were observed in the farmers’ levels of oxidative DNA damage, IL10 and CRP. There was significantly less AChE activity in farmers exposed to organophosphorus pesticides. The levels of IL6 in both groups did not significantly differ. Conclusion The outcomes show that exposure to organophosphorus pesticides may cause DNA oxidative damage, inhibit AChE activity and increase the serum levels of inflammatory markers. Using biological materials instead of chemical pesticides and encouraging the use of safety equipment by farmers are some solutions to the adverse effects of exposure to organophosphorous pesticides. PMID:27054123

  6. Prolonged grief among traumatically bereaved relatives exposed and not exposed to a tsunami.

    PubMed

    Johannesson, Kerstin Bergh; Lundin, Tom; Hultman, Christina M; Fröjd, Thomas; Michel, Per-Olof

    2011-08-01

    Numerous studies on the mental health consequences of traumatic exposure to a disaster compare those exposed to those not exposed. Relatively few focus on the effect of the death of a close relative caused by the disaster-suffering a traumatic bereavement. This study compared the impact on 345 participants who lost a close relative in the 2004 Indian Ocean tsunami, but who were themselves not present, to 141 who not only lost a relative, but also were themselves exposed to the tsunami. The focus was on psychological distress assessed during the second year after the sudden bereavement. Findings were that exposure to the tsunami was associated with prolonged grief (B = 3.81) and posttraumatic stress reactions (B = 6.65), and doubled the risk for impaired mental health. Loss of children increased the risk for psychological distress (prolonged grief: B = 6.92; The Impact of Event Scale-Revised: B = 6.10; General Health Questionnaire-12: OR = 2.34). Women had a higher frequency of prolonged grief. For men, loss of children presented a higher risk for prolonged grief in relation to other types of bereavement (B = 6.36 vs. loss of partner). Further long-term follow-up could deepen the understanding of how recovery after traumatic loss is facilitated.

  7. Treadmill exercise alters histone acetylation differently in rats exposed or not exposed to aversive learning context.

    PubMed

    de Meireles, Louisiana Carolina Ferreira; Bertoldi, Karine; Elsner, Viviane Rostirola; Moysés, Felipe dos Santos; Siqueira, Ionara Rodrigues

    2014-12-01

    Epigenetic modifications have been linked to memory formation after learning context exposure and to exercise effects on memory performance. The aim of this study was to investigate the effect of treadmill exercise (20 min/day during 2 weeks) on H3K14 acetylation and H3S10 phosphorylation levels in the hippocampi of 3-month-old Wistar rats exposed and not exposed to aversive learning context. Male Wistar rats aged 2-3 months were assigned to non-exercised (sedentary) and exercised (running daily for 20 min for 2 weeks) groups. Single-trial step-down inhibitory avoidance (IA) conditioning was employed as an aversive memory model. Epigenetic parameters were determined 30 min after the IA test. A decrease in the H3K14 acetylation in the hippocampus 24 h after IA training (30 min after test session) was observed. Exercise reversed the IA effect, and no effect was observed in the non-IA exposed group. Our data support the hypothesis that modulation of H3K14 acetylation levels in the hippocampus might be related, at least in part, to exercise effects on aversive memory.

  8. Comparative genomic hybridization study of arsenic-exposed and non-arsenic-exposed urinary transitional cell carcinoma

    SciTech Connect

    Hsu, L.-I; Chiu, Allen W.; Pu, Y.-S.; Wang, Y.-H.; Huan, Steven K.; Hsiao, C.-H.; Hsieh, F.-I; Chen, C.-J.

    2008-03-01

    To compare the differences in DNA aberrations between arsenic-exposed and non-arsenic-exposed transitional cell carcinoma (TCC), we analyzed 19 arsenic-exposed and 29 non-arsenic-exposed urinary TCCs from Chi-Mei Hospital using comparative genomic hybridization. DNA aberrations were detected in 42 TCCs including 19 arsenic-exposed and 23 non-arsenic-exposed TCCs. Arsenic-exposed TCCs had more changes than unexposed TCCs (mean {+-} SD, 6.6 {+-} 2.9 vs. 2.9 {+-} 2.2). Arsenic exposure was significantly associated with the number of DNA aberrations after adjustment for tumor stage, tumor grade and cigarette smoking in multiple regression analysis. The most frequent DNA gains, which were strikingly different between arsenic-exposed and non-arsenic-exposed TCCs, included those at 1p, 4p, 4q and 8q. A much higher frequency of DNA losses in arsenic-exposed TCCs compared with non-arsenic-exposed TCCs was observed in 10q, 11p and 17p. Chromosomal loss in 17p13 was associated not only with arsenic exposure, but also with tumor stage and grade. The p53 immunohistochemistry staining showed that chromosome 17p13 loss was associated with either p53 no expression (25%) or p53 overexpression (75%). The findings suggest that long-term arsenic exposure may increase the chromosome abnormality in TCC, and 17p loss plays an important role in arsenic-induced urinary carcinogenesis.

  9. Antinuclear antibody and rheumatoid factor in silica-exposed workers.

    PubMed

    Aminian, Omid; Sharifian, Seyed Akbar; Mehrdad, Ramin; Haghighi, Khosro Sadeghniyat; Mazaheri, Maria

    2009-06-01

    A lot of workers in industries such as foundry, stonecutting, and sandblasting are exposed to higher than permissible levels of crystalline silica. Various alterations in humoral immune function have been reported in silicosis patients and workers exposed to silica dust. The aim of this study was to measure antinuclear antibody (ANA) and rheumatoid factor (RF) levels in foundry workers exposed to silica and to compare them with a control group without such exposure. ANA and RF were measured in 78 exposed and 73 non-exposed workers, and standard statistical methods were used to compare them. The two groups did not significantly differ in age and smoking. Mean work duration of the exposed and non-exposed workers was (14.9+/-4.72) years and (12.41+/-6.3) years, respectively. Ten exposed workers had silicosis. ANA was negative in all workers in either group. Its mean titer did not differ significantly between the exposed and control workers [(0.39+/-0.15) IU mL(-1) vs. (0.36+/-0.17) IU mL(-1), respectively]. RF was positive in two workers of each group. Other studies have reported an increase in ANA and RF associated with exposure to silica dust and silicosis.In contrast, our study suggests that exposure to silica dust does not increase the level of ANA and RF in exposed workers. PMID:19581212

  10. Distribution and conservation standing of West Virginia crayfishes

    USGS Publications Warehouse

    Loughman, Zachary J.; Welsh, Stuart

    2010-01-01

    The diversity of crayfishes in West Virginia represents a transition between the species-rich southern Appalachian faunas and the depauperate crayfish diversity in the northeastern United States. Currently, 22 described species occur in the state, of which 6 are given S1 status, and 3 are introduced species. One species, Orconectes limosus (Spinycheek Crayfish) is considered extirpated within the past decade. Imperiled species include Cambarus veteranus (Big Sandy Crayfish),Cambarus elkensis (Elk River Crayfish), Cambarus longulus (Atlantic Slope Crayfish), andCambarus nerterius (Greenbrier Cave Crayfish). Three species—O. virilis (Virile Crayfish),Orconectes rusticus (Rusty Crayfish), and Procambarus zonangulus (Southern White River Crawfish)—have introduced populations within the state. Procambarus acutus (White River Crawfish) occurs in bottomland forest along the Ohio River floodplain, and is considered native. Several undescribed taxa have been identified and currently are being described. A statewide survey was initiated in 2007 to document the current distribution and conservation status of crayfishes in West Virginia.

  11. Degradation of HEPA filters exposed to DMSO

    SciTech Connect

    Bergman, W.; Wilson, K.; Larsen, G.; Lopez, R.; LeMay, J.

    1994-07-11

    Dimethyl sulfoxide (DMSO) sprays are being used to remove the high explosive (HE) from nuclear weapons in the process of their dismantlement. A boxed 50 cfm HEPA filter with an integral prefilter was exposed to DMSO vapor and aerosols that were generated by a spray nozzle to simulate conditions expected in the HE dissolution operation. After 198 hours of operation, the pressure drop of the filter had increased from 1.15 inches to 2.85 inches, and the efficiency for 0.3 {mu}m dioctyl sebacate (DOS) aerosols decreased from 99.992% to 98.6%. Most of the DMSO aerosols had collected as a liquid pool inside the boxed HEPA. The liquid was blown out of the filter exit with 100 cfm air flow at the end of the test. Since the filter still met the minimum allowed efficiency of 99.97% after 166 hours of exposure, we recommend replacing the filter every 160 hours of operation or sooner if the pressure drop increases by 50%. Examination of the filter showed that visible cracks appeared at the joints of the wooden frame and a portion of the sealant had pulled away from the frame. Since all of the DMSO will be trapped in the first HEPA filter, the second HEPA filter should not suffer from DMSO degradation. Thus the combined efficiency for the first filter (98.6%) and the second filter (99.97%) is 99.99996% for 0.3{mu}m particles. If the first filter is replaced prior to its degradation, each of the filters will have 99.97% efficiency, and the combined efficiency will be 99.999991%. The collection efficiency for DMSO/HE aerosols will be much higher because the particle size is much greater.

  12. Degradation of HEPA filters exposed to DMSO

    SciTech Connect

    Bergman, W.; Wilson, K.; Larsen, G.

    1995-02-01

    Dimethyl sulfoxide (DMSO) sprays are being used to remove the high explosive (HE) from nuclear weapons in the process of their dismantlement. A boxed 50 cmf HEPA filter with an integral prefilter was exposed to DMSO vapor and aerosols that were generated by a spray nozzle to simulate conditions expected in the HE dissolution operation. After 198 hours of operation, the pressure drop of the filter had increased form 1.15 inches to 2,85 inches, and the efficiency for 0.3 {mu}m dioctyl sebacate (DOS) aerosols decreased form 99.992% to 98.6%. Most of the DMSO aerosols had collected as a liquid pool inside the boxed HEPA. The liquid was blown out of the filter exit with 100 cmf air flow at the end of the test. Since the filter still met the minimum allowed efficiency of 99.97% after 166 hours of exposure, we recommend replacing the filter every 160 hours of operation or sooner if the pressure drop increases by 50%. Examination of the filter showed that visible cracks appeared at the joints of the wooden frame and a portion of the sealant had pulled away from the frame. Since all of the DMSO will be trapped in the first HEPA filter, the second HEPA filter should not suffer from DMSO degradation. Thus the combined efficiency for the first filter (98.6%) and the second filter (99.97%) is 99.99996% for 0.3 {mu}m particles. If the first filter is replaced prior to its degradation, each of the filters will have 99.97% efficiency, and the combined efficiency will be 99.999991%. The collection efficiency for DMSO/HE aerosols will be much higher because the particle size is much greater.

  13. Assessing the photoaging process at sun exposed and non-exposed skin using fluorescence lifetime spectroscopy

    NASA Astrophysics Data System (ADS)

    Saito Nogueira, Marcelo; Kurachi, Cristina

    2016-03-01

    Photoaging is the skin premature aging due to exposure to ultraviolet light, which damage the collagen, elastin and can induce alterations on the skin cells DNA, and, then, it may evolve to precancerous lesions, which are widely investigated by fluorescence spectroscopy and lifetime. The fluorescence spectra and fluorescence lifetime analysis has been presented as a technique of great potential for biological tissue characterization at optical diagnostics. The main targeted fluorophores are NADH (nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide), which have free and bound states, each one with different average lifetimes. The average lifetimes for free and bound NADH and FAD change according to tissue metabolic alterations and may contribute to a non-invasive clinical investigation of injuries such as skin lesions. These lesions and the possible areas where they may develop can be interrogated using fluorescence lifetime spectroscopy taking into account the variability of skin phototypes and the changes related to melanin, collagen and elastin, endogenous fluorophores which have emissions that spectrally overlap to the NADH and FAD emission. The objective of this study is to assess the variation on fluorescence lifetimes of normal skin at sun exposed and non-exposed areas and associate this variation to the photoaging process.

  14. 31. VIEW OF ROOM 212 LOOKING NORTHWEST TOWARDS EXPOSED STUD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. VIEW OF ROOM 212 LOOKING NORTHWEST TOWARDS EXPOSED STUD WALL THAT SERVES AS DIVIDER TO ROOM 211. EXPOSED TRUSSWORK VISIBLE THROUGH TO NEXT ROOM. WOOD PANELED WALLS ARE PAINTED; FLOORS ARE WOOD. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

  15. Reactivity and Regulation in Children Prenatally Exposed to Cocaine

    ERIC Educational Resources Information Center

    Dennis, Tracy; Bendersky, Margaret; Ramsay, Douglas; Lewis, Michael

    2006-01-01

    Children prenatally exposed to cocaine may be at elevated risk for adjustment problems in early development because of greater reactivity and reduced regulation during challenging tasks. Few studies have examined whether cocaine-exposed children show such difficulties during the preschool years, a period marked by increased social and cognitive…

  16. Psychological Functioning of Children Exposed to Cocaine Prenatally.

    ERIC Educational Resources Information Center

    Granick, Samuel

    1995-01-01

    A sample of 25 children exposed prenatally to cocaine was compared with a control group of 18 children not exposed to any drugs prenatally. Using the AGS (American Guidance Service) Screening Profile, results indicated that the control group was significantly superior on all subtests except for the Motor Coordination and Speech Articulation…

  17. Animal Cruelty by Children Exposed to Domestic Violence

    ERIC Educational Resources Information Center

    Currie, Cheryl L.

    2006-01-01

    Objective: The first objective of this study was to determine if children exposed to domestic violence were significantly more likely to be cruel to animals than children not exposed to violence. The second was to determine if there were significant age and gender differences between children who were and were not cruel to animals. Method: A…

  18. Drug Exposed Infants and Children: Service Needs and Policy Questions.

    ERIC Educational Resources Information Center

    Feig, Laura

    This paper brings together information on the conditions and needs of children who have been exposed to drugs, federal programs that affect the well-being of these children, and policy questions that need resolution. Discussion concerns: (1) characteristics of infants who have been exposed to drugs and their families, including prevalence and…

  19. 9 CFR 78.32 - Brucellosis exposed swine.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Brucellosis exposed swine. 78.32... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Swine Because of Brucellosis § 78.32 Brucellosis exposed swine....

  20. 9 CFR 78.8 - Brucellosis exposed cattle.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Brucellosis exposed cattle. 78.8... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.8 Brucellosis exposed...

  1. The Psychobiology of Children Exposed to Marital Violence

    ERIC Educational Resources Information Center

    Saltzman, Kasey M.; Holden, George W.; Holahan, Charles J.

    2005-01-01

    We examined the psychological and physiological functioning of a community sample of children exposed to marital violence, comparing them to a clinical comparison group without marital violence exposure. Results replicated past findings of elevated levels of trauma symptomatology in this population. Further, children exposed to marital violence…

  2. The differences in phenolic content in rivers exposed and non-exposed to anthropogenic contamination.

    PubMed

    Michałowicz, Jaromir; Bukowska, Bozena; Duda, Wirgiliusz

    2008-03-01

    The purpose of the work was to determine the differences in a kind, number and concentrations of phenol, chlorophenols, chlorocatechols chlorinated methoxyphenols (chloroguaiacols, chlorosyringols) and 3,4,5-trichloroveratrole in the drainage of the Dzierzazna river, the flow non-exposed to anthropogenic contamination and in the Ner river, the flow exposed to anthropogenic pollution. The samples of water were collected in the Dzierzazna river in the Swoboda locality, the inflow of the Dzierzazna river - the Ciosenka river and, also, in the spring situated in Ciosny Sady locality. Water of the Ner river was collected in points near Łódź, Konstantynów, Poddebice and Dabie towns. The compounds were condensed (adsorbed) and eluted with methylene chloride on octadecyl C18 layer in a Baker Separex system. The obtained eluent was separated using the method of gas chromatography and analysed using mass spectrometry technique. In samples collected from the drainage of the Dzierzazna river phenol, chlorophenols, guaiacol, trichloroguaiacol, tetrachloroguaiacol, trichlorosyringol and 3,4,5-trichloroveratole were determined. As no anthropogenic sources are situated within the drainage of the Dzierzazna river, we may suppose that most of the determined compounds are mainly of natural origin. No or trace concentrations of chlorinated methoxyphenols were noted in the water of the Ner river, but a higher number, and concentrations of chlorophenols and additionally chlorocatechols were determined in this flow. It is also apparent that changes in a number and concentrations of phenols in the water of the Ner river did not prove a seasonal character, which was typical of the Dzierzazna drainage waters.

  3. The AMINO experiment: RNA stability under solar radiation studied on the EXPOSE-R facility of the International Space Station

    NASA Astrophysics Data System (ADS)

    Vergne, Jacques; Cottin, Hervé; da Silva, Laura; Brack, André; Chaput, Didier

    2015-01-01

    Careful examination of the present metabolism and in vitro selection of various catalytic RNAs strongly support the RNA world hypothesis as a crucial step of the origins and early life evolution. Small functional RNAs were exposed from 10 March 2009 to 21 January 2011 to space conditions on board the International Space Station in the EXPOSE-R mission. The aim of this study was to investigate the preservation or modification properties such as integrity of RNAs after space exposition. The exposition to the solar radiation has a strong degradation effect on the size distribution of RNA. Moreover, the comparison between the in-flight samples, exposed to the Sun and not exposed, indicates that the solar radiation degrades RNA bases.

  4. Non-disjunction mutations in Drosophila exposed to magnetic fields

    NASA Astrophysics Data System (ADS)

    Levengood, W. C.

    1987-09-01

    The frequency of XO mutations in Drosophila melanogaster was significantly higher than normal in magnetic field exposed, immature males, than in exposed, mature males. Mutation levels increased with magnetic field strength. Intercellular rings of black magnetic particles were formed in the high magnetic flux region of dorsally exposed, early stage pupae and to a lesser degree in the abdomen of young adult females. Orientation of minute, chromosome associated, magnetic domains within the microenvironment of the developing organism was believed to alter oxidative processes within maturing X+ sperm which during fertilization were incompatible with and destructive to an Xw chromosome in the zygote.

  5. Hepatic function in workers occupationally exposed to carbon tetrachloride.

    PubMed Central

    Tomenson, J A; Baron, C E; O'Sullivan, J J; Edwards, J C; Stonard, M D; Walker, R J; Fearnley, D M

    1995-01-01

    OBJECTIVES--To identify any differences in hepatic function between workers exposed to carbon tetrachloride and controls, and to identify the best variable with which to examine any effects. METHODS--In a cross sectional study of hepatic function in workers occupationally exposed to carbon tetrachloride, 135 exposed employees were compared with 276 non-exposed controls. The exposed group was taken from three sites in the north west of England and the control group included non-exposed workers from one of these sites and another site located nearby. Demographic and alcohol consumption data were collected from both groups by questionnaire. Each member of the study group was allotted a notional estimated exposure to carbon tetrachloride, calculated from historic personal monitoring data and job category. A fasting sample of blood was taken from all participants and analysed for a variety of biochemical and haematological variables. The techniques of univariate and multivariate analysis of variance were used to investigate the effect on biochemical and haematological indices of a range of factors. RESULTS--Multivariate analysis of variance of four core liver function variables, alanine transaminase, aspartate transaminase, alkaline phosphatase, and gamma-glutamyl transferase, showed a significant difference between exposed and non-exposed workers. The univariate analyses identified increases in only alkaline phosphatase and gamma-glutamyl transferase within the exposed group and these did not show a significant dose-response relation. Univariate analysis of variance did show effects of alcohol and age on several variables. Significant differences between exposed and control groups for three haematological variables, haemoglobin, packed cell volume, and red blood count, were thought not to be due to the effects of exposure. Clinical review of exposed subjects with abnormal results did not show clinically evident disease that could have been associated with exposure to

  6. Detail of upper portion of southeast corner showing exposed rafters ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of upper portion of southeast corner showing exposed rafters at eaves; camera facing northwest. - Mare Island Naval Shipyard, Supply Building, Walnut Avenue, southeast corner of Walnut Avenue & Fifth Street, Vallejo, Solano County, CA

  7. Epidemiologic study of workers exposed to titanium dioxide

    SciTech Connect

    Chen, J.L.; Fayerweather, W.E.

    1988-12-01

    The objective of this study was to determine whether workers exposed to titanium dioxide (TiO/sub 2/) had significantly higher risks of lung cancer, chronic respiratory disease, pleural thickening/plaques, or pulmonary fibrosis than referent groups. A total of 1,576 employees exposed to TiO/sub 2/ were observed from 1956 through 1985 for cancer and chronic respiratory disease incidence, and from 1935 through 1983 for mortality. A cross-sectional sample of 398 employees was evaluated for chest roentgenogram abnormalities. Cohort analyses suggested that the risks of developing lung cancer and other fatal respiratory diseases were no higher for TiO/sub 2/-exposed employees than for the referent groups. Nested case-control analyses found no statistically significant associations between TiO/sub 2/ exposure and risk of lung cancer, chronic respiratory disease, and chest roentgenogram abnormalities. No cases of pulmonary fibrosis were observed among TiO/sub 2/-exposed employees.

  8. Heart Docs: Never Expose Kids to Cigarette Smoke

    MedlinePlus

    ... 160911.html Heart Docs: Never Expose Kids to Cigarette Smoke Secondhand smoke can raise children's risk of ... consider making their children's environment smoke-free because cigarette smoke exposure is harmful to children's long-term ...

  9. 20. DETAIL OF INTERIOR WALL WITH PLASTER REMOVED TO EXPOSE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. DETAIL OF INTERIOR WALL WITH PLASTER REMOVED TO EXPOSE STUDS AND BRICKWORK A. C. Eschete, photographer, July 7, 1977 - Bagatelle Plantation, East River Road (moved to Iberville Parish), Donaldsonville, Ascension Parish, LA

  10. 6. Interior view of unoccupied space looking up at exposed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Interior view of unoccupied space looking up at exposed roof structure; showing HVAC duct work and wood structure; near center of building; view to northeast. - Ellsworth Air Force Base, Warehouse, 789 Twining Street, Blackhawk, Meade County, SD

  11. Metrics will expose trusts with poor racial equality feedback.

    PubMed

    2014-10-21

    Trusts that fail to take action on race discrimination will be exposed by a set of metrics expected to be introduced next year, England's chief nursing officer told her black and minority ethnic (BME) advisory group's annual conference last week.

  12. Cancer in People Exposed to Nuclear Weapons Testing

    MedlinePlus

    ... payment of $100,000. Onsite participants People (including military personnel) who were present onsite during above-ground nuclear ... be entitled to a payment of $75,000. (Military personnel exposed to radiation at Hiroshima or Nagasaki are ...

  13. Interior view of groundfloor porch showing exposed concrete floor slab ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view of ground-floor porch showing exposed concrete floor slab system, facing west. - Albrook Air Force Station, Field Officer's Quarters, West side of Dargue Avenue Circle, Balboa, Former Panama Canal Zone, CZ

  14. Detail view of the exposed polychromatic aggregate ceiling designed and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of the exposed polychromatic aggregate ceiling designed and cast by John Joseph Earley for the vehicular entrance portals to the courtyard - United States Department of Justice, Constitution Avenue between Ninth & Tenth Streets, Northwest, Washington, District of Columbia, DC

  15. 7. FOUNDATIONS OF FLUME NO. 8, EXPOSED. SCE negative no. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. FOUNDATIONS OF FLUME NO. 8, EXPOSED. SCE negative no. 3077, January 26, 1916. Photograph by G. Haven Bishop. - Santa Ana River Hydroelectric System, Flumes & Tunnels below Sandbox, Redlands, San Bernardino County, CA

  16. 30. WAIALEIA STREAM CROSSING (30") LOOKING UPSTREAM. PIPE IS EXPOSED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. WAIALEIA STREAM CROSSING (30") LOOKING UPSTREAM. PIPE IS EXPOSED AT LEFT OF CONCRETE STRUCTURE. - Kalaupapa Water Supply System, Waikolu Valley to Kalaupapa Settlement, Island of Molokai, Kalaupapa, Kalawao County, HI

  17. 98. DETAIL VIEW OF STORM DAMAGE AND EXPOSED SUBSTRUCTURE, NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    98. DETAIL VIEW OF STORM DAMAGE AND EXPOSED SUBSTRUCTURE, NORTHWEST SIDE OF 4TH TEE, LOOKING WEST - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

  18. Risk and resilience factors of persons exposed to accidents

    PubMed Central

    HERTA, DANA – CRISTINA; BRÎNDAS, PAULA; TRIFU, RALUCA; COZMAN, DOINA

    2016-01-01

    Background and aims Resilience encompasses factors promoting effective functioning in the context of adversity. Data regarding resilience in the wake of accidental trauma is still scarce. The aim of the current study is to comparatively assess adaptive, life – promoting factors in persons exposed to motor vehicle accidents (MVA) vs. persons exposed to other types of accidents, and to identify psychological factors of resilience and vulnerability in this context of trauma exposure. Methods We assessed 93 participants exposed to accidents out of 305 eligible patients from the Clinical Rehabilitation Hospital and Cluj County Emergency Hospital. The study used Reasons for Living Inventory (RFL) and Life Events Checklist. Scores were comparatively assessed for RFL items, RFL scale and subscales in participants exposed to motor vehicle accidents (MVA) vs. participants exposed to other life – threatening accidents. Results Participants exposed to MVA and those exposed to other accidents had significantly different scores in 7 RFL items. Scores were high in 4 out of 6 RFL subscales for both samples and in most items comprising these subscales, while in the other 2 subscales and in some items comprising them scores were low. Conclusions Low fear of death, physical suffering and social disapproval emerge as risk factors in persons exposed to life – threatening accidents. Love of life, courage in life and hope for the future are important resilience factors after exposure to various types of life – threatening accidents. Survival and active coping beliefs promote resilience especially after motor vehicle accidents. Coping with uncertainty are more likely to foster resilience after other types of life – threatening accidents. Attachment of the accident victim to family promotes resilience mostly after MVA, while perceived attachment of family members to the victim promotes resilience after other types of accidents. PMID:27152078

  19. Ozone exposed epithelial cells modify cocultured natural killer cells

    PubMed Central

    Müller, Loretta; Brighton, Luisa E.

    2013-01-01

    Ozone (O3) causes significant adverse health effects worldwide. Nasal epithelial cells (NECs) are among the first sites within the respiratory system to be exposed to inhaled air pollutants. They recruit, activate, and interact with immune cells via soluble mediators and direct cell-cell contacts. Based on our recent observation demonstrating the presence of natural killer (NK) cells in nasal lavages, the goal of this study was to establish a coculture model of NECs and NK cells and examine how exposure to O3 modifies this interaction. Flow cytometry analysis was used to assess immunophenotypes of NK cells cocultured with either air- or O3-exposed NECs. Our data show that coculturing NK cells with O3-exposed NECs decreased intracellular interferon-γ (IFN-γ), enhanced, albeit not statistically significant, IL-4, and increased CD16 expression on NK cells compared with air controls. Additionally, the cytotoxicity potential of NK cells was reduced after coculturing with O3-exposed NECs. To determine whether soluble mediators released by O3-exposed NECs caused this shift, apical and basolateral supernatants of air- and O3-exposed NECs were used to stimulate NK cells. While the conditioned media of O3-exposed NECs alone did not reduce intracellular IFN-γ, O3 enhanced the expression of NK cell ligands ULBP3 and MICA/B on NECs. Blocking ULBP3 and MICA/B reversed the effects of O3-exposed NECs on IFN-γ production in NK cells. Taken together, these data showed that interactions between NECs and NK cells in the context of O3 exposure changes NK cell activity via direct cell-cell interactions and is dependent on ULBP3/MICA/B expressed on NECs. PMID:23241529

  20. Partially exposed polymer dispersed liquid crystals for boundary layer investigations

    NASA Technical Reports Server (NTRS)

    Parmar, Devendra S.; Singh, Jag J.

    1992-01-01

    A new configuration termed partially exposed polymer dispersed liquid crystal in which the liquid crystal microdroplets dispersed in a rigid polymer matrix are partially entrapped on the free surface of the thin film deposited on a glass substrate is reported. Optical transmission characteristics of the partially exposed polymer dispersed liquid crystal thin film in response to an air flow induced shear stress field reveal its potential as a sensor for gas flow and boundary layer investigations.

  1. The AMINO experiment: methane photolysis under Solar VUV irradiation on the EXPOSE-R facility of the International Space Station

    NASA Astrophysics Data System (ADS)

    Carrasco, Nathalie; Cottin, Hervé; Cloix, Mégane; Jérome, Murielle; Bénilan, Yves; Coll, Patrice; Gazeau, Marie-Claire; Raulin, François; Saiagh, Kafila; Chaput, Didier

    2015-01-01

    The scientific aim of the present campaign is to study the whole chain of methane photo-degradation, as initiated by Solar vacuum-ultraviolet irradiation in Titan's atmosphere. For this purpose, the AMINO experiment on the EXPOSE-R mission has loaded closed cells for gas-phase photochemistry in space conditions. Two different gas mixtures have been exposed, named Titan 1 and Titan 2, involving both N2-CH4 gas mixtures, without and with CO2, respectively. CO2 is added as a source of reactive oxygen in the cells. The cell contents were analysed thanks to infrared absorption spectroscopy, gas chromatography and mass spectrometry. Methane consumption leads to the formation of saturated hydrocarbons, with no detectable influence of CO2. This successful campaign provides a first benchmark for characterizing the whole methane photochemical system in space conditions. A thin film of tholin-like compounds appears to form on the cell walls of the exposed cells.

  2. Neurodevelopmental outcomes in HIV-exposed-uninfected children versus those not exposed to HIV.

    PubMed

    Kerr, Stephen J; Puthanakit, Thanyawee; Vibol, Ung; Aurpibul, Linda; Vonthanak, Sophan; Kosalaraksa, Pope; Kanjanavanit, Suparat; Hansudewechakul, Rawiwan; Wongsawat, Jurai; Luesomboon, Wicharn; Ratanadilok, Kattiya; Prasitsuebsai, Wasana; Pruksakaew, Kanchana; van der Lugt, Jasper; Paul, Robert; Ananworanich, Jintanat; Valcour, Victor

    2014-01-01

    Human immunodeficiency virus (HIV)-negative children born to HIV-infected mothers may exhibit differences in neurodevelopment (ND) compared to age- and gender-matched controls whose lives have not been affected by HIV. This could occur due to exposure to HIV and antiretroviral agents in utero and perinatally, or differences in the environment in which they grow up. This study assessed neurodevelopmental outcomes in HIV-exposed uninfected (HEU) and HIV-unexposed uninfected (HUU) children enrolled as controls in a multicenter ND study from Thailand and Cambodia. One hundred sixty HEU and 167 HUU children completed a neurodevelopmental assessment using the Beery Visual Motor Integration (VMI) test, Color Trails, Perdue Pegboard, and Child Behavior Checklist (CBCL). Thai children (n = 202) also completed the Wechsler Intelligence Scale (IQ) and Stanford-Binet II memory tests. In analyses adjusted for caregiver education, parent as caregiver, household income, age, and ethnicity, statistically significant lower scores were seen on verbal IQ (VIQ), full-scale IQ (FSIQ), and Binet Bead Memory among HEU compared to HUU. The mean (95% CI) differences were -6.13 (-10.3 to -1.96), p = 0.004; -4.57 (-8.80 to -0.35), p = 0.03; and -3.72 (-6.57 to -0.88), p = 0.01 for VIQ, FSIQ, and Binet Bead Memory, respectively. We observed no significant differences in performance IQ, other Binet memory domains, Color Trail, Perdue Pegboard, Beery VMI, or CBCL test scores. We conclude that HEU children evidence reductions in some neurodevelopmental outcomes compared to HUU; however, these differences are small and it remains unclear to what extent they have immediate and long-term clinical significance. PMID:24878112

  3. Assessment of oxidative stress in Rhamdia quelen exposed to agrichemicals.

    PubMed

    Ferreira, Daiane; da Motta, Adriana Costa; Kreutz, Luiz Carlos; Toni, Cândida; Loro, Vânia Lucia; Barcellos, Leonardo José Gil

    2010-05-01

    Due to the proximity of crop and fish culture areas, some agrichemicals that could be harmful for fish could enter into fishponds by different ways, such as by leaching through rain. Rhamdia quelen (Teleostei) were exposed to sublethal concentrations of methyl parathion (MP), a glyphosate based herbicide (Gly), and tebuconazole (Teb). The liver of R. quelen exposed to MP and Teb showed enhanced levels of thiobarbituric acid reactive substances (TBARS), higher than in the control fish (56% and 59%, respectively). In contrast, Gly did not alter the TBARS generation. The protein carbonyl content increased only in fish exposed to Teb. Fish exposed to the three agrichemicals showed a significant decrease of catalase activity (52%, 48%, and 67%, respectively) and increased glutathione-S-transferase (57%, 46%, and 160%, respectively) activity. Fish exposed to MP, Gly, and Teb showed higher reduced glutathione (151%, 472%, and 130%, respectively, when compared with the control levels) and ascorbic acid concentrations (121%, 102%, and 184%, respectively),while the non-protein thiol content increased only in R. quelen exposed to tebuconazole. Fish exposed to MP and Teb showed several pathological changes in the liver, including hepatocyte degeneration and bile stagnation. The present work reports for the first time the toxicity of the pesticide MP and the fungicide Teb in R. quelen, and as in other works, suggests the relatively lower liver toxicity of Gly for fish. The data presented herein demonstrate that sublethal concentrations of MP and Teb cause changes in oxidative stress parameters as well as hepatic cell injuries in R. quelen, and that these parameters have the potential to be developed as bioindicators of exposure to these agrichemicals.

  4. Cardiovascular effects in viscose rayon workers exposed to carbon disulfide.

    PubMed

    Kotseva, K; Braeckman, L; De Bacquer, D; Bulat, P; Vanhoorne, M

    2001-01-01

    The objectives of this study were to investigate the cardiovascular effects in workers currently exposed to carbon disulfide (CS2) below the threshold limit value (TLV) of 31 mg/m3 and to determine the prevalence of coronary heart disease (CHD) after long-term exposure. 172 men (91 workers exposed to CS2 in a viscose rayon factory and 81 referent workers) were examined using a medical and job history questionnaire, Rose's questionnaire, and electrocardiography at rest, and by measuring blood pressure and serum lipids and lipoproteins. Personal exposures were monitored simultaneously with active sampling and findings were analyzed according to the NIOSH 1600 method. As a result of technical and organizational improvements, personal CS2 exposures were well below the TLV (5.4-13.02 mg/m3). No significant effect of CS2 on blood pressure or lipids (total cholesterol, HDL and LDL cholesterol, triglycerides, and apolipoproteins AI and B) was found, even after allowance for confounding factors. The prevalence of CHD (ECG abnormalities and chest pain) was higher in the viscose rayon workers than in the workers with no exposure but reached statistical significance for men with exposure histories often years and more only (cumulative CS9 index > or = 150 mg/m3, the most highly exposed group). The findings suggest that the coronary risk is increased in workers previously exposed to high CS2 concentrations but not in those exposed to CS2 levels below the current TLV. PMID:11210016

  5. Effects on LDEF exposed copper film and bulk

    NASA Technical Reports Server (NTRS)

    Peters, Palmer N.; Gregory, John C.; Christl, Ligia C.; Raikar, Ganesh N.

    1991-01-01

    Two forms of copper were exposed to the Long Duration Exposure Facility (LDEF) Mission 1 environment: a copper film, initially 74.2 plus or minus 1.1 nm thick sputter coated on a fused silica flat and a bulk piece of oxygen-free, high conductivity (OFHC) copper. The optical density of the copper film changed from 1.33 to 0.70 where exposed, and the film thickness increased to 106.7 plus or minus 0.5 nm where exposed. The exposed area appears purple by reflection and green by transmission for the thin film and maroon color for the bulk copper piece. The exposed areas increased in thickness, but only increase in the thickness of the thin film sample could be readily measured. The increase in film thickness is consistent with the density changes occurring during conversion of copper to an oxide. However, we have not been able to confirm appreciable conversion to an oxide by x-ray diffraction studies. We have not yet subjected the sample to e-beams or more abusive investigations out of concern that the film might be modified.

  6. Characterization of the phosphatidylserine-exposing subpopulation of sickle cells.

    PubMed

    de Jong, K; Larkin, S K; Styles, L A; Bookchin, R M; Kuypers, F A

    2001-08-01

    Phosphatidylserine (PS), exclusively present in the inner monolayer of the normal red blood cell (RBC) membrane, is exposed in subpopulations of sickle cells. PS-exposing RBCs were found predominantly among the densest and the very light sickle cells. Within the light RBC fraction, PS exposure was found on reticulocytes, transferrin receptor-expressing reticulocytes, and mature RBCs. The last subset contained low-density valinomycin-resistant RBCs, previously shown to have high Na(+) and low K(+) content. This subpopulation contained the highest percentage of PS-exposing cells. The PS-exposing sickle cells did not show the sustained high cytosolic Ca(++) levels that have been shown to activate scramblase activity. Data from this study indicate that PS exposure can occur at different stages in the life of the sickle RBC and that it correlates with the loss of aminophospholipid translocase activity, the only common denominator of the PS-exposing cells. The additional requirement of scramblase activation may occur during transient increases in cytosolic Ca(++). (Blood. 2001;98:860-867)

  7. Cardiovascular effects in viscose rayon workers exposed to carbon disulfide.

    PubMed

    Kotseva, K; Braeckman, L; De Bacquer, D; Bulat, P; Vanhoorne, M

    2001-01-01

    The objectives of this study were to investigate the cardiovascular effects in workers currently exposed to carbon disulfide (CS2) below the threshold limit value (TLV) of 31 mg/m3 and to determine the prevalence of coronary heart disease (CHD) after long-term exposure. 172 men (91 workers exposed to CS2 in a viscose rayon factory and 81 referent workers) were examined using a medical and job history questionnaire, Rose's questionnaire, and electrocardiography at rest, and by measuring blood pressure and serum lipids and lipoproteins. Personal exposures were monitored simultaneously with active sampling and findings were analyzed according to the NIOSH 1600 method. As a result of technical and organizational improvements, personal CS2 exposures were well below the TLV (5.4-13.02 mg/m3). No significant effect of CS2 on blood pressure or lipids (total cholesterol, HDL and LDL cholesterol, triglycerides, and apolipoproteins AI and B) was found, even after allowance for confounding factors. The prevalence of CHD (ECG abnormalities and chest pain) was higher in the viscose rayon workers than in the workers with no exposure but reached statistical significance for men with exposure histories often years and more only (cumulative CS9 index > or = 150 mg/m3, the most highly exposed group). The findings suggest that the coronary risk is increased in workers previously exposed to high CS2 concentrations but not in those exposed to CS2 levels below the current TLV.

  8. Factors Influencing the Intended Likelihood of Exposing Sexual Infidelity.

    PubMed

    Kruger, Daniel J; Fisher, Maryanne L; Fitzgerald, Carey J

    2015-08-01

    There is a considerable body of literature on infidelity within romantic relationships. However, there is a gap in the scientific literature on factors influencing the likelihood of uninvolved individuals exposing sexual infidelity. Therefore, we devised an exploratory study examining a wide range of potentially relevant factors. Based in part on evolutionary theory, we anticipated nine potential domains or types of influences on the likelihoods of exposing or protecting cheaters, including kinship, strong social alliances, financial support, previous relationship behaviors (including infidelity and abuse), potential relationship transitions, stronger sexual and emotional aspects of the extra-pair relationship, and disease risk. The pattern of results supported these predictions (N = 159 men, 328 women). In addition, there appeared to be a small positive bias for participants to report infidelity when provided with any additional information about the situation. Overall, this study contributes a broad initial description of factors influencing the predicted likelihood of exposing sexual infidelity and encourages further studies in this area.

  9. Decision support for subjects exposed to heat stress.

    PubMed

    Seeberg, Trine M; Vardøy, Astrid-Sofie B; Taklo, Maaike M Visser; Austad, Hanne Opsahl

    2013-03-01

    The physiological and activity strain index (PASI) has been developed to improve the online decision support for workers exposed to heat stress. Fire fighters (smoke divers) which are exposed to both heat-stress and high-risk situations have been used as test case. PASI combines a modified version of the relatively well-known physiological strain index (PSI) with activity data from accelerometers. The algorithm has been developed based on tests in a laboratory, and it has been verified in two field tests performed by smoke divers exposed to heat stress. The verification demonstrates that it is possible to distinguish between high- and low-risk situations when data from accelerometers are added to the situation analysis. This indicates that PASI can contribute to an improved risk assessment and online decision support for smoke divers compared to using PSI alone. PMID:24235112

  10. Analysis of a space-exposed thermoplastic resin

    NASA Technical Reports Server (NTRS)

    Young, Philip R.; Slemp, Wayne S.; Siochi, Emilie J.; Davis, Judith R. J.

    1992-01-01

    The chemical characterization of a thermoplastic resin exposed to the low Earth orbit (LEO) environment for 10 months and for 5.8 years is reported. The resin, processed as a thick film and as a matrix for a graphite fiber reinforced composite, few exposed in the RAM direction on the NASA Long Duration Exposure Facility (LDEF). Differences attributable to environmental exposure were detected in infrared spectra and in various molecular weight parameters of film after 10 months in LEO. Those effects were not as apparent in composites after 5.8 years in LEO. Increased exposure to atomic oxygen toward the end of the LDEF mission probably scrubbed these effects from specimens exposed for 5.8 years. The intent of this study is to increase our fundamental understanding of space environmental effects on polymeric materials and to develop a benchmark for enhancing our methodology for and understanding of the ground-based simulation of space environmental effects.

  11. Medical surveillance of the lead exposed worker. Current guidelines.

    PubMed

    Hipkins, K L; Materna, B L; Kosnett, M J; Rogge, J W; Cone, J E

    1998-07-01

    1. The "lead standards" established by OSHA for general industry in 1978 and the construction industry in 1993 require employers and clinicians to follow very specific guidelines for protecting lead exposed workers. Depending on the level of exposure, medical surveillance may be legally required. 2. Lead affects multiple body systems and can cause permanent damage. Low level exposures that in the past were thought safe are now considered hazardous as new information emerges about the toxicity of lead. 3. Lead poisoning, if undetected, often results in misdiagnosis and costly care. Adults are exposed to lead in many different workplace settings. All clinicians caring for lead exposed workers need to be informed about the health effects of lead, employer and physician responsibilities, and worker rights. 4. Occupational and environmental health nurses can help identify workers at risk and prevent lead poisoning by education and early intervention through collaboration with the workers, the employer, the company physician, and other health and safety professionals.

  12. Semen quality in workers exposed to 2-ethoxyethanol.

    PubMed

    Ratcliffe, J M; Schrader, S M; Clapp, D E; Halperin, W E; Turner, T W; Hornung, R W

    1989-06-01

    To evaluate whether long term exposure to 2-ethoxyethanol (2EE) may affect semen quality, a cross sectional study was conducted among men exposed to 2EE used as a binder slurry in a metal castings process. Full shift breathing zone exposures to 2EE ranged from non-detectable to 24 ppm (geometric mean 6.6 ppm). Because of the potential for substantial absorption of 2EE through skin exposure, urine measurements of the metabolite of 2EE, 2-ethoxyacetic acid (2EAA) were conducted, showing levels of 2EAA ranging from non-detectable to 163 mg 2EAA/g creatinine. Only 37 exposed men (50% participation) and 39 non-exposed comparison (26% participation) from elsewhere in the plant provided a sperm sample. A questionnaire to determine personal habits, and medical and work histories, and a physical examination of the urogenital tract were also administered. The average sperm count per ejaculate among the workers exposed to 2EE was significantly lower than that of the unexposed group (113 v 154 million sperm per ejaculate respectively; p = 0.05) after consideration of abstinence, sample age, subjects' age, tobacco, alcohol and caffeine use, urogenital disorders, fever, and other illnesses. The mean sperm concentrations of the exposed and unexposed groups did not significantly differ from each other (44 and 53 million/ml respectively). No effect of exposure to 2EE on semen volume, sperm viability, motility, velocity, and normal morphology or testicular volume was detected, although some differences in the proportion of abnormal sperm shapes were observed. These data suggest that there may be an effect of 2EE on sperm count among these workers, although the possibility that other factors may be affecting the semen quality in both exposed and unexposed men in this population or that the results reflect bias introduced by the low participation rates cannot be excluded. PMID:2818974

  13. The EXPOSE-E Mission on the ISS

    NASA Astrophysics Data System (ADS)

    Rabbow, Elke; Rettberg, Petra; Panitz, Corinna; Reitz, Guenther

    The International Space Station ISS provides a variety of external research platforms for ex-periments aiming at the utilization of space parameters like vacuum, temperature oscillation, extraterrestrial UV and ionizing radiation. For 1.5 years the astrobiological experimental ESA facility EXPOSE-E was accommodated on the EuTEF Platform on one of the external balconies of the Columbus Module with 5 exobio-logical and 3 radiation experiments, exposing the chemical, biological and dosimetric samples to the harsh space environment. The main interest of the experiments was to increase our knowledge on the origin, evolution and distribution of life, on Earth and possibly beyond. The biological experiments investigated resistance and adaptation of organisms like bacteria, Achaea, fungi, lichens and plant seeds to extreme environmental conditions and underlying mechanisms like DNA repair. The organic chemical experiments analyse chemical reactions triggered by the extraterrestrial environment, especially short wavelength UV radiation, to better understand prebiotic chemistry. The facility is optimized to allow exposure of biologi-cal specimen and material samples under a variety of conditions, using optical filter systems. Environmental parameters like temperature and radiation were regularly recorded and down linked by telemetry. The exposure facility EXPOSE-E itself and the accommodated experiments and samples are introduced. A complete Mission overview of this recent long term astrobiological experiment is presented: from the sample preparation and launch to the landing and sample retrieval. Mission data and an assessment of the impacting space parameters during the mission are given. After EXPOSE-E, the sister facility EXPOSE-R was launched and still is in space. A short status information and outlook on this second astrobiological Mission will be included.

  14. Survival of Spores of Trichoderma longibrachiatum in Space: data from the Space Experiment SPORES on EXPOSE-R

    NASA Astrophysics Data System (ADS)

    Neuberger, Katja; Lux-Endrich, Astrid; Panitz, Corinna

    2015-01-01

    In the space experiment `Spores in artificial meteorites' (SPORES), spores of the fungus Trichoderma longibrachiatum were exposed to low-Earth orbit for nearly 2 years on board the EXPOSE-R facility outside of the International Space Station. The environmental conditions tested in space were: space vacuum at 10-7-10-4 Pa or argon atmosphere at 105 Pa as inert gas atmosphere, solar extraterrestrial ultraviolet (UV) radiation at λ > 110 nm or λ > 200 nm with fluences up to 5.8 × 108 J m-2, cosmic radiation of a total dose range from 225 to 320 mGy, and temperature fluctuations from -25 to +50°C, applied isolated or in combination. Comparable control experiments were performed on ground. After retrieval, viability of spores was analysed by two methods: (i) ethidium bromide staining and (ii) test of germination capability. About 30% of the spores in vacuum survived the space travel, if shielded against insolation. However, in most cases no significant decrease was observed for spores exposed in addition to the full spectrum of solar UV irradiation. As the spores were exposed in clusters, the outer layers of spores may have shielded the inner part. The results give some information about the likelihood of lithopanspermia, the natural transfer of micro-organisms between planets. In addition to the parameters of outer space, sojourn time in space seems to be one of the limiting parameters.

  15. Lung cancer in rats exposed to fibrogenic dusts

    SciTech Connect

    Holland, L.M.; Wilson, J.S.; Tillery, M.I.; Smith, D.M.

    1984-01-01

    Fischer-344 rats were exposed to quartz dusts and to quartz-bearing oil shale dusts in long-term inhalation studies. Aerosol concentrations of 12 mg/m/sup 3/ and 152-176 mg/m/sup 3/ for quartz and shale dusts, respectively, were used in exposure regimens lasting up to two years. Pulmonary fibrosis was observed in most animals surviving beyond 400 days. Adenocarcinomas and epidermoid carcinomas of the lung were observed in animals from all exposure groups, including those exposed to quartz alone. The pulmonary tumors were a late effect, with the earliest lung tumor being observed after 651 days. 13 references, 10 figures, 4 tables.

  16. Fibrin sealant-assisted revision of the exposed Ahmed tube.

    PubMed

    Choudhari, Nikhil S; Neog, Aditya; Latka, Supriya; Srinivasan, Bhaskar

    2015-01-01

    Tube exposure is a known complication of Ahmed glaucoma valve (AGV) implantation. Repair of the exposed tube is not easy. A 42-year-old monocular aphakic male had undergone retinal detachment repair with placement of an episcleral-encircling band followed by implantation of AGV. He presented to the clinic on routine review with exposure of the shunt tube. The complication was managed by placing scleral and conjunctival grafts over the exposed tube using a fibrin adhesive (Tisseel kit; Baxter AG, Vienna, Austria). The novel use of the fibrin sealant in the repair of AGV tube exposure was for better graft-integration.

  17. Fibrin Sealant-Assisted Revision of the Exposed Ahmed Tube

    PubMed Central

    Choudhari, Nikhil S.; Neog, Aditya; Latka, Supriya; Srinivasan, Bhaskar

    2015-01-01

    Tube exposure is a known complication of Ahmed glaucoma valve (AGV) implantation. Repair of the exposed tube is not easy. A 42-year-old monocular aphakic male had undergone retinal detachment repair with placement of an episcleral-encircling band followed by implantation of AGV. He presented to the clinic on routine review with exposure of the shunt tube. The complication was managed by placing scleral and conjunctival grafts over the exposed tube using a fibrin adhesive (Tisseel kit; Baxter AG, Vienna, Austria). The novel use of the fibrin sealant in the repair of AGV tube exposure was for better graft-integration. PMID:25624685

  18. Study of indium tin oxide films exposed to atomic axygen

    NASA Technical Reports Server (NTRS)

    Snyder, Paul G.; De, Bhola N.; Woollam, John A.; Coutts, T. J.; Li, X.

    1989-01-01

    A qualitative simulation of the effects of atomic oxygen has been conducted on indium tin oxide (ITO) films prepared by dc sputtering onto room-temperature substrates, by exposing them to an RF-excited oxygen plasma and characterizing the resulting changes in optical, electrical, and structural properties as functions of exposure time with ellipsometry, spectrophotometry, resistivity, and X-ray measurements. While the films thus exposed exhibit reduced resistivity and optical transmission; both of these effects, as well as partial crystallization of the films, may be due to sample heating by the plasma. Film resistivity is found to stabilize after a period of exposure.

  19. Organic samples produced by ion bombardment of ices for the EXPOSE-R2 mission on the International Space Station

    NASA Astrophysics Data System (ADS)

    Baratta, G. A.; Chaput, D.; Cottin, H.; Fernandez Cascales, L.; Palumbo, M. E.; Strazzulla, G.

    2015-12-01

    We describe the preparation and characterization (by UV-vis-IR spectroscopy) of a set of organic samples, stable at room temperature and above, that are part of the experiment "Photochemistry on the Space Station (PSS)" planned to be enclosed in the EXPOSE-R2 mission, which will be conducted on the EXPOSE-R facility. The core facility is placed outside the International Space Station (ISS) on the Universal Platform D (URM-D platform) of the Russian module Zvezda. The organic materials are prepared in the Catania laboratory after 200 keV He+ irradiation of icy mixtures, namely N2:CH4:CO deposited at 16 K on MgF2 windows furnished by the European Space Agency. It is widely accepted that such a kind of materials produced by energetic processing are representative of organic material in some astrophysical environments as comets. Once expelled from comets these materials are exposed to solar radiation during their interplanetary journey before they eventually land on Earth and other planetary objects where they might give a contribution to the chemical and pre-biotical evolution. In particular our residues contain different chemical groups, including triple CN bonds that are considered relevant to pre-biotic chemistry. Therefore the samples will be exposed, for several months, to the solar ultraviolet photons that are a major source of energy to initiate chemical evolution in the solar system. This will allow analysis of their destruction or modification and evaluation of their lifetime in the interplanetary medium. The samples have three different thicknesses that will allow estimation of the depth profile of destruction. This experiment overcomes the limits of ground tests which do not reproduce exactly the space parameters.

  20. TRANSCRIPTIONAL RESPONSES OF MOUSE EMBRYO CULTURES EXPOSED TO BROMOCHLOROACETIC ACID

    EPA Science Inventory

    Transcriptional responses of mouse embryo cultures exposed to bromochloroacetic acid

    Edward D. Karoly?*, Judith E. Schmid* and E. Sidney Hunter III*
    ?Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina and *Reproductive Tox...

  1. Semen study of papaya workers exposed to ethylene dibromide

    SciTech Connect

    Ratcliffe, J.M.; Schrader, S.M.; Steenland, K.; Clapp, D.; Turner, T.

    1984-01-01

    A cross sectional semen and cytogenetic study was performed on male workers exposed to ethylene-dibromide (EDB) in the papaya fumigation industry in Hawaii. Semen analyses were conducted on 46 men in six fumigation facilities with an average length of employment of 5 years and airborne exposures to EDB ranging from 16 to 213 parts per billion. Statistically significant decreases in sperm count per ejaculate and the percentage of viable and motile sperm and increases in the proportion of specific morphological abnormalities were observed among exposed men when compared with controls. Semen volume and sperm concentration were also lower in the exposed group. No effect of exposure to EDB on sperm velocity, the overall proportion of sperm with normal morphology or YFF bodies was noted. The authors conclude that based on the decreases in sperm count, viability and motility and increases in certain types of morphological abnormalities among workers exposed to EDB, EDB may increase the risk of reproductive impairment in workers at exposure levels near the NIOSH recommended limit of 45 parts per billion and far below the current OSHA standard of 20 parts per million.

  2. VIEW OF STATION LEARY FACING NORTH SHOWING EXPOSED EXTERIOR FRONT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF STATION LEARY FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT INCLUDING POST 1920 DOORWAY ALTERATIONS, SANDSTONE FLANK-WALLS ARE VISIBLE AT REAR SIDES - White's Point Reservation, Base End Stations, B"3, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

  3. VIEW OF STATION SAXTON FACING NORTH SHOWING EXPOSED EXTERIOR FRONT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF STATION SAXTON FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT, SANDSTONE FLANK-WALLS ARE VISIBLE AT REAR SIDES - White's Point Reservation, Base End Stations, B"2, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

  4. VIEW OF STATION OSGOOD FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF STATION OSGOOD FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT AND LEFT SIDE OF THE CONCRETE CONCEALMENT, SANDSTONE FLANKWALL IS VISIBLE AT LEFT REAR - White's Point Reservation, Base End Stations, B"5, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

  5. VIEW OF STATION BARLOW SHOWING EXPOSED EXTERIOR FRONT AND LEFT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF STATION BARLOW SHOWING EXPOSED EXTERIOR FRONT AND LEFT SIDE OF THE CONCRETE CONCEALMENT WITH SANDSTONE FLANK-WALL FRAGMENT, FACING NORTHWEST - White's Point Reservation, Base End Stations, B"1, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

  6. VIEW OF STATION BARLOW FACING NORTH SHOWING EXPOSED EXTERIOR FRONT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF STATION BARLOW FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT, SANDSTONE FLANK-WALL FRAGMENT VISIBLE AT LEFT REAR - White's Point Reservation, Base End Stations, B"1, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

  7. 2. VIEW OF STATION FARLEY FACING NORTH SHOWING EXPOSED EXTERIOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF STATION FARLEY FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT, SANDSTONE FLANK-WALLS ARE VISIBLE AT REAR SIDES. - White's Point Reservation, Base End Stations, B"6, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

  8. VIEW OF STATION LEARY FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF STATION LEARY FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT AND LEFT SIDE OF THE CONCRETE CONCEALMENT, SANDSTONE FLANKWALL IS VISIBLE AT LEFT REAR - White's Point Reservation, Base End Stations, B"3, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

  9. VIEW OF STATION OSGOOD FACING NORTH SHOWING EXPOSED EXTERIOR FRONT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF STATION OSGOOD FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT INCLUDING POST 1920 DOORWAY ALTERATIONS, SANDSTONE FLANK-WALLS ARE VISIBLE AT REAR SIDES - White's Point Reservation, Base End Stations, B"5, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

  10. 3. VIEW OF STATION PARLEY FACING NORTHWEST, SHOWING EXPOSED EXTERIOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW OF STATION PARLEY FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT AND LEFT SIDE OF THE CONCRETE CONCEALMENT, SANDSTONE FLANKWALL IS VISIBLE AT LEFT REAR. - White's Point Reservation, Base End Stations, B"6, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

  11. 7 CFR 27.33 - Exposing of samples for classification.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Exposing of samples for classification. 27.33 Section 27.33 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND...

  12. Genetic Predisposition for Dermal Problems in Hexavalent Chromium Exposed Population

    PubMed Central

    Sharma, Priti; Bihari, Vipin; Agarwal, Sudhir K.; Goel, Sudhir K.

    2012-01-01

    We studied the effect of genetic susceptibility on hexavalent chromium induced dermal adversities. The health status of population was examined from the areas of Kanpur (India) having the elevated hexavalent chromium levels in groundwater. Blood samples were collected for DNA isolation to conduct polymorphic determination of genes, namely: NQO1 (C609T), hOGG1 (C1245G), GSTT1, and GSTM1 (deletion). Symptomatic exposed subjects (n = 38) were compared with asymptomatic exposed subjects (n = 108) along with asymptomatic controls (n = 148) from a non contaminated reference community. Exposed symptomatic group consisted of 36.8% subjects who were GSTM1 null genotyped as compared to asymptomatic where only 19.4% subjects were null. The exposed subjects with GSTM1 null genotype were more susceptible to dermal adversities in comparison with wild genotyped subjects (OR = 2.42; 95% CI = 1.071–5.451). Age, smoking, gender or duration of residence were not found to have any confounding effect towards this association. Association with other genes was not statistically significant, nonetheless, possible contribution by these genes cannot be ruled out. In conclusion, variation in the polymorphic status of GSTM1 gene may influence dermal outcomes among residents from Cr(VI) contaminated areas. Further studies are therefore, needed to examine these observations among different population groups. PMID:22919465

  13. 29. VIEW WEST TOWARDS KALAWAO OF PIPELINE, EXPOSED AT LOWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. VIEW WEST TOWARDS KALAWAO OF PIPELINE, EXPOSED AT LOWER LEFT. CAT TRACKS, MADE BY THE CONSTRUCTION/MAINTENANCE VEHICLES, CAN BE SEEN ALONG BOULDER BEACH - Kalaupapa Water Supply System, Waikolu Valley to Kalaupapa Settlement, Island of Molokai, Kalaupapa, Kalawao County, HI

  14. Profiles of Reactivity in Cocaine-Exposed Children

    ERIC Educational Resources Information Center

    Schuetze, Pamela; Molnar, Danielle S.; Eiden, Rina D.

    2012-01-01

    This study explored the possibility that specific, theoretically consistent profiles of reactivity could be identified in a sample of cocaine-exposed infants and whether these profiles were associated with a range of infant and/or maternal characteristics. Cluster analysis was used to identify distinct groups of infants based on physiological,…

  15. Youth Exposed to Violence: The Role of Protective Factors

    ERIC Educational Resources Information Center

    Howard, Kimberly A. S.; Budge, Stephanie L.; McKay, Kevin M.

    2010-01-01

    Using a sample of 174 inner-city urban high school students, this study examined the degree to which family and peer support would moderate the negative impact of exposure to violence on academic performance, symptoms of distress, and persistence intentions. Over 94% of the students reported having been exposed to at least one form of community…

  16. Multidimensional Resilience in Urban Children Exposed to Community Violence.

    ERIC Educational Resources Information Center

    O'Donnell, Deborah A.; Schwab-Stone, Mary E.; Muyeed, Adaline Z.

    2002-01-01

    This study examined how parent, school, and peer support differentially affected resilience among urban sixth-, eighth-, and tenth-graders. Findings indicated that both parent and school support factors positively related to resilience in children who had been exposed to community violence; however, peer support negatively related to resilience in…

  17. RESPIRATORY DAMAGE IN CHILDREN EXPOSED TO URBAN POLLUTION

    EPA Science Inventory


    Southwest Metropolitan Mexico City (SWMMC) children are chronically exposed to complex mixtures of air pollutants. In a cross-sectional arm of our study, we investigated the association between exposure to SWMMC atmosphere and nasal abnormalities, hyperinflation, and intersti...

  18. 18. William E. Barrett, Photographer, August 1975. EXPOSED VIEW OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. William E. Barrett, Photographer, August 1975. EXPOSED VIEW OF LOWER PULLEYS OF LEFT-HAND MILL. LOWER LEFT IS BAND SAW PULLEY. UPPER LEFT IS TENSION WHEEL. LARGE PULLEY ON RIGHT IS DRIVE WHEEL FROM POWER SOURCE. - Meadow River Lumber Company, Highway 60, Rainelle, Greenbrier County, WV

  19. 12. A LONG RUN OF EXPOSED TOP SURFACE, NORTH TRAINING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. A LONG RUN OF EXPOSED TOP SURFACE, NORTH TRAINING WALL, ABOUT 1,500 FEET EAST OF THE FEDERAL CHANNEL MOUTH. VIEW TO WEST, TOWARD SAN FRANCISCO. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  20. Preventing Alcohol-Exposed Pregnancy among American-Indian Youth

    ERIC Educational Resources Information Center

    Jensen, Jamie; Kenyon, DenYelle Baete; Hanson, Jessica D.

    2016-01-01

    Research has determined that the prevention of alcohol-exposed pregnancies (AEP) must occur preconceptually, either by reducing alcohol intake in women planning pregnancy or at risk for becoming pregnant, or by preventing pregnancy in women drinking at risky levels. One such AEP prevention programme with non-pregnant American-Indian (AI) women is…

  1. Embryo- and fetotoxicity of chromium in pregestationally exposed mice

    SciTech Connect

    Junaid, M.; Murthy, R.C.; Saxena, D.K.

    1996-10-01

    Chromium, an essential element in the human body required for proper carbohydrate, protein, and fat metabolism, is reported to impair gestational development of offspring of workers chronically exposed to this metal in the work place. Workers in chromium based industries can be exposed to concentrations two orders of magnitude higher than the general population. Among the general population, residents living near chromate production sites may be exposed to high levels of chromium (VI) in air or to elevated levels (40 - 50,000 ppm) of chromium in effluents. Shmitova reported afterbirth and puerperal hemorrhages in women industrially exposed to this metal and observed high chromium levels in blood and urine of pregnant women and in fetal and cord blood. Chromium readily passes the placental barrier and reaches the growing fetus. Exposure of mice to chromium during various gestational periods resulted in embryo and fetotoxic effects. This study looks at the role of body chromium accumulated pregestationally on embryo and fetal development and its subsequent transfer to feto-placental sites. 25 refs., 3 tabs.

  2. A pill to treat people exposed to radioactive materials

    ScienceCinema

    Abergel, Rebecca

    2016-07-12

    Berkeley Lab's Rebecca Abergel discusses "A pill to treat people exposed to radioactive materials" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas. Go here to watch the entire event with all 8 speakers:

  3. A pill to treat people exposed to radioactive materials

    SciTech Connect

    Abergel, Rebecca

    2013-10-31

    Berkeley Lab's Rebecca Abergel discusses "A pill to treat people exposed to radioactive materials" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas. Go here to watch the entire event with all 8 speakers:

  4. Cardiovascular response of rats exposed to 60-Hz electric fields

    SciTech Connect

    Hilton, D.I.; Phillips, R.D.

    1980-01-01

    Recently, it has been reported that exposure to high-strength electric fields can influence electrocardiogram (ECG) patterns, heart rates, and blood pressures in various species of animals. Our studies were designed to evaluate these reported effects and to help clarify some of the disagreement present in the literature. Various cardiovascular variables were measured in Sprague-Dawley rats exposed or sham-exposed to 60-Hz electric fields at 80 to 100 kV/m for periods up to four months. No significant differences in heart rates, ECG patterns, blood pressures, or vascular reactivity were observed between exposed and sham-exposed rats after 8 hours, 40 hours, 1 month, or 4 months of exposure. Our studies cannot be directly compared to the work of other investigators because of differences in animal species and electric-field characteristics. However, our failure to detect any cardiovascular changes may have been the result of (1) eliminating secondary field effects such as shocks, audible noise, corona, and ozone; (2) minimizing steady-state microcurrents between the mouth of the animal and watering devices; and (3) minimizing electric-field-induced vibration of the electrodes and animal cages.

  5. Urologic cancer risks for veterans exposed to Agent Orange.

    PubMed

    Hoenemeyer, Lori A

    2013-01-01

    Agent Orange, an herbicide widely used during the Vietnam War, has been linked to various health risks, including urologic malignancy. Exposed veterans are at risk for prostate cancer and may be entitled to compensation if diagnosed with prostate cancer. Current research studies are aimed at mitigating prostate dysplasia and prostate cancer PMID:23734554

  6. How Permanent Is Permanent Placement for Substance-Exposed Infants?

    ERIC Educational Resources Information Center

    Twomey, Jean E.; Lester, Barry M.

    2007-01-01

    The authors describe a study of families in the Family Drug Treatment Court (FTDC), an effort to promote permanent placement for substance-exposed infants within time requirements mandated by the 1997 Adoption and Safe Families Act (ASFA). The purpose of the study was to evaluate parent functioning after FTDC involvement, infant developmental…

  7. A Care Coordination Program for Substance-Exposed Newborns

    ERIC Educational Resources Information Center

    Twomey, Jean E.; Caldwell, Donna; Soave, Rosemary; Fontaine, Lynne Andreozzi; Lester, Barry M.

    2011-01-01

    The Vulnerable Infants Program of Rhode Island (VIP-RI) was established as a care coordination program to promote permanency for substance-exposed newborns in the child welfare system. Goals of VIP-RI were to optimize parents' opportunities for reunification and increase the efficacy of social service systems involved with families affected by…

  8. EXPOSED BEAM AND VINYL VENTED SOFFIT MATERIAL IN THE CARPORT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXPOSED BEAM AND VINYL VENTED SOFFIT MATERIAL IN THE CARPORT ON THE SOUTHEAST SIDE OF THE UNIT - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

  9. Proteomic Profiling of Bladders from Mice Exposed with Sodium Arsenite

    EPA Science Inventory

    Arsenic, an environmental contaminant, has been linked with cancer of the bladder in humans. To study the mode of action of arsenic, female CH3 mice were exposed to 85 ppm sodium arsenite in their drinking water for 30 days. Following the exposure a comparative proteomic analysis...

  10. 18. INTERIOR OF ROOM 106 LOOKING SOUTHEAST. EXPOSED BEAM AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. INTERIOR OF ROOM 106 LOOKING SOUTHEAST. EXPOSED BEAM AT CEILING IS PAINTED. FLOOR IS VINYL COMPOSITION TILE. WALLS AND CEILING ARE PAINTED GYPSUM BOARD. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

  11. Detail, oblique view to northeast atop building 935 showing exposed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail, oblique view to northeast atop building 935 showing exposed roof sections of buildings 934 (center) and 933 (left), 90 mm lens. - Travis Air Force Base, Nuclear Weapons Assembly Plant 3, W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  12. Out-of-Home Placement of Children Exposed to Violence

    ERIC Educational Resources Information Center

    Harpaz-Rotem, Ilan; Berkowitz, Steven; Marans, Steven; Murphy, Robert A.; Rosenheck, Robert A.

    2008-01-01

    There is growing concern about the increasing number of children in the USA who are exposed to community violence and the need to remove some of them from their families. This study examines risk factors for out-of-home placement among a large pool of children and adolescents who were referred for general clinical assessment following exposure to…

  13. [Lichen ruber only in skin areas exposed to light].

    PubMed

    Lamminger, C; Pagenstecher, A; Schröter, R

    1991-01-01

    In a patient with lichen ruber, skin lesions appeared exclusively on sun-exposed sections of the body. This localization is atypical in Europe. In tropical and subtropical countries lichen ruber actinicus can be observed in up to 30% of the population.

  14. 43. Interior view, east study window from the parlor. Exposed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    43. Interior view, east study window from the parlor. Exposed areas above and to the left of the window show remnants of decorative painting believed to date from early in the nineteenth century. - John Bartram House & Garden, House, 54th Street & Lindbergh Boulevard, Philadelphia, Philadelphia County, PA

  15. The ROSE experiments on the EXPOSE facility of the ISS

    NASA Astrophysics Data System (ADS)

    Panitz, C.; Rettberg, P.; Rabbow, E.; Horneck, G.

    2001-08-01

    EXPOSE is a multi-user facility to be mounted outside of the International Space Station (ISS). The tray-like structure will accomodate among others 6 biological PI-experiments or experiment systems of the ROSE (Responses of Organisms to the Space Environment) consortium. EXPOSE will support long-term in situ studies of microbes in artificial meteorites, as well as of microbial communities from special ecological niches, such as endolithic and evaporitic ecosystems. Each compartment is either vented, i.e. open to space vacuum, or sealed and then provided with a defined gas environment. The experiment pockets will be covered by an optical filter system to control intensity and spectral range of solar UV irradiation. To achieve maximum insolation, EXPOSE is mounted on a coarse pointing device. Control of sun exposure will be achieved by use of shutters. EXPOSE has been selected for the Early Utilisation Period of the ISS and will stay in space for 1.5 years. The results will contribute to our understanding of photobiological processes in simulated radiation climates of planets (e.g. early Earth, early and present Mars, and the role of the ozone layer in protecting the biosphere from harmful UV-B radiation), as well as studies of the probabilities and limitations for life to be distributed beyond its planet of origin.

  16. Obstetric Outcomes of Mothers Previously Exposed to Sexual Violence

    PubMed Central

    Gisladottir, Agnes; Luque-Fernandez, Miguel Angel; Harlow, Bernard L.; Gudmundsdottir, Berglind; Jonsdottir, Eyrun; Bjarnadottir, Ragnheidur I.; Hauksdottir, Arna; Aspelund, Thor; Cnattingius, Sven; Valdimarsdottir, Unnur A.

    2016-01-01

    Background There is a scarcity of data on the association of sexual violence and women's subsequent obstetric outcomes. Our aim was to investigate whether women exposed to sexual violence as teenagers (12–19 years of age) or adults present with different obstetric outcomes than women with no record of such violence. Methods We linked detailed prospectively collected information on women attending a Rape Trauma Service (RTS) to the Icelandic Medical Birth Registry (IBR). Women who attended the RTS in 1993–2010 and delivered (on average 5.8 years later) at least one singleton infant in Iceland through 2012 formed our exposed cohort (n = 1068). For each exposed woman's delivery, nine deliveries by women with no RTS attendance were randomly selected from the IBR (n = 9126) matched on age, parity, and year and season of delivery. Information on smoking and Body mass index (BMI) was available for a sub-sample (n = 792 exposed and n = 1416 non-exposed women). Poisson regression models were used to estimate Relative Risks (RR) with 95% confidence intervals (CI). Results Compared with non-exposed women, exposed women presented with increased risks of maternal distress during labor and delivery (RR 1.68, 95% CI 1.01–2.79), prolonged first stage of labor (RR 1.40, 95% CI 1.03–1.88), antepartum bleeding (RR 1.95, 95% CI 1.22–3.07) and emergency instrumental delivery (RR 1.16, 95% CI 1.00–1.34). Slightly higher risks were seen for women assaulted as teenagers. Overall, we did not observe differences between the groups regarding the risk of elective cesarean section (RR 0.86, 95% CI 0.61–1.21), except for a reduced risk among those assaulted as teenagers (RR 0.56, 95% CI 0.34–0.93). Adjusting for maternal smoking and BMI in a sub-sample did not substantially affect point estimates. Conclusion Our prospective data suggest that women with a history of sexual assault, particularly as teenagers, are at increased risks of some adverse obstetric outcomes. PMID:27007230

  17. Exposed Ice in the Northern Mid-Latitudes of Mars

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.

    2007-01-01

    Ice-Rich Layer: Polygonal features with dimensions of approximately 100 meters, bounded by cracks, are commonly observed on the martian northern plains. These features are generally attributed to thermal cracking of ice-rich sediments, in direct analogy to polygons in terrestrial polar regions. We mapped polygons in the northern mid-latitudes (30 to 65 N) using MOC and HiRISE images. Polygons are scattered across the northern plains, with a particular concentration in western Utopia Planitia. This region largely overlaps the Late Amazonian Astapus Colles unit, characterized by polygonal terrain and nested pits consistent with periglacial and thermokarst origins. Bright and Dark Polygonal Cracks: An examination of all MOC images (1997 through 2003) covering the study area demonstrated that, at latitudes of 55 to 65 N, most of the imaged polygons show bright bounding cracks. We interpret these bright cracks as exposed ice. Between 40 and 55 N, most of the imaged polygons show dark bounding cracks. These are interpreted as polygons from which the exposed ice has been removed by sublimation. The long-term stability limit for exposed ice, even in deep cracks, apparently lies near 55 N. Bright and Dark Spots: Many HiRISE and MOC frames showing polygons in the northern plains also show small numbers of bright and dark spots, particularly in western Utopia Planitia. Many of the spots are closely associated with collapse features suggestive of thermokarst. The spots range from tens to approximately 100 meters in diameter. The bright spots are interpreted as exposed ice, due to their prevalence on terrain mapped as ice rich. The dark spots are interpreted as former bright spots, which have darkened as the exposed ice is lost by sublimation. The bright spots may be the martian equivalents of pingos, ice-cored mounds found in periglacial regions on Earth. Terrestrial pingos from which the ice core has melted often collapse to form depressions similar to the martian dark spots

  18. Immunological studies in cattle exposed to polybrominated biphenyls

    PubMed Central

    Kateley, John R.; Bazzell, S. J.

    1978-01-01

    The intactness of the immune system in cattle exposed to polybrominated biphenyls (PBBs) has been investigated by using several immunoassays. Eighty-seven animals have been studied, 35 control animals (not exposed to PBBs) and 52 animals exposed to PBBs (0.02–30 ppm/g fat equivalent). The immunoassays included a complete blood count, identification of peripheral blood T and B lymphocyte subpopulations, serum immunoglobulin levels (IgG, IgM, and IgA), the in vitro response to lymphocytes to phytolectins (PHA, Con A, PWM), the antibody response to Keyhole limpet hemocyanin (KLH), the cell-mediated response to PPD, and determination of autoantibodies and/or immunosuppressive serum factors. For control and PBB-exposed cattle, there was no statistical difference between the number of circulating erythrocytes or leukocytes, the hematocrit, or hemoglobin content; the percentage or number of T and B lymphocytes; the isotope incorporation index (DNA synthesis) of lymphocytes in response to mitogens; the concentrations of serum immunoglobulins IgG, IgM, or IgA; the mean peak titer to KLH; or in vivo or in vitro immune response to PPD. Additional evaluation of cattle with tissue levels of PBB greater than 3 ppm/g tissue for hematological and immunological parameters revealed no statistical difference from control animals. Other experiments were performed to evaluate serum from cattle exposed to PBBs for autoantibodies to smooth muscle, mitochondrial or nuclear antigens. No evidence for autoantibodies was observed. Further studies were done to examine the cytotoxic and/or immunosuppressive activity of sera from PBB-exposed animals. In these studies, the blastogenic response of lymphocytes from control cattle and humans were evaluated in the presence and absence of serum from animals exposed to PBBs (> 3 ppm/g tissue). No evidence for either a cytotoxic or an immunosuppressive influence of such sera was demonstrable. Our studies indicate that PBB, at the levels studied, does

  19. Immunological studies in cattle exposed to polybrominated biphenyls.

    PubMed

    Kateley, J R; Bazzell, S J

    1978-04-01

    The intactness of the immune system in cattle exposed to polybrominated biphenyls (PBBs) has been investigated by using several immunoassays. Eighty-seven animals have been studied, 35 control animals (not exposed to PBBs) and 52 animals exposed to PBBs (0.02-30 ppm/g fat equivalent). The immunoassays included a complete blood count, identification of peripheral blood T and B lymphocyte subpopulations, serum immunoglobulin levels (IgG, IgM, and IgA), the in vitro response to lymphocytes to phytolectins (PHA, Con A, PWM), the antibody response to Keyhole limpet hemocyanin (KLH), the cell-mediated response to PPD, and determination of autoantibodies and/or immunosuppressive serum factors. For control and PBB-exposed cattle, there was no statistical difference between the number of circulating erythrocytes or leukocytes, the hematocrit, or hemoglobin content; the percentage or number of T and B lymphocytes; the isotope incorporation index (DNA synthesis) of lymphocytes in response to mitogens; the concentrations of serum immunoglobulins IgG, IgM, or IgA; the mean peak titer to KLH; or in vivo or in vitro immune response to PPD.Additional evaluation of cattle with tissue levels of PBB greater than 3 ppm/g tissue for hematological and immunological parameters revealed no statistical difference from control animals. Other experiments were performed to evaluate serum from cattle exposed to PBBs for autoantibodies to smooth muscle, mitochondrial or nuclear antigens. No evidence for autoantibodies was observed. Further studies were done to examine the cytotoxic and/or immunosuppressive activity of sera from PBB-exposed animals. In these studies, the blastogenic response of lymphocytes from control cattle and humans were evaluated in the presence and absence of serum from animals exposed to PBBs (> 3 ppm/g tissue). No evidence for either a cytotoxic or an immunosuppressive influence of such sera was demonstrable. Our studies indicate that PBB, at the levels studied, does not

  20. Epidemiological survey of workers exposed to inorganic germanium compounds

    PubMed Central

    Swennen, B; Mallants, A; Roels, H; Buchet, J; Bernard, A; Lauwerys, R; Lison, D

    2000-01-01

    OBJECTIVES—To assess occupational exposure to inorganic germanium (Ge) in workers from a producing plant, and to assess the health of these workers, with a special focus on respiratory, kidney, and liver functions.
METHODS—Cross sectional study of 75 workers exposed to Ge and 79 matched referents. Exposure was characterised by measuring air and urine concentrations of the element during a typical working week, and health was assessed by a questionnaire, clinical examination, lung function testing, chest radiography, and clinical chemistry in serum and urine, including high and low molecular weight urinary proteins.
RESULTS—Airborne concentrations of Ge (inhalable fraction) ranged from 0.03 to 300 µg/m, which was reflected by increased urinary excretion of Ge (0.12-200 µg/g creatinine, after the shift at the end of the working week). Lung, liver, and haematological variables were not significantly different between referents and workers exposed to Ge. A slightly higher urinary concentration of high molecular weight proteins (albumin and transferrin) was found in workers exposed to Ge, possibly reflecting subclinical glomerular changes. No relation was found between the intensity or duration of exposure and the urinary concentration of albumin. No difference between referents and workers exposed to Ge was found for other renal variables.
CONCLUSIONS—Measurement of urinary Ge can detect occupational exposure to inorganic Ge and its compounds. It is prudent to recommend the monitoring of renal variables in workers exposed to Ge.


Keywords: inorganic germanium; occupational exposure; biological monitoring PMID:10810110

  1. Newborn Hearing Screening in Neonates Exposed to Psychoactive Drugs

    PubMed Central

    Rocha, Bruna Salazar Castro da; Machado, Márcia Salgado; Zanini, Cláudia Fernandes Costa; Paniz, Tatiana de Carvalho; Menegotto, Isabela Hoffmeister

    2013-01-01

    Introduction In pregnancy, the mother and fetus share body structures based on the maternal organism. Exposure to psychoactive drugs in this period may have repercussions on the baby's hearing. Therefore, it is necessary to investigate this association. Aim Analyze the results of newborn hearing screening (NHS), the occurrence of associated risk factors, and the incidence of hearing loss in newborn exposed to psychoactive drugs during pregnancy. Methods This is an observational retrospective study done from a database analysis. From this database, records were selected about the use of psychoactive drugs by mothers during pregnancy, then the neonates were divide into two groups: the study group (146 babies exposed to drugs) and the control group (500 babies not exposed to drugs). The NHS failure rate, the presence of risk factors for hearing loss, and need for audiological diagnosis were analyzed in both groups. From these variables, absolute frequency and prevalence rates were calculated and the results compared between groups. Results There was no statistically significant difference in the comparison of NHS failure rates between the groups (p = 0.267). The occurrence of risk factors for hearing loss was greater in babies exposed to drugs (p < 0.0001). There was only one diagnosis of hearing loss, which occurred in the control group (p = 0.667). Conclusion The use of psychoactive drugs by mothers during pregnancy did not affect the NHS failure rate of this sample. However, the occurrence of significant risk factors in the study group showed a possible sensitivity of babies exposed to psychoactive drugs during pregnancy. PMID:25992062

  2. The AMINO experiment: a laboratory for astrochemistry and astrobiology on the EXPOSE-R facility of the International Space Station

    NASA Astrophysics Data System (ADS)

    Cottin, H.; Saiagh, K.; Guan, Y. Y.; Cloix, M.; Khalaf, D.; Macari, F.; Jérome, M.; Polienor, J.-M.; Bénilan, Y.; Coll, P.; Fray, N.; Gazeau, M.-C.; Raulin, F.; Stalport, F.; Carrasco, N.; Szopa, C.; Bertrand, M.; Chabin, A.; Westall, F.; Vergne, J.; Da Silva, L. A.; Maurel, M.-C.; Chaput, D.; Demets, R.

    2015-01-01

    The study of the evolution of organic matter subjected to space conditions, and more specifically to Solar photons in the vacuum ultraviolet range (120-200 nm) has been undertaken in low-Earth orbit since the 1990s, and implemented on various space platforms. This paper describes a photochemistry experiment called AMINO, conducted during 22 months between 2009 and 2011 on the EXPOSE-R ESA facility, outside the International Space Station. Samples with relevance to astrobiology (connected to comets, carbonaceous meteorites and micrometeorites, the atmosphere of Titan and RNA world hypothesis) have been selected and exposed to space environment. They have been analysed after return to the Earth. This paper is not discussing the results of the experiment, but rather gives a general overview of the project, the details of the hardware used, its configuration and recent developments to enable long-duration exposure of gaseous samples in tight closed cells enabling for the first time to derive quantitative results from gaseous phase samples exposed in space.

  3. Nutritional Status among the Children of Age Group 5-14 Years in Selected Arsenic Exposed and Non-Exposed Areas of Bangladesh

    PubMed Central

    Rezaul Karim, Mohammad; Ahmad, Sk. Akhtar

    2014-01-01

    Objective: To assess and compare the nutritional status of children aged 5-14 years in arsenic exposed and non- exposed areas. Materials and methods: It was a cross sectional study conducted on 600 children of age 5-14 years from arsenic exposed and non-exposed areas in Bangladesh. Designed questionnaire and check list were used for collection of data. To estimate BMI necessary anthropometric measurements of the studied children were done. Dietary intakes of the study children were assessed using 24-hours recall method. Results: The difference of socio-economic conditions between the children of exposed area and non-exposed area was not significant. On an average the body mass index was found to be significantly (p < 0.01) lower among the children of arsenic exposed area (49%) in comparison to that of children in non-exposed area (38%). Stunting (p < 0.01), wasting (p < 0.05) and underweight (p < 0.05) were significantly higher in exposed group in comparison to non-exposed group. No significant difference of nutrition intake was found between exposed and non-exposed children as well as thin and normal children. Conclusion: In this study children exposed to arsenic contaminated water were found to be suffered from lower nutritional status. PMID:25530768

  4. Ion Flux Environments for Exposed Spacecraft Surfaces in Interplanetary Space

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Altstatt, Richard; NeergaardParker, Linda; Skipworth, William

    2004-01-01

    Spacecraft surfaces in interplanetary space are exposed to solar wind ions. The bulk of the ions exhibit energies of a few kilovolts and are important only to surface interactions while a fraction of the solar wind extends to greater energies and may penetrate below the material surface. The importance of including solar wind ions in analysis of space environment effects on spacecraft is becoming more important as new spacecraft designs are considered which include systems such as sunshades, solar sail propulsion systems, and other mission critical features based on very thin materials. This paper provides a status report on development of solar wind ion environments to support engineering analysis of materials exposed to the space environment including techniques for reconstructing ion environments from solar wind plasma moments and energetic flux measurements and comparison of statistical flux environments to integrated mission fluence.

  5. Profiles of Reactivity in Cocaine-Exposed Children

    PubMed Central

    Schuetze, Pamela; Molnar, Danielle S.; Eiden, Rina D.

    2012-01-01

    This study explored the possibility that specific, theoretically consistent profiles of reactivity could be identified in a sample of cocaine-exposed infants and whether these profiles were associated with a range of infant and/or maternal characteristics. Cluster analysis was used to identify distinct groups of infants based on physiological, behavioral and maternal reported measures of reactivity. Five replicable clusters were identified which corresponded to 1) Dysregulated/High Maternal Report Reactors, 2) Low Behavioral Reactors, 3) High Reactors, 4) Optimal Reactors and 5) Dysregulated/Low Maternal Report Reactors. These clusters were associated with differences in prenatal cocaine exposure status, birthweight, maternal depressive symptoms, and maternal negative affect during mother-infant interactions. These results support the presence of distinct reactivity profiles among high risk infants recruited on the basis of prenatal cocaine exposure and demographically similar control group infants not exposed to cocaine. PMID:23204615

  6. Corrosion of beryllium exposed to celotex and water

    SciTech Connect

    Hill, M.A.; Butt, D.P.; Lillard, R.S.

    1997-12-01

    Celotex is a commercial rigid cellulose fiberboard product primarily used in the building construction industry. Currently celotex is being used as a packing material in AL-R8 containers. Ion chromatography of celotex packing material at Lawrence Livermore National Laboratory (LLNL) has indicated that this material contains aggressive anions, including chloride, which may accelerate corrosion. It is well known that beryllium is susceptible to pitting corrosion when exposed to chloride containing environments. Levy noted pitting in beryllium at the open circuit potential when exposed to 0.1 M NaCl solution. This investigation attempts to evaluate the potential risk of accelerated beryllium corrosion from celotex and water which may occur naturally when celotex dust comes into contact with moisture from the atmosphere.

  7. Laser-induced fluorescence of space-exposed polyurethane

    NASA Technical Reports Server (NTRS)

    Hill, Ralph H., Jr.

    1993-01-01

    The object of this work was to utilize laser-induced fluorescence technique to characterize several samples of space-exposed polyurethane. These samples were flown on the Long Duration Exposure Facility (LDEF), which was in a shuttle-like orbit for nearly 6 years. Because of our present work to develop laser-induced-fluorescence inspection techniques for polymers, space-exposed samples and controls were lent to us for evaluation. These samples had been attached to the outer surface of LDEF; therefore, they were subjected to thermal cycling, solar ultraviolet radiation, vacuum, and atomic oxygen. It is well documented that atomic oxygen and ultraviolet exposure have detrimental effects on many polymers. This was a unique opportunity to make measurements on material that had been naturally degraded by an unusual environment. During our past work, data have come from artificially degraded samples and generally have demonstrated a correlation between laser-induced fluorescence and tensile strength or elasticity.

  8. Papillomas on fish exposed to chlorinated wastewater effluent.

    PubMed

    Grizzle, J M; Melius, P; Strength, D R

    1984-11-01

    The presence of carcinogenic and mutagenic chemical(s) in the effluent of a wastewater treatment plant was indicated by papillomas developing on caged black bullheads (Ictalurus melas), hepatic enzyme induction in exposed fish, and Ames test mutagenicity of organic extracts of the wastewater. Although virus-like particles have been reported in papillomas of several other fish species, no evidence was obtained for the presence of viruses in the black bullhead papillomas. Mutagenic and carcinogenic chemicals were not identified in the wastewater, but chlorination was implicated as a factor contributing to the induction of the papillomas. The prevalence of papillomas on wild black bullheads exposed to the effluent decreased from 73 to 23% after the amount of residual chlorine (CAS: 7782-50-5) in the effluent leaving the chlorine contact chamber was reduced from 1.3-3.1 mg/liter to 0.25-1.2 mg/liter. PMID:6593489

  9. Physiological disturbances in Atlantic salmon exposed to crude oil

    SciTech Connect

    Gagnon, M.M.; Holdway, D.A.

    1995-12-31

    In Southern Australia, Atlantic salmon (Salmo salar) farming is undertaken in marine areas where extensive oil exploration, exploitation and transport are taking place. Pen-reared juvenile fish are at high risk of oil exposure through frequent small spills or major accidents. When exposed, commercial fisheries have to face million-dollar loses due to potential tainting of their stocks. In this study, juvenile Atlantic salmon were exposed to Bass Strait light crude oil in a fashion simulating an accidental oil spill at sea i.e. exposure to crude oil followed by a deputation period. Temporal trends in enzymatic bioindicators of exposure were investigated through exposure and deputation periods, as well as several biochemical and chemical measurements. The main objective of the study was to relate tainting with easily measured biological indicators of exposure to crude oil. Good correlations between bioindicators of exposure and tainting could assist fish farming industry to decide on the fate of fish stocks affected by oil taint.

  10. Mechanisms of gas precipitation in plasma-exposed tungsten

    SciTech Connect

    R. D. Kolasinski; D. F. Cowgill; D. C. Donovan; M. Shimada

    2012-05-01

    Precipitation in subsurface bubbles is a key process that governs how hydrogen isotopes migrate through and become trapped within plasma-exposed tungsten. We describe a continuum-scale model of hydrogen diffusion in plasma-exposed materials that includes the effects of precipitation. The model can account for bubble expansion via dislocation loop punching, using an accurate equation of state to determine the internal pressure. This information is used to predict amount of hydrogen trapped by bubbles, as well as the conditions where the bubbles become saturated. In an effort to validate the underlying assumptions, we compare our results with published positron annihilation and thermal desorption spectroscopy data, as well as our own measurements using the tritium plasma experiment (TPE).

  11. Temperature increase in the fetus exposed to UHF RFID readers.

    PubMed

    Fiocchi, Serena; Parazzini, Marta; Liorni, Ilaria; Samaras, Theodoros; Ravazzani, Paolo

    2014-07-01

    Exposure to electromagnetic fields (EMFs) has prominently increased during the last decades due to the rapid development of new technologies. Among the various devices emitting EMFs, those based on Radio-frequency identification (RFID) technologies are used in all aspects of everyday life, and expose people unselectively. This scenario could pose a potential risk for some groups of the general population, such as pregnant women, who are expected to be possibly more sensitive to the thermal effects produced by EMF exposure. This is the first paper that addresses the estimation of temperature rise in two pregnant women models exposed to ultrahigh frequency RFID by computational techniques. Results show that the maximum temperature increase of the fetus and of the pregnancy-related tissues is relatively high (even about 0.7 °C), not too far from the known threshold of biological effects. However, this increase is confined to a small volume in the tissues.

  12. Recovering badly exposed objects from digital photos using internet images

    NASA Astrophysics Data System (ADS)

    Savoy, Florian M.; Vonikakis, Vassilios; Winkler, Stefan; Süsstrunk, Sabine

    2014-03-01

    In this paper we consider the problem of clipped-pixel recovery over an entire badly exposed image region, using two correctly exposed images of the scene that may be captured under different conditions. The first reference image is used to recover texture; feature points are extracted along the boundaries of both the source and reference regions, while a warping function deforms the reference region to fit inside the source. The second reference is used to recover color by replacing the mean and variance of the texture reference image with those of the color reference. A user study conducted with both modified and original images demonstrates the benefits of our method. The results show that a majority of the enhanced images look natural and are preferred to the originals.

  13. Skin friction measurement with partially exposed polymer dispersed liquid crystals

    NASA Technical Reports Server (NTRS)

    Parmar, D. S.; Holmes, H. K.

    1993-01-01

    Partially exposed polymer dispersed liquid crystal thin film (10-25 microns) deposited on a flat glass substrate has been used for the first time to measure skin friction. Utilizing the shear-stress-induced director reorientation in the partially exposed liquid-crystal droplets, optical transmission under crossed polarization has been measured as a function of the air flow differential pressure. Direct measurement of the skin friction with a skin friction drag balance, under the same aerodynamic conditions, lets us correlate the skin friction with optical transmission. This provides a unique technique for the direct measurement of skin friction from the transmitted light intensity. The results are in excellent agreement with the model suggested in this paper.

  14. [Hematologic changes in workers exposed to radio wave radiation].

    PubMed

    Budinscak, V; Goldoni, J; Sarić, M

    1991-12-01

    Haematological parameters were measured in 43 radar operators employed in air traffic control occupationally exposed to microwave radiation of low intensity over a period of four years. Exposure to heat, soft X-ray radiation and noise were within maximally allowed limits. The haematological changes included a decreased number of erythrocytes, reticulocytes, platelets, segmented granulocytes and monocytes, and an increased number of leucocytes and lymphocytes. The changes were not pathologically significant and most of them were reversible.

  15. 16. INTERIOR OF ROOM 105 LOOKING TOWARD SOUTHEAST WALL. EXPOSED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. INTERIOR OF ROOM 105 LOOKING TOWARD SOUTHEAST WALL. EXPOSED POST EXISTS IN MIDDLE OF ROOM. A SMALL OPENING HAS BEEN CUT INTO THE UPPER PORTION OF THE SOUTHEAST WALL THROUGH TO THE ADJOINING ROOM (106). GYPSUM BOARD ON WALLS WITH WOOD TRIM, FLUORESCENT LIGHTING, AND VINYL COMPOSITION TILE ON FLOORS ARE ALL LATER ADDITIONS. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

  16. Toxicity of lunar dust assessed in inhalation-exposed rats

    PubMed Central

    Lam, Chiu-wing; Scully, Robert R.; Zhang, Ye; Renne, Roger A.; Hunter, Robert L.; McCluskey, Richard A.; Chen, Bean T.; Castranova, Vincent; Driscoll, Kevin E.; Gardner, Donald E.; McClellan, Roger O.; Cooper, Bonnie L.; McKay, David S.; Marshall, Linda; James, John T.

    2015-01-01

    Humans will again set foot on the moon. The moon is covered by a layer of fine dust, which can pose a respiratory hazard. We investigated the pulmonary toxicity of lunar dust in rats exposed to 0, 2.1, 6.8, 20.8 and 60.6 mg/m3 of respirable-size lunar dust for 4 weeks (6 h/day, 5 days/week); the aerosols in the nose-only exposure chambers were generated from a jet-mill ground preparation of a lunar soil collected during the Apollo 14 mission. After 4 weeks of exposure to air or lunar dust, groups of five rats were euthanized 1 day, 1 week, 4 weeks or 13 weeks after the last exposure for assessment of pulmonary toxicity. Biomarkers of toxicity assessed in bronchoalveolar fluids showed concentration-dependent changes; biomarkers that showed treatment effects were total cell and neutrophil counts, total protein concentrations and cellular enzymes (lactate dehydrogenase, glutamyl transferase and aspartate transaminase). No statistically significant differences in these biomarkers were detected between rats exposed to air and those exposed to the two low concentrations of lunar dust. Dose-dependent histopathology, including inflammation, septal thickening, fibrosis and granulomas, in the lung was observed at the two higher exposure concentrations. No lesions were detected in rats exposed to ≤6.8 mg/m3. This 4-week exposure study in rats showed that 6.8 mg/m3 was the highest no-observable-adverse-effect level (NOAEL). These results will be useful for assessing the health risk to humans of exposure to lunar dust, establishing human exposure limits and guiding the design of dust mitigation systems in lunar landers or habitats. PMID:24102467

  17. Toxicity of lunar dust assessed in inhalation-exposed rats.

    PubMed

    Lam, Chiu-wing; Scully, Robert R; Zhang, Ye; Renne, Roger A; Hunter, Robert L; McCluskey, Richard A; Chen, Bean T; Castranova, Vincent; Driscoll, Kevin E; Gardner, Donald E; McClellan, Roger O; Cooper, Bonnie L; McKay, David S; Marshall, Linda; James, John T

    2013-10-01

    Humans will again set foot on the moon. The moon is covered by a layer of fine dust, which can pose a respiratory hazard. We investigated the pulmonary toxicity of lunar dust in rats exposed to 0, 2.1, 6.8, 20.8 and 60.6 mg/m(3) of respirable-size lunar dust for 4 weeks (6 h/day, 5 days/week); the aerosols in the nose-only exposure chambers were generated from a jet-mill ground preparation of a lunar soil collected during the Apollo 14 mission. After 4 weeks of exposure to air or lunar dust, groups of five rats were euthanized 1 day, 1 week, 4 weeks or 13 weeks after the last exposure for assessment of pulmonary toxicity. Biomarkers of toxicity assessed in bronchoalveolar fluids showed concentration-dependent changes; biomarkers that showed treatment effects were total cell and neutrophil counts, total protein concentrations and cellular enzymes (lactate dehydrogenase, glutamyl transferase and aspartate transaminase). No statistically significant differences in these biomarkers were detected between rats exposed to air and those exposed to the two low concentrations of lunar dust. Dose-dependent histopathology, including inflammation, septal thickening, fibrosis and granulomas, in the lung was observed at the two higher exposure concentrations. No lesions were detected in rats exposed to ≤6.8 mg/m(3). This 4-week exposure study in rats showed that 6.8 mg/m(3) was the highest no-observable-adverse-effect level (NOAEL). These results will be useful for assessing the health risk to humans of exposure to lunar dust, establishing human exposure limits and guiding the design of dust mitigation systems in lunar landers or habitats. PMID:24102467

  18. Toxicity of lunar dust assessed in inhalation-exposed rats.

    PubMed

    Lam, Chiu-wing; Scully, Robert R; Zhang, Ye; Renne, Roger A; Hunter, Robert L; McCluskey, Richard A; Chen, Bean T; Castranova, Vincent; Driscoll, Kevin E; Gardner, Donald E; McClellan, Roger O; Cooper, Bonnie L; McKay, David S; Marshall, Linda; James, John T

    2013-10-01

    Humans will again set foot on the moon. The moon is covered by a layer of fine dust, which can pose a respiratory hazard. We investigated the pulmonary toxicity of lunar dust in rats exposed to 0, 2.1, 6.8, 20.8 and 60.6 mg/m(3) of respirable-size lunar dust for 4 weeks (6 h/day, 5 days/week); the aerosols in the nose-only exposure chambers were generated from a jet-mill ground preparation of a lunar soil collected during the Apollo 14 mission. After 4 weeks of exposure to air or lunar dust, groups of five rats were euthanized 1 day, 1 week, 4 weeks or 13 weeks after the last exposure for assessment of pulmonary toxicity. Biomarkers of toxicity assessed in bronchoalveolar fluids showed concentration-dependent changes; biomarkers that showed treatment effects were total cell and neutrophil counts, total protein concentrations and cellular enzymes (lactate dehydrogenase, glutamyl transferase and aspartate transaminase). No statistically significant differences in these biomarkers were detected between rats exposed to air and those exposed to the two low concentrations of lunar dust. Dose-dependent histopathology, including inflammation, septal thickening, fibrosis and granulomas, in the lung was observed at the two higher exposure concentrations. No lesions were detected in rats exposed to ≤6.8 mg/m(3). This 4-week exposure study in rats showed that 6.8 mg/m(3) was the highest no-observable-adverse-effect level (NOAEL). These results will be useful for assessing the health risk to humans of exposure to lunar dust, establishing human exposure limits and guiding the design of dust mitigation systems in lunar landers or habitats.

  19. Progressive systemic sclerosis occurring in patients exposed to chemicals.

    PubMed

    Czirják, L; Dankó, K; Schlammadinger, J; Surányi, P; Tamási, L; Szegedi, G Y

    1987-01-01

    Eight patients with systemic sclerosis previously exposed to organic chemical agents were investigated. Laboratory and clinical data of these patients were evaluated. The interval between the beginning of exposition and symptoms was 6.1 +/- 4.9 years. Considering the laboratory findings, a slight decrease in OKT4 positive T cell number was found. The antinucleolar and fine speckled antinuclear antibody pattern was found simultaneously in five cases. The possible role of chemical agents in the development of sclerodermic changes is discussed.

  20. Pseudohyphal variations of yeasts exposed to specific space flight parameters.

    PubMed

    Volz, P A; Hunter, R L

    1998-01-01

    Phenotypes of Saccharomyces cerevisiae and Rhodotorula rubra exposed to specific parameters of space flight, which were measured both quantitatively and qualitatively, produced variations in pseudohyphal formation. Both the length of the parent and branch psuedohyphal filaments varied according to specific wavelengths and energy levels of UV light exposures when phenotypic isolates were compared with the parent or ground control isolate of each yeast species. PMID:9881461

  1. Potential contribution of exposed resin to ecosystem emissions of monoterpenes

    NASA Astrophysics Data System (ADS)

    Eller, Allyson S. D.; Harley, Peter; Monson, Russell K.

    2013-10-01

    Conifers, especially pines, produce and store under pressure monoterpene-laden resin in canals located throughout the plant. When the plants are damaged and resin canals punctured, the resin is exuded and the monoterpenes are released into the atmosphere, a process that has been shown to influence ecosystem-level monoterpene emissions. Less attention has been paid to the small amounts of resin that are exuded from branches, expanding needles, developing pollen cones, and terminal buds in the absence of any damage. The goal of this study was to provide the first estimate of the potential of this naturally-exposed resin to influence emissions of monoterpenes from ponderosa pine (Pinus ponderosa) ecosystems. When resin is first exuded as small spherical beads from undamaged tissues it emits monoterpenes to the atmosphere at a rate that is four orders of magnitude greater than needle tissue with an equivalent exposed surface area and the emissions from exuded beads decline exponentially as the resin dries. We made measurements of resin beads on the branches of ponderosa pine trees in the middle of the growing season and found, on average, 0.15 cm2 of exposed resin bead surface area and 1250 cm2 of total needle surface area per branch tip. If the resin emerged over the course of 10 days, resin emissions would make up 10% of the ecosystem emissions each day. Since we only accounted for exposed resin at a single point in time, this is probably an underestimate of how much total resin is exuded from undamaged pine tissues over the course of a growing season. Our observations, however, reveal the importance of this previously unrecognized source of monoterpenes emitted from pine forests and its potential to influence regional atmospheric chemistry dynamics.

  2. Cardiac arrhythmia in refrigerator repairmen exposed to fluorocarbons.

    PubMed

    Edling, C; Ohlson, C G; Ljungkvist, G; Oliv, A; Söderholm, B

    1990-03-01

    A field study of 89 refrigerator repairmen was carried out to ascertain whether occupational exposure to fluorocarbons induces cardiac arrhythmia. The concentrations of fluorocarbons in the breathing zones and the heart activity were recorded simultaneously. Most cooling systems contained FC 12 or FC 22. The highest level recorded in one minute was 14,000 ppm and the highest time weighted level during eight hours was 280 ppm. Two types of arrhythmia were recorded, ectopic beats and sudden bradycardia. A within subject comparison design was applied and the main parameter was the difference in arrhythmia frequencies between exposed and unexposed periods. No appreciable differences between exposed and unexposed periods and no consistent dose effect relations were observed, although subjects in the medium exposure category showed a difference of borderline significance (Wilcoxon's test: p = 0.05, one tailed). The frequencies of arrhythmia when unexposed were somewhat higher than previously reported. Misclassification of the exposure and the possible confounding effect of physical workload and psychological strain may have obscured a causal relation and therefore a minor effect cannot be ruled out. The results do not support the notion that fluorocarbons induce cardiac arrhythmia in occupationally exposed refrigerator repairmen.

  3. Cardiac arrhythmia in refrigerator repairmen exposed to fluorocarbons.

    PubMed Central

    Edling, C; Ohlson, C G; Ljungkvist, G; Oliv, A; Söderholm, B

    1990-01-01

    A field study of 89 refrigerator repairmen was carried out to ascertain whether occupational exposure to fluorocarbons induces cardiac arrhythmia. The concentrations of fluorocarbons in the breathing zones and the heart activity were recorded simultaneously. Most cooling systems contained FC 12 or FC 22. The highest level recorded in one minute was 14,000 ppm and the highest time weighted level during eight hours was 280 ppm. Two types of arrhythmia were recorded, ectopic beats and sudden bradycardia. A within subject comparison design was applied and the main parameter was the difference in arrhythmia frequencies between exposed and unexposed periods. No appreciable differences between exposed and unexposed periods and no consistent dose effect relations were observed, although subjects in the medium exposure category showed a difference of borderline significance (Wilcoxon's test: p = 0.05, one tailed). The frequencies of arrhythmia when unexposed were somewhat higher than previously reported. Misclassification of the exposure and the possible confounding effect of physical workload and psychological strain may have obscured a causal relation and therefore a minor effect cannot be ruled out. The results do not support the notion that fluorocarbons induce cardiac arrhythmia in occupationally exposed refrigerator repairmen. PMID:2328227

  4. Increased gluconeogenesis in rats exposed to hyper-G stress

    NASA Technical Reports Server (NTRS)

    Daligcon, B. C.; Oyama, J.; Hannak, K.

    1985-01-01

    The effect of glucogenesis on the plasma glucose and liver glycogen of rats exposed to hyper-G stress is investigated. Twelve male Sprague-Dawley rats are injected with C-14 lactate, alanine, of glycerol, and six of the rats are exposed to 3.1 G for 0.25, 0.50, and 1.0 hr. The plasma glucose and liver glycogen of the centrifuged and noncentrifuged rats are analyzed. A significant increase in the C-14 incorporation of the substrate into the plasma glucose and liver glycogen is observed in the centrifuged rats. The injection of 5-methoxyindole-2-carboxylic acid, a gluconeogenesis inhibitor, results in a blocked increase in plasma glucose and liver glycogen. The role of epinephrine on the hyperglycemic and liver glycogen responses of centrifuged rats is studied. It is concluded that the initial increase in plasma glucose and liver glycogen in rats exposed to hyper-G stress is the result of an increased rate of gluconeogenesis.

  5. Unleashing Cancer Cells on Surfaces Exposing Motogenic IGDQ Peptides.

    PubMed

    Corvaglia, Valentina; Marega, Riccardo; De Leo, Federica; Michiels, Carine; Bonifazi, Davide

    2016-01-20

    Thiolated peptides bearing the Ile-Gly-Asp (IGD) motif, a highly conserved sequence of fibronectin, are used for the preparation of anisotropic self-assembled monolayers (SAM gradients) to study the whole-population migratory behavior of metastatic breast cancer cells (MDA-MB-231 cells). Ile-Gly-Asp-Gln-(IGDQ)-exposing SAMs sustain the adhesion of MDA-MB-231 cells by triggering focal adhesion kinase phosphorylation, similarly to the analogous Gly-Arg-Gly-Asp-(GRGD)-terminating surfaces. However, the biological responses of different cell lines interfaced with the SAM gradients show that only those exposing the IGDQ sequence induce significant migration of MDA-MB-231 cells. In particular, the observed migratory behavior suggests the presence of cell subpopulations associated with a "stationary" or a "migratory" phenotype, the latter determining a considerable cell migration at the sub-cm length scale. These findings are of great importance as they suggest for the first time an active role of biological surfaces exposing the IGD motif in the multicomponent orchestration of cellular signaling involved in the metastatic progression.

  6. Ethanol emission from loose corn silage and exposed silage particles

    NASA Astrophysics Data System (ADS)

    Hafner, Sasha D.; Montes, Felipe; Rotz, C. Alan; Mitloehner, Frank

    2010-11-01

    Silage on dairy farms has been identified as a major source of volatile organic compound (VOC) emissions. However, rates of VOC emission from silage are not accurately known. In this work, we measured ethanol (a dominant silage VOC) emission from loose corn silage and exposed corn silage particles using wind tunnel systems. Flux of ethanol was highest immediately after exposing loose silage samples to moving air (as high as 220 g m -2 h -1) and declined by as much as 76-fold over 12 h as ethanol was depleted from samples. Emission rate and cumulative 12 h emission increased with temperature, silage permeability, exposed surface area, and air velocity over silage samples. These responses suggest that VOC emission from silage on farms is sensitive to climate and management practices. Ethanol emission rates from loose silage were generally higher than previous estimates of total VOC emission rates from silage and mixed feed. For 15 cm deep loose samples, mean cumulative emission was as high as 170 g m -2 (80% of initial ethanol mass) after 12 h of exposure to an air velocity of 5 m s -1. Emission rates measured with an emission isolation flux chamber were lower than rates measured in a wind tunnel and in an open setting. Results show that the US EPA emission isolation flux chamber method is not appropriate for estimating VOC emission rates from silage in the field.

  7. Antioxidant status of neonates exposed in utero to tobacco smoke.

    PubMed

    Fayol, L; Gulian, J M; Dalmasso, C; Calaf, R; Simeoni, U; Millet, V

    2005-01-01

    To investigate the influence of maternal smoke exposure on neonatal and maternal antioxidant status, 39 mothers who were active smokers, 14 mothers exposed to environmental tobacco smoke (ETS), 17 controls, and their newborns were included in a prospective, controlled study. Plasma total antioxidant capacity, measured as total radical-trapping antioxidant parameter (TRAP) and ferric reducing antioxidant power (FRAP), and concentrations of specific antioxidants were measured in cord and in maternal blood. A similar, significant increase in ceruloplasmin concentration was observed in neonates born to actively smoking mothers and in those born to ETS exposed mothers. Uric acid and TRAP concentrations were significantly increased in ETS-exposed newborns and their mothers, compared to newborns and mothers from the active smoking and no-exposure groups with a trend towards increased uric acid, TRAP and FRAP concentrations being observed in the active smokers group. Neonatal and maternal antioxidant concentrations correlated significantly, except for ceruloplasmin. Cord blood vitamin A, E and C concentrations were unaffected by smoke exposure. These results show that maternal active smoking as well as ETS exposure significantly affect neonatal and maternal antioxidant status. PMID:15539769

  8. Altered amygdala connectivity in urban youth exposed to trauma.

    PubMed

    Thomason, Moriah E; Marusak, Hilary A; Tocco, Maria A; Vila, Angela M; McGarragle, Olivia; Rosenberg, David R

    2015-11-01

    Early life trauma exposure represents a potent risk factor for the development of mental illnesses such as anxiety, depression and post-traumatic stress disorder. Moreover, deleterious consequences of trauma are exacerbated in youth living in impoverished, urban environments. A priori probability maps were used to examine resting-state functional connectivity (FC) of the amygdala in 21 trauma-exposed, and 21 age- and sex-matched urban children and adolescents (youth) without histories of trauma. Intrinsic FC analyses focused on amygdala-medial prefrontal circuitry, a key emotion regulatory pathway in the brain. We discovered reduced negative amygdala-subgenual cingulate connectivity in trauma-exposed youth. Differences between groups were also identified in anterior insula and dorsal anterior cingulate to amygdala connectivity. Overall, results suggest a model in which urban-dwelling trauma-exposed youth lack negative prefrontal to amygdala connectivity that may be critical for regulation of emotional responses. Functional changes in amygdala circuitry might reflect the biological embedding of stress reactivity in early life and mediate enhanced vulnerability to stress-related psychopathology. PMID:25836993

  9. Chromosomal aberrations analysis in a Brazilian population exposed to pesticides.

    PubMed

    Antonucci, G A; de Syllos Cólus, I M

    2000-01-01

    In spite of being harmful, pesticides are widely used in Brazil. Their genotoxic effects might be studied through population monitoring by means of the analysis of chromosomal aberrations in occupationally exposed individuals. The aim of this study was to evaluate the chromosomal aberration frequencies in temporary cultures of lymphocytes from periferic blood of 23 workers professionally exposed to a mixture of pesticides. The workers were employed by the Agronomic Institute of Parana (Brazil) and used all of the prevention measures provided. A detailed history of pesticide use, as well as personal data, smoking habits, and history of recent illnesses and medical treatment were collected through a standardized questionnaire administered to each subject. Nonexposed subjects, matched for age, sex, and smoking habits, served as the negative control. A total of 100 cells were analyzed from each individual. A significant increase in chromosomal aberration frequencies was observed in exposed individuals when compared to the control group. Some individual characteristics such as age, sex, time of exposure to the pesticides, and smoking habits showed no correlation with chromosomal aberrations. Therefore, the positive results may be considered true effects of pesticides on human somatic cells. PMID:10992273

  10. Expose : procedure and results of the joint experiment verification tests

    NASA Astrophysics Data System (ADS)

    Panitz, C.; Rettberg, P.; Horneck, G.; Rabbow, E.; Baglioni, P.

    The International Space Station will carry the EXPOSE facility accommodated at the universal workplace URM-D located outside the Russian Service Module. The launch will be affected in 2005 and it is planned to stay in space for 1.5 years. The tray like structure will accomodate 2 chemical and 6 biological PI-experiments or experiment systems of the ROSE (Response of Organisms to Space Environment) consortium. EXPOSE will support long-term in situ studies of microbes in artificial meteorites, as well as of microbial communities from special ecological niches, such as endolithic and evaporitic ecosystems. The either vented or sealed experiment pockets will be covered by an optical filter system to control intensity and spectral range of solar UV irradiation. Control of sun exposure will be achieved by the use of individual shutters. To test the compatibility of the different biological systems and their adaptation to the opportunities and constraints of space conditions a profound ground support program has been developed. The procedure and first results of this joint Experiment Verification Tests (EVT) will be presented. The results will be essential for the success of the EXPOSE mission and have been done in parallel with the development and construction of the final hardware design of the facility. The results of the mission will contribute to the understanding of the organic chemistry processes in space, the biological adaptation strategies to extreme conditions, e.g. on early Earth and Mars, and the distribution of life beyond its planet of origin.

  11. Expose-R experiment on effects of open space condition on survivorship in dormant stages of aquatic invertebrates

    NASA Astrophysics Data System (ADS)

    Alekseev, Victor; Novikova, Nataliya; Levinskikh, Margarita; Sychev, Vladimir; Yusoff, Fatimah; Azuraidi, Osman

    2012-07-01

    Dormancy protects animals and plants in harsh environmental conditions from months up to hundred years. This phenomenon is perspective for space researches especially for interplanetary missions. Direct experiments in open space BYORYSK supported in principle the fact of survivorship of bacteria, fungi spores, seed of plants and crustacean dormant cysts. Even though the rate of survivorship in long-term treatments was low but good enough to conclude that biological invasion even to Mars is a real danger. As soon as the BYORYSK lunch was made of metal the possibility for resting stages to survive under UV treatment in vacuum without some protection was not clear. To test it an ESA and RSA equipment titled EXPOSE-R was applied. The EXPOSE-R facility was an external facility attached to the outside of the Zvezda Service Module in ISS in the end of November 2008. It had glace windows transparent for UV-radiation and possibility to measure temperature, space- and UV-radiation. Among a number of experiments requiring exposure to the open space environment it had a biological launch containing resting stages of terrestrial and aquatic organisms. These stages included dried ephippia of cladoceran Daphnia magna differentiated on size, dormant eggs of ostracode Eucypris ornate, cysts of fair-shrimp Streptocephalus torvicornis ( all from hemi desert Caspian area) and Artemis salina from salt lake Crimean populations. All dormant stages were kept in transparent to UV plastic bags placed in three layers. After about two years of exposing in open space dormant stages of 3 species A. salina, D. magna, S. torvicornis successfully survived at different scales but in second and third layers only . The highest level of survivorship was found in A. salina cysts. In preliminary land experiments that imitated land EXPOSE imitation of outside space station UV and vacuum conditions survivorship in resting eggs of D .magna, S. torvicornis and E. ornate was tested also. The total UV dose of

  12. Neurologic function among termiticide applicators exposed to chlorpyrifos.

    PubMed Central

    Steenland, K; Dick, R B; Howell, R J; Chrislip, D W; Hines, C J; Reid, T M; Lehman, E; Laber, P; Krieg, E F; Knott, C

    2000-01-01

    Chlorpyrifos is a moderately toxic organophosphate pesticide. Houses and lawns in the United States receive a total of approximately 20 million annual chlorpyrifos treatments, and 82% of U.S. adults have detectable levels of a chlorpyrifos metabolite (3,5, 6-trichloro-2-pyridinol; TCP) in the urine. The U.S. Environmental Protection Agency has estimated that there are 5,000 yearly reported cases of accidental chlorpyrifos poisoning, and approximately one-fourth of these cases exhibit symptoms. Organophosphates affect the nervous system, but there are few epidemiologic data on chlorpyrifos neurotoxicity. We studied neurologic function in 191 current and former termiticide applicators who had an average of 2.4 years applying chlorpyrifos and 2.5 years applying other pesticides, and we compared them to 189 nonexposed controls. The average urinary TCP level for 65 recently exposed applicators was 629.5 microg/L, as compared to 4.5 microg/L for the general U.S. population. The exposed group did not differ significantly from the nonexposed group for any test in the clinical examination. Few significant differences were found in nerve conduction velocity, arm/hand tremor, vibrotactile sensitivity, vision, smell, visual/motor skills, or neurobehavioral skills. The exposed group did not perform as well as the nonexposed group in pegboard turning tests and some postural sway tests. The exposed subjects also reported significantly more symptoms, including memory problems, emotional states, fatigue, and loss of muscle strength; our more quantitative tests may not have been adequate to detect these symptoms. Eight men who reported past chlorpyrifos poisoning had a pattern of low performance on a number of tests, which is consistent with prior reports of chronic effects of organophosphate poisoning. Overall, the lack of exposure effects on the clinical examination was reassuring. The findings for self-reported symptoms raise some concern, as does the finding of low performance

  13. Exposed Ice in the Northern Mid-Latitudes of Mars

    NASA Astrophysics Data System (ADS)

    Allen, C. C.

    2007-12-01

    Ice-Rich Layer: Polygonal features with dimensions of approximately 100 meters, bounded by cracks, are commonly observed on the martian northern plains. These features are generally attributed to thermal cracking of ice-rich sediments, in direct analogy to polygons in terrestrial polar regions [1,2]. We mapped polygons in the northern mid-latitudes (30 to 65 N) using MOC and HiRISE images [3]. Polygons are scattered across the northern plains, with a particular concentration in western Utopia Planitia. This region largely overlaps the Late Amazonian Astapus Colles unit, characterized by polygonal terrain and nested pits consistent with periglacial and thermokarst origins [4]. Bright and Dark Polygonal Cracks: An examination of all MOC images (1997 through 2003) covering the study area demonstrated that, at latitudes of 55 to 65 N, most of the imaged polygons show bright bounding cracks. We interpret these bright cracks as exposed ice. Between 40 and 55 N, most of the imaged polygons show dark bounding cracks [5]. These are interpreted as polygons from which the exposed ice has been removed by sublimation. The long-term stability limit for exposed ice, even in deep cracks, apparently lies near 55 N. Bright and Dark Spots: Many HiRISE and MOC frames showing polygons in the northern plains also show small numbers of bright and dark spots, particularly in western Utopia Planitia. Many of the spots are closely associated with collapse features suggestive of thermokarst. The spots range from tens to approximately 100 meters in diameter. The bright spots are interpreted as exposed ice, due to their prevalence on terrain mapped as ice rich. The dark spots are interpreted as former bright spots, which have darkened as the exposed ice is lost by sublimation. The bright spots may be the martian equivalents of pingos, ice-cored mounds found in periglacial regions on Earth [6,7,8,9, 10]. Terrestrial pingos from which the ice core has melted often collapse to form depressions

  14. BOSS on EXPOSE-R2-Comparative Investigations on Biofilm and Planktonic cells of Deinococcus geothermalis as Mission Preparation Tests

    NASA Astrophysics Data System (ADS)

    Panitz, C.; Rettberg, P.; Frösler, J.; Flemming, H.-C.; Rabbow, E.; Reitz, G.

    2013-09-01

    Biofilms are of interest for Astrobiological investigations since they are one of the oldest clear signs of life on Earth. In the experiment BOSS the hypothesis will be tested if the biofilm form of life with microorganisms embedded and aggregated in their EPS matrix is suited to support long-term survival of microorganisms under the harsh environmental conditions as they exist in space and on Mars and is superior to the same bacteria in the form of planktonic cultures. An additional protective role may be provided by particles associated in biofilms which may shield the organisms against radiation. The experiment will be flown on EXPOSE-R2 attached outside of the ISS on the Russian module. BOSS has participated the Experiment verification tests and will attend the upcoming Science verification test carried out in the Planetary and Space Simulation Facilities at DLR. The launch is scheduled for April 2014.

  15. Chronic Alterations in Serotonin Function: Dynamic Neurochemical Properties in Agonistic Behavior of the Crayfish, Orconectes rusticus

    PubMed Central

    Panksepp, Jules B.; Huber, Robert

    2016-01-01

    The biogenic amine serotonin [5-hydroxytryptamine (5-HT)] has received considerable attention for its role in behavioral phenomena throughout a broad range of invertebrate and vertebrate taxa. Acute 5-HT infusion decreases the likelihood of crayfish to retreat from dominant opponents. The present study reports the biochemical and behavioral effects resulting from chronic treatment with 5-HT-modifying compounds delivered for up to 5 weeks via silastic tube implants. High performance liquid chromatography with electrochemical detection (HPLC-ED) confirmed that 5,7-dihydroxytryptamine (5,7-DHT) effectively reduced 5-HT in all central nervous system (CNS) areas, except brain, while a concurrent accumulation of the compound was observed in all tissues analyzed. Unexpectedly, two different rates of chronic 5-HT treatment did not increase levels of the amine in the CNS. Behaviorally, 5,7-DHT treated crayfish exhibited no significant differences in measures of aggression. Although treatment with 5-HT did not elevate 5-HT content in the CNS, infusion at a slow rate caused animals to escalate more quickly while 5-HT treatment at a faster rate resulted in slower escalation. 5,7-DHT is commonly used in behavioral pharmacology and the present findings suggest its biochemical properties should be more thoroughly examined. Moreover, the apparent presence of powerful compensatory mechanisms indicates our need to adopt an increasingly dynamic view of the serotonergic bases of behavior like crayfish aggression. PMID:11891663

  16. Petroleum films exposed to sunlight produce hydroxyl radical.

    PubMed

    Ray, Phoebe Z; Tarr, Matthew A

    2014-05-01

    Sunlight exposed oil films on seawater or pure water produced substantial amounts of hydroxyl radical as a result of irradiation. Oil was collected from the surface of the Gulf of Mexico following the Deepwater Horizon spill and exposed to simulated sunlight in thin films over water. Photochemical production of hydroxyl radical was measured with benzoic acid as a selective chemical probe in the aqueous layer. Total hydroxyl radical formation was studied using high benzoic acid concentrations and varying exposure time. The total amount of hydroxyl radical produced in 24 h irradiations of thin oil films over Gulf of Mexico water and pure water were 3.7×10(-7) and 4.2×10(-7) moles respectively. Steady state concentrations of hydroxyl radical were measured using a competition kinetics approach. Hydroxyl radical concentrations of 1.2×10(-16) to 2.4×10(-16) M were observed for seawater and pure water under oil films. Titanium dioxide (TiO2) nanomaterials were added to the system in an effort to determine if the photocatalyst would enhance oil photodegradation. The addition of TiO2 nanoparticles dramatically changed the observed formation rate of hydroxyl radical in the systems with NP water at pH 3, showing increased formation rate in many cases. With photocatalyst, the steady state concentration of radical decreased, predominantly due to an increase in the hydroxyl radical scavenging rate with oxide present. This study illustrates that oil is a strong and important source of hydroxyl radical when exposed to sunlight. The fate of oil and other dissolved species following oil spills will be heavily dependent on the formation and fate of hydroxyl radical.

  17. Neurobehavioural evaluation of Venezuelan workers exposed to inorganic lead.

    PubMed Central

    Maizlish, N A; Parra, G; Feo, O

    1995-01-01

    OBJECTIVES--To assess neurobehavioural effects of low exposure to lead, 43 workers from a lead smelter and 45 workers from a glass factory were evaluated with the World Health Organisation neurobehavioural core test battery (NCTB) in a cross sectional study. METHODS--The NCTB comprises a questionnaire and seven tests that measure simple reaction time, short-term memory (digit span, Benton), mood (profile of mood states), eye-hand coordination (Santa Ana pegboard, pursuit aiming II), and perceptual speed (digit-symbol). RESULTS--Smelter workers were employed on average for four years, and had a mean blood lead concentration of 2.0 mumol/l (42 micrograms/dl). Glass factory workers had a mean of 0.72 mumol/l (15 micrograms/dl). Historical blood lead concentrations were used to classify exposure based on current, peak, and time weighted average. Although the exposed workers performed less well than the non-exposed in 10 of 14 response variables, only profile of mood states tension-anxiety, hostility, and depression mood scales showed a significantly poorer dose-response relation with blood lead concentration in multiple linear regression models that included age, education, and alcohol intake as covariates. The frequency of symptoms of anger, depression, fatigue, and joint pain were also significantly increased in the exposed group. CONCLUSION--This study is consistent with the larger body of neurobehavioural research of low occupational exposure to lead. The small effects found in this study occurred at blood lead concentrations slightly lower than those reported in several previous studies. PMID:7627319

  18. Tuberculosis among workers exposed to free silica dust.

    PubMed

    Tiwari, Rajnarayan R; Sharma, Yashwant K; Saiyed, Habibullah N

    2007-05-01

    Tuberculosis (TB) is a global emergency. Poverty, increasing migration, homelessness and the compulsions to live and work in high-risk environments are making people increasingly susceptible to the disease. Those working in mines, construction work, stone-crushing and in other similar occupations where there is a greater level of exposure to silica dust are specially vulnerable. Though the association between TB and silicosis has been firmly established by the results of epidemiologic studies no attempts have been made to study the epidemiological features of radiologically active TB among free silica exposed workers. Thus the cross sectional study was carried out among slate pencil workers and quartz stone crushers to assess the prevalence of TB and some associated epidemiological factors. It included 253 quartz workers and 102 slate pencil workers. Clinical history and chest radiographs were used for labeling the subjects as tuberculotic. The pulmonary functions of the subjects were measured using Spirovit SP- 10. Statistical analysis was carried out using statistical software package Epi Info 3.3.2. Among stone crushers the prevalence of TB was found to be 10.7% while among slate pencil workers it was as high as 22.5%. Among the quartz stone-crushers the workers aged ≥35 years, those exposed for ≥3 years and those who were smokers had higher risk TB while among the slate pencil workers, only those exposed for ≥10 years had higher risk. Though the FVC and FEV(1) values of the workers having TB were lower than those having normal radiographs, the differences were found to statistically non-significant.

  19. Study of electronic transport in gamma ray exposed nanowires

    SciTech Connect

    Gehlawat, Devender Chauhan, R.P.

    2014-01-01

    Graphical abstract: A sharp decline in the I–V characteristics of Cu (and Cd) nanowires was experimentally observed after the gamma ray exposure of nanowires. Irradiation induced transformations in the granular properties and the resonance state of electron–phonon coupling beyond a particular value of external field may be accountable for observed shape of I–V characteristics in gamma ray exposed nanowires. - Highlights: • Cu and Cd nanowires were synthesized by technique of electrodeposition in templates. • The nanowires were exposed to different doses of gamma ray photons. • A sharp decline in the current in I–V characteristics (IVC) was observed. • Structural deviation in terms of granular orientations was also analysed. • The electron–phonon coupling may be responsible for observed sharp decline in IVC. - Abstract: One dimensional nanostructures provide the most restricted and narrow channel for the transport of charge carriers and therefore 1D structures preserve their significance from the viewpoint of electronic devices. The net radiation effect on nanomaterials is expected to be more (due to their increased reactivity and lesser bulk volume) than their bulk counterparts. Radiation often modifies the structure and simultaneously the other physical properties of materials. In this manner, the irradiation phenomenon could be counted as a strong criterion to induce changes in the structural and electrical properties of nanowires. We have studied the effect of gamma rays on the electronic flow through Cu and Cd nanowires by plotting their I–V characteristics (IVC). The IVC of gamma ray exposed nanowires was found to be a combination of the linear and nonlinear regions and a decreasing pattern in the electrical conductivity (calculated from the linear portion of IVC) was observed as we increased the dose of gamma rays.

  20. Thermoregulation in laboratory mammals and humans exposed to anticholinesterase agents.

    PubMed

    Gordon, C J

    1994-01-01

    The regulation of body temperature is one of many homeostatic functions affected by exposure to anticholinesterase (antiChE) pesticides, and related compounds. In the study of antiChE neurotoxicity, thermoregulatory variables are often used as sensitive physiological indices. Hence, a review on the thermoregulatory aspects of antiChE agents would be useful to researchers in a variety of fields. A reduction in body temperature is a commonly used indicator of antiChE poisoning in laboratory rodents. On the other hand, humans and some other species often shown an elevation in body temperature when exposed to antiChE agents. Hyperthermia has also been noted in animals treated with either low levels of antiChEs or during recovery from high doses of antiChEs. In this review, the literature dealing with the central and peripheral effects of cholinergic agonists and antagonists is reassessed because the thermoregulatory effects of antiChEs are thought to be linked to the activation of cholinergic pathways. This is followed by a thorough review of the studies reporting thermoregulatory responses in laboratory rodents and humans exposed to low and high doses of a variety of antiChE agents, including the organophosphate- (OP) and carbamate- (CB) based pesticides and related drugs. Attention is given to the possible mechanism of action of OPs on thermoregulation in the laboratory rodent including the involvement of behavioral and autonomic processes. The incidence of antiChE-induced hyperthermia (fever) in humans exposed to antiChEs is also addressed. Other topics of antiChE-induced thermoregulatory dysfunction discussed in this review include the role of exercise, heat, and cold stress, tolerance to antiChE agents, and genetic variability. Overall, the mechanism of antiChE-induced changes in body temperature cannot always be explained solely by the immediate consequences of ChE inhibition. PMID:7845326

  1. Petroleum films exposed to sunlight produce hydroxyl radical.

    PubMed

    Ray, Phoebe Z; Tarr, Matthew A

    2014-05-01

    Sunlight exposed oil films on seawater or pure water produced substantial amounts of hydroxyl radical as a result of irradiation. Oil was collected from the surface of the Gulf of Mexico following the Deepwater Horizon spill and exposed to simulated sunlight in thin films over water. Photochemical production of hydroxyl radical was measured with benzoic acid as a selective chemical probe in the aqueous layer. Total hydroxyl radical formation was studied using high benzoic acid concentrations and varying exposure time. The total amount of hydroxyl radical produced in 24 h irradiations of thin oil films over Gulf of Mexico water and pure water were 3.7×10(-7) and 4.2×10(-7) moles respectively. Steady state concentrations of hydroxyl radical were measured using a competition kinetics approach. Hydroxyl radical concentrations of 1.2×10(-16) to 2.4×10(-16) M were observed for seawater and pure water under oil films. Titanium dioxide (TiO2) nanomaterials were added to the system in an effort to determine if the photocatalyst would enhance oil photodegradation. The addition of TiO2 nanoparticles dramatically changed the observed formation rate of hydroxyl radical in the systems with NP water at pH 3, showing increased formation rate in many cases. With photocatalyst, the steady state concentration of radical decreased, predominantly due to an increase in the hydroxyl radical scavenging rate with oxide present. This study illustrates that oil is a strong and important source of hydroxyl radical when exposed to sunlight. The fate of oil and other dissolved species following oil spills will be heavily dependent on the formation and fate of hydroxyl radical. PMID:24405967

  2. Cultural Heritage exposed to landslide and flood risk in Italy

    NASA Astrophysics Data System (ADS)

    Spizzichino, Daniele; Cacace, Carlo; Iadanza, Carla; Trigila, Alessandro

    2013-04-01

    Italy is the country that owns most of the world cultural heritage as it's clear from the list of sites of inestimable value to humanity, prepared by UNESCO under the Convention concerning the protection of the world cultural and natural heritage ratified in 1972. The Italian territory is also particularly prone to natural hazards such as landslides, floods, earthquakes, volcanic eruptions, subsidence and coastal erosion which undermine the protection and preservation of cultural heritage. Aim of the present work is to provide an estimate of architectural, monumental and archaeological heritage exposed to landslide and flood risk at national scale. The input data are: the Italian Cultural Heritage database (Carta del Rischio del patrimonio culturale) realized by ISCR (Central Institute for the Conservation and Restoration); the Italian Landslide Inventory (Progetto IFFI) developed by ISPRA (Italian National Institute for Environmental Protection and Research) and the Regions and Self-Governing Provinces of Italy and the flood hazard zones defined by the Italian River Basin Authorities. Italian landslide inventory contains more than 486,000 landslides affecting an area of about 20,800 km2, equal to 6.9% of Italian territory. In order to estimate the number and type of cultural heritage at risk some GIS processing have been carried out, overlapping information from the above mentioned databases. The analysis provided the following results: Cultural Heritage exposed to landslide risk were estimated to 5.511 (6.6%) while the ones exposed to flood risk results 9.859 (11.7%). Two case studies concerning landslide phenomena affecting important Italian municipalities and the flood risk of historical centre of Rome, have been also analyzed. These results could be used to identify priorities and plan field surveys, detailed studies and monitoring systems, allowing job scheduling of cultural heritage maintenance. This need becomes more and more a necessity taking into account

  3. Otoacoustic emissions in 28 young adults exposed to amplified music.

    PubMed

    Mansfield, J D; Baghurst, P A; Newton, V E

    1999-08-01

    Popular concern about widespread damage to the hearing from exposure to amplified music continues, although there has been little firm evidence of permanent effects in casual listeners. Measurement of transient evoked otoacoustic emissions (TEOAEs) provides a sensitive technique for testing outer hair cell (OHC) function, and was used in this study of 28 young adults aged 18-25 years, whose only significant source of noise exposure was loud music, to look for evidence of poorer cochlear function in those of greater exposure; they provided 27 right ears and 27 left ears suitable for measurement of TEOAE strength. Estimates of subjects' total noise dose were obtained from self-reports of the duration and intensity of their exposure to music and other sources of noise. Ears with greater exposure to loud music showed significantly weaker TEOAEs than less exposed ears in response to a 4 kHz tone burst, or in response to a saturating (82 dBSPL) click if the response was treated with a high-frequency bandpass filter (2-4 kHz) (p<0.05). Differences between more exposed and less exposed groups of ears were most marked in the 2 kHz half-octave band for right ears, and in the 2.8 kHz half-octave band for left ears. A hypothesis is proposed that weakness in TEOAEs as a result of exposure to loud music is seen first in the 2 kHz region of the emission spectrum, and later at higher frequencies; and that for a given amount of exposure, TEOAE weakness (or OHC damage) is more advanced in left ears than in right.

  4. Susuk - black magic exposed "white" by dental radiographs.

    PubMed

    F, Arishiya Thapasum; Mohammed, Faraz

    2014-07-01

    Susuk or charm needles are a facial cum body art widely practiced among women of Malaysia, Brunei, Singapore, Thailand and Indonesia. These are small, needle-shaped metallic talismans inserted subcutaneously in different parts of the body. The concealed art of susuk was "exposed" by routine radiographic examination in the oral and maxillofacial region. This paper reports two such cases of unusual incidental radiographic finding in dental radiographs which were taken on a routine basis as part of the diagnostic work up. This article will also primarily enlighten the importance of radiographs in detecting such charm needles as the wearer keeps the body art a "hidden secret" thereby avoiding misdiagnosis. PMID:25177646

  5. Spectrum of alveolitis in quartz-exposed human subjects.

    PubMed

    Bégin, R O; Cantin, A M; Boileau, R D; Bisson, G Y

    1987-12-01

    To characterize silica-induced alveolitis in human subjects, we studied 22 workers in the granite stone cutting industry of Quebec and compared results with those of 22 manual workers without quartz exposure (group 1). All were nonsmokers and were of comparable age. On the basis of chest roentgenogram, seven were without disease (group 2), nine had silicosis without coalescence/conglomeration (group 3), and six had silicosis with coalescence/conglomeration (group 4). The alveolitis in subsets of silica-exposed workers with distinct clinical stages of disease was found to have distinct biologic characteristics.

  6. Exposed water ice discovered near the south pole of Mars.

    PubMed

    Titus, Timothy N; Kieffer, Hugh H; Christensen, Phillip R

    2003-02-14

    The Mars Odyssey Thermal Emission Imaging System (THEMIS) has discovered water ice exposed near the edge of Mars' southern perennial polar cap. The surface H2O ice was first observed by THEMIS as a region that was cooler than expected for dry soil at that latitude during the summer season. Diurnal and seasonal temperature trends derived from Mars Global Surveyor Thermal Emission Spectrometer observations indicate that there is H2O ice at the surface. Viking observations, and the few other relevant THEMIS observations, indicate that surface H2O ice may be widespread around and under the perennial CO2 cap.

  7. Final results of space exposed experiment developed for students

    NASA Technical Reports Server (NTRS)

    Grigsby, Doris K.

    1993-01-01

    SEEDS was a cooperative endeavor of NASA Headquarters, the NASA Langley Research Center, and the George W. Park Seed Company. Approximately 132,000 SEEDS kits containing Rutger's tomato seeds that had flown on LDEF, as well as similar seeds that had been stored in a climate-controlled warehouse for the same time period, were sent to schools in every state and 30 foreign countries. Student researchers from kindergarten through university compared germination and growth characteristics of the space-exposed and Earth-based seeds and returned data to NASA for analysis. Important scientific information was gained as students reported very little difference between the two seed groups.

  8. Exposed water ice discovered near the south pole of Mars

    USGS Publications Warehouse

    Titus, T.N.; Kieffer, H.H.; Christensen, P.R.

    2003-01-01

    The Mars Odyssey Thermal Emission Imaging System (THEMIS) has discovered water ice exposed near the edge of Mars' southern perennial polar cap. The surface H2O ice was first observed by THEMIS as a region that was cooler than expected for dry soil at that latitude during the summer season. Diurnal and seasonal temperature trends derived from Mars Global Surveyor Thermal Emission Spectrometer observations indicate that there is H2O ice at the surface. Viking observations, and the few other relevant THEMIS observations, indicate that surface H2O ice may be widespread around and under the perennial CO2 cap.

  9. Erosion of graphite surface exposed to hot supersonic hydrogen gas

    NASA Technical Reports Server (NTRS)

    Sharma, O. P.

    1972-01-01

    A theoretical model based on laminar boundary layer flow equations is developed to predict the erosion rate of a graphite (AGCarb-101) surface exposed to a hot supersonic stream of hydrogen gas. The supersonic flow in the nozzle outside the boundary layer formed over the surface of the specimen is determined by assuming one-dimensional isentropic conditions. An overall surface reaction rate expression based on the experimental studies by Clarke and Fox is used to describe the interaction of hydrogen with graphite. A satisfactory agreement is found between the results of the computation, and the available experimental data. Some shortcomings of the model, and further possible improvements are discussed.

  10. Experimental Observation of Hairy Surface Exposed in Airflow

    NASA Astrophysics Data System (ADS)

    Hasegawa, Mitsugu; Sakaue, Hirotaka

    2015-11-01

    The development of drag reduction method is important to reduce the consumption of limited energy in the field of engineering. While active method which needs external energy has received significant attention, passive method which means no external energy use has been focused. As one of the potential passive drag reduction method for offshore structure, aircraft, wind turbine, flexible hair implanted on the object surface has been studied. Here we make hairy surface. We conduct flow visualization to investigate the behavior of hairy surface exposed in wind tunnel. In the presentation, a current status of this experiment will be presented.

  11. Long term health and neurodevelopment in children exposed to antiepileptic drugs before birth

    PubMed Central

    Dean, J; Hailey, H; Moore, S; Lloyd, D; Turnpenny, P; Little, J

    2002-01-01

    Objective: To investigate the frequency of neonatal and later childhood morbidity in children exposed to antiepileptic drugs in utero. Design: Retrospective population based study. Setting: Population of the Grampian region of Scotland. Participants: Mothers taking antiepileptic drugs in pregnancy between 1976 and 2000 were ascertained from hospital obstetric records and 149 (58% of those eligible) took part. They had 293 children whose health and neurodevelopment were assessed. Main outcome measures: Frequencies of neonatal withdrawal, congenital malformations, childhood onset medical problems, developmental delay, and behaviour disorders. Results: Neonatal withdrawal was seen in 20% of those exposed to antiepileptic drugs. Congenital malformations occurred in 14% of exposed pregnancies, compared with 5% of non-exposed sibs, and developmental delay in 24% of exposed children, compared with 11% of non-exposed sibs. After excluding cases with a family history of developmental delay, 19% of exposed children and 3% of non-exposed sibs had developmental delay, 31% of exposed children had either major malformations or developmental delay, 52% of exposed children had facial dysmorphism compared with 25% of those not exposed, 31% of exposed children had childhood medical problems (13% of non-exposed sibs), and 20% had behaviour disorders (5% of non-exposed). Conclusion: Prenatal antiepileptic drug exposure in the setting of maternal epilepsy is associated with developmental delay and later childhood morbidity in addition to congenital malformation. PMID:11950853

  12. Protection of chemolithoautotrophic bacteria exposed to simulated Mars environmental conditions

    NASA Astrophysics Data System (ADS)

    Gómez, Felipe; Mateo-Martí, Eva; Prieto-Ballesteros, Olga; Martín-Gago, Jose; Amils, Ricardo

    2010-10-01

    Current surface conditions (strong oxidative atmosphere, UV radiation, low temperatures and xeric conditions) on Mars are considered extremely challenging for life. The question is whether there are any features on Mars that could exert a protective effect against the sterilizing conditions detected on its surface. Potential habitability in the subsurface would increase if the overlaying material played a protective role. With the aim of evaluating this possibility we studied the viability of two microorganisms under different conditions in a Mars simulation chamber. An acidophilic chemolithotroph isolated from Río Tinto belonging to the Acidithiobacillus genus and Deinococcus radiodurans, a radiation resistant microorganism, were exposed to simulated Mars conditions under the protection of a layer of ferric oxides and hydroxides, a Mars regolith analogue. Samples of these microorganisms were exposed to UV radiation in Mars atmospheric conditions at different time intervals under the protection of 2 and 5 mm layers of oxidized iron minerals. Viability was evaluated by inoculation on fresh media and characterization of their growth cultures. Here we report the survival capability of both bacteria to simulated Mars environmental conditions.

  13. Experiences of being exposed to intimate partner violence during pregnancy

    PubMed Central

    Lidén, Eva; Lundgren, Ingela

    2012-01-01

    In this study a phenomenological approach was used in order to enter deeply into the experience of living with violence during pregnancy. The aim of the study was to gain a deeper understanding of women's experiences of being exposed to intimate partner violence (IPV) during pregnancy. The data were collected through in-depth interviews with five Norwegian women; two during pregnancy and three after the birth. The women were between the age of 20 and 38 years. All women had received support from a professional research and treatment centre. The essential structure shows that IPV during pregnancy is characterized by difficult existential choices related to ambivalence. Existential choices mean questioning one's existence, the meaning of life as well as one's responsibility for oneself and others. Five constituents further explain the essential structure: Living in unpredictability, the violence is living in the body, losing oneself, feeling lonely and being pregnant leads to change. Future life with the child is experienced as a possibility for existential change. It is important for health professionals to recognize and support pregnant women who are exposed to violence as well as treating their bodies with care and respect. PMID:22468147

  14. The Exposed Proteomes of Brachyspira hyodysenteriae and B. pilosicoli.

    PubMed

    Casas, Vanessa; Vadillo, Santiago; San Juan, Carlos; Carrascal, Montserrat; Abian, Joaquin

    2016-01-01

    Brachyspira hyodysenteriae and Brachyspira pilosicoli are well-known intestinal pathogens in pigs. B. hyodysenteriae is the causative agent of swine dysentery, a disease with an important impact on pig production while B. pilosicoli is responsible of a milder diarrheal disease in these animals, porcine intestinal spirochetosis. Recent sequencing projects have provided information for the genome of these species facilitating the search of vaccine candidates using reverse vaccinology approaches. However, practically no experimental evidence exists of the actual gene products being expressed and of those proteins exposed on the cell surface or released to the cell media. Using a cell-shaving strategy and a shotgun proteomic approach we carried out a large-scale characterization of the exposed proteins on the bacterial surface in these species as well as of peptides and proteins in the extracellular medium. The study included three strains of B. hyodysenteriae and two strains of B. pilosicoli and involved 148 LC-MS/MS runs on a high resolution Orbitrap instrument. Overall, we provided evidence for more than 29,000 different peptides pointing to 1625 and 1338 different proteins in B. hyodysenteriae and B. pilosicoli, respectively. Many of the most abundant proteins detected corresponded to described virulence factors and vaccine candidates. The level of expression of these proteins, however, was different among species and strains, stressing the value of determining actual gene product levels as a complement of genomic-based approaches for vaccine design. PMID:27493641

  15. The Impact of Infidelity on Combat-Exposed Service Members.

    PubMed

    Kachadourian, Lorig K; Smith, Brian N; Taft, Casey T; Vogt, Dawne

    2015-10-01

    This study examined relationships between combat-exposed Operation Enduring Freedom/Operation Iraqi Freedom veterans' experiences related to infidelity during deployment (i.e., indicating that a partner was unfaithful or reporting concern about potential infidelity) and postdeployment mental health, as well as the role of subsequent stress exposure and social support in these associations. The sample consisted of 571 individuals (338 men). There were 128 participants (22.2%) who indicated that their partners were unfaithful during their most recent deployment. Of the remaining 443 participants, 168 (37.8%) indicated that they were concerned that their partners might have been unfaithful. Individuals who indicated that their partners were unfaithful exhibited higher levels of posttraumatic stress symptomatology (β = .08; f(2) = .18) and depression symptom severity (β = .09; f(2) = .14), compared to individuals who did not indicate that their partners were unfaithful. For both men and women, reported infidelity was associated with mental health indirectly via postdeployment life stressors, whereas infidelity concerns were indirectly associated with mental health via postdeployment life stressors for men only. Findings suggested that infidelity can have a significant impact on combat-exposed veterans' mental health and highlight the need for additional research on this understudied topic within the military population.

  16. Multiple Endocrine Disrupting Effects in Rats Perinatally Exposed to Butylparaben.

    PubMed

    Boberg, J; Axelstad, M; Svingen, T; Mandrup, K; Christiansen, S; Vinggaard, A M; Hass, U

    2016-07-01

    Parabens comprise a group of preservatives commonly added to cosmetics, lotions, and other consumer products. Butylparaben has estrogenic and antiandrogenic properties and is known to reduce sperm counts in rats following perinatal exposure. Whether butylparaben exposure can affect other endocrine sensitive endpoints, however, remains largely unknown. In this study, time-mated Wistar rats (n = 18) were orally exposed to 0, 10, 100, or 500 mg/kg bw/d of butylparaben from gestation day 7 to pup day 22. Several endocrine-sensitive endpoints were adversely affected. In the 2 highest dose groups, the anogenital distance of newborn male and female offspring was significantly reduced, and in prepubertal females, ovary weights were reduced and mammary gland outgrowth was increased. In male offspring, sperm count was significantly reduced at all doses from 10 mg/kg bw/d. Testicular CYP19a1 (aromatase) expression was reduced in prepubertal, but not adult animals exposed to butylparaben. In adult testes, Nr5a1 expression was reduced at all doses, indicating persistent disruption of steroidogenesis. Prostate histology was altered at prepuberty and adult prostate weights were reduced in the high dose group. Thus, butylparaben exerted endocrine disrupting effects on both male and female offspring. The observed adverse developmental effect on sperm count at the lowest dose is highly relevant to risk assessment, as this is the lowest observed adverse effect level in a study on perinatal exposure to butylparaben. PMID:27122241

  17. Thyroid neoplasia in Marshall Islanders exposed to nuclear fallout

    SciTech Connect

    Hamilton, T.E.; van Belle, G.; LoGerfo, J.P.

    1987-08-07

    We studied the risk of thyroid neoplasia in Marshall Islanders exposed to radioiodines in nuclear fallout from the 1954 BRAVO thermonuclear test. We screened 7266 Marshall Islanders for thyroid nodules; the islanders were from 14 atolls, including several southern atolls, which were the source of the best available unexposed comparison group. Using a retrospective cohort design, we determined the prevalence of thyroid nodularity in a subgroup of 2273 persons who were alive in 1954 and who therefore were potentially exposed to fallout from the BRAVO test. For those 12 atolls previously thought to be unexposed to fallout, the prevalence of thyroid nodules ranged from 0.9% to 10.6%. Using the distance of each atoll from the test site as a proxy for the radiation dose to the thyroid gland, a weighted linear regression showed an inverse linear relationship between distance and the age-adjusted prevalence of thyroid nodules. Distance was the strongest single predictor in logistic regression analysis. A new absolute risk estimate was calculated to be 1100 excess cases/Gy/y/1 X 10(6) persons (11.0 excess cases/rad/y/1 million persons), 33% higher than previous estimates. We conclude that an excess of thyroid nodules was not limited only to the two northern atolls but extended throughout the northern atolls; this suggests a linear dose-response relationship.

  18. Gender-related behavior in women exposed prenatally to diethylstilbestrol.

    PubMed Central

    Newbold, R R

    1993-01-01

    Accumulating evidence in experimental animals over the past three decades suggests that mammalian brain development and differentiation of the central nervous system are influenced by perinatal exposure to sex hormones. Hence, changes in human behavioral patterns may be associated with prenatal exposure to estrogenic substances such as diethylstilbestrol (DES). This paper reviews relevant studies from a series of laboratories and finds that no clear-cut differences can be demonstrated to date between unexposed and DES-exposed women in gender-related behavior, although the physical and psychological impact of the problems associated with exposure to DES are well documented. If both prenatal and postnatal influences such as social, economic, and environmental factors are taken into consideration, individual variation is more apparent than differences in gender-related behavior between unexposed and DES-exposed women. In summary, gender-related behavior is determined by a complex array of interacting factors, and prenatal influences are only one of many developmental events. More studies are needed using larger populations with carefully controlled selection criteria to suggest a direct role of prenatal DES exposure on subsequent gender-related behavior. Images p208-a PMID:8404755

  19. Increased gluconeogenesis in rats exposed to hyper-G stress

    NASA Technical Reports Server (NTRS)

    Daligcon, B. C.; Oyama, J.; Hannak, K.

    1985-01-01

    The effect of gluconeogenesis on the levels of plasma glucose and liver glycogen was studied in rats exposed to hyper-G stress. Incorporation of lactate, alanine, or glycerol, labeled with C-14, into plasma glucose and liver glycogen was measured in rats centrifuged at 3.1 G for 0.25, 0.50, and 1.0-hr periods, and was compared to noncentrifuged controls injected with appropriate glycogen precursors. It was found that exposure to G-stress leads to increased incorporation from all three substrates into both plasma glucose and liver glycogen. These early incorporation increases were blocked upon pre-G administration of 5-methoxyindole-2-carboxylic acid, a gluconeogenesis inhibitor, or propanolol, a beta-adrenergic blocker, as well as by adrenodemedullation. Results indicate that the rapid rise in plasma glucose, as well as in liver glycogen in rats exposed to hyper-G stress is due to an increased rate of gluconeogenesis, and that epinephrine, released in response to hyper-G-induced activation of the sympathetic-adrenal system, plays a dominant role during the early stages of hyper-G stress.

  20. Primary stress responses in Arabidopsis thaliana exposed to gamma radiation.

    PubMed

    Vanhoudt, Nathalie; Horemans, Nele; Wannijn, Jean; Nauts, Robin; Van Hees, May; Vandenhove, Hildegarde

    2014-03-01

    As the environment is inevitably exposed to ionizing radiation from natural and anthropogenic sources, it is important to evaluate gamma radiation induced stress responses in plants. The objective of this research is therefore to investigate radiation effects in Arabidopsis thaliana on individual and subcellular level by exposing 2-weeks-old seedlings for 7 days to total doses of 3.9 Gy, 6.7 Gy, 14.8 Gy and 58.8 Gy and evaluating growth, photosynthesis, chlorophyll a, chlorophyll b and carotenoid concentrations and antioxidative enzyme capacities. While the capacity of photosystem II (PSII measured as Fv/Fm) remained intact, plants started optimizing their photosynthetic process at the lower radiation doses by increasing the PSII efficiency (φPSII) and the maximal electron transport rate (ETRmax) and by decreasing the non-photochemical quenching (NPQ). At the highest radiation dose, photosynthetic parameters resembled those of control conditions. On subcellular level, roots showed increased superoxide dismutase (SOD) and ascorbate peroxidase (APX) capacities under gamma irradiation but catalase (CAT), syringaldazine peroxidase (SPX) and guaiacol peroxidase (GPX) activities, on the other hand, decreased. In the leaves no alterations were observed in SOD, CAT and SPX capacities, but GPX was highly affected. Based on these results it seems that roots are more sensitive for oxidative stress under gamma radiation exposure than leaves.

  1. Chronic toxic encephalopathy in a painter exposed to mixed solvents.

    PubMed Central

    Feldman, R G; Ratner, M H; Ptak, T

    1999-01-01

    This paper describes symptoms and findings in a 57-year-old painter who had been exposed to various organic solvents for over 30 years. He began to work as a painter at 16 years of age, frequently working in poorly ventilated areas; he used solvents to remove paint from the skin of his arms and hands at the end of each work shift. The patient and his family noticed impaired short-term memory function and changes in affect in his early forties, which progressed until after he stopped working and was thus no longer exposed to paints and solvents. After the patient's exposures had ended, serial neuropsychological testing revealed persistent cognitive deficits without evidence of further progression, and improvement in some domains. Magnetic resonance imaging revealed global and symmetrical volume loss, involving more white than gray matter. The findings in this patient are consistent with chronic toxic encephalopathy and are differentiated from other dementing processes such as Alzheimer's disease, multi-infarct (vascular) dementia, and alcoholic dementia. Previous descriptions in the literature of persistent neurobehavioral effects associated with chronic exposure to organic solvents corroborate the findings in this case. Images Figure 2 PMID:10210698

  2. The Immune System of HIV-Exposed Uninfected Infants

    PubMed Central

    Abu-Raya, Bahaa; Kollmann, Tobias R.; Marchant, Arnaud; MacGillivray, Duncan M.

    2016-01-01

    Infants born to human immunodeficiency virus (HIV) infected women are HIV-exposed but the majority remains uninfected [i.e., HIV-exposed uninfected (HEU)]. HEU infants suffer greater morbidity and mortality from infections compared to HIV-unexposed (HU) peers. The reason(s) for these worse outcomes are uncertain, but could be related to an altered immune system state. This review comprehensively summarizes the current literature investigating the adaptive and innate immune system of HEU infants. HEU infants have altered cell-mediated immunity, including impaired T-cell maturation with documented hypo- as well as hyper-responsiveness to T-cell activation. And although prevaccination vaccine-specific antibody levels are often lower in HEU than HU, most HEU infants mount adequate humoral immune response following primary vaccination with diphtheria toxoid, haemophilus influenzae type b, whole cell pertussis, measles, hepatitis B, tetanus toxoid, and pneumococcal conjugate vaccines. However, HEU infants are often found to have lower absolute neutrophil counts as compared to HU infants. On the other hand, an increase of innate immune cytokine production and expression of co-stimulatory markers has been noted in HEU infants, but this increase appears to be restricted to the first few weeks of life. The immune system of HEU children beyond infancy remains largely unexplored. PMID:27733852

  3. TP53 mutations in workers exposed to occupational carcinogens.

    PubMed

    Vähäkangas, Kirsi

    2003-03-01

    In some cases, evidence exists that exogenous carcinogenic exposures contribute to the mutation spectrum of the TP53 gene (p53) in human cancers. Although the clearest examples come from dietary and environmental sources, only a restricted number of papers have concentrated specifically on TP53 mutations in tumors from workers exposed to occupational carcinogens. In populations exposed to dietary aflatoxin B1 with liver cancer (AFB1) and ultraviolet (UV)-radiation with skin cancer, a single specific-looking TP53 mutation has been described in some of the tumors. Whether these fingerprints in the TP53 gene can be used to reveal an occupational etiology remains to be shown. In other cases, although differences in the TP53 mutation spectrum exist, they are more diffuse and difficult to interpret at this point. For instance, cigarette smoking seems to induce long-lasting molecular footprints in TP53. However, their use to rule out other occupational exposures as etiological factors in occupational cancers is still very questionable, especially due to the putative synergistic effects of cigarette smoke with other carcinogens. Although interesting implications of possible typical mutation spectra among cancers with other occupational etiologies exist, the data are scanty and await further development of TP53 mutation databases.

  4. The Impact of Infidelity on Combat-Exposed Service Members.

    PubMed

    Kachadourian, Lorig K; Smith, Brian N; Taft, Casey T; Vogt, Dawne

    2015-10-01

    This study examined relationships between combat-exposed Operation Enduring Freedom/Operation Iraqi Freedom veterans' experiences related to infidelity during deployment (i.e., indicating that a partner was unfaithful or reporting concern about potential infidelity) and postdeployment mental health, as well as the role of subsequent stress exposure and social support in these associations. The sample consisted of 571 individuals (338 men). There were 128 participants (22.2%) who indicated that their partners were unfaithful during their most recent deployment. Of the remaining 443 participants, 168 (37.8%) indicated that they were concerned that their partners might have been unfaithful. Individuals who indicated that their partners were unfaithful exhibited higher levels of posttraumatic stress symptomatology (β = .08; f(2) = .18) and depression symptom severity (β = .09; f(2) = .14), compared to individuals who did not indicate that their partners were unfaithful. For both men and women, reported infidelity was associated with mental health indirectly via postdeployment life stressors, whereas infidelity concerns were indirectly associated with mental health via postdeployment life stressors for men only. Findings suggested that infidelity can have a significant impact on combat-exposed veterans' mental health and highlight the need for additional research on this understudied topic within the military population. PMID:26397362

  5. Proportional mortality patterns among chemical plant workers exposed to formaldehyde.

    PubMed Central

    Marsh, G M

    1982-01-01

    To examine the possible health risks associated with occupational exposure to formaldehyde a proportional mortality analysis was conducted on deaths occurring between 1950 and 1976 among 136 men who had been employed a month or more in one of five formaldehyde-related areas of a large chemical producing plant located in Springfield, Massachusetts, USA. Overall, no statistically significant excesses or deficits in proportional mortality were observed among the formaldehyde-exposed group based on comparisons with both United States men and men from the local county area. In addition, no important differences in mortality were observed among this group when comparisons were made with 456 male decedents from the same plant who had not had a month or more of formaldehyde exposure. Within the calendar period examined, no deaths from sinonasal cancer were observed among the chemical workers studied nor was mention made on any death certificate of sinonasal cancer as a contributory cause of death. No important excesses, trends, or patterns in cancer mortality were observed among white male formadelhyde-exposed workers when consideration was given to age and time period of death, type and duration of formaldehyde exposure, and the lapse period from the onset of the first formaldehyde-related job assignment. Although certain limitations of this study do not allow definite conclusions to be drawn, the results indicate no trends or patterns in proportional mortality that could be directly linked to exposures to formaldehyde. PMID:7138792

  6. Behavioral modification of estuarine fish exposed to sulfur dioxide

    SciTech Connect

    Hall, L.W. Jr.; Burton, D.T.; Graves, W.C.; Margrey, S.L.

    1984-01-01

    This study was designed to determine the avoidance responses of juvenile striped bass (Morone saxatilis) and Atlantic menhaden (Brevoortia tyrannus) exposed to sulfur dioxide (sulfite) at acclimation temperatures of 15, 20, 25, and 30/sup 0/C. Predictive models were developed and compared for each species at each acclimation temperature. Striped bass avoided 2.2, 2.3, 3.0, and 3.5 mg sulfite/l at 15, 20, 25, and 30/sup 0/C, respectively. Atlantic menhaden avoided 3.2, 3.6, 2.9, and 3.0 mg sulfite/l at acclimation temperatures of 15, 20, 25, and 30/sup 0/C, respectively. Acclimation temperature was an important factor influencing the avoidance response of each species exposed to sulfur dioxide. Striped bass avoided lower concentrations of sulfite than Atlantic menhaden at 15 and 20/sup 0/C. Both species avoided approximately the same concentration of sulfite at 25/sup 0/C. Atlantic menhaden avoided lower concentrations of sulfur dioxide than striped bass at 30/sup 0/C. 24 references, 2 figures, 3 tables.

  7. Spontaneous abortions among nickel-exposed female refinery workers.

    PubMed

    Vaktskjold, Arild; Talykova, Ljudmila V; Chashchin, Valerij P; Odland, Jon Ø; Nieboer, Evert

    2008-04-01

    A case-control study to investigate whether women employed in nickel-exposed work areas in early pregnancy are at elevated risk of spontaneous abortion (SA). Data about pregnancy outcome and maternal factors were obtained about each delivery and SA from women in selected work places. Each pregnancy record was assigned a categorical nickel (Ni) exposure rating according to the women's occupations at pregnancy onset. The guidelines were the water-soluble Ni subfraction of the inhalable aerosol fraction obtained by personal monitoring for nickel- and copper-refinery workers or/and measured urinary-Ni concentrations. The unadjusted odds ratio for the association between the maternal exposure to Ni and an SA for Ni-exposed women was 1.38 (95% confidence interval: 1.04-1.84), and the adjusted was 1.14 (0.95-1.37). In conclusion, there was no statistical association between maternal occupational exposure to water-soluble Ni in early pregnancy and the risk of self-reported SA. The findings do not exclude the possibility of a weak excess risk, or a risk in the first weeks of pregnancy. PMID:18365800

  8. [Species sensitive distribution for aquatic biota exposed to triazophos].

    PubMed

    Chen, Bo-Yu; Zheng, Si-Rui; Niu, Xi-Cheng; Zhao, Jin-Song

    2011-04-01

    The increasing pollution of organophosphorus pesticides (OP) in water have been of concerns. Taking the widely used triazophos as the object, a species sensitivity distribution (SSD) model was developed using a log-logistic distribution based on the median effective concentrations (EC50) of triazophos to aquatic species at various trophic levels, and then the model was tested and evaluated using probability plots and good-of-fit tests. The results showed that the SSD for aquatic biota exposed to triazophos was well fitted by a log-logistic distribution, which was totally determined by the two parameters, alpha = -0.4788 and beta = 0.7546, with standard error 0.2381 and 0.1078 respectively. Based on the SSD model, the hazardous concentration for 5% of the species (HC5) and the criteria maximum concentration (CMC) of triazophos were 1.992 x 10(-3) mg/L and 9.96 x 10(-4) mg/L, respectively. Through comparing the HC5 and CMC with the safe concentration for single-species, it could be found that environmental quality criteria derived from the SSD model was more strict, and closed to the real ecological environment. In addition, according to the reported data, the potentially affected fraction (PAF) of species exposed to triazophos in the Laizhou Bay (Bohai Sea, China) area was 0.36% predicted by the SSD model, and the corresponding risk might not be significant. PMID:21717754

  9. An update of mortality among chemical workers exposed to benzene.

    PubMed

    Bond, G G; McLaren, E A; Baldwin, C L; Cook, R R

    1986-10-01

    Mortality was updated to the end of 1982 for 594 employees exposed to benzene who had been studied previously and for an additional 362 exposed workers not studied previously. Cause specific mortality comparisons were made using United States white male, age, and calendar year adjusted rates. Total mortality was observed to have been significantly below expectation, and this was particularly evident for deaths from accidental causes. Mortality from skin cancer was significantly raised, although there were no unusual or common characteristics among the affected individuals which would suggest a link with exposure to benzene. A non-significant excess of total deaths from leukaemia was noted based on four observed cases; however, all four were myelogenous leukaemias and this represented a significant excess in that subcategory. These and other deaths of possible interest are reviewed in detail. Analyses by work area, duration of exposure, and cumulative dose index did not show patterns suggestive of a causal association between exposure to benzene and any particular cause of death.

  10. An update of mortality among chemical workers exposed to benzene.

    PubMed Central

    Bond, G G; McLaren, E A; Baldwin, C L; Cook, R R

    1986-01-01

    Mortality was updated to the end of 1982 for 594 employees exposed to benzene who had been studied previously and for an additional 362 exposed workers not studied previously. Cause specific mortality comparisons were made using United States white male, age, and calendar year adjusted rates. Total mortality was observed to have been significantly below expectation, and this was particularly evident for deaths from accidental causes. Mortality from skin cancer was significantly raised, although there were no unusual or common characteristics among the affected individuals which would suggest a link with exposure to benzene. A non-significant excess of total deaths from leukaemia was noted based on four observed cases; however, all four were myelogenous leukaemias and this represented a significant excess in that subcategory. These and other deaths of possible interest are reviewed in detail. Analyses by work area, duration of exposure, and cumulative dose index did not show patterns suggestive of a causal association between exposure to benzene and any particular cause of death. PMID:3465366

  11. Radiographic abnormalities among construction workers exposed to quartz containing dust

    PubMed Central

    Tjoe, N; Burdorf, A; Parker, J; Attfield, M; van Duivenbooden, C; Heederik, D

    2003-01-01

    Background: Construction workers are exposed to quartz containing respirable dust, at levels that may cause fibrosis in the lungs. Studies so far have not established a dose-response relation for radiographic abnormalities for this occupational group. Aims: To measure the extent of radiographic abnormalities among construction workers primarily exposed to quartz containing respirable dust. Methods: A cross sectional study on radiographic abnormalities indicative of pneumoconiosis was conducted among 1339 construction workers mainly involved in grinding, (jack)-hammering, drilling, cutting, sawing, and polishing. Radiological abnormalities were determined by median results of the 1980 International Labour Organisation system of three certified "B" readers. Questionnaires were used for assessment of occupational history, presence of respiratory diseases, and symptoms and smoking habits. Results: An abnormality of ILO profusion category 1/0 and greater was observed on 10.2% of the chest radiographs, and profusion category of 1/1 or greater on 2.9% of the radiographs. The average duration of exposure of this group was 19 years and the average age was 42. The predominant type of small opacities (irregularly shaped) is presumably indicative of mixed dust pneumoconiosis. The prevalence of early signs of nodular silicosis (small rounded opacities of category 1/0 or greater) was low (0.8%). Conclusions: The study suggests an elevated risk of radiographic abnormalities among these workers with expected high exposure. An association between radiographic abnormalities and cumulative exposure to quartz containing dust from construction sites was observed, after correction for potentially confounding variables. PMID:12771392

  12. Test system for exposing fish to resuspended, contaminated sediment

    USGS Publications Warehouse

    Cope, W.G.; Wiener, J.G.; Steingraeber, M.T.

    1996-01-01

    We describe a new test system for exposing fish to resuspended sediments and associated contaminants. Test sediments were resuspended by revolving test chambers on rotating shafts driven by an electric motor. The timing, speed, and duration of test-chamber revolution were controlled by a rheostat and electronic timer. Each chamber held 45 litres of water and accommodated about 49 g of test fish. The system described had three water baths, each holding six test chambers. We illustrate the performance of this system with results from a 28-day test in which juvenile bluegills Lepomis macrochirus were exposed to resuspended, riverine sediments differing in texture and cadmium content. The test had one sediment-free control and five sediment treatments, with three replicates (chambers) per treatment and 25 fish per replicate. Two-thirds (30 litres) of the test water and sediment in each chamber was renewed weekly. The mean concentration of total suspended solids (TSS) did not vary among treatments; the grand-mean TSS in the five sediment treatments was 975 mg litre-1, similar to the target TSS of 1000 mg litre-1. At the end of the test, an average of 50% of the introduced cadmium was associated with the suspended sediment compartment, whereas the filtered (0.45 μm) water contained 0.4% and bluegills 1.8% of the cadmium.

  13. The Exposed Proteomes of Brachyspira hyodysenteriae and B. pilosicoli

    PubMed Central

    Casas, Vanessa; Vadillo, Santiago; San Juan, Carlos; Carrascal, Montserrat; Abian, Joaquin

    2016-01-01

    Brachyspira hyodysenteriae and Brachyspira pilosicoli are well-known intestinal pathogens in pigs. B. hyodysenteriae is the causative agent of swine dysentery, a disease with an important impact on pig production while B. pilosicoli is responsible of a milder diarrheal disease in these animals, porcine intestinal spirochetosis. Recent sequencing projects have provided information for the genome of these species facilitating the search of vaccine candidates using reverse vaccinology approaches. However, practically no experimental evidence exists of the actual gene products being expressed and of those proteins exposed on the cell surface or released to the cell media. Using a cell-shaving strategy and a shotgun proteomic approach we carried out a large-scale characterization of the exposed proteins on the bacterial surface in these species as well as of peptides and proteins in the extracellular medium. The study included three strains of B. hyodysenteriae and two strains of B. pilosicoli and involved 148 LC-MS/MS runs on a high resolution Orbitrap instrument. Overall, we provided evidence for more than 29,000 different peptides pointing to 1625 and 1338 different proteins in B. hyodysenteriae and B. pilosicoli, respectively. Many of the most abundant proteins detected corresponded to described virulence factors and vaccine candidates. The level of expression of these proteins, however, was different among species and strains, stressing the value of determining actual gene product levels as a complement of genomic-based approaches for vaccine design. PMID:27493641

  14. Recall bias in exposed subjects following a toxic exposure incident

    SciTech Connect

    Hopwood, D.G.; Guidotti, T.L.

    1988-05-01

    Attempts to reconstruct health effects following toxic exposure incidents may be subject to bias from distorted or incomplete recollection. The authors examined recall in 22 of 31 subjects exposed to fumes from ruptured drums containing nitric acid during a U.S. Environmental Protection Agency-supervised hazardous waste site clean up operation in August 1983. Exposed subjects were interviewed by emergency room staff immediately after the episode and the next morning by telephone by a public health epidemiologists. Six months later, the subjects were again interviewed by telephone and asked to report the symptoms they had experienced during the incident. For each respondent, symptoms recalled at 6 mo were compared to symptoms reported at the time. They found a low level of agreement compared to that expected by chance, associated with significant nonrandom differences in the distribution of responses consistently favoring selective recall on the later interview. They conclude that allowing time to elapse before obtaining data on individual symptoms following exposure may lead to a significant bias in response.

  15. Behavioral modification of estuarine fish exposed to sulfur dioxide.

    PubMed

    Hall, L W; Burton, D T; Graves, W C; Margrey, S L

    1984-01-01

    This study was designed to determine the avoidance responses of juvenile striped bass (Morone saxatilis) and Atlantic menhaden (Brevoortia tyrannus) exposed to sulfur dioxide (sulfite) at acclimation temperatures of 15, 20, 25, and 30 degrees C. Predictive models were developed and compared for each species at each acclimation temperature. Striped bass avoided 2.2, 2.3, 3.0, and 3.5 mg sulfite/l at 15, 20, 25, and 30 degrees C, respectively. Atlantic menhaden avoided 3.2, 3.6, 2.9, and 3.0 mg sulfite/l at acclimation temperatures of 15, 20, 25, and 30 degrees C, respectively. Acclimation temperature was an important factor influencing the avoidance response of each species exposed to sulfur dioxide. Striped bass avoided lower concentrations of sulfite than Atlantic menhaden at 15 and 20 degrees C. Both species avoided approximately the same concentration of sulfite at 25 degrees C. Atlantic menhaden avoided lower concentrations of sulfur dioxide than striped bass at 30 degrees C. PMID:6492212

  16. Prevalence of tinnitus in workers exposed to noise and organophosphates

    PubMed Central

    Delecrode, Camila Ribas; de Freitas, Thais Domingues; Frizzo, Ana Claúdia Figueiredo; Cardoso, Ana Claúdia Vieira

    2012-01-01

    Summary Introduction: Research on the workplace has emphasized the effects of noise exposure on workers' hearing, but has not considered the effects of agrochemicals. Aim: To evaluate and correlate the hearing level and tinnitus of workers exposed simultaneously to noise and organophosphates in their workplace and to measure tinnitus distress on their quality of life. Method: A retrospective clinical study. We evaluated 82 organophosphate sprinklers from the São Paulo State Regional Superintendence who were active in the fight against dengue and who were exposed to noise and organophosphates. We performed pure tone audiometry and applied the translated THI (Tinnitus Handicap Inventory) questionnaire. Results: Of the sample, 28.05% reported current tinnitus or had presented tinnitus, and the workers with tinnitus had an increased incidence of abnormal audiometry. The average hearing threshold for the 4–8-kHz frequency range of the workers with current tinnitus was higher than that of the others, and was most affected at the 4-kHz frequency. The THI score ranged 0–84, with an average score of 13.1. Twelve (52.17%) workers had THI scores consistent with discrete handicap. Conclusion: There is an increased incidence of abnormal pure tone audiometry in workers with tinnitus, and its impact on the workers' quality of life was discrete. The correlation between average hearing threshold and tinnitus distress was weak. PMID:25991953

  17. Assessment of genotoxic effects of lead in occupationally exposed workers.

    PubMed

    Chinde, Srinivas; Kumari, Monika; Devi, Kanapuram Rudrama; Murty, Upadhyayula Suryanarayana; Rahman, Mohammed Fazlur; Kumari, Srinivas Indu; Mahboob, Mohammed; Grover, Paramjit

    2014-10-01

    The genotoxicological effects in 200 lead acid storage battery recycling and manufacturing industry workers in Hyderabad along with matched 200 controls were studied. The genetic damage was determined by comet, micronucleus (MN), and chromosomal aberration (CA) test in peripheral blood lymphocytes (PBL). The MN test was also carried out in buccal epithelial cells (BECs). Pb in ambient air, blood Pb (B-Pb) concentrations, and hematological parameters were measured. The superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), and malondialdehyde (MDA) formed were also studied. The results of the present study showed that there was a statistically significant (P < 0.01) increase in mean percent tail DNA, frequency of CA, and MN in PBL as well as in BEC as compared to controls. Pb in ambient air and B-Pb concentrations were found to be significantly higher (P < 0.01). The hematocrit, hemoglobin, and red blood cell values were significantly lowered in Pb-exposed workers in comparison to controls. SOD, GPx, and CAT levels were significantly decreased while GSH and MDA levels increased in exposed group when compared to control group. The present study suggests that environmental health standards should be enforced to control Pb contamination from battery industries to reduce human health risk.

  18. Increased medication use in a community environmentally exposed to chemicals.

    PubMed

    Bowler, Rosemarie M; Gysens, Sabine; Hartney, Christopher; Ngo, Long; Rauch, Stephen S; Midtling, John

    2002-10-01

    An epidemiological health study compared the health status of residents of a town exposed to an accidental Catacarb chemical release from an adjacent oil refinery, with the health status of demographically similar residents of an unexposed town in the region. Few studies of Catacarb's effects on humans exist; however, animal studies have shown it to be a respiratory, gastro-intestinal, dermatological and visual irritant. As part of the study, health questionnaires assessing pre- and post exposure symptoms, illnesses and medication use were mailed to residents in both towns. Medication use is sometimes reported to be a more objective and reliable measure of health outcomes. The current paper compared medication use of exposed and unexposed residents. Significant increases after exposure were found in the use of the following medications: antacid, asthma medication, cough and cold medication, eye medication, headache medication and sleep medication. These increases were consistent with reported symptoms, albeit of greater magnitude; no increase in medication use for other illnesses was reported. Medication use in this sample was consistent with patients' report of symptoms and may be a better measure of outcome. PMID:12502236

  19. Neural Tube Defects In Mice Exposed To Tap Water

    PubMed Central

    Mallela, Murali K; Werre, Stephen R; Hrubec, Terry C

    2010-01-01

    In May of 2006 we suddenly began to observe neural tube defects (NTDs) in embryos of untreated control mice. We hypothesized the mice were being exposed unknowingly to a teratogenic agent and investigated the cause. Our results suggested that NTDs were not resulting from bedding material, feed, strain or source of the mice. Additionally, mice were negative for routine and comprehensive screens of pathogens. To further test whether the NTDs resulted from infectious or genetic cause localized to our facility, we obtained three strains of timed pregnant mice from commercial suppliers located in 4 different states. All strains and sources of mice arrived in our laboratory with NTDs, implying that commercially available mice were possibly exposed to a teratogen prior to purchase. Our investigation eventually concluded that exposure to tap water was causing the NTDs. The incidence of NTDs was greatest in purchased mice provided tap water and lowest in purchased mice provided distilled deionized water (DDI). Providing mice DDI water for two generations (F2-DDI) eliminated the NTDs. When F2-DDI mice were provided tap water from three different urban areas prior to breeding, their offspring again developed NTDs. Increased length of exposure to tap water significantly increased the incidence of NTDs. These results indicate that a contaminant in municipal tap water is likely causing NTDs in mice. The unknown teratogen appears to have a wide geographic distribution but has not yet been identified. Water analysis is currently underway to identify candidate contaminants that might be responsible for the malformations. PMID:20549630

  20. Ultimate collapse of offshore structures exposed to fire

    SciTech Connect

    Amdahl, J.; Eberg, E.; Holmaas, T.; Landroe, H.; Ulfsnes, M.

    1995-12-31

    A systematic validation of the computer program for analysis of mechanical response USFOS is presented. It is based upon a nonlinear finite element formulation and is capable of predicting total collapse, taking systems effects including force redistribution caused by failing members into account. For acceptance of the method it is vital that component behavior is predicted reliably. For this purpose the element formulation used is calibrated such that buckling curves for fire exposed columns and beam-column behavior are reproduced accurately. As a part of the verification of the program a laboratory test with a three dimensional frame representative of the upper part of a four-legged jacket is carried out. The structure is exposed to a gas pool fire at sea level close to one leg until total collapse takes place. A description of the test is given along with numerically predicted structural response. Some preliminary results from the experiment are also presented. Finally, the use of the integrated fire analysis system is illustrated by application to an actual offshore structure.

  1. Asbestos-exposed populations: prevention, care, and compensation

    SciTech Connect

    Richter, E.D.; Tulchinsky, T.; Goldsmith, J.R.; Yaffe, Y.

    1984-05-01

    In Israel, the prevention and care of asbestos-associated diseases with latency periods of one to four decades (asbestosis, mesothelioma, increased frequency of cancer of the lung and other sites) are not satisfactory, and new national policies are required. Such policies have three major goals: (a) elimination or reduction of exposure to asbestos dust; (b) measures to promote cessation or drastic reduction of cigarette smoking among those currently or formerly exposed; and (c) equitable compensation for the consequences of past exposures. The practical elements of a program to achieve these three goals include (a) exposure standards and control technology; (b) identification of sources, routes, and levels of exposure and groups at risk; (c) compensation and job security; (d) medical monitoring and follow-up; (e) smoking cessation; (f) selective substitution of other substances for asbestos; and (g) establishment of a panel for policy supervision and the overseeing of compensation programs. Delay in implementation risks higher death rates for asbestosis and cancer among previously exposed workers, greater exposure among current workers, loss of experienced workers from the work force, and unnecessary hardship for families not adequately compensated.

  2. Characterization of Specimens Exposed in a Li Loop

    SciTech Connect

    Unocic, Kinga A; Lance, Michael J; Pint, Bruce A

    2013-01-01

    A monometallic V-4Cr-4Ti thermal convection loop was run for 2,350 h with a peak temperature of 700 C and Li flow rate of 2-3 cm/s. Specimens of V-4Cr-4Ti exposed in the hot and cold leg were tensile tested in vacuum at 500 C showing an increase in the 0.2% yield and ultimate tensile strengths and a decrease in the serration amplitude with decreasing exposure temperature in the loop. However, only minor changes in ductility were measured. With the higher temperature exposures, there was a decrease in Vickers hardness measured but little change in the grain size. Characterization of the microstructure after exposure at 627 C in the loop showed an increase in the density of Ti- and N-rich grain boundary and matrix precipitates near the specimen surface after exposure corresponding to an increase in the hardness in the near-surface region. Two-layer V/Y2O3 coatings on V-4Cr-4Ti substrates also were exposed in the loop and initial room temperature characterization has been conducted.

  3. Turning Rate Dynamics of Zebrafish Exposed to Ethanol

    NASA Astrophysics Data System (ADS)

    Mwaffo, Violet; Porfiri, Maurizio

    2015-06-01

    Zebrafish is emerging as a species of choice in alcohol-related pharmacological studies. In these studies, zebrafish are often exposed to acute ethanol treatments and their activity scored during behavioral assays. Computational modeling of zebrafish behavior is expected to positively impact these efforts by offering a predictive toolbox to plan hypothesis-driven studies, reduce the number of subjects, perform pilot trials, and refine behavioral screening. In this work, we demonstrate the use of the recently proposed jump persistent turning walker to model the turning rate dynamics of zebrafish exposed to acute ethanol administration. This modeling framework is based on a stochastic mean reverting jump process to capture the sudden and large changes in orientation of swimming zebrafish. The model is calibrated on an available experimental dataset of 40 subjects, tested at different ethanol concentrations. We demonstrate that model parameters are modulated by ethanol administration, whereby both the relaxation rate and jump frequency of the turning rate dynamics are influenced by ethanol concentration. This effort offers a first evidence for the possibility of complementing zebrafish pharmacological research with computational modeling of animal behavior.

  4. Memory deficit in Swiss mice exposed to tannery effluent.

    PubMed

    Rabelo, Letícia Martins; Costa E Silva, Bianca; de Almeida, Sabrina Ferreira; da Silva, Wellington Alves Mizael; de Oliveira Mendes, Bruna; Guimarães, Abraão Tiago Batista; da Silva, Anderson Rodrigo; da Silva Castro, André Luis; de Lima Rodrigues, Aline Sueli; Malafaia, Guilherme

    2016-01-01

    Although it is known that tannery effluents constitute highly toxic pollutants whose effects in humans represent public health problems in several countries, studies involving experimental mammalian models are rare. In this context, the objective of the present study was to assess the effect of the exposure to tannery effluent on the memory of male and female Swiss mice. Animals of each sex were distributed into two experimental groups: the control group, in which the animals received only drinking water and the effluent group, in which the mice received 1% of gross tannery effluent diluted in water. The animals were exposed to the effluent by gavage, oral dosing, for 15days, ensuring the administration of 0.1mL of liquid (water or effluent)/10g of body weight/day. On the 14th and 15th experimental days the animals were submitted to the object recognition test. It was observed that the new object recognition indices calculated for the animals exposed to the effluent (males and females) were significantly lower than those obtained with the control group. The exposure to tannery effluent caused memory deficit in Swiss mice in a similar way for both sexes, reinforcing previous findings that these pollutants affect the central nervous system. It contributes to the knowledge in the area by attesting harmful effects to the cognition of such animals. PMID:27063058

  5. Cerebral blood flow in patients (PTS) exposed to neurotoxic chemicals

    SciTech Connect

    Heuser, G.; Mena, I.; Thomas, C.

    1994-05-01

    Exposure to neurotoxic chemicals as pesticides, glues, solvents, etc. are known to induce neurologic and psychiatric symptomatology. We report on 72 pts, 33 young pts, 8 males, and 26 females, age 55 (7) yrs, 15 of them exposed to pesticides, and 37 to solvents. They were studied with quantitative and qualitative analysis of rCBF performed with 30 mCi of Xe-133 (Xe) by inhalation followed by 30 mCi of Tc-HMPAO given IV. Imaging was performed with a brain dedicated system, and distribution of rCBF was assessed with automatic ROI definition, and HMPAO normalized to maximal pixel activity in the brain. Results of Xe rCBF are expressed as mean and (S.D.) in ml/min/100g, and HMPAO as mean and (S.D.) uptake per ROI and compared with age-matched controls, 10 young and 20 elderly individuals, and also to a group of 36 elderly chronic fatigue pts (CFS), and 26 depression pts. CBF was diminished in young and elderly, 45 (7) and 40 (7) ml/min 100g, p<0.02 for both groups. Thus we conclude that pts exposed to chemicals present with diminished CBF, worse in elderly in the right dorsal frontal and parietal lobes, and in young, in left dorsal frontal and temporal lobes. These findings are significantly different from observations in pts and chronic fatigue and depression.

  6. Thyroid neoplasia in Marshall Islanders exposed to nuclear fallout.

    PubMed

    Hamilton, T E; van Belle, G; LoGerfo, J P

    1987-08-01

    We studied the risk of thyroid neoplasia in Marshall Islanders exposed to radioiodines in nuclear fallout from the 1954 BRAVO thermonuclear test. We screened 7266 Marshall Islanders for thyroid nodules; the islanders were from 14 atolls, including several southern atolls, which were the source of the best available unexposed comparison group. Using a retrospective cohort design, we determined the prevalence of thyroid nodularity in a subgroup of 2273 persons who were alive in 1954 and who therefore were potentially exposed to fallout from the BRAVO test. For those 12 atolls previously thought to be unexposed to fallout, the prevalence of thyroid nodules ranged from 0.9% to 10.6%. Using the distance of each atoll from the test site as a proxy for the radiation dose to the thyroid gland, a weighted linear regression showed an inverse linear relationship between distance and the age-adjusted prevalence of thyroid nodules. Distance was the strongest single predictor in logistic regression analysis. A new absolute risk estimate was calculated to be 1100 excess cases/Gy/y/1 X 10(6) persons (11.0 excess cases/rad/y/1 million persons), 33% higher than previous estimates. We conclude that an excess of thyroid nodules was not limited only to the two northern atolls but extended throughout the northern atolls; this suggests a linear dose-response relationship.

  7. Lead excretion in milk of accidentally exposed dairy cattle.

    PubMed

    Bischoff, Karyn; Higgins, William; Thompson, Belinda; Ebel, Joseph G

    2014-01-01

    Lead (Pb) exposure in dairy cattle is associated with economic losses due to mortality and treatment costs, but with production animals there is also risk to the human food chain. The first objective of this study was to quantify the Pb concentration in milk from Pb-exposed cattle. The second objective was to correlate blood and milk Pb concentrations from individual cows. The third objective was long-term monitoring to determine the duration of milk contamination after exposure ceased. A dairy herd of more than 100 cows was accidentally exposed to Pb-contaminated feed. Milk and blood were collected for Pb analysis. Serial collection of milk samples continued for 2.5 years. The initial concentration of Pb in bulk tank milk was 0.0999 mg l⁻¹. The highest milk Pb concentration from an individual cow was 0.4657 mg l⁻¹ and the highest blood Pb concentration was 1.216 mg l⁻¹. One milk sample collected at the end of the study (day 922) contained 0.0117 mg Pb l⁻¹ of Pb. The calculated relationship between milk (y) and blood (x) Pb concentration was ln(y) = 3.4(x) - 2.21 (R² = 0.98).

  8. Evoked otoacoustic emissions in workers exposed to noise: A review

    PubMed Central

    Alcarás, Patrícia Arruda de Souza; Lüders, Débora; França, Denise Maria Vaz Romano; Klas, Regina Maria; Lacerda, Adriana Bender Moreira de; Gonçalves, Cláudia Giglio de Oliveira

    2012-01-01

    Summary Introduction: The otoacoustic emissions test is an essential tool in the evaluation of auditory function, since it allows the early detection of cochlear damage of occupational origin. Objective: To present a review of the literature and analyze the effectiveness of the clinical application of the otoacoustic emissions test in workers exposed to noise. Methods: A bibliographical search covering a period of 10 years was performed in the Virtual Health Library including published articles in national and international journals indexed in the internationally recognized databases for the health sciences, LILACS, SCIELO, and MEDLINE, using the terms “otoacoustic emissions” and “occupational exposure.” The type of published article (national/international), the type and intensity of the stimulus most commonly used for the evoked otoacoustic emissions, the gender and age of the subjects, and the conclusions from the retrospective studies were all taken into consideration. Results and Conclusions: A total of 19 articles were analyzed, 7 national and 12 international, covering subjects from 17 to 77 years of age, mostly men. The type of stimulus most commonly used for the evoked otoacoustic emissions was the distortion method (12). Through this review, we have concluded that testing of evoked otoacoustic emissions in workers exposed to noise is an important tool in the early diagnosis of noise-induced cochlear hearing disorders. PMID:25991982

  9. Error-Related Negativities During Spelling Judgments Expose Orthographic Knowledge

    PubMed Central

    Harris, Lindsay N.; Perfetti, Charles A.; Rickles, Benjamin

    2014-01-01

    In two experiments, we demonstrate that error-related negativities (ERNs) recorded during spelling decisions can expose individual differences in lexical knowledge. The first experiment found that the ERN was elicited during spelling decisions and that its magnitude was correlated with independent measures of subjects’ spelling knowledge. In the second experiment, we manipulated the phonology of misspelled stimuli and observed that ERN magnitudes were larger when misspelled words altered the phonology of their correctly spelled counterparts than when they preserved it. Thus, when an error is made in a decision about spelling, the brain processes indexed by the ERN reflect both phonological and orthographic input to the decision process. In both experiments, ERN effect sizes were correlated with assessments of lexical knowledge and reading, including offline spelling ability and spelling-mediated vocabulary knowledge. These results affirm the interdependent nature of orthographic, semantic, and phonological knowledge components while showing that spelling knowledge uniquely influences the ERN during spelling decisions. Finally, the study demonstrates the value of ERNs in exposing individual differences in lexical knowledge. PMID:24389506

  10. Methicillin Resistant Staphylococcus aureus Carriage, Antibiotic Resistance and Molecular Pathogenicity among Healthy Individuals Exposed and Not Exposed to Hospital Environment

    PubMed Central

    Krishnamurthy, Veena; Renushri, Bhadravati Virupaksha; Nagaraj, Elkal Rajappa

    2014-01-01

    Background: Healthcare workers as well as healthy community-dwelling individuals may be colonised by methicillin-resistant Staphylococcus aureus (MRSA). Healthcare workers who carry MRSA may transmit it to patients, causing various nosocomial infections. Literature shows that the differences between MRSA isolated from healthcare settings and from community settings, with regard to multi-drug resistance (traditionally exhibited by the former) and possession of pvl genes (traditionally exhibited by the latter), is diminishing due to a large community reservoir and increasing influx of community harboured strains into the hospital. However, there is no literature on the current scenario in India. Aims and Objectives: This study examines the influence of exposure to hospital environment on MRSA carriage, antimicrobial resistance patterns of MRSA, and the presence of genes encoding five extracellular pathogenicity determinants (pvl, sea, seb, tsst-1 and hly a). Materials and Methods: Nasal, throat and palmar swabs were collected from 119 nursing students of the age group 18-23 years (exposed group) and 100 age matched pharmacy students (non-exposed group). S. aureus was identified and antibiogram obtained as per Clinical and Laboratory Standards Institute (CLSI) guidelines. MRSA was detected by cefoxitin disc diffusion test and by growth on oxacillin screen agar as per CLSI guidelines. Conventional PCR was performed for mecA, pvl, sea, seb, tsst-1 and hly a. Results: The differences in carrier rates, antibiotic resistance patterns and expression of extracellular pathogenicity determinants between MRSA isolates from the two study groups were not significant, and pvl was found in all the MRSA isolates. Conclusion: The nursing students carried MRSA strains similar to those carried by the non-exposed group. Our results suggest that healthcare workers could act as a link and transmit MRSA acquired from the community to patients. PMID:25177563

  11. Genetic Analysis of Mice Skin Exposed by Hyper-Gravity

    NASA Astrophysics Data System (ADS)

    Takahashi, Rika; Terada, Masahiro; Seki, Masaya; Higashibata, Akira; Majima, Hideyuki J.; Ohira, Yoshinobu; Mukai, Chiaki; Ishioka, Noriaki

    2013-02-01

    In the space environment, physiological alterations, such as low bone density, muscle weakness and decreased immunity, are caused by microgravity and cosmic radiation. On the other hand, it is known that the leg muscles are hypertrophy by 2G-gravity. An understanding of the effects on human body from microgravity to hyper-gravity is very important. Recently, the Japan Aerospace Exploration Agency (JAXA) has started a project to detect the changes on gene expression and mineral metabolism caused by microgravity by analyzing the hair of astronauts who stay in the international Space Station (ISS) for a long time. From these results of human hair’s research, the genetic effects of human hair roots by microgravity will become clear. However, it is unclear how the gene expression of hair roots was effected by hypergravity. Therefore, in this experiment, we analyzed the effect on mice skin contained hair roots by comparing microgravity or hypergravity exposed mice. The purpose of this experiment is to evaluate the genetic effects on mice skin by microgravity or 2G-gravity. The samples were taken from mice exposed to space flight (FL) or hypergravity environment (2G) for 3-months, respectively. The extracted and amplified RNA from these mice skin was used to DNA microarray analysis. in this experiment, we analyzed the effect of gravity by using mice skin contained hair roots, which exposed space (FL) and hyper-gravity (2G) for 3 months and each control. By DNA microarray analysis, we found the common 98 genes changed in both FL and 2G. Among these 98 genes, the functions and pathways were identified by Gene Ontology (GO) analysis and Ingenuity Pathways Analysis (IPA) software. Next, we focused the one of the identified pathways and compared the effects on each molecules in this pathways by the different environments, such as FL and 2G. As the results, we could detect some interesting molecules, which might be depended on the gravity levels. In addition, to investigate

  12. Analysing deterioration of marble stones exposed to underwater conditions

    NASA Astrophysics Data System (ADS)

    Cámara, Beatriz; Álvarez de Buergo, Mónica; Bethencourt, Manuel; Freire-Lista, David; Fort, Rafael

    2016-04-01

    The peculiar conditions of the marine environment make the conservation of underwater archaeological sites an extremely complex procedure. This is due to the fact that the prevailing conditions in this environment promote the development of deterioration phenomena in submerged artefacts through the synergistic action of physical, chemical and biological factors. The objective of the present investigation was to determine how petrophysical properties of cultural heritage materials can be affected by being exposed to the specific underwater conditions of the sea bottom, and so, to evaluate how this can affect, in a long term, in their durability and evolution when they part of an archaeological site. For this purpose, two types of marble (the Italian Carrara and the Spanish Macael) were subjected to an experiment consisting of exposing stone materials for one and a half year to underwater conditions. The experimental test was located in an archaeological site in the Bay of Cadiz (southern Spain), Bajo del Chapitel (recognized as Cultural Interest), which includes remains of shipwrecks from different periods. In this site, samples were submerged to 12 m depth and placed in the sea bottom simulating the different positions in which underwater archaeological objects can be found (fully exposed, half buried and covered). Petrophysical characterisation involved determination of the apparent and bulk densities, water saturation (maximum water content a material may contain), open porosity (porosity accessible to water), chromatic parameters and ultrasonic velocity. Before measuring, samples were subjected to mechanical cleaning (in those samples with biological colonization) and to removal of salt deposits. Results showed significant differences in these petrophysical properties after underwater submersion, which were directly related to the type of underwater exposure condition. Comparative analysis of petrophysical properties, like the one conducted in this study

  13. Leavening ability of baker's yeast exposed to hyperosmotic media.

    PubMed

    Hirasawa, R; Yokoigawa, K

    2001-01-15

    To develop a simple and rapid method for enhancing the leavening ability of baker's yeast, we examined the fermentation ability of baker's yeast exposed to hyperosmotic media. When baker's yeast cells were incubated at 25 degrees C for 1 h in a hyperosmotic medium containing 0.5% yeast extract, 0.5% peptone and 20% sucrose, the cells showed a higher fermentation ability in the subsequent fermentation test than those untreated. The increased ratios were from 40 to 60% depending on the strains used. Glucose and fructose showed a similar effect to that of sucrose, but sorbitol was less effective. A high correlation between the intracellular glycerol content and fermentation ability after the osmotic treatment suggested that glycerol accumulated during the hyperosmotic treatment was used in the subsequent fermentation as a substrate, lessened the lag time, and consequently enhanced the fermentation ability. Various baker's yeasts also showed a high leavening ability in dough after the hyperosmotic treatment.

  14. Health effects among refrigeration repair workers exposed to fluorocarbons.

    PubMed Central

    Campbell, D D; Lockey, J E; Petajan, J; Gunter, B J; Rom, W N

    1986-01-01

    Refrigeration repair workers may be intermittently exposed to fluorocarbons and their thermal decomposition products. A case of peripheral neuropathy (distal axonopathy) in a commercial refrigeration repairman prompted an epidemiological investigation of the health of refrigeration repair workers. No additional cases of peripheral neuropathy were identified among the 27 refrigeration repair workers studied. A reference group of 14 non-refrigeration repair workers was also studied. No differences were noted between groups for the ulnar (motor and sensory), median (motor and sensory), peroneal, sural, or tibial nerve conduction velocities. Refrigeration repair workers reported palpitations and lightheadedness significantly more often than workers in the reference group. No clinical neurological or electroneurophysiological abnormalities were detected in eight refrigeration repair workers followed up for three years during continuous employment. PMID:3004555

  15. Reproductive adaptation in Drosophila exposed to oxygen-enriched atmospheres

    NASA Technical Reports Server (NTRS)

    Kloek, G.; Winkle, L.

    1979-01-01

    Ten successive generations of a Drosophila melanogaster population were exposed to an atmospheric mix of 50% oxygen/50% nitrogen at standard pressure. This atmospheric mix has been shown to be toxic to this species and causes significantly shortened life span. By the fifth generation, survivorship and life span for the first 25-30 days were identical to control populations and total life span was shorter by only a few days. Egg-laying rates were stable in the experimental populations but below those of the controls. Hatching success was identical between experimental and control populations. Even though the egg-laying rates were lower in 50% oxygen, it was concluded that the population had adapted and could maintain a stable population in these conditions. The near-normal life spans, normal hatching rates, and overall population stability, exhibited following five generations of adaptation, were considered sufficient to allow continued reproduction in spite of a reduced egg-laying rate.

  16. Lack of exposed ice inside lunar south pole Shackleton Crater.

    PubMed

    Haruyama, Junichi; Ohtake, Makiko; Matsunaga, Tsuneo; Morota, Tomokatsu; Honda, Chikatoshi; Yokota, Yasuhiro; Pieters, Carle M; Hara, Seiichi; Hioki, Kazuyuki; Saiki, Kazuto; Miyamoto, Hideaki; Iwasaki, Akira; Abe, Masanao; Ogawa, Yoshiko; Takeda, Hiroshi; Shirao, Motomaro; Yamaji, Atsushi; Josset, Jean-Luc

    2008-11-01

    The inside of Shackleton Crater at the lunar south pole is permanently shadowed; it has been inferred to hold water-ice deposits. The Terrain Camera (TC), a 10-meter-resolution stereo camera onboard the Selenological and Engineering Explorer (SELENE) spacecraft, succeeded in imaging the inside of the crater, which was faintly lit by sunlight scattered from the upper inner wall near the rim. The estimated temperature of the crater floor, based on the crater shape model derived from the TC data, is less than approximately 90 kelvin, cold enough to hold water-ice. However, at the TC's spatial resolution, the derived albedo indicates that exposed relatively pure water-ice deposits are not on the crater floor. Water-ice may be disseminated and mixed with soil over a small percentage of the area or may not exist at all.

  17. Developmental arrest in grass shrimp embryos exposed to selected toxicants

    SciTech Connect

    Wilson, J.E.H.

    1998-12-31

    Excised embryos of the grass shrimp (Palaemonetes pugio) were exposed to single pulse concentrations of selected pollutants for 4 days. The following toxicity endpoints were monitored: rate of embryonic development, embryo mortality, and types of embryo malformation. Each endpoint exhibited concentration--response relationships which were modified by the embryonic age at which exposure commenced. Developmental retardation of up to 3 days was effected by phenol at 0.01% (V/V) and complete developmental arrest occurred at 0.05% and 0.1% (V/V). Similarly for methylene chloride, developmental retardation of 1003 days were observed at 0.1% (V/V) depending on the age of the embryos at the start of the tests. The morphological abnormalities of the embryos are described. The ecological significance of these findings and implications for the development of short-term toxicity tests using grass shrimp embryos are discussed.

  18. DNA damage in Wistar rats exposed to dithiocarbamate pesticide mancozeb.

    PubMed

    Goldoni, A; Klauck, C R; Da Silva, S T; Da Silva, M D; Ardenghi, P G; Da Silva, L B

    2014-01-01

    Pesticides are used in large amounts in agriculture and the evaluation of their toxic effects is of major concern to public and environmental health. The aim of the present study was to investigate the genotoxic potential of a commercial formulation of the fungicide mancozeb by the micronucleus test in bone marrow and the comet assay in total blood of Wistar rats. Adult male Wistar rats were treated with a solution of mancozeb at a concentration of 40 mg/kg/day, administered intraperitoneally for 18 consecutive days, and compared to a control group. The results indicate that mancozeb induced significantly higher DNA damage as detected by the comet assay and increased the frequency of micronuclei. The results show that mancozeb is genotoxic and may adversely affect the DNA integrity of exposed organisms. PMID:25152054

  19. Eighteen cases exposed to sarin in Matsumoto, Japan.

    PubMed

    Suzuki, J; Kohno, T; Tsukagosi, M; Furuhata, T; Yamazaki, K

    1997-07-01

    Forty-six patients who were exposed to sarin consulted our hospital because of darkness of vision, and ocular pain, vomiting, dyspnea and headaches on June 27 and 28, 1994. Eighteen patients were admitted and 4 of them were in the critical state. There were 6 features: 1) depression of plasma cholinesterase activity (17 of 18 patients, 94%), 2) hypokalemia (4/18, 22%), 3) depression of triglyceride (12/18, 67%), 4) hypocapnia (5/17, 29%), 5) partial pressure of oxygen (PaO2) <80 mmHg, or requirement of O2 inhalation (15/18, 83%), 6) white blood cells (WBC) >9,000 per mm3 (13/18, 72%). Seventeen patients were discharged from hospital, but one patient is still suffering from akinetic mutism after two years.

  20. Morbidity and mortality in talc-exposed workers

    SciTech Connect

    Wergeland, E.; Andersen, A.; Baerheim, A. )

    1990-01-01

    Cancer incidence and cause-specific mortality were studied in a male cohort of 94 talc miners and 295 talc millers, exposed to non-asbestiform talc with low quartz content. No excess risk was found compared with national age-specific incidence. Six cases of lung cancer occurred versus 6.49 expected (miners: observed 2, expected 1.27; millers: observed 4, expected 5.22). There were 3 deaths due to non-malignant respiratory disease against 10.9 expected (miners: observed 1, expected 2.5; millers: observed 2, expected 8.4). Mesothelioma, tuberculosis, or pneumoconiosis were not recorded as causes of death. Pneumoconiosis was noted as a contributory cause in three cases (silicosis two, talcosis one). Further follow-up will reduce any potential impact of healthy worker selection.

  1. Neurobehavioral alterations in rats exposed to acrylonitrile in drinking water.

    PubMed

    Rongzhu, L; Suhua, W; Guangwei, X; Fangan, H; Ziqiang, C; Fusheng, J; Kacew, S

    2007-03-01

    This study was carried out on rodents, to explore the neurobehavioral effects of acrylonitrile (AN) administered in drinking water. Thirty, male, Sprague-Dawley rats were randomly divided into three groups: two exposure groups (50 and 200 ppm AN), and one control group (tap water without AN). Three tests, including the open field test, rotarod test and spatial water maze, were applied to evaluate locomotor activities, motor co-ordination and learning and memory, respectively, prior to initiation of the treatment, and at Week 4, 8 and 12 postexposure. There were no consistent changes in the open field test, except for locomotion and grooming episodes. In the rotarod test, AN significantly decreased the latencies to fall in a dose and time-dependent manner. In the spatial water maze test, rats exposed to AN for 12 weeks had significantly more training times and longer escape latencies than control animals. These findings indicate that oral exposure to AN induces neurobehavioral alterations in rats.

  2. Agent Orange: management of patients exposed in Vietnam.

    PubMed

    Beaulieu, Anne; Fessele, Kristen

    2003-01-01

    Since the Vietnam War ended in 1975, numerous studies have been conducted to determine if an association exists between Agent Orange exposure and certain disabling conditions specifically cancer. Although a definite causal relationship has not yet been established, sufficient data associate Agent Orange with certain conditions. Because of their advancing age similar to other baby boomers, Vietnam veterans are at a higher risk of developing malignancies. However, their exposure to Agent Orange also may increase their risk for cancer and other associated diseases. This article examines the latest findings of scientific research sponsored by the Department of Veterans Affairs and discusses the importance of well-informed oncology nurses when providing care for patients with cancer exposed to Agent Orange. PMID:12793339

  3. Third harmonic generation in exposed-core microstructured optical fibers.

    PubMed

    Warren-Smith, Stephen C; Wie, Jingxuan; Chemnitz, Mario; Kostecki, Roman; Ebendorff-Heidepriem, Heike; Monro, Tanya M; Schmidt, Markus A

    2016-08-01

    Inter-modal phase-matched third harmonic generation has been demonstrated in an exposed-core microstructured optical fiber. Our fiber, with a partially open core having a diameter of just 1.85 µm, shows efficient multi-peak third-harmonic generation between 500 nm and 530 nm, with a maximum visible-wavelength output of 0.96 μW. Mode images and simulations show strong agreement, confirming the phase-matching process and polarization dependence. We anticipate this work will lead to tailorable and tunable visible light sources by exploiting the open access to the optical fiber core, such as depositing thin-film coatings in order to shift the phase matching conditions. PMID:27505753

  4. Magical Empiricism and 'Exposed Being' in Medicine and Traditional Healing.

    PubMed

    Thornton, Robert

    2015-01-01

    Southern African traditional healers often generalize too broadly from discrete ('accidental') instances of success, partly to recruit a clientele, while biomedicine frequently reasons incorrectly from the general to the specific. Both logics are based on empirical observations, but are inversions of each other; these I characterize as 'magical empiricism.' 'Magic' functions as a metapragmatic discourse to recruit a clientele from a skeptical public that doubts the efficacy of any therapeutic interventions, and it acts in parallel with other practical (and efficacious) healing acts. I introduce the concept of 'exposed beings' to describe locally specific constructions of the person as patient and healer. This helps to explain the existence and enduring appeal of many different medical practices and beliefs in South Africa, but I suggest that 'medical parallelism' rather than 'pluralism' might be more accurate.

  5. Acute physiological responses of squirrel monkeys exposed to hyperdynamic environments

    NASA Technical Reports Server (NTRS)

    Fuller, C. A.

    1984-01-01

    Physiological and behavioral responses to a hyperdynamic environment were examined in four adult male squirrel monkeys. After baseline monitoring at 1 G, monkeys were exposed to one of three conditions: (1) +2 Gz for 60 minutes, (2) +2.9 Gz max for 8 minutes (simulating Space Shuttle launch), or (3) +1.7 Gz max for 19 minutes (simulating Space Shuttle reentry). During all experimental conditions, heart rate rose, and colonic temperature began to decline within the first ten minutes of centrifugation and decreased by as much as 2 C in some instances. Behaviorally, during centrifugation, the monkeys seemed to exhibit drowsiness and fall asleep, an observation not made during the control period. It is concluded that primates are susceptible to acute hyperdynamic field exposure.

  6. Wear of connector contacts exposed to relative motion

    NASA Astrophysics Data System (ADS)

    Wilk, R. A.

    Connectors play a significant role in the performance, cost, and reliability of electronic equipment. In connection with the development of the system interconnection design, a factor which is often overlooked is related to the importance of connector selection and mounting to minimize relative motion between contacts during vibration encountered in handling, transportation, and service. This motion can lead to the loss of protective coatings (gold and nickel) due to frictional wear. If this happens, fretting corrosion of the base metals may occur. The produced damage can adversely affect performance due to increased joint resistance, eventually causing intermittent contacts. The present investigation is concerned with the study of different style contacts (tuning fork, box, and circular) to determine their endurance and wear characteristics when exposed to relative motion created by vibration. All contacts investigated were fabricated from brass, beryllium copper, or phosphor bronze, and had .00127 mm minimum gold plating over .00127 mm minimum nickel plating.

  7. Magical Empiricism and 'Exposed Being' in Medicine and Traditional Healing.

    PubMed

    Thornton, Robert

    2015-01-01

    Southern African traditional healers often generalize too broadly from discrete ('accidental') instances of success, partly to recruit a clientele, while biomedicine frequently reasons incorrectly from the general to the specific. Both logics are based on empirical observations, but are inversions of each other; these I characterize as 'magical empiricism.' 'Magic' functions as a metapragmatic discourse to recruit a clientele from a skeptical public that doubts the efficacy of any therapeutic interventions, and it acts in parallel with other practical (and efficacious) healing acts. I introduce the concept of 'exposed beings' to describe locally specific constructions of the person as patient and healer. This helps to explain the existence and enduring appeal of many different medical practices and beliefs in South Africa, but I suggest that 'medical parallelism' rather than 'pluralism' might be more accurate. PMID:25806659

  8. Support for Students Exposed to Trauma: A Pilot Study

    PubMed Central

    Jaycox, Lisa H.; Langley, Audra K.; Stein, Bradley D.; Wong, Marleen; Sharma, Priya; Scott, Molly; Schonlau, Matthias

    2010-01-01

    With high rates of trauma exposure among students, the need for intervention programs is clear. Delivery of such programs in the school setting eliminates key barriers to access, but there are few programs that demonstrate efficacy in this setting. Programs to date have been designed for delivery by clinicians, who are a scarce resource in many schools. This study describes preliminary feasibility and acceptability data from a pilot study of a new program, Support for Students Exposed to Trauma, adapted from the Cognitive Behavioral Intervention for Trauma in Schools (CBITS) program. Because of its “pilot” nature, all results from the study should be viewed as preliminary. Results show that the program can be implemented successfully by teachers and school counselors, with good satisfaction among students and parents. Pilot data show small reductions in symptoms among the students in the SSET program, suggesting that this program shows promise that warrants a full evaluation of effectiveness. PMID:20811511

  9. Toxicokinetics of captan and folpet biomarkers in dermally exposed volunteers.

    PubMed

    Berthet, Aurélie; Bouchard, Michèle; Vernez, David

    2012-03-01

    To better assess biomonitoring data in workers exposed to captan and folpet, the kinetics of ring metabolites [tetrahydrophthalimide (THPI), phthalimide (PI) and phthalic acid] were determined in urine and plasma of dermally exposed volunteers. A 10  mg kg(-1) dose of each fungicide was applied on 80  cm(2) of the forearm and left without occlusion or washing for 24  h. Blood samples were withdrawn at fixed time periods over the 72  h following application and complete urine voids were collected over 96  h post-dosing, for metabolite analysis. In the hours following treatment, a progressive increase in plasma levels of THPI and PI was observed, with peak levels being reached at 24  h for THPI and 10  h for PI. The ensuing elimination phase appeared monophasic with a mean elimination half-life (t(½) ) of 24.7 and 29.7 h for THPI and PI, respectively. In urine, time courses PI and phthalic acid excretion rate rapidly evolved in parallel, and a mean elimination t(½) of 28.8 and 29.6  h, respectively, was calculated from these curves. THPI was eliminated slightly faster, with a mean t(½) of 18.7  h. Over the 96  h period post-application, metabolites were almost completely excreted, and on average 0.02% of captan dose was recovered in urine as THPI while 1.8% of the folpet dose was excreted as phthalic acid and 0.002% as PI, suggesting a low dermal absorption fraction for both fungicides. This study showed the potential use of THPI, PI and phthalic acid as key biomarkers of exposure to captan and folpet.

  10. Viability and Virulence of Entomopathogenic Nematodes Exposed to Ultraviolet Radiation.

    PubMed

    Shapiro-Ilan, David I; Hazir, Selcuk; Lete, Luis

    2015-09-01

    Entomopathogenic nematodes (EPNs) can be highly effective biocontrol agents, but their efficacy can be reduced due to exposure to environmental stress such as from ultraviolet (UV) radiation. Our objectives were to 1) compare UV tolerance among a broad array of EPN species, and 2) investigate the relationship between reduced nematode viability (after exposure to UV) and virulence. Nematodes exposed to a UV radiation (254 nm) for 10 or 20 min were assessed separately for viability (survival) and virulence to Galleria mellonella. We compared 9 different EPN species and 15 strains: Heterorhabditis bacteriophora (Baine, fl11, Oswego, and Vs strains), H. floridensis (332), H. georgiana (Kesha), H. indica (HOM1), H. megidis (UK211), Steinernema carpocapsae (All, Cxrd, DD136, and Sal strains), S. feltiae (SN), S. rarum (17C&E), and S. riobrave (355). In viability assessments, steinernematids, particularly strains of S. carpocapsae, generally exhibited superior UV tolerance compared with the heterorhabditids. However, some heterorhabditids tended to be more tolerant than others, e.g., H. megidis and H. bacteriophora (Baine) were most susceptible and H. bacteriophora (Vs) was the only heterorhabditid that did not exhibit a significant effect after 10 min of exposure. All heterorhabditids experienced reduced viability after 20 min exposure though several S. carpocapsae strains did not. In total, after 10 or 20 min exposure, the viability of seven nematode strains did not differ from their non-UV exposed controls. In virulence assays, steinernematids (particularly S. carpocapsae strains) also tended to exhibit higher UV tolerance. However, in contrast to the viability measurements, all nematodes experienced a reduction in virulence relative to their controls. Correlation analysis revealed that viability among nematode strains is not necessarily related to virulence. In conclusion, our results indicate that the impact of UV varies substantially among EPNs, and viability alone

  11. Acute and delayed thermoregulatory response of mice exposed to brevetoxin.

    PubMed

    Gordon, C J; Kimm-Brinson, K L; Padnos, B; Ramsdell, J S

    2001-09-01

    Thermal dysthesia, characterized by a painful sensation of warm and cool surfaces, is one of many ailments in humans exposed to various marine algal toxins such as brevetoxin (PbTx). There is no animal model to study thermal dysthesia and little is known of the mechanism of action. There is also little known on the acute and delayed thermoregulatory effects of PbTx. In this study, we developed a behavioral system to assess the possible development of thermal dysthesia in mice exposed to PbTx. Female mice were implanted with radiotransmitters to monitor core temperature (Tc) and motor activity (MA). In one experiment, mice were dosed with the control vehicle or 180 microg/kg PbTx and placed on a floor temperature gradient to measure the selected foot temperature (SFT) while air temperature was kept constant. PbTx-treated mice underwent a 10 degrees C reduction in SFT concomitant with a 3 degrees C reduction in Tc within 30 min after exposure. In another study, Tc and MA were monitored in mice maintained in their home cages after dosing with 180 microg/kg PbTx. Tc but not MA increased for 2-5 days after exposure. SFT was unaffected by PbTx when tested 1-12 days after exposure. However, PbTx-treated mice underwent an increase in Tc when placed in the temperature gradient for up to 12 days after exposure. This suggests that PbTx augments the stress-induced hyperthermia from being placed in a novel environment. Overall, acute PbTx exposure leads to a regulated reduction in Tc as characterized by a preference for cooler SFTs and a reduced Tc. Thermal dysthesia was not apparent, but the exaggerated hyperthermic response with a normal SFT in the temperature gradient may suggest an altered processing of thermal stimuli in mice treated with PbTx.

  12. Neurobehavioral changes in mice exposed to fast neutrons in utero.

    PubMed

    Ishida, Yuka; Ohmachi, Yasushi; Takai, Nobuhiko; Hiraoka, Takeshi; Ogiu, Toshiaki; Nishikawa, Tetsu; Nishimura, Yoshikazu; Shimada, Yoshiya

    2011-01-01

    Epidemiological studies have revealed that radiation causes brain development abnormalities in atomic bomb survivors exposed in utero. Rat and mouse studies have also shown that prenatal exposure to low-linear energy transfer radiation induces developmental brain anomalies. Because the effects of prenatal irradiation on adult behavior patterns remain largely unknown, the present study investigated the effects of neutron exposure in utero on postnatal behavior patterns in mice. [C57BL/6J × C3H/He] hybrid (B6C3F1) mice were exposed to cyclotron-derived fast neutrons with peak energy of 10 MeV (0.02-0.2 Gy) or Cs-137 gamma-rays (0.2-1.5 Gy) on embryonic day 13.5. At 5.5-8 months of age, the neurobehavior of male offspring was examined by Rota-rod treadmill and locomotor activity. The accumulation of radio-labeled drug at muscarinic acetylcholine and serotonin receptors in mice from control and neutron-irradiated groups was determined by the tracer method. Locomotor activity during the dark period increased in the 0.02 Gy neutron-irradiated group. Furthermore, at 5.5 months of age, tracer binding in vivo to the muscarinic acetylcholine increased and to the serotonin receptors decreased in the 0.02 Gy neutron-irradiated group. In conclusion, the present study reveals that a certain "low-dose window" may exist for radiation-induced changes in neurobehavior and binding to neurotransmitter receptors, because there was correlation in neurobehavior and binding to neurotransmitter receptors in the 0.02 Gy neutron-irradiated group though there was not correlation in the neutron-irradiated groups more than 0.05 Gy. PMID:21422737

  13. Mechanisms of damage to corals exposed to sedimentation.

    PubMed

    Weber, Miriam; de Beer, Dirk; Lott, Christian; Polerecky, Lubos; Kohls, Katharina; Abed, Raeid M M; Ferdelman, Timothy G; Fabricius, Katharina E

    2012-06-12

    We investigated the mechanisms leading to rapid death of corals when exposed to runoff and resuspended sediments, postulating that the killing was microbially mediated. Microsensor measurements were conducted in mesocosm experiments and in naturally accumulated sediment on corals. In organic-rich, but not in organic-poor sediment, pH and oxygen started to decrease as soon as the sediment accumulated on the coral. Organic-rich sediments caused tissue degradation within 1 d, whereas organic-poor sediments had no effect after 6 d. In the harmful organic-rich sediment, hydrogen sulfide concentrations were low initially but increased progressively because of the degradation of coral mucus and dead tissue. Dark incubations of corals showed that separate exposures to darkness, anoxia, and low pH did not cause mortality within 4 d. However, the combination of anoxia and low pH led to colony death within 24 h. When hydrogen sulfide was added after 12 h of anoxia and low pH, colonies died after an additional 3 h. We suggest that sedimentation kills corals through microbial processes triggered by the organic matter in the sediments, namely respiration and presumably fermentation and desulfurylation of products from tissue degradation. First, increased microbial respiration results in reduced O(2) and pH, initiating tissue degradation. Subsequently, the hydrogen sulfide formed by bacterial decomposition of coral tissue and mucus diffuses to the neighboring tissues, accelerating the spread of colony mortality. Our data suggest that the organic enrichment of coastal sediments is a key process in the degradation of coral reefs exposed to terrestrial runoff.

  14. Neurobehavioral changes in mice exposed to fast neutrons in utero.

    PubMed

    Ishida, Yuka; Ohmachi, Yasushi; Takai, Nobuhiko; Hiraoka, Takeshi; Ogiu, Toshiaki; Nishikawa, Tetsu; Nishimura, Yoshikazu; Shimada, Yoshiya

    2011-01-01

    Epidemiological studies have revealed that radiation causes brain development abnormalities in atomic bomb survivors exposed in utero. Rat and mouse studies have also shown that prenatal exposure to low-linear energy transfer radiation induces developmental brain anomalies. Because the effects of prenatal irradiation on adult behavior patterns remain largely unknown, the present study investigated the effects of neutron exposure in utero on postnatal behavior patterns in mice. [C57BL/6J × C3H/He] hybrid (B6C3F1) mice were exposed to cyclotron-derived fast neutrons with peak energy of 10 MeV (0.02-0.2 Gy) or Cs-137 gamma-rays (0.2-1.5 Gy) on embryonic day 13.5. At 5.5-8 months of age, the neurobehavior of male offspring was examined by Rota-rod treadmill and locomotor activity. The accumulation of radio-labeled drug at muscarinic acetylcholine and serotonin receptors in mice from control and neutron-irradiated groups was determined by the tracer method. Locomotor activity during the dark period increased in the 0.02 Gy neutron-irradiated group. Furthermore, at 5.5 months of age, tracer binding in vivo to the muscarinic acetylcholine increased and to the serotonin receptors decreased in the 0.02 Gy neutron-irradiated group. In conclusion, the present study reveals that a certain "low-dose window" may exist for radiation-induced changes in neurobehavior and binding to neurotransmitter receptors, because there was correlation in neurobehavior and binding to neurotransmitter receptors in the 0.02 Gy neutron-irradiated group though there was not correlation in the neutron-irradiated groups more than 0.05 Gy.

  15. Hydrogen absorption in iron exposed to simulated concrete pore solutions

    SciTech Connect

    Lillard, R.S.; Scully, J.R.

    1996-02-01

    Safe cathodic protection (CP) limits are required for prestressed steel in concrete to avoid the risk of hydrogen embrittlement (HE). This preliminary study addressed some effects of concrete pore solution chemistry and metal surface condition on hydrogen absorption in iron. To accomplish this, the Devanathan-Stachurski permeation technique was used to investigate hydrogen absorption in 99.5% iron foils exposed to NaOH, saturated Ca(OH){sub 2}, and saturated Ca(OH){sub 2} + 0.6 M NaCl, all at pH 12.5. The foils used in this investigation were tested after various surface preparations: (a) polished, (b) with a thermal oxide formed by a heat treatment designed to simulate the stress relief oxide, and (c) with corrosion films to simulate an inservice tendon that was exposed to a marine environment for some time prior to CP. Hydrogen uptake in iron was most efficient for foils covered with Portland cement-based mortar, at least 2.5 times greater than that in NaOH of the same pH and hydrogen production rate. Absorption in saturated Ca(OH){sub 2} was somewhat less than that from the mortar cover. While chloride had no direct effect on the hydrogen absorption rate, the corrosion product and the thermal oxide were found to decrease hydrogen absorption compared to polished iron. The thermal oxide acted as a complete barrier at all charging current densities investigated. The effectiveness of this thermal oxide barrier to hydrogen, however, was compromised by corrosion resulting from alternate immersion exposure to a chloride environment.

  16. Water relations of differentially irrigated cotton exposed to ozone

    SciTech Connect

    Temple, P.J.

    1990-01-01

    The field study was conducted to test the hypothesis that plants chronically exposed to O{sub 3} may be more susceptible to drought because O{sub 3} typically inhibits root growth and increases shoot-root ratios in plants. Cotton was grown in open-top chambers on Hanford coarse sandy loam in Riverside, CA. Plants were grown under three irrigation regimes: Optimum water for lint production (OW), suboptimum or moderate drought stress (SO), and severely drought stressed (SS) and were exposed to seasonal 12 h (0800-2000) O{sub 3} centrations of 0.015, 0.074, 0.094, or 0.111/microLL. Leaf xylem pressure potentials Psi(sub 1) and soil water content Theta(sub v) were measured weekly from June to October. Mean seasonal Psi(sub 1) increased from -1.89 MPa to -1.72 MPa in low to high O{sub 3} treatments, averaged across soil water regimes. Ozone had no effect on seasonal water use of cotton, but water use efficiency was significantly reduced by O{sub 3} in OW and SO, but not in SS treatments. Drought-stressed plants extracted proportionally greater amounts of water from deeper in the soil profile than OW cotton, and O{sub 3} had no apparent effect on this redistribution of roots in the soil. Since O{sub 3} had no apparent effect on the ability of drought-stressed cotton to maintain Psi(sub 1) and to increase root growth relative to shoot growth, this suggests that O{sub 3} may have little or no effect on the potential of cotton to adapt to or tolerate drought.

  17. Acute and delayed thermoregulatory response of mice exposed to brevetoxin.

    PubMed

    Gordon, C J; Kimm-Brinson, K L; Padnos, B; Ramsdell, J S

    2001-09-01

    Thermal dysthesia, characterized by a painful sensation of warm and cool surfaces, is one of many ailments in humans exposed to various marine algal toxins such as brevetoxin (PbTx). There is no animal model to study thermal dysthesia and little is known of the mechanism of action. There is also little known on the acute and delayed thermoregulatory effects of PbTx. In this study, we developed a behavioral system to assess the possible development of thermal dysthesia in mice exposed to PbTx. Female mice were implanted with radiotransmitters to monitor core temperature (Tc) and motor activity (MA). In one experiment, mice were dosed with the control vehicle or 180 microg/kg PbTx and placed on a floor temperature gradient to measure the selected foot temperature (SFT) while air temperature was kept constant. PbTx-treated mice underwent a 10 degrees C reduction in SFT concomitant with a 3 degrees C reduction in Tc within 30 min after exposure. In another study, Tc and MA were monitored in mice maintained in their home cages after dosing with 180 microg/kg PbTx. Tc but not MA increased for 2-5 days after exposure. SFT was unaffected by PbTx when tested 1-12 days after exposure. However, PbTx-treated mice underwent an increase in Tc when placed in the temperature gradient for up to 12 days after exposure. This suggests that PbTx augments the stress-induced hyperthermia from being placed in a novel environment. Overall, acute PbTx exposure leads to a regulated reduction in Tc as characterized by a preference for cooler SFTs and a reduced Tc. Thermal dysthesia was not apparent, but the exaggerated hyperthermic response with a normal SFT in the temperature gradient may suggest an altered processing of thermal stimuli in mice treated with PbTx. PMID:11384725

  18. Deciphering Genome Environment Wide Interactions Using Exposed Subjects Only.

    PubMed

    Zhao, Lue Ping; Fan, Wenhong; Goodman, Gary; Radich, Jerry; Martin, Paul

    2015-07-01

    The recent successes of genome-wide association studies (GWAS) have renewed interest in genome environment wide interaction studies (GEWIS) to discover genetic factors that modulate penetrance of environmental exposures to human diseases. Indeed, gene-environment interactions (G × E), which have not been emphasized in the GWAS era, could be a source contributing to the missing heritability, a major bottleneck limiting continuing GWAS successes. In this manuscript, we describe a design and analytic strategy to focus on G × E using only exposed subjects, dubbed as e-GEWIS. Operationally, an e-GEWIS analysis is equivalent to a GWAS analysis on exposed subjects only, and it has actually been used in some earlier GWAS without being explicitly identified as such. Through both analytics and simulations, e-GEWIS has been shown better efficiency than the usual cross-product-based analysis of G × E interaction with both cases and controls (cc-GEWIS), and they have comparable efficiency to case-only analysis of G × E (c-GEWIS), with potentially smaller sample sizes. The formalization of e-GEWIS here provides a theoretical basis to legitimize this framework for routine investigation of G × E, for more efficient G × E study designs, and for improvement of reproducibility in replicating GEWIS findings. As an illustration, we apply e-GEWIS to a lung cancer GWAS data set to perform a GEWIS, focusing on gene and smoking interaction. The e-GEWIS analysis successfully uncovered positive genetic associations on chromosome 15 among current smokers, suggesting a gene-smoking interaction. Although this signal was detected earlier, the current finding here serves as a positive control in support of this e-GEWIS strategy.

  19. Dry heat exposures of surface exposed and embedded Bacillus spores

    NASA Astrophysics Data System (ADS)

    Schubert, Wayne

    Dry heat microbial reduction (DHMR) is the primary technique used to reduce the microbial load of spacecraft and component parts. Often, manufacturing procedures require heating flight hardware to high temperatures for purposes other than planetary protection DHMR. The existing specifications, however, do not allow for additional planetary protection bioburden reduction credit if the hardware is exposed without controlled relative humidity. The intent of this study was to provide adequate data on the DHMR technique to support modification of four aspects of current requirements; expansion of acceptable time and temperature combinations used for spacecraft dry heat microbial reduction processes above 125° C, determining the effect that humidity has on spore lethality as a function of temperature, understanding the lethality for spores with exceptionally high thermal resistance and to investigate the extended exposure requirement for materials that might contain embedded microorganisms. Spores from two bacterial species were tested, B. atrophaeus ATCC 9372 and B. sp. ATCC 29669, under three conditions encompassing 5 temperature points. Embedded experiments utilized a silicone rubber polymer that is commonly used on robotic spacecraft, and surface exposed experiments were performed under both ambient and vacuum-controlled humidity conditions. The results obtained support the use of DHMR protocols that extend the maximum temperature range from 125° C to 170° C, with either controlled or ambient humidity. If implemented, this will give projects bioburden reduction credit for shorter treatments at extended temperatures, and allow spacecraft to be processed in more readily available and less expensive facilities that do not have humidity control, with significant cost and schedule benefits. The study also demonstrated that the required heating time for materials presumed to have embedded bioburden is conservative.

  20. Deciphering Genome-Environment-Wide Interactions Using Exposed Subjects Only

    PubMed Central

    Zhao, Lue Ping; Fan, Wenhong; Goodman, Gary; Radich, Jerry; Martin, Paul

    2015-01-01

    The recent successes of genome-wide association studies (GWAS) have renewed interest in genome-environment-wide interaction studies (GEWIS) to discover genetic factors that modulate penetrance of environmental exposures to human diseases. Indeed, gene-environment interactions (GxE), which have not been emphasized in the GWAS era, could be a source contributing to the missing heritability, a major bottleneck limiting continuing GWAS successes. In this manuscript, we describe a design and analytic strategy to focus on GxE using only exposed subjects, dubbed as e-GEWIS. Operationally, an e-GEWIS analysis is equivalent to a GWAS analysis on exposed subjects only, and it has actually been used in some earlier GWAS without being explicitly identified as such. Through both analytics and simulations, e-GEWIS have been shown better efficiency than the usual cross-product-based analysis of GxE interaction with both cases and controls (cc-GEWIS), and they have comparable efficiency to case-only analysis of GxE (c-GEWIS), with potentially smaller sample sizes. The formalization of e-GEWIS here provides a theoretical basis to legitimize this framework for routine investigation of GxE, for more efficient GxE study designs, and for improvement of reproducibility in replicating GEWIS findings. As an illustration, we apply e-GEWIS to a lung cancer GWAS dataset to perform a GEWIS, focusing on gene and smoking interaction. The e-GEWIS analysis successfully uncovered positive genetic associations on chromosome 15 among current smokers, suggesting a gene-smoking interaction. While this signal was detected earlier, the current finding here serves as a positive control in support of this e-GEWIS strategy. PMID:25694100

  1. Chromosome aberrations in human blood lymphocytes exposed to energetic protons

    NASA Astrophysics Data System (ADS)

    Hada, Megumi; George, Ms Kerry; Cucinotta, Francis A.

    During space flight, astronauts are exposed to space radiation consisting of high-energy protons, high charge and energy (HZE) nuclei, as well as secondary particles that are generated when the primary particles penetrate the spacecraft shielding. Secondary particles have a higher LET value than primary protons and are therefore expected to have a higher relative biological effectiveness (RBE). To investigate this theory, we exposed human peripheral blood lymphocytes to protons with energies of 250 MeV, 800MeV, 2 GeV, or 2.5 GeV. LET values for these protons ranged from 0.4 to 0.2 keV/µm. and doses ranged from 0.2 to 3 Gy. Over this energy range the probability of nuclear reaction leading to secondary radiation, and the multiplicity of reaction products such as neutrons and mesons increases substantially. The effect of aluminum and polyethylene shielding was also assessed using the 2 GeV and 2.5GeV proton beams. After exposure lymphocytes were stimulated to divide and chromosomes were collected from cells in the first G2 and metaphase cell cycle after exposure using a chemical induced premature chromosome condensation (PCC) technique. Dose response data for chromosome damage was analyzed using the fluorescence in situ hybridization (FISH) chromosome painting technique. Selected samples were also analyzed with multicolor FISH (mFISH) and multicolor banding FISH (mBAND) techniques. Data indicates that the dose response for simple-type exchanges is similar for proton and gamma exposure, whereas protons induce higher yields of complex exchanges that are energy dependent. RBE values will be presented for each proton energy, and the effects of shielding and possible cytogenetic signatures of proton exposure will be discussed.

  2. Chromosome Aberration in Human Blood Lymphocytes Exposed to Energetic Protons

    NASA Technical Reports Server (NTRS)

    Hada, M.; George, Kerry A.; Cucinotta, F. A.

    2008-01-01

    During space flight, astronauts are exposed to a space radiation consisting of high-energy protons, high charge and energy (HZE) nuclei, as well as secondary particles that are generated when the primary particles penetrate the spacecraft shielding. Secondary particles have a higher LET value than primary protons and therefore expected to have a higher relative biological effectiveness (RBE). To investigate this theory, we exposed human peripheral blood lymphocytes to protons with energies of 250 MeV, 800MeV, 2 GeV, or 2.5 GeV. LET values for these protons ranged from 0.4 to 0.2 keV/micrometer. and doses ranged from 0.2 to 3 Gy. Over this energy the probability of nuclear reaction leading to secondary radiation, and the multiplicity of reaction produces such as neutrons and mesons increases substantially. The effect of aluminum and polyethylene shielding was also assessed using the 2 GeV and 2.5GeV proton beams. After exposure lymphocytes were stimulated to divide and chromosomes were collected from cells in the first G2 and metaphase cell cycle after exposure using a chemical induced premature chromosome condensation (PCC) technique. Dose response data for chromosome damage was analyzed using the fluorescence in situ hybridization (FISH) chromosome painting technique. Selected samples were also analyzed with multicolor FISH (mFISH) and multicolor banding FISH (mBAND) techniques. Data indicates that the dose response for simple-type exchanges is similar for proton and gamma exposure, whereas protons induce higher yields of complex exchanges that are LET dependent. RBE values will be presented for each proton energy, and the effects of shielding and possible cytogenetic signatures of proton exposure will be discussed.

  3. 42 CFR 84.86 - Component parts exposed to oxygen pressures; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... component parts exposed to oxygen pressures above atmospheric pressure are safe and compatible for their... 42 Public Health 1 2010-10-01 2010-10-01 false Component parts exposed to oxygen pressures... PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.86 Component parts exposed to oxygen...

  4. 9 CFR 73.8 - Cattle infected or exposed during transit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cattle infected or exposed during... SCABIES IN CATTLE § 73.8 Cattle infected or exposed during transit. (a) Healthy cattle from unquarantined State exposed en route. Should healthy cattle in transit from a State not quarantined by the...

  5. 9 CFR 73.8 - Cattle infected or exposed during transit.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Cattle infected or exposed during... SCABIES IN CATTLE § 73.8 Cattle infected or exposed during transit. (a) Healthy cattle from unquarantined State exposed en route. Should healthy cattle in transit from a State not quarantined by the...

  6. 9 CFR 73.8 - Cattle infected or exposed during transit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Cattle infected or exposed during... SCABIES IN CATTLE § 73.8 Cattle infected or exposed during transit. (a) Healthy cattle from unquarantined State exposed en route. Should healthy cattle in transit from a State not quarantined by the...

  7. 9 CFR 73.8 - Cattle infected or exposed during transit.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Cattle infected or exposed during... SCABIES IN CATTLE § 73.8 Cattle infected or exposed during transit. (a) Healthy cattle from unquarantined State exposed en route. Should healthy cattle in transit from a State not quarantined by the...

  8. 9 CFR 73.8 - Cattle infected or exposed during transit.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Cattle infected or exposed during... SCABIES IN CATTLE § 73.8 Cattle infected or exposed during transit. (a) Healthy cattle from unquarantined State exposed en route. Should healthy cattle in transit from a State not quarantined by the...

  9. 42 CFR 84.86 - Component parts exposed to oxygen pressures; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... component parts exposed to oxygen pressures above atmospheric pressure are safe and compatible for their... 42 Public Health 1 2014-10-01 2014-10-01 false Component parts exposed to oxygen pressures... PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.86 Component parts exposed to oxygen...

  10. 42 CFR 84.86 - Component parts exposed to oxygen pressures; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... component parts exposed to oxygen pressures above atmospheric pressure are safe and compatible for their... 42 Public Health 1 2011-10-01 2011-10-01 false Component parts exposed to oxygen pressures... PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.86 Component parts exposed to oxygen...

  11. 42 CFR 84.86 - Component parts exposed to oxygen pressures; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... component parts exposed to oxygen pressures above atmospheric pressure are safe and compatible for their... 42 Public Health 1 2012-10-01 2012-10-01 false Component parts exposed to oxygen pressures... PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.86 Component parts exposed to oxygen...

  12. 42 CFR 84.86 - Component parts exposed to oxygen pressures; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... component parts exposed to oxygen pressures above atmospheric pressure are safe and compatible for their... 42 Public Health 1 2013-10-01 2013-10-01 false Component parts exposed to oxygen pressures... PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.86 Component parts exposed to oxygen...

  13. 30 CFR 77.508 - Lightning arresters, ungrounded and exposed power conductors and telephone wires.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Lightning arresters, ungrounded and exposed... arresters, ungrounded and exposed power conductors and telephone wires. All ungrounded, exposed power conductors and telephone wires shall be equipped with suitable lightning arresters which are...

  14. Mutagenesis in bacterial spores exposed to space and simulated martian conditions: data from the EXPOSE-E spaceflight experiment PROTECT.

    PubMed

    Moeller, Ralf; Reitz, Günther; Nicholson The Protect Team, Wayne L; Horneck, Gerda

    2012-05-01

    As part of the PROTECT experiment of the EXPOSE-E mission on board the International Space Station (ISS), the mutagenic efficiency of space was studied in spores of Bacillus subtilis 168. After 1.5 years' exposure to selected parameters of outer space or simulated martian conditions, the rates of induced mutations to rifampicin resistance (Rif(R)) and sporulation deficiency (Spo(-)) were quantified. In all flight samples, both mutations, Rif(R) and Spo(-), were induced and their rates increased by several orders of magnitude. Extraterrestrial solar UV radiation (>110 nm) as well as simulated martian UV radiation (>200 nm) led to the most pronounced increase (up to nearly 4 orders of magnitude); however, mutations were also induced in flight samples shielded from insolation, which were exposed to the same conditions except solar irradiation. Nucleotide sequencing located the Rif(R) mutations in the rpoB gene encoding the β-subunit of RNA polymerase. Mutations isolated from flight and parallel mission ground reference (MGR) samples were exclusively localized to Cluster I. The 21 Rif(R) mutations isolated from the flight experiment showed all a C to T transition and were all localized to one hotspot: H482Y. In mutants isolated from the MGR, the spectrum was wider with predicted amino acid changes at residues Q469K/L/R, H482D/P/R/Y, and S487L. The data show the unique mutagenic power of space and martian surface conditions as a consequence of DNA injuries induced by solar UV radiation and space vacuum or the low pressure of Mars.

  15. Mutagenesis in bacterial spores exposed to space and simulated martian conditions: data from the EXPOSE-E spaceflight experiment PROTECT.

    PubMed

    Moeller, Ralf; Reitz, Günther; Nicholson The Protect Team, Wayne L; Horneck, Gerda

    2012-05-01

    As part of the PROTECT experiment of the EXPOSE-E mission on board the International Space Station (ISS), the mutagenic efficiency of space was studied in spores of Bacillus subtilis 168. After 1.5 years' exposure to selected parameters of outer space or simulated martian conditions, the rates of induced mutations to rifampicin resistance (Rif(R)) and sporulation deficiency (Spo(-)) were quantified. In all flight samples, both mutations, Rif(R) and Spo(-), were induced and their rates increased by several orders of magnitude. Extraterrestrial solar UV radiation (>110 nm) as well as simulated martian UV radiation (>200 nm) led to the most pronounced increase (up to nearly 4 orders of magnitude); however, mutations were also induced in flight samples shielded from insolation, which were exposed to the same conditions except solar irradiation. Nucleotide sequencing located the Rif(R) mutations in the rpoB gene encoding the β-subunit of RNA polymerase. Mutations isolated from flight and parallel mission ground reference (MGR) samples were exclusively localized to Cluster I. The 21 Rif(R) mutations isolated from the flight experiment showed all a C to T transition and were all localized to one hotspot: H482Y. In mutants isolated from the MGR, the spectrum was wider with predicted amino acid changes at residues Q469K/L/R, H482D/P/R/Y, and S487L. The data show the unique mutagenic power of space and martian surface conditions as a consequence of DNA injuries induced by solar UV radiation and space vacuum or the low pressure of Mars. PMID:22680692

  16. Loi constitutive chimioplastique pour le beton expose aux hautes temperatures

    NASA Astrophysics Data System (ADS)

    Hammoud, Rabah

    Concrete is the most widely used construction material in the world. Even though it has been used for several centuries, its behavior to high temperature remains to be understood. In the light of recent extreme events, including accidents, and arson, special attention has been focused on the performance of concrete in the fire safety assessment of buildings and tunnels. Fire represents one of the most severe conditions encountered during the life-time of a structure. Concrete exposed to high temperature can significantly jeopardize the structural integrity and load bearing capacity of the structure. Spalling of concrete remains one of the main issues to be addressed in the case of fire in buildings and tunnels. Successful modeling of this phenomenon depends not only on the accurate prediction of the temperature distribution through structural concrete but also on its mechanical response to the heating and boundaries restrains conditions and the migration of moisture and associated pore pressures. Therefore, it is necessary to develop a reliable formulation of concrete with all required information to understand its behavior during and after exposure to elevated temperature. It is also necessary to properly assess the effects of thermal degradation in order to develop predictive tools and validate design codes. Many structural problems can be adequately worthy by an elastoplastic model. The ultimate goal of this study is the development of a new constitutive model under a chemoplastic framework. To do this, an experimental program is carried out. The purpose of this program is twofold. First, it is essential to calibrate the proposed constitutive law that will be developed, and, second, for defining an inverse a problem. Usually, uniaxial and triaxial tests, conducted with confining pressure varied between 1.3 and 24 MPa and a temperature up to 700°C, allow us to identify the constitutive law parameters. This law reproduces the reduced field strength due to

  17. Frequency of marriage and live birth among survivors prenatally exposed to the atomic bomb.

    PubMed

    Blot, W J; Shimizu, Y; Kato, H; Miller, R W

    1975-08-01

    Frequency of marriage and birth as of January 1973 was determined for persons exposed in utero to the atomic bombs in 1945 and for controls. The marriage rate was lower in persons heavily exposed in utero than in the non-exposed or lightly exposed. This difference is attributed partly to the lesser marriageability of persons with mental retardation who are significantly more numerous among the heavily exposed, and partly to unmeasured variables, possibly including social discrimination against survivors of the atomic bomb. No consistent relation was observed between radiation exposure and three reproductive indices: childless marriages, number of births, and interval between marriage and first birth.

  18. Transcriptional profiling of Saccharomyces cerevisiae exposed to propolis

    PubMed Central

    2012-01-01

    Background Propolis is a natural product of plant resins collected by honeybees (Apis mellifera) from various plant sources. Our previous studies indicated that propolis sensitivity is dependent on the mitochondrial function and that vacuolar acidification and autophagy are important for yeast cell death caused by propolis. Here, we extended our understanding of propolis-mediated cell death in the yeast Saccharomyces cerevisiae by applying systems biology tools to analyze the transcriptional profiling of cells exposed to propolis. Methods We have used transcriptional profiling of S. cerevisiae exposed to propolis. We validated our findings by using real-time PCR of selected genes. Systems biology tools (physical protein-protein interaction [PPPI] network) were applied to analyse the propolis-induced transcriptional bevavior, aiming to identify which pathways are modulated by propolis in S. cerevisiae and potentially influencing cell death. Results We were able to observe 1,339 genes modulated in at least one time point when compared to the reference time (propolis untreated samples) (t-test, p-value 0.01). Enrichment analysis performed by Gene Ontology (GO) Term finder tool showed enrichment for several biological categories among the genes up-regulated in the microarray hybridization such as transport and transmembrane transport and response to stress. Real-time RT-PCR analysis of selected genes showed by our microarray hybridization approach was capable of providing information about S. cerevisiae gene expression modulation with a considerably high level of confidence. Finally, a physical protein-protein (PPPI) network design and global topological analysis stressed the importance of these pathways in response of S. cerevisiae to propolis and were correlated with the transcriptional data obtained thorough the microarray analysis. Conclusions In summary, our data indicate that propolis is largely affecting several pathways in the eukaryotic cell. However, the most

  19. Pulmonary nodules in workers exposed to urban stressor

    SciTech Connect

    Sancini, A.; Fioravanti, M.; Ciarrocca, M.; Palermo, P.; Fiaschetti, M.; Schifano, M.P.; Tomei, G.; Tomei, F.

    2010-07-15

    By multilayer spiral low-dose computed tomography (LD-CT) of the chest this study assesses the early detection of lung lesions on a sample of 100 traffic policemen of a big Italian city professionally exposed to urban pollutants and 100 controls non-occupationally exposed to urban pollutants matched by sex, age, length of service and cigarette smoking habit. Exposure to urban pollutants in traffic policemen was characterized using the annual average concentrations of PM{sub 10}, NO{sub 2} and benzene in the period 1998-2008 measured by fixed monitoring stations located in different areas of the city. A significant and increasing number of suspicious lung nodules with diameters between 5 and 10 mm was observed: in traffic policemen (including smokers and non-smokers) vs. controls (including smokers and non-smokers); in total smokers (including traffic policemen and controls) vs. total non-smokers (traffic policemen and controls); in smoker traffic policemen vs. smoker controls and vs. non-smoker traffic policemen; in non-smoker traffic policemen vs. non-smoker controls. The RR of finding cases with at least one lung nodule with diameters between 5 and 10 mm in traffic policemen (including smokers and non-smokers) compared to controls (including smokers and non-smokers) is 1.94 (CI 1.13-3.31); in total smokers vs. non-smokers the RR is 1.96 (CI 1.20-3.19). The comparison between the interaction exposure and smoking shows an increase in smoker traffic policemen than in smoker controls (RR=2.14; CI 1.02-4.52). The RR for smoker traffic policemen was higher than in non-smoker traffic policemen (RR=2.09; CI 1.19-3.66). The results of our study show that: (1) while smoker workers have a higher risk for developing solid suspicious lung nodules, the simple routinely exposure to urban pollutants is unable to produce the same kind of increased risk; (2) the interaction of smoking and exposure to urban pollutants greatly increases the risk for the development of solid

  20. Engineering a robotic approach to mapping exposed volcanic fissures

    NASA Astrophysics Data System (ADS)

    Parcheta, C. E.; Parness, A.; Mitchell, K. L.

    2014-12-01

    Field geology provides a framework for advanced computer models and theoretical calculations of volcanic systems. Some field terrains, though, are poorly preserved or accessible, making documentation, quantification, and investigation impossible. Over 200 volcanologists at the 2012 Kona Chapman Conference on volcanology agreed that and important step forward in the field over the next 100 years should address the realistic size and shape of volcanic conduits. The 1969 Mauna Ulu eruption of Kīlauea provides a unique opportunity to document volcanic fissure conduits, thus, we have an ideal location to begin addressing this topic and provide data on these geometries. Exposed fissures can be mapped with robotics using machine vision. In order to test the hypothesis that fissures have irregularities with depth that will influence their fluid dynamical behavior, we must first map the fissure vents and shallow conduit to deci- or centimeter scale. We have designed, constructed, and field-tested the first version of a robotic device that will image an exposed volcanic fissure in three dimensions. The design phase included three steps: 1) create the payload harness and protective shell to prevent damage to the electronics and robot, 2) construct a circuit board to have the electronics communicate with a surface-based computer, and 3) prototype wheel shapes that can handle a variety of volcanic rock textures. The robot's mechanical parts were built using 3d printing, milling, casting and laser cutting techniques, and the electronics were assembled from off the shelf components. The testing phase took place at Mauna Ulu, Kīlauea, Hawai'i, from May 5 - 9, 2014. Many valuable design lessons were learned during the week, and the first ever 3D map from inside a volcanic fissure were successfully collected. Three vents had between 25% and 95% of their internal surfaces imaged. A fourth location, a non-eruptive crack (possibly a fault line) had two transects imaging the textures

  1. Cancer mortality among electric utility workers exposed to polychlorinated biphenyls.

    PubMed Central

    Loomis, D; Browning, S R; Schenck, A P; Gregory, E; Savitz, D A

    1997-01-01

    OBJECTIVES: To assess whether excess mortality from cancer, malignant melanoma of the skin, and cancers of the brain and liver in particular, is associated with long term occupational exposure to polychlorinated biphenyls (PCBs). METHODS: An epidemiological study of mortality was conducted among 138,905 men employed for at least six months between 1950 and 1986 at five electrical power companies in the United States. Exposures were assessed by panels composed of workers, hygienists, and managers at each company, who considered tasks performed by workers in 28 job categories and estimated weekly exposures in hours for each job. Poisson regression was used to examine mortality in relation to exposure to electrical insulating fluids containing PCBs, controlling for demographic and occupational factors. RESULTS: Neither all cause nor total cancer mortality was related to cumulative exposure to PCB insulating fluids. Mortality from malignant melanoma increased with exposure; rate ratios (RRs) relative to unexposed men for melanoma were 1.23 (95% confidence interval (95% CI) 0.56 to 2.52), 1.71 (0.68 to 4.28) and 1.93 (0.52 to 7.14) for men with < 2000, > 2000-10,000, and > 10,000 hours of cumulative exposure to PCB insulating fluids, respectively, without consideration of latency. Lagging exposure by 20 years yielded RRs of 1.29 (0.76 to 2.18), 2.56 (1.09 to 5.97), and 4.81 (1.49 to 15.50) for the same exposure levels. Mortality from brain cancer was modestly increased among men with < 2000 hours (RR 1.61, 95% CI 0.86 to 3.01) and > 2000-10,000 hours exposure (RR 1.79, 95% CI 0.81 to 3.95), but there were no deaths from brain cancer among the most highly exposed men. A lag of five years yielded slightly increased RRs. Mortality from liver cancer was not associated with exposure to PCB insulating fluids. CONCLUSIONS: This study was larger and provided more detailed information on exposure than past investigations of workers exposed to PCBs. The results suggest that PCBs

  2. Thrombotic Markers in Metabolic Syndrome Subjects Exposed to Diesel Exhaust

    PubMed Central

    Carlsten, C.; Kaufman, J. D.; Trenga, C. A.; Allen, J.; Peretz, A.; Sullivan, J. H.

    2011-01-01

    Traffic-derived particulate matter (PM) is associated with cardiovascular morbidity and mortality, but the mechanism of this association is unclear. Prothrombotic processes have been linked to PM in epidemiological and animal models, but have not been consistently implicated in controlled human models. Diesel exhaust (DE) is a major contributor to PM. We conducted a controlled human exposure of DE in subjects with metabolic syndrome. The study objective was to evaluate DE exposure effects on prothrombotic markers in a population vulnerable to cardiovascular disease. A randomized, crossover, double-blinded design was used: 16 subjects with metabolic syndrome exposed on 3 different days (≥2 wk washout) to DE at 0 (filtered air, FA), 100 μg PM2.5/m3 (DE100) and 200 μg PM2.5/m3 (DE200). We assessed DE-associated changes in D-dimer, von Willebrand factor (VWF), and plasmin activator inhibitor-1 (PAI-1) at 3, 7, and 22 h after exposure initiation. A DE200-attributable decrease (1.17-fold; CI 1.04 to 1.34) in VWF was noted at 7 h. Significant changes did not occur in other primary endpoints. As previously noted with healthy subjects, strong diurnal patterns in PAI-1 were observed. Thus, in a novel study, we were unable to demonstrate a prothrombotic effect of moderate-dose diesel exhaust exposure in a population at risk for cardiovascular disease. PMID:18668408

  3. Synthesis of protein in intestinal cells exposed to cholera toxin

    SciTech Connect

    Peterson, J.W.; Berg, W.D. Jr.; Coppenhaver, D.H.

    1987-11-01

    The mechanism by which cyclic adenosine monophosphate (AMP), formed by intestinal epithelial cells in response to cholera toxin, ultimately results in alterations in water and electrolyte transport is poorly understood. Several studies have indicated that inhibitors of transcription or translation block much of the transport of ions and water in the intestine and edema formation in tissue elicited by cholera toxin. Data presented in this study confirmed the inhibitory effects of cycloheximide on cholera toxin-induced fluid accumulation in the rabbit intestinal loop model. Neither cycloheximide nor actinomycin D altered the amount of cyclic AMP that accumulated in intestinal cells and Chinese hamster ovary cells exposed to cholera toxin. An increase in (/sup 3/H) leucine incorporation was readily demonstrable in intestinal epithelial cells from rabbits challenged with Vibrio cholerae. Similarly, intestinal epithelial cells incubated with cholera toxin for 4 hr synthesized substantially more protein than controls as determined by relative incorporation of (/sup 35/S) methionine. Most of the new protein synthesized in response to cholera toxin was membrane associated and of high molecular weight. The possible significance of the toxin-induced protein relative to cholera pathogenesis was discussed.

  4. Exposed medical staff: challenges, available tools, and opportunities for improvement.

    PubMed

    Dauer, Lawrence T

    2014-02-01

    Medical staff doses have increased over the past decade, as there is an increasing need for the benefits and use of radiation in medicine. While current average medical staff doses are well within limits, some doses to individuals could exceed 20 mSv y deep dose equivalent or lens dose equivalent (if unprotected), and there is the potential for some workers to exceed 500 mSv y shallow dose equivalent without careful assessment and protection. Nuclear medicine radiochemistry and patient dose preparation present challenging opportunities for improved dose control. In addition, fluoroscopically guided intervention procedures continue to represent an important area for careful protection implementation. Optimization of radiation protection in the medical setting should include tried and true principles of justification, optimization, and limitation with emphasis on training, credentialing, planning, and quality management. As newer and developing uses of radiation in medicine are tested and implemented, it is important to consider effective dosimetric monitoring, lens of eye doses, extremity doses, novel uses, and novel radionuclide characteristics. An ongoing assessment of current and future patterns of use for radiation in medicine is an essential activity to assist in prioritizing limited resources for staff protection. Introduction of Exposed Medical Staff (Video 1:27, http://links.lww.com/HP/A20).

  5. Long-term study on workers occupationally exposed to ethylbenzene.

    PubMed

    Bardodĕj, Z; Círek, A

    1988-01-01

    Ethylbenzene is synthesized from benzene; subject to catalytic dehydrogenation it yields styrene, a raw material for the production of synthetic rubber and plastics. Long-term biomonitoring of occupational ethylbenzene exposures, carried out in the past 20 years in some 200 ethylbenzene-production workers, revealed this substance to pose little hazard to human health. As it turned out, mandelic acid concentrations in these workers' urine never exceeded 3.25 mmol.l-1 and none of the exposed showed damage to hematopoiesis and/or liver tissue. Over the last 10 years no case of malignancy has been recorded in this industrial facility belonging to a larger chemical complex where the overall incidence of cancer is about 3 times the national average. Today's low-level ethylbenzene exposures would make it fully justifiable if the present-day MAC limits, both whole-shift (200 mg.m-3) and peak (1,000 mg.m-3), were to be halved, i.e. to be lowered to 100 mg.m3 and 500 mg.m3 respectively. These newly recommended limit values are no more exceeded nowadays.

  6. Surface characteristics of dentin experimentally exposed to hydrofluoric acid.

    PubMed

    Pioch, Thomas; Jakob, Heiko; García-Godoy, Franklin; Götz, Hermann; Dörfer, Christof E; Staehle, Hans J

    2003-08-01

    The purpose of this study was to test the effect of hydrofluoric acid (HF) on the surface characteristics of dentin in vitro. Dentin was exposed in 50 human molars and divided into five groups according to different etching schedules: (i) no etching, (ii) 15 s HF, (iii) 15 s H3PO4, (iv) 15 s HF and 15 s H3PO4, (v) 15 s H3PO4 and 15 s HF. Teeth were examined under a scanning electron microscope equipped with energy-dispersive X-ray (EDX) or two layers of fluorescence-labeled primer followed by the composite were applied, and the teeth were sectioned and examined using confocal laser scanning microscopy (CLSM). With scanning electron microscopy, no openings of dentinal tubules were found in groups (i), (ii), and (iv). In group (v) only a few tubules were opened and in group (iii) the smear layer was completely removed and tubules appeared open. The EDX analysis revealed that fluoride was incorporated into the dentin surface when HF was used. With CLSM, distinct hybrid layers could be detected only in group (iii). In group (v) the hybrid layer appeared less established compared with group (iii). No dentin hybridization was found in groups (i), (ii), and (iv). It is concluded that HF has the ability to close the openings of dentin tubules which were opened due to etching by phosphoric acid and cannot dissolve the smear layer.

  7. Environmental and biological monitoring of workers exposed to inorganic lead.

    PubMed

    De Medinilla, J; Espigares, M

    1991-01-01

    A total of 20 workers who were exposed to inorganic lead in two local firms (M and N) were studied. Lead concentrations in the air (PbA) at firm M exceeded the threshold limit value (TLV) of 0.150 mg/m3 established by Spanish and EC legislation, while atmospheric lead at firm N exceeded the action level of 0.075 mg/m3. In the same population, biological exposure indices (BEI) were also determined; these included lead in whole blood (PbB), erythrocyte activity of aminolevulinic acid (ALA-D), urinary excretion of aminolevulinic acid (ALA-U) and zinc protoporphyrin (ZPP). The relationship between the exposure parameters (PbA, PbB) and the biological activity indices (ALA-D, ALA-U, ZPP) were analysed statistically in order to obtain levels of significance, coefficients of correlation and regression equations. The high coefficients of correlation found confirm the usefulness of BEI in evaluating exposure to lead fumes and lead dust.

  8. RADIOLYTIC GAS PRODUCTION RATES OF POLYMERS EXPOSED TO TRITIUM GAS

    SciTech Connect

    Clark, E.

    2013-08-31

    Data from previous reports on studies of polymers exposed to tritium gas is further analyzed to estimate rates of radiolytic gas production. Also, graphs of gas release during tritium exposure from ultrahigh molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, a trade name is Teflon®), and Vespel® polyimide are re-plotted as moles of gas as a function of time, which is consistent with a later study of tritium effects on various formulations of the elastomer ethylene-propylene-diene monomer (EPDM). These gas production rate estimates may be useful while considering using these polymers in tritium processing systems. These rates are valid at least for the longest exposure times for each material, two years for UHMW-PE, PTFE, and Vespel®, and fourteen months for filled and unfilled EPDM. Note that the production “rate” for Vespel® is a quantity of H{sub 2} produced during a single exposure to tritium, independent of length of time. The larger production rate per unit mass for unfilled EPDM results from the lack of filler- the carbon black in filled EPDM does not produce H{sub 2} or HT. This is one aspect of how inert fillers reduce the effects of ionizing radiation on polymers.

  9. Reproductive toxicity of trenbolone acetate in embryonically exposed Japanese quail.

    PubMed

    Quinn, Michael J; Lavoie, Emma T; Ottinger, Mary Ann

    2007-01-01

    This study was conducted to assess the effects of a one time embryonic exposure to trenbolone acetate on reproductive development and function in Japanese quail (Coturnix japonica). Embryos were exposed to either 0.05, 0.5, 5, or 50microg trenbolone or a sesame oil vehicle control at embryonic day 4. Onset of puberty, gonadal histopathology, sperm motility, cloacal gland size, and male copulatory behavior were assessed in adults. Trenbolone delayed onset of puberty in males, inhibited cloacal gland development, and reduced male reproductive behaviors. Industry laboratories have shown trenbolone acetate to be non-teratogenic in mammalian studies. Our study, however, shows that this one time in ovo exposure delayed onset of puberty in and suppressed adult copulatory behavior in quail males. These results suggest that this one time embryonic exposure to trenbolone may have disrupted development of either the central nervous system or the hypothalamic-pituitary-gonadal axis. This is the first study to demonstrate a demasculinizing effect on copulatory behavior in Japanese quail from embryonic exposure to a non-aromatizable androgenic chemical. More studies are needed to determine the mechanisms behind the observed effects.

  10. Discrimination of poorly exposed lithologies in AVIRIS data

    NASA Technical Reports Server (NTRS)

    Farrand, William H.; Harsanyi, Joseph C.

    1993-01-01

    One of the advantages afforded by imaging spectrometers such as AVIRIS is the capability to detect target materials at a sub-pixel scale. This paper presents several examples of the identification of poorly exposed geologic materials - materials which are either subpixel in scale or which, while having some surface expression over several pixels, are partially covered by vegetation or other materials. Sabol et al. (1992) noted that a primary factor in the ability to distinguish sub-pixel targets is the spectral contrast between the target and its surroundings. In most cases, this contrast is best expressed as an absorption feature or features present in the target but absent in the surroundings. Under such circumstances, techniques such as band depth mapping (Clark et al., 1992) are feasible. However, the only difference between a target material and its surroundings is often expressed solely in the continuum. We define the 'continuum' as the reflectance or radiance spanning spectral space between spectral features. Differences in continuum slope and shape can only be determined by reduction techniques which considers the entire spectral range; i.e., techniques such as spectral mixture analysis (Adams et al., 1989) and recently developed techniques which utilize an orthogonal subspace projection operator (Harsanyi, 1993). Two of the three examples considered herein deal with cases where the target material differs from its surroundings only by such a subtle continuum change.

  11. Chromosome aberrations in ataxia telangiectasia cells exposed to heavy ions

    NASA Astrophysics Data System (ADS)

    Kawata, T.; Cucinotta, F.; George, K.; Wu, H.; Shigematsu, N.; Furusawa, Y.; Uno, T.; Isobe, K.; Ito, H.

    Understanding of biological effects of heavy ions is important to assess healt h risk in space. One of the most important issues may be to take into account individual susceptibility. Ataxia telangiectasia (A-T) cells are known to exhibit abnormal responses to radiations but the mechanism of hyper radiosensitivity of A-T still remains unknown. We report chromosome aberrations in normal human fibroblasts and AT fibroblasts exposed to low- and high-LET radiations. A chemical-induced premature chromosome condensation (PCC) technique combined with chromosome- painting technique was applied to score chromosome aberrations in G2/M-phase cells. Following gamma irradiation, GM02052 cells were approximately 5 times more sensitive to g-rays than AG1522 cells. GM02052 cells had a much higher frequency of deletions and misrejoining than AG1522 cells. When the frequency of complex type aberrations was compared, GM02052 cells showed more than 10 times higher frequency than AG1522 cells. The results will be compared with those obtained from high-LET irradiations.

  12. Aldehyde dehydrogenase induction in arsenic-exposed rat bladder epithelium.

    PubMed

    Huang, Ya-Chun; Yu, Hsin-Su; Chai, Chee-Yin

    2016-01-01

    Arsenic is widely distributed in the environment. Many human cancers, including urothelial carcinoma (UC), show a dose-dependent relationship with arsenic exposure in the south-west coast of Taiwan (also known as the blackfoot disease (BFD) areas). However, the molecular mechanisms of arsenic-mediated UC carcinogenesis has not yet been defined. In vivo study, the rat bladder epithelium were exposed with arsenic for 48 h. The proteins were extracted from untreated and arsenic-treated rat bladder cells and utilized two-dimensional gel electrophoresis and mass spectrometry. Selected peptides were extracted from the gel and identified by quadrupole-time of flight (Q-TOF) Ultima-Micromass spectra. The significantly difference expression of proteins in arsenic-treated groups as compared with untreated groups was confirmed by immunohistochemistry (IHC) and western blotting. We found that thirteen proteins were down-regulated and nine proteins were up-regulated in arsenic-treated rat bladder cells when compared with untreated groups. The IHC and western blotting results confirmed that aldehyde dehydrogenase (ALDH) protein was up-regulated in arsenic-treated rat bladder epithelium. Expression of ALDH protein was significantly higher in UC patients from BFD areas than those from non-BFD areas using IHC (p=0.018). In conclusion, the ALDH protein expression could be used as molecular markers for arsenic-induced transformation.

  13. Mortality among dust-exposed Chinese mine and pottery workers

    SciTech Connect

    Chen, J.; McLaughlin, J.K.; Zhang, J.Y.; Stone, B.J.; Luo, J.; Chen, R.A.; Dosemeci, M.; Rexing, S.H.; Wu, Z.; Hearl, F.J. )

    1992-03-01

    A cohort study of approximately 68,000 persons employed during 1972 to 1974 at metal mines and pottery factories in south central China was conducted to evaluate mortality from cancer and other diseases among workers exposed to different levels of silica and other dusts. A follow-up of subjects through December 31, 1989 revealed 6,192 deaths, a number close to that expected based on Chinese national mortality rates. There was, however, a nearly 6-fold increase in deaths from pulmonary heart disease (standard mortality ratio, 581; 95% confidence interval 538 to 626), and a 48% excess of mortality from nonmalignant respiratory diseases (standard mortality ratio, 148; 95% confidence interval, 139 to 158), primarily because of a more than 30-fold excess of pneumoconiosis. Pulmonary heart disease and noncancerous respiratory disease rates rose in proportion to dust exposure. Cancer mortality overall was not increased among the miners or pottery workers. There was no increased risk of lung cancer, except among tin miners, and trends in risk of this cancer with increasing level of dust exposure were not significant. Risks of lung cancer were 22% higher among workers with than without silicosis. The findings indicate that respiratory disease continues to be an occupational hazard among Chinese miners and pottery workers, but that cancer risks are not as yet strongly associated with work in these dusty trades.

  14. Coating concrete secondary containment structures exposed to agrichemicals

    SciTech Connect

    Broder, M.F.; Nguyen, D.T.

    1995-06-01

    Concrete has traditionally been the material of choice for building secondary containment structures because it is relatively inexpensive and has structural properties which make it ideal for supporting the loads of vehicles and large tanks. However, concrete`s chemical properties make it susceptible to corrosion by some common fertilizers. Though fairly impervious to water movement, concrete is easily penetrated by vapors and solvents. It is also prone to cracking. For these reasons, the Environmental Protection Agency (EPA) believes that concrete alone may not provide an effective barrier to pesticide movement and has proposed that concrete in pesticide secondary containment structures be sealed or coated to reduce its permeability. Some state secondary containment regulations require that concrete exposed to fertilizers and pesticides be sealed or protected with a coating. Lacking guidelines, some retailers have used penetrating sealants to satisfy the law, even though these products provide little protection from chemical attack nor do they prevent pesticide egress. Other retailers who have applied thick film coatings which were properly selected have had disastrous results because the application was poorly done. Consequently, much skepticism exists regarding the performance and benefit of protective coatings.

  15. Critical organ concentration of cadmium in occupationally-exposed workers

    SciTech Connect

    Ellis, K.J.; Morgan, W.D.; Yasumura, S.; Vartsky, D.; Zanzi, I.; Cohn, S.H.

    1981-01-01

    This report describes the present Brookhaven facility for in vivo measurements of cadmium in man and provides a comparison with other portable systems. The cadmium detection limits are 2.2 mg in the kidney and 1.5 ppM in the liver for the Brookhaven system. In a recent field study, the cadmium content of the left kidney and concentration in the liver were measured in 82 occupationally exposed workers and 10 control subjects. Organ content ranged up to 57 mg in the kidney and up to 120 ppM in the liver for the industrial group. By contrast, the values for the control group ranged from 0.4 to 11.8 mg for the kidney and 0.7 to 7.9 ppM for the liver. The geometric means were 3.7 mg for the kidney and 2.7 ppM for the liver in the control group. When the data were analyzed to provide an estimate of the critical concentration for the kidney, a range of 300 to 400 ..mu..g/g for the renal cortex was calculated. The corresponding cadmium concentrations in the liver and urine were 30 to 42 ppM (liver) and 22 to 28 ..mu..g/g creatinine (urine), respectively. Blood and urine levels of cadmium and ..beta../sub 2/-microgloubin were also evaluated as possible biological indicators of organ content.

  16. Unique pioneer microbial communities exposed to volcanic sulfur dioxide

    PubMed Central

    Fujimura, Reiko; Kim, Seok-Won; Sato, Yoshinori; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Ohta, Hiroyuki

    2016-01-01

    Newly exposed volcanic substrates contain negligible amounts of organic materials. Heterotrophic organisms in newly formed ecosystems require bioavailable carbon and nitrogen that are provided from CO2 and N2 fixation by pioneer microbes. However, the knowledge of initial ecosystem developmental mechanisms, especially the association between microbial succession and environmental change, is still limited. This study reports the unique process of microbial succession in fresh basaltic ash, which was affected by long-term exposure to volcanic sulfur dioxide (SO2). Here we compared the microbial ecosystems among deposits affected by SO2 exposure at different levels. The results of metagenomic analysis suggested the importance of autotrophic iron-oxidizing bacteria, particularly those involved in CO2 and N2 fixation, in the heavily SO2 affected site. Changes in the chemical properties of the deposits after the decline of the SO2 impact led to an apparent decrease in the iron-oxidizer abundance and a possible shift in the microbial community structure. Furthermore, the community structure of the deposits that had experienced lower SO2 gas levels showed higher similarity with that of the control forest soil. Our results implied that the effect of SO2 exposure exerted a selective pressure on the pioneer community structure by changing the surrounding environment of the microbes. PMID:26791101

  17. Comparative proteomic analysis in Miscanthus sinensis exposed to antimony stress.

    PubMed

    Xue, Liang; Ren, Huadong; Li, Sheng; Gao, Ming; Shi, Shengqing; Chang, Ermei; Wei, Yuan; Yao, Xiaohua; Jiang, Zeping; Liu, Jianfeng

    2015-06-01

    To explore the molecular basis of Sb tolerance mechanism in plant, a comparative proteomic analysis of both roots and leaves in Miscanthus sinensis has been conducted in combination with physiological and biochemical analyses. M. sinensis seedlings were exposed to different doses of Sb, and both roots and leaves were collected after 3 days of treatment. Two-dimensional gel electrophoresis (2-DE) and image analyses found that 29 protein spots showed 1.5-fold change in abundance in leaves and 19 spots in roots, of which 31 were identified by MALDI-TOF-MS and MALDI-TOF-TOF-MS. Proteins involved in antioxidant defense and stress response generally increased their expression all over the Sb treatments. In addition, proteins relative to transcription, signal transduction, energy metabolism and cell division and cell structure showed a variable expression pattern over Sb concentrations. Overall these findings provide new insights into the probable survival mechanisms by which M. sinensis could be adapting to Sb phytotoxicity.

  18. Immunological studies on mice exposed subacutely to methyl isocyanate

    SciTech Connect

    Tucker, A.N.; Bucher, J.R.; Germolec, D.R.; Silver, M.T.; Vore, S.J.; Luster, M.I.

    1987-06-01

    The immunotoxicity of methyl isocyanate (MIC) was evaluated in female B6C3F1 mice exposed via inhalation to 0, 1, or 3 ppm for 6 hr per day on 4 consecutive days. The antibody response to sheep erythrocytes and natural killer cell activity were found to be unaffected by MIC exposure. Although lymphoproliferative responses to mitogens were moderately suppressed by MIC, the differences were not statistically significant. The response of splenic lymphocytes to allogeneic leukocytes in a mixed leukocyte response (MLR) was suppressed in a dose-related fashion and was significantly different from the control response at the 3 ppm level. This effect was thought to be secondary and a result of general toxicity rather than a direct effect of MIC on the immune system. Furthermore, resistance to the infectious agents Listeria monocytogenes, mouse malaria parasite, and influenza virus, or to transplantable tumor cells was not compromised by MIC exposure. Thus, the immune system does not appear to be a primary target for MIC toxicity.

  19. Reproductive effects in birds exposed to pesticides and industrial chemicals

    SciTech Connect

    Fry, D.M.

    1995-10-01

    Environmental contamination by agricultural chemicals and industrial waste disposal results in adverse effects on reproduction of exposed birds. The diversity of pollutants results in physiological effects at several levels, including direct effects on breeding adults as well as developmental effects on embryos. The effects on embryos include mortality or reduced hatchability, failure of chicks to thrive (wasting syndrome), and teratological effects producing skeletal abnormalities and impaired differentiation of the reproductive and nervous systems through mechanisms of hormonal mimicking of estrogens. The range of chemical effects on adult birds covers acute mortality, sublethal stress, reduced fertility, suppression of egg formation, eggshell thinning, and impaired incubation and chick rearing behaviors. The types of pollutants shown to cause reproductive effects include organochlorine pesticides and industrial pollutants, organophosphate pesticides, petroleum hydrocarbons, heavy metals, and in a fewer number of reports, herbicides, and fungicides. o,p`-DDT, polychlorinated biphenyls (PCBs), and mixtures of organochlorines have been identified as environmental estrogens affecting populations of gulls breeding in polluted {open_quotes}hot spots{close_quotes} in southern California, the Great Lakes, and Puget Sound. Estrogenic organochlorines represent an important class of toxicants to birds because differentiation of the avian reproductive system is estrogen dependent. 85 refs.

  20. Physiological responses of three marine microalgae exposed to cypermethrin.

    PubMed

    Wang, Zhao-Hui; Nie, Xiang-Ping; Yue, Wen-Jie; Li, Xin

    2012-10-01

    The effects of cypermethrin on physiological responses of three typical marine microalgal species Skeletonema costatum (Bacillariophyceae), Scrippsiella trochoidea (Dinophyceae), and Chattonella marina (Raphidophyceae), were investigated by 96-h growth tests in a batch-culture system. The 96-h median inhibition concentrations (IC(50)) were 71.4, 205, and 191 μg L(-1) for S. costatum, S. trochoidea, and C. marina, respectively. Quick and significant physiological responses occurred when algal cells were exposed to cypermethrin, and all biochemical parameters varied significantly within 6- or 12-h exposure. Cypermethrin affected algal growth, protein content, and superoxide dismutase (SOD) activity by stimulation at low concentrations (1, 5 μg L(-1)) and inhibition at high concentrations (>50 μg L(-1)). A general increase in malondialdehyde (MDA) level was observed in all test groups, which suggested that the toxic effects of cypermethrin were probably exerted through free radical generation. These results suggest that the activation of SOD and promotion of protein at early exposure are important to counteract the oxidative stress induced by cypermethrin, and the inactivation of SOD may be crucial to the growth inhibition of microalgae by cypermethrin. PMID:21374785

  1. Mutagenesis of Bacillus subtilis spores exposed to simulated space environment

    NASA Astrophysics Data System (ADS)

    Munakata, N.; Natsume, T.; Takahashi, K.; Hieda, K.; Panitz, C.; Horneck, G.

    Bacterial spores can endure in a variety of extreme earthly environments. However, some conditions encountered during the space flight could be detrimental to DNA in the spore, delimiting the possibility of transpermia. We investigate the genetic consequences of the exposure to space environments in a series of preflight simulation project of EXPOSE. Using Bacillus subtilis spores of repair-proficient HA101 and repair-deficient TKJ6312 strains, the mutations conferring resistance to rifampicin were detected, isolated and sequenced. Most of the mutations were located in a N-terminal region of the rpoB gene encoding RNA polymerase beta-subunit. Among several potentially mutagenic factors, high vacuum, UV radiation, heat, and accelerated heavy ions induced mutations with varying efficiencies. A majority of mutations induced by vacuum exposure carried a tandem double-base change (CA to TT) at a unique sequence context of TCAGC. Results indicate that the vacuum and high temperature may act synergistically for the induction of mutations.

  2. Temperature and adrenocortical responses in rhesus monkeys exposed to microwaves

    SciTech Connect

    Lotz, W.G.; Podgorski, R.P.

    1982-12-01

    To determine if the endocrine response to microwave exposure was similar in a primate to that reported for other animals, rectal temperature and plasma levels of cortisol, thyroxine (T4), and growth hormone (GH) were measured in rhesus monkeys exposed to 1.29-GHz microwave radiation. Exposures were carried out under far-field conditions with the monkey restrained in a chair. Incident power densities of 0, 20, 28, and 38 mW/sq cm were used, with corresponding specific absorption rates of 0, 2.1, 3.0, and 4.1 W/kg. Blood samples were taken hourly via an indwelling jugular venous catheter over a 24-h period before, during, and after an 8-h exposure. Rectal temperature increased an average of 0.5, 0.7, and 1.7 C for the three intensities used. No changes in T4 or GH were observed. Cortisol levels were increased during exposure to 38 mW/sq cm. It was concluded that the temperature and adrenocortical responses to microwave exposure of the rhesus monkey are similar to the corresponding responses of other animals.

  3. Pharmaceuticals Exposed to the Space Environment: Problems and Prospects

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.; Myers, Jerry G.

    2016-01-01

    The NASA Human Research Program (HRP) Health Countermeasures Element maintains ongoing efforts to inform detailed risks, gaps, and further questions associated with the use of pharmaceuticals in space. Most recently, the Pharmacology Risk Report, released in 2010, illustrates the problems associated with maintaining pharmaceutical efficacy. Since the report, one key publication includes evaluation of pharmaceutical products stored on the International Space Station (ISS). This study shows that selected pharmaceuticals on ISS have a shorter shelf-life in space than corresponding terrestrial controls. The HRP Human Research Roadmap for planetary exploration identifies the risk of ineffective or toxic medications due to long-term storage during missions to Mars. The roadmap also identifies the need to understand and predict how pharmaceuticals will behave when exposed to radiation for long durations. Terrestrial studies of returned samples offer a start for predictive modeling. This paper shows that pharmaceuticals returned to Earth for post-flight analyses are amenable to a Weibull distribution analysis in order to support probabilistic risk assessment modeling. The paper also considers the prospect of passive payloads of key pharmaceuticals on sample return missions outside of Earth's magnetic field to gather additional statistics. Ongoing work in radiation chemistry suggests possible mitigation strategies where future work could be done at cryogenic temperatures to explore methods for preserving the strength of pharmaceuticals in the space radiation environment, perhaps one day leading to an architecture where pharmaceuticals are cached on the Martian surface and preserved cryogenically.

  4. Mortality among dust-exposed Chinese mine and pottery workers.

    PubMed

    Chen, J; McLaughlin, J K; Zhang, J Y; Stone, B J; Luo, J; Chen, R A; Dosemeci, M; Rexing, S H; Wu, Z; Hearl, F J

    1992-03-01

    A cohort study of approximately 68,000 persons employed during 1972 to 1974 at metal mines and pottery factories in south central China was conducted to evaluate mortality from cancer and other diseases among workers exposed to different levels of silica and other dusts. A follow-up of subjects through December 31, 1989 revealed 6,192 deaths, a number close to that expected based on Chinese national mortality rates. There was, however, a nearly 6-fold increase in deaths from pulmonary heart disease (standard mortality ratio, 581; 95% confidence interval 538 to 626), and a 48% excess of mortality from nonmalignant respiratory diseases (standard mortality ratio, 148; 95% confidence interval, 139 to 158), primarily because of a more than 30-fold excess of pneumoconiosis. Pulmonary heart disease and noncancerous respiratory disease rates rose in proportion to dust exposure. Cancer mortality overall was not increased among the miners or pottery workers. There was no increased risk of lung cancer, except among tin miners, and trends in risk of this cancer with increasing level of dust exposure were not significant. Risks of lung cancer were 22% higher among workers with than without silicosis. The findings indicate that respiratory disease continues to be an occupational hazard among Chinese miners and pottery workers, but that cancer risks are not as yet strongly associated with work in these dusty trades.

  5. Mortality of workers exposed to polychlorinated biphenyls--an update

    SciTech Connect

    Brown, D.P.

    1987-11-01

    A retrospective cohort mortality study of workers exposed to polychlorinated biphenyls (PCBs) in two plants manufacturing electrical capacitors was reported in 1981. The study was conducted primarily to examine the risk of cancer mortality associated with exposure to PCBs. Based on animal data, liver cancer was the disease of most interest. Due to the small number of deaths and a relatively short observation period, the study was considered inconclusive. This study has been updated by adding 7 yr of observation. The number of deaths in the study cohort has increased from 163 to 295. Mortality from all causes was found to be lower than expected (295 observed vs. 318 expected deaths) as well as mortality from all cancers (62 observed vs. 80 expected deaths). A statistically significant excess in deaths was observed in the disease category that includes cancer of the liver (primary and unspecified), gall bladder, and biliary tract (5 observed vs. 1.9 expected; p less than .05). Most of this excess was observed in women employed in one plant. Due to the small number of deaths and the variability of specific cause of death within this category, it remains difficult to interpret these findings in regard to PCB exposure.

  6. Altered innate immune development in HIV-exposed uninfected infants

    PubMed Central

    Reikie, Brian A.; Adams, Rozanne C.M.; Leligdowicz, Aleksandra; Ho, Kevin; Naidoo, Shalena; Rusk, Candice E.; de Beer, Corena; Preiser, Wolfgang; Cotton, Mark F.; Speert, David P.

    2014-01-01

    BACKGROUND Early in life HIV-exposed uninfected (HEU) infants are at an increased risk of morbidity and mortality from infectious disease compared to HIV-unexposed (UE) infants. To improve our understanding of the mechanisms underlying their increased risk, we contrasted innate immune development between HEU and UE infants in a developing world setting, where early-life infectious disease risk is exceptionally high. METHODS A prospective longitudinal cohort of HEU and UE newborns was established and the most detailed characterization to date of HEU infant immune development was performed. Single-cell cytokine production was analyzed by flow cytometry after stimulation of whole blood with pathogen associated molecular patterns (PAMP). RESULTS Monocyte, classical dendritic cell and plasmacytoid dendritic cell composition was similar between HEU and UE infants throughout the first year of life. However, HEU mononuclear cells mounted an enhanced pro-inflammatory response to PAMP stimulation, both in quantity of cytokine produced per-cell and in proportion of responder cells. Significant differences in cytokine production were detected on the single cell level in a PAMP-specific pattern, but only at 2 and 6 weeks of age; all differences normalized by 12 months of age. CONCLUSIONS This time course of innate immune deviation early in life corresponds to the clinical window of vulnerability to infections in HEU infants and may be at least partially responsible for their increased morbidity and mortality from infectious disease. PMID:24732876

  7. The efficiency of photovoltaic cells exposed to pulsed laser light

    NASA Technical Reports Server (NTRS)

    Lowe, R. A.; Landis, G. A.; Jenkins, P.

    1993-01-01

    Future space missions may use laser power beaming systems with a free electron laser (FEL) to transmit light to a photovoltaic array receiver. To investigate the efficiency of solar cells with pulsed laser light, several types of GaAs, Si, CuInSe2, and GaSb cells were tested with the simulated pulse format of the induction and radio frequency (RF) FEL. The induction pulse format was simulated with an 800-watt average power copper vapor laser and the RF format with a frequency-doubled mode-locked Nd:YAG laser. Averaged current vs bias voltage measurements for each cell were taken at various optical power levels and the efficiency measured at the maximum power point. Experimental results show that the conversion efficiency for the cells tested is highly dependent on cell minority carrier lifetime, the width and frequency of the pulses, load impedance, and the average incident power. Three main effects were found to decrease the efficiency of solar cells exposed to simulated FEL illumination: cell series resistance, LC 'ringing', and output inductance. Improvements in efficiency were achieved by modifying the frequency response of the cell to match the spectral energy content of the laser pulse with external passive components.

  8. Long-term follow up of workers exposed to solvents.

    PubMed Central

    Edling, C; Ekberg, K; Ahlborg, G; Alexandersson, R; Barregård, L; Ekenvall, L; Nilsson, L; Svensson, B G

    1990-01-01

    Long term occupational exposure to organic solvents may cause adverse effects to the central nervous system. This collaborative study between six Swedish departments of occupational medicine examines the overall prognosis in terms of working capacity, symptoms, and psychometric test performance for individuals occupationally exposed to organic solvents. After re-analyses of the data from an initial clinical investigation of 111 men, the subjects were divided into two subgroups: one group of 65 with symptoms but no impairment on the tests and one group of 46 with toxic encephalopathy (symptoms and test impairment). At least five years after the initial examination the subjects were asked to attend a re-examination that included a structured medical interview and a psychometric investigation. The results indicate that effects on the central nervous system persist even when exposure has ceased. In the group of 46 more men had stopped working and were receiving sickness or early retirement pensions. This group also had reduced activity levels with regard to everyday life, leisure activities, and education or training and more neuropsychiatric symptoms. There was no support for the view that a solvent induced toxic encephalopathy is a progressive disease comparable with presenile dementia such as Alzheimer's disease or Pick's disease. If a worker was removed from exposure when he presented symptoms without signs of impairment in intellectual function recovery was seen in most cases. PMID:2178676

  9. Subaerially exposed Holocene coral reef, Enriquillo Valley, Dominican Republic

    NASA Technical Reports Server (NTRS)

    Mann, P.; Taylor, F. W.; Burke, K.; Kulstad, R.

    1984-01-01

    An extremely well-preserved Holocene fringing coral reef occurs at an average elevation of 5 m below sea level around the margins of the central Enriquillo Valley, Dominican Republic. The reef records the latest marine incursion from the east into an 85-km-long, 12-km-wide tectonic depression and appears to represent a unique preservation. Excellent cross sections of the reef exposed in erosional gullies reveal a composition and zonation typical of modern Caribbean reefs that are found in offshore low-energy environments. Radiocarbon age determinations (2) indicate that reef growth coincided with sea-level rise following the last ice age (5,930 + or - 100 to 4,760 + or - 90 yr B.P.). Deltaic deposition and possible vertical movements on active fault scarps dammed the eastern mouth of the valley and created Lago Enriquillo, the level of which was then rapidly lowered by evaporation in an arid climate to produce a saline lake approximately 40 m below sea level. Stratigraphic studies of rocks along the valley edge and data from drill holes in the basin center indicate that there were earlier post-Miocene marine incursions similar to that described here.

  10. Measuring exposed magnetic fields of welders in working time.

    PubMed

    Yamaguchi-Sekino, Sachiko; Ojima, Jun; Sekino, Masaki; Hojo, Minoru; Saito, Hiroyuki; Okuno, Tsutomu

    2011-01-01

    The assessment of the occupational electromagnetic field exposure of welders is of great importance, especially in shielded-arc welding, which uses relatively high electric currents of up to several hundred amperes. In the present study, we measured the magnetic field exposure level of welders in the course of working. A 3-axis Hall magnetometer was attached to a subject's wrist in order to place the sensor probe at the closest position to the magnetic source (a cable from the current source). Data was acquired every 5 s from the beginning of the work time. The maximum exposed field was 0.35-3.35 mT (Mean ± SD: 1.55 ± 0.93 mT, N=17) and the average value per day was 0.04-0.12 mT (Mean ± SD: 0.07 ± 0.02 mT, N=17). We also conducted a finite element method-based analysis of human hand tissue for the electromagnetic field dosimetry. In addition, the magnetic field associated with grinders, an air hammer, and a drill using electromagnetic anchorage were measured; however, the magnetic fields were much lower than those generated in the welding process. These results agreed well with the results of the electromagnetic field dosimetry (1.49 mT at the wrist position), and the calculated eddy current (4.28 mA/m(2)) was much lower than the well-known guideline thresholds for electrical nerve or muscular stimulation.

  11. Medical monitoring of asbestos-exposed workers: experience from Poland.

    PubMed

    Świątkowska, Beata; Szeszenia-Dąbrowska, Neonila; Wilczyńska, Urszula

    2016-08-01

    In Poland, the use of asbestos was banned in 1997 and asbestos plants have been closed since then. Despite their closure, cases of asbestos-related occupational diseases among former asbestos workers are still being recorded in the Central Register of Occupational Diseases. Between 2001 and 2014, there were 2726 asbestos-related illnesses, classified and reported as diseases associated with occupational exposure to asbestos. In 2000, Poland introduced a programme called Amiantus, targeted at former asbestos-processing plant workers. The programme provided periodic medical examinations to workers and free access to medications for treatment of asbestos-related illnesses. Introduction of the programme provided additional data to generate a reliable estimation of the number of asbestos-related occupational diseases, including cancer. The average latency period for asbestosis, lung cancer and mesothelioma is about 40 years so there may still be some health impact to former workers necessitating follow-up. We present the Polish experience of implementing a medical examination programme for asbestos-exposed workers and provide a list of activities to consider when planning for such a programme.

  12. OPC Paste Samples Exposed To Aggressive Solutions. Cementitious Barriers Partnership

    SciTech Connect

    Langton, C.

    2014-11-01

    The study presented in this report focused on a low-activity wasteform containing a high-pH pore solution with a significant level of sulfate. The purpose of the study was to improve understanding of the complex concrete/wasteform reactive transport problem, in particular, the role of pH in sulfate attack. Paste samples prepared at three different water-to-cement ratios were tested. The mixtures were prepared with ASTM Type I cement, without additional admixtures. The samples were exposed to two different sodium sulfate contact solutions. The first solution was prepared at 0.15M Na2SO4. The second solution also incorporated 0.5M NaOH, to mimic the high pH conditions found in Saltstone. The data collected indicated that, in Na2SO4 solution, damage occurs to the pastes. In the case of the high-pH sulfate solution (Na2SO4 + NaOH), no signs of damage were observed on any of the paste mixtures. These results indicate that the high sulfate content found in the wasteform pore solution will not necessarily lead to severe damage to concrete. Good-quality mixtures could thus prove durable over the long term, and act as an effective barrier to prevent radionuclides from reaching the environment.

  13. Osmotic thirst suppression in dogs exposed to low ambient temperature.

    PubMed

    Sobocińska, J; Kozłowski, S

    1987-01-01

    Body temperature, urine output, osmotic and free water clearances, plasma osmolality, sodium and potassium concentrations, blood lactate level, osmotic thirst and central blood volume were measured in dogs exposed to cold (+1 to -8 degrees C) for 1-3 hours and compared to those obtained under control conditions at ambient temperatures (18-20 degrees C). In some additional experiments osmotic thirst threshold and arterial blood pressure during intravenous infusion of norepinephrine were also examined. Exposure to low ambient temperature caused an increase in the osmotic thirst threshold and rise in central blood volume. Transient increase in the urine output and free water clearance accompanied by a decrease in the urine osmolality were also observed. No changes were found in rectal temperature, plasma osmolality and plasma sodium concentration. Infusion of norepinephrine elevated the osmotic thirst threshold in a dose-dependent manner. It is concluded that the cold-induced suppression of osmotic thirst may result from the increased central blood volume. A possible involvement of the sympathetic nervous system in the thirst inhibition in low ambient temperature is also considered.

  14. Lung Cancer in Railroad Workers Exposed to Diesel Exhaust

    PubMed Central

    Garshick, Eric; Laden, Francine; Hart, Jaime E.; Rosner, Bernard; Smith, Thomas J.; Dockery, Douglas W.; Speizer, Frank E.

    2004-01-01

    Diesel exhaust has been suspected to be a lung carcinogen. The assessment of this lung cancer risk has been limited by lack of studies of exposed workers followed for many years. In this study, we assessed lung cancer mortality in 54,973 U.S. railroad workers between 1959 and 1996 (38 years). By 1959, the U.S. railroad industry had largely converted from coal-fired to diesel-powered locomotives. We obtained work histories from the U.S. Railroad Retirement Board, and ascertained mortality using Railroad Retirement Board, Social Security, and Health Care Financing Administration records. Cause of death was obtained from the National Death Index and death certificates. There were 43,593 total deaths including 4,351 lung cancer deaths. Adjusting for a healthy worker survivor effect and age, railroad workers in jobs associated with operating trains had a relative risk of lung cancer mortality of 1.40 (95% confidence interval, 1.30–1.51). Lung cancer mortality did not increase with increasing years of work in these jobs. Lung cancer mortality was elevated in jobs associated with work on trains powered by diesel locomotives. Although a contribution from exposure to coal combustion products before 1959 cannot be excluded, these results suggest that exposure to diesel exhaust contributed to lung cancer mortality in this cohort. PMID:15531439

  15. Cancer occurrence in shipyard workers exposed to asbestos in Hawaii.

    PubMed

    Kolonel, L N; Yoshizawa, C N; Hirohata, T; Myers, B C

    1985-08-01

    Because large numbers of persons were employed in United States shipyards during World War II, the long-term risks for cancer associated with asbestos exposure in this setting are of great concern. We report here on the mortality findings after up to 29 years of follow-up on a retrospective cohort of 7971 male Pearl Harbor Naval Shipyard workers, which included more than 3000 men whose employment period spanned the World War II years. Compared with the general population of Hawaii, workers in the shipyard cohort had no increase in total mortality or in total cancer mortality irrespective of the duration of their exposure. However, the risk ratio for lung cancer among workers with at least 15 years of asbestos exposure was 1.4 overall (95% confidence interval, 1.0 to 2.0) and 1.7 for those with a latency interval of 30 or more years (95% confidence interval, 1.0 to 2.5). In addition, seven mesotheliomas occurred between 1977 and 1982 in a subset of the cohort, consisting of 7029 Hawaii residents who are being followed prospectively for cancer incidence. This represented an incidence of 67.3 per million men per year, compared with a rate of 5.8 for the state as a whole. These results suggest that the long-term relative increase in risk for mesothelioma may be even greater than that for bronchogenic carcinoma in this and other cohorts of United States shipyard workers exposed to asbestos.

  16. Lung injury in mice and rats acutely exposed to beryllium

    SciTech Connect

    Sendelbach, L.E. Jr.

    1985-01-01

    The effect of lung injury, in rats and mice, exposed to an aerosol of beryllium sulfate (BE) for one hour, through nose-only inhalation, was evaluated by the methods of bronchoalveolar lavage (BAL) and lung cell kinetics. The BAL in rats, sacrificed over a 21 day period following exposure, showed lactate dehydrogenase (LDH) and alkaline phosphatase (Alk Pase) activities as the most sensitive indicators of lung damage. LDH activity peaked at day 8 while Alk Pase activity peaked at day 5, both being 30 times greater than comparable control values. Acid phosphatase activity and albumin levels were also increased, but not to the same extent as LDH and Alk Pase. The BAL of mice showed LDH activity as the most sensitive indicator of lung damage, with a maximum response 3 times greater than controls at day 5. In another series of experiments, animals were treated with three agents capable of inducing fibrosis: beryllium sulfate, bleomycin, and butylated hydroxytoluene (BHT). Cy A completely inhibited the fibrogenic effects of BHT in mice, as measured through total lung hydroxyproline content. Bleomycin-induced fibrosis was significantly reduced by Cy A treatment in rats, but showed no effect in mice. Additionally, the effect of iron salt administration to rats decreased the intravenous LD/sub 50/ dose, and significantly reduced the inhalation toxicity, of beryllium sulfate. The protective mechanism of iron salt administration, through the induction of ferritin synthesis, is postulated.

  17. Reproductive effects in birds exposed to pesticides and industrial chemicals.

    PubMed

    Fry, D M

    1995-10-01

    Environmental contamination by agricultural chemicals and industrial waste disposal results in adverse effects on reproduction of exposed birds. The diversity of pollutants results in physiological effects at several levels, including direct effects on breeding adults as well as developmental effects on embryos. The effects on embryos include mortality or reduced hatchability, failure of chicks to thrive (wasting syndrome), and teratological effects producing skeletal abnormalities and impaired differentiation of the reproductive and nervous systems through mechanisms of hormonal mimicking of estrogens. The range of chemical effects on adult birds covers acute mortality, sublethal stress, reduced fertility, suppression of egg formation, eggshell thinning, and impaired incubation and chick rearing behaviors. The types of pollutants shown to cause reproductive effects include organochlorine pesticides and industrial pollutants, organophosphate pesticides, petroleum hydrocarbons, heavy metals, and in a fewer number of reports, herbicides, and fungicides. o,p'-DDT, polychlorinated biphenyls (PCBs), and mixtures of organochlorines have been identified as environmental estrogens affecting populations of gulls breeding in polluted "hot spots" in southern California, the Great Lakes, and Puget Sound. Estrogenic organochlorines represent an important class of toxicants to birds because differentiation of the avian reproductive system is estrogen dependent. PMID:8593865

  18. DNA damage in mouse lymphocytes exposed to curcumin and copper.

    PubMed

    Urbina-Cano, Patricia; Bobadilla-Morales, Lucina; Ramírez-Herrera, Mario A; Corona-Rivera, Jorge R; Mendoza-Magaña, Maria L; Troyo-Sanromán, Rogelio; Corona-Rivera, Alfredo

    2006-01-01

    Dietary polyphenolics, such as curcumin, have shown antioxidant and anti-inflammatory effects. Some antioxidants cause DNA strand breaks in excess of transition metal ions, such as copper. The aim of this study was to evaluate the in vitro effect of curcumin in the presence of increasing concentrations of copper to induce DNA damage in murine leukocytes by the comet assay. Balb-C mouse lymphocytes were exposed to 50 microM curcumin and various concentrations of copper (10 microM, 100 microM and 200 microM). Cellular DNA damage was detected by means of the alkaline comet assay. Our results show that 50 microM curcumin in the presence of 100-200 microM copper induced DNA damage in murine lymphocytes. Curcumin did not inhibit the oxidative DNA damage caused by 50 microM H2O2 in mouse lymphocytes. Moreover, 50 microM curcumin alone was capable of inducing DNA strand breaks under the tested conditions. The increased DNA damage by 50 mM curcumin was observed in the presence of various concentrations of copper, as detected by the alkaline comet assay. PMID:17132903

  19. Toxicogenomic profiling of chemically exposed humans in risk assessment

    PubMed Central

    McHale, Cliona M.; Zhang, Luoping; Hubbard, Alan E.; Smith, Martyn T.

    2010-01-01

    Gene-environment interactions contribute to complex disease development. The environmental contribution, in particular low-level and prevalent environmental exposures, may constitute much of the risk and contribute substantially to disease. Systematic risk evaluation of the majority of human chemical exposures, has not been conducted and is a goal of regulatory agencies in the U.S. and worldwide. With the recent recognition that toxicological approaches more predictive of effects in humans are required for risk assessment, in vitro human cell line data as well as animal data are being used to identify toxicity mechanisms that can be translated into biomarkers relevant to human exposure studies. In this review, we discuss how data from toxicogenomic studies of exposed human populations can inform risk assessment, by generating biomarkers of exposure, early effect, and/or susceptibility, elucidating mechanisms of action underlying exposure-related disease, and detecting response at low doses. Good experimental design incorporating precise, individual exposure measurements, phenotypic anchors (pre-disease or traditional toxicological markers), and a range of relevant exposure levels, is necessary. Further, toxicogenomic studies need to be designed with sufficient power to detect true effects of the exposure. As more studies are performed and incorporated into databases such as the Comparative Toxicogenomics Database (CTD) and Chemical Effects in Biological Systems (CEBS), data can be mined for classification of newly tested chemicals (hazard identification), and, for investigating the dose-response, inter-relationship among, genes, environment and disease in a systems biology approach (risk characterization). PMID:20382258

  20. Stable chromosome aberration frequencies in men occupationally exposed to radiation.

    PubMed

    Tawn, E Janet; Whitehouse, Caroline A

    2003-09-01

    The introduction of fluorescence in situ hybridisation techniques to cytogenetic biodosimetry has enabled the detection of stable aberrations, e.g. translocations, which can provide an integrated measure of radiation exposure. The opportunity to study stable aberration frequencies in lymphocyte cultures from occupationally exposed workers with well-documented dosimetry records enables the establishment of dose-response relationships which can be compared with those obtained from studies of populations with high acute exposures. Since there is good mechanistic evidence for the role of translocations in oncogenesis, this provides an insight into the risks associated with low-dose exposure for which no direct epidemiological evidence is available. This paper provides preliminary data on a group of 98 individuals with cumulative occupational doses > 500 mSv and 96 controls with doses < 50 mSv. An increased frequency of translocations was found for the high-dose group (20.50 +/- 0.78 x 10(-3) per genome equivalent) in comparison with the control group (11.71 +/- 0.59 x 10(-3) per genome equivalent). Further analysis of the control group revealed increasing frequencies of translocations with increasing age. An increase associated with ever-smoking status was found for the control group which appeared to be driven by the lower age groups but no overall effect of smoking was seen in the > 500 mSv group.

  1. Donation to disaster relief campaigns: underlying social cognitive factors exposed.

    PubMed

    Oosterhof, Liesbeth; Heuvelman, Ard; Peters, Oscar

    2009-05-01

    A number of very serious natural disasters have put an enormous pressure on relief organizations in the last few years. The present study exposes underlying social cognitive factors for donation to relief campaigns. A causal model was constructed, based on social cognitive theory, research on attitudes, and the impact of media exposure. The aim was to expand and improve an already existing model by Cheung and Chan [Cheung, C. K., & Chan, C. M. (2000). Social-cognitive factors of donating money to charity, with special attention to an international relief organisation. Evaluation and Program Planning, 23, 241-253]. The expanded model showed a better fit. Furthermore, the expanded model explained two-thirds of the variance of the intention to donate to a disaster relief campaign. The greatest predictor of the intention to donate proved to be "Past donation to disaster relief campaigns." The factor "News exposure" was indicated to be a valuable additional factor, as it had a significant direct effect on "Awareness of a disaster relief campaign" and was the only factor that had a total effect on all other factors, including "Intention to donate to a disaster relief campaign."

  2. Biomonitoring of traffic police officers exposed to airborne platinum

    PubMed Central

    Iavicoli, I; Bocca, B; Petrucci, F; Senofonte, O; Carelli, G; Alimonti, A; Caroli, S

    2004-01-01

    Background: Over the past two decades there has been a substantial increase in environmental levels of palladium, platinum, and rhodium, the platinum group elements (PGEs), due to the widespread use of catalytic converters for automotive traction. Aim: To evaluate urinary platinum levels in occupationally exposed subjects. Methods: A total of 161 employees from the Rome City Police Force were studied; 103 were traffic police involved in controlling streets with an average flow of vehicles, while the remaining 58 were control subjects engaged only in office work. Platinum quantification in the urine samples of these subjects was carried out by sector field inductively coupled plasma mass spectrometry. Results: There were no statistically significant differences between platinum levels in the group of subjects engaged in traffic control and the control group (4.45 (2.42) ng/l v 4.56 (2.84) ng/l, respectively). Conclusions: Urinary levels were found to be higher than those reported for other urban populations, thus showing a progressive increase in human exposure to Pt. PMID:15208381

  3. Limitations of rupture forecasting exposed by instantaneously triggered earthquake doublet

    NASA Astrophysics Data System (ADS)

    Nissen, E.; Elliott, J. R.; Sloan, R. A.; Craig, T. J.; Funning, G. J.; Hutko, A.; Parsons, B. E.; Wright, T. J.

    2016-04-01

    Earthquake hazard assessments and rupture forecasts are based on the potential length of seismic rupture and whether or not slip is arrested at fault segment boundaries. Such forecasts do not generally consider that one earthquake can trigger a second large event, near-instantaneously, at distances greater than a few kilometres. Here we present a geodetic and seismological analysis of a magnitude 7.1 intracontinental earthquake that occurred in Pakistan in 1997. We find that the earthquake, rather than a single event as hitherto assumed, was in fact an earthquake doublet: initial rupture on a shallow, blind reverse fault was followed just 19 s later by a second rupture on a separate reverse fault 50 km away. Slip on the second fault increased the total seismic moment by half, and doubled both the combined event duration and the area of maximum ground shaking. We infer that static Coulomb stresses at the initiation location of the second earthquake were probably reduced as a result of the first. Instead, we suggest that a dynamic triggering mechanism is likely, although the responsible seismic wave phase is unclear. Our results expose a flaw in earthquake rupture forecasts that disregard cascading, multiple-fault ruptures of this type.

  4. Optimization of Routine Monitoring of Workers Exposed to Plutonium Aerosols.

    PubMed

    Davesne, Estelle; Quesne, Benoit; De Vita, Antoine; Chojnacki, Eric; Blanchardon, Eric; Franck, Didier

    2016-10-01

    In case of incidental confinement failure, mixed oxide (MOX) fuel preparation may expose workers to plutonium aerosols. Due to its potential toxicity, occupational exposure to plutonium compounds should be kept as low as reasonably achievable. To ensure the absence of significant intake of radionuclides, workers at risk of internal contamination are monitored by periodic bioassay planned in a routine monitoring programme. From bioassay results, internal dose may be estimated. However, accurate dose calculation relies on known exposure conditions, which are rarely available when the exposure is demonstrated by routine monitoring only. Therefore, internal dose calculation is subject to uncertainty from unknown exposure conditions and from activity measurement variability. The present study calculates the minimum detectable dose (MDD) for a routine monitoring programme by considering all plausible conditions of exposure and measurement uncertainty. The MDD evaluates the monitoring quality and can be used for optimization. Here, MDDs were calculated for the monitoring of workers preparing MOX fuel. Uncertain parameters were modelled by probability distributions defined according to information provided by experts of routine monitoring, of workplace radiological protection and of bioassay analysis. Results show that the current monitoring is well adapted to potential exposure. A sensitivity study of MDD highlights high dependence on exposure condition modelling. Integrating all expert knowledge is therefore crucial to obtain reliable MDD estimates, stressing the value of a holistic approach to worker monitoring.

  5. Biomonitoring of persons exposed to insecticides used in residences.

    PubMed

    Krieger, R I; Bernard, C E; Dinoff, T M; Ross, J H; Williams, R L

    2001-04-01

    Pesticides used indoors inevitably result in some unintentional and unavoidable exposures of residents. Measured dosages of residents are well below toxic levels. Exposures (microg/kg-day) are substantially less and occur over a longer time than suggested by unvalidated estimates derived from previous extreme, conservative default assumptions based solely on environmental residues. Human chlorpyrifos exposures were monitored following three different types of applications: fogger, broadcast, and crack-and-crevice. Persistence of total residue on carpet was substantially greater than the persistence of transferable residue (microg/cm(2)). Low-level (microg/kg) exposures of family members persisted for periods of weeks to a month after pesticide use. Although few children who resided with their parents in pest-protected homes have been monitored, they eliminated more biomarker than their parents on a kg body weight-day basis when absorbed dosages (microg/kg-day) were derived from spot urine specimens corrected for volume by an age-specific creatinine correction. Ultimately environmental residues may become useful elements of predictive residential exposure models, but their potential contribution to indirect exposure assessments must include careful determination of residue availability for contact transfer to clothing or skin and biological validation. When environmental data from monitoring studies reported here were used to estimate residential exposure according to Residential Exposure Assessment Standard Operating Procedures (SAP meeting, 1997), measured exposures were substantially less than assessments. Experimental and situational monitoring of exposed persons is essential for meaningful and responsible predictive resident exposure model building. PMID:11290360

  6. Risk of Hepatocellular Carcinoma in Workers Exposed to Chemicals

    PubMed Central

    Uccello, Mario; Malaguarnera, Giulia; Corriere, Thea; Biondi, Antonio; Basile, Francesco; Malaguarnera, Mariano

    2012-01-01

    Context Studies on experimental animals have shown liver is a common target of chemical carcinogens; this might suggest that occupational exposure to chemicals is another risk factor for HCC. However, the relationship between occupation and liver cancer has not been extensively studied, with the exception of the known association between vinyl chloride and angiosarcoma of the liver. Evidence Acquisition A MEDLINE and conventional search of the past 50 years of the medical literature was performed to identify relevant articles on incidence and mechanisms of HCC due to occupational exposure to chemicals. Several important edited books and monographs were also identified and reviewed. Results While laboratory data clearly indicate that the liver is an important target of chemical carcinogenesis, epidemiological studies provide very limited evidence on occupational risk factors for HCC. Nevertheless, we found some case reports and epidemiological data showing a moderately increased risk of HCC development in people exposed to vinyl chloride, organic solvents, pesticides, polychlorinated biphenyls, and arsenic. Conclusions Occupational exposure to chemicals may be another risk factor for HCC development, but the interpretation of currently available findings is limited by the small number of studies, questionable accuracy of the diagnosis of liver cancer, and potential confounding or modifying factors such as chronic hepatitis virus infection and alcohol consumption. Further relevant investigations are required for clarifying the actual contribution of occupational exposure to chemicals in HCC development. PMID:23162599

  7. Exposing Middle School Students to Remote Sensing in Alaska

    NASA Astrophysics Data System (ADS)

    Prakash, A.

    2003-12-01

    The need for attracting young minds to scientific research at an early stage is already recognized. Efforts are underway by major organizations to inspire the next generation of scientists. To be effective, there is a need to exploit the potential of the World Wide Web and bring it to a status that printed media have already reached. We find series of theme oriented books for children but websites with such stories are few and scattered. NASA's efforts in generating remote sensing based web stories such as the 'Adventures of Amelia the Pigeon' and 'Echo the Bat' are very good examples and starting points for generating more theme based material for children. 'Alaska: A Bird's Eye View' is a web-based story, specifically designed for grade 5-8 students. The story that is told by a Canada Goose exposes children to the truths of the remote State of Alaska and to the potential of satellite remote sensing. Examples on use remote sensing for monitoring volcanoes and sea ice edge dynamics are related to children in simple and effective ways. The topic of global climate change and its effect on marine animals has also been introduced to children.

  8. Unique pioneer microbial communities exposed to volcanic sulfur dioxide

    NASA Astrophysics Data System (ADS)

    Fujimura, Reiko; Kim, Seok-Won; Sato, Yoshinori; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Ohta, Hiroyuki

    2016-01-01

    Newly exposed volcanic substrates contain negligible amounts of organic materials. Heterotrophic organisms in newly formed ecosystems require bioavailable carbon and nitrogen that are provided from CO2 and N2 fixation by pioneer microbes. However, the knowledge of initial ecosystem developmental mechanisms, especially the association between microbial succession and environmental change, is still limited. This study reports the unique process of microbial succession in fresh basaltic ash, which was affected by long-term exposure to volcanic sulfur dioxide (SO2). Here we compared the microbial ecosystems among deposits affected by SO2 exposure at different levels. The results of metagenomic analysis suggested the importance of autotrophic iron-oxidizing bacteria, particularly those involved in CO2 and N2 fixation, in the heavily SO2 affected site. Changes in the chemical properties of the deposits after the decline of the SO2 impact led to an apparent decrease in the iron-oxidizer abundance and a possible shift in the microbial community structure. Furthermore, the community structure of the deposits that had experienced lower SO2 gas levels showed higher similarity with that of the control forest soil. Our results implied that the effect of SO2 exposure exerted a selective pressure on the pioneer community structure by changing the surrounding environment of the microbes.

  9. Preventing alcohol-exposed pregnancy among American-Indian youth

    PubMed Central

    Jensen, Jamie; Baete Kenyon, Den Yelle; Hanson, Jessica D.

    2015-01-01

    Research has determined that the prevention of alcohol-exposed pregnancies (AEP) must occur pre-conceptually with women, either by reducing alcohol intake in women planning pregnancy or at-risk for becoming pregnant, or by preventing pregnancy in women drinking at risky levels. One such AEP prevention programme with non-pregnant American Indian women is the Oglala Sioux Tribe (OST) CHOICES (Changing High-risk alcohOl use and Increasing Contraception Effectiveness Study) Programme, which shows promise in reducing AEP risk in American Indian women aged 18 or older. A community needs assessment was conducted with key informant interviews and focus groups with an emphasis on how to expand OST CHOICES. To identify interconnected themes, a content analysis methodology was used on the qualitative feedback from the focus groups and interviews. Altogether, key informant interviews were completed with 25 health and social service professionals. Eight focus groups were held with 58 American Indian participants, including adult women of child-bearing age, elder women, and adult men. Several sub-themes regarding the prevention of AEP with youth were identified, expanding the OST CHOICES curriculum into the schools, and the role of family and culture within AEP prevention. PMID:27429593

  10. Aldehyde dehydrogenase induction in arsenic-exposed rat bladder epithelium.

    PubMed

    Huang, Ya-Chun; Yu, Hsin-Su; Chai, Chee-Yin

    2016-01-01

    Arsenic is widely distributed in the environment. Many human cancers, including urothelial carcinoma (UC), show a dose-dependent relationship with arsenic exposure in the south-west coast of Taiwan (also known as the blackfoot disease (BFD) areas). However, the molecular mechanisms of arsenic-mediated UC carcinogenesis has not yet been defined. In vivo study, the rat bladder epithelium were exposed with arsenic for 48 h. The proteins were extracted from untreated and arsenic-treated rat bladder cells and utilized two-dimensional gel electrophoresis and mass spectrometry. Selected peptides were extracted from the gel and identified by quadrupole-time of flight (Q-TOF) Ultima-Micromass spectra. The significantly difference expression of proteins in arsenic-treated groups as compared with untreated groups was confirmed by immunohistochemistry (IHC) and western blotting. We found that thirteen proteins were down-regulated and nine proteins were up-regulated in arsenic-treated rat bladder cells when compared with untreated groups. The IHC and western blotting results confirmed that aldehyde dehydrogenase (ALDH) protein was up-regulated in arsenic-treated rat bladder epithelium. Expression of ALDH protein was significantly higher in UC patients from BFD areas than those from non-BFD areas using IHC (p=0.018). In conclusion, the ALDH protein expression could be used as molecular markers for arsenic-induced transformation. PMID:26482281

  11. Medical monitoring of asbestos-exposed workers: experience from Poland

    PubMed Central

    Szeszenia-Dąbrowska, Neonila; Wilczyńska, Urszula

    2016-01-01

    Abstract In Poland, the use of asbestos was banned in 1997 and asbestos plants have been closed since then. Despite their closure, cases of asbestos-related occupational diseases among former asbestos workers are still being recorded in the Central Register of Occupational Diseases. Between 2001 and 2014, there were 2726 asbestos-related illnesses, classified and reported as diseases associated with occupational exposure to asbestos. In 2000, Poland introduced a programme called Amiantus, targeted at former asbestos-processing plant workers. The programme provided periodic medical examinations to workers and free access to medications for treatment of asbestos-related illnesses. Introduction of the programme provided additional data to generate a reliable estimation of the number of asbestos-related occupational diseases, including cancer. The average latency period for asbestosis, lung cancer and mesothelioma is about 40 years so there may still be some health impact to former workers necessitating follow-up. We present the Polish experience of implementing a medical examination programme for asbestos-exposed workers and provide a list of activities to consider when planning for such a programme. PMID:27516637

  12. Intraspecific diet shift in Talitrus saltator inhabiting exposed sandy beaches

    NASA Astrophysics Data System (ADS)

    Olabarria, Celia; Incera, Mónica; Garrido, Josefina; Rodil, Iván F.; Rossi, Francesca

    2009-09-01

    Talitrid amphipods are the most abundant herbivores on exposed sandy beaches. Despite their important role as trophic intermediates between macrophytes and higher levels (i.e. insect and bird) of beach food webs, very little information is available on their feeding patterns. The main aim of this study was to investigate intraspecific differences in the feeding behaviour of Talitrus saltator. We tested the hypotheses that: (1) adult females and males showed different isotope signatures and therefore relied on different sources of food; and (2) patterns of variation of isotope signatures of juveniles differed from those of adult specimens, evidencing a diet shift during the development. We used stable isotope signatures and tested for differences upon the level on the shore, times of the year and beaches experiencing similar morpho-dynamic and environmental conditions. Finally, we investigated the trophic significance of macrophyte detritus in the diet of males, females and juveniles. Results showed that adult males had a more variable diet than females and juveniles (inferred from δ 13C and δ 15N values). Dual-isotope graphs suggested that Sargassum muticum and Cystoseira baccata wrack could be among the main food sources for both juvenile and adult stage.

  13. Medical monitoring of asbestos-exposed workers: experience from Poland.

    PubMed

    Świątkowska, Beata; Szeszenia-Dąbrowska, Neonila; Wilczyńska, Urszula

    2016-08-01

    In Poland, the use of asbestos was banned in 1997 and asbestos plants have been closed since then. Despite their closure, cases of asbestos-related occupational diseases among former asbestos workers are still being recorded in the Central Register of Occupational Diseases. Between 2001 and 2014, there were 2726 asbestos-related illnesses, classified and reported as diseases associated with occupational exposure to asbestos. In 2000, Poland introduced a programme called Amiantus, targeted at former asbestos-processing plant workers. The programme provided periodic medical examinations to workers and free access to medications for treatment of asbestos-related illnesses. Introduction of the programme provided additional data to generate a reliable estimation of the number of asbestos-related occupational diseases, including cancer. The average latency period for asbestosis, lung cancer and mesothelioma is about 40 years so there may still be some health impact to former workers necessitating follow-up. We present the Polish experience of implementing a medical examination programme for asbestos-exposed workers and provide a list of activities to consider when planning for such a programme. PMID:27516637

  14. Longitudinal epigenetic drift in mice perinatally exposed to lead.

    PubMed

    Faulk, Christopher; Liu, Kevin; Barks, Amanda; Goodrich, Jaclyn M; Dolinoy, Dana C

    2014-07-01

    An understanding of the natural change in DNA methylation over time, defined as "epigenetic drift," will inform the study of environmental effects on the epigenome. This study investigates epigenetic drift in isogenic mice exposed perinatally to lead (Pb) acetate at four concentrations, 0 ppm (control), 2.1 ppm (low), 16 ppm (medium), and 32 ppm (high) prior to conception through weaning, then followed until 10 months of age. Absolute values of DNA methylation in a transposon-associated metastable locus, Cdk5-activator binding protein (Cabp(IAP)), and three imprinted loci (Igf2, Igf2r, and H19) were obtained from tail tissue in paired samples. DNA methylation levels in the controls increased over time at the imprinted Igf2 and Igf2r loci (both P = 0.0001), but not at the imprinted H19 locus or the Cabp(IAP) metastable epiallele. Pb exposure was associated with accelerated DNA hypermethylation in Cabp(IAP) (P = 0.0209) and moderated hypermethylation in Igf2r (P = 0.0447), and with marginally accelerated hypermethylation at H19 (P = 0.0847). In summary, the presence and magnitude of epigenetic drift was locus-dependent, and enhancement of drift was mediated by perinatal Pb exposure, in some, but not all, loci.

  15. Analysis of lung tumor risks in rats exposed to radon.

    PubMed

    Gilbert, E S; Cross, F T; Dagle, G E

    1996-03-01

    Using data on 3117 rats exposed by inhalation to radon, radon progeny and uranium ore dust, the hazard function (or age-specific risk) for lung tumor incidence was modeled as a function of exposure, exposure rate and other factors. The overall estimate of lifetime risk was 237 cases per 10(6) rats per WLM (237 per 10(6) WLM), reasonably comparable to estimates obtained from data for humans. The data below 1000 WLM (20-640 WLM) were consistent with linearity with positive excess risks at all levels; however, evidence of statistically significant excess risk was limited to exposures of 80 WLM or greater. Evidence for an inverse exposure-rate effect was limited primarily to cumulative exposures exceeding 1000 WLM (1280-10,240 WLM) and to comparison of results at 100 and 1000 WL. Even at these levels, the possibility that the effect might be explained by time since last exposure or by heterogeneity across experiments could not be entirely excluded. The inverse exposure-rate effect was strongest for epidermoid and adenosquamous tumors, and the only indication of such an effect at exposures below 1000 WLM was modest evidence (P=0.024) in analyses limited to these tumors. When all lung tumors, or all malignant lung tumors, were included, there was no evidence of such an effect below 1000 WLM. These data support the viewpoint that the inverse exposure-rate effect is primarily a high-dose phenomenon. PMID:8927704

  16. Longitudinal epigenetic drift in mice perinatally exposed to lead

    PubMed Central

    Faulk, Christopher; Liu, Kevin; Barks, Amanda; Goodrich, Jaclyn M; Dolinoy, Dana C

    2014-01-01

    An understanding of the natural change in DNA methylation over time, defined as “epigenetic drift,” will inform the study of environmental effects on the epigenome. This study investigates epigenetic drift in isogenic mice exposed perinatally to lead (Pb) acetate at four concentrations, 0 ppm (control), 2.1 ppm (low), 16 ppm (medium), and 32 ppm (high) prior to conception through weaning, then followed until 10 months of age. Absolute values of DNA methylation in a transposon-associated metastable locus, Cdk5-activator binding protein (CabpIAP), and three imprinted loci (Igf2, Igf2r, and H19) were obtained from tail tissue in paired samples. DNA methylation levels in the controls increased over time at the imprinted Igf2 and Igf2r loci (both P = 0.0001), but not at the imprinted H19 locus or the CabpIAP metastable epiallele. Pb exposure was associated with accelerated DNA hypermethylation in CabpIAP (P = 0.0209) and moderated hypermethylation in Igf2r (P = 0.0447), and with marginally accelerated hypermethylation at H19 (P = 0.0847). In summary, the presence and magnitude of epigenetic drift was locus-dependent, and enhancement of drift was mediated by perinatal Pb exposure, in some, but not all, loci. PMID:24786859

  17. Impairment of colour vision in workers exposed to organic solvents

    PubMed Central

    Semple, S; Dick, F; Osborne, A; Cherrie, J; Soutar, A; Seaton, A; Haites, N

    2000-01-01

    OBJECTIVES—To investigate loss of colour vision related to exposure to solvents and the role of three enzyme polymorphisms in modifying the risk in exposed workers.
METHODS—A sample was studied of 68 male dockyard workers and 42 male community controls with and without neuropsychological symptoms from a previous cross sectional study. Indices of cumulative and intensity based exposure to solvents were calculated for all subjects. Alcohol, drug, and smoking histories were obtained. Colour vision was tested by Lanthony D15d colour vision test. Genotype of glutathione S-transferase M1 and T1 and N-acetyltransferase 2 polymorphisms were determined.
RESULTS—The relation between impairment of colour vision and exposure to solvents was investigated with multiple regression techniques. Increasing annual exposure to solvents was significantly associated with reduced colour vision (p=0.029). Impairment of colour vision was not associated with neuropsychological symptoms as measured by the Q16 solvent symptom questionnaire. No significant association was found between acquired impairment of colour vision and genetic polymorphisms when GSTM1, GSTT1 or NAT2 phenotypes were included in the analyses.
CONCLUSIONS—Exposure to mixed solvents is associated with impairment in colour vision, the risk increases with increasing exposure. The risk of impairment of colour vision was not altered in this study by the presence of different GSTM1, GSTT1 or NAT2 polymorphisms.


Keywords: colour vision; organic solvents; genetic polymorphisms PMID:10935938

  18. WASTE CHARACTERIZATION OF POLYMERIC COMPONENTS EXPOSED TO TRITIUM GAS

    SciTech Connect

    Clark, E

    2008-02-15

    A recent independent review led to uncertainty about the technical basis for characterizing the residual amount of tritium in polymer components used in the Savannah River Site Tritium Facilities that are sent for waste disposal. A review of a paper published in the open literature firmly establishes the basis of the currently used characterization, 10 Ci/cc. Information provided in that paper about exposure experiments performed at the DOE Mound Laboratory allows the calculation of the currently used characterization. These experiments involved exposure of high density polyethylene (HD-PE) to initially 1 atm tritium gas. In addition, a review of recent research at the Savannah River Site not only further substantiates this characterization, but also establishes its use for ultra-high molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, a trade name is Teflon{reg_sign}), and Vespel{reg_sign} polyimide. 10 Ci/cc tritium is a representative characterization for any type of polymer components exposed at ambient temperature and at approximately 1 atm. tritium gas.

  19. Electrocardiographic abnormalities among arsenic-exposed persons through groundwater in Bangladesh.

    PubMed

    Ahmad, S Akhtar; Khatun, Fatema; Sayed, M H Salim Ullah; Khan, Manzurul Haque; Aziz, Rashed; Hossain, Mohammed Zakir; Faruquee, M H

    2006-06-01

    This study was carried out among arsenic-exposed and non-exposed people of Bangladesh to assess and compare their cardiac status based on electrocardiographic (ECG) findings. For the purpose of the study, participants were included in three groups: arsenic-exposed persons with arsenicosis (arsenicosis group), arsenic-exposed persons without arsenicosis (non-arsenicosis group), and persons not exposed to arsenic (non-exposed group). Each group included 50 respondents. In this study, no significant difference in heart rate, rhythm, axis, and pulse rate interval was detected among the arsenicosis, non-arsenicosis and non-exposed groups. A significant difference in corrected QT interval between the arsenicosis and the non-exposed group (p<0.05) was observed. On the contrary, no statistically significant difference in corrected QT interval between the non-arsenicosis and the non-exposed group was found. Abnormal QRS complex was found among 14%, 8%, and 2% of the arsenicosis, non-arsenicosis, and non-exposed groups respectively. ECG findings, indicative of left ventricular hypertrophy, ischaemic heart disease, and right bundle branch block, were high among the arsenicosis group. Overall, abnormal ECG findings were high (58%) among the respondents of the arsenicosis group and were highly significant (p<0.001). The findings revealed that there was a significant association between ECG abnormalities and arsenic exposure.

  20. Modeling temperature and stress in rocks exposed to the sun

    NASA Astrophysics Data System (ADS)

    Hallet, B.; Mackenzie, P.; Shi, J.; Eppes, M. C.

    2012-12-01

    The potential contribution of solar-driven thermal cycling to the progressive breakdown of surface rocks on the Earth and other planets is recognized but under studied. To shed light on this contribution we have launched a collaborative study integrating modern instrumental and numerical approaches to define surface temperatures, stresses, strains, and microfracture activity in exposed boulders, and to shed light on the thermo-mechanical response of boulders to diurnal solar exposure. The instrumental portion of our study is conducted by M. Eppes and coworkers who have monitored the surface and environmental conditions of two ~30 cm dia. granite boulders (one in North Carolina, one in New Mexico) in the field for one and tow years, respectively. Each boulder is instrumented with 8 thermocouples, 8 strain gauges, a surface moisture sensor and 6 acoustic emission (AE) sensors to monitor microfracture activity continuously and to locate it within 2.5 cm. Herein, we focus on the numerical modeling. Using a commercially available finite element program, MSC.Marc®2008r1, we have developed an adaptable, realistic thermo-mechanical model to investigate quantitatively the temporal and spatial distributions of both temperature and stress throughout a boulder. The model accounts for the effects of latitude and season (length of day and the sun's path relative to the object), atmospheric damping (reduction of solar radiation when traveling through the Earth's atmosphere), radiative interaction between the boulder and its surrounding soil, secondary heat exchange of the rock with air, and transient heat conduction in both rock and soil. Using representative thermal and elastic rock properties, as well as realistic representations of the size, shape and orientation of a boulder instrumented in the field in North Carolina, the model is validated by comparison with direct measurements of temperature and strain on the surface of one boulder exposed to the sun. Using the validated

  1. Shorebird use of an exposed sandy beach in southern California

    NASA Astrophysics Data System (ADS)

    Hubbard, David M.; Dugan, Jenifer E.

    2003-10-01

    Frequent morning surveys of birds were conducted on 1 km of beach in southern California to investigate shorebird use of an exposed sandy beach. The overall mean abundance (98.6 individuals km -1), estimated biomass (9.6 kg km -1), and species richness (5.5 species km -1) of shorebirds observed were very high for a sandy beach in the temperate zone. Eight species, sanderling ( Calidris alba), semipalmated plover ( Charadrius semipalmatus), marbled godwit ( Limosa fedoa), black-bellied plover ( Pluvialis squatarola), western sandpiper ( Calidris mauri), willet ( Catoptrophorus semipalmatus), surfbird ( Aphriza virgata), and whimbrel ( Numenius phaeopus), occurred in overall mean abundances >1 bird km -1 and accounted for 97% of the abundance and biomass of shorebirds. Sanderlings were the most abundant shorebird every year (64% of individuals and 35% of the biomass). Different species of abundant shorebirds exhibited distinct patterns of use of beach habitat, including fall, spring, and winter peaks in abundance. Temporal variation in shorebird use on seasonal and interannual scales was associated with migration patterns, and also with habitat availability and condition. Seasonal variation in monthly mean abundance and estimated biomass of shorebirds varied over more than an order of magnitude and followed a similar pattern in each year, reaching maxima in the fall or winter (161-280 individuals km -1 and 15.4-23.9 kg km -1) and minima in May or June (3-11 individuals km -1 and 0.8-2.2 kg km -1). A minor peak in shorebird abundance and biomass coinciding with spring migration was observed in April of most years. The number of species of shorebirds observed in individual surveys ranged from 0 to 11 species km -1 and was positively and significantly correlated with abundance. Monthly mean species richness and the total species observed monthly followed similar seasonal patterns, ranging from annual maxima of 7.4-9.1 and 12-17 species km -1 between August and October

  2. Aquatic plants exposed to pharmaceuticals: effects and risks.

    PubMed

    Brain, Richard A; Hanson, Mark L; Solomon, Keith R; Brooks, Bryan W

    2008-01-01

    largely overlooked in the risk assessment process to date, which typically relies heavily on physiological and/or morphological endpoints for deriving toxicity data. However, a small number of studies have indicated that measuring the response of a pathway- or receptor-specific target in conjunction with a physiological endpoint with direct relatedness can yield sublethal responses that are two to three times more sensitive that the traditional gross morphological endpoints typically employed in risk assessment. The risk assessment for this review was based almost entirely on evaluations of gross morphological endpoints, which generally indicated that the risk pharmaceuticals pose to aquatic plants is generally low, with a few exceptions, particularly blue-green algae exposed to antibiotics, and both green and blue-green algae exposed to triclosan. It is critical to note, however, that the application of sublethal pathway or receptor-specific responses in risk assessment has largely been unconsidered, and future research is needed to elucidate whether evaluating the toxicity of pharmaceuticals using these endpoints provides a more sensitive, subtle, yet meaningful indication of toxicity than the traditional endpoints used in prospective and retrospective risk assessments for aquatic plants. PMID:18020304

  3. Exposing SAMOS Data and Vocabularies within the Semantic Web

    NASA Astrophysics Data System (ADS)

    Dockery, Nkemdirim; Elya, Jocelyn; Smith, Shawn

    2014-05-01

    As part of the Ocean Data Interoperability Platform (ODIP), we at the Center for Ocean-Atmospheric Prediction Studies (COAPS) will present the development process for the exposure of quality-controlled data and core vocabularies managed by the Shipboard Automated Meteorological Oceanographic System (SAMOS) initiative using Semantic Web technologies. Participants in the SAMOS initiative collect continuous navigational (position, course, heading, speed), meteorological (winds, pressure, temperature, humidity, radiation), and near-surface oceanographic (sea temperature, salinity) parameters while at sea. One-minute interval observations are packaged and transmitted back to COAPS via daily emails, where they undergo standardized formatting and quality control. The authors will present methods used to expose these daily datasets. The Semantic Web, a vision of the World Wide Web Consortium, focuses on extending the principles of the web from connecting documents to connecting data. The creation of a web of Linked Data that can be used across different applications in a machine-readable way is the ultimate goal. The Resource Description Framework (RDF) is the standard language and format used in the Semantic Web. RDF pages may be queried using the SPARQL Protocol and RDF Query Language (SPARQL). The authors will showcase the development of RDF resources that map SAMOS vocabularies to internationally served vocabularies such as those found in the Natural Environment Research Council (NERC) Vocabulary Server. Each individual SAMOS vocabulary term (data parameter and quality control flag) will be described in an RDF resource page. These RDF resources will define each SAMOS vocabulary term and provide a link to the mapped vocabulary term (or multiple terms) served externally. Along with enhanced retrieval by parameter, time, and location, we will be able to add additional parameters with the confidence that they follow an international standard. The production of RDF

  4. Coagulation markers in healthy human subjects exposed to diesel exhaust

    PubMed Central

    Carlsten, Chris; Kaufman, Joel D; Peretz, Alon; Trenga, Carol A; Sheppard, Lianne; Sullivan, Jeffrey H

    2008-01-01

    Background Ambient particulate matter (PM) is associated with cardiovascular morbidity and mortality. It has been proposed that PM induces a pro-thrombotic process, increasing the risk of cardiovascular events, with some support from epidemiological and laboratory-based models. Diesel exhaust is a major contributor to urban PM, and we conducted a controlled human exposure of diesel exhaust in healthy subjects. Objective To evaluate diesel exhaust exposure effects on fibrinolytic burden (D-dimer), platelet number, and endothelial injury (von Willebrand’s factor, VWF), inhibition of the fibrinolytic pathway (plasminogen activator inhibitor-1 [PAI-1]), and inflammation (C-reactive protein, CRP). Materials and Methods Randomized, crossover, double-blinded design, with 13 healthy participants exposed on three different days (≥ 2 weeks washout) to diesel exhaust at 0 (filtered air), 100μg PM2.5/m3 and 200μg PM2.5/m3. We assessed diesel exhaust-associated changes in D-dimer, VWF, PAI-1 and platelets at 3, 6 and 22 hours, and CRP at 22 hours, after exposure initiation. Results Significant changes did not occur in any primary endpoints. Among secondary endpoints, diesel exhaust (200μg PM2.5/m3) effect on PAI-1 levels at 22 hours was of borderline significance, with a 1.32-fold decrease after exposure to diesel exhaust (200μg PM2.5/m3), relative to filtered air (CI 1.00 to 1.54). Diurnal patterns in D-dimer and PAI-1 were observed. Conclusions In healthy individuals, exposure to 200μg PM2.5/m3 diesel exhaust did not affect primary pro-thrombotic endpoints. Thus, these data do not support a diesel exhaust-induced pro-thrombotic phenomenon. Replication of these studies should be carried out to ascertain whether or not they inform our mechanistic understanding of air pollution’s cardiovascular effects. PMID:17321570

  5. Polymorphic trial in oxidative damage of arsenic exposed Vietnamese.

    PubMed

    Fujihara, Junko; Soejima, Mikiko; Yasuda, Toshihiro; Koda, Yoshiro; Kunito, Takashi; Iwata, Hisato; Tanabe, Shinsuke; Takeshita, Haruo

    2011-10-15

    Arsenic causes DNA damage and changes the cellular capacity for DNA repair. Genes in the base excision repair (BER) pathway influence the generation and repair of oxidative lesions. Single nucleotide polymorphisms (SNPs) in human 8-oxoguanine DNA glycosylase (hOGG1) Ser326Cys; apurinic/apyrimidinic endonuclease (APE1) Asp148Glu; X-ray and repair and cross-complementing group 1 (XRCC1) Arg280His and Arg399Gln in the BER genes were analyzed, and the relationship between these 4 SNPs and the urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations of 100 Vietnamese population exposed to arsenic was investigated. Individuals with hOGG1 326Cys/Cys showed significantly higher urinary 8-OHdG concentrations than did those with 326 Ser/Cys and Ser/Ser. As for APE1 Asp148Glu, heterozygous subjects showed significantly higher urinary 8-OHdG concentrations than did those homozygous for Asp/Asp. Moreover, global ethnic comparison of the allelic frequencies of the 4SNPs was performed in 10 population and previous reported data. The mutant allele frequencies of hOGG1 Ser326Cys in the Asian populations were higher than those in the African and Caucasian populations. As for APE1 Asp148Glu, Caucasians showed higher mutant frequencies than those shown by African and Asian populations. Among Asian populations, the Bangladeshi population showed relatively higher mutant allele frequencies of the APE1 Asp148Glu polymorphism. This study is the first to demonstrate the existence of genetic heterogeneity in a worldwide distribution of SNPs (hOGG1 Ser326Cys, APE1 Asp148Glu, XRCC1 Arg280His, and XRCC1 Arg399Gln) in the BER genes.

  6. Small airways function of silica-exposed workers.

    PubMed

    Chia, K S; Ng, T P; Jeyaratnam, J

    1992-01-01

    Small airways obstruction may be present for many years before chronic airway obstruction becomes evident. Several spirometric indices, especially flow rates at low lung volumes, may reflect the status of small airways. Time domain indices, by using moments analysis of the volume time spirogram, have also been shown to be sensitive indicators of small airways obstruction. In this study, we have applied the various spirometric indices as well as time domain indices to a group of granite quarry workers without radiographic evidence of silicosis or physiological evidence of obstruction to the larger airways. The aim was to evaluate small airways function in relation to dust exposure in subjects with normal ratio of the forced expiratory volume in one second to the forced vital capacity (FEV1/FVC) and normal FVC. The volume-time spirograms of 140 quarry workers were digitized using an electronic digitizer connected to a microcomputer where flow and time domain indices were computed. The workers were divided into three exposure groups based on their occupational history. With adjustment for age, height, and smoking status, all the time domain indices showed significant small airways obstruction with increasing dust exposure. Smokers had greater degree of airways obstruction than the non-smokers, with a similar trend of increase in small airways obstruction in relation to higher exposure. Our present study suggests that small airways obstruction is present among silica exposed workers in the absence of radiological evidence of silicosis and large airways obstruction. There was also evidence of increasing small airways obstruction in higher dust exposure group. Our study also suggests that time domain indices are more sensitive to small airways obstruction.

  7. Toxicokinetics of captan and folpet biomarkers in orally exposed volunteers.

    PubMed

    Berthet, Aurélie; Bouchard, Michèle; Danuser, Brigitta

    2012-03-01

    The time courses of key biomarkers of exposure to captan and folpet was assessed in accessible biological matrices of orally exposed volunteers. Ten volunteers ingested 1  mg kg(-1) body weight of captan or folpet. Blood samples were withdrawn at fixed time periods over the 72  h following ingestion and complete urine voids were collected over 96  h post-dosing. The tetrahydrophthalimide (THPI) metabolite of captan along with the phthalimide (PI) and phthalic acid metabolites of folpet were then quantified in these samples. Plasma levels of THPI and PI increased progressively after ingestion, reaching peak values ~10 and 6  h post-dosing, respectively; subsequent elimination phase appeared monophasic with a mean elimination half-life (t(½) ) of 15.7 and 31.5  h, respectively. In urine, elimination rate time courses of PI and phthalic acid evolved in parallel, with respective t(½) of 27.3 and 27.6  h; relatively faster elimination was found for THPI, with mean t(½) of 11.7  h. However, phthalic acid was present in urine in 1000-fold higher amounts than PI. In the 96  h period post-treatment, on average 25% of folpet dose was excreted in urine as phthalic acid as compared with only 0.02% as PI. The corresponding value for THPI was 3.5%. Overall, THPI and PI appear as interesting biomarkers of recent exposure, with relatively short half-lives; their sensitivity to assess exposure in field studies should be further verified. Although not a metabolite specific to folpet, the concomitant use of phthalic acid as a major biomarker of exposure to folpet should also be considered.

  8. Respiratory Kinetics of Marine Bacteria Exposed to Decreasing Oxygen Concentrations

    PubMed Central

    Gong, Xianzhe; Garcia-Robledo, Emilio; Schramm, Andreas

    2015-01-01

    During aerobic respiration, microorganisms consume oxygen (O2) through the use of different types of terminal oxidases which have a wide range of affinities for O2. The Km values for O2 of these enzymes have been determined to be in the range of 3 to 200 nmol liter−1. In this study, we examined the time course of development of aerobic respiratory kinetics of four marine bacterial species (Dinoroseobacter shibae, Roseobacter denitrificans, Idiomarina loihiensis, and Marinobacter daepoensis) during exposure to decreasing O2 concentrations. The genomes of all four species have genes for both high-affinity and low-affinity terminal oxidases. The respiration rate of the bacteria was measured by the use of extremely sensitive optical trace O2 sensors (range, 1 to 1,000 nmol liter−1). Three of the four isolates exhibited apparent Km values of 30 to 60 nmol liter−1 when exposed to submicromolar O2 concentrations, but a decrease to values below 10 nmol liter−1 was observed when the respiration rate per cell was lowered and the cell size was decreased due to starvation. The fourth isolate did not reach a low respiration rate per cell during starvation and exhibited apparent Km values of about 20 nmol liter−1 throughout the experiment. The results clearly demonstrate not only that enzyme kinetics may limit O2 uptake but also that even individual cells may be diffusion limited and that this diffusion limitation is the most pronounced at high respiration rates. A decrease in cell size by starvation, due to limiting organic carbon, and thereby more efficient diffusion uptake may also contribute to lower apparent Km values. PMID:26682857

  9. Helium segregation on surfaces of plasma-exposed tungsten.

    PubMed

    Maroudas, Dimitrios; Blondel, Sophie; Hu, Lin; Hammond, Karl D; Wirth, Brian D

    2016-02-17

    We report a hierarchical multi-scale modeling study of implanted helium segregation on surfaces of tungsten, considered as a plasma facing component in nuclear fusion reactors. We employ a hierarchy of atomic-scale simulations based on a reliable interatomic interaction potential, including molecular-statics simulations to understand the origin of helium surface segregation, targeted molecular-dynamics (MD) simulations of near-surface cluster reactions, and large-scale MD simulations of implanted helium evolution in plasma-exposed tungsten. We find that small, mobile He n (1⩽  n  ⩽  7) clusters in the near-surface region are attracted to the surface due to an elastic interaction force that provides the thermodynamic driving force for surface segregation. This elastic interaction force induces drift fluxes of these mobile He n clusters, which increase substantially as the migrating clusters approach the surface, facilitating helium segregation on the surface. Moreover, the clusters' drift toward the surface enables cluster reactions, most importantly trap mutation, in the near-surface region at rates much higher than in the bulk material. These near-surface cluster dynamics have significant effects on the surface morphology, near-surface defect structures, and the amount of helium retained in the material upon plasma exposure. We integrate the findings of such atomic-scale simulations into a properly parameterized and validated spatially dependent, continuum-scale reaction-diffusion cluster dynamics model, capable of predicting implanted helium evolution, surface segregation, and its near-surface effects in tungsten. This cluster-dynamics model sets the stage for development of fully atomistically informed coarse-grained models for computationally efficient simulation predictions of helium surface segregation, as well as helium retention and surface morphological evolution, toward optimal design of plasma facing components. PMID:26794828

  10. Helium segregation on surfaces of plasma-exposed tungsten

    DOE PAGESBeta

    Maroudas, Dimitrios; Blondel, Sophie; Hu, Lin; Hammond, Karl D.; Wirth, Brian D.

    2016-01-21

    Here we report a hierarchical multi-scale modeling study of implanted helium segregation on surfaces of tungsten, considered as a plasma facing component in nuclear fusion reactors. We employ a hierarchy of atomic-scale simulations based on a reliable interatomic interaction potential, including molecular-statics simulations to understand the origin of helium surface segregation, targeted molecular-dynamics (MD) simulations of near-surface cluster reactions, and large-scale MD simulations of implanted helium evolution in plasma-exposed tungsten. We find that small, mobile He-n (1 <= n <= 7) clusters in the near-surface region are attracted to the surface due to an elastic interaction force that provides themore » thermodynamic driving force for surface segregation. Elastic interaction force induces drift fluxes of these mobile Hen clusters, which increase substantially as the migrating clusters approach the surface, facilitating helium segregation on the surface. Moreover, the clusters' drift toward the surface enables cluster reactions, most importantly trap mutation, in the near-surface region at rates much higher than in the bulk material. Moreover, these near-surface cluster dynamics have significant effects on the surface morphology, near-surface defect structures, and the amount of helium retained in the material upon plasma exposure. We integrate the findings of such atomic-scale simulations into a properly parameterized and validated spatially dependent, continuum-scale reaction-diffusion cluster dynamics model, capable of predicting implanted helium evolution, surface segregation, and its near-surface effects in tungsten. This cluster-dynamics model sets the stage for development of fully atomistically informed coarse-grained models for computationally efficient simulation predictions of helium surface segregation, as well as helium retention and surface morphological evolution, toward optimal design of plasma facing components.« less

  11. Magnetic behavioural change of silane exposed graphene nanoflakes

    SciTech Connect

    Ray, Sekhar C.; Mishra, D. K.; Strydom, A. M.; Papakonstantinou, P.

    2015-09-21

    The electronic structures and magnetic properties of graphene nanoflakes (GNFs) exposed to an organo-silane precursor [tetra-methyl-silane, Si(CH{sub 3}){sub 4}] were studied using atomic force microscopy, electron field emission (EFE), x-ray photoelectron spectroscopy (XPS), and magnetization. The result of XPS indicates that silyl radical based strong covalent bonds were formed in GNFs, which induced local structural relaxations and enhanced sp{sup 3} hybridization. The EFE measurements show an increase in the turn-on electric field from 9.8 V/μm for pure GNFs to 26.3 V/μm for GNFs:Si having highest Si/(Si + C) ratio ( ≅ 0.35) that also suggests an enhancement of the non-metallic sp{sup 3} bonding in the GNFs matrix. Magnetic studies show that the saturation magnetization (Ms) is decreased from 172.53 × 10{sup −6} emu/g for pure GNFs to 13.00 × 10{sup −6} emu/g for GNFs:Si with the highest Si/(Si + C) ratio 0.35, but on the other side, the coercivity (Hc) increases from 66 to 149 Oe due to conversion of sp{sup 2} → sp{sup 3}-hybridization along with the formation of SiC and Si-O bonding in GNFs. The decrease in saturation magnetization and increase in coercivity (Hc) in GNFs on Si-functionalization are another routes to tailor the magnetic properties of graphene materials for magnetic device applications.

  12. Cohort mortality study of workers exposed to perfluorooctanoic acid.

    PubMed

    Steenland, Kyle; Woskie, Susan

    2012-11-15

    Perfluorooctanoic acid (PFOA) is persistent in the human body; the general population has serum levels of approximately 4 ng/mL. It causes tumors of the liver, pancreas, and testicles in rodents. The authors studied the mortality of 5,791 workers exposed to PFOA at a DuPont chemical plant in West Virginia, using a newly developed job exposure matrix based on serum data for 1,308 workers from 1979-2004. The estimated average serum PFOA level was 350 ng/mL. The authors used 2 referent groups: other DuPont workers in the region and the US population. In comparison with other DuPont workers, cause-specific mortality was elevated for mesothelioma (standardized mortality ratio (SMR) = 2.85, 95% confidence interval (CI): 1.05, 6.20), diabetes mellitus (SMR = 1.90, 95% CI: 1.35, 2.61), and chronic renal disease (SMR = 3.11, 95% CI: 1.66, 5.32). Significant positive exposure-response trends occurred for both malignant and nonmalignant renal disease (12 and 13 deaths, respectively). PFOA is concentrated in the kidneys of rodents, and there are prior findings of elevated kidney cancer in this cohort. Multiple-cause mortality analyses tended to support the results of underlying-cause analyses. No exposure-response trend was seen for diabetes or heart disease mortality. In conclusion, the authors found evidence of positive exposure-response trends for malignant and nonmalignant renal disease. These results were limited by small numbers and restriction to mortality data, which are of limited relevance for several nonfatal outcomes of a priori interest.

  13. Ethnic minority health in Vietnam: a review exposing horizontal inequity

    PubMed Central

    Målqvist, Mats; Hoa, Dinh Thi Phuong; Liem, Nguyen Thanh; Thorson, Anna; Thomsen, Sarah

    2013-01-01

    Background Equity in health is a pressing concern and reaching disadvantaged populations is necessary to close the inequity gap. To date, the discourse has predominately focussed on reaching the poor. At the same time and in addition to wealth, other structural determinants that influence health outcomes exist, one of which is ethnicity. Inequities based on group belongings are recognised as ‘horizontal’, as opposed to the more commonly used notion of ‘vertical’ inequity based on individual characteristics. Objective The aim of the present review is to highlight ethnicity as a source of horizontal inequity in health and to expose mechanisms that cause and maintain this inequity in Vietnam. Design Through a systematic search of available academic and grey literature, 49 publications were selected for review. Information was extracted on: a) quantitative measures of health inequities based on ethnicity and b) qualitative descriptions explaining potential reasons for ethnicity-based health inequities. Results Five main areas were identified: health-care-seeking and utilization, maternal and child health, nutrition, infectious diseases, and oral health and hygiene. Evidence suggests the presence of severe health inequity in health along ethnic lines in all these areas. Research evidence also offers explanations derived from both external and internal group dynamics to this inequity. It is reported that government policies and programs appear to be lacking in culturally adaptation and sensitivity, and examples of bad attitudes and discrimination from health staff toward minority persons were identified. In addition, traditions and patriarchal structures within ethnic minority groups were seen to contribute to the maintenance of harmful health behaviors within these groups. Conclusion Better understandings of the scope and pathways of horizontal inequities are required to address ethnic inequities in health. Awareness of ethnicity as a determinant of health, not

  14. Immunotoxicity Monitoring in a Population Exposed to Polychlorinated Biphenyls.

    PubMed

    Haase, Hajo; Fahlenkamp, Astrid; Schettgen, Thomas; Esser, Andre; Gube, Monika; Ziegler, Patrick; Kraus, Thomas; Rink, Lothar

    2016-03-08

    The relationship between polychlorinated biphenyl (PCB) burden and several indicators of immune function was investigated as part of the HELPcB (Health Effects in High-Level Exposure to PCB) program, offering bio-monitoring to workers, relatives, and neighbors exposed to PCBs by a German transformers and capacitors recycling company. The present retrospective observational study evaluates the correlation of plasma levels of total PCBs, five indicator congeners (28, 101, 138, 153, 180), and seven dioxin-like congeners (105, 114, 118, 156, 157, 167, 189) with several parameters of immune function. The cross-sectional study was performed immediately after the end of exposure (258 subjects), and one (218 subjects), and two (177 subjects) years later. At the first time point, measurements showed significant positive correlation between congeners with low to medium chlorination and the relative proportion of CD19 positive B-cells among lymphocytes, as well as a negative correlation of PCB114 with serum IgM, and of PCB 28 with suppressor T-cell and NK-cell numbers. Congeners with a high degree of chlorination, in particular PCB157 and 189, were positively associated with expression of the activation marker CD25 on T-cells in the cohort of the second time point. No associations between PCB levels and IFN-y production by T-cells and killing by NK-cells were found. In conclusion, there were several effects on the cellular composition of adaptive immunity, affecting both T- and B-cells. However, the values were not generally outside the reference ranges for healthy adult individuals and did not indicate overt functional immunodeficiency, even in subjects with the uppermost PCB burden.

  15. Cloning assay thresholds on cells exposed to ultrafast laser pulses

    NASA Astrophysics Data System (ADS)

    Koenig, Karsten; Riemann, Iris; Fischer, Peter; Becker, Thomas P.; Oehring, Hartmut; Halbhuber, Karl-Juergen

    1999-06-01

    The influence of the peak power, laser wavelength and the pulse duration of near infrared (NIR) ultrashort laser pulses on the reproduction behavior of Chinese hamster ovary (CHO) cells has been studied. In particular we determined the cloning efficiency of single cell pairs after exposure to ultrashort laser pulses with an intensity in the range of GW/cm2 and TW/cm2. A total of more than 3500 non- labeled cells were exposed to a highly focused scanning beam of a multiphoton laser microscope with 60 microsecond pixel dwell time per scan. The beam was provided by a tunable argon ion laser pumped mode-locked 76 MHz Titanium:Sapphire laser as well as by a compact solid-state laser based system (Vitesse) at a fixed wavelength of 800 nm. Pulse duration (tau) was varied in the range of 100 fs to 4 ps by out-of-cavity pulse- stretching units consisting of SF14 prisms and blazed gratings. Within an optical (laser power) window CHO cells could be scanned for hours without severe impact on reproduction behavior, morphology and vitality. Ultrastructural studies reveal that mitochondria are the major targets of intense destructive laser pulses. Above certain laser power P thresholds, CHO cells started to delay or failed to undergo cell division and, in part, to develop uncontrolled cell growth (giant cell formation). The damage followed a P2/(tau) relation which is typical for a two-photon excitation process. Therefore, cell damage was found to be more pronounced at shorter pulses. Due to the same P2/(tau) relation for the efficiency of fluorescence excitation, two- photon microscopy of living cells does not require extremely short femtosecond laser pulses nor pulse compression units. Picosecond as well as femtosecond layers can be used as efficient light sources in safe two photon fluorescence microscopy. Only in three photon fluorescence microscopy, femtosecond laser pulses are advantageous over picosecond pulses.

  16. Cloning assay thresholds on cells exposed to ultrafast laser pulses

    NASA Astrophysics Data System (ADS)

    Koenig, Karsten; Riemann, Iris; Fischer, Peter; Becker, Thomas P.; Oehring, Hartmut; Halbhuber, Karl-Juergen

    1999-06-01

    The influence of the peak power, laser wavelength and the pulse duration of near infrared ultrashort laser pulses on the reproduction behavior of Chinese hamster ovary (CHO) cells has been studied. In particular, we determined the cloning efficiency of single cell pairs after exposure to ultrashort laser pulses with an intensity in the range of GW/cm2 and TW/cm2. A total of more than 3500 non- labeled cells were exposed to a highly focused scanning beam of a multiphoton laser microscope with 60 microsecond(s) pixel dwell time per scan. The beam was provided by a tunable argon ion laser pumped mode-locked 76 MHz Titanium:Sapphire laser as well as by a compact solid-state laser based system (Vitesse) at a fixed wavelength of 800 nm. Pulse duration (tau) was varied in the range of 100 fs to 4 ps by out-of- cavity pulse-stretching units consisting of SF14 prisms and blazed gratings. Within an optical (laser power) window CHO cells could be scanned for hours without severe impact on reproduction behavior, morphology and vitality. Ultrastructural studies reveal that mitochondria are the major targets of intense destructive laser pulses. Above certain laser power P thresholds, CHO cells started to delay or failed to undergo cell division and, in part, to develop uncontrolled cell growth (giant cell formation). The damage followed a P2/(tau) relation which is typical for a two- photon excitation process. Therefore, cell damage was found to be more pronounced at shorter pulses. Due to the same P2/(tau) relation for the efficiency of fluorescence excitation, two-photon microscopy of living cells does not require extremely short femtosecond laser pulses nor pulse compression units. Picosecond as well as femtosecond lasers can be used as efficient light sources in safe two photon fluorescence microscopy. Only in three photon fluorescence microscopy, femtosecond laser pulses are advantageous over picosecond pulses.

  17. Multifactorial aetiology of lung cancer among silica-exposed workers.

    PubMed

    Cocco, P

    2001-09-01

    In 1997, the International Agency for Research on Cancer (IARC) upgraded its evaluation of crystalline silica to a Group 1 human carcinogen. Criticism against such decision is based on the lack of consistency in experimental results across animal species, violation of an important principle for causality, such as the replication of findings under different circumstances of exposure, and the lack of a clear dose-response curve. The most recent epidemiological literature on the silica-silicosis-lung cancer link replicates the inconsistent findings that have been characterising 50 years of scientific debate in the occupational arena. Exposure circumstances capable of modifying the silica-lung cancer association include chronic bronchitis, composition of the dust mixing, particularly concerning co-occurrence of other known or probable lung carcinogens, total respirable dust, concentration of silica in respirable dust, type of crystalline silica and particle surface characteristics. The hypothesis of a silicosis-mediated pathway points toward an unspecific mechanism shared with other fibrotic conditions, for which silica might be just one of the triggers. In envisaging a multivariate multistep model of lung cancer among silica-exposed workers, silica might be considered as a "passive components of the sufficient cause", i.e., one of the associated risk factors, concurrent or subsequent to the "active component(s) of the sufficient cause" (including, for instance, smoking, asbestos, radon-daughters, arsenic, hexavalent chromium, nickel, polycyclic aromatic hydrocarbons (PAH), and diesel exhausts among the external risk factors; and DNA repair enzymes polymorphism and spontaneous inactivation of tumour suppressor genes among the internal risk factors), which adds up in modulating the tumoral development in not easily predictable directions. If silica acts as a human lung carcinogen depending on certain occupational exposure circumstances, perhaps those circumstances and

  18. Helium segregation on surfaces of plasma-exposed tungsten.

    PubMed

    Maroudas, Dimitrios; Blondel, Sophie; Hu, Lin; Hammond, Karl D; Wirth, Brian D

    2016-02-17

    We report a hierarchical multi-scale modeling study of implanted helium segregation on surfaces of tungsten, considered as a plasma facing component in nuclear fusion reactors. We employ a hierarchy of atomic-scale simulations based on a reliable interatomic interaction potential, including molecular-statics simulations to understand the origin of helium surface segregation, targeted molecular-dynamics (MD) simulations of near-surface cluster reactions, and large-scale MD simulations of implanted helium evolution in plasma-exposed tungsten. We find that small, mobile He n (1⩽  n  ⩽  7) clusters in the near-surface region are attracted to the surface due to an elastic interaction force that provides the thermodynamic driving force for surface segregation. This elastic interaction force induces drift fluxes of these mobile He n clusters, which increase substantially as the migrating clusters approach the surface, facilitating helium segregation on the surface. Moreover, the clusters' drift toward the surface enables cluster reactions, most importantly trap mutation, in the near-surface region at rates much higher than in the bulk material. These near-surface cluster dynamics have significant effects on the surface morphology, near-surface defect structures, and the amount of helium retained in the material upon plasma exposure. We integrate the findings of such atomic-scale simulations into a properly parameterized and validated spatially dependent, continuum-scale reaction-diffusion cluster dynamics model, capable of predicting implanted helium evolution, surface segregation, and its near-surface effects in tungsten. This cluster-dynamics model sets the stage for development of fully atomistically informed coarse-grained models for computationally efficient simulation predictions of helium surface segregation, as well as helium retention and surface morphological evolution, toward optimal design of plasma facing components.

  19. Apoptosis may involve in prenatally heroin exposed neurobehavioral teratogenicity?

    PubMed

    Ying, Wang; Jang, Farhan Fateh; Teng, Chen; Tai-Zhen, Han

    2009-12-01

    Heroin abuse during pregnancy is a serious problem worldwide. Among all the illicit drugs, heroin is known as the most commonly abused opioid in the United States and China. Most women addicts are of child-bearing age. Heroin abuse during pregnancy, together with related factors like poor nutrition and inadequate maternal care, has been associated with adverse consequences including developmental delay of the offspring and their neurobehavioral teratogenicity. Researchers have done a lot of work to focus mainly on the variation of neurobehavior and its related factors such as the changes of neurotransmitters, receptors and involvement of the limited brain regions, but no one clearly and comprehensively explain the possible mechanism that may participate in the neurobehavioral teratogenicity induced by prenatal heroin exposure. Studies on animals have shown that heroin is a common neuroteratogen which can produce neurobehavioral defects. There must be some underlying mechanisms in the central nervous system which may take part in these defects. We hypothesized that the alterations in developmental apoptosis during embryogenesis could be one of the possible mechanisms which can cause neurobehavioral teratogenicity in prenatally heroin exposed offspring. Heroin is believed to pass through the placenta and blood-brain barrier much more rapidly than morphine due to the presence of acetyl groups and affects the developing brain. So far, it still remains obscure that whether the apoptosis in a particular brain region induced by heroin exposure in uterus is involved in neurobehavioral teratogenicity. Our hypothesis perhaps provides a more logical and possible explanation of the mechanism responsible for neurobehavioral teratogenicity caused by the prenatal heroin exposure during embryonic development. It can help to develop appropriate experimental animal models to understand the detailed mechanisms involved.

  20. Limited Transcriptional Responses of Rickettsia rickettsii Exposed to Environmental Stimuli

    PubMed Central

    Ellison, Damon W.; Clark, Tina R.; Sturdevant, Daniel E.; Virtaneva, Kimmo; Hackstadt, Ted

    2009-01-01

    Rickettsiae are strict obligate intracellular pathogens that alternate between arthropod and mammalian hosts in a zoonotic cycle. Typically, pathogenic bacteria that cycle between environmental sources and mammalian hosts adapt to the respective environments by coordinately regulating gene expression such that genes essential for survival and virulence are expressed only upon infection of mammals. Temperature is a common environmental signal for upregulation of virulence gene expression although other factors may also play a role. We examined the transcriptional responses of Rickettsia rickettsii, the agent of Rocky Mountain spotted fever, to a variety of environmental signals expected to be encountered during its life cycle. R. rickettsii exposed to differences in growth temperature (25°C vs. 37°C), iron limitation, and host cell species displayed nominal changes in gene expression under any of these conditions with only 0, 5, or 7 genes, respectively, changing more than 3-fold in expression levels. R. rickettsii is not totally devoid of ability to respond to temperature shifts as cold shock (37°C vs. 4°C) induced a change greater than 3-fold in up to 56 genes. Rickettsiae continuously occupy a relatively stable environment which is the cytosol of eukaryotic cells. Because of their obligate intracellular character, rickettsiae are believed to be undergoing reductive evolution to a minimal genome. We propose that their relatively constant environmental niche has led to a minimal requirement for R. rickettsii to respond to environmental changes with a consequent deletion of non-essential transcriptional response regulators. A minimal number of predicted transcriptional regulators in the R. rickettsii genome is consistent with this hypothesis. PMID:19440298

  1. Polyamines and polyamine biosynthesis in cells exposed to hyperthermia

    SciTech Connect

    Gerner, E.W.; Stickney, D.G.; Herman, T.S.; Fuller, D.J.

    1983-02-01

    The issue of how polyamines act to sensitize cultured cells to the lethal effects of hyperthermia was investigated using Chinese hamster cells which were induced to express thermotolerance. Intracellular levels of these naturally occurring polycations were manipulated in certain situations by treating whole cells with methylglyoxal bis-(guanylhydrazone), an inhibitor of the S-adenosyl-L-methionine decarboxylases. Exogenous spermine as low as 100 ..mu..M in the culture media dramatically sensitized cells expressing thermotolerance to the lethal effects of subsequent 42/sup 0/C exposures. When thermotolerance was differentially induced in cultures exposed to 42.4/sup 0/C by varying the rate of heating from 37 to 42.4/sup 0/C, the most resistant cells and the highest levels of intracellular spermidine and spermine. This finding was explainable in part by the observation that the putrescine-dependent S-adenosyl-L-methionine decarboxylase activity was minimally affected in cells expressng the greatest degree of thermotolerance. When this enzyme activity was inhibited by drug, lowered intracellular polyamine levels did not correspond with subsequent survival responses to heat. Interestingly, cultures treated with methylglyoxal bis-(guanylhydrazone) 24 hr previous to heat exposure showed a reduced capacity to express rate of heating-induced thermotolerance. Together, these results demonstrate that the polyamines, especially spermidine and spermine, enhance hyperthermia-induced cell killing by some mechanism involving the plasma membrane. Further, our data suggest that methylglyoxal bis-(guanylhydrazone) can act to affect thermal responses by a mechanism(s) other than modification of intracellular polyamine levels.

  2. Immunotoxicity Monitoring in a Population Exposed to Polychlorinated Biphenyls.

    PubMed

    Haase, Hajo; Fahlenkamp, Astrid; Schettgen, Thomas; Esser, Andre; Gube, Monika; Ziegler, Patrick; Kraus, Thomas; Rink, Lothar

    2016-03-01

    The relationship between polychlorinated biphenyl (PCB) burden and several indicators of immune function was investigated as part of the HELPcB (Health Effects in High-Level Exposure to PCB) program, offering bio-monitoring to workers, relatives, and neighbors exposed to PCBs by a German transformers and capacitors recycling company. The present retrospective observational study evaluates the correlation of plasma levels of total PCBs, five indicator congeners (28, 101, 138, 153, 180), and seven dioxin-like congeners (105, 114, 118, 156, 157, 167, 189) with several parameters of immune function. The cross-sectional study was performed immediately after the end of exposure (258 subjects), and one (218 subjects), and two (177 subjects) years later. At the first time point, measurements showed significant positive correlation between congeners with low to medium chlorination and the relative proportion of CD19 positive B-cells among lymphocytes, as well as a negative correlation of PCB114 with serum IgM, and of PCB 28 with suppressor T-cell and NK-cell numbers. Congeners with a high degree of chlorination, in particular PCB157 and 189, were positively associated with expression of the activation marker CD25 on T-cells in the cohort of the second time point. No associations between PCB levels and IFN-y production by T-cells and killing by NK-cells were found. In conclusion, there were several effects on the cellular composition of adaptive immunity, affecting both T- and B-cells. However, the values were not generally outside the reference ranges for healthy adult individuals and did not indicate overt functional immunodeficiency, even in subjects with the uppermost PCB burden. PMID:27005643

  3. Changes in menarcheal age in girls exposed to war conditions.

    PubMed

    Prebeg, Zivka; Bralic, Irena

    2000-07-01

    The purpose of this study was to assess changes in mean menarcheal age of girls in the city of Sibenik in the period from mid-1980s to the mid-1990s. Sibenik is a Dalmatian town which was exposed to hard war conditions in 1991-1995. Menarcheal status of Sibenik girls was surveyed three times, in 1981, 1985, and 1996, and included 720, 1,207, and 1,680 girls, respectively, ages 9.5-16.5 years. Mean menarcheal age was estimated by the status quo method and application of probit analysis. Results show a slight decrease in menarcheal age from 1981 to 1985 (from 12.97 +/- 0.06 years to 12.87 +/- 0.05), and then a significant increase from 12.87 +/- 0.05 years in 1985 to 13.13 +/- 0.10 years in 1996. The increase in mean menarcheal age occurred in all socioeconomic groups based on parental occupation and number of siblings. In the group of girls whose homes were damaged during war, menarche occurred at an average of 13.53 +/- 0.14 years, while those who lost a family member experienced menarche at an older mean age, 13.76 +/- 0.27 years. However, when the girls who experienced personal tragedies were excluded the onset of menarche was still later than in girls surveyed in the earlier periods. The results suggest that the general reversal in the secular trend of menarcheal age in Sibenik girls can be attributed to persistent psychological pressures and uncertainties associated with conditions of war. Am. J. Hum. Biol. 12:503-508, 2000. Copyright 2000 Wiley-Liss, Inc. PMID:11534042

  4. Metabolomic characterization of laborers exposed to welding fumes.

    PubMed

    Wang, Kuo-Ching; Kuo, Ching-Hua; Tian, Tze-Feng; Tsai, Mong-Hsun; Chiung, Yin-Mei; Hsiech, Chun-Ming; Tsai, Sung-Jeng; Wang, San-Yuan; Tsai, Dong-Ming; Huang, Chiang-Ching; Tseng, Y Jane

    2012-03-19

    The complex composition of welding fumes, multiplicity of molecular targets, diverse cellular effects, and lifestyles associated with laborers vastly complicate the assessment of welding fume exposure. The urinary metabolomic profiles of 35 male welders and 16 male office workers at a Taiwanese shipyard were characterized via (1)H NMR spectroscopy and pattern recognition methods. Blood samples for the same 51 individuals were also collected, and the expression levels of the cytokines and other inflammatory markers were examined. This study dichotomized the welding exposure variable into high (welders) versus low (office workers) exposures to examine the differences of continuous outcome markers-metabolites and inflammatory markers-between the two groups. Fume particle assessments showed that welders were exposed to different concentrations of chromium, nickel, and manganese particles. Multivariate statistical analysis of urinary metabolomic patterns showed higher levels of glycine, taurine, betaine/TMAO, serine, S-sulfocysteine, hippurate, gluconate, creatinine, and acetone and lower levels of creatine among welders, while only TNF-α was significantly associated with welding fume exposure among all cytokines and other inflammatory markers measured. Of the identified metabolites, the higher levels of glycine, taurine, and betaine among welders were suspected to play some roles in modulating inflammatory and oxidative tissue injury processes. In this metabolomics experiment, we also discovered that the association of the identified metabolites with welding exposure was confounded by smoking, but not with drinking, which is a finding consistent with known modified response of inflammatory markers among smokers. Our results correspond with prior studies that utilized nonmetabolomic analytical techniques and suggest that the metabolomic profiling is an efficient method to characterize the overall effect of welding fume exposure and other confounders.

  5. Nickel and blood counts in workers exposed to urban stressors.

    PubMed

    Rosati, Maria Valeria; Casale, Teodorico; Ciarrocca, Manuela; Weiderpass, Elisabete; Capozzella, Assunta; Schifano, Maria Pia; Tomei, Francesco; Nieto, Hector Alberto; Marrocco, Mariasilvia; Tomei, Gianfranco; Caciari, Tiziana; Sancini, Angela

    2016-06-01

    Nickel (Ni) and Ni compounds are widely present in the urban air. The purpose of this study is to estimate exposure of individuals to Ni and the correlation between this exposure and the values of blood counts in outdoor workers. This study focused on a sample of 101 outdoor workers (55 male and 46 female; 65 nonsmokers and 36 smokers), all employed in the municipal police in a large Italian city. The personal levels of exposure to Ni were assessed through (a) environmental monitoring of Ni present in the urban air obtained from individual samples and (b) biological monitoring of urinary and blood Ni. The blood count parameters were obtained from the hemochromocytometric tests. Pearson correlation coefficients (r) were calculated to assess the association between the blood and urinary Ni and the complete blood count. Multiple linear regression models were used to examine the associations between the complete blood count and the independent variables (age, gender, years of work for current tasks, cigarette smoking habit (current and never smoker), values of airborne Ni, and blood and urinary Ni). Multiple linear regression analysis performed on the total group of 101 subjects confirms the association among the red blood cells count, the hematocrit, and the urinary Ni (R(2) = 0.520, p = 0.025 and R(2) = 0.530, p = 0.030). These results should lead to further studies on the effects of Ni in working populations exposed to urban pollutants. The possibility that the associations found in our study may be partially explained by other urban pollutants (such as benzene, toluene, and other heavy metals) not taken into consideration in this study cannot be ruled out.

  6. Immunotoxicity Monitoring in a Population Exposed to Polychlorinated Biphenyls

    PubMed Central

    Haase, Hajo; Fahlenkamp, Astrid; Schettgen, Thomas; Esser, Andre; Gube, Monika; Ziegler, Patrick; Kraus, Thomas; Rink, Lothar

    2016-01-01

    The relationship between polychlorinated biphenyl (PCB) burden and several indicators of immune function was investigated as part of the HELPcB (Health Effects in High-Level Exposure to PCB) program, offering bio-monitoring to workers, relatives, and neighbors exposed to PCBs by a German transformers and capacitors recycling company. The present retrospective observational study evaluates the correlation of plasma levels of total PCBs, five indicator congeners (28, 101, 138, 153, 180), and seven dioxin-like congeners (105, 114, 118, 156, 157, 167, 189) with several parameters of immune function. The cross-sectional study was performed immediately after the end of exposure (258 subjects), and one (218 subjects), and two (177 subjects) years later. At the first time point, measurements showed significant positive correlation between congeners with low to medium chlorination and the relative proportion of CD19 positive B-cells among lymphocytes, as well as a negative correlation of PCB114 with serum IgM, and of PCB 28 with suppressor T-cell and NK-cell numbers. Congeners with a high degree of chlorination, in particular PCB157 and 189, were positively associated with expression of the activation marker CD25 on T-cells in the cohort of the second time point. No associations between PCB levels and IFN-y production by T-cells and killing by NK-cells were found. In conclusion, there were several effects on the cellular composition of adaptive immunity, affecting both T- and B-cells. However, the values were not generally outside the reference ranges for healthy adult individuals and did not indicate overt functional immunodeficiency, even in subjects with the uppermost PCB burden. PMID:27005643

  7. Dating and quantification of erosion processes based on exposed roots

    NASA Astrophysics Data System (ADS)

    Stoffel, Markus; Corona, Christophe; Ballesteros-Cánovas, Juan Antonio; Bodoque, José Maria

    2013-08-01

    Soil erosion is a key driver of land degradation and heavily affects sustainable land management in various environments worldwide. An appropriate quantification of rates of soil erosion and a localization of hotspots are therefore critical, as sediment loss has been demonstrated to have drastic consequences on soil productivity and fertility. A consistent body of evidence also exists for a causal linkage between global changes and the temporal frequency and magnitude of erosion, and thus calls for an improved understanding of dynamics and rates of soil erosion for an appropriate management of landscapes and for the planning of preventive or countermeasures. Conventional measurement techniques to infer erosion rates are limited in their temporal resolution or extent. Long-term erosion rates in larger basins have been analyzed with cosmogenic nuclides, but with lower spatial and limited temporal resolutions, thus limiting the possibility to infer micro-geomorphic and climatic controls on the timing, amount and localization of erosion. If based on exposed tree roots, rates of erosion can be inferred with up to seasonal resolution, over decades to centuries of the past and for larger surfaces with homogenous hydrological response units. Root-based erosion rates, thus, constitute a valuable alternative to empirical or physically-based approaches, especially in ungauged basins, but will be controlled by individual or a few extreme events, so that average annual rates of erosion might be highly skewed. In this contribution, we review the contribution made by this biomarker to the understanding of erosion processes and related landform evolution. We report on recent progress in root-based erosion research, illustrate possibilities, caveats and limitations of reconstructed rates, and conclude with a call for further research on various aspects of root-erosion research and for work in new geographic regions.

  8. Brain injury and development in preterm infants exposed to fentanyl

    PubMed Central

    McPherson, Christopher; Haslam, Matthew; Pineda, Roberta; Rogers, Cynthia; Neil, Jeffrey J.; Inder, Terrie E.

    2015-01-01

    Background Fentanyl is commonly utilized in preterm infants. Relatively little is known regarding the neurodevelopmental outcomes of preterm infants exposed to fentanyl. Objective To investigate the association between cumulative fentanyl dose and brain injury and diameters in a cohort of preterm infants Methods Data on demographics, perinatal course, and neonatal course, including total fentanyl exposure prior to term equivalent age, were retrospectively evaluated for 103 infants born at ≤ 30 weeks gestational age who underwent magnetic resonance imaging at term equivalent age (mean gestational age 26.9 ± 1.8 weeks). Magnetic resonance images were evaluated for brain injury and regional brain diameters. Developmental testing was conducted at term equivalent and 2 years of age. Results Seventy-eight infants (76%) received fentanyl (median cumulative dose 3 μg/kg, interquartile range 1 – 441 μg/kg). Cumulative fentanyl dose in the first week of life correlated with the incidence of cerebellar hemorrhage after correction for covariates (OR 2.1, 95% confidence interval 1.1 – 4.1). Cumulative fentanyl dose before term equivalent age correlated with reductions in transverse cerebellar diameter after correction for covariates including the presence of cerebellar hemorrhage (r = 0.461, p = 0.002). No correlation was detected between cumulative fentanyl dose and development at 2 years of age. Conclusions Higher cumulative fentanyl dose in preterm infants correlated with a higher incidence of cerebellar injury and lower cerebellar diameter at term equivalent age. Our findings must be taken with caution, but emphasize the need for future prospective trials examining the risks and benefits of commonly utilized analgesic agents in preterm infants. PMID:26369570

  9. The significance of droughts for hyporheic dwellers: evidence from freshwater crayfish

    PubMed Central

    Kouba, Antonín; Tíkal, Jan; Císař, Petr; Veselý, Lukáš; Fořt, Martin; Příborský, Josef; Patoka, Jiří; Buřič, Miloš

    2016-01-01

    Freshwater biodiversity is globally threatened by various factors while severe weather events like long-term droughts may be substantially devastating. In order to remain in contact with the water or stay in a sufficiently humid environment at drying localities, the ability to withstand desiccation by dwelling in the hyporheic zone, particularly through vertical burrowing is crucial. We assessed the ability of three European native and five non-native crayfish as models to survive and construct vertical burrows in a humid sandy-clayey substrate under a simulated one-week drought. Three native species (Astacus astacus, A. leptodactylus, and Austropotamobius torrentium) suffered extensive mortalities. Survival of non-native species was substantially higher while all specimens of Cherax destructor and Procambarus clarkii survived. The native species and Pacifastacus leniusculus exhibited no ability to construct vertical burrows. Procambarus fallax f. virginalis and P. clarkii constructed bigger and deeper burrows than C. destructor and Orconectes limosus. In the context of predicted weather fluctuations, the ability to withstand desiccation through constructing vertical burrows into the hyporheic zone under drought conditions might play a significant role in the success of particular crayfish species, as well as a wide range of further hyporheic-dwelling aquatic organisms in general. PMID:27225308

  10. The significance of droughts for hyporheic dwellers: evidence from freshwater crayfish

    NASA Astrophysics Data System (ADS)

    Kouba, Antonín; Tíkal, Jan; Císař, Petr; Veselý, Lukáš; Fořt, Martin; Příborský, Josef; Patoka, Jiří; Buřič, Miloš

    2016-05-01

    Freshwater biodiversity is globally threatened by various factors while severe weather events like long-term droughts may be substantially devastating. In order to remain in contact with the water or stay in a sufficiently humid environment at drying localities, the ability to withstand desiccation by dwelling in the hyporheic zone, particularly through vertical burrowing is crucial. We assessed the ability of three European native and five non-native crayfish as models to survive and construct vertical burrows in a humid sandy-clayey substrate under a simulated one-week drought. Three native species (Astacus astacus, A. leptodactylus, and Austropotamobius torrentium) suffered extensive mortalities. Survival of non-native species was substantially higher while all specimens of Cherax destructor and Procambarus clarkii survived. The native species and Pacifastacus leniusculus exhibited no ability to construct vertical burrows. Procambarus fallax f. virginalis and P. clarkii constructed bigger and deeper burrows than C. destructor and Orconectes limosus. In the context of predicted weather fluctuations, the ability to withstand desiccation through constructing vertical burrows into the hyporheic zone under drought conditions might play a significant role in the success of particular crayfish species, as well as a wide range of further hyporheic-dwelling aquatic organisms in general.

  11. Conservation and management of crayfishes: Lessons from Pennsylvania

    USGS Publications Warehouse

    Lieb, D.A.; Bouchard, R.W.; Carline, R.F.; Nuttall, T.R.; Wallace, J.R.; Burkholder, C.L.

    2011-01-01

    North America's crayfish fauna is diverse, ecologically important, and highly threatened. Unfortunately, up-to-date information is scarce, hindering conservation and management efforts. In Pennsylvania and nearby states, recent efforts allowed us to determine the conservation status of several native crayfishes and develop management strategies for those species. Due to rarity and proximity to urban centers and introduced (exotic) crayfishes, Cambarus (Puncticambarus) sp., an undescribed member of the Cambarus acuminatus complex, is critically imperiled in Pennsylvania and possibly range-wide. Orconectes limosus is more widespread; however, recent population losses have been substantial, especially in Pennsylvania and northern Maryland, where its range has declined (retreated eastward) by greater than 200 km. Introduced congeners likely played a major role in those losses. Although extirpated from some areas, Cambarus bartonii bartonii remains widespread and is not an immediate conservation concern. In light of these findings, the role of barriers (e.g., dams), environmental protection, educational programs, and regulations in preventing crayfish invasions and conserving native crayfishes is discussed, and management initiatives centered on those factors are presented. The need for methods to eliminate exotics and monitor natives is highlighted. Although tailored to a specific regional fauna, these ideas have broad applicability and would benefit many North American crayfishes. ?? copyright 2011. Periodicals postage paid at Bethesda.

  12. The significance of droughts for hyporheic dwellers: evidence from freshwater crayfish.

    PubMed

    Kouba, Antonín; Tíkal, Jan; Císař, Petr; Veselý, Lukáš; Fořt, Martin; Příborský, Josef; Patoka, Jiří; Buřič, Miloš

    2016-01-01

    Freshwater biodiversity is globally threatened by various factors while severe weather events like long-term droughts may be substantially devastating. In order to remain in contact with the water or stay in a sufficiently humid environment at drying localities, the ability to withstand desiccation by dwelling in the hyporheic zone, particularly through vertical burrowing is crucial. We assessed the ability of three European native and five non-native crayfish as models to survive and construct vertical burrows in a humid sandy-clayey substrate under a simulated one-week drought. Three native species (Astacus astacus, A. leptodactylus, and Austropotamobius torrentium) suffered extensive mortalities. Survival of non-native species was substantially higher while all specimens of Cherax destructor and Procambarus clarkii survived. The native species and Pacifastacus leniusculus exhibited no ability to construct vertical burrows. Procambarus fallax f. virginalis and P. clarkii constructed bigger and deeper burrows than C. destructor and Orconectes limosus. In the context of predicted weather fluctuations, the ability to withstand desiccation through constructing vertical burrows into the hyporheic zone under drought conditions might play a significant role in the success of particular crayfish species, as well as a wide range of further hyporheic-dwelling aquatic organisms in general. PMID:27225308

  13. Isolation and amino acid sequence of crustacean hyperglycemic hormone precursor-related peptides.

    PubMed

    Tensen, C P; Verhoeven, A H; Gaus, G; Janssen, K P; Keller, R; Van Herp, F

    1991-01-01

    The crustacean hyperglycemic hormone (CHH) is synthesized as part of a larger preprohormone in which the sequence of CHH is N-terminally flanked by a peptide for which the name CPRP (CHH precursor-related peptide) is proposed. Both CHH and CPRP are present in the sinus gland, the neurohemal organ of neurosecretory cells located in the eyestalk of decapod crustaceans. This paper describes the isolation and sequence analysis of CPRPs isolated from sinus glands of the crab Carcinus maenas, the crayfish Orconectes limosus and the lobster Homarus americanus. The published sequence of "peptide H" isolated from the land crab, Cardisoma carnifex, has now been recognized as a CPRP in this species. Sequence comparison reveals a high level of identity for the N-terminal region (residues 1-13) between all four peptides, while identity in the C-terminal domain is high between lobster and crayfish CPRP on the one hand, and between both crab species on the other. Conserved N-terminal residues include a putative monobasic processing site at position 11, which suggests that CPRP may be a biosynthetic intermediate from which a potentially bioactive decapeptide can be derived.

  14. Genetic monitoring of aluminum workers exposed to coal tar pitch volatiles.

    PubMed

    Heussner, J C; Ward, J B; Legator, M S

    1985-03-01

    A group of 50 workers exposed to coal tar pitch volatiles (CTPV) in an aluminum reduction plant and a group of 50 non-exposed workers were selected to evaluate the genotoxic effects of CTPV exposure. A battery of tests was performed on 3 different body fluids; urine, blood and semen. Urine samples were evaluated for mutagenic constituents using the Ames/Salmonella assay. Cultured lymphocytes from blood samples were used to perform cytogenetic analysis. Semen samples were used to measure sperm count, percent abnormal sperm morphology and frequency of sperm carrying double fluorescent bodies (2-F). 14 of 28 (50%) exposed workers and 7 of 36 (19.4%) non-exposed workers had mutagenic urine. This difference was significant (p less than 0.01). Among the non-smokers a significantly higher percentage of workers who were exposed had positive urine (36%) compared to the non-exposed workers (5%) (p less than 0.05). Among the exposed group, more mechanics had mutagenic urine than did other types of workers. Overall chromosome aberration rates were similar in both exposed and non-exposed workers. Among exposed workers a significant inverse correlation (p less than 0.05) between age and chromatid aberration rate was observed. Results of semen analysis failed to detect differences between exposed and non-exposed workers. Results of these tests lend support to a battery approach to genetic monitoring and suggest a link between exposure to CTPV and genotoxic effects. Detection of exposure to mutagens at an early time offers an opportunity for disease prevention by the reduction of exposure.

  15. Evaluation of selenium in biological sample of arsenic exposed female skin lesions and skin cancer patients with related to non-exposed skin cancer patients.

    PubMed

    Kolachi, Nida F; Kazi, Tasneem G; Wadhwa, Sham K; Afridi, Hassan I; Baig, Jameel A; Khan, Sumaira; Shah, Faheem

    2011-08-01

    The antagonistic effects between selenium (Se) and arsenic (As) suggest that low Se status plays an important role in arsenism development. The objective of present study was to assess Se contents in biological samples of As exposed females have skin lesions and cancer with related to non-exposed skin cancer patients. The biological samples (blood and scalp hair) of As exposed group comprises, female skin cancer (ESC) patients admitted in cancer hospitals have skin lesions (ESL) and exposed referents have not both diseases (ER), belongs to As exposed area of Pakistan. For comparative purposes, age matched female skin cancerous patient (RP) and non-cancerous females (NER) belong to non-exposed areas were also selected. The As and Se in acid digests of biological samples were pre-concentrated by complexing with chelating agent (ammonium pyrrolidinedithiocarbamate), and resulted complexes were extracted into non-ionic extractant (Triton X-114), prior to analysis by electrothermal atomic absorption spectrometry. The enhancement factor of about 25 was obtained by pre-concentrating 10 mL of sample solutions. The accuracy of the optimized procedure was evaluated by using certified reference material (BCR 397) with certified values for Se and As and standard addition method at three concentration levels in real samples. No significant differences was observed (p>0.05) when comparing the values obtained by the proposed method, added and certified values of both elements. The biological samples of ESC patients had 2-3 folds higher As and lower Se levels as compared to RP (p<0.001). Understudied exposed referents have high level of As and lower Se contents as compared to referents subjects of non-exposed area (p<0.01). The higher concentration of As and lower levels of Se in biological samples of cancerous patients are consisted with reported studies.

  16. Recently Exposed Fumarole Fields Near Mullet Island, Imperial County, California

    NASA Astrophysics Data System (ADS)

    Lynch, D. K.; Hudnut, K.; Adams, P.; Bernstein, L.

    2011-12-01

    New field observations, lidar measurements, aerial imaging and preliminary laboratory measurements of mud samples are reported of three formerly submerged fumarole fields in the Salton Trough near Mullet Island in southeastern California, USA. The fumarole fields have recently been exposed as the Salton Sea level has dropped. The largest of the three fields visited in January 2011 is irregular in outline with a marked northeast elongation. It is roughly 400 meters long and 120 meters wide. The field consists of approximately one hundred warm to boiling hot (100° C) mud volcanoes (0.1 - 2 m in height), several hundred mud pots, and countless CO2 gas vents. Unusual shaped mud volcanoes in the form of vertical tubes with central vents were observed in many places. Lidar measurements were obtained in the time period Nov 9-13, 2010 using an Optech Orion 200M lidar from an elevation 800 m AGL. They reveal that the terrain immediately surrounding the two fields that are above water level reside on a low (~0.5 m high) gently sloping mound about 500 m across that shows no evidence of lineaments indicative of surface faulting. With other geothermal features, the fumaroles define a well-defined line marking the probable trace of the Calipatria fault. Although the precise locations is uncertain, it appears to define a straight line 4 km long between the Davis-Schrimpf mud volcanoes and Mullet Island. Mullet Island is one of five late Quaternary rhyolitic volcanic necks in the immediate area of the fumaroles. The Calipatria fault is subparallel to the San Andreas and Imperial faults and only one of many verified or suspected faults (including cross faults) in the complex tectonic setting of the Salton Trough. Mud from several volcanoes was analyzed using scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). One sample contained boussingaultite, (NH4)2Mg(SO4)2.6(H2O), a rare mineral that is known to sublime under fumarolic conditions, possibly by

  17. What's exposed? Mapping elements at risk from space

    NASA Astrophysics Data System (ADS)

    Taubenböck, Hannes; Klotz, Martin; Geiß, Christian

    2014-05-01

    The world has suffered from severe natural disasters over the last decennium. The earthquake in Haiti in 2010 or the typhoon "Haiyan" hitting the Philippines in 2013 are among the most prominent examples in recent years. Especially in developing countries, knowledge on amount, location or type of the exposed elements or people is often not given. (Geo)-data are mostly inaccurate, generalized, not up-to-date or even not available at all. Thus, fast and effective disaster management is often delayed until necessary geo-data allow an assessment of effected people, buildings, infrastructure and their respective locations. In the last decade, Earth observation data and methods have developed a product portfolio from low resolution land cover datasets to high resolution spatially accurate building inventories to classify elements at risk or even assess indirectly population densities. This presentation will give an overview on the current available products and EO-based capabilities from global to local scale. On global to regional scale, remote sensing derived geo-products help to approximate the inventory of elements at risk in their spatial extent and abundance by mapping and modelling approaches of land cover or related spatial attributes such as night-time illumination or fractions of impervious surfaces. The capabilities and limitations for mapping physical exposure will be discussed in detail using the example of DLR's 'Global Urban Footprint' initiative. On local scale, the potential of remote sensing particularly lies in the generation of spatially and thematically accurate building inventories for the detailed analysis of the building stock's physical exposure. Even vulnerability-related indicators can be derived. Indicators such as building footprint, height, shape characteristics, roof materials, location, and construction age and structure type have already been combined with civil engineering approaches to assess building stability for large areas

  18. Toxicological outcomes in rats exposed to inhaled ethanol during gestation.

    PubMed

    Beasley, Tracey E; Evansky, Paul A; Martin, Sheppard A; McDaniel, Katherine L; Moser, Virginia C; Luebke, Robert W; Norwood, Joel; Rogers, John M; Copeland, Carey B; Bushnell, Philip J

    2014-01-01

    Recent legislation has encouraged replacing petroleum-based fuels with renewable alternatives including ethanol, which is typically blended with gasoline in the United States at concentrations up to 10%, with allowances for concentrations up to 85% for some vehicles. Efforts to increase the amount of ethanol in gasoline have prompted concerns about the potential toxicity of inhaled ethanol vapors from these fuels. The well-known sensitivity of the developing nervous and immune systems to ingested ethanol, and the lack of information about its toxicity by inhalation prompted the present work on its potential developmental effects in a rat model. Pregnant Long-Evans rats were exposed for 6.5h/day on days 9-20 of gestation to clean air or ethanol vapor at concentrations of 5000, 10,000, or 21,000 ppm, which resulted in estimated peak blood ethanol concentrations (BECs) of 2.3, 6.7, and 192 mg/dL, respectively. No overt toxicity in the dams was observed. Ethanol did not affect litter size or weight, or postnatal weight gain in the pups. Motor activity was normal in offspring through postnatal day (PND) 29. On PND 62, the 5000 and 21,000 ppm groups were more active than controls. On PND 29 and 62, offspring were tested with a functional observational battery, which revealed small changes in the neuromuscular and sensorimotor domains that were not systematically related to dose. Cell-mediated and humoral immunity were not affected by ethanol exposure in 6-week-old offspring. Systolic blood pressure was increased by 10,000 ppm ethanol in males at PND 90 but not at PND 180. No differences in lipoprotein profile, liver function, or kidney function were observed. In summary, prenatal exposure to inhaled ethanol caused some mild changes in physiological and behavioral development in offspring that were not clearly related to inhaled concentration or BEC, and did not produce detectable changes in immune function. This low toxicity of inhaled ethanol may result from the slow

  19. Polymorphic trial in oxidative damage of arsenic exposed Vietnamese

    SciTech Connect

    Fujihara, Junko; Soejima, Mikiko; Yasuda, Toshihiro; Koda, Yoshiro; Kunito, Takashi; Iwata, Hisato; Tanabe, Shinsuke; Takeshita, Haruo

    2011-10-15

    Arsenic causes DNA damage and changes the cellular capacity for DNA repair. Genes in the base excision repair (BER) pathway influence the generation and repair of oxidative lesions. Single nucleotide polymorphisms (SNPs) in human 8-oxoguanine DNA glycosylase (hOGG1) Ser326Cys; apurinic/apyrimidinic endonuclease (APE1) Asp148Glu; X-ray and repair and cross-complementing group 1 (XRCC1) Arg280His and Arg399Gln in the BER genes were analyzed, and the relationship between these 4 SNPs and the urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations of 100 Vietnamese population exposed to arsenic was investigated. Individuals with hOGG1 326Cys/Cys showed significantly higher urinary 8-OHdG concentrations than did those with 326 Ser/Cys and Ser/Ser. As for APE1 Asp148Glu, heterozygous subjects showed significantly higher urinary 8-OHdG concentrations than did those homozygous for Asp/Asp. Moreover, global ethnic comparison of the allelic frequencies of the 4SNPs was performed in 10 population and previous reported data. The mutant allele frequencies of hOGG1 Ser326Cys in the Asian populations were higher than those in the African and Caucasian populations. As for APE1 Asp148Glu, Caucasians showed higher mutant frequencies than those shown by African and Asian populations. Among Asian populations, the Bangladeshi population showed relatively higher mutant allele frequencies of the APE1 Asp148Glu polymorphism. This study is the first to demonstrate the existence of genetic heterogeneity in a worldwide distribution of SNPs (hOGG1 Ser326Cys, APE1 Asp148Glu, XRCC1 Arg280His, and XRCC1 Arg399Gln) in the BER genes. - Highlights: > We showed that hOGG1 and APE1 are associated with urinary 8-OHdG concentrations. > We showed the existence of inter-ethnic differences in hOGG1 and APE1 polymorphism. > These polymorphisms is a genetic marker of susceptibility to oxidative stress.

  20. Hippocampal phosphoproteomics of F344 rats exposed to 1-bromopropane

    SciTech Connect

    Huang, Zhenlie; Ichihara, Sahoko; Oikawa, Shinji; Chang, Jie; Zhang, Lingyi; Hu, Shijie; Huang, Hanlin; Ichihara, Gaku

    2015-01-15

    1-Bromopropane (1-BP) is neurotoxic in both experimental animals and human. To identify phosphorylated modification on the unrecognized post-translational modifications of proteins and investigate their role in 1-BP-induced neurotoxicity, changes in hippocampal phosphoprotein expression levels were analyzed quantitatively in male F344 rats exposed to 1-BP inhalation at 0, 400, or 1000 ppm for 8 h/day for 1 or 4 weeks. Hippocampal protein extracts were analyzed qualitatively and quantitatively by Pro-Q Diamond gel staining and SYPRO Ruby staining coupled with two-dimensional difference in gel electrophoresis (2D-DIGE), respectively, as well as by matrix-assisted laser-desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) to identify phosphoproteins. Changes in selected proteins were further confirmed by Manganese II (Mn{sup 2+})-Phos-tag SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Bax and cytochrome c protein levels were determined by western blotting. Pro-Q Diamond gel staining combined with 2D-DIGE identified 26 phosphoprotein spots (p < 0.05), and MALDI-TOF/MS identified 18 up-regulated proteins and 8 down-regulated proteins. These proteins are involved in the biological process of response to stimuli, metabolic processes, and apoptosis signaling. Changes in the expression of phosphorylated 14-3-3 θ were further confirmed by Mn{sup 2+}-Phos-tag SDS-PAGE. Western blotting showed overexpression of Bax protein in the mitochondria with down-regulation in the cytoplasm, whereas cytochrome c expression was high in the cytoplasm but low in the mitochondria after 1-BP exposure. Our results suggest that the pathogenesis of 1-BP-induced hippocampal damage involves inhibition of antiapoptosis process. Phosphoproteins identified in this study can potentially serve as biomarkers for 1-BP-induced neurotoxicity. - Highlights: • 1-BP modified hippocampal phosphoproteome in rat and 23 altered proteins were identified. • 1-BP changed phosphorylation

  1. Integrity of disposable nitrile exam gloves exposed to simulated movement.

    PubMed

    Phalen, Robert N; Wong, Weng Kee

    2011-05-01

    Every year, millions of health care, first responder, and industry workers are exposed to chemical and biological hazards. Disposable nitrile gloves are a common choice as both a chemical and physical barrier to these hazards, especially as an alternative to natural latex gloves. However, glove selection is complicated by the availability of several types or formulations of nitrile gloves, such as low-modulus, medical grade, low filler, and cleanroom products. This study evaluated the influence of simulated movement on the physical integrity (i.e., holes) of different nitrile exam glove brands and types. Thirty glove products were evaluated out-of-box and after exposure to simulated whole-glove movement for 2 hr. In lieu of the traditional 1 L water-leak test, a modified water-leak test, standardized to detect a 0.15 ± 0.05 mm hole in different regions of the glove, was developed. A specialized air inflation method simulated bidirectional stretching and whole-glove movement. A worst-case scenario with maximum stretching was evaluated. On average, movement did not have a significant effect on glove integrity (chi-square; p=0.068). The average effect was less than 1% between no movement (1.5%) and movement (2.1%) exposures. However, there was significant variability in glove integrity between different glove types (p≤0.05). Cleanroom gloves, on average, had the highest percentage of leaks, and 50% failed the water-leak test. Low-modulus and medical grade gloves had the lowest percentages of leaks, and no products failed the water-leak test. Variability in polymer formulation was suspected to account for the observed discrepancies, as well as the inability of the traditional 1 L water-leak test to detect holes in finger/thumb regions. Unexpectedly, greater than 80% of the glove defects were observed in the finger and thumb regions. It is recommended that existing water-leak tests be re-evaluated and standardized to account for product variability. PMID:21476169

  2. Mortality patterns among workers exposed to acrylamide: 1994 follow up

    PubMed Central

    Marsh, G. M.; Lucas, L. J.; Youk, A. O.; Schall, L. C.

    1999-01-01

    OBJECTIVE: To update the mortality experience of a cohort of 8508 workers with potential exposure to acrylamide at three plants in the United States from 1984-94. METHODS: Analyses of standardised mortality ratios (SMR) with national and local rates and relative risk (RR) regression modelling were performed to assess site specific cancer risks by demographic and work history factors, and exposure indicators for acrylamide and muriatic acid. RESULTS: For the 1925-94 study period, excess and deficit overall mortality risks were found for cancer sites of interest: brain and other central nervous system (CNS) (SMR 0.65, 95% confidence interval (95% CI) 0.36 to 1.09), thyroid gland (SMR 2.11, 95% CI 0.44 to 6.17), testis and other male genital organs (SMR 0.28, 95% CI 0.01 to 1.59), and cancer of the respiratory system (SMR 1.10, 95% CI 0.99 to 1.22); however, none was significant or associated with exposure to acrylamide. A previously reported excess mortality risk of cancer of the respiratory system at one plant remained increased among workers with potential exposure to muriatic acid (RR 1.50, 95% CI 0.86 to 2.59), but was only slightly increased among workers exposed or unexposed to acrylamide. In an exploratory exposure-response analysis of rectal, oesophageal, pancreatic, and kidney cancer, we found increased SMRs for some categories of exposure to acrylamide, but little evidence of an exposure-response relation. A significant 2.26-fold risk (95% CI 1.03 to 4.29) was found for pancreatic cancer among workers with cumulative exposure to acrylamide > 0.30 mg/m3.years; however, no consistent exposure-response relations were detected with the exposure measures considered when RR regression models were adjusted for time since first exposure to acrylamide. CONCLUSION: The contribution of 1115 additional deaths and nearly 60,000 person-years over the 11 year follow up period corroborate the original cohort study findings of little evidence for a causal relation between

  3. Psychiatrically impaired patients often exposed to pregnancy risk.

    PubMed

    Neinstein, L S; Katz, B

    1985-06-01

    The issue of choosing contraceptives for mentally ill patients is important. Over 400,000 female mental patients of childbearing age are treated each year in the US. With less longterm institutionalization, they are increasingly exposed to pregnancy risk. The reproductive rate of mentally ill women has risen markedly since the 1950s. Some evidence exists that pregnancy, childbirth, and child care can contribute to recurrences of psychotic or depressive episodes. Mental patients are interested in family planning, but they may be socially disorganized and thus unable to effectively use community resources. Consequently, they are at especially high risk for unwanted pretnancy. Many mental patients have impaired ability to communicate their needs, making specialized contraceptive services for them imperative in the settings where the patients are usually seen. Before prescribing an oral contraceptive, diaphragm, or IUD, clinicians should obtain informed consent from those patients. For a woman to give adequate informed consent, she must have sufficient knowledge to make a decision, and clinicians must not use coercion in the decision making process. Due to the fact that judgment and reasoning may be impaired in the mentally ill patient, ensuring that she fully understands the risks and benefits of contraceptives may be difficult. Only specially trained professionals should provide contraceptives for the mentally ill. OCs may not be appropriate for patients who are taking antidepressants or who have history of depression. The literature contains contradictory reports about whether or not OCs worsen existing depression or cause depression. 9 of 12 major studies of the association between OC use and depression report depression in 16-56% of women using OCs. 3 studies found no such association. Although vitamin B6 may be a helpful adjunct to OCs for depressed women, pyridoxine may not be entirely benign. Women with mental illness may find mechanical methods of

  4. Biomarker responses in river otters experimentally exposed to oil contamination.

    PubMed

    Ben-David, M; Duffy, L K; Bowyer, R T

    2001-07-01

    Investigations in Prince William Sound (Alaska, USA) following the Exxon Valdez oil spill (EVOS) revealed that river otters (Lontra canadensis) on oiled shores had lower body mass and elevated values of biomarkers, than did otters living on nonoiled shores. In addition, otters from oiled areas selected different habitats, had larger home ranges, and less diverse diets than animals living in nonoiled areas. These differences between river otters from oiled shores and those from nonoiled areas strongly suggested that oil contamination had an effect on physiological and behavioral responses of otters. In this study, we explored the effects of crude oil contamination on river otters experimentally. We hypothesized that exposure to oil would result in elevated values of biomarkers, indicating induced physiological stress. Fifteen wild-caught male river otters were exposed to two levels of weathered crude oil (i.e., control, 5 ppm/day/kg body mass, and 50 ppm/day/kg body mass) under controlled conditions in captivity at the Alaska Sealife Center in Seward (Alaska, USA). Responses of captive river otters to oil ingestion provided mixed results in relation to our hypotheses. Although hemoglobin (Hb, and associated red blood cells) and white blood cells, and possibly interleukin-6 immunoreactive responded in the expected manner, other parameters did not. Aspartate aminotransferase, alanine aminotransferase, and haptoglobin (Hp), did not increase in response to oiling or decreased during rehabilitation. Conversely, principle-component analysis identified values of alkaline phosphatase as responding to oil ingestion in river otters. Our results suggested that opposing processes were concurring in the oiled otters. Elevated production of Hp in response to tissue damage by hydrocarbons likely occurred at the same time with increased removal of Hp-Hb complex from the serum, producing an undetermined pattern in the secretion of Hp. Thus, the use of individual biomarkers as

  5. Biomarker responses in river otters experimentally exposed to oil contamination.

    PubMed

    Ben-David, M; Duffy, L K; Bowyer, R T

    2001-07-01

    Investigations in Prince William Sound (Alaska, USA) following the Exxon Valdez oil spill (EVOS) revealed that river otters (Lontra canadensis) on oiled shores had lower body mass and elevated values of biomarkers, than did otters living on nonoiled shores. In addition, otters from oiled areas selected different habitats, had larger home ranges, and less diverse diets than animals living in nonoiled areas. These differences between river otters from oiled shores and those from nonoiled areas strongly suggested that oil contamination had an effect on physiological and behavioral responses of otters. In this study, we explored the effects of crude oil contamination on river otters experimentally. We hypothesized that exposure to oil would result in elevated values of biomarkers, indicating induced physiological stress. Fifteen wild-caught male river otters were exposed to two levels of weathered crude oil (i.e., control, 5 ppm/day/kg body mass, and 50 ppm/day/kg body mass) under controlled conditions in captivity at the Alaska Sealife Center in Seward (Alaska, USA). Responses of captive river otters to oil ingestion provided mixed results in relation to our hypotheses. Although hemoglobin (Hb, and associated red blood cells) and white blood cells, and possibly interleukin-6 immunoreactive responded in the expected manner, other parameters did not. Aspartate aminotransferase, alanine aminotransferase, and haptoglobin (Hp), did not increase in response to oiling or decreased during rehabilitation. Conversely, principle-component analysis identified values of alkaline phosphatase as responding to oil ingestion in river otters. Our results suggested that opposing processes were concurring in the oiled otters. Elevated production of Hp in response to tissue damage by hydrocarbons likely occurred at the same time with increased removal of Hp-Hb complex from the serum, producing an undetermined pattern in the secretion of Hp. Thus, the use of individual biomarkers as

  6. Integrity of disposable nitrile exam gloves exposed to simulated movement.

    PubMed

    Phalen, Robert N; Wong, Weng Kee

    2011-05-01

    Every year, millions of health care, first responder, and industry workers are exposed to chemical and biological hazards. Disposable nitrile gloves are a common choice as both a chemical and physical barrier to these hazards, especially as an alternative to natural latex gloves. However, glove selection is complicated by the availability of several types or formulations of nitrile gloves, such as low-modulus, medical grade, low filler, and cleanroom products. This study evaluated the influence of simulated movement on the physical integrity (i.e., holes) of different nitrile exam glove brands and types. Thirty glove products were evaluated out-of-box and after exposure to simulated whole-glove movement for 2 hr. In lieu of the traditional 1 L water-leak test, a modified water-leak test, standardized to detect a 0.15 ± 0.05 mm hole in different regions of the glove, was developed. A specialized air inflation method simulated bidirectional stretching and whole-glove movement. A worst-case scenario with maximum stretching was evaluated. On average, movement did not have a significant effect on glove integrity (chi-square; p=0.068). The average effect was less than 1% between no movement (1.5%) and movement (2.1%) exposures. However, there was significant variability in glove integrity between different glove types (p≤0.05). Cleanroom gloves, on average, had the highest percentage of leaks, and 50% failed the water-leak test. Low-modulus and medical grade gloves had the lowest percentages of leaks, and no products failed the water-leak test. Variability in polymer formulation was suspected to account for the observed discrepancies, as well as the inability of the traditional 1 L water-leak test to detect holes in finger/thumb regions. Unexpectedly, greater than 80% of the glove defects were observed in the finger and thumb regions. It is recommended that existing water-leak tests be re-evaluated and standardized to account for product variability.

  7. Toxicological outcomes in rats exposed to inhaled ethanol during gestation.

    PubMed

    Beasley, Tracey E; Evansky, Paul A; Martin, Sheppard A; McDaniel, Katherine L; Moser, Virginia C; Luebke, Robert W; Norwood, Joel; Rogers, John M; Copeland, Carey B; Bushnell, Philip J

    2014-01-01

    Recent legislation has encouraged replacing petroleum-based fuels with renewable alternatives including ethanol, which is typically blended with gasoline in the United States at concentrations up to 10%, with allowances for concentrations up to 85% for some vehicles. Efforts to increase the amount of ethanol in gasoline have prompted concerns about the potential toxicity of inhaled ethanol vapors from these fuels. The well-known sensitivity of the developing nervous and immune systems to ingested ethanol, and the lack of information about its toxicity by inhalation prompted the present work on its potential developmental effects in a rat model. Pregnant Long-Evans rats were exposed for 6.5h/day on days 9-20 of gestation to clean air or ethanol vapor at concentrations of 5000, 10,000, or 21,000 ppm, which resulted in estimated peak blood ethanol concentrations (BECs) of 2.3, 6.7, and 192 mg/dL, respectively. No overt toxicity in the dams was observed. Ethanol did not affect litter size or weight, or postnatal weight gain in the pups. Motor activity was normal in offspring through postnatal day (PND) 29. On PND 62, the 5000 and 21,000 ppm groups were more active than controls. On PND 29 and 62, offspring were tested with a functional observational battery, which revealed small changes in the neuromuscular and sensorimotor domains that were not systematically related to dose. Cell-mediated and humoral immunity were not affected by ethanol exposure in 6-week-old offspring. Systolic blood pressure was increased by 10,000 ppm ethanol in males at PND 90 but not at PND 180. No differences in lipoprotein profile, liver function, or kidney function were observed. In summary, prenatal exposure to inhaled ethanol caused some mild changes in physiological and behavioral development in offspring that were not clearly related to inhaled concentration or BEC, and did not produce detectable changes in immune function. This low toxicity of inhaled ethanol may result from the slow

  8. Electrophoresis pattern of serum from mice exposed to different concentrations of sulfur dioxide

    NASA Technical Reports Server (NTRS)

    Singh, J.

    1977-01-01

    Three day old mice were continuously exposed to sulphur dioxide concentrations at 0ppm, 0.05ppm, 0.15ppm and 1ppm for eight weeks. At the end of the experiment, blood samples were collected and centrifuged for electrophoresis studies of the serum in 5 percent acrylamide gel. The length of bands of different serum proteins from the SO2 exposed mice was at a variance as compared with the length of bands from the control exposed mice and alpha-1 band seems to be missing from the serum of SO2 exposed mice.

  9. The affect of the space environment on the survival of Halorubrum chaoviator and Synechococcus (Nägeli): data from the Space Experiment OSMO on EXPOSE-R

    NASA Astrophysics Data System (ADS)

    Mancinelli, R. L.

    2015-01-01

    We have shown using ESA's Biopan facility flown in Earth orbit that when exposed to the space environment for 2 weeks the survival rate of Synechococcus (Nägeli), a halophilic cyanobacterium isolated from the evaporitic gypsum-halite crusts that form along the marine intertidal, and Halorubrum chaoviator a member of the Halobacteriaceae isolated from an evaporitic NaCl crystal obtained from a salt evaporation pond, were higher than all other test organisms except Bacillus spores. These results led to the EXPOSE-R mission to extend and refine these experiments as part of the experimental package for the external platform space exposure facility on the ISS. The experiment was flown in February 2009 and the organisms were exposed to low-Earth orbit for nearly 2 years. Samples were either exposed to solar ultraviolet (UV)-radiation (λ > 110 nm or λ > 200 nm, cosmic radiation (dosage range 225-320 mGy), or kept in darkness shielded from solar UV-radiation. Half of each of the UV-radiation exposed samples and dark samples were exposed to space vacuum and half kept at 105 pascals in argon. Duplicate samples were kept in the laboratory to serve as unexposed controls. Ground simulation control experiments were also performed. After retrieval, organism viability was tested using Molecular Probes Live-Dead Bac-Lite stain and by their reproduction capability. Samples kept in the dark, but exposed to space vacuum had a 90 +/- 5% survival rate compared to the ground controls. Samples exposed to full UV-radiation for over a year were bleached and although results from Molecular Probes Live-Dead stain suggested ~10% survival, the data indicate that no survival was detected using cell growth and division using the most probable number method. Those samples exposed to attenuated UV-radiation exhibited limited survival. Results from of this study are relevant to understanding adaptation and evolution of life, the future of life beyond earth, the potential for interplanetary

  10. The Affect of the Space Environment on the Survival of Halorubrum Chaoviator and Synechococcus (Nageli): Data from the Space Experiment OSMO on EXPOSE-R

    NASA Technical Reports Server (NTRS)

    Mancinelli, R. L.

    2014-01-01

    We have shown using ESA's Biopan facility flown in Earth orbit that when exposed to the space environment for 2 weeks the survival rate of Synechococcus (Nageli), a halophilic cyanobacterium isolated from the evaporitic gypsum-halite crusts that form along the marine intertidal, and Halorubrum chaoviator a member of the Halobacteriaceae isolated from an evaporitic NaCl crystal obtained from a salt evaporation pond, were higher than all other test organisms except Bacillus spores. These results led to the EXPOSE-R mission to extend and refine these experiments as part of the experimental package for the external platform space exposure facility on the ISS. The experiment was flown in February 2009 and the organisms were exposed to low-Earth orbit for nearly 2 years. Samples were either exposed to solar ultraviolet (UV)-radiation (lambda is greater than 110 nm or lambda is greater than 200 nm, cosmic radiation (dosage range 225-320 mGy), or kept in darkness shielded from solar UV-radiation. Half of each of the UV-radiation exposed samples and dark samples were exposed to space vacuum and half kept at 105 pascals in argon. Duplicate samples were kept in the laboratory to serve as unexposed controls. Ground simulation control experiments were also performed. After retrieval, organism viability was tested using Molecular Probes Live-Dead Bac-Lite stain and by their reproduction capability. Samples kept in the dark, but exposed to space vacuum had a 90 +/- 5% survival rate compared to the ground controls. Samples exposed to full UV-radiation for over a year were bleached and although results from Molecular Probes Live-Dead stain suggested approximately 10% survival, the data indicate that no survival was detected using cell growth and division using the most probable number method. Those samples exposed to attenuated UV-radiation exhibited limited survival. Results from of this study are relevant to understanding adaptation and evolution of life, the future of life

  11. Validating vulnerability functions for buildings exposed to Alpine torrent processes

    NASA Astrophysics Data System (ADS)

    Totschnig, R.; Fuchs, S.

    2012-04-01

    Vulnerability assessment is generally seen as an important component in the framework of risk assessment. Focusing on the physical vulnerability and following a natural science perspective, vulnerability functions can be used to quantify vulnerability by setting up a mathematical relationship between the degree of loss of an element at risk exposed and the corresponding intensity of the hazardous process. The examined elements at risk were defined as those buildings that were firstly located on the torrent fans of individual Austrian test sites and secondly characterised by mixed types of construction composed from brick masonry and concrete, however used for different purposes (private residential and commercial accommodation buildings). The degree of loss was calculated as the ratio between the damage and the reconstruction value of the corresponding building. The damage was quantitatively registered in terms of monetary loss after the event by professional damage appraisers. The reconstruction values were calculated based on an insurance approach using unit prices per m2. The intensity of the process (fluvial sediment transport and debris flow) was proxied for each individual building in terms of deposition height. Additionally, a relative intensity, composed from a ratio between the deposition height and the height of the affected building, was used to compensate the influence of different building heights on the degree of loss at a given process intensity. The determination of the degree of loss as well as the corresponding intensity yields a scatterplot of vulnerability values for each individual building; illustrating both the degree of loss (ordinate) and the process intensity (abscissa). Nonlinear regression approaches in terms of cumulative distribution functions were applied to derive the mathematical relation between process intensities and degrees of loss. The corresponding parameters were estimated by using a sequential quadratic programming algorithm

  12. SCM Paste Samples Exposed To Aggressive Solutions. Cementitious Barriers Partnership

    SciTech Connect

    Foster, T.

    2014-12-01

    This report summarizes experimental work performed by SIMCO Technologies Inc. (SIMCO) as part of the Cementitious Barriers Partnership (CBP) project. The test series followed an experimental program dedicated to the study of ordinary Portland cement (OPC) hydrated cement pastes exposed to aggressive solutions. In the present study, the scope is extended to hydrated cement pastes incorporating supplementary cementitious materials (SCM) such as fly ash and ground granulated blast furnace slag (GGBFS). Also, the range of aggressive contact solutions was expanded. The experimental program aimed at testing aggressive contact solutions that more closely mimic the chemical composition of saltstone pore solution. Five different solutions, some of which incorporated high levels of carbonate and nitrate, were placed in contact with four different hydrated cement paste mixes. In all solutions, 150 mmol/L of SO42– (14 400 ppm) were present. The solutions included different pH conditions and different sodium content. Two paste mixes were equivalent to Vault 1/4 and Vault 2 concrete mixes used at SRS in storage structures. Two additional paste mixes, cast at the same water-to-cement ratio and using the same cements but without SCMs, were also tested. The damage evolution in samples was monitored using ultrasonic pulse velocity (UPV) and mass measurements. After three and twelve months of exposure conditions, samples were taken out of solution containers and analyzed to perform migration tests and porosity measurements. Globally, results were in line with the previous study and confirmed that high pH may limit the formation of some deleterious phases like gypsum. In this case, ettringite may form but is not necessarily associated with damage. However, the high concentration of sodium may be associated with the formation of an AFm-like mineral called U-phase. The most significant evidences of damage were all associated with the Vault 2 paste analog. This

  13. A well-preserved Cambrian impact exposed in Central Sweden

    NASA Astrophysics Data System (ADS)

    Lindström, Maurits; Ekvall, Johan; Hagenfeldt, Stefan E.; Säwe, Brigitta; Sturkell, Erik F. F.

    1991-02-01

    The Lockne impact crater south of Östersund formed in the early Middle Cambrian with a diameter of 7 km. It is identified by its rim wall of crushed Precambrian basement granite, by fragments of impact melt, and by grains of shocked quartz. The exceptional preservation, in particular of the rim wall, is due to a complicated geological history, the first stage of which consisted of burial by marine sediments. This stage lasted until the Middle Ordovician, or over 50 million years. An early Caradoc lowering of the sea-level may have induced debris flows that stripped the rim wall of much of its sedimentary cover. Because normal marine sedimentation recommenced soon after this event, the structure was not seriously damaged, as it was buried again. The Caledonian orogeny emplaced an overthrust nappe as ultimate protection, which was removed by a recent erosion episode from all but the center of the structure. Structures formed by the impact of extraterrestrial bodies are very rare throughout much of Europe, because such structures are neither well preserved nor displayed in young mountain belts or sedimentary basins. However, northern Europe has several ascertained structures of this kind ( Svensson & Wickman, 1965; Svensson, 1968; Bruun & Dahlman, 1982; Kala et al., 1984; Flodén et al., 1986; Wickman, 1988). Unfortunately, the hitherto known structures are either poorly preserved or hidden by younger deposits. We are reporting the discovery of a well-preserved exposed and accessible impact structure that has escaped the notice of geologists although important features of it have been described and puzzled over by generations of researchers ( Wiman, 1900; Hadding, 1927; Thorslund, 1940; Lindström et al., 1983). The structure is located in the Lockne area to the south of Östersund in central Sweden. It has a diameter of 7 km and its center is near Tramsta on the northwest shore of Lake Locknesjön (Fig. 1). Its middle is covered by folded Lower to Middle Ordovician

  14. Biological studies of swine exposed to 60-Hz electric fields. Volume 7. Neurology. Final report

    SciTech Connect

    Not Available

    1985-12-01

    Neurophysiological responses in three generations of miniature swine chronically exposed to a 30-kV/m, 60-Hz electric field have been assessed in a series of screening experiments. Results are presented from experiments on peripheral nerve function in parental (F/sub 0/) female swine at 100 days of gestation, and from experiments on synaptic transmission in first- and second-generation (F/sub 1/ and F/sub 2/) progeny at 6 weeks of age, all following chronic exposure to a 60-Hz electric field. In the several measures of peripheral nerve function examined, only two showed consistent differences between exposed and sham-exposed animals: C-fiber (but not B-fiber) conduction velocity was decreased in nerve preparations from exposed swine, and recovery, as measured by the increase in amplitude of the compound action potential, was consistently, although not statistically, less in B- and C-fibers from exposed animals when compared to values for the sham-exposed controls. Although changes (increases or decreases) in various parameters of synaptic transmission were observed between exposed and sham-exposed groups, the differences were not consistent across experiments or generations. Only one measure of synaptic function showed a consistent difference throughout the studies: the conduction velocities of B and C components of the postsynaptic compound action potential were increased following electric-field exposure (statistically significant only in B-fibers of the F/sub 2/ generations). 7 refs., 60 figs., 17 tabs.

  15. 77 FR 12881 - Hearing of the Attorney General's National Task Force on Children Exposed to Violence

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-02

    ... Violence AGENCY: Office of Justice Programs (OJP), Justice. ACTION: Notice of hearing. SUMMARY: This is an announcement of the third hearing of the Attorney General's National Task Force on Children Exposed to Violence... Justice, with valuable advice in the areas of children exposed to violence for the purpose of...

  16. 77 FR 39264 - Meeting of the Attorney General's National Task Force on Children Exposed to Violence

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ... Violence AGENCY: Office of Justice Programs (OJP), Justice. ACTION: Notice of meeting. SUMMARY: This is an announcement of a meeting of the Attorney General's National Task Force on Children Exposed to Violence (the..., with valuable advice in the areas of children exposed to violence for the purpose of addressing...

  17. 9 CFR 85.5 - Interstate movement of infected swine or exposed swine.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Interstate movement of infected swine or exposed swine. 85.5 Section 85.5 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... PRODUCTS PSEUDORABIES § 85.5 Interstate movement of infected swine or exposed swine. Infected swine...

  18. Resilience among Children Exposed to Domestic Violence: The Role of Risk and Protective Factors

    ERIC Educational Resources Information Center

    Martinez-Torteya, Cecilia; Bogat, G. Anne; von Eye, Alexander; Levendosky, Alytia A.

    2009-01-01

    Individual and family characteristics that predict resilience among children exposed to domestic violence (DV) were examined. Mother-child dyads (n = 190) were assessed when the children were 2, 3, and 4 years of age. DV-exposed children were 3.7 times more likely than nonexposed children to develop internalizing or externalizing problems.…

  19. Membrane stability of winter wheat plants exposed to subzero temperatures for variable lengths of time

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability to survive episodes of subfreezing temperature is essential to winter wheat. Fully cold-acclimated plants of six lines of winter wheat were exposed to -12, -14, -16 or -18° C, four 1-5 hours. Electrolyte leakage and plant survival were used to assess damage to the plants. Plants exposed ...

  20. 46 CFR 169.721 - Storm sails and halyards (exposed and partially protected waters only).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Storm sails and halyards (exposed and partially... § 169.721 Storm sails and halyards (exposed and partially protected waters only). (a) Unless clearly unsuitable, each vessel must have one storm trysail of appropriate size. It must be sheeted independently...

  1. 46 CFR 169.721 - Storm sails and halyards (exposed and partially protected waters only).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Storm sails and halyards (exposed and partially... § 169.721 Storm sails and halyards (exposed and partially protected waters only). (a) Unless clearly unsuitable, each vessel must have one storm trysail of appropriate size. It must be sheeted independently...

  2. 46 CFR 169.721 - Storm sails and halyards (exposed and partially protected waters only).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Storm sails and halyards (exposed and partially... § 169.721 Storm sails and halyards (exposed and partially protected waters only). (a) Unless clearly unsuitable, each vessel must have one storm trysail of appropriate size. It must be sheeted independently...

  3. 46 CFR 169.721 - Storm sails and halyards (exposed and partially protected waters only).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Storm sails and halyards (exposed and partially... § 169.721 Storm sails and halyards (exposed and partially protected waters only). (a) Unless clearly unsuitable, each vessel must have one storm trysail of appropriate size. It must be sheeted independently...

  4. 46 CFR 169.721 - Storm sails and halyards (exposed and partially protected waters only).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Storm sails and halyards (exposed and partially... § 169.721 Storm sails and halyards (exposed and partially protected waters only). (a) Unless clearly unsuitable, each vessel must have one storm trysail of appropriate size. It must be sheeted independently...

  5. Attachment Status in Children Prenatally Exposed to Cocaine and Other Substances

    ERIC Educational Resources Information Center

    Seifer, Ronald; LaGasse, Linda L.; Lester, Barry; Bauer, Charles R.; Shankaran, Seetha; Bada, Henrietta S.; Wright, Linda L.; Smeriglio, Vincent L.; Liu, Jing

    2004-01-01

    Attachment status of children exposed in utero to cocaine, opiates, and other substances was examined at 18 months (n=860) and 36 months (n=732) corrected age. Children exposed to cocaine and opiates had slightly lower rates of attachment security (but not disorganization), and their insecurity was skewed toward ambivalent, rather than avoidant,…

  6. 30 CFR 75.521 - Lightning arresters; ungrounded and exposed power conductors and telephone wires.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Lightning arresters; ungrounded and exposed... Electrical Equipment-General § 75.521 Lightning arresters; ungrounded and exposed power conductors and... leads underground shall be equipped with suitable lightning arresters of approved type within 100...

  7. 30 CFR 75.521 - Lightning arresters; ungrounded and exposed power conductors and telephone wires.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Lightning arresters; ungrounded and exposed... Electrical Equipment-General § 75.521 Lightning arresters; ungrounded and exposed power conductors and... leads underground shall be equipped with suitable lightning arresters of approved type within 100...

  8. 30 CFR 75.521 - Lightning arresters; ungrounded and exposed power conductors and telephone wires.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Lightning arresters; ungrounded and exposed... Electrical Equipment-General § 75.521 Lightning arresters; ungrounded and exposed power conductors and... leads underground shall be equipped with suitable lightning arresters of approved type within 100...

  9. 30 CFR 75.521 - Lightning arresters; ungrounded and exposed power conductors and telephone wires.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Lightning arresters; ungrounded and exposed... Electrical Equipment-General § 75.521 Lightning arresters; ungrounded and exposed power conductors and... leads underground shall be equipped with suitable lightning arresters of approved type within 100...

  10. Genetic and demographic responses of mosquitofish (Gambusia holbrooki) populations exposed to mercury for multiple generations

    SciTech Connect

    Tatara, C.P.; Mulvey, M.; Newman, M.C.

    1999-12-01

    Genetic and demographic responses of mosquitofish were examined after multiple generations of exposure to mercury. Previous studies of acute lethal exposures of mosquitofish to either mercury or arsenic demonstrated a consistent correlation between time to death and genotype at the glucosephosphate isomerase-2 (Gpi-2) locus. A mesocosm study involving mosquitofish populations exposed to mercury for 111 d showed significant female sexual selection and fecundity selection at the Gpi-2 locus. Here the mesocosm study was extended to populations exposed to mercury for several (approx. four) generations. After 2 years, control and mercury-exposed populations met Hardy-Weinberg expectations and showed no evidence of genetic bottlenecks. The mean number of heterozygous loci did not differ significantly between the mercury-exposed and control populations. Significant differences in allele frequencies at the Gpi-2 locus were observed between the mercury-exposed and control populations. Relative to the initial and control allele frequencies, the GPI-2{sup 100} allele frequency was lower, the Gpi-2{sup 66} allele frequency increased, but the Gpi-2{sup 38} allele frequency did not change in mercury-exposed populations. No significant differences were found in standard length, weight, sex ratio, or age class ratio between the control and mercury-exposed populations. Allele frequency changes at the Gpi-2 locus suggest population-level response to chronic mercury exposure. Changes in allele frequency may be useful as indicators of population response to contaminants, provided that the population in question is well understood.

  11. Circulating immune/inflammation markers in Chinese workers occupationally exposed to formaldehyde

    PubMed Central

    Seow, Wei Jie; Zhang, Luoping; Vermeulen, Roel; Tang, Xiaojiang; Hu, Wei; Bassig, Bryan A.; Ji, Zhiying; Shiels, Meredith S.; Kemp, Troy J.; Shen, Min; Qiu, Chuangyi; Reiss, Boris; Beane Freeman, Laura E.; Blair, Aaron; Kim, Christopher; Guo, Weihong; Wen, Cuiju; Li, Laiyu; Pinto, Ligia A.; Huang, Hanlin; Smith, Martyn T.; Hildesheim, Allan; Rothman, Nathaniel; Lan, Qing

    2015-01-01

    Background. Formaldehyde has been classified as a human myeloid leukemogen. However, the mechanistic basis for this association is still debated. Objectives. We aimed to evaluate whether circulating immune/inflammation markers were altered in workers occupationally exposed to formaldehyde. Methods. Using a multiplexed bead-based assay, we measured serum levels of 38 immune/inflammation markers in a cross-sectional study of 43 formaldehyde-exposed and 51 unexposed factory workers in Guangdong, China. Linear regression models adjusting for potential confounders were used to compare marker levels in exposed and unexposed workers. Results. We found significantly lower circulating levels of two markers among exposed factory workers compared with unexposed controls that remained significant after adjusting for potential confounders and multiple comparisons using a false discovery rate of 10%, including chemokine (C-X-C motif) ligand 11 (36.2 pg/ml in exposed versus 48.4 pg/ml in controls, P = 0.0008) and thymus and activation regulated chemokine (52.7 pg/ml in exposed versus 75.0 pg/ml in controls, P = 0.0028), suggesting immunosuppression among formaldehyde-exposed workers. Conclusions. Our findings are consistent with recently emerging understanding that immunosuppression might be associated with myeloid diseases. These findings, if replicated in a larger study, may provide insights into the mechanisms by which formaldehyde promotes leukemogenesis. PMID:25908645

  12. Analysis of emotionality and locomotion in radio-frequency electromagnetic radiation exposed rats.

    PubMed

    Narayanan, Sareesh Naduvil; Kumar, Raju Suresh; Paval, Jaijesh; Kedage, Vivekananda; Bhat, M Shankaranarayana; Nayak, Satheesha; Bhat, P Gopalakrishna

    2013-07-01

    In the current study the modulatory role of mobile phone radio-frequency electromagnetic radiation (RF-EMR) on emotionality and locomotion was evaluated in adolescent rats. Male albino Wistar rats (6-8 weeks old) were randomly assigned into the following groups having 12 animals in each group. Group I (Control): they remained in the home cage throughout the experimental period. Group II (Sham exposed): they were exposed to mobile phone in switch-off mode for 28 days, and Group III (RF-EMR exposed): they were exposed to RF-EMR (900 MHz) from an active GSM (Global system for mobile communications) mobile phone with a peak power density of 146.60 μW/cm(2) for 28 days. On 29th day, the animals were tested for emotionality and locomotion. Elevated plus maze (EPM) test revealed that, percentage of entries into the open arm, percentage of time spent on the open arm and distance travelled on the open arm were significantly reduced in the RF-EMR exposed rats. Rearing frequency and grooming frequency were also decreased in the RF-EMR exposed rats. Defecation boli count during the EPM test was more with the RF-EMR group. No statistically significant difference was found in total distance travelled, total arm entries, percentage of closed arm entries and parallelism index in the RF-EMR exposed rats compared to controls. Results indicate that mobile phone radiation could affect the emotionality of rats without affecting the general locomotion.

  13. Intracellular free calcium concentration and calcium transport in human erythrocytes of lead-exposed workers

    SciTech Connect

    Quintanar-Escorza, M.A.; Gonzalez-Martinez, M.T.; Navarro, L.; Maldonado, M.; Arevalo, B.; Calderon-Salinas, J.V. . E-mail: jcalder@cinvestav.mx

    2007-04-01

    Erythrocytes are the route of lead distribution to organs and tissues. The effect of lead on calcium homeostasis in human erythrocytes and other excitable cells is not known. In the present work we studied the effect of lead intoxication on the uptake and efflux (measured as (Ca{sup 2+}-Mg{sup 2+})-ATPase activity) of calcium were studied in erythrocytes obtained from lead-exposed workers. Blood samples were taken from 15 workers exposed to lead (blood lead concentration 74.4 {+-} 21.9 {mu}g/dl) and 15 non-exposed workers (9.9 {+-} 2 {mu}g/dl). In erythrocytes of lead-exposed workers, the intracellular free calcium was 79 {+-} 13 nM, a significantly higher concentration (ANOVA, P < 0.01) than the one detected in control (30 {+-} 9 nM). The enhanced intracellular free calcium was associated with a higher osmotic fragility and with important modifications in erythrocytes shape. The high intracellular free calcium in lead-exposed workers was also related to a 100% increase in calcium incorporation and to 50% reduction of (Ca{sup 2+}-Mg{sup 2+})-ATPase activity. Lipid peroxidation was 1.7-fold higher in erythrocytes of lead-exposed workers as compared with control. The alteration on calcium equilibrium in erythrocytes is discussed in light of the toxicological effects in lead-exposed workers.

  14. Blood level of cadmium and lead in occupationally exposed persons in Gwagwalada, Abuja, Nigeria

    PubMed Central

    2015-01-01

    This study was designed to assess the blood levels of cadmium and lead in some occupationally exposed individuals and compare the values with non-exposed individuals, with the aim of increasing the awareness of health risk caused by these heavy metals. A total of 120 subjects (64 occupationally exposed and 56 non-exposed subjects) with the age range of 15–40 years were studied in cross-sectional study conducted between September 2012 and February 2013 in Gwagwalada area of Abuja, Nigeria. Blood cadmium and lead were analyzed using an atomic absorption spectrophotometer (AAS). The respective mean blood levels of cadmium and lead were 11.63±1.73 μg/dl and 45.43±6.93 μg/dl in occupationally-exposed subjects, while in non-exposed subjects 2.03±0.55 μg/dl and 12.08±2.87 μg/dl. The results show that occupational exposure increases the blood level of cadmium and lead, which consequently increases the health risk of the exposed individuals. PMID:27486374

  15. Forced exercise improves passive avoidance memory in morphine-exposed rats.

    PubMed

    Saadipour, K; Sarkaki, A; Alaei, H; Badavi, M; Rahim, F

    2009-09-01

    The aim of this study was to investigate the effect of short-term forced exercise protocol on passive avoidance retention in morphine-exposed rats. Effects of morphine on acquisition and retrieval of retention have been proven in the avoidance paradigms. Twenty four male Wistar rats weighing 250-300 g were used in this study. Animals were randomly divided into four groups including: (1) non-morphine-exposed without exercise (nA.nE) (2) non-morphine-exposed with exercise (nA.E) (3) morphine-exposed without exercise (A.nE) and (4) morphine-exposed with exercise (A.E). Rats ran as forced exercise on the motorized treadmill 1 h daily for ten days. Morphine-exposed animals received intraperitoneal morphine during first 5 days of the exercise period and their dependence to morphine was confirmed by naloxane admistration (10 mg kg(-1), i.p.) and withdrawal test. After 10 days of forced exercise, step down latency was tested and Inflexion Ratio (IR) was evaluated in each rat. Baseline step down latencies before any morphine exposing or exercise have shown no significant alteration in all groups. Inflexion Ratio (IR) ofnA.E group has increased significantly (p<0.001) at 1, 3, 7 and 14 days after receiving shock (learning) compared to nA.nE and A.E groups. Our data showed that short-term forced exercise on treadmill improved retention in both morphine-exposed and non morphine-exposed rats at least up to 7 days and more than 14 days, respectively. Alteration in retention between exercised groups may attribute the release of adrenal stress hormones such as epinephrine and corticosterone because of the emotional arousal.

  16. General guidelines for medically screening mixed population groups potentially exposed to nerve or vesicant agents

    SciTech Connect

    Watson, A.P.; Munro, N.B.; Sidell, F.R.; Leffingwell, S.S.

    1992-01-01

    A number of state and local planners have requested guidance on screening protocols and have expressed interest in sampling body fluids from exposed or potentially exposed individuals as a means of estimating agent dose. These guidelines have been developed to provide a clear statement that could be used by state and local emergency response personnel in the event of a nerve or vesicant agent incident resulting in off-post contamination; maximum protection from harm is the goal. The assumption is that any population group so exposed would be heterogeneous for age, gender, reproductive status, and state of health.

  17. Time-dependent dielectric breakdown of plasma-exposed porous organosilicate glass

    NASA Astrophysics Data System (ADS)

    Nichols, M. T.; Sinha, H.; Wiltbank, C. A.; Antonelli, G. A.; Nishi, Y.; Shohet, J. L.

    2012-03-01

    Time-dependent dielectric breakdown (TDDB) is a major concern for low-k organosilicate dielectrics. To examine the effect of plasma exposure on TDDB degradation, time-to-breakdown measurements were made on porous SiCOH before and after exposure to plasma. A capillary-array window was used to separate charged particle and vacuum ultraviolet (VUV) photon bombardment. Samples exposed to VUV photons, and a combination of VUV photons and ion bombardment exhibited significant degradation in breakdown time. The samples exposed to VUV photons and ion bombardment showed more degradation in breakdown time in comparison to samples exposed to VUV photons alone.

  18. Transcriptomic responses of germinating Bacillus subtilis spores exposed to 1.5 years of space and simulated martian conditions on the EXPOSE-E experiment PROTECT.

    PubMed

    Nicholson, Wayne L; Moeller, Ralf; Horneck, Gerda

    2012-05-01

    Because of their ubiquity and resistance to spacecraft decontamination, bacterial spores are considered likely potential forward contaminants on robotic missions to Mars. Thus, it is important to understand their global responses to long-term exposure to space or martian environments. As part of the PROTECT experiment, spores of B. subtilis 168 were exposed to real space conditions and to simulated martian conditions for 559 days in low-Earth orbit mounted on the EXPOSE-E exposure platform outside the European Columbus module on the International Space Station. Upon return, spores were germinated, total RNA extracted, fluorescently labeled, and used to probe a custom Bacillus subtilis microarray to identify genes preferentially activated or repressed relative to ground control spores. Increased transcript levels were detected for a number of stress-related regulons responding to DNA damage (SOS response, SPβ prophage induction), protein damage (CtsR/Clp system), oxidative stress (PerR regulon), and cell envelope stress (SigV regulon). Spores exposed to space demonstrated a much broader and more severe stress response than spores exposed to simulated martian conditions. The results are discussed in the context of planetary protection for a hypothetical journey of potential forward contaminant spores from Earth to Mars and their subsequent residence on Mars.

  19. Evolution of organic molecules under Mars-like UV radiation with EXPOSE-R2, a photochemistry experiment outside the International Space Station

    NASA Astrophysics Data System (ADS)

    Rouquette, Laura; Stalport, Fabien; Cottin, Hervé; Coll, Patrice; Szopa, Cyril; Saiagh, Kafila; Poch, Olivier; Khalaf, Diana; Chaput, Didier; Grira, Katia; Chaouche, Naila; Dequaire, Tristan

    2016-10-01

    The detection and identification of organic molecules on Mars are of prime importance, as some of these molecules are life precursors and components. While in situ planetary missions are searching for them, it is essential to understand how organic molecules evolve and are preserved at the surface of Mars. Indeed the harsh conditions of the environment of Mars such as ultraviolet (UV) radiation or oxidative processes could explain the low abundance and diversity of organic molecules detected by now.The EXPOSE R2 facility has been placed in low Earth orbit (LEO) under solar radiation, outside the International Space Station (ISS) in 2014. One of the EXPOSE R2 experiment, called PSS (Photochemistry on the Space Station), is dedicated to astrobiology- and astrochemistry-related studies. Part of PSS samples have been dedicated to the study of the evolution of organic molecules under Mars-like surface radiation conditions. Indeed, UV radiation above 200 nm reaches the surface of Mars and could degrade organic matter. Organic samples have been exposed directly to the Sun under KBr filters (>200 nm) from November 2014 to February 2016, mimicking the UV radiation conditions of the surface of Mars. Four types of samples were exposed as thin layers of solid molecules: adenine, adenine with nontronite (a kind of clay mineral detected on Mars), chrysene and glycine with nontronite.To characterize the evolution of our samples under irradiation, infrared (IR) transmission analyses were performed, before the launch of EXPOSE R2 to the ISS in 2014, and after the exposure in space and the return on Earth, this year. These analyses allowed determining whether each molecule is preserved or photodegraded, and if so, its photolysis rate. The effect of nontronite on organic molecules preservation has been investigated as well. We also compared these results from LEO with laboratory data, obtained by irradiating organic samples under a UV lamp.

  20. The AMINO experiment: exposure of amino acids in the EXPOSE-R experiment on the International Space Station and in laboratory

    NASA Astrophysics Data System (ADS)

    Bertrand, Marylène; Chabin, Annie; Colas, Cyril; Cadène, Martine; Chaput, Didier; Brack, Andre; Cottin, Herve

    2015-01-01

    In order to confirm the results of previous experiments concerning the chemical behaviour of organic molecules in the space environment, organic molecules (amino acids and a dipeptide) in pure form and embedded in meteorite powder were exposed in the AMINO experiment in the EXPOSE-R facility onboard the International Space Station. After exposure to space conditions for 24 months (2843 h of irradiation), the samples were returned to the Earth and analysed in the laboratory for reactions caused by solar ultraviolet (UV) and other electromagnetic radiation. Laboratory UV exposure was carried out in parallel in the Cologne DLR Center (Deutsches Zentrum für Luft und Raumfahrt). The molecules were extracted from the sample holder and then (1) derivatized by silylation and analysed by gas chromatography coupled to a mass spectrometer (GC-MS) in order to quantify the rate of degradation of the compounds and (2) analysed by high-resolution mass spectrometry (HRMS) in order to understand the chemical reactions that occurred. The GC-MS results confirm that resistance to irradiation is a function of the chemical nature of the exposed molecules and of the wavelengths of the UV light. They also confirm the protective effect of a coating of meteorite powder. The most altered compounds were the dipeptides and aspartic acid while the most robust were compounds with a hydrocarbon chain. The MS analyses document the products of reactions, such as decarboxylation and decarbonylation of aspartic acid, taking place after UV exposure. Given the universality of chemistry in space, our results have a broader implication for the fate of organic molecules that seeded the planets as soon as they became habitable as well as for the effects of UV radiation on exposed molecules at the surface of Mars, for example.