Determination of microbial carbon sources and cycling during remediation of petroleum hydrocarbon impacted soil using natural abundance (14)C analysis of PLFA.

PubMed

Cowie, Benjamin R; Greenberg, Bruce M; Slater, Gregory F

2010-04-01

In a petroleum impacted land-farm soil in Sarnia, Ontario, compound-specific natural abundance radiocarbon analysis identified biodegradation by the soil microbial community as a major pathway for hydrocarbon removal in a novel remediation system. During remediation of contaminated soils by a plant growth promoting rhizobacteria enhanced phytoremediation system (PEPS), the measured Delta(14)C of phospholipid fatty acid (PLFA) biomarkers ranged from -793 per thousand to -897 per thousand, directly demonstrating microbial uptake and utilization of petroleum hydrocarbons (Delta(14)C(PHC) = -1000 per thousand). Isotopic mass balance indicated that more than 80% of microbial PLFA carbon was derived from petroleum hydrocarbons (PHC) and a maximum of 20% was obtained from metabolism of more modern carbon sources. These PLFA from the contaminated soils were the most (14)C-depleted biomarkers ever measured for an in situ environmental system, and this study demonstrated that the microbial community in this soil was subsisting primarily on petroleum hydrocarbons. In contrast, the microbial community in a nearby uncontaminated control soil maintained a more modern Delta(14)C signature than total organic carbon (Delta(14)C(PLFA) = +36 per thousand to -147 per thousand, Delta(14)C(TOC) = -148 per thousand), indicating preferential consumption of the most modern plant-derived fraction of soil organic carbon. Measurements of delta(13)C and Delta(14)C of soil CO(2) additionally demonstrated that mineralization of PHC contributed to soil CO(2) at the contaminated site. The CO(2) in the uncontaminated control soil exhibited substantially more modern Delta(14)C values, and lower soil CO(2) concentrations than the contaminated soils, suggesting increased rates of soil respiration in the contaminated soils. In combination, these results demonstrated that biodegradation in the soil microbial community was a primary pathway of petroleum hydrocarbon removal in the PEPS system. This study

Microbial Substrate Usage Indicated by C-14 Contents of Phospholipid Fatty Acids From Soil Organic Matter

NASA Astrophysics Data System (ADS)

Rethemeyer, J.; Nadeau, M. J.; Grootes, P. M.; Kramer, C.; Gleixner, G.

2004-05-01

Phospholipid fatty acids (PLFA's) are generally associated with viable (bacterial) cell membranes. They are thought to be short-lived under normal soil conditions. We compare the C-14 levels in PLFA's obtained from soil samples from the,clean" experimental site at Rotthalmünster (Germany) with those from the agricultural research station at Halle (Germany), where the soil is contaminated with,old" carbon from lignite mining and industry. The most abundant PLFA's were isolated via preparative capillary gas chromatography of their methyl-esters at the Max-Planck Institute, Jena, and their C-14 concentration was determined via accelerator mass spectrometry at the Leibniz-Labor, Kiel. The C-14 levels of three mono-unsaturated fatty acids (n-C17:1, n-C18:1 (and n-C16:1)) are not statistically significant different from those of the contemporaneous atmosphere, indicating these fatty acids were derived from fresh plant material. C-14 levels significantly above those of the atmosphere in three saturated fatty acids (i/a-C15:0, n-C16:0 and cy-C18:0) from the surface soil of Rotthalmünster must derive from carbon fixed from the atmosphere several years earlier, when levels of bomb-C-14, remaining from the atmospheric nuclear weapons tests, especially of the early 1960's, were still higher. Lower C-14 levels in the same compounds from the Halle surface soil indicate the incorporation of "old" contaminant carbon. A below- atmospheric C-14 concentration in n-C18:0 in Rotthalmünster surface soil may reflect the partial incorporation of carbon from older, pre-bomb times. The C-14 concentrations show these PLFA's were synthesized predominantly from recent to sub-recent photosynthetic compounds, while the significant differences in C-14 concentration, observed between the PLFA's, indicate their production from soil organic matter fractions of different (recent) age and C-14 content. The Halle results show "old" carbon may be incorporated into PLFA's and thus reenter the soil

Elimination of Mycoplasma Contamination from Infected Human Hepatocyte C3A Cells by Intraperitoneal Injection in BALB/c Mice.

PubMed

Weng, Jun; Li, Yang; Cai, Lei; Li, Ting; Peng, Gongze; Fu, Chaoyi; Han, Xu; Li, Haiyan; Jiang, Zesheng; Zhang, Zhi; Du, Jiang; Peng, Qing; Gao, Yi

2017-01-01

Background/Aims: The use of antibiotics to eliminate Mycoplasma contamination has some serious limitations. Mycoplasma contamination can be eliminated by intraperitoneal injection of BALB/c mice with contaminated cells combined with screening monoclonal cells. However, in vivo passage in mice after injection with contaminated cells requires a long duration (20-54 days). Furthermore, it is important to monitor for cross-contamination of mouse and human cells, xenotropic murine leukemia virus-related virus (XMRV) infection, and altered cell function after the in vivo treatment. The present study aimed to validate a reliable and simplified method to eliminate mycoplasma contamination from human hepatocytes. BALB/c mice were injected with paraffin oil prior to injection with cells, in order to shorten duration of intraperitoneal passage. Cross-contamination of mouse and human cells, XMRV infection and cell function-related genes and proteins were also evaluated. Methods: PCR and DNA sequencing were used to confirm Mycoplasma hyorhinis ( M. hyorhinis ) contamination in human hepatocyte C3A cells. Five BALB/c mice were intraperitoneally injected with 0.5 ml paraffin oil 1 week before injection of the cells. The mice were then intraperitoneally injected with C3A hepatocytes (5.0 × 10 6 /ml) contaminated with M. hyorhinis (6.2 ± 2.2 × 10 8 CFU/ml). Ascites were collected for monoclonal cell screening on the 14th day after injection of contaminated cells. Elimination of mycoplasma from cells was determined by PCR and Transmission Electron Microscopy (TEM). Human-mouse cell and XMRV contamination were also detected by PCR. Quantitative reverse transcription PCR and western blotting were used to compare the expression of genes and proteins among treated cells, non-treated infected cells, and uninfected cells. Results: Fourteen days after injection with cells, 4 of the 5 mice had ascites. Hepatocyte colonies extracted from the ascites of four mice were all mycoplasma

Assessing open-system behavior of 14C in terrestrial gastropod shells

USGS Publications Warehouse

Rech, Jason A.; Pigati, Jeffrey S.; Lehmann, Sophie B.; McGimpsey, Chelsea N.; Grimley, David A.; Nekola, Jeffrey C.

2011-01-01

In order to assess open-system behavior of radiocarbon in fossil gastropod shells, we measured the 14C activity on 10 aliquots of shell material recovered from Illinoian (~190-130 ka) and pre-Illinoian (~800 ka) loess and lacustrine deposits in the Midwestern USA. Eight of the 10 aliquots yielded measurable 14C activities that ranged from 0.25 to 0.53 percent modern carbon (pMC), corresponding to apparent 14C ages between 48.2 and 42.1 ka. This small level of open-system behavior is common in many materials that are used for 14C dating (e.g. charcoal), and typically sets the upper practical limit of the technique. Two aliquots of gastropod shells from the Illinoian-aged Petersburg Silt (Petersburg Section) in central Illinois, USA, however, yielded elevated 14C activities of 1.26 and 1.71 pMC, which correspond to apparent 14C ages of 35.1 and 32.7 ka. Together, these results suggest that while many fossil gastropods shells may not suffer from major (>1%) open-system problems, this is not always the case. We then examined the mineralogy, trace element chemistry, and physical characteristics of a suite of fossil and modern gastropod shells to identify the source of contamination in the Petersburg shells and assess the effectiveness of these screening techniques at identifying samples suitable for 14C dating. Mineralogical (XRD) and trace element analyses were inconclusive, which suggests that these techniques are not suitable for assessing open-system behavior in terrestrial gastropod shells. Analysis with scanning electron microscopy (SEM), however, identified secondary mineralization (calcium carbonate) primarily within the inner whorls of the Petersburg shells. This indicates that SEM examination, or possibly standard microscope examination, of the interior of gastropod shells should be used when selecting fossil gastropod shells for 14C dating.

C-14/I-29 Preservation and Hold Time Survey

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

Kitchen, S.

2015-04-08

Preservation and hold time of radionuclides must account for both nuclear half-lives and nonnuclear loss mechanisms, but variations in the latter are often neglected. Metals-based defaults are inappropriate for long-lived non-metals C-14 and I-129, which are vulnerable to chemical and biological volatilization. Non-acidification is already widely practiced for them. Recommended addition measures from radiological and chemical literature include glass containers where possible, water filtration where possible, headspace minimization, light shielding, cold (4°C) storage and unfiltered water hold time of 28 days. Soil hold time may need to be shortened when water-logged, excessively sandy, or still adjusting to significant new contamination.

A cross-study analysis of prenatal exposures to environmental contaminants and the epigenome: support for stress-responsive transcription factor occupancy as a mediator of gene-specific CpG methylation patterning

PubMed Central

Martin, Elizabeth M.; Fry, Rebecca C.

2016-01-01

Abstract A biological mechanism by which exposure to environmental contaminants results in gene-specific CpG methylation patterning is currently unknown. We hypothesize that gene-specific CpG methylation is related to environmentally perturbed transcription factor occupancy. To test this hypothesis, a database of 396 genes with altered CpG methylation either in cord blood leukocytes or placental tissue was compiled from 14 studies representing assessments of six environmental contaminants. Subsequently, an in silico approach was used to identify transcription factor binding sites enriched among the genes with altered CpG methylation in relationship to the suite of environmental contaminants. For each study, the sequences of the promoter regions (representing −1000 to +500 bp from the transcription start site) of all genes with altered CpG methylation were analyzed for enrichment of transcription factor binding sites. Binding sites for a total of 56 unique transcription factors were identified to be enriched within the promoter regions of the genes. Binding sites for the Kidney-Enriched Krupple-like Factor 15, a known responder to endogenous stress, were enriched ( P  < 0.001–0.041) among the genes with altered CpG methylation associated for five of the six environmental contaminants. These data support the transcription factor occupancy theory as a potential mechanism underlying environmentally-induced gene-specific CpG methylation. PMID:27066266

Behavior of 14C aflatoxin M1 during camembert cheese making.

PubMed

Fremy, J M; Roiland, J C; Gaymard, A

1990-01-01

Camembert cheeses are made from raw milk spiked with aflatoxin M1. Three aflatoxin M1 levels (7.5 micrograms/L, 3 micrograms/L, and 0.3 micrograms/L) are used. In curds 35.6, 47.1, and 57.7% of aflatoxin M1, respectively, are recovered, and in wheys 64.4, 52.9, and 42.3%, respectively, are recovered. During the first 15 days of storage, the aflatoxin M1 content of different cheeses decreases 25, 55, and 75%, respectively. A similar experiment is made with milk contaminated with 14C labeled aflatoxin M1. The same results are obtained, except for the behavior of aflatoxin M1 in cheese; the same 14C activity is recovered during storage for 30 days.

Synthesis and characterization of 3-ketohexadecanoic acid-1-14-C, DL-3-hydroxyhexadecanoic acid-1-14-C, and trans-2-hexadecenoic acid-1-14-C.

PubMed

Jones, J A; Blecher, M

1966-05-01

The chemical synthesis and characterization of three intermediates in the Beta oxidation of palmitic acid-1-(14)C by rat liver mitochondria, namely, 3-ketohexadecanoic acid-1-(14)C, DL-3-hydroxyhexadecanoic acid-1-(14)C, and trans-2-hexadecenoic acid-1-(14)C, are described.

Impact of off-diagonal cross-shell interaction on 14C

NASA Astrophysics Data System (ADS)

Yuan, Cen-Xi

2017-10-01

A shell-model investigation is performed to show the impact on the structure of 14C from the off-diagonal cross-shell interaction, 〈pp|V|sdsd〉, which represents the mixing between the 0 and 2ħω configurations in the psd model space. The observed levels of the positive states in 14C can be nicely described in 0-4ħω or a larger model space through the well defined Hamiltonians, YSOX and WBP, with a reduction of the strength of the 〈pp|V|sdsd〉 interaction in the latter. The observed B(GT) values for 14C can be generally described by YSOX, while WBP and their modifications of the 〈pp|V|sdsd〉 interaction fail for some values. Further investigation shows the effect of such interactions on the configuration mixing and occupancy. The present work shows examples of how the off-diagonal cross-shell interaction strongly drives the nuclear structure. Supported by National Natural Science Foundation of China (11305272), Special Program for Applied Research on Super Computation of the NSFC Guangdong Joint Fund (the second phase), the Guangdong Natural Science Foundation (2014A030313217), the Pearl River S&T Nova Program of Guangzhou (201506010060), the Tip-top Scientific and Technical Innovative Youth Talents of Guangdong special support program (2016TQ03N575), and the Fundamental Research Funds for the Central Universities (17lgzd34)

14 CFR 1253.550 - Sex as a bona fide occupational qualification.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Sex as a bona fide occupational... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 1253.550 Sex as...

14 CFR 1253.550 - Sex as a bona fide occupational qualification.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Sex as a bona fide occupational... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 1253.550 Sex as...

14 CFR 1253.550 - Sex as a bona fide occupational qualification.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Sex as a bona fide occupational... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 1253.550 Sex as...

14 CFR 1253.550 - Sex as a bona fide occupational qualification.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Sex as a bona fide occupational... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 1253.550 Sex as...

Assessing open-system behavior of 14C in terrestrial gastropod shells

USGS Publications Warehouse

Rech, J.A.; Pigati, J.S.; Lehmann, S.B.; McGimpsey, C.N.; Grimley, D.A.; Nekola, J.C.

2011-01-01

In order to assess open-system behavior of radiocarbon in fossil gastropod shells, we measured the 14C activity on 10 aliquots of shell material recovered from Illinoian (~190-130 ka) and pre-Illinoian (~800 ka) loess and lacustrine deposits in the Midwestern USA. Eight of the 10 aliquots yielded measurable 14C activities that ranged from 0.25 to 0.53 percent modern carbon (pMC), corresponding to apparent 14C ages between 48.2 and 42.1 ka. This small level of open-system behavior is common in many materials that are used for 14C dating (e.g. charcoal), and typically sets the upper practical limit of the technique. Two aliquots of gastropod shells from the Illinoian-aged Petersburg Silt (Petersburg Section) in central Illinois, USA, however, yielded elevated 14C activities of 1.26 and 1.71 pMC, which correspond to apparent 14C ages of 35.1 and 32.7 ka. Together, these results suggest that while many fossil gastropods shells may not suffer from major (>1%) open-system problems, this is not always the case. We then examined the mineralogy, trace element chemistry, and physical characteristics of a suite of fossil and modern gastropod shells to identify the source of contamination in the Petersburg shells and assess the effectiveness of these screening techniques at identifying samples suitable for 14C dating. Mineralogical (XRD) and trace element analyses were inconclusive, which suggests that these techniques are not suitable for assessing open-system behavior in terrestrial gastropod shells. Analysis with scanning electron microscopy (SEM), however, identified secondary mineralization (calcium carbonate) primarily within the inner whorls of the Petersburg shells. This indicates that SEM examination, or possibly standard microscope examination, of the interior of gastropod shells should be used when selecting fossil gastropod shells for 14C dating. ?? 2011 by the Arizona Board of Regents on behalf of the University of Arizona.

Development of a nanofiltration method for bone collagen 14C AMS dating

NASA Astrophysics Data System (ADS)

Boudin, Mathieu; Boeckx, Pascal; Buekenhoudt, Anita; Vandenabeele, Peter; Van Strydonck, Mark

2013-01-01

Radiocarbon dating of bones is usually performed on the collagen fraction. However, this collagen can contain exogenous molecules, including humic substances (HSs) and/or other soil components that may have a different age than the bone. Incomplete removal can result in biased 14C dates. Ultrafiltration of collagen, dissolved as gelatin (molecular weight (MW) ∼100,000 Dalton), has received considerable attention to obtain more reliable dates. Ultrafiltration is an effective method of removal of low-molecular weight contaminants from bone collagen but it does not remove high-molecular weight contaminants, such as cross-linked humic collagen complexes. However, comparative dating studies have raised the question whether this cleaning step itself may introduce contamination with carbon from the filters used. In this study, a nanofiltration method was developed using a ceramic filter to avoid a possible extraneous carbon contamination introduced by the filter. This method should be applicable to various protein materials e.g. collagen, silk, wool, leather and should be able to remove low-molecular and high molecular weight HSs. In this study bone collagen was hot acid hydrolyzed to amino acids and nanofiltrated. A filter with a molecular weight cutoff (MWCO) of 450 Dalton was chosen in order to collect the amino acids in the permeate and the HSs in the retentate. Two pilot studies were set up. Two nanofiltration types were tested in pilot study 1: dead end and cross flow filtration. Humic substance (HS)-solutions with fossil carbon and modern hydrolyzed collagen contaminated with HSs were filtrated and analyzed with spectrofluorescence to determine the HS removal. Cross flow nanofiltration showed the most efficient HS removal. A second pilot study based upon these results was set up wherein only cross flow filtration was performed. 14C measurements of the permeates of hydrolyzed modern collagen contaminated with fossil HSs demonstrate a significant but incomplete

Do site-specific radiocarbon measurements reflect localized distributions of 14C in biota inhabiting a wetland with point contamination sources?

PubMed

Yankovich, T; King-Sharp, K J; Benz, M L; Carr, J; Killey, R W D; Beresford, N A; Wood, M D

2013-12-01

Duke Swamp is a wetland ecosystem that receives (14)C via a groundwater pathway originating from a waste management area on Atomic Energy Canada Limited's Chalk River Laboratories site. This groundwater reaches the surface of the swamp, resulting in relatively high (14)C levels over an area of 146 m(2). The objective of this study was to quantify (14)C concentrations in flora and fauna inhabiting areas of Duke Swamp over the gradient of (14)C activity concentrations in moss to determine whether (14)C specific activities in receptor biota reflect the localized nature of the groundwater source in the swamp. Representative receptor plants and animals, and corresponding air and soil samples were collected at six sites in Duke Swamp with (14)C specific activities in air that ranged from 1140 to 45,900 Bq/kg C. In general, it was found that specific activities of (14)C in biota tissues reflected those measured in environmental media collected from the same sampling site. The findings demonstrate that mosses could be used in monitoring programs to ensure protection of biota in areas with elevated (14)C, negating the need to capture and euthanize higher organisms. Copyright © 2013 Elsevier Ltd. All rights reserved.

Jewelry boxes contaminated by Aspergillus oryzae: an occupational health risk?

PubMed

Bellanger, Anne-Pauline; Roussel, Anaïs; Millon, Laurence; Delaforge, Marcel; Reboux, Gabriel

2012-01-01

In 2009, 100,000 jewelry boxes, manufactured in China, were delivered to a jewelry manufacturer in Besançon, France. All the boxes were contaminated by mold. Because the workers refused to handle these jewelry boxes, the company contacted our laboratory to determine how to deal with the problem. Three choices were available: (1) decontaminate the boxes, (2) return the boxes to the Chinese manufacturer, or (3) destroy the entire shipment. Based on microscopic identification, the culture analysis was positive for A. oryzae. This could not be confirmed by molecular techniques because of the genetic proximity of A. oryzae and A. flavus. Because A. flavus can produce aflatoxins, we tested for them using mass spectrometry. Aflatoxins B1, B2, G1, G2, and M1 were not detected; however, given the specifics of this situation, we could not discard the possibility of the presence of other aflatoxins, such as P1, B3, GM2, and ethoxyaflatoxin B2. We concluded that the contamination by A. oryzae was probably due to food products. However, because of the possible presence of aflatoxins, occupational health risks could not be entirely ruled out. The decision was therefore taken to destroy all the jewelry boxes by incineration. To avoid a similar situation we propose: (1) to maintain conditions limiting mold contamination during production (not eating on the work site, efficient ventilation systems); (2) to desiccate the products before sending them; and (3) to closely control the levels of dampness during storage and transport.

14 CFR § 1253.550 - Sex as a bona fide occupational qualification.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Sex as a bona fide occupational... ADMINISTRATION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities...

Indigenous 14C-phenanthrene biodegradation in "pristine" woodland and grassland soils from Norway and the United Kingdom.

PubMed

Okere, Uchechukwu V; Schuster, Jasmin K; Ogbonnaya, Uchenna O; Jones, Kevin C; Semple, Kirk T

2017-11-15

In this study, the indigenous microbial mineralisation of 14 C-phenanthrene in seven background soils (four from Norwegian woodland and three from the UK (two grasslands and one woodland)) was investigated. ∑PAHs ranged from 16.39 to 285.54 ng g -1 dw soil. Lag phases (time before 14 C-phenanthrene mineralisation reached 5%) were longer in all of the Norwegian soils and correlated positively with TOC, but negatively with ∑PAHs and phenanthrene degraders for all soils. 14 C-phenanthrene mineralisation in the soils varied due to physicochemical properties. The results show that indigenous microorganisms can adapt to 14 C-phenanthrene mineralisation following diffuse PAH contamination. Considering the potential of soil as a secondary PAH source, these findings highlight the important role of indigenous microflora in the processing of PAHs in the environment.

Abiotic and bioaugmented granular activated carbon for the treatment of 1,4-dioxane-contaminated water.

PubMed

Myers, Michelle A; Johnson, Nicholas W; Marin, Erick Zerecero; Pornwongthong, Peerapong; Liu, Yun; Gedalanga, Phillip B; Mahendra, Shaily

2018-06-04

1,4-Dioxane is a probable human carcinogen and an emerging contaminant that has been detected in surface water and groundwater resources. Many conventional water treatment technologies are not effective for the removal of 1,4-dioxane due to its high water solubility and chemical stability. Biological degradation is a potentially low-cost, energy-efficient approach to treat 1,4-dioxane-contaminated waters. Two bacterial strains, Pseudonocardia dioxanivorans CB1190 (CB1190) and Mycobacterium austroafricanum JOB5 (JOB5), have been previously demonstrated to break down 1,4-dioxane through metabolic and co-metabolic pathways, respectively. However, both CB1190 and JOB5 have been primarily studied in laboratory planktonic cultures, while most environmental microbes grow in biofilms on surfaces. Another treatment technology, adsorption, has not historically been considered an effective means of removing 1,4-dioxane due to the contaminant's low K oc and K ow values. We report that the granular activated carbon (GAC), Norit 1240, is an adsorbent with high affinity for 1,4-dioxane as well as physical dimensions conducive to attached bacterial growth. In abiotic batch reactor studies, 1,4-dioxane adsorption was reversible to a large extent. By bioaugmenting GAC with 1,4-dioxane-degrading microbes, the adsorption reversibility was minimized while achieving greater 1,4-dioxane removal when compared with abiotic GAC (95-98% reduction of initial 1,4-dioxane as compared to an 85-89% reduction of initial 1,4-dioxane, respectively). Bacterial attachment and viability was visualized using fluorescence microscopy and confirmed by amplification of taxonomic genes by quantitative polymerase chain reaction (qPCR) and an ATP assay. Filtered samples of industrial wastewater and contaminated groundwater were also tested in the bioaugmented GAC reactors. Both CB1190 and JOB5 demonstrated 1,4-dioxane removal greater than that of the abiotic adsorbent controls. This study suggests that

Direct dating of archaeological pottery by compound-specific 14C analysis of preserved lipids.

PubMed

Stott, Andrew W; Berstan, Robert; Evershed, Richard P; Bronk-Ramsey, Christopher; Hedges, Robert E M; Humm, Martin J

2003-10-01

A methodology is described demonstrating the utility of the compound-specific 14C technique as a direct means of dating archaeological pottery. The method uses automated preparative capillary gas chromatography employing wide-bore capillary columns to isolate individual compounds from lipid extracts of archaeological potsherds in high purity (>95%) and amounts (>200 microg) sufficient for radiocarbon dating using accelerator mass spectrometry (AMS). A protocol was developed and tested on n-alkanes and n-carboxylic acids possessing a broad range of 14C ages. Analytical blanks and controls allowed background 14C measurements to be assessed and potential sources of errors to be detected, i.e., contamination with modern or dead 14C, isotopic fraction effects, etc. A "Russian doll" method was developed to transfer isolated target compounds onto tin powder/capsules prior to combustion and AMS analyses. The major advantage of the compound-specific technique is that 14C dates obtained for individual compounds can be directly linked to the commodities processed in the vessels during their use, e.g., animal fats. The compound-specific 14C dating protocol was validated on a suite of ancient pottery whose predicted ages spanned a 5000-year date range. Initial results indicate that meaningful correlations can be obtained between the predicted date of pottery and that of the preserved lipids. These findings constitute an important step forward to the direct dating of archaeological pottery.

Behavior of sup 14 C aflatoxin M1 during camembert cheese making

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

Fremy, J.M.; Roiland, J.C.; Gaymard, A.

Camembert cheeses are made from raw milk spiked with aflatoxin M1. Three aflatoxin M1 levels (7.5 micrograms/L, 3 micrograms/L, and 0.3 micrograms/L) are used. In curds 35.6, 47.1, and 57.7% of aflatoxin M1, respectively, are recovered, and in wheys 64.4, 52.9, and 42.3%, respectively, are recovered. During the first 15 days of storage, the aflatoxin M1 content of different cheeses decreases 25, 55, and 75%, respectively. A similar experiment is made with milk contaminated with {sup 14}C labeled aflatoxin M1. The same results are obtained, except for the behavior of aflatoxin M1 in cheese; the same 14C activity is recoveredmore » during storage for 30 days.« less

Ramped PyrOx 14C With a Twist: Improving Radiocarbon Chronologies on Highly Detrital Marginal Antarctic Sediments

NASA Astrophysics Data System (ADS)

Subt, C.; Yoon, H.; Yoo, K. C.; Lee, J. I.; Domack, E. W.; Rosenheim, B. E.

2016-02-01

Highly detrital sediments can be difficult to date when the detritus includes material similar to that from which dates are sought. For radiocarbon dating, samples with a high degree of pre-aged detrital carbon contamination necessitate measurement of a very small portion of the sample to remove that contamination from the targeted component, even when using advanced techniques such as Ramped PyrOx (RP) 14C dating. Here we present three case studies of alternative RP approaches, producing accurate and precise chronologies for highly detrital sediments near the Larsen C ice shelf, near the Drygalski Ice Tongue in Ross Sea, and in Lapeyrère Bay, Anvers Island. For sediments where the proportion of organic carbon that was modern at the time of deposition is too small for a traditional AMS analysis after RP treatment, we have developed an innovative multiple RP analyses approach to minimize the cost in precision from using smaller temperature intervals, while maximizing the benefit in accuracy. Resulting sub ice-shelf chronologies show vastly improved dates down-core, significantly younger than the equivalent 14C chronology from the bulk acid insoluble organic (AIO) carbon with increasing ages down-core. By comparison, bulk AIO 14C dates in the study areas are not only older, but are subject to age reversals and nearly constant ages that make sedimentation rates impossible to resolve. Using our new approaches, we can reduce pre-aged carbon contamination in Lapeyrère Bay, and date sediments within layers of siliceous mud and ooze in the Ross Sea, and near the Larsen C ice shelf. Improved accuracy for 14C dates of highly detrital sediments can sometimes require the incorporation of a larger blank correction to account for multiple analyses, decreasing the precision. Application of this method refines ages of hard-to-date sediments, removing limits on what to include in a regional approach to chronicle ice shelf collapse.

Activated Persulfate Treatment of 1,4-Dioxane in the Presence of Chlorinated Solvent Co-contaminants

NASA Astrophysics Data System (ADS)

Boving, T. T.; Eberle, D. E. H.; Ball, R.

2014-12-01

1,4-dioxane is an emerging groundwater contaminant and a likely human carcinogen. Due to its history as a stabilizer in chlorinated solvents, 1,4-dioxane is often found as a co-contaminant at solvent releases sites such as landfills, solvent recycling facilities, vapor decreasing operations, and fire-training areas. Historically, 1,4-dioxane was not routinely analyzed for at solvent release sites. The lack of analyses and the limitations of the analyses that were performed (i.e. high reporting limits) means that the scale of 1,4-dioxane subsurface contamination is still emerging. With the number of known 1,4-dioxane sites increasing, the need for cost effective 1,4-dioxane remediation technologies is rising as well. Remediation strategies that are capable of treating both 1,4-dioxane as well as chlorinated co-contaminants are of particular importance, especially when treating mixed-waste source zones. In the present study, we examined the fate of 1,4-dioxane during the targeted remediation of aqueous phase volatile organic compounds (VOC) using an activated persulfate based ISCO method (OxyZone®). Bench scale laboratory experiments are used to evaluate the treatability of 1,4-dioxane both as a single compound and in the presence of trichloroethene (TCE) and 1,1,1-trichloroethane (1,1,1-TCA). Possible dependencies on oxidant concentration and reaction kinetics were studied. Preliminary results are promising and show that OxyZone® is persistent and long lived, with oxidation of 1,4-dioxane continuing more than 12 days after initial dosage, even at dilute oxidant concentrations. The oxidative destruction of 1,4-dioxane, TCE and 1,1,1-TCA in single compound batch systems followed pseudo first order reaction kinetics. The rate of oxidation for each contaminant increased linearly with increasing persulfate concentration over the range of oxidant concentrations tested. The rate of oxidative destruction, from most easily degraded to least was: TCE > 1,4-Dioxane > 1

1,4-Dioxane drinking water occurrence data from the third unregulated contaminant monitoring rule.

PubMed

Adamson, David T; Piña, Elizabeth A; Cartwright, Abigail E; Rauch, Sharon R; Hunter Anderson, R; Mohr, Thomas; Connor, John A

2017-10-15

This study examined data collected from U.S. public drinking water supplies in support of the recently-completed third round of the Unregulated Contaminant Monitoring Rule (UCMR3) to better understand the nature and occurrence of 1,4-dioxane and the basis for establishing drinking water standards. The purpose was to evaluate whether the occurrence data for this emerging but federally-unregulated contaminant fit with common conceptual models, including its persistence and the importance of groundwater contamination for potential exposure. 1,4-Dioxane was detected in samples from 21% of 4864 PWSs, and was in exceedance of the health-based reference concentration (0.35μg/L) at 6.9% of these systems. In both measures, it ranked second among the 28 UCMR3 contaminants. Although much of the focus on 1,4-dioxane has been its role as a groundwater contaminant, the detection frequency for 1,4-dioxane in surface water was only marginally lower than in groundwater (by a factor of 1.25; p<0.0001). However, groundwater concentrations were higher than those in surface water (p<0.0001) and contributed to a higher frequency of exceeding the reference concentration (by a factor of 1.8, p<0.0001), indicating that surface water sources tend to be more dilute. Sampling from large systems increased the likelihood that 1,4-dioxane was detected by a factor of 2.18 times relative to small systems (p<0.0001). 1,4-Dioxane detections in drinking water were highly associated with detections of other chlorinated compounds particularly 1,1-dichlorethane (odds ratio=47; p<0.0001), which is associated with the release of 1,4-dioxane as a chlorinated solvent stabilizer. Based on aggregated nationwide data, 1,4-dioxane showed evidence of a decreasing trend in concentration and detection frequency over time. These data suggest that the loading to drinking water supplies may be decreasing. However, in the interim, some water supply systems may need to consider improving their treatment capabilities

Transport of sup 14 C-IAA and sup 14 C-ACC within floral organs of Ipomoea nil

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

Kiss, H.G.; Maurice, H.R.; Koning, R.E.

1989-04-01

The transport of {sup 14}C-IAA {sup 14}C-ACC from agarose donor blocks applied to I. nil filaments their recovery as {sup 14}C-accumulation into floral organs was examined. The accumulation of the isotopes in the corolla tissue was greater when {sup 14}C-ACC was applied than {sup 14}C-IAA in intact isolated flower buds. Greater levels of the isotopes accumulated in the pistil, with minimal levels in receptacle and calyx tissues from isolated buds. With intact buds, greater levels of the isotopes were recovered in pistil, calyx receptacle tissues. This study provides further evidence for the role of the filaments as transport vectors formore » IAA ACC for the production of ethylene.« less

Analysis of 14C-bearing compounds released by the corrosion of irradiated steel using accelerator mass spectrometry.

PubMed

Cvetković, B Z; Salazar, G; Kunz, D; Szidat, S; Wieland, E

2018-06-25

The combination of ion chromatography (IC) with accelerator mass spectrometry (AMS) was developed to determine the speciation of 14C-(radiocarbon) bearing organic compounds in the femto to pico molar concentration range. The development of this compound-specific radiocarbon analysis (CSRA) of carboxylic acids is reported and the application of the method on a leaching solution from neutron-irradiated steel is demonstrated. The background and the dynamic range of the AMS-based method were quantified. On using 14C-labelled standards, the measurements demonstrate the repeatability of the analytical method and the reproducible recovery of the main target carboxylic acids (i.e., acetate, formate, malonate, and oxalate). The detection limit was determined to be in the mid fmol 14C per L level while the dynamic range of the analytical method covers three orders of magnitude from the low fmol to the mid pmol 14C per L level. Cross contamination was found to be negligible during IC fractionation and was accounted for during eluate processing and 14C detection by AMS. The 14C-bearing carboxylates released from an irradiated steel nut into an alkaline leaching solution were analysed using the CSRA-based analytical method with the aim to check the applicability of the approach and develop appropriate sample preparation. The concentrations of 14C-bearing formate and acetate, the main organic corrosion products, were at a low pmol 14C per L level for convenient dimensions of the alkaline leaching experiment which demonstrates that compound-specific 14C AMS is an extremely sensitive analytical method for analysing 14C-bearing compounds. The content of total organic 14C in solution (TO14C) determined by the direct measurement of an aliquot of the leaching solution agrees well with the sum of the 14C concentrations of the individual carboxylates within the uncertainty of the data. Furthermore, the TO14C content is in good agreement with the calculated value using the corrosion rate

Assessment of Environmental Contamination with Pathogenic Bacteria at a Hospital Laundry Facility.

PubMed

Michael, Karen E; No, David; Daniell, William E; Seixas, Noah S; Roberts, Marilyn C

2017-11-10

Little is known about exposure to pathogenic bacteria among industrial laundry workers who work with soiled clinical linen. To study worker exposures, an assessment of surface contamination was performed at an industrial laundry facility serving hospitals in Seattle, WA, USA. Surface swab samples (n = 240) from the environment were collected during four site visits at 3-month intervals. These samples were cultured for Clostridium difficile, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE). Voluntary participation of 23 employees consisted of nasal swabs for detection of MRSA, observations during work, and questionnaires. Contamination with all three pathogens was observed in both dirty (laundry handling prior to washing) and clean areas (subsequent to washing). The dirty area had higher odds of overall contamination (≥1 pathogen) than the clean area (odds ratio, OR = 18.0, 95% confidence interval 8.9-36.5, P < 0.001). The odds of contamination were high for each individual pathogen: C. difficile, OR = 15.5; MRSA, OR = 14.8; and VRE, OR = 12.6 (each, P < 0.001). The highest odds of finding surface contamination occurred in the primary and secondary sort areas where soiled linens were manually sorted by employees (OR = 63.0, P < 0.001). The study substantiates that the laundry facility environment can become contaminated by soiled linens. Workers who handle soiled linen may have a higher risk of exposure to C. difficile, MRSA, and VRE than those who handle clean linens. Improved protocols for prevention and reduction of environmental contamination were implemented because of this study. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Biomineralization of 1,4-dioxane in Pure Culture, Microcosm, and Column Studies Using 13C Labeling

NASA Astrophysics Data System (ADS)

Rolston, H. M.; Azizian, M.; Hyman, M. R.; Semprini, L.

2016-12-01

1,4-dioxane (1,4-D), a probable human carcinogen at low (< 1ppb) concentrations, is a widely occurring groundwater contaminant due to its use as a stabilizer for chlorinated solvents. Aerobic cometabolism, the use of a primary substrate to induce the production of microbial enzymes capable of transforming contaminants into innocuous products, is a promising in-situ treatment strategy for 1,4-D because it has the potential to mineralize trace 1,4-D concentrations to carbon dioxide (CO2). Previous work has confirmed the bacterium Rhodococcus rhodochrous (strain ATCC 21198) will transform 1,4-D when grown on isobutane. In this study, 13C uniformly labeled 1,4-D was used to determine the extent to which strain ATCC 21198 biomineralizes 1,4-D to CO2. Batch experiments have been conducted with pure culture 21198 and in microcosms constructed with aquifer sediments. The rate of resting cell transformation of 1,4-D by ATCC 21198 was over 100 times faster than the rate of CO2 accumulation, indicating the presence of intermediates that were slowly mineralized to CO2 . In microcosms, the use of isobutane as a primary substrate effectively stimulated the native microbial community to transform 1,4-D. Microcosms were also bioaugmented with ATCC 21198. After an initial lag and subsequent additions of isobutane, transformation rates in the native microcosms approached those of the bioaugmented microcosms. Cometabolically active microbes survived several periods of starvation in all microcosms, and nutrient amendment allowed for sustained transformation rates. 13C labeled 1,4-D is currently being used to determine the rates and extents of biomineralization in the microcosms. Column studies are also being conducted to evaluate cometabolism and biominerazation potential of isobutane as a biostimulant and 21198 for bioaugmentation under geochemical and flow conditions more representative of in-situ bioremediation.

24 CFR 35.1345 - Occupant protection and worksite preparation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1345 Occupant... occupants and the environment from contamination from lead-contaminated or lead-containing materials during...

24 CFR 35.1345 - Occupant protection and worksite preparation.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1345 Occupant... occupants and the environment from contamination from lead-contaminated or lead-containing materials during...

24 CFR 35.1345 - Occupant protection and worksite preparation.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1345 Occupant... occupants and the environment from contamination from lead-contaminated or lead-containing materials during...

24 CFR 35.1345 - Occupant protection and worksite preparation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1345 Occupant... occupants and the environment from contamination from lead-contaminated or lead-containing materials during...

24 CFR 35.1345 - Occupant protection and worksite preparation.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1345 Occupant... occupants and the environment from contamination from lead-contaminated or lead-containing materials during...

Coprecipitation of (14)C and Sr with carbonate precipitates: The importance of reaction kinetics and recrystallization pathways.

PubMed

Hodkin, David J; Stewart, Douglas I; Graham, James T; Burke, Ian T

2016-08-15

This study investigated the simultaneous removal of Sr(2+) and (14)CO3(2-) from pH>12 Ca(OH)2 solution by the precipitation of calcium carbonate. Initial Ca(2+):CO3(2-) ratios ranged from 10:1 to 10:100 (mM:mM). Maximum removal of (14)C and Sr(2+) both occurred in the system containing 10mM Ca(2+) and 1mM CO3(2-) (99.7% and 98.6% removal respectively). A kinetic model is provided that describes (14)C and Sr removal in terms of mineral dissolution and precipitation reactions. The removal of (14)C was achieved during the depletion of the initial TIC in solution, and was subsequently significantly affected by recrystallization of the calcite precipitate from an elongate to isotropic morphology. This liberated >46% of the (14)C back to solution. Sr(2+) removal occurred as Ca(2+) became depleted in solution and was not significantly affected by the recrystallization process. The proposed reaction could form the basis for low cost remediation scheme for (90)Sr and (14)C in radioactively contaminated waters (<$0.25 reagent cost per m(3) treated). Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Fate of 14C-terpolymer (methylmethacrylate-14C, 2-hydroxyethylmethacrylate, butylacrylate) nanoparticles after peroral administration to rats.

PubMed

Kukan, M; Bezek, S; Koprda, V; Labský, J; Kálal, J; Bauerová, K; Trnovec, T

1989-05-01

The fate of 14C-terpolymer (methylmethacrylate-14C, 2-hydroxyethylmethacrylate, butylacrylate) nanoparticles was studied in male Wistar rats after peroral administration. These nanoparticles may reach systemic circulation as evidenced by the plasma 14C level, excretion of the label in the urine, as well as organ label deposition. It was found that at least 2% of the dose of 14C was absorbed from the gastrointestinal tract. As expected, the radioactive nanoparticles were excreted predominantly via the feces. The amount of the label in the gastrointestinal tract, liver, and carcasses fell below the limit of detection on day seven after administration. However in the spleen and lung some slight radioactivity persisted after 7 d of experiment.

Incorporation of sup 14 C from ( sup 14 C)phenylalanine into condensed tannin of sorghum grain

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

Reddy, V.; Butler, L.G.

A procedure is described for obtaining condensed tannin from sorghum (Sorghum bicolor (L.) Moench) seeds metabolically labeled from ({sup 14}C)phenylalanine. The ({sup 14}C)tannin should be useful in determining the metabolic fate of dietary condensed tannin.

Atmospheric 14 C CO 2 variations in Japan during 1982--1999 based on 14 C measurements of rice grains.

PubMed

Shibata, Setsuko; Kawano, Eiko; Nakabayashi, Takeshige

2005-08-01

(14)C in rice grains is a useful tracer of atmospheric (14)C(CO(2)). (14)C measurement in rice grains for 17 years during 1982--1999 reveals the following. There is negative correlation between Delta(14)C and the population densities of localities in Japan. Under-populated areas in the northern area of Japan and Okinawa remained clean in the 1990s. The (14)C(CO(2)) decline rates at those areas are near to that of Shauinsland. A latitudinal effect due to Chinese nuclear tests is observed in 1982. Small Seuss effects is observed at the middle latitudes in East Asia after 1995.

Assessment of 14C AMS dating of phytoliths as a new paleoenvironmental and archaeological tool

NASA Astrophysics Data System (ADS)

Corbineau, R.; Alexandre, A. E.; Santos, G. M.; Reyerson, P. E.

2011-12-01

14C AMS analysis of occluded carbon in phytoliths (phytC) is a promising dating tool for palaeoenvironmental and archaeological studies. In order to assess the accuracy of this method, different tests were recently carried out on large phytolith concentrates of phytC samples extracted from soils and harvested plants, in association with blank samples of SiO2 powder to check the absence of carbon contamination during the treatments. Despite this precaution, 14C values from recent harvested plants were inexplicably old (2 - 8 ka years BP). Nevertheless, we noticed that many chemical extraction protocols that were used did not lead to samples totally free of organic matter. In order to tackle this problem, and as a first step, the efficiency of common extraction protocols from the literature were tested. Samples were analyzed by SEM/EDX in order to assess the purity of the siliceous material following extraction. As a result of these tests, a new extraction protocol combining acid digestion, oxidation and dry ashing to acquire pure samples of phytoliths from harvested plants is proposed. In a second step, modern and well dated archaeological materials (harvested plants grown within a FACE experiment and plant residues from a 17th century French mummy) were analyzed in 14C-AMS. Results should allow either to demonstrate the reliability of 14C-AMS analysis of phytolith occluded carbon as a dating tool or trigger further investigations of possible sources of old occluded carbon in phytoliths if the 14C ages are still older than expected.

Root-Uptake of C-14 Acetic Acid by Various Plants and C-14 Dynamics Surrounding the Experimental Tessera

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

Ogiyama, S.; Takeda, H.; Uchida, S.

Carbon-14 (C-14, t{sub 1/2} = 5.73x10{sup 3} yrs) from radioactive waste is one of the most important radioactive nuclides for environmental assessment in the context of geological disposal, and understanding the transfer of radioactive elements to plants is essential for public health safety. In order to obtain fundamental knowledge, culture experiments using marigold (Tagetes patula L.), tall fescue (Festuca arundinacea S.), paddy rice (Oryza sativa L.), radish (Raphanus sativus L.), and carrot (Daucus carota L.) plants were conducted to examine root-uptake and dynamics of C-14 in the laboratory. The C-14 radioactivity in each plant part (e.g. shoot, root, edible part,more » etc.), medium (e.g. culture solution, sand, etc.), and air was determined. The distribution of C-14 in the plants was visualized using autoradiography. For a comparison, autoradiography was also done using Na-22. Results of the present study indicated that C-14 labeled CO{sub 2} gas was released from the culture solution to the atmosphere. Clear autoradiography images were observed in plants for the shoots and lower roots which were soaked in the culture solution. The upper roots which were not soaked in the culture solution were not clearly imaged. In the radiotracer experiment using Na-22, a clear image was observed for the whole carrot seedling, even including the upper root, on the autoradiography. However, the amounts of C-14 acetic acid absorbed by all the plants through their roots were considered to be very small. Inorganic carbon transformed from C-14 acetic acid would be taken up by plants through the roots, and some fraction of C-14 would be assimilated into the shoots by photosynthesis. (authors)« less

1,4-Dioxane pollution at contaminated groundwater sites in western Germany and its distribution within a TCE plume.

PubMed

Karges, Ursula; Becker, Johannes; Püttmann, Wilhelm

2018-04-01

An effective and sensitive method for the analysis of 1,4-dioxane in water has been available since 2008 (EPA 522). This method is increasingly being applied to investigate the distribution of 1,4-dioxane in the aquatic environment. However, there is a need for more information about the possible occurrence of 1,4-dioxane in groundwater in Europe in general, and in Germany in particular, where virtually no data have been collected so far. The possible contamination of groundwater with 1,4-dioxane is of relevance to Germany because up to 70% of Germany's drinking water is obtained from groundwater and about 17% from river bank filtrate, which contains variable proportions of groundwater. The aim of the present study is to investigate selected and representative groundwater sites in Germany that have suspected occurrences of 1,4-dioxane. Five of the sites are well known for their volatile chlorinated hydrocarbon contamination, two sites have representative landfill leachate characteristics, and one site is negatively impacted by a detergent manufacturing plant. The presence of 1,4-dioxane was observed at each of these sites. Measured maximum concentration values ranged from 0.15μg/L to 152μg/L. An aquifer containing a trichloroethylene (TCE) plume with 1,4-dioxane as a co-contaminant was investigated in more detail. A perfect match was found between the concentrations of 1,4-dioxane and TCE in the vertical and horizontal distribution profiles. The results indicate the necessity for investigating groundwater contamination by 1,4-dioxane at sites with known 1,1,1-trichloroethane (TCA) and TCE contaminations, in landfill leachates, and at sites of detergent production. Copyright © 2017 Elsevier B.V. All rights reserved.

ORIGIN OF PALMITIC ACID CARBON IN PALMITATES FORMED FROM HEXADECANE-1-C14 AND TETRADECANE-1-C14 BY MICROCOCCUS CERIFICANS

PubMed Central

Finnerty, W. R.; Kallio, R. E.

1964-01-01

Finnerty, W. R. (University of Iowa, Iowa City), and R. E. Kallio. Origin of palmitic acid carbon in palmitates formed from hexadecane-1-C14 and tetradecane-1-C14 by Micrococcus cerificans. J. Bacteriol. 87:1261–1265. 1964.—Degradation of the palmitic acid moiety of cetyl palmitate and myristyl palmitate formed from hexadecane-1-C14 and tetradecane-1-C14 by Micrococcus cerificans was carried out. The patterns of C14 labeling in palmitic acid from cetyl palmitate showed that hexadecane is oxidized at the C1 position, and cetyl alcohol and palmitic acid thus formed are directly esterified. Palmitic acid arising from tetradecane and esterified to tetradecanol appeared to have been synthesized by the addition of two carbon atoms to an existing 14-carbon atom skeleton. Considerable mixing of C14 occurred in the C1 and C2 positions of palmitic acid thus synthesized. PMID:14188700

Accessing the application of in situ cosmogenic 14C to surface exposure dating of amorphous SiO2

NASA Astrophysics Data System (ADS)

Cesta, J. M.; Goehring, B. M.; Ward, D. J.

2017-12-01

We assess the feasibility and utility of in situ cosmogenic 14C as a geochronometer for landforms composed of amorphous SiO2 through the comparison of 14C surface exposure ages to independently determined eruption ages on Obsidian Dome, California. Landforms composed of amorphous SiO2 phases are difficult to date by conventional cosmogenic nuclide methods due to several complications that may arise (e.g., inability to remove meteoric contamination). The onset of an increased understanding of production rates and analytical measurement of in situ 14C in SiO2 provides an opportunity to address this limitation. Obsidian Dome is a 600-year-old phreatomagmatic dome of the Mono-Inyo Craters located in Inyo County, California, and consists of vesicular pumice, obsidian, and rhyolite. Exposure ages from eight obsidian and banded pumice and obsidian surface samples range from 3947 ± 678 to 914 ± 134 years, all significantly older than the accepted radiocarbon age of 650-550 years. δ13C values for the samples range between +2.65‰ and +1.34‰ and show a negative correlation with CO2 yield. The `too old' exposure ages coupled with this negative correlation between δ13C and CO2 yield suggests the incorporation of an atmospheric component of 14C. Measurement of 14C concentrations in shielded, subsurface samples will assist in isolating the atmospheric 14C component and aid in correcting the surface exposure ages.

Hepatitis C among healthcare personnel: secondary data analyses of costs and trends for hepatitis C infections with occupational causes.

PubMed

Westermann, Claudia; Dulon, Madeleine; Wendeler, Dana; Nienhaus, Albert

2016-01-01

Hepatitis C infection is a global public health issue. Chronic hepatitis C infection is associated with significant morbidity and mortality. The aim of this study is to describe the costs for occupationally-cased hepatitis C infections based on data from an accident insurance carrier. This study is a secondary analysis based on the Database of a German Institution for Statutory Accident Insurance. The analysis is based on a sample of insured parties whose hepatitis C infections were recorded as occupational diseases between 1996 and 2013. The analysis is based on recognised hepatitis C cases and incorporates records registered between 1 January 2000 and 31 December 2014. Within the study period, the number of reported and recognised hepatitis C cases declined by 73 and 86% respectively. The majority of recognised hepatitis C cases ( n  = 1.121) were female, older than 40 years and were active in a medical nursing profession. In the study period, the costs came to a total of € 87.9 million, of which 60% was attributable to pension payments (€ 51,570,830) and around 15% was attributable to pharmaceutical and medicinal products (€ 12,978,318). Expenses for drugs exhibited heavy increases in 2012 (from around € 500,000-800,000 to € 1.7 million) and 2014 (to € 2.5 million) in particular. Pension payments came to € 1.6 million in 2000 and rose continuously to over € 4 million in 2014. Expenses for occupational rehabilitation accounted for less than 1%. For hepatitis C infections as an occupational disease, a considerable increase in costs has been observed in recent years, while the number of reports has declined heavily. This rise in costs is explained by the increase in pension payments and, since 2012, by a rise in the costs for drugs. The high costs of anti-viral therapies is offset by the potential for considerable treatment benefits. Healing the infection is expected to generate long-term cost savings for statutory accident insurance carriers

Distribution and biomarkers of carbon-14-labeled fullerene C60 ([(14) C(U)]C60 ) in female rats and mice for up to 30 days after intravenous exposure.

PubMed

Sumner, Susan C J; Snyder, Rodney W; Wingard, Christopher; Mortensen, Ninell P; Holland, Nathan A; Shannahan, Jonathan H; Dhungana, Suraj; Pathmasiri, Wimal; Han, Li; Lewin, Anita H; Fennell, Timothy R

2015-12-01

A comprehensive distribution study was conducted in female rats and mice exposed to a suspension of uniformly carbon-14-labeled C60 ([(14) C(U)]C60 ). Rodents were administered [(14) C(U)]C60 (~0.9 mg kg(-1) body weight) or 5% polyvinylpyrrolidone-saline vehicle alone via a single tail vein injection. Tissues were collected at 1 h and 1, 7, 14 and 30 days after administration. A separate group of rodents received five daily injections of suspensions of either [(14) C(U)]C60 or vehicle with tissue collection 14 days post exposure. Radioactivity was detected in over 20 tissues at all time points. The highest concentration of radioactivity in rodents at each time point was in liver, lungs and spleen. Elimination of [(14) C(U)]C60 was < 2% in urine and feces at any 24 h time points. [(14) C(U)]C60 and [(14) C(U)]C60 -retinol were detected in liver of rats and together accounted for ~99% and ~56% of the total recovered at 1 and 30 days postexposure, respectively. The blood radioactivity at 1 h after [(14) C(U)]C60 exposure was fourfold higher in rats than in mice; blood radioactivity was still in circulation at 30 days post [(14) C(U)]C60 exposure in both species (<1%). Levels of oxidative stress markers increased by 5 days after exposure and remained elevated, while levels of inflammation markers initially increased and then returned to control values. The level of cardiovascular marker von Willebrand factor, increased in rats, but remained at control levels in mice. This study demonstrates that [(14) C(U)]C60 is retained in female rodents with little elimination by 30 days after i.v. exposure, and leads to systemic oxidative stress. Copyright © 2015 John Wiley & Sons, Ltd.

Advantages of the rapid HIV-1 test in occupational accidents with potentially contaminated material among health workers.

PubMed

Machado, A A; Martinez, R; Haikal, A A; Rodrigues da Silva, M C

2001-01-01

In occupational accidents involving health professionals handling potentially contaminated material, the decision to start or to continue prophylactic medication against infection by Human Immunodeficiency Virus (HIV) has been based on the ELISA test applied to a blood sample from the source patient. In order to rationalize the prophylactic use of antiretroviral agents, a rapid serologic diagnostic test of HIV infection was tested by the enzymatic immunoabsorption method (SUDS HIV 1+2, MUREX) and compared to conventional ELISA (Abbott HIV-1/ HIV-2 3rd Generation plus EIA). A total of 592 cases of occupational accidents were recorded at the University Hospital of Ribeirão Preto from July 1998 to April 1999. Of these, 109 were simultaneously evaluated by the rapid test and by ELISA HIV. The rapid test was positive in three cases and was confirmed by ELISA and in one the result was inconclusive and later found to be negative by ELISA. In the 106 accidents in which the rapid test was negative no prophylactic medication was instituted, with an estimated reduction in costs of US$ 2,889.35. In addition to this advantage, the good correlation of the rapid test with ELISA, the shorter duration of stress and the absence of exposure of the health worker to the adverse effects of antiretroviral agents suggest the adoption of this test in Programs of Attention to Accidents with Potentially Contaminated Material.

The production of (14C) oxalate during the metabolism of (14C) carbohydrates in isolated rat hepatocytes.

PubMed

Rofe, A M; James, H M; Bais, R; Edwards, J B; Conyers, R A

1980-04-01

Oxalate (14C) was produced during the metabolism of (U-14C) carbohydrates in hepatocytes isolated from normal rats. At 10 mM, the order of oxalate production was fructose > glycerol > xylitol > sorbitol greater than or equal to glucose in the ratio 10 : 4 : 3 : 1 : 1. This difference between oxalate production from fructose and glucose was reflected in their rates of utilisation, glucose being poorly metabolised in hepatocytes from fasted rats. Fructose was rapidly metabolised, producing glucose, lactate and pyruvate as the major metabolites. Glycerol, xylitol and sorbitol were metabolised at half the rate of fructose, the major metabolites being glucose, lactate and glycerophosphate. The marked similarity in the pattern of intermediary metabolites produced by these polyols was not, however, reflected in the rates of oxalate production. Hepatic polyol metabolism resulted in high levels of cytosolic NADH, as indicated by elevated lactate : pyruvate and glycerophosphate : dihydroxyacetone phosphate ratios. The artificial electron acceptor, phenazine methosulphate (PMS) stimulated oxalate production from the polyols, particularly xylitol. In the presence of PMS, the order of oxalate production was fructose greater than or equal to xylitol > glycerol > sorbitol in the ratio 10 : 10 : 6 : 2. The production of glucose, lactate and pyruvate from the polyols was also stimulated by PMS, whereas the general metabolism of fructose, including oxalate production, was little affected. Oxalate (14C) was produced from (1-14C), (2-14C) and (6-14C) but not (3,4-14C) glucose in hepatocytes isolated from non-fasted, pyridoxine-deficient rats. Whilst this labelling pattern is consistent with oxalate being produced by a number of pathways, it is suggested that metabolism via hydroxypyruvate is a major route for oxalate production from various carbohydrates, with perhaps the exception of xylitol, which appears to have an alternative mechanism for oxalate production. The observation that

Aerobic biodegradation potential of subsurface microorganisms from a jet fuel-contaminated aquifer

USGS Publications Warehouse

Aelion, C.M.; Bradley, P.M.

1991-01-01

In 1975, a leak of 83,000 gallons (314,189 liters) of jet fuel (JP-4) contaminated a shallow water-table aquifer near North Charleston, S.C. Laboratory experiments were conducted with contaminated sediments to assess the aerobic biodegradation potential of the in situ microbial community. Sediments were incubated with 14C-labeled organic compounds, and the evolution of 14CO2 was measured over time. Gas chromatographic analyses were used to monitor CO2 production and O2 consumption under aerobic conditions. Results indicated that the microbes from contaminated sediments remained active despite the potentially toxic effects of JP-4. 14CO2 was measured from [14C]glucose respiration in unamended and nitrate-amended samples after 1 day of incubation. Total [14C]glucose metabolism was greater in 1 mM nitrate-amended than in unamended samples because of increased cellular incorporation of 14C label. [14C]benzene and [14C]toluene were not significantly respired after 3 months of incubation. With the addition of 1 mM NO3, CO2 production measured by gas chromatographic analysis increased linearly during 2 months of incubation at a rate of 0.099 ??mol g-1 (dry weight) day-1 while oxygen concentration decreased at a rate of 0.124 ??mol g-1 (dry weight) day-1. With no added nitrate, CO2 production was not different from that in metabolically inhibited control vials. From the examination of selected components of JP-4, the n-alkane hexane appeared to be degraded as opposed to the branched alkanes of similar molecular weight. The results suggest that the in situ microbial community is active despite the JP-4 jet fuel contamination and that biodegradation may be compound specific. Also, the community is strongly nitrogen limited, and nitrogen additions may be required to significantly enhance hydrocarbon biodegradation.

Accelerator mass spectrometry analysis of 14C-oxaliplatin concentrations in biological samples and 14C contents in biological samples and antineoplastic agents

NASA Astrophysics Data System (ADS)

Toyoguchi, Teiko; Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi; Kato, Kazuhiro; Tokanai, Fuyuki

2015-10-01

Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the 14C concentration in 14C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) - AMS system. The calibration curves of 14C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a 14C content of water in three vacuum blood collection tubes and a syringe were measured. 14C was not detected from water in these devices. The mean 14C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of 14C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, 14C contents of the antineoplastic agents were quantitated. 14C contents were different among 10 antineoplastic agents; 14C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

Low-level 14C methane oxidation rate measurements modified for remote field settings

NASA Astrophysics Data System (ADS)

Pack, M. A.; Pohlman, J.; Ruppel, C. D.; Xu, X.

2012-12-01

Aerobic methane oxidation limits atmospheric methane emissions from degraded subsea permafrost and dissociated methane hydrates in high latitude oceans. Methane oxidation rate measurements are a crucial tool for investigating the efficacy of this process, but are logistically challenging when working on small research vessels in remote settings. We modified a low-level 14C-CH4 oxidation rate measurement for use in the Beaufort Sea above hydrate bearing sediments during August 2012. Application of the more common 3H-CH4 rate measurement that uses 106 times more radioactivity was not practical because the R/V Ukpik cannot accommodate a radiation van. The low-level 14C measurement does not require a radiation van, but careful isolation of the 14C-label is essential to avoid contaminating natural abundance 14C measurements. We used 14C-CH4 with a total activity of 1.1 μCi, which is far below the 100 μCi permitting level. In addition, we modified field procedures to simplify and shorten sample processing. The original low-level 14C-CH4 method requires 6 steps in the field: (1) collect water samples in glass serum bottles, (2) inject 14C-CH4 into bottles, (3) incubate for 24 hours, (4) filter to separate the methanotrophic bacterial cells from the aqueous sample, (5) kill the filtrate with sodium hydroxide (NaOH), and (6) purge with nitrogen to remove unused 14C-CH4. Onshore, the 14C-CH4 respired to carbon dioxide or incorporated into cell material by methanotrophic bacteria during incubation is quantified by accelerator mass spectrometry (AMS). We conducted an experiment to test the possibility of storing samples for purging and filtering back onshore (steps 4 and 6). We subjected a series of water samples to steps 1-3 & 5, and preserved with mercuric chloride (HgCl2) instead of NaOH because HgCl2 is less likely to break down cell material during storage. The 14C-content of the carbon dioxide in samples preserved with HgCl2 and stored for up to 2 weeks was stable

The DSS-14 C-band exciter

NASA Technical Reports Server (NTRS)

Rowan, D. R.

1989-01-01

The development and implementation of a C-band exciter for use with the Block IV Receiver-Exciter Subsystem at Deep Space Station 14 (DSS-14) has been completed. The exciter supplements the standard capabilities of the Block IV system by providing a drive signal for the C-band transmitter while generating coherent translation frequencies for C-band (5-GHz) to S-band (2.2- to 2.3-GHz) Doppler extraction, C-band to L-band (1.6-GHz) zero delay measurements, and a level calibrated L-band test signal. Exciter functions are described, and a general explanation and description of the C-band uplink controller is presented.

Technique for Simultaneous Determination of [35S]Sulfide and [14C]Carbon Dioxide in Anaerobic Aqueous Samples †

PubMed Central

Taylor, Craig D.; Ljungdahl, Per O.; Molongoski, John J.

1981-01-01

A technique for the simultaneous determination of [35S]sulfide and [14C]carbon dioxide produced in anaerobic aqueous samples dual-labeled with [35S]sulfate and a 14C-organic substrate is described. The method involves the passive distillation of sulfide and carbon dioxide from an acidified water sample and their subsequent separation by selective chemical absorption. The recovery of sulfide was 93% for amounts ranging from 0.35 to 50 μmol; recovery of carbon dioxide was 99% in amounts up to 20 μmol. Within these delineated ranges of total sulfide and carbon dioxide, 1 nmol of [35S]sulfide and 7.5 nmol of [14C]carbon dioxide were separated and quantified. Correction factors were formulated for low levels of radioisotopic cross-contamination by sulfide, carbon dioxide, and volatile organic acids. The overall standard error of the method was ±4% for sulfide and ±6% for carbon dioxide. PMID:16345742

AixMICADAS, the accelerator mass spectrometer dedicated to 14C recently installed in Aix-en-Provence, France

NASA Astrophysics Data System (ADS)

Bard, Edouard; Tuna, Thibaut; Fagault, Yoann; Bonvalot, Lise; Wacker, Lukas; Fahrni, Simon; Synal, Hans-Arno

2015-10-01

A compact AMS system dedicated to measuring 14C in ultra-small samples was installed at the CEREGE in Aix-en-Provence at the end of March 2014, together with an automated graphitization system. AixMICADAS operates at around 200 kV with carbon ion stripping in helium leading to a transmission of about 47%. The hybrid ion source works with graphite targets and CO2 gas. It is coupled to a versatile gas interface system that ensures stable gas measurements from different sources: a cracker for CO2 in glass ampoules, an elemental analyzer for combusting organic matter and an automated system to handle carbonate by wet chemistry. The analyses performed during the first half-year of operation show that a precision of about 2‰ is reached on modern samples of about 1 mg of carbon. Measurements of IAEA reference materials of various 14C ages show a good agreement with consensus values. Direct measurements of geological graphites indicate a machine background equivalent to an age of 68,000 years BP. AixMICADAS is thus limited solely by the 14C contamination of samples in the field and in the laboratory. The performances of the gas ion source and its gas interface system were tested with two CO2 production units: the elemental analyzer and the automated carbonate hydrolysis unit. These tests show that samples ranging between 10 and 100 μg C can produce a 12C- ion beam of the order of 10-15 μA during time spans ranging from 3 to 30 min depending on the sample mass. Coupling the automated hydrolysis system to the gas ion source of AixMICADAS, enables us to develop a method involving sequential leaching of carbonate samples with direct 14C measurements of the leached fractions and the residual sample. The main advantage is that all of steps leaching and hydrolysis are performed in the same vial for a particular sample. A sequential leaching was applied to a young carbonate sample (ca. 6600 years BP) whose 14C age agrees with previous determination and which shows no sign of

Hanford Tanks 241-C-203 and 241-C-204: Residual Waste Contaminant Release Model and Supporting Data

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

Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.

This report describes the development of release models for key contaminants that are present in residual sludge remaining after closure of Hanford Tanks 241-C-203 (C-203) and 241-C-204 (C-204). The release models were developed from data generated by laboratory characterization and testing of samples from these two tanks. Key results from this work are (1) future releases from the tanks of the primary contaminants of concern (99Tc and 238U) can be represented by relatively simple solubility relationships between infiltrating water and solid phases containing the contaminants; and (2) high percentages of technetium-99 in the sludges (20 wt% in C-203 and 75more » wt% in C-204) are not readily water leachable, and, in fact, are very recalcitrant. This is similar to results found in related studies of sludges from Tank AY-102. These release models are being developed to support the tank closure risk assessments performed by CH2M HILL Hanford Group, Inc., for the U.S. Department of Energy.« less

Household Contamination with Salmonella enterica1

PubMed Central

Hancock, Dale D.; Roozen, Paivi M.; Szymanski, Maryanne H.; Scheenstra, Beth C.; Cady, Kirsten M.; Besser, Thomas E.; Chudek, Paul A.

2003-01-01

Household contamination with Salmonella enterica increases when occupational exposure exists (cattle farms with known salmonellosis in cattle, a salmonella research laboratory, or a veterinary clinic experiencing an outbreak of salmonellosis). Fifteen of 55 (27.2%) vacuum cleaner bags from households with occupational exposure to S. enterica were positive versus 1 of 24 (4.2% without known exposure. Use of a carpet cleaner and several cleaners/disinfectants reduced, but failed to eliminate, S. enterica from artificially contaminated carpet. PMID:12533294

7Li(15N, 14C)8Be reaction at 81 MeV and 14C + 8Be interaction versus that of 13C + 8Be

NASA Astrophysics Data System (ADS)

Rudchik, A. T.; Rudchik, A. A.; Muravynets, L. M.; Kemper, K. W.; Rusek, K.; Koshchy, E. I.; Piasecki, E.; Trzcinska, A.; Pirnak, Val. M.; Ponkratenko, O. A.; Strojek, I.; Stolarz, A.; Plujko, V. A.; Sakuta, S. B.; Siudak, R.; Ilyin, A. P.; Stepanenko, Yu. M.; Shyrma, Yu. O.; Uleshchenko, V. V.

2018-03-01

Angular distributions of the 7Li(15N, 14C)8Be reaction were measured at the energy Elab(15N) = 81 MeV. Data for transfer to the ground and first two excited states in 8Be were acquired as well as to the 14C ground and excited states. The reaction data were analyzed within the coupled-reaction-channels (CRC) method. The required 15N + 7Li entrance channel potential was taken from the 15N + 7Li elastic scattering. The 14C + 8Be potential was found by fitting Woods-Saxon form potentials to those generated by double folded real and imaginary potentials in the region of interaction. These generated potentials were then used in the CRC calculations. Proton transfer dominants this reaction, including to the excited states of 8Be. The reaction dependence on the exit channel potential was examined by using the 13C + 8Be potential previously deduced from the 9Be(12C, 13C)8Be reaction and 14C + 8Be from the 13C(9Be, 8Be)14C reaction.

Disposition of /sup 14/C-acetohydroxamic acid and /sup 14/C-acetamide in the rat

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

Putcha, L.; Griffith, D.P.; Feldman, S.

Acetohydroxamic acid (AHA) has been identified as a potential agent for the treatment of infection-induced staghorn renal calculi in patients. The pharmacokinetics and disposition of /sup 14/C-acetamide have been evaluated in rats following iv and oral administration. The results of these experiments suggest that, following oral administration to rats, AHA is absorbed very rapidly from the gastrointestinal tract and is metabolized to acetamide and CO/sub 2/. Approximately 50-56% of the iv dose and 40-49% of the oral dose of /sup 14/C-AHA is excreted in the urine, suggesting a significant nonrenal elimination pathway for AHA and metabolite(s). Administration of /sup 14/C-acetamidemore » to rats revealed that the compound is predominantly eliminated via the renal route, accounting for 68% of the administered radioactive dose. However, approximately 30% of the dose in the case of both AHA and acetamide could not be recovered, either in the urine or in the breath, during the 72-hr period of the experiment. This suggests that acetamide, may undergo further metabolism to get incorporated into the acetate pool. This would result in very slow elimination of the remaining activity as /sup 14/CO/sub 2/ or as another unknown metabolite.« less

Draft genome sequence of Mycobacterium rufum JS14(T), a polycyclic-aromatic-hydrocarbon-degrading bacterium from petroleum-contaminated soil in Hawaii.

PubMed

Kwak, Yunyoung; Li, Qing X; Shin, Jae-Ho

2016-01-01

Mycobacterium rufum JS14(T) (=ATCC BAA-1377(T), CIP 109273(T), JCM 16372(T), DSM 45406(T)), a type strain of the species Mycobacterium rufum sp. . belonging to the family Mycobacteriaceae, was isolated from polycyclic aromatic hydrocarbon (PAH)-contaminated soil in Hilo (HI, USA) because it harbors the capability of degrading PAH. Here, we describe the first genome sequence of strain JS14(T), with brief phenotypic characteristics. The genome is composed of 6,176,413 bp with 69.25 % G + C content and contains 5810 protein-coding genes with 54 RNA genes. The genome information on M. rufum JS14(T) will provide a better understanding of the complexity of bacterial catabolic pathways for degradation of specific chemicals.

Preparation of 14C-Labeled Sterigmatocystin in Liquid Media

PubMed Central

Hsieh, Dennis P. H.; Yang, Susie L.

1975-01-01

14C-labeled sterigmatocystin was prepared from surface cultures of Aspergillus versicolor A-18074 maintained in liquid media by multiple additions of [1-14C]acetate to the cultures. The highest yield of 7.75 mg/10 ml was found with a sucrose-asparagine-ammonium medium in which more than 3% of the radioactivity of the added [1-14C]acetate was recovered in the purified [ring-14C] sterigmatocystin. The method offers an easy way to prepare 14C-labeled sterigmatocystin for studies of this mycotoxin. PMID:1110489

Cardiovascular conditions, hearing difficulty, and occupational noise exposure within US industries and occupations.

PubMed

Kerns, Ellen; Masterson, Elizabeth A; Themann, Christa L; Calvert, Geoffrey M

2018-06-01

The purpose of this study was to estimate the prevalence of occupational noise exposure, hearing difficulty and cardiovascular conditions within US industries and occupations, and to examine any associations of these outcomes with occupational noise exposure. National Health Interview Survey data from 2014 were examined. Weighted prevalence and adjusted prevalence ratios of self-reported hearing difficulty, hypertension, elevated cholesterol, and coronary heart disease or stroke were estimated by level of occupational noise exposure, industry, and occupation. Twenty-five percent of current workers had a history of occupational noise exposure (14% exposed in the last year), 12% had hearing difficulty, 24% had hypertension, 28% had elevated cholesterol; 58%, 14%, and 9% of these cases can be attributed to occupational noise exposure, respectively. Hypertension, elevated cholesterol, and hearing difficulty are more prevalent among noise-exposed workers. Reducing workplace noise levels is critical. Workplace-based health and wellness programs should also be considered. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

The bomb 14C transient in the Pacific Ocean

NASA Astrophysics Data System (ADS)

Rodgers, Keith B.; Schrag, Daniel P.; Cane, Mark A.; Naik, Naomi H.

2000-04-01

A modeling study of the bomb 14C transient is presented for the Pacific Ocean. A primitive equation ocean circulation model has been configured for a high-resolution domain that accounts for the Indonesian Throughflow (ITF). Four separate runs were performed: (1) seasonal forcing with 20 Sv of ITF transport, (2) seasonal forcing with 10 Sv of ITF transport, (3) seasonal forcing with no ITF transport, and (4) interannual forcing with 15 Sv of ITF transport. This study has two main objectives. First, it is intended to describe the time evolution of the bomb 14C transient. This serves as a tool with which one can identify the physical processes controlling the evolving bomb 14C distribution in the Pacific thermocline and thus provides an interpretive framework for the database of Δ14C measurements in the Pacific. Second, transient tracers are applied to the physical oceanographic problem of intergyre exchange. This is of importance in furthering our understanding of the potential role of the upper Pacific Ocean in climate variability. We use bomb 14C as a dye tracer of intergyre exchange between the subtropical gyres and the equatorial upwelling regions of the equatorial Pacific. Observations show that while the atmospheric Δ14C signal peaked in the early to mid-1960s, the Δ14C levels in the surface water waters of the subtropical gyres peaked near 1970, and the Δ14C of surface waters in the equatorial Pacific continued to rise through the 1980s. It is shown that the model exhibits skill in representing the large-scale observed features observed for the bomb 14C transient in the Pacific Ocean. The model successfully captures the basin-scale inventories of bomb 14C in the tropics as well as in the extratropics of the North Pacific. For the equatorial Pacific this is attributed to the model's high meridional resolution. The discrepancies in the three-dimensional distribution of bomb 14C between the model and data are discussed within the context of the dynamical

14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

Code of Federal Regulations, 2010 CFR

2010-01-01

... occupancy fee will be zero. For a postponed or cancelled shared flight, the occupancy fee will be computed... which is less than zero, the occupancy fee will be reset to zero. For a postponed or cancelled shared flight one year or less, but more than six months before launch, the user shall reimburse NASA an...

Distribution and biomarker of carbon-14 labeled fullerene C60 ([(14) C(U)]C60 ) in pregnant and lactating rats and their offspring after maternal intravenous exposure.

PubMed

Snyder, Rodney W; Fennell, Timothy R; Wingard, Christopher J; Mortensen, Ninell P; Holland, Nathan A; Shannahan, Jonathan H; Pathmasiri, Wimal; Lewin, Anita H; Sumner, Susan C J

2015-12-01

A comprehensive distribution study was conducted in pregnant and lactating rats exposed to a suspension of uniformly carbon-14 labeled C60 ([(14) C(U)]C60 ). Rats were administered [(14) C(U)]C60 (~0.2 mg [(14) C(U)]C60 kg(-1) body weight) or 5% polyvinylpyrrolidone (PVP)-saline vehicle via a single tail vein injection. Pregnant rats were injected on gestation day (GD) 11 (terminated with fetuses after either 24 h or 8 days), GD15 (terminated after 24 h or 4 days), or GD18 (terminated after 24 h). Lactating rats were injected on postnatal day 8 and terminated after 24 h, 3 or 11 days. The distribution of radioactivity in pregnant dams was influenced by both the state of pregnancy and time of termination after exposure. The percentage of recovered radioactivity in pregnant and lactating rats was highest in the liver and lungs. Radioactivity was quantitated in over 20 tissues. Radioactivity was found in the placenta and in fetuses of pregnant dams, and in the milk of lactating rats and in pups. Elimination of radioactivity was < 2% in urine and feces at each time point. Radioactivity remained in blood circulation up to 11 days after [(14) C(U)]C60 exposure. Biomarkers of inflammation, cardiovascular injury and oxidative stress were measured to study the biological impacts of [(14) C(U)]C60 exposure. Oxidative stress was elevated in female pups of exposed dams. Metabolomics analysis of urine showed that [(14) C(U)]C60 exposure to pregnant rats impacted the pathways of vitamin B, regulation of lipid and sugar metabolism and aminoacyl-tRNA biosynthesis. This study demonstrated that [(14) C(U)]C60 crosses the placenta at all stages of pregnancy examined, and is transferred to pups via milk. Copyright © 2015 John Wiley & Sons, Ltd.

Update on the Us Army’s Fuel Contamination Detection Efforts

DTIC Science & Technology

2011-04-04

Dual Eng flameout Contaminated with water and particulate 14 2009 C-130 USAF Jet Fuel Contamination with Fatty Acid Methyl Ester ( FAME ) BioFuel 15 20...DRNEN. WARRGHTER FOCUSED. Summary of Incidents • US Air Force – 2 - T-37 Super Absorbent Polymer 1 C 130 FAME Fatty Methyl Ester

C14 Assays and Autoradiographic Studies on the Rooster Comb

PubMed Central

Balazs, Endre A.; Szirmai, John A.; Bergendahl, Gudrun

1959-01-01

The distribution of C14 was studied in various parts of the rooster comb following treatment with testosterone. The value of gas-phase assay of C14 in tissue has been demonstrated and the results compared with those of autoradiographic studies on the same tissue. The results of these experiments showed that androgen treatment significantly increases the rate of incorporation of C14 in various parts of the comb. The specific activity of carbon in the comb, cornea, and liver differed, depending on which precursor, viz. glucose-6-C14, glucose-1-C14, and glucuronolactone-U-C14, was administered. The highest values were obtained after the administration of glucose-6-C14; glucuronolactone-U-C14 gave the lowest specific activity. The specific activity of carbon in different parts of the comb showed considerable variation. Carbon assay of serial sections of the comb cut at various planes showed that the specific activity of carbon was highest in the mucoid layer. Both C14 assays and autoradiograms indicate that C14 is also present in other parts of the comb. As seen in autoradiography, the concentration of C14 was highest in the epithelium, in the blood vessel walls, and in the avascular collagenous tissue. These results, and indications from previous studies, suggest that the high specific activity of carbon in the mucoid layer is due mainly to the presence of C14-labelled hyaluronic acid. Autoradiograms and PAS staining suggest that a significant amount of C14 is also incorporated into the glycoproteins associated with the collagen fibers. PMID:13654453

Hepatitis C

MedlinePlus

... virus (HCV) spreads through contaminated blood. Until recently, hepatitis C treatment required weekly injections and oral medications that many ... have varied from 14 to 50 percent. Acute hepatitis C also responds well to antiviral therapy. Causes Hepatitis C infection is caused by the ...

Occupational Status and Suicide.

ERIC Educational Resources Information Center

Lampert, Dominique I.; And Others

1984-01-01

Examined relationship between occupational status and suicide in California males since 1925. Findings show an inverse relationship between occupational status and suicide for all age groups. Over time, male suicide rates have increased, particularly for employed males over 65, employed males aged 14 to 24, and males in low-status occupations.…

Occupational medical prophylaxis for the musculoskeletal system: A function-oriented system for physical examination of the locomotor system in occupational medicine (fokus(C)).

PubMed

Spallek, Michael; Kuhn, Walter; Schwarze, Sieglinde; Hartmann, Bernd

2007-10-29

Occupational physicians are very often confronted with questions as to the fitness of the postural and locomotor systems, especially the spinal column. Occupational medical assessment and advice can be required by patients with acute symptoms, at routine check-ups, by persons who have problems doing certain jobs, and for expert medical reports as to the fitness of persons with chronic disorders or after operations. Therefore, for occupational medical purposes a physical examination must aim primarily to investigate functions and not structures or radiologic evidence. The physical examination should be structured systematically and according to regions of the body and, together with a specific (pain) anamnesis should provide a basis for the medical assessment.This paper presents a function-oriented system for physical examination of the locomotor system, named fokus(C) (Funktionsorientierte Koerperliche Untersuchungssystematik, also available on DVD). fokus(C) has been developed with a view to its relevance for occupational medical practice and does not aim primarily to provide a precise diagnosis. Decisive for an occupational medical assessment of disorders of the musculoskeletal system is rather information about functional disorders and any impairment of performance or mobility which they can cause. The division of the physical examination into a rapid screening phase and a subsequent more intensive functional diagnostic phase has proved its practicability in many years of day-to-day use. Here, in contrast to the very extensive measures recommended for orthopaedic and manual diagnosis, for reasons of efficiency and usability of the system in routine occupational medical examinations the examination is structured according to the findings. So it is reduced to that which is most necessary and feasible.

Improved radiocarbon dating for contaminated archaeological bone collagen, silk, wool and hair samples via cross-flow nanofiltrated amino acids.

PubMed

Boudin, Mathieu; Boeckx, Pascal; Vandenabeele, Peter; Van Strydonck, Mark

2013-09-30

Radiocarbon dating and stable isotope analyses of bone collagen, wool, hair and silk contaminated with extraneous carbon (e.g. humic substances) does not yield reliable results if these materials are pre-treated using conventional methods. A cross-flow nanofiltration method was developed that can be applied to various protein materials like collagen, hair, silk, wool and leather, and should be able to remove low-molecular and high-molecular weight contaminants. To avoid extraneous carbon contamination via the filter a ceramic filter (molecular weight cut-off of 200 Da) was used. The amino acids, released by hot acid hydrolysis of the protein material, were collected in the permeate and contaminants in the retentate (>200 Da). (14)C-dating results for various contaminated archaeological samples were compared for bulk material (pre-treated with the conventional methods) and for cross-flow nanofiltrated amino acids (permeate) originating from the same samples. Contamination and quality control of (14)C dates of bulk and permeate samples were obtained by measuring C:N ratios, fluorescence spectra, and δ(13)C and δ(15)N values of the samples. Cross-flow nanofiltration decreases the C:N ratio which means that contaminants have been removed. Cross-flow nanofiltration clearly improved sample quality and (14)C results. It is a quick and non-labor-intensive technique and can easily be implemented in any (14)C and stable isotope laboratory for routine sample pre-treatment analyses. Copyright © 2013 John Wiley & Sons, Ltd.

The occupational health and safety of flight attendants.

PubMed

Griffiths, Robin F; Powell, David M C

2012-05-01

In order to perform safety-critical roles in emergency situations, flight attendants should meet minimum health standards and not be impaired by factors such as fatigue. In addition, the unique occupational and environmental characteristics of flight attendant employment may have consequential occupational health and safety implications, including radiation exposure, cancer, mental ill-health, musculoskeletal injury, reproductive disorders, and symptoms from cabin air contamination. The respective roles of governments and employers in managing these are controversial. A structured literature review was undertaken to identify key themes for promoting a future agenda for flight attendant health and safety. Recommendations include breast cancer health promotion, implementation of Fatigue Risk Management Systems, standardization of data collection on radiation exposure and health outcomes, and more coordinated approaches to occupational health and safety risk management. Research is ongoing into cabin air contamination incidents, cancer, and fatigue as health and safety concerns. Concerns are raised that statutory medical certification for flight attendants will not benefit either flight safety or occupational health.

Occupation and relative risk of cutaneous squamous cell carcinoma (cSCC): A 45-year follow-up study in 4 Nordic countries.

PubMed

Alfonso, Jose Hernán; Martinsen, Jan Ivar; Pukkala, Eero; Weiderpass, Elisabete; Tryggvadottir, Laufey; Nordby, Karl-Christian; Kjærheim, Kristina

2016-09-01

The age-adjusted incidence of cutaneous squamous cell carcinoma (cSCC) in the Nordic countries has increased during the last 60 years, and the identification of occupational variation in the relative risk of cSCC may have preventive implications. We sought to describe variation in the relative risk of cSCC between occupational categories in Finland, Iceland, Norway, and Sweden. This is a historical prospective cohort study based on record linkages between census data for 12.9 million people and cancer registry data from 1961 to 2005. Standardized incidence ratios for cSCC were estimated for 53 occupational categories with the cSCC incidence rates for the national population of each country used as reference. During follow-up, 87,619 incident cases of cSCC were reported to the national cancer registries. In all countries combined, significant increased standardized incidence ratios were observed among seamen, military personnel, public safety workers, technical workers, teachers, transport workers, physicians, dentists, nurses, other health workers, religious workers, clerical workers, administrators, and sale agents (standardized incidence ratios between 1.08 and 1.77). Information on occupation was based on 1 point in time only. The occupational variation of the relative risk of cSCC might be associated with socioeconomic factors, and to some extent to occupational exposures. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Occupational exposure to airborne contaminants during offshore oil drilling.

PubMed

Kirkhus, Niels E; Thomassen, Yngvar; Ulvestad, Bente; Woldbæk, Torill; Ellingsen, Dag G

2015-07-01

The aim was to study exposure to airborne contaminants in oil drillers during ordinary work. Personal samples were collected among 65 drill floor workers on four stationary and six moveable rigs in the Norwegian offshore sector. Air concentrations of drilling mud were determined based on measurements of the non-volatile mud components Ca and Fe. The median air concentration of mud was 140 μg m(-3). Median air concentrations of oil mist (180 μg m(-3)), oil vapour (14 mg m(-3)) and organic carbon (46 μg m(-3)) were also measured. All contaminants were detected in all work areas (drill floor, shaker area, mud pits, pump room, other areas). The highest air concentrations were measured in the shaker area, but the differences in air concentrations between working areas were moderate. Oil mist and oil vapour concentrations were statistically higher on moveable rigs than on stationary rigs, but after adjusting for differences in mud temperature the differences between rig types were no longer of statistical significance. Statistically significant positive associations were found between mud temperature and the concentrations of oil mist (Spearman's R = 0.46) and oil vapour (0.39), and between viscosity of base oil and oil mist concentrations. Use of pressure washers was associated with higher air concentrations of mud. A series of 18 parallel stationary samples showed a high and statistically significant association between concentrations of organic carbon and oil mist (r = 0.98). This study shows that workers are exposed to airborne non-volatilized mud components. Air concentrations of volatile mud components like oil mist and oil vapour were low, but were present in all the studied working areas.

Discussion: Reporting and calibration of post-bomb 14C data

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

Reimer, P J; Brown, T A; Reimer, R W

2004-10-11

The definitive paper by Stuiver and Polach (1977) established the conventions for reporting of {sup 14}C data for chronological and geophysical studies based on the radioactive decay of {sup 14}C in the sample since the year of sample death or formation. Several ways of reporting {sup 14}C activity levels relative to a standard were also established, but no specific instructions were given for reporting nuclear weapons testing (post-bomb) {sup 14}C levels in samples. Because the use of post-bomb {sup 14}C is becoming more prevalent in forensics, biology, and geosciences, a convention needs to be adopted. We advocate the use ofmore » fraction modern with a new symbol F{sup 14}C to prevent confusion with the previously used Fm, which may or may not have been fractionation corrected. We also discuss the calibration of post-bomb {sup 14}C samples and the available datasets and compilations, but do not give a recommendation for a particular dataset.« less

Kinetic study of benzyl [1-14C]acetate as a potential probe for astrocytic energy metabolism in the rat brain: Comparison with benzyl [2-14C]acetate.

PubMed

Okada, Maki; Yanamoto, Kazuhiko; Kagawa, Tomohiko; Yoshino, Keiko; Hosoi, Rie; Abe, Kohji; Zhang, Ming-Rong; Inoue, Osamu

2016-02-01

Brain uptake of [(14)C]acetate has been reported to be a useful marker of astrocytic energy metabolism. In addition to uptake values, the rate of radiolabeled acetate washout from the brain appears to reflect CO2 exhaustion and oxygen consumption in astrocytes. We measured the time-radioactivity curves of benzyl [1-(14)C]acetate ([1-(14)C]BA), a lipophilic probe of [1-(14)C]acetate, and compared it with that of benzyl [2-(14)C]acetate ([2-(14)C]BA) in rat brains. The highest brain uptake was observed immediately after injecting either [1-(14)C]BA or [2-(14)C]BA, and both subsequently disappeared from the brain in a single-exponential manner. Estimated [1-(14)C]BA washout rates in the cerebral cortex and cerebellum were higher than those of [2-(14)C]BA. These results suggested that [1-(14)C]BA could be a useful probe for estimating the astrocytic oxidative metabolism. The [1-(14)C]BA washout rate in the cerebral cortex of immature rats was lower than that of mature rats. An autoradiographic study showed that the washout rates of [1-(14)C]BA from the rat brains of a lithium-pilocarpine-induced status epilepticus model were not significantly different from the values in control rat brains except for the medial septal nucleus. These results implied that the enhancement of amino acid turnover rate rather than astrocytic oxidative metabolism was increased in status epilepticus. © The Author(s) 2015.

Measurements of 14C in ancient ice from Taylor Glacier, Antarctica constrain in situ cosmogenic 14CH4 and 14CO production rates

NASA Astrophysics Data System (ADS)

Petrenko, Vasilii V.; Severinghaus, Jeffrey P.; Schaefer, Hinrich; Smith, Andrew M.; Kuhl, Tanner; Baggenstos, Daniel; Hua, Quan; Brook, Edward J.; Rose, Paul; Kulin, Robb; Bauska, Thomas; Harth, Christina; Buizert, Christo; Orsi, Anais; Emanuele, Guy; Lee, James E.; Brailsford, Gordon; Keeling, Ralph; Weiss, Ray F.

2016-03-01

Carbon-14 (14C) is incorporated into glacial ice by trapping of atmospheric gases as well as direct near-surface in situ cosmogenic production. 14C of trapped methane (14CH4) is a powerful tracer for past CH4 emissions from ;old; carbon sources such as permafrost and marine CH4 clathrates. 14C in trapped carbon dioxide (14CO2) can be used for absolute dating of ice cores. In situ produced cosmogenic 14C in carbon monoxide (14CO) can potentially be used to reconstruct the past cosmic ray flux and past solar activity. Unfortunately, the trapped atmospheric and in situ cosmogenic components of 14C in glacial ice are difficult to disentangle and a thorough understanding of the in situ cosmogenic component is needed in order to extract useful information from ice core 14C. We analyzed very large (≈1000 kg) ice samples in the 2.26-19.53 m depth range from the ablation zone of Taylor Glacier, Antarctica, to study in situ cosmogenic production of 14CH4 and 14CO. All sampled ice is >50 ka in age, allowing for the assumption that most of the measured 14C originates from recent in situ cosmogenic production as ancient ice is brought to the surface via ablation. Our results place the first constraints on cosmogenic 14CH4 production rates and improve on prior estimates of 14CO production rates in ice. We find a constant 14CH4/14CO production ratio (0.0076 ± 0.0003) for samples deeper than 3 m, which allows the use of 14CO for correcting the 14CH4 signals for the in situ cosmogenic component. Our results also provide the first unambiguous confirmation of 14C production by fast muons in a natural setting (ice or rock) and suggest that the 14C production rates in ice commonly used in the literature may be too high.

Forensic applications of 14C bomb-pulse dating

NASA Astrophysics Data System (ADS)

Zoppi, U.; Skopec, Z.; Skopec, J.; Jones, G.; Fink, D.; Hua, Q.; Jacobsen, G.; Tuniz, C.; Williams, A.

2004-08-01

After a brief review of the basics of 14C bomb-pulse dating, this paper presents two unique forensic applications. Particular attention is dedicated to the use of the 14C bomb-pulse to establish the time of harvest of illicit drugs such as heroin and opium. Preliminary measurements of 14C concentrations in milligram samples taken from seized drugs are presented. 14C bomb-pulse dating can determine whether drug distribution originates from stockpiles or recent manufacture, and support the action of law enforcement authorities against criminal organisations involved in drug trafficking. In addition, we describe the dating of wine vintages for a number of authenticated single label vintage red wines from the Barossa Valley - South Australia. Our results show that radiocarbon dating can be used to accurately determine wine vintages and therefore reveal the addition of unrelated materials of natural and synthetic origin.

Behavior of Listeria monocytogenes at 7 degrees C in commercial turkey breast, with or without antimicrobials, after simulated contamination for manufacturing, retail and consumer settings.

PubMed

Lianou, Alexandra; Geornaras, Ifigenia; Kendall, Patricia A; Scanga, John A; Sofos, John N

2007-08-01

Uncured turkey breast, commercially available with or without a mixture of potassium lactate and sodium diacetate, was sliced, inoculated with a 10-strain composite of Listeria monocytogenes, vacuum-packaged, and stored at 4 degrees C, to simulate contamination after a lethal processing step at the plant. At 5, 15, 25 and 50 days of storage, packages were opened, slices were tested, and bags with remaining slices were reclosed with rubber bands; this simulated home use of plant-sliced and -packaged product. At the same above time intervals, portions of original product (stored at 4 degrees C in original processing bags) were sliced and inoculated as above, and packaged in delicatessen bags, simulating contamination during slicing/handling at retail or home. Both sets of bags were stored aerobically at 7 degrees C for 12 days to simulate home storage. L. monocytogenes populations were lower (P<0.05) during storage in turkey breast containing a combination of lactate and diacetate compared to product without antimicrobials under both contamination scenarios. Due to prolific growth of the pathogen under the plant-contamination scenario in product without lactate-diacetate during vacuum-packaged storage (4 degrees C), populations at 3 days of aerobic storage (7 degrees C) of such product ranged from 4.6 to 7.4 log cfu/cm(2). Under the retail/home-contamination scenario, mean growth rates (log cfu/cm(2)/day) of the organism during aerobic storage ranged from 0.14 to 0.16, and from 0.25 to 0.51, in product with and without lactate-diacetate, respectively; growth rates in turkey breast without antimicrobials decreased (P<0.05) with age of the product. Overall, product without antimicrobials inoculated to simulate plant-contamination and product with lactate-diacetate inoculated to simulate retail/home-contamination were associated with the highest and lowest pathogen levels during aerobic storage at 7 degrees C, respectively. However, 5- and 15-day-old turkey breast

The enzymic preparation of (14)C-kaurene.

PubMed

Graebe, J E

1969-06-01

Endosperm from immature seeds of Cucurbita pepo L. converts 2-(14)C-DL-mevalonate to (14)C-(-)-kaurene with a yield of nearly 40% of the active isomer. Kaurene is the main product and the only diterpene hydrocarbon which is formed from mevalonate in the system and is therefore easily obtained radiochemically pure. The product was identified by thin-layer chromatography and recrystallization with authentic (-)-kaurene to constant specific radioactivity.

14C tebuconazole degradation in Colombian soils.

PubMed

Mosquera, C S; Martínez, M J; Guerrero, J A

2010-01-01

Tebuconazole is a fungicide used on onion crops (Allium Fistulosum L) in Colombia. Persistence of pesticides in soils is characterized by the half-life (DT50), which is influenced by their chemical structure, the physical and chemical properties of the soil and the previous soil history. Based on its structural and chemical properties, tebuconazole should be expected to be relatively persistent in soils. Laboratory incubation studies were conducted to evaluate persistence and bond residues of 14C tebuconazole in three soils, two inceptisol (I) and one histosol (H). Textural classifications were: loam (101), loamy sand (102) and loam (H03), respectively. Data obtained followed a first-order degradation kinetics (R2 > or = 0.899) with DT50 values between 158 and 198 days. The production of 14CO2 from the 14C-ring-labelled test chemicals was very low and increased slightly during 63 days in all cases. The methanol extractable 14C-residues were higher than aqueous ones and both decreased over incubation time for the three soils. The formation of bound 14C-residues increased with time and final values were 11.3; 5.55 and 7.87% for 101, 102 and H03 respectively. Soil 101 showed the lowest mineralization rate and the highest bound residues formation, which might be explained by the clay fraction content. In contrast, an inverse behavior was found for soils 102 and H03, these results might be explained by the higher soil organic carbon content.

Hanford Tanks 241-C-203 and 241 C 204: Residual Waste Contaminant Release Model and Supporting Data

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

Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.

This report was revised in May 2007 to correct 90Sr values in Chapter 3. The changes were made on page 3.9, paragraph two and Table 3.10; page 3.16, last paragraph on the page; and Tables 3.21 and 3.31. The rest of the text remains unchanged from the original report issued in October 2004. This report describes the development of release models for key contaminants that are present in residual sludge remaining after closure of Hanford Tanks 241-C-203 (C-203) and 241-C-204 (C-204). The release models were developed from data generated by laboratory characterization and testing of samples from these two tanks.more » Key results from this work are (1) future releases from the tanks of the primary contaminants of concern (99Tc and 238U) can be represented by relatively simple solubility relationships between infiltrating water and solid phases containing the contaminants; and (2) high percentages of technetium-99 in the sludges (20 wt% in C-203 and 75 wt% in C-204) are not readily water leachable, and, in fact, are very recalcitrant. This is similar to results found in related studies of sludges from Tank AY-102. These release models are being developed to support the tank closure risk assessments performed by CH2M HILL Hanford Group, Inc., for the U.S. Department of Energy.« less

14 CFR 71.51 - Class C airspace.

Code of Federal Regulations, 2013 CFR

2013-01-01

... DESIGNATION OF CLASS A, B, C, D, AND E AIRSPACE AREAS; AIR TRAFFIC SERVICE ROUTES; AND REPORTING POINTS Class C Airspace § 71.51 Class C airspace. The Class C airspace areas listed in subpart C of FAA Order... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Class C airspace. 71.51 Section 71.51...

14 CFR 71.51 - Class C airspace.

Code of Federal Regulations, 2010 CFR

2010-01-01

... DESIGNATION OF CLASS A, B, C, D, AND E AIRSPACE AREAS; AIR TRAFFIC SERVICE ROUTES; AND REPORTING POINTS Class C Airspace § 71.51 Class C airspace. The Class C airspace areas listed in subpart C of FAA Order... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Class C airspace. 71.51 Section 71.51...

17 CFR 240.14c-101 - Schedule 14C. Information required in information statement.

Code of Federal Regulations, 2014 CFR

2014-04-01

... separate copy of the annual report to security holders, information statement, or Notice of Internet... annual reports to security holders, information statements, or Notices of Internet Availability of Proxy... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Schedule 14C. Information...

17 CFR 240.14c-101 - Schedule 14C. Information required in information statement.

Code of Federal Regulations, 2013 CFR

2013-04-01

... separate copy of the annual report to security holders, information statement, or Notice of Internet... annual reports to security holders, information statements, or Notices of Internet Availability of Proxy... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Schedule 14C. Information...

17 CFR 240.14c-101 - Schedule 14C. Information required in information statement.

Code of Federal Regulations, 2012 CFR

2012-04-01

... separate copy of the annual report to security holders, information statement, or Notice of Internet... annual reports to security holders, information statements, or Notices of Internet Availability of Proxy... 17 Commodity and Securities Exchanges 3 2012-04-01 2012-04-01 false Schedule 14C. Information...

Autoradiographic disposition of (1-methyl-/sup 14/C)- and (2-/sup 14/C)caffeine in mice

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

Lachance, M.P.; Marlowe, C.; Waddell, W.J.

1983-11-01

Male, C57B1/6J mice received either (1-methyl-14C)caffeine or (2-14C)caffeine via the tail vein at a dose of 0.7 or 11 mg/kg, respectively. At 0.1, 0.33, 1, 3, 9, and 24 hr after treatment, the mice were anesthetized with ether and frozen by immersion in dry ice/hexane. The mice were processed for whole-body autoradiography by the Ullberg technique; this procedure does not allow thawing or contact with solvents. All autoradiographs revealed some retention of radioactivity at early time intervals in the lacrimal glands, seminal vesicle fluid, nasal and olfactory epithelium, and retinal melanocytes. The remaining portion of the animal was densitometrically uniformmore » except for the lower levels noted in the CNS and adipose tissues. Excretion of radioactivity by the liver and kidneys seems to be the major routes of elimination. Localization in the liver at late time intervals was confined principally to the centrilobular region. Late sites of retention, observed only after (1-methyl-14C)caffeine administration, included the pancreas, minor and major salivary glands, splenic red pulp, thymal cortex, bone marrow, and gastrointestinal epithelium. Sites of localization present in both studies included the olfactory epithelium, lacrimal glands, hair follicles, and retinal melanocytes. Further studies are needed to determine whether the localization at these various sites is due to metabolic degradation, active transport, or possibly a specific receptor interaction.« less

Pyrolysis-combustion 14C dating of soil organic matter

USGS Publications Warehouse

Wang, Hongfang; Hackley, Keith C.; Panno, S.V.; Coleman, D.D.; Liu, J.C.-L.; Brown, J.

2003-01-01

Radiocarbon (14C) dating of total soil organic matter (SOM) often yields results inconsistent with the stratigraphic sequence. The onerous chemical extractions for SOM fractions do not always produce satisfactory 14C dates. In an effort to develop an alternative method, the pyrolysis-combustion technique was investigated to partition SOM into pyrolysis volatile (Py-V) and pyrolysis residue (Py-R) fractions. The Py-V fractions obtained from a thick glacigenic loess succession in Illinois yielded 14C dates much younger but more reasonable than the counterpart Py-R fractions for the soil residence time. Carbon isotopic composition (??13C) was heavier in the Py-V fractions, suggesting a greater abundance of carbohydrate- and protein-related constituents, and ??13C was lighter in the Py-R fractions, suggesting more lignin- and lipid-related constituents. The combination of 14C dates and ??13C values indicates that the Py-V fractions are less biodegradation resistant and the Py-R fractions are more biodegradation resistant. The pyrolysis-combustion method provides a less cumbersome approach for 14C dating of SOM fractions. With further study, this method may become a useful tool for analyzing unlithified terrestrial sediments when macrofossils are absent. ?? 2003 University of Washington. Published by Elsevier Inc. All rights reserved.

Spectroscopic methods for aqueous cyclodextrin inclusion complex binding measurement for 1,4-dioxane, chlorinated co-contaminants, and ozone

NASA Astrophysics Data System (ADS)

Khan, Naima A.; Johnson, Michael D.; Carroll, Kenneth C.

2018-03-01

Recalcitrant organic contaminants, such as 1,4-dioxane, typically require advanced oxidation process (AOP) oxidants, such as ozone (O3), for their complete mineralization during water treatment. Unfortunately, the use of AOPs can be limited by these oxidants' relatively high reactivities and short half-lives. These drawbacks can be minimized by partial encapsulation of the oxidants within a cyclodextrin cavity to form inclusion complexes. We determined the inclusion complexes of O3 and three common co-contaminants (trichloroethene, 1,1,1-trichloroethane, and 1,4-dioxane) as guest compounds within hydroxypropyl-β-cyclodextrin. Both direct (ultraviolet or UV) and competitive (fluorescence changes with 6-p-toluidine-2-naphthalenesulfonic acid as the probe) methods were used, which gave comparable results for the inclusion constants of these species. Impacts of changing pH and NaCl concentrations were also assessed. Binding constants increased with pH and with ionic strength, which was attributed to variations in guest compound solubility. The results illustrate the versatility of cyclodextrins for inclusion complexation with various types of compounds, binding measurement methods are applicable to a wide range of applications, and have implications for both extraction of contaminants and delivery of reagents for treatment of contaminants in wastewater or contaminated groundwater.

Using [11C]diprenorphine to image opioid receptor occupancy by methadone in opioid addiction: clinical and preclinical studies.

PubMed

Melichar, Jan K; Hume, Susan P; Williams, Tim M; Daglish, Mark R C; Taylor, Lindsay G; Ahmad, Rabia; Malizia, Andrea L; Brooks, David J; Myles, Judith S; Lingford-Hughes, Anne; Nutt, David J

2005-01-01

Substitute methadone prescribing is one of the main modes of treatment for opioid dependence with established evidence for improved health and social outcomes. However, the pharmacology underpinning the effects of methadone is little studied despite controversies about dosing in relation to outcome. We therefore examined the relationship between methadone dose and occupation of opioid receptors in brain using the positron emission tomography (PET) radioligand [(11)C]diprenorphine in humans and rats. Eight opioid-dependent subjects stable on their substitute methadone (18-90 mg daily) had an [(11)C]diprenorphine PET scan at predicted peak plasma levels of methadone. These were compared with eight healthy controls. No difference in [(11)C]diprenorphine binding was found between the groups, with no relationship between methadone dose and occupancy. Adult male Sprague-Dawley rats that had been given an acute i.v. injection of methadone hydrochloride (0.35, 0.5, 0.7, or 1.0 mg kg(-1)) before [(11)C]diprenorphine showed a dose-dependent increase in biodistribution but no reduction in [(11)C]diprenorphine binding. We suggest that the lack of a dose-dependent relationship between methadone dose, either given chronically in human or acutely in rat, and occupancy of opioid receptor measured with [(11)C]diprenorphine PET is related to efficacy of this opioid agonist at very low levels of opioid receptor occupancy. This has implications for understanding the actions of methadone in comparison with other opioid drugs such as partial agonists and antagonists.

Mild acid and alkali treated clay minerals enhance bioremediation of polycyclic aromatic hydrocarbons in long-term contaminated soil: A 14C-tracer study.

PubMed

Biswas, Bhabananda; Sarkar, Binoy; Rusmin, Ruhaida; Naidu, Ravi

2017-04-01

Bioremediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soils requires a higher microbial viability and an increased PAH bioavailability. The clay/modified clay-modulated bacterial degradation could deliver a more efficient removal of PAHs in soils depending on the bioavailability of the compounds. In this study, we modified clay minerals (smectite and palygorskite) with mild acid (HCl) and alkali (NaOH) treatments (0.5-3 M), which increased the surface area and pore volume of the products, and removed the impurities without collapsing the crystalline structure of clay minerals. In soil incubation studies, supplements with the clay products increased bacterial growth in the order: 0.5 M HCl ≥ unmodified ≥ 0.5 M NaOH ≥ 3 M NaOH ≥ 3 M HCl for smectite, and 0.5 M HCl ≥ 3 M NaOH ≥ 0.5 M NaOH ≥ 3 M HCl ≥ unmodified for palygorskite. A 14 C-tracing study showed that the mild acid/alkali-treated clay products increased the PAH biodegradation (5-8%) in the order of 0.5 M HCl ≥ unmodified > 3 M NaOH ≥ 0.5 M NaOH for smectite, and 0.5 M HCl > 0.5 M NaOH ≥ unmodified ≥ 3 M NaOH for palygorskite. The biodegradation was correlated (r = 0.81) with the bioavailable fraction of PAHs and microbial growth as affected particularly by the 0.5 M HCl and 0.5 M NaOH-treated clay minerals. These results could be pivotal in developing a clay-modulated bioremediation technology for cleaning up PAH-contaminated soils and sediments in the field. Copyright © 2017 Elsevier Ltd. All rights reserved.

Occupational Therapy in Medicaid Home and Community-Based Services Waivers.

PubMed

Friedman, Carli; VanPuymbrouck, Laura

Medicaid Home and Community-Based Services (HCBS) 1915(c) waivers are the largest provider of long-term services and supports for people with intellectual and developmental disabilities (IDDs). In this study, we explored how HCBS IDD waivers projected providing occupational therapy services in Fiscal Year (FY) 2015. Medicaid HCBS IDD waivers across the nation gathered from the Centers for Medicare and Medicaid Services were qualitatively and quantitatively analyzed to determine how they projected providing occupational therapy services in terms of service expenditures and utilization. In FY 2015, $14.13 million of spending was projected for occupational therapy services of 7,500 participants. However, there was large heterogeneity across states and services in terms of total projected spending, spending per participant, and reimbursement rates. Comparisons across states strengthen the profession's ability to assert the value of its services. These findings can help identify best practices and can advocate for the refinement of state occupational therapy programs. Copyright © 2018 by the American Occupational Therapy Association, Inc.

Occupational exposures and asthma in 14,000 adults from the general population

PubMed Central

Le Moual, Nicole; Kennedy, Susan M.; Kauffmann, Francine

2004-01-01

The association of occupational exposures and asthma were studied in 14151 adults, aged 25–59 years, from the general population of the French PAARC (Pollution Atmospherique et Affections Respiratoires Chroniques, 1975) Survey. Associations of asthma to specific jobs such as personal care workers, waiters, stock clerks were observed, with age, sex, smoking adjusted odds ratios between 1.5 and 1.7. Exposures to 18 asthmagenic agents (low, high molecular weight and mixed environment) were estimated by an asthma-specific job exposure matrix. Risks associated with asthma increased when excluding subjects with imprecise estimates of exposure. Risks further increased when increasing specificity of the definition of asthma considering jobs or specific agents such as industrial cleaning agents, latex, flour, highly reactive chemicals, and textiles. For example, for industrial cleaning agents, odds ratios increased from 1.55 (95% CI: 1.08, 2.23) for ever asthma, to 2.51 (95% CI: 1.33, 4.75) for asthma with airflow limitation, to 2.17 (95% CI: 1.41, 3.34) for asthma onset after age 14, and to 2.35 (95% CI: 1.38, 4.00) for asthma onset after beginning of current job. Results underlined the importance of the specificity of exposure and asthma definitions and indicated a deleterious role of occupational exposure on asthma, especially for cleaning agents. PMID:15561990

Occupational asthma in greenhouse workers.

PubMed

Monsó, Eduard

2004-03-01

A prevalence of asthma over 5% has been reported in flower farmers,and work inside greenhouses has emerged as an additional risk factor. Workplace determinants behind this high prevalence has been examined, and a prevalence of sensitization to workplace allergens over 30% has been reported being pollens, moulds, and Tetranychus urticae allergens the main sensitizers. Bronchial challenge tests in the workplace have demonstrated occupational asthma in more than 20% of the sensitized greenhouse growers. Air contamination inside greenhouses is mainly related to moulds, and is facilitated by the high indoor temperature and humidity. Cladosporium, Penicillium, Aspergillus, and Alternaria and a wide range of flower pollens are able to sensitize the greenhouse worker and cause occupational asthma. Tetranychus urticae have allergens shared with other mites, but the low prevalence of cross-sensitization between them confirm that Tetranychus urticae contains species-specific allergens that may cause respiratory symptoms. Additionally, working inside greenhouses has been related to an increase in the prevalence of chronic bronchitis in nonsmokers. The cultivation of greenhouse crops may cause occupational asthma through sensitization to workplace pollens, moulds, and Tetranychus urticae allergens. In greenhouse flower growers, skin testing identifies sensitization to these allergens in one third of the growers, and more than one fifth of the sensitized workers will develop occupational asthma. Greenhouse work has also been related to chronic bronchitis in nonsmokers, suggesting a causal effect of greenhouse air contaminants on this disease as well.

TMEM14C is required for erythroid mitochondrial heme metabolism

PubMed Central

Yien, Yvette Y.; Robledo, Raymond F.; Schultz, Iman J.; Takahashi-Makise, Naoko; Gwynn, Babette; Bauer, Daniel E.; Dass, Abhishek; Yi, Gloria; Li, Liangtao; Hildick-Smith, Gordon J.; Cooney, Jeffrey D.; Pierce, Eric L.; Mohler, Kyla; Dailey, Tamara A.; Miyata, Non; Kingsley, Paul D.; Garone, Caterina; Hattangadi, Shilpa M.; Huang, Hui; Chen, Wen; Keenan, Ellen M.; Shah, Dhvanit I.; Schlaeger, Thorsten M.; DiMauro, Salvatore; Orkin, Stuart H.; Cantor, Alan B.; Palis, James; Koehler, Carla M.; Lodish, Harvey F.; Kaplan, Jerry; Ward, Diane M.; Dailey, Harry A.; Phillips, John D.; Peters, Luanne L.; Paw, Barry H.

2014-01-01

The transport and intracellular trafficking of heme biosynthesis intermediates are crucial for hemoglobin production, which is a critical process in developing red cells. Here, we profiled gene expression in terminally differentiating murine fetal liver-derived erythroid cells to identify regulators of heme metabolism. We determined that TMEM14C, an inner mitochondrial membrane protein that is enriched in vertebrate hematopoietic tissues, is essential for erythropoiesis and heme synthesis in vivo and in cultured erythroid cells. In mice, TMEM14C deficiency resulted in porphyrin accumulation in the fetal liver, erythroid maturation arrest, and embryonic lethality due to profound anemia. Protoporphyrin IX synthesis in TMEM14C-deficient erythroid cells was blocked, leading to an accumulation of porphyrin precursors. The heme synthesis defect in TMEM14C-deficient cells was ameliorated with a protoporphyrin IX analog, indicating that TMEM14C primarily functions in the terminal steps of the heme synthesis pathway. Together, our data demonstrate that TMEM14C facilitates the import of protoporphyrinogen IX into the mitochondrial matrix for heme synthesis and subsequent hemoglobin production. Furthermore, the identification of TMEM14C as a protoporphyrinogen IX importer provides a genetic tool for further exploring erythropoiesis and congenital anemias. PMID:25157825

Effect of contaminant concentration on aerobic microbial mineralization of DCE and VC in stream-bed sediments

USGS Publications Warehouse

Bradley, P.M.; Chapelle, F.H.

1998-01-01

Discharge of DCE and VC to an aerobic surface water system simultaneously represents a significant environmental concern and, potentially, a non-engineered opportunity for efficient contaminant bioremediation. The potential for bioremediation, however, depends on the ability of the stream-bed microbial community to efficiently and completely degrade DCE and VC over a range of contaminant concentrations. The purposes of the studies reported here were to assess the potential for aerobic DCE and VC mineralization by stream-bed microorganisms and to evaluate the effects of DCE and VC concentrations on the apparent rates of aerobic mineralization. Bed-sediment microorganisms indigenous to a creek, where DCE-contaminated groundwater continuously discharges, demonstrated rapid mineralization of DCE and VC under aerobic conditions. Over 8 days, the recovery of [1,2-14C]DCE radioactivity as 14CO2 ranged from 17% to 100%, and the recovery of [1,2- 14C]VC radioactivity as 14CO2 ranged from 45% to 100%. Rates of DCE and VC mineralization increased significantly with increasing contaminant concentration, and the response of apparent mineralization rates to changes in DCE and VC concentrations was adequately described by Michaelis-Menten kinetics.Discharge of DCE and VC to an aerobic surface water system simultaneously represents a significant environmental concern and, potentially, a non-engineered opportunity for efficient contaminant bioremediation. The potential for bioremediation, however, depends on the ability of the stream-bed microbial community to efficiently and completely degrade DCE and VC over a range of contaminant concentrations. The purposes of the studies reported here were to assess the potential for aerobic DCE and VC mineralization by stream-bed microorganisms and to evaluate the effects of DCE and VC concentrations on the apparent rates of aerobic mineralization. Bed-sediment microorganisms indigenous to a creek, where DCE-contaminated groundwater

Appearance of circulating and tissue /sup 14/C-lipids after oral /sup 14/C-tripalmitate administration in the late pregnant rat

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

Argiles, J.; Herrera, E.

1989-02-01

Studies were performed to determine whether and/or how dietary lipids participate in maternal hypertriglyceridemia during late gestation in the rat. After oral administration of glycerol-tri(1-14C)-palmitate, total radioactivity in plasma increased more rapidly in 20-day pregnant rats than in either 19-day pregnant rats or virgin controls. At the peak of plasma radioactivity, four hours after the tracer was administered, most of the plasma label corresponded to 14C-lipids in triglyceride-rich lipoproteins (d less than 1.006), and when expressed per micromol of triglyceride, values were higher in pregnant than in virgin rats. The difference was less after 24 hours, although at this timemore » the level of 14C-lipids in d less than 1.006 lipoproteins was still higher in 20-day pregnant rats than in virgins. Tissue 14C-lipids, as expressed per gram of fresh weight, were similar in pregnant and virgin rats, but the values in mammary glands were much higher in the former group. Estimated recovery of administered radioactivity four hours after tracer in total white adipose tissue, mammary glands, and plasma lipids was higher in pregnant than in virgin rats. No difference was found between 20-day pregnant and virgin rats either in the label retained in the gastrointestinal tract or in that exhaled as 14C-CO2 during the first four hours following oral administration of 14C-tripalmitate. These findings plus the known maternal hyperphagia, indicate that in the rat at late pregnancy triglyceride intestinal absorption is unchanged or even enhanced and that dietary lipids actively contribute to both maternal hypertriglyceridemia and lipid uptake by the mammary gland.« less

Characterization of 14C in Swedish light water reactors.

PubMed

Magnusson, Asa; Aronsson, Per-Olof; Lundgren, Klas; Stenström, Kristina

2008-08-01

This paper presents the results of a 4-y investigation of 14C in different waste streams of both boiling water reactors (BWRs) and pressurized water reactors (PWRs). Due to the potential impact of 14C on human health, minimizing waste and releases from the nuclear power industry is of considerable interest. The experimental data and conclusions may be implemented to select appropriate waste management strategies and practices at reactor units and disposal facilities. Organic and inorganic 14C in spent ion exchange resins, process water systems, ejector off-gas and replaced steam generator tubes were analyzed using a recently developed extraction method. Separate analysis of the chemical species is of importance in order to model and predict the fate of 14C within process systems as well as in dose calculations for disposal facilities. By combining the results of this investigation with newly calculated production rates, mass balance assessments were made of the 14C originating from production in the coolant. Of the 14C formed in the coolant of BWRs, 0.6-0.8% was found to be accumulated in the ion exchange resins (core-specific production rate in the coolant of a 2,500 MWth BWR calculated to be 580 GBq GW(e)(-1) y(-1)). The corresponding value for PWRs was 6-10% (production rate in a 2,775 MWth PWR calculated to be 350 GBq GW(e)(-1) y(-1)). The 14C released with liquid discharges was found to be insignificant, constituting less than 0.5% of the production in the coolant. The stack releases, routinely measured at the power plants, were found to correspond to 60-155% of the calculated coolant production, with large variations between the BWR units.

14 CFR Appendix C to Part 151 - Appendix C to Part 151

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Appendix C to Part 151 C Appendix C to Part...) AIRPORTS FEDERAL AID TO AIRPORTS Pt. 151, App. C Appendix C to Part 151 There is set forth below an... Items 1. Maintenance-type work, including: (a) Seal coats. (b) Crack filling. (c) Resealing joints. (d...

14 CFR Appendix C to Part 25 - Appendix C to Part 25

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Appendix C to Part 25 C Appendix C to Part... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Pt. 25, App. C Appendix C to Part 25 Part I—Atmospheric....062 EC28SE91.063 (c) Takeoff maximum icing. The maximum intensity of atmospheric icing conditions for...

14 CFR Appendix C to Part 25 - Appendix C to Part 25

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Appendix C to Part 25 C Appendix C to Part... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Pt. 25, App. C Appendix C to Part 25 Part I—Atmospheric....062 EC28SE91.063 (c) Takeoff maximum icing. The maximum intensity of atmospheric icing conditions for...

14 CFR Appendix C to Part 25 - Appendix C to Part 25

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Appendix C to Part 25 C Appendix C to Part... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Pt. 25, App. C Appendix C to Part 25 Part I—Atmospheric....062 EC28SE91.063 (c) Takeoff maximum icing. The maximum intensity of atmospheric icing conditions for...

Low-level (submicromole) environmental 14C metrology

NASA Astrophysics Data System (ADS)

Currie, L. A.; Kessler, J. D.; Marolf, J. V.; McNichol, A. P.; Stuart, D. R.; Donoghue, J. C.; Donahue, D. J.; Burr, G. S.; Biddulph, D.

2000-10-01

Accelerator mass spectrometry (AMS) measurements of environmental 14C have been employed during the past decade at the several micromole level (tens of μg carbon), but advanced research in the atmospheric and marine sciences demands still higher (μg) sensitivity, an extreme example being the determination of 14C in elemental or "black" carbon (BC) at levels of 2-10 μg per kg of Greenland snow and ice (Currie et al., 1998). A fundamental limitation for 14C AMS is Poisson counting statistics, which sets in at about 1 μg modern-C. Using the small sample (25 μg) AMS target preparation facility at NOSAMS (Pearson et al., 1998), and the microsample combustion-dilution facility at NIST, we have demonstrated an intrinsic modern-C quantification limit ( mQ) of ca. 0.9 μg, based on a 1-parameter fit to the empirical AMS variance function. (For environmental 14C, the modern carbon quantification limit is defined as that mass ( mQ) corresponding to 10% relative standard deviation (rsd) for the fraction of modern carbon, σ( fM)/ fM.) Stringent control, required for quantitative dilution factors (DL), is achieved with the NIST on-line manometric/mass spectrometry facility that compensates also for unsuspected trace impurities from vigorous chemical processing (e.g., acid digestion). Our current combustion blank is trivial (mean: 0.16 ± 0.02 μg C, n=13) but lognormally distributed (dispersion [σ]: 0.07 ± 0.01 μg). An iterative numerical expression is introduced to assess the quantitative impacts of fossil and modern carbon blank components on mQ; and a new "clean chemistry" BC processing system is described for the minimization of such blanks. For the assay of soot carbon in Greenland snow/ice, the overall processing blank has been reduced from nearly 7 μg total carbon to less than 1 μg, and is undetectable for BC.

Bomb 14C time history recorded in two modern stalagmites — importance for soil organic matter dynamics and bomb 14C distribution over continents

NASA Astrophysics Data System (ADS)

Genty, D.; Vokal, B.; Obelic, B.; Massault, M.

1998-08-01

Carbon 14 activity measurements made by Accelerator Mass Spectrometry on two modern stalagmites from the Han-sur-Lesse cave (Belgium) and from the Postojna Cave (Slovenia) permit the construction of 14C activity ( a14C) time series over the last 50 years. A high precision chronology is given by annual laminae in the first stalagmite and by a specific mark (explosion in the Postojna Cave in 1944) in the second one. In both stalagmites, 14C activity increase due to nuclear tests in the atmosphere is remarkable. However, instead of a sharp peak like the one observed in the atmosphere around 1963-1964, the 14C activities of the stalagmite CaCO 3 show an abrupt increase, with an offset of 1-10 years, followed by a high activity plateau for the Han-sur-Lesse sample and a slight decrease for the Postojna sample. For both stalagmites, the variation of the a14C amplitude between pre- and post-bomb period is much lower than the atmospheric record, which demonstrates the damping effect of the soil carbon reservoir. We have modeled the CaCO 3 activities using fractionation processes between atmosphere CO 2, soil CO 2 and organic matter (OM), dissolved inorganic carbon and stalagmite CaCO 3. In both cases studied, the model and former soil studies suggest that CO 2 from soil organic matter (SOM) decomposition, which has a slow turnover (i.e. >1 y), is of major importance in winter, when the development of speleothem is the most important. Combined with the fact that 80-90% of the stalagmite carbon comes from soil CO 2, this produces a damping effect on the speleothem a14C. Consequently, the `geochemical time resolution', at least for speleothem carbon, is much lower than the structural resolution given by annual laminae alternations and is mainly controlled by soil carbon dynamics: a14C and δ 13C are smoothed over several years. Differences between the 14C time series of the Han-sur-Lesse and Postojna stalagmites are likely to be due to the double amount of precipitation in

Estimating 14C groundwater ages in a methanogenic aquifer

USGS Publications Warehouse

Aravena, Ramon; Wassenaar, Leonard I; Plummer, Niel

1995-01-01

This paper addresses the problem of 14C age dating of groundwaters in a confined regional aquifer affected by methanogenesis. Increasing CH4 concentrations along the groundwater flow system and 13C and 14C isotopic data for dissolved inorganic carbon, dissolved organic carbon, and CH4 clearly show the effect of methanogenesis on groundwater chemistry. Inverse reaction path modeling using NETPATH indicates the predominant geochemical reactions controlling the chemical evolution of groundwater in the aquifer are incongruent dissolution of dolomite, ion exchange, methanogenesis, and oxidation of sedimentary organic matter. Modeling of groundwater 14C ages using NETPATH indicates that a significant part of groundwater in the Alliston aquifer is less than 13,000 years old; however, older groundwater in the range of 15,000–23,000 years is also present in the aquifer. This paper demonstrates that 14C ages calculated using NETPATH, incorporating the effects of methanogenesis on the carbon pools, provide reasonable groundwater ages that were not possible by other isotopic methods.

29 CFR 1910.19 - Special provisions for air contaminants.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 5 2012-07-01 2012-07-01 false Special provisions for air contaminants. 1910.19 Section 1910.19 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Adoption and Extension of Established Federal...

29 CFR 1910.19 - Special provisions for air contaminants.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 5 2011-07-01 2011-07-01 false Special provisions for air contaminants. 1910.19 Section 1910.19 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Adoption and Extension of Established Federal...

Epidemiology of internal contamination with polonium-210 in the London incident, 2006.

PubMed

Fraser, G; Giraudon, I; Cohuet, S; Bishop, L; Maguire, H; Thomas, H L; Mandal, S; Anders, K; Sanchez-Padilla, E; Charlett, A; Evans, B; Gross, R

2012-02-01

More than 700 UK residents were tested for possible contamination with polonium-210 ((210)Po) following the alleged poisoning of Mr Alexander Litvinenko in London in November 2006. This paper describes the epidemiology of internal contamination with the radionuclide in this group. 11 locations in London had been identified as sufficiently environmentally contaminated with (210)Po to present a health risk to people associated with them. Public health consultant teams identified individuals at risk and offered 24-h urine testing for (210)Po excretion. Prevalence of internal contamination was estimated, and a retrospective cohort analysis was completed for each location. Overall 139 individuals (prevalence 0.19 (95% CI 0.13 to 0.27)) showed evidence of internal contamination with (210)Po, although none with uptakes likely to cause adverse health effects. Substantial prevalence was seen among specific hotel service staff, customers, staff and other users of a hotel bar, office and hospital staff, staff of one restaurant and residents of and visitors to the family home. Increased risks of contamination were seen for a hotel bar in association with occupational, behavioural and temporal factors. Occupational and guest exposure to contaminated areas of hotels were also associated with increased contamination risk. Nurses were more likely to become contaminated than other staff involved in direct patient care. Uptake of trace amounts of radionuclide in this incident was frequent. Occupational, behavioural and temporal gradients in contamination risk were mostly consistent with a priori site risk assessments. Utility of the investigation methods and findings for future accidental or deliberate environmental contamination incidents are discussed.

14C plateaus and global stratigraphic correlation during Termination IA

NASA Astrophysics Data System (ADS)

Sarnthein, M.; Grootes, P. M.; Kennett, J. P.; Nadeau, M.

2006-12-01

In search of a global 14C reference record for Termination IA, we analyzed three published 14C records with centennial-scale resolution, that provide independent evidence for calibrating the 14C time scale: (1) A sediment record from Cariaco Basin (ODP Site 1002) correlated to the U/Th-dated Hulu Cave record (Hughen et al., 2006), (2) a U/Th dated speleothem record from the Bahamas (Beck et al., 2001, 2006), and (3) a set of U/Th-dated coral ages (IntCal04 plus Fairbanks et al., 2005) that unfortunately lack data from 18-15 cal. ka. All these records exhibit significant changes in the slope of 14C vs. calendar ages, allowing us to define a suite of major and minor "14C plateaus" in each record, that in total occupy >70% of the 14C record between 19 and 14 cal. ka. Despite their different origin the three records are largely consistent. When dating resolution is sufficient, most plateaus show a characteristic internal structure incorporating 14C inversions, in particular near the onset of a plateau. Plateau boundary ages for the Cariaco record have a total range of uncertainty of 150-450 yr due to uncertainties with age calibration (Hughen et al., 2006), in addition to the range of dating resolution. During Termination IA, a period of dramatic climate change, these boundary ages should serve as datums for the global correlation of marine sediment records. Moreover, they are employed to deduce apparent paleoventil-ation ages and thus circulation patterns of surface and bottom water masses, as demonstrated for example from the northern Pacific and the Icelandic Sea.

(14)C, delta(13)C and total C content in soils around a Brazilian PWR nuclear power plant.

PubMed

Dias, Cíntia Melazo; Telles, Everaldo C; Santos, Roberto Ventura; Stenström, Kristina; Nícoli, Iêda Gomes; da Silveira Corrêa, Rosangela; Skog, Göran

2009-04-01

Nuclear power plants release (14)C during routine operation mainly as airborne gaseous effluents. Because of the long half-life (5730 years) and biological importance of this radionuclide (it is incorporated in plant tissue by photosynthesis), several countries have monitoring programs in order to quantify and control these emissions. This paper compares the activity of (14)C in soils taken within 1km from a Brazilian nuclear power plant with soils taken within a reference area located 50km away from the reactor site. Analyses of total carbon, delta(13)C and (137)Cs were also performed in order to understand the local soil dynamics. Except for one of the profiles, the isotopic composition of soil organic carbon reflected the actual forest vegetation present in both areas. The (137)Cs data show that the soils from the base of hills are probably allocthonous. The (14)C measurements showed that there is no accumulation due to the operation of the nuclear facility, although excess (14)C was found in the litter taken in the area close to power plant. This indicates that the anthropogenic signal observed in the litter fall has not been transferred yet to the soil. This study is part of an extensive research programme in which other samples including air, vegetation and gaseous effluents (taken in the vent stack of the Brazilian nuclear power reactors Angra I and II) were also analyzed. The present paper aimed to evaluate how (14)C emissions from the nuclear power plant are transferred and stored by soils present in the surroundings of the reactor site. This is the first study concerning anthropogenic (14)C in soils in Brazil.

Safety analysis of occupational exposure of healthcare workers to residual contaminations of cytotoxic drugs using FMECA security approach.

PubMed

Le, Laetitia Minh Mai; Reitter, Delphine; He, Sophie; Bonle, Franck Té; Launois, Amélie; Martinez, Diane; Prognon, Patrice; Caudron, Eric

2017-12-01

Handling cytotoxic drugs is associated with chemical contamination of workplace surfaces. The potential mutagenic, teratogenic and oncogenic properties of those drugs create a risk of occupational exposure for healthcare workers, from reception of starting materials to the preparation and administration of cytotoxic therapies. The Security Failure Mode Effects and Criticality Analysis (FMECA) was used as a proactive method to assess the risks involved in the chemotherapy compounding process. FMECA was carried out by a multidisciplinary team from 2011 to 2016. Potential failure modes of the process were identified based on the Risk Priority Number (RPN) that prioritizes corrective actions. Twenty-five potential failure modes were identified. Based on RPN results, the corrective actions plan was revised annually to reduce the risk of exposure and improve practices. Since 2011, 16 specific measures were implemented successively. In six years, a cumulative RPN reduction of 626 was observed, with a decrease from 912 to 286 (-69%) despite an increase of cytotoxic compounding activity of around 23.2%. In order to anticipate and prevent occupational exposure, FMECA is a valuable tool to identify, prioritize and eliminate potential failure modes for operators involved in the cytotoxic drug preparation process before the failures occur. Copyright © 2017 Elsevier B.V. All rights reserved.

Trace chemical contaminant generation rates for spacecraft contamination control system design

NASA Technical Reports Server (NTRS)

Perry, J. L.

1995-01-01

A spacecraft presents a unique design challenge with respect to providing a comfortable environment in which people can live and work. All aspects of the spacecraft environmental design including the size of the habitable volume, its temperature, relative humidity, and composition must be considered to ensure the comfort and health of the occupants. The crew members and the materials selected for outfitting the spacecraft play an integral part in designing a habitable spacecraft because material offgassing and human metabolism are the primary sources for continuous trace chemical contaminant generation onboard a spacecraft. Since these contamination sources cannot be completely eliminated, active control processes must be designed and deployed onboard the spacecraft to ensure an acceptably clean cabin atmosphere. Knowledge of the expected rates at which contaminants are generated is very important to the design of these processes. Data from past spacecraft missions and human contaminant production studies have been analyzed to provide this knowledge. The resulting compilation of contaminants and generation rates serve as a firm basis for past, present, and future contamination control system designs for space and aeronautics applications.

Indoor Chemistry: Materials, Ventilation Systems, and Occupant Activities

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

Morrison, G.C.; Corsi, R.L.; Destaillats, H.

2006-05-01

Chemical processes taking place in indoor environments can significantly alter the nature and concentrations of pollutants. Exposure to secondary contaminants generated in these reactions needs to be evaluated in association with many aspects of buildings to minimize their impact on occupant health and well-being. Focusing on indoor ozone chemistry, we describe alternatives for improving indoor air quality by controlling chemical changes related to building materials, ventilation systems, and occupant activities.

Capture reactions on C-14 in nonstandard big bang nucleosynthesis

NASA Technical Reports Server (NTRS)

Wiescher, Michael; Gorres, Joachim; Thielemann, Friedrich-Karl

1990-01-01

Nonstandard big bang nucleosynthesis leads to the production of C-14. The further reaction path depends on the depletion of C-14 by either photon, alpha, or neutron capture reactions. The nucleus C-14 is of particular importance in these scenarios because it forms a bottleneck for the production of heavier nuclei A greater than 14. The reaction rates of all three capture reactions at big bang conditions are discussed, and it is shown that the resulting reaction path, leading to the production of heavier elements, is dominated by the (p, gamma) and (n, gamma) rates, contrary to earlier suggestions.

Methylmercury oxidative degradation potentials in contaminated and pristine sediments of the Carson River, Nevada

USGS Publications Warehouse

Oremland, R.S.; Miller, L.G.; Dowdle, P.; Connell, T.; Barkay, T.

1995-01-01

Sediments from mercury-contaminated and uncontaminated reaches of the Carson River, Nevada, were assayed for sulfate reduction, methanogenesis, denitrification, and monomethylmercury (MeHg) degradation. Demethylation of [14C]MeHg was detected at all sites as indicated by the formation of 14CO2 and 14CH4. Oxidative demethylation was indicated by the formation of 14CO2 and was present at significant levels in all samples. Oxidized/reduced demethylation product ratios (i.e., 14CO2/14CH4 ratios) generally ranged from 4.0 in surface layers to as low as 0.5 at depth. Production of 14CO2 was most pronounced at sediment surfaces which were zones of active denitrification and sulfate reduction but was also significant within zones of methanogenesis. In a core taken from an uncontaminated site having a high proportion of oxidized, coarse-grain sediments, sulfate reduction and methanogenic activity levels were very low and 14CO2 accounted for 98% of the product formed from [14C]MeHg. There was no apparent relationship between the degree of mercury contamination of the sediments and the occurrence of oxidative demethylation. However, sediments from Fort Churchill, the most contaminated site, were most active in terms of demethylation potentials. Inhibition of sulfate reduction with molybdate resulted in significantly depressed oxidized/reduced demethylation product ratios, but overall demethylation rates of inhibited and uninhibited samples were comparable. Addition of sulfate to sediment slurries stimulated production of 14CO2 from [14C]MeHg, while 2-bromoethanesulfonic acid blocked production of 14CH4. These results reveal the importance of sulfate-reducing and methanogenic bacteria in oxidative demethylation of MeHg in anoxic environments.

Occupational Therapy in Medicaid Home and Community-Based Services Waivers

PubMed Central

VanPuymbrouck, Laura

2018-01-01

OBJECTIVE. Medicaid Home and Community-Based Services (HCBS) 1915(c) waivers are the largest provider of long-term services and supports for people with intellectual and developmental disabilities (IDDs). In this study, we explored how HCBS IDD waivers projected providing occupational therapy services in Fiscal Year (FY) 2015. METHOD. Medicaid HCBS IDD waivers across the nation gathered from the Centers for Medicare and Medicaid Services were qualitatively and quantitatively analyzed to determine how they projected providing occupational therapy services in terms of service expenditures and utilization. RESULTS. In FY 2015, $14.13 million of spending was projected for occupational therapy services of 7,500 participants. However, there was large heterogeneity across states and services in terms of total projected spending, spending per participant, and reimbursement rates. CONCLUSION. Comparisons across states strengthen the profession’s ability to assert the value of its services. These findings can help identify best practices and can advocate for the refinement of state occupational therapy programs. PMID:29426389

Impact of liming and drying municipal sewage sludge on the amount and availability of (14)C-acetyl sulfamethoxazole and (14)C-acetaminophen residues.

PubMed

Geng, Chunnu; Bergheaud, Valérie; Garnier, Patricia; Zhu, Yong-Guan; Haudin, Claire-Sophie

2016-01-01

Acetyl Sulfamethoxazole (AC-SMX) and acetaminophen (ACM) can be found in municipal sewage sludge, and their content and availability may be influenced by sludge treatments, such as drying and liming. A sludge similarly centrifuged with/without a flocculant was spiked with (14)C-labelled AC-SMX or ACM. Then, it was either limed (20% CaO) or/and dried under different laboratory conditions (1 week at ambient temperature; and 48 h at 40 or 80 °C). The total amount and distribution of the (14)C-compounds among several chemical fractions, based on the sludge floc definition, were assessed at the end of the treatments. All the (14)C-activity brought initially was recovered in the limed and/or dried sludges for AC-SMX but only between 44.4 and 84.9% for ACM, with the highest rate obtained for the limed sludge. Drying at 80 °C or liming increased the percentage of the sludge total organic carbon recovered in the extracts containing soluble extracellular polymeric substances (S-EPS) and the percentage of the total (14)C-activity extracted simultaneously. The non-extractable residues represented only 3.9-11.6% of the total (14)C-activity measured in the treated sludges for AC-SMX and 16.9-21.8% for ACM. The presence of AC-SMX and ACM residues in the treated sludges, after liming and drying under different conditions, was shown using some (14)C-labelled molecules. At this time scale and according to the extraction method selected, most of the (14)C-residues remained soluble and easily extractable for both compounds. This result implies that certain precautions should be taken when storing sludges before being spread on the field. Sludge piles, particularly the limed sludge, should be protected from rain to limit the production of lixiviates, which may contain residues of AC-SMX and ACM. Copyright © 2015 Elsevier Ltd. All rights reserved.

TNT transport and fate in contaminated soil

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

Comfort, S.D.; Shea, P.J.; Hundal, L.S.

1995-11-01

Past disposal practices at munitions production plants have contaminated terrestrial and aquatk ecosystems with 2,4,6-trinitrotoluene (TNT). We determined TNT transport, degradation, and long-term sorption characteristics in soil. Transport experiments were conducted with repacked, unsaturated soil columns containing uncontaminated soil or layers of contaminated and uncontaminated soil. Uncontaminated soil columns received multiple pore volumes (22-50) of a TNT-{sup 3}H{sub 2}O pulse, containing 70 or 6.3 mg TNT L{sup -1} at a constant pore water velocity. TNT breakthrough curves (BTCs) never reached initial solute pulse concentrations. Apex concentrations (C/C{sub o}) were between 0.6 and 0.8 for an initial pulse of 70 mgmore » TNT L{sup -1} and 0.2 to 0.3 for the 6.3 mg TNT L{sup -1} pulse. Earlier TNT breakthrough was observed at the higher pulse concentration. This mobility difference was predicted from the nonlinear adsorption isotherm determined for TNT sorption. In all experiments, a significant fraction of added TNT was recovered as amino degradates of TNT. Mass balance estimates indicated 81% of the added TNT was recovered (as TNT and amino degradates) from columns receiving the 70 mg TNT L{sup -1} pulse compared to 35% from columns receiving the 6.3 mg TNT L{sup -1} pulse. Most of the unaccountable TNT was hypothesized to be unextractable. This was supported by a 168-d sorption experiment, which found that within 14d, 80% of {sup 14}C activity (added as {sup 14}C-TNT) was adsorbed and roughly 40% unextractable. Our observations illustrate that TNT sorption and degradation are concentration-dependent and the assumptions of linear adsorption and adsorption-desorption singularity commonly used in transport modeling, may not be valid for predicting TNT transport in munitions-contaminated soils. 29 refs., 6 figs., 7 tabs.« less

14 CFR Appendix C to Part 43 - [Reserved

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false [Reserved] C Appendix C to Part 43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE, REBUILDING, AND ALTERATION Appendix C to Part 43 [Reserved] ...

14 CFR Appendix C to Part 43 - [Reserved

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false [Reserved] C Appendix C to Part 43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE, REBUILDING, AND ALTERATION Appendix C to Part 43 [Reserved] ...

14 CFR Appendix C to Part 43 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false [Reserved] C Appendix C to Part 43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE, REBUILDING, AND ALTERATION Appendix C to Part 43 [Reserved] ...

40 CFR 721.10007 - Alcohols, C12-14-secondary, ethoxylated propoxylated.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alcohols, C12-14-secondary... New Uses for Specific Chemical Substances § 721.10007 Alcohols, C12-14-secondary, ethoxylated... identified as alcohols, C12-14- secondary, ethoxylated propoxylated (PMN P-00-11; CAS No. 103331-86-8) is...

Chemical Characterization and Removal of C-14 from Irradiated Graphite-12010

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

Cleaver, James; McCrory, Shilo; Smith, Tara E.

2012-07-01

Quantities of irradiated graphite waste are expected to drastically increase, which indicates the need for a graphite waste management strategy. Of greatest concern for long-term disposal of irradiated graphite is carbon-14 (C-14), with a half-life of 5730 years. Study of irradiated graphite from nuclear reactors indicates C-14 is concentrated on the outer 5 mm of the graphite structure. The aim of the research described here is to identify the chemical form of C-14 in irradiated graphite and develop a practical method by which C-14 can be removed. Characterization of pre- and post-irradiation graphite was conducted to determine bond type, functionalmore » groups, location and concentration of C-14 and its precursors via the use of surface sensitive characterization techniques. Because most surface C-14 originates from neutron activation of nitrogen, an understanding of nitrogen bonding to graphite may lead to a greater understanding of the formation pathway of C-14. However, no single technique provides a complete picture. Therefore, a portfolio of techniques has been developed, with each technique providing another piece to the puzzle that is the chemical nature of the C-14. Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), and Raman Spectroscopy were used to evaluate the morphological features of graphite samples. The concentration, chemical composition, and bonding characteristics of C-14 and its precursors were determined through X-ray Photoelectron Spectroscopy (XPS), Time-of-Flight Secondary Ion Mass Spectrometry (SIMS), and Auger and Energy Dispersive X-ray Analysis Spectroscopy (EDX). High-surface-area graphite foam, POCOFoam{sup R}, was exposed to liquid nitrogen and irradiated. Characterization of this material has shown C-14 to C-12 ratios of 0.035. This information was used to optimize the thermal treatment of graphite. Thermal treatment of irradiated graphite as reported by Fachinger et al. (2007) uses naturally adsorbed oxygen complexes

40 CFR 721.644 - Amines, C12-14-tert-alkyl, sulfonates.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amines, C12-14-tert-alkyl, sulfonates... Substances § 721.644 Amines, C12-14-tert-alkyl, sulfonates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amines, C12-14-tert-alkyl, sulfonates (PMN...

40 CFR 721.644 - Amines, C12-14-tert-alkyl, sulfonates.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amines, C12-14-tert-alkyl, sulfonates... Substances § 721.644 Amines, C12-14-tert-alkyl, sulfonates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amines, C12-14-tert-alkyl, sulfonates (PMN...

29 CFR 1910.19 - Special provisions for air contaminants.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 5 2010-07-01 2010-07-01 false Special provisions for air contaminants. 1910.19 Section 1910.19 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... Standards § 1910.19 Special provisions for air contaminants. (a) Asbestos, tremolite, anthophyllite, and...

Historic binnacle of 14C/12C concentration in Mexico City

NASA Astrophysics Data System (ADS)

Flores, J. A.; Solís, C.; Huerta, A.; Ortiz, M. E.; Rodríguez-Ceja, M. G.; Villanueva, J.; Chávez, E.

The radiocarbon concentration is reduced in urban areas, generally due to high CO2 emissions derived from fossil fuels. In this paper, new Δ14C measurements in cellulose extracted from the growth rings of two trees over a 43-year period are presented. The first is in a zone with clean air (El Nayar, Durango, Mexico) and the second is from the Greater Mexico City area (Chapultepec). Data from El Nayar is consistent with that reported for Zone 2 of the Northern Hemisphere while that from the urban area shows a significant decrease in Δ14C. Our results are compared with data from other cities (Nagoya, Japan and Valladolid, Spain).

Extraction of in situ cosmogenic 14C from olivine

USGS Publications Warehouse

Pigati, J.S.; Lifton, N.A.; Timothy, Jull A.J.; Quade, Jay

2010-01-01

Chemical pretreatment and extraction techniques have been developed previously to extract in situ cosmogenic radiocarbon (in situ 14C) from quartz and carbonate. These minerals can be found in most environments on Earth, but are usually absent from mafic terrains. To fill this gap, we conducted numerous experiments aimed at extracting in situ 14C from olivine ((Fe,Mg)2SiO4). We were able to extract a stable and reproducible in situ 14C component from olivine using stepped heating and a lithium metaborate (LiBO2) flux, following treatment with dilute HNO3 over a variety of experimental conditions. However, measured concentrations for samples from the Tabernacle Hill basalt flow (17.3 ?? 0.3 ka4) in central Utah and the McCarty's basalt flow (3.0 ?? 0.2 ka) in western New Mexico were significantly lower than expected based on exposure of olivine in our samples to cosmic rays at each site. The source of the discrepancy is not clear. We speculate that in situ 14C atoms may not have been released from Mg-rich crystal lattices (the olivine composition at both sites was ~Fo65Fa35). Alternatively, a portion of the 14C atoms released from the olivine grains may have become trapped in synthetic spinel-like minerals that were created in the olivine-flux mixture during the extraction process, or were simply retained in the mixture itself. Regardless, the magnitude of the discrepancy appears to be inversely proportional to the Fe/(Fe+Mg) ratio of the olivine separates. If we apply a simple correction factor based on the chemical composition of the separates, then corrected in situ 14C concentrations are similar to theoretical values at both sites. At this time, we do not know if this agreement is fortuitous or real. Future research should include measurement of in situ 14C concentrations in olivine from known-age basalt flows with different chemical compositions (i.e. more Fe-rich) to determine if this correction is robust for all olivine-bearing rocks. ?? 2010 by the Arizona

Production of C-14 and neutrons in red giants

NASA Technical Reports Server (NTRS)

Cowan, J. J.; Rose, W. K.

1977-01-01

We have examined the effects of mixing various amounts of hydrogen-rich material into the intershell convective region of red giants undergoing helium shell flashes. We find that significant amounts of C-14 can be produced via the N-14(n, p)C-14 reaction. If substantial portions of this intershell region are mixed out into the envelopes of red giants, then C-14 may be detectable in evolved stars. We find a neutron flux many orders of magnitude above the flux required for the classical s-process, and thus an intermediate neutron process (i-process) may operate in evolved red giants. In all cases studied we find substantial enhancements of O-17. These mixing models offer a plausible explanation of the observations of enhanced O-17 in the carbon star IRC 10216. For certain physical conditions we find significant enhancements of N-15 in the intershell region.

Impacts of C-uptake by plants on the spatial distribution of 14C accumulated in vegetation around a nuclear facility-Application of a sophisticated land surface 14C model to the Rokkasho reprocessing plant, Japan.

PubMed

Ota, Masakazu; Katata, Genki; Nagai, Haruyasu; Terada, Hiroaki

2016-10-01

The impacts of carbon uptake by plants on the spatial distribution of radiocarbon ( 14 C) accumulated in vegetation around a nuclear facility were investigated by numerical simulations using a sophisticated land surface 14 C model (SOLVEG-II). In the simulation, SOLVEG-II was combined with a mesoscale meteorological model and an atmospheric dispersion model. The model combination was applied to simulate the transfer of 14 CO 2 and to assess the radiological impact of 14 C accumulation in rice grains during test operations of the Rokkasho reprocessing plant (RRP), Japan, in 2007. The calculated 14 C-specific activities in rice grains agreed with the observed activities in paddy fields around the RRP within a factor of four. The annual effective dose delivered from 14 C in the rice grain was estimated to be less than 0.7 μSv, only 0.07% of the annual effective dose limit of 1 mSv for the public. Numerical experiments of hypothetical continuous atmospheric 14 CO 2 release from the RRP showed that the 14 C-specific activities of rice plants at harvest differed from the annual mean activities in the air. The difference was attributed to seasonal variations in the atmospheric 14 CO 2 concentration and the growth of the rice plant. Accumulation of 14 C in the rice plant significantly increased when 14 CO 2 releases were limited during daytime hours, compared with the results observed during the nighttime. These results indicated that plant growth stages and diurnal photosynthesis should be considered in predictions of the ingestion dose of 14 C for long-term chronic releases and short-term diurnal releases of 14 CO 2 , respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Flight measurement of molecular contaminant deposition

NASA Astrophysics Data System (ADS)

Hall, David F.

1994-10-01

A spacecraft was instrumented with four temperature controlled quartz crystal microbalance (TQCM) contamination detectors. One TQCM, located inside the vehicle, recorded contaminant deposition that was orders of magnitude higher than did the three TQCMs located in various positions outside the vehicle. The deposition rate on the interior TQCM varied with the temperatures of interior spacecraft cavity surfaces. In particular, there is clear evidence of condensation on these surfaces and re-evaporation from these surfaces by previously outgassed contaminant molecules. The e-folding time constants of the deposition on two of the exterior TQCMs held at -50 degree(s)C are approximately 1.4 years, with extrapolated final equivalent thickness of the deposition in the 20 - 25 nm (200 - 250 angstroms) range. The third exterior TQCM, which has a significant field of view of a segmented thermal blanket, collected contamination at a greater rate. The data enable the ranking of the several contamination transport mechanisms at work and the drawing of general recommendations for spacecraft design.

17 CFR 240.14c-1 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... director or officer of the registrant or any of its parents or subsidiaries. (b) Employee benefit plan. For purposes of § 240.14c-7, the term “employee benefit plan” means any purchase, savings, option, bonus..., trustees or officers. (c) Entity that exercises fiduciary powers. The term “entity that exercises fiduciary...

The economic burden of lung cancer and mesothelioma due to occupational and para-occupational asbestos exposure

PubMed Central

Tompa, Emile; Kalcevich, Christina; McLeod, Chris; Lebeau, Martin; Song, Chaojie; McLeod, Kim; Kim, Joanne; Demers, Paul A

2017-01-01

Objectives To estimate the economic burden of lung cancer and mesothelioma due to occupational and para-occupational asbestos exposure in Canada. Methods We estimate the lifetime cost of newly diagnosed lung cancer and mesothelioma cases associated with occupational and para-occupational asbestos exposure for calendar year 2011 based on the societal perspective. The key cost components considered are healthcare costs, productivity and output costs, and quality of life costs. Results There were 427 cases of newly diagnosed mesothelioma cases and 1904 lung cancer cases attributable to asbestos exposure in 2011 for a total of 2331 cases. Our estimate of the economic burden is $C831 million in direct and indirect costs for newly identified cases of mesothelioma and lung cancer and $C1.5 billion in quality of life costs based on a value of $C100 000 per quality-adjusted life year. This amounts to $C356 429 and $C652 369 per case, respectively. Conclusions The economic burden of lung cancer and mesothelioma associated with occupational and para-occupational asbestos exposure is substantial. The estimate identified is for 2331 newly diagnosed, occupational and para-occupational exposure cases in 2011, so it is only a portion of the burden of existing cases in that year. Our findings provide important information for policy decision makers for priority setting, in particular the merits of banning the mining of asbestos and use of products containing asbestos in countries where they are still allowed and also the merits of asbestos removal in older buildings with asbestos insulation. PMID:28756416

Carbon and 14C distribution in tropical and subtropical agricultural soils

NASA Astrophysics Data System (ADS)

Prastowo, Erwin; Grootes, Pieter; Nadeau, Marie

2016-04-01

Paddy soil management affects, through the alternating anoxic and oxic conditions it creates, the transport and stabilisation of soil organic matter (SOM). Irrigation water may percolate more organic materials - dissolved (DOM) and colloidal - into the subsoil during anoxic conditions. Yet a developed ploughpan tends to prevent C from going deeper in the subsoil and partly decouple C distribution in top and sub soil. We investigate the influence of different soil type and environment. We observed the C and 14C distribution in paddy and non-paddy soil profiles in three different soil types from four different climatic regions of tropical Indonesia, and subtropical China. Locations were Sukabumi (Andosol, ca. 850 m a.s.l), Bogor (clayey Alisol, ca. 240 m a.s.l), and Ngawi (Vertisol, ca. 70 m a.s.l) in Jawa, Indonesia, and Cixi (Alisol(sandy), ca. 4 - 6 m a.s.l) in Zhejiang Province, China. We compared rice paddies with selected neighbouring non-paddy fields and employed AMS 14C as a tool to study C dynamics from bulk, alkali soluble-humic, and insoluble humin samples, and macrofossils (plant remains, charcoal). Our data suggest that vegetation type determines the quantity and quality of biomass introduced as litter and root material in top and subsoil, and thus contributes to the soil C content and profile, which fits the 14C signal distribution, as well as 13C in Ngawi with C4 sugar cane as upland crop. 14C concentrations for the mobile humic acid fraction were generally higher than for bulk samples from the same depth, except when recent plant and root debris led to high 14C levels in near-surface samples. The difference in sampling, - averaged layer for bulk sample and 1-cm layer thickness for point sample - shows gradients in C and 14C across the layers, which could be a reason for discrepancies between the two. High 14C concentrations - in Andosol Sukabumi up to 111 pMC - exceed the atmospheric 14CO2concentration in the sampling year in 2012 (˜ 103 pMC) and

40 CFR 721.642 - Amines, N-(C14-18 and C16-16 unsaturated alkyl)] dipropylene-tri-, tripropylenetetra-, and...

Code of Federal Regulations, 2010 CFR

2010-07-01

... substances amines, N-(C14-18 and C16-18 unsaturated alkyl)] dipropylenetri-, (PMN P-94-1244... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amines, N-(C14-18 and C16-16... Amines, N-(C14-18 and C16-16 unsaturated alkyl)] dipropylene-tri-, tripropylenetetra-, and...

Monitoring flux through the oxidative pentose phosphate pathway using [1-14C]gluconate.

PubMed

Garlick, Andrew P; Moore, Catherine; Kruger, Nicholas J

2002-12-01

The aim of this work was to examine the metabolism of exogenous gluconate by a 4-day-old cell suspension culture of Arabidopsis thaliana (L.) Heynh. Release of (14)CO(2) from [1-(14)C]gluconate was dependent on the concentration in the medium and could be resolved into a substrate-saturable component (apparent K(m) of approximately 0.4 mM) and an unsaturable component. At an external concentration of 0.3 mM, the rate of decarboxylation of applied gluconate was 0.2% of the rate of oxygen consumption by the cells. There was no effect of 0.3 mM gluconate on the rate of oxygen consumption, or on the rate of (14)CO(2) release from either [1-(14)C]glucose or [6-(14)C]glucose by the culture. The following observations argue that gluconate taken up by the cells is metabolised by direct phosphorylation to 6-phosphogluconate and subsequent decarboxylation through 6-phosphogluconate dehydrogenase. First, more than 95% of the label released from [1-(14)C]gluconate during metabolism by the cell culture was recovered as (14)CO(2). Secondly, inhibition of the oxidative pentose phosphate pathway (OPPP) by treatment with 6-aminonicotinamide preferentially inhibited release of (14)CO(2) from [1-(14)C]gluconate relative to that from [1-(14)C]glucose. Thirdly, perturbation of glucose metabolism by glucosamine did not affect (14)CO(2) from [1-(14)C]gluconate. Fourth, stimulation of the OPPP by phenazine methosulphate stimulated release of (14)CO(2) from [1-(14)C]gluconate to a far greater extent than that from [1-(14)C]glucose. It is proposed that measurement of (14)CO(2) from [1-(14)C]gluconate provides a simple and sensitive technique for monitoring flux through the OPPP pathway in plants.

Dietary Differences in Male Workers among Smaller Occupational Groups within Large Occupational Categories: Findings from the Japan Environment and Children's Study (JECS).

PubMed

Tanaka, Rie; Tsuji, Mayumi; Senju, Ayako; Kusuhara, Koichi; Kawamoto, Toshihiro

2018-05-11

Studies examining workers' diet according to smaller occupational groups within "large occupational categories" are sparse. The aim of this study was to examine the potential differences in workers' diets based on the classification of workers into smaller occupational groups that comprise "large occupational categories". The subjects of this study were working fathers who had participated in the Japan Environment and Children's Study (N = 38,656). Energy and nutrient intake were calculated based on data collected from the Food Frequency Questionnaire. Occupations were classified according to the Japanese Standard Occupational Classification. Logistic regression analyses were performed to examine the adherence to current dietary recommendations within smaller occupational groups. In particular, significant differences were observed among the categorical groups of "professional and engineering workers", "service workers", and "agricultural, forestry, and fishery workers". In "professional and engineering workers", teachers showed higher odds of adherence to calcium intake recommendations compared with nurses (OR, 2.54; 95% CI, 2.02⁻3.14; p < 0.001). In "agricultural, forestry, and fishery workers", agriculture workers showed higher odds of adherence to calcium (OR, 2.15; 95% CI, 1.46⁻3.15; p < 0.001) and vitamin C (OR 1.90, 95% CI 1.31⁻2.74, p = 0.001) intake recommendations compared with forestry and fishery workers. These findings may be beneficial from a research perspective as well as in the development of more effective techniques to improve workers' diet and health.

[Editorial] Environmental and occupational risk factors associated with different pathological conditions.

PubMed

Signorelli, Salvatore Santo; Ferrante, Margherita

2017-05-01

A wide body of evidence indicates that environmental and occupational risk factors are associated with the development of pathological disorders. The pathogenic role of many environmental pollutants or occupational contaminants is already known and has been extensively investigated. However, the molecular mechanisms of action and the pathogenic effects of many substances remain unknown. Therefore, there is a need to better investigate the role of new environmental and occupational risk factors that may cause the development of several diseases.

Detecting human presence at the border of the Northeastern Italian Pre-Alps. 14C dating at Rio Secco cave as expression of the first Gravettian and the late mousterian in the Northern Adriatic Region.

PubMed

Talamo, Sahra; Peresani, Marco; Romandini, Matteo; Duches, Rossella; Jéquier, Camille; Nannini, Nicola; Pastoors, Andreas; Picin, Andrea; Vaquero, Manuel; Weniger, Gerd-Christian; Hublin, Jean-Jacques

2014-01-01

In the northern Adriatic regions, which include the Venetian region and the Dalmatian coast, late Neanderthal settlements are recorded in few sites and even more ephemeral are remains of the Mid-Upper Palaeolithic occupations. A contribution to reconstruct the human presence during this time range has been produced from a recently investigated cave, Rio Secco, located in the northern Adriatic region at the foot of the Carnic Pre-Alps. Chronometric data make Rio Secco a key site in the context of recording occupation by late Neanderthals and regarding the diffusion of the Mid-Upper Palaeolithic culture in a particular district at the border of the alpine region. As for the Gravettian, its diffusion in Italy is a subject of on-going research and the aim of this paper is to provide new information on the timing of this process in Italy. In the southern end of the Peninsula the first occupation dates to around 28,000 14C BP, whereas our results on Gravettian layer range from 29,390 to 28,995 14C years BP. At the present state of knowledge, the emergence of the Gravettian in eastern Italy is contemporaneous with several sites in Central Europe and the chronological dates support the hypothesis that the Swabian Gravettian probably dispersed from eastern Austria.

Influence of processing on the microstructure and mechanical properties of 14YWT

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

Hoelzer, D. T.; Unocic, K. A.; Sokolov, Mikhail A.

2016-04-25

The investigation of the mechanical alloying (MA) conditions for producing the advanced oxide dispersion strengthened (ODS) 14YWT ferritic alloy led to significant improvements in balancing the strength, ductility and fracture toughness properties while still maintaining the salient microstructural features consisting of ultra-fine grains and high concentration of Y-, Ti- and O-enriched nanoclusters. The implemented changes to the processing conditions included reducing the contamination of the powder during ball milling, applying a pre-extrusion annealing treatment on the ball milled powder and exploring different extrusion temperatures at 850 C (SM170 heat), 1000 C (SM185) and 1150 C (SM200). The microstructural studies ofmore » the three 14YWT heats showed similarities in the dispersion of nanoclusters and sub-micron size grains, indicating the microstructure was insensitive to the different extrusion conditions. Compared to past 14YWT heats, the three new heats showed lower strength, but higher ductility levels between 25 and 800 C and significantly higher fracture toughness values between 25 C and 700 C. The lower contamination levels of O, C and N achieved with improved ball milling conditions plus the slightly larger grain size were identified as important factors for improving the balance in mechanical properties of the three heats of 14YWT.« less

Rapid increase in cosmogenic 14C in AD 775 measured in New Zealand kauri trees indicates short-lived increase in 14C production spanning both hemispheres

NASA Astrophysics Data System (ADS)

Güttler, D.; Adolphi, F.; Beer, J.; Bleicher, N.; Boswijk, G.; Christl, M.; Hogg, A.; Palmer, J.; Vockenhuber, C.; Wacker, L.; Wunder, J.

2015-02-01

In 2012, Miyake et al. reported a sudden and strong increase of the atmospheric radiocarbon (14C) content in Japanese cedar trees of 1.2% between AD 774 and 775. While their findings were quickly confirmed by a German oak chronology for the Northern Hemisphere (NH), the question remained if the effect was seen in both hemispheres. Here we present the first annually resolved Southern Hemisphere (SH) 14C record spanning the interval AD 760-787, using New Zealand kauri (Agathis australis) chronology wood. An almost identical distinct increase compared to Northern Hemisphere data was observed, suggesting a cosmic event with globally uniform impact as a potential cause for the increase. Deploying a carbon cycle box model a worldwide averaged net 14C production of 2.2 ×108 14C atoms cm-2 was estimated, which is 3.7 times higher than the average annual 14C production. The immediate appearance of the event in tree rings on both hemispheres suggests a short duration event of significantly less than 1 yr.

Prompt remediation of water intrusion corrects the resultant mold contamination in a home.

PubMed

Rockwell, William

2005-01-01

More patients are turning to their allergists with symptoms compatible with allergic rhinitis, allergic sinusitis, and/or bronchial asthma after exposure to mold-contaminated indoor environments. These patients often seek guidance from their allergists in the remediation of the contaminated home or office. The aim of this study was to determine baseline mold spore counts for noncontaminated homes and report a successful mold remediation in one mold-contaminated home. Indoor air quality was tested using volumetric spore counts in 50 homes where homeowners reported no mold-related health problems and in one mold-contaminated home that was remediated. The health of the occupant of the mold-contaminated home also was assessed. Indoor volumetric mold spore counts ranged from 300 to 1200 spores/m3 in the baseline homes. For the successful remediation, the mold counts started at 300 spores/m3, increased to 2800 spores/m3 at the height of the mold contamination, and then fell to 800 spores/m3 after remediation. The occupant's allergic symptoms ceased on complete remediation of the home. Indoor volumetric mold counts taken with the Allergenco MK-3 can reveal a potential indoor mold contamination, with counts above 1000 spores/m3 suggesting indoor mold contamination. Once the presence of indoor mold growth is found, a prompt and thorough remediation can bring mold levels back to near-baseline level and minimize negative health effects for occupants.

Chandra Contaminant Migration Model

NASA Technical Reports Server (NTRS)

Swartz, Douglas A.; O'Dell, Steve L.

2014-01-01

High volatility cleans OBFs and low volatility produces a high build-up at OBF centers; only a narrow (factor of 2 or less) volatility range produces the observed spatial pattern. Simulations predict less accumulation above outer S-array CCDs; this may explain, in part, gratings/imaging C/MnL discrepancies. Simulations produce a change in center accumulation due solely to DH heater ON/OFF temperature change; but a 2nd contaminant and perhaps a change in source rate is also required. Emissivity E may depend on thickness; another model parameter. Additional physics, e.g., surface migration, is not warranted at this time. At t approx. 14 yrs, model produced 0.22 grams of contaminant, 0.085 grams remaining within ACIS cavity; 7 percent (6mg) on OBFs.

Temperature-Dependent Survival of Hepatitis A Virus during Storage of Contaminated Onions

PubMed Central

Sun, Y.; Laird, D. T.

2012-01-01

Pre- or postharvest contamination of green onions by hepatitis A virus (HAV) has been linked to large numbers of food-borne illnesses. Understanding HAV survival in onions would assist in projecting the risk of the disease associated with their consumption. This study defined HAV inactivation rates in contaminated green onions contained in air-permeable, moisture-retaining high-density polyethylene packages that were stored at 3, 10, 14, 20, 21, 22, and 23°C. A protocol was established to recover HAV from whole green onions, with 31% as the average recovery by infectivity assay. Viruses in eluates were primarily analyzed by a 6-well plaque assay on FRhK-4 cells. Eight storage trials, including two trials at 3°C, were conducted, with 3 to 7 onion samples per sampling and 4 to 7 samplings per trial. Linear regression correlation (r2 = 0.80 to 0.98) was observed between HAV survival and storage time for each of the 8 trials, held at specific temperatures. Increases in the storage temperature resulted in greater HAV inactivation rates, e.g., a reduction of 0.033 log PFU/day at 3.4 ± 0.3°C versus 0.185 log PFU/day at 23.4 ± 0.7°C. Thus, decimal reduction time (D) values of 30, 14, 11, and 5 days, respectively, were obtained for HAV in onions stored at 3, 10, 14, and 23°C. Further regression analysis determined that 1 degree Celsius increase would increase inactivation of HAV by 0.007 log PFU/day in onions (r2 = 0.97). The data suggest that natural degradation of HAV in contaminated fresh produce is minimal and that a preventive strategy is critical to produce safety. The results are useful in predicting the risks associated with HAV contamination in fresh produce. PMID:22544253

Preparation of paper scintillator for detecting 3H contaminant.

PubMed

Miyoshi, Hirokazu; Ikeda, Toshiji

2013-09-01

Liquid scintillator (LS)-encapsulated silica was prepared by the sol-gel method and then was added dropwise onto a wipe paper to form a paper scintillator. First, the efficiencies of wipe were determined for both the paper scintillator and the wipe paper using a liquid scintillation counter (LSC). The efficiencies of wipe using the paper scintillator and the wipe paper were 88 and 36 %, respectively. The detection efficiencies were 5.5 % for the paper scintillator, 46 % for the wipe paper using an LS and 0.08 % for the (3)H/(14)C survey meter, respectively, compared with that of a melt-on scintillator of 47 %. Second, an (3)H contaminant on the paper scintillator was successfully detected using a photomultiplier without an LSC or an (3)H/(14)C survey meter. Finally, the paper scintillator was able to detect beta rays of the (3)H contaminant easily without an LS.

Hydrogeological Analysis and Groundwater Flow for C-Reactor Area with Contaminant Transport for C-Reactor Seepage Basins (CRSB) and C-Area Burning/Rubble Pit (CBRP)

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

FLACH, GREGORYP.

1999-12-01

A groundwater flow model encompassing approximately 4 mi2 within C Reactor area has been developed. The objectives and goals of the C Reactor Area groundwater model are to: Provide a common hydrogeologic and groundwater flow modeling framework for C Area that can be easily updated as additional field data is collected from waste site investigations. Provide a baseline groundwater flow model for use in subsequent flow and transport simulations for remedial/feasibility studies for C Area waste sites. Provide baseline transport simulations for CBRP and CRSB that reconstruct historical contaminant distributions and simulate future plume migration from each waste unit. Providemore » a working groundwater flow model for particle tracking and analysis to guide subsequent field characterization activities. The model incorporates historical and current field characterization data up through spring 1999. The model simulates groundwater flow within the area bounded to the west and north by Fourmile Branch, to the south by Caster Creek, and to the east by a line between Fourmile Branch and the headwaters of Caster Creek. Vertically the model extends from ground surface to the top of the Gordon aquifer. The chosen areal grid is 14,600 by 13,200 feet with a resolution of 200 feet. The model accurately reproduces groundwater flow directions from the CBRP and CRSB, and matches targets for hydraulic head, recharge and baseflow within calibration goals. The hydrogeologic model reflects aquifer heterogeneity as derived from CPT lithologic data.« less

Carbon-14 Specific Activity Model Validation for Biota in Wetland Environments

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

Yankovich, T.L.; Sharp, K.J.; Benz, M.L.

2008-01-15

In many cases, contaminants, such as radionuclides, can show highly localized spatial distributions in natural systems. Therefore, a key question for environmental assessment and monitoring becomes, how can these localized distributions of contaminants in the environment lead to organism exposure, and ultimately, the potential for effects to receptor biota? To address this question, an important first step is to conduct field surveys at sites of interest to map out the spatial distribution and extent of contaminants in areas that are being occupied and utilized by resident receptor biota. Work can then be conducted to establish predictive relationships between contaminant concentrationsmore » in biota tissues and those in environmental media with which biota interact, to gain an understanding of how representative ambient contaminant concentrations are of biota exposure. The objectives of this study were: - To conduct a field survey in a wetland ecosystem to characterize the spatial distribution of carbon- 14 ({sup 14}C), a radionuclide with dynamics in natural systems that can be described using a specific activity model; and - To determine whether {sup 14}C concentrations in environmental media reflect those measured in tissues of resident flora and fauna. A detailed field campaign was carried out in summer 2001 to characterize the spatial distribution and areal coverage of {sup 14}C in Duke Swamp, a wetland ecosystem on Atomic Energy of Canada Limited (AECL)'s Chalk River Laboratories (CRL) site that receives {sup 14}C through releases from an up-gradient Waste Management Area (WMA), primarily through groundwater influx. Sampling of surface vegetation (dominantly comprised of Sphagnum moss) was conducted at a total of 69 locations, with complementary sampling of air, soil, fungi, aerial insects, ground-dwelling insects, amphibians, small mammals and snakes being carried out at a subset of five locations with varying {sup 14}C concentrations. Concentrations of

Measurement of surface contamination by certain antineoplastic drugs using high-performance liquid chromatography: applications in occupational hygiene investigations in hospital environments.

PubMed

Rubino, F M; Floridia, L; Pietropaolo, A M; Tavazzani, M; Colombi, A

1999-01-01

Within the context of continuing interest in occupational hygiene of hospitals as workplaces, the authors report the results of a preliminary study on surface contamination by certain antineoplastic drugs (ANDs), recently performed in eight cancer departments of two large general hospitals in Milan, Italy. Since reliable quantitative information on the exposure levels to individual drugs is mandatory to establish a strong interpretative framework for correctly assessing the health risks associated with manipulation of ANDs and rationally advise intervention priorities for exposure abatement, two automated analytical methods were set up using reverse-phase high-performance liquid chromatography for the measurement of contamination by 1) methotrexate (MTX) and 2) the three most important nucleoside analogue antineoplastic drugs (5-fluorouracil 5FU, Cytarabin CYA, Gemcytabin GCA) on surfaces such as those of preparation hoods and work-benches in the pharmacies of cancer wards. The methods are characterized by short analysis time (7 min) under isocratic conditions, by the use of a mobile phase with a minimal content of organic solvent and by high sensitivity, adequate to detect surface contamination in the 5-10 micrograms/m2 range. To exemplify the performance of the analytical methods in the assessment of contamination levels from the target analyte ANDs, data are reported on the contamination levels measured on various surfaces (such as on handles, floor surfaces and window panes, even far from the preparation hood). Analyte concentrations corresponding to 0.8-1.5 micrograms of 5FU were measured on telephones, 0.85-28 micrograms/m2 of CYA were measured on tables, 1.2-1150 micrograms/m2 of GCA on furniture and floors. Spillage fractions between 1-5% of the used ANDs (daily use 5FU 7-13 g; CYA 0.1-7.1 g; GCA 0.2-5 g) were measured on the disposable polythene-backed paper cover sheet of the preparation hood.

Occupational therapy practice in emergency care: Occupational therapists' perspectives.

PubMed

Spang, Lisa; Holmqvist, Kajsa

2015-01-01

Emergency care takes place in a complex work environment that is characterized by critically ill patients, short hospital stays, and a wide variety of different healthcare professionals. Studies of occupational therapists' (OTs) experiences of working within emergency care have shown that they often experience difficulties in explaining the essence of occupational therapy and have to justify their approaches. Much effort has been made in Sweden to help OTs dispel the notion that occupational therapy is difficult to explain, and the aim of this study was to describe how Swedish OTs perceive their work in emergency care. A qualitative descriptive approach was taken, and 14 interviews were conducted with OTs working in emergency care. Qualitative content analysis was used to analyse the data. The overall theme that emerged was "Feeling established through deliberate occupation-based work". The underlying categories showed different strategies used by the OTs to provide occupational therapy in an emergency care context. Deliberate strategies were used to demonstrate the effectiveness of occupational therapy and its approaches to patients and other health care professionals, and this resulted in the OTs feeling both established and needed. Unlike the OTs in previous studies, the Swedish OTs experienced no difficulties in explaining occupational therapy and could make convincing arguments for their interventions. Parallel to their clinical work, the OTs worked with on-going development to find ways to improve their approaches. In summary, these Swedish OTs seem to have been provided with a professional language and the knowledge required to establish themselves in an emergency care setting.

Pion contamination in the MICE muon beam

NASA Astrophysics Data System (ADS)

Adams, D.; Alekou, A.; Apollonio, M.; Asfandiyarov, R.; Barber, G.; Barclay, P.; de Bari, A.; Bayes, R.; Bayliss, V.; Bertoni, R.; Blackmore, V. J.; Blondel, A.; Blot, S.; Bogomilov, M.; Bonesini, M.; Booth, C. N.; Bowring, D.; Boyd, S.; Brashaw, T. W.; Bravar, U.; Bross, A. D.; Capponi, M.; Carlisle, T.; Cecchet, G.; Charnley, C.; Chignoli, F.; Cline, D.; Cobb, J. H.; Colling, G.; Collomb, N.; Coney, L.; Cooke, P.; Courthold, M.; Cremaldi, L. M.; DeMello, A.; Dick, A.; Dobbs, A.; Dornan, P.; Drews, M.; Drielsma, F.; Filthaut, F.; Fitzpatrick, T.; Franchini, P.; Francis, V.; Fry, L.; Gallagher, A.; Gamet, R.; Gardener, R.; Gourlay, S.; Grant, A.; Greis, J. R.; Griffiths, S.; Hanlet, P.; Hansen, O. M.; Hanson, G. G.; Hart, T. L.; Hartnett, T.; Hayler, T.; Heidt, C.; Hills, M.; Hodgson, P.; Hunt, C.; Iaciofano, A.; Ishimoto, S.; Kafka, G.; Kaplan, D. M.; Karadzhov, Y.; Kim, Y. K.; Kuno, Y.; Kyberd, P.; Lagrange, J.-B.; Langlands, J.; Lau, W.; Leonova, M.; Li, D.; Lintern, A.; Littlefield, M.; Long, K.; Luo, T.; Macwaters, C.; Martlew, B.; Martyniak, J.; Mazza, R.; Middleton, S.; Moretti, A.; Moss, A.; Muir, A.; Mullacrane, I.; Nebrensky, J. J.; Neuffer, D.; Nichols, A.; Nicholson, R.; Nugent, J. C.; Oates, A.; Onel, Y.; Orestano, D.; Overton, E.; Owens, P.; Palladino, V.; Pasternak, J.; Pastore, F.; Pidcott, C.; Popovic, M.; Preece, R.; Prestemon, S.; Rajaram, D.; Ramberger, S.; Rayner, M. A.; Ricciardi, S.; Roberts, T. J.; Robinson, M.; Rogers, C.; Ronald, K.; Rubinov, P.; Rucinski, P.; Sakamato, H.; Sanders, D. A.; Santos, E.; Savidge, T.; Smith, P. J.; Snopok, P.; Soler, F. J. P.; Speirs, D.; Stanley, T.; Stokes, G.; Summers, D. J.; Tarrant, J.; Taylor, I.; Tortora, L.; Torun, Y.; Tsenov, R.; Tunnell, C. D.; Uchida, M. A.; Vankova-Kirilova, G.; Virostek, S.; Vretenar, M.; Warburton, P.; Watson, S.; White, C.; Whyte, C. G.; Wilson, A.; Winter, M.; Yang, X.; Young, A.; Zisman, M.

2016-03-01

The international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240 MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less than ~1% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is fπ < 1.4% at 90% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.

Pion contamination in the MICE muon beam

DOE PAGES

Adams, D.; Alekou, A.; Apollonio, M.; ...

2016-03-01

Here, the international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240\\,MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less thanmore » $$\\sim$$1% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is $$f_\\pi < 1.4\\%$$ at 90% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.« less

14 CFR Appendix C to Part 125 - Ice Protection

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Ice Protection C Appendix C to Part 125... OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Pt. 125, App. C Appendix C to Part 125... conditions as described in appendix C of part 25 of this chapter. (c) Compliance with all or portions of this...

The economic burden of lung cancer and mesothelioma due to occupational and para-occupational asbestos exposure.

PubMed

Tompa, Emile; Kalcevich, Christina; McLeod, Chris; Lebeau, Martin; Song, Chaojie; McLeod, Kim; Kim, Joanne; Demers, Paul A

2017-11-01

To estimate the economic burden of lung cancer and mesothelioma due to occupational and para-occupational asbestos exposure in Canada. We estimate the lifetime cost of newly diagnosed lung cancer and mesothelioma cases associated with occupational and para-occupational asbestos exposure for calendar year 2011 based on the societal perspective. The key cost components considered are healthcare costs, productivity and output costs, and quality of life costs. There were 427 cases of newly diagnosed mesothelioma cases and 1904 lung cancer cases attributable to asbestos exposure in 2011 for a total of 2331 cases. Our estimate of the economic burden is $C831 million in direct and indirect costs for newly identified cases of mesothelioma and lung cancer and $C1.5 billion in quality of life costs based on a value of $C100 000 per quality-adjusted life year. This amounts to $C356 429 and $C652 369 per case, respectively. The economic burden of lung cancer and mesothelioma associated with occupational and para-occupational asbestos exposure is substantial. The estimate identified is for 2331 newly diagnosed, occupational and para-occupational exposure cases in 2011, so it is only a portion of the burden of existing cases in that year. Our findings provide important information for policy decision makers for priority setting, in particular the merits of banning the mining of asbestos and use of products containing asbestos in countries where they are still allowed and also the merits of asbestos removal in older buildings with asbestos insulation. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The George C. Marshall Space Flight Center's 14 X 14-Inch Trisonic Wind Tunnel: A Historical Perspective

NASA Technical Reports Server (NTRS)

Springer, A.

1994-01-01

A history of the National Aeronautics and Space Administration (NASA) George C. Marshall Space Flight Center's (MSFC) 14 x 14-Inch Trisonic Wind Tunnel is presented. Its early and continuing role in the United States space program is shown through highlights of the tunnel's history and the major programs tested in the tunnel over the past 40 years. The 14-Inch Tunnel has its beginning with the Army in the late 1950's under the Army Ballistic Missile Agency (ABMA). Such programs as the Redstone, Jupiter, Pershing, and early Saturn were tested in the 14-Inch Tunnel in the late 1950's. America's first launch vehicle, the Jupiter C, was designed and developed using the 14-Inch Wind Tunnel. Under NASA, the 14-Inch Wind Tunnel has made large contributions to the Saturn, Space Transportation System, and future launch vehicle programs such as Shuttle-C and the National Launch System. A technical description of the tunnel is presented for background information on the type and capabilities of the 14-Inch Wind Tunnel. The report concludes in stating: the 14-Inch Wind Tunnel as in speed of sound; transonic, at or near the speed of sound the past, will continue to play a large but unseen role in he development of America's space program.

Tissue Distribution and Metabolism of Aflatoxin B1-14C in Broiler Chickens

PubMed Central

Mabee, Michael S.; Chipley, John R.

1973-01-01

The effects of administering low levels of aflatoxin B1-14C by crop intubation daily for 14 days to broiler chickens were determined. Studies on the distribution of 14C in the blood, selected organs, tissues, and excreta were conducted. No toxic effects were observed in broiler chickens during the 14 days of the experiment. The broiler chickens excreted 90.64% of the 14C administered. Of the 14C retained, 11.04, 9.83, 4.30, 12.52, 31.66, and 30.63% were detected in the blood, liver, heart, gizzard, breast, and leg, respectively. Chemical assay of those samples demonstrating radioactivity revealed that 81.2% of the radioactivity in these substrates was not extractable by classical extraction procedures while approximately 10% was extractable. Treatment of aqueous extracts for conjugated steroids by treatments with beta-glucuronidase revealed that 31.5% of the 14C detected in the aqueous extract was a liberated glucuronide conjugate of aflatoxin M1-14C. PMID:4715554

The Arrival of Homo sapiens into the Southern Cone at 14,000 Years Ago

PubMed Central

Politis, Gustavo G.; Gutiérrez, María A.; Blasi, Adriana

2016-01-01

The Arroyo Seco 2 site contains a rich archaeological record, exceptional for South America, to explain the expansion of Homo sapiens into the Americas and their interaction with extinct Pleistocene mammals. The following paper provides a detailed overview of material remains found in the earliest cultural episodes at this multi-component site, dated between ca. 12,170 14C yrs B.P. (ca. 14,064 cal yrs B.P.) and 11,180 14C yrs B.P. (ca. 13,068 cal yrs B.P.). Evidence of early occupations includes the presence of lithic tools, a concentration of Pleistocene species remains, human-induced fractured animal bones, and a selection of skeletal parts of extinct fauna. The occurrence of hunter-gatherers in the Southern Cone at ca. 14,000 cal yrs B.P. is added to the growing list of American sites that indicate a human occupation earlier than the Clovis dispersal episode, but posterior to the onset of the deglaciation of the Last Glacial Maximum (LGM) in the North America. PMID:27683248

The Arrival of Homo sapiens into the Southern Cone at 14,000 Years Ago.

PubMed

Politis, Gustavo G; Gutiérrez, María A; Rafuse, Daniel J; Blasi, Adriana

The Arroyo Seco 2 site contains a rich archaeological record, exceptional for South America, to explain the expansion of Homo sapiens into the Americas and their interaction with extinct Pleistocene mammals. The following paper provides a detailed overview of material remains found in the earliest cultural episodes at this multi-component site, dated between ca. 12,170 14C yrs B.P. (ca. 14,064 cal yrs B.P.) and 11,180 14C yrs B.P. (ca. 13,068 cal yrs B.P.). Evidence of early occupations includes the presence of lithic tools, a concentration of Pleistocene species remains, human-induced fractured animal bones, and a selection of skeletal parts of extinct fauna. The occurrence of hunter-gatherers in the Southern Cone at ca. 14,000 cal yrs B.P. is added to the growing list of American sites that indicate a human occupation earlier than the Clovis dispersal episode, but posterior to the onset of the deglaciation of the Last Glacial Maximum (LGM) in the North America.

14 CFR Appendix C to Part 29 - Icing Certification

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Icing Certification C Appendix C to Part 29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Pt. 29, App. C Appendix C to Part 29—Icing Certification (a...

Use of natural diamonds to monitor 14C AMS instrument backgrounds

NASA Astrophysics Data System (ADS)

Taylor, R. E.; Southon, John

2007-06-01

To examine one component of the instrument-based background in the University of California Keck Carbon Cycle AMS spectrometer, we have obtained measurements on a set of natural diamonds pressed into sample holders. Natural diamond samples (N = 14) from different sources within rock formations with geological ages greatly in excess of 100 Ma yielded a range of currents (∼110-250 μA 12C- where filamentous graphite typically yields ∼150 μA 12C-) and apparent 14C ages (64.9 ± 0.4 ka BP [0.00031 ± 0.00002 fm] to 80.0 ± 1.1 ka BP [0.00005 ± 0.00001 fm]). Six fragments cut from a single diamond exhibited essentially identical 14C values - 69.3 ± 0.5 ka-70.6 ± 0.5 ka BP. The oldest 14C age equivalents were measured on natural diamonds which exhibited the highest current yields.

STABLE CARBON ISOTOPE BIOGEOCHEMISTRY OF A SHALLOW SAND AQUIFER CONTAMINATED WITH FUEL HYDROCARBONS

EPA Science Inventory

Ground-water chemistry and the stable C isotope composition ( 13CDIC) of dissolved C (DIC) were measured in a sand aquifer contaminated with JP-4 fuel hydrocarbons. Results show that ground water in the upgradient zone was characterized by DIC content of 14-20 mg C/L and 13CDIC...

Occupational exposure to blood and body fluids: new postexposure prophylaxis recommendations. United States Occupational Safety and Health Administration.

PubMed

Cuny, E; Carpenter, W M

1998-04-01

Dental health care professionals continue to suffer exposure incidents from instruments contaminated with blood and/or body fluids from patients. Each of these cases requires that a rigid protocol be followed for their evaluation. New information regarding the risk factors for HIV-seroconversion following an exposure incident have been identified. Recent data has demonstrated that a 79 percent reduction in disease transmission may be possible with a new combination drug therapy. The anti-retroviral drugs included in this new regimen are now standard in the management of occupational exposure to HIV. Several factors set dentistry apart from other health care occupations, and these differences appear to have an effect on the risks associated with occupational exposures. This article explores these risk factors and the new recommendations for postexposure care.

Assessment of arsenic surface contamination in a museum anthropology department.

PubMed

Gribovich, Andrey; Lacey, Steven; Franke, John; Hinkamp, David

2013-02-01

To assess potential arsenic (As) contamination of work surfaces to improve upon the control strategy at an anthropology department in a large natural history museum. Work practices were observed and control strategy reviewed to inform an occupational hygiene assessment strategy utilizing surface wipe sampling. A total of 35 sampling targets were identified, focusing on surfaces that receive high touch traffic, including workstations, artifact transport carts, and elevator buttons. Arsenic sampling and analysis were performed using reference method Occupational Safety and Health Administration ID-125G. Four of the sampling areas returned detectable levels of As, ranging from 0.052 to 0.350 μg/100 cm. Workplace observations and wipe sampling data enabled the development of recommendations to help to further reduce potential occupational exposure to As. Continuous reduction of surface contamination is prudent for known human carcinogens.

14 CFR Appendix C to Part 420 - Risk Analysis

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Risk Analysis C Appendix C to Part 420... TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Pt. 420, App. C Appendix C to Part 420—Risk Analysis (a... table C-1. Table C-1 provides sources where an applicant may obtain data acceptable to the FAA. An...

Potential health and environmental issues of mercury-contaminated amalgamators.

PubMed

Roberts, H W; Leonard, D; Osborne, J

2001-01-01

Dental amalgamators may become contaminated internally with metallic mercury. This contamination may result from mercury leakage from capsules during trituration or from the long-term accrual from microscopic exterior contaminants that result from the industrial assembly process. The potential health risk to dental personnel from this contamination is unknown. The authors assessed used amalgamators from the federal service inventory for the amounts of mercury vapor levels, as well as the visual presence of mercury contamination. They evaluated these amalgamators for potential mercury vapor health risk, using established National Institute for Occupational Safety and Health methods and American Conference of Governmental Industrial Hygienists standards. Ten of the 11 amalgamators assessed had measurable mercury vapor levels. Four amalgamators were found to have internal static mercury vapor levels above Occupational Safety and Health Administration ceiling limit thresholds. During a simulated worst-case clinical use protocol, the authors found that no amalgamators produced mercury vapor in the breathing space of dental personnel that exceeded established time-weighted federal mercury vapor limits. Amalgamators may be contaminated internally with metallic mercury. Although the authors detected mercury vapor from these units during aggressive, simulated clinical use, dilution factors combined with room air exchange were found to keep health risks below established federal safety thresholds. Dental personnel should be aware that amalgamators may be contaminated with mercury and produce minute amounts of mercury vapor. These contaminated amalgamators may require disposal as environmentally hazardous waste.

A DFT study of thermodynamic properties of C36 and C14 Fe2Zr Laves phases

NASA Astrophysics Data System (ADS)

Ali, Kawsar; Ghosh, P. S.; Arya, A. K.

2018-04-01

Fe-Zr alloys are promising materials for metallic waste immobilization in nuclear industry. C36 and C14 Fe2Zr Laves phases are frequently observed in Fe-Zr alloys that can host radionuclides. The phonon dispersions of C36 and C14 Fe2Zr Laves phases shows that both intermetallics are dynamically stable. The Helmholtz free energy, vibrational entropy, internal energy and specific heat at constant volume has been calculated. The zero point energies of C36 and C14 phases are 9.23 and 9.91 kJ/mole, respectively. The vibrational free energy becomes negative at 250 K and 270 K. The high temperature specific heat at constant volume of both intermetallics is 74 J/K/mole.

Occupational Chest Problems

PubMed Central

Markham, John

1976-01-01

The interaction between chest problems and occupational environments occurs in a field wider than industry. Some common examples are described to show where the family physician's index of suspicion should be raised concerning occupational relationships of such problems. Imagesp60-ap60-bp60-cp61-ap61-bp61-c PMID:21308038

75 FR 52988 - National Advisory Committee on Occupational Safety and Health

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-30

... DEPARTMENT OF LABOR Occupational Safety and Health Administration [Docket No. OSHA-2010-0012] National Advisory Committee on Occupational Safety and Health AGENCY: Occupational Safety and Health... Occupational Safety and Health (NACOSH) will meet September 14 and 15, 2010, in Washington, DC. In conjunction...

14C content in vegetation in the vicinities of Brazilian nuclear power reactors.

PubMed

Dias, Cíntia Melazo; Santos, Roberto Ventura; Stenström, Kristina; Nícoli, Iêda Gomes; Skog, Göran; da Silveira Corrêa, Rosangela

2008-07-01

(14)C specific activities were measured in grass samples collected around Brazilian nuclear power reactors. The specific activity values varied between 227 and 299 Bq/kg C. Except for two samples which showed (14)C specific activities 22% above background values, half of the samples showed background specific activities, and the other half had a (14)C excess of 1-18%. The highest specific activities were found close to the nuclear power plants and along the main wind directions (NE and NNE). The activity values were found to decrease with increasing distance from the reactors. The unexpectedly high (14)C excess values found in two samples were related to the local topography, which favors (14)C accumulation and limits the dispersion of the plume. The results indicate a clear (14)C anthropogenic signal within 5 km around the nuclear power plants which is most prominent along northeastwards, the prevailing wind direction.

14CO2 processing using an improved and robust molecular sieve cartridge

NASA Astrophysics Data System (ADS)

Wotte, Anja; Wordell-Dietrich, Patrick; Wacker, Lukas; Don, Axel; Rethemeyer, Janet

2017-06-01

Radiocarbon (14C) analysis on CO2 can provide valuable information on the carbon cycle as different carbon pools differ in their 14C signature. While fresh, biogenic carbon shows atmospheric 14C concentrations, fossil carbon is 14C free. As shown in previous studies, CO2 can be collected for 14C analysis using molecular sieve cartridges (MSC). These devices have previously been made of plastic and glass, which can easily be damaged during transport. We thus constructed a robust MSC suitable for field application under tough conditions or in remote areas, which is entirely made of stainless steel. The new MSC should also be tight over several months to allow long sampling campaigns and transport times, which was proven by a one year storage test. The reliability of the 14CO2 results obtained with the MSC was evaluated by detailed tests of different procedures to clean the molecular sieve (zeolite type 13X) and for the adsorption and desorption of CO2 from the zeolite using a vacuum rig. We show that the 14CO2 results are not affected by any contamination of modern or fossil origin, cross contamination from previous samples, and by carbon isotopic fractionation. In addition, we evaluated the direct CO2 transfer from the MSC into the automatic graphitization equipment AGE with the subsequent 14C AMS analysis as graphite. This semi-automatic approach can be fully automated in the future, which would allow a high sample throughput. We obtained very promising, low blank values between 0.0018 and 0.0028 F14C (equivalent to 50,800 and 47,200 yrs BP), which are within the analytical background and lower than results obtained in previous studies.

17 CFR 240.3a12-11 - Exemption from sections 8(a), 14(a), 14(b), and 14(c) for debt securities listed on a national...

Code of Federal Regulations, 2010 CFR

2010-04-01

...), 14(a), 14(b), and 14(c) for debt securities listed on a national securities exchange. 240.3a12-11... 14(c) for debt securities listed on a national securities exchange. (a) Debt securities that are listed for trading on a national securities exchange shall be exempt from the restrictions on borrowing...

Symposium Proceedings--Occupational Research and the Navy--Prospectus 1980. Technical Report No. 74-14.

ERIC Educational Resources Information Center

Jones, Earl I., Ed.

This five-section symposium report includes 22 papers assessing the state-of-the-art in occupational research. Section 1, Occupational Analysis, Structure, and Methods, contains four papers that discuss: the Air Force Occupational Research project, methodologies in job analysis, evaluation, structures and requirements, career development,…

Factors and processes governing the C-14 content of carbonate in desert soils

NASA Technical Reports Server (NTRS)

Amundson, Ronald; Wang, Yang; Chadwick, Oliver; Trumbore, Susan; Mcfadden, Leslie; Mcdonald, Eric; Wells, Steven; Deniro, Michael

1994-01-01

A model is presented describing the factors and processes which determine the measured C-14 ages of soil calcium carbonate. Pedogenic carbonate forms in isotopic equilium with soil CO2. Carbon dioxide in soils is a mixture of CO2 derived from two biological sources: respiration by living plant roots and respiration of microorganisms decomposing soil humus. The relative proportion of these two CO2 sources can greatly affect the initial C-14 content of pedogenic carbonate: the greater the contribution of humus-derived CO2, the greater the initial C-14 age of the carbonate mineral. For any given mixture of CO2 sources, the steady-state (14)CO2 distribution vs. soil depth can be described by a production/diffusion model. As a soil ages, the C-14 age of soil humus increases, as does the steady-state C-14 age of soil CO2 and the initial C-14 age of any pedogenic carbonate which forms. The mean C-14 age of a complete pedogenic carbonate coating or nodule will underestimate the true age of the soil carbonate. This discrepancy increases the older a soil becomes. Partial removal of outer (and younger) carbonate coatings greatly improves the relationship between measured C-14 age and true age. Although the production/diffusion model qualitatively explains the C-14 age of pedogenic carbonate vs. soil depth in many soils, other factors, such as climate change, may contribute to the observed trends, particularily in soils older than the Holocene.

MEASUREMENTS OF PAST 14C LEVELS AND 13C/12C RATIOS IN THE SURFACE WATERS OF THE WORLD'S SUBPOLAR OCEANS.

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

Brown, T A

2010-04-22

Under this project we have developed methods that allow the reconstruction of past {sup 14}C levels of the surface waters of the subpolar North Pacific Ocean by measuring the {sup 14}C contents of archived salmon scales. The overall goal of this research was to reduce of the uncertainty in the uptake of fossil CO{sub 2} by the oceans and thereby improve the quantification of the global carbon cycle and to elucidate the fate of anthropogenic CO{sub 2}. Ocean General Circulation Models (OGCMs), with their three dimensional global spatial coverage and temporal modeling capabilities, provide the best route to accurately calculatingmore » the total uptake of CO{sub 2} by the oceans and, hence, to achieving the desired reduction in uncertainty. {sup 14}C has played, and continues to play, a central role in the validation of the OGCMs calculations, particularly with respect to those model components which govern the uptake of CO{sub 2} from the atmosphere and the transport of this carbon within the oceans. Under this project, we have developed time-series records of the {sup 14}C levels of the surface waters of three areas of the subpolar North Pacific Ocean. As the previously available data on the time-history of oceanic surface water {sup 14}C levels are very limited, these time-series records provide significant new {sup 14}C data to constrain and validate the OGCMs.« less

Biokinetic and dosimetric investigations of 14C-labeled substances in man using AMS

NASA Astrophysics Data System (ADS)

Mattsson, Sören; Gunnarsson, Mikael; Svegborn, Sigrid Leide; Nosslin, Bertil; Nilsson, Lars-Erik; Thorsson, Ola; Valind, Sven; Åberg, Magnus; Östberg, Henrik; Hellborg, Ragnar; Stenström, Kristina; Erlandsson, Bengt; Faarinen, Mikko; Kiisk, Madis; Magnusson, Carl-Erik; Persson, Per; Skog, Göran

2001-07-01

Up to now, radiation dose estimates from radiopharmaceuticals, labeled with pure β-emitting radionuclides, e.g., 14C or 3H have been very uncertain. Using accelerator mass spectrometry (AMS) we have derived new and improved data for 14C-triolein and 14C-urea and are currently running a program related to the biokinetics and dosimetry of 14C-glycocholic acid and 14C-xylose. The results of our investigations have made it possible to widen the indications for the clinical use of the 14C-urea test for Helicobacter pylori infection in children. The use of ultra-low activities, which is possible with AMS (down to 1/1000 of that used for liquid scintillation counting), has opened the possibility for metabolic investigations on children as well as on other sensitive patient groups like new-borns, and pregnant or breast-feeding women. Using the full potential of AMS, new 14C-labeled drugs could be tested on humans at a much earlier stage than today, avoiding uncertain extrapolations from animal models.

Influence of processing on the microstructure and mechanical properties of 14YWT

DOE PAGES

Hoelzer, David T.; Unocic, Kinga A.; Sokolov, Mikhail A.; ...

2015-12-15

In this study, the investigation of the mechanical alloying (MA) conditions for producing the advanced oxide dispersion strengthened (ODS) 14YWT ferritic alloy led to significant improvements in balancing the strength, ductility and fracture toughness properties while still maintaining the salient microstructural features consisting of ultra-fine grains and high concentration of Y-, Ti- and O-enriched nanoclusters. The implemented changes to the processing conditions included reducing the contamination of the powder during ball milling, applying a pre-extrusion annealing treatment on the ball milled powder and exploring different extrusion temperatures at 850 °C (SM170 heat), 1000 °C (SM185) and 1150 °C (SM200). Themore » microstructural studies of the three 14YWT heats showed similarities in the dispersion of nanoclusters and sub-micron size grains, indicating the microstructure was insensitive to the different extrusion conditions. Compared to past 14YWT heats, the three new heats showed lower strength, but higher ductility levels between 25 and 800 °C and significantly higher fracture toughness values between 25 °C and 700 °C. The lower contamination levels of O, C and N achieved with improved ball milling conditions plus the slightly larger grain size were identified as important factors for improving the balance in mechanical properties of the three heats of 14YWT.« less

Identification of the receptors for somatostatin (SST) and cortistatin (CST) in chickens and investigation of the roles of cSST28, cSST14, and cCST14 in inhibiting cGHRH1-27NH2-induced growth hormone secretion in cultured chicken pituitary cells.

PubMed

Meng, Fengyan; Huang, Guian; Gao, Shunyu; Li, Juan; Yan, Zhenxin; Wang, Yajun

2014-03-25

Somatostatin receptors (SSTRs) are proposed to mediate the actions of somatostatin (SST) and its related peptide, cortistatin (CST), in vertebrates. However, the identity, functionality, and tissue expression of these receptors remain largely unknown in most non-mammalian vertebrates including birds. In this study, five SSTRs (named cSSTR1, cSSTR2, cSSTR3, cSSTR4, cSSTR5) were cloned from chicken brain by RT-PCR. Using a pGL3-CRE-luciferase reporter system, we demonstrated that activation of each cSSTR expressed in CHO cells by cSST28, cSST14 and cCST14 treatment could inhibit forskolin-induced luciferase activity of CHO cells, indicating the functional coupling of all cSSTRs to Gi protein(s). Interestingly, cSSTR1-4 expressed in CHO cells could be activated by cSST28, cSST14 and cCST14 with high potencies, suggesting that they may function as the receptors common for these peptides. In contrast, cSSTR5 could be potently activated by cSST28 only, indicating that it is a cSST28-specific receptor. Using RT-PCR, wide expression of cSSTRs was detected in chicken tissues including pituitary. In accordance with their expression in pituitary, cSST28, cSST14, and cCST14 were demonstrated to inhibit basal and novel cGHRH1-27NH2-induced GH secretion in cultured chicken pituitary cells dose-dependently (0-10nM) by Western blot analysis, suggesting the involvement of cSSTR(s) common for these peptides in mediating their inhibitory actions. Collectively, our study establishes a molecular basis to elucidate the roles of SST/CST in birds and provide insights into the roles of SST/CST in vertebrates, such as their conserved actions on pituitary. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Stepped-combustion 14C dating of bomb carbon in lake sediment

USGS Publications Warehouse

McGeehin, J.; Burr, G.S.; Hodgins, G.; Bennett, S.J.; Robbins, J.A.; Morehead, N.; Markewich, H.

2004-01-01

In this study, we applied a stepped-combustion approach to dating post-bomb lake sediment from north-central Mississippi. Samples were combusted at a low temperature (400 ??C) and then at 900 ??C. The CO2 was collected separately for both combustions and analyzed. The goal of this work was to develop a methodology to improve the accuracy of 14C dating of sediment by combusting at a lower temperature and reducing the amount of reworked carbon bound to clay minerals in the sample material. The 14C fraction modern results for the low and high temperature fractions of these sediments were compared with well-defined 137Cs determinations made on sediment taken from the same cores. Comparison of "bomb curves" for 14C and 137Cs indicate that low temperature combustion of sediment improved the accuracy of 14C dating of the sediment. However, fraction modern results for the low temperature fractions were depressed compared to atmospheric values for the same time frame, possibly the result of carbon mixing and the low sedimentation rate in the lake system.

Stressful life events and occupational accidents.

PubMed

Cordeiro, Ricardo; Dias, Adriano

2005-10-01

The purpose of this study was to examine the association between stressful life events and occupational accidents. This was a population-based case-control study, carried out in the city of Botucatu, in southeast Brazil. The cases consisted of 108 workers who had recently experienced occupational accidents. Each case was matched with three controls. The cases and controls answered a questionnaire about recent exposure to stressful life events. Reporting of "environmental problems", "being a victim of assault", "not having enough food at home" and "nonoccupational fatigue" were found to be risk factors for work-related accidents with estimated incidence rate ratios of 1.4 [95% confidence interval (95% CI) 1.1-1.7], 1.3 (95% CI 1.1-1.7), 1.3 (95% CI 1.1-1.6), and 1.4 (95% CI 1.2-1.7) respectively. The findings of the study suggested that nonwork variables contribute to occupational accidents, thus broadening the understanding of these phenomena, which can support new approaches to the prevention of occupational accidents.

14 CFR Appendixes C-E to Part 36 - [Reserved

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false [Reserved] C Appendixes C-E to Part 36 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT NOISE STANDARDS: AIRCRAFT TYPE AND AIRWORTHINESS CERTIFICATION Appendixes C-E to Part 36 [Reserved] ...

14 CFR Appendixes C-E to Part 36 - [Reserved

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false [Reserved] C Appendixes C-E to Part 36 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT NOISE STANDARDS: AIRCRAFT TYPE AND AIRWORTHINESS CERTIFICATION Appendixes C-E to Part 36 [Reserved] ...

14 CFR Appendixes C-E to Part 36 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false [Reserved] C Appendixes C-E to Part 36 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT NOISE STANDARDS: AIRCRAFT TYPE AND AIRWORTHINESS CERTIFICATION Appendixes C-E to Part 36 [Reserved] ...

Probable alpha and 14C cluster emission from hyper Ac nuclei

NASA Astrophysics Data System (ADS)

Santhosh, K. P.

2013-10-01

A systematic study on the probability for the emission of 4He and 14C cluster from hyper {Λ/207-234}Ac and non-strange normal 207-234Ac nuclei are performed for the first time using our fission model, the Coulomb and proximity potential model (CPPM). The predicted half lives show that hyper {Λ/207-234}Ac nuclei are unstable against 4He emission and 14C emission from hyper {Λ/217-228}Ac are favorable for measurement. Our study also show that hyper {Λ/207-234}Ac are stable against hyper {Λ/4}He and {Λ/14}C emission. The role of neutron shell closure ( N = 126) in hyper {Λ/214}Fr daughter and role of proton/neutron shell closure ( Z ≈ 82, N = 126) in hyper {Λ/210}Bi daughter are also revealed. As hyper-nuclei decays to normal nuclei by mesonic/non-mesonic decay and since most of the predicted half lives for 4He and 14C emission from normal Ac nuclei are favourable for measurement, we presume that alpha and 14C cluster emission from hyper Ac nuclei can be detected in laboratory in a cascade (two-step) process.

Detecting Human Presence at the Border of the Northeastern Italian Pre-Alps. 14C Dating at Rio Secco Cave as Expression of the First Gravettian and the Late Mousterian in the Northern Adriatic Region

PubMed Central

Talamo, Sahra; Peresani, Marco; Romandini, Matteo; Duches, Rossella; Jéquier, Camille; Nannini, Nicola; Pastoors, Andreas; Picin, Andrea; Vaquero, Manuel; Weniger, Gerd-Christian; Hublin, Jean-Jacques

2014-01-01

In the northern Adriatic regions, which include the Venetian region and the Dalmatian coast, late Neanderthal settlements are recorded in few sites and even more ephemeral are remains of the Mid-Upper Palaeolithic occupations. A contribution to reconstruct the human presence during this time range has been produced from a recently investigated cave, Rio Secco, located in the northern Adriatic region at the foot of the Carnic Pre-Alps. Chronometric data make Rio Secco a key site in the context of recording occupation by late Neanderthals and regarding the diffusion of the Mid-Upper Palaeolithic culture in a particular district at the border of the alpine region. As for the Gravettian, its diffusion in Italy is a subject of on-going research and the aim of this paper is to provide new information on the timing of this process in Italy. In the southern end of the Peninsula the first occupation dates to around 28,000 14C BP, whereas our results on Gravettian layer range from 29,390 to 28,995 14C years BP. At the present state of knowledge, the emergence of the Gravettian in eastern Italy is contemporaneous with several sites in Central Europe and the chronological dates support the hypothesis that the Swabian Gravettian probably dispersed from eastern Austria. PMID:24759802

CONVERSION OF LACTATE-C14 TO PROPIONATE BY THE RUMEN MICROFLORA12

PubMed Central

Baldwin, R. L.; Wood, W. A.; Emery, R. S.

1962-01-01

Baldwin, R. L. (Michigan State University, East Lansing), W. A. Wood, and R. S. Emery. Conversion of lactate-C14 to propionate by the rumen microflora. J. Bacteriol. 83:907–913. 1962.—Rumen microflora enriched on five different diets calculated to present increasing carbohydrate or lactate availability were used to determine the contribution of the randomizing (succinate) and nonrandomizing (acrylate) routes to propionate with lactate-2-C14 and -3-C14 as substrates. Propionate was labeled as though 70 to 90% was formed via the nonrandomizing route. This percentage was highest on diets containing high levels of carbohydrate or lactate or both. Evidence for the presence of succinic dehydrogenase, acetokinase, phosphotransacetylase, and coenzyme A transphorase was obtained with cell-free extracts. Propionate-2-C14 and lactate-2-C14 were converted by extracts to the activated derivatives of acrylate, lactate, propionate, and acetate. PMID:13864343

Towards the measurement of the13C(d, p)14C cross section using AMS

NASA Astrophysics Data System (ADS)

Murillo-Morales, S.; Barrón-Palos, L.; Chávez, E.; Araujo-Escalona, V.

2017-07-01

A plan to study the total cross section for the13C(d, p)14C nuclear reaction has been developed for energies in the center-of-mass frame between 133 and 400 keV. The proposed experiment will use a deuterium beam (1-3 MeV of energy) from the Instituto de Física-UNAM 5.5 MV Van de Graaff accelerator and the produced14C will be afterwards measured by AMS technique in the LEMA-UNAM (HVEE 1 MV Tandetron). One of the main goals is to study the performance of the LEMA-UNAM facility in the cross section measurement in comparison with other data reported in the literature, measured by other techniques. In this work we present the current status of these studies. The relevance of the13C(d, p)14C reaction in the study of compound nucleus formation as well as in some astrophysics scenarios, and the importance of the development of the AMS technique to measure cross sections of nuclear reactions of astrophysical interest in Mixico are also discussed.

Low-pressure RF remote plasma cleaning of carbon-contaminated B4C-coated optics

NASA Astrophysics Data System (ADS)

Moreno Fernández, H.; Thomasset, M.; Sauthier, G.; Rogler, D.; Dietsch, R.; Barrett, R.; Carlino, V.; Pellegrin, E.

2017-05-01

Boron carbide (B4C) - due to its exceptional mechanical properties - is one of the few existing materials that can withstand the extremely high brilliance of the photon beam from free electron lasers (FELs) and is thus of considerable interest for optical applications in this field. However, as in the case of many other optics operated at modern accelerator-, plasma-, or laser-based light source facilities, B4C-coated optics are subject to ubiquitous carbon contaminations. These contaminations - that are presumably produced via cracking of CHx and CO2 molecules by photoelectrons emitted from the optical components - represent a serious issue for the operation of the pertinent high performance beamlines due to a severe reduction of photon flux and beam coherence, not necessarily restricted to the photon energy range of the carbon K-edge. Thus, a variety of B4C cleaning technologies have been developed at different laboratories with varying success [1]. Here, we present a study regarding the low-pressure RF plasma cleaning of a series of carbon-contaminated B4C test samples via an inductively coupled O2/Ar and Ar/H2 remote RF plasma produced using the IBSS GV10x plasma source following previous studies using the same RF plasma source [2, 3]. Results regarding the chemistry, morphology as well as other aspects of the B4C optical coatings and surfaces before and after the plasma cleaning process are reported.

Analysis of 14C and 13C in teeth provides precise birth dating and clues to geographical origin

PubMed Central

K, Alkass; BA, Buchholz; H, Druid; KL, Spalding

2011-01-01

The identification of human bodies in situations when there are no clues as to the person’s identity from circumstantial data, poses a difficult problem to investigators. The determination of age and sex of the body can be crucial in order to limit the search to individuals that are a possible match. We analyzed the proportion of bomb pulse derived carbon-14 (14C) incorporated in the enamel of teeth from individuals from different geographical locations. The ‘bomb pulse’ refers to a significant increase in 14C levels in the atmosphere caused by above ground test detonations of nuclear weapons during the cold war (1955-1963). By comparing 14C levels in enamel with 14C atmospheric levels systematically recorded over time, high precision birth dating of modern biological material is possible. Above ground nuclear bomb testing was largely restricted to a couple of locations in the northern hemisphere, producing differences in atmospheric 14C levels at various geographical regions, particularly in the early phase. Therefore, we examined the precision of 14C birth dating of enamel as a function of time of formation and geographical location. We also investigated the use of the stable isotope 13C as an indicator of geographical origin of an individual. Dental enamel was isolated from 95 teeth extracted from 84 individuals to study the precision of the 14C method along the bomb spike. For teeth formed before 1955 (N = 17), all but one tooth showed negative Δ14C values. Analysis of enamel from teeth formed during the rising part of the bomb-spike (1955-1963, N = 12) and after the peak (>1963, N = 66) resulted in an average absolute date of birth estimation error of 1.9 ±1.4 and 1.3 ± 1.0 years, respectively. Geographical location of an individual had no adverse effect on the precision of year of birth estimation using radiocarbon dating. In 46 teeth, measurement of 13C was also performed. Scandinavian teeth showed a substantially greater depression in average δ13C

Analysis of 14C and 13C in teeth provides precise birth dating and clues to geographical origin.

PubMed

Alkass, K; Buchholz, B A; Druid, H; Spalding, K L

2011-06-15

The identification of human bodies in situations when there are no clues as to the person's identity from circumstantial data, poses a difficult problem to the investigators. The determination of age and sex of the body can be crucial in order to limit the search to individuals that are a possible match. We analyzed the proportion of bomb pulse derived carbon-14 ((14)C) incorporated in the enamel of teeth from individuals from different geographical locations. The 'bomb pulse' refers to a significant increase in (14)C levels in the atmosphere caused by above ground test detonations of nuclear weapons during the cold war (1955-1963). By comparing (14)C levels in enamel with (14)C atmospheric levels systematically recorded over time, high precision birth dating of modern biological material is possible. Above ground nuclear bomb testing was largely restricted to a couple of locations in the northern hemisphere, producing differences in atmospheric (14)C levels at various geographical regions, particularly in the early phase. Therefore, we examined the precision of (14)C birth dating of enamel as a function of time of formation and geographical location. We also investigated the use of the stable isotope (13)C as an indicator of geographical origin of an individual. Dental enamel was isolated from 95 teeth extracted from 84 individuals to study the precision of the (14)C method along the bomb spike. For teeth formed before 1955 (N=17), all but one tooth showed negative Δ(14)C values. Analysis of enamel from teeth formed during the rising part of the bomb-spike (1955-1963, N=12) and after the peak (>1963, N=66) resulted in an average absolute date of birth estimation error of 1.9±1.4 and 1.3±1.0 years, respectively. Geographical location of an individual had no adverse effect on the precision of year of birth estimation using radiocarbon dating. In 46 teeth, measurement of (13)C was also performed. Scandinavian teeth showed a substantially greater depression in

ATM C and D panel/EREP cooling system contamination problem. [on Skylab

NASA Technical Reports Server (NTRS)

Williamson, J. G.

1973-01-01

This report presents the history of a preflight contamination problem that occurred in the ATM C and D panel/EREP cooling system on the Skylab, the studies that were made to determine the cause of the problem, and corrective actions that were made prior to lift-off. The results of all the observations, analyses and laboratory testing indicated that the contamination came from one or more of the EREP tape recorder coldplates and was caused by some abnormal electrolytic action, either during bench testing or in the spacecraft. Studies indicate that no such electrolytic action is likely to occur under normal operating conditions.

17 CFR 240.14c-7 - Providing copies of material for certain beneficial owners.

Code of Federal Regulations, 2010 CFR

2010-04-01

... for certain beneficial owners. 240.14c-7 Section 240.14c-7 Commodity and Securities Exchanges... Information Pursuant to Section 14(c) § 240.14c-7 Providing copies of material for certain beneficial owners... is supplied with Notices of Internet Availability of Proxy Materials, information statements and/or...

Dissolved Organic Carbon 14C in Southern Nevada Groundwater and Implications for Groundwater Travel Times

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

Hershey, Ronald L.; Fereday, Wyall; Thomas, James M

Dissolved inorganic carbon (DIC) carbon-14 ( 14C) ages must be corrected for complex chemical and physical reactions and processes that change the amount of 14C in groundwater as it flows from recharge to downgradient areas. Because of these reactions, DIC 14C can produce unrealistically old ages and long groundwater travel times that may, or may not, agree with travel times estimated by other methods. Dissolved organic carbon (DOC) 14C ages are often younger than DIC 14C ages because there are few chemical reactions or physical processes that change the amount of DOC 14C in groundwater. However, there are several issuesmore » that create uncertainty in DOC 14C groundwater ages including limited knowledge of the initial (A 0) DOC 14C in groundwater recharge and potential changes in DOC composition as water moves through an aquifer. This study examines these issues by quantifying A 0 DOC 14C in recharge areas of southern Nevada groundwater flow systems and by evaluating changes in DOC composition as water flows from recharge areas to downgradient areas. The effect of these processes on DOC 14C groundwater ages is evaluated and DOC and DIC 14C ages are then compared along several southern Nevada groundwater flow paths. Twenty-seven groundwater samples were collected from springs and wells in southern Nevada in upgradient, midgradient, and downgradient locations. DOC 14C for upgradient samples ranged from 96 to 120 percent modern carbon (pmc) with an average of 106 pmc, verifying modern DOC 14C ages in recharge areas, which decreases uncertainty in DOC 14C A 0 values, groundwater ages, and travel times. The HPLC spectra of groundwater along a flow path in the Spring Mountains show the same general pattern indicating that the DOC compound composition does not change along this flow path. Although DOC concentration decreases from recharge-area to downgradient groundwater, the organic compounds are similar, indicating that DOC 14C is unaffected by other processes such

Comparison of Accuracy Between 13C- and 14C-Urea Breath Testing: Is an Indeterminate-Results Category Still Needed?

PubMed

Charest, Mathieu; Bélair, Marc-André

2017-06-01

Helicobacter pylori infection is the leading cause of peptic ulcer disease. The purpose of this study was, first, to assess the difference in the distribution of negative versus positive results between the older 14 C-urea breath test and the newer 13 C-urea breath test and, second, to determine whether use of an indeterminate-results category is still meaningful and what type of results should trigger repeated testing. Methods: A retrospective survey was performed of all consecutive patients referred to our service for urea breath testing. We analyzed 562 patients who had undergone testing with 14 C-urea and 454 patients who had undergone testing with 13 C-urea. Results: In comparison with the wide distribution of negative 14 C results, negative 13 C results were distributed farther from the cutoff and were grouped more tightly around the mean negative value. Distribution analysis of the negative results for 13 C testing, compared with those for 14 C testing, revealed a statistically significant difference between the two. Within the 13 C group, only 1 patient could have been classified as having indeterminate results using the same indeterminate zone as was used for the 14 C group. This is significantly less frequent than what was found for the 14 C group. Discussion: Borderline-negative results do occur with 13 C-urea breath testing, although less frequently than with 14 C-urea breath testing, and we will be carefully monitoring differences falling between 3.0 and 3.5 %Δ. 13 C-urea breath testing is safe and simple for the patient and, in most cases, provides clearer positive or negative results for the clinician. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

The distribution of Δ14C in Korea from 2010 to 2013

NASA Astrophysics Data System (ADS)

Park, J. H.; Hong, W.; Xu, X.; Park, G.; Sung, K. S.; Sung, Kilho; Lee, Jong-geol; Nakanishi, T.; Park, Hyo-Seok

2015-10-01

Δ14C values of leaves of a deciduous tree record to those of atmospheric CO2 within error and were used to map out Δ14C distribution in Korea. We collected ginkgo (Ginkgo biloba Linnaeus, a deciduous tree) leaf samples in mid-June to early July from 2009 to 2013 in Korea to obtain the regional distribution of Δ14C. Commonly CO2 emitted from fossil fuel consumption dilutes atmospheric 14C, while operations and accidents at nuclear power plants can increase it. The distribution maps of Δ14C from 2010 to 2013 in Korea shows that Δ14C values in the northwestern and southeastern parts of Korea are lower than those of the other parts of Korea, which is consistent with the population and industry patterns. Decrease rates of annually averaged Δ14C values in Korea over the study period are larger than those of Pt. Barrow, Alaska, USA (71.3°N, 156.5°W), so the difference between them and those of Pt. Barrow, Alaska, USA became larger annually. This may be due to the increase in fossil fuel consumption in Korea and China. The decrease rate between 2010 and 2011 was smaller than in other years. This could be the effect of the Fukushima power plant accident which occurred in March 11, 2011, but further study is needed to clarify it.

Environmental contaminants as etiologic factors for diabetes.

PubMed Central

Longnecker, M P; Daniels, J L

2001-01-01

For both type 1 and type 2 diabetes mellitus, the rates have been increasing in the United States and elsewhere; rates vary widely by country, and genetic factors account for less than half of new cases. These observations suggest environmental factors cause both type 1 and type 2 diabetes. Occupational exposures have been associated with increased risk of diabetes. In addition, recent data suggest that toxic substances in the environment, other than infectious agents or exposures that stimulate an immune response, are associated with the occurrence of these diseases. We reviewed the epidemiologic data that addressed whether environmental contaminants might cause type 1 or type 2 diabetes. For type 1 diabetes, higher intake of nitrates, nitrites, and N-nitroso compounds, as well as higher serum levels of polychlorinated biphenyls have been associated with increased risk. Overall, however, the data were limited or inconsistent. With respect to type 2 diabetes, data on arsenic and 2,3,7,8-tetrachlorodibenzo-p-dioxin relative to risk were suggestive of a direct association but were inconclusive. The occupational data suggested that more data on exposure to N-nitroso compounds, arsenic, dioxins, talc, and straight oil machining fluids in relation to diabetes would be useful. Although environmental factors other than contaminants may account for the majority of type 1 and type 2 diabetes, the etiologic role of several contaminants and occupational exposures deserves further study. PMID:11744505

Muscarinic Receptor Occupancy and Cognitive Impairment: A PET Study with [11C](+)3-MPB and Scopolamine in Conscious Monkeys

PubMed Central

Yamamoto, Shigeyuki; Nishiyama, Shingo; Kawamata, Masahiro; Ohba, Hiroyuki; Wakuda, Tomoyasu; Takei, Nori; Tsukada, Hideo; Domino, Edward F

2011-01-01

The muscarinic cholinergic receptor (mAChR) antagonist scopolamine was used to induce transient cognitive impairment in monkeys trained in a delayed matching to sample task. The temporal relationship between the occupancy level of central mAChRs and cognitive impairment was determined. Three conscious monkeys (Macaca mulatta) were subjected to positron emission tomography (PET) scans with the mAChR radioligand N-[11C]methyl-3-piperidyl benzilate ([11C](+)3-MPB). The scan sequence was pre-, 2, 6, 24, and 48 h post-intramuscular administration of scopolamine in doses of 0.01 and 0.03 mg/kg. Occupancy levels of mAChR were maximal 2 h post-scopolamine in cortical regions innervated primarily by the basal forebrain, thalamus, and brainstem, showing that mAChR occupancy levels were 43–59 and 65–89% in doses of 0.01 and 0.03 mg/kg, respectively. In addition, dose-dependent impairment of working memory performance was measured 2 h after scopolamine. A positive correlation between the mAChR occupancy and cognitive impairment 2 and 6 h post-scopolamine was the greatest in the brainstem (P<0.00001). Although cognitive impairment was not observed 24 h post-scopolamine, sustained mAChR occupancy (11–24%) was found with both doses in the basal forebrain and thalamus, but not in the brainstem. These results indicate that a significant degree of mAChRs occupancy is needed to produce cognitive impairment by scopolamine. Furthermore, the importance of the brainstem cholinergic system in working memory in monkey is described. PMID:21430646

Metabolism and disposition of [14C]-methylcyclosiloxanes in rats.

PubMed

Domoradzki, Jeanne Y; Sushynski, Christopher M; Sushynski, Jacob M; McNett, Debra A; Van Landingham, Cynthia; Plotzke, Kathleen P

2017-10-20

Octamethylcyclotetrasiloxane (D 4 ) and decamethylcyclopentasiloxane (D 5 ) are low molecular weight cyclic volatile methyl siloxanes (cVMSs) primarily used as intermediates or monomers in the production of high molecular weight silicone polymers. The use of D 4 as a direct ingredient in personal care products has declined significantly over the past 20 years, although it may be present as a residual impurity in a variety of consumer products. D 5 is still used as an intentional ingredient in cosmetics, consumer products and in dry cleaning. Persons who may be exposed include occupational exposure for workers, and potential inhalation or dermal exposure for consumers and the general public. Because of the diverse use, especially of D 5 , and the potential for human exposure, a comprehensive program was undertaken to understand the kinetics, metabolism, enzyme induction and toxicity of D 4 and D 5 in rats following relevant routes of exposure. Physiologically based pharmacokinetic (PBPK) models utilizing these studies have been reported for D 4 and D 5 in the rat and human following dermal and inhalation exposures, with the oral uptake component of the model being limited in its description. Data from high dose oral studies in corn oil and simethicone vehicles and neat were used in the D 4 /D 5 harmonized PBPK model development. It was uncertain if the inability to adequately describe the oral uptake was due to unrealistic high doses or unique aspects of the chemistry of D 4 /D 5. Low dose studies were used to provide data to refine the description of oral uptake in the model by exploring the dose dependency and the impact of a more realistic food-like vehicle. Absorption, distribution, metabolism and elimination (ADME) of D 4 and D 5 was determined following a single low oral gavage dose of 14 C-D 4 and 14 C-D 5 at 30 and 100mg/kg body weight (bw), respectively, in a rodent liquid diet. Comparison of the low vs. high dose oral gavage administration of D 4 and D 5

Source apportionment of carbonaceous aerosol in Sao Paulo using 13C and 14C measurements

NASA Astrophysics Data System (ADS)

Oyama, Beatriz; Andrade, Maria de Fatima; Holzinger, Rupert; Röckmann, Thomas; Meijer, Harro A. J.; Dusek, Ulrike

2016-04-01

The Metropolitan Area of Sao Paulo is affected by high aerosol concentrations, which contain a large fraction of organic material. Up to date, not much is known about the composition and origin of the organic aerosol in this city. We present the first source apportionment of the carbonaceous aerosol fraction in Sao Paulo, using stable (13C) and radioactive carbon isotopes (14C). 14C provides a clear-cut distinction between fossil sources, which contain no 14C, and contemporary sources such as biofuels, biomass burning, or biogenic sources, which contain a typical contemporary 14C/12C ratio. 13C can be used to distinguish C3 plants, such as maize and sugarcane, from C4 plants. This can help to identify a possible impact of sugarcane field burning in the rural areas of Sao Paulo State on the aerosol carbon in the city. In the first part of the study, we compare two tunnel studies: Tunnel 1 is frequented only by light duty vehicles, which run mainly on mixtures of gasoline with ethanol (gasohol, 25% ethanol and 85% gasoline) or hydrated ethanol (5% water and 95% ethanol). Tunnel 2 contains a significant fraction of heavy-duty diesel vehicles, and therefore the fraction of biofuels in the average fleet is lower. Comparison of 14C in organic and elemental carbon (OC and EC) shows that in both tunnels there is no significant contribution of biofuels to EC. Combusting ethanol-gasoline fuels in a vehicle engine does apparently not result in significant EC formation from ethanol. Biofuels contribute around 45% to OC in Tunnel 1 an only 20% in Tunnel 2, reflecting a strong impact of diesel vehicles in Tunnel 2. In the second part of the study we conduct a source apportionment of ambient aerosol carbon collected in a field study during winter (July-August) 2012. Ambient EC has two main sources, vehicular emissions and biomass burning. We estimate a contribution of vehicular sources to EC of roughly 90% during weekdays and 80% during weekends, using the 14C values measured in

Measurement of 14C emission rates from a pressurised heavy water reactor.

PubMed

Joshi, M L; Ramamirtham, B; Soman, S D

1987-06-01

Carbon-14 is produced in pressurised heavy water reactors (PHWR), mainly as an activation product in the fuel. It is also produced in the heavy water used as the primary coolant and moderator, and is produced in the air in the annular space between the pressure tube and calandria tubes as well as in the free space in the calandria vault. The production rates in different systems of a PHWR are calculated on the basis of design parameters. During a period of 3 y, 14C released through the gaseous route has been measured at Rajasthan Atomic Power Station, Kota, India, a PHWR unit. These releases have been found to be mainly 14CO2. This reduced form of 14C is less than 5% of the releases. The normalised releases of 14C have a geometric mean of 5.17 TBq GWe-1 y-1 and a geometric standard deviation of 1.52. The 14C present in the form of carbonates in liquid effluents has also been measured and is 0.14% of the gaseous releases.

Microbial degradation of [C14C]polystyrene and 1,3-diphenylbutane.

PubMed

Sielicki, M; Focht, D D; Martin, J P

1978-07-01

Microbial degradation of [beta-14C]polystyrene and 1,3-diphenylbutane, a compound structurally representing the smallest repeating unit of styrene (dimer), was investigated in soil and liquid enrichment cultures. Degradation rates in soil, as determined by 14CO2 evolution from applied [14C]polystyrene, varied from 1.5 to 3.0% for a 4-month period. Although relatively low, these percentages were 15 to 30 times greater than values previously reported. Enrichment cultures, containing 1,3-diphenylbutane as the only carbon souce, were used to determine the mechanisms of microbial oxidation of the polymer chain ends. Metabolism of 1,3-diphenylbutane appeared to involve the attack by a monooxygenease to form 2-phenyl-4-hydroxyphenylbutane followed by a further oxidation and subsequent fission of the benzene ring to yield 4-phenylvaleric acid and an unidentified 5-carbon fragment via the classic meta-fission pathway. Phenylacetic acid was probably formed from 4-phenylvaleric acid by subsequent beta-oxidation of the side chain, methyl-oxidation and decarboxylation. An initial examination of the population of microorganisms in the diphenylbutane enrichment cultures indicated that these oxidative reactions are carried out by common soil microorganism of the genera Bacillus, Pseudomonas, Micrococcus, and Nocardia.

Obtaining molecular and structural information from 13C-14N systems with 13C FIREMAT experiments.

PubMed

Strohmeier, Mark; Alderman, D W; Grant, David M

2002-04-01

The effect of dipolar coupling to 14N on 13C FIREMAT (five pi replicated magic angle turning) experiments is investigated. A method is developed for fitting the 13C FIREMAT FID employing the full theory to extract the 13C-14N dipolar and 13C chemical shift tensor information. The analysis requires prior knowledge of the electric field gradient (EFG) tensor at the 14N nucleus. In order to validate the method the analysis is done for the amino acids alpha-glycine, gamma-glycine, l-alanine, l-asparagine, and l-histidine on FIREMAT FIDs recorded at 13C frequencies of 50 and 100 MHz. The dipolar and chemical shift data obtained with this analysis are in very good agreement with the previous single-crystal 13C NMR results and neutron diffraction data on alpha-glycine, l-alanine, and l-asparagine. The values for gamma-glycine and l-histidine obtained with this new method are reported for the first time. The uncertainties in the EFG tensor on the resultant 13C chemical shift and dipolar tensor values are assessed. (c) 2002 Elsevier Science (USA).

A new approach to assess occupational exposure to airborne fungal contamination and mycotoxins of forklift drivers in waste sorting facilities.

PubMed

Viegas, Carla; Faria, Tiago; de Oliveira, Ana Cebola; Caetano, Liliana Aranha; Carolino, Elisabete; Quintal-Gomes, Anita; Twarużek, Magdalena; Kosicki, Robert; Soszczyńska, Ewelina; Viegas, Susana

2017-11-01

The waste management industry is an important employer, and exposure of waste-handling workers to microorganisms is considered an occupational health problem. Besides fungal contamination, it is important to consider the co-occurrence of mycotoxins in this setting. Forklifts with closed cabinet and air conditioner are commonly used in waste industry to transport waste and other products within the facilities, possibly increasing the risk of exposure under certain conditions. The aim of this study was to assess the fungal contamination and mycotoxin levels in filters from the air conditioning system of forklift cabinets, as an indicator to assess occupational exposure of the drivers working in a waste sorting facility. Cytotoxicity was also assessed to understand and characterize the toxicity of the complex mixtures as present in the forklift filters. Aqueous extracts of filters from 11 vehicles were streaked onto 2% malt extract agar (MEA) with chloramphenicol (0.05 g/L) media, and in dichloran glycerol (DG18) agar-based media for morphological identification of the mycobiota. Real-time quantitative PCR amplification of genes from Aspergillus sections Fumigati, Flavi, Circumdati, and Versicolores was also performed. Mycotoxins were analyzed using LC-MS/MS system. Cytotoxicity of filter extracts was analyzed by using a MTT cell culture test. Aspergillus species were found most frequently, namely Aspergillus sections Circumdati (MEA 48%; DG18 41%) and Nigri (MEA 32%; DG18 17.3%). By qPCR, only Aspergillus section Fumigati species were found, but positive results were obtained for all assessed filters. No mycotoxins were detected in aqueous filter extracts, but most extracts were highly cytotoxic (n = 6) or medium cytotoxic (n = 4). Although filter service life and cytotoxicity were not clearly correlated, the results suggest that observing air conditioner filter replacement frequency may be a critical aspect to avoid worker's exposure. Further research is

Occupational Distribution of Campylobacteriosis and Salmonellosis Cases - Maryland, Ohio, and Virginia, 2014.

PubMed

Su, Chia-Ping; de Perio, Marie A; Fagan, Kathleen; Smith, Meghan L; Salehi, Ellen; Levine, Seth; Gruszynski, Karen; Luckhaupt, Sara E

2017-08-18

Campylobacter and Salmonella are leading causes of bacterial gastroenteritis in the United States and are estimated to cause >1 million episodes of domestically acquired illness annually (1). Campylobacter and Salmonella are primarily transmitted through contaminated food, but animal-to-human and human-to-human transmission can also occur (2,3). Although occupationally acquired infections have been reported, occupational risk factors have rarely been studied. In 2015, the Occupational Safety and Health Administration (OSHA) identified 63 suspected or confirmed cases of Campylobacter infection over 3.5 years at a poultry-processing plant (Kathleen Fagan, OSHA, personal communication, December 2015); most involved new workers handling chickens in the "live hang" area where bacterial contamination is likely to be the highest. These findings were similar to those of a previous study of Campylobacter infections among workers at another poultry-processing plant (4). The investigation led to discussions among OSHA, state health departments, and CDC's National Institute for Occupational Safety and Health (NIOSH); and a surveillance study was initiated to further explore the disease incidence in poultry-processing plant workers and identify any additional occupations at increased risk for common enteric infections. Deidentified reports of campylobacteriosis and salmonellosis among Maryland, Ohio, and Virginia residents aged ≥16 years were obtained and reviewed. Each employed patient was classified into one of 23 major occupational groups using the 2010 Standard Occupational Classification (SOC) system.* Risk ratios (RR) and 95% confidence intervals (CI) for associations between each occupational group and each disease were calculated to identify occupations potentially at increased risk, contrasting each group with all other occupations. In 2014, a total of 2,977 campylobacteriosis and 2,259 salmonellosis cases were reported. Among the 1,772 (60%) campylobacteriosis and 1

10 CFR Appendix D to Part 835 - Surface Contamination Values

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Surface Contamination Values D Appendix D to Part 835 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Pt. 835, App. D Appendix D to Part 835—Surface Contamination Values The data presented in appendix D are to be used in identifying the need for...

10 CFR Appendix D to Part 835 - Surface Contamination Values

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Surface Contamination Values D Appendix D to Part 835 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Pt. 835, App. D Appendix D to Part 835—Surface Contamination Values The data presented in appendix D are to be used in identifying the need for...

10 CFR Appendix D to Part 835 - Surface Contamination Values

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Surface Contamination Values D Appendix D to Part 835 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Pt. 835, App. D Appendix D to Part 835—Surface Contamination Values The data presented in appendix D are to be used in identifying the need for...

[Re-analysis of occupational hazards in foundry].

PubMed

Zhang, Min; Qi, Cheng; Chen, Wei-Hong; Lu, Yang; Du, Xie-Yi; Li, Wen-Jie; Meng, Chuan-San

2010-04-01

To analyze systematically the characteristics of occupational hazards in the foundry, and provide precise data for epidemiology studies and control of occupational hazards in the foundry. Data of airborne dust, chemical occupational hazards and physical occupational agents in environment in the foundry from 1978 to 2008 were dynamically collected. Mean concentration and intensity (geometric mean) of occupational hazards were calculated by job in different years. Main occupational hazards in the foundry were silica, metal fume, noise and heat stress. Silica existed in all of main jobs. The mean concentration of silica before 1986 was an extremely high level of 8.6 mg/m(3), and then remarkably dropped after 1986, with the level of 2.4 mg/m(3) from 1986 to 1989, 2.7 mg/m(3) from 1990 to 2002 and 2.7 mg/m(3) from 2003 to 2008. The trend of silica concentrations by job was consistent with that in general. Silica concentrations among jobs were significantly different, with highest level in melting (4.4 mg/m(3)), followed by cast shakeout and finishing (3.4 mg/m(3)), pouring (3.4 mg/m(3)), sand preparation (2.4 mg/m(3)), moulding (2.1 mg/m(3)) and core-making (1.7 mg/m(3)). Concentration of respirable dust in pouring was highest (2.76 mg/m(3)), followed by cast shakeout and finishing (1.14 mg/m(3)). Mean concentration of asbestos dust in melting was a relative high level of 2.0 mg/m(3). In core-making and sand preparation, there existed emission production of adhesive, with mean concentrations as followed, ammonia (5.84 mg/m(3)), formaldehyde (0.60 mg/m(3)), phenol (1.73 mg/m(3)) and phenol formaldehyde resin (1.3 mg/m(3)) also existed. Benzene and its homologues existed in cast shakeout and finishing, and the level of benzene, toluene, xylene was 0.2 mg/m(3), 0.1 mg/m(3) and 1.3 mg/m(3), respectively. In pouring and melting, there existed chemical occupational hazards, including benzo(a) pyrene, metal fume (lead, cadmium, manganese, nickel, chromium) and gas

Implications of matrix diffusion on 1,4-dioxane persistence at contaminated groundwater sites.

PubMed

Adamson, David T; de Blanc, Phillip C; Farhat, Shahla K; Newell, Charles J

2016-08-15

Management of groundwater sites impacted by 1,4-dioxane can be challenging due to its migration potential and perceived recalcitrance. This study examined the extent to which 1,4-dioxane's persistence was subject to diffusion of mass into and out of lower-permeability zones relative to co-released chlorinated solvents. Two different release scenarios were evaluated within a two-layer aquifer system using an analytical modeling approach. The first scenario simulated a 1,4-dioxane and 1,1,1-TCA source zone where spent solvent was released. The period when 1,4-dioxane was actively loading the low-permeability layer within the source zone was estimated to be <3years due to its high effective solubility. While this was approximately an order-of-magnitude shorter than the loading period for 1,1,1-TCA, the mass of 1,4-dioxane stored within the low-permeability zone at the end of the simulation period (26kg) was larger than that predicted for 1,1,1-TCA (17kg). Even 80years after release, the aqueous 1,4-dioxane concentration was still several orders-of-magnitude higher than potentially-applicable criteria. Within the downgradient plume, diffusion contributed to higher concentrations and enhanced penetration of 1,4-dioxane into the low-permeability zones relative to 1,1,1-TCA. In the second scenario, elevated 1,4-dioxane concentrations were predicted at a site impacted by migration of a weak source from an upgradient site. Plume cutoff was beneficial because it could be implemented in time to prevent further loading of the low-permeability zone at the downgradient site. Overall, this study documented that 1,4-dioxane within transmissive portions of the source zone is quickly depleted due to characteristics that favor both diffusion-based storage and groundwater transport, leaving little mass to treat using conventional means. Furthermore, the results highlight the differences between 1,4-dioxane and chlorinated solvent source zones, suggesting that back diffusion of 1,4

Occupational exposure to Aspergillus by swine and poultry farm workers in Portugal.

PubMed

Sabino, R; Faísca, V M; Carolino, E; Veríssimo, C; Viegas, C

2012-01-01

Aspergillus is among a growing list of allergens that aggravate asthmatic responses. Significant pulmonary pathology is associated with Aspergillus-induced allergic and asthmatic lung disease. Environments with high levels of exposure to fungi are found in animal production facilities such as for swine and poultry, and farmers working with these are at increased risk for occupational respiratory diseases. Seven Portuguese poultry and seven swine farms were analyzed in order to estimate the prevalence, amount, and distribution of Aspergillus species, as well as to determine the presence of clinical symptoms associated with asthma and other allergy diseases in these highly contaminated settings. From the collected fungal isolates (699), an average incidence of 22% Aspergillus was detected in poultry farms, while the prevalence at swine farms was 14%. The most frequently isolated Aspergillus species were A. versicolor, A. flavus, and A. fumigatus. In poultry farms, A. flavus presented the highest level of airborne spores (>2000 CFU/m³), whereas in swine farms the highest was A. versicolor, with an incidence fourfold greater higher than the other mentioned species. Eighty workers in these settings were analyzed, ranging in age from 17 to 93 yr. The potentially hazardous exposure of poultry workers to mold allergens using sensitization markers was evaluated. Although no significant positive association was found between fungal contamination and sensitization to fungal antigens, a high incidence of respiratory symptoms in professionals without asthma was observed, namely, wheezing associated with dyspnea (23.8%) and dyspnea after strenuous activities (12.3%), suggesting underdiagnosed respiratory disturbances. Further, 32.5% of all exposed workers noted an improvement of respiratory ability during resting and holidays. From all the analyzed workers, seven were previously diagnosed with asthma and four reported the first attack after the age of 40 yr, which may be

The metabolism of 14C-cyclohexylamine in mice and two strains of rat.

PubMed

Roberts, A; Renwick, A G

1985-06-01

After administration of 14C-cyclohexylamine (35-500 mg/kg) to male mice and rats, 80% of the dose of 14C was excreted in the urine, mostly within the first 24 h after dosing. In Wistar rats, 7-9% of the 14C in the 0-24 h urine was present as cis-4-aminocyclohexanol, with a similar amount as the corresponding 3-isomers. In the DA rat, only 1-2% of the 14C, and in mouse less than 1% of the 14C was present in the urine as aminocyclohexanols; unchanged cyclohexylamine accounted for about 95% of the activity. The extent of metabolism was not affected by either dose or route of administration. The species differences in metabolism may be implicated in the differences in toxicity during chronic high-dose administration.

Fate of sulfamethoxazole, 4-nonylphenol, and 17β-estradiol in groundwater contaminated by wastewater treatment plant effluent

USGS Publications Warehouse

Barber, Larry B.; Keefe, Steffanie H.; LeBlanc, Denis R.; Bradley, Paul M.; Chapelle, Francis H.; Meyer, Michael T.; Loftin, Keith A.; Koplin, Dana W.; Rubio, Fernando

2009-01-01

Organic wastewater contaminants (OWCs) were measured in samples collected from monitoring wells located along a 4.5-km transect of a plume of groundwater contaminated by 60 years of continuous rapid infiltration disposal of wastewater treatment plant effluent. Fifteen percent of the 212 OWCs analyzed were detected, including the antibiotic sulfamethoxazole (SX), the nonionic surfactant degradation product 4-nonylphenol (NP), the solvent tetrachloroethene (PCE), and the disinfectant 1,4-dichlorobenzene (DCB). Comparison of the 2005 sampling results to data collected from the same wells in 1985 indicates that PCE and DCB are transported more rapidly in the aquifer than NP, consistent with predictions based on compound hydrophobicity. Natural gradient in situ tracer experiments were conducted to evaluate the subsurface behavior of SX, NP, and the female sex hormone 17β-estradiol (E2) in two oxic zones in the aquifer: (1) a downgradient transition zone at the interface between the contamination plume and the overlying uncontaminated groundwater and (2) a contaminated zone located beneath the infiltration beds, which have not been loaded for 10 years. In both zones, breakthrough curves for the conservative tracer bromide (Br−) and SX were nearly coincident, whereas NP and E2 were retarded relative to Br− and showed mass loss. Retardation was greater in the contaminated zone than in the transition zone. Attenuation of NP and E2 in the aquifer was attributed to biotransformation, and oxic laboratory microcosm experiments using sediments from the transition and contaminated zones show that uniform-ring-labeled 14C 4-normal-NP was biodegraded more rapidly (30−60% recovered as 14CO2 in 13 days) than 4-14C E2 (20−90% recovered as 14CO2in 54 days). There was little difference in mineralization potential between sites.

Intracavity optogalvanic spectroscopy. An analytical technique for 14C analysis with subattomole sensitivity.

PubMed

Murnick, Daniel E; Dogru, Ozgur; Ilkmen, Erhan

2008-07-01

We show a new ultrasensitive laser-based analytical technique, intracavity optogalvanic spectroscopy, allowing extremely high sensitivity for detection of (14)C-labeled carbon dioxide. Capable of replacing large accelerator mass spectrometers, the technique quantifies attomoles of (14)C in submicrogram samples. Based on the specificity of narrow laser resonances coupled with the sensitivity provided by standing waves in an optical cavity and detection via impedance variations, limits of detection near 10(-15) (14)C/(12)C ratios are obtained. Using a 15-W (14)CO2 laser, a linear calibration with samples from 10(-15) to >1.5 x 10(-12) in (14)C/(12)C ratios, as determined by accelerator mass spectrometry, is demonstrated. Possible applications include microdosing studies in drug development, individualized subtherapeutic tests of drug metabolism, carbon dating and real time monitoring of atmospheric radiocarbon. The method can also be applied to detection of other trace entities.

14 CFR Appendix C to Part 141 - Instrument Rating Course

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Instrument Rating Course C Appendix C to...) SCHOOLS AND OTHER CERTIFICATED AGENCIES PILOT SCHOOLS Pt. 141, App. C Appendix C to Part 141—Instrument...: (a) Instrument—airplane. (b) Instrument—helicopter. (c) Instrument—powered-lift. 2. Eligibility for...

Fate of 14C-acrylamide in roasted and ground coffee during storage.

PubMed

Baum, Matthias; Böhm, Nadine; Görlitz, Jessica; Lantz, Ingo; Merz, Karl Heinz; Ternité, Rüdiger; Eisenbrand, Gerhard

2008-05-01

Acrylamide (AA) is formed during heating of carbohydrate rich foods in the course of the Maillard reaction. AA has been classified as probably carcinogenic to humans. Storage experiments with roasted coffee have shown that AA levels decrease depending on storage time and temperature. In the present study the fate of AA lost during storage of roasted and ground (R&G) coffee was studied, using 14C-labeled AA as radiotracer. Radiolabel was measured in coffee brew, filter residue, and volatiles. In the brew, total (14)C-label decreased during storage of R&G coffee, while activity in the filter residue built up concomitantly. [2,3-14C]-AA (14C-AA) was the only 14C-related water extractable low molecular compound in the brew detected by radio-HPLC. No formation of volatile 14C-AA-related compounds was detected during storage and coffee brewing. Close to 90% of the radiolabel in the filter residue (spent R&G coffee, spent grounds) remained firmly bound to the matrix, largely resisting extraction by aqueous ammonia, ethyl acetate, chloroform, hexane, and sequential polyenzymatic digest. Furanthiols, which are abundant as aroma components in roasted coffee, have not been found to be involved in the formation of covalent AA adducts and thus do not contribute substantially to the decrease of AA during storage.

Translocation of 14-C in ponderosa pine seedlings

Treesearch

Robert R. Ziemer

1971-01-01

The movement of 14-C from the old needles to the roots, and later to the new needles, was measured in 2-year-old ponderosa pine seedlings. The seedlings were in one of three growth stages at the time of the feeding of 14-CO-2: 9 days before spring bud break with no root activity; 7 days before spring bud break with high root activity; and 7 days after spring bud break...

Potential for intrinsic bioremediation of a DNT-contaminated aquifer

USGS Publications Warehouse

Bradley, P.M.; Chapelle, F.H.; Landmeyer, J.E.; Schumacher, J.G.

1997-01-01

Microorganisms indigenous to a shallow aquifer, which underlies an explosives-contaminated site, mineralized 28% of [U-ring-14C] 2,4–dinitrotoluene to 14CO2 within 28 days under aerobic conditions. Approximately 20% of added 2,4–dinitrotoluene remained undegraded at the end of the incubation while approximately 22% and 6% were transformed to 4–amino-2–nitrotoluene and 2–amino-4–nitrotoluene, respectively. In aquifer microcosms containing 2,6–dinitrotoluene, approximately 67% of the substrate remained undegraded and approximately 14% was transformed to 2–amino-6–nitrotoluene. The radiolabeled study indicated that about 8% of the 2,6–dinotrotoluene was mineralized to CO2. The demonstrated degradation and subsequent mineralization of dinitrotoluene compounds by aquifer microorganisms are consistent with the decline in dissolved dinitrotoluene concentrations observed along the general ground-water flowpath at the site. The results indicate that intrinsic bioremediation may be a viable alternative for remediating contaminated ground water at this site.

Laboratory procedure for estimating residue dynamics of xenobiotic contaminants in a freshwater food chain

USGS Publications Warehouse

Johnson, B. Thomas

1980-01-01

A laboratory method of measuring the accumulation, transfer, elimination, and degradation of xenobiotic contaminants is described for organisms in a freshwater food chain (microorganisms, filter-feeder, and fish). A flow-through diluter-system, 14C-labeled contaminants, gas and thin-layer chromatography, autoradiography, and liquid scintillation spectrometry are used in making residue determinations. Accumulation factors and various index values are developed for measuring and estimating potential accumulation of xenobiotic contaminants by aquatic organisms. The laboratory procedure is economical, simple, reproducible, and ecologically relevant.

Fate of ( sup 14 C)monolinuron in potatoes and soil under outdoor conditions

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

Freitag, D.; Scheunert, I.

1990-12-01

(phenyl-{sup 14}C)Monolinuron was applied (2.5 and 1.9 kg/ha) to the soil surface of an outdoor lysimeter in two successive years: then, potatoes were grown. Total recovery of {sup 14}C in soil, plants, and leached water was about 55% (of {sup 14}C applied) after the first growing period and about 43% after the second growing period. Radioactivity in soil contained 77.1% (based on total {sup 14}C recovered in soil) bound residues, 15% monolinuron, and the following conversion products: N-(4-hydroxyphenyl)-N'-methoxy-N'-methylurea, N-(4-chlorophenyl)-N'-methylurea. N-(4-chlorophenyl)methylcarbamate, N-(4-chlorophenyl)-N-methyl-methylcarbamate, and 4-chloroformanilide. The leachate contained 0.8% (based on total {sup 14}C recovered in leachate) N-(4-hydroxyphenyl)-N'-methoxy-N'-methylurea. Potato plants contained 0.106more » mg/kg radioactive residues in peeled tubers after one growing period and 15.94 mg/kg in the tops; after two growing periods, peeled tubers contained 0.091 mg/kg and tops contained 18.87 mg/kg radioactive residues. These residues consisted of bound {sup 14}C (57.9% of total {sup 14}C recovered in plants), N-(4-hydroxyphenyl)-N'-methoxy-N'-methylurea, N-(4-chlorophenyl)-N'-methylurea, N-(4-chlorophenyl)methylcarbamate, N-(4-chlorophenyl)-N-methyl-methylcarbamate, and 4,4'-dichlorozobenzene.« less

Three new HLA-C alleles (HLA-C*14:02:13, HLA-C*15:72 and HLA-C*15:74) in Saudi bone marrow donors.

PubMed

Fakhoury, H A; Jawdat, D; Alaskar, A S; Al Jumah, M; Cereb, N; Hajeer, A H

2015-10-01

Three new HLA-C alleles were identified by sequence-based typing method (SBT) in donors for the Saudi Bone Marrow Donor Registry (SBMDR). HLA-C*14:02:13 differs from HLA-C*14:02:01 by a silent G to A substitution at nucleotide position 400 in exon 2, where lysine at position 66 remains unchanged. HLA-C*15:72 differs from HLA-C*15:22 by a nonsynonymous C to A substitution at nucleotide position 796 in exon 3, resulting in an amino acid change from phenylalanine to leucine at position 116. HLA-C*15:74 differs from HLA-C*15:08 by a nonsynonymous C to T substitution at nucleotide position 914 in exon 3, resulting in an amino acid change from arginine to tryptophan at position 156. © 2015 John Wiley & Sons Ltd.

Forensic applications of 14C at CIRCE

NASA Astrophysics Data System (ADS)

Marzaioli, F.; Fiumano, V.; Capano, M.; Passariello, I.; Cesare, N. De.; Terrasi, F.

2011-12-01

The decreasing trend of the radiocarbon pulse produced during the atmospheric tests of nuclear weapons (bomb-carbon) coupled with high sensitivity accelerator mass spectrometry (AMS) measurements, drastically increased the precision of radiocarbon age determinations since the second part of the sixties, allowing the application of radiocarbon AMS to a wide range of studies previously not directly involving conventional radiocarbon dating (i.e. food authenticity, forensic, biochemistry). In the framework of authenticity evaluation of artworks, high precision radiocarbon ( 14C) AMS measurements (Δ R/ R < 0.3%) reduce the conventional uncertainty of the dating to few decades, allowing precise age estimation of materials containing carbon (C). The Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) during its activity on AMS 14C dating achieved high precision measurements opening the opportunity to these kinds of applications. This paper presents the main results obtained from radiocarbon measurements on a set of bone samples analyzed for the determination of the post-mortem interval in the framework of an unsolved case investigated by the Rome prosecutor office. The chronological characterization of the wooden support of the "Acerenza portrait" is also presented with the aim to evaluate its age and to further investigate the possibility to attribute this artwork to Leonardo da Vinci. Bomb- 14C dating on the lipid and collagen fractions of bones allows the evaluation of the year of the death of the individuals by means of ad hoc calibration data sheet with the typical few years precision and difference between collagen apparent age and the year of death appeared in agreement with the age of one individual estimated by dating of tooth collagen. Conventional radiocarbon dating on both wood and wood extracted cellulose leads to an estimation of the portrait wood board age (2σ) of 1459-1524 AD (57% relative probability), 1571-1631 AD interval (42

Antihalo effects on reaction cross sections for C14,15,16 isotopes

NASA Astrophysics Data System (ADS)

Matsumoto, Takuma; Yahiro, Masanobu

2014-10-01

We study antihalo effects on reaction cross sections σR for C14,15,16 scattering from a C12 target at 83 MeV/nucleon, using the g-matrix double-folding model. C15 is described by the 14C+n two-body model that reproduces the measured large s-wave spectroscopic factor, i.e., the shell inversion that the 1s1/2 orbital is lower than the 0d5/2 orbital in energy. C16 is described by the 14C+n+n three-body model with the phenomenological three-body force (3BF) that explains the measured small s-wave spectroscopic factor. The 3BF allows the single-particle energies of the 14C+n subsystem to depend on the position r of the second neutron from the center of mass of the subsystem. The 1s1/2 orbital is lower than the 0d5/2 orbital for large r, but the shell inversion is restored for small r. Antihalo effects due to the "partial shell inversion" make σR for C16 smaller than that for C15. We also investigate projectile breakup effects on the mass-number dependence of σR with the continuum-discretized coupled-channel method.

Use of Ramped PyrOx 14C dating to simultaneously determine the organic carbon age and carbonate material age of Antarctic marginal sediments

NASA Astrophysics Data System (ADS)

Reese, D.; DeCesare, M.; Subt, C.; Bart, P. J.; Wellner, J. S.; Rosenheim, B. E.

2016-12-01

Chronicling deglaciation rates and style in Antarctic margin sediment is difficult because of low preservation/deposition of carbonate foraminiferal tests as well as incorporation of pre-aged organic carbon from carbonaceous rocks. When carbonates for radiocarbon dating are absent, acid-insoluble organic matter (AIOM) 14C dates are often used as an alternative and providing reliable chronologies in some locations. Results obtained by this method can cause difficulties such as false age reversals and ambiguity due to contamination with pre-aged carbon (Rosenheim et. al., 2008; Subt et al., 2016). Ramped PyrOx 14C dating has exploited the higher thermochemical stability of pre-aged carbon to separate carbon dating to the time of sediment deposition, and recently has produced chronologies similar to foraminifera-based chronologies (Subt et al., 2016). Samples for Ramped PyrOx 14C dating have generally been treated with acid to remove carbonates, and thus some acid soluble organic matter. In an effort to minimize the alteration of the organic matter, we apply Ramped PyrOx 14C dating to samples that have been both treated with 1N HCl and left untreated. Untreated samples display a characteristic large, sharp peak at higher temperatures than pyrolysis of organic matter that we interpret as carbonate decomposition. These carbonate decomposition peaks are characteristically sharp and occur at higher temperatures than the maximum evolution of CO2 from the organic matter in the sample. We isolated these peaks for comparison between known carbonate ages from picked foraminifera and low-temperature Ramped PyrOx splits from acid treated samples. We will discuss the treatment of the suite of 14C ages with reconciliation of two dating methods in mind. Ultimately, this approach offers promise for a single treatment of Antarctic margin sediments that provides chronologies from both carbonate and organic material.

Betaine accumulation and (/sup 14/C)formate metabolism in water-stressed barley leaves

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

Hanson, A.D.; Nelsen, C.E.

1978-01-01

Barley (Hordeum vulgare L.) plants at the three-leaf stage were water-stressed by flooding the rooting medium with polyethylene glycol 6000 with an osmotic potential of -19 bars, or by withholding water. While leaf water potential fell and leaf kill progressed, the betaine (trimethylglycine) content of the second leaf blade rose from about 0.4 micromole to about 1.5 micromoles in 4 days. The time course of betaine accumulation resembled that of proline. Choline levels in unstressed second leaf blades were low (<0.1 micromole per blade) and remained low during water stress. Upon relief of stress, betaine-like proline-remained at a high concentrationmore » in drought-killed leaf zones, but betaine did not disappear as rapidly as proline during recovery. When (methyl-/sup 14/C)choline was applied to second leaf blades of intact plants in the growth chamber, water-stressed plants metabolized 5 to 10 times more /sup 14/C label to betaine than control plants during 22 hours. When infiltrated with tracer quantities of (/sup 14/C)formate and incubated for various times in darkness or light, segments cut from water-stressed leaf blades incorporated about 2- to 10-fold more /sup 14/C into betaine than did segments from unstressed leaves. In segments from stressed leaves incubated with (/sup 14/C)formate for about 18 hours in darkness, betaine was always the principal /sup 14/C-labeled soluble metabolite. This /sup 14/C label was located exclusively in the N-methyl groups of betaine; thus, reducing equivalents were available in stressed leaves for the reductive steps of methyl group biosynthesis from formate. Incorporation of /sup 14/C from formate into choline was also increased in stressed leaf tissue, but choline was not a major product formed from (/sup 14/C)formate. These results are consistent with a net de novo synthesis of betaine from 1- and 2-carbon precursors during water stress and indicate that the betaine so accumulated may be a metabolically inert end product.« less

Rapid analysis method for the determination of 14C specific activity in irradiated graphite

PubMed Central

Remeikis, Vidmantas; Lagzdina, Elena; Garbaras, Andrius; Gudelis, Arūnas; Garankin, Jevgenij; Juodis, Laurynas; Duškesas, Grigorijus; Lingis, Danielius; Abdulajev, Vladimir; Plukis, Artūras

2018-01-01

14C is one of the limiting radionuclides used in the categorization of radioactive graphite waste; this categorization is crucial in selecting the appropriate graphite treatment/disposal method. We propose a rapid analysis method for 14C specific activity determination in small graphite samples in the 1–100 μg range. The method applies an oxidation procedure to the sample, which extracts 14C from the different carbonaceous matrices in a controlled manner. Because this method enables fast online measurement and 14C specific activity evaluation, it can be especially useful for characterizing 14C in irradiated graphite when dismantling graphite moderator and reflector parts, or when sorting radioactive graphite waste from decommissioned nuclear power plants. The proposed rapid method is based on graphite combustion and the subsequent measurement of both CO2 and 14C, using a commercial elemental analyser and the semiconductor detector, respectively. The method was verified using the liquid scintillation counting (LSC) technique. The uncertainty of this rapid method is within the acceptable range for radioactive waste characterization purposes. The 14C specific activity determination procedure proposed in this study takes approximately ten minutes, comparing favorably to the more complicated and time consuming LSC method. This method can be potentially used to radiologically characterize radioactive waste or used in biomedical applications when dealing with the specific activity determination of 14C in the sample. PMID:29370233

Rapid analysis method for the determination of 14C specific activity in irradiated graphite.

PubMed

Remeikis, Vidmantas; Lagzdina, Elena; Garbaras, Andrius; Gudelis, Arūnas; Garankin, Jevgenij; Plukienė, Rita; Juodis, Laurynas; Duškesas, Grigorijus; Lingis, Danielius; Abdulajev, Vladimir; Plukis, Artūras

2018-01-01

14C is one of the limiting radionuclides used in the categorization of radioactive graphite waste; this categorization is crucial in selecting the appropriate graphite treatment/disposal method. We propose a rapid analysis method for 14C specific activity determination in small graphite samples in the 1-100 μg range. The method applies an oxidation procedure to the sample, which extracts 14C from the different carbonaceous matrices in a controlled manner. Because this method enables fast online measurement and 14C specific activity evaluation, it can be especially useful for characterizing 14C in irradiated graphite when dismantling graphite moderator and reflector parts, or when sorting radioactive graphite waste from decommissioned nuclear power plants. The proposed rapid method is based on graphite combustion and the subsequent measurement of both CO2 and 14C, using a commercial elemental analyser and the semiconductor detector, respectively. The method was verified using the liquid scintillation counting (LSC) technique. The uncertainty of this rapid method is within the acceptable range for radioactive waste characterization purposes. The 14C specific activity determination procedure proposed in this study takes approximately ten minutes, comparing favorably to the more complicated and time consuming LSC method. This method can be potentially used to radiologically characterize radioactive waste or used in biomedical applications when dealing with the specific activity determination of 14C in the sample.

Bioavailability of TNT residues in composts of TNT-contaminated soil

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

Palmer, W.G.; Beaman, J.R.; Walters, D.M.

1997-10-01

Composting is being explored as a means to remediate 2,4,6-trinitrotoluene (TNT) contaminated soils. This process appears to modify TNT and to bind it to organic matter. The health hazards associated with dusts generated from such materials cannot be predicted without knowing if the association between TNT residues and compost particulate is stable in biological systems. To address this question, single doses of [{sup 14}C]-TNT, soil spiked with [{sup 14C]-TNT, or compost generated with [{sup 14}C]-TNT-spiked soils were administered to rats by intratracheal instillation. The appearance of {sup 14}C in urine and tissues was taken as an indication of the bioavailabilitymore » of TNT residues from compost particles. In rats instilled with neat [{sup 14}C]-TNT, about 35% of the {sup 14}C dose appeared in urine within 3 d. The {sup 14}C excreted in urine by these rats decreased rapidly thereafter, and was undetectable by 4 wk after treatment. Similar results were obtained with soil-treated rats. In contrast, after treatment with [{sup 14}C]-TNT-labeled compost, only 2.3% of the total {sup 14}C dose appeared in urine during the first 3 d. Low levels of {sup 14}C continued to be excreted in urine from compost-treated rats for more than 6 mo, and the total amount of {sup 14}C in urine was comparable to that in TNT-treated animals. Determination of the radiolabel in tissues showed that {sup 14}C accumulated in the kidneys of rats treated with labeled compost but not in rats treated with [{sup 14}C]-TNT or [{sup 14}C]-TNT-spiked soil. These results indicate that the association between TNT and particulate matter in compost is not stable when introduced into the lungs. Accumulation of {sup 14}C in kidneys suggests the presence of a unique TNT residue in compost-treated rats. The rate of excretion and tissue disposition of {sup 14}}C in rats treated with TNT-spiked soil indicate that TNT in soil is freely available in the lungs. 12 refs., 4 figs., 1 tab.« less

AMS studies of the long-term turnover of 14C-labelled fat in man

NASA Astrophysics Data System (ADS)

Gunnarsson, M.; Mattsson, S.; Stenström, K.; Leide-Svegborn, S.; Erlandsson, B.; Faarinen, M.; Hellborg, R.; Kiisk, M.; Nilsson, L.-E.; Nosslin, B.; Persson, P.; Skog, G.; Åberg, M.

2000-10-01

To estimate the biokinetics of 14C-labelled fatty acids and the associated radiation absorbed dose to man, long-term retention of 14C from oral intake of glycerol tri[1- 14C]oleate (triolein) has been studied using accelerator mass spectrometry (AMS). As a complement to earlier reported data for three individuals, we present here results for one person from measurements up to 4.6 yr after administration, now also including 14C-levels in fat, muscle and bone. In this subject, a total of 44% of the administered activity was recovered in the exhaled air. Fasting increased the exhalation of 14C. The "excess" 14CO2 due to fasting had a half-life of about 400 d. AMS measurements on fat, muscle and bone biopsies taken from the same subject 4.5 yr after ingestion indicated that a small fraction of the administered activity was still present in fat. Also, bone tissue had a higher 14C specific activity than the current environmental level. No significantly increased level was found in the muscle sample.

Contaminant Interactions and Biological Effects of Single-walled Carbon Nanotubes in a Benthic Estuarine System

NASA Astrophysics Data System (ADS)

Parks, Ashley Nicole

The fate, bioavailability, bioaccumulation and toxicity of single-walled carbon nanotubes (SWNT) have not been extensively studied to date. Pristine SWNT are highly hydrophobic and have been shown to strongly associate with natural particulate matter in aquatic environments. In light of this, I have focused my research to examine the influence of sediment and food exposure routes on bioavailability, bioaccumulation, and toxicity of structurally diverse SWNT in several ecologically-important marine invertebrate species. No significant mortality was observed in any organism at concentrations up to 1000 mg/kg. Evidence of biouptake after ingestion was observed for pristine semiconducting SWNT using NIRF spectroscopy and for oxidized 14C-SWNT using liquid scintillation counting. After a 24 hour depuration period, the pristine semiconducting SWNT were eliminated from organisms to below the method detection limit (5 microg/mL), and the 14C-SWNT body burden was decreased by an order of magnitude to a bioaccumulation factor (BAF) of <0.01. Neither pristine SWNT nor oxidized 14C-SWNT caused environmentally relevant toxicity or bioaccumulation in benthic invertebrates. Overall, the SWNT were not bioavailable and appear to associate with the sediment. In addition to investigating the toxicity and bioaccumulation of SWNT as an independent toxicant, it is important to consider how they will interact with other contaminants in the environment (i.e., increase or decrease toxicity and bioaccumulation of co-contaminants, alter the environmental transport of co-contaminants, induce degradation of co-contaminants, etc.). I wanted to investigate the effects of SWNT on a complex mixture of contaminants already present in a natural system. New Bedford Harbor (NBH) sediment, which is contaminated with polychlorinated biphenyls (PCBs), was amended with pristine SWNT to determine if the presence of SWNT would mitigate the toxicity and bioaccumulation of the PCBs in deposit

14 CFR Appendix C to Part 29 - Icing Certification

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Icing Certification C Appendix C to Part 29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... maximum icing) is defined by the variables of the cloud liquid water content, the mean effective diameter...

14 CFR Appendix C to Part 29 - Icing Certification

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Icing Certification C Appendix C to Part 29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... maximum icing) is defined by the variables of the cloud liquid water content, the mean effective diameter...

14 CFR Appendix C to Part 29 - Icing Certification

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Icing Certification C Appendix C to Part 29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... maximum icing) is defined by the variables of the cloud liquid water content, the mean effective diameter...

14 CFR Appendix C to Part 29 - Icing Certification

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Icing Certification C Appendix C to Part 29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... maximum icing) is defined by the variables of the cloud liquid water content, the mean effective diameter...

A ternary age-mixing model to explain contaminant occurrence in a deep supply well

USGS Publications Warehouse

Jurgens, Bryant; Bexfield, Laura M.; Eberts, Sandra

2014-01-01

The age distribution of water from a public-supply well in a deep alluvial aquifer was estimated and used to help explain arsenic variability in the water. The age distribution was computed using a ternary mixing model that combines three lumped parameter models of advection-dispersion transport of environmental tracers, which represent relatively recent recharge (post- 1950s) containing volatile organic compounds (VOCs), old intermediate depth groundwater (about 6500 years) that was free of drinking-water contaminants, and very old, deep groundwater (more than 21,000 years) containing arsenic above the USEPA maximum contaminant level of 10 µg/L. The ternary mixing model was calibrated to tritium, chloroflorocarbon-113, and carbon-14 (14C) concentrations that were measured in water samples collected on multiple occasions. Variability in atmospheric 14C over the past 50,000 years was accounted for in the interpretation of 14C as a tracer. Calibrated ternary models indicate the fraction of deep, very old groundwater entering the well varies substantially throughout the year and was highest following long periods of nonoperation or infrequent operation, which occured during the winter season when water demand was low. The fraction of young water entering the well was about 11% during the summer when pumping peaked to meet water demand and about 3% to 6% during the winter months. This paper demonstrates how collection of multiple tracers can be used in combination with simplified models of fluid flow to estimate the age distribution and thus fraction of contaminated groundwater reaching a supply well under different pumping conditions.

A Ternary Age-Mixing Model to Explain Contaminant Occurrence in a Deep Supply Well

PubMed Central

Jurgens, Bryant C; Bexfield, Laura M; Eberts, Sandra M

2014-01-01

The age distribution of water from a public-supply well in a deep alluvial aquifer was estimated and used to help explain arsenic variability in the water. The age distribution was computed using a ternary mixing model that combines three lumped parameter models of advection-dispersion transport of environmental tracers, which represent relatively recent recharge (post-1950s) containing volatile organic compounds (VOCs), old intermediate depth groundwater (about 6500 years) that was free of drinking-water contaminants, and very old, deep groundwater (more than 21,000 years) containing arsenic above the USEPA maximum contaminant level of 10 µg/L. The ternary mixing model was calibrated to tritium, chloroflorocarbon-113, and carbon-14 (14C) concentrations that were measured in water samples collected on multiple occasions. Variability in atmospheric 14C over the past 50,000 years was accounted for in the interpretation of 14C as a tracer. Calibrated ternary models indicate the fraction of deep, very old groundwater entering the well varies substantially throughout the year and was highest following long periods of nonoperation or infrequent operation, which occured during the winter season when water demand was low. The fraction of young water entering the well was about 11% during the summer when pumping peaked to meet water demand and about 3% to 6% during the winter months. This paper demonstrates how collection of multiple tracers can be used in combination with simplified models of fluid flow to estimate the age distribution and thus fraction of contaminated groundwater reaching a supply well under different pumping conditions. PMID:24597520

A simplified In Situ cosmogenic 14C extraction system

USGS Publications Warehouse

Pigati, J.S.; Lifton, N.A.; Timothy, Jull A.J.; Quade, Jay

2010-01-01

We describe the design, construction, and testing of a new, simplified in situ radiocarbon extraction system at the University of Arizona. Blank levels for the new system are low ((234 ?? 11) ?? 103 atoms (1 ??; n = 7)) and stable. The precision of a given measurement depends on the concentration of 14C, but is typically <5% for concentrations of 100 ?? 103 atoms g-1 or more. The new system is relatively small and easy to construct, costs significantly less than the original in situ 14C extraction system at Arizona, and lends itself to future automation. ?? 2010 by the Arizona Board of Regents on behalf of the University of Arizona.

[Association between occupational psychological stress and metabolic syndrome].

PubMed

Liu, Herong; Song, Hui; Tian, Rulong; Chen, Lijun; Zhang, Wei; Qiang, Yan

2015-02-01

.05). The relative risks of MS in the people with moderate stress exposure were 2.325 and 2.331 times those in the people with mild stress exposure before and after adjustment for age, gender, education level, marriage status, smoking, and drinking, and the relative risks for MS in the people with severe stress exposure were 3.000 and 3.126 times those in the people with mild stress exposure. There were significant differences in the detection rates of abdominal obesity, high TG, low HDL-C, hypertension, hyperglycemia, and diabetes between the sub-groups with different stress levels in the MS group (χ² = 17.636, 8.514, 14.640, 14.280, and 33.323, P < 0.01). The results of multivariate conditional logistic regression analysis showed that the risk factors for MS were SBP, TG, LDL-C, UA, BMI, fasting blood glucose, family history of hypertension, family history of diabetes, and the level of psychological stress in Ningxia, and the protective factor for MS was HDL-C. The occupational psychological stress is closely associated with MS, and it is an environmental risk factor for MS. With the increase in the stress level, the detection rates of MS components and the relative risk for MS are significantly increased. And there is no significant difference in the level of occupational psychological stress between the Hui and Han nationality groups.

14 CFR Appendix C to Part 23 - Basic Landing Conditions

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Basic Landing Conditions C Appendix C to... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Pt. 23, App. C Appendix C...) 23.479(a)(2)(ii) 23.481(a)(2) and (b). Vertical component at c. g nW nW nW nW nW. Fore and aft...

14 CFR Appendix C to Part 23 - Basic Landing Conditions

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Basic Landing Conditions C Appendix C to... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Pt. 23, App. C Appendix C...) 23.479(a)(2)(ii) 23.481(a)(2) and (b). Vertical component at c. g nW nW nW nW nW. Fore and aft...

14 CFR Appendix C to Part 23 - Basic Landing Conditions

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Basic Landing Conditions C Appendix C to... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Pt. 23, App. C Appendix C...) 23.479(a)(2)(ii) 23.481(a)(2) and (b). Vertical component at c. g nW nW nW nW nW. Fore and aft...

Occupationally acquired HIV: the vulnerability of health care workers under workers' compensation laws.

PubMed Central

Tereskerz, P M; Jagger, J

1997-01-01

Approximately 800,000 needlesticks and other sharp injuries from contaminated medical devices occur in health care settings each year, of which an estimated 16,000 are contaminated by human immunodeficiency virus (HIV). Health care workers who are occupationally infected by HIV are at risk of being left without workers' compensation coverage. In some states, the definition of an occupational disease is so restrictive that infected health care workers are unlikely to qualify for benefits. For those who are able to meet the definition, compensation is often inadequate. Recourse is also limited by statutory provisions that preclude health care workers from bringing civil suits against their employers. We recommend the amendment of legislation to provide more equitable remedies, including: (1) broadening the definition of occupational disease; (2) eliminating provisions that require a claimant to prove that (a) a specific occupational incident resulted in infection and (b) HIV is not an ordinary disease of life; (3) expanding the time for filing a claim; (4) assuring that lifetime benefits will be provided to the disabled health care worker; and (5) assuring that claims will remain confidential. PMID:9314817

Knowledge of congenital cytomegalovirus (cCMV) among physical and occupational therapists in the United States

PubMed Central

Armstrong-Heimsoth, Amy; Thomas, Jodi

2017-01-01

Congenital cytomegalovirus (cCMV) infections cause more children to have permanent disabilities than Down Syndrome, Fetal Alcohol Syndrome, Spina Bifida, and pediatric HIV/AIDS combined. The risk of infection during pregnancy can be significantly decreased using universal precautions, such as thorough handwashing and cleansing of surfaces and objects that have come into contact with infected body fluids. Children under 3 years of age are commonly asymptomatic excretors of CMV, with the highest viral loads present in saliva. Pediatric therapists have regular close contact with young children, and are thus likely at elevated occupational risk of acquiring CMV. Our objective was to evaluate therapist knowledge of cCMV and its transmission. We recruited American Occupational Therapy Association (AOTA) and American Physical Therapy Association (APTA) members via electronic newsletters and printed flyers from April to September 2015. Participants completed an online, anonymous 24-question survey using Survey Monkey. We compared responses between groups and previously published CMV awareness data using binomial tests of difference of proportions and multiple logistic regression. Our study identified both a low level of therapist awareness and poor demonstrated understanding of cCMV. Self-reported cCMV awareness amongst therapists was greater than awareness in the general population, and equivalent to awareness amongst health care professionals. Whereas 52% of participants self-reported awareness of cCMV, only 18% demonstrated understanding of the behavioral modes of CMV transmission. Fewer therapists reported awareness of cCMV than other, less prevalent conditions. Higher levels of health risk knowledge were associated with greater contact with children. Most participants reported learning about cCMV from the workplace. The knowledge gaps between self-reported awareness of cCMV and demonstrated understanding of modes of transmission described by our results emphasize the

Knowledge of congenital cytomegalovirus (cCMV) among physical and occupational therapists in the United States.

PubMed

Muldoon, Kathleen M; Armstrong-Heimsoth, Amy; Thomas, Jodi

2017-01-01

Congenital cytomegalovirus (cCMV) infections cause more children to have permanent disabilities than Down Syndrome, Fetal Alcohol Syndrome, Spina Bifida, and pediatric HIV/AIDS combined. The risk of infection during pregnancy can be significantly decreased using universal precautions, such as thorough handwashing and cleansing of surfaces and objects that have come into contact with infected body fluids. Children under 3 years of age are commonly asymptomatic excretors of CMV, with the highest viral loads present in saliva. Pediatric therapists have regular close contact with young children, and are thus likely at elevated occupational risk of acquiring CMV. Our objective was to evaluate therapist knowledge of cCMV and its transmission. We recruited American Occupational Therapy Association (AOTA) and American Physical Therapy Association (APTA) members via electronic newsletters and printed flyers from April to September 2015. Participants completed an online, anonymous 24-question survey using Survey Monkey. We compared responses between groups and previously published CMV awareness data using binomial tests of difference of proportions and multiple logistic regression. Our study identified both a low level of therapist awareness and poor demonstrated understanding of cCMV. Self-reported cCMV awareness amongst therapists was greater than awareness in the general population, and equivalent to awareness amongst health care professionals. Whereas 52% of participants self-reported awareness of cCMV, only 18% demonstrated understanding of the behavioral modes of CMV transmission. Fewer therapists reported awareness of cCMV than other, less prevalent conditions. Higher levels of health risk knowledge were associated with greater contact with children. Most participants reported learning about cCMV from the workplace. The knowledge gaps between self-reported awareness of cCMV and demonstrated understanding of modes of transmission described by our results emphasize the

Influence of diesel contamination on the benthic microbial/meiofaunal food web of a Louisiana salt marsh

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

Carman, K.R.; Fleeger, J.W.; Pomarico, S.

The authors studied the influence of diesel-contaminated sediments on the benthic microbial/meiofaunal food web from a Louisiana salt marsh. Diesel-contaminated sediment was added to microcosms (intact cores of marsh mud) in a range of doses, and a suite of microbial and meiofaunal responses were measured over a 28-day period. The authors measured bacterial and microalgal (Chl a) abundance, bacterial and microalgal activity using radiotracers ({sup 14}C-acetate and {sup 14}CO{sub 2}, respectively), meiofaunal grazing on microalgae, meiofaunal community structure, and meiofaunal physiological condition. Preliminary results indicate that diesel-contaminated sediments influence microalgal biomass and activity, as well as the life histories ofmore » benthic copepod species.« less

Airy structure in 16O+14C nuclear rainbow scattering

NASA Astrophysics Data System (ADS)

Ohkubo, S.; Hirabayashi, Y.

2015-08-01

The Airy structure in 16 O +14 C rainbow scattering is studied with an extended double-folding (EDF) model that describes all the diagonal and off-diagonal coupling potentials derived from the microscopic realistic wave functions for 16 O by using a density-dependent nucleon-nucleon force. The experimental angular distributions at EL=132 , 281, and 382.2 MeV are well reproduced by the calculations. By studying the energy evolution of the Airy structure, the Airy minimum around θ =76∘ in the angular distribution at EL=132 MeV is assigned as the second-order Airy minimum A 2 in contrast to the recent literature which assigns it as the third order A 3 . The Airy minima in the 90∘ excitation function is investigated in comparison with well-known 16 O +16 O and 12 C +12 C systems. Evolution of the Airy structure into the molecular resonances with the 16 O +14 C cluster structure in the low-energy region around Ec .m .=30 MeV is discussed. It is predicted theoretically for the first time for a non-4 N 16O +14 C system that Airy elephants in the 90∘ excitation function are present.

Role of higher-multipole deformations in exotic {sup 14}C cluster radioactivity

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

Sawhney, Gudveen; Sharma, Manoj K.; Gupta, Raj K.

2011-06-15

We have studied nine cases of spontaneous emission of {sup 14}C clusters in the ground-state decays of the same number of parent nuclei from the trans-lead region, specifically from {sup 221}Fr to {sup 226}Th, using the preformed cluster model (PCM) of Gupta and collaborators, with choices of spherical, quadrupole deformation ({beta}{sub 2}) alone, and higher-multipole deformations ({beta}{sub 2}, {beta}{sub 3}, {beta}{sub 4}) with cold ''compact'' orientations {theta}{sup c} of decay products. The calculated {sup 14}C cluster decay half-life times are found to be in nice agreement with experimental data only for the case of higher-multipole deformations ({beta}{sub 2}-{beta}{sub 4}) andmore » {theta}{sup c} orientations of cold elongated configurations. In other words, compared to our earlier study of clusters heavier than {sup 14}C, where the inclusion of {beta}{sub 2} alone, with ''optimum'' orientations, was found to be enough to give the best comparison with data, here for {sup 14}C cluster decay the inclusion of higher-multipole deformations (up to hexadecapole), together with {theta}{sup c} orientations, is found to be essential on the basis of the PCM. Interestingly, whereas both the penetration probability and assault frequency work simply as scaling factors, the preformation probability is strongly influenced by the order of multipole deformations and orientations of nuclei. The possible role of Q value and angular-momentum effects are also considered in reference to {sup 14}C cluster radioactivity.« less

Progress, Potential and Pitfalls in the Use of Bomb 14C to Constrain Soil Carbon Dynamics

NASA Astrophysics Data System (ADS)

Baisden, W. T.

2007-12-01

Forty four years have passed since atmospheric testing of thermonuclear weapons injected a major 14C spike into the atmosphere-biosphere-hydrosphere system. The use of bomb 14C, in combination with millennial decay of 14C, remains the most effective empirical tool for constraining rates of carbon (C) cycling in soils at timescales beyond experimental manipulations (>5 years). In the last 20 years, accelerator mass spectrometry has greatly increased the potential and throughput of soil 14C studies. At present, atmospheric Δ14C appears to be stabilizing at more constant values as a result of reinjection of bomb 14C from decadal storage in forests and soils. This means that current and future studies using bomb 14C have different sensitivities and uncertainties compared to those carried out during periods of rapid Δ14C decline such as the 1970s, 80s and 90s. Bomb 14C proves most effective when archived soil samples are available: simply using bulk Δ14C from samples collected at two or more times can surpass single time point Δ14C from soil fractions in providing robust C cycling rates. Of course, measurement of Δ14C in soil fractions from time series samples can significantly improve estimates of C cycling parameters. Samples collected between ca. 1965 and 1995 have now greatly surpassed pre-bomb samples in utility, although pre-bomb samples retain considerable usefulness for estimating the size of inert (millennial) C pools. Major pitfalls in the use of bomb 14C, particularly for single time point samples and fractions, are mainly associated with model assumptions. For example, calculated residence times can be highly sensitive to a minor component of old C (<10% of total C). Similarly, calculated residence times are also highly dependent upon rates of soil C accumulation or loss. A final key source of error is lag times between C fixation from atmospheric CO2 and incorporation in the measured soil C pool, either due to long-lived plant tissue, or residence

Epidemiology of malignant mesothelioma in Italy: surveillance systems, territorial clusters and occupations involved

PubMed Central

Binazzi, Alessandra; Bonafede, Michela; Di Marzio, Davide; Scarselli, Alberto

2018-01-01

Background As a legacy of the large asbestos consumption until the definitive ban in 1992, Italy is currently suffering a severe epidemic of asbestos related diseases. The aim of this paper is to describe the surveillance system for mesothelioma incidence and to provide evidences regarding the occurrence of the disease in Italy and the circumstances of asbestos exposure. Methods Italian National Register of Malignant Mesotheliomas (ReNaM) is a permanent surveillance system of mesothelioma incidence, with Regional Operating Centres (CORs) active in each Italian region, identifying incident malignant mesothelioma (MM) cases from health care structures. Occupational history, lifestyle habits and residential history are obtained using a standardised questionnaire, administered by a trained interviewer, to the subject or to the next of kin. Descriptive epidemiological figures, occupations involved in exposures and territorial maps of MM cases have been produced. Results At December 2016, ReNaM has collected 27,356 MM cases for the incidence period between 1993 and 2015. The modalities of exposure to asbestos have been investigated for 21,387 (78%) and an occupational exposure has been defined for around 70% of interviewed cases (14,818). Non-occupational exposure is still relevant with 4.9% and 4.4% of cases for which respectively a familial exposure (due to the cohabitation with an occupational exposed subject) and an environmental exposure (due to the residence near a contaminated site) has been detected. Discussion The epidemiological surveillance of MM incident cases, by the means of a national register for estimating the occurrence of the disease and identifying the circumstances of asbestos exposure, is a relevant tool for preventing asbestos exposure, for supporting the effectiveness of insurance system and for estimating reliable epidemiological figures. PMID:29507789

Abundance of (14)C in biomass fractions of wastes and solid recovered fuels.

PubMed

Fellner, Johann; Rechberger, Helmut

2009-05-01

In recent years thermal utilization of mixed wastes and solid recovered fuels has become of increasing importance in European waste management. Since wastes or solid recovered fuels are generally composed of fossil and biogenic materials, only part of the CO(2) emissions is accounted for in greenhouse gas inventories or emission trading schemes. A promising approach for determining this fraction is the so-called radiocarbon method. It is based on different ratios of the carbon isotopes (14)C and (12)C in fossil and biogenic fuels. Fossil fuels have zero radiocarbon, whereas biogenic materials are enriched in (14)C and reflect the (14)CO(2) abundance of the ambient atmosphere. Due to nuclear weapons tests in the past century, the radiocarbon content in the atmosphere has not been constant, which has resulted in a varying (14)C content of biogenic matter, depending on the period of growth. In the present paper (14)C contents of different biogenic waste fractions (e.g., kitchen waste, paper, wood), as well as mixtures of different wastes (household, bulky waste, and commercial waste), and solid recovered fuels are determined. The calculated (14)C content of the materials investigated ranges between 98 and 135pMC.

14. Photocopy of photograph (from William H. Knowles Collection, c. ...

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

14. Photocopy of photograph (from William H. Knowles Collection, c. 1880) EXTERIOR, SOUTH FRONT AND WEST SIDE OF MISSION, C. 1880 - Mission San Francisco Solano de Sonoma, First & Spain Streets, Sonoma, Sonoma County, CA

Comparison of Upward and Downward Translocation of 14C From a Single Leaf of Sunflower

PubMed Central

Shiroya, Michi

1968-01-01

When single leaves attached at a given node were allowed to carry on photosynthesis in 14CO2 for 30 min, younger plants showed a higher proportion of upward translocation than did older plants. Downward translocation of 14C-photosynthate was stimulated by ATP pre-treatment of the translocating leaf, while upward translocation was not affected by ATP. A similar phenomenon was observed in the translocation of 14C-sucrose infiltrated into a leaf with or without ATP. Downward translocation of photosynthate was inhibited by DNP pre-treatment of a fed leaf. Upward translocation, however, was not affected by DNP. Thirty min after infiltration of 14C-glucose into a leaf, almost all the 14C translocated upwards was found to be in the form of glucose, while a great part of the 14C translocated downwards was in the form of sucrose. In the case of translocation of infiltrated 14C-sucrose, 14C found both above and below the fed leaf was mainly in the form of sucrose. PMID:16656944

Comparison of C-14 liquid scintillation counting at NIST and NRC Canada

PubMed Central

Bergeron, Denis E.; Galea, Raphael; Laureano-Pérez, Lizbeth; Zimmerman, Brian E.

2016-01-01

An informal bilateral comparison of 14C liquid scintillation (LS) counting at the National Research Council of Canada (NRC) and the National Institute of Standards and Technology (NIST) has been completed. Two solutions, one containing 14C-labeled sodium benzoate and one containing 14C-labeled n-hexadecane, were measured at both laboratories. Despite observed LS cocktail instabilities, the two laboratories achieved accord in their standardizations of both solutions. At the conclusion of the comparison, the beta spectrum used for efficiency calculations was identified as inadequate and the data were reanalyzed with different inputs, improving accord. PMID:26585641

Comparison of (14)C liquid scintillation counting at NIST and NRC Canada.

PubMed

Bergeron, Denis E; Galea, Raphael; Laureano-Pérez, Lizbeth; Zimmerman, Brian E

2016-03-01

An informal bilateral comparison of (14)C liquid scintillation (LS) counting at the National Research Council of Canada (NRC) and the National Institute of Standards and Technology (NIST) has been completed. Two solutions, one containing (14)C-labeled sodium benzoate and one containing (14)C-labeled n-hexadecane, were measured at both laboratories. Despite observed LS cocktail instabilities, the two laboratories achieved accord in their standardizations of both solutions. At the conclusion of the comparison, the beta spectrum used for efficiency calculations was identified as inadequate and the data were reanalyzed with different inputs, improving accord. Published by Elsevier Ltd.

Bioavailability of the Nano-Unit 14C-Agrochemicals Under Various Water Potential.

PubMed

Jung, S C; Kim, H G; Kuk, Y I; Ahn, H G; Senseman, S A; Lee, D J

2015-08-01

The study was conducted to investigate the effects of water potential on bioavailability of the nano-unit 14C-cafenstrole, 14C-pretilachlor, 14C-benfuresate, 14C-simetryn and 14C-oxyfluorfen applied with or without dimepiperate or daimuron under various water potential conditions. The highest bioavailable concentration in soil solution (BCSS) was found at 60% soil moisture, while the lowest occurred at 50% soil moisture for soil-applied alone or in combination. All water potential conditions differed significantly from each other with variations in total bioavailable amount in soil solution (TBSS) when either dimepiperate or daimuron were added to the soil, and changes were directly proportional to variations in water potential. Across all treatments, TBSS at 80% soil moisture was three to four times greater than that at 50% soil moisture when applied alone or in combination with dimepiperate or daimuron. Cafenstrole and simetryn had distribution coefficient (Kd) values <64 ml g-1 and a TBSS ranging from 10 to 44 ng g-1 soil, regardless of water potential conditions applied alone or in combination. Pretilachlor and benfuresate had Kd values <15 ml g-1 and a TBSS range of 38 to 255 ng g-1 soil when applied with or without dimepiperate or daimuron.

Contaminants in human nail dust: an occupational hazard in podiatry?

PubMed Central

2014-01-01

Background There has been limited literature indicating that podiatrists’ health may be at risk from exposure to human nail dust. Previous studies carried out in the UK have shown that large amounts of dust become airborne during the human nail drilling procedure and are present in the air up to 10 hours after a clinical session. This increases the risk of Respiratory Tract (RT) infection for the practitioner. Methods This study used a nasal swabbing technique and fungal culture to determine whether podiatrists (n = 50) had the same microbes present in their nasal cavities as non-podiatry health professional control group (n = 45). All swabs were cultured, counted and identified for each subject. Survey data of use and type of nail drill, type of mask used and frequency of change over a two week period. Results The results showed podiatrists had a greater range of microbes in their nasal cavities although the controls had greater overall numbers of organisms. The known pathogen and common mould, Aspergillus fumigatus was ost commonly found fungus within the podiatric group with 44% of the group having the fungus present. All nail drills used by the podiatrists had some form of dust extraction (except one). Of concern was 17% (n = 8) of the podiatrists did not use a mask at all whilst drilling and seemed unaware of any infection control issues. Simple disposable masks were the most frequently worn with only half being changed after each patient further increasing the cross infection risk Conclusion The high levels of Aspergilus contamination is a significant finding in the podiatry group as this fungus is small enough to enter the tissue of the nasal cavity and as a small particle will stay airborne in the room for up to 16 hours. Aspergilus has been shown to cause brain and soft tissue tumours in extreme cases. The high levels of upper respiratory track problems reported in the literature may well be caused by this fungal agent. The non use and use of

Contaminants in human nail dust: an occupational hazard in podiatry?

PubMed

Tinley, Paul D; Eddy, Karen; Collier, Peter

2014-02-20

There has been limited literature indicating that podiatrists' health may be at risk from exposure to human nail dust. Previous studies carried out in the UK have shown that large amounts of dust become airborne during the human nail drilling procedure and are present in the air up to 10 hours after a clinical session. This increases the risk of Respiratory Tract (RT) infection for the practitioner. This study used a nasal swabbing technique and fungal culture to determine whether podiatrists (n = 50) had the same microbes present in their nasal cavities as non-podiatry health professional control group (n = 45). All swabs were cultured, counted and identified for each subject. Survey data of use and type of nail drill, type of mask used and frequency of change over a two week period. The results showed podiatrists had a greater range of microbes in their nasal cavities although the controls had greater overall numbers of organisms. The known pathogen and common mould, Aspergillus fumigatus was ost commonly found fungus within the podiatric group with 44% of the group having the fungus present. All nail drills used by the podiatrists had some form of dust extraction (except one). Of concern was 17% (n = 8) of the podiatrists did not use a mask at all whilst drilling and seemed unaware of any infection control issues. Simple disposable masks were the most frequently worn with only half being changed after each patient further increasing the cross infection risk The high levels of Aspergilus contamination is a significant finding in the podiatry group as this fungus is small enough to enter the tissue of the nasal cavity and as a small particle will stay airborne in the room for up to 16 hours. Aspergilus has been shown to cause brain and soft tissue tumours in extreme cases. The high levels of upper respiratory track problems reported in the literature may well be caused by this fungal agent. The non use and use of inappropriate masks by podiatrists is clearly an

Toxicity and oxidative stress induced by chromium in workers exposed from different occupational settings around the globe: A review.

PubMed

Junaid, Muhammad; Hashmi, Muhammad Zaffar; Malik, Riffat Naseem; Pei, De-Sheng

2016-10-01

The present review focused on the levels and toxicological status of heavy metals especially chromium (Cr) in the exposed workers from different occupational settings around the globe and in Pakistan. It was found that exposed workers from leather tanning and metal plating units showed elevated levels of Cr than the workers from other occupational settings. Cr and other heavy metals level in biological matrices of the exposed workers in different occupational settings revealed that developing countries are severely contaminated. Occupational settings from the Sialkot district, Pakistan exhibited elevated level of Cr in biological entities of the exposed workers. Review suggested that higher level of Cr exposure to the workers enhance the oxidative stress (reactive oxygen species (ROS) and hydroxyl (OH) radical generation) which may cause; cellular and molecular damage such as genotoxicity and chromosomal aberration formations, and carcinogenic effects. This review will help to understand the Cr contamination mechanisms and associated health implications in different occupational settings around the globe in general and particularly to Pakistan. This study will also assist occupational health and safety management authorities to devise or change the Cr recommended exposure limits (REL) for different occupational settings.

14 CFR Appendix C to Part 125 - Ice Protection

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Ice Protection C Appendix C to Part 125...—Ice Protection If certification with ice protection provisions is desired, compliance with the following must be shown: (a) The recommended procedures for the use of the ice protection equipment must be...

14 CFR Appendix C to Part 125 - Ice Protection

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Ice Protection C Appendix C to Part 125...—Ice Protection If certification with ice protection provisions is desired, compliance with the following must be shown: (a) The recommended procedures for the use of the ice protection equipment must be...

14 CFR Appendix C to Part 125 - Ice Protection

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Ice Protection C Appendix C to Part 125...—Ice Protection If certification with ice protection provisions is desired, compliance with the following must be shown: (a) The recommended procedures for the use of the ice protection equipment must be...

14 CFR Appendix C to Part 125 - Ice Protection

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Ice Protection C Appendix C to Part 125...—Ice Protection If certification with ice protection provisions is desired, compliance with the following must be shown: (a) The recommended procedures for the use of the ice protection equipment must be...

Comprehensive evaluation of long-term trends in occupational exposure: Part 1. Description of the database

PubMed Central

Symanski, E.; Kupper, L. L.; Rappaport, S. M.

1998-01-01

OBJECTIVES: To conduct a comprehensive evaluation of long term changes in occupational exposure among a broad cross section of industries worldwide. METHODS: A review of the scientific literature identified studies that reported historical changes in exposure. About 700 sets of data from 119 published and several unpublished sources were compiled. Data were published over a 30 year period in 25 journals that spanned a range of disciplines. For each data set, the average exposure level was compiled for each period and details on the contaminant, the industry and location, changes in the threshold limit value (TLV), as well as the type of sampling method were recorded. Spearman rank correlation coefficients were used to identify monotonic changes in exposure over time and simple linear regression analyses were used to characterise trends in exposure. RESULTS: About 78% of the natural log transformed data showed linear trends towards lower exposure levels whereas 22% indicated increasing trends. (The Spearman rank correlation analyses produced a similar breakdown between exposures monotonically increasing or decreasing over time.) Although the rates of reduction for the data showing downward trends ranged from -1% to -62% per year, most exposures declined at rates between -4% and -14% per year (the interquartile range), with a median value of -8% per year. Exposures seemed to increase at rates that were slightly lower than those of exposures which have declined over time. Data sets that showed downward (versus upward) trends were influenced by several factors including type and carcinogenicity of the contaminant, type of monitoring, historical changes in the threshold limit values (TLVs), and period of sampling. CONCLUSIONS: This review supports the notion that occupational exposures are generally lower today than they were years or decades ago. However, such trends seem to have been affected by factors related to the contaminant, as well as to the period and type of

Microbial Degradation of Phenanthrene in Pristine and Contaminated Sandy Soils.

PubMed

Schwarz, Alexandra; Adetutu, Eric M; Juhasz, Albert L; Aburto-Medina, Arturo; Ball, Andrew S; Shahsavari, Esmaeil

2018-05-01

Phenanthrene mineralisation studies in both pristine and contaminated sandy soils were undertaken through detailed assessment of the activity and diversity of the microbial community. Stable isotope probing (SIP) was used to assess and identify active 13 C-labelled phenanthrene degraders. Baseline profiling indicated that there was little difference in fungal diversity but a significant difference in bacterial diversity dependent on contamination history. Identification of dominant fungal and bacterial species highlighted the presence of organisms capable of degrading various petroleum-based compounds together with other anthropogenic compounds, regardless of contamination history. Community response following a simulated contamination event ( 14 C-phenanthrene) showed that the microbial community in deep pristine and shallow contaminated soils adapted most to the presence of phenanthrene. The similarity in microbial community structure of well-adapted soils demonstrated that a highly adaptable fungal community in these soils enabled a rapid response to the introduction of a contaminant. Ten fungal and 15 bacterial species were identified as active degraders of phenanthrene. The fungal degraders were dominated by the phylum Basidiomycota including the genus Crypotococcus, Cladosporium and Tremellales. Bacterial degraders included the genera Alcanivorax, Marinobacter and Enterococcus. There was little synergy between dominant baseline microbes, predicted degraders and those that were determined to be actually degrading the contaminant. Overall, assessment of baseline microbial community in contaminated soils provides useful information; however, additional laboratory assessment of the microbial community's ability to degrade pollutants allows for better prediction of the bioremediation potential of a soil.

Evidence of polycyclic aromatic hydrocarbon biodegradation in a contaminated aquifer by combined application of in situ and laboratory microcosms using (13)C-labelled target compounds.

PubMed

Bahr, Arne; Fischer, Anko; Vogt, Carsten; Bombach, Petra

2015-02-01

The number of approaches to evaluate the biodegradation of polycyclic aromatic hydrocarbons (PAHs) within contaminated aquifers is limited. Here, we demonstrate the applicability of a novel method based on the combination of in situ and laboratory microcosms using (13)C-labelled PAHs as tracer compounds. The biodegradation of four PAHs (naphthalene, fluorene, phenanthrene, and acenaphthene) was investigated in an oxic aquifer at the site of a former gas plant. In situ biodegradation of naphthalene and fluorene was demonstrated using in situ microcosms (BACTRAP(®)s). BACTRAP(®)s amended with either [(13)C6]-naphthalene or [(13)C5/(13)C6]-fluorene (50:50) were incubated for a period of over two months in two groundwater wells located at the contaminant source and plume fringe, respectively. Amino acids extracted from BACTRAP(®)-grown cells showed significant (13)C-enrichments with (13)C-fractions of up to 30.4% for naphthalene and 3.8% for fluorene, thus providing evidence for the in situ biodegradation and assimilation of those PAHs at the field site. To quantify the mineralisation of PAHs, laboratory microcosms were set up with BACTRAP(®)-grown cells and groundwater. Naphthalene, fluorene, phenanthrene, or acenaphthene were added as (13)C-labelled substrates. (13)C-enrichment of the produced CO2 revealed mineralisation of between 5.9% and 19.7% for fluorene, between 11.1% and 35.1% for acenaphthene, between 14.2% and 33.1% for phenanthrene, and up to 37.0% for naphthalene over a period of 62 days. Observed PAH mineralisation rates ranged between 17 μg L(-1) d(-1) and 1639 μg L(-1) d(-1). The novel approach combining in situ and laboratory microcosms allowed a comprehensive evaluation of PAH biodegradation at the investigated field site, revealing the method's potential for the assessment of PAH degradation within contaminated aquifers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biodegradation Kinetics of 1,4-Dioxane in Chlorinated Solvent Mixtures.

PubMed

Zhang, Shu; Gedalanga, Phillip B; Mahendra, Shaily

2016-09-06

This study investigated the impacts of individual chlorinated solvents and their mixtures on aerobic 1,4-dioxane biodegradation by Pseudonocardia dioxanivorans CB1190. The established association of these co-occurring compounds suggests important considerations for their respective biodegradation processes. Our kinetics and mechanistic studies demonstrated that individual solvents inhibited biodegradation of 1,4-dioxane in the following order: 1,1-dichloroethene (1,1-DCE) > cis-1,2-diochloroethene (cDCE) > trichloroethene (TCE) > 1,1,1-trichloroethane (TCA). The presence of 5 mg L(-1) 1,1-DCE completely inhibited 1,4-dioxane biodegradation. Subsequently, we determined that 1,1-DCE was the strongest inhibitor of 1,4-dioxane biodegradation by bacterial pure cultures exposed to chlorinated solvent mixtures as well as in environmental samples collected from a site contaminated with chlorinated solvents and 1,4-dioxane. Inhibition of 1,4-dioxane biodegradation rates by chlorinated solvents was attributed to delayed ATP production and down-regulation of both 1,4-dioxane monooxygenase (dxmB) and aldehyde dehydrogenase (aldH) genes. Moreover, increasing concentrations of 1,1-DCE and cis-1,2-DCE to 50 mg L(-1) respectively increased 5.0-fold and 3.5-fold the expression of the uspA gene encoding a universal stress protein. In situ natural attenuation or enhanced biodegradation of 1,4-dioxane is being considered for contaminated groundwater and industrial wastewater, so these results will have implications for selecting 1,4-dioxane bioremediation strategies at sites where chlorinated solvents are present as co-contaminants.

29 CFR 1912a.14 - Petitions for changes in the rules; complaints.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Section 1912a.14 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) NATIONAL ADVISORY COMMITTEE ON OCCUPATIONAL SAFETY AND HEALTH... § 1912a.14 and be filed and addressed as follows: Assistant Secretary of Labor for Occupational Safety and...

29 CFR 1912a.14 - Petitions for changes in the rules; complaints.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 1912a.14 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) NATIONAL ADVISORY COMMITTEE ON OCCUPATIONAL SAFETY AND HEALTH... § 1912a.14 and be filed and addressed as follows: Assistant Secretary of Labor for Occupational Safety and...

Environmental projects. Volume 14: Removal of contaminated soil and debris

NASA Technical Reports Server (NTRS)

Kushner, Len

1992-01-01

Numerous diverse activities at the Goldstone Deep Space Communications Complex (GDSCC) are carried out in support of six parabolic dish antennas. Some of these activities can result in possible spills or leakages of hazardous materials and wastes stored both above ground in steel drums and below ground in underground storage tanks (UST's). These possible leaks or spills, along with the past practice of burial of solid debris and waste in trenches and pits, could cause local subsurface contamination of the soil. In 1987, the Jet Propulsion Laboratory (JPL), retained Engineering-Science, Inc. (E-S), Pasadena, California, to identify the specific local areas within the GDSCC with subsurface soil contamination. The E-S study determined that some of the soils at the Apollo Site and the Mars Site were contaminated with hydrocarbons, while soil at a nonhazardous waste dumpsite at the Mojave Base site was contaminated with copper. This volume is a JPL-expanded version of the PE209 E-S report, and it also reports that all subsurface contaminated soils at the GDSCC were excavated, removed, and disposed of in an environmentally acceptable way, and the excavations were backfilled and covered in accordance with accepted Federal, State, and local environmental rules and regulations.

DISTRIBUTION OF 14C-ATRAZINE FOLLOWING AN ACUTE LACTATIONAL EXPOSURE IN THE WISTAR RAT.

EPA Science Inventory

The purpose of the present study was to examine the distribution of atrazine in the lactating dam and suckling neonate following an acute exposure to either 2 or 4 mg/kg 14C-atrazine (14C-ATR) by gavage. 14C-ATR was administered to the nursing dam on postnatal day 3 by oral gavag...

Utilization of [14C]phenylalanine derived from arylphorin or free amino acid in Manduca sexta pharate adults

NASA Technical Reports Server (NTRS)

Wu, M.; Tischler, M. E.

1995-01-01

The role of arylphorin as a storage protein was studied using 14C-arylphorin. 14C-arylphorin was produced optimally by incubating one-half fat body from Manduca sexta fifth instar larvae at 22 degrees C for 24 h, in 1 ml of medium containing amino acids at 25% of their physiological concentration with [U-14C]-phenylalanine (phe) provided initially without nonlabeled phenylalanine. Nonlabeled phe was provided after 1 h at 16% of its physiological concentration. The specific activity of 14C-arylphorin produced in vitro was 30 times greater than that generated in vivo. Injection of 14C-arylphorin into pharate adults was used to study the distribution of 14C-phe derived from this protein into 14CO2 and tissues for comparison with injection of free 14C-phe during the middle (days 6 to 12 pharate adult) and late (days 12 to 17 pharate adult) stages of adult development. Appearance of 14CO2 from 14C-arylphorin as compared to 14C-phenylalanine showed a slower time course during both the middle and late stages of development, in keeping with the time needed for degradation of the protein. In accord with faster phe turnover near the end of adult development, total 14CO2 production was greater and the retention of 14C in hemolymph and fat body was less compared to the middle stage of development regardless of whether 14C-arylphorin or 14C-phe was injected. In the middle stage of development, the appearance of 14C in the cuticle and head parts was greater, whereas incorporation into abdomen and thorax was less than during the late stage of development. Since the pattern of 14C distribution from 14C-arylphorin and 14C-phe was similar, one major function of arylphorin must be as a storage protein replenishing the supply of free amino acids used for synthesis of adult tissues. These results also suggest a limited contribution of M. sexta arylphorin to formation of the cuticle subsequent to day-6 pharate adult.

Improving 14C dating precision in dynamic, brackish waters by one order of magnitude: 87Sr/86Sr isotopes as a quantitative proxy for 14C reservoir age.

NASA Astrophysics Data System (ADS)

Lougheed, B.; Davies, G.; Filipsson, H. L.; van der Lubbe, J.; Snowball, I.

2016-12-01

Accurate geochronologies are crucial for reconstructing the sensitivity of brackish and estuarine environments to external impacts. A common geochronological method used for such studies is radiocarbon (14C) dating, but its application in brackish environments is severely limited by an inability to quantify spatiotemporal variations in 14C reservoir age, or R(t), due to dynamic interplay between river runoff and marine water in these environments. Additionally, old carbon effects and species-specific behavioural processes also influence 14C ages. Using the world's largest brackish water body (the estuarine Baltic Sea) as a test-bed, combined with a comprehensive approach that objectively excludes both old carbon and species-specific effects, we demonstrate that it is possible to use 87Sr/86Sr ratios to quantify R(t) in ubiquitous mollusc shell material, leading to an almost one order of magnitude increase in Baltic Sea 14C geochronological precision over the current state-of-the-art. We propose that this novel proxy method can be developed for other brackish water bodies worldwide, thereby improving geochronological control in these climate sensitive, near-coastal environments.

Measurement of /sup 14/C emission rates from a pressurized heavy water reactor

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

Joshi, M.L.; Ramamirtham, B.; Soman, S.D.

Carbon-14 is produced in pressurized heavy water reactors (PHWR), mainly as an activation product in the fuel. It is also produced in the heavy water used as the primary coolant and moderator, and is produced in the air in the annular space between the pressure tube and calandria tubes as well as in the free space in the calandria vault. The production rates in different systems of a PHWR are calculated on the basis of design parameters. During a period of 3 y, /sup 14/C released through the gaseous route has been measured at Rajasthan Atomic Power Station, Kota, India,more » a PHWR unit. These releases have been found to be mainly /sup 14/CO/sub 2/. This reduced form of /sup 14/C is less than 5% of the releases. The normalized releases of /sup 14/C have a geometric mean of 5.17 TBq GWe-1 y-1 and a geometric standard deviation of 1.52. The /sup 14/C present in the form of carbonates in liquid effluents has also been measured and is 0.14% of the gaseous releases.« less

Removal of Legacy Low-Level Waste Reactor Moderator De-ionizer Resins Highly Contaminated with Carbon-14 from the 'Waste with no Path to Disposal List' Through Innovative Technical Analysis and Performance Assessment Techniques

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

Goldston, W.T.; Hiergesell, R.A.; Kaplan, D.I.

2006-07-01

At the Savannah River Site (SRS), nuclear production reactors used de-ionizers to control the chemistry of the reactor moderator during their operation to produce nuclear materials primarily for the weapons program. These de-ionizers were removed from the reactors and stored as a legacy waste and due to the relatively high carbon-14 (C-14) contamination (i.e., on the order of 740 giga becquerel (GBq) (20 curies) per de-ionizer) were considered a legacy 'waste with no path to disposal'. Considerable progress has been made in consideration of a disposal path for the legacy reactor de-ionizers. Presently, 48 - 50 de-ionizers being stored atmore » SRS have 'no path to disposal' because the disposal limit for C-14 in the SRS's low-level waste disposal facility's Intermediate Level Vault (ILV) is only 160 GBq (4.2 curies) per vault. The current C-14 ILV disposal limit is based on a very conservative analysis of the air pathway. The paper will describe the alternatives that were investigated that resulted in the selection of a route to pursue. This paper will then describe SRS's efforts to reduce the conservatism in the analysis, which resulted in a significantly larger C-14 disposal limit. The work consisted of refining the gas-phase analysis to simulate the migration of C-14 from the waste to the ground surface and evaluated the efficacy of carbonate chemistry in cementitious environment of the ILV for suppressing the volatilization of C-14. During the past year, a Special Analysis was prepared for Department of Energy approval to incorporate the results of these activities that increased the C-14 disposal limits for the ILV, thus allowing for disposal of the Reactor Moderator De-ionizers. Once the Special Analysis is approved by DOE, the actual disposal would be dependent on priority and funding, but the de-ionizers will be removed from the 'waste with no path to disposal list'. (authors)« less

National guidelines on management of occupational exposure to HIV.

PubMed

Rewari, B B; Negi, Shivi

2009-05-01

During patient care, the healthcare personnel are at risk of infection of blood-borne pathogens (HIV, HBV, HCV) which is referred to as occupational exposure. Exposure to blood, semen, vaginal secretions, CSF, synovial, pleural, peritoneal, pericardial fluid, amniotic fluid and other body fluids contaminated with visible blood can lead to infection. Steps which are to be followed after occupational exposure are: (1) Step I : First aid following the exposure. (2) Step 2: Establish eligibility for postexposure prophylaxis (PEP). (3) Step 3: Counselling for PEP. (4) Step 4: Prescribe PEP. (5) HIV chemoprophylaxis. (6) Step 6: Follow-up of an exposed person. In order to get timely prophylactic therapy, PEP drugs should be kept available round-the-clock in at least three locations, casualty, ICU and labour room. Every hospital should have a written protocol and SOP for handling occupational exposure. NACO is in the process of launching a national HIV PEP Registry for capturing the cases of occupational exposure to HIV more effectively.

Quantitative assessment of bio-aerosols contamination in indoor air of University dormitory rooms.

PubMed

Hayleeyesus, Samuel Fekadu; Ejeso, Amanuel; Derseh, Fikirte Aklilu

2015-07-01

The purpose of this study is to provide insight into how students are exposed to indoor bio-aerosols in the dormitory rooms and to figure out the major possible factors that govern the contamination levels. The Bio-aerosols concentration level of indoor air of thirty dormitory rooms of Jimma University was determined by taking 120 samples. Passive air sampling technique; the settle plate method using open Petri-dishes containing different culture media was employed to collect sample twice daily. The range of bio-aerosols contamination detected in the dormitory rooms was 511-9960 CFU/m(3) for bacterial and 531-6568 CFU/m(3) for fungi. Based on the criteria stated by WHO expert group, from the total 120 samples 95 of the samples were above the recommended level. The statistical analysis showed that, occupancy were significantly affected the concentrations of bacteria that were measured in all dormitory rooms at 6:00 am sampling time (p-value=0.000) and also the concentrations of bacteria that were measured in all dormitory rooms were significantly different to each other (p-value=0.013) as of their significance difference in occupancy (p-value=0.000). Moreover, there were a significant different on the contamination level of bacteria at 6:00 am and 7:00 pm sampling time (p=0.015), whereas there is no significant difference for fungi contamination level for two sampling times (p= 0.674). There is excessive bio-aerosols contaminant in indoor air of dormitory rooms of Jimma University and human occupancy produces a marked concentration increase of bacterial contamination levels and most fungi species present into the rooms air of Jimma University dormitory were not human-borne.

14 CFR Appendix C to Part 23 - Basic Landing Conditions

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Basic Landing Conditions C Appendix C to... to Part 23—Basic Landing Conditions [C23.1 Basic landing conditions] Condition Tail wheel type Level landing Tail-down landing Nose wheel type Level landing with inclined reactions Level landing with nose...

Healthcare Worker Occupation and Immune Response to Pneumocystis jirovecii

PubMed Central

Daly, Kieran R.; Jarlsberg, Leah G.; Koch, Judy V.; Swartzman, Alexandra; Roth, Brenna M.; Walzer, Peter D.; Huang, Laurence

2009-01-01

The reservoir and mode of transmission of Pneumocystis jirovecii remain uncertain. We conducted a cross-sectional study of 126 San Francisco General Hospital staff in clinical (n = 103) and nonclinical (n = 23) occupations to assess whether occupational exposure was associated with immune responses to P. jirovecii. We examined antibody levels by ELISA for 3 overlapping fragments that span the P. jirovecii major surface glycoprotein (Msg): MsgA, MsgB, and MsgC1. Clinical occupation participants had higher geometric mean antibody levels to MsgC1 than did nonclinical occupation participants (21.1 vs. 8.2, p = 0.004); clinical occupation was an independent predictor of higher MsgC1 antibody levels (parameter estimate = 0.89, 95% confidence interval 0.29–1.48, p = 0.003). In contrast, occupation was not significantly associated with antibody responses to either MsgA or MsgB. Healthcare workers may have occupational exposure to P. jirovecii. Humans may be a reservoir for P. jirovecii and may transmit it from person to person. PMID:19861050

A simple method to determine mineralization of (14) C-labeled compounds in soil.

PubMed

Myung, Kyung; Madary, Michael W; Satchivi, Norbert M

2014-06-01

Degradation of organic compounds in soil is often determined by measuring the decrease of the parent compound and analyzing the occurrence of its metabolites. However, determining carbon species as end products of parent compound dissipation requires using labeled materials that allow more accurate determination of the environmental fate of the compound of interest. The current conventional closed system widely used to monitor degradation of (14) C-labeled compounds in soil is complex and expensive and requires a specialized apparatus and facility. In the present study, the authors describe a simple system that facilitates measurement of mineralization of (14) C-labeled compounds applied to soil samples. In the system, soda lime pellets to trap mineralized (14) C-carbon species, including carbon dioxide, were placed in a cup, which was then inserted above the treated soil sample in a tube. Mineralization of [(14) C]2,4-D applied to soil samples in the simple system was compared with that in the conventional system. The simple system provided an equivalent detection of (14) C-carbon species mineralized from the parent compound. The results demonstrate that this cost- and space-effective simple system is suitable for examining degradation and mineralization of (14) C-labeled compounds in soil and could potentially be used to investigate their mineralization in other biological matrices. © 2014 SETAC.

Introducing disability studies to occupational therapy students.

PubMed

Block, Pamela; Ricafrente-Biazon, Melissa; Russo, Ann; Chu, Ke Yun; Sud, Suman; Koerner, Lori; Vittoria, Karen; Landgrover, Alyssa; Olowu, Tosin

2005-01-01

This article is a work of collaborative ethnography about teaching and learning disability studies within the context of an occupational therapy graduate program. In spring 2004,14 occupational therapy students were introduced to disability studies by their cultural anthropologist (nonoccupational therapist) course instructor. During the one-credit course, they were expected to complete readings, watch films, attend guest lectures, and make a site visit. The occupational therapy students were required to write a journal to record personal reactions and new insights gained from these experiences. This article focuses on a thematic analysis of the students' journaled responses to the film "Dance Me to My Song," and a site visit to a local Independent Living Center. Students were expected to analyze these experiences from both disability studies and occupational therapy perspectives. The article addresses philosophical and practical differences between occupational therapy and disability studies and identifies opportunities for collaboration between occupational therapists and independent living specialists.

[The occupational physicians' responsibilities].

PubMed

Guardavilla, A

2010-01-01

Occupational physicians can commit two kind of crimes: they can violate rules of safety and health at work with no immediate consequences for the employees but anyway creating a potential danger for them, or they can cause, because of their blame, occupational diseases or accidents at work to the employees. In both cases they can be punished. If we want to understand in detail this kind of responsibility, we must read the Supreme Court's judgements (Supreme Court, 19099/2009; 26539/2008; 20220/2006; 17838/2005; 26439/2007; 24290/2005). The numberless innovations introduced in recent years in the body of occupational safety and health laws called for a different reading of the meaning and the content of occupational physicians' functions, requiring them to collaborate, more than in the past, in the assessment of workplace risks. The responsibility of occupational physicians should be seen also in relation to the responsibility of employers and managers (see the link between health surveillance and art. 18 paragraph 1 letter c) of Legislative Decree no. 81/08). In the occupational safety and health context, the employer and his managers must also require (and ensure) occupational physicians to fulfill their obligations and professional duties.

Occupational skin hazards and prevalence of occupational skin diseases in shoe manufacturing workers in Indonesia.

PubMed

Febriana, Sri Awalia; Soebono, Hardyanto; Coenraads, Pieter-Jan

2014-02-01

Shoe manufacturing workers are exposed daily to an extensive range of potential physical and chemical occupational hazards. Shoe manufacturing in Indonesia is one of the industrial sectors that has shown sustained growth amongst the newly industrialized countries (NICs). In this study, we investigated the possible potential exposure of the workers to physical and occupational hazards and determined the prevalence of occupational skin diseases at a shoe manufacturing factory in Indonesia. A cross-sectional study on the observation of the working process and an inventory and risk assessment of exposure to the chemicals used. Classification of chemicals as potential sensitizers/irritants and qualitative assessments of these chemicals were done. Workers were examined and interviewed using the Nordic Occupational Skin Questionnaire-2002/LONG. The risk of Occupational skin diseases (OSD) at the shoe factory was mainly related to the exposure of the workers' skin to potential physical and chemical hazards in hot and humid environmental conditions. From a total of 514 workers, 8.5 % reported current OSD and 4.8 % reported a history of OSD. Occupational skin diseases were diagnosed in 29 % of the workers by dermatologists and 7.6 % had an occupational contact dermatitis (OCD). Of the 39 workers with contact dermatitis, 33 consented to being patch tested, 14 (3 %) workers showed a positive results and considered as having an occupational allergic contact dermatitis (OACD) and 25 (4.9 %) had an occupational irritant contact dermatitis (OICD). We observed a repeated and prolonged exposure of the workers to numerous physical and chemical skin hazards at this factory.

Insights from 14C into C loss pathways in degraded peatlands

NASA Astrophysics Data System (ADS)

Evans, Martin; Evans, Chris; Allott, Tim; Stimson, Andrew; Goulsbra, Claire

2016-04-01

Peatlands are important global stores of terrestrial carbon. Lowered water tables due to changing climate and direct or indirect human intervention produce a deeper aerobic zone and have the potential to enhance loss of stored carbon from the peat profile. The quasi continuous accumulation of organic matter in active peatlands means that the age of fluvial dissolved organic carbon exported from peatland systems is related to the source depth in the peat profile. Consequently 14C analysis of DOC in waters draining peatlands has the potential not only to tell us about the source of fluvial carbon and the stability of the peatland but also about the dominant hydrological pathways in the peatland system. This paper will present new radiocarbon determinations from peatland streams draining the heavily eroded peatlands of the southern Pennine uplands in the UK. These blanket peatland systems are highly degraded, with extensive bare peat and gully erosion resulting from air pollution during the industrial revolution, overgrazing, wildfire and climatic changes. Deep and extensive gullying has significantly modified the hydrology of these systems leading to local and more widespread drawdown of water table. 14C data from DOC in drainage waters are presented from two catchments; one with extensive gully erosion and the other with a combination of gully erosion and sheet erosion of the peat. At the gully eroded site DOC in drainage waters is as old as 160 BP but at the site with extensive sheet erosion dates of up to 1069 BP are amongst the oldest recorded from blanket peatland globally These data indicate significant degradation of stored carbon from the eroding peatlands. Initial comparisons of the 14C data with modelled water table for the catchments and depth-age curves for catchment peats suggests that erosion of the peat surface, allowing decomposition of exposed older organic material is a potential mechanism producing aged carbon from the eroded catchment. This

[Occupational asthma in Hungary].

PubMed

Endre, László

2015-05-10

Occupational asthma belongs to communicable diseases, which should be reported in Hungary. During a 24-year period between January 1990 and December 2013, 180 occupational asthma cases were reported in Hungary (52 cases between 1990 and 1995, 83 cases between 1996 and 2000, 40 cases between 2001 and 2006, and 5 cases between 2007 and 2013). These data are unusual, because according to the official report of the National Korányi Pulmonology Institute in Budapest, at least 14,000 new adult asthma cases were reported in every year between 2000 and 2012 in Hungary. Also, international data indicate that at least 2% of adult patients with asthma have occupational asthma and at least 50 out of 1 million employees develop occupational asthma in each year. In 2003, 631 new occupational asthma patients were reported in the United Kingdom, but only 7 cases in Hungary. Because it is unlikely that the occupational environment in Hungary is much better than anywhere else in the world, it seems that not all new occupational asthma cases are reported in Hungary. Of the 180 reported cases in Hungary, 55 were bakers or other workers in flour mills. There were 11 metal-workers, 10 health care assistants, 9 workers dealing with textiles (tailors, dressmakers, workers in textile industry) and 9 employees worked upon leather and animal fur. According to international data, the most unsafe profession is the animal keeper in scientific laboratories, but only 4 of them were reported as having occupational asthma during the studied 24 years in Hungary. Interestingly, 3 museologists with newly-diagnosed occupational asthma were reported in 2003, but not such cases occurred before or after that year. In this paper the Hungarian literature of occupational asthma is summarized, followed by a review on the classification, pathomechanism, clinical presentation, predisposing factors, diagnostics and therapeutic aspects of the disease. Epidemiological data of adult asthma in Hungary and data from

14 CFR Appendix C to Part 135 - Helicopter Flight Recorder Specifications

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Helicopter Flight Recorder Specifications C Appendix C to Part 135 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION.... C Appendix C to Part 135—Helicopter Flight Recorder Specifications Parameters Range Installed system...

Higher Storage Temperature Causes Greater Salmonella enterica Serovar Typhimurium Internal Penetration of Artificially Contaminated, Commercially Available, Washed Free Range Eggs.

PubMed

Whiley, Alice; Fallowfield, Howard; Ross, Kirstin; McEvoy, Vanessa; Whiley, Harriet

2016-07-01

Foodborne salmonellosis is a major public health concern, with contaminated eggs identified as a significant source of infection. In Australia, the most prevalent cause of salmonellosis from eggs is Salmonella enterica subsp. enterica serovar Typhimurium. This study explored the effect of temperature after 1, 7, 14, 21, and 28 days of storage on commercially available washed free range eggs, artificially contaminated with Salmonella Typhimurium on the external surface. At each time point, the external surface of the egg, the crushed eggshell, and the internal egg yolk and albumen were analyzed for Salmonella. After 28 days of storage, 25% of eggs stored at 4°C, 50% of eggs stored at 14°C, and 100% of eggs stored at 23 and 35°C were internally contaminated with Salmonella. After 1 day of storage, more than 50% of all eggs had Salmonella present in the crushed shell after the external surface had been disinfected with ethanol. This is the first study to demonstrate that refrigeration reduced the potential for Salmonella Typhimurium to penetrate the eggshell membrane and internally contaminate table eggs commercially available in Australia. It also suggests that the processes of cracking eggs may be a source of cross-contamination within the kitchen.

42 CFR 86.14 - Evaluation and grant award.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES GRANTS FOR EDUCATION PROGRAMS IN OCCUPATIONAL SAFETY AND HEALTH Occupational Safety and Health Training Grants § 86.14 Evaluation and grant award. Within the limits of funds...

Toxic effects of 1,4-dichlorobenzene on photosynthesis in Chlorella pyrenoidosa.

PubMed

Zhang, Jinhua; Wang, Jie; Feng, Jia; Lv, Junping; Cai, Jin; Liu, Qi; Xie, Shulian

2016-09-01

1,4-Dichlorobenzene (1,4-DCB) is a common organic contaminant in water. To determine the effects of this contaminant on photosynthesis in the freshwater alga Chlorella pyrenoidosa, algal cells were treated with 1,4-DCB at different concentrations for various times, and their photosynthetic pigment contents and chlorophyll fluorescence traits were analyzed. The results showed that 1,4-DCB exerted toxic effects on photosynthesis in C. pyrenoidosa, especially at concentrations exceeding 10 mg/L. The inhibitory effects of 1,4-DCB were time- and concentration-dependent. After treatment with 1,4-DCB (≥10 mg/L), the contents of photosynthetic pigments decreased significantly, the photosystem II reaction center was irreversibly damaged, and the quantum yield of photosystem II decreased significantly. Also, there were sharp decreases in the efficiency of photosynthetic electron transport and energy conversion. Photosystem II became overloaded as the amount of excitation energy distributed to it increased. All of these events weakened the photochemical reaction, and ultimately led to serious inhibition of photosynthesis.

Empirical Evidence on Occupation and Industry Specific Human Capital

PubMed Central

Sullivan, Paul

2009-01-01

This paper presents instrumental variables estimates of the effects of firm tenure, occupation specific work experience, industry specific work experience, and general work experience on wages using data from the 1979 Cohort of the National Longitudinal Survey of Youth. The estimates indicate that both occupation and industry specific human capital are key determinants of wages, and the importance of various types of human capital varies widely across one-digit occupations. Human capital is primarily occupation specific in occupations such as craftsmen, where workers realize a 14% increase in wages after five years of occupation specific experience but do not realize wage gains from industry specific experience. In contrast, human capital is primarily industry specific in other occupations such as managerial employment where workers realize a 23% wage increase after five years of industry specific work experience. In other occupations, such as professional employment, both occupation and industry specific human capital are key determinants of wages. PMID:20526448

Chlorophyll a-specific Δ14C, δ13C and δ15N values in stream periphyton: implications for aquatic food web studies

NASA Astrophysics Data System (ADS)

Ishikawa, N. F.; Yamane, M.; Suga, H.; Ogawa, N. O.; Yokoyama, Y.; Ohkouchi, N.

2015-11-01

Periphytic algae attached to a streambed substrate (periphyton) are an important primary producer in stream ecosystems. We determined the isotopic composition of chlorophyll a in periphyton collected from a stream flowing on limestone bedrock in the Seri River, central Japan. Stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) and natural radiocarbon abundances (Δ14C) were measured in chlorophyll a (δ13Cchl, δ15Nchl and Δ14Cchl) and bulk (δ13Cbulk, δ15Nbulk and Δ14Cbulk) for periphyton, a pure aquatic primary producer (Cladophora sp.) and a terrestrial primary producer (Quercus glauca). Periphyton δ13Cbulk and δ13Cchl values did not necessarily correspond to δ13Cbulk for an algal-grazing specialist (Epeorus latifolium). Periphyton Δ14Cchl values (-258 ‰ in April and -190 ‰ in October) were slightly lower than Δ14Cbulk values (-228 ‰ in April and -179 ‰ in October) but were close to the Δ14C value for dissolved inorganic carbon (DIC; -217 ± 31 ‰), which is a mixture of weathered carbonates (Δ14C = -1000 ‰), CO2 derived from aquatic and terrestrial organic matters (variable Δ14C) and dissolved atmospheric CO2 (Δ14C approximately +30 ‰ in 2013). Δ14Cchl values were also close to Δ14Cbulk for E. latifolium (-215 ‰ in April and -199 ‰ in October) and Cladophora sp. (-210 ‰), whereas the Δ14Cbulk value for Q. glauca (+27 ‰) was closer to Δ14C for atmospheric CO2. Although the bulk isotopic composition of periphyton is recognised as a surrogate for the photosynthetic algal community, natural periphyton is a mixture of aquatic and terrestrial organic materials. Our results indicate that the bulk periphyton matrix at the study site consists of 89 to 95 % algal carbon (derived from 14C-depleted DIC) and 5 to 11 % terrestrial organic carbon (derived from 14C-enriched atmospheric CO2).

Probabilistic risk analysis of building contamination.

PubMed

Bolster, D T; Tartakovsky, D M

2008-10-01

We present a general framework for probabilistic risk assessment (PRA) of building contamination. PRA provides a powerful tool for the rigorous quantification of risk in contamination of building spaces. A typical PRA starts by identifying relevant components of a system (e.g. ventilation system components, potential sources of contaminants, remediation methods) and proceeds by using available information and statistical inference to estimate the probabilities of their failure. These probabilities are then combined by means of fault-tree analyses to yield probabilistic estimates of the risk of system failure (e.g. building contamination). A sensitivity study of PRAs can identify features and potential problems that need to be addressed with the most urgency. Often PRAs are amenable to approximations, which can significantly simplify the approach. All these features of PRA are presented in this paper via a simple illustrative example, which can be built upon in further studies. The tool presented here can be used to design and maintain adequate ventilation systems to minimize exposure of occupants to contaminants.

14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

Code of Federal Regulations, 2011 CFR

2011-01-01

... FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users Who... flight one year or less, but more than six months before launch, the user shall reimburse NASA an... shared flight six months or less before launch, the user shall reimburse NASA an occupancy fee of 90% of...

14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

Code of Federal Regulations, 2013 CFR

2013-01-01

... FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users Who... flight one year or less, but more than six months before launch, the user shall reimburse NASA an... shared flight six months or less before launch, the user shall reimburse NASA an occupancy fee of 90% of...

14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

Code of Federal Regulations, 2014 CFR

2014-01-01

... FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users Who... flight one year or less, but more than six months before launch, the user shall reimburse NASA an... shared flight six months or less before launch, the user shall reimburse NASA an occupancy fee of 90% of...

14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

Code of Federal Regulations, 2012 CFR

2012-01-01

... FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users Who... flight one year or less, but more than six months before launch, the user shall reimburse NASA an... shared flight six months or less before launch, the user shall reimburse NASA an occupancy fee of 90% of...

Supermassive Black Holes in Late-type Spiral Galaxies: Constraining High Mass X-ray Binary Contamination

NASA Astrophysics Data System (ADS)

Dittenber, Benjamin; Hodges-Kluck, Edmund J.; Gallo, Elena

2018-06-01

Supermassive black holes (SMBHs) are known to commonly reside in the centers of large galaxies, but it is unclear whether they reside in smaller galaxies (M_* < M_sun x 10^10). X-rays are the most efficient way to detect low-level accretion, and provide the best measurement of the occupation fraction. X-ray binaries can be nearly as bright as SMBHs that have sub-Eddington accretion rates. High-mass XRBs (HMXBs) are especially problematic because they can get brighter than low-mass XRBs. However, previous estimates of HMXB contamination (based on the optical continuum to get the fraction of HMXBs expected in the nucleus) may be too high. A better approach is to use FUV or H-alpha, which directly trace ongoing star formation. We did this in a sample of 30 late-type galaxies with Chandra data. We calculate the total Expected X-ray Luminosity from XRBs (L_x) for each sample galaxy using existing relationships between X-ray luminosity and SFR. We estimate the fraction of the stellar formation in the nucleus by measuring the fraction of nuclear UV or H-alpha light there (total SFR is from the far infrared). Our Galex data is scaled with a sample of 6 Swift UVOT galaxies to measure with the same aperture size that previous works have used in the B-band. We found that the mean L_x,c for Swift scaled FUV ratios is ~2.025 x 10^36 and the mean L_x,c for H-alpha ratios is 7.693 x 10^35. These luminosities are 1.9 and 5 times smaller than B-band measured luminosities respectively. These results suggest that HMXBs do not contribute as much contamination in these galaxies as previously thought. Therefore, with a lower contamination, estimates of the occupation fraction from late-type galaxies are more reliable.

Occupational Risk for Oral Cancer in Nordic Countries.

PubMed

Tarvainen, Laura; Suojanen, Juho; Kyyronen, Pentti; Lindqvist, Christian; Martinsen, Jan Ivar; Kjaerheim, Kristina; Lynge, Elsebeth; Sparen, Par; Tryggvadottir, Laufey; Weiderpass, Elisabete; Pukkala, Eero

2017-06-01

To evaluate occupational risk for cancer of the tongue, oral cavity or pharynx after adjustment for alcohol and tobacco use. The data covered 14.9 million people and 28,623 cases of cancer of the tongue, oral cavity and pharynx in the Nordic countries 1961-2005. Alcohol consumption by occupation was estimated based on mortality from liver cirrhosis and incidence of liver cancer. Smoking by occupation was estimated based on the incidence of lung cancer. Only few occupations had relative risks of over 1.5 for cancer of the tongue, oral cavity and pharynx. These occupations included dentists, artistic workers, hairdressers, journalists, cooks and stewards, seamen and waiters. Several occupational categories, including dentists, had an increased relative risk of tongue cancer. This new finding remains to be explained but could be related to occupational chemical exposures, increased consumption of alcohol and tobacco products, or infection with human papilloma virus. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

14 CFR Appendix C to Part 1215 - Typical User Activity Timeline

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Typical User Activity Timeline C Appendix C... RELAY SATELLITE SYSTEM (TDRSS) Pt. 1215, App. C Appendix C to Part 1215—Typical User Activity Timeline... mission model. 3 years before launch (Ref. § 1215.109(c). Submit general user requirements to permit...

Effectiveness and mechanism of natural attenuation at a petroleum-hydrocarbon contaminated site.

PubMed

Lv, Hang; Su, Xiaosi; Wang, Yan; Dai, Zhenxue; Liu, Mingyao

2018-05-07

This study applied an integrated method for evaluating the effectiveness and mechanism of natural attenuation (NA) of petroleum-hydrocarbon contaminated groundwater. Site groundwater and soil samples were analysed to characterize spatial and temporal variations in petroleum hydrocarbons, geochemical indicators, microbial diversity and isotopes. The results showed that the area of petroleum hydrocarbon contamination plume decreased almost 60% in four years, indicating the presence of natural attenuation. The 14 C content and sequence analysis indicate that there are more relatively 'old' HCO 3 - that have been produced from petroleum hydrocarbons in the upgradient portion of the contaminated plume, confirming that intrinsic biodegradation was the major factor limiting spread of the contaminated plume. The main degradation mechanisms were identified as sulfate reduction and methanogenesis based on the following: (1) more SO 4 2- have been consumed in the contamination source than downgradient, and the δ 34 S values in the resident SO 4 2- were also more enriched in the contamination source, (2) production of more CH 4 in the contamination source with the δ 13 C values for CH 4 was much lower than that of CO 2 , and the fractionation factor was 1.030-1.046. The results of this study provide significant insight for applying natural attenuation and enhanced bioremediation as alternative options for remediation of petroleum-hydrocarbon contaminated sites. Copyright © 2018 Elsevier Ltd. All rights reserved.

Isolation and characterization of nonhistone chromosomal protein C-14 which stimulates RNA synthesis.

PubMed

James, G T; Yeoman, L C; Matsui, S i; Goldberg, A H; Busch, H

1977-05-31

The nonhistone chromatin protein, C-14, was extracted from chromatin of Novikoff hepatoma ascites cells and isolated in high purity as shown by its migration as a single dense spot on two-dimensional polyacrylamide gels. Its mobility on sodium dodecyl sulfate gels is consistent with a molecular weight of approximately 70 000. The amino acid composition shows that protein C-14 has an acidic:basic amino acid ratio of 1.8. Its amino terminal amino acid is lysine. Protein C-14 stimulated the incorporation of [3H]UMP into RNA by approximately 30% when added to naked DNA and homologous RNA polymerase I. A 30% stimulation of [3H]UMP incorporation into RNA was also found when protein C-14 was added to an E. coli RNA polymerase system containing either E. coli or Novikoff hepatoma DNA.

Chlorophyll a specific Δ14C, δ13C and δ15N values in stream periphyton: implications for aquatic food web studies

NASA Astrophysics Data System (ADS)

Ishikawa, N. F.; Yamane, M.; Suga, H.; Ogawa, N. O.; Yokoyama, Y.; Ohkouchi, N.

2015-07-01

We determined the isotopic composition of chlorophyll a in periphytic algae attached to a streambed substrate (periphyton). The samples were collected from a stream flowing on limestone bedrock in the Seri River, central Japan. Stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) and natural radiocarbon abundances (Δ14C) were measured in chlorophyll a (δ13Cchl, δ15Nchl and Δ14Cchl) and bulk (δ13Cbulk, δ15Nbulk and Δ14Cbulk) for periphyton, pure aquatic primary producer (Cladophora sp.) and terrestrial primary producer (Quercus glauca). Periphyton δ13Cbulk and δ13Cchl values did not necessarily correspond to δ13Cbulk for an algal-grazing specialist (Mayfly larva, Epeorus latifolium), suggesting that periphyton δ13C values do not faithfully trace carbon transfer between primary producers and primary consumers. Periphyton Δ14Cchl values (-258 ‰ in April and -190 ‰ in October) were slightly lower than Δ14Cbulk values (-228 ‰ in April and -179 ‰ in October), but were close to the Δ14C value for dissolved inorganic carbon (DIC) (-217 ± 31 ‰), which is a mixture of weathered carbonates (Δ14C = -1000 ‰) and dissolved atmospheric CO2 (Δ14C approximately +30 ‰ in 2013). Δ14Cchl values were also close to Δ14Cbulk for E. latifolium (-215 ‰ in April and -199 ‰ in October) and Cladophora sp. (-210 ‰), whereas the Δ14Cbulk value for Q. glauca (+27 ‰) was closer to Δ14C for atmospheric CO2. Although the bulk isotopic composition of periphyton is recognised as a surrogate for the photosynthetic algal community, natural periphyton is a mixture of aquatic and terrestrial organic materials. Our results indicate that the bulk periphyton matrix at the study site consists of 89 to 95 % algal carbon (derived from 14C-depleted DIC) and 5 to 11 % terrestrial organic carbon (derived from 14C-enriched atmospheric CO2).

Occupational allergic contact dermatitis caused by epoxy chemicals: occupations, sensitizing products, and diagnosis.

PubMed

Aalto-Korte, Kristiina; Pesonen, Maria; Suuronen, Katri

2015-12-01

Epoxy products are among the most common causes of occupational allergic contact dermatitis. Diglycidyl ether of bisphenol A resin (DGEBA-R) is the most important sensitizer in epoxy systems. To describe patients with occupational allergic contact dermatitis caused by epoxy products. Patients with allergic reactions to epoxy chemicals were chosen from test files (January 1991 to June 2014). Only patients with occupational contact allergy to some component of epoxy resin systems were included. We analysed patch test results, occupation, symptoms, and exposure data. We found a total of 209 cases with occupational contact allergy to epoxy chemicals. The largest occupational groups were painters (n = 41), floor layers (n = 19), electrical industry workers (n = 19), tile setters (n = 16), and aircraft industry workers (n = 15). A total of 82% of the patients reacted to DGEBA-R. Diagnosis of the DGEBA-R-negative patients required testing with m-xylylenediamine, N,N'-tetraglycidyl-4,4'-methylenedianiline, 1,4-butanediol diglycidyl ether, 2,4,6-tris-(dimethylaminomethyl)phenol, diglycidyl ether of bisphenol F resin, N,N'-diglycidyl-4-glycidyloxyaniline, isophoronediamine, 4,4'-diaminodiphenylmethane, diethylenetriamine, and cresyl glycidyl ether. The hands/upper extremities were most commonly affected (69%), but facial symptoms were also frequent (60%). Allergic contact dermatitis caused by to epoxy products cannot always be diagnosed by the use of commercial test substances. Workplace products need to be tested. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Modeling Contamination Migration on the Chandra X-ray Observatory - II

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Swartz, Douglas A.; Tice, Neil W.; Plucinsky, Paul P.; Grant, Catherine E.; Marshall, Herman L.; Vikhlinin, Alexey A.; Tennant, Allyn F.

2013-01-01

During its first 14 years of operation, the cold (about -60C) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), aboard the Chandra X-ray Observatory, has accumulated a growing layer of molecular contamination that attenuates low-energy x rays. Over the past few years, the accumulation rate, spatial distribution, and composition have changed. This evolution has motivated further analysis of contamination migration within and near the ACIS cavity. To this end, the current study employs a higher-fidelity geometric model of the ACIS cavity, detailed thermal modeling based upon temperature data, and a refined model of the molecular transport.

Removal of residual contaminants in petroleum-contaminated soil by Fenton-like oxidation.

PubMed

Lu, Mang; Zhang, Zhongzhi; Qiao, Wei; Guan, Yueming; Xiao, Meng; Peng, Chong

2010-07-15

The degradation of bioremediation residues by hydrogen peroxide in petroleum-contaminated soil was investigated at circumneutral pH using a Fenton-like reagent (ferric ion chelated with EDTA). Batch tests were done on 20 g soil suspended in 60 mL aqueous solution containing hydrogen peroxide and Fe(3+)-EDTA complex under constant stirring. A slurry reactor was used to treat the soil based on the optimal reactant conditions. Contaminants were characterized by Fourier transform infrared spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry. The results showed that the optimal treatment condition was: the molar ratio of hydrogen peroxide to iron=200:1, and pH 7.0. Under the optimum condition, total dichloromethane-extractable organics were reduced from 14,800 to 2300 mg kg(-1) soil when the accumulative H(2)O(2) dosage was 2.45 mol kg(-1) soil during the reactor treatment. Abundance of viable cells was lower in incubated Fenton-like treated soil than in untreated soil. Oxidation of contaminants produced remarkable compositional and structural modifications. A fused ring compound, identified as C(34)H(38)N(1), was found to exhibit the greatest resistance to oxidation. 2010 Elsevier B.V. All rights reserved.

14 CFR Appendix C to Part 27 - Criteria for Category A

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Criteria for Category A C Appendix C to... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Pt. 27, App. C Appendix C to Part 27—Criteria for Category A... tail rotor structure. 29.861(a)—Fire protection of structure, controls, and other parts. 29.901(c...

14 CFR Appendix C to Part 27 - Criteria for Category A

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Criteria for Category A C Appendix C to... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Pt. 27, App. C Appendix C to Part 27—Criteria for Category A... tail rotor structure. 29.861(a)—Fire protection of structure, controls, and other parts. 29.901(c...

Serum proteomic analysis reveals potential serum biomarkers for occupational medicamentosa-like dermatitis caused by trichloroethylene.

PubMed

Huang, Peiwu; Ren, Xiaohu; Huang, Zhijun; Yang, Xifei; Hong, Wenxu; Zhang, Yanfang; Zhang, Hang; Liu, Wei; Huang, Haiyan; Huang, Xinfeng; Wu, Desheng; Yang, Linqing; Tang, Haiyan; Zhou, Li; Li, Xuan; Liu, Jianjun

2014-08-17

Trichloroethylene (TCE) is an industrial solvent with widespread occupational exposure and also a major environmental contaminant. Occupational medicamentosa-like dermatitis induced by trichloroethylene (OMLDT) is an autoimmune disease and it has become one major hazard in China. In this study, sera from 3 healthy controls and 3 OMLDT patients at different disease stages were used for a screening study by 2D-DIGE and MALDI-TOF-MS/MS. Eight proteins including transthyretin (TTR), retinol binding protein 4 (RBP4), haptoglobin, clusterin, serum amyloid A protein (SAA), apolipoprotein A-I, apolipoprotein C-III and apolipoprotein C-II were found to be significantly altered among the healthy, acute-stage, healing-stage and healed-stage groups. Specifically, the altered expression of TTR, RBP4 and haptoglobin were further validated by Western blot analysis and ELISA. Our data not only suggested that TTR, RBP4 and haptoglobin could serve as potential serum biomarkers of OMLDT, but also indicated that measurement of TTR, RBP4 and haptoglobin or their combination could help aid in the diagnosis, monitoring the progression and therapy of the disease. Copyright © 2014. Published by Elsevier Ireland Ltd.

Effect of anthropogenic activities on atmospheric 14C content and radiocarbon chronologies of the future.

NASA Astrophysics Data System (ADS)

Hajdas, Irka

2017-04-01

Radiocarbon (14C) is a naturally produced radioactive isotope of carbon (T1/2=5700 yrs), which is continuously produced in the atmosphere. This occur in a reaction of thermal neutrons, which are secondary particles, products of cosmic rays reactions with the atmosphere, with nitrogen that is commonly present in the atmosphere. Until the mid 19th century the natural concentration showed temporal variability around the mean value (14C / 12C ratio =1.8 x 10-12). However anthropogenic activity created 2 types effects that are changing the 14C concentration of the atmosphere. Industrial revolution triggered adding 14C free (old) carbon that originates from the burning of fossil fuels (Suess effect). This in the late 19th century and early 20th century atmosphere was becoming older. The nuclear tests in the 1950ties caused additional production of radiocarbon atoms (artificial). The effect has been almost double of the natural production and created an excess 14C activity in the atmosphere and in terrestrial carbon bearing materials. The bomb produced 14C has been identified soon after the tests started but the peak (ca. 100% above the normal levels) reached its maximum in 1963 in the northern Hemisphere where most of the tests took place. In the southern Hemisphere the bomb peak reached lower values (ca. 80 % of normal level) and was delayed by ca. 2 years. After the ban on nuclear tests the atmospheric 14C content began to decrease mainly due to the uptake by the ocean but also due to the above mentioned addition old carbon. Continuous monitoring of the atmospheric 14C ratio during the years that followed the nuclear tests, provide basis for environmental studies. Applications range from studies of ocean circulation, CO2 uptake, carbon storage in soils and peat, root turn over time to the medical, forensic and detection of forgeries. However, the so called ' 14C bomb peak' nearly disappeared due to the combined effect of ocean uptake of CO2 and an input to the

Assessing occupational exposure to sea lamprey pesticides.

PubMed

Ceballos, Diana M; Beaucham, Catherine C; Kurtz, Kristine; Musolin, Kristin

2015-01-01

Sea lampreys are parasitic fish found in lakes of the United States and Canada. Sea lamprey is controlled through manual application of the pesticides 3-trifluoromethyl-4-nitrophenol (TFM) and Bayluscide(TM) into streams and tributaries. 3-Trifluoromethyl-4-nitrophenol may cause irritation and central nervous system depression and Bayluscide may cause irritation, dermatitis, blisters, cracking, edema, and allergic skin reactions. To assess occupational exposures to sea lamprey pesticides. We developed a wipe method for evaluating surface and skin contamination with these pesticides. This method was field tested at a biological field station and at a pesticide river application. We also evaluated exposures using control banding tools. We verified TFM surface contamination at the biological station. At the river application, we found surfaces and worker's skin contaminated with pesticides. We recommended minimizing exposures by implementing engineering controls and improved use of personal protective equipment.

Mobility Studies of (14)C-Chlorpyrifos in Malaysian Oil Palm Soils.

PubMed

Halimah, Muhamad; Ismail, B Sahid; Nashriyah, Mat; Maznah, Zainol

2016-01-01

The mobility of (14)C-chlorpyrifos using soil TLC was investigated in this study. It was found that chlorpyrifos was not mobile in clay, clay loam and peat soil. The mobility of (14)C-chlorpyrifos and non-labelled chlorpyrifos was also tested with silica gel TLC using three types of developing solvent hexane (100%), hexane:ethyl acetate (95:5, v/v); and hexane:ethyl acetate (98:2, v/v). The study showed that both the (14)C-labelled and non-labelled chlorpyrifos have the same Retardation Factor (Rf) for different developing solvent systems. From the soil column study on mobility of chlorpyrifos, it was observed that no chlorpyrifos residue was found below 5 cm depth in three types of soil at simulation rainfall of 20, 50 and 100 mm. Therefore, the soil column and TLC studies have shown similar findings in the mobility of chlorpyrifos.

The biosynthesis of polysaccharides. Incorporation of d-[1-14C]glucose and d-[6-14C]glucose into plum-leaf polysaccharides

PubMed Central

Andrews, P.; Hough, L.; Picken, J. M.

1965-01-01

1. The utilization of specifically labelled d-glucose in the biosynthesis of plum-leaf polysaccharides has been studied. After these precursors had been metabolized in plum leaves, the polysaccharides were isolated from the leaves, and their monosaccharide constituents isolated and purified. 2. Both the specific activities and the distribution of 14C along the carbon chains of the monosaccharides were determined. Significant 14C activity was found in units of d-galactose, d-glucose, d-xylose and l-arabinose, but their specific activities varied widely. The labelling patterns suggest that in the leaves the other monosaccharides all arise directly from d-glucose without any skeletal change in the carbon chain, other than the loss of a terminal carbon atom in the synthesis of pentoses. 3. The results indicated that within the leaf there are various precursor pools for polysaccharide synthesis and that these pools are not in equilibrium with one another. PMID:14342252

Occupational exposure to carcinogens: Benzene, pesticides and fibers

PubMed Central

Falzone, Luca; Marconi, Andrea; Loreto, Carla; Franco, Sabrina; Spandidos, Demetrios A.; Libra, Massimo

2016-01-01

It is well known that the occupational exposure to contaminants and carcinogens leads to the development of cancer in exposed workers. In the 18th century, Percivall Pott was the first to hypothesize that chronic exposure to dust in the London chimney sweeps was associated with an increased risk of developing cancer. Subsequently a growing body of evidence indicated that other physical factors were also responsible for oncogenic mutations. Over the past decades, many carcinogens have been found in the occupational environment and their presence is often associated with an increased incidence of cancer. Occupational exposure involves several factors and the association between carcinogens, occupational exposure and cancer is still unclear. Only a fraction of factors is recognized as occupational carcinogens and for each factor, there is an increased risk of cancer development associated with a specific work activity. According to the International Agency for Research on Cancer (IARC), the majority of carcinogens are classified as ‘probable’ and ‘possible’ human carcinogens, while, direct evidence of carcinogenicity is provided in epidemiological and experimental studies. In the present review, exposures to benzene, pesticides and mineral fibers are discussed as the most important cancer risk factors during work activities. PMID:27748850

Occupational exposure to carcinogens: Benzene, pesticides and fibers (Review).

PubMed

Falzone, Luca; Marconi, Andrea; Loreto, Carla; Franco, Sabrina; Spandidos, Demetrios A; Libra, Massimo

2016-11-01

It is well known that the occupational exposure to contaminants and carcinogens leads to the development of cancer in exposed workers. In the 18th century, Percivall Pott was the first to hypothesize that chronic exposure to dust in the London chimney sweeps was associated with an increased risk of developing cancer. Subsequently a growing body of evidence indicated that other physical factors were also responsible for oncogenic mutations. Over the past decades, many carcinogens have been found in the occupational environment and their presence is often associated with an increased incidence of cancer. Occupational exposure involves several factors and the association between carcinogens, occupational exposure and cancer is still unclear. Only a fraction of factors is recognized as occupational carcinogens and for each factor, there is an increased risk of cancer development associated with a specific work activity. According to the International Agency for Research on Cancer (IARC), the majority of carcinogens are classified as 'probable' and 'possible' human carcinogens, while, direct evidence of carcinogenicity is provided in epidemiological and experimental studies. In the present review, exposures to benzene, pesticides and mineral fibers are discussed as the most important cancer risk factors during work activities.

Toxic C17-Sphinganine Analogue Mycotoxin, Contaminating Tunisian Mussels, Causes Flaccid Paralysis in Rodents

PubMed Central

Marrouchi, Riadh; Benoit, Evelyne; Le Caer, Jean-Pierre; Belayouni, Nawel; Belghith, Hafedh; Molgó, Jordi; Kharrat, Riadh

2013-01-01

Severe toxicity was detected in mussels from Bizerte Lagoon (Northern Tunisia) using routine mouse bioassays for detecting diarrheic and paralytic toxins not associated to classical phytoplankton blooming. The atypical toxicity was characterized by rapid mouse death. The aim of the present work was to understand the basis of such toxicity. Bioassay-guided chromatographic separation and mass spectrometry were used to detect and characterize the fraction responsible for mussels’ toxicity. Only a C17-sphinganine analog mycotoxin (C17-SAMT), with a molecular mass of 287.289 Da, was found in contaminated shellfish. The doses of C17-SAMT that were lethal to 50% of mice were 750 and 150 μg/kg following intraperitoneal and intracerebroventricular injections, respectively, and 900 μg/kg following oral administration. The macroscopic general aspect of cultures and the morphological characteristics of the strains isolated from mussels revealed that the toxicity episodes were associated to the presence of marine microfungi (Fusarium sp., Aspergillus sp. and Trichoderma sp.) in contaminated samples. The major in vivo effect of C17-SAMT on the mouse neuromuscular system was a dose- and time-dependent decrease of compound muscle action potential amplitude and an increased excitability threshold. In vitro, C17-SAMT caused a dose- and time-dependent block of directly- and indirectly-elicited isometric contraction of isolated mouse hemidiaphragms. PMID:24287956

Pharmacokinetics of 14 C-ortho-phenylphenol following intravenous administration in pigs.

PubMed

Nixon, Emma; Brooks, James D; Routh, Patricia A; Chittenden, Jason T; Baynes, Ronald E

2017-04-01

Workers in the USA are exposed to industrial formulations, which may be toxic. These formulations often contain preservatives or biocides such as ortho-phenylphenol (OPP). There are limited data describing OPP following intravenous administration to assess truly the clearance of this chemical in humans and other species. In vivo experiments were conducted in pigs to determine related pharmacokinetic parameters. 14 C-OPP was administered as an intravenous bolus dose. Blood, feces, urine and tissue samples were collected for analysis by liquid scintillation. Data were analyzed using non-compartmental and compartmental pharmacokinetic model approaches. These data fitted a three-compartment model and showed that the half-life of 14 C-OPP following the intravenous bolus in pigs was 46.26 ± 10.01 h. The kidneys play a crucial role in clearance of 14 C-OPP with a large percentage of the dose being found in the urine (70.3 ± 6.9% dose). Comparisons with other species suggest that 14 C-OPP clearance in pigs (2.48 ml h -1  kg -1 ) is less than that in humans (18.87 ml h -1  kg -1 ) and rats (35.51 ml h -1  kg -1 ). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Quantitative assessment of bio-aerosols contamination in indoor air of University dormitory rooms

PubMed Central

Hayleeyesus, Samuel Fekadu; Ejeso, Amanuel; Derseh, Fikirte Aklilu

2015-01-01

Objectives The purpose of this study is to provide insight into how students are exposed to indoor bio-aerosols in the dormitory rooms and to figure out the major possible factors that govern the contamination levels. Methodology The Bio-aerosols concentration level of indoor air of thirty dormitory rooms of Jimma University was determined by taking 120 samples. Passive air sampling technique; the settle plate method using open Petri-dishes containing different culture media was employed to collect sample twice daily. Results The range of bio-aerosols contamination detected in the dormitory rooms was 511–9960 CFU/m3 for bacterial and 531–6568 CFU/m3 for fungi. Based on the criteria stated by WHO expert group, from the total 120 samples 95 of the samples were above the recommended level. The statistical analysis showed that, occupancy were significantly affected the concentrations of bacteria that were measured in all dormitory rooms at 6:00 am sampling time (p-value=0.000) and also the concentrations of bacteria that were measured in all dormitory rooms were significantly different to each other (p-value=0.013) as of their significance difference in occupancy (p-value=0.000). Moreover, there were a significant different on the contamination level of bacteria at 6:00 am and 7:00 pm sampling time (p=0.015), whereas there is no significant difference for fungi contamination level for two sampling times (p= 0.674). Conclusion There is excessive bio-aerosols contaminant in indoor air of dormitory rooms of Jimma University and human occupancy produces a marked concentration increase of bacterial contamination levels and most fungi species present into the rooms air of Jimma University dormitory were not human-borne. PMID:26609289

Cutaneous Uptake of 14C-HD Vapor by the Hairless Guinea Pig.

DTIC Science & Technology

1996-10-01

guinea pig (HGP) is used by our laboratory to model the human cutaneous response to sulfur mustard (HD) exposure. We have determined the HD content in the skin of HOP after 7-minute exposures to vapors saturated with a mixture of HD and 14C-HD. Concentration/time (C1) values in the range of 2 mg/sq cm/min were determined by counting skin 14C disintegrations per minute (dpm) in animals euthanized immediately after exposure. These values are similar to human penetration rates obtained by other investigators. A direct relationship between C1 and relative humidity was

Neutron capture cross section of {sup 14}C of astrophysical interest studied by Coulomb breakup of {sup 15}C

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

Nakamura, T.; Fukuda, N.; Aoi, N.

2009-03-15

The neutron capture reaction on {sup 14}C leading to the {sup 15}C ground state, which plays an important role in various nucleosynthesis processes, has been studied using the Coulomb breakup of {sup 15}C on a Pb target at 68 MeV/nucleon. The breakup cross section has been converted into the energy-dependent neutron capture cross section using the principle of detailed balance. The energy spectrum shows typical p-wave neutron capture characteristics, which is explained by the fact that the ground state of {sup 15}C possesses a strong single-particle s-wave component and a moderate-sized neutron halo structure. The capture cross section for themore » {sup 14}C(n,{gamma}){sup 15}C reaction derived from the present experiment has been found to be consistent with the most recent data, directly measured using a {sup 14}C target. This result assures the validity of the Coulomb breakup method in deriving the neutron capture cross section for neutron-rich nuclei.« less

sup 14 C-urea breath test for the detection of Helicobacter pylori

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

Veldhuyzen van Zanten, S.J.; Tytgat, K.M.; Hollingsworth, J.

1990-04-01

The high urease activity of Helicobacter pylori can be used to detect this bacterium by noninvasive breath tests. We have developed a {sup 14}C-urea breath test which uses 5 microCi {sup 14}C with 50 mg nonradioactive urea. Breath samples are collected at baseline and every 30 min for 2 h. Our study compared the outcome of the breath test to the results of histology and culture of endoscopically obtained gastric biopsies in 84 patients. The breath test discriminated well between the 50 positive patients and the 34 patients negative for Helicobacter pylori: the calculated sensitivity was 100%, specificity 88%, positivemore » predictive value 93%, and negative predictive value 100%. Treatment with bismuth subsalicylate and/or ampicillin resulted in lower counts of exhaled {sup 14}CO{sub 2} which correlated with histological improvement in gastritis. The {sup 14}C-urea breath test is a better gold standard for the detection of Helicobacter pylori than histology and/or culture.« less

14 CFR Appendix C to Part 23 - Basic Landing Conditions

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Basic Landing Conditions C Appendix C to Part 23 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... extension (hydraulic shock absorber) Note (2) Note (2) Note (2) Note (2) Note (2). Shock absorber deflection...

14 CFR Appendix C to Part 141 - Instrument Rating Course

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Instrument Rating Course C Appendix C to... Rating Course 1. Applicability. This appendix prescribes the minimum curriculum for an instrument rating course and an additional instrument rating course, required under this part, for the following ratings...

14 CFR Appendix C to Part 141 - Instrument Rating Course

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Instrument Rating Course C Appendix C to... Rating Course 1. Applicability. This appendix prescribes the minimum curriculum for an instrument rating course and an additional instrument rating course, required under this part, for the following ratings...

14 CFR Appendix C to Part 141 - Instrument Rating Course

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Instrument Rating Course C Appendix C to... Rating Course 1. Applicability. This appendix prescribes the minimum curriculum for an instrument rating course and an additional instrument rating course, required under this part, for the following ratings...

Biliary excretion of intravenous (/sup 14/C) omeprazole in humans

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

Lind, T.; Andersson, T.; Skanberg, I.O.

1987-11-01

We have studied the biliary excretion of (/sup 14/C) omeprazole in humans. The study was performed in eight healthy subjects and the technique used was based on multiple marker dilution principles with double-lumen tubes placed in both the stomach and intestine. The results obtained show a 16% biliary excretion of (/sup 14/C) omeprazole. These data suggest a minimal spillover of omeprazole from the gastric mucosa into the gastric lumen in humans. The results also agree with previous data of the fecal recovery of radiolabeled omeprazole that suggest that the fecal excretion of intravenous omeprazole in humans is entirely accounted formore » by biliary excretion.« less

Characterization of Carbon-Contaminated B4C-Coated Optics after Chemically Selective Cleaning with Low-Pressure RF Plasma.

PubMed

Moreno Fernández, H; Rogler, D; Sauthier, G; Thomasset, M; Dietsch, R; Carlino, V; Pellegrin, E

2018-01-22

Boron carbide (B 4 C) is one of the few materials that is expected to be most resilient with respect to the extremely high brilliance of the photon beam generated by free electron lasers (FELs) and is thus of considerable interest for optical applications in this field. However, as in the case of many other optics operated at light source facilities, B 4 C-coated optics are subject to ubiquitous carbon contaminations. Carbon contaminations represent a serious issue for the operation of FEL beamlines due to severe reduction of photon flux, beam coherence, creation of destructive interference, and scattering losses. A variety of B 4 C cleaning technologies were developed at different laboratories with varying success. We present a study regarding the low-pressure RF plasma cleaning of carbon contaminated B 4 C test samples via inductively coupled O 2 /Ar, H 2 /Ar, and pure O 2 RF plasma produced following previous studies using the same ibss GV10x downstream plasma source. Results regarding the chemistry, morphology as well as other aspects of the B 4 C optical coating before and after the plasma cleaning are reported. We conclude that among the above plasma processes only plasma based on pure O 2 feedstock gas exhibits the required chemical selectivity for maintaining the integrity of the B 4 C optical coatings.

Bio-Carbon Accounting for Bio-Oil Co-Processing: 14C and 13C/ 12C

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

Mora, Claudia I.; Li, Zhenghua; Vance, Zachary

This is a powerpoint presentation on bio-carbon accounting for bio-oil co-processing. Because of the overlapping range in the stable C isotope compositions of fossil oils and biooils from C3-type feedstocks, it is widely thought that stable isotopes are not useful to track renewable carbon during co-production. In contrast, our study demonstrates the utility of stable isotopes to: • capture a record of renewable carbon allocation between FCC products of co-processing • record changes in carbon apportionments due to changes in reactor or feed temperature Stable isotope trends as a function of percent bio-oil in the feed are more pronounced whenmore » the δ 13C of the bio-oil endmember differs greatly from the VGO (i.e., it has a C4 biomass source–corn stover, switch grass, Miscanthus, sugarcane– versus a C3 biomass source– pine, wheat, rice, potato), but trends on the latter case are significant for endmember differences of just a few permil. The correlation between measured 14C and δ 13C may be useful as an alternative to carbon accounting, but the relationship must first be established for different bio-oil sources.« less

Occupational contact dermatitis caused by D-limonene.

PubMed

Pesonen, Maria; Suomela, Sari; Kuuliala, Outi; Henriks-Eckerman, Maj-Len; Aalto-Korte, Kristiina

2014-11-01

Limonene is widely used as a fragrance substance and solvent in cleansing products. Oxidized limonene is a frequent contact allergen among consumers of cosmetics, personal care products, and scented household cleaning products. Less is known about the sources of occupational exposure and occupational contact dermatitis caused by limonene. To report 14 patients with occupational contact allergy to limonene. The patients were examined in 2008-2013. An in-house preparation of oxidized limonene was patch tested as 3% and 5% in petrolatum from 2008 to August 2010, and after this as 3%, 1% and 0.3% pet. From 2012 onwards, a commercial test substance of limonene hydroperoxides was also used. We assessed the patients' occupational and domestic exposure to limonene. Occupational limonene allergy was observed in workers who used limonene-containing machine-cleaning detergents and hand cleansers, and in workers who used limonene-containing surface cleaners and dishwashing liquids similar to those used by consumers. In 3 cases, the occupational limonene allergy resulted from work-related use of limonene-containing, leave-on cosmetic products. Limonene is a frequent occupational sensitizer in hand cleansers and cleaning products. Occupational limonene contact allergy may also be caused by exposure to cosmetic products scented with limonene. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Nuclear reactions with 11C and 14O radioactive ion beams

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

Guo, Fanqing

2004-01-01

Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has been developed at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. The current BEARS provides two RIBs: a 11C beam of up to 2x10 8 pps intensity onmore » target and an 14O beam of up to 3x10 4 pps intensity. While the development of the 11C beam has been relatively easy, a number of challenges had to be overcome to obtain the 14O beam. The excellent 11C beam has been used to investigate several reactions. The first was the 197Au( 11C,xn) 208-xnAt reaction, which was used to measure excitation functions for the 4n to 8n exit channels. The measured cross sections were generally predicted quite well using the fusion-evaporation code HIVAP. Possible errors in the branching ratios of ?? decays from At isotopes as well as the presence of incomplete fusion reactions probably contribute to specific overpredictions. 15F has been investigated by the p( 14O,p)14O reaction with the ERSIKTT technology. Several 14O+p runs have been performed. Excellent energy calibration was obtained using resonances from the p( 14N,p) 14N reaction in inverse kinematics, and comparing the results to those obtained earlier with normal kinematics. The differences between 14N+p and 14O+p in the stopping power function have been evaluated for better energy calibration. After careful calibration, the energy levels of 15F were fitted with an R-matrix calculation. Spins and parities were assigned to the two observed resonances. This new measurement of the 15F ground state supports the

Measurement of glucuronidation by isolated rat liver cells using [14C]fructose.

PubMed

Dawson, J; Knowles, R G; Pogson, C I

1992-03-03

We have developed a simple and sensitive method for the study of the relative rates of glucuronidation of compounds, in isolated liver cells, based on the incorporation of 14C from fructose into glucuronide conjugates. Liver cells from fasted rats are used to minimize any reduction of the specific activity by glycogenolysis. Although rates of glucuronidation are lower in isolated liver cells from fasted rats than in those from fed rats, because of a reduction in the concentration of UDP-glucuronic acid, it is possible to compare the rates of glucuronidation of different compounds. Radiolabelled glucuronides are separated from [14C]fructose and [14C]glucose, produced by the liver cells, by normal-phase HPLC on a polar amino-cyano column. The specific activity of the glucuronide was found to be approximately 50% of that of the [14C]fructose. Absolute amounts of glucuronide can be determined by measuring the specific activity of the [14C]glucose, also produced by liver cells from fructose, which reflects that of the glucose-6-phosphate and hence the UDP-glucuronic acid used for glucuronidation, although for the measurement of relative rates this would not be necessary. We have used this method to examine the kinetics of the glucuronidation of N-acetyl-p-aminophenol (acetaminophen), 4-nitrophenol and 1-naphthol in isolated rat liver cells. The method should be applicable to the study of the rates of glucuronidation of a range of aglycones and, unlike other methods, does not require glucuronide standards or radiolabelled aglycone.

A numerical approach to 14C wiggle-match dating of organic deposits: best fits and confidence intervals

NASA Astrophysics Data System (ADS)

Blaauw, Maarten; Heuvelink, Gerard B. M.; Mauquoy, Dmitri; van der Plicht, Johannes; van Geel, Bas

2003-06-01

14C wiggle-match dating (WMD) of peat deposits uses the non-linear relationship between 14C age and calendar age to match the shape of a sequence of closely spaced peat 14C dates with the 14C calibration curve. A numerical approach to WMD enables the quantitative assessment of various possible wiggle-match solutions and of calendar year confidence intervals for sequences of 14C dates. We assess the assumptions, advantages, and limitations of the method. Several case-studies show that WMD results in more precise chronologies than when individual 14C dates are calibrated. WMD is most successful during periods with major excursions in the 14C calibration curve (e.g., in one case WMD could narrow down confidence intervals from 230 to 36 yr).

Factors associated with occupational exposure to biological material among nursing professionals.

PubMed

Negrinho, Nádia Bruna da Silva; Malaguti-Toffano, Silmara Elaine; Reis, Renata Karina; Pereira, Fernanda Maria Vieira; Gir, Elucir

2017-01-01

to identify factors associated with occupational exposure to biological material among nursing professionals. a cross-sectional study was conducted in a high complexity hospital of a city in the state of São Paulo, Brazil. Nursing professionals were interviewed from March to November 2015. All ethical aspects were observed. among the 226 professionals interviewed, 17.3% suffered occupational exposure to potentially contaminated biological material, with 61.5% being percutaneous. Factors such as age (p=0.003), professional experience in nursing (p=0.015), and experience at the institution (p=0.032) were associated with the accidents with biological material. most accidents with biological material among nursing professionals were percutaneous. Age, professional experience, and experience at the institution were considered factors associated with occupational exposure.

Global aquifers dominated by fossil groundwaters but wells vulnerable to modern contamination

NASA Astrophysics Data System (ADS)

Jasechko, Scott; Perrone, Debra; Befus, Kevin M.; Bayani Cardenas, M.; Ferguson, Grant; Gleeson, Tom; Luijendijk, Elco; McDonnell, Jeffrey J.; Taylor, Richard G.; Wada, Yoshihide; Kirchner, James W.

2017-06-01

The vulnerability of groundwater to contamination is closely related to its age. Groundwaters that infiltrated prior to the Holocene have been documented in many aquifers and are widely assumed to be unaffected by modern contamination. However, the global prevalence of these `fossil' groundwaters and their vulnerability to modern-era pollutants remain unclear. Here we analyse groundwater carbon isotope data (12C, 13C, 14C) from 6,455 wells around the globe. We show that fossil groundwaters comprise a large share (42-85%) of total aquifer storage in the upper 1 km of the crust, and the majority of waters pumped from wells deeper than 250 m. However, half of the wells in our study that are dominated by fossil groundwater also contain detectable levels of tritium, indicating the presence of much younger, decadal-age waters and suggesting that contemporary contaminants may be able to reach deep wells that tap fossil aquifers. We conclude that water quality risk should be considered along with sustainable use when managing fossil groundwater resources.

Modeling Contamination Migration on the Chandra X-ray Observatory II

NASA Technical Reports Server (NTRS)

O'Dell, Steve; Swartz, Doug; Tice, Neil; Plucinsky, Paul; Grant, Catherine; Marshall, Herman; Vikhlinin, Alexey

2013-01-01

During its first 14 years of operation, the cold (about -60degC) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), aboard the Chandra X-ray Observatory, has accumulated a growing layer of molecular contamination that attenuates low-energy x rays. Over the past few years, the accumulation rate, spatial distribution, and composition may have changed, perhaps partially related to changes in the operating temperature of the ACIS housing. This evolution of the accumulation of the molecular contamination has motivated further analysis of contamination migration on the Chandra X-ray Observatory, particularly within and near the ACIS cavity. To this end, the current study employs a higher-fidelity geometric model of the ACIS cavity, detailed thermal modeling based upon monitored temperature data, and an accordingly refined model of the molecular transport.

Localization of 14C-labeled 2% lidocaine hydrochloride after intraosseous anesthesia in the rabbit.

PubMed

Goto, Takashi; Mamiya, Hideki; Ichinohe, Tatsuya; Kaneko, Yuzuru

2011-10-01

The purpose of this study was to investigate the tissue distribution of lidocaine hydrochloride in mandibular bone marrow after intraosseous anesthesia (IOA) in rabbits. We used macroautoradiography to examine the tissue distribution of a (14)C-labeled 2% lidocaine hydrochloride solution containing 1:80,000 epinephrine ((14)C-lidocaine). Under general anesthesia, (14)C-lidocaine was injected intraosseously or paraperiosteally. After IOA, animals were divided into three groups and observed at 1 (IOA-1), 5 (IOA-5), and 10 minutes (IOA-10) after injection. After infiltration anesthesia (IA), animals were observed at 1 minute after injection. The accumulation of (14)C-lidocaine was observed around the injection site in both the IA and the IOA groups. Paraperiosteally injected (14)C-lidocaine diffused to the surrounding tissues such as the lip, whereas IOA showed concentrated accumulation around the root apex throughout the experiment. The distribution area was significantly smaller in the IOA-1 group than in the IA group. The distribution area in the IOA-5 group was larger than those in the IOA-1 and IOA-10 groups. The accumulation of (14)C-lidocaine injected by IOA in rabbits was concentrated around the root apex. These results may explain the rapid onset time of IOA. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

14C Terrestrial Ages of Meteorites from Desert Regions: Algeria and Australia

NASA Astrophysics Data System (ADS)

Jull, A. J. T.; Wlotzka, F.; Bevan, A. W. R.; Brown, S. T.; Donahue, D. J.

1993-07-01

The terrestrial age or residence time on the Earth's surface is important in determining the history of a meteorite. Carbon-14 has been used for a terrestrial-age indicator since 1962 [1,2]. Since 1984, small samples of meteorites of 0.1 to 0.5 g have been dated using accelerator mass spectrometry [3-5]. The precision of terrestrial age estimates is limited by the accuracy to which the saturated activity of ^14C in the meteorite is known. Jull et al. [4,5] used Bruderheim and some other chondrites to establish a saturated activity reference level. It is important to be aware that ^14C can vary with the depth and size of the object, and ^14C as a function of accurate depth has so far been measured only for one object, Knyahinya [7]. Carbon-14 is of particular interest in warmer climatic regions, where the storage time before a meteorite weathers away is expected to be much less than other locations, for example, Antarctica. This view was originally based on the work of Boeckl [7], who determined a "weathering half life" of some 3500 yr for chondrites from the southwestern U.S. This work was reinvestigated [5] and it was determined that the ^14C age distribution of the meteorites was longer than the earlier report. We have studied ^14C ages of meteorites from Roosevelt County, New Mexico [8], and from the western Libyan desert [9]. In both these areas meteorites of ages as old as 35,000 yr are observed, and the mean survival time at both locations is well over 10,000 yr. We have studied the ^14C age distribution of a large number of meteorites from Acfer, Algeria, and the Nullarbor Plain, Australia. Figure 1 presents the ^14C age distribution of Acfer samples compared to some other locations where a substantial number of ^14C ages have been obtained. The Algerian site shows a simple exponential dependence of terrestrial age vs. time, and no meteorites of >25 K.y. age. This is in contrast to the results from the southwestern U.S. [7] and from Roosevelt County [8]. One

Water exposure--challenging differences between occupations.

PubMed

Meding, Birgitta; Anveden Berglind, Ingegärd; Alderling, Magnus; Lindahl, Gunborg; Wrangsjö, Karin

2016-01-01

Few studies have compared water exposure between different occupations in the general population. To investigate and compare the extent of occupational water exposure, with a focus on service, healthcare and production occupations previously classified as involving a high risk for hand eczema. In two public health surveys (2006 and 2010), a validated question regarding occupational water exposure was answered by 18 342 and 15,736 gainfully employed individuals, respectively. Exposure for ≥ 0.5 h/day was reported by 17.5% and 16.3% (p = 0.020) for the respective years, and exposure for > 2 h/day by 7.8% and 7.7% (p = 0.73). Exposure in women was almost twice as high as in men for both years (p ≤ 0.001) and exposure levels (p < 0.001). Exposure for > 2 h/day was more common in high-risk occupations in service and healthcare than in non-high-risk occupations [prevalence proportion ratios of 16.7 (95%CI: 14.0-20.0) and 8.3 (95%CI: 6.9-9.9), respectively]. Exposure was highest in service occupations, where 44.6% reported exposure for > 2 h/day in 2010, and kitchen work, cleaning and hairdressing dominated. In healthcare, the corresponding figure was 22.0%. Challenging differences in water exposure between occupational groups were found, and extensive water exposure was reported in a number of occupations previously classified as involving a high risk for hand eczema. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

29 CFR Appendix B to Subpart C of... - Figures C-1 through C-16

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 9 2013-07-01 2013-07-01 false Figures C-1 through C-16 B Appendix B to Subpart C of Part 1928 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR AGRICULTURE Roll-Over Protective...

Occupational risk for Legionella infection among dental healthcare workers: meta-analysis in occupational epidemiology.

PubMed

Petti, Stefano; Vitali, Matteo

2017-07-13

The occupational risk for Legionella infection among dental healthcare workers (DHCWs) is conjectured because of the risk of routine inhalation of potentially contaminated aerosols produced by the dental instruments. Nevertheless, occupational epidemiology studies are contrasting. This meta-analysis assessed the level of scientific evidence regarding the relative occupational risk for Legionella infection among DHCWs. Literature search was performed without time and language restrictions, using broad data banks (PubMed, Scopus, Web of Science, GOOGLE Scholar) and generic keywords ('legionella' AND 'dent*'). Analytical cross-sectional studies comparing prevalence of high serum Legionella antibody levels in DHCWs and occupationally unexposed individuals were considered. The relative occupational risk was assessed through prevalence ratio (PR) with 95% CI. Between-study heterogeneity was assessed (Cochran's Q test) and was used to choose the meta-analytic method. Study quality (modified Newcastle-Ottawa Scale) and publication bias (Begg and Mazumdar's test, Egger and colleagues' test, trim and fill R 0 method) were assessed formally and considered for the sensitivity analysis. Sensitivity analysis to study inclusion, subgroup analyses (dental staff categories; publication year, before vs after 1998, ie, 5 years after the release by the Centers for Disease Control and Prevention of the infection control guidelines in dental healthcare setting) were performed. Seven studies were included (2232 DHCWs, 1172 occupationally unexposed individuals). No evidence of publication bias was detected. The pooled PR estimate was statistically non-significant at 95% level (1.7; 95% CI 0.8 to 3.2), study-quality adjustment did not change the PR considerably (PR, 1.5; 95% CI 0.5 to 4.1). PR was statistically significant before 1998 and no longer significant after 1998. Subgroup analysis according to DHCW categories was inconclusive. There is no scientific evidence that DHCWs are

14CO2 analysis of soil gas: Evaluation of sample size limits and sampling devices

NASA Astrophysics Data System (ADS)

Wotte, Anja; Wischhöfer, Philipp; Wacker, Lukas; Rethemeyer, Janet

2017-12-01

Radiocarbon (14C) analysis of CO2 respired from soils or sediments is a valuable tool to identify different carbon sources. The collection and processing of the CO2, however, is challenging and prone to contamination. We thus continuously improve our handling procedures and present a refined method for the collection of even small amounts of CO2 in molecular sieve cartridges (MSCs) for accelerator mass spectrometry 14C analysis. Using a modified vacuum rig and an improved desorption procedure, we were able to increase the CO2 recovery from the MSC (95%) as well as the sample throughput compared to our previous study. By processing series of different sample size, we show that our MSCs can be used for CO2 samples of as small as 50 μg C. The contamination by exogenous carbon determined in these laboratory tests, was less than 2.0 μg C from fossil and less than 3.0 μg C from modern sources. Additionally, we tested two sampling devices for the collection of CO2 samples released from soils or sediments, including a respiration chamber and a depth sampler, which are connected to the MSC. We obtained a very promising, low process blank for the entire CO2 sampling and purification procedure of ∼0.004 F14C (equal to 44,000 yrs BP) and ∼0.003 F14C (equal to 47,000 yrs BP). In contrast to previous studies, we observed no isotopic fractionation towards lighter δ13C values during the passive sampling with the depth samplers.

Influence of increasing combustion temperature on the AMS 14C dating of modern crop phytoliths

PubMed Central

Yin, Jinhui; Yang, Xue; Zheng, Yonggang

2014-01-01

Several attempts have been made to directly date phytoliths, but most 14C results are not consistent with other independent chronologies. Due to the limited dataset, there is not a clear explanation for these discrepancies. Herein, we report the 14C ages of phytolith-occluded carbon (PhytOC) from contemporary rice and millet crops that were combusted at different temperatures to investigate the relationship between the combustion temperature and resulting 14C age. Our results show that the 14C age of PhytOC increases directly with combustion temperature (up to 1100°C) and results in age overestimations of hundreds of years. Considerably older ages are observed at higher temperatures, suggesting that it may be possible to distinguish between two fractions of organic carbon in phytoliths: labile and recalcitrant carbon. These findings challenge the assumption that PhytOC is homogeneous, an assumption made by those who have previously attempted to directly date phytoliths using 14C. PMID:25288281

Influence of increasing combustion temperature on the AMS 14C dating of modern crop phytoliths.

PubMed

Yin, Jinhui; Yang, Xue; Zheng, Yonggang

2014-10-07

Several attempts have been made to directly date phytoliths, but most (14)C results are not consistent with other independent chronologies. Due to the limited dataset, there is not a clear explanation for these discrepancies. Herein, we report the (14)C ages of phytolith-occluded carbon (PhytOC) from contemporary rice and millet crops that were combusted at different temperatures to investigate the relationship between the combustion temperature and resulting (14)C age. Our results show that the (14)C age of PhytOC increases directly with combustion temperature (up to 1100°C) and results in age overestimations of hundreds of years. Considerably older ages are observed at higher temperatures, suggesting that it may be possible to distinguish between two fractions of organic carbon in phytoliths: labile and recalcitrant carbon. These findings challenge the assumption that PhytOC is homogeneous, an assumption made by those who have previously attempted to directly date phytoliths using (14)C.

Coral skeletal carbon isotopes (δ13C and Δ14C) record the delivery of terrestrial carbon to the coastal waters of Puerto Rico