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Sample records for efecto del parathion

  1. Parathion

    Integrated Risk Information System (IRIS)

    Parathion ; CASRN 56 - 38 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects

  2. Methyl parathion

    Integrated Risk Information System (IRIS)

    Methyl parathion ; CASRN 298 - 00 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  3. Reductive transformation of parathion and methyl parathion by Bacillus sp.

    PubMed

    Yang, Chao; Dong, Ming; Yuan, Yulan; Huang, Yao; Guo, Xinmin; Qiao, Chuanling

    2007-03-01

    Based on the results of phenotypic features, phylogenetic similarity of 16S rRNA gene sequences and BIOLOG test, a soil bacterium was identified as Bacillus sp. DM-1. Using either growing cells or a cell-free extract, it transformed parathion and methyl parathion to amino derivatives by reducing the nitro group. Pesticide transformation by a cell-free extract was specifically inhibited by three nitroreductase inhibitors, indicating the presence of nitroreductase activity. The nitroreductase activity was NAD(P)H-dependent, O(2)-insensitive, and exhibited the substrate specificity for parathion and methyl parathion. Reductive transformation significantly decreased the toxicity of pesticides.

  4. Parathion Poisoning from Flannelette Sheets

    PubMed Central

    Anderson, L. S.; Warner, D. L.; Parker, J. E.; Bluman, N.; Page, B. D.

    1965-01-01

    Two small boys were admitted to the Lions Gate Hospital in coma and acute respiratory distress. They improved and the first boy was sent home; after two nights he was back in hospital in a worsened state. Poisoning with organic phosphate was suspected, and after investigation some flannelette sheets were taken from his home for testing. They proved to have been contaminated with parathion (“nerve gas”) in the hold of a ship sailing from Antwerp to Vancouver; the parathion had been offloaded in California. The remainder of the sheets were traced. The symptomatology and treatment of organic phosphate ester poisoning and the chemical testing of parathion are discussed. PMID:14272498

  5. Extensión del Formalismo de Orbitales de Defecto Cuántico al tratamiento del efecto Stark (SQDO).

    NASA Astrophysics Data System (ADS)

    Menéndez, J. M.; Martín, I.; Velasco, A. M.

    El estudio experimental de las interacciones de átomos Rydberg altamente excitados con campos eléctricos ha experimentado un creciente interés durante las dos últimas décadas debido, en gran medida, al desarrollo de nuevas técnicas para crear y estudiar átomos Rydberg en el laboratorio. Acompañando a estas nuevas técnicas experimentales, es necesario el desarrollo de modelos teóricos que nos permitan contrastar sus medidas y conocer mejor los fundamentos de los mismos. Desde el punto de vista teórico el conocimiento del desdoblamiento de los niveles energéticos de un átomo en función de la magnitud del campo eléctrico aplicado (lo que se conoce como mapa Stark) es el mejor punto de partida para la descripción del sistema y un prerrequisito fundamental para el cálculo de distintas propiedades atómicas en presencia del campo eléctrico tales como intensidades de transición, umbrales de ionización de campo eléctrico, tiempos de vida, posición y anchura de cruces evitados, etc. En este trabajo presentamos la adaptación del método de orbitales de defecto cuántico [1,2,3] al tratamiento del efecto Stark (SQDO) [4] y su aplicación al cálculo de los desdoblamientos energéticos y fuerzas de oscilador de estados Rydberg en los átomos de Li, Na y K. El propósito de este estudio es, por un lado, desarrollar métodos fiables para la determinación de propiedades atómicas en presencia de campos eléctricos y, por otro, mostrar la fiabilidad de las funciones de onda QDO en la descripción del efecto Stark en sistemas atómicos.

  6. Parathion poisoning of Mississippi kites in Oklahoma

    USGS Publications Warehouse

    Franson, J. Christian

    1994-01-01

    Parathion(phosphorothioic acid O, O-diethyl O-[4-nitrophenyl] ester) is a broad spectrum organophosphorus insecticide, used on a variety of crops and occasionally for mosquito control, and is highly toxic to birds (Smith 1987). Intentional poisoning with parathion is reported to have killed more than 8000 red-winged blackbirds (Agelaius phoeniceus), common grackles (Quiscalus quiscula), brown-headed cowbirds (Molothrus ater) and European starlings (Sturnus vulgaris) in two separate instances (Stone et al. 1984). Use of parathion on wheat fields has resulted in the mortality of about 1600 Canada geese (Branta canadensis) and other waterfowl in one instance (White et al. 1982) and about 200 Canada geese in another (Flickinger et al. 1991). More than 200 laughing gulls (Larus atricilla) died near cotton fields treated with parathion (White et al. 1979). Secondary poisoning of raptors resulting from the consumption of prey exposed to parathion, has been reported experimentally and in the field. Stone et al. (1984) found two dead red-tailed hawks (Buteo jamaicensis), a Cooper's hawk (Accipiter cooperii) and an American kestrel (Falco sparverius) that had fed on blackbirds killed by parathion. One of four American kestrels died after being fed cricket frogs (Acris crepitans) that had been exposed to 10ppm parathion for 96 hr (Fleming et al. 1982). The Mississippi kite (Ictinia mississippensis) is highly insectivorous (Brown and Amadon 1968) and is thus subject to secondary poisoning resulting from consumption of insects exposed to pesticides. I report here an instance of secondary parathion poisoning in wild Mississippi kites.

  7. Modelo analítico del efecto de PRS sobre satélites GPS

    NASA Astrophysics Data System (ADS)

    Meza, A.; Brunini, C.; Usandivaras, J. C.

    El sistema GPS (Global Position System) es, hoy en día, la herramienta de navegación y posicionamiento más potente y lo será sin duda en la próxima década. Gran parte de su valiosa utilidad se debe a la alta precisión que permite lograr y ésta, a su vez, depende, entre otras causas, de la precisión con que se conocen las órbitas de los satélites. La presión de radiación solar (PRS) fija el límite de la precisión con que pueden calcularse en la actualidad las efemérides satelitarias. El objetivo de este trabajo es proponer una mejor resolución de este fenómeno. El modelo analítico aquí presentado, se basa en el análisis del comportamiento de los residuos de un ajuste por mínimos cuadrados en el que se utiliza el modelo de PRS propuesto por Beutler. El mismo consiste en un modelo determinista del fenómeno con dos parámetros libres. Los resultados obtenidos ponen de manifiesto que, aún después de aplicar dichos parámetros, prevalecen en los residuos efectos semidiurnos en las componentes radial,tangencial y normal. Estos resultados obtenidos se comparan con los de un trabajo desarrollado por el Instituto de Berne (Beutler et al., 1994), en el que se utilizaron como pseudo-observaciones las órbitas precisas del IGS (CODE). El intervalo de integración escogido por este centro fueron las semanas 680 y 681. En resumen se tienen arcos de 14 días para todos los satélites, donde las efemérides precisas de los mismos para los 14 días fueron utilizados como pseudo-observaciones. El modelo de fuerza que empleó dicho centro fue básicamente el tradicional en lo que respecta al modelo de las fuerzas gravitacionales, y para la PRS utilizo el modelo standard de Beutler. Los parámetros de este modelo junto con las 6 condiciones iniciales (posición y velocidad) fueron ajustados por el método general de mínimos cuadrados. Los residuos en la componente radial, tangencial y normal, para los satélites con un buen comportamiento, presentan una

  8. Chemodynamics of Methyl Parathion and Ethyl Parathion: Adsorption Models for Sustainable Agriculture

    PubMed Central

    Rafique, Uzaira; Balkhair, Khaled S.; Ashraf, Muhammad Aqeel

    2014-01-01

    The toxicity of organophosphate insecticides for nontarget organism has been the subject of extensive research for sustainable agriculture. Pakistan has banned the use of methyl/ethyl parathions, but they are still illegally used. The present study is an attempt to estimate the residual concentration and to suggest remedial solution of adsorption by different types of soils collected and characterized for physicochemical parameters. Sorption of pesticides in soil or other porous media is an important process regulating pesticide transport and degradation. The percentage removal of methyl parathion and ethyl parathion was determined through UV-Visible spectrophotometer at 276 nm and 277 nm, respectively. The results indicate that agricultural soil as compared to barren soil is more efficient adsorbent for both insecticides, at optimum batch condition of pH 7. The equilibrium between adsorbate and adsorbent was attained in 12 hours. Methyl parathion is removed more efficiently (by seven orders of magnitude) than ethyl parathion. It may be attributed to more available binding sites and less steric hindrance of methyl parathion. Adsorption kinetics indicates that a good correlation exists between distribution coefficient (Kd) and soil organic carbon. A general increase in Kd is noted with increase in induced concentration due to the formation of bound or aged residue. PMID:24689059

  9. Chemodynamics of methyl parathion and ethyl parathion: adsorption models for sustainable agriculture.

    PubMed

    Tabassum, Noshabah; Rafique, Uzaira; Balkhair, Khaled S; Ashraf, Muhammad Aqeel

    2014-01-01

    The toxicity of organophosphate insecticides for nontarget organism has been the subject of extensive research for sustainable agriculture. Pakistan has banned the use of methyl/ethyl parathions, but they are still illegally used. The present study is an attempt to estimate the residual concentration and to suggest remedial solution of adsorption by different types of soils collected and characterized for physicochemical parameters. Sorption of pesticides in soil or other porous media is an important process regulating pesticide transport and degradation. The percentage removal of methyl parathion and ethyl parathion was determined through UV-Visible spectrophotometer at 276 nm and 277 nm, respectively. The results indicate that agricultural soil as compared to barren soil is more efficient adsorbent for both insecticides, at optimum batch condition of pH 7. The equilibrium between adsorbate and adsorbent was attained in 12 hours. Methyl parathion is removed more efficiently (by seven orders of magnitude) than ethyl parathion. It may be attributed to more available binding sites and less steric hindrance of methyl parathion. Adsorption kinetics indicates that a good correlation exists between distribution coefficient (Kd) and soil organic carbon. A general increase in Kd is noted with increase in induced concentration due to the formation of bound or aged residue.

  10. Parathion alters incubation behavior of laughing gulls

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Hill, E.F.

    1983-01-01

    One member of each pair of incubating laughing gulls at 9 nests was trapped, orally dosed with either 6 mg/kg parathion in corn oil or corn oil alone, and marked about the neck with red dye. Each nest was marked with a numbered stake and the treatment was recorded. A pilot study with captive laughing gulls had determined the proper dosage of parathion that would significantly inhibit their brain AChE activity (about 50% of normal) without overt signs of poisoning. After dosing, birds were released and the nests were observed for 2 1/2 days from a blind on the nesting island. The activities of the birds at each marked nest were recorded at 10-minute intervals. Results indicated that on the day of treatment there was no difference (P greater than 0.05, Chi-square test) in the proportion of time spent on the nest between treated and control birds. However, birds dosed with 6 mg/kg parathion spent significantly less time incubating on days 2 and 3 than did birds receiving only corn oil. By noon on the third day, sharing of nest duties between pair members in the treated group had approached normal, indicating recovery from parathion intoxication. These findings suggest that sublethal exposure of nesting birds to an organophosphate (OP) insecticide, such as parathion, may result in decreased nest attentiveness, thereby making the clutch more susceptible to predation or egg failure. Behavioral changes caused by sublethal OP exposure could be especially detrimental in avian species where only one pair member incubates or where both members are exposed in species sharing nest duties.

  11. Methyl parathion hydrolase based nanocomposite biosensors for highly sensitive and selective determination of methyl parathion.

    PubMed

    Chen, Shizhen; Huang, Jing; Du, Dan; Li, Jinlin; Tu, Haiyang; Liu, Deli; Zhang, Aidong

    2011-07-15

    This article reports the fabrication of a nanocomposite biosensor for the sensitive and specific detection of methyl parathion. The nanocomposite sensing film was prepared via the formation of gold nanoparticles on silica particles, mixing with multiwall carbon nanotubes and subsequent covalent immobilization of methyl parathion hydrolase. The composite of the individual materials was finely tuned to offer the sensing film with high specific surface area and high conductivity. A significant synergistic effect of nanocomposites on the biosensor performance was observed in biosensing methyl parathion. The square wave voltammetric responses displayed well defined peaks, linearly proportional to the concentrations of methyl parathion in the range from 0.001 μg mL⁻¹ to 5.0 μg mL⁻¹ with a detection limit of 0.3 ng mL⁻¹. The application of this biosensor in the analysis of spiked garlic samples was also evaluated. The proposed protocol can be used as a platform for the simple and fast construction of biosensors with good performance for the determination of enzyme-specific electroactive species.

  12. Parathion utilization by bacterial symbionts in a chemostat.

    PubMed Central

    Daughton, C G; Hsieh, D P

    1977-01-01

    A continuous-culture device was used to select and enrich for microorganisms, from sewage and agricultural runoff, that were capable of using the organophosphorus insecticide parathion as a sole growth substrate. Parathion was dissimilated by the highly acclimated symbiotic activities of Pseudomonas stutzeri, which non-oxidatively and cometabolically hydrolyzed the parathion to ionic diethyl thiophosphate and p-nitrophenol, and P. aeruginosa, which utilized the p-nitrophenol as a sole carbon and energy source. Ionic diethyl thiophosphate was found to be inert to any transformations. Methyl parathion was dissimilated in an analogous way. The device functioned as a chemostat with parathion as the growth-limiting nutrient, and extraordinarily high dissimilation rates were attained for parathion (8 g/liter per day) and for p-nitrophenol (7 g/liter per day). This is the first report of parathion utilization by a defined microbial culture and by symbiotic microbial attack and of dissimilation of an organophosphorus pesticide in a chemostat. PMID:410368

  13. Covalent fabrication of methyl parathion hydrolase on gold nanoparticles modified carbon substrates for designing a methyl parathion biosensor.

    PubMed

    Liu, Guozhen; Guo, Wenqi; Yin, Zhang

    2014-03-15

    A biosensor based on AuNP modified GC electrodes has been developed for direct detection of methyl parathion. AuNP can be introduced to mixed monolayers of aryldiazonium salt modified GC electrodes by Au-C bonding through aryldiazonium salt chemistry, which provides a stable interface showing efficient electron transfer between biomolecules and electrodes. PEG molecules were introduced to the interface to resist non-specific protein adsorption. AuNP surfaces were further modified with 4-carboxyphenyl followed by covalent immobilization of methyl parathion hydrolase (MPH), a specific biocatalytic enzyme to methyl parathion. Exposure of this interface to methyl parathion resulted in a change in amperometric signal due to the MPH catalytic hydrolysis of methyl parathion producing electroactive compound 4-nitrophenol. This biosensor shows high selectivity, specificity, reproducibility and stability, and is functional for the detection of methyl parathion in real samples. The linear range for detection of methyl parathion is 0.2-100 ppb with a detection limit of 0.07 ppb in 0.1M phosphate buffer at pH 7.0.

  14. Genetic surface-display of methyl parathion hydrolase on Yarrowia lipolytica for removal of methyl parathion in water.

    PubMed

    Wang, Xing-Xing; Chi, Zhe; Ru, Shao-Guo; Chi, Zhen-Ming

    2012-09-01

    In this study, the mph gene encoding methyl parathion hydrolase from Pseudomonas sp. WBC-3 was expressed in Yarrowia lipolytica and the expressed methyl parathion hydrolase was displayed on cell surface of Y. lipolytica. The activity of methyl parathion hydrolase displayed on the yeast cells of the transformant Z51 was 59.5 U mg⁻¹ of cell dry cells (450.6 U per mL of the culture) in the presence of 5.0 mM of Co²⁺. The displayed methyl parathion hydrolase had the optimal pH of 9.5 and the optimal temperature of 40 °C, respectively and was stable in the pH range of 4.5-11 and up to 40 °C. The displayed methyl parathion hydrolase was also stimulated by Co²⁺, Cu²⁺, Ni²⁺ and Mn²⁺, and was not affected by Fe²⁺, Fe³⁺, Na⁺, K⁺, Ca²⁺ and Zn²⁺, but was inhibited by other cations tested. Under the optimal conditions (OD(600 nm) = 2.6, the substrate concentration = 100 mg L⁻¹ and 40 °C), 90.8 % of methyl parathion was hydrolyzed within 30 min. Under the similar conditions, 98.7, 97.0, 96.5 and 94.4 % of methyl parathion in tap water (pH 9.5), tap water (pH 6.8), seawater (pH 9.5) and natural seawater (pH 8.2) were hydrolyzed, respectively, suggesting that the methyl parathion hydrolase displayed on the yeast cells can effectively remove methyl parathion in water.

  15. A colorimetric assay for determination of methyl parathion using recombinant methyl parathion hydrolase.

    PubMed

    Anh, Dau Hung; Cheunrungsikul, Kritsananporn; Wichitwechkarn, Jesdawan; Surareungchai, Werasak

    2011-05-01

    A simple, rapid and sensitive colorimetric dipstick assay for the detection of the organophosphorous insecticide methyl parathion (MPT) residue in vegetables was developed. The assay was based on the hydrolysis of MPT by a recombinant methyl parathion hydrolase (recMPH), the encoding gene of which was isolated from Burkholderia cepacia, a soil bacterium indigenous to Thailand. This reaction generates protons leading to a change in pH that correlates with the amount of MPH present. Hence, the pH indicator bromothymol blue was used to monitor the MPH hydrolysis as the associated color changes can be observed by the naked eye. The recMPH was immobilized on a PVDF membrane to establish a dipstick assay format. The assays could detect MPT residues in spiked vegetable samples at the concentration of 1 mg/L without using analytical instrumentation. The test is reusable and stable for up to 3 months in the absence of any preservatives.

  16. External and internal exposure of wine growers spraying methyl parathion.

    PubMed

    Muttray, Axel; Bäcker, Gerhard; Jung, Detlev; Hill, Georg; Letzel, Stephan

    2006-04-10

    Organophosphates, used in agriculture, are readily absorbed through the skin. We investigated the relationship between dermal and inhalative methyl parathion exposure and the plasma levels. Twenty-three healthy wine growers sprayed the insecticide for 50 min. Fluorescent brilliant sulfoflavin was added to the spraying fluids and filter papers were fixed on the subjects. The filter papers were used to evaluate the amount of brilliant sulfoflavine on the unprotected skin fluorometrically. Inhalative exposure was measured with personal air sampler. Plasma concentrations of methyl parathion and its metabolite methyl paraoxon were determined with gas chromatography. Cholinesterase activity in serum and erythrocytes was measured before and after exposure. Some wine growers wore protective clothes, none protective gloves. Dermal exposure ranged up to 12,044 microg, inhalative to 22 microg. Maximum plasma concentration of methyl parathion was 12.1 microg/l. Methyl paraoxon was not detectable. Cholinesterase activity did not decrease. Dermal exposure correlated with the methyl parathion plasma level (Spearman's rho=0.72, p<0.001). In conclusion, dermal exposure exceeded inhalative exposure considerably. Measuring dermal deposition with the brilliant sulfoflavin technique may provide a good estimate of the internal load with methyl parathion. Preventive measures should be improved as toxic effects of repeated exposure to low doses of methyl parathion cannot be excluded.

  17. La utilizacion de los mapas conceptuales en la ensenanza de biologia y su efecto sobre el dominio del proceso de fotosintesis en los estudiantes universitarios

    NASA Astrophysics Data System (ADS)

    Gonzalez Rivera, Maria M.

    Se investigo el efecto de los mapas conceptuales sobre el dominio del proceso de fotosintesis en estudiantes universitarios. La investigacion utilizo dos estrategias: mapas conceptuales individuales y mapas conceptuales colaborativos, con el fin de investigar si existen diferencias significativas en el dominio del proceso de fotosintesis. El analisis de los datos incluyo aspectos cualitativos y cuantitativos. Se desprende del estudio que el 80% de los estudiantes describen la utilizacion de los mapas conceptuales como una experiencia beneficiosa. El 70% de los estudiantes expreso que los mapas conceptuales son utiles en el aprendizaje del proceso de fotosintesis y el 61% indico que facilitan la comprension de los conceptos. Los hallazgos mas importantes del analisis cuantitativo indican que los estudiantes que utilizaron los mapas conceptuales mejoraron significativamente su desempeno en la posprueba global. Se utilizo la prueba Mann-Whitney para investigar si existian diferencias significativas en la posprueba y preprueba global, el valor de W = 1945.0, para un valor p de 0.00, lo cual establece diferencias significativas. Para determinar si existian diferencias significativas entre la posprueba y preprueba del grupo individual, se realizo la prueba nuevamente. El valor de W correspondio a 490.5, que es significativo, con un valor p de 0.00. Se concluye que existen diferencias significativas entre la ejecucion de la posprueba y preprueba del grupo individual. Los datos proveen suficiente evidencia para sostener que los estudiantes que utilizaron la estrategia de mapas conceptuales individuales mejoraron el dominio del proceso de fotosintesis significativamente. Se realizo nuevamente la prueba para los resultados de posprueba y preprueba del grupo colaborativo. El valor de W correspondio a 446 con un valor p de 0.00. Se concluyo que existen diferencias significativas entre la ejecucion de la posprueba y preprueba del grupo colaborativo. Finalmente, se efectuo una

  18. Biotransformation of the insecticide parathion by mouse brain.

    PubMed

    Soranno, T M; Sultatos, L G

    1992-01-01

    The acute toxicity of organothiophosphate insecticides like parathion results from their metabolic activation by cytochromes P450. The present study is directed towards the characterization of cytochrome-P450-dependent metabolism of parathion by various mouse brain regions. Intraperitoneal administration of [35S]parathion to mice led to covalently bound [35S]sulfur in various tissues, indicating their capacity to oxidatively desulfurate this insecticide. Liver contained the greatest amount of covalently bound sulfur, and brain the least. Among individual brain regions the olfactory bulb and hypothalamus possessed the highest levels of sulfur binding when expressed on a per milligram tissue basis. However, when expressed on a per brain region basis, sulfur binding was greatest within the cortex as a result of the large mass of this region, compared to the hypothalamus and olfactory bulb. Incubation of the 78,000 x g fraction of mouse brain with parathion resulted in formation of p-nitrophenol, although paraoxon could not be detected. However, given the current understanding of parathion metabolism by cytochromes P450, and given that paraoxon can rapidly disappear through phosphorylation of serine hydroxyl groups, it is reasonable to assume that at least some paraoxon was formed. Production of p-nitrophenol required NADPH and was inhibited by carbon monoxide. In vitro incubations of parathion with the 78,000 x g fraction of mouse brain indicated that the hypothalamus and olfactory bulb had the greatest capacity to produce p-nitrophenol. These results demonstrate that various mouse brain regions possess different capacities to metabolize parathion.

  19. DDE increased the toxicity of parathion to coturnix quail

    USGS Publications Warehouse

    Ludke, J.L.

    1977-01-01

    Adult male Japanese quail (Coturnix coturnix) were exposed to DDE or chlordane in the diet and subsequently dosed with parathion or paraoxon. Pretreatment with 5 or 50 ppm DDE in the diet for 12 weeks resulted in increased cholinesterase (ChE) activity in plasma, but not in the brain. Dietary concentrations of 5 and 50 ppm DDE caused increased susceptibility of quail that were challenged with parathion or paraoxon. The increased mortality resulting from DDE pretreatment was reflected in brain ChE inhibition. The synergistic action of DDE was apparent after 3 days of exposure to 50 ppm DDE and 1 week of exposure to 5 ppm DDE. Birds exposed for 3 weeks to 5 or 50 ppm DDE retained their DDE-potentiated sensitivity to parathion after 2 weeks on clean diet. Chlordane pretreatment resulted in decreased susceptibility (antagonism) to parathion, but not to paraoxon dosage. Implications of differing responses in ChE and mortality among controls, DDE-, and chlordane-pretreated birds after parathion or paraoxon dosage are discussed.

  20. Acute responses of American kestrels to methyl parathion and fenvalerate

    USGS Publications Warehouse

    Rattner, B.A.; Franson, J.C.

    1984-01-01

    Physiological and toxicological effects of p.o, methyl parathion (0.375-3.0 mg/kg) or fenvalerate (1000-4000 mg/kg) were examined over a 10 h period in American kestrels (Falco sparverius) maintained in thermoneutral (22?.C) and cold (-5?.C) environments. Methyl parathion was highly toxic (LD50=3.08 mg/kg, 95% confidence limits=2.29-4.l4 mg/kg, producing overt intoxication (abnormal posture, ataxia, paresis), dose-dependent inhibition (26-67%) of brain acetylcholinesterase activity, hyperglycemia, and elevated plasma corticosterone concentration. Transient but pronounced hypothermia was associated with plasma cholinesterase inhibition in excess of 50% (2 h after intubation), although this response was highly variable (plasma ChE inhibition vs. A cloacal temperature, r=-0.60). Fenvalerate, at doses far exceeding those encountered in the environment, caused mild intoxication (irregular head movement) and elevated plasma alanine aminotransferase activity, but did not alter cloacal temperature, plasma activities of CK, U-HBDH, and LDK, or concentrations of corticosterone, glucose, triiodothyronine, and uric acid. Cold exposure intensified methyl parathion toxicity, but did not affect that of fenvalerate. It would thus appear that the organophosphorus insecticide methyl parathion poses far greater hazard than the pyrethroid fenvalerate to raptorial birds.

  1. Interaction of ethanol and the organophosphorus insecticide parathion.

    PubMed

    O'Shaughnessy, J A; Sultatos, L G

    1995-11-27

    Phosphorothioate insecticides such as parathion (O,O-diethyl-O-p-nitrophenyl phosphorothioate) undergo P450-dependent oxidative desulfuration, leading to both activation and detoxification of these compounds. Consequently, alterations in P450-dependent oxidative desulfuration may affect the acute toxicities of these insecticides. In the present study, pretreatment of mice with 15% ethanol in the drinking water for 6 days antagonized the acute toxicity of parathion, but not its toxic metabolite paraoxon (O,O-diethyl-O-p-nitrophenyl phosphate), suggesting that ethanol affected the oxidative desulfuration of this insecticide. The presence of ethanol within hepatic microsomal incubations did not alter the P450-dependent formation of paraoxon (activation) and p-nitrophenol (detoxification), although p-nitrophenol levels were increased in the presence of ethanol as a result of inhibition of its biotransformation to 4-nitrocatechol by CYP2E1. Ethanol exposure reduced hepatic pyruvate levels, but had no effect on levels of lactate, isocitrate, alpha-ketoglutarate, and malate. Calculation of cytosolic NAD+/NADH and cytosolic NADP+/NADPH redox ratios did not reveal any detectable difference in redox state between control and ethanol-treated mice. Since ethanol did not alter directly the P450-dependent activation or detoxification of parathion, and did not decrease NADPH levels, ethanol's antagonism of the acute toxicity of parathion may result from reduced availability of O2.

  2. Accumulation, metabolism and toxicity of parathion in tadpoles

    SciTech Connect

    Hall, R.J. )

    1990-04-01

    Earlier work exposing tadpoles to organophosphorus pesticides indicated the great resistance of tadpoles of the bullfrog (Rana catesbeiana) to these chemicals and their surprising ability to accumulate parathion and fenthion from water. These qualities seemed to make them an ideal model with which to test a hypothesis advanced by Burke and Ferguson, who noted that parathion is more toxic to resistant mosquitofish in static water than in flowing water--a reversal of the pattern normally seen. They believed that highly toxic metabolite paraoxon was produced by the fish and that its buildup in static systems resulted in the unexpected mortality. Amphibians have been shown to produce paraoxon and to accumulate the parent compound parathion to levels that are potentially hazardous to other organisms. In the course of examining paraoxon production by tadpoles, it would also be possible to learn more about their patterns of parathion uptake and elimination. Retention of residues is also a matter of concern given the high levels observed in the earlier studies.

  3. Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication.

    PubMed

    Jan, Yi-Hua; Richardson, Jason R; Baker, Angela A; Mishin, Vladimir; Heck, Diane E; Laskin, Debra L; Laskin, Jeffrey D

    2015-10-01

    Parathion, a widely used organophosphate insecticide, is considered a high priority chemical threat. Parathion toxicity is dependent on its metabolism by the cytochrome P450 system to paraoxon (diethyl 4-nitrophenyl phosphate), a cytotoxic metabolite. As an effective inhibitor of cholinesterases, paraoxon causes the accumulation of acetylcholine in synapses and overstimulation of nicotinic and muscarinic cholinergic receptors, leading to characteristic signs of organophosphate poisoning. Inhibition of parathion metabolism to paraoxon represents a potential approach to counter parathion toxicity. Herein, we demonstrate that menadione (methyl-1,4-naphthoquinone, vitamin K3) is a potent inhibitor of cytochrome P450-mediated metabolism of parathion. Menadione is active in redox cycling, a reaction mediated by NADPH-cytochrome P450 reductase that preferentially uses electrons from NADPH at the expense of their supply to the P450s. Using human recombinant CYP 1A2, 2B6, 3A4 and human liver microsomes, menadione was found to inhibit the formation of paraoxon from parathion. Administration of menadione bisulfite (40mg/kg, ip) to rats also reduced parathion-induced inhibition of brain cholinesterase activity, as well as parathion-induced tremors and the progression of other signs and symptoms of parathion poisoning. These data suggest that redox cycling compounds, such as menadione, have the potential to effectively mitigate the toxicity of organophosphorus pesticides including parathion which require cytochrome P450-mediated activation.

  4. Protective effects of vitamins C and E against hepatotoxicity induced by methyl parathion in rats.

    PubMed

    Uzunhisarcikli, Meltem; Kalender, Yusuf

    2011-10-01

    Male rats were given vitamins C+E, methyl parathion, or both daily via gavage for seven weeks. Body weight was decreased while liver weight increased significantly at the end of fourth and seventh weeks in the methyl parathion- and methyl parathion plus vitamin-treated groups. Serum total protein, albumin, triglyceride, low density lipoprotein-cholesterol (VLDL-cholesterol) levels decreased, and serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl-transferase (GGT), lactate dehydrogenase (LDH), and total cholesterol levels increased significantly in the methyl parathion- and the methyl parathion plus vitamin-treated rats. There was a statistically significant difference for all biochemical parameters when the methyl parathion plus vitamin-treated group was compared with methyl parathion-treated group. In electron microscopic investigation, cytopathological alterations were observed in hepatocytes of the methyl parathion- and the methyl parathion plus vitamin-treated rats. As a result, methyl parathion-induced hepatotoxicity is reduced by vitamins C+E, but vitamins C+E did not provide complete protection.

  5. Isolation of Methyl Parathion-Degrading Strain M6 and Cloning of the Methyl Parathion Hydrolase Gene

    PubMed Central

    Zhongli, Cui; Shunpeng, Li; Guoping, Fu

    2001-01-01

    A degradative bacterium, M6, was isolated and presumptively identified as Plesiomonas sp. strain M6 was able to hydrolyze methyl parathion to p-nitrophenol. A novel organophosphate hydrolase gene designated mpd was selected from its genomic library prepared by shotgun cloning. The nucleotide sequence of the mpd gene was determined. The gene could be effectively expressed in Esherichia coli. PMID:11571204

  6. Hormonal responses and tolerance to cold of female quail following parathion ingestion

    USGS Publications Warehouse

    Rattner, B.A.; Sileo, L.; Scanes, C.G.

    1982-01-01

    Thirty-week-old female bobwhite quail (Colinus virginianus), maintained at 26 + 1?C, were provided diets containing 0,25, or 100 ppm parathion ad libitum. After 10 days, birds were exposed to mild cold (6 + 1?C) for 4,8, 12, 24, or 48 hr. Brain acetylcholinesterase activity was inhibited in a dose-dependent manner in birds receiving 25 and 100 ppm parathion. Body weight, egg production, and plasma luteinizing hormone and progesterone concentrations were reduced in birds receiving 100 ppm parathion compared with other groups. Cold exposure did not alter plasma corticosterone levels in the 0- and 25-ppm parathion groups, but a two- to five fold elevation of plasma corticosterone was observed in birds fed 100 ppm parathion. These findings indicate that (i) short-term ingestion of parathion can impair reproduction possibly by altering gonadotropin or steroid secretion, and (ii) tolerance to cold may be reduced following ingestion of this organophosphate.

  7. Poisoning of Canada geese in Texas by parathion sprayed for control of Russian wheat aphid

    USGS Publications Warehouse

    Flickinger, Edward L.; Juenger, Gary; Roffe, Thomas J.; Smith, Milton R.; Irwin, Roy J.

    1991-01-01

    Approximately 200 Canada geese (Branta canadensis) died at a playa lake in the Texas Panhandle shortly after a winter wheat field in the basin adjacent to the lake was treated with parathion to control newly invading Russian wheat aphids (Diuraphis noxia). No evidence of infectious disease was diagnosed during necropsies of geese. Brain ChE activities were depressed up to 77% below normal. Parathion residues in GI tract contents of geese ranged from 4 to 34 ppm. Based on this evidence, parathion was responsible for the goose mortalities. Parathion applications to winter wheat will undoubtedly increase if parathion is applied for control of both Russian wheat aphids and greenbugs (Schizaphis graminum). Geese may potentially be exposed to widespread applications of parathion from fall to spring, essentially their entire wintering period.

  8. Constitutive Androgen Receptor-Null Mice Are Sensitive to the Toxic Effects of Parathion: Association with Reduced Cytochrome P450-Mediated Parathion MetabolismS⃞

    PubMed Central

    Mota, Linda C.; Hernandez, Juan P.

    2010-01-01

    Constitutive androgen receptor (CAR) is activated by several chemicals and in turn regulates multiple detoxification genes. Our research demonstrates that parathion is one of the most potent, environmentally relevant CAR activators with an EC50 of 1.43 μM. Therefore, animal studies were conducted to determine whether CAR was activated by parathion in vivo. Surprisingly, CAR-null mice, but not wild-type (WT) mice, showed significant parathion-induced toxicity. However, parathion did not induce Cyp2b expression, suggesting that parathion is not a CAR activator in vivo, presumably because of its short half-life. CAR expression is also associated with the expression of several drug-metabolizing cytochromes P450 (P450). CAR-null mice demonstrate lower expression of Cyp2b9, Cyp2b10, Cyp2c29, and Cyp3a11 primarily, but not exclusively in males. Therefore, we incubated microsomes from untreated WT and CAR-null mice with parathion in the presence of esterase inhibitors to determine whether CAR-null mice show perturbed P450-mediated parathion metabolism compared with that in WT mice. The metabolism of parathion to paraoxon and p-nitrophenol (PNP) was reduced in CAR-null mice with male CAR-null mice showing reduced production of both paraoxon and PNP, and female CAR-null mice showing reduced production of only PNP. Overall, the data indicate that CAR-null mice metabolize parathion slower than WT mice. These results provide a potential mechanism for increased sensitivity of individuals with lower CAR activity such as newborns to parathion and potentially other chemicals due to decreased metabolic capacity. PMID:20573718

  9. Involvement of Oxidative Stress in Methyl Parathion and Parathion-Induced Toxicity and Genotoxicity to Human Liver Carcinoma (HepG2) Cells

    PubMed Central

    Edwards, Falicia L.; Yedjou, Clement G.; Tchounwou, Paul B.

    2013-01-01

    Methyl parathion (C8H10NO5PS) and parathion (C10H14NO5PS) are both organophosphate insecticides (OPI) widely used for household and agricultural applications. They are known for their ability to irreversibly inhibit acetylcholinesterase which often leads to a profound effect on the nervous system of exposed organisms. Many recently published studies have indicated that human exposure to OPI may be associated with neurologic, hematopoietic, cardiovascular, and reproductive adverse effects. Studies have also linked OPI exposure to a number of degenerative diseases including Parkinson's, Alzheimer's, and amyotrophic lateral sclerosis. Also, oxidative stress (OS) has been reported as a possible mechanism of OPI toxicity in humans. Hence, the aim of the present investigation was to use human liver carcinoma (HepG2) cells as a test model to evaluate the role of OS in methyl parathion- and parathion-induced toxicity. To achieve this goal, we performed the MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] assay for cell viability, lipid peroxidation assay for malondialdehyde (MDA) production, and Comet assay for DNA damage, respectively. Results from MTT assay indicated that methyl parathion and parathion gradually reduce the viability of HepG2 cells in a dose-dependent manner, showing 48 h-LD50 values of 26.20 mM and 23.58 mM, respectively. Lipid peroxidation assay resulted in a significant increase (p<0.05) of MDA level in methyl parathion- and parathion-treated HepG2 cells compared to controls, suggesting that OS plays a key role in OPI-induced toxicity. Comet assay indicated a significant increase in genotoxicity at higher concentrations of OPI exposure. Overall, we found that methyl-parathion is slightly less toxic than parathion to HepG2 cells. The cytotoxic effect of these OPI was found to be associated, at least in part, with oxidative cell/tissue damage. PMID:21544925

  10. Involvement of oxidative stress in methyl parathion and parathion-induced toxicity and genotoxicity to human liver carcinoma (HepG₂) cells.

    PubMed

    Edwards, Falicia L; Yedjou, Clement G; Tchounwou, Paul B

    2013-06-01

    Methyl parathion (C₈H₁₀NO₅PS) and parathion (C₁₀H14 NO₅PS) are both organophosphate insecticides (OPI) widely used for household and agricultural applications. They are known for their ability to irreversibly inhibit acetylcholinesterase which often leads to a profound effect on the nervous system of exposed organisms. Many recently published studies have indicated that human exposure to OPI may be associated with neurologic, hematopoietic, cardiovascular, and reproductive adverse effects. Studies have also linked OPI exposure to a number of degenerative diseases including Parkinson's, Alzheimer's, and amyotrophic lateral sclerosis. Also, oxidative stress (OS) has been reported as a possible mechanism of OPI toxicity in humans. Hence, the aim of the present investigation was to use human liver carcinoma (HepG₂) cells as a test model to evaluate the role of OS in methyl parathion- and parathion-induced toxicity. To achieve this goal, we performed the MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] assay for cell viability, lipid peroxidation assay for malondialdehyde (MDA) production, and Comet assay for DNA damage, respectively. Results from MTT assay indicated that methyl parathion and parathion gradually reduce the viability of HepG₂ cells in a dose-dependent manner, showing 48 h-LD₅₀ values of 26.20 mM and 23.58 mM, respectively. Lipid peroxidation assay resulted in a significant increase (P < 0.05) of MDA level in methyl parathion- and parathion-treated HepG₂ cells compared with controls, suggesting that OS plays a key role in OPI-induced toxicity. Comet assay indicated a significant increase in genotoxicity at higher concentrations of OPI exposure. Overall, we found that methyl-parathion is slightly less toxic than parathion to HepG₂ cells. The cytotoxic effect of these OPI was found to be associated, at least in part, with oxidative cell/tissue damage.

  11. Efecto del Programa de Entrenamiento “Manejo del Dolor” en la Documentación de Enfermería en el Expediente Electrónico

    PubMed Central

    Monsiváis, María Guadalupe Moreno; Guzmán, Ma. Guadalupe Interial; Flores, Paz Francisco Sauceda; Arreola, Leticia Vázquez

    2012-01-01

    Resumen En el presente trabajo se muestra la importancia de entrenar al personal de enfermería para mejorar la documentación en el expediente electrónico. Se eligió el manejo del dolor por ser un área prioritaria; una alta proporción de pacientes en período post operatorio cursa con dolor, por lo tanto, la documentación debe ser útil para la toma de decisiones clínicas. Se implementó un programa de entrenamiento denominado “Manejo del Dolor” dirigido al personal de enfermería. Se utilizó la tecnología de la información como herramienta para fortalecer el conocimiento con base en la revisión sistemática de la literatura; el personal de enfermería participante seleccionó la mejor evidencia; posteriormente se trabajó en la transferencia de este conocimiento a la práctica a través del diseño de un protocolo para el manejo del dolor. Se concluye que el conocimiento del manejo del dolor es fundamental para que enfermería documente con mayor precisión sus intervenciones. PMID:24199106

  12. Bioavailability of methyl parathion adsorbed on clay minerals and iron oxide.

    PubMed

    Cai, Peng; He, Xiaomin; Xue, Aifang; Chen, Hao; Huang, Qiaoyun; Yu, Jun; Rong, Xinming; Liang, Wei

    2011-01-30

    Adsorption, desorption and degradation by Pseudomonas putida of methyl parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) on montmorillonite, kaolinite and goethite were studied. Metabolic activities of methyl parathion-degrading bacteria P. putida in the presence of minerals were also monitored by microcalorimetry to determine the degradation mechanism of methyl parathion. Montmorillonite presented higher adsorption capacity and affinity for methyl parathion than kaolinite and goethite. The percentage of degradation of methyl parathion adsorbed on minerals by P. putida was in the order of montmorillonite>kaolinite>goethite. The presence of minerals inhibited the exponential growth and the metabolic activity of P. putida. Among the examined minerals, goethite exhibited the greatest inhibitory effect on bacterial activity, while montmorillonite was the least depressing. The biodegradation of adsorbed methyl parathion by P. putida is apparently not controlled by the adsorption affinity of methyl parathion on minerals and may be mainly governed by the activity of the methyl parathion-degrading bacteria. The information obtained in this study is of fundamental significance for the understanding of the behavior of methyl parathion in soil environments.

  13. [Terahertz spectroscopic investigation of organophosphorus pesticide parathion-methyl].

    PubMed

    Yan, Zhi-Gang; Zheng, Song; Xie, Qiang-Jun; Zhou, Ze-Kui

    2009-10-01

    The present paper reports the theoretical and experimental vibrational spectra of organophosphorus pesticide parathion-methyl in the frequency range from 0.2 to 2.0 THz respectively. Under the room temperature and nitrogen conditions, the absorption peaks were found at 0.65, 1.33, 1.81 and 1.91 THz, and the average refractive index was 1.39 based on the terahertz time-domain spectroscopy (THz-TDS). In parallel with the experimental study, density functional theory (DFT) was applied to obtain the structure and vibrational frequencies of parathion-methyl in the terahertz region. The calculated results are in reasonable agreement with the experimental data. The absorption features are caused by the collective vibrational and torsional modes, and the different absorption peaks correspond to different vibrational modes.

  14. 75 FR 43981 - Methyl Parathion; Rescision of Previously Issued Order and Issuance of Revised Cancellation Order...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... stakeholders including environmental, human health, and agricultural advocates; the chemical industry... chemicals, and does not specifically refer to this cancellation action for methyl parathion. The second... Rice would like EPA to expedite a replacement chemical for methyl parathion, and would support...

  15. Abiotic degradation of methyl parathion by manganese dioxide: Kinetics and transformation pathway.

    PubMed

    Liao, Xiaoping; Zhang, Caixiang; Liu, Yuan; Luo, Yinwen; Wu, Sisi; Yuan, Songhu; Zhu, Zhenli

    2016-05-01

    Methyl parathion, a widely used insecticide around the world, has aroused gradually extensive concern of researchers due to its degradation product such as methyl paraoxon, with higher toxicity for mammals and more recalcitrant. Given the ubiquity of manganese dioxide (MnO2) in soils and aquatic sediments, the abiotic degradation of methyl parathion by α-MnO2 was investigated in batch experiments. It was found that methyl parathion was decomposed up to 90% by α-MnO2 in 30 h and the removal efficiency of methyl parathion depended strongly on the loading of α-MnO2 and pH value in the solution where the reactions followed pseudo-first-order model well. The coexisting metal ions (such as Ca(2+), Mg(2+) and Mn(2+)) weakened markedly the degradation of methyl parathion by α-MnO2. However, the effect of dissolved organic matter (HA-Na) on reaction rates presented two sides: to improve hydrolysis rate but deteriorate oxidation rate of methyl parathion. Based on the degradation products identified by gas chromatography-mass spectrometer (GC/MS) and liquid chromatography high-resolution mass spectrometer (LC/HRMS), both hydrolysis and oxidation processes were proposed to be two predominant reaction mechanisms contributing to methyl parathion degradation by α-MnO2. This study provided meaningful information to elucidate the abiotic dissipation of methyl parathion by manganese oxide minerals in the environment.

  16. Effects of methyl parathion on Chasmagnathus granulatus hepatopancreas: protective role of sesamol.

    PubMed

    Bianchini, Adalto; Monserrat, José Maria

    2007-05-01

    The protective role of sesamol, an inhibitor of the mixed function oxygenase (MFO) system, against histopathological effects of methyl parathion in the hepatopancreas of the estuarine crab, Chasmagnathus granulatus, was studied. Exposure (72 h) to a sublethal dose (0.05 mg/kg/day; 10% of 72 h-LD50) of injected methyl parathion increased the percentage of damaged hepatopancreatic tubules. Presence of melanin-like deposits in the connective tissue between hepatopancreatic tubules was also observed. Antioxidant enzyme activities (catalase and glutathione S-transferase) and lipid peroxidation (LPO) levels were also increased in hepatopancreas of crabs injected with methyl parathion. Pretreatment with sesamol (0.85 mg/kg/day) significantly protected against all these effects. These findings suggest that the hepatopancreatic damages induced by methyl parathion are due to LPO of hepatopancreatocytes membranes, as a consequence of the oxidative stress generated after methyl parathion oxidative biotransformation mediated by the MFO system.

  17. Parathion degradation and its intermediate formation by Fenton process in neutral environment.

    PubMed

    Fan, Chihhao; Tsui, Lo; Liao, Ming-Chu

    2011-01-01

    The purpose of this study is to investigate parathion degradation by Fenton process in neutral environment. The initial parathion concentration for all the degradation experiments was 20 ppm. For hydrogen ion effect on Fenton degradation, the pH varied from 2 to 8 at the [H₂O₂] to [Fe²(+)] ratio of 2-2 mM, and the result showed pH 3 as the most effective environment for parathion degradation by Fenton process. Apparent degradation was also observed at pH 7. The subsequent analysis for parathion degradation was conducted at pH 7 because most environmental parathion exists in the neutral environment. Comparing the parathion degradation results at various Fenton dosages revealed that at Fe²(+) concentrations of 0.5, 1.0 and 1.5 mM, the Fenton reagent ratio ([H₂O₂]/[Fe²(+)]) for best-removing performance were found as 4, 3, and 2, resulting in the removal efficiencies of 19%, 48% and 36%, respectively. Further increase in Fe²(+) concentration did not cause any increase of the optimum Fenton reagent ratio for the best parathion removal. The result from LC-MS also indicated that hydroxyl radicals might attack the PS double bond, the single bonds connecting nitro-group, nitrophenol, or the single bond within ethyl groups of parathion molecules forming paraoxons, nitrophenols, nitrate/nitrite, thiophosphates, and other smaller molecules. Lastly, the parathion degradation by Fenton process at the presence of humic acids was investigated, and the results showed that the presence of 10 mg L⁻¹ of humic acids in the aqueous solution enhanced the parathion removal by Fenton process twice as much as that without the presence of humic acids.

  18. Modulation of parathion toxicity by glucose feeding: Is nitric oxide involved?

    SciTech Connect

    Liu Jing . E-mail: jing.pope@okstate.edu; Gupta, Ramesh C.; Goad, John T.; Karanth, Subramanya; Pope, Carey

    2007-03-15

    Glucose feeding can markedly exacerbate the toxicity of the anticholinesterase insecticide, parathion. We determined the effects of parathion on brain nitric oxide and its possible role in potentiation of toxicity by glucose feeding. Adult rats were given water or 15% glucose in water for 3 days and challenged with vehicle or parathion (18 mg/kg, s.c.) on day 4. Functional signs, plasma glucose and brain cholinesterase, citrulline (an indicator of nitric oxide production) and high-energy phosphates (HEPs) were measured 1-3 days after parathion. Glucose feeding exacerbated cholinergic toxicity. Parathion increased plasma glucose (15-33%) and decreased cortical cholinesterase activity (81-90%), with no significant differences between water and glucose treatment groups. In contrast, parathion increased brain regional citrulline (40-47%) and decreased HEPs (18-40%) in rats drinking water, with significantly greater changes in glucose-fed rats (248-363% increase and 31-61% decrease, respectively). We then studied the effects of inhibiting neuronal nitric oxide synthase (nNOS) by 7-nitroindazole (7NI, 30 mg/kg, i.p. x4) on parathion toxicity and its modulation by glucose feeding. Co-exposure to parathion and 7NI led to a marked increase in cholinergic signs of toxicity and lethality, regardless of glucose intake. Thus, glucose feeding enhanced the accumulation of brain nitric oxide following parathion exposure, but inhibition of nitric oxide synthesis was ineffective at counteracting increased parathion toxicity associated with glucose feeding. Evidence is therefore presented to suggest that nitric oxide may play both toxic and protective roles in cholinergic toxicity, and its precise contribution to modulation by glucose feeding requires further investigation.

  19. Removal of methyl parathion in water, by Dugesia dorotocephala.

    PubMed

    Amaya-Chávez, A; López-López, E; Galar-Martínez, M; Gómez-Oliván, L M; García-Fabila, M M

    2009-09-01

    The aim of this study was to determine the efficiency of Dugesia dorotocephala on Methyl parathion removal. An initial concentration of 1.25 microg mL(-1) of MeP was used to evaluate the removal capacity of planarian. A first-order removal kinetics was obtained with a disappearance rate constant (k(r)) of 0.49 days(-1) and 69% efficiency on contaminant removal. This is significantly different (p < 0.5) from the degradation occurring in control systems, leading us to conclude that D. dorotocephala effectively removes MeP from contaminated water.

  20. Toxicity of methyl parathion to bats: Mortality and coordination loss

    USGS Publications Warehouse

    Clark, D.R.

    1986-01-01

    The 24-h oral LD50 of methyl parathion (phosphorothioic acid O,O-dimethyl O-(4-nitrophenyl) ester) to little brown bats (Myotis lucifugus) (372 mg/kg) was 8.5 times the LD50 for mice (Mus musculus) (44 mg/kg). However, orally dosed mice either died or appeared behaviorally normal after 2 to 3 h, whereas many dosed bats, although alive at 24 h, could not right themselves when placed on their backs. The oral dose estimated to cause this loss of coordination in 50% of a sample of big brown bats (Eptesicus fuscus) was one-third or less the LD50 of this species. Cholinesterase activity depression in brains of little brown bats was similar whether dosage was oral or dermal. With death as the criterion, bats proved relatively insensitive to methyl parathion in 24-h tests, but considerations of the chemical's potential to cause coordination loss, leading to capture and death by predators, coupled with bats' naturally low reproductive rates, suggest possible injury to exposed bat populations.

  1. Burkholderia jiangsuensis sp. nov., a methyl parathion degrading bacterium, isolated from methyl parathion contaminated soil.

    PubMed

    Liu, Xu-Yun; Li, Chun-Xiu; Luo, Xiao-Jing; Lai, Qi-Liang; Xu, Jian-He

    2014-09-01

    A methyl parathion (MP) degrading bacterial strain, designated MP-1(T), was isolated from a waste land where pesticides were formerly manufactured in Jiangsu province, China. Polyphasic taxonomic studies showed that MP-1(T) is a Gram-stain-negative, non-spore-forming, rod-shaped and motile bacterium. The bacterium could grow at salinities of 0-1 % (w/v) and temperatures of 15-40 °C. Strain MP-1(T) could reduce nitrate to nitrite, utilize d-glucose and l-arabinose, but not produce indole, or hydrolyse gelatin. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that MP-1(T) belongs to the genus Burkholderia, showing highest sequence similarity to Burkholderia grimmiae DSM 25160(T) (98.5 %), and similar strains including Burkholderia zhejiangensis OP-1(T) (98.2 %), Burkholderia choica LMG 22940(T) (97.5 %), Burkholderia glathei DSM 50014(T) (97.4 %), Burkholderia terrestris LMG 22937(T) (97.2 %) and Burkholderia telluris LMG 22936(T) (97.0 %). In addition, the gyrB and recA gene segments of strain MP-1(T) exhibited less than 89.0 % and 95.1 % similarities with the most highly-related type strains indicated above. The G+C content of strain MP-1(T) was 62.6 mol%. The major isoprenoid quinone was ubiquinone Q-8. The predominant polar lipids comprised phosphatidyl ethanolamine, phosphatidyl glycerol, aminolipid and phospholipid. The principal fatty acids in strain MP-1(T) were C18 : 1ω7c/C18 : 1ω6c (23.3 %), C16 : 0 (16.8 %), cyclo-C17 : 0 (15.0 %), C16 : 1ω7c/C16 : 1ω6 (8.5 %), cyclo-C19 : 0ω8c (8.1 %), C16 : 1 iso I/C14 : 0 3-OH (5.7 %), C16 : 0 3-OH (5.6 %) and C16 : 02-OH (5.1 %). The DNA-DNA relatedness values between strain MP-1(T) and the three type strains (B. grimmiae DSM 25160(T), B. zhejiangensis OP-1(T) and B. glathei DSM 50014(T)) ranged from 24.6 % to 37.4 %. In accordance with phenotypic and genotypic characteristics, strain MP-1(T) represents a novel

  2. Biodegradation of methyl parathion and endosulfan using Pseudomonas aeruginosa and Trichoderma viridae.

    PubMed

    Senthilkumar, S; Anthonisamy, A; Arunkumar, S; Sivakumari, V

    2011-01-01

    Microorganisms play an important role in the bioconversion and total breakdown of pesticides in the environment. This study was conducted to assess the pesticide degradation (endosulfan and methyl parathion) ability of the bacteria and fungi (Pseudomonas aeruginosa and Trichoderma viridae). The screening test conducted to reveal the ability to degrade endosulfan and methyl parathion shows that Trichoderma viridae was effective compared to Pseudomonas aeruginosa. The pesticide degradation was estimated by optical density method. Methyl parathion was highly degraded compared to endosulfan. This study clearly proves that pesticides and their residue degradation can be accelerated by employing microbes which can be effectively utilized both as biocontrol agent and soil cleanser.

  3. Depression of plasma luteinizing hormone concentration in quail by the anticholinesterase insecticide parathion

    USGS Publications Warehouse

    Rattner, B.A.; Clarke, R.N.; Ottinger, M.A.

    1986-01-01

    To examine the effects of parathion on basal plasma luteinizing hormone (LH) concentration, male Japanese quail (Coturnix japonica) were orally intubated with 0, 5 or 10 mg/kg parathion and sacrificed after 4, 8 and 24 hr. At the 5 mg/kg dose, plasma LH levels were reduced at 4 and 8 hr, but returned to control values by 24 hr. Brain acetylcholinesterase activity was substantially reduced by 10 mg/kg parathion (52, 75 and 37% inhibition at 4, 8 and 24 hr, respectively) and plasma LH concentration remained depressed through the 24-hr period. These findings suggest that the organophosphorus insecticide parathion may alter plasma LH concentration in a manner which might impair reproductive activity, and provide indirect evidence for a cholinergic component in the regulation of LH secretion in quail.

  4. Spectrofluorimetric study of the interaction of methyl-parathion with fish serum albumin.

    PubMed

    Silva, Dilson; Cortez-Moreira, Madelayne; Bastos, Vera Lúcia Freire Cunha; Bastos, Jayme Cunha; Cortez, Célia Martins

    2010-09-01

    The interaction of methyl-parathion with the albumin of Piaractus mesopotamicus (Holmberg 1887) (= pacu), a fish species typical of Brazilian rivers, was studied and the results compared with known values for human and bovine albumin obtained in an earlier investigation. Methyl-parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) is an organophosphorous pesticide still used in agriculture and fish farming in many countries. The fluorescence quenching technique with tryptophan as a natural probe was used to detect for the presence of methyl-parathion. Fluorescence can be mathematically expressed by the Stern-Volmer equation to calculate quenching constants, and changes in the behavior of Stern-Volmer curves at different temperatures indicate the nature of the mechanism causing the quenching. Our results indicate that methyl-parathion forms a complex with fish albumin. The estimated association constant is 9.73 x 103 (+/- 4.9 x 102) M(-1) at 25 degrees C.

  5. A model for linking the effects of parathion in soil to its degradation and bioavailability kinetics.

    PubMed

    Saffih-Hdadi, K; Bruckler, L; Lafolie, F; Barriuso, E

    2006-01-01

    Parathion is an insecticide of a group of highly toxic organophosphorus compounds. To investigate the dissipation and toxicological impact of parathion [O,O-diethyl O-(4-nitrophenyl) phosphorothioate] and its highly toxic metabolite, paraoxon, soil laboratory experiments were conducted in columns during a 19-d experiment under variably saturated conditions. Water and pesticide transport, sorption, and biodegradation of parathion were measured in three soil pools (soluble phase, weakly and strongly sorbed phases) using C-labeled pesticide. The effects of parathion and its metabolite on the mobility of soil nematodes were observed and then modeled with an effective variable, which combined pesticide concentration and time of application. Results showed that parathion was highly sorbed and slowly degraded to a mixture of metabolites. The parent compound and its metabolites remained located in the top 0.06-m soil layer. A kinetic model describing the sorption, biodegradation, and allocation into different soil pools of parathion and its metabolites was coupled with heat and water transport equations to predict the fate of parathion in soil. Simulated results were in agreement with experimental data, showing that the products remained in the upper soil layers even in the case of long-term (11-mo) simulation. The strongly sorbed fraction may be regarded as a pesticide reservoir that regularly provides pesticide to the weakly sorbed phase, and then, liquid phase, respectively. From both modeling and observations, no major toxicological damage of parathion and paraoxon to soil nematodes was found, although some effects on nematodes were possible, but at the soil surface only (0.01- and 0.02-m depth).

  6. Behavior of parathion in apple juice processed into cider and vinegar.

    PubMed

    Banna, A A; Kawar, N S

    1982-01-01

    Apple juice, fortified with 25 ppm (ug/g) of parathion, was processed into cider and vinegar. After the initial fermentation period of 12 days, the supernatant cider contained 7.4 ppm of parathion while the level in the sedimented lees was 88 ppm. Sorption to the sedimented matter was the main pathway for parathion residue reduction in the cider. Levels of aminoparathion and 4-nitrophenol, the only metabolites of parathion detected as confirmed by thin-layer chromatography, were 0.19 and 1.2 ppm, respectively, in the cider. The 56-day-old finished cider prior to bottling contained 2.2 ppm parathion, 0.15 ppm aminoparathion and 1.3 ppm 4-nitrophenol. Storage of the cider at 24, 12, 4 and -20 degrees C resulted in further reduction in the parathion levels. After one year, samples stored at 24 degrees C contained only 2.5% of the initial level added to the juice. Samples stored at the three other temperatures contained about 5% of the original level. Vinegar formed after 57 days of fermentation contained 5.1 ppm parathion, while the residue level in the lees was 76 ppm. Aminoparathion and 4-nitrophenol levels were 0.23 and 1.2 ppm, respectively in the vinegar. Storage of the vinegar at 24 degrees C for one year resulted in a gradual decline in the parathion level and at the end of the storage period, the remaining residue represented about 6% of the initial 24 ppm added to the juice.

  7. Studies on the metabolism of diethyl 4-nitrophenyl phosphorothionate (parathion) in vitro.

    PubMed

    Neal, R A

    1967-04-01

    1. The metabolism of the phosphorothionate parathion in vitro was examined by using [(32)P]parathion and microsomes isolated from the livers of various animal species. 2. The major metabolic products of parathion in this system in vitro were identified as diethyl 4-nitrophenyl phosphate (paraoxon), diethyl hydrogen phosphate, diethyl hydrogen phosphorothionate and p-nitrophenol. 3. The reaction leading to the formation of diethyl hydrogen phosphorothionate and p-nitrophenol requires the same cofactors (NADPH and oxygen) required for metabolism of parathion to its active anti-acetylcholinesterase paraoxon. 4. The enzyme activity towards parathion per unit weight of liver is increased some 65-130% by pretreatment of male rats with phenobarbital and 3,4-benzopyrene. 5. The metabolism of parathion is inhibited by incubation in a nitrogen atmosphere and in an atmosphere containing carbon monoxide. Pure oxygen is also inhibitory. These results are discussed in terms of a deficiency of oxygen for maximal activity as well as the lability of some component of the system to oxidation.

  8. Graphene modified screen printed immunosensor for highly sensitive detection of parathion.

    PubMed

    Mehta, Jyotsana; Vinayak, Priya; Tuteja, Satish K; Chhabra, Varun A; Bhardwaj, Neha; Paul, A K; Kim, Ki-Hyun; Deep, Akash

    2016-09-15

    Due to indiscriminate use of pesticides, there is a growing need to develop sensors that can sensitively detect the trace amount of pesticides in food and water samples. Parathion, identified as an acetylcholinesterase inhibitor, had been one of the most widely used pesticides throughout the world. Symptoms of its poisoning are found to be diverse enough to include nausea, vomiting, diarrhea, muscle cramping/twitching, and shortness of breath. In this work, a graphene based impedimetric immunosensor has been fabricated and employed for highly sensitive and specific detection of parathion. The fabrication proceeded through the modification of the screen-printed carbon electrodes (SPE) with graphene sheets, followed by their functionalization with 2-aminobenzyl amine (2-ABA) via an electrochemical reaction. These amine functionalized graphene electrodes were then bio-interfaced with the anti-parathion antibodies. In the impedimetric mode, this biosensor detected parathion in a broad linear range, i.e. 0.1-1000ng/L with a very low limit of detection (52pg/L). It also showed high selectivity towards parathion in the presence of malathion, paraoxon, and fenitrothion. The viability of this biosensor was demonstrated by detecting parathion in real samples (e.g., tomato and carrot) and through cross-calibration against HPLC.

  9. Reduced glutathione attenuates liver injury induced by methyl parathion in rats.

    PubMed

    Jiang, Na; Lu, Lina; Wang, Tian; Zhang, Leiming; Xin, Wenyu; Fu, Fenghua

    2010-02-01

    The aim of this study was to investigate whether exogenous reduced glutathione (GSH) could protect liver injury induced by methyl parathion. Rats were allocated into four groups named as control, MP (methyl parathion poisoning), MP+GSH1 (methyl parathion poisoning treated with GSH 600 mg/kg), and MP+GSH2 (methyl parathion poisoning treated with GSH 1200 mg/kg). Each one of the last three groups was assigned into 6 h, 24 h, and 72 h sub-groups. The activities of acetylcholinesterase (AChE), glutamate pyruvate transaminase (GPT), and glutamic oxalacetic transaminase (GOT) in plasma, and superoxide dismutase (SOD) and glutathione peroxidase (GPx) in liver were assayed. The malondialdehyde (MDA) in liver was also determined. Histopathological changes in liver were observed. Results showed that AChE activity was significantly inhibited by methyl parathion and attenuated after GSH administered. GSH could relieve hepatocellular edema and fatty degeneration, and attenuate the increased activities of GPT and GOT. GSH treatment increased the SOD and GPx activities, but had no effect on the MDA level. These results indicated that GSH could attenuate liver injury induced by methyl parathion.

  10. Simultaneous detection of imidacloprid and parathion by the dual-labeled time-resolved fluoroimmunoassay.

    PubMed

    Shi, Haiyan; Sheng, Enze; Feng, Lu; Zhou, Liangliang; Hua, Xiude; Wang, Minghua

    2015-10-01

    A highly sensitive direct dual-labeled time-resolved fluoroimmunoassay (TRFIA) to detect parathion and imidacloprid simultaneously in food and environmental matrices was developed. Europium (Eu(3+)) and samarium (Sm(3+)) were used as fluorescent labels by coupling separately with L1-Ab and A1P1-Ab. Under optimal assay conditions, the half-maximal inhibition concentration (IC50) and limit of detection (LOD, IC10) were 10.87 and 0.025 μg/L for parathion and 7.08 and 0.028 μg/L for imidacloprid, respectively. The cross-reactivities (CR) were negligible except for methyl-parathion (42.4 %) and imidaclothiz (103.4 %). The average recoveries of imidacloprid ranged from 78.9 to 104.2 % in water, soil, rice, tomato, and Chinese cabbage with a relative standard deviation (RSD) of 2.4 to 11.6 %, and those of parathion were from 81.5 to 110.9 % with the RSD of 3.2 to 10.5 %. The results of TRFIA for the authentic samples were validated by comparison with gas chromatography (GC) analyses, and satisfactory correlations (parathion: R (2) = 0.9918; imidacloprid: R (2) = 0.9908) were obtained. The results indicate that the dual-labeled TRFIA is convenient and reliable to detect parathion and imidacloprid simultaneously in food and environmental matrices.

  11. Kinetics and mechanism of the degradation of methyl parathion in aqueous hydrogen sulfide solution: investigation of natural organic matter effects.

    PubMed

    Guo, Xiaofen; Jans, Urs

    2006-02-01

    The kinetics of the transformation of methyl parathion have been investigated in aqueous solution containing reduced sulfur species and small concentrations of natural organic matter (NOM) from different sources such as soil, river, and peat. It was shown that NOM mediates the degradation of methyl parathion in aqueous solutions containing hydrogen sulfide. After evaluating and quantifying the effect of the NOM concentration on the degradation kinetics of methyl parathion in the presence of hydrogen sulfide, it was found that the observed pseudo-first-order reaction rate constants (k(obs)) were proportional to NOM concentrations. The influence of pH on the degradation of methyl parathion in the aqueous solutions containing hydrogen sulfide and NOM has been studied. The rate of degradation of methyl parathion was strongly pH dependent. The results indicate k(obs) with a commercially available humic acid has a maximum value at approximately pH 8.3. Two main reaction mechanisms are identified to dominate the degradation of methyl parathion in aqueous solution containing hydrogen sulfide and NOM based on the products aminomethyl parathion and desmethyl methyl parathion. The two mechanisms are nitro-group reduction and nucleophilic attack at the methoxy-carbon. The reduction of the nitro-group is only observed in the presence of NOM. The results of this study form an important base for the evaluation and interpretation of transformation processes of methyl parathion in the environment.

  12. Enhancement of parathion toxicity to quail by heat and cold exposure

    USGS Publications Warehouse

    Rattner, B.A.; Becker, J.M.; Nakatsugawa, T.

    1987-01-01

    Effects of ambient temperature on the acute oral toxicity of parathion were investigated in Japanese quail (Coturnix japonica) maintained at thermoneutral temperature (26.degree. C) or exposed to elevated (37.degree. C) or reduced (4.degree. C) temperatures commonly encountered by free-ranging wild birds. Based upon estimates of the median lethal dosage, there was up to a two-fold enhancement of parathion toxicity in birds chronically exposed to heat or cold. Twenty-four hours after administration of a low dosage (4 mg/kg body wt, po), there was markedly greater cholinesterase inhibition in surviving heat-exposed quail compared with those reared at 26.degree. C (e.g., brain acetylcholinesterase depression of 42% versus 12%). There were no differences in hepatic activities of parathion oxidase, paraoxonase, or paraoxon deethylase which could account for greater toxicity to chronically heat-exposed birds. In contrast, 4 mg parathion/kg wt elicited less plasma cholinesterase inhibition in cold-exposed quail compared to thermoneutral controls (e.g., < 10% versus 48% depression after 24 hr). Increased liver weight and a doubling of paraoxonase activity may have been associated with greater tolerance to sublethal doses of parathion in chronically cold-exposed quail. These findings, together with limited field observations, indicate that the hazard associated with anticholinesterase exposure of wild birds is substantially influenced by environmental temperature.

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

    PubMed Central

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

    2015-01-01

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

  14. Effects on wildlife of ethyl and methyl parathion applied to California rice fields

    USGS Publications Warehouse

    Custer, T.W.; Hill, E.F.; Ohlendorf, H.M.

    1985-01-01

    Selected rice fields on the Sacramento National Wildlife Refuge Complex were aerially sprayed one time during May or June 1982 with either ethyl (0.11 kg Al/ha) or methyl (0.84 kg AI/ha) parathion for control of tadpole shrimp, Triops longicaudatus. No sick or dead vertebrate wildlife were found or adjacent to the treated rice fields after spraying. Specimens of the following birds and mammals were assayed for brain cholinesterase (ChE) activity to determine exposure to either form of parathion; house mouse, Mus musculus; black-tailed jackrabbit, Lepus californicus; mallard, Anas platyrhynchos; ring-necked pheasant, Phasianus colchicus; American coot, Fulica americana; and red-winged blackbird, Agelaius phoeniceus. Both mice and pheasants from methyl parathion-treated fields had overall mean ChE activities that were significantly (P < 0.05) inhibited compared with controls, and 7, 40, 54 and 57% of individual blackbirds, pheasant, mice, and coots, respectively, had inhibited brain ChE activities (i.e., less than -2 SD of control mean). Although no overall species effect was detected for ethyl parathoid treatment, pheasants (43%), coots (33%), and mice (37%) had significantly inhibited brain ChE activities. Neither of the parathion treatment appeared acutely hazardous to wildlife in or adjacent to rice fields, but sufficient information on potential hazards was obtained to warrant caution in use of these chemicals, especially methyl parathion, in rice fields.

  15. Effects of wildlife of ethyl and methyl parathion applied to California USA rice fields

    USGS Publications Warehouse

    Custer, T.W.; Hill, E.F.; Ohlendorf, H.M.

    1985-01-01

    Selected rice fields on the Sacramento National Wildlife Refuge Complex were aerially sprayed one time during May or June 1982 with either ethyl (0.11 kg Al/ha) or methyl (0.84 kg AI/ha) parathion for control of tadpole shrimp, Triops longicaudatus. No sick or dead vertebrate wildlife were found or adjacent to the treated rice fields after spraying. Specimens of the following birds and mammals were assayed for brain cholinesterase (ChE) activity to determine exposure to either form of parathion; house mouse, Mus musculus; black-tailed jackrabbit, Lepus californicus; mallard, Anas platyrhynchos; ring-necked pheasant, Phasianus colchicus; American coot, Fulica americana; and red-winged blackbird, Agelaius phoeniceus. Both mice and pheasants from methyl parathion-treated fields had overall mean ChE activities that were significantly (P < 0.05) inhibited compared with controls, and 7, 40, 54 and 57% of individual blackbirds, pheasant, mice, and coots, respectively, had inhibited brain ChE activities (i.e., less than -2 SD of control mean). Although no overall species effect was detected for ethyl parathoid treatment, pheasants (43%), coots (33%), and mice (37%) had significantly inhibited brain ChE activities. Neither of the parathion treatment appeared acutely hazardous to wildlife in or adjacent to rice fields, but sufficient information on potential hazards was obtained to warrant caution in use of these chemicals, especially methyl parathion, in rice fields.

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

    PubMed

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

    2015-01-01

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

  17. Effect of methyl parathion on nitrous oxide production: a laboratory study.

    PubMed

    Rojas-Oropeza, Marcelo; Fernández, Francisco J; Dendooven, Luc; Cabirol, Nathalie

    2012-03-01

    We investigated the diversity of a denitrifying gene (nirK) and the emission of CO(2) and N(2)O, in a "chinampa" soil contaminated with methyl parathion. Soil at 40% of water holding capacity was spiked with methyl parathion at four concentrations (i.e. 0, 0.7, 1.47 and 4.27 g kg(-1) dry soil), while emission of N(2)O and CO(2) and nirK diversity was determined after 0, 1, 14, 30, 60 and 90 days. The emission of N(2)O on a daily base and the cumulative emission of CO(2) was not affected by the different concentrations of methyl parathion applied to soil. The diversity of the nirK gene, determined by using temperature gradient gel electrophoresis (TGGE), decreased with increased methyl parathion application. It was found that methyl parathion had effect on the emissions of N(2)O and CO(2), and reduced the diversity of the nirK gene. Consequently, the reduced diversity of the nirK gene could affect the emission of N(2)O.

  18. A molecularly imprinted polymer based on functionalized multiwalled carbon nanotubes for the electrochemical detection of parathion-methyl.

    PubMed

    Zhang, Dan; Yu, Dajun; Zhao, Wenjie; Yang, Qinyan; Kajiura, Hisashi; Li, Yongming; Zhou, Tianshu; Shi, Guoyue

    2012-06-07

    A novel composite of vinyl group functionalized multiwalled carbon nanotubes (MWCNTs) molecularly imprinted polymer (MIP) was synthesized and applied as a molecular recognition element to construct an electrochemical sensor for parathion-methyl in this paper. The special molecular recognition properties of parathion-methyl mainly dominated by π-π, p-π interaction and hydrogen bonding formed among functional monomer, template and matrix. A series of electrochemical experiment results proved that the prepared material had good adsorption capacity and fast mass transfer rate to parathion-methyl. The good selectivity of the sensor allowed fine discrimination between parathion and paraoxon, which had similar structures to parathion-methyl. The response of the MIPs was linearly proportional to the concentration of parathion-methyl over the range of 2.0 × 10(-7) to 1.0 × 10(-5) mol L(-1) with a lower detection limit of 6.7 × 10(-8) mol L(-1) (S/N = 3). This sensor was also applied in the detection of parathion-methyl in pear and cucumber with average recoveries of between 94.9% and 106.2% (RSD < 5%) being obtained. The results mentioned above show that the novel electrochemical sensor is an ideal device for the real-time determination of parathion-methyl in real samples.

  19. Absence of circannual toxicity of parathion to starlings

    USGS Publications Warehouse

    Rattner, B.A.; Grue, C.E.

    1990-01-01

    Ambient temperature and season have been observed to influence the toxicity of several environmental pollutants in homeotherms. The circannual toxicity of ethyl parathion (EP) was examined in adult European starlings (Sturnus vulgaris). Groups of birds housed in outdoor pens received oral doses of EP (20-150 mg/kg body weight) in fall, winter, spring and summer (temperature range -3.3 to 36.7?C). The median lethal dosage (LD50), and brain and plasma cholinesterase inhibition, were found to be quite similar among seasons. There was some suggestion that EP may have been more toxic during hot weather (winter versus summer LD50 estimate [95% confidence interval]:160 [114-225] vs. 118 [102-136] mg/kg; P<0.10). In view of previous reports in which ambient temperature extremes and harsh weather have enhanced organophosphorus insecticide toxicity to birds, it is concluded that circannual toxicity studies should include measures of sensitivity (acute oral exposure) and vulnerability (dietary exposure) to better predict responses of free-ranging birds

  20. Methyl parathion in residential properties: relocation and decontamination methodology.

    PubMed Central

    Clark, J Milton; Bing-Canar, John; Renninger, Steve; Dollhopf, Ralph; El-Zein, Jason; Star, Dave; Zimmerman, Dea; Anisuzzaman, Abul; Boylan, Kathline; Tomaszewski, Terrence; Pearce, Ken; Yacovac, Rebecca; Erlwein, Bobby; Ward, John

    2002-01-01

    In November 1994 methyl parathion (MP), a restricted agricultural pesticide, was discovered to have been illegally sprayed within hundreds of residences in Lorain County, Ohio. Surface levels and air concentrations of MP revealed detectable levels of the pesticide 3 years after spraying. Because of the high toxicity of MP (lethal dose to 50% of rats tested [LD50] = 15 mg/kg) and long half-life indoors, risk-based relocation and decontamination criteria were created. Relocation criteria were derived based on levels of p-nitrophenol in urine, a metabolic byproduct of MP exposure. In Ohio, concentrations of MP on surfaces and in the air were also used to trigger relocations. The criteria applied in Ohio underwent refinement as cases of MP misuse were found in Mississippi and then in several other states. The MP investigation (1994-1997) was the largest pesticide misuse case in the nation, ultimately involving the sampling of 9,000 residences and the decontamination of 1,000 properties. This article describes the methodology used for relocation of residents and decontamination of properties having MP. PMID:12634141

  1. Analytical and toxicological studies of decomposition of insecticide parathion after gamma-irradiation and ozonation.

    PubMed

    Bojanowska-Czajka, Anna; Torun, Murat; Kciuk, Gabriel; Wachowicz, Mariusz; Ozbay, Dilek Solpan; Guven, Olgun; Bobrowski, Krzysztof; Trojanowicz, Marek

    2012-01-01

    The decomposition of the widely used organophosphorus pesticide parathion was carried out in aqueous solutions by the use of gamma-irradiation from a 60Co source or ozonation by means of an ozone generator, and by combined processes of ozonation and radiolysis. Factors affecting the parathion decomposition as well formation and decomposition of the main by-products, including irradiation dose, length of ozonation time, and presence of common scavengers, were investigated. The most efficient was found to be the gamma-irradiation process combined with a short ozonation period; about 1 kGy irradiation dose was sufficient to decompose the pesticide in 15 mg/L solutions. Chemical studies of the decomposition of parathion were accompanied by monitoring of toxicity changes of irradiated solutions with the Microtox test.

  2. Toxicity of parathion to captive European starlings (Sturnus vulgaris)-absence of seasonal effects

    USGS Publications Warehouse

    Rattner, B.A.; Grue, C.E.

    1990-01-01

    The effects of season on the toxicity of the prototypic organophosphorus insecticide parathion was evaluated using adult European starlings (Sturnus vulgaris) housed in outdoor pens. Groups of birds received oral doses of parathion in the fall, winter, spring and summer. Median lethal dosage, and brain and plasma cholinesterase inhibition, were found to be quite similar among seasons. Parathion may have been more toxic during hot weather (winter vs. summer LD50 estimate: 160 vs. 118 mg/kg; p < 0.1). In view of previous reports in which ambient temperature extremes and harsh weather have enhanced organophosphorus insecticide toxicity to birds, it is concluded that circannual toxicity studies should include measures of sensitivity (acute oral exposure) and vulnerability (dietary exposure) to better predict responses of free-ranging birds.

  3. Parathion accumulation in cricket frogs and its effect on American kestrels

    USGS Publications Warehouse

    Fleming, W.J.; de Chacin, H.; Pattee, O.H.; Lamont, T.G.

    1982-01-01

    Adult cricket frogs (Acris crepitans) were held individually for 96 h in static systems containing initial concentrations of either 0, 0.1, 1.0, or 10 ppm parathion in 10 ml water. Mortality of cricket frogs was directly related to the parathion concentration in the water. Frogs from the 1.0- and 10-ppm groups accumulated 0.08 and 4.6 ppm parathion, respectively. One of four American kestrels (Falco sparverius) fed frogs from the 10-ppm group died from organophosphate poisoning less than 3 h after consuming five frogs. Mortality did not occur in kestrels fed frogs from the other treatment groups, which represented more environmentally realistic levels of exposure.

  4. Toxicity of cadmium, lead, mercury and methyl parathion on Euchlanis dilatata Ehrenberg 1832 (Rotifera: Monogononta).

    PubMed

    Arias-Almeida, Juan Carlos; Rico-Martínez, Roberto

    2011-08-01

    Acute toxicity tests with Cd, Pb, Hg, and methyl parathion were developed to compare the sensitivity of the rotifer Euchlanis dilatata with other model organisms used in aquatic ecotoxicology. Cd was the most toxic chemical (LC50 = 14.8 μg L(-1)), while methyl parathion was the least toxic (LC50 = 864.2 μg L(-1)). E. dilatata was more sensitive that other rotifer species, particularly of the genera Brachionus and Lecane. However, E. dilatata was less sensitive to mercury and methyl parathion than the crustacean, Daphnia magna. The high sensitivity of E. dilatata suggests that it may be an adequate benthic model to use in toxicity assessments of metal-contaminated sediments.

  5. Probing the simulant behavior of PNPDPP toward parathion and paraoxon: a computational study.

    PubMed

    Khan, Abdul Shafeeuulla; Bandyopadhyay, Tusar; Ganguly, Bishwajit

    2012-04-01

    The extreme toxicity of organophosphorus nerve agents and pesticides mandates to employ models or simulants in place of the actual compounds in the laboratory. The importance of simulants is known, however, their efficacy for direct comparison with the toxic organophosphorus compounds is not well documented. We have examined the potential energy surfaces (PES) for the alkaline hydrolysis of pesticides like paraoxon (diethyl 4-nitrophenyl phosphate), parathion (O,O-diethyl O-4-nitrophenyl phosphorothioate) and PNPDPP (4-nitrophenyl diphenyl phosphate), a simulant with MP2/6-311+G*//B3LYP/6-311+G*+ΔG(solv) (HF/6-31+G*) level of theory. The effect of aqueous solvation was considered with the Integral Equation Formalism Polarizable Continuum Model (IEF-PCM). The alkaline hydrolysis of these organophosphorus compounds reveals that the reaction proceeds through the attack of hydroxide ion at the phosphorus center to form a pentacoordinate intermediate. The calculated free energies of activation for the alkaline hydrolysis of paraoxon and parathion are in good agreement with the available experimental activation free energies. The computed results show that the reaction profiles for the alkaline hydrolysis of paraoxon, parathion and PNPDPP are largely similar; however, the rate of hydrolysis of parathion may be higher than that of paraxon and PNPDPP. Such difference arises due to the less electrophilic nature of the phosphorus atom of parathion molecule as observed in the charge analysis study. The conceptual DFT analysis also showed the similar trend for the alkaline hydrolysis of paraoxon, parathion and PNPDPP with hydroxide anion. This computational study provides a quantitative support toward the use of PNPDPP as a simulant for organophosphorus compounds, which cannot be used directly for the laboratory purposes.

  6. Urinary paranitrophenol, a metabolite of methyl parathion, in Thai farmer and child populations.

    PubMed

    Panuwet, Parinya; Prapamontol, Tippawan; Chantara, Somporn; Thavornyuthikarn, Prasak; Bravo, Roberto; Restrepo, Paula; Walker, Robert D; Williams, Bryan L; Needham, Larry L; Barr, Dana B

    2009-10-01

    Human exposure to methyl parathion can be assessed by measuring the concentration of its metabolite paranitrophenol (PNP) in urine. Our biologic monitoring study in Chiang Mai, Thailand, measured PNP and dialkylphosphate metabolites (i.e., dimethylphosphate [DMP] and dimethylthiophosphate [DMTP]) of methyl parathion in urine samples collected from 136 farmers (age 20 to 65 years) and 306 school children (age 10 to 15 years) in 2006. Participants came from two topographically different areas: one was colder and mountainous, whereas the other was alluvial with climate fluctuations depending on the monsoon season. Both children and farmers were recruited from each area. Despite methyl parathion's prohibited use in agriculture in 2004, we detected PNP in >90% of all samples analyzed. We applied a nonparametric correlation test (PNP vs. DMP and DMTP) to determine whether the PNP found in most of the samples tested resulted from exposures to methyl parathion. DMP (Spearman's rho = 0.601 [p = 0.001] for farmers and Spearman's rho = 0.263 [p <0.001] for children) and DMTP (Spearman's rho = 0.296 [p = 0.003] for farmers and Spearman's rho = 0.304 [p<0.001] for children) were positively correlated with PNP, suggesting a common source for the three analytes, presumably methyl parathion or related environmental degradates. Although we found a modest correlation between the metabolites, our findings suggest that despite the prohibition, at least a portion (approximately 25% to 60%) of the PNP detected among farmers and children in Thailand may be attributed to exposure from continued methyl parathion use.

  7. Removal of chlorothalonil, methyl parathion and methamidophos from water by the Fenton reaction.

    PubMed

    Gutiérrez, R F; Santiesteban, A; Cruz-López, L; Bello-Mendoza, R

    2007-03-01

    The efficiency of a dark Fenton system (H2O2/Fe2+) to remove chlorothalonil from water, alone and in the presence of the organophosphorous pesticides methyl parathion and methamidophos, was evaluated. Here we show that the process is rapid and efficient. Nearly complete degradation of chlorothalonil and methyl parathion (98%) was observed in less than 10 min whereas methamidophos showed similar levels of efficiency only after 40 to 90 min. Formulating agents did not appear to impair the degradation of active ingredients. Interactions during the degradation of mixtures of the three pesticides only appeared to affect methamidophos degradation.

  8. Electrochemical fabrication of molecularly imprinted porous silicate film electrode for fast and selective response of methyl parathion.

    PubMed

    Tan, Xiaohong; Li, Buhai; Liew, Kongyong; Li, Chunya

    2010-10-15

    A methyl parathion-templated molecularly imprinted porous silicate thin film was electrodeposited onto a glassy carbon electrode using tetraethylorthosilicate sol as the silicon precursor and vinyltriethoxysilane as the functional monomer. The surface morphology and crystallinity of the imprinted film were characterized by scanning electron microscope and X-ray diffraction. The binding performance of the film with methyl parathion was examined with voltammetric techniques. The results show that the imprinted sol-gel film gives fast, sensitive and selective response to methyl parathion. The good selectivity of the film allows fine discriminations of methyl parathion from interferants, which including parathion, α-hydroxyl-4-nitrophenyl-dimethyl-phosphonate, p-nitrophenol and nitrobenzene. A linear range for methyl parathion determination was found from 1.0×10(-8) to 1.0×10(-5) mol l(-1) with an estimated detection limit of 8.9×10(-9) mol l(-1) (S/N=3). This imprinted sol-gel film electrode was proved to be a versatile sensing tool for the selective detection of methyl parathion in real samples.

  9. Purification and characterization of three parathion hydrolases from gram-negative bacterial strains.

    PubMed

    Mulbry, W W; Karns, J S

    1989-02-01

    Three unique parathion hydrolases were purified from gram-negative bacterial isolates and characterized. All three purified enzymes had roughly comparable affinities for ethyl parathion and had broad temperature optima at ca. 40 degrees C. The membrane-bound hydrolase of Flavobacterium sp. strain ATCC 27551 was composed of a single subunit of approximately 35,000 daltons (Da) and was inhibited by sulfhydryl reagents such as dithiothreitol (DTT) and by metal salts such as CuCl2. The cytosolic hydrolase of strain B-1 was composed of a single subunit of approximately 43,000 Da and was stimulated by DTT and inhibited by CuCl2. The membrane-bound hydrolase of strain SC was composed of four identical subunits of 67,000 Da and was inhibited by DTT and stimulated by CuCl2. The substrate ranges of the three enzymes also differed, as evidenced by their relative affinities for parathion and the related organophosphate insecticide O-ethyl-O-4-nitrophenyl phenylphosphonothioate (EPN). The B-1 hydrolase displayed equal affinity for both compounds, the Flavobacterium enzyme showed twofold-lower affinity for EPN than for parathion, and the SC hydrolase displayed no activity toward EPN. The range in characteristics of these three enzymes can be exploited in different waste disposal strategies.

  10. Purification and characterization of three parathion hydrolases from gram-negative bacterial strains.

    PubMed Central

    Mulbry, W W; Karns, J S

    1989-01-01

    Three unique parathion hydrolases were purified from gram-negative bacterial isolates and characterized. All three purified enzymes had roughly comparable affinities for ethyl parathion and had broad temperature optima at ca. 40 degrees C. The membrane-bound hydrolase of Flavobacterium sp. strain ATCC 27551 was composed of a single subunit of approximately 35,000 daltons (Da) and was inhibited by sulfhydryl reagents such as dithiothreitol (DTT) and by metal salts such as CuCl2. The cytosolic hydrolase of strain B-1 was composed of a single subunit of approximately 43,000 Da and was stimulated by DTT and inhibited by CuCl2. The membrane-bound hydrolase of strain SC was composed of four identical subunits of 67,000 Da and was inhibited by DTT and stimulated by CuCl2. The substrate ranges of the three enzymes also differed, as evidenced by their relative affinities for parathion and the related organophosphate insecticide O-ethyl-O-4-nitrophenyl phenylphosphonothioate (EPN). The B-1 hydrolase displayed equal affinity for both compounds, the Flavobacterium enzyme showed twofold-lower affinity for EPN than for parathion, and the SC hydrolase displayed no activity toward EPN. The range in characteristics of these three enzymes can be exploited in different waste disposal strategies. Images PMID:2541658

  11. Metal organic frameworks (MOFs) for degradation of nerve agent simulant parathion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parathion, a simulant of nerve agent VX, has been studied for degradation on Fe3+, Fe2+ and zerovalent iron supported on chitosan. Chitosan, a naturally occurring biopolymer derivative of chitin, is a very good adsorbent for many chemicals including metals. Chitosan is used as supporting biopolymer ...

  12. Metal organic frameworks (MOFs) for degrdation of nerve agent simulant parathion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parathion, a simulant of nerve agent VX, has been studied for degradation on Fe3+, Fe2+ and zerovalent iron supported on chitosan. Chitosan, a naturally occurring biopolymer derivative of chitin, is a very good adsorbent for many chemicals including metals. Chitosan is used as supporting biopolymer ...

  13. Microbial biosensor for detection of methyl parathion using screen printed carbon electrode and cyclic voltammetry.

    PubMed

    Kumar, Jitendra; D'Souza, S F

    2011-07-15

    Whole cells of recombinant Escherichia coli were immobilized on the screen printed carbon electrode (SPCE) using glutaraldehyde. Recombinant E. coli was having high periplasmic expression of organophosphorus hydrolase enzyme, which hydrolyzes the methyl parathion into two products, p-nitrophenol and dimethyl thiophosphoric acid. Cells immobilized SPCE was studied under SEM. Cells immobilized SPCE was associated with cyclic voltammetry and cyclic voltammograms were recorded before and after hydrolysis of methyl parathion. Detection was calibrated based on the relationship between the changes in the current observed at +0.1 V potential, because of redox behavior of the hydrolyzed product p-nitrophenol. As concentration of methyl parathion was increased the oxidation current also increased. Only 20 μl volume of the sample was required for analysis. Detection range of biosensor was calibrated between 2 and 80 μM of methyl parathion from the linear range of calibration plot. A single immobilized SPCE was reused for 32 reactions with retention of 80% of its initial enzyme activity.

  14. Electrochemical investigation of methyl parathion at gold-sodium dodecylbenzene sulfonate nanoparticles modified glassy carbon electrode.

    PubMed

    Li, Chunya; Wang, Zhengguo; Zhan, Guoqin

    2011-01-01

    A gold/sodium dodecylbenzene sulfonate nanoparticles modified glassy carbon electrode (nano-Au/SDBS/GCE) was electrochemically fabricated with a constant potential at -0.4V. The obtained nano-Au/SDBS/GCE was characterized with scanning electronic microscopy, X-ray photoelectron spectroscopy and electrochemical techniques. Electrochemical behaviors of methyl parathion at the nano-Au/SDBS/GCE were thoroughly investigated. Compared to the unmodified electrode, the peak current obviously increased and the oxidation peak potential negatively shifted. These changes indicated that the composite nanoparticles possess good electrocatalytic performance on the electrochemical reaction of methyl parathion. Experimental parameters such as deposition time, pH value and accumulation conditions were optimized. Under optimum conditions, the peak current corresponding to the oxidation of the hydroxylamine group was found in a good linear relationship with the methyl parathion concentration. In addition, a calibration curve with excellent linearity was obtained in the concentration range from 5.0×10(-7)molL(-1) to 1.0×10(-4)molL(-1) with an estimated detection limit of 8.6×10(-8)molL(-1) (S/N=3). The successful determination of methyl parathion in real samples demonstrated the usefulness and potential applications of this method.

  15. Removal of methyl parathion by cyanobacteria Microcystis novacekii under culture conditions.

    PubMed

    Fioravante, Isabela Araújo; Barbosa, Francisco Antônio Rodrigues; Augusti, Rodinei; Magalhães, Sérgia Maria Starling

    2010-06-01

    This study investigated the removal of methyl parathion by cyanobacteria Microcystis novacekii in culture conditions and evaluated toxicity in terms of EC(50) of the pesticide for the species. This is the first report on the removal and toxicity of methyl parathion for the species that is abundant and easily accessible in Brazilian lakes. The results have shown that Microcystis novacekii is capable of removing methyl parathion, an organophosphorus pesticide, from the culture medium with an extraction rate higher than 90%. Spontaneous degradation was not significant, which indicates a high efficiency level of biological removal. No metabolites of methyl parathion were detected in the culture medium at the concentration levels evaluated (0.10 to 2.00 mg/dm(3)). The mechanisms proposed to explain pesticide removal are bioaccumulation and mineralization. EC(50) for 72 h was 17.60 mg/dm(3), which is much higher than the usual concentrations in surface waters. This indicates that M. novacekii is highly tolerant of this pesticide and may represent an important bioremediation agent of contaminated environments.

  16. Effects of malathion, diazinon, and parathion on mallard embryo development and cholinesterase activity

    USGS Publications Warehouse

    Hoffman, D.J.; Eastin, W.C.

    1981-01-01

    The effects of external exposure of mallard (Anas platyrhynchos) eggs to malathion, diazinon, and parathion were examined using formulations and concentrations similar to field applications. Treatment with aqueous emulsion simulated exposure at the rate of 100 gal per acre (153 liters/hectare) with three to six different doses per compound with treatment at 3 and 8 days of embryonic development. Treatment with a nontoxic oil vehicle simulated exposure at the rate of 11 gal per acre (16.8 liters/hectare) with three to six different doses per compound. The order of embryotoxicity on a pounds-per-acre basis was parathion > diazinon > malathion with either vehicle. However, the potential hazard under conditions of up to five times the maximum field level of application was greater for malathion because of the high permissible level of application for malathion on certain crops. Parathion, the most embryotoxic of the three, had the most pronounced effects when an oil vehicle was used, as reflected by an LC50 of about 2 lb of active ingredient per acre, stunted growth, and a high frequency of malformations involving distortion of the axial skeleton, particularly in the cervical region. All three compounds resulted in significant depression of plasma and brain cholinesterase activity, but parathion caused the most depression throughout development, which was still apparent in hatchlings. Treatment with either distilled water or oil vehicle alone did not result in any of these effects seen with organophosphorous insecticides.

  17. 75 FR 78243 - Propionic Acid and Salts, Urea Sulfate, Methidathion, and Methyl Parathion; Registration Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-15

    ... AGENCY Propionic Acid and Salts, Urea Sulfate, Methidathion, and Methyl Parathion; Registration Review... pesticides propionic acid and salts, case no. 4078, urea sulfate, case no. 7213, methidathion, case no. 0034... pesticides in the table below--propionic acid and salts, case 4078, urea sulfate, case no. 7213,...

  18. Children's exposure to chlorpyrifos and parathion in an agricultural community in central Washington State.

    PubMed Central

    Fenske, Richard A; Lu, Chensheng; Barr, Dana; Needham, Larry

    2002-01-01

    We measured two diethyl organophosphorus (OP) pesticides--chlorpyrifos and parathion--in residences, and their metabolic by-products, in the urine of children 6 years old or younger in a central Washington State agricultural community. Exposures to two dimethyl OP pesticides (azinphos-methyl and phosmet) in this same population have been reported previously. We categorized children by parental occupation and by household proximity to pesticide-treated farmland. Median chlorpyrifos house dust concentrations were highest for the 49 applicator homes (0.4 microg/g), followed by the 12 farm-worker homes (0.3 microg/g) and the 14 nonagricultural reference homes (0.1 microg/g), and were statistically different (p < 0.001); we observed a similar pattern for parathion in house dust. Chlorpyrifos was measurable in the house dust of all homes, whereas we found parathion in only 41% of the homes. Twenty-four percent of the urine samples from study children had measurable 3,5,6-trichloro-2-pyridinol (TCPy) concentrations [limits of quantitation (LOQ) = 8 microg/L], and 7% had measurable 4-nitrophenol concentrations (LOQ = 9 microg/L). Child urinary metabolite concentrations did not differ across parental occupational classifications. Homes in close proximity (200 ft/60 m) to pesticide-treated farmland had higher chlorpyrifos (p = 0.01) and parathion (p = 0.014) house dust concentrations than did homes farther away, but this effect was not reflected in the urinary metabolite data. Use of OP pesticides in the garden was associated with an increase in TCPy concentrations in children's urine. Parathion concentrations in house dust decreased 10-fold from 1992 to 1995, consistent with the discontinued use of this product in the region in the early 1990s. PMID:12003762

  19. Mass spectrometric detection of CYP450 adducts following oxidative desulfuration of methyl parathion.

    PubMed

    Kyle, Patrick B; Smith, Stanley V; Baker, Rodney C; Kramer, Robert E

    2013-07-01

    Cytochrome P450 (CYP)-mediated desulfuration of methyl parathion results in mechanism-based inhibition of the enzyme. Although previous data suggest that reactive sulfur is released and binds to the apoprotein, the identities of neither the adduct(s) nor the affected amino acid(s) have been clearly determined. In this study, nanospray tandem mass spectroscopy was used to analyze peptide digests of CYP resolved by SDS-PAGE from liver microsomes of male rats following incubation in the absence or presence of methyl parathion. Oxidative desulfuration was confirmed by measurement of methyl paraoxon, and inhibition of specific CYP isozymes was determined by measurement of testosterone hydroxylation. Total CYP content was quantified spectrophotometrically. Incubation of microsomes with methyl parathion decreased CYP content by 58%. This effect was not associated with a comparable increase in absorbance at 420 nm, suggesting the displacement of heme from the apoprotein. Rates of testosterone 2β- and 6β-hydroxylation, respectively, were reduced to 8 and 2%, implicating CYP3A and CYP2C11 in the oxidative desulfuration of methyl parathion. Mass spectrometric analysis identified 96 amu adducts to cysteines 64 and 378 of CYP3A1. In addition, a peptide containing cysteine 433 that coordinates with heme was possibly modified as it was detected in control, but not methyl parathion samples. A comparison of rat CYP3A1 with human CYP3A4 suggests that cysteines 64 and 378 reside along the substrate channel, remote from the active site. Alteration of these residues might modulate substrate entry to the binding pocket of the enzyme.

  20. Oviposition and the plasma concentrations of LH, progesterone, and corticosterone in bobwhite quail (Colinus virginianus) fed parathion

    USGS Publications Warehouse

    Rattner, B.A.; Sileo, L.; Scanes, C.G.

    1982-01-01

    Bobwhite quail were fed concentrations of parathion (0,50, 100, 200 or 400 p.p.m.) for 10 days. Food intake, body weight change, brain acetylcholinesterase activity, egg production, and ovary weight were reduced in a dose-dependent manner. In a second experiment, birds were fed 0, 25 or 100 p.p.m. parathion or pair-fed control food to equate consumption in the 100 p.p.m. group. Egg production was not affected in birds fed 25 p.p.m. or in the pair-fed group, but the daily time of oviposition was more variable than in the control group. Cessation of egg production, inhibition of follicular development, and reduced plasma LH concentration were observed in birds fed 100 p.p.m. parathion. These findings indicate that exposure to parathion can impair reproduction, possibly by altering gonadotrophin secretion.

  1. The abiotic degradation of methyl parathion in anoxic sulfur-containing system mediated by natural organic matter.

    PubMed

    Liao, Xiaoping; Zhang, Caixiang; Wang, Yanxin; Tang, Mi

    2017-06-01

    Although the kinetics and transformation of methyl parathion have been investigated extensively, its abiotic degradation mechanism in anoxic sulfur-containing groundwater system is still not clear. In this work, the abiotic degradation of methyl parathion in anoxic sulfur-containing system mediated by natural organic matter (NOM) was investigated in batch experiments. It was found that the removal of methyl parathion (up to 80.7%) was greatly improved in sulfide containing NOM compared to those in sulfide alone (with 15.5%) and in NOM alone (almost negligible). Various sulfur species presented significant differences in behaviors methyl parathion degradation, but followed by the pseudo-first-order model well. No facilitated degradation of methyl parathion was observed in sulfite (SO3(2-)) or thiosulfate (S2O3(2-)) containing NOM such as anthraquinone. Although elemental sulfur (S(0)) and cysteine could further improve the degradation rate of methyl parahtion, their impacts was very limited. The removal efficiency of methyl parathion in anoxic sulfur-containing system were related remarkably with NOM concentration and solution pH. Based on the transformation products identified by gas chromatography-mass spectrometer (GC/MS) and liquid chromatography high resolution mass spectrometer (LC/HRMS), both the nitro group reduction and hydrolysis (SN@C) processes by sulfide (HS(-)) were further proved to be two predominant reaction mechanisms for the abiotic degradation of methyl parathion in anoxic sulfur-containing system. The results of this study help to understand the natural attenuation of methyl parathion under anoxic sulfide-containing groundwater system mediated by NOM.

  2. Differential pulse voltammetric determination of methyl parathion based on multiwalled carbon nanotubes-poly(acrylamide) nanocomposite film modified electrode.

    PubMed

    Zeng, Yanbo; Yu, Dajun; Yu, Yanyan; Zhou, Tianshu; Shi, Guoyue

    2012-05-30

    A sensitive electrochemical differential pulse voltammetry method was developed for detecting methyl parathion based on multiwalled carbon nanotubes-poly(acrylamide) (MWCNTs-PAAM) nanocomposite film modified glassy carbon electrode. The novel MWCNTs-PAAM nanocomposite, containing high content of amide groups, was synthesized by PAAM polymerizing at the vinyl group functionalized MWCNTs surface using free radical polymerization. The MWCNTs-PAAM nanocomposite was characterized by Fourier transform infrared spectroscopy, thermal gravimetric analysis and scanning electron microscopy. Electrochemical behavior and interference studies of MWCNTs-PAAM/GCE for methyl parathion were investigated. The experimental results demonstrated that the MWCNTs-PAAM/GCE exhibited a high adsorption and strong affinity toward methyl parathion compared with some metal ions and nitroaromatic compounds, which exist in environmental samples. The adsorbed amount of methyl parathion on the MWCNTs-PAAM/GCE approached the equilibrium value upon 5 min adsorption time. A linear calibration curve for methyl parathion was obtained in the concentration range from 5.0×10(-9) to 1.0×10(-5) mol L(-1), with a detection limit of 2.0×10(-9) mol L(-1). The MWCNTs-PAAM/GCE was proved to be a suitable sensing tool for the fast, sensitive and selective determination of methyl parathion in environmental water samples.

  3. Ethyl parathion in wetlands following aerial application to sunflowers in North Dakota

    USGS Publications Warehouse

    Tome, M.W.; Grue, C.E.; DeWeese, L.R.

    1991-01-01

    An operational aerial application of parathion to sunflower fields resulted in greater or equal spray deposit in wetlands adjacent to or surrounded by sunflower fields than in the sunflower fields. In another application, when the applicator attempted to avoid contamination of the wetlands, parathion still drifted into wetlands in detectable amounts; in 2 of 4 comparisons, spray deposit in wetlands and sunflower fields did not differ. Weather during both spray operations was ideal for North Dakota, Le., wind speeds <16 km/ hour, excellent visibility, and temperature <24 C. We review how spray droplet size, weather, terrain, and type of application equipment interact to determine the amount of drift from any application of pesticide. With this information, wildlife managers should be able to make decisions pertaining to insecticide applications that will minimize drift and reduce negative impacts to nontarget organisms

  4. Quantitative NIR-Raman analysis of methyl-parathion pesticide microdroplets on aluminum substrates.

    PubMed

    Sato-Berrú, R Ysacc; Medina-Valtierra, Jorge; Medina-Gutiérrez, Cirilo; Frausto-Reyes, Claudio

    2004-08-01

    The potential of Raman spectroscopy in the quantitative analysis of dilute organic contaminants on aluminum substrates is evidenced in this work. Methyl-parathion microdroplets, an organophosphorus pesticide, has been used as a probe for this purpose. The samples were analyzed on an aluminum foil, which is very easy to acquire and to adapt. Moreover, aluminum foil does not need a previous treatment. Linear and no-linear curves as a function of the concentration of methyl-parathion versus the Raman intensity of the 1345 and 1110 cm(-1) peaks were established by means of a simple mathematical expression. A comparison with calibration curves fits very well, allowing quantification at concentration levels as low as parts per million.

  5. Physical comparison of parathion hydrolase plasmids from Pseudomonas diminuta and Flavobacterium sp.

    PubMed

    Mulbry, W W; Kearney, P C; Nelson, J O; Karns, J S

    1987-09-01

    Restriction maps of two plasmids encoding parathion hydrolase have been determined. pPDL2 is a 39-kb plasmid harbored by Flavobacterium sp. (ATCC 27551), while pCMS1 is a 70-kb plasmid found in Pseudomonas diminuta (strain MG). Both plasmids previously have been shown to share homologous parathion hydrolase genes (termed opd for organophosphate degradation) as judged by DNA-DNA hybridization and restriction mapping. In the present study, we conducted DNA hybridization experiments using each of nine PstI restriction fragments from pCMS1 as probes against Flavobacterium plasmid DNA. The opd genes of both plasmids are located within a highly conserved region of approximately 5.1 kb. This region of homology extends approximately 2.6 kb upstream and 1.7 kb downstream from the opd genes. No homology between the two plasmids is evident outside of this region.

  6. Photolytic degradation of methyl-parathion and fenitrothion in ice and water: implications for cold environments.

    PubMed

    Weber, Jan; Kurková, Romana; Klánová, Jana; Klán, Petr; Halsall, Crispin J

    2009-12-01

    Here we investigate the photodegradation of structurally similar organophosphorus pesticides; methyl-parathion and fenitrothion in water (20 degrees C) and ice (-15 degrees C) under environmentally-relevant conditions with the aim of comparing these laboratory findings to limited field observations. Both compounds were found to be photolyzed more efficiently in ice than in aqueous solutions, with quantum yields of degradation being higher in ice than in water (fenitrothion > methyl-parathion). This rather surprising observation was attributed to the concentration effect caused by freezing the aqueous solutions. The major phototransformation products included the corresponding oxons (methyl-paraoxon and fenitroxon) and the nitrophenols (3-methyl-nitrophenol and nitrophenol) in both irradiated water and ice samples. The presence of oxons in ice following irradiation, demonstrates an additional formation mechanism of these toxicologically relevant compounds in cold environments, although further photodegradation of oxons in ice indicates that photochemistry of OPs might be an environmentally important sink in cold environments.

  7. The Effect of Parathion on Red Blood Cell Acetylcholinesterase in the Wistar Rat

    PubMed Central

    Bunya, Naofumi; Sawamoto, Keigo; Benoit, Hanif

    2016-01-01

    Organophosphorus (OP) pesticide poisoning is a significant problem worldwide. Research into new antidotes for these acetylcholinesterase inhibitors, and even optimal doses for current therapies, is hindered by a lack of standardized animal models. In this study, we sought to characterize the effects of the OP pesticide parathion on acetylcholinesterase in a Wistar rat model that included comprehensive medical care. Methods. Male Wistar rats were intubated and mechanically ventilated and then poisoned with between 20 mg/kg and 60 mg/kg of intravenous parathion. Upon developing signs of poisoning, the rats were treated with standard critical care, including atropine, pralidoxime chloride, and midazolam, for up to 48 hours. Acetylcholinesterase activity was determined serially for up to 8 days after poisoning. Results. At all doses of parathion, maximal depression of acetylcholinesterase occurred at 3 hours after poisoning. Acetylcholinesterase recovered to nearly 50% of baseline activity by day 4 in the 20 mg/kg cohort and by day 5 in the 40 and 60 mg/kg cohorts. At day 8, most rats' acetylcholinesterase had recovered to roughly 70% of baseline. These data should be useful in developing rodent models of acute OP pesticide poisoning. PMID:27418928

  8. Methyl parathion and fenvalerate toxicity in American kestrels: Acute physiological responses and effects of cold

    USGS Publications Warehouse

    Rattner, B.A.; Franson, J.C.

    1984-01-01

    Physiological and toxicological effects of p.o. methyl parathion (0.375-3.0 mg/kg) or fenvalerate (1000-4000 mg/kg) were examined over a 10-h period in American kestrels (Falco sparverius) maintained in thermoneutral (22?C) and cold (-5?C) environments. Methyl parathion was highly toxic (estimated median lethal dose of 3.08 mg/kg, 95% confidence limits of 2.29 -4.14 mg/kg), producing dose-dependent inhibition of brain and plasma cholinesterase activity, hyperglycemia, and elevated plasma corticosterone concentration. Brain and plasma cholinesterase inhibition in excess of 50% was associated with transient but pronounced hypothermia 2 h after intubation, although the magnitude of this response was yariable. Fenvalerate, at doses far exceeding those encountered in the environment, caused mild intoxication and elevated plasma alanine aminotransferase activity. Cold intensified methyl parathion toxicity, but did not affect that of fenvalerate. Thus, it would appear that organophosphorus insecticides pose far greater hazard than pyrethroids to raptorial birds.

  9. The effect of methyl parathion on susceptibility of bobwhite quail (Colinus virginianus) to domestic cat predation.

    PubMed

    Galindo, J C; Kendall, R J; Driver, C J; Lacher, T E

    1985-01-01

    Bobwhite quail (Colinus virginianus) that received either 0, 2, 4, or 8 mg/kg methyl parathion (O,O-dimethyl o-p-nitrophenyl phosphorothioate) treatment were investigated as to their susceptibility to predation by a cat (Felis domesticus) predator. Four hours after receiving methyl parathion (MP), physical activity levels were monitored in quail and included the number of seconds spent still, walking, running, or flying before and after a cat was introduced into an experimental arena. The cholinesterase (ChE) activity for each quail on experiment was determined. Quail that were captured exhibited significantly greater inhibition of brain ChE activity and spent significantly more time being still than noncaptured birds. Birds receiving MP at 8 mg/kg spent more seconds being still than those in other treatment groups and had ChE activity reduced to 42.8% of normal activity. There was a tendency for quail at increasing treatment levels to be more susceptible to capture by the cat predator. The neurological and behavioral effects of methyl parathion may have important ecological ramifications.

  10. Aminoparathion: a highly reactive metabolite of parathion. 1. Reactions with polyphenols and polyphenol oxidase.

    PubMed

    Rung, Bruno; Schwack, Wolfgang

    2005-11-16

    Spiking of tomato and apple fruits with parathion at different levels of about 1-4 mg/kg irradiation and under simulated sunlight conditions resulted in nearly complete photodegradation within 13 h, but extractable parathion degradation products could not be found in any case. However, after irradiation of an unrealistically spiked apple (134 mg/kg) different photoproducts including aminoparathion (AP) were detectable by HPLC, proving that the hitherto postulated photochemistry of parathion indeed takes place in the fruit cuticle environment. Besides the photoreduction pathway it was shown for the first time that AP is also easily formed by reduction of the primary photoproduct nitrosoparathion with thiols (cysteine, glutathione), while ascorbic acid only leaves hydroxylaminoparathion. In the presence of polyphenols, AP was effectively bound to quinone intermediates formed by both silver oxide and polyphenol oxidases. For pyrocatechol, a disubstituted o-quinone derivative could be isolated as a dark red addition product and structurally be elucidated. However, in the presence of caffeic acid, catechol, naringin, and quercetin, respectively, insoluble dark colored polymers precipitated within 48 h, while in the supernatants AP was not detectable any more. Polymer-bound and nonextractable AP was proven by transesterification with sodium ethoxide releasing O,O,O-triethyl thiophosphate which was determined by GC. Additionally, AP itself was a substrate for polyphenol oxidases, resulting in a quinone imine intermediate which in turn reacted with excessive AP yielding deep red colored di- and trimerization products.

  11. Graphene quantum dot modified screen printed immunosensor for the determination of parathion.

    PubMed

    Mehta, Jyotsana; Bhardwaj, Neha; Bhardwaj, Sanjeev K; Tuteja, Satish K; Vinayak, Priya; Paul, A K; Kim, Ki-Hyun; Deep, Akash

    2017-02-02

    The widespread use of pesticides has immense effect on increased crop productions. However, they are also responsible for posing detrimental health hazards and/or for contaminating the environment with chemical residues. A routine and an on-field detection of pesticide residues in different food, water, and soil samples has become a need of the hour for which biosensors can offer a viable alternative. The present work reports a functionalized graphene quantum dot (GQD) based screen printed electrochemical immunosensor for the detection of parathion. The application of GQDs has permitted the realization of a sensitive, robust, and reproducible sensor unlike those carried out earlier for the similar purposes. This immunosensor exhibited a dynamic linear response for parathion within the range of 0.01-10(6) ng/L with a very low detection limit of 46 pg/L. According to the analysis of potential interferences, the proposed sensor was specifically detecting parathion even in the presence of its metabolite, paraoxon. The investigations of the proposed sensing approach with respect to stability, response reproducibility, and regeneration have fully supported its potential practical applicability.

  12. Detection of parathion pesticide by quartz crystal microbalance functionalized with UV-activated antibodies.

    PubMed

    Funari, Riccardo; Della Ventura, Bartolomeo; Schiavo, Luigi; Esposito, Rosario; Altucci, Carlo; Velotta, Raffaele

    2013-07-02

    Photonic immobilization technique (PIT) has been used to develop an immunosensor for the detection of parathion. An antibody solution has been activated by breaking the disulfide bridge in the triad Trp/Cys-Cys through absorption of ultrashort UV laser pulses. The free thiol groups so produced interact with gold lamina making the antibody oriented upside, that is, with its variable parts exposed to the environment, thereby greatly increasing the detection efficiency. PIT has been applied to anchor polyclonal antiparathion antibodies to the gold electrode of a Quartz Crystal Microbalance (QCM) giving rise to very high detection sensitivity once the parathion is made heavier by complexion with BSA (bovine serum albumin), this latter step only required by the mass based transducer used in this case. The comparison of the sensor response with irradiated antibodies against different analytes shows that the high degree of antibody specificity is not affected by PIT nor is it by the complexion of parathion with BSA. These results pave the way to important applications in biosensing, since the widespread occurrence of the Trp/Cys-Cys residues triads in proteins make our procedure very general and effective to detect light analytes.

  13. Biodegradation of lindane, methyl parathion and carbofuran by various enriched bacterial isolates.

    PubMed

    Krishna, K Rama; Philip, Ligy

    2008-02-01

    In the present study, lindane (1,2,3,4,5,6-hexachlorocyclohexane), methyl parathion (O-dimethylO-(4-nitro-phenyl) phosphorothioate) and carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate) degradation potential of different enriched bacterial cultures were evaluated under various environmental conditions. Enriched cultures behaved differently with different pesticides. Degradation was more in a facultative anaerobic condition as compared to that in aerobic condition. A specific pesticide enriched culture showed maximum degradation of that pesticide irrespective of pesticides and environmental conditions. Lindane and endosulfan enriched cultures behaved almost similarly. Degradation of lindane by lindane enriched cultures was 75 +/- 3% in aerobic co-metabolic process whereas 78 +/- 5% of lindane degradation occurred in anaerobic co-metabolic process. Degradation of methyl parathion by methyl parathion enriched culture was 87 +/- 1% in facultative anaerobic condition. In almost all the cases, many intermediate metabolites were observed. However, many of these metabolites disappeared after 4-6 weeks of incubation. Mixed pesticide-enriched culture degraded all the three pesticides more effectively as compared to specific pesticide- enriched cultures. It can be inferred from the results that a bacterial consortium enriched with a mixture of all the possible pesticides that are present in the site seems to be a better option for the effective bioremediation of multi-pesticide contaminated site.

  14. Kinetic-spectrophotometric determination of methyl parathion in water and vegetable samples.

    PubMed

    Tiwari, Neetu; Asthana, Anupama; Upadhyay, Kanchan

    2013-01-15

    A new selective and sensitive kinetic method has been developed for spectrophotometric determination of methyl parathion based on its inhibitory effect on the redox reaction between bromate and hydrochloric acid. The decolorization of neutral red by the reaction product was used to monitor the reaction spectrophotometrically at 530 nm by measuring the change in absorbance at the fixed time of 5 min after the initiation of the reaction. The variables affecting the rate of the reaction were investigated. Under the selected experimental conditions methyl parathion was determined in the range of 0.025-0.3 μg mL(-1). Sandell's sensitivity and molar absorptivity for the system were found to be 0.0004 μg cm(-2) and 6.5×10(5) L mol(-1) cm(-1) respectively. The proposed method was applied for the determination of methyl parathion in different vegetable and water samples with satisfactory results. The results were compared with those obtained by GC-MS, very similar values were found by the two methods.

  15. Comparative Effects of Parathion and Chlorpyrifos on Endocannabinoid and Endocannabinoid-Like Lipid Metabolites in Rat Striatum

    PubMed Central

    Liu, Jing; Parsons, Loren; Pope, Carey

    2015-01-01

    Parathion and chlorpyrifos are organophosphorus insecticides (OPs) that elicit acute toxicity by inhibiting acetylcholinesterase (AChE). The endocannabinoids (eCBs, N-arachidonoylethanolamine, AEA; 2-arachidonoylglycerol, 2AG) are endogenous neuromodulators that regulate presynaptic neurotransmitter release in neurons throughout the central and peripheral nervous systems. While substantial information is known about the eCBs, less is known about a number of endocannabinoid-like metabolites (eCBLs, e.g., N-palmitoylethanolamine, PEA; N-oleoylethanolamine, OEA). We report the comparative effects of parathion and chlorpyrifos on AChE and enzymes responsible for inactivation of the eCBs, fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), and changes in the eCBs AEA and 2AG and eCBLs PEA and OEA, in rat striatum. Adult, male rats were treated with vehicle (peanut oil, 2 ml/kg, sc), parathion (27 mg/kg) or chlorpyrifos (280 mg/kg) 6-7 days after surgical implantation of microdialysis cannulae into the right striatum, followed by microdialysis two or four days later. Additional rats were similarly treated and sacrificed for evaluation of tissue levels of eCBs and eCBLs. Dialysates and tissue extracts were analyzed by LC-MS/MS. AChE and FAAH were extensively inhibited at both time-points (85-96%), while MAGL activity was significantly but lesser affected (37-62% inhibition) by parathion and chlorpyrifos. Signs of toxicity were noted only in parathion-treated rats. In general, chlorpyrifos increased eCB levels while parathion had no or lesser effects. Early changes in extracellular AEA, 2AG and PEA levels were significantly different between parathion and chlorpyrifos exposures. Differential changes in extracellular and/or tissue levels of eCBs and eCBLs could potentially influence a number of signaling pathways and contribute to selective neurological changes following acute OP intoxications. PMID:26215119

  16. Comparative effects of parathion and chlorpyrifos on endocannabinoid and endocannabinoid-like lipid metabolites in rat striatum.

    PubMed

    Liu, Jing; Parsons, Loren; Pope, Carey

    2015-09-01

    Parathion and chlorpyrifos are organophosphorus insecticides (OPs) that elicit acute toxicity by inhibiting acetylcholinesterase (AChE). The endocannabinoids (eCBs, N-arachidonoylethanolamine, AEA; 2-arachidonoylglycerol, 2AG) are endogenous neuromodulators that regulate presynaptic neurotransmitter release in neurons throughout the central and peripheral nervous systems. While substantial information is known about the eCBs, less is known about a number of endocannabinoid-like metabolites (eCBLs, e.g., N-palmitoylethanolamine, PEA; N-oleoylethanolamine, OEA). We report the comparative effects of parathion and chlorpyrifos on AChE and enzymes responsible for inactivation of the eCBs, fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), and changes in the eCBs AEA and 2AG and eCBLs PEA and OEA, in rat striatum. Adult, male rats were treated with vehicle (peanut oil, 2 ml/kg, sc), parathion (27 mg/kg) or chlorpyrifos (280 mg/kg) 6-7 days after surgical implantation of microdialysis cannulae into the right striatum, followed by microdialysis two or four days later. Additional rats were similarly treated and sacrificed for evaluation of tissue levels of eCBs and eCBLs. Dialysates and tissue extracts were analyzed by LC-MS/MS. AChE and FAAH were extensively inhibited at both time-points (85-96%), while MAGL activity was significantly but lesser affected (37-62% inhibition) by parathion and chlorpyrifos. Signs of toxicity were noted only in parathion-treated rats. In general, chlorpyrifos increased eCB levels while parathion had no or lesser effects. Early changes in extracellular AEA, 2AG and PEA levels were significantly different between parathion and chlorpyrifos exposures. Differential changes in extracellular and/or tissue levels of eCBs and eCBLs could potentially influence a number of signaling pathways and contribute to selective neurological changes following acute OP intoxications.

  17. Plasmid-borne catabolism of methyl parathion and p-nitrophenol in Pseudomonas sp. strain WBC-3.

    PubMed

    Liu, Hong; Zhang, Jun-Jie; Wang, Su-Jun; Zhang, Xian-En; Zhou, Ning-Yi

    2005-09-09

    Pseudomonas sp. strain WBC-3 utilises methyl parathion (MP) or p-nitrophenol (PNP) as the sole source of carbon, nitrogen, and energy. A plasmid designated pZWL0 of approximately 70 kb in this strain was found to be responsible for MP and PNP degradation. This was based on the fact that the plasmid-cured strains showed PNP- MP- phenotype and the PNP+ MP+ phenotype could be conjugally transferred. We have also cloned a 3.4-kb HindIII fragment which exhibited methyl parathion hydrolase activity, which revealed a methyl parathion hydrolase (mph) gene whose DNA sequence is 99.5% identical to the recently identified mpd gene from Plesiomonas sp. M6 [C. Zhongli, L. Shunpeng, F. Guoping, Isolation of methyl parathion-degrading strain M6 and cloning of the methyl parathion hydrolase gene, Appl. Environ. Microbiol. 67 (2001) 4922-4925]. The mph gene was functionally expressed in Escherichia coli and the relative activities of the enzyme against different substrates were determined. The sequence alignment and phylogenetic analysis suggested that MPH and MPD evolved independently from other well-studied organophosphate hydrolases and may be originated from class B beta-lactamase family. Subsequently obtained a 6.5-kb KpnI and BamHI fragment containing the above HindIII fragment revealed that the mph gene was physically located in a typical transposon.

  18. Covalent Coupling of Organophosphorus Hydrolase Loaded Quantum Dots to Carbon Nanotube/Au Nanocomposite for Enhanced Detection of Methyl Parathion

    SciTech Connect

    Du, Dan; Chen, Wenjuan; Zhang, Weiying; Liu, Deli; Li, Haibing; Lin, Yuehe

    2010-02-15

    An amperometric biosensor for highly selective and sensitive determination of methyl parathion (MP) was developed based on dual signal amplification: (1) a large amount of introduced enzyme on the electrode surface and (2) synergistic effects of nanoparticles towards enzymatic catalysis. The fabrication process includes (1) electrochemical deposition of gold nanoparticles by a multi-potential step technique at multiwalled carbon nanotube (MWCNT) film pre-cast on a glassy carbon electrode and (2) immobilization of methyl parathion degrading enzyme (MPDE) onto a modified electrode through CdTe quantum dots (CdTe QDs) covalent attachment. The introduced MWCNT and gold nanoparticles significantly increased the surface area and exhibited synergistic effects towards enzymatic catalysis. CdTe QDs are further used as carriers to load a large amount of enzyme. As a result of these two important enhancement factors, the proposed biosensor exhibited extremely sensitive, perfectly selective, and rapid response to methyl parathion in the absence of a mediator.

  19. Kinetic analyses of the microsomal biotransformation of the phosphorothioate insecticides chlorpyrifos and parathion.

    PubMed

    Sultatos, L G; Murphy, S D

    1983-01-01

    Chlorpyrifos [0,0-diethyl-0-(3,5,6-trichloro-2-pyridyl) phosphorothioate] was metabolized to chlorpyrifos oxon [0,0-diethyl-0-(3,5,6-trichloro-2-pyridyl) phosphate] and to 3,5,6-trichloro-2-pyridinol by mouse hepatic microsomes. Formation of both chlorpyrifos oxon and 3,5,6-trichloro-2-pyridinol required NADPH, and was inhibited by carbon monoxide. Kinetic analyses using direct linear plots determined the appKm's for formation of chlorpyrifos oxon and 3,5,6-trichloro-2-pyridinol to be 20.9 +/- 3.3 microM and 16.1 +/- 3.4 microM respectively, while the appVmax's for the same reactions were 3.9 +/- 0.2 nmols/100 mg liver/min and 8.1 +/- 0.3 nmols/100 mg liver/min respectively. Incubation of parathion [0,0-diethyl-0-(4-nitrophenyl) phosphorothioate] with mouse hepatic microsomes produced paraoxon [0,0-diethyl-0-(4-nitrophenyl) phosphate] and p-nitrophenol. The appKm's for the formation of paraoxon and p-nitrophenol were 29.6 +/- 4.2 microM and 26.5 +/- 3.8 microM respectively, with appVmax's of 5.8 +/- 0.6 nmols/100 mg liver/min and 6.7 +/- 0.5 nmols/100 mg liver/min, respectively. Incubation of both parathion and chlorpyrifos at various concentrations with mouse hepatic microsomes resulted in inhibition of production of paraoxon, p-nitrophenol, chlorpyrifos oxon, and 3,5,6-trichloro-2-pyridinol, which was characteristic of mixed type inhibition. This complex kinetic behavior could arise as a result of competitive interactions of parathion and chlorpyrifos with multiple forms of microsomal cytochrome P-450.

  20. Cholinesterase inhibition of birds inhabiting wheat fields treated with methyl parathion and toxaphene

    USGS Publications Warehouse

    Niethammer, K.R.; Baskett, T.S.

    1983-01-01

    Red-winged blackbirds (Agelaius phoeniceus) and dickcissels (Spiza americana) inhabiting wheat fields treated with 0.67 kg AI/ha methyl parathion and 1.35 kg AI/ha toxaphene showed brain cholinesterase (ChE) inhibition compared with birds inhabiting untreated fields. Maximum inhibition occurred about five days after insecticide application. ChE activities again approached normal 10 days after treatment. ChE inhibition for dickcissels and red-winged blackbirds differed significantly (p<0.05); maximum inhibition for the former species was 74%, and for the latter, 40%. These differences could not be explained by the diets of the two species, as they were similar.

  1. A receptor binding assay applied to monitoring the neurotoxicity of parathion to Peromyscus after oral exposure

    USGS Publications Warehouse

    Jett, D.A.; Eldefrawi, A.T.; Eldefrawi, M.E.

    1993-01-01

    Many naturally occurring toxins, as well as pesticides, metals, and other compounds that occur in our environment from anthropogenic activities, stimulate or antagonize neuro-receptors to produce acute and/or chronic toxicities. Recent advances in laboratory instrumentation and the availability of a variety of radiolabeled ligands and type-specific drugs for numerous receptors make it possible to easily screen large numbers of samples and detect changes in sensitivity and density of receptor types and subtypes. A receptor binding assay for examining the chronic dietary toxicity of parathion will be used as a model to describe the methodology.

  2. Sonocatalytic degradation of methyl parathion in the presence of nanometer and ordinary anatase titanium dioxide catalysts and comparison of their sonocatalytic abilities.

    PubMed

    Wang, Jun; Pan, Zhijun; Zhang, Zhaohong; Zhang, Xiangdong; Wen, Fuyu; Ma, Teng; Jiang, Yuefeng; Wang, Lei; Xu, Liang; Kang, Pingli

    2006-09-01

    The degradation of methyl parathion (O,O-dimethyl-O-(4-nitrophenyl)-phosphorothioate) using anatase titanium dioxide (TiO(2)) powder as heterogeneous sonocatalysts is reported. The influences of reaction parameters such as the species of TiO(2) sonocatalysts, methyl parathion concentrations, TiO(2) adding amount, pH, ultrasonic intensity, ultrasonic frequency and temperature have been investigated and the optimal conditions for eliminating methyl parathion have been identified. The efficiencies of sonocatalytic degradation in both nanometer and ordinary anatase systems are compared and the results indicate that the sonocatalytic activity of nanometer anatase TiO(2) powder is better than that of ordinary anatase TiO(2) powder. The primary degradation and the total mineralization of methyl parathion have been monitored by high performance liquid chromatography (HPLC) and UV-vis spectra, respectively. Methyl parathion got destroyed to some extent in both nanometer and ordinary anatase systems under ultrasonic irradiation. The kinetics for the degradation process of methyl parathion follows the first-order reaction. The degradation ratio of methyl parathion surpassed 90% within 50min in the optimal experiment conditions.

  3. Parathion hydrolase specified by the Flavobacterium opd gene: relationship between the gene and protein.

    PubMed Central

    Mulbry, W W; Karns, J S

    1989-01-01

    The sequence of a 1,693-base-pair plasmid DNA fragment from Flavobacterium sp. strain ATCC 27551 containing the parathion hydrolase gene (opd) was determined. Within this sequence, there is only one open reading frame large enough to encode the 35,000-dalton membrane-associated hydrolase protein purified from Flavobacterium extracts. Amino-terminal sequence analysis of the purified Flavobacterium hydrolase demonstrated that serine is the amino-terminal residue of the hydrolase protein. The amino-terminal serine corresponds to a TCG codon located 87 base pairs downstream of the presumptive ATG initiation codon in the nucleotide sequence. The amino acid composition of the purified protein agrees well with that predicted from the nucleotide sequence, using serine as the amino-terminal residue. These data suggest that the parathion hydrolase protein is processed at its amino terminus in Flavobacterium sp. Construction in Escherichia coli of a lacZ-opd gene fusion in which the first 33 amino-terminal residues of opd were replaced by the first 5 residues of lacZ resulted in the production of an active hydrolase identical in molecular mass to the hydrolase isolated from Flavobacterium sp. E. coli cells containing the lacZ-opd fusion showed higher levels of hydrolase activity than did cells containing the parent plasmid. Images PMID:2556372

  4. Parathion hydrolase specified by the Flavobacterium opd gene: relationship between the gene and protein.

    PubMed

    Mulbry, W W; Karns, J S

    1989-12-01

    The sequence of a 1,693-base-pair plasmid DNA fragment from Flavobacterium sp. strain ATCC 27551 containing the parathion hydrolase gene (opd) was determined. Within this sequence, there is only one open reading frame large enough to encode the 35,000-dalton membrane-associated hydrolase protein purified from Flavobacterium extracts. Amino-terminal sequence analysis of the purified Flavobacterium hydrolase demonstrated that serine is the amino-terminal residue of the hydrolase protein. The amino-terminal serine corresponds to a TCG codon located 87 base pairs downstream of the presumptive ATG initiation codon in the nucleotide sequence. The amino acid composition of the purified protein agrees well with that predicted from the nucleotide sequence, using serine as the amino-terminal residue. These data suggest that the parathion hydrolase protein is processed at its amino terminus in Flavobacterium sp. Construction in Escherichia coli of a lacZ-opd gene fusion in which the first 33 amino-terminal residues of opd were replaced by the first 5 residues of lacZ resulted in the production of an active hydrolase identical in molecular mass to the hydrolase isolated from Flavobacterium sp. E. coli cells containing the lacZ-opd fusion showed higher levels of hydrolase activity than did cells containing the parent plasmid.

  5. Altering the substrate specificity of methyl parathion hydrolase with directed evolution.

    PubMed

    Ng, Tee-Kheang; Gahan, Lawrence R; Schenk, Gerhard; Ollis, David L

    2015-05-01

    Many organophosphates (OPs) are used as pesticides in agriculture. They pose a severe health hazard due to their inhibitory effect on acetylcholinesterase. Therefore, detoxification of water and soil contaminated by OPs is important. Metalloenzymes such as methyl parathion hydrolase (MPH) from Pseudomonas sp. WBC-3 hold great promise as bioremediators as they are able to hydrolyze a wide range of OPs. MPH is highly efficient towards methyl parathion (1 × 10(6) s(-1) M(-1)), but its activity towards other OPs is more modest. Thus, site saturation mutagenesis (SSM) and DNA shuffling were performed to find mutants with improved activities on ethyl paraxon (6.1 × 10(3) s(-1) M(-1)). SSM was performed on nine residues lining the active site. Several mutants with modest activity enhancement towards ethyl paraoxon were isolated and used as templates for DNA shuffling. Ultimately, 14 multiple-site mutants with enhanced activity were isolated. One mutant, R2F3, exhibited a nearly 100-fold increase in the kcat/Km value for ethyl paraoxon (5.9 × 10(5) s(-1) M(-1)). These studies highlight the 'plasticity' of the MPH active site that facilitates the fine-tuning of its active site towards specific substrates with only minor changes required. MPH is thus an ideal candidate for the development of an enzyme-based bioremediation system.

  6. Photochemical nitro-nitrite rearrangement in methyl parathion decay under tropical conditions.

    PubMed

    Araújo, Thiago M R; Canela, Maria C; Miranda, Paulo C M L

    2013-01-01

    This work presents a study of the abiotic degradation of commercially available methyl parathion in aqueous solution at two different concentrations (88 mg/L and 200 μg/L). The effects of solar irradiation and the presence of humic acids were evaluated and revealed a synergistic response between them. The half-life of methyl parathion ranged from 4.9 to 37 days, and the experimental data also show that photochemical processes were the most relevant in this case. The only byproduct found in samples submitted to shadowed conditions was 4-nitrophenol. On the other hand, 4-nitrophenol, methyl paraoxon and a new degradation product (O,O-dimethyl O-p-hydroxyphenyl phosphorothioate) were detected when the samples were exposed directly to sunlight. This newly identified compound was prepared in the laboratory by thiophosphorylation of hydroquinone, and coelution experiments with authentic samples provided unambiguous confirmation of the presence of O,O-dimethyl O-p-hydroxy phenylphosphorothioate in samples.

  7. [Construction of a stable genetically engineered microorganism for degrading HCH & methyl parathion and its characteristics].

    PubMed

    Lu, Peng; Hong, Yuan-Fan; Hong, Qing; Jiang, Xin; Li, Shun-Peng

    2008-07-01

    A GEM designated as BHC-A-mpd, capable of simultaneously degrading of methyl parathion (MP) and HCH was successfully constructed by random insertion of a methyl parathion hydrolase gene (mpd) into chromosome of a HCH-degrading strain BHC-A with the mini-Tn-transposon system. The growth and degrading characteristics of BHC-A-mpd was compared with the original strain BHC-A, and the result showed that there was no difference in this two aspects, A600 nm of BHC-A-mpd in LB medium could reach 2.5 in logarithmic period, which was the same as that of the original strain BHC-A.BHC-A-mpd showed the same HCH-degrading ability as BHC-A and could degrade 5 mg/L of gamma-HCH in 10 h. BHC-A-mpd showed high genetica stability and could degrade many kinds of organophosphorus pesticides. All these results indicated that BHC-A-mpd was a promising GEM in bioremediation of MP and HCH co-contaminated environment.

  8. ABCB1 and ABCC4 efflux transporters are involved in methyl parathion detoxification in ZFL cells.

    PubMed

    Nornberg, Bruna Félix; Batista, Carolina Reyes; Almeida, Daniela Volcan; Trindade, Gilma Santos; Marins, Luis Fernando

    2015-02-01

    The multi-xenobiotics resistance (MXR) mechanisms are the first line of defense against toxic substances in aquatic organisms and present great importance in the adaptation related to contaminated environments. Methyl parathion (MP) is a widely used organophosphate pesticide, which has been associated to various toxic effects in organisms. In the present work, we studied the main genes related to efflux transporters in zebrafish liver (ZFL) cells exposed to MP with and without an inhibitor of ABC transporters (verapamil). The results concerning transporters activity showed that the MXR mechanism is activated to detoxify from methyl parathion. The toxic effects of MP on ZFL cells were increased in the presence of the efflux transporter inhibitor, once cell viability was significantly decreased in co-exposure experiments. The combined exposure to MP and the inhibitor caused an increase in gene expression of P-gp1 (Abcb1) and MRP4 (Abcc4), suggesting that these transporters isoforms are associated with MP efflux. In general, the expression of genes related to the antioxidant defense system (ADS) was significantly increased in ZFL cells co-exposed to MP and verapamil. These data provide useful insights for better understanding of MP detoxification mechanism in fish hepatocytes.

  9. Isolation of a selected microbial consortium capable of degrading methyl parathion and p-nitrophenol from a contaminated soil site.

    PubMed

    Pino, Nancy J; Dominguez, Maria C; Penuela, Gustavo A

    2011-01-01

    A bacterial consortium with the ability to degrade methyl parathion and p-nitrophenol, using these compounds as the only carbon source, was obtained by selective enrichment in a medium with methyl parathion. Samples were taken from Moravia, Medellin; an area that is highly contaminated, owing to the fact that it was used as a garbage dump from 1974 to 1982. Acinetobacter sp, Pseudomonas putida, Bacillus sp, Pseudomonas aeruginosa Citrobacter freundii, Stenotrophomonas sp, Flavobacterium sp, Proteus vulgaris, Pseudomonas sp, Acinetobacter sp, Klebsiella sp and Proteus sp were the microorganisms identified within the consortium. In culture, the consortium was able to degrade 150 mg L⁻¹ of methyl-parathion and p-nitrophenol in 120 h, but after adding glucose or peptone to the culture, the time of degradation decreased to 24 h. In soil, the consortium was also able to degrade 150 mg L⁻¹ of methyl parathion in 120 h at different depths and also managed to decrease the toxicity.

  10. The interaction of methyl-parathion with serum and albumin of the neo-tropical fish Piaractus mesopotamicus.

    PubMed

    Silva, Dilson; Cortez-Moreira, Madelayne; Cunha Bastos, Vera L F; Cunha Bastos, Jayme; Martins Cortez, Célia

    2010-01-01

    The interaction of methyl-parathion with serum and albumin of pacu, Piaractus mesopotamicus, was studied, using the fluorescence quenching technique. Pacu is a neo-tropical fish specie inhabitant of rivers from western regions of Brazil. Methyl-parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) is an organophosphorous pesticide still used in agriculture and fish farming in many countries. The quenching of fluorescence can be mathematically expressed by the Stern-Volmer equation to calculate quenching constants. Stern-Volmer curves analysis is able to give important information about the pesticide-albumin interaction. Our results showed that the serum quenching reached 10% when the molar ratio of pesticide/albumin was about 7:1 for the three temperatures of the experiment. For the pure albumin quenching of 10%, methyl-parathion concentrations were 6, 7 and 9 times higher than albumin at 20, 25 and 30 degrees C, respectively. The calculated Stern-Volmer constants at 25 degrees C were 9.73x10(3)(+/-4.9x10(2))M(-1) for serum and 9.20x10(3)(+/-2.0x10(2))M(-1) for albumin. It was observed that albumin quenching is the phenomenon contributing to the quenching of the pacu serum fluorescence for methyl-parathion concentration lower than 10microM, suggesting that the protein is the most important carrier for the pesticide in serum.

  11. Interactive toxicity of chlorpyrifos and parathion in neonatal rats: Role of esterases in exposure sequence-dependent toxicity

    SciTech Connect

    Kacham, R.; Karanth, S.; Baireddy, P.; Liu, J.; Pope, C. . E-mail: carey.pope@okstate.edu

    2006-01-15

    We previously reported that sequence of exposure to chlorpyrifos and parathion in adult rats can markedly influence toxic outcome. In the present study, we evaluated the interactive toxicity of chlorpyrifos (8 mg/kg, po) and parathion (0.5 mg/kg, po) in neonatal (7 days old) rats. Rats were exposed to the insecticides either concurrently or sequentially (separated by 4 h) and sacrificed at 4, 8, and 24 h after the first exposure for biochemical measurements (cholinesterase activity in brain, plasma, and diaphragm and carboxylesterase activity in plasma and liver). The concurrently-exposed group showed more cumulative lethality (15/24) than either of the sequential dosing groups. With sequential dosing, rats treated initially with chlorpyrifos prior to parathion (C/P) exhibited higher lethality (7/23) compared to those treated with parathion before chlorpyrifos (P/C; 1/24). At 8 h after initial dosing, brain cholinesterase inhibition was significantly greater in the C/P group (59%) compared to the P/C group (28%). Diaphragm and plasma cholinesterase activity also followed a relatively similar pattern of inhibition. Carboxylesterase inhibition in plasma and liver was relatively similar among the treatment groups across time-points. Similar sequence-dependent differences in brain cholinesterase inhibition were also noted with lower binary exposures to chlorpyrifos (2 mg/kg) and parathion (0.35 mg/kg). In vitro and ex vivo studies compared relative oxon detoxification of carboxylesterases (calcium-insensitive) and A-esterases (calcium-sensitive) in liver homogenates from untreated and insecticide pretreated rats. Using tissues from untreated rats, carboxylesterases detoxified both chlorpyrifos oxon and paraoxon, while A-esterases only detoxified chlorpyrifos oxon. With parathion pretreatment, A-esterases still detoxified chlorpyrifos oxon while liver from chlorpyrifos pretreated rats had little apparent effect on paraoxon. We conclude that while neonatal rats are less

  12. Multivariate optimization of molecularly imprinted polymer solid-phase extraction applied to parathion determination in different water samples.

    PubMed

    Alizadeh, Taher; Ganjali, Mohammad Reza; Nourozi, Parviz; Zare, Mashaalah

    2009-04-13

    In this work a parathion selective molecularly imprinted polymer was synthesized and applied as a high selective adsorber material for parathion extraction and determination in aqueous samples. The method was based on the sorption of parathion in the MIP according to simple batch procedure, followed by desorption by using methanol and measurement with square wave voltammetry. Plackett-Burman and Box-Behnken designs were used for optimizing the solid-phase extraction, in order to enhance the recovery percent and improve the pre-concentration factor. By using the screening design, the effect of six various factors on the extraction recovery was investigated. These factors were: pH, stirring rate (rpm), sample volume (V(1)), eluent volume (V(2)), organic solvent content of the sample (org%) and extraction time (t). The response surface design was carried out considering three main factors of (V(2)), (V(1)) and (org%) which were found to be main effects. The mathematical model for the recovery percent was obtained as a function of the mentioned main effects. Finally the main effects were adjusted according to the defined desirability function. It was found that the recovery percents more than 95% could be easily obtained by using the optimized method. By using the experimental conditions, obtained in the optimization step, the method allowed parathion selective determination in the linear dynamic range of 0.20-467.4 microg L(-1), with detection limit of 49.0 ng L(-1) and R.S.D. of 5.7% (n=5). Parathion content of water samples were successfully analyzed when evaluating potentialities of the developed procedure.

  13. Neonatal Exposure to Parathion Alters Lipid Metabolism in Adulthood: Interactions with Dietary Fat Intake and Implications for Neurodevelopmental Deficits

    PubMed Central

    Lassiter, T. Leon; Ryde, Ian T.; Levin, Edward D.; Seidler, Frederic J.; Slotkin, Theodore A.

    2009-01-01

    Organophosphates are developmental neurotoxicants but recent evidence also points to metabolic dysfunction. We determined whether neonatal parathion exposure in rats has long-term effects on regulation of adipokines and lipid peroxidation. We also assessed the interaction of these effects with increased fat intake. Rats were given parathion on postnatal days 1–4 using doses (0.1 or 0.2 mg/kg/day) that straddle the threshold for barely detectable cholinesterase inhibition and the first signs of systemic toxicity. In adulthood, animals were either maintained on standard chow or switched to a high-fat diet for seven weeks. We assessed serum leptin and adiponectin, tumor necrosis factor-α (TNFα) in adipose tissues, and thiobarbituric acid reactive species (TBARS) in peripheral tissues and brain regions. Neonatal parathion exposure uncoupled serum leptin levels from their dependence on body weight, suppressed adiponectin and elevated TNFα in white adipose tissue. Some of the effects were offset by a high-fat diet. Parathion reduced TBARS in the adipose tissues, skeletal muscle and temporal/occipital cortex but not in heart, liver, kidney or frontal/parietal cortex; it elevated TBARS in the cerebellum; the high-fat diet again reversed many of the effects. Neonatal parathion exposure disrupts the regulation of adipokines that communicate metabolic status between adipose tissues and the brain, while also evoking an inflammatory adipose response. Our results are consistent with impaired fat utilization and prediabetes, as well as exposing a potential relationship between effects on fat metabolism and on synaptic function in the brain. PMID:19615431

  14. Evaluation of the susceptibility of the cultured shrimp Litopenaeus vannamei to vibriosis when orally exposed to the insecticide methyl parathion.

    PubMed

    Roque, A; Abad, S; Betancourt-Lozano, M; de la Parra, L M Garcia; Baird, D; Guerra-Flores, A L; Gomez-Gil, B

    2005-06-01

    The causes of disease in cultured shrimp are difficult to ascertain but there is evidence that disease is correlated with environmental factors. Crustaceans are particularly sensitive to insecticides due to their close phylogenetic relationship with insects. The objective of this study was to investigate whether there was an increased susceptibility of the shrimp Litopenaeus vannamei to Vibrio parahaemolyticus, when exposed to methyl parathion. The outline of the study was the following: An LC50 96 h was determined to methyl parathion orally offered to juvenile shrimp. Further experiments were carried out in order to determine a concentration that affected the shrimp (verified by measuring the acethylcholinesterase activity) while producing minimal mortalities. This sublethal concentration was used in a susceptibility experiment where methyl parathion was offered to shrimp which were later injected with V. parahaemolyticus in a dose expected to kill less than 15%. Probit analysis estimated a 96 h median lethal concentration (LC50) of 1.56 microg g(-1). Mortality and AChE activity showed a concentration-response relationship in the exposure treatments. The median inhibitory concentration (IC50) determined was 0.029 microg g(-1). These results suggested that a concentration of 0.1 microg g(-1) was appropriate for the bacteria-pesticide interaction test as it was able to elicit 11.1% mortality after 10 days of exposure, while producing an AChE inhibition of 57.12%. Cumulative mortalities were significantly increased (P<0.01) in the treatment that combined exposure to methyl parathion and V. parahaemolyticus (35.19%) in comparison with methyl parathion or V. parahaemolyticus alone (9.26% and 7.41%, respectively).

  15. Study of Degradation Kinetics of Parathion Methyl On Mixed Nanocrystalline Titania-Zirconium and Titania-Cerium Oxides

    NASA Astrophysics Data System (ADS)

    Kuráň, Pavel; Pšenička, Martin; Šťastný, Martin; Benkocká, Monika; Janoš, Pavel

    2016-10-01

    The unique surface properties of some nanocrystalline metal oxides and their application for removal of various toxic compounds were reported in early 1990s. Recently, a reliable method for the preparation of reactive cerium dioxide sorbent and its application for degradation of the organophosphate pesticides, such as parathion methyl, chlorpyrifos, dichlofenthion, fenchlorphos, and prothiofos, as well as of some chemical warfare agents-nerve gases soman and O-ethyl S-[2-(diisopropylamino) ethyl] methylphosphonothioate (VX) was published. This paper reports on the kinetics study of degradation of parathion methyl as a representative organophosphate on nanocrystalline metal oxides TiO2, ZrO2, CeO2 and their mixtures in different molar ratios of particular elements. The tested sorbents except of CeO2 were prepared by different methods (e.g. sol-gel, precipitation) in cooperation with Institute of Inorganic Chemistry (Rez, Czech Republic). The degradation kinetics of parathion methyl on tested sorbents was followed by HPLC equipped with diode array detector. The basic kinetics parameters (half-lives of parathion methyl degradation, rate constants of degradation product formation) were calculated for each sorbent from Weber-Morris equation of 1st order diffusion kinetic model. The results proved the ability of prepared sorbents to degrade parathion methyl under formation of 4-nitrophenol as the main degradation product. The most efficient sorbents were TiCe (2:8), TiCe (1:1), TiCe (0:1) (50-70 %) followed by TiZr (1:1), TiCe (8:2), TiZr (8:2), TiZr (2:8) (20-30%) and TiO2, ZrO2 (less than 5 %).

  16. Competition of a parathion-hydrolyzing Flavobacterium with bacteria from ditch water in carbon-, nitrate- and phosphate-limited continuous cultures.

    PubMed

    Sprenger, Wander W; Dijkstra, Annereinou; Zwart, Gabriel J M; Agterveld, Miranda P; Noort, Paul C M; Parsons, John R

    2003-02-01

    Abstract The effect of competition for macroelements with bacteria from ditch water on the parathion-hydrolyzing Flavobacterium sp. ATCC 27551 (FB) was investigated within mixed continuous cultures under carbon-, nitrate- or phosphate-limited conditions. The high initial rate of parathion hydrolysis decreased rapidly in all cultures due to the loss of strain FB. Addition of 2-isopropyl-6-methyl-4-pyrimidinol (a selective source of carbon, nitrogen and energy for FB) to one nitrate- and carbon-limited chemostat caused a 20-fold increase in parathion-hydrolyzing activity compared to unamended control cultures and retention of FB. The presence of the parathion hydrolase-encoding gene could be demonstrated by a newly developed PCR detection method in all FB cultures during most of the cultivation period. These results suggest that competition effects cause the pesticide-degrading capacity of microbial communities depending on their frequency of exposure to the pesticide compounds.

  17. Toxicity of parathion on embryo and yolk-sac larvae of gilthead seabream (Sparus aurata l.): effects on survival, cholinesterase, and carboxylesterase activity.

    PubMed

    Arufe, M Isabel; Arellano, Juana M; Albendín, Gemma; Sarasquete, Carmen

    2010-12-01

    This study was conducted to examine the acute toxicity of the organophosphorus pesticide (OP) parathion on embryos and yolk-sac larvae of gilthead seabream (Sparus aurata), and to investigate the effects of this compound on cholinesterase and carboxylesterase activity of seabream larvae in the phase of endogenous feeding. The 72-h LC50 for yolk-sac larvae (0.523 mg L⁻¹) was about two-fold lower than the 48-h LC50 for embryos (1.005 mg L⁻¹). Parathion significantly inhibited the activity of ChE and CaE activity in yolk sac larvae but there were not significant differences in the sensitivity of both esterases to parathion as inferred by their 72-h IC50 values. Larvae exposed to parathion for 72 h showed a 70% inhibition of the whole body acetylcholinesterase at approximately the LC50.

  18. Accelerating the initial rate of hydrolysis of methyl parathion with laser excitation using monolayer protected 10 nm Au nanoparticles capped with a Cu(bpy) catalyst.

    PubMed

    Trammell, Scott A; Nita, Rafaela; Moore, Martin; Zabetakis, Dan; Chang, Eddie; Knight, D Andrew

    2012-04-28

    Using a low power green laser, we have demonstrated a rate acceleration of ~2-fold for the hydrolysis of methyl parathion by irradiating the plasmon absorption band of Au nanoparticles capped with a Cu(bpy) catalyst.

  19. Human hepatic cytochrome P450-specific metabolism of the organophosphorus pesticides methyl parathion and diazinon.

    PubMed

    Ellison, Corie A; Tian, Yuan; Knaak, James B; Kostyniak, Paul J; Olson, James R

    2012-01-01

    Organophosphorus pesticides (OPs) are a public health concern due to their worldwide use and documented human exposures. Phosphorothioate OPs are metabolized by cytochrome P450s (P450s) through either a dearylation reaction to form an inactive metabolite, or through a desulfuration reaction to form an active oxon metabolite, which is a potent cholinesterase inhibitor. This study investigated the rate of desulfuration (activation) and dearylation (detoxification) of methyl parathion and diazinon in human liver microsomes. In addition, recombinant human P450s were used to determine the P450-specific kinetic parameters (K(m) and V(max)) for each compound for future use in refining human physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models of OP exposure. The primary enzymes involved in bioactivation of methyl parathion were CYP2B6 (K(m) = 1.25 μM; V(max) = 9.78 nmol · min(-1) · nmol P450(-1)), CYP2C19 (K(m) = 1.03 μM; V(max) = 4.67 nmol · min(-1) · nmol P450(-1)), and CYP1A2 (K(m) = 1.96 μM; V(max) = 5.14 nmol · min(-1) · nmol P450(-1)), and the bioactivation of diazinon was mediated primarily by CYP1A1 (K(m) = 3.05 μM; V(max) = 2.35 nmol · min(-1) · nmol P450(-1)), CYP2C19 (K(m) = 7.74 μM; V(max) = 4.14 nmol · min(-1) · nmol P450(-1)), and CYP2B6 (K(m) = 14.83 μM; V(max) = 5.44 nmol · min(-1) · nmol P450(-1)). P450-mediated detoxification of methyl parathion only occurred to a limited extent with CYP1A2 (K(m) = 16.8 μM; V(max) = 1.38 nmol · min(-1) · nmol P450(-1)) and 3A4 (K(m) = 104 μM; V(max) = 5.15 nmol · min(-1) · nmol P450(-1)), whereas the major enzyme involved in diazinon detoxification was CYP2C19 (K(m) = 5.04 μM; V(max) = 5.58 nmol · min(-1) · nmol P450(-1)). The OP- and P450-specific kinetic values will be helpful for future use in refining human PBPK/PD models of OP exposure.

  20. Evaluation of sublethal biomarkers in Litopenaeus vannamei on foodborne exposure to methyl parathion.

    PubMed

    Comoglio, L; Amin, O; Roque, A; Betancourt-Lozano, M; Anguas, D; Haro, B M

    2005-09-01

    Sublethal effects of foodborne exposure to methyl parathion (0.62 and 1.31 microg methyl parathion*g(-1) dry weight of food) on juveniles of Litopenaeus vannamei using integrated biochemical (acetylcholinesterase (AChE) and ATPases) and physiological (feeding rate (FR), egestion rate (ER), and hepatosomatic index (HI)) biomarkers were evaluated. The HI was significantly higher in controls than in pesticide treatments. The FR was significantly lower in controls than in pesticide treatments while no significant differences were detected in the ER. AChE activity was significantly higher in controls than in pesticide treatments (control = 0.11 +/- 0.02; solvent control = 0.11 +/- 0.03; 0.62 = 0.07 +/- 0.01; 1.31 = 0.08 +/- 0.02 microM*min(-1)*mgprotein(-1)). The total-ATPase activity was significantly lower in controls than in pesticide treatments (control=77.90+/-12.41; solvent control = 83.69 +/- 22.05; 0.62 = 110.03 +/- 22.17; 1.31 = 121.54 +/- 19.84 microM P(i)*h(-1)*mgprotein(-1)). The Mg(2+)-ATPase activity was significantly higher in treatments than in controls (control = 65.14+/-10.76; solvent control = 75.12 +/- 21.10; 0.62 = 100.53 +/- 20.97; 1.31 = 108.94 +/- 17.26 microM P(i)*h(-1)*mgprotein(-1)). Finally, the results obtained for the Na(+)/K(+)-ATPase activity were significantly higher in control and in 1.31 than in solvent control and in 0.62 (control = 14.06+/-2.63; solvent control=7.30 +/- 4.13; 0.62 = 7.60 +/- 3.81; 1.31 = 13.42 +/- 2.88 microM P(i)*h(-1)*mgprotein(-1)). The results in this study showed that pulse exposures to methyl parathion via food could elicit measurable effects on the marine shrimp L. vannamei, indicating that foodborne exposure can be a reliable toxicological procedure and, if combined with pulse exposures, could also simulate more realistic exposure scenarios.

  1. Human Hepatic Cytochrome P450-Specific Metabolism of the Organophosphorus Pesticides Methyl Parathion and Diazinon

    PubMed Central

    Tian, Yuan; Knaak, James B.; Kostyniak, Paul J.; Olson, James R.

    2012-01-01

    Organophosphorus pesticides (OPs) are a public health concern due to their worldwide use and documented human exposures. Phosphorothioate OPs are metabolized by cytochrome P450s (P450s) through either a dearylation reaction to form an inactive metabolite, or through a desulfuration reaction to form an active oxon metabolite, which is a potent cholinesterase inhibitor. This study investigated the rate of desulfuration (activation) and dearylation (detoxification) of methyl parathion and diazinon in human liver microsomes. In addition, recombinant human P450s were used to determine the P450-specific kinetic parameters (Km and Vmax) for each compound for future use in refining human physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models of OP exposure. The primary enzymes involved in bioactivation of methyl parathion were CYP2B6 (Km = 1.25 μM; Vmax = 9.78 nmol · min−1 · nmol P450−1), CYP2C19 (Km = 1.03 μM; Vmax = 4.67 nmol · min−1 · nmol P450−1), and CYP1A2 (Km = 1.96 μM; Vmax = 5.14 nmol · min−1 · nmol P450−1), and the bioactivation of diazinon was mediated primarily by CYP1A1 (Km = 3.05 μM; Vmax = 2.35 nmol · min−1 · nmol P450−1), CYP2C19 (Km = 7.74 μM; Vmax = 4.14 nmol · min−1 · nmol P450−1), and CYP2B6 (Km = 14.83 μM; Vmax = 5.44 nmol · min−1 · nmol P450−1). P450-mediated detoxification of methyl parathion only occurred to a limited extent with CYP1A2 (Km = 16.8 μM; Vmax = 1.38 nmol · min−1 · nmol P450−1) and 3A4 (Km = 104 μM; Vmax = 5.15 nmol · min−1 · nmol P450−1), whereas the major enzyme involved in diazinon detoxification was CYP2C19 (Km = 5.04 μM; Vmax = 5.58 nmol · min−1 · nmol P450−1). The OP- and P450-specific kinetic values will be helpful for future use in refining human PBPK/PD models of OP exposure. PMID:21969518

  2. Studies on combined effects of organophosphates and heavy metals in birds. I. Plasma and brain cholinesterase in Coturnix quail fed methyl mercury and orally dosed with parathion

    USGS Publications Warehouse

    Dieter, M.P.; Ludke, J.L.

    1975-01-01

    We found that mercury potentiated the toxicity and biochemical effects of parathion. Male Coturnix quail (Coturnix coturnix japonica) were fed a sublethal concentration of morsodren (4 ppm as methyl mercury) for 18 weeks. This resulted in an accumulation of 21.0 ppm of mercury in the liver and 8.4 ppm in the carcass. Birds fed clean feed and those fed morsodren-treated feed were orally dosed with 2, 4, 6, 8,and 10 mg/kg parathion, and their 48-h survival times compared. The computed LD50 was 5.86mg/kg in birds not fed morsodren and 4.24 in those fed the heavy metal. When challenged with a sublethal, oral dose of parathion (1.0 mg/kg), morsodren-fed birds exhibited significantly greater inhibition of plasma and brain cholinesterase activity than controls dosed with parathion. Brain cholinesterase activity was inhibited 41% in morsodren-fed birds and 26in clean-fed birds dosed with parathion, which suggested that the increase in parathion toxicity in the presence of morsodren was directly related to the inhibitation of brain cholinesterase.

  3. Detoxification of methyl-parathion pesticide in aqueous solutions by electrochemical oxidation.

    PubMed

    Arapoglou, D; Vlyssides, A; Israilides, C; Zorpas, A; Karlis, P

    2003-03-17

    Commercial methyl-parathion (MeP) was detoxified using an electrochemical method that employed a Ti/Pt anode and stainless steel 304 as cathode. Sodium chloride was added as electrolyte and the mixture was passed through an electrolytic cell for 2 h. Due to the strong oxidizing potential of the produced chemicals, the organic pollutants were wet oxidized to carbon dioxide and water. A number of experiments were run at laboratory scale. Reductions of COD and BOD(5) were both over 80% and the mean energy consumption was 18-8 kWh per kg(-1) COD reduced (COD(r)). The degradation of MeP was more effective when the pH of the brine solution was in the acid range than when it was in the alkaline range. From the results it can be concluded that electrolysis could be used as an oxidation pre-treatment stage for detoxification of toxic wastes with MeP.

  4. Twofold role of calcined hydrotalcites in the degradation of methyl parathion pesticide

    PubMed Central

    Fetter, Geolar; Villafuerte-Castrejon, María Elena; Tejeda-Cruz, Adriana; Bosch, Pedro

    2011-01-01

    Summary Methyl parathion (MP) is a very toxic organophosphate pesticide used as a non-systematic insecticide and acaricide on many corps. As MP and its by-products are highly toxic, they have to be retained to avoid pollution of rivers and lakes. Highly efficient sorbents are hydrotalcites (HTs) (or anionic clays). We have correlated the degradation of an aqueous solution of MP at room temperature, with the basicity of the adsorbing materials. It was found that the metal composition of hydrotalcites determines both the surface electronic properties (basic or acidic) and the sorption capacity. Depending on the basic strength, some calcined hydrotalcites can catalyze the transformation of MP to p-nitrophenol (p-NP) and retain its by-products. Such a process has the advantage of being able to be carried out at room temperature and at the pH of the pesticide solution. PMID:21977419

  5. Twofold role of calcined hydrotalcites in the degradation of methyl parathion pesticide.

    PubMed

    Sampieri, Alvaro; Fetter, Geolar; Villafuerte-Castrejon, María Elena; Tejeda-Cruz, Adriana; Bosch, Pedro

    2011-01-01

    Methyl parathion (MP) is a very toxic organophosphate pesticide used as a non-systematic insecticide and acaricide on many corps. As MP and its by-products are highly toxic, they have to be retained to avoid pollution of rivers and lakes. Highly efficient sorbents are hydrotalcites (HTs) (or anionic clays). We have correlated the degradation of an aqueous solution of MP at room temperature, with the basicity of the adsorbing materials. It was found that the metal composition of hydrotalcites determines both the surface electronic properties (basic or acidic) and the sorption capacity. Depending on the basic strength, some calcined hydrotalcites can catalyze the transformation of MP to p-nitrophenol (p-NP) and retain its by-products. Such a process has the advantage of being able to be carried out at room temperature and at the pH of the pesticide solution.

  6. Reclassification of a parathione-degrading Flavobacterium sp. ATCC 27551 as Sphingobium fuliginis.

    PubMed

    Kawahara, Kazuyoshi; Tanaka, Atsushi; Yoon, Jaewoo; Yokota, Akira

    2010-06-01

    A parathione-degrading bacterium isolated from rice field in the Philippines, Flavobacterium sp. ATCC 27551 (Sethunathan and Yoshida, 1973, Can. J. Microbiol., 19, 873-875), was re-examined chemotaxonomically and phylogenetically. The strain contained 2-hydroxymyristic acid (2-OH 14 : 0), cis-vaccenic acid (18 : 1 omega7c), and palmitic acid (16 : 0) as major cellular fatty acids, two kinds of glycosphingolipids, and ubiquinone-10 as a sole quinone component. The G+C content of genomic DNA of the strain was 65.9 mol%. The phylogenetic analyses of the 16S rRNA gene indicated that the strain was included in the family Sphingomonadaceae, and most closely related to Sphingobium fuliginis (98.0% similarity) and Sphingobium herbicidovorans (97.3%). The strain showed similar physiological characteristics and a moderate value of DNA-DNA relatedness to S. fuliginis. These data suggested it reasonable to conclude that strain ATCC 27551 was identified as S. fuliginis.

  7. Improving the acidic stability of a methyl parathion hydrolase by changing basic residues to acidic residues.

    PubMed

    Huang, Lu; Wang, Ping; Tian, Jian; Jiang, Huachen; Wu, Ningfeng; Yang, Peilong; Yao, Bin; Fan, Yunliu

    2012-06-01

    The acidic stability of a methyl parathion hydrolase (Ochr-MPH) was improved by selectively changing basic amino acids to acidic ones. Mutation sites were selected based on the position-specific amino acid replacement probabilities (more than or equal to 0.2) and the entropy of each site (more than or equal to 0.8). Three mutants (K208E, K277D, and K208E/K277D) were more stable than the wild-type (WT). Their half-lives at pH 5.0 were 64, 68, 65 min, respectively, whereas that of WT was 39 min. The acidic stability of proteins may therefore be improved by changing selected basic amino acid residues to acidic ones.

  8. Differential expression profile of membrane proteins in zebrafish (Danio rerio) brain exposed to methyl parathion.

    PubMed

    Huang, Qing-Yu; Huang, He-Qing

    2011-09-01

    Methyl parathion (MP) is a widely used organophosphorus pesticide, which has been related to a broad spectrum of toxic effects on environmental organisms. The present study investigated the changes in the protein profile of enriched membrane fraction from zebrafish (Danio rerio) brain exposed to three concentrations (0.5, 1 and 2 mg/L) of MP. 2-DE revealed that the abundance of 21 protein spots was significantly changed by MP stress. By matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and database search, 16 protein spots were identified as membrane proteins, among which 8 were down-regulated, while 8 were up-regulated. These proteins are mainly involved in oxidative stress response, signal transduction, metabolism, protein synthesis and degradation, neuroplasticity and regeneration as well as synaptic transmission. These results may aid our understanding of the mechanism of MP-induced neurotoxicity and provide the possibility of the establishment of candidate biomarkers of MP.

  9. Purification and characterization of methyl parathion hydrolase from Burkholderia cepacia capable of degrading organophosphate insecticides.

    PubMed

    Ekkhunnatham, Anirut; Jongsareejit, Boonsri; Yamkunthong, Wanphen; Wichitwechkarn, Jesdawan

    2012-04-01

    Methyl parathion hydrolase (MPH) from a methyl parathion-degrading Burkholderia cepacia indigenous to Thailand was purified to apparent homogeneity by three steps of column chromatography using Resource S, Sephadex G100, and Octyl Sepharose 4FF columns. Its molecular mass was determined to be 35 kDa, and the pI to be 8.5. The recombinant plasmid pGT1, containing the MPH-encoding gene, mpdB, cloned into pGEX-4T-2 was over-expressed in Escherichia coli as GST-MPH fusion protein. The recombinant MPH was purified to homogeneity by a single step, using GSTPrep FF affinity column, with the molecular mass identical to that of the native enzyme. The purified enzyme had the specific activity of about 1,600 unit mg(-1) protein and the yield of about 75%, a 39-fold increase in recovery compared to that of the native enzyme. The optimal temperature and pH were 25°C and 9.0, respectively. The MPH was stable, with its activity unchanged for 48 h at 4°C, and reduced to 50% after 5 h and to 45% after 48 h at 25°C. The enzyme activity remained 80-90% after 8-15 h at pH 6-7. Cd(2+), Co(2+), and Zn(2+) ions at the concentration of 1 mM enhanced the activity; while sodium dodecyl sulfate (SDS), dithiothreitol (DTT) and ethylenediaminetetraacetate (EDTA) reduced it. The enzyme also showed cross reactivity with other insecticides within the organophosphate group, and the kinetic parameters for individual substrates were investigated. Since MPH from B. cepacia has wide potential applications in detoxification and detection of organophosphate compounds, this study provides important basis for its future use.

  10. Optimization of methyl parathion biodegradation and detoxification by cells in suspension or immobilized on tezontle expressing the opd gene.

    PubMed

    Abdel-Razek, Mohamed Abdel-Razek Saleh; Folch-Mallol, Jorge L; Perezgasga-Ciscomani, Lucía; Sánchez-Salinas, Enrique; Castrejón-Godínez, Maria L; Ortiz-Hernández, M Laura

    2013-01-01

    The goal of this study was to optimize methyl parathion (O,O-dimethyl-O-4-p-nitrophenyl phosphorothioate) degradation using a strain of Escherichia coli DH5α expressing the opd gene. Our results indicate that this strain had lower enzymatic activity compared to the Flavobacterium sp. ATCC 27551 strain from which the opd gene was derived. Both strains were assessed for their ability to degrade methyl parathion (MP) in a mineral salt medium with or without the addition of glucose either as suspended cells or immobilized on tezontle, a volcanic rock. MP was degraded by both strains with similar efficiencies, but immobilized cells degraded MP more efficiently than cells in suspension. However, the viability of E. coli cells was much higher than that of the Flavobacterium sp. We confirmed the decrease in toxicity from the treated effluents through acetylcholinesterase activity tests, indicating the potential of this method for the treatment of solutions containing MP.

  11. Superoxide dismutase, catalase and acetylcholinesterase: biomarkers for the joint effects of cadmium, zinc and methyl parathion contamination in water.

    PubMed

    Ling, XuePing; Zhang, YiHeng; Lu, YingHua; Huang, HeQing

    2011-10-01

    Heavy metals are known to reduce the activities of antioxidant enzymes (e.g. superoxide dismutase, catalase), while organophosphorous insecticides are known to inhibit the activity of the enzyme acetylcholinesterase. In this study, the activities of these three enzymes in zebrafish (Danio rerio) tissues were assessed to evaluate the consequences heavy metal and organophosphate contamination in aquatic systems. When the fish were contacted with water containing a single pollutant, superoxide dismutase activity was affected by the presence of Cd but not by methyl parathion or Zn. However, catalase and acetylcholinesterase activities were sensitive to all three pollutants. The combined treatment showed that the three enzymes could be chosen as biomarkers of joint pollution by both metals and organophosphate. Toxicity tests showed an antagonism interaction between methyl parathion and Cd or Zn, and the change of enzyme activities at 96 hours was in accordance with that.

  12. Effective antibodies immobilization and functionalized nanoparticles in a quartz-crystal microbalance-based immunosensor for the detection of parathion

    PubMed Central

    Della Ventura, Bartolomeo; Iannaccone, Marco; Funari, Riccardo; Pica Ciamarra, Massimo; Altucci, Carlo; Capparelli, Rosanna; Roperto, Sante; Velotta, Raffaele

    2017-01-01

    Background Biosensor-based detection provides a rapid and low-cost alternative to conventional analytical methods for revealing the presence of the contaminants in water as well as solid matrices. Although important to be detected, small analytes (few hundreds of Daltons) are an issue in biosensing since the signal they induce in the transducer, and specifically in a Quartz-Crystal Microbalance, is undetectable. A pesticide like parathion (M = 292 Da) is a typical example of contaminant for which a signal amplification procedure is desirable. Methods/Findings The ballasting of the analyte by gold nanoparticles has been already applied to heavy target as proteins or bacteria to improve the limit of detection. In this paper, we extend the application of such a method to small analytes by showing that once the working surface of a Quartz-Crystal Microbalance (QCM) has been properly functionalized, a limit of detection lower than 1 ppb is reached for parathion. The effective surface functionalization is achieved by immobilizing antibodies upright oriented on the QCM gold surface by a simple photochemical technique (Photonic Immobilization Technique, PIT) based on the UV irradiation of the antibodies, whereas a simple protocol provided by the manufacturer is applied to functionalize the gold nanoparticles. Thus, in a non-competitive approach, the small analyte is made detectable by weighing it down through a “sandwich protocol” with a second antibody tethered to heavy gold nanoparticles. The immunosensor has been proved to be effective against the parathion while showing no cross reaction when a mixture of compounds very similar to parathion is analyzed. Conclusion/Significance The immunosensor described in this paper can be easily applied to any small molecule for which polyclonal antibodies are available since both the functionalization procedure of the QCM probe surface and gold nanoparticle can be applied to any IgG, thereby making our device of general

  13. Identification of a plasmid-borne parathion hydrolase gene from Flavobacterium sp. by southern hybridization with opd from Pseudomonas diminuta.

    PubMed

    Mulbry, W W; Karns, J S; Kearney, P C; Nelson, J O; McDaniel, C S; Wild, J R

    1986-05-01

    Parathion hydrolases have been previously described for an American isolate of Pseudomonas diminuta and a Philippine isolate of Flavobacterium sp. (ATCC 27551). The gene which encodes the broad-spectrum organophosphate phosphotriesterase in P. diminuta has been shown by other investigators to be located on a 66-kilobase (kb) plasmid. The intact gene (opd, organophosphate-degrading gene) from this degradative plasmid was cloned into M13mp10 and found to express parathion hydrolase under control of the lac promoter in Escherichia coli. In Flavobacterium sp. strain ATCC 27551, a 43-kb plasmid was associated with the production of parathion hydrolase by curing experiments. The M13mp10-cloned fragment of the opd gene from P. diminuta was used to identify a homologous genetic region from Flavobacterium sp. strain ATCC 27551. Southern hybridization experiments demonstrated that a genetic region from the 43-kb Flavobacterium sp. plasmid possessed significant homology to the opd sequence. Similar hybridization did not occur with three other native Flavobacterium sp. plasmids (approximately 23, 27, and 51 kb) present within this strain or with genomic DNA from cured strains. Restriction mapping of various recombinant DNA molecules containing subcloned fragments of both opd plasmids revealed that the restriction maps of the two opd regions were similar, if not identical, for all restriction endonucleases tested thus far. In contrast, the restriction maps of the cloned plasmid sequences outside the opd regions were not similar. Thus, it appears that the two discrete bacterial plasmids from parathion-hydrolyzing soil bacteria possess a common but limited region of sequence homology within potentially nonhomologous plasmid structures.

  14. Identification of a plasmid-borne parathion hydrolase gene from Flavobacterium sp. by southern hybridization with opd from Pseudomonas diminuta.

    PubMed Central

    Mulbry, W W; Karns, J S; Kearney, P C; Nelson, J O; McDaniel, C S; Wild, J R

    1986-01-01

    Parathion hydrolases have been previously described for an American isolate of Pseudomonas diminuta and a Philippine isolate of Flavobacterium sp. (ATCC 27551). The gene which encodes the broad-spectrum organophosphate phosphotriesterase in P. diminuta has been shown by other investigators to be located on a 66-kilobase (kb) plasmid. The intact gene (opd, organophosphate-degrading gene) from this degradative plasmid was cloned into M13mp10 and found to express parathion hydrolase under control of the lac promoter in Escherichia coli. In Flavobacterium sp. strain ATCC 27551, a 43-kb plasmid was associated with the production of parathion hydrolase by curing experiments. The M13mp10-cloned fragment of the opd gene from P. diminuta was used to identify a homologous genetic region from Flavobacterium sp. strain ATCC 27551. Southern hybridization experiments demonstrated that a genetic region from the 43-kb Flavobacterium sp. plasmid possessed significant homology to the opd sequence. Similar hybridization did not occur with three other native Flavobacterium sp. plasmids (approximately 23, 27, and 51 kb) present within this strain or with genomic DNA from cured strains. Restriction mapping of various recombinant DNA molecules containing subcloned fragments of both opd plasmids revealed that the restriction maps of the two opd regions were similar, if not identical, for all restriction endonucleases tested thus far. In contrast, the restriction maps of the cloned plasmid sequences outside the opd regions were not similar. Thus, it appears that the two discrete bacterial plasmids from parathion-hydrolyzing soil bacteria possess a common but limited region of sequence homology within potentially nonhomologous plasmid structures. Images PMID:3015022

  15. Metabolism of carbaryl, chloropyrifos, DDT, and parathion in the European corn borer: effects of microsporidiosis on toxicity and detoxication

    SciTech Connect

    Tetreault, G.E.

    1985-01-01

    An investigation was conducted to examine the effects of microsporidiosis on an insect's response to insecticide intoxication. Healthy European corn borer, Ostrinia nubilalis, larvae and those heavily infected with the microsporidian pathogen, Nosema pyrausta, were bioassayed with ten insecticides. The compounds used were carbaryl, carbofuran, chlorophrifos, DDT, diazinon, fonofos, methomyl, parathion, permethrin, and terbufos. Third instar larvae were used for topical bioassays. The compounds carbaryl, carbofuran, chlorophrifos, methomyl and terbufos were found to be significantly more toxic to diseased insects than healthy insects at the 0.05 probability level. To examine the effect of Nosema pyrausta infection on the European corn borer's ability to detoxify insecticides, /sup 14/C ring-labeled carbaryl, chlorophrifos, DDT, and parathion were topically applied to fourth instar larvae. Qualitative differences between healthy and diseased insects were found in the metabolic pathways of carbaryl, DDT, and parathion. The degradative fate of chlorophrifos was the same in both groups. Quantitatively, each insecticide penetrated diseased larvae faster. This resulted in larger amounts of the applied dose of parent compound and metabolites being found in the feces from diseased insects. Conversely, healthy insects had more of these materials present in the body and associated with the cuticle.

  16. The interaction of the phosphorothioate insecticides chlorpyrifos and parathion and their oxygen analogues with bovine serum albumin.

    PubMed

    Sultatos, L G; Basker, K M; Shao, M; Murphy, S D

    1984-07-01

    The distribution and subsequent toxicity of hazardous chemicals can be influenced by their interactions with plasma proteins. In the present study reversible binding of the phosphorothioate insecticides chlorpyrifos and parathion to fatty acid-free bovine serum albumin (BSA) was examined using the technique of equilibrium dialysis. Computer analyses of the binding data revealed that chlorpyrifos and parathion each bound reversibly to a single class of binding sites on BSA, with apparent KD values of 3.4 +/- 0.1 and 11.1 +/- 0.3 microM, respectively. Additionally, the maximal number of binding sites for each insecticide per molecule of BSA was one. Displacement studies using both chlorpyrifos and parathion indicated that each was a competitive inhibitor of the other's binding, suggesting that they were bound to the same site. Incubation of chlorpyrifos oxon or paraoxon with a 1% solution of BSA resulted in limited, EDTA-insensitive formation of 3,5,6-trichloro-2-pyridinol or p-nitrophenol, respectively. Pretreatment of BSA with 5 mM paraoxon, chlorpyrifos oxon, or 1 mM diisopropylfluorophosphate did not alter this activity, suggesting that these reactions resulted from an esterase-like capacity of BSA, and not from phosphorylation of BSA by these oxons.

  17. Acute and chronic effects of parathion and 2,4 D on the oxygen consumption of Chasmagnathus granulata (Decapoda, Brachyura).

    PubMed

    Rodríguez, E M; Monserrat, J M

    1991-01-01

    The effect of two pesticides widely used in Argentina on the oxygen consumption of the estuarine crab Chasmagnathus granulata was studied. Constant pressure respirometers were employed to estimate the rate of oxygen consumption per weight unit of animals treated previously with each pesticide, both acute (96 h) and chronically (15 and 30 days). Crabs exposed to parathion -an organophosphorate insecticide that causes the inhibition of acetylcholinesterase- show an increase of oxygen consumption at 0.5 ppm under acute exposure, and at 10 ppb under a chronic one. On the other hand, crabs exposed to 2,4 D (an herbicide) did not show changes in their consumption after an acute exposure, but those exposed chronically did show an increase at low concentration (5 ppm) followed by a relative decrease at the highest concentration (50 ppm). The results obtained for parathion are in accordance with the abnormal cholinergic excitation that it may exert on crustacean nervous system. The effect of 2,4 D was consistent with its uncoupler action at respiratory chain level, at low concentrations, while a possible Krebs cycle enzymes inhibition might be occurring at higher concentrations of that pesticide, as in other crustacean species. The faster action of parathion, respect to 2,4 D, is explained by its neurotoxic nature.

  18. An approach for the quantitative consideration of genetic polymorphism data in chemical risk assessment: examples with warfarin and parathion.

    PubMed

    Gentry, P Robinan; Hack, C Eric; Haber, Lynne; Maier, Andrew; Clewell, Harvey J

    2002-11-01

    In recent years, a great deal of research has been conducted to identify genetic polymorphisms. One focus has been to characterize variability in metabolic enzyme systems that could impact internal doses of pharmaceuticals or environmental pollutants. Methods are needed for using this metabolic information to estimate the resulting variability in tissue doses associated with chemical exposure. We demonstrate here the use of physiologically based pharmacokinetic (PBPK) modeling in combination with Monte Carlo analysis to incorporate information on polymorphisms into the analysis of toxicokinetic variability. Warfarin and parathion were used as case studies to demonstrate this approach. Our results suggest that polymorphisms in the PON1 gene, that give rise to allelic variants of paraoxonase, which is involved in the metabolism of paraoxon (a metabolite of parathion), make only a minor contribution to the overall variability in paraoxon tissue dose, while polymorphisms in the CYP2C9 gene, which gives rise to allelic variants of the major metabolic enzyme for warfarin, account for a significant portion of the overall variability in (S)-warfarin tissue dose. These analyses were used to estimate chemical-specific adjustment factors (CSAFs) for the human variability in toxicokinetics for both parathion and warfarin. Implications of alternatives in the calculation of CSAFs are explored. Key decision points for applying the PBPK-Monte Carlo approach to evaluate toxicokinetic variability for other chemicals are also discussed.

  19. Covalent coupling of organophosphorus hydrolase loaded quantum dots to carbon nanotube/Au nanocomposite for enhanced detection of methyl parathion.

    PubMed

    Du, Dan; Chen, Wenjuan; Zhang, Weiying; Liu, Deli; Li, Haibing; Lin, Yuehe

    2010-02-15

    An amperometric biosensor for highly selective and sensitive determination of methyl parathion (MP) was developed based on dual-signal amplification: (1) a large amount of introduced enzyme on the electrode surface and (2) synergistic effects of nanoparticles towards enzymatic catalysis. The fabrication process includes (1) electrochemical deposition of gold nanoparticles by a multi-potential step technique at multiwalled carbon nanotube (MWCNT) film pre-cast on a glassy carbon electrode and (2) immobilization of methyl parathion degrading enzyme (MPDE) onto a modified electrode through CdTe quantum dots (CdTe QDs) covalent attachment. The introduced MWCNT and gold nanoparticles significantly increased the surface area and exhibited synergistic effects towards enzymatic catalysis. CdTe QDs are further used as carriers to load a large amount of enzyme. As a result of these two important enhancement factors, the proposed biosensor exhibited extremely sensitive, perfectly selective, and rapid response to methyl parathion in the absence of a mediator. The detection limit was 1.0 ng/mL. Moreover, since MPDE hydrolyzes pesticides containing the P-S bond, it showed high selectivity for detecting MP and many interfering compounds, such as carbamate pesticides. Other organophosphorous pesticides and oxygen-containing inorganic ions (SO(4)(2-), NO(3)(-)) did not interfere with the determination. The proposed MPDE biosensor presents good reproducibility and stability, and the MPDE is not poisoned by organophosphate pesticides. Unlike cholinesterase-based biosensor, the MPDE biosensor can be potentially reused and is suitable for continuous monitoring.

  20. An optical microbial biosensor for detection of methyl parathion using Sphingomonas sp. immobilized on microplate as a reusable biocomponent.

    PubMed

    Kumar, Jitendra; D'Souza, S F

    2010-12-15

    Organophosphorus pesticides such as methyl parathion have been widely used in the field of agriculture for insect pest control. These pesticides and their degradation products cause environmental pollution and ecological problem. With a view to monitor these pesticides biosensors are being developed. A bacterium Sphingomonas sp. from field soil has been isolated and identified in our laboratory that hydrolyzes the methyl parathion upto a chromophoric product, p-nitrophenol (PNP). PNP can be detected by electrochemical and colorimetric methods, which can be exploited to develop a biosensor for detection of the organophosphate pesticide. Whole cells of Sphingomonas bacteria were immobilized directly onto the surface of the wells of polystyrene microplates (96 wells) using glutaraldehyde as the cross-linker. SEM study confirmed the immobilization of Sphingomonas sp. Immobilized bacterial microplate was associated directly with the optical transducer, microplate reader. The microplate-based biosensor is having advantages as it has 96 reaction vessels and therefore it provides a convenient system for detecting multiple numbers of samples in a single platform. Detection range of the biosensor from the linear range was determined to be 4-80 μM methyl parathion. Cells-immobilized microplates were having reusability upto 75 reactions. Present study reports an innovative concept where the microplate can be used as immobilizing support for development of reusable microbial biocomponent.

  1. A simple and sensitive fluorescent sensor for methyl parathion based on L-tyrosine methyl ester functionalized carbon dots.

    PubMed

    Hou, Juying; Dong, Jing; Zhu, Haishuang; Teng, Xue; Ai, Shiyun; Mang, Minglin

    2015-06-15

    In this paper, a simple and sensitive fluorescent sensor for methyl parathion is developed based on L-tyrosine methyl ester functionalized carbon dots (Tyr-CDs) and tyrosinase system. The carbon dots are obtained by simple hydrothermal reaction using citric acid as carbon resource and L-tyrosine methyl ester as modification reagent. The carbon dots are characterized by transmission electron microscope, high resolution transmission electron microscopy, X-ray diffraction spectrum, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The carbon dots show strong and stable photoluminescence with a quantum yield of 3.8%. Tyrosinase can catalyze the oxidation of tyrosine methyl ester on the surface of carbon dots to corresponding quinone products, which can quench the fluorescence of carbon dots. When organophosphorus pesticides (OPs) are introduced in system, they can decrease the enzyme activity, thus decrease the fluorescence quenching rate. Methyl parathion, as a model of OPs, was detected. Experimental results show that the enzyme inhibition rate is proportional to the logarithm of the methyl parathion concentration in the range 1.0×10(-10)-1.0×10(-4) M with the detection limit (S/N=3) of 4.8×10(-11) M. This determination method shows a low detection limit, wide linear range, good selectivity and high reproducibility. This sensing system has been successfully used for the analysis of cabbage, milk and fruit juice samples.

  2. Effects of Exposure to Methyl Parathion on Egg Hatchability and Eggshell Chemical Composition in Podocnemis expansa (Testudines, Podocnemididae).

    PubMed

    Valdes, Sady Alexis Chavauty; Vieira, Lucélia Gonçalves; Ferreira, Caio Henrique; dos Santos Mendonça, Juliana; Ribeiro, Priscilla Rosa Queiroz; de Abreu Fernandes, Evandro; Santos, André Luiz Quagliatto

    2015-04-01

    Eggshell evaluation may serve as an indicator of the effect of substances released in the environment, which may change eggshell shape, size, structure, and/or chemical composition. Additionally, exposure may interfere with hatching rates in contaminated eggs. The objective of this study was to better understand how exposure to the insecticide methyl parathion interferes with chemical changes in eggshells of Podocnemis expansa throughout their artificial incubation, as well as with egg hatchability. A total of 343 P. expansa eggs were collected in a natural reproduction area for the species. These eggs were transferred to and artificially incubated in the Wild Animal Teaching and Research Laboratory at Universidade Federal de Uberlândia. On the first day of artificial incubation, 0, 35, 350, and 3500 ppb of methyl parathion were incorporated to the substrate. Eggs were collected every three days for chemical analysis of eggshells. Hatchability was evaluated as the number of hatchlings in each treatment, for the eggs that were not used in the chemical analysis. Student's T-test was used for data on eggshell chemical composition, and the Binomial Test for Two Proportions was used in the hatchability analysis, at a 5% significance level. It was observed that the incorporation of methyl parathion to the substrate on the first day of artificial incubation of P. expansa eggs reduced the levels of total fat in the shells throughout their incubation, besides reducing egg hatchability.

  3. Effect of ionising radiation on polyphenolic content and antioxidant potential of parathion-treated sage (Salvia officinalis) leaves.

    PubMed

    Ben Salem, Issam; Fekih, Sana; Sghaier, Haitham; Bousselmi, Mehrez; Saidi, Mouldi; Landoulsi, Ahmed; Fattouch, Sami

    2013-11-15

    The γ-irradiation effects on polyphenolic content and antioxidant capacity of parathion-pretreated leaves of Salvia officinalis plant were investigated. The analysis of phenolic extracts of sage without parathion showed that irradiation decreased polyphenolic content significantly (p<0.05) by 30% and 45% at 2 and 4kGy, respectively, compared to non-irradiated samples. The same trend was observed for the Trolox equivalent antioxidant capacity (TEAC), as assessed by the anionic DPPH and cationic ABTS radical-scavenging assays. The antioxidant potential decreased significantly (p<0.01) at 2 and 4kGy, by 11-20% and 40-44%, respectively. The results obtained with a pure chlorogenic acid solution confirmed the degradation of phenols; however, its TEAC was significantly (p<0.01) increased following irradiation. Degradation products of parathion formed by irradiation seem to protect against a decline of antioxidant capacity and reduce polyphenolic loss. Ionising radiation was found to be useful in breaking down pesticide residues without inducing significant losses in polyphenols.

  4. Comparative effects of parathion and chlorpyrifos on extracellular endocannabinoid levels in rat hippocampus: Influence on cholinergic toxicity

    SciTech Connect

    Liu, Jing; Parsons, Loren; Pope, Carey

    2013-11-01

    Parathion (PS) and chlorpyrifos (CPF) are organophosphorus insecticides (OPs) that elicit acute toxicity by inhibiting acetylcholinesterase (AChE). Endocannabinoids (eCBs, N-arachidonoylethanolamine, AEA; 2-arachidonoylglycerol, 2AG) can modulate neurotransmission by inhibiting neurotransmitter release. We proposed that differential inhibition of eCB-degrading enzymes (fatty acid amide hydrolase, FAAH, and monoacylglycerol lipase, MAGL) by PS and CPF leads to differences in extracellular eCB levels and toxicity. Microdialysis cannulae were implanted into hippocampus of adult male rats followed by treatment with vehicle (peanut oil, 2 ml/kg, sc), PS (27 mg/kg) or CPF (280 mg/kg) 6–7 days later. Signs of toxicity, AChE, FAAH and MAGL inhibition, and extracellular levels of AEA and 2AG were measured 2 and 4 days later. Signs were noted in PS-treated rats but not in controls or CPF-treated rats. Cholinesterase inhibition was extensive in hippocampus with PS (89–90%) and CPF (78–83%) exposure. FAAH activity was also markedly reduced (88–91%) by both OPs at both time-points. MAGL was inhibited by both OPs but to a lesser degree (35–50%). Increases in extracellular AEA levels were noted after either PS (about 2-fold) or CPF (about 3-fold) while lesser treatment-related 2-AG changes were noted. The cannabinoid CB1 receptor antagonist/inverse agonist AM251 (3 mg/kg, ip) had no influence on functional signs after CPF but markedly decreased toxicity in PS-treated rats. The results suggest that extracellular eCBs levels can be markedly elevated by both PS and CPF. CB1-mediated signaling appears to play a role in the acute toxicity of PS but the role of eCBs in CPF toxicity remains unclear. - Highlights: • Chlorpyrifos and parathion both extensively inhibited hippocampal cholinesterase. • Functional signs were only noted with parathion. • Chlorpyrifos and parathion increased hippocampal extracellular anandamide levels. • 2-Arachidonoylglycerol levels were

  5. Activation and degradation of the phosphorothionate insecticides parathion and EPN by rat brain.

    PubMed

    Forsyth, C S; Chambers, J E

    1989-05-15

    Cytochrome P-450-dependent monooxygenases are known to activate phosphorothionate insecticides to their oxon (phosphate) analogs by oxidative desulfuration. These activations produced potent anticholinesterases, decreasing the I50 values to rat brain acetylcholinesterase almost 1000-fold (from the 10(-5) M range to the 10(-8) M range). Since the usual cause of death in mammals from organophosphorus insecticide poisoning is respiratory failure resulting, in part, from a failure of the respiratory control center of the brain, we investigated the ability of rat brain to activate and subsequently degrade two phosphorothionate insecticides, parathion (diethyl 4-nitrophenyl phosphorothioate) and EPN (ethyl 4-nitrophenyl phenylphosphonothioate). Microsomes from specific regions (cerebral cortex, corpus striatum, cerebellum, and medulla/pons) of the brains of male and female rats and from liver were incubated with the phosphorothionate and an NADPH-generating system. Oxon production was quantified indirectly by the amount of inhibition resulting in an exogenous source of acetylcholinesterase added to the incubation mixture as an oxon trap. The microsomal activation specific activity was low for brain when compared to liver [0.23 to 0.44 and 5.1 to 12.0 nmol.min-1.(g tissue)-1 respectively]. The mitochondrial fraction of the brain possessed an activation activity for parathion similar to that of microsomes [about 0.35 nmol.min-1.(g tissue)-1 for each fraction], but mitochondrial activity was slightly greater than microsomal activity for EPN activation [0.53 to 0.58 and 0.23 to 0.47 nmole.min-1.(g tissue)-1]. Whole homogenates were tested for their ability to degrade paraoxon and EPN-oxon (ethyl 4-nitrophenyl phenylphosphonate), quantitated by 4-nitrophenol production. Specific activity for oxon degradation in liver was greater than that in brain [31 to 74 and 1.1 to 10.7 nmole.min-1.(g tissue)-1 respectively]. Overall, the brain and liver had about 1.5- to 12-fold higher

  6. Comparison of biosorption and phytoremediation of cadmium and methyl parathion, a case-study with live Lemna gibba and Lemna gibba powder.

    PubMed

    Halaimi, F Z; Kellali, Y; Couderchet, M; Semsari, S

    2014-07-01

    Heavy metals and pesticides can be adsorbed by several biomasses such as living or non-living aquatic plants. In this study adsorption properties of live Lemna gibba and Lemna gibba powder were investigated with regard to cadmium and methyl parathion (MP). Toxicity data (IC50) on live L. gibba indicated that the period of four days was adequate for phytoremediation. Initial adsorption studies showed that both adsorbents were capable of removing cadmium and methyl parathion. Cadmium and methyl parathion adsorption onto L. gibba powder was fast and equilibrium was attained within 120min. The adsorption data could be well interpreted by the Freundlich model. The KF were: 7.8963 (Cd(2+)/ live Lemna); 0.7300 (MP/live Lemna); 11.5813 (Cd(2+)/Lemna powder); 1.1852 (MP/Lemna powder) indicating that Cd(2+) was more efficiently removed by both biosorbents than MP. Adsorption kinetics for cadmium and methyl parathion in both systems and rate constants were determined for each contaminant. It was found that the overall adsorption process was best described by pseudo-second-order kinetics. Boyd model and external mass-transfer expression were tested. It was concluded that cadmium and methyl parathion sorption onto Lemna powder is governed by film diffusion.

  7. Hydrolysis mechanism of methyl parathion evidenced by Q-Exactive mass spectrometry.

    PubMed

    Liu, Yuan; Zhang, Caixiang; Liao, Xiaoping; Luo, Yinwen; Wu, Sisi; Wang, Jianwei

    2015-12-01

    Organophosphorus pesticides (OPPs), a kind of widely used pesticides, are currently attracting great attention due to their adverse effects on human central nervous systems, particularly in children. Although the hydrolysis behavior of OPPs has been studied well, its hydrolysis mechanism remained controversial, especially at various pH conditions, partly due to their relatively complex structures and abundant moieties that were prone to be attacked by nucleophiles. The Q-Exactive mass spectrometer, part of those hybrid high-resolution mass spectrometers (HRMS), was used to determine hydrolysis products of methyl parathion (MP), a kind of OPPs in situ buffer aqueous solution with pH ranging from 1 to 13 in this study. Most of the complex hydrolysis products of MP were identified due to the high sensitivity and accuracy of HRMS. The results demonstrated that the hydrolysis rate and pathway of MP were strong pH dependent. With the increase of pH, the hydrolysis rate of MP increased, and two different reaction mechanisms were identified: SN (2)@P pathway dominated the hydrolysis process at high pH (e.g., pH ≥ 11) while SN (2)@C was the main behavior at low pH (e.g., pH ≤ 9). This study helps understand the hydrolysis mechanism of OPPs at various pH and extends the use of Q-Exactive mass spectrometry in identifying organic pollutants and their degradation products in environmental matrices.

  8. Probing the mechanisms for the selectivity and promiscuity of methyl parathion hydrolase

    PubMed Central

    Purg, Miha; Pabis, Anna; Baier, Florian; Tokuriki, Nobuhiko; Jackson, Colin

    2016-01-01

    Diverse organophosphate hydrolases have convergently evolved the ability to hydrolyse man-made organophosphates. Thus, these enzymes are attractive model systems for studying the factors shaping enzyme functional evolution. Methyl parathion hydrolase (MPH) is an enzyme from the metallo-β-lactamase superfamily, which hydrolyses a wide range of organophosphate, aryl ester and lactone substrates. In addition, MPH demonstrates metal-ion-dependent selectivity patterns. The origins of this remain unclear, but are linked to open questions about the more general role of metal ions in functional evolution and divergence within enzyme superfamilies. Here, we present detailed mechanistic studies of the paraoxonase and arylesterase activities of MPH complexed with five different transition metal ions, and demonstrate that the hydrolysis reactions proceed via similar pathways and transition states. However, while it is possible to discern a clear structural origin for the selectivity between different substrates, the selectivity between different metal ions appears to lie instead in the distinct electrostatic properties of the metal ions themselves, which causes subtle changes in transition state geometries and metal–metal distances at the transition state rather than significant structural changes in the active site. While subtle, these differences can be significant for shaping the metal-ion-dependent activity patterns observed for this enzyme. This article is part of the themed issue ‘Multiscale modelling at the physics–chemistry–biology interface’. PMID:27698033

  9. Alterations of protein profile in zebrafish liver cells exposed to methyl parathion: a membrane proteomics approach.

    PubMed

    Huang, Qingyu; Huang, He-Qing

    2012-03-01

    Methyl parathion (MP) is an extensively used organophosphorus pesticide, which has been associated with a wide spectrum of toxic effects on environmental organisms. The aim of this study is to investigate the alterations of membrane protein profiles in zebrafish liver (ZFL) cell line exposed to MP for 24 h using proteomic approaches. Two-dimensional gel electrophoresis revealed a total of 13 protein spots, whose expression levels were significantly altered by MP. These differential proteins were subjected to matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry analysis, and nine proteins were identified to be membrane proteins, among which seven were up-regulated, while two were down-regulated. In addition, the mRNA levels corresponding to these differential membrane proteins were further analyzed by quantitative real-time PCR. And the differential expression of arginase-2 was specially validated via Western blotting. Regarding the physiological functions, these proteins are involved in molecular chaperon, cytoskeleton system, cell metabolism, signal transduction, transport and hormone receptor respectively, suggesting the complexity of MP-mediated toxicity to ZFL cell. These data could provide useful insights for better understanding the hepatotoxic mechanisms of MP and develop novel protein biomarkers for effectively monitoring MP contamination level in aquatic environment.

  10. Direct synthesis of graphene-chitosan composite and its application as an enzymeless methyl parathion sensor.

    PubMed

    Yang, Shanli; Luo, Shenglian; Liu, Chengbin; Wei, Wanzhi

    2012-08-01

    This paper proposed a direct electrodeposition approach to synthesis of graphene-chitosan (GR-CS) composite onto glassy carbon electrode (GCE) under controlled potential. This direct electrodeposition approach for the construction of GR-based hybrid was environmentally friendly, which would not involve the chemical reduction of graphene oxide (GO) and therefore result in no further contamination. The whole procedure was simply and cost only several minutes. Moreover, Combining the advantages of GR (large surface-to-volume ratio and high conductivity) and CS (good biocompatibility and adsorption), the GR-CS composite could be highly efficient to capture OPs and used as solid phase extraction (SPE). The GR-CS/GCE was used to detect organophosphate pesticides (OPs), using methyl parathion (MP) as a model analyte. The significantly redox response of MP on the GR-CS/GCE was proved. The linear range was wide from 4.0 ng mL(-1) to 400 ng mL(-1), and a low detection limit of 0.8 ng mL(-1) for MP was achieved. Moreover, the proposed sensor exhibited high reproducibility, long-time storage stability and satisfactory anti-interference ability. The proposed GR-CS/GCE opens new opportunity for green, fast, simple, and sensitive analysis of OP compounds.

  11. Protective effect of sodium aescinate on lung injury induced by methyl parathion.

    PubMed

    Du, Yuan; Wang, Tian; Jiang, Na; Ren, Ru-Tong; Zhao, De-Lu; Li, Chong; Fu, Feng-Hua

    2011-10-01

    Methyl parathion (MP) is a high venenosus insecticide. It has been used in pest control of agriculture for several years. The present study is performed to investigate the protective effect of sodium aescinate (SA) on lung injury induced by MP. Forty male Sprague-Dawley rats are randomly divided into five groups, with 8 animals in each group: control group, MP administration group, MP plus SA at doses of 0.45 mg/kg, 0.9 mg/kg and 1.8 mg/kg groups. Acetylcholinesterase (AChE) activity and nitric oxide (NO) level in plasma, myeloperoxidase (MPO) activity, NO level, and antioxidative parameters in lung tissue are assayed. Histopathological examination of lung is also performed. The results show that SA has no effect on AChE. Treatment with SA decreases the activity of MPO in lung and the level of NO in plasma and lung. The level of malondialdehyde in lung is decreased after SA treatments. SA increases the activities of superoxide dismutase, glutathione peroxidase and the content of glutathione in lung. SA administration also ameliorates lung injury induced by MP. The findings indicate that SA could protect lung injury induced by MP and the mechanism of action is related to the anti-inflammatory and anti-oxidative effect of SA.

  12. Fluorescent transgenic zebrafish as a biosensor for growth-related effects of methyl parathion.

    PubMed

    Almeida, Daniela Volcan; Vaz, Bernardo; Azevedo Figueiredo, Márcio; Junior, Antonio Sergio Varela; Marins, Luis Fernando

    2014-07-01

    Transgenic fish models are potential alternative subjects in toxicological studies, since they can provide in vivo information on the deleterious effects of different substances. Here, we used a transgenic zebrafish (Danio rerio) lineage, which expresses a destabilized fluorescent protein (DsRED) driven by the myosin light chain promoter (Mylz2), in order to propose a new research tool for environmental biomonitoring. For validating the MYO-RED lineage, we exposed fish to the organophosphorated pesticide methyl parathion (MP). The effect of MP on fish growth was assessed by evaluating weight, length, condition factor and muscle fiber diameter. All factors suffered reduction at both tested concentrations (0.13μM and 13μM of MP). Similarly, fluorescence intensity decreased in a concentration-dependent manner, suggesting muscle protein catabolism. However, DsRED gene expression lowered only at the higher MP concentration. Results indicate that the MYO-RED transgenic zebrafish is an interesting model for detecting the growth-related effects of pollutants. Destabilized proteins such as reporter genes are apparently sensitive biomarkers, since effects were observed even at the lower, environmentally acceptable concentration. Therefore, this transgenic fish is a promising candidate model for sensitive, fast, and easy environmental monitoring.

  13. Selection of a whole-cell biocatalyst for methyl parathion biodegradation.

    PubMed

    Yang, Jijian; Liu, Ruihua; Jiang, Hong; Yang, Yao; Qiao, Chuanling

    2012-09-01

    Whole-cell biocatalyst has the potential to become a cost-effective alternative to conventional enzyme methods for solving ecological and energy issues. However, cytosolic-expressing biocatalyst systems are critically disadvantaged due to the low permeability of the cell membrane. To overcome substrate transport barrier, periplasmic secretion and surface display biocatalysts were developed by expressing signal peptides or anchor proteins in Escherichia coli. In this work, six carriers were compared in regard to whole-cell activity of methyl parathion hydrolase (MPH). Our results indicate that the surface display systems yielded one to three times whole-cell activity than the periplasmic secretion systems. Although periplasmic secretion systems showed generally more stable than surface display systems, surface display appeared more suitable for whole-cell biocatalyst. It should note that the applicability of the DsbA/PhoA/AIDA-I leader to MPH expression is shown here for the first time. In addition, the result provided a useful reference for other whole-cell biocatalyst selection.

  14. Interfacial interaction between methyl parathion-degrading bacteria and minerals is important in biodegradation.

    PubMed

    Zhao, Gang; Huang, Qiaoyun; Rong, Xingmin; Cai, Peng; Liang, Wei; Dai, Ke

    2014-02-01

    In the present study, the influence of kaolinite and goethite on microbial degradation of methyl parathion was investigated. We observed that the biodegradation process was improved by kaolinite and depressed by goethite. Calorimetric data further showed that the metabolic activities of degrading cells (Pseudomonas putida) were enhanced by the presence of kaolinite and depressed by the presence of goethite. A semipermeable membrane experiment was performed and results supported the above observations: the promotive effect of kaolinite and the inhibition of goethite for microbial degradation was not found when the bacteria was enclosed by semipermeable membrane and had no direct contact with these minerals, suggesting the important function of the contact of cellular surfaces with mineral particles. The relative larger particles of kaolinite were loosely attached to the bacteria. This attachment made the cells easy to use the sorbed substrate and then stimulated biodegradation. For goethite, small particles were tightly bound to bacterial cells and limited the acquisition of substrate and nutrients, thereby inhibiting biodegradation. These results indicated that interfacial interaction between bacterial cells and minerals significantly affected the biodegradation of pesticides.

  15. Determination of methyl parathion in water and its removal on zirconia using optical enzyme assay.

    PubMed

    Deshpande, Kanchanmala; Mishra, Rupesh K; Bhand, Sunil

    2011-07-01

    A simple, miniaturized microplate chemiluminescence assay for determination of methyl parathion (MP) was developed in 384-microwell plates. Zirconia (ZrO(2)) was added in microwell for adsorption of acetylcholinesterase (AChE). The developed assay is based on inhibition of AChE by MP. A good dynamic range 0.008-1,000 ng/mL was obtained for MP with limit of detection 0.008 ng/mL. Intrabatch and interbatch reproducibility for miniaturized assay was obtained with % RSD up to 3.07 and 5.66, respectively. In 384 well plate formats, 70 samples were simultaneously analyzed within 20 min with assay volume of 41.5 μL. The application of developed assay was extended for MP remediation. Column containing ZrO(2) was utilized for remediation where MP was selectively adsorbed. Under optimized condition, adsorption of MP on ZrO(2) was found to be 98-99% with 2-h contact time in real water samples. Adsorption of MP on ZrO(2) column followed by quantification using developed bioassay provides a novel approach to monitor remediation. The applicability of assay was successfully extended for determination of MP in water samples after removal through ZrO(2).

  16. Kinetic analysis of the hydrolysis of methyl parathion using citrate-stabilized 10 nm gold nanoparticles.

    PubMed

    Nita, Rafaela; Trammell, Scott A; Ellis, Gregory A; Moore, Martin H; Soto, Carissa M; Leary, Dagmar H; Fontana, Jake; Talebzadeh, Somayeh F; Knight, D Andrew

    2016-02-01

    "Ligand-free" citrate-stabilized 10 nm gold nanoparticles (AuNPs) promote the hydrolysis of the thiophosphate ester methyl parathion (MeP) on the surface of gold as a function of pH and two temperature values. At 50 °C, the active surface gold atoms show catalytic turnover ∼4 times after 8 h and little turnover of gold surface atoms at 25 °C with only 40% of the total atoms being active. From Michaelis-Menten analysis, k(cat) increases between pH 8 and 9 and decreases above pH 9. A global analysis of the spectral changes confirmed the stoichiometric reaction at 25 °C and the catalytic reaction at 50 °C and mass spectrometry confirmed the identity of p-nitrophenolate (PNP) product. Additional decomposition pathways involving oxidation and hydrolysis independent of the formation of PNP were also seen at 50 °C for both catalyzed and un-catalyzed reactions. This work represents the first kinetic analysis of ligand-free AuNP catalyzed hydrolysis of a thiophosphate ester.

  17. Improving the thermostability of a methyl parathion hydrolase by adding the ionic bond on protein surface.

    PubMed

    Su, Yidan; Tian, Jian; Wang, Ping; Chu, Xiaoyu; Liu, Guoan; Wu, Ningfeng; Fan, Yunliu

    2011-10-01

    The thermostability of the methyl parathion hydrolase (MPH_OCH) from Ochrobactrum sp. M231 was improved using site-directed mutagenesis. Two prolines (Pro76 and Pro78) located on the protein surface were selected for mutations after inspection of the sequence alignment of MPH_OCH and OPHC2, a thermostable organophosphorus hydrolase from Pseudomonas pseudoalcaligenes C2-1. The temperature of the double-point mutant (P76D/P78K) at which the mutant lost 50% of its activity (T50) was approximately 68 °C, which is higher than that of WT enzyme (64 °C), P76D (67 °C), and P78K (59 °C). Structural analysis of P76D/P78K indicated that the substituted residues (Asp76 and Lys78) could generate an ionic bond and increase the structural electrostatic energy, which could then increase the stability of the protein. These results also suggest that the thermal stability of proteins could be improved by adding the ionic bond on protein surface.

  18. Probing the mechanisms for the selectivity and promiscuity of methyl parathion hydrolase.

    PubMed

    Purg, Miha; Pabis, Anna; Baier, Florian; Tokuriki, Nobuhiko; Jackson, Colin; Kamerlin, Shina Caroline Lynn

    2016-11-13

    Diverse organophosphate hydrolases have convergently evolved the ability to hydrolyse man-made organophosphates. Thus, these enzymes are attractive model systems for studying the factors shaping enzyme functional evolution. Methyl parathion hydrolase (MPH) is an enzyme from the metallo-β-lactamase superfamily, which hydrolyses a wide range of organophosphate, aryl ester and lactone substrates. In addition, MPH demonstrates metal-ion-dependent selectivity patterns. The origins of this remain unclear, but are linked to open questions about the more general role of metal ions in functional evolution and divergence within enzyme superfamilies. Here, we present detailed mechanistic studies of the paraoxonase and arylesterase activities of MPH complexed with five different transition metal ions, and demonstrate that the hydrolysis reactions proceed via similar pathways and transition states. However, while it is possible to discern a clear structural origin for the selectivity between different substrates, the selectivity between different metal ions appears to lie instead in the distinct electrostatic properties of the metal ions themselves, which causes subtle changes in transition state geometries and metal-metal distances at the transition state rather than significant structural changes in the active site. While subtle, these differences can be significant for shaping the metal-ion-dependent activity patterns observed for this enzyme.This article is part of the themed issue 'Multiscale modelling at the physics-chemistry-biology interface'.

  19. Sequential role of biosorption and biodegradation in rapid removal, degradation and utilization of methyl parathion as a phosphate source by a new cyanobacterial isolate Scytonema sp. BHUS-5.

    PubMed

    Tiwari, Balkrishna; Singh, Savita; Chakraborty, Sindhunath; Verma, Ekta; Mishra, Arun Kumar

    2017-03-20

    A new isolate of genus Scytonema distinct from its closest relative Scytonema hofmanni was found efficient in removal and degradation of organophosphorus pesticide methyl parathion (MP). The cyanobacterial isolate was also capable to utilize the phosphorous present in the methyl parathion following its degradation which was evident from the increase in growth (chlorophyll content), biomass, protein content and total phosphorous in comparison to cyanobacterium grown in phosphate deficient cultures. The rapid removal of MP by the cyanobacterium during initial 6 hours of incubation was defined by the pseudo second order of biosorption kinetics model, which has indicated the involvement of chemosorption in initial removal of pesticide. Further degradation of MP was also confirmed by the appearance of p-nitrophenol in the medium after 24 hour of incubation. Thus the cyanobacterial isolate of Scytonema sp. BHUS-5 seems to be a potential bioremediation agent for the removal of organophosphorus pesticide methyl parathion from the habitat.

  20. Characterization of a fenpropathrin-degrading strain and construction of a genetically engineered microorganism for simultaneous degradation of methyl parathion and fenpropathrin.

    PubMed

    Hong, Yuanfan; Zhou, Jin; Hong, Qing; Wang, Qian; Jiang, Jiandong; Li, Shunpeng

    2010-11-01

    A gram-negative fenpropathrin-degrading bacterial strain Sphingobium sp. JQL4-5 was isolated from the wastewater treatment sludge of an insecticide factory. Strain JQL4-5 showed the ability to degrade other pyrethroid insecticides, but it was not able to degrade methyl parathion. To enhance its degrading range of substrate, a methyl parathion hydrolase gene (mpd) was successfully introduced into the chromosome of strain JQL4-5 with a mini-Tn-transposon system. A genetically engineered microorganism (GEM) named JQL4-5-mpd resulted, which was capable of simultaneously degrading methyl parathion and fenpropathrin. Soil treatment results indicated that JQL4-5-mpd is a promising multifunctional bacterium in the bioremediation of multiple pesticide-contaminated environments.

  1. Distinción Empírica Entre Engagement y Trabajolismo en Enfermeras Hospitalarias de Japón: Efecto Sobre la Calidad del Sueño y el Desempeño Laboral

    PubMed Central

    Kubota, Kazumi; Shimazu, Akihito; Kawakami, Norito; Takahashi, Masaya; Nakata, Akinori; Schaufeli, Wilmar B.

    2016-01-01

    Objetivo El objetivo de este estudio es demostrar la distinción entre engagement y trabajolismo, estudiando su relación con la calidad del sueño y el desempeño laboral. Método Un total de 447 enfermeras de 3 hospitales de Japón fueron entrevistadas mediante un cuestionario autoadministrado que incluía la escala Utrecht (UWES, Utrecht Work Engagement Scale), la Escala de Adicción al Trabajo Holandesa (DUWAS, Dutch Workaholism Scale), preguntas sobre la calidad del sueño (7 ítems) con respecto a (1) dificultad para conciliar el sueño, (2) dificultad para mantener el sueño, (3) despertar temprano por la mañana, (4) dormirse o tomar siestas durante el día, (5) somnolencia diurna excesiva en el trabajo, (6) dificultad para despertarse por la mañana, y (7) despertar cansado en la mañana, y el Cuestionario sobre Salud y Desempeño (CSD) de la Organización Mundial de la Salud. Resultados Los modelos de ecuaciones estructurales demostraron que el engagement se relaciona positivamente con la calidad del sueño y el rendimiento laboral, mientras que el trabajolismo tiene una relación negativa con la calidad del sueño y el desempeño laboral. Conclusión Los resultados indican que el engagement y el trabajolismo son conceptualmente diferentes. El primero tiene una connotación positiva, mientras que el segundo se asocia de manera negativa al bienestar (buena calidad del sueño y buen rendimiento en el trabajo). PMID:26752805

  2. Comparative analyses of genotoxicity, oxidative stress and antioxidative defence system under exposure of methyl parathion and hexaconazole in barley (Hordeum vulgare L.).

    PubMed

    Dubey, Pragyan; Mishra, Amit Kumar; Singh, Ashok Kumar

    2015-12-01

    The present study aims to evaluate the comparative effects of methyl parathion and hexaconazole on genotoxicity, oxidative stress, antioxidative defence system and photosynthetic pigments in barley (Hordeum vulgare L. variety karan-16). The seeds were exposed with three different concentrations, i.e. 0.05, 0.1 and 0.5 % for 6 h after three pre-soaking durations 7, 17 and 27 h which represents G1, S and G2 phases of the cell cycle, respectively. Ethyl methane sulphonate, a well-known mutagenic agent and double distilled water, was used as positive and negative controls, respectively. The results indicate significant decrease in mitotic index with increasing concentrations of pesticides, and the extent was higher in methyl parathion. Chromosomal aberrations were found more frequent in methyl parathion than hexaconazole as compared to their respective controls. Treatment with the pesticides induced oxidative stress which was evident with higher contents of H2O2 and lipid peroxidation, and the increase was more prominent in methyl parathion. Contents of total phenolics were increased; however, soluble protein content showed a reverse trend. Among the enzymatic antioxidants, activities of superoxide dismutase and peroxidase were significantly up-regulated, and more increase was noticed in hexaconazole. Increments in total chlorophyll and carotenoid contents were observed up to 0.1 % but decreased at higher concentration (0.5 %), and the reductions were more prominent in methyl parathion than hexaconazole as compared to their respective controls. Methyl parathion treatment caused more damage in the plant cells of barley as compared to hexaconazole, which may be closely related to higher genotoxicity and oxidative stress.

  3. A rat mammary tumor model induced by the organophosphorous pesticides parathion and malathion, possibly through acetylcholinesterase inhibition.

    PubMed Central

    Cabello, G; Valenzuela, M; Vilaxa, A; Durán, V; Rudolph, I; Hrepic, N; Calaf, G

    2001-01-01

    Environmental chemicals may be involved in the etiology of breast cancers. Many studies have addressed the association between cancer in humans and agricultural pesticide exposure. Organophosphorous pesticides have been used extensively to control mosquito plagues. Parathion and malathion are organophosphorous pesticides extensively used to control a wide range of sucking and chewing pests of field crops, fruits, and vegetables. They have many structural similarities with naturally occurring compounds, and their primary target of action in insects is the nervous system; they inhibit the release of the enzyme acetylcholinesterase at the synaptic junction. Eserine, parathion, and malathion are cholinesterase inhibitors responsible for the hydrolysis of body choline esters, including acetylcholine at cholinergic synapses. Atropine, a parasympatholytic alkaloid, is used as an antidote to acetylcholinesterase inhibitors. The aim of this study was to examine whether pesticides were able to induce malignant transformation of the rat mammary gland and to determine whether alterations induced by these substances increase the cholinergic activation influencing such transformation. These results showed that eserine, parathion, and malathion increased cell proliferation of terminal end buds of the 44-day-old mammary gland of rats, followed by formation of 8.6, 14.3, and 24.3% of mammary carcinomas, respectively, after about 28 months. At the same time, acetylcholinesterase activity decreased in the serum of these animals from 9.78 +/- 0.78 U/mL in the control animals to 3.05 +/- 0.06 U/mL; 2.57 +/- 0.15 U/mL; and 3.88 +/- 0.44 U/mL in the eserine-, parathion-, and malathion-treated groups, respectively. However, atropine alone induced a significant (p < 0.05) decrease in the acetylcholinesterase activity from the control value of 9.78 +/- 0.78 to 4.38 +/- 0.10 for atropine alone, to 1.32 +/- 0.06 for atropine in combination with eserine, and 2.39 +/- 0.29 for atropine with

  4. Urinary excretion of metabolites following a single dermal dose of [14C]methyl parathion in pregnant rats.

    PubMed

    Abu-Qare, A W; Abou-Donia, M B

    2000-09-07

    The identification and kinetics of urinary excretion of metabolites of uniformly phenyl-labeled O,O-dimethyl O-4-nitrophenyl phosphorothioate ([14C]methyl parathion) were carried out following a single dermal dose of 10.0 mg (10 microCi)/kg in pregnant Sprague-Dawley rats at 14-18 days of gestation. Urine was collected at each time interval of 1, 2, 4, 12, 24, 48, 72, and 96 h after dosing. Total p-nitrophenol in the conjugated and non-conjugated metabolites was measured as a marker of methyl parathion exposure. Elimination of radioactivity in the urine was rapid. Of the total 14C urinary excretion, 30% of the dose was excreted within 4 h, while 50 and 90% of the dose were recovered in the urine by 24 and 96 h, respectively. Excretion rate of total radioactivity was 60 microgram methyl parathion equivalent/h (1.4 mg/day). By the end of the 96-h experiment, conjugated and non-conjugated metabolites accounted for 78.1 and 21.9%, respectively. Of the non-conjugated metabolites, p-nitrophenol and O,O-dimethyl O-4-nitrophenyl phosphate (methyl paraoxon) were identified by high performance liquid chromatography (HPLC) that accounted for 20%, and 1.9% of total urinary excretion, respectively. Appearance and disappearance rate constants of p-nitrophenol in urine were 0.12 and 0.048 microgram/h, respectively. Conjugated metabolites were classified as: glucuronides 12% of urinary excretion, sulfates 3%, hot sulfuric acid hydrolysable residues 47% and 16.1% remained as unidentified water soluble metabolites. Direct hot acid hydrolysis of urine yielded 49% of extractable 14C-radioactivity compared to 62% when hot acid hydrolysis followed the enzymatic hydrolysis. The presence of the conjugated metabolites as the major class of metabolites of the total excretion indicates that determining only unbound p-nitrophenol as a biological marker for methyl parathion exposure underestimates total urinary excretion of p-nitrophenol. Sequential enzymatic and acid hydrolyses of urine prior

  5. Effects of the organophosphorus pesticide Folisuper 600 (methyl parathion) on the heart function of bullfrog tadpoles, Lithobates catesbeianus (Shaw, 1802).

    PubMed

    Costa, M J; Ribeiro, L R; Salla, R F; Gamero, F U; Alves, L M L M; Silva-Zacarin, E C M

    2015-11-01

    The aim of this work was to evaluate whether the heart function of bullfrog tadpoles (25 Gosner stage) is affected by their acute exposure (48 h) to a sub-lethal concentration (10 µg.L-1) of the active principle of the organophosphorus pesticide Folisuper 600R (methyl parathion - MP). Our results demonstrated that MP causes not only a reduction in tadpoles' cardiac ventricular mass, resulting in a marked reduction in their cardiac twitch force, but also impairs their swimming performance, irrespective of increasing their heart rate. Together, these findings indicate that low and realistic concentration of MP have a negative impact on tadpoles' performance, jeopardizing their survival.

  6. In vitro dermal absorption of methyl salicylate, ethyl parathion, and malathion: first responder safety.

    PubMed

    Moody, Richard P; Akram, Mohammed; Dickson, Eva; Chu, Ih

    2007-06-01

    In vitro tests with fresh dermatomed (0.3 to 0.4 mm thick) female breast skin and one leg skin specimen were conducted in Bronaugh flow-through Teflon diffusion cells with three chemicals used to simulate chemical warfare agents: 14C-radiolabeled methyl salicylate (MES), ethyl parathion (PT), and malathion (MT), at three dose levels (2, 20, and 200 mM). Tests were conducted at a skin temperature of 29 degrees C using a brief 30-min exposure to the chemical and a 6.5-h receivor collection period. Rapid absorption of all three chemicals was observed, with MES absorbed about 10-fold faster than PT and MT. For MES, PT, and MT, respectively, there was 32%, 7%, and 12% absorption into the receivor solution (Hank's HEPES buffered saline with 4% bovine serum albumin [BSA], pH 7.4) at the low dose (2 mM), 17%, 2%, and 3% at the medium dose (20 mM), and 11%, 1%, and 1% at the high dose (200 mM) levels. Including the skin depot for MES, PT, and MT, respectively, there was 40%, 41%, and 21% (low dose), 26%, 16%, and 8% (medium dose), and 13%, 19%, and 10% (high does) absorption. Efficacy of skin soap washing conducted at the 30 min exposure time ranged from 31% to 86%, varying by chemical and dose level. Skin depot levels were highest for the relatively lipophilic PT. "Pseudo" skin permeability coefficient (K(p)) data declined with dose level, suggesting skin saturation had occurred. An in-depth comparison with literature data was conducted and risk assessment of first responder exposure was briefly considered.

  7. Genetic damage caused by methyl-parathion in mouse spermatozoa is related to oxidative stress

    SciTech Connect

    Pina-Guzman, B.; Solis-Heredia, M.J.; Rojas-Garcia, A.E.; Uriostegui-Acosta, M.; Quintanilla-Vega, B. . E-mail: mquintan@cinvestav.mx

    2006-10-15

    Organophosphorous (OP) pesticides are considered genotoxic mainly to somatic cells, but results are not conclusive. Few studies have reported OP alterations on sperm chromatin and DNA, and oxidative stress has been related to their toxicity. Sperm cells are very sensitive to oxidative damage which has been associated with reproductive dysfunctions. We evaluated the effects of methyl-parathion (Me-Pa; a widely used OP) on sperm DNA, exploring the sensitive stage(s) of spermatogenesis and the relationship with oxidative stress. Male mice (10-12-weeks old) were administered Me-Pa (3-20 mg/kg bw/i.p.) and euthanized at 7- or 28-days post-treatment. Mature spermatozoa were obtained and evaluated for chromatin structure through SCSA (Sperm Chromatin Structure Assay; DNA Fragmentation Index parameters: Mean DFI and DFI%) and chromomycin-A{sub 3} (CMA{sub 3})-staining, for DNA damage through in situ-nick translation (NT-positive) and for oxidative stress through lipid peroxidation (LPO; malondialdehyde production). At 7-days post-treatment (mature spermatozoa when Me-Pa exposure), dose-dependent alterations in chromatin structure (Mean DFI and CMA{sub 3}-staining) were observed, as well as increased DNA damage, from 2-5-fold in DFI% and NT-positive cells. Chromatin alterations and DNA damage were also observed at 28-days post-treatment (cells at meiosis at the time of exposure); suggesting that the damage induced in spermatocytes was not repaired. Positive correlations were observed between LPO and sperm DNA-related parameters. These data suggest that oxidative stress is related to Me-Pa alterations on sperm DNA integrity and cells at meiosis (28-days post-treatment) and epididymal maturation (7-days post-treatment) are Me-Pa targets. These findings suggest a potential risk of Me-Pa to the offspring after transmission.

  8. Methyl-parathion decreases sperm function and fertilization capacity after targeting spermatocytes and maturing spermatozoa

    SciTech Connect

    Pina-Guzman, Belem; Sanchez-Gutierrez, M.; Marchetti, Francesco; Hernandez-Ochoa, I.; Solis-Heredia, M.J .; Quintanilla-Vega, B.

    2009-05-03

    Paternal germline exposure to organophosphorous pesticides (OP) has been associated with reproductive failures and adverse effects in the offspring. Methyl parathion (Me-Pa), a worldwide-used OP, has reproductive adverse effects and is genotoxic to sperm. Oxidative damage has been involved in the genotoxic and reproductive effects of OP. The purpose of this study was to determine the effects of Me-Pa on spermatozoa function and ability to fertilize. Male mice were exposed to Me-Pa (20 mg/kg bw, i.p.) and spermatozoa from epididymis-vas deferens were collected at 7 or 28 days post-treatment (dpt) to assess the effects on maturing spermatozoa and spermatocytes, respectively. DNA damage was evaluated by nick translation (NT-positive cells) and SCSA (percentDFI); lipoperoxidation (LPO) by malondialdehyde production; sperm function by spontaneous- and induced-acrosome reactions (AR); mitochondrial membrane potential (MMP) by using the JC-1 flurochrome; and, fertilization ability by an in vitro assay and in vivo mating. Results showed alterations in DNA integrity (percentDFI and NT-positive cells) at 7 and 28 dpt, in addition to decreased sperm quality and a decrease in induced-AR; reduced MMP and LPO was observed only at 7 dpt. We found negative correlations between LPO and all sperm alterations. Altered sperm functional parameters were associated with reduced fertilization rates at both times, evaluated either in vitro or in vivo. These results show that Me-Pa exposure of maturing spermatozoa and spermatocytes affects many sperm functional parameters that result in a decreased fertilizing capacity. Oxidative stress seems to be a likely mechanism ofthe detrimental effects of Me-Pa in male germ cells.

  9. Methyl-parathion decreases sperm function and fertilization capacity after targeting spermatocytes and maturing spermatozoa.

    PubMed

    Piña-Guzmán, B; Sánchez-Gutiérrez, M; Marchetti, F; Hernández-Ochoa, I; Solís-Heredia, M J; Quintanilla-Vega, B

    2009-07-15

    Paternal germline exposure to organophosphorous pesticides (OP) has been associated with reproductive failures and adverse effects in the offspring. Methyl-parathion (Me-Pa), a worldwide-used OP, has reproductive adverse effects and is genotoxic to sperm, possibly via oxidative damage. This study investigated the stages of spermatogenesis susceptible to be targeted by Me-Pa exposure that impact on spermatozoa function and their ability to fertilize. Male mice were exposed to Me-Pa (20 mg/kg bw, i.p.) and spermatozoa from epididymis-vas deferens were collected at 7 or 28 days post-treatment (dpt) to assess the effects on maturing spermatozoa and spermatocytes, respectively. Spermatozoa were examined for DNA damage by nick translation (NT-positive cells) and SCSA (%DFI), lipoperoxidation (LPO) by malondialdehyde production, sperm function by spontaneous- and induced-acrosome reactions (AR), mitochondrial membrane potential (MMP) by using the JC-1 fluorochrome, and fertilization ability by an in vitro assay and in vivo mating. Alterations on DNA integrity (%DFI and NT-positive cells) in spermatozoa collected at 7 and 28 dpt, and decreases in sperm quality and induced-AR were observed; reduced MMP and LPO were observed at 7 dpt only. Negative correlations between LPO and sperm alterations were found. Altered sperm functional parameters evaluated either in vitro or in vivo were associated with reduced fertilization rates at both times. These results show that Me-Pa exposure of maturing spermatozoa and spermatocytes affects many sperm functional parameters that result in a decreased fertilizing capacity. Oxidative stress seems to be a likely mechanism of the detrimental effects of Me-Pa exposure in male germ cells.

  10. Biodegradation of methyl parathion and p-nitrophenol: evidence for the presence of a p-nitrophenol 2-hydroxylase in a Gram-negative Serratia sp. strain DS001.

    PubMed

    Pakala, Suresh B; Gorla, Purushotham; Pinjari, Aleem Basha; Krovidi, Ravi Kumar; Baru, Rajasekhar; Yanamandra, Mahesh; Merrick, Mike; Siddavattam, Dayananda

    2007-01-01

    A soil bacterium capable of utilizing methyl parathion as sole carbon and energy source was isolated by selective enrichment on minimal medium containing methyl parathion. The strain was identified as belonging to the genus Serratia based on a phylogram constructed using the complete sequence of the 16S rRNA. Serratia sp. strain DS001 utilized methyl parathion, p-nitrophenol, 4-nitrocatechol, and 1,2,4-benzenetriol as sole carbon and energy sources but could not grow using hydroquinone as a source of carbon. p-Nitrophenol and dimethylthiophosphoric acid were found to be the major degradation products of methyl parathion. Growth on p-nitrophenol led to release of stoichiometric amounts of nitrite and to the formation of 4-nitrocatechol and benzenetriol. When these catabolic intermediates of p-nitrophenol were added to resting cells of Serratia sp. strain DS001 oxygen consumption was detected whereas no oxygen consumption was apparent when hydroquinone was added to the resting cells suggesting that it is not part of the p-nitrophenol degradation pathway. Key enzymes involved in degradation of methyl parathion and in conversion of p-nitrophenol to 4-nitrocatechol, namely parathion hydrolase and p-nitrophenol hydroxylase component "A" were detected in the proteomes of the methyl parathion and p-nitrophenol grown cultures, respectively. These studies report for the first time the existence of a p-nitrophenol hydroxylase component "A", typically found in Gram-positive bacteria, in a Gram-negative strain of the genus Serratia.

  11. Removal of methyl parathion from artificial off-gas using a bioreactor containing a constructed microbial consortium.

    PubMed

    Li, Lin; Yang, Chao; Lan, Wensheng; Xie, Shan; Qiao, Chuanling; Liu, Junxin

    2008-03-15

    Methyl parathion (MP), a highly toxic organophosphorus pesticide, was widely used for agriculture crop protection. During the production of MP and the process of MP-containing wastewater treatment, MP can release into the atmosphere and will do great harm to adjacent communities. A consortium comprised of an engineered microorganism and a natural p-nitrophenol (PNP) degrader was assembled for complete mineralization of MP. We genetically engineered Escherichia coli BL21 (DE3) enabling the overexpression of methyl parathion hydrolase (MPH). In addition, we isolated Ochrobactrum sp. strain LL-1 that utilized PNP, a product of MP hydrolysis, as the sole carbon, nitrogen, and energy source. The coculture effectively hydrolyzed 0.2 mM MP and prevented the accumulation of PNP in suspended culture. A laboratory-scale bioreactor containing the dual-species consortium was developed for the treatment of artificial off-gas containing MP. The bioreactor maintained over 98% of average MP removal efficiency over a 75 day period, and PNP produced from hydrolysis of MP was degraded completely, indicating that complete mineralization of MP was achieved. The strategy of linking degrading consortium to a bioreactor may provide an alternative to physicochemical abatement technologies for the treatment of waste-gas streams containing MP as well as other PNP-substituted organophosphates.

  12. Potentiometric stripping analysis of methyl and ethyl parathion employing carbon nanoparticles and halloysite nanoclay modified carbon paste electrode.

    PubMed

    Sanghavi, Bankim J; Hirsch, Gary; Karna, Shashi P; Srivastava, Ashwini K

    2012-07-20

    Carbon nanoparticles (CNPs) and halloysite nanoclay (HNC) modified carbon paste electrode (HNC-CNP-CPE) was developed for the determination of methyl parathion (MP) and ethyl parathion (EP). The electrochemical behavior of these molecules was investigated employing cyclic voltammetry (CV), chronocoulometry (CC), electrochemical impedance spectroscopy (EIS) and potentiometric stripping analysis (PSA). After optimization of analytical conditions employing this electrode at pH 5.0 in acetate buffer (0.1 M), the peak currents were found to vary linearly with its concentration in the range of 1.55×10(-9) to 3.67×10(-6) M and 1.21×10(-9) to 4.92×10(-6) M for MP and EP, respectively. The detection limits (S/N=3) of 4.70×10(-10) M and 3.67×10(-10) M were obtained for MP and EP, respectively, using PSA. The prepared modified electrode showed several advantages such as simple preparation method, high sensitivity, very low detection limits and excellent reproducibility. The proposed method was employed for the determination of MP and EP in fruits, vegetables, water and soil samples.

  13. Genetically modified microorganism Spingomonas paucimobilis UT26 for simultaneously degradation of methyl-parathion and γ-hexachlorocyclohexane.

    PubMed

    Lan, Wen S; Lu, Ti K; Qin, Zhi F; Shi, Xiu J; Wang, Jin J; Hu, Yun F; Chen, Bin; Zhu, Yi H; Liu, Zheng

    2014-07-01

    Bioremediation of pesticide residues by bacteria is an efficient and environmentally friendly method to deal with environmental pollution. In this study, a genetically modified microorganism (GMM) named UT26XEGM was constructed by introducing a parathion hydrolase gene into an initially γ-hexachlorocyclohexane (γ-HCH) degrading bacterium Spingomonas paucimobilis UT26. In order to reduce its potential risk of gene escaping into the environment for the public concern on biosafety, a suicide system was also designed that did not interfere with the performance of the GMM until its physiological function was activated by specific signal. The system was designed with circuiting suicide cassettes consisting of killing genes gef and ecoRIR from Escherichia coli controlled by Pm promoter and the xylS gene. The cell viability and original degradation characteristics were not affected by the insertion of exogenous genes. The novel GMM was capable of degrading methyl-parathion and γ-HCH simultaneously. In laboratory scale testing, the recombinant bacteria were successfully applied to the bioremediation of mixed pesticide residues with the activity of self-destruction after 3-methylbenzoate induction.

  14. Square wave voltammetric determination of methyl parathion using ZrO2-nanoparticles modified carbon paste electrode.

    PubMed

    Parham, H; Rahbar, N

    2010-05-15

    A carbon paste electrode is modified with ZrO(2)-nanoparticles and its application for square wave voltammetric (SWV) detection of methyl parathion, MP (organophosphate pesticide) is reported. The nano-ZrO(2) shows a strong affinity toward the phosphate group on methyl parathion molecules, which provides sensitivity and selectivity of the modified carbon paste electrode. Instrumental and chemical parameters influencing the voltammetric response are optimized for MP determination. Under optimum experimental conditions the peak current is linear to MP concentration over the range of 5.0-3000.0 ng mL(-1) with a correlation coefficient of 0.9992. The limit of detection (LOD) and limit of quantification (LOQ) for MP based on three and ten times the standard deviation of the blank (3S(b), 10S(b)) were 2.0 and 5.7 ng mL(-1) (n=20) for MP, respectively. The recovery values from quality control (QC) samples of water solutions containing low, middle and high concentrations of MP (50, 100 and 800 ng mL(-1)) were 98.0+/-2.3%, 92.5+/-4.9% and 97.6+/-2.8%, respectively. The electrode is successfully applied for the determination of MP in different water samples.

  15. A transposable class I composite transposon carrying mph (methyl parathion hydrolase) from Pseudomonas sp. strain WBC-3.

    PubMed

    Wei, Min; Zhang, Jun-Jie; Liu, Hong; Wang, Shu-Jun; Fu, He; Zhou, Ning-Yi

    2009-03-01

    Pseudomonas sp. strain WBC-3 utilizes methyl parathion (O,O-dimethyl O-p-nitrophenol phosphorothioate) or para-nitrophenol as the sole source of carbon, nitrogen and energy. A gene encoding methyl parathion hydrolase (MPH) had been characterized previously and found to be located on a typical class I composite transposon that comprised IS6100 (Tnmph). In this study, the transposability of this transposon was confirmed by transposition assays in two distinct mating-out systems. Tnmph was demonstrated to transpose efficiently in a random manner in Pseudomonas putida PaW340 by Southern blot and in Ralstonia sp. U2 by sequence analysis of the Tnmph insertion sites, both exhibiting MPH activity. The linkage of the mph-like gene with IS6100, together with the transposability of Tnmph, as well as its capability to transpose in other phylogenetically divergent bacterial species, suggest that Tnmph may contribute to the wide distribution of mph-like genes and the adaptation of bacteria to organophosphorus compounds.

  16. Improving the thermostability of methyl parathion hydrolase from Ochrobactrum sp. M231 using a computationally aided method.

    PubMed

    Tian, Jian; Wang, Ping; Huang, Lu; Chu, Xiaoyu; Wu, Ningfeng; Fan, Yunliu

    2013-04-01

    Good protein thermostability is very important for the protein application. In this report, we propose a strategy which contained a prediction method to select residues related to protein thermal stability, but not related to protein function, and an experiment method to screen the mutants with enhanced thermostability. The prediction strategy was based on the calculated site evolutionary entropy and unfolding free energy difference between the mutant and wild-type (WT) methyl parathion hydrolase enzyme from Ochrobactrum sp. M231 [Ochr-methyl parathion hydrolase (MPH)]. As a result, seven amino acid sites within Ochr-MPH were selected and used to construct seven saturation mutagenesis libraries. The results of screening these libraries indicated that six sites could result in mutated enzymes exhibiting better thermal stability than the WT enzyme. A stepwise evolutionary approach was designed to combine these selected mutants and a mutant with four point mutations (S274Q/T183E/K197L/S192M) was selected. The Tm and T50 of the mutant enzyme were 11.7 and 10.2 °C higher, respectively, than that of the WT enzyme. The success of this design methodology for Ochr-MPH suggests that it was an efficient strategy for enhancing protein thermostability and suitable for protein engineering.

  17. Removal of methyl parathion and tetrachlorvinphos by a bacterial consortium immobilized on tezontle-packed up-flow reactor.

    PubMed

    Yáñez-Ocampo, Gustavo; Sánchez-Salinas, Enrique; Ortiz-Hernández, M Laura

    2011-11-01

    A tezontle-packed up-flow reactor (TPUFR) with an immobilized bacterial consortium for biological treatment of methyl-parathion and tetrachlorvinphos was evaluated. These organophosphate pesticides are widely used in Mexico for insect and mite control, respectively. With the aim of developing a tool for pesticide biodegradation, four flow rates (0.936, 1.41, 2.19, and 3.51 l/h) and four hydraulic residence times (0.313, 0.206, 0.133, and 0.083 h) were evaluated in a TPUFR. In the bioreactor, with an operating time of 8 h and a flow of 0.936 l/h, we obtained 75% efficiency in the removal of methyl-parathion and tetrachlorvinphos. Their adsorptions in the volcanic rock were 9% and 6%, respectively. It was demonstrated that the removal of pesticides was due to the biological activity of the immobilized bacterial consortium. We confirmed the decrease in toxicity in the treated effluent from the bioreactor through the application of acute toxicity tests on Eisenia foetida. Immobilization of a bacterial consortium using tezontle as a support is innovative and an economical tool for the treatment of mixtures of organophosphorus pesticide residues.

  18. Environmentally-friendly in situ plated bismuth-film electrode for the quantification of the endocrine disruptor parathion in skimmed milk.

    PubMed

    Gerent, Giles G; Spinelli, Almir

    2016-05-05

    An in situ bismuth-film electrode (BiFE) together with square-wave cathodic voltammetry (SWCV) was used to determine the concentration of the endocrine disruptor parathion in skimmed milk. The experimental conditions (deposition time, deposition potential and Bi (III) concentration) were optimized for the preparation of the BiFE. A glassy carbon electrode was used as the substrate. The selection of the chemical composition of the supporting electrolyte and the solution pH was aimed at improving the reduction of parathion at the BiFE surface. In addition, the parameters of the square-wave cathodic voltammetry were adjusted to improve the sensor performance. A cathodic current identified at -0.523 V increased linearly with the parathion concentration in the range of 0.2-2.0 μmol L(-1) (R=0.999). The sensitivity of the calibration curve obtained was 4.09 μA L μmol(-1), and the limits of detection (LOD) and quantification (LOQ) were 55.7 nmol L(-1) and 169.0 nmol L(-1), respectively. The performance of the sensor was tested using a sample of skimmed milk with parathion added. The same determination was carried out by UV-vis spectroscopy and the results obtained were used for the statistical evaluation of the data obtained.

  19. Development of surface imprinted core-shell nanoparticles and their application in a solid-phase dispersion extraction matrix for methyl parathion.

    PubMed

    Tan, Lei; Li, Weiming; Li, He; Tang, Youwen

    2014-04-04

    Applying molecular imprinting techniques to the surface of functionalized SiO2 allows the preparation of molecularly imprinted polymers (MIPs) with accessible, high affinity and surface exposed binding sites. This paper demonstrates a new strategy for producing such hybrid organic-inorganic surface imprinted silica nanoparticles for specific recognition of methyl parathion. The technique provides surface grafting imprinting in chloroform using amino modified silica nanoparticles as supports, acrylamide as the functional monomer, γ-methacryloxypropyl trimethoxy silane as the grafting agent, and methyl parathion as a template. The amino propyl functional monomer layer directs the selective occurrence of imprinting polymerization at the silica surface through copolymerization of grafting agents with functional monomers, but also acts as an assistive monomer to drive the template into the formed polymer shells to create effective recognition sites. The resulting MIPs-SiO2 nanoparticles display three-dimensional core-shell architectures and large surface areas. The molecularly imprinted shell provides recognition sites for methyl parathion, with the materials exhibiting excellent performance for selecting the template. Using MIPs-SiO2 nanoparticles as a matrix of solid-phase dispersion extraction sorbents, trace amounts of methyl parathion are selectivity extracted from pear and green vegetable samples while simultaneously eliminating matrix interferences, attaining recoveries of 84.7-94.4% for the samples.

  20. Neonatal parathion exposure and interactions with a high-fat diet in adulthood: Adenylyl cyclase-mediated cell signaling in heart, liver and cerebellum.

    PubMed

    Adigun, Abayomi A; Wrench, Nicola; Levin, Edward D; Seidler, Frederic J; Slotkin, Theodore A

    2010-04-05

    Organophosphates are developmental neurotoxicants but recent evidence points to additional adverse effects on metabolism and cardiovascular function. One common mechanism is disrupted cell signaling mediated through cyclic AMP, targeting neurohumoral receptors, G-proteins and adenylyl cyclase (AC) itself. Earlier, we showed that neonatal parathion evokes later upregulation of the hepatic AC pathway in adolescence but that the effect wanes by young adulthood; nevertheless metabolic changes resembling prediabetes persist. Here, we administered parathion to neonatal rats (postnatal days 1-4, 0.1 or 0.2 mg/kg/day), straddling the threshold for cholinesterase inhibition, but we extended the studies to much later, 5 months of age. In addition, we investigated whether metabolic challenge imposed by consuming a high-fat diet for 7 weeks would exacerbate neonatal parathion's effects. Parathion alone increased the expression or function of G(i), thus reducing AC responses to fluoride. Receptors controlling AC activity were also affected: beta-adrenergic receptors (betaARs) in skeletal muscle were increased, whereas those in the heart were decreased, and the latter also showed an elevation of m(2)-muscarinic acetylcholine receptors, which inhibit AC. The high-fat diet also induced changes in AC signaling, enhancing the hepatic AC response to glucagon while impairing the cardiac response to fluoride or forskolin, and suppressing betaARs and m(2)-muscarinic receptors; the only change in the cerebellum was a decrease in betaARs. Although there were no significant interactions between neonatal parathion exposure and a high-fat diet, their convergent effects on the same signaling cascade indicate that early OP exposure, separately or combination with dietary factors, may contribute to the worldwide increase in the incidence of obesity and diabetes.

  1. Identification of mechanisms involved in the acute airway toxicity induced by parathion.

    PubMed

    Segura, P; Chávez, J; Montaño, L M; Vargas, M H; Delaunois, A; Carbajal, V; Gustin, P

    1999-12-01

    Organophosphates are still widely used worldwide and cause thousands of intoxications every year. In this work we investigated the mechanisms of parathion (Pth) airway toxicity, using biochemical and functional approaches. A plethysmographic technique for unrestrained guinea pigs was used to analyze Pth-induced modifications of airway mechanics and responsiveness to acetylcholine (ACh: 0.1-3.2 mg/ml, 2-min inhalation each dose). The isolated perfused rabbit lung preparation was used to study the acute effects of Pth on airway responsiveness to ACh (10(-8)-10(-3) M), histamine (10(-8)-10(-3) M) and substance P (10(-10)-10(-6) M), pulmonary acetylcholinesterase inhibition and cytochrome P450 (P450) activity, and their modifications with previous administration of Pth (1 mg/kg s.c. daily, 7 days). We found that: (1) In guinea pigs Pth (3.2-17 mg/kg i.p.) produced a dose-dependent increase in a lung resistance index (iRL), which was greatly reverted (approximately 50%) by salbutamol (2 mg/ml, 2-min inhalation, or 10 microg/kg i.p.). This salbutamol effect was transient (5-10 min), suggesting that this bronchodilator triggered additional obstructive mechanisms. (2) Pth increased the water content in lung parenchyma samples, but not in trachea or bronchi, and augmented the respiratory secretions measured through monosaccharide content in bronchoalveolar lavage. (3) The increase in iRL was greater in female animals, probably due to a higher P450 basal activity, and completely blocked by pharmacological inhibition of P450 with piperonyl butoxide (500 mg/kg i.p.). (4) In male guinea pigs a subclinical dose of Pth (10 mg/kg i.p.) induced airway hyperresponsiveness to ACh. In isolated perfused rabbit lung Pth (10(-6) M) produced airway hyperresponsiveness to ACh and histamine, the latter prevented by atropine (10(-5) M). (5) Repetitive exposure to subclinical doses (1 mg/kg s.c.) of Pth during 1 week caused approximately 80% inhibition of P450 activity in rabbits, which was

  2. Determination of Parathion and Carbaryl Pesticides in Water and Food Samples Using a Self Assembled Monolayer/Acetylcholinesterase Electrochemical Biosensor

    PubMed Central

    Pedrosa, Valber A.; Caetano, Josiane; Machado, Sergio A. S.; Bertotti, Mauro

    2008-01-01

    An acetylcholinesterase (AchE) based amperometric biosensor was developed by immobilisation of the enzyme onto a self assembled modified gold electrode. Cyclic voltammetric experiments performed with the SAM-AchE biosensor in phosphate buffer solutions (pH = 7.2) containing acetylthiocholine confirmed the formation of thiocholine and its electrochemical oxidation at Ep = 0.28 V vs Ag/AgCl. An indirect methodology involving the inhibition effect of parathion and carbaryl on the enzymatic reaction was developed and employed to measure both pesticides in spiked natural water and food samples without pre-treatment or pre-concentration steps. Values higher than 91-98.0% in recovery experiments indicated the feasibility of the proposed electroanalytical methodology to quantify both pesticides in water or food samples. HPLC measurements were also performed for comparison and confirmed the values measured amperometrically. PMID:27873775

  3. Impaired brain StAR and HSP70 gene expression in zebrafish exposed to Methyl-Parathion based insecticide.

    PubMed

    da Rosa, João Gabriel Santos; Koakoski, Gessi; Piato, Angelo L; Bogo, Maurício Reis; Bonan, Carla Denise; Barcellos, Leonardo José Gil

    2016-01-01

    Fish production ponds and natural water body areas located in close proximity to agricultural fields receive water with variable amounts of agrochemicals, and consequently, compounds that produce adverse effects may reach nontarget organisms. The aim of this study was to investigate whether waterborne methyl-parathion-based insecticide (MPBI) affected gene expression patterns of brain glucocorticoid receptor (GR), steroidogenic acute regulatory protein (StAR), and heat shock protein 70 (hsp70) in adult zebrafish (Danio rerio) exposed to this chemical for 96 h. Treated fish exposed to MPBI-contaminated water showed an inhibition of brain StAR and hsp70 gene expression. Data demonstrated that MPBI produced a decrease brain StAR and hsp70 gene expression.

  4. Simultaneous biodegradation of methyl parathion and carbofuran by a genetically engineered microorganism constructed by mini-Tn5 transposon.

    PubMed

    Jiang, Jiandong; Zhang, Ruifu; Li, Rong; Gu, Ji-Dong; Li, Shunpeng

    2007-08-01

    A genetically engineered microorganism (GEM) capable of simultaneous degrading methyl parathion (MP) and carbofuran was successfully constructed by random insertion of a methyl parathion hydrolase gene (mpd) into the chromosome of a carbofuran degrading Sphingomonas sp. CDS-1 with the mini-transposon system. The GEM constructed was relatively stable and cell viability and original degrading characteristic was not affected compared with the original recipient CDS-1. The effects of temperature, initial pH value, inoculum size and alternative carbon source on the biodegradation of MP and carbofuran were investigated. GEM cells could degrade MP and carbofuran efficiently in a relatively broad range of temperatures from 20 to 30 degrees C, initial pH values from 6.0 to 9.0, and with all initial inoculation cell densities (10(5)-10(7) CFU ml(-1)), even if alternative glucose existed. The optimal temperature and initial pH value for GEM cells to simultaneously degrade MP and carbofuran was at 30 degrees C and at pH 7.0. The removal of MP and carbofuran by GEM cells in sterile and non-sterile soil were also studied. In both soil samples, 50 mg kg(-1) MP and 25 mg kg(-1) carbofuran could be degraded to an undetectable level within 25 days even if there were indigenous microbial competition and carbon sources effect. In sterile soil, the biodegradation rates of MP and carbofuran were faster, and the decline of the inoculated GEM cells was slower compared with that in non-sterile soil. The GEM constructed in this study was potential useful for pesticides bioremediation in natural environment.

  5. Studies on combined effects of organophosphates or carbamates and morsodren in birds. II. Plasma and cholinesterase in quail fed morsodren and orally dosed with parathion or carbofuran

    USGS Publications Warehouse

    Dieter, M.P.; Ludke, J.L.

    1978-01-01

    The degree of interaction between mercury and cholinesterase inhibiting pesticides was determined by comparing enzyme responses to sublethal dosages of parathion or carbofuran in quail fed 0.05, 0.5, or 5.0 ppm morsodren for 18 weeks. A statistically significant interaction was defined as greater brain cholinesterase inhibition in morsodren-fed than in clean-fed birds following pesticide dosage. The tissue residues of mercury that accumulated before significant mercury-parathion interactions occurred were higher than levels that might be expected in natural populations, but significant mercury-carbofuran interactions occurred in birds that had only accumulated 1.0 ppm liver mercury. The results indicate that indiscriminate usage of cholinesterase inhibiting pesticides are dangerous, since natural populations of fish-eating birds oftentimes contain this magnitude of mercury.

  6. Neonatal Parathion Exposure and Interactions with a High-Fat Diet in Adulthood: Adenylyl Cyclase-Mediated Cell Signaling in Heart, Liver and Cerebellum

    PubMed Central

    Adigun, Abayomi A.; Wrench, Nicola; Levin, Edward D.; Seidler, Frederic J.; Slotkin, Theodore A.

    2010-01-01

    Organophosphates are developmental neurotoxicants but recent evidence points to additional adverse effects on metabolism and cardiovascular function. One common mechanism is disrupted cell signaling mediated through cyclic AMP, targeting neurohumoral receptors, G-proteins and adenylyl cyclase (AC) itself. Earlier, we showed that neonatal parathion evokes later upregulation of the hepatic AC pathway in adolescence but that the effect wanes by young adulthood; nevertheless metabolic changes resembling prediabetes persist. Here, we administered parathion to neonatal rats (postnatal days 1-4, 0.1 or 0.2 mg/kg/day), straddling the threshold for cholinesterase inhibition, but we extended the studies to much later, 5 months of age. In addition, we investigated whether metabolic challenge imposed by consuming a high-fat diet for 7 weeks would exacerbate neonatal parathion’s effects. Parathion alone increased the expression or function of Gi, thus reducing AC responses to fluoride. Receptors controlling AC activity were also affected: β-adrenergic receptors (βARs) in skeletal muscle were increased, whereas those in the heart were decreased, and the latter also showed an elevation of m2-muscarinic acetylcholine receptors, which inhibit AC. The high-fat diet also induced changes in AC signaling, enhancing the hepatic AC response to glucagon while impairing the cardiac response to fluoride or forskolin, and suppressing βARs and m2-muscarinic receptors; the only change in the cerebellum was a decrease in βARs. Although there were no significant interactions between neonatal parathion exposure and a high-fat diet, their convergent effects on the same signaling cascade indicate that early OP exposure, separately or combination with dietary factors, may contribute to the worldwide increase in the incidence of obesity and diabetes. PMID:20074626

  7. Determination of benomyl, diphenyl, o-phenylphenol, thiabendazole, chlorpyrifos, methidathion, and methyl parathion in oranges by solid-phase extraction, liquid chromatography, and gas chromatography.

    PubMed

    Yamazaki, Y; Ninomiya, T

    1999-01-01

    A simple and rapid method was developed for determination of benomyl, diphenyl (DP), o-phenylphenol (OPP), thiabendazole (TBZ), chlorpyrifos, methidathion, and methyl parathion in whole oranges. These compounds were extracted from a mixture of samples and anhydrous sodium acetate with ethyl acetate. The ethyl acetate extract was concentrated and cleaned up by passing through tandem solid-phase extraction columns consisting of anion-exchange and primary/secondary amine bonded silica. The eluate was concentrated and volume was adjusted with methanol for subsequent liquid chromatography (LC) and gas chromatography (GC). Benomyl (as methyl-2-benzimidazole carbamate, MBC), DP, OPP, and TBZ residues were determined by LC with fluorescence detection. Recoveries at 3 fortified levels (0.1, 1, and 10 micrograms/g) ranged from 63.9 to 97.4%, with coefficients of variation (CVs) of 1.6 to 15.5%. Limits of detection (LODs) were 0.01 microgram/g for DP, OPP, TBZ and 0.05 microgram/g for benomyl. Chlorpyrifos, methidathion, and methyl parathion residues were determined by GC with flame photometric detection. Recoveries ranged from 90.4 to 97.0%, with CVs of 2.1 to 5.9%. LODs were 0.005 microgram/g for chlorpyrifos and methyl parathion, and 0.01 microgram/g for methidathion.

  8. Parathion, a cholinesterase-inhibiting plaguicide induces changes in tertiary villi of placenta of women exposed: a scanning electron microscopy study.

    PubMed

    Levario-Carrillo, M; Feria-Velasco, A; De Celis, R; Ramos-Martínez, E; Córdova-Fierro, L; Solís, F J

    2001-01-01

    The objective of this work was to describe the anatomy of placentas from women who were at risk of exposure to parathion during their pregnancy, when examined with the light and scanning electron microscopes. Twenty term placentas were analyzed; 10 from women living in an agricultural area, who were at risk of exposure to parathion during their pregnancy, and 10 from women living in an urban area, not expressly exposed to pesticides. Each sample was examined with both light and scanning electron microscopes. Cholinesterase activity was significantly reduced in blood from women of the exposed group. In some placentas of women exposed to parathion, recent microinfarctions, microcalcifications and increased deposition of fibrinoid material were seen, along with a larger proportion of atypical characteristics of villi, such as bullous and balloon-like formations with nonhomogeneous surface, and other areas devoid of microvilli. These observations suggest that in chronic exposure to pesticides, the rate of atypical characteristics of placental villi increases, which could be related to changes in the fetus biology. In this study, one newborn from the exposed group showed intrauterine growth retardation and another one, some signs of hypoxia.

  9. Cloning of the organophosphorus pesticide hydrolase gene clusters of seven degradative bacteria isolated from a methyl parathion contaminated site and evidence of their horizontal gene transfer.

    PubMed

    Zhang, Ruifu; Cui, Zhongli; Zhang, Xiaozhou; Jiang, Jiandong; Gu, Ji-Dong; Li, Shunpeng

    2006-10-01

    Seven organophosphorus pesticide-degrading bacteria harboring the methyl parathion degrading (mpd) gene were isolated from a methyl parathion contaminated site. In this study, the 4.7 kb mpd gene cluster, conserved in all seven bacteria capable of degrading methyl parathion, was cloned and further analysis revealed that this cluster contained five ORFs and the mpd gene was associated with a mobile element, IS6100. In addition to mpd gene ORF and tnpA ORF, three other ORFs showed high homology to the permease component of ABC-type transport system, the general secretion pathway protein B, and the RNA polymerase sigma 70 factor, respectively. The mpd genes of these 7 strains were subcloned and expressed in E. coli, SDS-PAGE and zymogram analysis showed that two expression products of mpd genes in E. coli were found, but the one without signal peptide showed the hydrolytic activities. Our evidences collectively suggest that mpd gene cluster may be disseminated through horizontal gene transfer based on phylogenetic analysis of the cluster and their host bacterial strains, and comparisons of GC content of the cluster and respective host's chromosome.

  10. Construction of an engineered strain free of antibiotic resistance gene markers for simultaneous mineralization of methyl parathion and ortho-nitrophenol.

    PubMed

    Liu, Yan; Wei, Qing; Wang, Shu-Jun; Liu, Hong; Zhou, Ning-Yi

    2010-06-01

    Pseudomonas sp. strain NyZ402, a native soil organism that grows on para-nitrophenol (PNP), was genetically engineered for the simultaneous degradation of methyl parathion (MP) and ortho-nitrophenol (ONP) by integrating mph (methyl parathion hydrolase gene) from Pseudomonas sp. strain WBC-3 and onpAB (ONP 2-monooxygenase and ONP o-benzoquinone reductase genes) from Alcaligenes sp. strain NyZ215 into the genome of strain NyZ402. Methyl parathion hydrolase (MPH), ONP 2-monooxygenase (OnpA) and o-benzoquinone reductase (OnpB) were constitutively expressed in the engineered strain NyZ-MO. Strain NyZ-MO was free of exogenous antibiotic resistance gene markers and the introduced genes were genetically stable. Degradation experiments showed that strain NyZ-MO could utilize MP or ONP as the sole carbon and energy source, and mineralize 0.1 mM MP-0.1 mM ONP simultaneously. This method may serve as a useful strategy for the construction of engineered strains in the degradation of multiple environmental pollutants.

  11. The vital function of Fe3O4@Au nanocomposites for hydrolase biosensor design and its application in detection of methyl parathion.

    PubMed

    Zhao, Yuting; Zhang, Weiying; Lin, Yuehe; Du, Dan

    2013-02-07

    A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe(3)O(4) core was synthesized using cysteamine (SH-NH(2)) as linker, and characterized by TEM, XPS, UV and electrochemistry. Then a hydrolase biosensor, based on self-assembly of methyl parathion hydrolase (MPH) on the Fe(3)O(4)@Au nanocomposite, was developed for sensitive and selective detection of the organophosphorus pesticide (OP) methyl parathion. The magnetic nanocomposite provides an easy way to construct the enzyme biosensor by simply exerting an external magnetic field, and also provides a simple way to renew the electrode surface by removing the magnet. Unlike inhibition-based enzyme biosensors, the hydrolase is not poisoned by OPs and thus is reusable for continuous measurement. AuNPs not only provide a large surface area, high loading efficiency and fast electron transfer, but also stabilize the enzyme through electrostatic interactions. The MPH biosensor shows rapid response and high selectivity for detection of methyl parathion, with a linear range from 0.5 to 1000 ng mL(-1) and a detection limit of 0.1 ng mL(-1). It also shows acceptable reproducibility and stability. The simplicity and ease of operation of the proposed method has great potential for on-site detection of P-S containing pesticides and provides a promising strategy to construct a robust biosensor.

  12. The Vital Function of Fe3O4@Au nanocomposites for Hydrolase Biosensor Design and Its Application in Detection of Methyl Parathion

    SciTech Connect

    Zhao, Yuting; Zhang, Weiying; Lin, Yuehe; Du, Dan

    2013-02-04

    A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe3O4 core was synthesized using cysteamine (SH–NH2) as linker, and characterized by TEM, XPS, UV and electrochemistry. Then a hydrolase biosensor, based on self-assembly of methyl parathion hydrolase (MPH) on the Fe3O4@Au nanocomposite, was developed for sensitive and selective detection of the organophosphorus pesticide (OP) methyl parathion. The magnetic nanocomposite provides an easy way to construct the enzyme biosensor by simply exerting an external magnetic field, and also provides a simple way to renew the electrode surface by removing the magnet. Unlike inhibition-based enzyme biosensors, the hydrolase is not poisoned by OPs and thus is reusable for continuous measurement. AuNPs not only provide a large surface area, high loading efficiency and fast electron transfer, but also stabilize the enzyme through electrostatic interactions. The MPH biosensor shows rapid response and high selectivity for detection of methyl parathion, with a linear range from 0.5 to 1000 ng/mL and a detection limit of 0.1 ng/mL. It also shows acceptable reproducibility and stability. The simplicity and ease of operation of the proposed method has great potential for on-site detection of P–S containing pesticides and provides a promising strategy to construct a robust biosensor.

  13. Down-regulation of muscarinic receptors and the m3 subtype in white-footed mice by dietary exposure to parathion

    USGS Publications Warehouse

    Jett, D.A.; Hill, E.F.; Fernando, J.C.; Eldefrawi, M.E.; Eldefrawi, A.T.

    1993-01-01

    The effect of ad libitum dietary exposure (as occurs in the field) to parathion for 14 d was investigated on the muscarinic acetylcholine receptor (mAChR) in brains and submaxillary glands of adults of a field species, the white-footed mouse Peromyscus leucopus. Immunoprecipitation using subtype selective antibodies revealed that the relative ratios of the m1-m5 mAChR subtypes in Peromyscus brain were similar to those in rat brain. There was little variability in acetylcholinesterase (AChE) activity in control mice brains but large variability in 39 exposed mice, resulting from differences in food ingestion and parathion metabolism. Accordingly, data on radioligand binding to mAChRs in each mouse brain were correlated with brain AChE activity in the same mouse, and AChE inhibition served as a biomarker of exposure reflecting in situ paraoxon concentrations. Exposure to parathion for 14 d reduced maximal binding (Bmax) of [3H]quinuclidinyl benzilate ([3H]QNB), [3H]-N-methylscopolamine ([3H]NMS), and [3H]-4-diphenylacetoxy-N-methylpiperidine methiodide ([3H]-4-DAMP) by up to approximately 58% without affecting receptor affinities for these ligands. Maximal reduction in Bmax of [3H]QNB and [3H]-4-DAMP binding occurred in mice with highest AChE inhibition, while equivalent maximal reduction in Bmax of [3H]NMS occurred in mice with only approximately 10% AChE inhibition, without further change at higher parathion doses. This is believed to be due to the hydrophilicity of [3H]NMS, which limits its accessibility to internalized desensitized receptors. In submaxillary glands (mAChRs are predominantly m3 subtype), there were significant dose-dependent reductions in [3H]QNB binding and m3 mRNA levels in exposed mice, revealed by Northern blot analyses. The reduction in m3 receptors is suggested to result mostly from reduced synthesis at the transcription level, rather than from translational or posttranslational events. The data suggest that down-regulation of mAChRs occurs

  14. Brain acetylcholinesterase activity recovery following acute methyl parathion intoxication in two feral rodent species: comparison to laboratory rodents

    SciTech Connect

    Roberts, D.K.; Silvey, N.J.; Bailey, E.M. Jr.

    1988-07-01

    Widespread use of organophosphorus insecticides (OPs) has produced both acute and chronic intoxication among nontarget organisms. Most such studies have included fish and birds as opposed to mammals. However, numerous OP toxicity studies have been conducted on laboratory rodents creating a temptation to apply this data to feral rodents. Chronic OP exposure has been reported to produce cholinergic adaptation which in turn lowers mortality rates following a subsequent acute anticholinesterase exposure. The relevance that these laboratory rodent studies have on feral rodents is subject to debate. Field studies involving OP exposure among nontarget feral mammals have produced contradictory results. Increased mortality as a result of repeated OP application has been reported. This observation may be of considerable importance to nontarget feral rodent populations due to the repetitive nature of OP application protocols. The ability of feral rodents to recover brain AChE activity (BAA) between OP application intervals undoubtedly promotes their survival. This study investigated and compared BAA recovery following acute oral methyl parathion intoxication among 2 feral rodent species and among 2 common laboratory rodent species.

  15. Entrapment of methyl parathion hydrolase in cross-linked poly(γ-glutamic acid)/gelatin hydrogel.

    PubMed

    Xie, Jianfei; Zhang, Huiwen; Li, Xu; Shi, Yuanliang

    2014-02-10

    Methyl parathion hydrolase (MPH) is an important enzyme in hydrolyzing toxic organophosphorus (OP) compounds. However, MPH is easily deactivated when subjected to extreme environmental conditions and is difficult to recover from the reaction system for reuse, thereby limiting its practical application. To address these shortcomings, we examined the entrapment of MPH in an environment-friendly, biocompatible and biodegradable cross-linked poly(γ-glutamic acid)/gelatin hydrogel. The cross-linked poly(γ-glutamic acid)/gelatin hydrogels were prepared with different gelatin/poly(γ-glutamic acid) mass ratios using water-soluble carbodiimide as the cross-linking agent. The MPH-entrapped cross-linked poly(γ-glutamic acid)/gelatin hydrogel (CPE-MPH) not only possessed improved thermostability, pH stability, and reusability but also exhibited enhanced efficiency in hydrolyzing OP compounds. Furthermore, CPE-MPH possesses high water-absorbing and water-retaining capabilities. We believe that the cross-linked poly(γ-glutamic acid)/gelatin hydrogels are an attractive carrier for the entrapment of diverse enzymes, affording a new approach for enzyme entrapment.

  16. Bioaccumulation of methyl parathion and its toxicology in several species of the freshwater community in Ignacio Ramirez dam in Mexico.

    PubMed

    De La Vega Salazar, M Y; Tabche, L M; García, C M

    1997-10-01

    Environmental contamination by pesticides, including the presence of chemical residues in aquatic wildlife, is a widespread ecological problem. Methyl parathion (MP), a widely used organophosphorate insecticide, is a potent neurotoxic in both vertebrates and invertebrates. The effect of a subchronic exposure to MP in aquatic organisms was evaluated in a natural ecosystem measuring acetyl cholinesterase (AChE) and gamma glutamil transpeptidase (GGT) activity. Two samples were conducted. Physicochemical characterization was done at each sampling time and organisms were collected. MP and metabolite 4-nitrophenol (4-NP) concentrations were measured in water sediment and organisms. The major differences in physical features between season were an increase of turbidity and salinity and depletion of dissolved oxygen in the rainy season. MP and 4-NP are bioconcentrated in organisms in response to environmental stress. MP concentration was measured in different size/age and reproductive stages separately. A significant concentration in reproductive tissues (plants)/unborn progeny (animals) was always found, and this can affect egg viability. The metabolite 4-NP is bioaccumulated and is toxic because it causes an increase of AChE activity. GGT activity was higher than that in controls. The increase in enzymatic activity provides a detoxification mechanism from chronic sublethal exposure, when hepatic glutation depletion occurs, and may be an indicator of liver damage.

  17. Improving the secretion of a methyl parathion hydrolase in Pichia pastoris by modifying its N-terminal sequence.

    PubMed

    Wang, Ping; Huang, Lu; Jiang, Hu; Tian, Jian; Chu, Xiaoyu; Wu, Ningfeng

    2014-01-01

    Pichia pastoris is commonly used to express and secrete target proteins, although not all recombinant proteins can be successfully produced. In this study, we used methyl parathion hydrolase (MPH) from Ochrobactrum sp. M231 as a model to study the importance of the N-terminus of the protein for its secretion. While MPH can be efficiently expressed intracellularly in P. pastoris, it is not secreted into the extracellular environment. Three MPH mutants (N66-MPH, D10-MPH, and N9-MPH) were constructed through modification of its N-terminus, and the secretion of each by P. pastoris was improved when compared to wild-type MPH. The level of secreted D10-MPH was increased to 0.21 U/mL, while that of N9-MPH was enhanced to 0.16 U/mL. Although N66-MPH was not enzymatically active, it was secreted efficiently, and was identified by SDS-PAGE. These results demonstrate that the secretion of heterologous proteins in P. pastoris may be improved by modifying their N-terminal structures.

  18. Photocatalytic degradation of commercial methyl parathion in aqueous suspension containing La-doped TiO2 nanoparticles.

    PubMed

    Chen, Hao; Shen, Min; Chen, Ruiwen; Dai, Ke; Peng, Tianyou

    2011-10-01

    The photocatalytic degradation of a commercial methyl parathion (MP) under UV irradiation was investigated in aqueous suspension containing lanthanum-doped mesoporous TiO2 nanoparticles (La/m-TiO2) as photocatalyst. The rate of photodecomposition of MP was measured using UV-Vis spectrophotometry, and its mineralization was followed using ion chromatography (IC). The identification of possible intermediate products was carried out using several powerful analytical techniques such as gas chromatography-pulsed flame photometric detector (GC-PFPD) and high performance liquid chromatography-mass spectroscopy (HPLC-MS). Under our conditions, complete disappearance of 20 mg/L of MP occurred within 2 h of illumination, whereas complete mineralization of MP was not achieved through IC analysis. There was a single intermediate product found in the research, which was identified to be methyl paraoxon, owing to the substitution of S by the O atom in the MP molecule. Based on the experimental facts, it is concluded that MP was mainly attacked not by OH radicals but photo-generated holes (h+), resulting from the good adsorption of MP on the catalyst surfaces due to the enhanced adsorption by La doping.

  19. Alteration of the kidney membrane proteome of Mizuhopecten yessoensis induced by low-level methyl parathion exposure.

    PubMed

    Huang, Xiang; Huang, He-Qing

    2012-06-15

    Methyl parathion (MP) is a widely used organophosphorus pesticide that causes severe health and environmental effects. We investigated the alteration of the proteomic profile in the membrane enriched fraction of the kidneys of the scallop Mizuhopecten yessoensis exposed to low-level MP. Gas chromatography analysis showed that MP residues were significantly accumulated in the kidneys and the digestive glands of the scallops. According to two-dimensional electrophoresis, 17 proteins were differentially modulated under MP exposure. The mRNA expressions of 12 differential proteins were analyzed using quantitative PCR, and 10 showed consistent alteration of mRNA level with that of protein expression level. Altered expressions of two proteins (mitochondrial processing peptidase and α-tubulin) were also examined using Western blotting, showing that the mitochondrial processing peptidase was down-regulated but α-tubulin remained unchanged in response to MP exposure. Subcellular locations of all the identified proteins that were predicted using bioinformatics tools indicate that few of them are permanently located in the membrane. The differentially expressed proteins are involved in several critical biological processes, and their relevance to human health has been illuminated. These data taken together have provided some novel insights into the chronic toxicity mechanism of MP and have suggested mitochondrial processing peptidase as a potential biomarker for human health and environmental monitoring.

  20. Methyl parathion imprinted polymer nanoshell coated on the magnetic nanocore for selective recognition and fast adsorption and separation in soils.

    PubMed

    Xu, Shiying; Guo, Changjuan; Li, Yongxian; Yu, Zerong; Wei, Chaohai; Tang, Youwen

    2014-01-15

    Core-shell magnetic methyl parathion (MP) imprinted polymers (Fe3O4@MPIPs) were fabricated by a layer-by-layer self-assembly process. In order to take full advantage of the synergistic effect of hydrogen-binding interactions and π-π accumulation between host and guest for molecular recognition, methacrylic acid and 4-vinyl pyridine were chosen as co-functional monomers and their optimal proportion were investigated. The core-shell and crystalline structure, morphology and magnetic properties of Fe3O4@MPIPs were characterized. The MP-imprinted nanoshell was almost uniform and about 100nm thick. Binding experiments demonstrated that Fe3O4@MPIPs possessed excellent binding properties, including high adsorption capacity and specific recognition, as well as fast adsorption kinetics and a fast phase separation rate. The equilibration adsorption capacity reached up to 9.1mg/g, which was 12 times higher than that of magnetic non-imprinted polymers, while adsorption reached equilibrium within 5min at a concentration of 0.2mmol/L. Furthermore, Fe3O4@MPIPs successfully provided selective separation and removal of MP in soils with a recovery and detection limit of 81.1-87.0% and 5.2ng/g, respectively.

  1. Oxidative Stress, Cytotoxicity, and Genotoxicity Induced by Methyl Parathion in Human Gingival Fibroblasts: Protective Role of Epigallocatechin-3-Gallate.

    PubMed

    Argentin, Gabriella; Divizia, Maurizio; Cicchetti, Rosadele

    2015-01-01

    Organophosphorous (OP) compounds are pesticides frequently released into the environment because of extensive use in agriculture. Among these, methyl parathion (mPT) recently received attention as a consequence of illegal use. The predominant route of human exposure to mPT is via inhalation, but inadvertent consumption of contaminated foods and water may also occur. The goal of this study was to investigate the in vitro effects of mPT on cells in the oral cavity and evaluate the potential protective role of epigallocathechin-3-gallate (EGCG) on these effects. Human gingival fibroblasts (HGF) were exposed to 10, 50, or 100 μ g/ml mPT for 24 h and assessed for oxidative stress, as evidenced by reactive generation of oxygen species (ROS), induction of apoptotic cell death, DNA damage (comet assay and cytochinesis-block micronucleus test), and nitric oxide (NO) production. The results showed that mPT produced significant oxidative stress, cytotoxicity, and genotoxicity and increased NO levels through stimulation of inducible NO synthase expression. Finally, data demonstrated that EGCG (10, 25, or 50 μ M) was able to inhibit the pesticide-induced effects on all parameters studied. Data indicate that cytotoxic and genotoxic effects may be associated with oxidative stress induced by mPT observed in HGF cultures and that EGCG plays a protective role via antioxidant activities.

  2. Biodegradation of methyl parathion and p-nitrophenol by a newly isolated Agrobacterium sp. strain Yw12.

    PubMed

    Wang, Shenghui; Zhang, Chen; Yan, Yanchun

    2012-02-01

    Strain Yw12, isolated from activated sludge, could completely degrade and utilize methyl parathion as the sole carbon, phosphorus and energy sources for growth in the basic salt media. It could also completely degrade and utilize p-nitrophenol as the sole carbon and energy sources for growth in the minimal salt media. Phenotypic features, physiological and biochemical characteristics, and phylogenetic analysis of 16S rRNA sequence showed that this strain belongs to the genus of Agrobacterium sp. Response surface methodology was used to optimize degradation conditions. Under its optimal degradation conditions, 50 mg l(-1) MP was completely degraded within 2 h by strain Yw12 and the degradation product PNP was also completely degraded within 6 h. Furthermore, strain Yw12 could also degrade phoxim, methamidophos, chlorpyrifos, carbofuran, deltamethrin and atrazine when provided as the sole carbon and energy sources. Enzymatic analysis revealed that the MP degrading enzyme of strain Yw12 is an intracellular enzyme and is expressed constitutively. These results indicated that strain Yw12 might be used as a potential and effective organophosphate pesticides degrader for bioremediation of contaminated sites.

  3. Burkholderia zhejiangensis sp. nov., a methyl-parathion-degrading bacterium isolated from a wastewater-treatment system.

    PubMed

    Lu, Peng; Zheng, Liu-Qiang; Sun, Jin-Jin; Liu, Hong-Ming; Li, Shun-Peng; Hong, Qing; Li, Wen-Jun

    2012-06-01

    The taxonomic status of a methyl-parathion-degrading strain, OP-1(T), isolated from a wastewater-treatment system in China, was determined using a polyphasic approach. The rod-shaped cells were Gram-staining-negative, non-spore-forming and non-motile. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel strain belonged to the genus Burkholderia, as it appeared closely related to Burkholderia glathei ATCC 29195(T) (97.4 % sequence similarity), Burkholderia sordidicola KCTC 12081(T) (96.5 %) and Burkholderia bryophila LMG 23644(T) (96.3 %). The major cellular fatty acids, C(16:0), C(17:0) cyclo and C(18:1)ω7c, were also similar to those found in established members of the genus Burkholderia. The genomic DNA G+C content of strain OP-1(T) was 59.4 mol%. The level of DNA-DNA relatedness between the novel strain and the closest recognized species, Burkholderia glathei ATCC 29195(T), was only 30 %. Based on the phenotypic, genotypic and phylogenetic evidence, strain OP-1(T) represents a novel species of the genus Burkholderia, for which the name Burkholderia zhejiangensis sp. nov. is proposed. The type strain is OP-1(T) ( = CCTCC AB 2010354(T) = KCTC 23300(T)).

  4. Biodegradation of methyl parathion by whole cells of marine-derived fungi Aspergillus sydowii and Penicillium decaturense.

    PubMed

    Alvarenga, Natália; Birolli, Willian G; Seleghim, Mirna H R; Porto, André L M

    2014-12-01

    Seven marine fungi strains (Aspergillus sydowii CBMAI 934, A. sydowii CBMAI 935, A. sydowii CBMAI 1241, Penicillium decaturense CBMAI 1234, Penicillium raistrickii CBMAI 931, P. raistrickii CBMAI 1235, and Trichoderma sp. CBMAI 932) were screened by their growth in the presence of methyl parathion (MP) in a solid culture medium. The strains with best growth were A. sydowii CBMAI 935 and P. decaturense CBMAI 1234. Biodegradation reactions were performed in 10, 20 and 30d in a malt extract liquid medium containing commercial MP and whole cells of A. sydowii CBMAI 935 and P. decaturense CBMAI 1234. In 20d, A. sydowii CBMAI 935 was able to degrade all pesticide, whereas P. decaturense CBMAI 1234 promoted a complete degradation in 30d. A. sydowii CBMAI 935 and P. decaturense CBMAI 1234 could degrade the product of the MP enzymatic hydrolysis, p-nitrophenol, on average of 51 and 40% respectively. Both strains used MP as a sole source of carbon and provided satisfactory results. Metabolites detected in the medium showed that the presumable reaction pathway occurred through the activation of MP to its more toxic form, methyl paraoxon, which was further degraded to p-nitrophenol.

  5. Estudio de los Efectos Gravitomagnéticos en Cuerpos Masivos Rotantes

    NASA Astrophysics Data System (ADS)

    Velandia Heredia, N.; Tejeiro, J. M.

    2008-03-01

    A partir del estudio de los Efectos Gravitomagnéticos en cuerpos masivos rotantes, planteamos la expresión para medir el desfase en el tiempo, para diferentes observadores, que se dan cuando viajan dos rayos de luz por una guía de onda o de manera libre (geodésicas), en el plano azimutal y en el plano polar. Con lo anterior queremos abordar el experimento tipo Michelson y Morley, de forma que podamos involucrar el valor de la densidad del momento angular (a) en el retraso temporal para los dos haces de luz que viajan por los brazos del interferómetro, cuando este último es ubicado en el plano ecuatorial.

  6. The vital function of Fe3O4@Au nanocomposites for hydrolase biosensor design and its application in detection of methyl parathion

    NASA Astrophysics Data System (ADS)

    Zhao, Yuting; Zhang, Weiying; Lin, Yuehe; Du, Dan

    2013-01-01

    A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe3O4 core was synthesized using cysteamine (SH-NH2) as linker, and characterized by TEM, XPS, UV and electrochemistry. Then a hydrolase biosensor, based on self-assembly of methyl parathion hydrolase (MPH) on the Fe3O4@Au nanocomposite, was developed for sensitive and selective detection of the organophosphorus pesticide (OP) methyl parathion. The magnetic nanocomposite provides an easy way to construct the enzyme biosensor by simply exerting an external magnetic field, and also provides a simple way to renew the electrode surface by removing the magnet. Unlike inhibition-based enzyme biosensors, the hydrolase is not poisoned by OPs and thus is reusable for continuous measurement. AuNPs not only provide a large surface area, high loading efficiency and fast electron transfer, but also stabilize the enzyme through electrostatic interactions. The MPH biosensor shows rapid response and high selectivity for detection of methyl parathion, with a linear range from 0.5 to 1000 ng mL-1 and a detection limit of 0.1 ng mL-1. It also shows acceptable reproducibility and stability. The simplicity and ease of operation of the proposed method has great potential for on-site detection of P-S containing pesticides and provides a promising strategy to construct a robust biosensor.A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe3O4 core was synthesized using cysteamine (SH-NH2) as linker, and characterized by TEM, XPS, UV and electrochemistry. Then a hydrolase biosensor, based on self-assembly of methyl parathion hydrolase (MPH) on the Fe3O4@Au nanocomposite, was developed for sensitive and selective detection of the organophosphorus pesticide (OP) methyl parathion. The magnetic nanocomposite provides an easy way to construct the enzyme biosensor by simply exerting an external magnetic field, and also provides a simple way to renew the electrode surface by removing the magnet. Unlike

  7. Methyl parathion inhibits the nuclear maturation, decreases the cytoplasmic quality in oocytes and alters the developmental potential of embryos of Swiss albino mice

    SciTech Connect

    Nair, Ramya; Singh, Vikram Jeet; Salian, Sujith Raj; Kalthur, Sneha Guruprasad; D'Souza, Antony Sylvan; Shetty, Pallavi K.; Mutalik, Srinivas; Kalthur, Guruprasad; Adiga, Satish Kumar

    2014-09-15

    Methyl parathion (MP) is one of the most commonly used and extremely toxic organophosphorous group of pesticide. A large number of studies in the literature suggest that it has adverse effects on the male reproductive system. However, there is limited information about its toxicity to the female reproductive system. In the present study we report the toxic effects of methyl parathion on the female reproductive system using Swiss albino mice as the experimental model. The female mice were administered orally with 5, 10 and 20 mg/kg of MP. One week later, the mice were superovulated with pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) to study the quality of the oocytes, spindle organization, developmental potential of early embryos and the DNA integrity in blastocysts. MP exposure resulted in a non-significant decrease in the number of primordial follicles and increased DNA damage in granulosa cells. Though MP did not have any effect on the ovulation it had a significant inhibitory effect on the nuclear maturity of oocytes which was associated with spindle deformity. In addition, the oocytes had higher cytoplasmic abnormalities with depleted glutathione level. Even though it did not have any effect on the fertilization and blastocyst rate at lower doses, at 20 mg/kg MP it resulted in a significant decrease in blastocyst hatching, decrease in cell number and high DNA damage. While low body weight gain was observed in F1 generation from 5 mg/kg group, at higher dose, the body weight in F1 generation was marginally higher than control. Post-natal death in F1 generation was observed only in mice treated with 20 mg/kg MP. In conclusion, we report that MP has adverse effects on the oocyte quality, developmental potential of the embryo and reproductive outcome. - Highlights: • Methyl parathion induces severe cytoplasmic abnormalities in oocytes. • Inhibits nuclear maturation and spindle damage • Poor blastocyst quality and high DNA

  8. Chlorpyrifos-, Diisopropylphosphorofluoridate-, and Parathion-Induced Behavioral and Oxidative Stress Effects: Are They Mediated by Analogous Mechanisms of Action?

    PubMed Central

    Sánchez-Santed, Fernando

    2013-01-01

    Exposure to organophosphates (OPs) can lead to cognitive deficits and oxidative damage. Little is known about the relationship between behavioral deficits and oxidative stress within the context of such exposures. Accordingly, the first experiment was carried out to address this issue. Male Wistar rats were administered 250mg/kg of chlorpyrifos (CPF), 1.5mg/kg of diisopropylphosphorofluoridate (DFP), or 15mg/kg of parathion (PTN). Spatial learning in the water maze task was evaluated, and F2-isoprostanes (F2-IsoPs) and prostaglandin (PGE2) were analyzed in the hippocampus. A second experiment was designed to determine the degree of inhibition of brain acetylcholinesterase (AChE) activity, both the soluble and particulate forms of the enzyme, and to assess changes in AChE gene expression given evidence on alternative splicing of the gene in response to OP exposures. In addition, brain acylpeptide hydrolase (APH) activity was evaluated as a second target for OP-mediated effects. In both experiments, rats were sacrificed at various points to determine the time course of OPs toxicity in relation to their mechanism of action. Results from the first experiment suggest cognitive and emotional deficits after OPs exposure, which could be due to, at least in part, increased F2-IsoPs levels. Results from the second experiment revealed inhibition of brain AChE and APH activity at various time points post OP exposure. In addition, we observed increased brain read-through splice variant AChE (AChE-R) mRNA levels after 48h PTN exposure. In conclusion, this study provides novel data on the relationship between cognitive alterations and oxidative stress, and the diverse mechanisms of action along a temporal axis in response to OP exposures in the rat. PMID:22986948

  9. Differential protein profile in zebrafish (Danio rerio) brain under the joint exposure of methyl parathion and cadmium.

    PubMed

    Ling, Xue-Ping; Lu, Ying-Hua; Huang, He-Qing

    2012-11-01

    As different chemicals, methyl parathion (MP) and cadmium (Cd) can induce neurotoxicity on the brain of aquatic ecosystems. This study aims to explore the differential expression proteins in the brain induced by their joint stress and their joint effects, which are poorly reported, and devotes finding novel biomarkers for monitoring their contamination in water and assessing their neurological effects. The bioaccumulation of MP and Cd in tissues after 96 h of exposure was first analyzed by GC and inductively coupled plasma-MS to provide insights into the interaction. Protein profile changes in the brains of the zebrafish (Danio rerio) exposed to MP and Cd were further investigated using the proteomic approach. The correlation of gene expression on the transcription level of mRNA and the translation level of protein was examined by real-time quantitative PCR and Western blotting analysis. It showed that Cd and MP have an interaction on their bioaccumulation, which suggests that their joint effect over 96 h might be antagonistic. Proteomics revealed that 22 protein spots changed their expression levels under stress, of which 16 proteins were identified using MS. These proteins were involved in oxidation/reduction, metabolism, energy production, receptor activity, and cytoskeleton assembly. Among them, five proteins with a remarkable abundance change are significantly suggested to play important roles in the joint effect. This work demonstrates that there exists an interaction between MP and Cd toxicities, which may aid in our understanding of the mechanism of neurotoxicity induced by joint stress. The results may also provide the possibility of the establishment of candidate biomarkers for monitoring MP and Cd contamination in water.

  10. Enhanced electrochemiluminescence employed for the selective detection of methyl parathion based on a zirconia nanoparticle film modified electrode.

    PubMed

    Zhou, Hankun; Gan, Ning; Hou, Jianguo; Li, Tianhua; Cao, Yuting

    2012-01-01

    A simple, rapid and sensitive electrochemiluminescence (ECL) sensor was proposed for direct measurements of methyl parathion (MP) based on the strong affinity of a nano zirconia particles (ZrO(2) NPs) modified film on the electrode to the phosphoric group. ZrO(2) NPs, which could provide a larger absorption area to immobilize organophosphorus, was firstly modified on the glassy carbon electrode surface to prepare the proposed ECL sensor (ZrO(2)/GC). Subsequently, the ZrO(2)/GC electrode was scanned from -0.8 to +0.6 V to obtain the background signal at 0.44 V in a luminol/KCl solution. Then, a certain concentration of MP was added to an aqueous solution for 240 s, which was absorbed onto the ZrO(2)/GC electrode surface. Moreover, the MP absorbed on the surface of the ZrO(2)/GC electrode enhanced the ECL signal of luminol in the luminol/KCl solution, which increased with the concentration of MP. As a result, a novel ECL sensor was obtained in a luminol/KCl solution. The MP was determined in the range of from 3.8 × 10(-11) to 3.8 × 10(-6) mol L(-1), with a low detection limit of 1.27 × 10(-11) mol L(-1) (S/N = 3). The proposed ECL sensor performance for MP detection will open a new field in the application of rapid and screen detection of ultra-trace amounts of organ phosphorus pesticides (OPs) of vegetables used in farm markets.

  11. Enhanced thermostability of methyl parathion hydrolase from Ochrobactrum sp. M231 by rational engineering of a glycine to proline mutation.

    PubMed

    Tian, Jian; Wang, Ping; Gao, Shan; Chu, Xiaoyu; Wu, Ningfeng; Fan, Yunliu

    2010-12-01

    Protein thermostability can be increased by some glycine to proline mutations in a target protein. However, not all glycine to proline mutations can improve protein thermostability, and this method is suitable only at carefully selected mutation sites that can accommodate structural stabilization. In this study, homology modeling and molecular dynamics simulations were used to select appropriate glycine to proline mutations to improve protein thermostability, and the effect of the selected mutations was proved by the experiments. The structure of methyl parathion hydrolase (MPH) from Ochrobactrum sp. M231 (Ochr-MPH) was constructed by homology modeling, and molecular dynamics simulations were performed on the modeled structure. A profile of the root mean square fluctuations of Ochr-MPH was calculated at the nanosecond timescale, and an eight-amino acid loop region (residues 186-193) was identified as having high conformational fluctuation. The two glycines nearest to this region were selected as mutation targets that might affect protein flexibility in the vicinity. The structures and conformational fluctuations of two single mutants (G194P and G198P) and one double mutant (G194P/G198P) were modeled and analyzed using molecular dynamics simulations. The results predicted that the mutant G194P had the decreased conformational fluctuation in the loop region and might increase the thermostability of Ochr-MPH. The thermostability and kinetic behavior of the wild-type and three mutant enzymes were measured. The results were consistent with the computational predictions, and the mutant G194P was found to have higher thermostability than the wild-type enzyme.

  12. Development of a novel optical biosensor for detection of organophosphorus pesticides based on methyl parathion hydrolase immobilized by metal-chelate affinity.

    PubMed

    Lan, Wensheng; Chen, Guoping; Cui, Feng; Tan, Feng; Liu, Ran; Yushupujiang, Maolidan

    2012-01-01

    We have developed a novel optical biosensor device using recombinant methyl parathion hydrolase (MPH) enzyme immobilized on agarose by metal-chelate affinity to detect organophosphorus (OP) compounds with a nitrophenyl group. The biosensor principle is based on the optical measurement of the product of OP catalysis by MPH (p-nitrophenol). Briefly, MPH containing six sequential histidines (6 × His tag) at its N-terminal was bound to nitrilotriacetic acid (NTA) agarose with Ni ions, resulting in the flexible immobilization of the bio-reaction platform. The optical biosensing system consisted of two light-emitting diodes (LEDs) and one photodiode. The LED that emitted light at the wavelength of the maximum absorption for p-nitrophenol served as the signal light, while the other LED that showed no absorbance served as the reference light. The optical sensing system detected absorbance that was linearly correlated to methyl parathion (MP) concentration and the detection limit was estimated to be 4 μM. Sensor hysteresis was investigated and the results showed that at lower concentration range of MP the difference got from the opposite process curves was very small. With its easy immobilization of enzymes and simple design in structure, the system has the potential for development into a practical portable detector for field applications.

  13. Efectos combinados de la ampliación de la atención primaria de salud y de las transferencias condicionadas de dinero en efectivo sobre la mortalidad infantil en Brasil, 1998–2010*

    PubMed Central

    Guanais, Frederico C.

    2015-01-01

    Objetivos. Examiné los efectos combinados del acceso a la atención primaria mediante el Programa de Salud Familiar (PSF) y las transferencias condicionadas de dinero en efectivo del Programa Bolsa Familia (PBF) sobre la mortalidad infantil posneonatal (MIPN) en Brasil. Métodos. Empleé un análisis ecológico longitudinal usando datos en panel de 4 583 municipios brasileños de 1998 al 2010, con 54 253 observaciones en total. Estimé modelos de regresión de efectos fijos por mínimos cuadrados ordinarios, con la tasa de MIPN como la variable dependiente y el PSF, el PBF y sus interacciones como las principales variables independientes de interés. Resultados. La asociación de una mayor cobertura del PSF con una menor tasa de MIPN se volvió más fuerte conforme aumentaba la cobertura del PBF. En los promedios de todas las demás variables, cuando la cobertura de PBF era 25%, la MIPN predicha fue 5,24 (intervalo de confianza [IC] de 95% = 4,95, 5,53) para una cobertura del PSF de 0%, y de 3,54 (IC de 95% = 2,77, 4,31) para una cobertura del PSF de 100%. Cuando la cobertura del PBF era de 60%, la MIPN predicha fue 4,65 (IC de 95% = 4,36, 4,94) para una cobertura del PSF de 0%, y de 1,38 (IC de 95% = 0,88, 1,89) para una cobertura del PSF de 100%. Conclusiones. El efecto del PSF depende de la ampliación del PBF. Para las poblaciones empobrecidas y subatendidas, la combinación de intervenciones tanto del lado de la oferta como del lado de la demanda podría ser necesaria para mejorar los resultados en salud.

  14. Methyl parathion inhibits the nuclear maturation, decreases the cytoplasmic quality in oocytes and alters the developmental potential of embryos of Swiss albino mice.

    PubMed

    Nair, Ramya; Singh, Vikram Jeet; Salian, Sujith Raj; Kalthur, Sneha Guruprasad; D'Souza, Antony Sylvan; Shetty, Pallavi K; Mutalik, Srinivas; Kalthur, Guruprasad; Adiga, Satish Kumar

    2014-09-15

    Methyl parathion (MP) is one of the most commonly used and extremely toxic organophosphorous group of pesticide. A large number of studies in the literature suggest that it has adverse effects on the male reproductive system. However, there is limited information about its toxicity to the female reproductive system. In the present study we report the toxic effects of methyl parathion on the female reproductive system using Swiss albino mice as the experimental model. The female mice were administered orally with 5, 10 and 20mg/kg of MP. One week later, the mice were superovulated with pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) to study the quality of the oocytes, spindle organization, developmental potential of early embryos and the DNA integrity in blastocysts. MP exposure resulted in a non-significant decrease in the number of primordial follicles and increased DNA damage in granulosa cells. Though MP did not have any effect on the ovulation it had a significant inhibitory effect on the nuclear maturity of oocytes which was associated with spindle deformity. In addition, the oocytes had higher cytoplasmic abnormalities with depleted glutathione level. Even though it did not have any effect on the fertilization and blastocyst rate at lower doses, at 20 mg/kg MP it resulted in a significant decrease in blastocyst hatching, decrease in cell number and high DNA damage. While low body weight gain was observed in F1 generation from 5mg/kg group, at higher dose, the body weight in F1 generation was marginally higher than control. Post-natal death in F1 generation was observed only in mice treated with 20mg/kg MP. In conclusion, we report that MP has adverse effects on the oocyte quality, developmental potential of the embryo and reproductive outcome.

  15. A decrease of intracellular ATP is compensated by increased respiration and acidification at sub-lethal parathion concentrations in murine embryonic neuronal cells: measurements in metabolic cell-culture chips.

    PubMed

    Buehler, S M; Stubbe, M; Gimsa, U; Baumann, W; Gimsa, J

    2011-11-30

    We present a label-free in vitro method for testing the toxic potentials of chemical substances using primary neuronal cells. The cells were prepared from 16-day-old NMRI mouse embryos and cultured on silicon chips (www.bionas.de) under the influence of different parathion concentrations with sensors for respiration (Clark-type oxygen electrodes), acidification (pH-ISFETs) and cell adhesion (interdigitated electrode structures, IDES). After 12 days in vitro, the sensor readouts were simultaneously recorded for 350 min in the presence of parathion applying a serial 1:3 dilution. The parathion-dependent data was fitted by logistic functions. IC(50) values of approximately 105 μM, 65 μM, and 54 μM were found for respiration, acidification, and adhesion, respectively. An IC(50) value of approximately 36 μM was determined from the intracellular ATP-levels of cells, which were detected by an ATP-luminescence assay using micro-well plates. While the intracellular ATP level and cell adhesion showed no deviation from a simple logistic decay, increases of approximately 29% in the respiration and 15% in the acidification rates above the control values were found at low parathion concentrations, indicating hormesis. These increases could be fitted by a modified logistic function. We believe that the label-free, continuous, multi-parametric monitoring of cell-metabolic processes may have applications in systems-biology and biomedical research, as well as in environmental monitoring. The parallel characterization of IC(50) values and hormetic effects may provide new insights into the metabolic mechanisms of toxic challenges to the cell.

  16. Simultaneous Determination of Parathion, Malathion, Diazinon, and Pirimiphos Methyl in Dried Medicinal Plants Using Solid-Phase Microextraction Fibre Coated with Single-Walled Carbon Nanotubes

    PubMed Central

    Ahmadkhaniha, Reza; Samadi, Nasrin; Salimi, Mona; Sarkhail, Parisa; Rastkari, Noushin

    2012-01-01

    A reliable and sensitive headspace solid-phase microextraction gas chromatography-mass spectrometry method for simultaneous determination of different organophosphorus pesticides in dried medicinal plant samples is described. The analytes were extracted by single-walled carbon nanotubes as a new solid-phase microextraction adsorbent. The developed method showed good performance. For diazinon and pirimiphos methyl calibration, curves were linear (r2 ≥ 0.993) over the concentration ranges from 1.5 to 300 ng g−1, and the limit of detection at signal-to-noise ratio of 3 was 0.3 ng g−1. For parathion and malathion, the linear range and limit of detection were 2.5–300 (r2 ≥ 0.991) and 0.5 ng g−1, respectively. In addition, a comparative study between the single-walled carbon nanotubes and a commercial polydimethylsiloxane fibre for the determination of target analytes was carried out. Single-walled carbon nanotubes fibre showed higher extraction capacity, better thermal stability (over 350°C), and longer lifespan (over 250 times) than the commercial polydimethylsiloxane fibre. The developed method was successfully applied to determine target organophosphorus pesticides in real samples. PMID:22645439

  17. Extrapolating laboratory avian toxicity data to free-living birds: Comparison of the toxicity of parathion to captive and free-living European starlings

    USGS Publications Warehouse

    Grue, C.E.; Rattner, B.A.; Bunck, C.M.

    1993-01-01

    In 1985 and 1986, we captured nesting wild female European starlings with young 8-10 days of age. Birds were weighted, banded, and given one of four dosages of the OP insecticide parathion (50, 72, 104 or 150 mg/kg dissolved in corn oil) or pure corn-oil (control). and their young weighed. Nest boxes (7- 12/treatment) were observed and young re-weighed 2-3 days postdose to determine presence/absence of the females. If necessary, males were captured and fate of young used to confirm female response. Brain ChE inhibition in dosed birds (based on a pilot study) was 55-74%. EC50's (failure to return to nest box) for the females was 74 mg/kg in 1985 and 92 mg/kg in 1986. Confidence limit (95%) for these estimates overlapped LD50's for captive female starlings dosed with the OP in spring and early summer 1987 (136, 128 mg/kg, respectively). Results suggest that responses of captive and free-living birds to potentially lethal concentrations of OP's are similar, despite the additional stresses in the wild.

  18. An optical microplate biosensor for the detection of methyl parathion pesticide using a biohybrid of Sphingomonas sp. cells-silica nanoparticles.

    PubMed

    Mishra, Archana; Kumar, Jitendra; Melo, Jose Savio

    2017-01-15

    The previously developed Sphingomonas sp. based optical microplate biosensor for methyl parathion (MP) was good as it detected multiple samples but had poor stability and low sensitivity. The present study aims to overcome these limitations. Silica nanoparticles (Si NP) were thus functionalized with polyethyleneimine (PEI) and the functionalized silica nanoparticles ((f)Si NP) were then integrated with Sphingomonas sp. cells. The process was optimized for hydrolysis of MP into p-nitrophenol (PNP). Integration of (f)Si NP with cells was confirmed by FT-IR analysis. Biohybrid of Sphingomonas sp.-(f)Si NP was immobilized on the wells of microplate and associated directly with the optical transducer of microplate reader. Immobilized biohybrid of Sphingomonas sp.-(f)Si NP was characterized using SEM. A detection range of 0.1-1ppm MP was achieved from the linear range of calibration plot. After integration with (f)Si NP the storage stability of biohybrid was enhanced ten times from 18 to 180 days. This study proves that after interaction of cells with (f)Si NP, improved the sensitivity and stability of the biosensor. Spiked samples were also analyzed and correlated using this biohybrid based biosensor.

  19. Genetically engineered Pseudomonas putida X3 strain and its potential ability to bioremediate soil microcosms contaminated with methyl parathion and cadmium.

    PubMed

    Zhang, Rong; Xu, Xingjian; Chen, Wenli; Huang, Qiaoyun

    2016-02-01

    A multifunctional Pseudomonas putida X3 strain was successfully engineered by introducing methyl parathion (MP)-degrading gene and enhanced green fluorescent protein (EGFP) gene in P. putida X4 (CCTCC: 209319). In liquid cultures, the engineered X3 strain utilized MP as sole carbon source for growth and degraded 100 mg L(-1) of MP within 24 h; however, this strain did not further metabolize p-nitrophenol (PNP), an intermediate metabolite of MP. No discrepancy in minimum inhibitory concentrations (MICs) to cadmium (Cd), copper (Cu), zinc (Zn), and cobalt (Co) was observed between the engineered X3 strain and its host strain. The inoculated X3 strain accelerated MP degradation in different polluted soil microcosms with 100 mg MP kg(-1) dry soil and/or 5 mg Cd kg(-1) dry soil; MP was completely eliminated within 40 h. However, the presence of Cd in the early stage of remediation slightly delayed MP degradation. The application of X3 strain in Cd-contaminated soil strongly affected the distribution of Cd fractions and immobilized Cd by reducing bioavailable Cd concentrations with lower soluble/exchangeable Cd and organic-bound Cd. The inoculated X3 strain also colonized and proliferated in various contaminated microcosms. Our results suggested that the engineered X3 strain is a potential bioremediation agent showing competitive advantage in complex contaminated environments.

  20. Analysis of bacteria degradation products of methyl parathion by liquid chromatography/electrospray time-of-flight mass spectrometry and gas chromatography/mass spectrometry.

    PubMed

    Liu, Jie; Wang, Ling; Zheng, Li; Wang, Xiaoru; Lee, Frank S C

    2006-12-29

    The biodegradation of the organophosphorus insecticide methyl parathion (MP) in aqueous environment by bacteria isolated from river sediment has been studied. Two species of bacteria which show strong MP degradation ability are identified as Shewanella and Vibrio parahaemolyticus. The biodegradation of MP proceeded rapidly with the formation of a series of intermediate products, which were analyzed using a combination of GC/MS and HPLC/ESI-TOFMS techniques. The major products tentatively identified include a series of reduced products of MP. Results demonstrate that the coupling of TOFMS to HPLC enhances further the capability of LC-MS in the identification of polar organic species in complex environmental samples. Degradation pathways leading to the formation of these products are proposed which involves first the reduction of nitro to amino group in MP, followed by combination with some intrinsic matters of bacteria. The mechanism and products from biodegradation are quite different from those of photocatalytic process for which the main intermediates included methyl paraoxon and 4-nitrophenol.

  1. Impacto del Seguro Popular en el gasto catastrófico y de bolsillo en el México rural y urbano, 2005–2008

    PubMed Central

    Sosa-Rubí, Sandra G; Salinas-Rodríguez, Aarón; Galárraga, Omar

    2016-01-01

    Objetivo Estimar el efecto del Seguro Popular (SP) sobre la incidencia del gasto catastrófico en salud (GCS) y sobre el gasto de bolsillo en salud (GBS) en el mediano plazo. Material y métodos Con base en la Encuesta de Evaluación del Seguro Popular (2005–2008), se analizaron los resultados del efecto del SP en la cohorte rural para dos años de seguimiento (2006 y 2008) y en la cohorte urbana para un año (2008). Resultados A nivel conglomerado no se detectaron efectos del SP. A nivel hogar se encontró que el SP tiene un efecto protector en el GCS y en el GBS en consulta externa y hospitalización en zonas rurales; y efectos significativos en la reducción de GBS en consulta externa en zonas urbanas. Conclusiones El SP se muestra como un programa efectivo para proteger a los hogares contra gastos de bolsillo por motivos de salud en el mediano plazo. PMID:22282205

  2. Initial results in the development of a reporter cell line for toxicology studies at gene expression level: activation of the electrophile-responsive element by copper and methyl parathion.

    PubMed

    Almeida, Daniela Volcan; Trindade, Gilma Santos; Geracitano, Laura A; Barros, Daniela Martí; Monserrat, José Maria; Marins, Luis Fernando

    2008-07-01

    Induction of many genes encoding detoxifying enzymes and antioxidant proteins is mediated through a common mechanism, which is controlled by electrophile-responsive elements (EpRE) within the regulatory region of those genes. Copper and methyl parathion are environmental pollutants known to induce the expression of EpRE-mediated genes. In order to evaluate the molecular response triggered by these pollutants, a stable cell line was produced, which carries a transgene comprised of the green fluorescent protein (GFP) reporter gene under transcriptional control of the mouse glutathione-S-transferase (gst1) electrophile-responsive element fused to the mouse metallothionein (mt1) minimal promoter. The rat HTC hepatoma cells were transfected with the EpREmt-GFP construct and successfully selected with G418 antibiotic. EpREmt-GFP HTC cells were treated with 0.002 mg L(-1), 0.02 mg L(-1), 0.2 mg L(-1) and 2 mg L(-1) copper sulfate and 0.001 mg L(-1), 0.01 mg L(-1), 0.1 mg L(-1) and 1 mg L(-1) methyl parathion for 48 h. GFP expression was directly quantified in living cells using a microplate fluorimeter. GFP expression was significantly increased in higher concentrations of both pollutants, showing a 1.80- and 2.58-fold induction of GFP at 2mg copper L(-1) and 1mg methyl parathion L(-1), respectively (p<0.01). The results obtained in the present study demonstrate that the EpREmt-GFP HTC cell line can be an interesting model for further development for the study of the cellular response to aquatic pollutants as well as a new tool for environmental monitoring at the molecular level.

  3. Alkali metal ion catalysis and inhibition in nucleophilic displacement reactions at phosphorus centers: ethyl and methyl paraoxon and ethyl and methyl parathion.

    PubMed

    Um, Ik-Hwan; Shin, Young-Hee; Lee, Seung-Eun; Yang, Kiyull; Buncel, Erwin

    2008-02-01

    We report on the ethanolysis of the P=O and P=S compounds ethyl and methyl paraoxon (1a and 1b) and ethyl and methyl parathion (2a and 2b). Plots of spectrophotometrically measured rate constants, kobsd versus [MOEt], the alkali ethoxide concentration, show distinct upward and downward curvatures, pointing to the importance of ion-pairing phenomena and a differential reactivity of free ions and ion pairs. Three types of reactivity and selectivity patterns have been discerned: (1) For the P=O compounds 1a and 1b, LiOEt > NaOEt > KOEt > EtO-; (2) for the P=S compound 2a, KOEt > EtO- > NaOEt > LiOEt; (3) for P=S, 2b, 18C6-crown-complexed KOEt > KOEt = EtO(-) > NaOEt > LiOEt. These selectivity patterns are characteristic of both catalysis and inhibition by alkali-metal cations depending on the nature of the electrophilic center, P=O vs P=S, and the metal cation. Ground-state (GS) vs transition-state (TS) stabilization energies shed light on the catalytic and inhibitory tendencies. The unprecedented catalytic behavior of crowned-K(+) for the reaction of 2b is noteworthy. Modeling reveals an extreme steric interaction for the reaction of 2a with crowned-K(+), which is responsible for the absence of catalysis in this system. Overall, P=O exhibits greater reactivity than P=S, increasing from 50- to 60-fold with free EtO(-) and up to 2000-fold with LiOEt, reflecting an intrinsic P=O vs P=S reactivity difference (thio effect). The origin of reactivity and selectivity differences in these systems is discussed on the basis of competing electrostatic effects and solvational requirements as function of anionic electric field strength and cation size (Eisenman's theory).

  4. Thionate versus Oxon: comparison of stability, uptake, and cell toxicity of ((14)CH(3)O)(2)-labeled methyl parathion and methyl paraoxon with SH-SY5Y cells.

    PubMed

    Bharate, Sandip B; Prins, John M; George, Kathleen M; Thompson, Charles M

    2010-07-28

    The stability, hydrolysis, and uptake of the organophosphates methyl parathion and methyl paraoxon were investigated in SH-SY5Y cells. The stabilities of ((14)CH(3)O)(2)-methyl parathion ((14)C-MPS) and ((14)CH(3)O)(2)-methyl paraoxon ((14)C-MPO) at 1 microM in culture media had similar half-lives of 91.7 and 101.9 h, respectively. However, 100 microM MPO caused >95% cytotoxicity at 24 h, whereas 100 microM MPS caused 4-5% cytotoxicity at 24 h ( approximately 60% cytotoxicity at 48 h). Greater radioactivity was detected inside cells treated with MPO as compared to MPS, although >80% of the total MPO uptake was primarily dimethyl phosphate (DMP). Maximum uptake was reached after 48 h of (14)C-MPS or (14)C-MPO exposure with total uptakes of 1.19 and 1.76 nM/10(6) cells for MPS and MPO, respectively. The amounts of MPS and MPO detected in the cytosol after 48 h of exposure time were 0.54 and 0.37 nM/10(6) cells, respectively.

  5. Vigilando la Calidad del Agua de los Grandes Rios de la Nacion: El Programa NASQAN del Rio Grande (Rio Bravo del Norte)

    USGS Publications Warehouse

    Lurry, Dee L.; Reutter, David C.; Wells, Frank C.; Rivera, M.C.; Munoz, A.

    1998-01-01

    La Oficina del Estudio Geologico de los Estados Unidos (U.S. Geological Survey, 0 USGS) ha monitoreado la calidad del agua de la cuenca del Rio Grande (Rio Bravo del Norte) desde 1995 como parte de la rediseiiada Red Nacional para Contabilizar la Calidad del Agua de los Rios (National Stream Quality Accounting Network, o NASOAN) (Hooper and others, 1997). EI programa NASOAN fue diseiiado para caracterizar las concentraciones y el transporte de sedimento y constituyentes quimicos seleccionados, encontrados en los grandes rios de los Estados Unidos - incluyendo el Misisipi, el Colorado y el Columbia, ademas del Rio Grande. En estas cuatro cuencas, el USGS opera actualmente (1998) una red de 40 puntos de muestreo pertenecientes a NASOAN, con un enfasis en cuantificar el flujo en masa (la cantidad de material que pasa por la estacion, expresado en toneladas por dial para cada constituyente. Aplicacando un enfoque consistente, basado en la cuantificacion de flujos en la cuenca del Rio Grande, el programa NASOAN esta generando la informacion necesaria para identificar fuentes regionales de diversos contaminantes, incluyendo sustancias qui micas agricolas y trazas elementos en la cuenca. EI efecto de las grandes reservas en el Rio Grande se puede observar segun los flujos de constituyentes discurren a 10 largo del rio. EI analisis de los flujos de constituyentes a escala de la cuenca proveera los medios para evaluar la influencia de la actividad humana sobre las condiciones de calidad del agua del Rio Grande.

  6. Estudio multifrecuencia del medio interestelar cercano a HD 192281

    NASA Astrophysics Data System (ADS)

    Arnal, E. M.; Cappa, C.; Cichowolski, S.; Pineault, S.; St-Louis, N.

    Una de las causas que modifica la estructura y dinámica del medio interestelar es la acción que los vientos de las estrellas de gran masa ejercen sobre el mismo. En este trabajo, mediante el uso de datos interferométricos obtenidos en la banda de radio en la transición de 21-cm del Hidrógeno neutro y de imágenes de la emisión de continuo en las bandas de 408 y 1420 MHz, de imágenes HIRES del satélite IRAS en 60 y 100 micrones, y de observaciones de continuo obtenidas con radiotelescopios de disco simple en 2695, 4850 y 8350 MHz se ha realizado un estudio multifrecuencia de los efectos que los vientos estelares de HD 192281, una estrella de tipo espectral O5 Vn((f))p, han tenido sobre el medio interestelar que rodea a la misma.

  7. Cotranslocation of Methyl Parathion Hydrolase to the Periplasm and of Organophosphorus Hydrolase to the Cell Surface of Escherichia coli by the Tat Pathway and Ice Nucleation Protein Display System ▿

    PubMed Central

    Yang, Chao; Freudl, Roland; Qiao, Chuanling; Mulchandani, Ashok

    2010-01-01

    A genetically engineered Escherichia coli strain coexpressing organophosphorus hydrolase (OPH) and methyl parathion hydrolase (MPH) was constructed for the first time by cotransforming two compatible plasmids. Since these two enzymes have different substrate specificities, the coexpression strain showed a broader substrate range than strains expressing either one of the hydrolases. To reduce the mass transport limitation of organophosphates (OPs) across the cell membrane, MPH and OPH were simultaneously translocated to the periplasm and cell surface of E. coli, respectively, by employing the twin-arginine translocation (Tat) pathway and ice nucleation protein (INP) display system. The resulting recombinant strain showed sixfold-higher whole-cell activity than the control strain expressing cytosolic OP hydrolases. The correct localization of MPH and OPH was demonstrated by cell fractionation, immunoblotting, and enzyme activity assays. No growth inhibition was observed for the recombinant E. coli strain, and suspended cultures retained almost 100% of the activity over a period of 2 weeks. Owing to its high level of activity and superior stability, the recombinant E. coli strain could be employed as a whole-cell biocatalyst for detoxification of OPs. This strategy of utilizing dual translocation pathways should open up new avenues for cotranslocating multiple functional moieties to different extracytosolic compartments of a bacterial cell. PMID:19933341

  8. Simple, rapid and green one-step strategy to synthesis of graphene/carbon nanotubes/chitosan hybrid as solid-phase extraction for square-wave voltammetric detection of methyl parathion.

    PubMed

    Liu, Yan; Yang, Shanli; Niu, Weifen

    2013-08-01

    Simple, rapid, green and one-step electrodeposition strategy was first proposed to synthesis of graphene/carbon nanotubes/chitosan (GR/CNTs/CS) hybrid. The one-step electrodeposition approach for the construction of GR-based hybrid is green environmentally, which would not involve the chemical reduction of graphene oxide (GO) and therefore result in no further contamination. The whole procedure is simple and needs only several minutes. Combining the advantages of GR (large surface area, high conductivity and good adsorption ability), CNTs (high surface area, high enrichment capability and good adsorption ability) and CS (good adsorption and excellent film-forming ability), the obtained GR/CNTs/CS composite could be highly efficient to capture organophosphate pesticides (OPs) and used as solid phase extraction (SPE). The GR/CNTs/CS sensor is used for enzymeless detection of OPs, using methyl parathion (MP) as a model analyte. Significant redox response of MP on GR/CNTs/CS sensor is proved. The linear range is wide from 2.0ngmL(-1) to 500ngmL(-1), with a detection limit of 0.5ngmL(-1). Detection limit of the proposed sensor is much lower than those enzyme-based sensors and many other enzymeless sensors. Moreover, the proposed sensor exhibits high reproducibility, long-time storage stability and satisfactory anti-interference ability. This work provides a green and one-step route for the preparation of GR-based hybrid, and also offers a new promising protocol for OPs analysis.

  9. Contribución al flujo infrarrojo de las estrellas Be de la recombinación dielectrónica del MgII

    NASA Astrophysics Data System (ADS)

    Cruzado, A.; di Rocco, H.; Ringuelet, A.

    Para evaluar la contribución del proceso de recombinación dielectrónica del átomo de MgII al exceso de flujo infrarrojo observado en las estrellas Be, calculamos la energía emitida en las líneas originadas por este proceso. Se evaluaron los efectos de las condiciones físicas del medio, como la temperatura electrónica y la densidad electrónica, sobre el flujo emitido. Se consideró también la influencia de una posible opacidad.

  10. Efectos de la irradiación iónica en hielos de moléculas carbonadas

    NASA Astrophysics Data System (ADS)

    Satorre, M. A.

    En Astrofísica podemos encontrar numerosos contextos en los cuales se observan moléculas en estado sólido que, en condiciones estándar de presión y temperatura, se encontrarían como gases o líquidos. Dichas moléculas se denominan hielos y han sido observadas en nubes densas del medio interestelar, en envolturas circumestelares, en satélites del Sistema Solar, en cometas, etc. Los hielos pueden ser alterados en su composición química debido a diversos factores como por ejemplo variaciones de temperatura o aportes energéticos por parte de la irradiación, ya sea tanto de fotones ultravioleta como de iones. Dependiendo del escenario astrofísico que analicemos, unos factores cobran más importancia que otros. Los experimentos de laboratorio muestran el efecto que produce sobre la composición de los hielos la irradiación iónica, en particular sobre los que contenían alguna molécula con átomos de carbono. Dicha composición se analiza con espectroscopía IR en el rango de 2 a ˜ 25μ m. La aplicabilidad de los resultados de los experimentos es distinta dependiendo de la composición química inicial de los hielos, del tipo de ion utilizado y de la dosis total de irradiación. Existen efectos generales de la irradiación sobre la materia en los experimentos de relevancia astrofísica como son: - la formación de nuevas moléculas, que pueden incluir o no el ion incidente; - la progresiva pérdida de hidrógeno (carbonización) cuando irradiamos muestras que originalmente contienen una determinada relación carbono/hidrógeno; - la variación de la temperatura de sublimación que presentan algunos hielos. Esto puede suceder tanto en hielos que estaban presentes antes de la irradiación como en hielos formados por ésta. Se presentará el papel del ion en la formación de nuevas moléculas a partir de las que originalmente se encontraban en el hielo. Al penetrar en él, el ion provoca distintos procesos como rotura de enlaces y excitaciones electr

  11. El efecto de la difusión del Ne en las propiedades evolutivas y pulsacionales de las enanas blancas

    NASA Astrophysics Data System (ADS)

    Camisassa, M. E.; Miller Bertolami, M. M.; Althaus, L. G.; Córsico, A. H.

    2016-08-01

    Due the large neutron excess of Ne, this isotope rapidly sediments in the interior of the white dwarfs. This process releases an extra amount of energy, thus delaying the cooling times of the white dwarf. Furthermore, the overabundance of Ne in the inner regions of the star, modifies the Brunt-Vaisala frequency, thus, altering its pulsational properties. In this work, we discuss the impact of Ne sedimentation in white dwarfs derived from solar metallicity progenitors (). We performed evolutionary calculations of white dwarfs of, , and . These models are the result of the full evolutionary calculations of their progenitor stars, starting at the zero age main sequence. Our computations show that Ne sedimentation delays the cooling times of white dwarfs in about 1 Gyr at low luminosities (), affecting the techniques that use white dwarfs to date stellar populations. Neglecting Ne sedimentation when calculating the theoretical white dwarf luminosity function, implies to underestimate the age of the stellar population. Additionally, we studied the consequences of Ne sedimentation on the pulsational properties of ZZ Ceti white dwarfs.

  12. Acerca del moho

    EPA Pesticide Factsheets

    El moho forma parte del medio ambiente natural. Afuera del hogar, el moho juega un papel en la naturaleza al desintegrar materias organicas tales como las hojas que se han caido o los arboles muertos. El moho puede crecer adentro del hogar cuando las espor

  13. Estudio multifrecuencia del medio interestelar cercano a HD 192281

    NASA Astrophysics Data System (ADS)

    Arnal, E. M.; Cappa, C. E.; Cichowolski, S.; Pineault, S.; St-Louis, N.

    Una de las causas que modifica la estructura y dinámica del medio interestelar es la acción que los vientos de las estrellas de gran masa ejercen sobre el mismo. En este trabajo, mediante el uso de datos interferométricos obtenidos en la banda de radio en la transición de λ˜21-cm del hidrógeno neutro y de imágenes de la emisión de continuo en las bandas de 408 y 1420 MHz, de imágenes HIRES del satélite IRAS en 60 y 100μm, y de observaciones de continuo obtenidas con radiotelescopios de disco simple en 2695, 4850 y 8350 MHz se ha realizado un estudio multifrecuencia de los efectos que los vientos estelares de HD 192281, una estrella de tipo espectral O5,Vn((f))p, han tenido sobre el medio interestelar que rodea a la misma.

  14. Hacia el consumo informado de tabaco en México: efecto de las advertencias con pictogramas en población fumadora

    PubMed Central

    Thrasher, James F; Pérez-Hernández, Rosaura; Arillo-Santillán, Edna; Barrientos-Gutiérrez, Inti

    2015-01-01

    Resumen Objetivo Evaluar el efecto de las advertencias sanitarias (AS) con pictogramas en las cajetillas de tabaco en adultos fumadores. Material y métodos Cohorte de fumadores con representatividad poblacional de siete ciudades mexi canas, antes (2010) y después (2011) de la implementación de AS con pictogramas (ASP). Para determinar el cambio en las variables sobre el impacto cognitivo y conductual de las advertencias, se estimaron modelos bivariados y ajustados de ecuaciones de estimación generalizada. En el Segundo levantamiento (2011), se estimaron modelos para determiner los factores que se asocian con el reporte de recordar cada advertencia que había entrado al mercado, además de los factores asociados con el autorreporte del impacto de cada advertencia vigente. Resultados Se observaron incrementos importantes de 2010 a 2011 en los conocimientos sobre los riesgos de fumar, los componentes tóxicos del tabaco y el número telefónico para recibir consejos sobre dejar de fumar. La recordación e impacto de las primeras advertencias con pictogramas parecen ser amplios y equitativos a través de la población fumadora. En comparación con 2010, un mayor nivel de ex fumadores entrevistados en 2011 reportaron que las advertencias habían influido mucho en dejar de fumar (RM=2.44, 95% IC 1.27–4.72). Conclusiones Las AS con pictogramas han logrado un impacto importante en el conocimiento y conducta, información relevante para la población y en tomadores de decisiones. PMID:22689162

  15. US EPA, Pesticide Product Label, PARATHION EHTYL ...

    EPA Pesticide Factsheets

    2011-04-21

    ... ', .. , nIl I' ~~nh~Ii". " .. 1'1. II'" 'flO: T,,, .. fiji[ 10':;\\1';' ""t' I I rAe 1/"'.I ~t~'. ~ ,Nl .. l' .. : Uf.p ... t •• , • 1"" .1('" I.·, l""'iM".'" "r,_ I., .,"II,d, .11'1'1, I,,,.! ...

  16. Espectroscopia del Cometa Halley

    NASA Astrophysics Data System (ADS)

    Naranjo, O.; Fuenmayor, F.; Ferrin, L.; Bulka, P.; Mendoza, C.

    1987-05-01

    Se reportan observaciones espectroscópicas del cometa Halley. Los espectros fueron tomados usando el espectrógrafo del telescopio reflector de 1 metro del Observatorio Nacional de Venezuela. Se utilizó óptica azul, con una red de difracción de 600 lineas/min, obteniéndose una dispersión de 74.2 A/mm y una resolución de 2.5 A, en el rango espectral de 3500 a 6500 A. Seis placas fueron tomadas con emulsión IIa-O y dos con IIa-D. Los tiempos de exposición fueron entre 10 y 150 minutos. El cometa se encontraba entre 0.70 y 1.04 UA del Sol, y entre 1.28 y 0.73 UA de la Tierra. Las emisiones más prominentes en el espectro, son las del CN, C2, y C3. Otras emisiones detectadas corresponden a CH, NH2 y Na. Los espectros muestran un fuerte continuo, indicando un contenido significativo de polvo. Se detectó mayor intensidad del contínuo, en la dirección anti solar, lo cual es evidencia de la cola de polvo.

  17. El efecto de los neutrinos degenerados en la transición de materia nuclear a materia de quarks

    NASA Astrophysics Data System (ADS)

    Lugones, G.; Benvenuto, O. G.

    Se estudia la transicion de materia nuclear a materia de quarks en presencia de un gas degenerado de neutrinos electrónicos y muónicos. Se muestra que la presencia de los neutrinos hace que las densidades de desconfinamiento de quarks sean notablemente mayores que las encontradas en el caso en que no haya neutrinos presentes. Se discuten las posibles consecuencias de este efecto en explosiones de supernova y evolución de proto estrellas de neutrones.

  18. Comportamiento del Helio en estrellas químicamente peculiares

    NASA Astrophysics Data System (ADS)

    Malaroda, S. M.; López García, Z.; Leone, F.; Catalano, F.

    Las estrellas químicamente peculiares (CP) se caracterizan por tener deficiencias y sobreabundancias de algunos elementos químicos de hasta 106 veces la abundancia solar. Además presentan variaciones en las líneas espectrales. Se piensa que ello se debe a que los campos magnéticos presentes en este tipo de estrellas son principalmente dipolares, con un eje de simetría diferente del eje de rotación. La distribución de los elementos sobreabundantes y deficientes no es homogénea sobre la superficie estelar y las variaciones observadas serían una consecuencia directa de la rotación estelar. Entre los elementos con abundancia anómala se encuentra el Helio, cuyas líneas tienen intensidades que no son consistentes con una abundancia normal, que no puede ser determinada del modo usual, o sea, considerando una atmósfera con composición solar. Con el fin de determinar la abundancia de este elemento, se inició un estudio de estrellas anómalas de Helio, Hew y He strong. Además se determinarán las abundancias de otros elementos anómalos como ser el Si, Cr, Mg, Mn y Fe. Las mismas se determinan del modo tradicional, o sea: a) medida de los anchos equivalentes de las líneas de los distintos elementos analizados; b) adopción de la temperatura efectiva, gravedad y abundancia del Helio; c) cálculo del modelo de atmósfera d) comparación con las observaciones y reinicio de un proceso iterativo hasta lograr un acuerdo entre todos los parámetros analizados. Las observaciones se llevaron a cabo en el Complejo Astronómico El Leoncito. Se observaron setenta y ocho estrellas anómalas de Helio. En este momento se está procediendo a calcular las abundancias correspondientes a los distintos elementos químicos. Para ello se hace uso de los modelos de Kurucz, ATLAS9. Los cálculos NLTE de las líneas de Helio se llevan a cabo con el programa MULTI y se compararán con los realizados con el programa WIDTH9 de Kurucz (LTE), con el objeto de resaltar la importancia de

  19. El uso de la neuromodulación para el tratamiento del temblor

    PubMed Central

    Bendersky, Damián; Ajler, Pablo; Yampolsky, Claudio

    2014-01-01

    Introducción: El temblor puede ser un desorden incapacitante y el tratamiento de primera línea para estos pacientes es farmacológico. Sin embargo, este tratamiento puede llevar a una reducción satisfactoria del temblor en sólo el 50% de los pacientes con temblor esencial. La talamotomía era el tratamiento de elección para el temblor refractario al tratamiento médico hasta que comenzó a utilizarse la estimulación cerebral profunda (ECP) del núcleo ventral intermedio (Vim) del tálamo. En la actualidad, raramente se realiza la talamotomía. Métodos: Este artículo es una revisión no sistemática de las indicaciones, resultados, parámetros de programación y técnica quirúrgica de la ECP del Vim para el tratamiento del temblor. Resultados: Aunque los resultados clínicos son similares usando la talamotomía o la ECP del Vim, la primera causa más efectos adversos que la última. Además, la ECP puede ser usada bilateralmente, mientras que la talamotomía tiene un alto riesgo de causar disartria cuando se realiza de ambos lados. La ECP del Vim logró una adecuada mejoría del temblor en varias series de pacientes con temblor causado por temblor esencial, enfermedad de Parkinson o esclerosis múltiple. Además del Vim, hay otros blancos que están siendo usados por varios autores, tales como la zona incerta y las radiaciones prelemniscales. Conclusión: La ECP del Vim es un tratamiento útil para el temblor incapacitante refractario al tratamiento médico. Es esencial realizar una precisa selección de pacientes, así como utilizar una técnica quirúrgica correcta. Aún se desconoce el mejor blanco estereotáctico para el temblor, aunque el Vim es el más usado. PMID:25165613

  20. Estudio del CH interestelar

    NASA Astrophysics Data System (ADS)

    Olano, C.; Lemarchand, G.; Sanz, A. J.; Bava, J. A.

    El objetivo principal de este proyecto consiste en el estudio de la distribución y abundancia del CH en nubes interestelares a través de la observación de las líneas hiperfinas del CH en 3,3 GHz. El CH es una molécula de amplia distribución en el espacio interestelar y una de las pocas especies que han sido observadas tanto con técnicas de radio como ópticas. Desde el punto de vista tecnológico se ha desarrollado un cabezal de receptor que permitirá la realización de observaciones polarimétricas en la frecuencia de 3,3 GHz, con una temperatura del sistema de 60 K y un ancho de banda de 140 MHz, y que será instalado en el foco primario de la antena parabólica del IAR. El cabezal del receptor es capaz de detectar señales polarizadas, separando las componentes de polarización circular derecha e izquierda. Para tal fin el cabezal consta de dos ramas receptoras que amplificarán la señal y la trasladarán a una frecuencia más baja (frecuencia intermedia), permitiendo de esa forma un mejor transporte de la señal a la sala de control para su posterior procesamiento. El receptor además de tener características polarimétricas, podrá ser usado en el continuo y en la línea, utilizando las ventajas observacionales y de procesamiento de señal que actualmente posee el IAR.

  1. Efectos de la radiación UV en la salud

    EPA Pesticide Factsheets

    La reducción de la capa de ozono disminuye la protección natural que ofrece nuestra atmósfera contra la radiación ultravioleta (UV) perjudicial del sol. Esta página web proporciona una descripción general de los principales problemas de salud relacionados

  2. Nevado del Huila, Columbia

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Nevado del Huila Volcano in Colombia is actually a volcanic chain running north to south, capped by a glacier. With peaks ranging in height from 2,600 to 5,780 meters (8,530 to 18,960 feet), Nevado del Huila is a stratovolcano composed of alternating layers of hardened lava, solidified ash, and volcanic rocks. Its first recorded eruption occurred in the mid-sixteenth century. The long-dormant volcano erupted again in mid-April 2007. A few months before the eruption, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of Nevado del Huila, on February 23, 2007. In this image, the bright white area just east of the central summit is ice. Immediately west of the summit are bare rocks, appearing as blue-gray. West of those rocks, white reappears, but this patch of white results from clouds hovering in the nearby valley. In the east, the colors turn to brown (indicating bare rock) and bright green (indicating vegetation). ASTER photographed Nevado del Huila near the end of a long phase of quietude. On April 17, 2007, local authorities recorded seismic activity associated with rock fracturing on the volcano's central summit, according to the ReliefWeb Website. Activity intensified the following day with an eruption and mudflows, forcing thousands of nearby residents to evacuate. As the Associated Press reported, the eruption caused avalanches and floods that wiped away both houses and bridges. It marked the volcano's first recorded eruption since the Spanish colonized the area five centuries earlier. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  3. CONTAMINACIÓN AMBIENTAL, VARIABILIDAD CLIMÁTICA Y CAMBIO CLIMÁTICO: UNA REVISIÓN DEL IMPACTO EN LA SALUD DE LA POBLACIÓN PERUANA

    PubMed Central

    Gonzales, Gustavo F.; Zevallos, Alisson; Gonzales-Castañeda, Cynthia; Nuñez, Denisse; Gastañaga, Carmen; Cabezas, César; Naeher, Luke; Levy, Karen; Steenland, Kyle

    2015-01-01

    RESUMEN El presente artículo es una revisión sobre la contaminación del agua, el aire y el efecto del cambio climático en la salud de la población peruana. Uno de los principales contaminantes del aire es el material particulado menor de 2,5 μ (PM 2,5), en la ciudad de Lima, anualmente 2300 muertes prematuras son atribuibles a este contaminante. Otro problema es la contaminación del aire domiciliario por el uso de cocinas con combustible de biomasa, donde la exposición excesiva a PM 2,5 dentro de las casas es responsable de aproximadamente 3000 muertes prematuras anuales entre adultos, con otro número desconocido de muertes entre niños debido a infecciones respiratorias. La contaminación del agua tiene como principales causas los desagües vertidos directamente a los ríos, minerales (arsénico) de varias fuentes, y fallas de las plantas de tratamiento. En el Perú, el cambio climático puede impactar en la frecuencia y severidad del fenómeno de El Niño oscilación del sur (ENSO) que se ha asociado con un incremento en los casos de enfermedades como cólera, malaria y dengue. El cambio climático incrementa la temperatura y puede extender las áreas afectadas por enfermedades transmitidas por vectores, además de tener efecto en la disponibilidad del agua y en la contaminación del aire. En conclusión, el Perú, pasa por una transición de factores de riesgo ambientales, donde coexisten riesgos tradicionales y modernos, y persisten los problemas infecciosos y crónicos, algunos de los cuales se asocian con problemas de contaminación de agua y de aire. PMID:25418656

  4. Efecto de la difusión y la velocidad en la ionización del átomo de Carbono

    NASA Astrophysics Data System (ADS)

    Rovira, M. G.; Fontenla, J. M.

    The equations of statistical equilibrium for all ionization states of the atom are solved. The effects of diffusion and center of mass velocity are included. In order to estimate the modifications of the ionization curves, they were applied to the Carbon atom. To solve these equations, solar prominences' models obtained in a previous paper were adopted. They were extended to reach a temperature of 1.5 × 106 K and the complete model of the prominence was calculated. Ionization curves for different values of velocity, diffusion and medium models were obtained. The different models represent structures with different densities. Considerable modifications due to these effects are found.

  5. Case Study: del Amo Bioventing

    EPA Science Inventory

    The attached presentation discusses the fundamentals of bioventing in the vadose zone. The basics of bioventing are presented. The experience to date with the del Amo Superfund Site is presented as a case study.

  6. RASTREO DEL CANCER COLORRECTAL CONOCIMIENTO Y ACTITUD DE LA POBLACION

    PubMed Central

    CASAL, ENRIQUE R.; VELAZQUEZ, ELIZABETH N.; MEJIA, RAUL M.; CUNEO, ALDO; PEREZ-STABLE, ELISEO J.

    2014-01-01

    Resumen El rastreo de cáncer colorrectal (CCR) cuenta con fuertes evidencias en su favor. Datos preliminares indican que a pesar de ello no se lleva a cabo con la frecuencia adecuada. Se intenta aquí determinar, dentro de un Sistema de Salud que cuenta con los recursos necesarios, los elementos que facilitan o generan barreras para concretar esta práctica preventiva, cuántos individuos lo ponen en práctica y qué predice esta conducta. Se realizó una encuesta telefónica a los afiliados de una Obra Social de empleados de la Universidad de Buenos Aires, de los que 132 completaron el cuestionario (tasa de respuesta 70%). Los elementos considerados facilitadores del rastreo obtuvieron respuestas afirmativas en el 64 a 97%, mientras que los que definían barreras un 11 a 27%. En este último grupo, una categoría diferenciada la constituía el miedo a los efectos adversos: 39%, y el sentimiento de vergüenza relacionado con los procedimientos: 30%. Un 33% de los encuestados tenían hecho un método de rastreo, mayoritariamente de sangre oculta (27), sigmoideoscopía (11) y colonoscopía (20). Una mayoría afirmó que “se haría el procedimiento si el médico se lo recomendara” (95%), o “no se lo haría excepto que su médico se lo aconseje” (87%). Contestar afirmativamente que “los médicos hacen lo mejor para los pacientes” se asoció con haberse hecho un método de rastreo de CCR, OR 1.55 (IC 95%: 1.02-2.37) p: 0.04. El grupo de individuos estudiado parece bien predispuesto para el rastreo del CCR, la recomendación médica sería aquí un determinante prominente para ponerlo en práctica. PMID:19414294

  7. El libro del Relogio del Palacio de las Horas

    NASA Astrophysics Data System (ADS)

    Morales, J. D.

    2009-08-01

    This paper resume the investigation entitled ``El libro del Relogio del Palacio de las Horas''. That consist in an edition of the original text of the book of the Clock of the Palace of the Hours from the Books of the knowledge of Astronomy of Alfonso X (Manuscript 156, Complutense University). And a description of the astronomical functionality of the Clock of the Palace of the Hours. It includes a geometric description of the positional astronomy on which the operation of the Palace is based.

  8. Modelado del efecto de manchas frías en el perfil del tránsito de proto-planetas en estrellas jóvenes de tipo WTTS

    NASA Astrophysics Data System (ADS)

    Lovos, F. V.; Gómez, M.; Ahumada, J. A.; Petrucci, R.; Jofré, J. E.

    2016-08-01

    Weak Emission T Tauri stars (WTTS) are pre-main sequence stars with ages of 10 10 yr, stage at which circumstellar disk material is being used to form planets. This class of young stars shows photometric variations that correlate with the rotational period and are attributed to magnetic cold spots. To model the planet-spot-star system we use the soap-t code, that allows the construction of light curves including planetary transits and spots at the same time. We focus on the deformations that the spot introduces to the transit profile for the case of a proto-planet with 2 Jupiter radii. We consider spotted areas typical for WTTS covering from to of the visible stellar disk, with temperatures of 500 and 1400 K less than that of the stellar surface. The results show the modulation of the stellar brightness caused by the spot. In particular, this modulation increases the depth of the transit. Furthermore, when the spot is eclipsed by the proto-planet, a rebrightening is observed as the planet blocks a zone cooler than the rest of the stellar surface.

  9. 40 CFR 180.122 - Parathion; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., undelinted seed 0.75 12/31/05 Rapeseed, seed 0.2 12/31/05 Sorghum, forage 3.0 12/31/05 Sorghum, grain, grain 0.1 12/31/05 Sorghum, grain, stover 3.0 12/31/05 Soybean 0.1 12/31/05 Soybean, hay 1.0...

  10. 40 CFR 180.121 - Methyl parathion; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 1.0 None Bean, dry, seed 1.0 1/24/09 Beet, sugar, roots 0.1 1/24/09 Beet, sugar, tops 0.1 1/24/09....2 None Sweet potato, roots 0.1 None Walnut 0.1 None Wheat 1.0 None (b) Section 18 emergency... Beet, garden, tops 1 Broccoli 1 Brussels sprouts 1 Carrot, roots 1 Cauliflower 1 Celery 1 Cherry...

  11. 40 CFR 180.121 - Methyl parathion; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., vines 1.0 12/31/13 Potato 0.1 12/31/13 Rapeseed, seed 0.2 12/31/13 Rice, grain 1.0 12/31/13 Soybean, hay 1.0 12/31/13 Soybean, seed 0.1 12/31/13 Sunflower, seed 0.2 12/31/13 Sweet potato, roots 0.1 12/31... Corn, sweet, forage 1.0 12/31/13 Corn, sweet, kernel plus cob with husks removed 1.0 12/31/13...

  12. 40 CFR 180.121 - Methyl parathion; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., vines 1.0 12/31/13 Potato 0.1 12/31/13 Rapeseed, seed 0.2 12/31/13 Rice, grain 1.0 12/31/13 Soybean, hay 1.0 12/31/13 Soybean, seed 0.1 12/31/13 Sunflower, seed 0.2 12/31/13 Sweet potato, roots 0.1 12/31... Corn, sweet, forage 1.0 12/31/13 Corn, sweet, kernel plus cob with husks removed 1.0 12/31/13...

  13. 40 CFR 180.121 - Methyl parathion; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., vines 1.0 12/31/13 Potato 0.1 12/31/13 Rapeseed, seed 0.2 12/31/13 Rice, grain 1.0 12/31/13 Soybean, hay 1.0 12/31/13 Soybean, seed 0.1 12/31/13 Sunflower, seed 0.2 12/31/13 Sweet potato, roots 0.1 12/31... Corn, sweet, forage 1.0 12/31/13 Corn, sweet, kernel plus cob with husks removed 1.0 12/31/13...

  14. 40 CFR 180.121 - Methyl parathion; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....2 None Sweet potato, roots 0.1 None Walnut 0.1 None Wheat 1.0 None (b) Section 18 emergency... Corn, sweet, forage 1.0 None Corn, sweet, kernel plus cob with husks removed 1.0 None Cotton... Peanut 1.0 None Pea, dry, seed 1.0 1/24/09 Pea, field, vines 1.0 None Pecan 0.1 1/24/09 Potato 0.1...

  15. US EPA, Pesticide Product Label, RIVERSIDE PARATHION 4 ...

    EPA Pesticide Factsheets

    2011-04-21

    ... OF CORT4CT: I.-ediately flu.h eye. or .kia with pleat, of w.ter for .t le •• t 15 .inute. ... of pol.oi1 '1'.: '.c" •••• oaltl ••• cr .. , •• ka •••• blurr.d .i.ioa. ...

  16. 78 FR 60720 - Methyl Parathion; Removal of Expired Tolerances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-02

    ..., entitled ``Protection of Children from Environmental Health Risks and Safety Risks'' (62 FR 19885, April 23... determined that this action will not have a substantial direct effect ] on States, on the relationship... ensure ``meaningful and timely input by State and local officials in the development of...

  17. Parathion causes secondary poisoning in a laughing gull breeding colony

    USGS Publications Warehouse

    White, D.H.; King, K.A.; Mitchell, C.A.; Hill, E.F.; Lamont, T.G.

    1979-01-01

    Use of organophosphate insecticides as replacements for the more persistent organochlorine compounds has increased dramatically in recent years. Organophosphates are desirable for field application because they break down rapidly in the environment and do not persist in animal tissues (Stickel 1974). Nevertheless, certain organophosphates are extremely toxic to wildlife for short periods after application and have caused widespread mortality among exposed animals (Mills 1973, Stickel 1974, 1975, Mendelssohn 1977, and Zinkl et al. 1978).

  18. 40 CFR 180.122 - Parathion; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... agricultural commodities: Commodity Parts per million Expiration/Revocation Date Alfalfa, forage 1.25...

  19. Determinación del perfil instrumental del EBASIM

    NASA Astrophysics Data System (ADS)

    Nieva, M. F.; Rodriguez, M. V.; Pintado, O. I.

    Se calcula el perfil instrumental para el telescopio de 2,15m del CASLEO con EBASIM. Para ello se usaron flats de cielo y el espectro solar FTS de Kurucz. El método, que se puede utilizar para otras configuraciones instrumentales, es convolucionar ambos espectros para obtener los coeficientes de corrección.

  20. Mal del pinto in Mexico*

    PubMed Central

    Marquez, Francisco; Rein, Charles R.; Arias, Oswaldo

    1955-01-01

    This report deals with the geographical distribution, prevalence, epidemiology, etiology, serological, clinical, and histopathological features, and treatment of mal del pinto, or pinta, in Mexico. Repository penicillin preparations (PAM and Panbiotic) have been found highly effective in the treatment of this endemic, non-venereal treponematosis. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7FIG. 8 PMID:13260889

  1. 33 CFR 80.1118 - Marina Del Rey, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Marina Del Rey, CA. 80.1118... NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1118 Marina Del Rey, CA. (a) A line drawn from Marina Del Rey Breakwater South Light 1 to Marina Del Rey Light 4. (b) A line drawn from Marina Del...

  2. Calidad del aire interior en las escuelas

    EPA Pesticide Factsheets

    EPA ha desarrollado el Programa de Herramientas de Calidad del Aire Interior para las Escuelas para reducir la exposición a los contaminantes ambientales en las mismas a través de la adopción voluntaria de las prácticas para manejar la calidad del aire int

  3. Produccion Gaseosa del Cometa Halley: Erupciones Y Fotodisociacion del Radical OH

    NASA Astrophysics Data System (ADS)

    Silva, A. M.; Mirabel, I. F.

    1990-11-01

    RESUMEN:En este trabajo informamos la detecci6n de 20 erupciones en la li'nea de =18cm (1667MHz) del radical OH en el Cometa Halley.Las observaciones incluyen todos los monitoreos existentes y se extienden desde 120 dias antes del perihelio hasta 90 dias despues.Se detectan bruscos crecimientos en el flujo medido,hasta un factor 1O,seguidos por decaimientos lentos asociados con la fotodisociaci6n del OH. Se obtuvieron valores para el tiempo de vida fotoquimico del OH y del H2O basandose en el modelo desarrollado previamente por Silva(1988). Esos tiempos de vida estan de acuerdo con predicciones teoricas y con las observaciones en el Ultravioleta, y los resultados, los que son fuertemente dependientes de la velocidad heliocentrica del Coineta (variando hasta un factor 6), han sido calculados para varios rangos de velocidad entre +28 y -28 km/seg. Key wo'L :

  4. Neurobiología del autismo y TDAH mediante técnicas de neuroimagen: divergencias y convergencias

    PubMed Central

    Proal, Erika; Olvera, Jorge González; Blancas, Aurea S.; Chalita, Pablo J.; Castellanos, F. Xavier

    2013-01-01

    En el área clínica algunos síntomas del trastorno por déficit de atención e hiperactividad (TDAH), se presentan en los pacientes con trastorno del espectro autista (TEA). Se ha demostrado que existen alteraciones en circuitos cerebrales que impactan en fallas cognitivas y de comportamiento específicas de cada uno de estos trastornos. Sin embargo, han sido poco estudiados los correlatos cerebrales que hay detrás tanto de las similitudes como de las diferencias sintomatológicas. En la presente revisión se analizaron los estudios meta-analíticos existentes estructurales y funcionales en TDAH y TEA. Por un lado, se observaron convergencias en circuitos como el dorsal atencional, de funciones ejecutivas, visual, somatomotor y circuito de activación por defecto. Estas similitudes posiblemente explican las manifestaciones comórbidas entre los trastornos como la falla en la integración de información, motricidad fina y procesos atencionales específicos. Por otro lado, específicamente en el TDAH se observan déficits en el circuito de recompensa y ventral atencional, sistemas involucrados en la medición de efectos de reforzamiento y monitoreo atencional. En TEA los circuitos más afectados fueron los implicados en procesos de cognición social y lenguaje. En conclusión, existen correlatos neuronales en TEA que explican las manifestaciones clínicas tanto convergentes como divergentes presentes en TDAH. PMID:23897144

  5. Intertextual Sexual Politics: Illness and Desire in Enrique Gomez Carrillo's "Del amor", "del dolor y del vicio" and Aurora Caceres's "La rosa muerta"

    ERIC Educational Resources Information Center

    LaGreca, Nancy

    2012-01-01

    This study explores the intertextuality between Aurora Caceres's "La rosa muerta" (1914) and the novel "Del amor, del dolor y del vicio" (1898) by her ex-husband, Enrique Gomez Carrillo. Caceres strategically mentions Gomez Carrillo's novel in "La rosa muerta" to invite a reading of her work in dialogue with his. Both narratives follow the sexual…

  6. Calidad de Imagen del Telescopio UNAM212

    NASA Astrophysics Data System (ADS)

    Cobos, F. J.; Teiada de Vargas, C.

    1987-05-01

    El telescopio UNAM2l2, del Observatorio Astronómico Nacional, situado en la Sierra de San Pedro Mártir (Baja California, México), cumplira en un futuro muy cercano siete años de uso para fines de investigación astronómica. Aunque en este tiempo no se ha efectuado un estudio sistemático acerca de su comportamiento óptico y de los factores que influyen en la calidad de las imágenes, se han realizado pruebas diversas, estudios parciales y reuniones especificas, cuyos resultados no siempre se han difundido ampliamente y generalmente no se han presentado por escrito. Es por ello que hemos creido necesario intentar una recopilación de la información existente para poder con ella establecer un diagnóstjco que, aunque no sea definitivo, sirva de base para futuros trabajos tendientes a optimizar el comportamiento óptico del telescopio. Es evidente que un buen número de las conclusiones que se presentan son resultado del trabajo de muchas personas ó de esfuerzos colectivos. Asimismo, hemos tratado de localizar información bibliográfica que pueda ser de utilidad. Nuestro objetivo primordial ha consistido en centrarnos en la óptica del telescopio y su calidad, pero también se han considerado otros aspectos que puedan afectar las imágenes obtenidas tales como: celda del primario, `seeing' local y externo, flexiones posibles en la estructura mecánica del telescopio, etc.

  7. Visiting the Gödel universe.

    PubMed

    Grave, Frank; Buser, Michael

    2008-01-01

    Visualization of general relativity illustrates aspects of Einstein's insights into the curved nature of space and time to the expert as well as the layperson. One of the most interesting models which came up with Einstein's theory was developed by Kurt Gödel in 1949. The Gödel universe is a valid solution of Einstein's field equations, making it a possible physical description of our universe. It offers remarkable features like the existence of an optical horizon beyond which time travel is possible. Although we know that our universe is not a Gödel universe, it is interesting to visualize physical aspects of a world model resulting from a theory which is highly confirmed in scientific history. Standard techniques to adopt an egocentric point of view in a relativistic world model have shortcomings with respect to the time needed to render an image as well as difficulties in applying a direct illumination model. In this paper we want to face both issues to reduce the gap between common visualization standards and relativistic visualization. We will introduce two techniques to speed up recalculation of images by means of preprocessing and lookup tables and to increase image quality through a special optimization applicable to the Gödel universe. The first technique allows the physicist to understand the different effects of general relativity faster and better by generating images from existing datasets interactively. By using the intrinsic symmetries of Gödel's spacetime which are expressed by the Killing vector field, we are able to reduce the necessary calculations to simple cases using the second technique. This even makes it feasible to account for a direct illumination model during the rendering process. Although the presented methods are applied to Gödel's universe, they can also be extended to other manifolds, for example light propagation in moving dielectric media. Therefore, other areas of research can benefit from these generic improvements.

  8. La Exploracion Del Contexto Social y Sus Efectos en el Programa de Espanol en Mexico Rural. (Exploring the Social Context Affecting a Pre-School Spanish Program in Rural Mexico).

    ERIC Educational Resources Information Center

    Finegold, Lynda

    A major stumbling block for the implementation of Mexico's Global Development Plan has been the country's large rural population of Indians. One government strategy to integrate this sector into the mainstream of society has been to teach Spanish, the official language, as a second language, while at the same time fostering ethnic pride. The…

  9. Radio-Observaciones del OH EN la Coma del Cometa Halley Desde EL Hemisferio Sur

    NASA Astrophysics Data System (ADS)

    Silva, A. M.; Bajaja, E.; Morras, R.; Cersosimo, J. C.; Martin, M. C.; Arnal, E. M.; Poppel, W. G. L.; Colomb, F. R.; Mazzaro, J.; Olalde, J. C.; Boriakoff, V.; Mirabel, I. F.

    1987-05-01

    Se utilizó una antena de 30 metros del Instituto Argentino de Radioastronomía para observaciones diarias Cf ebrero a abril de 1986) de la transición en 1667 MHz ( λ = 18 cm) del OH en la coma del cometa Halley. De las observaciones realizadas se concluye: 1) El número promedio de moléculas de OH en la coma durante 37 días de observación fue de (8.9±3.5)x1034 moléculas, lo que implica una tasa de producción promedio de OH de 1.8x1029 moléculas seg-1 y consecuentemente una pérdida de masa promedio de 17±6 toneladas seg-1 . Este valor está de acuerdo con las mediciones realizadas por las sondas Vega y Giotto. 2) El monitoreo desde el lAR revela la existencia de variaciones bruscas en los flujos de absorción del OH. Estas variaciones son consistentes con los modelos que representan la producción gaseosa a partir de ejecciones y/o desprendimientos discretos de materia congelada del núcleo. 3) Las variaciones en la densidad de flujo son consistentes con las estimaciones de los tiem- pos de vida medios del H2O y del OH en presencia del campo de radiación solar. 4) Se encuentra una correlación entre la intensidad del flujo absorbido y anisotropías en Ia dinamica de la coma.

  10. Manual del McVCO 1999

    USGS Publications Warehouse

    McChesney, P.J.

    1999-01-01

    El McVCO es un generador de frecuencias basado en un microcontrolador que reemplaza al oscilador controlado por voltaje (VCO) utilizado en telemetría analógica de datos sísmicas. Acepta señales de baja potencia desde un sismómetro y produce una señal subportadora modulada en frecuencia adecuada para enlaces telefónicos o vía radio a un lugar remoto de recolección de datos. La frecuencia de la subportadora y la ganancia pueden ser seleccionadas mediante un interruptor. Tiene la opción de poder operar con dos canales para la observación con ganancia alta y baja. El McVCO fue diseñado con el propósito de mejorar la telemetría analógica de las señales dentro de la Pacific Northwest Seismograph Network (PNSN) (Red Sismográfica del Noroeste del Pacífico). Su desarrollo recibió el respaldo del Programa de Geofísica de la Universidad de Washington y del "Volcano Hazards and Earthquake Hazards programs of the United States Geological Survey (USGS) (Programa de Investigaciones de Riesgos Volcánicos y Programa de Investigaciones de Riesgos Sísmicos de los EEUU). Cientos de instrumentos se han construido e instalado. Además de utilizarlo el PNSN, el McVCO es usado por el Observatorio Vulcanológico de Alaska para monitorear los volcanes aleutianos y por el USGS Volcano Disaster Assistance Program (Programa de Ayuda en las Catástrofes Volcánicas del USGS) para responder a crisis volcánicas en otros países. Este manual cubre el funcionamiento del McVCO, es una referencia técnica para aquellos que necesitan saber con más detalle cómo funciona el McVCO, y cubre una serie de temas que requieren un trato explícito o que derivan del despliegue del instrumento.

  11. [Revista de Gastroenterologia del Peru: 25 years].

    PubMed

    Celestino Fernández, Alvaro

    2005-01-01

    In this article is described in a very summarized form the history of the Revista de Gastroenterología del Perú (RGP) that dates from the same origins of the Sociedad de Gastroenterología del Perú, when based in October 30 of 1952 already glimpse the presence of the RGP as the official organ for the publication for studies of doctors of the society or foreign guests. We spent 29 years, and this idea becomes reality; and today the RGP turns to their XXV anniversary. The RGP, to locate itself as the Peruvian medical publication best reputation.

  12. 33 CFR 80.1118 - Marina Del Rey, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Marina Del Rey, CA. 80.1118 Section 80.1118 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1118 Marina Del Rey, CA. (a) A line drawn from Marina Del Rey Breakwater South Light...

  13. Hopeful (protein InDel) monsters?

    PubMed

    Tóth-Petróczy, Agnes; Tawfik, Dan S

    2014-06-10

    In this issue of Structure, Arpino and colleagues describe in atomic detail how a protein stomachs a deletion within a helix, an event that rarely occurs in nature or in the lab. Can insertions and deletions (InDels) trigger dramatic structural transitions?

  14. Regulación del flujo sanguíneo uterino. I. Funciones de estrógeno y receptores estrogénicos α/β en el endotelio vascular uterino durante el embarazo

    PubMed Central

    Mayra, Pastore R.; Rosalina, Villalón L.; López, Gladys; Iruretagoyena, Jesús; Magness, Ronald

    2015-01-01

    Resumen El estrógeno y los receptores estrogénicos clásicos (REs), RE-α y RE-β, han demostrado ser parcialmente responsable por las adaptaciones endoteliales uterinas durante el embarazo al corto y largo plazo. Las diferencias moleculares y estructurales, junto con los diferentes efectos causados por estos receptores en las células y los tejidos, sugieren que su función varía dependiendo de la manera en la cual el estrógeno se comunica con sus receptores. En ésta revisión bibliográfica se discuten la función del estrógeno y sus receptores clásicos en las adaptaciones cardiovasculares durante el embarazo y la expresión de los Res in vivo e in vitro en el endotelio de la arteria uterina durante el ciclo ovárico y el embarazo, a la vez comparado con la expresión en endotelio arterial de tejidos reproductivos y no reproductivos. Estos temas integran el conocimiento actual de este amplio campo científico con interpretaciones e hipótesis diversas relacionadas con los efectos estrogénicos mediados bien sea por uno o los dos REs. Esta revisión también incluye la relación con las adaptaciones vasodilatadoras y angiogénicas requeridas para modular el dramático incremento fisiológico en la perfusión útero-placentaria observada durante un embarazo normal. PMID:26113750

  15. Del Norte means north to recycling

    SciTech Connect

    Aquino, J.T.

    1998-06-01

    Del Norte Regional Recycling and Transfer Station is owned by the city of Oxnard, California and operated by BLT Enterprises, Inc. The Del Norte facility--located in southwestern Ventura County about an hour northwest of Los Angeles--processes polyethylene terephthalate (PET) and high-density polyethylene (HDPE) plastic containers, aluminum, steel, glass, old corrugated containers (OCC), newspapers, computer printout paper, white and colored ledger paper, coated book, supermix paper, telephone books, and old magazines. According to the company, there has been virtually no community opposition to the site. The facility has few neighbors, and those are agricultural. To keep the community relationship strong, the facility`s design and location all but eliminated odor and noise complaints. The building was designed against the prevailing wind pattern, and BLT processes odorous material fast. A misting system installed for dust suppression also can be used with a solution for odor control should the need arise.

  16. Procesamiento Digital de Imagenes del Cometa Halley

    NASA Astrophysics Data System (ADS)

    Ferrin, L.; Fuenmayor, F.; Naranjo, O.; Bulka, P.; Mendoza, C.

    1987-05-01

    Se reportan observaciones fotográficas del cometa Halley, obtenidas con los telescopios Schmidt de 1-m del CIDA, y de 35 cms de la ULA. Se hicieron exposiciones desde 2 segundos a 30 minutos y se utilizaron emulsiones IIa-O, 103a-F, y 103a-D, guladas manualmente 0 automaticámente. Las imágenes fueron digitalizadas con el microdensitómetro PDS, y procesadas con el sistema HACIENDA del CCIBM. Se experimentó con la Transformada de Fourier en dos dimensiones, y con la aplicación de filtros de paso alto y bajo. Se encontró que el metodo de "autocorrelación" es el mejor para separar "la vegetación" de "la montaña". Se aplicaron diversas técnicas a fin de cubrir ambos extremos: a) enfatizar detalles débiles en la cola, y b) penetrar en las regiones más intensas de la coma. Se lograron ambos objetivos. Detalles en la cola permitieron determinar velocidades de propagación de unos 50 a 90 kms/ seg. Se pudieron detectar no menos de tres perturbaciones en "Y", y una en 5? Co de Cisne). Se cree que las primeras están asociadas a eventos de desconexión. Se puede separar la cola de gas de la de polvo. Las fotos de color permiten enfatizar diferentes regiones espectrales con mayor claridad aún. El "balance" del color puede ser hecho con la computadora.

  17. del, Einstein, Mach, Gamow, and Lanczos: Gödel's remarkable excursion into cosmology

    NASA Astrophysics Data System (ADS)

    Rindler, Wolfgang

    2009-06-01

    This article is an expanded version of a talk given at the International Symposium Celebrating the 100th Birthday of Kurt Gödel (Vienna, 2006). It seeks to trace the path which led this preeminent mathematical logician to discover one of the famous results of General Relativity, the rotating Gödel Universe. This universe has some remarkable properties, which gave the philosophers plenty to worry about. It allows a person to travel into his own past, with all the ensuing causal paradoxes; it allows no unique temporal ordering of events; and though Gödel's Universe is rigid and infinite, the Foucault pendulum planes everywhere in it rotate in unison, a clear affront to adherents of Mach's Principle. We also discuss some lesser known precursors in the field, who just missed discovering Gödel's universe. While the article gives all the necessary derivations in simplified form (for example, of the metric and its geodesics), much of it should be accessible to the general reader, who can simply skip most of the mathematics. [Reprinted, with permission, from Kurt Gödel and the Foundations of Mathematics: Horizons of Truth, edited by Matthias Baaz, Christos H. Papadimitriou, Dana S. Scott, Hilary Putnam, and Charles L. Harper, Jr. (Cambridge U. P., New York, 2009).

  18. IN VITRO EFFECTS OF CHLORPYRIFOS, PARATHION, METHYL PARATHION AND THEIR OXONS ON CARDIAC MUSCARINIC RECEPTOR BINDING IN NEONATAL AND ADULT RATS. (R825811)

    EPA Science Inventory

    Organophosphorus insecticides elicit toxicity by inhibiting acetylcholinesterase. Young animals are generally more sensitive than adults to these toxicants. A number of studies reported that some organophosphorus agents also bind directly to muscarinic receptors, in particular...

  19. Morphology, geology and geochemistry of the "Salar del Gran Bajo del Gualicho" (Rio Negro, Argentina)

    USGS Publications Warehouse

    Angelucci, A.; Barbieri, M.; Brodtkorb, A.; Ciccacci, S.; Civitelli, G.; De Barrio, R.; Di, Filippo M.; Fredi, P.; Friedman, I.; Lombardi, S.; Schalamuk, A.I.; Toro, B.

    1996-01-01

    A multidisciplinary study of the Gran Bajo del Gualicho area (Rio Negro - Argentina) was carried out; the aim was to delineate its geological and geomorphological evolution and to estabilish the genesis of salts filling the depression. Climatic conditions were analized first to individuate their role in the present morphogenetic processes; moreover the main morphological features of present landscape were examined as well as the stratigraphy of the outcropping formations, and of the Gran Bajo del Gualicho Formation in particular. Finally, a possible geomorphological evolution of the studied area was traced. Geophysical analyses allowed to estabilish that the paleosurface shaped on the crystalline basement is strongly uneven and shows evidence of the strong tectonic phases it underwent. The result of isotope analyses confirmed that the salt deposits on the Gran Bajo del Gualicho bottom were produced by fresh water evaporation, while strontium isotope ratio suggested that such waters were responsible for solubilization of more ancient evaporitic deposits.

  20. Kurt Gödels Brünner Verwandte

    NASA Astrophysics Data System (ADS)

    Müller, Dora

    2007-11-01

    The author of this memoir Dora Müller (born 1920) belongs - as well as Kurt Gödel-to the German minority playing an important role in the past life of Brno. The marriage of his son included her among the Gödels collaterals. She was chemist, but also pianist, historician, participant of antinacist movement and iniciator of Czech-German understanding after war. Following her personal experiences, remembrances of Gödels relatives and documental materials, she evokes the atmosphere of broader family milieu of Kurt Gödel.

  1. An evening at "La Clinica del Pueblo".

    PubMed

    Shefsky, M L

    1986-01-01

    This article describes a typical evening at the Clinica del Pueblo in the Hispanic neighborhood of Adams-Morgan in Washington, D.c. The Clinical del Pueblo began operating in 1983 in response to the urgen medical needs of Central American refugees arriving in the Washington D.c. area. The refugees bring with them severe trauma, fear, and health problems caused by the civil was and exacerbated by inadequate or non-existant health services. Approximately 80,000 Salvadoran refugees live in the area. They do not receive adequate health care for 3 reasons. 1) Because the US goverment is unwilling to recognize them as true refugees, they live with the constant threat of deportatin back to the violence from which they have fled. 2) Refugees lack the ability to pay for private care. 3) Langauage and culture create frightening barriers to health care for the refugees. For those who do seek care, these barriers can lead to the inadequate or incomplete diagnoses and poor compliance and follow-up. Plenty International and the Central American Refugee Center responded to these problems by organizing a free clinic to provide not only medical care but also a training course for volunteers. The director of the clinic organizes the course, the classes are taught by a variety of people including the clinic's volunteer physicians, nurses, and public health educators as well as graduates of previus training courses and people from the wider community. The services of the clinic reach only a small portion of the population in need. However, the fact that free medical services are now available to some Central American refugees make the Clinica del Pueblo an important program.

  2. Huave de San Mateo del Mar, Oaxaca (Huave of San Mateo del Mar, Oaxaca).

    ERIC Educational Resources Information Center

    Mexico Coll. (Mexico City)

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Huave, an indigenous language of Mexico spoken in San Mateo del Mar, in the state of Oaxaca. The objective of collecting such a representative sampling of…

  3. Pastoral del Nino: Bringing the Abundant Life to Paraguayan Children

    ERIC Educational Resources Information Center

    Austin, Ann Berghout; Aquino, Cyle; Burro, Elizabeth

    2007-01-01

    Pastoral del Nino is transforming children's lives in rural Paraguay. Part of Pastoral Social (Catholic Social Services), Pastoral del Nino's primary focus is to bring "vida en abundancia" (the abundant life) to families by ensuring that mothers survive childbirth and children reach their first birthdays. In addition, the organization…

  4. 33 CFR 110.111 - Marina del Rey Harbor, Calif.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Marina del Rey Harbor, Calif. 110.111 Section 110.111 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.111 Marina del Rey Harbor, Calif. An area...

  5. [Strengths and future of the Revista Médica del Instituto Mexicano del Seguro Social].

    PubMed

    Fajardo-Dolci, Germán

    2014-01-01

    The journals of medicine arose as a communication tool more than 200 years ago. At the beginning, their nature was local; later, their aim was to spread medical information along the nation; and, finally, they sought to reach the world distribution. The Revista Médica del Instituto Mexicano del Seguro Social was published for the first time 52 years ago, and it has walked its way from local to international distribution. This journal has 23 000 subscribers, it is included in Medline and it reached a 0.112 SCImago Journal Rank in 2012. Its website receives around 200 000 visits monthly and 45 % are foreign visits. In the future, the peer review system is going to be strengthened, and the journal is going to offer audio, video, and applications to reinforce interactive participation between authors, readers in order to reach modernity and draw young new attention.

  6. Illuminating water and life: Emilio Del Giudice.

    PubMed

    Ho, Mae-Wan

    2015-01-01

    The quantum electrodynamics theory of water put forward by Del Giudice and colleagues provides a useful foundation for a new science of water for life. The interaction of light with liquid water generates quantum coherent domains in which the water molecules oscillate between the ground state and an excited state close to the ionizing potential of water. This produces a plasma of almost free electrons favoring redox reactions, the basis of energy metabolism in living organisms. Coherent domains stabilized by surfaces, such as membranes and macromolecules, provide the excited interfacial water that enables photosynthesis to take place, on which most of life on Earth depends. Excited water is the source of superconducting protons for rapid intercommunication within the body. Coherent domains can also trap electromagnetic frequencies from the environment to orchestrate and activate specific biochemical reactions through resonance, a mechanism for the most precise regulation of gene function.

  7. Wave maps from Gödel's universe

    NASA Astrophysics Data System (ADS)

    Barletta, Elisabetta; Dragomir, Sorin; Magliaro, Marco

    2014-10-01

    Using a result by Koch (1988 Trans. Am. Math. Soc. 307 827-41) we realize Gödel's universe G_{α }^{4}=({{{R}}^{4}},{{g}_{α}}) as the total space of a principal {R}-bundle over a strictly pseudo-convex CR manifold M3 and exploit the analogy between {{g}_{Yalpha;}} and Fefferman's metric {{F}_{θ}} (Fefferman 1976 Ann. Math. 103 395-416 104 393-4) to show that for any {R}-invariant wave map Φ of G_{α}^{4} into a Riemannian manifold N, the corresponding base map φ :{{M}^{3}}\\to N is subelliptic harmonic, with respect to a canonical choice of contact form θ on M3. We show that the subelliptic Jacobi operator J_{b}^{φ} of ϕ has a discrete Dirichlet spectrum on any bounded domain D\\subset {{M}^{3}} supporting the Poincaré inequality on \\mathop{W}\\limits^{\\circ }{}_{H}^{1,2}(D,{{φ}^{-1}}TN) and Kondrakov compactness, i.e. compactness of the embedding \\mathop{W}\\limits^{\\circ }{}_{H}^{1,2}(D,{{φ }^{-1}}TN)\\hookrightarrow {{L}^{2}}(D,{{φ}^{-1}}TN). We exhibit an explicit solution π :G_{α}^{4}\\to {{M}^{3}} to the wave map system on G_{α}^{4}, of index in{{d}^{Ω}}(π)\\geqslant 1 for any bounded domain Ω \\subset G_{α}^{4}. Mounoud's distance (Mounoud 2001 Differ. Geom. Appl. 15 47-57) d_{{{G}_{0}}, Ω }^{∞}({{g}_{α }}, {{F}_{θ}}) is bounded below by a constant depending only on the rotation frequency of Gödel's universe, thus giving a measure of the bias of {{g}_{α}} from being Fefferman like in the region Ω \\subset {{{R}}^{4}}.

  8. Estudio teórico del CO2. Orbitales de valencia y del ``core''

    NASA Astrophysics Data System (ADS)

    Olalla Gutiérrez, E.

    Hemos calculado las intensidades de las transiciones E1 a los miembros de las series de Rydberg con origen en los orbitales ``no enlazantes'' del dióxido de carbono, especie de conocida relevancia atmosférica. Se han computado, asimismo, los continuos de fotoionización correspondientes a los distintos canales de ionización, representándolos como densidad espectral de fuerza de oscilador frente a la energía del fotón incidente; mostramos los resultados df/dE para la fotoionización total de esta especie en el intervalo 15-60 eV. Todos los cálculos se han llevado a cabo mediante la formulación Molecular del Método de los Orbitales de Defecto Cuántico, MQDO [1,2]. La calidad de los resultados que presentamos se ha evaluado en base a la comparación con los datos, tanto experimentales como teóricos, disponibles en la bibliografía. El acuerdo encontrado es altamente satisfactorio

  9. [La Medicina del Lavoro: 100 volumes].

    PubMed

    Zocchetti, C

    2009-01-01

    With these pages La Medicina del Lavoro starts its 100th volume, so we have yet another historical occasion to celebrate the oldest occupational health journal in the world that is still publishing. Over the last few years we have had many occasions to celebrate, for example several anniversaries of the Journal (the 80th volume in 1989, 90 years in 1992, 100 years in 2001); the centenary of the foundation of the Clinica del Lavoro "Luigi Devoto" of Milan in 2001; the celebration of the 300 years' anniversary of the publication of De Morbis Artificum Diatriba by Bernardino Ramazzini, and we obviously hope to continue for many years to come in this positive outlook. One hundred volumes makes for a very large collection, with the highs and lows ofthe Journal's history (here we mean the variations in number of pages and physical size of the Journal). It is thanks to the Editors-in-chief(there have been very few so we can cite them all: Luigi Devoto, 1901-1936; Luigi Preti, 1936-1941; Enrico Vigliani, 1943-1992; e Vito Foà, 1992 to the present); the contributors who in various ways and with varying degrees of commitment but always with an exceptional personal participation, that it has been possible to reach 100 volumes, starting with C. Moreschi who, along with Luigi Devoto, was the first and sole editor at the Journal's foundation; up to the present extended and impressive editorial board; the printers (from the first. Tipografia Cooperativa, Via dei Molini in Pavia, to the latest: Casa Editrice Mattioli in Fidenza); the sponsors, including the most evident who, via advertising (rather limited as a matter offact), directly gave information about themselves, but also those who have often been or are behind the scenes, ensuring fundamental support which is not visible; content. articles, news, events, reports, ideas, opinions, photographs, tables, numbers... etc, which are really impossible to sum up. But the true collection which, for obvious reasons, cannot be

  10. 77 FR 18813 - Rescission of Previously Issued Cancellation Order for Methyl Parathion Product Registration

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-28

    ..., human health, and agricultural advocates; the chemical industry; pesticide users; and members of the... registrations for all other chemicals that were included in the December 28, 2011 cancellation order remain in... force and effect with respect to all other product registrations and chemicals contained in...

  11. 76 FR 40727 - Methyl Parathion; Rescission of Previously Issued Cancellation Orders and Issuance of Revised...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-11

    ... registrations. All other product registrations for all other chemicals that were included in the above mentioned... range of stakeholders including environmental, human health, and agricultural advocates; the chemical industry; pesticide users; and members of the public interested in the sale, distribution, or use...

  12. 75 FR 57787 - Methyl Parathion; Notice of Receipt of Request to Voluntarily Cancel Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-22

    ...), Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA... in Rm. S-4400, One Potomac Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The hours of..., Suite 402 King of Prussia, PA 19406. IV. What is the agency's authority for taking this action?...

  13. 75 FR 41482 - Methyl Parathion; Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-16

    .... S- 4400, One Potomac Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The hours of operation... Phosphorus 630 Freedom Business Center, Suite 402 King of Prussia, PA 19406 III. Summary of Public...

  14. 75 FR 41484 - Methyl Parathion; Registration Review Proposed Decision; Notice of Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-16

    ... alfalfa, almonds, barley, canola/rapeseed, corn (field, pop, and sweet), cotton, grass (forage), oats, onions, potatoes (sweet and white), rice, rye, soybeans, sunflowers, walnuts, and wheat. There are...

  15. 75 FR 22402 - Methyl Parathion; Notice of Receipt of Request to Voluntarily Cancel Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ..., potatoes (sweet and white), rice, rye, soybeans, sunflowers, walnuts, and wheat. The requests would... (sweet and white), rice, rye, soybeans, sunflowers, walnuts, and wheat, with the majority of...

  16. Living Legacy: A Conversation with Carolina Gomez del Valle.

    ERIC Educational Resources Information Center

    Montessori Life, 1993

    1993-01-01

    Carolina Gomez del Valle has been involved in training other Montessorians in Mexico, Chile, Nicaragua, Peru, and Taiwan. This interview explores her experiences with Montessori education and describes how she has woven her religious training and Montessori philosophy together. (PAM)

  17. On some structure results for Gödel-type spacetimes

    NASA Astrophysics Data System (ADS)

    Plaue, Matthias; Scherfner, Mike

    2016-12-01

    In this paper, we prove structure results on Gödel-type spacetimes, which we understand as stationary charged perfect fluid solutions of the Einstein-Maxwell equations with geodesic flow. Given in a standard product form, we investigate relations between the vorticity and the geometry of the fiber. For the four dimensional case in particular, we classify the Gödel-type spacetimes with constant vorticity scalar. We give a complete list of the solutions, which provides a generalization of an observation by Gödel, proved later by Ozsváth: The Gödel spacetime and Einstein's static universe are the only stationary Λ-dust solutions of Einstein's equations with positive energy density that are spatially homogeneous.

  18. Estudio del sistema simbiótico AR Pavonis

    NASA Astrophysics Data System (ADS)

    Quiroga, C.; Brandi, E.; Ferrer, O.; García, L.; Barbá, R.

    Se presenta un estudio espectroscópico y polarimétrico de la binaria eclipsante AR Pavonis a partir de observaciones obtenidas con el telescopio de 2.15 m. del CASLEO (San Juan). El estudio de la naturaleza del sistema se realizó a través del análisis de algunos espectros reunidos entre los años 1990 y 1995 y de datos polarimétricos correspondientes al intervalo 1995 y 1997. El análisis espectroscópico indica que AR Pav está compuesta por una gigante roja M3.7 y una componente caliente compacta, con una temperatura mayor a 90000 K y una luminosidad del orden de 500Lsolar. A lo largo del período orbital, las variaciones observadas en flujo y en velocidades radiales, reflejan que las emisiones permitidas se forman en una región que rodea la componente caliente. El estudio de la polarización lineal de AR Pav indica que además de una componente interestelar, existe una componente intrínseca del sistema que varía temporalmente y con la longitud de onda de la luz polarizada. El distinto comportamiento del grado de polarización y del ángulo de posición observado en fases diferentes, sugiere que distintos mecanismos pueden estar actuando, dependiendo de la región de scattering observado a lo largo de la línea de la visual.

  19. 65. Photographer unknown March 1931 DEL NORTE COUNTY, SECTION B, ...

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

    65. Photographer unknown March 1931 DEL NORTE COUNTY, SECTION B, HIGHWAY 1, 1-DN-1-B #66A, STA. 166.0+00 WIDENED ROADBED BEFORE COVERING LOG CRIB, 3-31. BACK READS: WIDENING ROAD BED WITH LOGS, APPROX 30 SQUARE & 60 LONG ON DN-1 SEC B STA 156+. Stamped office copy, - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

  20. Extreme Environments in Tierra del Fuego, Argentina

    NASA Astrophysics Data System (ADS)

    Schultz, C.; D'Antoni, H.; Burgess, S.; Zamora, J.; Skiles, J.

    2007-12-01

    The upper timberline of the Andes Cordillera on the island of Tierra del Fuego at the tip of South America is an environment subject to extreme conditions. In order to further understand this environment, ecosystem parameters were measured within two transects of the Andes at Glaciar Martial and Cerro Guanaco. The measurements included pH, soil temperature, soil moisture, nitrogen, sodium and potassium concentration, chlorophyll absorbance, and irradiance in the ultraviolet range (200-400 nm). These data comprise a survey that serves as a baseline for an intensive research program. Chlorophyll concentration and soil data were within the range of our observations at several other sites, from Lapataia Bay on the southwestern boundary with Chile, through the eastern end of Lake Fagnano. However, unusual levels of solar irradiance were found in the open sites of both transects while those in the forest exhibited lower UV values, suggesting strong absorption and/or reflection by the forest canopy. High levels of UV radiation damage important biomolecules and may be partially responsible for the presence of life forms such as the krummholz belt in the upper timberline. These UV values may be due to the effects of global ozone depletion and the ozone hole. The low temperatures, strong winds, snow and ice-covered soil and especially the exposure to UV radiation make this area an extreme environment for life.

  1. Confirming and Improving Ross Variable Star RV Del

    NASA Astrophysics Data System (ADS)

    Linder, Tyler R.; Sanchez, Rick; Palser, Sage; Schultze, Kendra; Kenney, Jessica; Thompson, Briana; DeCoster, Richard; Mills, Frank; Osborn, Wayne; Hoette, Vivian L.; Skynet Junior Scholars; Stone Edge Observatory

    2017-01-01

    RV Del is an intrinsic pulsating variable star in the constellation Delphinus, discovered by Ross (1926). The AAVSO list RV Del as a RRAB type of variable star. RV Del has been found to have a magnitude that varies from 12.9 - 14.2 and a period of 11.9553 hours.The purpose of our research of RV Del is to confirm and improve previous results as well as explore different methods to engage middle school students in the scientific method and astronomy. The SKYNET network of telescopes allows students to request images from a group of international research class telescopes. The telescope request process allows students first-hand experience in astronomy while the data analysis allows students to understand advance software systems to produce publishable results. Data is being gathered using the SKYNET network and Stone Edge Observatory to gather photometry of RV Del and create a new light curve. Findings will be presented the January 2017 AAS.

  2. DEL-TYPE Universes in f(T) Gravity

    NASA Astrophysics Data System (ADS)

    Liu, Di; Wu, Puxun; Yu, Hongwei

    2012-09-01

    The issue of causality in f(T) gravity is investigated by examining the possibility of existence of the closed timelike curves in the Gödel-type metric. By assuming a perfect fluid as the matter source, we find that the fluid must have an equation of state parameter greater than minus one in order to allow the Gödel solutions to exist, and furthermore the critical radius rc, beyond which the causality is broken down, is finite and it depends on both matter and gravity. Remarkably, for certain f(T) models, the perfect fluid that allows the Gödel-type solutions can even be normal matter, such as pressureless matter or radiation. However, if the matter source is a special scalar field rather than a perfect fluid, then rc → ∞ and the causality violation is thus avoided.

  3. May Gödel's Ideas Be Addressed Philosophically?

    NASA Astrophysics Data System (ADS)

    Dokulil, Miloš

    2007-11-01

    del emphasised philosophy as an important tool in science. Much less is known about his religious background. We should bear in mind that our evaluational perspective differs very much from the one in which Gödel lived. He was personally sure that there must be another existence after death-an afterlife (''of unlimited life span''). As a ''Baptized Lutheran'' he did not include ''Trinity'' in his creed. He was also certain that mind is separate from matter. This text tries to include Libet's ''readiness potential'' into the debate concerning the specificity of the mind. Neither Gödel's identification of materialism with mechanism nor his vision of the ''spirit'' are a viable solution of the problem.

  4. The novel c.247_249delTTC (p.F83del) GJB2 mutation in a family with prelingual sensorineural deafness.

    PubMed

    Petersen, Michael B; Grigoriadou, Maria; Koutroumpe, Maria; Kokotas, Haris

    2012-07-01

    Non-syndromic hearing loss is one of the most common hereditary determined diseases in human, and the disease is a genetically heterogeneous disorder. Mutations in the GJB2 gene, encoding connexin 26 (Cx26), are a major cause of non-syndromic recessive hearing impairment in many countries and are largely dependent on ethnic groups. Due to the high frequency of the c.35delG GJB2 mutation in the Greek population, we have previously suggested that Greek patients with sensorineural, non-syndromic deafness should be tested for the c.35delG mutation and the coding region of the GJB2 gene should be sequenced in c.35delG heterozygotes. Here we present on the clinical and molecular genetic evaluation of a family suffering from prelingual, sensorineural, non-syndromic deafness. A novel c.247_249delTTC (p.F83del) GJB2 mutation was detected in compound heterozygosity with the c.35delG GJB2 mutation in the proband and was later confirmed in the father, while the mother was homozygous for the c.35delG GJB2 mutation. We conclude that compound heterozygosity of the novel c.247_249delTTC (p.F83del) and the c.35delG mutations in the GJB2 gene was the cause of deafness in the proband and his father.

  5. Mejoras en la exactitud del reloj de ángulo horario del telescopio de 2,15 mts de CASLEO

    NASA Astrophysics Data System (ADS)

    Aballay, J. L.; Pereyra, P. F.; Marún, A. H.

    Para aumentar la exactitud en el control del ángulo horario del telescopio, se está implementando el uso de un reloj con una precisión de 1/100 seg. En conjunto con el encoder que otorga la posición con un acierto de 0,012 seg. de arco, se podrá implementar otro dígito en el reloj de ángulo horario con la posibilidad de ver las décimas. Esto, sumado a la precisión ya lograda en declinación, permitirá realizar offsets con mayor exactitud.

  6. Cirugía de los trastornos del comportamiento: el estado del arte

    PubMed Central

    Yampolsky, Claudio; Bendersky, Damián

    2014-01-01

    Introducción: La cirugía de los trastornos del comportamiento (CTC) se está convirtiendo en un tratamiento más común desde el desarrollo de la neuromodulación. Métodos: Este artículo es una revisión no sistemática de la historia, indicaciones actuales, técnicas y blancos quirúrgicos de la CTC. Dividimos su historia en 3 eras: la primera comienza en los inicios de la psicocirugía y termina con el desarrollo de las tícnicas estereotácticas, cuando comienza la segunda era. Ésta se caracteriza por la realización de lesiones estereotácticas. Nos encontramos transitando la tercera era, que comienza cuando la estimulación cerebral profunda (ECP) comienza a ser usada en CTC. Resultados: A pesar de los errores graves cometidos en el pasado, hoy en día, la CTC está renaciendo. Los trastornos psiquiátricos que se más frecuentemente se tratan con cirugía son: depresión refractaria, trastorno obsesivo-compulsivo y síndrome de Tourette. Además, algunos pacientes con agresividad fueron tratados quirúrgicamente. Hay varios blancos estereotácticos descriptos para estos trastornos. La estimulación vagal puede ser usada también para depresión. Conclusión: Los resultados de la ECP en estos trastornos parecen alentadores. Sin embargo, se necesitan más estudios randomizados para establecer la efectividad de la CTC. Debe tenerse en cuenta que una apropiada selección de pacientes nos ayudará a realizar un procedimiento más seguro así como también a lograr mejores resultados quirúrgicos, conduciendo a la CTC a ser más aceptada por psiquiatras, pacientes y sus familias. Se necesita mayor investigación en varios temas como: fisiopatología de los trastornos del comportamiento, indicaciones de CTC y nuevos blancos quirúrgicos. PMID:25165612

  7. Design, aerodynamics and autonomy of the DelFly.

    PubMed

    de Croon, G C H E; Groen, M A; De Wagter, C; Remes, B; Ruijsink, R; van Oudheusden, B W

    2012-06-01

    One of the major challenges in robotics is to develop a fly-like robot that can autonomously fly around in unknown environments. In this paper, we discuss the current state of the DelFly project, in which we follow a top-down approach to ever smaller and more autonomous ornithopters. The presented findings concerning the design, aerodynamics and autonomy of the DelFly illustrate some of the properties of the top-down approach, which allows the identification and resolution of issues that also play a role at smaller scales. A parametric variation of the wing stiffener layout produced a 5% more power-efficient wing. An experimental aerodynamic investigation revealed that this could be associated with an improved stiffness of the wing, while further providing evidence of the vortex development during the flap cycle. The presented experiments resulted in an improvement in the generated lift, allowing the inclusion of a yaw rate gyro, pressure sensor and microcontroller onboard the DelFly. The autonomy of the DelFly is expanded by achieving (1) an improved turning logic to obtain better vision-based obstacle avoidance performance in environments with varying texture and (2) successful onboard height control based on the pressure sensor.

  8. 77 FR 50080 - Del Norte County Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-20

    ... Forest Service Del Norte County Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice.... The purpose of the committee is to improve collaborative relationships and to provide advice and recommendations to the Forest Service concerning projects and funding consistent with the title II of the Act....

  9. Interdisciplinary Unit: La Isla del Encanto (The Enchanted Island).

    ERIC Educational Resources Information Center

    Ford-Guerrera, Rebecca

    This document presents a series of 14 lesson plans in an interdisciplinary Spanish unit on "La isla del encanto/The Enchanted Island." The materials were prepared for students in grades 5 or 6 who have had basic Spanish instruction in previous grades. The students should also be familiar with basic concepts in English such as math…

  10. Cosmogenic Radionuclides in the Campo Del Cielo Iron Meteorite

    NASA Technical Reports Server (NTRS)

    Liberman, R. G.; FernandezNiello, J. O.; Reedy, R. C.; Fifield, L. K.; diTada, M. L.

    2001-01-01

    Cosmogenic Be-10, Al-26, Cl-36, Ca-41, and Ni-59 were measured in the Campo del Cielo iron meteorite. Our results led us to conclude that the pre-atmospheric radius might have been approximately 2 m. Comparisons with other big bodies are also presented. Additional information is contained in the original extended abstract.

  11. Faculty Activity Analysis in the Universidad Tecnica Del Estado Campuses.

    ERIC Educational Resources Information Center

    Karadima, Oscar

    An analysis of academic activities of college faculty at the eight campuses of Chile's Universidad Tecnica del Estado was conducted. Activities were grouped into seven categories: direct teaching, indirect teaching, research, community services, faculty development, academic administration, and other activities. Following the narrative…

  12. Análisis del futuro marco de referencia internacional

    NASA Astrophysics Data System (ADS)

    Cionco, G. R.; Arias, E. F.

    La técnica de interferometría de muy larga línea de base (VLBI) se aplica hoy a la astrometría para el cálculo de posiciones precisas de radiofuentes extragalácticas. Por tratarse de objetos lejanos, sus movimientos propios aparentes pueden considerarse nulos; esta propiedad hace que los catálogos de radiofuentes extragalácticas VLBI constituyan la mejor materialización de un sistema de referencia celeste inercial definido cinemáticamente. La Unión Astronómica Internacional (IAU) recomendó la adopción de un nuevo sistema de referencia celeste internacional materializado por las coordenadas ecuatoriales de objetos extragalácticos observados con le técnica VLBI. Para superar la precisión astrométrica actual es necesaria una mejora en la modelización de aquellos fenómenos que pueden introducir desviaciones sistemáticas en el marco de referencia celeste. El objetivo de este trabajo es poner de manifiesto las sistematicidades presentes en los distintos marcos de referencia elaborados con el próposito de materializar el nuevo sistema de referencia celeste de la IAU. Para la comparación de los distintos marcos de referencia se propone un modelo de tres rotaciones diferenciales más un término lineal que procura absorber los efectos sistemáticos presentes en las coordenadas. Se analiza igualmente la estabilidad de la solución cuando se utilizan distintos conjuntos de objetos de definición.

  13. Analisis del contenido curricular de los Documentos Normativos del Programa de Ciencias en el area de biologia para la escuela superior del sistema de educacion publica de Puerto Rico: 1993-2012

    NASA Astrophysics Data System (ADS)

    Davila Montanez, Melissa

    Esta investigacion de naturaleza cualitativa se ocupo de realizar un analisis de contenido documental de los Documentos Normativos del Programa de Ciencias en el area de biologia de la escuela superior del sistema de educacion publica de Puerto Rico del periodo 1993-2012. Los documentos analizados fueron: Guia Curricular, 1995; Marco Curricular, 2003; Estandares de Excelencia, 1996, 2000 y Estandares de Contenido y Expectativas de Grado, 2007. Se indago si hubo cambios en significados en los Componentes Estructurales: Naturaleza de la ciencia, Paradigmas para la ensenanza de la ciencia, Funcion del curriculo formal, Mision de la ensenanza de la ciencia; Contenidos, destrezas y competencias, Estrategias de ensenanza y Evaluacion/Assessment del aprendizaje. El analisis sugiere que no hubo cambios sustanciales en los significados de los Componentes Estructurales. Los documentos estudiados muestran mayormente caracteristicas similares, aunque los documentos mas recientes eran mas descriptivos, explicativos y especificos.

  14. Biological and behavioral determinants of fertility in Tierra del Fuego.

    PubMed

    Pascual, J; García-Moro, C E; Hernández, M

    2005-05-01

    The reproductive history of 182 women in postreproductive life or near menopause from the Chilean part of Tierra del Fuego was traced back by means of familial interviews. These postmenopausal women represent the population since almost the beginning of the settlement, and their reproductive years were spent on the island. Path analysis was applied to analyze fertility determinants of these women and to propose a complex model of interconnections among factors. The reproductive history of these women is characterized by a long fertile span, a short childbearing period, and low fertility. Age at menarche is relatively late, and the age of the women at first birth is mainly determined by their late age at marriage. The use of contraception is related to both spacing and stopping behaviors. The late age of women at marriage, the rhythm of conception, and practices of contraception are proposed as the main determinants of fertility in Tierra del Fuego.

  15. The first century of the "clinica del lavoro" in Milan.

    PubMed

    Bertazzi, Pier Alberto; Foà, Vito

    2005-01-01

    The Clinica del Lavoro was created in Milan at the beginning of the 20th century by Luigi Devotto, who deemed it essential for physicians and health researchers to get involved in the life and health problems of working populations. The main roles of the Clinica del Lavoro were to educate medical students and train physicians; study actual workplaces, examine health and safety hazards and their noxious effects; and create initiatives and services to protect and promote workers' health. Important scientific contributions were made in several fields, including chemical carcinogenesis, effects of mineral and biologicalfibers, mechanism of action of silica dust, methods for the detection and measurements of toxic substances in both the work environment and workers' biological media.

  16. New records of fishes at Isla del Coco, Costa Rica

    USGS Publications Warehouse

    Garrison, V.H.

    1996-01-01

    Isla del Coco lies at 5 degrees 32'N latitude, 87 degrees 04'W longitude and is the sole peak of the Cocos Ridge exposed above sea level. This isolated island formed approximately 2 million years ago. It rises 575 m above the surface of the sea and covers 46 km2 (Castillo et aI., 1988). Five hundred km to the NNE is Costa Rica; 630 km SSW are the Galapagos Islands; 650 km to the E is Isla Malpelo, Colombia; and approximately 8,000 km W lie the Line Islands. Costa Rica claimed Isla del Coco in 1832 and declared it a National Park in 1978. The area of the park was increased to include the adjacent waters 5 km offshore in 1984 and 25 km offshore in 1991.

  17. Prognostic Impact of del(17p) and del(22q) as Assessed by Interphase FISH in Sporadic Colorectal Carcinomas

    PubMed Central

    González-González, María; Muñoz-Bellvis, Luís; Mackintosh, Carlos; Fontanillo, Celia; Gutiérrez, M. Laura; Abad, M. Mar; Bengoechea, Oscar; Teodosio, Cristina; Fonseca, Emilio; Fuentes, Manuel; De Las Rivas, Javier

    2012-01-01

    Background Most sporadic colorectal cancer (sCRC) deaths are caused by metastatic dissemination of the primary tumor. New advances in genetic profiling of sCRC suggest that the primary tumor may contain a cell population with metastatic potential. Here we compare the cytogenetic profile of primary tumors from liver metastatic versus non-metastatic sCRC. Methodology/Principal Findings We prospectively analyzed the frequency of numerical/structural abnormalities of chromosomes 1, 7, 8, 13, 14, 17, 18, 20, and 22 by iFISH in 58 sCRC patients: thirty-one non-metastatic (54%) vs. 27 metastatic (46%) disease. From a total of 18 probes, significant differences emerged only for the 17p11.2 and 22q11.2 chromosomal regions. Patients with liver metastatic sCRC showed an increased frequency of del(17p11.2) (10% vs. 67%;p<.001) and del(22q11.2) (0% vs. 22%;p = .02) versusnon-metastatic cases. Multivariate analysis of prognostic factors for overall survival (OS) showed that the only clinical and cytogenetic parameters that had an independent adverse impact on patient outcome were the presence of del(17p) with a 17p11.2 breakpoint and del(22q11.2). Based on these two cytogenetic variables, patients were classified into three groups: low- (no adverse features), intermediate- (one adverse feature) and high-risk (two adverse features)- with significantly different OS rates at 5-years (p<.001): 92%, 53% and 0%, respectively. Conclusions/Significance Our results unravel the potential implication of del(17p11.2) in sCRC patients with liver metastasis as this cytogenetic alteration appears to be intrinsically related to an increased metastatic potential and a poor outcome, providing additional prognostic information to that associated with other cytogenetic alterations such as del(22q11.2). Additional prospective studies in larger series of patients would be required to confirm the clinical utility of the new prognostic markers identified. PMID:22912721

  18. 2. COURSE OF THE LATERAL THROUGH DEL NORTHWEST MAR PARK. ...

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

    2. COURSE OF THE LATERAL THROUGH DEL NORTHWEST MAR PARK. - Highline Canal, Sand Creek Lateral, Beginning at intersection of Peoria Street & Highline Canal in Arapahoe County (City of Aurora), Sand Creek lateral Extends 15 miles Northerly through Araphoe County, City & County of Denver, & Adams County to its end point, approximately 1/4 mile Southest of intersectioin of D Street & Ninth Avenue in Adams County (Rocky Mountain Arsenal, Commerce City Vicinity), Commerce City, Adams County, CO

  19. 3. 1939 DROP STRUCTURE IN DEL MAR PARK SURMOUNTED BY ...

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

    3. 1939 DROP STRUCTURE IN DEL MAR PARK SURMOUNTED BY RECENT PEDESTRIAN BRIDGE. - Highline Canal, Sand Creek Lateral, Beginning at intersection of Peoria Street & Highline Canal in Arapahoe County (City of Aurora), Sand Creek lateral Extends 15 miles Northerly through Araphoe County, City & County of Denver, & Adams County to its end point, approximately 1/4 mile Southest of intersectioin of D Street & Ninth Avenue in Adams County (Rocky Mountain Arsenal, Commerce City Vicinity), Commerce City, Adams County, CO

  20. Determinacion de Caracteristicas Opticas del Telescopio OAN150

    NASA Astrophysics Data System (ADS)

    Galan, M. J.; Cobos, F. J.

    1987-05-01

    En el Observatorio de Calar Alto, en Almería, España, está ubicado un telescopio de 15O-cms de diámetro -construído por REOSC- perteneciente al Observatorio Astronómico Nacional, con sede en Madrid, España. La infraestructura técnica del OAN ha sido tradicionalmente débil y actualmente se está haciendo un esfuerzo por fortalecerla. Existe una información muy limitada del telescopio en general; de su óptica en particular se conocían los valores de los parámetros principales pero sin saber si éstos corresponden a valores teóricos ó de construcción. Por ello se consideró necesario iniciar una investigación para conocer en detalle los valores reales de las componentes ópticas del telescopio, obteniéndose algunos resultados de interés. El primario del telescopio OANl5O es aproximadamente F/3 y el siste ma en su conjunto es F/8.2, con su sistema corrector de campo. En términos generales, la imagen es satisfactoria en todo el campo y, sin sistema corrector, la imagen axial también es buena. En un futuro muy cercano se piensa diseñar instrumentación adicional para este telescopio. Conocer con mayor precisión sus características puede ser de gran utilidad para tal fin, pues se efectúan los cálculos considerando conjuntamente al telescopio y al instrumento.

  1. Solar adaptive optics at the Observatorio del Teide, Tenerife

    NASA Astrophysics Data System (ADS)

    Soltau, Dirk; Berkefeld, Thomas; Schmidt, Dirk; von der Lühe, Oskar

    2013-10-01

    Observing the Sun with high angular resolution is difficult because the turbulence in the atmosphere is strongest during day time. In this paper we describe the principles of solar adaptive optics exemplified by the two German solar telescopes VTT and GREGOR at the Observatorio del Teide. With theses systems we obtain near diffraction limited images of the Sun. Ways to overcome the limits of conventional AO by applying multiconjugate adaptive optics (MCAO) are shown.

  2. Modeling Visibility in the EL Paso del Norte Region

    NASA Astrophysics Data System (ADS)

    Fitzgerald, R. M.; Medina, R.; DuBois, D. W.; Novlan, D.

    2013-12-01

    Poor visibility is a subject of growing public concern throughout the U.S, and an active area of research. Its societal impacts in air quality, aviation transport and traffic are significant. Aerosols play a fundamental role in the attenuation of solar radiation, and also affect visibility. The scattering and extinction coefficients of aerosol particles in the Paso del Norte Region have been calculated using the T- matrix model in conjunction with a laser particle counter. Inter-comparison of the model's results of the scattering and absorption coefficients against the corresponding data from a Photoacustic Extinctiometer instrument (which measures in-situ absorption and scattering coefficients of aerosol particles) shows excellent agreement. In addition, the volume-weighted method is used to determine the composite index of refraction which is representative of the aerosols for the Paso del Norte Airshed to obtain information of the type of aerosol particles present in the Airshed. The Single Scattering Albedo has also been retrieved using our methodology to obtain further insight into the type of aerosols present on a given day. Finally, the Koschmieder equation has been used to calculate the visual range or visibility, and was correlated with the PM2.5 and PM10 particle concentration present in the Airshed. Our methodology will allow a better understanding of the size and type of aerosol particles that are most detrimental to the visibility for the Paso del Norte Region.

  3. Modeling visibility in the Paso del Norte (PDN) Region

    NASA Astrophysics Data System (ADS)

    Medina Calderon, Richard

    Poor visibility is a subject of growing public concern throughout the U.S, and an active area of research. Its societal impacts on air quality, aviation transport and traffic are significant. Aerosols play a fundamental role in the attenuation of solar radiation, and also affect visibility. The scattering and extinction coefficients of aerosol particles in the Paso del Norte Region have been calculated using the T- matrix model in conjunction with a laser particle counter. Inter-comparison of the model's results of the scattering and absorption coefficients against the corresponding data from a Photoacustic extinctiometer instrument (which measures in-situ absorption and scattering coefficients of aerosol particles) shows excellent agreement. In addition, the volume-weighted method is used to determine the composite index of refraction which is representative of the aerosols for the Paso del Norte Region to obtain information of the type of aerosol particles present in the Region. The Single Scattering Albedo has also been retrieved using this methodology to obtain further insight into the type of aerosols present on a given day. Finally, the Koschmieder equation has been used to calculate the visual range or visibility, and was correlated with the PM2.5 and PM10 particle concentration present in the Region. Our methodology will allow a better understanding of the size and type of aerosol particles that are most detrimental to the visibility for the Paso Del Norte Region.

  4. Los plaguicidas y la contaminacion del medio ambiente Venezolano

    USGS Publications Warehouse

    Stickel, L.F.; Stickel, W.H.

    1972-01-01

    RESUMEN DE RECOMENDACIONES Recomendaciones para el Programa de Investigacion: 1. Establecer un sistema de muestreo biologico para detectar los niveles tendencias de los productos quimicos toxicos en un peque?o numero de si tios representativos. 2. Mantener continua vigilancia de la contaminacion ambiental, mediante la seleccion acertadamente dirigida de las zonas afectadas y de las fuentes de contaminacion. 3. Realizar estudios acerca de las poblaciones de animales silvestres, y del exito de los procesos reproductivos de las especies o grupos clayes de animales que se consideran mas gravemente afectados. 4. Preparar recomendaciones para una accion gubernamental de proteccion al hombre, a la fauna silvestre y al medio ambiente. Recomendaciones para la Accion Administrativa: 1. Establecer limites a la tolerancia de los residuos de plaguicidas en los alimentos. Constituye una medida clave para disminuir la contaminacion ambiental. 2. Establecer normas de calidad del agua para las corrientes, represas, la gos y otros cuerpos. Es la segunda medida clave para reducir la contaminacion del ambiente 3. Exigir un tratamiento adecuado de los efluentes industriales, especialmente antes de que se construyan las nuevas plantas. 4. Exigir a los agricultores que en el uso de plaguicidas sigan los consejos tecnicos autorizados y negar a los vendedores el derecho a recomendar productos por su cuenta. 5. Tomar medidas para recoger y eliminar los recipientes y sobrantes de los plaguicidas.

  5. [Validazione del Gambling Disorder Screening Questionnaire, un questionario diagnostico autosomministrato per il gioco d'azzardo patologico basato sui criteri del DSM-5].

    PubMed

    Villella, Corrado; Pascucci, Marco; de Waure, Chiara; Bellomo, Antonello; Conte, Gianluigi

    2016-01-01

    RIASSUNTO. Scopo. Il DSM-5 presenta delle modifiche nei criteri diagnostici per il gioco d'azzardo patologico, rispetto alla precedente edizione del manuale; è pertanto necessario sviluppare nuovi strumenti diagnostici. Questo studio ha valutato le caratteristiche psicometriche del Gambling Disorder Screening Questionnaire (GDSQ), un questionario sviluppato per l'autosomministrazione, basato sui criteri diagnostici del DSM-IV e del DSM-5 per il gioco d'azzardo patologico, misurandone la validità e la consistenza interna e sottoponendo il questionario all'analisi delle componenti principali. Metodi. 71 pazienti reclutati da un ambulatorio dedicato al gioco d'azzardo patologico e 70 controlli sono stati valutati con il GDSQ, con il South Oaks Gambling Screen (SOGS) e con valutazione psichiatrica. Risultati. Il test ha mostrato una buona sensibilità, specificità, consistenza interna, correlazione con il SOGS. L'esclusione del criterio degli atti illeciti e l'abbassamento del punteggio di cut-off a quattro criteri positivi, come suggerito dal DSM-5, migliora la sensibilità e consistenza interna del test. Discussione e conclusioni. Il GDSQ può essere considerato un utile test di screening per il gioco d'azzardo patologico. Inoltre, questo studio conferma il miglioramento nell'accuratezza diagnostica dei criteri elencati nella quinta edizione del Manuale Diagnostico e Statistico dei Disturbi Mentali rispetto alla precedente edizione.

  6. The 2012 Reactivation of Nevado del Ruiz Volcano, Colombia

    NASA Astrophysics Data System (ADS)

    Ordoñez, M.; Lopez, C.; Cortes, G. P.; Londoño, J.; Battaglia, M.

    2012-12-01

    Nevado Del Ruiz volcano is most known for its tragic November 13, 1985 explosive event, when a small eruption produced an enormous lahar that buried and destroyed the town of Armero in Tolima, causing an estimated 25,000 deaths. Similar but less deadly incidents occurred in 1595 and 1845, again where a small explosive eruption was followed by a large lahar. Other minor explosive events occurred in 1805, 1828-9, and 1989. The Armero tragedy was a major factor in the establishment of a volcano monitoring program in Colombia. The network monitoring Nevado del Ruiz volcano has dramatically improved since the 1985 eruption and now includes geodetic, geophysical, geochemical and visual monitoring. The activity of Nevado Del Ruiz between 1985 and 1991 saw significant increases in seismicity and significant gas emissions with the main eruptive events of November 13, 1985 and September 1st, 1989. The volcano became seismically active again in 1995 and 2002, whit an increase in seismicity, without any gas emission or eruption. In October 2010 the volcano entered in a new phase of unrest with increased seismicity (HB events), deformation and gas emissions, likely associated with a new magma intrusion. In February, 2012 the volcano had a new and significant increase in seismicity (VT-LP), followed in May and June 2012 by small phreatic and phreato-magmatic eruption. This eruptive activity is still ongoing. Deformation measurements at Nevado Del Ruiz volcano have been carried out since just after the tragic eruption of the 13th of November 1985. In 2007 seven new electronic tilt meters were set up to monitor the deformation. Significant uplift was measured from August 2007 to October 2010, for a total cumulative value of more than 500 microradians. From the end of 2011 to July 2012, moderate changes of uplift were detected for a total of 70 microradians. The analysis of these deformation data shows a pattern of surface displacement associated with an intrusion of new magma

  7. Estrategia innovadora enfocada en parejas del mismo sexo para disminuir la infección del VIH en hombres Latinos

    PubMed Central

    Martinez, Omar; Wu, Elwin; Sandfort, Theo; Shultz, Andrew Z.; Capote, Jonathan; Chávez, Silvia; Moya, Eva; Dodge, Brian; Morales, Gabriel; Porras, Antonio; Ovejero, Hugo

    2014-01-01

    Resumen El VIH es un problema de salud importante dentro de la comunidad latina de los Estados Unidos. Gracias a los esfuerzos de prevención, los niveles de contagio entre los latinos se han mantenido estables por más de una década. Sin embargo, esta población sigue siendo afectada a niveles muy altos, en particular entre hombres que tienen sexo con hombres (HSH), de origen latino y que hablan principalmente el idioma español. Existen varios factores que contribuyen a la transmisión del VIH entre esta población, como son: el uso de drogas; la violencia dentro de la pareja; la presencia de infecciones de transmisión sexual; relaciones sexuales sin protección, dentro y fuera de la pareja; el evadir la búsqueda de recursos (prueba y tratamiento adecuado) por temor a ser discriminado o por su estatus migratorio; la escasez de recursos económicos o estado de pobreza y los patrones relacionados a la migración. En particular, Investigaciones Epidemiológicas de Comportamientos han determinado: cómo algunas dinámicas en parejas están directamente asociadas a los comportamientos sexuales de riesgos. En consecuencia, es necesaria mayor investigación para identificar esas dinámicas, y a su vez, realizar intervenciones dirigidas a la reducción de conductas de riesgo enfocadas en parejas de hombres del mismo sexo. En este escrito, se describe la importancia del uso de las relaciones de pareja como estrategia en la reducción de la trasmisión del VIH/SIDA en HSH de origen latino y que hablan principalmente el idioma español en los Estados Unidos. PMID:25580466

  8. Mars Reconnaissance Orbiter, Ground Data System, Receivables and Deliverables (REC/DELs)

    NASA Technical Reports Server (NTRS)

    Carlton, Magdi

    2006-01-01

    This paper presents one JPL element manager's approach to describe a complex Ground Data System (GDS) with its receivables and deliverables (REC/DEL). The Mars Reconnaissance Orbiter (MRO) Ground Data System is the integrated set of ground software, hardware, facilities and networks that support mission operation. REC/DEL is a powerful tool for specifying hierarchy of commitments among systems and teams. Receivable of a system is a deliverable of another system. Focusing on tangible products enables the manager to objectively measure progress in a schedule. The Jet Propulsion Laboratory mandates the use of REC/DEL for flight projects. Tutorial and training is provided for managers to create an integrated REC/DEL database using automated systems. Project schedules are based on REC/DELs. This paper is not focusing on the mechanics of REC/DEL database creation, but it provides a guideline how one systematically creates categories of deliverables and receivables for ground data system components...

  9. Mars Reconnaissance Orbiter, Ground Data System, Receivables and Deliverables (REC/DELs)

    NASA Technical Reports Server (NTRS)

    Carlton, Magdi

    2006-01-01

    This paper presents one JPL element manager's approach to describe a complex Ground Data System (GDS) with its receivables and deliverables (REC/DEL). The Mars Reconnaissance Orbiter (MRO) Ground Data System is the integrated set of ground software, hardware, facilities and networks that support mission operation. REC/DEL is a powerful tool for specifying hierarchy of commitments among systems and teams. Receivable of a system is a deliverable of another system. Focusing on tangible products enables the manager to objectively measure progress in a schedule. Jet Propulsion Laboratory mandates the use of REC/DEL for flight projects. Tutorial and training is provided for managers to create integrated REC/DEL database using automated systems. Project schedules are based on REC/DELs. This paper is not focusing on the mechanics of REC/DEL database creation, but it provides a guideline how one systematically creates categories of deliverables and receivables for ground data system components.

  10. Morfología de la Coma del Cometa Hale - Bopp

    NASA Astrophysics Data System (ADS)

    Gil-Hutton, R.; Caballero, M.; Coldwell, G.; Cañada, M.; Godoy, G.; Trozzo, C.; Gómez, G.

    Para lograr comprender plenamente los procesos físicos que se desarrollan en los núcleos cometarios y obtener un modelo que explique, no sólo su actividad, sino también sus efectos sobre la coma, es necesario obtener información detallada para el mayor número de cometas posible, siendo las características más interesantes para estudiar la ubicación de las regiones activas, la presencia de jets, las tasas de producción de gas y polvo y la interacción de la coma con el viento solar. En la actualidad, con técnicas de procesamiento de imágenes y tecnología CCD se pueden obtener este tipo de datos para cometas que ingresan al sistema solar interior y estudiar, de esta manera, la morfología de sus comas, tratando de correlacionar la actividad detectada con algún modelo teórico. En este trabajo se presenta un estudio parcial de la actividad desarrollada por el cometa Hale-Bopp, y sus efectos sobre la morfología de su coma, desde agosto de 1995 hasta la fecha en base a imágenes adquiridas con el telescopio de 0.76 m. de la Estación Astronómica Dr. Carlos Ulrrico Cesco.

  11. Effect of GJB2 235delC and 30-35delG genetic polymorphisms on risk of congenital deafness in a Chinese population.

    PubMed

    Xiong, Y; Zhong, M; Chen, J; Yan, Y L; Lin, X F; Li, X

    2017-02-08

    Congenital deafness is a serious and irreversible condition in humans. The GJB2 gene is implicated in the pathogenesis of autosomal recessive nonsyndromic hearing loss. Its 235delC and 30-35delG polymorphisms are reported to be associated with risk of hereditary deafness. However, the effect of the interaction between GJB2 235delC and 30-35delG and environmental factors on congenital deafness has not been described. Therefore, we performed a case-control study to investigate the influence of these polymorphisms on congenital deafness risk, and their interaction with maternal and other environmental factors in the development of this disease. Between March 2014 and May 2015, 118 patients with congenital deafness and 242 healthy controls were enrolled into our study. Compared with the GG genotype, the adjusted odds ratios (ORs) [and 95% confidence intervals (CIs)] for the 235delC GC and CC genotypes were 4.66 (1.77-13.07) and 8.28 (2.06-47.52), respectively. Individuals harboring the GC+CC genotypes were at a greatly increased risk of congenital deafness compared to those with the GG genotype (OR = 5.65, 95%CI = 2.54-13.18). However, no significant relationship was established between the 30-35delG variant and this disease. The 235delC polymorphism exhibited an interaction with use of aminoglycoside antibiotics during pregnancy in conferring susceptibility to congenital deafness (chi-square = 8.76, P = 0.003). In conclusion, our study suggests that the GJB2 235delC polymorphism, but not the 30-35delG variant, contributes to congenital deafness susceptibility in the Chinese population examined, and demonstrates an interaction with consumption of aminoglycoside antibiotics during pregnancy in exerting this effect.

  12. Non-seasonality of births in Tierra del Fuego (Chile).

    PubMed

    Pascual, J; García-Moro, C; Hernández, M

    2000-01-01

    Tierra del Fuego is situated at the southern tip of the American continent, which conditions its environmental and climatic characteristics. The colonizing population arrived, at the end of the 19th century, from other Chilean regions (particularly from Chiloé) and diverse European countries, especially Britain and Croatia, but also Germany, Spain and Italy. In the present study, the existence of a seasonal pattern in 5430 births registered in the Chilean population of Tierra del Fuego from 1890 to 1995 was analysed. The analysis showed no seasonal distribution of births in the periods 1890-1920 and from 1946 to the present day, a phenomenon rarely reported in the literature. The absence of seasonality in birth distribution could be related to the great diversity in the origins of the population's families, the constant renovation of this and the declining importance of the administrative capital of the province of Tierra del Fuego, Porvenir, in favour of Punta Arenas, capital of the Magellanic region. In the period of maximum development of the capital of the province, a seasonal pattern was detected with a peak in April and a trough in October, which corresponds with a maximum of conceptions in July and, in general, during the early southern winter and a decline in births from late spring to mid-summer, with a trough in January. This birth distribution is interpreted as a subordination of activity and social life to the annual sheep cycle. In addition to temporal trends, the influence on the observed patterns of environmental parameters, father's occupation, seasonality of marriage and the origin of the parents were analysed.

  13. Optical photometry and spectroscopy of Nova Del 2013

    NASA Astrophysics Data System (ADS)

    Tomov, T.; Ilkiewicz, K.; Swierczynski, E.; Belcheva, M.; Dimitrov, D.

    2013-08-01

    We report optical BV photometry and spectroscopy of Nova Del 2013, carried out between August 14.88 UT and August 15.08 UT. Using a 60 cm Cassegrain telescope at the Nicolaus Copernicus University Observatory (Torun, Poland) we estimated the V brightness of the Nova to be 6.31+/-0.02 mag and 6.18+/-0.03 mag on Aug. 14.94 UT and Aug. 15.02 UT respectively. HD 194113 (F2, V=8.00 mag) was used as a comparison star.

  14. Efectos Especiales de Anclaje (Estudio sobre Regresiones de Juicios Condicionales). Parte 2: Invariancia del Juicio No-Condicional Como Valor Estandar Para el Juicio Condicional (Special Effects of Anchoring (Study of Regression of Conditional Judgements) Part 2: Invariance of Unconditional Judgments as Standard Value for the Conditional Judgment). Publication No. 31.

    ERIC Educational Resources Information Center

    Lopez Alonso, A. O.

    From the best-fit lines corresponding to sets of families of conditional judgements, the constant stimulus family and the constant condition family, both defined for a same scale object, the coordinate values of the point of intersection of both lines (indifference point) are obtained. These values are studied in relation to the mean values of the…

  15. A novel compound heterozygous mutation (35delG, 363delC) in the Connexin 26 gene causes non-syndromic autosomal recessive hearing loss.

    PubMed

    Onsori, Habib; Rahmati, Mohammad; Fazli, Davood

    2014-01-01

    Mutations in the Connexin 26 (Cx26) gene are a common cause of hereditary hearing loss in different populations. In the present study, an Iranian patient with bilateral hearing loss underwent molecular analysis for the causative mutation. DNA studies were performed for the Cx26 gene by PCR and sequencing methods. We describe a novel compound heterozygous mutation (35delG, 363delC) in the Cx26 gene that is strongly associated with congenital non-syndromic hearing loss (NSHL).

  16. Content Analysis Schedule for Bilingual Education Programs: Del Valle Bilingual Education Program.

    ERIC Educational Resources Information Center

    Ehrlich, Roselin; Shore, Marietta Saravia

    This content analysis schedule for the Del Valle Bilingual Education Program of Del Valle, Texas, presents information on the history, funding, and scope of the project. Included are sociolinguistic process variables such as the native and dominant languages of students and their interaction. Information is provided on staff selection and the…

  17. 62. R.L.T., photographer November 1, 1934 DEL NORTE COUNTY, SECTION ...

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

    62. R.L.T., photographer November 1, 1934 DEL NORTE COUNTY, SECTION D, HIGHWAY 1. REDWOOD CLEARING ON EXISTING LINE, 1-DN-71-A #26, R.L.T. 11-1-34. Stamped office copy. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

  18. [Recommendations to improve the scientific communication process in the Revista Médica del IMSS].

    PubMed

    Álvarez, Ivón

    2016-01-01

    In order to improve the position of the Revista Médica del Instituto Mexicano del Seguro Social among the different journals, in this editorial we enumerate a series of recommendations to ameliorate the practices of the different actors who participate in the scientific communication process of this journal.

  19. Primer registro para Peru del genero Nielsonia Young, 1977 (Hemiptera: Cicadellidae: Cicadellinae: Cicadellini)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    En este articulo se reporta por primera vez para el Peru una especies del genero Nielsonia Young, 1977, de material procedente del Departamento de Tumbes. El genero ha sido reportada anteriormente de Ecuador, como unico registro para Sudamerica, y America Central. El unico especimen hembra encontra...

  20. IN VIVO INTERACTION BETWEEN CHLORPYRIFOS AND PARATHION IN ADULT RATS: SEQUENCE OF ADMINISTRATION CAN MARKEDLY INFLUENCE TOXIC OUTCOME. (R825811)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  1. COMPARATIVE NEUROCHEMICAL EFFECTS OF REPEATED METHYL PARATHION OR CHLORPYRIFOS EXPOSURES IN NEONATAL AND ADULT RATS. (R825811)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  2. Differential expression profile of membrane proteins in Aplysia pleural–pedal ganglia under the stress of methyl parathion.

    PubMed

    Chen, Ying-Ying; Huang, Lin; Zhang, Yong; Ke, Cai-Huan; Huang, He-Qing

    2014-03-01

    This study was aimed to analyze the alteration of membrane protein profiles in Aplysia juliana Quoy & Gaimard (A. juliana) pleural–pedal ganglia under MP exposure. Both the results of GC–MS analysis and the activity assay of acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT) reveal that MP toxicological effects on Aplysia left and right pleural–pedal ganglia are different under 7 and 14 days of exposure. Therefore, Aplysia were subjected for exposure at two concentrations (1 and 2 mg/l) of MP for 7 and 14 days for membrane proteomic study. As a result, 19 and 14 protein spots were differentially expressed in A. juliana left pleural–pedal ganglia under 7 and 14 days treatment, and 20 and 14 protein spots found with differential expressions in their right ganglia under the same treatment, respectively. Several proteins with expression variations were detected from both the left and right pleural–pedal ganglia; however, most proteins have distinctive expressions, indicating different mechanisms might be involved in initiating MP toxicology in left and right ganglia. Among the total differential protein spots obtained, 29 proteins were classed as membrane proteins. These proteins are mainly involved in the metabolism process, cell redox homeostasis, signal transduction, immunology, intracellular transport and catalysis, indicating MP toxicity in mollusks seems to be complex and diverse. Some differentially expressed proteins were further confirmed by Western blotting and quantitative real-time PCR. These results might provide renovated insights to reveal the mechanism of MP-induced neurotoxicity, and the novel candidate biomarkers might have potential application for environmental evaluation of MP pollution level.

  3. Screening of antibacterial activity of Amaicha del Valle (Tucumán, Argentina) propolis.

    PubMed

    Nieva Moreno, M I; Isla, M I; Cudmani, N G; Vattuone, M A; Sampietro, A R

    1999-12-15

    Propolis is extensively used in Argentine folk medicine. Alcoholic extracts of propolis from four localities of Amaicha del Valle (El Paraiso, La Banda Este, La Banda Oeste and El Molino), Province of Tucumán and from Cerrillos, Province of Santiago del Estero, Argentina were prepared. All showed antibacterial activity against Gram positive bacteria, the propolis from La Banda Este being the most active (MIC = 7.8 microg/ml) against Streptococcus piogenes, an antibiotic resistant bacterium. Thin layer chromatographic (TLC) separation profiles of propolis from Amaicha del Valle region were similar but differ from the alcoholic extract of the propolis from Cerrillos, another phytogeographical region of Argentina (provincia chaqueña). Bioautographic assays of the TLC profiles showed that several separated compounds of the Amaicha del Valle propolis have antibacterial activity. The difference in composition between Amaicha del Valle and Cerrillos propolis coincides with a different phytogeographical formation.

  4. Assessing Glacier Hazards At Ghiacciaio Del Belvedere, Macugnaga, Italian Alps

    NASA Astrophysics Data System (ADS)

    Haeberli, W.; Chiarle, M.; Mortara, G.; Mazza, A.

    The uppermost section of the Valle Anzasca behind and above the community of Macugnaga in the Italian Alps is one of the most spectacular high-mountain land- scapes in Europe, with gigantic rock walls and numerous steep hanging glaciers. Its main glacier, Ghiacciaio del Belvedere at the foot of the huge Monte Rosa east face, is a heavily debris-covered glacier flowing on a thick sediment bed. Problems with floods, avalanches and debris flows from this ice body have been known for extended time periods. Most recently, however, the evolution of this highly dynamic environ- ment has become more dramatic. An outburst of Lago delle Locce, an ice-dammed lake at the confluenec of the tributary Ghiacciaio delle Locce with Ghiacciaio del Belvedere, caused heavy damage in 1979 and necessitated site investigation and con- struction work to be done for flood protection. The intermittent glacier growth ten- dency in the 1970es induced strong bulging of the glacier surface and, in places, caused the glacier tongue to override historical morains and to destroy newly-grown forest stands. A surge-type flow acceleration started in the lower parts of the Monte- Rosa east face during summer 2000, leading to strong crevassing and deformation of Ghiacciaio del Belvedere and extreme bulging of its orographic right margin. High water pressure and accelerated movement lasted into winter 2001/2002: the ice now started overriding the LIA moraine near Rifugio Zamboni of the CAI. In addition but rather independently, a most active detachment zone for rock falls and debris flows developed for several years now in the east face of Monte Rosa, somewhat more to the south of the accelerated glacier movement and at an altitude where relatively warm permafrost must be expected. Besides the scientific interest in these phenomena, the growing hazard potential to the local infrastructure must be considered seriously. Es- pecially potentials for the destabilization of large rock and ice masses in the

  5. [History of Instituto Nacional de Salud Ocupacional del Peru].

    PubMed

    Cossio-Brazzan, Juan M

    2012-06-01

    In Peru, the industry's development has made economic improvements but at the same time, it has had a major impact on the health of the workers; for that reason, it was necessary to generate control mechanisms. So, in 1940 it was created the Departmento de Higiene Industrial, which in 1956 was changed to Instituto de Salud Ocupacional, but it was deactivated in 1994. However, in 2001 it reappeared into the Ministerio de Salud organizational structure with the name of Instituto de Salud Ocupacional "Alberto Hurtado Abadía". Actually, it is the Centro Nacional de Salud Ocupacional y Protección del Ambiente para la Salud (CENSOPAS), organ of the Instituto Nacional de Salud which continues working in synergy with other institutions and sectors, making research to protect the health of exposed persons (workers and community) to contamination and risks associated with economic activities.

  6. Spatially Controlled Fe Isotope Variations at Torres del Paine

    NASA Astrophysics Data System (ADS)

    Gajos, N.; Lundstrom, C.

    2013-12-01

    Recent advances in mass-spectrometry have identified systematic trends of non-traditional stable isotope variation in igneous rocks with differentiation index. We present new Fe isotope data for the Torres del Paine igneous complex in southern Chile. The multi-composition pluton consists of a 1 km vertical exposure of homogenous granite overlying a contemporaneous and possibly cogenetic 0.5 km mafic gabbro suite. Whereas previous isotopic investigations do little to address variations across important magmatic contacts, this study focuses on a first-of-its-kind spatially dependent non-traditional stable isotope investigation of an igneous pluton. Samples were collected at Torres del Paine in spatially significant transects, focusing on major contacts between country rock, granite and mafic units. Results collected by bracketed double spike MC-ICP-MS (2s precision of ×0.03) show an increase in δ56Fe towards the high silica margins of the pluton with values as high as δ56Fe 0.36. Additionally, the data show a decrease in δ56Fe toward the mafic center of the pluton with δ56Fe values ranging from δ56Fe -0.05 to 0.18. Samples collected on the contact between the granite and mafic complex show intermediate values of δ56Fe= 0.18(×) 0.03. Country rock samples in contact with granite show an isotopically light signature of δ56Fe=0.04 (×) 0.03. Analysis of 50 samples in total show a trend of increasing δ56Fe with SiO2 content. The process responsible for Fe isotope variations remains debated but is suggested to reflect four mechanisms: (1) crustal assimilation, (2) fractional crystallization, (3) late stage fluid exsolution [1] and (4) thermal migration [3]. Preliminary results show that mechanisms #1 and #2 would produce isotopic signatures opposite of those seen at Torres del Paine and other plutonic rocks. Isotopically light Torres country rock samples reveal that assimilation of rocks would not produce the isotopically heavy granites seen at Torres. Based on

  7. Argentine gas system underway for Gas del Estado

    SciTech Connect

    Bosch, H.

    1980-10-01

    Gas del Estado's giant 1074-mile Centro-Oeste pipeline project - designed to ultimately transport over 350 million CF/day of natural gas from the Neuquen basin to the Campo Duran-Buenos Aires pipeline system - is now underway. The COGASCO consortium of Dutch and Argentine companies awarded the construction project will also operate and maintain the system for 15 years after its completion. In addition to the 30-in. pipelines, the agreement calls for a major compressor station at the gas field, three intermediate compressor stations, a gas-treatment plant, liquids-recovery facilities, and the metering, control, communications, and maintenance equipment for the system. Fabricated in Holland, the internally and externally coated pipe will be double-jointed to 80-ft lengths after shipment to Argentina; welders will use conventional manual-arc techniques to weld the pipeline in the field.

  8. Taphonomy of guanaco bones in Tierra del Fuego

    NASA Astrophysics Data System (ADS)

    Borrero, Luis Alberto

    1990-11-01

    Guanaco carcasses are deposited in great quantities in Cabo San Pablo, Tierra del Fuego (Argentina), as a result of winter stress. Taphonomic studies indicate that the gnawing action of foxes on guanaco ( Lama guanicoe) carcasses produces only very tenuous marks on the bones. Lack of sustained interest in the carcasses by carnivores results in slow disarticulation. The articulated and disarticulated bones are exposed to heavy trampling by guanacos, a process that produces vertical migration of small/dense bones and fracturing of the most weathered bones. An understanding of this ongoing process is important for local archaeology, since modern bones are migrating into archaeological contexts. A regional approach to taphonomy is the most appropriate instrument to solve this and other related problems.

  9. Circular structures of Bajada del Diablo (Argentina): geophysical signatures

    NASA Astrophysics Data System (ADS)

    Prezzi, C. B.; Orgeira, M. J.; Martinez, O.; Acevedo, R. D.; Ponce, F.; Goldmann, G.; Magneres, I.; Rabassa, J.

    2016-05-01

    Bajada del Diablo is located in the Northern Patagonian Massif, Chubut, Argentina. The study area includes several circular structures found in Miocene olivine basalts of the Quiñelaf Eruptive Complex and in the Late Pliocene/Early Pleistocene Pampa Sastre conglomerates. An impact origin has been proposed for these circular structures. With the aim of further investigate the proposed impact origin, topographic, gravimetric, magnetic, resistivity, palaeomagnetic and electromagnetic surveys in two circular structures (`8' and `G') located in Pampa Sastre conglomerates and in basalts of the Quiñelaf Eruptive Complex were carried out. The new geophysical results support the hypothesis of an impact origin. However, the confirmation of such an origin through the findings of shock metamorphism evidences and/or the recovery of meteorites remains elusive.

  10. Renewable energy load assessment for Boquillas Del Carmen Coahuila, Mexico

    SciTech Connect

    Foster, R.

    1995-08-01

    This report outlines the estimates that were made in 1992 of the potential load requirements for Boquillas del Carmen, a small Mexican village on the northern border of the state of Coahuila, Mexico near Big Bend National Park in southern Texas. The study was made to help determine the possibility that village might be electrified by solar or wind energy. Various estimates of are given of the potential load based on estimates ranging from basic use of lights, radio, television, and small household appliances to microwave ovens, refrigerators, and direct evaporative coolers. The low-energy consumption case was estimated to be at 23.0 kWh/month per residence per month, and the high-energy consumption case (with cooling) was 140.7 kWh/month per residence. On average, the typical residence is occupied by five individuals.

  11. Ozone studies in the Paso del Norte region

    NASA Astrophysics Data System (ADS)

    Becerra-Davila, Fernando

    The Paso del Norte region forms the largest contiguous bi-national conglomerate on the US-Mexico border. With a combined population of around 2 million inhabitants, the Paso del Norte region is isolated, more than 500 km away from the nearest urban area of comparable size, thus making it an ideal location for air quality studies of an isolated urban environment. The meteorological conditions leading to a high ozone episode in this region, such as the historical ozone episode of June 2006, are analyzed. It is well known that stagnation and minimal winds, high temperatures, and pressure ridges over the region are conducive to high ozone episodes. In addition, the planetary boundary height is studied to understand its impact on high ozone episodes. Several studies report that ground level ozone non-attainment regulations could be caused not only by local emissions, but also by atmospheric transport. In this work the atmospheric advection of pollutants into the region is analyzed using HYSPLIT backward trajectories. Furthermore, a novel backward trajectory clustering technique is implemented for the summer of 2006. The "ozone weekend effect" (OWE) is a phenomenon by which in some geographical regions ambient ozone concentrations tend to be higher on weekends than on weekdays, despite the lower emissions of ozone precursors during those days. The observed local OWE has never previously been studied in terms of the photolysis rates of four of the main ozone precursors. In this research a novel method that allows the calculation of actinic fluxes, photolysis frequencies and photolysis rates with a high degree of accuracy and reliability has been developed. This method utilizes a combination of the experimental data available for this region in conjunction with a radiative transfer model (TUV model). Three weekend-weekday cases during summers 2006, 2009 and 2010 are studied in this work. In this research, the photolysis impact on the local OWE is studied. The results

  12. Phytoseiid mites (Acari: Phytoseiidae) from Patagonia and Tierra del Fuego.

    PubMed

    Ferragut, Francisco; Navia, Denise

    2015-07-28

    Predatory phytoseiid mites have been intensively studied and surveyed in the last decades because of their economic importance as biocontrol agents of agricultural pests. However, many regions of the world remain unexplored and the diversity of the family worldwide is still fragmentary. Up to date no phytoseiid species have been collected in the southernmost part of the Earth down to latitude 45º S. In this study Phytoseiidae were sampled from native vegetation in southern Argentina and Chile in the regions of Patagonia and Tierra del Fuego Island. Thirteen species were collected, five of which were previously described and eight, Chileseius australis n. sp., Neoseiulus mapuche n. sp., Typhlodromips valdivianus n. sp., T. fissuratus n. sp., Amblyseius grandiporus n. sp., A. caliginosus n. sp., Typhlodromus (Anthoseius) anomalos n. sp. and Metaseiulus parabrevicollis n. sp. are proposed as new to science and are described and diagnosed.

  13. High precision ages from the Torres del Paine Intrusion, Chile

    NASA Astrophysics Data System (ADS)

    Michel, J.; Baumgartner, L.; Cosca, M.; Ovtcharova, M.; Putlitz, B.; Schaltegger, U.

    2006-12-01

    The upper crustal bimodal Torres del Paine Intrusion, southern Chile, consists of the lower Paine-Mafic- Complex and the upper Paine-Granite. Geochronologically this bimodal complex is not well studied except for a few existing data from Halpern (1973) and Sanchez (2006). The aim of this study is to supplement the existing data and to constrain the age relations between the major magmatic pulses by applying high precision U-Pb dating on accessory zircons and 40Ar/39Ar-laser-step-heating-ages on biotites from the Torres del Paine Intrusion. The magmatic rocks from mafic complex are fine to medium-grained and vary in composition from quartz- monzonites to granodiorites and gabbros. Coarse-grained olivine gabbros have intruded these rocks in the west. The granitic body is represented by a peraluminous, biotite-orthoclase-granite and a more evolved leucocratic granite in the outer parts towards the host-rock. Field observations suggest a feeder-zone for the granite in the west and that the granite postdates the mafic complex. Two granite samples of the outermost margins in the Northeast and South were analyzed. The zircons were dated by precise isotope-dilution U-Pb techniques of chemically abraded single grains. The data are concordant within the analytical error and define weighted mean 206/238U ages of 12.59 ± 0.03 Ma and 12.58 ± 0.01 Ma for the two samples respectively. A 40Ar/39Ar-age for the second sample yield a date of 12.37 ± 0.11 Ma. Three 40Ar/39Ar -ages of biotites were obtained for rocks belonging to the mafic complex. A hbl-bio- granodiorite from the central part, approximately 150 m below the subhorizontal contact with the granite, gives an age of 12.81 ± 0.11 Ma. A hbl-bio-granodiorite and an olivine-gabbro west of the feeder-zone date at 12.42 ± 0.14 Ma and 12.49 ± 0.11 Ma, respectively. The obtained older age of 12.81 Ma for the granodiorite in the central part is consistent with structural relationships of brittle fracturing of the mafic

  14. Volcanic hazard maps of the Nevado del Ruiz volcano, Colombia

    NASA Astrophysics Data System (ADS)

    Parra, Eduardo; Cepeda, Hector

    1990-07-01

    Although the potential hazards associated with an eruption of Nevado del Ruiz volcano were known to civil authorities before the catastrophic eruption there in November 1985, their low perception of risk and the long quiescent period since the last eruption (140 years), caused them to wait for stronger activity before developing an eruption alert system. Unfortunately, the eruption occurred suddenly after a period of relative quiet, and as a result more than 25,000 people were killed. Although it was accurate and reasonably comprehensive, the hazard map that existed before the eruption was poorly understood by the authorities and even less so by the general population, because the scientific terminology and probabilistic approach to natural hazards were unfamiliar to many of them. This confusion was shared by the communication media, which at critical times placed undue emphasis on the possibility of lava flows rather than on the more imminent threat from mudflows, in keeping with the popular but often inaccurate perception of volcanic eruptions. This work presents an updated hazard map of Nevado del Ruiz that combines information on various hazardous phenomena with their relative probability of occurrence in order to depict numerical "hazard levels" that are easily comprehensible to nonspecialists and therefore less susceptible to misinterpretation. The scale of relative risk is arbitrary, ranging from five to one, and is intended to provide an intuitive indication of danger to people, property and crops. The map is meant to facilitate emergency preparedness and management by political and civil authorities, to educate the public concerning volcanic hazards and to assist in land-use planning decisions.

  15. [Epidemiology of dog bite lesions in Tierra del Fuego, Argentina].

    PubMed

    Zanini, Fabián; Padinger, Patricia; Elissondo, María C; Pérez, Héctor

    2008-01-01

    The coexistence between man and dog has resulted in mutual benefits during thousands of years, nevertheless some problems have recently arisen where bite injuries have an important role. The aim of this work was to describe the epidemiological characteristics of dog bite lesions which occurred during a year in Tierra del Fuego. A descriptive observational, transversal study of patients who were admitted with dog bite injuries to clinic and pediatric emergency services of hospitals and health centers was carried out between 3/1/05 and 3/1/06. A total of 382 records were made. The children group represents 49.5%. The group between 5 and 9 year-old was the most affected (44.4%; IC95% 37.2-51.8). In the adult group, that between 15 and 24 year-old was the most affected (29.5%; IC95% 23.2-36.5). More lesions were registered in men (57.6%) than in women (42.4%) (chi2 = 8.6, p = 0.003). During spring and summer months, 56.5% of the lesions were registered. A 72.8% of the incidents occurred on the public highway. Dogs of big size were responsible of 49.7% (IC95% 44.6-54.9) of the injuries. The 89.8% of the incidents were caused by another person's dog. Of the lesions, 55.8% (IC95% 50.6-60.8) were registered in lower extremities and 11% (IC95% 8.1-14.7) in head and neck. These data show that dog bite lesions affect the health and impact in the quality of life of the population of Tierra del Fuego, Argentina.

  16. Deficiency of developmental endothelial locus-1 (Del-1) aggravates bleomycin-induced pulmonary fibrosis in mice.

    PubMed

    Kang, Yoon-Young; Kim, Dong-Young; Lee, Seung-Hwan; Choi, Eun Young

    2014-03-07

    Pulmonary fibrosis is a lung disease wherein lung parenchyma is gradually and irreversibly replaced with collagen. The molecular pathogenesis of pulmonary fibrosis is not fully understood and the only effective treatment available is lung transplantation. To test if Del-1, an endogenous anti-inflammatory molecule, may be implicated in the development of pulmonary fibrosis, we induced pulmonary fibrosis in wild type (WT) and Del-1(-/-) mice by intratracheal administration of bleomycin. Del-1 expression in the lung was decreased in the WT mice treated with bleomycin compared to control mice. In addition, bleomycin-induced pulmonary fibrosis increased collagen deposition and TGF-β production in the lung of Del-1(-/-) mice. Finally, Del-1(-/-) mice treated with bleomycin displayed higher weight loss and greater mortality than did WT mice identically treated. These findings suggest that Del-1 may negatively regulate development of pulmonary fibrosis. Further delineation of a role for Del-1 in the development of pulmonary fibrosis will broaden our understanding of the molecular pathogenesis of this disease and hopefully help develop potential therapeutics.

  17. Max Brödel: his art, legacy, and contributions to neurosurgery through medical illustration.

    PubMed

    Patel, Smruti K; Couldwell, William T; Liu, James K

    2011-07-01

    Max Brödel is considered the father of modern medical illustration. This report reviews his contributions to neurosurgery as a medical illustrator. Max Brödel, a young artist from Leipzig, Germany, was hired at Johns Hopkins Hospital in 1894, where he illustrated an operative textbook of gynecology for Howard A. Kelly. Although Brödel did not have any formal medical training, he quickly acquired knowledge of anatomy, pathology, physiology, and surgery. Brödel's extraordinary illustrations were characterized by an aerial perspective that conveyed the surgeon's operative viewpoint and precise surgical anatomy. He masterfully incorporated tissue realism with cross-sectional anatomy to accentuate concepts while maintaining topographical accuracy. Brödel's reputation spread quickly and resulted in collaborations with prominent surgeons, such as Cushing, Halsted, and Dandy. Cushing, who also possessed artistic talent, became a pupil of Brödel and remained a very close friend. In 1911, Brödel was appointed the director of the Department of Art as Applied to Medicine at Johns Hopkins, the first academic department of its kind in the world. For the next several decades, he trained generations of renowned medical illustrators. Just as Osler, Halsted, and Cushing passed their skills and knowledge to future leaders of medicine and surgery, Brödel did the same for the field of medical illustration. The advancement of neurosurgical education has been greatly facilitated by Max Brödel's artistic contributions. His unique ability to synthesize art and medicine resulted in timeless illustrations that remain indispensable to surgeons. The art produced by his legacy of illustrators continues to flourish in neurosurgical literature today.

  18. Max Brödel's contributions to otolaryngology-head and neck surgery.

    PubMed

    Papel, I D

    1986-11-01

    Max Brödel arrived in the United States in 1894 to work as a medical illustrator at the Johns Hopkins Hospital. He brought with him an extensive background in medical sciences and illustration. This allowed him to develop an advanced style and technique that would greatly influence the profession of medical illustration. Much of Brödel's work concerned the head and neck region and is of particular interest to otolaryngologists. This article reviews the historical aspects of Brödel's career and highlights his contributions to Otolaryngology-Head and Neck Surgery.

  19. Spatial shell structure of the novas DQ Her and HR Del

    SciTech Connect

    Pilyogin, L.S.

    1986-03-01

    This paper considers the formation of the spatial shell structure of the novas DQ Her (1934) and HR Del (1967). It is shown that the existence of polar caps is due to the influence of the second component of the system on the angular distribution of the mass shell depth of the mainshell. The ratio of the mass shell depth in the equatorial ring and in the polar caps is 1.13 for DQ Her and 2.7 for HR Del. The ratio of the maximal densities in the equatorial ring and the polar caps is of order 3 for DQ Her and of order 70 for HR Del.

  20. Resultados del relevamiento de HI en el Cielo Austral: 3. Relevamiento de Nubes de Alta Velocidad

    NASA Astrophysics Data System (ADS)

    Morras, R.; Bajaja, E.; Arnal, E. M.; Pöppel, W. G. L.

    Los resultados del relevamiento de HI del Hemisferio Austral fueron reprocesados con el fin de incrementar su sensibilidad. Así, se utilizó esta nueva base de datos con el fin de obtener un nuevo relevamiento de Nubes de Alta Velocidad en el cielo austral. El ruido r.m.s. alcanzado es de 0.015-0.020 K, con una resolución espectral de 8 km/seg. El cubrimiento espacial del relevamiento mejora en un factor 16 al realizado por Bajaja et al (1985).

  1. A Silicate Inclusion in Puente del Zacate, a IIIA Iron Meteorite

    NASA Astrophysics Data System (ADS)

    Olsen, Edward J.; Davis, Andrew M.; Clayton, Robert N.; Mayeda, Toshiko K.; Moore, Carleton B.; Steele, Ian M.

    1996-09-01

    The IIIA and IIIB iron meteorites are considered to have formed in the cores of asteroids. A silicate inclusion within the IIIA meteorite Puente del Zacate consisting of olivine (Fa_4), low-calcium pyroxene (Fs_6Wo_1), chromium diopside (Fs_3Wo47), plagioclase (An14Or_4), graphite, troilite, chromite, daubreelite, and iron metal resembles inclusions in IAB iron meteorites. The oxygen isotopic composition of the Puente del Zacate inclusion is like chromite and phosphate inclusions in other IIIA and IIIB irons. The Puente del Zacate inclusion may have been derived from the lower mantle of the IIIAB parent asteroid.

  2. Fermions in Gödel-type background space-times with torsion and the Landau quantization

    NASA Astrophysics Data System (ADS)

    Garcia, G. Q.; de S. Oliveira, J. R.; Bakke, K.; Furtado, C.

    2017-03-01

    In this paper, we analyze Dirac fermions in Gödel-type background space-times with torsion. We also consider the Gödel-type space-times embedded in a topological defect background. We show that relativistic bound states solutions to the Dirac equation can be obtained by dealing with three cases of the Gödel-type solutions with torsion, where a cosmic string passes through these three cases of the space-time. We obtain the relativistic energy levels for all cases of the Gödel-type solutions with torsion with a cosmic string, where we show that there exists an analogy with the Landau levels for Dirac particles. We also show that the presence of torsion in the space-time yields new contributions to the relativistic spectrum of energies and that the presence of the topological defect modifies the degeneracy of the relativistic energy levels.

  3. Eleven new cases of del(9p) and features from 80 cases.

    PubMed Central

    Huret, J L; Leonard, C; Forestier, B; Rethoré, M O; Lejeune, J

    1988-01-01

    We report 11 cases of del(9p) and review 69 previously published ones. Of the 80 cases, 39 have a del(9p) as the sole anomaly. The symptoms are typical and diagnosis should be suspected at birth. The sex ratio does not appear to be unbalanced. A cardiac murmur is often present but surgery is rarely necessary. Mean IQ is 48. The number of reported cases with an associated trisomy has previously been underestimated. Death in infancy, owing mainly to gross visceral malformations, occurs more often in cases of del(9p) with another unbalanced chromosome segment (16/41) than in cases of del(9p) as the sole anomaly (1/39). Images PMID:3070043

  4. Taos Smart Growth Implementation Assistance: Concepts for the Paseo del Pueblo Sur Corridor

    EPA Pesticide Factsheets

    This report describes a technical assistance project with Taos, NM, to help make development along State Highway 68, the Paseo del Pueblo Sur commercial corridor, economically stronger and more attractive.

  5. Energy and Momentum in Spacetime Homogeneous GÖDEL-TYPE Metrics

    NASA Astrophysics Data System (ADS)

    Sharif, M.

    Using Einstein and Papapetrou energy-momentum complexes, we explicitly calculate the energy and momentum distribution associated with spacetime homogeneous Gödel-type metrics. We obtain that the two definitions of energy-momentum complexes do not provide the same result for these type of metrics. However, it is shown that the results obtained are reduced to the energy-momentum densities of Gödel metric already available in the literature.

  6. Exact Solution of the Massless Dkp Equation in a Nonstationary GÖDEL-TYPE Cosmological Universe

    NASA Astrophysics Data System (ADS)

    Havare, Ali; Aydogdu, Oktay; Yetkin, Taylan

    In this paper the massless Duffin-Kemmer-Petiau equation in a nonstationary rotating, causal Gödel-type cosmological background is studied. Exact solutions of the corresponding field equation are obtained and used to calculate the frequency spectrum of photon in nonstationary Gödel-type universe. To compare the results found with the classical field solutions, we also solved Maxwell's equations as given in the appendix.

  7. Estudio multiespectral del remanente de supernova W 28

    NASA Astrophysics Data System (ADS)

    Dubner, G.; Velázquez, P.; Castelletti, G.

    Se presentan observaciones en continuo de radio con muy alta resolución angular y sensibilidad del remanente de supernova (RSN) W28. Las observaciones fueron realizadas con el interferómetro Very Large Array (Estados Unidos), en las configuraciones C y D, en 1415 y 324 MHz. Por la gran extensión de este remanente (diámetro ~ 1o), las observaciones en 1415 MHz se realizaron en modo mosaico, combinando 48 apuntamientos diferentes en una única imagen. En ambas frecuencias los datos se procesaron con el agregado de observaciones de menor resolución angular, a fin de recuperar información en todas las frecuencias espaciales y obtener estimaciones precisas de densidad de flujo. Las imágenes resultantes muestran por primera vez la presencia de extensiones con forma de arco, cuya naturaleza se investiga. Las observaciones en radio se comparan con una imagen óptica de W28, y con la emisión en rayos X, observada con el satélite ROSAT. Este remanente muestra una clara morfología híbrida, tipo cáscara en frecuencias de radio y de centro lleno en las bandas óptica y de rayos X blandos.

  8. Seismicity following the 1985 eruption of Nevado del Ruiz, Colombia

    USGS Publications Warehouse

    Zollweg, J.E.

    1990-01-01

    Over 200 of the best-recorded earthquakes occurring near Nevado del Ruiz, Colombia, between December 1985 and May 1986 are examined for spatial patterns, information on local stress orientations, and evidence for seismogenic structures that may be related to magma-transport processes. These earthquakes occurred following the devastating eruption of November 13, 1985. Earthquake activity that is probably related to the volcanic system occurs over a large area, of the order of 50 km2. A pattern of earthquakes beneath the southern half of Ruiz may be the expression of a conduit system, but evidence is inconclusive due to low spatial resolution of most hypocenters. Epicenter and first-motion plots suggest most earthquakes occur on small faults of varying orientation. Most seismicity during this time period was unrelated to mapped faults, including some with Holocene offsets, except for the Villamaria Fault near Ruiz's northeast sector. Composite focal mechanisms show a variation of nearly 90?? in the strike of T-axes and indicate Ruiz is in a zone of local extension. ?? 1990.

  9. Paso del Norte ozone study VOC measurements, 1996

    SciTech Connect

    Seila, R.L.; Main, H.; Arriaga, J.L.; Martinez, G.V.; Ramadan, A.B.

    1999-01-01

    The results of VOC determinations of ambient air samples collected at surface air quality monitoring sites and near sources of interest on the US and Mexican side of the border during six weeks of the 1996 Paso del Norte Ozone Study are reported. Carbonyl samples were collected on DNPH impregnated cartridges at three surface sites and analyzed by HPLC to quantify 13, C-1 to C-8 species. Whole air samples were collected in electro-polished stainless steel canisters which were returned to laboratory for determination of C-2 to C-10+ hydrocarbons by cryogenic preconcentration capillary gas chromatography with flame ionization detection (gc-fid). Several sources were sampled: rush hour traffic, propane-powered bus exhaust, automobile paint shop emissions, propane fuel, petroleum refinery, and industrial manufacturing site. Spatial and temporal characteristics of VOC species concentrations and compositions are presented. Overall surface TNMOC values ranged from 0.1 to 3.4 ppmC with the highest concentrations recorded in the morning at three vehicle-dominated sites, two in Cuidad Juarez and one in downtown El Paso. Toluene in El Paso samples and propane, which is used as a cooking and transportation fuel in Cuidad Juarez, were the most abundant hydrocarbons.

  10. Paso del Norte ozone study VOC measurements, 1996

    SciTech Connect

    Seila, R.L.; Main, H.; Arriaga, J.L.; Martinez, G.V.; Ramadan, A.B.

    1999-11-01

    The results of VOC determinations of ambient air samples collected at surface air quality monitoring sites and near sources of interest on the US and Mexican side of the border during six weeks of the 1996 Paso del Norte Ozone Study are reported. Carbonyl samples were collected on DNPH impregnated cartridges at three surface sites and analyzed by HPLC to quantify 13, C-1 to C-8 species. Whole air samples were collected in electro-polished stainless steel canisters which were returned to laboratory for determination of C-2 to C-10+ hydrocarbons by cryogenic preconcentration capillary gas chromatography with flame ionization detection (gc-fid). Several sources were sampled: rush hour traffic, propane-powered bus exhaust, automobile paint shop emissions, propane fuel, petroleum refinery, and industrial manufacturing site. Spatial and temporal characteristics of VOC species concentrations and compositions are presented. Overall surface TNMOC values ranged from 0.1 to 3.4 ppmC with the highest concentrations recorded in the morning at three vehicle-dominated sites, two in Cuidad Juarez and one in downtown El Paso. Toluene in El Paso samples and propane, which is used as a cooking and transportation fuel in Cuidad Juarez, were the most abundant hydrocarbons.

  11. ``Campo del Cielo'' Meteorites: Astronomical Heritage and Cultural Colonialism

    NASA Astrophysics Data System (ADS)

    López, Alejandro Martín; Altman, Agustina

    2012-09-01

    In the province of Chaco, Argentina, there is a very unique dispersion of metallic meteorites called ``Campo del Cielo''. One of the meteoric fragments of this dispersion, the meteorite called ``El Chaco'', consisting of 37 tons, is the second heaviest in the world. These meteorites are of great importance to the worldview of the Moqoit, aboriginal people that inhabit this region. For the local Creole population the meteorites are also relevant, that's why they have being cited in numerous documents and reports since the colonial period. During the first months of 2012, two Argentine artists and the Artistic Director of the German contemporary art exhibition called dOCUMENTA (13) tried to move ``El Chaco'' meteorite to Germany in order to exhibit it as an artistic object. Due to the fact that moving the meteorite could have a negative impact according to the Moqoit cosmology and that they were not able to participate in the decision they begun a manifestation against the movement of El Chaco. The opposition made by aboriginal communities and experts in cultural astronomy was able to stop the transfer. The whole process and its impact on the local community have promoted a deep discussion about art, science and cultural colonialism. In this paper we aim to address this debate and its consequences. This will allow us to think about contemporary forms of colonialism that are hidden in many scientific and artistic projects. Furthermore, we aim to debate about the most effective ways of protecting astronomical heritage in the Third World.

  12. MALARIA VECTORS IN SAN JOSÉDEL GUAVIARE, ORINOQUIA, COLOMBIA

    PubMed Central

    JIMÉNEZ, IRENE P.; CONN, JAN E.; BROCHERO, HELENA

    2015-01-01

    This study was conducted to determine Anopheles species composition and their natural infectivity by human Plasmodium in 2 localities with the highest malaria transmission in San Jose del Guaviare, Guaviare, Colombia. A total of 1,009 Anopheles mosquitoes were collected using human landing catches during 8 months in 2010. Anopheles darlingi was the most abundant (83.2%) followed by An. albitarsis s.l. (8.6%), Anopheles braziliensis (3.8%), An. oswaldoi s.l. (1%), and An. rangeli (0.3%). Anopheles darlingi showed the highest human biting rate, and it was found naturally infected with Plasmodium vivax VK210 (0.119%) using enzyme-linked immunosorbent assays. All species were collected biting both indoors and outdoors. Anopheles darlingi showed biting activity overnight with an indoor peak between 1200–0100 h. Therefore, we recommend that malaria prevention strategies focus on 1) insecticide-treated nets to reduce human–vector contact when people are most exposed and unprotected; 2) accurate diagnoses; 3) adequate treatment for patients; 4) more timely epidemiological notification; and 5) improved entomological surveillance. PMID:25102591

  13. CHEK2 c.1100delC allele is rarely identified in Greek breast cancer cases.

    PubMed

    Apostolou, Paraskevi; Fostira, Florentia; Papamentzelopoulou, Myrto; Michelli, Maria; Panopoulos, Christos; Fountzilas, George; Konstantopoulou, Irene; Voutsinas, Gerassimos E; Yannoukakos, Drakoulis

    2015-04-01

    The CHEK2 gene encodes a protein kinase that plays a crucial role in maintenance of genomic integrity and the DNA repair mechanism. CHEK2 germline mutations are associated with increased risk of breast cancer and other malignancies. From a clinical perspective, the most significant mutation identified is the c.1100delC mutation, which is associated with an approximately 25% lifetime breast cancer risk. The distribution of this mutation shows wide geographical variation; it is more prevalent in the Northern European countries and less common, or even absent, in Southern Europe. In order to estimate the frequency of the CHEK2 c.1100delC mutation in Greek breast cancer patients, we genotyped 2,449 patients (2,408 females and 41 males), which was the largest series ever tested for c.1100delC. The mean age of female and male breast cancer diagnosis was 49 and 59 years, respectively. All patients had previously tested negative for the Greek BRCA1 founder and recurrent mutations. The CHEK2 c.1100delC mutation was detected in 0.16% (4 of 2,408) of females, all of whom were diagnosed with breast cancer before the age of 50 years. Only one c.1100delC carrier was reported with breast cancer family history. The present study indicates that the CHEK2 c.1100delC mutation does not contribute substantially to hereditary breast cancer in patients of Greek descent.

  14. Multi-InDel Analysis for Ancestry Inference of Sub-Populations in China

    PubMed Central

    Sun, Kuan; Ye, Yi; Luo, Tao; Hou, Yiping

    2016-01-01

    Ancestry inference is of great interest in diverse areas of scientific researches, including the forensic biology, medical genetics and anthropology. Various methods have been published for distinguishing populations. However, few reports refer to sub-populations (like ethnic groups) within Asian populations for the limitation of markers. Several InDel loci located very tightly in physical positions were treated as one marker by us, which is multi-InDel. The multi-InDel shows potential as Ancestry Inference Marker (AIM). In this study, we performed a genome-wide scan for multi-InDels as AIM. After examining the FST distributions in the 1000 Genomes Database, 12 candidates were selected and validated for eastern Asian populations. A multiplexed assay was developed as a panel to genotype 12 multi-InDel markers simultaneously. Ancestry component analysis with STRUCTURE and principal component analysis (PCA) were employed to estimate its capability for ancestry inference. Furthermore, ancestry assignments of trial individuals were conducted. It proved to be very effective when 210 samples from Han and Tibetan individuals in China were tested. The panel consisting of multi-InDel markers exhibited considerable potency in ancestry inference, and was suggested to be applied in forensic practices and genetic population studies. PMID:28004788

  15. Unravelling druggable signalling networks that control F508del-CFTR proteostasis

    PubMed Central

    Hegde, Ramanath Narayana; Parashuraman, Seetharaman; Capuani, Fabrizio; Carissimo, Annamaria; Carrella, Diego; Belcastro, Vincenzo; Subramanian, Advait; Bounti, Laura; Persico, Maria; Carlile, Graeme; Galietta, Luis; Thomas, David Y; Di Bernardo, Diego; Luini, Alberto

    2015-01-01

    Cystic fibrosis (CF) is caused by mutations in CF transmembrane conductance regulator (CFTR). The most frequent mutation (F508del-CFTR) results in altered proteostasis, that is, in the misfolding and intracellular degradation of the protein. The F508del-CFTR proteostasis machinery and its homeostatic regulation are well studied, while the question whether ‘classical’ signalling pathways and phosphorylation cascades might control proteostasis remains barely explored. Here, we have unravelled signalling cascades acting selectively on the F508del-CFTR folding-trafficking defects by analysing the mechanisms of action of F508del-CFTR proteostasis regulator drugs through an approach based on transcriptional profiling followed by deconvolution of their gene signatures. Targeting multiple components of these signalling pathways resulted in potent and specific correction of F508del-CFTR proteostasis and in synergy with pharmacochaperones. These results provide new insights into the physiology of cellular proteostasis and a rational basis for developing effective pharmacological correctors of the F508del-CFTR defect. DOI: http://dx.doi.org/10.7554/eLife.10365.001 PMID:26701908

  16. Unravelling druggable signalling networks that control F508del-CFTR proteostasis.

    PubMed

    Hegde, Ramanath Narayana; Parashuraman, Seetharaman; Iorio, Francesco; Ciciriello, Fabiana; Capuani, Fabrizio; Carissimo, Annamaria; Carrella, Diego; Belcastro, Vincenzo; Subramanian, Advait; Bounti, Laura; Persico, Maria; Carlile, Graeme; Galietta, Luis; Thomas, David Y; Di Bernardo, Diego; Luini, Alberto

    2015-12-23

    Cystic fibrosis (CF) is caused by mutations in CF transmembrane conductance regulator (CFTR). The most frequent mutation (F508del-CFTR) results in altered proteostasis, that is, in the misfolding and intracellular degradation of the protein. The F508del-CFTR proteostasis machinery and its homeostatic regulation are well studied, while the question whether 'classical' signalling pathways and phosphorylation cascades might control proteostasis remains barely explored. Here, we have unravelled signalling cascades acting selectively on the F508del-CFTR folding-trafficking defects by analysing the mechanisms of action of F508del-CFTR proteostasis regulator drugs through an approach based on transcriptional profiling followed by deconvolution of their gene signatures. Targeting multiple components of these signalling pathways resulted in potent and specific correction of F508del-CFTR proteostasis and in synergy with pharmacochaperones. These results provide new insights into the physiology of cellular proteostasis and a rational basis for developing effective pharmacological correctors of the F508del-CFTR defect.

  17. Use of multi-InDels as novel markers to analyze 13 X-chromosome haplotype loci for forensic purposes.

    PubMed

    Fan, Guangyao; Ye, Yi; Luo, Haibo; Hou, Yiping

    2015-12-01

    Many studies have been proposed to identify insertion/deletion (InDel) polymorphisms in humans for forensic genetic studies. However, the discriminatory power of InDels is limited by the poor polymorphisms of diallelic markers. To improve their discriminatory power, we developed multi-InDel, a novel autosomal marker comprising more than two InDel loci that are tightly linked by their physical position and combined into a specific marker by a pair of PCR primers. This strategy gives at least three haplotypes for each multi-InDel marker. Such markers can be potentially very useful in forensic applications. In this study, we focused on multi-InDel markers located on X chromosome (ChrX). A multiplex system with 13 multi-InDel markers, including 28 InDel loci in ChrX, was developed. To validate the multi-InDel panel, the haplotype distribution in a population sample and in a set of pedigrees was investigated. This study demonstrates usefulness of these markers for individual identification and relationship studies. We highlight the fact that the multi-InDel markers located on ChrX can provide new supporting information for complex kinship testing.

  18. Resistivity structure of the Del Mar methane seep.

    NASA Astrophysics Data System (ADS)

    Kannberg, P. K.; Constable, S.

    2015-12-01

    In March of 2015 we mapped the resistivity structure of the Del Mar methane seep in the inner California borderlands using a deep towed electromagnetic (EM) source and receiver array. Located in the San Diego trough at a depth of 1km, the seep site is on the flank of a mound associated with a transpressive step in the San Diego trough fault. The seep site has previously been associated with seafloor pockmarks, acoustic wipeouts, chemosynthetic communities, and active methane bubble venting. Controlled source electromagnetic (CSEM) surveys are performed by deep-towing an EM source that is transmitting a known signal; this signal is detected by towed receivers. This transmitted signal is altered by the electrical properties of the surrounding environment. Compared to seismic methods, EM methods are largely insensitive to free gas, making it an especially useful tool for detecting electrically resistive methane hydrate in areas of active gas venting. We used a 50m dipole transmitting 100A, with 3-axis electric field receivers spaced at 130m, 230m, 330m, and 430m behind the transmitter dipole center. The receiver data are inverted using MARE2DEM, a finite element 2D inversion routine. The inversion results show the background resistivity of the trough sediments to be about 1-2 ohmm, and are largely featureless outside of the seep site. However at the seep site we see a decanter-shaped 100 ohmm resistor whose base is 100m below the seafloor, and 1km wide at its widest. This feature narrows at the top to form a pipe structure about 200m wide that extends to the seafloor. These resistive structures are interpreted to be methane hydrate resulting from methane rich fluid flow along faults associated with the transpressional system that brackets the seep site.

  19. 1996 Paso del Norte ozone study VOC measurements

    SciTech Connect

    Seila, R.L.; Main, H.; Arriaga, J.L.; Martinez, G.; Ramadan, A.B.

    1999-07-01

    Ambient air VOC samples were collected at surface air quality monitoring sites, near sources of interest, and aloft on the US and Mexican side of the border during a six week period of the 1996 Paso del Norte Ozone Study. On nine intensive operations (IOP) days, when high ozone concentrations were forecast, five 2-hr samples were collected at five IOP sites, three on the US side and two on the Mexican side. Six special survey sites on the US side and two on the Mexican side were sampled to characterize up-wind, down-wind and other emissions. In Ciudad Juarez, rush hour traffic, propane-powered bus exhaust, automobile paint shop emissions, propane and butane fuels, and an industrial manufacturing site were sampled. Carbonyl samples were collected at three surface sites. Carbonyl and canister grab samples were also collected during aircraft and hot air balloon flights. Most of the hydrocarbon samples were collected in electro-polished stainless steel canisters which were returned to laboratories for determination of C-2 to C-10+ hydrocarbons by cryogenic preconcentration GC-FID. The carbonyl samples were collected on DNPH impregnated C-18 Sep-Pak cartridges and analyzed by HPLC to quantify 13, C-1 to C-8 species. This paper presents the spatial and temporal characteristics of VOC species concentrations and compositions to examine the differences and similarities of the various locations and time periods. Overall surface TNMOC values ranged from 0.1 to 3.4 ppmC with the highest concentrations being recorded in the morning at three vehicle-dominated sites, two in Ciudad Juarez and one in downtown El Paso. Toluene in El Paso samples and propane, which is used as a cooking and transportation fuel in Ciudad Juarez, were the most abundant hydrocarbons. The most abundant carbonyls were acetaldehyde and acetone.

  20. Telomere dynamics in patients with del (5q) MDS before and under treatment with lenalidomide.

    PubMed

    Beier, Fabian; Masouleh, Behzad Kharabi; Buesche, Guntram; Ventura Ferreira, Monica S; Schneider, Rebekka K; Ziegler, Patrick; Wilop, Stefan; Vankann, Lucia; Gattermann, Norbert; Platzbecker, Uwe; Giagounidis, Aristoteles; Götze, Katharina S; Nolte, Florian; Hofmann, Wolf-Karsten; Haase, Detlef; Kreipe, Hans; Panse, Jens; Blasco, Maria A; Germing, Ulrich; Brümmendorf, Tim H

    2015-09-21

    Myelodysplastic syndrome (MDS) associated with an acquired, isolated deletion of chromosome 5q (del (5q) MDS), represent a clonal disorder of hematopoiesis and a clinically distinct entity of MDS. Treatment of del (5q) MDS with the drug lenalidomide has significantly improved quality of life leading to transfusion independence and complete cytogenetic response rates (CCR) in the majority of patients. Telomeres are located at the end of eukaryotic chromosomes and are linked to replicative history/potential as well as genetic (in) stability of hematopoietic stem cells. Here, we analyzed telomere length (TL) dynamics before and under lenalidomide treatment in the peripheral blood and/or bone marrow of del (5q) patients enrolled in the LEMON-5 study (NCT01081431). Hematopoietic cells from del (5q) MDS patients were characterized by significantly shortened TL compared to age-matched healthy controls. Telomere loss was more accelerated in patients with longer disease duration (>2 years) and more pronounced cytopenias. Sequential analysis under lenalidomide treatment revealed that previously shortened TL in peripheral blood cells was significantly "elongated" towards normal levels within the first six months suggesting a shift from clonal del (5q) cells towards normal hematopoiesis in lenalidomide treated MDS patients. Taken together our findings suggest that the development of the del (5q) clone is associated with accelerated telomere shortening at diagnosis. However, upon induction of CCR and reoccurrence of normal hematopoiesis, the lack of a persistent TL deficit argues against telomere-mediated genetic instability neither as a disease-promoting event of del (5q) MDS nor for lenalidomide mediated development of secondary primary malignancies of the hematopoietic system in responding patients.

  1. Genetic modifiers of CHEK2*1100delC associated breast cancer risk

    PubMed Central

    Muranen, Taru A.; Greco, Dario; Blomqvist, Carl; Aittomäki, Kristiina; Khan, Sofia; Hogervorst, Frans; Verhoef, Senno; Pharoah, Paul D.P.; Dunning, Alison M.; Shah, Mitul; Luben, Robert; Bojesen, Stig E.; Nordestgaard, Børge G.; Schoemaker, Minouk; Swerdlow, Anthony; García-Closas, Montserrat; Figueroa, Jonine; Dörk, Thilo; Bogdanova, Natalia V.; Hall, Per; Li, Jingmei; Khusnutdinova, Elza; Bermisheva, Marina; Kristensen, Vessela; Borresen-Dale, Anne-Lise; Peto, Julian; dos Santos Silva, Isabel; Couch, Fergus J.; Olson, Janet E.; Hillemans, Peter; Park-Simon, Tjoung-Won; Brauch, Hiltrud; Hamann, Ute; Burwinkel, Barbara; Marme, Frederik; Meindl, Alfons; Schmutzler, Rita K.; Cox, Angela; Cross, Simon S.; Sawyer, Elinor J.; Tomlinson, Ian; Lambrechts, Diether; Moisse, Matthieu; Lindblom, Annika; Margolin, Sara; Hollestelle, Antoinette; Martens, John W.M.; Fasching, Peter A.; Beckmann, Matthias W.; Andrulis, Irene L.; Knight, Julia A.; Anton-Culver, Hoda; Ziogas, Argyrios; Giles, Graham G.; Milne, Roger L.; Brenner, Hermann; Arndt, Volker; Mannermaa, Arto; Kosma, Veli-Matti; Chang-Claude, Jenny; Rudolph, Anja; Devilee, Peter; Seynaeve, Caroline; Hopper, John L.; Southey, Melissa C.; John, Esther M.; Whittemore, Alice S.; Bolla, Manjeet K.; Wang, Qin; Michailidou, Kyriaki; Dennis, Joe; Easton, Douglas F.; Schmidt, Marjanka K.; Nevanlinna, Heli

    2016-01-01

    Purpose CHEK2*1100delC is a founder variant in European populations conferring a 2–3 fold increased risk of breast cancer (BC). Epidemiologic and family studies have suggested that the risk associated with CHEK2*1100delC is modified by other genetic factors in a multiplicative fashion. We have investigated this empirically using data from the Breast Cancer Association Consortium (BCAC). Methods With genotype data of 39,139 (624 1100delC carriers) BC patients and 40,063 (224) healthy controls from 32 BCAC studies, we analyzed the combined risk effects of CHEK2*1100delC and 77 common variants in terms of a polygenic risk score (PRS) and pairwise interaction. Results The PRS conferred an odds ratio (OR) of 1.59 [95% CI 1.21–2.09] per standard deviation for BC for CHEK2*1100delC carriers and 1.58 [1.55–1.62] for non-carriers. No evidence for deviation from the multiplicative model was found. The OR for the highest quintile of the PRS was 2.03 [0.86–4.78] for CHEK2*1100delC carriers placing them to the high risk category according to UK NICE guidelines. OR for the lowest quintile was 0.52 [0.16–1.74], indicating life-time risk close to population average. Conclusion Our results confirm the multiplicative nature of risk effects conferred by CHEK2*1100delC and the common susceptibility variants. Furthermore, the PRS could identify the carriers at a high life-time risk for clinical actions. PMID:27711073

  2. Manipulating proteostasis to repair the F508del-CFTR defect in cystic fibrosis.

    PubMed

    Esposito, Speranza; Tosco, Antonella; Villella, Valeria R; Raia, Valeria; Kroemer, Guido; Maiuri, Luigi

    2016-12-01

    Cystic fibrosis (CF) is a lethal monogenic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that entails the (diagnostic) increase in sweat electrolyte concentrations, progressive lung disease with chronic inflammation and recurrent bacterial infections, pancreatic insufficiency, and male infertility. Therapies aimed at restoring the CFTR defect have emerged. Thus, a small molecule which facilitates chloride channel opening, the potentiator Ivacaftor, has been approved for the treatment of CF patients bearing a particular class of rare CFTR mutations. However, small molecules that directly target the most common misfolded CFTR mutant, F508del, and improve its intracellular trafficking in vitro, have been less effective than expected when tested in CF patients, even in combination with Ivacaftor. Thus, new strategies are required to circumvent the F508del-CFTR defect. Airway and intestinal epithelial cells from CF patients bearing the F508del-CFTR mutation exhibit an impressive derangement of cellular proteostasis, with oxidative stress, overactivation of the tissue transglutaminase (TG2), and disabled autophagy. Proteostasis regulators such as cysteamine can rescue and stabilize a functional F508del-CFTR protein through suppressing TG2 activation and restoring autophagy in vivo in F508del-CFTR homozygous mice, in vitro in CF patient-derived cell lines, ex vivo in freshly collected primary patient's nasal cells, as well as in a pilot clinical trial involving homozygous F508del-CFTR patients. Here, we discuss how the therapeutic normalization of defective proteostasis can be harnessed for the treatment of CF patients with the F508del-CFTR mutation.

  3. [Guideline for the assessment of clinical research proposals. Comisión Nacional de Investigación Científica del Instituto Mexicano del Seguro Social].

    PubMed

    Mejía-Aranguré, Juan Manuel; Grijalva-Otero, Israel; Majluf-Cruz, Abraham; Cruz-López, Miguel; Núñez-Enríquez, Juan Carlos; Salamanca-Gómez, Fabio Abdiel

    2013-01-01

    Antecedentes: la investigación médica es una herramienta fundamental para lograr el avance de la ciencia al mejorar las acciones encaminadas a proteger, promover y restaurar la salud del individuo y de la sociedad en general. Las tres características imprescindibles para que un protocolo de investigación sea autorizado son: relevancia científica, calidad técnica y el cumplimiento de los aspectos éticos. Material y métodos: estudio retrospectivo efectuado con base en la búsqueda específica en Pubmed, Medline, Ovid y Google Scholar con los términos: peer review, research proposals, review and protocols and reviewers. Debido a que no se identificó ningún artículo que refiriera específicamente los criterios para evaluar protocolos de investigación clínica, se hizo un consenso entre los vocales de la Comisión Nacional de Investigación Científica del Instituto Mexicano del Seguro Social, que está integrada por investigadores titulares de la institución, todos pertenecientes al Sistema Nacional de Investigadores. Se discutieron los criterios que debieran componer una revisión adecuada y cuáles debieran ser los rubros que deben incluirse en el análisis. Resultados: se integraron los criterios específicos que le permitirán al revisor de un protocolo de investigación realizar una crítica con bases metodológicas aceptadas por un consenso de investigadores. Conclusiones: un revisor debe ser considerado como un promotor del avance del conocimiento científico que, mediante sus comentarios y su dictamen, permite que los investigadores incrementen la calidad de sus protocolos de investigación.

  4. Modelo semi-empírico de protuberancia solar a partir del diagnóstico de densidades

    NASA Astrophysics Data System (ADS)

    Cirigliano, D.; Vial, J. C.; Rovira, M.

    A partir de la observación del espectro del quintuplete de C III alrededor de 1175 Å, se ha realizado el diagnóstico de la densidad y presión electrónica, basado en el cálculo del cociente de las intensidades observadas. Una vez establecida la densidad electrónica, y con el cálculo de las velocidades Doppler, hemos investigado el flujo de masa en la protuberancia en función de la temperatura. Estableciendo como hipótesis la conservación del número de partículas que ingresan y salen del cuerpo de la protuberancia, se investiga la variación del área de un tubo de flujo semi-empírico en función de la temperatura. A partir de dicho diagnóstico, se examina el comportamiento del radio del tubo magnético en función de la temperatura, los que dan cuenta de la abertura de las líneas de campo magnético que confinan el plasma y de la divergencia del campo magnético en diferentes alturas de la atmósfera solar.

  5. High mountain soils and periglacial features at the Torres del Paine, National Park Torres del Paine, Chile.

    NASA Astrophysics Data System (ADS)

    Senra, Eduardo; Schaefer, Carlos; Simas, Felipe; Gjorup, Davi

    2015-04-01

    The Torres del Paine National Park (TPNP) is located on the southern limit of the Andean Southern Ice Field, part of the Magallanes and Antartica Chilena region, in the province of Ultima Esperanza. The TPNP has a very heterogeneous climate due to orographic influence and wet air masses from the Pacific. The geology is basically Cretaceous metasedimentary rocks and Miocene granitic plutons and batholiths. We studied the main soils and geoenvironments of Mt Ferrier mountain and its surroundings, based on soils , landforms and vegetation aspects. The geoenvironmental stratification was based on the combined variation and integration of pedo-litho-geomorphological features with the vegetation. WE used detailed geological maps, a DEM and slope maps and WorlView II satellite images. Fifteen soils profiles were sampled and classified according to Soil Taxonomy (2010) at all genovironments, ranging from 50 m a.s.l to the at high plateau just below the permanent snowline, under periglacial conditions (~1004m asl). Three soil temperature and moisture monitoring sites were set, allowing for 24 consecutive months (2011 to 2013). Seven geoenvironments were identified with distinct soil and landform characteristics, all with a similar geological substrate. The landform and vegetation have a strong connection with the landscape dynamic, controlling erosional and depositional processes, resulting from glacier advances and retreats in the Late Quaternary. Wind blown materials is widespread, in the form of loess material, accumulating in the higher parts of the landscape. On the other hand, accumulation of organic matter in the water-saturated depressions is common in all altitudes. Generally the soils are acidic and dystrophic, with little exceptions. The following geoenvironments were identified: Periglacial Tundra, Loess slopes, Talus and scarpmentd, Fluvio-glacial terraces, Fluvio-lacustrine plains, Moraines and Paleodunes. The regional pedology show the occurrence of five soil

  6. Using Del-1 to Tip the Angiogenic Balance in Endothelial Cells in Modular Constructs

    PubMed Central

    Ciucurel, Ema C.; Vlahos, Alexander E.

    2014-01-01

    Modular tissue engineering is a method of building vascularized tissue-engineered constructs. Submillimeter-sized collagen pieces (modules) coated with a layer of endothelial cells (EC; vascular component), and with embedded functional cells, are self-assembled into a larger, three-dimensional tissue. In this study, we examined the use of developmental endothelial locus-1 (Del-1), an extracellular matrix protein with proangiogenic properties, as a means of tipping the angiogenic balance in human umbilical vein endothelial cells incorporated in modular tissue-engineered constructs. The motivation was to enhance the vascularization of these constructs upon transplantation in vivo, in this case, without the use of exogenous mesenchymal stromal cells. EC were transduced using a lentiviral construct to overexpress Del-1. The Del-1 EC formed more sprouts in a fibrin gel sprouting assay in vitro compared with eGFP (control) transduced EC, as expected. Del-1 EC had a distinct profile of gene expression (upregulation of matrix metalloproteinase-9 [MMP-9], urokinase-type plasminogen activator [uPA/PLAU], vascular endothelial growth factor [VEGF-A], and intercellular adhesion molecule-1 [ICAM-1]; downregulation of angiopoietin-2 [Ang2]), also supporting the notion of “tipping the angiogenic balance”. On the other hand, contrary to our expectations, when Del-1 EC-coated modules were implanted subcutaneously in a severe combined immunodeficient/beige animal model, the proangiogenic effect of Del-1 was less remarkable. There was only a small increase in the number of blood vessels formed in Del-1 implants compared with the eGFP implants, and only few blood vessels formed at the implant site in both cases. This was presumed due to limited EC survival after transplantation. We speculate that if we could improve EC survival in our study (for example, by adding other prosurvival factors or supporting cells), we would see a greater Del-1-induced angiogenic benefit in vivo as a

  7. La implantacion del enfoque constructivista en el aula de ciencia: Estudio de caso multiple

    NASA Astrophysics Data System (ADS)

    Arroyo Betancourt, Luz I.

    Esta investigacion estudia la implantacion del enfoque constructivista en tres aulas de ciencia del contexto puertorriqueno. Se auscultaron las practicas educativas que utilizan maestras consideradas constructivistas y la correspondencia de sus practicas educativas con los elementos esenciales de la didactica que proponen los teoricos de los planteamientos constructivistas. Se ausculto, ademas, a que vision del enfoque constructivista responden las expresiones de las maestras acerca de su practica educativa y como compara con su quehacer, a la luz de los elementos esenciales de las visiones constructivistas piagetiana, social y radical. Se utilizo el diseno de estudio descriptivo de caso multiple. El estudio se baso en entrevistas a profundidad, revision de documentos y observacion no participativa a la sala de clases. El contexto fueron tres escuelas publicas de la Region Educativa de San Juan, una elemental, una intermedia y una superior. Los resultados confirmaron que la transicion hacia el enfoque constructivista es un proceso que toma tiempo, dedicacion y la participacion en adiestramientos y readiestramientos acerca del nuevo enfoque. Las maestras coinciden en la mayoria de las practicas educativas que utilizan para implantar el enfoque constructivista de ensenanza y difieren en algunas debido, probablemente, a que han tenido que adaptarlas a los correspondientes niveles de ensenanza: elemental, intermedio y superior. Dos de las maestras planifican por conceptos generadores, mientras que una de ellas planifica siguiendo la guia que recibe del Departamento de Educacion. Difieren ademas, en el enfasis que confieren al inquirir cientifico. Con relacion a la correspondencia entre la vision manifestada por las maestras a la luz de las visiones piagetiana, social y radical, aparentemente, las preguntas del protocolo de entrevistas no lograron evocar la informacion con suficiente profundidad, por lo que la investigadora tuvo que inferir las visiones de las

  8. Detecting a hierarchical genetic population structure via Multi-InDel markers on the X chromosome

    PubMed Central

    Fan, Guang Yao; Ye, Yi; Hou, Yi Ping

    2016-01-01

    Detecting population structure and estimating individual biogeographical ancestry are very important in population genetics studies, biomedical research and forensics. Single-nucleotide polymorphism (SNP) has long been considered to be a primary ancestry-informative marker (AIM), but it is constrained by complex and time-consuming genotyping protocols. Following up on our previous study, we propose that a multi-insertion-deletion polymorphism (Multi-InDel) with multiple haplotypes can be useful in ancestry inference and hierarchical genetic population structures. A validation study for the X chromosome Multi-InDel marker (X-Multi-InDel) as a novel AIM was conducted. Genetic polymorphisms and genetic distances among three Chinese populations and 14 worldwide populations obtained from the 1000 Genomes database were analyzed. A Bayesian clustering method (STRUCTURE) was used to discern the continental origins of Europe, East Asia, and Africa. A minimal panel of ten X-Multi-InDels was verified to be sufficient to distinguish human ancestries from three major continental regions with nearly the same efficiency of the earlier panel with 21 insertion-deletion AIMs. Along with the development of more X-Multi-InDels, an approach using this novel marker has the potential for broad applicability as a cost-effective tool toward more accurate determinations of individual biogeographical ancestry and population stratification. PMID:27535707

  9. The RGD finger of Del-1 is a unique structural feature critical for integrin binding

    SciTech Connect

    Schürpf, Thomas; Chen, Qiang; Liu, Jin-huan; Wang, Rui; Springer, Timothy A.; Wang, Jia-huai

    2012-11-13

    Developmental endothelial cell locus-1 (Del-1) glycoprotein is secreted by endothelial cells and a subset of macrophages. Del-1 plays a regulatory role in vascular remodeling and functions in innate immunity through interaction with integrin {alpha}{sub V}{beta}{sub 3}. Del-1 contains 3 epidermal growth factor (EGF)-like repeats and 2 discoidin-like domains. An Arg-Gly-Asp (RGD) motif in the second EGF domain (EGF2) mediates adhesion by endothelial cells and phagocytes. We report the crystal structure of its 3 EGF domains. The RGD motif of EGF2 forms a type II' {beta} turn at the tip of a long protruding loop, dubbed the RGD finger. Whereas EGF2 and EGF3 constitute a rigid rod via an interdomain calcium ion binding site, the long linker between EGF1 and EGF2 lends considerable flexibility to EGF1. Two unique O-linked glycans and 1 N-linked glycan locate to the opposite side of EGF2 from the RGD motif. These structural features favor integrin binding of the RGD finger. Mutagenesis data confirm the importance of having the RGD motif at the tip of the RGD finger. A database search for EGF domain sequences shows that this RGD finger is likely an evolutionary insertion and unique to the EGF domain of Del-1 and its homologue milk fat globule-EGF 8. The RGD finger of Del-1 is a unique structural feature critical for integrin binding.

  10. VEGF: a modifier of the del22q11 (DiGeorge) syndrome?

    PubMed

    Stalmans, Ingeborg; Lambrechts, Diether; De Smet, Frederik; Jansen, Sandra; Wang, Jian; Maity, Sunit; Kneer, Paige; von der Ohe, Maren; Swillen, Ann; Maes, Christa; Gewillig, Marc; Molin, Daniel G M; Hellings, Peter; Boetel, Thurid; Haardt, Maartin; Compernolle, Veerle; Dewerchin, Mieke; Plaisance, Stephane; Vlietinck, Robert; Emanuel, Beverly; Gittenberger-de Groot, Adriana C; Scambler, Peter; Morrow, Bernice; Driscol, Deborah A; Moons, Lieve; Esguerra, Camila V; Carmeliet, Geert; Behn-Krappa, Annett; Devriendt, Koen; Collen, Désiré; Conway, Simon J; Carmeliet, Peter

    2003-02-01

    Hemizygous deletion of chromosome 22q11 (del22q11) causes thymic, parathyroid, craniofacial and life-threatening cardiovascular birth defects in 1 in 4,000 infants. The del22q11 syndrome is likely caused by haploinsufficiency of TBX1, but its variable expressivity indicates the involvement of additional modifiers. Here, we report that absence of the Vegf164 isoform caused birth defects in mice, reminiscent of those found in del22q11 patients. The close correlation of birth and vascular defects indicated that vascular dysgenesis may pathogenetically contribute to the birth defects. Vegf interacted with Tbx1, as Tbx1 expression was reduced in Vegf164-deficient embryos and knocked-down vegf levels enhanced the pharyngeal arch artery defects induced by tbx1 knockdown in zebrafish. Moreover, initial evidence suggested that a VEGF promoter haplotype was associated with an increased risk for cardiovascular birth defects in del22q11 individuals. These genetic data in mouse, fish and human indicate that VEGF is a modifier of cardiovascular birth defects in the del22q11 syndrome.

  11. Multiplex pyrosequencing of InDel markers for forensic DNA analysis.

    PubMed

    Bus, Magdalena M; Karas, Ognjen; Allen, Marie

    2016-12-01

    The capillary electrophoresis (CE) technology is commonly used for fragment length separation of markers in forensic DNA analysis. In this study, pyrosequencing technology was used as an alternative and rapid tool for the analysis of biallelic InDel (insertion/deletion) markers for individual identification. The DNA typing is based on a subset of the InDel markers that are included in the Investigator(®) DIPplex Kit, which are sequenced in a multiplex pyrosequencing analysis. To facilitate the analysis of degraded DNA, the polymerase chain reaction (PCR) fragments were kept short in the primer design. Samples from individuals of Swedish origin were genotyped using the pyrosequencing strategy and analysis of the Investigator(®) DIPplex markers with CE. A comparison between the pyrosequencing and CE data revealed concordant results demonstrating a robust and correct genotyping by pyrosequencing. Using optimal marker combination and a directed dispensation strategy, five markers could be multiplexed and analyzed simultaneously. In this proof-of-principle study, we demonstrate that multiplex InDel pyrosequencing analysis is possible. However, further studies on degraded samples, lower DNA quantities, and mixtures will be required to fully optimize InDel analysis by pyrosequencing for forensic applications. Overall, although CE analysis is implemented in most forensic laboratories, multiplex InDel pyrosequencing offers a cost-effective alternative for some applications.

  12. BRCA1 4153delA founder mutation in Russian ovarian cancer patients.

    PubMed

    Krylova, Nadezhda Yu; Lobeiko, Oksana S; Sokolenko, Anna P; Iyevleva, Aglaya G; Rozanov, Maxim E; Mitiushkina, Natalia V; Gergova, Madina M; Porhanova, Tatiana V; Urmancheyeva, Adel F; Maximov, Sergey Ya; Togo, Alexandr V; Imyanitov, Evgeny N

    2006-09-15

    The BRCA1 4153delA allele is frequently referred to as the Russian founder mutation, as it was initially detected in several cancer families from Moscow. Our earlier studies have demonstrated 1% occurrence of BRCA1 4153delA heterozygosity in familial and/or early-onset and/or bilateral Russian breast cancer (BC) patients. Since literature data suggest that the 4153delA variant is more associated with ovarian cancer (OC) than with BC, we expected to reveal a highly elevated frequency of this genotype in Russian ovarian cancer series. However, real-time allele-specific PCR genotyping has detected only two BRCA1 4153delA carriers out of 177 unselected OC patients (1.1%). Both these carriers were early-onset and had serous carcinomas of grade 3. Thus, our study supports neither the Russian origin of BRCA1 4153delA mutation, nor its selectivity towards ovarian versus breast cancer predisposition.

  13. Del1 Knockout Mice Developed More Severe Osteoarthritis Associated with Increased Susceptibility of Chondrocytes to Apoptosis

    PubMed Central

    Wang, Zhen; Tran, Misha C.; Bhatia, Namrata J.; Hsing, Alexander W.; Chen, Carol; LaRussa, Marie F.; Fattakhov, Ernst; Rashidi, Vania; Jang, Kyu Yun; Choo, Kevin J.; Nie, Xingju; Mathy, Jonathan A.; Longaker, Michael T.; Dauskardt, Reinhold H.; Helms, Jill A.; Yang, George P.

    2016-01-01

    Objective We identified significant expression of the matricellular protein, DEL1, in hypertrophic and mature cartilage during development. We hypothesized that this tissue-specific expression indicated a biological role for DEL1 in cartilage biology. Methods Del1 KO and WT mice had cartilage thickness evaluated by histomorphometry. Additional mice underwent medial meniscectomy to induce osteoarthritis, and were assayed at 1 week for apoptosis by TUNEL staining and at 8 weeks for histology and OA scoring. In vitro proliferation and apoptosis assays were performed on primary chondrocytes. Results Deletion of the Del1 gene led to decreased amounts of cartilage in the ears and knee joints in mice with otherwise normal skeletal morphology. Destabilization of the knee led to more severe OA compared to controls. In vitro, DEL1 blocked apoptosis in chondrocytes. Conclusion Osteoarthritis is among the most prevalent diseases worldwide and increasing in incidence as our population ages. Initiation begins with an injury resulting in the release of inflammatory mediators. Excessive production of inflammatory mediators results in apoptosis of chondrocytes. Because of the limited ability of chondrocytes to regenerate, articular cartilage deteriorates leading to the clinical symptoms including severe pain and decreased mobility. No treatments effectively block the progression of OA. We propose that direct modulation of chondrocyte apoptosis is a key variable in the etiology of OA, and therapies aimed at preventing this important step represent a new class of regenerative medicine targets. PMID:27505251

  14. Ectopsocidae (Psocodea: 'Psocoptera') from Valle del Cauca and NNP Gorgona, Colombia.

    PubMed

    Manchola, Oscar Fernando Saenz; Obando, Ranulfo González; Aldrete, Alfonso N García

    2014-04-14

    The results of a survey of the psocid family Ectopsocidae in Valle del Cauca and NNP Gorgona, are here presented. Fifteen species were identified, in the genera Ectopsocus (14 species), and Ectopsocopsis (one species); four of the Ectopsocus species are new to science and are here described and illustrated. The male of E. thorntoni García Aldrete is here described. Records of Ectopsocopsis cryptomeriae (Enderlein), Ectopsocus briggsi McLachlan, E. californicus Banks, E. columbianus Badonnel, E. maindroni Badonnel, E. meridionalis Ribaga, E. pilosus Badonnel, E. richardsi Pearman, E. titschacki Jentsch, and E. vilhenai Badonnel, are provided. Ten species were found only in Valle del Cauca, two species were found only in the NNP Gorgona, and three species were found at both sites. The specimens studied are deposited in the Entomological Museum, Universidad del Valle, Santiago de Cali, Colombia (MUSENUV).

  15. Biotic association and palaeoenvironmental reconstruction of the "Loma del Pterodaustro" fossil site (Early Cretaceous, Argentina)

    USGS Publications Warehouse

    Chiappe, L.; Rivarola, D.; Cione, A.; Fregenal-Martinez, M.; Sozzi, H.; Buatois, L.; Gallego, O.; Laza, J.; Romero, E.; Lopez-Arbarello, A.; Buscalioni, A.; Marsicano, C.; Adamonis, S.; Ortega, F.; McGehee, S.; Di, Iorio O.

    1998-01-01

    A sedimentological analysis of the basal section of the Early Cretaceous, lacustrine Lagarcito Formation at "Loma del Pterodaustro" (San Luis, Argentina) and a summary of its biological components are presented. Three sedimentological facies can be recognized in the basal sequence of the Lagarcito Formation. Fossil remains are particularly abundant in laminated claystones of a facies interpreted as deposits formed in offshore areas of the lake. The preservation of delicate structures allows recognition of these deposits as a Konservat Lagersta??tte. Up to now, rocks at "Loma del Pterodaustro" have yielded plants, conchostracans, semionotid and pleuropholid fishes, pterodactyloid pterosaurs, and a variety of invertebrate traces. The chronology of the Lagarcito Formation is discussed and it is concluded that this unit is of Albian age. The palaeoenvironment of deposition of the basal sequence of the Lagarcito Formation at "Loma del Pterodaustro" is interpreted as a perennial, shallow lake developed within an alluvial plain, under semiarid climatic conditions.

  16. L'eliosismologia: onde sismiche per studiare l'interno del Sole

    NASA Astrophysics Data System (ADS)

    Di Mauro, M. P.

    2014-12-01

    Negli ultimi cinquanta anni siamo stati testimoni di una straordinaria rivoluzione della conoscenza e comprensione della nostra stella grazie alla nascita dell'Eliosismologia, lo studio delle oscillazioni solari. Analogamente a ciò che accade nella Terra durante i terremoti, anche l'interno del Sole è pervaso continuamente da onde sismiche che provocano piccole oscillazioni, ovvero deformazioni della fotosfera. Le oscillazioni sono la manifestazione di diversi processi che avvengono all'interno della struttura del Sole e le frequenze sismiche dei modi osservati e misurati sulla superficie sono legate direttamente ai parametri fisici degli strati interni attraversati dalle onde sismiche. Lo studio delle oscillazioni rappresenta, quindi, l'unico metodo diretto per studiare la struttura e la dinamica interna del Sole. In questo articolo verranno illustrate le caratteristiche generali delle oscillazioni solari e verranno presentati i risultati importanti e i progressi notevoli raggiunti grazie all'Eliosismologia.

  17. Trichomycetes living in the guts of aquatic insects of Misiones and Tierra del Fuego, Argentina.

    PubMed

    López Lastra, Claudia C; Scorsetti, Ana C; Marti, Gerardo A; Coscarón, Sixto

    2005-01-01

    Fourteen species of Trichomycetes living in the guts of aquatic insects are reported from two provinces of Argentina, Misiones and Tierra del Fuego. Twelve of the species belong to the Harpellales and two are Amoebidiales. Five harpellid species are reported from Misiones in the extreme northeast of the country (Genistellospora homothallica, Harpella tica, Smittium culisetae, Smittium sp., Stachylina sp.) and seven are from Tierra del Fuego, the southern tip of South America (H. meridianalis, Glotzia sp., S. culicis, S. cellaspora, S. imitatum, Stachylina minima, Penella simulii). Insect hosts all were immature stages of Culicidae, Simuliidae, Chironomidae, Ceratopogonidae (Insecta: Diptera), and Ephemeroptera and Plecoptera. The lower diversity of Trichomycetes found at Misiones, which has a subtropical climate and rainforest vegetation, was due possibly to the warmer temperatures of the water (15-24 C), compared to the colder streams of Tierra del Fuego (9-15 C), with forests and steppes as typical vegetation.

  18. Mejoras en el apuntado del telescopio de 2,15 mts de CASLEO

    NASA Astrophysics Data System (ADS)

    Aballay, J. L.; Casagrande, A. R.; Pereyra, P. F.; Marún, A. H.

    Con el objeto de optimizar el funcionamiento del telescopio de 2,15 mts. de CASLEO, se están eliminando los motores de calar, de guía y mecánica asociada. Para ésto, se están diseñando dos electrónicas que gobernarán, solamente, el motor de slew y el de tracking. Con el control del motor de slew se realizarán las funciones de slew y calar, controlando desde una PC la placa que maneja las rampas de velocidad. De este modo, el movimiento será programado y por lo tanto, más suave y preciso. Con el control del motor de tracking, a través de un generador de frecuencias programable desde una PC, se proveerá los movimientos necesarios para el tracking y guía.

  19. Development and Utilization of InDel Markers to Identify Peanut (Arachis hypogaea) Disease Resistance

    PubMed Central

    Liu, Lifeng; Dang, Phat M.; Chen, Charles Y.

    2015-01-01

    Peanut diseases, such as leaf spot and spotted wilt caused by Tomato Spotted Wilt Virus, can significantly reduce yield and quality. Application of marker assisted plant breeding requires the development and validation of different types of DNA molecular markers. Nearly 10,000 SSR-based molecular markers have been identified by various research groups around the world, but less than 14.5% showed polymorphism in peanut and only 6.4% have been mapped. Low levels of polymorphism limit the application of marker assisted selection (MAS) in peanut breeding programs. Insertion/deletion (InDel) markers have been reported to be more polymorphic than SSRs in some crops. The goals of this study were to identify novel InDel markers and to evaluate the potential use in peanut breeding. Forty-eight InDel markers were developed from conserved sequences of functional genes and tested in a diverse panel of 118 accessions covering six botanical types of cultivated peanut, of which 104 were from the U.S. mini-core. Results showed that 16 InDel markers were polymorphic with polymorphic information content (PIC) among InDels ranged from 0.017 to 0.660. With respect to botanical types, PICs varied from 0.176 for fastigiata var., 0.181 for hypogaea var., 0.306 for vulgaris var., 0.534 for aequatoriana var., 0.556 for peruviana var., to 0.660 for hirsuta var., implying that aequatoriana var., peruviana var., and hirsuta var. have higher genetic diversity than the other types and provide a basis for gene functional studies. Single marker analysis was conducted to associate specific marker to disease resistant traits. Five InDels from functional genes were identified to be significantly correlated to tomato spotted wilt virus (TSWV) infection and leaf spot, and these novel markers will be utilized to identify disease resistant genotype in breeding populations. PMID:26617627

  20. Epidemiological surveillance of ovine hydatidosis in Tierra del Fuego, Patagonia Argentina, 1997-1999.

    PubMed

    Zanini, Fabián; Gonzalo, Roberto; Pérez, Héctor; Aparici, Inés; Soto, Ximena; Guerrero, Juvenal; Cerrone, Gloria; Elissondo, Celina

    2006-06-15

    Cystic echinococcosis is the most prevalent zoonosis in Tierra del Fuego province, Argentina, with important economic, productive and public health consequences. The present work was performed to determine the ovine prevalence in Tierra del Fuego, Argentina, as well as to evaluate the quality of diagnostic systems in slaughterhouses. Moreover, genetic analyses to characterize the strain of Echinococcus granulosus involved in the region were done. The first actions to perform a diagnosis of the epidemiological situation of hydatidosis in Tierra del Fuego were done between 1976 and 1977. A canine prevalence of 80% and an ovine prevalence of 55% results were obtained. Since 1979 the control program of Hydatidosis of Tierra del Fuego was implemented. It was based on semiannual canine anthelmintic treatment with praziquantel at dose of 5mg/kg, and complemented with sanitary education and canine and ovine epidemiological surveillance. During May 1997-January 1999: 5,916 sheep coming from 20 farms of the programmatic area were evaluated. In the lamb category, hydatid cysts were not found. In the adults category, 62 infected animals were found (3.2%). The ovine prevalence was 1.1% and there was 100% of coincidence between diagnosis in the slaughterhouse, re-inspection in the laboratory and histopathological study. The marked decrease in the prevalence observed for sheep infection evidenced a destabilization of the biological cycle of the parasite. This could be explained by the application of a control program with uninterrupted systematic actions. Polymerase chain reaction-ribosomal ITS-1 DNA (rDNA) restriction fragment length polymorphism (PCR-RFLP) analysis and partial sequencing of the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene were used to characterize E. granulosus isolates collected from different regions of Tierra del Fuego to determine which genotypes occurred in this region. The results revealed the presence of the G1 genotype (sheep-dog strain

  1. An unexpected effect of TNF-α on F508del-CFTR maturation and function.

    PubMed

    Bitam, Sara; Pranke, Iwona; Hollenhorst, Monika; Servel, Nathalie; Moquereau, Christelle; Tondelier, Danielle; Hatton, Aurélie; Urbach, Valérie; Sermet-Gaudelus, Isabelle; Hinzpeter, Alexandre; Edelman, Aleksander

    2015-01-01

    Cystic fibrosis (CF) is a multifactorial disease caused by mutations in the cystic fibrosis transmembrane conductance regulator gene ( CFTR), which encodes a cAMP-dependent Cl (-) channel. The most frequent mutation, F508del, leads to the synthesis of a prematurely degraded, otherwise partially functional protein. CFTR is expressed in many epithelia, with major consequences in the airways of patients with CF, characterized by both fluid transport abnormalities and persistent inflammatory responses. The relationship between the acute phase of inflammation and the expression of wild type (WT) CFTR or F508del-CFTR is poorly understood. The aim of the present study was to investigate this effect. The results show that 10 min exposure to TNF-alpha (0.5-50ng/ml) of F508del-CFTR-transfected HeLa cells and human bronchial cells expressing F508del-CFTR in primary culture (HBE) leads to the maturation of F508del-CFTR and induces CFTR chloride currents. The enhanced CFTR expression and function upon TNFα is sustained, in HBE cells, for at least 24 h. The underlying mechanism of action involves a protein kinase C (PKC) signaling pathway, and occurs through insertion of vesicles containing F508del-CFTR to the plasma membrane, with TNFα behaving as a corrector molecule. In conclusion, a novel and unexpected action of TNFα has been discovered and points to the importance of systematic studies on the roles of inflammatory mediators in the maturation of abnormally folded proteins in general and in the context of CF in particular.

  2. Haplotype analysis of the 185delAG BRCA1 mutation in ethnically diverse populations

    PubMed Central

    Laitman, Yael; Feng, Bing-Jian; Zamir, Itay M; Weitzel, Jeffrey N; Duncan, Paul; Port, Danielle; Thirthagiri, Eswary; Teo, Soo-Hwang; Evans, Gareth; Latif, Ayse; Newman, William G; Gershoni-Baruch, Ruth; Zidan, Jamal; Shimon-Paluch, Shani; Goldgar, David; Friedman, Eitan

    2013-01-01

    The 185delAG* BRCA1 mutation is encountered primarily in Jewish Ashkenazi and Iraqi individuals, and sporadically in non-Jews. Previous studies estimated that this is a founder mutation in Jewish mutation carriers that arose before the dispersion of Jews in the Diaspora ∼2500 years ago. The aim of this study was to assess the haplotype in ethnically diverse 185delAG* BRCA1 mutation carriers, and to estimate the age at which the mutation arose. Ethnically diverse Jewish and non-Jewish 185delAG*BRCA1 mutation carriers and their relatives were genotyped using 15 microsatellite markers and three SNPs spanning 12.5 MB, encompassing the BRCA1 gene locus. Estimation of mutation age was based on a subset of 11 markers spanning a region of ∼5 MB, using a previously developed algorithm applying the maximum likelihood method. Overall, 188 participants (154 carriers and 34 noncarriers) from 115 families were included: Ashkenazi, Iraq, Kuchin-Indians, Syria, Turkey, Iran, Tunisia, Bulgaria, non-Jewish English, non-Jewish Malaysian, and Hispanics. Haplotype analysis indicated that the 185delAG mutation arose 750–1500 years ago. In Ashkenazim, it is a founder mutation that arose 61 generations ago, and with a small group of founder mutations was introduced into the Hispanic population (conversos) ∼650 years ago, and into the Iraqi–Jewish community ∼450 years ago. The 185delAG mutation in the non-Jewish populations in Malaysia and the UK arose at least twice independently. We conclude that the 185delAG* BRCA1 mutation resides on a common haplotype among Ashkenazi Jews, and arose about 61 generations ago and arose independently at least twice in non-Jews. PMID:22763381

  3. The novel complex allele [A238V;F508del] of the CFTR gene: clinical phenotype and possible implications for cystic fibrosis etiological therapies.

    PubMed

    Diana, Anna; Polizzi, Angela Maria; Santostasi, Teresa; Ratclif, Luigi; Pantaleo, Maria Giuseppina; Leonetti, Giuseppina; Iusco, Danila Rosa; Gallo, Crescenzio; Conese, Massimo; Manca, Antonio

    2016-06-01

    Few mutations in cis have been annotated for F508del homozygous patients. Southern Italy patients who at a first analysis appeared homozygous for the F508del mutation (n=63) or compound heterozygous for the F508del and another mutation in the cystic fibrosis transmembrane conductance regulator gene (n=155) were searched for the A238V mutation in exon 6. The allelic frequency of the complex allele [A238V;F508del] was 0.04. When the whole data set was used (comprised also of 56 F508del/F508del and 34 F508del/other mutation controls), no differences reached the statistical significance in the clinical parameters, except chloride concentrations which were lower in [A238V;F508del]/other mutation compared with F508del/other mutation (P=0.03). The two study groups presented less complications than the control groups. Within the minimal data set (34 F508del/F508del, 27 F508del/other mutation, 4 [A238V;F508del]/F508del cases and 5 [A238V;F508del]/other mutation cases); that is, presenting all the variables in each patient, forced expiratory volume in 1 s and forced vital capacity presented a trend to lower levels in the study groups in comparison with the F508del/F508del group, and C-reactive protein approximated statistically significant higher levels in the [A238V;F508del]/other mutation as compared with F508del/F508del patients (P=0.09). The analysis of statistical dependence among the variables showed a significant anticorrelation between chloride and body mass index in the [A238V;F508del]/other mutation group. In conclusion, the complex allele [A238V;F508del] seems to be associated with less general complications than in the control groups, on the other hand possibly giving a worse pulmonary phenotype and higher systemic/local inflammatory response. These findings have implications for the correct recruitment and clinical response of F508del patients in the clinical trials testing the new etiological drugs for cystic fibrosis.

  4. Gonadal dysgenesis, Turner syndrome with 46,XX,del(18p)3

    SciTech Connect

    Telvi, L.; Ion, R.; Bernheim, A.

    1994-09-01

    The authors report a case of a female infant with gonadal dysgenesis, clinical features of Turner syndrome and a de novo del(18p). The factors controlling gonadal dysgenesis and Turner syndrome are unknown to date. The genes involved could be located not only on X chromosome but also on autosomes. The present case suggests that one of these genes is situated on the short arm of chromosome 18. We conclude that patients with del(18p) syndrome should be evaluated for gonadal dysgenesis.

  5. Black hole remnant and quantum tunnelling in three-dimensional Gödel spacetime

    NASA Astrophysics Data System (ADS)

    Li, Hui-Ling; Zu, Xiao-Tao

    2015-05-01

    Using the modified Dirac equation in a three-dimensional gravity background, we investigate the quantum correction to tunnelling radiation from a Gödel black hole, and discuss the black hole remnant employing fermion's tunnelling. The corrected tunnelling probability is derived, and the modified Hawking temperature is found as well. It is worth emphasizing that, only when the condition j> αω(3 r -- r +) is satisfied, emitting both a mass particle and a massless particle, the remnant of the Gödel black hole may arise.

  6. An InDel-based linkage map of hot pepper (Capsicum annuum).

    PubMed

    Li, Weipeng; Cheng, Jiaowen; Wu, Zhiming; Qin, Cheng; Tan, Shu; Tang, Xin; Cui, Junjie; Zhang, Li; Hu, Kailin

    Two independent pepper (Capsicum annuum) genomes were published recently, opening a new era of molecular genetics research on pepper. However, pepper molecular marker technologies are still mainly focusing on the simple sequence repeats derived from public database or genomic library. The development and application of the third generation marker system such as single nucleotide polymorphisms, structure variations as well as insertion/deletion polymorphisms (InDels) is still in its infancy. In the present study, we developed InDel markers for pepper genetic mapping with the convenience of two whole-genome re-sequenced inbred lines BA3 (C. annuum) and B702 (C. annuum). A total of 154,519 and 149,755 InDel (1-5 bp) sites were identified for BA3 and B702, respectively, by the alignment of re-sequencing reads to Zunla-1 reference genome. Then, 14,498 InDel sites (only 4 and 5 bp) that are different between BA3 and B702 were predicted. Finally, within a random set of 1,000 primer pairs, 251 InDel markers were validated and mapped onto a linkage map using F2 population derived from the intraspecific cross BA3 × B702. The first InDel-based map, named as BB-InDel map, consisted of 12 linkage groups, covered a genetic distance of 1,178.01 cM and the average distance between bin markers was 5.01 cM. Compared to the Zunla-1 reference physical map, high consistency was observed on all 12 chromosomes, and the total length of scaffold anchored and physical distance covered by this map was 299.66 and 2,558.68 Mb, respectively, which accounted for 8.95 and 76.38 % of the Zunla-1 reference genome (3.35 Gb), respectively. Furthermore, 37 scaffolds (total length of 36.21 Mb) from the pseudo-chromosome (P0) of the current genome assembly were newly assigned to the corresponding chromosomes by 40 InDel markers. Thus, this map provided good genome coverage and would be useful for basic and applied research in pepper.

  7. A new fish, Peristedion nesium (Scorpaeniformes: Peristediidae) from Isla del Coco, Costa Rica.

    PubMed

    Bussing, William A

    2010-12-01

    Several expeditions in recent years to Isla del Coco have increased the total number of species of fishes known from the island. Several of these species have been described as new endemics (Bussing 1983, 1990, 1991a, 1991b, 1997). During the 1972 R/V Searcher Expedition to Costa Rica several trawl collections were made around Isla del Coco. At five localities in depths between 110 and 180m, 86 specimens of a new species of Peristedion were taken and are described herein. A key to the four species of Eastern Pacific Peristedion is included.

  8. Refractory primary immune thrombocytopenia with subsequent del(5q) MDS: complete remission of both after lenalidomide.

    PubMed

    Mortensen, Thomas Bech; Frederiksen, Henrik; Marcher, Claus Werenberg; Preiss, Birgitte

    2017-01-04

    A patient with refractory primary immune thrombocytopenia (ITP) characterised by severe skin and mucosal bleedings was treated with several ITP-directed therapies including cyclophosphamide. He later developed therapy-related del(5q) myelodysplastic syndrome with no dysplastic morphological features in bone marrow. He remained severely thrombocytopenic, which suggests ongoing immune mediated platelet destruction. After two 3 week cycles of low-dose lenalidomide, complete cytogenetic remission and complete normalisation of platelet count were observed. This suggests that lenalidomide may be a viable treatment option for ITP in the presence of del(5q) not responding to standard treatments.

  9. Ecos del Cosmos: A radio astroexperience at the Universitat de Valencia

    NASA Astrophysics Data System (ADS)

    Marco, E.; Ballesteros, F. J.; Ortiz-Gil, A.

    2017-03-01

    During the last three years Ecos del Cosmos has been a radio program dedicated to spreading astronomical hot news to the Universitat de València community and beyond, and also topics of general astronomical interest. To do this, this program by Ràdio Universitat has conducted live interviews with researchers, explored relationships of astronomy with humanities and society, performed contests and explained in a simple way the main monthly ephemerides. A version of Ecos del Cosmos was broadcasted in the Onda Cero’s summer program ''Jelo en verano''conducted by Arturo Tellez.

  10. Archivo de placas astrométricas del Observatorio de La Plata

    NASA Astrophysics Data System (ADS)

    di Sisto, R.; Orellana, R. B.

    Se ha realizado una base de datos con las placas fotográficas obtenidas con el Astrográfico del Observatorio de La Plata. Se han clasificado un total de 3000 placas obtenidas para asteroides y cometas. El acceso a la base de datos se hará por FTP y la misma contendrá la siguiente información: fecha y tiempo de exposición, coordenadas del centro de placa, tipo de emulsión fotográfica, estado de la placa, objeto fotografiado.

  11. A review on Balanites aegyptiaca Del (desert date): phytochemical constituents, traditional uses, and pharmacological activity

    PubMed Central

    Chothani, Daya L.; Vaghasiya, H. U.

    2011-01-01

    Balanites aegyptiaca Del. (Zygophyllaceae), known as ‘desert date,’ is spiny shrub or tree up to l0 m tall, widely distributed in dry land areas of Africa and South Asia. It is traditionally used in treatment of various ailments i.e. jaundice, intestinal worm infection, wounds, malaria, syphilis, epilepsy, dysentery, constipation, diarrhea, hemorrhoid, stomach aches, asthma, and fever. It contains protein, lipid, carbohydrate, alkaloid, saponin, flavonoid, and organic acid. Present review summarizes the traditional claims, phytochemistry, and pharmacology of B. aegyptiaca Del reported in scientific literature. PMID:22096319

  12. Do crustal deformations observed by GPS in Tierra del Fuego (Argentina) reflect glacial-isostatic adjustment?

    NASA Astrophysics Data System (ADS)

    Mendoza, L.; Richter, A.; Hormaechea, J. L.; Perdomo, R.; Del Cogliano, D.; Dietrich, R.; Fritsche, M.

    2010-09-01

    Vertical site velocities determined by geodetic GPS observations in the Lago Fagnano area, Tierra del Fuego main island, are interpreted with respect to their potential relation with the glacial-isostatic crustal response to ice mass changes. The spatial pattern of the uplift rates, in combination with the horizontal crustal deformation pattern, point towards a fault-tectonic rather than glacial-isostatic origin of the determined vertical crustal deformations. This implies rather small GIA effects pointing towards relatively small Holocene ice-mass changes in Tierra del Fuego. However, these findings are considered to be preliminary. They should be confirmed by additional observations covering an extended area with GPS sites.

  13. Development of EST-based SNP and InDel markers and their utilization in tetraploid cotton genetic mapping

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Expressed sequence tags (ESTs) were analyzed in silico in order to identify single nucleotide polymorphisms (SNPs) and insertion-deletion polymorphisms (InDels) in cotton. A total of 1349 EST-based SNP and InDel markers were developed by comparing ESTs between Gossypium hirsutum and G. barbadense, m...

  14. 75 FR 39668 - Notice of Availability of Final Environmental Impact Statement for the Proposed Rio del Oro...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-12

    ... (FEIS) for the Rio del Oro Specific Plan Project, a proposed master-planned, mixed use development... a mixed- use development in the approximately 3,828-acre Rio del Oro Specific Plan Area. In response... (City). The City is the local agency responsible for preparing an Environmental Impact Report...

  15. DELIVERING TIMELY AIR QUALITY, TRAFFIC, AND WEATHER INFORMATION TO YOUR COMMUNITY/THE PASO DEL NORTE ENVIRONMENTAL MONITORING PROJECT

    EPA Science Inventory

    EPA has developed a technology transfer handbook for the EMPACT Paso del Norte Project. The EMPACT Paso del Norte Environmental Monitoring Project is a mobile vehicle emissions project that involves the international community of El Paso, TX; Sundland Park, NM; and Juarez, Mexico...

  16. Del(15q) is a recurrent “minor route” cytogenetic abnormality in the clonal evolution of chronic myelogenous leukemia

    PubMed Central

    Yin, C. Cameron; Abruzzo, Lynne V.; Qiu, Xiaoyan; Apostolidou, Effrosyni; Cortes, Jorge E.; Medeiros, L. Jeffrey; Lu, Gary

    2014-01-01

    Del(15q) is known to occur in acute leukemias, but has been described rarely in chronic myelogenous leukemia (CML). We describe five cases of CML associated with del(15q). There were four men and one woman. Bone marrow aspirate smears demonstrated increased blasts in all cases at the time of del(15q) detection, showing accelerated phase in two and myeloid blast phase in three. Conventional cytogenetic analysis showed t(9;22) and del(15q), as well as other inconsistent clonal abnormalities. All patients received imatinib mesylate, four received additional chemotherapy, and two underwent allogeneic stem cell transplantation (ASCT). For the three patients who did not receive ASCT, one died, one was in persistent blast phase, and one was in clinical remission with molecular evidence of residual disease, 16, 6, and 34 months after identification of del(15q), respectively. For the two patients who underwent ASCT, one died and one was in clinical remission with molecular evidence of disease, 15 and 64 months after identification of del(15q), respectively. Our findings indicate that del(15q) is a recurrent cytogenetic abnormality that may be seen either at initial presentation of advanced disease or emerge during disease progression. Del(15q) appears to be associated with a poor prognosis in CML. PMID:19480932

  17. Identification and functional characterisation of a novel KCNJ2 mutation, Val302del, causing Andersen-Tawil syndrome.

    PubMed

    Ördög, Balázs; Hategan, Lidia; Kovács, Mária; Seprényi, György; Kohajda, Zsófia; Nagy, István; Hegedűs, Zoltán; Környei, László; Jost, Norbert; Katona, Márta; Szekeres, Miklós; Forster, Tamás; Papp, Julius Gy; Varró, András; Sepp, Róbert

    2015-07-01

    Loss-of-function mutations of the KCNJ2 gene encoding for the inward rectifier potassium channel subunit Kir2.1 cause Andersen-Tawil Syndrome (ATS), a rare genetic disorder characterised by periodic paralysis, ventricular arrhythmias, and dysmorphic features. Clinical manifestations of the disease appear to vary greatly with the nature of mutation, therefore, functional characterisation of ATS-causing mutations is of clinical importance. In this study, we describe the identification and functional analysis of a novel KCNJ2 mutation, Val302del, identified in a patient with ATS. Heterologously expressed wild type (WT) and Val302del mutant alleles showed similar subcellular distribution of the Kir2.1 protein with high intensity labelling from the membrane region, demonstrating normal membrane trafficking of the Val302del Kir2.1 variant. Cells transfected with the WT allele displayed a robust current with strong inward rectification, while no current above background was detected in cells expressing the Val302del Kir2.1 subunit. Co-transfection of CHO cells with the WT and the Val302del Kir2.1 revealed a dose-dependent inhibitory effect of the Val302del Kir2.1 mutant subunit on WT Kir2.1 currents. These observations indicate that the WT and the Val302del mutant subunits co-assemble in the cell membrane and that the mutation affects potassium conductivity and (or) gating of the WT/Val302del heteromeric Kir2.1 channels.

  18. 75 FR 44720 - Safety Zone; Live-Fire Gun Exercise, M/V Del Monte, James River, VA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Live-Fire Gun Exercise, M/V Del Monte... specified waters of the James River to protect mariners from the hazards associated with live fire and... conduct a live fire and explosive training event onboard the M/V Del Monte in the vicinity of the...

  19. Calumenin contributes to ER-Ca(2+) homeostasis in bronchial epithelial cells expressing WT and F508del mutated CFTR and to F508del-CFTR retention.

    PubMed

    Philippe, Réginald; Antigny, Fabrice; Buscaglia, Paul; Norez, Caroline; Huguet, Florentin; Castelbou, Cyril; Trouvé, Pascal; Becq, Frédéric; Frieden, Maud; Férec, Claude; Mignen, Olivier

    2017-02-04

    Cystic Fibrosis (CF) is the most frequent fatal genetic disease in Caucasian populations. Mutations in the chloride channel CF Transmembrane Conductance Regulator (CFTR) gene are responsible for functional defects of the protein and multiple associated dysregulations. The most common mutation in patients with CF, F508del-CFTR, causes defective CFTR protein folding. Thus minimal levels of the receptor are expressed at the cell surface as the mutated CFTR is retained in the endoplasmic reticulum (ER) where it correlates with defective calcium (Ca(2+)) homeostasis. In this study, we discovered that the Ca(2+) binding protein Calumenin (CALU) is a key regulator in the maintenance of ER-Ca(2+) calcium homeostasis in both wild type and F508del-CFTR expressing cells. Calumenin modulates SERCA pump activity without drastically affecting ER-Ca(2+) concentration. In addition, reducing Calumenin expression in CF cells results in a partial restoration of CFTR activity, highlighting a potential function of Calumenin in CFTR maturation. These findings demonstrate a pivotal role for Calumenin in CF cells, providing insights into how modulation of Calumenin expression or activity may be used as a potential therapeutic tool to correct defects in F508del-CFTR.

  20. Causal Transformation of GÖDEL-TYPE Spacetimes in Conformal Field Theory

    NASA Astrophysics Data System (ADS)

    Gusin, Pawel

    The Gödel-type metrics are considered as backgrounds of the sigma-models. In the conformal field theory such backgrounds are deformed by the exactly marginal operators. We examine, how the closed timelike curves (CTCs) transform under such deformations.

  1. Exploración del Sistema Solar -- Una mirada hacia el futuro

    NASA Video Gallery

    ¿Piensas que ya sabemos todo acerca de nuestro sistema solar? La realidad es que apenas hemos comenzado con lo que hay para conocer. Únete a la NASA, en el envío de misiones a los confines del sist...

  2. Dolores Del Rio, the First "Latin Invasion", and Hollywood's Transition to Sound

    ERIC Educational Resources Information Center

    Beltran, Mary

    2005-01-01

    The career and promotion of Mexican actress Dolores Del Rio as a case study of how Hollywood's shift to sound film affected Latino and Latina actors is examined. It reveals the way in which the starring opportunities for Latinos dwindled when accent and language increasingly marked them as nonwhite in the 1930s in the talkie films.

  3. Acantholachesilla gen. n. (Psocodea:'Psocoptera': Lachesillidae: Eolachesillinae: Graphocaeciliini) from Valle del Cauca, Colombia.

    PubMed

    Aldrete, Alfonso N García; Manchola, Oscar Fernando Saenz; Obando, Ranulfo González

    2014-06-25

    Acantholachesilla saltoensis gen. et sp. n. is described from Valle del Cauca, Colombia, in the Lachesillidae, tribe Graphocaeciliini (Eolachesillinae). The genus is related to Dagualachesilla and Dagualachesilloides that occur in the same area, differing from them in the male clunial projection, phallosome, and female subgenital plate and gonapophyses.

  4. A tectonically controlled basin-fill within the Valle del Cauca, West-Central Colombia

    SciTech Connect

    Rine, J.M.; Keith, J.F. Jr.; Alfonso, C.A.; Ballesteros, I.; Laverde, F.; Sacks, P.E.; Secor, D.T. Jr. ); Perez, V.E.; Bernal, I.; Cordoba, F.; Numpaque, L.E. )

    1993-02-01

    Tertiary strata of the Valle del Cauca reflect a forearc/foreland basin tectonic history spanning a period from pre-uplift of the Cordillera Central to initiation of uplift of the Cordillera Occidental. Stratigraphy of the Valle del Cauca begins with Jurassic-Cretaceous rocks of exotic and/or volcanic provenance and of oceanic origin. Unconformably overlying these are Eocene to Oligocene basal quartz-rich sandstones, shallow marine algal limestones, and fine-grained fluvial/deltaic mudstones and sandstones with coalbeds. These Eocene to Oligocene deposits represent a period of low tectonic activity. During late Oligocene to early Miocene, increased tectonic activity produced conglomeratic sediments which were transported from east to west, apparently derived from uplift of the Cordillera Central, and deposited within a fluvial to deltaic setting. East-west shortening of the Valle del Cauca basin folded the Eocene to early Miocene units, and additional uplift of the Cordillera Central during the later Miocene resulted in syn-tectonic deposition of alluvial fans. After additional fold and thrust deformation of the total Eocene-Miocene basin-fill, tectonic activity abated and Pliocene-Quaternary alluvial and lacustrine strata were deposited. Within the framework of this depositional and tectonic history of the Valle del Cauca, hydrocarbon exploration strategies can be formulated and evaluated.

  5. Climatic controls on debris-flow activity and sediment aggradation: The Del Medio fan, NW Argentina

    NASA Astrophysics Data System (ADS)

    Savi, Sara; Schildgen, Taylor F.; Tofelde, Stefanie; Wittmann, Hella; Scherler, Dirk; Mey, Jürgen; Alonso, Ricardo N.; Strecker, Manfred R.

    2016-12-01

    In the Central Andes, several studies on alluvial terraces and valley fills have linked sediment aggradation to periods of enhanced sediment supply. However, debate continues over whether tectonic or climatic factors are most important in triggering the enhanced supply. The Del Medio catchment in the Humahuaca Basin (Eastern Cordillera, NW Argentina) is located within a transition zone between subhumid and arid climates and hosts the only active debris-flow fan within this intermontane valley. By combining 10Be analyses of boulder and sediment samples within the Del Medio catchment, with regional morphometric measurements of nearby catchments, we identify the surface processes responsible for aggradation in the Del Medio fan and their likely triggers. We find that the fan surface has been shaped by debris flows and channel avulsions during the last 400 years. Among potential tectonic, climatic, and autogenic factors that might influence deposition, our analyses point to a combination of several favorable factors that drive aggradation. These are in particular the impact of occasional abundant rainfall on steep slopes in rock types prone to failure, located in a region characterized by relatively low rainfall amounts and limited transport capacity. These characteristics are primarily associated with the climatic transition zone between the humid foreland and the arid orogen interior, which creates an imbalance between sediment supply and sediment transfer. The conditions and processes that drive aggradation in the Del Medio catchment today may provide a modern analog for the conditions and processes that drove aggradation in other nearby tributaries in the past.

  6. Community Arts Programs: Cohesion and Difference Case Studies. Henry Street Settlement and El Museo del Barrio

    ERIC Educational Resources Information Center

    Kiebert-Gruen, Cathleen

    2009-01-01

    A comparative case study of two cultural institutions, Henry Street Settlement and El Museo del Barrio, founded almost eighty years apart, were involved in social justice causes and community arts. Although both of these institutions participated in the political activism of their time, they also demonstrated an important adaptability. They were…

  7. Shed Some Light on the Subject: Teaching Ramon del Valle-Inclan's "Luces de bohemia"

    ERIC Educational Resources Information Center

    Parker, Jason Thomas

    2011-01-01

    This essay seeks to provide parallel and interchangeable approaches to teaching Ramon del Valle-Inclan's challenging play "Luces de bohemia". A greater understanding of the cultural and mental frameworks of the early twentieth-century Spanish spectator will permit students to penetrate the dense intertextuality that characterizes Valle's…

  8. CHEK2 ∗1100delC Mutation and Risk of Prostate Cancer

    PubMed Central

    Park, Jong Y.

    2014-01-01

    Although the causes of prostate cancer are largely unknown, previous studies support the role of genetic factors in the development of prostate cancer. CHEK2 plays a critical role in DNA replication by responding to double-stranded breaks. In this review, we provide an overview of the current knowledge of the role of a genetic variant, 1100delC, of CHEK2 on prostate cancer risk and discuss the implication for potential translation of this knowledge into clinical practice. Currently, twelve articles that discussed CHEK2∗1100delC and its association with prostate cancer were identified. Of the twelve prostate cancer studies, five studies had independent data to draw conclusive evidence from. The pooled results of OR and 95% CI were 1.98 (1.23–3.18) for unselected cases and 3.39 (1.78–6.47) for familial cases, indicating that CHEK2∗1100delC mutation is associated with increased risk of prostate cancer. Screening for CHEK2∗1100delC should be considered in men with a familial history of prostate cancer. PMID:25431674

  9. Urban Impact of Dissolved Metals in the Paso del Norte Segment of the Rio Grande

    ERIC Educational Resources Information Center

    Freiwan, Sumayeh Ahmad

    2013-01-01

    The Paso del Norte segment of the Rio Grande experiences two seasons per year; the (wet) irrigation season and the (dry) non-irrigation season. The goal of this study was to improve the understanding of occurrence and contribution of dissolved metals in this region during the non-irrigation season. The objectives of this study were to (1) evaluate…

  10. A Failed Utopia in Marcela Del Río's "Proceso a Faubritten"

    ERIC Educational Resources Information Center

    Manickam, Samuel

    2014-01-01

    In Marcela del Río's science fiction novel "Proceso a Faubritten," utopia comes in the form of eternal life for all of humanity, thanks to Dr. Alexander Faubritten's "Bomba L." This polyphonic work includes diaries by Faubritten and his Mexican lover, María Corona. In my analysis of these two diaries, I will show how…

  11. Functional Rescue of F508del-CFTR Using Small Molecule Correctors

    PubMed Central

    Molinski, Steven; Eckford, Paul D. W.; Pasyk, Stan; Ahmadi, Saumel; Chin, Stephanie; Bear, Christine E.

    2012-01-01

    High-throughput screens for small molecules that are effective in “correcting” the functional expression of F508del-CFTR have yielded several promising hits. Two such compounds are currently in clinical trial. Despite this success, it is clear that further advances will be required in order to restore 50% or greater of wild-type CFTR function to the airways of patients harboring the F508del-CFTR protein. Progress will be enhanced by our better understanding of the molecular and cellular defects caused by the F508del mutation, present in 90% of CF patients. The goal of this chapter is to review the current understanding of defects caused by F508del in the CFTR protein and in CFTR-mediated interactions important for its biosynthesis, trafficking, channel function, and stability at the cell surface. Finally, we will discuss the gaps in our knowledge regarding the mechanism of action of existing correctors, the unmet need to discover compounds which restore proper CFTR structure and function in CF affected tissues and new strategies for therapy development. PMID:23055971

  12. Dropouts, Stopouts, Optouts at Del Mar College: Spring 1991. Report of a Joint Research Project.

    ERIC Educational Resources Information Center

    Luckie, Jo Ann I.; Bonham, L. Adrianne

    A research project investigated 2,313 persons who attended Del Mar College (Texas) during fall 1990 but did not enroll for spring 1991. Four sets of data were collected: (1) limited demographic information on the total student body; (2) demographic information drawn from school records to describe all nonreturnees; (3) demographic information…

  13. 33 CFR 162.200 - Marina del Rey, Calif.; restricted area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Marina del Rey, Calif.; restricted area. 162.200 Section 162.200 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.200...

  14. 33 CFR 162.200 - Marina del Rey, Calif.; restricted area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Marina del Rey, Calif.; restricted area. 162.200 Section 162.200 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.200...

  15. ATMOSPHERIC VOLATILE ORGANIC COMPOUND MEASUREMENTS DURING THE 1996 PASO DEL NORTE OZONE STUDY

    EPA Science Inventory

    Ambient air VOC samples were collected at surface air quality monitoring sites, near sources of interest, and aloft on the US (El Paso) and Mexican (Ciudad Juarez) side of the border during a six-week period of the 1996 Paso del Norte Ozone Study. Samples were collected at five...

  16. 33 CFR 162.35 - Channel of Christina River, Del.; navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Channel of Christina River, Del.; navigation. 162.35 Section 162.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.35 Channel...

  17. 33 CFR 162.35 - Channel of Christina River, Del.; navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Channel of Christina River, Del.; navigation. 162.35 Section 162.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.35 Channel...

  18. 33 CFR 162.35 - Channel of Christina River, Del.; navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Channel of Christina River, Del.; navigation. 162.35 Section 162.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.35 Channel...

  19. 33 CFR 162.35 - Channel of Christina River, Del.; navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Channel of Christina River, Del.; navigation. 162.35 Section 162.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.35 Channel...

  20. 33 CFR 162.35 - Channel of Christina River, Del.; navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Channel of Christina River, Del.; navigation. 162.35 Section 162.35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.35 Channel...

  1. Gastrointestinal helminths of Commerson's dolphins Cephalorhynchus commersonii from central Patagonia and Tierra del Fuego.

    PubMed

    Berón-Vera, B; Pedraza, S N; Raga, J A; Gil de Pertierra, A; Crespo, E A; Alonso, M K; Goodall RNP

    2001-12-05

    The stomachs and intestines of 9 Commerson's dolphins incidentally caught in trawl nets in central Patagonia and 23 stranded on beaches in Tierra del Fuego were surveyed for helminth parasites. A total of 267 individuals belonging to 4 species of parasites (1 nematode, 3 digeneans) were found in the dolphins from the first area: Anisakis sp. (larvae type 1 = A. simplex), Braunina cordiformis, Hadwenius sp. and Pholeter gastrophilus. In the Tierra del Fuego dolphins, 142 specimens belonging to 3 species (2 nematodes, 1 digenean, 1 cestode) were found: A. simplex, Hadwenius sp. and Strobilocephalus triangularis. Only 2 of the helminth species were shared in the 2 study areas, A. simplex and Hadwenius sp., and both were more common in central Patagonia. Among the species, A. simplex was most prevalent and abundant in both study areas. In Tierra del Fuego, adults of A. simplex appeared in only 1 host. Hadwenius sp., P. gastrophilus and S. triangularis are new host records for Commerson's dolphin. Species diversity and species richness were low in both study areas. Helminth communities were more diverse in central Patagonia (t = 1.97, df = 258, p < 0.05) and species richness was higher in central Patagonia (S = 4). No differences in diversity were observed between females and males of central Patagonia (t = 1.97, df = 139, p < 0.05) and between females of central Patagonia and Tierra del Fuego. The results may suggest some differences in habitat use, diet and sex between Commerson's dolphin populations in the 2 study areas.

  2. A realization theorem for the Gödel-Löb provability logic

    NASA Astrophysics Data System (ADS)

    Shamkanov, D. S.

    2016-09-01

    We present a new justification logic corresponding to the Gödel-Löb provability logic GL and prove the realization theorem connecting these two systems in such a way that all the realizations provided in the theorem are normal. Bibliography: 9 titles.

  3. Exploración del Nuevo Laboratorio Científico de Marte

    NASA Video Gallery

    Únase a Fernando Abilleira, un analista de trayectoria de la NASA para la Oficina de Exploración de Marte, y conozca las nuevas tecnologías que el nuevo robot Curiosity del Laboratorio Científico d...

  4. Is CFTR-delF508 Really Absent from the Apical Membrane of the Airway Epithelium?

    PubMed Central

    Borthwick, Lee A.; Botha, Phil; Verdon, Bernard; Brodlie, Malcolm J.; Gardner, Aaron; Bourn, David; Johnson, Gail E.

    2011-01-01

    Background Understanding where mutant CFTR is localised in airway epithelia is essential in guiding the best therapeutic approach to correct the dysfunction of the CFTR protein. The widely held paradigm is that CF patients harbouring the commonest mutation, CFTR-delF508, trap CFTR within the endoplasmic reticulum and target it for degradation. However there are conflicting reports concerning expression and localisation of CFTR-delF508 in lung tissue. To attempt to resolve this fundamental issue we developed a novel approach to measure CFTR-delF508 in the lower airways of patients who have undergone lung transplantation for advanced CF. By sampling CF and non-CF epithelium simultaneously from the same individual, confounding factors of different airway microenvironments which may have influenced previous observations can be overcome. Methods Epithelia sampled by bronchial brushing above (CF) and below (non-CF) the bronchial anastomosis were stained for CFTR and the localisation and level of expression assessed (n = 12). Results There was no significant difference in the proportion of tall columnar cells showing CFTR immunostaining as a discrete band at the apical membrane in cells harbouring the CFTR-delF508 mutation compared to non-CF cells (p = 0.21, n = 12). However, the amount of CFTR expressed at the apical surface was reduced by ∼50% in CF cells compared to non-CF cells (p = 0.04, n = 5). Conclusions Our novel observation challenges the prevailing paradigm that CFTR is essentially absent from the apical membrane of respiratory cells harbouring the CFTR-delF508 mutation. Moreover, it raises the possibility that the new generation of CFTR potentiators may offer a realistic therapeutic option for CF patients. PMID:21826241

  5. Determinacion de periodos fundamentales del suelo mediante vibraciones ambientales en el municipio de Humacao, Puerto Rico

    NASA Astrophysics Data System (ADS)

    Cintron Aponte, Rommel

    La tecnica de Nakamura ha sido utilizada a nivel mundial para determinar periodos fundamentales del suelo. La tecnica consiste en calcular y graficar cocientes espectrales H/V de vibraciones ambientales registradas sobre el suelo. Mediciones de vibraciones ambientales fueron tomadas en 151 lugares dentro del municipio de Humacao, localizado al este de Puerto Rico. Los datos se procesaron utilizando espectros de Fourier y espectros de potencia. La tecnica fue validada al compararla con los resultados de cocientes espectrales H/V de registros de sismos debiles y tambien con una modelacion numerica realizada con datos de un ensayo "downhole". Las graficas de los cocientes espectrales H/V fueron divididas en casos y grupos, los cuales dependen de la facilidad para identificar el periodo fundamental pico y amplitudes en frecuencias menores de 1 Hz, respectivamente. Los resultados obtenidos con ambos espectros fueron comparados y se concluye que los mismos se complementan para proveer resultados mas confiables. Se crearon mapas de periodos fundamentales, factores de amplitud, isoperiodos y clasificacion sismica de sitio. Los mapas de isoperiodos fueron realizados en las zonas mas pobladas sobre depositos de suelo. El mapa de periodos fundamentales del suelo mostro buena correlacion con la geologia local. El mapa de clasificacion sismica derivado de periodos de sitio fue comparado con el mapa de clasificacion sismica derivado de barrenos geotecnicos. El mapa de clasificacion obtenido de periodos puede sobreestimar un poco algunas clasificaciones del suelo. Sin embargo, este mapa puede proveer un estimado aproximado de la velocidad de onda de corte promedio del suelo hasta una profundidad de 100 pies (30 metros).

  6. Percepcion de los profesores universitarios acerca del concepto cultura cientifica y de sus implicaciones en el nuevo bachillerato del Recinto de Rio Piedras de la Universidad de Puerto Rico

    NASA Astrophysics Data System (ADS)

    Ramos Pastrana, Nilsa

    El Senado Academico del Recinto de Rio Piedras de la Universidad de Puerto Rico aprobo en el ano academico 2005-2006 la Certificacion 46, que contiene los lineamientos de un nuevo bachillerato. Este nuevo bachillerato introdujo cambios significativos en el curriculo tradicional. Entre ellos se encuentra la reduccion del componente de educacion general y el de Ciencias Biologicas en particular. La reduccion de creditos en el componente de Ciencias Biologicas ha obligado a reevaluar el concepto de cultura cientifica que desarrollan esos cursos. El proposito del estudio consistio en auscultar las percepciones de los profesores de las Facultades de Administracion de Empresas, Humanidades, Ciencias Sociales, Ciencias Naturales, Educacion y Estudios Generales del Recinto de Rio Piedras de la Universidad de Puerto Rico en torno al concepto de cultura cientifica, los contenidos disciplinares del curso de Ciencias Biologicas y la reduccion de creditos en el nuevo bachillerato. Las preguntas que guiaron la investigacion fueron: ¿cuales son las percepciones que tienen los profesores de las Facultades de Administracion de Empresas, Ciencias Sociales, Estudios Generales, Ciencias Naturales, Humanidades y Educacion, en torno al concepto de cultura cientifica y los contenidos disciplinares del curso de Ciencias Biologicas? ¿cuales son las percepciones que tienen los profesores de Ciencias Biologicas en torno al concepto cultura cientifica y los contenidos disciplinares del curso de Ciencias Biologicas? ¿existen diferencias significativas por facultad, genero, experiencia, rango y nombramiento en las percepciones que tienen los profesores del Recinto de Rio Piedras de la Universidad de Puerto Rico sobre los elementos que caracterizan la cultura cientifica y los contenidos biologicos que deben tener los egresados del Recinto? ¿que implicaciones curriculares tienen estos testimonios en el desarrollo del concepto de cultura cientifica en el nuevo bachillerato? Para realizar la

  7. Trimethylangelicin promotes the functional rescue of mutant F508del CFTR protein in cystic fibrosis airway cells.

    PubMed

    Favia, Maria; Mancini, Maria T; Bezzerri, Valentino; Guerra, Lorenzo; Laselva, Onofrio; Abbattiscianni, Anna C; Debellis, Lucantonio; Reshkin, Stephan J; Gambari, Roberto; Cabrini, Giulio; Casavola, Valeria

    2014-07-01

    Cystic fibrosis transmembrane conductance regulator (CFTR) carrying the F508del mutation is retained in endoplasmic reticulum and fails to traffic to the cell surface where it functions as a protein kinase A (PKA)-activated chloride channel. Pharmacological correctors that rescue the trafficking of F508del CFTR may overcome this defect; however, the rescued F508del CFTR still displays reduced chloride permeability. Therefore, a combined administration of correctors and potentiators of the gating defect is ideal. We recently found that 4,6,4'-trimethylangelicin (TMA), besides inhibiting the expression of the IL-8 gene in airway cells in which the inflammatory response was challenged with Pseudomonas aeruginosa, also potentiates the cAMP/PKA-dependent activation of wild-type CFTR or F508del CFTR that has been restored to the plasma membrane. Here, we demonstrate that long preincubation with nanomolar concentrations of TMA is able to effectively rescue both F508del CFTR-dependent chloride secretion and F508del CFTR cell surface expression in both primary or secondary airway cell monolayers homozygous for F508del mutation. The correction effect of TMA seems to be selective for CFTR and persisted for 24 h after washout. Altogether, the results suggest that TMA, besides its anti-inflammatory and potentiator activities, also displays corrector properties.

  8. Allele-specific impairment of GJB2 expression by GJB6 deletion del(GJB6-D13S1854).

    PubMed

    Rodriguez-Paris, Juan; Tamayo, Marta L; Gelvez, Nancy; Schrijver, Iris

    2011-01-01

    Mutations in the GJB2 gene, which encodes connexin 26, are a frequent cause of congenital non-syndromic sensorineural hearing loss. Two large deletions, del(GJB6-D13S1830) and del(GJB6-D13S1854), which truncate GJB6 (connexin 30), cause hearing loss in individuals homozygous, or compound heterozygous for these deletions or one such deletion and a mutation in GJB2. Recently, we have demonstrated that the del(GJB6-D13S1830) deletion contributes to hearing loss due to an allele-specific lack of GJB2 mRNA expression and not as a result of digenic inheritance, as was postulated earlier. In the current study we investigated the smaller del(GJB6-D13S1854) deletion, which disrupts the expression of GJB2 at the transcriptional level in a manner similar to the more common del(GJB6-D13S1830) deletion. Interestingly, in the presence of this deletion, GJB2 expression remains minimally but reproducibly present. The relative allele-specific expression of GJB2 was assessed by reverse-transcriptase PCR and restriction digestions in three probands who were compound heterozygous for a GJB2 mutation and del(GJB6-D13S1854). Each individual carried a different sequence variant in GJB2. All three individuals expressed the mutated GJB2 allele in trans with del(GJB6-D13S1854), but expression of the GJB2 allele in cis with the deletion was almost absent. Our study clearly corroborates the hypothesis that the del(GJB6-D13S1854), similar to the larger and more common del(GJB6-D13S1830), removes (a) putative cis-regulatory element(s) upstream of GJB6 and narrows down the region of location.

  9. Thermal unfolding studies show the disease causing F508del mutation in CFTR thermodynamically destabilizes nucleotide-binding domain 1

    PubMed Central

    Protasevich, Irina; Yang, Zhengrong; Wang, Chi; Atwell, Shane; Zhao, Xun; Emtage, Spencer; Wetmore, Diana; Hunt, John F; Brouillette, Christie G

    2010-01-01

    Misfolding and degradation of CFTR is the cause of disease in patients with the most prevalent CFTR mutation, an in-frame deletion of phenylalanine (F508del), located in the first nucleotide-binding domain of human CFTR (hNBD1). Studies of (F508del)CFTR cellular folding suggest that both intra- and inter-domain folding is impaired. (F508del)CFTR is a temperature-sensitive mutant, that is, lowering growth temperature, improves both export, and plasma membrane residence times. Yet, paradoxically, F508del does not alter the fold of isolated hNBD1 nor did it seem to perturb its unfolding transition in previous isothermal chemical denaturation studies. We therefore studied the in vitro thermal unfolding of matched hNBD1 constructs ±F508del to shed light on the defective folding mechanism and the basis for the thermal instability of (F508del)CFTR. Using primarily differential scanning calorimetry (DSC) and circular dichroism, we show for all hNBD1 pairs studied, that F508del lowers the unfolding transition temperature (Tm) by 6–7°C and that unfolding occurs via a kinetically-controlled, irreversible transition in isolated monomers. A thermal unfolding mechanism is derived from nonlinear least squares fitting of comprehensive DSC data sets. All data are consistent with a simple three-state thermal unfolding mechanism for hNBD1 ± F508del: N(±MgATP) ⇄ IT(±MgATP) → AT → (AT)n. The equilibrium unfolding to intermediate, IT, is followed by the rate-determining, irreversible formation of a partially folded, aggregation-prone, monomeric state, AT, for which aggregation to (AT)n and further unfolding occur with no detectable heat change. Fitted parameters indicate that F508del thermodynamically destabilizes the native state, N, and accelerates the formation of AT. PMID:20687133

  10. Estudio del Hidrógeno neutro en dirección al remanente de supernova W28

    NASA Astrophysics Data System (ADS)

    Dubner, G.; Velazquez, P.; Green, A.; Goss, W. M.; Reynoso, E.

    Se presenta un relevamiento del hidrógeno neutro alrededor del remanente de supernova W28 realizado con el radiotelescopio australiano de Parkes. Se analizan rasgos de emisión y absorción. Se muestra la existencia de estructuras anulares asociadas con el remanente. Se compara la distribución del hidrógeno neutro con la ubicación de máseres de OH detectados en la línea de 1720 MHz.

  11. 78 FR 6173 - Diana Del Grosso, Ray Smith, Joseph Hatch, Cheryl Hatch, Kathleen Kelley, Andrew Wilklund, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-29

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF TRANSPORTATION Surface Transportation Board Diana Del Grosso, Ray Smith, Joseph Hatch, Cheryl Hatch, Kathleen... Smith, Joseph Hatch, Cheryl Hatch, Kathleen Kelley, Andrew Wilklund, and Richard Kosiba...

  12. Medición de densidades medias de meteoritos: test del método de inmersión

    NASA Astrophysics Data System (ADS)

    Steren, G.

    Se evaluó una técnica simple para medir las densidades medias de meteoritos, basada en el Método de Arquímedes y que utiliza cuentas de vidrio de 40μ en lugar de un fluído esto presenta la ventaja de no ser intrusivo ni químicamente reactivo (D.Britt and G.Consolmagno, 1996, B.A.A.S.28,1106). El estudio, realizado en junio de este año por participantes de la VI Escuela de Verano del Observatorio del Vaticano, empleó 37 muestras de la colección del Observatorio del Vaticano, de las cuales 26 eran Condritas, 1 Pallasita y 1 Howardita; algunas de ellas ya habian sido estudiadas por otras técnicas aunque también se incluyeron muestras no estudiadas anteriormente.

  13. Ground Gravity, Magnetic and Electromagnetic Surveys on a Crater on Basalt of Bajada del Diablo Astrobleme-Strewn Field

    NASA Astrophysics Data System (ADS)

    Acevedo, R. D.; Prezzi, C.; Orgeira, M. J.; Rocca, M.; Martínez, O.; Ponce, J. F.; Corbella, H.; Rabassa, J.; González-Guillot, M.; Subías, I.

    2014-09-01

    With the aim of further investigate the circular structures from Bajada del Diablo, we carried out geophysics surveys and we conclude that the geophysical features could be satisfactorily explained assuming an extra-terrestrial projectile impact.

  14. Sanger Sequencing for BRCA1 c.68_69del, BRCA1 c.5266dup and BRCA2 c.5946del Mutation Screen on Pap Smear Cytology Samples.

    PubMed

    Lee, Sin Hang; Zhou, Shaoxia; Zhou, Tianjun; Hong, Guofan

    2016-02-08

    Three sets of polymerase chain reaction (PCR) primers were designed for heminested PCR amplification of the target DNA fragments in the human genome which include the site of BRCA1 c.68_69del, BRCA1 c.5266dup and BRCA2 c.5946del respectively, to prepare the templates for direct Sanger sequencing screen of these three founder mutations. With a robust PCR mixture, crude proteinase K digestate of the fixed cervicovaginal cells in the liquid-based Papanicolaou (Pap) cytology specimens can be used as the sample for target DNA amplification without pre-PCR DNA extraction, purification and quantitation. The post-PCR products can be used directly as the sequencing templates without further purification or quantitation. By simplifying the frontend procedures for template preparation, the cost for screening these three founder mutations can be reduced to about US $200 per test when performed in conjunction with human papillomavirus (HPV) assays now routinely ordered for cervical cancer prevention. With this projected price structure, selective patients in a high-risk population can be tested and each provided with a set of DNA sequencing electropherograms to document the absence or presence of these founder mutations in her genome to help assess inherited susceptibility to breast and ovarian cancer in this era of precision molecular personalized medicine.

  15. [The scientific progress of the "Clinica del Lavoro Luigi Devoto" as seen through the contents of the journal "La Medicina del Lavoro". ].

    PubMed

    Foà, V; Camerino, Donatella

    2003-01-01

    On occasion of the Centenary of the "Clinica del Lavoro Luigi Devoto", its researchers suggested that awareness of its historical identity and scientific development should constitute the basis for the future of the Institution. The directors of the Institute who have succeeded one to the other over the years have left a vivid report of the vast amount of work developed in several research fields and also of the original results achieved with significant impact on the scientific community and on society. Content analysis of "La Medicina del Lavoro" allowed us to shed light on strong bonds existing between manufacturing techniques, work organization and health, in the different political and social periods in which they developed. Many actions have been defined and several research subjects have been renewed (according to current demands and new methodological possibilities) between the past and the present, nevertheless many new approaches need to be taken in the fields of epidemiology, indoor air quality, ergophthalmology, muskuloskeletal disorders, environmental and molecular toxicology, and further research will be undertaken thanks to the potential of this discipline for the future. The aim of this report is also to express our thanks to all the medical and non-medical staff who have made their contribution over 100 years of engagement.

  16. PREVENCIÓN DEL VIH/SIDA EN LOS CIRCUITOS DE LEVANTE HSH: UNA ASIGNATURA PENDIENTE.

    PubMed

    Barreda, Victoria; Carballo-Dieguez, Alex; Marone, Rubén; Balán, Iván; Pando, María Ángeles; Avila, María Mercedes

    2010-12-01

    A partir de un relevamiento de tipo etnográfico, se describen lugares de encuentro de HSH en la Ciudad de Buenos Aires y sus prácticas sexuales. El reconocimiento de tales espacios, así como las características que asumen en ellos los encuentros sexuales entre los HSH, plantean obstáculos específicos en la adopción de comportamientos preventivos y, asimismo, generan nuevos desafíos para las actividades de prevención. Se plantean las dificultades y debates conceptuales que la misma categoría presenta, y sus consecuencias en el abordaje preventivo y teórico-metodológico para las ciencias sociales. Además, se proponen nuevos interrogantes acerca de los alcances y las limitaciones del modelo preventivo del VIH/Sida para HSH.

  17. A Neandertal mandible from the Cova del Gegant (Sitges, Barcelona, Spain).

    PubMed

    Daura, J; Sanz, M; Subirá, M E; Quam, R; Fullola, J M; Arsuaga, J L

    2005-07-01

    A human mandible from the site of Cova del Gegant is described here for the first time and compared with other Middle and Upper Pleistocene representatives of the genus Homo from Europe and Southwest Asia. The specimen was recovered from sediments which also yielded Mousterian stone tools and Pleistocene fauna. The preserved morphology of the mandible, particularly in the region of the mental foramen, clearly aligns it with the Neandertals, making the Cova del Gegant the only known site in Catalonia documenting diagnostic human skeletal remains in association with Middle Paleolithic stone tools. This represents an important new addition to the human fossil record from the Iberian Peninsula and joins the Bañolas mandible in documenting the course of human evolution in the northern Mediterranean region of Spain.

  18. Topological open string amplitudes on local toric del Pezzo surfaces via remodeling the B-model

    NASA Astrophysics Data System (ADS)

    Manabe, Masahide

    2009-09-01

    We study topological strings on local toric del Pezzo surfaces by a method called remodeling the B-model which was recently proposed by Bouchard, Klemm, Mariño and Pasquetti. For a large class of local toric del Pezzo surfaces we prove a functional formula of the Bergman kernel which is the basic constituent of the topological string amplitudes by the topological recursion relation of Eynard and Orantin. Because this formula is written as a functional of the period, we can obtain the topological string amplitudes at any point of the moduli space by a simple change of variables of the Picard-Fuchs equations for the period. By this formula and mirror symmetry we compute the A-model amplitudes on KF_2, and predict the open orbifold Gromov-Witten invariants of C/Z.

  19. Lumacaftor/ivacaftor combination for cystic fibrosis patients homozygous for Phe508del-CFTR.

    PubMed

    Zhang, W; Zhang, X; Zhang, Y H; Strokes, D C; Naren, A P

    2016-04-01

    Cystic fibrosis (CF) is a life-shortening inherited disease caused by the loss or dysfunction of the CF transmembrane conductance regulator (CFTR) channel activity resulting from mutations in the CFTR gene. Phe508del is the most prevalent mutation, with approximately 90% of all CF patients carrying it on at least one allele. Over the past two or three decades, significant progress has been made in understanding the pathogenesis of CF, and in the development of effective CF therapies. The approval of Orkambi® (lumacaftor/ivacaftor) marks another milestone in CF therapeutics development, which, with the advent of personalized medicine, could potentially revolutionize CF care and management. This article reviews the rationale, progress and future direction in the development of lumacaftor/ivacaftor combination to treat CF patients homozygous for the Phe508del-CFTR mutation.

  20. UBVJHKLM photometry and low-resolution spectroscopy of Nova Delphini 2013 (V339 Del)

    NASA Astrophysics Data System (ADS)

    Burlak, M. A.; Esipov, V. F.; Komissarova, G. V.; Shenavrin, V. I.; Taranova, O. G.; Tatarnikov, A. M.; Tatarnikova, A. A.

    We present UBVJHKLM photometric observations of Nova Delphini 2013 that started several hours before maximum light and lasted for 130 nights. Using the obtained data, we derived several photometric parameters of the Nova: the time of maximum light, brightness at maximum, rate of decline, t2=11 d. This places Nova Del 2013 among fast novae according to the classification introduced by Payne-Gaposchkin. We estimated the interstellar reddening E(B-V) = 0.18 using maps of Galactic extinction and the absolute brightness in maximum light via the MMRD relation that allowed us to determine the distance D≈ 2.7 kpc and height above the Galactic plane z≈ 440 pc. Low-resolution spectroscopy shows that Nova Del 2013 belongs to the Fe II spectral type of novae. The broad emission feature near 6825 Å observed during 2013 August and September may be the Raman-scattered O VI 1032 Å line.

  1. How the early voltage clamp studies of José del Castillo inform "modern" neuroscience.

    PubMed

    Zottoli, Steven J

    2012-10-01

    The description of ionic currents that flow across the membrane of the squid giant axon during an action potential sparked an interest in determining whether there were similar currents in vertebrates. The preparation of choice was the node of Ranvier in single myelinated fibers in frog. José del Castillo spent 3 years on the United States mainland from 1956 to 1959. During that time, he collaborated with Jerome Y. Lettvin and John W. Moore. I discuss how these individuals met one another and some of their scientific discoveries using the voltage clamp to study squid giant axons and frog nodes. Much of this work was conducted at the Marine Biological Laboratory in Woods Hole, MA, and I attempt to convey a sense of the unique scientific "melting pot" that existed at the Marine Biological Laboratory and the broader effect that del Castillo had on "modern" neuroscience.

  2. Fotometría CCD en el campo del cúmulo abierto Ruprecht 58

    NASA Astrophysics Data System (ADS)

    Giorgi, E. E.; Vázquez, R. A.; Seggewiss, W.; Ostrov, P.; Solivella, G. R.

    La región de Vela-Puppis contiene varios cúmulos cuyo estudio puede brindarnos información acerca de la cinemática y el estado evolutivo de la población estelar en las zonas externas del disco galáctico. A través de observaciones CCD en los filtros UBV en el campo del cúmulo abierto Ruprecht 58 (α2000= 8h 14m 41s, δ2000=-31o 57'), se han determinado por primera vez los parámetros fundamentales de este cúmulo tales como distancia, enrojecimiento y edad. Se analiza también la estructura de su secuencia principal y la presencia de gigantes y binarias.

  3. Closed Timelike Curves and Geodesics of GÖDEL-TYPE Metrics

    NASA Astrophysics Data System (ADS)

    Sarioğlu, Özgür

    2008-09-01

    It is shown that the spacetimes described by Gödel-type metrics with both flat and non-flat backgrounds and with constant uk always have CTCs or CNCs. The geodesic curves of these spacetimes are characterized by a lower dimensional Lorentz force equation for a charged point particle in the relevant Riemannian background. An explicit example is given for which timelike and null geodesics can never be closed.

  4. On exceptional collections of line bundles and mirror symmetry for toric Del-Pezzo surfaces

    NASA Astrophysics Data System (ADS)

    Jerby, Yochay

    2017-03-01

    Let X be a toric Del-Pezzo surface and let C r i t (W ) ⊂(ℂ*)n be the solution scheme of the Landau-Ginzburg system of equations. Denote by X° the polar variety of X. Our aim in this work is to describe a map L :C r i t (W ) →F u kt r o p(X°) whose image under homological mirror symmetry corresponds to a full strongly exceptional collection of line bundles.

  5. Pío del Río Hortega and the discovery of the oligodendrocytes

    PubMed Central

    Pérez-Cerdá, Fernando; Sánchez-Gómez, María Victoria; Matute, Carlos

    2015-01-01

    Pío del Río Hortega (1882–1945) discovered microglia and oligodendrocytes (OLGs), and after Ramón y Cajal, was the most prominent figure of the Spanish school of neurology. He began his scientific career with Nicolás Achúcarro from whom he learned the use of metallic impregnation techniques suitable to study non-neuronal cells. Later on, he joined Cajal’s laboratory. and Subsequently, he created his own group, where he continued to develop other innovative modifications of silver staining methods that revolutionized the study of glial cells a century ago. He was also interested in neuropathology and became a leading authority on Central Nervous System (CNS) tumors. In parallel to this clinical activity, del Río Hortega rendered the first systematic description of a major polymorphism present in a subtype of macroglial cells that he named as oligodendroglia and later OLGs. He established their ectodermal origin and suggested that they built the myelin sheath of CNS axons, just as Schwann cells did in the periphery. Notably, he also suggested the trophic role of OLGs for neuronal functionality, an idea that has been substantiated in the last few years. Del Río Hortega became internationally recognized and established an important neurohistological school with outstanding pupils from Spain and abroad, which nearly disappeared after his exile due to the Spanish civil war. Yet, the difficulty of metal impregnation methods and their variability in results, delayed for some decades the confirmation of his great insights into oligodendrocyte biology until the development of electron microscopy and immunohistochemistry. This review aims at summarizing the pioneer and essential contributions of del Río Hortega to the current knowledge of oligodendrocyte structure and function, and to provide a hint of the scientific personality of this extraordinary and insufficiently recognized man. PMID:26217196

  6. [Registry of myocardial infarction in a tertiary hospital of the Instituto Mexicano del Seguro Social].

    PubMed

    González-Pliego, José Angel; Gudiño-Amezcua, Diego Armando; Celis, Alfredo; Gutiérrez-Díaz, Gonzalo Israel

    2014-01-01

    Introducción: dado que el pronóstico de infarto del miocardio con elevación del segmento ST (IMCEST) depende de su manejo inmediato y de las medidas de prevención secundaria, el no seguir las recomendaciones actuales impide mejorar las expectativas de la población afectada por este padecimiento. El objetivo es describir el perfil clínico-epidemiológico y el proceso de atención del IMCEST en un hospital de tercer nivel. Métodos: se analiza la información clínica, la estratificación de riesgo, la terapia de revascularización y los hábitos de prescripción al egreso de los casos con IMCEST atendidos en un año. Resultados: se incluyeron 246 pacientes con edad promedio de 61 años; el 76 % fueron varones. La mayoría (37.3 %) de IMCEST ocurrió entre los 60 y los 69 años. El sedentarismo fue el factor de riesgo predominante. El 81.7 % de los casos tuvo score TIMI de riesgo bajo. El 35 % tuvo isquemia/viabilidad y en todos los cateterizados se demostraron obstrucciones coronarias. El 76 % se revascularizó con stent, principalmente farmacológico (77.5 %). Al egreso más del 90 % de los casos recibió estatina y antiplaquetarios, mientras otras drogas se prescribieron al 64-82 % de los casos. Conclusiones: el IMCEST predomina en hombres sedentarios de la séptima década. Estratificar el riesgo, buscar isquemia/viabilidad residual y revascularizar con stent farmacológico son prácticas comunes; el cumplimiento de recomendaciones basadas en la evidencia es mejor que en el pasado, pero todavía no es óptimo.

  7. Segundo Catálogo Estelar del Hemisferio Sur con Astrolabio Fotoeléctrico PAII

    NASA Astrophysics Data System (ADS)

    Manrique, W. T.; Podestá, R. C.; Alonso, E.; Actis, E. V.; Pacheco, A. M.; Bustos, G.; Lizhi, L.; Zezhi, W.; Fanmiao, Z.; Hongqi, W.; Perdomo, R.

    Recordamos que entre el Observatorio Astronómico ``Félix Aguilar'', el Observatorio Astronómico de Beijing y el Observatorio Astronómico de La Plata, se ha convenido en desarrollar un Proyecto de Investigación conjunto, para la observación sistemática de estrellas en el Hemisferio Sur, con el objeto de la elaboración de un Catálogo Estelar Global utilizando un Astrolabio Fotoeléctrico PAII del Observatorio de Beijing, que ha sido usado con éxito en la República de China. En este trabajo se presenta el Segundo Catálogo Estelar del Hemisferio Sur, derivado de las observaciones realizadas con el PAII instalado en el OAFA, durante el períiodo Febrero de 1992 a Marzo de 1997. En este lapso se han observado mas de 400000 pasajes estelares, obteniéndose las correcciones Δ α y Δ δ de 5241 estrellas del FK4, FK5, FK5 Ext., SRS, CAMC y GC. Las precisiones medias son del orden de ± 3,2 ms en ascensión recta y ±0."057 en declinación. Rango de magnitudes : 2,0 a 11,5 Rango de declinaciones : -3o a -60o Epoca Media : 1994.9 Se analizan los residuos en función de la magnitud y tipo espectral, correcciones de grupo y frecuencia de distribución Δ α y Δ δ.

  8. 174delG Mutation in Mouse MFRP Causes Photoreceptor Degeneration and RPE Atrophy

    PubMed Central

    Fogerty, Joseph

    2011-01-01

    Purpose. The authors have identified a recessive mutation causing progressive retinal degeneration, white fundus flecks, and eventual retinal pigment epithelium (RPE) atrophy. The goal of these studies was to characterize the retinal phenotype, to identify the causative locus, and to examine possible functions of the affected gene. Methods. SNP mapping, DNA sequencing, and genetic complementation were used to identify the affected locus. Histology, electroretinography, immunohistochemistry, Western blot analysis, fundus photography, electron microscopy, and in vitro phagocytosis assays were used to characterize the phenotype of the mouse. Results. Gene mapping identified a single base pair deletion in membrane-type frizzled related protein (MFRP), designated Mfrp174delG. MFRP is normally expressed in the RPE and ciliary body but was undetectable by Western blot in mutants. CTRP5, a binding partner of MFRP, was upregulated at the mRNA level and at the protein level in most patients. Assays designed to test the integrity of retinoid cycling and phagocytic pathways showed no deficits in Mfrp174delG or rd6 animals. However, the RPE of both Mfrp174delG and rd6 mice exhibited a dramatic increase in the number of apical microvilli. Furthermore, evidence of RPE atrophy was evident in Mfrp174delG mice by 21 months. Conclusions. The authors have identified a novel null mutation in mouse Mfrp. This mutation causes photoreceptor degeneration and eventual RPE atrophy, which may be related to alterations in the number of RPE microvilli. These mice will be useful to identify a function of MFRP and to study the pathogenesis of atrophic macular degeneration. PMID:21810984

  9. Juvenile rheumatoid arthritis and del(22q11) syndrome: a non-random association.

    PubMed Central

    Verloes, A; Curry, C; Jamar, M; Herens, C; O'Lague, P; Marks, J; Sarda, P; Blanchet, P

    1998-01-01

    Del(22q11) is a common microdeletion syndrome with an extremely variable phenotype. Besides classical manifestations, such as velocardiofacial (Shprintzen) or DiGeorge syndromes, del(22q11) syndrome may be associated with unusual but probably causally related anomalies that expand its phenotype and complicate its recognition. We report here three children with the deletion and a chronic, erosive polyarthritis resembling idiopathic cases of juvenile rheumatoid arthritis (JRA). Patient 1, born in 1983, initially presented with developmental delay, facial dysmorphism, velopharyngeal insufficiency, and severe gastro-oesophageal reflux requiring G tube feeding. From the age of 3 years, he developed JRA, which resulted in severe restrictive joint disease, osteopenia, and platyspondyly. Patient 2, born in 1976, had tetralogy of Fallot and peripheral pulmonary artery stenosis. She developed slowly, had mild dysmorphic facial features, an abnormal voice, and borderline intelligence. JRA was diagnosed at the age of 5 years. The disorder followed a subacute course, with relatively mild inflammatory phenomena, but an extremely severe skeletal involvement with major osteopenia, restrictive joint disease (bilateral hip replacement), and almost complete osteolysis of the carpal and tarsal bones with phalangeal synostoses, leading to major motor impairment and confinement to a wheelchair. Patient 3, born in 1990, has VSD, right embryo-toxon, bifid uvula, and facial dysmorphism. She developed JRA at the age of 1 year. She is not mentally retarded but has major speech delay secondary to congenital deafness inherited from her mother. In the three patients, a del(22q11) was shown by FISH analysis. These observations, and five other recently published cases, indicate that a JRA-like syndrome is a component of the del(22q11) spectrum. The deletion may be overlooked in those children with severe, chronic inflammatory disorder. Images PMID:9832043

  10. Deep source model for Nevado del Ruiz Volcano, Colombia, constrained by interferometric synthetic aperture radar observations

    NASA Astrophysics Data System (ADS)

    Lundgren, P.; Samsonov, S. V.; López, C. M.; Ordoñez, M.

    2015-12-01

    Nevado del Ruiz (NRV) is part of a large volcano complex in the northern Andes of Colombia with a large glacier that erupted in 1985, generating a lahar killing over 23,000 people in the city of Armero and 2,000 people in the town of Chinchina. NRV is the most active volcano in Colombia and since 2012 has generated small eruptions, with no casualties, and constant gas and ash emissions. Interferometric synthetic aperture radar (InSAR) observations from ascending and descending track RADARSAT-2 data show a large (>20 km) wide inflation pattern apparently starting in late 2011 to early 2012 and continuing to the time of this study in early 2015 at a LOS rate of over 3-4 cm/yr (Fig. 1). Volcano pressure volume models for both a point source (Mogi) and a spheroidal (Yang) source find solutions over 14 km beneath the surface, or 10 km below sea level, and centered 10 km to the SW of Nevado del Ruiz volcano. The spheroidal source has a roughly horizontal long axis oriented parallel to the Santa Isabel - Nevado del Ruiz volcanic line and perpendicular to the ambient compressive stress direction. Its solution provides a statistically significant improvement in fit compared to the point source, though consideration of spatially correlated noise sources may diminish this significance. Stress change computations do not favor one model over the other but show that propagating dikes would become trapped in sills, leading to a more complex pathway to the surface and possibly explaining the significant lateral distance between the modeled sources and Nevado del Ruiz volcano.

  11. Mach, Thirring & Lense, Gödel getting dizzy in space-time

    NASA Astrophysics Data System (ADS)

    Embacher, Franz

    2007-11-01

    Contrary to Newton's concept of inertia, general relativity predicts an influence of rotating matter on the structure of space and time. Anticipated by Ernst Mach, effects of this type have first been derived by Hans Thirring and Josef Lense. Almost ninety years later, we face their experimental verification. An even more dramatic scenario is provided by Kurt Gödel's cosmological model, in which nearby observers rotate with respect to each other and are free to travel to their own past.

  12. Violación del Principio de Equivalencia en Teorías con Dilatón de Cuerdas

    NASA Astrophysics Data System (ADS)

    Landau, S. J.; Sisterna, P. D.; Vucetich, H.

    Se estudian las violaciones al Principio de Equivalencia en Teorías con Dilatón de Cuerdas. En estos modelos, algunas de las constantes fundamentales dependen del espacio y del tiempo. Se muestra que los experimentos de caída libre no tienen aún precisión como para poner límites a los parámetros de la teoría.

  13. Estimaciones de Prevalencia del VIH por Género y Grupo de Riesgo en Tijuana, México: 2006

    PubMed Central

    Iñiguez-Stevens, Esmeralda; Brouwer, Kimberly C.; Hogg, Robert S.; Patterson, Thomas L.; Lozada, Remedios; Magis-Rodriguez, Carlos; Elder, John P.; Viani, Rolando M.; Strathdee, Steffanie A.

    2010-01-01

    OBJETIVO Estimar la prevalencia del VIH en adultos de 15-49 años de edad en Tijuana, México - en la población general y en subgrupos de riesgo en el 2006. METODOS Se obtuvieron datos demográficos del censo Mexicano del 2005, y la prevalencia del VIH se obtuvo de la literatura. Se construyó un modelo de prevalencia del VIH para la población general y de acuerdo al género. El análisis de sensibilidad consistió en estimar errores estándar del promedio-ponderado de la prevalencia del VIH y tomar derivados parciales con respecto a cada parámetro. RESULTADOS La prevalencia del VIH es 0.54%(N = 4,347) (Rango: 0.22%–0.86%, (N = 1,750–6,944)). Esto sugiere que 0.85%(Rango: 0.39%–1.31%) de los hombres y 0.22%(Rango: 0.04%–0.40%) de las mujeres podrían ser VIH-positivos. Los hombres que tienen sexo con hombres (HSH), las trabajadoras sexuales usuarias de drogas inyectables (MTS-UDI), MTS-noUDI, mujeres UDI, y los hombres UDI contribuyeron las proporciones más elevadas de personas infectadas por el VIH. CONCLUSIONES El número de adultos VIH-positivos entre subgrupos de riesgo en la población de Tijuana es considerable, marcando la necesidad de enforcar las intervenciones de prevención en sus necesidades específicas. El presente modelo estima que hasta 1 en cada 116 adultos podrían ser VIH-positivos. PMID:19685824

  14. Formación del contínuo de Lyman en atmósferas de estrellas B

    NASA Astrophysics Data System (ADS)

    Rohrmann, R. D.

    Se presentan resultados de modelos de atmósferas para estrellas tempranas que poseen una estructura cromosférica y una atmósfera extendida en expansión. Se analiza con rigurosidad el acople del campo de radiación en el continuo de Lyman y su relación con las poblaciones en equilibrio estadístico del H y He.

  15. The CHEK2 del5395 is a founder mutation without direct effects for cancer risk in the latvian population

    PubMed Central

    Kalniete, D; Nakazawa-Miklasevica, M; Irmejs, A; Vjaters, E; Gardovskis, J; Miklasevics, E

    2015-01-01

    Abstract Our objective was to determine: 1) whether the checkpoint kinase 2 (CHEK2) del5395 (g.27417113-27422508 del, NC_000022.11) is a founder mutation in the Latvian population, 2) if there is an association between CHEK2 del5395 mutation and cancer risk, and 3) and whether the CHEK2 del5395 mutation impacts cancer predisposition in Chernobyl disaster liquidators (the civil and military personnel who were called upon to deal with consequences of the 1986 nuclear disaster) as well as geriatric populations. We recruited 438 breast cancer patients, 568 colorectal cancer patients, 399 ovarian cancer patients, 419 prostate cancer patients, 526 healthy blood donors, 480 Chernobyl disaster liquidators and 444 geriatric cancer-free participants. DNA samples were isolated from blood samples and subjected to multiplex polymerase chain reaction (PCR). The truncation of del5395 was estimated by fragment size of the multiplex PCR.All groups were compared to the healthy blood donors using Fisher’s exact test. All p values were two-sided and the odds ratios (OR) calculated by two-by-two table. In cancer groups, the del5395 mutation was most frequently observed in the ovarian cancer group (1.00%, OR = 1.32). In control groups, the del5395 mutation was most frequent (0.76%) in the healthy donors, which exceeded its frequency in the Chernobyl liquidators group and the geriatric group by 0.01 and 0.08%, respectively. For all groups, the OR appeared to be >1 only in ovarian cancer patients. However, OR rates showed no statistical significance in either cancer or control groups, with the p value fluctuating within the range of 0.39-1.00. The CHEK2 gene del5395 is a founder mutation in the Latvian population, which, however, does not have a direct impact on genetic predisposition toward colorectal, breast, ovarian and prostate cancer. PMID:27785394

  16. Totipotent stem cells bearing del(20q) maintain multipotential differentiation in Shwachman Diamond syndrome.

    PubMed

    Crescenzi, Barbara; La Starza, Roberta; Sambani, Constantina; Parcharidou, Agapi; Pierini, Valentina; Nofrini, Valeria; Brandimarte, Lucia; Matteucci, Caterina; Aversa, Franco; Martelli, Massimo Fabrizio; Mecucci, Cristina

    2009-01-01

    SBDS/7q11 gene mutations underlie the congenital Shwachman Diamond syndrome (SDS), characterized by bone marrow failure and high risk of haematological malignancies. In two cases of SDS with bone marrow failure and isolated del(20q) interphase fluorescence in situ hybridization (I-FISH) found no abnormalities in FHIT/3p14.2, IKZF1/7p13, D7S486/7q31, PTEN/10q23.3, WT1/11p13, ATM/11q23, D13S25/13q14, TP53/17p13, NF1/17q11, SMAD2/18q21, RUNX1/21q22. Fluorescence immunophenotype combined with I-FISH found del(20q) in a totipotent haematopoietic stem cell (CD34(+), CD133(+)) and downstream myelocyte (CD33(+), CD14(+), CD13(+)), erythrocyte (Glycophorin A(+)) and lymphocyte lineages (CD19(+), CD20(+), CD3(+), CD7(+)). These findings and clinical follow-ups confirm the benign course of SDS with isolated del(20q).

  17. Heat flow and thermal processes in the Jornada delMuerto, New Mexico

    NASA Technical Reports Server (NTRS)

    Reiter, M.

    1985-01-01

    Most heat flow data in rifts are uncertain largely because of hydrologic disturbances in regions of extensive fracturing. Estimates of heat flow in deep petroleum tests within a large basin of the Rio Grande rift, which has suffered little syn-rift fracturing, may begin to provide clearer insight into the relationships between high heat flow and crustal thinning processes. The Jornada del Muerto is a large basin located in the Rio Grande rift of south central New Mexico. The region of interest within the Jornada del Muerto is centered about 30 km east of the town of Truth or Consequences, and is approximately 60 km north-south by 30 km east-west. High heat flows are estimated for the region. Values increase from about 90 mWm(-2) in the northern part of the study area to about 125 mWm(-2) in the southern part. These high heat flows are rather enigmatic because in the immediate vicinities of the sites there is little evidence of Cenozoic volcanism or syn-rift extensional tectonics. It is suggested that the geothermal anomaly in the southern Jornada del Muerto (approx. 125 to approx. 95 mWm(-2) results from some type of mass movement-heat transfer mechanism operating in the crust just below the elastic layer. This conclusion is consistent with the geologic and geophysical data which describe a thin crust, apparently devoid of features indicative of extensional-tectonics in the upper part of the lastic crust.

  18. Variation in mangrove forest structure and sediment characteristics in Bocas del Toro, Panama

    USGS Publications Warehouse

    Lovelock, C.E.; Feller, Ilka C.; McKee, K.L.; Thompson, R.

    2005-01-01

    Mangrove forest structure and sediment characteristics were examined in the extensive mangroves of Bocas del Toro, Republic of Panama. Forest structure was characterized to determine if spatial vegetation patterns were repeated over the Bocas del Toro landscape. Using a series of permanent plots and transects we found that the forests of Bocas del Toro were dominated by Rhizophora mangle with very few individuals of Avicennia germinans and Laguncularia racemosa. Despite this low species diversity, there was large variation in forest structure and in edaphic conditions (salinity, concentration of available phosphorus, Eh and sulphide concentration). Aboveground biomass varied 20-fold, from 6.8 Mg ha-1 in dwarf forests to 194.3 Mg ha-1 in the forests fringing the land. But variation in forest structure was predictable across the intertidal zone. There was a strong tree height gradient from seaward fringe (mean tree height 3.9 m), decreasing in stature in the interior dwarf forests (mean tree height 0.7 m), and increasing in stature in forests adjacent to the terrestrial forest (mean tree height 4.1 m). The predictable variation in forest structure emerges due to the complex interactions among edaphic and plant factors. Identifying predictable patterns in forest structure will aid in scaling up the ecosystem services provided by mangrove forests in coastal landscapes. Copyright 2005 College of Arts and Sciences.

  19. Lenalidomide induces ubiquitination and degradation of CK1α in del(5q) MDS.

    PubMed

    Krönke, Jan; Fink, Emma C; Hollenbach, Paul W; MacBeth, Kyle J; Hurst, Slater N; Udeshi, Namrata D; Chamberlain, Philip P; Mani, D R; Man, Hon Wah; Gandhi, Anita K; Svinkina, Tanya; Schneider, Rebekka K; McConkey, Marie; Järås, Marcus; Griffiths, Elizabeth; Wetzler, Meir; Bullinger, Lars; Cathers, Brian E; Carr, Steven A; Chopra, Rajesh; Ebert, Benjamin L

    2015-07-09

    Lenalidomide is a highly effective treatment for myelodysplastic syndrome (MDS) with deletion of chromosome 5q (del(5q)). Here, we demonstrate that lenalidomide induces the ubiquitination of casein kinase 1A1 (CK1α) by the E3 ubiquitin ligase CUL4-RBX1-DDB1-CRBN (known as CRL4(CRBN)), resulting in CK1α degradation. CK1α is encoded by a gene within the common deleted region for del(5q) MDS and haploinsufficient expression sensitizes cells to lenalidomide therapy, providing a mechanistic basis for the therapeutic window of lenalidomide in del(5q) MDS. We found that mouse cells are resistant to lenalidomide but that changing a single amino acid in mouse Crbn to the corresponding human residue enables lenalidomide-dependent degradation of CK1α. We further demonstrate that minor side chain modifications in thalidomide and a novel analogue, CC-122, can modulate the spectrum of substrates targeted by CRL4(CRBN). These findings have implications for the clinical activity of lenalidomide and related compounds, and demonstrate the therapeutic potential of novel modulators of E3 ubiquitin ligases.

  20. Lenalidomide for myelodysplastic syndromes with del(5q): how long should it last?

    PubMed

    Vozella, Federico; Latagliata, Roberto; Carmosino, Ida; Volpicelli, Paola; Montagna, Chiara; Romano, Angela; Roberto, Amanda; Finsinger, Paola; Mancini, Marco; Breccia, Massimo; Oliva, Esther; Oliva, Esther

    2015-03-01

    Lenalidomide induces in patients with myelodysplastic syndrome (MDS) and del(5q) erythroid and cytogenetic response rates as high as 75% and 50%, respectively. It is still unclear, however, how long lenalidomide treatment should be continued and whether or not the drug could be interrupted. To assess the feasibility of lenalidomide discontinuation, we revised a cohort of 16 low-risk MDS patients with del(5q) treated at our institute in a phase II multicentric Italian study. Among the 12 responding patients, four discontinued lenalidomide while in complete response. All four patients needed during treatment a permanent lenalidomide reduction from 10 to 5 mg/day because of haematological toxicity (three patients) or grade 3 muscular and bone pain (one patient). At lenalidomide discontinuation after 16, 20, 27 and 20 months from the start, respectively, all four patients were in complete hematologic response and three forth in complete cytogenetic response. Three patients are still in response after 36, 30 and 20 months from lenalidomide discontinuation, respectively: The remaining patient relapsed after 20 months, and she is now receiving a new course of lenalidomide. In conclusion, long-lasting remissions are achievable in MDS patients with del(5q) in complete response after lenalidomide discontinuation.

  1. Lenalidomide induces ubiquitination and degradation of CK1α in del(5q) MDS

    PubMed Central

    Hollenbach, Paul W.; MacBeth, Kyle J.; Hurst, Slater N.; Udeshi, Namrata D.; Chamberlain, Philip P.; Mani, D.R.; Man, Hon Wah; Gandhi, Anita K.; Svinkina, Tanya; Schneider, Rebekka K.; McConkey, Marie; Järås, Marcus; Griffiths, Elizabeth; Wetzler, Meir; Bullinger, Lars; Cathers, Brian E.; Carr, Steven A.; Chopra, Rajesh; Ebert, Benjamin L.

    2015-01-01

    Summary Lenalidomide is a highly effective treatment for myelodysplastic syndrome (MDS) with deletion of chromosome 5q (del(5q)). Here, we demonstrate that lenalidomide induces the ubiquitination of casein kinase 1A1 (CK1α) by the CRL4CRBN E3 ubiquitin ligase, resulting in CK1α degradation. CK1α is encoded by a gene within the common deleted region for del(5q) MDS and haploinsufficient expression sensitizes cells to lenalidomide therapy, providing a mechanistic basis for lenalidomide's therapeutic window in del(5q) MDS. We found that mouse cells are resistant to lenalidomide but that changing a single amino acid in mouse Crbn to the corresponding human residue enables lenalidomide-dependent degradation of CK1α. We further demonstrate that minor side chain modifications in thalidomide and a novel analogue, CC-122, can modulate the spectrum of substrates targeted by CRL4CRBN. These findings have implications for the clinical activity of lenalidomide and related compounds and demonstrate the therapeutic potential of novel modulators of E3 ubiquitin ligases. PMID:26131937

  2. Observaciones del disco solar y de una protuberancia quiescente en radiación ultravioleta

    NASA Astrophysics Data System (ADS)

    Cirigliano, D.; Vial, J.-C.; Rovira, M.

    Observaciones del disco solar y de una protuberancia quiescente en el rango de longitudes de onda ultravioleta fueron obtenidas con el instrumento CDS (Coronal Diagnostic Spectrograph) y SUMER (Solar Ultraviolet Measurements of emitted radiation) a bordo de la sonda SOHO. El propósito es investigar las velocidades macroscópicas de varias especies metálicas que se observan tanto en el disco solar como en el plasma de las protuberancias. Para calcular las velocidades del disco solar aplicamos una técnica mixta para modelar la distribución de estructuras en UV en el Sol quieto. Las velocidades macroscópicas en las protuberancias se calcularon a partir de los corrimientos Doppler en cada línea espectral y luego se tomaron las del disco solar como referencia. Obtuvimos valores absolutos para las velocidades macroscópicas entre 5 y 40 km/seg. También detectamos comportamientos diferentes en las velocidades de las protuberancias en el centro con respecto a los bordes.

  3. Traffic circulation study and long-range plan for Del Rio. Interim research report

    SciTech Connect

    Weissmann, A.J.; Islam, R.

    1996-03-01

    A 1992 report to Congress, pursuant to Intermodal Surface Transportation Efficiency Act (ISTEA) sections 1089 and 6015, acknowledges that Texas serves a disproportionate share of the U.S.-Mexico international trade, and, accordingly, recommends the development of federal-aid program options to improve transportation infrastructure related to international trade. In order to take advantage of this recommendation, border states must monitor their transborder traffic demand and develop traffic circulation plans for their border cities. This report presents a 25-year traffic circulation plan for the City of Del Rio, Texas. The plan includes recommendations for increasing roadway capacity, adding left-turn lanes, building new routes to relieve congestion, and adding international thoroughfares. It also includes a comprehensive analysis of a transborder traffic in Del Rio, as well as of international thoroughfares between Cuidad Acuna and Del Rio. The recommendations take into account input from TxDOT personnel, City officials, border inspectors, international bridge managers, and several Mexican officials. The recommendations and schedules discussed in this report can assist TxDOT not only in planning land transport infrastructure, but also in alleviating problems associated with additional highway capacity, pavement rehabilitation, signalization, and right-of-way.

  4. El diseño final del espectrógrafo de banco (EBASIM) para CASLEO

    NASA Astrophysics Data System (ADS)

    Simmons, J.; Levato, H.

    Utilizando el código de óptica ACCOS V se ha finalizado el diseño del espectrógrafo de banco para CASLEO. En una comunicación anterior habíamos indicado que utilizaríamos un colimador de 150 mm de diámetro con un radio de curvatura de 1540 mm. Para el espejo cámara, que tiene un diámetro de 200 mm, el radio de curvatura es de 1200 mm, ambos radios con una tolerancia no mayor a los 3 mm. En la presente, se informa sobre los detalles finales del cálculo del espectrógrafo que incluye el cómputo para 5 longitudes de onda diferentes y alrededor de 100 rayos. En todos los casos el 75 % de energía está dentro de un diámetro de 13 micrones. El diseño ha sido probado entre 3500 Å hasta 9000 Å con resultados satisfactorios.

  5. Relevamiento total del hemisferio sur celeste en la frecuencia de 1420 MHz

    NASA Astrophysics Data System (ADS)

    Bava, J. A.; Colomb, F. R.; Hurrel, E.; Larrarte, J. J.; Sanz, A. J.; Testori, J. C.; Reich, P.; Reich, W.; Wielebinski, R.

    En el presente artículo se describe el relevamiento del cielo en el Hemisferio Sur Celeste en la frecuencia de 1420 MHz para declinaciones δ<= -19o realizado con la Antena II de 30 metros de diámetro del IAR. Este relevamiento posee igual sensibilidad (3xr.m.s=50 mK) que el realizado en el Hemisferio Norte con el radiotelescopio de 25 metros de Stockert de la Universidad de Bonn, operado por el Max-Planck Institute für Radioastronomie ( Reich W., 1982, A&ASS 48, 219; Reich P. and Reich W., 1986, A&ASS 63, 205). Con los datos obtenidos por ambos radiotelescopios se posee una base de datos de todo el cielo en esta frecuencia. En esta publicación presentamos los detalles del sistema receptor, técnicas de observación y reducción de datos, calibración y discusión de los errores en los resultados.

  6. A Precambrian cratonic block in the west-central Chihuahua - The Sierra del Nido cratonic block

    SciTech Connect

    Goodell, P.C. . Dept. of Geological)

    1993-02-01

    Precambrian rocks in west-central Chihuahua have been recognized by Denison (1969) and Mauger et al. (1983), on the basis of radiometric dating. The rocks are rhyolite clasts, and an allucthonous block, respectively, however their source direction and vergence can be measured. They point back to and are on the edge of a large, uniform, negative Bouguer gravity anomaly, having values greater than 200 milligals. The isotopic geochemical character of several Tertiary felsic fields within this anomalous are has been determined, and initial strontium isotopic ratios are all greater than 0.7055. Outside the anomalous area these ratios are lower, and Basin and Range extension tectonism is more evident. It is proposed that a Precambrian cratonic block, the Sierra del Nido, is present in the crust in west-central Chihuahua. It is reasonable to propose that it was decreted from North America during a Precambrian extensional (1.1. By ) event, from somewhere along the Arizona Transition Zone-Texas Linament region. The Sierra del Nido Block is separated form the ATZ-TL by a region of disrupted craton and extended crust, the Basin and Range Province. Implications of the pressure of the Sierra del Nido Block on other regional tectonic events will be discussed.

  7. Campano-Maastrichtian foraminifera from onshore sediments in the Rio del Rey Basin, Southwest Cameroon

    NASA Astrophysics Data System (ADS)

    Njoh, Oliver Anoh; Victor, Obiosio; Christopher, Agyingi

    2013-03-01

    Campanian-Maastrichtian marine sediments outcrop in five genetically linked sedimentary basins along the West African coast in the Gulf of Guinea, from the Douala Basin in Cameroon to the Anambra Basin in Nigeria. These sediments in the more centrally located Rio del Rey Basin have been the least studied. Therefore, the geologic history of this region has merely been speculative. The Rio del Rey Basin like the adjacent Niger Delta is producing hydrocarbon from the offshore Tertiary sedimentary interval in which all studies have been focused, neglecting the onshore Cretaceous sediments. Outcrops in the basin are rare, small and highly weathered. Samples from some of these sediments have yielded a few Planktonic and dominantly benthonic foraminiferal assemblages. The long-ranging heterohelix and hedbergellids characterized the planktics while the species Afrobolivina afra which is a well known diagnostic taxon for Campanian-Maastrichtian sediments in West African basins clearly dominate the benthic assemblage. Its occurrence in association with other Upper Cretaceous forms such as Bolivina explicata, Praebulimina exiqua, Gabonita lata, Ammobaculites coprolithiformis amongst others, formed the basis on which this age was assigned to the sediments sampled from the Rio del Rey Basin. Hence, this work has undoubtedly established the much needed link in this regional geologic history and correlates these sediments with the Logbaba and Nkporo Formations in the Douala Basin in Cameroon and the southeastern Nigerian Sedimentary Basins. Thus, these units were all deposited during this same geologic period and probably controlled by the same geologic event.

  8. Digitalización de diapositivas del Sol en H α

    NASA Astrophysics Data System (ADS)

    Missio, H.; Montenegro, C.; Montenegro, R.

    El objetivo de este trabajo ha sido el de obtener imágenes digitalizadas de las diapositivas tomadas del Sol en luz de hidrógeno de la línea correspondiente a Hα, y de esta manera llegar a convertir las mismas a un archivo digital para poder ser tratadas luego por computadora y poder contabilizar con exactitud, mediante un programa adecuado para tal fin, las zonas activas del Sol en la imagen digitalizada. En principio, para llegar a esto se pensó en la utilización de medios accesibles, y como detector se utilizó un fototransistor ubicado dentro de un soporte rectangular sobre dos ejes de desplazamiento X e Y. Se han obtenido con este procedimiento imágenes de buena calidad, construídas a partir de tres datos digitalizados en cada barrido que aportan la posición X e Y y la intensidad del pixel en ese punto indicada en 255 tonos de grises.

  9. Mitochondrial DNA diversity of feral pigs from Karukinka Natural Park, Tierra del Fuego Island, Chile.

    PubMed

    Aravena, P; Skewes, O; Gouin, N

    2015-04-28

    Control or eradication of exotic species is one of the greatest challenges facing biodiversity and ecosystem conservation. Domestic pigs (Sus scrofa domestica) were released and became feral in the southern region of Chilean Tierra del Fuego Island in the 1900s. Currently, they inhabit part of Karukinka Natural Park, an area of global conservation concern. To gain insight into the control of this invasive species, we analyzed genetic variation in the mitochondrial DNA control region to determine the origin and population subdivision of feral pigs in Tierra del Fuego. Sequences from a sample of 42 feral pigs, 10 domestic pigs from local farms, and references from other countries and commercial breeds revealed 2 highly differentiated populations, 1 in the western and the other in the eastern area of the park, each harboring a different haplotype, suggesting no connectivity between populations. Comparison of these haplotypes with reference sequences from other countries and commercial breeds indicated that feral pigs from Chilean Tierra del Fuego are of European origin, very likely from 2 separate introduction events. The haplotype found in the western feral population was also identified in domestic pigs from a farm. This raises concerns regarding the possible connectivity between stocks from local farms and the wild population. Based on these results, we recommend the development of strategies for controlling the population of this invasive species in Karukinka Natural Park.

  10. [Seventy years of medicine in the Instituto Mexicano del Seguro Social].

    PubMed

    Fajardo-Ortiz, Guillermo

    2014-01-01

    The purpose of these lines is to remember and refer some of the historical landmarks in the evolution of the medical services of the Instituto Mexicano del Seguro Social (IMSS, according to its initials in Spanish) since it was founded, in 1943. We also want to bring to the reader's attention that the dimensions and impacts on health that IMSS has achieved, throughout its history, have strengthened the citizenship, as well as social sustainability. Also, those impacts have determined the creation and the reinforcement of human capital in México. Throughout this concise balance, all the controversy surrounding the foundation of the Institute is being recalled (the protest in the Mexico City Zócalo, or the attack to an hospital in San Ángel -a neighborhood located in the Southwest of Mexico City-), as well as the way the IMSS incorporated several words into the vocabulary of Mexicans. We also remember the previous antecedent of the Revista Médica del Instituto Mexicano del Seguro Social, as well as the Revista de Enfermería, and the emblematic Archives of Medical Research. The IMSS has 70 years of achievements, seven decades covered.

  11. TP53 suppression promotes erythropoiesis in del(5q) MDS, suggesting a targeted therapeutic strategy in lenalidomide-resistant patients.

    PubMed

    Caceres, Gisela; McGraw, Kathy; Yip, Bon Ham; Pellagatti, Andrea; Johnson, Joseph; Zhang, Ling; Liu, Kenian; Zhang, Lan Min; Fulp, William J; Lee, Ji-Hyun; Al Ali, Najla H; Basiorka, Ashley; Smith, Larry J; Daugherty, F Joseph; Littleton, Neil; Wells, Richard A; Sokol, Lubomir; Wei, Sheng; Komrokji, Rami S; Boultwood, Jacqueline; List, Alan F

    2013-10-01

    Stabilization of p53 in erythroid precursors in response to nucleosomal stress underlies the hypoplastic anemia in myelodysplastic syndromes (MDS) with chromosome 5q deletion [del(5q)]. We investigated whether cenersen, a clinically active 20-mer antisense oligonucleotide complementary to TP53 exon10, could suppress p53 expression and restore erythropoiesis in del(5q) MDS. Cenersen treatment of ribosomal protein S-14-deficient erythroblasts significantly reduced cellular p53 and p53-up-regulated modulator of apoptosis expression compared with controls, accompanied by a significant reduction in apoptosis and increased cell proliferation. In a two-stage erythroid differentiation assay, cenersen significantly suppressed nuclear p53 in bone marrow CD34+ cells isolated from patients with del(5q) MDS, whereas erythroid burst recovery increased proportionally to the magnitude of p53 suppression without evidence of del(5q) clonal suppression (r = -0.6; P = 0.005). To explore the effect of p53 suppression on erythropoiesis in vivo, dexamethasone, a glucocorticoid receptor-dependent p53 antagonist, was added to lenalidomide treatment in eight lower-risk, transfusion-dependent, del(5q) MDS patients with acquired drug resistance. Transfusion independence was restored in five patients accompanied by expansion of erythroid precursors and decreased cellular p53 expression. We conclude that targeted suppression of p53 could support effective erythropoiesis in lenalidomide-resistant del(5q) MDS.

  12. [Programme review of somatropin deficit in pediatrics at the Hospital Universitario Virgen del Rocío].

    PubMed

    Lavaredas, A; de la Puerta, R; Álvarez del Vayo, C

    2013-01-01

    Objetivo: Elaborar una revisión del programa de déficit de somatropina aplicado en pediatría en el Hospital Universitario Virgen del Rocío, utilizando dos grupos de pacientes, los diagnosticados con déficit de esta hormona y los nacidos pequeños para edad gestacional, con la intención de evaluar su efectividad en el primer año de tratamiento. Método: Realización de un estudio retrospectivo de la cohorte de pacientes en tratamiento con la hormona del crecimiento bajo los diagnósticos mencionados, con metodología observacional y transversal, a los cuales se aplicó un análisis estadístico con el programa Statistical Package for Social Sciences®. Resultados: Tras inicio del tratamiento la velocidad de crecimiento y la talla aumentaron y la edad ósea se aproximó a la edad cronológica. En los dos grupos tratados, en el primer año de tratamiento fueron los pacientes del sexo femenino con edad comprendida entre los 0 a 12 años con déficit de la hormona del crecimiento que respondieron mejor a la terapéutica establecida. Conclusiones: Pudimos observar que el tratamiento instituido se presentó altamente efectivo en ambos grupos de pacientes, permitiendo obtener un aumento favorable de estatura.

  13. Role of additional chromosomal changes in the prognostic value of t(4;14) and del(17p) in multiple myeloma: the IFM experience

    PubMed Central

    Hebraud, Benjamin; Magrangeas, Florence; Cleynen, Alice; Lauwers-Cances, Valerie; Chretien, Marie-Lorraine; Hulin, Cyrille; Leleu, Xavier; Yon, Edwige; Marit, Gerald; Karlin, Lionel; Roussel, Murielle; Stoppa, Anne-Marie; Belhadj, Karim; Voillat, Laurent; Garderet, Laurent; Macro, Margaret; Caillot, Denis; Mohty, Mohamad; Facon, Thierry; Moreau, Philippe; Attal, Michel; Munshi, Nikhil; Corre, Jill; Minvielle, Stephane

    2015-01-01

    In multiple myeloma, cytogenetic changes are important predictors of patient outcome. In this setting, the most important changes are deletion 17p, del(17p), and translocation of chromosomes 4 and 14, t(4;14), conferring a poor outcome. However, a certain degree of heterogeneity is observed in the survival of these high-risk patients. We hypothesized that other chromosomal changes may impact the outcome. We retrospectively analyzed a large series of 242 patients displaying either t(4;14) (157 patients) or del(17p) (110 patients), 25 patients presenting both abnormalities, using single nucleotide polymorphism array. In patients with t(4;14), del(1p32), del22q, and >30 chromosomal structural changes negatively impacted progression-free survival (PFS). For overall survival (OS), del(13q14), del(1p32), and the number of chromosomal structural changes worsened the prognosis of patients. For patients with del(17p), del6q worsened the prognosis of patients, whereas trisomy 15 and monosomy 14 were found to have a protective effect on PFS. For OS, del(1p32) worsened the prognosis of patients, whereas having >8 numerical changes was found to have a protective effect on survival. This study, which is the largest series of high-risk patients analyzed with the most modern genomic technique, identified 1 main factor negatively impacting survival: del(1p32). PMID:25636340

  14. Moléculas orgánicas obtenidas en simulaciones experimentales del medio interestelar.

    NASA Astrophysics Data System (ADS)

    Muñoz-Caro, Guillermo Manuel

    Las nubes moleculares son regiones de formación de estrellas, con temperaturas cinéticas entre 10-50 K y densidades de 103-106 átomos cm-3. Su materia está formada por gas y polvo interestelar. Estas partículas de polvo están cubiertas por una fina capa de hielo, de unos 0.01 μm, que contiene H2O y a menudo CO, CO2, CH3OH y NH3. El hielo es presumiblemente irradiado por fotones ultravioleta y rayos cósmicos en las zonas poco profundas de las nubes moleculares y las regiones circunestelares. En un sistema de vacío, P ˜ 10-7 mbar, simulamos la deposición de hielo a partir de 10 K y la irradiación ultravioleta por medio de una lámpara de descarga de hidrógeno activada con microondas. La evolución del hielo se observa por medio de un espectrómetro infrarrojo. De este modo es posible determinar la composición del hielo observado en el medio interestelar y predecir la presencia de moléculas aún no detectadas en el espacio, que han sido producto del procesamiento del hielo en nuestros experimentos. También es posible calentar el sistema hasta temperatura ambiente para sublimar el hielo depositado. Cuando el hielo ha sido previamente irradiado, se observa un residuo compuesto por moléculas orgánicas complejas, algunas prebióticas, como varios ácidos carboxílicos, aminas, amidas, ésteres y en menor proporción moléculas heterocíclicas y aminoácidos. Algunas de estas moléculas podrían detectarse en estado gaseoso por medio de observaciones milimétricas y de radio. También podrían estar presentes en el polvo cometario, cuyo análisis químico está planeado por las misiones Stardust y Rosetta. Mientras tanto, nuestro grupo está llevando a cabo el análisis de partículas de polvo interplanetario (IDPs), algunas de las cuales pueden ser de origen cometario. Al igual que ocurre con los productos obtenidos por irradiación del hielo en nuestros experimentos, algunas IDPs son ricas en material orgánico que contiene oxígeno.

  15. Análisis del espectro infrarrojo del polvo interestelar asociado con cúmulos globulares y de su evolución temporal

    NASA Astrophysics Data System (ADS)

    Pellizza, L. J.; Forte, J. C.; Carpintero, D.

    El trabajo que se presenta investiga la dinámica de las partículas de polvo interestelar eyectadas por estrellas gigantes rojas en un cúmulo globular utilizando simulaciones numéricas de su interacción con el campo gravitatorio y con la radiación electromagnética de las estrellas. Se pretende con ello determinar la distribución espacial de ese material como una función del tiempo en un sistema similar a NGC 104 (47 Tuc). A partir de la distribución espacial resultante se obtuvo el espectro infrarrojo integrado el cual sugiere que el máximo contraste con la radiación estelar ocurre en longitudes de onda cercanas a 300 μm y que decrece rápidamente hacia longitudes de onda menores, en las que suelen realizarse las observaciones.

  16. Systematically frameshifting by deletion of every 4th or 4th and 5th nucleotides during mitochondrial transcription: RNA self-hybridization regulates delRNA expression.

    PubMed

    Seligmann, Hervé

    2016-01-01

    In mitochondria, secondary structures punctuate post-transcriptional RNA processing. Recently described transcripts match the human mitogenome after systematic deletions of every 4th, respectively every 4th and 5th nucleotides, called delRNAs. Here I explore predicted stem-loop hairpin formation by delRNAs, and their associations with delRNA transcription and detected peptides matching their translation. Despite missing 25, respectively 40% of the nucleotides in the original sequence, del-transformed sequences form significantly more secondary structures than corresponding randomly shuffled sequences, indicating biological function, independently of, and in combination with, previously detected delRNA and thereof translated peptides. Self-hybridization decreases delRNA abundances, indicating downregulation. Systematic deletions of the human mitogenome reveal new, unsuspected coding and structural informations.

  17. Restoration of CFTR function in patients with cystic fibrosis carrying the F508del-CFTR mutation.

    PubMed

    De Stefano, Daniela; Villella, Valeria R; Esposito, Speranza; Tosco, Antonella; Sepe, Angela; De Gregorio, Fabiola; Salvadori, Laura; Grassia, Rosa; Leone, Carlo A; De Rosa, Giuseppe; Maiuri, Maria C; Pettoello-Mantovani, Massimo; Guido, Stefano; Bossi, Anna; Zolin, Anna; Venerando, Andrea; Pinna, Lorenzo A; Mehta, Anil; Bona, Gianni; Kroemer, Guido; Maiuri, Luigi; Raia, Valeria

    2014-01-01

    Restoration of BECN1/Beclin 1-dependent autophagy and depletion of SQSTM1/p62 by genetic manipulation or autophagy-stimulatory proteostasis regulators, such as cystamine, have positive effects on mouse models of human cystic fibrosis (CF). These measures rescue the functional expression of the most frequent pathogenic CFTR mutant, F508del, at the respiratory epithelial surface and reduce lung inflammation in Cftr(F508del) homozygous mice. Cysteamine, the reduced form of cystamine, is an FDA-approved drug. Here, we report that oral treatment with cysteamine greatly reduces the mortality rate and improves the phenotype of newborn mice bearing the F508del-CFTR mutation. Cysteamine was also able to increase the plasma membrane expression of the F508del-CFTR protein in nasal epithelial cells from F508del homozygous CF patients, and these effects persisted for 24 h after cysteamine withdrawal. Importantly, this cysteamine effect after washout was further sustained by the sequential administration of epigallocatechin gallate (EGCG), a green tea flavonoid, both in vivo, in mice, and in vitro, in primary epithelial cells from CF patients. In a pilot clinical trial involving 10 F508del-CFTR homozygous CF patients, the combination of cysteamine and EGCG restored BECN1, reduced SQSTM1 levels and improved CFTR function from nasal epithelial cells in vivo, correlating with a decrease of chloride concentrations in sweat, as well as with a reduction of the abundance of TNF/TNF-alpha (tumor necrosis factor) and CXCL8 (chemokine [C-X-C motif] ligand 8) transcripts in nasal brushing and TNF and CXCL8 protein levels in the sputum. Altogether, these results suggest that optimal schedules of cysteamine plus EGCG might be used for the treatment of CF caused by the F508del-CFTR mutation.

  18. Metabolomic Analysis of the Secretome of Human Embryonic Stem Cells Following Methyl Parathion and Methyl Paraoxon Exposure, Phase 1: Initial Nontargeted LC-MS

    DTIC Science & Technology

    2014-01-01

    Methylglyoxal B: Lactoyl-glutathione C: Malate (RT match to standard) D: Glycerophosphocholine ESI positive and ESI negative mode features were then...Changes in lipid homeostasis have been implicated in the pathogenesis of numerous diseases, including neurodegeneration, cancer , type 2 diabetes, and

  19. Metabolomic Analysis of the Secretome of Human Embryonic Stem Cells Following Methyl Parathion and Methyl Paraoxon Exposure Phase 2: Metabolite Downselection for Structural Confirmation

    DTIC Science & Technology

    2013-12-01

    citrate cycle or Krebs cycle Thr threonine TIC toxic industrial chemical TIM toxic industrial material Val valine ...metabolism ................................... 16  14. KEGG pathway diagram of citrate cycle (TCA cycle ...metabolism 1 Choline II Glutathione metabolism 1 Ornithine II Cys and Met metabolism 1 L-cystathionine I Citrate cycle (TCA cycle ) 1 Malic acid I

  20. Draft Genome Sequence of Burkholderia cenocepacia Strain CEIB S5-2, a Methyl Parathion- and p-Nitrophenol-Degrading Bacterium, Isolated from Agricultural Soils in Morelos, Mexico

    PubMed Central

    Martínez-Ocampo, Fernando; Fernández López, Maikel Gilberto; Lozano-Aguirre Beltrán, Luis Fernando; Popoca-Ursino, Elida Carolina; Ortiz-Hernández, M. Laura; Sánchez-Salinas, Enrique; Ramos Quintana, Fernando; Villalobos-López, Miguel A.

    2016-01-01

    Burkholderia cenocepacia is an opportunistic pathogen that belongs to Burkholderia cepacia complex (BCC). Burkholderia cenocepacia strain CEIB S5-2 was isolated from agricultural soils in Morelos, Mexico, and previously has shown its abilities for bioremediation. In this study, we report the draft genome sequence of Burkholderia cenocepacia strain CEIB S5-2. PMID:27125479