Groundwater quality and the relation between pH values and occurrence of trace elements and radionuclides in water samples collected from private wells in part of the Kickapoo Tribe of Oklahoma Jurisdictional Area, central Oklahoma, 2011

USGS Publications Warehouse

Becker, Carol J.

2013-01-01

From 1999 to 2007, the Indian Health Service reported that gross alpha-particle activities and concentrations of uranium exceeded the Maximum Contaminant Levels for public drinking-water supplies in water samples from six private wells and two test wells in a rural residential neighborhood in the Kickapoo Tribe of Oklahoma Jurisdictional Area, in central Oklahoma. Residents in this rural area use groundwater from Quaternary-aged terrace deposits and the Permian-aged Garber-Wellington aquifer for domestic purposes. Uranium and other trace elements, specifically arsenic, chromium, and selenium, occur naturally in rocks composing the Garber-Wellington aquifer and in low concentrations in groundwater throughout its extent. Previous studies have shown that pH values above 8.0 from cation-exchange processes in the aquifer cause selected metals such as arsenic, chromium, selenium, and uranium to desorb (if present) from mineral surfaces and become mobile in water. On the basis of this information, the U.S. Geological Survey, in cooperation with the Kickapoo Tribe of Oklahoma, conducted a study in 2011 to describe the occurrence of selected trace elements and radionuclides in groundwater and to determine if pH could be used as a surrogate for laboratory analysis to quickly and inexpensively identify wells that might contain high concentrations of uranium and other trace elements. The pH and specific conductance of groundwater from 59 private wells were measured in the field in an area of about 18 square miles in Lincoln and Pottawatomie Counties. Twenty of the 59 wells also were sampled for dissolved concentrations of major ions, trace elements, gross alpha-particle and gross beta-particle activities, uranium, radium-226, radium-228, and radon-222 gas. Arsenic concentrations exceeded the Maximum Contaminant Level of 10 micrograms per liter in one sample having a concentration of 24.7 micrograms per liter. Selenium concentrations exceeded the Maximum Contaminant Level of 50 micrograms per liter in one sample having a concentration of 147 micrograms per liter. Both samples had alkaline pH values, 8.0 and 8.4, respectively. Uranium concentrations ranged from 0.02 to 383 micrograms per liter with 5 of 20 samples exceeding the Maximum Contaminant Level of 30 micrograms per liter; the five wells with uranium concentrations exceeding 30 micrograms per liter had pH values ranging from 8.0 to 8.5. Concentrations of uranium and radon-222 and gross alpha-particle activity showed a positive relation to pH, with the highest concentrations and activity in samples having pH values of 8.0 or above. The groundwater samples contained dissolved oxygen and high concentrations of bicarbonate; these characteristics are also factors in increasing uranium solubility. Concentrations of radium-226 and radium-228 (combined) ranged from 0.03 to 1.7 picocuries per liter, with a median concentration of 0.45 picocuries per liter for all samples. Radon-222 concentrations ranged from 95 to 3,600 picocuries per liter with a median concentration of 261 picocuries per liter. Eight samples having pH values ranging from 8.0 to 8.7 exceeded the proposed Maximum Contaminant Level of 300 picocuries per liter for radon-222. Eight samples exceeded the 15 picocuries per liter Maximum Contaminant Level for gross alpha-particle activity at 72 hours (after sample collection) and at 30 days (after the initial count); those samples had pH values ranging from 8.0 to 8.5. Gross beta-particle activity increased in 15 of 21 samples during the interval from 72 hours to 30 days. The increase in gross beta-particle activity over time probably was caused by the ingrowth and decay of uranium daughter products that emit beta particles. Water-quality data collected for this study indicate that pH values above 8.0 are associated with potentially high concentrations of uranium and radon-222 and high gross alpha-particle activity in the study area. High pH values also are associated with potentially high concentrations of arsenic, chromium, and selenium in groundwater when these elements occur in the aquifer matrix along groundwater-flow paths.

Dietary biomagnification of organochlorine contaminants in Alaskan polar bears

USGS Publications Warehouse

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

2008-01-01

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

Stable isotope tracers of water vapor sources in the Atacama Desert, Northern Chile: a pilot study on the Chajnantor Plateau

NASA Astrophysics Data System (ADS)

Samuels, K. E.; Galewsky, J.; Sharp, Z. D.; Rella, C.; Ward, D.

2010-12-01

Subtropical deserts form in response to the interaction of large-scale processes, including atmospheric circulation and oceanic currents, with local features like topography. The degree to which each of these factors controls desert formation and the anticipated impacts of variations in each as climate changes, however, are poorly understood. Stable isotope compositions of water vapor in desert air can help to distinguish between moisture sources and processes that control aridity. The Atacama Desert, located in northern Chile between latitudes 23S and 27S, provides a natural laboratory in which to test the degree to which water vapor isotopologues enable the distinction between processes that control humidity, including the Hadley Circulation, the cold Humboldt Current off the coast of Chile, and the orographic effect of the Andes, in this subtropical desert. Water vapor isotopologues and concentrations were measured in real time using a cavity-ringdown spectrometer deployed on the Chajnantor Plateau over a three-week period from mid-July early August 2010. The elevation of the Plateau, 5000 m amsl (~550 hPa), places it above the boundary layer, allowing the evaluation of the Rayleigh fractionation model from the coast inland. Values reported by the instrument were verified with air samples taken at the coast and the Plateau, which were analyzed on an MAT-252 mass spectrometer. Water vapor concentrations and δD values varied spatially and temporally. Water vapor concentrations on the Plateau ranged from 200 to 3664 ppmv with a mean value of 536 ppmv. In contrast, water vapor concentrations at the coast were approximately 10000 ppmv, and at Yungay, 60 km inland, water vapor concentrations ranged from 1300 to 2000 ppmv from morning to evening. δD values on the Plateau ranged from -526‰ to -100‰ with a mean value of 290‰ with enriched values correlated to periods with higher water vapor concentrations. There are no strong diurnal variations in water vapor concentrations and corresponding δD values on the Plateau, however, water vapor concentrations generally increase after sunrise and reach their maxima in the evening. Temperatures on the Plateau were consistently around 0 degrees C during the pilot study with dewpoint temperatures around -20 degrees C and specific humidity ranging from 0.20 to 2.0 g/kg. Within this range of specific humidity, the Rayleigh fractionation model predicts δD values between -570‰ and -300‰. Preliminary results from this pilot study show that δD values are more enriched than predicted by a Rayleigh fractionation curve for water originating at the ocean and moving inland to an elevation of 5000 m. Instead, δD for water vapor on the Chajnantor Plateau falls along a mixing curve between upper- and lower-troposphere sources. Long term monitoring is necessary to understand the complex interplay between atmospheric and oceanic processes combined with topography responsible for the both water vapor concentrations and δD values observed on the Chajnantor Plateau.

Concentration-Dependent Multiple Binding Sites on Saliva-Treated Hydroxyapatite for Streptococcus sanguis

PubMed Central

Gibbons, R. J.; Moreno, E. C.; Etherden, I.

1983-01-01

The influence of bacterial cell concentration on estimates of the number of binding sites and the affinity for the adsorption of a strain of Streptococcus sanguis to saliva-treated hydroxyapatite was determined, and the possible presence of multiple binding sites for this organism was tested. The range of concentrations of available bacteria varied from 4.7 × 106 to 5,960 × 106 cells per ml. The numbers of adsorbed bacteria increased over the entire range tested, but a suggestion of a break in an otherwise smooth adsorption isotherm was evident. Values for the number of binding sites and the affinity varied considerably depending upon the range of available bacterial concentrations used to estimate them; high correlation coefficients were obtained in all cases. The use of low bacterial cell concentrations yielded lower values for the number of sites and much higher values for the affinity constant than did the use of high bacterial cell concentrations. When data covering the entire range of bacterial concentrations were employed, values for the number of sites and the affinity were similar to those obtained by using only high bacterial cell concentrations. The simplest explanation for these results is that there are multiple binding sites for S. sanguis on saliva-treated hydroxyapatite surfaces. When present in low concentration, the streptococci evidently attach to more specific high-affinity sites which become saturated when higher bacterial concentrations are employed. The possibility of multiple binding sites was substantiated by comparing estimates of the adsorption parameters from a computer-simulated isotherm with those derived from the experimentally generated isotherm. A mathematical model describing bacterial adsorption to binary binding sites was further evidence for the existence of at least two classes of binding sites for S. sanguis. Far fewer streptococci adsorbed to experimental pellicles prepared from saliva depleted of bacterial aggregating activity when low numbers of streptococci were used, but the magnitude of this difference was considerably less when high streptococcal concentrations were employed. This suggests an association between salivary components which possess bacterial-aggregating activity and bacterial adsorption to high-affinity specific binding sites on saliva-treated hydroxyapatite surfaces. PMID:6822416

Novel method to assess antiretroviral target trough concentrations using in vitro susceptibility data.

PubMed

Acosta, Edward P; Limoli, Kay L; Trinh, Lan; Parkin, Neil T; King, Jennifer R; Weidler, Jodi M; Ofotokun, Ighovwerha; Petropoulos, Christos J

2012-11-01

Durable suppression of HIV-1 replication requires the establishment of antiretroviral drug concentrations that exceed the susceptibility of the virus strain(s) infecting the patient. Minimum plasma drug concentrations (C(trough)) are correlated with response, but determination of target C(trough) values is hindered by a paucity of in vivo concentration-response data. In the absence of these data, in vitro susceptibility measurements, adjusted for serum protein binding, can provide estimations of suppressive in vivo drug concentrations. We derived serum protein binding correction factors (PBCF) for protease inhibitors, nonnucleoside reverse transcriptase inhibitors, and an integrase inhibitor by measuring the effect of a range of human serum concentrations on in vitro drug susceptibility measured with the PhenoSense HIV assay. PBCFs corresponding to 100% HS were extrapolated using linear regression and ranged from 1.4 for nevirapine to 77 for nelfinavir. Using the mean 95% inhibitory concentration (IC(95)) for ≥1,200 drug-susceptible viruses, we calculated protein-bound IC(95) (PBIC(95)) values. PBIC(95) values were concordant with the minimum effective C(trough) values that were established in well-designed pharmacodynamic studies (e.g., indinavir, saquinavir, and amprenavir). In other cases, the PBIC(95) values were notably lower (e.g., darunavir, efavirenz, and nevirapine) or higher (nelfinavir and etravirine) than existing target recommendations. The establishment of PBIC(95) values as described here provides a convenient and standardized approach for estimation of the minimum drug exposure that is required to maintain viral suppression and prevent the emergence of drug-resistant variants, particularly when in vivo concentration-response relationships are lacking.

Novel Method To Assess Antiretroviral Target Trough Concentrations Using In Vitro Susceptibility Data

PubMed Central

Limoli, Kay L.; Trinh, Lan; Parkin, Neil T.; King, Jennifer R.; Weidler, Jodi M.; Ofotokun, Ighovwerha; Petropoulos, Christos J.

2012-01-01

Durable suppression of HIV-1 replication requires the establishment of antiretroviral drug concentrations that exceed the susceptibility of the virus strain(s) infecting the patient. Minimum plasma drug concentrations (Ctrough) are correlated with response, but determination of target Ctrough values is hindered by a paucity of in vivo concentration-response data. In the absence of these data, in vitro susceptibility measurements, adjusted for serum protein binding, can provide estimations of suppressive in vivo drug concentrations. We derived serum protein binding correction factors (PBCF) for protease inhibitors, nonnucleoside reverse transcriptase inhibitors, and an integrase inhibitor by measuring the effect of a range of human serum concentrations on in vitro drug susceptibility measured with the PhenoSense HIV assay. PBCFs corresponding to 100% HS were extrapolated using linear regression and ranged from 1.4 for nevirapine to 77 for nelfinavir. Using the mean 95% inhibitory concentration (IC95) for ≥1,200 drug-susceptible viruses, we calculated protein-bound IC95 (PBIC95) values. PBIC95 values were concordant with the minimum effective Ctrough values that were established in well-designed pharmacodynamic studies (e.g., indinavir, saquinavir, and amprenavir). In other cases, the PBIC95 values were notably lower (e.g., darunavir, efavirenz, and nevirapine) or higher (nelfinavir and etravirine) than existing target recommendations. The establishment of PBIC95 values as described here provides a convenient and standardized approach for estimation of the minimum drug exposure that is required to maintain viral suppression and prevent the emergence of drug-resistant variants, particularly when in vivo concentration-response relationships are lacking. PMID:22964257

EC-QCL mid-IR transmission spectroscopy for monitoring dynamic changes of protein secondary structure in aqueous solution on the example of β-aggregation in alcohol-denaturated α-chymotrypsin.

PubMed

Alcaráz, Mirta R; Schwaighofer, Andreas; Goicoechea, Héctor; Lendl, Bernhard

2016-06-01

In this work, a novel EC-QCL-based setup for mid-IR transmission measurements in the amide I region is introduced for monitoring dynamic changes in secondary structure of proteins. For this purpose, α-chymotrypsin (aCT) acts as a model protein, which gradually forms intermolecular β-sheet aggregates after adopting a non-native α-helical structure induced by exposure to 50 % TFE. In order to showcase the versatility of the presented setup, the effects of varying pH values and protein concentration on the rate of β-aggregation were studied. The influence of the pH value on the initial reaction rate was studied in the range of pH 5.8-8.2. Results indicate an increased aggregation rate at elevated pH values. Furthermore, the widely accessible concentration range of the laser-based IR transmission setup was utilized to investigate β-aggregation across a concentration range of 5-60 mg mL(-1). For concentrations lower than 20 mg mL(-1), the aggregation rate appears to be independent of concentration. At higher values, the reaction rate increases linearly with protein concentration. Extended MCR-ALS was employed to obtain pure spectral and concentration profiles of the temporal transition between α-helices and intermolecular β-sheets. Comparison of the global solutions obtained by the modelled data with results acquired by the laser-based IR transmission setup at different conditions shows excellent agreement. This demonstrates the potential and versatility of the EC-QCL-based IR transmission setup to monitor dynamic changes of protein secondary structure in aqueous solution at varying conditions and across a wide concentration range. Graphical abstract EC-QCL IR spectroscopy for monitoring protein conformation change.

Analysis of Tank 38H (HTF-38-17-52, -53) and Tank 43H (HTF-43-17-54, -55) Samples for Support of the Enrichment Control and Corrosion Control Programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hay, M.; Coleman, C.; Diprete, D.

SRNL analyzed samples from Tank 38H and Tank 43H to support ECP and CCP. The total uranium in the Tank 38H surface sample was 41.3 mg/L while the sub-surface sample was 43.5 mg/L. The Tank 43H samples contained total uranium concentrations of 28.5 mg/L in the surface sample and 28.1 mg/L in the sub-surface sample. The U-235 percentage ranged from 0.62% to 0.63% for the Tank 38H samples and Tank 43H samples. The total uranium and percent U-235 results in the table appear slightly lower than recent Tank 38H and Tank 43H uranium measurements. The plutonium results in the tablemore » show a large difference between the surface and sub-surface sample concentrations for Tank 38H. The Tank 43H plutonium results closely match the range of values measured on previous samples. The Cs-137 results for the Tank 38H surface and sub-surface samples show similar concentrations slightly higher than the concentrations measured in recent samples. The Cs-137 results for the two Tank 43H samples also show similar concentrations within the range of values measured on previous samples. The four samples show silicon concentrations somewhat lower than the previous samples with values ranging from 124 to 168 mg/L.« less

Zonisamide serum concentrations during pregnancy.

PubMed

Reimers, Arne; Helde, Grethe; Becser Andersen, Noémi; Aurlien, Dag; Surlien Navjord, Elisabeth; Haggag, Kathrine; Christensen, Jakob; Lillestølen, Kari Mette; Nakken, Karl Otto; Brodtkorb, Eylert

2018-05-04

To investigate the change in zonisamide (ZNS) serum concentration and its consequences in pregnant women with epilepsy. Six hospitals in Norway and Denmark screened their records for women who had been using ZNS during pregnancy. Absolute serum concentrations as well as concentration/dose (CD)-ratios were compared to non-pregnant values. Descriptive data on seizure control and obstetrical data were also collected. 144 serum concentrations from 23 pregnancies in 15 individual women with epilepsy were included (six on monotherapy). The mean ZNS serum concentration fell to a minimum of 58.6 ± 15.1%, while the C/D-ratio fell to as low as 55.1 ± 15.3% of the non-pregnant-value. The lowest values were seen in gestational months six to nine, and the individual nadir varied considerably (range: 24-81% of the non-pregnant value). Four out of ten previously seizure-free patients experienced breakthrough seizures. Gestational age, weight at birth and head circumference of the newborns were within the reference ranges. ZNS serum concentrations may fall by over 40% during pregnancy, with large interindividual variability. In some patients, this may lead to worsened seizure control. These findings are in line with reports on other AEDs and suggest that regular therapeutic drug monitoring and dose adjustments may be useful. Copyright © 2018 Elsevier B.V. All rights reserved.

[Microbial exposure in collection of residential garbage--results of field studies].

PubMed

Neumann, H D; Balfanz, J

1999-01-01

Since 1995 the communal accident insurance carrier of the county Wetfalen-Lippe conducts investigations into the exposure to biological agents related to refuse collection. Total fungal exposure during refuse collection turned out to range from 10,000 up to 750,000 colony forming units per cubic meter. Most of the measurement values exceeded the limit of 50,000. During hot periods in the summertime, the concentration of Aspergillus fumigatus increased up to 90,000 cfu/m3. The mean values of the bacterial concentrations ranged from 15,000 up to 50,000 cfu/m3, the endotoxin concentration from 12 up to 59 EU/m3. In the driver's cabin fungal exposure sometimes exceeded 10,000 cfu/m3 especially in autumn and winter. Maximum values were 5,000 cfu/m3 for bacteria and 15 EU/m3 for endotoxins. High values were measured irrespective of the kind of refuse.

Ferromagnetic resonance and magnetic studies of cores 60009/60010 and 60003 - Compositional and surface-exposure stratigraphy. [of Apollo deep drill lunar samples

NASA Technical Reports Server (NTRS)

Morris, R. V.; Gose, W. A.

1976-01-01

Ferromagnetic resonance and static magnetic measurements were made on 131 samples from core 60009/60010 and on 40 samples from section 60003 of the Apollo 16 deep drill core. These studies provided depth profiles for composition, in terms of the concentration of FeO, and relative surface exposure age (or maturity), in terms of the values of the specific FMR intensity normalized to the FeO content. For core 60009/60010, the concentration of FeO ranged from about 1.6 wt.% to 5.8 wt.% with a mean value of 4.6 wt.% and the maturity ranged from immature to mature with most of the soils being submature. A systematic decrease in maturity from the lunar surface to a depth of about 12.5 cm was observed in core section 60010. For core section 60003, the concentration of FeO ranged from about 5.2 wt.% to 7.5 wt.% with a mean value of 6.4 wt.% and the maturity ranged from submature to mature with most of the soils being mature.

Boron contents and isotopic compositions of hog manure, selected fertilizers, and water in Minnesota

USGS Publications Warehouse

Komor, S.C.

1997-01-01

Boron-isotope (δ11B) values may be useful as surrogate tracers of contaminants and indicators of water mixing in agricultural settings. This paper characterizes the B contents and isotopic compositions of hog manure and selected fertilizers, and presents δ11B data for ground and surface water from two agricultural areas. Boron concentrations in dry hog manure averaged 61 mg/kg and in commercial fertilizers ranged from below detection limits in some brands of ammonium nitrate and urea to 382 mg/kg in magnesium sulfate. Values of δ11B of untreated hog manure ranged from 7.2 to 11.2o/oo and of N fertilizers were −2.0 to 0.7o/oo. In 22 groundwater samples from a sand-plain aquifer in east-central Minnesota, B concentrations averaged 0.04 mg/L and δ11B values ranged from 2.3 to 41.5o/oo. Groundwater beneath a hog feedlot and a cultivated field where hog manure was applied had B-isotope compositions consistent with the water containing hog-manure leachate. In a 775-km2 watershed with silty-loam soils in southcentral Minnesota: 18 samples of subsurface drainage from corn (Zea mays L.) and soybean (Glycine max L. Merr.) fields had average B concentrations of 0.06 mg/L and δ11B values of 5.3 to 15.1o/oo; 27 stream samples had average B concentrations of 0.05 mg/L and δ11B values of 1.0 to 19.0o/oo; and eight groundwater samples had average B concentrations of 0.09 mg/L and δ11B values of −0.3 to 23.0o/oo. Values of δ11B and B concentrations, when plotted against one another, define a curved mixing trend that suggests subsurface drainage and stream water contain mixtures of B from shallow and deep groundwater.

Distribution of Thorium, Cesium, Yttrium and Zirconium in Alfisol pedons in the Catalan Coastal Range (NE Spain)

NASA Astrophysics Data System (ADS)

Bech, J.; Rustullet, J.; Tume, P.; Roca, N.; Tobias, F. J.; Garrigó, J.; Reverter, F.; Sánchez, P.

2012-04-01

The aim of this study is to estimate the concentrations and vertical distributions of Th, Ce, Y, and Zr in eleven Alfisol pedons from the NE Garraf Coastal massif (Catalonia, NE Spain). These soils were developed mainly on Mesozoic limestones. The concentrations were determined by XRF and the results were then compared to soil properties (pH, organic carbon content, CaCO3, particle size distribution and Fe forms: total iron, Fet, dithionite-extractable iron, Fed and oxalate-extractable iron,Feo). The range of Th values is: min 3 mgkg-1, max 16 mgkg-1, mean 10.4 mgkg-1 and median 11 mgkg-1. The range of Ce values is: min 22 mgkg-1, max 116 mgkg-1, mean 73.9 mgkg-1 and median 76 mgkg-1. The range of Y values is: min 10 mgkg-1, max 43 mgkg-1, mean 27.5 mgkg-1 and median 27 mgkg-1. The range of Zr values is: min 101 mgkg-1, max 418 mgkg-1, mean 253 mgkg-1 and median 252 mgkg-1. The Th concentrations obtained are similar to world soil and NASC values. These concentration data of Th, Ce, Y and Zr were correlated with each other and with the soil properties. Th correlates positively with Ce (0.95), Y (0.92), Zr (0.80), Fet (0.75), Fed (0.85) and Fed-Feo (0.85), clay% (0.55) and silt% (0.31) and negatively with sand% and CaCO3. The correlations do not indicate any significant relationship between Th and organic carbon or Feo. The ranking of the horizons by Th concentration is: BC hor. (12.5 mgkg-1), Bt hor. (11 mgkg-1), A hor. (10.1 mgkg-1) and finally C horizons (7.2 mgkg-1). The ranking of the Alfisols by Th concentration, taking into account the litology is: those derived from limestones (14.5 mgkg-1), those derived from schists (12.5 mgkg-1), those originated over dolomites (11.8 mgkg-1), those developed over Pleistocene colluvium (9.2 mgkg-1) and finally those originated over Keuper marls (6 mgkg-1).

Activity concentration, transfer factors and resultant radiological risk of 226Ra, 232Th, and 40K in soil and some vegetables consumed in Selangor, Malaysia

NASA Astrophysics Data System (ADS)

Solehah, A. R.; Yasir, M. S.; Samat, S. B.

2016-11-01

The activity concentrations of the natural radionuclides 226Ra, 232Th, and 40K were determined in vegetable crops consumed by Malaysian people in Sungai Besar, Selangor. Sample of vegetables and the soil where the crops were cultivated and collected at five different location. The activity concentrations in Bq/kg of 226Ra, 232Th, and 40K were measured by the gamma-ray spectroscopy using the high purity germanium detector. The range activity concentration in soil is between 51.81 and 71.84 Bq/kg, 64.18 and 78.00 Bq/kg, and 210.49 and 244.29 Bq/kg for 226Ra, 232Th, and 40K, respectively. The activity concentration of 226Ra, 232Th, and 40K in vegetables were found to be in the range of 2.06 to 5.44 Bq/kg, Not Detectable to 0.61 Bq/kg, and 101.00 to 1223.09 Bq/kg, respectively. The activity concentration in both soil and vegetables were all less than lower limit stated by UNSCEAR. The Transfer Factors range value for 226Ra, 232Th, and 40K varied from 0.02 to 0.06, 0.003 to 0.008, and 1.79 to 5.19 respectively. Radium equivalent for soil range from 165.57 to 194.84 Bq/kg. It was within the international accepted value (370 Bq/kg). Absorb dose rate for soil range between 73.5 to 86.40 nGyh-1, in safe range from limit of international accepted value (55nGyh-1). Effective dose rate is found to be in range of 0.09 to 0.11 mSvy-1 for soil which is less than 2.4 mSv/y. External and Internal Hazard indices of soil was all below 1, within agreement of other researcher and UNSCEAR. The estimation of the consequent radiological risk due to the presence of those radionuclides is significantly low.

Evaluation of the thyroid status of Basenji dogs in Australia.

PubMed

Seavers, A; Snow, D H; Mason, K V; Malik, R

2008-11-01

To determine the thyroid status of Basenji dogs in Australia. Jugular or cephalic venipuncture blood samples were taken from 113 Basenji, comprising 47 males, 5 castrates, 48 entire and 13 spayed bitches, and sent on ice in plain and EDTA tubes to a single laboratory to determine haematocrit and serum concentrations of total thyroid hormone (thyroxine, TT4), thyroid-stimulating hormone (TSH) and cholesterol. In a subgroup of 8 dogs with abnormal elevated TSH concentrations and subnormal TT4 concentrations, 5 were further examined by dynamic endocrine testing using recombinant human (rh) TSH (54 microg). Ages ranged from 1 to 14 years and weight range was 6.5 to 14.0 kg. TT4 concentrations (nmol/L) ranged from 2 to 27, with a median of 13 and a mean +/- SD of 13.0 +/- 5.7. Importantly, 85/113 (75%) of TT4 values were lower than the normal laboratory reference range (17-37). TSH concentrations (ng/mL) ranged from 0.05 to 5.37, with a median of 0.16 and a mean +/- SD of 0.3 +/- 0.6. Basenji have a similar reference range for serum TSH, but a considerably lower reference range for TT4 (2-27 nmol/L) than most breeds and crossbreds, resembling the sight hounds in this respect. Given the difficulty of accurately measuring TT4 concentrations that are so low, concomitant serial TSH determinations are essential to properly asses thyroid function. Taken alone, TT4 determinations are only of use when the value is within the reference range, in which case a diagnosis of hypothyroidism is likely excluded.

Fluoride Content of Bottled Waters in Hong Kong and Qatar.

PubMed

Al-Mulla, Hessa I; Anthonappa, Robert P; King, Nigel M

2016-01-01

To determine the F concentration of bottled waters that was available in Hong Kong and Qatar. The F concentrations of bottled waters collected from Hong Kong (n=81) and Qatar (n=32) were analysed. The F ion selective electrode method was used to measure the F concentration in the samples. Three measurements were obtained for every sample to ensure reproducibility and appropriate statistical analyses were employed. Qatar group: F concentrations ranged from 0.06 ppm to 3.0 ppm with a mean value of 0.8 ppm. The F concentrations displayed on the labels of the samples (60%) were significantly lower than the measured F concentration (p < 0.0001). Hong Kong group: F concentrations ranged from 0.04 ppm to 2.52 ppm with a mean value of 0.44 ppm. The F concentrations displayed on the samples (16%) were significantly lower than the measured F concentration (p< 0.0001). Wide variations exist in the F concentration among the different brands of bottled water available in Hong Kong and Qatar. The F concentrations displayed on the labels were not consistent with the measured F concentrations.

Tracing chlorine sources of thermal and mineral springs along and across the Cascade Range using halogen and chlorine isotope compositions

USGS Publications Warehouse

Cullen, Jeffrey T.; Barnes, Jaime D.; Hurwitz, Shaul; Leeman, William P.

2015-01-01

In order to provide constraints on the sources of chlorine in spring waters associated with arc volcanism, the major/minor element concentrations and stable isotope compositions of chlorine, oxygen, and hydrogen were measured in 28 thermal and mineral springs along the Cascade Range in northwestern USA. Chloride concentrations in the springs range from 64 to 19,000 mg/L and View the MathML source values range from +0.2‰ to +1.9‰ (average=+1.0±0.4‰), with no systematic variation along or across the arc, nor correlations with their presumed underlying basement lithologies. Additionally, nine geochemically well-characterized lavas from across the Mt. St. Helens/Mt. Adams region of the Cascade Range (Leeman et al., 2004 and Leeman et al., 2005) were analyzed for their halogen concentrations and Cl isotope compositions. In the arc lavas, Cl and Br concentrations from the volcanic front are higher than in lavas from the forearc and backarc. F and I concentrations progressively decrease from forearc to backarc, similar to the trend documented for B in most arcs. View the MathML source values of the lavas range from −0.1 to +0.8‰ (average = +0.4±0.3‰). Our results suggest that the predominantly positive View the MathML source values observed in the springs are consistent with water interaction with underlying 37Cl-enriched basalt and/or altered oceanic crust, thereby making thermal spring waters a reasonable proxy for the Cl isotope compositions of associated volcanic rocks in the Cascades. However, waters with View the MathML source values >+1.0‰ also suggest additional contributions of chlorine degassed from cooling magmas due to subsurface vapor–liquid HCl fractionation in which Cl is lost to the aqueous fluid phase and 37Cl is concentrated in the ascending magmatic HCl vapor. Future work is necessary to better constrain Cl isotope behavior during volcanic degassing and fluid–rock interaction in order to improve volatile flux estimates through subduction zones.

A preliminary evaluation of sediment quality assessment values for freshwater ecosystems

USGS Publications Warehouse

Smith, Sherri L.; MacDonald, Donald D.; Keenleyside, Karen A.; Ingersoll, Christopher G.; Field, L. Jay

1996-01-01

Sediment quality assessment values were developed using a weight of evidence approach in which matching biological and chemical data from numerous modelling, laboratory, and field studies performed on freshwater sediments were compiled and analyzed. Two assessment values (a threshold effect level (TEL) and a probable effect level(PEL)) were derived for 23 substances, including eight trace metals, six individual polycyclic aromatic hydrocarbons (PAHs), total polychlorinated biphenyls (PCBs), and eight pesticides. The two values defined three ranges of chemical concentrations; those that were (1) rarely, (2) occasionally, and (3) frequently associated with adverse biological effects. An evaluation of the percent incidence of adverse biological effects within the three concentration ranges indicated that the reliability of the TELs (i.e., the degree to which the TELs represent concentrations within the data set below which adverse effects rarely occur) was consistently good. However, this preliminary evaluation indicated that most of the PELs were less reliable (i.e., they did not adequately represent concentrations within the data set above which adverse effects frequently occur). Nonetheless, these values were often comparable to other biological effects-based assessment values (which were themselves reliable), which increased the level of confidence that could be placed in our values. This method is being used as a basis for developing national sediment quality guidelines for freshwater systems in Canada and sediment effect concentrations as part of the Assessment and Remediation of Contaminated Sediments (ARCS) program in the Great Lakes.

Effects of long-term oral administration of levothyroxine sodium on serum thyroid hormone concentrations, clinicopathologic variables, and echocardiographic measurements in healthy adult horses.

PubMed

Frank, Nicholas; Buchanan, Benjamin R; Elliott, Sarah B

2008-01-01

To determine the effects of long-term oral levothyroxine sodium (L-T(4)) administration on serum thyroid hormone concentrations, thyroid gland function, clinicopathologic variables, and echocardiographic examination measurements in adult euthyroid horses. 6 healthy adult mares. Horses received L-T(4) (48 mg/d) orally for 48 weeks. Every 4 weeks, physical examinations were performed; blood samples were collected for CBC, plasma biochemical analyses, and assessments of serum total triiodothyronine (tT(3)) and thyroxine (tT(4)) concentrations. Plasma creatine kinase MB activity and cardiac troponin I concentration were also measured. Echocardiographic examinations were performed before and at 16, 32, and 48 weeks during the treatment period. During the treatment period, mean body weight decreased significantly; heart rate varied significantly, but the pattern of variation was not consistent. Significant time effects were detected for certain clinicopathologic variables, but mean values remained within reference ranges. Cardiac troponin I was only detectable in 8 of 24 plasma samples (concentration range, 0.01 to 0.03 ng/mL). Serum creatine kinase MB activity did not change significantly over time. Compared with the pretreatment value, 5.4-, 4.0-, and 3.7-fold increases in mean serum tT(4) concentrations were detected at 16, 32, and 48 weeks, respectively. Some cardiac measurements changed significantly over time, but mean values remained within published reference ranges. Mean fractional shortening was lower than the pretreatment mean value at 16 and 32 weeks. In horses, long-term oral administration of 48 mg of L-T(4)/d significantly increased serum tT(4) concentrations and did not appear to adversely affect health.

Uptake of 40K and 137Cs in native plants of the Marshall Islands.

PubMed

Simon, S L; Graham, J C; Terp, S D

2002-01-01

Uptake of 137Cs and 40K was studied in seven native plant species of the Marshall Islands. Plant and soil samples were obtained across a broad range of soil 137Cs concentrations (0.08-3900 Bq/kg) and a narrower range of 40K soil concentrations (2.3-55 Bq/kg), but with no systematic variation of 40K relative to 137Cs. Potassium-40 concentrations in plants varied little within the range of 40K soil concentrations observed. Unlike the case for 40K, 137Cs concentrations increased in plants with increasing 137Cs soil concentrations though not precisely in a proportionate manner. The best-fit relationship between soil and plant concentrations was P = aSb where a and b are regression coefficients and P and S are plant and soil concentrations, respectively. The exponent b for 40K was zero, implying plant concentrations were a single value, while b for 137Cs varied between 0.51 and 0.82, depending on the species. For both 40K and 137Cs, we observed a decreasing concentration ratio (where concentration ratio=plant concentration/soil concentration) with increasing soil concentrations. For the CR values, the best-fit relationship was of the form CR = aSb/S = aSb(-1). For the 40K CR functions, the exponent b - 1 was close to - 1 for all species. For the 137Cs CR functions, the exponent b - 1 varied from -0.19 to -0.48. The findings presented here, aswell as those by other investigators, collectively argue against the usefulness of simplistic ratio models to accurately predict uptake of either 40K or 137Cs in plants over wide ranges of soil concentration.

A viscometric approach of pH effect on hydrodynamic properties of human serum albumin in the normal form.

PubMed

Monkos, Karol

2013-03-01

The paper presents the results of viscosity determinations on aqueous solutions of human serum albumin (HSA) at isoelectric point over a wide range of concentrations and at temperatures ranging from 5°C to 45°C. On the basis of a modified Arrhenius equation and Mooney's formula some hydrodynamic parameters were obtained. They are compared with those previously obtained for HSA in solutions at neutral pH. The activation energy and entropy of viscous flow and the intrinsic viscosity reach a maximum value, and the effective specific volume, the self-crowding factor and the Huggins coefficient a minimum value in solutions at isoelectric point. Using the dimensionless parameter [η]c, the existence of three ranges of concentrations: diluted, semi-diluted and concentrated, was shown. By applying Lefebvre's relation for the relative viscosity in the semi-dilute regime, the Mark-Houvink-Kuhn-Sakurada (MHKS) exponent was established. The analysis of the results obtained from the three ranges of concentrations showed that both conformation and stiffness of HSA molecules in solutions at isoelectric point and at neutral pH are the same.

High extracellular concentration of excitatory amino acids glutamate and aspartate in human brain abscess.

PubMed

Dahlberg, Daniel; Ivanovic, Jugoslav; Hassel, Bjørnar

2014-04-01

Brain abscesses often cause symptoms of brain dysfunction, including seizures, suggesting interference with normal neurotransmission. We determined the concentration of extracellular neuroactive amino acids in brain abscesses from 16 human patients. Glutamate was present at 3.6 mmol/L (median value, range 0.5-10.8), aspartate at 1.0 mmol/L (range 0.09-6.8). For comparison, in cerebroventricular fluid glutamate was ∼0.6 μmol/L, and aspartate was not different from zero. The total concentration of amino acids was higher in eight patients with seizures: 66 mmol/L (median value, range 19-109) vs. 21 mmol/L (range 4-52) in eight patients without seizures (p=0.026). The concentration of aspartate and essential amino acids tryptophan, phenylalanine, tyrosine, leucine, and isoleucine was higher in pus from patients with seizures (p⩽0.040), whereas that of glutamate was not (p=0.095). The median concentration of the non-proteinogenic, inhibitory amino acid taurine was similar in the two groups, 0.7-0.8 mmol/L (range 0.1-6.1). GABA could not be detected in pus. The patient groups did not differ with respect to abscess volume, the cerebral lobe affected, age, or time from symptom onset to surgery. Seven patients with extracerebral, intracranial abscesses had significantly lower pus concentration of glutamate (352 μmol/L, range 83-1368) and aspartate (71 μmol/L, range 22-330) than intracerebral abscesses (p<0.001). We conclude that excitatory amino acids glutamate and aspartate may reach very high concentrations in brain abscesses, probably contributing to symptoms through activation of glutamate receptors in the surrounding brain tissue. Copyright © 2014 Elsevier Ltd. All rights reserved.

Indoor 222Rn measurement and hazards indices in houses of Al-Najaf province - Iraq

NASA Astrophysics Data System (ADS)

Ebrahiem, Sameera A.; Falih, Esraa H.; Mahdi, Hind Abdul Majeed; Shaban, Auday H.

2018-05-01

In this paper, the measurement the 222Rn concentrations for different houses in ten reigns for Al-Najaf province, 222Rn concentrations were measurement by using RAD-7 detector. The results indicate that, the less value of 222Rn concentrations was found in Al-Motanaby region which was (88 Bq/m3), while the highest value of 222Rn concentrations was found in Al-Forat region which was (193 Bq/m3), with average value of (143.4±27.6 Bq/m3), all the results are less than the recommended range from value of (200-300 Bq/m3). The radiation hazard indices [PAEC, EP, AED and CPPP] also found to be less than the global limit

Indirect spectrophotometric determination of traces of bromide in water

USGS Publications Warehouse

Fishman, M. J.; Skougstad, M.W.

1963-01-01

A rapid, accurate, and sensitive indirect spectrophotometric method for the determination of bromide in natural waters is based on the catalytic effect of bromide on the oxidation of iodine to iodate by potassium permanganate in sulfuric acid solution. The method is applicable to concentrations ranging from 1 to 100 ??g. of bromide per liter, but may be modified to extend the concentration range. Most ions commonly occurring in water do not interfere. The standard deviation is 2.9 at bromide concentrations of 100 ??g. per liter and less at lower concentrations. The determination of bromide in samples containing known added amounts gave values ranging from 99 to 105% of the concentration calculated to be present.

In vitro activity of heather [Calluna vulgaris (L.) Hull] extracts on selected urinary tract pathogens

PubMed Central

Vučić, Dragana M.; Petković, Miroslav R.; Rodić-Grabovac, Branka B.; Stefanović, Olgica D.; Vasić, Sava M.; Čomić, Ljiljana R.

2014-01-01

Calluna vulgaris L. Hull (Ericaceae) has been used for treatment of urinary tract infections in traditional medicine. In this study we analyzed in vitro antibacterial activity of the plant extracts on different strains of Escherichia coli, Enterococcus faecalis and Proteus vulgaris, as well as the concentrations of total phenols and flavonoids in the extracts. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The concentrations of total phenols were examined by using Folin-Ciocalteu reagent and ranged between 67.55 to 142.46 mg GAE/g. The concentrations of flavonoids in extracts were determined using spectrophotometric method with aluminum chloride and the values ranged from 42.11 to 63.68 mg RUE/g. The aqueous extract of C. vulgaris showed a significant antibacterial activity. The values of MIC were in the range from 2.5 mg/ml to 20 mg/ml for this extract. Proteus vulgaris strains were found to be the most sensitive. The results obtained suggest that all tested extracts of C. vulgaris inhibit the growth of human pathogens, especially the aqueous extract. PMID:25428676

In vitro activity of heather [Calluna vulgaris (L.) Hull] extracts on selected urinary tract pathogens.

PubMed

Vučić, Dragana M; Petković, Miroslav R; Rodić-Grabovac, Branka B; Stefanović, Olgica D; Vasić, Sava M; Comić, Ljiljana R

2014-11-15

Calluna vulgaris L. Hull (Ericaceae) has been used for treatment of urinary tract infections in traditional medicine. In this study we analyzed in vitro antibacterial activity of the plant extracts on different strains of Escherichia coli, Enterococcus faecalis and Proteus vulgaris, as well as the concentrations of total phenols and flavonoids in the extracts. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The concentrations of total phenols were examined by using Folin-Ciocalteu reagent and ranged between 67.55 to 142.46 mg GAE/g. The concentrations of flavonoids in extracts were determined using spectrophotometric method with aluminum chloride and the values ranged from 42.11 to 63.68 mg RUE/g. The aqueous extract of C. vulgaris showed a significant antibacterial activity. The values of MIC were in the range from 2.5 mg/ml to 20 mg/ml for this extract. Proteus vulgaris strains were found to be the most sensitive. The results obtained suggest that all tested extracts of C. vulgaris inhibit the growth of human pathogens, especially the aqueous extract.

Integrating geophysical data for mapping the contamination of industrial sites by polycyclic aromatic hydrocarbons: A geostatistical approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colin, P.; Nicoletis, S.; Froidevaux, R.

1996-12-31

A case study is presented of building a map showing the probability that the concentration in polycyclic aromatic hydrocarbon (PAH) exceeds a critical threshold. This assessment is based on existing PAH sample data (direct information) and on an electrical resistivity survey (indirect information). Simulated annealing is used to build a model of the range of possible values for PAH concentrations and of the bivariate relationship between PAH concentrations and electrical resistivity. The geostatistical technique of simple indicator kriging is then used, together with the probabilistic model, to infer, at each node of a grid, the range of possible values whichmore » the PAH concentration can take. The risk map is then extracted for this characterization of the local uncertainty. The difference between this risk map and a traditional iso-concentration map is then discussed in terms of decision-making.« less

Assessment of natural radioactivity and radiation hazard indices in soil samples of East Khasi Hills District, Meghalaya, India

NASA Astrophysics Data System (ADS)

Lyngkhoi, B.; Nongkynrih, P.

2018-04-01

The Activity Concentrations of naturally occurring radionuclides such as 40K, 238U and 232Th were determined from 20 (twenty) villages of East Khasi Hills District of Meghalaya, India using gamma-ray spectroscopy. This District is adjacent to the South-West Khasi Hills District located in the same state where heavy deposit of uranium has been identified [1]. The measured activities of 40K, 238U and 232Th were found ranging from 93.4 to 606.3, 23.2 to 140.9 and 25.1 to 158.9 Bq kg-1 with their average values of 207.9, 45.6 and 63.8 Bq kg-1, respectively. The obtained value of activity concentration for 40K is lower than the world average value 400.0 Bq kg-1 while for 238U and 232Th, the average concentrations are above the world average values 35.0 and 30.0 Bq kg-1, respectively. The calculated Absorbed Dose Rate gamma-radiation of the natural radionuclides ranged from 37.4 to 186.5 nGy h-1 with an average of 71.3 nGy h-1. The outdoor Annual Effective Dose Rate received by an individual ranged from 50.0-230.0 µSv y-1 with an average value of 87.5 µSv y-1. The physical and chemical properties of the soil have no effects on the naturally occurring radionuclides concentrations. This has been revealed by the results obtained as there is no positive correlation between physical/chemical parameters and the radionuclides concentrations in the soil samples [2]. It is observed that good positive correlations among the radionuclides concentrations and with the measured dose rate prevail. The findings show that the values of external and internal hazard indices resulting from the measured activity concentrations of natural radionuclides in soil from the collected sampling areas are less than the International Recommended safety limits of 1 (unity) with the exception of Mylliem (1.12) where the External hazard index is slightly higher.

Concentration of Ra-226 in Malaysian Drinking and Bottled Mineral Water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amin, Y. B. Mohd; Jemangin, M. H.; Mahat, R. H.

2010-07-07

The concentration of the radionuclide {sup 226}Ra was determined in the drinking water which was taken from various sources. It was found that the concentration varies from non-detectable (ND) to highest value of 0.30 Bq per liter. The concentration was found to be high in mineral water as compare with surface water such as domestic pipe water. Some of these values have exceeded the EPA (Environmental Protection Agency) of America regulations. The activity concentrations obtained are compared with data from other countries. The estimated annual effective doses from drinking the water are determined. The values obtained range from 0.02 mSvmore » to about 0.06 mSv per year.« less

Phytochemical, antimicrobial, and antioxidant activities of different citrus juice concentrates.

PubMed

Oikeh, Ehigbai I; Omoregie, Ehimwenma S; Oviasogie, Faith E; Oriakhi, Kelly

2016-01-01

The search for new antimicrobial compounds is ongoing. Its importance cannot be overemphasized in an era of emerging resistant pathogenic organisms. This study therefore investigated the phytochemical composition and antioxidant and antimicrobial activities of different citrus juice concentrates. Fruit juices of Citrus tangerine (tangerine), Citrus paradisi (grape), Citrus limon (lemon), and Citrus aurantifolia (lime) were evaluated. Antimicrobial activities against five bacterial and three fungal strains were evaluated. The results revealed the presence of alkaloids, flavonoids, steroids, terpenoids, saponins, cardiac glycosides, and reducing sugars in all the juice concentrates. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging capacities varied with tangerine and grape juices having better scavenging capacities than lemon and lime juices. Grape juice was observed to have a significantly higher (P < 0.05) ferric-reducing antioxidant potential (FRAP) value (364.2 ± 10.25 μmol/L Fe(II)/g of the extract) than the reference antioxidant, ascorbic acid (312.88 ± 5.61 μmol/L). Antimicrobial studies revealed differential antimicrobial activities against different microbial strains. Zones of inhibition ranging from 4 to 26 mm were observed for the antibacterial tests with 0-24 mm for antifungal test. Minimum inhibitory concentrations (MIC) and minimum bacteriostatic concentrations (MBC) for concentrates against bacterial strains ranged from 12.5 to 200 μg/mL. Lemon and lime juice concentrates had lower MIC and MBC values with orange and tangerine having the highest values. Minimum fungicidal concentrations ranged from 50 to 200 μg/mL. The results of this study suggest that these juice concentrates may have beneficial antimicrobial roles that can be exploited in controlling unwanted microbial growth.

Chemical-specific screening criteria for interpretation of biomonitoring data for volatile organic compounds (VOCs)--application of steady-state PBPK model solutions.

PubMed

Aylward, Lesa L; Kirman, Chris R; Blount, Ben C; Hays, Sean M

2010-10-01

The National Health and Nutrition Examination Survey (NHANES) generates population-representative biomonitoring data for many chemicals including volatile organic compounds (VOCs) in blood. However, no health or risk-based screening values are available to evaluate these data from a health safety perspective or to use in prioritizing among chemicals for possible risk management actions. We gathered existing risk assessment-based chronic exposure reference values such as reference doses (RfDs), reference concentrations (RfCs), tolerable daily intakes (TDIs), cancer slope factors, etc. and key pharmacokinetic model parameters for 47 VOCs. Using steady-state solutions to a generic physiologically-based pharmacokinetic (PBPK) model structure, we estimated chemical-specific steady-state venous blood concentrations across chemicals associated with unit oral and inhalation exposure rates and with chronic exposure at the identified exposure reference values. The geometric means of the slopes relating modeled steady-state blood concentrations to steady-state exposure to a unit oral dose or unit inhalation concentration among 38 compounds with available pharmacokinetic parameters were 12.0 microg/L per mg/kg-d (geometric standard deviation [GSD] of 3.2) and 3.2 microg/L per mg/m(3) (GSD=1.7), respectively. Chemical-specific blood concentration screening values based on non-cancer reference values for both oral and inhalation exposure range from 0.0005 to 100 microg/L; blood concentrations associated with cancer risk-specific doses at the 1E-05 risk level ranged from 5E-06 to 6E-02 microg/L. The distribution of modeled steady-state blood concentrations associated with unit exposure levels across VOCs may provide a basis for estimating blood concentration screening values for VOCs that lack chemical-specific pharmacokinetic data. The screening blood concentrations presented here provide a tool for risk assessment-based evaluation of population biomonitoring data for VOCs and are most appropriately applied to central tendency estimates for such datasets. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Long-range transport of Xe-133 emissions under convective and non-convective conditions.

PubMed

Kuśmierczyk-Michulec, J; Krysta, M; Kalinowski, M; Hoffmann, E; Baré, J

2017-09-01

To investigate the transport of xenon emissions, the Provisional Technical Secretariat (PTS) operates an Atmospheric Transport Modelling (ATM) system based on the Lagrangian Particle Dispersion Model FLEXPART. The air mass trajectory ideally provides a "link" between a radionuclide release and a detection confirmed by radionuclide measurements. This paper investigates the long-range transport of Xe-133 emissions under convective and non-convective conditions, with special emphasis on evaluating the changes in the simulated activity concentration values due to the inclusion of the convective transport in the ATM simulations. For that purpose a series of 14 day forward simulations, with and without convective transport, released daily in the period from 1 January 2011 to 30 June 2013, were analysed. The release point was at the ANSTO facility in Australia. The simulated activity concentrations for the period January 2011 to February 2012 were calculated using the daily emission values provided by the ANSTO facility; outside the aforementioned period, the median daily emission value was used. In the simulations the analysed meteorological input data provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) were used with the spatial resolution of 0.5°. It was found that the long-range transport of Xe-133 emissions under convective conditions, where convection was included in the ATM simulation, led to a small decrease in the activity concentration, as compared to transport without convection. In special cases related to deep convection, the opposite effect was observed. Availability of both daily emission values and measured Xe-133 activity concentration values was an opportunity to validate the simulations. Based on the paired t-test, a 95% confidence interval for the true mean difference between simulations without convective transport and measurements was constructed. It was estimated that the overall uncertainty lies between 0.08 and 0.25 mBq/m 3 . The uncertainty for the simulations with the convective transport included is slighted shifted to the lower values and is in the range between 0.06 and 0.20 mBq/m 3 . Copyright © 2017. Published by Elsevier Ltd.

Serum transferrin receptor status of healthy adult Arabs.

PubMed

Knox-Macaulay, Huxley; Gravell, David; Elender, Frances

2007-01-01

Several studies have provided reference ranges for the concentration of serum transferrin receptor (sTfR) in various white populations, but there is a dearth of relevant reference sTfR data in non-whites. The aim of this investigation was to establish sTfR reference ranges and mean values for a healthy non-white Arab population that could be used also for Arabs worldwide. sTfR and serum ferritin concentrations were estimated by immunoassays and blood counts were determined by conventional methods. Analysis of the data of 114 volunteer Arab blood donors (91 male, 23 female) revealed a higher mean sTfR concentration in males of 22.6+/-8.1 nmol/L (range 10.9-38.7 nmol/L) compared to that in females of 18.7+/-4.4 nmol/L (range 10.7-25.8 nmol/L, p=0.001). There was no significant correlation of sTfR concentration with age, serum ferritin level, or blood haemoglobin level, but a strong inverse correlation was demonstrated with mean cell volume and mean cell haemoglobin of red cells. Iron-replete volunteer subjects with alpha-thalassaemia trait appear to have relatively high mean sTfR concentration. We recommend the use of gender-dependent sTfR reference values for Arabs.

Size distribution of radon daughter particles in uranium mine atmospheres.

PubMed

George, A C; Hinchliffe, L; Sladowski, R

1975-06-01

The size distribution of radon daughters was measured in several uranium mines using four compact diffusion batteries and a round jet cascade impactor. Simultaneously, measurements were made of uncombined fractions of radon daughters, radon concentration, working level and particle concentration. The size distributions found for radon daughters were log normal. The activity median diameters ranged from 0.09 mum to 0.3 mum with a mean value of 0.17 mum. Geometric standard deviations were in the range from 1.3 to 4 with a mean value of 2.7. Uncombined fractions expressed in accordance with the ICRP definition ranged from 0.004 to 0.16 with a mean value of 0.04. The radon daughter sizes in these mines are greater than the sizes assumed by various authors in calculating respiratory tract dose. The disparity may reflect the widening use of diesel-powered equipment in large uranium mines.

The Role of Hydrous Slab Melts in the Sulfur Content, Metal Content, and Oxidation State of Primitive Arc Magmas in the Southern Cascades

NASA Astrophysics Data System (ADS)

Muth, M.; Wallace, P. J.; Walowski, K. J.

2017-12-01

Arc magmas have an oxidized signature (higher Fe3+/∑Fe) relative to MORB. This oxidized signature could be developed during crustal differentiation or be derived from slab components such as hydrous melts and ­fluids. Previous work in the Lassen region of the Cascade arc shows evidence for the addition of a hydrous slab component to the mantle wedge beneath the southern Cascades [1]. Here we investigate whether this hydrous slab component is linked to the oxidation state of primitive magmas using the sulfur, metal, and trace element concentrations of olivine-hosted melt inclusions. Melt inclusions were selected from the tephra of three cinder cones in Lassen volcanic field and analyzed for trace elements and metals (Cu, Zn, Sn) using LA-ICPMS and for major elements, S, and Cl using EMPA. Sulfur concentrations in individual melt inclusions range from 900 to 2200 ppm. Cu, Zn, and Sn concentrations in individual melt inclusions range from 17 to 167 ppm, 65 to 127 ppm, and 0.4 to 1.4 ppm, respectively. Average sulfur concentrations are different for each of the three cinder cones, and individual melt inclusion S/Dy values correlate well with Sr/Nd values. This is an indication that, like other volatiles, sulfur is supplied to the mantle wedge by a slab-derived component. To assess whether this sulfur-carrying slab component affects the oxidation state of the mantle wedge during melting, we used estimates of sulfur content at sulfide saturation to place a minimum bound on fO2 values for the primitive magmas at each cinder cone. These values range from QFM to QFM + 1.5. Despite this wide range of fO2 values, the concentrations of Cu and other metals are low relative to values predicted by partial melting of the mantle wedge during relatively oxidized (greater than QFM + 1.3) conditions [2], and do not vary systematically with indicators of slab component addition such as Sr/Nd. This suggests that metals are not derived from the slab component and/or that residual sulfide is present during melting across the wide range of fO2 values. This observation is also consistent with the addition of a sulfur-carrying slab component to the mantle wedge. Future work will compare these observations to direct measurement of Fe3+/∑Fe and S6+/∑S using XANES. [1] Walowski et al. 2016, EPSL. [2] Lee et al. 2012, Science.

Biological activities of extracts from cultivated Granadilla Passiflora alata.

PubMed

Vasic, Sava M; Stefanovic, Olgica D; Licina, Braho Z; Radojevic, Ivana D; Comic, Ljiljana R

2012-01-01

Research conducted in this study showed the influence of ethanol, acetone and ethyl acetate extracts of the outgrowth of cultivated Passiflora alata on microorganisms, as well as the antioxidant activity and the concentrations of total phenols, flavonoids and tannins. In vitro antimicrobial activities of extracts were studied on 27 species of microorganisms, of which 17 species of bacteria and 10 species of fungi. The strongest antimicrobial activity was detected on G+ bacteria while the activities on other species were moderate. Ethyl acetate extract showed the strongest effect. The concentrations of total phenols were examined by using Folin-Ciocalteu reagent and the obtained values ranged from 14.04 to 34.22 mg GA/g. By using aluminium chloride method, the concentrations of flavonoids were obtained and the values ranged from 33.19 to 62.30 mg RU/g. In determining the amount of tannins we used the method with buthanol-HCl reagent and the obtained value was 5.1 % of dry matter. The efficiency of antioxidation, which we identified through the reduction of DPPH, was in the range from 808.69 to 1107.79 µg/ml for a particular IC50, and AAI values were between 0.07 and 0.10. The best parameters were shown by ethanol extract. All data were statistically analyzed. Overall, extracts showed potential for further investigation and use.

Measurement of oxytetracycline and emamectin benzoate in freshwater sediments downstream of land based aquaculture facilities in the Atlantic Region of Canada.

PubMed

Lalonde, Benoit A; Ernst, William; Greenwood, Lyndsay

2012-09-01

This study investigated the occurrence of oxytetracycline (OTC) and emamectin benzoate (EB) in sediments located near the effluent outfall from four freshwater aquaculture facilities in Atlantic Canada. While two facilities had no detectable concentrations of EB or OTC, two facilities had detectable concentrations of one or both of these chemicals. Concentrations ranged from <0.05-18 mg/kg to <0.01-2.5 mg/kg for OTC and EB respectively. Although these values could not be compared with freshwater toxicant values, some of the concentrations of EB and OTC detected were higher than LC(50) values calculated for marine invertebrates. OTC concentrations measured in this study are also of a magnitude which has been known to produce resistant bacteria.

Water quality of Calero Reservoir, Santa Clara County, California, 1981-83

USGS Publications Warehouse

Clifton, D.G.; Gloege, I.S.

1987-01-01

Data were collected from December 1980 to September 1983 to describe water quality conditions of Calero Reservoir and the Almaden-Calero canal, Santa Clara County, California. Results show that water in Calero Reservoir and the canal generally met water quality criteria, as identified by the California Regional Water Quality Control Board San Francisco Bay Region, for municipal and domestic supply, water contact and non-contact recreation, warm water fish habitat, wildlife habitat, and fish spawning. Water temperature profiles show that Calero Reservoir can be classified as a warm monomictic reservoir. Water transparency profiles showed rapid attenuation of light with depth in the water column. The depth of the euphotic zone ranged from .5 m to 5.0 m. In winter and spring, light-extinction values generally were high throughout the water column; in summer and fall, values generally were high near the reservoir bottom. Dissolved oxygen concentrations were < 5.0 mg/L in about 22% of the measurements. Median pH values were 7.9 in the reservoir and 8.4 in the canal. Mean specific conductance values were 299 microsiemens/cm at 25 C in the reservoir and 326 in the canal. Calcium and magnesium were the dominant cations and bicarbonate the dominant anion in Calero Reservoir. Concentrations of total recoverable mercury in the bottom sediments in Calero Reservoir ranged from 0.06 to 0.85 mg/kg, but concentrations in the water column were was generally < 1 mg/L. Mean total nitrogen concentration in the Reservoir was 1.00 mg/L, much of it in dissolved form (mean concentration was 0.85 mg/L). Mean total organic nitrogen concentration in Calero Reservoir was 0.65 mg/L, and mean total nitrate concentration was 0.21 mg/L. Mean total phosphorus and dissolved orthophosphorous concentrations were 0.05 and 0.019 mg/L, respectively. Net primary productivity in the euphotic zone ranged from -2,000 to 10,000 mg of oxygen/sq m/day; the median value was 930. Carlson 's trophic-state index, calculated using water transparency, total phosphorus, and chlorophyll-a values, indicated that the reservoir was eutrophic. Fecal coliform bacteria concentrations were < 20 colonies/100 ml in the reservoir and < 200 colonies/100 ml in the canal. Fecal streptococcal bacteria concentrations were generally < 45 colonies/100 ml in the reservoir and up to 260 colonies/100 ml in the canal. (Author 's abstract)

Surface-water-quality assessment of the Upper Illinois River basin in Illinois, Indiana, and Wisconsin; cross-sectional and depth variation of water-quality constituents and properties in the Upper Illinois River basin, 1987-88

USGS Publications Warehouse

Marron, Donna C.; Blanchard, Stephen F.

1995-01-01

Data on water velocity, temperature, specific con- ductance, pH, dissolved oxygen concentration, chlorophyll concentration, suspended sediment con- centration, fecal-coliform counts, and the percen- tage of suspended sediment finer than 62 micrometers ranged up to 21 percent; and cross-section coefficients of variation of the concentrations of suspended sediment, fecal coliform, and chlorophyll ranged from 7 to 115 percent. Midchannel measure- ments of temperature, specific conductance, and pH were within 5 percent of mean cross-sectional values of these properties at the eight sampling sites, most of which appear well mixed because of the effect of dams and reservoirs. Measurements of the concentration of dissolved oxygen at various cross- section locations and at variable sampling depths are required to obtain a representative value of this constituent at these sites. The large varia- bility of concentrations of chlorophyll and suspended sediment, and fecal-coliform counts at the eight sampling sites indicates that composite rather than midchannel or mean values of these constituents are likely to be most representative of the channel cross section.

Industrial garnet

USGS Publications Warehouse

Olson, D.W.

2006-01-01

In 2005, US production of crude garnet concentrate for industrial use was 28.4 kt valued at $3.05 million. Refined garnet material sold or used was 30.4 kt valued at $10 million. For the year, the US was one of the world's leading consumers of industrial garnet. Domestic values for crude concentrates for different applications ranged from about $53 to $120/t. In the short term, excess production capacity, combined with suppliers that vary in quality, grain size and mineral type, will keep prices down.

SOLVENT EXTRACTION OF THORIUM VALUES FROM AQUEOUS SOLUTIONS

DOEpatents

Warf, J.C.

1959-04-21

The separation of thorium values from rare earth metals contained ln aqueous solutions by means of extraction with a water immiscible alkyl phosphate diluted with a hydrocarbon such as hexane is described. While the extraction according to this invention may be carried out from any aqueous salt solution, it is preferred to use solutions containing free mineral acid. Hydrochloric acid and in particular nitric acid are sultable in a concentration ranging from 0.1 to 7 normal. The higher acid concentration results in higher extraction values.

Environmental geochemical study of Red Mountain--an undisturbed volcanogenic massive sulfide deposit in the Bonnifield District, Alaska range, east-central Alaska: Chapter I in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

USGS Publications Warehouse

Eppinger, Robert G.; Briggs, Paul H.; Dusel-Bacon, Cynthia; Giles, Stuart A.; Gough, Larry P.; Hammarstrom, Jane M.; Hubbard, Bernard E.

2007-01-01

Water samples with the lowest pH values, highest specific conductances, and highest major- and trace-element concentrations are from springs and streams within the quartz-sericite-pyrite alteration zone. Aluminum, As, Cd, Co, Cu, Fe, Mn, Ni, Pb, Y, and particularly Zn and the REEs are all found in high concentrations, ranging across four orders of magnitude. Waters collected upstream from the alteration zone have near-neutral pH values, lower specific conductances, lower metal concentrations, and measurable alkalinities. Water samples collected downstream of the alteration zone have pH values and metal concentrations intermediate between these two extremes. Stream sediments are anomalous in Zn, Pb, S, Fe, Cu, As, Co, Sb, and Cd relative to local and regional background abundances. Red Mountain Creek and its tributaries do not support, and probably never have supported, significant megascopic faunal aquatic life.

Rapid determination of surfactant critical micelle concentration in aqueous solutions using fiber-optic refractive index sensing.

PubMed

Tan, Chun Hua; Huang, Zhen Jian; Huang, Xu Guang

2010-06-01

We describe a simple and rapid method for determining the critical micelle concentration (CMC) of surfactants from fiber-optic measurements of refractive index. The refractive index of an aqueous surfactant solution was monitored as the surfactant concentration was increased using an automated dispensing system. On reaching the surfactant's CMC value, an abrupt change was observed in the rate of increase of the refractive index with increasing concentration. The measurement system provides rapid semiautomatic data collection and analysis, increasing the precision, sensitivity, and range of applicability of the technique while substantially decreasing the amount of manual intervention required. Measurements of CMC for sodium dodecyl sulfate (8.10mM), cetyltrimethylammonium chloride (1.58mM), and Triton X-100 (0.21mM) were in excellent agreement with values previously reported in the literature. The method is applicable to cationic, anionic, and nonionic surfactants, and it offers a facile, in situ, and sensitive means of detecting micelle formation over a broad range of CMC values larger than 10(-1)mM. Copyright 2010 Elsevier Inc. All rights reserved.

Determination of uptake kinetics (sampling rates) by lipid-containing semipermeable membrane devices (SPMDs) for polycyclic aromatic hydrocarbons (PAHs) in water

USGS Publications Warehouse

Huckins, J.N.; Petty, J.D.; Orazio, C.E.; Lebo, J.A.; Clark, R.C.; Gibson, V.L.; Gala, W.R.; Echols, K.R.

1999-01-01

The use of lipid-containing semipermeable membrane devices (SPMDs) is becoming commonplace, but very little sampling rate data are available for the estimation of ambient contaminant concentrations from analyte levels in exposed SPMDs. We determined the aqueous sampling rates (R(s)s; expressed as effective volumes of water extracted daily) of the standard (commercially available design) 1-g triolein SPMD for 15 of the priority pollutant (PP) polycyclic aromatic hydrocarbons (PAHs) at multiple temperatures and concentrations. Under the experimental conditions of this study, recovery- corrected R(s) values for PP PAHs ranged from ???1.0 to 8.0 L/d. These values would be expected to be influenced by significant changes (relative to this study) in water temperature, degree of biofouling, and current velocity- turbulence. Included in this paper is a discussion of the effects of temperature and octanol-water partition coefficient (K(ow)); the impacts of biofouling and hydrodynamics are reported separately. Overall, SPMDs responded proportionally to aqueous PAH concentrations; i.e., SPMD R(s) values and SPMD-water concentration factors were independent of aqueous concentrations. Temperature effects (10, 18, and 26 ??C) on Rs values appeared to be complex but were relatively small.The use of lipid-containing semipermeable membrane devices (SPMDs) is becoming commonplace, but very little sampling rate data are available for the estimation of ambient contaminant concentrations from analyte levels in exposed SPMDs. We determined the aqueous sampling rates (Rss; expressed as effective volumes of water extracted daily) of the standard (commercially available design) 1-g triolein SPMD for 15 of the priority pollutant (PP) polycyclic aromatic hydrocarbons (PAHs) at multiple temperatures and concentrations. Under the experimental conditions of this study, recovery-corrected Rs values for PP PAHs ranged from ???1.0 to 8.0 L/d. These values would be expected to be influenced by significant changes (relative to this study) in water temperature, degree of biofouling, and current velocity-turbulence. Included in this paper is a discussion of the effects of temperature and octanol-water partition coefficient (KOW); the impacts of biofouling and hydrodynamics are reported separately. Overall, SPMDs responded proportionally to aqueous PAH concentrations; i.e., SPMD RS values and SPMD-water concentration factors were independent of aqueous concentrations. Temperature effects (10, 18, and 26??C) on RS values appeared to be complex but were relatively small.

Measurements of radioactivity and dose assessments in some building materials in Bitlis, Turkey.

PubMed

Kayakökü, Halime; Karatepe, Şule; Doğru, Mahmut

2016-09-01

In this study, samples of perlite, pumice and Ahlat stones (Ignimbrite) extracted from mines in Bitlis and samples of other building materials produced in facilities in Bitlis were collected and analyzed. Activity concentrations of (226)Ra, (232)Th and (40)K in samples of building materials were measured using NaI detector (NaI(Tl)) with an efficiency of 24%. The radon measurements of building material samples were determined using CR-39 nuclear track detectors. (226)Ra, (232)Th and (40)K radioactivity concentrations ranged from (29.6±5.9 to 228.2±38.1Bq/kg), (10.8±5.4 to 95.5±26.1Bq/kg) and (249.3±124.7 to 2580.1±266.9Bq/kg), respectively. Radon concentration, radium equivalent activities, absorbed dose rate, excess lifetime cancer risk and the values of hazard indices were calculated for the measured samples to assess the radiation hazards arising from using those materials in the construction of dwellings. Radon concentration ranged between 89.2±12.0Bq/m(3) and 1141.0±225.0Bq/m(3). It was determined that Raeq values of samples conformed to world standards except for perlite and single samples of brick and Ahlat stone. Calculated values of absorbed dose rate ranged from 81.3±20.5 to 420.6±42.8nGy/h. ELCR values ranged from (1.8±0.3)×10(-3) to (9.0±1.0)×10(-3). All samples had ELCR values higher than the world average. The values of Hin and Hex varied from 0.35±0.11 to 1.78±0.18 and from 0.37±0.09 to 1.17±0.13, respectively. The results were compared with standard radioactivity values determined by international organizations and with similar studies. There would be a radiation risk for people living in buildings made of perlite, Ahlat-1 and Brick-3. Copyright © 2016 Elsevier Ltd. All rights reserved.

Osmotic potential calculations of inorganic and organic aqueous solutions over wide solute concentration levels and temperatures.

PubMed

Cochrane, T T; Cochrane, T A

2016-01-01

To demonstrate that the authors' new "aqueous solution vs pure water" equation to calculate osmotic potential may be used to calculate the osmotic potentials of inorganic and organic aqueous solutions over wide ranges of solute concentrations and temperatures. Currently, the osmotic potentials of solutions used for medical purposes are calculated from equations based on the thermodynamics of the gas laws which are only accurate at low temperature and solute concentration levels. Some solutions used in medicine may need their osmotic potentials calculated more accurately to take into account solute concentrations and temperatures. The authors experimented with their new equation for calculating the osmotic potentials of inorganic and organic aqueous solutions up to and beyond body temperatures by adjusting three of its factors; (a) the volume property of pure water, (b) the number of "free" water molecules per unit volume of solution, "Nf," and (c) the "t" factor expressing the cooperative structural relaxation time of pure water at given temperatures. Adequate information on the volume property of pure water at different temperatures is available in the literature. However, as little information on the relative densities of inorganic and organic solutions, respectively, at varying temperatures needed to calculate Nf was available, provisional equations were formulated to approximate values. Those values together with tentative t values for different temperatures chosen from values calculated by different workers were substituted into the authors' equation to demonstrate how osmotic potentials could be estimated over temperatures up to and beyond bodily temperatures. The provisional equations formulated to calculate Nf, the number of free water molecules per unit volume of inorganic and organic solute solutions, respectively, over wide concentration ranges compared well with the calculations of Nf using recorded relative density data at 20 °C. They were subsequently used to estimate Nf values at temperatures up to and excess of body temperatures. Those values, together with t values at temperatures up to and in excess of body temperatures recorded in the literature, were substituted in the authors' equation for the provisional calculation of osmotic potentials. The calculations indicated that solution temperatures and solute concentrations have a marked effect on osmotic potentials. Following work to measure the relative densities of aqueous solutions for the calculation of Nf values and the determination of definitive t values up to and beyond bodily temperatures, the authors' equation would enable the accurate estimations of the osmotic potentials of wide concentrations of aqueous solutions of inorganic and organic solutes over the temperature range. The study illustrates that not only solute concentrations but also temperatures have a marked effect on osmotic potentials, an observation of medical and biological significance.

40 CFR 86.125-94 - Methane analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Additional calibration points may be generated. For each range calibrated, if the deviation from a least-squares best-fit straight line is 2 percent or less of the value at each data point, concentration values...

40 CFR 86.125-94 - Methane analyzer calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Additional calibration points may be generated. For each range calibrated, if the deviation from a least-squares best-fit straight line is 2 percent or less of the value at each data point, concentration values...

40 CFR 86.125-94 - Methane analyzer calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Additional calibration points may be generated. For each range calibrated, if the deviation from a least-squares best-fit straight line is 2 percent or less of the value at each data point, concentration values...

Assessing the link between chlorophyll concentration and absorption line height at 676 nm over a broad range of water types.

PubMed

Nardelli, Schuyler C; Twardowski, Michael S

2016-10-31

The relationship between absorption at 676 nm normalized to chlorophyll-a, i.e., specific absorption aph*(676), and various optical and environmental properties is examined in extensive data sets from Case I and Case II waters found globally to assess drivers of variability such as pigment packaging. A better understanding of this variability could lead to more accurate estimates of chlorophyll concentrations from in situ optical measurements that may be made autonomously. Values of aph*(676) ranged from 0.00006 to 0.0944 m²/mg Chl a across all sites studied, but converged on median and mean values (n = 563) of 0.0108 and 0.0139 m²/mg Chl a respectively, with no apparent relationship with various optical properties, latitude, coastal or open ocean environment, depth, temperature, salinity, photoadaptation, ecosystem health, or albedo. Relative consistency in aph* across such diverse water types and the full range in chlorophyll concentration suggests a single aph* may be used to estimate chlorophyll concentration from absorption measurements with better accuracy than currently thought.

Correlation between mercury and selenium concentrations in Indian hair from Rondĵnia State, Amazon region, Brazil.

PubMed

Soares, Mônica Campos; Sarkis, Jorge Eduardo Souza; Müller, Regina Céli Sarkis; Brabo, Edilson Silva; Santos, Elizabete Oliveira

2002-03-15

Total mercury and selenium concentrations were determined in hair samples collected from Wari (Pacaás Novos) Indians living in Doutor Tanajura village, Gujará-Mirim city, Rondĵnia State. The mercury concentrations in some samples are much higher than the values determined in samples from individuals not exposed to mercury contamination, occupationally or environmentally. The selenium concentrations are in the normal range. A correlation was observed between the mercury and selenium concentration and the values of the molar ratio approach 1 at low Hg concentrations. This fact is related to the equimolar complex formed by [(Hg-Se)n]m-Seleprotein P, which can decrease the bioavailable mercury in the organism.

Radium and uranium concentrations and associated hydrogeochemistry in ground water in southwestern Pueblo County, Colorado

USGS Publications Warehouse

Felmlee, J. Karen; Cadigan, Robert Allen

1979-01-01

Radium and uranium concentrations in water from 37 wells tapping the aquifer system of the Dakota Sandstone and Purgatoire Formation in southwestern Pueblo County, Colorado, have a wide range of values and define several areas of high radioactivity in the ground water. Radium ranges from 0.3 to 420 picocuries per liter and has a median value of 8.8, and uranium ranges from 0.02 to 180 micrograms per liter and has a median value of 2.4. Radon concentrations, measured in 32 of the 37 wells, range from less than 100 picocuries per liter to as much as 27,000 and have a median value of 580. Relationships among the radioactive elements and 28 other geochemical parameters were studied by using correlation coefficients and R-mode factor analysis. Five factor groups were determined to represent major influences on water chemistry: (1) short-term solution reactions, (2) oxidation reactions, (3) hydrolysis reactions, (4) uranium distribution, and (5) long-term solution reactions. Uranium concentrations are most strongly influenced by oxidation reactions but also are affected by solution reactions and distribution of uranium in the rocks of the aquifer system. Radon and radium concentrations are mostly controlled by uranium distribution; radium also shows a moderate negative relationship with oxidation. To explain the statistical and spatial relationships among the parameters, a model was developed involving the selective leaching of uranium-bearing phases and metal sulfides which occur in discontinuous zones in sandstone and shale. When reducing conditions prevail, uranium is immobile, but radium can be taken into solution. When faults and associated fractured rocks allow oxidizing conditions to dominate, uranium can be taken into solution; radium can also be taken into solution, or it may become immobilized by coprecipitation with iron and manganese oxides or with barite. Several areas within the study area are discussed in terms of the model.

Using geochemical and isotopic techniques for exploration of geothermal energy in Southern Sabalan geothermal field, NW Iran

NASA Astrophysics Data System (ADS)

Masoumi, Rahim

2017-04-01

From a hydrogeochemical point of view the geothermal fluids in the study area can be divided into two categories, (1) Na-Cl and (2) Na-Ca-HCO3. In the study area, the hot water samples depict temperature and pH ranges of 22 °C to 77 °C and 6.4 to 7.3, respectively. The total dissolved solids vary from 456 mg/L to 7006 mg/L. The concentration of rare metallic and non-metallic elements such as Li, Rb, B, Ba, Sr, CS, Se, Al, As, Hg in cold and hot spring waters in the Bushdi area were also analyzed. The utmost concentration belongs to Se which ranges from 135 mg/L to 273 mg/L. Boron also shows notable concentration values, in most samples it exceeds 20 mg/L, and in certain samples it ranges from 28 mg/L to 33.5 mg/L. The concentration value of arsenic ranges from 3 mg/L to 4 mg/L. The maximum concentration value of mercury is 0.01 mg/L. The δ18O values of these samples vary from -12.4 ‰ to -7.5 ‰ and the δD values range from -78.6 ‰ to -70.6 ‰. Plotting δ18O versus δD demonstrates that the data points are clustered close to both, the global meteoric water line (GMWL) with the equation δD = 8 δ18O + 10 and, the national meteoric water line (NMWL) with the equation δD = 6.89 δ18O + 6.57. As can be observed, the geothermal fluids in the Bushdi area show relatively slight increase in δ18O values that may be caused by interaction of hot fluids with host volcanic rocks. In fact, this relatively slight increment in δ18O values may indicate the low to moderate temperature of the geothermal system. The δD values, in general, do not show notable variation because of very low hydrogen content of the host rocks. The slight increase in δD, however, may be in conjunction with vaporization and isotopic interaction with the host rocks. The 3H content of the cold and hot waters in the Bushdi area is relatively high and varies from 0.65 TU to 41.4 TU. This may be caused either by mixing with meteoric sources or rapid fluid flow within the system in a shorter time than the β- disintegration of the isotope 3H. The δ18O versus δD diagram demonstrates that the data for the Bushdi area is plotted in three distinct domains, a, b, c. In a, the 3H content is > 10 TU indicating these waters being modern waters. Domain b belongs to samples whose 3H values are within the range of 1 TU to 10 TU being temporally categorized as sub-modern waters. The water samples in c possess 3H values < 1 TU indicating the oldest waters within the geothermal system in the study area. Key words: Geothermal fluids, Stable isotopes, Tracemetals, Sabalan volcano.

Indoor radon activity concentration measurements in the great historical museums of University of Naples, Italy.

PubMed

Quarto, Maria; Pugliese, Mariagabriella; Loffredo, Filomena; La Verde, Giuseppe; Roca, Vincenzo

2016-01-01

Indoor radon activity concentrations were measured in seven Museums of University of Naples, very old buildings of great historical value. The measurements were performed using a time-integrated technique based on LR-115 solid-state nuclear track detectors. The annual average concentrations were found to range from 40 up to 1935 Bq m(-3) and in 26 % of measurement sites, the values were higher than 500 Bq m(-3) which is the limit value of Italian legislation for workplace. Moreover, we analysed the seasonal variations of radon concentrations observing the highest average in cold weather than in warm. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of pH2O, pH2 and fO2 on the Diffusion of H-Bearing Species in Lunar Basalt and an Iron-Free Basaltic Analog at 1 atm

NASA Astrophysics Data System (ADS)

Newcombe, M. E.; Beckett, J. R.; Baker, M. B.; Newman, S.; Guan, Y.; Eiler, J. M.; Stolper, E. M.

2016-12-01

We have conducted water diffusion experiments in synthetic Apollo 15 "yellow glass" (LG) and an iron-free basaltic analog melt (AD) at 1 atm and 1350 °C over a range of fO2 conditions from IW-2.2 to IW+6.7 and over a range of pH2/pH2O from nominally zero to 10. The water concentrations measured in our quenched experimental glasses by SIMS and FTIR vary from a few ppm to 430 ppm. Many studies of water diffusion at higher water concentrations indicate that the apparent diffusivity of total water (D*water; see [1]) in silicate melts is highly concentration dependent at water contents >0.1 wt% (e.g., [1]). However, water concentration gradients in each of our AD and LG experiments are well described by models in which D*water is assumed to be constant. Best-fit values of D*water obtained for our AD and LG experiments are consistent with a modified speciation model [2] in which both molecular water and hydroxyl are allowed to diffuse, and in which hydroxyl is the dominant diffusing species at the low total water concentrations of our experiments. Water concentration gradients generated during hydration and dehydration experiments conducted simultaneously propagate approximately equal distances into the melt and have the same concentration of water dissolved in the melt at the melt-vapor interface, suggesting that hydration and dehydration are symmetric under the conditions of our experiments. Best-fit values of D*water for our LG experiments vary within a factor of 2 over a range of pH2/pH2O from 0.007 to 9.7 (a range of ƒO2 from IW-2.2 to IW+4.9) and a water concentration range from 80 ppm to 280 ppm. The relative insensitivity of D*water to variations in pH2 suggests that loss of H during the degassing of the lunar melts described by [3] was not primarily by loss of dissolved H2. The value of D*water chosen by [3] for modeling diffusive degassing of lunar volcanic glasses is within a factor of three of our measured value in LG melt at 1350 °C. [1] Zhang et al. (1991) GCA 55, 441-456; [2] Ni et al. (2013) GCA 103, 36-48; [3] Saal et al. (2008) Nature 454, 192-195.

Ground-water monitoring plan, water quality, and variability of agricultural chemicals in the Missouri River alluvial aquifer near the City of Independence, Missouri, well field, 1998-2000

USGS Publications Warehouse

Kelly, Brian P.

2002-01-01

A detailed ground-water sampling plan was developed and executed for 64 monitoring wells in the city of Independence well field to characterize ground-water quality in the 10-year zone of contribution. Samples were collected from monitoring wells, combined Independence well field pumpage, and the Missouri River at St. Joseph, Missouri, from 1998 through 2000. In 328 ground-water samples from the 64 monitoring wells and combined well field pumpage samples, specific conductance values ranged from 511 to 1,690 microsiemens per centimeter at 25 degrees Celsius, pH values ranged from 6.4 to 7.7, water temperature ranged from 11.3 to 23.6 degrees Celsius, and dissolved oxygen concentrations ranged from 0 to 3.3 milligrams per liter. In 12 samples from the combined well field pumpage samples, specific conductance values ranged from 558 to 856 microsiemens per centimeter at 25 degrees Celsius, pH values ranged from 6.9 to 7.7, water temperature ranged from 5.8 to 22.9 degrees Celsius, and dissolved oxygen concentrations ranged from 0 to 2.4 milligrams per liter. In 45 Missouri River samples, specific conductance values ranged from 531 to 830 microsiemens per centimeter at 25 degrees Celsius, pH ranged from 7.2 to 8.7, water temperature ranged from 0 to 30 degrees Celsius, and dissolved oxygen concentrations ranged from 5.0 to 17.6 milligrams per liter. The secondary maximum contaminant level for sulfate in drinking water was exceeded once in samples from two monitoring wells, the maximum contaminant level (MCL) for antimony was exceeded once in a sample from one monitoring well, and the MCL for barium was exceeded once in a sample from one monitoring well. The MCL for iron was exceeded in samples from all monitoring wells except two. The MCL for manganese was exceeded in all samples from monitoring wells and combined well field pumpage. Enzyme linked immunoassay methods indicate total benzene, toluene, ethyl benzene, and xylene (BTEX) was detected in samples from five wells. The highest total BTEX concentration was less than the MCL of toluene, ethyl benzene, or xylene but greater than the MCL for benzene. Total BTEX was not detected in samples from any well more than once. Atrazine was detected in samples from nine wells, and exceeded the MCL once in a sample from one well. Alachlor was detected in samples from 22 wells but the MCL was never exceeded in any sample. Samples from five wells analyzed for a large number of organic compounds indicate concentrations of volatile organic compounds did not exceed the MCL for drinking water. No semi-volatile organic compounds were detected; dieldrin was detected in one well sample, and no other pesticides, herbicides, polychlorinated biphenyls, or polychlorinated napthalenes were detected. Dissolved ammonia, dissolved nitrite plus nitrate, dissolved orthophosphorus, alachlor, and atrazine analyses were used to determine the spatial and temporal variability of agricultural chemicals in ground water. Detection frequencies for dissolved ammonia increased with well depth, decreased with depth for dissolved nitrite plus nitrate, and remained relatively constant with depth for dissolved orthophosphorus. Maximum concentrations of dissolved ammonia, dissolved nitrite plus nitrate, and dissolved orthophosphorus were largest in the shallowest wells and decreased with depth, which may indicate the land surface as the source. However, median concentrations increased with depth for dissolved ammonia, were less than the detection limit for dissolved nitrite plus nitrate, and decreased with depth for dissolved orthophosphorus. This pattern does not indicate a well-defined single source for these constituents. Dissolved orthophosphorus median concentrations were similar, but decreased slightly with depth, and may indicate the land surface as the source. Seasonal variability of dissolved ammonia, dissolved nitrite plus nitrate, a

Vitamin E in cranes: reference ranges and nutrient interactions

USGS Publications Warehouse

Dierenfeld, Ellen S.; Sheppard, C.D.; Langenberg, J.; Mirande, C.; Spratt, J.; Dein, F.J.

1993-01-01

Fat soluble vitamins E and A (quantified as alpha-tocopherol and all-trans retinol, respectively) were measured in plasma samples from 274 captive cranes from four institutions and five free-ranging birds. Ages ranged from 4 mo to 80 yr, and all 15 crane species were represented. Captive cranes had a mean +/- standard error (SE) of 6.57 +/- 0.82 micrograms/ml alpha-tocopherol; migrating greater sandhill cranes (Grus canadenis tabida) had a plasma concentration of 3.71 +/- 0.22 micrograms/ml. Sex and age differences were not significant, but crane species that evolved in temperate habitats had higher circulating levels of alpha-tocopherol than tropical or subtropical species. Mean +/- SE retinol values were 0.69 +/- 0.05 micrograms/ml in captive cranes, and 0.66 +/- 0.08 micrograms/ml in free-ranging cranes; values did not differ significantly by sex, age, or species. Dietary vitamin E concentrations were significantly correlated with plasma alpha-tocopherol levels in a logarithmic relationship. Dietary selenium at 0.5 mg/kg was associated with decreased circulating alpha-tocopherol concentrations.

[Mean values of blood pressure and endothelin plasma concentration in patients with chronic renal failure].

PubMed

Kocur, E; Kidawa, Z; Polakowski, P; Orszulak-Michalak, D; Karpinski, J; Rogulski, B; Wołkanin, P

1998-09-01

The aim of the present study was evaluation of correlation between big-endothelin concentration of the precursor substance of endothelin and mean values of blood pressure in 13 patients with compensates chronic renal failure. Their age ranged from 29 years to 55 years the mean age was 42.9 +/- 8.2 years. The patients were from the Consultational Nephrologic Outpatient Clinic. These patients were sent to the clinic after a hospital observation with recognised chronic renal failure (CRF), caused by chronic glomerulonephritis (without pathomorphological differentiation). The control group consistent of 10 healthy volunteers, an age ranged from 22 years to 49 years, a mean was 32.6 +/- 10.8 years. The following mean blood pressure values were found: in patient group a systolic pressure was 139.1 +/- 17.3 mm Hg and a diastolic pressure was 88.4 +/- 12.5 mm Hg and similar values in healthy control group were respectively: 118.6 +/- 4.0 and 72.4 +/- 5.9 mm Hg. Analogously the proendothelin concentration was 18.48 +/- 22.04 fmol/ml in patients with CRF and it was 4.67 +/- 0.27 fmol/ml in the control group. A positive correlation between mean blood systolic pressure values and the proendothelin concentration (r = 0.666, Y = 0.52X + 129.5; p < 0.05) in the was found patients group.

Wide range of mercury contamination in chicks of southern ocean seabirds.

PubMed

Blévin, Pierre; Carravieri, Alice; Jaeger, Audrey; Chastel, Olivier; Bustamante, Paco; Cherel, Yves

2013-01-01

Using top predators as sentinels of the marine environment, Hg contamination was investigated within the large subantarctic seabird community of Kerguelen Islands, a remote area from the poorly known Southern Indian Ocean. Chicks of 21 sympatric seabirds presented a wide range of Hg concentrations, with the highest contaminated species containing ~102 times more feather Hg than the less contaminated species. Hence, Kerguelen seabirds encompass the whole range of chick feather Hg values that were previously collected worldwide in poorly industrialized localities. Using stable isotopes, the effects of foraging habitats (reflected by δ(13)C) and trophic positions (reflected by δ(15)N) on Hg concentrations were investigated. Species-related Hg variations were highly and positively linked to feather δ(15)N values, thus highlighting the occurrence of efficient Hg biomagnification processes within subantarctic marine trophic webs. By contrast, Hg contamination overall correlated poorly with feeding habitats, because of the pooling of species foraging within different isotopic gradients corresponding to distinct seabird habitats (benthic, pelagic, neritic and oceanic). However, when focusing on oceanic seabirds, Hg concentration was related to feather δ(13)C values, with species feeding in colder waters (lower δ(13)C values) south of Kerguelen Islands being less prone to be contaminated than species feeding in northern warmer waters (higher δ(13)C values). Within the context of continuous increase in global Hg emissions, Kerguelen Islands that are located far away from anthropogenic sources can be considered as an ideal study site to monitor the temporal trend of global Hg contamination. The present work helps selecting some seabird species as sentinels of environmental pollution according to their high Hg concentrations and their contrasted foraging ecology.

Wide Range of Mercury Contamination in Chicks of Southern Ocean Seabirds

PubMed Central

Blévin, Pierre; Carravieri, Alice; Jaeger, Audrey; Chastel, Olivier; Bustamante, Paco; Cherel, Yves

2013-01-01

Using top predators as sentinels of the marine environment, Hg contamination was investigated within the large subantarctic seabird community of Kerguelen Islands, a remote area from the poorly known Southern Indian Ocean. Chicks of 21 sympatric seabirds presented a wide range of Hg concentrations, with the highest contaminated species containing ∼102 times more feather Hg than the less contaminated species. Hence, Kerguelen seabirds encompass the whole range of chick feather Hg values that were previously collected worldwide in poorly industrialized localities. Using stable isotopes, the effects of foraging habitats (reflected by δ13C) and trophic positions (reflected by δ15N) on Hg concentrations were investigated. Species-related Hg variations were highly and positively linked to feather δ15N values, thus highlighting the occurrence of efficient Hg biomagnification processes within subantarctic marine trophic webs. By contrast, Hg contamination overall correlated poorly with feeding habitats, because of the pooling of species foraging within different isotopic gradients corresponding to distinct seabird habitats (benthic, pelagic, neritic and oceanic). However, when focusing on oceanic seabirds, Hg concentration was related to feather δ13C values, with species feeding in colder waters (lower δ13C values) south of Kerguelen Islands being less prone to be contaminated than species feeding in northern warmer waters (higher δ13C values). Within the context of continuous increase in global Hg emissions, Kerguelen Islands that are located far away from anthropogenic sources can be considered as an ideal study site to monitor the temporal trend of global Hg contamination. The present work helps selecting some seabird species as sentinels of environmental pollution according to their high Hg concentrations and their contrasted foraging ecology. PMID:23349912

Anisotropy Changes of a Fluorescent Probe during the Micellar Growth and Clouding of a Nonionic Detergent.

PubMed

Komaromy-Hiller; von Wandruszka R

1996-01-15

The effects of temperature and Triton X-114 (TX-114) concentration on the fluorescence anisotropy of perylene were investigated before and after detergent clouding. The measured anisotropy values were used to estimate the microviscosity of the micellar interior. In the lower detergent concentration range, an anisotropy maximum was observed at the critical micelle concentration (CMC), while the values decreased in the range immediately above the CMC. This was ascribed to the micellar volume increase, which, in the case of TX-114, was not accompanied by a more ordered internal environment. A gradual decrease of anisotropy and microviscosity with increasing temperature below the cloud point was observed. At the cloud point, no abrupt changes were found to occur. Compared to detergents with more flexible hydrophobic moieties, TX-114 micelles have a relatively ordered micellar interior indicated by the microviscosity and calculated fusion energy values. In the separated micellar phase formed after clouding, the probe anisotropy increased as water was eliminated at higher temperatures.

[Distribution, flux and biological consumption of carbon monoxide in the East China Sea and the South Yellow Sea in summer].

PubMed

Wang, Jing; Lu, Xiao-Lan; Yang, Gui-Peng; Xu, Guan-Qiu

2014-11-01

Carbon monoxide (CO) concentration distribution, sea-to-air flux and microbial consumption rate constant, along with atmospheric CO mixing ratio, were measured in the East China Sea and the South Yellow Sea in summer. Atmospheric CO mixing ratios varied from 68 x 10(-9) -448 x 10(-9), with an average of 117 x 10(-9) (SD = 68 x 10(-9), n = 36). Overall, the concentrations of atmospheric CO displayed a decreasing trend from the coastal stations to the offshore stations. The surface water CO concentrations in the investigated area ranged from 0.23-7.10 nmol x L(-1), with an average of 2.49 nmol x L(-1) (SD = 2.11, n = 36). The surface water CO concentrations were significantly affected by sunlight. Vertical profiles showed that CO concentrations rapidly declined with depth, with the maximum values appearing in the surface water. CO concentrations exhibited obvious diurnal variations in the study area, with the maximum values being 6-40 folds higher than the minimum values. Minimal concentrations of CO all occurred before dawn. However, the maximal concentrations of CO occurred at noon. Marked diurnal variation in the concentrations of CO in the water column indicated that CO was produced primarily by photochemistry. The surface CO concentrations were oversaturated relative to the atmospheric concentrations and the saturation factors ranged from 1.99-99.18, with an average of 29.36 (SD = 24.42, n = 29). The East China Sea and the South Yellow Sea was a net source of atmospheric CO. The sea-to-air fluxes of CO in the East China Sea and the South Yellow Sea ranged 0.37-44.84 μmol x (m2 x d)(-1), with an average of 12.73 μmol x (m2 x d)(-1) (SD = 11.40, n = 29). In the incubation experiments, CO concentrations decreased exponentially with incubation time and the processes conformed to the first order reaction characteristics. The microbial CO consumption rate constants (K(co)) in the surface water ranged from 0.12 to 1.45 h(-1), with an average of 0.47 h(-1) (SD = 0.55, n = 5). A negative correlation between K(co) and salinity was observed in the present study.

Seasonality of diel cycles of dissolved trace-metal concentrations in a Rocky Mountain stream

USGS Publications Warehouse

Nimick, D.A.; Cleasby, T.E.; McCleskey, R. Blaine

2005-01-01

Substantial diel (24-h) cycles in dissolved (0.1-??m filtration) metal concentrations were observed during summer low flow, winter low flow, and snowmelt runoff in Prickly Pear Creek, Montana. During seven diel sampling episodes lasting 34-61.5 h, dissolved Mn and Zn concentrations increased from afternoon minimum values to maximum values shortly after sunrise. Dissolved As concentrations exhibited the inverse timing. The magnitude of diel concentration increases varied in the range 17-152% for Mn and 70-500% for Zn. Diel increases of As concentrations (17-55%) were less variable. The timing of minimum and maximum values of diel streamflow cycles was inconsistent among sampling episodes and had little relation to the timing of metal concentration cycles, suggesting that geochemical rather than hydrological processes are the primary control of diel metal cycles. Diel cycles of dissolved metal concentrations should be assumed to occur at any time of year in any stream with dissolved metals and neutral to alkaline pH. ?? Springer-Verlag 2005.

Uranium, Thorium and some other trace elements in phosphorites from different provenances

NASA Astrophysics Data System (ADS)

Bech, J.; Reverter, F.; Tume, P.; Roca, N.; Suarez, E.; Sepúlveda, G.; Sokolovska, M.

2012-04-01

Data on the trace element composition of phosphorites is scarce. Some of them may be harmful at certain concentrations. Special concern is given to the radionuclides U and Th and some other heavy metals such as: Co, Cr, Cu, Ni and V. Phosphorites of different origins can vary significantly in the trace element concentrations. 37 samples of phosphorites from 16 deposits were analyzed for Uranium, Thorium and five potential toxic elements (Co, Cr, Cu, Ni and V) as well as 26 samples of data gathered from the literature. In total 63 samples of phosphorites from 20 deposits of 19 countries were studied: Algeria, Australia, Brazil, Burkina Faso, Chile, Colombia, Egypt, India, Israel, Mongolia, Morocco, New Zealand, Peru, Senegal, Syria, Togo, Tunisia, USA and Venezuela. Aqua regia extracts were used to estimate the "pseudototal" values, following standard procedures (ISO 11466, 2002) and measured by ICP-MS. The median concentrations (mgkg-1) obtained were: U 53 (range 0.20-177), Th 4.05 (range 1-49), Co 4 (range 0.5-159), Cr 100 (range 15-1000), Cu 20 (range 5-213), Ni 21 (range 3-850) and V 70.05 (range 20-591). As 120 mgkg-1 of U concentration of phosphorites is the value considered to be useful as a source of nuclear fuel, we now indicate the deposits with values higher than 120 mgkg-1: Khouribga KIISB (Morocco) 121, Khouribga KIISL (Morocco) 123, Champ mines (Idaho, USA) 131, Noralyn (Central Florida, USA) 138, Bone Valley (Florida, USA) 140, Boucraa BGB (Morocco) 141, Boucraa BGC (Morocco) 152, Negev (Israel) 172 and Chatam Rise (New Zealand) 177. The highest Th concentration found was 49 mgkg-1 at Bijawar Group (India). Uranium shows significant positive correlations with V (r = 0.41) and Cr (r = 0.30), and significant negative correlations with Co (r= -0.47). Other positive correlations are Cr with Cu (r=0.58), Cr with V (r=0.52) and Cr with Ni (r=0.51). Cu correlates positively with Ni (r=0.84) and with V (r=0.63). Ni correlates positively with V (r=0.72).

Petroleum pollution in mangrove forests sediments from Qeshm Island and Khamir Port-Persian Gulf, Iran.

PubMed

Ebrahimi-Sirizi, Zohreh; Riyahi-Bakhtiyari, Alireza

2013-05-01

The concentrations of total polycyclic aromatic hydrocarbons (PAHs) and 22 individual PAH compounds in 42 surface sediments collected from the mangrove forest of Qeshm Island and Khamir Port (Persian Gulf) were analyzed. PAHs concentrations ranged from 259 to 5,376 ng g(-1) dry weight with mean and median values of 1,585 and 1,146 ng g(-1), respectively. The mangrove sediments had higher percentages of lower molecular weight PAHs and the PAH profiles were dominated by naphthalene. Ratio values of specific PAH compounds were calculated to evaluate the possible source of PAH contamination. This ratios suggesting that the mangrove sediments have a petrogenic input of PAHs. Sediment quality guidelines were conducted to assess the toxicity of PAH compounds. The levels of total PAHs at all of stations except one station, namely Q6, were below the effects range low. Also, concentrations of naphthalene in some stations exceeded the effects range median.

Assessment of natural and artificial radioactivity levels and radiation hazards and their relation to heavy metals in the industrial area of Port Said city, Egypt.

PubMed

Attia, T E; Shendi, E H; Shehata, M A

2015-02-01

A detailed gamma ray spectrometry survey was carried out to make an action in environmental impact assessment of urbanization and industrialization on Port Said city, Egypt. The concentrations of the measured radioelements U-238, Th-232 in ppm, and K-40 %, in addition to the total counts of three selected randomly dumping sites (A, B, and C) were mapped. The concentration maps represent a base line for the radioactivity in the study area in order to detect any future radioactive contamination. These concentrations are ranging between 0.2 and 21 ppm for U-238 and 0.01 to 13.4 ppm for Th-232 as well as 0.15 to 3.8 % for K-40, whereas the total count values range from 8.7 to 123.6 uR. Moreover, the dose rate was mapped using the same spectrometer and survey parameters in order to assess the radiological effect of these radioelements. The dose rate values range from 0.12 to 1.61 mSv/year. Eighteen soil samples were collected from the sites with high radioelement concentrations and dose rates to determine the activity concentrations of Ra-226, Th-232, and K-40 using HPGe spectrometer. The activity concentrations of Ra-226, Th-232, and K-40 in the measured samples range from 18.03 to 398.66 Bq kg(-1), 5.28 to 75.7 Bq kg(-1), and 3,237.88 to 583.12 Bq kg(-1), respectively. In addition to analyze heavy metal for two high reading samples (a 1 and a 10) which give concentrations of Cd and Zn elements (a 1 40 ppm and a 10 42 ppm) and (a 1 0.90 ppm and a 10 0.97 ppm), respectively, that are in the range of phosphate fertilizer products that suggested a dumped man-made waste in site A. All indicate that the measured values for the soil samples in the two sites of three falls within the world ranges of soil in areas with normal levels of radioactivity, while site A shows a potential radiological risk for human beings, and it is important to carry out dose assessment program with a specifically detailed monitoring program periodically.

The adsorption properties of short chain alcohols and Triton X-100 mixtures at the water-air interface.

PubMed

Zdziennicka, Anna

2009-07-15

The adsorption behaviour at the water-air interface of aqueous solutions of Triton X-100 and methanol (ethanol) mixtures at constant Triton X-100 (TX-100) concentration equal to 10(-7), 10(-6), 10(-5), 10(-4), 6x10(-4) and 10(-3)M, respectively, in a wide range of alcohol concentration was investigated by surface tension measurements of solutions. The obtained values of the surface tension of aqueous solutions of "pure" methanol and ethanol and their mixtures with TX-100, as well as the values of propanol solutions and their mixtures with TX-100 as a function of alcohol concentration taken from the literature were compared with those calculated from the Szyszkowski, Connors and Fainerman and Miller equations. On the basis of this comparison it was stated that these equations can be useful for description of the solution surface tension in the wide range of alcohol concentration, but only at the concentrations of Triton X-100 corresponding to its unsaturated layer in the absence of alcohol. It was also stated that the Connors equation is more adequate for concentrated aqueous organic solutions. The measured values of the surface tension were used in the Gibbs equation to determine the surface excess concentration of Triton X-100 and alcohol. Next, on the basis of Gibbs adsorption isotherms those of Guggenheim and Adam and real adsorption isotherms were established. From the obtained adsorption isotherms it results that alcohol influences the shape of TX-100 isotherms in the whole range of alcohol and TX-100 concentration, but TX-100 influences the alcohol isotherms only at TX-100 concentration at which the saturated monolayer at the solution-air interface is formed in the absence of alcohol. This conclusion was confirmed by analysis of the composition of the surface layer in comparison to the composition of the bulk phase in the equilibrium state.

The criteria for establishing an acceptable range of chemical, physical and biological indicators for the purpose of ecological standards developing

NASA Astrophysics Data System (ADS)

Evdokimova, Maria; Glazunov, Gennady; Yakovlev, Aleksandr

2017-04-01

The basis for development of standards for soil quality is based on the assessment of their resistance to external influences. The main criterion for assessing the environmental sustainability of soils and lands is the ability to perform their ecological functions (Nkonya et al, 2011, 2013; Costanza et al, 2014, Dobrovolsky and Nikitin, 1990; Yakovlev, Evdokimova, 2011). The limiting value of indicators of the state of the environment (physical, chemical, biological and other) corresponds to the value at which stability of environmental components is preserved (the ability to heal itself). Tht threshold for effect of stressor should be identified by the methods of bioindication and biotesting. The analysis obtained by these methods aimed to identify the highest indicator values of physical or chemical (concentration or dose of the stressor) effects, which have not yet fairly established negative changes in the organism, population of organisms or community. Using a theoretical model (Yakovlev et al, 2009, Gendugov., 2013) the problem of finding the threshold concentration is reduced to the finding of the singular points characterizing macroscopic "kinetics" of response in the phase space of dependence of the response rate upon the impact indicator. Singular points are determined by the analysis of derivatives. The theoretical model allows to calculate the singular points of the model (six of them), one of which, the maximum point corresponds to the highest concentration of the stressor at which it had no adverse effects on the test organisms. This point corresponds to the lowest concentration of the stressor at which it has no longer a stimulatory (hormesis) effect. Six singular points divide the whole range of stressors values (concentration) on seven bands with a unique range for each set of values of "macrokinetic" indicators of the living cells response to the impact of the stressor (concentration). Thus, the use of theoretical equations allowed us 1) to establish categories (borders) of soil quality on an the empirical scale of environmental quality and 2) to detail the category of quality in the range of hormesis, that is, in the range of weak positive effects of the stressor. The solution of the equation in the phase space of dependence of response upon exposure is: q=C/z^b*exp(-K/z), where q - is a measurable response of living organisms on exposure to the stressor, the concentration of which is equal to z; C -the constant of integration that makes sense of coefficient, which is scaling the value of q; b - the coefficient of the growth rate responding on the increase of z; K - the coefficient of the decline rate of q responding with increasing z. The equation coefficients C, b, K are found by fitting the model to the experimental data got by the method of nonlinear regression using an available software package. The abscissa of the maximum point is of a particular interest, because it corresponds to: 1. the lowest concentration of the stressor, which does not manifest its stimulatory (hormesis) effect, and at the same time - 2. the largest concentration of the stressor, which has not shown its negative effect. That is, it meets the requirements for threshold concentrations of the stressor and can be used in the development of the environmental quality standards. Acknowledgments: This study was supported by the Russian Science Foundation, project no. 143800023.

CO32- concentration and pCO2 thresholds for calcification and dissolution on the Molokai reef flat, Hawaii

USGS Publications Warehouse

Yates, K.K.; Halley, R.B.

2006-01-01

The severity of the impact of elevated atmospheric pCO2 to coral reef ecosystems depends, in part, on how sea-water pCO2 affects the balance between calcification and dissolution of carbonate sediments. Presently, there are insufficient published data that relate concentrations of pCO 2 and CO32- to in situ rates of reef calcification in natural settings to accurately predict the impact of elevated atmospheric pCO2 on calcification and dissolution processes. Rates of net calcification and dissolution, CO32- concentrations, and pCO2 were measured, in situ, on patch reefs, bare sand, and coral rubble on the Molokai reef flat in Hawaii. Rates of calcification ranged from 0.03 to 2.30 mmol CaCO3 m-2 h-1 and dissolution ranged from -0.05 to -3.3 mmol CaCO3 m-2 h-1. Calcification and dissolution varied diurnally with net calcification primarily occurring during the day and net dissolution occurring at night. These data were used to calculate threshold values for pCO2 and CO32- at which rates of calcification and dissolution are equivalent. Results indicate that calcification and dissolution are linearly correlated with both CO32- and pCO2. Threshold pCO2 and CO32- values for individual substrate types showed considerable variation. The average pCO2 threshold value for all substrate types was 654??195 ??atm and ranged from 467 to 1003 ??atm. The average CO32- threshold value was 152??24 ??mol kg-1, ranging from 113 to 184 ??mol kg-1. Ambient seawater measurements of pCO2 and CO32- indicate that CO32- and pCO2 threshold values for all substrate types were both exceeded, simultaneously, 13% of the time at present day atmospheric pCO2 concentrations. It is predicted that atmospheric pCO2 will exceed the average pCO2 threshold value for calcification and dissolution on the Molokai reef flat by the year 2100.

Physicochemical properties of some bottled water brands in Alexandria Governorate, Egypt.

PubMed

Ibrahim, Hesham Z; Mohammed, Heba A G; Hafez, Afaf M

2014-08-01

Many people use bottled water instead of tap water for many reasons such as taste, ease of carrying, and thinking that it is safer than tap water. Irrespective of the reason, bottled water consumption has been steadily growing in the world for the past 30 years. In Egypt, this is still increasing to reach 3.8 l/person/day, despite its high price compared with tap water. The purpose of this study was to evaluate the physicochemical quality of some bottled water brands and to compare the quality with that reported on manufacture's labeling, Egyptian, and International standards. Fourteen bottled water brands were selected from the local markets of Alexandria city. Three bottles from each brand were randomly sampled, making a total sample size of 42 bottles. Sampling occurred between July 2012 and September 2012. Each bottle was analyzed for its physicochemical parameter and the average was calculated for each brand. The results obtained were compared with the Egyptian standard for bottled water, Food and Drug Administration (FDA), and with bottled water labels. In all bottles in the study, pH values ranged between 7.21 and 8.23, conductivity ranged between 195 and 675 μs/cm, and total dissolved solids, sulfate, chloride, and fluoride were within the range specified by the FDA. Calcium concentrations ranged between 2.7373 and 29.2183 mg/l, magnesium concentrations ranged between 5.7886 and 17.6633 mg/l, sodium between 14.5 and 205.8 mg/l, and potassium between 6.5 and 29.8 mg/l. For heavy metals such as iron, zinc, copper, and manganese, all of them were in conformity with the Egyptian standards and FDA, but nickel concentration in 11 brands was higher than the Egyptian standards. Twelve brands were higher than the Egyptian standards in cadmium concentration, but on comparison with FDA there were only five brands exceeding limits. Lead concentrations were out of range for all brands. On comparison with the labeled values, the quality of bottled water was not complying with labeled values. Physicochemical parameters in all bottled water examined brands were consistent with the Egyptian Standard and FDA, except for total dissolved solids, nickel, cadmium, and lead. Statistical analysis showed that there was significant difference (P<0.05) in all parameters tested between different brands. Values on the bottled water labels were not in agreement with analytical results.

Health and mineral nutrition status of yaks in southern Mustang, Nepal.

PubMed

Kumagai, Hajime; Nakajima, Mitsumi; Anzai, Hiroki; Sakai, Takashi; Oishi, Kazato; Hirooka, Hiroyuki; Shah, Manoj Kumar

2017-08-01

Biochemical values and mineral concentrations in blood plasma were investigated to evaluate the statuses of health and mineral nutrition among yaks in Mustang District, Nepal. In total, 118 plasma samples of female yaks collected in April and September/October of 2013-2015 were offered. Seventy-four percent of yaks showed lower plasma total-cholesterol concentrations than the lowest limit of reference range (100 mg/dL) and the values in spring (83.41 mg/dL) were lower (P < 0.05) than those in autumn (95.05 mg/dL). All the yaks had lower plasma albumin concentrations than the lowest limit of reference range (3.0 g/dL) and 66% of yaks showed lower plasma inorganic phosphorus concentrations than the critical level of phosphorus deficiency (4.5 mg/dL). Thirty-five percent of yaks showed lower plasma calcium concentrations than the lowest limit of normal range (8 mg/dL) and the concentrations were lower in spring than in autumn (P < 0.01). Seventy-five percent of yaks presented lower copper concentrations than the critical level (0.65 mg/L) and the concentrations were lower in spring than in autumn (P < 0.01). Since the low plasma total-cholesterol might have indicated shortage of dry matter and energy intake, attention should be paid to the nutritional statuses of energy, phosphorus, calcium and copper in winter and early spring. © 2016 Japanese Society of Animal Science.

Biological activities of extracts from cultivated Granadilla Passiflora alata

PubMed Central

Vasic, Sava M.; Stefanovic, Olgica D.; Licina, Braho Z.; Radojevic, Ivana D.; Comic, Ljiljana R.

2012-01-01

Research conducted in this study showed the influence of ethanol, acetone and ethyl acetate extracts of the outgrowth of cultivated Passiflora alata on microorganisms, as well as the antioxidant activity and the concentrations of total phenols, flavonoids and tannins. In vitro antimicrobial activities of extracts were studied on 27 species of microorganisms, of which 17 species of bacteria and 10 species of fungi. The strongest antimicrobial activity was detected on G+ bacteria while the activities on other species were moderate. Ethyl acetate extract showed the strongest effect. The concentrations of total phenols were examined by using Folin-Ciocalteu reagent and the obtained values ranged from 14.04 to 34.22 mg GA/g. By using aluminium chloride method, the concentrations of flavonoids were obtained and the values ranged from 33.19 to 62.30 mg RU/g. In determining the amount of tannins we used the method with buthanol-HCl reagent and the obtained value was 5.1 % of dry matter. The efficiency of antioxidation, which we identified through the reduction of DPPH, was in the range from 808.69 to 1107.79 µg/ml for a particular IC50, and AAI values were between 0.07 and 0.10. The best parameters were shown by ethanol extract. All data were statistically analyzed. Overall, extracts showed potential for further investigation and use. PMID:27385958

Effects of lipid concentration on anaerobic co-digestion of municipal biomass wastes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Yifei, E-mail: sunif@buaa.edu.cn; Wang, Dian; Yan, Jiao

2014-06-01

Highlights: • Lipid in municipal biomass would not inhibited the anaerobic digestion process. • A lipid concentration of 65% of total VS was the inhibition concentration. • The amount of Brevibacterium decreased with the increasing of the lipid contents. • Long chain fatty acids stacked on the methanogenic bacteria and blocked the mass transfer process. - Abstract: The influence of the lipid concentration on the anaerobic co-digestion of municipal biomass waste and waste-activated sludge was assessed by biochemical methane potential (BMP) tests and by bench-scale tests in a mesophilic semi-continuous stirred tank reactor. The effect of increasing the volatile solidmore » (VS) concentration of lipid from 0% to 75% was investigated. BMP tests showed that lipids in municipal biomass waste could enhance the methane production. The results of bench-scale tests showed that a lipids concentration of 65% of total VS was the inhibition concentration. Methane yields increased with increasing lipid concentration when lipid concentrations were below 60%, but when lipid concentration was set as 65% or higher, methane yields decreased sharply. When lipid concentrations were below 60%, the pH values were in the optimum range for the growth of methanogenic bacteria and the ratios of volatile fatty acid (VFA)/alkalinity were in the range of 0.2–0.6. When lipid concentrations exceeded 65%, the pH values were below 5.2, the reactor was acidized and the values of VFA/alkalinity rose to 2.0. The amount of Brevibacterium decreased with increasing lipid content. Long chain fatty acids stacked on the methanogenic bacteria and blocked the mass transfer process, thereby inhibiting anaerobic digestion.« less

Screening of antimicrobial, antioxidant properties and bioactive compounds of some edible mushrooms cultivated in Bangladesh.

PubMed

Chowdhury, Mohammed; Kubra, Khadizatul; Ahmed, Sheikh

2015-02-07

For a long time mushrooms have been playing an important role in several aspects of the human activity. Recently edible mushrooms are used extensively in cooking and make part of new food in Bangladesh for their beneficial properties. The aim of this study is to screen some values of mushrooms used in Bangladesh. Methanolic extracts of 3 edible mushrooms (Pleurotus ostreatus, Lentinula edodes, Hypsizigus tessulatus) isolated from Chittagong, Bangladesh were used in this study. Phenolic compounds in the mushroom methanolic extracts were estimated by a colorimetric assay. The antioxidant activity was determined by radical 1, 1-diphenyl;-2-picrylhydrazyl (DPPH) radical scavenging assay. Eight microbial isolates were used for antimicrobial activity of methanolic extract of mushrooms by the agar well diffusion method with slight modification. Determination of antimicrobial activity indicated considerable activity against all bacteria and fungi reveling zone of inhibition ranged from 7 ± 0.2 to 20 ± 0.1 mm. Minimum inhibitory concentration values of the extracts showed that they are also active even in least concentrations ranged from 1 mg/ml to 9 mg/ml. Lentinula edodes showed the best antimicrobial activity than others. Pseudomonas aeruginosa was quite resistant and Saccharomyces cerevisiae was more sensitive than others microbial isolates. Antioxidant efficiency by inhibitory concentration on 1,1-Diphenly-2-picrylhydrazyl (DPPH) was found significant when compared to standard antioxidant like ascorbic Acid . The concentration (IC50) ranged from 100 ± 1.20 to 110 ± 1.24 μg/ml. Total phenols are the major bioactive component found in extracts of isolates expressed as mg of GAE per gram of fruit body, which ranged from 3.20 ± 0.05 to 10.66 ± 0.52 mg/ml. Average concentration of flavonoid ranged from 2.50 ± 0.008 mg/ml to 4.76 ± 0.11 mg/ml; followed by very small concentration of ascorbic acid (range, 0.06 ± 0.00 mg/ml to 0.21 ± 0.01 mg/ml) in all the isolates. All the isolates showed high phenol and flavonoid content (except Pleurotus ostreatus), but ascorbic acid content was found in traces. This study has revealed that selected edible mushrooms have not only nutritional values but also some therapeutic values. Proper and more investigations can lead us to use these as strong medicine in future.

Evaluation of serum haptoglobin and C-reactive protein in dogs with mammary tumors.

PubMed

Planellas, Marta; Bassols, Anna; Siracusa, Carlo; Saco, Yolanda; Giménez, Mercè; Pato, Raquel; Pastor, Josep

2009-09-01

In veterinary medicine, there is increasing interest in measuring acute phase proteins as a tool in the diagnosis and monitoring of neoplastic diseases. Although mammary neoplasms are the most common type of cancer in dogs, acute phase proteins have not been extensively evaluated in dogs with mammary tumors. The aim of this study was to evaluate serum haptoglobin (Hp) and C-reactive protein (CRP) concentrations in the dogs with mammary tumors and assess their potential association with malignancy. A retrospective study of dogs with mammary tumors was performed. Serum concentrations of CRP and Hp were determined in healthy control dogs (n=20) and dogs with mammary tumors before surgery (n=41). Mammary tumors were grouped as carcinomas (n=24), fibrosarcoma (n=1), malignant mixed tumors (n=7), benign mixed tumors (n=6), and adenomas (n=3). CRP and Hp concentrations were compared in dogs with different tumor types and were also compared based on tumor size, lymph node infiltration, skin ulceration, fixation to underlying tissue, and time between tumor identification and removal. Hp concentration was significantly (P<.043) higher in dogs with mammary tumors (median 2.03 g/L, range 0.09-2.94 g/L) compared with controls (1.38 g/L, range 0.08-3.00 g/L), but the range of values overlapped considerably. CRP concentration was higher in dogs with carcinomas (4.70 mg/L, range 0.63-128.96 mg/L) vs controls (2.11 mg/L, range 0.25-6.57 mg/L) (P=.0008) and in dogs with ulcerated skin (14.8 mg/L, range 5.7-128.9 mg/L, n=3) compared with those without ulceration (2.4 mg/L, range 0.11-30.3 mg/L, n=38) (P=.048). Serum Hp and CRP do not appear to have value in diagnosing or predicting malignancy of mammary tumors in dogs. Higher CRP concentrations in dogs with mammary carcinoma suggest a role for inflammation in this tumor type.

Determination of 137Cs activity in soil from Qatar using high-resolution gamma-ray spectrometry

NASA Astrophysics Data System (ADS)

Al-Sulaiti, Huda; Nasir, Tabassum; Al Mugren, K. S.; Alkhomashi, N.; Al-Dahan, N.; Al-Dosari, M.; Bradley, D. A.; Bukhari, S.; Matthews, M.; Regan, P. H.; Santawamaitre, T.; Malain, D.; Habib, A.; Al-Dosari, Hanan; Al Sadig, Ibrahim; Daar, Eman

2016-10-01

With interest in establishing baseline concentrations of 137Cs in soil from the Qatarian peninsula, we focus on determination of the activity concentrations in 129 soil samples collected across the State of Qatar prior to the 2011 Fukushima Dai-ichi nuclear power plant accident. As such, the data provides the basis of a reference map for the detection of releases of this fission product. The activity concentrations were measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector enclosed in a copper-lined passive lead shield that was situated in a low-background environment. The activity concentrations ranged from 0.21 to 15.41 Bq/kg, with a median value of 1 Bq/kg, the greatest activity concentration being observed in a sample obtained from northern Qatar. Although it cannot be confirmed, it is expected that this contamination is mainly due to releases from the Chernobyl accident of 26 April 1986, there being a lack of data from Qatar before the accident. The values are typically within but are sometimes lower than the range indicated by data from other countries in the region. The lower values than those of others is suggested to be due to variation in soil characteristics as well as metrological factors at the time of deposition.

Determining CDOM Absorption Spectra in Diverse Aquatic Environments Using a Multiple Pathlength, Liquid Core Waveguide System

NASA Technical Reports Server (NTRS)

Miller, Richard L.; Belz, Mathias; DelCastillo, Carlos; Trzaska, Rick

2001-01-01

We evaluated the accuracy, sensitivity and precision of a multiple pathlength, liquid core waveguide (MPLCW) system for measuring colored dissolved organic matter (CDOM) absorption in the UV-visible spectral range (370-700 nm). The MPLCW has four optical paths (2.0, 9.8, 49.3, and 204 cm) coupled to a single Teflon AF sample cell. Water samples were obtained from inland, coastal and ocean waters ranging in salinity from 0 to 36 PSU. Reference solutions for the MPLCW were made having a refractive index of the sample. CDOM absorption coefficients, aCDOM, and the slope of the log-linearized absorption spectra, S, were compared with values obtained using a dual-beam spectrophotometer. Absorption of phenol red secondary standards measured by the MPLCW at 558 nm were highly correlated with spectrophotometer values and showed a linear response across all four pathlengths. Values of aCDOM measured using the MPLCW were virtually identical to spectrophotometer values over a wide range of concentrations. The dynamic range of aCDOM for MPLCW measurements was 0.002 - 231.5 m-1. At low CDOM concentrations spectrophotometric aCDOM were slightly greater than MPLCW values and showed larger fluctuations at longer wavelengths due to limitations in instrument precision. In contrast, MPLCW spectra followed an exponential to 600 nm for all samples.

Distribution and variation of arsenic in Wisconsin surface soils, with data on other trace elements

USGS Publications Warehouse

Stensvold, Krista A.

2012-01-01

Soils with sandy glacial outwash as a parent material have a lower median arsenic concentration (1.0 mg/kg) than soils forming in other parent materials (1.5 to 3.0 mg/kg). Soil texture and drainage category also influence median arsenic concentration. Finer grained soils have a higher observed range of concentrations. For loamy and loess-dominated soil groups, drainage category influences the median arsenic concentration and observed range of values, but a consistent relationship within the data is not apparent. Statistical analysis of the 16 other elements are presented in this report, but the relationships of concentrations to soil properties or geographic areas were not examined.

Direct URCA process in neutron stars

NASA Technical Reports Server (NTRS)

Lattimer, James M.; Prakash, Madappa; Pethick, C. J.; Haensel, Pawel

1991-01-01

It is shown that the direct URCA process can occur in neutron stars if the proton concentration exceeds some critical value in the range 11-15 percent. The proton concentration, which is determined by the poorly known symmetry energy of matter above nuclear density, exceeds the critical value in many current calculations. If it occurs, the direct URCA process enhances neutrino emission and neutron star cooling rates by a large factor compared to any process considered previously.

Trace Elements and Oxygen Isotope Zoning of the Sidewinder Skarn

NASA Astrophysics Data System (ADS)

Draper, C.; Gevedon, M. L.; Barnes, J.; Lackey, J. S.; Jiang, H.; Lee, C. T.

2016-12-01

Skarns of the Verde Antique Quarry and White Horse Mountain areas of the Sidewinder Range give insight into the paleohydrothermal systems operating in the California's Jurassic arc in the Southwestern Mojave Desert. Garnet from these skarns is iron rich: Xand= 55-100. Laser fluorination measurements show oxygen isotope (δ18O) compositions of garnet crystals and crystals domains have large ranges: -3.1‰ to +4.4‰ and -8.9‰ to +3.4‰, respectively. In general, the garnet cores have more negative δ18O values than rims, although oscillations are present. Negative values have been interpreted as influx of meteoric fluid and positive values as increased magmatic input. Here we report major and trace element concentrations for 17 core to rim Sidewinder garnet transects. REEs concentrations are low in all crystals, with total REE concentrations ranging from 0.710 ppm to 33.7 ppm, values that are lower than Cretaceous skarn garnets in the Sierra Nevada in the White Chief and Empire Mt skarns. Such low concentrations are likely due to the higher fraction of meteoric fluids during formation of the Sidewinder skarns. REE concentrations decrease from core to rim (REE core average=12.2ppm, REE rim average=7.21ppm). This is slightly more pronounced in the LREEs than in the HREEs (LaN/YbN core average= 10.9; rim average= 9.73, normalized to Chondrite). X­and tends to decrease core to rim in the Verde Antique skarn, whereas, Xand of the White Horse skarn does not correlate with distance from core. A large positive Eu anomaly (Eu/Eu* = 3­-30) in garnet from both skarns suggests oxidizing fluid conditions. Oxygen isotope data from garnet in these same skarns show periods of time with increased proportion of magmatic derived fluids in the total fluid budget. However, there is no corresponding widespread increase in total REE concentrations. Other studies of skarns from the western Sierra Nevadan arc (White Chief and Empire Mountain) observe complete decoupling of d18O values and trace element compositions. Future modeling should consider modal abundance of fluid soluble minerals in cooling and altering plutons to probe the REE budget.

First radon measurements and occupational exposure assessments in underground geodynamic laboratory the Polish Academy of Sciences Space Research Centre in Książ Castle (SW Poland).

PubMed

Fijałkowska-Lichwa, Lidia; Przylibski, Tadeusz A

2016-12-01

The article presents the results of the first radon activity concentration measurements conducted continuously between 17 th May 2014 and 16 th May 2015 in the underground geodynamic laboratory of the Polish Academy of Sciences Space Research Centre in Książ. The data were registered with the use of three Polish semiconductor SRDN-3 detectors located the closest (SRDN-3 No. 6) to and the furthest (SRDN-3 No. 3) from the facility entrance, and in the fault zone (SRDN-3 No. 4). The study was conducted to characterize the radon behaviour and check it possibility to use with reference to long- and short-term variations of radon activity concentration observed in sedimentary rocks strongly fractured and intersected by systems of multiple faults, for integrated comparative assessments of changes in local orogen kinetics. The values of radon activity concentration in the underground geodynamic laboratory of the Polish Academy of Sciences (PAN) Space Research Centre in Książ undergo changes of a distinctly seasonal character. The highest values of radon activity concentration are recorded from late spring (May/June) to early autumn (October), and the lowest - from November to April. Radon activity concentrations varied depending on the location of measurement points. Between late spring and autumn they ranged from 800 Bq·m -3 to 1200 Bq·m -3 , and even 3200 Bq·m -3 in the fault zone. Between November and April, values of radon activity concentration are lower, ranging from 500 Bq·m -3 to 1000 Bq·m -3 and 2700 Bq·m -3 in the fault zone. The values of radon activity concentration recorded in the studied facility did not undergo short-term changes in either the whole annual measuring cycle or any of its months. Effective doses received by people staying in the underground laboratory range from 0.001 mSv/h to 0.012 mSv/h. The mean annual effective dose, depending on the measurement site, equals 1 or is slightly higher than 10 mSv/year, while the maximum dose exceeds 20 mSv/year. The estimated annual effective doses are comparable to the standard value of 20 mSv/year defined by Polish law for people employed in the conditions of radiation exposure. They are also in the range of annual effective dose value (8 mSv/year) recommended in workplaces by International Commission on Radiation Protection. Copyright © 2016 Elsevier Ltd. All rights reserved.

Relation of electrochemical potentials and iron content to ground-water flow patterns

USGS Publications Warehouse

Back, William; Barnes, Ivan

1965-01-01

This study was undertaken to develop means of measuring oxidation potentials in aquifer systems and to use the measured values in interpreting the behavior of iron in ground water. Anne Arundel County, Md., was selected as the area of study because of the wide range of concentration of iron-nearly zero to about 35 ppm-in the ground water and the rather complete information on the geology and hydrology. The regional geology consists of coastal plain sediments ranging in age from Early Cretaceous through the Recent. Most of the pH and oxidation-potential measurements were made in nonmarine Cretaceous deposits, only a few in the marine Eocene. Iron-bearing minerals in the area are primarily hematite or limonite and glauconite with a small amount of pyrite. Equipment was developed that permits the measurement of oxidation potentials by use of saturated calomel and platinum electrodes in ground-water samples uncontaminated by oxygen of the atmosphere. Measured Eh values range from about +700 mv to -40 mv. Approximately 2 to 3 hours are required to measure a stable or nearly stable oxidation potential. The mineralogy and organic content of the deposits and the ground-water flow pattern are the primary controls on the oxidation potential and pH of the water. A correlation exists between the oxidation potential and the concentration of iron in ground water; the higher concentrations occur in waters with the lowest values of Eh. The concentration of iron in the water tested shows little correlation with the pH of the water. The highest oxidation potentials were measured in water produced from shallow wells and those wells in recharge areas. The lowest potentials were measured farthest downgradient in water associated with gray and green sediments. The Eh values measured in the field are between values predicted from the solubility of Fe(OH)2(c) and values predicted from the solubility of hematite.

Osmotic potential calculations of inorganic and organic aqueous solutions over wide solute concentration levels and temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cochrane, T. T., E-mail: agteca@hotmail.com; Cochrane, T. A., E-mail: tom.cochrane@canterbury.ac.nz

Purpose: To demonstrate that the authors’ new “aqueous solution vs pure water” equation to calculate osmotic potential may be used to calculate the osmotic potentials of inorganic and organic aqueous solutions over wide ranges of solute concentrations and temperatures. Currently, the osmotic potentials of solutions used for medical purposes are calculated from equations based on the thermodynamics of the gas laws which are only accurate at low temperature and solute concentration levels. Some solutions used in medicine may need their osmotic potentials calculated more accurately to take into account solute concentrations and temperatures. Methods: The authors experimented with their newmore » equation for calculating the osmotic potentials of inorganic and organic aqueous solutions up to and beyond body temperatures by adjusting three of its factors; (a) the volume property of pure water, (b) the number of “free” water molecules per unit volume of solution, “N{sub f},” and (c) the “t” factor expressing the cooperative structural relaxation time of pure water at given temperatures. Adequate information on the volume property of pure water at different temperatures is available in the literature. However, as little information on the relative densities of inorganic and organic solutions, respectively, at varying temperatures needed to calculate N{sub f} was available, provisional equations were formulated to approximate values. Those values together with tentative t values for different temperatures chosen from values calculated by different workers were substituted into the authors’ equation to demonstrate how osmotic potentials could be estimated over temperatures up to and beyond bodily temperatures. Results: The provisional equations formulated to calculate N{sub f}, the number of free water molecules per unit volume of inorganic and organic solute solutions, respectively, over wide concentration ranges compared well with the calculations of N{sub f} using recorded relative density data at 20 °C. They were subsequently used to estimate N{sub f} values at temperatures up to and excess of body temperatures. Those values, together with t values at temperatures up to and in excess of body temperatures recorded in the literature, were substituted in the authors’ equation for the provisional calculation of osmotic potentials. The calculations indicated that solution temperatures and solute concentrations have a marked effect on osmotic potentials. Conclusions: Following work to measure the relative densities of aqueous solutions for the calculation of N{sub f} values and the determination of definitive t values up to and beyond bodily temperatures, the authors’ equation would enable the accurate estimations of the osmotic potentials of wide concentrations of aqueous solutions of inorganic and organic solutes over the temperature range. The study illustrates that not only solute concentrations but also temperatures have a marked effect on osmotic potentials, an observation of medical and biological significance.« less

[Study of fusion of bacteriophage f2 double-stranded RNA, poly(A).poly(U), and poly(G).poly(C) in the presence of tetraethylammonium bromide].

PubMed

Permogorov, V I; Tiaglov, B V; Minaev, V E

1980-01-01

The data on the dependence of the melting curve parameters of double-stranded RNA (replicative form of RNA of f2 bacteriophage) poly(A) times poly(U) and poly(G) times poly(C) on the concentration of (C2H5)4NBr were obtained. The RNA melting range width is shown to pass through the minimum value T =2.1+/-0.1degrees at the point of inversion of relative stability of GC and AU pairs that corresponds to 4.0+/-0.1 M concentration of (C2H5)4NBr. Using the melting temperatures of poly(A) times poly(U) and poly(G) times poly(C) the rependence of Tgc-Tau parameter on (C2H5)4NBr concentration was shown. It was concluded from these data that the effect of the double-stranded RNA stacking heterogeneity was negligible in the 0-3 M range of (C2H5)4NBr concentration. Melting curves of RNA were obtained at various values of Tgc-Tau parameter. It was shown that the profile of fine structure of melting curves depends on the value of Tgc-Tau parameter.

Effect of process parameters and operational mode on nitrous oxide emissions from a nitritation reactor treating reject wastewater.

PubMed

Pijuan, Maite; Torà, Josep; Rodríguez-Caballero, Adrián; César, Elvira; Carrera, Julián; Pérez, Julio

2014-02-01

Nitrous oxide (N2O) and methane emissions were monitored in a continuous granular airlift nitritation reactor from ammonium-rich wastewater (reject wastewater). N2O emissions were found to be dependent on dissolved oxygen (DO) concentration in the range of 1-4.5 mg O2/L, increasing within this range when reducing the DO values. At higher DO concentrations, N2O emissions remained constant at 2.2% of the N oxidized to nitrite, suggesting two different mechanisms behind N2O production, one dependent and one independent of DO concentration. Changes on ammonium, nitrite, free ammonia and free nitrous acid concentrations did not have an effect on N2O emissions within the concentration range tested. When operating the reactor in a sequencing batch mode under high DO concentration (>5 mg O2/L), N2O emissions increased one order of magnitude reaching values of 19.3 ± 7.5% of the N oxidized. Moreover, CH4 emissions detected were due to the stripping of the soluble CH4 that remained dissolved in the reject wastewater after anaerobic digestion. Finally, an economical and carbon footprint assessment of a theoretical scaled up of the pilot plant was conducted. Copyright © 2013 Elsevier Ltd. All rights reserved.

Convection in colloidal suspensions with particle-concentration-dependent viscosity.

PubMed

Glässl, M; Hilt, M; Zimmermann, W

2010-07-01

The onset of thermal convection in a horizontal layer of a colloidal suspension is investigated in terms of a continuum model for binary-fluid mixtures where the viscosity depends on the local concentration of colloidal particles. With an increasing difference between the viscosity at the warmer and the colder boundary the threshold of convection is reduced in the range of positive values of the separation ratio psi with the onset of stationary convection as well as in the range of negative values of psi with an oscillatory Hopf bifurcation. Additionally the convection rolls are shifted downwards with respect to the center of the horizontal layer for stationary convection psi>0 and upwards for the Hopf bifurcation (psi<0.

Establishment of reference values for various coagulation tests in healthy Florida manatees (Trichechus manatus latirostris) and evaluation of coagulation in debilitated manatees during rehabilitation.

PubMed

Gerlach, Trevor J; Bandt, Carsten; Conner, Bobbi; Ball, Ray L

2015-11-01

To establish reference ranges for coagulation parameters in healthy Florida manatees (Trichechus manatus latirostris) and compare results with those for debilitated manatees undergoing treatment at a rehabilitation facility. Prospective study. 29 healthy manatees and 45 debilitated manatees with various diseases. Manatees considered healthy on the basis of results of physical examination, CBC, and serum biochemical analysis underwent coagulation testing including measurement of prothrombin time, partial thromboplastin time, D-dimer concentration, platelet count, and fibrinogen concentration to establish reference ranges. For comparison, a group of manatees undergoing rehabilitation was also tested, and the results were compared. Thromboelastography was also performed on some animals. Values for D-dimer concentration were significantly higher in debilitated versus healthy animals. There was no significant difference for prothrombin time, partial thromboplastin time, platelet count, or fibrinogen concentration between groups. Thromboelastography was performed on 8 healthy animals. Reference ranges were established for various tests of coagulation that may assist clinicians during the initial evaluation and rehabilitation of Florida manatees. Future research to evaluate the effect of specific disease processes on the coagulation cascade is recommended.

From the Cover: Manganese Stimulates Mitochondrial H2O2 Production in SH-SY5Y Human Neuroblastoma Cells Over Physiologic as well as Toxicologic Range

PubMed Central

Fernandes, Jolyn; Hao, Li; Bijli, Kaiser M.; Chandler, Joshua D.; Orr, Michael; Hu, Xin; Jones, Dean P.

2017-01-01

Manganese (Mn) is an abundant redox-active metal with well-characterized mitochondrial accumulation and neurotoxicity due to excessive exposures. Mn is also an essential co-factor for the mitochondrial antioxidant protein, superoxide dismutase-2 (SOD2), and the range for adequate intake established by the Institute of Medicine Food and Nutrition Board is 20% of the interim guidance value for toxicity by the Agency for Toxic Substances and Disease Registry, leaving little margin for safety. To study toxic mechanisms over this critical dose range, we treated human neuroblastoma SH-SY5Y cells with a series of MnCl2 concentrations (from 0 to 100 μM) and measured cellular content to compare to human brain Mn content. Concentrations ≤10 μM gave cellular concentrations comparable to literature values for normal human brain, whereas concentrations ≥50 μM resulted in values comparable to brains from individuals with toxic Mn exposures. Cellular oxygen consumption rate increased as a function of Mn up to 10 μM and decreased with Mn dose ≥50 μM. Over this range, Mn had no effect on superoxide production as measured by aconitase activity or MitoSOX but increased H2O2 production as measured by MitoPY1. Consistent with increased production of H2O2, SOD2 activity, and steady-state oxidation of total thiol increased with increasing Mn. These findings have important implications for Mn toxicity by re-directing attention from superoxide anion radical to H2O2-dependent mechanisms and to investigation over the entire physiologic range to toxicologic range. Additionally, the results show that controlled Mn exposure provides a useful cell manipulation for toxicological studies of mitochondrial H2O2 signaling. PMID:27701121

ARM Evaluation Product : Droplet Number Concentration Value-Added Product

DOE Data Explorer

Riihimaki, Laura

2014-05-15

Cloud droplet number concentration is an important factor in understanding aerosol-cloud interactions. As aerosol concentration increases, it is expected that droplet number concentration, Nd, will increase and droplet size decrease, for a given liquid water path (Twomey 1977), which will greatly affect cloud albedo as smaller droplets reflect more shortwave radiation. However, the magnitude and variability of these processes under different environmental conditions is still uncertain. McComiskey et al. (2009) have implemented a method, based on Boers and Mitchell (1994), for calculating Nd from ground-based remote sensing measurements of optical depth and liquid water path. They show that the magnitude of the aerosol-cloud interactions (ACI) varies with a range of factors, including the relative value of the cloud liquid water path (LWP), the aerosol size distribution, and the cloud updraft velocity. Estimates of Nd under a range of cloud types and conditions and at a variety of sites are needed to further quantify the impacts of aerosol cloud interactions.

Serum biochemistry of captive and free-ranging gray wolves (Canis lupus)

USGS Publications Warehouse

Constable, Peter; Hinchcliff, Ken; Demma, Nick; Callahan, Margaret; Dale, B.W.; Fox, Kevin; Adams, Layne G.; Wack, Ray; Kramer, Lynn

1998-01-01

Normal serum biochemistry values are frequently obtained from studies of captive sedentary (zoo) or free-ranging (wild) animals. It is frequently assumed that values from these two populations are directly referable to each other. We tested this assumption using 20 captive gray wolves (Canis lupus) in Minnesota, USA, and 11 free-ranging gray wolves in Alaska, USA. Free-ranging wolves had significantly (P<0.05) lower sodium, chloride, and creatine concentrations and significantly higher potassium and blood urea nitrogen (BUN) concentrations; BUN to creatine ratios; and alanine aminotransferase, aspartate aminotransferase, and creatine kinase activities relative to captive wolves. Corticosteroid-induced alkaline phosphatase activity (a marker of stress in domestic dogs) was detected in 3 of 11 free-ranging wolves and in 0 of 20 captive wolves (P = 0.037). This study provides clear evidence that serum biochemical differences can exist between captive and free-ranging populations of one species. Accordingly, evaluation of the health status of an animal should incorporate an understanding of the potential confounding effect that nutrition, activity level, and environmental stress could have on the factor(s) being measured.

The effects of temperature and salinity on phosphate levels in two euryhaline crustacean species

NASA Astrophysics Data System (ADS)

Spaargaren, D. H.; Richard, P.; Ceccaldi, H. J.

Total phoshate, inorganic phosphate and organic (phospholipid) phosphate concentrations were determined in the blood of Carcinus maenas and in whole-animal homogenates of Penaeus japonicus acclimatized to various salinities and a high or a low temperature. In the blood of Carcinus, total and inorganic P concentrations range between 1.0 and 4.5 mmol · l -1; the amount of phospholipids is negligeable. The higher values were found at more extreme salinities. Low temperature is associated with low phosphate concentrations, particularly at intermediate salinities. Total P concentrations in Penaeus homogenates range between 10 and 60 mmol · 1 -1; phospholipid concentrations range between zero and 50 mmol · 1 -1. The higher values are again found at the extreme salinities. Inorganic P concentrations are almost constant — ca 10 mmol · 1 -1. No apparent effect of temperature on phosphate concentrations was observed. The results show clearly that osmotic stress influences severely the phosphate metabolism of the two species studied. Both species are able to accumulate phosphate at all experimental temperature/salinity combinations used, even when deprived of food. At extreme salinities, large quantities of phosphate are accumulated and converted to organic P compounds, most likely as phospholipids associated with the cell membranes. These effects of osmotic conditions in phosphate metabolism may offer an explanation for the effect of Ca ++ on membrane permeability as the regulation of both ions may be strongly interrelated, often under hormonal control.

Mineral concentrations in diets, water, and milk and their value in estimating on-farm excretion of manure minerals in lactating dairy cows.

PubMed

Castillo, A R; St-Pierre, N R; Silva del Rio, N; Weiss, W P

2013-05-01

Thirty-nine commercial dairies in Merced County, California were enrolled in the present study to (1) compare lactating cow mineral intakes (via drinking water and total mixed ration) to the National Research Council (NRC) requirements, (2) evaluate the association between dietary concentrations of minerals with and without drinking water and adjusted for mineral concentrations in milk, and (3) compare 4 different methods to estimate excretion of minerals using either assays or estimations of milk mineral outputs and total daily mineral intake per cow with or without minerals coming from drinking water. Dairies were selected to represent a range of herd milk yields and a range of water mineral contents. Samples of total mixed ration, drinking water, and bulk tank milk were taken on 2 different days, 3 to 7d apart in each farm. Across-farm medians and percentile distributions were used to analyze results. The herd median milk yield interquartile ranged (10th to 90th percentile) from less than 25 to more than 39 kg/d and the concentration of total solids in water interquartile ranged from less than 200 to more than 1,490 mg/L. Including drinking water minerals in the diets increased dietary concentrations by <4% for all minerals except for Na and Cl, which increased by 9.3 and 6.5%, respectively. Concentrations of P and K in milk were essentially the same as the NRC value to estimate lactation requirements. However, NRC milk values of Ca, Cl, and Zn were 10 to 20% greater than dairy farm values; and Na, Cu, Fe, and Mn were no less than 36% below NRC values. Estimated excretion of minerals via manure varied substantially across farms. Farms in the 10th percentile did have 2 to 3 times less estimated mineral excretions than those in the 90th percentile (depending on the mineral). Although including water minerals increased excretion of most minerals, the actual median effect of Ca, Mg, S, Cu, Fe, and Mn was less than 5%, and about 8% for Na and Cl. Replacing assayed concentrations of minerals in milk with NRC constants resulted in reduced estimated excretion of Ca, Na, Cu, Fe, and Zn, but median differences were <5% except for Na which was 7.5%. Results indicate that not including mineral intake via drinking water and not using assayed concentrations of milk minerals lead to errors in estimation manure excretion of minerals (e.g., Ca, Na, Cl, and S). Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Three new mussel tissue standard reference materials (SRMs) for the determination of organic contaminants.

PubMed

Poster, Dianne L; Schantz, Michele M; Kucklick, John R; Lopez de Alda, Maria J; Porter, Barbara J; Pugh, Rebecca; Wise, Stephen A

2004-03-01

Three new mussel tissue standard reference materials (SRMs) have been developed by the National Institute of Standards and Technology (NIST) for the determination of the concentrations of organic contaminants. The most recently prepared material, SRM 1974b, is a fresh frozen tissue homogenate prepared from mussels ( Mytilus edulis) collected in Boston Harbor, Massachusetts. The other two materials, SRMs 2977 and 2978, are freeze-dried tissue homogenates prepared from mussels collected in Guanabara Bay, Brazil and Raritan Bay, New Jersey, respectively. All three new mussel tissue SRMs complement the current suite of marine natural-matrix SRMs available from NIST that are characterized for a wide range of contaminants (organic and inorganic). SRM 1974b has been developed to replace its predecessor SRM 1974a, Organics in Mussel Tissue, for which the supply is depleted. Similarly, SRMs 2977 and 2978 were developed to replace a previously available (supply depleted) freeze-dried version of SRM 1974a, SRM 2974, Organics in Freeze-Dried Mussel Tissue. SRM 1974b is the third in a series of fresh frozen mussel tissue homogenate SRMs prepared from mussels collected in Boston Harbor starting in 1988. SRM 1974b has certified concentration values for 22 polycyclic aromatic hydrocarbons (PAHs), 31 polychlorinated biphenyl congeners (PCBs), and 7 chlorinated pesticides. Reference values are provided for additional constituents: 16 PAHs, 8 PCBs plus total PCBs, 6 pesticides, total extractable organics, methylmercury, and 11 trace elements. PAH concentrations range from about 2 ng g(-1 )dry mass (cyclopenta[ cd]pyrene) to 180 ng g(-1 )dry mass (pyrene). PCB concentrations range from about 2 ng g(-1 )dry mass (PCB 157) to 120 ng g(-1 )dry mass (PCB 153). The reference value for total PCBs in SRM 1974b is (2020 +/- 420) ng g(-1 )dry mass. Pesticide concentrations range from about 4 ng g(-1 )dry mass (4,4'-DDT) to 40 ng g(-1 )dry mass (4,4'-DDE). SRM 2977 has certified values for 14 PAHs, 25 PCB congeners, 7 pesticides, 6 trace elements, and methylmercury. Reference values for 16 additional PAHs and 9 inorganic constituents are provided, and information values are given for 23 additional trace elements. SRM 2978 has certified and reference concentrations for 41 and 22 organic compounds, respectively, and contains contaminant levels similar to those of SRM 1974b. Organic contaminant levels in SRM 2977 (mussels from Guanabara Bay, Brazil) are typically a factor of 2 to 4 lower than those in SRM 1974b and SRM 2978. The organic contaminant concentrations in each new mussel tissue SRM are presented and compared in this paper. In addition, a chronological review of contaminant concentrations associated with mussels collected in Boston Harbor is discussed as well as a stability assessment of SRM 1974a.

Reference ranges for urinary concentrations and ratios of endogenous steroids, which can be used as markers for steroid misuse, in a Caucasian population of athletes.

PubMed

Van Renterghem, Pieter; Van Eenoo, Peter; Geyer, Hans; Schänzer, Wilhelm; Delbeke, Frans T

2010-02-01

The detection of misuse with naturally occurring steroids is a great challenge for doping control laboratories. Intake of natural anabolic steroids alters the steroid profile. Thus, screening for exogenous use of these steroids can be established by monitoring a range of endogenous steroids, which constitute the steroid profile, and evaluate their concentrations and ratios against reference ranges. Elevated values of the steroid profile constitute an atypical finding after which a confirmatory IRMS procedure is needed to unequivocally establish the exogenous origin of a natural steroid. However, the large inter-individual differences in urinary steroid concentrations and the recent availability of a whole range of natural steroids (e.g. dehydroepiandrosterone and androstenedione) which each exert a different effect on the monitored parameters in doping control complicate the interpretation of the current steroid profile. The screening of an extended steroid profile can provide additional parameters to support the atypical findings and can give specific information upon the steroids which have been administered. The natural concentrations of 29 endogenous steroids and 11 ratios in a predominantly Caucasian population of athletes were determined. The upper reference values at 97.5%, 99% and 99.9% levels were assessed for male (n=2027) and female (n=1004) populations. Monitoring minor metabolites and evaluation of concentration ratios with respect to their natural abundances could improve the interpretation of the steroid profile in doping analysis. Copyright 2009 Elsevier Inc. All rights reserved.

Antimicrobial properties, antioxidant activity and bioactive compounds from six wild edible mushrooms of western ghats of Karnataka, India

PubMed Central

Ramesh, Ch.; Pattar, Manohar G.

2010-01-01

Methanolic extracts of 6 wild edible mushrooms isolated from the Western Ghats of Karnataka were used in this study. Among the isolates (Lycoperdon perlatum, Cantharellus cibarius, Clavaria vermiculris, Ramaria formosa, Marasmius oreades, Pleurotus pulmonarius), only 4 showed satisfactory results. Quantitative analysis of bioactive components revealed that total phenols are the major bioactive component found in extracts of isolates expressed as mg of GAE per gram of fruit body, which ranged from 3.20 ± 0.05 mg/mL to 6.25 ± 0.08 mg/mL. Average concentration of flavonoid ranged from 0.40 ± 0.052 mg/mL to 2.54 ± 0.08 mg/mL; followed by very small concentration of ascorbic acid (range, 0.06 ± 0.01 mg/mL to 0.16 ± 0.01 mg/mL) in all the isolates. All the isolates showed high phenol and flavonoid content, but ascorbic acid content was found in traces. Antioxidant efficiency by inhibitory concentration on 1,1-Diphenly-2-picrylhydrazyl (DPPH) was found significant when compared to standard antioxidant like Buthylated hydroxyanisol (BHA). The concentration (IC50) ranged from 0.94 ± 0.27 mg/mL to 7.57 ± 0.21 mg/mL. Determination of antimicrobial activity profile of all the isolates tested against a panel of standard pathogenic bacteria and fungi indicated that the concentrations of bioactive components directly influence the antimicrobial capability of the isolates. Agar diffusion assay showed considerable activity against all bacteria. Minimum inhibitory concentration values of the extracts of 4 isolates showed that they are also active even in least concentrations. These results are discussed in relation to therapeutic value of the studied mushrooms. PMID:21808550

The refractive index of human hemoglobin in the visible range.

PubMed

Zhernovaya, O; Sydoruk, O; Tuchin, V; Douplik, A

2011-07-07

Because the refractive index of hemoglobin in the visible range is sensitive to the hemoglobin concentration, optical investigations of hemoglobin are important for medical diagnostics and treatment. Direct measurements of the refractive index are, however, challenging; few such measurements have previously been reported, especially in a wide wavelength range. We directly measured the refractive index of human deoxygenated and oxygenated hemoglobin for nine wavelengths between 400 and 700 nm for the hemoglobin concentrations up to 140 g l(-1). This paper analyzes the results and suggests a set of model functions to calculate the refractive index depending on the concentration. At all wavelengths, the measured values of the refractive index depended on the concentration linearly. Analyzing the slope of the lines, we determined the specific refraction increments, derived a set of model functions for the refractive index depending on the concentration, and compared our results with those available in the literature. Based on the model functions, we further calculated the refractive index at the physiological concentration within the erythrocytes of 320 g l(-1). The results can be used to calculate the refractive index in the visible range for arbitrary concentrations provided that the refractive indices depend on the concentration linearly.

Effects of Copper Pollution on the Phenolic Compound Content, Color, and Antioxidant Activity of Wine.

PubMed

Sun, Xiangyu; Ma, Tingting; Han, Luyang; Huang, Weidong; Zhan, Jicheng

2017-05-03

The effects of copper pollution on the polyphenol content, color, and antioxidant activity of wine, as well as correlations among these factors, were investigated. Copper had clear influences on wine polyphenol content. At low copper concentrations, the concentrations of nearly all polyphenols increased, and the antioxidant activity values of the wine also increased. When the copper concentration reached the lowest level of the medium copper range (9.6~16 mg/L), most of the indices also improved. When the copper concentrations reached the latter part of the medium copper range (19.2 and 22.4 mg/L), many of the tested indices began to decrease. Furthermore, when the copper concentration reached the high ranges (32, 64, and 96 mg/L), the polyphenol content, CIELAB color parameters, and antioxidant activity of wine were substantially decreased, indicating the need to control increasing copper content in grape must.

Phosphorus Concentrations in Stream-Water and Reference Samples - An Assessment of Laboratory Comparability

USGS Publications Warehouse

McHale, Michael R.; McChesney, Dennis

2007-01-01

In 2003, a study was conducted to evaluate the accuracy and precision of 10 laboratories that analyze water-quality samples for phosphorus concentrations in the Catskill Mountain region of New York State. Many environmental studies in this region rely on data from these different laboratories for water-quality analyses, and the data may be used in watershed modeling and management decisions. Therefore, it is important to determine whether the data reported by these laboratories are of comparable accuracy and precision. Each laboratory was sent 12 samples for triplicate analysis for total phosphorus, total dissolved phosphorus, and soluble reactive phosphorus. Eight of these laboratories reported results that met comparability criteria for all samples; the remaining two laboratories met comparability criteria for only about half of the analyses. Neither the analytical method used nor the sample concentration ranges appeared to affect the comparability of results. The laboratories whose results were comparable gave consistently comparable results throughout the concentration range analyzed, and the differences among methods did not diminish comparability. All laboratories had high data precision as indicated by sample triplicate results. In addition, the laboratories consistently reported total phosphorus values greater than total dissolved phosphorus values, and total dissolved phosphorus values greater than soluble reactive phosphorus values, as would be expected. The results of this study emphasize the importance of regular laboratory participation in sample-exchange programs.

[Experimental and clinical evaluation latamoxef in newborn and premature infants].

PubMed

Toyonaga, Y; Kurosu, Y; Sugita, M; Kitagawa, M; Hori, M

1983-09-01

Basic and clinical studies of latamoxef (LMOX) were carried out in neonates. In basic study, these neonates consisted of 16 mature babies and 12 premature babies. LMOX was administered at dose of 10 and 20 mg/kg, either as a single intravenous injection or as a 60 minutes intravenous drip infusion. Both the mature babies and the premature babies were divided into 3 subgroups as a function of the number of days after birth (0--3, 4--7 and 8--25 days). A clinical study of LMOX was performed in 12 neonates aged between 0--35 days, consisting 6 males and 6 females. (Purulent meningitis 4 cases, septicemia 1 case, bronchopneumonia 5 cases, pertussis pneumonia 1 case, urinary tract infection 1 case). Serum concentration and urinary excretion 10 mg/kg, one shot intravenous injection In the 3 subgroups of neonates the peak serum concentrations of LMOX were found to range from 14.6 to 28.9 micrograms/ml. Although there was no significant difference, the half-life of the drug became shorter as the age of the neonates increased, these values were 4.46, 3.85 and 3.30 hours, respectively. 10 mg/kg, 60 minutes intravenous drip infusion. As above, the peak LMOX serum concentrations were found to range from 23.7 to 38.9 micrograms/ml, the half-lives of the 3 subgroups were 4.83, 2.48 and 3.01 hours, respectively. And urinary excretions were ranged from 46.0 to 56.5% for 6 hours. 20 mg/kg, one shot intravenous injection The peak serum concentrations were found to range from 31.0--82.5 micrograms/ml, and it was found out 3.29--15.9 micrograms/ml at 8 hours after the injection. There was a tendency for the half-life to be shorter in more mature subjects in 3 subgroups. 20 mg/kg, 60 minutes intravenous drip infusion In the 3 subgroups, the peak concentration was the level existing at the end of the intravenous drip infusion, and that showed a range of 41.8--58.6 micrograms/ml. Half-lives were found out the significant difference to their age, these showed 4.08, 2.31 and 2.52 hours. Cerebrospinal fluid concentrations of LMOX Cerebrospinal fluid concentrations of LMOX were studied in 2 cases at the dose about 50 mg/kg. In 1 case, that's meningitis estimated E. coli organism, the cerebrospinal fluid concentrations of LMOX were found to range from 29.0 to 49.9 micrograms/ml in that acute state. In another case from N. meningitidis, that values were found to range 12.1 to 21.3 micrograms/ml. These cerebrospinal levels were superior value at it's penetration ratio. Clinical studies.(ABSTRACT TRUNCATED AT 400 WORDS)

A new insight on the dynamics of sodium dodecyl sulfate aqueous micellar solutions by dielectric spectroscopy.

PubMed

Lanzi, Leandro; Carlà, Marcello; Lanzi, Leonardo; Gambi, Cecilia M C

2009-02-01

Aqueous sodium dodecyl sulfate micellar solutions were investigated by a recently developed double-differential dielectric spectroscopy technique in the frequency range 100 MHz-3 GHz at 22 degrees C, in the surfactant concentration range 29.8-524 mM, explored for the first time above 104 mM. The micellar contribution to dielectric spectra was analyzed according to three models containing, respectively, a single Debye relaxation, a Cole-Cole relaxation and a double Debye relaxation. The single Debye model is not accurate enough. Both Cole-Cole and double Debye models fit well the experimental dielectric spectra. With the double Debye model, two characteristic relaxation times were identified: the slower one, in the range 400-900 ps, is due to the motion of counterions bound to the micellar surface (lateral motion); the faster one, in the range 100-130 ps, is due to interfacial bound water. Time constants and amplitudes of both processes are in fair agreement with Grosse's theoretical model, except at the largest concentration values, where interactions between micelles increase. For each sample, the volume fraction of bulk water and the effect of bound water as well as the conductivity in the low frequency limit were computed. The bound water increases as the surfactant concentration increases, in quantitative agreement with the micellar properties. The number of water molecules per surfactant molecule was also computed. The conductivity values are in agreement with Kallay's model over the whole surfactant concentration range.

Limits of linearity and detection for some drugs of abuse.

PubMed

Needleman, S B; Romberg, R W

1990-01-01

The limits of linearity (LOL) and detection (LOD) are important factors in establishing the reliability of an analytical procedure for accurately assaying drug concentrations in urine specimens. Multiple analyses of analyte over an extended range of concentrations provide a measure of the ability of the analytical procedure to correctly identify known quantities of drug in a biofluid matrix. Each of the seven drugs of abuse gives linear analytical responses from concentrations at or near their LOD to concentrations several-fold higher than those generally encountered in the drug screening laboratory. The upper LOL exceeds the Department of Navy (DON) cutoff values by factors of approximately 2 to 160. The LOD varies from 0.4 to 5.0% of the DON cutoff value for each drug. The limit of quantitation (LOQ) is calculated as the LOD + 7 SD. The range for LOL is greater for drugs analyzed with deuterated internal standards compared with those using conventional internal standards. For THC acid, cocaine, PCP, and morphine, LOLs are 8 to 160-fold greater than the defined cutoff concentrations. For the other drugs, the LOL's are only 2 to 4-fold greater than the defined cutoff concentrations.

Alcohol Dehydrogenase of Bacillus strain for Measuring Alcohol Electrochemically

NASA Astrophysics Data System (ADS)

Iswantini, D.; Nurhidayat, N.; Ferit, H.

2017-03-01

Alcohol dehydrogenase (ADH) was applied to produce alcohol biosensor. The enzyme was collected from cultured Bacillus sp. in solid media. From 6 tested isolates, bacteria from fermented rice grain (TST.A) showed the highest oxidation current which was further applied as the bioreceptor. Various ethanol concentrations was measured based on the increase of maximum oxidation current value. However, a reduction value was happened when the ethanol concentration was higher than 5%. Comparing the result of spectrophotometry measurement, R2 value obtained from the biosensor measurement method was higher. The new proposed method resulted a wider detection range, from 0.1-5% of ethanol concentration. The result showed that biosensor method has big potency to be used as alcohol detector in foods or bevearages.

[NT-proBNP as a diagnostic marker in dogs with dyspnea and in asymptomatic dogs with heart murmur].

PubMed

Haßdenteufel, E; Kresken, J-G; Henrich, E; Hildebrandt, N; Schneider, C; Stosic, A; Schneider, M

2012-01-01

The cardiac biomarker NT-proBNP indicates cardiac load in terms of myocardial wall stress. The objective of the study was to compare the results of NT-proBNP measurements in healthy dogs and dogs with dyspnea as well as asymptomatic dogs with heart murmur with the literature. Between April 2007 and December 2007 dogs with dyspnea of non-cardiac origin (n=11), dogs with dyspnea of cardiac origin (n=18) and asymptomatic dogs with heart murmur (n=22) were included. Twelve clinically healthy dogs served as a control group. All animals underwent cardiologic examination including echocardiography and measurement of serum NT-proBNP concentration. Serum was centrifuged and frozen within 30 minutes and was stored frozen until analysis was performed. Median NT-proBNP concentration in healthy dogs was 240 pmol/l (range 131-546 pmol/l). Dogs with dyspnea and primary respiratory disease displayed a median NT-proBNP concentration of 876 pmol/l (range 97-2614 pmol/l). In patients with dyspnea of non-cardiac origin, there was a difference in the values of NT-proBNP of dogs with and without pulmonary hypertension diagnosed by echocardiography. Dogs with dyspnea of cardiac origin displayed a median NT-proBNP concentration of 2000 pmol/l (range 137-2614 pmol/l). Low normal NT-proBNP values were only found in patients with pericardial effusion. Median NT-proBNP concentration in asymptomatic dogs with heart murmur was 698.5 pmol/l (range 121-2614 pmol/l). Considerably increased values were particularly measured in asymptomatic patients with severe congenital heart disease. NT-proBNP represents a useful additional diagnostic parameter in veterinary clinical cardiology to assess the severity of cardiac disease. Interpretation must take into consideration the clinical picture of the patient, as dogs with severe arrhythmias, sepsis and pulmonary thromboembolism may display high NT-proBNP levels without congestive heart failure. Our results indicate the following cut-off values: <500 pmol/l: no relevant cardiac load; 500-900 pmol/l: moderate cardiac load; >900 pmol/l: severe cardiac load.

Pharmacokinetic study of gallocatechin-7-gallate from Pithecellobium clypearia Benth. in rats.

PubMed

Li, Chao; Song, Xiaowei; Song, Junke; Pang, Xiaocong; Wang, Zhe; Zhao, Ying; Lian, Wenwen; Liu, Ailin; Du, Guanhua

2016-01-01

The pharmacokinetic profile of gallocatechin-7-gallate (J10688) was studied in rats after intravenous administration. Male and female Sprague-Dawley (SD) rats received 1, 3, and 10 mg/kg (i.v.) of J10688 and plasma drug concentrations were determined by a high performance liquid chromatography-mass spectrometry (LC-MS) method. The pharmacokinetic software Data Analysis System (Version 3.0) was used to calculate the pharmacokinetic parameters. For different i.v. doses of J10688, the mean peak plasma concentration (C 0) values ranged from 11.26 to 50.82 mg/L, and mean area under the concentration-time curve (AUC0-t ) values ranged from 1.75 to 11.80 (mg·h/L). J10688 lacked dose-dependent pharmacokinetic properties within doses between 1 and 10 mg/kg, based on the power model. The method developed in this study was sensitive, precise, and stable. The pharmacokinetic properties of J10688 in SD rats were shown to have rapid distribution and clearance values. These pharmacokinetic results may contribute to an improved understanding of the pharmacological actions of J10688.

Quantification of kinetic rate law parameters for the dissolution of natural autunite in the presence of aqueous bicarbonate ions at high concentrations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gudavalli, Ravi; Katsenovich, Yelena; Wellman, Dawn

Uranium is a key contaminant of concern in the groundwater at 91 waste sites at 18 U.S. Department of Energy (DOE) facilities within the United States and is a potential source of groundwater contamination and a risk to human health and the environment through discharges to surface water. Dissolved inorganic carbon (bicarbonate/carbonate) has a high affinity for complexing with uranium that is present as sorbed or unique uranium-bearing mineral phases within the sedimentary matrix. This process can result in the formation of soluble uranyl carbonate aqueous species, which are mobile under circumneutral pH conditions. This study was conducted to quantifymore » the rate of release of uranium from the autunite mineral, (Ca[(UO 2)(PO 4)] 2∙3H 2O), that was formed during polyphosphate injection to remediate uranium; the dissolution of uranium was studied as a function of the aqueous bicarbonate concentration, ranging from 25 to 100 mM. Experiments were carried out in the pH range from 7 to 11 in the temperature range of 23-90°C via single-pass flow-through testing. Consistent with the results of previous studies (Gudavalli et al., 2013 a, b), the rate of uranium release from autunite exhibited minimal dependency on temperature, but was strongly dependent on pH and increasing concentrations of bicarbonate in the solution. Data obtained during these experiments were compared with results of previous experiments conducted using a low-concentration range of bicarbonate solutions (0.5-3.0 mM). An 8- to 30 fold increase in the rate of uranium release was observed in the presence of high bicarbonate concentrations at pH 7-8 compared to low bicarbonate values, while at pH 9-11, there was only a 5-fold increase in uranium rate of release with an increase in bicarbonate concentrations. The rate of uranium release was calculated to be between 5.18 x 10 -8 and 1.69 x 10 -7 mol m -2 s -1. The activation energy values at high and low bicarbonate concentrations were similar, with ratio values in the range of 0.6-1.0.« less

Quantification of kinetic rate law parameters for the dissolution of natural autunite in the presence of aqueous bicarbonate ions at high concentrations.

PubMed

Gudavalli, Ravi; Katsenovich, Yelena; Wellman, Dawn

2018-05-02

Uranium is a key contaminant of concern in the groundwater at U.S. Department of Energy (DOE) facilities within the United States and is a potential source of groundwater contamination and a risk to human health and the environment through discharges to surface water. Dissolved inorganic carbon (bicarbonate/carbonate) has a high affinity for complexing with uranium that is present as sorbed or unique uranium-bearing mineral phases within the sedimentary matrix. This process can result in the formation of soluble uranyl carbonate aqueous species, which are mobile under circumneutral pH conditions. This study was conducted to quantify the rate of release of uranium from the autunite mineral, (Ca[(UO 2 )(PO 4 )] 2 •3H 2 O), that was formed during polyphosphate injection to remediate uranium; the dissolution of uranium was studied as a function of the aqueous bicarbonate concentration, ranging from 25 to 100 mM. Experiments were carried out in the pH range from 7 to 11 in the temperature range of 23-90 °C via single-pass flow-through testing. Consistent with the results of previous studies (Gudavalli et al., 2013a, 2013b), the rate of uranium release from autunite exhibited minimal dependency on temperature, but was strongly dependent on pH and increasing concentrations of bicarbonate in the solution. Data obtained during these experiments were compared with results of previous experiments conducted using a low-concentration range of bicarbonate solutions (0.5-3.0 mM). An 8- to 30-fold increase in the rate of uranium release was observed in the presence of high bicarbonate concentrations at pH 7-8 compared to low bicarbonate values, while at pH 9-11, there was only a 5-fold increase in uranium rate of release with an increase in bicarbonate concentrations. The rate of uranium release was calculated to be between 5.18 × 10 -8 and 1.69 × 10 -7  mol m -2 s -1 . The activation energy values at high and low bicarbonate concentrations were similar, with ratio values in the range of 0.6-1.0. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparative Study of Radon Concentration with Two Techniques and Elemental Analysis in Drinking Water Samples of the Jammu District, Jammu and Kashmir, India.

PubMed

Kumar, Ajay; Kaur, Manpreet; Mehra, Rohit; Sharma, Dinesh Kumar; Mishra, Rosaline

2017-10-01

The level of radon concentration has been assessed using the Advanced SMART RnDuo technique in 30 drinking water samples from Jammu district, Jammu and Kashmir, India. The water samples were collected from wells, hand pumps, submersible pumps, and stored waters. The randomly obtained 14 values of radon concentration in water sources using the SMART RnDuo technique have been compared and cross checked by a RAD7 device. A good positive correlation (R = 0.88) has been observed between the two techniques. The overall value of radon concentration in various water sources has ranged from 2.45 to 18.43 Bq L, with a mean value of 8.24 ± 4.04 Bq L, and it agreed well with the recommended limit suggested by the European Commission and UNSCEAR. However, the higher activity of mean radon concentration was found in groundwater drawn from well, hand and submersible pumps as compared to stored water. The total annual effective dose due to radon inhalation and ingestion ranged from 6.69 to 50.31 μSv y with a mean value of 22.48 ± 11.03 μSv y. The total annual effective dose was found to lie within the safe limit (100 μSv y) suggested by WHO. Heavy metal analysis was also carried out in various water sources by using an atomic absorption spectrophotometer (AAS), and the highest value of heavy metals was found mostly in groundwater samples. The obtained results were compared with Indian and International organizations like WHO and the EU Council. Among all the samples, the elemental analysis is not on the exceeding side of the permissible limit.

[Research on the mercury species in Jiaozhou Bay in spring].

PubMed

Xu, Liao-Qi; Liu, Ru-Hai; Wang, Jin-Yu; Tang, Ai-Kun; Wang, Shu

2012-01-01

In April 2010, seawater samples collected every twenty minutes in the Jiaozhou Bay were separated and determined in-situ and indoor to study mercury speciation and its daily variation and to further understand the end-result and effect of mercury on offshore environment. Results showed that dissolved element mercury (DEM) concentration of seawater ranged from 38.2 pg x L(-1) to 156 pg x L(-1), with an average value of 97.5 pg x L(-1). The highest and the lowest value appeared at around 13:00 and 17:30 respectively under the influence of tide and light intensity. DEM concentration gradually declined with depth. DEM of surface sea primarily derived from photoreduction of bivalent mercury. Dissolved mercury (DHg) concentrations ranged from 7.32 ng x L(-1) to 49.1 ng x L(-1) (average value was 13.9 ng x L(-1)), from 4.39 ng x L(-1) to 19.3 ng x L(-1) (average value was 7.94 ng x L(-1)) for dissolved reactive mercury (RHg). The maximum peaks of DHg and RHg all appeared around 13:00, due to dirty seawater carried by tidal movement in the lowest tide. The variation trend with depth of RHg and DHg concentrations was similar at different time. Under the influence of the light and water temperature, the ratio of RHg to DHg was higher in the surface water. RHg accounted for 62% of DHg, so the mercury had relatively high activity and biological availability, and contributed to the form of DEM. The methylmercury concentration was low, with an average value of 0.30 ng x L(-1), and some samples were lower than the detection limit.

Study on Enhancement Principle and Stabilization for the Luminol-H2O2-HRP Chemiluminescence System

PubMed Central

Yang, Lihua; Jin, Maojun; Du, Pengfei; Chen, Ge; Zhang, Chan; Wang, Jian; Jin, Fen; Shao, Hua; She, Yongxin; Wang, Shanshan; Zheng, Lufei; Wang, Jing

2015-01-01

A luminol-H2O2-HRP chemiluminescence system with high relative luminescent intensity (RLU) and long stabilization time was investigated. First, the comparative study on the enhancement effect of ten compounds as enhancers to the luminol-H2O2-HRP chemiluminescence system was carried out, and the results showed that 4-(imidazol-1-yl)phenol (4-IMP), 4-iodophenol (4-IOP), 4-bromophenol (4-BOP) and 4-hydroxy-4’-iodobiphenyl (HIOP) had the best performance. Based on the experiment, the four enhancers were dissolved in acetone, acetonitrile, methanol, and dimethylformamide (DMF) with various concentrations, the results indicated that 4-IMP, 4-IOP, 4-BOP and HIOP dissolved in DMF with the concentrations of 0.2%, 3.2%, 1.6% and 3.2% could get the highest RLU values. Subsequently, the influences of pH, ionic strength, HRP, 4-IMP, 4-IOP, 4-BOP, HIOP, H2O2 and luminol on the stabilization of the luminol-H2O2-HRP chemiluminescence system were studied, and we found that pH value, ionic strength, 4-IMP, 4-IOP, 4-BOP, HIOP, H2O2 and luminol have little influence on luminescent stabilization, while HRP has a great influence. In different ranges of HRP concentration, different enhancers should be selected. When the concentration is within the range of 0~6 ng/mL, 4-IMP should be selected. When the concentration of HRP ranges from 6 to 25ng/mL, 4-IOP was the best choice. And when the concentration is within the range of 25~80 ng/mL, HIOP should be selected as the enhancer. Finally, the three well-performing chemiluminescent enhanced solutions (CESs) have been further optimized according to the three enhancers (4-IMP, 4-IOP and HIOP) in their utilized HRP concentration ranges. PMID:26154162

Study on Enhancement Principle and Stabilization for the Luminol-H2O2-HRP Chemiluminescence System.

PubMed

Yang, Lihua; Jin, Maojun; Du, Pengfei; Chen, Ge; Zhang, Chan; Wang, Jian; Jin, Fen; Shao, Hua; She, Yongxin; Wang, Shanshan; Zheng, Lufei; Wang, Jing

2015-01-01

A luminol-H2O2-HRP chemiluminescence system with high relative luminescent intensity (RLU) and long stabilization time was investigated. First, the comparative study on the enhancement effect of ten compounds as enhancers to the luminol-H2O2-HRP chemiluminescence system was carried out, and the results showed that 4-(imidazol-1-yl)phenol (4-IMP), 4-iodophenol (4-IOP), 4-bromophenol (4-BOP) and 4-hydroxy-4'-iodobiphenyl (HIOP) had the best performance. Based on the experiment, the four enhancers were dissolved in acetone, acetonitrile, methanol, and dimethylformamide (DMF) with various concentrations, the results indicated that 4-IMP, 4-IOP, 4-BOP and HIOP dissolved in DMF with the concentrations of 0.2%, 3.2%, 1.6% and 3.2% could get the highest RLU values. Subsequently, the influences of pH, ionic strength, HRP, 4-IMP, 4-IOP, 4-BOP, HIOP, H2O2 and luminol on the stabilization of the luminol-H2O2-HRP chemiluminescence system were studied, and we found that pH value, ionic strength, 4-IMP, 4-IOP, 4-BOP, HIOP, H2O2 and luminol have little influence on luminescent stabilization, while HRP has a great influence. In different ranges of HRP concentration, different enhancers should be selected. When the concentration is within the range of 0~6 ng/mL, 4-IMP should be selected. When the concentration of HRP ranges from 6 to 25 ng/mL, 4-IOP was the best choice. And when the concentration is within the range of 25~80 ng/mL, HIOP should be selected as the enhancer. Finally, the three well-performing chemiluminescent enhanced solutions (CESs) have been further optimized according to the three enhancers (4-IMP, 4-IOP and HIOP) in their utilized HRP concentration ranges.

High arsenic concentrations and enriched sulfur and oxygen isotopes in a fractured-bedrock ground-water system

USGS Publications Warehouse

Lipfert, G.; Sidle, W.C.; Reeve, A.S.; Ayuso, R.A.; Boyce, A.J.

2007-01-01

Ground water with high arsenic concentrations (up to 26.6????mol L- 1) has sulfate enriched in 34S and 18O in the fractured-bedrock, ground-water system of the Kelly's Cove watershed, Northport, Maine, USA. The ranges of sulfur and oxygen isotope values in aqueous sulfate, ??34S[SO4] and ??18O[SO4], at the Kelly's Cove watershed are + 3.4 to + 4.9??? and - 2.0 to + 6.7???, respectively. These isotope values are strikingly similar to those of the Goose River, Maine watershed which has ??34S[SO4] and ??18O[SO4] ranges of + 3.7 to + 4.6 ??? and - 2.6 to + 7.5???, respectively. In both systems, high arsenic concentrations occur with high ??34S[SO4] and ??18O[SO4] values, yet redox conditions and underlying rock types are quite different. The isotope values of sulfide minerals, ??34S[min], from four bedrock cores vary over short distances and range from - 5.1 to + 7.5???. The ??34S[SO4] values are controlled by the ??34S[min] values with minor input of atmospheric SO4. The much narrower range in ??34S[SO4] values than ??34S[min] values is probably due to sufficient ground-water mixing at a scale greater than the ??34S[min] variability. The ??34S[SO4] values are about 2??? higher than the average ??34S[min] value and fall within the range of ??34S[min] values, indicating only minor fractionation due to bacterial reduction of SO4. The highest ??18O[SO4] values were measured in the downgradient, confined, arsenic-rich ground water. High ??18O[SO4] values there cannot be due to aeration by atmospheric oxygen, but may arise from reoxidation of reduced SO4 products. The enrichment factors of ??18O in SO4 compared to H2O, + 7.2 to + 15.5???, in the Kelly's Cove ground water and the negligible 34S enrichment is very similar to those derived from experimental data of anaerobic sulfide oxidation in the presence of Mn and Fe oxides. Sea level at the Kelly's Cove watershed was approximately 80??m above present sea level about 13 000??years before present, imposing reducing conditions on that area of the watershed. Sea level dropped approximately 60??m below present sea level about 11 000??years before present, allowing for possible oxidation of sulfide minerals and precipitation of arsenic in ferric oxyhydroxides during aeration of the ground-water system. Under present redox conditions, there is evidence that bacteria reduction of ferric oxyhydroxides releases arsenic. The fractionation of 18O in the SO4 during anaerobic oxidation of sulfide in the presence of Mn and Fe oxides and subsequent release of arsenic during Mn and Fe oxide reduction may explain the relationship between high arsenic concentrations and elevated 18O[SO4] at Kelly's Cove. ?? 2007 Elsevier B.V. All rights reserved.

Determination of a wide range of volatile organic compounds in ambient air using multisorbent adsorption/thermal desorption and gas chromatography/mass spectrometry

USGS Publications Warehouse

Pankow, J.F.; Luo, W.; Isabelle, L.M.; Bender, D.A.; Baker, R.J.

1998-01-01

Adsorption/thermal desorption with multisorbent air-sampling cartridges was developed for the determination of 87 method analytes including halogenated alkanes, halogenated alkenes, ethers, alcohols, nitriles, esters, ketones, aromatics, a disulfide, and a furan. The volatilities of the compounds ranged from that of dichlorofluoromethane (CFC12) to that of 1,2,3- trichlorobenzene. The eight most volatile compounds were determined using a 1.5-L air sample and a sample cartridge containing 50 mg of Carbotrap B and 280 mg of Carboxen 1000; the remaining 79 compounds were determined using a 5-L air sample and a cartridge containing 180 mg of Carbotrap B and 70 mg of Carboxen 1000. Analysis and detection were by gas chromatography/mass spectrometry. The minimum detectable level (MDL) concentration values ranged from 0.01 parts per billion by volume (ppbv) for chlorobenzene to 0.4 ppbv for bromomethane; most of the MDL values were in the range 0.02-0.06 ppbv. No breakthrough was detected with the prescribed sample volumes. Analyte stability on the cartridges was very good. Excellent recoveries were obtained with independent check standards. Travel spike recoveries ranged from 90 to 110% for 72 of the 87 compounds. The recoveries were less than 70% for bromomethane and chloroethene and for a few compounds such as methyl acetate that are subject to losses by hydrolysis; the lowest travel spike recovery was obtained for bromomethane (62%). Blank values for all compounds were either below detection or very low. Ambient atmospheric sampling was conducted in New Jersey from April to December, 1997. Three sites characterized by low, moderate, and high densities of urbanization/traffic were sampled. The median detected concentrations of the compounds were either similar at all three sites (as with the chlorofluorocarbon compounds) or increased with the density of urbanization/traffic (as with dichloromethane, MTBE, benzene, and toluene). For toluene, the median detected concentrations were 0.23, 0.42, and 0.70 ppbv at the three sites. Analytical precision was measured using duplicate sampling. As expected, the precision deteriorated with decreasing concentration. At concentrations greater than 0.2 ppbv, most duplicates differed by less than 20%; below the MDL values, the differences between the duplicates were larger, but they were still typically less than 40%.

Application of the [3H]Leucine Incorporation Technique for Quantification of Bacterial Secondary Production Associated with Decaying Wetland Plant Litter

PubMed Central

Gillies, Jane E.; Kuehn, Kevin A.; Francoeur, Steven N.; Neely, Robert K.

2006-01-01

The radiolabeled leucine incorporation technique for quantifying rates of bacterial production has increased in popularity since its original description for bacterioplankton communities. Prior studies addressing incorporation conditions (e.g., substrate saturation) for bacterial communities in other habitats, such as decaying plant litter, have reported a wide range of final leucine concentrations (400 nM to 50 μM) required to achieve saturation-level uptake. We assessed the application of the [3H]leucine incorporation procedure for measuring bacterial production on decaying wetland plant litter. Substrate saturation experiments (nine concentrations, 10 nM to 50 μM final leucine concentration) were conducted on three dates for microbial communities colonizing the submerged litter of three emergent plant species (Typha angustifolia, Schoenoplectus validus, and Phragmites australis). A modified [3H]leucine protocol was developed by coupling previously described incubation and alkaline extraction protocols with microdialysis (500 molecular weight cutoff membrane) of the final radiolabeled protein extract. The incorporation of [3H]leucine into protein exhibited a biphasic saturation curve, with lower apparent Km values ranging from 400 nM to 4.2 μM depending on the plant species studied. Upper apparent Km values ranged from 1.3 to 59 μM. These results suggest differential uptake by litter-associated microbial assemblages, with the lower apparent Km values possibly representing bacterial uptake and higher apparent Km values representing a combination of both bacterial and nonbacterial (e.g., eukaryotic) uptake. PMID:16957215

Free amino nitrogen concentration correlates to total yeast assimilable nitrogen concentration in apple juice.

PubMed

Boudreau, Thomas F; Peck, Gregory M; O'Keefe, Sean F; Stewart, Amanda C

2018-01-01

Yeast assimilable nitrogen (YAN) is essential for yeast growth and metabolism during apple ( Malus x domestica Borkh.) cider fermentation. YAN concentration and composition can impact cider fermentation kinetics and the formation of volatile aroma compounds by yeast. The YAN concentration and composition of apples grown in Virginia, USA over the course of two seasons was determined through analysis of both free amino nitrogen (FAN) and ammonium ion concentration. FAN was the largest fraction of YAN, with a mean value of 51 mg N L -1 FAN compared to 9 mg N L -1 ammonium. Observed YAN values ranged from nine to 249 mg N L -1 , with a mean value of 59 mg N L -1 . Ninety-four percent of all samples analyzed in this study contained <140 mg N L -1 YAN, a concentration generally considered the minimum level needed in grape-based wines for yeast to fully utilize all of the fermentable sugars. FAN concentration was correlated with total YAN concentration, but ammonium concentration was not. Likewise, there was no correlation between FAN and ammonium concentration.

Total and Bioaccessible Soil Arsenic and Lead Levels and Plant Uptake in Three Urban Community Gardens in Puerto Rico.

PubMed

Misenheimer, John; Nelson, Clay; Huertas, Evelyn; Medina-Vera, Myriam; Prevatte, Alex; Bradham, Karen

2018-01-01

Arsenic (As) and lead (Pb) are two contaminants of concern associated with urban gardening. In Puerto Rico, data currently is limited on As and Pb levels in urban garden soils, soil metal (loid) bioaccessibility, and uptake of As and Pb in soil by edible plants grown in the region. This study examined total and bioaccessible soil As and Pb concentrations and accumulation in 10 commonly grown garden plants collected from three urban community gardens in Puerto Rico. Bioavailability values were predicted using bioaccessibility data to compare site-specific bioavailability estimates to commonly used default exposure assumptions. Total and bioaccessible As levels in study soils ranged from 2 to 55 mg/kg and 1 to 18 mg/kg, respectively. Total and bioaccessible Pb levels ranged from 19 to 172 mg/kg and 17 to 97 mg/kg, respectively. Measured bioaccessibility values corresponded to 19 to 42% bioaccessible As and 61 to 100% bioaccessible Pb when expressed as a percent of total As and Pb respectively. Predicted relative percent bioavailability of soil As and Pb based on measured bioaccessibility values ranged from 18 to 36% and 51 to 85% for As and Pb respectively. Transfer factors (TFs) measuring uptake of As in plants from soil ranged from 0 to 0.073 in the edible flesh (fruit or vegetable) of plant tissues analyzed and 0.073 to 0.444 in edible leaves. Pb TFs ranged from 0.002 to 0.012 in flesh and 0.023 to 0.204 in leaves. Consistent with TF values, leaves accumulated higher concentrations of As and Pb than the flesh, with the highest tissue concentrations observed in the culantro leaf (3.2 mg/kg dw of As and 8.9 mg/kg dw of Pb). Leaves showed a general but not statistically-significant (α = 0.05) trend of increased As and Pb concentration with increased soil levels, while no trend was observed for flesh tissues. These findings provide critical data that can improve accuracy and reduce uncertainty when conducting site-specific risk determination of potential As and Pb exposure while gardening or consuming garden produce in the understudied region of Puerto Rico.

Experimental study of iron-chloride complexing in hydrothermal fluids

USGS Publications Warehouse

Fein, J.B.; Hemley, J.J.; d'Angelo, W. M.; Komninou, A.; Sverjensky, D.A.

1992-01-01

Mineral assemblage solubilities were measured in cold-seal pressure vessels as a function of pressure, temperature, and potassium chloride concentration in order to determine the nature and thermodynamic properties of iron-chloride complexes under hydrothermal conditions. The assemblage pyritepyrrhotite-magnetite was used to buffer f{hook}S2 and f{hook}O2, and K+ H+ ratios were buffered at reasonable geologic values using the assemblage potassium feldspar-muscovite (or andalusite)-quartz. The pressure-temperature ranges were 0.5-2.0 kbar and 300-600??C, and initial fluid compositions ranged from 0.01-2.0 molal KCl. With all other factors constant, the concentration of iron in solution increases with increasing temperature, with decreasing pressure, and with increasing total potassium chloride concentration. Changes in iron concentrations as a function of KCl concentration, in conjunction with charge balance, mass action, and mass balance constraints on the system, place constraints on the stoichiometry of the important iron-chloride complexes under each of the experimental conditions. Using least-squared linear regression fits to determine these slopes, the calculations yield values for the average ligand numbers that are in the range 1.2-1.9, with uncertainties ranging from ??0.1-0.6 at the several PT conditions considered. The slopes of the regressed fits to the data suggest that both FeCl+ and FeCl20 are important in the experimental fluids, with FeCl20 becoming dominant at the higher temperatures. Theoretical calculations, however, indicate that FeCl+ does not contribute significantly to the solubility. Because of the large uncertainties associated with some of the calculated average ligand numbers, we base our data analysis on the theoretical calculations. A statistical analysis is applied to the solubility data in order to determine the values and uncertainties of the dissociation constant for FeCl20 that best fit the data at each of the experimental pressures and temperatures. The calculated stability of FeCl20 increases with increasing temperature and total chloride concentration, and with decreasing pressure. The values of the dissociation constant of FeCl20that are calculated in this study are in moderately good agreement with FeCl20dissociation constants from other studies of iron-chloride complexing in supercritical fluids. Differences are likely due to different assumptions made concerning activity coefficients of aqueous species. Log kd values for full dissociation of FeCl20 at 0.5 kbar-300??C-and at 1 kbar-400, 500, and 600??C, respectively-are -3.75 ?? 0.40, -6.25 ?? 0.10, -9.19 ?? 0.44, and -13.29 ?? 0.09. ?? 1992.

Rapid and high-precision measurement of sulfur isotope and sulfur concentration in sediment pore water by multi-collector inductively coupled plasma mass spectrometry.

PubMed

Bian, Xiao-Peng; Yang, Tao; Lin, An-Jun; Jiang, Shao-Yong

2015-01-01

We have developed a technique for the rapid, precise and accurate determination of sulfur isotopes (δ(34)S) by MC-ICP-MS applicable to a range of sulfur-bearing solutions of different sulfur content. The 10 ppm Alfa-S solution (ammonium sulfate solution, working standard of the lab of the authors) was used to bracket other Alfa-S solutions of different concentrations and the measured δ(34)SV-CDT values of Alfa-S solutions deviate from the reference value to varying degrees (concentration effect). The stability of concentration effect has been verified and a correction curve has been constructed based on Alfa-S solutions to correct measured δ(34)SV-CDT values. The curve has been applied to AS solutions (dissolved ammonium sulfate from the lab of the authors) and pore water samples successfully, validating the reliability of our analytical method. This method also enables us to measure the sulfur concentration simultaneously when analyzing the sulfur isotope composition. There is a strong linear correlation (R(2)>0.999) between the sulfur concentrations and the intensity ratios of samples and the standard. We have constructed a regression curve based on Alfa-S solutions and this curve has been successfully used to determine sulfur concentrations of AS solutions and pore water samples. The analytical technique presented here enable rapid, precise and accurate S isotope measurement for a wide range of sulfur-bearing solutions - in particular for pore water samples with complex matrix and varying sulfur concentrations. Also, simultaneous measurement of sulfur concentrations is available. Copyright © 2014 Elsevier B.V. All rights reserved.

A recent history of metal accumulation in the sediments of Rijeka harbor, Adriatic Sea, Croatia.

PubMed

Cukrov, Neven; Frančišković-Bilinski, Stanislav; Hlača, Bojan; Barišić, Delko

2011-01-01

We studied metal pollution in the sediments of Rijeka harbor, including anthropogenic influence during recent decades and at the present time. Sediment profiles were collected at ten sampling points. The concentrations of 63 elements in bulk sediment were obtained using ICP-MS, and the concentrations of selected elements were evaluated by statistical factor analyses. We also calculated metal-enrichment factors and geoaccumulation indices and constructed spatial-distribution maps. Mercury (Hg) was the heaviest pollutant, with concentrations exceeding 4 mg/kg. Silver (Ag) was the second most important pollutant, with constantly increasing values. The average concentrations of the most toxic elements were comparable to those found in sediments of other ports throughout the world, and their toxicity ranged from threshold values [chromium (Cr), arsenic (As)] and midrange-effect values [cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn), nickel (Ni)] to extreme-effect values (Hg). Metal pollution has decreased during recent decades, except for Ag and barium (Ba). Copyright © 2010 Elsevier Ltd. All rights reserved.

Effects of agricultural practices and vadose zone stratigraphy on nitrate concentration in ground water in Kansas, USA

USGS Publications Warehouse

Townsend, M.A.; Sleezer, R.O.; Macko, S.A.; ,

1996-01-01

Differences in nitrate-N concentrations in,around water in Kansas can be explained by variations in agricultural practices and vadose-zone stratigraphy. In northwestern Kansas, past use of a local stream for tailwater runoff from irrigation and high fertilizer applications for sugar-beet farming resulted in high nitrate-N concentrations (12-60 mg L-1; in both soil and ground water. Nitrogen isotope values from the soil and ground water range from +4 to +8? which is typical for a fertilizer source. In parts of south-central Kansas, the use of crop rotation and the presence of both continuous fine-textured layers and a reducing ground-water chemistry resulted in ground-water nitrate-N values of 10 mg L-1; in both soil and grounwater. Nitrogen isotope values of +3 to +7? indicate a fertilizer source. Crop rotation decreased nitrate-N values in the shallow ground water (9 m). However, deeper ground water showed increasing nitrate-N concentrations as a result of past farming practices.

Silicon isotope fractionation in rice and cucumber plants over a life cycle: Laboratory studies at different external silicon concentrations

NASA Astrophysics Data System (ADS)

Sun, Yan; Wu, Lianghuan; Li, Xiaoyan; Sun, Li; Gao, Jianfei; Ding, Tiping

2016-11-01

Understanding the variations of silicon isotopes in terrestrial higher plants can be helpful toward elucidating the global biogeochemical silicon cycle. We studied silicon isotope fractionation in rice and cucumber plants over their entire life cycles. These two different silicon-absorbing plants were grown hydroponically at different external silicon concentrations. The ranges of δ30Si values in rice were -1.89‰ to 1.69‰, -1.81‰ to 1.96‰, and -2.08‰ to 2.02‰ at 0.17 mM, 1.70 mM, and 8.50 mM silicon concentrations, respectively. The ranges of δ30Si values in cucumber were -1.38‰ to 1.21‰, -1.33‰ to 1.26‰, and -1.62‰ to 1.40‰ at 0.085 mM, 0.17 mM, and 1.70 mM external silicon concentrations, respectively. A general increasing trend in δ30Si values from lower to upper plant parts reflected the preferential incorporation of lighter silicon isotopes from transpired water to biogenic opal. Furthermore, the active uptake mechanism regulated by several transporters might have also played an important role in the preferential transport of heavy silicon isotopes into aboveground plant parts. This suggested that silicon isotope fractionation in both rice and cucumber was a Rayleigh-like process. The data on δ30Si values for the whole plants and nutrient solutions indicated that biologically mediated silicon isotope fractionation occurred during silicon uptake by roots. At lower external silicon concentrations, heavy silicon isotopes entered plants more readily than light silicon isotopes. Conversely, at higher external silicon concentrations, light silicon isotopes entered plants more readily than heavy silicon isotopes.

Stability of urea in solution and pharmaceutical preparations.

PubMed

Panyachariwat, Nattakan; Steckel, Hartwig

2014-01-01

The stability of urea in solution and pharmaceutical preparations was analyzed as a function of temperature (25°-60°C), pH (3.11-9.67), and initial urea concentration (2.5%-20%). This study was undertaken to (i) obtain more extensive, quantitative information relative to the degradation of urea in both aqueous and non-aqueous solutions and in pharmaceutical preparations, and (ii) test the effects of initial urea concentration, pH, buffer, and temperature values on urea degradation. The stability analysis shows that urea is more stable at the pH range of 4-8 and the stability of urea decreases by increase in temperature for all pH values. Within the experimental range of temperature and initial urea concentration values, the lowest urea degradation was found with lactate buffer pH 6.0. The urea decomposition rate in solution and pharmaceutical preparations shows the dependence of the initial urea concentrations. At higher initial urea concentrations, the rate of degradation is a decreasing function with time. This suggests that the reverse reaction is a factor in the degradation of concentrated urea solution. For non-aqueous solvents, isopropanol showed the best effort in retarding the decomposition of urea. Since the losses in urea is directly influenced by its stability at a given temperature and pH, the stability analysis of urea by the proposed model can be used to prevent the loss and optimize the operating condition for urea-containing pharmaceutical preparations.

Uranium hydrogeochemical and stream sediment reconnaissance of the Durango NTMS quadrangle, Colorado

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dawson, H.E.; Weaver, T.A.

1979-01-01

During the spring and summer of 1976, 1518 water and 1604 waterborne sediment samples were collected from 1804 locations in the Durango NTMS quadrangle, Colorado. The samples obtained from this 19 940-km/sup 2/ area were analyzed at the Los Alamos Scientific Laboratory for total uranium. The uranium concentrations in waters ranged from less than the detectable limit of 0.2 ppB to 25.7 ppB, with a mean value of 0.84 ppB. The concentrations in sediments ranged from 1.0 ppM to 71.6 ppM, with a mean value of 4.2 ppM. Study of total water and total sediment populations indicated that both aremore » actually mixtures of several populations. Consequently, samples were chosen for discussion on the basis of their having conspicuously high uranium concentrations relative to surrounding background values. Thirty-four water samples (approximately 2.2% of the total water population) had uranium concentrations above 5.00 ppB, the highest of which were well water samples from the San Luis Valley. Thirty-seven sediment samples (approximately 2.3% of the total sediment population) had uranium concentrations above 12.0 ppM. The majority of these were taken from sites in Precambrian rocks, but several came from Paleozoic and Mesozoic strate and Tertiary volcanics. The uranium concentrations in sediment samples from areas of Precambrian rock were especially high and these areas may warrant further, more detailed investigations.« less

Kinetic analysis of Legionella inactivation using ozone in wastewater.

PubMed

Li, Jun; Li, Kunquan; Zhou, Yan; Li, Xuebin; Tao, Tao

2017-02-01

Legionella inactivation using ozone was studied in wastewater using kinetic analysis and modeling. The experimental results indicate that the relationship between the ozone concentration, germ concentration, and chemical oxygen demand (COD) can be used to predict variations in germ and COD concentrations. The ozone reaction with COD and inactivation of Legionella occurred simultaneously, but the reaction with COD likely occurred at a higher rate than the inactivation, as COD is more easily oxidized by ozone than Legionella. Higher initial COD concentrations resulted in a lower inactivation rate and higher lnN/N 0 . Higher temperature led to a higher inactivation efficiency. The relationship of the initial O 3 concentration and Legionella inactivation rate was not linear, and thus, the Ct value required for a 99.99% reduction was not constant. The initial O 3 concentration was more important than the contact time, and a reduction of the initial O 3 concentration could not be compensated by increasing the contact time. The Ct values were compared over a narrow range of initial concentrations; the Ct values could only be contrasted when the initial O 3 concentrations were very similar. A higher initial O 3 concentration led to a higher inflection point value for the lnN/N 0 vs C 0 t curve. Energy consumption using a plasma corona was lower than when using boron-doped diamond electrodes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of Salinity on Leaf Spectral Reflectance and Biochemical Parameters of Nitrogen Fixing Soybean Plants (Glycine max L.)

NASA Astrophysics Data System (ADS)

Krezhova, Dora D.; Kirova, Elisaveta B.; Yanev, Tony K.; Iliev, Ilko Ts.

2010-01-01

Measurements of physiology and hyperspectral leaf reflectance were used to detect salinity stress in nitrogen fixing soybean plants. Seedlings were inoculated with suspension of Bradyrhizobium japonicum strain 273. Salinity was performed at the stage of 2nd-4th trifoliate expanded leaves by adding of NaCl in the nutrient solution of Helrigel in concentrations 40 mM and 80 mM. A comparative analysis was performed between the changes in the biochemical parameters - stress markers (phenols, proline, malondialdehyde, thiol groups), chlorophyll a and b, hydrogen peroxide, and leaf spectral reflectance in the spectral range 450-850 nm. The spectral measurements were carried out by an USB2000 spectrometer. The reflectance data of the control and treated plants in the red, green, red-edge and the near infrared ranges of the spectrum were subjected to statistical analysis. Statistically significant differences were found through the Student's t-criterion at the two NaCl concentrations in all of the ranges examined with the exception of the near infrared range at 40 mM NaCl concentration. Similar results were obtained through linear discriminant analysis. The tents of the phenols, malondialdehyde and chlorophyll a and b were found to decrease at both salinity treatments. In the spectral data this effect is manifested by decrease of the reflectance values in the green and red ranges. The contents of proline, hydrogen peroxide and thiol groups rose with the NaCl concentration increase. At 80 mM NaCl concentration the values of these markers showed a considerable increase giving evidence that the soybean plants were stressed in comparison with the control. This finding is in agreement with the results from the spectral reflectance analysis.

Helium concentrations in soil gas of the Ely and Delta 1 degree x 2 degrees quadrangles. Basin and Range Province

USGS Publications Warehouse

Reimer, G.M.; Bowles, C.G.

1983-01-01

A reconnaissance soil-gas helium survey was made of the Ely, Nevada and Delta, Utah 1? x 2? quadrangles in the Basin and Range Province. Helium concentrations in 510 samples ranged from -147 to 441 ppb He with respect to ambient air. The median helium value for the study area was 36 ppb. Concentrations of more than 100 ppb He, and less than -20 ppb He, occur more commonly in the Ely Quadrangle and are especially numerous in the western one-half of this quadrangle. The data are presented both in figures and tables, and some of the geologic factors that may affect the helium distribution are discussed.

Groundwater Quality Assessment in the Upper East Region of Ghana

NASA Astrophysics Data System (ADS)

Apambire, W. B.

2001-05-01

In Ghana, West Africa, fluoride occurs as a natural pollutant in some groundwaters, while the presence of isolated high levels of nitrate and arsenic in groundwater is due to human activities such as poor sanitation, garbage disposal and mining practices. The challenge for Ghana is to ensure that groundwater quality and environmental adversities such as water level decline are not compromised by attempts to increase water quantity. Concentrations of groundwater fluoride in the study area range from 0.11 to 4.60 mg/L, with the highest concentrations found in the fluorine-enriched Bongo granitoids. Eighty-five out of 400 wells sampled have fluoride concentrations above the World Health Organization maximum guideline value of 1.5 mg/L and thus causes dental fluorosis in children drinking from the wells. The distribution of fluoride in groundwater is highly related to the distribution of dental fluorosis in the UER. Nitrate concentrations ranged from 0.03 to 211.00 mg/L and the mean value was 16.11 mg/L. Twenty-one samples had concentrations in excess of the guideline value of 45 mg/L. Consumption of water in excess of the guideline value, by infants, may cause an infantile disease known as methaemoglobinaemia. It is inferred that groundwaters with exceptionally high NO3 values have been contaminated principally through human activities such as farming and waste disposal. This is because wells with high nitrate concentrations are all located in and around towns and sizable villages. Also, there is good correlation between Cl and NO3 (r = +0.74), suggesting that both elements come from the same sources of pollution. Only two well waters had concentrations of iron in excess of the guideline value of 0.3 mg/L. These samples come from shallow hand-dug wells. The maximum concentration of iron in groundwaters is 3.5 mg/L. The recommended guideline limit for Al in drinking water is 0.2 mg/L; two wells had Al concentrations of 12.0 and 4.0 mg/L, respectively. Other high concentrations of Al are associated with shallow wells and ponds. There is a highly positive correlation (r = +1) between Fe and Al, suggesting that dissolution of weathered lateritic material (e.g., Fe oxides, gibbsite, etc.) is the common source for these elements. Manganese concentrations are generally within acceptable limits, except for 11 wells that have concentrations above the guideline limit of 0.1 mg/L. These anomalous concentrations may be associated with manganiferous deposits in the study area. A majority of the samples contain very low concentrations of the trace elements Zn, Pb, Cd, Cr, As and Se; however, the highest concentrations occur in areas where small-scale mining is practiced.

Human exposure to metals: levels in autopsy tissues of individuals living near a hazardous waste incinerator.

PubMed

Mari, Montse; Nadal, Martí; Schuhmacher, Marta; Barbería, Eneko; García, Francisco; Domingo, José L

2014-06-01

The concentrations of a number of metals were determined in the brain, bone, kidney, liver, and lung of 20 autopsied subjects who had lived, at least 10 years, in the neighborhood of a hazardous waste incinerator (HWI) in Tarragona (Catalonia, Spain). Results were compared with those obtained in 1998 (baseline survey) and previous surveys (2003 and 2007). Arsenic, Be, Ni, Tl, and V showed concentrations below the corresponding detection limits in all tissues. Cadmium showed the highest levels in the kidney, with a mean value of 21.15 μg/g. However, Cd was found below the detection limit in the brain and bone. Chromium showed similar concentrations in the kidney, brain, and lung (range of mean values, 0.57-0.66 μg/g) and higher in the bone (1.38 μg/g). In turn, Hg was below the detection limit in all tissues with the exception of the kidney, where the mean concentration was 0.15 μg/g (range, <0.05-0.58 μg/g). On the other hand, Mn could be detected in all tissues showing the highest levels in the liver and kidney (1.45 and 1.09 μg/g, respectively). Moreover, Pb showed the highest concentrations in bone (mean, 1.39 μg/g; range, <0.025-4.88 μg/g). Finally, Sn could be detected only in some tissue samples, reaching the highest values in the bone (0.17 μg/g). The current metal levels in human tissues from individuals living near the HWI of Tarragona are comparable and of a similar magnitude to previously reported results corresponding to general populations, as well as those of our previous surveys.

Dissipation and distribution of chlorpyrifos in selected vegetables through foliage and root uptake.

PubMed

Ge, Jing; Lu, Mengxiao; Wang, Donglan; Zhang, Zhiyong; Liu, Xianjin; Yu, Xiangyang

2016-02-01

Dissipation, distribution and uptake pathways of chlorpyrifos were investigated in pakchoi (Brassica chinensis L.) and lettuce (Lactuca sativa) with foliage treatments under a greenhouse trial and root treatments under a hydroponic experiment. The dissipation trends were similar for chlorpyrifos in pakchoi and lettuce with different treatments. More than 94% of chlorpyrifos was degraded in the samples for both of the vegetables 21 days after the foliage treatments. For the root treatment, the dissipation rate of chlorpyrifos in pakchoi and lettuce at the low concentration was greater than 93%, however, for the high concentrations, the dissipation rates were all under 90%. Both shoots and roots of the vegetables were able to absorb chlorpyrifos from the environment and distribute it inside the plants. Root concentration factor (RCF) values at different concentrations with the hydroponic experiment ranged from 5 to 39 for pakchoi, and from 14 to 35 for lettuce. The translocation factor (TF) representing the capability of the vegetables to translocate contaminants was significantly different for pakchoi and lettuce with foliage and root treatments. The values of TF with foliage treatments ranged from 0.003 to 0.22 for pakchoi, and from 0.032 to 1.63 for lettuce. The values of TF with root treatments ranged from 0.01 to 0.17 for pakchoi, and from 0.003 to 0.23 for lettuce. Significant difference of TF was found between pakchoi and lettuce with foliage treatments, and at high concentrations (10 and 50 mg L(-1)) with root treatments as well. However, there was no significant difference of TF between pakchoi and lettuce at 1 mg L(-1) with root treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Estimating the Capacity Value of Concentrating Solar Power Plants With Thermal Energy Storage: A Case Study of the Southwestern United States

DOE PAGES

Madaeni, Seyed Hossein; Sioshansi, Ramteen; Denholm, Paul

2012-08-13

We estimate the capacity value of concentrating solar power (CSP) plants with thermal energy storage (TES) in the southwestern U.S. Our results show that incorporating TES in CSP plants significantly increases their capacity value. While CSP plants without TES have capacity values ranging between 60% and 86% of maximum capacity, plants with TES can have capacity values between 79% and 92%. Here, we demonstrate the effect of location and configuration on the operation and capacity value of CSP plants. Finally, we also show that using a capacity payment mechanism can increase the capacity value of CSP, since the capacity valuemore » of CSP is highly sensitive to operational decisions and energy prices are not a perfect indicator of scarcity of supply.« less

Inner filter effect and the onset of concentration dependent red shift of synchronous fluorescence spectra.

PubMed

Tarai, Madhumita; Mishra, Ashok Kumar

2016-10-12

The phenomenon of concentration dependent red shift, often observed in synchronous fluorescence spectra (SFS) of monofluorophoric as well as multifluorophoric systems at high chromophore concentrations, is known to have good analytical advantages. This was previously understood in terms of large inner filter effect (IFE) through the introduction of a derived absorption spectral profile that closely corresponds to the SFS profile. Using representative monofluorophoric and multifluorophoric systems, it is now explained how the SF spectral maximum changes with concentration of the fluorophore. For dilute solutions of monofluorophores the maximum is unchanged as expected. It is shown here that the onset of red shift of SFS maximum of both the mono as well as the multifluorophoric systems must occur at the derived absorption spectral parameter value of 0.32 that corresponds to the absorbance value of 0.87. This value is unique irrespective of the nature of the fluorophore under study. For monofluorophoric systems, the wavelength of derived absorption spectral maximum and the wavelength of synchronous fluorescence spectral maximum closely correspond with each other in the entire concentration range. In contrast, for multifluorophoric systems like diesel and aqueous humic acid, large deviations were noted that could be explained as to be due to the presence of non-fluorescing chromophores in the system. This work bridges the entire fluorophore concentration range over which the red shift of SFS maximum sets in; and in the process it establishes the importance of the derived absorption spectral parameter in understanding the phenomenon of concentration dependent red shift of SFS maximum. Copyright © 2016 Elsevier B.V. All rights reserved.

Validation of the bispectral index as an indicator of anesthetic depth in Thoroughbred horses anesthetized with sevoflurane

PubMed Central

TOKUSHIGE, Hirotaka; KAKIZAKI, Masashi; ODE, Hirotaka; OKANO, Atsushi; OKADA, Jun; KURODA, Taisuke; WAKUNO, Ai; OHTA, Minoru

2016-01-01

ABSTRACT To evaluate the bispectral index (BIS) as an indicator of anesthetic depth in Thoroughbred horses, BIS values were measured at multiple stages of sevoflurane anesthesia in five horses anesthetized with guaifenesin and thiopental following premedication with xylazine. There was no significant difference between the BIS values recorded at end-tidal sevoflurane concentrations of 2.8% (median 60 ranging from 47 to 68) and 3.5% (median 71 ranging from 49 to 82) in anesthetized horses. These BIS values during anesthesia were significantly lower (P<0.01) than those in awake horses (median 98 ranging from 98 to 98) or sedated horses (median 92 ranging from 80 to 93). During the recovery phase, the BIS values gradually increased over time but did not significantly increase until the horses showed movement. In conclusion, the BIS value could be useful as an indicator of awakening during the recovery period in horses, as previous reported. PMID:27974877

D/H and Water Concentrations of Submarine MORB Glass Around the World: Analytical Aspects, Standardization, and (re)defining Mantle D/H Ranges

NASA Astrophysics Data System (ADS)

Bindeman, I. N.; Dixon, J. E.; Langmuir, C. H.; Palandri, J. L.

2015-12-01

The advent and calibration of the Thermal Combustion Element Analyzer (TCEA) continuous flow system coupled with the large-radius mass spectrometer MAT253 permits precise (±0.02 wt.% H2O, ±1-3‰ D/H) measurements in 1-10 mg of volcanic glass (0.1 wt.% H2O requires ~10 mg glass), which permits the targeting of small amounts of the freshest concentrate. This is a >100 factor reduction in sample size over conventional methods, four times over more common Delta series instruments. We investigated in triplicate 115 samples of submarine MORB glasses ranging from water-poor (0.1-0.2wt%) to water-rich (1.2-1.5wt%). These samples were previously investigated for major and trace elements, radiogenic isotopes; a large subset of these samples coming from the FAZAR expedition were studied previously by FTIR for water concentration. We also ran samples previously studied by the conventional off-line technique: MORB glass including those from the Easter Platform and the Alvin 526-1 standard (0.2wt% H2O). We observe excellent 1:1 correspondence (1.02x+0.02, R2=0.94) of wt% water by FTIR and TCEA suggesting complete extraction of water and no dependence on water concentration. We measure 51‰ total range in D/H that correlates with all other chemical and isotopic indicators of mantle enrichment, with the heaviest values occurring in the most enriched samples. When used uncorrected values of H2 gas run against H2 gas of known composition, this range agrees nicely with previous D/H range for MORB (-30 to -90‰), measured for samples run conventionally. Uncorrected analyses of Alvin glass 526-1 gives -66‰. When run against SMOW, SLAP and -41‰ water sealed in silver cups, the range is shifted by -15‰; when standardization is done by with three commonly used mica standards as is done most commonly in different labs, the range is shifted downward by -30-32‰. There are no isotopic offsets related to total water or D/H range requiring different slope or non-linear correction. The NBS30 mica standard has been recently shown to be heavier and more heterogeneous than previously thought, and older conventional methods that relied on Pt reduction unreliable. Based on these new TCEA results, the D/H values of MORB and mantle samples may need to be revised to lighter values by 15‰.

Petrology, mineralogy and geochemistry of mined coals, western Venezuela

USGS Publications Warehouse

Hackley, Paul C.; Warwick, Peter D.; González, Eligio

2005-01-01

Upper Paleocene to middle Miocene coal samples collected from active mines in the western Venezuelan States of Táchira, Mérida and Zulia have been characterized through an integrated geochemical, mineralogical and petrographic investigation. Proximate, ultimate, calorific and forms of sulfur values, major and trace element, vitrinite reflectance, maceral concentrations and mineral matter content have been determined for 16 channel samples from 14 mines. Ash yield generally is low, ranging from < 1 to 17 wt.% (mean = 5 wt.%) on a dry basis (db). Total sulfur content is low to moderate, ranging from 1 to 6 wt.%, db (average = 1.7 wt.%). Calorific value ranges from 25.21 to 37.21 MJ/kg (10,840–16,000 Btu/lb) on a moist, mineral-matter-free basis (average = 33.25 MJ/kg, 14,300 Btu/lb), placing most of the coal samples in the apparent rank classification of high-volatile bituminous. Most of the coal samples exhibit favorable characteristics on the various indices developed to predict combustion and coking behavior and concentrations of possible environmentally sensitive elements (As, Be, Cd, Cr, Co, Hg, Mn, Ni, Pb, Sb, Se, Th and U) generally are similar to the concentrations of these elements in most coals of the world, with one or two exceptions. Concentrations of the liptinite maceral group range from < 1% to 70 vol.%. Five samples contain > 20 vol.% liptinite, dominated by the macerals bituminite and sporinite. Collotelinite dominates the vitrinite group; telinite was observed in quantities of ≤ 1 vol.% despite efforts to better quantify this maceral by etching the sample pellets in potassium permanganate and also by exposure in an oxygen plasma chamber. Inertinite group macerals typically represent < 10 vol.% of the coal samples and the highest concentrations of inertinite macerals are found in distantly spaced (> 400 km) upper Paleocene coal samples from opposite sides of Lago de Maracaibo, possibly indicating tectonic controls on subsidence related to construction of the Andean orogen. Values of maximum reflectance of vitrinite in oil (Ro max) range between 0.42% and 0.85% and generally are consistent with the high-volatile bituminous rank classification obtained through ASTM methods. X-ray diffraction analyses of low-temperature ash residues indicate that kaolinite, quartz, illite and pyrite dominate the inorganic fraction of most samples; plagioclase, potassium feldspar, calcite, siderite, ankerite, marcasite, rutile, anatase and apatite are present in minor or trace concentrations. Semiquantitative values of volume percent pyrite content show a strong correlation with pyritic sulfur and some sulfide-hosted trace element concentrations (As and Hg). This work provides a modern quality dataset for the western Venezuela coal deposits currently being exploited and will serve as the foundation for an ongoing coal quality research program in Venezuela.

Stability of nitrate-ion concentrations in simulated deposition samples used for quality-assurance activities by the U.S. Geological Survey

USGS Publications Warehouse

Willoughby, T.C.; See, R.B.; Schroder, L.J.

1989-01-01

Three experiments were conducted to determine the stability of nitrate-ion concentrations in simulated deposition samples. In the four experiment-A solutions, nitric acid provided nitrate-ion concentrations ranging from 0.6 to 10.0 mg/L and that had pH values ranging from 3.8 to 5.0. In the five experiment-B solutions, sodium nitrate provided nitrate-ion concentrations ranging from 0.5 to 3.0 mg/L. The pH was adjusted to about 4.5 for each of the solutions by addition of sulfuric acid. In the four experiment-C solutions, nitric acid provided nitrate-ion concentrations ranging from 0.5 to 3.0 mg/L. Major cation and anion concentrations were added to each solution to simulate natural deposition. Aliquots were removed from the 13 original solutions and analyzed by ion chromatography about once a week for 100 days to determine if any changes occurred in nitrate-ion concentrations throughout the study period. No substantial changes were observed in the nitrate-ion concentrations in solutions that had initial concentrations below 4.0 mg/L in experiments A and B, although most of the measured nitrate-ion concentrations for the 100-day study were below the initial concentrations. In experiment C, changes in nitrate-ion concentrations were much more pronounced; the measured nitrate-ion concentrations for the study period were less than the initial concentrations for 62 of the 67 analyses. (USGS)

[Chromophoric dissolved organic matter absorption characteristics with relation to fluorescence in typical macrophyte, algae lake zones of Lake Taihu].

PubMed

Zhang, Yun-lin; Qin, Bo-qiang; Ma, Rong-hua; Zhu, Guang-wei; Zhang, Lu; Chen, Wei-min

2005-03-01

Chromophoric dissolved organic matter (CDOM) represents one of the primary light-absorbing species in natural waters and plays a critical in determining the aquatic light field. CDOM shows a featureless absorption spectrum that increases exponentially with decreasing wavelength, which limits the penetration of biologically damaging UV-B radiation (wavelength from 280 to 320 nm) in the water column, thus shielding aquatic organisms. CDOM absorption measurements and their relationship with dissolved organic carbon (DOC), and fluorescence are presented in typical macrophyte and algae lake zone of Lake Taihu based on a field investigation in April in 2004 and lab analysis. Absorption spectral of CDOM was measured from 240 to 800 nm using a Shimadzu UV-2401PC UV-Vis recording spectrophotometer. Fluorescence with an excitation wavelength of 355 nm, an emission wavelength of 450 nm is measured using a Shimadzu 5301 spectrofluorometer. Concentrations of DOC ranged from 6.3 to 17.2 mg/L with an average of 9.08 +/- 2.66 mg/L. CDOM absorption coefficients at 280 nm and 355 nm were in the range of 11.2 - 32.6 m(-1) (average 17.46m(-1) +/- 5.75 m(-1) and 2.4 - 8.3 m(-1) (average 4.17m(-1) +/- 1.47 m(-l)), respectively. The values of the DOC-specific absorption coefficient at 355 nm ranged from 0.31 to 0.64 L x (mg x m)-1. Fluorescence emission at 450 nm, excited at 355 nm, had a mean value of 1.32nm(-1) +/- 0.84 nm(-1). A significant lake zone difference is found in DOC concentration, CDOM absorption coefficient and fluorescence, but not in DOC-specific absorption coefficient and spectral slope coefficient. This regional distribution pattern is in agreement with the location of sources of yellow substance: highest concentrations close to river mouth under the influence of river inflow, lower values in East Lake Taihu. The values of algae lake zone are obvious larger than those of macrophyte lake zone. In Meiliang Bay, CDOM absorption, DOC concentration and fluorescence tend to decreasing from inside to mouth of the Bay. The results show a good correlation between CDOM absorption and DOC coefficients during 280 - 500 nm short wavelength intervals. The R-square coefficient between CDOM absorption and DOC concentration decreases with the increase of wavelength from 280 to 500 nm. The significant linear regression correlations between fluorescence, DOC concentration and absorption coefficients were found at 355 nm. The exponential slope coefficients ranged from 13.0 to 16.4 microm(-1) with a mean value 14.37microm(-1) +/- 0.73microm(-1), 17.3microm(-1) - 20.3microm(-1) with a mean value 19.17microm(-1) +/- 0.84microm(-1) and 12.0microm(-1) - 15.8microm(-1) with a mean value 13.38microm(-1) +/- 0.82microm(-1) over the 280 - 500 nm, 280 - 360 nm and 360 - 440 nm intervals.

Influence of nitromethane concentration on ignition energy and explosion parameters in gaseous nitromethane/air mixtures.

PubMed

Zhang, Qi; Li, Wei; Lin, Da-Chao; He, Ning; Duan, Yun

2011-01-30

The aim of this paper is to provide new experimental data of the minimum ignition energy (MIE) of gaseous nitromethane/air mixtures to discuss the explosion pressure and the flame temperature as a function of nitromethane concentration. Observations on the influence of nitromethane concentration on combustion pressure and temperature through the pressure and temperature measure system show that peak temperature (the peak of combustion temperature wave) is always behind peak pressure (the peak of the combustion pressure wave) in arrival time, the peak combustion pressure of nitromethane increases in the range of its volume fraction 10-40% as the concentration of nitromethane increases, and it slightly decreases in the range of 40-50%. The maximum peak pressure is equal to 0.94 MPa and the minimum peak pressure 0.58 MPa. Somewhat similar to the peak pressure, the peak combustion temperature increases with the volume fraction of nitromethane in the range of 10-40%, and slightly decreases in 40-50%. The maximum peak temperature is 1340 °C and the minimum 860 °C. The combustion temperature rise rate increases with the concentration of nitromethane in 10-30%, while decreases in 30-50% and its maximum value of combustion temperature rise rate in 10-50% is 4200 °C/s at the volume fraction of 30%. Influence of the concentration of nitromethane on the combustion pressure rise rate is relatively complicated, and the maximum value of rise rate of combustion pressure wave in 10-50% is 11 MPa/s at the concentration 20%. Copyright © 2010 Elsevier B.V. All rights reserved.

Analysis of Tank 38H (HTF-38-16-80, 81) and Tank 43H (HTF-43-16-82, 83) Samples for Support of the Enrichment Control and Corrosion Control Programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hay, M.

2016-10-24

SRNL analyzed samples from Tank 38H and Tank 43H to support ECP and CCP. The total uranium in the Tank 38H surface sample was 57.6 mg/L, while the sub-surface sample was 106 mg/L. The Tank 43H samples ranged from 50.0 to 51.9 mg/L total uranium. The U-235 percentage was consistent for all four samples at 0.62%. The total uranium and percent U-235 results appear consistent with recent Tank 38H and Tank 43H uranium measurements. The Tank 38H plutonium results show a large difference between the surface and sub-surface sample concentrations and somewhat higher concentrations than previous samples. The Pu-238 concentrationmore » is more than forty times higher in the Tank 38H sub-surface sample than the surface sample. The surface and sub-surface Tank 43H samples contain similar plutonium concentrations and are within the range of values measured on previous samples. The four samples analyzed show silicon concentrations somewhat higher than the previous sample with values ranging from 104 to 213 mg/L.« less

Tributyltin distribution and producing androgenic activity in water, sediment, and fish muscle.

PubMed

Shue, Meei-Fang; Chen, Ting-Chien; Bellotindos, Luzvisminda M; Lu, Ming-Chun

2014-01-01

This study investigated the concentrations of Tributyltin (TBT) in water, sediment, and fish muscle samples taken from Kaohsiung Harbor and Kaoping River estuary, Taiwan. TBT concentrations in water and sediment samples ranged from less than 18.5 to 34.1 ng Sn L(-1) and from 2.44 to 29.7 ng Sn g(-1) weight per weight (w/w), respectively. Concentrations in the TBT-contaminated fish muscle samples ranged from 10.8 to 79.6 ng Sn g(-1) w/w. The TBT concentrations in fish muscle were higher than those in water and sediment samples. The fish muscle/water TBT bioconcentration factor (BCF) ranged from 590 to 3363 L kg(-1). Additionally, the water samples were assessed for androgenic activity with an MCF7-AR1 human breast cancer cell line. The androgenic activity ranged from 0.94 to 3.1 ng-dihydrotestosterone per litre water (ng-DHT L(-1)). Higher concentrations of TBT in water and sediment samples occurred in the dry season, but the androgenic activity had higher values in the rainy season.

Sulfur isotope and porewater geochemistry of Florida escarpment seep sediments

USGS Publications Warehouse

Chanton, J.P.; Martens, C.S.; Paull, C.K.; Coston, J.A.

1993-01-01

Distributions of porewater constituents, SO4=, NH4+, Cl-, ???CO2, and H2S, solid phase iron, and sulfur concentrations, and the sulfur isotopic composition of dissolved and solid phases were investigated in sediments from abyssal seeps at the base of the Florida escarpment. Despite the apparent similarity of seep sediment porewater chemistry to that of typical marine sediments undergoing early diagenesis, relationships between chemical distributions and isotopic measurements revealed that the distribution of pore fluid constituents was dominated by processes occurring within the platform rather than by in situ microbial processes. Ammonium and sulfate concentrations were linearly correlated with chloride concentrations, indicating that variations in porewater chemistry were controlled by the admixture of seawater and a sulfate depleted brine with a chlorinity of 27.5 ?? 1.9%. and 2.2 ?? 1.3 mM ammonium concentration. At sites dominated by seepage, dissolved sulfate isotopic composition remained near seawater values despite depletion in porewater concentrations. Porewater ???CO2 concentrations were found to be elevated relative to seawater, but not to the extent predicted from the observed sulfate depletion. Sediment solid phase sulfur was predominantly pyrite, at concentrations as high as 20% S by weight. In contrast to typical marine deposits, pyrite concentrations were not related to the quantity of sedimentary organic matter. Pyrite ??34S values ranged from -29%. to + 21%. (CDT). However, only positive ??34S values were observed at sites associated with high pyrite concentrations. Isotopically heavy pyrite was observed at sites with porewater sulfate of seawater-like isotopic composition. Isotopically light pyrite was associated with sites where porewater sulfate exhibited ??34S values greater than those in seawater, indicating the activity of in situ microbial sulfate reduction. Thus, dual sulfide sources are suggested to explain the range in sediment pyrite isotopic composition: a ??34S enriched (+10 to +20%.) source adverted from within the Florida platform, and a lighter 34S depleted component generated in situ from microbial reduction of seawater sulfate. The degree of pyritization of seep sediments was as high as 0.9 and was controlled by pyrite concentrations, which varied over a wider range than did the non-pyrite solid phase iron concentrations. The highest non-sulfide solid phase iron concentrations were observed in sediments that are believed to be at the "front" of the advancing seep fluids (i.e., hemipelagic sediments newly exposed to the seep fluids), indicating that dissolution of hemipelagic background sediment may be the source of at least half of the iron to the highly pyritized seep sediments. Porewater sulfide concentrations were variable, reaching a maximum of 5.7 mM, and were not correlated with the degree of pyritization of the sediments, suggesting that iron was not particularly limiting to pyrite formation. ?? 1993.

Nucleation of actin polymerization by gelsolin.

PubMed

Ditsch, A; Wegner, A

1994-08-15

The time-course of assembly of actin with gelsolin was measured by the fluorescence increase of a fluorescent label covalently linked to actin. The actin concentrations ranged from values far below the critical concentration to values above the critical concentration of the pointed ends of actin filaments. If the concentration of actin was in the range of the critical monomer concentration (0.64 microM), the time-course of the concentration of actin assembled with gelsolin revealed a sigmoidal shape. At higher actin concentrations the time-course of association of actin with gelsolin approximated an exponential curve. The measured time-courses of assembly were quantitatively interpreted by kinetic rate equations. A poor fit was obtained if two actin molecules were assumed to bind to gelsolin to form a 1:2 gelsolin-actin complex and subsequently further actin molecules were assumed to polymerize onto the 1:2 gelsolin-actin complex toward the pointed end. A considerably better agreement between calculated and measured time-courses was achieved if additional creation of actin filaments by fast fragmentation of newly formed actin filaments by not yet consumed gelsolin was assumed to occur. This suggests that both polymerization of actin onto gelsolin and fragmentation of actin filaments contribute to formation of new actin filaments by gelsolin. Furthermore it could be demonstrated that below the critical monomer concentration appreciable amounts of actin are incorporated into gelsolin-actin oligomers.

40 CFR 258.53 - Ground-water sampling and analysis requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... considering the number of samples in the background data base, the data distribution, and the range of the... the background data base, the data distribution, and the range of the concentration values for each... samples collected to establish ground-water quality data must be consistent with the appropriate...

40 CFR 258.53 - Ground-water sampling and analysis requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... considering the number of samples in the background data base, the data distribution, and the range of the... the background data base, the data distribution, and the range of the concentration values for each... samples collected to establish ground-water quality data must be consistent with the appropriate...

Trihalomethanes in Lisbon indoor swimming pools: occurrence, determining factors, and health risk classification.

PubMed

Silva, Zelinda Isabel; Rebelo, Maria Helena; Silva, Manuela Manso; Alves, Ana Martins; Cabral, Maria da Conceição; Almeida, Ana Cristina; Aguiar, Fátima Rôxo; de Oliveira, Anabela Lopes; Nogueira, Ana Cruz; Pinhal, Hermínia Rodrigues; Aguiar, Pedro Manuel; Cardoso, Ana Sofia

2012-01-01

Characterization of water quality from indoor swimming pools, using chorine-based disinfection techniques, was performed during a 6-mo period to study the occurrence, distribution, and concentration factors of trihalomethanes (THM). Several parameters such as levels of water THM, water and air chloroform, water bromodichloromethane (BDCM), water dibromochloromethane (DBCM), water bromoform (BF), free residual chlorine (FrCl), pH, water and air temperature, and permanganate water oxidizability (PWO) were determined in each pool during that period. Chloroform (CF(W)) was the THM detected at higher concentrations in all pools, followed by BDCM, DBCM, and BF detected at 99, 34, and 6% of the samples, respectively. Water THM concentrations ranged from 10.1 to 155 μg/L, with 6.5% of the samples presenting values above 100 μg/L (parametric value established in Portuguese law DL 306/2007). In this study, air chloroform (CF(Air)) concentrations ranged from 45 to 373 μg/m³ with 24% of the samples presenting values above 136 μg/m³ (considered high exposure value). Several significant correlations were observed between total THM and other parameters, namely, CF(W), CF(Air), FrCl, water temperature (T(W)), and PWO. These correlations indicate that FrCl, T(W) and PWO are parameters that influence THM formation. The exposure criterion established for water THM enabled the inclusion of 67% of Lisbon pools in the high exposure group, which reinforces the need for an improvement in pool water quality.

Determining CDOM Absorption Spectra in Diverse Coastal Environments Using a Multiple Pathlength, Liquid Core Waveguide System. Measuring the Absorption of CDOM in the Field Using a Multiple Pathlength Liquid Waveguide System

NASA Technical Reports Server (NTRS)

Miller, Richard L.; Belz, Mathias; DelCastillo, Carlos; Trzaska, Rick

2000-01-01

We evaluated the accuracy, sensitivity and precision of a multiple pathlength, liquid core waveguide (MPLCW) system for measuring colored dissolved organic matter (CDOM) absorption in the UV-visible spectral range (370-700 nm). The MPLCW has four optical paths (2.0, 9.8, 49.3, and 204 cm) coupled to a single Teflon AF sample cell. Water samples were obtained from inland, coastal and ocean waters ranging in salinity from 0 to 36 PSU. Reference solutions for the MPLCW were made having a refractive index of the sample. CDOM absorption coefficients, a(sub CDOM), and the slope of the log-linearized absorption spectra, S, were compared with values obtained using a dual-beam spectrophotometer. Absorption of phenol red secondary standards measured by the MPLCW at 558 nm were highly correlated with spectrophotometer values (r > 0.99) and showed a linear response across all four pathlengths. Values of a(sub CDOM) measured using the MPLCW were virtually identical to spectrophotometer values over a wide range of concentrations. The dynamic range of a(sub CDOM) for MPLCW measurements was 0.002 - 231.5/m. At low CDOM concentrations (a(sub 370) < 0.1/m) spectrophotometric a(sub CDOM) were slightly greater than MPLCW values and showed larger fluctuations at longer wavelengths due to limitations in instrument precision. In contrast, MPLCW spectra followed an exponential to 600 nm for all samples. The maximum deviation in replicate MPLCW spectra was less than 0.001 absorbance units. The portability, sampling, and optical characteristics of a MPLCW system provide significant enhancements for routine CDOM absorption measurements in a broad range of natural waters.

Distributions and seasonal variations of dissolved carbohydrates in the Jiaozhou Bay, China

NASA Astrophysics Data System (ADS)

Yang, Gui-Peng; Zhang, Yan-Ping; Lu, Xiao-Lan; Ding, Hai-Bing

2010-06-01

Surface seawater samples were collected in the Jiaozhou Bay, a typical semi-closed basin located at the western part of the Shandong Peninsula, China, during four cruises. Concentrations of monosaccharides (MCHO), polysaccharides (PCHO) and total dissolved carbohydrates (TCHO) were measured with the 2,4,6-tripyridyl- s-triazine spectroscopic method. Concentrations of TCHO varied from 10.8 to 276.1 μM C for all samples and the ratios of TCHO to dissolved organic carbon (DOC) ranged from 1.1 to 67.9% with an average of 10.1%. This result indicated that dissolved carbohydrates were an important constituent of DOC in the surface seawater of the Jiaozhou Bay. In all samples, the concentrations of MCHO ranged from 2.9 to 65.9 μM C, comprising 46.1 ± 16.6% of TCHO on average, while PCHO ranged from 0.3 to 210.2 μM C, comprising 53.9 ± 16.6% of TCHO on average. As a major part of dissolved carbohydrates, the concentrations of PCHO were higher than those of MCHO. MCHO and PCHO accumulated in January and July, with minimum average concentration in April. The seasonal variation in the ratios of TCHO to DOC was related to water temperature, with high values in January and low values in July and October. The concentrations of dissolved carbohydrates displayed a decreasing trend from the coastal to the central areas. Negative correlations between concentrations of TCHO and salinity in July suggested that riverine input around the Jiaozhou Bay had an important effect on the concentrations of dissolved carbohydrates in surface seawater. The pattern of distributions of MCHO and PCHO reported in this study added to the global picture of dissolved carbohydrates distribution.

Characterizing the concentration of Cryptosporidium in Australian surface waters for setting health-based targets for drinking water treatment.

PubMed

Petterson, S; Roser, D; Deere, D

2015-09-01

It is proposed that the next revision of the Australian Drinking Water Guidelines will include 'health-based targets', where the required level of potable water treatment quantitatively relates to the magnitude of source water pathogen concentrations. To quantify likely Cryptosporidium concentrations in southern Australian surface source waters, the databases for 25 metropolitan water supplies with good historical records, representing a range of catchment sizes, land use and climatic regions were mined. The distributions and uncertainty intervals for Cryptosporidium concentrations were characterized for each site. Then, treatment targets were quantified applying the framework recommended in the World Health Organization Guidelines for Drinking-Water Quality 2011. Based on total oocyst concentrations, and not factoring in genotype or physiological state information as it relates to infectivity for humans, the best estimates of the required level of treatment, expressed as log10 reduction values, ranged among the study sites from 1.4 to 6.1 log10. Challenges associated with relying on historical monitoring data for defining drinking water treatment requirements were identified. In addition, the importance of quantitative microbial risk assessment input assumptions on the quantified treatment targets was investigated, highlighting the need for selection of locally appropriate values.

Comparison of the acetyl bromide spectrophotometric method with other analytical lignin methods for determining lignin concentration in forage samples.

PubMed

Fukushima, Romualdo S; Hatfield, Ronald D

2004-06-16

Present analytical methods to quantify lignin in herbaceous plants are not totally satisfactory. A spectrophotometric method, acetyl bromide soluble lignin (ABSL), has been employed to determine lignin concentration in a range of plant materials. In this work, lignin extracted with acidic dioxane was used to develop standard curves and to calculate the derived linear regression equation (slope equals absorptivity value or extinction coefficient) for determining the lignin concentration of respective cell wall samples. This procedure yielded lignin values that were different from those obtained with Klason lignin, acid detergent acid insoluble lignin, or permanganate lignin procedures. Correlations with in vitro dry matter or cell wall digestibility of samples were highest with data from the spectrophotometric technique. The ABSL method employing as standard lignin extracted with acidic dioxane has the potential to be employed as an analytical method to determine lignin concentration in a range of forage materials. It may be useful in developing a quick and easy method to predict in vitro digestibility on the basis of the total lignin content of a sample.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chitra Sivaraman, PNNL

Cloud droplet number concentration is an important factor in understanding aerosol-cloud interactions. As aerosol concentration increases, it is expected that droplet number concentration (Nd) will increase and droplet size will decrease, for a given liquid water path. This will greatly affect cloud albedo as smaller droplets reflect more shortwave radiation; however, the magnitude and variability of these processes under different environmental conditions is still uncertain.McComiskey et al. (2009) have implemented a method, based onBoers and Mitchell (1994), for calculating Nd from ground-based remote sensing measurements of optical depth and liquid water path. They show that the magnitude of the aerosol-cloudmore » interactions (ACI) varies with a range of factors, including the relative value of the cloud liquid water path (LWP), the aerosol size distribution, and the cloud updraft velocity. Estimates of Nd under a range of cloud types and conditions and at a variety of sites are needed to further quantify the impacts of aerosol cloud interactions. In order to provide data sets for studying aerosol-cloud interactions, the McComiskey et al. (2009) method was implemented as the Droplet Number Concentration (NDROP) value-added product (VAP).« less

Seasonal Variation of Arsenic Concentration in Natural Water of the Source Area of the Yellow River on the Qinghai-Tibet Plateau, China

NASA Astrophysics Data System (ADS)

Yu, C.; Wen, L.; Yu, Z.

2017-12-01

Seasonal variation in the arsenic (As) concentration of natural water has been studied the first time in the source area of the Yellow River (SAYR) in Tibet, China. Samples were collected in the lake, river and spring across the whole area in April (spring) and July (summer), 2014. In April the average values of arsenic concentration in SAYR from high to low were: lake (38.1μg/L, n=47, range 8.6-131.0μg/L) > river (24.3μg/L, n=83, range 4.3-77.1μg/L) > spring (19.1μg/L, n=12, range 12.0-29.4μg/L). In July the same order of the average values of arsenic concentration in SAYR was found: lake (14.1μg/L, n=57, range 5.8-68.5μg/L) > river (7.3μg/L, n=106, range 3.6-22.9μg/L)> spring (6.7μg/L, n=9, range 4.8-8.2μg/L).The average arsenic concentrations in April were almost three times higher than those in July. In both season, the higher concentrations of arsenic were distributed in the upper reaches above the two biggest lakes of Gyaring and Ngoring Lakes in SAYR. The two big lakes buffered the naturally generated arsenic concentration in surface water, suggesting the important ecological role of the lakes. Generally, the lower concentrations in July probably were due to 1. the dilution effect of the precipitation; 2 the change of water sources. In April when the permafrost and mountain snow started to thaw and melt, ground water with high arsenic concentration was the main water source with high concentration of arsenic; but in July, with the increase of the temperature, mountain snow, permafrost would contribute more than in April, in addition, the main arsenic contributor groundwater was diluted by the precipitation recharge. Since in spring, lake and river water arsenic concentration decreased with almost the same magnitude., assuming the dilution effect dominant. The exported arsenic from SAYR in April (903.4Kg) were twice more than it in July (449.1Kg), because the flowrates were similar in the two months, the water source of the runoff components was grandly different in April and July. The seasonal variation of arsenic is obvious and further investigation is needed.

Plasma concentrations of fentanyl with subcutaneous infusion in palliative care patients.

PubMed

Miller, R S; Peterson, G M; Abbott, F; Maddocks, I; Parker, D; McLean, S

1995-12-01

1. Plasma concentrations of fentanyl were measured by g.c. in 20 patients (median age: 75 years and range: 54-86 years; eight females) in palliative care receiving the drug by continuous s.c. infusion (median rate: 1200 micrograms day-1 and range: 100-5000 micrograms day-1). 2. The infusion rate was significantly related to the duration of therapy (Spearman rho = 0.56, P < 0.05). The total steady-state plasma concentrations of fentanyl ranged between 0.1 and 9 ng ml-1, with a median of 1 ng ml-1. The unbound fraction of fentanyl in the plasma ranged from 17.8 to 44.4%, with a median value of 33.6%. Infusion rates and both total and unbound plasma concentrations of fentanyl were correlated (Spearman rho = 0.92, P < 0.05 in each case). Even with standardization for dosage, there was an eightfold variation in total plasma concentrations and 3.5-fold variation in unbound plasma concentrations of fentanyl. 3. There is considerable inter-patient variability in the pharmacokinetics of fentanyl with s.c. infusion in the palliative care setting, which necessitates careful titration of dosage according to individual clinical response.

Analysis of possible future atmospheric retention of fossil fuel CO/sub 2/

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edmonds, J.A.; Reilly, J.; Trabalka, J.R.

1984-09-01

This report investigates the likely rates and the potential range of future CO/sub 2/ emissions, combined with knowledge of the global cycle of carbon, to estimate a possible range of future atmospheric CO/sub 2/ concentrations through the year 2075. Historic fossil fuel usage to the present, growing at a rate of 4.5% per year until 1973 and at a slower rate of 1.9% after 1973, was combined with three scenarios of projected emissions growth ranging from approximately 0.2 to 2.8% per year to provide annual CO/sub 2/ emissions data for two different carbon cycle models. The emissions scenarios were constructedmore » using an energy-economic model and by varying key parameters within the bounds of currently expected future values. The extreme values for CO/sub 2/ emissions in the year 2075 are 6.8 x 10/sup 15/ and 91 x 10/sup 15/ g C year/sup -1/. Carbon cycle model simulations used a range of year - 1800 preindustrial atmospheric concentrations of 245 to 292 ppM CO/sub 2/ and three scenarios of bioshere conversion as additional atmospheric CO/sub 2/ source terms. These simulations yield a range of possible atmospheric CO/sub 2/ concentrations in year 2075 of approximately 500 to 1500 ppM, with a median of about 700 ppM. The time at which atmospheric CO/sub 2/ would potentially double from the preindustrial level ranges from year 2025 to >2075. The practical, programmatic value of this forecast exercise is that it forces quantitative definition of the assumptions, and the uncertainties therein, which form the basis of our understanding of the natural biogeochemical cycle of carbon and both historic and future human influences on the dynamics of the global cycle. Assumptions about the possible range of future atmospheric CO/sub 2/ levels provide a basis on which to evaluate the implications of these changes on climate and the biosphere. 44 references, 17 figures, 21 tables.« less

Dielectric and electrical study of PPy doped PVA-PVP films

NASA Astrophysics Data System (ADS)

Jha, Sushma; Tripathi, Deepti

2018-05-01

Dielectric parameters of free standing films of pure PVA (PolyvinylAlcohol) and PVA with varying concentrations of PVP(Polyvinylpyrrolidone) and Polypyrrole were prepared and studied in low frequency range (100Hz - 2MHz). The results show that dielectric constant, loss tangent and conductivity increase sharply on increasing the concentration of PVP above 50wt% in polymer matrix. PVA-PVP film with low concentration of PPy showed improvement in the values of complex permittivity, loss tangent and ac conductivity within the experimental frequency range. This eco - friendly polymeric material will be studied for its probable application for RFI/EMI shielding, biosensors, capacitors & insulation purposes.

Deep-water antipatharians: Proxies of environmental change

USGS Publications Warehouse

Williams, B.; Risk, Michael J.; Ross, Steve W.; Sulak, K.J.

2006-01-01

Deep-water (307-697 m) antipatharian (black coral) specimens were collected from the southeastern continental slope of the United States and the north-central Gulf of Mexico. The sclerochronology of the specimens indicates that skeletal growth takes place by formation of concentric coeval layers. We used 210Pb to estimate radial growth rate of two specimens, and to establish that they were several centuries old. Bands were delaminated in KOH and analyzed for carbon and nitrogen stable isotopes. Carbon values ranged from -16.4??? to -15.7???; oldest specimen displayed the largest range in values. Nitrogen values ranged from 7.7??? to 8.6???. Two specimens from the same location and depth had similar 15N signatures, indicating good reproducibility between specimens. ?? 2006 Geological Society of America.

The diagnostic value of thyroglobulin concentration in fine-needle aspiration of the cervical lymph nodes in patients with differentiated thyroid cancer.

PubMed

Mikosiński, Sławomir; Pomorski, Lech; Oszukowska, Lidia; Makarewicz, Jacek; Adamczewski, Zbigniew; Sporny, Stanisław; Lewiński, Andrzej

2006-01-01

Recurrent differentiated thyroid cancer generally occurs first in the neck. Ultrasound is sensitive in detecting enlarged cervical lymph nodes but is not specific enough. Ultrasound-guided fine-needle biopsy increases the specificity but still may fail to detect a recurrence of the disease in the cystic metastatic lymph nodes. The aim of the study was to estimate the value of Tg concentration in the needle washout after fine-needle aspiration of suspicious lymph nodes. The 105 patients studied had presented one or more enlarged suspicious cervical lymph nodes. All had undergone total thyroidectomy and (131)I ablative therapy. Serum thyroglobulin (Tg) concentration was within the 0.15-711.5 ng/ml range (mean 22.24 ng/ml) and Tg recovery range 94-100%. The positive Tg washout concentration cut-off value was established as equal to the mean plus two standard deviations of the Tg washout concentration of patients with negative cytology. Lymph node involvement was diagnosed by cytology in 15 patients and in 28 lymph nodes. Positive Tg washout concentration was found in 22 patients and in 48 lymph nodes. All the lymph nodes which turned out to have positive cytology had a positive Tg washout concentration. All lymph nodes with positive cytology were positive in pathology. Seven patients and 20 lymph nodes with negative cytology were positive in the Tg washout concentration test. All but one patients and all but two lymph nodes with a positive Tg washout concentration had positive pathology. 1. Ultrasound-guided fine-needle biopsy is not sensitive enough to detect all metastatic lymph nodes. 2. The Tg washout concentration test is 100% sensitive in the detection of metastatic lymph nodes. 3. Cytology in ultrasound- guided fine-needle biopsy is 100% specific. 4. The Tg washout concentration test carries a risk of false-positive results. 5. Both methods should be used for early detection of metastatic lymph nodes in patients with differentiated thyroid cancer.

Concentration of gold in natural waters

USGS Publications Warehouse

McHugh, J.B.

1988-01-01

The purpose of this paper is to investigate the amount of gold present in natural waters. One hundred and thirty-two natural water samples were collected from various sources and analyzed for gold by the latest techniques. Background values for gold in natural waters range from <0.001 to 0.005 ppb, and anomalous values range from 0.010 to 2.8 ppb. Waters collected from mineralized areas have a mean gold value of 0.101 ppb, whereas waters collected from unmineralized areas have a mean of 0.002 ppb. Some of the high gold values reported in the earlier literature were probably due to interferences by high salt content in the sample and/or lack of proper filter procedures. ?? 1988.

Structures and interactions among globular proteins above the isoelectric point in the presence of divalent ions: A small angle neutron scattering and dynamic light scattering study

NASA Astrophysics Data System (ADS)

Kundu, Sarathi; Pandit, Subhankar; Abbas, Sohrab; Aswal, V. K.; Kohlbrecher, J.

2018-02-01

Small angle neutron scattering study reveals that at pD ≈ 7.0, above the isoelectric point of the globular protein Bovine Serum Albumin (BSA), in the presence of different divalent ions (Mg2+, Ca2+, Sr2+ and Ba2+), the short-range attractive interaction remains nearly constant and the intermediate-range repulsive interaction decreases with increasing salt concentration up to a certain concentration value but after that remains unchanged. However, for the monovalent ion (Na+), repulsive interaction decreases gradually up to 1 M salt concentration. Dynamic light scattering study shows that for all ions, diffusion coefficient of BSA decreases with increasing salt concentration and then nearly saturates.

Decreased lymphocyte responses in free-ranging bottlenose dolphins (Tursiops truncatus) are associated with increased concentrations of PCBs and DDT in peripheral blood.

PubMed Central

Lahvis, G P; Wells, R S; Kuehl, D W; Stewart, J L; Rhinehart, H L; Via, C S

1995-01-01

Since 1987, large-scale mortalities of dolphins have been reported along the Atlantic coast of North America, in the Gulf of Mexico, and in the Mediterranean Sea. Autopsied bottlenose dolphins, Tursiops truncatus, which were collected from the large-scale mortality along the Atlantic coast in 1987 to 1988, exhibited opportunistic infections indicative of immune dysfunction. Further, these animals had high levels of chlorinated hydrocarbons, such as PCBs and DDT, that can suppress immune functions. The purpose of this study was to determine whether there is a relationship between chemical contaminant exposure and immune response in free-ranging dolphins. In June of 1991, peripheral blood was obtained from members of a bottlenose dolphin population that resides along the west coast of Florida. Peripheral blood lymphocyte responses to Concanavalin A (Con A) and phytohemagglutinin (PHA) were determined in vitro and compared by regression analysis with contaminant concentrations in whole blood from a small subset of these animals (n = 5). These data indicate that a reduced immune response in these bottlenose dolphins was correlated with increasing whole blood concentrations of several contaminants. Specifically, inverse correlations were found between Con A-induced lymphocyte proliferation and tetrachlorinated to octachlorinated biphenyls (r2 values ranged from 0.70 to 0.87). Con A-induced lymphocyte responses also correlated inversely with p,p'DDT (r2 values of 0.73 and 0.79); o.p'-DDE (r2 values of 0.93 and 0.96); and p,p'-DDE (r2 values of 0.73 and 0.81). PMID:7556026

Long-term observations of cloud condensation nuclei in the Amazon rain forest – Part 1: Aerosol size distribution, hygroscopicity, and new model parametrizations for CCN prediction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pöhlker, Mira L.; Pöhlker, Christopher; Ditas, Florian

Size-resolved long-term measurements of atmospheric aerosol and cloud condensation nuclei (CCN) concentrations and hygroscopicity were conducted at the remote Amazon Tall Tower Observatory (ATTO) in the central Amazon Basin over a 1-year period and full seasonal cycle (March 2014–February 2015). Our measurements provide a climatology of CCN properties characteristic of a remote central Amazonian rain forest site.The CCN measurements were continuously cycled through 10 levels of supersaturation ( S=0.11 to 1.10 %) and span the aerosol particle size range from 20 to 245 nm. The mean critical diameters of CCN activation range from 43 nm at S = 1.10 % to 172more » nm at S = 0.11 %. Furthermore, the particle hygroscopicity exhibits a pronounced size dependence with lower values for the Aitken mode ( κ Ait = 0.14 ± 0.03), higher values for the accumulation mode ( κ Acc = 0.22 ± 0.05), and an overall mean value of κ mean = 0.17 ± 0.06, consistent with high fractions of organic aerosol.The hygroscopicity parameter, κ, exhibits remarkably little temporal variability: no pronounced diurnal cycles, only weak seasonal trends, and few short-term variations during long-range transport events. In contrast, the CCN number concentrations exhibit a pronounced seasonal cycle, tracking the pollution-related seasonality in total aerosol concentration. Here, we find that the variability in the CCN concentrations in the central Amazon is mostly driven by aerosol particle number concentration and size distribution, while variations in aerosol hygroscopicity and chemical composition matter only during a few episodes.For modeling purposes, we compare different approaches of predicting CCN number concentration and present a novel parametrization, which allows accurate CCN predictions based on a small set of input data.« less

Long-term observations of cloud condensation nuclei in the Amazon rain forest – Part 1: Aerosol size distribution, hygroscopicity, and new model parametrizations for CCN prediction

DOE PAGES

Pöhlker, Mira L.; Pöhlker, Christopher; Ditas, Florian; ...

2016-12-20

Size-resolved long-term measurements of atmospheric aerosol and cloud condensation nuclei (CCN) concentrations and hygroscopicity were conducted at the remote Amazon Tall Tower Observatory (ATTO) in the central Amazon Basin over a 1-year period and full seasonal cycle (March 2014–February 2015). Our measurements provide a climatology of CCN properties characteristic of a remote central Amazonian rain forest site.The CCN measurements were continuously cycled through 10 levels of supersaturation ( S=0.11 to 1.10 %) and span the aerosol particle size range from 20 to 245 nm. The mean critical diameters of CCN activation range from 43 nm at S = 1.10 % to 172more » nm at S = 0.11 %. Furthermore, the particle hygroscopicity exhibits a pronounced size dependence with lower values for the Aitken mode ( κ Ait = 0.14 ± 0.03), higher values for the accumulation mode ( κ Acc = 0.22 ± 0.05), and an overall mean value of κ mean = 0.17 ± 0.06, consistent with high fractions of organic aerosol.The hygroscopicity parameter, κ, exhibits remarkably little temporal variability: no pronounced diurnal cycles, only weak seasonal trends, and few short-term variations during long-range transport events. In contrast, the CCN number concentrations exhibit a pronounced seasonal cycle, tracking the pollution-related seasonality in total aerosol concentration. Here, we find that the variability in the CCN concentrations in the central Amazon is mostly driven by aerosol particle number concentration and size distribution, while variations in aerosol hygroscopicity and chemical composition matter only during a few episodes.For modeling purposes, we compare different approaches of predicting CCN number concentration and present a novel parametrization, which allows accurate CCN predictions based on a small set of input data.« less

Exposure assessment of radon in the drinking water supplies: a descriptive study in Palestine

PubMed Central

2012-01-01

Background Radon gas is considered as a main risk factor for lung cancer and found naturally in rock, soil, and water. The objective of this study was to determine the radon level in the drinking water sources in Nablus city in order to set up a sound policy on water management in Palestine. Methods This was a descriptive study carried out in two phases with a random sampling technique in the second phase. Primarily, samples were taken from 4 wells and 5 springs that supplied Nablus city residents. For each source, 3 samples were taken and each was analyzed in 4 cycles by RAD 7 device manufactured by Durridge Company. Secondly, from the seven regions of the Nablus city, three samples were taken from the residential tap water of each region. Regarding the old city, ten samples were taken. Finally, the mean radon concentration value for each source was calculated. Results The mean (range) concentration of radon in the main sources were 6.9 (1.5-23.4) Becquerel/liter (Bq/L). Separately, springs and wells' means were 4.6 Bq/L and 9.5 Bq/L; respectively. For the residential tap water in the 7 regions, the results of the mean (range) concentration values were found to be 1.0 (0.9-1.3) Bq/L. For the old city, the mean (range) concentration values were 2.3 (0.9-3.9) Bq/L. Conclusions Except for Al-Badan well, radon concentrations in the wells and springs were below the United State Environmental Protection Agency maximum contaminated level (U.S EPA MCL). The level was much lower for tap water. Although the concentration of radon in the tap water of old city were below the MCL, it was higher than other regions in the city. Preventive measures and population awareness on radon's exposure are recommended. PMID:22243625

Exposure assessment of radon in the drinking water supplies: a descriptive study in Palestine.

PubMed

Al Zabadi, Hamzeh; Musmar, Samar; Issa, Shaza; Dwaikat, Nidal; Saffarini, Ghassan

2012-01-13

Radon gas is considered as a main risk factor for lung cancer and found naturally in rock, soil, and water. The objective of this study was to determine the radon level in the drinking water sources in Nablus city in order to set up a sound policy on water management in Palestine. This was a descriptive study carried out in two phases with a random sampling technique in the second phase. Primarily, samples were taken from 4 wells and 5 springs that supplied Nablus city residents. For each source, 3 samples were taken and each was analyzed in 4 cycles by RAD 7 device manufactured by Durridge Company. Secondly, from the seven regions of the Nablus city, three samples were taken from the residential tap water of each region. Regarding the old city, ten samples were taken. Finally, the mean radon concentration value for each source was calculated. The mean (range) concentration of radon in the main sources were 6.9 (1.5-23.4) Becquerel/liter (Bq/L). Separately, springs and wells' means were 4.6 Bq/L and 9.5 Bq/L; respectively. For the residential tap water in the 7 regions, the results of the mean (range) concentration values were found to be 1.0 (0.9-1.3) Bq/L. For the old city, the mean (range) concentration values were 2.3 (0.9-3.9) Bq/L. Except for Al-Badan well, radon concentrations in the wells and springs were below the United State Environmental Protection Agency maximum contaminated level (U.S EPA MCL). The level was much lower for tap water. Although the concentration of radon in the tap water of old city were below the MCL, it was higher than other regions in the city. Preventive measures and population awareness on radon's exposure are recommended.

The utility of blood glucose meters in biotechnological applications.

PubMed

FitzGerald, Jennifer; Vermerris, Wilfred

2005-06-01

Most methods used to measure glucose concentrations in biotechnological settings are labour-intensive and/or expensive. With this in mind we have investigated the possibility of employing blood glucose meters, the use of which has the benefit of being fast, convenient and inexpensive, for this purpose. Accu-Chek Advantage (Roche Diagnostics, Indianapolis, IN, U.S.A.) and Precision QID (Medisense, Abbott Laboratories, Indianapolis, IN, U.S.A.) meters were tested using glucose samples of known concentration, at pH 7.5 and 4.8. The Accu-Chek Advantage meter uses strips containing the enzyme glucose dehydrogenase. This meter showed a linear response for glucose concentrations between 0.50 and 6.0 g/litre, and the effect of pH was small. The Precision QID meter uses strips containing the enzyme glucose oxidase and is more sensitive to pH. The displayed glucose concentrations at low pH values were consistently lower than at higher pH values. At both pH values the response curve reached a plateau, which limited the effective range of this meter to a range of 0.30-2.5 g/litre. Unlike the Precision QID meter, the Accu-Chek Advantage meter also responded to xylose and arabinose. A synergistic effect of combining sugars was observed when a mixture of sugars consisting of glucose and arabinose, or glucose and xylose, was applied: the displayed concentrations were consistently higher than was expected on the basis of the individual calibration curves. The use of glucose meters is a fast and convenient alternative to existing methods and may be of particular use for screening purposes where a high degree of accuracy is not crucial. The choice of meter should depend on the application, and in this respect the pH, expected concentration range and the presence of other sugars are among the factors that should be considered.

Occurrence, sources, and potential human health risks of polycyclic aromatic hydrocarbons in agricultural soils of the coal production area surrounding Xinzhou, China.

PubMed

Zhao, Long; Hou, Hong; Shangguan, Yuxian; Cheng, Bin; Xu, Yafei; Zhao, Ruifen; Zhang, Yigong; Hua, Xiaozan; Huo, Xiaolan; Zhao, Xiufeng

2014-10-01

A comprehensive investigation of the levels, distribution patterns, and sources of polycyclic aromatic hydrocarbons (PAHs) in agricultural soils of the coal production area surrounding Xinzhou, China, was conducted, and the potential human health risks associated with the levels observed were addressed. A total of 247 samples collected from agricultural soils from the area were analyzed for sixteen PAHs, including highly carcinogenic isomers. The PAH concentrations had a range of n.d. to 782ngg(-1), with a mean value of 202ngg(-1). The two-three ring PAHs were the dominant species, making up 60 percent of total PAHs. Compared with the pollution levels and carcinogenic potential risks reported in other studies, the soil PAH concentrations in the study area were in the low to intermediate range. A positive matrix factorization model indicates that coal/biomass combustion, coal and oil combustion, and coke ovens are the primary PAH sources, accounting for 33 percent, 26 percent, and 24 percent of total PAHs, respectively. The benzo[a]pyrene equivalent (BaPeq) concentrations had a range of n.d. to 476ngg(-1) for PAH7c, with a mean value of 34ngg(-1). The BaPeq concentrations of PAH7c accounted for more than 99 percent of the ∑PAH16, which suggests that seven PAHs were major carcinogenic contributors of ∑PAH16. According to the Canadian Soil Quality Guidelines, only six of the soil samples had concentrations above the safe BaPeq value of 600ngg(-1); the elevated concentrations observed at these sites can be attributed to coal combustion and industrial activities. Exposure to these soils through direct contact probably poses a significant risk to human health as a result of the carcinogenic effects of PAHs. Copyright © 2014 Elsevier Inc. All rights reserved.

Variability in δ13C values between individual Daphnia ephippia: Implications for palaeo-studies

NASA Astrophysics Data System (ADS)

Schilder, Jos; van Roij, Linda; Reichart, Gert-Jan; Sluijs, Appy; Heiri, Oliver

2018-06-01

The stable carbon isotope ratio (δ13C value) of Daphnia spp. resting egg shells (ephippia) provides information on past changes in Daphnia diet. Measurements are typically performed on samples of ≥20 ephippia, which obscures the range of values associated with individual ephippia. Using a recently developed laser ablation-based technique, we perform multiple δ13C analyses on individual ephippia, which show a high degree of reproducibility (standard deviations 0.1-0.5‰). We further measured δ13C values of 13 ephippia from surface sediments of three Swiss lakes. In the well-oxygenated lake with low methane concentrations, δ13C values are close to values typical for algae (-31.4‰) and the range in values is relatively small (5.8‰). This variability is likely driven by seasonal (or inter-annual) variability in algae δ13C values. In two seasonally anoxic lakes with higher methane concentrations, average values were lower (-41.4 and -43.9‰, respectively) and the ranges much larger (10.7 and 20.0‰). We attribute this variability to seasonal variation in incorporation of methane-derived carbon. In one lake we identify two statistically distinct isotopic populations, which may reflect separate production peaks. The potentially large within-sample variability should be considered when interpreting small-amplitude, short-lived isotope excursions based on samples consisting of few ephippia. We show that measurements on single ephippia can be performed using laser ablation, which allows for refined assessments of past Daphnia diet and carbon cycling in lake food webs. Furthermore, our study provides a basis for similar measurements on other chitinous remains (e.g. from chironomids, bryozoans).

Influence of pH and europium concentration on the luminescent and morphological properties of Y2O3 powders

NASA Astrophysics Data System (ADS)

Esquivel-Castro, Tzipatly; Carrillo-Romo, Felipe de J.; Oliva-Uc, Jorge; García-Murillo, Antonieta; Hirata-Flores, Gustavo A.; Cayetano-Castro, Nicolás; De la Rosa, Elder; Morales-Ramírez, Angel de J.

2015-10-01

This work reports on the synthesis and characterization of Y2O3:Eu3+ powders obtained by the hydrothermal method. We studied the influence of different pH values (7-12) and Eu3+ concentrations (2.5-25 mol%) on the structural, morphological and luminescent characteristics of Y2O3:Eu3+ powders. The hydrothermal synthesis was performed at 200 °C for 12 h by employing Y2O3, HNO3, H2O and Eu (NO3)3 as precursors, in order to obtain two sets of samples. The first set of powders was obtained with different pH values and named Eu5PHx (x = 7, 8, 9, 10, 11, and 12), and the second set was obtained by using a constant pH = 7 with different Eu concentrations, named EuxPH7 (x = 2.5, 5, 8, 15, 20 and 25). The XRD spectra showed that the Y2O3:Eu3+ powders exhibited a cubic phase, regardless of the pH values and Eu3+ concentrations. The SEM observations indicated that pH influenced the morphology and size of phosphors; for instance, for pH = 7, hexagonal microplatelets were obtained, and microrods at pH values from 8 to 12. Doping Y2O3 with various Eu3+ concentrations (in mol%) also produced changes in morphology, in these cases, hexagonal microplatelets were obtained in the range of 2.5-5 mol%, and non uniform plates were observed at higher doping concentrations ranging from 8 to 25 mol%. According to our results, the microplatelets synthesized with a pH of 7 and an 8 mol% Eu3+ concentration presented the highest luminescence under excitation at 254 nm. All of these results indicate that our phosphors could be useful for applications of controlled drug delivery, photocatalysis and biolabeling.

Comparison of the Force-, Velocity- and Power-Time Curves Between the Concentric-Only and Eccentric-Concentric Bench Press Exercises.

PubMed

Pérez-Castilla, Alejandro; Comfort, Paul; McMahon, John J; Pestaña-Melero, Francisco Luis; García-Ramos, Amador

2018-01-17

The aim of this study was to compare the temporal and mechanical variables between the concentric-only and eccentric-concentric bench press (BP) variants. Twenty-one men (age: 22.0±4.2 years, body mass: 73.4±7.7 kg, height: 177.2±8.0 cm; one-repetition maximum [1RM]: 1.12±0.12 kg⋅kg) were evaluated during the concentric-only and eccentric-concentric BP variants using 80% 1RM. Temporal (concentric phase duration, propulsive phase duration, and time to reach the maximum values of force, velocity, and power) and mechanical variables (force, velocity, and power), determined using a linear velocity transducer, were compared between both BP variants. All temporal variables were significantly lower during the eccentric-concentric BP compared to the concentric-only BP (P < 0.05; effect size [ES] range: 0.80-2.52). Maximum force as well as the mean values of velocity and power were significantly higher for the eccentric-concentric BP compared to the concentric-only BP (all P < 0.001; ES range: 2.87-3.58). However, trivial to small differences between both BP variants were observed for mean force (ES: 0.00-0.36) as well as for maximum velocity (ES: 0.40) and power (ES: 0.41). The stretch-shortening cycle (i.e., eccentric-concentric BP) mainly enhanced force production at the early portion of the concentric phase, but this potentiation effect gradually reduced over the latter part of the movement. Finally, force was higher for the concentric-only BP during 49% of the concentric phase duration. These results suggest that both BP variants should be included during resistance training programs in order to optimize force output at different points of the concentric phase.

Quantifying phosphoric acid in high-temperature polymer electrolyte fuel cell components by X-ray tomographic microscopy.

PubMed

Eberhardt, S H; Marone, F; Stampanoni, M; Büchi, F N; Schmidt, T J

2014-11-01

Synchrotron-based X-ray tomographic microscopy is investigated for imaging the local distribution and concentration of phosphoric acid in high-temperature polymer electrolyte fuel cells. Phosphoric acid fills the pores of the macro- and microporous fuel cell components. Its concentration in the fuel cell varies over a wide range (40-100 wt% H3PO4). This renders the quantification and concentration determination challenging. The problem is solved by using propagation-based phase contrast imaging and a referencing method. Fuel cell components with known acid concentrations were used to correlate greyscale values and acid concentrations. Thus calibration curves were established for the gas diffusion layer, catalyst layer and membrane in a non-operating fuel cell. The non-destructive imaging methodology was verified by comparing image-based values for acid content and concentration in the gas diffusion layer with those from chemical analysis.

Diel cycles in dissolved metal concentrations in streams: Occurrence and possible causes

USGS Publications Warehouse

Nimick, David A.; Gammons, Christopher H.; Cleasby, Thomas E.; Madison, James P.; Skaar, Don; Brick, Christine M.

2003-01-01

Substantial diel (24‐hour) cycles in dissolved (0.1‐μm filtration) metal concentrations were observed during low flow for 18 sampling episodes at 14 sites on 12 neutral and alkaline streams draining historical mining areas in Montana and Idaho. At some sites, concentrations of Cd, Mn, Ni, and Zn increased as much as 119, 306, 167, and 500%, respectively, from afternoon minimum values to maximum values shortly after sunrise. Arsenic concentrations exhibited the inverse temporal pattern with increases of up to 54%. Variations in Cu concentrations were small and inconsistent. Diel metal cycles are widespread and persistent, occur over a wide range of metal concentrations, and likely are caused primarily by instream geochemical processes. Adsorption is the only process that can explain the inverse temporal patterns of As and the divalent metals. Diel metal cycles have important implications for many types of water‐quality studies and for understanding trace‐metal mobility.

Use of real-time monitoring to predict concentrations of select constituents in the Menomonee River drainage basin, Southeast Wisconsin, 2008-9

USGS Publications Warehouse

Baldwin, Austin K.; Graczyk, David J.; Robertson, Dale M.; Saad, David A.; Magruder, Christopher

2012-01-01

The models to estimate chloride concentrations all used specific conductance as the explanatory variable, except for the model for the Little Menomonee River near Freistadt, which used both specific conductance and turbidity as explanatory variables. Adjusted R2 values for the chloride models ranged from 0.74 to 0.97. Models to estimate total suspended solids and total phosphorus used turbidity as the only explanatory variable. Adjusted R2 values ranged from 0.77 to 0.94 for the total suspended solids models and from 0.55 to 0.75 for the total phosphorus models. Models to estimate indicator bacteria used water temperature and turbidity as the explanatory variables, with adjusted R2 values from 0.54 to 0.69 for Escherichia coli bacteria models and from 0.54 to 0.74 for fecal coliform bacteria models. Dissolved oxygen was not used in any of the final models. These models may help managers measure the effects of land-use changes and improvement projects, establish total maximum daily loads, estimate important water-quality indicators such as bacteria concentrations, and enable informed decision making in the future.

Exposure to airborne culturable microorganisms and endotoxin in two Italian poultry slaughterhouses.

PubMed

Paba, Emilia; Chiominto, Alessandra; Marcelloni, Anna Maria; Proietto, Anna Rita; Sisto, Renata

2014-01-01

Even if slaughterhouses' workers handle large amounts of organic material and are potentially exposed to a wide range of biological agents, relatively little and not recent data are available. The main objective of this study was to characterize indoor concentrations of airborne bacteria, fungi, and endotoxin mod = Im (endotoxin∼Gram-negative*plant*filter) in two Italian poultry slaughterhouses. Air samples near air handling units inlets were also collected. Since there are not standardized protocols for endotoxin sampling and extraction procedures, an additional aim of the study was to compare the extraction efficiency of three different filter.. The study was also aimed at determining the correlation between concentrations of Gram-negative bacteria and endotoxin. In Plant A bacterial levels ranged from 17.5 to 2.6×10(3) CFU/m3. The highest concentrations were observed in evisceration area of chickens, between the automatic detachment of the neck and washing offal, and near birds coupling before hair-chilling. The highest mean value of Gram-negative (266.5 CFU/m3) was found near the washing offal of turkeys. In Plant B bacterial concentration ranged from 35 to 8×10(3) CFU/m3. The highest concentration. with the highest value of Gram-negative (248 CFU/m3), was found after defeathering. Fungal concentrations were overall lower than those found for bacteria (range: 0-205 CFU/m3 in Plant A and 0-146.2 CFU/m3 in Plant B). The microbial flora was dominated by Gram-negative and coagulase-negative staphylococci for bacteria and by species belonging to Cladosporium, Penicillium and Aspergillus genera for molds. The highest endotoxin concentrations were measured in washing offal for Plant A (range: 122.7-165.9 EU/m3) and after defeathering for Plant B (range: 0.83-38.85 EU/m3). In this study airborne microorganisms concentrations were lower than those found in similar occupational settings and below the occupational limits proposed by some authors. However, these microorganisms may exert adverse effects on exposed workers, in particular for those engaged in the early slaughtering stages, as evidenced by the presence of pathogenic species. The detection of pathogenic bacteria near AHU inlet may constitute a risk to public health and environmental pollution.

High feather mercury concentrations in the wandering albatross are related to sex, breeding status and trophic ecology with no demographic consequences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bustamante, Paco, E-mail: pbustama@univ-lr.fr; Carravieri, Alice; Centre d’Etudes Biologiques de Chizé

Hg can affect physiology of seabirds and ultimately their demography, particularly if they are top consumers. In the present study, body feathers of >200 wandering albatrosses from Possession Island in the Crozet archipelago were used to explore the potential demographic effects of the long-term exposure to Hg on an apex predator. Variations of Hg with sex, age class, foraging habitat (inferred from δ{sup 13}C values), and feeding habits (inferred from δ{sup 15}N values) were examined as well as the influence of Hg on current breeding output, long-term fecundity and survival. Wandering albatrosses displayed among the highest Hg feather concentrations reportedmore » for seabirds, ranging from 5.9 to 95 µg g{sup −1}, as a consequence of their high trophic position (δ{sup 15}N values). These concentrations fall within the same range of those of other wandering albatross populations from subantarctic sites, suggesting that this species has similar exposure to Hg all around the Southern Ocean. In both immature and adult albatrosses, females had higher Hg concentrations than males (28 vs. 20 µg g{sup −1} dw on average, respectively), probably as a consequence of females foraging at lower latitudes than males (δ{sup 13}C values). Hg concentrations were higher in immature than in adult birds, and they remained fairly constant across a wide range of ages in adults. Such high levels in immature individuals question (i) the frequency of moult in young birds, (ii) the efficiency of Hg detoxification processes in immatures compared to adults, and (iii) importantly the potential detrimental effects of Hg in early life. Despite very high Hg concentrations in their feathers, neither effects on adults' breeding probability, hatching failure and fledgling failure, nor on adults' survival rate were detected, suggesting that long-term bioaccumulated Hg was not under a chemical form leading to deleterious effects on reproductive parameters in adult individuals. - Highlights: • Immature albatrosses had higher feather Hg concentrations than adults. • Foraging habitat influenced Hg bioaccumulation as a result of male and female segregation. • No carry-over effects were detected on reproductive parameters.« less

Enlightenment about the new Architect-i2000 estradiol (Abbott Laboratories) immunoassay during in vitro fertilization.

PubMed

Taieb, Joëlle; Mendez Lozano, Daniel H; Benattar, Clarisse; Messaoudi, Chérif; Poüs, Christian

2007-12-01

We assessed a new estradiol (E2) immunoassay on the Architect-i2000 (Abbott Laboratories) for monitoring ovulation stimulation for IVF-ET and re-establishing clinical cut-off points. The method has been modified to improve E2 measurements especially at normal and low concentrations. E2 was determined for 552 samples, from 83 women, presenting normal follicular status and undergoing 100 cycles of IVF treatment. We assessed the value of this assay for down-regulation of E2 concentration limit using gonadoliberin-releasing hormone agonist (GnRHa), and monitoring of the ovarian hyperstimulation, expected range of E2 per mature follicle prior to the administration of exogenous hCG and day 3 concentration limit. We compared results with our routine method (E2-6II Advia-Centaur; Siemens-Diagnostics) for which decision-making values were known. Considering E2 concentrations obtained with the new Architect-i2000 assay for patients treated with GnRHa for 2 weeks, the cutoff-point for ovarian down-regulation should be set down at 110 pmol/L to maintain 100% of sensitivity. Considering day 3 concentration limit determination, results were not significantly different from those obtained with our routine method. The mean E2 values per mature follicle fell into the range generally expected. E2 determination with the new E2 Architect-i2000 assay could be used to monitor ovulation, in patients undergoing IVF-ET, in combination with transvaginal ultrasound.

Evaluation of metal concentration and antioxidant, antimicrobial, and anticancer potentials of two edible mushrooms Lactarius deliciosus and Macrolepiota procera.

PubMed

Kosanić, Marijana; Ranković, Branislav; Rančić, Aleksandar; Stanojković, Tatjana

2016-07-01

This study is designed for the determination of metal concentrations, antioxidant, antimicrobial, and anticancer potential of two edible mushrooms Lactarius deliciosus and Macrolepiota procera. Concentrations of nine metals are determined and all metals are present in the allowable concentrations in the tested mushrooms except Cd in M. procera. Antioxidant activity was evaluated by free radical scavenging and reducing power. M. procera extract had more potent free radical scavenging activity (IC 50 =311.40 μg/mL) than L. deliciosus extract. Moreover, the tested extracts had effective reducing power. The total content of phenol in the extracts was examined using Folin-Ciocalteu reagent and obtained values expressed as pyrocatechol equivalents. Further, the antimicrobial potential was determined with a microdilution method on 15 microorganisms. Among the tested species, extract of L. deliciosus showed a better antimicrobial activity with minimum inhibitory concentration values ranging from 2.5 mg/mL to 20 mg/mL. Finally, the cytotoxic activity was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method on human epithelial carcinoma HeLa cells, human lung carcinoma A549 cells, and human colon carcinoma LS174 cells. Extract of both mushrooms expressed similar cytotoxic activity with IC 50 values ranging from 19.01 μg/mL to 80.27 μg/mL. Copyright © 2016. Published by Elsevier B.V.

Evaluation of selected clinical and diagnostic parameters in girls with anorexia nervosa (I).

PubMed

Nogal, Paweł; Pniewska-Siark, Barbara; Lewiński, Andrzej

2008-08-01

Body weight loss in patients with anorexia nervosa (AN) is accompanied by a number of hormonal and metabolic disorders. The scope and intensity of these disorders may have a considerable influence on the prognosis in this disease. The goal of the study was an evaluation of selected diagnostic examinations in comparison with clinical data of female patients with AN. Retrospective studies involved eighty-seven (87) patients with AN. On therapy commencement, routine laboratory tests (full blood cell count, serum concentrations of sodium, potassium, glucose, cholesterol, triglycerides, total calcium, phosphates, total protein and the urea) and hormonal tests (TSH, TSH, FT4, FT3, E2, T, cortisol measured at 8(00), 17(00) and 24(00), LH and FSH in stimulation test with GnRH) were performed in each patient. Correlations were determined between clinical data and the measured hormone concentrations. In the studied girls, the mean values of routine laboratory tests, performed at the beginning of the therapy, were within the normal ranges (except hypernatremia). The mean concentrations of LH, FSH and FT4 were below reference values; the mean concentration of cortisol considerably exceeded the standard range. Statistically significant relations were demonstrated between BMI values and the concentrations of LH, E2 and cortisol. Body weigh loss is not significantly reflected by abnormal results of routinely performed laboratory tests. Hypogonadotropic hypogonadism and hypercortisolemia are the most characteristic hormonal symptoms in girls with AN.

Biodesulfurization of vanadium-bearing titanomagnetite concentrates and pH control of bioleaching solution

NASA Astrophysics Data System (ADS)

Liu, Xiao-rong; Jiang, Sheng-cai; Liu, Yan-jun; Li, Hui; Wang, Hua-jun

2013-10-01

Vanadium-bearing titanomagnetite concentrates were desulfurized with Acidithiobacillus ferrooxidans ( A. ferrooxidans). The sulfur content of the concentrates was reduced from 0.69wt% to 0.14wt% after bioleaching for 15 d with a 10% pulp density at 30°C. Maintaining a stable pH value during biodesulfurization was critical because of high acid consumption, resulting from a combination of nonoxidative and oxidative dissolution of pyrrhotite in acid solution. It is discovered that the citric acid-disodium hydrogen phosphate buffer of pH 2.0 can control the solution pH value smoothly in the optimal range of 2.0-3.0 for A. ferrooxidans growth. Using the buffer in the volume fraction range of 5.0%-15.0% stimulates A. ferrooxidans growth and improves the biodesulfurization efficiency. Compared with the buffer-free control case, the maximum increase of biodesulfurization rate is 29.7% using a 10.0vol% buffer. Bioleaching provides an alternative process for desulfurization of vanadium-bearing titanomagnetite ores.

Determination of the activity concentration levels of the artificial radionuclide137Cs in soil samples collected from Qatar using high-resolution gamma-ray spectrometry

NASA Astrophysics Data System (ADS)

Al-Sulaiti, Huda; Nasir, Tabassum; Al Mugren, K. S.; Alkhomashi, N.; Al-Dahan, N.; Al-Dosari, M.; Bradley, D. A.; Bukhari, S.; Regan, P. H.; Santawamaitre, T.; Malain, D.; Habib, A.; Al-Dosari, Hanan; Daar, Eman

2016-09-01

The goal of this study was to establish the first baseline measurements for radioactivity concentration of the artificial radionuclide 137Cs in soil samples collected from the Qatarian peninsula. The work focused on the determination of the activity concentrations levels of man-made radiation in 129 soil samples collected across the landscape of the State of Qatar. All the samples were collected before the most recent accident in Japan, “the 2011 Fukushima Dai-ichi nuclear power plant accident”. The activity concentrations have been measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector situated in a low-background environment with a copper inner-plated passive lead shield. A radiological map showing the activity concentrations of 137Cs is presented in this work. The concentration wasfound to range from 0.21 to 15.41 Bq/kg. The highest activity concentration of 137Cs was observed in sample no. 26 in North of Qatar. The mean value was found to be around 2.15 ± 0.27 Bq/kg. These values lie within the expected range relative to the countries in the region. It is expected that this contamination is mainly due to the Chernobyl accident on 26 April 1986, but this conclusion cannot be confirmed because of the lack of data before this accident.

Experimental characterization of Fresnel-Köhler concentrators

NASA Astrophysics Data System (ADS)

Zamora, Pablo; Benítez, Pablo; Mohedano, Rubén; Cvetković, Aleksandra; Vilaplana, Juan; Li, Yang; Hernández, Maikel; Chaves, Julio; Miñano, Juan C.

2012-01-01

Most cost-effective concentrated photovoltaics (CPV) systems are based on an optical train comprising two stages, the first being a Fresnel lens. Among them, the Fresnel-Köhler (FK) concentrator stands out owing to both performance and practical reasons. We describe the experimental measurements procedure for FK concentrator modules. This procedure includes three main types of measurements: electrical efficiency, acceptance angle, and irradiance uniformity at the solar cell plane. We have collected here the performance features of two different FK prototypes (ranging different f-numbers, concentration ratios, and cell sizes). The electrical efficiencies measured in both prototypes are high and fit well with the models, achieving values up to 32.7% (temperature corrected, and with no antireflective coating on SOE or POE surfaces) in the best case. The measured angular transmission curves show large acceptance angles, again perfectly matching the expected values [measured concentration acceptance product (CAP) values over 0.56]. The irradiance pattern on the cell (obtained with a digital camera) shows an almost perfectly uniform distribution, as predicted by raytrace simulations. All these excellent on-sun results confirm the FK concentrator as a potentially cost-effective solution for the CPV market.

40 CFR 1065.365 - Nonmethane cutter penetration fractions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... hydrocarbon standard or equal to the THC analyzer's span value. For CH4 analyzers with multiple ranges... single FID for THC and CH4 determination with an NMC that is calibrated with propane, C3H8, by bypassing... hydrocarbon standard and the C2H6 concentration typical of the peak total hydrocarbon (THC) concentration...

Variability of plasma homovanillic acid over 13 months in patients with schizophrenia; relationship with the clinical response and the Wisconsin card sort test.

PubMed

Zumárraga, Mercedes; González-Torres, Miguel A; Arrue, Aurora; Dávila, Ricardo; Dávila, Wendy; Inchausti, Lucía; Pérez-Cabeza, Lucía; Fernández-Rivas, Aránzazu; Bustamante, Sonia; Basterreche, Nieves; Guimón, José

2011-08-01

In the present study we have measured, on a monthly basis, the concentration of plasma homovanillic acid (pHVA) in schizophrenic patients during 13 months of their pharmacological treatment. The average pHVA values of each patient were within the range of 7.30-17.70 ng/ml and the coefficients of variation for each patient (CV %) were within the range of 13-33%. Half of the patients that showed higher pHVA CV% values also showed higher scores on the Brief Psychiatric Rating Scale at the beginning of the study, and improved more after 6 months, when compared to the remaining 50% with lower CV% values. There was no significant relationship between the scores of the Wisconsin Card Sort Test and the concentration or the CV% of the pHVA of each patient. A greater variability in the pHVA may be associated with a greater plasticity of the dopaminergic system and a better clinical response.

DDTs and other chlorinated organic pesticides and polychlorinated biphenyls pollution in the surface sediments of Keratsini harbour, Saronikos gulf, Greece.

PubMed

Galanopoulou, Stavroula; Vgenopoulos, Andreas; Conispoliatis, Nikolaos

2005-05-01

Sediment samples were collected from Keratsini harbour, Saronikos gulf, Greece and were analysed for chlorinated organic pesticides (DDTs, HCB, Lindane) and polychlorinated biphenyls (PCBs). High total DDTs values were detected in all the sediments samples ranging from 9.1 to 75.6 mug/g, dry weight. PCBs concentrations range from 47.8 to 351.8 ng/g. The results and especially the high concentrations of DDTs reflect the influence of the industrial and urban wastes in the pollution for the Keratsini harbour environment.

A chronicle of the changes undergone by a maritime territory, the Bay of Toulon (Var Coast, France), and their consequences on PCB contamination.

PubMed

Wafo, Emmanuel; Abou, Lydia; Nicolay, Alain; Boissery, Pierre; Perez, Thierry; Ngono Abondo, Rose; Garnier, Cédric; Chacha, Mama; Portugal, Henri

2016-01-01

This study evaluated the distribution of polychlorinated biphenyls (PCBs) in 39 surface sediment samples and four cores collected in Toulon Bay, a semiclosed area submitted to various anthropogenic inputs. The concentration of PCBs in the superficial sediment samples ranged from 1.7 to 2530 ng g(-1) dry weight. The spatial distribution of these compounds suggested that the high concentrations of these contaminants are located in the small bay and are related to human activities. In the larger bay, the concentrations were in the same order of magnitude than those reported in others locations around the world. Comparison of the levels with target values from the French legislation shows that, except for four polluted sites with critical values (N2: values ≥1 mg kg(-1) dry weight) in the smaller bay, PCBs levels throughout the larger and the smaller bay are lower than the accepted values (N1: values <0.5 mg kg(-1) dry weight). The PCBs in the sediment cores ranged from 0.8 to 739 ng g(-1) dry weight dependent core. Vertical profiles indicated earlier usage of PCBs which coincided with the history of the Toulon Bay. In this study, using alkane, we could follow the PCBs pollution history over about 80 years and estimate a sedimentation rate of about 0.32 cm year in the small Bay of Toulon.

An examination of the physical properties, fate, ecotoxicity and potential environmental risks for a series of propylene glycol ethers.

PubMed

Staples, Charles A; Davis, John W

2002-10-01

Propylene glycol ethers (PGEs) are comprised of mono-, di- and tri-PGEs and several of their acetate esters. The nature of the range of applications that use PGEs suggests that there is a potential for both intentional and unintentional entry of the materials into the environment. Selected physical/chemical properties, fate characteristics, aquatic toxicity data and calculated environmental concentrations were used to assess potential risks from the manufacture, handling, use, and disposal of PGEs. In general, the PGEs are low to moderately volatile, have high aqueous solubilities, low octanol-water partition coefficients (Kow), and bioconcentration factor values of <10, which indicate they are unlikely to accumulate in aquatic food chains. Both abiotic and biological degradation processes reduce environmental concentrations of PGEs. In air, vapor-phase PGEs react with photo-chemically produced hydroxyl radicals and have half-lives ranging from 5.5 to 34.4 h. A variety of ready and inherent biodegradation test methods, as well as tests that simulate biodegradation in wastewater treatment plants, surface water and soil have been conducted on PGEs. Significant aerobic biodegradation was generally observed, with a range of biodegradation half-lives on the order of 5-25 d. Acute aquatic toxicity studies with PGEs resulted in LC50 values ranging from approximately >100 to >20,000 mg/l for freshwater fish, the pelagic invertebrate Daphnia magna, green algae Selenastrum capricornutum (now called Pseudokirchneriella capricornutum) and bacteria. Level 3 multi-media modeling (EQC model of Mackay) was used to simulate regional-scale concentrations of PGEs in air, soil, water, and sediment. Toxicity thresholds were then compared with regional-scale water, soil and sediment concentrations to determine hazard quotients. Based upon this analysis, concentrations of PGEs are unlikely to pose adverse risks to the environment.

Spatial variability of soil 137Cs in the South Caspian region.

PubMed

Khoshbinfar, Soheil; Vahabi Moghaddam, Masoud

2012-05-01

In a comprehensive program of environmental radioactivity survey in South Caspian region, (137)Cs inventories in soil has been measured at more than 50 sites in the Iranian northern province of Guilan. This has been the first wide-range survey of soil radionuclide inventories in the narrow band sensitive ecosystem of south Caspian shore. Radioactivity measurements were carried out using HPGe gamma-spectrometry system. The activity concentration of (137)Cs in surface soil exhibits a mean value of 17.6 ± 9.4 Bq kg(-1), with a range of 2.3-41.7 Bq kg(-1). In many sites, split-level sampling method has been applied down to a depth of 20 cm. There were found generally two profiles. Most profiles exhibit a negative exponential distribution, while others revealed a clear subsurface peak in 5-10-cm layer. Cesium deposition in the study area has been estimated to be in the range of 0.38-2.9 kBq m(-2) with a mean value of 1.7 kBq m(-2). Distribution patterns of (137)Cs concentration levels and deposition values have been estimated using Kriging interpolation method. Observed hotspots in deposition pattern coincide with areas of higher precipitation.

Effect of γ-Al2O3/water nanofluid on the thermal performance of shell and coil heat exchanger with different coil torsions

NASA Astrophysics Data System (ADS)

Elshazly, K. M.; Sakr, R. Y.; Ali, R. K.; Salem, M. R.

2017-06-01

This work investigated experimentally the thermal performance of shell and coil heat exchanger with different coil torsions (λ) for γ-Al2O3/water nanofluid flow. Five helically coiled tube (HCT) with 0.0442 ≤ λ ≤ 0.1348 were tested within turbulent flow regime. The average size of γ-Al2O3 particles is 40 nm and volume concentration (φ) is varied from 0 to 2%. Results showed that reducing coil torsion enhances the heat transfer rate and increases HCT-friction factor (fc). Also, it is noticed that HCT average Nusselt number (Nut) and fc of nanofluids increase with increasing γ-Al2O3 volume concentration. The thermal performance index, TPI = (ht,nf/ht,bf)/(ΔPc,nf/ΔPc,bf). increases with increasing nanoparticles concentration, coil torsion, HCT-side inlet temperature and nanofluid flow rate. Over the studied range of HCT-Reynolds number, the average value of TPI is of 1.34 and 2.24 at φ = 0.5% and φ = 2%, respectively. The average value of TPI is of 1.64 at λ = 0.0442 while its average value at λ = 0.1348 is of 2.01. One of the main contributions is to provide heat equipments designers with Nut and fc correlations for practical configurations shell and coil heat exchangers with a wide range of nanofluid concentration.

Spatial variations in nitrogen dioxide concentrations in an urban area

NASA Astrophysics Data System (ADS)

Nicholas Hewitt, C.

Fortnightly average NO 2 concentrations have been measured at 49 sites in the small city of Lancaster, U.K., over a continuous 1-year period using passive diffusion tubes. At sampling sites on a congested main road in the city centre considerable spatial and temporal variability in concentrations was found. An annual mean concentration of 63 μgm -3 was found witha range of 12-222 μgm -3. The mean concentration in an adjacent main road was 58 μgm -3 with a range of 5-107 μgm -3. Rather less variability was seen in a suburban main road and in a suburban residential street, which had annual mean concentrations of 38 and 30 μm -3, respectively. Concentrations in a city centre pedestrian precinct decreased with distance from the main road, having an annual mean value of 30μm -3. The data suggest that the precise location of a sampling device may be crucial in determining whether or not a given NO 2, concentration or standard is exceeded.

Radioactivity measurement of nuts and seeds available in Erbil city markets

NASA Astrophysics Data System (ADS)

Ezzulddin, Saman Khabbat; Ahmed, Ali Hassan; Samad, Ahmed Ismael; Othman, Sardar Qader

2017-09-01

A study of natural and artificial radionuclides in nut and seed samples consumed in Erbil city has been performed. The NaI(TI) scintillation detector and nuclear track detector were used to measure the activity concentration of 40K, 232Th, 226Ra, 137Cs and 222Rn; respectively. The measured activity in samples ranges from (207.63 to 533.88) Bq.kg-1 with the mean value of 290.6 Bq.kg-1 for 40K, (0.031 to 0.52) Bq.kg-1 with a mean value of (0.149) Bq.kg-1for 226Ra (0.101 to 0.554) Bq.kg-1 with the mean value of (0.218) Bq.kg-1 for 232Th, 0.033 to 0.0.266 Bq.kg-1 with the mean value of (0.111) Bq.kg-1 for 137Cs and radon concentration ranged from 128.77to 298.1 Bq.m-3 with an average value of 202.7 Bq.m-3. To assess the radiological hazard due to natural radioactivity, the average values of the radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin) and Gamma index (Iγ) have been calculated to be (22.67) Bq/kg, (0.061), (1.12) and (0.195) respectively.

Natural radioactivity levels in granitic plutons and groundwaters in Southeast part of Eskisehir, Turkey.

PubMed

Orgün, Y; Altinsoy, N; Gültekin, A H; Karahan, G; Celebi, N

2005-08-01

The present work investigated the radioactivity level of the granitoid plutons and its effect on the groundwaters in the southeast part of Eskisehir. Fourteen granitic samples from the Kaymaz and Sivrihisar plutons and 11 groundwater samples from the near vicinity of the pluton were analyzed. The activity concentrations measured for (238)U and (232)Th ranged from 43.59+/-2 to 651.80+/-24 Bq/kg, and 51.16+/-3 to 351.94+/-13 Bq/kg, respectively. The activity concentrations obtained for (40)K varied from 418.50+/-17 to 1618.03+/-66 Bq/kg. The absorbed dose rates in air outdoors ranged from 87.14 to 531.81 nGy/h. All the results obtained from the Kaymaz pluton are higher than those from the Sivrihisar. The U (ave. 16.6 ppm) and Th (ave. 49.9 ppm) values of the Kaymaz pluton are higher than the average concentrations of the magmatic rocks of granitic composition. These results are consistent with high dose rates of the pluton. The gross-alpha activities in the groundwater samples ranged from 0.009 to 1.64 Bq/l and the gross-beta activities from 0.006 to 0.89 Bq/l. The highest gross-alpha value was found in the sample taken from near the Kaymaz pluton. The concentrations of (222)Rn varied from 0.060 to 0.557 Bq/l.

Ozone formation in pulsed SDBD in a wide pressure range

NASA Astrophysics Data System (ADS)

Starikovskiy, Andrey; Nudnova, Maryia; mipt Team

2011-10-01

Ozone concentration in surface anode-directed DBD for wide pressure range (150 - 1300 torr) was experimentally measured. Voltage and pressure effect were investigated. Reduced electric field was measured for anode-directed and cathode-directed SDBD. E/n values in cathode-directed SDBD is higher than in cathode-directed on 50 percent at atmospheric pressure. E/n value increase leads to decrease the rate of oxygen dissociation and Ozone formation at lower pressures. Radiating region thickness of sliding discharge was measured. Typical thickness of radiating zone is 0.4-1.0 mm within pressure range 220-740 torr. It was shown that high-voltage pulsed nanosecond discharge due to high E/n value produces less Ozone with compare to other discharges. Kinetic model was proposed to describe Ozone formation in the pulsed nanosecond SDBD.

Oral Supplementation with Bovine Colostrum Decreases Intestinal Permeability and Stool Concentrations of Zonulin in Athletes.

PubMed

Hałasa, Maciej; Maciejewska, Dominika; Baśkiewicz-Hałasa, Magdalena; Machaliński, Bogusław; Safranow, Krzysztof; Stachowska, Ewa

2017-04-08

Increased intestinal permeability has been implicated in various pathologies, has various causes, and can develop during vigorous athletic training. Colostrum bovinum is a natural supplement with a wide range of supposed positive health effects, including reduction of intestine permeability. We assessed influence of colostrum supplementation on intestinal permeability related parameters in a group of 16 athletes during peak training for competition. This double-blind placebo-controlled study compared supplementation for 20 days with 500 mg of colostrum bovinum or placebo (whey). Gut permeability status was assayed by differential absorption of lactulose and mannitol (L/M test) and stool zonulin concentration. Baseline L/M tests found that six of the participants (75%) in the colostrum group had increased intestinal permeability. After supplementation, the test values were within the normal range and were significantly lower than at baseline. The colostrum group Δ values produced by comparing the post-intervention and baseline results were also significantly lower than the placebo group Δ values. The differences in stool zonulin concentration were smaller than those in the L/M test, but were significant when the Δ values due to intervention were compared between the colostrum group and the placebo group. Colostrum bovinum supplementation was safe and effective in decreasing of intestinal permeability in this series of athletes at increased risk of its elevation.

Properties of colour reference solutions of the European Pharmacopoea in CIE L*a*b* colour space.

PubMed

Subert, J; Farsa, O; Gajdosová, Z

2006-12-01

The coordinates of CIE L*a*b* uniform colour space have been acquired from the transmitance spectra of colour reference solutions of European Pharmacopoeia (Ph.Eur.). Calculation of colour differences of these solutions from purified water deltaE* gave their values in the range between 0.7 (B9 solution) to 36 (Y1 solution) CIE units. Excluding red colour reference soulutions, deltaE* values did not depend on concentrations of colour compounds linearly. Small deltaE* values founded by the brown and brownish-yellow colour reference solutions of the lowest concentrations can possibly cause some problems of visual examination of the degree of coloration of liquids according to Ph.Eur.

Evaluation of a point-of-care glucose and β-hydroxybutyrate meter operated in various environmental conditions in prepartum and postpartum sheep.

PubMed

Hornig, Katlin J; Byers, Stacey R; Callan, Robert J; Holt, Timothy; Field, Megan; Han, Hyungchul

2013-08-01

To compare β-hydroxybutyrate (BHB) and glucose concentrations measured with a dual-purpose point-of-care (POC) meter designed for use in humans and a laboratory biochemical analyzer (LBA) to determine whether the POC meter would be reliable for on-farm measurement of blood glucose and BHB concentrations in sheep in various environmental conditions and nutritional states. 36 pregnant mixed-breed ewes involved in a maternal feed restriction study. Blood samples were collected from each sheep at multiple points throughout gestation and lactation to allow for tracking of gradually increasing metabolic hardship. Whole blood glucose and BHB concentrations were measured with the POC meter and compared with serum results obtained with an LBA. 464 samples were collected. Whole blood BHB concentrations measured with the POC meter compared well with LBA results, and error grid analysis showed the POC values were acceptable. Whole blood glucose concentrations measured with the POC meter had more variation, compared with LBA values, over the glucose ranges evaluated. Results of error grid analysis of POC-measured glucose concentrations were not acceptable, indicating errors likely to result in needless treatment with glucose or other supplemental energy sources in normoglycemic sheep. The POC meter was user-friendly and performed well across a wide range of conditions. The meter was adequate for detection of pregnancy toxemia in sheep via whole blood BHB concentration. Results should be interpreted with caution when the POC meter is used to measure blood glucose concentrations.

Frequency Selection for Multi-frequency Acoustic Measurement of Suspended Sediment

NASA Astrophysics Data System (ADS)

Chen, X.; HO, H.; Fu, X.

2017-12-01

Multi-frequency acoustic measurement of suspended sediment has found successful applications in marine and fluvial environments. Difficult challenges remain in regard to improving its effectiveness and efficiency when applied to high concentrations and wide size distributions in rivers. We performed a multi-frequency acoustic scattering experiment in a cylindrical tank with a suspension of natural sands. The sands range from 50 to 600 μm in diameter with a lognormal size distribution. The bulk concentration of suspended sediment varied from 1.0 to 12.0 g/L. We found that the commonly used linear relationship between the intensity of acoustic backscatter and suspended sediment concentration holds only at sufficiently low concentrations, for instance below 3.0 g/L. It fails at a critical value of concentration that depends on measurement frequency and the distance between the transducer and the target point. Instead, an exponential relationship was found to work satisfactorily throughout the entire range of concentration. The coefficient and exponent of the exponential function changed, however, with the measuring frequency and distance. Considering the increased complexity of inverting the concentration values when an exponential relationship prevails, we further analyzed the relationship between measurement error and measuring frequency. It was also found that the inversion error may be effectively controlled within 5% if the frequency is properly set. Compared with concentration, grain size was found to heavily affect the selection of optimum frequency. A regression relationship for optimum frequency versus grain size was developed based on the experimental results.

Ground-water-quality assessment of the Central Oklahoma aquifer, Oklahoma; hydrologic, water-quality, and quality-assurance data 1987-90

USGS Publications Warehouse

Ferree, D.M.; Christenson, S.C.; Rea, A.H.; Mesander, B.A.

1992-01-01

This report presents data collected from 202 wells between June 1987 and September 1990 as part of the Central Oklahoma aquifer pilot study of the National Water-Quality Assessment Program. The report describes the sampling networks, the sampling procedures, and the results of the ground-water quality and quality-assurance sample analyses. The data tables consist of information about the wells sampled and the results of the chemical analyses of ground water and quality-assurance sampling. Chemical analyses of ground-water samples in four sampling networks are presented: A geochemical network, a low-density survey bedrock network, a low-density survey alluvium and terrace deposits network, and a targeted urban network. The analyses generally included physical properties, major ions, nutrients, trace substances, radionuclides, and organic constituents. The chemical analyses of the ground-water samples are presented in five tables: (1) Physical properties and concentrations of major ions, nutrients, and trace substances; (2) concentrations of radionuclides and radioactivities; (3) carbon isotope ratios and delta values (d-values) of selected isotopes; (4) concentrations of organic constituents; and (5) organic constituents not reported in ground-water samples. The quality of the ground water sampled varied substantially. The sum of constituents (dissolved solids) concentrations ranged from 71 to 5,610 milligrams per liter, with 38 percent of the wells sampled exceeding the Secondary Maximum Contaminant Level of 500 milligrams per liter established under the Safe Drinking Water Act. Values of pH ranged from 5.7 to 9.2 units with 20 percent of the wells outside the Secondary Maximum Contaminant Level of 6.5 to 8.5 units. Nitrite plus nitrate concentrations ranged from less than 0.1 to 85 milligrams per liter with 8 percent of the wells exceeding the proposed Maximum Contaminant Level of 10 milligrams per liter. Concentrations of trace substances were highly variable, ranging from below the reporting level to concentrations over the Maximum Contaminant Levels for several constituents (arsenic, barium, cadmium, chromium, lead, and selenium). Radionuclide activities also were highly variable. Gross alpha radioactivity ranged from 0.1 to 210 picocuries per liter as 230thorium. Of the wells sampled, 20 percent exceeded the proposed Maximum Contaminant Level of 15 picocuries per liter for gross alpha radioactivity. Organic constituents were detected in 39 percent of the 170 wells sampled for organic constituents; in most cases concentrations were at or near the laboratory minimum reporting levels. Ten of the wells sampled for organic constituents had one or more constituents (chlordane, dieldrin, heptachlor epoxide, trichloroethylene, 1,1-dichloroethylene, 1,1,1-trichloroethane) at concentrations equal to or greater than the Maximum Contaminant Level or acceptable concentrations as suggested in the Environmental Protection Agency's Health Advisory Summaries. Quality-assurance sampling included duplicate samples, repeated samples, blanks, spikes, and blind samples. These samples proved to be essential in evaluating the accuracy of the data, particularly in the case of volatile organic constituents.

Monitoring of thiopurine metabolites in patients with inflammatory bowel disease-what is actually measured?

PubMed

Vikingsson, Svante; Carlsson, Björn; Almer, Sven H C; Peterson, Curt

2009-06-01

Azathioprine and 6-mercaptopurine are often used in the treatment of patients with inflammatory bowel disease (IBD). They are prodrugs and undergo a complex metabolism to active and inactive metabolites. Thiopurine treatment is monitored in many laboratories by measuring metabolite concentrations in erythrocytes (red blood cells). The metabolites of interest are not measured directly but as hydrolysis products, which can be produced from several metabolites. The aim of this study was to examine which metabolites are actually measured during routine monitoring. Samples from 18 patients treated with a thiopurine were analyzed by a typical routine high-performance liquid chromatography method for therapeutic drug monitoring and by a newly developed specific method measuring thioguanosine monophosphate (TGMP), thioguanosine diphosphate (TGDP), and thioguanosine triphosphate (TGTP), as well as methylthioinosine monophosphate (meTIMP), and the results were compared. 6-Thioguanine nucleotide (TGN) values detected by the routine method were 69% (range 40%-90%) of the sum of TGMP, TGDP, and TGTP measured by the specific method. TGTP and TGDP contributed 85% (range 78%-90%) and 14% (range 10%-21%) of the TGN total, respectively. Thioguanosine was not found in any patient sample. The concentration of meTIMP obtained by the routine method was 548% of the value obtained by the specific method (range 340%-718%). The difference in TGN measurements between the routine and specific methods can be explained by low hydrolysis efficiency in the routine method, although the most likely explanation for the difference in meTIMP values is that not yet identified metabolites are codetermined in the routine high-performance liquid chromatography method. Concentrations reported as TGN during therapeutic drug monitoring of thiopurine metabolites consist of TGDP and TGTP with a minor contribution of the TGMP. Concentrations reported as meTIMP or methyl mercaptopurine consist in part of meTIMP, but other not yet identified metabolites are codetermined.

Baseline groundwater quality from 20 domestic wells in Sullivan County, Pennsylvania, 2012

USGS Publications Warehouse

Sloto, Ronald A.

2013-01-01

Concentrations of dissolved methane ranged from less than 0.001 to 51.1 mg/L. Methane was not detected in water samples from 13 wells, and the methane concentration was less than 0.07 mg/L in samples from five wells. The highest dissolved methane concentrations were 4.1 and 51.1 mg/L, and the pH of the water from both wells was greater than 8. Water samples from these wells were analyzed for isotopes of carbon and hydrogen in the methane. The isotopic ratio values fell in the range for a thermogenic (natural gas) source. The water samples from these two wells had the highest concentrations of arsenic, boron, bromide, chloride, fluoride, lithium, molybdenum, and sodium of the 20 wells sampled.

Ice-nucleating particle concentrations unaffected by urban air pollution in Beijing, China

NASA Astrophysics Data System (ADS)

Chen, Jie; Wu, Zhijun; Augustin-Bauditz, Stefanie; Grawe, Sarah; Hartmann, Markus; Pei, Xiangyu; Liu, Zirui; Ji, Dongsheng; Wex, Heike

2018-03-01

Exceedingly high levels of PM2.5 with complex chemical composition occur frequently in China. It has been speculated whether anthropogenic PM2.5 may significantly contribute to ice-nucleating particles (INP). However, few studies have focused on the ice-nucleating properties of urban particles. In this work, two ice-nucleating droplet arrays have been used to determine the atmospheric number concentration of INP (NINP) in the range from -6 to -25 °C in Beijing. No correlations between NINP and either PM2.5 or black carbon mass concentrations were found, although both varied by more than a factor of 30 during the sampling period. Similarly, there were no correlations between NINP and either total particle number concentration or number concentrations for particles with diameters > 500 nm. Furthermore, there was no clear difference between day and night samples. All these results indicate that Beijing air pollution did not increase or decrease INP concentrations in the examined temperature range above values observed in nonurban areas; hence, the background INP concentrations might not be anthropogenically influenced as far as urban air pollution is concerned, at least in the examined temperature range.

The influence of trehalose on hydrophobic interactions of small nonpolar solute: A molecular dynamics simulation study

NASA Astrophysics Data System (ADS)

Paul, Subrata; Paul, Sandip

2013-07-01

Molecular dynamics simulations were carried out to investigate the influences of aqueous trehalose solution on the hydrophobic interactions between neopentane molecules. In this study, we consider six different trehalose concentrations ranging from 0% to 56%. We observe that with increasing trehalose concentration the dispersion of solute neopentane takes place. The neopentane-neopentane association constant value decreases with addition of trehalose. Our preferential interaction calculations suggest that with increasing trehalose concentration neopentane interacts preferentially with water over trehalose. Site-site neopentane-trehalose rdfs indicate that trehalose molecules are expelled out from the neopentane surface. Also observed are (i) trehalose induced second shell collapse of water network (ii) decrease in average number of water-water and water-trehalose hydrogen bonds with increasing trehalose concentration. We also find that addition of trehalose decreases the translational motion of all the solution species. The decrease in diffusion coefficient value is more pronounced for trehalose. We, further, observe that the ratio of the diffusion coefficient values of water and trehalose increases with increasing trehalose concentration.

Partitioning in REE-saturating minerals - Theory, experiment, and modelling of whitlockite, apatite, and evolution of lunar residual magmas

NASA Technical Reports Server (NTRS)

Jolliff, Bradley L.; Haskin, Larry A.; Colson, Russell O.; Wadhwa, Meenakshi

1993-01-01

Compositions, including REEs determined by ion microprobe, of apatite and whitlockite in lunar rock assemblages rich in incompatible trace elements, are presented. Concentrations of REEs in lunar whitlockites are high, ranging from about 1.2 to 2.1 REEs (lanthanides + Y) per 56 oxygens. This slightly exceeds the level of two REE atoms per 56 oxygens at which the dominant substitution theoretically becomes saturated. This saturation effect leads to whitlockite REE(3+) D values at typical lunar whitlockite REE concentrations which are 30-40 percent lower than the D values at low concentrations. The halogen-to-phosphorous ratio in lunar melts is a key factor determining the REE distribution with crystalline assemblages. As long as P and REE concentrations of melts are in KREEP-like proportions, one or both of the phosphates will saturate in melts at similar REE concentrations.

Nitric oxide concentration near the mesopause as deduced from ionospheric absorption measurements

NASA Astrophysics Data System (ADS)

Lastovicka, J.

The upper-D-region NO concentration is calculated on the basis of published 2775-kHz-absorption, Lyman-alpha (OSO-5), and X-ray (Solrad-9) data obtained over Central Europe in June-August 1969, 1970, and 1972. Ionization-rate and radio-wave-absorption profiles for solar zenith angles of 60, 70 and 40 deg are computed, presented graphically, and compared with model calculations to derive the NO-concentration correction coefficients necessary to make the Lyman-alpha/X-ray flux ratios of the models of Meira (1971), Baker et al. (1977), Tohmatsu and Iwagami (1976), and Tisone (1973) agree with the observed ratios. Values of the corrected NO concentration include 6.5 and 8.5 x 10 to the 13th/cu m at 78 and 90 km, respectively. The values are shown to be higher than those of standard models but within the range of observed concentrations.

Effect of Temperature and Nutrient Manipulations on eelgrass ...

EPA Pesticide Factsheets

Global climate change will have a large impact on the three predominate drivers of estuarine seagrass productivity, temperature, light and nutrients. I experimentally evaluate the response of Pacific Northwest Z. marina to interactive effects of temperature and nutrient conditions. Experimental manipulations were conducted hydroponically in acrylic chambers and spanned a range of temperatures and nutrient concentrations. Preliminary single factor experiments were conducted to evaluate physiological tolerances to temperature and nitrogen concentrations. Eelgrass exhibited a linear increase in specific growth with increasing NH4 concentration (range from 10 to 1000 µM); in contrast, there was no significant relationship between specific growth rate and increasing NO3 concentration over the same concentration range. Leaf growth metrics all exhibited strong linear relationships with increasing water temperature (temperature range 4-25 ºC). In the factorial experiment, plants were exposed to 3 temperatures (10, 18 and 25 ºC) and 3 nitrate concentrations (10, 30 and 100 µM) with 3 replicate chambers per treatment combination. Most metrics (leaf elongation, growth, specific growth, wasting index) exhibited a significant temperature effect indicating the importance of temperature on metabolic rates. Tissue stable isotope ratios and C:N values exhibited a significant nutrient effect and in some cases a significant temperature effect. Whole plant non structur

Fragment Discovery for the Design of Nitrogen Heterocycles as Mycobacterium tuberculosis Dihydrofolate Reductase Inhibitors.

PubMed

Shelke, Rupesh U; Degani, Mariam S; Raju, Archana; Ray, Mukti Kanta; Rajan, Mysore G R

2016-08-01

Fragment-based drug design was used to identify Mycobacterium tuberculosis (Mtb) dihydrofolate reductase (DHFR) inhibitors. Screening of ligands against the Mtb DHFR enzyme resulted in the identification of multiple fragment hits with IC50 values in the range of 38-90 μM versus Mtb DHFR and minimum inhibitory concentration (MIC) values in the range of 31.5-125 μg/mL. These fragment scaffolds would be useful for anti-tubercular drug design. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Altered blood glucose concentration is associated with risk of death among patients with community-acquired Gram-negative rod bacteremia.

PubMed

Peralta, Galo; Sánchez, M Blanca; Garrido, J Carlos; Ceballos, Begoña; Mateos, Fátima; De Benito, Inés; Roiz, M Pía

2010-06-22

Altered blood glucose concentration is commonly observed in patients with sepsis, even among those without hypoglycemic treatments or history of diabetes mellitus. These alterations in blood glucose are potentially detrimental, although the precise relationship with outcome in patients with bacteremia has not been yet determined. A retrospective cohort study design for analyzing patients with Gram negative rod bacteremia was employed, with the main outcome measure being in-hospital mortality. Patients were stratified in quintiles accordingly deviation of the blood glucose concentration from a central value with lowest mortality. Cox proportional-hazards regression model was used for determining the relationship of same day of bacteremia blood glucose and death. Of 869 patients identified 63 (7.4%) died. Same day of bacteremia blood glucose concentration had a U-shaped relationship with in-hospital mortality. The lowest mortality (2%) was detected in the range of blood glucose concentration from 150 to 160 mg/dL. Greater deviation of blood glucose concentration from the central value of this range (155 mg/dL, reference value) was directly associated with higher risk of death (p = 0.002, chi for trend). The low-risk group (quintile 1) had a mortality of 3.3%, intermediate-risk group (quintiles 2, 3 and 4) a mortality of 7.1%, and the high-risk group (quintile 5) a mortality of 12.05%. In a multivariable Cox regression model, the hazard ratio for death among patients in the intermediate-risk group as compared with that in the low risk group was 2.88 (95% confidence interval, 1.01 to 8.18; P = 0.048), and for the high risk group it was 4.26 (95% confidence interval, 1.41 to 12.94; P = 0.01). Same day of bacteremia blood glucose concentration is related with outcome of patients with Gram-negative rod bacteremia. Lowest mortality is detected in patients with blood glucose concentration in an interval of 150-160 mg/dL. Deviations from these values are associated with an increased risk of death.

Altered blood glucose concentration is associated with risk of death among patients with community-acquired Gram-negative rod bacteremia

PubMed Central

2010-01-01

Background Altered blood glucose concentration is commonly observed in patients with sepsis, even among those without hypoglycemic treatments or history of diabetes mellitus. These alterations in blood glucose are potentially detrimental, although the precise relationship with outcome in patients with bacteremia has not been yet determined. Methods A retrospective cohort study design for analyzing patients with Gram negative rod bacteremia was employed, with the main outcome measure being in-hospital mortality. Patients were stratified in quintiles accordingly deviation of the blood glucose concentration from a central value with lowest mortality. Cox proportional-hazards regression model was used for determining the relationship of same day of bacteremia blood glucose and death. Results Of 869 patients identified 63 (7.4%) died. Same day of bacteremia blood glucose concentration had a U-shaped relationship with in-hospital mortality. The lowest mortality (2%) was detected in the range of blood glucose concentration from 150 to 160 mg/dL. Greater deviation of blood glucose concentration from the central value of this range (155 mg/dL, reference value) was directly associated with higher risk of death (p = 0.002, chi for trend). The low-risk group (quintile 1) had a mortality of 3.3%, intermediate-risk group (quintiles 2, 3 and 4) a mortality of 7.1%, and the high-risk group (quintile 5) a mortality of 12.05%. In a multivariable Cox regression model, the hazard ratio for death among patients in the intermediate-risk group as compared with that in the low risk group was 2.88 (95% confidence interval, 1.01 to 8.18; P = 0.048), and for the high risk group it was 4.26 (95% confidence interval, 1.41 to 12.94; P = 0.01). Conclusions Same day of bacteremia blood glucose concentration is related with outcome of patients with Gram-negative rod bacteremia. Lowest mortality is detected in patients with blood glucose concentration in an interval of 150-160 mg/dL. Deviations from these values are associated with an increased risk of death. PMID:20569435

Chlorine isotope geochemistry of Icelandic thermal fluids: Implications for geothermal system behavior at divergent plate boundaries

NASA Astrophysics Data System (ADS)

Stefánsson, Andri; Barnes, Jaime D.

2016-09-01

The chlorine isotope composition of thermal fluids from Iceland were measured in order to evaluate the source of chlorine and possible chlorine isotope fractionation in geothermal systems at divergent plate boundaries. The geothermal systems studied have a wide range of reservoir temperatures from 40 to 437 °C and in-situ pH of 6.15 to 7.15. Chlorine concentrations range from 5.2 to 171 ppm and δ37 Cl values are -0.3 to + 2.1 ‰ (n = 38). The δ37 Cl values of the thermal fluids are interpreted to reflect the source of the chlorine in the fluids. Geothermal processes such as secondary mineral formation, aqueous and vapor speciation and boiling were found to have minimal effects on the δ37 Cl values. However, further work is needed on incorporation of Cl into secondary minerals and its effect on Cl isotope fractionation. Results of isotope geochemical modeling demonstrate that the range of δ37 Cl values documented in the natural thermal fluids can be explained by leaching of the basaltic rocks by meteoric source water under geothermal conditions. Magmatic gas partitioning may also contribute to the source of Cl in some cases. The range of δ37 Cl values of the fluids result mainly from the large range of δ37 Cl values observed for Icelandic basalts, which range from -0.6 to + 1.2 ‰.

Technical note: False low turbidity readings from optical probes during high suspended-sediment concentrations

NASA Astrophysics Data System (ADS)

Voichick, Nicholas; Topping, David J.; Griffiths, Ronald E.

2018-03-01

Turbidity, a measure of water clarity, is monitored for a variety of purposes including (1) to help determine whether water is safe to drink, (2) to establish background conditions of lakes and rivers and detect pollution caused by construction projects and stormwater discharge, (3) to study sediment transport in rivers and erosion in catchments, (4) to manage siltation of water reservoirs, and (5) to establish connections with aquatic biological properties, such as primary production and predator-prey interactions. Turbidity is typically measured with an optical probe that detects light scattered from particles in the water. Probes have defined upper limits of the range of turbidity that they can measure. The general assumption is that when turbidity exceeds this upper limit, the values of turbidity will be constant, i.e., the probe is pegged; however, this assumption is not necessarily valid. In rivers with limited variation in the physical properties of the suspended sediment, at lower suspended-sediment concentrations, an increase in suspended-sediment concentration will cause a linear increase in turbidity. When the suspended-sediment concentration in these rivers is high, turbidity levels can exceed the upper measurement limit of an optical probe and record a constant pegged value. However, at extremely high suspended-sediment concentrations, optical turbidity probes do not necessarily stay pegged at a constant value. Data from the Colorado River in Grand Canyon, Arizona, USA, and a laboratory experiment both demonstrate that when turbidity exceeds instrument-pegged conditions, increasing suspended-sediment concentration (and thus increasing turbidity) may cause optical probes to record decreasing false turbidity values that appear to be within the valid measurement range of the probe. Therefore, under high-turbidity conditions, other surrogate measurements of turbidity (e.g., acoustic-attenuation measurements or suspended-sediment samples) are necessary to correct these low false turbidity measurements and accurately measure turbidity.

Temperature Coefficients of Electrical Conductivity and Conduction Mechanisms in Butyl Rubber-Carbon Black Composites

NASA Astrophysics Data System (ADS)

Alzamil, M. A.; Alfaramawi, K.; Abboudy, S.; Abulnasr, L.

2018-02-01

Electrical properties of butyl rubber filled with General Purpose Furnace (GPF) carbon black were studied. The carbon black concentration ( X) in the compound was X = 40, 60, 70, 80, and 100 parts by weight per hundred parts by weight of rubber (phr). The corresponding volume fractions of GPF carbon black were 0.447 ± 0.022, 0.548 ± 0.027, 0.586 ± 0.029, 0.618 ± 0.031 and 0.669 ± 0.034, respectively. The concentration dependence of conductivity ( σ ) at constant temperature showed that σ follows a percolation theory; σ ∝ ( {X - Xo } )^{γ } , where X o is the concentration at percolation threshold. The exponent γ was found as 6.6 (at room temperature 30°C). This value agrees with other experimental values obtained by many authors for different rubber-carbon black systems. Electron tunneling between the aggregates, which are dispersed in the insulator rubber, was mainly the conduction process proposed at constant temperature in the butyl-GPF carbon black composites. Temperature dependence of conductivity was investigated in the temperature range from 30°C up to 120°C. All samples exhibit negative temperature coefficients of conductivity (NTCC). The values obtained are - 0.130°C-1, - 0.019°C-1, - 0.0082°C-1, - 0.0094°C-1, and - 0.072°C-1 for carbon black concentrations of 40 phr, 60 phr, 70 phr, 80 phr, and 100 phr, respectively. The samples of concentrations 40 phr and 60 phr have also positive temperature coefficients of conductivity (PTCC) of values + 0.031 and + 0.013, respectively. Electrical conduction at different temperatures showed various mechanisms depending on the carbon black concentration and/or the interval of temperature. The hopping conduction mechanism was noticed at the lower temperature region while carrier thermal activation mechanisms were recorded at the higher temperature range.

Technical note: False low turbidity readings from optical probes during high suspended-sediment concentrations

USGS Publications Warehouse

Voichick, Nicholas; Topping, David; Griffiths, Ronald

2018-01-01

Turbidity, a measure of water clarity, is monitored for a variety of purposes including (1) to help determine whether water is safe to drink, (2) to establish background conditions of lakes and rivers and detect pollution caused by construction projects and stormwater discharge, (3) to study sediment transport in rivers and erosion in catchments, (4) to manage siltation of water reservoirs, and (5) to establish connections with aquatic biological properties, such as primary production and predator–prey interactions. Turbidity is typically measured with an optical probe that detects light scattered from particles in the water. Probes have defined upper limits of the range of turbidity that they can measure. The general assumption is that when turbidity exceeds this upper limit, the values of turbidity will be constant, i.e., the probe is pegged; however, this assumption is not necessarily valid. In rivers with limited variation in the physical properties of the suspended sediment, at lower suspended-sediment concentrations, an increase in suspended-sediment concentration will cause a linear increase in turbidity. When the suspended-sediment concentration in these rivers is high, turbidity levels can exceed the upper measurement limit of an optical probe and record a constant pegged value. However, at extremely high suspended-sediment concentrations, optical turbidity probes do not necessarily stay pegged at a constant value. Data from the Colorado River in Grand Canyon, Arizona, USA, and a laboratory experiment both demonstrate that when turbidity exceeds instrument-pegged conditions, increasing suspended-sediment concentration (and thus increasing turbidity) may cause optical probes to record decreasing false turbidity values that appear to be within the valid measurement range of the probe. Therefore, under high-turbidity conditions, other surrogate measurements of turbidity (e.g., acoustic-attenuation measurements or suspended-sediment samples) are necessary to correct these low false turbidity measurements and accurately measure turbidity.

Hematology and serum clinical chemistry reference intervals for free-ranging Scandinavian gray wolves (Canis lupus).

PubMed

Thoresen, Stein I; Arnemo, Jon M; Liberg, Olof

2009-06-01

Scandinavian free-ranging wolves (Canis lupus) are endangered, such that laboratory data to assess their health status is increasingly important. Although wolves have been studied for decades, most biological information comes from captive animals. The objective of the present study was to establish reference intervals for 30 clinical chemical and 8 hematologic analytes in Scandinavian free-ranging wolves. All wolves were tracked and chemically immobilized from a helicopter before examination and blood sampling in the winter of 7 consecutive years (1998-2004). Seventy-nine blood samples were collected from 57 gray wolves, including 24 juveniles (24 samples), 17 adult females (25 samples), and 16 adult males (30 samples). Whole blood and serum samples were stored at refrigeration temperature for 1-3 days before hematologic analyses and for 1-5 days before serum biochemical analyses. Reference intervals were calculated as 95% confidence intervals except for juveniles where the minimum and maximum values were used. Significant differences were observed between adult and juvenile wolves for RBC parameters, alkaline phosphatase and amylase activities, and total protein, albumin, gamma-globulins, cholesterol, creatinine, calcium, chloride, magnesium, phosphate, and sodium concentrations. Compared with published reference values for captive wolves, reference intervals for free-ranging wolves reflected exercise activity associated with capture (higher creatine kinase activity, higher glucose concentration), and differences in nutritional status (higher urea concentration).

Analysis of Tank 38H (HTF-38-16-26, 27) and Tank 43H (HTF-43-16-28, 29) Samples for Support of the Enrichment Control and Corrosion Control Programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hay, M. S.

Savannah River National Laboratory analyzed samples from Tank 38H and Tank 43H to support Enrichment Control Program and Corrosion Control Program. The total uranium in the Tank 38H samples ranged from 20.5 to 34.0 mg/L while the Tank 43H samples ranged from 47.6 to 50.6 mg/L. The U-235 percentage ranged from 0.62% to 0.64% over the four samples. The total uranium and percent U-235 results appear consistent with previous Tank 38H and Tank 43H uranium measurements. The Tank 38H plutonium results show a large difference between the surface and sub-surface sample concentrations and a somewhat higher concentration than previous sub-surfacemore » samples. The two Tank 43H samples show similar plutonium concentrations and are within the range of values measured on previous samples. The plutonium results may be biased high due to the presence of plutonium contamination in the blank samples from the cell sample preparations. The four samples analyzed show silicon concentrations ranging from 47.9 to 105 mg/L.« less

A novel way to monitor urine concentration: fluorescent concentration matrices.

PubMed

Dubayova, Katarina; Luckova, Iveta; Sabo, Jan; Karabinos, Anton

2015-01-01

The amount of water found in urine is important diagnostic information; nevertheless it is not yet directly determined. Indirectly, the water content in urine is expressed by its density (specific gravity). However, without the diuresis value it is not possible to determine whether the increase in density of urine is due to a decrease in water secretion or an increase in the concentration of secreted substances. This problem can be solved by the use of fluorescent concentration 3D-matrices which characterise urine concentration through the pφ (or -logφ) value of the first fluorescence centre. The urine fluorescent concentration 3D-matrix was created by the alignment of the synchronous spectra of the dilution series of urine starting from undiluted (pφ = 0) to 1000-fold diluted urine (pφ = 3). Using the fluorescence concentration 3D-matrix analysis of the urine samples from healthy individuals, a reference range was established for the value pφ, determining the normal, concentrated or diluted type of urine. The diagnostic potential of this approach was tested on urine samples from two patients with a chronic glomerulonephritis. The pφ value of the urine fluorescence concentration 3D-matrix analysis determines whether the urine sample falls within the normal, concentrated or diluted type of urine. This parameter can be directly utilised in sportsmen's hydration state monitoring, as well as in the diagnosis and treatment of serious diseases. An important advantage of this novel diagnostic approach is that a 12/24 h urine collection is not required, which predetermines it for use especially within paediatrics.

Toxicity reference values for chlorophacinone and their application for assessing anticoagulant rodenticide risk to raptors.

PubMed

Rattner, Barnett A; Horak, Katherine E; Lazarus, Rebecca S; Schultz, Sandra L; Knowles, Susan; Abbo, Benjamin G; Volker, Steven F

2015-05-01

Despite widespread use and benefit, there are growing concerns regarding hazards of second-generation anticoagulant rodenticides to non-target wildlife which may result in expanded use of first-generation compounds, including chlorophacinone (CPN). The toxicity of CPN over a 7-day exposure period was investigated in American kestrels (Falco sparverius) fed either rat tissue mechanically-amended with CPN, tissue from rats fed Rozol(®) bait (biologically-incorporated CPN), or control diets (tissue from untreated rats or commercial bird of prey diet) ad libitum. Nominal CPN concentrations in the formulated diets were 0.15, 0.75 and 1.5 µg/g food wet weight, and measured concentrations averaged 94 % of target values. Kestrel food consumption was similar among groups and body weight varied by less than 6 %. Overt signs of intoxication, liver CPN residues, and changes in prothrombin time (PT), Russell's viper venom time (RVVT) and hematocrit, were generally dose-dependent. Histological evidence of hemorrhage was present at all CPN dose levels, and most frequently observed in pectoral muscle and heart. There were no apparent differences in toxicity between mechanically-amended and biologically-incorporated CPN diet formulations. Dietary-based toxicity reference values at which clotting times were prolonged in 50 % of the kestrels were 79.2 µg CPN consumed/kg body weight-day for PT and 39.1 µg/kg body weight-day for RVVT. Based upon daily food consumption of kestrels and previously reported CPN concentrations found in small mammals following field baiting trials, these toxicity reference values might be exceeded by free-ranging raptors consuming such exposed prey. Tissue-based toxicity reference values for coagulopathy in 50 % of exposed birds were 0.107 µg CPN/g liver wet weight for PT and 0.076 µg/g liver for RVVT, and are below the range of residue levels reported in raptor mortality incidents attributed to CPN exposure. Sublethal responses associated with exposure to environmentally realistic concentrations of CPN could compromise survival of free-ranging raptors, and should be considered in weighing the costs and benefits of anticoagulant rodenticide use in pest control and eradication programs.

Effect of increasing Helicobacter pylori ammonia production by urea infusion on plasma gastrin concentrations.

PubMed Central

Chittajallu, R S; Neithercut, W D; Macdonald, A M; McColl, K E

1991-01-01

It has been proposed that the hypergastrinaemia in subjects with Helicobacter pylori infection is caused by the action of the ammonia produced by the organism's urease activity on the antral G cells. To investigate this hypothesis we examined the effect on plasma gastrin of increasing the bacterium's ammonia production by infusing urea intragastrically to eight H pylori positive duodenal ulcer patients. After a 60 minute control intragastric infusion of dextrose solution at 2 ml/minute, a similar infusion containing urea (50 mmol/l) was continued for four hours. During the urea infusion, the median gastric juice urea concentration rose from 1.1 mmol/l (range 0.3-1.6) to 15.5 mmol/l (range 7.9-21.3) and this resulted in an increase in the ammonium concentration from 2.3 mmol/l (range 1.3-5.9) to 6.1 mmol/l (range 4.2-11.9) (p less than 0.01). This appreciable rise in ammonia production did not result in any change in the plasma gastrin concentration. The experiment was repeated one month after eradication of H pylori, at which time the median basal gastrin was 20 ng/l (range 15-25), significantly less than the value before eradication (30 ng/l range 15-60) (p less than 0.05). On this occasion, the gastric juice ammonium concentration was considerably reduced at 0.4 mmol/l (range 0.1-0.9) and the urea infusion did not raise the ammonium concentration or change the plasma gastrin concentration. In conclusion, augmenting H pylori ammonia production does not cause any early change in plasma gastrin. PMID:1991633

Carbon Isotope Composition as an Indicator of DOC Sources to a Stream During Events in a Temperate Forested Catchment

NASA Astrophysics Data System (ADS)

Doctor, D. H.; Sebestyen, S. D.; Aiken, G. R.; Shanley, J. B.; Kendall, C.; Boyer, E. W.

2006-12-01

Increased DOC flux in streams and rivers is commonly observed during high runoff regimes, however DOC concentrations alone do not provide information about multiple sources or pathways of DOC to streams. In an effort to gain this information, we measured DOC concentrations and stable carbon isotope composition (δ13C-DOC) on samples collected at high-frequency during events at Sleepers River Research Watershed in Vermont, USA. During snowmelt and storm events, peaks in stream DOC concentration (up to 10.5 mg/L) were coincident with peaks in flow. Stream water δ13C-DOC measurements ranged between -23.7‰ and - 28.9‰ and indicated changing sources of DOC during events; the highest δ13C-DOC values occurred consistently at the lowest flows, and the lowest δ13C-DOC values occurred with peaks in discharge. Water samples collected from shallow wells and stacked soil lysimeters showed the highest DOC concentrations in the most shallow (<0.5 m) lysimeter waters, and the lowest concentrations in the deeper (>1.5 m) well waters. Wells and lysimeters exhibited a range of δ13C-DOC values similar to those observed in the stream; however, samples collected from shallow horizons at nested wells and lysimeters consistently showed lower δ13C-DOC values than those from greater depths. Maple leaf litter collected from across the watershed provided an end-member of fresh organic material, with average δ13C composition of -31.3±0.7‰ (n=57), which is lower than the lowest measured DOC values in any of the stream, well, or lysimeter waters. A subset of stream waters were fractionated onto XAD4 and XAD8 resins; the hydrophobic acid fraction (XAD8) had consistently lower δ13C values than the transphilic acid fraction (XAD4), and both of these were lower than those of the bulk DOC. Samples with lower δ13C-DOC values also exhibited higher SUVA-254 values, i.e. greater aromaticity. Thus, lower δ13C-DOC values are interpreted as an indicator of relatively "fresh", more aromatic and more biologically labile material while higher δ13C-DOC values indicate relatively more degraded material. Since lower δ13C-DOC values were observed in the shallowest well and lysimeter waters and in stream water during periods of highest DOC flux, we surmise that fresh DOC is mobilized to the stream along relatively shallow flowpaths during high flows, and that a second source of more degraded DOC supplies background concentrations to the stream at lower flows.

Heavy metals and polycyclic aromatic hydrocarbons in surface sediments of Karoon River, Khuzestan Province, Iran.

PubMed

Keshavarzi, Behnam; Mokhtarzadeh, Zeinab; Moore, Farid; Rastegari Mehr, Meisam; Lahijanzadeh, Ahmadreza; Rostami, Soqra; Kaabi, Helena

2015-12-01

Karoon is the longest river in Iran and provides water for industries located along its banks, such as metal, petrochemical, and oil industries. It is also the source of drinking water for cities such as Ahwas, Abadan, and Khorramshahr. In this study, 34 and 18 surface sediment samples were collected and analyzed for heavy metals (Al, As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) and polycyclic aromatic hydrocarbons (PAHs). The measured concentrations of heavy metals were compared with US EPA sediment quality guidelines, and the results showed that Cu concentration was above the threshold effect level (TEL) in 65.67% of the samples and Hg concentration was above the effect range median (ERM) in some samples. The results revealed that Hg was severely enriched (5 < enrichment factor < 20) and classified in very high ecological risk index category. It is the major metallic contaminant in the study area. The total PAH concentrations ranged from 11.54-117,730 μg/kg, with the mean value of 7034.55 μg/kg dominated by lower molecular weight (LMW) PAHs. The total potentially carcinogenic PAHs (∑cPAHs) in sediment samples ranged from 2.09 to 31,930 μg/kg, indicating high carcinogenic potential of sediments in the study area. The total toxic equivalent (TEQ) values ranged from 1.06 to 7228.7 μg/kg. Maximum TEQ occurred in Abadan oil refinery station followed by Khorramshahr soap factory and Abadan petrochemical complex. Principal component analysis and cluster analysis also revealed the relationships between the studied parameters and identified their probable sources.

Optical properties of intact leaves for estimating chlorophyll concentration

NASA Technical Reports Server (NTRS)

Carter, Gregory A.; Spiering, Bruce A.

2002-01-01

Changes in leaf chlorophyll content can serve as relative indicators of plant vigor and environmental quality. This study identified reflectance, transmittance, and absorptance wavebands and band ratios within the 400- to 850-nm range for intact leaves that could be used to estimate extracted leaf chlorophyll per unit leaf area (areal concentration) with minimal error. Leaf optical properties along with chlorophyll a, b, and a + b concentrations were measured for the planar-leaved sweetgum (Liquidambar styraciflua L.), red maple (Acer rubrum L.), wild grape (Vitis rotundifolia Michx.), and switchcane [Arundinaria gigantea (Walter) Muhl.], and for needles of longleaf pine (Pinus palustris Miller). Generally, reflectance, transmittance, and absorptance corresponded most precisely with chlorophyll concentrations at wavelengths near 700 nm, although regressions were also strong in the 550- to 625-nm range. A power function was superior to a simple linear function in yielding low standard deviations of the estimate (s). When data were combined among the planar-leaved species, s values were low at approximately 50 mumol/m2 out of a 940 mumol/m2 range in chlorophyll a + b at best-fit wavelengths of 707 to 709 nm. Minimal s values for chlorophyll a + b ranged from 32 to 62 mumol/m2 across species when band ratios having numerator wavelengths of 693 to 720 nm were used with the application of a power function. Optimal denominator wavelengths for the band ratios were 850 nm for reflectance and transmittance and 400 nm for absorptance. This information can be applied in designing field portable chlorophyll meters and in the landscape-scale remote sensing of plant responses to the environment.

Assessing the relative bioavailability of DOC in regional groundwater systems

USGS Publications Warehouse

Chapelle, Francis H.; Bradley, Paul M.; Journey, Celeste A.; McMahon, Peter B.

2013-01-01

It has been hypothesized that the degree to which a hyperbolic relationship exists between concentrations of dissolved organic carbon (DOC) and dissolved oxygen (DO) in groundwater may indicate the relative bioavailability of DOC. This hypothesis was examined for 73 different regional aquifers of the United States using 7745 analyses of groundwater compiled by the National Water Assessment (NAWQA) program of the U.S. Geological Survey. The relative reaction quotient (RRQ), a measure of the curvature of DOC concentrations plotted versus DO concentrations and regressed to a decaying hyperbolic equation, was used to assess the relative bioavailability of DOC. For the basalt aquifer of Oahu, Hawaii, RRQ values were low (0.0013 mM−2), reflecting a nearly random relationship between DOC and DO concentrations. In contrast, on the island of Maui, treated sewage effluent injected into a portion of the basalt aquifer resulted in pronounced hyperbolic DOC-DO behavior and a higher RRQ (142 mM−2). RRQ values for the 73 aquifers correlated positively with mean concentrations of ammonia, dissolved iron, and manganese, and correlated negatively with mean pH. This indicates that greater RRQ values are associated with greater concentrations of the final products of microbial reduction reactions. RRQ values and DOC concentrations were negatively correlated with the thickness of the unsaturated zone (UNST) and depth to the top of the screened interval. Finally, RRQ values were positively correlated with mean annual precipitation (MAP), and the highest observed RRQ values were associated with aquifers receiving MAP rates ranging between 900 and 1300 mm/year. These results are uniformly consistent with the hypothesis that the hyperbolic behavior of DOC-DO plots, as quantified by the RRQ metric, can be an indicator of relative DOC bioavailability in groundwater systems.

Strontium isotope systematics of mixing groundwater and oil-field brine at Goose Lake in northeastern Montana, USA

USGS Publications Warehouse

Peterman, Zell E.; Thamke, Joanna N.; Futa, Kiyoto; Preston, Todd

2012-01-01

Groundwater, surface water, and soil in the Goose Lake oil field in northeastern Montana have been affected by Cl−-rich oil-field brines during long-term petroleum production. Ongoing multidisciplinary geochemical and geophysical studies have identified the degree and local extent of interaction between brine and groundwater. Fourteen samples representing groundwater, surface water, and brine were collected for Sr isotope analyses to evaluate the usefulness of 87Sr/86Sr in detecting small amounts of brine. Differences in Sr concentrations and 87Sr/86Sr are optimal at this site for the experiment. Strontium concentrations range from 0.13 to 36.9 mg/L, and corresponding 87Sr/86Sr values range from 0.71097 to 0.70828. The local brine has 168 mg/L Sr and a 87Sr/86Sr value of 0.70802. Mixing relationships are evident in the data set and illustrate the sensitivity of Sr in detecting small amounts of brine in groundwater. The location of data points on a Sr isotope-concentration plot is readily explained by an evaporation-mixing model. The model is supported by the variation in concentrations of most of the other solutes.

Testing the Underlying Chemical Principles of the Biotic Ligand Model (BLM) to Marine Copper Systems: Measuring Copper Speciation Using Fluorescence Quenching.

PubMed

Tait, Tara N; McGeer, James C; Smith, D Scott

2018-01-01

Speciation of copper in marine systems strongly influences the ability of copper to cause toxicity. Natural organic matter (NOM) contains many binding sites which provides a protective effect on copper toxicity. The purpose of this study was to characterize copper binding with NOM using fluorescence quenching techniques. Fluorescence quenching of NOM with copper was performed on nine sea water samples. The resulting stability constants and binding capacities were consistent with literature values of marine NOM, showing strong binding with [Formula: see text] values from 7.64 to 10.2 and binding capacities ranging from 15 to 3110 nmol mg [Formula: see text] Free copper concentrations estimated at total dissolved copper concentrations corresponding to previously published rotifer effect concentrations, in the same nine samples, were statistically the same as the range of free copper calculated for the effect concentration in NOM-free artificial seawater. These data confirms the applicability of fluorescence spectroscopy techniques for NOM and copper speciation characterization in sea water and demonstrates that such measured speciation is consistent with the chemical principles underlying the biotic ligand model approach for bioavailability-based metals risk assessment.

Validation of a LC/MS method for the determination of gemfibrozil in human plasma and its application to a pharmacokinetic study

PubMed Central

Rower, Joseph E.; Bushman, Lane R.; Hammond, Kyle P.; Kadam, Rajendra S.; Aquilante, Christina L.

2011-01-01

Gemfibrozil, a fibric acid hypolipidemic agent, is increasingly being used in clinical drug-drug interaction studies as an inhibitor of drug metabolizing enzymes and drug transporters. The validation of a fast, accurate, and precise LC/MS method is described for the quantitative determination of gemfibrozil in an EDTA-anticoagulated human plasma matrix. Briefly, gemfibrozil was extracted from human plasma by an acetonitrile protein precipitation method. The assay was reproducible with intra-assay precision between 1.6% and 10.7%, and inter-assay precision ranging from 4.4% to 7.8%. The assay also showed good accuracy, with intra-assay concentrations within 85.6% and 108.7% of the expected value, and inter-assay concentrations within 89.4 to 104.0% of the expected value. The linear concentration range was between 0.5 and 50 μg/mL with a lower limit of quantitation of 0.5 μg/mL when 125 μL of plasma were extracted. This LC/MS method yielded a quick, simple, and reliable protocol for determining gemfibrozil concentrations in plasma and is applicable to clinical pharmacokinetic studies. PMID:21077249

Validation of an LC/MS method for the determination of gemfibrozil in human plasma and its application to a pharmacokinetic study.

PubMed

Rower, Joseph E; Bushman, Lane R; Hammond, Kyle P; Kadam, Rajendra S; Aquilante, Christina L

2010-12-01

Gemfibrozil, a fibric acid hypolipidemic agent, is increasingly being used in clinical drug-drug interaction studies as an inhibitor of drug metabolizing enzymes and drug transporters. The validation of a fast, accurate and precise LC/MS method is described for the quantitative determination of gemfibrozil in an EDTA-anticoagulated human plasma matrix. Briefly, gemfibrozil was extracted from human plasma by an acetonitrile protein precipitation method. The assay was reproducible with intra-assay precision between 1.6 and 10.7%, and inter-assay precision ranging from 4.4 to 7.8%. The assay also showed good accuracy, with intra-assay concentrations within 85.6-108.7% of the expected value, and inter-assay concentrations within 89.4-104.0% of the expected value. The linear concentration range was between 0.5 and 50 µg/mL with a lower limit of quantitation of 0.5 µg/mL when 125 µL of plasma were extracted. This LC/MS method yielded a quick, simple and reliable protocol for determining gemfibrozil concentrations in plasma and is applicable to clinical pharmacokinetic studies. Copyright © 2010 John Wiley & Sons, Ltd.

Geochemical Indicators of Nitrogen flow in a Check-Dam Catchment in the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Wang, Y.; Chen, S.; Huang, Y.; Gao, Y.

2017-12-01

The increasingly fragile ecological environment and associative nitrogen (N) biogeochemical cycle have become critical environmental and ecological issues in China's Loess Plateau. However, N flow and N source for typical catchments remains poorly understood in the Loess Plateau. In this study, we measured concentrations and isotopic signatures of N, hydrogen (H), and oxygen (O) in both rainfall and river water. Results showed that baseflow variation in total nitrogen (TN) concentrations ranged from 0.16 to 32.70 mg·L-1. Monthly TN deposition and monthly N wet deposition concentrations to river water were from 0.05 to 2.91 kg·hm-2 and from 0.28 to 11.26 kg, respectively, with significant variations between rainy and dry seasons. The range of variation in δ2H values for rainfall and baseflow were from -90.0‰ to +19.8‰ and from -67.2‰ to -38.4‰, respectively, while δ18O-H2O values ranged from -12.1‰ to +2.7‰ and from -9.3‰ to -3.6‰, respectively. Furthermore, NO3- δ15N and δ18O values in baseflow ranged from -2.0‰ to +20.5‰ and from +8.0‰ to +15.6‰, respectively. The results indicated that rainfall was affected by below-cloud secondary evaporation and caused strong isotopic kinetic fractionation to occur during the falling process. The NO3-in runoff mainly derived from the nitrification of soil organic matter (SOM), for which the proportion of manure or sewage was from 50.5% to 83%.

Hypoglycemia in a dog with a leiomyoma of the gastric wall producing an insulin-like growth factor II-like peptide.

PubMed

Boari, A; Barreca, A; Bestetti, G E; Minuto, F; Venturoli, M

1995-06-01

A 12-year-old mixed-breed male dog was referred to the Clinica Medica Veterinaria of Bologna University for recurrent episodes of seizures due to hypoglycemia with abnormally low plasma insulin levels (18 pmol/l). Resection of a large leiomyoma (780 g) of the gastric wall resulted in a permanent resolution of the hypoglycemic episodes. Insulin-like growth factors I and II (IGF-I and -II) were measured by RIA in serum before and after surgery and in tumor tissue. Results were compared to the serum concentration of 54 normal and to the tissue concentration observed in eight non-hypoglycemic dog gastric wall extracts. Before surgery, circulating immunoreactive IGF-I was 0.92 nmol/l, which is significantly lower than the control values (16.92 +/- 8.44 nmol/l, range 3.53-35.03), while IGF-II was 152 nmol/l, which is significantly higher than the control values (42.21 +/- 3.75, range 31.99-50.74). After surgery, IGF-I increased to 6.80 nmol/l while IGF-II decreased to 45.52 nmol/l. Tumor tissue IGF-II concentration was higher than normal (5.66 nmol/kg tissue as compared to a range in normal gastric wall tissue of 1.14-3.72 nmol/kg), while IGF-I was 0.08 nmol/kg tissue, which is close to the lowest normal value (range in controls, 0.08-1.18 nmol/kg). Partial characterization of IGF-II immunoreactivity extracted from tissue evidenced a molecular weight similar to that of mature IGF-II, thus excluding that peptide released by the tumor is a precursor molecule.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of tank 38H (HTF-38-17-18, -19) and tank 43H (HTF-43-17-20, -21) samples for support of the enrichment control and corrosion control programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hay, M. S.; Coleman, C. J.; Diprete, D. P.

SRNL analyzed samples from Tank 38H and Tank 43H to support ECP and CCP. The total uranium in the Tank 38H samples ranged from 53.7 mg/L for the surface sample to 57.0 mg/L in the sub-surface sample. The Tank 43H samples showed uranium concentrations of 46.2 mg/L for the surface sample and 45.7 mg/L in the sub-surface sample. The U-235 percentage was 0.63% in the Tank 38H samples and 0.62% in the Tank 43H samples. The total uranium and percent U-235 results appear consistent with recent Tank 38H and Tank 43H uranium measurements. The plutonium results for the Tank 38Hmore » surface sample are slightly higher than recent sample results, while the Tank 43H plutonium results are within the range of values measured on previous samples. The Cs-137 results for the Tank 38H surface and subsurface samples are slightly higher than the concentrations measured in recent samples. The Cs-137 results for the two Tank 43H samples are within the range of values measured on previous samples. The comparison of the sum of the cations in each sample versus the sum of the anions shows a difference of 23% for the Tank 38H surface sample and 18% for the Tank 43H surface sample. The four samples show silicon concentrations somewhat lower than the previous samples with values ranging from 80.2 to 105 mg/L.« less

Segregation of Impurities in Directionally Solidified Silicon

NASA Technical Reports Server (NTRS)

Ravishankar, P. S.; Younghouse, L. B.

1984-01-01

Hall measurements and four-point probe resistivity measurements are used to determine the concentration profile of boron and iron in doped semi-conductor silicon ingots grown by the Bridgman technique. The concentration profiles are fitted to the normal segregation equation and the effective segregation coefficient, K sub eff, is calculated. The average value of K sub eff, is 0.803 for boron. For iron, K sub eff, is concentration dependent and is in the range 0.00008 to 0.00012.

Effect of parvoviral enteritis on plasma citrulline concentration in dogs.

PubMed

Dossin, O; Rupassara, S I; Weng, H-Y; Williams, D A; Garlick, P J; Schoeman, J P

2011-01-01

Plasma citrulline concentration is a reliable marker of global enterocyte mass in humans and is markedly decreased in diffuse small intestinal diseases. However, the relationship between acute intestinal damage and plasma citrulline concentration in dogs has never been documented. That dogs with parvoviral enteritis have a lower plasma citrulline concentration than healthy dogs and that plasma citrulline concentration is a predictor of death in puppies with parvoviral enteritis. Sixty-one dogs with spontaneous parvoviral enteritis and 14 healthy age-matched control dogs. Observational cohort study. Plasma citrulline concentration was measured by liquid chromatography and tandem mass spectrometry in blood samples collected at admission and each day until death or discharge from the hospital. Parvovirus enteritis was confirmed by electron microscopy on a fecal sample. Median (interquartile range) plasma citrulline concentrations at admission were 2.8 μmol/L (range: 0.3, 49.0; P < .001 versus controls) in survivors (n = 49), 2.1 μmol/L (range: 0.5, 6.4, P < .001 versus controls) in nonsurvivors (n = 12) and 38.6 μmol/L (range: 11.4, 96.1) in controls (n = 14), respectively. There was no significant difference in plasma citrulline concentration between survivors and nonsurvivors within the parvovirus-infected puppies, and plasma citrulline concentration was not significantly associated with outcome in parvoviral enteritis. There were no significant changes in plasma citrulline concentration over the 8-day follow-up period. Parvovirus enteritis is associated with a severe decrease in plasma citrulline concentration that does not appear to have any significant prognostic value. Copyright © 2011 by the American College of Veterinary Internal Medicine.

The PM2.5 threshold for aerosol extinction in the Beijing megacity

NASA Astrophysics Data System (ADS)

Kong, Lingbin; Xin, Jinyuan; Liu, Zirui; Zhang, Kequan; Tang, Guiqian; Zhang, Wenyu; Wang, Yuesi

2017-10-01

Particulate pollution has remained at a high level in the megacity of Beijing in the past decade. The PM2.5, PM10, aerosol optical depth (AOD), Angstrom exponent(α), and PM2.5/PM10 ratio (the proportion of PM2.5 in PM10) in Beijing were 70±6 μg m-3, 128±6 μg m-3, 0.57 ± 0.05, 1.10 ± 0.08, 45 ± 4%, respectively, from 2005 to 2014. The annual means of PM concentration, AOD, α, and PM2.5/PM10 ratio decreased slightly during this decade, meanwhile PM concentration increased in the winter. Furthermore, we found there were thresholds of PM2.5 concentration for aerosol extinction. When the PM concentration was lower than a certain threshold, AOD decreased quickly with the decline of PM concentration. To make the improvement of the particle pollution more noticeable, the PM concentration should be controlled under the threshold. The annual averaged threshold is 63 μg m-3, and the threshold values reached the maximum of 74 μg m-3 in spring, ranged from 54 to 56 μg m-3 in the three other seasons. The threshold values ranged from 55 to 77 μg m-3 under other relevant factors, including air masses directions and relative humidity.

Pb concentrations and isotopic record preserved in northwest Greenland snow.

PubMed

Kang, Jung-Ho; Hwang, Heejin; Han, Changhee; Hur, Soon Do; Kim, Seong-Joong; Hong, Sungmin

2017-11-01

We present high-resolution lead (Pb) concentrations and isotopic ratios from a northwest Greenland snow pit covering a six-year period between 2003 and 2009. Pb concentrations ranged widely from 2.7 pg g -1 to 97.3 pg g -1 , with a mean concentration of 21.6 pg g -1 . These values are higher than those recorded for the pre-industrial period. Pb concentrations exhibit seasonal spikes in winter-spring layers. Crustal Pb enrichment factors (EF) suggest that the northwest Greenland snow pit is highly enriched with Pb of predominantly anthropogenic origin. The 206 Pb/ 207 Pb ratios ranged from 1.144 to 1.169 with a mean value of 1.156, which fall between less radiogenic Eurasian-type and more radiogenic Canadian-type signatures. This result suggests that several potential source areas of Pb impact on northwest Greenland. Abrupt changes in Pb concentrations and Pb isotope ratios were observed and related to seasonal shifts in source regions of aerosol transport. The 206 Pb/ 207 Pb isotope ratio increased gradually between 2003 and 2009. The similarity of the three-isotope plot ( 206 Pb/ 207 Pb versus 208 Pb/ 207 Pb) between some of our samples and Chinese urban aerosols suggests a steadily increasing contribution of Chinese Pb to northwest Greenland snow. Copyright © 2017. Published by Elsevier Ltd.

Origin of rainwater acidity near the Los Azufres geothermal field, Mexico

USGS Publications Warehouse

Verma, M.P.; Quijano, J.L.; Johnson, Chad; Gerardo, J.Y.; Arellano, V.

2000-01-01

The chemical and isotopic compositions of rainwater were monitored at Los Azufres geothermal field (88 MWe) and its surroundings during May - September 1995, which is the rainy season. Samples were collected from eight sites: three within the field, three in its surroundings and two sufficiently far from the field such that they have no geothermal input. The concentrations of Cl-, SO42- and NO3- were measured in about 350 samples and found to be generally <5 ppm. Chloride concentrations remained constant with time, but sulfate and nitrate concentrations decreased, which suggests a nearby industrial source for the sulfate and nitrate. A mixing model for Cl-, SO42- and ??34S also suggests an industrial source for the rainwater sulfur. The determination of pH was found to be necessary, but is not sufficient to characterize rainwater acidity. The Gran titration method was used to determine alkalinity with respect to equivalence point of H2CO3(*). Values of alkalinity were found to range from 10-4 to 10-6 eq/L, and were negative only for some samples from Vivero and Guadalajara. Thus, SO42- and NO3- are in general not in acidic form (i.e. balanced by Na+, Ca2+, etc. rather than H+). Sulfate ??34S values were about -1.5??? in Los Azufres and its surroundings, and in Morelia, but differed from the value of -0.2??? for Guadalajara. The ??34S values for H2S from the Los Azufres geothermal wells are in the range -3.4 to 0.0???. The ??34S ranges for the natural and anthropogenic sources for environmental sulfur overlap, making it difficult to differentiate between the contribution of different sources. However, a similarity of values of ??34S at Los Azufres and Morelia (85 km distant) suggest a regional source of sulfate that is not associated with geothermal emissions from Los Azufres. (C) 2000 Published by Elsevier Science Ltd on behalf of CNR.The chemical compositions of rainwater were analyzed at Los Azufres geothermal field in Spain from May-September 1995. The concentrations of Cl-, SO42- and NO3- were measured and found to be generally <5 ppm. Chloride concentrations remained constant with time, but sulfate and nitrate concentrations decreased, suggesting a nearby industrial source. A mixing model for Cl-, SO42-, and ??34S also suggested an industrial source for the rainwater sulfur.

Accuracy of the raw-data-based effective atomic numbers and monochromatic CT numbers for contrast medium with a dual-energy CT technique.

PubMed

Kawahara, Daisuke; Ozawa, Shuichi; Yokomachi, Kazushi; Tanaka, Sodai; Higaki, Toru; Fujioka, Chikako; Suzuki, Tatsuhiko; Tsuneda, Masato; Nakashima, Takeo; Ohno, Yoshimi; Nagata, Yasushi

2018-02-01

To evaluate the accuracy of raw-data-based effective atomic number (Z eff ) values and monochromatic CT numbers for contrast material of varying iodine concentrations, obtained using dual-energy CT. We used a tissue characterization phantom and varying concentrations of iodinated contrast medium. A comparison between the theoretical values of Z eff and that provided by the manufacturer was performed. The measured and theoretical monochromatic CT numbers at 40-130 keV were compared. The average difference between the Z eff values of lung (inhale) inserts in the tissue characterization phantom was 81.3% and the average Z eff difference was within 8.4%. The average difference between the Z eff values of the varying concentrations of iodinated contrast medium was within 11.2%. For the varying concentrations of iodinated contrast medium, the differences between the measured and theoretical monochromatic CT values increased with decreasing monochromatic energy. The Z eff and monochromatic CT numbers in the tissue characterization phantom were reasonably accurate. The accuracy of the raw-data-based Z eff values was higher than that of image-based Z eff values in the tissue-equivalent phantom. The accuracy of Z eff values in the contrast medium was in good agreement within the maximum SD found in the iodine concentration range of clinical dynamic CT imaging. Moreover, the optimum monochromatic energy for human tissue and iodinated contrast medium was found to be 70 keV. Advances in knowledge: The accuracy of the Z eff values and monochromatic CT numbers of the contrast medium created by raw-data-based, dual-energy CT could be sufficient in clinical conditions.

{sup 40}K, {sup 115}Cs and {sup 226}Ra Soil and Plant Content in Seminatural Grasslands of Central Argentina

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ayub, J. Juri; Velasco, R. H.; Rizzotto, M.

2008-08-07

Activity concentrations of {sup 40}K, {sup 226}Ra and {sup 137}Cs have been analyzed in soil and plant samples, collected in permanent grassland in central Argentina. Two near areas (A1 and A2) under field conditions with soil undisturbed at least in the last four decades were selected. For each of the three studied radionuclides we do not find differences in the inventories between both areas. The inventories range from 143 kBq m{sup -2} to 197 kBq m{sup -2} for {sup 40}K and from 13 kBq m{sup -2} to 18 kBq m{sup -2} for {sup 226}Ra. The vertical distributions of {sup 40}Kmore » and {sup 226}Ra are uniform through de soil profile. For {sup 137}Cs the inventories range from 0.33 kBq m{sup -2} to 0.73 kBq m{sup -2}. In spite of {sup 137}Cs inventories are similar in both areas the distribution through vertical profile is different. {sup 137}Cs activity concentration has a maximum for layers 5-10 cm depth in A1 and 10-15 cm depth in A2. For deeper layers both areas show similar activity concentrations. The diffusion coefficient (D{sub s}) and convection velocity (v{sub s}) are estimated with a convection-diffusion model. D{sub s} values are in the range reported in the bibliography, while v{sub s} values are one order of magnitude higher. After 40 years most {sup 137}Cs fallout is still in the layer 10-15 cm depth. The great penetration of {sup 137}Cs (25 cm) in these soils may be the result of a high sand and low fine materials content. {sup 137}Cs and {sup 226}Ra were not detected in grass samples. Activity concentration of {sup 40}K in vegetal samples ranges from 116 Bq kg{sup -1} to 613 Bq kg{sup -1}. The TF values obtained for {sup 40}K show a lognormal distribution and ranges from 0.05 to 0.42.« less

Using a Hazard Quotient to Evaluate Pesticide Residues Detected in Pollen Trapped from Honey Bees (Apis mellifera) in Connecticut

PubMed Central

Stoner, Kimberly A.; Eitzer, Brian D.

2013-01-01

Analysis of pollen trapped from honey bees as they return to their hives provides a method of monitoring fluctuations in one route of pesticide exposure over location and time. We collected pollen from apiaries in five locations in Connecticut, including urban, rural, and mixed agricultural sites, for periods from two to five years. Pollen was analyzed for pesticide residues using a standard extraction method widely used for pesticides (QuEChERS) and liquid chromatography/mass spectrometric analysis. Sixty pesticides or metabolites were detected. Because the dose lethal to 50% of adult worker honey bees (LD50) is the only toxicity parameter available for a wide range of pesticides, and among our pesticides there were contact LD50 values ranging from 0.006 to >1000 μg per bee (range 166,000X), and even among insecticides LD50 values ranged from 0.006 to 59.8 μg/bee (10,000X); therefore we propose that in studies of honey bee exposure to pesticides that concentrations be reported as Hazard Quotients as well as in standard concentrations such as parts per billion. We used both contact and oral LD50 values to calculate Pollen Hazard Quotients (PHQ = concentration in ppb ÷ LD50 as μg/bee) when both were available. In this study, pesticide Pollen Hazard Quotients ranged from over 75,000 to 0.01. The pesticides with the greatest Pollen Hazard Quotients at the maximum concentrations found in our study were (in descending order): phosmet, Imidacloprid, indoxacarb, chlorpyrifos, fipronil, thiamethoxam, azinphos-methyl, and fenthion, all with at least one Pollen Hazard Quotient (using contact or oral LD50) over 500. At the maximum rate of pollen consumption by nurse bees, a Pollen Hazard Quotient of 500 would be approximately equivalent to consuming 0.5% of the LD50 per day. We also present an example of a Nectar Hazard Quotient and the percentage of LD50 per day at the maximum nectar consumption rate. PMID:24143241

Using a hazard quotient to evaluate pesticide residues detected in pollen trapped from honey bees (Apis mellifera) in Connecticut.

PubMed

Stoner, Kimberly A; Eitzer, Brian D

2013-01-01

Analysis of pollen trapped from honey bees as they return to their hives provides a method of monitoring fluctuations in one route of pesticide exposure over location and time. We collected pollen from apiaries in five locations in Connecticut, including urban, rural, and mixed agricultural sites, for periods from two to five years. Pollen was analyzed for pesticide residues using a standard extraction method widely used for pesticides (QuEChERS) and liquid chromatography/mass spectrometric analysis. Sixty pesticides or metabolites were detected. Because the dose lethal to 50% of adult worker honey bees (LD50) is the only toxicity parameter available for a wide range of pesticides, and among our pesticides there were contact LD50 values ranging from 0.006 to >1000 μg per bee (range 166,000X), and even among insecticides LD50 values ranged from 0.006 to 59.8 μg/bee (10,000X); therefore we propose that in studies of honey bee exposure to pesticides that concentrations be reported as Hazard Quotients as well as in standard concentrations such as parts per billion. We used both contact and oral LD50 values to calculate Pollen Hazard Quotients (PHQ = concentration in ppb ÷ LD50 as μg/bee) when both were available. In this study, pesticide Pollen Hazard Quotients ranged from over 75,000 to 0.01. The pesticides with the greatest Pollen Hazard Quotients at the maximum concentrations found in our study were (in descending order): phosmet, Imidacloprid, indoxacarb, chlorpyrifos, fipronil, thiamethoxam, azinphos-methyl, and fenthion, all with at least one Pollen Hazard Quotient (using contact or oral LD50) over 500. At the maximum rate of pollen consumption by nurse bees, a Pollen Hazard Quotient of 500 would be approximately equivalent to consuming 0.5% of the LD50 per day. We also present an example of a Nectar Hazard Quotient and the percentage of LD50 per day at the maximum nectar consumption rate.

Rapid Determination of Surfactant Critical Micelle Concentrations Using Pressure-Driven Flow with Capillary Electrophoresis Instrumentation

PubMed Central

Stanley, F. E.; Warner, A. M.; Schneiderman, E.; Stalcup, A. M.

2009-01-01

This work demonstrates a novel, convenient utilization of capillary electrophoresis (CE) instrumentation for the determination of critical micelle concentrations (CMCs). Solution viscosity differences across a range of surfactant concentrations were monitored by hydrodynamically forcing an analyte towards the detector. Upon reaching the surfactant's CMC value, migration times were observed to change drastically. CMC values for four commonly employed anionic surfactants were determined - sodium dodecyl sulfate: 8.1 mM; sodium caprylate- 300 mM; sodium decanoate- 86 mM; sodium laurate- 30 mM; and found to be in excellent agreement with values previously reported in the literature. The technique was then applied to the less well-characterized nonionic surfactants poly(oxyethylene) 8 myristyl ether (CMC ~ 9 μM), poly(oxyethylene) 8 decyl ether (CMC ~ 0.95 mM) and poly(oxyethylene) 4 lauryl ether. PMID:19836753

Evaluation of the pH- and Thermal Stability of the Recombinant Green Fluorescent Protein (GFP) in the Presence of Sodium Chloride

NASA Astrophysics Data System (ADS)

Ishii, Marina; Kunimura, Juliana Sayuri; Jeng, Hélio Tallon; Vessoni Penna, Thereza Christina; Cholewa, Olivia

The thermal stability of recombinant green fluorescent protein (GFP) in sodium chloride (NaCl) solutions at different concentrations, pH, and temperatures was evaluated by assaying the loss of fluorescence intensity as a measure of denaturation. GFP, extracted from Escherichia coli cells by the three-phase partitioning method and purified through a butyl hydrophobic interaction chromatography (HIC) column, was diluted in water for injection (WFI) (pH 6.0-7.0) and in 10 mM buffer solutions (acetate, pH 5.0; phosphate, pH 7.0; and Tris-EDTA, pH 8.0) with 0.9-30% NaCl or without and incubated at 80-95°C. The extent of protein denaturation was expressed as a percentage of the calculated decimal reduction time (D-value). In acetate buffer (pH 4.84 ±0.12), the mean D-values for 90% reduction in GFP fluorescence ranged from 2.3 to 3.6 min, independent of NaCl concentration and temperature. GFP thermal stability diluted in WFI (pH 5.94±0.60) was half that observed in phosphate buffer (pH 6.08±0.60); but in both systems, D-values decreased linearly with increasing NaCl concentration, with D-values (at 80°C) ranging from 3.44, min (WFI) to 6.1 min (phosphate buffer), both with 30% NaCl. However, D-values in Tris-EDTA (pH 7.65±0.17) were directly dependent on the NaCl concentration and 5-10 times higher than D-values for GFP in WFI at 80°C. GFP pH-and thermal stability can be easily monitored by the convenient measure of fluorescence intensity and potentially be used as an indicator to monitor that processing times and temperatures were attained.

Assessing the Impact of Analytical Error on Perceived Disease Severity.

PubMed

Kroll, Martin H; Garber, Carl C; Bi, Caixia; Suffin, Stephen C

2015-10-01

The perception of the severity of disease from laboratory results assumes that the results are free of analytical error; however, analytical error creates a spread of results into a band and thus a range of perceived disease severity. To assess the impact of analytical errors by calculating the change in perceived disease severity, represented by the hazard ratio, using non-high-density lipoprotein (nonHDL) cholesterol as an example. We transformed nonHDL values into ranges using the assumed total allowable errors for total cholesterol (9%) and high-density lipoprotein cholesterol (13%). Using a previously determined relationship between the hazard ratio and nonHDL, we calculated a range of hazard ratios for specified nonHDL concentrations affected by analytical error. Analytical error, within allowable limits, created a band of values of nonHDL, with a width spanning 30 to 70 mg/dL (0.78-1.81 mmol/L), depending on the cholesterol and high-density lipoprotein cholesterol concentrations. Hazard ratios ranged from 1.0 to 2.9, a 16% to 50% error. Increased bias widens this range and decreased bias narrows it. Error-transformed results produce a spread of values that straddle the various cutoffs for nonHDL. The range of the hazard ratio obscures the meaning of results, because the spread of ratios at different cutoffs overlap. The magnitude of the perceived hazard ratio error exceeds that for the allowable analytical error, and significantly impacts the perceived cardiovascular disease risk. Evaluating the error in the perceived severity (eg, hazard ratio) provides a new way to assess the impact of analytical error.

Carbon monoxide degassing from seismic fault zones in the Basin and Range province, west of Beijing, China

NASA Astrophysics Data System (ADS)

Sun, Yutao; Zhou, Xiaocheng; Zheng, Guodong; Li, Jing; Shi, Hongyu; Guo, Zhengfu; Du, Jianguo

2017-11-01

Degassing of carbon monoxide (CO), which plays a significant role in the contribution of deep carbon to the atmosphere, commonly occurs within active fault zones. CO degassing from soil to the atmosphere in the Basin and Range province, west of Beijing (BRPB), China, was investigated by in-situ field measurements in the active fault zones. The measured concentrations of CO in soil gas in the BRPB ranged from 0.29 × 10-6 to 1.1 × 10-6 with a mean value of 0.6 × 10-6, which is approximately twice as large as that in the atmosphere. Net fluxes of CO degassing ranged from -48.6 mg m-2 d-1 to 12.03 mg m-2 d-1. The diffusion of CO from soil to the atmosphere in the BRPB was estimated to be at least 7.6 × 103 ton/a, which is comparable to the corresponding result of about 1.2 × 104 ton/a for CO2. CO concentrations were spatially heterogeneous with clearly higher concentrations along the NE-SW trending in the BRPB. These elevated values of CO concentrations were also coincident with the region with low-velocity and high conductivity in deep mantle, and high Poisson's ratio in the crust, thereby suggesting that CO degassing from the soil might be linked to upwelling of the asthenospheric mantle. Other sources of CO in the soil gas are suggested to be dominated by chemical reactions between deep fluids and carbonate minerals (e.g., dolomite, limestone, and siderite) in country rocks. Biogenic processes may also contribute to the CO in soil gas. The spatial distribution patterns of CO concentrations are coincident with the stress field, suggesting that the concentrations of CO could be a potential indicator for crustal stress field and, hence is potential useful for earthquake monitoring in the BRPB.

Zeta potential response of human erythrocyte membranes to the modulators of Gardos channel activity under low rate β-radiation.

PubMed

Zhirnov, V V; Iakovenko, I N; Voitsitskiy, V M; Khyzhnyak, S V; Zubrikova-Chugainova, O G; Gorobetz, V A

2015-12-01

Study of human erythrocyte DP response under modification by activators and blockers of the functional state of Ca2+-dependent K+ channels under low rate β-radiation. Erythrocytes were isolated from the donor blood. The zeta potential was computed from the value of the cell electrophoretic mobility. The investigated drugs preliminary introduced in cellular suspensions, and then aliquote of 90Sr(NO3)2 solution to get the final activity concentration of 44,4kBq⋅l-1. The radioisotope radiation of 90Sr/90Y (RR, 15 μGy⋅h-1) increases an absolute value of erythrocyte membranes DP (DPab), and its action is reversible. It specifies the effect is mediated by non-ionizing part of the RR. Dibutyril-cAMP dose-independent increases DPab of erythrocyte membranes in the concentration range of 1-100 мкМ, but RR does not amplify this effect. Anaprilin increases dose-independent DPab in concentrations 10 and 100 μМ. The effect of maximal concentration of anaprilin (100 μМ) decreases by RR. Clotrimazol increases DPab of erythrocyte membranes in the concentration range of 0,1-10 μМ relatively control, while its maximal concentration - decreases, and the minimal level does not reliably influence on this index The action of сlotrimazol on DP in concentrations of 10-100 μМ is abolished by RR, and is not changed in the range of 0,1-1,0 μМ. Nitrendipine raises DPab of erythrocyte membranes in all of range of concentrations, and RR amplifies the effect of the drug. 1. There is a threshold of the biological action on cells for the ionizing component of radioisotope radiation determined by efficiency of operation their antioxidant system.2. At dose rates below a threshold, the action of ionizing radiation is mediated by its non-ionizing component, and is reversible, and therefore is determined only in the field of radiation. V. V. Zhirnov, I. N. Iakovenko, V.M. Voitsitskiy, S. V. Khyzhnyak, О. G. Zubrikova-Chugainova, V.A. Gorobetz.

Factors affecting the viscosity of sodium hypochlorite and their effect on irrigant flow.

PubMed

Bukiet, F; Soler, T; Guivarch, M; Camps, J; Tassery, H; Cuisinier, F; Candoni, N

2013-10-01

To assess the influence of concentration, temperature and surfactant addition to a sodium hypochlorite solution on its dynamic viscosity and to calculate the corresponding Reynolds number to determine the corresponding flow regimen. The dynamic viscosity of the irrigant was assessed using a rotational viscometer. Sodium hypochlorite with concentrations ranging from 0.6% to 9.6% was tested at 37 and 22 °C. A wide range of concentrations of three different surfactants was mixed in 2.4% sodium hypochlorite for viscosity measurements. The Reynolds number was calculated under each condition. Data were analysed using two-way anova. There was a significant influence of sodium hypochlorite concentration (P < 0.001) and temperature (P < 0.001) on dynamic viscosity: the latter significantly increased with sodium hypochlorite concentration and decreased with temperature. A significant influence of surfactant concentration on dynamic viscosity (P < 0.001) occurred, especially for high surfactant concentrations: 6.25% for benzalkonium chloride, 15% for Tween 80 and 6.25% for Triton X-100. Reynolds number values calculated for a given flow rate (0.14 mL s(-1)), and root canal diameter (sizes 45 and 70) clearly qualified the irrigant flow regimen as laminar. Dynamic viscosity increased with sodium hypochlorite and surfactant concentration but decreased with temperature. Under clinical conditions, all viscosities measured led to laminar flow. The transition between laminar and turbulent flow may be reached by modifying different parameters at the same time: increasing flow rate and temperature whilst decreasing irrigant viscosity by adding surfactants with a high value of critical micellar concentration. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Probing water dynamics with OH -

NASA Astrophysics Data System (ADS)

Corridoni, T.; Sodo, A.; Bruni, F.; Ricci, M. A.; Nardone, M.

2007-07-01

Isotropic Raman spectra of aqueous solutions of LiOH, NaOH and KOH at concentrations ranging from high dilution to saturation have been measured and the frequency and width of the OH - stretching band have been analyzed. The dependence of the bandwidth on solute concentration suggests that the OH - vibration undergoes a transition from fast to slow modulation regimes as the solvent concentration decreases below the value of ˜20 water molecules per solute molecule. A correlation between this finding and structural modifications of the H-bond network of the solvent at similar concentrations is envisaged.

Water Quality Assessment of the Los Angeles River Watershed, California, USA in Wet and Dry Weather Periods

NASA Astrophysics Data System (ADS)

Rezaie Boroon, M. H.; Von L Coo, C.

2015-12-01

The purpose of this study is to identify sources of potential pollutants and characterize urban water quality along the Los Angeles River from its head to the mouth during dry and wet weather periods. Los Angeles (LA) River flows through heavily populated urbanized area in the Los Angeles downtown. The LA River is an effluent-dominated water body during the dry season. The three waste water treatment plants (WWTP) including the Tillman, Burbank, and Glendale discharge the majority of the volume flowing in the LA River during the dry and wet period. The concentration values (ppm) for anions in the dry season ranging 5.5-16,027 (Cl), 0-1.0 (F), 0-21(NO3), 0-1.6 (PO4), and 13.3-2,312 (SO4); whereas the values (ppm) for anions in the wet season ranging 3.4-5,860 (Cl), 0-0.66 (F), 0-17 (NO3), 0-0.67 (PO4), 7.9- 745 (SO4). Dry season concentrations values for trace metals were obtained with values (ppb) ranging 0.9-10 (Ni), 0.8-62 (Zn), 1-4 (As), 0-1 (Pb) and 0-3 (Se). As for wet season trace metals (ppb) ranging 0.001-0.008 (Ni), 0.000001-0.038 (Zn), 0.0016-0.016 (As), 0.00099-0.0058 (Pb), 0.000001-0.0093 (Se). Higher concentrations values during the dry period in the LA River watershed may be attributed to the three WWTPs discharge (75% of the volume of water flowing in the LA River). In water-limited areas such as the Los Angeles basin, urban runoff is a water resource that could enhance restricted water supplies and to enhance localized renewable groundwater resources, thus an assessment of this precious water resource is important for local city and regulatory organizations. In water-limited areas such as the LA basin, urban runoff is a water resource that could enhance restricted water supplies and groundwater resources, thus an assessment of this precious water resource is important for local regulatory organizations.

Underground and ground-level particulate matter concentrations in an Italian metro system

NASA Astrophysics Data System (ADS)

Cartenì, Armando; Cascetta, Furio; Campana, Stefano

2015-01-01

All around the world, many studies and experimental results have assessed elevated concentrations of Particulate Matter (PM) in underground metro systems, with non-negligible implications for human health due to protracted exposure to fine particles. Starting from this consideration, an intensive particulate sampling campaign was carried out in January 2014 measuring the PM concentrations in the Naples (Italy) Metro Line 1, both at station platforms and inside trains. Naples Metro Line 1 is about 18 km long, with 17 stations (3 ground-level and 14 below-ground ones). Experimental results show that the average PM10 concentrations measured in the underground station platforms range between 172 and 262 μg/m3 whilst the average PM2.5 concentrations range between 45 and 60 μg/m3. By contrast, in ground-level stations no significant difference between stations platforms and urban environment measurements was observed. Furthermore, a direct correlation between trains passage and PM concentrations was observed, with an increase up to 42% above the average value. This correlation is possibly caused by the re-suspension of the particles due to the turbulence induced by trains. The main original finding was the real-time estimations of PM levels inside the trains travelling both in ground-level and underground sections of Line 1. The results show that high concentrations of both PM10 (average values between 58 μg/m3 and 138 μg/m3) and PM2.5 (average values between 18 μg/m3 and 36 μg/m3) were also measured inside trains. Furthermore, measurements show that windows left open on trains caused the increase in PM concentrations inside trains in the underground section, while in the ground-level section the clean air entering the trains produced an environmental "washing effect". Finally, it was estimated that every passenger spends on average about 70 min per day exposed to high levels of PM.

Quantification of hair cortisol concentration in common marmosets (Callithrix jacchus) and tufted capuchins (Cebus apella).

PubMed

Phillips, Kimberley A; Tukan, Alyson N; Rigodanzo, Anna D; Reusch, Ryan T; Brasky, Kathleen M; Meyer, Jerrold S

2018-06-04

Quantifying cortisol concentration in hair is a non-invasive biomarker of long-term hypothalamic-pituitary-adrenal (HPA) activation, and thus can provide important information on laboratory animal health. Marmosets (Callithrix jacchus) and capuchins (Cebus apella) are New World primates increasingly used in biomedical and neuroscience research, yet published hair cortisol concentrations for these species are limited. Review of the existing published hair cortisol values from marmosets reveals highly discrepant values and the use of variable techniques for hair collection, processing, and cortisol extraction. In this investigation we utilized a well-established, standardized protocol to extract and quantify cortisol from marmoset (n = 12) and capuchin (n = 4) hair. Shaved hair samples were collected from the upper thigh during scheduled exams and analyzed via methanol extraction and enzyme immunoassay. In marmosets, hair cortisol concentration ranged from 2,710 to 6,267 pg/mg and averaged 4,070 ± 304 pg/mg. In capuchins, hair cortisol concentration ranged from 621 to 2,089 pg/mg and averaged 1,092 ± 338 pg/mg. Hair cortisol concentration was significantly different between marmosets and capuchins, with marmosets having higher concentrations than capuchins. The incorporation of hair cortisol analysis into research protocols provides a non-invasive measure of HPA axis activity over time, which offers insight into animal health. Utilization of standard protocols across laboratories is essential to obtaining valid measurements and allowing for valuable future cross-species comparisons. © 2018 Wiley Periodicals, Inc.

Bulk hydrogen abundances in the lunar highlands: Measurements from orbital neutron data

NASA Astrophysics Data System (ADS)

Lawrence, David J.; Peplowski, Patrick N.; Plescia, Jeffrey B.; Greenhagen, Benjamin T.; Maurice, Sylvestre; Prettyman, Thomas H.

2015-07-01

The first map of bulk hydrogen concentrations in the lunar highlands region is reported. This map is derived using data from the Lunar Prospector Neutron Spectrometer (LP-NS). We resolve prior ambiguities in the interpretation of LP-NS data with respect to non-polar hydrogen concentrations by comparing the LP-NS data with maps of the 750 nm albedo reflectance, optical maturity, and the wavelength position of the thermal infrared Christiansen Feature. The best explanation for the variations of LP-NS epithermal neutron data in the lunar highlands is variable amounts of solar-wind-implanted hydrogen. The average hydrogen concentration across the lunar highlands and away from the lunar poles is 65 ppm. The highest hydrogen values range from 120 ppm to just over 150 ppm. These values are consistent with the range of hydrogen concentrations from soils and regolith breccias at the Apollo 16 highlands landing site. Based on a moderate-to-strong correlation of epithermal neutrons and orbit-based measures of surface maturity, the map of highlands hydrogen concentration represents a new global maturity index that can be used for studies of the lunar soil maturation process. We interpret these hydrogen concentrations to represent a bulk soil property related to the long-term impact of the space environment on the lunar surface. Consequently, the derived hydrogen concentrations are not likely related to the surficial enhancements (top tens to hundreds of microns) or local time variations of OH/H2O measured with spectral reflectance data.

High-performance gas sensors with temperature measurement

PubMed Central

Zhang, Yong; Li, Shengtao; Zhang, Jingyuan; Pan, Zhigang; Min, Daomin; Li, Xin; Song, Xiaoping; Liu, Junhua

2013-01-01

There are a number of gas ionization sensors using carbon nanotubes as cathode or anode. Unfortunately, their applications are greatly limited by their multi-valued sensitivity, one output value corresponding to several measured concentration values. Here we describe a triple-electrode structure featuring two electric fields with opposite directions, which enable us to overcome the multi-valued sensitivity problem at 1 atm in a wide range of gas concentrations. We used a carbon nanotube array as the first electrode, and the two electric fields between the upper and the lower interelectrode gaps were designed to extract positive ions generated in the upper gap, hence significantly reduced positive ion bombardment on the nanotube electrode, which allowed us to maintain a high electric field near the nanotube tips, leading to a single-valued sensitivity and a long nanotube life. We have demonstrated detection of various gases and simultaneously monitoring temperature, and a potential for applications. PMID:23405281

Nitrogen transport from tallgrass prairie watersheds

USGS Publications Warehouse

Dodds, W.K.; Blair, J.M.; Henebry, G.M.; Koelliker, J.K.; Ramundo, R.; Tate, C.M.

1996-01-01

Discharge and N content of surface water flowing from four Karat watersheds on Konza Prairie Research Natural Area, Kansas, managed with different burn frequencies, were monitored from 1986 to 1992. The goal was to establish the influence of natural processes (climate, fire, and bison grazing) on N transport and concentration in streams. Streams were characterized by variable flow, under conditions that included an extreme flood and a drought during which all channels were dry for over a year. The estimated groundwater/stream water discharge ratio varied between 0.15 to 6.41. Annual N transport by streams, averaged across all watersheds and years, was 0.16 kg N ha-1 yr-1. Annual N transport per unit area also increased as the watershed area increased and as precipitation increased. Total annual transport of N horn the prairie via streams ranged from 0.01 to 6.0% of the N input from precipitation. Nitrate and total N concentrations in surface water decreased (P < 0.001, r values ranged from 0.140.26) as length of time since last fire increased. Increased watershed area was correlated negatively (P < 0.0001) to stream water concentrations of NO3-N and total N (r values = -0.43 and -0.20, respectively). Low N concentration is typical of these streams, with NH4/+-N concentrations below 1.0 ??g L-1, NO3-N ranging from below 1.4 to 392 ??g L-1, and total N from 3.0 to 714 ??g L-1. These data provide an important baseline for evaluating N transport and stream water quality from unfertilized grasslands.

Evaluation of recombinant human thyroid-stimulating hormone to test thyroid function in dogs suspected of having hypothyroidism.

PubMed

Boretti, Felicitas S; Sieber-Ruckstuhl, Nadja S; Favrot, Claude; Lutz, Hans; Hofmann-Lehmann, Regina; Reusch, Claudia E

2006-12-01

To evaluate the use of recombinant human (rh) thyroid-stimulating hormone (TSH) in dogs with suspected hypothyroidism. 64 dogs with clinical signs of hypothyroidism. Dogs received rhTSH (75 microg/dog, IV) at a dose independent of their body weight. Blood samples were taken before and 6 hours after rhTSH administration for determination of total serum thyroxine (T(4)) concentration. Dogs were placed into 1 of 3 groups as follows: those with normal (ie, poststimulation values indicative of euthyroidism), unchanged (ie, poststimulation values indicative of hypothyroidism; no thyroid gland stimulation), or intermediate (ie, poststimulation values between unchanged and normal values) post-TSH T(4) concentrations. Serum canine TSH (cTSH) concentration was determined in prestimulation serum (ie, before TSH administration). 14, 35, and 15 dogs had unchanged, normal, and intermediate post-TSH T(4) concentrations, respectively. Basal T(4) and post-TSH T(4) concentrations were significantly different among groups. On the basis of basal serum T(4) and cTSH concentrations alone, 1 euthyroid (normal post-TSH T(4), low basal T(4), and high cTSH concentrations) and 1 hypothyroid dog (unchanged post-TSH T(4) concentration and low to with-in reference range T(4) and cTSH concentrations) would have been misinterpreted as hypothyroid and euthyroid, respectively. Nine of the 15 dogs with intermediate post-TSHT(4) concentrations had received medication known to affect thyroid function prior to the test, and 2 of them had severe nonthyroidal disease. The TSH-stimulation test with rhTSH is a valuable diagnostic tool to assess thyroid function in selected dogs in which a diagnosis of hypothyroidism cannot be based on basal T(4) and cTSH concentrations alone.

Mercury Contamination in Costa Rica

NASA Astrophysics Data System (ADS)

Varekamp, J. C.; Haynes, A.; Balcom, P. H.

2012-12-01

Recent measurements of Hg in air in the central valley of Costa Rica produced some remarkably high values (up to 700 ng Hg/m3;Castillo et al., 2011), raising concerns for public health. We made a broad assessment of Hg as an environmental contaminant in Costa Rica, and sampled and analyzed lake and wetland sediment and soils to derive atmospheric Hg deposition rates. We also measured Hg(0) in air in three locations, and sampled local fish that were analyzed for Hg. We set up a sampling program of Hg in hair of Costa Ricans, sampling hair from a broad crossection of the population, in combination with dietary and personal information. The lake sediments had Hg concentrations between 34 and 316 ppb Hg, with several lakes at common natural background concentrations (20-100 ppb Hg). Some lakes showed a Hg contamination component with concentrations well above simple background values. These sediments also were very rich in organic matter, and the high Hg concentrations may be a result of Hg focusing from the watersheds into the lake depositional environments. Deduced atmospheric deposition rates of Hg range from 0.16-0.25 ng Hg/cm2 per year, which is at the low end of the global range of measured wet atmospheric deposition rates. The observed Hg concentrations in sediment and soils thus can be characterized as natural background to mildly contaminated, but nothing that would indicate Hg inventories as expected from the reported high Hg air burdens. Some of our Hg(0) in air measurements were done at the same locations as those done earlier and yielded values between 0.6-4.2 ng Hg/m3; these values are similar to the low range measurements of Castillo et al. (their night time values), but we found no evidence in 2011 for their high daytime values. The range of a few ng Hg/m3 in air is compatible with global Hg dispersion modeling. Fish tissue of Trout and Tilapia gave a range of 68-112 ppb Hg (wet weight base), well below the 300 ppb Hg EPA alert level. Overall, these data do not point to a major local source of environmental Hg in Costa Rica, which would be most likely geothermal or volcanic in origin. We sampled hair from 53 people in San Jose, Heredia, and surrounding villages. The Hg(hair) contents ranged from 97-13,840 ppb Hg, with >50% of the subjects sampled above the USEPA alert level of 1000 ppb Hg. Three individuals had Hg> 8000 ppb Hg, which is a matter of concern. From the dietary information we calculated that 76% of the subjects sampled had an Hg intake above the USEPA recommended level of 0.1 microgram/kg bodyweight per day, largely from large marine fish such as tuna, swordfish, and shark. Many of the fish are imported and the local marine fish probably obtained their Hg burden outside the Costa Rica coastal region. In conclusion, there does not seem to be a direct large natural volcanic/geothermal Hg source in Costa Rica that may create public health concerns. However, the Costa Rican people studied by us have overall high Hg(hair) which seems to be related to their level of large marine fish consumption, which in several cases may be a matter of health concern.

Effect of pH and nitrite concentration on nitrite oxidation rate.

PubMed

Jiménez, E; Giménez, J B; Ruano, M V; Ferrer, J; Serralta, J

2011-10-01

The effect of pH and nitrite concentration on the activity of the nitrite oxidizing bacteria (NOB) in an activated sludge reactor has been determined by means of laboratory batch experiments based on respirometric techniques. The bacterial activity was measured at different pH and at different total nitrite concentrations (TNO₂). The experimental results showed that the nitrite oxidation rate (NOR) depends on the TNO₂ concentration independently of the free nitrous acid (FNA) concentration, so FNA cannot be considered as the real substrate for NOB. NOB were strongly affected by low pH values (no activity was detected at pH 6.5) but no inhibition was observed at high pH values (activity was nearly the same for the pH range 7.5-9.95). A kinetic expression for nitrite oxidation process including switch functions to model the effect of TNO₂ concentration and pH inhibition is proposed. Substrate half saturation constant and pH inhibition constants have been obtained. Copyright © 2011 Elsevier Ltd. All rights reserved.

Factors affecting ANKOM™ fiber analysis of forage and browse varying in condensed tannin concentration.

PubMed

Terrill, Thomas H; Wolfe, Richard M; Muir, James P

2010-12-01

Browse species containing condensed tannins (CTs) are an important source of nutrition for grazing/browsing livestock and wildlife in many parts of the world, but information on fiber concentration and CT-fiber interactions for these plants is lacking. Ten forage or browse species with a range of CT concentrations were oven dried and freeze dried and then analyzed for ash-corrected neutral detergent fiber (NDFom) and corrected acid detergent fiber (ADFom) using separate samples (ADFSEP) and sequential NDF-ADF analysis (ADFSEQ) with the ANKOM™ fiber analysis system. The ADFSEP and ADFSEQ residues were then analyzed for nitrogen (N) concentration. Oven drying increased (P < 0.05) fiber concentrations with some species, but not with others. For high-CT forage and browse species, ADFSEP concentrations were greater (P < 0.05) than NDFom values and approximately double the ADFSEQ values. Nitrogen concentration was greater (P < 0.05) in ADFSEP than ADFSEQ residues, likely due to precipitation with CTs. Sequential NDF-ADF analysis gave more realistic values and appeared to remove most of the fiber residue contaminants in CT forage samples. Freeze drying samples with sequential NDF-ADF analysis is recommended in the ANKOM™ fiber analysis system with CT-containing forage and browse species. Copyright © 2010 Society of Chemical Industry.

[Gas Concentration Measurement Based on the Integral Value of Absorptance Spectrum].

PubMed

Liu, Hui-jun; Tao, Shao-hua; Yang, Bing-chu; Deng, Hong-gui

2015-12-01

The absorptance spectrum of a gas is the basis for the qualitative and quantitative analysis of the gas by the law of the Lambert-Beer. The integral value of the absorptance spectrum is an important parameter to describe the characteristics of the gas absorption. Based on the measured absorptance spectrum of a gas, we collected the required data from the database of HIT-RAN, and chose one of the spectral lines and calculated the integral value of the absorptance spectrum in the frequency domain, and then substituted the integral value into Lambert-Beer's law to obtain the concentration of the detected gas. By calculating the integral value of the absorptance spectrum we can avoid the more complicated calculation of the spectral line function and a series of standard gases for calibration, so the gas concentration measurement will be simpler and faster. We studied the changing trends of the integral values of the absorptance spectrums versus temperature. Since temperature variation would cause the corresponding variation in pressure, we studied the changing trends of the integral values of the absorptance spectrums versus both the pressure not changed with temperature and changed with the temperature variation. Based on the two cases, we found that the integral values of the absorptance spectrums both would firstly increase, then decrease, and finally stabilize with temperature increasing, but the ranges of specific changing trend were different in the two cases. In the experiments, we found that the relative errors of the integrated values of the absorptance spectrum were much higher than 1% and still increased with temperature when we only considered the change of temperature and completely ignored the pressure affected by the temperature variation, and the relative errors of the integrated values of the absorptance spectrum were almost constant at about only 1% when we considered that the pressure were affected by the temperature variation. As the integral value of the absorptance spectrum varied with temperature and the calculating error for the integral value fluctuates with ranges of temperature, in the gas measurement when we usd integral values of the absoptance spectrum, we should select a suitable temperature variation and obtain a more accurate measurement result.

High levels of migratable lead and cadmium on decorated drinking glassware.

PubMed

Turner, Andrew

2018-03-01

Externally decorated glassware used for the consumption of beverages, purchased new or sourced second-hand, and including tumblers, beer glasses, shot glasses, wine glasses and jars, has been analysed for Pb and Cd by portable x-ray fluorescence (XRF) spectrometry. Out of 197 analyses performed on distinctly different colours and regions of enamelling on 72 products, Pb was detected in 139 cases and among all colours tested, with concentrations ranging from about 40 to 400,000μgg -1 (median=63,000μgg -1 ); Cd was detected in 134 cases and among all colours apart from gold leaf, with concentrations ranging from about 300 to 70,000μgg -1 (median=8460μgg -1 ). The frequent occurrence of these metals is attributed to their use in both the oxidic fluxes and coloured pigments of decorative enamels employed by the glass industry. A standard test involving extraction of the external surface to within 20mm of the rim (lip area) by 4% acetic acid and subsequent analysis by ICP was applied to selected positive samples (n=14). Lead concentrations normalised to internal volume exceeded limit values of 0.5mgL -1 in all but one case, with concentrations over 100mgL -1 returned by three products. Cadmium concentrations exceeded limit values of 4mgL -1 in five cases, with a maximum concentration of about 40mgL -1 . Repeating the experiment on five positive samples using a carbonated drink (Coca Cola Classic) resulted in lower extractable concentrations but non-compliance for Pb in all cases. The presence of high concentrations of total and extractable Pb and Cd in the decorated lip areas of a wide range of products manufactured in both China and Europe is cause for concern from a health and safety perspective. Copyright © 2017 Elsevier B.V. All rights reserved.

Regional soil-gas helium distribution of the Ely and Delta 1° x 2° quadrangles, Basin and Range Province

USGS Publications Warehouse

Reimer, G.M.; Bowles, C.G.

1990-01-01

A reconnaissance soil-gas helium survey was made in the Ely, Nevada and Delta, Utah 1° × 2° quadrangles in the Basin and Range Province. Helium concentrations in 510 samples ranged from −147 to 441 ppb He with respect to ambient air. The median helium value for the study area was 36 ppb. Concentrations of more than 100 ppb He and less than −20 ppb He occur more commonly in the Ely quadrangle and are especially numerous in the western one-half of this quadrangle. Interpretation of the data reveals that the helium concentrations reflect the rock type, particularly the silicic volcanic occurrences, and the geological structure of the area created by crustal extension. The regional soil-gas helium distribution is important information to consider when interpreting anomalies from detailed surveys.

Aqueous solubilities, vapor pressures, and 1-octanol-water partition coefficients for C9-C14 linear alkylbenzenes

USGS Publications Warehouse

Sherblom, P.M.; Gschwend, P.M.; Eganhouse, R.P.

1992-01-01

Measurements and estimates of aqueous solubilities, 1-octanol-water partition coefficients (Kow), and vapor pressures were made for 29 linear alkylbenzenes having alkyl chain lengths of 9-14 carbons. The ranges of values observed were vapor pressures from 0.002 to 0.418 Pa, log Kow, from 6.83 to 9.95, and aqueous solubilities from 4 to 38 nmol??L-1. Measured values exhibited a relationship to both the alkyl chain length and the position of phenyl substitution on the alkyl chain. Measurement of the aqueous concentrations resulting from equilibration of a mixture of alkylbenzenes yielded higher than expected values, indicating cosolute or other interactive effects caused enhanced aqueous concentrations of these compounds. ?? 1992 American Chemical Society.

Influence of different natural zeolite concentrations on the anaerobic digestion of piggery waste.

PubMed

Milán, Z; Sánchez, E; Weiland, P; Borja, R; Martín, A; Ilangovan, K

2001-10-01

The effect of different natural zeolite concentrations on the anaerobic digestion of piggery waste was studied. Natural zeolite doses in the range 0.2-10 g/l of wastewater were used in batch experiments, which were carried out at temperatures between 27 degrees C and 30 degrees C. Total chemical oxygen demand (COD), total and volatile solids, ammonia and organic nitrogen, pH, total volatile fatty acids (TVFA), alkalinity (Alk) and accumulative methane production were determined during 30 days of digestion. The anaerobic digestion process was favored by the addition of natural zeolite at doses between 2 and 4 g/l and increasingly inhibited at doses beyond 6 g/l. A first-order kinetic model of COD removal was used to determine the apparent kinetic constants of the process. The kinetic constant values increased with the zeolite amount up to a concentration of 4 g/l. The values of the maximum accumulative methane production (Gm) increased until zeolite concentrations of 2-4 g/l. The addition of zeolite reduced the values of the TVFA/ Alk ratio while increasing the pH values, and these facts could contribute to the process failure at zeolite doses of 10 g/l.

[Carotenoids and vitamin A in fish].

PubMed

Elmadfa, I; Majchrzak, D

1998-06-01

Seven commercial salmon and six trout samples were investigated. Retinol and the carotenoids astaxanthin and canthaxanthin important for pigmentation of the muscle were determined by RP-HPLC. Vitamin A concentrations of raw salmon samples were 16-19 micrograms/100 g, of smoked salmon samples 9-19 micrograms/ 100 g; retinol values of salmon trout (raw) and trout (raw) reached 14-16 micrograms/100 g and 7-9 micrograms/100 g. Concentrations of astaxanthin the important carotenoid of pigmentation, ranged in samples of salmon from 310-465 micrograms/100 g. Samples of salmon trout showed astaxanthin values between 90 and 536 micrograms/100 g, trout samples only 67-85 micrograms/100 g. Concentrations of canthaxanthin were different in the examined samples and were not detectable in all samples. Highest values of canthaxanthin were found in salmon trout samples (113-226 micrograms/100 g), Irish smoked salmon and stremel-salmon (145-169 micrograms/100 g). Raw samples of salmon and of trout showed only low concentrations of canthaxanthin. Astaxanthin and canthaxanthin together reached values of 419-524 micrograms/100 g for salmon, 316-701 micrograms/100 g for salmon trout, and 72-91 micrograms/100 g for trout samples.

Crystal Structure Characterization of Thin Layer Zinc Oxide

NASA Astrophysics Data System (ADS)

Doyan, Aris; Susilawati; Azizatul Fitri, Siti; Ahzan, Sukainil

2017-05-01

In this research the characterization of the crystal structure of a thin layer of ZnO (zinc oxide) were synthesized by sol - gel method and spin coating deposited on a glass substrate. The samples were divided into three sol concentrations of 0.1, 0.3, 0.5 Molar and two deposition temperature is 350 °C, and 550 °C. UV-Vis. spectrophotometer results showed that in the spectrum of visible light (wavelength range 300-800 nm) has a transmittance value of which increases with increasing concentration and temperature deposition of zinc oxide, otherwise the value of the absorption and the band gap energy decreases with the addition of concentration and deposition temperature. The transmittances value of the highest and lowest absorption was 93.5% and 0.03 is at a concentration of 0.1 M and zinc oxide deposition temperature of 550 °C, with a value of band gap energy of 2.98 eV. The XRD results showed that the zinc oxide crystal orientation in the field of 013 with a crystal grain size 14.4472 nm. SEM results showed the surface morphology of zinc oxide such as rod-like.

An assessment of the natural radioactivity distribution and radiation hazard in soil samples from Qatar using high-resolution gamma-ray spectrometry

NASA Astrophysics Data System (ADS)

Al-Sulaiti, Huda; Al Mugren, K. S.; Bradley, D. A.; Regan, P. H.; Santawamaitre, T.; Malain, D.; Habib, A.; Nasir, Tabassum; Alkhomashi, N.; Al-Dahan, N.; Al-Dosari, M.; Bukhari, S.

2017-11-01

We establish baseline measurements for radioactivity concentration in the soil samples collected from the Qatarian peninsula. The work focused on the naturally occurring and technically enhanced levels of radiation associated with 235,8U and 232Th natural decay chains and the long-lived naturally occurring radionuclide 40K in 129 soil samples collected across the landscape of the State of Qatar. Three radiological distribution maps showing the activity concentrations of 226Ra, 232Th and 40K were constructed. Two soil samples were found to be elevated to the favour of 226Ra concentration and significantly above the average and global values. Notably, these samples were collected from an area within an oil field (NW Dukhan). The mean values of activity concentrations of 226Ra, 232Th and 40K for the full cohort of samples were found to be 17.2±1.6, 6.38±0.26 and 169±5 Bq/kg, respectively. These values lie within the expected range relative to the world average values in soil samples of 30, 35 and 400 Bq/kg, respectively.

Effects of Simulated Land-Use Changes on Water Quality of Lake Maumelle, Arkansas

USGS Publications Warehouse

Hart, Rheannon M.; Westerman, Drew A.; Petersen, James C.; Green, W. Reed; De Lanois, Jeanne L.

2011-01-01

Lake Maumelle is one of two principal drinking-water supplies for the Little Rock and North Little Rock metropolitan areas. Lake Maumelle and the Maumelle River (its primary tributary) are more pristine than most other reservoirs and streams in the region. However, as the Lake Maumelle watershed becomes increasingly more urbanized and timber harvesting becomes more frequent, concerns about the sustainability of the quality of the water supply also have increased. Two models were developed to partially address these concerns. A Hydrological Simulation Program-FORTRAN model was developed using input data collected from October 2004 through 2008. A CE-QUAL-W2 model was developed to simulate reservoir hydrodynamics and selected water quality using the simulated output from the Hydrological Simulation Program-FORTRAN model from January 2005 through 2008. The Hydrological Simulation Program-FORTRAN watershed model was calibrated to five streamflow-gaging stations, and in general, these stations characterize a range of subwatershed areas with varying land-use types. Continuous streamflow data, discrete sediment concentration data, and other discrete water-quality data were used to calibrate the Lake Maumelle Hydrological Simulation Program-FORTRAN model. The CE-QUAL-W2 reservoir model was calibrated to water-quality data and reservoir pool altitude collected during January 2005 through December 2008 at three lake stations. In general, the overall simulation for the Hydrological Simulation Program-FORTRAN and CE-UAL-W2 models matched reasonably well to the measured data. In general, simulated and measured suspended-sediment concentrations during periods of base flow (streamflows not substantially influenced by runoff) agree reasonably well for Williams Junction (with differences-simulated minus measured value-generally ranging from -14 to 19 mg/L, and percent difference-relative to the measured value-ranging from -87 to 642 percent) and Wye (differences generally ranging from -2 to 14 mg/L, -62 to 251 percent); however, the Hydrological Simulation Program-FORTRAN model generally does not match the suspended-sediment concentrations for all stations during periods of stormflow (streamflow substantially influenced by runoff). Generally, this is also the case for fecal coliform bacteria numbers and total organic carbon and nutrient concentrations. In general, water temperature and dissolved-oxygen concentration simulations followed measured seasonal trends for all stations with the largest differences occurring during periods of lowest water temperatures (for temperature) or during the periods of lowest measured dissolved-oxygen concentrations (for dissolved oxygen). For the CE-QUAL-W2 model, simulated vertical distributions of temperatures and dissolved-oxygen concentrations agreed with measured distributions even for complex temperature profiles. Considering the oligotrophic-mesotrophic (low to intermediate primary productivity and associated low nutrient concentrations) condition of Lake Maumelle, simulated algae, phosphorus, and ammonia concentrations compared well with generally low measured values.

Characterization and data-gap analysis of surface-water quality data in the Piceance study area, western Colorado, 1959–2009

USGS Publications Warehouse

Thomas, Judith C.; Moore, Jennifer L.; Schaffrath, Keelin R.; Dupree, Jean A.; Williams, Cory A.; Leib, Kenneth J.

2013-01-01

The U.S. Geological Survey, in cooperation with Federal, State, county, and industry partners, developed a Web-accessible common data repository to provide access to historical and current (as of August 2009) water-quality information (available on the Internet at http://rmgsc.cr.usgs.gov/cwqdr/Piceance/index.shtml). Surface-water-quality data from public and private sources were compiled for the period 1931 to 2009 and loaded into the common data repository for the Piceance Basin. A subset of surface-water-quality data for 1959 to 2009 from the repository were compiled, reviewed, and checked for quality assurance for this report. This report contains data summaries, comparisons to water-quality standards, trend analyses, a generalized spatial analysis, and a data-gap analysis for select water-quality properties and constituents. Summary statistics and a comparison to standards were provided for 347 sites for 33 constituents including field properties, nutrients, major ions, trace elements, suspended sediment, Escherichia coli, and BTEX (benzene, toluene, ethylbenzene, and xylene). When sufficient data were available, trends over time were analyzed and loads were calculated for those sites where there were also continuous streamflow data. The majority of sites had information on field properties. Water temperature data was available for 316 sites where data were collected between 1959 and 2009. The only trend that was detected in temperature was an upward trend at the Gunnison River near Grand Junction, Colorado. There were 326 values out of a total of 32,006 values in the study area that exceeded the aquatic-life standard for daily maximum water temperature. For the entire study area, 196 sites had dissolved-oxygen data collected between 1970 and 2009, and median dissolved-oxygen concentrations ranged from 6.8 to11.2 milligrams per liter (mg/L). There were 185 concentrations that exceeded the dissolved oxygen aquatic-life standard out of a total of 11,248 values. The pH data were available for 276 sites, and median pH values ranged from 7.5 to 9.0. There were 241 values that exceeded the high pH standard and 13 values that were less than the low pH standard of the 16,790 values in the study area. Nutrients within the study area were not well represented in each basin and were often not being sampled currently. For the entire study area, 62 sites had nitrate data collected between 1958 and 2009, and median nitrate concentrations ranged from less than detection to 3.72 mg/L as nitrogen. The maximum contaminant level for domestic water supply for nitrate is 10 mg/L and was exceeded once in 3,736 samples. Total phosphorus was collected at 113 sites between 1974 and 2009, and median total phosphorus concentrations ranged from less than detection to 5.04 mg/L. The U.S. Environmental Protection Agency recommendation for phosphorus is less than 0.1 mg/L, and 1,469 of 4,842 samples exceeded this recommended standard. An upward trend in both nitrate and total phosphorus was detected in the White River above Coal Creek near Meeker, Colo. Standards for major ions exist only for chloride and sulfate. For the entire study area, 118 sites had both chloride and sulfate concentration data collected between 1958 and 2009. Median chloride concentrations ranged from 0.085 mg/L to 280 mg/L. Median sulfate concentrations ranged from 4.57 mg/L to 15,000 mg/L. Both chloride and sulfate domestic water-supply standards are 250 mg/L. There were 120 chloride concentrations and 1,111 sulfate concentration samples that exceeded these standards. A downward trend in dissolved solids was detected at the Colorado River near the Colorado-Utah state border and could be a result of salinity control work near Grand Junction, Colo. Trace elements were relatively well represented both temporally and spatially in the study area though the number of trace element samples per site was not typically enough to compute trends or loads except for selenium. There were 127 sites that had dissolved iron concentration data collected between 1961 and 2009, and median iron concentrations ranged from less than detection to 1,100 micrograms per liter (µg/L). The 30-day drinking-water standard for iron is 300 µg/L, and 203 samples exceeded the standard. Selenium was the best represented trace element with selenium concentration data collected at 197 sites between 1973 and 2009, and median selenium concentrations range from less than detection to 181 µg/L. The chronic standard of 4.6 µg/L for selenium concentrations was exceeded in 899 samples, and the acute aquatic-life standard of 18.4 µg/ for selenium was exceeded in 629 samples. High concentrations of selenium are of concern in the Lower Gunnison River Basin because of the combination of geologic formations and land use. There were significant downward trends in selenium at both main-stem sites on the Gunnison River at Delta, Colo., and the Gunnison River near Grand Junction, Colo. High selenium concentrations correlate with high salinity concentrations; thus, when salinity control efforts are conducted in selenium-rich areas in the Lower Gunnison River Basin, both salinity and selenium have the potential to decrease. Spatial, temporal, and analytical data gaps were identified in the study area. The spatial coverage of sampling sites could be expanded in the White River Basin by adding more tributary sites. No water-quality data exist for tributary streams in the area north of Rangely, Colo., where extensive energy development has occurred in a complex geologic setting. Douglas Creek has a drainage area of 425 square miles and has limited historic water-quality and water-quantity data. Limited data were available for field properties, major ions, nutrients, and trace elements on the main stem of the Colorado River between Glenwood Springs and Cameo, Colo. Nutrient data were minimally collected upstream from Colorado River at the Colorado-Utah state border and on the Gunnison River (major tributary in the reach). Approximately 30 percent of the samples for total phosphorus in the Lower Gunnison River Basin exceeded the recommended standard, yet there were insufficient data to do trends analysis in the Lower Gunnison River Basin except at the Gunnison near Grand Junction site. There is limited trace element data except for selenium in the Lower Gunnison River Basin. Additional sampling is necessary to understand the occurrence, concentrations, and loads of these constituents.

Two Degrees of Separation: Abrupt Climate Change and the Adverse Impact to US National Security

DTIC Science & Technology

2009-04-01

concentrations of CO2 , CH4 and N2O have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values...determined from ice cores spanning many thousands of years. The atmospheric concentrations of CO2 and CH4 in 2005 exceed by far the natural range over the...last 650,000 years. Global increases in CO2 concentrations are due primarily to fossil fuel use, with land-use change providing another significant

Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

DOEpatents

Wanlass, M.W.

1994-12-27

A single-junction solar cell is described having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of ''pinning'' the optimum band gap for a wide range of operating conditions at a value of 1.14[+-]0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap. 7 figures.

Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

DOEpatents

Wanlass, Mark W.

1994-01-01

A single-junction solar cell having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of "pinning" the optimum band gap for a wide range of operating conditions at a value of 1.14.+-.0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap.

Determination of natural radioactivity by gross alpha and beta measurements in ground water samples.

PubMed

Turhan, S; Ozçitak, E; Taşkin, H; Varinlioğlu, A

2013-06-01

In this study, the activity concentrations of the gross α and β in ground water samples collected from the different drilled wells in Nevşehir province were measured to assess annual effective dose due to the ingestion of the water samples. Nevşehir province is one of the major cities of Cappadocia Region which is a popular tourist destination as it has many areas with unique geological, historic, and cultural features. Sampling and measurements were carried out in the autumn of 2011 and the spring of 2012. The values of the activity concentrations of the gross α and β measured in the water samples ranged from 80 to 380 mBq L(-1) with a mean of 192 mBq L(-1) and 120-3470 mBq L(-1) with a mean of 579 mBq L(-1) respectively. All values of the gross α were lower than the limit value of 500 mBq L(-1) while two ground water samples were found to have gross β activity concentrations of greater than 1000 mBq L(-1). Therefore two water samples were the subject of further radioisotope-specific analysis. The obtained result indicated that the elevated activity concentrations of the gross β in these water samples are dominated by (40)K activity. Annual effective doses ranged from 0.04 to 0.20 mSv y(-1). Copyright © 2013 Elsevier Ltd. All rights reserved.

Chemical and biological assessment of sediments and water of Khalid Khor, Sharjah, United Arab Emirates.

PubMed

Samara, Fatin; Elsayed, Yehya; Soghomonian, Balik; Knuteson, Sandra L

2016-10-15

Water and sediments were collected on March 2013 and April 2014 from Khalid Khor creek area in United Arab Emirates to assess their quality parameters. The pH and alkalinity of the water samples were measured and their values were similar to those of shallow saltwater ecosystems. In addition, elemental analyses and organic compounds were done using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) and Gas Chromatography-Mass Spectroscopy (GC-MS), respectively. The concentration of heavy and trace metals in the water samples were within the acceptable limits except for lead which showed high values, while the concentrations of metals in the sediment samples were relatively high and ranged from 6517 to 13,768mg/kg. GC-MS analysis showed the presence of polyaromatic heterocyclic (PAHs) compounds in sediments near the shipping area and in amounts classified as highly carcinogenic; however, no polychlorinated biphenyls (PCB) were identified. Moreover, fecal bacterial contamination in water was detected in concentrations that range between 300 and 10,140 organisms/100mL. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development and validation of simple spectrophotometric and chemometric methods for simultaneous determination of empagliflozin and metformin: Applied to recently approved pharmaceutical formulation

NASA Astrophysics Data System (ADS)

Ayoub, Bassam M.

2016-11-01

New univariate spectrophotometric method and multivariate chemometric approach were developed and compared for simultaneous determination of empagliflozin and metformin manipulating their zero order absorption spectra with application on their pharmaceutical preparation. Sample enrichment technique was used to increase concentration of empagliflozin after extraction from tablets to allow its simultaneous determination with metformin without prior separation. Validation parameters according to ICH guidelines were satisfactory over the concentration range of 2-12 μg mL- 1 for both drugs using simultaneous equation with LOD values equal to 0.20 μg mL- 1 and 0.19 μg mL- 1, LOQ values equal to 0.59 μg mL- 1 and 0.58 μg mL- 1 for empagliflozin and metformin, respectively. While the optimum results for the chemometric approach using partial least squares method (PLS-2) were obtained using concentration range of 2-10 μg mL- 1. The optimized validated methods are suitable for quality control laboratories enable fast and economic determination of the recently approved pharmaceutical combination Synjardy® tablets.

Estimation of mercury background values in sediment and biota of the Bijagós archipelago, Guinea-Bissau.

PubMed

Coelho, J P; Monteiro, R J R; Catry, T; Lourenço, P M; Catry, P; Regalla, A; Catry, I; Figueira, P; Pereira, E; Vale, C; P Granadeiro, José

2016-10-15

This work evaluates the mercury (Hg) contamination status (sediments and biota) of the Bijagós archipelago, off the coast of Guinea-Bissau. Sediments exhibited very low concentrations (<1-12ngg(-1)), pointing to negligible sources of anthropogenic Hg in the region. Nevertheless, Hg is well correlated to the fine fraction, aluminium, and loss on ignition, indicating the effect of grain size and organic matter content on the presence of Hg in sediments. Mercury in the bivalves Tagelus adansoni and Senilia senilis did not vary considerably among sites, ranging within narrow intervals (0.09-0.12 and 0.12-0.14μgg(-1) (dry weight), respectively). Divergent substrate preferences/feeding tactics may justify slight differences between species. The value 11ngg(-1) is proposed as the sediment background concentration for this West-African coastal region, and concentrations within the interval 8-10ngg(-1) (wet weight) may be considered as reference range for S. senilis and T. adansoni in future monitoring studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ikaite crystal distribution in winter sea ice and implications for CO2 system dynamics

NASA Astrophysics Data System (ADS)

Rysgaard, S.; Søgaard, D. H.; Cooper, M.; Pućko, M.; Lennert, K.; Papakyriakou, T. N.; Wang, F.; Geilfus, N. X.; Glud, R. N.; Ehn, J.; McGinnis, D. F.; Attard, K.; Sievers, J.; Deming, J. W.; Barber, D.

2013-04-01

The precipitation of ikaite (CaCO3 ⋅ 6H2O) in polar sea ice is critical to the efficiency of the sea ice-driven carbon pump and potentially important to the global carbon cycle, yet the spatial and temporal occurrence of ikaite within the ice is poorly known. We report unique observations of ikaite in unmelted ice and vertical profiles of ikaite abundance and concentration in sea ice for the crucial season of winter. Ice was examined from two locations: a 1 m thick land-fast ice site and a 0.3 m thick polynya site, both in the Young Sound area (74° N, 20° W) of NE Greenland. Ikaite crystals, ranging in size from a few μm to 700 μm, were observed to concentrate in the interstices between the ice platelets in both granular and columnar sea ice. In vertical sea ice profiles from both locations, ikaite concentration determined from image analysis, decreased with depth from surface-ice values of 700-900 μmol kg-1 ice (~25 × 106 crystals kg-1) to values of 100-200 μmol kg-1 ice (1-7 × 106 crystals kg-1) near the sea ice-water interface, all of which are much higher (4-10 times) than those reported in the few previous studies. Direct measurements of total alkalinity (TA) in surface layers fell within the same range as ikaite concentration, whereas TA concentrations in the lower half of the sea ice were twice as high. This depth-related discrepancy suggests interior ice processes where ikaite crystals form in surface sea ice layers and partly dissolve in layers below. Melting of sea ice and dissolution of observed concentrations of ikaite would result in meltwater with a pCO2 of <15 μatm. This value is far below atmospheric values of 390 μatm and surface water concentrations of 315 μatm. Hence, the meltwater increases the potential for seawater uptake of CO2.

Mercury and selenium in fishes from the Tapajós River in the Brazilian Amazon: An evaluation of human exposure.

PubMed

Lino, A S; Kasper, D; Guida, Y S; Thomaz, J R; Malm, O

2018-07-01

This work aimed to evaluate associated risks of fish consumption to human health, concerning mercury (Hg) and selenium (Se) concentrations in fish species largely consumed in the Tapajós River basin in the Brazilian Amazon. Total mercury (THg), methylmercury (MeHg) and Se concentrations were measured in 129 fish specimens from four sites of the Tapajós River basin. Estimated daily intake (EDI) of Hg and Se were reported regarding fish consumption. EDI were compared with the reference value of provisional tolerable daily intake proposed by the World Health Organization (WHO). Se:Hg ratios and selenium health benefit values (Se HBVs) seem to offer a more comprehensive fish safety model. THg concentrations in fishes ranged from 0.03 to 1.51 μg g -1 of wet weight (w.w.) and MeHg concentrations ranged from 0.02 to 1.44 μg g -1 (w.w.). 80% of the samples were below the value of Hg recommended by the WHO for human consumption (0.5 μg g -1 w.w.). However, Hg EDI exceeded the dose suggested by the United States Environmental Protection Agency (0.1 μg kg -1  day -1 ), due to the large level of fish consumption in that area. Se concentrations in fishes ranged from 0.02 to 0.44 μg g -1 w.w. An inverse pattern was observed between Hg and Se concentrations in the trophic chain (highest levels of Se in the lowest trophic levels). The molar ratio Se:Hg and Se HBVs were higher in iliophagous and herbivorous fishes, which is noteworthy to reduce toxic effects of Hg contamination. For planktivores, the content of Se and Hg was almost equimolar. Carnivorous fishes - with the exception of Hemisorubim platyrhynchos and Pseudoplatystoma fasciatum -, showed Se:Hg ratios <1. Thus, they do not act as a favorable source of Se in the diet. Therefore, reduced intake of carnivorous fishes with preferential consumption of iliophages, herbivores and, to some extent, even planktivores should be promoted as part of a healthier diet. Copyright © 2018 Elsevier GmbH. All rights reserved.

Assessment of natural radioactivity levels in rocks and their relationships with the geological structure of Johor state, Malaysia.

PubMed

Alnour, I A; Wagiran, H; Ibrahim, N; Hamzah, S; Elias, M S; Laili, Z; Omar, M

2014-01-01

The distribution of natural radionuclides ((238)U, (232)Th and (40)K) and their radiological hazard effect in rocks collected from the state of Johor, Malaysia were determined by gamma spectroscopy using a high-purity germanium detector. The highest values of (238)U, (232)Th and (40)K activity concentrations (67±6, 85±7 and 722±18 Bg kg(-1), respectively) were observed in the granite rock. The lowest concentrations of (238)U and (232)Th (2±0.1 Bq kg(-1) for (238)U and 2±0.1 Bq kg(-1) for (232)Th) were observed in gabbro rock. The lowest concentration of (40)K (45±2 Bq kg(-1)) was detected in sandstone. The radium equivalent activity concentrations for all rock samples investigated were lower than the internationally accepted value of 370 Bq kg(-1). The highest value of radium equivalent in the present study (239±17 Bq kg(-1)) was recorded in the area of granite belonging to an acid intrusive rock geological structure. The absorbed dose rate was found to range from 4 to 112 nGy h(-1). The effective dose ranged from 5 to 138 μSv h(-1). The internal and external hazard index values were given in results lower than unity. The purpose of this study is to provide information related to radioactivity background levels and the effects of radiation on residents in the study area under investigation. Moreover, the relationships between the radioactivity levels in the rocks within the geological structure of the studied area are discussed.

Carbon and nitrogen systematics in nitrogen-rich, ultradeep diamonds from Sao Luiz, Brazil

NASA Astrophysics Data System (ADS)

Navon, Oded; Stachel, Thomas; Stern, Richard A.; Harris, Jeffrey W.

2018-05-01

Three diamonds from Sao Luiz, Brazil carrying nano- and micro-inclusions of molecular δ-N2 that exsolved at the base of the transition zone were studied for their C and N isotopic composition and the concentration of N utilizing SIMS. The diamonds are individually uniform in their C isotopic composition and most spot analyses yield δ13C values of -3.2 ± 0.1‰ (ON-SLZ-390) and - 4.7 ± 0.1‰ (ON-SLZ-391 and 392). Only a few analyses deviate from these tight ranges and all fall within the main mantle range of -5 ± 3‰. Most of the N isotope analyses also have typical mantle δ15N values (-6.6 ± 0.4‰, -3.6 ± 0.5‰ and - 4.1 ± 0.6‰ for ON-SLZ-390, 391 and 392, respectively) and are associated with high N concentrations of 800-1250 atomic ppm. However, some N isotopic ratios, associated with low N concentrations (<400 ppm) and narrow zones with bright luminescence are distinctly above the average, reaching positive δ15N values. These sharp fluctuations cannot be attributed to fractionation. They may reflect arrival of new small pulses of melt or fluid that evolved under different conditions. Alternatively, they may result from fractionation between different growth directions, so that distinct δ15N values and N concentrations may form during diamond growth from a single melt/fluid. Other more continuous variations, in the core of ON-SLZ-390 or the rim of ON-SLZ-392 may be the result of Rayleigh fractionation or mixing.

Ultrasound-assisted combined with nano-sized molecularly imprinted polymer for selective extraction and pre-concentration of amitriptyline in human plasma with gas chromatography-flame detection.

PubMed

Khanahmadzadeh, Salah; Tarigh, Ahmad

2014-12-01

A new process was developed for the selective extraction and pre-concentration of amitriptyline (AT) from human plasma using nano-sized molecularly imprinted polymer (MIP) with ultrasound-assisted extraction (UAE). The nano-sized AT imprinted polymer particles were synthesized using suspension polymerization in silicon oil and characterized by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscope (SEM) methods. With the application of optimized values, linearity values in the ranges of 20-200μgmL(-1) and 35-200μgmL(-1) were obtained for AT with the correlation of determination values (r(2)) 0.998 and 0.995 in water and plasma, respectively. The limits of detections (S/N=3) for AT were found to be 0.7 and 1.2μgmL(-1) in water and plasma, respectively. The enrichment factors of AT in water and plasma were 52 and 40, respectively. The inter-day precisions (%) were in the range of 5.8-9.2%. Relative recovery rates ranged from 82.4% to 92.3%. The method was successfully applied to determine AT in the human plasma samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Stable carbon isotopes of HCO3- in oil-field waters-implications for the origin of CO2

USGS Publications Warehouse

Carothers, W.W.; Kharaka, Y.K.

1980-01-01

The ??13C values of dissolved HCO3- in 75 water samples from 15 oil and gas fields (San Joaquin Valley, Calif., and the Houston-Galveston and Corpus Christi areas of Texas) were determined to study the sources of CO2 of the dissolved species and carbonate cements that modify the porosity and permeability of many petroleum reservoir rocks. The reservoir rocks are sandstones which range in age from Eocene through Miocene. The ??13C values of total HCO3- indicate that the carbon in the dissolved carbonate species and carbonate cements is mainly of organic origin. The range of ??13C values for the HCO3- of these waters is -20-28 per mil relative to PDB. This wide range of ??13C values is explained by three mechanisms. Microbiological degradation of organic matter appears to be the dominant process controlling the extremely low and high ??13C values of HCO3- in the shallow production zones where the subsurface temperatures are less than 80??C. The extremely low ??13C values (< -10 per mil) are obtained in waters where concentrations of SO42- are more than 25 mg/l and probably result from the degradation of organic acid anions by sulfate-reducing bacteria (SO42- + CH3COO- ??? 2HCO3- + HS-). The high ??13C values probably result from the degradation of these anions by methanogenic bacteria (CH3COO- + H2O ai HCO3- + CH4). Thermal decarboxylation of short-chain aliphatic acid anions (principally acetate) to produce CO2 and CH4 is probably the major source of CO2 for production zones with subsurface temperatures greater than 80??C. The ??13C values of HCO3- for waters from zones with temperatures greater than 100??C result from isotopic equilibration between CO2 and CH4. At these high temperatures, ??13C values of HCO3- decrease with increasing temperatures and decreasing concentrations of these acid anions. ?? 1980.

One-carbon (bio ?) Geochemistry in Subsurface Waters of the Serpentinizing Coast Range Ophiolite

NASA Technical Reports Server (NTRS)

Hoehler, Tori M.; Mccollom, Tom; Schrenk, Matt; Cardace, Dawn

2011-01-01

Serpentinization - the aqueous alteration of ultramafic rocks - typically imparts a highly reducing and alkaline character to the reacting fluids. In turn, these can influence the speciation and potential for metabolism of one-carbon compounds in the system. We examined the aqueous geochemistry and assessed the biological potential of one-carbon compounds in the subsurface of the McLaughlin Natural Reserve (Coast Range Ophiolite, California, USA). Fluids from wells sunk at depths of 25-90 meters have pH values ranging from 9.7 to 11.5 and dissolved inorganic carbon (DIC concentrations) generally below 60 micromolar. Methane is present at concentrations up to 1.3 millimolar (approximately one-atmosphere saturation), and hydrogen concentrations are below 15 nanomolar, suggesting active consumption of H2 and production of CH4. However, methane production from CO2 is thermodynamically unfavorable under these conditions. Additionally, the speciation of DIC predominantly into carbonate at these high pH values creates a problem of carbon availability for any organisms that require CO2 (or bicarbonate) for catabolism or anabolism. A potential alternative is carbon monoxide, which is present in these waters at concentrations 2000-fold higher than equilibrium with atmospheric CO. CO is utilized in a variety of metabolisms, including methanogenesis, and bioavailability is not adversely affected by pH-dependent speciation (as for DIC). Methanogenesis from CO under in situ conditions is thermodynamically favorable and would satisfy biological energy requirements with respect to both Gibbs Energy yield and power.

Hematologic and serum biochemical reference intervals for Florida panthers.

USGS Publications Warehouse

Dunbar, M.R.; Nol, P.; Linda, S.B.

1997-01-01

Ninety-four blood samples were collected from 48 (29 males and 19 females) free-ranging Florida panthers (Felis concolor coryi) captured in southern Florida (USA) from 1983 to 1994 for routine hematological and serum biochemical analysis. Florida panthers in the northern portion of their range had significantly higher red blood cell (mean +/- SD = 7.923 x 10(6) +/- 0.854 x 10(6)/microliter), hemoglobin (12.53 +/- 1.66 g/dl), and packed cell volume (36.97 +/- 4.27%) values compared to those of panthers localized in more southern parts of Florida (7.148 x 10(6) +/- 1.045 x 10(6)/microliter, 11.60 +/- 1.62 g/dl, and 34.82 +/- 5.99%, respectively). Adults had significantly higher mean serum total protein (7.50 +/- 0.59 g/dl) and packed cell volume (36.90 +/- 4.97%) values than juveniles (6.88 +/- 0.49 g/dl and 34.54 +/- 5.30%). However, mean serum albumin concentrations were significantly higher in juveniles (3.80 +/- 0.26 g/dl) when compared to adult values (3.58 +/- 0.26 g/dl). Mean serum calcium concentrations were significantly higher in juveniles (10.33 +/- 0.39 mg/dl) than in adults (9.66 +/- 0.45 mg/dl). Additionally, mean serum iron concentrations were significantly higher in those panthers of intergrade genetic stock compared to values in those of authentic genetic stock (105.6 +/- 72.1 micrograms/dl versus 59.3 +/- 19.7 micrograms/dl, respectively).

Comprehensive and comparative ecotoxicological and human risk assessment of polycyclic aromatic hydrocarbons (PAHs) in reef surface sediments and coastal seawaters of Iranian Coral Islands, Persian Gulf.

PubMed

Ranjbar Jafarabadi, Ali; Riyahi Bakhtiari, Alireza; Shadmehri Toosi, Amirhossein

2017-11-01

The concentration and spatial distribution along with ecotoxicological risk of 30 polycyclic aromatic hydrocarbons were investigated in the reef surface sediments (RSSs) and coastal seawater (CSW) of ten coral Islands from the Persian Gulf, Iran, in January 2015. For all sampling sites, assessment of ecological risk was undertaken using several approaches. Mean concentration of ∑30PAHs varied between 70 and 884ngL -l with an overall mean value of 464ngL -l in the CSW, while the RSS ranged from 274 to 1098ngg -1 dw with a total average of 619ngg -1 dw. The results showed a gradient in PAH concentration and toxicity estimates from the northern Hormoz site increasing to the eastern Kharg site. Most of the toxicity estimates were in the moderate range or less than risk values for damage to the marine environment. The calculated Dermal Hazard Quotient (HQs), the sum of HQs (HI) and other cancer risk values of most compounds were less than safety values at most sites. It means that the possibility of negative effects of PAHs via dermal absorption from sediments for children and adults is low. Some sampling sites studied have already been impacted with hazardous pollutants for an extended period of time and evidence from this investigation demonstrates that mixtures of PAHs may be carcinogenic to humans, especially in the western part of the Gulf. Copyright © 2017 Elsevier Inc. All rights reserved.

Sediment transport and water-quality characteristics and loads, White River, northwestern Colorado, water years 1975-88

USGS Publications Warehouse

Tobin, R.L.

1993-01-01

Streamflow, sediment, and water-quality data are summarized for 6 sites on the White River, Colorado for water years 1975-88. Correlation techniques were used to estimate annual data for unmeasured years. Annual stream discharge in the main stem of the White River ranged from about 200,000 to about 1 million acre-feet. Generally, bedload was less than/= 3.3 percent of total sediment load. Annual suspended-sediment loads ranged from about 2,100 tons at the upstream sites on the North Fork and South Fork of the White River to about 2 million tons at the most downstream site. Average annual suspended-sediment loads ranged from about 11,000 tons at the upstream sites to about 705,000 tons at the most downstream site. Annual capacity losses in a 50,000 acre-ft reservoir could range from less than 0.01 percent near upstream sites to about 2.5 percent near downstream sites. Maximum water temperatures in the White River ranged from less than 20 to 25 C in summer. Specific conductance ranged from 200 to 1,000 microsiemens/cm. Generally, values of pH ranged from 7.6 to 8.8, and concentrations of dissolved oxygen were greater than 6.0 mg/L. In small streamflows, values of pH and dissolved oxygen were affected by biologic processes. Composition of dissolved solids in the White River was mostly calcium, bicarbonate, and(or) sulfate. Changes in the composition of dissolved solids caused by the changes in the concentrations of sodium and sulfate were greatest in small stream discharges. Annual loads of dissolved solids ranged from 21,100 tons in the South Fork to about 480,000 tons at the most downstream site. Total solids transport in the White River was mostly as dissolved solids at upstream sites and mostly as suspended sediment at downstream sites. Concentration ranges of nutrients and trace constituents were determined.

Initial effects of Stagecoach Reservoir on discharge, water-quality characteristics, and suspended-sediment loads in the Yampa River, northwestern Colorado

USGS Publications Warehouse

Tobin, R.L.

1996-01-01

The construction and filling of Stagecoach Reservoir on the Yampa River during 1988-91 were done to enhance water management and to use local water resources. To assess the initial effects of the reservoir on the hydrology of the upper Yampa River, physical, chemical, and biological data were collected at a site upstream (YR-1) during water years 1989-92 and a site downstream (YR-2) from the reservoir during water years 1985-92 and at two sites in the reservoir during 1990-92. Annual suspended-sediment loads were determined for the Yampa River for water years 1985-92, and sediment retention in Stagecoach Reservoir was estimated. The initial filling of the 33,275-acre-foot reservoir proceeded slower than expected because inflow from the Yampa River was about 50 to 73 percent of average during water years 1989-91. Secchi-disk measurements in Stagecoach Reservoir ranged from 2.5 to 18 feet. Algal growth and sediment transport during stormy weather decreased water clarity, and possible algal grazing by zooplankton and sediment deposition improved water clarity. Water temperature in the reservoir ranged from 0 to 22 degrees Celsius, and thermal stratification was maintained during summer. Values of pH ranged from 7.2 in the hypolimnion to 8.9 in the epilimnion. Changes in pH were related to photosynthesis and respiration. Concentrations of dissolved oxygen in the reservoir ranged from 0 milligram per liter in the hypolimnion to 13 milligrams per liter in the epilimnion. Average 5-day biochemical-oxygen-demand rates ranged from 0.33 to 0.46 milligram per liter per day. Oxygen production from photosynthesis was greatest in the epilimnion; oxygen depletion from respiration was characteristic in the hypolimnion. Near or above average inflow might decrease the incidence of anaerobic conditions. Specific conductance in the reservoir ranged from 414 to 520 microsiemens per centimeter at 25 degrees Celsius, depending on the specific conductance of inflow from the Yampa River. The water was a very hard, calcium bicarbonate type. Nitrogen input to the reservoir was mostly as organic nitrogen that ranged in concentration from less than 0.18 to about 1.0 milligram per liter. Concentrations of dissolved phosphorus in the inflow of the Yampa River ranged from less than 0.01 to 0.06 milligram per liter. Decomposition of organic material and release of nutrients from sediments under reducing conditions were probable causes for dissolved-ammonia concentrations near the reservoir bottom to increase to maximum values of 0.9 to 1.6 milligrams per liter as nitrogen during thermal stratification in summer. Dissolved phosphorus also increased in the same conditions to a range of 0.32 to 0.35 milligram per liter. Except for concentrations of total recoverable manganese that ranged from 210 to 440 micrograms per liter near the reservoir bottom, most concentrations of 20 trace constituents were measured at or near analytical detection limits. A total of 119 phytoplankton from 7 phyla was identified in Stagecoach Reservoir during 1990-92. Cyanophyta (blue-green algae) accounted for most of the cell counts. Cyanophyta blooms of Aphanizomenon and Aphanocapsa developed during 1990-92, and photosynthesis caused concentrations of dissolved oxygen to exceed 150-percent saturation in the epilimnion. Diversity index values for phytoplankton ranged from 0.05 to 3.06. Values of diversity index during the summer of 1992 indicated that the community diversity of algae could be greatest in spring and least in fall. All colony counts of fecal coliform bacteria in the reservoir during 1990-92 were less than criteria limits set by the State of Colorado. During water years 1985-88 (preconstruction period), at a site on the Yampa River downstream from the proposed damsite, and water years 1989-92 (post-construction period), at a site upstream from the dam, annual loads of suspended sediment ranged from 2,480 to 22,650 tons. The average annual suspended-sediment load for th

Graphene-metallic nanocomposites as modifiers in electrochemical glucose biosensor transducers

NASA Astrophysics Data System (ADS)

Altuntas, Derya Bal; Tepeli, Yudum; Anik, Ulku

2016-09-01

Graphene sheets and three different graphene-metallic nanocomposites including graphene-copper (graphene-Cu), graphene-nickel (graphene-Ni) and graphene-platinum (graphene-Pt) were prepared and characterized in the first place. Then the electrochemical performances of these nanocomposites were tested in glucose biosensor transducers, which were formed by combining these metallic nanocomposites with glucose oxidase enzyme and glassy carbon paste electrode (GCPE). This is the first work that includes the usage of these graphene-Me nanocomposites as a part of glucose biosensor transducer. Fabricated amperometric biosensors linear ranges were obtained as follow: For the plain graphene, the linear range was found in the concentration range between 50 μM and 800 μM with the RSD (n = 3 for 50 μM glucose) value of 12.86% and LOD value of 7.2 μM. For graphene-Pt modified glucose biosensor, the linear range was between 10 μM and 600 μM with the RSD (n = 3 for 50 μM glucose) value of 3.45% and LOD value of 3.06 μM. In the case of graphene-Ni modified glucose biosensor, the values were 25 μM to 600 μM with the RSD (n = 3 for 50 μM glucose) value of 8.76% and LOD value of 24.71 μM and for graphene-Cu modified glucose biosensor linear range was 25 μM to 400 μM with the RSD (n = 3 for 50 μM glucose) value of 3.93% and LOD value of 2.87 μM.

Influence of pH for the determination of serum albumin by a dye-binding method in the presence of a detergent.

PubMed

Suzuki, Yuji

2008-08-01

In the dye-binding method, the absorbance increase caused by a protein error of a pH indicator is observed only in a restricted pH range. However, this pH range in the presence of a detergent has not yet been examined. Thus, the author investigated the pH (pH(UL)) where the absorbance increase becomes zero by a calculation based on the chemical equilibrium of a protein error of a pH indicator, and by experiments using four sulfonephthalein dyes. The pH(UL) value changed only with the detergent concentration, but did not change at all due to the dye, buffer solution or protein concentrations. Although the pH(UL) value was different according to the kind of dye used, it correlated well with the pK(D) values (dissociation constant) of BPB, BCG, BCP and BTB. The characteristics of pH(UL) in the reactions of the four dyes indicated good agreement with that obtained by a calculation.

Quantitative measurement of natural radioactivity in some roofing tile materials used in upper Egypt.

PubMed

Uosif, M A M

2013-09-01

The quantitative measurement of radionuclides ((226)Ra, (232)Th and (40)K) in some roofing tile materials (granite, alabaster, marble, traditional and advanced ceramic) used in Upper Egypt is presented in this paper. Measurements were done by using gamma spectrometry (NaI (Tl) 3" × 3"). The values of concentration of natural radionuclides were in the following ranges: 12-78.9 Bq kg(-1) for (226)Ra, 8.4-113.1 Bq kg(-1) for (232)Th and 94.9-509 Bq kg(-1)for (40)K. The activity concentration index (I), the specific dose rates indoors ( ) and the annual effective dose (DE) due to gamma radiation were calculated for each investigated sample. The lowest value of I is 0.19 for alabaster, while the highest one is 0.88 for traditional and advanced ceramic. The ranges of DE are between 0.03 and 0.13 mSv, it is below the maximal permitted values, so that the examined materials could be used as roofing tiles in the construction of new buildings.

Identification and quantification of the main isoflavones and other phytochemicals in soy based nutraceutical products by liquid chromatography-orbitrap high resolution mass spectrometry.

PubMed

López-Gutiérrez, Noelia; Romero-González, Roberto; Garrido Frenich, Antonia; Martínez Vidal, José Luis

2014-06-27

The specific phytochemicals composition of soy nutritional supplements is usually not labelled. Hence, 12 dietary supplements were analyzed in order to detect and identify the main phytochemicals present in these samples, using a database containing 60 compounds. Ultra-high performance liquid chromatography coupled to single-stage Orbitrap high resolution mass spectrometry (UHPLC-Orbitrap-MS) has been used. Two consecutive extractions, using as extraction solvent a mixture of methanol:water (80:20, v/v), were employed, followed by two dilutions (10 or 100 times depending on the concentration of the components in the sample) with a mixture of an aqueous solution of ammonium acetate 30mM:methanol (50:50, v/v). The method was validated, obtaining adequate recovery and precision values. Limits of detection (LODs) and quantification (LOQs) were calculated, ranging from 2 to 150μgL(-1). Isoflavones were the predominant components present in the analyzed supplements with values higher than 93% of the total amount of phytochemicals in all cases. The aglycones (genistein, daidzein, glycitein and biochanin A) as well as their three conjugated forms, β-glucosides (genistin, daizin and glycitin) were detected and quantified, being daidzein the isoflavone detected at higher concentration in 8 out of 12 samples reported, with values ranging from 684 to 35,970mgkg(-1), whereas biochanin A was detected at very low concentrations, ranging from 18 to 50mgkg(-1). Moreover, other phytochemicals as flavones, flavonols, flavanones and phenolic acids were also detected and quantified. Copyright © 2014 Elsevier B.V. All rights reserved.

Occurrence of hexavalent chromium in ground water in the western Mojave Desert, California

USGS Publications Warehouse

Ball, J.W.; Izbicki, J.A.

2004-01-01

About 200 samples from selected public supply, domestic, and observation wells completed in alluvial aquifers underlying the western Mojave Desert were analyzed for total dissolved Cr and Cr(VI). Because Cr(VI) is difficult to preserve, samples were analyzed by 3 methods. Chromium(VI) was determined in the field using both a direct colorimetric method and EPA method 218.6, and samples were speciated in the field for later analysis in the laboratory using a cation-exchange method developed for the study described in this paper. Comparison of the direct colorimetric method and EPA method 218.6 with the new cation-exchange method yielded r2 values of 0.9991 and 0.9992, respectively. Total dissolved Cr concentrations ranged from less than the 0.1 ??g/l detection limit to 60 ??g/l, and almost all the Cr present was Cr(VI). Near recharge areas along the mountain front pH values were near neutral, dissolved O2 concentrations were near saturation, and Cr(VI) concentrations were less than the 0.1 ??g/l detection limit. Chromium(VI) concentrations and pH values increased downgradient as long as dissolved O 2 was present. However, low Cr(VI) concentrations were associated with low dissolved O2 concentrations near ground-water discharge areas along dry lakes. Chromium(VI) concentrations as high as 60 ??g/l occurred in ground water from the Sheep Creek fan alluvial deposits weathered from mafic rock derived from the San Gabriel Mountains, and Cr(VI) concentrations as high as about 36 ??g/l were present in ground water from alluvial deposits weathered from less mafic granitic, metamorphic, and volcanic rocks. Chromium(III) was the predominant form of Cr only in areas where dissolved O2 concentrations were less than 1 mg/l and was detected at a median concentration of 0.1 ??g/l, owing to its low solubility in water of near-neutral pH. Depending on local hydrogeologic conditions and the distribution of dissolved O2, Cr(VI) concentrations may vary considerably with depth. Samples collected under pumping conditions from different depths within wells show that Cr(VI) concentrations can range from less than the 0.1 ??g/l detection limit to 36 ??g/l in a single well and that dissolved O2 concentrations likely control the concentration and redox speciation of Cr in ground water.

Modeling the movement of a pH perturbation and its impact on adsorbed zinc and phosphate in a wastewater‐contaminated aquifer

USGS Publications Warehouse

Kent, D.B.; Wilkie, J.A.; Davis, J.A.

2007-01-01

Chemical conditions were perturbed in an aquifer with an ambient pH of 5.9 and wastewater‐derived adsorbed zinc (Zn) and phosphate (P) contamination by injecting a pulse of amended groundwater. The injected groundwater had low concentrations of dissolved Zn and P, a pH value of 4.5 resulting from equilibration with carbon dioxide gas, and added potassium bromide (KBr). Downgradient of the injection, breakthrough of nonreactive Br and total dissolved carbonate concentrations in excess of ambient values (excess TCO2) were accompanied by a decrease in pH values and over twentyfold increases in dissolved Zn concentrations above preinjection values. Peak concentrations of Br and excess TCO2 were followed by slow increases in pH values accompanied by significant increases in dissolved P above preinjection concentrations. The injected tracers mobilized a significant mass of wastewater‐derived Zn. Reactive transport simulations incorporating surface complexation models for adsorption of Zn, P, hydrogen ions, and major cations onto the aquifer sediments, calibrated using laboratory experimental data, captured most of the important trends observed during the experiment. These include increases in Zn concentrations in response to the pH perturbation, perturbations in major cation concentrations, attenuation of the pH perturbation with transport distance, and increases in alkalinity with transport distance. Observed desorption of P in response to chemical perturbations was not predicted, possibly because of a disparity between the range of chemical conditions in the calibration data set and those encountered during the field experiment. Zinc and P desorbed rapidly in response to changing chemical conditions despite decades of contact with the sediments. Surface complexation models with relatively few parameters in the form of logK values and site concentrations show considerable promise for describing the influence of variable chemistry on the transport of adsorbing contaminants.

Absolute paleobathymetry of Upper Cretaceous chalks based on ostracodes - Evidence from the Demopolis Chalk (Campanian and Maastrichtian) of the northern Gulf Coastal Plain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Puckett, T.M.

1991-05-01

The presence of abundant and diverse sighted ostracodes in chalk and marl of the Demopolis Chalk (Campanian and Maastrichtian) in Alabama and Mississippi strongly suggests that the Late Cretaceous sea floor was within the photic zone. The maximum depth of deposition is calculated from an equation based on eye morphology and efficiency and estimates of the vertical light attenuation. In this equation, K, the vertical light attenuation coefficient, is the most critical variable because it is the divisor for the rest of the equation. Rates of accumulation of coccoliths during the Cretaceous are estimated and are on the same ordermore » as those in modern areas of high phytoplankton production, suggesting similar pigment and coccolith concentrations in the water column. Values of K are known for a wide range of water masses and pigment concentrations, including areas of high phytoplankton production; thus light attenuation through the Cretaceous seas can be estimated reliably. Waters in which attenuation is due only to biogenic matter-conditions that result in deposition of relatively pure chalk-have values of K ranging between 0.2 and 0.3. Waters rich in phytoplankton and mud-conditions that result in deposition of marl-have K values as great as 0.5. Substituting these values for K results in depth range of 65 to 90 m for deposition of chalk and depth of 35 m for deposition of marl. These depth values suggest that deposition of many Cretaceous chalks and marls around the world were deposited under relatively shallow conditions.« less

Evaluation of Hematocrit Influence on Self-Monitoring of Blood Glucose Based on ISO 15197:2013: Comparison of a Novel System With Five Systems With Different Hematocrit Ranges.

PubMed

Hattemer, Andrew; Wardat, Sami

2018-03-01

ISO 15197:2013 recommends testing procedures and acceptance criteria for the evaluation of influence quantities such as hematocrit on measurement results with systems for self-monitoring of blood glucose (SMBG). In this study, hematocrit influence was evaluated for a novel SMBG system (system A) and five other systems with different hematocrit ranges based on ISO 15197:2013. Test procedures were performed with one test strip lot for each system. Each system was tested within the hematocrit range indicated in the manufacturer's labeling (system A: 10-65%, B: 15-65%, C: 20-60%, D: 35-60%, E: 30-60%, F: 30-55%). According to ISO 15197:2013, clause 6.4.2, venous blood samples were used for the evaluation of hematocrit influence. The evaluation was performed for three glucose concentration categories (30-50 mg/dL, 96-144 mg/dL, and 280-420 mg/dL). For each glucose concentration category, at least five different hematocrit levels were investigated. The novel system A and systems B, E, and F complied with the tested lot with the defined criteria and showed ≤10 mg/dL and ≤10% difference between the test sample and the respective control sample with a hematocrit value of 42% ± 2% for BG concentrations <100 mg/dL and ≥100 mg/dL, respectively. Two systems showed >10% difference at glucose concentrations ≥100 mg/dL. Remarkable hematocrit influence within the labeled hematocrit range was obtained in two systems with the tested reagent system lot. Adequate SMBG systems should be carefully chosen by patients and their health care professionals, particularly for patients with increased and decreased hematocrit values.

Monsoon-driven transport of atmospheric mercury to the South China Sea from the Chinese mainland and Southeast Asia-Observation of gaseous elemental mercury at a background station in South China.

PubMed

Liu, Ming; Chen, Laiguo; Xie, Donghai; Sun, Jiaren; He, Qiusheng; Cai, Limei; Gao, Zhiqiang; Zhang, Yiqiang

2016-11-01

Concentrations of gaseous elemental mercury (GEM) were continuously monitored from May 2011 to May 2012 at the Wuzhishan State Atmosphere Background Monitoring Station (109°29'30.2″ E, 18°50'11.0″ N) located in Hainan Island. This station is an ideal site for monitoring long-range transport of atmospheric pollutants from mainland China and Southeast Asia to South China Sea. Annual average GEM concentration was 1.58 ± 0.71 ng m -3 during the monitoring period, which was close to background values in the Northern Hemisphere. GEM concentrations showed a clear seasonal variation with relatively higher levels in autumn (1.86 ± 0.55 ng m -3 ) and winter (1.80 ± 0.62 ng m -3 ) and lower levels in spring (1.16 ± 0.45 ng m -3 ) and summer (1.43 ± 0.46 ng m -3 ). Long-range atmospheric transport dominated by monsoons was a dominant factor influencing the seasonal variations of GEM. The GEM diel trends were related to the wind speed and long-range atmospheric mercury transport. We observed 30 pollution episodes throughout the monitoring period. The analysis of wind direction and backward trajectory suggested that elevated GEM concentrations at the monitoring site were primarily related to the outflows of atmospheric Hg from mainland China and the Indochina peninsula. The △GEM/△CO values also suggested that GEM was significantly affected by the long-range transport from the anthropogenic sources and biomass burning in Asia and Indochina peninsula.

PREECLAMPSIA AND SMALL FOR GESTATIONAL AGE ARE ASSOCIATED WITH DECREASED CONCENTRATIONS OF A FACTOR INVOLVED IN ANGIOGENESIS: SOLUBLE TIE-2

PubMed Central

Gotsch, Francesca; Romero, Roberto; Kusanovic, Juan Pedro; Chaiworapongsa, Tinnakorn; Dombrowski, Michael; Erez, Offer; Than, Nandor Gabor; Mazaki-Tovi, Shali; Mittal, Pooja; Espinoza, Jimmy; Hassan, Sonia S

2009-01-01

OBJECTIVE An anti-angiogenic state has been described in patients with preeclampsia, small for gestational age (SGA) fetuses and fetal death, and changes in the concentration of circulating angiogenic and anti-angiogenic factors can precede the clinical recognition of preeclampsia and small for gestational age by several weeks. Gene deletion studies demonstrate that a selective group of endothelial growth factors are required for vascular development, including members of the vascular endothelial growth factor (VEGF) family, as well as Angiopoietin-1 and Angiopoietin-2, both ligands for the tyrosine kinase endothelial cell receptor Tie-2. These angiogenic factors have been proposed to promote angiogenesis in a coordinated and complementary fashion. Soluble Tie-2 (sTie-2) is the soluble form of the Tie-2 receptor which is detectable in biological fluids. The purpose of this study was to determine whether patients with preeclampsia and mothers who deliver a small for gestational age neonate have changes in the plasma concentrations of sTie-2. STUDY DESIGN This cross-sectional study included patients in the following groups: 1) non-pregnant women (n=40); 2) women with normal pregnancies (n=135); 3) patients with preeclampsia (n=112); and 4) patients who delivered a small for gestational age (SGA) neonate (n=53). Maternal plasma concentrations of sTie-2 were measured by a sensitive immunoassay. Parametric statistics were used for analysis. RESULTS 1) The median maternal plasma concentration of sTie-2 was lower in normal pregnant women than in non-pregnant women [median 16.0 ng/ml (range 5.0–71.6) vs. median 20.7 ng/ml (range 10.8–52.4), respectively; p=0.01)]; 2) Plasma sTie-2 concentrations in normal pregnancy changed significantly as a function of gestational age; 3) Patients with preeclampsia and those who delivered SGA neonates had a lower median maternal plasma concentration of sTie-2 than those with a normal pregnancy [Preeclampsia: median 14.9 ng/ml (range 4.9–67.3); SGA: median 10.9 ng/ml (range 5.1–29.1); Normal pregnancy: median 16.0 ng/ml (range 5.0–71.6); p=0.048 and p<0.001, respectively]; 4) Patients with SGA neonates had a lower median plasma concentration of sTie-2 than that of those with preeclampsia [median 10.9 ng/ml (range 5.1–29.1) vs. median 14.9 ng/ml (range 4.9–67.3), respectively; p<0.001)]; and 5) Patients with early-onset preeclampsia (≤34 weeks) had lower concentrations of sTie-2 than women with late-onset preeclampsia (>34 weeks) [median of delta values: −0.13 ng/ml (range −0.47–0.58) vs. median of delta values: −0.09 ng/ml (range: −0.60–0.58), respectively; p=0.043]. In contrast, there were no significant differences in the maternal plasma sTie-2 concentration between women with severe and mild preeclampsia (p=0.6). CONCLUSION Patients with preeclampsia and those with SGA fetuses have lower median plasma concentrations of soluble Tie-2 than women with normal pregnancies. PMID:18570117

Interleukin-6 and tumor necrosis factor-alpha values in elk neonates

USGS Publications Warehouse

Barber-Meyer, S. M.; Johnson, C.R.; Murtaugh, M.P.; Mech, L.D.; White, P.J.

2007-01-01

Serological indicators of general condition would be helpful for monitoring or assessing ungulate wildlife. Toward that end, we report the 1st reference values for 2 cytokines, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-??), in neonatal elk (Cervus elaphus). We obtained blood samples from 140 calves ??? 6 days old in Yellowstone National Park during summer 2003-2005. TL-6 values ranged from 0 to 1.21 pg/ml with a median of 0.03 pg/ml. TNF-?? values ranged from 0 to 225.43 pg/ml with a median of 1.85 pg/ml. IL-6 and TNF-?? concentrations were not significant predictors of elk calf survival through 21 days. Development of ungulate-based IL-6 and TNF-?? assays that provide greater sensitivity than cross-reacting human-based assays could be helpful in monitoring ungulate condition and health status comparisons among herds. Such information could provide indirect assessments of range quality or environmental influences among herds. 

A critical evaluation of liquid chromatography with hybrid linear ion trap-Orbitrap mass spectrometry for the determination of acidic contaminants in wastewater effluents.

PubMed

Cahill, Michael G; Dineen, Brian A; Stack, Mary A; James, Kevin J

2012-12-28

Acidic pesticide and pharmaceutical contaminants were pre-concentrated and extracted from wastewater samples (500 mL) using solid-phase extraction. Analyte recoveries were 79-96%, with % RSD values in the range, 1.7-7.4%. Analyte identification and quantification were carried out using liquid chromatography-mass spectrometry (LC-MS) with hybrid linear ion trap (LIT) Orbitrap instrumentation. Using a resolution setting of 30,000 FWHM, full-scan MS analysis was performed using heated electrospray ionization (HESI) in negative mode. The high mass resolution capabilities of the Orbitrap MS were exploited for the determination of trace contaminants allowing facile discrimination between analytes and matrix. The dependant scan functions of the Orbitrap MS using higher collisional dissociation (HCD) and LIT MS were evaluated for the confirmation of analytes at trace concentration levels. Mass accuracy for target contaminants using this method was less than 2 ppm. The limits of quantitation (LOQs) were in the range, 2.1-27 ng/L. The inter-day accuracy and precision were measured over a five-day period at two concentrations. The % relative errors were in the range, 0.30-7.7%, and the % RSD values were in the range, 1.5-5.5%. Using this method, 2,4-D, mecoprop, ibuprofen, naproxene and gemfibrozil were identified in several wastewater treatment plants in Ireland. Copyright © 2012 Elsevier B.V. All rights reserved.

Vanadium bioavailability and toxicity to soil microorganisms and plants.

PubMed

Larsson, Maja A; Baken, Stijn; Gustafsson, Jon Petter; Hadialhejazi, Golshid; Smolders, Erik

2013-10-01

Vanadium, V, is a redox-sensitive metal that in solution, under aerobic conditions, prevails as the oxyanion vanadate(V). There is little known regarding vanadium toxicity to soil biota, and the present study was set up to determine the toxicity of added vanadate to soil organisms and to investigate the relationship between toxicity and vanadium sorption in soils. Five soils with contrasting properties were spiked with 7 different doses (3.2-3200 mg V kg(-1)) of dissolved vanadate, and toxicity was measured with 2 microbial and 3 plant assays. The median effective concentration (EC50) thresholds of the microbial assays ranged from 28 mg added V kg(-1) to 690 mg added V kg(-1), and the EC50s in the plant assays ranged from 18 mg added V kg(-1) to 510 mg added V kg(-1). The lower thresholds were in the concentration range of the background vanadium in the untreated control soils (15-58 mg V kg(-1)). The vanadium toxicity to plants decreased with a stronger soil vanadium sorption strength. The EC50 values for plants expressed on a soil solution basis ranged from 0.8 mg V L(-1) to 15 mg V L(-1) and were less variable among soils than corresponding values based on total vanadium in soil. It is concluded that sorption decreases the toxicity of added vanadate and that soil solution vanadium is a more robust measure to determine critical vanadium concentrations across soils. © 2013 SETAC.

[Size distributions of aerosol during the Spring Festival in Nanjing].

PubMed

Wang, Hong-Lei; Zhu, Bin; Shen, Li-Juan; Liu, Xiao-Hui; Zhang, Ze-Feng; Yang, Yang

2014-02-01

In order to investigate the firework burning impacts on spectrum distribution of atmospheric aerosol during the Spring Festival in Nanjing, number concentration and mass concentration of aerosol as well as mass concentration of gas pollutants were measured during January 19-31, 2012. The results indicated that the concentration of aerosol between 10-20 nm decreased, aerosol concentration in the range of 50-100 nm, 100-200 nm and 200-500 nm increased during the firework burning period comparing to those during the non-burning period. However, there was no obvious variation for aerosol between 20-50 nm and 0.5-10 microm. The spectrum distribution of number concentration was bimodal during the non-burning period and unimodal during the burning period, with the peak value shifting to large diameter section. The mass concentration presented a bimodal distribution, the value of PM2.5/PM10 and PM10/PM10 increased by 10% during the burning period. The firework burning events had big influence on the density of aerosol between 1.0-2.1 microm.

Study of the effect of electromagnetic fields on indoor and outdoor radon concentrations

NASA Astrophysics Data System (ADS)

Haider, Lina M.; Shareef, N. R.; Darwoysh, H. H.; Mansour, H. L.

2018-05-01

In the present work, the effect of electromagnetic fields produced by high voltage power lines(132kV) and indoor equipments on the indoor and outdoor average radon concentrations in Al-Kazaliya and Hay Al-Adil regions in Baghdad city were studied using CR-39 track detectors and a gauss-meter.Results of measurements of the present study, have shown that the highest value for the indoor average radon concentration (76.56± 8.44 Bq / m3) was recorded for sample A1(Hay Al-Adel) at a distance of (20 m) from the high voltage power lines, while the lowest value for the indoor average radon concentration (30.46 ± 8.44 Bq / m3) was recorded for sample A3 (Hay Al-Adil) at a distance of (50 m) from the high voltage power lines. The indoor gaussmeter measurements were found to be ranged from (30.2 mG) to (38.5 mG). The higest value for outdoor average radon concentration and the highest gaussmeter measurements were found for sample (1), with values (92.63 ±11.2 Bq / m3) and (87.24 ± 2.85 mG), directly under the high voltage power lines respectively, while the lowest outdoor average radon concentration and the lowest gaussmeter measurements were found in sample (4),with values (34.19 ± 6.33 Bq / m3) and (1.16 ± 0.14 Bq / m3),), at a distance of (120 m) from the high voltage power lines respectively. The results of the present work have shown that there might be an influence of the electromagnetic field on radon concentrations in areas which were close to high voltage power lines and houses which have used many electric equipment for a long period of time.

Cerebrospinal Fluid Glucose and Lactate: Age-Specific Reference Values and Implications for Clinical Practice

PubMed Central

Leen, Wilhelmina G.; Willemsen, Michèl A.; Wevers, Ron A.; Verbeek, Marcel M.

2012-01-01

Cerebrospinal fluid (CSF) analysis is an important tool in the diagnostic work-up of many neurological disorders, but reference ranges for CSF glucose, CSF/plasma glucose ratio and CSF lactate based on studies with large numbers of CSF samples are not available. Our aim was to define age-specific reference values. In 1993 The Nijmegen Observational CSF Study was started. Results of all CSF samples that were analyzed between 1993 and 2008 at our laboratory were systematically collected and stored in our computerized database. After exclusion of CSF samples with an unknown or elevated erythrocyte count, an elevated leucocyte count, elevated concentrations of bilirubin, free hemoglobin, or total protein 9,036 CSF samples were further studied for CSF glucose (n = 8,871), CSF/plasma glucose ratio (n = 4,516) and CSF lactate values (n = 7,614). CSF glucose, CSF/plasma glucose ratio and CSF lactate were age-, but not sex dependent. Age-specific reference ranges were defined as 5–95th percentile ranges. CSF glucose 5th percentile values ranged from 1.8 to 2.9 mmol/L and 95th percentile values from 3.8 to 5.6 mmol/L. CSF/plasma glucose ratio 5th percentile values ranged from 0.41 to 0.53 and 95th percentile values from 0.82 to 1.19. CSF lactate 5th percentile values ranged from 0.88 to 1.41 mmol/L and 95th percentile values from 2.00 to 2.71 mmol/L. Reference ranges for all three parameters were widest in neonates and narrowest in toddlers, with lower and upper limits increasing with age. These reference values allow a reliable interpretation of CSF results in everyday clinical practice. Furthermore, hypoglycemia was associated with an increased CSF/plasma glucose ratio, whereas hyperglycemia did not affect the CSF/plasma glucose ratio. PMID:22880096

Sequential concentrations of placental growth factor and haptoglobin, and their relation to oestrone sulphate and progesterone in pregnant Spanish Purebred mare.

PubMed

Satué, K; Marcilla, M; Medica, P; Ferlazzo, A; Fazio, E

2018-04-27

The objectives of this study were to establish reference values for serum concentrations of placental growth factor (PlGF) and haptoglobin (Hp), and to analyze whether the levels of oestrone sulphate (E 1 S) and progesterone (P 4 ) are physiologically involved in the dynamic modifications of the above parameters in pregnant mares. A total of 30 healthy Spanish Purebred mares ranging in age 9.33 ± 3.31 years were studied during the 11 months of gestation. Serum concentrations of PlGF were detected by EIA, Hp using commercial Phase Haptoglobin assay and E 1 S and P 4 levels through RIA. The serum concentrations of PlGF ranged between 31.70 and 223.60 ng/mL, with a mean value of 57.64 ± 18.05 ng/mL. Serum PlGF levels increased significantly during the 1st and 2nd months, reaching the maximum value in the 3rd month and the minimum value in the 10th month. Hp concentrations increased progressively and significantly from the 5th until the 10th month of gestation (P < 0.05), decreasing in the 11th month of pregnancy. E 1 S increased significantly from the 3rd until the 7th month, decreasing progressively towards the end of gestation. P 4 increased significantly in the 3rd and 4th month and decreased significantly in the 6th and 7th (P < 0.05), with variable oscillations during last months of pregnancy. PlGF and Hp were significantly and negatively correlated (r = -0.27; P < 0.05). In the healthy mare, PlGF and Hp act asynchronously and independent of steroid E 1 S and P 4. Copyright © 2018 Elsevier Inc. All rights reserved.

Vitamin D concentrations in fortified foods and dietary supplements intended for infants: Implications for vitamin D intake.

PubMed

Verkaik-Kloosterman, Janneke; Seves, S Marije; Ocké, Marga C

2017-04-15

Due to potential overages to cover losses during shelf life, the actual vitamin D concentration of fortified foods and dietary supplements may deviate from the label. In this pilot study the vitamin D concentrations of fortified foods (n=29; follow-on formula, baby porridge, curd cheese dessert) and dietary supplements (n=15), both specifically intended for infants, were analytically determined. Compared to the declared values, the vitamin D content ranged from 50% to 153% for fortified foods and from 8% to 177% for supplements. In general, both instant follow-on formula and oil-based supplements had a measured vitamin D content similar to or higher than the labelled value. Ready-to-eat baby porridge was the only category in which all measured vitamin D concentrations were below the declared value (74-81%). The use of label information for fortified foods and dietary supplements may result in invalid estimations of vitamin D intake distributions of infants; both under- and overestimation may occur. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Degradation of bisphenol A in water by the heterogeneous photo-Fenton.

PubMed

Jiang, Chuanrui; Xu, Zhencheng; Guo, Qingwei; Zhuo, Qiongfang

2014-01-01

Bisphenol A (BPA) is a kind of a controversial endocrine disruptor, and is ubiquitous in environment. The degradation of BPA with the heterogeneous photo-Fenton system was demonstrated in this study. The Fe-Y molecular sieve catalyst was prepared with the ion exchange method, and it was characterized by X-ray radiation diffraction (XRD). The effects ofpH, initial concentration of H2O2, initial BPA concentration, and irradiation intensity on the degradation of BPA were investigated. The service life and iron solubility of catalyst were also tested. XRD test shows that the major phase of the Fe-Y catalyst was Fe2O3. The method of heterogeneous photo-Fenton with Fe-Y catalyst was superior to photolysis, photo-oxidation with only hydrogen, heterogeneous Fenton, and homogeneous photo-Fenton approaches. pH value had no obvious effects on BPA degradation over the range of 2.2-7.2. The initial concentration of H2O2 had an optimal value of 20 x 10(-4) mol/L. The decrease in initial concentration of BPA was favourable for degradation. The intensity of ultraviolet irradiation has no obvious effect on the BPA removal. The stability tests indicated that the Fe-Y catalyst can be reused and iron solubility concentration ranged from NA to 0.0062 mg/L. Based on the results, the heterogeneous photo-Fenton treatment is the available method for the degradation of BPA.

Plant/soil concentration ratios of SSWRa for contrasting sites around an active U mine-mill

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ibrahim, S.A.; Whicker, F.W.

Concentrations of 226Ra were determined in native vegetation and underlying substrate (soil and tailings) at various sites around a conventional open-pit, acid leach U production operation in Wyoming. Plant/soil concentration ratios (CRs) for 226Ra were estimated for various sites, including weathered tailings; a tailings impoundment shoreline; downwind from exposed tailings; a mine overburden reclamation area; and several background locations. Radium-226 concentrations for vegetation and substrate and CR values from the perturbed sites were elevated above background. The highest vegetation concentration (1.3 Bq g-1) was found in a grass which had invaded exposed, weathered tailings. Levels of 226Ra in soil andmore » vegetation and CR values decreased with distance from the tailings impoundment edge. CR values varied significantly among sites, but few differences were found between plant species groups. The observed CR values ranged from 0.07 at the background and reclamation areas to 0.4 downwind from the tailings area. Average CR values for plants growing on exposed tailings and within one meter from the impoundment edge were 0.15 and 0.3, respectively. CR values of 226Ra for plants on tailings substrates were comparatively low in contrast to other radionuclides in the U chain. We speculate that in the case of sulfuric acid leached tailings-derived material, 226Ra is sequestered as sulfate, which is highly insoluble relative to the sulfates of the other elements (e.g., U and Th) resulting in reduced availability for plant uptake.« less

Harmonized Reference Ranges for Circulating Testosterone Levels in Men of Four Cohort Studies in the United States and Europe

PubMed Central

Travison, Thomas G.; Vesper, Hubert W.; Orwoll, Eric; Wu, Frederick; Kaufman, Jean Marc; Wang, Ying; Lapauw, Bruno; Fiers, Tom; Matsumoto, Alvin M.

2017-01-01

Background: Reference ranges for testosterone are essential for making a diagnosis of hypogonadism in men. Objective: To establish harmonized reference ranges for total testosterone in men that can be applied across laboratories by cross-calibrating assays to a reference method and standard. Population: The 9054 community-dwelling men in cohort studies in the United States and Europe: Framingham Heart Study; European Male Aging Study; Osteoporotic Fractures in Men Study; and Male Sibling Study of Osteoporosis. Methods: Testosterone concentrations in 100 participants in each of the four cohorts were measured using a reference method at Centers for Disease Control and Prevention (CDC). Generalized additive models and Bland-Altman analyses supported the use of normalizing equations for transformation between cohort-specific and CDC values. Normalizing equations, generated using Passing-Bablok regression, were used to generate harmonized values, which were used to derive standardized, age-specific reference ranges. Results: Harmonization procedure reduced intercohort variation between testosterone measurements in men of similar ages. In healthy nonobese men, 19 to 39 years, harmonized 2.5th, 5th, 50th, 95th, and 97.5th percentile values were 264, 303, 531, 852, and 916 ng/dL, respectively. Age-specific harmonized testosterone concentrations in nonobese men were similar across cohorts and greater than in all men. Conclusion: Harmonized normal range in a healthy nonobese population of European and American men, 19 to 39 years, is 264 to 916 ng/dL. A substantial proportion of intercohort variation in testosterone levels is due to assay differences. These data demonstrate the feasibility of generating harmonized reference ranges for testosterone that can be applied to assays, which have been calibrated to a reference method and calibrator. PMID:28324103

Metastable equilibria among dicarboxylic acids and the oxidation state during aqueous alteration on the CM2 chondrite parent body

NASA Astrophysics Data System (ADS)

McAlister, Jason A.; Kettler, Richard M.

2008-01-01

Linear saturated dicarboxylic acids are present in carbonaceous chondrite samples at concentrations that suggest aqueous alteration under conditions of metastable equilibrium. In this study, previously published values of dicarboxylic acid concentrations measured in Murchison, Yamato-791198, and Tagish Lake carbonaceous chondrites are converted to aqueous activities during aqueous alteration assuming water:rock ratios that range from 1:10 to 10:1. Logarithmic plots of the aqueous activities of any two dicarboxylic acids are proximal to lines whose slope is fixed by the stoichiometry of reactions describing the oxidation-reduction equilibrium between the two species. The precise position of any line is controlled by the equilibrium constant of the reaction relating the species and the hydrogen fugacity for the reaction of interest. Reactions among succinic (C4), glutaric (C5), and adipic (C6) acids obtained from CM2 chondrites show evidence of metastable equilibrium and yield logf values that agree to within 0.3 log units at 298.15 K and 0.6 log units at 473.15 K. At a water:rock ratio of 1:1, metastable equilibrium among succinic, glutaric, and adipic acids results in calculated logf values during aqueous alteration that range from -6.2 at 298.15 K to -3.3 at 373.15 K. These values are consistent with those obtained in previous work on carbonaceous chondrites and with metastable equilibrium at temperatures ranging from 300 to 355 K in contact with cronstedtite + magnetite.

Quantifying Aerial Concentrations of Maize Pollen in the Atmospheric Surface Layer Using Remote-Piloted Airplanes and Lagrangian Stochastic Modeling

NASA Astrophysics Data System (ADS)

Aylor, Donald E.; Boehm, Matthew T.; Shields, Elson J.

2006-07-01

The extensive adoption of genetically modified crops has led to a need to understand better the dispersal of pollen in the atmosphere because of the potential for unwanted movement of genetic traits via pollen flow in the environment. The aerial dispersal of maize pollen was studied by comparing the results of a Lagrangian stochastic (LS) model with pollen concentration measurements made over cornfields using a combination of tower-based rotorod samplers and airborne radio-controlled remote-piloted vehicles (RPVs) outfitted with remotely operated pollen samplers. The comparison between model and measurements was conducted in two steps. In the first step, the LS model was used in combination with the rotorod samplers to estimate the pollen release rate Q for each sampling period. In the second step, a modeled value for the concentration Cmodel, corresponding to each RPV measured value Cmeasure, was calculated by simulating the RPV flight path through the LS model pollen plume corresponding to the atmospheric conditions, field geometry, wind direction, and source strength. The geometric mean and geometric standard deviation of the ratio Cmodel/Cmeasure over all of the sampling periods, except those determined to be upwind of the field, were 1.42 and 4.53, respectively, and the lognormal distribution corresponding to these values was found to fit closely the PDF of Cmodel/Cmeasure. Model output was sensitive to the turbulence parameters, with a factor-of-100 difference in the average value of Cmodel over the range of values encountered during the experiment. In comparison with this large potential variability, it is concluded that the average factor of 1.4 between Cmodel and Cmeasure found here indicates that the LS model is capable of accurately predicting, on average, concentrations over a range of atmospheric conditions.

The toxicity of Roundup® 360 SL formulation and its main constituents: glyphosate and isopropylamine towards non-target water photoautotrophs.

PubMed

Lipok, Jacek; Studnik, Hanna; Gruyaert, Steven

2010-10-01

The toxicity of commercial formulation of Roundup® 360 SL, widely used, nonselective herbicide and its main constituents, glyphosate (PMG), equimolar (1:1) isopropylamine salt of glyphosate (GIPA) and isopropylamine (IPA) was examined towards eight aquatic microphotoautotrophs; seven cyanobacterial strains representing either saline or freshwater communities, and common eukaryotic algae Chlorella vulgaris Beijerinck. Autotrophs were cultured 21 days in their appropriate standard media supplemented with various amounts of Roundup®, glyphosate, GIPA and IPA. The determination of the growth of examined photoautotrophs was performed by time-course measurements of total chlorophyll content in experimental cultures. The growth rates related to corresponding concentrations of chemicals, the EC(50) values and generation doubling time were determined in order to present the toxicity Roundup® 360 SL formulation and its main constituents. Market available formulation of Roundup® was found to possess toxicity significantly higher than this, attributed to its main constituents; however both these compounds, isopropylamine and glyphosate, also inhibited the growth of examined strains in a dose-dependent manner. Notably, the interpretation of toxicity of the examined substances was found to be significantly dependent on the method of EC(50) calculation. The choice of molar or weight concentration of substances tested separately and in specific formulation was found to be essential in this matter. Due to these findings the EC(50) values were calculated based either on molar or on weight concentrations. Considering Roundup® 360 SL formulation, these values ranged from 10(-3) up to 10(-1) mM and they were one order of magnitude lower than those found for isopropylamine. Quite surprisingly the minimum EC(50) values found for glyphosate did not reach micromolar concentrations, whereas most of the EC(50) values revealed to IPA did not exceed this range. Notably, in all the cases except for Synechocystis aquatilis Sauvageau, isopropylamine alone was indicated as more toxic than glyphosate. Copyright © 2010 Elsevier Inc. All rights reserved.

Concentrations and potential health hazards of polycyclic aromatic hydrocarbon in shallow groundwater of a metal smelting area in Southeastern China.

PubMed

Wu, Chunfa; Zhu, Hao; Luo, Yongming; Wang, Jun

2016-11-01

A total of 20 shallow groundwater samples were collected from a metal smelting area in southeastern China to determine the concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs), calculate their toxic equivalents (TEQs) to benzo[a]pyrene (BaP), and estimate the carcinogenic risk of drinking the shallow groundwater. The total concentrations of the 16PAHs (∑PAHs) in the shallow groundwater ranged from 9.62 to 1663.93ngL(-1), with a mean value of 312.63ngL(-1), and the total concentrations of the 7 potentially carcinogenic PAHs (∑PAHC7) ranged from 3.11 to 33.60ngL(-1), with a mean value of 9.61ngL(-1). Naphthalene and BaP, were the dominant PAH species and potentially carcinogenic PAH species in the shallow groundwater of the study area, and they account for 89.97% of ∑PAHs and 82.62% of ∑PAHC7, respectively. High molecular weight-PAHs (HM-PAHs) accounted for a relatively high proportion in the majority of shallow groundwater samples with lower concentrations of ΣPAHs, indicated that HM-PAHs were mainly from historical residues. The TEQs to BaP of the 16PAHs in the 20 shallow groundwater samples varied greatly from 2.55 to 32.73ngL(-1), with a mean value of 8.61ngL(-1), and BaP was the dominant contributor. The total carcinogenic risk levels caused by the 16PAHs in the shallow groundwater in majority of the area were found to be higher than the limit set by the US EPA, posing a potentially serious health risk to those who depend on shallow groundwater for drinking water. Copyright © 2016. Published by Elsevier B.V.

Human exposure to carcinogens in ambient air in Denmark, Finland and Sweden

NASA Astrophysics Data System (ADS)

Fauser, P.; Ketzel, M.; Becker, T.; Plejdrup, M. S.; Brandt, J.; Gidhagen, L.; Omstedt, G.; Skårman, T.; Bartonova, A.; Schwarze, P.; Karvosenoja, N.; Paunu, V.-V.; Kukkonen, J.; Karppinen, A.

2017-10-01

The concentrations of seventeen pollutants (particulate mass fractions PM2.5 and PM10, a range of metals, inorganic gases and organic compounds) are for the first time analyzed in a screening of the carcinogenic risk at a resolution of 1 × 1 km2 in ambient air in three Nordic countries. Modelled annual mean air concentrations in 2010 show no exceedances of the EU air quality limit, guideline or target values. The only modelled exceedance of US-EPA 1:100,000 cancer risk concentrations (0.12 ng/m3, US-EPA IRIS, 2015) occurs for B(a)P in Denmark, for approximately 80% of the Danish population. However, the EU target value threshold of 1 ng/m3 for B(a)P is not exceeded in the modelled values in any parts of Denmark. No emission data for B(a)P were available for the whole domain of the other two considered Nordic countries and important uncertainties are still related to the emissions. Long-range transport is significant for the concentrations of all of the considered pollutants, except for B(a)P that commonly originates mostly from local residential wood combustion. The ambient air concentrations of NOx, SO2, Cd, Cr and Pb also have significant contributions from national sources; 45-65% for NOx and SO2, and for the metals from 15 to 60% in urban areas and from 1 to 20% in rural areas, within the considered Nordic area. High national contributions occur especially in urban air, due to primarily road traffic, residential wood combustion, energy production and industrial point sources. It is recommended to monitor the influence from residential wood combustion more extensively, and to analyze longer time trends for long-term human exposure.

Chronic aquatic effect assessment for the fungicide azoxystrobin.

PubMed

van Wijngaarden, Rene P A; Belgers, Dick J M; Zafar, Mazhar I; Matser, Arrienne M; Boerwinkel, Marie-Claire; Arts, Gertie H P

2014-12-01

The present study examined the ecological effects of a range of chronic exposure concentrations of the fungicide azoxystrobin in freshwater experimental systems (1270-L outdoor microcosms). Intended and environmentally relevant test concentrations of azoxystrobin were 0 µg active ingredient (a.i.)/L, 0.33 µg a.i./L, 1 µg a.i./L, 3.3 µg a.i./L, 10 µg a.i./L, and 33 µg a.i./L, kept at constant values. Responses of freshwater populations and community parameters were studied. During the 42-d experimental period, the time-weighted average concentrations of azoxystrobin ranged from 93.5% to 99.3% of intended values. Zooplankton, especially copepods and the Daphnia longispina group, were the most sensitive groups. At the population level, a consistent no-observed-effect concentration (NOEC) of 1 µg a.i./L was calculated for Copepoda. The NOEC at the zooplankton community level was 10 µg azoxystrobin/L. The principle of the European Union pesticide directive is that lower-tier regulatory acceptable concentrations (RACs) are protective of higher-tier RACs. This was tested for chronic risks from azoxystrobin. With the exception of the microcosm community chronic RAC (highest tier), all other chronic RAC values were similar to each other (0.5-1 µg a.i./L). The new and stricter first-tier species requirements of the European Union pesticide regulation (1107/2009/EC) are not protective for the most sensitive populations in the microcosm study, when based on the higher tier population RAC. In comparison, the Water Framework Directive generates environmental quality standards that are 5 to 10 times lower than the derived chronic RACs. © 2014 SETAC.

Susceptibility of four tick species, Amblyomma americanum, Dermacentor variabilis, Ixodes scapularis, and Rhipicephalus sanguineus (Acari: Ixodidae), to nootkatone from essential oil of grapefruit.

PubMed

Flor-Weiler, Lina B; Behle, Robert W; Stafford, Kirby C

2011-03-01

Toxicity of nootkatone was determined in laboratory assays against unfed nymphs of Amblyomma americanum L., Dermacentor variabilis (Say), Ixodes scapularis Say, and Rhipicephalus sanguineus Latreille. We determined the 50% lethal concentration (LC50) and 90% lethal concentration (LC90) of nootkatone by recording tick mortality 24 h after exposure in treated glass vials. Nymphs were susceptible to nootkatone with LC50 values of 0.352, 0.233, 0.169, and 0.197 microg/cm2, and LC90 values of 1.001, 0.644, 0.549, and 0.485 microg/cm2 for A. americanum, D. variabilis, I. scapularis, and R. sanguineus, respectively. The LC50 value for R. sanquineus was not significantly different from D. variabilis or I. scapularis. Other LC50 comparisons were significantly different. The LC90 for A. americanum was higher when compared with the three other tick species, which were not significantly different. Because nootkatone is volatile, we measured the amount of nootkatone recovered from duplicate-treated vials before tick exposure and from vials after tick exposure. Nootkatone recovered from vials before exposure ranged from 82 to 112% of the expected amounts. The nootkatone recovered after the 24-h exposure period ranged from 89% from vials coated with higher concentrations of nootkatone, down to 29% from vials coated with low nootkatone concentrations. Determination of the nootkatone residue after vial coating demonstrated loss of the active compound while verifying the levels of tick exposure. Toxicity of low concentrations of nootkatone to the active questing stage of ticks reported in this study provides a reference point for future formulation research to exploit nootkatone as a safe and environment-friendly tick control.

A fluorescence spectroscopy study of traditional Chinese medicine Angelica

NASA Astrophysics Data System (ADS)

Zhao, Hongyan; Song, Feng; Liu, Shujing; Chen, Guiyang; Wei, Chen; Liu, Yanling; Liu, Jiadong

2013-10-01

By measuring the fluorescence spectra of Chinese medicine (CM) Angelica water solutions with different concentrations from 0.025 to 2.5 mg/mL, results showed that the fluorescence intensity was proportional to the concentration. Through fluorescence spectra of Angelica solution under different pH values, results indicated coumarin compounds were the active ingredients of Angelica. We also observed fluorescence quenching of the Angelica solution in the presence of spherical silver nanoparticles with radius of 12 nm. Keeping a certain value for the volume of the silver nanoparticles, the fluorescence intensity at 402 nm was linearly proportional to the Angelica in the range of 1-3 mg/mL.

Evaluation of missing value methods for predicting ambient BTEX concentrations in two neighbouring cities in Southwestern Ontario Canada

NASA Astrophysics Data System (ADS)

Miller, Lindsay; Xu, Xiaohong; Wheeler, Amanda; Zhang, Tianchu; Hamadani, Mariam; Ejaz, Unam

2018-05-01

High density air monitoring campaigns provide spatial patterns of pollutant concentrations which are integral in exposure assessment. Such analysis can assist with the determination of links between air quality and health outcomes, however, problems due to missing data can threaten to compromise these studies. This research evaluates four methods; mean value imputation, inverse distance weighting (IDW), inter-species ratios, and regression, to address missing spatial concentration data ranging from one missing data point up to 50% missing data. BTEX (benzene, toluene, ethylbenzene, and xylenes) concentrations were measured in Windsor and Sarnia, Ontario in the fall of 2005. Concentrations and inter-species ratios were generally similar between the two cities. Benzene (B) was observed to be higher in Sarnia, whereas toluene (T) and the T/B ratios were higher in Windsor. Using these urban, industrialized cities as case studies, this research demonstrates that using inter-species ratios or regression of the data for which there is complete information, along with one measured concentration (i.e. benzene) to predict for missing concentrations (i.e. TEX) results in good agreement between predicted and measured values. In both cities, the general trend remains that best agreement is observed for the leave-one-out scenario, followed by 10% and 25% missing, and the least agreement for the 50% missing cases. In the absence of any known concentrations IDW can provide reasonable agreement between observed and estimated concentrations for the BTEX species, and was superior over mean value imputation which was not able to preserve the spatial trend. The proposed methods can be used to fill in missing data, while preserving the general characteristics and rank order of the data which are sufficient for epidemiologic studies.

Radioactivity level in Chinese building ceramic tile.

PubMed

Xinwei, L

2004-01-01

The activity concentrations of (226)Ra, (232)Th and (40)K have been determined by gamma ray spectrometry. The concentrations of (226)Ra, (232)Th and (40)K range from 158.3 to 1087.6, 91.7 to 1218.4, and 473.8 to 1031.3 Bq kg(-1) for glaze, and from 63.5 to 131.4, 55.4 to 106.5, and 386.7 to 866.8 Bq kg(-1) for ceramic tile, respectively. The measured activity concentrations for these radionuclides were compared with the reported data of other countries and with the typical world values. The radium equivalent activities (Ra(eq)), external hazard index (H(ex)) and internal hazard index (H(in)) associated with the radionuclides were calculated. The Ra(eq) values of all ceramic tiles are lower than the limit of 370 Bq kg(-1). The values of H(ex) and H(in) calculated according to the Chinese criterion for ceramic tiles are less than unity. The Ra(eq) value for the glaze of glazed tile collected from some areas are >370 Bq kg(-1).

Hydration of alcohol clusters in 1-propanol-water mixture studied by quasielastic neutron scattering and an interpretation of anomalous excess partial molar volume.

PubMed

Misawa, M; Inamura, Y; Hosaka, D; Yamamuro, O

2006-08-21

Quasielastic neutron scattering measurements have been made for 1-propanol-water mixtures in a range of alcohol concentration from 0.0 to 0.167 in mole fraction at 25 degrees C. Fraction alpha of water molecules hydrated to fractal surface of alcohol clusters in 1-propanol-water mixture was obtained as a function of alcohol concentration. Average hydration number N(ws) of 1-propanol molecule is derived from the value of alpha as a function of alcohol concentration. By extrapolating N(ws) to infinite dilution, we obtain values of 12-13 as hydration number of isolated 1-propanol molecule. A simple interpretation of structural origin of anomalous excess partial molar volume of water is proposed and as a result a simple equation for the excess partial molar volume is deduced in terms of alpha. Calculated values of the excess partial molar volumes of water and 1-propanol and the excess molar volume of the mixture are in good agreement with experimental values.

Tracing industrial heavy metal inputs to topsoils using using cadmium isotopes

NASA Astrophysics Data System (ADS)

Huang, Y.; Ma, L.; Ni, S.; Lu, H.; Liu, Z.; Zhang, C.; Guo, J.; Wang, N.

2015-12-01

Anthropogenic activities have dominated heavy metal (such as Cd, Pb, and Zn) cycling in many environments. The extent and fate of these metal depositions in topsoils, however, have not been adequately evaluated. Here, we utilize an innovative Cadmium (Cd) isotope tool to trace the sources of metal pollutants in topsoils collected from surrounding a Vanadium Titanium Magnetite smelting plant in Sichuan, China. Topsoil samples and possible pollution end-members such as fly ashes, bottom ashes, ore materials, and coal were also collected from the region surrounding the smelting plant and were analyzed for Cd isotope ratios (d114Cd relative to Cd NIST 3108). Large Cd isotope fractionation (up to 3 ‰) was observed in these industrial end-members: fly ashes possessed higher δ114Cd values ranging from +0.03 to +0.19‰; bottom fly ashes have lower δ114Cd values ranging from -0.35 to -2.46‰; and unprocessed ore and coal samples has δ114Cd value of -0.40‰. This fractionation can be attributed to the smelting processes during which bottom ashes acquired lighter Cd isotope signatures while fly ashes were mainly characterized by heavy isotope ratios, in comparison to the unprocessed ore and coal samples. Indeed, δ114Cd values of topsoils in the smelting area range from 0.29 to -0.56‰, and more than half of the soils analyzed have distinct δ114Cd values > 0‰. Cd isotopes and concentrations measured in topsoils suggested that processed materials (fly and bottom ashes from ore and coal actually used by the smelting plant) were the major source of Cd in soils. In a δ114Cd vs 1/Cd mixing diagram, the soils represent a mixture of three identified end members (fly ash, bottom ash and deep unaffected soil) with distinct Cd isotopic compositions and concentrations. Deep soils have the same δ114Cd values range as the unprocessed ore and coal, which indicated the Cd isotope fractionation did occur during evaporation and condensation processes inside the smelting plant. The signatures of fly ash end member might be even higher according to the δ114Cd increasing trend of topsoils with the increasing of Cd concentration of the topsoils. Our study suggested that δ114Cd values can be used to distinguish sources of anthropogenic Cd and to construct metal budgets in in this studying area.

δ34S and δ18O of dissolved sulfate as biotic tracer of biogeochemical influences on arsenic mobilization in groundwater in the Hetao Plain, Inner Mongolia, China.

PubMed

Li, M D; Wang, Y X; Li, P; Deng, Y M; Xie, X J

2014-12-01

Environmental isotopology of sulfur and oxygen of dissolved sulfate in groundwater was conducted in the Hetao Plain, northwestern China, aiming to better understand the processes controlling arsenic mobilization in arsenic-rich aqueous systems. A total of 22 groundwater samples were collected from domestic wells in the Hetao Plain. Arsenic concentrations ranged from 11.0 to 388 μg/L. The δ(34)S-SO4 and δ(18)O-SO4 values of dissolved sulfate covered a range from +1.48 to +22.4‰ and +8.17‰ to +14.8‰ in groundwater, respectively. The wide range of δ(34)S-SO4 values reflected either an input of different sources of sulfate, such as gypsum dissolution and fertilizer application, or a modification from biogeochemical process of bacterial sulfate reduction. The positive correlation between δ(34)S-SO4 and arsenic concentrations suggested that bacteria mediated processes played an important role in the mobilization of arsenic. The δ(18)O-SO4 values correlated non-linearly with δ(34)S-SO4, but within a relatively narrow range (+8.17 to +14.8‰), implying that complexities inherent in the sulfate-oxygen (O-SO4(2-)) origins, for instance, water-derived oxygen (O-H2O), molecular oxygen (O-O2) and isotope exchanging with dissolved oxides, are accounted for oxygen isotope composition of dissolved sulfate in groundwater in the Hetao Plain.

Solid-phase microextraction method development for headspace analysis of volatile flavor compounds.

PubMed

Roberts, D D; Pollien, P; Milo, C

2000-06-01

Solid-phase microextraction (SPME) fibers were evaluated for their ability to adsorb volatile flavor compounds under various conditions with coffee and aqueous flavored solutions. Experiments comparing different fibers showed that poly(dimethylsiloxane)/divinylbenzene had the highest overall sensitivity. Carboxen/poly(dimethylsiloxane) was the most sensitive to small molecules and acids. As the concentrations of compounds increased, the quantitative linear range was exceeded as shown by competition effects with 2-isobutyl-3-methoxypyrazine at concentrations above 1 ppm. A method based on a short-time sampling of the headspace (1 min) was shown to better represent the equilibrium headspace concentration. Analysis of coffee brew with a 1-min headspace adsorption time was verified to be within the linear range for most compounds and thus appropriate for relative headspace quantification. Absolute quantification of volatiles, using isotope dilution assays (IDA), is not subject to biases caused by excess compound concentrations or complex matrices. The degradation of coffee aroma volatiles during storage was followed by relative headspace measurements and absolute quantifications. Both methods gave similar values for 3-methylbutanal, 4-ethylguaiacol, and 2,3-pentanedione. Acetic acid, however, gave higher values during storage upon relative headspace measurements due to concurrent pH decreases that were not seen with IDA.

Biodegradation of high concentrations of hexadecane by Aspergillus niger in a solid-state system: kinetic analysis.

PubMed

Volke-Sepúlveda, Tania; Gutiérrez-Rojas, Mariano; Favela-Torres, Ernesto

2006-09-01

Solid-state microcosms were used to assess the influence of constant and variable C/N ratios on the biodegradation efficiency by Aspergillus niger at high hexadecane (HXD) concentrations (180-717 mg g-1). With a constant C/N ratio, 100% biodegradation (33-44% mineralization) was achieved after 15 days, at rates increasing as the HXD concentration increased. Biomass yields (YX/S) remained almost independent (approximately 0.77) of the carbon-source amount, while the specific growth rates (mu) decreased with increasing concentrations of HXD. With C/N ratios ranging from 29 to 115, complete degradation was only attained at 180 mg g-1, corresponding to 46% mineralization. YX/S diminished (approximately 0.50 units) as the C/N ratio increased. The highest values of mu (1.08 day-1) were obtained at low C/N values. Our results demonstrate that, under balanced nutritional conditions, high HXD concentrations can be completely degraded in solid-state microcosms, with a negligible (<10%) formation of by-products.

Quality of ground water in Harrison County, Mississippi, June - July 1993

USGS Publications Warehouse

Slack, L.J.; Oakley, W.T.; O'Hara, C. G.; Cooper, L.M.

1994-01-01

During June and July 1993, the U.S. Geological Survey analyzed water from 145 wells in Harrison County, southeastern Mississippi. The wells are completed in five major geologic units: the Citronelle, Graham Ferry, Pascagoula, and Hattiesburg Formations and the Catahoula Sandstone. The wells ranged from 74 to 2,410 feet in depth. Specific conductance (lab) ranged from 15 to 2,020 microsiemens per centimeter; pH (lab), from 5.9 to 9.0; color, from less than 5 to 120 platinum-cobalt units; dissolved-solids concentrations (residue on evaporation), from 20 to 1,120 milligrams per liter; chloride concentrations, from 1.9 to 470 milligrams per liter; and nitrite plus nitrate as nitrogen concentrations, from less than 0.02 to 0.85 milligram per liter. Most of the larger values of specific conductance, pH, dissolved-solids concen- trations, and chloride concentrations were from wells in the southern one-half of the county.

Polychlorinated biphenyls (PCBs) in recreational marina sediments of San Diego Bay, southern California.

PubMed

Neira, Carlos; Vales, Melissa; Mendoza, Guillermo; Hoh, Eunha; Levin, Lisa A

2018-01-01

Polychlorinated biphenyl (PCB) concentrations were determined in surface sediments from three recreational marinas in San Diego Bay, California. Total PCB concentrations ranged from 23 to 153, 31-294, and 151-1387ngg -1 for Shelter Island Yacht Basin (SIYB), Harbor Island West (HW) and Harbor Island East (HE), respectively. PCB concentrations were significantly higher in HE and PCB group composition differed relative to HW and SIYB, which were not significantly different from each other in concentration or group composition. In marina sediments there was a predominance (82-85%) of heavier molecular weight PCBs with homologous groups (6CL-7CL) comprising 59% of the total. In HE 75% of the sites exceeded the effect range median (ERM), and toxicity equivalence (TEQ dioxin-like PCBs) values were higher relative to those of HW and SIYB, suggesting a potential ecotoxicological risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

On a PLIF quantification methodology in a nonlinear dye response regime

NASA Astrophysics Data System (ADS)

Baj, P.; Bruce, P. J. K.; Buxton, O. R. H.

2016-06-01

A new technique of planar laser-induced fluorescence calibration is presented in this work. It accounts for a nonlinear dye response at high concentrations, an illumination light attenuation and a secondary fluorescence's influence in particular. An analytical approximation of a generic solution of the Beer-Lambert law is provided and utilized for effective concentration evaluation. These features make the technique particularly well suited for high concentration measurements, or those with a large range of concentration values, c, present (i.e. a high dynamic range of c). The method is applied to data gathered in a water flume experiment where a stream of a fluorescent dye (rhodamine 6G) was released into a grid-generated turbulent flow. Based on these results, it is shown that the illumination attenuation and the secondary fluorescence introduce a significant error into the data quantification (up to 15 and 80 %, respectively, for the case considered in this work) unless properly accounted for.

Transfer factor of 226Ra, 232Th and 40K from soil to Alpinia Galangal plant grown in northern Thailand

NASA Astrophysics Data System (ADS)

Kritsananuwat, R.; Chanyotha, S.; Kranrod, C.; Pengvanich, P.

2017-06-01

This paper reports the activity concentration of three natural radionuclides, 226Ra, 232Th and 40K, found in Alpinia Galangal plants which are widely used in various Asian cuisines and traditional medicine. The galangal plants and their relevant soils were collected from four provinces in the north of Thailand under natural field conditions. The activity concentration of radionuclides was determined using gamma-ray spectrometry. Soil-to-plant transfer factors (TFs) for 226Ra, 232Th and 40K were investigated in rhizome and aerial parts of the galangal plants. The activity concentration in the soils ranged from 22 to 88 Bq kg-1 for 226Ra, 27 to 157 Bq kg-1 for 232Th and 58 to 1157 Bq kg-1 for 40K. In Alpinia Galangal, the concentration ranged from < 0.2 to 2.0 Bq kg-1 for 226Ra, < 0.1 to 2.9 Bq kg-1 for 232Th and 205 to 2247 Bq kg-1 for 40K. The TF ranged from < 0.002 to 0.073 for 226Ra, < 0.001 to 0.061 for 232Th and 0.26 to 7.9 for 40K. The TFs in the aerial parts were higher than those for the rhizomes. The obtained values can be considered as a baseline data for activity concentrations of natural radionuclides and their TFs in Thailand for future environmental radiation monitoring. The Annual effective ingestion dose due to ingestion of 226Ra, 232Th and 40K in galangals is significantly below the worldwide value reported by UNSCEAR 2000.

Calculation Package: Derivation of Facility-Specific Derived Air Concentration (DAC) Values in Support of Spallation Neutron Source Operations

DOE Office of Scientific and Technical Information (OSTI.GOV)

McLaughlin, David A

Derived air concentration (DAC) values for 175 radionuclides* produced at the Oak Ridge National Laboratory (ORNL) Spallation Neutron Source (SNS), but not listed in Appendix A of 10 CFR 835 (01/01/2009 version), are presented. The proposed DAC values, ranging between 1 E-07 {micro}Ci/mL and 2 E-03 {micro}Ci/mL, were calculated in accordance with the recommendations of the International Commission on Radiological Protection (ICRP), and are intended to support an exemption request seeking regulatory relief from the 10 CFR 835, Appendix A, requirement to apply restrictive DACs of 2E-13 {micro}Ci/mL and 4E-11 {micro}Ci/mL and for non-listed alpha and non-alpha-emitting radionuclides, respectively.

Norcocaine in human hair as a biomarker of heavy cocaine use in a high risk population.

PubMed

Poon, S; Gareri, J; Walasek, P; Koren, G

2014-08-01

In hair analysis, cocaine (COC) and its metabolites have been studied relatively extensively with a consistent focus of distinguishing active drug use and excluding external contamination. Although quantitative cut-offs using major metabolite, benzolecgonine (BE), in hair have been proposed to distinguish likely active use from passive exposure, exogenously formed BE may result in false positive tests. Hence, the presence of less commonly detected COC metabolite, norcocaine (NCOC), may be useful in increasing certainty of illicit COC use and evaluating likelihood of environmental contamination. The objective of the present study was to observe the pattern of NCOC detection in a clinical population of suspected users and evaluate the possible role of NCOC in distinguishing systemic exposure from external contamination to COC and assessing intensity of cocaine use. Hair samples collected between January 2011 and May 2013 from the Motherisk Laboratory were analyzed by GC-MS for the presence of COC, BE, and NCOC. NCOC positivity rates (%) for various COC concentration ranges as well as sensitivity, specificity, positive predictive value, and negative predictive values of NCOC as a biomarker of different COC use profiles was calculated. The rate of NCOC positivity (%) within COC concentration ranges (ng/mg) 0.13-0.4 (above LOD, below LOQ), 0.4-3, 3-6, 6-10, 10-14, >14 were 0.26, 4.15, 29.63, 55.85, 80.37, and 94.02, respectively; p<0.0001 for all positivity comparisons between ranges. These results were used to determine a COC cut-off concentration for differing levels of COC use. The presence of NCOC above the LOD of 0.13 ng/mg predicted COC concentrations exceeding 14.00 ng/mg, with sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 94.0%, 87.9%, 41.5%, and 99.4%, respectively. The presence NCOC above the LOD of 0.13 ng/mg predicted COC concentrations exceeding the 75th percentile, with sensitivity, specificity, PPV, and NPV of 76.6%, 94.7%, 74.7%, and 95.2%, respectively. Despite an inability to definitively rule out external contamination, the presence of NCOC in hair is strongly associated with elevated COC levels and performs as a highly specific surrogate marker for frequent/intensive cocaine use and highly sensitive marker for intensive/daily use of cocaine. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Use of real-time sensors to characterise human exposures to combustion related pollutants.

PubMed

Delgado-Saborit, Juana Maria

2012-07-01

Concentrations of black carbon and nitrogen dioxide have been collected concurrently using a MicrAeth AE-51 and an Aeroqual GSS NO(2) sensor. Forty five sampling events with a duration spanning between 16 and 22 hours have collected 10,800 5 min data in Birmingham (UK) from July to October 2011. The high temporal resolution database allowed identification of peak exposures and which activities contributed the most to these peaks, such as cooking and commuting. Personal exposure concentrations for non-occupationally exposed subjects ranged between 0.01 and 50 μg m(-3) for BC with average values of 1.3 ± 2.2 μg m(-3) (AM ± SD). Nitrogen dioxide exposure concentrations were in the range

Surface tension of binary mixtures of water + N-methyldiethanolamine and ternary mixtures of this amine and water with monoethanolamine, diethanolamine, and 2-amino-2-methyl-1-propanol from 25 to 50 C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alvarez, E.; Rendo, R.; Sanjurjo, B.

1998-11-01

The surface tension of aqueous solutions of N-methyldiethanolamine and diethanolamine + N-methyldiethanolamine, monoethanolamine + N-methyldiethanolamine and 2-amino-2-methyl-1-propanol + N-methyldiethanolamine was measured at temperatures from 25 C to 50 C. For binary mixtures the concentration range was 0--50 mass % N-methyldiethanolamine, and for the tertiary mixtures the concentration range for each amine was 0--50 mass %. The experimental values were correlated with temperature and mole fraction. The maximum deviation in both cases was always less than 0.5%.

Kinetics of Mixed Microbial Assemblages Enhance Removal of Highly Dilute Organic Substrates

PubMed Central

Lewis, David L.; Hodson, Robert E.; Hwang, Huey-Min

1988-01-01

Our experiments with selected organic substrates reveal that the rate-limiting process governing microbial degradation rates changes with substrate concentration, S, in such a manner that substrate removal is enhanced at lower values of S. This enhancement is the result of the dominance of very efficient systems for substrate removal at low substrate concentrations. The variability of dominant kinetic parameters over a range of S causes the kinetics of complex assemblages to be profoundly dissimilar to those of systems possessing a single set of kinetic parameters; these findings necessitate taking a new approach to predicting substrate removal rates over wide ranges of S. PMID:16347715

Background hydrologic information in potential lignite mining areas in north-central Mississippi, August 1984

USGS Publications Warehouse

Kalkhoff, S.J.

1985-01-01

The U.S. Geological Survey, in cooperation with the Mississippi Department of Natural Resources, Bureau of Geology, is conducting a hydrologic data collection program in potential lignite-producing areas in Mississippi. During the last two weeks of August 1984, hydrologic data were collected at 15 stream sites that drain potential lignite mining areas in Lafayette, Calhoun, and Yalobusha Counties. Main channel widths ranged from approximately 60 feet at three streams (Coon Creek near Toccopula, Muckaloon Creek near Tula, and Hurricane Creek near Velma) to approximately 120 feet at two streams (Potlockney Creek near Tula, and Savannah Creek near Bruce). Maximum water depths ranged from less than 1.0 foot at most streams to over 5.0 feet at sites on Potlockney Creek near Tula and McGill Creek near Sarepta. Stream discharge ranged from 0.32 cubic feet per second in Persimmon Creek near Bruce to 18.5 cubic feet per second in Puskus Creek near Etta. The specific conductance of stream water ranged from 25 to 160 microsiemens and dissolved solids concentrations ranged from 22 to 91 mg/L (milligrams per liter). Most major ion concentrations were less than 10 mg/L with the exception of calcium (11 mg/L), sodium (12 mg/L) and sulfate (18 mg/L) in the water of Persimmon Creek near Bruce. Dissolved oxygen concentrations were greater than 5.0 mg/L at all but one site. Turbidity values were generally less than 50 units. Nitrate plus nitrite concentrations were equal to or less than 0.10 mg/L in all streams except in Potlockney Creek near Tula where the concentration was 0.11 mg/L. Copper and selenium concentrations in the water at all sampling sites ranged from below the detection limits (1 microgram/g) to 4 micrograms/g (micrograms per gram) and mercury concentrations in bottom material samples ranged from less than 0.01 microgram/g to 0.15 microgram/g. (USGS)

Anti-Muellerian hormone concentration in bitches with histopathologically diagnosed ovarian tumours and cysts.

PubMed

Walter, B; Coelfen, A; Jäger, K; Reese, S; Meyer-Lindenberg, A; Aupperle-Lellbach, H

2018-06-01

Increased concentrations of Anti-Muellerian hormone (AMH) can indicate a granulosa cell tumour as shown in women, mares and cows. To investigate AMH to differentiate canine granulosa cell tumour from other ovarian pathologies, we evaluated the ovaries of 63 bitches. Blood serum samples were collected before surgery for AMH analysis. Ovaries were submitted for histopathological examination. Fourteen bitches showed normal ovaries. These bitches had AMH values between 0.12 and 0.99 ng/ml. In 20 bitches ovarian cysts i.e., follicular cysts (n = 8), corpora lutea cysts (n = 7), subsurface cysts (n = 5) were diagnosed. These dogs had AMH values of 0.11-2.09 ng/ml. Bitches with small luteinized follicular cysts had slightly higher AMH values than those without ovarian alteration. In 29 cases ovarian neoplasms i.e., granulosa cell tumour (n = 9), epithelial tumours (n = 16), dysgerminomas (n = 3) and one sarcoma were identified. Anti-Muellerian hormone values of bitches with an ovarian neoplasm except granulosa cell tumour ranged from 0.18 to 1.18 ng/ml. The AMH values of bitches with granulosa cell tumour ranged from 1.12 to ≤23 ng/ml and were significantly higher (p < .05) than in all of the other bitches. The cut-off of 0.99 ng/ml gave a sensitivity of 100% and a specificity of 94.44% to diagnose granulosa cell tumour. In conclusion, markedly elevated AMH concentrations in bitches are indicative for a granulosa cell tumour. However, negative testing does not rule out the existence of small one. Differentiation of GCT from luteinized follicular cysts may especially be difficult. © 2018 Blackwell Verlag GmbH.

Assessment of natural radioactivity and radiological hazards in building materials used in Yan'an, China.

PubMed

Lu, Xinwei; Li, Nan; Yang, Guang; Zhao, Caifeng

2013-03-01

The concentration of natural radionuclides in commonly used building materials collected from Yan'an, China, was determined using gamma ray spectroscopy with a NaI(Tl) detector. The activity concentration of ²²⁶Ra, ²³²Th, and ⁴⁰K in the studied building materials ranges from 9.4-73.1, 11.5-86.9, and 258.9-1,055.1 Bq kg⁻¹, respectively. The concentrations for these natural radionuclides were compared with the reported data of other countries and the world mean values for soil. The radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin), indoor air absorbed dose rate, and annual effective dose rate due to natural radionuclides in samples were estimated to assess radiological hazards for people living in dwellings made of the studied building materials. The calculated Raeq values of all building materials (75.7-222.1 Bq kg⁻¹) are lower than the limit of 370 Bq kg⁻¹. The values of Hex and Hin are less than unity. The mean values of indoor air absorbed dose rates of all building materials (101.0 ± 14.1-177.0 ± 6.8 nGy h⁻¹) are higher than the world population-weighted average of 84 nGy h⁻¹, while the mean values of annual effective dose range from 0.50 ± 0.07-0.87 ± 0.03 mSv y⁻¹, which are lower than the recommended limit of 1 mSv y⁻¹. It is found that these materials may be used safely as construction materials and do not pose significant radiation hazards to inhabitants.

The effect of changing seawater Ca and Mg concentrations upon the distribution coefficients of Mg and Sr in the skeletons of the scleractinian coral Pocillopora damicornis

NASA Astrophysics Data System (ADS)

Giri, Sharmila J.; Swart, Peter K.; Devlin, Quinn B.

2018-02-01

The skeletal composition of calcifying organisms, in particular Mg/Ca and Sr/Ca ratios, have been widely used to understand fluctuations in seawater chemistry throughout the Phanerozoic. While the success of applying these data to the geologic record depends on a knowledge of the distribution coefficients for these elements (DMg and DSr), there are scarcely any studies which have described how these values vary as a result of changing seawater Mg/Ca ratios. To address this, we have cultured the scleractinian coral, Pocillopora damicornis, in seawater with ranges of Mg and Ca concentrations. Here, we demonstrate that Mg/Ca and Sr/Ca ratios of coral skeletons correlate with total seawater Mg/Ca and Sr/Ca molar ratios, but that apparent DMg and DSr values do not remain constant across the range of experimental seawater treatments, with DMg values significantly increasing with seawater Mg/Ca ratios and DSr values significantly increasing with seawater Ca concentrations. These trends are not rate dependent and may be best explained by a Rayleigh distillation model, in which the calcifying space is semi-isolated from seawater during skeletogenesis (i.e. leaky). As there is a slight increase in DMg and decrease in DSr values between our "Jurassic" and "Modern" seawater treatments, the application of a constant distribution coefficient to estimate changes in ancient seawater chemistry may underestimate seawater Mg/Ca ratios and overestimate Sr/Ca throughout the Mesozoic and Cenozoic. We suggest that interpretations of seawater chemistry from fossil corals may be improved by using the relationships derived for skeletal and seawater Mg/Ca and Sr/Ca ratios established by our experiments, as they incorporate the effect of seawater Mg/Ca ratios on skeletal Mg/Ca and Sr/Ca ratios.

Medically-derived I-131: a potential tool for understanding the fate of wastewater nitrogen in aquatic systems

NASA Astrophysics Data System (ADS)

Rose, P. S.; Smith, J. P.; Aller, R. C.; Cochran, J. K.; Swanson, R. L.; Murthy, S. N.; Coffin, R. B.

2010-12-01

Iodine-131(t1/2 = 8 days) has been measured in Potomac River water and sediments in the vicinity of the Blue Plains Water Pollution Control Plant (WPCP), Washington, DC. The source of I-131 is medical, where it is commonly used to treat thyroid cancer and hyperthyroidism. Iodine is metabolized by patients and eliminated primarily in urine. While other medical radioisotopes may enter the environment via sewage effluent, the nature and quantity of treatments using I-131 cause it to account for much of the radioactivity in sewage effluent. Natural iodine in aquatic systems is biologically cycled similar to other nutrients, such as nitrogen. Iodine-131 concentrations measured in sewage effluent from Blue Plains WPCP and in the Potomac River suggest a relatively continuous discharge of this isotope. Dissolved I-131 shows a strong, positive correlation with δ15N values of nitrate in the river. The range of I-131 concentrations detected in surface waters is 0.18 ± 0.01 to 0.68 ± 0.02 Bq/L. Surface water δ15NO3 values ranged from 8.7 ± 0.3 to 33.4 ± 7.3 ‰ with NO3+NO2 concentrations between 0.38 ± 0.02 and 2.79 ± 0.13 mgN/L. Sediment profiles of particulate I-131 and δ15N indicate rapid mixing or sedimentation and in many cases remineralization of a heavy nitrogen source consistent with wastewater nitrogen. Iodine-131 concentrations in sediments ranged from 1.31 ± 0.8 to 117 ± 2 Bq/kg dry weight. Values of δ15N in sediments ranged from 4.7 ± 0.1 ‰ to 9.3 ± 0.1 ‰. We propose that I-131 coupled with δ15N can be an excellent tracer for the short-term fate of wastewater nitrogen in this system. However, the utility of I-131 as a tracer is not limited to use in the Potomac River. Other studies have documented the presence of I-131 in several aquatic systems and continuous discharges of this radioisotope in sewage effluent are likely to be widespread in urban environments.

Geohydrology and ground-water quality at selected sites in Meade County, Kentucky, 1987-88

USGS Publications Warehouse

Mull, D.S.; Alexander, A.G.; Schultz, P.E.

1989-01-01

Meade County in north-central Kentucky is about 305 sq mi in size, and is underlain by thick beds of limestone and dolomite which are the principal sources of drinking water for about 8 ,500 residents. About half the area contains mature, karst terrain with abundant sinkholes, springs, and caves. Because of this karst terrain, groundwater is susceptible to rapid changes in water quality and contamination from human sources. Thirty-seven wells and 12 springs were selected as sampling points to characterize groundwater quality in the area. Water was analyzed for major anions and cations, nitrates, trace elements, and organic compounds. Water from selected sites was also analyzed for fecal species of coliform streptococci bacteria and total coliform content. Except for fluoride and lead, the water quality was within the range expected for carbonate aquifers.The fluoride content was significantly higher in water from wells than in water from springs. Concentrations of detectable lead ranged from 10 to 50 micrograms/L and had a median value of 7.5 microg/L. Dissolved solids ranged from 100 to 2,200 mg/L and the median value was 512 mg/L. Hardness ranged from 20 to 1,100 mg/L and the median value was 290 mg/L. Organic compounds detected by the gas chromatographic/flame ionization detection scans, did not indicate evidence of concentrations in excess of the current Federal drinking water standards. Analysis for specific organic compounds indicated that the presence of these compounds was associated with agricultural chemicals, usually pesticides. Total coliform content exceeded drinking water standards in water from all 12 springs and in 18 wells. Statistical analysis of the groundwater quality data indicates that the variance of the concentrations of fluoride and chloride may be attributed to the site type. There was strong correlation between hardness and dissolved solids, hardness and sulfate, and sulfate and dissolved solids. No apparent relations were detected between water quality and the geographic location of sampling sites. However, seasonal variations were detected in the concentrations of dissolved solids, hardness, and iron. (Lantz-PTT)

From single-substance evaluation to ecological process concept: the dilemma of processing gold with cyanide.

PubMed

Korte, F; Coulston, F

1995-10-01

In the past decades, limit concentration values for environmentally dangerous synthetic and natural chemical substances have been established in industrialized countries. Depending on the range of application, state of aggregation, propagation velocity, specific action on living organisms, long- or short-time effect, etc., different terms are used to specify these limit concentrations (acceptable daily intakes, TLV, LD50, emission values, water quality standards, etc.). Several parameters (e.g., range of application, ethic and social valuation, environmental factors, scientific knowledge) have led to nationally and internationally varying values depending on the region and time. The accuracy of this system of evaluation cannot necessarily be improved by listing further analytical data, but rather by furnishing sufficiently secured scientific data for a serious discussion, with the public concepts influenced more and more by the mass media. The best-established scientific knowledge has been acquired by the chemical industry. National and international groups demand that ecological-chemical problems in other fields of industry be dealt with as well; this research should, without doubt, be intensified. The example of the mining industry, which must employ chemical methods to isolate small concentrations (ppm), demonstrates the environmental conflict caused by the increasing world population, requiring the adaptation of the process by industry to the modern environmental concept. This is illustrated by the evolution of the gold recovery process.

Methamphetamine blood concentrations in human abusers: application to pharmacokinetic modeling.

PubMed

Melega, William P; Cho, Arthur K; Harvey, Dennis; Laćan, Goran

2007-04-01

Characterization of methamphetamine's (METH) dose-dependent effects on brain neurochemistry may represent a critical component for better understanding the range of resultant behavioral pathologies. Most human studies, however, have assessed only the effects of long term, high dose METH abuse (e.g., greater than 1000 mg/day) in individuals meeting DSM-IV criteria for METH dependence. Yet, for the majority of METH abusers, their patterns of METH exposure that consist of lower doses remain less well-characterized. In this study, blood samples were obtained from 105 individuals detained by police for possible criminal activity and testing positive for stimulants by EMIT assay. METH blood concentrations were subsequently quantified by GC-MS and were predominantly in the low micromolar range (0.1-11.1 microM), with median and mean values of 1.3 microM (0.19 mg/l) and 2 microM (0.3 mg/l), respectively. Pharmacokinetic calculations based on these measured values were used to estimate initial METH body burdens, the median value being 52 mg. Modeling a 52 mg dose for a 4 day-METH maintenance exposure pattern of 4 doses/day at 4 h intervals showed that blood concentrations remained between 1 and 4 microM during this period. Collectively, these data present evidence for a METH exposure pattern distinct from high dose-METH abuse and provide the rationale for assessing potential brain pathology associated with such lower dose-METH exposure.

Specific Conductance and Dissolved-Solids Characteristics for the Green River and Muddy Creek, Wyoming, Water Years 1999-2008

USGS Publications Warehouse

Clark, Melanie L.; Davidson, Seth L.

2009-01-01

Southwestern Wyoming is an area of diverse scenery, wildlife, and natural resources that is actively undergoing energy development. The U.S. Department of the Interior's Wyoming Landscape Conservation Initiative is a long-term science-based effort to assess and enhance aquatic and terrestrial habitats at a landscape scale, while facilitating responsible energy development through local collaboration and partnerships. Water-quality monitoring has been conducted by the U.S. Geological Survey on the Green River near Green River, Wyoming, and Muddy Creek near Baggs, Wyoming. This monitoring, which is being conducted in cooperation with State and other Federal agencies and as part of the Wyoming Landscape Conservation Initiative, is in response to concerns about potentially increased dissolved solids in the Colorado River Basin as a result of energy development. Because of the need to provide real-time dissolved-solids concentrations for the Green River and Muddy Creek on the World Wide Web, the U.S. Geological Survey developed regression equations to estimate dissolved-solids concentrations on the basis of continuous specific conductance using relations between measured specific conductance and dissolved-solids concentrations. Specific conductance and dissolved-solids concentrations were less varied and generally lower for the Green River than for Muddy Creek. The median dissolved-solids concentration for the site on the Green River was 318 milligrams per liter, and the median concentration for the site on Muddy Creek was 943 milligrams per liter. Dissolved-solids concentrations ranged from 187 to 594 milligrams per liter in samples collected from the Green River during water years 1999-2008. Dissolved-solids concentrations ranged from 293 to 2,485 milligrams per liter in samples collected from Muddy Creek during water years 2006-08. The differences in dissolved-solids concentrations in samples collected from the Green River compared to samples collected from Muddy Creek reflect the different basin characteristics. Relations between specific conductance and dissolved-solids concentrations were statistically significant for the Green River (p-value less than 0.001) and Muddy Creek (p-value less than 0.001); therefore, specific conductance can be used to estimate dissolved-solids concentrations. Using continuous specific conductance values to estimate dissolved solids in real-time on the World Wide Web increases the amount and improves the timeliness of data available to water managers for assessing dissolved-solids concentrations in the Colorado River Basin.

Kinetic studies on the removal of phenol by MBBR from saline wastewater.

PubMed

Ahmadi, Mehdi; Jaafarzadeh, Neamat; Rahmat, Zeinab Ghaed; Babaei, Ali Akbar; Alavi, Nadali; Baboli, Zeinab; Niri, Mehdi Vosoughi

2017-01-01

Phenols are chemical compounds which are included in the high priority of pollutants by environmental protection agency (USEPA). The presence of high concentrations of phenols in wastewaters like oil refineries, petrochemical plants, olive oil, pesticide production and oil field operations contain high soluble solids (TDS) and in an olive oil plant, wastewater is acidic, high salty and phenol concentrations are in the range of 0.1- 1%. Kinetic parameters were calculated according to Monod, Modified Stover- Kincannon, Hamoda and Haldane models. The influence of different initial phenol concentrations on the biodegradation rate was performed. The concentrations of phenol varied from 0 to 500 mg / l. The value of K i in saline phenolic wastewater in attached growth systems was higher than suspended growth systems that represented a higher phenol inhibition in suspended growth systems. It was obvious that the best model fitting the obtained data are Hamoda model and the Modified Stover-Kincannon model, having highest R 2 values of 0.991 and 1, respectively. The value of K i in saline phenolic wastewater in attached growth system was higher than suspended growth systems which represented a higher phenol inhibition in suspended growth systems. Hamoda model and the Modified Stover-Kincannon model having highest R2 value of 0.991 and 1, respectively, and also predicting reasonable kinetic coefficient values.

Evaluation of natural and anthropogenic radioactivity in environmental samples from Kuwait using high-resolution gamma-ray spectrometry

NASA Astrophysics Data System (ADS)

Bajoga, Abubakar D.

A study of natural radioactivity from ninety different soil samples across the state of Kuwait was carried out with a view to ascertain the level of natural and/or man-made radioactivity from that area. There has been some concern on the levels of NORM following the First Gulf War in which approximately 300 tons of depleted uranium shells were used and in particular, whether it has a significant impact in the surrounding environment. This study uses gamma-spectroscopy in a low background measuring system employing a high resolution Hyper-Pure Germanium detector. The calculated specific activity concentrations are determined for the radionuclides 226Ra, 214Pb, 214Bi and 228Ac, 212Pb, 208Tl following the decays of the primordial radionuclides 238U and 232Th, respectively. The analysis also includes evaluations for the 235U decay chain. In particular, the 186 keV doublet transition is used together with the activity concentration values established from the decays of 214Bi and 214Pb to establish the 226Ra and 235U specific activity concentrations, which can be used to estimate the 235U:238U isotopic ratios and compare to the accepted value for naturally occurring material of 1:138. Specific activity concentration values have also been determined for the 40K and the anthropogenic radionuclide 137Cs (from fallout) were detected within the same samples. Results of the activity concentration gives mean value of 16.99±0.21, 12.79±0.14, 333±37 and 2.18±0.11 Bq/kg for 238U, 232Th, 40K, and 137Cs, respectively. The associated radiological hazard indices from these samples were found to have mean values of 29.13±0.35 nG/hr, 60.20±0.68 Bq/kg, and 35.30±0.40 µSv/year for the dose rates, radium equivalent, and annual dose equivalent, respectively. Analysed results of elemental concentrations of Uranium, Thorium and Potassium were also determined, and were found to range from 0.96±0.02 ppm to 2.53±0.02 ppm, 2.26±0.04 ppm to 5.23±0.05 ppm and a mean value of 1.21±0.03 % for 40K for the northern region, respectively. Overall result indicates values within the world average range. The results obtained for the 235U:238U isotopic ratio gives a mean value of 0.0462, which is consistent with the presence of natural material from the measured location.

Disinfection Byproducts in Drinking Water and Evaluation of Potential Health Risks of Long-Term Exposure in Nigeria.

PubMed

Benson, Nsikak U; Akintokun, Oyeronke A; Adedapo, Adebusayo E

2017-01-01

Levels of trihalomethanes (THMs) in drinking water from water treatment plants (WTPs) in Nigeria were studied using a gas chromatograph (GC Agilent 7890A with autosampler Agilent 7683B) equipped with electron capture detector (ECD). The mean concentrations of the trihalomethanes ranged from zero in raw water samples to 950  μ g/L in treated water samples. Average concentration values of THMs in primary and secondary disinfection samples exceeded the standard maximum contaminant levels. Results for the average THMs concentrations followed the order TCM > BDCM > DBCM > TBM. EPA-developed models were adopted for the estimation of chronic daily intakes (CDI) and excess cancer incidence through ingestion pathway. Higher average intake was observed in adults (4.52 × 10 -2  mg/kg-day), while the ingestion in children (3.99 × 10 -2  mg/kg-day) showed comparable values. The total lifetime cancer incidence rate was relatively higher in adults than children with median values 244 and 199 times the negligible risk level.

Urinary creatinine concentrations in an industrial workforce and comparison with reference values of the general population.

PubMed

Bader, Michael; Messerer, Peter; Will, Wolfgang

2013-08-01

Urinary creatinine is an important parameter for the adjustment of metabolite concentrations in differently diluted urine specimens, as a reference dimension for biological limit or guidance values and as a selection criterion for spot urine samples in human biomonitoring. While the creatinine output of the general population has been well described in environmental surveys, this study focused specifically on creatinine concentrations in a large industrial workforce in order to compare these data with the general population and to provide a database for the calculation of a reasonable conversion factor between volume-related and creatinine-adjusted data and vice versa. Urinary creatinine was analysed in 6,438 spot urine samples by a photometric assay in the time period between 1989 and 2009. Basic demographic data (age, sex, body weight, body height) and job category (apprentices, skilled craftsmen, skilled chemical workers, foremen, laboratory staff and executives) were considered in a statistical analysis. The median concentration of urinary creatinine in all urine samples was 1.36 g/L with male employees showing significantly higher values (1.37 g/L, n = 6,148 samples) than female employees (1.00 g/L, n = 290) and concentrations ranging from 0.01 up to 9.76 g/L. Age, body mass index and job category were significant influence factors on urinary creatinine. About 92 % of all samples showed creatinine concentrations between 0.3 and 3.0 g/L, a range recommended by the World Health Organization as a criterion for valid spot urine samples. The results of this study correspond well with data from environmental surveys and with recent data from an active workforce in industry with similar sampling strategies. Therefore, a median of 1.4 g creatinine per litre urine seems to be a reasonable value for general calculations and adjustments. The study data also support the validity of the current recommendations by the WHO and several scientific committees and institutions with respect to creatinine limits in spot urine samples for occupational-medical biomonitoring.

Miocene weathering environments in Western Australia-Inferences from the abundance and 13C/12C of Fe(CO3)OH in CID goethite

NASA Astrophysics Data System (ADS)

Fritz, Tyler O.; Yapp, Crayton J.

2018-04-01

The channel iron deposits (CID) of the Hamersley Province in Western Australia are dominated by pedogenic goethite/hematite-rich ooids and pisoids that were transported to, and deposited in, the meandering channels of Miocene rivers. Information about the Miocene weathering environments that produced the Fe(III) oxides is archived in the mole fraction (X) and δ13C of the Fe(CO3)OH component in solid solution in oolitic CID goethite (α-FeOOH). Values of X and δ13C were measured for 12 oolitic goethite samples from different depths in two cores drilled in CID of the Robe Formation of Mesa J. The weighted-average plateau values of X ranged from 0.0098 to 0.0334, which suggest ambient CO2 concentrations that ranged from ∼50,000 ppm V to perhaps as much as ∼200,000 ppm V at the time of goethite crystallization. In a vadose zone characterized by in situ production of CO2 with steady-state Fickian diffusive transport of the gas, such concentrations would correspond to modeled soil respiration rates (Q) ranging from about 10 to 30 mmol/m2/h. Values for Q of about 10 mmol/m2/h are reported for soils in modern tropical forests with MAP ≥ ∼2000 mm. However, model-derived values of Q that exceed 15 mmol/m2/h are larger than observed in modern systems. This could indicate that some of the CID goethites crystallized in conditions that were phreatic or near phreatic rather than vadose. The δ13C values of the Fe(CO3)OH component in these 12 CID samples ranged from -24.0‰ to -22.3‰, which are among the most negative measured to date. If they reflect steady-state diffusive transport of CO2 in vadose environments, the soil CO2 would have been derived from a source with δ13C values that ranged from ∼-31‰ to -29‰. If, on the other hand, the goethites crystallized in a nearly phreatic environment that was moderately acidic, the inferred δ13C of the ancient CO2 source would have been about -27.6‰ to -25.8‰. In either case, the δ13C values point to in situ oxidation of C3 organic matter as the predominant source of the ambient CO2. The Fe(III) oxides in the CID ooids suggest crystallization in aerobic environments. However, even in aerobic environments, many microbial species can reduce the Fe3+ in oxides to relatively soluble Fe2+ and may have facilitated progressive Fe enrichment during multiple cycles of Fe(III) oxide dissolution and recrystallization. At the same time, microbially mediated oxidation of organic matter could have produced the high concentrations of soil CO2 with the very negative δ13C values recorded in the Fe(CO3)OH component in oolitic goethite. More frequent summer storms in the Miocene, may have been a significant factor in forming and eroding these soil systems and in concentrating large volumes of oolitic Fe(III) oxides in the local river systems to form channel iron deposits. However, published (U-Th)/He ages indicate that the oolitic CID goethites of Mesa J became closed systems after ∼7 Ma, which suggests a change in local climate and/or conditions of burial at about that time in the Miocene.

Pilot study of Iopamidol-based quantitative pH imaging on a clinical 3T MR scanner.

PubMed

Müller-Lutz, Anja; Khalil, Nadia; Schmitt, Benjamin; Jellus, Vladimir; Pentang, Gael; Oeltzschner, Georg; Antoch, Gerald; Lanzman, Rotem S; Wittsack, Hans-Jörg

2014-12-01

The objective of this study was to show the feasibility to perform Iopamidol-based pH imaging via clinical 3T magnetic resonance imaging (MRI) using chemical exchange saturation transfer (CEST) imaging with pulse train presaturation. The pulse train presaturation scheme of a CEST sequence was investigated for Iopamidol-based pH measurements using a 3T magnetic resonance (MR) scanner. The CEST sequence was applied to eight tubes filled with 100-mM Iopamidol solutions with pH values ranging from 5.6 to 7.0. Calibration curves for pH quantification were determined. The dependence of pH values on the concentration of Iopamidol was investigated. An in vivo measurement was performed in one patient who had undergone a previous contrast-enhanced computed tomography (CT) scan with Iopamidol. The pH values of urine measured with CEST MRI and with a pH meter were compared. In the measured pH range, pH imaging using CEST imaging with pulse train presaturation was possible. Dependence between the pH value and the concentration of Iopamidol was not observed. In the in vivo investigation, the pH values in the human bladder measured by the Iopamidol CEST sequence and in urine were consistent. Our study shows the feasibility of using CEST imaging with Iopamidol for quantitative pH mapping in vitro and in vivo on a 3T MR scanner.

Cure of tuberculosis despite serum concentrations of antituberculosis drugs below published reference ranges.

PubMed

Meloni, Monica; Corti, Natascia; Müller, Daniel; Henning, Lars; Gutteck, Ursula; von Braun, Amrei; Weber, Rainer; Fehr, Jan

2015-01-01

Therapeutic target serum concentrations of first-line antituberculosis drugs have not been well defined in clinical studies in tuberculosis (TB) patients. We retrospectively investigated the estimated maximum serum concentrations (eC max) of antituberculosis drugs and clinical outcome of TB patients with therapeutic drug monitoring performed between 2010-2012 at our institution, and follow-up until March 2014. The eC max was defined as the highest serum concentration during a sampling period (2, 4 and 6 hours after drug ingestion). We compared the results with published eC max values, and categorised them as either "within reference range", "low eC max", or "very low eC max".Low/very low eC max-levels were defined as follows: isoniazid 2-3/<2 mg/l, rifampicin 4-8/<4 mg/l, rifabutin 0.2-0.3/<0.2 mg/l, ethambutol 1-2/<0.1 mg/l and pyrazinamide <20 mg/l. Concentrations of antituberculosis drugs in 175 serum samples of 17 patients with TB were analysed. In 12 (71%) patients, multiple therapeutic drug monitoring samples were collected over time, in 5 (29%) patients only one sample was available for therapeutic drug monitoring. Overall, 94% of all patients had at least one low antituberculosis drug concentration. Overall, 64% of all eC max levels were classified as "low" or "very low". The eC max was below the relevant reference range in 80% of isoniazid, 95% of rifampicin, 30% of pyrazinamide, and 30% of ethambutol measurements. All but one patient were cured of tuberculosis. Although many antituberculosis drug serum concentrations were below the widely used reference ranges, 16 of 17 patients were cured of tuberculosis. These results challenge the use of the published reference ranges for therapeutic drug monitoring.

Hemostatic variables, plasma lactate concentration, and inflammatory biomarkers in dogs with gastric dilatation-volvulus.

PubMed

Verschoof, J; Moritz, A; Kramer, M; Bauer, N

2015-01-01

Prospective characterization of hemostastatic variables, plasma lactate concentration, and inflammatory biomarkers in dogs with gastric dilatation-volvulus (GDV). Coagulation variables (platelets, prothrombin time [PT], activated partial thromboplastin time [aPTT], fibrinogen, antithrombin [AT], protein C [PC], protein S [PS], D-dimers), plasma lactate concentration and inflammatory biomarkers (C-reactive protein, white blood cell [WBC] count, lymphocyte and neutrophil numbers) were assessed in 20 dogs with GDV presented between 2011 and 2012. Blood was taken preoperatively and at days 1 and 3 postoperatively. The prognostic value of these variables before and after surgery was evaluated as well as the behavior of variables during the study. Overall, 7/20 (35%) dogs did not survive; two dogs (29%) were euthanized during surgery due to severe gastric necrosis and 5 (71%) dogs after surgery due to sepsis and disseminated intravascular coagulopathy. Prior to surgery, median plasma lactate concentration was significantly (p = 0.01) lower in survivors (6.2 mmol/l, range 1.9-9.7 mmol/l) when compared to non-survivors (11.8 mmol/l, range 7.5-16.2 mmol/l). In dogs dying after surgery, significantly higher plasma lactate concentration, coagulation times and D-dimer concentration were present as well as lower fibrinogen concentration and activity of PC and AT compared to survivors. At discharge, activity of AT, PC and PS were markedly below the reference interval in 6/13 (46%), 11/13 (85%), and 8/13 (62%) dogs, respectively. Only lactate plasma concentration was of preoperative prognostic value. After surgery, severe abnormalities of coagulation variables, especially the endogenous anticoagulants were present in most of the dogs. The severity of the abnormalities was associated with survival.

Effect of europium ion concentration on the structural and photoluminescence properties of novel Li2BaZrO4: Eu3+ nanocrystals

NASA Astrophysics Data System (ADS)

Ahemen, I.; Dejene, F. B.; Kroon, R. E.; Swart, H. C.

2017-12-01

This work reports the influence of Eu3+ ion concentration on the structure and photoluminescence properties of Li2BaZrO4 nanocrystals including its intrinsic quantum efficiency (IQE). Chemical bath method was employed in the synthesis procedure. X-ray diffraction results showed tetragonal phase for Eu3+ ion concentration in the range 1 and 7 mol% and cubic phase at 8 mol%. The presence of barium oxide (BaO) was confirmed from selected area electron diffraction (SAED). The excitation spectra for these phosphors consisted of broad charge transfer (CT) bands due to the combination of Zr4+ - O2- and Eu3+-O2- charge transfer states. Superimposed on the CT band were direct excitation levels of Eu3+ and Ba2+ ions, in the range 320-450 nm. At high Eu3+ ions concentrations, the intensities of CT bands decreased because some of the ions were coordinated with Ba2+ ions. Photoluminescence emissions for all the doped samples at room temperature appeared to be entirely from intraconfigurational Eu3+ emissions and depended both on the site symmetry as well as the ion concentration. The quadrupole-quadrupole multipolar process was found to be solely responsible for the luminescence quenching. The intensity parameters (Ω2 ,Ω4), asymmetry ratio, R0 and the average decay lifetime of the nanocrystals showed dependence on concentration. High internal quantum efficiency (IQE) values were obtained at low Eu3+ ion concentrations, but efficiency decreased with increasing ion concentration. The CIE coordinates values were comparable to existing red phosphors and in combination with the high IQE make this phosphor a good candidate for red light emitting applications.

Modeling particle number concentrations along Interstate 10 in El Paso, Texas

PubMed Central

Olvera, Hector A.; Jimenez, Omar; Provencio-Vasquez, Elias

2014-01-01

Annual average daily particle number concentrations around a highway were estimated with an atmospheric dispersion model and a land use regression model. The dispersion model was used to estimate particle concentrations along Interstate 10 at 98 locations within El Paso, Texas. This model employed annual averaged wind speed and annual average daily traffic counts as inputs. A land use regression model with vehicle kilometers traveled as the predictor variable was used to estimate local background concentrations away from the highway to adjust the near-highway concentration estimates. Estimated particle number concentrations ranged between 9.8 × 103 particles/cc and 1.3 × 105 particles/cc, and averaged 2.5 × 104 particles/cc (SE 421.0). Estimates were compared against values measured at seven sites located along I10 throughout the region. The average fractional error was 6% and ranged between -1% and -13% across sites. The largest bias of -13% was observed at a semi-rural site where traffic was lowest. The average bias amongst urban sites was 5%. The accuracy of the estimates depended primarily on the emission factor and the adjustment to local background conditions. An emission factor of 1.63 × 1014 particles/veh-km was based on a value proposed in the literature and adjusted with local measurements. The integration of the two modeling techniques ensured that the particle number concentrations estimates captured the impact of traffic along both the highway and arterial roadways. The performance and economical aspects of the two modeling techniques used in this study shows that producing particle concentration surfaces along major roadways would be feasible in urban regions where traffic and meteorological data are readily available. PMID:25313294

Nitrobenzodiazepines: Postmortem brain and blood reference concentrations.

PubMed

Skov, Louise; Holm, Karen Marie Dollerup; Linnet, Kristian

2016-11-01

Reference concentrations are needed to evaluate postmortem toxicology results and usually femoral blood is the specimen of choice. However, brain tissue has been suggested as a viable alternative specimen, since postmortem blood concentrations can be difficult to interpret due to postmortem redistribution, among other factors. Here we present reference concentrations of postmortem brain and femoral blood of the nitrobenzodiazepines clonazepam, flunitrazepam, and nitrazepam that are of particular interest since they commonly are converted to their corresponding 7-aminometabolites in the postmortem situation. The drugs and metabolites were quantified in both matrices using LC-MS-MS in 69 cases. In 63 cases the compounds were judged not to have been of significance for the death (C cases), whereas they were considered to have been a contributing factor in 6 cases (B cases). No cases were observed with a nitrobenzodiazepine being the sole cause of death (A cases). The brain-blood ratios for clonazepam and nitrazepam were 5.5 and 4.7, respectively, while the brain-blood ratios for the 7-aminometabolites ranged from 0.4 to 0.5. Flunitrazepam only occurred as the 7-aminometabolite. A positive correlation between brain and blood concentrations was found with Spearman's rank correlation coefficients (r s ) ranging from 0.77 to 0.96. The measured femoral blood concentrations agree with literature values, but only few brain concentrations were available for comparison. The drug-metabolite ratios for clonazepam and nitrazepam were 10-12 times higher in brain than in blood. The pre-analytical variation in brain of 5.9% was fairly low, suggesting that brain tissue is a useful alternative to blood. The reported brain and femoral blood concentrations serve as reference values in postmortem investigations. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A geographical approach to tracking Escherichia coli and other water quality constituents in a Texas coastal plains watershed.

PubMed

Harclerode, C L; Gentry, T J; Aitkenhead-Peterson, J A

2013-06-01

Diffuse sources of surface water pathogens and nutrients can be difficult to isolate in larger river basins. This study used a geographical or nested approach to isolate diffuse sources of Escherichia coli and other water quality constituents in a 145.7-km(2) river basin in south central Texas, USA. Average numbers of E. coli ranged from 49 to 64,000 colony forming units (CFU) per 100 mL depending upon season and stream flow over the 1-year sampling period. Nitrate-N concentrations ranged from 48 to 14,041 μg L(-1) and orthophosphate-P from 27 to 2,721 μg L(-1). High concentrations of nitrate-N, dissolved organic nitrogen, and orthophosphate-P were observed downstream of waste water treatment plants but E. coli values were higher in a watershed draining an older part of the city. Total urban land use explained between 56 and 72 % of the variance in mean annual E. coli values (p < 0.05) in nine hydrologically disconnected creeks. Of the types of urban land use, commercial land use explained most of the variance in E. coli values in the fall and winter. Surface water sodium, alkalinity, and potassium concentrations in surface water were best described by the proportion of commercial land use in the watershed. Based on our nested approach in examining surface water, city officials are able to direct funding to specific areas of the basin in order to mitigate high surface water E. coli numbers and nutrient concentrations.

Probing resistivity and doping concentration of semiconductors at the nanoscale using scanning microwave microscopy

NASA Astrophysics Data System (ADS)

Brinciotti, Enrico; Gramse, Georg; Hommel, Soeren; Schweinboeck, Thomas; Altes, Andreas; Fenner, Matthias A.; Smoliner, Juergen; Kasper, Manuel; Badino, Giorgio; Tuca, Silviu-Sorin; Kienberger, Ferry

2015-08-01

We present a new method to extract resistivity and doping concentration of semiconductor materials from Scanning Microwave Microscopy (SMM) S11 reflection measurements. Using a three error parameters de-embedding workflow, the S11 raw data are converted into calibrated capacitance and resistance images where no calibration sample is required. The SMM capacitance and resistance values were measured at 18 GHz and ranged from 0 to 100 aF and from 0 to 1 MΩ, respectively. A tip-sample analytical model that includes tip radius, microwave penetration skin depth, and semiconductor depletion layer width has been applied to extract resistivity and doping concentration from the calibrated SMM resistance. The method has been tested on two doped silicon samples and in both cases the resistivity and doping concentration are in quantitative agreement with the data-sheet values over a range of 10-3 Ω cm to 101 Ω cm, and 1014 atoms per cm3 to 1020 atoms per cm3, respectively. The measured dopant density values, with related uncertainties, are [1.1 +/- 0.6] × 1018 atoms per cm3, [2.2 +/- 0.4] × 1017 atoms per cm3, [4.5 +/- 0.2] × 1016 atoms per cm3, [4.5 +/- 1.3] × 1015 atoms per cm3, [4.5 +/- 1.7] × 1014 atoms per cm3. The method does not require sample treatment like cleavage and cross-sectioning, and high contact imaging forces are not necessary, thus it is easily applicable to various semiconductor and materials science investigations.

Pesticides and nitrate in groundwater underlying citrus croplands, Lake Wales Ridge, central Florida, 1999-2005.

USGS Publications Warehouse

Choquette, Anne F.

2014-01-01

This report summarizes pesticide and nitrate (as nitrogen) results from quarterly sampling of 31 surficial-aquifer wells in the Lake Wales Ridge Monitoring Network during April 1999 through January 2005. The wells, located adjacent to citrus orchards and used for monitoring only, were generally screened (sampled) within 5 to 40 feet of the water table. Of the 44 citrus pesticides and pesticide degradates analyzed, 17 were detected in groundwater samples. Parent pesticides and degradates detected in quarterly groundwater samples, ordered by frequency of detection, included norflurazon, demethyl norflurazon, simazine, diuron, bromacil, aldicarb sulfone, aldicarb sulfoxide, deisopropylatrazine (DIA), imidacloprid, metalaxyl, thiazopyr monoacid, oxamyl, and aldicarb. Reconnaissance sampling of five Network wells yielded detection of four additional pesticide degradates (hydroxysimazine, didealkylatrazine, deisopropylhydroxyatrazine, and hydroxyatrazine). The highest median concentration values per well, based on samples collected during the 1999–2005 period (n=14 to 24 samples per well), included 3.05 µg/L (micrograms per liter) (simazine), 3.90 µg/L (diuron), 6.30 µg/L (aldicarb sulfone), 6.85 µg/L (aldicarb sulfoxide), 22.0 µg/L (demethyl norflurazon), 25.0 µg/ (norflurazon), 89 µg/ (bromacil), and 25.5 mg/L (milligrams per liter) (nitrate). Nitrate concentrations exceeded the 10 mg/L (as nitrogen) drinking water standard in one or more groundwater samples from 28 of the wells, and the median nitrate concentration among these wells was 14 mg/L. Sampled groundwater pesticide concentrations exceeded Florida’s health-guidance benchmarks for aldicarb sulfoxide and aldicarb sulfone (4 wells), the sum of aldicarb and its degradates (6 wells), simazine (2 wells), the sum of simazine and DIA (3 wells), diuron (2 wells), bromacil (1 well), and the sum of norflurazon and demethyl norflurazon (1 well). The magnitude of fluctuations in groundwater pesticide concentrations varied between wells and between pesticide compounds. Of the 10 pesticide compounds detected at sufficient frequency to assess temporal variability in quarterly sampling records, median values of the relative interquartile range (ratio of the interquartile range to the median) among wells typically ranged from about 100 to 150 percent. The relative interquartile range of pesticide concentrations at individual wells could be much higher, sometimes exceeding 200 to 500 percent. No distinct spatial patterns were apparent among median pesticide concentrations in sampled wells; nitrate concentrations tended to be greater in samples from wells in the northern part of the study area.

An overview of the PM10 pollution problem, in the Metropolitan Area of Athens, Greece. Assessment of controlling factors and potential impact of long range transport.

PubMed

Grivas, G; Chaloulakou, A; Kassomenos, P

2008-01-15

The present study analyzes PM(10) concentration data collected by the Greek air quality monitoring network at 8 sites over the Greater Athens Area, for the period of 2001-2004. The primary objectives were to assess the degree of compliance with the EU-legislated air quality standard for PM(10) and also provide an overall statistical examination of the factors controlling the seasonal and spatial variation of concentrations, over the wider urban agglomeration. Daily concentrations, averaged over the whole study period, ranged between 32.3 and 60.9 microg m(-3). The four-year average concentration of PM(10) at five sites exceeded the annual limit value of 40 microg m(-3), while most of the sites surpassed the allowed percentage of exceedances of the daily limit value (50 microg m(-3)), for each of the four years. The seasonal variation of PM(10) levels was not found to be uniform across the eight sites, with average cold-period concentrations being higher at four of them and warm period concentrations being significantly higher at three sites, which also displayed recurring annual variation of monthly concentrations. Concentration levels displayed moderate spatial heterogeneity. Nevertheless significant inter-site correlations were observed (ranging between 0.55 and 085). The determination of the spatial correlation levels relied mainly on site types rather than on inter-site distances. Monitoring sites were classified accordingly using cluster analysis in two groups presenting distinct spatiotemporal variation and affected by different particle formation processes. The group including urban sites was mainly affected by primary, combustion-related processes and especially vehicular traffic, as it was also deduced through the examination of the diurnal distribution of particulate levels and through factor analysis. On the contrary, suburban background sites seemed more affected by particle transport from more polluted neighboring areas and secondary particle formation through gaseous precursors, both processes aided from favoring meteorological conditions. The association of the PM(10) levels with backwards trajectories was also examined, in an attempt to account for the possible long range transport of particles in Athens. It was found that a notable part of area-wide episodic events could be attributed to trans-boundary transport of particles, with the origins of some severe dust outbreaks traced back to the Sahara desert and the Western Mediterranean.

Degradation in soil and water and ecotoxicity of rimsulfuron and its metabolites.

PubMed

Martins, J M; Chevre, N; Spack, L; Tarradellas, J; Mermoud, A

2001-11-01

The degradation and ecotoxicity of sulfonylurea herbicide rimsulfuron and its major metabolites were examined in batch samples of an alluvial sandy loam and in freshwater. An HPLC-DAD method was adapted to simultaneously identify and quantify rimsulfuron and its metabolites, which was successfully validated by GC-MS analysis. In aqueous solutions, pure rimsulfuron was rapidly hydrolyzed into metabolite 1 (N-(4,6-dimethoxypyrimidin-2-yl)-N-(3-(ethylsulfonyl)-2-pyridinylurea)), which itself was transformed into the more stable metabolite 2 (N-((3-(ethylsulfonyl)-2-pyridinyl)-4,6-dimethoxy-2-pyrimidineamine)), with half-life (t(1/2)) values of 2 and 2.5 days, respectively. Hydrolysis was instantaneous under alkaline conditions (pH = 10). In aqueous suspensions of the alluvial soil (pH = 8), formulated rimsulfuron had a half-life of 7 days, whereas that of metabolite 1 was similar to that in water (about 3.5 days). The degradation of the two major metabolites was also studied in soil suspensions with the pure compounds at concentrations ranging from 1 to 10 mg l(-1). The half-life of metabolite 1 ranged from 3.9 to 5 days, close to the previous values. Metabolite 2 was more persistent and its degradation is strongly dependent on the initial concentration (C0): half-life values ranged from 8.1 to 55 days at 2-10 mg l(-1), respectively. These values are higher than those determined from the kinetics of metabolite 1 transformation into metabolite 2 (t(1/2) = 8-19 days). The ecotoxicity of the three chemicals was evaluated through their effect on Daphnia magna and Vibrio fischeri (Microtox bioassay). No effect was observed on D. magna with 24 and 48 h acute toxicity tests. Similarly, no toxic effect was observed with the Microtox test for the three chemicals in the range of concentrations tested that included the field application dose. Thus, being of low persistence and lacking acute toxicity, these chemicals present a low environmental risk. However, chronic effects should be studied in order to confirm the safety of rimsulfuron and its major metabolites.

A climatology of ⁷Be in surface air in European Union.

PubMed

Hernández-Ceballos, M A; Cinelli, G; Ferrer, M Marín; Tollefsen, T; De Felice, L; Nweke, E; Tognoli, P V; Vanzo, S; De Cort, M

2015-03-01

This study presents a European-wide analysis of the spatial and temporal distribution of the cosmogenic isotope (7)Be in surface air. This is the first time that a long term database of 34 sampling sites that regularly provide data to the Radioactivity Environmental Monitoring (REM) network, managed by the Joint Research Centre (JRC) in Ispra, is used. While temporal coverage varies between stations, some of them have delivered data more or less continuously from 1984 to 2011. The station locations were considerably heterogeneous, both in terms of latitude and altitude, a range which should ensure a high degree of representativeness of the results. The mean values of (7)Be activity concentration presented a spatial distribution value ranging from 2.0 to 5.4 mBq/m(3) over the European Union. The results of the ANOVA analysis of all (7)Be data available indicated that its temporal and spatial distributions were mainly explained by the location and characteristic of the sampling sites rather than its temporal distribution (yearly, seasonal and monthly). Higher (7)Be concentrations were registered at the middle, compared to high-latitude, regions. However, there was no correlation with altitude, since all stations are sited within the atmospheric boundary layer. In addition, the total and yearly analyses of the data indicated a dynamic range of (7)Be activity for each solar cycle and phase (maximum or minimum), different impact on stations having been observed according to their location. Finally, the results indicated a significant seasonal and monthly variation for (7)Be activity concentration across the European Union, with maximum concentrations occurring in the summer and minimum in the winter, although with differences in the values reached. The knowledge of the horizontal and vertical distribution of this natural radionuclide in the atmosphere is a key parameter for modelling studies of atmospheric processes, which are important phenomena to be taken into account in the case of a nuclear accident. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Characteristics of dimethylaminium and trimethylaminium in atmospheric particles ranging from supermicron to nanometer sizes over eutrophic marginal seas of China and oligotrophic open oceans.

PubMed

Yu, Peiran; Hu, Qingjing; Li, Kai; Zhu, Yujiao; Liu, Xiaohuan; Gao, Huiwang; Yao, Xiaohong

2016-12-01

In this study, we characterized dimethylaminium (DMA + ) and trimethylaminium (TMA + ) in size-segregated atmospheric particles during three cruise campaigns in the marginal seas of China and one cruise campaign mainly in the northwest Pacific Ocean (NWPO). An 14-stage nano-MOUDI sampler was utilized for sampling atmospheric particles ranging from 18μm to 0.010μm. Among the four cruise campaigns, the highest concentrations of DMA + and TMA + in PM 10 were observed over the South Yellow Sea (SYS) in August 2015, i.e., 0.76±0.12nmolm -3 for DMA + (average value±standard deviation) and 0.93±0.13nmolm -3 for TMA + . The lowest values were observed over the NWPO in April 2015, i.e., 0.28±0.16nmolm -3 for DMA + and 0.22±0.12nmolm -3 for TMA + . In general, size distributions of the two ions exhibited a bi-modal pattern, i.e., one mode at 0.01-0.1μm and the other at 0.1-1.8μm. The two ions' mode at 0.01-0.1μm was firstly observed. The mode was largely enhanced in samples collected over the SYS in August 2015, leading to high mole ratios of (DMA + +TMA + )/NH 4 + in PM 0.1 (0.4±0.8, median value±standard deviation) and the ions' concentrations in PM 0.1 accounting for ~10% and ~40% of their corresponding concentrations in PM 10 . This implied that (DMA + +TMA + ) likely played an important role in neutralizing acidic species in the smaller particles. Using SO 4 2- , NO 3 - and NH 4 + as references, we confirm that the elevated concentrations of DMA + and TMA + in the 0.01-0.1μm size range were probably real signals rather than sampling artifacts. Copyright © 2016 Elsevier B.V. All rights reserved.

Application of a microplate-based ORAC-pyrogallol red assay for the estimation ofantioxidant capacity: First Action 2012.03.

PubMed

Ortiz, Rocío; Antilén, Mónica; Speisky, Hernán; Aliaga, Margarita E; López-Alarcón, Camilo; Baugh, Steve

2012-01-01

A method was developed for microplate-based oxygen radicals absorbance capacity (ORAC) using pyrogallol red (PGR) as probe (ORAC-PGR). The method was evaluated for linearity, precision, and accuracy. In addition, the antioxidant capacity of commercial beverages, such as wines, fruit juices, and iced teas, was measured. Linearity of the area under the curve (AUC) versus Trolox concentration plots was [AUC = (845 +/- 110) + (23 +/- 2) [Trolox, microM]; R = 0.9961, n = 19]. Analyses showed better precision and accuracy at the highest Trolox concentration (40 microM) with RSD and recovery (REC) values of 1.7 and 101.0%, respectively. The method also showed good linearity for red wine [AUC = (787 +/- 77) + (690 +/- 60) [red wine, microL/mL]; R = 0.9926, n = 17], precision and accuracy with RSD values from 1.4 to 8.3%, and REC values that ranged from 89.7 to 103.8%. Red wines showed higher ORAC-PGR values than white wines, while the ORAC-PGR index of fruit juices and iced teas presented a wide range of results, from 0.6 to 21.6 mM of Trolox equivalents. Product-to-product variability was also observed for juices of the same fruit, showing the differences between brands on the ORAC-PGR index.

Contact Quotient of Female Singers Singing Four Pitches for Five Vowels in Normal and Pressed Phonations.

PubMed

Ong Tan, Kendrich Graemer

2017-09-01

The present study aimed to investigate the contact quotient (CQ) values of breathy, normal, and pressed phonation types in four different sections of the female singing range. Electroglottography (EGG) and acoustic signals were recorded from 10 female singing teachers. Five vowels were sung for 1-3 seconds each, in three phonation types-normal, breathy, and pressed, in four pitches representing registration change points in the singing range. CQ values were automatically generated from the EGG signal using VoceVista at 35% threshold level. Sound pressure levels were checked in Praat. Unianova and correlations were performed using an SPSS program. CQ values of female participants in the study yielded ranges of 0.25-0.62 in normal and 0.34-0.73 in pressed. Normal and pressed CQ differed significantly from each other at P < 0.00. Breathy samples were not viable for analysis. A concentration of CQ values from 0.5 to 0.6 of both pressed low and pressed break samples was noted, but CQ values across the pitch range showed no significant trend. Normal and pressed phonation CQ values beyond the speaking pitch varied among the subjects. Pressed phonation CQ values were mostly higher, but the values were only relative to the corresponding normal phonation on the same pitch. Other measurements may be more suitable for measuring vocal fold impact stress in higher frequencies, thus, distinguishing normal from pressed singing. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Prediction of ore fluid metal concentrations from solid solution concentrations in ore-stage calcite: Application to the Illinois-Kentucky and Central Tennessee Mississippi Valley-type districts

NASA Astrophysics Data System (ADS)

Smith-Schmitz, Sarah E.; Appold, Martin S.

2018-03-01

Knowledge of the concentrations of Zn and Pb in Mississippi Valley-type (MVT) ore fluids is fundamental to understanding MVT deposit origin. Most previous attempts to quantify the concentrations of Zn and Pb in MVT ore fluids have focused on the analysis of fluid inclusions. However, these attempts have yielded ambiguous results due to possible contamination from secondary fluid inclusions, interferences from Zn and Pb in the host mineral matrix, and uncertainties about whether the measured Zn and Pb signals represent aqueous solute or accidental solid inclusions entrained within the fluid inclusions. The purpose of the present study, therefore, was to try to determine Zn and Pb concentrations in MVT ore fluids using an alternate method that avoids these ambiguities by calculating Zn and Pb concentrations in MVT ore fluids theoretically based on their solid solution concentrations in calcite. This method was applied to the Illinois-Kentucky and Central Tennessee districts, which both contain ore-stage calcite. Experimental partition coefficient (D) values from Rimstidt et al. (1998) and Tsusue and Holland (1966), and theoretical thermodynamic distribution coefficient (KD) values were employed in the present study. Ore fluid concentrations of Zn were likely most accurately predicted by Rimstidt et al. (1998) D values, based on their success in predicting known fluid inclusion concentrations of Mg and Mn, and likely also most accurately predicted ore fluid concentrations of Fe. All four of these elements have a divalent ionic radius smaller than that of Ca2+ and form carbonate minerals with the calcite structure. For both the Illinois-Kentucky and the Central Tennessee district, predicted ore fluid Zn and Fe concentrations were on the order of up to 10's of ppm. Ore fluid concentrations of Pb could only be predicted using Rimstidt et al. (1998) D values. However, these concentrations are unlikely to be reliable, as predicted ore fluid concentrations of Sr and Ba, which like Pb also have a divalent ionic radius larger than that of Ca2+ and form carbonate minerals with the aragonite structure, did not consistently agree well with known concentrations of Sr and Ba in fluid inclusions. The ore fluid Zn concentrations predicted in the present study lie within the range of Zn concentrations typical of modern sedimentary brines and are high enough to allow deposition of the observed amounts of Zn in the Illinois-Kentucky and Central Tennessee districts within ranges of geologically reasonable times and ore fluid flow velocities. If the pH of the Illinois-Kentucky and Central pH ore fluids was as low as current evidence suggests to be possible, then these ore fluids could simultaneously have transported enough sulfide with their Zn to account for the observed amounts of sphalerite in the districts.

Correlation of second virial coefficient with solubility for proteins in salt solutions.

PubMed

Mehta, Chirag M; White, Edward T; Litster, James D

2012-01-01

In this work, osmotic second virial coefficients (B(22)) were determined and correlated with the measured solubilities for the proteins, α-amylase, ovalbumin, and lysozyme. The B(22) values and solubilities were determined in similar solution conditions using two salts, sodium chloride and ammonium sulfate in an acidic pH range. An overall decrease in the solubility of the proteins (salting out) was observed at high concentrations of ammonium sulfate and sodium chloride solutions. However, for α-amylase, salting-in behavior was also observed in low concentration sodium chloride solutions. In ammonium sulfate solutions, the B(22) are small and close to zero below 2.4 M. As the ammonium sulfate concentrations were further increased, B(22) values decreased for all systems studied. The effect of sodium chloride on B(22) varies with concentration, solution pH, and the type of protein studied. Theoretical models show a reasonable fit to the experimental derived data of B(22) and solubility. B(22) is also directly proportional to the logarithm of the solubility values for individual proteins in salt solutions, so the log-linear empirical models developed in this work can also be used to rapidly predict solubility and B(22) values for given protein-salt systems. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

Regression model development and computational procedures to support estimation of real-time concentrations and loads of selected constituents in two tributaries to Lake Houston near Houston, Texas, 2005-9

USGS Publications Warehouse

Lee, Michael T.; Asquith, William H.; Oden, Timothy D.

2012-01-01

In December 2005, the U.S. Geological Survey (USGS), in cooperation with the City of Houston, Texas, began collecting discrete water-quality samples for nutrients, total organic carbon, bacteria (Escherichia coli and total coliform), atrazine, and suspended sediment at two USGS streamflow-gaging stations that represent watersheds contributing to Lake Houston (08068500 Spring Creek near Spring, Tex., and 08070200 East Fork San Jacinto River near New Caney, Tex.). Data from the discrete water-quality samples collected during 2005–9, in conjunction with continuously monitored real-time data that included streamflow and other physical water-quality properties (specific conductance, pH, water temperature, turbidity, and dissolved oxygen), were used to develop regression models for the estimation of concentrations of water-quality constituents of substantial source watersheds to Lake Houston. The potential explanatory variables included discharge (streamflow), specific conductance, pH, water temperature, turbidity, dissolved oxygen, and time (to account for seasonal variations inherent in some water-quality data). The response variables (the selected constituents) at each site were nitrite plus nitrate nitrogen, total phosphorus, total organic carbon, E. coli, atrazine, and suspended sediment. The explanatory variables provide easily measured quantities to serve as potential surrogate variables to estimate concentrations of the selected constituents through statistical regression. Statistical regression also facilitates accompanying estimates of uncertainty in the form of prediction intervals. Each regression model potentially can be used to estimate concentrations of a given constituent in real time. Among other regression diagnostics, the diagnostics used as indicators of general model reliability and reported herein include the adjusted R-squared, the residual standard error, residual plots, and p-values. Adjusted R-squared values for the Spring Creek models ranged from .582–.922 (dimensionless). The residual standard errors ranged from .073–.447 (base-10 logarithm). Adjusted R-squared values for the East Fork San Jacinto River models ranged from .253–.853 (dimensionless). The residual standard errors ranged from .076–.388 (base-10 logarithm). In conjunction with estimated concentrations, constituent loads can be estimated by multiplying the estimated concentration by the corresponding streamflow and by applying the appropriate conversion factor. The regression models presented in this report are site specific, that is, they are specific to the Spring Creek and East Fork San Jacinto River streamflow-gaging stations; however, the general methods that were developed and documented could be applied to most perennial streams for the purpose of estimating real-time water quality data.

New insights into agricultural pesticide pollution through a complete and continuous pesticide screening during one growing season in five small Swiss streams

NASA Astrophysics Data System (ADS)

Mangold, Simon; Doppler, Tobias; Spycher, Simon; Langer, Miriam; Junghans, Marion; Kunz, Manuel; Stamm, Christian; Singer, Heinz

2017-04-01

Agricultural pesticides are regularly found in many surface waters draining agricultural areas. Due to large fluctuations in concentration over time and the potentially high number of pesticides, it is difficult to obtain a complete overview of the real pollution level. This collaborative project between research, federal and cantonal authorities in Switzerland aimed for a comprehensive assessment of pesticide pollution in five small agricultural streams to tackle this knowledge gap. The five streams are located in catchments (1.5 to 9 km2) with intensive agriculture covering a wide range of crops including vegetables, vineyards and orchards. Twelve-hour composite samples were collected continuously from March until the end of August 2015 with automatic sampling devices, yielding 360 samples per site. Using precipitation and water level data, we differentiated between discharge events and low-flow periods. Samples from discharge events where measured individually whereas samples taken during dry weather were pooled for the analysis. This procedure resulted in a complete concentration profile over the entire monitoring period covered by 34 - 60 samples per site. The analysis, using liquid chromatography coupled to high resolution mass spectrometry involved a target screening of about 220 pesticides. The measured concentrations were compared to chronic and acute environmental quality standards (EQS values) resulting in risk quotients RQs, which are the ratios between measured concentrations and the respective EQS values. Despite the small size of the catchments, we observed a large pesticide diversity in all of them with 68 to 103 detected compounds per study area. At all sites, chronic EQS values were exceeded. However, the exposure levels varied substantially among catchments. Maximum chronic RQs per site ranged between 1.1 and 48.8 and the duration of EQS exceedance varied between 2 weeks and 5.5 months. Additionally, the data reveal (very) high concentration peaks reaching up to 40 μg L-1 for single active ingredients. Of 15 compounds measured at high concentrations, several measured concentrations exceeded acute EQS values in three of the five areas for a duration of up to 2.5 months. Concentration peaks were often linked to discharge events but not exclusively. These findings demonstrate that rain driven processes were important causes of the observed concentration levels but that additional (possibly point) sources need to be considered for a comprehensive understanding of pesticide exposure. Overall, the results from these five catchments provide an unique insight into the diversity of pesticide pollution of small streams across a wide range of natural conditions in Switzerland. The spatial differences indicate that the intensity of pesticide use alone cannot explain the level of exposure but point to the influence of landscape characteristics such as topography, the connectivity of field to the stream network or the number of connected farmyards.

Treatment and therapeutic monitoring of canine hypothyroidism.

PubMed

Dixon, R M; Reid, S W J; Mooney, C T

2002-08-01

Thirty-one dogs with spontaneous hypothyroidism were treated with thyroid hormone replacement therapy (THRT) and monitored for approximately three months. Good clinical and laboratory control was ultimately achieved in all cases with a mean L-thyroxine (T4) dose of 0.026 mg/kg administered once daily. There was a significant increase and decrease in circulating total T4 and canine thyroid stimulating hormone (cTSH) concentrations, respectively, after starting THRT. After commencing treatment, 11 cases subsequently required an increase and three cases required a decrease in dose to achieve optimal clinical control. Median (semi interquartile range [SIR]) circulating six-hour post-pill total T4 (53.6 [27.91 nmol/litre) and cTSH (0.03 [0] microg/litre) concentrations were significantly increased and decreased, respectively, in treated dogs that did not require a dose change; corresponding values in treated dogs in which an increase in dose was required were 29.3 (12.7) nmol/litre and 0.15 (0.62) microg/litre, respectively. However, circulating cTSH measurement was of limited value in assessing therapeutic control because, although increased values were associated with inadequate therapy, reference range cTSH values were common in inadequately treated dogs. Lethargy and mental demeanour were typically the first clinical signs to improve, with significant bodyweight reduction occurring within two weeks of commencing THRT. Routine clinicopathological monitoring was of value in confirming a general metabolic response to THRT, but was of limited value in accurately monitoring cases or tailoring therapy in individual cases.

Development of a direct competitive enzyme-linked immunosorbent assay for parathion residue in food samples.

PubMed

Gui, Wen-Jun; Liu, Yi-Hua; Wang, Chun-Mei; Liang, Xiao; Zhu, Guo-Nian

2009-10-01

A heterologous direct competitive enzyme-linked immunosorbent assay (ELISA) for parathion residue determination is described based on a monoclonal antibody and a new competitor. The effects of several physicochemical factors, such as methanol concentration, ionic strength, pH value, and sample matrix, on the performance of the ELISA were optimized for the sake of obtaining a satisfactory assay sensitivity. Results showed that when the assay medium was in the optimized condition (phosphate buffer solution [PBS] containing 10% [v/v] methanol and 0.2 mol/L NaCl at a pH value of 5.0), the sensitivity (estimated as the IC(50) value) and the limit of detection (LOD, estimated as the IC(10) value) were 1.19 and 0.08 ng/ml, respectively. The precision investigation indicated that the intraassay precision values all were below 10% and that the interassay precision values ranged from 4.89 to 19.12%. In addition, the developed ELISA showed a good linear correlation (r(2)=0.9962) to gas chromatography within the analyte's concentration range of 0.1 to 16 ng/ml. When applied to the fortified samples (parathion adding level: 5-15 microg/kg), the developed ELISA presented mean recoveries of 127.46, 122.52, 91.92, 124.01, 129.72, 99.37, and 87.17% for tomato, cucumber, banana, apple, orange, pear, and sugarcane, respectively. Results indicated that the established ELISA is a potential tool for parathion residue determination.

Determination of Perfluorinated Alkyl Acid Concentrations in Biological Standard Reference Materials

EPA Science Inventory

Standard reference materials (SRMs) are homogeneous, well-characterized materials used to validate measurements and improve the quality of analytical data. The National Institute of Standards and Technology (NIST) has a wide range of SRMs that have mass fraction values assigned ...

Exposure to bioaerosols in the selected agricultural facilities of the Ukraine and Poland - a review.

PubMed

Tsapko, Valentin G; Chudnovets, Alla J; Sterenbogen, Marina J; Papach, Vladimir V; Dutkiewicz, Jacek; Skórska, Czesława; Krysińska-Traczyk, Ewa; Golec, Marcin

2011-01-01

The aim of this work was to review the studies on bioaerosols which were carried out in the years 1972-2009 in following branches of agricultural industry in the Ukraine and Poland: animal farms for cows and pigs, animal feed facilities, production of biofuel from rape, herb farms and herb processing facilities. In all facilities were determined: concentration of dust and microorganisms in the air and species composition of microflora. Moreover, in Polish animal farms, herb farms and herb processing facilities, as well as in the Ukrainian animal feed facilities, was determined the concentration of bacterial endotoxin in the air. Dust concentrations in animal farms located in the Ukraine and Poland ranged from 6-200 mg/m(3) and from 0.25-14.05 mg/m(3), respectively, while in animal feed facilities they ranged from 35-306 mg/m(3) and from 3.8-405 mg/m(3), respectively. Dust concentrations in the facilities producing biofuel from rape in the Ukraine were in the range 3.6-28 mg/m(3), whereas on herb farms and in herb processing facilities in Poland they were in the range 0.8- 1,319.6 mg/m(3), and 2.2-946 mg/m(3), respectively. The determined values exceeded in most cases the maximal acceptable concentration (MAC) which in the Ukraine and Poland is equal to 4 mg/m(3). The concentrations of microorganisms on animal farms located in the Ukraine and Poland ranged from 5.5 x 10(4)- 1.9 x 10(7) cfu/m(3) and from 4.7 x 10(4)-1.5 x 10(6) cfu/m(3), respectively, while in animal feed facilities they ranged from 2.7 x 10(4)-2.6 x 10(9) cfu/m(3) and from 1.7 x 10(3)-2.0 x 10(6) cfu/m(3), respectively. Concentrations of microorganisms in the facilities producing biofuel from rape in the Ukraine were in the range 1.5 x 10(3)-5.7 x 10(6) cfu/m(3), whereas on herb farms and in herb processing facilities in Poland they were in the ranges of 8.8 x 10(2)-8.0 x 10(6) cfu/m(3), and 9.7 x 10(3)-6.3 x 10(5) cfu/m(3), respectively. The determined values exceeded in most cases the maximal acceptable concentration (MAC) which in the Ukraine is equal to 5.0 x 10(4) cfu/m(3). The concentrations of endotoxin in Polish animal houses were in the range 0.00125-75.0 ug/m(3), whereas on herb farms and herb processing facilities they were in the ranges of 0.0045- 2,448.8 ug/m(3) and 0.2-681.0 ug/m(3), respectively, and in the Ukrainian animal feed facilities were within the range 0.008-240.0 ug/m(3). They exceeded in most cases the level of 0.2 ug/m(3) proposed as a threshold. In the air microflora of examined facilities prevailed Gram-positive bacteria (corynebacteria, cocci, spore-forming bacilli, actinomycetes) of which some (Arthrobacter spp., thermophilic actinomycetes) could be a cause of allergic alveolitis (hypersensitivity pneumonitis). Among Gram-negative bacteria isolated from the air of agricultural settings dominated the epiphytic species Pantoea agglomerans, possessing potent allergenic and endotoxic properties. Fungi were abundant in the air of the Ukrainian agricultural settings and comprised species able to produce harmful mycotoxins. In conclusion, the airborne biological factors in stated concentrations may exert harmful effects on the state of the health of exposed workers. Formation of the bioaerosol depends on the specificity of the setting, kind of technological operations, degree of mechanization, properties of processed materials, temperature and humidity, and concentration of dust in the air.

Determination of lipid oxidation products in vegetable oils and marine omega-3 supplements.

PubMed

Halvorsen, Bente Lise; Blomhoff, Rune

2011-01-01

There is convincing evidence that replacing dietary saturated fats with polyunsaturated fats (PUFA) decreases risk of cardiovascular diseases. Therefore, PUFA rich foods such as vegetable oils, fatty fish, and marine omega-3 supplements are recommended. However, PUFA are easily oxidizable and there is concern about possible negative health effects from intake of oxidized lipids. Little is known about the degree of lipid oxidation in such products. To assess the content of lipid oxidation products in a large selection of vegetable oils and marine omega-3 supplements available in Norway. Both fresh and heated vegetable oils were studied. A large selection of commercially available vegetable oils and marine omega-3 supplements was purchased from grocery stores, pharmacies, and health food stores in Norway. The content of lipid oxidation products were measured as peroxide value and alkenal concentration. Twelve different vegetable oils were heated for a temperature (225°C) and time (25 minutes) resembling conditions typically used during cooking. The peroxide values were in the range 1.04-10.38 meq/kg for omega-3 supplements and in the range 0.60-5.33 meq/kg for fresh vegetable oils. The concentration range of alkenals was 158.23-932.19 nmol/mL for omega-3 supplements and 33.24-119.04 nmol/mL for vegetable oils. After heating, a 2.9-11.2 fold increase in alkenal concentration was observed for vegetable oils. The contents of hydroperoxides and alkenals in omega-3 supplements are higher than in vegetable oils. After heating vegetable oils, a large increase in alkenal concentration was observed.

Variability of Plant Wax Concentrations and Carbon Isotope Values in Surface Lake Sediments Provide Clues into Their Transport and Deposition

NASA Astrophysics Data System (ADS)

Bates, B.; Lowell, T. V.; Diefendorf, A. F.; Freimuth, E. J.; Stewart, A. K.

2017-12-01

Plant wax compounds preserved in lake sediments are used as proxies for paleohydrologic reconstructions. Despite their presence in lake sediments, little is known about their transport from plants to their deposition in lake sediments. By drawing on the leaf and pollen taphonomy literature combined with sediment focusing models, it is possible to develop several working hypotheses for the transport and deposition of plant waxes in lake sediments. An improved understanding of plant wax transport and deposition into lake sediments is necessary to increase the accuracy of paleohydrologic reconstructions. To better understand the controls on plant wax transport and deposition in lake sediment, we analyzed the sedimentary plant waxes from 3 lakes in the Adirondack Mountains of New York. These lakes were chosen to capture a range of basin-specific properties to evaluate their influences on the transport and deposition of plant wax compounds in surface sediments. We spatially characterized sediment properties with surface sediment samples and high-resolution underwater imaging, acoustically profiled the sub-bottom, and measured temperature profiles. From each site, we measured n-alkanes, bulk organic content (loss-on-ignition), bulk carbon and nitrogen concentrations, C:N ratios, and bulk carbon isotopes. Preliminary n-alkane concentrations and chain length distributions, as well as bulk carbon isotopes, are variable within each lake basin suggesting a mix of aquatic and terrestrial sources. The bulk carbon isotope values for two of the three lakes show a similar range of -2‰ compared to a range of -6.3‰ at the third lake. Likewise, the range of total n-alkane concentrations is much higher in the third lake suggesting that the controls on the distribution of n-alkanes and organic carbon are different between lakes. For terrestrial plant waxes, we find low n-alkane concentrations in sandy nearshore sediments relative to higher n-alkane concentrations in deeper fine-grained sediments. Combined, this information suggests that littoral processes focus organic compounds and fine sediments towards the main depo-center of the lake. These and other observations highlight important relationships between basin-specific properties and processes controlling the transport and deposition of plant wax compounds.

A study examining the bias of albumin and albumin/creatinine ratio measurements in urine.

PubMed

Jacobson, Beryl E; Seccombe, David W; Katayev, Alex; Levin, Adeera

2015-10-01

The objective of the study was to examine the bias of albumin and albumin/creatinine (ACR) measurements in urine. Pools of normal human urine were augmented with purified human serum albumin to generate a series of 12 samples covering the clinical range of interest for the measurement of ACR. Albumin and creatinine concentrations in these samples were analyzed three times on each of 3 days by 24 accredited laboratories in Canada and the USA. Reference values (RV) for albumin measurements were assigned by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) comparative method and gravimetrically. Ten random urine samples (check samples) were analyzed as singlets and albumin and ACR values reported according to the routine practices of each laboratory. Augmented urine pools were shown to be commutable. Gravimetrically assigned target values were corrected for the presence of endogenous albumin using the LC-MS/MS comparative method. There was excellent agreement between the RVs as assigned by these two methods. All laboratory medians demonstrated a negative bias for the measurement of albumin in urine over the concentration range examined. The magnitude of this bias tended to decrease with increasing albumin concentrations. At baseline, only 10% of the patient ACR values met a performance limit of RV ± 15%. This increased to 84% and 86% following post-analytical correction for albumin and creatinine calibration bias, respectively. International organizations should take a leading role in the standardization of albumin measurements in urine. In the interim, accuracy based urine quality control samples may be used by clinical laboratories for monitoring the accuracy of their urinary albumin measurements.

Estimated Glomerular Filtration Rate Is a Poor Predictor of Concentration for a Broad Range of Uremic Toxins

PubMed Central

Schepers, Eva; Barreto, Daniela V.; Barreto, Fellype C.; Liabeuf, Sophie; Van Biesen, Wim; Verbeke, Francis; Glorieux, Griet; Choukroun, Gabriel; Massy, Ziad; Vanholder, Raymond

2011-01-01

Summary Background and objectives The degree of chronic kidney disease (CKD) is currently expressed in terms of GFR, which can be determined directly or estimated according to different formulas on the basis of serum creatinine and/or cystatin C measurements (estimated GFR [eGFR]). The purpose of this study was to investigate whether eGFR values are representative for uremic toxin concentrations in patients with different degrees of CKD. Design, setting, participants, & measurements Associations between eGFR based on serum cystatin C and different uremic solutes (mol wt range 113 to 240 D; determined by colorimetry, HPLC, or ELISA) were evaluated in 95 CKD patients not on dialysis (CKD stage 2 to 5). The same analysis was also applied for six other eGFR formulas. Results There was a substantial disparity in fits among solutes. In linear regression, explained variance of eGFR was extremely low for most solutes, with eGFR > 0.4 only for creatinine. The other eGFR formulations gave comparably disappointing results with regard to their association to uremic solutes. Relative similarity in R2 values per solute for the different eGFR values and the strong disparity in values between solutes suggest that the differences in R2 are mainly due to discrepancies in solute handling apart from GFR. Conclusions eGFR is poorly associated with concentrations of all studied uremic toxins in patients with different degrees of CKD, correlates differently with each individual solute, and can thus not be considered representative for evaluating the accumulation of solutes in the course of CKD. PMID:21617084

Measuring milk fat content by random laser emission

NASA Astrophysics Data System (ADS)

Abegão, Luis M. G.; Pagani, Alessandra A. C.; Zílio, Sérgio C.; Alencar, Márcio A. R. C.; Rodrigues, José J.

2016-10-01

The luminescence spectra of milk containing rhodamine 6G are shown to exhibit typical signatures of random lasing when excited with 532 nm laser pulses. Experiments carried out on whole and skim forms of two commercial brands of UHT milk, with fat volume concentrations ranging from 0 to 4%, presented lasing threshold values dependent on the fat concentration, suggesting that a random laser technique can be developed to monitor such important parameter.

Measuring milk fat content by random laser emission.

PubMed

Abegão, Luis M G; Pagani, Alessandra A C; Zílio, Sérgio C; Alencar, Márcio A R C; Rodrigues, José J

2016-10-12

The luminescence spectra of milk containing rhodamine 6G are shown to exhibit typical signatures of random lasing when excited with 532 nm laser pulses. Experiments carried out on whole and skim forms of two commercial brands of UHT milk, with fat volume concentrations ranging from 0 to 4%, presented lasing threshold values dependent on the fat concentration, suggesting that a random laser technique can be developed to monitor such important parameter.

Stress analysis of advanced attack helicopter composite main rotor blade root end lug

NASA Technical Reports Server (NTRS)

Baker, D. J.

1982-01-01

Stress analysis of the Advanced Attack Helicopter (AAH) composite main rotor blade root end lug is described. The stress concentration factor determined from a finite element analysis is compared to an empirical value used in the lug design. The analysis and test data indicate that the stress concentration is primarily a function of configuration and independent of the range of material properties typical of Kevlar-49/epoxy and glass epoxy.

Individual and environmental risk factors for high blood lead concentrations in Danish indoor shooters.

PubMed

Grandahl, Kasper; Suadicani, Poul; Jacobsen, Peter

2012-08-01

International studies have shown blood lead at levels causing health concern in recreational indoor shooters. We hypothesized that Danish recreational indoor shooters would also have a high level of blood lead, and that this could be explained by shooting characteristics and the physical environment at the shooting range. This was an environmental case study of 58 male and female shooters from two indoor shooting ranges with assumed different ventilation and cleaning conditions. Information was obtained on general conditions including age, gender, tobacco and alcohol use, and shooting conditions: weapon type, number of shots fired, frequency of stays at the shooting range and hygiene habits. A venous blood sample was drawn to determine blood lead concentrations; 14 non-shooters were included as controls. Almost 60% of the shooters, hereof five out of 14 women, had a blood lead concentration above 0.48 micromol/l, a level causing long-term health concern. All controls had blood lead values below 0.17 micromol/l. Independent significant associations with blood lead concentrations above 0.48 micromol/l were found for shooting at a poorly ventilated range, use of heavy calibre weapons, number of shots and frequency of stays at the shooting range. A large proportion of Danish recreational indoor shooters had potentially harmful blood lead concentrations. Ventilation, amounts of shooting, use of heavy calibre weapons and stays at the shooting ranges were independently associated with increased blood lead. The technical check at the two ranges was performed by the Danish Technological Institute and costs were defrayed by the Danish Rifle Association. To pay for the analyses of blood lead, the study was supported by the The Else & Mogens Wedell-Wedellsborg Foundation. The Danish Regional Capital Scientific Ethics Committee approved the study, protocol number H-4-2010-130.

REVISED GUIDELINES FOR USING CELLULOSE DEGRADATION PRODUCT-IMPACTED KD VALUES FOR PERFORMANCE ASSESSMENTS AND COMPOSITE ANALYSES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaplan, D.

2012-05-14

Cellulosic materials include wood, paper, rags, and cardboard products. These materials are co-disposed with radiological waste at the Savannah River Site's (SRS) E-Area Low-Level Waste Facility (ELLWF). Cellulosic materials readily degrade in the environment to form cellulose degradation products (CDP) that will partition to the sediment or remain mobile in the groundwater. Savannah River National Lab (SRNL) has conducted studies to estimate the impact of CDP on radionuclide sorption to SRS sediments (Kd values). It was found that CDP impact on radionuclide sorption varies with radionuclide and CDP concentration. Furthermore, it was found that the amount of carbon (C) inmore » the system could increase or decrease Kd values with respect to the base case of when no CDP was added. Throughout the expected pH range of the ELLWF, a low concentration of CDP in the system would increase Kd values (because C would sorb to the sediment and provide more exchange sites for radionuclides to sorb), whereas greater concentrations of CDP ({ge}20 mg/L C) would decrease Kd values (because C would remain in solution and complex the radionuclide and not permit the radionuclide to sorb to the sediment). A review of >230 dissolved organic carbon (DOC) groundwater concentrations in the Old Radioactive Waste Burial Ground (ORWBG) at the SRS indicated that the average DOC concentration, a gross measure of CDP, was 5 mg/L C. At approximately this DOC concentration, the laboratory studies demonstrated that no anions (Tc, I, or Se) or cations (Ni, Sr, Ce, Eu, Zr, or Th) have decreased sorption in the presence of carbon (an analogue for CDP).« less

Variable anodic thermal control coating on aluminum

NASA Technical Reports Server (NTRS)

Duckett, R. J.; Gilliland, C. S.

1983-01-01

A variable thermal control coating (modified chromic acid anodizing) has been developed to meet the needs for the thermal control of spacecraft. This coating, with controlled variable ranges of 0.10 to 0.72 thermal emittance and 0.2 to 0.4 solar absorptance, allows the user to select any value of thermal emittance and solar absorptance within the range specified and obtain both values within + or - 0.02. Preliminary solar stability has shown less than 15 percent degradation over 2000 hours of vacuum solar exposure. The technique has been determined to be sensitive to the parameters of voltage, rate of voltage application, time, temperature, acid concentration, and material pretreatment.

Failure of Quality Control Measures To Prevent Reporting of False Resistance to Imipenem, Resulting in a Pseudo-Outbreak of Imipenem-Resistant Pseudomonas aeruginosa

PubMed Central

Carmeli, Yehuda; Eichelberger, Karen; Soja, Don; Dakos, Joanna; Venkataraman, Lata; DeGirolami, Paola; Samore, Matthew

1998-01-01

False results showing an outbreak of Pseudomonas aeruginosa with resistance to imipenem were traced to a defective lot of microdilution MIC testing panels. These panels contained two- to threefold lower concentrations of imipenem than expected and resulted in artifactual two- to fourfold increases in MICs of imipenem. The quality-control MIC results for Pseudomonas aeruginosa ATCC 27853 were 4 μg/ml, the highest value within the range recommended by the National Committee for Clinical Laboratory Standards. We recommend that this value be considered out of the quality-control range. PMID:9466787

Range of therapeutic metformin concentrations in clinical blood samples and comparison to a forensic case with death due to lactic acidosis.

PubMed

Hess, C; Unger, M; Madea, B; Stratmann, B; Tschoepe, D

2018-05-01

Due to a lack of reference values for blood concentration of metformin in the literature, the forensic evaluation of metformin findings in blood samples is difficult. Interpretations with regard to the assessment of blood concentrations as well as an estimation of the ingested metformin amounts are often vague. Furthermore, post mortem evaluation of death due to lactic acidosis because of metformin is difficult since renal performance or lactate concentrations can not always reliably be determined after death. To describe a concentration range in clinical samples after chronic use of metformin, metformin serum concentrations were determined in serum samples of 95 diabetic patients receiving daily doses of 500mg-3000mg of metformin. The analyses of metformin was carried out using a validated high performance liquid chromatograph coupled to triple quadrupole mass spectrometry (LC-QQQ-MS). On average, metformin concentrations were 1846ng/mL (

Origin of sulfide and phosphate deposits in Upper Proterozoic carbonate strata, Irece basin, Bahia, Brazil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kyle, J.R.; Misi, A.

1991-03-01

Carbonate strata of the Una Group represent late Proterozoic platform sedimentation in the Irece basin of north-central Brazil. Stratabound sulfide- and phosphate-rich units occur within a 50-m thick tidal flat sequence of dolomitic limestone and cherty dolomite. Three types of primary phosphate concentrations are present: columnar stromatolitic, laminar stromatolitic, and intraclastic. Resedimented phosphate clasts and phosphatic units interbedded with non phosphatic dolomites suggest early diagenetic replacement of algal carbonate units. Local stratabound Zn-Pb-Ag sulfide concentrations at the Tres Irmas prospect occur within silty dolomite with shallow water sedimentary structures and local disturbed laminae, synsedimentary faults, and breccias. Sulfide minerals includemore » pyrite, sphalerite, galena, marcasite, jordanite, tetrahedrite, and covellite. Pyrite crystal aggregates commonly show bladed forms. Nodular aggregates of length-slow quartz are locally associated with sulfides. Sulfur isotope analyses indicate relatively uniform heavy {delta}{sup 34}S values. Barite shows a {delta}{sup 34}S range from +25.2 to +29.6{per thousand}, CDT. Pyrite and sphalerite representative of a variety of textural types have a {delta}{sup 34}S range of +20.2 to +22.6{per thousand}. Late Proterozoic evaporite sulfates show a wide range of {delta}{sup 34} S values from about +10 to +28{per thousand}. Thus, the {delta}{sup 34}S values for Irece barite could reflect original seawater sulfate values. However, the relatively heavy {delta}{sup 34}S values of the associated sulfides suggests that the original seawater sulfate was modified by bacterial sulfate reduction processes in shallow sea floor sediments. Textural and {delta}{sup 34}S evidence suggests that a later stage of metallic mineralization scavenged sulfur from preexisting sulfides or from direct reduction of evaporitic sulfate minerals.« less

Water-quality data from storm runoff after the 2007 fires, San Diego County, California

USGS Publications Warehouse

Mendez, Gregory O.

2010-01-01

The U.S. Geological Survey collected water-quality samples during the first two storms after the Witch and Harris Fires (October 2007) in southern California. The sampling locations represent an urban area (two residential sites in Rancho Bernardo that were affected by the Witch Fire; a drainage ditch and a storm drain) and a rural area (Cotton-wood Creek, which was downstream of a mobile home park destroyed by the Harris Fire). Fires produce ash and solid residues that contain soluble chemicals that can contaminant runoff. The contaminants, whether sorbed to soil and ash or dissolved, can seriously affect the quality of water supplies and sensitive ecosystems. Stormflow water samples were analyzed for field parameters, optical properties, and for a variety of constituents, including nutrients, dissolved organic carbon (DOC), suspended sediment, and metals. pH values for storm runoff from the urban areas (7.6 to 8.5) were less than pH values for ash and burned soil from previous studies (12.5 to 13). pH values for storm runoff from the rural area (about 7.7) also were less than pH values for ash and burned soil collected from the rural area (8.6 to 11.8), but were similar to pH values for wildland burned soil from previous studies. Turbidity values were much lower for the urban area than for the rural area. Nitrate concentrations in stormflow samples from all sites were less than a quarter of the U.S. Environmental Protection Agency's (2006) maximum allowable contaminant level of 10 milligrams per liter (mg/L) (as nitrogen). Phosphorus concentrations were half as much in filtered samples and two orders of magnitude smaller in unfiltered samples at the urban sites than at the rural site. DOC concentrations in stormflow samples were one order of magnitude lower at the urban sites than at the rural site. Ultraviolet (UV) absorbance at 254 nanometers (UV254) in samples ranged from 0.145 to 0.782 per centimeter (cm-1). UV-absorbance data at the urban sites indicate that the composition of DOC remained similar during both storms even though the DOC concentration changed. Total suspended-sediment concentrations ranged from 0.01 to 0.24 mg/L at the urban area, and were 12 and 45 mg/L at the rural area. Trace metals analyzed in unfiltered water samples had lower concentrations in the urban area than in the rural area. No concentrations of arsenic or mercury measured in the samples were above aquatic-life criteria. In the urban area, most concentrations of aluminum, iron, and lead exceeded aquatic-life criteria. In the rural area, aluminum, cadmium, iron, lead, and zinc exceeded aquatic-life criteria. Concentrations of aluminum and iron were two orders of magnitude larger in the rural area than in the urban area.

Low plasma triiodothyronine concentrations and outcome in preterm infants.

PubMed Central

Lucas, A; Rennie, J; Baker, B A; Morley, R

1988-01-01

A major association has been found between low plasma triiodothyronine concentrations in preterm neonates and their later developmental outcome. Plasma triiodothyronine concentration was measured longitudinally in 280 preterm infants below 1850 g birth weight. Babies whose lowest recorded concentration was less than 0.3 nmol/l had, at 18 months' corrected age, 8.3 and 7.4 point disadvantages in Bayley mental and motor scales and a 8.6 point disadvantage on the academic scale of Developmental Profile II, even after adjusting for a range of antenatal and neonatal factors known to influence later development. Low concentrations of triiodothyronine were strongly associated with infant mortality, but not after adjusting for the presence of respiratory illness. There was no association between plasma triiodothyronine concentrations and somatic growth up to 18 months, and no association with necrotising enterocolitis or later cerebral palsy. Data on postnatal changes in plasma triiodothyronine concentrations are presented for reference purposes. While cited reference ranges for plasma triiodothyronine concentration appear suitable for well infants above 1500 g birth weight, smaller or ill babies often have very low values for many weeks. Our data are relevant to the debate on endocrine 'replacement' treatment in premature babies. PMID:2461683

Radioactivity and geochemistry of selected mineral-spring waters in the Western United States; basic data and multivariate statistical analysis

USGS Publications Warehouse

Felmlee, J.K.; Cadigan, R.A.

1982-01-01

Multivariate statistical analyses were performed on data from 156 mineral-spring sites in nine Western States to analyze relationships among the various parameters measured in the spring waters. Correlation analysis and R-mode factor analysis indicate that three major factors affect water composition in the spring systems studied: (1) duration of water circulation, (2) depth of water circulation, and (3) partial pressure of carbon dioxide. An examination of factor scores indicates that several types of hydrogeologic systems were sampled. Most of the samples are (1) older water from deeper circulating systems having relatively high salinity, high temperature, and low Eh or (2) younger water from shallower circulating systems having relatively low salinity, low temperature, and high Eh. The rest of the samples are from more complex systems. Any of the systems can have a relatively high or low content of dissolved carbonate species, resulting in a low or high pH, respectively. Uranium concentrations are commonly higher in waters of relatively low temperature and high Eh, and radium concentrations are commonly higher in waters having a relatively high carbonate content (low pH) and, secondarily, relatively high salinity. Water samples were collected and (or) measurements were taken at 156 of the 171 mineral-spring sites visited. Various samples were analyzed for radium, uranium, radon, helium, and radium-228 as well as major ions and numerous trace elements. On-site measurements for physical properties including temperature, specific conductance, pH, Eh, and dissolved oxygen were made. All constituents and properties show a wide range of values. Radium concentrations range from less than 0.01 to 300 picocuries per liter; they average 1.48 picocuries per liter and have an anomaly threshold value of 171 picocuries per liter for the samples studied. Uranium concentrations range from less than 0.01 to 120 micrograms per liter and average 0.26 micrograms per liter; they have an anomaly threshold value of 48.1 micrograms per liter. Radon content ranges from less than 10 to 110,000 picocuries per liter, averages 549 picocuries per liter and has an anomaly threshold of 20,400 picocuries per liter. Helium content ranges from -1,300 to +13,000 parts per billion relative to atmospheric helium; it averages +725 parts per billion and has an anomaly threshold of 10,000 parts per billion. Radium-228 concentrations range from less than 2.0 to 33 picocuries per liter; no anomaly threshold was determined owing to the small number of samples. All of the anomaly thresholds may be somewhat high because the sampling was biased toward springs likely to be radioactive. The statistical variance in radium and uranium concentrations unaccounted for by the identified factors testifies to the complexity of some hydrogeologic systems. Unidentified factors related to geologic setting and the presence of uranium-rich rocks in the systems also affect the observed concentrations of the radioactive elements in the water. The association of anomalous radioactivity in several springs with nearby known uranium occurrences indicates that other springs having anomalous radioactivity may also be associated with uranium occurrences as yet undiscovered.

Determination of Mercury Content in a Shallow Firn Core from Summit, Greenland by Isotope Dilution Inductively Coupled Plasma Mass Spectrometry

NASA Technical Reports Server (NTRS)

Mann, Jacqueline L.; Long, Stephen E.; Shuman, Christopher A.; Kelly, W. Robert

2003-01-01

The total mercury Hg content was determined in 6 cm sections of a near-surface 7 m firn core and in surrounding surface snow from Summit, Greenland (elevation: 3238 m, 72.58 N, 38.53 W) in May 2001 by isotope dilution cold-vapor inductively coupled plasma mass spectrometry (ID-CV-ICP-MS). The focus of this research was to evaluate the capability of the ID-CV-ICPMS technique for measuring trace levels of Hg typical of polar snow and firn. Highly enriched Hg-201 isotopic spike is added to approximately 10 ml melted core and thoroughly mixed. The Hg(+2) in the sample is reduced on line with tin (II) chloride (SnCl2) and the elemental Hg (Hg(0)) vapor pre-concentrated on to gold gauze using a commercial amalgam system. The Hg is then thermally desorbed and introduced into a quadrupole ICP-MS. The blank corrected Hg concentrations determined for all samples ranged from 0.25 ng/L to 1.74 ng/L (ppt) (average 0.59 ng/L plus or minus 0.28 ng/L) and fall within the range of those previously determined by Boutron et al., 1998 (less than or equal to 0.05 ng/L to 2.0 ng/L) for the Summit site. The average blank value was 0.19 ng/L plus or minus 0.045 ng/L (n=6). The Hg values specifically for the firn core range from 0.25 ng/L to 0.87 ng/L (average 0.51 ng/L plus or minus 0.13 ng/L) and show both values declining with time and larger variability in concentration in the top 1.8 m.

137Cs soil-to-plant transfer for individual species in a semi-natural grassland. Influence of potassium soil content.

PubMed

Ciuffo, Liliana; Velasco, Hugo; Belli, Mar; Sansone, Umberto

2003-09-01

In the present study we assessed the radiocaesium uptake by plants in order to piece together information on factors affecting the uptake processes, particularly K supply and plant species differences. Vegetation uptake from soil contaminated by the Chernobyl accident was compared at two semi-natural grasslands. The Cs/K discrimination factor (DF), which is often used to evaluate a plant's efficiency in absorbing nutrients from soil, was estimated. The obtained DF values (0.01 to 0.8) vary with K soil concentrations and plant species, indicating that the (40)K is more efficiently absorbed than (137)Cs. The soil-to-plant relationship was evaluated by means of the transfer factor (TF). The (137)Cs TF(sp) values obtained from separated plant species varied within the range of 0.016 to 0.400 (site 1) and 0.017 to 0.171 (site 2). When mixed grass samples were considered a large variation was observed, mainly for site 1. The (137)Cs TF(mix) ranges were: 0.018 to 0.250 for site 1 and 0.017 to 0.167 for site 2. These values fall within the range of TFs commonly reported (0.0001-1). Our present data suggest that these pastures are apt for forage use. Different plant species presented different individual behavior regarding their (137)Cs TF(sp) when the (40)K soil activity concentration was taken in account. For most of the species analyzed, we observed a gradual decrease in the individual (137)Cs TF(sp) when the (40)K soil activity concentration was increased, with the exception of Taraxacum officinale at one of the sampling sites.

Contribution of uranium to gross alpha radioactivity in some environmental samples in Kuwait

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bou-Rabee, F.; Bakir, Y.; Bem, H.

1995-08-01

This study was done in connection with the use of uranium-tipped antitank shells during the Gulf War and possible contamination of the environment of Kuwait. It was found that uranium concentrations in the soil samples ranged from 0.3 {mu}g/g to 1.85 {mu}g/g. The average value of 0.7 {mu}g/g was lower than the world average value of 2.1 {mu}g/g for surface soils. Its contribution to the total natural alpha radioactivity (excluding Rn and its short-lived daughters) varied from 1.1% to 14%. The solid fall-out samples showed higher uranium concentration which varied from 0.35 {mu}g/g to 1.73 {mu}/g (average 1.47 {mu}g/g) butmore » its contribution to the gross alpha radioactivity was in the same range, from 1.1 to 13.2%. The difference in the concentration of uranium in suspended air matter samples during the summer of 1993 and the winter of 1994 was found to be 2.0 {mu}g/g and 1.0 {mu}g/g, respectively. The uranium contribution to the natural alpha radioactivity in these samples was in the same range but lower for the winter period. The isotopic ratio of {sup 235}U to {sup 238}U for the measured samples was basically within an experimental error of {+-}0.001, close to the theoretical value of 0.007. The calculated total annual intake of uranium via inhalation for the Kuwait population was 0.07 Bq, e.g., 0.2% of the annual limit on intake. 13 refs., 1 fig., 3 tabs.« less

Selection of entomopathogenic fungi for aphid control.

PubMed

Vu, Van Hanh; Hong, Suk Il; Kim, Keun

2007-12-01

Twelve strains of entomopathogenic fungi such as Lecanicillium lecanii, Paecilomyces farinosus, Beauveria bassiana, Metarhizium anisopliae, Cordyceps scarabaeicola, and Nomuraea rileyi were screened for aphid control. At 25 degrees C and 75% relative humidity (RH), among tested entomopathogenic fungi, L. lecanii 41185 showed the highest virulent pathogenicity for both Myzus persicae and Aphis gossypii, and their control values were both nearly 100% 5 and 2 d after treatment, respectively. Moreover, at an RH of 45% and in a wide temperature range (20-30 degrees C), L. lecanii 41185 also exhibited the highest virulence to M. persicae. The control value of M. persicae and the 50% lethal time (LT50) decreased significantly as the applied conidial concentration increased. The 50% lethal concentration (LC50) of the conidial suspension of this fungus was determined to be 6.55x10(5) conidia/ml. The control values of M. persicae resulting from the application of 1x10(7) and 1x10(8) conidia/ml were nearly the same and were significantly higher than that of 1x10(6) conidia/ml. The tested entomopathogenic fungi grew in a broad temperature range (15-30 degrees C). Lecanicillium strains showed optimum growth at 25 degrees C. The aerial conidia of Lecanicillium strains also could germinate in a broad temperature range (15-30 degrees C) and L. lecanii 41185 was the only strain with conidial germination at 35 degrees C.

PM 2.5 mass concentrations in comparison with aerosol optical depths over the Arabian Sea and Indian Ocean during winter monsoon

NASA Astrophysics Data System (ADS)

Ramachandran, S.

An analysis of PM 2.5 mass concentrations and 0.5 μm aerosol optical depths (AODs) during the Northeast winter monsoon seasons of 1996-2000 is performed and intercompared. AODs are found to show diurnal variations over Coastal India (CI) (west coast) while they are relatively smooth over the Arabian Sea (AS) (5-20°N) and tropical Indian Ocean (TIO) (5°N-20°S). PM 2.5, PM 10 and total mass concentrations show less variations in a day over these oceanic regions. Columnar AODs are found to increase with an increase in the marine boundary layer aerosol concentrations over CI and AS while an opposite trend is seen over TIO. The yearly-mean AODs and mass concentrations are found to increase over CI and AS, over TIO the mass concentrations increased while the AODs decreased during 1996-2000. It is found from the 7-days air back trajectory analyses that at different altitudes air masses can originate from different source regions leading to changes in chemical, physical and optical characteristics of the aerosol between the surface and column. The differences in the surface and columnar measurements could also occur due to changes in the meteorological conditions, wind patterns, in addition to changes in production and subsequently the transport of aerosols. Least-squares fits to the above intercomparison resulted in intercepts of 0.24 and 0.22 over CI and AS indicating that the background AODs over these oceanic regions are higher. An examination of the daily-mean wind speeds and PM 2.5 mass concentrations yielded an index of wind dependence of 0.04 for AS and 0.07 for TIO. The background PM 2.5 mass concentrations are also found to be high at 36 and 25 μg m -3 over AS and TIO, respectively, indicating a stronger influence from the continent. Frequency distribution figures show that 28% of the PM 2.5 values over CI lie in the 60-80 μg m -3 range. Over AS the dominant mode of distribution is 40-60 μg m -3 with a peak value of 42%. Over TIO PM 2.5 values are found to peak in the lower mass bin of 0-20 μg m -3 at 33%. A latitudinal gradient is seen in the peak bin value of PM 2.5 as the ship moves away from the coast. About half the days over CI and 20% over AS and TIO, PM 2.5 values are found unhealthy indicating the influence of anthropogenic pollution and long-range transport of pollutants from the surrounding continental locations across these oceanic regimes. AODs are found to peak in the 0.2-0.4 bin at 52% over CI and 47% over AS. Over AS 32% of the AODs are found to be <0.2. More than 90% of AODs over TIO are <0.2. The feature is different when compared to three maritime locations in the Pacific where 75% or more cases have AODs <0.1. α values are found to peak in the 1.5-2 range over CI at 55% while they peak in the lower range of 1-1.5 at 49% and 26% over AS and TIO, respectively. Over the Pacific and Atlantic Oceans in more than 90% of the cases α was ⩽1.5, indicating that the amount of smaller and larger particles are higher over the Indian Ocean when compared to the Pacific and Atlantic. The spread in PM 2.5 and AOD indicates that it is a challenging task to obtain a good relation without additional inputs on the vertical distribution of aerosols as varied kinds of aerosols from different source regions contribute at different heights over these oceanic regions.

Long-term observations of cloud condensation nuclei in the Amazon rain forest

NASA Astrophysics Data System (ADS)

Pöhlker, Mira L.; Pöhlker, Christopher; Ditas, Florian; Klimach, Thomas; Hrabe de Angelis, Isabella; Brito, Joel; Carbone, Samara; Cheng, Yafang; Martin, Scot T.; Moran-Zuloaga, Daniel; Rose, Diana; Saturno, Jorge; Su, Hang; Thalman, Ryan; Walter, David; Wang, Jian; Barbosa, Henrique; Artaxo, Paulo; Andreae, Meinrat O.; Pöschl, Ulrich

2017-04-01

Size-resolved long-term measurements of atmospheric aerosol and cloud condensation nuclei (CCN) concentrations and hygroscopicity were conducted at the remote Amazon Tall Tower Observatory (ATTO) in the central Amazon Basin over a full seasonal cycle (Mar 2014 - Feb 2015). The measurements provide a climatology of CCN properties characteristic of a remote central Amazonian rain forest site [1,2]. The CCN measurements were continuously cycled through 10 levels of supersaturation (S = 0.11 to 1.10 %) and span the aerosol particle size range from 20 to 245 nm. The particle hygroscopicity exhibits a pronounced size dependence with lower values for the Aitken mode (κAit = 0.14 ± 0.03), higher values for the accumulation mode (κAcc = 0.22 ± 0.05), and an overall mean value of κmean = 0.17 ± 0.06, consistent with high fractions of organic aerosol. The hygroscopicity parameter, κ, exhibits remarkably little temporal variability: no pronounced diurnal cycles, only weak seasonal trends, and few short-term variations during long-range transport events. In contrast, the CCN number concentrations exhibit a pronounced seasonal cycle, tracking the pollution-related seasonality in total aerosol concentration. We find that the variability in the CCN concentrations in the central Amazon is mostly driven by aerosol particle number concentration and size distribution, while variations in aerosol hygroscopicity and chemical composition matter only during a few episodes. For modelling purposes, we compare different approaches of predicting CCN number concentration and present a novel parameterization, which allows accurate CCN predictions based on a small set of input data. In addition, we analyzed the CCN short-term variability in relation to air mass changes as well as aerosol emission and transformation processes. The CCN short term variability is presented for selected case studies, which analyze particularly interesting and characteristic events/conditions in the Amazon region. References: [1] Andreae, M. O., et al. (2015), Atmos. Chem. Phys., 15, 10723-10776. [2] Pöhlker, M. L.., et al. (2016), Atmos. Chem. Phys., 16, 15709-15740.

Investigation of distribution of radioactivity with effects of heavy metals in toothpastes from Penang markets.

PubMed

Salih, Najeba F; Jafri, Zubir M; Jaafar, Mohamad S

2016-12-01

This study was carried out to determine the concentration of 222 Rn, 226 Ra, and 238 U in 25 different toothpastes available in the local market in Penang, Malaysia, using a CR-39 detector. The results showed the maximum concentration of radon/ radium/uranium to be 4197.644 Bq.m -3 , 54.369 Bq.Kgm -1 , and 0.044 ppm in Colgate4; the annual effective dose was found (0.402 mSvy -1 ) in S07. The average concentration of radon (42 %, 3.224 KBq.m -3 ) was higher than the concentration of 214 Po, 218 Po in POS (32 %, 2.415 KBq.m -3 ) and POW (26 %, 1.979 KBq.m -3 ). Also the values of pH of samples ranged from 4.21 (highly acidic) in S04 to 9.97 (highly basic) in S07, with an average of 6.33 which tended towards an acidic behavior; a low or high pH for a long period of time can cause harmful side-effects and enamel erosion. Concentrations of heavy metals varied from the maximum value 56.156 ppm in the Ca elements in the Colgate 4 sample to a minimum value of -0.858 ppm in the Cd elements in Colgate 6 (Ca 56.156 ppm > Cd 51.572 ppm > Zn 41.039 ppm > Mg 11.682 ppm > Pb 11.009 ppm]. Monitoring the accumulation of these metals in toothpaste samples is very important: the average annual effective dose (0.3118 mSvy -1 ) was below the range (3-10 mSvy -1 ) reported by ICRP (1993), and therefore there is no evidence of health problems. Significant strong positive correlations were found (r = 1, Pearson correlation, p < 0.000) in concentration of radon, radium, uranium, annual effective dose, pH, and electrical conductivity.

Water quality of selected lakes in Mount Rainier National Park, Washington with respect to lake acidification

USGS Publications Warehouse

Turney, G.L.; Dion, N.P.; Sumioka, S.S.

1986-01-01

Thirteen lakes in Mount Rainier National Park were evaluated for general chemical characteristics, sensitivity to acidification by acidic precipitation, and degree of existing acidification. The lakes studies were Allen, one of the Chenuis group, Crescent , Crystal, Eleanor, Fan, one of the Golden group, Marsh, Mowich, Mystic, Shriner, and two unnamed lakes. The lakes were sampled in August 1983. Specific conductance values were generally 21 microsiemens/cm at 25 C or less, and dissolved solids concentrations were generally 20 mg/L or less. The major cations were calcium and sodium, and the major anion was bicarbonate. Alkalinity concentrations ranged from 2.1 to 9.0 mg/L in 12 of the lakes. Allen Lake was the exception, having an alkalinity concentration of 27 mg/L. The pH values for all of the lakes ranged from 5.8 to 6.5. In most of the lakes, vertical profiles of temperature, dissolved oxygen, pH, and specific conductance were relatively uniform. In the deeper lakes, temperature decreased with depth and dissolved-oxygen concentrations increased to about 20 feet, remained constant to 80 ft, then decreased with increasing depth. Exceptions to general water quality patterns were observed in three lakes. Allen Lake had a specific conductance value of 58 Microsiemens/cm. The lake of the Golden group was anaerobic at the bottom and had relatively high concentrations of dissolved organic carbon and dissolved metals, and a lower light transmission than the other lakes studied. One of the unnamed lakes had relatively high concentrations of phytoplankton and dissolved organic carbon and relatively low levels of light transmission. Comparisons of lake data to acid-sensitivity thresholds for specific conductance and alkalinity indicated that all of the lakes except Allen would be sensitive to acidic precipitation. The small sizes of the lakes, and their locations in basins of high precipitation and weathering-resistant rock types, enhance their sensitivity. None of the lakes in this study appeared to be presently acidified. (Lantz-PTT)

Concentrations of plutonium and americium in plankton from the western Mediterranean Sea.

PubMed

Sanchez-Cabeza, Joan-Albert; Merino, Juan; Masqué, Pere; Mitchell, Peter I; Vintró, L León; Schell, William R; Cross, Lluïsa; Calbet, Albert

2003-07-20

Understanding the transfer of radionuclides through the food chain leading to man and in particular, the uptake of transuranic nuclides by plankton, is basic to assess the potential radiological risk of the consumption of marine products by man. The main sources of transuranic elements in the Mediterranean Sea in the past were global fallout and the Palomares accident, although at present smaller amounts are released from nuclear establishments in the northwestern region. Plankton from the western Mediterranean Sea was collected and analyzed for plutonium and americium in order to study their biological uptake. The microplankton fractions accounted for approximately 50% of the total plutonium contents in particulate form. At Garrucha (Palomares area), microplankton showed much higher 239,240 Pu activity, indicating the contamination with plutonium from the bottom sediments. Concentration factors were within the range of the values recommended by the International Atomic Energy Agency. Continental shelf mesoplankton was observed to efficiently concentrate transuranics. In open seawaters, concentrations were much lower. We speculate that sediments might play a role in the transfer of transuranics to mesoplankton in coastal waters, although we cannot discard that the difference in species composition may also play a role. In Palomares, both 239,240 Pu and 241Am showed activities five times higher than the mean values observed in continental shelf mesoplankton. As the plutonium isotopic ratios in the contaminated sample were similar to those found in material related to the accident, the contamination was attributed to bomb debris from the Palomares accident. Concentration factors in mesoplankton were also in relatively good agreement with the ranges recommended by IAEA. In the Palomares station the highest concentration factor was observed in the sample that showed predominance of the dynoflagellate Ceratium spp. Mean values of the enrichment factors showed, on average, discrimination rather than enrichment in the primary producer trophic chain.

Vitamin A deficiency and hepatic retinol levels in sea otters, Enhydra lutris.

PubMed

St Leger, Judy A; Righton, Alison L; Nilson, Erika M; Fascetti, Andrea J; Miller, Melissa A; Tuomi, Pamela A; Goertz, Caroline E C; Puschner, Birgit

2011-03-01

Vitamin A deficiency has rarely been reported in captive or free-ranging wildlife species. Necropsy findings in two captively housed southern sea otters (Enhydra lutris nereis) included irregular thickening of the calvaria characterized by diffuse hyperostoses on the internal surface. One animal also had moderate squamous metaplasia of the seromucinous glands of the nose. There was no measurable retinol in the liver of either sea otter. For comparison, hepatic retinol concentration was determined for 23 deceased free-ranging southern and northern (Enhydra lutris kenyoni) sea otters from California and Alaska. Free-ranging otters were found to have similar hepatic retinol concentrations (316 +/- 245 mg/kg wet weight) regardless of their location and subspecies. All of these values were significantly higher than the levels in the affected animals. Consumption of a diet with very low vitamin A concentrations and noncompliance in daily supplementation are hypothesized as the causes of vitamin A deficiency in these two sea otters.

Indirect estimation of emission factors for phosphate surface mining using air dispersion modeling.

PubMed

Tartakovsky, Dmitry; Stern, Eli; Broday, David M

2016-06-15

To date, phosphate surface mining suffers from lack of reliable emission factors. Due to complete absence of data to derive emissions factors, we developed a methodology for estimating them indirectly by studying a range of possible emission factors for surface phosphate mining operations and comparing AERMOD calculated concentrations to concentrations measured around the mine. We applied this approach for the Khneifiss phosphate mine, Syria, and the Al-Hassa and Al-Abyad phosphate mines, Jordan. The work accounts for numerous model unknowns and parameter uncertainties by applying prudent assumptions concerning the parameter values. Our results suggest that the net mining operations (bulldozing, grading and dragline) contribute rather little to ambient TSP concentrations in comparison to phosphate processing and transport. Based on our results, the common practice of deriving the emission rates for phosphate mining operations from the US EPA emission factors for surface coal mining or from the default emission factor of the EEA seems to be reasonable. Yet, since multiple factors affect dispersion from surface phosphate mines, a range of emission factors, rather than only a single value, was found to satisfy the model performance. Copyright © 2016 Elsevier B.V. All rights reserved.

Uranium removal from aqueous solution by coir pith: equilibrium and kinetic studies.

PubMed

Parab, Harshala; Joshi, Shreeram; Shenoy, Niyoti; Verma, Rakesh; Lali, Arvind; Sudersanan, M

2005-07-01

Basic aspects of uranium adsorption by coir pith have been investigated by batch equilibration. The influence of different experimental parameters such as final solution pH, adsorbent dosage, sorption time, temperature and various concentrations of uranium on uptake were evaluated. Maximum uranium adsorption was observed in the pH range 4.0-6.0. The Freundlich and Langmuir adsorption models were used for the mathematical description of the adsorption equilibrium. The equilibrium data fitted well to both the equilibrium models in the studied concentration range of uranium (200-800 mg/l) and temperatures (305-336 K). The coir pith exhibited the highest uptake capacity for uranium at 317 K, at the final solution pH value of 4.3 and at the initial uranium concentration of 800 mg/l. The kinetics of the adsorption process followed a second-order adsorption. The adsorbent used proved to be suitable for removal of uranium from aqueous solutions. 0.2 N HCl was effective in uranium desorption. The results indicated that the naturally abundant coir pith of otherwise nuisance value exhibited considerable potential for application in removal of uranium from aqueous solution.

Intermolecular Interactions and the Viscosity of Highly Concentrated Monoclonal Antibody Solutions.

PubMed

Binabaji, Elaheh; Ma, Junfen; Zydney, Andrew L

2015-09-01

The large increase in viscosity of highly concentrated monoclonal antibody solutions can be challenging for downstream processing, drug formulation, and delivery steps. The objective of this work was to examine the viscosity of highly concentrated solutions of a high purity IgG1 monoclonal antibody over a wide range of protein concentrations, solution pH, ionic strength, and in the presence / absence of different excipients. Experiments were performed with an IgG1 monoclonal antibody provided by Amgen. The steady-state viscosity was evaluated using a Rheometrics strain-controlled rotational rheometer with a concentric cylinder geometry. The viscosity data were well-described by the Mooney equation. The data were analyzed in terms of the antibody virial coefficients obtained from osmotic pressure data evaluated under the same conditions. The viscosity coefficient in the absence of excipients was well correlated with the third osmotic virial coefficient, which has a negative value (corresponding to short range attractive interactions) at the pH and ionic strength examined in this work. These results provide important insights into the effects of intermolecular protein-protein interactions on the behavior of highly concentrated antibody solutions.

The polycyclic aromatic hydrocarbon concentrations in soils in the Region of Valasske Mezirici, the Czech Republic

PubMed Central

2009-01-01

The polycyclic aromatic hydrocarbon (PAH) contamination of urban, agricultural and forest soil samples was investigated from samples obtained in the surroundings of Valasske Mezirici. Valasske Mezirici is a town located in the north-east mountainous part of the Czech Republic, where a coal tar refinery is situated. 16 PAHs listed in the US EPA were investigated. Organic oxidizable carbon was also observed in the forest soils. The PAH concentrations ranged from 0.86-10.84 (with one anomalous value of 35.14) and 7.66-79.39 mg/kg dm in the urban/agricultural and forest soils, respectively. While the PAH levels in the urban/agricultural soils are within the range typically found in industrialized areas, the forest soils showed elevated PAH concentrations compared to other forest soils in Western and Northern Europe. The PAH concentrations and their molecular distribution ratios were studied as functions of the sample location and the meteorological history. The soils from localities at higher altitudes above sea level have the highest PAH concentrations, and the PAH concentrations decrease with increasing distance from the town. PMID:20003407

Urban air pollution in Beijing, China, had no effect on ice nucleating particle concentrations

NASA Astrophysics Data System (ADS)

Wex, H.; Chen, J.; Augustin-Bauditz, S.; Grawe, S.; Pei, X.; Wu, Z.

2017-12-01

In China, and particularly the North China Plain, anthropogenic emissions from coal burning and traffic contribute largely to the atmospheric aerosol loading. In this study, we set out to examine if these particles act as ice nucleating particles (INP). Filter samples were taken in Beijing in Nov. and Dec. of 2016. Chemical particle analysis and determination of the sampled particle mass concentrations were done in Beijing. Parts of the filters were transported to Leipzig (keeping them below -18°C at all times), where cumulative INP concentrations (K(T)) were determined. Measurements of K(T) were done using two freezing-array set-ups similar to the ones introduced in Conen et al. (2012) and in Budke & Koop (2015). Values for K(T) were obtained in a temperature range from roughly -6°C to -25°C. During the sampling periods, phases with both low and high loadings of atmospheric particulate matter occurred, i.e., we were able to sample during clean and polluted conditions. Lowest and highest values for PM2.5 and black carbon mass concentrations varied by more than a factor of 30. However, K(T) at any one temperature did neither correlate with PM2.5 nor with black carbon mass concentrations. But K(T) fell well within the range of atmospheric INP concentrations published in Petters & Wright (2015), derived from precipitation samples originating from a number of different locations in North America and Europe. Also, K(T) published in literature for different locations in China were comparable to the ones we derived in this study, both at urban and rural sites, unless measurements were made during phases of dust events, during which concentrations were more than an order of magnitude higher. Summarizing, in the temperature range down to roughly -25°C, anthropogenically produced aerosol particles in winter time in Beijing did not contribute to atmospheric INP concentrations. It is also worth noting that no deactivation of INP was observed during pollution events, as otherwise particularly low values of K(T) should have been observed during these times. Budke, C., and T. Koop (2015), Atmos. Meas. Tech., 8, 689-703, doi:10.5194/amt-8-689-2015. Conen, F., et al. (2012), Atmos. Meas. Tech., 5, 321-327, doi:10.5194/amt-5-321-2012. Petters, M. D., and T. P. Wright (2015), Geophys. Res. Lett., 42, 8758-8766, doi:10.1002/2015gl065733.

Enrichment of copper and recycling of cyanide from copper-cyanide waste by solvent extraction

NASA Astrophysics Data System (ADS)

Gao, Teng-yue; Liu, Kui-ren; Han, Qing; Xu, Bin-shi

2016-11-01

The enrichment of copper from copper-cyanide wastewater by solvent extraction was investigated using a quaternary ammonium salt as an extractant. The influences of important parameters, e.g., organic-phase components, aqueous pH values, temperature, inorganic anion impurities, CN/Cu molar ratio, and stripping reagents, were examined systematically, and the optimal conditions were determined. The results indicated that copper was effectively concentrated from low-concentration solutions using Aliquat 336 and that the extraction efficiency increased linearly with increasing temperature. The aqueous pH value and concentrations of inorganic anion impurities only weakly affected the extraction process when varied in appropriate ranges. The CN/Cu molar ratio affected the extraction efficiency by changing the distribution of copper-cyanide complexes. The difference in gold leaching efficiency between using raffinate and fresh water was negligible.

Cholinesterase assay for monitoring the kinetics of the JD6. 5 organophosphorus acid anhydrase in detoxification of diisopropylfluorophosphate. Final report, January-June 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeh, H.R.; Cheng, T.C.; DeFrank, J.J.

1992-06-01

In the present studies, cholinesterase was used for monitoring the enzymatic activities of the JD6.5 organophosphorus acid anhydrase. The kinetic data indicated that: (1) the first order of kinetic constants (k) and Vmax values of the enzymatic reactions increased as the concentrations of the enzyme increased; (2) while the half-life (tl/2) of diisopropylfluorophosphate (DFP) hydrolysis decreased as the enzyme concentrations increased; (3) the minimum time required for hydrolysis of 9mM of DFP was 3 min at the concentrations of the enzyme present; Km values of DFP were found to be in range of 5mM; and (4) both MnCl2 and NaClmore » were found to be required for the optimal activity of the enzyme.« less

Non-omnia moriantur-toxicity of mancozeb on dead wood microarthropod fauna.

PubMed

Adamski, Zbigniew; Bloszyk, Jerzy; Bruin, Jan; Ziemnicki, Kazimierz

2007-01-01

The effect of Dithane M-45 (dithiocarbamate fungicide; active substance: mancozeb) was studied on microarthropod fauna inhabiting dead wood. Although the exposure was almost never 100% lethal for the majority of observed taxa, almost all (Mesostigmata, Oribatida, some Uropodina, Actinedida, Collembola and Diplopoda) showed very high correlation between concentration of the fungicide and mortality (r > 0.86). Only Stigmaeidae showed low correlation (r = 0.293). For the majority of taxa LC(50 )values were close to the concentrations used during agrochemical activities in woods. Only Trachytes aegrota showed full susceptibility to the fungicide within the range of recommended field concentrations used in forestry (characterised by the low LC(95 )value). Tolerance of mesostigmatid and oribatid mites was found to differ between juveniles and adults, but not consistently. Related Uropodina species varied in susceptibility to the fungicide.

Air quality assessment by tree bark biomonitoring in urban, industrial and rural environments of the Rhine Valley: PCDD/Fs, PCBs and trace metal evidence.

PubMed

Guéguen, Florence; Stille, Peter; Millet, Maurice

2011-09-01

Tree barks were used as biomonitors to evaluate past atmospheric pollution within and around the industrial zones of Strasbourg (France) and Kehl (Germany) in the Rhine Valley. The here estimated residence time for trace metals, PCBs and PCDD/Fs in tree bark is >10 years. Thus, all pollution observed by tree bark biomonitoring can be older than 10 years. The PCB baseline concentration (sum of seven PCB indicators (Σ(7)PCB(ind))) determined on tree barks from a remote area in the Vosges mountains is 4 ng g(-1) and corresponds to 0.36 × 10(-3)ng toxic equivalent (TEQ) g(-1) for the dioxin-like PCBs (DL-PCBs). The northern Rhine harbor suffered especially from steel plant, waste incinerator and thermal power plant emissions. The polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) concentrations analyzed in tree barks from this industrial area range between 392 and 1420 ng kg(-1) dry-weight (dw) corresponding to 3.9 ng TEQ(PCDD/Fs) kg(-1) to 17.8 ng TEQ(PCDD/Fs) kg(-1), respectively. Highest PCDD/F values of 7.2 ng TEQ kg(-1) to 17.8 ng TEQ kg(-1) have been observed close to and at a distance of <2 km southwest of the chemical waste incinerator. However, very close to this incinerator lowest TEQ dioxin-like PCB (TEQ(DL-PCB)) values of 0.006 ng TEQ g(-1) have been found. On the other hand close to and southwest and northeast of the steel plant the values are comparatively higher and range between 0.011 ng TEQ g(-1) and 0.026 ng TEQ g(-1). However, even stronger Σ(7)PCB(ind) enrichments have been observed at a few places in the city center of Kehl, where ΣDL-PCB values of up to 0.11 ng TEQ g(-1) have been detected. These enrichments, however, are the result of ancient pollutions since recent long-term measurements at the same sites indicate that the atmospheric PCB concentrations are close to baseline. Emissions from an old landfill of waste and/or great fires might have been the reasons of these PCB enrichments. Other urban environments of the cities of Kehl and Strasbourg show significantly lower Σ(7)PCB(ind) concentrations. They suffer especially from road and river traffic and have typically Σ(7)PCB(ind) concentrations ranging from 11 ng g(-1) to 29 ng g(-1). The PCB concentration of 29 ng g(-1) has been found in tree bark close to the railway station of Strasbourg. Nevertheless, the corresponding TEQ(DL-PCB) are low and range between 0.2 × 10(-3) ng TEQ g(-1) and 7 × 10(-3) ng TEQ g(-1). Samples collected near road traffic are enriched in Fe, Sb, Sn and Pb. Cd enrichments were found close to almost all types of industries. Rural environments not far from industrial sites suffered from organic and inorganic pollution. In this case, TEQ(DL-PCB) values may reach up to 58 × 10(-3) ng TEQ g(-1) and the corresponding V, Cr, Co, Ni, and Cd concentrations are comparatively high. Copyright © 2011 Elsevier Ltd. All rights reserved.

[Key pathway of methane production and characteristics of stable carbon isotope of the Tuojia River waterbody.

PubMed

Zhao, Qiang; Lyu, Cheng Wen; Qin, Xiao Bo; Wu, Hong Bao; Wan, Yun Fan; Liao, Yu Lin; Lu, Yan Hong; Wang, Bin; Li, Yong

2018-05-01

This study aimed at exploring the key pathway of methane production and clarifying the composition and distribution of carbon (C) isotopes in the Tuojia River waterbody in Hunan Pro-vince. We estimated CH 4 concentrations and fluxes of four reaches (S 1 , S 2 , S 3 and S 4 ) by a two-layer diffusion model and gas chromatography. The spatial and temporal distribution of CH 4 flux and its relationship with environmental factors were examined. The key pathway of CH 4 production was investigated by stable C isotope method to analyze the distribution characteristics of 13 C isotope (δ 13 C) of water dissolved CH 4 and seston/benthic organic matter. There was significant seasonal variability in water pH, with mean value of (7.27±0.03). The concentration of dissolved oxygen (DO) showed strong seasonal and spatial variations, with the range of 0.43-13.99 mg·L -1 . The maximum value of DO occurred in S 1 and differed significantly in summer and autumin. In addition, DO differed significantly in winter and other seasons in S 2 , S 3 and S 4 . The concentration of dissolved organic carbon (DOC) showed a gradual increasing trend from source to estuary. The highest concentration of DOC (8.32 mg·L -1 ) was found in S 2 , while the lowest was observed in S 1 (0.34 mg·L -1 ). The electrical conductivity (EC) and oxidation-reduction potential (ORP) of water ranged from 17 to 436 μS·cm -1 and from -52.30 to 674.10 mV, respectively, which were significantly different among the four reaches (P＜0.05). Water ammonium nitrogen (NH 4 + -N) and nitrate nitrogen (NO 3 - -N) concentrations were in the ranges of 0.30-1.35 (averaged 0.90±0.10) mg·L -1 and 0.82-2.45 (averaged 1.62±0.16) mg·L -1 , respectively. The dissolved concentration and diffusion flux of CH 4 ranged from 0 to 5.28 μmol·L -1 and from -0.34 to 619.72 μg C·m -2 ·h -1 , respectively, with significant temporal and spatial variations. They showed a similar trend among reaches. Their values were highest in spring, followed by in winter and lowest in summer and autumn. Spatially, the CH 4 concentration and flux followed the order of S 2 >S 3 >S 4 >S 1 . The correlation analysis showed that CH 4 flux was positively correlated with NH 4 + -N and DOC. The pathway of CH 4 production of all reaches was dominated by acetic acid fermentation, while there were obvious differences among the four reaches. The contribution of CH 4 from acetic acid fermentation was greatest (87%) in S 1 , followed by S 4 (81%), S 2 (78%) and S 3 (76%). The mean value of the δ 13 C for dissolved CH 4 , seston organic matter and benthic organic matter was -41.64‰±1.91‰, -14.07‰±1.06‰ and -26.20‰±1.02‰, respectively. There was a positive correlation between the δ 13 C of dissolved CH 4 and benthic organic matter, whereas the δ 13 C value of dissolved CH 4 was negatively correlated with CH 4 flux.

Potential ecotoxicological significance of elevated concentrations of strontium in eggshells of passerine birds

USGS Publications Warehouse

Mora, Miguel A.; Taylor, Robert J.; Brattin, Bryan L.

2007-01-01

We investigated the occurrence and potential ecotoxicological significance of elevated concentrations of strontium (Sr) in eggshells of nine passerine birds from four regions in Arizona. Concentrations of Sr in eggshells ranged from 70 to 1360 µg g−1 dry weight (overall mean  =  684 ± 345 SD µg g−1 dw) for the four regions. 23% of the eggshells had Sr concentrations greater than 1000 µg g−1 dw. To our knowledge, these are among the highest levels of Sr that have been reported in bird eggshells in North America. Of the nine species, Brown-headed Cowbirds (Molothrus ater) had the greatest concentrations of Sr. There was a significant positive correlation between Sr and calcium (Ca), and between barium (Ba) and Ca. Ca, Sr, and Ba interact with each other and can exert similar chemical and pharmacological effects. Mean (n ≥ 3) eggshell∶egg ratios for Sr varied with species and ranged from 6.1∶1 to 40.2∶1; ratios for individual eggs reached 92.7∶1. Mean Sr/Ca values ranged from 1.3 × 10−3 to 3.0 × 10−3 and mean eggshell thickness ranged from 83 ± 6 to 120 ± 9 µm for all species. Eggshell thickness was not significantly correlated with Sr for any species but tended to increase with Sr concentrations. We postulate that high concentrations of Sr in the shell could affect later-stage embryos by possible interference with Ca metabolism and bone growth, resulting in reduced hatching success and potential minor beak deformities.

Comparison of Spectrophotometric Methods for the Determination of Copper in Sugar Cane Spirit.

PubMed

Soares, Sarah Adriana R; Costa, Silvânio Silvério L; Araujo, Rennan Geovanny O; Teixeira, Leonardo Sena Gomes; Dantas, Alailson Falcão

2018-05-01

Three spectrophotometric methods were developed for the determination of copper (Cu) in sugar cane spirit using the chromogenic reagents neocuproine, cuprizone, and bathocuproine. Experimental conditions, such as reagent concentration, reducer concentration, pH, buffer concentration, the order of addition of reagents, and the stability of the complexes, were optimized. The work range was established from 1.0 to 10.0 µg/mL, with correlation coefficients of >0.999 for all three optimized methods. The methods were evaluated regarding accuracy by addition and recovery tests at five concentration levels, and the obtained recoveries ranged from 91 to 105% (n = 3). Precision was expressed as RSD (relative standard deviation), with values ranging from 0.01 to 0.17% (n = 10). The method using the chromogenic reagent cuprizone presented the greatest molar absorptivity, followed by bathocuproine and neocuproine. The methods were applied for the determination of Cu in sugar cane spirit, and the results were compared with a reference method by flame atomic absorption spectrometry (FAAS). Calibration curve solutions for FAAS analysis were prepared in a 40% (v/v) alcohol medium in a range of concentrations from 0.5 up to 5 µg/mL. Measurements for Cu determination were carried out at a wavelength of 324.7 nm. The concentrations obtained for Cu in sugar cane spirit samples from Brazil were between 1.99 and 12.63 µg/mL, and about 75% of the samples presented Cu concentrations above the limit established by Brazilian legislation (5.0 µg/mL or 5.0 mg/L).

Absorbing and scattering aerosols over the source region of biomass burning emissions: Implications in the assessment of optical and radiative properties

NASA Astrophysics Data System (ADS)

Singh, Atinderpal; Srivastava, Rohit; Rastogi, Neeraj; Singh, Darshan

2016-02-01

The current study focuses on the assessment of model simulated optical and radiative properties of aerosols incorporating the measured chemical composition of aerosol samples collected at Patiala during October, 2011-February, 2012. Monthly average mass concentration of PM2.5, elemental carbon (EC), primary organic carbon (POC), water-soluble (WS) and insoluble (INS) aerosols ranged from 120 to 192, 6.2 to 7.2, 20 to 39, 59 to 111 and 35 to 90 μg m-3, respectively. Mass concentration of different components of aerosols was further used for the assessment of optical properties derived from Optical Properties of Aerosols and Clouds (OPAC) model simulations. Microtops based measured aerosol optical depth (AOD500) ranged from 0.47 to 0.62 showing maximum value during November and December, and minimum during February. Ångström exponent (α380-870) remained high (>0.90) throughout the study period except in February (0.74), suggesting predominance of fine mode particles over the study region. The observed ratio of scattering to absorbing aerosols was incorporated in OPAC model simulations and single scattering albedo (SSA at 500 nm) so obtained ranged between 0.80 and 0.92 with relatively low values during the period of extensive biomass burning. In the present study, SBDART based estimated values of aerosol radiative forcing (ARF) at the surface (SRF) and top of the atmosphere (TOA) ranged from -31 to -66 Wm-2 and -2 to -18 W m-2 respectively. The atmospheric ARF, ranged between + 18 and + 58 Wm-2 resulting in the atmospheric heating rate between 0.5 and 1.6 K day-1. These results signify the role of scattering and absorbing aerosols in affecting the magnitude of aerosol forcing.

Breed-specific reference intervals for assessing thyroid function in seven dog breeds.

PubMed

Hegstad-Davies, Rebecca L; Torres, Sheila M F; Sharkey, Leslie C; Gresch, Sarah C; Muñoz-Zanzi, Claudia A; Davies, Peter R

2015-11-01

Thyroxine (T4), free T4 (FT4), and thyrotropin (TSH) concentrations were measured in serum from 693 healthy representatives from 7 dog breeds (Alaskan Malamute, Collie, English Setter, Golden Retriever, Keeshond, Samoyed, or Siberian Husky) to determine whether breed-specific reference intervals (RIs) are warranted. Veterinarians reviewed the health history, performed a physical examination, and approved laboratory data for the enrolled dogs. Many purebred dogs had T4 and FT4 concentrations that were at, or below, the lower limits previously determined for non-breed-specific RIs. Mean concentrations of T4, FT4, and TSH varied significantly among breeds. The range of mean concentration of T4 (19.7 nmol/L [1.53 µg/dL] in English Setters to 29.0 nmol/L [2.25 µg/dL] in Keeshonds) and FT4 (12.6 pmol/L [0.98 ng/dL] in English Setters to 20.2 pmol/L [1.57 ng/dL] in Samoyeds) was considerable. Median TSH values ranged from 6.10 mIU/L (0.07 ng/mL; Alaskan Malamute and Golden Retriever) to 17.6 mIU/L (0.26 ng/mL; Collie). Mean T4 and FT4 concentrations were higher in females. Increasing age was associated with decreasing T4 and FT4, and increasing TSH concentration. The substantial ranges across breeds of measures of central tendency (mean, median) for all hormones indicate that breed-specific RIs are warranted. RIs encompassing the central 95% of reference values for all breeds combined, and for individual breeds, were calculated using nonparametric (TSH) and robust (T4, FT4) methods. Use of breed-specific RIs in combination with careful attention to the potential for pre-analytical and analytical variability in test results will improve thyroid function assessment in these breeds. © 2015 The Author(s).

Hyperglycemia may determine fibrinopeptide A plasma level increase in humans.

PubMed

Ceriello, A; Giugliano, D; Quatraro, A; Dello Russo, P; Marchi, E; Torella, R

1989-12-01

The effects of hyperglycemia on plasma fibrinopeptide A (FPA) levels in normal subjects are reported. An increase of FPA concentration parallel to sustained hyperglycemia was observed; when the glycemia returned to basal values, FPA showed values in normal range. Heparin infusion was able to significantly decrease the hyperglycemia-induced augment of FPA levels. Isovolumic-isotonic NaCl solution infusion produced a slight (NS) increase in FPA levels; however, mild hyperglycemia, achieved by glucagon, was also able to produce a significant increase in FPA concentration. These data demonstrate the direct role of hyperglycemia in conditioning FPA level, and suggest that hyperglycemia, by itself, is a sufficient stimulus to produce thrombin activation in humans.

A quality-assurance assessment for constituents reported by the national atmospheric deposition program and the national trends network

NASA Astrophysics Data System (ADS)

See, Randolph B.; Schroder, LeRoy J.; Willoughby, Timothy C.

A continuing quality-assurance program has been operated by the U.S. Geological Survey to evaluate any bias introduced by routine handling, shipping, and laboratory analyses of wet-deposition samples collected in the National Atmospheric Deposition Program (NADP) and National Trends Network (NTN). Blind-audit samples having a variety of constituent concentrations and values were selected. Only blind-audit samples with constituent concentrations and values less than the 95th-percentile concentration for natural wet-deposition samples were included in the analysis. Of the major ions, there was a significant increase of Ca 2+, Mg 2+, Na 2+, K +, SO 42- and Cl -1 in samples handled according to standard protocols and shipped in NADP/NTN sample-collection buckets. For 1979-1987, graphs of smoothed data showing the estimated contamination in blind-audit samples indicate a decrease in the median concentration and ranges of Ca 2+, Mg 2+ and SO 42- contamination of blind-audit samples shipped in sample-collection buckets. Part of the contamination detected in blind-audit samples can be attributed to contact with the sample-collection bucket and lid; however, additional sources also seem to contaminate the blind-audit sample. Apparent decreases in the magnitude and range of sample contamination may be caused by differences in sample-collection bucket- and lid-washing procedures by the NADP/NTN Central Analytical Laboratory. Although the degree of bias is minimal for most constituents, summaries of the NADP/NTN data base may contain overestimates of Ca 2+, Mg 2+, Na -, K + and SO 42- and Cl - concentrations, and underestimates of H + concentrations.

Heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) in soils of different land uses in Erbil metropolis, Kurdistan Region, Iraq.

PubMed

Amjadian, Keyvan; Sacchi, Elisa; Rastegari Mehr, Meisam

2016-11-01

Urban soil contamination is a growing concern for the potential health impact on the increasing number of people living in these areas. In this study, the concentration, the distribution, the contamination levels, and the role of land use were investigated in Erbil metropolis, the capital of Iraqi Kurdistan. A total of 74 soil samples were collected, treated, and analyzed for their physicochemical properties, and for 7 heavy metals (As, Cd, Cr, Cu, Fe, Pb, and Zn) and 16 PAH contents. High concentrations, especially of Cd, Cu Pb, and Zn, were found. The Geoaccumulation index (I geo ), along with correlation coefficients and principal component analysis (PCA) showed that Cd, Cu, Pb, and Zn have similar behaviors and spatial distribution patterns. Heavy traffic density mainly contributed to the high concentrations of these metals. The total concentration of ∑PAHs ranged from 24.26 to 6129.14 ng/g with a mean of 2296.1 ng/g. The PAH pattern was dominated by 4- and 5-ring PAHs, while diagnostic ratios and PCA indicated that the main sources of PAHs were pyrogenic. The toxic equivalent (TEQ) values ranged from 3.26 to 362.84 ng/g, with higher values in central parts of the city. A statistically significant difference in As, Cd, Cu, Pb, Zn, and ∑PAH concentrations between different land uses was observed. The highest As concentrations were found in agricultural areas while roadside, commercial, and industrial areas had the highest Cd, Cu, Pb, Zn, and ∑PAH contents.

Isotretinoin kinetics after 80 to 320 mg oral doses.

PubMed

Colburn, W A; Gibson, D M

1985-04-01

Twelve healthy male subjects received 80, 160, 240, and 320 mg doses of oral isotretinoin as multiples of 40 mg capsules separated by 2-week washout periods in a randomized, crossover design. Blood samples were drawn at specific times over a 72-hour period after dosing. Blood concentrations of isotretinoin as well as its major metabolite, 4-oxo-isotretinoin, were determined by a specific HPLC method. In addition to the normal laboratory battery of tests, serum triglyceride levels were determined before the first dose and again 72 hours after each of the four doses. Mean (+/- SD) maximum concentrations after 80 to 320 mg doses were 366 +/- 159, 820 +/- 474, 1056 +/- 547, and 981 +/- 381 ng/ml, whereas the respective AUC0-infinity values were 3690 +/- 1280, 7030 +/- 4140, 9780 +/- 6080, and 9040 +/- 2900 ng X hr/ml. The observed apparent elimination t1/2 remained approximately the same (14.7 hours) for each dose. The maximum concentration and AUC values for isotretinoin appear to be dose proportional from 80 to 240 mg but plateau at the 320 mg dose level. Therefore, because isotretinoin blood concentrations may not increase with higher doses in the fasting state, single, oral doses in excess of 240 mg should be used with caution. The data also suggest that elevated triglyceride levels are not a simple function of isotretinoin blood concentrations across the entire study population and dose range studied, but that in subjects with triglyceride levels in excess of the normal range triglyceride levels were positively related to isotretinoin blood concentrations.

A quality-assurance assessment for constituents reported by the National Atmospheric Deposition Program and the National Trends Network

USGS Publications Warehouse

See, R.B.; Schroder, L.J.; Willoughby, T.C.

1989-01-01

A continuing quality-assurance program has been operated by the U.S. Geographical Survey to evaluate any bias introduced by routine handling, shipping, and laboratory analyses of wet-deposition samples collected in the National Atmospheric Deposition Program (NADP) and National Trends Network (NTN). Blind-audit samples having a variety of constituent concentrations and values were selected. Only blind-audit samples with constituent concentrations and values less than the 95th-percentile concentration for natural wet-deposition samples were included in the analysis. Of the major ions, there was a significant increase of Ca2+, Mg2+, K+ SO42+ and Cl- in samples handled according to standard protocols and shipped in NADP/NTN sample-collection buckets. For 1979-1987, graphs of smoothed data showing the estimated contaminations in blind-audit samples indicate a decrease in the median concentration and ranges of Ca2+, Mg2+ and SO42- contamination of blind-audit samples shipped in sample-collection buckets. Part of the contamination detected in blind-audit samples can be attributed to contact with the sample-collection bucket and lid; however, additional sources also seem to contaminate the blind-audit sample. Apparent decreases in the magnitude and range of sample contamination may be caused by differences in sample-collection bucket- and lid-washing procedures by the NADP/NTN Central Analytical Laboratory. Although the degree of bias is minimal for most constituents, summaries of the NADP/NTN data base may contain overestimates of Ca2+, Mg2+, Na-, K+, SO42- and Cl- concentrations, and underestimates of H+ concentrations.

Correlations between homologue concentrations of PCDD/Fs and toxic equivalency values in laboratory-, package boiler-, and field-scale incinerators.

PubMed

Iino, Fukuya; Takasuga, Takumi; Touati, Abderrahmane; Gullett, Brian K

2003-01-01

The toxic equivalency (TEQ) values of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) are predicted with a model based on the homologue concentrations measured from a laboratory-scale reactor (124 data points), a package boiler (61 data points), and operating municipal waste incinerators (114 data points). Regardless of the three scales and types of equipment, the different temperature profiles, sampling emissions and/or solids (fly ash), and the various chemical and physical properties of the fuels, all the PCDF plots showed highly linear correlations (R(2)>0.99). The fitting lines of the reactor and the boiler data were almost linear with slope of unity, whereas the slope of the municipal waste incinerator data was 0.86, which is caused by higher predicted values for samples with high measured TEQ. The strong correlation also implies that each of the 10 toxic PCDF congeners has a constant concentration relative to its respective total homologue concentration despite a wide range of facility types and combustion conditions. The PCDD plots showed significant scatter and poor linearity, which implies that the relative concentration of PCDD TEQ congeners is more sensitive to variations in reaction conditions than that of the PCDF congeners.

The use of atmospheric measurements to constrain model predictions of ozone change from chlorine perturbations

NASA Technical Reports Server (NTRS)

Douglass, Anne R.; Stolarski, Richard S.

1987-01-01

Atmospheric photochemistry models have been used to predict the sensitivity of the ozone layer to various perturbations. These same models also predict concentrations of chemical species in the present day atmosphere which can be compared to observations. Model results for both present day values and sensitivity to perturbation depend upon input data for reaction rates, photodissociation rates, and boundary conditions. A method of combining the results of a Monte Carlo uncertainty analysis with the existing set of present atmospheric species measurements is developed. The method is used to examine the range of values for the sensitivity of ozone to chlorine perturbations that is possible within the currently accepted ranges for input data. It is found that model runs which predict ozone column losses much greater than 10 percent as a result of present fluorocarbon fluxes produce concentrations and column amounts in the present atmosphere which are inconsistent with the measurements for ClO, HCl, NO, NO2, and HNO3.

Assessment of TBT and organic booster biocide contamination in seawater from coastal areas of South Korea.

PubMed

Kim, Nam Sook; Shim, Won Joon; Yim, Un Hyuk; Hong, Sang Hee; Ha, Sung Yong; Han, Gi Myung; Shin, Kyung-Hoon

2014-01-15

Seawater samples from major enclosed bays, fishing ports, and harbors of Korea were analyzed to determine levels of tributyltin (TBT) and booster biocides, which are antifouling agents used as alternatives to TBT. TBT levels were in the range of not detected (nd) to 23.9 ng Sn/L. Diuron and Irgarol 1051, at concentration ranges of 35-1360 ng/L and nd to 14 ng/L, respectively, were the most common alternative biocides present in seawater, with the highest concentrations detected in fishing ports. Hot spots were identified where TBT levels exceeded environmental quality targets even 6 years after a total ban on its use in Korea. Diuron exceeded the UK environmental quality standard (EQS) value in 73% of the fishing port samples, 64% of the major bays, and 42% of the harbors. Irgarol 1051 levels were marginally below the Dutch and UK EQS values at all sites. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mercury accumulation in the surface layers of mountain soils: a case study from the Karkonosze Mountains, Poland.

PubMed

Szopka, Katarzyna; Karczewska, Anna; Kabała, Cezary

2011-06-01

The study was aimed to examine total concentrations and pools of Hg in surface layers of soils in the Karkonosze Mountains, dependent on soil properties and site locality. Soil samples were collected from a litter layer and the layers 0-10 cm and 10-20 cm, at 68 sites belonging to the net of a monitoring system, in two separate areas, and in three altitudinal zones: below 900 m, 900-1100 m, and over 1100 m. Air-borne pollution was the major source of mercury in soils. Hg has accumulated mainly in the litter (where its concentrations were the highest), and in the layer 0-10 cm. Hg concentrations in all samples were in the range 0.04-0.97 mg kg(-1), with mean values 0.38, 0.28, and 0.14 mg kg(-1) for litter and the layers 0-10 cm and 10-20 cm, respectively. The highest Hg concentrations in the litter layer were found in the intermediate altitudinal zone, whereas Hg concentrations in the layer 0-10 cm increased with increasing altitude. Soil quality standard for protected areas (0.50 mg kg(-1)) was exceeded in a few sites. The pools of Hg accumulated in soils were in the range: 0.8-84.8 mg m(-2), with a mean value of 16.5 mg m(-2), and they correlated strongly with the pools of stored organic matter. Copyright © 2011 Elsevier Ltd. All rights reserved.

Levels and spatial distribution of gaseous polychlorinated biphenyls and polychlorinated naphthalenes in the air over the northern South China Sea

NASA Astrophysics Data System (ADS)

Li, Qilu; Xu, Yue; Li, Jun; Pan, Xiaohui; Liu, Xiang; Zhang, Gan

2012-09-01

Monitoring marine persistent organic pollutants (POPs) is important because oceans play a significant role in the cycling of POPs. The South China Sea (SCS) is surrounded by developing countries in Southeast Asia which are centers of e-waste recycling and the ship dismantling industry. In this study, shipboard air samples collected over the SCS between September 6 and 22, 2005 were analyzed for polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs). The levels of ∑12PCBs ranged from 32.3 to 167 pg m-3, with a mean value of 98.4 ± 36.0 pg m-3. Tetra-CBs were the predominant congeners. The concentrations of ∑18PCNs ranged from N.D. to 26.0 pg m-3, with a mean value of 10.5 ± 7.16 pg m-3, and tri-CNs were predominant. The gaseous concentrations of PCBs and PCNs over the SCS were consistent with those over other seas and oceans. Compared with previous studies, it was found that the concentrations of PCBs exhibited an obviously declining trend. The measured PCB and PCN concentrations in the atmosphere over the SCS were influenced by their proximity to source regions and air mass origins. The highest gaseous PCB and PCN concentrations were found at sampling sites adjacent to the continental South China. E-waste recycling, ship dismantling and combustion in South China and some Southeast Asian countries might contribute PCBs and PCNs to the atmosphere of the SCS.

Residence times in river basins as determined by analysis of long-term tritium records

USGS Publications Warehouse

Michel, R.L.

1992-01-01

The US Geological Survey has maintained a network of stations to collect samples for the measurement of tritium concentrations in precipitation and streamflow since the early 1960s. Tritium data from outflow waters of river basins draining 4500-75000 km2 are used to determine average residence times of water within the basins. The basins studied are the Colorado River above Cisco, Utah; the Kissimmee River above Lake Okeechobee, Florida; the Mississippi River above Anoka, Minnesota; the Neuse River above Streets Ferry Bridge near Vanceboro, North Carolina; the Potomac River above Point of Rocks, Maryland; the Sacramento River above Sacramento, California; the Susquehanna River above Harrisburg, Pennsylvania. The basins are modeled with the assumption that the outflow in the river comes from two sources-prompt (within-year) runoff from precipitation, and flow from the long-term reservoirs of the basin. Tritium concentration in the outflow water of the basin is dependent on three factors: (1) tritium concentration in runoff from the long-term reservoir, which depends on the residence time for the reservoir and historical tritium concentrations in precipitation; (2) tritium concentrations in precipitation (the within-year runoff component); (3) relative contributions of flow from the long-term and within-year components. Predicted tritium concentrations for the outflow water in the river basins were calculated for different residence times and for different relative contributions from the two reservoirs. A box model was used to calculate tritium concentrations in the long-term reservoir. Calculated values of outflow tritium concentrations for the basin were regressed against the measured data to obtain a slope as close as possible to 1. These regressions assumed an intercept of zero and were carried out for different values of residence time and reservoir contribution to maximize the fit of modeled versus actual data for all the above rivers. The final slopes of the fitted regression lines ranged from 0.95 to 1.01 (correlation coefficient > 0.96) for the basins studied. Values for the residence time of waters within the basins and average relative contributions of the within-year and long-term reservoirs to outflow were obtained. Values for river basin residence times ranged from 2 years for the Kissimmee River basin to 20 years for the Potomac River basin. The residence times indicate the time scale in which the basin responds to anthropogenic inputs. The modeled tritium concentrations for the basins also furnish input data for urban and agricultural settings where these river waters are used. ?? 1992.

Spectral Optical Properties of the Polluted Atmosphere of Mexico City (Spring-Summer 1992)

NASA Technical Reports Server (NTRS)

Vasilyev, O. B.; Contreras, A. Leyva; Valazquez, A. Muhlia; Peralta-Fabi, R.; Ivlev, L. S.; Kovalenko, A. P.; Vasilyev, A. V.; Jukov, V. M.; Welch, Ronald M.

1995-01-01

A joint Mexican, Russian, and American research effort has been initiated to develop new methods to remotely sense atmospheric parameters using ground-based, aircraft, and satellite observations. As a first step in this program, ground-based spectrophotometric measurements of the direct solar radiation have been obtained for the extremely polluted Mexico City atmosphere for the period of April-June 1992. These observations were made at more than 1300 channels in the spectral range of 0.35-0.95 microns. In the UltraViolet (UV) portions of the spectrum (e.g., 0.35 microns), aerosol optical thicknesses were found to range between 0.6 and 1.2; in the visible portion of the spectrum (e. g., 0.5 microns) they ranged from 0.5 to 0.8; and in the Near-Infrared (NIR) spectra (e.g., 0.85 micron), values of 0.3 - 0.5 were found. Applying a Spectral Optical Depth (SOD) model of tau(lambda) = C + A(lambda(sup -varies as), values of 1.55 less than varies as less than 1.85 were obtained for polluted, cloudless days, with values of 1.25 less than varies as less than 1.60 on days with haze. The aerosol particles in the polluted Mexico City atmosphere were found to be strongly absorbing, with a single-scattering albedo of 0.7 - 0.9 in the UV, 0.6 - 0.8 in the visible portion of the spectrum, and 0.4 - 0.7 in the NIR. These values are possibly consistent with a high soot concentration, contributed both by vehicular traffic and heavy industry. Analysis of the measured aerosol SOD using the optical parameters of an urban aerosol model pemiits the concentration of aerosol particles to be estimated in the vertical column; a maximum value of 3 x 10(exp 9) 1/sq cm was found. This concentration of aerosol particles exceeds that found in most other regions of the globe by at least an order of magnitude. Near the ground the aerosol size distributions measured using an optical particle counter were found to be strongly multimodal.

Linking CDOM spectral absorption to dissolved organic carbon concentrations and loadings in boreal estuaries

NASA Astrophysics Data System (ADS)

Asmala, Eero; Stedmon, Colin A.; Thomas, David N.

2012-10-01

The quantity of chromophoric dissolved organic matter (CDOM) and dissolved organic carbon (DOC) in three Finnish estuaries (Karjaanjoki, Kyrönjoki and Kiiminkijoki) was investigated, with respect to predicting DOC concentrations and loadings from spectral CDOM absorption measurements. Altogether 87 samples were collected from three estuarine transects which were studied in three seasons, covering a salinity range between 0 and 6.8, and DOC concentrations from 1572 μmol l-1 in freshwater to 222 μmol l-1 in coastal waters. CDOM absorption coefficient, aCDOM(375) values followed the trend in DOC concentrations across the salinity gradient and ranged from 1.67 to 33.4 m-1. The link between DOC and CDOM was studied using a range of wavelengths and algorithms. Wavelengths between 250 and 270 nm gave the best predictions with single linear regression. Total dissolved iron was found to influence the prediction in wavelengths above 520 nm. Despite significant seasonal and spatial differences in DOC-CDOM models, a universal relationship was tested with an independent data set and found to be robust. DOC and CDOM yields (loading/catchment area) from the catchments ranged from 1.98 to 5.44 g C m-2 yr-1, and 1.67 to 11.5 aCDOM(375) yr-1, respectively.

Heterotrophic Potential for Amino Acid Uptake in a Naturally Eutrophic Lake1

PubMed Central

Burnison, B. Kent; Morita, Richard Y.

1974-01-01

The uptake of sixteen 14C-labeled amino acids by the indigenous heterotrophic microflora of Upper Klamath Lake, Oregon, was measured using the kinetic approach. The year-long study showed a seasonal variation in the maximum uptake velocity, Vmax, of all the amino acids which was proportional to temperature. The maximum total flux of amino acids by the heterotrophic microflora ranged from 1.2 to 11.9 μmol of C per liter per day (spring to summer). Glutamate, asparagine, aspartate, and serine had the highest Vmax values and were respired to the greatest extent. The percentages of the gross (net + respired) uptake of the amino acids which were respired to CO2 ranged from 2% for leucine to 63% for glutamate. Serine, lysine, and glycine were the most abundant amino acids found in Upper Klamath Lake surface water; at intermediate concentrations were alanine, aspartate, and threonine; and the remaining amino acids were always below 7.5 × 10-8 M (10 μg/liter). The amino acid concentrations determined chemically appear to be the sum of free and adsorbed amino acids, since the values obtained were usually greater than the (Kt + Sn) values obtained by the heterotrophic uptake experiments. PMID:4207581

Concentration dependent refractive index of a binary mixture at high pressure.

PubMed

Croccolo, Fabrizio; Arnaud, Marc-Alexandre; Bégué, Didier; Bataller, Henri

2011-07-21

In the present work binary mixtures of varying concentrations of two miscible hydrocarbons, 1,2,3,4-tetrahydronaphtalene (THN) and n-dodecane (C12), are subjected to increasing pressure up to 50 MPa in order to investigate the dependence of the so-called concentration contrast factor (CF), i.e., (∂n/∂c)(p, T), on pressure level. The refractive index is measured by means of a Mach-Zehnder interferometer. The setup and experimental procedure are validated with different pure fluids in the same pressure range. The refractive index of the THN-C12 mixture is found to vary both over pressure and concentration, and the concentration CF is found to exponentially decrease as the pressure is increased. The measured values of the refractive index and the concentration CFs are compared with values obtained by two different theoretical predictions, the well-known Lorentz-Lorenz formula and an alternative one proposed by Looyenga. While the measured refractive indices agree very well with predictions given by Looyenga, the measured concentration CFs show deviations from the latter of the order of 6% and more than the double from the Lorentz-Lorenz predictions.

Pollutant exposures from natural gas cooking burners: a simulation-based assessment for Southern California.

PubMed

Logue, Jennifer M; Klepeis, Neil E; Lobscheid, Agnes B; Singer, Brett C

2014-01-01

Residential natural gas cooking burners (NGCBs) can emit substantial quantities of pollutants, and they are typically used without venting range hoods. We quantified pollutant concentrations and occupant exposures resulting from NGCB use in California homes. A mass-balance model was applied to estimate time-dependent pollutant concentrations throughout homes in Southern California and the exposure concentrations experienced by individual occupants. We estimated nitrogen dioxide (NO2), carbon monoxide (CO), and formaldehyde (HCHO) concentrations for 1 week each in summer and winter for a representative sample of Southern California homes. The model simulated pollutant emissions from NGCBs as well as NO2 and CO entry from outdoors, dilution throughout the home, and removal by ventilation and deposition. Residence characteristics and outdoor concentrations of NO2 and CO were obtained from available databases. We inferred ventilation rates, occupancy patterns, and burner use from household characteristics. We also explored proximity to the burner(s) and the benefits of using venting range hoods. Replicate model executions using independently generated sets of stochastic variable values yielded estimated pollutant concentration distributions with geometric means varying by <10%. The simulation model estimated that-in homes using NGCBs without coincident use of venting range hoods-62%, 9%, and 53% of occupants are routinely exposed to NO2, CO, and HCHO levels that exceed acute health-based standards and guidelines. NGCB use increased the sample median of the highest simulated 1-hr indoor concentrations by 100, 3,000, and 20 ppb for NO2, CO, and HCHO, respectively. Reducing pollutant exposures from NGCBs should be a public health priority. Simulation results suggest that regular use of even moderately effective venting range hoods would dramatically reduce the percentage of homes in which concentrations exceed health-based standards.

Distribution and Source of Polycyclic Aromatic Hydrocarbons (PAHs) in Water Dissolved Phase, Suspended Particulate Matter and Sediment from Weihe River in Northwest China

PubMed Central

Chen, Yuyun; Jia, Rui; Yang, Shengke

2015-01-01

Weihe River is a typical river located in the arid and semi-arid regions of Northwest China. In this study, the distribution and sources of 16 polycyclic aromatic hydrocarbons (PAHs) in Weihe River were investigated. The concentrations of ∑PAHs ranged from 351 to 4427 ng/L with a mean value of 835.4 ng/L in water dissolved phase (WDP), from 3557 ng/L to 147,907 ng/L with a mean value of 20,780 ng /L in suspended particulate matter (SPM), and from 362 to 15,667 ng/g dry weight (dw) with a mean value of 2000 ng/g dw in sediment, respectively. The concentrations of PAHs in Weihe River were higher compared with other rivers in the world. In both WDP and sediment, the highest concentrations of ∑PAHs were observed in the middle reach, while the lowest concentrations of ∑PAHs were found in the lower reach. For SPM, however, the PAHs concentrations in the lower reach were highest and the PAHs concentrations in the upper reach were lowest. The ratios of anthracene/(anthracene + phenanthrene) and fluoranthene/(fluoranthene + pyrene) reflected a pattern of both pyrolytic and petrogenic input of PAHs in Weihe River. The potential ecosystem risk assessment indicated that harmful biological impairments occur frequently in Weihe River. PMID:26561824

Effects of locust bean gum and mono- and diglyceride concentrations on particle size and melting rates of ice cream.

PubMed

Cropper, S L; Kocaoglu-Vurma, N A; Tharp, B W; Harper, W J

2013-06-01

The objective of this study was to determine how varying concentrations of the stabilizer, locust bean gum (LBG), and different levels of the emulsifier, mono- and diglycerides (MDGs), influenced fat aggregation and melting characteristics of ice cream. Ice creams were made containing MDGs and LBG singly and in combination at concentrations ranging between 0.0% to 0.14% and 0.0% to 0.23%, respectively. Particle size analysis, conducted on both the mixes and ice cream, and melting rate testing on the ice cream were used to determine fat aggregation. No significant differences (P < 0.05) were found between particle size values for experimental ice cream mixes. However, higher concentrations of both LBG and MDG in the ice creams resulted in values that were larger than the control. This study also found an increase in the particle size values when MDG levels were held constant and LBG amounts were increased in the ice cream. Ice creams with higher concentrations of MDG and LBG together had the greatest difference in the rate of melting than the control. The melting rate decreased with increasing LBG concentrations at constant MDG levels. These results illustrated that fat aggregation may not only be affected by emulsifiers, but that stabilizers may play a role in contributing to the destabilization of fat globules. © 2013 Institute of Food Technologists®

Reagentless and calibrationless silicate measurement in oceanic waters.

PubMed

Giraud, William; Lesven, Ludovic; Jońca, Justyna; Barus, Carole; Gourdal, Margaux; Thouron, Danièle; Garçon, Véronique; Comtat, Maurice

2012-08-15

Determination of silicate concentration in seawater without addition of liquid reagents was the key prerequisite for developing an autonomous in situ electrochemical silicate sensor (Lacombe et al., 2007) [11]. The present challenge is to address the issue of calibrationless determination. To achieve such an objective, we chose chronoamperometry performed successively on planar microelectrode (ME) and ultramicroelectrode (UME) among the various possibilities. This analytical method allows estimating simultaneously the diffusion coefficient and the concentration of the studied species. Results obtained with ferrocyanide are in excellent agreement with values of the imposed concentration and diffusion coefficient found in the literature. For the silicate reagentless method, successive chronoamperometric measurements have been performed using a pair of gold disk electrodes for both UME and ME. Our calibrationless method was tested with different concentrations of silicate in artificial seawater from 55 to 140×10(-6) mol L(-1). The average value obtained for the diffusion coefficient of the silicomolybdic complex is 2.2±0.4×10(-6) cm(2) s(-1), consistent with diffusion coefficient values of molecules in liquid media. Good results were observed when comparing known concentration of silicate with experimentally derived ones. Further work is underway to explore silicate determination within the lower range of oceanic silicate concentration, down to 0.1×10(-6) mol L(-1). Copyright © 2012 Elsevier B.V. All rights reserved.

Magnetic studies of nickel ferrite nanoparticles prepared by sol-gel technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anumol, C. N.; Chithra, M.; Sahoo, Subasa C., E-mail: subasa@cukerala.ac.in

2016-05-06

Ni-ferrite nanoparticles were synthesized by sol–gel technique by varying the solvent concentration. X-ray diffraction studies confirmed the phase purity in the samples. The lattice constant and grain size were found to be in the range of 0.833-0.834 nm and 14-26 nm respectively. There was no systematic variation in magnetization value with the solvent concentration and grain size. The highest magnetization, remanence and coercivity values of 60 emu/g, 12 emu/g and 180 Oe respectively were observed at 300K in the present study for the sample prepared in 75ml of solvent. The observed magnetization value is 20% higher than the bulk value of 50more » emu/g. The magnetization, coercivity and remanence values were enhanced at 60K compared to those at 300K. The observed high magnetization value in the nanoparticles can be explained on the basis of modified cation distribution in the lattice sites. The enhanced magnetic properties at 60K may be understood due to the reduced thermal fluctuation and increased anisotropy at low temperature.« less

Radioactivity level and toxic elemental concentration in groundwater at Dei-Dei and Kubwa areas of Abuja, north-central Nigeria

NASA Astrophysics Data System (ADS)

Maxwell, O.; Wagiran, H.; Lee, S. K.; Embong, Z.; Ugwuoke, P. E.

2015-02-01

The activity concentrations of uranium and toxic elements in Dei-Dei borehole, Kubwa borehole, Water Board and hand-dug well water samples in Abuja area were measured using inductively coupled plasma mass spectrometry (ICP-MS) system. The results obtained were used to calculate human radiological risk over lifetime consumption by the inhabitants in the area. The activity concentrations of 238U in all the water supplies for drinking ranges from 0.849 mBq L-1 to 2.699 mBq L-1 with the highest value of 2.699 mBq L-1 noted at Dei-Dei borehole whereas the lowest value of 0.849 mBq L-1 was noted in Kubwa borehole. The highest annual effective dose from natural 238U in all the water samples was found in Dei-Dei borehole with a value of 8.9×10-5 mSv y-1 whereas the lowest value was noted in Kubwa borehole with a value of 2.8×10-5 mSv y-1. The radiological risks for cancer mortality were found distinctly low, with the highest value of 1.01×10-7 reported at Dei-Dei borehole compared to Kubwa borehole with a value of 3.01×10-8. The cancer morbidity risk was noted higher in Dei-Dei borehole with a value of 1.55×10-7 whereas lower value of 4.88×10-9 was reported in Kubwa borehole. The chemical toxicity risk of 238U in drinking water over a lifetime consumption has a value of 0.006 μg kg-1 day-1 in Dei-Dei borehole whereas lower value of 0.002 μg kg-1 day-1 was found in Kubwa borehole. Measured lead (Pb) and chromium (Cr) concentrations reported higher in Water Board compared to Dei-Dei and Kubwa borehole samples. Significantly, this study inferred that the 238U concentrations originate from granitic strata of the tectonic events in the area; thus, there was a trend of diffusion towards north to south and re-deposition towards Dei-Dei area.

Concentrations and co-occurrence correlations of 88 volatile organic compounds (VOCs) in the ambient air of 13 semi-rural to urban locations in the United States

USGS Publications Warehouse

Pankow, J.F.; Luo, W.; Bender, D.A.; Isabelle, L.M.; Hollingsworth, J.S.; Chen, C.; Asher, W.E.; Zogorski, J.S.

2003-01-01

The ambient air concentrations of 88 volatile organic compounds were determined in samples taken at 13 semi-rural to urban locations in Maine, Massachusetts, New Jersey, Pennsylvania, Ohio, Illinois, Louisiana, and California. The sampling periods ranged from 7 to 29 months, yielding a large data set with a total of 23,191 individual air concentration values, some of which were designated "ND" (not detected). For each compound at each sampling site, the air concentrations (ca, ppbV) are reported in terms of means, medians, and means of the detected values. The analytical method utilized adsorption/thermal desorption with air-sampling cartridges. The analytes included numerous halogenated alkanes, halogenated alkenes, ethers, alcohols, nitriles, esters, ketones, aromatics, a disulfide, and a furan. At some sites, the air concentrations of the gasoline-related aromatic compounds and the gasoline additive methyl tert-butyl ether were seasonally dependent, with concentrations that maximized in the winter. For each site studied here, the concentrations of some compounds were highly correlated one with another (e.g., the BTEX group (benzene, toluene, ethylbenzene, and the xylenes). Other aromatic compounds were also all generally correlated with one another, while the concentrations of other compound pairs were not correlated (e.g., benzene was not correlated with CFC-12). The concentrations found for the BTEX group were generally lower than the values that have been previously reported for urbanized and industrialized areas of other nations. ?? 2003 Elsevier Ltd. All rights reserved.

Effects of cadmium on bioaccumulation and biochemical stress response in rice (Oryza sativa L.).

PubMed

Xie, Pan-pan; Deng, Juan-wei; Zhang, Hui-min; Ma, You-hua; Cao, De-ju; Ma, Ru-xiao; Liu, Ren-jing; Liu, Cheng; Liang, Yue-gan

2015-12-01

This study investigated the effects of various Cd concentrations on the bioaccumulation, antioxidative defense, and stress responses of rice (Oryza sativa L.). The distribution characteristics of Cd in rice were in the following order: roots>stems>grains. The bioconcentration factor values of Cd increased at concentrations lower than 3.00 mg Cd/kg and approximately decreased to a constant value at concentrations higher than 3.00 mg Cd/kg. Rice showed a higher Cd accumulation potential at low Cd concentrations than at high Cd concentrations. The Freundlich isotherm model described well the adsorption isotherms of Cd in rice roots. The biosorption mechanism of rice roots was determined to be cooperative adsorption. The malondialdehyde (MDA) content increased at a concentration range of 0.00-5.00 mg/L, indicating the enhancement of lipid peroxidation. By contrast, the MDA content slightly decreased at concentrations higher than 5.00 mg/L. Peroxidase (POD) activity exhibited active response to oxidative stress at concentrations lower than 5.00 mg/L but was inhibited at concentrations higher than 5.00 mg/L. The response to Cd stress of the N-H, O-H and C-O functional groups in rice shoots was observed via Fourier transform infrared spectroscopy. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of acetic acid, ethanol, and SO(2) on the removal of volatile acidity from acidic wines by two Saccharomyces cerevisiae commercial strains.

PubMed

Vilela-Moura, Alice; Schuller, Dorit; Mendes-Faia, Arlete; Côrte-Real, Manuela

2010-07-01

Herein, we report the influence of different combinations of initial concentration of acetic acid and ethanol on the removal of acetic acid from acidic wines by two commercial Saccharomyces cerevisiae strains S26 and S29. Both strains reduced the volatile acidity of an acidic wine (1.0 gl(-1) acetic acid and 11% (v/v) ethanol) by 78% and 48%, respectively. Acetic acid removal by strains S26 and S29 was associated with a decrease in ethanol concentration of 0.7 and 1.2% (v/v), respectively. Strain S26 revealed better removal efficiency due to its higher tolerance to stress factors imposed by acidic wines. Sulfur dioxide (SO(2)) in the concentration range 95-170 mg l(-1)inhibits the ability of both strains to reduce the volatile acidity of the acidic wine used under our experimental conditions. Therefore, deacidification should be carried out either in wines stabilized by filtration or in wines with SO(2)concentrations up to 70 mg l(-1). Deacidification of wines with the better performing strain S26 was associated with changes in the concentration of volatile compounds. The most pronounced increase was observed for isoamyl acetate (banana) and ethyl hexanoate (apple, pineapple), with an 18- and 25-fold increment, respectively, to values above the detection threshold. The acetaldehyde concentration of the deacidified wine was 2.3 times higher, and may have a detrimental effect on the wine aroma. Moreover, deacidification led to increased fatty acids concentration, but still within the range of values described for spontaneous fermentations, and with apparently no negative impact on the organoleptical properties.

Field-based evaluation of semipermeable membrane devices (SPMDs) as passive air samplers of polyaromatic hydrocarbons (PAHs)

USGS Publications Warehouse

Bartkow, M.E.; Huckins, J.N.; Muller, J.F.

2004-01-01

Semipermeable membrane devices (SPMDs) have been used as passive air samplers of semivolatile organic compounds in a range of studies. However, due to a lack of calibration data for polyaromatic hydrocarbons (PAHs), SPMD data have not been used to estimate air concentrations of target PAHs. In this study, SPMDs were deployed for 32 days at two sites in a major metropolitan area in Australia. High-volume active sampling systems (HiVol) were co-deployed at both sites. Using the HiVol air concentration data from one site, SPMD sampling rates were measured for 12 US EPA Priority Pollutant PAHs and then these values were used to determine air concentrations at the second site from SPMD concentrations. Air concentrations were also measured at the second site with co-deployed HiVols to validate the SPMD results. PAHs mostly associated with the vapour phase (Fluorene to Pyrene) dominated both the HiVol and passive air samples. Reproducibility between replicate passive samplers was satisfactory (CV<20%) for the majority of compounds. Sampling rates ranged between 0.6 and 6.1 m3 d-1. SPMD-based air concentrations were calculated at the second site for each compound using these sampling rates and the differences between SPMD-derived air concentrations and those measured using a HiVol were, on average, within a factor of 1.5. The dominant processes for the uptake of PAHs by SPMDs were also assessed. Using the SPMD method described herein, estimates of particulate sorbed airborne PAHs with five rings or greater were within 1.8-fold of HiVol measured values. ?? 2004 Elsevier Ltd. All rights reserved.

Profile of Some Trace Elements in the Liver of Camels, Sheep, and Goats in the Sudan

PubMed Central

Ibrahim, Ibrahim Abdullah; Shamat, Ali Mahmoud; Hussien, Mohammed Osman; El Hussein, Abdel Rahim Mohammed

2013-01-01

One hundred camels (Camelus dromedaries) and fifty sheep and goats being adult, male, and apparently healthy field animals were studied to provide data regarding the normal values of some hepatic trace elements. Liver samples were collected during postmortem examination, digested, and analyzed for Cu, Zn, Fe, Co, and Mn using atomic absorption spectrophotometry. The results showed that the differences in mean liver concentrations of Cu, Zn, Fe, and Co between camels, sheep, and goats were statistically significant (P < 0.05). Hepatic Cu, Fe, and Co concentrations were higher in camels than in sheep and goats. All liver samples were adequate for Fe and Co, whereas only camel liver was adequate for Cu. In camels, hepatic Zn concentration was inadequately lower than that in sheep and goats. No difference in Mn concentration was detected between camels, sheep, and goats. All liver samples were inadequate compared to free-ranging herbivores. In camels, significant correlation (r 2 = −0.207, P value = 0.04) was detected between Zn and Co, whereas in sheep significant correlation (r 2 = −0.444, P value = 0.026) was detected between Zn and Mn. No significant correlation between trace elements was detected in goats. PMID:26464909

Proposal to evaluate the use of ERTS-1 imagery in mapping and managing soil and range resources in the Sand Hills region of Nebraska

NASA Technical Reports Server (NTRS)

Drew, J. V. (Principal Investigator)

1974-01-01

The author has identified the following significant results. Increase in radiance values is directly related to decrease in vegetative biomass, though not in a linear manner. Should the relationship hold true over an entire growing season, this would allow an extremely rapid evaluation of range condition. Computer access by remote terminal would allow production of this type of range condition evaluation in near real time, which is essential if grazing practice decisions are to be made based on satellite imagery acquisition. Negating the manipulation of photographic products appears to be the logical way to provide satellite imagery data to the user in near real time. There appears to be a direct linear relationship between radiance values of bands 4 and 5 and increase in total inorganic ions (6 ions) of lakes in the Sand hills region. Consistent ion concentration of lakes during the year could allow their radiance values to serve as a means of equating radiance values from image to image.

Bioaccumulation and elimination kinetics of hydroxylated polybrominated diphenyl ethers (2'-OH-BDE68 and 4-OH-BDE90) and their distribution pattern in common carp (Cyprinus carpio).

PubMed

Zhao, Hongxia; Zhang, Guolong; Liu, Sisi; Qu, Baocheng; Wang, Yanli; Hu, Dingfei; Jiang, Jingqiu; Quan, Xie; Chen, Jingwen

2014-06-15

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have attracted wide concerns due to their toxicities and universal presence in wildlife and humans. The relatively high Kow values of OH-PBDEs imply these compounds may have a significant bioaccumulation potential, but so far, the existing data provide little information regarding the kinetics of uptake and depuration in any organisms. Here we exposed common carps separately to two OH-PBDEs, 2'-OH-BDE68 and 4-OH-BDE90, for 30 days (d) in a flow-through system, followed by a 60-d depuration period in clean water to investigate compound-specific bioaccumulation and tissue distribution. Two OH-PBDEs could accumulate in common carp, and the high concentration was observed in liver or kidney. The uptake rates (k1) of two OH-PBDEs ranged from 0.15 to 21.3 d(-1) in fish, and the elimination rates (k2) ranged from 0.027 to 0.075 d(-1), which leaded to their BCF values in 4.8-299.2 ranges. Half-lives ranged from 9.2 d to 25.6 d. The exposure concentration significantly affected BCF values but didn't change their relative compositions in liver, kidney and muscle after a long exposure time. To our knowledge, this is the first study to systematically assess uptake, depuration kinetics and tissue distribution for OH-PBDEs via a controlled experimental animal model. Copyright © 2014 Elsevier B.V. All rights reserved.

Water quality characterization and mathematical modeling of dissolved oxygen in the East and West Ponds, Jamaica Bay Wildlife Refuge.

PubMed

Maillacheruvu, Krishnanand; Roy, D; Tanacredi, J

2003-09-01

The current study was undertaken to characterize the East and West Ponds and develop a mathematical model of the effects of nutrient and BOD loading on dissolved oxygen (DO) concentrations in these ponds. The model predicted that both ponds will recover adequately given the average expected range of nutrient and BOD loading due to waste from surface runoff and migratory birds. The predicted dissolved oxygen levels in both ponds were greater than 5.0 mg/L, and were supported by DO levels in the field which were typically above 5.0 mg/L during the period of this study. The model predicted a steady-state NBOD concentration of 12.0-14.0 mg/L in the East Pond, compared to an average measured value of 3.73 mg/L in 1994 and an average measured value of 12.51 mg/L in a 1996-97 study. The model predicted that the NBOD concentration in the West Pond would be under 3.0 mg/L compared to the average measured values of 7.50 mg/L in 1997, and 8.51 mg/L in 1994. The model predicted that phosphorus (as PO4(3-)) concentration in the East Pond will approach 4.2 mg/L in 4 months, compared to measured average value of 2.01 mg/L in a 1994 study. The model predicted that phosphorus concentration in the West Pond will approach 1.00 mg/L, compared to a measured average phosphorus (as PO4(3-)) concentration of 1.57 mg/L in a 1994 study.

Analysis of concentric and eccentric contractions in biceps brachii muscles using surface electromyography signals and multifractal analysis.

PubMed

Marri, Kiran; Swaminathan, Ramakrishnan

2016-06-23

Muscle contractions can be categorized into isometric, isotonic (concentric and eccentric) and isokinetic contractions. The eccentric contractions are very effective for promoting muscle hypertrophy and produce larger forces when compared to the concentric or isometric contractions. Surface electromyography signals are widely used for analyzing muscle activities. These signals are nonstationary, nonlinear and exhibit self-similar multifractal behavior. The research on surface electromyography signals using multifractal analysis is not well established for concentric and eccentric contractions. In this study, an attempt has been made to analyze the concentric and eccentric contractions associated with biceps brachii muscles using surface electromyography signals and multifractal detrended moving average algorithm. Surface electromyography signals were recorded from 20 healthy individuals while performing a single curl exercise. The preprocessed signals were divided into concentric and eccentric cycles and in turn divided into phases based on range of motion: lower (0°-90°) and upper (>90°). The segments of surface electromyography signal were subjected to multifractal detrended moving average algorithm, and multifractal features such as strength of multifractality, peak exponent value, maximum exponent and exponent index were extracted in addition to conventional linear features such as root mean square and median frequency. The results show that surface electromyography signals exhibit multifractal behavior in both concentric and eccentric cycles. The mean strength of multifractality increased by 15% in eccentric contraction compared to concentric contraction. The lowest and highest exponent index values are observed in the upper concentric and lower eccentric contractions, respectively. The multifractal features are observed to be helpful in differentiating surface electromyography signals along the range of motion as compared to root mean square and median frequency. It appears that these multifractal features extracted from the concentric and eccentric contractions can be useful in the assessment of surface electromyography signals in sports medicine and training and also in rehabilitation programs. © IMechE 2016.

Tetragonal Chicken Egg White Lysozyme Solubility in Sodium Chloride Solutions

NASA Technical Reports Server (NTRS)

Forsythe, Elizabeth L.; Judge, Russell A.; Pusey, Marc L.

1998-01-01

The solubility of chicken egg white lysozyme, crystallized in the tetragonal form was measured in sodium chloride solutions from 1.6 to 30.7 C, using a miniature column solubility apparatus. Sodium chloride solution concentrations ranged from 1 to 7% (w/v). The solutions were buffered with 0.1 M sodium acetate buffer with the solubility being measured at pH values in 0.2 pH unit increments in the range pH 4.0 to 5.4, with data also included at pH 4.5. Lysozyme solubility was found to increase with increases in temperature and decreasing salt concentration. Solution pH has a varied and unpredictable effect on solubility.

The chemical composition of fogs and intercepted clouds in the United States

NASA Astrophysics Data System (ADS)

Collett, Jeffrey L.; Bator, Aaron; Sherman, D. Eli; Moore, Katharine F.; Hoag, Katherine J.; Demoz, Belay B.; Rao, Xin; Reilly, Jill E.

Over the past decade, the chemical compositions of fogs and intercepted clouds have been investigated at more than a dozen locations across the United States. Sampling sites have been located in the northeast, southeast, Rocky Mountain, and west coast regions of the US. They include both pristine and heavily polluted locations. Frontal/orographic clouds (warm and supercooled), intercepted coastal stratiform clouds, and radiation fogs have all been examined. Sample pH values range from below 3 to above 7. Major ions also exhibit a wide concentration range, with clouds at some locations exhibiting high sea salt concentrations, while composition at other locations is dominated by ammonium and sulfate or nitrate.

Determination of lead and cadmium concentration limits in agricultural soil and municipal solid waste compost through an approach of zero tolerance to food contamination.

PubMed

Saha, Jayanta Kumar; Panwar, N R; Singh, M V

2010-09-01

Cadmium and lead are important environmental pollutants with high toxicity to animals and human. Soils, though have considerable metal immobilizing capability, can contaminate food chain via plants grown upon them when their built-up occurs to a large extent. Present experiment was carried out with the objective of quantifying the limits of Pb and Cd loading in soil for the purpose of preventing food chain contamination beyond background concentration levels. Two separate sets of pot experiment were carried out for these two heavy metals with graded levels of application doses of Pb at 0.4-150 mg/kg and Cd at 0.02-20 mg/kg to an acidic light textured alluvial soil. Spinach crop was grown for 50 days on these treated soils after a stabilization period of 2 months. Upper limit of background concentration levels (C(ul)) of these metals were calculated through statistical approach from the heavy metals concentration values in leaves of spinach crop grown in farmers' fields. Lead and Cd concentration limits in soil were calculated by dividing C(ul) with uptake response slope obtained from the pot experiment. Cumulative loading limits (concentration limits in soil minus contents in uncontaminated soil) for the experimental soil were estimated to be 170 kg Pb/ha and 0.8 kg Cd/ha. Based on certain assumptions on application rate and computed cumulative loading limit values, maximum permissible Pb and Cd concentration values in municipal solid waste (MSW) compost were proposed as 170 mg Pb/kg and 0.8 mg Cd/kg, respectively. In view of these limiting values, about 56% and 47% of the MSW compost samples from different cities are found to contain Pb and Cd in the safe range.

Evaluation of Parameter Uncertainty Reduction in Groundwater Flow Modeling Using Multiple Environmental Tracers

NASA Astrophysics Data System (ADS)

Arnold, B. W.; Gardner, P.

2013-12-01

Calibration of groundwater flow models for the purpose of evaluating flow and aquifer heterogeneity typically uses observations of hydraulic head in wells and appropriate boundary conditions. Environmental tracers have a wide variety of decay rates and input signals in recharge, resulting in a potentially broad source of additional information to constrain flow rates and heterogeneity. A numerical study was conducted to evaluate the reduction in uncertainty during model calibration using observations of various environmental tracers and combinations of tracers. A synthetic data set was constructed by simulating steady groundwater flow and transient tracer transport in a high-resolution, 2-D aquifer with heterogeneous permeability and porosity using the PFLOTRAN software code. Data on pressure and tracer concentration were extracted at well locations and then used as observations for automated calibration of a flow and transport model using the pilot point method and the PEST code. Optimization runs were performed to estimate parameter values of permeability at 30 pilot points in the model domain for cases using 42 observations of: 1) pressure, 2) pressure and CFC11 concentrations, 3) pressure and Ar-39 concentrations, and 4) pressure, CFC11, Ar-39, tritium, and He-3 concentrations. Results show significantly lower uncertainty, as indicated by the 95% linear confidence intervals, in permeability values at the pilot points for cases including observations of environmental tracer concentrations. The average linear uncertainty range for permeability at the pilot points using pressure observations alone is 4.6 orders of magnitude, using pressure and CFC11 concentrations is 1.6 orders of magnitude, using pressure and Ar-39 concentrations is 0.9 order of magnitude, and using pressure, CFC11, Ar-39, tritium, and He-3 concentrations is 1.0 order of magnitude. Data on Ar-39 concentrations result in the greatest parameter uncertainty reduction because its half-life of 269 years is similar to the range of transport times (hundreds to thousands of years) in the heterogeneous synthetic aquifer domain. The slightly higher uncertainty range for the case using all of the environmental tracers simultaneously is probably due to structural errors in the model introduced by the pilot point regularization scheme. It is concluded that maximum information and uncertainty reduction for constraining a groundwater flow model is obtained using an environmental tracer whose half-life is well matched to the range of transport times through the groundwater flow system. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Transfer of copper, lead and zinc in soil-grass ecosystem in aspect of soils properties, in Poland.

PubMed

Niesiobędzka, Krystyna

2012-04-01

The total metal concentrations in soil samples from polluted area (roadside soils) ranged from 13.87 to 195.76 mg/kg for Cu; 13.56-310.17 mg/kg for Pb and 18.43-894.11 mg/kg for Zn and they were, respectively about 5, 2 and 13 times above the corresponding values in soil samples from country area. The mean values of EDTA-extractable concentrations in soil samples at unpolluted sites were: 2.47 mg/kg for Cu, 6.33 mg/kg for Pb and 4.94 mg/kg for Zn. The highest concentrations of Cu, Pb and Zn in grass were measured in soils from polluted area. Higher values of proportions of EDTA-extractable metals (24% for Cu, 40% for Pb and 38% for Zn) indicate that anthropogenic metals were more mobile and bioavailable than the same metals in soils from unpolluted area (20, 16 and 20% for Cu, Pb and Zn, respectively). The availability of Cu, Pb and Zn are affected by soil properties such as pH, organic matter content and cation exchange capacity. Correlation between the EDTA-extractable forms concentrations of metals and the total concentration in the various soils was observed. The coefficients of determination (R(2)) varied between 0.809 for Cu; 0,709 for Pb and 0.930 for Zn in polluted soils and they are higher than corresponding values in unpolluted soils.

Orthogonal design on range hood with air curtain and its effects on kitchen environment.

PubMed

Liu, Xiaomin; Wang, Xing; Xi, Guang

2014-01-01

Conventional range hoods cannot effectively prevent the oil fumes containing cooking-induced harmful material from escaping into the kitchen Air curtains and guide plates have been used in range hoods to reduce the escape of airborne emissions and heat, thereby improving the kitchen environment and the cook's degree of comfort. In this article, numerical simulations are used to study the effects of the jet velocity of an air curtain, the jet angle of the air curtain, the width of the jet slot, the area of the guide plate, and the exhaust rate of the range hood on the perceived temperature, the perceived concentration of oil fumes, the release temperature of oil fumes, and the concentration of escaped oil fumes in a kitchen. The orthogonal experiment results show that the exhaust rate of the range hood is the main factor influencing the fumes concentration and the temperature distribution in the kitchen. For the range hood examined in the present study, the optimum values of the exhaust rate, the jet velocity of the air curtain, the jet angle of the air curtain, the width of the jet slot, and the area of the guide plate are 10.5 m(3)/min, 1.5 m/s, -5°, 4 mm, and 0.22 m(2), respectively, based on the results of the parametric study. In addition, the velocity field, temperature field, and oil fumes concentration field in the kitchen using the proposed range hood with the air curtain and guide plate are analyzed for those parameters. The study's results provide significant information needed for improving the kitchen environment.

Polarimetry as a tool for the study of solutions of chiral solutes.

PubMed

Orlova, Anna V; Andrade, Renato R; da Silva, Clarissa O; Zinin, Alexander I; Kononov, Leonid O

2014-01-13

Optical rotation of aqueous solutions of D-levoglucosan was studied experimentally in the 0.03-4.0 mol L(-1) concentration range and a nonlinear concentration dependence of specific optical rotation (SR) was revealed. Discontinuities observed in the concentration plot of SR (at 0.1, 0.3, 0.5, 1.0, and 2.0 mol L(-1)) are well correlated with those found by static and dynamic light scattering and identify concentration ranges in which different solution domains (supramers) may exist. The average SR experimental value for a D-levoglucosan aqueous solution ([α]D(28) -58.5±8.7 deg dm(-1) cm(-3) g(-1)) was found to be in good agreement with values obtained by theoretical calculation (TD-DFT/GIAO) of SR for 15 different conformers revealed by conformational sampling at the PCM/B3LYP/6-311++G(2d,2p)//B3LYP/6-31+G(d,p) level, which were shown to be strongly affected by the solvation microenvironment (0, 1, 2, and 3 explicit solvent molecules considered) due to local geometrical changes induced in the solute molecule. This exceptionally high sensitivity of SR makes polarimetry a unique method capable of sensing changes in the structure of supramers detected in this study. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of triclosan on reproduction, DNA damage and heat shock protein gene expression of the earthworm Eisenia fetida.

PubMed

Lin, Dasong; Li, Ye; Zhou, Qixing; Xu, Yingming; Wang, Di

2014-12-01

Triclosan (TCS) is released into the terrestrial environment via the application of sewage sludge and reclaimed water to agricultural land. More attention has been paid to its effect on non-target soil organisms. In the present study, chronic toxic effects of TCS on earthworms at a wide range of concentrations were investigated. The reproduction, DNA damage, and expression levels of heat shock protein (Hsp70) gene of earthworms were studied as toxicity endpoints. The results showed that the reproduction of earthworms were significantly reduced (p < 0.05) after exposure to the concentrations ranges from 50 to 300 mg kg(-1), with a half-maximal effective concentration (EC50) of 142.11 mg kg(-1). DNA damage, detected by the comet assay, was observed and there was a clear significant (R(2) = 0.941) relationship between TCS concentrations and DNA damage, with the EC50 value of 8.85 mg kg(-1). The expression levels of Hsp70 gene of earthworms were found to be up-regulated under the experimental conditions. The expression level of hsp70 gene increased, up to about 2.28 folds that in the control at 50 mg kg(-1). The EC50 value based on the Hsp70 biomarker was 1.79 mg kg(-1). Thus, among the three toxicity endpoints, the Hsp70 gene was more sensitive to TCS in soil.

Biomonitoring of 30 trace elements in urine of children and adults by ICP-MS.

PubMed

Heitland, Peter; Köster, Helmut D

2006-03-01

The paper provides physicians and clinical chemists with statistical data (concentration ranges, geometric mean values, selected percentiles, etc.) about 30 urinary trace elements in order to determine whether people have trace element deficiencies or have been exposed to higher elemental concentrations. Morning urine samples of 72 children and 87 adults from two geographical areas of Germany were collected and the elements Li, Be, V, Cr, Mn, Ni, Co, Cu, Zn, Ga, As, Se, Rb, Sr, Mo, Rh, Pd, Ag, Cd, In, Sn, Sb, Cs, Ba, Pt, Au, Pb, Tl, Bi and U were determined by inductively coupled plasma mass spectrometry (ICP-MS) with a new octopole based collision/reaction cell. The urine samples were analysed directly after a simple 1/5 (V/V) dilution with deionised water and nitric acid. Information on exposure conditions of all human subjects were collected by questionnaire-based interviews. The described concentration data down to the ng/l range are very useful for the formulation of reference values. For some elements either new data are described (e.g., for V, Ga, In, Bi, Rh, Mn) or differences to earlier studies were found (e.g., for Be, As). For other elements (e.g., Sb, Se, Mo, Ba, Cu, Zn, Li) our results are in good correlation with previous studies and also complemented with urinary trace element concentrations for children.

Estimation of PCB content in agricultural soils associated with long-term fertilization with organic waste.

PubMed

Antolín-Rodríguez, Juan M; Sánchez-Báscones, Mercedes; Martín-Ramos, Pablo; Bravo-Sánchez, Carmen T; Martín-Gil, Jesús

2016-06-01

Polychlorinated biphenyl (PCB) pollution related to the use of organic waste as fertilizers in agricultural soils is a cause of major concern. In the study presented herein, PCB concentration was studied through a field trial conducted in two agricultural soils in the province of Palencia (Spain) over a 4-year period, assessing the impact of irrigation and of different types of organic waste materials. The amounts of organic waste added to the soil were calculated according to the nitrogen needs of the crop, and the concentration of PCBs was determined before and after the application of the organic waste. The resulting persistence of the total PCB content in the agricultural soils, compared with the PCB concentration in the original soils, ranged from 27% to 90%, with the lowest value corresponding to irrigated soils treated with municipal solid waste compost (MSWC) and the highest value to non-irrigated soils treated with composted sewage sludge (CSS). An estimate of the PCB content in agricultural soils after the application of organic waste materials until year 2050 was obtained, resulting in a value below 5 ng·g(-1), considered a background value for soils in sites far away from potential pollution sources.

[Harmonization of TSH Measurements.

PubMed

Takeoka, Keiko; Hidaka, Yoh; Hishinuma, Akira; Ikeda, Katsuyoshi; Okubo, Shigeo; Tsuchiya, Tatsuyuki; Hashiguchi, Teruto; Furuta, Koh; Hotta, Taeko; Matsushita, Kazuyuki; Matsumoto, Hiroyuki; Murakami, Masami; Maekawa, Masato

2016-05-01

The measured concentration of thyroid stimulating hormone (TSH) differs depending on the reagents used. Harmonization of TSH is crucial because the decision limits are described in current clinical practice guide- lines as absolute values, e.g. 2.5 mIU/L in early pregnancy. In this study, we tried to harmonize the report- ed concentrations of TSH using the all-procedure trimmed mean. TSH was measured in 146 serum samples, with values ranging from 0.01 to 18.8 mIU/L, using 4 immunoassays. The concentration of TSH was highest with E test TOSOH and lowest with LUMIPULSE. The concentrations with each reagent were recalculated with the following formulas: E test TOSOH 0.855x-0.014; ECLusys 0.993x+0.079; ARCHITECT 1.041x- 0.010; and LUMIPULSE 1.096x-0.015. Recalculation eliminated the between-assay discrepancy. These formulas may be used until harmonization of TSH is achieved by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC).

Phytoremediation of stable Cs from solutions by Calendula alata, Amaranthus chlorostachys and Chenopodium album.

PubMed

Moogouei, Roxana; Borghei, Mehdi; Arjmandi, Reza

2011-10-01

Uptake rate of (133)Cs, at three different concentrations of CsCl, by Calendula alata, Amaranthus chlorostachys and Chenopodium album plants grown outdoors was studied. These plants grow abundantly in semi-arid regions and their varieties exist in many parts of the world. When exposed to lowest Cs concentration 68 percent Cs was remediated by Chenopodium album.(133)Cs accumulation in shoots of Amaranthus chlorostachys reached its highest value of 2146.2 mg kg(-1) at a (133)Cs supply level of 3.95 mg l(-1) of feed solution. The highest concentration ratio value was 4.89 for Amaranthus chlorostachys, whereas for the other tests it ranged from 0.74 to 3.33. Furthermore uptake of (133)Cs by all three species increased with increasing metal concentrations. The results also indicated that hydroponically grown Calendula alata, Amaranthus chlorostachys and Chenopodium album could be used as potential candidate plants for phytoremediation of solutions contaminated with Cs. Copyright © 2011 Elsevier Inc. All rights reserved.

Paleoceanographic conditions at approximately 20 and 70 ka recorded in Kikaithyris hanzawai (Brachiopoda) shells

NASA Astrophysics Data System (ADS)

Takizawa, Mamoru; Takayanagi, Hideko; Yamamoto, Koshi; Abe, Osamu; Sasaki, Keiichi; Iryu, Yasufumi

2017-10-01

The δ13C and δ18O values of fossil brachiopod shells have been widely used as paleoenvironmental proxies. In this study, we investigated intrashell and intraspecific variations in the isotopic and minor element concentrations of well-preserved shells of the brachiopod Kikaithyris hanzawai (Yabe) from the last glacial period (∼20 ka [Last Glacial Maximum; LGM] and ∼70 ka [Marine Isotope Stage 4; MIS4]), collected in the Central Ryukyus, and used these data to estimate the paleoceanographic conditions (seawater temperature, concentration of dissolved inorganic carbon [DIC], and δ13C value of DIC [δ13CDIC]). The δ13C and δ18O profiles along the maximum growth axis, obtained from the inner shell surface, show three distinct intervals, corresponding to changes in shell morphology. These results suggest that the bulk isotopic compositions of brachiopods with complex shell morphologies are unsuitable for paleoenvironmental reconstructions. Nevertheless, there exists a specific shell portion with relatively small intrashell and intraspecific variations. The past seawater temperatures derived from the δ18O values of this portion are consistent with the alkenone- and planktic foraminiferal Mg/Ca-based past seawater temperatures reported in previous studies. The past δ13CDIC values estimated from the δ13C values of the specific shell portion are within the range of the past δ13CDIC values calculated from known atmospheric and oceanographic parameters. The past DIC concentrations reconstructed from the brachiopod-based δ13CDIC values are lower than the present concentrations in the East China Sea, which can be explained by low partial pressure of CO2 during the last glacial period. These results indicate that the δ13C and δ18O values obtained from K. hanzawai shells are potential paleoenvironmental indicators. The intrashell and intraspecific variations in the K. hanzawai shells are different for each minor element. Some anomalously high Mn and Fe concentrations in the shells are probably caused by metabolic factor(s), not by meteoric diagenesis. This suggests that the minor element concentrations are useful but not perfect for distinguishing diagenetically altered and unaltered portions of the shells of K. hanzawai in the studied succession.

Metastable and equilibrium phase diagrams of unconjugated bilirubin IXα as functions of pH in model bile systems: Implications for pigment gallstone formation.

PubMed

Berman, Marvin D; Carey, Martin C

2015-01-01

Metastable and equilibrium phase diagrams for unconjugated bilirubin IXα (UCB) in bile are yet to be determined for understanding the physical chemistry of pigment gallstone formation. Also, UCB is a molecule of considerable biomedical importance because it is a potent antioxidant and an inhibitor of atherogenesis. We employed principally a titrimetric approach to obtain metastable and equilibrium UCB solubilities in model bile systems composed of taurine-conjugated bile salts, egg yolk lecithin (mixed long-chain phosphatidylcholines), and cholesterol as functions of total lipid concentration, biliary pH values, and CaCl2 plus NaCl concentrations. Metastable and equilibrium precipitation pH values were obtained, and average pKa values of the two carboxyl groups of UCB were calculated. Added lecithin and increased temperature decreased UCB solubility markedly, whereas increases in bile salt concentrations and molar levels of urea augmented solubility. A wide range of NaCl and cholesterol concentrations resulted in no specific effects, whereas added CaCl2 produced large decreases in UCB solubilities at alkaline pH values only. UV-visible absorption spectra were consistent with both hydrophobic and hydrophilic interactions between UCB and bile salts that were strongly influenced by pH. Reliable literature values for UCB compositions of native gallbladder biles revealed that biles from hemolytic mice and humans with black pigment gallstones are markedly supersaturated with UCB and exhibit more acidic pH values, whereas biles from nonstone control animals and patients with cholesterol gallstone are unsaturated with UCB. Copyright © 2015 the American Physiological Society.

Metastable and equilibrium phase diagrams of unconjugated bilirubin IXα as functions of pH in model bile systems: Implications for pigment gallstone formation

PubMed Central

Berman, Marvin D.

2014-01-01

Metastable and equilibrium phase diagrams for unconjugated bilirubin IXα (UCB) in bile are yet to be determined for understanding the physical chemistry of pigment gallstone formation. Also, UCB is a molecule of considerable biomedical importance because it is a potent antioxidant and an inhibitor of atherogenesis. We employed principally a titrimetric approach to obtain metastable and equilibrium UCB solubilities in model bile systems composed of taurine-conjugated bile salts, egg yolk lecithin (mixed long-chain phosphatidylcholines), and cholesterol as functions of total lipid concentration, biliary pH values, and CaCl2 plus NaCl concentrations. Metastable and equilibrium precipitation pH values were obtained, and average pKa values of the two carboxyl groups of UCB were calculated. Added lecithin and increased temperature decreased UCB solubility markedly, whereas increases in bile salt concentrations and molar levels of urea augmented solubility. A wide range of NaCl and cholesterol concentrations resulted in no specific effects, whereas added CaCl2 produced large decreases in UCB solubilities at alkaline pH values only. UV-visible absorption spectra were consistent with both hydrophobic and hydrophilic interactions between UCB and bile salts that were strongly influenced by pH. Reliable literature values for UCB compositions of native gallbladder biles revealed that biles from hemolytic mice and humans with black pigment gallstones are markedly supersaturated with UCB and exhibit more acidic pH values, whereas biles from nonstone control animals and patients with cholesterol gallstone are unsaturated with UCB. PMID:25359538

A transient dopamine signal encodes subjective value and causally influences demand in an economic context

PubMed Central

Schelp, Scott A.; Pultorak, Katherine J.; Rakowski, Dylan R.; Gomez, Devan M.; Krzystyniak, Gregory; Das, Raibatak; Oleson, Erik B.

2017-01-01

The mesolimbic dopamine system is strongly implicated in motivational processes. Currently accepted theories suggest that transient mesolimbic dopamine release events energize reward seeking and encode reward value. During the pursuit of reward, critical associations are formed between the reward and cues that predict its availability. Conditioned by these experiences, dopamine neurons begin to fire upon the earliest presentation of a cue, and again at the receipt of reward. The resulting dopamine concentration scales proportionally to the value of the reward. In this study, we used a behavioral economics approach to quantify how transient dopamine release events scale with price and causally alter price sensitivity. We presented sucrose to rats across a range of prices and modeled the resulting demand curves to estimate price sensitivity. Using fast-scan cyclic voltammetry, we determined that the concentration of accumbal dopamine time-locked to cue presentation decreased with price. These data confirm and extend the notion that dopamine release events originating in the ventral tegmental area encode subjective value. Using optogenetics to augment dopamine concentration, we found that enhancing dopamine release at cue made demand more sensitive to price and decreased dopamine concentration at reward delivery. From these observations, we infer that value is decreased because of a negative reward prediction error (i.e., the animal receives less than expected). Conversely, enhancing dopamine at reward made demand less sensitive to price. We attribute this finding to a positive reward prediction error, whereby the animal perceives they received a better value than anticipated. PMID:29109253

Establishing traceability of photometric absorbance values for accurate measurements of the haemoglobin concentration in blood

NASA Astrophysics Data System (ADS)

Witt, K.; Wolf, H. U.; Heuck, C.; Kammel, M.; Kummrow, A.; Neukammer, J.

2013-10-01

Haemoglobin concentration in blood is one of the most frequently measured analytes in laboratory medicine. Reference and routine methods for the determination of the haemoglobin concentration in blood are based on the conversion of haeme, haemoglobin and haemiglobin species into uniform end products. The total haemoglobin concentration in blood is measured using the absorbance of the reaction products. Traceable absorbance measurement values on the highest metrological level are a prerequisite for the calibration and evaluation of procedures with respect to their suitability for routine measurements and their potential as reference measurement procedures. For this purpose, we describe a procedure to establish traceability of spectral absorbance measurements for the haemiglobincyanide (HiCN) method and for the alkaline haematin detergent (AHD) method. The latter is characterized by a higher stability of the reaction product. In addition, the toxic hazard of cyanide, which binds to the iron ion of the haem group and thus inhibits the oxygen transport, is avoided. Traceability is established at different wavelengths by applying total least-squares analysis to derive the conventional quantity values for the absorbance from the measured values. Extrapolation and interpolation are applied to get access to the spectral regions required to characterize the Q-absorption bands of the HiCN and AHD methods, respectively. For absorbance values between 0.3 and 1.8, the contributions of absorbance measurements to the total expanded uncertainties (95% level of confidence) of absorbance measurements range from 1% to 0.4%.

Stability of mercury concentration measurements in archived soil and peat samples

USGS Publications Warehouse

Navrátil, Tomáš; Burns, Douglas; Nováková, Tereza; Kaňa, Jiří; Rohovec, Jan; Roll, Michal; Ettler, Vojtěch

2018-01-01

Archived soil samples can provide important information on the history of environmental contamination and by comparison with recently collected samples, temporal trends can be inferred. Little previous work has addressed whether mercury (Hg) concentrations in soil samples are stable with long-term storage under standard laboratory conditions. In this study, we have re-analyzed using cold vapor atomic adsorption spectroscopy a set of archived soil samples that ranged from relatively pristine mountainous sites to a polluted site near a non-ferrous metal smelter with a wide range of Hg concentrations (6 - 6485 µg kg-1). Samples included organic and mineral soils and peats with a carbon content that ranged from 0.2 to 47.7%. Soil samples were stored in polyethylene bags or bottles and held in laboratory rooms where temperature was not kept to a constant value. Mercury concentrations in four subsets of samples were originally measured in 2000, 2005, 2006 and 2007, and re-analyzed in 2017, i.e. after 17, 12, 11 and 10 years of storage. Statistical analyses of either separated or lumped data yielded no significant differences between the original and current Hg concentrations. Based on these analyses, we show that archived soil and peat samples can be used to evaluate historical soil mercury contamination.

Plasma hormonal and electrolyte alterations in cycling buffaloes ( Bubalus bubalis) during hot summer months

NASA Astrophysics Data System (ADS)

Singh, Narinder; Chaudhary, K. C.

1992-09-01

Plasma levels of progesterone, prolactin, luteinizing hormone, and electrolytes were monitored by radioimmunoassay in ten cycling buffaloes maintained at Punjab Agricultural University, Ludhiana during the hot summer months of June July. The plasma progesterone concentration ranged from 0.28±0.04 to 3.09±0.03 ng/ml at various stages of the oestrous cycle. Prolactin values ranged from 319±23 to 371±25 ng/ml and LH levels from 0.95±0.05 to 1.35±0.08 ng/ml. Concentrations differed significantly ( P⩽0.05) at various stages of the cycle. Levels of electrolytes, viz. Ca+ +, Na+ and K+, were well within the normal range. The high levels of prolactin, progesterone and LH during the hot summer were assessed in relation to poor reproductive efficiency in buffaloes.

Comparison of aldehyde emissions simulation with FTIR measurements in the exhaust of a spark ignition engine fueled by ethanol

NASA Astrophysics Data System (ADS)

Zarante, Paola Helena Barros; Sodré, José Ricardo

2018-07-01

This work presents a numerical simulation model for aldehyde formation and exhaust emissions from ethanol-fueled spark ignition engines. The aldehyde simulation model was developed using FORTRAN software, with the input data obtained from the dedicated engine cycle simulation software AVL BOOST. The model calculates formaldehyde and acetaldehyde concentrations from post-flame partial oxidation of methane, ethane and unburned ethanol. The calculated values were compared with experimental data obtained from a mid-size sedan powered by a 1.4-l spark ignition engine, tested on a chassis dynamometer. Exhaust aldehyde concentrations were determined using a Fourier Transform Infrared (FTIR) Spectroscopy analyzer. In general, the results demonstrate that the concentrations of aldehydes and the source elements increased with engine speed and exhaust gas temperature. The measured acetaldehyde concentrations showed values from 3 to 6 times higher than formaldehyde in the range studied. The model could predict reasonably well the qualitative experimental trends, with the quantitative results showing a maximum discrepancy of 39% for acetaldehyde concentration and 21 ppm for exhaust formaldehyde.

Comparison of aldehyde emissions simulation with FTIR measurements in the exhaust of a spark ignition engine fueled by ethanol

NASA Astrophysics Data System (ADS)

Zarante, Paola Helena Barros; Sodré, José Ricardo

2018-02-01

This work presents a numerical simulation model for aldehyde formation and exhaust emissions from ethanol-fueled spark ignition engines. The aldehyde simulation model was developed using FORTRAN software, with the input data obtained from the dedicated engine cycle simulation software AVL BOOST. The model calculates formaldehyde and acetaldehyde concentrations from post-flame partial oxidation of methane, ethane and unburned ethanol. The calculated values were compared with experimental data obtained from a mid-size sedan powered by a 1.4-l spark ignition engine, tested on a chassis dynamometer. Exhaust aldehyde concentrations were determined using a Fourier Transform Infrared (FTIR) Spectroscopy analyzer. In general, the results demonstrate that the concentrations of aldehydes and the source elements increased with engine speed and exhaust gas temperature. The measured acetaldehyde concentrations showed values from 3 to 6 times higher than formaldehyde in the range studied. The model could predict reasonably well the qualitative experimental trends, with the quantitative results showing a maximum discrepancy of 39% for acetaldehyde concentration and 21 ppm for exhaust formaldehyde.

An Evaluation of Molybdenum Toxicity to the Oligochaete, Tubifex tubifex, and Early-Life Stages of Brown Trout, Salmo trutta.

PubMed

Lucas, Brett T; Quinteros, Claudio; Burnett-Seidel, Charlene; Elphick, James R

2017-06-01

Limited data are available describing the aquatic toxicity of molybdenum in freshwater environments, making it difficult to assess the aquatic risk to freshwater organisms. In order to increase available information on the aquatic toxicity of molybdenum, a 96-h LC50 test with the oligochaete Tubifex tubifex and an 85-day development test using brown trout, Salmo trutta, were conducted. The T. tubifex test resulted in an LC50 value of 2782 mg/L. No adverse effects were observed on brown trout survival or length in the concentrations tested, however an IC10 value for growth (wet weight) was determined to be 202 mg/L. Whole body fish tissue concentrations for molybdenum increased in all treatment concentrations tested, although bioconcentration factors decreased at greater exposure concentrations, and ranged from 0.13 at an exposure concentration of 20 mg/L to 0.04 at an exposure of 1247 mg/L. A body burden of 26.0 mg/kg was associated with reduced wet weight.

Development of a fast and simple test system for the semiquantitative protein detection in cerebrospinal liquids based on gold nanoparticles.

PubMed

Göbel, Gero; Lange, Robert; Hollidt, Jörg-Michael; Lisdat, Fred

2016-01-01

The fast and simple detection of increased protein concentrations in cerebrospinal liquids is preferable in the emergency medicine and it can help to avoid unnecessary laboratory work by an early classification of neurological diseases. Here a test system is developed which is based on the electrostatic interaction between negatively charged gold nanoparticles and proteins at pH values around 5. The test system can be adjusted in such a way that protein/nanoparticles aggregates are formed leading to a red-shift in the absorption spectrum of the nanoparticles suspension. At concentrations above 500 mg/l the color of the suspension changes from red via violet toward blue in a rather small concentration range from 500 to 1000 mg/l. Furthermore the influence of various parameters such as gold nanoparticle concentration, pH value and varying ion concentration in the sample on the test system is examined. Finally cerebrospinal liquids of a larger number of patients have been analyzed. Copyright © 2015 Elsevier B.V. All rights reserved.

Arsenic and other trace elements in groundwater and human urine in Ha Nam province, the Northern Vietnam: contamination characteristics and risk assessment.

PubMed

Pham, Long Hai; Nguyen, Hue Thi; Van Tran, Cuong; Nguyen, Ha Manh; Nguyen, Tung Hoang; Tu, Minh Binh

2017-06-01

The contamination characteristics of arsenic and other trace elements in groundwater and the potential risks of arsenic from the groundwater were investigated. Elevated contamination of arsenic, barium and manganese was observed in tube-well water of two villages (Chuyen Ngoai and Chau Giang) in Ha Nam province in the Northern Vietnam. Concentrations of As in the groundwater ranged from 12.8 to 884 µg/L with mean values in Chuyen Ngoai and Chau Giang were 614.7 and 160.1 µg/L, respectively. About 83 % of these samples contained As concentrations exceeding WHO drinking water guideline of 10 μg/L. The mean values of Mn and Ba in groundwater from Chuyen Ngoai and Chau Giang were 300 and 657 μg/L and 650 and 468 μg/L, respectively. The mean value of Ba concentration in groundwater in both Chuyen Ngoai and Chau Giang was about 22 % of the samples exceeded the WHO guideline (700 µg/L). Arsenic concentrations in human urine of residents from Chuyen Ngoai and Chau Giang were the range from 8.6 to 458 µg/L. The mean values of Mn and Ba in human urine of local people from Chuyen Ngoai were 46.9 and 62.8 μg/L, respectively, while those in people from Chau Giang were 25.9 and 45.9 μg/L, respectively. The average daily dose from ingesting arsenic for consuming both untreated and treated groundwater is from 0.02 to 11.5 and 0.003 to 1.6 μg/kg day, respectively. Approximately, 57 % of the families using treated groundwater and 64 % of the families using untreated groundwater could be affected by elevated arsenic exposure.

Accumulation and distributions of {sup 137}Cs in fresh water snail Pila ampullacea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suseno, Heny, E-mail: henis@batan.go.id

2014-10-24

Pila ampullacea are found in tropical freshwaters of Indonesia. This snail exhibit several characteristics of ideal indicator organisms in order to understand the bioaccumulation of {sup 137}Cs. Biokinetic experiment was performaced in aquaria system and under influenced of concentration K{sup +} in water. The result of experiment shown that Under difference K{sup +} concentration in water, Pila ampullacea have capability to accumulated {sup 137}Cs with CF value range 8.95 to 12.52 ml.g{sup −1}. Both uptake and depuration rate were influenced by concentration of K{sup +} in water.

Measurements of radon concentrations in spa waters in Amasya, Turkey.

PubMed

Oner, F; Yigitoglu, I; Yalim, H A

2013-12-01

Radon concentration measurements were performed in four spas used for therapy, drinking and irrigation purposes in the Amasya basin in Turkey, during a period of time between January 2009 and May 2010. The measurements were done using commercially available WG-1001 Vacuum Water Degassing System and the AB-5R Radiation Monitor manufactured by Pylon Electronics. The observed radon concentration values ranged from 0.11 to 0.71 Bq L⁻¹. Effective doses from inhalation of radon released from spa waters have been estimated between 0.28 and 1.78 μSv y⁻¹ .

Preliminary assessment of the velocity pump reaction turbine as a geothermal total-flow expander

NASA Astrophysics Data System (ADS)

Demuth, O. J.

1984-06-01

The velocity pump reaction turbine (VPRT) was evaluated as a total flow expander in a geothermal-electric conversion cycle. Values of geofluid effectiveness of VPRT systems were estimated for conditions consisting of: a 360(F) geothermal resource, 60 F wet-bulb ambient temperature, zero and 0.003 mass concentrations of dissolved noncondensible gas in the geofluid, 100 and 120 F condensing temperatures, and engine efficiencies ranging from 0.4 to 1.0. Achievable engine efficiencies were estimated to range from 0.77, with plant geofluid effectiveness values ranging as high as 9.5 watt hr-lbm geofluid for the 360 F resource temperature. This value is competitive with magnitudes of geofluid effectiveness projected for advanced binary plants, and is on the order of 40% higher than estimates for dual-flash steam and other total flow systems reviewed. Because of its potentially high performance and relative simplicity, the VPRT system appears to warrant further investigation toward its use in a well-head geothermal plant.

Effect of various refining processes for Kenaf Bast non-wood pulp fibers suspensions on heat transfer coefficient in circular pipe heat exchanger

NASA Astrophysics Data System (ADS)

Ahmed, Syed Muzamil; Kazi, S. N.; Khan, Ghulamullah; Sadri, Rad; Dahari, Mahidzal; Zubir, M. N. M.; Sayuti, M.; Ahmad, Pervaiz; Ibrahim, Rushdan

2018-03-01

Heat transfer coefficients were obtained for a range of non-wood kenaf bast pulp fiber suspensions flowing through a circular pipe heat exchanger test loop. The data were produced over a selected temperature and range of flow rates from the flow loop. It was found that the magnitude of the heat transfer coefficient of a fiber suspension is dependent on characteristics, concentration and pulping method of fiber. It was observed that at low concentration and high flow rates, the heat transfer coefficient values of suspensions were observed higher than that of the heat transfer coefficient values of water, on the other hand the heat transfer coefficient values of suspensions decreases at low flow rates and with the increase of their concentration. The heat transfer were affected by varying fiber characteristics, such as fiber length, fiber flexibility, fiber chemical and mechanical treatment as well as different pulping methods used to liberate the fibers. Heat transfer coefficient was decreased with the increase of fiber flexibility which was also observed by previous researchers. In the present work, the characteristics of fibers are correlated with the heat transfer coefficient of suspensions of the fibers. Deviations in fiber properties can be monitored from the flowing fiber suspensions by measuring heat transfer coefficient to adjust the degree of fiber refining treatment so that papers made from those fibers will be more uniform, consistent, within the product specification and retard the paper production loss.

Optimization of photocatalytic degradation of methyl blue using silver ion doped titanium dioxide by combination of experimental design and response surface approach.

PubMed

Sahoo, C; Gupta, A K

2012-05-15

Photocatalytic degradation of methyl blue (MYB) was studied using Ag(+) doped TiO(2) under UV irradiation in a batch reactor. Catalytic dose, initial concentration of dye and pH of the reaction mixture were found to influence the degradation process most. The degradation was found to be effective in the range catalytic dose (0.5-1.5g/L), initial dye concentration (25-100ppm) and pH of reaction mixture (5-9). Using the three factors three levels Box-Behnken design of experiment technique 15 sets of experiments were designed considering the effective ranges of the influential parameters. The results of the experiments were fitted to two quadratic polynomial models developed using response surface methodology (RSM), representing functional relationship between the decolorization and mineralization of MYB and the experimental parameters. Design Expert software version 8.0.6.1 was used to optimize the effects of the experimental parameters on the responses. The optimum values of the parameters were dose of Ag(+) doped TiO(2) 0.99g/L, initial concentration of MYB 57.68ppm and pH of reaction mixture 7.76. Under the optimal condition the predicted decolorization and mineralization rate of MYB were 95.97% and 80.33%, respectively. Regression analysis with R(2) values >0.99 showed goodness of fit of the experimental results with predicted values. Copyright © 2012 Elsevier B.V. All rights reserved.

Species sensitivity distribution evaluation for selenium in fish eggs: considerations for development of a Canadian tissue-based guideline.

PubMed

DeForest, David K; Gilron, Guy; Armstrong, Sarah A; Robertson, Erin L

2012-01-01

A freshwater Se guideline was developed for consideration based on concentrations in fish eggs or ovaries, with a focus on Canadian species, following the Canadian Council of Ministers of the Environment protocol for developing guideline values. When sufficient toxicity data are available, the protocol recommends deriving guidelines as the 5th percentile of the species sensitivity distribution (SSD). When toxicity data are limited, the protocol recommends a lowest value approach, where the lowest toxicity threshold is divided by a safety factor (e.g., 10). On the basis of a comprehensive review of the current literature and an assessment of the data therein, there are sufficient egg and ovary Se data available for freshwater fish to develop an SSD. For most fish species, Se EC10 values (10% effect concentrations) could be derived, but for some species, only no-observed-effect concentrations and/or lowest-observed-effect concentrations could be identified. The 5th percentile egg and ovary Se concentrations from the SSD were consistently 20 µg/g dry weight (dw) for the best-fitting distributions. In contrast, the lowest value approach using a safety factor of 10 would result in a Se egg and ovary guideline of 2 µg/g dw, which is unrealistically conservative, as this falls within the range of egg and ovary Se concentrations in laboratory control fish and fish collected from reference sites. An egg and ovary Se guideline of 20 µg/g dw should be considered a conservative, broadly applicable guideline, as no species mean toxicity thresholds lower than this value have been identified to date. When concentrations exceed this guideline, site-specific studies with local fish species, conducted using a risk-based approach, may result in higher egg and ovary Se toxicity thresholds. Copyright © 2011 SETAC.

Stem bark extract and fraction of Persea americana (Mill.) exhibits bactericidal activities against strains of bacillus cereus associated with food poisoning.

PubMed

Akinpelu, David A; Aiyegoro, Olayinka A; Akinpelu, Oluseun F; Okoh, Anthony I

2014-12-30

The study investigates the in vitro antibacterial potentials of stem bark extracts of Persea americana on strains of Bacillus cereus implicated in food poisoning. The crude stem bark extracts and butanolic fraction at a concentration of 25 mg/mL and 10 mg/mL, respectively, exhibited antibacterial activities against test isolates. The zones of inhibition exhibited by the crude extract and the fraction ranged between 10 mm and 26 mm, while the minimum inhibitory concentration values ranged between 0.78 and 5.00 mg/mL. The minimum bactericidal concentrations ranged between 3.12 mg/mL-12.5 mg/mL and 1.25-10 mg/mL for the extract and the fraction, respectively. The butanolic fraction killed 91.49% of the test isolates at a concentration of 2× MIC after 60 min of contact time, while a 100% killing was achieved after the test bacterial cells were exposed to the butanolic fraction at a concentration of 3× MIC after 90 min contact time. Intracellular protein and potassium ion leaked out of the test bacterial cells when exposed to certain concentrations of the fraction; this is an indication of bacterial cell wall disruptions by the extract's butanolic fraction and, thus, caused a biocidal effect on the cells, as evident in the killing rate test results.

Relations for estimating unit-hydrograph parameters in New Mexico

USGS Publications Warehouse

Waltemeyer, Scott D.

2001-01-01

Data collected from 20 U.S. Geological Survey streamflow-gaging stations, most of which were operated in New Mexico between about 1969 and 1977, were used to define hydrograph characteristics for small New Mexico streams. Drainage areas for the gaging stations ranged from 0.23 to 18.2 square miles. Observed values for the hydrograph characteristics were determined for 87 of the most significant rainfall-runoff events at these gaging stations and were used to define regional regression relations with basin characteristics. Regional relations defined lag time (tl), time of concentration (tc), and time to peak (tp) as functions of stream length and basin shape. The regional equation developed for time of concentration for New Mexico agrees well with the Kirpich equation developed for Tennessee. The Kirpich equation is based on stream length and channel slope, whereas the New Mexico equation is based on stream length and basin shape. Both equations, however, underestimate tc when applied to larger basins where tc is greater than about 2 hours. The median ratio between tp and tc for the observed data was 0.66, which equals the value (0.67) recommended by the Natural Resources Conservation Service (formerly the Soil Conservation Service). However, the median ratio between tl and tc was only 0.42, whereas the commonly used ratio is 0.60. A relation also was developed between unit-peak discharge (qu) and time of concentration. The unit-peak discharge relation is similar in slope to the Natural Resources Conservation Service equation, but the equation developed for New Mexico in this study produces estimates of qu that range from two to three times as large as those estimated from the Natural Resources Conservation Service equation. An average value of 833 was determined for the empirical constant Kp. A default value of 484 has been used by the Natural Resources Conservation Service when site-specific data are not available. The use of a lower value of Kp in calculations generally results in a lower peak discharge. A relation between the empirical constant Kp and average channel slope was defined in this study. The predicted Kp values from the equation ranged from 530 to 964 for the 20 flood-hydrograph gaging stations. The standard error of estimate for the equation is 36 percent.

Problems associated with the use of immediately dangerous to life and health (IDLH) values for estimating the hazard of accidental chemical releases.

PubMed

Alexeeff, G V; Lipsett, M J; Kizer, K W

1989-11-01

The possibility of accidental industrial chemical releases has generated considerable recent attention. One area requiring research for emergency planning is the development of safe exposure concentrations for the public in the event of an inadvertent release. The United States Environmental Protection Agency (EPA) has established a list of extremely hazardous substances and suggested that the toxicity ranking for 92 hazardous materials could be based on the "immediately dangerous to life or health" (IDLH) values developed by the National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA). Eighty-four compounds with IDLH values for which published toxicologic data were available were reviewed to assess the appropriateness of applying such values to accidental release situations. When compared with 30-min animal median lethal concentrations (LC50s), 18 of the IDLHs reviewed were in the same range as lethal levels for animals. For 45 compounds the IDLH values were comparable to concentrations producing severe toxic effects (specifically, unconsciousness, incapacitation, or intolerable irritation). Where available, emergency planning guidelines for the military were compared to IDLHs, and in all 31 cases, the IDLHs exceeded the military exposure guidelines. Twenty compounds also were found to pose a potential cancer risk according to common regulatory guidelines, even under the assumption of a single, 30-min exposure at the IDLH concentration. In addition, the high degree of variability (four orders of magnitude) in the relationship of IDLH values to outcomes of lethality or severe toxicity suggests that the use of IDLH values as emergency planning guidelines for accidental releases is questionable.(ABSTRACT TRUNCATED AT 250 WORDS)

Investigation of radon level in air and tap water of workplaces at Thailand Institute of Nuclear Technology, Thailand

NASA Astrophysics Data System (ADS)

Sola, P.; Youngchuay, U.; Kongsri, S.; Kongtana, A.

2017-06-01

Thailand Institute of Nuclear Technology (TINT) has continuously monitored radiation exposure and radionuclide in workplaces specifically radon gas to estimate effective dose for workers. Radon exposure is the second leading cause of lung cancer in the world. In this study, radon in air and tap water at building no. 3, 7, 8, 9 and 18 on Ongkharak site of TINT have been measured for 5 years from 2012 to 2016. Radon level in air and tap water were investigated on 83 stations (workplaces) and 54 samples, respectively. Radon concentrations in air and tap water were measured by using the pulsed ionization chamber (ATMOS 12 DPX). Indoor radon concentrations in air were in the range of 12-138 Bq.m-3 with an average value of 30.13±17.05 Bq.m-3. Radon concentrations in tap water were in the range of 0.10 to 2.89 Bq.l-1 with an average value of 0.51±0.55 Bq.l-1. The results of radon concentrations at TINT were below the US Environmental Protection Agency (US EPA) safety limit of 148 Bq.m-3 and 150 Bq.l-1, for, air and tap water, respectively. The average effective dose for TINT’s workers due to indoor radon exposure was approximately 0.20±0.11 mSv.y-1. The value is 100 times less than the annual dose limit for limit occupational radiation worker defined by the International Commission on Radiological Protection (ICRP). As a result, the TINT’s workplaces are radiologically safe from radon content in air and tap water.

Cabin air quality: indoor pollutants and climate during intercontinental flights with and without tobacco smoking.

PubMed

Lindgren, T; Norbäck, D

2002-12-01

The aim was to determine cabin air quality and in-flight exposure for cabin attendants of specific pollutants during intercontinental flights. Measurements of air humidity, temperature, carbon dioxide (CO2), respirable particles, ozone (O3), nitrogen dioxide (NO2) and formaldehyde were performed during 26 intercontinental flights with Boeing 767-300 with and without tobacco smoking onboard. The mean temperature in cabin was 22.2 degrees C (range 17.4-26.8 degrees C), and mean relative air humidity was 6% (range 1-27%). The CO2 concentration during cruises was below the recommended limit of 1000 ppm during 96% of measured time. Mean indoor concentration of NO2 and O3, were 14.1 and 19.2 micrograms/m3, with maximum values of 37 and 66 micrograms/m3, respectively. The concentration of formaldehyde was below the detection limit (< 5 micrograms/m3), in most samples (77%), and the maximum value was 15 micrograms/m3. The mean concentration of respirable particles in the rear part of the aircraft (AFT galley area) was much higher (49 micrograms/m3) during smoking as compared with non-smoking conditions (3 micrograms/m3) (P < 0.001), with maximum values of 253 and 7 micrograms/m3. In conclusion, air humidity is very low on intercontinental flights, and the large variation of temperature shows a need for better temperature control. Tobacco smoking onboard leads to a significant pollution of respirable particles, particularly in the rear part of the cabin. The result supports the view that despite the high air exchange rate and efficient air filtration, smoking in commercial aircraft leads to a significant pollution and should be prohibited.

Quantification of inorganic arsenic exposure and cancer risk via consumption of vegetables in southern selected districts of Pakistan.

PubMed

Rehman, Zahir Ur; Khan, Sardar; Qin, Kun; Brusseau, Mark L; Shah, Mohammad Tahir; Din, Islamud

2016-04-15

Human exposures to arsenic (As) through different pathways (dietary and non-dietary) are considered to be one of the primary worldwide environmental health risks to humans. This study was conducted to investigate the presence of As in soil and vegetable samples collected from agricultural lands located in selected southern districts of Khyber Pakhtunkhwa (KPK) Province, Pakistan. We examined the concentrations of total arsenic (TAs), organic species of As such as monomethylarsonic acid (MMA) and dimethylarsonic acid (DMA), and inorganic species including arsenite (AsIII) and arsenate (AsV) in both soil and vegetables. The data were used to determine several parameters to evaluate human health risk, including bioconcentration factor (BCF) from soil to plant, average daily intake (ADI), health risk index (HRI), incremental lifetime cancer risk (ILTCR), and hazard quotient (HQ). The total As concentration in soil samples of the five districts ranged from 3.0-3.9mgkg(-1), exhibiting minimal variations from site to site. The mean As concentration in edible portions of vegetable samples ranged from 0.03-1.38mgkg(-1). It was observed that As concentrations in 75% of the vegetable samples exceeded the safe maximum allowable limit (0.1mgkg(-1)) set by WHO/FAO. The highest value of ADI for As was measured for Momordica charantia, while the lowest was for Allium chinense. The results of this study revealed minimal health risk (HI<1) associated with consumption of vegetables for the local inhabitants. The ILTCR values for inorganic As indicated a minimal potential cancer risk through ingestion of vegetables. In addition, the HQ values for total As were <1, indicating minimal non-cancer risk. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantification of inorganic arsenic exposure and cancer risk via consumption of vegetables in southern selected districts of Pakistan

PubMed Central

Rehman, Zahir Ur; Khan, Sardar; Qin, Kun; Brusseau, Mark L; Shah, Mohammad Tahir; Din, Islamud

2016-01-01

Human exposures to arsenic (As) through different pathways (dietary and non-dietary) are considered to be one of the primary worldwide environmental health risks to humans. This study was conducted to investigate the presence of As in soil and vegetable samples collected from agricultural lands located in selected southern districts of Khyber Pakhtunkhwa (KPK) Province, Pakistan. We examined the concentrations of total arsenic (TAs), organic species of As such as monomethylarsonic acid (MMA) and dimethylarsonic acid (DMA), and inorganic species including arsenite (AsIII) and arsenate (AsV) in both soil and vegetable. The data were used to determine several parameters to evaluate human health risk, including bioconcentration factor (BCF) from soil to plant, average daily intake (ADI), health risk index (HRI), incremental lifetime cancer risk (ILTCR), and hazard quotient (HQ). The total As concentration in soil samples of the five districts ranged from 3.0-3.9 mg kg−1, exhibiting minimal variations from site to site. The mean As concentration in edible portions of vegetable samples ranged from 0.03-1.38 mg kg−1. It was observed that As concentrations in 75% of the vegetable samples exceeded the safe maximum allowable limit (0.1 mg kg−1) set by WHO/FAO. The highest value of ADI for As was measured for M. charantia, while the lowest was for A. chinense. The results of this study revealed minimal health risk (HI <1) associated with consumption of vegetables for the local inhabitants. The ILTCR values for inorganic As indicated a minimal potential cancer risk through ingestion of vegetables. In addition, the HQ values for total As were <1, indicating minimal non-cancer risk. PMID:26820935

In vitro synergism of trifluorothymidine and ganciclovir against HSV-1.

PubMed

Hobden, Jeffery A; Kumar, Manish; Kaufman, Herbert E; Clement, Christian; Varnell, Emily D; Bhattacharjee, Partha S; Hill, James M

2011-02-01

To determine whether trifluorothymidine (TFT) and ganciclovir (GCV) are synergistic against herpes simplex virus type 1 (HSV-1). TFT and GCV activity against 12 strains of HSV-1 (including an acyclovir-resistant strain) was measured by plaque-forming unit (PFU) inhibition. Cellular toxicity was assessed with an MTT dye reduction assay. Synergism was determined by calculating fractional inhibitory concentration (FIC indices) based on PFU reduction. Concentrations of TFT resulting in 50% inhibition of PFUs (IC(50)) of acyclovir-susceptible HSV-1 strains ranged from 3.07 ± 0.36 to 12.52 ± 0.61 μM. GCV IC(50) values ranged from 0.40 ± 0.02 to 1.59 ± 0.14 μM. IC(50) values of TFT and GCV against the acyclovir-resistant strain were 15.40 ± 3.17 and 93.00 ± 9.64 μM, respectively. Concentrations of TFT or GCV resulting in 50% cell cytotoxicity (CC(50)) were 0.99 ± 0.01 and 92.91 ± 8.92 μM, respectively. TFT and GCV combined (10:1) were 10 times more potent against all acyclovir-susceptible HSV-1 strains. For 8 of 12 HSV-1 strains, the IC(50) of TFT and GCV combined was lower than the CC(50) of either drug. For acyclovir-susceptible HSV-1 strains, TFT and GCV combined generated a FIC index of <0.5, suggesting strong synergism between the two drugs. The FIC value for TFT and GCV combined against the acyclovir-resistant HSV-1 strain was 0.84, indicating nonantagonism. TFT and GCV are synergistic against acyclovir-susceptible HSV-1 at concentrations significantly less toxic than if each antiviral were used as a sole agent.

In Vitro Synergism of Trifluorothymidine and Ganciclovir against HSV-1

PubMed Central

Hobden, Jeffery A.; Kumar, Manish; Kaufman, Herbert E.; Clement, Christian; Varnell, Emily D.; Bhattacharjee, Partha S.

2011-01-01

Purpose. To determine whether trifluorothymidine (TFT) and ganciclovir (GCV) are synergistic against herpes simplex virus type 1 (HSV-1). Methods. TFT and GCV activity against 12 strains of HSV-1 (including an acyclovir-resistant strain) was measured by plaque-forming unit (PFU) inhibition. Cellular toxicity was assessed with an MTT dye reduction assay. Synergism was determined by calculating fractional inhibitory concentration (FIC indices) based on PFU reduction. Results. Concentrations of TFT resulting in 50% inhibition of PFUs (IC50) of acyclovir-susceptible HSV-1 strains ranged from 3.07 ± 0.36 to 12.52 ± 0.61 μM. GCV IC50 values ranged from 0.40 ± 0.02 to 1.59 ± 0.14 μM. IC50 values of TFT and GCV against the acyclovir-resistant strain were 15.40 ± 3.17 and 93.00 ± 9.64 μM, respectively. Concentrations of TFT or GCV resulting in 50% cell cytotoxicity (CC50) were 0.99 ± 0.01 and 92.91 ± 8.92 μM, respectively. TFT and GCV combined (10:1) were 10 times more potent against all acyclovir-susceptible HSV-1 strains. For 8 of 12 HSV-1 strains, the IC50 of TFT and GCV combined was lower than the CC50 of either drug. For acyclovir-susceptible HSV-1 strains, TFT and GCV combined generated a FIC index of <0.5, suggesting strong synergism between the two drugs. The FIC value for TFT and GCV combined against the acyclovir-resistant HSV-1 strain was 0.84, indicating nonantagonism. Conclusions. TFT and GCV are synergistic against acyclovir-susceptible HSV-1 at concentrations significantly less toxic than if each antiviral were used as a sole agent. PMID:20861476

Hydrogen isotope correction for laser instrument measurement bias at low water vapor concentration using conventional isotope analyses: application to measurements from Mauna Loa Observatory, Hawaii.

PubMed

Johnson, L R; Sharp, Z D; Galewsky, J; Strong, M; Van Pelt, A D; Dong, F; Noone, D

2011-03-15

The hydrogen and oxygen isotope ratios of water vapor can be measured with commercially available laser spectroscopy analyzers in real time. Operation of the laser systems in relatively dry air is difficult because measurements are non-linear as a function of humidity at low water concentrations. Here we use field-based sampling coupled with traditional mass spectrometry techniques for assessing linearity and calibrating laser spectroscopy systems at low water vapor concentrations. Air samples are collected in an evacuated 2 L glass flask and the water is separated from the non-condensable gases cryogenically. Approximately 2 µL of water are reduced to H(2) gas and measured on an isotope ratio mass spectrometer. In a field experiment at the Mauna Loa Observatory (MLO), we ran Picarro and Los Gatos Research (LGR) laser analyzers for a period of 25 days in addition to periodic sample collection in evacuated flasks. When the two laser systems are corrected to the flask data, they are strongly coincident over the entire 25 days. The δ(2)H values were found to change by over 200‰ over 2.5 min as the boundary layer elevation changed relative to MLO. The δ(2)H values ranged from -106 to -332‰, and the δ(18)O values (uncorrected) ranged from -12 to -50‰. Raw data from laser analyzers in environments with low water vapor concentrations can be normalized to the international V-SMOW scale by calibration to the flask data measured conventionally. Bias correction is especially critical for the accurate determination of deuterium excess in dry air. Copyright © 2011 John Wiley & Sons, Ltd.

Off-pump coronary bypass surgery adversely affects alveolar gas exchange.

PubMed

Gasparović, Hrvoje; Unić, Daniel; Sutlić, Zeljko; Husedzinović, Ino; Biocina, Bojan; Rudez, Igor; Nikić, Nada; Jelić, Ivan

2008-03-01

While the introduction of off-pump myocardial revascularization (OPCAB) has initially shown promise in reducing respiratory complications inherent to conventional coronary surgery, it has failed to eradicate them. Our study focused on quantifying the lactate release from the lungs and the dysfunction at the level of the alveolar-capillary membrane precipitated by OPCAB at different time points after the insult. Furthermore, we aimed to determine the impact of pulmonary lactate production on systemic lactic acid concentrations. The study was conducted in a prospective observational fashion. Forty consecutive patients undergoing OPCAB were analyzed. The mean patient age was 60 +/- 10 years. The mean EUROScore was 3.8 +/- 2.9. The alveolar-arterial O2 gradient increased from 19 [range 9 to 30] to 26 [range 20 to 34] kPa (P < 0.001) and remained elevated up to 6 hours after surgery. It rapidly declined again by 18 hours postoperatively. The observed increase in the pulmonary lactate release (PLR) from a baseline value of 0.022 [range -0.074 to 0.066] to 0.089 [range 0.016 to 0.209] mmol/min/m2 at six hours postoperatively did not reach statistical significance (P = 0.105). The systemic arterial lactate (Ls) concentration increased from 0.94 [range 0.78 to 1.06] to 1.39 [range 0.97 to 2.81] mmol/L (P < 0.001). The venoarterial pCO2 difference showed no significant change in comparison to baseline values. The mortality in the studied group was 2.5% (1/40). The pulmonary lactate production showed a statistically significant correlation with the systemic lactate concentration (R = 0.46; P = 0.003). Pulmonary injury following off pump myocardial revascularization was evidenced by a prompt increase in the alveolar-arterial oxygen gradient. The alveolar-arterial O2 gradient correlated with the duration of mechanical ventilation.

Experimental investigation of cephapirin adsorption to quartz filter sands and dune sands

NASA Astrophysics Data System (ADS)

Peterson, Jonathan W.; O'Meara, Theresa A.; Seymour, Michael D.

2008-08-01

Batch experiments were performed to investigate cephapirin (a widely used veterinary antibiotic) adsorption on various size sands of low total organic carbon content (0.08-0.36 wt%). In the aqueous concentration range investigated (11-112 μmol/L cephapirin), adsorption to nearly pure quartz filter sands (0.50-3.35 mm diameter) is low. Isotherms are S-shaped and most display a region of minimum adsorption, where decreased adsorption occurs with increasing solution concentration, followed by increased adsorption at higher concentrations. Cephapirin adsorption to quartz-rich, feldspar-bearing dune sands (0.06-0.35 mm diameter), and the smallest quartz filter sand investigated (0.43-0.50 mm), can be described by linear sorption isotherms over the range of concentrations investigated. Distribution coefficients ( K d) range from 0.94 to 3.45 L/kg. No systematic relationship exists between grain size and amount of adsorption for any of the sands investigated. Cephapirin adsorption is positively correlated to the feldspar ratio (K-feldspar/(albite + Ca-plagioclase). Feldspar-ratio normalization of distribution coefficients was more effective than organic carbon normalization at reducing variability of K d values in the dune sands investigated.

Levels, distribution and air-soil exchange fluxes of polychlorinated biphenyls (PCBs) in the environment of Punjab Province, Pakistan.

PubMed

Syed, Jabir Hussain; Malik, Riffat Naseem; Li, Jun; Zhang, Gan; Jones, Kevin C

2013-11-01

An initial survey of the concentrations of polychlorinated biphenyl (PCB) compounds in air and soils across industrial and agricultural areas of Punjab Province, Pakistan, was conducted from January to March 2011. The total concentration of all PCBs (31 PCBs) ranged from 34 to 389pgm(-3) in air and from 7 to 45ngg(-1) dry weight in soils, where both ranges were similar to the average ranges in other areas of the world. PCBs were elevated across industrial regions near urban and industrial sources. Consistently low air concentrations of PCBs at the agricultural sites suggest that they are less widespread or uniformly distributed in the Pakistani atmosphere. The calculated air and soil fugacity fraction values indicated that soils are a potential secondary source of PCBs in agricultural areas, whereas they are in equilibrium or atmospheric deposition in industrial and urban areas. TEQ concentrations of dioxin-like PCBs for soil samples met the Canadian standard. However, local authorities should address the human health threats from urban and industrial soils in Punjab Province, Pakistan. Copyright © 2013 Elsevier Inc. All rights reserved.

Passive Measurements of Thoron and its Progeny in some Dwellings in Ireland

NASA Astrophysics Data System (ADS)

Choncubhair, Órlaith Ní; Laughlin, James Mc; Tokonami, Shinji

2008-08-01

In this paper, an account is given of the development, calibration and field use of a passive alpha track detector sensitive to thoron as well as to radon. No database of thoron and thoron progeny concentrations in dwellings in Ireland exists and, as a result, the level of exposure of the Irish population to thoron and its progeny is unknown. As an initial or pilot stage in establishing such a data base measurements of thoron and thoron progeny concentrations (the latter expressed in Equilibrium Equivalent Thoron Concentration (EETC)) were made in 40 randomly chosen Irish dwellings. The EETC measurements were made using a passive thoron progeny deposition rate monitor designed and supplied by NIRS (Japan). In addition standard unmodified SSI passive radon detectors were used to measure radon in these dwellings. The measured thoron concentrations ranged from below the level of detection to 154 Bq/m3 while the radon gas ranged from 15 to 179 Bq/m3. The thoron progeny EETC values for these dwellings ranged from 0.03 to 7.7 Bq/m3. An account is also given of the dosimetric implications of these measurements.

Pharmacokinetics of enrofloxacin following oral and subcutaneous administration in the common ringtail possum (Pseudocheirus peregrinus).

PubMed

Scheelings, T F; Devi, J L; Woodward, A P; Whittem, T

2015-10-01

[Correction added on 23 March 2015, after first online publication: Terminal half-life values of enrofloxacin is corrected in the fourth sentence of the abstract] Clinically healthy common ringtail possums (n = 5) received single doses of 10 mg/kg enrofloxacin orally and then 2 weeks later subcutaneously. Serial plasma samples were collected over 24 h for each treatment phase, and enrofloxacin concentrations were determined using a validated HPLC assay. Pharmacokinetic parameters were determined by noncompartmental analysis. Following oral administration, plasma concentrations were of therapeutic relevance (Cmax median 5.45 μg/mL, range 2.98-6.9 μg/mL), with terminal-phase half-life (t½ ) shorter than in other species (median 3.09 h, range 1.79-5.30 h). In contrast, subcutaneous administration of enrofloxacin did not achieve effective plasma concentrations, with plasma concentrations too erratic to fit the noncompartmental model except in one animal. On the basis of the AUC:MIC, enrofloxacin administered at 10 mg/kg orally, but not subcutaneously, is likely to be effective against a range of bacterial species that have been reported in common ringtail possums. © 2015 John Wiley & Sons Ltd.

Occurrence and risk assessment of organophosphorus and brominated flame retardants in the River Aire (UK).

PubMed

Cristale, Joyce; Katsoyiannis, Athanasios; Sweetman, Andrew J; Jones, Kevin C; Lacorte, Silvia

2013-08-01

This study presents the occurrence and risk of PBDEs, new brominated and organophosphorus flame retardants along a river affected by urban and industrial pressures (River Aire, UK). Tris(2-choroethyl) phosphate (TCEP), tris(2-chloro-1-methylethyl) phosphate (TCPP), tris[2-chloro-1-(chloromethyl)ethyl] phosphate (TDCP) and triphenyl phosphate (TPhP) were detected in all samples, with TCPP present at the highest concentrations, ranging from 113 to 26,050 ng L⁻¹. BDE-209 was detected in most of the sampled sites, ranging from 17 to 295 ng L⁻¹, while hexabromobenzene (HBB) and pentabromoethyl benzene (PBEB) were seldom detected. A risk quotients based on predicted no effect concentrations (PNEC) and flame retardants water concentration proved significant risk for adverse effects for algae, Daphnia and fish in sites close to industrial and urban sewage discharges. This study provides a protocol for the risk estimation of priority and new generation flame retardants based on river concentrations and toxicological values. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dielectric dispersion of short single-stranded DNA in aqueous solutions with and without added salt.

PubMed

Katsumoto, Yoichi; Omori, Shinji; Yamamoto, Daisuke; Yasuda, Akio; Asami, Koji

2007-01-01

Dielectric spectroscopy measurements were performed for aqueous solutions of short single-stranded DNA with 30 to 120 bases of thymine over a frequency range of 10;{5} to 10;{8}Hz . Dielectric dispersion was found to include two relaxation processes in the ranges from 10;{5} to 10;{6} and from 10;{6} to 10;{8}Hz , respectively, with the latter mainly discussed in this study. The dielectric increment and the relaxation time of the high-frequency relaxation of DNA in solutions without added salt exhibited concentration and polymer-length dependences eventually identical to those for dilute polyion solutions described in previous studies. For solutions with added salt, on the other hand, those dielectric parameters were independent of salt concentration up to a certain critical value and started to decrease with further increasing salt concentration. This critical behavior is well explained by our newly extended cell model that takes into account the spatial distribution of loosely bound counterions around DNA molecules as a function of salt concentration.

Transfer factors and effective half-lives of (134)Cs and (137)Cs in different environmental sample types obtained from Northern Finland: case Fukushima accident.

PubMed

Koivurova, Matias; Leppänen, Ari-Pekka; Kallio, Antti

2015-08-01

The Fukushima NPP accident caused a small but detectable cesium fallout in northern Finland, of the order of 1 Bq/m(2). This fallout transferred further to soil, water, flora and fauna. By using modern HPGe detector systems traces of (134)Cs from the Fukushima fallout were observed in various samples of biota. In northern Finland different types of environmental samples such as reindeer meat, berries, fish, lichens and wolf were collected during 2011-2013. The observed (134)Cs concentrations varied from 0.1 Bq/kg to a few Bq/kg. By using the known (134)Cs/(137)Cs ratio observed in Fukushima fallout the increase of the Fukushima accident to the (137)Cs concentrations was found to vary from 0.06 % to 6.9 % depending on the sample type. The aggregated transfer factors (Tag) and effective half-lives (Teff) for (134)Cs and (137)Cs were also determined and then compared with known values found from earlier studies which are calculated based on the fallout from the Chernobyl accident. Generally, the Tag and Teff values determined in this study were found to agree with the values found in the earlier studies. The Teff values were sample-type specific and were found to vary from 0.91 to 2.1 years for (134)Cs and the estimates for (137)Cs ranged between 1.6 and 19 years. Interestingly, the ground lichens had the longest Teff whereas the beard lichen had the shortest. In fauna, highest Tag values were determined for wolf meat ranging between 1.0 and 2.2 m(2)/kg. In flora, the highest Tag values were determined for beard lichens, ranging from 1.9 m(2)/kg to 3.5 m(2)/kg. Copyright © 2015 Elsevier Ltd. All rights reserved.

Serum zinc, copper, retinol-binding protein, prealbumin, and ceruloplasmin concentrations in infants receiving intravenous zinc and copper supplementation.

PubMed

Lockitch, G; Godolphin, W; Pendray, M R; Riddell, D; Quigley, G

1983-02-01

One hundred twenty-seven newborn infants requiring parenteral nutrition were randomly assigned to receive differing amounts of zinc (40 to 400 micrograms/kg/day) and copper (20 or 40 micrograms/kg/day) supplementation within five birth weight groups (600 to 2,500 gm). The serum zinc concentration remained relatively constant in the group receiving the most zinc supplementation after two weeks of therapy, but declined sharply in the groups receiving less supplementation. No effect of increased copper intake was noted on ceruloplasmin values, but a difference in serum copper concentrations was noted at two weeks. No correlation was noted between serum zinc and copper values or among those for serum zinc, retinol-binding protein, and prealbumin. Reference ranges were defined for serum zinc, copper, retinol-binding protein, prealbumin, and ceruloplasmin in the preterm infant.

Phosphorus reduces the zinc concentration in cereals pot-grown on calcareous Vertisols from southern Spain.

PubMed

Sánchez-Rodríguez, Antonio Rafael; Del Campillo, María Carmen; Torrent, José

2017-08-01

Zinc deficiency, a major problem in crops grown on soils low in available Zn, is even more important in phosphorus-rich soils. This work aimed to elucidate the effects of soil P and Zn levels, and of fertilizer application, on yield and Zn concentration in cereal grains. Wheat and barley were successively pot-grown on 20 calcareous Vertisols low in available Zn and ranging widely in available P. Grain yield in the plants grown on the native soils was positively correlated with Olsen P but not with diethylenetriaminepentaacetic acid (DTPA)-extractable Zn except for wheat on P-rich soils. Grain Zn concentration was negatively correlated with Olsen P. Grain Zn uptake differed little among soils. Application of P to the soils increased grain yield insignificantly and P concentration significantly; however, it reduced grain Zn concentration (particularly at low Olsen P values). Applying Zn alone only increased grain Zn concentration, whereas applying P and Zn in combination increased yield and grain Zn concentration at low and high Olsen P values, respectively. Applying P alone to plants grown on calcareous Vertisols low in available P and Zn may in practice reduce grain Zn concentrations while not increasing grain yield significantly. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Macronutrient status of UK groundwater: Nitrogen, phosphorus and organic carbon.

PubMed

Stuart, M E; Lapworth, D J

2016-12-01

Groundwater is a large, slowly changing pool of the macronutrients nitrogen (N), phosphorus (P) and dissolved organic carbon (DOC), with impacts on receptors, surface waters, dependent wetlands and coastal marine ecosystems. Sources of N to groundwater include fertilisers, animal wastes and septic effluents. N species are well-quantified in groundwater and NO 3 -N has a wide range of median values (0-12mg/L). The highest concentrations are in the Chalk of East Anglia and Humberside and the Permo-Triassic Sandstone (PTS) of Staffordshire. The highest concentrations of NH 4 -N are found in confined aquifers. N concentrations have increased with time peaking during the 1980s. Changes in practice have led to the reduction observed in rapidly-responding aquifers. For the Chalk, where the unsaturated zone is thick, improvements may not be seen for decades. P is less well-characterised in UK groundwater reflecting the lack of historical interest in groundwater P, although it can be significant in some aquifer matrices. Groundwater P concentrations are elevated in sandstone formations compared to other lithology and highest in the PTS of the Midlands and northern England (median values>50μg/L). Overall half of the aquifers studied in the UK have median TDP>50μg/L, with values of up to 100μg/L under some urban areas, such as Manchester and Liverpool as well as the Lee Valley. P concentrations in arable areas are variable (20-100μg/L), whereas under semi-natural conditions they are lower (20-50μg/L). There is little information on P trends in groundwater. Most DOC is derived from soils, playing an important part in redox processes. The aquifer matrix can contain high OC and contribute significantly to groundwater DOC. Median values range between 0.4 and 9mg/L, but rarely exceed 5mg/L, except in the Chalk of Yorkshire and Humberside and PTS of Liverpool which have long legacies of anthropogenic pollution. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.