Statistical Analysis Of Heavy Metals Concentration In Watermelon Plants Irrigated By Wastewater

NASA Astrophysics Data System (ADS)

Khanjani, M. J.; Maghsoudi moud, A. A.; Saffari, V. R.; Hashamipor, S. M.; Soltanizadeh, M.

2008-01-01

Concentration of heavy metals in vegetables irrigated by urban wastewater is a cause of serious concern due to the potentials health problems of consuming contaminated produce. In this study it is tried to model the concentration of heavy metals (Cd, Cr, Cu, Fe,…) as a function of their concentration in watermelon roots and stems. Our study shows there is a good relationship between them for most of collected data. By measuring the concentration in root and stem of watermelon plant samples before harvesting, the concentration of heavy metal in watermelon's fruit can be estimated by presented mathematical models. This study shows the concentrations of heavy metals in fruits, roots and stems of watermelon plants are very high and in dangerous level when irrigated by municipal waste water.

VERSATILE AEROSOL CONCENTRATION ENRICHMENT SYSTEM (VACES) FOR SIMULTANEOUS IN VIVO AND IN VITRO EVALUATION OF TOXIC EFFECTS OF ULTRAFINE, FINE AND COARSE AMBIENT PARTICLES. PART I: DEVELOPMENT AND LABORATORY CHARACTERIZATION. (R827352C001)

EPA Science Inventory

This study presents the development and bench-testing of a versatile aerosol concentration enrichment system (VACES) capable of simultaneously concentrating ambient particles of the coarse, fine and ultrafine size fractions for conducting in vivo and in vitro studies. The VACE...

Experimental investigation of nucleate pool boiling characteristics of high concentrated alumina/water nanofluids

NASA Astrophysics Data System (ADS)

Kshirsagar, Jagdeep M.; Shrivastava, Ramakant

2018-06-01

In Present study, the critical heat flux (CHF) and boiling heat transfer coefficient of alumina nanoparticles with the base fluid as deionised water is measured. The selected concentrations of nanofluids for the experimentation are from 0.3, 0.6, 0.9, 1.2 and 1.5 wt%. The main objective to select higher concentration is that to study the surface morphology of heater surface at higher concentrations and its effect on critical heat flux and heat transfer coefficient. It is observed that the critical heat flux enhancement rate decreases as concentration increases and surface roughness of heater surface decreases after 1.2 wt% concentration of nanofluids.

Navy Coalescence Test on Petroleum F-76 Fuel with FAME Additive at 1%

DTIC Science & Technology

2012-06-20

sponsored studies have shown that in many countries there is an undesirable concentration of Fatty Acid Methyl - Ester ( FAME ) present in the F-76. This...have shown that in many countries there may be an undesirable concentration of Fatty Acid Methyl - Ester ( FAME ) present in the F-76. This study was...Acid Methyl - Ester DEFINITIONS Turnover ..................amount of time it takes to flow the entire volume of fluid in a container, also

Regional differences in concentrations of regulatory peptides in human colon mucosal biopsy.

PubMed

Calam, J; Ghatei, M A; Domin, J; Adrian, T E; Myszor, M; Gupta, S; Tait, C; Bloom, S R

1989-08-01

The study was undertaken to examine regional differences in the concentrations of five regulatory peptides in the human colonic mucosa. Biopsies were obtained during routine colonoscopy from 33 patients whose colonic mucosa was macroscopically and histologically normal. Regulatory peptides were extracted, and measured by specific radioimmunoassays. Concentrations of three peptides that are present predominantly in endocrine cells within colonic mucosa increased significantly towards the rectum: Mean concentrations of peptide YY, enteroglucagon, and somatostatin were about three times greater in the rectum than in the cecum. However, concentrations of two peptides that are present in mucosal nerve fibers diminished significantly towards the rectum: Mean rectal concentrations of vasoactive intestinal peptide and peptide histidine methionine were both about 0.6 of mean cecal concentrations. Concentrations of all five peptides were lower in biopsies taken from colonic polyps than in normal colonic mucosa. Regional differences in colonic mucosal concentrations of regulatory peptides probably reflect differences in the physiological functions of different parts of the colon.

Concentration data and dimensionality in groundwater models: evaluation using inverse modelling

USGS Publications Warehouse

Barlebo, H.C.; Hill, M.C.; Rosbjerg, D.; Jensen, K.H.

1998-01-01

A three-dimensional inverse groundwater flow and transport model that fits hydraulic-head and concentration data simultaneously using nonlinear regression is presented and applied to a layered sand and silt groundwater system beneath the Grindsted Landfill in Denmark. The aquifer is composed of rather homogeneous hydrogeologic layers. Two issues common to groundwater flow and transport modelling are investigated: 1) The accuracy of simulated concentrations in the case of calibration with head data alone; and 2) The advantages and disadvantages of using a two-dimensional cross-sectional model instead of a three-dimensional model to simulate contaminant transport when the source is at the land surface. Results show that using only hydraulic heads in the nonlinear regression produces a simulated plume that is profoundly different from what is obtained in a calibration using both hydraulic-head and concentration data. The present study provides a well-documented example of the differences that can occur. Representing the system as a two-dimensional cross-section obviously omits some of the system dynamics. It was, however, possible to obtain a simulated plume cross-section that matched the actual plume cross-section well. The two-dimensional model execution times were about a seventh of those for the three-dimensional model, but some difficulties were encountered in representing the spatially variable source concentrations and less precise simulated concentrations were calculated by the two-dimensional model compared to the three-dimensional model. Summed up, the present study indicates that three dimensional modelling using both hydraulic heads and concentrations in the calibration should be preferred in the considered type of transport studies.

Review of Pesticide Urinary Biomarker Measurements from Selected US EPA Children’s Observational Exposure Studies

PubMed Central

Egeghy, Peter P.; Cohen Hubal, Elaine A.; Tulve, Nicolle S.; Melnyk, Lisa J.; Morgan, Marsha K.; Fortmann, Roy C.; Sheldon, Linda S.

2011-01-01

Children are exposed to a wide variety of pesticides originating from both outdoor and indoor sources. Several studies were conducted or funded by the EPA over the past decade to investigate children’s exposure to organophosphate and pyrethroid pesticides and the factors that impact their exposures. Urinary metabolite concentration measurements from these studies are consolidated here to identify trends, spatial and temporal patterns, and areas where further research is required. Namely, concentrations of the metabolites of chlorpyrifos (3,5,6-trichloro-2-pyridinol or TCPy), diazinon (2-isopropyl-6-methyl-4-pyrimidinol or IMP), and permethrin (3-phenoxybenzoic acid or 3-PBA) are presented. Information on the kinetic parameters describing absorption and elimination in humans is also presented to aid in interpretation. Metabolite concentrations varied more dramatically across studies for 3-PBA and IMP than for TCPy, with TCPy concentrations about an order of magnitude higher than the 3-PBA concentrations. Temporal variability was high for all metabolites with urinary 3-PBA concentrations slightly more consistent over time than the TCPy concentrations. Urinary biomarker levels provided only limited evidence of applications. The observed relationships between urinary metabolite levels and estimates of pesticide intake may be affected by differences in the contribution of each exposure route to total intake, which may vary with exposure intensity and across individuals. PMID:21655147

Impairment related to blood amphetamine and/or methamphetamine concentrations in suspected drugged drivers.

PubMed

Gustavsen, Ingebjørg; Mørland, Jørg; Bramness, Jørgen G

2006-05-01

Experimental studies have investigated effects of low oral doses of amphetamine and methamphetamine on psychomotor functions, while less work has been done on effects of high doses taken by abusers in real-life settings. There are indications that intake of high doses may impair traffic related skills, and that abuse of amphetamines may cause hypersomnolence at the end-of-binge. The present study aimed at investigating the concentration-effect relationship between blood amphetamines concentrations and impairment in a population of real-life users. Eight hundred and seventy-eight cases with amphetamine or methamphetamine as the only drugs present in the blood samples were selected from the impaired driver registry at The Norwegian Institute of Public Health. In each case the police physician had concluded on whether the driver was impaired or not. 27% of the drivers were judged as not impaired, while 73% were judged as impaired. There was a positive relationship between blood amphetamines concentrations and impairment. The relationship reached a ceiling at blood amphetamines concentrations of 0.27-0.53 mg/l. Younger drivers were more often judged impaired than older drivers at similar concentrations. Despite the performance enhancing qualities of amphetamines demonstrated in some low dose laboratory experiments; this study revealed a positive relationship between blood amphetamines concentration and traffic related impairment.

Numerical Study of g-Jitter Induced Double-Diffusive Convection

NASA Technical Reports Server (NTRS)

Shu, Y.; Li, B. Q.; deGroh, Henry C.

2001-01-01

A finite element study is presented of double-diffusive convection driven by g-jitter in a microgravity environment. Mathematical formulations are presented and extensive simulations are carried out for g-jitter induced fluid flow, temperature distribution, and solutal transport in an alloy system under consideration for space flights. Computations include the use of idealized single-frequency and multi-frequency g-jitter as well as the real g-jitter data taken during an actual Space Shuttle fight. Little correlation is seen between these velocity components for the g-jitter components studied. The temperature field is basically undisturbed by convection because of a small Pr number for the fluid. The disturbance of the concentration field, however, is pronounced, and the local variation of the concentration follows the velocity oscillation in time. It is found that although the concentration field varies in both position and time, the local concentration gradient remains approximately constant in time. Numerical study further indicates that with an increase in g-jitter force (or amplitude), the nonlinear convective effects become much more obvious, which in turn drastically change the concentration fields. The simulated results computed using the g-jitter data taken during space flights show that both the velocity and concentration become random, following approximately the same pattern as the g-jitter perturbations.

Dispersion model studies for Space Shuttle environmental effects activities

NASA Technical Reports Server (NTRS)

1981-01-01

The NASA/MSFC REED computer code was developed for predicting concentrations, dosage, and deposition downwind from rocket vehicle launches. The calculation procedures and results of nine studies using the code are presented. Topics include plume expansion, hydrazine concentrations, and hazard calculations for postulated fuel spills.

Quality of shallow ground water in alluvial aquifers of the Willamette Basin, Oregon, 1993-95

USGS Publications Warehouse

Hinkle, Stephen R.

1997-01-01

The current (1993?95) quality of shallow ground water (generally, <25 meters below land surface) in Willamette Basin alluvium is described using results from two studies. A Study-Unit Survey, or regional assessment of shallow groundwater quality in alluvium, was done from June through August 1993. During the Study-Unit Survey, data were collected from 70 domestic wells chosen using a random-selection process and located mostly in areas of agricultural land use. An urban Land-Use Study, which was a reconnaissance of shallow urban ground-water quality from 10 monitoring wells installed in areas of residential land use, was done in July 1995. Concentrations of nitrite plus nitrate (henceforth, nitrate, because nitrite concentrations were low) ranged from <0.05 to 26 mg N/L (milligrams nitrogen per liter) in ground water from 70 Study-Unit-Survey wells; concentrations exceeded the U.S. Environmental Protection Agency (USEPA) Maximum Contaminant Level (MCL) of 10 mg N/L in 9 percent of Study-Unit-Survey samples. Relationships were observed between nitrate concentrations and dissolved-oxygen concentrations, the amount of clay present within and overlying aquifers, overlying geology, and upgradient land use. Tritium (3H) data indicate that 21 percent of Study-Unit-Survey samples represented water recharged prior to 1953. Nitrogen-fertilizer application rates in the basin have increased greatly over the past several decades. Thus, some observed nitrate concentrations may reflect nitrogen loading rates that were smaller than those presently applied in the basin. Concentrations of phosphorus ranged from <0.01 to 2.2 mg/L in 70 Study-Unit-Survey wells and exceeded 0.10 mg/L in 60 percent of the samples. Phosphorus and nitrate concentrations were inversely correlated. From 1 to 5 pesticides and pesticide degradation products (henceforth, pesticides) were detected in ground water from each of 23 Study-Unit-Survey wells (33 percent of 69 wells sampled for pesticides) for a total of 51 pesticide detections. Thirteen different pesticides were detected; atrazine was the most frequently encountered pesticide. Although detections were widespread, concentrations were low (generally <1,000 ng/L [nanograms per liter]). (One ng/L is equal to 0.001 mg/L [micrograms per liter].) One detection (dinoseb, at 7,900 ng/L) exceeded a USEPA MCL. Relationships were observed between the occurrence of pesticides and the amount of clay present within and overlying aquifers, overlying geology, and land use. Between 1 and 5 volatile organic compounds (VOCs) were detected at each of 7 Study-Unit-Survey sites (11 percent of 65 sites evaluated), for a total of 14 VOC detections. One detection (tetrachloroethylene, at 29 mg/L) exceeded a USEPA MCL. Other detections were at low concentrations (0.2 to 2.0 mg/L). VOC detections generally were from sites associated with urban land use. Concentrations of arsenic ranged from <1 to 13 mg/L in 70 Study-Unit-Survey wells. Concentrations in 16 percent of samples exceeded the USEPA Risk-Specific-Dose Health Advisory of 2 mg/L. Radon concentrations ranged from 200 to 1,200 pCi/L (picocuries per liter) in 51 Study-Unit-Survey wells. All samples exceeded the USEPA Risk-Specific-Dose Health Advisory of 150 pCi/L. All urban Land-Use-Study samples were well oxygenated; thus, nitrate reduction probably did not affect these samples. Urban Land-Use-Study nitrate concentrations were similar to those of the well oxygenated, agricultural subset of Study-Unit-Survey samples. Pesticides were detected in samples from three urban Land-Use-Study sites, but concentrations were low (1 to 5 ng/L). In contrast, VOCs were detected in ground water from 80 percent of urban Land-Use-Study wells; concentrations ranged up to 7.6 mg/L. Trace-element concentrations in the urban Land-Use Study samples were low. Median concentrations consistently were <10 mg/L and frequently were <1 mg/L

Contemporary biological markers of exposure to fluoride.

PubMed

Rugg-Gunn, Andrew John; Villa, Alberto Enrique; Buzalaf, Marília Rabelo Afonso

2011-01-01

Contemporary biological markers assess present, or very recent, exposure to fluoride: fluoride concentrations in blood, bone surface, saliva, milk, sweat and urine have been considered. A number of studies relating fluoride concentration in plasma to fluoride dose have been published, but at present there are insufficient data on plasma fluoride concentrations across various age groups to determine the 'usual' concentrations. Although bone contains 99% of the body burden of fluoride, attention has focused on the bone surface as a potential marker of contemporary fluoride exposure. From rather limited data, the ratio surface-to-interior concentration of fluoride may be preferred to whole bone fluoride concentration. Fluoride concentrations in the parotid and submandibular/sublingual ductal saliva follow the plasma fluoride concentration, although at a lower concentration. At present, there are insufficient data to establish a normal range of fluoride concentrations in ductal saliva as a basis for recommending saliva as a marker of fluoride exposure. Sweat and human milk are unsuitable as markers of fluoride exposure. A proportion of ingested fluoride is excreted in urine. Plots of daily urinary fluoride excretion against total daily fluoride intake suggest that daily urinary fluoride excretion is suitable for predicting fluoride intake for groups of people, but not for individuals. While fluoride concentrations in plasma, saliva and urine have some ability to predict fluoride exposure, present data are insufficient to recommend utilizing fluoride concentrations in these body fluids as biomarkers of contemporary fluoride exposure for individuals. Daily fluoride excretion in urine can be considered a useful biomarker of contemporary fluoride exposure for groups of people, and normal values have been published. Copyright © 2011 S. Karger AG, Basel.

Elevated major ion concentrations inhibit larval mayfly growth and development.

PubMed

Johnson, Brent R; Weaver, Paul C; Nietch, Christopher T; Lazorchak, James M; Struewing, Katherine A; Funk, David H

2015-01-01

Anthropogenic disturbances, including those from developing energy resources, can alter stream chemistry significantly by elevating total dissolved solids. Field studies have indicated that mayflies (Order Ephemeroptera) are particularly sensitive to high total dissolved solids. In the present study, the authors measured 20-d growth and survivorship of larval Neocloeon triangulifer exposed to a gradient of brine salt (mixed NaCl and CaCl2 ) concentrations. Daily growth rates were reduced significantly in all salt concentrations above the control (363 µS cm(-1) ) and larvae in treatments with specific conductance >812 µS cm(-1) were in comparatively earlier developmental stages (instars) at the end of the experiment. Survivorship declined significantly when specific conductance was >1513 µS cm(-1) and the calculated 20-d 50% lethal concentration was 2866 µS cm(-1) . The present study's results provide strong experimental evidence that elevated ion concentrations similar to those observed in developing energy resources, such as oil and gas drilling or coal mining, can adversely affect sensitive aquatic insect species. © 2014 SETAC.

Concentration Dependent Electrical Transport Properties of Ni-Cr Binary Alloys

NASA Astrophysics Data System (ADS)

Suthar, P. H.; Khambholja, S. G.; Thakore, B. Y.; Gajjar, P. N.; Jani, A. R.

2011-07-01

The concentration dependent electrical transport properties viz. electrical resistivity and thermal conductivity of liquid Ni-Cr alloys are computed at 1400 K temperature. The electrical resistivity has been studied according to Faber-Ziman model in wide range of Cr concentration. In the present work, the electron-ion interaction is incorporated through our well tested local model potential with screening function due to Sarkar et al.. [S] along with the Hartree [H] dielectric function. Good agreement is achieved between the presently calculated results of resistivity as well as thermal conductivity with the experimental data found in the literature, confirming the applicability of model potential and Faber-Ziman model for such a study.

Computation of HORRAT values.

PubMed

McClure, Foster D; Lee, Jung-Keun

2003-01-01

The formula for the Horwitz ratio (HORRAT) as presented in the Study Director's Manual of AOAC INTERNATIONAL is applicable only when the concentration is in the unit/unit form (e.g., microg/microg, g/g, etc.). When the analyte concentration is a trace or mass fraction amount (e.g., microg/g), the formula generates incorrect HORRAT values. Alternative calculation procedures are presented to circumvent such problems.

Effects of nitric oxide and nitrogen dioxide on bacterial growth

NASA Technical Reports Server (NTRS)

Mancinelli, R. L.; Mckay, C. P.

1983-01-01

While it is generally thought that the bactericidal effects of NO and NO2 derive from their reaction with water to form nitrous and nitric acids (Shank et al., 1962), this appears to be true only at high concentrations. The data presented here suggest that at low NO and NO2 concentrations, acids are not present in high enough concentrations to act as toxic agents. Reference is made to a study by Grant et al. (1979), which found that exposing acid forest soil to 1 ppm of NO2 did not cause the soil pH to drop. The results presented here show that at low concentrations of NO and NO2, the NO is bacteriostatic for some organisms and not for others, whereas NO2 may protect some bacteria from the inhibitory effects of NO. Since it has been shown that bacteria can divide while airborne (Dimmick et al., 1979), the present results suggest that NO at the low concentrations found in the atmosphere can select for resistant bacteria in the air and affect the viable airborne bacterial population.

Analysis of Mobile Source Air Toxics (MSATS)–Near-Road VOC and CarbonylConcentrations

EPA Science Inventory

This presentation examines data from a year-long study of measured near-road mobile source air toxic (MSAT) concentrations and compares these data with modeled 2005 National Air Toxic Assessment (NATA) results. Field study measurements were collected during a field campaign in ...

Dependence of future mortality changes on global CO2 concentrations: A review.

PubMed

Lee, Jae Young; Choi, Hayoung; Kim, Ho

2018-05-01

The heterogeneity among previous studies of future mortality projections due to climate change has often hindered comparisons and syntheses of resulting impacts. To address this challenge, the present study introduced a novel method to normalize the results from projection studies according to different baseline and projection periods and climate scenarios, thereby facilitating comparison and synthesis. This study reviewed the 15 previous studies involving projected climate change-related mortality under Representative Concentration Pathways. To synthesize their results, we first reviewed the important study design elements that affected the reported results in previous studies. Then, we normalized the reported results by CO 2 concentration in order to eliminate the effects of the baseline period, projection period, and climate scenario choices. For twenty-five locations worldwide, the normalized percentage changes in temperature-attributable mortality per 100 ppm increase in global CO 2 concentrations ranged between 41.9% and 330%, whereas those of total mortality ranged between 0.3% and 4.8%. The normalization methods presented in this work will guide future studies to provide their results in a normalized format and facilitate research synthesis to reinforce our understanding on the risk of climate change. Copyright © 2018 Elsevier Ltd. All rights reserved.

Persistent organic pollutants and inorganic elements in the Balearic shearwater Puffinus mauretanicus wintering off Portugal.

PubMed

Costa, R A; Torres, J; Vingada, J V; Eira, C

2016-07-15

This study presents the first data on trace element and organic pollutant concentrations in the Critically Endangered Balearic shearwater Puffinus mauretanicus collected in 2010 and 2011 in Portugal. Trace element levels were below the threshold levels for adverse effects on birds, despite the Hg concentrations in feathers (4.35μg·g-1ww). No significant differences were detected between individuals from 2010 and 2011 except for Se concentrations in liver, feathers and muscle (higher in 2010) and Ag in liver and muscle (higher in 2011). No significant differences were detected in total concentrations of organochlorine compounds in Balearic shearwaters between years, although PCB congeners -101 and -180 presented higher concentrations in individuals from 2010. The PCB congeners -138, -153 and -180, and 4.4-DDE were detected in all individuals. This study on toxic elements and organic pollutants in wintering Balearic shearwaters provides baseline data from which deviations can be detected in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative study on conventional, ultrasonication and microwave assisted extraction of γ-oryzanol from rice bran.

PubMed

Kumar, Pramod; Yadav, Devbrat; Kumar, Pradyuman; Panesar, Paramjeet Singh; Bunkar, Durga Shankar; Mishra, Diwaker; Chopra, H K

2016-04-01

In present study, conventional, ultrasonic and microwave assisted extraction methods were compared with the aim of optimizing best fitting solvent and method, solvent concentration and digestion time for high yield of γ-oryzanol from rice bran. Petroleum ether, hexane and methanol were used to prepare extracts. Extraction yield were evaluated for giving high crude oil yield, total phenolic content (TPC) and γ-oryzanol content. Gas chromatography-mass spectrophotometry was used for the determination of γ-oryzanol concentration. The highest concentration of γ-oryzanol was detected in methanolic extracts of microwave treatment (85.0 ppm) followed by ultrasonication (82.0 ppm) and conventional extraction method (73.5 ppm). Concentration of γ-oryzanol present in the extracts was found to be directly proportional to the total phenolic content. A combination of 80 % methanolic concentration and 55 minutes digestion time of microwave treatment yielded the best extraction method for TPC and thus γ-oryzanol (105 ppm).

Radium concentration factors and their use in health and environmental risk assessment

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

Meinhold, A.F.; Hamilton, L.D.

1991-12-31

Radium is known to be taken up by aquatic animals, and tends to accumulate in bone, shell and exoskeleton. The most common approach to estimating the uptake of a radionuclide by aquatic animals for use in health and environmental risk assessments is the concentration factor method. The concentration factor method relates the concentration of a contaminant in an organism to the concentration in the surrounding water. Site specific data are not usually available, and generic, default values are often used in risk assessment studies. This paper describes the concentration factor method, summarizes some of the variables which may influence themore » concentration factor for radium, reviews reported concentration factors measured in marine environments and presents concentration factors derived from data collected in a study in coastal Louisiana. The use of generic default values for the concentration factor is also discussed.« less

Radium concentration factors and their use in health and environmental risk assessment

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

Meinhold, A.F.; Hamilton, L.D.

1991-01-01

Radium is known to be taken up by aquatic animals, and tends to accumulate in bone, shell and exoskeleton. The most common approach to estimating the uptake of a radionuclide by aquatic animals for use in health and environmental risk assessments is the concentration factor method. The concentration factor method relates the concentration of a contaminant in an organism to the concentration in the surrounding water. Site specific data are not usually available, and generic, default values are often used in risk assessment studies. This paper describes the concentration factor method, summarizes some of the variables which may influence themore » concentration factor for radium, reviews reported concentration factors measured in marine environments and presents concentration factors derived from data collected in a study in coastal Louisiana. The use of generic default values for the concentration factor is also discussed.« less

A general circulation model study of the effects of faster rotation rate, enhanced CO2 concentration, and reduced solar forcing: Implications for the faint young sun paradox

NASA Technical Reports Server (NTRS)

Jenkins, Gregory S.

1993-01-01

Solar energy at the top of the atmosphere (solar constant), rotation rate, and carbon dioxide (CO2) may have varied significantly over Earth's history, especially during the earliest times. The sensitivity of a general circulation model to faster rotation, enhanced CO2 concentration, and reduced solar constant is presented. The control simulation of this study has a solar constant reduced by 10% the present amount, zero land fraction using a swamp ocean surface, CO2 concentrations of 330 ppmv, present-day rotation rate, and is integrated under mean diurnal and seasonal solar forcing. Four sensitivity test are performed under zero land fraction and reduced solar constant conditions by varying the earth's rotation rate atmospheric CO2 concentration and solar constant. The global mean sea surface temperatures (SSTs) compared to the control simulation: were 6.6 K to 12 K higher than the control's global mean temperature of 264.7 K. Sea ice is confined to higher latitudes in each experiment compared to the control, with ice-free areas equatorward of the subtropics. The warm SSTs are associated with a 20% reduction in clouds for the rotation rate experiments and higher CO2 concentrations in the other experiments. These results are in contrast to previous studies that have used energy balance and radiative convective models. Previous studies required a much larger atmospheric CO2 increase to prevent an ice-covered Earth. The results of the study, suggest that because of its possible feedback with clouds, the general circulation of the atmosphere should be taken into account in understanding the climate of early Earth. While higher CO2 concentrations are likely in view of the results, very large atmospheric CO2 concentrations may not be necessary to counterbalance the lower solar constant that existed early in Earth's history.

Potential Influence of Perchlorate on Heavy Metals and Organic Carbon in Serpentine Soil; Implications for Martian Regolith

NASA Astrophysics Data System (ADS)

Oze, C.; Kumarathilaka, P. R.; Indraratne, S.; Vithanage, M. S.

2015-12-01

Prasanna Kumarathilaka Chemical and Environmental Systems Modeling Research Group, National Institute of Fundamental Studies, Kandy, Sri LankaPerchlorate (ClO4-) concentrations as high as 1 Wt.% have been reported in Martian regolith. Perchlorate is a strong oxidizer capable of accelerating heavy and/or trace metal release into regolith/soil and reacting with organic matter/compounds (if present). Here, we assess interactions between perchlorate and an analogous Martian regolith (i.e., serpentine soil) to simulate and understand the fate of Mn, Ni and Co and organic carbon. Pre-characterized serpentine soil collected from Sri Lanka was used for this study. Incubation experiments were performed with three perchlorate concentrations (1, 0.75 and 0.5 w/w) and sequential and single extractions assessed solid phase metal fractionation in serpentine sediments after 3 weeks and 1 year, respectively. Additionally, total organic carbon (TOC) of the residues were analyzed. These experiments demonstrate a high release of Mn compared to Ni and Co. Metal concentrations in exchangeable and bioavailable fractions increased with increasing perchlorate concentrations. Exchangeable Ni, Mn and Co increased 5.9, 69.6 and 44.6% and bioavailable Ni, Mn and Co increased 5.5, 92.3 and 72.8%, respectively, after 1 year compared to 3 weeks. Additionally, TOC decreased with increasing perchlorate concentration. For example, TOC decreased by 14.3% after 1 year compared to a 3 week incubation period. Overall, this study confirms the accelerated release of metals and the removal of organic carbon with increasing perchlorate concentrations. Furthermore, this study illustrates how perchlorate may present additional challenges to current Martian life studies and the future human habitation of Mars.Prasanna Kumarathilaka Chemical and Environmental Systems Modeling Research Group, National Institute of Fundamental Studies, Kandy, Sri LankaPerchlorate (ClO4-) concentrations as high as 1 Wt.% have been reported in Martian regolith. Perchlorate is a strong oxidizer capable of accelerating heavy and/or trace metal release into regolith/soil and reacting with organic matter/compounds (if present). Here, we assess interactions between perchlorate and an analogous Martian regolith (i.e., serpentine soil) to simulate and understand the fate of Mn, Ni and Co and organic carbon. Pre-characterized serpentine soil collected from Sri Lanka was used for this study. Incubation experiments were performed with three perchlorate concentrations (1, 0.75 and 0.5 w/w) and sequential and single extractions assessed solid phase metal fractionation in serpentine sediments after 3 weeks and 1 year, respectively. Additionally, total organic carbon (TOC) of the residues were analyzed. These experiments demonstrate a high release of Mn compared to Ni and Co. Metal concentrations in exchangeable and bioavailable fractions increased with increasing perchlorate concentrations. Exchangeable Ni, Mn and Co increased 5.9, 69.6 and 44.6% and bioavailable Ni, Mn and Co increased 5.5, 92.3 and 72.8%, respectively, after 1 year compared to 3 weeks. Additionally, TOC decreased with increasing perchlorate concentration. For example, TOC decreased by 14.3% after 1 year compared to a 3 week incubation period. Overall, this study confirms the accelerated release of metals and the removal of organic carbon with increasing perchlorate concentrations. Furthermore, this study illustrates how perchlorate may present additional challenges to current Martian life studies and the future human habitation of Mars.

Ambient changes in tracer concentrations from a multilevel monitoring system in Basalt

USGS Publications Warehouse

Bartholomay, Roy C.; Twining, Brian V.; Rose, Peter E.

2014-01-01

Starting in 2008, a 4-year tracer study was conducted to evaluate ambient changes in groundwater concentrations of a 1,3,6-naphthalene trisulfonate tracer that was added to drill water. Samples were collected under open borehole conditions and after installing a multilevel groundwater monitoring system completed with 11 discrete monitoring zones within dense and fractured basalt and sediment layers in the eastern Snake River aquifer. The study was done in cooperation with the U.S. Department of Energy to test whether ambient fracture flow conditions were sufficient to remove the effects of injected drill water prior to sample collection. Results from thief samples indicated that the tracer was present in minor concentrations 28 days after coring, but was not present 6 months after coring or 7 days after reaming the borehole. Results from sampling the multilevel monitoring system indicated that small concentrations of the tracer remained in 5 of 10 zones during some period after installation. All concentrations were several orders of magnitude lower than the initial concentrations in the drill water. The ports that had remnant concentrations of the tracer were either located near sediment layers or were located in dense basalt, which suggests limited groundwater flow near these ports. The ports completed in well-fractured and vesicular basalt had no detectable concentrations.

EVALUATING THE EFFECTS OF NEAR ROAD SOLID AND ...

EPA Pesticide Factsheets

Public health concerns for populations living, working and going to school near high-traffic roadways has increased substantially in recent years. Air quality measurement studies indicate high pollutant concentrations can occur near these large roads, impacting population exposures and health effects. Roadside features have been shown to alter pollutant transport and dispersion from the road, affecting near-road concentrations and exposures for nearby populations. Air quality, wind tunnel and tracer gas measurement studies have identified the potential for noise barriers and roadside vegetation to reduce near-road air pollution concentrations, under some conditions by over 50 percent. However, some roadside conditions have been shown to result in increased downwind pollutant concentrations. The data from these studies have been used to develop and evaluate air dispersion model algorithms to simulate pollutant transport and dispersion around and over these features. This presentation will provide an overview of field and wind tunnel studies which have investigated how roadside features alter near-road air quality, how these studies have led to the development of dispersion model algorithms, and recommendations on the design and location of these features to maximize opportunities for pollution reduction and minimize potential increases in near-road pollutant concentrations. Presentation for the CRC MSAT workshop; requested by organizing committee and OTAQ

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.

Evaluation of constant current alternating current iontophoresis for transdermal drug delivery.

PubMed

Yan, Guang; Li, S Kevin; Higuchi, William I

2005-12-10

Previous studies in our laboratory have demonstrated that alternating current (AC) iontophoresis can significantly decrease skin electric resistance and enhance the transport of charged permeants across skin. Flux variability of neutral permeants during AC iontophoresis was also found to be less than that of conventional direct current (DC) iontophoresis. The objectives of the present study were to evaluate flux enhancement of constant current AC transdermal iontophoresis and compare the AC flux with that of constant current DC iontophoresis. Iontophoresis studies of AC amplitude of 1, 2, and 5 mA were conducted in side-by-side diffusion cells with donor solution of 0.015, 0.15, and 1.0 M tetraethylammonium (TEA) chloride and receiver solution of phosphate buffered saline (PBS) using human epidermal membrane (HEM). Conventional constant current DC iontophoresis of 0.2 mA was also performed under similar conditions. TEA and mannitol were the model permeants. The following are the major findings in the present study. The flux of TEA increased proportionally with the AC current for all three TEA chloride concentrations and at the AC frequency used in the present study. When the permeant and its counter ion were the only ionic species in the donor chamber, the fluxes during DC iontophoresis were weakly dependent of its donor concentration. The fluxes of TEA during constant current AC iontophoresis were moderately related to the donor concentration with the highest TEA flux observed under the 1.0 M TEA chloride condition although the relationship between flux and donor concentration was not linear. A trend of decreasing electroosmotic transport with increasing donor TEA chloride concentration was observed with significant sample-to-sample variability during DC iontophoresis. Mannitol permeability was also observed to decrease with increasing TEA chloride concentration in the donor under the AC conditions, but data variability under AC was significantly smaller than that under DC. The results in the present study indicate that constant current AC iontophoresis under conditions tolerable to human (2 and 5 mA) can provide predictable fluxes that were lower than but of comparable magnitude as those of conventional constant current DC iontophoresis (0.2 mA).

Alpha-fetoprotein is present in the fetal fluids and is increased in plasma of mares with experimentally induced ascending placentitis.

PubMed

Canisso, Igor F; Ball, Barry A; Scoggin, Kirsten E; Squires, Edward L; Williams, Neil M; Troedsson, Mats H

2015-03-01

The objectives of this study were to: (i) determine alpha-fetoprotein (AFP) concentrations in fetal fluids (FF), and (ii) compare plasma concentrations of AFP in mares with placentitis (n=17) and gestationally age-matched control mares (n=17). Fetal fluid sampling (FFS, n=7/group) was performed at 0, 5 and 12 days post inoculation (DPI) or until abortion. Plasma was harvested daily for 12 days or until abortion. Placentitis was induced via intracervical inoculation of Streptococcus equi ssp. zooepidemicus. Proteins present in the FF were resolved by 1D-SDS-PAGE, and immunoblotting was used to detect the presence of AFP in fetal fluids. Concentrations of AFP in FF and plasma were determined with a chemiluminescence immunoassay. Mixed models for DPI, and for days from abortion (DFA) were used to analyze plasma concentrations of AFP. A protein band ∼68kDa consistent with the AFP size was present in all samples of fetal fluids examined. Immunoblotting for AFP revealed a single protein band (∼68kDa) in all samples. Concentrations of AFP in FF appeared higher than those in maternal plasma. There were effects of time (DPI p<0.0001; DFA p=0.0002) and time-by-group interactions (DPI*Group p<0.06; Group*DFA p<0.001). This study confirmed that AFP is present in the FF of mares during the third trimester of pregnancy. Experimentally induced placentitis was associated with an elevation in maternal plasma concentrations of AFP. Copyright © 2015 Elsevier B.V. All rights reserved.

Status of groundwater quality in the Santa Barbara Study Unit, 2011: California GAMA Priority Basin Project

USGS Publications Warehouse

Davis, Tracy A.; Kulongoski, Justin T.

2016-10-03

Groundwater quality in the 48-square-mile Santa Barbara study unit was investigated in 2011 as part of the California State Water Resources Control Board’s Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project. The study unit is mostly in Santa Barbara County and is in the Transverse and Selected Peninsular Ranges hydrogeologic province. The GAMA Priority Basin Project is carried out by the U.S. Geological Survey in collaboration with the California State Water Resources Control Board and Lawrence Livermore National Laboratory.The GAMA Priority Basin Project was designed to provide a statistically unbiased, spatially distributed assessment of the quality of untreated groundwater in the primary aquifer system of California. The primary aquifer system is defined as that part of the aquifer corresponding to the perforation interval of wells listed in the California Department of Public Health database for the Santa Barbara study unit. This status assessment is intended to characterize the quality of groundwater resources in the primary aquifer system of the Santa Barbara study unit, not the treated drinking water delivered to consumers by water purveyors.The status assessment for the Santa Barbara study unit was based on water-quality and ancillary data collected in 2011 by the U.S. Geological Survey from 23 sites and on water-quality data from the California Department of Public Health database for January 24, 2008–January 23, 2011. The data used for the assessment included volatile organic compounds; pesticides; pharmaceutical compounds; two constituents of special interest, perchlorate and N-nitrosodimethylamine (NDMA); and naturally present inorganic constituents, such as major ions and trace elements. Relative-concentrations (sample concentration divided by the health- or aesthetic-based benchmark concentration) were used to evaluate groundwater quality for those constituents that have federal or California regulatory and non-regulatory benchmarks for drinking-water quality. For inorganic, organic, and special-interest constituents, a relative-concentration greater than 1.0 indicates a concentration greater than the benchmark and is classified as high. Inorganic constituents are classified as moderate if relative-concentrations are greater than 0.5 and less than or equal to 1.0 and are classified as low if relative-concentrations are less than or equal to 0.5. For organic and special-interest constituents, the boundary between moderate and low relative-concentrations was set at 0.1.Aquifer-scale proportion was used as the primary metric for evaluating regional-scale groundwater quality. High aquifer-scale proportion is defined as the areal percentage of the primary aquifer system with a relative-concentration greater than 1.0 for a particular constituent or class of constituents. Moderate and low aquifer-scale proportions were defined as the areal percentage of the primary aquifer system that had moderate and low relative-concentrations, respectively. Two statistical approaches—grid based and spatially weighted—were used to calculate aquifer-scale proportions for individual constituents and constituent classes. Grid-based and spatially weighted estimates were comparable in this the study (within 90-percent confidence intervals). Grid-based results were selected for use in the status assessment unless, as was observed in a few cases, a grid-based result was zero and the spatially weighted result was not zero, in which case, the spatially weighted result was used.Inorganic constituents that have human-health benchmarks were present at high relative-concentrations in 5.3 percent of the primary aquifer system and at moderate concentrations in 32 percent. High aquifer-scale proportions of inorganic constituents primarily were a result of high aquifer-scale proportions of boron (5.3 percent) and fluoride (5.3 percent). Inorganic constituents that have aesthetic-based benchmarks, referred to as secondary maximum contaminant levels, were present at high relative-concentrations in 58 percent of the primary aquifer system and at moderate concentrations in 37 percent. Iron, manganese, sulfate, and total dissolved solids were the inorganic constituents with secondary maximum contaminant levels present at high relative-concentrations.In contrast, organic and special-interest constituents that have health-based benchmarks were not detected at high relative-concentrations in the primary aquifer system. Of the 218 organic constituents analyzed, 10 were detected—9 that had human-health benchmarks. Organic constituents were present at moderate relative-concentrations in 11 percent of the primary aquifer system. The moderate aquifer-scale proportions were a result of moderate relative-concentrations of the volatile organic compounds methyl tert-butyl ether (MTBE, 11 percent) and 1,2-dichloroethane (5.6 percent). The volatile organic compounds 1,1,1-trichloroethane, 1,1-dichloroethane, bromodichloromethane, chloroform, MTBE, and perchloroethene (PCE); the pesticide simazine; and the special-interest constituent perchlorate were detected at more than 10 percent of the sites in the Santa Barbara study unit. Perchlorate was present at moderate relative-concentrations in 50 percent of the primary aquifer system. Pharmaceutical compounds and NDMA were not detected in the Santa Barbara study unit.

Fluoride concentration in community water and bottled drinking water: a dilemma today.

PubMed

Dhingra, S; Marya, C M; Jnaneswar, A; Kumar, H

2013-01-01

Because of the potential for contamination of municipal water supplies, people appear to be turning to alternative sources for their pure drinking water. The present study analyzed the fluoride concentration in community water and bottled drinking water sold in Faridabad city. A comparative evaluation of fluoride content in community water supply and bottled drinking water was done using ion-selective electrode method. The community water samples were collected from six different areas (i.e. north zone, south zone, east zone, west zone and central zone) in the city from public health water supply taps while bottled drinking water samples were randomly picked from grocery shops or supermarkets. The fluoride concentration in the community water supply in this study ranges from 0.11 to 0.26 mg/L with mean fluoride concentration of 0.17 mg/L. The mean concentration of fluoride in bottled drinking water was 0.06 mg/L. The differences observed between mean of two water samples was statistically significant. The results obtained from the present study clearly state that the fluoride concentration was insufficient in community water supply from all the areas and also was deficient in bottled drinking water sold in Faridabad city. So, Alternative sources of fluorides should be supplemented for optimal dental benefits from the use of fluoride.

Spider peptide toxin lycosin-I induces apoptosis and inhibits migration of prostate cancer cells.

PubMed

Shen, Hongwei; Xie, Yuan; Ye, Senlin; He, Kancheng; Yi, Lu; Cui, Rongrong

2018-05-01

Spider toxins are molecularly diverse and some display not only a strong antibacterial effect but also exhibit significant inhibition of tumor growth and promote tumor cell apoptosis. The aim of the present investigation was to explore different antitumor effects of the spider peptide toxin lycosin-I through different pathways at different concentrations. It was found that by inactivating STAT3 pathway, high concentrations of lycosin-I induce apoptosis in prostate cancer cells and low concentrations of lycosin-I inhibit the migration of prostate cancer cells. This finding provides favorable evidence for further study of the molecular diversity of spider toxins. Impact statement The spider peptide toxin has become an important research topic. These toxins are molecularly diverse and some display not only a strong antibacterial effect but also exhibit significant inhibition of tumor growth and promote tumor cell apoptosis. Inspired by previous studies, the present study aims to investigate the effects of different concentrations of lycosin-I on the invasiveness and apoptosis of human prostate cancer cells. The findings provide favorable evidence for further study of the molecular diversity of spider toxins.

Regional variation in mercury and stable isotopes of red snapper (Lutjanus campechanus) in the northern Gulf of Mexico, USA.

PubMed

Zapp Sluis, Michelle; Boswell, Kevin M; Chumchal, Matthew M; Wells, R J David; Soulen, Brianne; Cowan, James H

2013-02-01

The presence of total mercury (Hg) in fish tissue and the potential associated health risks has become a global concern in marine ecosystems. Few studies have examined basin-scale variation in Hg accumulation in marine ecosystems, and determining if Hg concentrations in fish tissue vary across marine ecosystems is a key monitoring question. The present study evaluated Hg concentrations in red snapper (Lutjanus campechanus) tissue across three regions of the northern Gulf of Mexico (Alabama, Louisiana, and Texas, USA) and between two habitat types (oil and gas platforms and nonplatforms) within each region. Nitrogen (δ(15)N), carbon (δ(13)C), and sulfur (δ(34)S) stable isotopes were used to investigate ecological differences that may affect Hg concentrations among regions and between habitats. Mercury concentrations in red snapper tissue were positively correlated with fish total length. Regional differences in Hg concentrations were significant, with fish collected from Alabama having the highest concentrations and fish collected from Louisiana having the lowest. No significant difference existed in Hg concentrations between habitats, suggesting that association with platforms may not be a significant factor contributing to red snapper Hg concentrations. While δ(15)N did not differ significantly among the three regions, Texas red snapper were more enriched in δ(34)S and depleted in δ(13)C compared with Alabama and Louisiana red snapper. Although the majority of red snapper collected in the present study had Hg concentrations below safe consumption guidelines, regional differences suggest that spatially explicit monitoring programs may be important for basin-wide assessments. Copyright © 2012 SETAC.

Tear copper and its association with liver copper concentrations in six adult ewes.

PubMed Central

Schoster, J V; Stuhr, C; Kiorpes, A

1995-01-01

Tear and liver copper concentrations from 6 clinically healthy adult mixed-breed ewes were measured by Atomic Absorption Electrothermal Atomization (graphite furnace) Spectrometry and Flame Absorption Spectrometry, respectively, 7 times over 227 d to determine if their tears contained copper and if so, whether tear copper concentrations could reliably predict liver copper concentrations. To produce changes in liver copper concentration, the diet was supplemented with copper at concentrations that increased from 23 mg to 45 mg Cu/kg feed/day/sheep during the study. This regimen raised liver copper for all sheep to potentially toxic hepatic tissue concentration of greater than 500 mg/kg dry (DM) matter (tissue). The results of the study showed that copper was present in the tears of all sheep. The mean tear copper concentration showed a positive correlation with liver copper concentration (P = 0.003), increasing from 0.07 mg/kg DM at the start to 0.44 mg/kg DM at the end of the study, but could not reliably predict liver copper concentration (R2 = 0.222). PMID:7648525

Viscosity studies of water based magnetite nanofluids

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

Anu, K.; Hemalatha, J.

2016-05-23

Magnetite nanofluids of various concentrations have been synthesized through co-precipitation method. The structural and topographical studies made with the X-Ray Diffractometer and Atomic Force Microscope are presented in this paper. The density and viscosity studies for the ferrofluids of various concentrations have been made at room temperature. The experimental viscosities are compared with theoretical values obtained from Einstein, Batchelor and Wang models. An attempt to modify the Rosensweig model is made and the modified Rosensweig equation is reported. In addition, new empirical correlation is also proposed for predicting viscosity of ferrofluid at various concentrations.

Linking ground-water age and chemistry data along flow paths: Implications for trends and transformations of nitrate and pesticides

USGS Publications Warehouse

Tesoriero, A.J.; Saad, D.A.; Burow, K.R.; Frick, E.A.; Puckett, L.J.; Barbash, J.E.

2007-01-01

Tracer-based ground-water ages, along with the concentrations of pesticides, nitrogen species, and other redox-active constituents, were used to evaluate the trends and transformations of agricultural chemicals along flow paths in diverse hydrogeologic settings. A range of conditions affecting the transformation of nitrate and pesticides (e.g., thickness of unsaturated zone, redox conditions) was examined at study sites in Georgia, North Carolina, Wisconsin, and California. Deethylatrazine (DEA), a transformation product of atrazine, was typically present at concentrations higher than those of atrazine at study sites with thick unsaturated zones but not at sites with thin unsaturated zones. Furthermore, the fraction of atrazine plus DEA that was present as DEA did not increase as a function of ground-water age. These findings suggest that atrazine degradation occurs primarily in the unsaturated zone with little or no degradation in the saturated zone. Similar observations were also made for metolachlor and alachlor. The fraction of the initial nitrate concentration found as excess N2 (N2 derived from denitrification) increased with ground-water age only at the North Carolina site, where oxic conditions were generally limited to the top 5??m of saturated thickness. Historical trends in fluxes to ground water were evaluated by relating the times of recharge of ground-water samples, estimated using chlorofluorocarbon concentrations, with concentrations of the parent compound at the time of recharge, estimated by summing the molar concentrations of the parent compound and its transformation products in the age-dated sample. Using this approach, nitrate concentrations were estimated to have increased markedly from 1960 to the present at all study sites. Trends in concentrations of atrazine, metolachlor, alachlor, and their degradates were related to the timing of introduction and use of these compounds. Degradates, and to a lesser extent parent compounds, were detected in ground water dating back to the time these compounds were introduced.

Semiconductor Sensors for Studying the Heterogeneous Destruction of Ozone at Low Concentrations

NASA Astrophysics Data System (ADS)

Obvintseva, L. A.; Sharova, T. B.; Avetisov, A. K.; Sukhareva, I. P.

2018-06-01

Prospects for the use of semiconductor resistive sensors in studies of the heterogeneous destruction of ozone at low concentrations (5-400 μg/m3) were shown. The influence of various factors (sensor temperature, gas flow rate, ozone concentration) on the results of ozone concentration measurements with sensors of various types was studied. Methods for forming a sensitive layer of In2O3(3% Fe2O3) sensors with specified parameters of calibration curves were proposed. The optimum conditions for the operation of sensors in a flow mode were formulated. The results of the study of heterogeneous destruction of ozone on microfiber polymer and natural disperse (sand, coals) materials obtained by the developed method were presented.

On the role of ice-nucleating aerosol in the formation of ice particles in tropical mesoscale convective systems

NASA Astrophysics Data System (ADS)

Ladino, Luis A.; Korolev, Alexei; Heckman, Ivan; Wolde, Mengistu; Fridlind, Ann M.; Ackerman, Andrew S.

2017-02-01

Over the decades, the cloud physics community has debated the nature and role of aerosol particles in ice initiation. The present study shows that the measured concentration of ice crystals in tropical mesoscale convective systems exceeds the concentration of ice nucleating particles (INPs) by several orders of magnitude. The concentration of INPs was assessed from the measured aerosol particle concentration in the size range of 0.5 to 1 µm. The observations from this study suggest that primary ice crystals formed on INPs make only a minor contribution to the total concentration of ice crystals in tropical mesoscale convective systems. This is found by comparing the predicted INP number concentrations with in situ ice particle number concentrations. The obtained measurements suggest that ice multiplication is the likely explanation for the observed high concentrations of ice crystals in this type of convective system.

Miscibility and crystallization behavior of poly (3-hydroxybutyrate) and poly (ethylene glycol) blends studied by positron annihilation spectroscopy

NASA Astrophysics Data System (ADS)

Abdel-Hady, E. E.; Abdel-Hamed, M. O.; Hammam, A. M.

2011-01-01

Positron annihilation Lifetime (PAL) spectroscopy has been used to study the effect of PEG concentrations on the free volume properties of PHB. The data revealed that the ortho-positronium (o-Ps) lifetime τPs increases with 20% increase in concentration, decrease as the concentration increases to 40%, then rapid increase at 50% concentration of PEG. The o-Ps intensity, I3, shows a linear dependence as the concentration increases with a discontinuity at 20% concentration of PEG. Furthermore, the results presented and discussed in this work show that the PHB and PEG are miscible up to 40% of PEG but greater than 40%, the blend is immiscible. In addition, the mechanical properties of PHB are well improved by the addition of PEG with a low concentration up to 20%, while at higher concentration the blend becomes waxy.

On the role of ice-nucleating aerosol in the formation of ice particles in tropical mesoscale convective systems

PubMed Central

Ladino, Luis A.; Korolev, Alexei; Heckman, Ivan; Wolde, Mengistu; Fridlind, Ann M.; Ackerman, Andrew S.

2018-01-01

Over decades, the cloud physics community has debated the nature and role of aerosol particles in ice initiation. The present study shows that the measured concentration of ice crystals in tropical mesoscale convective systems exceeds the concentration of ice nucleating particles (INPs) by several orders of magnitude. The concentration of INPs was assessed from the measured aerosol particles concentration in the size range of 0.5 to 1 µm. The observations from this study suggest that primary ice crystals formed on INPs make only a minor contribution to the total concentration of ice crystals in tropical mesoscale convective systems. This is found by comparing the predicted INP number concentrations with in-situ ice particle number concentrations. The obtained measurements suggest that ice multiplication is the likely explanation for the observed high concentrations of ice crystals in this type of convective system. PMID:29551842

The association of physical examination abnormalities and carboxyhemoglobin concentrations in 21 dogs trapped in a kennel fire.

PubMed

Ashbaugh, Elizabeth A; Mazzaferro, Elisa M; McKiernan, Brendan C; Drobatz, Kenneth J

2012-06-01

To evaluate physical examination findings and their association with carboxyhemoglobin (COHb) concentrations in 21 dogs that were exposed to smoke during a kennel fire. Twenty-one dogs were exposed to a kennel fire. Physical exam findings, presenting, and posttherapy COHb concentrations as well as therapeutic interventions were evaluated. COHb concentrations upon presentation were increased in all smoke inhalation exposed dogs. These dogs were compared to a small set of clinically normal staff-owned dogs who were not exposed to fire. Physical parameters significantly associated with higher COHb concentrations included lower body temperature, increased respiratory effort, abnormal respiratory auscultation, altered neurologic status, and length of hospital stay. Oxygen therapy resulted in a more rapid decline in COHb concentrations although 5 dogs still had mildly increased COHb concentrations 24-hour postadmission. This study describes the relationship of admitting clinical findings of dogs exposed to a kennel fire with their initial blood COHb concentrations. It also describes the resolution of increased COHb concentrations with use of oxygen therapy and hospitalization. Additionally, COHb concentrations for a control group of dogs was evaluated and compared to the dogs exposed to smoke inhalation. © Veterinary Emergency and Critical Care Society 2012.

Cognitive impairment related changes in the elemental concentration in the brain of old rat

NASA Astrophysics Data System (ADS)

Serpa, R. F. B.; de Jesus, E. F. O.; Anjos, M. J.; Lopes, R. T.; do Carmo, M. G. T.; Rocha, M. S.; Rodrigues, L. C.; Moreira, S.; Martinez, A. M. B.

2006-11-01

In order to evaluate the elemental concentration as a function of learning and memory deficiency, six different structures of the brain were analyzed by total reflection X-ray fluorescence spectrometry with synchrotron radiation (SR-TXRF). To evaluate the cognitive processes, the animals were tested in an adaptation of the Morris water maze. After the test, the animals were divided into two groups: cognitively healthy (control group) and cognitively impaired. The measurements were carried out at XRF beam line at Light Synchrotron Brazilian laboratory, Campinas, Brazil. The following elements were identified: Al, P, S, Cl, K, Ca, Ti, Cr, Fe, Cu, Zn, Br and Rb. K concentration was higher in all regions of the brain studied for control group than the cognitively impaired group. Moreover, the control group presented higher levels for P and Fe in the entorhinal cortex, in the temporal cortex (only P), in the hypothalamus and in the thalamus, than the cognitively impaired group. Br concentration in the animals which presented cognitive impairment was three times larger in the hypothalamus and thalamus, twice larger in temporal cortex and higher in visual cortex than the cognitively healthy group. Cu was more remarkable in the hippocampus and hypothalamus from the animals with cognitive impairment than the control group. We observed that the cognitively impaired group presented highest concentrations of Br and Cu in certain areas than the control group, on the other hand, this group presented highest levels of K for all brain areas studied.

Low-cost point-focus solar concentrator, phase 1

NASA Technical Reports Server (NTRS)

Nelson, E. V.; Derbidge, T. C.; Erskine, D.; Maraschin, R. A.; Niemeyer, W. A.; Matsushita, M. J.; Overly, P. T.

1979-01-01

The results of the preliminary design study for the low cost point focus solar concentrator (LCPFSC) development program are presented. A summary description of the preliminary design is given. The design philosophy used to achieve a cost effective design for mass production is described. The concentrator meets all design requirements specified and is based on practical design solutions in every possible way.

Systems Studies of DDT Transport

ERIC Educational Resources Information Center

Harrison, H. L.; And Others

1970-01-01

Major consequences of present and additional environmental quantities of DDT pesticide are predictable by mathematical models of transport, accumulation and concentration mechanisms in the Wisconsin regional ecosystem. High solubility and stability produce increased DDT concentrations at high organism trophic levels within world biosphere…

Study of Interaction between Cadmium and Bovine Serum Albumin with UV-Vis Spectrocopy Approach

NASA Astrophysics Data System (ADS)

Suhartono, E.; Thalib, I.; Aflanie, I.; Noor, Z.; Idroes, R.

2018-05-01

This study aims to explain the interaction of cadmium (Cd) with serum albumin through visible light (UV-Vis) spectroscopy approach. This study is an in vitro experimental study using Cd with several concentrations and Bovine Serum Albumin (BSA). Each solution was then incubated for 10 min at 37°C, and measured the absorbance at 220-300 nm. The absorbance data is then presented in graphical form. From the graph, a linear equation will appear to calculate the value of metal binding constants (K) to proteins. Also, in this present study we analsyed the ratio between A220 and A220 to identify changes in the protein region especially tyrosine and peptide bonds. The results show that the addition of Cd in different concentrations could increase the absorbance with a constant value (K) = 1.634. Based on the result, it seems the addition of Cd in different concentrations will lead the reaction to form BSA-Cd. Also, the result shows that the ration of A220/A280 were decreased with the increasing of Cd concentration. In conclusion, the addition of Cd could interact and changes the protein structure in BSA.

Triazole-induced toxicity in developing rare minnow (Gobiocypris rarus) embryos.

PubMed

Zhu, Bin; Liu, Lei; Gong, Yu-Xin; Ling, Fei; Wang, Gao-Xue

2014-12-01

Using rare minnow (Gobiocypris rarus) at early-life stages as experimental models, the developmental toxicity of five widely used triazole fungicides (myclobutanil, fluconazole, flusilazole, triflumizole, and epoxiconazole) were investigated following exposure to 1-15 mg/L for 72 h. Meanwhile, morphological parameters (body length, body weight, and heart rate), enzyme activities (superoxide dismutase (SOD), glutathione S-transferase (GST), adenosine triphosphatase (ATPase), and acetyl cholinesterase (AChE)), and mRNA levels (hsp70, mstn, mt, apaf1, vezf1, and cyp1a) were also recorded following exposure to 0.2, 1.0, and 5.0 mg/L for 72 h. Results indicated that increased malformation and mortality, decreased body length, body weight, and heart rate provide a concentration-dependent pattern; values of 72 h LC50 (median lethal concentration) and EC50 (median effective concentration) ranged from 3 to 12 mg/L. Most importantly, the results of the present study suggest that even at the lowest concentration, 0.2 mg/L, five triazole fungicides also caused notable changes in enzyme activities and mRNA levels. Overall, the present study points out that those five triazole fungicides are highly toxic to the early development of G. rarus embryos. The information presented in this study will be helpful in better understanding the toxicity induced by triazole fungicides in fish embryos.

A Study of First-Year Chemistry Students' Understanding of Solution Concentration at the Tertiary Level

ERIC Educational Resources Information Center

de Berg, Kevin

2012-01-01

This paper reports on students' understanding of sugar concentration in aqueous solutions presented in two different modes: a visual submicroscopic mode for particles and a verbal mode referring to macroscopic amounts of sugar. One hundred and forty-five tertiary college students studying some form of first-year chemistry participated in the…

The Asian clam Corbicula fluminea as a biomonitor of trace element contamination: Accounting for different sources of variation using an hierarchical linear model

USGS Publications Warehouse

Shoults-Wilson, W. A.; Peterson, J.T.; Unrine, J.M.; Rickard, J.; Black, M.C.

2009-01-01

In the present study, specimens of the invasive clam, Corbicula fluminea, were collected above and below possible sources of potentially toxic trace elements (As, Cd, Cr, Cu, Hg, Pb, and Zn) in the Altamaha River system (Georgia, USA). Bioaccumulation of these elements was quantified, along with environmental (water and sediment) concentrations. Hierarchical linear models were used to account for variability in tissue concentrations related to environmental (site water chemistry and sediment characteristics) and individual (growth metrics) variables while identifying the strongest relations between these variables and trace element accumulation. The present study found significantly elevated concentrations of Cd, Cu, and Hg downstream of the outfall of kaolin-processing facilities, Zn downstream of a tire cording facility, and Cr downstream of both a nuclear power plant and a paper pulp mill. Models of the present study indicated that variation in trace element accumulation was linked to distance upstream from the estuary, dissolved oxygen, percentage of silt and clay in the sediment, elemental concentrations in sediment, shell length, and bivalve condition index. By explicitly modeling environmental variability, the Hierarchical linear modeling procedure allowed the identification of sites showing increased accumulation of trace elements that may have been caused by human activity. Hierarchical linear modeling is a useful tool for accounting for environmental and individual sources of variation in bioaccumulation studies. ?? 2009 SETAC.

Application of nonparametric regression methods to study the relationship between NO2 concentrations and local wind direction and speed at background sites.

PubMed

Donnelly, Aoife; Misstear, Bruce; Broderick, Brian

2011-02-15

Background concentrations of nitrogen dioxide (NO(2)) are not constant but vary temporally and spatially. The current paper presents a powerful tool for the quantification of the effects of wind direction and wind speed on background NO(2) concentrations, particularly in cases where monitoring data are limited. In contrast to previous studies which applied similar methods to sites directly affected by local pollution sources, the current study focuses on background sites with the aim of improving methods for predicting background concentrations adopted in air quality modelling studies. The relationship between measured NO(2) concentration in air at three such sites in Ireland and locally measured wind direction has been quantified using nonparametric regression methods. The major aim was to analyse a method for quantifying the effects of local wind direction on background levels of NO(2) in Ireland. The method was expanded to include wind speed as an added predictor variable. A Gaussian kernel function is used in the analysis and circular statistics employed for the wind direction variable. Wind direction and wind speed were both found to have a statistically significant effect on background levels of NO(2) at all three sites. Frequently environmental impact assessments are based on short term baseline monitoring producing a limited dataset. The presented non-parametric regression methods, in contrast to the frequently used methods such as binning of the data, allow concentrations for missing data pairs to be estimated and distinction between spurious and true peaks in concentrations to be made. The methods were found to provide a realistic estimation of long term concentration variation with wind direction and speed, even for cases where the data set is limited. Accurate identification of the actual variation at each location and causative factors could be made, thus supporting the improved definition of background concentrations for use in air quality modelling studies. Copyright © 2010 Elsevier B.V. All rights reserved.

Relation between troponin T concentration and mortality in patients presenting with an acute stroke: observational study

PubMed Central

James, P; Ellis, C J; Whitlock, R M L; McNeil, A R; Henley, J; Anderson, N E

2000-01-01

Objective To assess whether a raised serum troponin T concentration would be an independent predictor of death in patients with an acute ischaemic stroke. Design Observational study. Setting Auckland Hospital, Auckland, New Zealand. Subjects All 181 patients with an acute ischaemic stroke admitted over nine months in 1997-8, from a total of 8057 patients admitted to the acute medical service. Main outcome measures Blood samples for measuring troponin T concentration were collected 12-72 hours after admission; other variables previously associated with severity of stroke were also recorded and assessed as independent predictors of inpatient mortality. Results Troponin T concentration was raised (>0.1 μg/l) in 17% (30) of patients admitted with an acute ischaemic stroke. Thirty one patients died in hospital (12/30 (40%) patients with a raised troponin T concentration v 19/151 (13%) patients with a normal concentration (relative risk 3.2 (95% confidence 1.7 to 5.8; P=0.0025)). Of 17 possible predictors of death, assessed in a multivariate stepwise model, only a raised troponin T concentration (P=0.0002), age (P=0.0008), and an altered level of consciousness at presentation (P=0.0074) independently predicted an adverse outcome. Conclusions Serum troponin T concentration at hospital admission is a powerful predictor of mortality in patients admitted with an acute ischaemic stroke. PMID:10834890

Sperm quality in New Zealand: Is the downward trend continuing?

PubMed

Birdsall, Mary A; Peek, John; Valiapan, Sumithra

2015-10-16

To investigate whether the decline in sperm concentration in New Zealand sperm donors observed from 1987 to 2007 continued in the period 2008-2014. A retrospective study from 2008 to 2014. The first semen sample of 285 men presenting as sperm donors in Auckland and Wellington was analysed for sperm concentration, seminal fluid volume and the percentage of motile sperm. These results were compared to results from 1987 to 2007 from the same clinics. The decline in semen volume and sperm concentration observed between 1987 and 2007 did not continue in 2008-2014. Sperm concentration decreased from 1987 until some time between 1997 and 2001, and has remained stable at an average of 62x106/ml between 2001 and 2014. Sperm motility declined significantly (8%) in the period 2008-2014, but there was no significant change over the total period studied, between 1987 and 2014. After a decline between 1987 and sometime during 1997-2001, the sperm concentration in men presenting as donors remained unchanged between 2002 and 2014, suggesting semen quality has not changed in New Zealand men over the last decade.

High-concentration zeta potential measurements using light-scattering techniques

PubMed Central

Kaszuba, Michael; Corbett, Jason; Watson, Fraser Mcneil; Jones, Andrew

2010-01-01

Zeta potential is the key parameter that controls electrostatic interactions in particle dispersions. Laser Doppler electrophoresis is an accepted method for the measurement of particle electrophoretic mobility and hence zeta potential of dispersions of colloidal size materials. Traditionally, samples measured by this technique have to be optically transparent. Therefore, depending upon the size and optical properties of the particles, many samples will be too concentrated and will require dilution. The ability to measure samples at or close to their neat concentration would be desirable as it would minimize any changes in the zeta potential of the sample owing to dilution. However, the ability to measure turbid samples using light-scattering techniques presents a number of challenges. This paper discusses electrophoretic mobility measurements made on turbid samples at high concentration using a novel cell with reduced path length. Results are presented on two different sample types, titanium dioxide and a polyurethane dispersion, as a function of sample concentration. For both of the sample types studied, the electrophoretic mobility results show a gradual decrease as the sample concentration increases and the possible reasons for these observations are discussed. Further, a comparison of the data against theoretical models is presented and discussed. Conclusions and recommendations are made from the zeta potential values obtained at high concentrations. PMID:20732896

CXCL9 concentrations in cerebrospinal fluid and serum of patients with tick-borne encephalitis.

PubMed

Koper, Olga M; Kamińska, Joanna; Grygorczuk, Sambor; Zajkowska, Joanna; Kemona, Halina

2018-03-01

The aim of our current study was to evaluate cerebrospinal fluid (CSF) and serum CXCL9 concentrations and diagnostic usefulness of this molecule in tick-borne encephalitis (TBE). The study included TBE patients in the acute phase (TBE I) and after 2 weeks of follow-up (TBE II). The control group consisted of patients investigated for suspected central nervous system (CNS) infection, but with normal CSF findings. Concentrations of CXCL9 were measured using enzyme-linked immunosorbent assay (ELISA). Cerebrospinal fluid and serum concentrations of CXCL9 in patients with TBE were significantly higher than in controls ( p < 0.001). This alteration was also observed in the case of the CXCL9 index (I CXCL9 ; CSF CXCL9 concentration divided by serum CXCL9 concentration) ( p < 0.001); moreover, I CXCL9 significantly decreased after 2 weeks ( p < 0.001). This is the first study to evaluate the CSF and serum levels of CXCL9 in subjects with TBE. CXCL9 is a ligand for CXCR3, which was found on all Th1 memory lymphocytes present in the peripheral blood; therefore the elevated concentrations of CXCL9 in TBE patients as compared to the controls might indicate that this chemokine perhaps takes part in the trafficking of Th 1 cells into the CNS. The results presented here support the hypothesis that CXCL9 may play a role in TBE. However, further studies are required to determine whether this protein might be used as a potential tool for the diagnosis and monitoring of inflammation in TBE.

A logical starting point for developing priorities for lizard and snake ecotoxicology: a review of available data.

PubMed

Campbell, Kym Rouse; Campbell, Todd S

2002-05-01

Reptiles, specifically lizards and snakes, usually are excluded from environmental contamination studies and ecological risk assessments. This brief summary of available lizard and snake environmental contaminant data is presented to assist in the development of priorities for lizard and snake ecotoxicology. Most contaminant studies were not conducted recently, list animals found dead or dying after pesticide application, report residue concentrations after pesticide exposure, compare contaminant concentrations in animals from different areas, compare residue concentrations found in different tissues and organs, or compare changes in concentrations over time. The biological significance of the contaminant concentrations is rarely studied. A few recent studies, especially those conducted on modern pesticides, link the contaminant effects with exposure concentrations. Nondestructive sampling techniques for determining organic and inorganic contaminant concentrations in lizards and snakes recently have been developed. Studies that relate exposure, concentration, and effects of all types of environmental contaminants on lizards and snakes are needed. Because most lizards eat insects, studies on the exposure, effects, and accumulation of insecticides in lizards, and their predators, should be a top priority. Because all snakes are upper-trophic-level carnivores, studies on the accumulation and effects of contaminants that are known to bioaccumulate or biomagnify up the food chain should be the top priority.

Pharmacokinetics and Pharmacodynamics of Lysergic Acid Diethylamide in Healthy Subjects.

PubMed

Dolder, Patrick C; Schmid, Yasmin; Steuer, Andrea E; Kraemer, Thomas; Rentsch, Katharina M; Hammann, Felix; Liechti, Matthias E

2017-10-01

Lysergic acid diethylamide (LSD) is used recreationally and in clinical research. The aim of the present study was to characterize the pharmacokinetics and exposure-response relationship of oral LSD. We analyzed pharmacokinetic data from two published placebo-controlled, double-blind, cross-over studies using oral administration of LSD 100 and 200 µg in 24 and 16 subjects, respectively. The pharmacokinetics of the 100-µg dose is shown for the first time and data for the 200-µg dose were reanalyzed and included. Plasma concentrations of LSD, subjective effects, and vital signs were repeatedly assessed. Pharmacokinetic parameters were determined using compartmental modeling. Concentration-effect relationships were described using pharmacokinetic-pharmacodynamic modeling. Geometric mean (95% confidence interval) maximum plasma concentration values of 1.3 (1.2-1.9) and 3.1 (2.6-4.0) ng/mL were reached 1.4 and 1.5 h after administration of 100 and 200 µg LSD, respectively. The plasma half-life was 2.6 h (2.2-3.4 h). The subjective effects lasted (mean ± standard deviation) 8.2 ± 2.1 and 11.6 ± 1.7 h for the 100- and 200-µg LSD doses, respectively. Subjective peak effects were reached 2.8 and 2.5 h after administration of LSD 100 and 200 µg, respectively. A close relationship was observed between the LSD concentration and subjective response within subjects, with moderate counterclockwise hysteresis. Half-maximal effective concentration values were in the range of 1 ng/mL. No correlations were found between plasma LSD concentrations and the effects of LSD across subjects at or near maximum plasma concentration and within dose groups. The present pharmacokinetic data are important for the evaluation of clinical study findings (e.g., functional magnetic resonance imaging studies) and the interpretation of LSD intoxication. Oral LSD presented dose-proportional pharmacokinetics and first-order elimination up to 12 h. The effects of LSD were related to changes in plasma concentrations over time, with no evidence of acute tolerance. NCT02308969, NCT01878942.

Reliability of concentrations of organophosphate pesticide metabolites in serial urine specimens from pregnancy in the Generation R Study.

PubMed

Spaan, Suzanne; Pronk, Anjoeka; Koch, Holger M; Jusko, Todd A; Jaddoe, Vincent W V; Shaw, Pamela A; Tiemeier, Henning M; Hofman, Albert; Pierik, Frank H; Longnecker, Matthew P

2015-05-01

The widespread use of organophosphate (OP) pesticides has resulted in ubiquitous exposure in humans, primarily through their diet. Exposure to OP pesticides may have adverse health effects, including neurobehavioral deficits in children. The optimal design of new studies requires data on the reliability of urinary measures of exposure. In the present study, urinary concentrations of six dialkyl phosphate (DAP) metabolites, the main urinary metabolites of OP pesticides, were determined in 120 pregnant women participating in the Generation R Study in Rotterdam. Intra-class correlation coefficients (ICCs) across serial urine specimens taken at <18, 18-25, and >25 weeks of pregnancy were determined to assess reliability. Geometric mean total DAP metabolite concentrations were 229 (GSD 2.2), 240 (GSD 2.1), and 224 (GSD 2.2) nmol/g creatinine across the three periods of gestation. Metabolite concentrations from the serial urine specimens in general correlated moderately. The ICCs for the six DAP metabolites ranged from 0.14 to 0.38 (0.30 for total DAPs), indicating weak to moderate reliability. Although the DAP metabolite levels observed in this study are slightly higher and slightly more correlated than in previous studies, the low to moderate reliability indicates a high degree of within-person variability, which presents challenges for designing well-powered epidemiological studies.

Low concentrations of selenium and zinc in nails are associated with childhood asthma.

PubMed

Carneiro, Maria Fernanda Hornos; Rhoden, Claudia Ramos; Amantéa, Sérgio Luis; Barbosa, Fernando

2011-12-01

The purpose of this study was to investigate possible associations between Zn, Se, Cu, Mn, and Co concentrations in nails and asthma in a young population from a Southern Brazil city. Additionally, correlations between these chemical elements among asthmatic and non-asthmatic children were evaluated. Before nail collection (n = 165), children were asked to complete the International Study of Asthma and Allergies in Childhood questionnaire. The concentrations of trace elements were determined by inductively coupled plasma mass spectrometry. The chi-square test was used to evaluate the association between element concentrations in nails and the respiratory outcome. To evaluate correlations between the elements, we used the Spearman correlation test. For all tests, the significance level was set at 95% (P ≤ 0.05). Children included in the highest quartile of nail Se and Zn concentration presented a fivefold decrease in the prevalence ratio of asthma while children in the lowest Se range presented an almost 2.5-fold increase in the asthma prevalence ratio. There were weak to strong correlations between Cu vs. Zn, Cu vs. Co, Cu vs. Se, Zn vs. Se, Zn vs. Mn, and Mn vs. Co in both asthmatic and non-asthmatic children. Interestingly, non-asthmatics also presented correlations between Co vs. Se and Zn. Taken together, our results clearly demonstrated an association between concentrations of selenium and zinc and childhood asthma and the usefulness of nail as a noninvasive matrix to detect minerals imbalance in asthma patients.

MIXING RATIO INFLUENCES HALOACETIC ACID (HAA) MIXTURE TOXICITY

EPA Science Inventory

Mixtures of the same type (for example, disinfection byproduct mixtures) often contain the same chemicals, but at varying concentrations. The objective of the present study was to examine the influence of mixing ratio (the concentrations of chemicals relative to one another) on ...

Design of a Modular E-Core Flux Concentrating Axial Flux Machine: Preprint

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

Husain, Tausif; Sozer, Yilmaz; Husain, Iqbal

2015-08-24

In this paper a novel E-Core axial flux machine is proposed. The machine has a double-stator, single-rotor configuration with flux-concentrating ferrite magnets and pole windings across each leg of an E-Core stator. E-Core stators with the proposed flux-concentrating rotor arrangement result in better magnet utilization and higher torque density. The machine also has a modular structure facilitating simpler construction. This paper presents a single-phase and a three-phase version of the E-Core machine. Case studies for a 1.1-kW, 400-rpm machine for both the single-phase and three-phase axial flux machines are presented. The results are verified through 3D finite element analysis. facilitatingmore » simpler construction. This paper presents a single-phase and a three-phase version of the E-Core machine. Case studies for a 1.1-kW, 400-rpm machine for both the single-phase and three-phase axial flux machines are presented. The results are verified through 3D finite element analysis.« less

[Fatty acids in different edible fish species from Mexico].

PubMed

Castro González, María Isabel; Rodríguez, Ana Gabriela Maafs; Galindo Gómez, Carlos

2013-12-01

Different biotic and abiotic factors determine the fatty acid (FA) composition of fish tissues and organs. This information is useful for humans due to the fact that fish consumption is associated with health benefits. The aim of the present study was to identify the variation in the concentration of fatty acids, according to different factors, among ten edible marine fish species in Mexico, collected from June to December 2009 in the largest fish market in Mexico City: Euthynnus alletteratus, Sciaenops ocellatus, Bairdiella chrysoura, Sphyraena guachancho, Symphurus elongatus, Istiophorus platypterus, Ophichthus rex, Eugerres plumieri, Eucinostomus entomelas and Oreochromrnis mossambicus. Lipid content was gravimetrically quantified, the fatty acids were determined using a gas chromatograph and the results were statistically analyzed. Total lipid content ranged from 0.93 to 1.95 g/100 g in E. entomelas and O. urolepis hornorum, respectively. E. alletteratus, B. chrysoura, S. elongatus, I. platypterus, O. rex and E. plumieri presented the following order in FA concentration: Polyunsaturated FA (PUFA)>Saturated FA (SFA)>Monounsaturated FA (MUFA). S. ocellatus, S. guachancho and E. entomelas presented SFA>PUFA>MUFA; and only O. mossambicus presented SFA>MUFA>PUFA. O. mossambicus had the highest concentration (mg/100 g) of SFA (559.40) and MUFA (442.60), while B. chrysoura presented the highest content (mg/100 g) of PUFA (663.03), n-3 PUFA (514.03), EPA+DHA (506.10) and n-6 PUFA (145.80). Biotic and abiotic factors of the analyzed fish significantly influenced their FA concentration. Subtropical species presented 42.1% more EPA+DHA than tropical specie. Values presented here will vary according to the changes in the ecosystem and characteristics of each fish species, however the information generated in the present study is useful for improving fish consumption recommendations.

Functional Pattern of Increasing Concentrations of Brain-Derived Neurotrophic Factor in Spiral Ganglion: Implications for Research on Cochlear Implants.

PubMed

Ramku, Emina; Ramku, Refik; Spanca, Dugagjin; Zhjeqi, Valbona

2017-04-15

As previously various studies have suggested application of brain-derived neurotrophic factor (BDNF) may be considered as a promising future therapy for hearing deficits, in particular for the improvement of cochlear neurone loss during cochlear implantation. The present study's aim was to establish the upper threshold of the concentration of BDNF in Naval Medical Research Institute (NMRI) mice spiral ganglion outgrowth. Spiral ganglion explants were prepared from post-natal day 4 (p4) (NMRI) mice of both sexes under the approval and guidelines of the regional council of Hearing Research Institute Tubingen. Spiral ganglion explants were cultured at postnatal days 4 in the presence of different concentrations of BDNF as described under methods. We chose an age of postnatal day (P4) and concentrations of BDNF 0; 6; 12.5; 25 and 50 ƞg/ml. Averaged neurite outgrowth is measured in 4 different cultures that were treated with different concentrations. Results show that with increasing concentrations of BDNF, the neurite density increases. The present finding show evidence that BDNF has a clear incremental effect on the number of neurites of spiral ganglia in the prehearing organ, but less on the neurite length. The upper threshold of exogenous BNDF concentration on spiral ganglion explant is 25 ƞg/ml. This means that concentration beyond this level has no further incremental impact. Therefore our suggestion for hydrogel concentration in NMRA mice in future research should be 25 ƞg/ml.

Optimization of HNO3 leaching of copper from old AMD Athlon processors using response surface methodology.

PubMed

Javed, Umair; Farooq, Robina; Shehzad, Farrukh; Khan, Zakir

2018-04-01

The present study investigates the optimization of HNO 3 leaching of Cu from old AMD Athlon processors under the effect of nitric acid concentration (%), temperature (°C) and ultrasonic power (W). The optimization study is carried out using response surface methodology with central composite rotatable design (CCRD). The ANOVA study concludes that the second degree polynomial model is fitted well to the fifteen experimental runs based on p-value (0.003), R 2 (0.97) and Adj-R 2 (0.914). The study shows that the temperature is the most significant process variable to the leaching concentration of Cu followed by nitric acid concentration. However, ultrasound power shows no significant impact on the leaching concentration. The optimum conditions were found to be 20% nitric acid concentration, 48.89 °C temperature and 5.52 W ultrasound power for attaining maximum concentration of 97.916 mg/l for Cu leaching in solution. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of essential oil exposure on salivary estrogen concentration in perimenopausal women.

PubMed

Shinohara, Kazuyuki; Doi, Hirokazu; Kumagai, Chizu; Sawano, Erika; Tarumi, Wataru

2017-01-01

The menopausal transition is the time from the onset of menstrual changes until one year after the final menstrual period. During this phase, perimenopausal women experience a variety of health-related symptoms, which seemingly derive from declining level of estrogen secretion. It has long been recognized that some essential oils have the efficacy of alleviating menopausal symptoms. On the basis of this, it is possible that these essential oils have the potency to facilitate estrogen secretion in women. The present study investigated this possibility by examining if the olfactory exposure to the essential oil increase salivary estrogen concentration. We tested the effect of ten essential oils; clary sage, frankincense, geranium, lavender, jasmine absolute, neroli, rose otto, ylang ylang, orange and roman chamomile, which are thought to relieve perimenopasal symptoms. The results have shown increase of salivary estrogen concentration induced by exposure to geranium and rose otto compared to control odor. Together with the previous studies, the present study may give support to the notion that olfactory exposure to some essential oils can influence salivary concentration of estrogen.

Microbial Removal of the Pharmaceutical Compounds Ibuprofen and Diclofenac from Wastewater

PubMed Central

Inderfurth, Nadia; Schraa, Gosse; Kujawa-Roeleveld, Katarzyna; Rijnaarts, Huub

2013-01-01

Studies on the occurrence of pharmaceuticals show that the widely used pharmaceuticals ibuprofen and diclofenac are present in relevant concentrations in the environment. A pilot plant treating hospital wastewater with relevant concentrations of these pharmaceuticals was evaluated for its performance to reduce the concentration of the pharmaceuticals. Ibuprofen was completely removed, whereas diclofenac yielded a residual concentration, showing the necessity of posttreatment to remove diclofenac, for example, activated carbon. Successively, detailed laboratory experiments with activated sludge from the same wastewater treatment plant showed bioremediation potential in the treatment plant. The biological degradation pathway was studied and showed a mineralisation of ibuprofen and degradation of diclofenac. The present microbes were further studied in laboratory experiments, and DGGE analyses showed the enrichment and isolation of highly purified cultures that degraded either ibuprofen or diclofenac. This research illuminates the importance of the involved bacteria for the effectiveness of the removal of pharmaceuticals in a wastewater treatment plant. A complete removal of pharmaceuticals from wastewater will stimulate water reuse, addressing the worldwide increasing demand for clean and safe fresh water. PMID:24350260

Serum concentrations of metalloproteinase 2, metalloproteinase 9 and granzyme B in contact eczema patients

PubMed Central

Żbikowska-Gotz, Magdalena; Czajkowski, Rafał; Bartuzi, Zbigniew

2013-01-01

Introduction Contact eczema is a common skin condition with complex etiology, variable clinical presentation and lengthy therapy duration. The mechanism of contact eczema is complex, since it is affected by multiple inflammatory mediators. Aim To assess concentrations of metalloproteinase 2 (MMP-2), metalloproteinase 9 (MMP-9) and granzyme B (GzmB) in patients with contact eczema. Material and methods Seventy patients with contact eczema and 30 healthy persons as controls were included in the study. In all subjects, MMP-2, MMP-9 and GzmB were determined using ELISA immunoassay. In study group patients, concentrations were assayed in periods of disease exacerbation and remission. Obtained results were analyzed statistically. Results Mean MMP-2 and GzmB concentrations were found to be significantly higher in the study group than in the control group. Mean MMP-2, MMP-9 and GzmB levels were also statistically significantly higher during skin lesion relapse compared to contact eczema remission periods. Conclusions The presented paper demonstrates that MMP-2, MMP-9 and GzmB are good markers of contact eczema exacerbations. PMID:24278051

Per- and polyfluoroalkyl substances (PFASs) - New endocrine disruptors in polar bears (Ursus maritimus)?

PubMed

Pedersen, Kathrine Eggers; Letcher, Robert J; Sonne, Christian; Dietz, Rune; Styrishave, Bjarne

2016-11-01

Per- and polyfluoroalkyl substances (PFASs) are emerging in the Arctic and accumulate in brain tissues of East Greenland (EG) polar bears. In vitro studies have shown that PFASs might possess endocrine disrupting abilities and therefore the present study was conducted to investigate potential PFAS induced alterations in brain steroid concentrations. The concentrations of eleven steroid hormones were determined in eight brain regions from ten EG polar bears. Pregnenolone (PRE), the dominant progestagen, was found in mean concentrations of 5-47ng/g (ww) depending on brain region. PRE showed significantly (p<0.01) higher concentrations in female compared to male bears. Dehydroepiandrosterone (DHEA) found in mean concentrations 0.67-4.58ng/g (ww) was the androgen found in highest concentrations. Among the estrogens estrone (E1) showed mean concentrations of 0.90-2.21ng/g (ww) and was the most abundant. Remaining steroid hormones were generally present in concentrations below 2ng/g (ww). Steroid levels in brain tissue could not be explained by steroid levels in plasma. There was however a trend towards increasing estrogen levels in plasma resulting in increasing levels of androgens in brain tissue. Correlative analyses showed positive associations between PFASs and 17α-hydroxypregnenolone (OH-PRE) (e.g. perflouroalkyl sulfonates (∑PFSA): p<0.01, r=0.39; perfluoroalkyl carboxylates (∑PFCA): p<0.01, r=0.61) and PFCA and testosterone (TS) (∑PFCA: p=0.03, r=0.30) across brain regions. Further when investigating correlative associations in specific brain regions significant positive correlations were found between ∑PFCA and several steroid hormones in the occipital lobe. Correlative positive associations between PFCAs and steroids were especially observed for PRE, progesterone (PRO), OH-PRE, DHEA, androstenedione (AN) and testosterone (TS) (all p≤0.01, r≥0.7). The results from the present study generally indicate that an increase in PFASs concentration seems to concur with an increase in steroid hormones of EG polar bears. It is, however, not possible to determine whether alterations in brain steroid concentrations arise from interference with de novo steroid synthesis or via disruption of peripheral steroidogenic tissues mainly in gonads and feedback mechanisms. Steroids are important for brain plasticity and gender specific behavior as well as postnatal development and sexually dimorph brain function. The present work indicates an urgent need for a better mechanistic understanding of how PFASs may affect the endocrine system of polar bears and potentially other mammal species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Uncertainty of water type-specific hazardous copper concentrations derived with biotic ligand models.

PubMed

Vijver, Martina G; De Koning, Arjan; Peijnenburg, Willie J G M

2008-11-01

One of the aims of the Water Framework Directive is to derive Europe-wide environmental quality standards that are scientifically based and protective of surface waters. Accounting for water type-specific bioavailability corrections presents challenges and opportunities for metals research. In this study, we present generally applicable approaches for tiered risk assessment of chemicals for prospective use. The objective of the present study was to derive water type-specific dissolved copper criteria for Dutch surface waters. The intent was to show the utility of accounting for bioavailability by using biotic ligand models (BLMs) and two different ways of extrapolating these BLMs in order to obtain reliable bioavailability-corrected species sensitivity distributions. Water type-specific criteria estimations were generated for six different water quality conditions. Average hazard concentrations as calculated using the BLMs and the two alternate normalization scenarios varied significantly among the different water types, from 5.6 to 73.6 microg/L. Water types defined as large rivers, sandy springs, and acid ponds were most sensitive for Cu. Streams and brooks had the highest hazard concentrations. The two different options examined for toxicity data normalization did impact the calculated hazard concentrations for each water type.

Asbestos concentrations two years after abatement in seventeen schools. Final summary report

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

Kominsky, J.R.; Freyberg, R.W.; Brownlee, J.A.

Airborne asbestos concentrations were measured at 17 schools that underwent an asbestos abatement 2 years before in 1988. These 17 schools, which involved 20 abatement sites, were part of a study conducted by the U.S. Environmental Protection Agency (EPA) and the New Jersey Department of Health (NJDOH) in 1988. The 1988 study showed that asbestos concentrations measured independently by the NJDOH and EPA during the clearance phase of the abatement were elevated in the abatement and perimeter areas compared with outdoor concentrations. The present study was conducted to determine the current levels of airborne asbestos under simulated occupancy conditions andmore » to determine whether the elevated levels found during the clearance phase were still present 2 years after abatement. In 1990, four sites showed significantly higher mean asbestos concentrations inside the building (i.e., the previously abated area and/or perimeter area) compared with those outdoors (p<0.05). In 1990, the mean asbestos concentration measured in the perimeter area at one site and in the previously abated area at two sites were significantly higher than those in 1988 (p<0.05). Variations in asbestos levels between 1988 and 1990 may be due to sampling techniques (passive and aggressive versus modified aggressive), residual air-entrainable asbestos from the 1988 abatement, or air-entrainable asbestos from operations and maintenance activities since 1988.« less

Formation and transport of deethylatrazine and deisopropylatrazine in surface water

USGS Publications Warehouse

Thurman, E.M.; Meyer, M.T.; Mills, M.S.; Zimmerman, L.R.; Perry, C.A.; Goolsby, D.A.

1994-01-01

Field disappearance studies and a regional study of nine rivers in the Midwest Corn Belt show that deethylatrazine (DEA; 2-amino-4-chloro-6-isopropylamino-s-triazine) and deisopropylatrazine (DIA; 2-amino-4-chloro-6-ethylaminos-triazine) occur frequently in surface water that has received runoff from two parent triazine herbicides, atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) and cyanazine (2-chloro-4-ethylamino-6-methylpropionitrileamino-s-triazine). The concentration of DEA and DIA in surface water varies with the hydrologic conditions of the basin and the timing of runoff, with maximum concentrations reaching 5 ??g/L (DEA + DIA). Early rainfall followed by a dry summer will result in an early peak concentration of metabolites in surface water. A wet summer will delay the maximum concentrations of metabolites and increase their runoff into surface water, occasionally resulting in a slight separation of the parent atrazine maximum concentrations from the metabolite maximum concentrations, giving a "second flush?? of triazine metabolites to surface water. Replicated field dissipation studies of atrazine and cyanazine indicate that DIA/DEA ratios will vary from 0.4 ?? 0.1 when atrazine is the major triazine present to 0.6 ?? 0.1 when significant amounts of cyanazine are present. A comparison of transport time of DEA and DIA from field plots to their appearance in surface water indicates that storage and dilution are occurring in the alluvial aquifers of the basin.

VERSATILE AEROSOL CONCENTRATION ENRICHMENT SYSTEM (VACES) FOR SIMULTANEOUS IN-VIVO AND IN-VITRO EVALUATION OF TOXIC EFFECTS OF ULTRAFINE, FINE, AND COARSE AMBIENT PARTICLES. PART II. FIELD EVALUATION. (R826232)

EPA Science Inventory

Abstract

This study presents results from a field evaluation of a mobile versatile aerosol concentration enrichment system (VACES), designed to enhance the ambient concentrations of ultrafine (less than 0.18 VERSATILE AEROSOL CONCENTRATION ENRICHMENT SYSTEM (VACES) FOR SIMULTANEOUS IN VIVO AND IN VITRO EVALUATION OF TOXIC EFFECTS OF ULTRAFINE, FINE AND COARSE AMBIENT PARTICLES. PART II: FIELD EVALUATION. (R827352C001)

EPA Science Inventory

This study presents results from a field evaluation of a mobile versatile aerosol concentration enrichment system (VACES), designed to enhance the ambient concentrations of ultrafine (less than 0.18 Oral sampling methods are associated with differences in immune marker concentrations.

PubMed

Fakhry, Carole; Qeadan, Fares; Gilman, Robert H; Yori, Pablo; Kosek, Margaret; Patterson, Nicole; Eisele, David W; Gourin, Christine G; Chitguppi, Chandala; Marks, Morgan; Gravitt, Patti

2018-06-01

To determine whether the concentration and distribution of immune markers in paired oral samples were similar. Clinical research. Cross-sectional study. Paired saliva and oral secretions (OS) samples were collected. The concentration of immune markers was estimated using Luminex multiplex assay (Thermo Fisher Scientific, Waltham, MA). For each sample, the concentration of respective immune markers was normalized to total protein present and log-transformed. Median concentrations of immune markers were compared between both types of samples. Intermarker correlation in each sampling method and across sampling methods was evaluated. There were 90 study participants. Concentrations of immune markers in saliva samples were significantly different from concentrations in OS samples. Oral secretions samples showed higher concentrations of immunoregulatory markers, whereas the saliva samples contained proinflammatory markers in higher concentration. The immune marker profile in saliva samples is distinct from the immune marker profile in paired OS samples. 2b. Laryngoscope, 128:E214-E221, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Metal tissue levels in Steller sea lion (Eumetopias jubatus) pups.

PubMed

Holmes, Amie L; Wise, Sandra S; Goertz, Caroline E C; Dunn, J Lawrence; Gulland, Frances M D; Gelatt, Tom; Beckmen, Kimberlee B; Burek, Kathy; Atkinson, Shannon; Bozza, Mary; Taylor, Robert; Zheng, Tongzhang; Zhang, Yawei; Aboueissa, Abouel-Makarim; Wise, John Pierce

2008-08-01

The endangered Western population of the Steller sea lion declined for three decades for uncertain reasons. We present baseline data of metal concentrations in pups as a first step towards investigating the potential threat of developmental exposures to contaminants. Seven metals were investigated: arsenic, cadmium, silver, aluminum, mercury, lead and vanadium. Vanadium was detected in only a single blubber sample. Mercury appears to be the most toxicologically significant metal with concentrations in the liver well above the current action level for mercury in fish. The concentrations of aluminum, arsenic, silver, cadmium and lead were present in one-fourth to two-thirds of all samples and were at either comparable or below concentrations previously reported. Neither gender nor region had a significant effect on metal burdens. Future work should consider metal concentrations in juveniles and adults and toxicological studies need to be performed to begin to assess the toxicity of these metals.

Spatial and temporal distribution of mercury and methylmercury in bivalves from the French coastline.

PubMed

Briant, N; Chouvelon, T; Martinez, L; Brach-Papa, C; Chiffoleau, J F; Savoye, N; Sonke, J; Knoery, J

2017-01-30

Marine mercury (Hg) concentrations have been monitored in the French coastline for the last half a century using bivalves. The analyses presented in this study concerned 192 samples of bivalves (mussels: Mytilus edulis and Mytilus galloprovincialis and oysters: Crassostrea gigas and Isognomon alatus) from 77 sampling stations along the French coast and in the French Antilles sea. The goals of this study were to assess MeHg levels in various common bivalves from French coastline, and to identify possible geographic, taxonomic or temporal variations of concentrations. We show that the evolution of methylmercury (MeHg) concentrations covary with total mercury (HgT) concentrations. Moreover, in most of the study sites, HgT concentrations have not decreased since 1987, despite regulations to decrease or ban mercury used for anthropic activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fluoroquinolone Treatment and Susceptibility of Isolates From Bacterial Keratitis

PubMed Central

Ray, Kathryn J.; Prajna, Lalitha; Srinivasan, Muthiah; Geetha, Manoharan; Karpagam, Rajarathinam; Glidden, David; Oldenburg, Catherine E.; Sun, Catherine Q.; McLeod, Stephen D.; Acharya, Nisha R.; Lietman, Thomas M.

2013-01-01

Objective To analyze the relationship between fluoroquinolone use at presentation and minimum inhibitory concentration in bacterial keratitis. Methods The Steroids for Corneal Ulcers Trial was a randomized, double-masked, placebo-controlled trial assessing the effect of adjunctive topical corticosteroid treatment on outcomes in bacterial keratitis. After presentation, all patients were treated with moxifloxacin hydrochloride, 0.5%. We compare antibiotic use at presentation with minimum inhibitory concentration against moxifloxacin for all isolates. Separate analyses accounted for organism species and fluoroquinolone generation. Results Topical fluoroquinolone use at presentation was reported in 92 of 480 cases (19.2%). Causative organisms in the 480 cases included Streptococcus pneumoniae (247 cases [51.5%]), Pseudomonas aeruginosa (109 cases [22.7%]), and Nocardia species (55 cases [11.5%]). Isolates from patients who reported fluoroquinolone use at presentation had a 2.01-fold–higher minimum inhibitory concentration (95% CI, 1.39-fold to 2.91-fold; P <.001). Fourth-generation fluoroquinolones were associated with a 3.48-fold–higher minimum inhibitory concentration than those isolates that were not exposed to pretreatment at enrollment (95% CI, 1.99-fold to 6.06-fold; P <.001). Conclusion This study provides evidence that prior use of fluoroquinolones is associated with antibiotic resistance. PMID:23307105

Fluoroquinolone treatment and susceptibility of isolates from bacterial keratitis.

PubMed

Ray, Kathryn J; Prajna, Lalitha; Srinivasan, Muthiah; Geetha, Manoharan; Karpagam, Rajarathinam; Glidden, David; Oldenburg, Catherine E; Sun, Catherine Q; McLeod, Stephen D; Acharya, Nisha R; Lietman, Thomas M

2013-03-01

To analyze the relationship between fluoroquinolone use at presentation and minimum inhibitory concentration in bacterial keratitis. The Steroids for Corneal Ulcers Trial was a randomized, double-masked, placebo-controlled trial assessing the effect of adjunctive topical corticosteroid treatment on outcomes in bacterial keratitis. After presentation, all patients were treated with moxifloxacin hydrochloride, 0.5%. We compare antibiotic use at presentation with minimum inhibitory concentration against moxifloxacin for all isolates. Separate analyses accounted for organism species and fluoroquinolone generation. Topical fluoroquinolone use at presentation was reported in 92 of 480 cases (19.2%). Causative organisms in the 480 cases included Streptococcus pneumoniae (247 cases [51.5%]), Pseudomonas aeruginosa (109 cases [22.7%]), and Nocardia species (55 cases [11.5%]). Isolates from patients who reported fluoroquinolone use at presentation had a 2.01-fold-higher minimum inhibitory concentration (95% CI, 1.39-fold to 2.91-fold; P < .001). Fourth-generation fluoroquinolones were associated with a 3.48-fold-higher minimum inhibitory concentration than those isolates that were not exposed to pretreatment at enrollment (95% CI, 1.99-fold to 6.06-fold; P < .001). This study provides evidence that prior use of fluoroquinolones is associated with antibiotic resistance. clinicaltrials.gov Identifier: NCT00324168.

Effects of concentrate crude protein content on nutrient digestibility, energy utilization, and methane emissions in lactating dairy cows fed fresh-cut perennial grass.

PubMed

Hynes, D N; Stergiadis, S; Gordon, A; Yan, T

2016-11-01

Although many studies have investigated mitigation strategies for methane (CH 4 ) output from dairy cows fed a wide variety of diets, research on the effects of concentrate crude protein (CP) content on CH 4 emissions from dairy cows offered fresh grass is limited. The present study was designed to evaluate the effects of cow genotype and concentrate CP level on nutrient digestibility, energy utilization, and CH 4 emissions in dairy cows offered fresh-grass diets. Twelve multiparous lactating dairy cows (6 Holstein and 6 Holstein × Swedish Red) were blocked into 3 groups for each breed and assigned to a low-, medium-, or high-CP concentrate diet [14.1, 16.1, and 18.1% CP on a dry matter (DM) basis, respectively], in a 3-period changeover study (25d per period). Total diets contained (DM basis) 32.8% concentrates and 67.2% perennial ryegrass, which was harvested daily. All measurements were undertaken during the final 6d of each period: digestibility measurements for 6d and calorimetric measurements in respiration chambers for 3d. Feed intake and milk production data were reported in a previous paper. We observed no significant interaction between concentrate CP level and cow genotype on any parameter. Concentrate CP level had no significant effect on any energy utilization parameter, except for urinary energy output, which was positively related to concentrate CP level. Similarly, concentrate CP content had no effect on CH 4 emission (g/d), CH 4 per kg feed intake, or nutrient digestibility. Cross breeding of Holstein cows significantly reduced gross energy, digestible energy, and metabolizable energy intake, heat production, and milk energy output. However, cow genotype had no significant effect on energy utilization efficiency or CH 4 parameters. Furthermore, the present study yielded a value for gross energy lost as CH 4 (5.6%) on fresh grass-based diets that was lower than the widely accepted value of 6.5%. The present findings indicate that reducing concentrate CP content from 18.1 to 14.1% may not be a successful way of alleviating CH 4 emissions from lactating dairy cows offered good-quality fresh grass, but grazing cows could be offered a low-CP concentrate without compromising energy utilization efficiency. Further research is needed to investigate whether larger differences in dietary CP content may yield positive results. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Concentration dependent survival and neural differentiation of murine embryonic stem cells cultured on polyethylene glycol dimethacrylate hydrogels possessing a continuous concentration gradient of n-cadherin derived peptide His-Ala-Val-Asp-Lle.

PubMed

Lim, Hyun Ju; Mosley, Matthew C; Kurosu, Yuki; Smith Callahan, Laura A

2017-07-01

N-cadherin cell-cell signaling plays a key role in the structure and function of the nervous system. However, few studies have incorporated bioactive signaling from n-cadherin into tissue engineering matrices. The present study uses a continuous gradient approach in polyethylene glycol dimethacrylate hydrogels to identify concentration dependent effects of n-cadherin peptide, His-Ala-Val-Asp-Lle (HAVDI), on murine embryonic stem cell survival and neural differentiation. The n-cadherin peptide was found to affect the expression of pluripotency marker, alkaline phosphatase, in murine embryonic stem cells cultured on n-cadherin peptide containing hydrogels in a concentration dependent manner. Increasing n-cadherin peptide concentrations in the hydrogels elicited a biphasic response in neurite extension length and mRNA expression of neural differentiation marker, neuron-specific class III β-tubulin, in murine embryonic stem cells cultured on the hydrogels. High concentrations of n-cadherin peptide in the hydrogels were found to increase the expression of apoptotic marker, caspase 3/7, in murine embryonic stem cells compared to that of murine embryonic stem cell cultures on hydrogels containing lower concentrations of n-cadherin peptide. Increasing the n-cadherin peptide concentration in the hydrogels facilitated greater survival of murine embryonic stem cells exposed to increasing oxidative stress caused by hydrogen peroxide exposure. The combinatorial approach presented in this work demonstrates concentration dependent effects of n-cadherin signaling on mouse embryonic stem cell behavior, underscoring the need for the greater use of systematic approaches in tissue engineering matrix design in order to understand and optimize bioactive signaling in the matrix for tissue formation. Single cell encapsulation is common in tissue engineering matrices. This eliminates cellular access to cell-cell signaling. N-cadherin, a cell-cell signaling molecule, plays a vital role in the development of neural tissues, but has not been well studied as a bioactive signaling element in neural tissue engineering matrices. The present study uses a systematic continuous gradient approach to identify concentration dependent effects of n-cadherin derived peptide, HAVDI, on the survival and neural differentiation of murine embryonic stem cells. This work underscores the need for greater use to combinatorial strategies to understand the effect complex bioactive signaling, such as n-cadherin, and the need to optimize the concentration of such bioactive signaling within tissue engineering matrices for maximal cellular response. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Correlations of water quality parameters with mutagenicity of chlorinated drinking water samples.

PubMed

Schenck, Kathleen M; Sivaganesan, Mano; Rice, Glenn E

2009-01-01

Adverse health effects that may result from chronic exposure to mixtures of disinfection by-products (DBPs) present in drinking waters may be linked to both the types and concentrations of DBPs present. Depending on the characteristics of the source water and treatment processes used, both types and concentrations of DBPs found in drinking waters vary substantially. The composition of a drinking-water mixture also may change during distribution. This study evaluated the relationships between mutagenicity, using the Ames assay, and water quality parameters. The study included information on treatment, mutagenicity data, and water quality data for source waters, finished waters, and distribution samples collected from five full-scale drinking water treatment plants, which used chlorine exclusively for disinfection. Four of the plants used surface water sources and the fifth plant used groundwater. Correlations between mutagenicity and water quality parameters are presented. The highest correlation was observed between mutagenicity and the total organic halide concentrations in the treated samples.

Microgreens of brassicaceae: mineral composition and content of 30 varieties

USDA-ARS?s Scientific Manuscript database

The aim of the present study was to analyze the mineral content and concentration of 30 species of microgreens, representative 10 genera of the Brassicaceae family. Brassicaceae microgreens were assayed for concentrations of macroelements, including calcium (Ca), magnesium (Mg), phosphorous (P), sod...

Contaminants in Liquid Organic Fertilizers Used for Agriculture in Japan.

PubMed

Hai, Dao M; Qiu, Xuchun; Xu, Hai; Honda, Masato; Yabe, Mitsuyasu; Kadokami, Kiwao; Shimasaki, Yohei; Oshima, Yuji

2017-07-01

To provide an overview of anthropogenic contaminants in liquid organic fertilizers (LOFs), products from four biogas plants in Kyushu, Japan, were analyzed for a wide range of contaminants, including copper, cadmium, tributyltin (TBT), dibutyltin (DBT), perfluorooctane sulfonate, 952 semi-volatile organic compounds, and 89 antibiotics. The highest concentrations of copper (31.1 mg/L) and cadmium (0.08 mg/L) were found in LOFs from the Hita biogas plant. Only ofloxacin and sulfapyridine were detected in total 89 antibiotics screened. TBT, DBT, and perfluorooctane sulfonate were present at low concentrations in the LOFs from all four locations. Among the 952 semi-volatile organic compounds, 78 compounds were detected in at least one sample and were present at concentrations between 1.2 and 139.6 mg/L. On the basis of comparisons with previous studies and quality standards for the use of organic fertilizers, the concentrations of contaminants in the studied LOFs indicate that they might be safe for agricultural purposes.

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.

Effect of nitrogen species supply and mycorrhizal colonization on organosulfur and phenolic compounds in onions.

PubMed

Perner, Henrike; Rohn, Sascha; Driemel, Gregor; Batt, Natalie; Schwarz, Dietmar; Kroh, Lothar W; George, Eckhard

2008-05-28

The aim of the present study was to test whether variations in the root environment affect the content of health-related organosulfur compounds, total phenolic compounds, and flavonol glycoside concentrations in onions. For this purpose, greenhouse-grown onions ( Allium cepa L.) were either inoculated with a commercial arbuscular mycorrhizal inoculum or a sterile inoculum and were provided with two NH(4)(+):NO(3)(-) ratios as a nitrogen source. Onion growth, arbuscular mycorrhizal colonization rate, sugars, and nutrient element concentrations were also quantified. The plant antioxidant activity and quercetin monoglucoside and organosulfur compound concentrations increased with dominant nitrate supply. Furthermore, mycorrhizal colonization increased the antioxidant activity and also concentrations of the major quercetin glucosides. The present study provides clear evidence that antioxidant activity, quercetin glycosides, and organosulfur compounds can be increased in sufficiently supplied onion plants by dominant nitrate supply or application of arbuscular mycorrhizal fungi. This was probably due to increased precursor production and induced defense mechanisms.

Influence of local meteorology and NO2 conditions on ground-level ozone concentrations in the eastern part of Texas, USA.

PubMed

Gorai, A K; Tuluri, F; Tchounwou, P B; Ambinakudige, S

2015-02-01

The influence of local climatic factors on ground-level ozone concentrations is an area of increasing interest to air quality management in regards to future climate change. This study presents an analysis on the role of temperature, wind speed, wind direction, and NO 2 level on ground-level ozone concentrations over the region of Eastern Texas, USA. Ozone concentrations at the ground level depend on the formation and dispersion processes. Formation process mainly depends on the precursor sources, whereas, the dispersion of ozone depends on meteorological factors. Study results showed that the spatial mean of ground-level ozone concentrations was highly dependent on the spatial mean of NO 2 concentrations. However, spatial distributions of NO 2 and ozone concentrations were not uniformed throughout the study period due to uneven wind speeds and wind directions. Wind speed and wind direction also played a significant role in the dispersion of ozone. Temperature profile in the area rarely had any effects on the ozone concentrations due to low spatial variations.

Influence of local meteorology and NO2 conditions on ground-level ozone concentrations in the eastern part of Texas, USA

PubMed Central

Gorai, A. K.; Tuluri, F.; Tchounwou, P. B.; Ambinakudige, S.

2014-01-01

The influence of local climatic factors on ground-level ozone concentrations is an area of increasing interest to air quality management in regards to future climate change. This study presents an analysis on the role of temperature, wind speed, wind direction, and NO2 level on ground-level ozone concentrations over the region of Eastern Texas, USA. Ozone concentrations at the ground level depend on the formation and dispersion processes. Formation process mainly depends on the precursor sources, whereas, the dispersion of ozone depends on meteorological factors. Study results showed that the spatial mean of ground-level ozone concentrations was highly dependent on the spatial mean of NO2 concentrations. However, spatial distributions of NO2 and ozone concentrations were not uniformed throughout the study period due to uneven wind speeds and wind directions. Wind speed and wind direction also played a significant role in the dispersion of ozone. Temperature profile in the area rarely had any effects on the ozone concentrations due to low spatial variations. PMID:25755687

Fundamentals and techniques of nonimaging optics, volume 2

NASA Astrophysics Data System (ADS)

Winston, R.; Ogallagher, J. J.

1983-06-01

The formalism describing the operation is being defined, nonimaging concentrators and are being designed, and experiments and analytical studies are being conducted to evaluate the performance of new designs. In addition, components and materials particularly suited for use with these techniques were studied, and applications with an emphasis on solar energy concentration were explored. The motivation for the basic principles of nonimaging optics as they developed before 1978 are surveyed. The present status of the subdiscipline of nonimaging optics is summarized and an overview of the potential for future developments which is just beginning to emerge is presented.

Seasonal changes in amino acids, protein and total nitrogen in needles of fertilized Scots pine trees.

PubMed

Näsholm, T; Ericsson, A

1990-09-01

Seasonal changes in amino acids, protein and total nitrogen in needles of 30-year-old, fertilized Scots pine (Pinus sylvestris L.) trees growing in Northern Sweden were investigated over two years in field experiments. The studied plots had been fertilized annually for 17 years with (i) a high level of N, (ii) a medium level of N, or (iii) a medium level of N, P and K. Trees growing on unfertilized plots served as controls. In control trees, glutamine, glutamic acid, gamma-aminobutyric acid, aspartic acid and proline represented 50-70% of the total free amino acids determined. Arginine was present only in low concentrations in control trees throughout the year, but it was usually the most abundant amino acid in fertilized trees. Glutamine concentrations were high during the spring and summer in both years of study, whereas proline concentrations were high in the spring but otherwise low throughout the year. In the first year of study, glutamic acid concentrations were high during the spring and summer, whereas gamma-aminobutyric acid was present in high concentrations during the winter months. This pattern was less pronounced in the second year of investigation. The concentrations of most amino acids, except glutamic acid, increased in response to fertilization. Nitrogen fertilization increased the foliar concentration of arginine from < 1 micromol g(dw) (-1) in control trees to a maximum of 110 micromol g(dw) (-1). Trees fertilized with nitrogen, phosphorus and potassium had significantly lower arginine concentrations than trees fertilized with the same amount of nitrogen only. Protein concentrations were similar in all fertilized trees but higher than those in control trees. For all treatments, protein concentrations were high in winter and at a minimum in early spring. In summer, the protein concentration remained almost constant except for a temporary decrease which coincided with the expansion of new shoots. Apart from arginine, the amino acid composition of proteins was similar in all treatments.

Effect of reactor loading on atomic oxygen concentration as measured by NO chemiluminescence

NASA Technical Reports Server (NTRS)

Lerner, N. R.

1989-01-01

It has previously been observed that the etch rate of polyethylene samples in the afterglow of an RF discharge in oxygen increases with reactor loading. This enhancement of the etch rate is attributed to reactive gas phase products of the polymer etching. In the present work, emission spectroscopy is employed to examine the species present in the gas phase during etching of polyethylene. In particular, the concentration of atomic oxygen downstream from the polyethylene samples is studied as a function of the reactor loading. It is found that the concentration of atomic oxygen increases as the reactor loading is increased. The increase of etch rate with increased reactor loading is attributed to the increase of atomic oxygen concentration in the vicinity of the sample.

Determination of polychlorinated biphenyls, selected persistent organochlorine pesticides, and polybrominated flame retardants in fillets of fishes from the 2006 Missouri Department of Conservation Monitoring Programs

USGS Publications Warehouse

Gale, Robert W.; May, Thomas W.; Orazio, Carl E.; McKee, Michael J.

2008-01-01

This report presents the results of a study to determine polychlorinated biphenyl, organochlorine pesticide, and polybrominated diphenyl ether flame retardant concentrations in selected fishes from lakes and streams across Missouri. Fillets were collected from each fish sample, and after homogenization, compositing, and preparation, analyte concentrations were determined with dual column capillary gas chromatography-electron-capture detection. Total concentrations of polychlorinated biphenyls in samples ranged from background levels of about 20 to 1,200 nanograms per gram. Chlordanes and DDT-related chemicals constituted the primary classes of pesticides present at elevated concentrations in most samples, and ranged from 5 to 340 nanograms per gram. Total concentrations of polybrominated diphenyl ethers in samples ranged from background levels of about 5 to about 410 nanograms per gram. Concentrations of total technical chlordane ranged from less than 5 to 260 nanograms per gram. Concentrations of polychlorinated biphenyls, chlordanes, DDT-related compounds, and polybrominated diphenyl ethers were all greatest in samples of blue catfish from Cape Girardeau and Weldon Spring.

Evaluation of the use of Leptodactylus ocellatus (Anura: Leptodactylidae) frog tissues as bioindicator of metal contamination in Contas River, Northeastern Brazil.

PubMed

Correia, Lívia O; Siqueira Júnior, Sérgio; Carneiro, Paulo L S; Bezerra, Marcos A

2014-12-01

This paper presents a study on the viability of the use of tissues of the Leptodactylus ocellatus species (Anura Leptodactylidae) as a bioindicator of metal pollution. The study is based on the determination and correlation of the concentrations of manganese, chromium, zinc, nickel, copper and iron in sediments and tissues (skin, muscles and viscera) of the frog Leptodactylus ocellatus collected in the middle region of the Contas River in Bahia, Brazil. The highest levels of the metals studied were found in the viscera of this animal. In this tissue, a higher correlation of the concentration of these metals with those found in sediments was also observed. The concentrations of elements found in the skin and muscles of these amphibians have revealed no correlation with the sediment where they were collected. According to the results obtained, the viscera of the L. ocellatus species presents itself as a good bioindicator of contamination by the metals studied.

Evaluation of the use of Leptodactylus ocellatus (Anura: Leptodactylidae) frog tissues as bioindicator of metal contamination in Contas River, Northeastern Brazil.

PubMed

Correia, Lívia O; Siqueira Júnior, Sérgio; Carneiro, Paulo L S; Bezerra, Marcos A

2014-10-24

This paper presents a study on the viability of the use of tissues of the Leptodactylus ocellatus species (Anura Leptodactylidae) as a bioindicator of metal pollution. The study is based on the determination and correlation of the concentrations of manganese, chromium, zinc, nickel, copper and iron in sediments and tissues (skin, muscles and viscera) of the frog Leptodactylus ocellatus collected in the middle region of the Contas River in Bahia, Brazil. The highest levels of the metals studied were found in the viscera of this animal. In this tissue, a higher correlation of the concentration of these metals with those found in sediments was also observed. The concentrations of elements found in the skin and muscles of these amphibians have revealed no correlation with the sediment where they were collected. According to the results obtained, the viscera of the L. ocellatus species presents itself as a good bioindicator of contamination by the metals studied.

Presence and distribution of wastewater-derived pharmaceuticals in soil irrigated with reclaimed water

USGS Publications Warehouse

Kinney, C.A.; Furlong, E.T.; Werner, S.L.; Cahill, J.D.

2006-01-01

Three sites in the Front Range of Colorado, USA, were monitored from May through September 2003 to assess the presence and distribution of pharmaceuticals in soil irrigated with reclaimed water derived from urban wastewater. Soil cores were collected monthly, and 19 pharmaceuticals, all of which were detected during the present study, were measured in 5-cm increments of the 30-cm cores. Samples of reclaimed water were analyzed three times during the study to assess the input of pharmaceuticals. Samples collected before the onset of irrigation in 2003 contained numerous pharmaceuticals, likely resulting from the previous year's irrigation. Several of the selected pharmaceuticals increased in total soil concentration at one or more of the sites. The four most commonly detected pharmaceuticals were erythromycin, carbamazepine, fluoxetine, and diphenhydramine. Typical concentrations of the individual pharmaceuticals observed were low (0.02-15 ??g/kg dry soil). The existence of subsurface maximum concentrations and detectable concentrations at the lowest sampled soil depth might indicate interactions of soil components with pharmaceuticals during leaching through the vadose zone. Nevertheless, the present study demonstrates that reclaimed-water irrigation results in soil pharmaceutical concentrations that vary through the irrigation season and that some compounds persist for months after irrigation. ?? 2006 SETAC.

Perfluoroalkyl substances in human bone: concentrations in bones and effects on bone cell differentiation.

PubMed

Koskela, A; Koponen, J; Lehenkari, P; Viluksela, M; Korkalainen, M; Tuukkanen, J

2017-07-28

Perfluoroalkyl substances (PFAS), including two most commonly studied compounds perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are widely distributed environmental pollutants, used extensively earlier. Due to their toxicological effects the use of PFAS is now regulated. Based on earlier studies on PFOA's distribution in bone and bone marrow in mice, we investigated PFAS levels and their possible link to bone microarchitecture of human femoral bone samples (n = 18). Soft tissue and bone biopsies were also taken from a 49-year old female cadaver for PFAS analyses. We also studied how PFOA exposure affects differentiation of human osteoblasts and osteoclasts. PFAS were detectable from all dry bone and bone marrow samples, PFOS and PFOA being the most prominent. In cadaver biopsies, lungs and liver contained the highest concentrations of PFAS, whereas PFAS were absent in bone marrow. Perfluorononanoic acid (PFNA) was present in the bones, PFOA and PFOS were absent. In vitro results showed no disturbance in osteogenic differentiation after PFOA exposure, but in osteoclasts, lower concentrations led to increased resorption, which eventually dropped to zero after increase in PFOA concentration. In conclusion, PFAS are present in bone and have the potential to affect human bone cells partly at environmentally relevant concentrations.

Development of a 3-wire probe for the simultaneous measurement of turbulent velocity, concentration and temperature fields

NASA Astrophysics Data System (ADS)

Hewes, Alaïs; Mydlarski, Laurent

2015-11-01

The present work focuses on the design and optimization of a probe used to simultaneously measure the velocity, concentration and temperature fields in a turbulent jet. The underlying principles of this sensor are based in thermal-anemometry techniques, and the design of this 3-wire probe builds off the previous work of Sirivat and Warhaft, J. Fluid Mech., 1982. In the first part of this study, the effect of different overheat ratios in the first two wires (called the ``interference'' or ``Way-Libby'' probe - used to infer velocity and concentration) are investigated. Of particular interest is their effect on the quality of the resulting calibration, as well as the measured velocity and concentration data. Four different overheat ratio pairs for the two wires comprising the interference probe are studied. In the second part of this work, a third wire, capable of detecting temperature fluctuations, is added to the 3-wire probe. The optimal configuration of this probe, including wire type and overheat ratio for the third wire, is studied and the simultaneously-measured velocity, concentration, and temperature data (e.g. spectra, PDFs) for different probe configurations are presented. Supported by the Natural Sciences and Engineering Research Council of Canada (Grant 217184).

Fruit and vegetables consumption is associated with higher vitamin intake and blood vitamin status among European adolescents.

PubMed

Mielgo-Ayuso, J; Valtueña, J; Huybrechts, I; Breidenassel, C; Cuenca-García, M; De Henauw, S; Stehle, P; Kafatos, A; Kersting, M; Widhalm, K; Manios, Y; Azzini, E; Molnar, D; Moreno, L A; González-Gross, M

2017-04-01

Current research in adults indicates that fruit and vegetable (FAV) consumption increases serum levels of vitamins C, E and folate of β-carotene and reduces homocysteine concentrations. The aim of the present study was to examine the association of FAV consumption on vitamin intakes and their impact on blood vitamin concentrations in European adolescents. This multi-center cross-sectional study included 702 (53.7% females) adolescents, aged 12.50-17.49 years, from 10 European cities. Two independent self-administered 24 h dietary recalls were used to estimate the adolescent's diet. The total energy, vitamins and FAV consumption were calculated. Adolescents were categorized into three groups: (i) very low FAV intake (<200 g/day); (ii) low FAV consumption (200-399 g/day) and (iii) adequate FAV consumption (⩾400 g/day). Adolescent's fasted blood samples were taken for their analysis on vitamin concentrations. The main results showed that those adolescents meeting the FAV recommendation, classified as FAV adequate consumers, presented higher intake of energy and some vitamins as B6, total folic acid, C, E and β-carotene compared with FAV very low consumers (P<0.05). Regarding their blood status, male adolescents who had a very low FAV consumption presented lower plasma folate, RBC folate blood concentrations compared with adequate FAV consumers (P<0.05). Female adequate FAV consumers had higher concentrations of pyridoxal phosphate (PLP), plasma folate, RBC folate, vitamin C, β-carotene and α-tocopherol compared with very low and low consumers (P<0.05). Having a FAV dairy intake above 400 g/day is associated with higher vitamin intake and blood vitamin concentrations, especially for antioxidant and B-vitamins concentrations.

Accuracy of trace element determinations in alternate fuels

NASA Technical Reports Server (NTRS)

Greenbauer-Seng, L. A.

1980-01-01

NASA-Lewis Research Center's work on accurate measurement of trace level of metals in various fuels is presented. The differences between laboratories and between analytical techniques especially for concentrations below 10 ppm, are discussed, detailing the Atomic Absorption Spectrometry (AAS) and DC Arc Emission Spectrometry (dc arc) techniques used by NASA-Lewis. Also presented is the design of an Interlaboratory Study which is considering the following factors: laboratory, analytical technique, fuel type, concentration and ashing additive.

Low-calorie cranberry juice supplementation reduces plasma oxidized LDL and cell adhesion molecule concentrations in men.

PubMed

Ruel, Guillaume; Pomerleau, Sonia; Couture, Patrick; Lemieux, Simone; Lamarche, Benoît; Couillard, Charles

2008-02-01

Elevated circulating concentrations of oxidized LDL (OxLDL) and cell adhesion molecules are considered to be relevant markers of oxidative stress and endothelial activation which are implicated in the development of CVD. On the other hand, it has been suggested that dietary flavonoid consumption may be cardioprotective through possible favourable impacts on LDL particle oxidation and endothelial activation. The present study was undertaken to determine the effect of the daily consumption of low-calorie cranberry juice cocktail on plasma OxLDL, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin concentrations in men. Thirty men (mean age 51 (sd 10) years) were recruited and asked to consume increasing daily doses of cranberry juice cocktail (125, 250 and 500 ml/d) over three successive periods of 4 weeks. Plasma OxLDL and adhesion molecule concentrations were measured by ELISA before and after each phase. We noted a significant decrease in plasma OxLDL concentrations following the intervention (P < 0.0001). We also found that plasma ICAM-1 (P < 0.0001) and VCAM-1 (P < 0.05) concentrations decreased significantly during the course of the study. In summary, the present results show that daily cranberry juice cocktail consumption is associated with decreases in plasma OxLDL, ICAM-1 and VCAM-1 concentrations in men.

Optics of two-stage photovoltaic concentrators with dielectric second stages.

PubMed

Ning, X; O'Gallagher, J; Winston, R

1987-04-01

Two-stage photovoltaic concentrators with Fresnel lenses as primaries and dielectric totally internally reflecting nonimaging concentrators as secondaries are discussed. The general design principles of such two-stage systems are given. Their optical properties are studied and analyzed in detail using computer ray trace procedures. It is found that the two-stage concentrator offers not only a higher concentration or increased acceptance angle, but also a more uniform flux distribution on the photovoltaic cell than the point focusing Fresnel lens alone. Experimental measurements with a two-stage prototype module are presented and compared to the analytical predictions.

Optics of two-stage photovoltaic concentrators with dielectric second stages

NASA Astrophysics Data System (ADS)

Ning, Xiaohui; O'Gallagher, Joseph; Winston, Roland

1987-04-01

Two-stage photovoltaic concentrators with Fresnel lenses as primaries and dielectric totally internally reflecting nonimaging concentrators as secondaries are discussed. The general design principles of such two-stage systems are given. Their optical properties are studied and analyzed in detail using computer ray trace procedures. It is found that the two-stage concentrator offers not only a higher concentration or increased acceptance angle, but also a more uniform flux distribution on the photovoltaic cell than the point focusing Fresnel lens alone. Experimental measurements with a two-stage prototype module are presented and compared to the analytical predictions.

Left ventricular diastolic function in workers occupationally exposed to mercury vapour without clinical presentation of cardiac involvement

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

Poręba, Rafał, E-mail: sogood@poczta.onet.pl; Skoczyńska, Anna; Gać, Paweł

2012-09-15

The aim of the study was to evaluate left ventricular diastolic function in workers occupationally exposed to mercury vapour without clinical presentation of cardiac involvement. The studies included 115 workers (92 men and 23 women) occupationally exposed to mercury vapour without clinical presentation of cardiac involvement (mean age: 47.83 ± 8.29). Blood samples were taken to determine blood lipid profile, urine was collected to estimate mercury concentration (Hg-U) and echocardiographic examination was performed to evaluate diastolic function of the left ventricle. In the entire group of workers occupationally exposed to mercury vapour without clinical presentation of cardiac involvement, Spearman correlationsmore » analysis demonstrated the following significant linear relationships: between body mass index (BMI) and ratio of maximal early diastolic mitral flow velocity/early diastolic mitral annular velocity (E/E') (r = 0.32, p < 0.05), between serum HDL concentration and E/E' (r = − 0.22, p < 0.05), between Hg-U and E/E' (r = 0.35, p < 0.05), between Hg-U and isovolumetric relaxation time (IVRT') (r = 0.41, p < 0.05), between Hg-U and ratio of maximal early diastolic mitral flow velocity/maximal late diastolic mitral flow velocity (E/A) (r = − 0.31, p < 0.05) and between serum HDL concentration and E/A (r = 0.43, p < 0,05). In logistic regression analysis it as shown that independent factors of left ventricular diastolic dysfunction risk in the study group included a higher urine mercury concentration, a higher value of BMI and a lower serum HDL concentration (OR{sub Hg}-{sub U} = 1.071, OR{sub BMI} = 1.200, OR{sub HDL} = 0.896, p < 0.05). Summing up, occupational exposure to mercury vapour may be linked to impaired left ventricular diastolic function in workers without clinical presentation of cardiac involvement. -- Highlights: ► Study aimed at evaluation of LVDD in workers occupationally exposed to Hg. ► There was significant linear relationships between Hg-U and E/E'. ► Independent risk factor of LVDD in study group included higher Hg-U. ► Independent risk factor of LVDD in study group included higher BMI and lower HDL. ► Occupational exposure to Hg may be linked to LVDD.« less

Comprehensive analysis of polyamine transport and biosynthesis in the dominant human gut bacteria: Potential presence of novel polyamine metabolism and transport genes.

PubMed

Sugiyama, Yuta; Nara, Misaki; Sakanaka, Mikiyasu; Gotoh, Aina; Kitakata, Aya; Okuda, Shujiro; Kurihara, Shin

2017-12-01

Recent studies have reported that polyamines in the colonic lumen might affect animal health and these polyamines are thought to be produced by gut bacteria. In the present study, we measured the concentrations of three polyamines (putrescine, spermidine, and spermine) in cells and culture supernatants of 32 dominant human gut bacterial species in their growing and stationary phases. Combining polyamine concentration analysis in culture supernatant and cells with available genomic information showed that novel polyamine biosynthetic proteins and transporters were present in dominant human gut bacteria. Based on these findings, we suggested strategies for optimizing polyamine concentrations in the human colonic lumen via regulation of genes responsible for polyamine biosynthesis and transport in the dominant human gut bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

Validating bioindicators of PAH effects in fish: Evaluating responsiveness to creosote exposure in aquatic mesocosms

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

Munro, K.A.; Solomon, K.R.; Gensemer, R.W.

1994-12-31

While studies involving controlled exposures to PAHs have typically studied the effects of exposure to individual compounds, PAHs are usually present in the environment in complex mixtures. Some of these (eg. creosote) have been widely used and present potential risks to aquatic ecosystems. The objective of the current research is to evaluate whether population effects visible in fish at high creosote concentrations would be reflected in biomarker responses at lower concentrations. Goldfish (Carassius auratus) were exposed to five levels of creosote contamination in microcosms containing a simple community structure (including macroinvertebrates and macrophytes). Preliminary results have shown that changes inmore » P450 induction, bile fluorescence, and levels of reproductive hormones are visible at lower concentrations than population effects such as increased mortality, reduced secondary sexual characteristics, and reduced fecundity.« less

Molecular and macro-scale analysis of enzyme-crosslinked silk hydrogels for rational biomaterial design.

PubMed

McGill, Meghan; Coburn, Jeannine M; Partlow, Benjamin P; Mu, Xuan; Kaplan, David L

2017-11-01

Silk fibroin-based hydrogels have exciting applications in tissue engineering and therapeutic molecule delivery; however, their utility is dependent on their diffusive properties. The present study describes a molecular and macro-scale investigation of enzymatically-crosslinked silk fibroin hydrogels, and demonstrates that these systems have tunable crosslink density and diffusivity. We developed a liquid chromatography tandem mass spectroscopy (LC-MS/MS) method to assess the quantity and order of covalent tyrosine crosslinks in the hydrogels. This analysis revealed between 28 and 56% conversion of tyrosine to dityrosine, which was dependent on the silk concentration and reactant concentration. The crosslink density was then correlated with storage modulus, revealing that both crosslinking and protein concentration influenced the mechanical properties of the hydrogels. The diffusive properties of the bulk material were studied by fluorescence recovery after photobleaching (FRAP), which revealed a non-linear relationship between silk concentration and diffusivity. As a result of this work, a model for synthesizing hydrogels with known crosslink densities and diffusive properties has been established, enabling the rational design of silk hydrogels for biomedical applications. Hydrogels from naturally-derived silk polymers offer versitile opportunities in the biomedical field, however, their design has largely been an empirical process. We present a fundamental study of the crosslink density, storage modulus, and diffusion behavior of enzymatically-crosslinked silk hydrogels to better inform scaffold design. These studies revealed unexpected non-linear trends in the crosslink density and diffusivity of silk hydrogels with respect to protein concentration and crosslink reagent concentration. This work demonstrates the tunable diffusivity and crosslinking in silk fibroin hydrogels, and enables the rational design of biomaterials. Further, the characterization methods presented have applications for other materials with dityrosine crosslinks, which are found in nature as post-translational modificaitons, as well as in engineered matrices such as tyramine-substituted hyaluronic acid and recombinant resilin. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Trends and threshold exceedances analysis of airborne pollen concentrations in Metropolitan Santiago Chile

PubMed Central

Toro A., Richard; Córdova J., Alicia; Canales, Mauricio; Morales S., Raul G. E.; Mardones P., Pedro; Leiva G., Manuel A.

2015-01-01

Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over the period 2009–2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresponding time trends are evaluated. The concentrations of the pollens are compared with the established threshold levels for the protection of human health. The results show that the total amount of pollen grains originating from trees, grasses, weeds and indeterminate sources throughout the period of the study was 258,496 grains m-3, with an annual average of 51,699 ± 3,906 grains m-3 year-1. The primary source of pollen is Platanus orientalis, which produces 61.8% of the analyzed pollen. Grass pollen is the third primary component of the analyzed pollen, with a contribution of 5.82%. Among the weeds, the presence of Urticacea (3.74%) is remarkable. The pollination pattern of the trees is monophasic, and the grasses have a biphasic pattern. The trends indicate that the total pollen and tree pollen do not present a time trend that is statistically significant throughout the period of the study, whereas the grass pollen and weed pollen concentrations in the environment present a statistically significant decreasing trend. The cause of this decrease is unclear. The pollen load has doubled over the past decade. When the observed concentrations of the pollens were compared with the corresponding threshold levels, the results indicated that over the period of the study, the pollen concentrations were at moderate, high and very high levels for an average of 293 days per year. Systematic counts of the pollen grains are an essential method for diagnosing and treating patients with pollinosis and for developing forestation and urban planning strategies. PMID:25946339

Muscle- and Mode-Specific Responses of the Forearm Flexors to Fatiguing, Concentric Muscle Actions

PubMed Central

Hill, Ethan; Housh, Terry; Smith, Cory; Schmidt, Richard; Johnson, Glen

2016-01-01

Background: Electromyographic (EMG) and mechanomyographic (MMG) studies of fatigue have generally utilized maximal isometric or dynamic muscle actions, but sport- and work-related activities involve predominately submaximal movements. Therefore, the purpose of the present investigation was to examine the torque, EMG, and MMG responses as a result of submaximal, concentric, isokinetic, forearm flexion muscle actions. Methods: Twelve men performed concentric peak torque (PT) and isometric PT trials before (pretest) and after (posttest) performing 50 submaximal (65% of concentric PT), concentric, isokinetic (60°·s−1), forearm flexion muscle actions. Surface EMG and MMG signals were simultaneously recorded from the biceps brachii and brachioradialis muscles. Results: The results of the present study indicated similar decreases during both the concentric PT and isometric PT measurements for torque, EMG mean power frequency (MPF), and MMG MPF following the fatiguing workbout, but no changes in EMG amplitude (AMP) or MMG AMP. Conclusions: These findings suggest that decreases in torque as a result of fatiguing, dynamic muscle actions may have been due to the effects of metabolic byproducts on excitation–contraction coupling as indicated by the decreases in EMG MPF and MMG MPF, but lack of changes in EMG AMP and MMG AMP from both the biceps brachii and brachioradialis muscles.

Concentrations of the Allelochemical (+/-)-catechin IN Centaurea maculosa soils.

PubMed

Perry, Laura G; Thelen, Giles C; Ridenour, Wendy M; Callaway, Ragan M; Paschke, Mark W; Vivanco, Jorge M

2007-12-01

The phytotoxin (+/-)-catechin has been proposed to mediate invasion and autoinhibition by the Eurasian plant Centaurea maculosa (spotted knapweed). The importance of (+/-)-catechin to C. maculosa ecology depends in part on whether sufficient catechin concentrations occur at appropriate times and locations within C. maculosa soil to influence neighboring plants. Previous research on catechin in C. maculosa soils has yielded conflicting results, with some studies finding high soil catechin concentrations and other, more recent studies finding little or no catechin in field soils. Here, we report the most extensive study of soil catechin concentrations to date. We examined soil catechin concentrations in 402 samples from 11 C. maculosa sites in North America sampled in consecutive months over 1 yr, excluding winter months. One site was sampled on seven dates, another was sampled twice, and the remaining nine sites were each sampled once on a range of sampling dates. Methods used were similar to those with which we previously measured high soil catechin concentrations. We detected catechin only in the site that was sampled on seven dates and only on one sampling date in that site (May 16 2006), but in all samples collected on that date. The mean soil catechin concentration on that date was 0.65 +/- 0.45 (SD) mg g(-1), comparable to previously reported high concentrations. There are a number of possible explanations for the infrequency with which we detected soil catechin in this work compared to previous studies. Differences in results could reflect spatial and temporal variation in catechin exudation or degradation, as we examined different sites in a different year from most previous studies. Also, large quantities of catechin were detected in blanks for two sampling periods in the present study, leading us to discard those data. This contamination suggests that previous reports of high catechin concentrations that did not include blanks should be viewed with caution. Our results suggest that pure catechin is only rarely present in C. maculosa bulk soils. Thus, although catechin may play a role in C. maculosa invasion, the infrequency of soil catechin that we determined in this study suggests that we cannot be as certain of its role as previous reports of high soil catechin concentrations suggested.

Bioaccumulation and toxicity assessment of irrigation water contaminated with boron (B) using duckweed (Lemna gibba L.) in a batch reactor system.

PubMed

Türker, Onur Can; Yakar, Anıl; Gür, Nurcan

2017-02-15

The present study assesses ability of Lemna gibba L. using a batch reactor approach to bioaccumulation boron (B) from irrigation waters which were collected from a stream in largest borax reserve all over the world. The important note that bioaccumulation of B from irrigation water was first analyzed for first time in a risk assessment study using a Lemna species exposed to various B concentrations. Boron toxicity was evaluated through plant growth and biomass production during phytoremediation process. The result from the present experiment indicated that L. gibba was capable of removing 19-63% B from irrigation water depending upon contaminated level or initial concentration. We also found that B was removed from aqueous solution following pseudo second order kinetic model and Langmuir isotherm model better fitted equilibrium obtained for B phytoremediation. Maximum B accumulation in L. gibba was determined as 2088mgkg -1 at average inflow B concentration 17.39mgL -1 at the end of the experiment. Conversely, maximum bioconcentration factor obtained at lowest inflow B concentrations were 232 for L. gibba. The present study suggested that L. gibba was very useful B accumulator, and thus L. gibba-based techniques could be a reasonable phytoremediation option to remove B directly from water sources contaminated with B. Copyright © 2016 Elsevier B.V. All rights reserved.

Heavy metals and metalloid content in vegetables and soil collected from the gardens of Zagreb, Croatia.

PubMed

Puntarić, Dinko; Vidosavljević, Domagoj; Gvozdić, Vlatka; Puntarić, Eda; Puntarić, Ida; Mayer, Dijana; Bosnir, Jasna; Lasić, Dario; Jergović, Matijana; Klarić, Ivana; Vidosavljević, Marina; Krivdić, Ivancica

2013-09-01

Aim of this study was to determine concentration of Pb, Cd, As and Hg in green leafy vegetables and soil in the urban area of Zagreb, Croatia and to determine if there is a connection between the contamination of soil and vegetables. Green leafy vegetables and soil samples were taken from the gardens located in the outskirts of the city. Concentrations of Pb, Cd, As and Hg were determined by atomic absorption spectrometry; showing that average concentrations of metals and metalloids in vegetables and in soil, regardless of the location of sampling were below the maximum allowed concentration (MAC). The analysis determined that metal concentrations in only nine vegetable samples (9%) were above maximum allowed values prescribed by national and European legislation (three with higher concentrations of Pb, one with a higher concentration of Cd and five with higher concentrations of Hg). Concentrations of contaminants present in the analysed samples, in general, are lower than the ones published in similar studies. The final distribution and concentration of contaminants in vegetables of Zagreb, besides industry and traffic, is affected by the dominant wind direction.

Temporal and spatial behavior of pharmaceuticals in ...

EPA Pesticide Factsheets

The behavior of active pharmaceutical ingredients (APIs) in urban estuaries is not well understood. In this study, 15 high volume usage APIs were measured over a one year period throughout Narragansett Bay, RI, USA to determine factors controlling their concentration and distribution. Dissolved APIs ranged in concentration from not detected to 310 ng/L, with numerous APIs present at all sites and sampling periods. Eight APIs were present in suspended particulate material, ranging in concentration from <1 ng/g to 44 ng/g. Partitioning coefficients (Kds) were determined for APIs present in both the dissolved and particulate phases, with their range and variability remaining relatively constant during the study. Organic carbon normalization reduced the observed variability of several APIs to a small extent; however, other factors appear to play a role in controlling partitioning behavior. The continuous discharge of wastewater treatment plant effluents into upper Narragansett Bay resulted in sustained levels of APIs, resulting in a zone of “pseudo-persistence.” For most of the APIs, there was a strong relationship with salinity, indicating conservative behavior within the estuary. Short flushing times in Narragansett Bay coupled with APIs present primarily in the dissolved phase suggests that most APIs will be diluted and transported out of the estuary, with only small amounts of several compounds removed to and sequestered in sediments. This study ide

Effect of feed flushing during summer season on growth, reproductive performance and blood metabolites in Malpura ewes under semiarid tropical environment.

PubMed

Naqvi, Syed Mohammad Khursheed; Sejian, Veerasamy; Karim, Shaikh Abdul

2013-01-01

Feed scarcity during hot summer months is one of the major predisposing factors for low reproductive efficiency of livestock reared in hot semiarid environment. A study was conducted to assess the effect of concentrate supplementation during summer months on growth, reproductive performance, and blood metabolites in Malpura ewes. Twenty adult Malpura ewes were used in the present study. The ewes were divided into two groups viz, group 1 (n = 10; control) and group 2 (n = 10; concentrate supplementation). The study was conducted for a period of 35 days covering two estrus cycles. In the first cycle, only PGF(2α) was given to all ewes, while in second cycle, all ewes were synchronized for estrus using progesterone-impregnated intravaginal sponges and pregnant mare serum gonadotropin. The animals were allowed for grazing for 8-10 h per day. Apart from grazing, group 2 ewes were supplemented with concentrate mixture at 1.5 % of body weight. Concentrate supplementation had significant influence on body weight, ADG, estrus percentage, estrus duration, onset of estrus, ovulation response, plasma glucose, total protein, and urea. The present study reveals that ewes supplemented with concentrate mixture at 1.5 % of body weights during summer season significantly influenced the growth and reproductive performance of Malpura ewes. Further, the study signifies the importance of providing additional feed supplementation to ewes kept grazing under the conditions of a hot, semiarid environment to improve their reproductive efficiency.

Effect of soil moisture on seasonal variation in indoor radon concentration: modelling and measurements in 326 Finnish houses

PubMed Central

Arvela, H.; Holmgren, O.; Hänninen, P.

2016-01-01

The effect of soil moisture on seasonal variation in soil air and indoor radon is studied. A brief review of the theory of the effect of soil moisture on soil air radon has been presented. The theoretical estimates, together with soil moisture measurements over a period of 10 y, indicate that variation in soil moisture evidently is an important factor affecting the seasonal variation in soil air radon concentration. Partitioning of radon gas between the water and air fractions of soil pores is the main factor increasing soil air radon concentration. On two example test sites, the relative standard deviation of the calculated monthly average soil air radon concentration was 17 and 26 %. Increased soil moisture in autumn and spring, after the snowmelt, increases soil gas radon concentrations by 10–20 %. In February and March, the soil gas radon concentration is in its minimum. Soil temperature is also an important factor. High soil temperature in summer increased the calculated soil gas radon concentration by 14 %, compared with winter values. The monthly indoor radon measurements over period of 1 y in 326 Finnish houses are presented and compared with the modelling results. The model takes into account radon entry, climate and air exchange. The measured radon concentrations in autumn and spring were higher than expected and it can be explained by the seasonal variation in the soil moisture. The variation in soil moisture is a potential factor affecting markedly to the high year-to-year variation in the annual or seasonal average radon concentrations, observed in many radon studies. PMID:25899611

Diffusiophoresis of charged colloidal particles in the limit of very high salinity.

PubMed

Prieve, Dennis C; Malone, Stephanie M; Khair, Aditya S; Stout, Robert F; Kanj, Mazen Y

2018-06-13

Diffusiophoresis is the migration of a colloidal particle through a viscous fluid, caused by a gradient in concentration of some molecular solute; a long-range physical interaction between the particle and solute molecules is required. In the case of a charged particle and an ionic solute (e.g., table salt, NaCl), previous studies have predicted and experimentally verified the speed for very low salt concentrations at which the salt solution behaves ideally. The current study presents a study of diffusiophoresis at much higher salt concentrations (approaching the solubility limit). At such large salt concentrations, electrostatic interactions are almost completely screened, thus eliminating the long-range interaction required for diffusiophoresis; moreover, the high volume fraction occupied by ions makes the solution highly nonideal. Diffusiophoretic speeds were found to be measurable, albeit much smaller than for the same gradient at low salt concentrations.

Relation of water quality to land use in the drainage basins of four tributaries to the Toms River, New Jersey, 1994--1995

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

Hunchak-Kariouk, K.

1999-01-01

This report describes the results of a study to determine the relation between land use and the water quality of four tributaries to the Toms River--Long Swamp Creek, Wrangel Brook, Davenport Branch, and Jakes Branch. The constituent concentrations and yield values presented in this report are based on water-quality and streamflow data collected at seven sites during base flow and stormflow conditions during May 1994 to October 1995. Concentrations and yields (area-normalized instantaneous load values) during periods of base flow and stormflow in the growing and nongrowing seasons are presented for sites on Long Swamp Creek, Wrangel Brook, and Davenportmore » Branch. Only concentrations during base flow are presented for the site on Jakes Branch. Water-quality constituents for which concentrations and yield values are reported include total nitrogen, ammonia, nitrate, organic nitrogen, hydrolyzable phosphorus plus orthophosphorus, orthophosphorus, total suspended solids, and fecal-coliform bacteria. Concentrations of nitrite and Escherichia coliform bacteria also are listed. Distributions of constituent concentrations and yields during base flow and stormflow in the growing and nongrowing season are shown in boxplots. Specific conductance, pH, temperature, and dissolved oxygen in the four tributaries also are discussed, and their values are listed.« less

DEVELOPMENT AND LABORATORY CHARACTERIZATION OF A PROTOTYPE COARSE PARTICLE CONCENTRATOR FOR INHALATION TOXICOLOGICAL STUDIES. (R825270)

EPA Science Inventory

This paper presents the development and laboratory characterization of a prototype slit nozzle virtual impactor that can be used to concentrate coarse particles. A variety of physical design and flow parameters were evaluated including different acceleration and collection sli...

Evaluation of Time- and Concentration-dependent Toxic Effect Models for use in Aquatic Risk Assessments, Oral Presentation

EPA Science Inventory

Various models have been proposed for describing the time- and concentration-dependence of toxic effects to aquatic organisms, which would improve characterization of risks in natural systems. Selected models were evaluated using results from a study on the lethality of copper t...

SIMULATION STUDY FOR GASEOUS FLUXES FROM AN AREA SOURCE USING COMPUTED TOMOGRAPHY AND OPTICAL REMOTE SENSING

EPA Science Inventory

The paper presents a new approach to quantifying emissions from fugitive gaseous air pollution sources. Computed tomography (CT) and path-integrated optical remote sensing (PI-ORS) concentration data are combined in a new field beam geometry. Path-integrated concentrations are ...

Medical Service Clinical Laboratory Procedure--Hematology.

ERIC Educational Resources Information Center

Department of the Army, Washington, DC.

Presented are laboratory studies focusing on blood cells and the complete scheme of blood coagulation. Formed is the basis for the following types of laboratory operations: (1) distinguishing the morphology of normal and abnormal blood cells; (2) measuring the concentrations or number of blood cells; (3) measuring concentration and detecting…

Metabolomic profiling of amino acids and beta-cell function relative to insulin sensitivity in youth

USDA-ARS?s Scientific Manuscript database

In longitudinal studies of adults, elevated amino acid (AA) concentrations predicted future type 2 diabetes mellitus (T2DM). The aim of the present investigation was to examine whether increased plasma AA concentrations are associated with impaired beta-cell function relative to insulin sensitivity ...

Background Indoor Air Concentrations of Volatile Organic Compounds in North American Residences (1990 – 2005): A Compilation of Statistics for Assessing Vapor Intrusion

EPA Pesticide Factsheets

This technical report presents a summary of indoor air studies that measured background concentrations of VOCs in the indoor air of thousands of North American residences and an evaluation and compilation of their reported statistical information.

Reliability of concentrations of organophosphate pesticide metabolites in serial urine specimens from pregnancy in the Generation R study

PubMed Central

Spaan, Suzanne; Pronk, Anjoeka; Koch, Holger M.; Jusko, Todd A.; Jaddoe, Vincent W.V.; Shaw, Pamela A.; Tiemeier, Henning M.; Hofman, Albert; Pierik, Frank H.; Longnecker, Matthew P.

2014-01-01

The widespread use of organophosphate (OP) pesticides has resulted in ubiquitous exposure in humans, primarily through their diet. Exposure to OP pesticides may have adverse health effects, including neurobehavioral deficits in children. The optimal design of new studies requires data on the reliability of urinary measures of exposure. In the present study, urinary concentrations of six dialkyl phosphate (DAP) metabolites, the main urinary metabolites of OP pesticides, were determined in 120 pregnant women participating in the Generation R Study in Rotterdam. Intra-class correlation coefficients (ICCs) across serial urine specimens taken at <18, 18–25, and >25 weeks of pregnancy were determined to assess reliability. Geometric mean total DAP metabolite concentrations were 229 (GSD 2.2), 240 (GSD 2.1), and 224 (GSD 2.2) nmol/g creatinine across the three periods of gestation. Metabolite concentrations from the serial urine specimens in general correlated moderately. The ICCs for the six DAP metabolites ranged from 0.14 to 0.38 (0.30 for total DAPs), indicating weak to moderate reliability. Although the DAP metabolite levels observed in this study are slightly higher and slightly more correlated than in previous studies, the low to moderate reliability indicates a high degree of within-person variability, which presents challenges for designing well-powered epidemiologic studies. PMID:25515376

Economic Inequality in Presenting Vision in Shahroud, Iran: Two Decomposition Methods

PubMed Central

Mansouri, Asieh; Emamian, Mohammad Hassan; Zeraati, Hojjat; Hashemi, Hasan; Fotouhi, Akbar

2018-01-01

Background: Visual acuity, like many other health-related problems, does not have an equal distribution in terms of socio-economic factors. We conducted this study to estimate and decompose economic inequality in presenting visual acuity using two methods and to compare their results in a population aged 40-64 years in Shahroud, Iran. Methods: The data of 5188 participants in the first phase of the Shahroud Cohort Eye Study, performed in 2009, were used for this study. Our outcome variable was presenting vision acuity (PVA) that was measured using LogMAR (logarithm of the minimum angle of resolution). The living standard variable used for estimation of inequality was the economic status and was constructed by principal component analysis on home assets. Inequality indices were concentration index and the gap between low and high economic groups. We decomposed these indices by the concentration index and BlinderOaxaca decomposition approaches respectively and compared the results. Results: The concentration index of PVA was -0.245 (95% CI: -0.278, -0.212). The PVA gap between groups with a high and low economic status was 0.0705 and was in favor of the high economic group. Education, economic status, and age were the most important contributors of inequality in both concentration index and Blinder-Oaxaca decomposition. Percent contribution of these three factors in the concentration index and Blinder-Oaxaca decomposition was 41.1% vs. 43.4%, 25.4% vs. 19.1% and 15.2% vs. 16.2%, respectively. Other factors including gender, marital status, employment status and diabetes had minor contributions. Conclusion: This study showed that individuals with poorer visual acuity were more concentrated among people with a lower economic status. The main contributors of this inequality were similar in concentration index and Blinder-Oaxaca decomposition. So, it can be concluded that setting appropriate interventions to promote the literacy and income level in people with low economic status, formulating policies to address economic problems in the elderly, and paying more attention to their vision problems can help to alleviate economic inequality in visual acuity. PMID:29325403

Application of semipermeable membrane devices for long-term monitoring of polycyclic aromatic hydrocarbons at various stages of drinking water treatment.

PubMed

Pogorzelec, Marta; Piekarska, Katarzyna

2018-08-01

The primary goal of the presented study was the investigation of occurrence and concentration of sixteen selected polycyclic aromatic hydrocarbons in samples from various stages of water treatment and verification of the applicability of semi-permeable membrane devices in the monitoring of drinking water. Another objective was to verify if weather seasons affect the concentration and complexity of PAHs. For these purposes, semipermeable membrane devices were installed in a surface water treatment plant located in Lower Silesia (Poland). Samples were collected monthly over a period of one year. To determine the effect of water treatment on PAH concentrations, four sampling sites were selected: raw water input, a stream of water in the pipe just before ozonation, treated water output and water after passing through the distribution system. After each month of sampling, SPMDs were exchanged for fresh ones and prepared for instrumental analysis. Concentrations of polycyclic aromatic hydrocarbons were determined by high-performance liquid chromatography (HPLC). The presented study indicates that semipermeable membrane devices can be an effective tool for the analysis of drinking water, in which organic micropollutants occur at very low concentrations. Copyright © 2018 Elsevier B.V. All rights reserved.

Short term effects of increasing dietary salt concentrations on urine composition in healthy cats.

PubMed

Paßlack, N; Burmeier, H; Brenten, T; Neumann, K; Zentek, J

2014-09-01

High dietary salt (NaCl) concentrations are assumed to be beneficial in preventing the formation of calcium oxalate (CaOx) uroliths in cats, since increased water intake and urine volume have been observed subsequent to intake. In human beings, dietary NaCl restriction is recommended for the prevention of CaOx urolith formation, since high NaCl intake is associated with increased urinary Ca excretion. The aim of the present study was to clarify the role of dietary NaCl in the formation of CaOx uroliths in cats. Eight cats received four diets that differed in Na and Cl concentrations (0.38-1.43% Na and 0.56-2.52% Cl dry matter, DM). Each feeding period consisted of a 21 day adaptation period, followed by a 7 day sampling period for urine collection. Higher dietary NaCl concentrations were associated with increased urine volume and renal Na excretion. Urinary Ca concentration was constant, but renal Ca excretion increased from 0.62 to 1.05 mg/kg bodyweight (BW)/day with higher dietary NaCl concentrations (P ≤ 0.05). Urinary oxalate (Ox), citrate, P and K concentrations decreased when NaCl intake was high (P ≤ 0.05), and urinary pH was low in all groups (6.33-6.45; P > 0.05). Relative supersaturation of CaOx in the urine was unaffected by dietary NaCl concentrations. In conclusion, the present study demonstrated several beneficial effects of high dietary NaCl intake over a relatively short time period. In particular, urinary Ca concentration remained unchanged because of increased urine volume. Decreased urinary Ox concentrations might help to prevent the formation of CaOx uroliths, but this should be verified in future studies in diseased or predisposed cats. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multifaceted empathy of healthy volunteers after single doses of MDMA: A pooled sample of placebo-controlled studies

PubMed Central

Kuypers, Kim PC; Dolder, Patrick C; Ramaekers, Johannes G; Liechti, Matthias E

2017-01-01

Previous placebo-controlled experimental studies have shown that a single dose of MDMA can increase emotional empathy in the multifaceted empathy test (MET) without affecting cognitive empathy. Although sufficiently powered to detect main effects of MDMA, these studies were generally underpowered to also validly assess contributions of additional parameters, such as sex, drug use history, trait empathy and MDMA or oxytocin plasma concentrations. The present study examined the robustness of the MDMA effect on empathy and investigated the moderating role of these additional parameters. Participants (n = 118) from six placebo-controlled within-subject studies and two laboratories were included in the present pooled analysis. Empathy (MET), MDMA and oxytocin plasma concentrations were assessed after oral administration of MDMA (single dose, 75 or 125 mg). Trait empathy was assessed using the interpersonal reactivity index. We confirmed that MDMA increased emotional empathy at both doses without affecting cognitive empathy. This MDMA-related increase in empathy was most pronounced during presentation of positive emotions as compared with negative emotions. MDMA-induced empathy enhancement was positively related to MDMA blood concentrations measured before the test, but independent of sex, drug use history and trait empathy. Oxytocin concentrations increased after MDMA administration but were not associated with behavioral effects. The MDMA effects on emotional empathy were stable across laboratories and doses. Sex did not play a moderating role in this effect, and oxytocin levels, trait empathy and drug use history were also unrelated. Acute drug exposure was of significant relevance in the MDMA-induced emotional empathy elevation. PMID:28372480

Multifaceted empathy of healthy volunteers after single doses of MDMA: A pooled sample of placebo-controlled studies.

PubMed

Kuypers, Kim Pc; Dolder, Patrick C; Ramaekers, Johannes G; Liechti, Matthias E

2017-05-01

Previous placebo-controlled experimental studies have shown that a single dose of MDMA can increase emotional empathy in the multifaceted empathy test (MET) without affecting cognitive empathy. Although sufficiently powered to detect main effects of MDMA, these studies were generally underpowered to also validly assess contributions of additional parameters, such as sex, drug use history, trait empathy and MDMA or oxytocin plasma concentrations. The present study examined the robustness of the MDMA effect on empathy and investigated the moderating role of these additional parameters. Participants ( n = 118) from six placebo-controlled within-subject studies and two laboratories were included in the present pooled analysis. Empathy (MET), MDMA and oxytocin plasma concentrations were assessed after oral administration of MDMA (single dose, 75 or 125 mg). Trait empathy was assessed using the interpersonal reactivity index. We confirmed that MDMA increased emotional empathy at both doses without affecting cognitive empathy. This MDMA-related increase in empathy was most pronounced during presentation of positive emotions as compared with negative emotions. MDMA-induced empathy enhancement was positively related to MDMA blood concentrations measured before the test, but independent of sex, drug use history and trait empathy. Oxytocin concentrations increased after MDMA administration but were not associated with behavioral effects. The MDMA effects on emotional empathy were stable across laboratories and doses. Sex did not play a moderating role in this effect, and oxytocin levels, trait empathy and drug use history were also unrelated. Acute drug exposure was of significant relevance in the MDMA-induced emotional empathy elevation.

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.

Molecular Probes: A Tool for Studying Toxicity of VOCs to P.Putida F1

NASA Astrophysics Data System (ADS)

Singh, R.; Olson, M. S.

2007-12-01

Volatile Organic Compounds (VOCs) are of great concern in ground water remediation, and are generally present in the form of NAPLs in subsurface environments. Among the various treatment technologies, in situ bioremediation is one of the most effective and low-cost treatment options. Many soil bacteria are reported to degrade these organic contaminants via metabolism (using them as a source of carbon to derive energy) or co- metabolism up to certain concentrations. However, larger concentrations of these contaminants are toxic to bacteria. Thus, in order to achieve successful bioremediation, it is important to determine the optimal concentrations of various contaminants that is beneficial for the activity and survival of degrading bacteria. The purpose of this study is to develop a novel method for toxicity analyses of VOC contaminants to the soil bacteria that degrade them. The present study is based on a two-color fluorescence assay of bacterial viability which facilitates actual counting of live and dead bacteria. Pseudomonas putida F1 cells were labeled with a LIVE/DEAD® BacLightTM bacterial viability kit (Invitrogen), which consists of a mixture of two dyes, SYTO 9 and propidium iodide, each with a different ability to penetrate healthy bacterial cells. Live cells stain green whereas propidium iodide (red dye) only penetrates cells with compromised membranes that are considered dead or dying. Stained cells were exposed to different concentrations of trichloroethylene (TCE) and toluene in sealed vials. Change in the concentrations of green and red cells were monitored over the time using fluorescence microscopy. UTHSCSA ImageTool software was used to count the live and dead cells in the images. It was observed that live (green) cell concentrations decreased and dead/damaged (red) cell concentrations increased over time when cells were exposed to TCE. No significant changes were observed in control experiments. Death rate constants calculated based on live cell disappearance and dead/damaged cell appearance were found to be approximately equal for TCE. Results will be presented in terms of dose response and death rate curves. Death rate constants and minimum inhibitory concentrations for survival of P. Putida F1 exposed to TCE and toluene will be compared.

Serum uric acid concentrations are directly associated with the presence of benign multiple sclerosis.

PubMed

Simental-Mendía, Esteban; Simental-Mendía, Luis E; Guerrero-Romero, Fernando

2017-09-01

It has been reported that patients with multiple sclerosis (MS) exhibit lower serum uric acid levels; however, the association between uric acid concentrations and benign MS (BMS) has not been assessed. Hence, the objective of the present study was to determine whether the serum concentrations of uric acid are associated with the presence of BMS. Men and non-pregnant women over 16 years of age with diagnosis of MS were enrolled in a cross-sectional study. Expanded Disability Status Scale score < 3, progression of disease ≤10 years, diabetes, renal or hepatic diseases, gout, malignancy, alcohol intake, and treatment with thiazide diuretics and/or acetylsalicylic acid were exclusion criteria. According to subtype of disease, the eligible patients were allocated into groups with BMS and other varieties of MS. A logistic regression analysis was conducted in order to evaluate the association between serum concentrations of uric acid and BMS. A total of 106 patients were included, 39 in the group with BMS and 67 in the group with other varieties of MS. The logistic regression analysis adjusted by age, sex, and disease duration showed that increased concentrations of uric acid, indeed within the physiological levels, are significantly associated with the presence of BMS (OR = 2.60; 95% CI: 1.55-4.38, p < 0.001). The results of the present study suggest that elevated concentrations of uric acid, indeed within the physiological range, are likely linked to the presence of BMS.

Assessing atmospheric concentration of polychlorinated biphenyls by evergreen Rhododendron maximum next to a contaminated stream.

PubMed

Dang, Viet D; Walters, David M; Lee, Cindy M

2016-09-01

Conifers are often used as an air passive sampler, but few studies have focused on the implication of broadleaf evergreens to monitor atmospheric semivolatile organic compounds such as polychlorinated biphenyls (PCBs). In the present study, the authors used Rhododendron maximum (rhododendron) growing next to a contaminated stream to assess atmospheric PCB concentrations. The present study area was located in a rural setting and approximately 2 km downstream of a former capacitor plant. Leaves from the same mature shrubs were collected in late fall 2010 and winter and spring 2011. Polychlorinated biphenyls were detected in the collected leaves, suggesting that rhododendron can be used as air passive samplers in rural areas where active sampling is impractical. Estimated ΣPCB (47 congeners) concentrations in the atmosphere decreased from fall 2010 to spring 2011 with concentration means at 3990 pg m(-3) , 2850 pg m(-3) , and 931 pg m(-3) in fall 2010, winter 2011, and spring 2011, respectively. These results indicate that the atmospheric concentrations at this location continue to be high despite termination of active discharge from the former industrial source. Leaves had a consistent pattern of high concentrations of tetra-CBs and penta-CBs similar to the congener distribution in polyethylene passive samplers deployed in the water column, suggesting that volatilized PCBs from the stream were the primary source of contaminants in rhododendron leaves. Environ Toxicol Chem 2016;35:2192-2198. © 2016 SETAC. © 2016 SETAC.

Bos indicus cattle possess greater basal concentrations of HSP27, alpha B-crystallin, and HSP70 in skeletal muscle in vivo compared with cattle.

PubMed

Mullins, C R; Zerby, H N; Fitzpatrick, L A; Parker, A J

2016-01-01

The objectives of the present study were to evaluate the basal concentrations of heat shock proteins (HSP) between and cattle and to determine if HSP basal concentrations change as an animal matures. A total of 40 cattle were used in a 2 × 2 factorial design to evaluate the effects of genotype and age (heifers and mature cows) on basal concentrations of heat shock protein 27 (HSP27), α B-crystallin (Cryab), and heat shock protein 70 (HSP70). Each experimental group of 10 animals was sampled on a separate day over a period of 4 wk during July 2014. A muscle sample was collected from the longissimus thoracis (LT) and concentrations of HSP were quantified using ELISA. There were no significant differences in HSP concentration for the interaction between age and genotype or for age alone. cattle had greater ( < 0.05) basal concentrations of HSP27, Cryab, and HSP70 in the LT than cattle. The results of this study show that basal in vivo HSP concentrations differ between and cattle. However, further studies are needed to investigate the relationship between HSP concentrations and meat tenderness with respect to genotypes to see if HSP concentrations account for at least some variability in tenderness differences.

[Experimental study on the influence of natural and artificial ventilation on indoor radon concentration].

PubMed

Remetti, R; Gigante, G E

2010-01-01

The study presents the results of a campaign of measurements on the daily radon concentration using a Genitron Alpha Guard spectrometer. All the measurements have been intended to highlight the radon concentration variability during the 24 hours of the day and trying to find correlations with other ambient parameters such as temperature and pressure or local conditions such as the presence or not of a forced ventilation system. The main part of the measurements have been carried in the area of the Nuclear Measurement Laboratory of the Department of Basic and Applied Sciences for Engineering of "Sapienza" University of Rome. Results show a rapid rise of radon concentration in the night, when the artificial ventilation system was off and with door and windows closed. In the morning, after the opening of door and windows, the concentration falls down abruptly. With artificial ventilation system in function concentration never reaches significant values.

Investigating Uranium Concentrations in Groundwaters in the State of Idaho Using Kinetic Phosphorescence Analysis and Inductively Coupled Plasma Mass Spectrometry.

PubMed

Tkavadze, Levan; Dunker, Roy E; Brey, Richard R; Dudgeon, John

2016-11-01

The determination of uranium concentrations in natural water samples is of great interest due to the environmental consequences of this radionuclide. In this study, 380 groundwater samples from various locations within the state of Idaho were analyzed using two different techniques. The first method was Kinetic Phosphorescence Analysis (KPA), which gives the total uranium concentrations in water samples. The second analysis method was inductively coupled plasma mass spectrometry (ICP- MS). This method determines the total uranium concentration as well as the separate isotope concentrations of uranium. The U/U isotopic ratio was also measured for each sample to confirm that there was no depleted or enriched uranium present. The results were compared and mapped separately from each other. The study also found that in some areas of the state, natural uranium concentrations are relatively high.

Preparation and in vitro function of granulocyte concentrates for transfusion to neonates using the IBM 2991 blood processor.

PubMed

Goldfinger, D; Medici, M A; Hsi, R; McPherson, J; Connelly, M

1983-01-01

Clinical studies have suggested that granulocyte transfusions may be of value in the treatment of septic neonatal patients who present with severe granulocytopenia. We have developed a protocol for the preparation of granulocyte concentrates from freshly collected units of whole blood, using an automated blood cell processor. The red cells were washed with saline. Then, the buffy coats were collected from the washed red cells and studied for their suitability as granulocyte concentrates for neonatal transfusion. The mean number of granulocytes per concentrate was 1.6 X 10(9) in a mean volume of 25 ml. Studies of granulocyte function, including viability, random mobility, chemotaxis, phagocytosis and nitro-blue tetrazolium reduction, demonstrated that the granulocytes were functionally unimpaired following preparation of the concentrates. These studies suggest that concentrates of functional granulocytes, suitable for transfusion to neonatal patients, can be prepared from fresh units of whole blood, using a cell processor. This procedure is more cost-effective than leukapheresis and allows for delivery of granulocytes for transfusion in a more timely fashion.

Development of a strontium chronic effects benchmark for aquatic life in freshwater.

PubMed

McPherson, Cathy A; Lawrence, Gary S; Elphick, James R; Chapman, Peter M

2014-11-01

There are no national water-quality guidelines for strontium for the protection of freshwater aquatic life in North America or elsewhere. Available data on the acute and chronic toxicity of strontium to freshwater aquatic life were compiled and reviewed. Acute toxicity was reported to occur at concentrations ranging from 75 mg/L to 15 000 mg/L. The majority of chronic effects occurred at concentrations above 11 mg/L; however, calculation of a representative benchmark was confounded by results from 4 studies indicating that chronic effects occurred at lower concentrations than all other studies, in 2 cases below background concentrations reported for US and European streams. Two of these studies, including 1 reporting effects below background concentrations, were repeated and found not to be reproducible; chronic effects occurred at considerably higher strontium concentrations than in the original studies. Studies with narrow-mouthed toad and goldfish were not repeated; both studies reported chronic effects below background concentrations, and both studies had been conducted by the authors of 1 of the 2 studies that were repeated and shown to be nonreproducible. Studies by these authors (3 of the 4 confounding studies), conducted over 30 yr ago, lacked detail in reporting of methods and results. It is thus likely that repeating the toad and goldfish studies would also have resulted in a higher strontium effects concentration. A strontium chronic effects benchmark of 10.7 mg/L that incorporates the results of additional testing summarized in the present study is proposed for freshwater environments. © 2014 SETAC.

Status and understanding of groundwater quality in the San Francisco Bay groundwater basins, 2007—California GAMA Priority Basin Project

USGS Publications Warehouse

Parsons, Mary C.; Kulongoski, Justin T.; Belitz, Kenneth

2013-01-01

Groundwater quality in the approximately 620-square-mile (1,600-square-kilometer) San Francisco Bay study unit was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is located in the Southern Coast Ranges of California, in San Francisco, San Mateo, Santa Clara, Alameda, and Contra Costa Counties. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory. The GAMA San Francisco Bay study was designed to provide a spatially unbiased assessment of the quality of untreated groundwater within the primary aquifer system, as well as a statistically consistent basis for comparing water quality throughout the State. The assessment is based on water-quality and ancillary data collected by the USGS from 79 wells in 2007 and is supplemented with water-quality data from the California Department of Public Health (CDPH) database. The primary aquifer system is defined by the depth interval of the wells listed in the CDPH database for the San Francisco Bay study unit. The quality of groundwater in shallower or deeper water-bearing zones may differ from that in the primary aquifer system; shallower groundwater may be more vulnerable to surficial contamination. The first component of this study, the status of the current quality of the groundwater resource, was assessed by using data from samples analyzed for volatile organic compounds (VOCs), pesticides, and naturally occurring inorganic constituents, such as major ions and trace elements. Water- quality data from the CDPH database also were incorporated for this assessment. This status assessment is intended to characterize the quality of groundwater resources within the primary aquifer system of the San Francisco Bay study unit, not the treated drinking water delivered to consumers by water purveyors. Relative-concentrations (sample concentration divided by the benchmark concentration) were used for evaluating groundwater quality for those constituents that have Federal and (or) California benchmarks. A relative-concentration greater than (>) 1.0 indicates a concentration greater than a benchmark, and a relative-concentration less than or equal to (≤) 1.0 indicates a concentration equal to or less than a benchmark. Relative-concentrations of organic and special-interest constituents were classified as low (relative- concentration ≤ 0.1), moderate (0.1 1.0). Inorganic constituent relative- concentrations were classified as low (relative-concentration ≤ 0.5), moderate (0.5 1.0). A lower threshold value of relative-concentration was used to distinguish between low and moderate values of organic constituents because organic constituents are generally less prevalent and have smaller relative-concentrations than naturally occurring inorganic constituents. Aquifer-scale proportion was used as the metric for evaluating regional-scale groundwater quality. High aquifer-scale proportion is defined as the percentage of the primary aquifer system that has relative-concentration greater than 1.0 for a particular constituent or class of constituents; proportion is based on an areal rather than a volumetric basis. Moderate and low aquifer-scale proportions were defined as the percentages of the primary aquifer system that have moderate and low relative-concentrations, respectively. Two statistical approaches—grid-based and spatially weighted—were used to evaluate aquifer-scale proportion for individual constituents and classes of constituents. Grid-based and spatially weighted estimates were comparable in the San Francisco Bay study unit (90-percent confidence intervals). Inorganic constituents with health-based benchmarks were present at high relative-concentrations in 5.1 percent of the primary aquifer system, and at moderate relative-concentrations in 25 percent. The high aquifer-scale proportion of inorganic constituents primarily reflected high aquifer-scale proportions of barium (3.0 percent) and nitrate (2.1 percent). Inorganic constituents with secondary maximum contaminant levels were present at high relative-concentrations in 14 percent of the primary aquifer system and at moderate relative-concentrations in 33 percent. The constituents present at high relative-concentrations included total dissolved solids (7.0 percent), chloride (6.1 percent), manganese (12 percent), and iron (3.0 percent). Organic constituents with health-based benchmarks were present at high relative-concentrations in 0.6 percent and at moderate relative-concentrations in 12 percent of the primary aquifer system. Of the 202 organic constituents analyzed for, 32 were detected. Three organic constituents were frequently detected (in 10 percent or more of samples): the trihalomethane chloroform, the solvent 1,1,1-trichloroethane and the refrigerant 1,1,2-trichlorotrifluoroethane. One special-interest constituent, perchlorate, was detected at moderate relative-concentrations in 42 percent of the primary aquifer system. The second component of this work, the understanding assessment, identified some of the primary natural and human factors that may affect groundwater quality by evaluating land use, physical characteristics of the wells, and geochemical conditions of the aquifer. Results from these evaluations were used to explain the occurrence and distribution of constituents in the study unit.

The evaluation of hollow-fiber ultrafiltration and celite concentration of enteroviruses, adenoviruses and bacteriophage from different water matrices.

PubMed

Rhodes, Eric R; Huff, Emma M; Hamilton, Douglas W; Jones, Jenifer L

2016-02-01

The collection of waterborne pathogen occurrence data often requires the concentration of microbes from large volumes of water due to the low number of microorganisms that are typically present in environmental and drinking waters. Hollow-fiber ultrafiltration (HFUF) has shown promise in the recovery of various microorganisms. This study has demonstrated that the HFUF primary concentration method is effective at recovering bacteriophage φX174, poliovirus, enterovirus 70, echovirus 7, coxsackievirus B4 and adenovirus 41 from large volumes of tap and river water with an average recovery of all viruses of 73.4% and 81.0%, respectively. This study also evaluated an effective secondary concentration method using celite for the recovery of bacteriophage and enteric viruses tested from HFUF concentrates of both matrices. Overall, the complete concentration method (HFUF primary concentration plus celite secondary concentration) resulted in a concentration factor of 3333 and average recoveries for all viruses from tap and river waters of 60.6% and 60.0%, respectively. Published by Elsevier B.V.

Oxidation of danofloxacin by free chlorine-kinetic study, structural identification of by-products by LC-MS/MS and potential toxicity of by-products using in silico test.

PubMed

Yassine, Montaha; Rifai, Ahmad; Doumyati, Samah; Trivella, Aurélien; Mazellier, Patrick; Budzinski, Hélène; Al Iskandarani, Mohamad

2017-03-01

In this study, we aimed to investigate the kinetics and the mechanism of reaction of the fluoroquinolone antibacterial danofloxacin (DANO) by free available chlorine (FAC) during water chlorination process. Kinetic study was thus performed at pH 7.2, 20 °C in the presence of an excess of total chlorine. Under these experimental conditions, a second-order reaction rate constant (first-order relative to DANO concentration and first-order relative to FAC concentration) was evaluated to k~1446 M -1  s -1 . Five degradation products were identified at different reaction times. Their structures were investigated by using fragmentations obtained at different CID collision energies in MS/MS experiments. Moreover, the toxicity of the proposed structures was predicted by using T.E.S.T. The results indicated that all by-products may have a developmental toxicity. The oral rat LD 50 concentration was predicted to be lower than that of DANO. Furthermore, two degradation compounds presented a concentration level for fathead minnow LC 50 (96 h) lower than that of DANO and presented toxicity for the marine animals.

Evaluation of Novel Large Cut-Off Ultrafiltration Membranes for Adenovirus Serotype 5 (Ad5) Concentration

PubMed Central

Peixoto, Cristina; Roederstein, Susanne; Schleuss, Tobias; Alves, Paula M.; Mota, José P. B.; Carrondo, Manuel J. T.

2014-01-01

The purification of virus particles and viral vectors for vaccine and gene therapy applications is gaining increasing importance in order to deliver a fast, efficient, and reliable production process. Ultrafiltration (UF) is a widely employed unit operation in bioprocessing and its use is present in several steps of the downstream purification train of biopharmaceuticals. However, to date few studies have thoroughly investigated the performance of several membrane materials and cut-offs for virus concentration/diafiltration. The present study aimed at developing a novel class of UF cassettes for virus concentration/diafiltration. A detailed study was conducted to evaluate the effects of (i) membrane materials, namely polyethersulfone (PES), regenerated cellulose (RC), and highly cross-linked RC (xRC), (ii) nominal cut-off, and (iii) UF device geometry at different production scales. The results indicate that the xRC cassettes with a cut-off of approximately 500 kDa are able to achieve a 10-fold concentration factor with 100% recovery of particles with a process time twice as fast as that of a commercially available hollow fiber. DNA and host cell protein clearances, as well as hydraulic permeability and fouling behavior, were also assessed. PMID:25546428

Phenolic compounds in Ross Sea water

NASA Astrophysics Data System (ADS)

Zangrando, Roberta; Barbaro, Elena; Gambaro, Andrea; Barbante, Carlo; Corami, Fabiana; Kehrwald, Natalie; Capodaglio, Gabriele

2016-04-01

Phenolic compounds are semi-volatile organic compounds produced during biomass burning and lignin degradation in water. In atmospheric and paleoclimatic ice cores studies, these compounds are used as biomarkers of wood combustion and supply information on the type of combusted biomass. Phenolic compounds are therefore indicators of paleoclimatic interest. Recent studies of Antarctic aerosols highlighted that phenolic compounds in Antarctica are not exclusively attributable to biomass burning but also derive from marine sources. In order to study the marine contribution to aerosols we developed an analytical method to determine the concentration of vanillic acid, vanillin, p-coumaric acid, syringic acid, isovanillic acid, homovanillic acid, syringaldehyde, acetosyringone and acetovanillone present in dissolved and particle phases in Sea Ross waters using HPLC-MS/MS. The analytical method was validated and used to quantify phenolic compounds in 28 sea water samples collected during a 2012 Ross Sea R/V cruise. The observed compounds were vanillic acid, vanillin, acetovanillone and p-coumaric acid with concentrations in the ng/L range. Higher concentrations of analytes were present in the dissolved phase than in the particle phase. Sample concentrations were greatest in the coastal, surficial and less saline Ross Sea waters near Victoria Land.

Numerical study of underwater dispersion of dilute and dense sediment-water mixtures

NASA Astrophysics Data System (ADS)

Chan, Ziying; Dao, Ho-Minh; Tan, Danielle S.

2018-05-01

As part of the nodule-harvesting process, sediment tailings are released underwater. Due to the long period of clouding in the water during the settling process, this presents a significant environmental and ecological concern. One possible solution is to release a mixture of sediment tailings and seawater, with the aim of reducing the settling duration as well as the amount of spreading. In this paper, we present some results of numerical simulations using the smoothed particle hydrodynamics (SPH) method to model the release of a fixed volume of pre-mixed sediment-water mixture into a larger body of quiescent water. Both the sediment-water mixture and the “clean” water are modeled as two different fluids, with concentration-dependent bulk properties of the sediment-water mixture adjusted according to the initial solids concentration. This numerical model was validated in a previous study, which indicated significant differences in the dispersion and settling process between dilute and dense mixtures, and that a dense mixture may be preferable. For this study, we investigate a wider range of volumetric concentration with the aim of determining the optimum volumetric concentration, as well as its overall effectiveness compared to the original process (100% sediment).

Resting state glutamate predicts elevated pre-stimulus alpha during self-relatedness: A combined EEG-MRS study on "rest-self overlap".

PubMed

Bai, Yu; Nakao, Takashi; Xu, Jiameng; Qin, Pengmin; Chaves, Pedro; Heinzel, Alexander; Duncan, Niall; Lane, Timothy; Yen, Nai-Shing; Tsai, Shang-Yueh; Northoff, Georg

2016-01-01

Recent studies have demonstrated neural overlap between resting state activity and self-referential processing. This "rest-self" overlap occurs especially in anterior cortical midline structures like the perigenual anterior cingulate cortex (PACC). However, the exact neurotemporal and biochemical mechanisms remain to be identified. Therefore, we conducted a combined electroencephalography (EEG)-magnetic resonance spectroscopy (MRS) study. EEG focused on pre-stimulus (e.g., prior to stimulus presentation or perception) power changes to assess the degree to which those changes can predict subjects' perception (and judgment) of subsequent stimuli as high or low self-related. MRS measured resting state concentration of glutamate, focusing on PACC. High pre-stimulus (e.g., prior to stimulus presentation or perception) alpha power significantly correlated with both perception of stimuli judged to be highly self-related and with resting state glutamate concentrations in the PACC. In sum, our results show (i) pre-stimulus (e.g., prior to stimulus presentation or perception) alpha power and resting state glutamate concentration to mediate rest-self overlap that (ii) dispose or incline subjects to assign high degrees of self-relatedness to perceptual stimuli.

Degradation of pharmaceuticals in non-sterile urban wastewater by Trametes versicolor in a fluidized bed bioreactor.

PubMed

Cruz-Morató, Carles; Ferrando-Climent, Laura; Rodriguez-Mozaz, Sara; Barceló, Damià; Marco-Urrea, Ernest; Vicent, Teresa; Sarrà, Montserrat

2013-09-15

The constant detection of pharmaceuticals (PhACs) in the environment demonstrates the inefficiency of conventional wastewater treatment plants to completely remove them from wastewaters. So far, many studies have shown the feasibility of using white rot fungi to remove these contaminants. However, none of them have studied the degradation of several PhACs in real urban wastewater under non-sterile conditions, where mixtures of contaminants presents at low concentrations (ng L(-1) to μg L(-1)) as well as other active microorganisms are present. In this work, a batch fluidized bed bioreactor was used to study, for the first time, the degradation of PhACs present in urban wastewaters at their pre-existent concentrations under non-sterile conditions. Glucose and ammonium tartrate were continuously supplied as carbon and nitrogen source, respectively, and pH was maintained at 4.5. Complete removal of 7 out of the 10 initially detected PhACs was achieved in non-sterile treatment, while only 2 were partially removed and 1 of the PhACs analyzed increased its concentration. In addition, Microtox test showed an important reduction of toxicity in the wastewater after the treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Inhibition of the nitrification process in activated sludge by trivalent and hexavalent chromium, and partitioning of hexavalent chromium between sludge compartments.

PubMed

Novotnik, Breda; Zuliani, Tea; Ščančar, Janez; Milačič, Radmila

2014-06-01

The input of wastewater treatment plants (WWTPs) may contain high concentrations of Cr(III) and Cr(VI), which can affect nitrogen removal. In the present study the influence of different Cr(III) and Cr(VI) concentrations towards activated sludge nitrification was studied. To better understand the mechanisms of Cr(VI) toxicity, its reduction, adsorption and uptake in activated sludge was investigated in a batch growth system. Quantification of Cr(VI) was performed by speciated isotope dilution inductively coupled plasma mass spectrometry. It was found that Cr(VI) concentrations above 1.0 mg L(-1) and Cr(III) concentrations higher than 50 mg L(-1) negatively affected nitrification. Speciation studies indicated almost complete reduction of Cr(VI) after 24h of incubation when Cr(VI) concentrations were lower than 2.5 mg L(-1), whereas for Cr(VI) added to 5 mg L(-1) around 40% remained unreduced. The study of the partitioning of Cr in the activated sludge was performed by the addition of Cr(VI) in concentrations of 2.5 and 5.0 mg L(-1). Results revealed that Cr was allocated mainly within the intercellular compartments, whereas intracellular and adsorbed Cr represented less than 0.1% of the Cr sludge concentrations. Cr(VI) was reduced in all compartments, the most efficiently (about 94%) within the intracellular and intercellular fractions. The extent of reduction of adsorbed Cr was 92% and 80% for 2.5 and 5.0mg of Cr(VI) L(-1), respectively. The results of present investigation provide a new insight into the toxicity of Cr species towards activated sludge nitrification, which is of significant importance for the management of WWTPs in order to prevent them from inflows containing harmful Cr(VI) concentrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Intraperitoneal Vancomycin Concentrations During Peritoneal Dialysis–Associated Peritonitis: Correlation with Serum Levels

PubMed Central

Fish, Richard; Nipah, Robert; Jones, Chris; Finney, Hazel; Fan, Stanley L.S.

2012-01-01

♦ Background: For the treatment of peritoneal dialysis–associated peritonitis (PDP), it has been suggested that serum concentrations of vancomycin be kept above 12 mg/L – 15 mg/L. However, studies correlating vancomycin concentrations in serum and peritoneal dialysate effluent (PDE) during active infection are sparse. We undertook the present study to investigate this issue and to determine whether achieving the recommended serum level of vancomycin results in therapeutic levels intraperitoneally. ♦ Methods: We studied patients treated with intraperitoneal (IP) vancomycin for non-gram-negative PDP. We gave a single dose (approximately 30 mg/kg) at presentation, and we subsequently measured vancomycin levels in PDE on day 5; we wanted to determine if efflux of vancomycin from serum to PDE during a 4-hour dwell was consistent and resulted in therapeutic levels. ♦ Results: Of the 48 episodes of PDP studied, serum vancomycin concentrations exceeding 12 mg/L were achieved in 98% of patients, but in 11 patients (23%), a PDE vancomycin level below 4 mg/L—the minimal inhibitory concentration (MIC) of many gram-positive organisms—was observed at the end of a 4-hour dwell on day 5. The correlation between the concentrations of vancomycin in serum and PDE (from efflux of antibiotic over 4 hours) was statistically significant, but poor (R2 = 0.18). ♦ Conclusions: Our data support the International Society for Peritoneal Dialysis statement that adequate serum vancomycin concentrations can be achieved with intermittent dosing (single dose every 5 days), but cannot guarantee therapeutic PDE levels in the treatment of PDP. Intermittent dosing of vancomycin may not consistently result in PDE concentrations markedly greater than MIC of many important pathogens. Although the clinical significance of this finding remains to be determined, it may be preferable to give smaller but more frequent doses of PDE vancomycin (continuous dosing) for adults with PDP (as is currently recommended for children). PMID:22045102

To study the effect of different electrolytes and their concentrations on electrochemical micromachining

NASA Astrophysics Data System (ADS)

Singh, Ramandeep

2018-04-01

The machining of materials on micro-meter and sub-micrometre is considered the technology of future. Due to challenging applications of biomedical and aerospace industries, the traditional manufacturing techniques lacks in dimensional accuracy. Thus for such industries, the technique that can control micron tolerances is Electrochemical Micromachining (EMM). Hard metals and alloys can also be machined by this technique. Thus to develop a novel EMM system setup and to investigate the effect of three different electrolytes i.e NaCl, NaNO3 and HCl with their different concentrations, the current study was conducted. Stainless Steel-304 and copper were chosen as the work piece material in the present study. Taguchi L18 orthogonal array was used for the best combination of experiment. According to the present investigation most prominent factor affecting the material removal (MR) comes out was electrolyte. HCl provides the better MR among other electrolytes i.e. NaNO3 and NaCl. The amount of MR increased with the increase in the concentration of electrolyte.

Water reclamation during drinking water treatments using polyamide nanofiltration membranes on a pilot scale.

PubMed

Kukučka, Miroslav; Kukučka, Nikoleta; Habuda-Stanić, Mirna

2016-09-01

The aim of this study was to investigate the performances of polyamide nanofiltration membranes during water reclamation. The study was conducted using nanofiltration concentrates obtained from two different nanofiltration drinking water treatment plants placed in the northern part of Serbia (Kikinda and Zrenjanin). Used nanofiltration concentrates contained high concentrations of arsenic (45 and 451 μg/L) and natural organic matter (43.1 and 224.40 mgKMnO4/L). Performances of polyamide nanofiltration membranes during water reclamation were investigated under various fluxes and transmembrane pressures in order to obtain drinking water from nanofiltration concentrates and, therefore, reduce the amount of produced concentrates and minimize the waste that has to be discharged in the environment. Applied polyamide nanofiltration membranes showed better removal efficiency during water reclamation when the concentrate with higher content of arsenic and natural organic matter was used while the obtained permeates were in accordance with European regulations. This study showed that total concentrate yield can be reduced to ~5 % of the optimum flux value, in both experiments. The obtained result for concentrate yield under the optimum flux presents considerable amount of reclaimed drinking water and valuable reduced quantity of produced wastewater.

Benthic macrofauna assemblages and biochemical properties of sediments in two Antarctic regions differently affected by climate change

NASA Astrophysics Data System (ADS)

Sañé, E.; Isla, E.; Gerdes, D.; Montiel, A.; Gili, J.-M.

2012-03-01

Lipid, protein and carbohydrate concentrations have been determined in sediment cores from the continental shelf in the South Eastern Weddell Sea (SEWS), where no ice shelves have been present at least for thousands of years, and the continental shelf off the Eastern Antarctic Peninsula (EAP), in the area where two ice shelf collapses occurred in 1995 and 2002. On one hand, SEWS presents an important flux of fresh organic matter to the seabed during summer, whereas on the other hand, the presence of ice shelves in EAP hampered photosynthesis restricting the input of organic matter to advected refractory material. In the present study, biochemical variables and benthic macrofauna abundance, biomass and diversity confirmed differences between the two regions. Lipid concentrations were higher in SEWS than in EAP, whereas carbohydrate concentrations were higher in the latter region. These differences were attributed to the higher concentration of labile and refractory material, respectively. Biomass, abundance and diversity of the macrofauna were higher in SEWS than in EAP, where benthic communities started receiving a fresh organic matter input only after the recent ice shelf collapses. As regards macrofauna composition, both regions presented macrobenthic communities associated to early stages of recolonization.

Enzymatic analysis of α-ketoglutaramate—A biomarker for hyperammonemia

PubMed Central

Halámková, Lenka; Mailloux, Shay; Halámek, Jan; Cooper, Arthur J.L.; Katz, Evgeny

2012-01-01

Two enzymatic assays were developed for the analysis of α-ketoglutaramate (KGM)—an important biomarker of hepatic encephalopathy and other hyperammonemic diseases. In both procedures, KGM is first converted to α-ketoglutarate (KTG) via a reaction catalyzed by ω-amidase (AMD). In the first procedure, KTG generated in the AMD reaction initiates a biocatalytic cascade in which the concerted action of alanine transaminase and lactate dehydrogenase results in the oxidation of NADH. In the second procedure, KTG generated from KGM is reductively aminated, with the concomitant oxidation of NADH, in a reaction catalyzed by L-glutamic dehydrogenase. In both assays, the decrease in optical absorbance (λ=340 nm) corresponding to NADH oxidation is used to quantify concentrations of KGM. The two analytical procedures were applied to 50% (v/v) human serum diluted with aqueous solutions containing the assay components and spiked with concentrations of KGM estimated to be present in normal human plasma and in plasma from hyperammonemic patients. Since KTG is the product of AMD-catalyzed hydrolysis of KGM, in a separate study, this compound was used as a surrogate for KGM. Statistical analyses of samples mimicking the concentration of KGM assumed to be present in normal and pathological concentration ranges were performed. Both enzymatic assays for KGM were confirmed to discriminate between the predicted normal and pathophysiological concentrations of the analyte. The present study is the first step toward the development of a clinically useful probe for KGM analysis in biological fluids. PMID:23141304

Comparative studies on testicular and epididymal morphology, and serum hormone concentrations in foxes and the hybrids during the breeding season.

PubMed

Yang, T A; Yang, Y H; Peng, Y H; Cong, B; Diao, Y F; Bao, K; Hu, P F; Song, X C; Liu, L L; Yang, Y F; Xing, X M; Yang, F H

2016-05-01

The silver fox and the blue fox belong to different genera, and the hybrid males are fully or partially sterile. In the present study, the objective was to evaluate the causes of hybrid male sterility, and therefore analyze the differences in testicular, and epididymal morphology and serum hormone concentrations among silver foxes, blue foxes, and the hybrids during the breeding season. Samples were collected from 20 male silver foxes, 20 male blue foxes, 15 male HSBs (silver fox female × blue fox male hybrids) and 14 male HBSs (blue fox male × silver fox female hybrids), respectively. Seminal evaluation showed large numbers of sperm present in the semen of blue foxes and silver foxes, but no sperm present in the hybrids. Mean testicular volume and the diameter of seminiferous tubules in silver foxes and blue foxes were greater than in the hybrids; and there were many Sertoli cells, spermatogenic cells, and sperm in silver foxes and blue foxes, while spermatogenic cells decreased with no sperm in the hybrids. Mean serum LH and prolactin concentrations in silver foxes and blue foxes were less and testosterone was greater than in the hybrids (P<0.05). The results indicate that germ cell meioses in the hybrids were arrested at the prophase stage of meiosis, and that lesser concentrations of testosterone and greater concentrations of LH and prolactin can inhibit the completion of spermatogenesis. Copyright © 2016 Elsevier B.V. All rights reserved.

Cyclic Adenosine Monophosphate Regulation of Ion Transport in Porcine Vocal Fold Mucosae

PubMed Central

Sivasankar, Mahalakshmi; Nofziger, Charity; Blazer-Yost, Bonnie

2012-01-01

Objectives/Hypothesis Cyclic adenosine monophosphate (cAMP) is an important biological molecule that regulates ion transport and inflammatory responses in epithelial tissue. The present study examined whether the adenylyl cyclase activator, forskolin, would increase cAMP concentration in porcine vocal fold mucosa and whether the effects of increased cAMP would be manifested as a functional increase in transepithelial ion transport. Additionally, changes in cAMP concentrations following exposure to an inflammatory mediator, tumor necrosis factor-α (TNFα) were investigated. Study Design In vitro experimental design with matched treatment and control groups. Methods Porcine vocal fold mucosae (N = 30) and tracheal mucosae (N = 20) were exposed to forskolin, TNFα, or vehicle (dimethyl sulfoxide) treatment. cAMP concentrations were determined with enzyme-linked immunosorbent assay. Ion transport was measured using electrophysiological techniques. Results Thirty minute exposure to forskolin significantly increased cAMP concentration and ion transport in porcine vocal fold and tracheal mucosae. However, 30-minute and 2-hour exposure to TNFα did not significantly alter cAMP concentration. Conclusions We demonstrate that forskolin-sensitive adenylyl cyclase is present in vocal fold mucosa, and further, that the product, cAMP increases vocal fold ion transport. The results presented here contribute to our understanding of the intracellular mechanisms underlying vocal fold ion transport. As ion transport is important for maintaining superficial vocal fold hydration, data demonstrating forskolin-stimulated ion transport in vocal fold mucosa suggest opportunities for developing pharmacological treatments that increase surface hydration. PMID:18596479

A consumer-based approach to salt reduction: Case study with bread.

PubMed

Antúnez, Lucía; Giménez, Ana; Ares, Gastón

2016-12-01

In recent years high sodium intake has raised growing concern worldwide. A widespread reduction of salt concentration in processed foods has been claimed as one of the most effective strategies to achieve a short-term impact on global health. However, one of the major challenges in reducing salt in food products is its potential negative impact on consumer perception. For this reason, gradual salt reduction has been recommended. In this context, the aim of the present work was to present a consumer-based approach to salt reduction, using bread as case study. Two consumer studies with a total of 303 consumers were carried out. In the first study, four sequential difference thresholds were determined through paired-comparison tests, starting at a salt concentration of 2%. In the second study, 99 consumers performed a two-bite evaluation of their sensory and hedonic perception of five bread samples: a control bread containing 2% salt and four samples with reduced salt content according to the difference thresholds determined in the first study. Survival analysis was used to determine average difference thresholds, which ranged from 9.4% to 14.3% of the salt concentration of the control bread. Results showed that salt concentration significantly influenced consumer overall liking of the bread samples. However, large heterogeneity was found in consumer hedonic reaction towards salt reduction: two groups of consumers with different preference and hedonic sensitivity to salt reduction were found. Results from the present work confirm that cumulative series of small salt reductions may be a feasible strategy for reducing the sodium content of bread without affecting consumer hedonic perception and stress the importance of considering consumer perception in the design of gradual salt reduction programmes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Aerogel volatiles concentrator and analyzer (AVCA) - Collection and concentration of trace volatile organics in aerogel for spectroscopic detection

NASA Astrophysics Data System (ADS)

Tsapin, A.; Jones, S.; Petkov, M.; Borchardt, D.; Anderson, M.

2017-03-01

A study was conducted to determine the efficacy of using silica aerogel to collect and concentrate ambient trace organics for spectroscopic analysis. Silica aerogel was exposed to atmospheres containing trace amounts of polycyclic aromatic and aliphatic hydrocarbons. The organics present were concentrated in the aerogels by factors varying from 10 to more than 1000 over the levels found in the atmospheres, depending on the specific organic present. Since silica aerogel is transparent over a wide range of optical and near infrared wavelengths, UV-induced fluorescence, Raman and infrared spectroscopies were used to detect and identify the organics collected by the aerogel. Measurements were conducted to determine the sensitivity of these spectroscopic methods for determining organics concentrated by aerogels and the effectiveness of this method for identifying systems containing multiple organic species. Polycyclic aromatic hydrocarbons (PAHs) were added to simulated Mars regolith and then vaporized by modest heating in the presence of aerogel. The aerogels adsorbed and concentrated the PAHs, which were detected by induced fluorescence and Raman and FTIR spectroscopies.

Hg-contaminated terrestrial spiders pose a potential risk to songbirds at Caddo Lake (Texas/Louisiana, USA).

PubMed

Gann, Gretchen L; Powell, Cleveland H; Chumchal, Matthew M; Drenner, Ray W

2015-02-01

Methylmercury (MeHg) is an environmental contaminant that can have adverse effects on wildlife. Because MeHg is produced by bacteria in aquatic ecosystems, studies of MeHg contamination of food webs historically have focused on aquatic organisms. However, recent studies have shown that terrestrial organisms such as songbirds can be contaminated with MeHg by feeding on MeHg-contaminated spiders. In the present study, the authors examined the risk that MeHg-contaminated terrestrial long-jawed orb weaver spiders (Tetragnatha sp.) pose to songbirds at Caddo Lake (Texas/Louisiana, USA). Methylmercury concentrations in spiders were significantly different in river, wetland, and open-water habitats. The authors calculated spider-based wildlife values (the minimum spider MeHg concentrations causing physiologically significant doses in consumers) to assess exposure risks for arachnivorous birds. Methylmercury concentrations in spiders exceeded wildlife values for Carolina chickadee (Poecile carolinensis) nestlings, with the highest risk in the river habitat. The present study indicates that MeHg concentrations in terrestrial spiders vary with habitat and can pose a threat to small-bodied nestling birds that consume large amounts of spiders at Caddo Lake. This MeHg threat to songbirds may not be unique to Caddo Lake and may extend throughout the southeastern United States. © 2014 SETAC.

Determination of heavy metal levels in water, sediment and tissues of tench (Tinca tinca L., 1758) from Beyşehir Lake (Turkey).

PubMed

Tekin-Ozan, Selda

2008-10-01

In the present study, some heavy metals (Cu, Fe, Zn and Mn) were seasonally determined in water, sediment and some tissues of fish Tinca tinca from Beyşehir Lake, which is an important bird nesting and visiting area, a water source for irrigation and drinking. In the water, Fe has the highest concentrations among the studied metals. Generally, the metal concentrations increased in the hottest period decreased in warm seasons. Results for levels in water were compared with national and international water quality guidelines, as well as literature data reported for the lakes. Fe was the highest in sediment samples, also Cu and Zn were the highest in spring, while Fe and Mn were in autumn. Among the heavy metals studied, Cu and Mn were below the detection limits in some tissues. Generally, higher concentrations of the tested metals were found in the summer and winter, compared with those during the autumn and spring seasons. High levels of heavy metals were found in liver of T. tinca, while low levels in muscle samples. Metal concentrations in the muscle of examined fish were within the safety permissible levels for human consumption. The present study shows that precautions need to be taken in order to prevent further heavy metal pollution.

Effect of routine prenatal supplementation on vitamin concentrations in maternal serum and breast milk.

PubMed

Sânzio Gurgel, Cristiane Santos; Alves de Araújo Pereira, Larisa; de Assis Costa, Aldiane; Adja da Silva Souza, Mayara; Araújo de Brito, Poliana; Miranda de Melo, Larisse Rayanne; Dimenstein, Roberto

2017-01-01

The aim of the present study was to assess the effect of multivitamin supplements and their different vitamin A sources on retinol concentrations in serum and colostrum milk of postpartum women. This was a retrospective cross-sectional study composed of healthy postpartum women attending two Brazilian private maternity wards (N = 100). According to the type of multivitamin taken during pregnancy, the women were assigned to one of four groups: control group (CG; n = 25), formulation 1 (F1; n = 25), formulation 2 (F2; n = 25), and formulation 3 (F3; n = 25). Blood and colostrum samples were collected under fasting conditions and retinol was analyzed by high-performance liquid chromatography. Dietary vitamin A was assessed using a food frequency questionnaire. Retinol concentrations <20 μg/dL (<0.70 μmol/L) in serum and <60 μg/dL (2.10 μmol/L) in colostrum were considered indicative of vitamin A deficiency. Of women in the control group, 12% (n = 3) presented serum retinol levels below the cut-off value for adequacy; this was not observed in the supplemented groups. Evaluating the retinol content in breast milk, supplemented groups F1 and F3 presented 4% (n = 1) of inadequacy cases, whereas F2 presented 40% (n = 10). The concentrations found in the F2 and F3 groups were statistically different (P < 0.05). The use of multivitamin supplements containing vitamin A during pregnancy prevents vitamin A deficiency regardless of the source administered. In breast milk, supplementation with β-carotene provided a lower concentration of vitamin A compared with retinol. Copyright © 2016 Elsevier Inc. All rights reserved.

Study of Selected Composites Copper Concentrate-Plastic Waste Using Thermal Analysis

NASA Astrophysics Data System (ADS)

Szyszka, Danuta

2017-12-01

The paper presents thermal analysis of selected composites (copper concentrate, plastic waste) in two stages. The first stage consisted in thermogravimetric analysis and differential thermal analysis on the applied plastic waste and copper concentrate, and subsequently, a comparative study has been carried out on products obtained, constituting composites of those materials. As a result of analyses, it was found that up to ca. 400 °C composites show high thermal stability, whereas above that temperature, a thermal decomposition of the composite occurs, resulting in emissions of organic compounds, i.e. hydrocarbon compounds and organic oxygenate derivatives.

Cytotoxic effects of pesticides in somatic cells of Vicia faba L.

PubMed

Pandey, R M

2008-01-01

The effects of pesticides (Endosulfan, Dieldrin, Aldrin) on cell division and chromosomal morphology of Vicia faba L. were studied. The results showed that the pesticides are mitode-pressive in higher concentrations and mitopromotor in lower concentrations and induced a variety of chromosomal abnormalities such as stickiness, fragments, chromatid separation, disturbed metaphase, C-mitosis, laggards, precocious movement and late separation where lagging chromosomes were predominant. The concentration of 500 ppm or above, for all the pesticides used in the present study showed pronounced toxic effect. In remaining treatments, although the milotic index was improved but less than that of absolute controls.

Tropospheric ozone measurements at the equatorial region (1980-1988)

NASA Technical Reports Server (NTRS)

Ilyas, Mohammad

1994-01-01

Results from surface ozone measurements at Penang (5.5 deg N, 100 deg E) over 1980-88 period are presented. The study indicates the ozone concentrations undergoing significant diurnal and seasonal variations. The peak concentration are observed at around mid-day (up to 35 nb) but the O3 concentration generally drops to zero level in the early evening and remains unchanged until mid-morning. Monthly-averaged daily 1-h average concentrations are generally small (4-13 nb) and decrease continually from the early part of the year to the end. Frequently, varying local weather conditions seem to influence the O3 concentrations.

Impacts of fine particulate matter on premature mortality under future climate change

NASA Astrophysics Data System (ADS)

Park, S.; Allen, R.; Lim, C. H.

2016-12-01

Climate change modulates concentration of fine particulate matter (PM2.5) via modifying atmospheric circulation and the hydrological cycle. Furthermore, surface PM2.5 is significantly associated with respiratory diseases and premature mortality. In this study, we assess the response of PM2.5 concentration to climate change in the future (end of 21st century) and its effects on year of life lost (YLL) and premature mortality. We use outputs from five models participating in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) to evaluate climate change effects on PM2.5: for present climate with current aerosol emissions and greenhouse gas concentrations, and for future climate, also with present-day aerosol emissions, but with end-of-the century greenhouse gas concentrations, sea surface temperatures and sea-ice. The results show that climate change is associated with an increase in PM2.5 concentration. Combined with global future population data from the United Nation (UN), we also find an increase in premature mortality and YLL.

Elemental concentration analysis in prostate tissues using total reflection X-ray fluorescence

NASA Astrophysics Data System (ADS)

Leitão, R. G.; Palumbo, A.; Souza, P. A. V. R.; Pereira, G. R.; Canellas, C. G. L.; Anjos, M. J.; Nasciutti, L. E.; Lopes, R. T.

2014-02-01

Prostate cancer (PCa) currently represents the second most prevalent malignant neoplasia in men, representing 21% of all cancer cases. Benign Prostate Hyperplasia (BPH) is an illness prevailing in men above the age of 50, close to 90% after the age of 80. The prostate presents a high zinc concentration, about 10-fold higher than any other body tissue. In this work, samples of human prostate tissues with cancer, BPH and normal tissue were analyzed utilizing total reflection X-ray fluorescence spectroscopy using synchrotron radiation technique (SR-TXRF) to investigate the differences in the elemental concentrations in these tissues. SR-TXRF analyses were performed at the X-ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, São Paulo. It was possible to determine the concentrations of the following elements: P, S, K, Ca, Fe, Cu, Zn and Rb. By using Mann-Whitney U test it was observed that almost all elements presented concentrations with significant differences (α=0.05) between the groups studied.

Trace elements in lenses of normal Wistar Kyoto rats

NASA Astrophysics Data System (ADS)

Kinoshita, Akio; Gong, Huaqing; Amemiya, Tsugio; Takaya, Kenichi; Tozu, Miyako; Ohashi, Yoshiharu

2003-01-01

Chemical analysis of the element and organic substance at the site of pathological changes due to aging is one of the approaches of cataract research. Time of flight secondary ion mass spectrometry (TOF-SIMS) microscopy is expected to analyze elements and organic substances in the lens. The purpose of the present study is to compare elements and organic substances in the lenses of normal 4-month-old rats with those of normal 15-month-old rats by means of a TOF-SIMS microscope. The present study showed that the concentration of Ca and Fe was significantly higher, and that of Na and Mg was significantly lower in 15-month-old rats than that in 4-month-old rats. No changes were found in the concentration of K. The present study also showed that the equator contained more Ca, Na and Mg than the nucleus; in contrast, the Cu concentration was higher in the nucleus than in the equator. In 15-month-old rats, Mg and Vit. A in the equator and Zn in the nucleus were significantly lower than those in 4-month-old rats. TOF-SIMS microscopy could detect elemental changes in the rat lens with age, and is expected to be useful approach of cataract studies.

Integrated microfluidic system with simultaneous emulsion generation and concentration.

PubMed

Koppula, Karuna S; Fan, Rong; Veerapalli, Kartik R; Wan, Jiandi

2016-03-15

Because the size, size distribution, and concentration of emulsions play an important role in most of the applications, controlled emulsion generation and effective concentration are of great interest in fundamental and applied studies. While microfluidics has been demonstrated to be able to produce emulsion drops with controlled size, size distribution, and hierarchical structures, progress of controlled generation of concentrated emulsions is limited. Here, we present an effective microfluidic emulsion generation system integrated with an orifice structure to separate aqueous droplets from the continuous oil phase, resulting in concentrated emulsion drops in situ. Both experimental and simulation results show that the efficiency of separation is determined by a balance between pressure drop and droplet accumulation near the orifice. By manipulating this balance via changing flow rates and microfluidic geometry, we can achieve monodisperse droplets on chip that have a concentration as high as 80,000 drops per microliter (volume fraction of 66%). The present approach thus provides insights to the design of microfluidic device that can be used to concentrate emulsions (drops and bubbles), colloidal particles (drug delivery polymer particles), and biological particles (cells and bacteria) when volume fractions as high as 66% are necessary. Copyright © 2015 Elsevier Inc. All rights reserved.

Combination of surfactant solubilization with permanganate oxidation for DNAPL remediation.

PubMed

Li, Zhaohui; Hanlie, Hong

2008-02-01

A combination of surfactant solubilization with permanganate oxidation of trichloroethylene (TCE) was studied in batch, flow-through column, and three-dimensional (3-D) tank tests. Batch results showed that chloride production, an indication of TCE degradation, followed a pseudo-first-order reaction kinetics with respect to KMnO4 in the presence of free-phase TCE. A higher chloride production rate was achieved when anionic surfactants were present. The observed pseudo-first-order reaction rate constant increased as the concentrations of anionic surfactants Ninate 411 and Calfax increased from 0% to 0.1%, 0.3%, and 1.0%. Column experiments on TCE reduction by permanganate in the presence and absence of surfactants were carried out using well-sorted coarse Ottawa sand. The peak effluent TCE concentration reached 1700 mg/L due to enhanced solubilization when both sodium dodecyl sulfate (SDS) and permanganate were used, in contrast to less than 300 mg/L when only permanganate solution was used. In addition, the effluent TCE concentration decreased much faster when SDS was present in the permanganate solution, compared with the case when SDS was absent. With an initial 1 mL of TCE emplaced in the columns, the effluent TCE concentration dropped to <5mg/L after 29-31h of flushing with 1% SDS and 0.1% KMnO4 solution in contrast to 37-73 h when only 0.1% KMnO4 was used. Furthermore, KMnO4 breakthrough occurred after 21-25 h of injection when SDS was present compared with 45-70 h later when SDS was absent. A slightly higher chloride concentration was observed in the earlier stage of the column experiment and the chloride concentration decreased quickly once KMnO4 was seen in the effluent. The 3-D tank test showed that the MnO2 precipitation front formed more quickly when 1% SDS was present, which further confirmed the observation from the column study.

Transport of oxidized multi-walled carbon nanotubes through silica based porous media: influences of aquatic chemistry, surface chemistry, and natural organic matter.

PubMed

Yang, Jin; Bitter, Julie L; Smith, Billy A; Fairbrother, D Howard; Ball, William P

2013-12-17

This paper provides results from studies of the transport of oxidized multi-walled carbon nanotubes (O-MWCNTs) of varying surface oxygen concentrations under a range of aquatic conditions and through uniform silica glass bead media. In the presence of Na(+), the required ionic strength (IS) for maximum particle attachment efficiency (i.e., the critical deposition concentration, or CDC) increased as the surface oxygen concentration of the O-MWCNTs or pH increased, following qualitative tenets of theories based on electrostatic interactions. In the presence of Ca(2+), CDC values were lower than those with Na(+) present, but were no longer sensitive to surface oxygen content, suggesting that Ca(2+) impacts the interactions between O-MWCNTs and glass beads by mechanisms other than electrostatic alone. The presence of Suwannee River natural organic matter (SRNOM) decreased the attachment efficiency of O-MWCNTs in the presence of either Na(+) or Ca(2+), but with more pronounced effects when Na(+) was present. Nevertheless, low concentrations of SRNOM (<4 mg/L of dissolved organic carbon) were sufficient to mobilize all O-MWCNTs studied at CaCl2 concentrations as high as 10 mM. Overall, this study reveals that NOM content, pH, and cation type show more importance than surface chemistry in affecting O-MWCNTs deposition during transport through silica-based porous media.

Correlation between stressors and academic performance in second year medical students.

PubMed

Nuallaong, Winitra

2011-12-01

The present study aimed to find which type of stressors correlating to academic performance in second year medical students. One-hundred and eighty three second year medical students of Thammasat University participated in a three-week cross-sectional study. The self-report questionnaire consisted of Thai stress test, stress factors and examination grades referring academic performance were applied in the present study. Females felt stress more than males in severe, high, and medium level of stress. There was no low level of stress and no correlation between stress level and the entrance programs. Academic performance found relating to 1) fear of doing a mistake, 2) feeling of competition or comparison, 3) unilateral headache, 4) worrying, and 5) poor concentration. Students with poor concentration had significantly decreasing grade in the second year (p < 0.01). Interestingly, worrying, feeling of competition or comparison, and fear of doing a mistake correlated to increasing grade in some terms (p < 0.05). Specifically to poor concentration, there were medium linear association with fatigue, poor memory, feeling confused, feeling sad, feeling angry or irritable, changing appetite, and headache from stress (p < 0.01). Poor concentration was the only stressor significantly correlated with poorer academic performance. Poor concentration also correlated with physical, cognitive, and financial problems. The recommendation is to keep watching those issues in order to early detect problem about academic performance.

Sensory characteristics and relative sweetness of tagatose and other sweeteners.

PubMed

Fujimaru, Tomomi; Park, Jin-Hee; Lim, Juyun

2012-09-01

The present study investigated the sensory characteristics and relative sweetness of tagatose, an emerging natural low-calorie sweetener with various functional properties, compared to other sweeteners (sucrose, sucralose, erythritol, rebaudioside A), over a wide range of sweetness commonly found in foods and beverages (3% to 20% sucrose [w/v]). A total of 34 subjects evaluated aqueous solutions of the 5 sweeteners for the perceived intensities of sweetness, bitterness, astringency, chemical-like sensations, and sweet aftertaste, using the general version of the Labeled Magnitude Scale. The relationship between the physical concentrations of the sweeteners and their perceived sweetness (that is, psychophysical functions) was derived to quantify the relative sweetness and potency of the sweeteners. The results suggest that tagatose elicits a sweet taste without undesirable qualities (bitterness, astringency, chemical-like sensations). Out of the 5 sweeteners tested, rebaudioside A was the only sweetener with notable bitterness and chemical-like sensations, which became progressively intense with increasing concentration (P < 0.001). In terms of perceived sweetness intensity, the bulk sweeteners (tagatose, erythritol, sucrose) had similar sweetness growth rates (slopes > 1), whereas the high-potency sweeteners (sucralose, rebaudioside A) yielded much flatter sweetness functions (slopes < 1). Because the sweetness of tagatose and sucrose grew at near-identical rates (slope = 1.41 and 1.40, respectively), tagatose produced about the same relative sweetness to sucrose across the concentrations tested. However, the relative sweetness of other sweeteners to sucrose was highly concentration dependent. Consequently, sweetness potencies of other sweeteners varied across the concentrations tested, ranging from 0.50 to 0.78 for erythritol, 220 to 1900 for sucralose, and 300 to 440 for rebaudioside A, while tagatose was estimated to be approximately 0.90 times as potent as sucrose irrespective of concentration. The present study investigated the sensory characteristics and relative sweetness of tagatose, an emerging natural low-calorie sweetener, compared to other sweeteners. Study results suggest that tagatose elicits a sweet taste without undesirable qualities over a wide range of concentrations. Tagatose produced about the same relative sweetness to sucrose across the concentrations tested, while the relative sweetness of other sweeteners was highly concentration dependent. The present data provide a general guideline when considering the use of tagatose and other sweeteners in foods and beverages. © 2012 Institute of Food Technologists®

Concentrated Language Encounter Approach in Practice for Global Teaching of Literacy: Lighthouse Strategy Implementation

ERIC Educational Resources Information Center

Rattanavich, Saowalak

2015-01-01

This article presents the lighthouse literacy strategies model using the concentrated language encounter (CLE) approach that has been successfully replicated in many countries in different languages and cultures. A review of CLE research studies and the project implementation in Thailand showed highly significant results in students' literacy…

Major, Trace Element Concentration and Triple-Oxygen Isotope Compositions of G- and I-Type Spherules from the Sør Rondane Mountains, East Antarctica

NASA Astrophysics Data System (ADS)

Soens, B.; Goderis, S.; Greenwood, R. C.; McKibbin, S.; Van Ginneken, M.; Vanhaecke, F.; Debaille, V.; Franchi, I. A.; Claeys, Ph.

2017-07-01

We present new major, trace element concentration (LA-ICP-MS) and triple-oxygen isotope (LF-IRMS) data for G- and I-type cosmic spherules. This study suggests that both types of micrometeorites may originate from ordinary chondrite parent bodies.

INDOOR AIR CONCENTRATIONS OF ORGANOCHLORINE, ORGANOPHOSPHATE AND PYRETHROID PESTICIDES IN THE US: FOUR STUDIES, SIX STATES AND TWENTY YEARS

EPA Science Inventory

Pesticides used to control indoor pests have transitioned across the chemicals classes of organochlorine, organophosphate, and pyrethroid compounds from the 1980's to the present. This work summarizes the pesticide concentrations measured from the indoor air of homes from four st...

Campus Ecology, Part 2 of a Series: Pond Water

ERIC Educational Resources Information Center

Bryan, R. C.

1974-01-01

Presents a series of activities which focus on the study of the physical characteristics of water, including temperatures, opacity, pH-values, oxygen concentrations, reagents, and free CO2 concentrations. Indicates that ponds can provide the students with opportunities to learn chemistry, geology, biology, botany, and the effects of weather. (CC)

ATMOSPHERIC CONCENTRATIONS OF AMMONIA AND AMMONIUM AT AN AGRICULTURAL SITE IN THE SOUTHEAST UNITED STATES

EPA Science Inventory

In this study, we present approximately 1 year (October 1998 - September 1999) of 12-hour mean ammonia [NH3], ammonium [NH4(+)], hydrochloric acid [HCl], nitrate [NO3(-)], nitric acid [HNO3], nitrous acid [HNO2], sulfate [SO4(- -)], and sulfur dioxide [SO2] concentrations measure...

Parathyroid hormone is not an inhibitor of lipoprotein lipase activity.

PubMed

Arnadottir, M; Nilsson-Ehle, P

1994-01-01

The reduced lipoprotein lipase (LPL) activities in uraemia are reflected by increased serum triglyceride concentrations and reduced HDL cholesterol concentrations. Both hyperparathyroidism and circulating inhibitor(s) of LPL have been associated with the disturbances of lipid metabolism in uraemia. The aim of the present study was to investigate if parathyroid hormone (PTH) had an inhibitory effect on LPL activity. Plasma post-heparin LPL activities, plasma LPL inhibitory activities, serum PTHintact and serum PTHC-terminal concentrations were analysed in 20 patients on haemodialysis and 20 healthy controls. The effects of purified, human PTHintact and a carboxyterminal fragment of PTH (PTH39-84) on LPL activities in post-heparin plasma from healthy individuals and on the enzyme activity of purified, bovine milk LPL, activated with apolipoprotein CII, were studied. Patients had significantly higher plasma LPL inhibitory activities than controls, but there was no correlation between plasma LPL inhibitory activities and serum PTH concentrations. Neither PTHintact nor PTH39-84 had a significant effect on LPL activities in vitro. Thus there was no evidence of a direct inhibition of LPL activity by PTH under the present in-vivo or in-vitro conditions.

Heavy Metals in Surface Soils in the Upper Reaches of the Heihe River, Northeastern Tibetan Plateau, China

PubMed Central

Bu, Jianwei; Sun, Ziyong; Zhou, Aiguo; Xu, Youning; Ma, Rui; Wei, Wenhao; Liu, Meng

2016-01-01

The upper reaches of the Heihe River have been regarded as a hotspot for phytoecology, climate change, water resources and hydrology studies. Due to the cold-arid climate, high elevation, remote location and poor traffic conditions, few studies focused on heavy metal contamination of soils have been conducted or reported in this region. In the present study, an investigation was performed to provide information regarding the concentration levels, sources, spatial distributions, and environmental risks of heavy metals in this area for the first time. Fifty-six surface soil samples collected from the study area were analyzed for Cr, Mn, Ni, Cu, Zn, As, Cd and Pb concentrations, as well as TOC levels. Basic statistics, concentration comparisons, correlation coefficient analysis and multivariate analyses coupled with spatial distributions were utilized to delineate the features and the sources of different heavy metals. Risk assessments, including geoaccumulation index, enrichment factor and potential ecological risk index, were also performed. The results indicate that the concentrations of heavy metals have been increasing since the 1990s. The mean values of each metal are all above the average background values in the Qinghai Province, Tibet, China and the world, except for that of Cr. Of special note is the concentration of Cd, which is extremely elevated compared with all background values. The distinguished ore-forming conditions and well-preserved, widely distributed limestones likely contribute to the high Cd concentration. Heavy metals in surface soils in the study area are primarily inherited from parent materials. Nonetheless, anthropogenic activities may have accelerated the process of weathering. Cd presents a high background concentration level and poses a severe environmental risk throughout the whole region. Soils in Yinda, Reshui daban, Kekeli and Zamasheng in particular pose threats to the health of the local population, as well as that of livestock and wildlife. PMID:26907322

Satellite power systems (SPS) concept definition study. Volume 2, part 1: System engineering

NASA Technical Reports Server (NTRS)

Hanley, G. M.

1980-01-01

Top level trade studies are presented, including comparison of solid state and klystron concepts, higher concentration on the solar cells, composite and aluminum structure, and several variations to the reference concept. Detailed trade studies are presented in each of the subsystem areas (solar array, power distribution, structures, thermal control, attitude control and stationkeeping, microwave transmission, and ground receiving station). A description of the selected point design is also presented.

Effects of surface functionalization on the electronic and structural properties of carbon nanotubes: A computational approach

NASA Astrophysics Data System (ADS)

Ribeiro, M. S.; Pascoini, A. L.; Knupp, W. G.; Camps, I.

2017-12-01

Carbon nanotubes (CNTs) have important electronic, mechanical and optical properties. These features may be different when comparing a pristine nanotube with other presenting its surface functionalized. These changes can be explored in areas of research and application, such as construction of nanodevices that act as sensors and filters. Following this idea, in the current work, we present the results from a systematic study of CNT's surface functionalized with hydroxyl and carboxyl groups. Using the entropy as selection criterion, we filtered a library of 10k stochastically generated complexes for each functional concentration (5, 10, 15, 20 and 25%). The structurally related parameters (root-mean-square deviation, entropy, and volume/area) have a monotonic relationship with functionalization concentration. Differently, the electronic parameters (frontier molecular orbital energies, electronic gap, molecular hardness, and electrophilicity index) present and oscillatory behavior. For a set of concentrations, the nanotubes present spin polarized properties that can be used in spintronics.

Study on the SPR responses of various DNA probe concentrations by parallel scan spectral SPR imaging

NASA Astrophysics Data System (ADS)

Ma, Suihua; Liu, Le; Lu, Weiping; Zhang, Yaou; He, Yonghong; Guo, Jihua

2008-12-01

SPR sensors have become a high sensitive and label free method for characterizing and quantifying chemical and biochemical interactions. However, the relations between the SPR refractive index response and the property (such as concentrations) of biochemical probes are still lacking. In this paper, an experimental study on the SPR responses of varies concentrations of Legionella pneumophila mip DNA probes is presented. We developed a novel two-dimensional SPR sensing technique-parallel scan spectral SPR imaging-to detect an array of mip gene probes. This technique offers quantitative refractive index information with a high sensing throughput. By detecting mip DNA probes with different concentrations, we obtained the relations between the SPR refractive index response and the concentrations of mip DNA probes. These results are valuable for design and developing SPR based mip gene biochips.

Heavy metal distribution in blood, liver and kidneys of Loggerhead (Caretta caretta) and Green (Chelonia mydas) sea turtles from the Northeast Mediterranean Sea.

PubMed

Yipel, Mustafa; Tekeli, İbrahim Ozan; İşler, Cafer Tayer; Altuğ, Muhammed Enes

2017-12-15

The aim of the present study was to determine the concentrations of the most investigated environmentally relevant heavy metals in two highly endangered sea turtle species (Caretta caretta and Chelonia mydas) from the important nesting area on the Northeast Mediterranean Sea. The highest mean concentration was of Fe, while Hg and Pb were lowest. All tissue concentrations of Al, As, Fe and Mn were significantly different between the species. In particular, As, Cd, Cu, Mn, Ni, Se, Zn concentrations were lower in Caretta caretta and Cd, Hg, Mn, Zn concentrations were lower in Chelonia mydas than those reported in other parts of the world. Compared to studies conductud in other parts of the Mediterranean, Cd was lower. Copyright © 2017 Elsevier Ltd. All rights reserved.

Concentrations of levonorgestrel and ethinylestradiol in wastewater effluents: Is the progestin also cause for concern?

PubMed

King, Olivia C; van de Merwe, Jason P; McDonald, James A; Leusch, Frederic D L

2016-06-01

Synthetic hormones have been widely reported in treated sewage effluents, and consequently receiving aquatic environments. Ethinylestradiol (EE2) is a potent synthetic estrogen commonly used in conjunction with levonorgestrel in oral contraceptive pills. Both EE2 and levonorgestrel have been identified in the aquatic environment, but although there is a significant amount of literature on EE2, there is much less information on levonorgestrel. Using Australian prescription data as well as excretion and predicted wastewater removal rates, the concentrations of EE2 and levonorgestrel in Australian wastewater were calculated at 0.1 ng/L to 0.5 ng/L and 0.2 ng/L to 0.6 ng/L, respectively. Both compounds were analyzed in treated wastewater and surface water grab samples from 3 Southeast Queensland, Australia sites. The predicted no-effect concentration (PNEC) for EE2 of 0.1 ng/L was exceeded at most sites, with EE2 concentrations up to 2 ng/L in treated effluent, albeit quickly diluted to 0.1 ng/L to 0.2 ng/L in the receiving environment. A provisional PNEC for levonorgestrel of 0.1 ng/L derived in the present study was slightly lower than predicted effluent concentrations of 0.2 ng/L to 0.6 ng/L, indicating a potential risk of endocrine-related effects in exposed aquatic species. The detection limit for levonorgestrel in the present study was 2.5 ng/L, and all samples were below detection limit. The present study's results suggest that improvements in analytical capabilities for levonorgestrel are warranted to more accurately quantify the risk of this compound in the receiving environment. Environ Toxicol Chem 2016;35:1378-1385. © 2015 SETAC. © 2015 SETAC.

"METHOD": A tool for mechanical, electrical, thermal, and optical characterization of single lens module design

NASA Astrophysics Data System (ADS)

Besson, Pierre; Dominguez, Cesar; Voarino, Philippe; Garcia-Linares, Pablo; Weick, Clement; Lemiti, Mustapha; Baudrit, Mathieu

2015-09-01

The optical characterization and electrical performance evaluation are essential in the design and optimization of a concentrator photovoltaic system. The geometry, materials, and size of concentrator optics are diverse and different environmental conditions impact their performance. CEA has developed a new concentrator photovoltaic system characterization bench, METHOD, which enables multi-physics optimization studies. The lens and cell temperatures are controlled independently with the METHOD to study their isolated effects on the electrical and optical performance of the system. These influences can be studied in terms of their effect on optical efficiency, focal distance, spectral sensitivity, electrical efficiency, or cell current matching. Furthermore, the irradiance map of a concentrator optic can be mapped to study its variations versus the focal length or the lens temperature. The present work shows this application to analyze the performance of a Fresnel lens linking temperature to optical and electrical performance.

Particle concentration and Characteristics near a major freeway with heavy-duty diesel traffic.

PubMed

Ntziachristos, Leonidas; Ning, Zhi; Geller, Michael D; Sioutas, Constantinos

2007-04-01

This study presents the number, surface and volume concentrations, and size distribution of particles next to the 1-710 freeway during February through April 2006. 1-710 has the highest ratio (up to 25%) of heavy-duty diesel vehicles in the Los Angeles highway network. Particle concentration measurements were accompanied by measurements of black carbon, elemental and organic carbon, and gaseous species (CO, CO2). Using the incremental increase of CO2 over the background to calculate the dilution ratio, this study makes it possible to compare particle concentrations measured next to the freeway to concentrations measured in roadway tunnels and in vehicle exhaust. In addition to the effect of the dilution ratio on the measured particle concentrations, multivariate linear regressions showed that light and heavy organic carbon concentrations are positively correlated with the particle volume in the nucleation and accumulation modes, respectively. Solar radiation was also positively correlated with the particle surface concentration and the particle volume in the accumulation (40-638 nm) mode, presumably as a result of secondary particle formation. The methods developed in this study may be used to decouple the effect of sampling position, meteorology, and fleet operation on particle concentrations in the proximity of freeways, roadway tunnels, and in street canyons.

Environmentally-relevant concentrations of atrazine induce non-monotonic acceleration of developmental rate and increased size at metamorphosis in Rhinella arenarum tadpoles.

PubMed

Brodeur, Julie C; Sassone, Alina; Hermida, Gladys N; Codugnello, Nadia

2013-06-01

Despite of the various studies reporting on the subject, anticipating the impacts of the widely-used herbicide atrazine on anuran tadpoles metamorphosis remains complex as increases or decreases of larval period duration are almost as frequently reported as an absence of effect. The aim of the present study was to examine the effects of environmentally-relevant concentrations of atrazine (0.1, 1, 10, 100, and 1000μg/L) on the timings of metamorphosis and body size at metamorphosis in the common South American toad, Rhinella arenarum (Anura: bufonidae). None of the atrazine concentrations tested significantly altered survival. Low atrazine concentrations in the range of 1-100μg/L were found to accelerate developmental rate in a non-monotonic U-shaped concentration-response relationship. This observed acceleration of the metamorphic process occurred entirely between stages 25 and 39; treated tadpoles proceeding through metamorphosis as control animals beyond this point. Together with proceeding through metamorphosis at a faster rate, tadpoles exposed to atrazine concentrations in the range of 1-100μg/L furthermore transformed into significantly larger metamorphs than controls, the concentration-response curve taking the form of an inverted U in this case. The no observed effect concentration (NOEC) was 0.1μg atrazine/L for both size at metamorphosis and timings of metamorphosis. Tadpoles exposed to 100μg/L 17β-estradiol presented the exact same alterations of developmental rate and body size as those treated with 1, 10 and 100μg/L of atrazine. Elements of the experimental design that facilitated the detection of alterations of metamorphosis at low concentrations of atrazine are discussed, together with the ecological significance of those findings. Copyright © 2013 Elsevier Inc. All rights reserved.

Comparative evaluation of effectiveness of sodium dichloroisocyanurate and calcium hydroxide against Candida albicans.

PubMed

Kurian, Jacob; Bolla, Nagesh; Damaraju, Bhargavi

2012-09-01

Candida albicans is the most commonly isolated fungi from the oral cavity. It is the most infective to various intracanal medicaments and is considered as invasive yeast. Sodium dichloroisocyanurate (NaDCC) which is used as a disinfectant and as a biocide in treating potable water has similar action to that of sodium hypochlorite against microbes. The aim of the present study is to compare the effectiveness of calcium hydroxide and NaDCC against Candida albicans. After obtaining the stock cultures of Candida, the isolates were divided into six groups which were exposed to different concentrations of NaDCC and calcium hydroxide Ca(OH)₂. Group 1 consisted of the isolates which were subdivided into three groups, subjected to three different concentrations of NaDCC. Group 2 also consisted of three subgroups exposed to three different concentrations of Ca(OH)₂. Group three consisted of three subgroups which were exposed to three different concentrations of combinations of both NaDCC and Ca(OH)₂. The results of the present study show that calcium hydroxide was totally ineffective at all concentrations and NaDCC was effective and also the combination of both was shown to be effective. NaDCC alone was effective at all concentrations and the combination with Ca(OH)₂ was found to be less effective. Ca(OH)₂ was totally ineffective.

Prediction of an Optimal Dose of Aripiprazole in the Treatment of Schizophrenia From Plasma Concentrations of Aripiprazole Plus Its Active Metabolite Dehydroaripiprazole at Week 1.

PubMed

Nagai, Goyo; Mihara, Kazuo; Nakamura, Akifumi; Nemoto, Kenji; Kagawa, Shoko; Suzuki, Takeshi; Kondo, Tsuyoshi

2017-02-01

It has been suggested that a plasma trough concentration of aripiprazole plus its active metabolite, dehydroaripiprazole of 225 ng/mL is a threshold for a good therapeutic response in the treatment of acutely exacerbated patients with schizophrenia. The present study investigated whether or not an optimal dose of aripiprazole could be predicted from these concentrations at week 1. The subjects were 26 inpatients with schizophrenia, who received aripiprazole once a day for 3 weeks. The daily doses were 12 mg for the first week and 24 mg for the next 2 weeks. No other drugs except biperiden and flunitrazepam were coadministered. Blood samples were taken at weeks 1 and 3 after the treatment. Plasma concentrations of aripiprazole and dehydroaripiprazole were measured using liquid chromatography with mass-spectrometric detection. There was a significant linear relationship between the plasma concentrations of aripiprazole plus dehydroaripiprazole at weeks 1 (x) and 3 (y) (P < 0.001). Regression equation was y = 2.580x + 34.86 (R = 0.698). Based on the equation, a nomogram to estimate an optimal dose of aripiprazole could be constructed. The present study suggests that an optimal dose of aripiprazole for the treatment of patients with schizophrenia can be predicted from the plasma concentrations of the sum of the 2 compounds at week 1.

Fluoride, Nitrate, and Dissolved-Solids Concentrations in Ground Waters of Washington

USGS Publications Warehouse

Lum, W. E.; Turney, Gary L.

1984-01-01

This study provides basic data on ground-water quality throughout the State. It is intended for uses in planning and management by agencies and individuals who have responsibility for or interest in, public health and welfare. It also provides a basis for directing future studies of ground-water quality toward areas where ground-water quality problems may already exist. The information presented is a compilation of existing data from numerous sources including: the Washington Departments of Ecology and Social and Health Services, the Environmental Protection Agency, as well as many other local, county, state and federal agencies and private corporations. Only data on fluoride, nitrate, and dissolved-solids concentrations in ground water are presented, as these constituents are among those commonly used to determine the suitability of water for drinking or other purposes. They also reflect both natural and man-imposed effects on water quality and are the most readily available water-quality data for the State of Washington. The percentage of wells with fluoride, nitrate, or dissolved-solids concentrations exceeding U.S. Environmental Protection Agency Primary and Secondary Drinking Water Regulations were about 1, about 3, and about 3, respectively. Most high concentrations occurred in widely separated wells. Two exceptions were: high concentrations of nitrate and dissolved solids in wells on the Hanford Department of Energy Facility and high concentrations of nitrate in the lower Yakima River basin. (USGS)

Long-term intake of soyabean phytosterols lowers serum TAG and NEFA concentrations, increases bile acid synthesis and protects against fatty liver development in dyslipidaemic hamsters.

PubMed

Laos, Sirle; Caimari, Antoni; Crescenti, Anna; Lakkis, Jamileh; Puiggròs, Francesc; Arola, Lluís; del Bas, Josep Maria

2014-09-14

Various human trials and pre-clinical studies have suggested that dietary plant sterols possess hypotriacylglycerolaemic properties apart from their cholesterol-lowering properties. We hypothesised that phytosterols (PS) might attenuate triacylglycerolaemia by interfering with the deleterious effects of cholesterol overload in the liver. In the present study, twenty hamsters (Mesocricetus auratus) with diet-induced combined hyperlipidaemia were fed a high-fat diet (HFD, n 10) or a HFD supplemented with soyabean PS (n 10) for 40 d. In parallel, a healthy group was fed a standard diet (n 10). PS normalised fasting plasma cholesterol concentrations completely after 20 d and were also able to normalise serum TAG and NEFA concentrations after 40 d. HFD feeding caused microvesicular steatosis and impaired the expression of key genes related to fatty acid oxidation such as PPARA, carnitine palmitoyltransferase-Iα (CPT1A) and phosphoenolpyruvate carboxykinase 1 (PCK1) in the liver. PS treatment completely protected against HFD-induced steatosis and resulted in a normalised hepatic gene expression profile. The protection of the hepatic function by PS was paralleled by increased faecal cholesterol excretion along with a 2-fold increase in the biliary bile acid (BA):cholesterol ratio. The present study supports the conclusion that long-term consumption of PS can reduce serum TAG and NEFA concentrations and can protect against the development of fatty liver via different mechanisms, including the enhancement of BA synthesis. The results of the present study place these compounds as promising hepatoprotective agents against fatty liver and its derived pathologies.

Evaluation of Serum Cytokines in Cats with and without Degenerative Joint Disease and Associated Pain

PubMed Central

Gruen, Margaret E.; Messenger, Kristen M.; Thomson, Andrea E.; Griffith, Emily H.; Aldrich, Lauren A.; Vaden, Shelly; Lascelles, BDX

2017-01-01

Degenerative joint disease is common in cats, with signs of pain frequently found on orthopedic examination and radiographs often showing evidence of disease. However, understanding of the pathophysiology of degenerative joint disease and associated pain remains limited. Several cytokines have been identified as having a role in pain in humans, but this has not been investigated in cats. The present study was performed to use a multiplex platform to evaluate the concentration of 19 cytokines and chemokines in serum samples obtained from cats with and without degenerative joint disease and associated pain. Samples from a total of 186 cats were analyzed, with cats representing a range of severity on radiographic and orthopedic evaluations and categorized by degenerative joint disease scores and pain scores. Results showed that cats with higher radiographic degenerative joint disease scores have higher serum concentrations of IL-4 and IL-8, while cats with higher orthopedic exam pain scores have higher concentrations of IL-8, IL-2, and TNF-α increased concentration of IL-8 in degenerative joint disease and pain may be confounded by the association with age. Discriminant analysis was unable to identify one or more cytokines that distinguish between groups of cats classified based on degenerative joint disease score category or pain score category. Finally, cluster analysis driven by analyte concentrations show separation of groups of cats, but features defining the groups remain unknown. Further studies are warranted to investigate any changes in cytokine concentrations in response to analgesic therapies, and further evaluate the elevations in cytokine concentrations found here, particularly focused on studies of local cytokines present in synovial fluid. PMID:28063477

Blood concentrations of new designer benzodiazepines in forensic cases.

PubMed

Høiseth, Gudrun; Tuv, Silja Skogstad; Karinen, Ritva

2016-11-01

A number of new designer benzodiazepines have reached the illegal drug market over the past years. Toxicological interpretation of concentrations of these drugs in blood is quite challenging as very limited human data have previously been published. The aim of this study was to report blood concentrations of new designer benzodiazepines in a population of drugged drivers as well as some other criminal offenders, and to relate this to clinical impairment. The present material represents cases involving new designer benzodiazepines (clonazolam, diclazepam, flubromazepam, flubromazolam and pyrazolam) and etizolam, submitted for analyses during the period July 1, 2013-May 31, 2016. Analyses were performed using an ultra-performance liquid chromatography-tandem mass spectrometry method. Blood concentrations and results from the clinical test of impairment are reported. New designer benzodiazepines were detected in 77 cases during the study period. The median (range) concentrations were 0.012mg/L (0.00048-0.10) for flubromazolam (n=25), 0.055mg/L (0.0047-1.2) for flubromazepam (n=24), 0.013mg/L (0.0021-0.057) for diclazepam (n=15), 0.050mg/L (0.019-0.17) for etizolam (n=14), 0.0053mg/L (0.0019-0.011) for clonazolam (n=7) and 0.074mg/L for pyrazolam (n=1). In six cases, designer benzodiazepines were the only drugs detected in blood, and in two of those cases, the physician had given the conclusion of "considerably impaired" upon performing the clinical test for impairment. Given the lack of previously published data on human concentrations, results presented in this study could be helpful in interpretation of blood concentrations of new designer benzodiazepines. This is crucial for the assessment of the importance of toxicological results in suspected drugged drivers, rape victims, etc. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The effect of Sao Paulo's smoke-free legislation on carbon monoxide concentration in hospitality venues and their workers.

PubMed

Issa, Jaqueline S; Abe, Tania M O; Pereira, Alexandre C; Megid, Maria Cristina; Shimabukuro, Cristina E; Valentin, Luis Sergio O; Ferreira, Marizete M da C; Nobre, Moacyr R C; Lancarotte, Ines; Barretto, Antonio Carlos Pereira

2011-03-01

Studies have shown that there is no safe level of secondhand smoke (SHS) exposure and there is a close link between SHS and the risk of coronary heart disease and stroke. Carbon monoxide (CO) is one of the most important components present in SHS. To evaluate the impact of the smoking ban law in the city of Sao Paulo, Brazil, on the CO concentration in restaurants, bars, night clubs and similar venues and in their workers. In the present study we measured CO concentration in 585 hospitality venues. CO concentration was measured in different environments (indoor, semi-open and open areas) from visited venues, as well as, in the exhaled air from approximately 627 workers of such venues. Measurements were performed twice, before and 12 weeks after the law implementation. In addition, the quality of the air in the city during the same period of our study was verified. RESULTS The CO concentration pre-ban and pot-ban in hospitality venues was indoor area 4.57 (3.70) ppm vs 1.35 (1.66) ppm (p<0.0001); semi-open 3.79 (2.49) ppm vs 1.16 (1.14) ppm (p<0.0001); open area 3.31(2.2) ppm vs 1.31 (1.39) ppm (p<0.0001); smoking employees 15.78 (9.76) ppm vs 11.50 (7.53) ppm (p<0.0001) and non-smoking employees 6.88 (5.32) ppm vs 3.50 (2.21) ppm (p<0.0001). The average CO concentration measured in the city was lower than 1 ppm during both pre-ban and post-ban periods. São Paulo's smoking-free legislation reduced significantly the CO concentration in hospitality venues and in their workers, whether they smoke or not.

Cu2ZnGeS4 thin films deposited by thermal evaporation: the impact of Ge concentration on physical properties

NASA Astrophysics Data System (ADS)

Courel, Maykel; Sanchez, T. G.; Mathews, N. R.; Mathew, X.

2018-03-01

In this work, the processing of Cu2ZnGeS4 (CZGS) thin films by a thermal evaporation technique starting from CuS, GeS and ZnS precursors, and post-deposition thermal processing, is discussed. Batches of films with GeS layers of varying thicknesses are deposited in order to study the role of Ge concentration on the structural, morphological, optical and electrical properties of CZGS films. The formation of the CZGS compound with a tetragonal phase and a kesterite structure is confirmed for all samples using XRD and Raman studies. An improvement in crystallite size for Ge-poor films is also observed in the XRD analysis, which is in good agreement with the grain size observed in the cross section SEM image. Furthermore, it is found that the band-gap of CZGS film can be tailored in the range of 2.0-2.23 eV by varying Ge concentration. A comprehensive electrical characterization is also performed which demonstrates that slightly Ge-poor samples are described by the lowest grain boundary defect densities and the highest photosensitivity and mobility values. A study of the work function of CZGS samples with different Ge concentrations is also presented. Finally, a theoretical evaluation is presented, considering, under ideal conditions, the possible impact of these films on device performance. Based on the characterization results, it is concluded that Ge-poor CZGS samples deposited by thermal evaporation present better physical properties for device applications.

Uranium concentrations in groundwater, northeastern Washington

USGS Publications Warehouse

Kahle, Sue C.; Welch, Wendy B.; Tecca, Alison E.; Eliason, Devin M.

2018-04-18

A study of uranium in groundwater in northeastern Washington was conducted to make a preliminary assessment of naturally occurring uranium in groundwater relying on existing information and limited reconnaissance sampling. Naturally occurring uranium is associated with granitic and metasedimentary rocks, as well as younger sedimentary deposits, that occur in this region. The occurrence and distribution of uranium in groundwater is poorly understood. U.S. Environmental Protection Agency (EPA) regulates uranium in Group A community water systems at a maximum contaminant level (MCL) of 30 μg/L in order to reduce uranium exposure, protect from toxic kidney effects of uranium, and reduce the risk of cancer. However, most existing private wells in the study area, generally for single family use, have not been sampled for uranium. This document presents available uranium concentration data from throughout a multi-county region, identifies data gaps, and suggests further study aimed at understanding the occurrence of uranium in groundwater.The study encompasses about 13,000 square miles (mi2) in the northeastern part of Washington with a 2010 population of about 563,000. Other than the City of Spokane, most of the study area is rural with small towns interspersed throughout the region. The study area also includes three Indian Reservations with small towns and scattered population. The area has a history of uranium exploration and mining, with two inactive uranium mines on the Spokane Indian Reservation and one smaller inactive mine on the outskirts of Spokane. Historical (1977–2016) uranium in groundwater concentration data were used to describe and illustrate the general occurrence and distribution of uranium in groundwater, as well as to identify data deficiencies. Uranium concentrations were detected at greater than 1 microgram per liter (μg/L) in 60 percent of the 2,382 historical samples (from wells and springs). Uranium concentrations ranged from less than 1 to 88,600 μg/L, and the median concentration of uranium in groundwater for all sites was 1.4 μg/L.New (2017) uranium in groundwater concentration data were obtained by sampling 13 private domestic wells for uranium in areas without recent (2000s) water-quality data. Uranium was detected in all 13 wells sampled for this study; concentrations ranged from 1.03 to 1,180 μg/L with a median of 22 μg/L. Uranium concentrations of groundwater samples from 6 of the 13 wells exceeded the MCL for uranium. Uranium concentrations in water samples from two wells were 1,130 and 1,180 μg/L, respectively; nearly 40 times the MCL.Additional data collection and analysis are needed in rural areas where self-supplied groundwater withdrawals are the primary source of water for human consumption. Of the roughly 43,000 existing water wells in the study area, only 1,755 wells, as summarized in this document, have available uranium concentration data, and some of those data are decades old. Furthermore, analysis of area groundwater quality would benefit from a more extensive chemical-analysis suite including general chemistry in order to better understand local geochemical conditions that largely govern the mobility of uranium. Although the focus of the present study is uranium, it also is important to recognize that there are other radionuclides of concern that may be present in area groundwater.

Dose-dependent inhibitory effects of zoledronic acid on osteoblast viability and function in vitro

PubMed Central

HUANG, XIN; HUANG, SHILONG; GUO, FENGJIN; XU, FEI; CHENG, PENG; YE, YAPING; DONG, YONGHUI; XIANG, WEI; CHEN, ANMIN

2016-01-01

Zoledronic acid (ZA), which is one of the most potent and efficacious bisphosphonates, has been commonly used in clinical practice for the treatment of various bone disorders. The extensive use of ZA has been associated with increasing occurrence of jaw complications, now known as bisphosphonate-associated osteonecrosis of the jaw (BRONJ). However, the mechanism underlying BRONJ remains to be fully elucidated. The aim of the present study was to investigate the effects of different concentrations of ZA on the MC3T3-E1 murine preosteoblast cell line cells and examine the possible pathogenesis of BRONJ. In the present study, the effect of ZA on the viability, apoptosis, differentiation and maturation of MC3T3-E1 cells, as well as its relevant molecular mechanism, were examined The results of a Cell Counting Kit 8 assay, a flow cytometric Annexin-V/propidium iodide assay and western blot analysis demonstrated that ZA exhibited a significant inhibition of cell viability and induction of apoptosis at concentrations >10 µM. Subsequently, the effect of ZA on cell differentiation at concentrations <1 µM were investigated. In this condition, ZA inhibited bone nodule formation and decreased the activity of alkaline phosphatase. The results of reverse transcription-quantitative polymerase chain reaction and western blot analyses indicated that ZA downregulated the expression levels of the marker genes and proteins associated with osteogenic differentiation. Further investigation revealed that the suppression of differentiation by ZA was associated with decreased expression of bone morphogenetic protein-2 (BMP-2) and downregulation of the phosphorylation levels in the downstream extracellular signal-regulated kinase 1/2 and p38 pathways. These adverse effects of ZA were observed to be concentration-dependent. The results from the present study suggested that ZA at higher concentrations induces cytotoxicity towards osteoblasts, and ZA at lower concentrations suppresses osteoblast differentiation by downregulation of BMP-2. These results assist in further understanding the mechanisms of BRONJ. PMID:26648136

Data on the effect of geological and meteorological parameters on indoor radon and thoron level- case study: Kermanshah, Iran.

PubMed

Pirsaheb, Meghdad; Najafi, Farid; Hemati, Lida; Khosravi, Touba; Sharafi, Hooshmand

2018-06-01

The present study was aimed to evaluate the relationship between indoor radon and thoron concentrations, geological and meteorological parameters. The radon and thoron concentrations were determined in three hospitals in Kermanshah, the west part of Iran, using the RTM-1688-2 radon meter. Also, the type and porosity of the underlying soil and the meteorological parameters such as temperature, humidity, atmospheric pressure, rainfall and wind speed were studied and the obtained results analyzed using STATA-Ver.8. In this study the obtained radon concentration was furthered in buildings which constructed on the soil with clayey gravel and sand feature than the soil with clay characteristic and little pasty with a significant difference ( P < 0.05). While the lower coefficient about 1.3 was obtained in measured the thoron concentration and a significant difference was not observed. So the soil porosity can extremely effect on the indoor radon amount. Among all studied meteorological parameters, temperature has been determined as the most important meteorological parameter, influence the indoor radon and thoron concentrations.

The Politics of Staff Development.

ERIC Educational Resources Information Center

Mann, Dale

This report presents the methodology and some of the results from part of an on-going Rand Corporation study of change agent programs sponsored by the U.S. Office of Education. It concentrates on staff development as a vehicle for change in schools. After a brief introduction, the methodology of the study is presented. The third section examines…

Contaminant trends in sport fish from Lake Roosevelt and the upper Columbia River, Washington, 1994-1998

USGS Publications Warehouse

Munn, Mark D.

2000-01-01

Fish from Lake Roosevelt were first reported to contain elevated concentrations of contaminants in the early 1980?s, with mercury, dioxins and furans, and polychlorinated biphenyls (PCBs) identified as being of most concern to human health. Over the following years there were a series of studies by United States and Canadian agencies addressing contaminants in fish from both a human and environmental perspective. In the early 1990?s, industrial discharges to the Columbia River above the international boundary decreased. The dominant changes in industrial practices included a reduction in slag and effluent discharges from a lead-zinc smelter, and a reduction in dioxins and furans due to processing changes at a Canadian pulp mill. It is believed that these two alterations in industrial practices may have greatly reduced the loading of selected contaminants to the Columbia River system. In response to these recent changes, the U.S. Geological Survey initiated this present study for the purpose of determining the present concentrations of mercury, dioxins and furans, and PCBs in fish, and, if possible, to determine if concentrations have changed since the 1994 studies. All contaminant analysis was done on fish fillets in order to address human health concerns. Our study concluded that the concentrations of contaminants in fish that were identified as a potential threat to human health have either not changed since the 1994 studies, or have decreased. PCBs, as determined by Aroclor 1254, do not appear to have changed between 1994 and 1998; sources of PCBs are presently unknown. In contrast, dioxins and furans, as indicated by 2,3,7,8-TCDF, did show a significant decrease in rainbow trout fillets from 1994 to 1998. However, there was no apparent change in the average 2,3,7,8-TCDF concentrations in mountain whitefish, with the reason uncertain at this time. Average concentrations of 2,3,7,8-TCDF were higher in mountain whitefish than in rainbow trout. Toxicity equivalence concentrations (TEC) are determined by summing the relative toxicity of individual congeners of dioxins, furans, and toxic ?dioxin-like? PCB congeners in individual fish. Rainbow trout from the upper reach have higher TECs than rainbow trout from the lower reach, with trout from the upper reach having a higher percentage of the toxicity from toxic ?dioxin-like? PCBs than dioxin and furan compounds. In relation to mercury, the concentrations of total mercury in walleye have significantly decreased by about 50 percent from 1994 to 1998.

Method development estimating ambient mercury concentration from monitored mercury wet deposition

NASA Astrophysics Data System (ADS)

Chen, S. M.; Qiu, X.; Zhang, L.; Yang, F.; Blanchard, P.

2013-05-01

Speciated atmospheric mercury data have recently been monitored at multiple locations in North America; but the spatial coverage is far less than the long-established mercury wet deposition network. The present study describes a first attempt linking ambient concentration with wet deposition using Beta distribution fitting of a ratio estimate. The mean, median, mode, standard deviation, and skewness of the fitted Beta distribution parameters were generated using data collected in 2009 at 11 monitoring stations. Comparing the normalized histogram and the fitted density function, the empirical and fitted Beta distribution of the ratio shows a close fit. The estimated ambient mercury concentration was further partitioned into reactive gaseous mercury and particulate bound mercury using linear regression model developed by Amos et al. (2012). The method presented here can be used to roughly estimate mercury ambient concentration at locations and/or times where such measurement is not available but where wet deposition is monitored.

Simplified method for preparation of concentrated exoproteins produced by Staphylococcus aureus grown on surface of cellophane bag containing liquid medium.

PubMed

Ikigai, H; Seki, K; Nishihara, S; Masuda, S

1988-01-01

A simplified method for preparation of concentrated exoproteins including protein A and alpha-toxin produced by Staphylococcus aureus was successfully devised. The concentrated proteins were obtained by cultivating S. aureus organisms on the surface of a liquid medium-containing cellophane bag enclosed in a sterilized glass flask. With the same amount of medium, the total amount of proteins obtained by the method presented here was identical with that obtained by conventional liquid culture. The concentration of proteins obtained by the method, however, was high enough to observe their distinct bands stained on polyacrylamide gel electrophoresis. This method was considered quite useful not only for large-scale cultivation for the purification of staphylococcal proteins but also for small-scale study using the proteins. The precise description of the method was presented and its possible usefulness was discussed.

Effect of benzene, toluene, ethylbenzene, and p-xylene (BTEX) mixture on biodegradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) by pure culture UC1.

PubMed

Pruden, Amy; Suidan, Makram

2004-08-01

The effect of a BTEX mixture on the biodegradation of methyl tert-butyl ether (MTBE) and its degradation intermediate, tert-butyl alcohol (TBA) was investigated in the pure bacterial culture UC1, which has been identified to be a strain of the known MTBE-degrader PM1 based on greater than 99% 16S rDNA similarity. Several degradation studies were carried out on UC1 at three initial concentration levels of MTBE or TBA: 6-7; 15-17; and 40-45 mg/l, both with and without BTEX present cumulatively at about half of the MTBE or TBA molar mass in the system. The BTEX mixture was observed not to affect either the rate or the degradation lag period of MTBE or TBA degradation, except that the TBA degradation rate actually increased when BTEX was present initially in the highest concentration studies. When serving as the sole substrate, the MTBE degradation rate ranged from 48 +/- 1.2 to 200 +/- 7.0 mg(MTBE)/g(dw) h, and the TBA degradation rate from 140 +/- 18 to 530 +/- 70 mg(TBA)/g(dw) h. When present with BTEX, MTBE and TBA rates ranged from 46 +/- 2.2 to 210 +/- 14 and 170 +/- 28 to 780 +/- 43 mg(TBA)/g(dw) h, respectively. In studies where varying concentrations of TBA were present with 5 mg/l MTBE, both compounds were degraded simultaneously with no obvious preference for either substrate. In the highest concentration study of TBA with 5 mg/l MTBE, BTEX was also observed to increase the ultimate rate of TBA degradation. In addition to exploring the affect of BTEX, this study also provides general insight into the metabolism of MTBE and TBA by pure culture UC1.

Closed-form analysis of fiber-matrix interface stresses under thermo-mechanical loadings

NASA Technical Reports Server (NTRS)

Naik, Rajiv A.; Crews, John H., Jr.

1992-01-01

Closed form techniques for calculating fiber matrix (FM) interface stresses, using repeating square and diamond regular arrays, were presented for a unidirectional composite under thermo-mechanical loadings. An Airy's stress function micromechanics approach from the literature, developed for calculating overall composite moduli, was extended in the present study to compute FM interface stresses for a unidirectional graphite/epoxy (AS4/3501-6) composite under thermal, longitudinal, transverse, transverse shear, and longitudinal shear loadings. Comparison with finite element results indicate excellent agreement of the FM interface stresses for the square array. Under thermal and longitudinal loading, the square array has the same FM peak stresses as the diamond array. The square array predicted higher stress concentrations under transverse normal and longitudinal shear loadings than the diamond array. Under transverse shear loading, the square array had a higher stress concentration while the diamond array had a higher radial stress concentration. Stress concentration factors under transverse shear and longitudinal shear loadings were very sensitive to fiber volume fraction. The present analysis provides a simple way to calculate accurate FM interface stresses for both the square and diamond array configurations.

Isotopically modified nanoparticles for enhanced detection in bioaccumulation studies

USGS Publications Warehouse

Misra, S.K.; Dybowska, A.; Berhanu, D.; Croteau, M.-N.; Luoma, S.N.; Boccaccini, A.R.; Valsami-Jones, E.

2012-01-01

This work presents results on synthesis of isotopically enriched (99% 65Cu) copper oxide nanoparticles and its application in ecotoxicological studies. 65CuO nanoparticles were synthesized as spheres (7 nm) and rods (7 ?? 40 nm). Significant differences were observed between the reactivity and dissolution of spherical and rod shaped nanoparticles. The extreme sensitivity of the stable isotope tracing technique developed in this study allowed determining Cu uptake at exposure concentrations equivalent to background Cu concentrations in freshwater systems (0.2-30 ??g/L). Without a tracer, detection of newly accumulated Cu was impossible, even at exposure concentrations surpassing some of the most contaminated water systems (>1 mg/L). ?? 2011 American Chemical Society.

Quantitative measurement of tetrahydromenaquinone-9 in cheese fermented by propionibacteria.

PubMed

Hojo, K; Watanabe, R; Mori, T; Taketomo, N

2007-09-01

Propionibacteria produce tetrahydromenaquinone-9 [MK-9 (4H)] as a major menaquinone (vitamin K2). This study aimed to determine the MK-9 (4H) concentration in commercial propionibacteria-fermented cheese. The MK-9 (4H) concentration was quantified using an HPLC instrument with a fluorescence detector after postcolumn reduction. Among the various cheese samples, the MK-9 (4H) concentration was highest in Norwegian Jarlsberg cheese, followed by Swiss Emmental cheese. In contrast, the MK-9 (4H) concentrations in Appenzeller or Gruyère cheeses were extremely low or undetected. Likewise, the concentrations in Comte and Raclette cheeses were lower than those in Jarlsberg and Emmental cheeses. In the present study, the MK- 9 (4H) concentration in cheese showed a correlation with the viable propionibacterial cell count and propionate concentration. This implies that the increase in propionibacteria contributed to the generation of MK-9 (4H) in cheese. We presumed, based on these results, that Swiss Emmental and Norwegian Jarlsberg cheeses contain a meaningful amount of vitamin K because of their high MK-9 (4H) concentrations (200 to 650 ng/g).

Metabolic Characterization of the Common Marmoset (Callithrix jacchus)

PubMed Central

Go, Young-Mi; Liang, Yongliang; Uppal, Karan; Soltow, Quinlyn A.; Promislow, Daniel E. L.; Wachtman, Lynn M.; Jones, Dean P.

2015-01-01

High-resolution metabolomics has created opportunity to integrate nutrition and metabolism into genetic studies to improve understanding of the diverse radiation of primate species. At present, however, there is very little information to help guide experimental design for study of wild populations. In a previous non-targeted metabolomics study of common marmosets (Callithrix jacchus), Rhesus macaques, humans, and four non-primate mammalian species, we found that essential amino acids (AA) and other central metabolites had interspecies variation similar to intraspecies variation while non-essential AA, environmental chemicals and catabolic waste products had greater interspecies variation. The present study was designed to test whether 55 plasma metabolites, including both nutritionally essential and non-essential metabolites and catabolic products, differ in concentration in common marmosets and humans. Significant differences were present for more than half of the metabolites analyzed and included AA, vitamins and central lipid metabolites, as well as for catabolic products of AA, nucleotides, energy metabolism and heme. Three environmental chemicals were present at low nanomolar concentrations but did not differ between species. Sex and age differences in marmosets were present for AA and nucleotide metabolism and warrant additional study. Overall, the results suggest that quantitative, targeted metabolomics can provide a useful complement to non-targeted metabolomics for studies of diet and environment interactions in primate evolution. PMID:26581102

Variation of rock-forming metals in sub-annual increments of modern Greenland snow

USGS Publications Warehouse

Hinkley, T.K.

1992-01-01

Modern snowpack from central south Greenland was sampled in sub-seasonal increments and analysed for a suite of major, minor and trace rock-forming metals (K, Rb, Cs, Ca, Sr, Ba). There is a sharp seasonal concentration maximum for all six metals that comes in summer, later than mid-June. Metal concentrations in all other parts of the year's snowpack are up to 10 or more times smaller. The concentration maximum is preceded by low values in autumn-winter, very low values in early-mid-spring, and moderate-to-high values in late spring early summer; this pattern is seen consistently in three separate time stratigraphic intervals representing the same seasonal periods, spanning the time interval 1981-1984. The absolute concentration values of the snow strata representing the low-concentration portion of the year, autumn-winter-spring, may vary substantially from year to year, by a factor of two, or more. The finding that all rock-forming metals are at a sharp concentration maximum in late summer contrasts with the interpretations of several other studies in high-latitude northern regions. Those studies have reported a broad maximum of continental dust-associated metals in late winter and spring. However samples of the other studies have mostly come from regions farther to the north, and the analyses have emphasized industrial pollutant metals rather than the matched rock-forming suite of the present study. The metals measured were chosen to give information about the origin and identity of the rock and soil dusts, and sea salts, present as impurities in the snow. Metal ratios indicate that the dusts in the snowpacks are of continental origin and from ferromagnesian rocks. Source rock types for dusts in central south Greenland snow contrast with the felsic rock dusts of the Sierra Nevada, CA, annual snowpacks, and with the very felsic rock dusts in large south central Alaskan mountain glaciers. Samples in which masses of sea salt are much larger than those of rock dusts may be identified by small changes in metal ratios caused by moderate increases of K and Ca from marine sources, nearly unaccompanied by the minor and trace metals Rb, Cs and Ba, that are very rare in the oceans. A sampling frequency, such as that of the present study, that divides a year's accumulation into 8-10 subsamples is sufficient to reveal details of the time pattern of variation in proportions and concentrations of metals that give information about atmospheric deposition of important types of earth materials.Modern snowpack from central south Greenland was sampled in sub-seasonal increments and analyzed for a suite of major, minor and trace rock-forming metals (K, Rb, Cs, Ca, Sr, Ba). There is a sharp seasonal concentration maximum for all six metals that comes in summer, later than mid-June. Metal concentrations in all other parts of the year's snowpack are up to 10 or more times smaller. The concentration maximum is preceded by low values in autumn-winter, very low values in early-mid-spring, and moderate-to-high values in late spring-early summer; this pattern is seen consistently in three separate time stratigraphic intervals representing the same seasonal periods, spanning the time interval 1981-1984. The absolute concentration values of the snow strata representing the low-concentration portion of the year, autumn-winter-spring, may vary substantially from year to year, by a factor of two, or more. The finding that all rock-forming metals are at a sharp concentration maximum in late summer contrasts with the interpretations of several other studies in high-latitude northern regions. Those studies have reported a broad maximum of continental dust-associated metals in late winter and spring. However, samples of the other studies have mostly come from regions farther to the north, and the analyses have emphasized industrial pollutant metals rather than the matched rock-forming suite of the present study. The metals measured were chosen to give informati

A Study of the Effect of Color in Memory Retention When Used in Presentation Software.

ERIC Educational Resources Information Center

McConnohie, Bruce Vernon

A study of the effects of color as used in presentation software on short-range (immediately following treatment) and long-range (one hour following treatment) memory retention was conducted. Previous studies have concentrated on color as cueing or coding mechanisms primarily in print media and have not explored the effect of individual colors as…

Biological variables and health status affecting inorganic element concentrations in harbour porpoises (Phocoena phocoena) from Portugal (western Iberian Peninsula).

PubMed

Ferreira, Marisa; Monteiro, Silvia S; Torres, Jordi; Oliveira, Isabel; Sequeira, Marina; López, Alfredo; Vingada, José; Eira, Catarina

2016-03-01

The coastal preferences of harbour porpoise (Phocoena phocoena) intensify their exposure to human activities. The harbour porpoise Iberian population is presently very small and information about the threats it endures is vital for the conservation efforts that are being implemented to avoid local extinction. The present study explored the possible relation between the accumulation of trace elements by porpoises and their sex, body length, nutritional state, presence of parasites and gross pathologies. The concentrations of arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), zinc (Zn) and selenium (Se) were evaluated in 42 porpoises stranded in Portugal between 2005 and 2013. Considering European waters, porpoises stranded in Portugal present the highest Hg concentrations and the lowest Cd concentrations, which may reflect dietary preferences and the geographic availability of these pollutants. While no effect of sex on trace element concentrations was detected, there was a positive relationship between porpoise body length and the concentration of Cd, Hg and Pb. Animals in worse nutritional condition showed higher levels of Zn. Harbour porpoises with high parasite burdens showed lower levels of Zn and As in all analysed tissues and also lower levels of renal Ni, while those showing gross pathologies presented higher Zn and Hg levels. This is the first data on the relationship between trace elements and health-related variables in porpoises from southern European Atlantic waters, providing valuable baseline information about the contamination status of this vulnerable population. Copyright © 2016 Elsevier Ltd. All rights reserved.

Design of a Modular E-Core Flux Concentrating Axial Flux Machine

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

Husain, Tausif; Sozer, Yilmaz; Husain, Iqbal

2015-09-02

In this paper a novel E-Core axial flux machine is proposed. The machine has a double stator-single rotor configuration with flux concentrating ferrite magnets, and pole windings across each leg of an E-Core stator. E-Core stators with the proposed flux-concentrating rotor arrangement result in better magnet utilization and higher torque density. The machine also has a modular structure facilitating simpler construction. This paper presents a single phase and a three-phase version of the E-Core machine. Case study for a 1.1 kW, 400 rpm machine for both the single phase and three-phase axial flux machine is presented. The results are verifiedmore » through 3D finite element analysis.« less

Global statistics of liquid water content and effective number concentration of water clouds over ocean derived from combined CALIPSO and MODIS measurements

NASA Astrophysics Data System (ADS)

Hu, Y.; Vaughan, M.; McClain, C.; Behrenfeld, M.; Maring, H.; Anderson, D.; Sun-Mack, S.; Flittner, D.; Huang, J.; Wielicki, B.; Minnis, P.; Weimer, C.; Trepte, C.; Kuehn, R.

2007-06-01

This study presents an empirical relation that links the volume extinction coefficients of water clouds, the layer integrated depolarization ratios measured by lidar, and the effective radii of water clouds derived from collocated passive sensor observations. Based on Monte Carlo simulations of CALIPSO lidar observations, this method combines the cloud effective radius reported by MODIS with the lidar depolarization ratios measured by CALIPSO to estimate both the liquid water content and the effective number concentration of water clouds. The method is applied to collocated CALIPSO and MODIS measurements obtained during July and October of 2006, and January 2007. Global statistics of the cloud liquid water content and effective number concentration are presented.

Assessment of impact of unaccounted emission on ambient concentration using DEHM and AERMOD in combination with WRF

NASA Astrophysics Data System (ADS)

Kumar, Awkash; Patil, Rashmi S.; Dikshit, Anil Kumar; Kumar, Rakesh; Brandt, Jørgen; Hertel, Ole

2016-10-01

The accuracy of the results from an air quality model is governed by the quality of emission and meteorological data inputs in most of the cases. In the present study, two air quality models were applied for inverse modelling to determine the particulate matter emission strengths of urban and regional sources in and around Mumbai in India. The study takes outset in an existing emission inventory for Total Suspended Particulate Matter (TSPM). Since it is known that the available TSPM inventory is uncertain and incomplete, this study will aim for qualifying this inventory through an inverse modelling exercise. For use as input to the air quality models in this study, onsite meteorological data has been generated using the Weather Research Forecasting (WRF) model. The regional background concentration from regional sources is transported in the atmosphere from outside of the study domain. The regional background concentrations of particulate matter were obtained from model calculations with the Danish Eulerian Hemisphere Model (DEHM) for regional sources. The regional background concentrations obtained from DEHM were then used as boundary concentrations in AERMOD calculations of the contribution from local urban sources. The results from the AERMOD calculations were subsequently compared with observed concentrations and emission correction factors obtained by best fit of the model results to the observed concentrations. The study showed that emissions had to be up-scaled by between 14 and 55% in order to fit the observed concentrations; this is of course when assuming that the DEHM model describes the background concentration level of the right magnitude.

Optimal Reflectance, Transmittance, and Absorptance Wavebands and Band Ratios for the Estimation of Leaf Chlorophyll Concentration

NASA Technical Reports Server (NTRS)

Carter, Gregory A.; Spiering, Bruce A.

2000-01-01

The present study utilized regression analysis to identify: wavebands and band ratios within the 400-850 nm range that could be used to estimate total chlorophyll concentration with minimal error; and simple regression models that were most effective in estimating chlorophyll concentrations were measured for two broadleaved species, a broadleaved vine, a needle-leaved conifer, and a representative of the grass family.Overall, reflectance, transmittance, and absorptance corresponded most precisely with chlorophyll concentration at wavelengths near 700 nm, although regressions were strong as well in the 550-625 nm range.

Antagonistic activity of Ocimum sanctum L. essential oil on growth and zearalenone production by Fusarium graminearum in maize grains.

PubMed

Kalagatur, Naveen K; Mudili, Venkataramana; Siddaiah, Chandranayaka; Gupta, Vijai K; Natarajan, Gopalan; Sreepathi, Murali H; Vardhan, Batra H; Putcha, Venkata L R

2015-01-01

The present study was aimed to establish the antagonistic effects of Ocimum sanctum L. essential oil (OSEO) on growth and zearalenone (ZEA) production of Fusarium graminearum. GC-MS chemical profiling of OSEO revealed the existence of 43 compounds and the major compound was found to be eugenol (34.7%). DPPH free radical scavenging activity (IC50) of OSEO was determined to be 8.5 μg/mL. Minimum inhibitory concentration and minimum fungicidal concentration of OSEO on F. graminearum were recorded as 1250 and 1800 μg/mL, respectively. Scanning electron microscope observations showed significant micro morphological damage in OSEO exposed mycelia and spores compared to untreated control culture. Quantitative UHPLC studies revealed that OSEO negatively effected the production of ZEA; the concentration of toxin production was observed to be insignificant at 1500 μg/mL concentration of OSEO. On other hand ZEA concentration was quantified as 3.23 μg/mL in OSEO untreated control culture. Reverse transcriptase qPCR analysis of ZEA metabolic pathway genes (PKS4 and PKS13) revealed that increase in OSEO concentration (250-1500 μg/mL) significantly downregulated the expression of PKS4 and PKS13. These results were in agreement with the artificially contaminated maize grains as well. In conlusion, the antifungal and antimycotoxic effects of OSEO on F. graminearum in the present study reiterated that, the essential oil of O. sanctum could be a promising herbal fungicide in food processing industries as well as grain storage centers.

Antagonistic activity of Ocimum sanctum L. essential oil on growth and zearalenone production by Fusarium graminearum in maize grains

PubMed Central

Kalagatur, Naveen K.; Mudili, Venkataramana; Siddaiah, Chandranayaka; Gupta, Vijai K.; Natarajan, Gopalan; Sreepathi, Murali H.; Vardhan, Batra H.; Putcha, Venkata L. R.

2015-01-01

The present study was aimed to establish the antagonistic effects of Ocimum sanctum L. essential oil (OSEO) on growth and zearalenone (ZEA) production of Fusarium graminearum. GC–MS chemical profiling of OSEO revealed the existence of 43 compounds and the major compound was found to be eugenol (34.7%). DPPH free radical scavenging activity (IC50) of OSEO was determined to be 8.5 μg/mL. Minimum inhibitory concentration and minimum fungicidal concentration of OSEO on F. graminearum were recorded as 1250 and 1800 μg/mL, respectively. Scanning electron microscope observations showed significant micro morphological damage in OSEO exposed mycelia and spores compared to untreated control culture. Quantitative UHPLC studies revealed that OSEO negatively effected the production of ZEA; the concentration of toxin production was observed to be insignificant at 1500 μg/mL concentration of OSEO. On other hand ZEA concentration was quantified as 3.23 μg/mL in OSEO untreated control culture. Reverse transcriptase qPCR analysis of ZEA metabolic pathway genes (PKS4 and PKS13) revealed that increase in OSEO concentration (250–1500 μg/mL) significantly downregulated the expression of PKS4 and PKS13. These results were in agreement with the artificially contaminated maize grains as well. In conlusion, the antifungal and antimycotoxic effects of OSEO on F. graminearum in the present study reiterated that, the essential oil of O. sanctum could be a promising herbal fungicide in food processing industries as well as grain storage centers. PMID:26388846

Reductions in indoor black carbon concentrations from improved biomass stoves in rural India.

PubMed

Patange, Omkar S; Ramanathan, Nithya; Rehman, I H; Tripathi, Sachi Nand; Misra, Amit; Kar, Abhishek; Graham, Eric; Singh, Lokendra; Bahadur, Ranjit; Ramanathan, V

2015-04-07

Deployment of improved biomass burning cookstoves is recognized as a black carbon (BC) mitigation measure that has the potential to achieve health benefits and climate cobenefits. Yet, few field based studies document BC concentration reductions (and resulting human exposure) resulting from improved stove usage. In this paper, data are presented from 277 real-world cooking sessions collected during two field studies to document the impacts on indoor BC concentrations inside village kitchens as a result of switching from traditional stoves to improved forced draft (FD) stoves. Data collection utilized new low-cost cellphone methods to monitor BC, cooking duration, and fuel consumption. A cross sectional study recorded a reduction of 36% in BC during cooking sessions. An independent paired sample study demonstrated a statistically significant reduction of 40% in 24 h BC concentrations when traditional stoves were replaced with FD stoves. Reductions observed in these field studies differ from emission factor reductions (up to 99%) observed under controlled conditions in laboratory studies. Other nonstove sources (e.g., kerosene lamps, ambient concentrations) likely offset the reductions. Health exposure studies should utilize reductions determined by field measurements inside village kitchens, in conjunction with laboratory data, to assess the health impacts of new cooking technologies.

Determination of ochratoxin A in tissues of wild boar (Sus scrofa L.) by enzymatic digestion (ED) coupled to high-performance liquid chromatography with a fluorescence detector (HPLC-FLD).

PubMed

Luci, Giacomo; Intorre, Luigi; Ferruzzi, Guido; Mani, Danilo; Giuliotti, Lorella; Pretti, Carlo; Tognetti, Rosalba; Bertini, Simone; Meucci, Valentina

2018-03-01

Ochratoxin A (OTA) is a secondary toxic metabolite synthesized by Aspergillus or Penicillium species, which can contaminate various crops. The International Agency for Research on Cancer (IARC) classified OTA as a group 2B possible human carcinogen. The aim of the present study was to assess OTA concentrations in tissues of wild boar (Sus scrofa L.) from Tuscany (Italy). Over a period of 2 years, samples of muscle, liver, and kidney from 48 wild boars were collected and concentrations of OTA were determined by enzymatic digestion (ED) coupled to high-performance liquid chromatography with a fluorescence detector (HPLC-FLD). The highest concentrations of OTA were found in the kidneys of the 48 wild boars analyzed. No difference in concentrations was found based on years of collection and sex while a significantly higher OTA concentration was found in the kidney of the young wild boars with respect to the adult one. Monitoring the quality of meat destined for transformation is a priority in order to decrease the possibility of toxin carry-over to humans. The present study showed that contamination of wild boar meat products by OTA represents a potential emerging source of OTA.

Cadmium removal by Lemna minor and Spirodela polyrhiza.

PubMed

Chaudhuri, Devaleena; Majumder, Arunabha; Misra, Amal K; Bandyopadhyay, Kaushik

2014-01-01

The present study investigates the ability of two genus of duckweed (Lemna minor and Spirodela polyrhiza) to phytoremediate cadmium from aqueous solution. Duckweed was exposed to six different cadmium concentrations, such as, 0.5,1.0,1.5, 2.0, 2.5, and 3.0 mg/L and the experiment was continued for 22 days. Water samples were collected periodically for estimation of residual cadmium content in aqueous solution. At the end of treatment period plant samples were collected and accumulated cadmium content was measured. Cadmium toxicity was observed through relative growth factor and changes in chlorophyll content Experimental results showed that Lemna minor and Spirodela polyrhiza were capable of removing 42-78% and 52-75% cadmium from media depending upon initial cadmium concentrations. Cadmium was removed following pseudo second order kinetic model Maximum cadmium accumulation in Lemna minor was 4734.56 mg/kg at 2 mg/L initial cadmium concentration and 7711.00 mg/kg in Spirodela polyrhiza at 3 mg/L initial cadmium concentration at the end of treatment period. Conversely in both cases maximum bioconcentration factor obtained at lowest initial cadmium concentrations, i.e., 0.5 mg/L, were 3295.61 and 4752.00 for Lemna minor and Spirodela polyrhiza respectively. The present study revealed that both Lemna minor and Spirodela polyrhiza was potential cadmium accumulator.

Single and multidose ocular kinetics and stability analysis of extemporaneous formulation of topical voriconazole in humans.

PubMed

Senthilkumari, Srinivasan; Lalitha, Prajna; Prajna, Namperumalsamy Venkatesh; Haripriya, Aravind; Nirmal, Jeyabalan; Gupta, Pankaj; Velpandian, Thirumurthy

2010-11-01

The purpose of the present study was to evaluate the kinetics of single and multiple doses of topical, non-preserved voriconazole (VZ) in human eyes. For single dose kinetics, 119 patients undergoing cataract surgery were divided into group I and group II and each group received a single drop (30 µl) of either 1% or 0.1% VZ formulation. Aqueous humor was collected at designated time intervals. For multidose kinetics, a single drop of 1% VZ was instilled 5 times either hourly or every 2 hr. The aqueous humor was tested for VZ at the 5th hr and 9th hr, respectively, after initial instillation. The stability and efficacy of the reconstituted VZ formulations were also evaluated after 30 days. Single dose ocular kinetics of 1% VZ resulted in a maximum mean aqueous concentration of 3.333 ± 1.61 µg/ml in 30 min whereas 0.1% showed a maximum mean aqueous concentration of 0.817 ±.36 µg/ml. In the multidose kinetic study, hourly and bi-hourly dosing resulted in mean aqueous concentrations of 7.47 ± 2.14 µg/ml and 4.69 ± 2.7 µg/ml, respectively. The reconstituted VZ formulations were stable at all studied temperatures, and their efficacy was maintained throughout the study period. The present study showed that the achieved mean concentration of VZ in both single dose and multi dose kinetic studies satisfactorily met the MIC(90) for almost all causative fungal organisms. The frequency of instillation may be designed for an "every 2 hr regimen" to maintain a therapeutic concentration for successful therapy.

Effect of bicarbonate concentration on aerobic growth of campylobacter in a fumarate-pyruvate medium

USDA-ARS?s Scientific Manuscript database

The purpose of the present study was to examine the effect of sodium bicarbonate (NaHCO3) concentration on aerobic growth of Campylobacter in a fumarate-pyruvate medium. Fumarate-pyruvate broth medium was supplemented with 0.00 to 0.10% NaHCO3 and inoculated with Campylobacter coli 33559, Campyloba...

Transport Phenomena Projects: Natural Convection between Porous, Concentric Cylinders--A Method to Learn and to Innovate

ERIC Educational Resources Information Center

Saatadjian, Esteban; Lesage, Francois; Mota, Jose Paulo B.

2013-01-01

A project that involves the numerical simulation of transport phenomena is an excellent method to teach this subject to senior/graduate chemical engineering students. The subject presented here has been used in our senior/graduate course, it concerns the study of natural convection heat transfer between two concentric, horizontal, saturated porous…

A study of alternative designs for a system to concentrate carbon dioxide in a hydrogen-depolarized cell

NASA Technical Reports Server (NTRS)

1973-01-01

Experimental results are presented on alternative designs for a hydrogen depolarized cell to concentrate CO2 in spacecraft atmospheric control systems. Data cover technical problems, methods for solving these problems, and the suitability of such a cell for CO2 removal and control of atmospheric humidity during the flight mode.

DEPOSITION AND EMISSION OF GASEOUS MERCURY TO AND FROM LAKE MICHIGAN DURING THE LAKE MICHIGAN MASS BALANCE STUDY (JULY, 1994 - OCTOBER, 1995)

EPA Science Inventory

This paper presents measurements of dissolved gaseous mercury (DGM) concentrations in Lake Michigan and the application of a mechanistic approach to estimate deposition and emission fluxes of gaseous mercury (Hg2+ and Hg0) to and from Lake Michigan. Measurements of DGM concentr...

Mapping the Life Satisfaction of Adolescents in Hong Kong Secondary Schools with High Ethnic Concentration

ERIC Educational Resources Information Center

Yuen, Yuet Mui Celeste; Lee, Moosung

2016-01-01

The present study aims to map the life satisfaction of adolescents from ethnic minority/immigrant backgrounds in schools with high concentrations of co-ethnic peers by comparing them with their mainstream counterparts in Hong Kong. The life satisfaction of 1,522 students was measured by the validated Multidimensional Students' Life Satisfaction…

Metabolic and hormonal responses of growing modern meat type chickens to fasting

USDA-ARS?s Scientific Manuscript database

The present study compared the effects of fasting on circulating concentrations of glucose, insulin and glucagon in male and female modern meat-type chickens (Ross 708) at three ages (19 d, 33 d and 47 d). Plasma concentrations of glucose were reduced by fasting with reductions of 24.9% (19-d-old),...

The study of barium concentration in deciduous teeth, impacted teeth, and facial bones of Polish residents.

PubMed

Fischer, Agnieszka; Malara, Piotr; Wiechuła, Danuta

2014-10-01

The study determines the concentration of Ba in mineralized tissues of deciduous teeth, permanent impacted teeth, and facial bones. The study covers the population of children and adults (aged 6-78) living in an industrial area of Poland. Teeth were analyzed in whole, with no division into dentine and enamel. Facial bones and teeth were subjected to the following preparation: washing, drying, grinding in a porcelain mortar, sample weighing (about 0.2 g), and microwave mineralization with spectrally pure nitric acid. The aim of the study was to determinate the concentration of Ba in deciduous teeth, impacted permanent teeth, and facial bones. The concentration of barium in samples was determined over the ICP OES method. The Ba concentration in the tested bone tissues amounted to 2.2-15.5 μg/g (6.6 μg/g ± 3.9). The highest concentration of Ba was present in deciduous teeth (10.5 μg/g), followed by facial bones (5.2 μg/g), and impacted teeth (4.3 μg/g) (ANOVA Kruskal-Wallis rank test, p = 0.0002). In bone tissue and impacted teeth, Ba concentration increased with age. In deciduous teeth, the level of Ba decreased with children's age.

Novel Apparatus for the Real-Time Quantification of Dissolved Gas Concentrations and Isotope Ratios

NASA Astrophysics Data System (ADS)

Gupta, M.; Leen, J.; Baer, D. S.; Owano, T. G.; Liem, J.

2013-12-01

Measurements of dissolved gases and their isotopic composition are critical in studying a variety of phenomena, including underwater greenhouse gas generation, air-surface exchange, and pollution migration. These studies typically involve obtaining water samples from streams, lakes, or ocean water and transporting them to a laboratory, where they are degased. The gases obtained are then generally measured using gas chromatography and isotope ratio mass spectrometry for concentrations and isotope ratios, respectively. This conventional, off-line methodology is time consuming, significantly limits the number of the samples that can be measured and thus severely inhibits detailed spatial and temporal mapping of gas concentrations and isotope ratios. In this work, we describe the development of a new membrane-based degassing device that interfaces directly to Los Gatos Research (cavity enhanced laser absorption or Off-Axis ICOS) gas analyzers (cavity enhanced laser absorption or Off-Axis ICOS analyzers) to create an autonomous system that can continuously and quickly measure concentrations and isotope ratios of dissolved gases in real time in the field. By accurately controlling the water flow rate through the membrane degasser, gas pressure on the outside of the membrane, and water pressure on the inside of the membrane, the system is able to generate precise and highly reproducible results. Moreover, by accurately measuring the gas flow rates in and out of the degasser, the gas-phase concentrations (ppm) could be converted into dissolved gas concentrations (nM). We will present detailed laboratory test data that quantifies the linearity, precision, and dynamic range of the system for the concentrations and isotope ratios of dissolved methane, carbon dioxide, and nitrous oxide. By interfacing the degassing device to a novel cavity-enhanced spectrometer (developed by LGR), preliminary data will also be presented for dissolved volatile organics (VOC) and other pollutants. Finally, the system was deployed shipboard, and field deployment data will also be presented.

The systems impact of a concentrated solar array on a Jupiter orbiter

NASA Technical Reports Server (NTRS)

Rockey, D. E.; Bamford, R.; Hollars, M. G.; Klemetson, R. W.; Koerner, T. W.; Marsh, E. L.; Price, H.; Uphoff, C.

1981-01-01

Results of a study are presented suggesting that a Galileo Jupiter orbiting mission could be performed with a concentrated solar array power source. A baseline spacecraft design using concentrated arrays is given, and the overall spacecraft implications for attitude control, propulsion, power conditioning and the resultant spacecraft mass are examined. It is noted that while the concentrated array concept still requires extensive development effort, no insurmountable system level barriers preclude the use of a concentrated solar array on this difficult mission, with its stressing radiation environment, its lengthy periods of spacecraft shadowing as it passes behind Jupiter, and, finally, its large delta v burn required for orbital insertion.

Brief reports: plasma ropivacaine concentrations after ultrasound-guided rectus sheath block in patients undergoing lower abdominal surgery.

PubMed

Wada, Morito; Kitayama, Masato; Hashimoto, Hiroshi; Kudo, Tsuyoshi; Kudo, Mihoko; Takada, Norikazu; Hirota, Kazuyoshi

2012-01-01

A rectus sheath block can provide postoperative analgesia for midline incisions. However, information regarding the pharmacokinetics of local anesthetics used in this block is lacking. In this study, we detail the time course of ropivacaine concentrations after this block. Thirty-nine patients undergoing elective lower abdominal surgery were assigned to 3 groups receiving rectus sheath block with 20 mL of different concentrations of ropivacaine. Peak plasma concentrations were dose dependent, and there were no significant differences in the times to peak plasma concentrations. The present data also suggested a slower absorption kinetics profile for ropivacaine after rectus sheath block than other compartment blocks.

A Survey of Naturally-Occurring Steroid Hormones in Raw Milk and the Associated Health Risks in Tangshan City, Hebei Province, China

PubMed Central

Qu, Xueyin; Su, Chuanyou; Zheng, Nan; Li, Songli; Meng, Lu; Wang, Jiaqi

2017-01-01

In recent years, high levels of hormone residue in food, capable of damaging the health of consumers, have been recorded frequently. In this study, 195 raw milk samples were obtained from Tangshan City, China, and the concentrations of 22 steroid hormones were measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Cortisol was detected in 12.5% of raw milk samples (mean 0.61 µg/kg; range:

Influence of chemical speciation and biofilm composition on mercury accumulation by freshwater biofilms.

PubMed

Dranguet, P; Le Faucheur, S; Cosio, C; Slaveykova, V I

2017-01-25

Mercury (Hg) is a pollutant of high concern for aquatic systems due to the biomagnification of its methylated form along the food chain. However, in contrast to other metals, gaining knowledge of its bioavailable forms for aquatic microorganisms remains challenging, making Hg risk assessment difficult. Ubiquitous and sessile freshwater biofilms are well known to accumulate and to transform Hg present in their ambient environment. The present study thus aims to evaluate whether non-extractable (proxy of intracellular) Hg accumulated by biofilms could be a good indicator of Hg bioavailability for microorganisms in freshwater. To that end, the link between Hg concentration and speciation, as well as biofilm composition (percentage of abiotic, biotic, chlorophyll and phycocyanin-fractions and abundance of dsrA, gcs, merA and hgcA bacterial genes) and biofilm Hg accumulation was examined. The studied biofilms were grown on artificial substrata in four reservoirs along the Olt River (Romania), which was contaminated by Hg coming from chlor-alkali plant effluents. The 0.45 μm-filterable Hg concentrations in ambient waters were measured and inorganic IHg speciation was modelled. Biofilms were analyzed for their non-extractable IHg and methylmercury (MeHg) contents as well as for their composition. The non-extractable IHg content was related, but not significantly, to the concentration of total IHg (r 2 = 0.88, p = 0.061) whereas a significant correlation was found with the predicted IHg concentration that is not bound to dissolved organic matter (r 2 = 0.95, p = 0.027), despite its extremely low concentrations (10 -25 M), showing a limitation of the thermodynamic Hg modelling to predict Hg bioavailability. The studied biofilms were different in biomass and composition and a principal component analysis showed that the non-extractable IHg content correlated with the abundance of the merA and hgcA genes, while MeHg accumulation was only linked with the abundance of the rRNA 16S gene. The present study suggests that non-extractable IHg concentrations in biofilms are a useful proxy of IHg bioavailable forms in waters whereas the hgcA and merA genes are good biomarkers of both biofilm IHg exposure and bioavailability.

Forced swimming and imipramine modify plasma and brain amino acid concentrations in mice.

PubMed

Murakami, Tatsuro; Yamane, Haruka; Tomonaga, Shozo; Furuse, Mitsuhiro

2009-01-05

The relationships between monoamine metabolism and forced swimming or antidepressants have been well studied, however information is lacking regarding amino acid metabolism under these conditions. Therefore, the aim of the present study was to investigate the effects of forced swimming and imipramine on amino acid concentrations in plasma, the cerebral cortex and the hypothalamus in mice. Forced swimming caused cerebral cortex concentrations of L-glutamine, L-alanine, and taurine to be increased, while imipramine treatment caused decreased concentrations of L-glutamate, L-alanine, L-tyrosine, L-methionine, and L-ornithine. In the hypothalamus, forced swimming decreased the concentration of L-serine while imipramine treatment caused increased concentration of beta-alanine. Forced swimming caused increased plasma concentration of taurine, while concentrations of L-serine, L-asparagine, L-glutamine and beta-alanine were decreased. Imipramine treatment caused increased plasma concentration of all amino acid, except for L-aspartate and taurine. In conclusion, forced swimming and imipramine treatment modify central and peripheral amino acid metabolism. These results may aid in the identification of amino acids that have antidepressant-like effects, or may help to refine the dosages of antidepressant drugs.

Chloramination of Concentrated Drinking Water for ...

EPA Pesticide Factsheets

Abstract for presentation on chloraminated drinking water concentrates to create whole DBP mixtures Abstract for presentation on chloraminating drinking water concentrates to create whole DBP mixtures

Iron concentration, bioavailability, and nutritional quality of polished rice affected by different forms of foliar iron fertilizer.

PubMed

He, Wanling; Shohag, M J I; Wei, Yanyan; Feng, Ying; Yang, Xiaoe

2013-12-15

The present study compared the effects of four different forms of foliar iron (Fe) fertilizers on Fe concentration, bioavailability and nutritional quality of polished rice. The results showed that foliar fertilisation at the anthesis stage was an effective way to promote Fe concentration and bioavailability of polished rice, especially in case of DTPA-Fe. Compared to the control, foliar application of DTPA-Fe increased sulphur concentration and the nutrition promoter cysteine content, whereas decreased phosphorus concentration and the antinutrient phytic acid content of polished rice, as a result increased 67.2% ferrtin formation in Caco-2 cell. Moreover, foliar DTPA-Fe application could maintain amylase, protein and minerals quality of polished rice. According to the current study, DTPA-Fe is recommended as an excellent foliar Fe form for Fe biofortification program. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of variation in indium concentration on the photosensitivity of chlorine doped In{sub 2}S{sub 3} thin films

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

Cherian, Angel Susan; Kartha, C. Sudha; Vijayakumar, K. P.

2014-01-28

Consequence of variation in Indium concentration in chlorine doped In2S{sub 3} thin films deposited by spray pyrolysis technique was studied. Chlorine was incorporated in the spray solution, using HCl and Indium concentration was varied by adjusting In/S ratio Interestingly, the photo response of all chlorine doped samples augmented compared to pristine samples; but the highest photosensitivity value of ∼2300 was obtained only when 36ml 0.5M HCl was added to the solution of In{sub 2}S{sub 3} having In/S=2/8. It was also observed that samples with high photosensitivity possess higher band gap and variation in sub band gap absoption levels were observedmore » with increase in Indium concentration. The present study proved that concentration of Indium plays an important role in controlling the crystallinity and photosensitivity of chlorine doped samples.« less

Mercury in soils of the agro-industrial zone of Zima city (Irkutsk oblast)

NASA Astrophysics Data System (ADS)

Butakov, E. V.; Kuznetsov, P. V.; Kholodova, M. S.; Grebenshchikova, V. I.

2017-11-01

Data on mercury concentrations in soils of the agro-industrial zone of Zima city in Irkutsk oblast are discussed. It is shown that mercury concentrations in the plow horizon of studied soils exceed background values. The distribution pattern of mercury in soils of the investigated area is characterized. The revealed mercury anomalies are allocated to the industrial zone of the Sayanskkhimprom plant. The combined analysis of data on mercury concentrations in the plow and subplow horizons and on the chemical composition of snow indicates that mercury enters the soil mainly with atmospheric precipitation and is present there in the adsorbed form. The correlation analysis indicates that the local thermal power station plays a significant role as the source of mercury emission to the atmosphere. Close relationships between mercury concentrations and concentrations of mobile forms of elements attest to the presence of mobile organomineral mercury compounds in the studied soils.

Toxicity of glyphosate as Glypro and LI700 to red-eared slider (trachemys scripta elegans) embryos and early hatchlings.

PubMed

Sparling, Donald W; Matson, Cole; Bickham, John; Doelling-Brown, Paige

2006-10-01

More than 8.2 billion ha of cropland, gardens, and forests are treated with the herbicide glyphosate each year. Whereas the toxicity of glyphosate and associated adjuvants has been measured in other vertebrates, few, if any, studies have looked at their effects in reptiles. In some instances, management of turtle habitat requires control of successional stages through application of herbicides. Adults and juvenile turtles may be exposed directly, whereas embryos may contact the chemicals through the soil. In the present study, we exposed eggs of red-eared sliders (Trachemys scripta elegans) to single applications of herbicide ranging from 0 to 11,206 ppm wet weight of glyphosate in Glypro and 0 to 678 ppm of the surfactant, LI700. Hatching success at the highest concentration was significantly lower (73%) than in other treatments (80-100%). At hatch, turtles at the highest concentration weighed less than those at other concentrations. During a 14-d holding period, we observed dose-response relationships in the ability of hatchlings to right themselves when turned on their backs. At the end of the holding period, hatchlings at the highest dose level were still lighter, and somatic indices were lower, than those in other treatments. Genetic damage, as measured by flow cytometry, increased with treatment concentration except for the highest dose. We conclude that because of the high concentrations needed to produce effects and the protection offered by several centimeters of soil or sediment, glyphosate with LI700 poses low levels of risk to red-eared slider embryos under normal field operations with regards to the endpoints measured in the present study. Carelessness in handling glyphosate or failure to follow label directions may produce adverse effects. There also is a risk that the health of turtle embryos may be affected in ways not measured in the present study.

Study on rheological properties of CMC/Eu-Tb solutions with different concentrations

NASA Astrophysics Data System (ADS)

Fu, Z. C.; Ye, J.; Xiong, J.

2018-05-01

The rheological properties of polymer solution are sensitive to variations in the polymer structure. Carboxymethyl cellulose (CMC) aqueous solution has been used in many fields, such as food, medicine and paper industry. In this paper, the effects of different concentrations (2% - 6%) of CMC/Eu-Tb on their rheological properties were investigeted, including steady-state flow and viscoelastic response. The results show that, the viscosity of CMC/Eu-Tb is lower than that of CMC, at the same concentrations; the products solutions present a nearly Newtonian behavior at the low concentrations (2% - 3%); while at the higher concentrations (4% - 6%), the products solutions present a pseudoplastic behavior; shear-thinning behavior is due to the polymer chains unravel under the action of flow and the molecular chains are oriented in the flow direction. The results also show that the viscosity of the solutions decreases with increasing temperature. Dynamic rheological tests show that CMC/Eu-Tb has viscoelasticity in the concentrations of 2% - 6%. At lower concentrations, the elastic modulus G‧ is slightly higher than the viscous modulus G″, and as the concentrations increase, the elastic modulus G‧ is significantly higher than the viscous modulus G″. It means that at the lower solution concentrations, the solutions tend to be less elastic and easier to flow. Most of the energies are lost through the viscous flow. As the solution concentrations increase, the solutions tend to be more elastic, and the system tends to form a gel.

Controls on selenium distribution and mobilization in an irrigated shallow groundwater system underlain by Mancos Shale, Uncompahgre River Basin, Colorado, USA

USGS Publications Warehouse

Mills, Taylor J.; Mast, M. Alisa; Thomas, Judith C.; Keith, Gabrielle L.

2016-01-01

Elevated selenium (Se) concentrations in surface water and groundwater have become a concern in areas of the Western United States due to the deleterious effects of Se on aquatic ecosystems. Elevated Se concentrations are most prevalent in irrigated alluvial valleys underlain by Se-bearing marine shales where Se can be leached from geologic materials into the shallow groundwater and surface water systems. This study presents groundwater chemistry and solid-phase geochemical data from the Uncompahgre River Basin in Western Colorado, an irrigated alluvial landscape underlain by Se-rich Cretaceous marine shale. We analyzed Se species, major and trace elements, and stable nitrogen and oxygen isotopes of nitrate in groundwater and aquifer sediments to examine processes governing selenium release and transport in the shallow groundwater system. Groundwater Se concentrations ranged from below detection limit (< 0.5 μg L− 1) to 4070 μg L− 1, and primarily are controlled by high groundwater nitrate concentrations that maintain oxidizing conditions in the aquifer despite low dissolved oxygen concentrations. High nitrate concentrations in non-irrigated soils and nitrate isotopes indicate nitrate is largely derived from natural sources in the Mancos Shale and alluvial material. Thus, in contrast to areas that receive substantial NO3 inputs through inorganic fertilizer application, Se mitigation efforts that involve limiting NO3 application might have little impact on groundwater Se concentrations in the study area. Soluble salts are the primary source of Se to the groundwater system in the study area at-present, but they constitute a small percentage of the total Se content of core material. Sequential extraction results indicate insoluble Se is likely composed of reduced Se in recalcitrant organic matter or discrete selenide phases. Oxidation of reduced Se species that constitute the majority of the Se pool in the study area could be a potential source of Se in the future as soluble salts are progressively depleted.

Controls on selenium distribution and mobilization in an irrigated shallow groundwater system underlain by Mancos Shale, Uncompahgre River Basin, Colorado, USA.

PubMed

Mills, Taylor J; Mast, M Alisa; Thomas, Judith; Keith, Gabrielle

2016-10-01

Elevated selenium (Se) concentrations in surface water and groundwater have become a concern in areas of the Western United States due to the deleterious effects of Se on aquatic ecosystems. Elevated Se concentrations are most prevalent in irrigated alluvial valleys underlain by Se-bearing marine shales where Se can be leached from geologic materials into the shallow groundwater and surface water systems. This study presents groundwater chemistry and solid-phase geochemical data from the Uncompahgre River Basin in Western Colorado, an irrigated alluvial landscape underlain by Se-rich Cretaceous marine shale. We analyzed Se species, major and trace elements, and stable nitrogen and oxygen isotopes of nitrate in groundwater and aquifer sediments to examine processes governing selenium release and transport in the shallow groundwater system. Groundwater Se concentrations ranged from below detection limit (<0.5μgL(-1)) to 4070μgL(-1), and primarily are controlled by high groundwater nitrate concentrations that maintain oxidizing conditions in the aquifer despite low dissolved oxygen concentrations. High nitrate concentrations in non-irrigated soils and nitrate isotopes indicate nitrate is largely derived from natural sources in the Mancos Shale and alluvial material. Thus, in contrast to areas that receive substantial NO3 inputs through inorganic fertilizer application, Se mitigation efforts that involve limiting NO3 application might have little impact on groundwater Se concentrations in the study area. Soluble salts are the primary source of Se to the groundwater system in the study area at-present, but they constitute a small percentage of the total Se content of core material. Sequential extraction results indicate insoluble Se is likely composed of reduced Se in recalcitrant organic matter or discrete selenide phases. Oxidation of reduced Se species that constitute the majority of the Se pool in the study area could be a potential source of Se in the future as soluble salts are progressively depleted. Published by Elsevier B.V.

Human biomonitoring pilot study DEMOCOPHES in Germany: Contribution to a harmonized European approach.

PubMed

Schwedler, Gerda; Seiwert, Margarete; Fiddicke, Ulrike; Ißleb, Sissy; Hölzer, Jürgen; Nendza, Julia; Wilhelm, Michael; Wittsiepe, Jürgen; Koch, Holger M; Schindler, Birgit K; Göen, Thomas; Hildebrand, Jörg; Joas, Reinhard; Joas, Anke; Casteleyn, Ludwine; Angerer, Jürgen; Castano, Argelia; Esteban, Marta; Schoeters, Greet; Den Hond, Elly; Sepai, Ovnair; Exley, Karen; Bloemen, Louis; Knudsen, Lisbeth E; Kolossa-Gehring, Marike

2017-06-01

Human biomonitoring (HBM) is an effective tool to assess human exposure to environmental pollutants, but comparable HBM data in Europe are lacking. In order to expedite harmonization of HBM studies on a European scale, the twin projects COPHES (Consortium to Perform Human Biomonitoring on a European Scale) and DEMOCOPHES (Demonstration of a study to Coordinate and Perform Human Biomonitoring on a European Scale) were formed, comprising 35 partners from 27 European countries. In COPHES a research scheme and guidelines were developed to exemplarily measure in a pilot study mercury in hair, cadmium, cotinine and several phthalate metabolites in urine of 6-11year old children and their mothers in an urban and a rural region. Seventeen European countries simultaneously conducted this cross-sectional DEMOCOPHES feasibility study. The German study population was taken in the city of Bochum and in the Higher Sauerland District, comprising 120 mother-child pairs. In the present paper features of the study implementation are presented. German exposure concentrations of the pollutants are reported and compared with European average concentrations from DEMOCOPHES and with those measured in the representative German Environmental Survey (GerES IV). German DEMOCOPHES concentrations for mercury and cotinine were lower than the European average. However, 47% of the children were still exposed to environmental tobacco smoke (ETS) outside their home, which gives further potential for enhancing protection of children from ETS. Compared with samples from the other European countries German participating children had lower concentrations of the phthalate metabolites MEP and of the sum of 3 DEHP-metabolites (MEHP, 5OH-MEHP and 5oxo-MEHP), about the same concentrations of the phthalate metabolites MBzP and MiBP and higher concentrations of the phthalate metabolite MnBP. 2.5% of the German children had concentrations of the sum of 4 DEHP-metabolites and 4.2% had concentrations of MnBP that exceeded health based guidance values, indicating reasons for concern. Continuous HBM is necessary to track changes of pollutant exposure over time. Therefore Germany will continue to cooperate on the harmonisation of European human biomonitoring to support the chemicals regulation with the best possible exposure data to protect Europe's people against environmental health risks. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Quality control of the paracetamol drug by chemometrics and imaging spectroscopy in the near infrared region

NASA Astrophysics Data System (ADS)

Baptistao, Mariana; Rocha, Werickson Fortunato de Carvalho; Poppi, Ronei Jesus

2011-09-01

In this work, it was used imaging spectroscopy and chemometric tools for the development and analysis of paracetamol and excipients in pharmaceutical formulations. It was also built concentration maps to study the distribution of the drug in the tablets surface. Multivariate models based on PLS regression were developed for paracetamol and excipients concentrations prediction. For the construction of the models it was used 31 samples in the tablet form containing the active principle in a concentration range of 30.0-90.0% (w/w) and errors below to 5% were obtained for validation samples. Finally, the study of the distribution in the drug was performed through the distribution maps of concentration of active principle and excipients. The analysis of maps showed the complementarity between the active principle and excipients in the tablets. The region with a high concentration of a constituent must have, necessarily, absence or low concentration of the other one. Thus, an alternative method for the paracetamol drug quality monitoring is presented.

A Role of Fluoride on Free Radical Generation and Oxidative Stress in BV-2 Microglia Cells

PubMed Central

Shuhua, Xi; Ziyou, Liu; Ling, Yan; Fei, Wang; Sun, Guifan

2012-01-01

The generation of ROS and lipid peroxidation has been considered to play an important role in the pathogenesis of chronic fluoride toxicity. In the present study, we observed that fluoride activated BV-2 microglia cell line by observing OX-42 expression in immunocytochemistry. Intracellular superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), reactive oxygen species (ROS), superoxide anions (O2 ∙−), nitric oxide synthase (NOS), nitrotyrosine (NT) and nitric oxide (NO), NOS in cell medium were determined for oxidative stress assessment. Our study found that NaF of concentration from 5 to 20 mg/L can stimuli BV-2 cells to change into activated microglia displaying upregulated OX-42 expression. SOD activities significantly decreased in fluoride-treated BV-2 cells as compared with control, and MDA concentrations and contents of ROS and O2 ∙− increased in NaF-treated cells. Activities of NOS in cells and medium significantly increased with fluoride concentrations in a dose-dependent manner. NT concentrations also increased significantly in 10 and 50 mg/L NaF-treated cells compared with the control cells. Our present study demonstrated that toxic effects of fluoride on the central nervous system possibly partly ascribed to activiting of microglia, which enhanced oxidative stress induced by ROS and reactive nitrogen species. PMID:22933830

An exploration hydrogeochemical study at the giant Pebble porphyry Cu-Au-Mo deposit, Alaska, USA, using high-resolution ICP-MS

USGS Publications Warehouse

Eppinger, Robert G.; Fey, David L.; Giles, Stuart A.; Kelley, Karen D.; Smith, Steven M.

2012-01-01

A hydrogeochemical study using high resolution ICP-MS was undertaken at the giant Pebble porphyry Cu-Au-Mo deposit and surrounding mineral occurrences. Surface water and groundwater samples from regional background and the deposit area were collected at 168 sites. Rigorous quality control reveals impressive results at low nanogram per litre (ng/l) levels. Sites with pH values below 5.1 are from ponds in the Pebble West area, where sulphide-bearing rubble crop is thinly covered. Relative to other study area waters, anomalous concentrations of Cu, Cd, K, Ni, Re, the REE, Tl, SO42− and F− are present in water samples from Pebble West. Samples from circum-neutral waters at Pebble East and parts of Pebble West, where cover is much thicker, have anomalous concentrations of Ag, As, In, Mn, Mo, Sb, Th, U, V, and W. Low-level anomalous concentrations for most of these elements were also found in waters surrounding nearby porphyry and skarn mineral occurrences. Many of these elements are present in low ng/l concentration ranges and would not have been detected using traditional quadrupole ICP-MS. Hydrogeochemical exploration paired with high resolution ICP-MS is a powerful new tool in the search for concealed deposits.

Economic Inequality in Presenting Vision in Shahroud, Iran: Two Decomposition Methods.

PubMed

Mansouri, Asieh; Emamian, Mohammad Hassan; Zeraati, Hojjat; Hashemi, Hasan; Fotouhi, Akbar

2017-04-22

Visual acuity, like many other health-related problems, does not have an equal distribution in terms of socio-economic factors. We conducted this study to estimate and decompose economic inequality in presenting visual acuity using two methods and to compare their results in a population aged 40-64 years in Shahroud, Iran. The data of 5188 participants in the first phase of the Shahroud Cohort Eye Study, performed in 2009, were used for this study. Our outcome variable was presenting vision acuity (PVA) that was measured using LogMAR (logarithm of the minimum angle of resolution). The living standard variable used for estimation of inequality was the economic status and was constructed by principal component analysis on home assets. Inequality indices were concentration index and the gap between low and high economic groups. We decomposed these indices by the concentration index and BlinderOaxaca decomposition approaches respectively and compared the results. The concentration index of PVA was -0.245 (95% CI: -0.278, -0.212). The PVA gap between groups with a high and low economic status was 0.0705 and was in favor of the high economic group. Education, economic status, and age were the most important contributors of inequality in both concentration index and Blinder-Oaxaca decomposition. Percent contribution of these three factors in the concentration index and Blinder-Oaxaca decomposition was 41.1% vs. 43.4%, 25.4% vs. 19.1% and 15.2% vs. 16.2%, respectively. Other factors including gender, marital status, employment status and diabetes had minor contributions. This study showed that individuals with poorer visual acuity were more concentrated among people with a lower economic status. The main contributors of this inequality were similar in concentration index and Blinder-Oaxaca decomposition. So, it can be concluded that setting appropriate interventions to promote the literacy and income level in people with low economic status, formulating policies to address economic problems in the elderly, and paying more attention to their vision problems can help to alleviate economic inequality in visual acuity. © 2018 The Author(s); Published by Kerman University of Medical Sciences. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Percent recovery of low influent concentrations of microorganism surrogates in small sand columns

NASA Astrophysics Data System (ADS)

Stevenson, M. E.; Blaschke, A. P.

2012-04-01

In order to develop a dependable method to calculate the setback distance of a drinking water well from a potential point of microbiological contamination, surrogates are used to perform field tests to avoid using pathogenic micro-organisms. One such surrogate used to model the potential travel time of microbial contamination is synthetic microspheres. The goal of this study is to examine the effect of differing influent colloid concentrations on the percent recovery of microbial surrogates after passing through a soil column. Similar studies have been done to investigate blocking of ideal attachment sites using concentrations between 106 and 1010 particles ml-1. These high concentrations were necessary due to the detection limit of the measuring technique used; however, our measuring technique allows us to test input concentrations ranging from 101 to 106 particles ml-1. These low concentrations are more similar to the concentrations of pathogenic microorganisms present in nature. We have tested the enumeration of 0.5 μm microspheres using a solid-phase cytometer and evaluated their transport in small sand columns. Fluorescent microspheres were purchased for this study with carboxylated surfaces. The soil columns consist of Plexiglas tubes, 30 cm long and 7 cm in diameter, both filled with the same coarse sand. Bromide was used as a conservative tracer, to estimate pore-water velocity and dispersivity, and bromide concentrations were analysed using ion chromatography and bromide probes. Numerical modelling was done using CXTFIT and HYDRUS-1D software programs. The 0.5 μm beads were enumerated in different environmental waters using solid-phase cytometry and compared to counts in sterile water in order to confirm the accuracy of the method. The solid-phase cytometer was able to differentiate the 0.5 μm beads from naturally present autofluorescent particles and bacteria, and therefore, is an appropriate method to enumerate this surrogate.

Effect of vitamin E intake from food and supplement sources on plasma α- and γ-tocopherol concentrations in a healthy Irish adult population.

PubMed

Zhao, Yang; Monahan, Frank J; McNulty, Breige A; Gibney, Mike J; Gibney, Eileen R

2014-11-14

Vitamin E is believed to play a preventive role in diseases associated with oxidative stress. The aims of the present study were to quantify vitamin E intake levels and plasma concentrations and to assess dietary vitamin E adequacy in Irish adults. Intake data from the National Adult Nutrition Survey were used; plasma samples were obtained from a representative cohort of survey participants. Plasma α- and γ-tocopherol concentrations were measured by HPLC. The main sources of vitamin E in the diet were 'butter, spreadable fats and oils' and 'vegetables and vegetable dishes'. When vitamin E intake from supplements was taken into account, supplements were found to be the main contributor, making a contribution of 29·2 % to vitamin E intake in the total population. Supplement consumers had significantly higher plasma α-tocopherol concentrations and lower plasma γ-tocopherol concentrations when compared with non-consumers. Consumers of 'vitamin E' supplements had significantly higher vitamin E intake levels and plasma α-tocopherol concentrations compared with consumers of other types of supplements, such as multivitamin and fish oil. Comparison with the Institute of Medicine Estimated Average Requirement of 12 mg/d indicated that when vitamin E intake from food and supplement sources was taken into account, 100 % of the study participants achieved the recommended intake levels. When vitamin E intake from food sources was taken into account, only 68·4 % of the females were found to achieve the recommended intake levels compared with 99·2 % of the males. The results of the present study show that dietary vitamin E intake has a significant effect on plasma α- and γ-tocopherol concentrations. Furthermore, they show that the consumption of supplements is a major contributor to overall intake and has a significant effect on plasma vitamin E concentrations in the Irish population.

Screening and human health risk assessment of pharmaceuticals and their transformation products in Dutch surface waters and drinking water.

PubMed

de Jongh, Cindy M; Kooij, Pascal J F; de Voogt, Pim; ter Laak, Thomas L

2012-06-15

Numerous studies describe the presence of pharmaceuticals in the water cycle, while their transformation products are usually not included. In the current study 17 common pharmaceuticals and 9 transformation products were monitored in the Dutch waters, including surface waters, pre-treated surface waters, river bank filtrates, two groundwater samples affected by surface water and drinking waters. In these samples, 12 pharmaceuticals and 7 transformation products were present. Concentrations were generally highest in surface waters, intermediate in treated surface waters and river bank filtrates and lowest or not detected in produced drinking water. However, the concentrations of phenazone and its environmental transformation product AMPH were significantly higher in river bank filtrates, which is likely due to historical contamination. Fairly constant ratios were observed between concentrations of transformation products and parent pharmaceuticals. This might enable prediction of concentrations of transformation products from concentrations of parent pharmaceuticals. The toxicological relevance of the observed pharmaceuticals and transformation products was assessed by deriving (i) a substance specific provisional guideline value (pGLV) and (ii) a group pGLV for groups of related compounds were under the assumption of additivity of effects within each group. A substantial margin exists between the maximum summed concentrations of these compounds present in different water types and the derived (group) pGLVs. Based on the results of this limited screening campaign no adverse health effects of the studied compounds are expected in (sources of) drinking water in the Netherlands. The presence of transformation products with similar pharmacological activities and concentration levels as their parents illustrates the relevance of monitoring transformation products, and including these in risk assessment. More thorough monitoring yielding information on statistical uncertainty and variability in time and space, and research on possible synergistic effects of low concentration mixtures of compounds belonging to similar pharmacological classes require attention. Copyright © 2012 Elsevier B.V. All rights reserved.

Sensory effect of acetaldehyde on the perception of 3-mercaptohexan-1-ol and 3-isobutyl-2-methoxypyrazine: Role of acetaldehyde in sensory interactions

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

Coetzee, C.; Brand, J.; Jacobson, Daniel A.

Background and Aims-Wine aroma is influenced by complex interactions between various wine constituents. This study investigated the sensory interactive effects of Sauvignon Blanc impact compounds, 3-mercaptohexan-1-ol and 3-isobutyl-2-methoxypyrazine, with acetaldehyde that typically forms during the oxidation of wine. Methods and Results-Spiked model wines were subjected to sensory descriptive analysis using a trained sensory panel. Additionally, the concentration of each compound varied from below aroma threshold values to high values as reported for wine. Depending on the concentration, acetaldehyde enhanced fruity attributes at a lower concentration, whereas suppression occurred at a higher concentration. Acetaldehyde effectively suppressed the green pepper aroma attributemore » at certain concentration values, whereas 3-mercaptohexan-1-ol suppressed oxidised green apple associated with acetaldehyde. Changes in attributes used for aroma description also occurred because of change in concentration. Conclusions-Complex sensory interactions may occur between Sauvignon Blanc impact compounds and one of the main oxidation-derived compounds, acetaldehyde. Acetaldehyde can enhance or suppress pleasant fruity characters depending on the concentration. Significance of the Study-This study showed the potential positive effect of acetaldehyde on white wine aroma when present at a low concentration. Formation of this compound during winemaking and ageing should, however, be controlled because of negative sensory interactions occurring at a higher concentration. In conclusion, this study may also contribute to the sensory characterisation of Sauvignon Blanc wine undergoing oxidation.« less

Sensory effect of acetaldehyde on the perception of 3-mercaptohexan-1-ol and 3-isobutyl-2-methoxypyrazine: Role of acetaldehyde in sensory interactions

DOE PAGES

Coetzee, C.; Brand, J.; Jacobson, Daniel A.; ...

2016-01-28

Background and Aims-Wine aroma is influenced by complex interactions between various wine constituents. This study investigated the sensory interactive effects of Sauvignon Blanc impact compounds, 3-mercaptohexan-1-ol and 3-isobutyl-2-methoxypyrazine, with acetaldehyde that typically forms during the oxidation of wine. Methods and Results-Spiked model wines were subjected to sensory descriptive analysis using a trained sensory panel. Additionally, the concentration of each compound varied from below aroma threshold values to high values as reported for wine. Depending on the concentration, acetaldehyde enhanced fruity attributes at a lower concentration, whereas suppression occurred at a higher concentration. Acetaldehyde effectively suppressed the green pepper aroma attributemore » at certain concentration values, whereas 3-mercaptohexan-1-ol suppressed oxidised green apple associated with acetaldehyde. Changes in attributes used for aroma description also occurred because of change in concentration. Conclusions-Complex sensory interactions may occur between Sauvignon Blanc impact compounds and one of the main oxidation-derived compounds, acetaldehyde. Acetaldehyde can enhance or suppress pleasant fruity characters depending on the concentration. Significance of the Study-This study showed the potential positive effect of acetaldehyde on white wine aroma when present at a low concentration. Formation of this compound during winemaking and ageing should, however, be controlled because of negative sensory interactions occurring at a higher concentration. In conclusion, this study may also contribute to the sensory characterisation of Sauvignon Blanc wine undergoing oxidation.« less

Deuterium depth profile quantification in a ASDEX Upgrade divertor tile using secondary ion mass spectrometry

NASA Astrophysics Data System (ADS)

Ghezzi, F.; Caniello, R.; Giubertoni, D.; Bersani, M.; Hakola, A.; Mayer, M.; Rohde, V.; Anderle, M.; ASDEX Upgrade Team

2014-10-01

We present the results of a study where secondary ion mass spectrometry (SIMS) has been used to obtain depth profiles of deuterium concentration on plasma facing components of the first wall of the ASDEX Upgrade tokamak. The method uses primary and secondary standards to quantify the amount of deuterium retained. Samples of bulk graphite coated with tungsten or tantalum-doped tungsten are independently profiled with three different SIMS instruments. Their deuterium concentration profiles are compared showing good agreement. In order to assess the validity of the method, the integrated deuterium concentrations in the coatings given by one of the SIMS devices is compared with nuclear reaction analysis (NRA) data. Although in the case of tungsten the agreement between NRA and SIMS is satisfactory, for tantalum-doped tungsten samples the discrepancy is significant because of matrix effect induced by tantalum and differently eroded surface (W + Ta always exposed to plasma, W largely shadowed). A further comparison where the SIMS deuterium concentration is obtained by calibrating the measurements against NRA values is also presented. For the tungsten samples, where no Ta induced matrix effects are present, the two methods are almost equivalent.The results presented show the potential of the method provided that the standards used for the calibration reproduce faithfully the matrix nature of the samples.

Impact of polystyrene microplastics on Daphnia magna mortality and reproduction in relation to food availability

PubMed Central

Aljaibachi, Rana

2018-01-01

Microplastics (MPs) in the environment continue to be a growing area of concern in terms of acute and chronic impacts on aquatic life. Whilst increasing numbers of studies are providing important insights into microparticle behaviour and impacts in the marine environment, a paucity of information exists regarding the freshwater environment. This study focusses on the uptake, retention and the impact of 2 µm polystyrene MPs in the freshwater cladoceran Daphnia magna in relation to food intake (algae Chlorella vulgaris), with MP size chosen to approximately match the cell size of the algae. Daphnia were exposed to varied concentrations of MPs and algae. When exposed to a single concentration of MPs Daphnia almost immediately ate them in large quantities. However, the presence of algae, even at low concentrations, had a significant negative impact on MP uptake that was not in proportion to relative availability. As MP concentrations increased, intake did not if algae were present, even at higher concentrations of MPs. This suggests that Daphnia are selectively avoiding eating plastics. Adult Daphnia exposed to MPs for 21 days showed mortality after seven days of exposure in all treatments compared to the control. However significant differences were all related to algal concentration rather than to MP concentration. This suggests that where ample food is present, MPs have little effect on adults. There was also no impact on their reproduction. The neonate toxicity test confirmed previous results that mortality and reproduction was linked to availability of food rather than MP concentrations. This would make sense in light of our suggestion that Daphnia are selectively avoiding eating microplastics. PMID:29686944

Weathering and evaporation controls on dissolved uranium concentrations in groundwater - A case study from northern Burundi.

PubMed

Post, V E A; Vassolo, S I; Tiberghien, C; Baranyikwa, D; Miburo, D

2017-12-31

The potential use of groundwater for potable water supply can be severely compromised by natural contaminants such as uranium. The environmental mobility of uranium depends on a suite of factors including aquifer lithology, redox conditions, complexing agents, and hydrological processes. Uranium concentrations of up to 734μg/L are found in groundwater in northern Burundi, and the objective of the present study was to identify the causes for these elevated concentrations. Based on a comprehensive data set of groundwater chemistry, geology, and hydrological measurements, it was found that the highest dissolved uranium concentrations in groundwater occur near the shores of Lake Tshohoha South and other smaller lakes nearby. A model is proposed in which weathering and evapotranspiration during groundwater recharge, flow and discharge exert the dominant controls on the groundwater chemical composition. Results of PHREEQC simulations quantitatively confirm this conceptual model and show that uranium mobilization followed by evapo-concentration is the most likely explanation for the high dissolved uranium concentrations observed. The uranium source is the granitic sand, which was found to have a mean elemental uranium content of 14ppm, but the exact mobilization process could not be established. Uranium concentrations may further be controlled by adsorption, especially where calcium-uranyl‑carbonate complexes are present. Water and uranium mass balance calculations for Lake Tshohoha South are consistent with the inferred fluxes and show that high‑uranium groundwater represents only a minor fraction of the overall water input to the lake. These findings highlight that the evaporation effects that cause radionuclide concentrations to rise to harmful levels in groundwater discharge areas are not only confined to arid regions, and that this should be considered when selecting suitable locations for water supply wells. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of animal-assisted therapy on concentration and attention span in patients with acquired brain injury: A randomized controlled trial.

PubMed

Gocheva, Vanya; Hund-Georgiadis, Margret; Hediger, Karin

2018-01-01

Previous studies have reported that brain-injured patients frequently suffer from cognitive impairments such as attention and concentration deficits. Numerous rehabilitation clinics offer animal-assisted therapy (AAT) to address these difficulties. The authors' aim was to investigate the immediate effects of AAT on the concentration and attention span of brain-injured patients. Nineteen patients with acquired brain injury were included in a randomized, controlled, within-subject trial. The patients alternately received 12 standard therapy sessions (speech therapy, physiotherapy, occupational therapy) and 12 paralleled AAT sessions with comparable content. A total of 429 therapy sessions was analyzed consisting of 214 AAT and 215 control sessions. Attention span and instances of distraction were assessed via video coding in Noldus Observer. The Mehrdimensionaler Befindlichkeitsbogen ([Multidimensional Affect Rating Scale] MDBF questionnaire; Steyer, Schwenkmezger, Notz, & Eid, 1997) was used to measure the patient's self-rated alertness. Concentration was assessed through Visual Analogue Scale (VAS) via self-assessment and therapist's ratings. The patients' attention span did not differ whether an animal was present or not. However, patients displayed more instances of distraction during AAT. Moreover, patients rated themselves more concentrated and alert during AAT sessions. Further, therapists' evaluation of patients' concentration indicated that patients were more concentrated in AAT compared with the control condition. Although the patients displayed more instances of distraction while in the presence of an animal, it did not have a negative impact on their attention span. In addition, patients reported to be more alert and concentrated when an animal was present. Future studies should examine other attentional processes such as divided attention and include neurobiological correlates of attention. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

PAHs, NITRO-PAHs, HOPANES, AND STERANES IN LAKE TROUT FROM LAKE MICHIGAN

PubMed Central

Huang, Lei; Chernyak, Sergei M.; Batterman, Stuart A.

2015-01-01

The present study examines concentrations and risks of polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), steranes, and hopanes in lake trout collected in Lake Michigan. A total of 74 fish were collected in 2 seasons at 3 offshore sites. The total PAH concentration (Σ9PAH) in whole fish ranged from 223 pg/g to 1704 pg/g wet weight, and PAH concentrations and profiles were similar across season, site, and sex. The total NPAH (Σ9NPAH) concentrations ranged from 0.2 pg/g to 31 pg/g wet weight, and carcinogenic compounds, including 1-nitropyrene and 6-nitrochrysene, were detected. In the fall, NPAH concentrations were low at the Illinois site (0.2–0.5 pg/g wet wt), and site profiles differed considerably; in the spring, concentrations and profiles were similar across sites, possibly reflecting changes in fish behavior. In the fall, the total sterane (Σ5Sterane) and total hopane (Σ2Hopane) levels reached 808 pg/g and 141 pg/g wet weight, respectively, but concentrations in the spring were 10 times lower. Concentrations in eggs (fall only) were on the same order of magnitude as those in whole fish. These results demonstrate the presence of target semivolatile organic compounds in a top predator fish, and are consistent with PAH biodilution observed previously. Using the available toxicity information for PAHs and NPAHs, the expected cancer risk from consumption of lake trout sampled are low. However, NPAHs contributed a significant portion of the toxic equivalencies in some samples. The present study provides the first measurements of NPAHs in freshwater fish, and results suggest that additional assessment is warranted. PMID:24764175

Investigations on the structure of Pb-Ge-Se glasses

NASA Astrophysics Data System (ADS)

Kalra, G.; Upadhyay, M.; Sharma, Y.; Abhaya, S.; Murugavel, S.; Amarendra, G.

2016-05-01

Chalcogenide glasses have attracted much attention because of their potential application in various solid state devices. In the present work, we report here the detailed thermal, structural, microstructural studies on PbxGe42-xSe58 with (0 ≤ x ≤ 20) glasses. The influence of Pb content on the glass transition temperature, specific heat, and non-reversing enthalphy is observed and discussed qualitatively The Raman spectroscopic studies on the all the glass compositions are carried out and deconvoluted into different structural units. The positron annihilation life-time spectroscopy (PALS) studies helped to understand the nature of defect states present in the glassy system and its variation with Pb content. The concentration of charged defect centers is found to increase, whereas the open volume defect concentration decreases with Pb content in these glasses.

Trace elements in blood of sea turtles Lepidochelys olivacea in the Gulf of California, Mexico.

PubMed

Zavala-Norzagaray, A A; Ley-Quiñónez, C P; Espinosa-Carreón, T L; Canizalez-Román, A; Hart, C E; Aguirre, A A

2014-11-01

This study determined the concentrations of heavy metals in blood collected from Pacific Ridley sea turtles (Lepidochelys olivacea) inhabiting the coast of Guasave, Mexico, in the Gulf of California. The highest reported metal concentration in blood was Zn, followed by Se. Of nonessential toxic metals, As was reported in higher percentage compared to Cd. The concentrations of metals detected were present as follows: Zn > Se > Mn > As > Ni > Cd > Cu. Cd concentration in blood is higher in our population in comparison with other populations of L. olivacea, and even higher in other species of sea turtles. Our study reinforces the usefulness of blood for the monitoring of the levels of contaminating elements, and is easily accessible and nonlethal for sea turtles.

Sandy beach molluscs as possible bio-indicators of metal pollution 2. laboratory studies. [South Africa

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

Watling, H.R.; Watling, R.J.

Donax serra and Bullia rhodostoma have been selected as possible indicators of metal pollution and the results of a survey of the metal concentrations in these two molluscs have been summarized. The present study is concerned with the ability of these molluscs to accumulate metals, without being killed by levels encountered, in such a way that the rates of accumulation can be related to the average metal concentration in the surrounding water.

Case studies of of the oxidation of sulphur dioxide in a hill cap cloud using ground and aircraft based measurements

NASA Astrophysics Data System (ADS)

Gallagher, M. W.; Downer, R. M.; Choularton, T. W.; Gay, M. J.; Stromberg, I.; Mill, C. S.; Radojevic, M.; Tyler, B. J.; Bandy, B. J.; Penkett, S. A.; Davies, T. J.; Dollard, G. J.; Jones, B. M. R.

1990-10-01

Two case studies are presented which investigate the aqueous phase oxidation of sulfur dioxide (SO2) within a cap cloud on the summit of Great Dun Fell (847 m above sea level) in England. Data gathered by aircraft showed that hydrogen peroxide (H2O2) concentrations in the free troposphere were much greater than near the ground and that entrainment of air containing H2O2, into the cap cloud could provide a significant supply of oxidant. These findings suggest that the entrainment of H2O2 into cloud systems may be important to the oxidation of SO2, particularly in the absence of large concentrations of ammonia gas, which may favor oxidation by ozone. It is also shown that the apparent reaction rate of H2O2 within the cloud is consistent with our previous estimates made and were substantially larger than would be predicted from laboratory studies in bulk solutions (Chandler et al., 1988b). Sulphate, (SO42-), production was observed when significant concentrations of SO2 were present. The measured concentrations of the principal species involved in one of the case studies were consistent with model predictions which take account of SO2 oxidation by H2O2 and O3 and an enhanced H2O2-SO2 reaction rate.

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.

Trace elements in loggerhead turtles (Caretta caretta) stranded in mainland Portugal: Bioaccumulation and tissue distribution.

PubMed

Nicolau, Lídia; Monteiro, Sílvia S; Pereira, Andreia T; Marçalo, Ana; Ferreira, Marisa; Torres, Jordi; Vingada, José; Eira, Catarina

2017-07-01

Pollution is among the most significant threats that endanger sea turtles worldwide. Waters off the Portuguese mainland are acknowledged as important feeding grounds for juvenile loggerheads. However, there is no data on trace element concentrations in marine turtles occurring in these waters. We present the first assessment of trace element concentrations in loggerhead turtles (Caretta caretta) occurring off the coast of mainland Portugal. Also, we compare our results with those from other areas and discuss parameters that may affect element concentrations. Trace element concentrations (As, Cd, Cu, Pb, Mn, Hg, Ni, Se, Zn) were determined in kidney, liver and muscle samples from 38 loggerheads stranded between 2011 and 2013. As was the only element with higher concentrations in muscle (14.78 μg g -1 ww) than in liver or kidney. Considering non-essential elements, Cd presented the highest concentrations in kidney (34.67 μg g -1 ) and liver (5.03 μg g -1 ). Only a weak positive link was found between renal Cd and turtle size. Inter-elemental correlations were observed in both liver and kidney tissues. Hepatic Hg values (0.30 ± 0.03 μg g -1 ) were higher than values reported in loggerheads in the Canary Islands but lower than in Mediterranean loggerheads. Cd concentrations in the present study were only exceeded by values found in turtles from the Pacific. Although many endogenous and exogenous parameters related with complex life cycle changes and wide geographic range may influence trace element accumulation, the concentrations of Cd are probably related to the importance of crustaceans in loggerhead diet in the Portuguese coast. Copyright © 2017 Elsevier Ltd. All rights reserved.

Histopathological Changes in Tissues of Bithynia siamensis goniomphalos Incubated in Crude Extracts of Camellia Seed and Mangosteen Pericarp

PubMed Central

Aukkanimart, Ratchadawan; Pinlaor, Somchai; Tesana, Smarn; Aunpromma, Surasit; Booyarat, Chantana; Sriraj, Pranee; Laummaunwai, Porntip; Punjaruk, Wiyada

2013-01-01

The present study was performed to observe histopathological changes in tissues of Bithynia siamensis goniomphalos (Gastropoda, Bithyniidae) incubated in crude extract solutions of camellia (Camellia oleifera) seed and mangosteen (Garcinia mangostana) pericarp, and furthermore to estimate the molluscicidal effects of 2 plant substances. Substantial numbers of bithyniid snails were incubated in various concentrations of 2 plant solution for 24 hr. As the positive control, snails incubated in various concentrations of niclosamide, a chemical molluscicide, were used. The histopathological findings were observed in sectioned snail specimens of each experimental and control groups. The results showed that both camellia and mangosteen extracts had molluscicidal effects at 24 hr with 50% lethal concentration (LC50) at concentrations of 0.003 and 0.002 g/ml, respectively, while niclosamide had LC50 at concentrations 0.599 ppm. B. siamensis goniomphalos snail tissues (foot, gill, and digestive system) showed disruption of columnar muscle fibers of the foot, reduction of the length and number of gill cilia, numerous mucous vacuoles, and irregularly shaped of epithelial cells. Irregular apical and calciferous cells, dilatation of the digestive gland tubule, and large hemolymphatic spaces, and irregular apical surfaces, detachment of cilia, and enlargement of lysosomal vacuoles of epidermis were also shown in all groups. By the present study, it is confirmed that 2 plants, camellia and mangosteen, are keeping some substance having molluscicidal effects, and histopathological findings obtained in this study will provide some clues in further studies on their action mechanisms to use them as natural molluscicides. PMID:24327779

Assessment of airborne virus contamination in wastewater treatment plants.

PubMed

Masclaux, Frédéric G; Hotz, Philipp; Gashi, Drita; Savova-Bianchi, Dessislava; Oppliger, Anne

2014-08-01

Occupational exposure to bioaerosols in wastewater treatment plants (WWTP) and its consequence on workers' health are well documented. Most studies were devoted to enumerating and identifying cultivable bacteria and fungi, as well as measuring concentrations of airborne endotoxins, as these are the main health-related factors found in WWTP. Surprisingly, very few studies have investigated the presence and concentrations of airborne virus in WWTP. However, many enteric viruses are present in wastewater and, due to their small size, they should become aerosolized. Two in particular, the norovirus and the adenovirus, are extremely widespread and are the major causes of infectious gastrointestinal diseases reported around the world. The third one, hepatitis E virus, has an emerging status. This study׳s objectives were to detect and quantify the presence and concentrations of 3 different viruses (adenovirus, norovirus and the hepatitis E virus) in air samples from 31 WWTPs by using quantitative polymerase chain reaction (qPCR) during two different seasons and two consecutive years. Adenovirus was present in 100% of summer WWTP samples and 97% of winter samples. The highest airborne concentration measured was 2.27 × 10(6) genome equivalent/m(3) and, on average, these were higher in summer than in winter. Norovirus was detected in only 3 of the 123 air samples, and the hepatitis E virus was not detected. Concentrations of potentially pathogenic viral particles in WWTP air are non-negligible and could partly explain the work-related gastrointestinal symptoms often reported in employees in this sector. Copyright © 2014 Elsevier Inc. All rights reserved.

Influence of L-thyroxine administration on poor-platelet plasma VEGF concentrations in patients with induced short-term hypothyroidism, monitored for thyroid carcinoma.

PubMed

Dedecjus, Marek; Kołomecki, Krzysztof; Brzeziński, Jan; Adamczewski, Zbigniew; Tazbir, Józef; Lewiński, Andrzej

2007-02-01

Angiogenesis is a process of new blood vessel development from pre-existing vasculature. It is a crucial process in normal physiology, as well as in several pathological conditions. The vascular endothelial growth factor (VEGF) represents a family of specific endothelial cell mitogens, involved in normal angiogenesis and in tumour development. The aim of the present study was to estimate the influence of L-thyroxine (L-T4) administration on poor-platelet plasma (P-PP) VEGF concentrations in patients with induced short-term hypothyroidism, monitored for differentiated thyroid carcinoma. In the present study, P-PP concentrations of VEGF, thyroglobulin, thyrotropin and free thyroid hormones were investigated in a population of 24 hypothyroid patients, who were withdrawn from L-T4 treatment for 5 weeks and studied before and after 2 months of L-T4 therapy. Only healthy female patients with no evidence of metastasis in whole body scintigraphy were included in the study. They were then compared with 20 healthy control subjects, matched for age, sex and body mass index (BMI). The patients had significantly lower plasma VEGF concentrations before treatment with L-T4 than after administration of that hormone. There was no significant difference in plasma VEGF levels, either between the patients treated with L-T4, and the controls, or between the patients untreated with L-T4, and the controls. Even short-time changes in thyrometabolic profile exert an important influence on P-PP VEGF concentrations, even if there is no thyroid tissue.

Using bald eagles to track spatial (1999-2008) and temporal (1987-1992, 1999-2003, and 2004-2008) trends of contaminants in Michigan's aquatic ecosystems.

PubMed

Wierda, Michael R; Leith, Katherine F; Roe, Amy S; Grubb, Teryl G; Sikarskie, James G; Best, David A; Pittman, H Tyler; Fuentes, Latice; Simon, Kendall L; Bowerman, William

2016-08-01

The bald eagle (Haliaeetus leucocephalus) is an extensively researched tertiary predator. Studies have delineated information about its life history and the influences of various stressors on its reproduction. Due to the bald eagle's position at the top of the food web, it is susceptible to biomagnification of xenobiotics. The Michigan Department of Environmental Quality implemented a program in 1999 to monitor persistent chemicals including polychlorinated biphenols (PCBs) and dichlorodiphenyltrichloroethane (DDE). The objectives of the present study were to evaluate spatial and temporal trends of PCBs and organochlorine pesticides in nestling bald eagles of Michigan. The authors' study found that concentrations of PCBs and DDE were higher in Great Lakes areas with Lakes Michigan and Lake Huron having the highest concentrations of DDE and Lake Erie having the highest concentrations of PCBs. Temporally (1987-1992, 1999-2003, and 2004-2008) the present study found declines in PCB and DDE concentrations with a few exceptions. Continued monitoring of Michigan bald eagle populations is suggested for a couple of reasons. First, nestling blood contaminant levels are an appropriate method to monitor ecosystem contaminant levels. Second, from 1999 to 2008 PCB and DDE concentrations for 30% and 40%, respectively, of the nestling eagles sampled were above the no observable adverse effect level (NOAEL) for bald eagles. Lastly, with the continued development and deployment of new chemistries a continuous long term monitoring program is an invaluable resource. Environ Toxicol Chem 2016;35:1995-2002. © 2016 SETAC. © 2016 SETAC.

Pharmacokinetics of rectal levetiracetam as add-on treatment in dogs affected by cluster seizures or status epilepticus.

PubMed

Cagnotti, Giulia; Odore, Rosangela; Gardini, Giulia; Amedeo, Stefano; Bertone, Iride; Guerriero, Giulia; Lentini, Laura; Dappiano, Elena; D'Angelo, Antonio

2018-06-18

Levetiracetam can be used for seizure control alone or in combination with other antiepileptic medications. A previous study achieved the minimum targeted serum drug concentration after rectal administration of levetiracetam in healthy dogs. The purpose of the present study was to determine the pharmacokinetics of rectal LEV in dogs presented for cluster seizures or status epilepticus and potentially in treatment with other anti-epileptic drugs. Furthermore, preliminary information on response to this treatment as add-on to the standard treatment protocol is reported. Eight client-owned dogs were enrolled. Plasma levetiracetam concentrations (measured at 0, 30, 60, 90, 120, 180, 240, 360, 720, and 1440 min after drug administration) reached the minimum target concentration (5 μg/ml) at 30 min in all but one patient. At T1 (30 min) the mean concentration was 28.2 ± 15.5 μg/ml. Plasma concentrations remained above the targeted minimum concentration in all patients until 240 min and in 7/8 until 360 min. Six out of eight patients experienced no seizures in the 24-h period after hospitalization and were classified as "responders". Minimum plasma levetiracetam concentration can be reached after rectal administration of 40 mg/kg in dogs affected by cluster seizures and status epilepticus and concurrently receiving other antiepileptic drugs. These preliminary results may encourage the evaluation of rectal levetiracetam as an additional treatment option for cluster seizures and status epilepticus in a larger number of dogs.

Capsaicin-induced activation of ERK1/2 and its involvement in GAP-43 expression and CGRP depletion in organotypically cultured DRG neurons.

PubMed

Li, Yunfeng; Liu, Guixiang; Li, Hao; Xu, Youzheng; Zhang, Hong; Liu, Zhen

2013-04-01

Low concentrations of capsaicin (CAP) stimulate and high concentrations of CAP can be toxic to the primary sensory neurons of the dorsal root ganglion (DRG). CAP induces the phosphorylation of extracellular signal-regulated protein kinases 1/2 (ERK1/2) in DRG neurons. The effect of the activation of ERK1/2 by different concentrations of CAP on growth-associated protein 43 (GAP-43) expression and calcitonin gene-related peptide (CGRP) depletion in DRG neurons remains unknown. In the present study, organotypic embryonic 15-day-old rat DRG explants were used to determine the effect of different concentrations of CAP on GAP-43 expression and CGRP depletion. The results showed that, compared to unstimulated control cultures, GAP-43 and pERK1/2 protein levels increased at a low concentration (2 μmol/L) of CAP and decreased at a higher concentration (10 μmol/L). The number of CGRP-immunoreactive (IR) migrating neurons also decreased in CAP-treated cultures. The increase in GAP-43 levels and CGRP depletion could be blocked by the administration of ERK1/2 inhibitor PD98059. The results of the present study imply that CAP at different concentrations has different effects on GAP-43 expression and CGRP depletion. These effects were involved in the activation of ERK1/2 in organotypically cultured DRG neurons stimulated with CAP. These data may provide new insights for further development potential therapeutic applications of CAP with moderate dose on neurogenic inflammation.

Determination of polychlorinated biphenyls, selected persistent organochlorine pesticides, and polybrominated flame retardants in fillets of fishes from the 2007 Missouri Department of Conservation Monitoring Program

USGS Publications Warehouse

Gale, Robert W.; Orazio, Carl E.; McKee, Michael J.

2009-01-01

This report presents the results of a study to determine polychlorinated biphenyl, organochlorine pesticide, and polybrominated diphenylether flame retardant concentrations in selected fishes from lakes and streams across Missouri. Fillets were collected from each fish sample and after homogenization, compositing, and preparation, analyte concentrations were determined with dual column capillary gas chromatography-electron-capture detection. Total concentrations of polychlorinated biphenyls in samples ranged from background levels of about 50 to 300 nanograms per gram. In samples with elevated contaminant concentrations, chlordanes, DDT-related chemicals, and dieldrin constituted the primary classes of pesticides present, and ranged from 5 to 75 nanograms per gram. Total concentrations of polybrominated diphenyl ethers in samples ranged from background levels of 5 to 86 nanograms per gram. Channel catfish from the upper and lower Blue River and lake sturgeon from the Mississippi River at Saverton exhibited different polybrominated diphenyl ethers ratios. Concentrations of polychlorinated biphenyls, chlordanes, DDT-related compounds, and polybrominated diphenyl ethers all were greatest in samples of channel catfish from the upper and lower Blue River, and in samples of lake sturgeon from the Mississippi River at Saverton.

Particulate Matter Mass and Number Concentrations Inside a Naturally Ventilated School Building Located Adjacent to an Urban Roadway

NASA Astrophysics Data System (ADS)

Chithra, V. S.; Shiva Nagendra, S. M.

2014-09-01

This work presents the temporal characteristics of Particulate Matter (PM) mass and number concentrations measured inside a naturally ventilated school building, located close to a busy roadway in Chennai city. Two environmental dust monitor instruments (GRIMM Model 107 and Model 108) were used for measuring PM mass and number concentrations. The 1-h mean values of PM10, PM2.5 and PM1 mass concentrations were found to be 262 ± 161, 68 ± 24, 40 ± 15 µg/m3 and 81 ± 26, 56 ± 2, 45 ± 19 µg/m3 during working hours (8am-4pm) and non-working hours (4pm-8am)/holidays, respectively. The PM number concentrations inside the room during working hours were found to be 2.4 × 105, 2.2 × 103 and 8.1 × 102 particles/l in the size range of 0.3-1, 1-3 and 3-10 µm, respectively. The present study reveals that during working hours, indoor PM concentrations of the classroom were influenced by the activities of occupants and during non working hours it was affected by outdoor vehicular emissions.

Agricultural Spray Drift Concentrations in Rainwater, Stemflow ...

EPA Pesticide Factsheets

In order to study spray drift contribution to non-targeted habitats, pesticide concentrations were measured in stemflow (water flowing down the trunk of a tree during a rain event), rainfall, and amphibians in an agriculturally impacted wetland area near Tifton, Georgia, USA. Agricultural fields and sampling locations were located on the University of Georgia's Gibbs research farm. Samples were analyzed for >150 pesticides and over 20 different pesticides were detected in these matrices. Data indicated that herbicides (metolachlor and atrazine) and fungicides (tebuconazole) were present with the highest concentrations in stemflow, followed by those in rainfall and amphibian tissue samples. Metolachlor had the highest frequency of detection and highest concentration in rainfall and stemflow samples. Higher concentrations of pesticides were observed in stemflow for a longer period than rainfall. Furthermore, rainfall and stemflow concentrations were compared against aquatic life benchmarks and environmental water screening values to determine if adverse effects would potentially occur for non-targeted organisms. Of the pesticides detected, several had concentrations that exceeded the aquatic life benchmark value. The majority of the time mixtures were present in the different matrices, making it difficult to determine the potential adverse effects that these compounds will have on non-target species, due to unknown potentiating effects. These data help assess the

Ultrasound assisted forward osmosis concentration of fruit juice and natural colorant.

PubMed

Chanukya, B S; Rastogi, Navin K

2017-01-01

The present study deals with the effect of higher and lower molecular weight compounds present in the feed on concentration polarization during forward osmosis concentration and its mitigation by the application of ultrasound. The effects of ultrasound on transmembrane water flux at different forward osmosis membrane orientations and different model feed solutions consisting of sucrose and pectin have also been evaluated. The feed containing sucrose and pectin subjected towards active layer of the membrane was found to be the most suitable orientation. The application of ultrasound (30kHz) significantly reduced the concentration polarization when the feed contains sucrose concentration up to 5%. Whereas, in case of feed containing 0.5% pectin, the ultrasound was not found to be effective in dislodging the gel layer formation resulting in severe external concentration polarization on the membrane surface. In comparison to the ordinary forward osmosis process, the ultrasound-assisted forward osmosis process resulted in higher water fluxes in case of sweet lime juice as well as rose extract containing anthocyanin. The degradation of rose anthocyanin due to ultrasound was found to be 1.82%. Application of ultrasound was found to be an effective way in mitigating concentration polarization on the forward osmosis membrane resulting in increased flux. Copyright © 2016 Elsevier B.V. All rights reserved.

Concentration and risk assessment of phthalates present in indoor air from newly decorated apartments

NASA Astrophysics Data System (ADS)

Pei, X. Q.; Song, M.; Guo, M.; Mo, F. F.; Shen, X. Y.

2013-04-01

Phthalate esters (PAEs) are ubiquitous in the indoor environment, owing to their use in consumer products. People spend a considerable amount of time indoors. As a result, human exposure to indoor contaminants is of great concern. People are exposed to phthalates through inhalation and dermal absorption of indoor air. In this study, the concentrations, characteristics and carcinogenic risks of gas-phase and particle-phase phthalates in indoor air from bedroom, living room and study room of 10 newly decorated apartments in Hangzhou, China were first investigated. The mean concentration of phthalates (gas-phase and particle-phase) present in household air was 12 096.4 ng m-3, of which diethyl phthalate (DEP), butylbenzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP) were the most abundant compounds with concentrations of 2290 ng m-3, 3975 ng m-3 and 2437 ng m-3, respectively, totally accounting for 72.0% of ∑6PAEs. Contamination levels of phthalates varied in different compartments. The concentration of phthalates was the highest 17 363.7 ng m-3 in living room, followed with 11 389.5 ng m-3 in study room, and the lowest 9739.1 ng m-3 in bedroom. It was also found that phthalates mainly accumulated in gaseous form in household air. DEHP posed the greatest health risk to children aged 1-2. Carcinogenic risk of DEHP was evaluated to be 3.912 × 10-5, and was 39 times higher than the limit set by the U.S. EPA.

Screening for Stockholm Convention persistent organic pollutants in the Bosna River (Bosnia and Herzogovina).

PubMed

Harman, Christopher; Grung, Merete; Djedjibegovic, Jasmina; Marjanovic, Aleksandra; Sober, Miroslav; Sinanovic, Kemo; Fjeld, Eirik; Rognerud, Sigurd; Ranneklev, Sissel Brit; Larssen, Thorjørn

2013-02-01

The Stockholm Convention, which aspires to manage persistent organic pollutants (POPs) at the international level, was recently ratified in Bosnia and Herzegovina (BiH). Despite this fact, there is in general a paucity of data regarding the levels of POPs in the environment in BiH. In the present study, screening for POPs was conducted in one of the country's major rivers, the Bosna. A two-pronged approach was applied using passive samplers to detect the freely dissolved and bioavailable concentrations in the water phase and sediment analysis to provide an integrated measure of historical contamination. At several places along the river, the concentrations of polycyclic aromatic hydrocarbons (PAH) were high and exhibited potential for both chronic and acute effects to biota. River water also showed elevated concentrations of PAH, up to 480 ng L(-1) near the city of Doboj, and diagnostic ratios suggested combustion sources for the contamination present in both types of sample. The levels of the other contaminants measured-polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers--were generally low in the water phase. However, PCBs and some OCPs were present in river sediments at levels which breach the international criteria and thus suggest potential for ecological damage. Additionally, the levels of heptachlor breached these criteria in many of the sites investigated. This study presents the first screening data for some of these Stockholm Convention relevant compounds in BiH and reveals both low concentrations of some chemical groups, but significant point sources and historic contamination for others.

A study of personal and area airborne asbestos concentrations during asbestos abatement: a statistical evaluation of fibre concentration data.

PubMed

Lange, J H; Lange, P R; Reinhard, T K; Thomulka, K W

1996-08-01

Data were collected and analysed on airborne concentrations of asbestos generated by abatement of different asbestos-containing materials using various removal practices. Airborne concentrations of asbestos are dramatically variable among the types of asbestos-containing material being abated. Abatement practices evaluated in this study were removal of boiler/pipe insulation in a crawl space, ceiling tile, transite, floor tile/mastic with traditional methods, and mastic removal with a high-efficiency particulate air filter blast track (shot-blast) machine. In general, abatement of boiler and pipe insulation produces the highest airborne fibre levels, while abatement of floor tile and mastic was observed to be the lowest. A comparison of matched personal and area samples was not significantly different, and exhibited a good correlation using regression analysis. After adjusting data for outliers, personal sample fibre concentrations were greater than area sample fibre concentrations. Statistical analysis and sample distribution of airborne asbestos concentrations appear to be best represented in a logarithmic form. Area sample fibre concentrations were shown in this study to have a larger variability than personal measurements. Evaluation of outliers in fibre concentration data and the ability of these values to skew sample populations is presented. The use of personal and area samples in determining exposure, selecting personal protective equipment and its historical relevance as related to future abatement projects is discussed.

Metallurgical Laboratory (MetLab) Treatability Study: An Analysis of Passive Soil Vapor Extraction Wells (PSVE) FY1999 Update

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

Riha, B.D.

1999-10-20

The results to date on the treatability study of the PSVE system at the MetLab of the Savannah River Site (SRS) indicate the technology is performing well. Well concentrations are decreasing and contour maps of the vadose zone soil gas plume show a decrease in the extent of the plume. In the 18 months of operation approximately 200 pounds of chlorinated organic contaminants have been removed by natural barometric pumping of wells fitted with BaroBall valves (low pressure check valves). The mass removal estimates are approximate since the flow rates are estimated, the concentration data is based on exponential fitsmore » of a limited data set, and the concentration data is normalized to the average CO2.The concentration values presented in this report should be taken as the general trend or order of magnitude of concentration until longer-term data is collected. These trends are of exponentially decreasing concentration showing the same characteristics as the concentration trends at the SRS Miscellaneous Chemical Basin after three years of PSVE (Riha et. al., 1999).« less

Effect of Dibutyl Phthalate on the Tolerance and Lipid Accumulation in the Green Microalgae Chlorella vulgaris.

PubMed

Duan, Kaili; Cui, Meng; Wu, Yanni; Huang, Xueyong; Xue, Ahui; Deng, Xunan; Luo, Liping

2018-06-16

In the present study, Chlorella vulgaris were cultured in the presence of the common plasticizer dibutyl phthalate (DBP) with different concentrations for 10 days. The cell density, DBP concentrations, neutral lipid concentrations, and lipid morphology in C. vulgaris were studied using optical microscopy, gas chromatography (GC), fluorescence spectrophotometry, and laser scanning confocal microscopy (LSCM). We observed that the neutral lipid contents and cell density of C. vulgaris were negatively influenced by DBP of high concentrations (50 and 100 mg/L), but significantly stimulated by DBP of low concentrations (5, 10, and 20 mg/L). Lipid bodies were destroyed into pieces by DBP of high concentrations (50 and 100 mg/L), but were slightly suppressed by DBP at low concentrations (5, 10, and 20 mg/L). Chlorella vulgaris treated with DBP (50 mg/L) for 2 days showed the highest removal efficiency (31.69%). The results suggested that C. vulgaris could be used in practice to remove DBP and has the potential of being oleaginous microalgae in DBP contaminated water.

Effects of the Deregulation on the Concentration of the Brazilian Air Transportation Industry

NASA Technical Reports Server (NTRS)

Guterres, Marcelo Xavier; Muller, Carlos

2003-01-01

This paper addresses the effects of the deregulation of the Brazilian air transportation industry in terms of the concentration of the market. We will show some metrics that are commonly used to study the concentration of the industry. This paper uses the Herfindhal- Hirschman Index. This index tends to zero in the competitive scenario, with a large number of small firms, and to one in case of a monopolistic scenario. The paper analyses the dynamics of the concentration of the Brazilian domestic air transportation market, in order to evaluate the effects of deregulation. We conclude that the Brazilian market presents oligopoly characteristics and aspects in its current structure that maintain the market concentrated in spite of the Deregulation measures adopted by the aeronautical authority. Keywords: Herfindhal-Hirschman Index, concentration, Deregulation

Correlates of Cortisol in Human Hair: Implications for Epidemiologic Studies on Health Effects of Chronic Stress

PubMed Central

Wosu, Adaeze C.; Valdimarsdóttir, Unnur; Shields, Alexandra E.; Williams, David R.; Williams, Michelle A.

2013-01-01

Assessment of cortisol concentrations in hair is one of the latest innovations for measuring long-term cortisol exposure. We performed a systematic review of correlates of cortisol in human hair to inform the design, analysis and interpretation of future epidemiologic studies. Relevant publications were identified through electronic searches on PubMed, WorldCat, and Web of Science using keywords, “cortisol” “hair” “confounders” “chronic” “stress” and “correlates.” Thirty-nine studies were included in this review. Notwithstanding scarce data and some inconsistencies, investigators have found hair cortisol concentrations to be associated with stress-related psychiatric symptoms and disorders (e.g., PTSD), medical conditions indicating chronic activation of the hypothalamic-pituitary-adrenal axis (e.g., Cushing´s syndrome) and other life situations associated with elevated risk of chronic stress (e.g., shiftwork). Results from some studies suggest that physical activity, adiposity, and substance abuse may be correlates of hair cortisol concentrations. In contrast to measures of short-term cortisol release (saliva, blood, and urine), cigarette smoking and use of oral contraceptives appear to not be associated with hair cortisol concentrations. Studies of pregnant women indicate increased hair cortisol concentrations across successive trimesters. The study of hair cortisol presents a unique opportunity to assess chronic alterations in cortisol concentrations in epidemiologic studies. PMID:24184029

Correlates of cortisol in human hair: implications for epidemiologic studies on health effects of chronic stress.

PubMed

Wosu, Adaeze C; Valdimarsdóttir, Unnur; Shields, Alexandra E; Williams, David R; Williams, Michelle A

2013-12-01

Assessment of cortisol concentrations in hair is one of the latest innovations for measuring long-term cortisol exposure. We performed a systematic review of correlates of cortisol in human hair to inform the design, analysis, and interpretation of future epidemiologic studies. Relevant publications were identified through electronic searches on PubMed, WorldCat, and Web of Science using keywords, "cortisol," "hair," "confounders," "chronic," "stress," and "correlates." Thirty-nine studies were included in this review. Notwithstanding scarce data and some inconsistencies, investigators have found hair cortisol concentrations to be associated with stress-related psychiatric symptoms and disorders (e.g., post-traumatic stress disorder), medical conditions indicating chronic activation of the hypothalamic-pituitary-adrenal axis (e.g., Cushing's syndrome), and other life situations associated with elevated risk of chronic stress (e.g., shiftwork). Results from some studies suggest that physical activity, adiposity, and substance abuse may be correlates of hair cortisol concentrations. In contrast to measures of short-term cortisol release (saliva, blood, and urine), cigarette smoking and use of oral contraceptives appear not to be associated with hair cortisol concentrations. Studies of pregnant women indicate increased hair cortisol concentrations across successive trimesters. The study of hair cortisol presents a unique opportunity to assess chronic alterations in cortisol concentrations in epidemiologic studies. Copyright © 2013 Elsevier Inc. All rights reserved.

Permeability Evaluation Through Chitosan Membranes Using Taguchi Design

PubMed Central

Sharma, Vipin; Marwaha, Rakesh Kumar; Dureja, Harish

2010-01-01

In the present study, chitosan membranes capable of imitating permeation characteristics of diclofenac diethylamine across animal skin were prepared using cast drying method. The effect of concentration of chitosan, concentration of cross-linking agent (NaTPP), crosslinking time was studied using Taguchi design. Taguchi design ranked concentration of chitosan as the most important factor influencing the permeation parameters of diclofenac diethylamine. The flux of the diclofenac diethylamine solution through optimized chitosan membrane (T9) was found to be comparable to that obtained across rat skin. The mathematical model developed using multilinear regression analysis can be used to formulate chitosan membranes that can mimic the desired permeation characteristics. The developed chitosan membranes can be utilized as a substitute to animal skin for in vitro permeation studies. PMID:21179329

Permeability evaluation through chitosan membranes using taguchi design.

PubMed

Sharma, Vipin; Marwaha, Rakesh Kumar; Dureja, Harish

2010-01-01

In the present study, chitosan membranes capable of imitating permeation characteristics of diclofenac diethylamine across animal skin were prepared using cast drying method. The effect of concentration of chitosan, concentration of cross-linking agent (NaTPP), crosslinking time was studied using Taguchi design. Taguchi design ranked concentration of chitosan as the most important factor influencing the permeation parameters of diclofenac diethylamine. The flux of the diclofenac diethylamine solution through optimized chitosan membrane (T9) was found to be comparable to that obtained across rat skin. The mathematical model developed using multilinear regression analysis can be used to formulate chitosan membranes that can mimic the desired permeation characteristics. The developed chitosan membranes can be utilized as a substitute to animal skin for in vitro permeation studies.

[Clinical presentation of different severities of hemorrhagic fever with renal syndrome: how to recognise it].

PubMed

Lausević, Mirjana; Lausević, Zeljko; Stojimirović, Biljana

2012-07-01

Besides viral serotype, HLA haplotype and cytokine genes polymorphism are associated with clinical presentation of hemorrhagic fever with renal syndrome. Since these analyses are unavailable in routine clinical practice, the aim of this study was to assess clinical, laboratory and radiographic findings associated with clinical presentation of disease severity. A total of 30 patients (27 men and 3 women), average age 40 +/- 14.9 years, treated for hemorrhagic fever with renal syndrome from January 1, 1999 to December 31, 2009 in Clinical Center of Serbia, were included in the study. Nine patients (30%) had mild, 14 (46.7%) moderate and 7 (23.3%) severe form of the disease; 24 (800%) recovered, 6 (20%) died in the acute phase of the illness, and 19 patients (63.3%) required hemodialysis. The average titer of antiviral antibodies in patients infected with Belgrade serotype virus were significantly higher in those with severe clinical presentation. Hypotension, anuria, macrohaematuria, pulmonary infiltration, pleural effusion, hepatomegalia and positive meningeal signs were more frequent in the patients with severe form of the disease. Statistically significant differences between groups with mild, moderate and severe clinical picture were found in serum total protein, albumin, calcium, glutamate pyruvate and glutamate oxaloacetate transaminase on admittance; serum creatinine and phosphorus concentration on day 14 and day 21; serum sodium and calciums on day 14; hemoglobine concentration on day 21. A statistically significant correlation was found between clinical presentation of the disease severity and platelet count, white blood cell count, hemoglobine concentration, serum calcium and serum transaminases on admittance. Multivariate analysis identified variables' combinations associated with clinical presentation of the disease. Our study confirmed that we can distinguish patients who will manifest different severities of the disease on the basis of careful consideration of laboratory and clinical findings on admission.

Concentrated energy addition for active drag reduction in hypersonic flow regime

NASA Astrophysics Data System (ADS)

Ashwin Ganesh, M.; John, Bibin

2018-01-01

Numerical optimization of hypersonic drag reduction technique based on concentrated energy addition is presented in this study. A reduction in wave drag is realized through concentrated energy addition in the hypersonic flowfield upstream of the blunt body. For the exhaustive optimization presented in this study, an in-house high precision inviscid flow solver has been developed. Studies focused on the identification of "optimum energy addition location" have revealed the existence of multiple minimum drag points. The wave drag coefficient is observed to drop from 0.85 to 0.45 when 50 Watts of energy is added to an energy bubble of 1 mm radius located at 74.7 mm upstream of the stagnation point. A direct proportionality has been identified between energy bubble size and wave drag coefficient. Dependence of drag coefficient on the upstream added energy magnitude is also revealed. Of the observed multiple minimum drag points, the energy deposition point (EDP) that offers minimum wave drag just after a sharp drop in drag is proposed as the most optimum energy addition location.

Climate change impacts on faecal indicator and waterborne pathogen concentrations and disease

NASA Astrophysics Data System (ADS)

Hofstra, Nynke; Vermeulen, Lucie C.; Wondmagegn, Berhanu Y.

2013-04-01

Changes in temperature and precipitation patterns may impact on the concentrations of the faecal indicator E. coli and waterborne pathogens, such as Cryptosporidium, in the surface water, and consequently - through drinking water, recreational water or consumption of irrigated vegetables - on the risk of waterborne disease. Although an increased temperature would generally increase the decline of pathogens and therefore decrease the surface water concentrations, increased precipitation and an increased incidence of extreme precipitation may increase surface water concentrations through increased (sub-)surface runoff and an increased risk of sewer overflows. And while the diluting effect of increased precipitation decreases the surface water concentration, decreased precipitation increases the percentage of sewage in the surface water and therefore increases the concentration. Moreover, (extreme) precipitation after drought may also increase the concentration. Changes in behaviour, such as increased recreation and irrigation with higher temperatures may impact on the disease risk. What the balance is between these positive and negative impacts of climate change on faecal indicator and waterborne pathogen concentrations and disease is not well known yet. A lack of available statistical or process-based models and suitable scenarios prevents quantitative analyses. We will present two examples of recent studies that aim to assess the impact of climate change on faecal indicator concentrations and waterborne disease. The first is a study on the relationship between climate variables and E. coli concentrations in the water of river systems in the Netherlands for the period 1985 - 2010. This study shows that each of the variables water temperature (negatively), precipitation and discharge (both positively) are significantly correlated with E. coli concentrations for most measurement locations. We will also present a linear regression model, including all of these variables. In the second example we assess the relationship between the weather variables precipitation and minimum and maximum temperature and the number of diarrhoeal cases in Ethiopia. We have digitised data from the Ethiopian health service and hospitals on the number of diarrhoeal cases for the period 2005 - 2010 and used meteorological data from their weather service. Very strong correlations can be found between the monthly weather variables and the number of diarrhoeal cases and a linear regression model including all variables explains a large part of the variability of the data. The studies indicate that climate change may increase the waterborne pathogen concentration in surface water and disease risk and should therefore not be ignored as a threat to microbial water quality.

Mycobiota and concentration of ochratoxin A in concentrated poultry feed from Venezuela.

PubMed

Figueroa, S; Centeno, S; Calvo, M A; Rengel, A; Adelantado, C

2009-04-01

The main objective of this study was to evaluate the frequency distribution of mycobiota and the concentration of Ochratoxin A (OTA) in 50 samples from one company of commercial brand poultry feed produced in Venezuela. The concentration of OTA in the samples analyzed was determined using the competitive ELISA method. The most frequently isolated genera of moulds were Aspergillus (36%) and Penicillium (20%). Of these genera, the most frequently isolated species were Aspergillus flavus, Aspergillus terreus and Penicillium citrinum. Ochratoxigenic species such as Eurotium herbariorum, Aspergillus niger, Aspergillus ochraceus and Aspergillus glaucus, were also found with lower frequency. Rhodotorula mucilaginosa was the only yeast isolated. 94% of the samples presented contamination by OTA in a range between 2.558 and 31.978 microg kg(-1) feed and 42% of them presented OTA levels from 10 up to 20 microg kg(-1). The findings of this investigation show that 84% of the samples of concentrated feed for meat poultry surpass the maximum permitted limit for OTA of 5 microg kg(-1), established in the majority of countries in which regulations are placed.

Non-destructive pollution exposure assessment in the European hedgehog (Erinaceus europaeus): II. Hair and spines as indicators of endogenous metal and As concentrations.

PubMed

D'Havé, Helga; Scheirs, Jan; Mubiana, Valentine Kayawe; Verhagen, Ron; Blust, Ronny; De Coen, Wim

2006-08-01

The role of hair and spines of the European hedgehog as non-destructive monitoring tools of metal (Ag, Al, Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn) and As pollution in terrestrial ecosystems was investigated. Our results showed that mean pollution levels of a random sample of hedgehogs in Flanders are low to moderate. Yet, individual hedgehogs may be at risk for metal toxicity. Tissue distribution analyses (hair, spines, liver, kidney, muscle and fat tissue) indicated that metals and As may reach considerable concentrations in external tissues, such as hair and spines. Positive relationships were observed between concentrations in hair and those in liver, kidney and muscle for Al, Co, Cr, Cu, and Pb (0.43 < r < 0.85). Spine concentrations were positively related to liver, kidney and muscle concentrations for Cd, Co, Cr, Cu and Pb (0.37 < r < 0.62). Hair Ag, As, Fe and Zn and spine Ag, Al, As and Fe were related to metal concentrations in one or two of the investigated internal tissues (0.31 < r < 0.45). The regression models presented here may be used to predict metal and As concentrations in internal tissues of hedgehogs when concentrations in hair or spines are available. The present study demonstrated the possibility of using hair and spines for non-destructive monitoring of metal and As pollution in hedgehogs.

Concentrations of organochlorine pesticides and 2,4,6-trichloroanisole in cork bark.

PubMed

Olivella, M Àngels; Caixach, Josep; Planas, Carles; Oliveras, Anna; Jové, Patrícia

2012-02-01

Organochlorine pesticides are persistent lipophilic organic pollutants and tend to accumulate in growing plants. During growth, cork is in contact with the open air for long periods (9-12 years). Owing to the previous widespread use of organochlorine pesticides and their high persistence in the environment, there is a risk that residues of such pesticides may be present in cork. In this study, the concentrations of 14 organochlorine pesticides-all of which are indicators of environmental pollution-were analyzed in cork bark samples from three regions in Spain and one in Portugal. In addition, the concentrations of 2,4,6-trichlorophenol (TCP) and 2,4,6-trichloroanisole (TCA) were also analyzed. Our results show only very low concentrations of lindane, γ-HCH (<2.6 ng g(-1)) and its byproducts α-HCH (<3.5 ng g(-1)) and β-HCH (<0.6 ng g(-1)). Among the DDT and its metabolites, only two were found: p,p'-DDT was found in a cork sample from Extremadura (0.1 ng g(-1)) and p,p'-DDE was present at a maximum concentration of 2.9 ng g(-1) in a cork sample from Castile-La Mancha. However, all concentrations were well below the legal limit established by Regulation (EC) No. 396/2005 (10 ng g(-1) in foodstuffs). We can conclude, therefore, that the cork samples we studied complied with food safety standards. Copyright © 2011 Elsevier Ltd. All rights reserved.

Measurement of salivary aldosterone: validation by low-dose ACTH test and gender differences.

PubMed

Hlavacova, N; Kerlik, J; Radikova, Z; Izakova, L; Jezova, D

2013-10-01

The aim of the present study was to validate the feasibility of measurement of the salivary aldosterone concentrations by performing a low-dose adrenocorticotropic hormone (ACTH) test. Moreover, the presence of gender differences in salivary aldosterone, considering the phase of the menstrual cycle in women, was verified. The sample consisted of 107 volunteers (60 men, 21 women in the follicular phase and 26 women in the luteal phase of the menstrual cycle). Saliva samples were taken by the subjects themselves around 08:00 AM, at least 60 min after awaking. A separate group of female subjects in the follicular phase underwent low-dose ACTH test (1µg synthetic ACTH i.v.) performed at 08:30 AM with blood and saliva sampling every 30 min for 120 min. Modification of the commercial aldosterone radioimmunoassay methodology for the salivary aldosterone measurement was performed. Salivary aldosterone concentrations rose in response to low-dose ACTH test and positive significant correlation in aldosterone concentrations between plasma and saliva was found. The results showed that women in the luteal phase of the menstrual cycle exhibited significantly higher morning concentrations in salivary aldosterone than men and women in the follicular phase. This study clearly demonstrates suitability of measurement of salivary aldosterone concentrations in the low-dose ACTH test and reveals gender differences in salivary aldosterone levels. The results show high validity of the presented method and its usefulness for assessment of the aldosterone concentrations in saliva.

The effects of meteorological factors on airborne fungal spore concentration in two areas differing in urbanisation level

NASA Astrophysics Data System (ADS)

Oliveira, M.; Ribeiro, H.; Delgado, J. L.; Abreu, I.

2009-01-01

Although fungal spores are an ever-present component of the atmosphere throughout the year, their concentration oscillates widely. This work aims to establish correlations between fungal spore concentrations in Porto and Amares and meteorological data. The seasonal distribution of fungal spores was studied continuously (2005-2007) using volumetric spore traps. To determine the effect of meteorological factors (temperature, relative humidity and rainfall) on spore concentration, the Spearman rank correlation test was used. In both locations, the most abundant fungal spores were Cladosporium, Agaricus, Agrocybe, Alternaria and Aspergillus/Penicillium, the highest concentrations being found during summer and autumn. In the present study, with the exception of Coprinus and Pleospora, spore concentrations were higher in the rural area than in the urban location. Among the selected spore types, spring-autumn spores ( Coprinus, Didymella, Leptosphaeria and Pleospora) exhibited negative correlations with temperature and positive correlations both with relative humidity and rainfall level. On the contrary, late spring-early summer (Smuts) and summer spores ( Alternaria, Cladosporium, Epicoccum, Ganoderma, Stemphylium and Ustilago) exhibited positive correlations with temperature and negative correlations both with relative humidity and rainfall level. Rust, a frequent spore type during summer, had a positive correlation with temperature. Aspergillus/Penicillium, showed no correlation with the meteorological factors analysed. This knowledge can be useful for agriculture, allowing more efficient and reliable application of pesticides, and for human health, by improving the diagnosis and treatment of respiratory allergic disease.

A perfusion study of the handling of urea and urea analogues by the gills of the dogfish shark (Squalus acanthias).

PubMed

Wood, Chris M; Liew, Hon Jung; De Boeck, Gudrun; Walsh, Patrick J

2013-01-01

The branchial mechanism of urea retention in elasmobranchs was investigated using an in vitro isolated-perfused head preparation, as well as in vivo samples, in the spiny dogfish shark. Both in vivo and in control saline perfusions containing 350 mmol L(-1) urea, calculated intracellular urea concentrations in gill epithelial cells were close to extracellular concentrations. Urea efflux to the external water fell only non-significantly, and calculated gill intracellular urea concentration did not change when perfusate urea concentration was reduced from 350 to 175 mmol L(-1) with osmotic compensation by 175 mmol L(-1) mannitol. However, when the urea analogues thiourea or acetamide were present in the perfusate at concentrations equimolar (175 mmol L(-1)) to those of urea (175 mmol L(-1)), urea efflux rates were increased 4-fold and 6.5-fold respectively, and calculated gill intracellular urea concentrations were depressed by about 55%. Analogue efflux rates were similar to urea efflux rates. Previous studies have argued that either the basolateral or apical membranes provided the limiting permeability barrier, and/or that a back-transporter on the basolateral membranes of gill cells is responsible for urea retention. The present results provide new evidence that the apical membrane is the limiting factor in maintaining gill urea impermeability, and raise the prospect that a urea back-transporter, which can be competitively inhibited by thiourea and acetamide, operates at the apical membrane.

Buffer-free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions: from protein buffer capacity prediction to bioprocess applications.

PubMed

Bahrenburg, Sven; Karow, Anne R; Garidel, Patrick

2015-04-01

Protein therapeutics, including monoclonal antibodies (mAbs), have significant buffering capacity, particularly at concentrations>50 mg/mL. This report addresses pH-related issues critical to adoption of self-buffered monoclonal antibody formulations. We evaluated solution conditions with protein concentrations ranging from 50 to 250 mg/mL. Samples were both buffer-free and conventionally buffered with citrate. Samples were non-isotonic or adjusted for isotonicity with NaCl or trehalose. Studies included accelerated temperature stability tests, shaking stability studies, and pH changes in infusion media as protein concentrate is added. We present averaged buffering slopes of capacity that can be applied to any mAb and present a general method for calculating buffering capacity of buffer-free, highly concentrated antibody liquid formulations. In temperature stability tests, neither buffer-free nor conventionally buffered solution conditions showed significant pH changes. Conventionally buffered solutions showed significantly higher opalescence than buffer-free ones. In general, buffer-free solution conditions showed less aggregation than conventionally buffered solutions. Shaking stability tests showed no differences between buffer-free and conventionally buffered solutions. "In-use" preparation experiments showed that pH in infusion bag medium can rapidly approximate that of self-buffered protein concentrate as concentrate is added. In summary, the buffer capacity of proteins can be predicted and buffer-free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of rainfall events on the occurrence and detection efficiency of viruses in river water impacted by combined sewer overflows.

PubMed

Hata, Akihiko; Katayama, Hiroyuki; Kojima, Keisuke; Sano, Shoichi; Kasuga, Ikuro; Kitajima, Masaaki; Furumai, Hiroaki

2014-01-15

Rainfall events can introduce large amount of microbial contaminants including human enteric viruses into surface water by intermittent discharges from combined sewer overflows (CSOs). The present study aimed to investigate the effect of rainfall events on viral loads in surface waters impacted by CSO and the reliability of molecular methods for detection of enteric viruses. The reliability of virus detection in the samples was assessed by using process controls for virus concentration, nucleic acid extraction and reverse transcription (RT)-quantitative PCR (qPCR) steps, which allowed accurate estimation of virus detection efficiencies. Recovery efficiencies of poliovirus in river water samples collected during rainfall events (<10%) were lower than those during dry weather conditions (>10%). The log10-transformed virus concentration efficiency was negatively correlated with suspended solid concentration (r(2)=0.86) that increased significantly during rainfall events. Efficiencies of DNA extraction and qPCR steps determined with adenovirus type 5 and a primer sharing control, respectively, were lower in dry weather. However, no clear relationship was observed between organic water quality parameters and efficiencies of these two steps. Observed concentrations of indigenous enteric adenoviruses, GII-noroviruses, enteroviruses, and Aichi viruses increased during rainfall events even though the virus concentration efficiency was presumed to be lower than in dry weather. The present study highlights the importance of using appropriate process controls to evaluate accurately the concentration of water borne enteric viruses in natural waters impacted by wastewater discharge, stormwater, and CSOs. © 2013.

The surface of 1-euro coins studied by X-ray photoelectron spectroscopy

NASA Astrophysics Data System (ADS)

Gou, F.; Gleeson, M. A.; Villette, J.; Kleyn, S. E. F.; Kleyn, A. W.

2004-03-01

The two alloy surfaces (pill and ring) that are present on 1-euro coins have been studied by X-ray photoelectron spectroscopy (XPS). Comparison is made between coins from general circulation and coin surfaces that have been subjected to a variety of cleaning and oxidation treatments. The concentrations and possible oxidation states of the metals (nickel, copper and zinc) at the surface were derived from analysis of the 2p 3/2 core levels. The surface atomic ratios measured for the pill and the ring parts of the euro coins were compared to the official bulk ratios. This study shows a clear nickel enrichment of both pill and ring surfaces. Nickel at surface seems to be present mainly in hydroxide form although the chloride form cannot be excluded. A small concentration of zinc was present on the surface of the pill, even though it is not present in the bulk alloy. Evidence of both nickel and zinc surface enrichment is observed for the ring. No surface enrichment is observed for the atomically clean or oxidized alloy surfaces over a 60-h time scale.

Mutagenic potential assessment associated with human exposure to natural radioactivity.

PubMed

Marcon, Alexandre Endres; Navoni, Julio Alejandro; de Oliveira Galvão, Marcos Felipe; Garcia, Anuska Conde Fagundes Soares; do Amaral, Viviane Souza; Petta, Reinaldo Antônio; Campos, Thomas Ferreira da Costa; Panosso, Renata; Quinelato, Antônio Luiz; de Medeiros, Sílvia Regina Batistuzzo

2017-01-01

Lucrécia city, known to harbor a high cancer rate, is located in a semiarid region characterized by the presence of mineral reservoirs, facing a high exposure to metal and natural radioactivity. The present study aimed to assess the environmental scenario at a semiarid region located in Northeastern Brazil. Metal concentration, alpha and beta radiation, and cyanobacteria content in tap water along with indoor radon and gamma emitters (U, K and Th) concentrations were measured. In addition, mutagenic and nuclear instability effects were assessed using buccal micronucleus cytome assay. The study included five samplings corresponding to a period between 2007 and 2009. Drinking water from Lucrécia city presented levels of Mn, Ni and Cr along with cyanobacteria in concentrations one to four times higher than regulatory guidelines considered. Furthermore, high levels of all the tested radionuclides were found. A high percentage of the houses included in this study presented indoor radon concentrations over 100 Bq m -3 . The mean annual effective dose from Lucrécia houses was six times higher than observed in a control region. The levels of exposure in most of the Lucrécia houses were classified as middle to high. A significant mutagenic effect, represented as an increase of micronuclei (MN) frequency and nuclear abnormalities as nuclear buds (NB), binucleated cells (BN), and pyknotic cells (PYC) were found. The results obtained highlight the role of high background radioactivity on the observed mutagenic effect and could help to explain the exacerbated cancer rate reported in this locality. Copyright © 2016. Published by Elsevier Ltd.

Agmatine protects Müller cells from high-concentration glucose-induced cell damage via N-methyl-D-aspartic acid receptor inhibition

PubMed Central

HAN, NING; YU, LI; SONG, ZHIDU; LUO, LIFU; WU, YAZHEN

2015-01-01

Neural injury is associated with the development of diabetic retinopathy. Müller cells provide structural and metabolic support for retinal neurons. High glucose concentrations are known to induce Müller cell activity. Agmatine is an endogenous polyamine, which is enzymatically formed in the mammalian brain and has exhibited neuroprotective effects in a number of experimental models. The aims of the present study were to investigate whether agmatine protects Müller cells from glucose-induced damage and to explore the mechanisms underlying this process. Lactate dehydrogenase activity and tumor necrosis factor-α mRNA expression were significantly reduced in Müller cells exposed to a high glucose concentration, following agmatine treatment, compared with cells not treated with agmatine. In addition, agmatine treatment inhibited glucose-induced Müller cell apoptosis, which was associated with the regulation of Bax and Bcl-2 expression. Agmatine treatment suppressed glucose-induced phosphorylation of mitogen-activated protein kinase (MAPK) protein in Müller cells. The present study demonstrated that the protective effects of agmatine on Müller cells were inhibited by N-methyl-D-aspartic acid (NMDA). The results of the present study suggested that agmatine treatment protects Müller cells from high-concentration glucose-induced cell damage. The underlying mechanisms may relate to the anti-inflammatory and antiapoptotic effects of agmatine, as well as to the inhibition of the MAPK pathway, via NMDA receptor suppression. Agmatine may be of use in the development of novel therapeutic approaches for patients with diabetic retinopathy. PMID:25816073

Agmatine protects Müller cells from high-concentration glucose-induced cell damage via N-methyl-D-aspartic acid receptor inhibition.

PubMed

Han, Ning; Yu, Li; Song, Zhidu; Luo, Lifu; Wu, Yazhen

2015-07-01

Neural injury is associated with the development of diabetic retinopathy. Müller cells provide structural and metabolic support for retinal neurons. High glucose concentrations are known to induce Müller cell activity. Agmatine is an endogenous polyamine, which is enzymatically formed in the mammalian brain and has exhibited neuroprotective effects in a number of experimental models. The aims of the present study were to investigate whether agmatine protects Müller cells from glucose-induced damage and to explore the mechanisms underlying this process. Lactate dehydrogenase activity and tumor necrosis factor-α mRNA expression were significantly reduced in Müller cells exposed to a high glucose concentration, following agmatine treatment, compared with cells not treated with agmatine. In addition, agmatine treatment inhibited glucose-induced Müller cell apoptosis, which was associated with the regulation of Bax and Bcl-2 expression. Agmatine treatment suppressed glucose-induced phosphorylation of mitogen-activated protein kinase (MAPK) protein in Müller cells. The present study demonstrated that the protective effects of agmatine on Müller cells were inhibited by N-methyl-D-aspartic acid (NMDA). The results of the present study suggested that agmatine treatment protects Müller cells from high-concentration glucose-induced cell damage. The underlying mechanisms may relate to the anti-inflammatory and antiapoptotic effects of agmatine, as well as to the inhibition of the MAPK pathway, via NMDA receptor suppression. Agmatine may be of use in the development of novel therapeutic approaches for patients with diabetic retinopathy.

Water-quality data from lakes and streams in the Grand Portage Reservation, Minnesota, 1997-98

USGS Publications Warehouse

Winterstein, Thomas A.

1999-01-01

The purpose of this report is to present the data collected by the USGS from the study during 1997-98. Water-quality data include temperature, pH, specific conductance, dissolved oxygen, alkalinity, and concentrations of major ions, nutrients, and trace metals. Lake sediment data include concentrations of trace metals and selected organic compounds.

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

Rutherford, L.A.; Matthews, S.L.

A study was conducted to determine historical atmospheric mercury deposition patterns in the Maritime Provinces. Investigators measured mercury concentrations in peat cores from five ombrotrophic bogs in Kejimkujik, Fundy, Kouchibougouac, and Cape Breton Highlands national parks and in East Baltic Bog, Prince Edward Island. Results presented and discussed include deposition rates calculated using lead-210 date estimates, temporal trends in mercury concentrations, and spatial patterns of mercury deposition.

Complementary construction of ideal nonimaging concentrators and its applications.

PubMed

Gordon, J M

1996-10-01

A construction principle for ideal nonimaging concentrators based on the complementary edge rays outside the nominal field of view is presented, with illustrations for the trumpet, compound parabolic concentrator, and compound hyperbolic concentrator. A simple string construction for the trumpet concentrator is shown to follow from this observation-the trumpet having been the one ideal concentrator for which no string-construction method had previously been noted. An application of these observations for solar concentrator design when nonisothermal receivers are advantageous is also presented.

Influence of alkaline hydrogen peroxide pre-hydrolysis on the isolation of microcrystalline cellulose from oil palm fronds.

PubMed

Owolabi, Abdulwahab F; Haafiz, M K Mohamad; Hossain, Md Sohrab; Hussin, M Hazwan; Fazita, M R Nurul

2017-02-01

In the present study, microcrystalline cellulose (MCC) was isolated from oil palm fronds (OPF) using chemo-mechanical process. Wherein, alkaline hydrogen peroxide (AHP) was utilized to extract OPF fibre at different AHP concentrations. The OPF pulp fibre was then bleached with acidified sodium chlorite solution followed by the acid hydrolysis using hydrochloric acid. Several analytical methods were conducted to determine the influence of AHP concentration on thermal properties, morphological properties, microscopic and crystalline behaviour of isolated MCC. Results showed that the MCC extracted from OPF fibres had fibre diameters of 7.55-9.11nm. X-ray diffraction (XRD) analyses revealed that the obtained microcrystalline fibre had both celluloses I and cellulose II polymorphs structure, depending on the AHP concentrations. The Fourier transmission infrared (FTIR) analyses showed that the AHP pre-hydrolysis was successfully removed hemicelluloses and lignin from the OPF fibre. The crystallinity of the MCC was increased with the AHP concentrations. The degradation temperature of MCC was about 300°C. The finding of the present study showed that pre-treatment process potentially influenced the quality of the isolation of MCC from oil palm fronds. Copyright © 2016 Elsevier B.V. All rights reserved.

Leukotriene-B4 concentrations in exhaled breath condensate and lung function after thirty minutes of breathing technically dried compressed air.

PubMed

Neubauer, Birger; Struck, Niclas; Mutzbauer, Till S; Schotte, Ulrich; Langfeldt, Norbert; Tetzlaff, Kay

2002-01-01

In previous studies it had been shown that leukotriene-B4 [LTB4] concentrations in the exhaled breath mirror the inflammatory activity of the airways if the respiratory tract has been exposed to occupational hazards. In diving the respiratory tract is exposed to cold and dry air and the nasopharynx, as the site of breathing-gas warming and humidification, is bypassed. The aim of the present study was to obtain LTB4-concentrations in the exhaled breath and spirometric data of 17 healthy subjects before and after thirty minutes of technically dried air breathing at normobar ambient pressure. The exhaled breath was collected non-invasively, via a permanently cooled expiration tube. The condensate was measured by a standard enzyme immunoassay for LTB4. Lung function values (FVC, FEV1, MEF 25, MEF 50) were simultaneously obtained by spirometry. The measured pre- and post-exposure LTB4- concentrations as well as the lung function values were in the normal range. The present data gave no evidence for any inflammatory activity in the subjects' airways after thirty minutes breathing technically dried air.

Effect of lead nitrate on the liver of the cichlid fish (Oreochromis niloticus): a light microscope study.

PubMed

Khidr, Bothaina M; Mekkawy, Imam A A; Harabawy, Ahmed S A; Ohaida, Abdel Salam M I

2012-09-15

The adverse impacts of heavy metals on fish liver were evident with great variability among organs and species. The present study deals with the histological changes of the hepatocytes of the Nile tilapia, Oreochromis niloticus, following exposure to 2.5, 5, 10 ppm of lead nitrate for 1, 2, 3, 4 weeks. The present results revealed that lead nitrate exerts some histological effects on the hepatic tissue after exposure to the first concentration in the form of dilatation and congestion of the blood vessels, vacuolation of hepatic cells, proliferation of connective tissue and hepatic necrosis. Leucocyte aggregation-mostly lymphatic in nature-was seen infiltrating hepatic tissue. These alterations became more pronounced in liver of fishes exposed to second concentrations indicating more progressive signs of necrosis. The presence of eosinophilic oedematous areas surrounding some blood vessels was also observed. Finally, at the third concentration, in addition to the above alterations, melanomacrophages, which store lipofuscin at the site of necrosis, were observed. These histological results imply that the fish liver may serve as a target organ for the toxicity of sublethal concentrations of lead nitrate.

Pollution Problem in River Kabul: Accumulation Estimates of Heavy Metals in Native Fish Species.

PubMed

Ahmad, Habib; Yousafzai, Ali Muhammad; Siraj, Muhammad; Ahmad, Rashid; Ahmad, Israr; Nadeem, Muhammad Shahid; Ahmad, Waqar; Akbar, Nazia; Muhammad, Khushi

2015-01-01

The contamination of aquatic systems with heavy metals is affecting the fish population and hence results in a decline of productivity rate. River Kabul is a transcountry river originating at Paghman province in Afghanistan and inters in Khyber Pakhtunkhwa province of Pakistan and it is the major source of irrigation and more than 54 fish species have been reported in the river. Present study aimed at the estimation of heavy metals load in the fish living in River Kabul. Heavy metals including chromium, nickel, copper, zinc, cadmium, and lead were determined through atomic absorption spectrophotometer after tissue digestion by adopting standard procedures. Concentrations of these metals were recorded in muscles and liver of five native fish species, namely, Wallago attu, Aorichthys seenghala, Cyprinus carpio, Labeo dyocheilus, and Ompok bimaculatus. The concentrations of chromium, nickel, copper, zinc, and lead were higher in both of the tissues, whereas the concentration of cadmium was comparatively low. However, the concentration of metals was exceeding the RDA (Recommended Dietary Allowance of USA) limits. Hence, continuous fish consumption may create health problems for the consumers. The results of the present study are alarming and suggest implementing environmental laws and initiation of a biomonitoring program of the river.

Modelling of the batch biosorption system: study on exchange of protons with cell wall-bound mineral ions.

PubMed

Mishra, Vishal

2015-01-01

The interchange of the protons with the cell wall-bound calcium and magnesium ions at the interface of solution/bacterial cell surface in the biosorption system at various concentrations of protons has been studied in the present work. A mathematical model for establishing the correlation between concentration of protons and active sites was developed and optimized. The sporadic limited residence time reactor was used to titrate the calcium and magnesium ions at the individual data point. The accuracy of the proposed mathematical model was estimated using error functions such as nonlinear regression, adjusted nonlinear regression coefficient, the chi-square test, P-test and F-test. The values of the chi-square test (0.042-0.017), P-test (<0.001-0.04), sum of square errors (0.061-0.016), root mean square error (0.01-0.04) and F-test (2.22-19.92) reported in the present research indicated the suitability of the model over a wide range of proton concentrations. The zeta potential of the bacterium surface at various concentrations of protons was observed to validate the denaturation of active sites.

Soot Formation in Laminar Acetylene/Air Diffusion Flames at Atmospheric Pressure. Appendix C

NASA Technical Reports Server (NTRS)

Xu, F.; Faeth, G. M.; Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

2000-01-01

The flame structure and soot-formation (soot nucleation and growth) properties of axisymmetric laminar coflowing jet diffusion flames were studied experimentally. Test conditions involved acetylene-nitrogen jets burning in coflowing air at atmospheric pressure. Measurements were limited to the axes of the flames and included soot concentrations, soot temperatures, soot structure, major gas species concentrations, radical species (H, OH, and O) concentrations, and gas velocities. The results show that as distance increases along the axes of the flames, detectable soot formation begins when significant H concentrations are present, and ends when acetylene concentrations become small. Species potentially associated with soot oxidation-O2, CO2, H2O, O, and OH-are present throughout the soot-formation region so that soot formation and oxidation proceed at the same time. Strong rates of soot growth compared to soot nucleation early in the soot-formation process, combined with increased rates of soot nucleation and oxidation as soot formation proceeds, causes primary soot particle diameters to reach a maximum relatively early in the soot-formation process. Aggregation of primary soot particles proceeds, however, until the final stages of soot oxidation. Present measurements of soot growth (corrected for soot oxidation) in laminar diffusion flames were consistent with earlier measurements of soot growth in laminar premixed flames and exhibited encouraging agreement with existing hydrogen-abstraction/carbon-addition (HACA) soot growth mechanisms in the literature that were developed based on measurements within laminar premixed flames. Measured primary soot particle nucleation rates in the present laminar diffusion flames also were consistent with corresponding rates measured in laminar premixed flames and yielded a crude correlation in terms of acetylene and H concentrations and the temperature.

Soot Formation in Laminar Acetylene/Air Diffusion Flames at Atmospheric Pressure. Appendix H

NASA Technical Reports Server (NTRS)

Xu, F.; Faeth, G. M.; Yuan, Z.-G. (Technical Monitor); Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

2001-01-01

The flame structure and soot-formation (soot nucleation and growth) properties of axisymmetric laminar coflowing jet diffusion flames were studied experimentally. Test conditions involved acetylene-nitrogen jets burning in coflowing air at atmospheric pressure. Measurements were limited to the axes of the flames and included soot concentrations, soot temperatures, soot structure, major gas species concentrations, radical species (H, OH, and O) concentrations, and gas velocities. The results show that as distance increases along the axes of the flames, detectable soot formation begins when significant H concentrations are present, and ends when acetylene concentrations become small. Species potentially associated with soot oxidation-O2, CO2, H2O, O, and OH-are present throughout the soot-formation region so that soot formation and oxidation proceed at the same time. Strong rates of soot growth compared to soot nucleation early in the soot-formation process, combined with increased rates of soot nucleation and oxidation as soot formation proceeds, causes primary soot particle diameters to reach a maximum relatively early in the soot-formation process. Aggregation of primary soot particles proceeds, however, until the final stages of soot oxidation. Present measurements of soot growth (corrected for soot oxidation) in laminar diffusion flames were consistent with earlier measurements of soot growth in laminar premixed flames and exhibited encouraging agreement with existing hydrogen-abstraction/carbon-addition (HACA) soot growth mechanisms in the literature that were developed based on measurements within laminar premixed flames. Measured primary soot particle nucleation rates in the present laminar diffusion flames also were consistent with corresponding rates measured in laminar premixed flames and yielded a crude correlation in terms of acetylene and H concentrations and the temperature.

Soot Formation in Laminar Acetylene/Air Diffusion Flames at Atmospheric Pressure. Appendix J

NASA Technical Reports Server (NTRS)

Xu, F.; Faeth, G. M.; Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

2001-01-01

The flame structure and soot-formation (soot nucleation and growth) properties of axisymmetric laminar coflowing jet diffusion flames were studied experimentally. Test conditions involved acetylene-nitrogen jets burning in coflowing air at atmospheric pressure. Measurements were limited to the axes of the flames and included soot concentrations, soot temperatures, soot structure, major gas species concentrations, radical species (H, OH, and O) concentrations, and gas velocities. The results show that as distance increases along the axes of the flames, detectable soot formation begins when significant H concentrations are present, and ends when acetylene concentrations become small. Species potentially associated with soot oxidation--O2, CO2, H2O, O, and OH-are present throughout the soot-formation region so that soot formation and oxidation proceed at the same time. Strong rates of soot growth compared to soot nucleation early in the soot-formation process, combined with increased rates of soot nucleation and oxidation as soot formation proceeds, causes primary soot particle diameters to reach a maximum relatively early in the soot-formation process. Aggregation of primary soot particles proceeds, however, until the final stages of soot oxidation. Present measurements of soot growth (corrected for soot oxidation) in laminar diffusion flames were consistent with earlier measurements of soot growth in laminar premixed flames and exhibited encouraging agreement with existing hydrogen-abstraction/carbon-addition (HACA) soot growth mechanisms in the literature that were developed based on measurements within laminar premixed flames. Measured primary soot particle nucleation rates in the present laminar diffusion flames also were consistent with corresponding rates measured in laminar premixed flames and yielded a crude correlation in terms of acetylene and H concentrations and the temperature.

Heavy metals distribution in soils surrounding an abandoned mine in NW Madrid (Spain) and their transference to wild flora.

PubMed

Moreno-Jiménez, Eduardo; Peñalosa, Jesús M; Manzano, Rebeca; Carpena-Ruiz, Ramón O; Gamarra, Roberto; Esteban, Elvira

2009-03-15

The present work concerns the distribution and mobility of heavy metals (Fe, Mn, Cu, Zn and Cd) in the surrounding soils of a mine site and their transfer to wild flora. Thus, soils and plants were sampled from a mining valley in NW Madrid (Spain), and total and extractable heavy metals were analysed. Soils affected by mining activities presented total Cd, Cu and Zn concentrations above toxic thresholds. The percentage of extractable element was highest for Cd and lowest for Cu. A highly significant correlation was observed between the total and extractable concentrations of metals in soils, indicating that, among the factors studied, total metals concentration is the most relevant for heavy metals extractability in these soils. (NH(4))(2)SO(4)-extractable metal concentrations in soils are correlated better with metal concentrations in several plant species than total metals in soils, and thus can be used as a suitable and robust method for the estimation of the phytoavailable fraction present in soils. Twenty-five vascular plant species (3 ferns and 22 flowering plants) were analysed, in order to identify exceptional characteristics that would be interesting for soil phytoremediation and/or reclamation. High Cd and Zn concentrations have been found in the aerial parts of Hypericum perforatum (Cd), Salix atrocinerea (Cd, Zn) and Digitalis thapsi (Cd, Zn). The present paper is, to the best of our knowledge, the first report of the metal accumulation ability of the two latter plant species. The phytoremediation ability of S. atrocinerea for Cd and Zn was estimated, obtaining intervals of time that could be considered suitable for the phytoextraction of polluted soils.

Statistical properties of fluctuating enzymes with dynamic cooperativity using a first passage time distribution formalism.

PubMed

Singh, Divya; Chaudhury, Srabanti

2017-04-14

We study the temporal fluctuations in catalytic rates for single enzyme reactions undergoing slow transitions between two active states. We use a first passage time distribution formalism to obtain the closed-form analytical expressions of the mean reaction time and the randomness parameter for reaction schemes where conformational fluctuations are present between two free enzyme conformers. Our studies confirm that the sole presence of free enzyme fluctuations yields a non Michaelis-Menten equation and can lead to dynamic cooperativity. The randomness parameter, which is a measure of the dynamic disorder in the system, converges to unity at a high substrate concentration. If slow fluctuations are present between the enzyme-substrate conformers (off-pathway mechanism), dynamic disorder is present at a high substrate concentration. Our results confirm that the dynamic disorder at a high substrate concentration is determined only by the slow fluctuations between the enzyme-substrate conformers and the randomness parameter is greater than unity. Slow conformational fluctuations between free enzymes are responsible for the emergence of dynamic cooperativity in single enzymes. Our theoretical findings are well supported by comparison with experimental data on the single enzyme beta-galactosidase.

Polyvinyl alcohol-based nanocomposite hydrogels containing magnetic laponite RD to remove cadmium.

PubMed

Mola Ali Abasiyan, Sara; Mahdavinia, Gholam Reza

2018-05-01

In this study, magnetic nanocomposite hydrogels based on polyvinyl alcohol were synthesized. Magnetic polyvinyl alcohol/laponite RD (PVA-mLap) nanocomposites were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The results indicated that PVA-mLap had desirable magnetic-sorption properties and magnetic-laponite nanoparticles were successfully synthesized and added to polyvinyl alcohol. The present nanocomposites were applied to remove Cd 2+ from aqueous solution. The influence of initial Cd 2+ concentration, magnetic-laponite concentration, pH, and ionic strength on adsorption isotherm was investigated. Heterogeneity of adsorption sites was intensified by increasing magnetic concentration of adsorbents and by rising pH value. Results of ionic strength studies indicated that by increasing ionic strength more than four times, the adsorption of Cd 2+ has only decreased around 15%. According to the results, the dominant mechanism of Cd 2+ sorption by the present adsorbents was determined chemical and specific sorption. Therefore, the use of the present nanocomposites as a powerful adsorbent of Cd 2+ in the wastewater treatment is suggested. Isotherm data were described by using Freundlich and Langmuir models, and better fitting was introduced Langmuir model.

Does Marcus-Hush theory really work Optical studies of intervalence transfer in acetylene-bridged biferrocene monocation at infinite dilution and at finite ionic strengths

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

Blackbourn, R.L.; Hupp, J.T.

1990-03-08

Intervalence charge-transfer data for acetylene-bridged biferrocene monocation (Bf{sup +}) have been collected in five solvents in the presence and absence of excess electrolyte and in the limit of infinite chromophore dilution. The study was motivated by earlier work which demonstrated that the intervalence absorption maximum for Bf{sup +} in methylene chloride could vary substantially with both chromophore concentration and added electrolyte concentration. In the present study similar (but smaller) variations are found in other solvents.

Sample pre-concentration with high enrichment factors at a fixed location in paper-based microfluidic devices.

PubMed

Yeh, Shih-Hao; Chou, Kuang-Hua; Yang, Ruey-Jen

2016-03-07

The lack of sensitivity is a major problem among microfluidic paper-based analytical devices (μPADs) for early disease detection and diagnosis. Accordingly, the present study presents a method for improving the enrichment factor of low-concentration biomarkers by using shallow paper-based channels realized through a double-sided wax-printing process. In addition, the enrichment factor is further enhanced by exploiting the ion concentration polarization (ICP) effect on the cathodic side of the nanoporous membrane, in which a stationary sample plug is obtained. The occurrence of ICP on the shallow-channel μPAD is confirmed by measuring the current-voltage response as the external voltage is increased from 0 to 210 V (or the field strength from 0 to 1.05 × 10(4) V m(-1)) over 600 s. In addition, to the best of our knowledge, the electroosmotic flow (EOF) speed on the μPAD fabricated with a wax-channel is measured for the first time using a current monitoring method. The experimental results show that for a fluorescein sample, the concentration factor is increased from 130-fold in a conventional full-thickness paper channel to 944-fold in the proposed shallow channel. Furthermore, for a fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA) sample, the proposed shallow-channel μPAD achieves an 835-fold improvement in the concentration factor. The concentration technique presented here provides a novel strategy for enhancing the detection sensitivity of μPAD applications.

A preliminary investigation on the distribution of cannabinoids in man.

PubMed

Gronewold, Antonia; Skopp, Gisela

2011-07-15

An LC/MS/MS procedure to determine THC along with its major metabolites 11-OH-THC, THC-COOH and its glucuronide as well as the cannabinoids CBD and CBN was applied to 5 post mortem cases to study their distribution into some less commonly studied matrices. Analytes were determined in fluids and tissue homogenates following protein precipitation and liquid-liquid extraction. Gall bladder fluid exhibited maximum concentrations of all analytes except THC, which was detectable in high concentrations in muscle tissue along with CBD. THC was also present in lung specimens, whereas its concentration in liver samples was low or not detectable at all. Liver und kidney specimens contained appreciable amounts of THC-COOglu. Findings from bile support extensive enterohepatic recirculation of the glucuronide. Muscle tissue seems an interesting specimen to detect multiple cannabis use, and brain may serve as an alternative specimen for blood; nevertheless, the present findings should be substantiated by further investigations. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Prediction of PM2.5 along urban highway corridor under mixed traffic conditions using CALINE4 model.

PubMed

Dhyani, Rajni; Sharma, Niraj; Maity, Animesh Kumar

2017-08-01

The present study deals with spatial-temporal distribution of PM 2.5 along a highly trafficked national highway corridor (NH-2) in Delhi, India. Population residing in areas near roads and highways of high vehicular activities are exposed to high levels of PM 2.5 resulting in various health issues. The spatial extent of PM 2.5 has been assessed with the help of CALINE4 model. Various input parameters of the model were estimated and used to predict PM 2.5 concentration along the selected highway corridor. The results indicated that there are many factors involved which affects the prediction of PM 2.5 concentration by CALINE4 model. In fact, these factors either not considered by model or have little influence on model's prediction capabilities. Therefore, in the present study CALINE4 model performance was observed to be unsatisfactory for prediction of PM 2.5 concentration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Onsite biological treatment of an industrial landfill leachate: Microbiological and engineering considerations

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

Skladany, G.J.

Successful biological treatment of ground waters, leachates, or industrial process waters requires the combined action of basic microbiological processes with sound process engineering designs. Such a treatment system is then able to both efficiently and cost-effectively remediate the contaminants present. In this case study, laboratory treatability studies were initially used to demonstrate that toluic acids present in an industrial landfill leachate were amenable to biological treatment. A continuous flow submerged fixed-film bioreactor was then chosen as the optimal equipment design for use at the site. The system was designed to treat a leachate flow of 800 to 2,000 gallons permore » day (gpd) containing total isomeric toluic acid concentrations of 300 to 400 parts per million (ppm). The treatment equipment has been in continuous operation since July 1987. During this period, the total influent isomertic toluic acid concentration has decreased to approximately 45 ppm, and specific effluent toluic acid concentrations have remained below the 0.5 ppm detection limit.« less

Electrochemical production and use of free chlorine for pollutant removal: an experimental design approach.

PubMed

Antonelli, Raissa; de Araújo, Karla Santos; Pires, Ricardo Francisco; Fornazari, Ana Luiza de Toledo; Granato, Ana Claudia; Malpass, Geoffroy Roger Pointer

2017-10-28

The present paper presents the study of (1) the optimization of electrochemical-free chlorine production using an experimental design approach, and (2) the application of the optimum conditions obtained for the application in photo-assisted electrochemical degradation of simulated textile effluent. In the experimental design the influence of inter-electrode gap, pH, NaCl concentration and current was considered. It was observed that the four variables studied are significant for the process, with NaCl concentration and current being the most significant variables for free chlorine production. The maximum free chlorine production was obtained at a current of 2.33 A and NaCl concentrations in 0.96 mol dm -3 . The application of the optimized conditions with simultaneous UV irradiation resulted in up to 83.1% Total Organic Carbon removal and 100% of colour removal over 180 min of electrolysis. The results indicate that a systematic (statistical) approach to the electrochemical treatment of pollutants can save time and reagents.

Evaluation of antibiofilm effect of benzalkonium chloride, iodophore and sodium hypochlorite against biofilm of Pseudomonas aeruginosa of dairy origin.

PubMed

Pagedar, Ankita; Singh, Jitender

2015-08-01

The present study was undertaken with objectives of; a) to investigate and compare Pseudomonas aeruginosa isolates from two dairies for biofilm formation potential and, b) to compares three common biocides for biofilm eradication efficiencies. Amongst the isolates from commercial dairy, 70 % were strong and/or moderate biofilm former in comparison to 40 % isolates from small scale dairy. All isolates, irrespective of source, exhibited higher susceptibility to biocides in planktonic stage than in biofilm. Antibiofilm efficiencies of three biocides i.e. benzalkonium chloride, sodium hypochlorite and iodophore were determined in terms of their microbial biofilms eradicating concentration (MBEC). Our findings show that the three biocides were ineffective against preformed biofilms at recommended in-use concentrations. Biofilms were the most resistant to benzalkonium chloride and least against iodophore. A trend of decreasing MBECs was observed with extended contact time. The findings of present study warrant for a systematic approach for selecting types and concentrations of biocide for application as antibiofilm agent in food industry.

Feline chronic renal failure: calcium homeostasis in 80 cases diagnosed between 1992 and 1995.

PubMed

Barber, P J; Elliott, J

1998-03-01

Eighty cats with chronic renal failure (CRF) were evaluated in a prospective study to investigate the prevalence and aetiopathogenesis of renal secondary hyperparathyroidism (RHPTH), using routine plasma biochemistry and assays of parathyroid hormone (PTH), blood ionised calcium and 1,25 dihydroxycholecalciferol (1,25[OH]2D3). Hyperparathyroidism was a frequent sequela of CRF, affecting 84 per cent of cats with CRF, the severity and prevalence of RHPTH increasing with the degree of renal dysfunction. Compared with an age-matched control population, plasma concentrations of phosphate and PTH were significantly higher and 1,25(OH)2D3 concentrations were significantly lower in the two groups of cats presenting with clinical signs of CRF. Significant ionised hypocalcaemia was present only in cats with end-stage renal failure. However, a number of cats were hyperparathyroid in the absence of abnormalities in the parameters of calcium homeostasis measured in this study. There was a significant correlation between plasma phosphate and PTH concentrations.

Probabilistic forecasting for extreme NO2 pollution episodes.

PubMed

Aznarte, José L

2017-10-01

In this study, we investigate the convenience of quantile regression to predict extreme concentrations of NO 2 . Contrarily to the usual point-forecasting, where a single value is forecast for each horizon, probabilistic forecasting through quantile regression allows for the prediction of the full probability distribution, which in turn allows to build models specifically fit for the tails of this distribution. Using data from the city of Madrid, including NO 2 concentrations as well as meteorological measures, we build models that predict extreme NO 2 concentrations, outperforming point-forecasting alternatives, and we prove that the predictions are accurate, reliable and sharp. Besides, we study the relative importance of the independent variables involved, and show how the important variables for the median quantile are different than those important for the upper quantiles. Furthermore, we present a method to compute the probability of exceedance of thresholds, which is a simple and comprehensible manner to present probabilistic forecasts maximizing their usefulness. Copyright © 2017 Elsevier Ltd. All rights reserved.

Allelopathic effect of Ashwagandha against the germination and radicle growth of Cicer arietinum and Triticum aestivum

PubMed Central

Chandra, Sangita; Chatterjee, Priyanka; Dey, Protapaditya; Bhattacharya, Sanjib

2012-01-01

Background: Ashwagandha (Withania somnifera) is an important medicinal plant in Indian traditional system of medicine and traditionally has been used for several medicinal purposes in the Indian subcontinent. Objective: The present study was aimed at the evaluation of allelopathic effect of hydroalcoholic extract of ashwagandha against germination and radicle growth of Cicer arietinum and Triticum aestivum seeds. Materials and Methods: The extract at different concentrations was incubated in controlled conditions with the surface sterilized seeds of C. arietinum and T. aestivum and observed periodically for seed germination and radicle growth to assess the allelopathic behavior. Results: The extract mainly at higher concentrations demonstrated promising allelopathic potential by significantly affecting seed germination and radicle elongation of both C. arietinum and T. aestivum in a concentration dependent manner. T. aestivum was found to be more sensitive than C. arietinum. Conclusion: The present study demonstrated remarkable allelopathic potential of ashwagandha against the test seeds. The effect was plausibly due to the alkaloid and withanolide contents of ashwagandha. PMID:22923955

Allelopathic effect of Ashwagandha against the germination and radicle growth of Cicer arietinum and Triticum aestivum.

PubMed

Chandra, Sangita; Chatterjee, Priyanka; Dey, Protapaditya; Bhattacharya, Sanjib

2012-07-01

Ashwagandha (Withania somnifera) is an important medicinal plant in Indian traditional system of medicine and traditionally has been used for several medicinal purposes in the Indian subcontinent. The present study was aimed at the evaluation of allelopathic effect of hydroalcoholic extract of ashwagandha against germination and radicle growth of Cicer arietinum and Triticum aestivum seeds. The extract at different concentrations was incubated in controlled conditions with the surface sterilized seeds of C. arietinum and T. aestivum and observed periodically for seed germination and radicle growth to assess the allelopathic behavior. The extract mainly at higher concentrations demonstrated promising allelopathic potential by significantly affecting seed germination and radicle elongation of both C. arietinum and T. aestivum in a concentration dependent manner. T. aestivum was found to be more sensitive than C. arietinum. The present study demonstrated remarkable allelopathic potential of ashwagandha against the test seeds. The effect was plausibly due to the alkaloid and withanolide contents of ashwagandha.

Association of dialysate bicarbonate concentration with mortality in the Dialysis Outcomes and Practice Patterns Study (DOPPS).

PubMed

Tentori, Francesca; Karaboyas, Angelo; Robinson, Bruce M; Morgenstern, Hal; Zhang, Jinyao; Sen, Ananda; Ikizler, T Alp; Rayner, Hugh; Fissell, Rachel B; Vanholder, Raymond; Tomo, Tadashi; Port, Friedrich K

2013-10-01

Most hemodialysis patients worldwide are treated with bicarbonate dialysis using sodium bicarbonate as the base. Few studies have assessed outcomes of patients treated with different dialysate bicarbonate levels, and the optimal concentration remains uncertain. The Dialysis Outcomes and Practice Patterns Study (DOPPS) is an international prospective cohort study. This study included 17,031 patients receiving thrice-weekly in-center hemodialysis from 11 DOPPS countries (2002-2011). Dialysate bicarbonate concentration. All-cause and cause-specific mortality and first hospitalization, using Cox regression to estimate the effects of dialysate bicarbonate concentration, adjusting for potential confounders. Demographics, comorbid conditions, laboratory values, and prescriptions were abstracted from medical records. Mean dialysate bicarbonate concentration was 35.5 ± 2.7 (SD) mEq/L, ranging from 32.2 ± 2.3 mEq/L in Germany to 37.0 ± 2.6 mEq/L in the United States. Prescription of high dialysate bicarbonate concentration (≥38 mEq/L) was most common in the United States (45% of patients). Approximately 50% of DOPPS facilities used a single dialysate bicarbonate concentration. 3,913 patients (23%) died during follow-up. Dialysate bicarbonate concentration was associated positively with mortality (adjusted HR, 1.08 per 4 mEq/L higher [95% CI, 1.01-1.15]; HR for dialysate bicarbonate ≥38 vs 33-37 mEq/L, 1.07 [95% CI, 0.97-1.19]). Results were consistent across levels of pre-dialysis session serum bicarbonate and between facilities that used a single dialysate bicarbonate concentration and those that prescribed different concentrations to individual patients. The association of dialysis bicarbonate concentration with mortality was stronger in patients with longer dialysis vintage. Due to the observational nature of the present study, we cannot rule out that the reported associations may be biased by unmeasured confounders. High dialysate bicarbonate concentrations, especially prolonged exposure, may contribute to adverse outcomes, likely through the development of postdialysis metabolic alkalosis. Additional studies are warranted to identify the optimal dialysate bicarbonate concentration. Copyright © 2013 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Analysis of concentration fluctuations in gas dispersion around high-rise building for different incident wind directions.

PubMed

Liu, X P; Niu, J L; Kwok, K C S

2011-09-15

This article presents experimental results that illustrate the unsteady characteristics of gas dispersion around a complex-shaped high-rise building for different incident wind directions. A series of wind tunnel experiments were conducted using a 1:30 scale model that represented the real structures under study. The objective of this paper is to study the behaviour of concentration fluctuations through transient analysis. Tracer gas was continuously released from a point source located at different positions, and a time series of fluctuating concentrations were recorded at a large number of points using fast flame ionization detectors. The experimental data were analysed to provide a comprehensive data set including variances and associated statistical quantities. Both the unsteady characteristics of the system and their potential practical impact are presented and discussed. Under crowd living conditions, the air pollutant exhausted from one household could probably re-enter into the neighbouring households, traveling with ambient airflow. Such pollutant dispersion process is defined as air cross-contamination in this study. The results indicate that the wind-induced cross-contamination around the studied type of high-rise building should not be overlooked, and the fluctuating concentrations should be paid attention to particularly during the evaluation of a potential contamination risk. This study can help deepen our understanding of the mechanisms of air cross-contamination, and will be useful for implementing optimization strategies to improve the built environments in metropolitan cities such as Hong Kong. Copyright © 2011 Elsevier B.V. All rights reserved.

Increases in heart rate and serum cortisol concentrations in healthy dogs are positively correlated with an indoor waiting-room environment.

PubMed

Perego, Roberta; Proverbio, Daniela; Spada, Eva

2014-03-01

Few studies have investigated the effect of veterinary clinical procedures on the welfare of dogs, with specific emphasis on the veterinary practice environment. Clinicopathologic variables have also not been assessed in these potentially stressful situations. Similar to human clinical studies, the veterinary clinical waiting room could present a significant stress factor for dogs. The present study was designed to investigate the effect of waiting-room environment on serum cortisol and glucose alterations as well as heart rate in privately owned healthy dogs. The clinical trial included 24 healthy dogs that were divided into 2 groups: the clinical waiting-room group (A) and the control group (B) that waited outside in a garden. During the entire experiment, 18 dogs (9 dogs per group) were monitored with a human heart rate monitor fastened around the chest. After 20 minutes of waiting, blood samples were collected from all of the dogs (24 dogs) to determine serum cortisol concentration. Serum cortisol concentration and mean, maximum, and minimum heart rate were significantly higher in group A compared with group B, but there was no statistical difference in serum glucose concentrations between the 2 study groups. Results of this study suggest that the waiting room is a potentially stressful situation for dogs in clinical veterinary practice, when compared with a garden, based on the assessment of adrenal cortex function and heart rate evaluation. © 2014 American Society for Veterinary Clinical Pathology and European Society for Veterinary Clinical Pathology.

Concentrating photovoltaic solar panel

DOEpatents

Cashion, Steven A; Bowser, Michael R; Farrelly, Mark B; Hines, Braden E; Holmes, Howard C; Johnson, Jr., Richard L; Russell, Richard J; Turk, Michael F

2014-04-15

The present invention relates to photovoltaic power systems, photovoltaic concentrator modules, and related methods. In particular, the present invention features concentrator modules having interior points of attachment for an articulating mechanism and/or an articulating mechanism that has a unique arrangement of chassis members so as to isolate bending, etc. from being transferred among the chassis members. The present invention also features adjustable solar panel mounting features and/or mounting features with two or more degrees of freedom. The present invention also features a mechanical fastener for secondary optics in a concentrator module.

Selenium in mainstream and sidestream smoke of cigarettes containing fly ash-grown tobacco

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

Gutenmann, W.H.; Lisk, D.J.; Shane, B.S.

The quantities of selenium, tar and nicotine present in mainstream (MS) and sidestream (SS) smoke of machine-smoked cigarettes was studied. The cigarettes were prepared from tobacco purposely cultured on fly ash-amended soil so as to increase its selenium concentration. Selenium concentration was found to be the same in the gaseous phase of both MS and SS smoke, but its concentration was significantly higher (p less than 0.05) in the particulate matter of the MS smoke. Tar was higher in MS smoke and nicotine in SS smoke. Factors affecting selenium concentrations in tobacco and its possible environmental significance are discussed.

Estimation of porphyrin concentration in the kerogen fraction of shales using high-resolution reflectance spectroscopy

NASA Technical Reports Server (NTRS)

Holden, Peter N.; Gaffey, Michael J.; Sundararaman, P.

1991-01-01

An interpretive model for estimating porphyrin concentration in bitumen and kerogen from spectral reaflectance data in the visible and near-ultraviolet region of the spectrum is derived and calibrated. Preliminary results obtained using the model are consistent with concentrations determined from the bitumen extract and suggest that 40 to 60 percent of the total porphyrin concentration remains in the kerogen after extraction of bitumen from thermally immature samples. The reflectance technique will contribute to porphyrin and kerogen studies and can be applied at its present level of development to several areas of geologic and paleo-oceanographic research.

Glycerophosphate-dependent peroxide production by brown fat mitochondria from newborn rats.

PubMed

Drahota, Z; Rauchova, H; Jesina, P; Vojtísková, A; Houstek, J

2003-03-01

Glycerophosphate (GP)-dependent, ferricyanide-induced hydrogen peroxide production was studied in brown adipose tissue mitochondria from newborn rats. Relations between the rate of hydrogen peroxide production and total amount of hydrogen peroxide produced at different GP and ferricyanide concentrations were determined. It was found that the rate of hydrogen peroxide production increases with increasing GP concentration and decreases with increasing ferricyanide concentration. Total amount of hydrogen peroxide produced increases with increasing ferricyanide concentration, however, not proportionally, and the efficiency of this process (oxygen/ferricyanide ratio) strongly declines. Data presented provide further information on the character and kinetics of hydrogen peroxide production by mammalian mitochondrial glycerophosphate dehydrogenase.

Stevia preferences in Wistar rats.

PubMed

Núñez Martínez, Paula; Argüelles Luis, Juan; Perillán Méndez, Carmen

2016-11-01

The Stevia rebaudiana plant is likely to become a major source of high-potency sweetener for the growing natural-food market. S. rebaudiana is the source of a number of sweet diterpenoid glycosides, but the major sweet constituents are rebaudioside A and stevioside. These two constituents have similar pharmacokinetic and metabolic profiles in rats and humans, and thus, studies carried out with either steviol glycoside are relevant to both. Other studies illustrate the diversity of voluntary sweet intake in mammals. This study was done using a series of two-bottle tests that compared a wide range of sweetener concentrations versus saccharin concentrations and versus water. Wistar rats displayed preferences for stevia extract and pure rebaudioside A solutions over water at a range of concentrations (0.001% to 0.3%), and their intake peak occurred at 0.1% concentration. They also preferred solutions prepared with a commercial rebaudioside A plus erythritol mixture to water, and their peak was at 2% concentration. The present study provides new information about the responses of Wistar rats to stevia compounds and commercial stevia products such as Truvia. These results could help with the appropriate dosage selection for focused behavioral and physiological studies on stevia.

Fish mercury increase in Lago Manso, a new hydroelectric reservoir in tropical Brazil.

PubMed

Hylander, Lars D; Gröhn, Janina; Tropp, Magdalena; Vikström, Anna; Wolpher, Henriette; de Castro E Silva, Edinaldo; Meili, Markus; Oliveira, Lázaro J

2006-10-01

It has been frequently demonstrated that mercury (Hg) concentrations in fish rise in newly constructed hydroelectric reservoirs in the Northern Hemisphere. In the present work, we studied whether similar effects take place also in a tropical upland reservoir during impoundment and discuss possible causes and implications. Total Hg concentrations in fish and several soil and water parameters were determined before and after flooding at Rio Manso hydroelectric power plant in western Brazil. The Hg concentrations in soil and sediment were within the background levels in the region (22-35 ng g(-1) dry weight). There was a strong positive correlation between Hg and carbon and sulphur in sediment. Predatory fish had total Hg concentrations ranging between 70 and 210 ng g(-1) f.w. 7 years before flooding and between 72 and 755 ng g(-1) f.w. during flooding, but increased to between 216 and 938 ng g(-1) f.w. in the piscivorous and carnivorous species Pseudoplatystoma fasciatum, cachara, and Salminus brasiliensis, dourado, 3 years after flooding. At the same time, concentrations of organic carbon in the water increased and oxygen concentrations decreased, indicating increased decomposition and anoxia as contributing to the increased Hg concentrations in fish. The present fish Hg concentrations in commonly consumed piscivorous species are a threat to the health of the population dependent on fishing in the dam and downstream river for sustenance. Mercury exposure can be reduced by following fish consumption recommendations until fish Hg concentrations decrease to a safe level.

Elastic constants and pressure derivative of elastic constants of Si1-xGex solid solution

NASA Astrophysics Data System (ADS)

Jivani, A. R.; Baria, J. K.; Vyas, P. S.; Jani, A. R.

2013-02-01

Elastic properties of Si1-xGex solid solution with arbitrary (atomic) concentration (x) are studied using the pseudo-alloy atom model based on the pseudopotential theory and on the higher-order perturbation scheme with the application of our own proposed model potential. We have used local-field correction function proposed by Sarkar et al to study Si-Ge system. The Elastic constants and pressure derivatives of elastic constants of the solid solution is investigated with different concentration x of Ge. It is found in the present study that the calculated numerical values of the aforesaid physical properties of Si-Ge system are function of x. The elastic constants (C11, C12 and C44) decrease linearly with increase in concentration x and pressure derivative of elastic constants (C11, C12 and C44) increase with the concentration x of Ge. This study provides better set of theoretical results for such solid solution for further comparison either with theoretical or experimental results.

Assessment of Accumulation Processes at the Middle Pleistocene Site of Ambrona (Soria, Spain). Density and Orientation Patterns in Spatial Datasets Derived from Excavations Conducted from the 1960s to the Present

PubMed Central

Sánchez-Romero, Laura; Benito-Calvo, Alfonso; Pérez-González, Alfredo; Santonja, Manuel

2016-01-01

The Middle Pleistocene site of Ambrona (Soria, Spain) is a major reference for European Acheulean studies. The origin of the lithic and fauna accumulations at this site was first thought to be anthropogenic, but later studies showed that it was mainly natural. The first person to conduct excavations at the Ambrona site was the Marquis of Cerralbo, in 1914; other research groups followed in more recent times (the Howell & Freeman team and the Santonja & Pérez-González team). The digs yielded a great amount of information, but until now it had never been unified. In this paper, we compile all the available published and unpublished excavation documentation from the 1960s to the present. We use these maps and sections to present our spatial study of the LSM (Lower Stratigraphic Member) at the Ambrona site, combining stratigraphic criteria with GIS density and orientation analysis. This study enabled us to define the main concentrations of the LSM, providing an initial contribution to an assessment of their accumulation processes. Most of the concentrations preserved in the ancient shore area of the site display marked orientation patterns which coincide with the direction of the main water flows into the Ambrona wetland. However, random orientation patterns were observed in the central part of the site (Alpha concentration); they may be mostly preserved without undergoing transport processes, as previous taphonomic studies also confirm. PMID:28002424

Hyperspectral remote sensing study of harmful algal blooms in the Chesapeake Bay

NASA Astrophysics Data System (ADS)

Nie, Yixiang

Recent development of hyperspectral remote sensing provides capability to identify and classify harmful algal blooms beyond the estimation of chlorophyll concentrations. This study uses hyperspectral data to extract spectral signatures, classify algal blooms, and map the spatial distribution of the algal blooms in the upper Chesapeake Bay. Furthermore, water quality parameters from ground stations have been used together with remote sensing data to provide better understanding of the formation and transformation of the life cycle of harmful algal blooms, and the cause of their outbreaks in the upper Chesapeake Bay. The present results show a strong and significant positive correlation between chlorophyll concentrations and total organic nitrogen concentrations. This relation suggests that total organic nitrogen played an important role in triggering the harmful algal blooms in the upper Chesapeake Bay in this study. This study establishes an integrated approach which combines hyperspectral imaging with multispectral ocean color remote sensing data and traditional water quality monitoring system in the study of harmful algal blooms in small water bodies such as the Chesapeake Bay. Presently, remote sensing is well integrated into the research community, but is less commonly used by resource managers. This dissertation couples remote sensing technologies with specific monitoring programs. The present results will help natural resource managers, local authorities, and the public to utilize an integrated approach in order to better understand, evaluate, preserve, and restore the health of the Chesapeake Bay waters and habitats.

Elevated radionuclide concentrations in heavy mineral-rich beach sands in the Cox's Bazar region, Bangladesh and related possible radiological effects.

PubMed

Zaman, Mashrur; Schubert, Michael; Antao, Sytle

2012-01-01

The study focuses on elevated levels of environmental radioactivity present in heavy mineral deposits located along a 120-km coastal section of Cox's Bazar on the eastern panhandle of Bangladesh. The deposits are situated in or at sand dunes located on the recent beach (foredune area) or in attached paleo-beach areas (backdune area). This study investigates activity concentrations in bulk beach sands (six representative samples) and in five mineral fractions separated from the beach sands in order to assess potential radio-ecological effects and the possible use of the mineral deposits as a source for uranium and thorium. The bulk beach sands and individual mineral fractions were analysed by gamma-ray spectroscopy. The activity concentrations of U-238, U-235, Th-232 and K-40 in the bulk beach sand samples were found to be considerably high and positively correlated to the concentration of heavy minerals in the sand. In the mineral fractions, the highest activity concentrations were found in the zircon fraction followed by garnet, rutile, ilmenite and magnetite. The determination of (i) the radium activity, (ii) several radiation hazard indices and (iii) adsorbed and effective gamma doses allowed to assess the related exposure of the environment and the local population to elevated radioactivity. It becomes evident from the present data that (1) if raw sands or mineral fractions mined in the study area are used for building purposes or industrial use, their activity concentrations have to be considered from a radio-ecological perspective and (2) if mining and processing of the minerals is being considered, uranium and thorium may become strategically significant by-products.

Reproductive success, early life stage development, and survival of westslope cutthroat trout (Oncorhynchus clarki lewisi) exposed to elevated selenium in an area of active coal mining

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

Barri-Lynn Rudolph; Iisak Andreller; Christopher J. Kennedy

2008-04-15

The effects of accumulated Se on the reproductive success and larval development of cutthroat trout (Oncorhynchus clarki lewisi) collected from a site of active coal mining in British Columbia were assessed. Eggs from 12 fish from an exposed site (Clode Pond) and 16 from a reference site (O'Rourke Lake) were field-collected and reared in the laboratory. Egg Se concentrations ranged from 12.3 to 16.7 and 11.8 to 140.0 {mu}g/g dry weight (dw) from fish collected at the reference and exposed sites, respectively. Other studies, including those with this species, have not shown Se to affect egg viability. However, in themore » present study, eggs with Se concentrations >86.3 {mu}g/g dw were not successfully fertilized or were nonviable at fertilization, while eggs with concentrations >46.8 and <75.4 {mu}g/g dw were fertilized (96% reached the eyed stage) but did not produce viable fry. A significant positive relationship between egg Se concentration and alevin mortality was observed. Deformities were analyzed in surviving fry which developed from eggs with Se concentrations between 11.8 and 20.6 {mu}g/g dw. No relationship between Se concentration in eggs and deformities or edema was found in this range, suggesting that the no-effect threshold for deformity is >20.6 {mu}g/g dw. The present data, in conjunction with the data from several other studies in temperate fish, suggest that current Se thresholds are conservative for cold-water fish. 25 refs., 3 figs.« less

Simultaneous arsenic and fluoride removal from synthetic and real groundwater by electrocoagulation process: Parametric and cost evaluation.

PubMed

Thakur, Lokendra Singh; Mondal, Prasenjit

2017-04-01

Co-existence of arsenic and fluoride in groundwater has raised severe health issues to living being. Thus, the present research has been conducted for simultaneous removal of arsenic and fluoride from synthetic groundwater by using electrocoagulation process with aluminum electrode. Effects of initial pH, current density, run time, inter electrode distance and NaCl concentration over percentage removal of arsenic and fluoride as well as operating cost have been studied. The optimum experimental conditions are found to be initial pH: 7, current density: 10 A/m 2 , run time: 95 min, inter electrode distance: 1 cm, NaCl concentration: 0.71 g/l for removal of 98.51% arsenic (initial concentration: 550 μg/l) and 88.33% fluoride (initial concentration: 12 mg/l). The concentration of arsenic and fluoride in treated water are found to be 8.19 μg/l and 1.4 mg/l, respectively, with an operating cost of 0.357 USD/m 3 treated water. Pseudo first and second order kinetic model of individual and simultaneous arsenic and fluoride removal in electrocoagulation have also been studied. Produced sludge characterization studies also confirm the presence of arsenic in As(III) form, and fluoride in sludge. The present electrocoagulation process is able to reduce the arsenic and fluoride concentration of synthetic as well as real groundwater to below 10 μg/l and 1.5 mg/l, respectively, which are maximum contaminant level of these elements in drinking water according to WHO guidelines. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optical method for continuous monitoring of dust deposition in mine's entry / Optyczna metoda ciągłego pomiaru intensywności osiadania pyłu węglowego w wyrobisku górniczym

NASA Astrophysics Data System (ADS)

2012-12-01

The paper presents factors determining dust explosion hazards occurring in underground hard coal mines. The authors described the mechanism of transport and deposition of dust in mines entries and previous research on this topic. The paper presents a method of determination of depositing dust distribution during mining and presents the way to use it to assess coal dust explosion risk. The presented method of calculating the intensity of coal dust deposition is based on continuous monitoring of coal dust concentrations with use of optical sensors. Mathematical model of the distribution of the average coal dust concentration was created. Presented method allows to calculate the intensity of coal dust deposition in a continuous manner. Additionally, the authors presented the PŁ-2 stationary optical dust sampler, used in the study, connected to the monitoring system in the mine. The article features the results of studies conducted in the return air courses of the active longwalls, and the results of calculations of dust deposition intensity carried out with the use of the presented method.

Influence of wine pectic polysaccharides on the interactions between condensed tannins and salivary proteins.

PubMed

Carvalho, Elisabete; Mateus, Nuno; Plet, Benoit; Pianet, Isabelle; Dufourc, Erick; De Freitas, Victor

2006-11-15

Alpha-amylase, a major human salivary protein, and IB8c, a representative of the proline-rich proteins, were obtained by isolation from saliva and by solid-phase synthesis, respectively. The interactions between these proteins and condensed tannins isolated from grape seeds were studied at different protein and tannin concentrations by measuring their aggregation. Pectic polysaccharides were isolated from wine, and their effect on protein tannin aggregation was assessed. The results presented in this study showed that the most acidic fractions of arabinogalactan proteins have the ability to inhibit the formation of aggregates between the grape seed tannins and the two different salivary proteins. Rhamnogalacturonan II has the same ability toward alpha-amylase but not IB8c under the conditions of the present study. Polysaccharides show effects at concentrations at which they are present in wine, which could mean an influence in wine astringency. The interaction between condensed tannins and alpha-amylase is differently affected by ionic strength when compared with IB8c.

Bioaccumulation of heavy metals by freshwater algal species of Bhavnagar, Gujarat, India.

PubMed

Jaiswar, Santial; Kazi, Mudassar Anisoddin; Mehta, Shailesh

2015-11-01

The present study investigated copper, cadmium, lead and zinc accumulation in algal species Oedogonium, Cladophora, Oscillatoria and Spirogyra from freshwater habitats of Bhavnagar, India. Eight different locations were periodically sampled during August 2009 to March 2011. The general trend of heavy metal concentrations in all the algal species in present study (except at few stations), were found to be in the following order: Zn > Cu > Pb > Cd. Highest accumulation of Cu was recorded in Oedogonium, while Cladophora showed highest accumulation of Pb signifying a good bioaccumulator. Oscillatoria and Oedogonium were highest Zn accumulating algae which showed significant difference between the means at P < 0.05. ANOVA was performed for comparing significance mean between the groups and within the group for heavy metals in water. The concentration of heavy metals in water was in the following order: Zn > Cu > Pb > Cd. The present study showed that Oedogonium, Cladophora, Oscillatoria and Spirogyra were excellent bioaccumulator and could be utilized as biomonitoring agents in water bodies receiving waste contaminated by metals.

Evaluation of the in vitro cytogenotoxicity profile of antipsychotic drug haloperidol using human peripheral blood lymphocytes.

PubMed

Gajski, Goran; Gerić, Marko; Garaj-Vrhovac, Vera

2014-07-01

Haloperidol (HLP) is a potent antipsychotic drug that is commonly used for the treatments of schizophrenia and bipolar disorders but has a tendency to cause adverse effects. In the present study, the cyto/genotoxic potential of clinically relevant concentrations of HLP was evaluated in human peripheral blood lymphocytes (HPBLs) as sensitive biomarkers of exposure. HLP was administered as HLP hydrochloride in the final concentrations of 5, 10 and 20 ng/ml for 4 and 24 h period. Cytotoxicity was determined using differential staining of HPBLs with acridine orange and ethidium bromide while chromosomal aberrations, micronucleus and comet assays were applied to estimate the chromosomal and DNA damage after the treatment. The results of the present study indicate that HLP is capable of inducing cyto/genotoxicity in tested cells. Present study has also confirmed the need for further cytogenetic research and regular patient monitoring to minimize the risk of any possible adverse events. Copyright © 2014 Elsevier B.V. All rights reserved.

Feline chronic renal failure: clinical findings in 80 cases diagnosed between 1992 and 1995.

PubMed

Elliott, J; Barber, P J

1998-02-01

Clinical and laboratory findings at the time of first diagnosis in 80 cats with chronic renal failure (CRF) were examined in a prospective study to determine the survival time of these animals and identify possible factors contributing to the progression of feline CRF. On the basis of clinical presentation, animals were assigned to one of three groups; compensated (n = 15), uraemic (n = 39) and end-stage (n = 26) CRF. Loss of renal concentrating ability was a common finding, even before clinical signs of renal disease were evident. The plasma creatinine concentration at initial presentation was a poor predictor of survival time and the presence of significant anaemia was indicative of a poor prognosis. The study demonstrated the highly variable degree of renal impairment present at the time of diagnosis and the potentially long survival time of many compensated and uraemic cases.

Heavy metal concentration in mangrove surface sediments from the north-west coast of South America.

PubMed

Fernández-Cadena, J C; Andrade, S; Silva-Coello, C L; De la Iglesia, R

2014-05-15

Mangrove ecosystems are coastal estuarine systems confined to the tropical and subtropical regions. The Estero Salado mangrove located in Guayaquil, Ecuador, has suffered constant disturbances during the past 20 years, due to industrial wastewater release. However, there are no published data for heavy metals present in its sediments and the relationship with anthropogenic disturbance. In the present study, metal concentrations were evaluated in surface sediment samples of the mangrove, showing that B, Cd, Cu, Pb, Se, V, and Zn levels exceeded those declared in international environmental quality standards. Moreover, several metals (Pb, Sn, Cd, Ag, Mo, Zn and Ni) could be linked to the industrial wastewater present in the studied area. In addition, heavy metal levels detected in this mangrove are higher than previous reports on mangrove sediments worldwide, indicating that this mangrove ecosystem is one of the most disrupted on earth. Copyright © 2014 Elsevier Ltd. All rights reserved.

Alterations of tissue metallothionein and vitellogenin concentrations in tropical cup oysters (Saccostrea sp.) following short-term (96h) exposure to cadmium.

PubMed

Moncaleano-Niño, Angela M; Barrios-Latorre, Sergio A; Poloche-Hernández, Javier F; Becquet, Vanessa; Huet, Valérie; Villamil, Luisa; Thomas-Guyon, Hélène; Ahrens, Michael J; Luna-Acosta, Andrea

2017-04-01

Metallothioneins and vitellogenins are low molecular weight proteins that have been used widely in environmental monitoring as biomarkers of exposure and damage to metals and estrogenic compounds, respectively. In the present study, the responses of metallothionein and vitellogenin tissue concentrations were measured following acute (96h) aqueous exposures to cadmium in Saccostrea sp., a tropical cup oyster native to the Western Pacific Ocean that has recently established itself in the Caribbean Sea. Adult oysters (1.5-5.0cm shell length) collected from the municipal marina of Santa Marta, Colombia (Caribbean Sea) and acclimated for 5days in the laboratory, were exposed to Cd at five concentrations (0, 1, 10, 100 and 1000μg/L) and their tissues (gills, digestive gland and adductor muscle) were analyzed in pools of 5 individuals (3 replicates per concentration). Metallothioneins in digestive glands of oysters exposed to Cd concentrations≥100μg/L showed a significant increase, from 8.0 to 14.8μg MT/mg total protein, whereas metallothionein concentrations in gills increased to lesser extent, and no differences were observed in adductor muscle. Metallothionein concentrations in digestive gland and gills correlated directly with whole soft tissue Cd concentrations (ranging from 2 to 297μg/g dw Cd). Vitellogenin in homogenates of oyster gonad tissue, after 96h of exposure to 1000μg/L Cd, were significantly lower (0.04mg P/g gonad) compared to control oysters (0.68mg P/g gonad), suggestive of an anti-estrogenic effect of Cd at high concentrations, whereas no significant changes in vitellogenin concentrations were observed at intermediate Cd exposure concentrations. This study confirms acute responses of metallothionein and vitellogenin concentrations in tissues of Saccostrea sp. exposed to high concentrations of cadmium (Cd≥100μg/L, 96h). The present results are first step towards validating the use of these two proteins as biomarkers of metal exposure in this species. Copyright © 2017 Elsevier B.V. All rights reserved.

Frequency domain phosphorescence lifetime Imaging measurements and applications by ISS FastFLIM and multi pulse excitation

NASA Astrophysics Data System (ADS)

Coskun, Ulas C.; Lam, Sandra; Sun, Yuansheng; Liao, Shih-Chu Jeff; George, Steven C.; Barbieri, Beniamino

2017-02-01

Phosphorescence probes can have significantly long lifetimes, on the order of micro- to milli-seconds or longer. In addition, environmental changes can affect the lifetimes of these phosphorescence probes. Thus, Phosphorescence Lifetime Imaging Microscopy (PLIM) is a very useful tool to localize the phosphorescence probes based on their lifetimes to study the variance in the lifetimes due to the micro environmental changes. Since the probes respond to the biologically relevant parameters like oxygen concentration, they can be used to study various biologically relevant processes like cellular metabolism, protein interaction etc. In this case, we study the effects of oxygen on Oxyphor G4 with PLIM. Since The Oxyphor G4 can be quenched by O2, it is a good example of such a probe and has a lifetime around 250us. Here we present the digital frequency domain PLIM technique and study the lifetime of the Oxyphor G4 as a function of the O2 concentration. The lifetime data are successfully presented in a phasor plot for various O2 concentrations and are consistent with the time domain data. Overall, we can analyze the oxygen consumption of varying cells using this technique.

Relationship between effort-reward imbalance and hair cortisol concentration in female kindergarten teachers.

PubMed

Qi, Xingliang; Zhang, Jing; Liu, Yapeng; Ji, Shuang; Chen, Zheng; Sluiter, Judith K; Deng, Huihua

2014-04-01

The present study aims to investigate the relationship between effort-reward imbalance and hair cortisol concentration among teachers to examine whether hair cortisol can be a biomarker of chronic work stress. Hair samples were collected from 39 female teachers from three kindergartens. Cortisol was extracted from the hair samples with methanol, and cortisol concentrations were measured with high performance liquid chromatography-tandem mass spectrometry. Work stress was measured using the effort-reward imbalance scale. The ratio of effort to reward showed significantly positive association with hair cortisol concentration. The cortisol concentration in the system increases with the effort-reward imbalance. Measurement of hair cortisol can become a useful biomarker of chronic work stress. Copyright © 2014 Elsevier Inc. All rights reserved.

Performance comparison of four kinds of flat nonimaging Fresnel lenses made of polycarbonates and polymethyl methacrylate for concentrated photovoltaics.

PubMed

Languy, Fabian; Habraken, Serge

2011-07-15

Solar concentrators made of a single refractive primary optics are limited to a concentration ratio of about 1000× [Opt. Express 19, A280 (2011)], due only to longitudinal chromatic aberration, while mirrors are limited to ∼46,000× by the angular size of the Sun. To reduce the chromatic aberration while keeping cost-effective systems for concentrated photovoltaics, a study of four different kinds of flat Fresnel doublets made of polycarbonates and polymethyl methacrylate is presented. It reveals that Fresnel doublets may have fewer optical losses than non-Fresnel doublets, with a lower lateral chromatic split allowing for even higher concentration ratio. © 2011 Optical Society of America

Study on the number density of nanobubbles at varying concentration of ethanol in ethanol-water solution

NASA Astrophysics Data System (ADS)

Rajib, Md. Mahadi; Farzeen, Parisa; Ali, Mohammad

2017-12-01

In recent years, nanobubble technology has drawn great attention due to its extensive incorporation to substantial aspects of science and technology such as water treatment, drug delivery enhancement to cells, solvent and nutritional supplements manufacturing and many others. Bulk nanobubbles may be present in most aqueous solutions, possibly being constantly created by cosmic radiation and agitation and surface nanobubbles are present at most surfaces [1,2]. But, for utilizing these nanobubbles in a definitive way it's important to know whether an added amount of solution making substance has constructive or adverse effect on the nanobubble. In this work, the change of number density of nanobubbles in ethanol-water solution was studied by varying the ethanol concentration.

Morphological Effect of Pd Catalyst on Ethanol Electro-Oxidation Reaction

PubMed Central

Cerritos, Raúl Carrera; Guerra-Balcázar, Minerva; Ramírez, Rosalba Fuentes; Ledesma-García, Janet; Arriaga, Luis Gerardo

2012-01-01

In the present study, three different structures with preferentially exposed crystal faces were supported on commercial carbon black by the polyol method (nanoparticles (NP/C), nanobars (NB/C) and nanorods (NR/C)). The electrocatalysts were characterized by XRD, TEM, TGA and cyclic voltammetry at three different ethanol concentrations. Considerable differences were found in terms of catalytic electroactivity. At all ethanol concentrations, the trend observed for the ethanol oxidation peak potential was preserved as follows: NB/C < NP/C< NR/C < commercial Pd/C. This result indicates that, from a thermodynamics point of view, the NB/C catalyst enclosed by Pd(100) facets presented the highest activity with respect to ethanol electro-oxidation among all of the catalysts studied.

THE LONDON LOW EMISSION ZONE BASELINE STUDY

EPA Science Inventory

The investigators hope that the LEZ baseline study will present a creative effort to lay the groundwork for studying spatial and temporal changes in air pollutant concentrations and health outcomes in advance of a major regulatory intervention. It is hope that the study wil...

Temperature responses to infusion of electrolytes during exercise

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Kozlowski, S.; Kaciuba-Uscilko, H.; Nazar, K.; Brzezinska, Z.

1975-01-01

Past studies on the influence of various metal ions on heat regulation in mammals are reviewed, and results of a study on the effect of Na and citrate in isotonic and hypertonic concentrations on temperature elevation during exercise in dogs are presented. Hypertonic administration of Na before or during treadmill running and dosis of citrate during treadmill running significantly raised core temperature over controls and isotonic cases. Thus the higher the plasma Na-osmotic concentration, the greater the inhibition of heat dissipation.

Influence of bromide on the performance of the amphipod Hyalella azteca in reconstituted waters

USGS Publications Warehouse

Ivey, Chris D.; Ingersoll, Christopher G.

2016-01-01

Poor performance of the amphipod Hyalella azteca has been observed in exposures using reconstituted waters. Previous studies have reported success in H. azteca water-only exposures with the addition of relatively high concentrations of bromide. The present study evaluated the influence of lower environmentally representative concentrations of bromide on the response ofH. azteca in 42-d water-only exposures. Improved performance of H. azteca was observed in reconstituted waters with >0.02 mg Br/L.

Spherical cloaking using nonlinear transformations for improved segmentation into concentric isotropic coatings.

PubMed

Qiu, Cheng-Wei; Hu, Li; Zhang, Baile; Wu, Bae-Ian; Johnson, Steven G; Joannopoulos, John D

2009-08-03

Two novel classes of spherical invisibility cloaks based on nonlinear transformation have been studied. The cloaking characteristics are presented by segmenting the nonlinear transformation based spherical cloak into concentric isotropic homogeneous coatings. Detailed investigations of the optimal discretization (e.g., thickness control of each layer, nonlinear factor, etc.) are presented for both linear and nonlinear spherical cloaks and their effects on invisibility performance are also discussed. The cloaking properties and our choice of optimal segmentation are verified by the numerical simulation of not only near-field electric-field distribution but also the far-field radar cross section (RCS).

Summary of information on synthetic organic compounds and trace elements in tissue of aquatic biota, Clark Fork-Pend Oreille and Spokane River basins, Montana, Idaho, and Washington, 1974-96

USGS Publications Warehouse

Maret, Terry R.; Dutton, DeAnn M.

1999-01-01

As part of the Northern Rockies Intermontane Basins study of the National Water-Quality Assessment Program, data collected between 1974 and 1996 were compiled to describe contaminants in tissue of riverine species. Tissue-contaminant data from 11 monitoring programs and studies representing 28 sites in the study area were summarized. Tissue-contaminant data for most streams generally were lacking. Many studies have focused on and around mining-affected areas on the Clark Fork and Coeur d'Alene Rivers and their major tributaries. DDT and PCBs and their metabolites and congeners were the synthetic organic contaminants most commonly detected in fish tissue. Fish collected from the Spokane River in Washington contained elevated concentrations of PCB arochlors, some of which exceeded guidelines for the protection of human health and predatory wildlife. Tissue samples of fish from the Flathead River watershed contained higher-than-expected concentrations of PCBs, which might have resulted from atmospheric transport. Trace element concentrations in fish and macroinvertebrates collected in and around mining areas were elevated compared with background concentrations. Some cadmium, copper, lead, and mercury concentrations in fish tissue were elevated compared with results from other studies, and some exceeded guidelines. Macroinvertebrates from the Coeur d'Alene River contained higher concentrations of cadmium, lead, and zinc than did macroinvertebrates from other river systems in mining-affected areas. A few sportfish fillet samples, most from the Spokane River in Washington, were collected to assess human health risk. Concentrations of PCBs in these fillets exceeded screening values for the protection of human health. At present, there is no coordinated, long-term fish tissue monitoring program for rivers in the study area, even though contaminants are present in fish at levels considered a threat to human health. Development of a coordinated, centralized national data base for contaminants in fish tissue is needed. The National Water-Quality Assessment Program can provide a framework for other agencies to evaluate tissue contaminants in the Northern Rockies Intermontane Basins study area. As of 1996, there are no fish consumption advisories or fishing restrictions as a result of elevated contaminants on any rivers within the study area.

New dual asymmetric CEC linear Fresnel concentrator for evacuated tubular receivers

NASA Astrophysics Data System (ADS)

Canavarro, Diogo; Chaves, Julio; Collares-Pereira, Manuel

2017-06-01

Linear Fresnel Reflector concentrators (LFR) are a potential solution for low-cost electricity production. Nevertheless in order to become more competitive with other CSP (Concentrated Solar Power) technologies, in particular with the Parabolic Trough concentrator, their overall solar to electricity efficiencies must increase. A possible path to achieve this goal is to increase the concentration factor, hence increasing the working temperatures for higher thermodynamic efficiency (more energy collection) and decrease the total number of rows of the solar field (less parasitic losses and corresponding cost reduction). This paper presents a dual asymmetric CEC-type (Compound Elliptical Concentrator) LFR (Linear Fresnel Concentrator) for evacuated tubular receivers. The concentrator is designed for a high concentration factor, presenting an asymmetric configuration enabling a very compact solution. The CEC-type secondary mirror is introduced to accommodate very high concentration values with a wide enough acceptance-angle (augmenting optical tolerances) for simple mechanical tracking solutions, achieving a higher CAP (Concentration Acceptance Product) in comparison with conventional LFR solutions. The paper presents an optical and thermal analysis of the concentrator using two different locations, Faro (Portugal) and Hurghada (Egypt).

Changes of serum 3-methylhistidine concentration and energy-associated metabolites in dairy cows with ketosis.

PubMed

Akamatsu, Hirohisa; Saitoh, Yoshihide; Serizawa, Masahumi; Miyake, Koji; Ohba, Yoshikazu; Nakashima, Kazuki

2007-10-01

The present study examined the Serum 3-methylhistidine concentrations and energy-associated variables of 5 healthy Holstein cows and 5 Holstein cows with ketosis. The serum total cholesterol and apolipoprotein B-100 concentrations and lecithin-cholesterol acyltransferase (LCAT) activity of the ketotic cows were lower than those of the healthy cows 14 days before parturition. The serum non-esterified fatty acid (NEFA) concentration on the day of parturition and 3-methylhistidine concentration 14 days after parturition were higher in the ketotic cows. The serum 3-methylhistidine concentration 14 days after parturition was negatively correlated with the serum LCAT activity 14 days before parturition and was positively correlated with the serum NEFA concentration on the day of parturition. Insufficiency of cholesterol metabolism and acceleration of body fat degradation occur before parturition in cows with ketosis, and these characteristics are correlated with acceleration of protein degradation after parturition.

A network property necessary for concentration robustness

NASA Astrophysics Data System (ADS)

Eloundou-Mbebi, Jeanne M. O.; Küken, Anika; Omranian, Nooshin; Kleessen, Sabrina; Neigenfind, Jost; Basler, Georg; Nikoloski, Zoran

2016-10-01

Maintenance of functionality of complex cellular networks and entire organisms exposed to environmental perturbations often depends on concentration robustness of the underlying components. Yet, the reasons and consequences of concentration robustness in large-scale cellular networks remain largely unknown. Here, we derive a necessary condition for concentration robustness based only on the structure of networks endowed with mass action kinetics. The structural condition can be used to design targeted experiments to study concentration robustness. We show that metabolites satisfying the necessary condition are present in metabolic networks from diverse species, suggesting prevalence of this property across kingdoms of life. We also demonstrate that our predictions about concentration robustness of energy-related metabolites are in line with experimental evidence from Escherichia coli. The necessary condition is applicable to mass action biological systems of arbitrary size, and will enable understanding the implications of concentration robustness in genetic engineering strategies and medical applications.

A network property necessary for concentration robustness.

PubMed

Eloundou-Mbebi, Jeanne M O; Küken, Anika; Omranian, Nooshin; Kleessen, Sabrina; Neigenfind, Jost; Basler, Georg; Nikoloski, Zoran

2016-10-19

Maintenance of functionality of complex cellular networks and entire organisms exposed to environmental perturbations often depends on concentration robustness of the underlying components. Yet, the reasons and consequences of concentration robustness in large-scale cellular networks remain largely unknown. Here, we derive a necessary condition for concentration robustness based only on the structure of networks endowed with mass action kinetics. The structural condition can be used to design targeted experiments to study concentration robustness. We show that metabolites satisfying the necessary condition are present in metabolic networks from diverse species, suggesting prevalence of this property across kingdoms of life. We also demonstrate that our predictions about concentration robustness of energy-related metabolites are in line with experimental evidence from Escherichia coli. The necessary condition is applicable to mass action biological systems of arbitrary size, and will enable understanding the implications of concentration robustness in genetic engineering strategies and medical applications.

A network property necessary for concentration robustness

PubMed Central

Eloundou-Mbebi, Jeanne M. O.; Küken, Anika; Omranian, Nooshin; Kleessen, Sabrina; Neigenfind, Jost; Basler, Georg; Nikoloski, Zoran

2016-01-01

Maintenance of functionality of complex cellular networks and entire organisms exposed to environmental perturbations often depends on concentration robustness of the underlying components. Yet, the reasons and consequences of concentration robustness in large-scale cellular networks remain largely unknown. Here, we derive a necessary condition for concentration robustness based only on the structure of networks endowed with mass action kinetics. The structural condition can be used to design targeted experiments to study concentration robustness. We show that metabolites satisfying the necessary condition are present in metabolic networks from diverse species, suggesting prevalence of this property across kingdoms of life. We also demonstrate that our predictions about concentration robustness of energy-related metabolites are in line with experimental evidence from Escherichia coli. The necessary condition is applicable to mass action biological systems of arbitrary size, and will enable understanding the implications of concentration robustness in genetic engineering strategies and medical applications. PMID:27759015

Effect of a protein-rich meal on urinary and salivary free amino acid concentrations in human subjects.

PubMed

Brand, H S; Jörning, G G; Chamuleau, R A; Abraham-Inpijn, L

1997-08-08

The aim of the present study was to investigate whether in healthy volunteers acute changes in plasma free amino acid composition after a protein-rich test meal are reflected in the urinary and salivary concentrations of the corresponding amino acids. The ingestion of a protein-rich meal elicited a significant increase of plasma and urine amino acid concentrations. The postprandial salivary amino acid excretion showed only minor changes. For several amino acids (alanine, arginine, asparagine, glycine, threonine and valine) significant relations were observed between the increase in concentration of these amino acids in venous plasma and urine. In whole saliva, only threonine and valine showed a significant relationship with the corresponding plasma concentration. Our data suggest that the urinary amino acid excretion of several amino acids has the potential for estimating short-term changes in plasma concentrations. Determination of salivary amino acid concentrations seems less appropriate for this purpose.

Widespread, routine occurrence of pharmaceuticals in sewage effluent, combined sewer overflows and receiving waters.

PubMed

Kay, Paul; Hughes, Stephen R; Ault, James R; Ashcroft, Alison E; Brown, Lee E

2017-01-01

Research addressing the occurrence, fate and effects of pharmaceuticals in the aquatic environment has expanded rapidly over the past two decades, primarily due to the development of improved chemical analysis methods. Significant research gaps still remain, however, including a lack of longer term, repeated monitoring of rivers, determination of temporal and spatial changes in pharmaceutical concentrations, and inputs from sources other than wastewater treatment plants (WWTPs), such as combined sewer overflows (CSOs). In addressing these gaps it was found that the five pharmaceuticals studied were routinely (51-94% of the time) present in effluents and receiving waters at concentrations ranging from single ng to μg L -1 . Mean concentrations were in the tens to hundreds ng L -1 range and CSOs appear to be a significant source of pharmaceuticals to water courses in addition to WWTPs. Receiving water concentrations varied throughout the day although there were no pronounced peaks at particular times. Similarly, concentrations varied throughout the year although no consistent patterns were observed. No dissipation of the study compounds was found over a 5 km length of river despite no other known inputs to the river. In conclusion, pharmaceuticals are routinely present in semi-rural and urban rivers and require management alongside more traditional pollutants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Lack of increase of serum adiponectin concentrations with a moderate weight loss during six months on a high-caloric diet in military service among a young male Finnish population.

PubMed

Mousavinasab, Firoozeh; Tähtinen, Tuula; Jokelainen, Jari; Koskela, Pentti; Vanhala, Mauno; Oikarinen, Jorma; Keinänen-Kiukaanniemi, Sirkka

2005-02-01

An increase of insulin resistance and a worsening of lipid profile during 6 mo of military service in young male Finnish population has previously been shown by us. The present study demonstrates unfavorable changes of serum adiponectin concentrations and their association with weight loss in these particular circumstances. Adiponectin in a range of 4.3-21.2 microg/mL was present in the serum samples and had a significant negative correlation with weight, body mass index, waist to hip ratio, and insulin. Fasting serum lipids and plasma insulin significantly increased and serum adiponectin levels significantly decreased during the military service. Even the subjects with a 5-10% decrease in body weight showed the same result. In cases with more than 10% weight reduction and a significant decrease of fasting insulin concentration, the total and low density lipoprotein cholesterol significantly increased and adiponectin concentration tended to decreased. Only in severely obese cases (BMI >/= 30 kg/m2) with more than 10% decrease in body mass index adiponectin levels tended to increase, although not statistically significantly. This study shows that serum adiponectin concentrations decreased during a 6 mo high-caloric diet in military service, and even a moderate weight reduction induced by high-energy expenditure in exercise during service did not increase its levels.

Occupational Exposure to Polycyclic Aromatic Hydrocarbons in Polish Coke Plant Workers.

PubMed

Zając, Joanna; Gomółka, Ewa; Maziarz, Barbara; Szot, Wojciech

2016-11-01

Assessment of occupational exposure to polycyclic aromatic hydrocarbons (PAHs) is an urgent and important task to prevent workers' illnesses. 1-Hydroxypyrene is one of the most commonly used biomarkers. The presented study assessed exposure to PAHs molecules among 619 individuals, men working in coke plant. Average number of years spent on working posts in exposition to PAHs was 31.5 years with standard deviation = 5.3. About 35% were smokers with 14.7 cigarettes per day. For each individual, 1-hydroxypyrene concentration in urine samples was measured. Urine 1-hydroxypyrene concentration correlated with air PAHs concentration. Difference between smokers and non-smokers was statistically significant. The median value for post-shift samples was 1.3 µg g -1 and for pre-shift sample concentration reached 0.3 µg g -1 Maximal assessed concentration was 7.6 µg g -1 among pre-shift samples and 27.8 µg g -1 among post-shift samples. The most exposed working posts were coke oven workers and coal derivatives production workers. Results obtained in presented study are relatively low in comparison to other countries or other Polish results but for further improvement a regular measurement of any PAHs' biomarker should be included to standard periodic health examinations for coke plant workers. © The Author 2016. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Aldosterone concentrations in saliva reflect the duration and severity of depressive episode in a sex dependent manner.

PubMed

Segeda, V; Izakova, L; Hlavacova, N; Bednarova, A; Jezova, D

2017-08-01

Evidence is accumulating that aldosterone may exert central actions and influence mental functions. The aim of the present study was to test the hypothesis that major depressive disorder affects the diurnal variation of salivary aldosterone and that aldosterone concentrations reflect the duration and severity of the depressive episode in a sex dependent manner. The sample consisted of 60 patients (37 postmenopausal women, 23 men) with major depressive disorder. Patients were examined two times, in acute depressive episode (admission to the hospital) and after reaching clinical remission (discharge). The samples of saliva were taken by the patients themselves twice a day (8.00-9.00 h in the morning and in the evening). Aldosterone concentrations were significantly higher in women compared to men and were significantly higher at the time of admission to the hospital compared to those at the discharge. Morning but not evening salivary aldosterone concentrations reflected the length of the depressive episode in women as well as the severity of the disorder in both sexes. Moreover, the patients with depression failed to exert known daily rhythmicity of aldosterone release. The present study brings several pieces of evidence suggesting the association of aldosterone with the pathophysiology of depression. Salivary aldosterone concentrations appear to reflect the outcome, the duration and the severity of the depressive episode in a sex dependent manner. Copyright © 2017 Elsevier Ltd. All rights reserved.

Legacy and alternative halogenated flame retardants in human milk in Europe: Implications for children's health.

PubMed

Čechová, Eliška; Vojta, Šimon; Kukučka, Petr; Kočan, Anton; Trnovec, Tomáš; Murínová, Ľubica Palkovičová; de Cock, Marijke; van de Bor, Margot; Askevold, Joakim; Eggesbø, Merete; Scheringer, Martin

2017-11-01

In this study, 10 polybrominated diphenyl ethers (PBDEs) and 19 alternative halogenated flame retardants (AFRs) were determined in >450 human milk samples across three European countries, representing northern, western and eastern Europe. This study provides first insights into the occurrence of selected AFRs in mother milk samples and compares them among three European countries. Sums of median concentrations of the most frequently detected PBDEs were 2.16, 0.88 and 0.45ngg -1 lipid weight (lw) in Norway, the Netherlands and Slovakia, respectively. The sum of the concentrations of AFRs ranged from 0.14 to 0.25ngg -1 lw in all countries, which was 2 to 15 times less compared to Σ 7 PBDEs. The Penta-BDE replacement, bis(2-ethylhexyl) tetrabromophthalate, BEH-TEBP, was present at the greatest concentrations of any of the AFRs and in some samples exceeded concentrations of BDE 47 and BDE 153. Four AFRs including bromobenzenes (hexabromobenzene, pentabromobenzene, pentabromotoluene) and another Penta-BDE replacement (2-ethylhexyl-2,3,4,5-tetrabromobenzoate, EH-TBB) were detected in >42% of all human milk samples. Because of the potential developmental neurotoxicity of the halogenated flame retardants, infant dietary intakes via breastfeeding were estimated; in four cases the intakes of BDE 47 exceeded the reference dose indicating that the present concentrations may pose a risk for children. Copyright © 2017 Elsevier Ltd. All rights reserved.

Post World War II orcharding creates present day DDT-problems in The Sørfjord (Western Norway)--a case study.

PubMed

Ruus, Anders; Green, Norman W; Maage, Amund; Amundsen, Carl Einar; Schøyen, Merete; Skei, Jens

2010-10-01

The Sørfjord has a long history of agriculture and industry, and environmental monitoring has been conducted for decades, comprising analyses of contaminants in mussel, fish and sediments. DDT was used as an insecticide in orchards surrounding the fjord between World War II and 1970. Since the early 1990 s, elevated concentrations of DDT were found in mussels and fish. Unexpectedly, DDT-concentrations increased towards present day, despite the discontinuation of use. The highest concentrations in mussels (in 2006) corresponded to about two orders of magnitude higher than background. Analyses of sediment core sections also indicated increased input towards present day. Shifts in climatic parameters, as well as increased amounts of soil dissolved organic carbon following a decline in atmospheric sulphate deposition may have contributed to this phenomenon. We warrant the need for increased knowledge of the effects of alterations in variables acting regionally and globally on the disposition of contaminants in ecosystems. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

Hayat, T.; Nonlinear Analysis and Applied Mathematics; Muhammad, Taseer

Development of human society greatly depends upon solar energy. Heat, electricity and water from nature can be obtained through solar power. Sustainable energy generation at present is a critical issue in human society development. Solar energy is regarded one of the best sources of renewable energy. Hence the purpose of present study is to construct a model for radiative effects in three-dimensional of nanofluid. Flow of second grade fluid by an exponentially stretching surface is considered. Thermophoresis and Brownian motion effects are taken into account in presence of heat source/sink and chemical reaction. Results are derived for the dimensionless velocities,more » temperature and concentration. Graphs are plotted to examine the impacts of physical parameters on the temperature and concentration. Numerical computations are presented to examine the values of skin-friction coefficients, Nusselt and Sherwood numbers. It is observed that the values of skin-friction coefficients are more for larger values of second grade parameter. Moreover the radiative effects on the temperature and concentration are quite reverse.« less

Dynamics of emulsification and demulsification of water in crude oil emulsions

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

Bhardwaj, A.; Hartland, S.

1994-05-01

The effect of aging on the crude oil/water interface has been studied, and the slow buildup of natural surfactants present in the crude oil at the interface was observed. Interfacial tension data and microvideography were used to evaluate the buildup of surface concentration. The methodology adopted in this work permits the calculation of the actual surface excess of natural surfactants at the crude oil/water interface, without having to isolate them from the crude oil and without knowing their bulk molar concentration. The rate of adsorption of demulsifier at the interface was determined by measurement of the dynamic interfacial tension bymore » a microprocessor-controlled drop volume method apparatus. Temperature, concentration, and nature of the medium (crude oil or brine) were found to be very important parameters governing adsorption of demulsifier at the interface. Diffusion of the emulsifier to the oil/water interface was much slower when demulsifier was present in the oil phase than when it was present in the water phase.« less

External concentration of organic acid anions and pH: key independent variables for studying how organic acids inhibit growth of bacteria in mildly acidic foods.

PubMed

Carpenter, C E; Broadbent, J R

2009-01-01

Although the mechanisms by which organic acids inhibit growth of bacteria in mildly acidic foods are not fully understood, it is clear that intracellular accumulation of anions is a primary contributor to inhibition of bacterial growth. We hypothesize that intracellular accumulation of anions is driven by 2 factors, external anion concentration and external acidity. This hypothesis follows from basic chemistry principles that heretofore have not been fully applied to studies in the field, and it has led us to develop a novel approach for predicting internal anion concentration by controlling the external concentration of anions and pH. This approach overcomes critical flaws in contemporary experimental design that invariably target concentration of either protonated acid or total acid in the growth media thereby leaving anion concentration to vary depending on the pK(a) of the acids involved. Failure to control external concentration of anions has undoubtedly confounded results, and it has likely led to misleading conclusions regarding the antimicrobial action of organic acids. In summary, we advocate an approach for directing internal anion levels by controlling external concentration of anions and pH because it presents an additional opportunity to study the mechanisms by which organic acids inhibit bacterial growth. Knowledge gained from such studies would have important application in the control of important foodborne pathogens such as Listeria monocytogenes, and may also facilitate efforts to promote the survival in foods or beverages of desirable probiotic bacteria.

[Determination of chromphoric dissolved organic matter in water from different sources].

PubMed

Liu, Xian-ping; Li, Lei; Dai, Jin-feng; Wang, Xiao-ru; Lee, Frank S C

2007-10-01

Chromophoric dissolved organic matter (CDOM) represents the fraction of the dissolved organic pool which absorbs light in the visible as well as UV ranges. It could affect the color of the waters. It is necessary to study it during in research on ecosystem, remote sensing of the water color and the cycle of carbon in waters. CDOM can fluoresce when excited, so fluorescence spectrum has been used to study its origin, distribution, and change. In the present article the fluorescence spectrophotometer was used to study the relation between the fluorescence intensity, spectrum area and the concentration of CDOM. When the concentration of CDOM is low (less than 75 mg x L(-1)), there is a better linear relationship (r2 > 0.98) between the fluorescence intensity, the spectrum area and the concentration of CDOM. Meanwhile good linear relations were found between the fluorescence intensity and spectrum area, which showed the same changeable trend of the fluorescence intensity and spectrum area with the concentration change of CDOM. A method was established to quantify the concentration of CDOM in water from different source using the linear relationship between the spectrum area and the concentration. It suits the complicated constituent analysis of CDOM and could really and accurately show the concentration of CDOM in natural water.

Contaminant concentration in environmental samples using LIBS and CF-LIBS

NASA Astrophysics Data System (ADS)

Pandhija, S.; Rai, N. K.; Rai, A. K.; Thakur, S. N.

2010-01-01

The present paper deals with the detection and quantification of toxic heavy metals like Cd, Co, Pb, Zn, Cr, etc. in environmental samples by using the technique of laser-induced breakdown spectroscopy (LIBS) and calibration-free LIBS (CF-LIBS). A MATLABTM program has been developed based on the CF-LIBS algorithm given by earlier workers and concentrations of pollutants present in industrial area soil have been determined. LIBS spectra of a number of certified reference soil samples with varying concentrations of toxic elements (Cd, Zn) have been recorded to obtain calibration curves. The concentrations of Cd and Zn in soil samples from the Jajmau area, Kanpur (India) have been determined by using these calibration curves and also by the CF-LIBS approach. Our results clearly demonstrate that the combination of LIBS and CF-LIBS is very useful for the study of pollutants in the environment. Some of the results have also been found to be in good agreement with those of ICP-OES.

Environmental modulation of microcystin and β-N-methylamino-L-alanine as a function of nitrogen availability.

PubMed

Scott, L L; Downing, S; Phelan, R R; Downing, T G

2014-09-01

The most significant modulators of the cyanotoxins microcystin and β-N-methylamino-L-alanine in laboratory cyanobacterial cultures are the concentration of growth-medium combined nitrogen and nitrogen uptake rate. The lack of field studies that support these observations led us to investigate the cellular content of these cyanotoxins in cyanobacterial bloom material isolated from a freshwater impoundment and to compare these to the combined nitrogen availability. We established that these toxins typically occur in an inverse relationship in nature and that their presence is mainly dependent on the environmental combined nitrogen concentration, with cellular microcystin present at exogenous combined nitrogen concentrations of 29 μM and higher and cellular BMAA correlating negatively with exogenous nitrogen at concentrations below 40 μM. Furthermore, opposing nutrient and light gradients that form in dense cyanobacterial blooms may result in both microcystin and BMAA being present at a single sampling site. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analytical model of chemical phase and formation of DSB in chromosomes by ionizing radiation.

PubMed

Barilla, Jiří; Lokajíček, Miloš; Pisaková, Hana; Simr, Pavel

2013-03-01

Mathematical analytical model of the processes running in individual radical clusters during the chemical phase (under the presence of radiomodifiers) proposed by us earlier has been further developed and improved. It has been applied to the data presented by Blok and Loman characterizing the oxygen effect in SSB and DSB formation (in water solution and at low-LET radiation) also in the region of very small oxygen concentrations, which cannot be studied with the help of experiments done with living cells. In this new analysis the values of all reaction rates and diffusion parameters known from literature have been made use of. The great increase of SSB and DSB at zero oxygen concentration may follow from the fact that at small oxygen concentrations the oxygen absorbs other radicals while at higher concentrations the formation of oxygen radicals prevails. It explains the double oxygen effect found already earlier by Ewing. The model may be easily extended to include also the effects of other radiomodifiers present in medium during irradiation.

Academic self-concept of ability and cortisol reactivity.

PubMed

Minkley, N; Westerholt, D M; Kirchner, W H

2014-05-01

The present study aimed to clarify the relationship between a school-specific trait (academic self-concept of ability [ASCA]) and hormonal stress response by using a trait-compatible stressor (test). First, we determined 52 students' ASCA scores for biology and measured their salivary cortisol concentration before and after a biology test (experimental group, n=28) or a free writing task (control group, n=24). For participants who took the test, statistical analysis indicated a significant negative correlation between ASCA score and cortisol response. In contrast, the control group showed a decrease in cortisol concentrations between test times and no correlation between cortisol concentration and ASCA scores were found. These findings indicated an interaction between ASCA scores and hormonal stress response when an academic-related stressor is present. Furthermore, these variables might influence each other adversely: high cortisol concentrations during a test situation may lead to greater feelings of insecurity, resulting in low ASCA scores and awareness of these low scores may lead to a further increase in cortisol, creating a vicious cycle.

Levels and distribution of polybrominated diphenyl ethers and organochlorine compounds in sea turtles from Japan.

PubMed

Malarvannan, Govindan; Takahashi, Shin; Isobe, Tomohiko; Kunisue, Tatsuya; Sudaryanto, Agus; Miyagi, Toshihiko; Nakamura, Masaru; Yasumura, Shigeki; Tanabe, Shinsuke

2011-01-01

Three species of sea turtles (green, hawksbill and loggerhead turtles) stranded along the coasts or caught (by-catch) around Ishigaki Island and Kochi, Japan were collected between 1998 and 2006 and analyzed for six organohalogen compounds viz., PBDEs, PCBs, DDTs, CHLs, HCHs and HCB. The present study is the first and foremost to report the occurrence of organohalogen compounds in the sea turtles from Japan. Among the compounds analyzed, concentrations of PCBs, DDTs and CHLs were the highest in all the turtle samples. PBDEs were ubiquitously present in all the turtle species. Comparing with the other two species, concentrations of organohalogens in green turtle were relatively low and decreasing trend in the concentrations were noted with increasing carapace length. Concentrations of OCs in sea turtles from the coasts of Ishigaki Island and Kochi were relatively low as compared to those from other locations in the world. Copyright © 2011 Elsevier Ltd. All rights reserved.

Synthesis and anti-microbial potencies of 1-(2-hydroxyethyl)-3-alkylimidazolium chloride ionic liquids: microbial viabilities at different ionic liquids concentrations.

PubMed

Hossain, M Ismail; El-Harbawi, Mohanad; Alitheen, Noorjahan Banu Mohamed; Noaman, Yousr Abdulhadi; Lévêque, Jean-Marc; Yin, Chun-Yang

2013-01-01

Three 1-(2-hydroxyethyl)-3-alkylimidazolium chloride room temperature ionic liquids (ILs) [2OHimC(n)][Cl]; (n=0, 1, 4) have been synthesized from the appropriate imidazole precursors and characterized by IR and NMR spectroscopies and elemental analysis. Their anti-microbial activities were investigated using the well-diffusion method. The viabilities of Escherichia coli, Aeromonas hydrophila, Listeria monocytogenes and Salmonella enterica as a function of IL concentrations were studied. The minimal inhibitory concentrations (MICs) and EC₅₀ values for the present ILs were within the concentration range from 60 to 125 mM and 23 to 73 mM. The anti-microbial potencies of the present ILs were compared to a standard antibiotic, gentamicin. The finding affords additional perspective on the level of ILs toxicity to aquatic lifeforms and yet, this characteristic can be readily harnessed to detect microbial growth and activity. Copyright © 2012 Elsevier Inc. All rights reserved.

Estimating in vivo airway surface liquid concentration in trials of inhaled antibiotics.

PubMed

Hasan, M A; Lange, C F

2007-01-01

Antibiotic drugs exhibit concentration dependence in their efficacy. Therefore, ensuring appropriate concentration of these drugs in the relevant body fluid is important for obtaining the desired therapeutic and physiological action. Until recently there had been no suitable method available to measure or estimate concentration of drugs in the human airways resulting from inhaled aerosols or to determine the amount of inhaled antibiotics required to ensure minimum inhibitory concentration of a drug in the airway surface liquid (ASL). In this paper a numerical method is used for estimating local concentration of inhaled pharmaceutical aerosols in different generations of the human tracheobronchial airways. The method utilizes a mathematical lung deposition model to estimate amounts of aerosols depositing in different lung generations, and a recent ASL model along with deposition results to assess the concentration of deposited drugs immediately following inhalation. Examples of concentration estimates for two case studies: one for the antibiotic tobramycin against Pseudomonas aeruginosa, and another for taurolidine against Burkholderia cepacia are presented. The aerosol characteristics, breathing pattern and properties of nebulized solutions were adopted from two recent clinical studies on efficacy of these drugs in cystic fibrosis (CF) patients and from other sources in the literature. While the clinically effective tobramycin showed a concentration higher than the required in vivo concentration, that for the ineffective taurolidine was found to be below the speculated required in vivo concentration. Results of this study thus show that the mathematical ASL model combined with the lung deposition model can be an effective tool for helping decide the optimum dosage of inhaled antibiotic drugs delivered during human clinical trials.

High-sensitivity cardiac troponin I at presentation in patients with suspected acute coronary syndrome: a cohort study.

PubMed

Shah, Anoop S V; Anand, Atul; Sandoval, Yader; Lee, Kuan Ken; Smith, Stephen W; Adamson, Philip D; Chapman, Andrew R; Langdon, Timothy; Sandeman, Dennis; Vaswani, Amar; Strachan, Fiona E; Ferry, Amy; Stirzaker, Alexandra G; Reid, Alan; Gray, Alasdair J; Collinson, Paul O; McAllister, David A; Apple, Fred S; Newby, David E; Mills, Nicholas L

2015-12-19

Suspected acute coronary syndrome is the commonest reason for emergency admission to hospital and is a large burden on health-care resources. Strategies to identify low-risk patients suitable for immediate discharge would have major benefits. We did a prospective cohort study of 6304 consecutively enrolled patients with suspected acute coronary syndrome presenting to four secondary and tertiary care hospitals in Scotland. We measured plasma troponin concentrations at presentation using a high-sensitivity cardiac troponin I assay. In derivation and validation cohorts, we evaluated the negative predictive value of a range of troponin concentrations for the primary outcome of index myocardial infarction, or subsequent myocardial infarction or cardiac death at 30 days. This trial is registered with ClinicalTrials.gov (number NCT01852123). 782 (16%) of 4870 patients in the derivation cohort had index myocardial infarction, with a further 32 (1%) re-presenting with myocardial infarction and 75 (2%) cardiac deaths at 30 days. In patients without myocardial infarction at presentation, troponin concentrations were less than 5 ng/L in 2311 (61%) of 3799 patients, with a negative predictive value of 99·6% (95% CI 99·3-99·8) for the primary outcome. The negative predictive value was consistent across groups stratified by age, sex, risk factors, and previous cardiovascular disease. In two independent validation cohorts, troponin concentrations were less than 5 ng/L in 594 (56%) of 1061 patients, with an overall negative predictive value of 99·4% (98·8-99·9). At 1 year, these patients had a lower risk of myocardial infarction and cardiac death than did those with a troponin concentration of 5 ng/L or more (0·6% vs 3·3%; adjusted hazard ratio 0·41, 95% CI 0·21-0·80; p<0·0001). Low plasma troponin concentrations identify two-thirds of patients at very low risk of cardiac events who could be discharged from hospital. Implementation of this approach could substantially reduce hospital admissions and have major benefits for both patients and health-care providers. British Heart Foundation and Chief Scientist Office (Scotland). Copyright © 2015 Shah et al. Open Access article distributed under the terms of CC BY-NC-ND. Published by Elsevier Ltd.. All rights reserved.

Diffusion via space discretization method to study the concentration dependence of self-diffusivity under confinement

NASA Astrophysics Data System (ADS)

Sant, Marco; Papadopoulos, George K.; Theodorou, Doros N.

2010-04-01

The concentration dependence of self-diffusivity is investigated by means of a novel method, extending our previously developed second-order Markov process model to periodic media. Introducing the concept of minimum-crossing surface, we obtain a unique decomposition of the self-diffusion coefficient into two parameters with specific physical meanings. Two case studies showing a maximum in self-diffusivity as a function of concentration are investigated, along with two cases where such a maximum cannot be present. Subsequently, the method is applied to the large cavity pore network of the ITQ-1 (Mobil tWenty tWo, MWW) zeolite for methane (displaying a maximum in self-diffusivity) and carbon dioxide (no maximum), explaining the diffusivity trend on the basis of the evolution of the model parameters as a function of concentration.

The effect of febuxostat to prevent a further reduction in renal function of patients with hyperuricemia who have never had gout and are complicated by chronic kidney disease stage 3: study protocol for a multicenter randomized controlled study

PubMed Central

2014-01-01

Background Hyperuricemia is a risk factor for the onset of chronic kidney disease (CKD) and is significantly associated with the progression of CKD. However, there is no sufficient evidence by interventional research supporting a cause-effect relationship. Hyperuricemic patients without gouty arthritis, whose serum urate (SUA) concentration is ≥8.0 mg/dL and who have a complication, are treated by pharmacotherapy in addition to lifestyle guidance. Nevertheless, there is no evidence that rationalizes pharmacotherapy for patients with hyperuricemia who have no complication and whose SUA concentration is below 9.0 mg/dL. Methods/Design The FEATHER (FEbuxostat versus placebo rAndomized controlled Trial regarding reduced renal function in patients with Hyperuricemia complicated by chRonic kidney disease stage 3) study is a prospective, multicenter, double-blind, randomized, placebo-controlled trial of febuxostat—a novel, nonpurine, selective, xanthine oxidase inhibitor. The present study will enroll, at 64 medical institutions in Japan, 400 Japanese patients aged 20 years or older who have hyperuricemia without gouty arthritis, who present CKD stage 3, and whose SUA concentration is 7.1-10.0 mg/dL. Patients are randomly assigned to either the febuxostat or the control group, in which febuxostat tablets and placebo are administered orally, respectively. The dosage of the study drugs should be one 10-mg tablet/day at weeks 1 to 4 after study initiation, increased to one 20-mg tablet/day at weeks 5 to 8, and elevated to one 40-mg tablet/day at week 9 and then maintained until week 108. The primary endpoint is estimated glomerular filtration rate (eGFR) slope. The secondary endpoints include the amount and percent rate of change in eGFR from baseline to week 108, the amount and percent rate of change in SUA concentration from baseline to week 108, the proportion of patients who achieved an SUA concentration ≤6.0 mg/dL, and the incidence of renal function deterioration. Discussion The present study aims to examine whether febuxostat prevents a further reduction in renal function as assessed with eGFR in subjects and will (1) provide evidence to indicate the inverse association between a reduction in SUA concentration and an improvement in renal function and (2) rationalize pharmacotherapy for subjects and clarify its clinical relevance. Trial registration UMIN Identifier: UMIN000008343 PMID:24433285

Methods to reduce the CO(2) concentration of educational buildings utilizing internal ventilation by transferred air.

PubMed

Kalema, T; Viot, M

2014-02-01

The aim of this study is to develop internal ventilation by transferred air to achieve a good indoor climate with low energy consumption in educational buildings with constant air volume (CAV) ventilation. Both measurements of CO2 concentration and a multi-room calculation model are presented. The study analyzes how to use more efficiently the available spaces and the capacity of CAV ventilation systems in existing buildings and the impact this has on the indoor air quality and the energy consumption of the ventilation. The temperature differences can be used to create natural ventilation airflows between neighboring spaces. The behavior of temperature-driven airflows between rooms was studied and included in the calculation model. The effect of openings between neighboring spaces, such as doors or large apertures in the walls, on the CO2 concentration was studied in different classrooms. The air temperatures and CO2 concentrations were measured using a wireless, internet-based measurement system. The multi-room calculation model predicted the CO2 concentration in the rooms, which was then compared with the measured ones. Using transferred air between occupied and unoccupied spaces can noticeably reduce the total mechanical ventilation rates needed to keep a low CO2 concentration. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Soil gas radon concentrations measurements in terms of great soil groups.

PubMed

Içhedef, Mutlu; Saç, Müslim Murat; Camgöz, Berkay; Bolca, Mustafa; Harmanşah, Çoşkun

2013-12-01

In this study, soil gas radon concentrations were investigated according to locations, horizontal soil layers and great soil groups around Tuzla Fault, Seferihisar-İzmir. Great soil groups are a category that described the horizontal soil layers under soil classification system and distributions of radon concentration in the great soil groups are firstly determined by the present study. According to the obtained results, it has been showed that the radon concentrations in the Koluvial soil group are higher than the other soil groups in the region. Also significant differences on location in same great soil group were determined. The radon concentrations in the Koluvial soil groups were measured with respect to soil layers structures (A, B, C1, and C2). It has been observed that the values increase with depth of soil (C2>C1>B>A). The main reason may be due to the meteorological factors that have limited effect on radon escape from deep layers. Although fault lines pass thought the study area radon concentrations were varied location to location, layer to layer and great group to great group. The study shows that a detailed location description should be performed before soil radon measurements for earthquake predictions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Relationship between acetaldehyde concentration in mouth air and tongue coating volume.

PubMed

Yokoi, Aya; Maruyama, Takayuki; Yamanaka, Reiko; Ekuni, Daisuke; Tomofuji, Takaaki; Kashiwazaki, Haruhiko; Yamazaki, Yutaka; Morita, Manabu

2015-01-01

Acetaldehyde is the first metabolite of ethanol and is produced in the epithelium by mucosal ALDH, while higher levels are derived from microbial oxidation of ethanol by oral microflora such as Candida species. However, it is uncertain whether acetaldehyde concentration in human breath is related to oral condition or local production of acetaldehyde by oral microflora. The aim of this pilot study was to investigate the relationship between physiological acetaldehyde concentration and oral condition in healthy volunteers. Sixty-five volunteers (51 males and 14 females, aged from 20 to 87 years old) participated in the present study. Acetaldehyde concentration in mouth air was measured using a portable monitor. Oral examination, detection of oral Candida species and assessment of alcohol sensitivity were performed. Acetaldehyde concentration [median (25%, 75%)] in mouth air was 170.7 (73.5, 306.3) ppb. Acetaldehyde concentration in participants with a tongue coating status score of 3 was significantly higher than in those with a score of 1 (p<0.017). After removing tongue coating, acetaldehyde concentration decreased significantly (p<0.05). Acetaldehyde concentration was not correlated with other clinical parameters, presence of Candida species, smoking status or alcohol sensitivity. Physiological acetaldehyde concentration in mouth air was associated with tongue coating volume.

Relationship between acetaldehyde concentration in mouth air and tongue coating volume

PubMed Central

YOKOI, Aya; MARUYAMA, Takayuki; YAMANAKA, Reiko; EKUNI, Daisuke; TOMOFUJI, Takaaki; KASHIWAZAKI, Haruhiko; YAMAZAKI, Yutaka; MORITA, Manabu

2015-01-01

Objective Acetaldehyde is the first metabolite of ethanol and is produced in the epithelium by mucosal ALDH, while higher levels are derived from microbial oxidation of ethanol by oral microflora such as Candida species. However, it is uncertain whether acetaldehyde concentration in human breath is related to oral condition or local production of acetaldehyde by oral microflora. The aim of this pilot study was to investigate the relationship between physiological acetaldehyde concentration and oral condition in healthy volunteers. Material and Methods Sixty-five volunteers (51 males and 14 females, aged from 20 to 87 years old) participated in the present study. Acetaldehyde concentration in mouth air was measured using a portable monitor. Oral examination, detection of oral Candida species and assessment of alcohol sensitivity were performed. Results Acetaldehyde concentration [median (25%, 75%)] in mouth air was 170.7 (73.5, 306.3) ppb. Acetaldehyde concentration in participants with a tongue coating status score of 3 was significantly higher than in those with a score of 1 (p<0.017). After removing tongue coating, acetaldehyde concentration decreased significantly (p<0.05). Acetaldehyde concentration was not correlated with other clinical parameters, presence of Candida species, smoking status or alcohol sensitivity. Conclusion Physiological acetaldehyde concentration in mouth air was associated with tongue coating volume. PMID:25760268

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.

Determination of heavy metal contents in water, sediments, and fish tissues of Shizothorax plagiostomus in river Panjkora at Lower Dir, Khyber Pakhtunkhwa, Pakistan.

PubMed

Ahmad, Kabir; Azizullah, Azizullah; Shama, Shama; Khattak, Muhammad Nasir Khan

2014-11-01

The present study was conducted to investigate the contamination of water, sediments, and fish tissues with heavy metals in river Panjkora at Lower Dir, Khyber Pakhtunkhwa, Pakistan. Water, sediments, and fish (Shizothorax plagiostomus) samples were collected from September 2012 to January 2013 at three different sites (upstream site at Sharigut, sewage site at Timergara, and downstream site at Sadoo) of river Panjkora. The concentrations of heavy metals in water were in the order Zn > Cu ≈ Pb > Ni ≈ Cd with mean values of 0.30, 0.01, 0.01, 0.0 and 0.0 mg/l, respectively, which were below the maximum permissible limits of WHO for drinking water. In sediments, heavy metals were found in the order Cu > Zn > Ni > Pb > Cd with mean concentrations of 50.6, 38.7, 9.3, 8, and 0.4 mg/kg, respectively. Ni and Cd were not found in any fish tissues, but Zn, Cu, and Pb were detected with the mean concentration ranges of 0.04-1.19, 0.03-0.12, and 0.01-0.09 μg/g, respectively. The present study demonstrates that disposal of waste effluents causes a slight increase in the concentration of heavy metals in river Panjkora as revealed by variation in metal concentrations from upstream to downstream site. Sewage disposal was also found to change physicochemical characteristics of Panjkora water. At present, water and fish of river Panjkora are safe for human consumption, but the continuous sewage disposal may create problems in the future.

Impact of nutritional recovery with linear growth on the concentrations of adipokines in undernourished children living in Brazilian slums.

PubMed

Martins, Vinicius J B; Neves, Andrea P O; Franco, Maria do C P; Clemente, Ana P G; Sawaya, Ana L

2014-09-28

Undernutrition in early life has been reported to be closely associated with the development of non-communicable diseases in adulthood. Adequate treatment is important for reversing these effects. In the present study, we investigated the effects of undernutrition and anthropometric recovery on the weights and heights of children in relation to the concentrations of leptin, adiponectin and plasminogen activator inhibitor-1 (PAI-1). A total of 119 children (aged 6-16 years) from the slums of São Paulo were selected according to their nutritional status and divided into three groups as follows: control (healthy without intervention, n 38) with a height-for-age Z score (HAZ) and a BMI-for-age Z score (BAZ) > -1·6; undernourished (HAZ and/or BAZ < -1·6, n 54); recovered from undernutrition (after treatment in a rehabilitation centre; HAZ and BAZ > -1·6, n 27). Blood samples were collected to determine insulin, glucose, leptin, adiponectin and PAI-1 concentrations. Leptin concentrations in the undernourished group were lower than those in the control and recovered groups (mean 0·92 (95% CI 0·67, 1·25), 2·03 (95% CI 1·46, 2·82) and 1·66 (95% CI 1·15, 2·44) ng/ml, P=0·003), which had similar leptin concentrations. There were no differences in adiponectin and PAI-1 concentrations among the groups. A positive correlation between waist circumference and leptin concentrations was observed in all the girls and boys of the control group (control: r 0·729, P<0·01; undernourished: r 0·490, P<0·05; and recovered: r 0·829, P<0·01; r 0·673, P<0·05). Stronger correlations between leptin and insulin concentrations were observed in the recovered group. The results of the present study indicate that normal leptin concentrations are found when normal height and weight are achieved.

The relationship of endogenous plasma concentrations of β-Hydroxy β-Methyl Butyrate (HMB) to age and total appendicular lean mass in humans.

PubMed

Kuriyan, Rebecca; Lokesh, Deepa P; Selvam, Sumithra; Jayakumar, J; Philip, Mamatha G; Shreeram, Sathyavageeswaran; Kurpad, Anura V

2016-08-01

The maintenance of muscle mass and muscle strength is important for reducing the risk of chronic diseases. The age- related loss of muscle mass and strength is associated with adverse outcomes of physical disability, frailty and death. β-Hydroxy β-Methyl Butyrate (HMB), a metabolite of leucine, has beneficial effects on muscle mass and strength under various catabolic conditions. The objectives of the present study were to determine if age- related differences existed in endogenous plasma HMB levels, and to assess if HMB levels correlated to total appendicular lean mass and forearm grip strength. Anthropometry, dietary and physical activity assessment, and the estimation of fasting plasma HMB concentrations and handgrip strength were performed on the 305 subjects (children, young adults and older adults). Lean mass, which serves as a surrogate for muscle mass was measured using dual energy X-ray absorptiometry (DEXA). Mean plasma HMB concentrations were significantly lower with increasing age groups, with children having highest mean HMB concentration (p<0.01) followed by young adults and older adults. Female subjects (across all ages) had significantly lower plasma HMB concentrations. A significant positive correlation between HMB concentrations and appendicular lean mass normalized for body weight (%), appendicular lean mass (r=0.37; p<0.001) was observed in the young adults and older adults group. Handgrip strength was positively associated with plasma HMB concentrations in young adults (r=0.58; p<0.01) and the older adults group (r=0.28; p<0.01). The findings of the present study suggest that there is an age- related decline in endogenous HMB concentrations in humans and the HMB concentrations were positively correlated with appendicular lean mass and hand grip strength in young adults and older adults group. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Do fossil plants signal palaeoatmospheric carbon dioxide concentration in the geological past?

PubMed Central

McElwain, J. C.

1998-01-01

Fossil, subfossil, and herbarium leaves have been shown to provide a morphological signal of the atmospheric carbon dioxide environment in which they developed by means of their stomatal density and index. An inverse relationship between stomatal density/index and atmospheric carbon dioxide concentration has been documented for all the studies to date concerning fossil and subfossil material. Furthermore, this relationship has been demonstrated experimentally by growing plants under elevated and reducedcarbon dioxide concentrations. To date, the mechanism that controls the stomatal density response to atmospheric carbon dioxide concentration remains unknown. However, stomatal parameters of fossil plants have been successfully used as a proxy indicator of palaeo-carbon dioxide levels. This paper presents new estimates of palaeo-atmospheric carbon dioxide concentrations for the Middle Eocene (Lutetian), based on the stomatal ratios of fossil Lauraceae species from Bournemouth in England. Estimates of atmospheric carbon dioxide concentrations derived from stomatal data from plants of the Early Devonian, Late Carboniferous, Early Permian and Middle Jurassic ages are reviewed in the light of new data. Semi-quantitative palaeo-carbon dioxide estimates based on the stomatal ratio (a ratio of the stomatal index of a fossil plant to that of a selected nearest living equivalent) have in the past relied on the use of a Carboniferous standard. The application of a new standard based on the present-day carbon dioxide level is reported here for comparison. The resultant ranges of palaeo-carbon dioxide estimates made from standardized fossil stomatal ratio data are in good agreement with both carbon isotopic data from terrestrial and marine sources and long-term carbon cycle modelling estimates for all the time periods studied. These data indicate elevated atmospheric carbon dioxide concentrations during the Early Devonian, Middle Jurassic and Middle Eocene, and reduced concentrations during the Late Carboniferous and Early Permian. Such data are important in demonstrating the long-term responses of plants to changing carbon dioxide concentrations and in contributing to the database needed for general circulation model climatic analogues.

Low concentrations of doxycycline attenuates FasL-induced apoptosis in HeLa cells.

PubMed

Yoon, Jung Mi; Koppula, Sushruta; Huh, Se Jong; Hur, Sun Jin; Kim, Chan Gil

2015-07-24

Doxycycline (DC) has been shown to possess non-antibiotic properties including Fas/Fas Ligand (FasL)-mediated apoptosis against several tumor types in the concentration range of 10-40 µg/mL. However, the effect of DC in apoptotic signaling at much low concentrations was not studied. The present study investigated the attenuation effect of low dose of DC on FasL-induced apoptosis in HeLa cell by the methods of MTT assay, fluorescence microscopy, DNA fragmentation, flow cytometry analysis, and western blotting. In the present findings we showed that low concentration of DC (<2.0 µg/mL) exhibited protective effects against FasL-induced apoptosis in HeLa cells. FasL treatment to HeLa cells resulted in a concentration-dependent induction of cell death, and treatment with low concentrations of DC (0.1-2 µg/mL) significantly (p < 0.001) attenuated the FasL-induced cell death as measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Further, the FasL-induced apoptotic features in HeLa cells, such as morphological changes, DNA fragmentation and cell cycle arrest was also inhibited by DC (0.5 µg/mL). Tetracycline and minocycline also showed similar anti-apoptotic effects but were not significant when compared to DC, tested at same concentrations. Further, DC (0.01-16 µg/mL) did not influence the hydrogen peroxide- or cisplatin-induced intrinsic apoptotic pathway in HeLa cells. Protein analysis using Western blotting confirmed that FasL-induced cleavage/activation of caspase-8 and caspase-3, were inhibited by DC treatment at low concentration (0.5 µg/mL). Considering the overall data, we report for the first time that DC exhibited anti-apoptotic effects at low concentrations in HeLa cells by inhibition of caspase activation via FasL-induced extrinsic pathway.

MCS precipitation and downburst intensity response to increased aerosol concentrations

NASA Astrophysics Data System (ADS)

Clavner, M.; Cotton, W. R.; van den Heever, S. C.

2015-12-01

Mesoscale convective systems (MCSs) are important contributors to rainfall in the High Plains of the United States as well as producers of severe weather such as hail, tornados and straight-line wind events known as derechos. Past studies have shown that changes in aerosol concentrations serving as cloud condensation nuclei (CCN) alter the MCS hydrometeor characteristics which in turn modify precipitation yield, downdraft velocity, cold-pool strength, storm propagation and the potential for severe weather to occur. In this study, the sensitivity of MCS precipitation characteristics and convective downburst velocities associated with a derecho to changes in CCN concentrations were examined by simulating a case study using the Regional Atmospheric Modeling System (RAMS). The case study of the 8 May 2009 "Super-Derecho" MCS was chosen since it produced a swath of widespread wind damage in association with an embedded large-scale bow echo, over a broad region from the High Plains of western Kansas to the foothills of the Appalachians. The sensitivity of the storm to changes in CCN concentrations was examined by conducting a set of three simulations which differed in the initial aerosol concentration based on output from the 3D chemical transport model, GEOS-Chem. Results from this study indicate that while increasing CCN concentrations led to an increase in precipitation rates, the changes to the derecho strength were not linear. A moderate increase in aerosol concentration reduced the derecho strength, while the simulation with the highest aerosol concentrations increased the derecho intensity. These changes are attributed to the impact of enhanced CCN concentration on the production of convective downbursts. An analysis of aerosol loading impacts on these MCS features will be presented.

Characteristics of airborne dust in the return airways of the mechanized longwall face

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

Gueyagueler, T.; Keskin, S.

1999-07-01

In this paper the results of a research study on the characterization of airborne dust in the return airway of the mechanized longwall face at Middle Anatolian Lignite Mine, OAL are presented. Dust, temperature, moisture and air velocity measurements are carried out in the return airways of the fully mechanized longwalls. Then the analyses of results on real-time concentration data, mass concentration data, effect of moisture, heat and air velocity on dust concentration are made. It has been found that amount of dust in return airway is directly related to the face activities and to the amount of settled dustmore » on the return airway. Moreover, the relationship between dust deposition rate and distance was studied. Another objective of this study is to determine the reliability of different dust samplers used in sampling. Comparison of results showed that for the lower dust concentration, there is not any significant differences between the measurements of samplers. But as the dust concentration exceeds 15 mg/m{sup 3}, the difference in measurements becomes significant.« less

Manufacturing Industries with High Concentrations of Scientists and Engineers Lead in 1965-77 Employment Growth. Science Resources Studies Highlights, April 20, 1979.

ERIC Educational Resources Information Center

National Science Foundation, Washington, DC. Div. of Science Resources Studies.

Presented are the results of a survey of over 100,000 manufacturing establishments, conducted for the National Science Foundation by the Bureau of Labor Statistics, covering average annual employment for calendar year 1977. Industries whose relative concentration of scientists and engineers was high in 1977, such as petroleum refining, chemicals,…

Micro-photoluminescence of GaAs/AlGaAs triple concentric quantum rings.

PubMed

Abbarchi, Marco; Cavigli, Lucia; Somaschini, Claudio; Bietti, Sergio; Gurioli, Massimo; Vinattieri, Anna; Sanguinetti, Stefano

2011-10-31

A systematic optical study, including micro, ensemble and time resolved photoluminescence of GaAs/AlGaAs triple concentric quantum rings, self-assembled via droplet epitaxy, is presented. Clear emission from localized states belonging to the ring structures is reported. The triple rings show a fast decay dynamics, around 40 ps, which is expected to be useful for ultrafast optical switching applications.

Ar + CO2 and He + CO2 Plasmas in ASTRAL

NASA Astrophysics Data System (ADS)

Boivin, R. F.; Gardner, A.; Munoz, J.; Kamar, O.; Loch, S.

2007-11-01

Spectroscopy study of the ASTRAL helicon plasma source running Ar + CO2 and He + CO2 gas mixes is presented. ASTRAL produces plasmas with the following parameters: ne = 10^10 - 10^13 cm-3, Te = 2 - 10 eV and Ti = 0.03 - 0.5 eV, B-field <= 1.3 kGauss, rf power <= 2 kWatt. A 0.33 m scanning monochromator is used for this study. Using Ar + CO2 gas mixes, very different plasmas are observed as the concentration of CO2 is changed. At low CO2 concentration, the bluish plasma is essentially atomic and argon transitions dominate the spectra. Weak C I and O I lines are present in the 750 - 1000 nm range. At higher CO2 concentration, the plasma becomes essentially molecular and is characterized by intense, white plasma columns. Here, spectra are filled with molecular bands (CO2, CO2^+, CO and CO^+). Limited molecular dissociative excitation processes associated with the production of C I and O I emission are also observed. On the other hand, He + CO2 plasmas are different. Here, rf matches are only possible at low CO2 concentration. Under these conditions, the spectra are characterized by strong C I and O I transitions with little or no molecular bands. Strong dissociative processes observed in these plasmas can be link to the high Te associated with He plasmas. An analysis of the spectra with possible scientific and industrial applications will be presented.

Neutral endopeptidase regulates neurogenic inflammatory responses induced by stimulation of human oral keratinocytes with bacterial lipopolysaccharide and nicotine.

PubMed

Nakata, Motoki; Awano, Shuji; Kinoshita, Naomasa; Yoshida, Akihiro; Ansai, Toshihiro

2013-10-01

Neutral endopeptidase (NEP) is present on various epithelial cells and inactivates numerous physiologically active peptides. Neutral endopeptidase may regulate proinflammatory signals in oral mucosal epithelium. However, the function of NEP in oral mucosal epithelium is unknown. The present study investigated the action of NEP upon proinflammatory signals on human oral keratinocytes and the influence of endothelin-converting enzyme (ECE)-1, an enzyme similar to NEP, on the functions of NEP. Oral keratinocytes were cultured in medium containing inflammatory inducers [lipopolysaccharide (LPS) and nicotine], NEP inhibitors, and ECE-1/NEP inhibitors, either alone or in combination. The concentrations of substance P (SP) and interleukin-1β (IL-1β) were measured in the supernatant. Additionally, the concentrations of SP and IL-1β were measured in the supernatant of cells incubated with LPS or nicotine after transfection with NEP small interfering RNA (siRNA). The concentrations of SP and IL-1β were significantly increased in cells incubated with NEP inhibitors and, to a lesser extent, in cells incubated with ECE-1/NEP inhibitors, compared with controls (cells incubated with LPS or nicotine alone). The concentrations of SP and IL-1β in cells transfected with NEP siRNA were significantly augmented compared with controls. In conclusion, the present study demonstrated that NEP down-regulated the levels of SP and IL-1β produced from human oral keratinocytes, although ECE-1 may be partly related to the down-regulation. © 2013 Eur J Oral Sci.

Dose-dependent effect of lysozyme upon Candida albicans biofilm

PubMed Central

Sebaa, Sarra; Hizette, Nicolas; Boucherit-Otmani, Zahia; Courtois, Philippe

2017-01-01

The present study investigated the in vitro effect of lysozyme (0–1,000 µg/ml) on Candida albicans (C. albicans) biofilm development. Investigations were conducted on C. albicans ATCC 10231 and on 10 clinical isolates from dentures. Strains were cultured aerobically at 37°C in Sabouraud broth. Yeast growth was evaluated by turbidimetry. Biofilm biomass was quantified on a polystyrene support by crystal violet staining and on acrylic surfaces by counts of colony forming units. Lysozyme affected biofilm formation to a greater extent than it affected growth. For the ATCC 10231 reference strain, lysozyme acted as a biofilm promotor on polystyrene at the highest concentration tested (1,000 µg/ml, non-physiological). When the reference strain was investigated on acrylic resin support, lysozyme acted as a significant biofilm promotor on rough resin, but less on smooth resin. The attached biomass in the presence of physiological concentrations of lysozyme (10–30 µg/ml) was significantly decreased compared with the hypothetical value of 100% using a one-sample t-test, but a comparison between the different lysozyme conditions using analysis of variance and post hoc tests did not reveal significant differences. In 10 wild strains, different patterns of biofilm formation on polystyrene were observed in the presence of lysozyme. Some strains, characterized by large amounts of biofilm formation in the presence of 1,000 µg/ml lysozyme, were poor biofilm producers at low concentrations of lysozyme. In contrast, some strains that were poor biofilm producers with a high lysozyme concentration were more inhibited by low concentrations of lysozyme. The present study emphasizes the need to develop strategies for biofilm control based on in vitro experiments, and to implement these in clinical trials prior to approval of hygiene products enriched with exocrine proteins, such as lysozyme. Further studies will extend these investigations to other Candida species, and to fungi and bacteria present in oral biofilms. PMID:28138698

A modelling exercise to examine variations of NOx concentrations on adjacent footpaths in a street canyon: The importance of accounting for wind conditions and fleet composition.

PubMed

Gallagher, J

2016-04-15

Personal measurement studies and modelling investigations are used to examine pollutant exposure for pedestrians in the urban environment: each presenting various strengths and weaknesses in relation to labour and equipment costs, a sufficient sampling period and the accuracy of results. This modelling exercise considers the potential benefits of modelling results over personal measurement studies and aims to demonstrate how variations in fleet composition affects exposure results (presented as mean concentrations along the centre of both footpaths) in different traffic scenarios. A model of Pearse Street in Dublin, Ireland was developed by combining a computational fluid dynamic (CFD) model and a semi-empirical equation to simulate pollutant dispersion in the street. Using local NOx concentrations, traffic and meteorological data from a two-week period in 2011, the model were validated and a good fit was presented. To explore the long-term variations in personal exposure due to variations in fleet composition, synthesised traffic data was used to compare short-term personal exposure data (over a two-week period) with the results for an extended one-year period. Personal exposure during the two-week period underestimated the one-year results by between 8% and 65% on adjacent footpaths. The findings demonstrate the potential for relative differences in pedestrian exposure to exist between the north and south footpaths due to changing wind conditions in both peak and off-peak traffic scenarios. This modelling approach may help overcome potential under- or over-estimations of concentrations in personal measurement studies on the footpaths. Further research aims to measure pollutant concentrations on adjacent footpaths in different traffic and wind conditions and to develop a simpler modelling system to identify pollutant hotspots on our city footpaths so that urban planners can implement improvement strategies to improve urban air quality. Copyright © 2016 Elsevier B.V. All rights reserved.

Dose-dependent inhibitory effects of zoledronic acid on osteoblast viability and function in vitro.

PubMed

Huang, Xin; Huang, Shilong; Guo, Fengjin; Xu, Fei; Cheng, Peng; Ye, Yaping; Dong, Yonghui; Xiang, Wei; Chen, Anmin

2016-01-01

Zoledronic acid (ZA), which is one of the most potent and efficacious bisphosphonates, has been commonly used in clinical practice for the treatment of various bone disorders. The extensive use of ZA has been associated with increasing occurrence of jaw complications, now known as bisphosphonate‑associated osteonecrosis of the jaw (BRONJ). However, the mechanism underlying BRONJ remains to be fully elucidated. The aim of the present study was to investigate the effects of different concentrations of ZA on the MC3T3‑E1 murine preosteoblast cell line cells and examine the possible pathogenesis of BRONJ. In the present study, the effect of ZA on the viability, apoptosis, differentiation and maturation of MC3T3‑E1 cells, as well as its relevant molecular mechanism, were examined The results of a Cell Counting Kit 8 assay, a flow cytometric Annexin‑V/propidium iodide assay and western blot analysis demonstrated that ZA exhibited a significant inhibition of cell viability and induction of apoptosis at concentrations >10 µM. Subsequently, the effect of ZA on cell differentiation at concentrations <1 µM were investigated. In this condition, ZA inhibited bone nodule formation and decreased the activity of alkaline phosphatase. The results of reverse transcription-quantitative polymerase chain reaction and western blot analyses indicated that ZA downregulated the expression levels of the marker genes and proteins associated with osteogenic differentiation. Further investigation revealed that the suppression of differentiation by ZA was associated with decreased expression of bone morphogenetic protein‑2 (BMP‑2) and downregulation of the phosphorylation levels in the downstream extracellular signal‑regulated kinase 1/2 and p38 pathways. These adverse effects of ZA were observed to be concentration‑dependent. The results from the present study suggested that ZA at higher concentrations induces cytotoxicity towards osteoblasts, and ZA at lower concentrations suppresses osteoblast differentiation by downregulation of BMP-2. These results assist in further understanding the mechanisms of BRONJ.

2,4-D abatement from groundwater samples by photo-Fenton processes at circumneutral pH using naturally iron present. Effect of inorganic ions.

PubMed

Gutiérrez-Zapata, Héctor M; Rojas, Karen L; Sanabria, Janeth; Rengifo-Herrera, Julián Andrés

2017-03-01

This study evaluated, at laboratory scale, if the using iron naturally present (0.3 mg L -1 ) and adding 10 mg L -1 of hydrogen peroxide was effective to remove 24.3 mgL -1 of 2,4-dichlorophenoxyacetic acid (2,4-D) from groundwater samples by simulated solar irradiation (global intensity = 300 W m -2 ). Under these conditions, the degradation of 2,4-D reached 75.2 % and the apparition of its main oxidation byproduct 2,4-dichlorophenol (DCP) was observed. On the other hand, pH exhibited an increasing from 7.0 to 8.3 during the experiment. Experiments using Milli-Q water at pH 7.0, iron, and H 2 O 2 concentrations of 0.3 and 10 mg L -1 , respectively, were carried out in order to study the effect of ions such as carbonate species, phosphate, and fluoride in typical concentrations often found in groundwater. Ion concentrations were combined by using a factorial experimental design 2 3 . Results showed that carbonates and fluoride did not produce a detrimental effect on the 2,4-D degradation, while phosphate inhibited the process. In this case, the pH increased also from 7.0 to 7.95 and 8.99. Effect of parameters such as pH, iron concentration, and hydrogen peroxide concentration on the 2,4-D degradation by the photo-Fenton process in groundwater was evaluated by using a factorial experimental design 2 3 . Results showed that the pH was the main parameter affecting the process. This study shows for the first time that using the photo-Fenton process at circumneutral pH and iron naturally present seems to be a promising process to remove pesticides from groundwater.

A modeling approach to account for toxicokinetic interactions in the calculation of biological hazard index for chemical mixtures.

PubMed

Haddad, S; Tardif, R; Viau, C; Krishnan, K

1999-09-05

Biological hazard index (BHI) is defined as biological level tolerable for exposure to mixture, and is calculated by an equation similar to the conventional hazard index. The BHI calculation, at the present time, is advocated for use in situations where toxicokinetic interactions do not occur among mixture constituents. The objective of this study was to develop an approach for calculating interactions-based BHI for chemical mixtures. The approach consisted of simulating the concentration of exposure indicator in the biological matrix of choice (e.g. venous blood) for each component of the mixture to which workers are exposed and then comparing these to the established BEI values, for calculating the BHI. The simulation of biomarker concentrations was performed using a physiologically-based toxicokinetic (PBTK) model which accounted for the mechanism of interactions among all mixture components (e.g. competitive inhibition). The usefulness of the present approach is illustrated by calculating BHI for varying ambient concentrations of a mixture of three chemicals (toluene (5-40 ppm), m-xylene (10-50 ppm), and ethylbenzene (10-50 ppm)). The results show that the interactions-based BHI can be greater or smaller than that calculated on the basis of additivity principle, particularly at high exposure concentrations. At lower exposure concentrations (e.g. 20 ppm each of toluene, m-xylene and ethylbenzene), the BHI values obtained using the conventional methodology are similar to the interactions-based methodology, confirming that the consequences of competitive inhibition are negligible at lower concentrations. The advantage of the PBTK model-based methodology developed in this study relates to the fact that, the concentrations of individual chemicals in mixtures that will not result in a significant increase in the BHI (i.e. > 1) can be determined by iterative simulation.

μPIXE for a μBrain: The vinegar fly's brain, antenna, sensilla hairs and eye ion concentrations

NASA Astrophysics Data System (ADS)

Reinert, Anja; Barapatre, Nirav; Sachse, Silke; Reinert, Tilo

2011-10-01

The vinegar fly Drosophila melanogaster is used as model organism to study a variety of different scientific purposes. Thus, our laboratory studies the olfactory system by neurobiological experiments. These techniques are often disruptive and need to compensate or exchange the body fluid, the lymph, with an artificial Ringer's solution in defined compartments of the fly. The solution mainly contains Na, Cl, K and Ca and is to keep physiological conditions. Therefore, the knowledge about the ion concentrations in the respective Drosophila lymph is required for a correct mixture of the ions. This paper presents the spatially resolved concentrations of P, S, Cl, K, Ca, Fe, Cu and Zn in lyophilised head cryosections of Drosophila by using quantitative μPIXE at the ion beam facility LIPSION in Leipzig. The PIXE maps enable a detailed analysis of particular regions of interest down to a spatial resolution of 0.5 μm. We quantified the ion concentrations especially in the brain, the antenna and its sensilla hairs acting as the olfactory organ of the fly, in the compound eye and in the mouthparts. The averaged element concentrations of these main compartments are (in descending order): P: 90 mM, K: 81 mM, S: 38 mM, Cl: 18 mM, Ca: 4.9 mM, Fe: 1.4 mM, Zn: 1.2 mM, Cu: 0.06 mM. Certain structures or cavities possess a remarkably high concentration of particular elements and might reflect the different functions of the compartments. An example presented in more detail is the composition of the compound eye. Conclusively, our findings on the ion concentrations might be useful for the mixture of the Drosophila Ringer's solution to ensure physiological conditions in experiments.

Occurrence of the angiotensin-converting enzyme inhibiting tripeptides Val-Pro-Pro and Ile-Pro-Pro in different cheese varieties of Swiss origin.

PubMed

Bütikofer, U; Meyer, J; Sieber, R; Walther, B; Wechsler, D

2008-01-01

The contents of the 2 antihypertensive peptides Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP) were determined in 101 samples from 10 different Swiss cheese varieties using HPLC with subsequent triple mass spectrometry. In the category of extra hard and hard cheeses, the Protected Denomination of Origin cheeses Berner Alpkäse and Berner Hobelkäse, L'Etivaz à rebibes, Le Gruyère, Sbrinz, Emmentaler (organic and conventional) and in the category of semihard cheeses, the varieties Tilsiter, Appenzeller 1/4 fat and full fat, Tête de Moine, and Vacherin fribourgeois were screened in the study. The average concentration of the sum of VPP and IPP in the screened cheese varieties varied to a large extent, and substantial variations were obtained for individual samples within the cheese varieties. The lowest average concentration of the 2 tri-petides was found in L'Etivaz à rebibes (n = 3) at 19.1 mg/kg, whereas Appenzeller 1/4 fat (n = 4) contained the greatest concentration at 182.2 mg/kg. In individual samples, the total concentration of VPP and IPP varied between 1.6 and 424.5 mg/kg. With the exception of a 10-yr-old cheese, VPP was always present at greater concentrations than IPP. Milk pretreatment, cultures, scalding conditions, and ripening time were identified as the key factors influencing the concentration of these 2 naturally occurring bioactive peptides in cheese. The results of the present study show that various traditional cheese varieties contain, on average, similar concentrations of the 2 antihypertensive peptides to the recently developed fermented milk products with blood pressure-lowering property. This may serve as a basis for the development of a functional cheese with blood pressure-lowering property.

The effects of low and moderate doses of caffeine supplementation on upper and lower body maximal voluntary concentric and eccentric muscle force.

PubMed

Tallis, Jason; Yavuz, Harley C M

2018-03-01

Despite the growing quantity of literature exploring the effect of caffeine on muscular strength, there is a dearth of data that directly explores differences in erogenicity between upper and lower body musculature and the dose-response effect. The present study sought to investigate the effects of low and moderate doses of caffeine on the maximal voluntary strength of the elbow flexors and knee extensors. Ten nonspecifically strength-trained, recreationally active participants (aged 21 ± 0.3 years) completed the study. Using a randomised, counterbalanced, and double-blind approach, isokinetic concentric and eccentric strength was measured at 60 and 180°/s following administration of a placebo, 3 mg·kg -1 body mass caffeine, and 6 mg·kg -1 body mass caffeine. There was no effect of caffeine on the maximal voluntary concentric and eccentric strength of the elbow flexors, or the eccentric strength of the knee extensors. Both 3 and 6 mg·kg -1 body mass caffeine caused a significant increase in peak concentric force of the knee extensors at 180°/s. No difference was apparent between the 2 concentrations. Only 6 mg·kg -1 body mass caused an increase in peak concentric force during repeated contractions. The results infer that the effective caffeine concentration to evoke improved muscle performance may be related to muscle mass and contraction type. The present work indicates that a relatively low dose of caffeine treatment may be effective for improving lower body muscular strength, but may have little benefit for the strength of major muscular groups of the upper body.

RWPV bioreactor mass transport: earth-based and in microgravity

NASA Technical Reports Server (NTRS)

Begley, Cynthia M.; Kleis, Stanley J.

2002-01-01

Mass transport and mixing of perfused scalar quantities in the NASA Rotating Wall Perfused Vessel bioreactor are studied using numerical models of the flow field and scalar concentration field. Operating conditions typical of both microgravity and ground-based cell cultures are studied to determine the expected vessel performance for both flight and ground-based control experiments. Results are presented for the transport of oxygen with cell densities and consumption rates typical of colon cancer cells cultured in the RWPV. The transport and mixing characteristics are first investigated with a step change in the perfusion inlet concentration by computing the time histories of the time to exceed 10% inlet concentration. The effects of a uniform cell utilization rate are then investigated with time histories of the outlet concentration, volume average concentration, and volume fraction starved. It is found that the operating conditions used in microgravity produce results that are quite different then those for ground-based conditions. Mixing times for microgravity conditions are significantly shorter than those for ground-based operation. Increasing the differential rotation rates (microgravity) increases the mixing and transport, while increasing the mean rotation rate (ground-based) suppresses both. Increasing perfusion rates enhances mass transport for both microgravity and ground-based cases, however, for the present range of operating conditions, above 5-10 cc/min there are diminishing returns as much of the inlet fluid is transported directly to the perfusion exit. The results show that exit concentration is not a good indicator of the concentration distributions in the vessel. In microgravity conditions, the NASA RWPV bioreactor with the viscous pump has been shown to provide an environment that is well mixed. Even when operated near the theoretical minimum perfusion rates, only a small fraction of the volume provides less than the required oxygen levels. 2002 Wiley Periodicals, Inc.

RWPV bioreactor mass transport: earth-based and in microgravity.

PubMed

Begley, Cynthia M; Kleis, Stanley J

2002-11-20

Mass transport and mixing of perfused scalar quantities in the NASA Rotating Wall Perfused Vessel bioreactor are studied using numerical models of the flow field and scalar concentration field. Operating conditions typical of both microgravity and ground-based cell cultures are studied to determine the expected vessel performance for both flight and ground-based control experiments. Results are presented for the transport of oxygen with cell densities and consumption rates typical of colon cancer cells cultured in the RWPV. The transport and mixing characteristics are first investigated with a step change in the perfusion inlet concentration by computing the time histories of the time to exceed 10% inlet concentration. The effects of a uniform cell utilization rate are then investigated with time histories of the outlet concentration, volume average concentration, and volume fraction starved. It is found that the operating conditions used in microgravity produce results that are quite different then those for ground-based conditions. Mixing times for microgravity conditions are significantly shorter than those for ground-based operation. Increasing the differential rotation rates (microgravity) increases the mixing and transport, while increasing the mean rotation rate (ground-based) suppresses both. Increasing perfusion rates enhances mass transport for both microgravity and ground-based cases, however, for the present range of operating conditions, above 5-10 cc/min there are diminishing returns as much of the inlet fluid is transported directly to the perfusion exit. The results show that exit concentration is not a good indicator of the concentration distributions in the vessel. In microgravity conditions, the NASA RWPV bioreactor with the viscous pump has been shown to provide an environment that is well mixed. Even when operated near the theoretical minimum perfusion rates, only a small fraction of the volume provides less than the required oxygen levels. 2002 Wiley Periodicals, Inc.

Environmental impacts of urban snow management--the alpine case study of Innsbruck.

PubMed

Engelhard, C; De Toffol, S; Lek, I; Rauch, W; Dallinger, R

2007-09-01

In regions with colder climate, snow at roads can accumulate significant amounts of pollutant chemicals. In northern countries various efforts have been made to face this problem, but for the alpine region little is known about the pollution of urban snow. The present case study was carried out in the city of Innsbruck (Austria). It aimed at measuring pollution of roadside snow and estimating the impact of snow management practises on environmental quality. Concentrations of copper, zinc, lead, cadmium, suspended solids and chloride were determined during a series of sampling events. Various locations with low and high traffic densities and in different distances from a highway have been investigated. The concentrations of copper were generally higher at sites with high traffic density compared to locations with low traffic impact. In contrast to this, the concentrations of zinc and lead remained almost unvaried irrespective of traffic density at the different sampling sites. For cadmium, the picture was more diverse, showing moderately elevated concentrations of this metal also at the urban reference site not polluted by traffic. This indicates that there may be also other important sources for cadmium besides traffic. Suspended solids accumulated in the roadside snow, the highest concentrations were found at the sites with high traffic density. The chloride concentrations were considerable in the snow, especially at the highway. Based on the results of the present measurement campaign, the environmental impact of snow disposal in rivers was also estimated. A negative impact on rivers from snow disposal seems likely to occur, although the discharged loads could only be calculated with substantial uncertainty, considering the high variability of the measured pollutant concentrations. For a more accurate evaluation of this management practise on rivers, further investigations would be necessary.

Homocysteine induces oxidative stress to damage trabecular meshwork cells.

PubMed

You, Zhi-Peng; Zhang, Yue-Zhi; Zhang, Yu-Lan; Shi, Lu; Shi, Ke

2018-05-01

The aim of the present study was to investigate the effect of homocysteine (Hcy) in on human trabecular meshwork cells (HTMCs). A total of 41 patients with primary open-angle glaucoma (POAG) and 53 patients with senile cataracts (control group) were recruited. Plasma and aqueous humor samples were collected and the Hcy concentrations were determined using enzymatic cycling assays. In cell experiments, normal HTMCs were passaged and randomly divided into a blank control group, a normal HTMC group and experimental groups, which were treated with different concentrations of Hcy. The HTMC activities were detected using the Cell Counting Kit-8 method and the HTMC mitochondrial membrane potential (MMP) was detected using JC-1 staining. Reactive oxygen species (ROS) released by trabecular meshwork cells was detected using flow cytometry and superoxide dismjutase-1 (SOD1) expression was detected using immunoblotting. The results revealed that the concentration of Hcy in the plasma and aqueous humor of the POAG group (14.44±0.86 and 1.60±0.27 µmol/l, respectively) was significantly higher compared with the control group (10.82±0.29 and 0.69±0.39 µmol/l). All tested concentrations (30, 100, 300 and 1,000 µmol/l) of Hcy reduced the MMP in HTMCs and inhibited HTMC proliferation in a dose-dependent manner. ROS production by HTMCs significantly increased with increased concentrations of Hcy, whereas SOD1 expression significantly decreased in a dose-dependent manner. In summary, patients with POAG were demonstrated to have increased concentrations of Hcy in the plasma and aqueous humor. High concentrations of Hcy in HTMCs induced an oxidative stress state, thereby further inhibiting HTMC proliferation. The results of the present study demonstrate that Hcy may be a potential treatment target in patients with POAG.

Photochemistry of PAHs in cosmic water ice. The effect of concentration on UV-VIS spectroscopy and ionization efficiency

NASA Astrophysics Data System (ADS)

Cuylle, Steven H.; Allamandola, Louis J.; Linnartz, Harold

2014-02-01

Context. Observations and models show that polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the interstellar medium. Like other molecules in dense clouds, PAHs accrete onto interstellar dust grains, where they are embedded in an ice matrix dominated by water. In the laboratory, mixed molecular ices (not containing PAHs) have been extensively studied using Fourier transform infrared absorption spectroscopy. Experiments including PAHs in ices have started, however, the concentrations used are typically much higher than the concentrations expected for interstellar ices. Optical spectroscopy offers a sensitive alternative. Aims: We report an experimental study of the effect PAH concentration has on the electronic spectra and the vacuum UV (VUV) driven processes of PAHs in water-rich ices. The goal is to apply the outcome to cosmic ices. Methods: Optical spectroscopic studies allow us to obtain in-situ and quasi real-time electronic solid state spectra of two prototypical PAHs (pyrene and coronene) embedded in water ice under VUV photoprocessing. The study is carried out on PAH:H2O concentrations in the range of 1:30 000 to pure PAH, covering the temperature range from 12 to 125 K. Results: PAH concentration strongly influences the efficiency of PAH cation formation. At low concentrations, ionization efficiencies are over 60% dropping to about 15% at 1:1000. Increasing the PAH concentration reveals spectral broadening in neutral and cation PAH spectra attributed to PAH clustering inside the ice. At the PAH concentrations expected for interstellar ices, some 10 to 20% may be present as cations. The presence of PAHs in neutral and ion form will add distinctive absorption bands to cosmic ice optical spectra and this may serve as a tool to determine PAH concentrations.

Calcium localization in lettuce leaves with and without tipburn: comparison of controlled-environment and field-grown plants

NASA Technical Reports Server (NTRS)

Barta, D. J.; Tibbitts, T. W.

1991-01-01

An electron microprobe was used to determine tissue concentrations of Ca across 20-mm-long leaves of 'Green Lakes' crisphead lettuce (Lactuca sativa L.) with and without tipburn injury. Concentrations within the fifth and 14th leaves, counted from the cotyledons, from plants grown under controlled-environment conditions were compared to concentrations within similar leaves obtained from plants grown under field conditions. Only the 14th leaf from plants grown under controlled-environment conditions developed tipburn. Injured areas on these leaves had Ca concentrations as low as 0.2 to 0.3 mg g-1 dry weight. Uninjured areas of tipburned leaves contained from 0.4 to 0.5 mg g-1 dry weight. Concentrations across the uninjured 14th leaf from field-grown plants averaged 1.0 mg g-1 dry weight. Amounts across the uninjured fifth leaves from both environments averaged 1.6 mg g-1 dry weight. In contrast, Mg concentrations were higher in injured leaves than in uninjured leaves and thus were negatively correlated with Ca concentrations. Magnesium concentrations averaged 4.7 mg g-1 dry weight in injured leaves compared with 3.4 mg g-1 dry weight in uninjured leaves from both environments. Magnesium concentrations were uniform across the leaf. Potassium concentrations were highest at the leaf apex and decreased toward the base and also decreased from the midrib to the margin. Potassium averaged 51 mg g-1 dry weight in injured and uninjured leaves from both environments. No significant differences in K concentration were present between injured and uninjured leaves. This study documented that deficient concentrations of Ca were present in areas of leaf tissue developing tipburn symptoms and that concentrations were significantly higher in similar areas of other leaves that had no symptoms. This study also documented that Ca concentrations were significantly lower in enclosed leaves that exhibited tipburn symptoms than in exposed leaves that did not exhibit tipburn. Also, the amounts of Ca in plants that developed tipburn in controlled environments were lower than in plants of the same cultivar that did not develop tipburn in field plantings. The reduced levels of Ca in plants grown in controlled environments were associated with faster development rates compared with field-grown plants.

Medium pH, carbon and nitrogen concentrations modulate the phosphate solubilization efficiency of Penicillium purpurogenum through organic acid production.

PubMed

Scervino, J M; Papinutti, V L; Godoy, M S; Rodriguez, M A; Della Monica, I; Recchi, M; Pettinari, M J; Godeas, A M

2011-05-01

To study phosphate solubilization in Penicillium purpurogenum as function of medium pH, and carbon and nitrogen concentrations. Tricalcium phosphate (CP) solubilization efficiency of P. purpurogenum was evaluated at acid or alkaline pH using different C and N sources. Glucose- and (NH(4) )(2) SO(4) -based media showed the highest P solubilization values followed by fructose. P. purpurogenum solubilizing ability was higher in cultures grown at pH 6·5 than cultures at pH 8·5. Organic acids were detected in both alkaline and neutral media, but the relative percentages of each organic acid differed. Highest P release coincided with the highest organic acids production peak, especially gluconic acid. When P. purpurogenum grew in alkaline media, the nature and concentration of organic acids changed at different N and C concentrations. A factorial categorical experimental design showed that the highest P-solubilizing activity, coinciding with the highest organic acid production, corresponded to the highest C concentration and lowest N concentration. The results described in the present study show that medium pH and carbon and nitrogen concentrations modulate the P solubilization efficiency of P. purpurogenum through the production of organic acids and particularly that of gluconic acid. In the P solubilization optimization studies, glucose and (NH(4) )(2) SO(4) as C and N sources allowed a higher solubilization efficiency at high pH. This organism is a potentially proficient soil inoculant, especially in P-poor alkaline soils where other P solubilizers fail to release soluble P. Further work is necessary to elucidate whether these results can be extrapolated to natural soil ecosystems, where different pH values are present. Penicillium purpurogenum could be used to develop a bioprocess for the manufacture of phosphatic fertilizer with phosphate calcium minerals. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

The effect of São Paulo's smoke-free legislation on carbon monoxide concentration in hospitality venues and their workers

PubMed Central

Abe, Tania M O; Pereira, Alexandre C; Megid, Maria Cristina; Shimabukuro, Cristina E; Valentin, Luis Sergio O; da C Ferreira, Marizete M; Nobre, Moacyr R C; Lancarotte, Ines; Barretto, Antonio Carlos Pereira

2010-01-01

Background Studies have shown that there is no safe level of secondhand smoke (SHS) exposure and there is a close link between SHS and the risk of coronary heart disease and stroke. Carbon monoxide (CO) is one of the most important components present in SHS. Objective To evaluate the impact of the smoking ban law in the city of Sao Paulo, Brazil, on the CO concentration in restaurants, bars, night clubs and similar venues and in their workers. Methods In the present study we measured CO concentration in 585 hospitality venues. CO concentration was measured in different environments (indoor, semi-open and open areas) from visited venues, as well as, in the exhaled air from approximately 627 workers of such venues. Measurements were performed twice, before and 12 weeks after the law implementation. In addition, the quality of the air in the city during the same period of our study was verified. Results The CO concentration pre-ban and pot-ban in hospitality venues was indoor area 4.57 (3.70) ppm vs 1.35 (1.66) ppm (p<0.0001); semi-open 3.79 (2.49) ppm vs 1.16 (1.14) ppm (p<0.0001); open area 3.31(2.2) ppm vs 1.31 (1.39) ppm (p<0.0001); smoking employees 15.78 (9.76) ppm vs 11.50 (7.53) ppm (p<0.0001) and non-smoking employees 6.88 (5.32) ppm vs 3.50 (2.21) ppm (p<0.0001). The average CO concentration measured in the city was lower than 1 ppm during both pre-ban and post-ban periods. Conclusion São Paulo's smoking-free legislation reduced significantly the CO concentration in hospitality venues and in their workers, whether they smoke or not. PMID:21109684

PM levels in urban area of Bejaia

NASA Astrophysics Data System (ADS)

Benaissa, Fatima; Maesano, Cara Nichole; Alkama, Rezak; Annesi-Maesano, Isabella

2017-04-01

Air pollution is not routinely measured in Bejaia City, Algeria, an urban area of around 200,000 inhabitants. We present first time measurements of particulate matter (PM) mass concentrations for this city (PM10, PM7, PM4, PM2.5 and PM1) over the course of one week, from July 8 to July 14, 2015. This study covered eight urban sampling sites and 169 measurements were obtained to determine mass concentration levels. Air pollution is not routinely measured in Bejaia City, Algeria, an urban area of around 200,000 inhabitants. We present first time measurements of particulate matter (PM) mass concentrations for this city (PM10, PM7, PM4, PM2.5 and PM1) over the course of one week, from July 8 to July 14, 2015. This study covered eight urban sampling sites and 169 measurements were obtained to determine mass concentration levels. The average city-wide PM10 and PM2.5 concentrations measured during this sampling were 87.8 ± 33.9 and 28.7 ± 10.6 µg/m3 respectively. These results show that particulate matter levels are high and exceed Algerian ambient air quality standards (maximum 80 µg/m3, without specifying the particle size). Further, PM10 and PM2.5 averages were well above the prescribed 24-hour average World Health Organization Air Quality Guidelines (WHO AQG) (50 µg/m3 for PM10 and 25 µg/m3 for PM2.5). The PM1, PM2,5, PM4 and PM7 fractions accounted for 15%, 32 %, 56% and 78% respectively of the PM10 measurements. Our analysis reveals that PM concentration variations in the study region were influenced primarily by traffic. In fact, lower PM10 concentrations (21.7 and 33.1 µg/m3) were recorded in residential sites while higher values (53.1, and 45.2 µg/m3) were registered in city centers. Keywords: Particulate matter, Urban area, vehicle fleet, Bejaia.

Simulated climate change conditions unveil the toxic potential of the fungicide pyrimethanil on the midge Chironomus riparius: a multigeneration experiment

PubMed Central

Müller, Ruth; Seeland, Anne; Jagodzinski, Lucas S; Diogo, Joao B; Nowak, Carsten; Oehlmann, Jörg

2012-01-01

Although it has been suggested that temperature increase may alter the toxic potential of environmental pollutants, few studies have investigated the potential risk of chemical stressors for wildlife under Global Climate Change (GCC) impact. We applied a bifactorial multigeneration study in order to test if GCC conditions alter the effects of low pesticide concentrations on life history and genetic diversity of the aquatic model organism Chironomus riparius. Experimental populations of the species were chronically exposed to a low concentration of the fungicide pyrimethanil (half of the no-observed-adverse-effect concentration: NOAEC/2) under two dynamic present-day temperature simulations (11.0–22.7°C; 14.0–25.2°C) and one future scenario (16.5–28.1°C). During the 140-day multigeneration study, survival, emergence, reproduction, population growth, and genetic diversity of C. riparius were analyzed. Our results reveal that high temperature and pyrimethanil act synergistically on the midge C. riparius. In simulated present-day scenarios, a NOAEC/2 of pyrimethanil as derived from a life-cycle toxicity test provoked only slight-to-moderate beneficial or adverse effects on C. riparius. In contrast, exposure to a NOAEC/2 concentration of pyrimethanil at a thermal situation likely for a summer under GCC conditions uncovered adverse effects on mortality and population growth rate. In addition, genetic diversity was considerably reduced by pyrimethanil in the future scenario, but only slightly under current climatic conditions. Our multigeneration study under near-natural (climatic) conditions indicates that not only the impact of climate change, but also low concentrations of pesticides may pose a reasonable risk for aquatic insects in future. PMID:22408736

Soot Formation in Laminar Premixed Ethylene/Air Flames at Atmospheric Pressure. Appendix G

NASA Technical Reports Server (NTRS)

Xu, F.; Sunderland, P. B.; Faeth, G. M.; Urban, D. L. (Technical Monitor)

2001-01-01

Soot formation was studied within laminar premixed ethylene/air flames (C/O ratios of 0.78-0.98) stabilized on a flat-flame burner operating at atmospheric pressure. Measurements included soot volume fractions by both laser extinction and gravimetric methods, temperatures by multiline emission, soot structure by thermophoretic sampling and transmission electron microscopy, major gas species concentrations by sampling and gas chromatography, concentrations of condensable hydrocarbons by gravimetric sampling. and velocities by laser velocimetry. These data were used to find soot surface growth rates and primary soot particle nucleation rates along the axes of the flames. Present measurements of soot surface growth rates were correlated successfully by predictions based on typical hydrogen-abstraction/carbon-addition (HACA) mechanisms of Frenklach and co-workers and Colket and Hall. These results suavest that reduced soot surface growth rates with increasing residence time seen in the present and other similar flames were mainly caused by reduced rates of surface activation due to reduced H atom concentrations as temperatures decrease as a result of radiative heat losses. Primary soot particle nucleation rates exhibited variations with temperature and acetylene concentrations that were similar to recent observations for diffusion flames; however, nucleation rates in the premixed flames were significantly lower than in, the diffusion flames for reasons that still must be explained. Finally, predictions of yields of major gas species based on mechanisms from both Frenklach and co-workers and Leung and Lindstedt were in good agreement with present measurements and suggest that H atom concentrations (relevant to HACA mechanisms) approximate estimates based on local thermodynamic equilibrium in the present flames.

Arsenic Speciation in Blue Mussels (Mytilus edulis) Along a Highly Contaminated Arsenic Gradient

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

Whaley-Martin, K.J.; Koch, I.; Moriarty, M.

2012-11-01

Arsenic is naturally present in marine ecosystems, and these can become contaminated from mining activities, which may be of toxicological concern to organisms that bioaccumulate the metalloid into their tissues. The toxic properties of arsenic are dependent on the chemical form in which it is found (e.g., toxic inorganic arsenicals vs nontoxic arsenobetaine), and two analytical techniques, high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and X-ray absorption spectroscopy (XAS), were used in the present study to examine the arsenic species distribution in blue mussels (Mytilus edulis) obtained from an area where there is a strongmore » arsenic concentration gradient as a consequence of mining impacted sediments. A strong positive correlation was observed between the concentration of inorganic arsenic species (arsenic compounds with no As-C bonds) and total arsenic concentrations present in M. edulis tissues (R{sup 2} = 0.983), which could result in significant toxicological consequences to the mussels and higher trophic consumers. However, concentrations of organoarsenicals, dominated by arsenobetaine, remained relatively constant regardless of the increasing As concentration in M. edulis tissue (R{sup 2} = 0.307). XANES bulk analysis and XAS two-dimensional mapping of wet M. edulis tissue revealed the presence of predominantly arsenic-sulfur compounds. The XAS mapping revealed that the As(III)-S and/or As(III) compounds were concentrated in the digestive gland. However, arsenobetaine was found in small and similar concentrations in the digestive gland as well as the surrounding tissue suggesting arsenobetaine may being used in all of the mussel's cells in a physiological function such as an intracellular osmolyte.« less

Application of compound parabolic concentrators to solar photovoltaic conversion. Final report

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

Cole, R.L.; Gorski, A.J.; Graven, R.M.

1977-02-01

The final results of an analytical and experimental study of the application of nonimaging concentrators to solar photovoltaic conversion are presented. Two versions of the Compound Parabolic Concentrator (CPC) were considered, the Dielectric Compound Parabolic Concentrator (DCPC) in which the concentrator is filled with a dielectric material that satisfies requirements for Total Internal Reflection (TIR), and a conventional CPC in which metallic reflection is used for the mirror surfaces. Two working prototype panels were constructed and tested during the course of the program. The first was a 1.22 m by 1.22 m DCPC panel that requires only ten adjustments/year, hasmore » a panel utilization factor (packing factor) of 96%, and delivered the equivalent of 138 W (peak) under 1 kW/m/sup 2/ direct insolation. The net energy conversion efficiency was 10.3% over the entire panel area. The second panel was a conventional CPC panel measuring 1.22 m by 1.22 m. This panel requires thirty-six adjustments per year, and delivers the equivalent of 97 W when under 1 kW/m/sup 2/ direct insolation. The results of a cost-effectiveness analysis of the concept of using nonimaging concentrators for photovoltaic conversion are also presented. The concentrator panels showed a decided savings in comparison to the cost of flat plate photovoltaic panels, both at present-day silicon costs ($2000/m/sup 2/) and projected lower silicon costs ($200/m/sup 2/). At a silicon cost of $200/m/sup 2/, a two-dimensional (cone) version of the collector has the potential for achieving from $0.60-2.00 per average watt (about $0.15-0.50 per peak watt) while requiring only crude (+-4.5/sup 0/) tracking.« less

Assessment of Heavy Metals in Municipal Sewage Sludge: A Case Study of Limpopo Province, South Africa

PubMed Central

Shamuyarira, Kudakwashe K.; Gumbo, Jabulani R.

2014-01-01

Heavy metals in high concentrations can cause health and environmental damage. Nanosilver is an emerging heavy metal which has a bright future of use in many applications. Here we report on the levels of silver and other heavy metals in municipal sewage sludge. Five towns in Limpopo province of South Africa were selected and the sludge from their wastewater treatment plants (WWTPs) was collected and analysed. The acid digested sewage sludge samples were analysed using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) methods. The concentrations of silver found were low, but significant, in the range 0.22 to 21.93 mg/kg dry mass. The highest concentration of silver was found in Louis Trichardt town with a concentration of 21.93 ± 0.38 mg/kg dry mass while the lowest was Thohoyandou with a concentration of 6.13 ± 0.12 mg/kg dry mass. A control sludge sample from a pit latrine had trace levels of silver at 0.22 ± 0.01 mg/kg dry mass. The result showed that silver was indeed present in the wastewater sewage sludge and at present there is no DWAF guideline standard. The average Cd concentration was 3.10 mg/kg dry mass for Polokwane municipality. Polokwane and Louis Trichardt municipalities exhibited high levels of Pb, in excess DWAF guidelines, in sludge at 102.83 and 171.87 mg/kg respectfully. In all the WWTPs the zinc and copper concentrations were in excess of DWAF guidelines. The presence of heavy metals in the sewage sludge in excess of DWAF guidelines presents environmental hazards should the sludge be applied as a soil ameliorant. PMID:24595211

Sediment quality in Burlington Harbor, Lake Champlain, U.S.A.

USGS Publications Warehouse

Lacey, E.M.; King, J.W.; Quinn, J.G.; Mecray, E.L.; Appleby, P.G.; Hunt, A.S.

2001-01-01

Surface samples and cores were collected in 1993 from the Burlington Harbor region of Lake Champlain. Sediment samples were analyzed for trace metals (cadmium, copper, lead, nickel, silver and zinc), simultaneously extracted metal/acid volatile sulfide (SEM-AVS), grain size, nutrients (carbon and nitrogen) and organic contaminants (polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)). The concentrations of cadmium, copper, silver and zinc from the partial sediment digestion of the surface samples correlated well with each other (r2 > 0.60) indicating that either a common process, or group of processes determined the sediment concentrations of these metals. In an analysis of the spatial distribution of the trace metals and PAHs, high surficial concentrations were present in the southern portion of the Harbor. The trace metal trend was strengthened when the concentrations were normalized by grain size. A sewage treatment plant outfall discharge was present in the southeastern portion of the Harbor at the time of this study and is the major source of trace metal and PAH contamination. Evaluation of sediment cores provides a proxy record of historical trace metal and organic inputs. The peak accumulation rate for copper, cadmium, lead, and zinc was in the late 1960s and the peak silver accumulation rate was later. The greatest accumulation of trace metals occurred in the late 1960s after discharges from the STP began. Subsequent declines in trace metal concentrations may be attributed to increased water and air regulations. The potential toxicity of trace metals and organic contaminants was predicted by comparing contaminant concentrations to benchmark concentrations and potential trace metal bioavailability was predicted with SEM-AVS results. Surface sample results indicate lead, silver, ???PAHs and ???PCBs are potentially toxic and/or bioavailable. These predictions were supported by studies of biota in the Burlington Harbor watershed. There is a clear trend of decreasing PAH and trace metal contaminant concentrations with distance from the STP outfall.Surface samples and cores were collected in 1993 from the Burlington Harbor region of Lake Champlain. Sediment samples were analyzed for trace metals (cadmium, copper, lead, nickel, silver and zinc), simultaneously extracted metal/acid volatile sulfide (SEM-AVS), grain size, nutrients (carbon and nitrogen) and organic contaminants (polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)). The concentrations of cadmium, copper, silver and zinc from the partial sediment digestion of the surface samples correlated well with each other (r2>0.60) indicating that either a common process, or group of processes determined the sediment concentrations of these metals. In an analysis of the spatial distribution of the trace metals and PAHs, high surficial concentrations were present in the southern portion of the Harbor. The trace metal trend was strengthened when the concentrations were normalized by grain size. A sewage treatment plant outfall discharge was present in the southeastern portion of the Harbor at the time of this study and is the major source of trace metal and PAH contamination. Evaluation of sediment cores provides a proxy record of historical trace metal and organic inputs. The peak accumulation rate for copper, cadmium, lead, and zinc was in the late 1960s and the peak silver accumulation rate was later. The greatest accumulation of trace metals occurred in the late 1960s after discharges from the STP began. Subsequent declines in trace metal concentrations may be attributed to increased water and air regulations. The potential toxicity of trace metals and organic contaminants was predicted by comparing contaminant concentrations to benchmark concentrations and potential trace metal bioavailability was predicted with SEM-AVS results. Surface sample results indicate lead, silver, ??PAHs and ??PCBs are potentially toxic and/or bi

Quantifying the impact of current and future concentrations of air pollutants on respiratory disease risk in England.

PubMed

Pannullo, Francesca; Lee, Duncan; Neal, Lucy; Dalvi, Mohit; Agnew, Paul; O'Connor, Fiona M; Mukhopadhyay, Sabyasachi; Sahu, Sujit; Sarran, Christophe

2017-03-27

Estimating the long-term health impact of air pollution in a spatio-temporal ecological study requires representative concentrations of air pollutants to be constructed for each geographical unit and time period. Averaging concentrations in space and time is commonly carried out, but little is known about how robust the estimated health effects are to different aggregation functions. A second under researched question is what impact air pollution is likely to have in the future. We conducted a study for England between 2007 and 2011, investigating the relationship between respiratory hospital admissions and different pollutants: nitrogen dioxide (NO 2 ); ozone (O 3 ); particulate matter, the latter including particles with an aerodynamic diameter less than 2.5 micrometers (PM 2.5 ), and less than 10 micrometers (PM 10 ); and sulphur dioxide (SO 2 ). Bayesian Poisson regression models accounting for localised spatio-temporal autocorrelation were used to estimate the relative risks (RRs) of pollution on disease risk, and for each pollutant four representative concentrations were constructed using combinations of spatial and temporal averages and maximums. The estimated RRs were then used to make projections of the numbers of likely respiratory hospital admissions in the 2050s attributable to air pollution, based on emission projections from a number of Representative Concentration Pathways (RCP). NO 2 exhibited the largest association with respiratory hospital admissions out of the pollutants considered, with estimated increased risks of between 0.9 and 1.6% for a one standard deviation increase in concentrations. In the future the projected numbers of respiratory hospital admissions attributable to NO 2 in the 2050s are lower than present day rates under 3 Representative Concentration Pathways (RCPs): 2.6, 6.0, and 8.5, which is due to projected reductions in future NO 2 emissions and concentrations. NO 2 concentrations exhibit consistent substantial present-day health effects regardless of how a representative concentration is constructed in space and time. Thus as concentrations are predicted to remain above limits set by European Union Legislation until the 2030s in parts of urban England, it will remain a substantial health risk for some time.

Iodine Systematics in the Ground Water of a Natural Setting

NASA Astrophysics Data System (ADS)

Renaud, R.; Clark, I. D.; Kotzer, T.; Bottomley, D.

2001-12-01

The transport and partitioning of 129I has been examined for a shallowly circulating ground water system at Sturgeon Falls in eastern Ontario. Vertical recharge occurs in a sandy aquifer with a seasonally inundated boreal forest. Concentrations of stable iodine, 129I, and tritium were measured on samples of ground water, precipitation, and soil litter. The present-day tritium profile delineates the position of the early 1960's thermonuclear bomb-pulse at a depth approximately 12 m. The concentrations of stable iodine for ground waters above, near and below the present-day bomb pulse were largely invariant, at approximately 0.5 ppb, whereas 129I concentrations decreased from 1.9 x 106 atoms/L at 9 m, to approximately 1.9 x 105 atoms/L on tritium-depleted waters occurring below the present-day location of the recharging thermonuclear bomb-test peak at 35 m. No substantial increases in the levels of 129I were evident in waters sampled near the present-day location of the thermonuclear bomb peak. Along a 30 cm soil profile, the concentrations of 129I ranged from approximately 4.3 x 108 atoms/g in the uppermost soil litter layer to 5.6 x 107 atoms/g in the siltier bottom soil horizons. Over that same profile, stable iodine varied from 4.7 ppm in the upper layers to 3.9 ppm in the lower layers. Rao and Fehn, 1999, measured iodine and 129I levels in surface waters and soils in western New York. They found 129I concentrations ranging from 3.5 x 108 atoms/g to 7.1 x 1010 atoms/g in the upper most layers of their soil cores, depending on the site's proximity to a former nuclear fuel reprocessing plant. Similarly, they noticed that the lower layers of their soil cores had 129I concentrations of at least an order of magnitude lower than the upper layers. It is proposed here that the levels of 129I in the deepest, tritium-depleted ground waters reflect the concentrations of 129I during the pre-thermonuclear testing period. However, the lower concentrations of 129I at Sturgeon Falls, compared with those from other studies in central Canada, suggest that the levels of 129I in these ground waters may have been attenuated by ion-exchange with organic materials in the near-surface soil horizons. Such processes have been documented during a previous study on the behavior of 129I in a shallow aquifer near a low-level, radioactive waste management area.

Seasonal and nonseasonal variability of satellite-derived surface pigment concentration in the California Current

NASA Technical Reports Server (NTRS)

Strub, P. Ted; James, Corinne; Thomas, Andrew C.; Abbott, Mark R.

1990-01-01

The large-scale patterns of satellite-derived surface pigment concentration off the west coast of North America are presented and are averaged into monthly mean surface wind fields over the California Current system (CCS) for the July 1979 to June 1986 period. The patterns are discussed in terms of both seasonal and nonseasonal variability for the indicated time period. The large-scale seasonal characteristics of the California Current are summarized. The data and methods used are described, and the problems known to affect the satellite-derived pigment concentrations and the wind data used in the study are discussed. The statistical analysis results are then presented and discussed in light of past observations and theory. Details of the CZCS data processing are described, and details of the principal estimator pattern methodology used here are given.

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

Spatial distribution of the daily precipitation concentration index in Southern Russia

NASA Astrophysics Data System (ADS)

Vyshkvarkova, Elena; Voskresenskaya, Elena; Martin-Vide, Javier

2018-05-01

The territory of Southern Russia presents a great diversity of climates and complex orography that lead to a very different precipitation distribution. Annual precipitation amounts differ between 222 mm in the coast of the Caspian Sea and > 2000 mm in the highest parts of the Caucasus Mountains. In order to investigate the statistical structure of daily precipitation across the study region the daily precipitation Concentration Index (CI) was used. In present paper, the CI was calculated for 42 meteorological stations during the 1970-2010 period. The analysis of precipitation concentration identified that the distribution of daily precipitation is more regular over the west, north and south regions compared to the east (the Caspian Sea coast and the Caspian Depression). The Crimean peninsula is characterized by low CI values in the north and high values in the eastern part.

Mixing of acrylic bone cement: effect of oxygen on setting properties.

PubMed

He, Shulin; Scott, Christopher; Higham, Paul

2003-12-01

The present study investigates the effect of different mixing methods on the setting properties of bone cement. It was found that vacuum mixing decreased the setting time of the bone cement by nearly 2 min (10%), compared to mixing in air. Two additional experiments, in which the bone cement powders were purged with argon or oxygen, and mixed with the methyl methacrylate monomer, revealed that oxygen concentrations in the bone cement had a great effect on the setting time. The setting time increases significantly as the oxygen concentration increases, which suggests that the decrease in the setting time by vacuum mixing may be attributed to the lower oxygen levels present in the mixer. No significant effect was observed on dough time or maximum exothermic temperature by varying oxygen concentrations in the bone cement mixer.

Toward refined estimates of ambient PM2.5 exposure: Evaluation of a physical outdoor-to-indoor transport model

NASA Astrophysics Data System (ADS)

Hodas, Natasha; Meng, Qingyu; Lunden, Melissa M.; Turpin, Barbara J.

2014-02-01

Because people spend the majority of their time indoors, the variable efficiency with which ambient PM2.5 penetrates and persists indoors is a source of error in epidemiologic studies that use PM2.5 concentrations measured at central-site monitors as surrogates for ambient PM2.5 exposure. To reduce this error, practical methods to model indoor concentrations of ambient PM2.5 are needed. Toward this goal, we evaluated and refined an outdoor-to-indoor transport model using measured indoor and outdoor PM2.5 species concentrations and air exchange rates from the Relationships of Indoor, Outdoor, and Personal Air Study. Herein, we present model evaluation results, discuss what data are most critical to prediction of residential exposures at the individual-subject and populations levels, and make recommendations for the application of the model in epidemiologic studies. This paper demonstrates that not accounting for certain human activities (air conditioning and heating use, opening windows) leads to bias in predicted residential PM2.5 exposures at the individual-subject level, but not the population level. The analyses presented also provide quantitative evidence that shifts in the gas-particle partitioning of ambient organics with outdoor-to-indoor transport contribute significantly to variability in indoor ambient organic carbon concentrations and suggest that methods to account for these shifts will further improve the accuracy of outdoor-to-indoor transport models.

An integrated, quality by design (QbD) approach for design, development and optimization of orally disintegrating tablet formulation of carbamazepine.

PubMed

Mishra, Saurabh M; Rohera, Bhagwan D

2017-11-01

The objective of the present study was to design and develop a formulation for orally disintegrating tablets (ODTs) of carbamazepine using quality by design principles. The target product profile (TPP) and quality target product profile (QTPP) of ODTs were identified. Risk assessment was carried out by leveraging prior knowledge and experience to define the criticality of factors based on their impact by Ishikawa fishbone diagram and preliminary hazard analysis tool. Box-Behnken response surface methodology was used to study the effect of critical factors on various attributes of ODTs. The independent factors selected were compression pressure (X 1 ), concentration of sublimating agent (volatile material) (X 2 ), disintegrant concentration (X 3 ) and the responses were tablet crushing strength, tablet porosity, disintegration time, water absorption time, tablet friability and drug dissolution. ANOVA and lack of fit test illustrated that selected independent variables had significant effect on the response variables, and excellent correlation was observed between actual and predicted values. Optimization by desirability function indicated that compression pressure, X 1 (1534 lbs), ammonium bicarbonate concentration, X 2 (7.68%) and Kollidon ® CL-SF concentration, X 3 (6%) were optimum to prepare ODT formulation of carbamazepine of desired attributes complying with QTPP. Thus, in the present study, a high level of assurance was established for ODT product quality and performance.

Impact of seasonal variation, age and smoking status on human semen parameters: The Massachusetts General Hospital experience

PubMed Central

Chen, Zuying; Godfrey-Bailey, Linda; Schiff, Isaac; Hauser, Russ

2004-01-01

Background To investigate the relationship of human semen parameters with season, age and smoking status. Methods The present study used data from subjects recruited into an ongoing cross-sectional study on the relationship between environmental agents and semen characteristics. Our population consisted of 306 patients who presented to the Vincent Memorial Andrology Laboratory of Massachusetts General Hospital for semen evaluation. Sperm concentration and motility were measured with computer aided sperm analysis (CASA). Sperm morphology was scored using Tygerberg Kruger strict criteria. Regression analyses were used to investigate the relationships between semen parameters and season, age and smoking status, adjusting for abstinence interval. Results Sperm concentration in the spring was significantly higher than in winter, fall and summer (p < 0.05). There was suggestive evidence of higher sperm motility and percent of sperm with normal morphology in the spring than in the other seasons. There were no statistically significant relationships between semen parameters and smoking status, though current smokers tended to have lower sperm concentration. We also did not find a statistically significant relationship between age and semen parameters. Conclusions We found seasonal variations in sperm concentration and suggestive evidence of seasonal variation in sperm motility and percent sperm with normal morphology. Although smoking status was not a significant predictor of semen parameters, this may have been due to the small number of current smokers in the study. PMID:15507127

Does balneotherapy with low radon concentration in water influence the endocrine system? A controlled non-randomized pilot study.

PubMed

Nagy, Katalin; Berhés, István; Kovács, Tibor; Kávási, Norbert; Somlai, János; Bender, Tamás

2009-08-01

Radon bath is a well-established modality of balneotherapy for the management of degenerative musculoskeletal disorders. The present study was conducted to ascertain whether baths of relatively low (80 Bq/l) radon concentration have any influence on the functioning of the endocrine system. In the study, a non-randomized pilot study, 27 patients with degenerative musculoskeletal disorders received 30-min radon baths (of 31-32 degrees C temperature and 80 Bq/l average radon concentration) daily, for 15 days. Twenty-five patients with matching pathologies were subjected to balneotherapy according to the same protocol, using thermal water with negligible radon content (6 Bq/l). Serum thyroid stimulating hormone, prolactin, cortisol, adrenocorticotropic hormone, and dehydroepiandrosterone levels were measured before and after a balneotherapy course of 15 sessions. Comparison of the accumulated data using the Wilcoxon test did not reveal any significant difference between pre- and post-treatment values or between the two patient groups. It is noted that while the beneficial effects of balneotherapy with radon-containing water on degenerative disorders is widely known, only few data have been published in the literature on its effect on endocrine functions. The present study failed to demonstrate any substantial effect of thermal water with relatively low radon content on the functioning of the endocrine system.

Defining appropriate methods for studying toxicities of trace metals in nutrient solutions.

PubMed

Li, Zhigen; Wang, Peng; Menzies, Neal W; Kopittke, Peter M

2018-01-01

The use of inappropriate experimental conditions for examining trace metal phytotoxicity results in data of questionable value. The present study aimed to identify suitable parameters for study of phytotoxic metals in nutrient solutions. First, the literature was reviewed to determine the concentration of six metals (Cd, Cu, Hg, Ni, Pb, and Zn) from solution of contaminated soils. Next, the effects of pH, P, Cl, NO 3 , and four Fe-chelators were investigated by using thermodynamic modelling and by examining changes in root elongation rate of soybean (Glycine max cv. Bunya). The literature review identified that the solution concentrations of metals in soils were low, ranging from (µM) 0.069-11Cd, 0.19-15.8 Cu, 0.000027-0.000079 Hg, 1.0-8.7 Ni, 0.004-0.55 Pb, and 0.4-36.3 Zn. For studies in nutrient solution, pH should generally be low given its effects on solubility and speciation, as should the P concentration due to the formation of insoluble phosphate salts. The concentrations of Cl, NO 3 , and various chelators also influence metal toxicity through alteration of metal speciation. The nutrient solutions used to study metal toxicity should consider environmentally-relevant conditions especially for metal concentrations, with concentrations of other components added at levels that do not substantially alter metal toxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

Element concentrations on Hypogymnia physodes after three years of transplanting along Lake Michigan

USGS Publications Warehouse

Bennett, J.P.; Dibben, M.J.; Lyman, K.J.

1996-01-01

Improvements in air quality in air polluted areas are often followed by recolonization of habitats by sensitive lichens that had died out when air quality was worse. To test the hypothesis that air quality at Indiana Dunes National Lakeshore has improved such that lichens could recolonize the area, samples of a species that once grew in the park, Hypogymnia physodes, were transplanted from Door County, Wisconsin to the park and three other sites along the western shore of Lake Michigan, including one at the site of origin as a control. The lichens were sampled for 3 years and tissue concentrations of 20 chemical elements were measured. There were no significant differences between concentrations over the 3 year study duration at the control site in Door County, suggesting that transplanting itself had no impacts on tissue concentrations. All but two elements increased in concentration from north to south with the greatest increases occurring in the third year of the study. Lichens at Indiana Dunes at the end of the study had suffered severe mortality. Chromium increased the most from north to south but concentrations were not higher than maxima observed in other studies. Arsenic and sulfur, however, exceeded known toxic thresholds or maxima observed in other studies on this species. Four hypotheses are presented to explain the toxicity of elements to this species.

Evaluation of Solidification/Stabilization for Treating Contaminates Soils from the Frontier Hard Chrome Site

DTIC Science & Technology

1992-05-01

replicates were ɘ.020 mg/L. The chromium present was in the trivalent form. 139. Vendor 2. The replicate total chromium TCLP concentrations in the...criterion. The chromium present in the leachates was in the trivalent form, shown by concentrations of Cr(VI) of ɘ.020, ɘ.020, and 0.042 mg/L. 142...concentrations of total chromium were 4.7, 3.7, and 4.1 mg/L. Chromium is present in the trivalent form. The total chromium concentrations were below

Carrier tests to assess the effective sporicidal concentration of a liquid chemical disinfectant for a sanitization program.

PubMed

Ceccanti, Stefano; Giampieri, Simona; Burgalassi, Susi

2011-01-01

The aim of the present investigation was to evaluate the microbial efficacy against highly resistant bacterial spores on different substrates using the lowest effective concentration of a market liquid sporicide based on peracetic acid. The validation was carried out following modified European regulatory agencies procedures or test methods and USP guidelines, employing carriers of materials usually treated with the sporicidal solution and present in grade A cleanrooms and spores of four different microorganisms: Bacillus subtilis and Clostridium sporogenes, both from the ATCC collection, and Bacillus cereus and Bacillus sphaericus as environmental isolates. A statistical evaluation of data was made to estimate the variance for different study conditions. The experiments highlighted that 70% suitable dilution of the ready-to-use peracetic acid solution was effective in both clean and dirty conditions, showing at least 2 log spore reduction after treatment. To obtain effective sporicidal action on the surfaces in cleanrooms it is sufficient to use a sporicidal solution with a ready-to-use concentration of 70% while ensuring a contact time of 10 min. In any case, the reduction of sporicide concentration ensures a high degree of disinfection and provides a consumption savings. Wide-spectrum disinfectants are used in the pharmaceutical industry for the decontamination of work surfaces and equipment, but these products have some degree of toxicity for operators. This work arises from the needs of pharmaceutical companies to find the lowest effective concentration of sanitizers in order to reduce toxicity to personnel. The sanitizer used in the study was a market liquid sporicide based on peracetic acid. When we started our work no similar studies were reported in the literature, so we took European regulatory agencies and USP guidelines as a starting point, employing carriers of hard, non-porous materials usually treated with the sporicidal solution and present in sterile rooms and spores of four different microorganisms. The experiments highlighted that it is sufficient to use a 70% sporicidal solution concentration with a contact time of 10 min to reduce the number of spores to acceptable values for medicinal production. The reduction of sporicide concentration both ensures a high degree of disinfection and provides a safer working environment and consumption savings.

An evaluation of the CYP2D6 and CYP3A4 inhibition potential of metoprolol metabolites and their contribution to drug-drug and drug-herb interaction by LC-ESI/MS/MS.

PubMed

Borkar, Roshan M; Bhandi, Murali Mohan; Dubey, Ajay P; Ganga Reddy, V; Komirishetty, Prashanth; Nandekar, Prajwal P; Sangamwar, Abhay T; Kamal, Ahmed; Banerjee, Sanjay K; Srinivas, R

2016-10-01

The aim of the present study was to evaluate the contribution of metabolites to drug-drug interaction and drug-herb interaction using the inhibition of CYP2D6 and CYP3A4 by metoprolol (MET) and its metabolites. The peak concentrations of unbound plasma concentration of MET, α-hydroxy metoprolol (HM), O-desmethyl metoprolol (ODM) and N-desisopropyl metoprolol (DIM) were 90.37 ± 2.69, 33.32 ± 1.92, 16.93 ± 1.70 and 7.96 ± 0.94 ng/mL, respectively. The metabolites identified, HM and ODM, had a ratio of metabolic area under the concentration-time curve (AUC) to parent AUC of ≥0.25 when either total or unbound concentration of metabolite was considered. In vitro CYP2D6 and CYP3A4 inhibition by MET, HM and ODM study revealed that MET, HM and ODM were not inhibitors of CYP3A4-catalyzed midazolam metabolism and CYP2D6-catalyzed dextromethorphan metabolism. However, DIM only met the criteria of >10% of the total drug related material and <25% of the parent using unbound concentrations. If CYP inhibition testing is solely based on metabolite exposure, DIM metabolite would probably not be considered. However, the present study has demonstrated that DIM contributes significantly to in vitro drug-drug interaction. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Salivary cytokines and the association between obstructive sleep apnea syndrome and periodontal disease.

PubMed

Nizam, Nejat; Basoglu, Ozen K; Tasbakan, Mehmet S; Nalbantsoy, Ayşe; Buduneli, Nurcan

2014-07-01

A higher prevalence of periodontal disease has been reported in patients with obstructive sleep apnea syndrome (OSAS), and these two chronic conditions may be linked via inflammatory pathways. The aim of the present study is to evaluate the salivary interleukin (IL)-1β, IL-6, IL-21, IL-33, and pentraxin-3 (PTX3) concentrations in patients with and without OSAS. A total of 52 patients were included in the study. Thirteen individuals were in the control (non-OSAS) group, 17 were in the mild/moderate OSAS group, and 22 were in the severe OSAS group. Clinical periodontal measurements were recorded, and saliva samples were obtained before initiation of periodontal intervention. Enzyme-linked immunosorbent assay was used to determine salivary cytokine concentrations. Data were statistically analyzed using D'Agostino-Pearson omnibus normality, Spearman ρ rank, Kruskal-Wallis, and Dunn tests. Salivary IL-6 and IL-33 concentrations were similar in the two OSAS groups (P >0.05), which were statistically higher than the control group (P <0.05). IL-1β, IL-21, and PTX3 concentrations were similar in the study groups. The only significant correlation between clinical periodontal parameters and salivary cytokines was found between clinical attachment level (CAL) and IL-21 (P = 0.02). Highly significant correlations were found between probing depth, CAL measures, and indicators of OSAS severity (P <0.01). The present findings suggest that OSAS may have an increasing effect on salivary IL-6 and IL-33 concentrations regardless of OSAS severity. Additional investigation is required to elucidate a potential bidirectional relationship between OSAS and periodontal disease.

Effects of gemfibrozil on lipid metabolism, steroidogenesis, and reproduction in the fathead minnow (Pimephales promelas).

PubMed

Skolness, Sarah Y; Durhan, Elizabeth J; Jensen, Kathleen M; Kahl, Michael D; Makynen, Elizabeth A; Villeneuve, Daniel L; Ankley, Gerald T

2012-11-01

Fibrates are a class of pharmaceuticals that indirectly modulate cholesterol biosynthesis through effects on peroxisome proliferator-activated receptors. Gemfibrozil is a fibrate that has been detected in wastewater treatment plant influents, effluents, and drinking water. The objective of the present study was to assess the potential physiological and reproductive impacts of gemfibrozil on fathead minnows (Pimephales promelas). Fish were exposed to gemfibrozil in two different studies. The first was a short-term test with water concentrations of 0, 15, and 600 µg gemfibrozil/L, sampling after 2 or 8 d of exposure. Plasma cholesterol concentrations were significantly reduced in males exposed to 600 µg gemfibrozil/L for 8 d. In addition, expression of several hepatic genes important to lipid metabolism was altered, suggesting that gemfibrozil does affect lipid metabolism in fish. A 21-d study was conducted to investigate further the effects on lipid metabolism and steroidogenesis as well as to assess potential impacts of gemfibrozil on reproduction. Fish were exposed to water concentrations of 0, 1.5, 15, 600, and 1,500 µg gemfibrozil/L. Exposure to 1,500 µg gemfibrozil/L caused a modest, but not significant, reduction in fecundity. However, gemfibrozil had no consistent effect on plasma cholesterol, triglycerides, or sex steroids after 21 d of exposure. The present study showed no evidence for significant physiological or reproductive impacts of gemfibrozil at an environmentally relevant concentration of 1.5 µg/L. Copyright © 2012 SETAC.

A mathematical model for lactate transport to red blood cells.

PubMed

Wahl, Patrick; Yue, Zengyuan; Zinner, Christoph; Bloch, Wilhelm; Mester, Joachim

2011-03-01

A simple mathematical model for the transport of lactate from plasma to red blood cells (RBCs) during and after exercise is proposed based on our experimental studies for the lactate concentrations in RBCs and in plasma. In addition to the influx associated with the plasma-to-RBC lactate concentration gradient, it is argued that an efflux must exist. The efflux rate is assumed to be proportional to the lactate concentration in RBCs. This simple model is justified by the comparison between the model-predicted results and observations: For all 33 cases (11 subjects and 3 different warm-up conditions), the model-predicted time courses of lactate concentrations in RBC are generally in good agreement with observations, and the model-predicted ratios between lactate concentrations in RBCs and in plasma at the peak of lactate concentration in RBCs are very close to the observed values. Two constants, the influx rate coefficient C (1) and the efflux rate coefficient C (2), are involved in the present model. They are determined by the best fit to observations. Although the exact electro-chemical mechanism for the efflux remains to be figured out in the future research, the good agreement of the present model with observations suggests that the efflux must get stronger as the lactate concentration in RBCs increases. The physiological meanings of C (1) and C (2) as well as their potential applications are discussed.

Grape juice concentrate prevents oxidative DNA damage in peripheral blood cells of rats subjected to a high-cholesterol diet.

PubMed

Aguiar, Odair; Gollücke, Andréa Pittelli Boiago; de Moraes, Bárbara Bueno; Pasquini, Gabriela; Catharino, Rodrigo Ramos; Riccio, Maria Francesca; Ihara, Silvia Saiuli Miki; Ribeiro, Daniel Araki

2011-03-01

The goal of the present study was to investigate whether subchronic treatment with grape juice concentrate is able to protect liver and peripheral blood cells against cholesterol-induced injury in rats. The effects of the grape juice concentrate treatment on histopathological changes, immunohistochemistry for cyclo-oxygenase-2 (COX-2), and basal and oxidative DNA damage induced by H2O2 using a single-cell gel (comet) assay were evaluated. Male Wistar rats (n 18) were divided into three groups: group 1--negative control; group 2--cholesterol at 1 % (w/w) in their diet, treated for 5 weeks; group 3--cholesterol at 1 % in their chow, treated for 5 weeks, and grape juice concentrate at 222 mg/d in their drinking-water in the final week only. The results indicated that the treatment with grape juice concentrate did not show remarkable differences regarding liver tissue in group 3 compared with group 2. However, grape juice concentrate was able to decrease oxidative DNA damage induced by H2O2 in peripheral blood cells, as depicted by the tail moment results. COX-2 expression in the liver did not show statistically significant differences (P>0·05) between groups. Taken together, the present results suggest that the administration of subchronic grape juice concentrate prevents oxidative DNA damage in peripheral blood cells.

NHEXAS PHASE I MARYLAND STUDY--LIPIDS IN BLOOD ANALYTICAL RESULTS

EPA Science Inventory

The Lipids in Blood data set presents concentrations of cholesterol and total triglycerides in blood serum. The data set presents measurements for up to 2 lipids in 358 blood samples over 79 households. Each sample was collected via a venous sample from the primary respondent w...

Effect of surfactant concentration on the evaporation of droplets on cotton (Gossypium hirsutum L.) leaves.

PubMed

Zhou, Zhaolu; Cao, Chong; Cao, Lidong; Zheng, Li; Xu, Jun; Li, Fengmin; Huang, Qiliang

2018-04-05

The evaporation kinetics of pesticide droplets deposited on a leaf surface can affect their application efficiency. Evaporation of droplets on the hydrophobic leaves has received considerable attention, but little is known about hydrophilic leaf surfaces. In this study, the effect of surfactant concentration on the evaporation of droplets deposited on cotton leaves was investigated. The evaporation time is roughly decreased for concentrations ranging from 0% to 0.01% and increased from 0.01% to 0.10%. Contrary to the widely held belief that pesticide retention on target crops can rapidly be formed only with surfactant concentrations exceeding the CMC (critical micelle concentration), this study demonstrates that, on hydrophilic cotton leaves, fast evaporation of the droplet at surfactant concentrations of 0.01% (CMC) can reduce the volume quickly, lower the loss point and enhance pesticide retention. In addition, the evolution of droplet volume, height and contact angle on the cotton leaf surface were measured to confirm this conclusion. The result presented herein can be used to guide the use of surfactants and pesticides in agriculture. Copyright © 2018 Elsevier B.V. All rights reserved.

[Study on the effect of solar spectra on the retrieval of atmospheric CO2 concentration using high resolution absorption spectra].

PubMed

Hu, Zhen-Hua; Huang, Teng; Wang, Ying-Ping; Ding, Lei; Zheng, Hai-Yang; Fang, Li

2011-06-01

Taking solar source as radiation in the near-infrared high-resolution absorption spectrum is widely used in remote sensing of atmospheric parameters. The present paper will take retrieval of the concentration of CO2 for example, and study the effect of solar spectra resolution. Retrieving concentrations of CO2 by using high resolution absorption spectra, a method which uses the program provided by AER to calculate the solar spectra at the top of atmosphere as radiation and combine with the HRATS (high resolution atmospheric transmission simulation) to simulate retrieving concentration of CO2. Numerical simulation shows that the accuracy of solar spectrum is important to retrieval, especially in the hyper-resolution spectral retrieavl, and the error of retrieval concentration has poor linear relation with the resolution of observation, but there is a tendency that the decrease in the resolution requires low resolution of solar spectrum. In order to retrieve the concentration of CO2 of atmosphere, the authors' should take full advantage of high-resolution solar spectrum at the top of atmosphere.

Soil decontamination of 2,4,6- trinitrotoluene by alfalfa (Medicago sativa).

PubMed

Fallahi, S; Habibi-Rezaei, M; Khayami, M; Heydari, R

2007-12-15

Present study investigate the toxicity effect of 2,4,6-trinitrotoluene (TNT) on a terrestrial plant, alfalfa (Medicago sativa) in artificial soils. In this study, TNT toxicity assessment was performed on spiked silica with this nitroaromatic compound by determination of the percent of emergence and shoots and roots biomasses at the concentration range of 3.2-10000 mg kg(-1) Dry Weight (DW). The emergence was reduced by 22-32% after 5 days of exposure at TNT concentrations up to 100 mg kg(-1) DW; shoot and root biomasses were reduced by 48-50 and 63-74%, respectively after 30 days exposure at TNT concentrations < or = 32 mg kg(-1) DW. Concentrations higher than 100 mg kg(-1) DW can not be tolerated at all. Concentrations of TNT and its metabolites in silica, root and shoot were measured by High-Performance Liquid Chromatography (HPLC). Analyses of TNT spiked soil extracts reveal hat during alfalfa cultivation for 30 days, TNT was partially transformed at the extent of 15-27%. This transformation decreased at higher TNT soil concentrations. TNT is taken up and metabolized by plants to its downstream derivatives.

Assessment of Trace Element Concentrations in Birds of Prey in Korea.

PubMed

Kim, Jungsoo; Oh, Jong-Min

2016-07-01

This study presents liver concentrations of trace elements of cinereous vultures (Aegypius monachus), common buzzards (Buteo buteo), common kestrels (Falco tinnunculus), and Eurasian eagle owls (Bubo bubo) collected in Korea from 2007 to 2008. Iron (Fe), manganese (Mn), copper (Cu), lead (Pb), and cadmium (Cd) concentrations in common kestrel juveniles were greater than in other juveniles of birds of prey. Adult cinereous vultures had greater Fe, Pb, and Cd concentrations than in those of other species, but common kestrels had greater Mn and Cu concentrations than in those of other birds of prey. Zinc concentrations in Eurasian eagle owl juveniles and adults were greater than in juveniles and adults of other species, respectively. In common kestrels, Fe, Cu, Pb, and Cd concentrations were significantly greater in adults than in juveniles. In Eurasian eagle owls, only Pb concentrations were greater in adults than in juveniles. Essential elements, such as Fe, Zn, Mn, and Cu concentrations, were within the range of other birds of prey studies. Seventeen individual birds of prey (30 %) were at a level considered Pb exposed (6-30 µg/g dw). This is a greater proportion than reported earlier in herons, egrets, and other birds from Korea. Elevated Pb concentration might be attributed to ingestion of Pb shot and bullet fragments for cinereous vultures and common buzzards, and urbanization for common kestrels. Cadmium concentrations in birds of prey were within the background concentrations (<3 µg/g dw) for wild birds.

Contributory Role of Virtual Courses via Skype to Control Embarrassment of Iranian EFL Learners' Performance

ERIC Educational Resources Information Center

Jahanbakhsh, Elham; Chalak, Azizeh

2018-01-01

In recent years, there has been an increasing interest in integration of technology for pedagogical purposes. The present study aimed at finding out how presentation in the frame of virtual courses can control embarrassment and shyness of Iranian EFL learners. The practical part concentrated on using Skype for the purpose of presentation in…

Branched-chain amino acids complex inhibits melanogenesis in B16F0 melanoma cells.

PubMed

Cha, Jae-Young; Yang, Hyun-Ju; Moon, Hyung-In; Cho, Young-Su

2012-04-01

Present study was investigated the effect of each or complex of three branched-chain amino acids (BCAAs; isoleucine, leucine, and valine) on melanin production in B16F0 melanoma cells treated with various concentrations (1-16 mM) for 72 h. Among the 20 amino acids, lysine and glycine showed the highest activities of DPPH radical scavenging and mushroom tyrosinase inhibition, respectively. Each and combination of BCAAs reduced melanogenesis in a concentration-dependent manner without any morphological changes and cell viability in melanoma cells. Present study was also investigated the inhibitory effects of each or complex of BCAAs at each 10 mM concentration on the 100 μM IBMX-mediated stimulation of melanogenesis in melanoma cells for 72 h and found that IBMX treatment was stimulated to enhance melanin synthesis and that the complex of BCAAs was the most effectively inhibited in the melanin amounts of cellular and extracellular and the whitening the cell pellet. When the inhibitory effect of BCAAs on tyrosinase was examined by intracellular tyrosinase assay, both isoleucine and valine exhibit slightly inhibition, but leucine and combination of BCAAs did not inhibit the cell-derived tyrosinase activity. Present study demonstrated that complex of BCAAs inhibited melanin production without changes intercellular tyrosinase activity. Thus, the complex of BCAAs may be used in development of safe potentially depigmenting agents.

Post-mortem clinical pharmacology

PubMed Central

Ferner, R E

2008-01-01

Clinical pharmacology assumes that deductions can be made about the concentrations of drugs from a knowledge of the pharmacokinetic parameters in an individual; and that the effects are related to the measured concentration. Post-mortem changes render the assumptions of clinical pharmacology largely invalid, and make the interpretation of concentrations measured in post-mortem samples difficult or impossible. Qualitative tests can show the presence of substances that were not present in life, and can fail to detect substances that led to death. Quantitative analysis is subject to error in itself, and because post-mortem concentrations vary in largely unpredictable ways with the site and time of sampling, as a result of the phenomenon of post-mortem redistribution. Consequently, compilations of ‘lethal concentrations’ are misleading. There is a lack of adequate studies of the true relationship between fatal events and the concentrations that can be measured subsequently, but without such studies, clinical pharmacologists and others should be wary of interpreting post-mortem measurements. PMID:18637886

Irreversible sorption of trace concentrations of perfluorocarboxylic acids to fiber filters used for air sampling

NASA Astrophysics Data System (ADS)

Arp, Hans Peter H.; Goss, Kai-Uwe

Due to the apparent environmental omnipresence of perfluorocarboxylic acids (PFAs), an increasing number of researchers are investigating their ambient particle- and gas-phase concentrations. Typically this is done using a high-volume air sampler equipped with Quartz Fiber Filters (QFFs) or Glass Fiber Filters (GFFs) to sample the particle-bound PFAs and downstream sorbents to sample the gas-phase PFAs. This study reports that at trace, ambient concentrations gas-phase PFAs sorb to QFFs and GFFs irreversibly and hardly pass through these filters to the downstream sorbents. As a consequence, it is not possible to distinguish between particle- and gas-phase concentrations, or to distinguish concentrations on different particle size fractions, unless precautions are taken. Failure to take such precautions could have already caused reported data to be misinterpreted. Here it is also reported that deactivating QFFs and GFFs with a silylating agent renders them suitable for sampling PFAs. Based on the presented study, a series of recommendations for air-sampling PFAs are provided.

Lead-210 from nuclear explosions in the environment

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

Jaworowski, Z.; Kownacka, L.; Grotowski, K.

1978-02-01

In widely separated locations in both hemispheres, we have found a significant correlation between the increased concentrations of /sup 210/Pb in glacier ice and periods of nuclear tests. The concentrations of /sup 210/Pb fluctuated concurrently with /sup 137/Cs concentrations in all glaciers studied, except for a temperate glacier in the Alps, exposed to the effects of summer heat. The most strict concurrence of fluctuation of these nuclides was observed in Spitsbergen, a location comparatively close to the arctic testing grounds. In 1973, a large excursion of /sup 210/Pb concentration was observed in all glaciers studied south of the arctic, presumablymore » after testing an advanced thermonuclear device at Lob Nor. The concurrence of concentrations of /sup 210/Pb, /sup 137/Cs, and /sup 90/Sr was observed in samples of stratospheric aerosols collected at an altitude of 12 km. This indicates that a part of the /sup 210/Pb present in the environment was produced, together with fission products, by nuclear explosions.« less

Physicochemical and toxicological characteristics of welding fume derived particles generated from real time welding processes.

PubMed

Chang, Cali; Demokritou, Philip; Shafer, Martin; Christiani, David

2013-01-01

Welding fume particles have been well studied in the past; however, most studies have examined welding fumes generated from machine models rather than actual exposures. Furthermore, the link between physicochemical and toxicological properties of welding fume particles has not been well understood. This study aims to investigate the physicochemical properties of particles derived during real time welding processes generated during actual welding processes and to assess the particle size specific toxicological properties. A compact cascade impactor (Harvard CCI) was stationed within the welding booth to sample particles by size. Size fractionated particles were extracted and used for both off-line physicochemical analysis and in vitro cellular toxicological characterization. Each size fraction was analyzed for ions, elemental compositions, and mass concentration. Furthermore, real time optical particle monitors (DustTrak™, TSI Inc., Shoreview, Minn.) were used in the same welding booth to collect real time PM2.5 particle number concentration data. The sampled particles were extracted from the polyurethane foam (PUF) impaction substrates using a previously developed and validated protocol, and used in a cellular assay to assess oxidative stress. By mass, welding aerosols were found to be in coarse (PM 2.5–10), and fine (PM 0.1–2.5) size ranges. Most of the water soluble (WS) metals presented higher concentrations in the coarse size range with some exceptions such as sodium, which presented elevated concentration in the PM 0.1 size range. In vitro data showed size specific dependency, with the fine and ultrafine size ranges having the highest reactive oxygen species (ROS) activity. Additionally, this study suggests a possible correlation between welders' experience, the welding procedure and equipment used and particles generated from welding fumes. Mass concentrations and total metal and water soluble metal concentrations of welding fume particles may be greatly influenced by these factors. Furthermore, the results also confirmed the hypothesis that smaller particles generate more ROS activity and should be evaluated carefully for risk assessment.

Calculations of critical micelle concentration by dissipative particle dynamics simulations: the role of chain rigidity.

PubMed

Lee, Ming-Tsung; Vishnyakov, Aleksey; Neimark, Alexander V

2013-09-05

Micelle formation in surfactant solutions is a self-assembly process governed by complex interplay of solvent-mediated interactions between hydrophilic and hydrophobic groups, which are commonly called heads and tails. However, the head-tail repulsion is not the only factor affecting the micelle formation. For the first time, we present a systematic study of the effect of chain rigidity on critical micelle concentration and micelle size, which is performed with the dissipative particle dynamics simulation method. Rigidity of the coarse-grained surfactant molecule was controlled by the harmonic bonds set between the second-neighbor beads. Compared to flexible molecules with the nearest-neighbor bonds being the only type of bonded interactions, rigid molecules exhibited a lower critical micelle concentration and formed larger and better-defined micelles. By varying the strength of head-tail repulsion and the chain rigidity, we constructed two-dimensional diagrams presenting how the critical micelle concentration and aggregation number depend on these parameters. We found that the solutions of flexible and rigid molecules that exhibited approximately the same critical micelle concentration could differ substantially in the micelle size and shape depending on the chain rigidity. With the increase of surfactant concentration, primary micelles of more rigid molecules were found less keen to agglomeration and formation of nonspherical aggregates characteristic of flexible molecules.

Assessment of diesel particulate matter exposure in the workplace: freight terminals†

PubMed Central

Sheesley, Rebecca J.; Schauer, James J.; Smith, Thomas J.; Garshick, Eric; Laden, Francine; Marr, Linsey C.; Molina, Luisa T.

2008-01-01

A large study has been undertaken to assess the exposure to diesel exhaust within diesel trucking terminals. A critical component of this assessment is an analysis of the variation in carbonaceous particulate matter (PM) across trucking terminal locations; consistency in the primary sources can be effectively tracked by analyzing trends in elemental carbon (EC) and organic molecular marker concentrations. Ambient samples were collected at yard, dock and repair shop work stations in 7 terminals in the USA and 1 in Mexico. Concentrations of EC ranged from 0.2 to 12 μg m−3 among the terminals, which corresponds to the range seen in the concentration of summed hopanes (0.5 to 20.5 ng m−3). However, when chemical mass balance (CMB) source apportionment results were presented as percent contribution to organic carbon (OC) concentrations, the contribution of mobile sources to OC are similar among the terminals in different cities. The average mobile source percent contribution to OC was 75.3 ± 17.1% for truck repair shops, 65.4 ± 20.4% for the docks and 38.4 ± 9.5% for the terminal yard samples. A relatively consistent mobile source impact was present at all the terminals only when considering percentage of total OC concentrations, not in terms of absolute concentrations. PMID:18392272

Study of large nonlinear change phase in Hibiscus Sabdariffa

NASA Astrophysics Data System (ADS)

Trejo-Durán, M.; Alvarado-Méndez, E.; Andrade-Lucio, J. A.; Rojas-Laguna, R.; Vázquez-Guevara, M. A.

2015-09-01

High intensities electromagnetic energy interacting with organic media gives rise to nonlinear optical effects. Hibiscus Sabdariffa is a flower whose concentrated solution presents interesting nonlinear optical properties. This organic material shows an important self-phase modulation with changes bigger than 2π. We present a diffraction ring patterns study of the Hibiscus Sabdariffa solution. Numerical results of transmittance, with refraction and simultaneous absorption, are shown.

A perfusion study of the handling of urea and urea analogues by the gills of the dogfish shark (Squalus acanthias)

PubMed Central

Liew, Hon Jung; De Boeck, Gudrun; Walsh, Patrick J.

2013-01-01

The branchial mechanism of urea retention in elasmobranchs was investigated using an in vitro isolated-perfused head preparation, as well as in vivo samples, in the spiny dogfish shark. Both in vivo and in control saline perfusions containing 350 mmol L−1 urea, calculated intracellular urea concentrations in gill epithelial cells were close to extracellular concentrations. Urea efflux to the external water fell only non-significantly, and calculated gill intracellular urea concentration did not change when perfusate urea concentration was reduced from 350 to 175 mmol L−1 with osmotic compensation by 175 mmol L−1 mannitol. However, when the urea analogues thiourea or acetamide were present in the perfusate at concentrations equimolar (175 mmol L−1) to those of urea (175 mmol L−1), urea efflux rates were increased 4-fold and 6.5-fold respectively, and calculated gill intracellular urea concentrations were depressed by about 55%. Analogue efflux rates were similar to urea efflux rates. Previous studies have argued that either the basolateral or apical membranes provided the limiting permeability barrier, and/or that a back-transporter on the basolateral membranes of gill cells is responsible for urea retention. The present results provide new evidence that the apical membrane is the limiting factor in maintaining gill urea impermeability, and raise the prospect that a urea back-transporter, which can be competitively inhibited by thiourea and acetamide, operates at the apical membrane. PMID:23638369

Water-quality assessment of the Albemarle-Pamlico drainage basin, North Carolina and Virginia; trace elements in Asiatic clam (Corbicula fluminea) soft tissues and redbreast sunfish (Lepomis auritus) livers, 1992-93

USGS Publications Warehouse

Ruhl, P.M.; Smith, K.E.

1996-01-01

The analysis of potential contaminants in biological tissues is an important part of many water-quality assessment programs, including the National Water-Quality Assessment (NAWQA) Program. Tissue analyses often are used to provide information about (1) direct threats to ecosystem integrity, and (2) the occurrence and distribution of potential contaminants in the environment. During 1992-93, trace elements in Asiatic clam (Corbicula fluminea) soft tissues and redbreast sunfish (Lepomis auritus) livers were analyzed to obtain information about the occurrence and distribution of trace element contaminants in the Albemarle-Pamlico Drainage Basin of North Carolina and Virginia. The investigation was conducted as part of the NAWQA Program. All but 3 of the 22 trace elements that were analyzed were detected. Although all 10 of the U.S. Environmental Protection Agency (U.S. EPA) priority pollutants were detected in the tissues sampled, they were present in relatively low concentrations. Concentrations of U.S. EPA priority pollutants in Asiatic clams collected in the Albemarle-Pamlico Drainage Basin are similar to concentrations observed in other NAWQA study units in the southeastern United States. Mercury (a U.S. EPA priority pollutant) was widely detected, being present in 29 of 30 tissue samples, but concentrations did not exceed the FDA action level for mercury of a risk-based screening value for the general public. Mercury concentrations in Asiatic clams were similar to concentrations in other NAWQA study areas in the Southeast.

In vitro selection of resistance in Escherichia coli and Klebsiella spp. at in vivo fluoroquinolone concentrations

PubMed Central

2010-01-01

Background Fluoroquinolones are potent antimicrobial agents used for the treatment of a wide variety of community- and nosocomial- infections. However, resistance to fluoroquinolones in Enterobacteriaceae is increasingly reported. Studies assessing the ability of fluoroquinolones to select for resistance have often used antimicrobial concentrations quite different from those actually acquired at the site of infection. The present study compared the ability to select for resistance of levofloxacin, ciprofloxacin and prulifloxacin at concentrations observed in vivo in twenty strains of Escherichia coli and Klebsiella spp. isolated from patients with respiratory and urinary infections. The frequencies of spontaneous single-step mutations at plasma peak and trough antibiotic concentrations were calculated. Multi-step selection of resistance was evaluated by performing 10 serial cultures on agar plates containing a linear gradient from trough to peak antimicrobial concentrations, followed by 10 subcultures on antibiotic-free agar. E. coli resistant strains selected after multi-step selection were characterized for DNA mutations by sequencing gyrA, gyrB, parC and parE genes. Results Frequencies of mutations for levofloxacin and ciprofloxacin were less than 10-11 at peak concentration, while for prulifloxacin they ranged from <10-11 to 10-5. The lowest number of resistant mutants after multistep selection was selected by levofloxacin followed by ciprofloxacin and prulifloxacin. Both ciprofloxacin- and prulifloxacin-resistant mutants presented mutations in gyrA and parC, while levofloxacin resistance was found associated only to mutations in gyrA. Conclusions Among the tested fluoroquinolones, levofloxacin was the most capable of limiting the occurrence of resistance. PMID:20409341

Evaluation of initial plasma lactate values as a predictor of gastric necrosis and initial and subsequent plasma lactate values as a predictor of survival in dogs with gastric dilatation-volvulus: 84 dogs (2003-2007).

PubMed

Green, Tiffany I; Tonozzi, Caroline C; Kirby, Rebecca; Rudloff, Elke

2011-02-01

To test whether an initial plasma lactate ≥ 6.0 mmol/L is associated with the presence of macroscopic gastric wall necrosis and overall survival in dogs presenting with gastric dilatation-volvulus (GDV). Additionally, if no association was identified we sought to identify a different predictive initial plasma lactate concentration and to examine whether serial plasma lactate concentrations provide better prediction of survival. Retrospective study over a 5-year period (2003-2007). Urban private referral small animal teaching hospital. Eighty-four client-owned dogs with a diagnosis of GDV and plasma lactate measurements. None. There was no statistically significant relationship found between survival and the presence of macroscopic gastric wall necrosis with the initial plasma lactate ≥ 6 mmol/L. There was a significant relationship between the initial plasma lactate >2.9 mmol/L for predicting necrosis and <4.1 mmol/L for predicting survival to discharge. Forty dogs that had an increased initial plasma lactate (>2.5 mmol/L) also had a subsequent plasma lactate measured within 12 hours of presentation, with 37/40 dogs surviving and 70% of these surviving dogs having the subsequent lactate decrease by ≥ 50% within 12 hours. The 3/40 that died failed to decrease their plasma lactate by ≥ 50% from the initial blood lactate. The results of this study indicate that an initial presenting plasma lactate concentration ≥ 6.0 mmol/L is not predictive of macroscopic gastric wall necrosis or survival in dogs presenting with GDV. A decrease in plasma lactate concentrations ≥ 50% within 12 hours may be a good indicator for survival. Limitations to the study include its retrospective nature, the small number of patients, and the number of dogs that were euthanized rather than allowed to progress to a natural outcome. © Veterinary Emergency and Critical Care Society 2011.

Nitrogen removal capacity and bacterial community dynamics of a Canon biofilter system at different organic matter concentrations.

PubMed

García-Ruiz, María J; Maza-Márquez, Paula; González-López, Jesús; Osorio, Francisco

2018-02-01

Three Canon bench-scale bioreactors with a volume of 2 L operating in parallel were configured as submerged biofilters. In the present study we investigated the effects of a high ammonium concentration (320 mgNH 4 + · L -1 ) and different concentrations of organic matter (0, 100 and 400 mgCOD·L -1 ) on the nitrogen removal capacity and the bacterial community structure. After 60 days, the Canon biofilters operated properly under concentrations of 0 and 100 mgCOD·L -1 of organic matter, with nitrogen removal efficiencies up to 85%. However, a higher concentration of organic matter (400 mgCOD·L -1 ) produced a partial inhibition of nitrogen removal (68.1% efficiency). The addition of higher concentrations of organic matter a modified the bacterial community structure in the Canon biofilter, increasing the proliferation of heterotrophic bacteria related to the genera of Thauera, Longilinea, Ornatilinea, Thermomarinilinea, unclassified Chlorobiales and Denitratisoma. However, heterotrophic bacteria co-exist with Nitrosomonas and Candidatus Scalindua. Thus, our study confirms the co-existence of different microbial activities (AOB, Anammox and denitrification) and the adaptation of a fixed-biofilm system to different concentrations of organic matter. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heavy metal concentrations in redeveloping soil of mine spoil under plantations of certain native woody species in dry tropical environment, India.

PubMed

Singh, Anand N; Zeng, De-hui; Chen, Fu-sheng

2005-01-01

Total concentration of heavy metals (Cd, Cr, Cu, Fe, Pb, Ni, Mn and Zn) was estimated in the redeveloping soil of mine spoil under 5-yr old plantations of four woody species namely: Albizia lebbeck, Albizia procera, Tectona grandis and Dendrocalamus strictus. The data recorded in the present study were compared with other unplanted coal mine spoil colliery, which was around to the study site and adjoining area of dry tropical forest. Among all the heavy metals, the maximum concentration was found for Fe and minimum for Cd. However, among all four species, total concentrations of these heavy metals were recorded maximally in the plantation plots of T. grandis except for Fe, while minimally in A. lebbeck except for Zn, whereas, the maximum concentration of Fe and Zn was in the plantation plots of D. strictus and A. procera. Statistical analysis revealed significant differences due to species for all the heavy metals except Cu. Among four species, A. lebbeck, A. procera and D. strictus showed more efficient for reducing heavy metal concentrations whereas T. grandis was not more effective to reduce heavy metal concentrations in redeveloping soil of mine spoil.

Fish pollution with anthropogenic 137Cs in the southern Baltic Sea.

PubMed

Zalewska, Tamara; Suplińska, Maria

2013-02-01

This paper presents the results of a study on changes in (137)Cs activity concentrations in three fish species from the southern Baltic Sea: cod (Gadus morhua), herring (Clupea harengus) and flounder (Platichtys flesus), in the period 2000-2010. During the study period a marked decline in cesium activity concentration in fish muscle tissue was observed, which reflected changes in radionuclide activity concentration in seawater. No statistically significant temporal trends were determined in changes of concentration factors (CF(fish/seawater)) calculated for the examined fish species. The analysis of (137)Cs activity as a function of ichthyological parameters revealed the lack of a relationship between radionuclide activity concentrations in herring muscle tissue and the fish age in an narrow age range (2-4 years). However, a reverse proportionality of total fish mass, as well as body length, against (137)Cs activity concentrations in muscles was well documented. The latter observation can be the direct result of the dilution effect related to the increase of fish body weight. (137)Cs activity concentration in muscle tissue of the five fish species forms a declining sequence: Gadus morhua, Platichthys flesus, Clupea harengus, Perca fluviatilis and Neogobius melanostomus. Copyright © 2012 Elsevier Ltd. All rights reserved.

Social Studies Doctoral Dissertations in the United States and Turkey: A Comparative Study

ERIC Educational Resources Information Center

Savas, Behsat

2016-01-01

This study delves into 169 social studies doctoral dissertations published from January 2012 to October 2015. The results of the included studies were qualitatively synthesized and presented in narrative form in the results section. In preliminary searching for systematic reviews concerning social studies, we concentrated on 169 doctoral…

Human immunodeficiency virus type 1 RNA in breast-milk components.

PubMed

Hoffman, Irving F; Martinson, Francis E A; Stewart, Paul W; Chilongozi, David A; Leu, Szu-Yun; Kazembe, Peter N; Banda, Topia; Dzinyemba, Willard; Joshi, Priya; Cohen, Myron S; Fiscus, Susan A

2003-10-15

We conducted the present study to determine which of the 4 components of breast milk (whole milk, skim milk, lipid layer, and breast-milk cells) had the highest sensitivity and concentration of human immunodeficiency virus (HIV) type 1 RNA burden and to determine biological correlates to these factors. The probability of detection of HIV (sensitivity) and the concentration of HIV-1 RNA were both associated with the choice of milk component, CD4(+) cell count, concentration of blood serum HIV-1 RNA, and the presence of breast inflammation. Whole milk demonstrated higher sensitivity and mean concentration than any other single component. Sensitivity was enhanced by analyzing all 4 components of breast milk.

The Impact of Aerosols on Cloud and Precipitation Processes: Cloud-Resolving Model Simulations

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo; Li, Xiaowen; Khain, Alexander; Matsui, Toshihisa; Lang, Stephen; Simpson, Joanne

2012-01-01

Recently, a detailed spectral-bin microphysical scheme was implemented into the Goddard Cumulus Ensemble (GCE) model. Atmospheric aerosols are also described using number density size-distribution functions. A spectral-bin microphysical model is very expensive from a computational point of view and has only been implemented into the 2D version of the GCE at the present time. The model is tested by studying the evolution of deep tropical clouds in the west Pacific warm pool region and summertime convection over a mid-latitude continent with different concentrations of CCN: a low clean concentration and a high dirty concentration. The impact of atmospheric aerosol concentration on cloud and precipitation will be investigated.

Optical properties of nonimaging concentrators with corrugated reflectors

NASA Astrophysics Data System (ADS)

Roennelid, Mats; Perers, Bengt; Karlsson, Bjorn

1994-09-01

A ray tracing study has been performed on the optical properties of cylindrical nonimaging concentrators with linear corrugated reflectors. The corrugations are assumed to be V-formed and to have an extension parallel to the meridian plane of the concentrators. It is shown that the acceptance angle for radiation incident in the meridian plane can be increased for moderate corrugations. This increased acceptance is balanced by a decreased acceptance of radiation from other directions. Calculations of angular acceptance for a 2X compound parabolic concentrator is presented. It is shown that the annual irradiation on a solar collector with booster reflector can be increased if corrugated reflectors are used instead of smooth reflectors.

Research of CO2 concentration in naturally ventilated lecture room

NASA Astrophysics Data System (ADS)

Laska, Marta; Dudkiewicz, Edyta

2017-11-01

Naturally ventilated buildings especially dedicated for educational purposes need to be design to achieve required level of thermal comfort and indoor air quality. It is crucial in terms of both: health and productivity of the room users. Higher requirements of indoor environment are important due to the level of students concentration, their ability to acquire new knowledge and willingness to interact with the lecturer. The article presents the results of experimental study and surveys undertaken in naturally ventilated lecture room. The data is analysed in terms of CO2 concentration and its possible influence on users. Furthermore the outcome of the research is compared with the CO2 concentration models available in the literature.

DISTRIBUTION OF URANIUM, ZIRCONIUM, NIOBIUM, RUTHENIUM AND CERIUM BETWEEN NITRIC ACID SOLUTIONS AND 10% TLA-5% OCTYL ALCOHOL/SHELL SOL-T

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

Lopez-Menchero, E.; Centeno, J.; Magni, G.

1962-03-01

The extraction of traces of Ru, Zr, Nb, Ce, and U at low concentrations (5 mg/l in aqueous solution) from nitric acid solutions using trilauryl amine (TLA) has been experimentally studied. TLA will eventually be used for final purification of plutonium. Room-temperature data on plutonium contaminant distribution between aqueous solutions of varying nitric acid concentrations and a Shellsol-T solution containing l0% TlA and 5% octyl alcohol are presented. Within the temperature and nitric acid concentration ranges tested, the extractability of uranium increased with increased acid concentrations, although acid concentration in the aqueous phase had no effect on the decontamination factorsmore » for the main fission products. (H.G.G.)« less

Human Mercury Exposure in Yanomami Indigenous Villages from the Brazilian Amazon.

PubMed

Vega, Claudia M; Orellana, Jesem D Y; Oliveira, Marcos W; Hacon, Sandra S; Basta, Paulo C

2018-05-23

In the Brazilian Amazon, where the majority of Yanomami villages are settled, mercury (Hg) exposure due to artisanal small-scale gold mining (ASGM) has been reported since the 1980s. This study assessed mercury exposure in the Yanomami reserve and whether the level of contamination was related to the ASGM geographical location. It was conducted using a cross-sectional study of 19 villages. Direct interviews were performed and hair samples were used as a bioindicator of Hg exposure. The Prevalence-Ratio (PR) was estimated as an indicator of association between ASGM geographical locations and human exposure to mercury. Mercury levels (239 hair samples) ranged between 0.4 and 22.1 μg·g -1 and presented substantial differences amongst the villages. In the Waikas-Aracaça region, where current ASGM was reported, we observed the highest Hg concentrations (median = 15.5 μg·g -1 ). Almost all participants presented with hair-Hg levels >6 μg·g -1 (prevalence = 92.3%). In the Paapiu region, we observed the lowest concentrations (median = 3.2 μg·g -1 ; prevalence = 6.7%). Our findings showed that the Waikas Ye'kuana and Waikas Aracaca villages presented with 4.4 (PR = 4.4; Confidence Interval (CI) 95% = 2.2⁻9.0) and 14.0 (PR = 14.0; CI 95% = 7.9⁻24.9) times higher prevalence of hair-Hg concentration, respectively, compared with Paapiu. Considering seasonal variation of Hg-exposure, the lowest concentrations were observed during the wet season (June⁻September) and the highest in the dry season (December⁻April). Our study suggests that there is an association between mercury exposure and ASGM geographical locations.

Bone metabolism markers and vitamin D in adolescent cyclists.

PubMed

Olmedillas, Hugo; Gonzalez-Agüero, Alejandro; Rapún-López, Marta; Gracia-Marco, Luis; Gomez-Cabello, Alba; Pradas de la Fuente, Francisco; Moreno, Luís A; Casajús, José A; Vicente-Rodríguez, Germán

2018-02-03

This study aimed to describe bone metabolic activity in adolescent competitive cyclists compared to age-matched controls. The main result is that younger subjects present a higher bone turnover than the older ones. Moreover, cyclists under the age of 17 have higher scores on all markers than age-matched controls. The purpose of this study was to describe bone metabolic activity in adolescent competitive cyclists compared to age-matched controls. Twenty-two male adolescent cyclists between 14 and 20 years (y) and 20 age-matched controls participated in this study. Serum osteocalcin (OC), aminoterminal propeptide of type I procollagen (PINP), and β-isomerized C-telopeptides (β-CTX) were analyzed by electrochemiluminescence immunoassay (ECLIA); plasma 25 hydroxyvitamin D [25(OH)D] was analyzed by enzyme-linked immunosorbent assay (ELISA). Analysis of variance revealed no significant differences in bone metabolism markers and vitamin D between cyclists and controls. Cyclists over 17 y had a significantly lower concentration in bone formation and resorption biochemical markers compared to cyclists under 17 y (all P < 0.05). Moreover, controls over 17 y presented lower concentration for PINP (P < 0.05) compared to their peers under 17 y. Comparisons between cyclists and controls under 17 y revealed higher concentrations of OC and PINP (P < 0.05) in cyclists. Group interaction by age was found for OC, PINP, and β-CTX (P < 0.01). Cyclists over 17 y had higher concentrations of [25(OH)D] (P < 0.05) than age-matched controls. The present results support the idea that cycling during adolescence may be associated to a decrease in bone turnover that may affect bone health later in life.

Anadromous char as an alternate food choice to marine animals: a synthesis of Hg concentrations, population features and other influencing factors.

PubMed

Evans, Marlene S; Muir, Derek C G; Keating, Jonathan; Wang, Xiaowa

2015-03-15

This study was conducted to confirm sporadic measurements made over the late 1970s to the early 1990 s which determined that mercury (Hg) concentrations were low in anadromous char across Arctic and subarctic Canada including northern Québec and Labrador. Over 2004-2013, anadromous char populations across northern Canada were investigated at 20 sites for Hg concentrations and life history characteristics. Hg concentrations were extremely low in anadromous char muscle, typically <0.05 μg/g (wet weight) and, at each location, generally increased with fish length, age and nitrogen isotope (δ(15)N) ratio and decreased with condition factor and %lipid; correlations with carbon isotope (δ(13)C) ratio were inconsistent. Location and year were significant variables influencing Hg concentrations over the study area; longitude and latitude also were significant influencing variables. Char length, weight, age, condition factor and lipid content explained additional variance. A tendency towards higher Hg concentrations with increasing latitude may be partially related to decreasing growth of char towards the north. However, Hg concentrations in char were positively correlated with growth rates suggesting that Hg concentrations in char also were higher in the more productive study areas, including to the west where mainland riverine inputs of terrestrial carbon, nutrients, and Hg were greater. The data base for assessing time trends in char was limited by the small number of years investigated at most locations, variable fish size across years, small sample size, etc. Where temporal trends were detected, they were of increase on the long term (1970s, 1980s or early 1990 s to the present) but of decrease on the short term (early 2000s to present) with Nain (Labrador) showing the converse pattern. Higher Hg concentrations were also related to lower condition factor and cooler springs. Hg concentrations in anadromous char are compared with other terrestrial, aquatic and marine vertebrates in traditional diets. The known information on anadromous char is reviewed including population features, habitat, and harvests. Future Hg trend monitoring should focus on specific locations and harvest areas within these areas to better assess trends and influencing factors. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Pharmacokinetic-Pharmacodynamic Modeling of Enrofloxacin Against Escherichia coli in Broilers.

PubMed

Sang, KaNa; Hao, HaiHong; Huang, LingLi; Wang, Xu; Yuan, ZongHui

2015-01-01

The purpose of the present study was to establish a pharmacokinetic/pharmacodynamic (PK/PD) modeling approach for the dosage schedule design and decreasing the emergence of drug-resistant bacteria. The minimal inhibitory concentration (MIC) of 929 Escherichia coli isolates from broilers to enrofloxacin and ciprofloxacin was determined following CLSI guidance. The MIC50 was calculated as the populational PD parameter for enrofloxacin against E. coli in broilers. The 101 E. coli strains with MIC closest to the MIC50 (0.05 μg/mL) were submitted for serotype identification. The 13 E. coli strains with O and K serotype were further utilized for determining pathogencity in mice. Of all the strains tested, the E. coli designated strain Anhui 112 was selected for establishing the disease model and PK/PD study. The PKs of enrofloxacin after oral administration at the dose of 10 mg/kg body weights (BW) in healthy and infected broilers was evaluated with high-performance liquid chromatography (HPLC) method. For intestinal contents after oral administration, the peak concentration (C max), the time when the maximum concentration reached (T max), and the area under the concentration-time curve (AUC) were 21.69-31.69 μg/mL, 1.13-1.23 h, and 228.97-444.86 μg h/mL, respectively. The MIC and minimal bactericidal concentration (MBC) of enrofloxacin against E. coli (Anhui 112) in Mueller-Hinton (MH) broth and intestinal contents were determined to be similar, 0.25 and 0.5 μg/mL respectively. In this study, the sum of concentrations of enrofloxacin and its metabolite (ciprofloxacin) was used for the PK/PD integration and modeling. The ex vivo growth inhibition data were fitted to the sigmoid E max (Hill) equation to provide values for intestinal contents of 24 h area under concentration-time curve/MIC ratios (AUC0-24 h/MIC) producing, bacteriostasis (624.94 h), bactericidal activity (1065.93 h) and bacterial eradication (1343.81 h). PK/PD modeling was established to simulate the efficacy of enrofloxacin for different dosage regimens. By model validation, the protection rate was 83.3%, demonstrating that the dosage regimen of 11.9 mg/kg BW every 24 h during 3 days provided great therapeutic significance. In summary, the purpose of the present study was to first design a dosage regimen for the treatment E. coli in broilers by enrofloxacin using PK/PD integrate model and confirm that this dosage regimen presents less risk for emergence of floroquinolone resistance.

Estimation of Satellite-Based SO42- and NH4+ Composition of Ambient Fine Particulate Matter Over China Using Chemical Transport Model

NASA Astrophysics Data System (ADS)

Si, Y.; Li, S.; Chen, L.; Yu, C.; Zhu, W.

2018-04-01

Epidemiologic and health impact studies have examined the chemical composition of ambient PM2.5 in China but have been constrained by the paucity of long-term ground measurements. Using the GEOS-Chem chemical transport model and satellite-derived PM2.5 data, sulfate and ammonium levels were estimated over China from 2004 to 2014. A comparison of the satellite-estimated dataset with model simulations based on ground measurements obtained from the literature indicated our results are more accurate. Using satellite-derived PM2.5 data with a spatial resolution of 0.1° × 0.1°, we further presented finer satellite-estimated sulfate and ammonium concentrations in anthropogenic polluted regions, including the NCP (the North China Plain), the SCB (the Sichuan Basin) and the PRD (the Pearl River Delta). Linear regression results obtained on a national scale yielded an r value of 0.62, NMB of -35.9 %, NME of 48.2 %, ARB_50 % of 53.68 % for sulfate and an r value of 0.63, slope of 0.67, and intercept of 5.14 for ammonium. In typical regions, the satellite-derived dataset was significantly robust. Based on the satellite-derived dataset, the spatial-temporal variation of 11-year annual average satellite-derived SO42- and NH4+ concentrations and time series of monthly average concentrations were also investigated. On a national scale, both exhibited a downward trend each year between 2004 and 2014 (SO42-: -0.61 %; NH4+: -0.21 %), large values were mainly concentrated in the NCP and SCB. For regions captured at a finer resolution, the inter-annual variation trends presented a positive trend over the periods 2004-2007 and 2008-2011, followed by a negative trend over the period 2012-2014, and sulfate concentrations varied appreciably. Moreover, the seasonal distributions of the 11-year satellite-derived dataset over China were presented. The distribution of both sulfate and ammonium concentrations exhibited seasonal characteristics, with the seasonal concentrations ranking as follows: winter > summer > autumn > spring. High concentrations of these species were concentrated in the NCP and SCB, originating from coal-fired power plants and agricultural activities, respectively. Efforts to reduce sulfur dioxide (SO2) emissions have yielded remarkable results since the government has adopted stricter control measures in recent years. Moreover, ammonia emissions should be controlled while reducing the concentration of sulfur, nitrogen and particulate matter. This study provides an assessment of the population's exposure to certain chemical components.

Lead levels in deciduous teeth of children in Bahrain.

PubMed

al-Mahroos, F; al-Saleh, F S

1997-06-01

To determine lead exposure among children in Bahrain, a total of 280 shed deciduous whole teeth were collected from 269 children. Teeth were analyzed for lead concentrations using atomic absorption spectrophotometry with electrothermal atomization. Children were between 5 and 15 years old. The study period extended from July 1993 to April 1994. The study showed that the overall mean tooth-lead level was 4.3 micrograms/g dry weight with a range of 0.1-60.8 micrograms/g dry weight. The cumulative frequency distribution revealed that 35% of the teeth had a lead concentration of more than 4 micrograms/g dry weight. The tooth-lead concentrations differed according to the tooth type age. The child's sex, nationality, area of residence and socio-economic status had no impact on tooth-lead level. In conclusion, lead is present in toxic concentrations in 35% of the teeth of the children studied. Urgent measures are needed to eliminate lead from gasoline, paint and other sources in the environment.

Increase in serum concentrations of IgG2 and IgG4 by selenium supplementation in children with Down's syndrome.

PubMed Central

Annerén, G; Magnusson, C G; Nordvall, S L

1990-01-01

In a previous study on children with Down's syndrome a reduced rate of infections was reported by their parents after the children had received six months' treatment with selenium supplements. In the present study the concentrations of the four IgG subclasses were measured in 29 of these children in samples of serum obtained before and immediately after the period of supplementation and one year after it had finished. Selenium had a significant augmentative effect on the serum concentrations of IgG2 and IgG4, but not of IgG1 and IgG3. This effect was not related to age, as among children over the age of 6 years the serum concentrations of IgG2 and IgG4 had decreased significantly one year after the treatment had been stopped. This study suggests that selenium has an immunoregulatory effect, which might be of importance in both basic research and clinical practice. PMID:2148668

Omega-3 fatty acid concentrate from Dunaliella salina possesses anti-inflammatory properties including blockade of NF-κB nuclear translocation.

PubMed

Chitranjali, T; Anoop Chandran, P; Muraleedhara Kurup, G

2015-02-01

The health benefits of omega-3 polyunsaturated fatty acids (ω-3 PUFA), mainly eicosapentaenoic acid (EPA 20:5) and docosahexaenoic acid (DHA, 22:6), have been long known. Although various studies have demonstrated the health benefits of ω-3 PUFA, the mechanisms of action of ω-3 PUFAs are still not completely understood. While the major commercial source is marine fish oil, in this study we suggest the marine micro algae, Dunaliella salina as an alternate source of omega-3 fatty acids. Treatment with this algal omega-3 fatty acid concentrate (Ds-ω-3 FA) resulted in significant down-regulation of LPS-induced production of TNF-α and IL-6 by peripheral blood mononuclear cells (PBMCs). The concentrate was also found to be a potent blocker of cyclooxygenase (COX-2) and matrix metalloproteinase (MMP-2 and MMP-9) expression. The present study reveals the anti-inflammatory properties of Ds-ω-3 FA concentrate including the inhibition of NF-κB translocation.

Pollutant bioaccumulation in the California spiny lobster (Panulirus interruptus) in San Diego Bay, California, and potential human health implications.

PubMed

Loflen, Chad L; Buck, Travis; Bonnema, Autumn; Heim, Wesley A

2018-03-01

While the California spiny lobster (Panulirus interruptus) is an important commercial and recreational fishery species in California, there is a lack of data on bioaccumulation for the species. This study examined pollutant tissue concentrations in lobsters from San Diego Bay, California. Observed lobster pollutant tissue concentrations in tail muscle were compared to State of California pollutant advisory levels. Concentrations were then used to conduct risk assessment using catch data from the California Department of Fish and Wildlife. Study results found little bioaccumulation of organic pollutants in tail tissue, likely due to low observed lipids. Mercury was present, predominantly in methyl form, at concentrations above advisory levels. Recreational catch data for San Diego Bay showed increased non-cancer risk for fishers at the 90th percentile or greater of reported annual catch. Further studies should focus on non-tail tissues, as exploratory whole lobster samples (n = 2) showed elevated organic pollutants and metals. Copyright © 2018 Elsevier Ltd. All rights reserved.

New investigation of the isothermal oxidation of extra virgin olive oil: determination of free radicals, total polyphenols, total antioxidant capacity, and kinetic data.

PubMed

Amati, Lucia; Campanella, Luigi; Dragone, Roberto; Nuccilli, Adriano; Tomassetti, Mauro; Vecchio, Stefano

2008-09-24

As a follow-up of the research programs carried out by our group concerning the artificial isothermal rancidification process in extra virgin olive oil (EVOO), in the present work the trends of both the total antioxidant capacity and the total polyphenols concentration as well as the main kinetic parameters of the process during the thermal oxidation of EVOO were studied and compared. In addition, the possibility of evaluating the increase in radicals concentration during the thermal oxidation process using a superoxide dismutase biosensor was also studied. The present investigation concerning this important food product is highly topical as it refers to the state of alteration of the EVOO used for cooking or frying, as a function of the temperature reached.

Hazardous radioactivity levels and heavy mineral concentrations in beach sediments of Lake Peipsi, northeastern Estonia

NASA Astrophysics Data System (ADS)

Järvelill, Johanna-Iisebel; Koch, Rein; Raukas, Anto; Vaasma, Tiit

2018-03-01

The present study discusses results of heavy mineral analyses and radioactivity of beach sediments of Lake Peipsi. Such analyses are commonly done globally, but had not yet been conducted for the fourth largest lake in Europe. The average heavy mineral content in Lake Peipsi beach sediments along the northern and western coast is higher than usual for Estonian coastal and Quaternary sediments. Concomitantly, elevated radioactivity levels have been measured in several places, with the highest concentrations observed at Alajõe (1885.5 Bq/kg), which is over five times more than the recommended limit. The aim of the present study is to find sites with higher radioactivity levels, because the northern coast of Lake Peipsi is a well-known recreational area.

Toxicity of environmentally realistic concentrations of chlorpyrifos and terbuthylazine in indoor microcosms.

PubMed

Pereira, Ana Santos; Cerejeira, Maria José; Daam, Michiel A

2017-09-01

Few studies have been conducted into the evaluation of environmentally realistic pesticide mixtures using model ecosystems. In the present study, the effects of single and combined environmentally realistic concentrations of the herbicide terbuthylazine and the insecticide chlorpyrifos were evaluated using laboratory microcosms. Direct toxic effects of chlorpyrifos were noted on copepod nauplii and cladocerans and the recovery of the latter was likely related with the decrease observed in rotifer abundances. Terbuthylazine potentiated the effect of chlorpyrifos on feeding rates of Daphnia magna, presumably by triggering the transformation of chlorpyrifos to more toxic oxon-analogs. Possible food-web interactions resulting from multiple chemical (and other) stressors likely to be present in edge-of-field water bodies need to be further evaluated. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of advanced methods for analysis of experimental data in diffusion

NASA Astrophysics Data System (ADS)

Jaques, Alonso V.

There are numerous experimental configurations and data analysis techniques for the characterization of diffusion phenomena. However, the mathematical methods for estimating diffusivities traditionally do not take into account the effects of experimental errors in the data, and often require smooth, noiseless data sets to perform the necessary analysis steps. The current methods used for data smoothing require strong assumptions which can introduce numerical "artifacts" into the data, affecting confidence in the estimated parameters. The Boltzmann-Matano method is used extensively in the determination of concentration - dependent diffusivities, D(C), in alloys. In the course of analyzing experimental data, numerical integrations and differentiations of the concentration profile are performed. These methods require smoothing of the data prior to analysis. We present here an approach to the Boltzmann-Matano method that is based on a regularization method to estimate a differentiation operation on the data, i.e., estimate the concentration gradient term, which is important in the analysis process for determining the diffusivity. This approach, therefore, has the potential to be less subjective, and in numerical simulations shows an increased accuracy in the estimated diffusion coefficients. We present a regression approach to estimate linear multicomponent diffusion coefficients that eliminates the need pre-treat or pre-condition the concentration profile. This approach fits the data to a functional form of the mathematical expression for the concentration profile, and allows us to determine the diffusivity matrix directly from the fitted parameters. Reformulation of the equation for the analytical solution is done in order to reduce the size of the problem and accelerate the convergence. The objective function for the regression can incorporate point estimations for error in the concentration, improving the statistical confidence in the estimated diffusivity matrix. Case studies are presented to demonstrate the reliability and the stability of the method. To the best of our knowledge there is no published analysis of the effects of experimental errors on the reliability of the estimates for the diffusivities. For the case of linear multicomponent diffusion, we analyze the effects of the instrument analytical spot size, positioning uncertainty, and concentration uncertainty on the resulting values of the diffusivities. These effects are studied using Monte Carlo method on simulated experimental data. Several useful scaling relationships were identified which allow more rigorous and quantitative estimates of the errors in the measured data, and are valuable for experimental design. To further analyze anomalous diffusion processes, where traditional diffusional transport equations do not hold, we explore the use of fractional calculus in analytically representing these processes is proposed. We use the fractional calculus approach for anomalous diffusion processes occurring through a finite plane sheet with one face held at a fixed concentration, the other held at zero, and the initial concentration within the sheet equal to zero. This problem is related to cases in nature where diffusion is enhanced relative to the classical process, and the order of differentiation is not necessarily a second--order differential equation. That is, differentiation is of fractional order alpha, where 1 ≤ alpha < 2. For alpha = 2, the presented solutions reduce to the classical second-order diffusion solution for the conditions studied. The solution obtained allows the analysis of permeation experiments. Frequently, hydrogen diffusion is analyzed using electrochemical permeation methods using the traditional, Fickian-based theory. Experimental evidence shows the latter analytical approach is not always appropiate, because reported data shows qualitative (and quantitative) deviation from its theoretical scaling predictions. Preliminary analysis of data shows better agreement with fractional diffusion analysis when compared to traditional square-root scaling. Although there is a large amount of work in the estimation of the diffusivity from experimental data, reported studies typically present only the analytical description for the diffusivity, without scattering. However, because these studies do not consider effects produced by instrument analysis, their direct applicability is limited. We propose alternatives to address these, and to evaluate their influence on the final resulting diffusivity values.

Radionuclide activities and metal concentrations in sediments of the Sebou Estuary, NW Morocco, following a flooding event.

PubMed

Laissaoui, A; Mas, J L; Hurtado, S; Ziad, N; Villa, M; Benmansour, M

2013-06-01

This study presents metal concentrations (Fe, Mg, Mn, Co, Cu, Zn, Pb, As, Sr and V) and radionuclide activities ((40)K, (137)Cs, (210)Pb, (226)Ra, (228)Ac, (234)Th and (212)Pb) in surface deposits and a sediment core from the Sebou Estuary, Northwest Morocco. Samples were collected in April 2009, about 2 months after a flooding event, and analysed using a well-type coaxial gamma-ray detector and inductively coupled plasma-quadrupole mass spectrometry. Activities of radionuclides and concentrations of almost all elements in surface samples displayed only moderate spatial variation, suggesting homogenous deposition of eroded local soil in response to intense precipitation. Excess (210)Pb displayed relatively constant activity throughout the sediment core, preventing dating and precluding determination of the historical accumulation rates of pollutants at the core site. Some elements showed non-systematic trends with depth and displayed local maxima and minima. Other elements presented relatively systematic concentration trends or relatively constant levels with discrete maxima and/or minima. Except for Mn, Sr and Cr, all metal concentrations in sediment were below levels typical of polluted systems, suggesting little human impact or losses of metals from sediment particles.

Gonadal hormone levels and platelet tryptophan and serotonin concentrations in perimenopausal women with or without depressive symptoms.

PubMed

Flores-Ramos, Mónica; Moreno, Julia; Heinze, Gerhard; Aguilera-Pérez, Rafael; Pellicer Graham, Francisco

2014-03-01

The etiology of depressive symptoms associated with the transition to menopause is still unknown; hormonal changes, serotonergic system or insomnia, could be a trigger to depressive symptomatology. The aim of the present study was to evaluate gonadal hormonal levels, platelet serotonin concentrations and platelet tryptophan concentrations in a group of depressed perimenopausal women and their healthy counterparts. A total of 63 perimenopausal women between 45 and 55 years old were evaluated; of these, 44 were depressed patients, and 19 were perimenopausal women without depression. The instruments that were applied included the Center for Epidemiologic Studies Depression Scale (CES-D), the Hamilton Depression Rating Scale (HDRS) and the Green Climacteric Scale (GCS); gonadal hormone levels and platelet tryptophan and serotonin concentrations were measured in all participants. Differences in hormonal levels and tryptophan and serotonin concentrations were evaluated with respect to specific symptoms, such as insomnia, hot flashes, nervousness, depressed mood and loss of interest. No differences between groups were observed with respect to hormonal levels and tryptophan and serotonin concentrations; mean sleep hours and insomnia were significantly correlated with platelet tryptophan concentrations. In this sample, all symptoms of depression could not be explained by platelet tryptophan and serotonin concentrations and hormonal levels; differences were observed only when we evaluated insomnia and hot flashes.

Relationship between maternal sodium intake and blood lead concentration during pregnancy.

PubMed

Lee, Yo A; Hwang, Ji-Yun; Kim, Hyesook; Kim, Ki Nam; Ha, Eun-Hee; Park, Hyesook; Ha, Mina; Kim, Yangho; Hong, Yun-Chul; Chang, Namsoo

2013-03-14

Pb is released from bone stores during pregnancy, which constitutes a period of increased bone resorption. A high Na intake has been found to be negatively associated with Ca and adversely associated with bone metabolism. It is possible that a high Na intake during pregnancy increases the blood Pb concentration; however, no previous study has reported on the relationship between Na intake and blood Pb concentration. We thus have investigated this relationship between Na intake and blood Pb concentrations, and examined whether this relationship differs with Ca intake in pregnant Korean women. Blood Pb concentrations were analysed in 1090 pregnant women at mid-pregnancy. Dietary intakes during mid-pregnancy were estimated by a 24 h recall method covering the use of dietary supplements. Blood Pb concentrations in whole-blood samples were analysed using graphite furnace atomic absorption spectrophotometry. Multiple regression analysis performed after adjustment for covariates revealed that maternal Na intake was positively associated with blood Pb concentration during pregnancy, but only when Ca intake was below the estimated average requirement for pregnant Korean women (P= 0·001). The findings of the present study suggest that blood Pb concentration during pregnancy could be minimised by dietary recommendations that include decreased Na and increased Ca intakes.

Evaluation of pharmacokinetics and the stability of daptomycin in serum at various temperatures.

PubMed

Ogami, Chika; Tsuji, Yasuhiro; Kasai, Hidefumi; Hiraki, Yoichi; Yamamoto, Yoshihiro; Matsunaga, Kazuhisa; Karube, Yoshiharu; To, Hideto

2017-04-01

Daptomycin exhibits concentration-dependent antibacterial activity. By monitoring daptomycin serum concentrations, clinicians may be able to predict the effectiveness of treatments for infections more accurately. However, it has been reported that daptomycin concentrations in plasma samples stored at -20°C decrease approximately 25% after 4 weeks. The aim of this study was to evaluate the stability of daptomycin in serum at various temperatures. Daptomycin serum samples were prepared and stored at different temperatures. The stability of daptomycin under various conditions was evaluated by sequential measurements of concentration. Although the loss of concentration of daptomycin in serum samples stored in freezers (-80°C and -20°C) was less than 10% after 168days (6 months), the concentrations in samples stored in a refrigerator (4°C) decreased by more than 70% over the same period. Furthermore, daptomycin concentrations in serum samples stored at close to body temperature (35°C, 37°C, and 39°C) decreased by more than 50% after only 24h. The results of the present study demonstrate that the measurement of serum concentrations of daptomycin needs to be performed rapidly. Furthermore, the degradation of daptomycin in serum may be involved in its elimination from the living body. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Intrathecal expression of IL-5 and humoral response in patients with tick-borne encephalitis.

PubMed

Grygorczuk, Sambor; Czupryna, Piotr; Pancewicz, Sławomir; Świerzbińska, Renata; Kondrusik, Maciej; Dunaj, Justyna; Zajkowska, Joanna; Moniuszko-Malinowska, Anna

2018-05-01

The aim of the study was to assess the role of an early specific humoral response in human infection with a tick-borne encephalitis virus (TBEV) and the role of IL-5 as its potential mediator and marker. The retrospective study involved a cohort of 199 patients diagnosed with TBE, in whom anti-TBEV IgM and IgG antibody titers were analyzed on admission and compared with clinical presentation and basic laboratory parameters. The prospective study included 50 TBE patients in whom IL-5 serum and CSF concentration was measured with ELISA on admission in the TBE neurologic phase and in selected patients before discharge, at follow-up or in samples obtained before the neurologic phase onset. The serum anti-TBEV IgM correlated with good clinical outcome and the CSF anti-TBEV IgM with more pronounced CSF inflammation on admission, but also with its more complete resolution on follow-up. The serum anti-TBEV IgG correlated with milder presentation and better outcome. Concentration of IL-5 was increased in CSF but not in the serum of TBE patients. IL-5 concentration index on admission favored its intrathecal synthesis. IL-5 did not correlate significantly with clinical presentation and specific IgM and IgG titers. Specific anti-TBEV IgM systemic and intrathecal response and IgG systemic response are protective, together favoring milder presentation, better outcome and resolution of central nervous system (CNS) inflammation. IL-5 is expressed intrathecally in TBE, but its pathogenetic role remains unclear. Copyright © 2018 Elsevier GmbH. All rights reserved.

The effect of long-range atmospheric transport of organochlorine compounds by soil studies from Mongolia to the Arctic

NASA Astrophysics Data System (ADS)

Mamontova, E. A.; Tarasova, E. N.; Mamontov, A. A.; Kuzmin, M. I.

2016-02-01

The results of studies on the distribution regularities are presented for polychlorinated biphenyls (PCBs) of different degrees of chlorination and for organochlorine pesticides (OCPs): hexachlorobenzene (HCB), hexachlorocyclohexane (HCCH), and DDT with its metabolites in the soils along the Lena River valley and in background areas of Eastern Siberia and Mongolia. A statistically reliable correlation is found between the PCB-OCP and Corg concentrations. The highest levels of HCB are registered in the soils between 50 and 60° N. The concentrations of αand γ-HCCH increase reliably, while those of pp'-DDT and pp'-DDE decrease from south to north. A trend of the decrease in concentrations from Mongolia to the Laptev Sea is revealed for tri-, tetra-, and penta-chlorine-substituted PCB congeners. However, the soils sampled northwards from 60° N show a reliable increase in the concentrations of tetra-, penta-, and hexachlorine-substituted congeners.

Bioaccumulation of trace element concentrations in common dolphins (Delphinus delphis) from Portugal.

PubMed

Monteiro, Sílvia S; Pereira, Andreia T; Costa, Élia; Torres, Jordi; Oliveira, Isabel; Bastos-Santos, Jorge; Araújo, Helder; Ferreira, Marisa; Vingada, José; Eira, Catarina

2016-12-15

The common dolphin (Delphinus delphis) is one of the most abundant species in Atlantic Iberia, representing a potentially important tool to assess the bioaccumulation of trace elements in the Iberian marine ecosystem. Nine elements (As, Cd, Cu, Hg, Mn, Ni, Pb, Se and Zn) were evaluated in 36 dolphins stranded in continental Portugal. Dolphins had increasing Hg concentrations (16.72μg·g -1 ww, liver) compared with previous studies in Atlantic Iberia, whereas Cd concentrations (2.26μg·g -1 ww, kidney) fell within reported ranges. The concentrations of some trace elements (including Cd and Hg) presented positive relationships with dolphin length, presence of parasites and gross pathologies. Common dolphins may help biomonitoring more offshore Atlantic Iberian areas in future studies, which would otherwise be difficult to assess. Copyright © 2016 Elsevier Ltd. All rights reserved.

Electrodeposition of Metals in Microgravity Conditions

NASA Technical Reports Server (NTRS)

Nishikawa, K.; Homma, T.; Chassaing, E.; Rosso, M.; Fukunaka, Y.

2012-01-01

Metal electrodeposition may introduce various morphological variations depending on the electrolytic conditions including cell configurations. For liquid electrolytes, a precise study of these deposits may be complicated by convective motion due to buoyancy. Zero-gravity (0-G) condition provided by drop shaft or parabolic flight gives a straightforward mean to avoid this effect: we present here 0-G electrodeposition experiments, which we compare to ground experiments (1-G). Two electrochemical systems were studied by laser interferometry, allowing to measure the concentration variations in the electrolyte: copper deposition from copper sulfate aqueous solution and lithium deposition from an ionic liquid containing LiTFSI. For copper, concentration variations were in good agreement with theory. For lithium, an apparent induction time was observed for the concentration evolution at 1-G: due to this induction time and to the low diffusion coefficient in ionic liquid, the concentration variations were hardly measurable in the parabolic flight 0-G periods of 20 seconds.