N., and Bakry, N. M. (2006)

Chem Codes: Chemical of Concern: DZ Rejection Code: IN VITRO.

The ability of the pesticides carbofuran, chlordane, diazinon, heptachlor, methoxychlor, and parathion to diminish 5[alpha]-dihydrotestosterone binding to rat ventral prostate cytoplasmic and nuclear androgen receptors was evaluated by in vitro studies. Only parathion and diazinon consistently inhibited 5[alpha]-dihydrotestosterone binding to ventral prostate cytoplasmic or nuclear androgen receptors, the remaining pesticides being relatively ineffective. The data suggested that only parathion and diazinon should be able to affect prostate homeostasis via a mechanism involving altered androgen receptor function. After 90 days of pesticide ingestion, ventral prostate androgen receptor homeostasis was altered in all the rats. Significantly, receptor homeostasis was least affected in diazinon- and parathion-fed rats, whereas ingestion of carbofuran or chlordane produced the most profound changes. Methoxychlor ingestion diminished prostate size and cell content. Carbofuran, chlordane, and parathion, but not heptachlor or diazinon, altered ventral prostate RNA metabolism without affecting cell content. Since pesticide ingestion did not alter mean plasma testosterone concentration, changes in both androgen receptor and prostate homeostasis could be attributed to pesticide action principally occurring in the ventral prostate. The absence of a correlation between pesticide inhibition of 5[alpha]-dihydrotestosterone binding to prostate androgen receptors and the pesticide's capacity to alter prostate homeostasis demonstrated inhibition studies to be ambiguous predictors of pesticide action in the ventral prostate.

Shalaby, A. A., Mostafa, A. A., and Allam, K. A. M. (2002). Field Studies on the Susceptibility of Housefly to Certain Insecticides in Nine Egyptian Governorates. J.Egypt.Soc.Parasitol. 32: 91-97.

EcoReference No.: 70112

Chemical of Concern: RSM,DZ,MLN,FNTH,DM,BRSM; Habitat: T; Effect Codes: MOR; Rejection Code: OK(ALL CHEMS),OK TARGET(DZ,RSM).

SHAMIYEH NB, PEREIRA, R., STRAW RA, FOLLUM RA, and MEISTER CW (1999). Control of wireworms in potatoes, 1998. SAXENA, K. N. (ED.). ARTHROPOD MANAGEMENT TESTS, VOL. 24. V+478P. ENTOMOLOGICAL SOCIETY OF AMERICA: LANHAM, MARYLAND, USA. ISBN 0-938522-86-8; 24 (0). 1999. 164-165.

Chem Codes: Chemical of Concern: FPN Rejection Code: METHODS.

BIOSIS COPYRIGHT: BIOL ABS. RRM BOOK CHAPTER SOLANUM TUBEROSUM MELANOTUS BEAUVERIA BASSIANA METARHIZIUM ANISOPLIAE POTATO WIREWORM CULTIVAR-YUKON GOLD HOST VEGETABLE CROP PEST CONTROL BIOLOGICAL CONTROL AGENT HORTICULTURE ECONOMIC ENTOMOLOGY PEST MANAGEMENT PESTICIDES ARTHROPOD MANAGEMENT ADMIRE INSECTICIDE EFFICACY MYCOTROL TN67-97 AGENDA FIPRONIL MOCAP DIAZINON CROSSVILLE TENNESSEE USA Vegetables/ Arachnida/ Insects/ Nematoda/ Parasites/ Plant Diseases/ Plant Diseases/ Preventive Medicine/ Herbicides/ Pest Control/ Pesticides/ Arachnida/ Entomology/Economics/ Plants/ Arachnida/ Entomology/Economics/ Pest Control, Biological/ Arachnida/ Entomology/Economics/ Pest Control/ Arachnida/ Entomology/Economics/ Insecticides/ Pest Control/ Pesticides/ Mitosporic Fungi/ Plants/ Coleoptera

Sharma, R. P. and Reddy, R. V. (1987). Toxic Effects of Chemicals on the Immune System. In: T.J.Haley and W.O.Berndt (Eds.), Handbook of Toxicology, Chapter 15, Hemisphere Publ.Corp., Washington, D.C. 555-591.
Chem Codes: EcoReference No.: 70597
Chemical of Concern: PNB,DDT,HCCH,DZ,CHD,DLD,END,HPT,TXP,PRN,CBL,AND,CTC,DBAC Rejection Code: REFS CHECKED/REVIEW.

Sharma, S. R., Singh, R. P., and Ahmed, S. R. (1985). Effect of different saline, alkaline salts, fertilizers, and surfactants on the movement of some phosphorus-containing pesticides in soils. Ecotoxicology and Environmental Safety 10: 339-350.

Chem Codes: Chemical of Concern: DZ Rejection Code: FATE.

The influence of organic matter, calcium carbonate, flyash, saline and alkaline salts, inorganic fertilizers, surfactants, and exchangeable ions on the mobility of different phosphorus pesticides has been studied using soil thin-layer chromatographic techniques. The variations in Rf, RB, and RM values of DDVP, diazinon, Ekatin, Folithion, malathion, metasystox, parathion methyl, and Rogor under different treatments is reported and explained on the basis of adsorption and leachability.

SHARMA SR, SINGH RP, and AHMED SR (1986). Effect of different salt leachates on the movement of some phosphorus containing pesticides in soils using thin-layer chromatography. ECOTOXICOL ENVIRON SAF; 11 229-240.
Chem Codes: Chemical of Concern: DZ Rejection Code: FATE.

BIOSIS COPYRIGHT: BIOL ABS. The influence of pH, leachates of alkaline and saline salts, inorganic fertilizers, and surfactants on the movement of eight organophosphorus pesticides, viz., DDVP, diazinon, Ekatin, Folithion, malathion, metasystox, parathione methyl, and Rogor has been studied using soil thin layer chromatographic techniques. The variation in the movement of pesticides under different solvent amendments are expressed in terms of Rf, RB, and RM values and are explained on the basis of adsorption and leachability.

Sharom, M. S., Miles, J. R. W., Harris, C. R., and McEwen, F. L. (1980 ). Behaviour of 12 insecticides in soil and aqueous suspensions of soil and sediment. Water Research 14: 1095-1100.
Chem Codes: Chemical of Concern: DZ Rejection Code: FATE.

The behaviour of 12 insecticides in soil and aqueous suspensions of soil and sediment was studied in the laboratory. Insecticides used were representative of the organochlorine, organophosphorus, and carbamate groups. Tests were conducted using three soils and a stream sediment. The order of adsorption on soil was DDT > leptophos > dieldrin > endrin > ethion > chlorpyrifos > lindane > parathion > diazinon > carbaryl > carbofuran > mevinphos. Organic soil had the greatest adsorptive capacity > stream sediment > Beverly sandy loam >Z Plainfield sand. Desorption and mobility of the insecticides increased with increasing solubility of the insecticides in water, even though the insecticides tested were very different in chemical structure. The results indicated that adsorption, desorption, and mobility of insecticides in soil and water will be dependent to a large extent on the nature of the adsorbents and water solubility of the insecticides.

Sharom, M. S., Miles, J. R. W., Harris, C. R., and McEwen, F. L. (1980 ). Persistence of 12 insecticides in water. Water Research 14: 1089-1093.
Chem Codes: Chemical of Concern: DZ Rejection Code: FATE.

The relative importance of chemical and biological processes in the degradation of 12 insecticides in water was studied by comparing their persistence in four types of water: natural, distilled, sterilized natural and sterilized distilled. DDT, lindane and parathion dissappeared fairly quickly in the natural water, but were very persistent in the other types indicating the importance of microbial action in their degradation. There was little indication of chemical degradation of any of the organochlorine (OC) insecticides. The four compounds most stable in water were dieldrin, endrin (OCs) ethion and leptophos [organo-phosphorus (OP) insecticides]. Generally the other OP insecticides and both carbamates disappeared from all four types of water, demonstrating that chemical processes played a major role in their degradation, with biological processes having a secondary role for chlorpyrifos, diazinon and carbaryl. The observed order of persistence after 8 weeks in natural water was dieldrin > endrin > ethion > leptophos > lindane > chlorpyrifos > diazinon > mevinphos > carbofuran > p,p′-DDT > carbaryl > parathion. The random occurrence of the chemical types in this list demonstrates that generalization on persistence in the environment cannot be made on the basis of chemical structure.

Shavnin, Sergei A., Pedroso de Lima, Maria C., Fedor, Jane, Wood, Periann, Bentz, Joe, and Duzgunes, Nejat (1988). Cholesterol affects divalent cation-induced fusion and isothermal phase transitions of phospholipid membranes. Biochimica et Biophysica Acta (BBA) - Biomembranes 946: 405-416.
Chem Codes: Chemical of Concern: DZ Rejection Code: METHODS.

The influence of cholesterol on divalent cation-induced fusion and isothermal phase transitions of large unilamellar vesicles composed of phosphatidylserine (PS) was investigated. Vesicle fusion was monitored by the terbium/dipicolinic acid assay for the intermixing of internal aqueous contents, in the temperature range 10-40[deg]C. The fusogenic activity of the cations decreases in the sequence Ca2+ > Ba2+ > Sr2+ >> Mg2+ for cholesterol concentrations in the range 20-40 mol%, and at all temperatures. Increasing the cholesterol concentration decreases the initial rate of fusion in the presence of Ca2+ and Ba2+ at 25[deg]C, reaching about 50% of the rate for pure PS at a mole fraction of 0.4. From 10 to 25[deg]C, Mg2+ is ineffective in causing fusion at all cholesterol concentrations. However, at 30[deg]C, Mg2+-induced fusion is observed with vesicles containing cholesterol. At 40[deg]C, Mg2+ induces slow fusion of pure PS vesicles, which is enhanced by the presence of cholesterol. Increasing the temperature also causes a monotonic increase in the rate of fusion induced by Ca2+, Ba2+ and Sr2+. The enhancement of the effect of cholesterol at high temperatures suggests that changes in hydrogen bonding and interbilayer hydration forces may be involved in the modulation of fusion by cholesterol. The phase behavior of PS/cholesterol membranes in the presence of Na+ and divalent cations was studied by differential scanning calorimetry. The temperature of the gel-liquid crystalline transition (Tm) in Na+ is lowered as the cholesterol content is increased, and the endotherm is broadened. Addition of divalent cations shifts the Tm upward, with a sequence of effectiveness Ba2+ > Sr2+ > Mg2+. The Tm of these complexes decreases as the cholesterol content is increased. Although the transition is not detectable for cholesterol concentrations of 40 and 50 mol% in the presence of Na+, Sr2+ or Mg2+, the addition of Ba2+ reveals endotherms with Tm progressively lower than that observed at 30 mol%. Although the presence of cholesterol appears to induce an isothermal gel-liquid crystalline transition by decreasing the Tm, this change in membrane fluidity does not enhance the rate of fusion, but rather decreases it. The effect of cholesterol on the fusion of PS/phosphatidylethanolamine (PE) vesicles was investigated by utilizing a resonance energy transfer assay for lipid mixing. The initial rate of fusion of PS/PE and PS/PE/cholesterol vesicles is saturated at high Mg2+ concentrations. With Ca2+, saturation is not observed for cholesterol-containing vesicles. The highest rate of fusion for both Ca2+- and Mg2+-induced fusion is observed with vesicles containing 30 mol% cholesterol. Membrane fusion/ Cholesterol/ Divalent cation/ Phospholipid vesicle/ Phase transition/ Phosphatidylserine/ Phosphatidylethanolamine

SHAW, A., LIN YJ, and PFEIL, E. (1997). QUALITATIVE AND QUANTITATIVE ANALYSIS OF DIAZINON IN FABRIC EXPOSED TO VARIOUS SIMULATED SUNLIGHT AND HUMIDITY CONDITIONS. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY; 59 389-395.
Chem Codes: Chemical of Concern: DZ Rejection Code: FATE.

BIOSIS COPYRIGHT: BIOL ABS. RRM RESEARCH ARTICLE DIAZINON PESTICIDES QUALITATIVE ANALYSIS QUANTITATIVE ANALYSIS SIMULATED SUNLIGHT HUMIDITY ZONYL FINISHED FABRICS PROTECTIVE CLOTHING FABRIC WEATHERING Biochemistry/ Biophysics/ Macromolecular Systems/ Molecular Biology/ Darkness/ Light/ Lighting/ Humidity/ Herbicides/ Pest Control/ Pesticides

Shaw, R. D., Cook, M., and Carson, R. E. Jr. (1968). Developments in the Resistance Status of the Southern Cattle Tick to Organophosphorus and Carbamate Insecticides. J.Econ.Entomol. 61: 1590-1594.

EcoReference No.: 72637

Chemical of Concern: PRN,DZ,CBL,HCCH,TXP,CPY; Habitat: T; Effect Codes: MOR; Rejection Code: TARGET(DZ).

Shaw, R. D., Thompson, G. E., and Baker, J. A. F. (1967). Resistance to Cholinesterase-Inhibitors in the Blue Tick, Boophilus decoloratus, in South Africa. Vet.Rec. 81: 548-549.

EcoReference No.: 72320

Chemical of Concern: CBL,DZ; Habitat: T; Effect Codes: MOR; Rejection Code: TARGET(DZ).

Shawali, Ahmad S., Farag, Ahmad M., Albar, Hassan A., and Dawood, Kamal M. (1993). Facile Syntheses of Bi-1,2,4-triazoles via hydrazonyl halides. Tetrahedron 49: 2761-2766.

Chem Codes: Chemical of Concern: DZ Rejection Code: METHODS.

Reaction of oxalodihydrazonyl dihalides 1 with sodium azide afforded the corresponding di-azides 2. Reduction of the latter with LiAlH4 yielded the diamidrazones 4 which react with acyl halides to give the bi-1,2,4-triazoles 5. The latter products were alternatively prepared by reaction of 2 with triphenylphosphine to give the phosphinimines 6 followed by treatment of the latter with acyl halides. Oxalodihydrazonyl dihalides/ oxaldiamidrazones/ oxalodihydrazonyl diazides/ bi-1,2,4-triazoles

Shellenberger, T. E., Bridgman, R. M., and Newell, G. W. (1965). inhibition of rabbit whole blood cholinesterase following intravenous infusion of a diethyl organophosphate inhibitor and reactivation with 2-PAM. Life Sciences 4: 1973-1979.
Chem Codes: Chemical of Concern: DZ Rejection Code: HUMAN HEALTH.

It is now generally accepted that the reaction of a dialkyl organophosphate with cholinesterase involves phosphorylation with the active site of the enzyme. Subsequent reactions of the phosphorylated enzyme include spontaneous reactivation and conversion, apparently first order, to a non-reversible or “aged” enzyme. The extent of these reactions is dependent on the alkyl substituents of the inhibitor and the enzyme source.Vandekar and Heath (1, 2) reported marked differences in the recovery rate of brain and erythrocyte cholinesterase activity following inhibition with “persistent” and “non-persistent” dimethyl phosphate inhibitors; enzyme recovery was more rapid after inhibition by the “non-persistent” inhibitors. However, spontaneous recovery of the enzyme, inhibited by “non-persistent” inhibitors, was markedly reduced following continuous intravenous infusion of the materials for several hours. These workers also reported that the spontaneous recovery of enzyme activity was high following short periods of compound infusion, which has been confirmed by Shellenberger (2), using three dimethyl phosphate inhibitors. When these compounds were infused intravenously into rabbits for 2 hours or less, there was rapid but incomplete recovery of inhibited whole blood cholinesterase during the immediate post-infusion period.The spontaneous reactivation of diethyl-phosphoryl cholinesterase is generally of low magnitude, even though it may occur over several days (3). The reversal of diisopropyl-phosphoryl enzyme is negligible. However, the reversal depends on both the inhibitor and the enzyme source. Species differences and differences between true and pseudo-cholinesterase reactivation have been demonstrated.In the current study, rabbit whole blood cholinesterase was rapidly and almost completely inhibited during intravenous infusion of 2, 2-dichlorovinyl diethyl phosphate. There was little, if any, spontaneous reversal of inhibited enzyme during a subsequent 3-hour postinfusion period. Intravenous injection of 2-PAM immediately and up to 2 hours after infusion produced an immediate partial recovery of enzyme activity. The extent of recovery was directly related to the dosage level of injected reactivator.

Shemer, Hilla and Linden, Karl G. ( Degradation and by-product formation of diazinon in water during UV and UV/H2O2 treatment. Journal of Hazardous Materials In Press, Corrected Proof.
Chem Codes: Chemical of Concern: DZ Rejection Code: FATE.

Kinetics and degradation products resulting from the application of UV and UV/H2O2 to the US EPA Contaminant Candidate List pesticide diazinon were studied. Batch experiments were conducted with both monochromatic (low pressure [LP] UV 253.7 nm) and polychromatic (medium pressure [MP] UV 200-300 nm) UV sources alone or in the presence of up to 50 mg l-1 H2O2, in a quasi-collimated beam apparatus. Degradation of diazinon by both UV and UV/H2O2 exhibited pseudo first order reaction kinetics, and quantum yield of 8.6 x 10-2 and 5.8 x 10-2 mol E-1 for LP and MP lamps respectively. Photolysis studies under MP UV lamp showed 2-isopropyl-6-methyl-pyrimidin-4-ol (IMP) to be the main degradation product of diazinon at aqueous solution pH values of 4, 7 and 10. Trace levels up to 1.8 x 10-3 [mu]M of diazinon oxygen analogue diethyl 2-isopropyl-6-methylpyrimidin-4-yl phosphate (diazoxon) were detected only during the UV/H2O2 reaction. Decay of both products was observed, as the UV/H2O2 reaction prolonged, yet no mineralization was achieved over the UV fluence levels examined. Photolysis kinetics, quantum yield and UV/H2O2 degradation of the reaction product IMP was determined using MP UV lamp at pH values of 4, 7 and 10. Insecticides/ Photolysis/ Advanced oxidation/ Ultraviolet irradiation

Shen, B. and Shen, Q. (1991). Pesticide Pollution. J.Environ.Sci.(China) 3: 31-48.
Chem Codes: Chemical of Concern: DDT,TCF,HCCH,DZ,ACP,MLN,DDVP,PPHD,PRN,FNT,FNTH,DEM,DMT,MTM,DS,MLT Rejection Code: REFS CHECKED/REVIEW.

Shigehisa, H. and Shiraishi, H. (1998). Biomonitoring with shrimp to detect seasonal change in river water toxicity. Environmental Toxicology and Chemistry [Environ. Toxicol. Chem.]. Vol. 17, no. 4, pp. 687-694. Apr 1998.

Chem Codes: Chemical of Concern: DZ Rejection Code: SURVEY.

ISSN: 0730-7268

Descriptors: Pollution effects
Descriptors: Pollution monitoring
Descriptors: Indicator species
Descriptors: Bioassays
Descriptors: Toxicity tests
Descriptors: Pesticides
Descriptors: Mortality
Descriptors: Agricultural runoff
Descriptors: Rice fields
Descriptors: Bioindicators
Descriptors: Toxicity
Descriptors: Seasonal Variations
Descriptors: Shrimp
Descriptors: Insecticides
Descriptors: Water Pollution Effects
Descriptors: Rivers
Descriptors: Water quality
Descriptors: Freshwater organisms
Descriptors: Paratya compressa improvisa
Descriptors: Japan
Abstract: Seasonal changes in toxicity of Kokai River water to a freshwater shrimp (Paratya compressa improvisa) were monitored from 1989 to 1993. A 4-d toxicity test was conducted three times a week from April to August from 1989 to 1993 to measure mortality. Seventeen pesticides were analyzed during the biological monitoring. Expected shrimp mortalities were calculated by adding mortalities caused by each insecticide at the measured concentrations. Shrimp mortalities increased in late May to mid-June and could be attributed to additive effects of insecticides such as pyridaphenthion, malathion, and fenobucarb. Mortalities decreased toward the end of June but increased again from July to mid-August and could be attributed to insecticides such as diazinon or fenobucarb, which drifted directly into the river after aerial pesticide spraying on paddy fields. High mortalities decreased rapidly after heavy rains in August.
Issue includes papers from the Silver Toxicity Symposium.
Language: English
English
Publication Type: Journal Article
Classification: Q5 01504 Effects on organisms
Classification: SW 3030 Effects of pollution
Classification: P 2000 FRESHWATER POLLUTION
Classification: X 24136 Environmental impact
Classification: X 24221 Toxicity testing
Subfile: Pollution Abstracts; ASFA 3: Aquatic Pollution & Environmental Quality; Water Resources Abstracts; Toxicology Abstracts

Shigeshisa, H. and Shiraishi, H. (1998). Biomonitoring with shrimp to detect seasonal change in river water toxicity. Environmental Toxicology and Chemistry 17 : 687-694.

Chem Codes: SZ,MLT Rejection Code: MIXTURE.

ABSTRACT: BIOSIS COPYRIGHT: BIOL ABS. Seasonal changes in toxicity of Kokai River water to a freshwater shrimp (Paratya compressa improvisa) were monitored from 1989 to 1993. A 4-d toxicity test was conducted three times a week from April to August from 1989 to 1993 to measure mortality. Seventeen pesticides were analyzed during the biological monitoring. Expected shrimp mortalities were calculated by adding mortalities caused by each insecticide at the measured concentrations. Shrimp mortalities increased in late May to mid-June and could be attributed to additive effects of insecticides such as pyridaphenthion, malathion, and fenobucarb. Mortalities decreased toward the end of June but increased again from July to mid-August and could be attributed to insecticides such as diazinon or fenobucarb, which drifted directly into the river after aerial pesticide spraying on paddy fields. High mortalities decreased rapidly after heavy rains in August.

KEYWORDS: Ecology
KEYWORDS: Ecology
KEYWORDS: Ecology
KEYWORDS: Biochemical Studies-General
KEYWORDS: Pathology
KEYWORDS: Toxicology-Environmental and Industrial Toxicology
KEYWORDS: Public Health: Environmental Health-Air
KEYWORDS: Pest Control
KEYWORDS: Invertebrata
KEYWORDS: Malacostraca

Shin, S. W., Chung, N. I., Kim, J. S., Chon, T. S., Kwon, O. S., Lee, S. K., and Koh (2001). Effect of Diazinon on Behavior of Japanese Medaka (Oryzias latipes) and Gene Expression of Tyrosine Hydroxylase as a Biomarker. J.Environ.Sci.Health Part B 36: 783-795.

EcoReference No.: 85508

Chemical of Concern: DZ; Habitat: A; Effect Codes: BEH,CEL; Rejection Code: NO ENDPOINT(DZ).

Shiraishi, H., Pula, F., Otsuki, A., and Iwakuma, T. (1988). BEHAVIOR OF PESTICIDES IN LAKE KASUMIGAURA JAPAN. Sci Total Environ 72 : 29-42.

Chem Codes: MLT Rejection Code: SURVEY, MIXTURE.

ABSTRACT: BIOSIS COPYRIGHT: BIOL ABS. RRM RICE PADDY FIELD OXADIAZON DIAZINON SIMETRYNE BENTHIOCARB ISOPROTHIOLANE PERSISTENCE MOBILITY SURFACE RUNOFF

KEYWORDS: Ecology
KEYWORDS: Ecology
KEYWORDS: Movement (1971- )
KEYWORDS: Toxicology-Environmental and Industrial Toxicology
KEYWORDS: Public Health: Environmental Health-Air
KEYWORDS: Agronomy-Grain Crops
KEYWORDS: Pest Control

Shiraishi, Hiroaki, Pula, Flutra, Otsuki, Akira, and Iwakuma, Toshio (1988). Behaviour of pesticides in Lake Kasumugaura, Japan. The Science of The Total Environment 72: 29-42.

Chem Codes: Chemical of Concern: DZ Rejection Code: FATE.

Pesticides such as oxadiazon, isoprothiolane, diazinon, IBP, simetryne and benthiocarb, from surface runoff from rice paddy fields to Lake Kasumigaura, Japan were examined in order to determine seasonal changes in their concentrations in the lake water. The highest concentrations were observed near the river mouths during May to August, soon after pesticide application; hence they are transported mainly by surface runoff. Although these pesticides have been reported to be labile, concentrations of some of them, dispersed with the movement of the water, did not decrease rapidly in the natural aquatic environment. The highest concentrations, in 1985, of oxadiazon, isoprothiolane, diazinon, IBP, simetryne, benthiocarb and CSB were 0.66, 0.84, 0.16, 3.24, 3.23, 2.15 and 1.13 ppb, respectively. The relative order of persistence and mobility of pesticides in the lake water was estimated as: isoprothiolane, CSB, simetryne > IBP > diazinon >> oxadiazon > benthiocarb.

Shishido, Takashi and Fukami, Jun-ichi (1972). Enzymatic hydrolysis of diazoxon by rat tissue homogenates. Pesticide Biochemistry and Physiology 2: 39-50.